Characteristics or attributes of the outer boundaries of objects, including molecules.
The quality or state of being wettable or the degree to which something can be wet. This is also the ability of any solid surface to be wetted when in contact with a liquid whose surface tension is reduced so that the liquid spreads over the surface of the solid.
Physicochemical property of fimbriated (FIMBRIAE, BACTERIAL) and non-fimbriated bacteria of attaching to cells, tissue, and nonbiological surfaces. It is a factor in bacterial colonization and pathogenicity.
The force acting on the surface of a liquid, tending to minimize the area of the surface. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)
A dark-gray, metallic element of widespread distribution but occurring in small amounts; atomic number, 22; atomic weight, 47.90; symbol, Ti; specific gravity, 4.5; used for fixation of fractures. (Dorland, 28th ed)
The adhesion of gases, liquids, or dissolved solids onto a surface. It includes adsorptive phenomena of bacteria and viruses onto surfaces as well. ABSORPTION into the substance may follow but not necessarily.
Coating with a metal or alloy by electrolysis.
Polymerized forms of styrene used as a biocompatible material, especially in dentistry. They are thermoplastic and are used as insulators, for injection molding and casting, as sheets, plates, rods, rigid forms and beads.
The thermodynamic interaction between a substance and WATER.
Synthetic or natural materials, other than DRUGS, that are used to replace or repair any body TISSUES or bodily function.
Creation of a smooth and glossy surface finish on a denture or amalgam.
A method of separation of two or more substances by repeated distribution between two immiscible liquid phases that move past each other in opposite directions. It is a form of liquid-liquid chromatography. (Stedman, 25th ed)
The testing of materials and devices, especially those used for PROSTHESES AND IMPLANTS; SUTURES; TISSUE ADHESIVES; etc., for hardness, strength, durability, safety, efficacy, and biocompatibility.
Microscopy in which the object is examined directly by an electron beam scanning the specimen point-by-point. The image is constructed by detecting the products of specimen interactions that are projected above the plane of the sample, such as backscattered electrons. Although SCANNING TRANSMISSION ELECTRON MICROSCOPY also scans the specimen point by point with the electron beam, the image is constructed by detecting the electrons, or their interaction products that are transmitted through the sample plane, so that is a form of TRANSMISSION ELECTRON MICROSCOPY.
Substances and drugs that lower the SURFACE TENSION of the mucoid layer lining the PULMONARY ALVEOLI.
Eight-carbon saturated hydrocarbon group of the methane series. Include isomers and derivatives.
Materials which have structured components with at least one dimension in the range of 1 to 100 nanometers. These include NANOCOMPOSITES; NANOPARTICLES; NANOTUBES; and NANOWIRES.
The mechanical property of material that determines its resistance to force. HARDNESS TESTS measure this property.
Relating to the size of solids.
A subclass of GLYCOSPHINGOLIPIDS containing large polar heads made up of several sugar units. One or more of their terminal sugar units are bound to a negatively charged molecule at pH 7. Members of this class include: GANGLIOSIDES, uronoglycosphingolipids, SULFOGLYCOSPHINGOLIPIDS, phosphoglycosphingolipids, and phosphonoglycosphingolipids.
Identification and measurement of ELEMENTS and their location based on the fact that X-RAYS emitted by an element excited by an electron beam have a wavelength characteristic of that element and an intensity related to its concentration. It is performed with an electron microscope fitted with an x-ray spectrometer, in scanning or transmission mode.
The lipid- and protein-containing, selectively permeable membrane that surrounds the cytoplasm in prokaryotic and eukaryotic cells.
Ionized gases, consisting of free electrons and ionized atoms or molecules which collectively behave differently than gas, solid, or liquid. Plasma gases are used in biomedical fields in surface modification; biological decontamination; dentistry (e.g., PLASMA ARC DENTAL CURING LIGHTS); and in other treatments (e.g., ARGON PLASMA COAGULATION).
A type of scanning probe microscopy in which a probe systematically rides across the surface of a sample being scanned in a raster pattern. The vertical position is recorded as a spring attached to the probe rises and falls in response to peaks and valleys on the surface. These deflections produce a topographic map of the sample.
An oxide of aluminum, occurring in nature as various minerals such as bauxite, corundum, etc. It is used as an adsorbent, desiccating agent, and catalyst, and in the manufacture of dental cements and refractories.
A species of gram-negative bacteria in the genus PSEUDOMONAS. It cannot utilize FRUCTOSE; GLUCOSE; or MALTOSE for energy.
Usually high-molecular-weight, straight-chain primary alcohols, but can also range from as few as 4 carbons, derived from natural fats and oils, including lauryl, stearyl, oleyl, and linoleyl alcohols. They are used in pharmaceuticals, cosmetics, detergents, plastics, and lube oils and in textile manufacture. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 5th ed)
An alkylating carcinogen that produces gastrointestinal and probably lung and nervous system tumors.
Nanometer-sized particles that are nanoscale in three dimensions. They include nanocrystaline materials; NANOCAPSULES; METAL NANOPARTICLES; DENDRIMERS, and QUANTUM DOTS. The uses of nanoparticles include DRUG DELIVERY SYSTEMS and cancer targeting and imaging.
Mannosides formed by the reaction of the hydroxyl group on the anomeric carbon atom of mannose with methyl alcohol. They include both alpha- and beta-methylmannosides.
A property of the surface of an object that makes it stick to another surface.
Hard, amorphous, brittle, inorganic, usually transparent, polymerous silicate of basic oxides, usually potassium or sodium. It is used in the form of hard sheets, vessels, tubing, fibers, ceramics, beads, etc.
Glycoprotein moieties on the surfaces of cell membranes that bind concanavalin A selectively; the number and location of the sites depends on the type and condition of the cell.
A clear, odorless, tasteless liquid that is essential for most animal and plant life and is an excellent solvent for many substances. The chemical formula is hydrogen oxide (H2O). (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)
An acid dye used in testing for hydrochloric acid in gastric contents. It is also used histologically to test for AMYLOIDOSIS.
Compounds formed by the joining of smaller, usually repeating, units linked by covalent bonds. These compounds often form large macromolecules (e.g., BIOPOLYMERS; PLASTICS).
Inorganic compounds that contain silicon as an integral part of the molecule.
A species of gram-positive, coccoid bacteria commensal in the respiratory tract.
The accumulation of an electric charge on a object
The process of producing a form or impression made of metal or plaster using a mold.
The visually perceived property of objects created by absorption or reflection of specific wavelengths of light.
A nonionic polyoxyethylene-polyoxypropylene block co-polymer with the general formula HO(C2H4O)a(-C3H6O)b(C2H4O)aH. It is available in different grades which vary from liquids to solids. It is used as an emulsifying agent, solubilizing agent, surfactant, and wetting agent for antibiotics. Poloxamer is also used in ointment and suppository bases and as a tablet binder or coater. (Martindale The Extra Pharmacopoeia, 31st ed)
An electrochemical process in which macromolecules or colloidal particles with a net electric charge migrate in a solution under the influence of an electric current.
The ability of a substance to be dissolved, i.e. to form a solution with another substance. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)
Silicone polymers which consist of silicon atoms substituted with methyl groups and linked by oxygen atoms. They comprise a series of biocompatible materials used as liquids, gels or solids; as film for artificial membranes, gels for implants, and liquids for drug vehicles; and as antifoaming agents.
Synthetic phospholipid used in liposomes and lipid bilayers to study biological membranes. It is also a major constituent of PULMONARY SURFACTANTS.
Polymers of ETHYLENE OXIDE and water, and their ethers. They vary in consistency from liquid to solid depending on the molecular weight indicated by a number following the name. They are used as SURFACTANTS, dispersing agents, solvents, ointment and suppository bases, vehicles, and tablet excipients. Some specific groups are NONOXYNOLS, OCTOXYNOLS, and POLOXAMERS.
Artificial substitutes for body parts, and materials inserted into tissue for functional, cosmetic, or therapeutic purposes. Prostheses can be functional, as in the case of artificial arms and legs, or cosmetic, as in the case of an artificial eye. Implants, all surgically inserted or grafted into the body, tend to be used therapeutically. IMPLANTS, EXPERIMENTAL is available for those used experimentally.
Agents that modify interfacial tension of water; usually substances that have one lipophilic and one hydrophilic group in the molecule; includes soaps, detergents, emulsifiers, dispersing and wetting agents, and several groups of antiseptics.
The physical effects involving the presence of electric charges at rest and in motion.
The generic name for the group of aliphatic hydrocarbons Cn-H2n+2. They are denoted by the suffix -ane. (Grant & Hackh's Chemical Dictionary, 5th ed)
The spectrometric analysis of fluorescent X-RAYS, i.e. X-rays emitted after bombarding matter with high energy particles such as PROTONS; ELECTRONS; or higher energy X-rays. Identification of ELEMENTS by this technique is based on the specific type of X-rays that are emitted which are characteristic of the specific elements in the material being analyzed. The characteristic X-rays are distinguished and/or quantified by either wavelength dispersive or energy dispersive methods.
Encrustations, formed from microbes (bacteria, algae, fungi, plankton, or protozoa) embedding in extracellular polymers, that adhere to surfaces such as teeth (DENTAL DEPOSITS); PROSTHESES AND IMPLANTS; and catheters. Biofilms are prevented from forming by treating surfaces with DENTIFRICES; DISINFECTANTS; ANTI-INFECTIVE AGENTS; and antifouling agents.
A nitrogen-free class of lipids present in animal and particularly plant tissues and composed of one mole of glycerol and 1 or 2 moles of phosphatidic acid. Members of this group differ from one another in the nature of the fatty acids released on hydrolysis.
The physical phenomena describing the structure and properties of atoms and molecules, and their reaction and interaction processes.
Preparation of TOOTH surfaces, and of materials bonded to teeth or DENTAL IMPLANTS, with agents and methods which roughen the surface to facilitate adhesion. Agents include phosphoric or other acids (ACID ETCHING, DENTAL) and methods include LASERS.
The clumping together of suspended material resulting from the action of AGGLUTININS.
A spectroscopic technique in which a range of wavelengths is presented simultaneously with an interferometer and the spectrum is mathematically derived from the pattern thus obtained.
Biocompatible materials usually used in dental and bone implants that enhance biologic fixation, thereby increasing the bond strength between the coated material and bone, and minimize possible biological effects that may result from the implant itself.
Artificially produced membranes, such as semipermeable membranes used in artificial kidney dialysis (RENAL DIALYSIS), monomolecular and bimolecular membranes used as models to simulate biological CELL MEMBRANES. These membranes are also used in the process of GUIDED TISSUE REGENERATION.
Substances made up of an aggregation of small particles, as that obtained by grinding or trituration of a solid drug. In pharmacy it is a form in which substances are administered. (From Dorland, 28th ed)
The study of CHEMICAL PHENOMENA and processes in terms of the underlying PHYSICAL PHENOMENA and processes.
The sensory discrimination of a pattern shape or outline.
A biocompatible polymer used as a surgical suture material.
Adherence of cells to surfaces or to other cells.
Usually inert substances added to a prescription in order to provide suitable consistency to the dosage form. These include binders, matrix, base or diluent in pills, tablets, creams, salves, etc.
Materials used in the production of dental bases, restorations, impressions, prostheses, etc.
The outermost layer of a cell in most PLANTS; BACTERIA; FUNGI; and ALGAE. The cell wall is usually a rigid structure that lies external to the CELL MEMBRANE, and provides a protective barrier against physical or chemical agents.
Microscopy using an electron beam, instead of light, to visualize the sample, thereby allowing much greater magnification. The interactions of ELECTRONS with specimens are used to provide information about the fine structure of that specimen. In TRANSMISSION ELECTRON MICROSCOPY the reactions of the electrons that are transmitted through the specimen are imaged. In SCANNING ELECTRON MICROSCOPY an electron beam falls at a non-normal angle on the specimen and the image is derived from the reactions occurring above the plane of the specimen.
Transparent, tasteless crystals found in nature as agate, amethyst, chalcedony, cristobalite, flint, sand, QUARTZ, and tridymite. The compound is insoluble in water or acids except hydrofluoric acid.
Materials fabricated by BIOMIMETICS techniques, i.e., based on natural processes found in biological systems.
A group of glucose polymers made by certain bacteria. Dextrans are used therapeutically as plasma volume expanders and anticoagulants. They are also commonly used in biological experimentation and in industry for a wide variety of purposes.
The engulfing and degradation of microorganisms; other cells that are dead, dying, or pathogenic; and foreign particles by phagocytic cells (PHAGOCYTES).
The normality of a solution with respect to HYDROGEN ions; H+. It is related to acidity measurements in most cases by pH = log 1/2[1/(H+)], where (H+) is the hydrogen ion concentration in gram equivalents per liter of solution. (McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)
The property of objects that determines the direction of heat flow when they are placed in direct thermal contact. The temperature is the energy of microscopic motions (vibrational and translational) of the particles of atoms.
Any liquid or solid preparation made specifically for the growth, storage, or transport of microorganisms or other types of cells. The variety of media that exist allow for the culturing of specific microorganisms and cell types, such as differential media, selective media, test media, and defined media. Solid media consist of liquid media that have been solidified with an agent such as AGAR or GELATIN.
Small uniformly-sized spherical particles, of micrometer dimensions, frequently labeled with radioisotopes or various reagents acting as tags or markers.
The development and use of techniques to study physical phenomena and construct structures in the nanoscale size range or smaller.
Thin, hairlike appendages, 1 to 20 microns in length and often occurring in large numbers, present on the cells of gram-negative bacteria, particularly Enterobacteriaceae and Neisseria. Unlike flagella, they do not possess motility, but being protein (pilin) in nature, they possess antigenic and hemagglutinating properties. They are of medical importance because some fimbriae mediate the attachment of bacteria to cells via adhesins (ADHESINS, BACTERIAL). Bacterial fimbriae refer to common pili, to be distinguished from the preferred use of "pili", which is confined to sex pili (PILI, SEX).
Nanoparticles produced from metals whose uses include biosensors, optics, and catalysts. In biomedical applications the particles frequently involve the noble metals, especially gold and silver.
Proteins that share the common characteristic of binding to carbohydrates. Some ANTIBODIES and carbohydrate-metabolizing proteins (ENZYMES) also bind to carbohydrates, however they are not considered lectins. PLANT LECTINS are carbohydrate-binding proteins that have been primarily identified by their hemagglutinating activity (HEMAGGLUTININS). However, a variety of lectins occur in animal species where they serve diverse array of functions through specific carbohydrate recognition.
The study of chemical changes resulting from electrical action and electrical activity resulting from chemical changes.
A yellow metallic element with the atomic symbol Au, atomic number 79, and atomic weight 197. It is used in jewelry, goldplating of other metals, as currency, and in dental restoration. Many of its clinical applications, such as ANTIRHEUMATIC AGENTS, are in the form of its salts.
A MANNOSE/GLUCOSE binding lectin isolated from the jack bean (Canavalia ensiformis). It is a potent mitogen used to stimulate cell proliferation in lymphocytes, primarily T-lymphocyte, cultures.
Antigens on surfaces of cells, including infectious or foreign cells or viruses. They are usually protein-containing groups on cell membranes or walls and may be isolated.
Derivatives of phosphatidic acids in which the phosphoric acid is bound in ester linkage to a choline moiety. Complete hydrolysis yields 1 mole of glycerol, phosphoric acid and choline and 2 moles of fatty acids.
The scattering of x-rays by matter, especially crystals, with accompanying variation in intensity due to interference effects. Analysis of the crystal structure of materials is performed by passing x-rays through them and registering the diffraction image of the rays (CRYSTALLOGRAPHY, X-RAY). (From McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)
A species of gram-negative, facultatively anaerobic, rod-shaped bacteria (GRAM-NEGATIVE FACULTATIVELY ANAEROBIC RODS) commonly found in the lower part of the intestine of warm-blooded animals. It is usually nonpathogenic, but some strains are known to produce DIARRHEA and pyogenic infections. Pathogenic strains (virotypes) are classified by their specific pathogenic mechanisms such as toxins (ENTEROTOXIGENIC ESCHERICHIA COLI), etc.
Proteins found in any species of bacterium.
Bone-forming cells which secrete an EXTRACELLULAR MATRIX. HYDROXYAPATITE crystals are then deposited into the matrix to form bone.
Artificial, single or multilaminar vesicles (made from lecithins or other lipids) that are used for the delivery of a variety of biological molecules or molecular complexes to cells, for example, drug delivery and gene transfer. They are also used to study membranes and membrane proteins.
A polysaccharide-producing species of STREPTOCOCCUS isolated from human dental plaque.
Reproductive bodies produced by fungi.
Models used experimentally or theoretically to study molecular shape, electronic properties, or interactions; includes analogous molecules, computer-generated graphics, and mechanical structures.
The formation of crystalline substances from solutions or melts. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)
Tests that are dependent on the clumping of cells, microorganisms, or particles when mixed with specific antiserum. (From Stedman, 26th ed)
A nonmetallic element with atomic symbol C, atomic number 6, and atomic weight [12.0096; 12.0116]. It may occur as several different allotropes including DIAMOND; CHARCOAL; and GRAPHITE; and as SOOT from incompletely burned fuel.
The quality of surface form or outline of CELLS.
Bacterial polysaccharides that are rich in phosphodiester linkages. They are the major components of the cell walls and membranes of many bacteria.
Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.
The order of amino acids as they occur in a polypeptide chain. This is referred to as the primary structure of proteins. It is of fundamental importance in determining PROTEIN CONFORMATION.
Polysaccharides found in bacteria and in capsules thereof.
Differential thermal analysis in which the sample compartment of the apparatus is a differential calorimeter, allowing an exact measure of the heat of transition independent of the specific heat, thermal conductivity, and other variables of the sample.
A type of stress exerted uniformly in all directions. Its measure is the force exerted per unit area. (McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)
The resistance that a gaseous or liquid system offers to flow when it is subjected to shear stress. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)
Systems for the delivery of drugs to target sites of pharmacological actions. Technologies employed include those concerning drug preparation, route of administration, site targeting, metabolism, and toxicity.
The species Oryctolagus cuniculus, in the family Leporidae, order LAGOMORPHA. Rabbits are born in burrows, furless, and with eyes and ears closed. In contrast with HARES, rabbits have 22 chromosome pairs.
The degree of pathogenicity within a group or species of microorganisms or viruses as indicated by case fatality rates and/or the ability of the organism to invade the tissues of the host. The pathogenic capacity of an organism is determined by its VIRULENCE FACTORS.
Lipids containing one or more phosphate groups, particularly those derived from either glycerol (phosphoglycerides see GLYCEROPHOSPHOLIPIDS) or sphingosine (SPHINGOLIPIDS). They are polar lipids that are of great importance for the structure and function of cell membranes and are the most abundant of membrane lipids, although not stored in large amounts in the system.
The phenomenon by which dissociated cells intermixed in vitro tend to group themselves with cells of their own type.
A normal intermediate in the fermentation (oxidation, metabolism) of sugar. The concentrated form is used internally to prevent gastrointestinal fermentation. (From Stedman, 26th ed)
The characteristic 3-dimensional shape of a protein, including the secondary, supersecondary (motifs), tertiary (domains) and quaternary structure of the peptide chain. PROTEIN STRUCTURE, QUATERNARY describes the conformation assumed by multimeric proteins (aggregates of more than one polypeptide chain).
The homogeneous mixtures formed by the mixing of a solid, liquid, or gaseous substance (solute) with a liquid (the solvent), from which the dissolved substances can be recovered by physical processes. (From Grant & Hackh's Chemical Dictionary, 5th ed)
Liquids that dissolve other substances (solutes), generally solids, without any change in chemical composition, as, water containing sugar. (Grant & Hackh's Chemical Dictionary, 5th ed)
A genus of gram-positive, coccoid bacteria whose organisms occur in pairs or chains. No endospores are produced. Many species exist as commensals or parasites on man or animals with some being highly pathogenic. A few species are saprophytes and occur in the natural environment.
Established cell cultures that have the potential to propagate indefinitely.
Any detectable and heritable change in the genetic material that causes a change in the GENOTYPE and which is transmitted to daughter cells and to succeeding generations.
Domesticated bovine animals of the genus Bos, usually kept on a farm or ranch and used for the production of meat or dairy products or for heavy labor.
Proteins isolated from the outer membrane of Gram-negative bacteria.
Cells propagated in vitro in special media conducive to their growth. Cultured cells are used to study developmental, morphologic, metabolic, physiologic, and genetic processes, among others.
The process in which substances, either endogenous or exogenous, bind to proteins, peptides, enzymes, protein precursors, or allied compounds. Specific protein-binding measures are often used as assays in diagnostic assessments.
Proteins which are found in membranes including cellular and intracellular membranes. They consist of two types, peripheral and integral proteins. They include most membrane-associated enzymes, antigenic proteins, transport proteins, and drug, hormone, and lectin receptors.
The parts of a macromolecule that directly participate in its specific combination with another molecule.
The characteristic three-dimensional shape of a molecule.
Lipid-containing polysaccharides which are endotoxins and important group-specific antigens. They are often derived from the cell wall of gram-negative bacteria and induce immunoglobulin secretion. The lipopolysaccharide molecule consists of three parts: LIPID A, core polysaccharide, and O-specific chains (O ANTIGENS). When derived from Escherichia coli, lipopolysaccharides serve as polyclonal B-cell mitogens commonly used in laboratory immunology. (From Dorland, 28th ed)
The rate dynamics in chemical or physical systems.
A rigorously mathematical analysis of energy relationships (heat, work, temperature, and equilibrium). It describes systems whose states are determined by thermal parameters, such as temperature, in addition to mechanical and electromagnetic parameters. (From Hawley's Condensed Chemical Dictionary, 12th ed)
Investigative technique commonly used during ELECTROENCEPHALOGRAPHY in which a series of bright light flashes or visual patterns are used to elicit brain activity.
Generating tissue in vitro for clinical applications, such as replacing wounded tissues or impaired organs. The use of TISSUE SCAFFOLDING enables the generation of complex multi-layered tissues and tissue structures.
Measurement of the intensity and quality of fluorescence.
The level of protein structure in which regular hydrogen-bond interactions within contiguous stretches of polypeptide chain give rise to alpha helices, beta strands (which align to form beta sheets) or other types of coils. This is the first folding level of protein conformation.
Compounds and molecular complexes that consist of very large numbers of atoms and are generally over 500 kDa in size. In biological systems macromolecular substances usually can be visualized using ELECTRON MICROSCOPY and are distinguished from ORGANELLES by the lack of a membrane structure.
Microscopy of specimens stained with fluorescent dye (usually fluorescein isothiocyanate) or of naturally fluorescent materials, which emit light when exposed to ultraviolet or blue light. Immunofluorescence microscopy utilizes antibodies that are labeled with fluorescent dye.
Agents that emit light after excitation by light. The wave length of the emitted light is usually longer than that of the incident light. Fluorochromes are substances that cause fluorescence in other substances, i.e., dyes used to mark or label other compounds with fluorescent tags.
Spectroscopic method of measuring the magnetic moment of elementary particles such as atomic nuclei, protons or electrons. It is employed in clinical applications such as NMR Tomography (MAGNETIC RESONANCE IMAGING).
Members of the class of compounds composed of AMINO ACIDS joined together by peptide bonds between adjacent amino acids into linear, branched or cyclical structures. OLIGOPEPTIDES are composed of approximately 2-12 amino acids. Polypeptides are composed of approximately 13 or more amino acids. PROTEINS are linear polypeptides that are normally synthesized on RIBOSOMES.
Red blood cells. Mature erythrocytes are non-nucleated, biconcave disks containing HEMOGLOBIN whose function is to transport OXYGEN.
Presence of warmth or heat or a temperature notably higher than an accustomed norm.
The location of the atoms, groups or ions relative to one another in a molecule, as well as the number, type and location of covalent bonds.
Linear POLYPEPTIDES that are synthesized on RIBOSOMES and may be further modified, crosslinked, cleaved, or assembled into complex proteins with several subunits. The specific sequence of AMINO ACIDS determines the shape the polypeptide will take, during PROTEIN FOLDING, and the function of the protein.
Electrophoresis in which a polyacrylamide gel is used as the diffusion medium.
Theoretical representations that simulate the behavior or activity of chemical processes or phenomena; includes the use of mathematical equations, computers, and other electronic equipment.
A generic term for fats and lipoids, the alcohol-ether-soluble constituents of protoplasm, which are insoluble in water. They comprise the fats, fatty oils, essential oils, waxes, phospholipids, glycolipids, sulfolipids, aminolipids, chromolipids (lipochromes), and fatty acids. (Grant & Hackh's Chemical Dictionary, 5th ed)
Extrachromosomal, usually CIRCULAR DNA molecules that are self-replicating and transferable from one organism to another. They are found in a variety of bacterial, archaeal, fungal, algal, and plant species. They are used in GENETIC ENGINEERING as CLONING VECTORS.

Neuronal activity in somatosensory cortex of monkeys using a precision grip. II. Responses To object texture and weights. (1/8297)

Three monkeys were trained to lift and hold a test object within a 12- to 25-mm position window for 1 s. The activity of single neurons was recorded during performance of the task in which both the weight and surface texture of the object were systematically varied. Whenever possible, each cell was tested with three weights (15, 65, and 115 g) and three textures (smooth metal, fine 200 grit sandpaper, and rough 60 grit sandpaper). Of 386 cells recorded in 3 monkeys, 45 cells had cutaneous receptive fields on the index or thumb or part of the thenar eminence and were held long enough to be tested in all 9 combinations of texture and weight. Recordings were made for the entire anterior-posterior extent of the thumb and index finger areas in somatosensory cortex including area 7b. However, the statistical analysis required a selection of only those cells for which nine complete recording conditions were available limiting the sample to cells in areas 2, 5, and 7b. Significant differences in the grip force accompanied 98% of the changes in texture and 78% of the changes in weight. Increasing the object weight also increased the force tangential to the skin surface as measured by the load or lifting force. The peak discharge during lifting was judged to be the most sensitive index of cell activity and was analyzed with a two-way analysis of variance (ANOVA). In addition, peak cell discharge was normalized to allow comparisons among different combinations of texture and weight as well as comparisons among different neurons. Overall, the peak firing frequency of 87% of the cells was significantly modulated by changes in object texture, but changes in object weight affected the peak activity of only 58% of the cells. Almost all (17/18, 94%) of the static cells were influenced by the object texture, and 81% of the dynamic cells that were active only briefly at grip and lift onset were modulated by texture. For some cells, surface texture had a significant effect on neuronal discharge that was independent of the object weight. In contrast, weight-related responses were never simple main effects of the weight alone and appeared instead as significant interactions between texture and weight. Four neurons either increased or decreased activity in a graded fashion with surface structure (roughness) regardless of the object weight (P < 0.05). Ten other neurons showed increases or decreases in response to one or two textures, which might represent either a graded response or a tuning preference for a specific texture. The firing frequency of the majority (31/45) of neurons reflected an interaction of both texture and weight. The cells with texture-related but weight-independent activities were thought to encode surface characteristics that are largely independent of the grip and lifting forces used to manipulate the object. Such constancies could be used to construct internal representations or mental models for planning and controlling object manipulation.  (+info)

The forward rate of binding of surface-tethered reactants: effect of relative motion between two surfaces. (2/8297)

The reaction of molecules confined to two dimensions is of interest in cell adhesion, specifically for the reaction between cell surface receptors and substrate-bound ligand. We have developed a model to describe the overall rate of reaction of species that are bound to surfaces under relative motion, such that the Peclet number is order one or greater. The encounter rate between reactive species is calculated from solution of the two-dimensional convection-diffusion equation. The probability that each encounter will lead to binding depends on the intrinsic rate of reaction and the encounter duration. The encounter duration is obtained from the theory of first passage times. We find that the binding rate increases with relative velocity between the two surfaces, then reaches a plateau. This plateau indicates that the increase in the encounter rate is counterbalanced by the decrease in the encounter duration as the relative velocity increases. The binding rate is fully described by two dimensionless parameters, the Peclet number and the Damkohler number. We use this model to explain data from the cell adhesion literature by incorporating these rate laws into "adhesive dynamics" simulations to model the binding of a cell to a surface under flow. Leukocytes are known to display a "shear threshold effect" when binding selectin-coated surfaces under shear flow, defined as an increase in bind rate with shear; this effect, as calculated here, is due to an increase in collisions between receptor and ligand with increasing shear. The model can be used to explain other published data on the effect of wall shear rate on the binding of cells to surfaces, specifically the mild decrease in binding within a fixed area with increasing shear rate.  (+info)

Kinetic and thermodynamic aspects of lipid translocation in biological membranes. (3/8297)

A theoretical analysis of the lipid translocation in cellular bilayer membranes is presented. We focus on an integrative model of active and passive transport processes determining the asymmetrical distribution of the major lipid components between the monolayers. The active translocation of the aminophospholipids phosphatidylserine and phosphatidylethanolamine is mathematically described by kinetic equations resulting from a realistic ATP-dependent transport mechanism. Concerning the passive transport of the aminophospholipids as well as of phosphatidylcholine, sphingomyelin, and cholesterol, two different approaches are used. The first treatment makes use of thermodynamic flux-force relationships. Relevant forces are transversal concentration differences of the lipids as well as differences in the mechanical states of the monolayers due to lateral compressions. Both forces, originating primarily from the operation of an aminophospholipid translocase, are expressed as functions of the lipid compositions of the two monolayers. In the case of mechanical forces, lipid-specific parameters such as different molecular surface areas and compression force constants are taken into account. Using invariance principles, it is shown how the phenomenological coefficients depend on the total lipid amounts. In a second approach, passive transport is analyzed in terms of kinetic mechanisms of carrier-mediated translocation, where mechanical effects are incorporated into the translocation rate constants. The thermodynamic as well as the kinetic approach are applied to simulate the time-dependent redistribution of the lipid components in human red blood cells. In the thermodynamic model the steady-state asymmetrical lipid distribution of erythrocyte membranes is simulated well under certain parameter restrictions: 1) the time scales of uncoupled passive transbilayer movement must be different among the lipid species; 2) positive cross-couplings of the passive lipid fluxes are needed, which, however, may be chosen lipid-unspecifically. A comparison of the thermodynamic and the kinetic approaches reveals that antiport mechanisms for passive lipid movements may be excluded. Simulations with kinetic symport mechanisms are in qualitative agreement with experimental data but show discrepancies in the asymmetrical distribution for sphingomyelin.  (+info)

Surface-induced polymerization of actin. (4/8297)

Living cells contain a very large amount of membrane surface area, which potentially influences the direction, the kinetics, and the localization of biochemical reactions. This paper quantitatively evaluates the possibility that a lipid monolayer can adsorb actin from a nonpolymerizing solution, induce its polymerization, and form a 2D network of individual actin filaments, in conditions that forbid bulk polymerization. G- and F-actin solutions were studied beneath saturated Langmuir monolayers containing phosphatidylcholine (PC, neutral) and stearylamine (SA, a positively charged surfactant) at PC:SA = 3:1 molar ratio. Ellipsometry, tensiometry, shear elastic measurements, electron microscopy, and dark-field light microscopy were used to characterize the adsorption kinetics and the interfacial polymerization of actin. In all cases studied, actin follows a monoexponential reaction-limited adsorption with similar time constants (approximately 10(3) s). At a longer time scale the shear elasticity of the monomeric actin adsorbate increases only in the presence of lipids, to a 2D shear elastic modulus of mu approximately 30 mN/m, indicating the formation of a structure coupled to the monolayer. Electron microscopy shows the formation of a 2D network of actin filaments at the PC:SA surface, and several arguments strongly suggest that this network is indeed causing the observed elasticity. Adsorption of F-actin to PC:SA leads more quickly to a slightly more rigid interface with a modulus of mu approximately 50 mN/m.  (+info)

Adhesion energy of receptor-mediated interaction measured by elastic deformation. (5/8297)

We investigated the role of receptor binding affinity in surface adhesion. A sensitive technique was developed to measure the surface energy of receptor-mediated adhesion. The experimental system involved a functionalized elastic agarose bead resting on a functionalized glass coverslip. Attractive intersurface forces pulled the two surfaces together, deforming the bead to produce an enlarged contact area. The Johnson-Kendall-Roberts (JKR) model was used to relate the surface energy of the interaction to the elasticity of the bead and the area of contact. The surface energies for different combinations of modified surfaces in solution were obtained from reflection interference contrast microscopy (RICM) measurements of the contact area formed by the bead and the coverslip. Studies with surfaces functionalized with ligand-receptor pairs showed that the relationship between surface energy and the association constant of the ligand binding has two regimes. At low binding affinity, surface energy increased linearly with the association constant, while surface energy increased logarithmically with the association constant in the high affinity regime.  (+info)

Bacteriophage inactivation at the air-water-solid interface in dynamic batch systems. (6/8297)

Bacteriophages have been widely used as surrogates for human enteric viruses in many studies on virus transport and fate. In this investigation, the fates of three bacteriophages, MS2, R17, and phiX174, were studied in a series of dynamic batch experiments. Both MS2 and R17 readily underwent inactivation in batch experiments where solutions of each phage were percolated through tubes packed with varying ratios of glass and Teflon beads. MS2 and R17 inactivation was the result of exposure to destructive forces at the dynamic air-water-solid interface. phiX174, however, did not undergo inactivation in similar studies, suggesting that this phage does not accumulate at air-water interfaces or is not affected by interfacial forces in the same manner. Other batch experiments showed that MS2 and R17 were increasingly inactivated during mixing in polypropylene tubes as the ionic strength of the solution was raised (phiX174 was not affected). By the addition of Tween 80 to suspensions of MS2 and R17, phage inactivation was prevented. Our data suggest that viral inactivation in simple dynamic batch experiments is dependent upon (i) the presence of a dynamic air-water-solid interface (where the solid is a hydrophobic surface), (ii) the ionic strength of the solution, (iii) the concentration of surface active compounds in the solution, and (iv) the type of virus used.  (+info)

Native display of complete foreign protein domains on the surface of hepatitis B virus capsids. (7/8297)

The nucleocapsid of hepatitis B virus (HBV), or HBcAg, is a highly symmetric structure formed by multiple dimers of a single core protein that contains potent T helper epitopes in its 183-aa sequence. Both factors make HBcAg an unusually strong immunogen and an attractive candidate as a carrier for foreign epitopes. The immunodominant c/e1 epitope on the capsid has been suggested as a superior location to convey high immunogenicity to a heterologous sequence. Because of its central position, however, any c/e1 insert disrupts the core protein's primary sequence; hence, only peptides, or rather small protein fragments seemed to be compatible with particle formation. According to recent structural data, the epitope is located at the tips of prominent surface spikes formed by the very stable dimer interfaces. We therefore reasoned that much larger inserts might be tolerated, provided the individual parts of a corresponding fusion protein could fold independently. Using the green fluorescent protein (GFP) as a model insert, we show that the chimeric protein efficiently forms fluorescent particles; hence, all of its structurally important parts must be properly folded. We also demonstrate that the GFP domains are surface-exposed and that the chimeric particles elicit a potent humoral response against native GFP. Hence, proteins of at least up to 238 aa can be natively displayed on the surface of HBV core particles. Such chimeras may not only be useful as vaccines but may also open the way for high resolution structural analyses of nonassembling proteins by electron microscopy.  (+info)

Affinity modulation of small-molecule ligands by borrowing endogenous protein surfaces. (8/8297)

A general strategy is described for improving the binding properties of small-molecule ligands to protein targets. A bifunctional molecule is created by chemically linking a ligand of interest to another small molecule that binds tightly to a second protein. When the ligand of interest is presented to the target protein by the second protein, additional protein-protein interactions outside of the ligand-binding sites serve either to increase or decrease the affinity of the binding event. We have applied this approach to an intractable target, the SH2 domain, and demonstrate a 3-fold enhancement over the natural peptide. This approach provides a way to modulate the potency and specificity of biologically active compounds.  (+info)

Surface properties in the context of medical science refer to the characteristics and features of the outermost layer or surface of a biological material or structure, such as cells, tissues, organs, or medical devices. These properties can include physical attributes like roughness, smoothness, hydrophobicity or hydrophilicity, and electrical conductivity, as well as chemical properties like charge, reactivity, and composition.

In the field of biomaterials science, understanding surface properties is crucial for designing medical implants, devices, and drug delivery systems that can interact safely and effectively with biological tissues and fluids. Surface modifications, such as coatings or chemical treatments, can be used to alter surface properties and enhance biocompatibility, improve lubricity, reduce fouling, or promote specific cellular responses like adhesion, proliferation, or differentiation.

Similarly, in the field of cell biology, understanding surface properties is essential for studying cell-cell interactions, cell signaling, and cell behavior. Cells can sense and respond to changes in their environment, including variations in surface properties, which can influence cell shape, motility, and function. Therefore, characterizing and manipulating surface properties can provide valuable insights into the mechanisms of cellular processes and offer new strategies for developing therapies and treatments for various diseases.

"Wettability" is not a term that has a specific medical definition. It is a term that is more commonly used in the fields of chemistry, physics, and materials science to describe how well a liquid spreads on a solid surface. In other words, it refers to the ability of a liquid to maintain contact with a solid surface, which can have implications for various medical applications such as the design of medical devices or the study of biological surfaces. However, it is not a term that would typically be used in a clinical medical context.

Bacterial adhesion is the initial and crucial step in the process of bacterial colonization, where bacteria attach themselves to a surface or tissue. This process involves specific interactions between bacterial adhesins (proteins, fimbriae, or pili) and host receptors (glycoproteins, glycolipids, or extracellular matrix components). The attachment can be either reversible or irreversible, depending on the strength of interaction. Bacterial adhesion is a significant factor in initiating biofilm formation, which can lead to various infectious diseases and medical device-associated infections.

Surface tension is not a term that has a specific medical definition. However, it is a physical chemistry concept that relates to the cohesive force between liquid molecules, causing the surface of the liquid to contract and have a higher intermolecular force than its bulk.

In a broader sense, surface tension can have implications in certain medical or biological contexts, such as the movement of liquids in the lungs or the stability of lipid bilayers in cell membranes. But it is not a term that is typically used to describe medical conditions or treatments.

Titanium is not a medical term, but rather a chemical element (symbol Ti, atomic number 22) that is widely used in the medical field due to its unique properties. Medically, it is often referred to as a biocompatible material used in various medical applications such as:

1. Orthopedic implants: Titanium and its alloys are used for making joint replacements (hips, knees, shoulders), bone plates, screws, and rods due to their high strength-to-weight ratio, excellent corrosion resistance, and biocompatibility.
2. Dental implants: Titanium is also commonly used in dental applications like implants, crowns, and bridges because of its ability to osseointegrate, or fuse directly with bone tissue, providing a stable foundation for replacement teeth.
3. Cardiovascular devices: Titanium alloys are used in the construction of heart valves, pacemakers, and other cardiovascular implants due to their non-magnetic properties, which prevent interference with magnetic resonance imaging (MRI) scans.
4. Medical instruments: Due to its resistance to corrosion and high strength, titanium is used in the manufacturing of various medical instruments such as surgical tools, needles, and catheters.

In summary, Titanium is a chemical element with unique properties that make it an ideal material for various medical applications, including orthopedic and dental implants, cardiovascular devices, and medical instruments.

Adsorption is a process in which atoms, ions, or molecules from a gas, liquid, or dissolved solid accumulate on the surface of a material. This occurs because the particles in the adsorbate (the substance being adsorbed) have forces that attract them to the surface of the adsorbent (the material that the adsorbate is adhering to).

In medical terms, adsorption can refer to the use of materials with adsorptive properties to remove harmful substances from the body. For example, activated charcoal is sometimes used in the treatment of poisoning because it can adsorb a variety of toxic substances and prevent them from being absorbed into the bloodstream.

It's important to note that adsorption is different from absorption, which refers to the process by which a substance is taken up and distributed throughout a material or tissue.

Electroplating is not a medical term, but rather a process used in the industrial field. It refers to the process of coating an electrically conductive object with a thin layer of metal through the use of an electrical current. This process involves immersing the object in a solution containing dissolved ions of the metal to be deposited, and then passing an electric current through the solution. The object serves as the cathode, and the metal ions are reduced at its surface, forming a thin layer of pure metal.

While electroplating is not directly related to medicine, it does have some medical applications. For example, medical devices such as pacemakers or implantable defibrillators may be coated with gold or other metals through electroplating to improve their biocompatibility and reduce the risk of corrosion or rejection by the body. Similarly, dental restorations may be electroplated with precious metals to enhance their strength and durability.

I'm sorry for any confusion, but "Polystyrenes" is not a medical term. Polystyrene is a type of synthetic aromatic hydrocarbon polymer that is used in a variety of commercial and industrial products, such as packaging materials, insulation, and disposable cutlery. It's important to note that some polystyrene products may contain potentially harmful chemicals, such as styrene, which can leach out into food or drink, posing potential health risks. However, the medical community primarily deals with the health effects of exposure to these chemicals rather than defining the material itself.

Hydrophobic interactions: These are the interactions that occur between non-polar molecules or groups of atoms in an aqueous environment, leading to their association or aggregation. The term "hydrophobic" means "water-fearing" and describes the tendency of non-polar substances to repel water. When non-polar molecules or groups are placed in water, they tend to clump together to minimize contact with the polar water molecules. These interactions are primarily driven by the entropy increase of the system as a whole, rather than energy minimization. Hydrophobic interactions play crucial roles in various biological processes, such as protein folding, membrane formation, and molecular self-assembly.

Hydrophilic interactions: These are the interactions that occur between polar molecules or groups of atoms and water molecules. The term "hydrophilic" means "water-loving" and describes the attraction of polar substances to water. When polar molecules or groups are placed in water, they can form hydrogen bonds with the surrounding water molecules, which helps solvate them. Hydrophilic interactions contribute to the stability and functionality of various biological systems, such as protein structure, ion transport across membranes, and enzyme catalysis.

Biocompatible materials are non-toxic and non-reacting substances that can be used in medical devices, tissue engineering, and drug delivery systems without causing harm or adverse reactions to living tissues or organs. These materials are designed to mimic the properties of natural tissues and are able to integrate with biological systems without being rejected by the body's immune system.

Biocompatible materials can be made from a variety of substances, including metals, ceramics, polymers, and composites. The specific properties of these materials, such as their mechanical strength, flexibility, and biodegradability, are carefully selected to meet the requirements of their intended medical application.

Examples of biocompatible materials include titanium used in dental implants and joint replacements, polyethylene used in artificial hips, and hydrogels used in contact lenses and drug delivery systems. The use of biocompatible materials has revolutionized modern medicine by enabling the development of advanced medical technologies that can improve patient outcomes and quality of life.

Dental polishing is a procedure in dentistry that is performed to smooth and clean the surfaces of teeth after professional dental cleaning (prophylaxis), restoration, or other dental treatments. It is usually done using a slow-speed handpiece with a soft, rubber cup attached to it, which holds a polishing paste or a slurry of pumice and water. The polishing paste may contain an abrasive agent, fluoride, or a flavoring agent. The dental professional moves the handpiece in a circular motion over the tooth surface to remove stains, plaque, and minor surface roughness, leaving the teeth smooth and shiny. Dental polishing helps to prevent the buildup of plaque and tartar, reduce the risk of decay and gum disease, and improve the overall oral hygiene and aesthetics of the teeth.

Countercurrent distribution is a laboratory technique used in the separation and purification of chemical compounds, including drugs and natural products. It is based on the principle of countercurrent flow, where two immiscible liquids (such as an organic solvent and water) are passed through a series of connected tubes in opposite directions.

In the context of biochemistry and pharmacology, countercurrent distribution is often used to purify and analyze compounds that are present in complex biological mixtures, such as blood or plant extracts. The mixture is first loaded onto the top of the column, and then a series of solvent washes and extractions are performed to separate the components based on their partition coefficients between the two liquids.

The technique allows for the separation of compounds with similar chemical properties but different partition coefficients, making it a valuable tool in the analysis of complex mixtures. The distribution of each component is plotted as a function of the tube number, resulting in a characteristic elution profile that can be used to identify and quantify the compound of interest.

In summary, countercurrent distribution is a laboratory technique for separating and purifying chemical compounds based on their partition coefficients between two immiscible liquids passed through connected tubes in opposite directions.

I'm happy to help! However, I must clarify that "materials testing" is not a medical term per se. It is a term used in various fields, including engineering and materials science, to describe the process of subjecting materials to different tests to evaluate their properties and performance under various conditions.

In the context of medical devices or implants, materials testing may refer to the evaluation of the physical and mechanical properties of materials used in their construction. These tests can include assessments of strength, durability, biocompatibility, and other factors that are critical to ensuring the safety and efficacy of medical devices.

Medical device manufacturers must comply with regulatory standards for materials testing to ensure that their products meet specific requirements for performance, safety, and quality. These standards may vary depending on the type of device, its intended use, and the country or region in which it will be marketed and sold.

Scanning electron microscopy (SEM) is a type of electron microscopy that uses a focused beam of electrons to scan the surface of a sample and produce a high-resolution image. In SEM, a beam of electrons is scanned across the surface of a specimen, and secondary electrons are emitted from the sample due to interactions between the electrons and the atoms in the sample. These secondary electrons are then detected by a detector and used to create an image of the sample's surface topography. SEM can provide detailed images of the surface of a wide range of materials, including metals, polymers, ceramics, and biological samples. It is commonly used in materials science, biology, and electronics for the examination and analysis of surfaces at the micro- and nanoscale.

Pulmonary surfactants are a complex mixture of lipids and proteins that are produced by the alveolar type II cells in the lungs. They play a crucial role in reducing the surface tension at the air-liquid interface within the alveoli, which helps to prevent collapse of the lungs during expiration. Surfactants also have important immunological functions, such as inhibiting the growth of certain bacteria and modulating the immune response. Deficiency or dysfunction of pulmonary surfactants can lead to respiratory distress syndrome (RDS) in premature infants and other lung diseases.

I'm sorry for any confusion, but "octanes" is not a medical term. It is a term used in chemistry and physics, particularly in reference to fuel. Octane is a hydrocarbon molecule found in gasoline, and it is used as a measure of the fuel's ability to resist engine knocking or pinging during combustion.

The octane rating of gasoline typically ranges from 87 (regular) to 91-93 (premium). Higher-octane fuels are often recommended for high-performance vehicles that have higher compression ratios in their engines. If you have any questions related to medical terminology, I'd be happy to help!

Nanostructures, in the context of medical and biomedical research, refer to materials or devices with structural features that have at least one dimension ranging between 1-100 nanometers (nm). At this size scale, the properties of these structures can differ significantly from bulk materials, exhibiting unique phenomena that are often influenced by quantum effects.

Nanostructures have attracted considerable interest in biomedicine due to their potential applications in various areas such as drug delivery, diagnostics, regenerative medicine, and tissue engineering. They can be fabricated from a wide range of materials including metals, polymers, ceramics, and carbon-based materials.

Some examples of nanostructures used in biomedicine include:

1. Nanoparticles: These are tiny particles with at least one dimension in the nanoscale range. They can be made from various materials like metals, polymers, or lipids and have applications in drug delivery, imaging, and diagnostics.
2. Quantum dots: These are semiconductor nanocrystals that exhibit unique optical properties due to quantum confinement effects. They are used as fluorescent labels for bioimaging and biosensing applications.
3. Carbon nanotubes: These are hollow, cylindrical structures made of carbon atoms arranged in a hexagonal lattice. They have exceptional mechanical strength, electrical conductivity, and thermal stability, making them suitable for various biomedical applications such as drug delivery, tissue engineering, and biosensors.
4. Nanofibers: These are elongated nanostructures with high aspect ratios (length much greater than width). They can be fabricated from various materials like polymers, ceramics, or composites and have applications in tissue engineering, wound healing, and drug delivery.
5. Dendrimers: These are highly branched, nanoscale polymers with a well-defined structure and narrow size distribution. They can be used as drug carriers, gene delivery vehicles, and diagnostic agents.
6. Nanoshells: These are hollow, spherical nanoparticles consisting of a dielectric core covered by a thin metallic shell. They exhibit unique optical properties that make them suitable for applications such as photothermal therapy, biosensing, and imaging.

In the context of medical terminology, "hardness" is not a term that has a specific or standardized definition. It may be used in various ways to describe the firmness or consistency of a tissue, such as the hardness of an artery or tumor, but it does not have a single authoritative medical definition.

In some cases, healthcare professionals may use subjective terms like "hard," "firm," or "soft" to describe their tactile perception during a physical examination. For example, they might describe the hardness of an enlarged liver or spleen by comparing it to the feel of their knuckles when gently pressed against the abdomen.

However, in other contexts, healthcare professionals may use more objective measures of tissue stiffness or elasticity, such as palpation durometry or shear wave elastography, which provide quantitative assessments of tissue hardness. These techniques can be useful for diagnosing and monitoring conditions that affect the mechanical properties of tissues, such as liver fibrosis or cancer.

Therefore, while "hardness" may be a term used in medical contexts to describe certain physical characteristics of tissues, it does not have a single, universally accepted definition.

In the context of medical and health sciences, particle size generally refers to the diameter or dimension of particles, which can be in the form of solid particles, droplets, or aerosols. These particles may include airborne pollutants, pharmaceutical drugs, or medical devices such as nanoparticles used in drug delivery systems.

Particle size is an important factor to consider in various medical applications because it can affect the behavior and interactions of particles with biological systems. For example, smaller particle sizes can lead to greater absorption and distribution throughout the body, while larger particle sizes may be filtered out by the body's natural defense mechanisms. Therefore, understanding particle size and its implications is crucial for optimizing the safety and efficacy of medical treatments and interventions.

Acidic glycosphingolipids are a class of complex lipids that contain one or more sugar molecules (glycans) and a fatty acid attached to sphingosine, which is a type of amino alcohol. The term "acidic" refers to the presence of a negatively charged group, such as a sulfate or a carboxylic acid, in the glycan part of the molecule.

Acidic glycosphingolipids are important components of cell membranes and play a role in various biological processes, including cell recognition, signal transduction, and cell adhesion. They are also involved in the development and progression of several diseases, such as cancer, neurodegenerative disorders, and infectious diseases caused by bacteria and viruses.

Examples of acidic glycosphingolipids include sulfatides, gangliosides, and globosides, which differ in the structure and composition of their sugar chains. Abnormalities in the metabolism or function of acidic glycosphingolipids have been associated with various pathological conditions, such as lysosomal storage diseases, inflammatory disorders, and autoimmune diseases.

Electron Probe Microanalysis (EPMA) is a technique used in materials science and geology to analyze the chemical composition of materials at very small scales, typically on the order of microns or less. In this technique, a focused beam of electrons is directed at a sample, causing the emission of X-rays that are characteristic of the elements present in the sample. By analyzing the energy and intensity of these X-rays, researchers can determine the concentration of different elements in the sample with high precision and accuracy.

EPMA is typically performed using a specialized instrument called an electron probe microanalyzer (EPMA), which consists of an electron column for generating and focusing the electron beam, an X-ray spectrometer for analyzing the emitted X-rays, and a stage for positioning and manipulating the sample. The technique is widely used in fields such as mineralogy, geochemistry, metallurgy, and materials science to study the composition and structure of minerals, alloys, semiconductors, and other materials.

One of the key advantages of EPMA is its ability to analyze the chemical composition of small regions within a sample, even in cases where there are spatial variations in composition or where the sample is heterogeneous. This makes it an ideal technique for studying the distribution and behavior of trace elements in minerals, the microstructure of alloys and other materials, and the composition of individual grains or phases within a polyphase material. Additionally, EPMA can be used to analyze both conductive and non-conductive samples, making it a versatile tool for a wide range of applications.

A cell membrane, also known as the plasma membrane, is a thin semi-permeable phospholipid bilayer that surrounds all cells in animals, plants, and microorganisms. It functions as a barrier to control the movement of substances in and out of the cell, allowing necessary molecules such as nutrients, oxygen, and signaling molecules to enter while keeping out harmful substances and waste products. The cell membrane is composed mainly of phospholipids, which have hydrophilic (water-loving) heads and hydrophobic (water-fearing) tails. This unique structure allows the membrane to be flexible and fluid, yet selectively permeable. Additionally, various proteins are embedded in the membrane that serve as channels, pumps, receptors, and enzymes, contributing to the cell's overall functionality and communication with its environment.

I'm sorry for any confusion, but "Plasma Gases" is not a recognized medical term or concept. Plasma is a state of matter, like solid, liquid, or gas, and it is often referred to as the fourth state of matter. It consists of ionized particles, or particles that have been stripped of some of their electrons.

In the context of medicine, plasma is most commonly discussed in relation to blood plasma, which is the yellowish fluid in which blood cells are suspended. Plasma carries cells, hormones, nutrients, and waste products throughout the body.

If you have any questions related to medical definitions or concepts, I'd be happy to help further if I can!

Atomic Force Microscopy (AFM) is a type of microscopy that allows visualization and measurement of surfaces at the atomic level. It works by using a sharp probe, called a tip, that is mounted on a flexible cantilever. The tip is brought very close to the surface of the sample and as the sample is scanned, the forces between the tip and the sample cause the cantilever to deflect. This deflection is measured and used to generate a topographic map of the surface with extremely high resolution, often on the order of fractions of a nanometer. AFM can be used to study both conductive and non-conductive samples, and can operate in various environments, including air and liquid. It has applications in fields such as materials science, biology, and chemistry.

Aluminum oxide is a chemical compound with the formula Al2O3. It is also known as alumina and it is a white solid that is widely used in various industries due to its unique properties. Aluminum oxide is highly resistant to corrosion, has a high melting point, and is an electrical insulator.

In the medical field, aluminum oxide is used in a variety of applications such as:

1. Dental crowns and implants: Aluminum oxide is used in the production of dental crowns and implants due to its strength and durability.
2. Orthopedic implants: Aluminum oxide is used in some types of orthopedic implants, such as knee and hip replacements, because of its biocompatibility and resistance to wear.
3. Medical ceramics: Aluminum oxide is used in the production of medical ceramics, which are used in various medical devices such as pacemakers and hearing aids.
4. Pharmaceuticals: Aluminum oxide is used as an excipient in some pharmaceutical products, such as tablets and capsules, to improve their stability and shelf life.
5. Medical research: Aluminum oxide is used in medical research, for example, as a substrate material for growing cells or as a coating material for medical devices.

It's important to note that while aluminum oxide has many useful applications in the medical field, exposure to high levels of aluminum can be harmful to human health. Therefore, it is important to use aluminum oxide and other aluminum-containing materials safely and according to established guidelines.

"Pseudomonas alcaligenes" is a gram-negative, rod-shaped bacterium that is widely distributed in nature, commonly found in soil, water, and various clinical environments. It is a non-fermentative, aerobic organism that can utilize a wide range of organic compounds as its energy source.

The bacterium is motile and possesses a single polar flagellum for locomotion. It is known to be resistant to many antibiotics and disinfectants, making it a potential cause of nosocomial infections in hospital settings. However, "P. alcaligenes" is not typically considered a significant human pathogen and is rarely associated with serious diseases.

It's worth noting that there has been some controversy over the taxonomy of this bacterium, and some researchers have suggested that it may actually represent multiple distinct species. Therefore, the exact medical definition of "P. alcaligenes" may vary depending on the source and year of publication.

Fatty alcohols, also known as long-chain alcohols or long-chain fatty alcohols, are a type of fatty compound that contains a hydroxyl group (-OH) and a long alkyl chain. They are typically derived from natural sources such as plant and animal fats and oils, and can also be synthetically produced.

Fatty alcohols can vary in chain length, typically containing between 8 and 30 carbon atoms. They are commonly used in a variety of industrial and consumer products, including detergents, emulsifiers, lubricants, and personal care products. In the medical field, fatty alcohols may be used as ingredients in certain medications or topical treatments.

Nitrosomethylurethane (NMU) is not typically considered a medical term, but it is a chemical compound that has been used in research and industrial applications. It's an alkylating agent and a nitrosourea compound.

In toxicology and oncology, NMU is known as a potent carcinogen. It has been used in animal studies to induce tumors and study the mechanisms of cancer development. However, due to its high toxicity and carcinogenicity, it is not used in human medicine.

So, a medical definition might be: "Nitrosomethylurethane (NMU) is a highly toxic and carcinogenic nitrosourea compound that has been used in experimental cancer research to induce tumors in animals."

Nanoparticles are defined in the field of medicine as tiny particles that have at least one dimension between 1 to 100 nanometers (nm). They are increasingly being used in various medical applications such as drug delivery, diagnostics, and therapeutics. Due to their small size, nanoparticles can penetrate cells, tissues, and organs more efficiently than larger particles, making them ideal for targeted drug delivery and imaging.

Nanoparticles can be made from a variety of materials including metals, polymers, lipids, and dendrimers. The physical and chemical properties of nanoparticles, such as size, shape, charge, and surface chemistry, can greatly affect their behavior in biological systems and their potential medical applications.

It is important to note that the use of nanoparticles in medicine is still a relatively new field, and there are ongoing studies to better understand their safety and efficacy.

Methylmannosides are not a recognized medical term or a specific medical condition. However, in biochemistry, methylmannosides refer to a type of glycosylation pattern where a methyl group (-CH3) is attached to a mannose sugar molecule. Mannose is a type of monosaccharide or simple sugar that is commonly found in various glycoproteins and glycolipids in the human body.

Methylmannosides can be formed through the enzymatic transfer of a methyl group from a donor molecule, such as S-adenosylmethionine (SAM), to the mannose sugar by methyltransferase enzymes. These modifications can play important roles in various biological processes, including protein folding, trafficking, and quality control, as well as cell-cell recognition and signaling.

It's worth noting that while methylmannosides have significant biochemical importance, they are not typically referred to in medical contexts unless discussing specific biochemical or molecular research studies.

'Adhesiveness' is a term used in medicine and biology to describe the ability of two surfaces to stick or adhere to each other. In medical terms, it often refers to the property of tissues or cells to adhere to one another, as in the case of scar tissue formation where healing tissue adheres to adjacent structures.

In the context of microbiology, adhesiveness can refer to the ability of bacteria or other microorganisms to attach themselves to surfaces, such as medical devices or human tissues, which can lead to infection and other health problems. Adhesives used in medical devices, such as bandages or wound dressings, also have adhesiveness properties that allow them to stick to the skin or other surfaces.

Overall, adhesiveness is an important property in many areas of medicine and biology, with implications for wound healing, infection control, and the design and function of medical devices.

I'm sorry for any confusion, but "Glass" is not a medical term. Glass is a non-crystalline amorphous solid that is often transparent and has various uses in everyday life, including medical devices and equipment. If you have any questions related to medical terminology or concepts, please provide them, and I'll be happy to help.

Concanavalin A (Con A) receptors are not a medical term per se, but rather a term used in the field of immunology and cell biology. Concanavalin A is a type of lectin, a protein that can bind to specific sugars found on the surface of cells. Con A receptors refer to the specific binding sites or proteins on the surface of certain types of cells, such as immune cells, that can recognize and bind to Concanavalin A.

When Con A binds to its receptors, it can activate various cellular responses, including changes in cell shape, movement, and metabolism. In research settings, Con A is often used as a tool to study the behavior of immune cells and other cell types that express Con A receptors. However, it's worth noting that Concanavalin A is not typically used in medical treatments or diagnoses.

Medical definitions of water generally describe it as a colorless, odorless, tasteless liquid that is essential for all forms of life. It is a universal solvent, making it an excellent medium for transporting nutrients and waste products within the body. Water constitutes about 50-70% of an individual's body weight, depending on factors such as age, sex, and muscle mass.

In medical terms, water has several important functions in the human body:

1. Regulation of body temperature through perspiration and respiration.
2. Acting as a lubricant for joints and tissues.
3. Facilitating digestion by helping to break down food particles.
4. Transporting nutrients, oxygen, and waste products throughout the body.
5. Helping to maintain healthy skin and mucous membranes.
6. Assisting in the regulation of various bodily functions, such as blood pressure and heart rate.

Dehydration can occur when an individual does not consume enough water or loses too much fluid due to illness, exercise, or other factors. This can lead to a variety of symptoms, including dry mouth, fatigue, dizziness, and confusion. Severe dehydration can be life-threatening if left untreated.

Congo Red is a synthetic diazo dye that is commonly used in histology and pathology for stainings and tests. It is particularly useful in identifying amyloid deposits in tissues, which are associated with various diseases such as Alzheimer's disease, type 2 diabetes, and systemic amyloidosis.

When Congo Red binds to amyloid fibrils, it exhibits a characteristic apple-green birefringence under polarized light microscopy. Additionally, Congo Red stained amyloid deposits show a shift in their emission spectrum when excited with circularly polarized light, a phenomenon known as dichroism. These properties make Congo Red a valuable tool for the diagnosis and study of amyloidosis and other protein misfolding disorders.

It is important to note that Congo Red staining should be performed with care, as it can be toxic and carcinogenic if not handled properly.

In the context of medical definitions, polymers are large molecules composed of repeating subunits called monomers. These long chains of monomers can have various structures and properties, depending on the type of monomer units and how they are linked together. In medicine, polymers are used in a wide range of applications, including drug delivery systems, medical devices, and tissue engineering scaffolds. Some examples of polymers used in medicine include polyethylene, polypropylene, polystyrene, polyvinyl chloride (PVC), and biodegradable polymers such as polylactic acid (PLA) and polycaprolactone (PCL).

Silicon compounds refer to chemical substances that contain the element silicon (Si) combined with other elements. Silicon is a Group 14 semimetal in the periodic table, and it often forms compounds through covalent bonding. The most common silicon compound is silicon dioxide (SiO2), also known as silica, which is found in nature as quartz, sand, and other minerals.

Silicon can form compounds with many other elements, including hydrogen, oxygen, halogens, sulfur, nitrogen, and carbon. For example:

* Silanes (SiHn) are a series of silicon-hydrogen compounds where n ranges from 1 to 6.
* Silicones are synthetic polymers made up of alternating silicon and oxygen atoms with organic groups attached to the silicon atoms.
* Silicates are a class of minerals that contain silicon, oxygen, and one or more metal cations. They have a wide range of structures and uses, including as building materials, ceramics, and glass.
* Siloxanes are a group of compounds containing alternating silicon-oxygen bonds with organic groups attached to the silicon atoms.

Silicon compounds have various applications in industry, medicine, and daily life. For instance, silicones are used in medical devices such as breast implants, contact lenses, and catheters due to their biocompatibility and flexibility. Silicates are found in pharmaceuticals, cosmetics, and food additives. Silicon-based materials are also used in dental restorations, bone cement, and drug delivery systems.

Streptococcus mitis is a species of gram-positive, beta-hemolytic streptococci that are part of the viridans group streptococci (VGS). It is a normal commensal of the human oral cavity, upper respiratory tract, and gastrointestinal tract. However, it can occasionally cause invasive infections such as bacteremia, endocarditis, and meningitis, particularly in immunocompromised individuals or those with underlying medical conditions. S. mitis is also known to be a significant contributor to dental caries. It is often misidentified as Streptococcus sanguinis due to their similar phenotypic characteristics. Accurate identification of this organism is important because of its potential to cause invasive disease and its resistance to some antibiotics.

I'm sorry for any confusion, but static electricity is not a term that has a specific medical definition. Static electricity is an electrical charge that builds up on the surface of objects. This occurs when there is an imbalance of electric charges within or on the surface of a material. It can be caused by certain conditions, such as friction, which can build up an electric charge.

While not a medical term, static electricity can have various effects in different settings, including medical ones. For instance, it can cause issues with electronic equipment used in healthcare settings. Additionally, some people may experience a shock or spark when they touch a conductive object that has been charged with static electricity. However, these occurrences are not typically considered medical conditions or issues.

The dental casting technique is a method used in dentistry to create accurate replicas or reproductions of teeth and oral structures. This process typically involves the following steps:

1. Making an impression: A dental professional takes an impression of the patient's teeth and oral structures using a special material, such as alginate or polyvinyl siloxane. The impression material captures the precise shape and contours of the teeth and surrounding tissues.
2. Pouring the cast: The impression is then filled with a casting material, such as gypsum-based stone, which hardens to form a positive model or replica of the teeth and oral structures. This model is called a dental cast or die.
3. Examining and modifying the cast: The dental cast can be used for various purposes, such as analyzing the patient's bite, planning treatment, fabricating dental appliances, or creating study models for teaching or research purposes. Dental professionals may also modify the cast to simulate various conditions or treatments.
4. Replicating the process: In some cases, multiple casts may be made from a single impression, allowing dental professionals to create identical replicas of the patient's teeth and oral structures. This can be useful for comparing changes over time, creating duplicate appliances, or sharing information with other dental professionals involved in the patient's care.

The dental casting technique is an essential part of many dental procedures, as it enables dentists to accurately assess, plan, and implement treatments based on the unique characteristics of each patient's oral structures.

In the context of medical terminology, 'color' is not defined specifically with a unique meaning. Instead, it generally refers to the characteristic or appearance of something, particularly in relation to the color that a person may observe visually. For instance, doctors may describe the color of a patient's skin, eyes, hair, or bodily fluids to help diagnose medical conditions or monitor their progression.

For example, jaundice is a yellowing of the skin and whites of the eyes that can indicate liver problems, while cyanosis refers to a bluish discoloration of the skin and mucous membranes due to insufficient oxygen in the blood. Similarly, doctors may describe the color of stool or urine to help diagnose digestive or kidney issues.

Therefore, 'color' is not a medical term with a specific definition but rather a general term used to describe various visual characteristics of the body and bodily fluids that can provide important diagnostic clues for healthcare professionals.

Poloxamers are a type of triblock copolymer made up of a central hydrophobic chain of polyoxypropylene (poly(propylene oxide)) flanked by two hydrophilic chains of polyoxyethylene (poly(ethylene oxide)). They are amphiphilic molecules, meaning they have both hydrophilic and hydrophobic parts.

Poloxamers are often used in the pharmaceutical industry as drug delivery agents, emulsifiers, solubilizers, and stabilizers. They can form micelles in aqueous solutions above their critical micelle concentration (CMC), with the hydrophobic chains oriented toward the interior of the micelle and the hydrophilic chains on the exterior, interacting with the water molecules. This unique property allows poloxamers to solubilize drugs that are otherwise poorly soluble in water, improving their bioavailability.

Poloxamers have been studied for various medical applications, including as drug carriers for chemotherapy, diagnostic agents, and mucoadhesive materials. Some specific poloxamer compounds have been approved by the FDA for use in pharmaceutical formulations, such as Poloxamer 188 and Poloxamer 407.

In a medical context, poloxamers are not typically used as standalone treatments but rather as components of drug delivery systems or formulations.

Electrophoresis is a laboratory technique used in the field of molecular biology and chemistry to separate charged particles, such as DNA, RNA, or proteins, based on their size and charge. This technique uses an electric field to drive the movement of these charged particles through a medium, such as gel or liquid.

In electrophoresis, the sample containing the particles to be separated is placed in a matrix, such as a gel or a capillary tube, and an electric current is applied. The particles in the sample have a net charge, either positive or negative, which causes them to move through the matrix towards the oppositely charged electrode.

The rate at which the particles move through the matrix depends on their size and charge. Larger particles move more slowly than smaller ones, and particles with a higher charge-to-mass ratio move faster than those with a lower charge-to-mass ratio. By comparing the distance that each particle travels in the matrix, researchers can identify and quantify the different components of a mixture.

Electrophoresis has many applications in molecular biology and medicine, including DNA sequencing, genetic fingerprinting, protein analysis, and diagnosis of genetic disorders.

Solubility is a fundamental concept in pharmaceutical sciences and medicine, which refers to the maximum amount of a substance (solute) that can be dissolved in a given quantity of solvent (usually water) at a specific temperature and pressure. Solubility is typically expressed as mass of solute per volume or mass of solvent (e.g., grams per liter, milligrams per milliliter). The process of dissolving a solute in a solvent results in a homogeneous solution where the solute particles are dispersed uniformly throughout the solvent.

Understanding the solubility of drugs is crucial for their formulation, administration, and therapeutic effectiveness. Drugs with low solubility may not dissolve sufficiently to produce the desired pharmacological effect, while those with high solubility might lead to rapid absorption and short duration of action. Therefore, optimizing drug solubility through various techniques like particle size reduction, salt formation, or solubilization is an essential aspect of drug development and delivery.

Dimethylpolysiloxanes are a type of silicone-based compound that are often used as lubricants, coatings, and fluid ingredients in various industrial and consumer products. In medical terms, they can be found in some pharmaceutical and medical device formulations as inactive ingredients. They are typically included as anti-foaming agents or to improve the texture and consistency of a product.

Dimethylpolysiloxanes are made up of long chains of silicon and oxygen atoms, with methyl groups (CH3) attached to the silicon atoms. This gives them unique properties such as low toxicity, thermal stability, and resistance to oxidation and water absorption. However, some people may have allergic reactions or sensitivities to dimethylpolysiloxanes, so they should be used with caution in medical applications.

1,2-Dipalmitoylphosphatidylcholine (DPPC) is a type of phospholipid molecule that is a major component of the lipid bilayer in biological membranes, particularly in lung surfactant. It is composed of two palmitic acid chains attached to a glycerol backbone, which is linked to a phosphate group and a choline headgroup. The chemical formula for DPPC is C44H86NO8P.

In the body, DPPC plays an important role in maintaining the structure and function of cell membranes, as well as reducing surface tension in the lungs. It is also used in research and medical settings as a component of liposomes, which are used for drug delivery and other biomedical applications.

Polyethylene glycols (PEGs) are a family of synthetic, water-soluble polymers with a wide range of molecular weights. They are commonly used in the medical field as excipients in pharmaceutical formulations due to their ability to improve drug solubility, stability, and bioavailability. PEGs can also be used as laxatives to treat constipation or as bowel cleansing agents prior to colonoscopy examinations. Additionally, some PEG-conjugated drugs have been developed for use in targeted cancer therapies.

In a medical context, PEGs are often referred to by their average molecular weight, such as PEG 300, PEG 400, PEG 1500, and so on. Higher molecular weight PEGs tend to be more viscous and have longer-lasting effects in the body.

It's worth noting that while PEGs are generally considered safe for use in medical applications, some people may experience allergic reactions or hypersensitivity to these compounds. Prolonged exposure to high molecular weight PEGs has also been linked to potential adverse effects, such as decreased fertility and developmental toxicity in animal studies. However, more research is needed to fully understand the long-term safety of PEGs in humans.

Prostheses: Artificial substitutes or replacements for missing body parts, such as limbs, eyes, or teeth. They are designed to restore the function, appearance, or mobility of the lost part. Prosthetic devices can be categorized into several types, including:

1. External prostheses: Devices that are attached to the outside of the body, like artificial arms, legs, hands, and feet. These may be further classified into:
a. Cosmetic or aesthetic prostheses: Primarily designed to improve the appearance of the affected area.
b. Functional prostheses: Designed to help restore the functionality and mobility of the lost limb.
2. Internal prostheses: Implanted artificial parts that replace missing internal organs, bones, or tissues, such as heart valves, hip joints, or intraocular lenses.

Implants: Medical devices or substances that are intentionally placed inside the body to replace or support a missing or damaged biological structure, deliver medication, monitor physiological functions, or enhance bodily functions. Examples of implants include:

1. Orthopedic implants: Devices used to replace or reinforce damaged bones, joints, or cartilage, such as knee or hip replacements.
2. Cardiovascular implants: Devices that help support or regulate heart function, like pacemakers, defibrillators, and artificial heart valves.
3. Dental implants: Artificial tooth roots that are placed into the jawbone to support dental prostheses, such as crowns, bridges, or dentures.
4. Neurological implants: Devices used to stimulate nerves, brain structures, or spinal cord tissues to treat various neurological conditions, like deep brain stimulators for Parkinson's disease or cochlear implants for hearing loss.
5. Ophthalmic implants: Artificial lenses that are placed inside the eye to replace a damaged or removed natural lens, such as intraocular lenses used in cataract surgery.

Surfactants, also known as surface-active agents, are amphiphilic compounds that reduce the surface tension between two liquids or between a liquid and a solid. They contain both hydrophilic (water-soluble) and hydrophobic (water-insoluble) components in their molecular structure. This unique property allows them to interact with and stabilize interfaces, making them useful in various medical and healthcare applications.

In the medical field, surfactants are commonly used in pulmonary medicine, particularly for treating respiratory distress syndrome (RDS) in premature infants. The lungs of premature infants often lack sufficient amounts of natural lung surfactant, which can lead to RDS and other complications. Exogenous surfactants, derived from animal sources or synthetically produced, are administered to replace the missing or dysfunctional lung surfactant, improving lung compliance and gas exchange.

Surfactants also have applications in topical formulations for dermatology, as they can enhance drug penetration into the skin, reduce irritation, and improve the spreadability of creams and ointments. Additionally, they are used in diagnostic imaging to enhance contrast between tissues and improve visualization during procedures such as ultrasound and X-ray examinations.

Electricity is not a medical term, but rather a fundamental aspect of physics and science. It refers to the form of energy resulting from the existence of charged particles such as electrons or protons, either statically as an accumulation of charge or dynamically as a current.

However, in the context of medical procedures and treatments, electricity is often used to stimulate nerves or muscles, destroy tissue through processes like electrocoagulation, or generate images of internal structures using methods like electrocardiography (ECG) or electroencephalography (EEG). In these cases, a clear medical definition would be:

The use of electric currents or fields in medical procedures for therapeutic or diagnostic purposes.

Alkanes are a group of saturated hydrocarbons, which are characterized by the presence of single bonds between carbon atoms in their molecular structure. The general formula for alkanes is CnH2n+2, where n represents the number of carbon atoms in the molecule.

The simplest and shortest alkane is methane (CH4), which contains one carbon atom and four hydrogen atoms. As the number of carbon atoms increases, the length and complexity of the alkane chain also increase. For example, ethane (C2H6) contains two carbon atoms and six hydrogen atoms, while propane (C3H8) contains three carbon atoms and eight hydrogen atoms.

Alkanes are important components of fossil fuels such as natural gas, crude oil, and coal. They are also used as starting materials in the production of various chemicals and materials, including plastics, fertilizers, and pharmaceuticals. In the medical field, alkanes may be used as anesthetics or as solvents for various medical applications.

X-ray emission spectrometry is a technique used to analyze the elements present in a sample by measuring the characteristic X-rays that are emitted when the sample is bombarded with high-energy X-rays or charged particles. The sample is excited to emit X-rays, which have specific energies (wavelengths) that correspond to the energy levels of the electrons in the atoms of the elements present in the sample. These X-ray emissions are then detected and analyzed using a spectrometer, which separates and measures the intensity of the different X-ray energies. The resulting spectrum provides information about the identity and quantity of the elements present in the sample. This technique is widely used in materials analysis, particularly for the identification and quantification of heavy metals and other elements in a variety of samples, including geological, biological, and industrial materials.

Biofilms are defined as complex communities of microorganisms, such as bacteria and fungi, that adhere to surfaces and are enclosed in a matrix made up of extracellular polymeric substances (EPS). The EPS matrix is composed of polysaccharides, proteins, DNA, and other molecules that provide structural support and protection to the microorganisms within.

Biofilms can form on both living and non-living surfaces, including medical devices, implants, and biological tissues. They are resistant to antibiotics, disinfectants, and host immune responses, making them difficult to eradicate and a significant cause of persistent infections. Biofilms have been implicated in a wide range of medical conditions, including chronic wounds, urinary tract infections, middle ear infections, and device-related infections.

The formation of biofilms typically involves several stages, including initial attachment, microcolony formation, maturation, and dispersion. Understanding the mechanisms underlying biofilm formation and development is crucial for developing effective strategies to prevent and treat biofilm-associated infections.

Phosphatidylglycerols are a type of glycerophospholipids, which are major components of biological membranes. They are composed of a glycerol backbone to which two fatty acid chains and a phosphate group are attached. In the case of phosphatidylglycerols, the phosphate group is linked to a glycerol molecule through an ester bond, forming a phosphoglyceride.

Phosphatidylglycerols are unique because they have an additional glycerol molecule attached to the phosphate group, making them more complex than other glycerophospholipids such as phosphatidylcholine or phosphatidylethanolamine. This additional glycerol moiety can be further modified by the addition of various headgroups, leading to the formation of different subclasses of phosphatidylglycerols.

In biological membranes, phosphatidylglycerols are often found in the inner leaflet of the mitochondrial membrane and play important roles in maintaining the structure and function of this organelle. They have also been implicated in various cellular processes such as membrane fusion, protein trafficking, and bacterial cell wall biosynthesis.

"Physicochemical phenomena" is not a term that has a specific medical definition. However, in general terms, physicochemical phenomena refer to the physical and chemical interactions and processes that occur within living organisms or biological systems. These phenomena can include various properties and reactions such as pH levels, osmotic pressure, enzyme kinetics, and thermodynamics, among others.

In a broader context, physicochemical phenomena play an essential role in understanding the mechanisms of drug action, pharmacokinetics, and toxicity. For instance, the solubility, permeability, and stability of drugs are all physicochemical properties that can affect their absorption, distribution, metabolism, and excretion (ADME) within the body.

Therefore, while not a medical definition per se, an understanding of physicochemical phenomena is crucial to the study and practice of pharmacology, toxicology, and other related medical fields.

Dental etching is a dental procedure that involves the use of a chemical agent, such as phosphoric or maleic acid, to create microscopic roughness on the surface of teeth. This process is typically used to prepare the tooth enamel for the application of bonding agents, such as dental adhesives and composite resins, which are used in various restorative and cosmetic dental procedures, such as fillings, veneers, and crowns.

During dental etching, the chemical agent is applied to the tooth surface for a specific amount of time, usually between 15-60 seconds, depending on the strength of the acid and the desired level of etching. The acid dissolves the minerals in the enamel, creating small pores or irregularities that increase the surface area and improve the bonding of the restorative material to the tooth. After etching, the tooth is rinsed with water and dried, and the bonding agent is applied and cured to create a strong and durable bond between the restoration and the tooth.

Dental etching is a safe and effective procedure when performed by a trained dental professional. However, over-etching or improper use of the acid can weaken the tooth structure and lead to sensitivity or other complications. Therefore, it is important to follow proper techniques and guidelines for dental etching to ensure optimal outcomes and patient satisfaction.

Agglutination is a medical term that refers to the clumping together of particles, such as cells, bacteria, or precipitates, in a liquid medium. It most commonly occurs due to the presence of antibodies in the fluid that bind to specific antigens on the surface of the particles, causing them to adhere to one another and form visible clumps.

In clinical laboratory testing, agglutination is often used as a diagnostic tool to identify the presence of certain antibodies or antigens in a patient's sample. For example, a common application of agglutination is in blood typing, where the presence of specific antigens on the surface of red blood cells causes them to clump together when mixed with corresponding antibodies.

Agglutination can also occur in response to certain infectious agents, such as bacteria or viruses, that display antigens on their surface. In these cases, the agglutination reaction can help diagnose an infection and guide appropriate treatment.

Fourier Transform Infrared (FTIR) spectroscopy is a type of infrared spectroscopy that uses the Fourier transform mathematical technique to convert the raw data obtained from an interferometer into a more interpretable spectrum. This technique allows for the simultaneous collection of a wide range of wavelengths, resulting in increased sensitivity and speed compared to traditional dispersive infrared spectroscopy.

FTIR spectroscopy measures the absorption or transmission of infrared radiation by a sample as a function of frequency, providing information about the vibrational modes of the molecules present in the sample. This can be used for identification and quantification of chemical compounds, analysis of molecular structure, and investigation of chemical interactions and reactions.

In summary, FTIR spectroscopy is a powerful analytical technique that uses infrared radiation to study the vibrational properties of molecules, with increased sensitivity and speed due to the use of Fourier transform mathematical techniques and an interferometer.

Biocompatible coated materials refer to surfaces or substances that are treated or engineered with a layer or film designed to interact safely and effectively with living tissues or biological systems, without causing harm or adverse reactions. The coating material is typically composed of biomaterials that can withstand the conditions of the specific application while promoting a positive response from the body.

The purpose of these coatings may vary depending on the medical device or application. For example, they might be used to enhance the lubricity and wear resistance of implantable devices, reduce the risk of infection, promote integration with surrounding tissues, control drug release, or prevent the formation of biofilms.

Biocompatible coated materials must undergo rigorous testing and evaluation to ensure their safety and efficacy in various clinical settings. This includes assessing potential cytotoxicity, genotoxicity, sensitization, hemocompatibility, carcinogenicity, and other factors that could impact the body's response to the material.

Examples of biocompatible coating materials include:

1. Hydrogels: Cross-linked networks of hydrophilic polymers that can be used for drug delivery, tissue engineering, or as lubricious coatings on medical devices.
2. Self-assembling monolayers (SAMs): Organosilane or thiol-based molecules that form a stable, well-ordered film on surfaces, which can be further functionalized to promote specific biological interactions.
3. Poly(ethylene glycol) (PEG): A biocompatible polymer often used as a coating material due to its ability to reduce protein adsorption and cell attachment, making it useful for preventing biofouling or thrombosis on medical devices.
4. Bioactive glass: A type of biomaterial composed of silica-based glasses that can stimulate bone growth and healing when used as a coating material in orthopedic or dental applications.
5. Drug-eluting coatings: Biocompatible polymers impregnated with therapeutic agents, designed to release the drug over time to promote healing, prevent infection, or inhibit restenosis in various medical devices.

Artificial membranes are synthetic or man-made materials that possess properties similar to natural biological membranes, such as selective permeability and barrier functions. These membranes can be designed to control the movement of molecules, ions, or cells across them, making them useful in various medical and biotechnological applications.

Examples of artificial membranes include:

1. Dialysis membranes: Used in hemodialysis for patients with renal failure, these semi-permeable membranes filter waste products and excess fluids from the blood while retaining essential proteins and cells.
2. Hemofiltration membranes: Utilized in extracorporeal circuits to remove larger molecules, such as cytokines or inflammatory mediators, from the blood during critical illnesses or sepsis.
3. Drug delivery systems: Artificial membranes can be used to encapsulate drugs, allowing for controlled release and targeted drug delivery in specific tissues or cells.
4. Tissue engineering: Synthetic membranes serve as scaffolds for cell growth and tissue regeneration, guiding the formation of new functional tissues.
5. Biosensors: Artificial membranes can be integrated into biosensing devices to selectively detect and quantify biomolecules, such as proteins or nucleic acids, in diagnostic applications.
6. Microfluidics: Artificial membranes are used in microfluidic systems for lab-on-a-chip applications, enabling the manipulation and analysis of small volumes of fluids for various medical and biological purposes.

In the context of medical terminology, "powders" do not have a specific technical definition. However, in a general sense, powders refer to dry, finely ground or pulverized solid substances that can be dispersed in air or liquid mediums. In medicine, powders may include various forms of medications, such as crushed tablets or capsules, which are intended to be taken orally, mixed with liquids, or applied topically. Additionally, certain medical treatments and therapies may involve the use of medicated powders for various purposes, such as drying agents, abrasives, or delivery systems for active ingredients.

Physical chemistry is a branch of chemistry that deals with the fundamental principles and laws governing the behavior of matter and energy at the molecular and atomic levels. It combines elements of physics, chemistry, mathematics, and engineering to study the properties, composition, structure, and transformation of matter. Key areas of focus in physical chemistry include thermodynamics, kinetics, quantum mechanics, statistical mechanics, electrochemistry, and spectroscopy.

In essence, physical chemists aim to understand how and why chemical reactions occur, what drives them, and how they can be controlled or predicted. This knowledge is crucial for developing new materials, medicines, energy technologies, and other applications that benefit society.

Form perception, also known as shape perception, is not a term that has a specific medical definition. However, in the field of neuropsychology and sensory perception, form perception refers to the ability to recognize and interpret different shapes and forms of objects through visual processing. This ability is largely dependent on the integrity of the visual cortex and its ability to process and interpret information received from the retina.

Damage to certain areas of the brain, particularly in the occipital and parietal lobes, can result in deficits in form perception, leading to difficulties in recognizing and identifying objects based on their shape or form. This condition is known as visual agnosia and can be a symptom of various neurological disorders such as stroke, brain injury, or degenerative diseases like Alzheimer's disease.

Polyglycolic acid (PGA) is a synthetic polymer of glycolic acid, which is commonly used in surgical sutures. It is a biodegradable material that degrades in the body through hydrolysis into glycolic acid, which can be metabolized and eliminated from the body. PGA sutures are often used for approximating tissue during surgical procedures due to their strength, handling properties, and predictable rate of absorption. The degradation time of PGA sutures is typically around 60-90 days, depending on factors such as the size and location of the suture.

Cell adhesion refers to the binding of cells to extracellular matrices or to other cells, a process that is fundamental to the development, function, and maintenance of multicellular organisms. Cell adhesion is mediated by various cell surface receptors, such as integrins, cadherins, and immunoglobulin-like cell adhesion molecules (Ig-CAMs), which interact with specific ligands in the extracellular environment. These interactions lead to the formation of specialized junctions, such as tight junctions, adherens junctions, and desmosomes, that help to maintain tissue architecture and regulate various cellular processes, including proliferation, differentiation, migration, and survival. Disruptions in cell adhesion can contribute to a variety of diseases, including cancer, inflammation, and degenerative disorders.

Excipients are inactive substances that serve as vehicles or mediums for the active ingredients in medications. They make up the bulk of a pharmaceutical formulation and help to stabilize, preserve, and enhance the delivery of the active drug compound. Common examples of excipients include binders, fillers, coatings, disintegrants, flavors, sweeteners, and colors. While excipients are generally considered safe and inert, they can sometimes cause allergic reactions or other adverse effects in certain individuals.

Dental materials are substances that are used in restorative dentistry, prosthodontics, endodontics, orthodontics, and preventive dentistry to restore or replace missing tooth structure, improve the function and esthetics of teeth, and protect the oral tissues from decay and disease. These materials can be classified into various categories based on their physical and chemical properties, including metals, ceramics, polymers, composites, cements, and alloys.

Some examples of dental materials include:

1. Amalgam: a metal alloy used for dental fillings that contains silver, tin, copper, and mercury. It is strong, durable, and resistant to wear but has been controversial due to concerns about the toxicity of mercury.
2. Composite: a tooth-colored restorative material made of a mixture of glass or ceramic particles and a bonding agent. It is used for fillings, veneers, and other esthetic dental treatments.
3. Glass ionomer cement: a type of cement used for dental restorations that releases fluoride ions and helps prevent tooth decay. It is often used for fillings in children's teeth or as a base under crowns and bridges.
4. Porcelain: a ceramic material used for dental crowns, veneers, and other esthetic restorations. It is strong, durable, and resistant to staining but can be brittle and prone to fracture.
5. Gold alloy: a metal alloy used for dental restorations that contains gold, copper, and other metals. It is highly biocompatible, corrosion-resistant, and malleable but can be expensive and less esthetic than other materials.
6. Acrylic resin: a type of polymer used for dental appliances such as dentures, night guards, and orthodontic retainers. It is lightweight, flexible, and easy to modify but can be less durable than other materials.

The choice of dental material depends on various factors, including the location and extent of the restoration, the patient's oral health status, their esthetic preferences, and their budget. Dental professionals must consider these factors carefully when selecting the appropriate dental material for each individual case.

A cell wall is a rigid layer found surrounding the plasma membrane of plant cells, fungi, and many types of bacteria. It provides structural support and protection to the cell, maintains cell shape, and acts as a barrier against external factors such as chemicals and mechanical stress. The composition of the cell wall varies among different species; for example, in plants, it is primarily made up of cellulose, hemicellulose, and pectin, while in bacteria, it is composed of peptidoglycan.

Electron microscopy (EM) is a type of microscopy that uses a beam of electrons to create an image of the sample being examined, resulting in much higher magnification and resolution than light microscopy. There are several types of electron microscopy, including transmission electron microscopy (TEM), scanning electron microscopy (SEM), and reflection electron microscopy (REM).

In TEM, a beam of electrons is transmitted through a thin slice of the sample, and the electrons that pass through the sample are focused to form an image. This technique can provide detailed information about the internal structure of cells, viruses, and other biological specimens, as well as the composition and structure of materials at the atomic level.

In SEM, a beam of electrons is scanned across the surface of the sample, and the electrons that are scattered back from the surface are detected to create an image. This technique can provide information about the topography and composition of surfaces, as well as the structure of materials at the microscopic level.

REM is a variation of SEM in which the beam of electrons is reflected off the surface of the sample, rather than scattered back from it. This technique can provide information about the surface chemistry and composition of materials.

Electron microscopy has a wide range of applications in biology, medicine, and materials science, including the study of cellular structure and function, disease diagnosis, and the development of new materials and technologies.

Silicon dioxide is not a medical term, but a chemical compound with the formula SiO2. It's commonly known as quartz or sand and is not something that would typically have a medical definition. However, in some cases, silicon dioxide can be used in pharmaceutical preparations as an excipient (an inactive substance that serves as a vehicle or medium for a drug) or as a food additive, often as an anti-caking agent.

In these contexts, it's important to note that silicon dioxide is considered generally recognized as safe (GRAS) by the U.S. Food and Drug Administration (FDA). However, exposure to very high levels of respirable silica dust, such as in certain industrial settings, can increase the risk of lung disease, including silicosis.

Biomimetic materials are synthetic or natural substances that mimic the chemical, physical, and biological properties of living systems or tissues. These materials are designed to interact with cells, tissues, and organs in ways that resemble the body's own structures and processes. They can be used in a variety of medical applications, including tissue engineering, drug delivery, and medical devices.

Biomimetic materials may be composed of polymers, ceramics, metals, or composites, and they can be designed to have specific properties such as mechanical strength, biocompatibility, and degradability. They may also incorporate bioactive molecules, such as growth factors or drugs, to promote healing or prevent infection.

The goal of using biomimetic materials is to create medical solutions that are more effective, safer, and more compatible with the body than traditional synthetic materials. By mimicking the body's own structures and processes, these materials can help to reduce inflammation, promote tissue regeneration, and improve overall patient outcomes.

Dextrans are a type of complex glucose polymers that are formed by the action of certain bacteria on sucrose. They are branched polysaccharides consisting of linear chains of α-1,6 linked D-glucopyranosyl units with occasional α-1,3 branches.

Dextrans have a wide range of applications in medicine and industry. In medicine, dextrans are used as plasma substitutes, volume expanders, and anticoagulants. They are also used as carriers for drugs and diagnostic agents, and in the manufacture of immunoadsorbents for the removal of toxins and pathogens from blood.

Dextrans can be derived from various bacterial sources, but the most common commercial source is Leuconostoc mesenteroides B-512(F) or L. dextranicum. The molecular weight of dextrans can vary widely, ranging from a few thousand to several million Daltons, depending on the method of preparation and purification.

Dextrans are generally biocompatible and non-toxic, but they can cause allergic reactions in some individuals. Therefore, their use as medical products requires careful monitoring and testing for safety and efficacy.

Phagocytosis is the process by which certain cells in the body, known as phagocytes, engulf and destroy foreign particles, bacteria, or dead cells. This mechanism plays a crucial role in the immune system's response to infection and inflammation. Phagocytes, such as neutrophils, monocytes, and macrophages, have receptors on their surface that recognize and bind to specific molecules (known as antigens) on the target particles or microorganisms.

Once attached, the phagocyte extends pseudopodia (cell extensions) around the particle, forming a vesicle called a phagosome that completely encloses it. The phagosome then fuses with a lysosome, an intracellular organelle containing digestive enzymes and other chemicals. This fusion results in the formation of a phagolysosome, where the engulfed particle is broken down by the action of these enzymes, neutralizing its harmful effects and allowing for the removal of cellular debris or pathogens.

Phagocytosis not only serves as a crucial defense mechanism against infections but also contributes to tissue homeostasis by removing dead cells and debris.

Hydrogen-ion concentration, also known as pH, is a measure of the acidity or basicity of a solution. It is defined as the negative logarithm (to the base 10) of the hydrogen ion activity in a solution. The standard unit of measurement is the pH unit. A pH of 7 is neutral, less than 7 is acidic, and greater than 7 is basic.

In medical terms, hydrogen-ion concentration is important for maintaining homeostasis within the body. For example, in the stomach, a high hydrogen-ion concentration (low pH) is necessary for the digestion of food. However, in other parts of the body such as blood, a high hydrogen-ion concentration can be harmful and lead to acidosis. Conversely, a low hydrogen-ion concentration (high pH) in the blood can lead to alkalosis. Both acidosis and alkalosis can have serious consequences on various organ systems if not corrected.

Temperature, in a medical context, is a measure of the degree of hotness or coldness of a body or environment. It is usually measured using a thermometer and reported in degrees Celsius (°C), degrees Fahrenheit (°F), or kelvin (K). In the human body, normal core temperature ranges from about 36.5-37.5°C (97.7-99.5°F) when measured rectally, and can vary slightly depending on factors such as time of day, physical activity, and menstrual cycle. Elevated body temperature is a common sign of infection or inflammation, while abnormally low body temperature can indicate hypothermia or other medical conditions.

Culture media is a substance that is used to support the growth of microorganisms or cells in an artificial environment, such as a petri dish or test tube. It typically contains nutrients and other factors that are necessary for the growth and survival of the organisms being cultured. There are many different types of culture media, each with its own specific formulation and intended use. Some common examples include blood agar, which is used to culture bacteria; Sabouraud dextrose agar, which is used to culture fungi; and Eagle's minimum essential medium, which is used to culture animal cells.

Microspheres are tiny, spherical particles that range in size from 1 to 1000 micrometers in diameter. They are made of biocompatible and biodegradable materials such as polymers, glass, or ceramics. In medical terms, microspheres have various applications, including drug delivery systems, medical imaging, and tissue engineering.

In drug delivery, microspheres can be used to encapsulate drugs and release them slowly over time, improving the efficacy of the treatment while reducing side effects. They can also be used for targeted drug delivery, where the microspheres are designed to accumulate in specific tissues or organs.

In medical imaging, microspheres can be labeled with radioactive isotopes or magnetic materials and used as contrast agents to enhance the visibility of tissues or organs during imaging procedures such as X-ray, CT, MRI, or PET scans.

In tissue engineering, microspheres can serve as a scaffold for cell growth and differentiation, promoting the regeneration of damaged tissues or organs. Overall, microspheres have great potential in various medical applications due to their unique properties and versatility.

Nanotechnology is not a medical term per se, but it is a field of study with potential applications in medicine. According to the National Nanotechnology Initiative, nanotechnology is defined as "the understanding and control of matter at the nanoscale, at dimensions between approximately 1 and 100 nanometers, where unique phenomena enable novel applications."

In the context of medicine, nanotechnology has the potential to revolutionize the way we diagnose, treat, and prevent diseases. Nanomedicine involves the use of nanoscale materials, devices, or systems for medical applications. These can include drug delivery systems that target specific cells or tissues, diagnostic tools that detect biomarkers at the molecular level, and tissue engineering strategies that promote regeneration and repair.

While nanotechnology holds great promise for medicine, it is still a relatively new field with many challenges to overcome, including issues related to safety, regulation, and scalability.

Bacterial fimbriae are thin, hair-like protein appendages that extend from the surface of many types of bacteria. They are involved in the attachment of bacteria to surfaces, other cells, or extracellular structures. Fimbriae enable bacteria to adhere to host tissues and form biofilms, which contribute to bacterial pathogenicity and survival in various environments. These protein structures are composed of several thousand subunits of a specific protein called pilin. Some fimbriae can recognize and bind to specific receptors on host cells, initiating the process of infection and colonization.

Medical definitions generally refer to terms and concepts within the medical field. The term "metal nanoparticles" is more commonly used in materials science, chemistry, and physics. However, I can provide a general scientific definition that could be relevant to medical applications:

Metal nanoparticles are tiny particles with at least one dimension ranging from 1 to 100 nanometers (nm), composed of metals or metal compounds. They have unique optical, electronic, and chemical properties due to their small size and high surface-to-volume ratio, making them useful in various fields, including medical research. In medicine, metal nanoparticles can be used in drug delivery systems, diagnostics, and therapeutic applications such as photothermal therapy and radiation therapy. Examples of metals used for nanoparticle synthesis include gold, silver, and iron.

Lectins are a type of proteins that bind specifically to carbohydrates and have been found in various plant and animal sources. They play important roles in biological recognition events, such as cell-cell adhesion, and can also be involved in the immune response. Some lectins can agglutinate certain types of cells or precipitate glycoproteins, while others may have a more direct effect on cellular processes. In some cases, lectins from plants can cause adverse effects in humans if ingested, such as digestive discomfort or allergic reactions.

Electrochemistry is a branch of chemistry that deals with the interconversion of electrical energy and chemical energy. It involves the study of chemical processes that cause electrons to move, resulting in the transfer of electrical charge, and the reverse processes by which electrical energy can be used to drive chemical reactions. This field encompasses various phenomena such as the generation of electricity from chemical sources (as in batteries), the electrolysis of substances, and corrosion. Electrochemical reactions are fundamental to many technologies, including energy storage and conversion, environmental protection, and medical diagnostics.

I believe there may be some confusion in your question. Gold is typically a chemical element with the symbol Au and atomic number 79. It is a dense, soft, malleable, and ductile metal. It is one of the least reactive chemical elements and is solid under standard conditions.

However, if you are referring to "Gold" in the context of medical terminology, it may refer to:

1. Gold salts: These are a group of compounds that contain gold and are used in medicine for their anti-inflammatory properties. They have been used in the treatment of rheumatoid arthritis, although they have largely been replaced by newer drugs with fewer side effects.
2. Gold implants: In some cases, a small amount of gold may be surgically implanted into the eye to treat conditions such as age-related macular degeneration or diabetic retinopathy. The gold helps to hold the retina in place and can improve vision in some patients.
3. Gold thread embedment: This is an alternative therapy used in traditional Chinese medicine, where gold threads are embedded into the skin or acupuncture points for therapeutic purposes. However, there is limited scientific evidence to support its effectiveness.

I hope this information helps! If you have any further questions, please let me know.

Concanavalin A (Con A) is a type of protein known as a lectin, which is found in the seeds of the plant Canavalia ensiformis, also known as jack bean. It is often used in laboratory settings as a tool to study various biological processes, such as cell division and the immune response, due to its ability to bind specifically to certain sugars on the surface of cells. Con A has been extensively studied for its potential applications in medicine, including as a possible treatment for cancer and viral infections. However, more research is needed before these potential uses can be realized.

Surface antigens are molecules found on the surface of cells that can be recognized by the immune system as being foreign or different from the host's own cells. Antigens are typically proteins or polysaccharides that are capable of stimulating an immune response, leading to the production of antibodies and activation of immune cells such as T-cells.

Surface antigens are important in the context of infectious diseases because they allow the immune system to identify and target infected cells for destruction. For example, viruses and bacteria often display surface antigens that are distinct from those found on host cells, allowing the immune system to recognize and attack them. In some cases, these surface antigens can also be used as targets for vaccines or other immunotherapies.

In addition to their role in infectious diseases, surface antigens are also important in the context of cancer. Tumor cells often display abnormal surface antigens that differ from those found on normal cells, allowing the immune system to potentially recognize and attack them. However, tumors can also develop mechanisms to evade the immune system, making it difficult to mount an effective response.

Overall, understanding the properties and behavior of surface antigens is crucial for developing effective immunotherapies and vaccines against infectious diseases and cancer.

Phosphatidylcholines (PtdCho) are a type of phospholipids that are essential components of cell membranes in living organisms. They are composed of a hydrophilic head group, which contains a choline moiety, and two hydrophobic fatty acid chains. Phosphatidylcholines are crucial for maintaining the structural integrity and function of cell membranes, and they also serve as important precursors for the synthesis of signaling molecules such as acetylcholine. They can be found in various tissues and biological fluids, including blood, and are abundant in foods such as soybeans, eggs, and meat. Phosphatidylcholines have been studied for their potential health benefits, including their role in maintaining healthy lipid metabolism and reducing the risk of cardiovascular disease.

X-ray diffraction (XRD) is not strictly a medical definition, but it is a technique commonly used in the field of medical research and diagnostics. XRD is a form of analytical spectroscopy that uses the phenomenon of X-ray diffraction to investigate the crystallographic structure of materials. When a beam of X-rays strikes a crystal, it is scattered in specific directions and with specific intensities that are determined by the arrangement of atoms within the crystal. By measuring these diffraction patterns, researchers can determine the crystal structures of various materials, including biological macromolecules such as proteins and viruses.

In the medical field, XRD is often used to study the structure of drugs and drug candidates, as well as to analyze the composition and structure of tissues and other biological samples. For example, XRD can be used to investigate the crystal structures of calcium phosphate minerals in bone tissue, which can provide insights into the mechanisms of bone formation and disease. Additionally, XRD is sometimes used in the development of new medical imaging techniques, such as phase-contrast X-ray imaging, which has the potential to improve the resolution and contrast of traditional X-ray images.

'Escherichia coli' (E. coli) is a type of gram-negative, facultatively anaerobic, rod-shaped bacterium that commonly inhabits the intestinal tract of humans and warm-blooded animals. It is a member of the family Enterobacteriaceae and one of the most well-studied prokaryotic model organisms in molecular biology.

While most E. coli strains are harmless and even beneficial to their hosts, some serotypes can cause various forms of gastrointestinal and extraintestinal illnesses in humans and animals. These pathogenic strains possess virulence factors that enable them to colonize and damage host tissues, leading to diseases such as diarrhea, urinary tract infections, pneumonia, and sepsis.

E. coli is a versatile organism with remarkable genetic diversity, which allows it to adapt to various environmental niches. It can be found in water, soil, food, and various man-made environments, making it an essential indicator of fecal contamination and a common cause of foodborne illnesses. The study of E. coli has contributed significantly to our understanding of fundamental biological processes, including DNA replication, gene regulation, and protein synthesis.

Bacterial proteins are a type of protein that are produced by bacteria as part of their structural or functional components. These proteins can be involved in various cellular processes, such as metabolism, DNA replication, transcription, and translation. They can also play a role in bacterial pathogenesis, helping the bacteria to evade the host's immune system, acquire nutrients, and multiply within the host.

Bacterial proteins can be classified into different categories based on their function, such as:

1. Enzymes: Proteins that catalyze chemical reactions in the bacterial cell.
2. Structural proteins: Proteins that provide structural support and maintain the shape of the bacterial cell.
3. Signaling proteins: Proteins that help bacteria to communicate with each other and coordinate their behavior.
4. Transport proteins: Proteins that facilitate the movement of molecules across the bacterial cell membrane.
5. Toxins: Proteins that are produced by pathogenic bacteria to damage host cells and promote infection.
6. Surface proteins: Proteins that are located on the surface of the bacterial cell and interact with the environment or host cells.

Understanding the structure and function of bacterial proteins is important for developing new antibiotics, vaccines, and other therapeutic strategies to combat bacterial infections.

Osteoblasts are specialized bone-forming cells that are derived from mesenchymal stem cells. They play a crucial role in the process of bone formation and remodeling. Osteoblasts synthesize, secrete, and mineralize the organic matrix of bones, which is mainly composed of type I collagen.

These cells have receptors for various hormones and growth factors that regulate their activity, such as parathyroid hormone, vitamin D, and transforming growth factor-beta. When osteoblasts are not actively producing bone matrix, they can become trapped within the matrix they produce, where they differentiate into osteocytes, which are mature bone cells that play a role in maintaining bone structure and responding to mechanical stress.

Abnormalities in osteoblast function can lead to various bone diseases, such as osteoporosis, osteogenesis imperfecta, and Paget's disease of bone.

Liposomes are artificially prepared, small, spherical vesicles composed of one or more lipid bilayers that enclose an aqueous compartment. They can encapsulate both hydrophilic and hydrophobic drugs, making them useful for drug delivery applications in the medical field. The lipid bilayer structure of liposomes is similar to that of biological membranes, which allows them to merge with and deliver their contents into cells. This property makes liposomes a valuable tool in delivering drugs directly to targeted sites within the body, improving drug efficacy while minimizing side effects.

Streptococcus mutans is a gram-positive, facultatively anaerobic, beta-hemolytic species of bacteria that's part of the normal microbiota of the oral cavity in humans. It's one of the primary etiological agents associated with dental caries, or tooth decay, due to its ability to produce large amounts of acid as a byproduct of sugar metabolism, which can lead to demineralization of tooth enamel and dentin. The bacterium can also adhere to tooth surfaces and form biofilms, further contributing to the development of dental caries.

Fungal spores are defined as the reproductive units of fungi that are produced by specialized structures called hyphae. These spores are typically single-celled and can exist in various shapes such as round, oval, or ellipsoidal. They are highly resistant to extreme environmental conditions like heat, cold, and dryness, which allows them to survive for long periods until they find a suitable environment to germinate and grow into a new fungal organism. Fungal spores can be found in the air, water, soil, and on various surfaces, making them easily dispersible and capable of causing infections in humans, animals, and plants.

Molecular models are three-dimensional representations of molecular structures that are used in the field of molecular biology and chemistry to visualize and understand the spatial arrangement of atoms and bonds within a molecule. These models can be physical or computer-generated and allow researchers to study the shape, size, and behavior of molecules, which is crucial for understanding their function and interactions with other molecules.

Physical molecular models are often made up of balls (representing atoms) connected by rods or sticks (representing bonds). These models can be constructed manually using materials such as plastic or wooden balls and rods, or they can be created using 3D printing technology.

Computer-generated molecular models, on the other hand, are created using specialized software that allows researchers to visualize and manipulate molecular structures in three dimensions. These models can be used to simulate molecular interactions, predict molecular behavior, and design new drugs or chemicals with specific properties. Overall, molecular models play a critical role in advancing our understanding of molecular structures and their functions.

Crystallization is a process in which a substance transitions from a liquid or dissolved state to a solid state, forming a crystal lattice. In the medical context, crystallization can refer to the formation of crystals within the body, which can occur under certain conditions such as changes in pH, temperature, or concentration of solutes. These crystals can deposit in various tissues and organs, leading to the formation of crystal-induced diseases or disorders.

For example, in patients with gout, uric acid crystals can accumulate in joints, causing inflammation, pain, and swelling. Similarly, in nephrolithiasis (kidney stones), minerals in the urine can crystallize and form stones that can obstruct the urinary tract. Crystallization can also occur in other medical contexts, such as in the formation of dental calculus or plaque, and in the development of cataracts in the eye.

Agglutination tests are laboratory diagnostic procedures used to detect the presence of antibodies or antigens in a sample, such as blood or serum. These tests work by observing the clumping (agglutination) of particles, like red blood cells or bacteriophages, coated with specific antigens or antibodies when mixed with a patient's sample.

In an agglutination test, the sample is typically combined with a reagent containing known antigens or antibodies on the surface of particles, such as latex beads, red blood cells, or bacteriophages. If the sample contains the corresponding antibodies or antigens, they will bind to the particles, forming visible clumps or agglutinates. The presence and strength of agglutination are then assessed visually or with automated equipment to determine the presence and quantity of the target antigen or antibody in the sample.

Agglutination tests are widely used in medical diagnostics for various applications, including:

1. Bacterial and viral infections: To identify specific bacterial or viral antigens in a patient's sample, such as group A Streptococcus, Legionella pneumophila, or HIV.
2. Blood typing: To determine the ABO blood group and Rh type of a donor or recipient before a blood transfusion or organ transplantation.
3. Autoimmune diseases: To detect autoantibodies in patients with suspected autoimmune disorders, such as rheumatoid arthritis, systemic lupus erythematosus, or Hashimoto's thyroiditis.
4. Allergies: To identify specific IgE antibodies in a patient's sample to determine allergic reactions to various substances, such as pollen, food, or venom.
5. Drug monitoring: To detect and quantify the presence of drug-induced antibodies, such as those developed in response to penicillin or hydralazine therapy.

Agglutination tests are simple, rapid, and cost-effective diagnostic tools that provide valuable information for clinical decision-making and patient management. However, they may have limitations, including potential cross-reactivity with other antigens, false-positive results due to rheumatoid factors or heterophile antibodies, and false-negative results due to the prozone effect or insufficient sensitivity. Therefore, it is essential to interpret agglutination test results in conjunction with clinical findings and other laboratory data.

In the context of medical definitions, 'carbon' is not typically used as a standalone term. Carbon is an element with the symbol C and atomic number 6, which is naturally abundant in the human body and the environment. It is a crucial component of all living organisms, forming the basis of organic compounds, such as proteins, carbohydrates, lipids, and nucleic acids (DNA and RNA).

Carbon forms strong covalent bonds with various elements, allowing for the creation of complex molecules that are essential to life. In this sense, carbon is a fundamental building block of life on Earth. However, it does not have a specific medical definition as an isolated term.

Cell shape refers to the physical form or configuration of a cell, which is determined by the cytoskeleton (the internal framework of the cell) and the extracellular matrix (the external environment surrounding the cell). The shape of a cell can vary widely depending on its type and function. For example, some cells are spherical, such as red blood cells, while others are elongated or irregularly shaped. Changes in cell shape can be indicative of various physiological or pathological processes, including development, differentiation, migration, and disease.

Teichoic acids are complex polymers of glycerol or ribitol linked by phosphate groups, found in the cell wall of gram-positive bacteria. They play a crucial role in the bacterial cell's defense against hostile environments and can also contribute to virulence by helping the bacteria evade the host's immune system. Teichoic acids can be either linked to peptidoglycan (wall teichoic acids) or to membrane lipids (lipoteichoic acids). They can vary in structure and composition among different bacterial species, which can have implications for the design of antibiotics and other therapeutics.

Molecular sequence data refers to the specific arrangement of molecules, most commonly nucleotides in DNA or RNA, or amino acids in proteins, that make up a biological macromolecule. This data is generated through laboratory techniques such as sequencing, and provides information about the exact order of the constituent molecules. This data is crucial in various fields of biology, including genetics, evolution, and molecular biology, allowing for comparisons between different organisms, identification of genetic variations, and studies of gene function and regulation.

An amino acid sequence is the specific order of amino acids in a protein or peptide molecule, formed by the linking of the amino group (-NH2) of one amino acid to the carboxyl group (-COOH) of another amino acid through a peptide bond. The sequence is determined by the genetic code and is unique to each type of protein or peptide. It plays a crucial role in determining the three-dimensional structure and function of proteins.

Bacterial polysaccharides are complex carbohydrates that consist of long chains of sugar molecules (monosaccharides) linked together by glycosidic bonds. They are produced and used by bacteria for various purposes such as:

1. Structural components: Bacterial polysaccharides, such as peptidoglycan and lipopolysaccharide (LPS), play a crucial role in maintaining the structural integrity of bacterial cells. Peptidoglycan is a major component of the bacterial cell wall, while LPS forms the outer layer of the outer membrane in gram-negative bacteria.
2. Nutrient storage: Some bacteria synthesize and store polysaccharides as an energy reserve, similar to how plants store starch. These polysaccharides can be broken down and utilized by the bacterium when needed.
3. Virulence factors: Bacterial polysaccharides can also function as virulence factors, contributing to the pathogenesis of bacterial infections. For example, certain bacteria produce capsular polysaccharides (CPS) that surround and protect the bacterial cells from host immune defenses, allowing them to evade phagocytosis and persist within the host.
4. Adhesins: Some polysaccharides act as adhesins, facilitating the attachment of bacteria to surfaces or host cells. This is important for biofilm formation, which helps bacteria resist environmental stresses and antibiotic treatments.
5. Antigenic properties: Bacterial polysaccharides can be highly antigenic, eliciting an immune response in the host. The antigenicity of these molecules can vary between different bacterial species or even strains within a species, making them useful as targets for vaccines and diagnostic tests.

In summary, bacterial polysaccharides are complex carbohydrates that serve various functions in bacteria, including structural support, nutrient storage, virulence factor production, adhesion, and antigenicity.

Differential scanning calorimetry (DSC) is a thermoanalytical technique used to measure the difference in the amount of heat required to increase the temperature of a sample and a reference as a function of temperature. It is commonly used to study phase transitions, such as melting, crystallization, and glass transition, as well as chemical reactions, in a wide range of materials, including polymers, pharmaceuticals, and biological samples.

In DSC, the sample and reference are placed in separate pans and heated at a constant rate. The heat flow required to maintain this heating rate is continuously measured for both the sample and the reference. As the temperature of the sample changes during a phase transition or chemical reaction, the heat flow required to maintain the same heating rate will change relative to the reference. This allows for the measurement of the enthalpy change (ΔH) associated with the transition or reaction.

Differential scanning calorimetry is a powerful tool in materials science and research as it can provide information about the thermal behavior, stability, and composition of materials. It can also be used to study the kinetics of reactions and phase transitions, making it useful for optimizing processing conditions and developing new materials.

In medical terms, pressure is defined as the force applied per unit area on an object or body surface. It is often measured in millimeters of mercury (mmHg) in clinical settings. For example, blood pressure is the force exerted by circulating blood on the walls of the arteries and is recorded as two numbers: systolic pressure (when the heart beats and pushes blood out) and diastolic pressure (when the heart rests between beats).

Pressure can also refer to the pressure exerted on a wound or incision to help control bleeding, or the pressure inside the skull or spinal canal. High or low pressure in different body systems can indicate various medical conditions and require appropriate treatment.

Viscosity is a physical property of a fluid that describes its resistance to flow. In medical terms, viscosity is often discussed in relation to bodily fluids such as blood or synovial fluid (found in joints). The unit of measurement for viscosity is the poise, although it is more commonly expressed in millipascals-second (mPa.s) in SI units. Highly viscous fluids flow more slowly than less viscous fluids. Changes in the viscosity of bodily fluids can have significant implications for health and disease; for example, increased blood viscosity has been associated with cardiovascular diseases, while decreased synovial fluid viscosity can contribute to joint pain and inflammation in conditions like osteoarthritis.

Drug delivery systems (DDS) refer to techniques or technologies that are designed to improve the administration of a pharmaceutical compound in terms of its efficiency, safety, and efficacy. A DDS can modify the drug release profile, target the drug to specific cells or tissues, protect the drug from degradation, and reduce side effects.

The goal of a DDS is to optimize the bioavailability of a drug, which is the amount of the drug that reaches the systemic circulation and is available at the site of action. This can be achieved through various approaches, such as encapsulating the drug in a nanoparticle or attaching it to a biomolecule that targets specific cells or tissues.

Some examples of DDS include:

1. Controlled release systems: These systems are designed to release the drug at a controlled rate over an extended period, reducing the frequency of dosing and improving patient compliance.
2. Targeted delivery systems: These systems use biomolecules such as antibodies or ligands to target the drug to specific cells or tissues, increasing its efficacy and reducing side effects.
3. Nanoparticle-based delivery systems: These systems use nanoparticles made of polymers, lipids, or inorganic materials to encapsulate the drug and protect it from degradation, improve its solubility, and target it to specific cells or tissues.
4. Biodegradable implants: These are small devices that can be implanted under the skin or into body cavities to deliver drugs over an extended period. They can be made of biodegradable materials that gradually break down and release the drug.
5. Inhalation delivery systems: These systems use inhalers or nebulizers to deliver drugs directly to the lungs, bypassing the digestive system and improving bioavailability.

Overall, DDS play a critical role in modern pharmaceutical research and development, enabling the creation of new drugs with improved efficacy, safety, and patient compliance.

I believe there may be some confusion in your question. "Rabbits" is a common name used to refer to the Lagomorpha species, particularly members of the family Leporidae. They are small mammals known for their long ears, strong legs, and quick reproduction.

However, if you're referring to "rabbits" in a medical context, there is a term called "rabbit syndrome," which is a rare movement disorder characterized by repetitive, involuntary movements of the fingers, resembling those of a rabbit chewing. It is also known as "finger-chewing chorea." This condition is usually associated with certain medications, particularly antipsychotics, and typically resolves when the medication is stopped or adjusted.

Virulence, in the context of medicine and microbiology, refers to the degree or severity of damage or harm that a pathogen (like a bacterium, virus, fungus, or parasite) can cause to its host. It is often associated with the ability of the pathogen to invade and damage host tissues, evade or suppress the host's immune response, replicate within the host, and spread between hosts.

Virulence factors are the specific components or mechanisms that contribute to a pathogen's virulence, such as toxins, enzymes, adhesins, and capsules. These factors enable the pathogen to establish an infection, cause tissue damage, and facilitate its transmission between hosts. The overall virulence of a pathogen can be influenced by various factors, including host susceptibility, environmental conditions, and the specific strain or species of the pathogen.

Phospholipids are a major class of lipids that consist of a hydrophilic (water-attracting) head and two hydrophobic (water-repelling) tails. The head is composed of a phosphate group, which is often bound to an organic molecule such as choline, ethanolamine, serine or inositol. The tails are made up of two fatty acid chains.

Phospholipids are a key component of cell membranes and play a crucial role in maintaining the structural integrity and function of the cell. They form a lipid bilayer, with the hydrophilic heads facing outwards and the hydrophobic tails facing inwards, creating a barrier that separates the interior of the cell from the outside environment.

Phospholipids are also involved in various cellular processes such as signal transduction, intracellular trafficking, and protein function regulation. Additionally, they serve as emulsifiers in the digestive system, helping to break down fats in the diet.

Cell aggregation is the process by which individual cells come together and adhere to each other to form a group or cluster. This phenomenon can occur naturally during embryonic development, tissue repair, and wound healing, as well as in the formation of multicellular organisms such as slime molds. In some cases, cell aggregation may also be induced in the laboratory setting through the use of various techniques, including the use of cell culture surfaces that promote cell-to-cell adhesion or the addition of factors that stimulate the expression of adhesion molecules on the cell surface.

Cell aggregation can be influenced by a variety of factors, including the type and properties of the cells involved, as well as environmental conditions such as pH, temperature, and nutrient availability. The ability of cells to aggregate is often mediated by the presence of adhesion molecules on the cell surface, such as cadherins, integrins, and immunoglobulin-like cell adhesion molecules (Ig-CAMs). These molecules interact with each other and with extracellular matrix components to promote cell-to-cell adhesion and maintain the stability of the aggregate.

In some contexts, abnormal or excessive cell aggregation can contribute to the development of diseases such as cancer, fibrosis, and inflammatory disorders. For example, the aggregation of cancer cells can facilitate their invasion and metastasis, while the accumulation of fibrotic cells in tissues can lead to organ dysfunction and failure. Understanding the mechanisms that regulate cell aggregation is therefore an important area of research with potential implications for the development of new therapies and treatments for a variety of diseases.

Lactic acid, also known as 2-hydroxypropanoic acid, is a chemical compound that plays a significant role in various biological processes. In the context of medicine and biochemistry, lactic acid is primarily discussed in relation to muscle metabolism and cellular energy production. Here's a medical definition for lactic acid:

Lactic acid (LA): A carboxylic acid with the molecular formula C3H6O3 that plays a crucial role in anaerobic respiration, particularly during strenuous exercise or conditions of reduced oxygen availability. It is formed through the conversion of pyruvate, catalyzed by the enzyme lactate dehydrogenase (LDH), when there is insufficient oxygen to complete the final step of cellular respiration in the Krebs cycle. The accumulation of lactic acid can lead to acidosis and muscle fatigue. Additionally, lactic acid serves as a vital intermediary in various metabolic pathways and is involved in the production of glucose through gluconeogenesis in the liver.

Protein conformation refers to the specific three-dimensional shape that a protein molecule assumes due to the spatial arrangement of its constituent amino acid residues and their associated chemical groups. This complex structure is determined by several factors, including covalent bonds (disulfide bridges), hydrogen bonds, van der Waals forces, and ionic bonds, which help stabilize the protein's unique conformation.

Protein conformations can be broadly classified into two categories: primary, secondary, tertiary, and quaternary structures. The primary structure represents the linear sequence of amino acids in a polypeptide chain. The secondary structure arises from local interactions between adjacent amino acid residues, leading to the formation of recurring motifs such as α-helices and β-sheets. Tertiary structure refers to the overall three-dimensional folding pattern of a single polypeptide chain, while quaternary structure describes the spatial arrangement of multiple folded polypeptide chains (subunits) that interact to form a functional protein complex.

Understanding protein conformation is crucial for elucidating protein function, as the specific three-dimensional shape of a protein directly influences its ability to interact with other molecules, such as ligands, nucleic acids, or other proteins. Any alterations in protein conformation due to genetic mutations, environmental factors, or chemical modifications can lead to loss of function, misfolding, aggregation, and disease states like neurodegenerative disorders and cancer.

In the context of medical terminology, "solutions" refers to a homogeneous mixture of two or more substances, in which one substance (the solute) is uniformly distributed within another substance (the solvent). The solvent is typically the greater component of the solution and is capable of dissolving the solute.

Solutions can be classified based on the physical state of the solvent and solute. For instance, a solution in which both the solvent and solute are liquids is called a liquid solution or simply a solution. A solid solution is one where the solvent is a solid and the solute is either a gas, liquid, or solid. Similarly, a gas solution refers to a mixture where the solvent is a gas and the solute can be a gas, liquid, or solid.

In medical applications, solutions are often used as vehicles for administering medications, such as intravenous (IV) fluids, oral rehydration solutions, eye drops, and topical creams or ointments. The composition of these solutions is carefully controlled to ensure the appropriate concentration and delivery of the active ingredients.

Solvents, in a medical context, are substances that are capable of dissolving or dispersing other materials, often used in the preparation of medications and solutions. They are commonly organic chemicals that can liquefy various substances, making it possible to administer them in different forms, such as oral solutions, topical creams, or injectable drugs.

However, it is essential to recognize that solvents may pose health risks if mishandled or misused, particularly when they contain volatile organic compounds (VOCs). Prolonged exposure to these VOCs can lead to adverse health effects, including respiratory issues, neurological damage, and even cancer. Therefore, it is crucial to handle solvents with care and follow safety guidelines to minimize potential health hazards.

Streptococcus is a genus of Gram-positive, spherical bacteria that typically form pairs or chains when clustered together. These bacteria are facultative anaerobes, meaning they can grow in the presence or absence of oxygen. They are non-motile and do not produce spores.

Streptococcus species are commonly found on the skin and mucous membranes of humans and animals. Some strains are part of the normal flora of the body, while others can cause a variety of infections, ranging from mild skin infections to severe and life-threatening diseases such as sepsis, meningitis, and toxic shock syndrome.

The pathogenicity of Streptococcus species depends on various virulence factors, including the production of enzymes and toxins that damage tissues and evade the host's immune response. One of the most well-known Streptococcus species is Streptococcus pyogenes, also known as group A streptococcus (GAS), which is responsible for a wide range of clinical manifestations, including pharyngitis (strep throat), impetigo, cellulitis, necrotizing fasciitis, and rheumatic fever.

It's important to note that the classification of Streptococcus species has evolved over time, with many former members now classified as different genera within the family Streptococcaceae. The current classification system is based on a combination of phenotypic characteristics (such as hemolysis patterns and sugar fermentation) and genotypic methods (such as 16S rRNA sequencing and multilocus sequence typing).

A cell line is a culture of cells that are grown in a laboratory for use in research. These cells are usually taken from a single cell or group of cells, and they are able to divide and grow continuously in the lab. Cell lines can come from many different sources, including animals, plants, and humans. They are often used in scientific research to study cellular processes, disease mechanisms, and to test new drugs or treatments. Some common types of human cell lines include HeLa cells (which come from a cancer patient named Henrietta Lacks), HEK293 cells (which come from embryonic kidney cells), and HUVEC cells (which come from umbilical vein endothelial cells). It is important to note that cell lines are not the same as primary cells, which are cells that are taken directly from a living organism and have not been grown in the lab.

A mutation is a permanent change in the DNA sequence of an organism's genome. Mutations can occur spontaneously or be caused by environmental factors such as exposure to radiation, chemicals, or viruses. They may have various effects on the organism, ranging from benign to harmful, depending on where they occur and whether they alter the function of essential proteins. In some cases, mutations can increase an individual's susceptibility to certain diseases or disorders, while in others, they may confer a survival advantage. Mutations are the driving force behind evolution, as they introduce new genetic variability into populations, which can then be acted upon by natural selection.

"Cattle" is a term used in the agricultural and veterinary fields to refer to domesticated animals of the genus *Bos*, primarily *Bos taurus* (European cattle) and *Bos indicus* (Zebu). These animals are often raised for meat, milk, leather, and labor. They are also known as bovines or cows (for females), bulls (intact males), and steers/bullocks (castrated males). However, in a strict medical definition, "cattle" does not apply to humans or other animals.

Bacterial outer membrane proteins (OMPs) are a type of protein found in the outer membrane of gram-negative bacteria. The outer membrane is a unique characteristic of gram-negative bacteria, and it serves as a barrier that helps protect the bacterium from hostile environments. OMPs play a crucial role in maintaining the structural integrity and selective permeability of the outer membrane. They are involved in various functions such as nutrient uptake, transport, adhesion, and virulence factor secretion.

OMPs are typically composed of beta-barrel structures that span the bacterial outer membrane. These proteins can be classified into several groups based on their size, function, and structure. Some of the well-known OMP families include porins, autotransporters, and two-partner secretion systems.

Porins are the most abundant type of OMPs and form water-filled channels that allow the passive diffusion of small molecules, ions, and nutrients across the outer membrane. Autotransporters are a diverse group of OMPs that play a role in bacterial pathogenesis by secreting virulence factors or acting as adhesins. Two-partner secretion systems involve the cooperation between two proteins to transport effector molecules across the outer membrane.

Understanding the structure and function of bacterial OMPs is essential for developing new antibiotics and therapies that target gram-negative bacteria, which are often resistant to conventional treatments.

"Cells, cultured" is a medical term that refers to cells that have been removed from an organism and grown in controlled laboratory conditions outside of the body. This process is called cell culture and it allows scientists to study cells in a more controlled and accessible environment than they would have inside the body. Cultured cells can be derived from a variety of sources, including tissues, organs, or fluids from humans, animals, or cell lines that have been previously established in the laboratory.

Cell culture involves several steps, including isolation of the cells from the tissue, purification and characterization of the cells, and maintenance of the cells in appropriate growth conditions. The cells are typically grown in specialized media that contain nutrients, growth factors, and other components necessary for their survival and proliferation. Cultured cells can be used for a variety of purposes, including basic research, drug development and testing, and production of biological products such as vaccines and gene therapies.

It is important to note that cultured cells may behave differently than they do in the body, and results obtained from cell culture studies may not always translate directly to human physiology or disease. Therefore, it is essential to validate findings from cell culture experiments using additional models and ultimately in clinical trials involving human subjects.

Protein binding, in the context of medical and biological sciences, refers to the interaction between a protein and another molecule (known as the ligand) that results in a stable complex. This process is often reversible and can be influenced by various factors such as pH, temperature, and concentration of the involved molecules.

In clinical chemistry, protein binding is particularly important when it comes to drugs, as many of them bind to proteins (especially albumin) in the bloodstream. The degree of protein binding can affect a drug's distribution, metabolism, and excretion, which in turn influence its therapeutic effectiveness and potential side effects.

Protein-bound drugs may be less available for interaction with their target tissues, as only the unbound or "free" fraction of the drug is active. Therefore, understanding protein binding can help optimize dosing regimens and minimize adverse reactions.

Membrane proteins are a type of protein that are embedded in the lipid bilayer of biological membranes, such as the plasma membrane of cells or the inner membrane of mitochondria. These proteins play crucial roles in various cellular processes, including:

1. Cell-cell recognition and signaling
2. Transport of molecules across the membrane (selective permeability)
3. Enzymatic reactions at the membrane surface
4. Energy transduction and conversion
5. Mechanosensation and signal transduction

Membrane proteins can be classified into two main categories: integral membrane proteins, which are permanently associated with the lipid bilayer, and peripheral membrane proteins, which are temporarily or loosely attached to the membrane surface. Integral membrane proteins can further be divided into three subcategories based on their topology:

1. Transmembrane proteins, which span the entire width of the lipid bilayer with one or more alpha-helices or beta-barrels.
2. Lipid-anchored proteins, which are covalently attached to lipids in the membrane via a glycosylphosphatidylinositol (GPI) anchor or other lipid modifications.
3. Monotopic proteins, which are partially embedded in the membrane and have one or more domains exposed to either side of the bilayer.

Membrane proteins are essential for maintaining cellular homeostasis and are targets for various therapeutic interventions, including drug development and gene therapy. However, their structural complexity and hydrophobicity make them challenging to study using traditional biochemical methods, requiring specialized techniques such as X-ray crystallography, nuclear magnetic resonance (NMR) spectroscopy, and single-particle cryo-electron microscopy (cryo-EM).

In the context of medical and biological sciences, a "binding site" refers to a specific location on a protein, molecule, or cell where another molecule can attach or bind. This binding interaction can lead to various functional changes in the original protein or molecule. The other molecule that binds to the binding site is often referred to as a ligand, which can be a small molecule, ion, or even another protein.

The binding between a ligand and its target binding site can be specific and selective, meaning that only certain ligands can bind to particular binding sites with high affinity. This specificity plays a crucial role in various biological processes, such as signal transduction, enzyme catalysis, or drug action.

In the case of drug development, understanding the location and properties of binding sites on target proteins is essential for designing drugs that can selectively bind to these sites and modulate protein function. This knowledge can help create more effective and safer therapeutic options for various diseases.

Molecular conformation, also known as spatial arrangement or configuration, refers to the specific three-dimensional shape and orientation of atoms that make up a molecule. It describes the precise manner in which bonds between atoms are arranged around a molecular framework, taking into account factors such as bond lengths, bond angles, and torsional angles.

Conformational isomers, or conformers, are different spatial arrangements of the same molecule that can interconvert without breaking chemical bonds. These isomers may have varying energies, stability, and reactivity, which can significantly impact a molecule's biological activity and function. Understanding molecular conformation is crucial in fields such as drug design, where small changes in conformation can lead to substantial differences in how a drug interacts with its target.

Lipopolysaccharides (LPS) are large molecules found in the outer membrane of Gram-negative bacteria. They consist of a hydrophilic polysaccharide called the O-antigen, a core oligosaccharide, and a lipid portion known as Lipid A. The Lipid A component is responsible for the endotoxic activity of LPS, which can trigger a powerful immune response in animals, including humans. This response can lead to symptoms such as fever, inflammation, and septic shock, especially when large amounts of LPS are introduced into the bloodstream.

In the context of medicine and pharmacology, "kinetics" refers to the study of how a drug moves throughout the body, including its absorption, distribution, metabolism, and excretion (often abbreviated as ADME). This field is called "pharmacokinetics."

1. Absorption: This is the process of a drug moving from its site of administration into the bloodstream. Factors such as the route of administration (e.g., oral, intravenous, etc.), formulation, and individual physiological differences can affect absorption.

2. Distribution: Once a drug is in the bloodstream, it gets distributed throughout the body to various tissues and organs. This process is influenced by factors like blood flow, protein binding, and lipid solubility of the drug.

3. Metabolism: Drugs are often chemically modified in the body, typically in the liver, through processes known as metabolism. These changes can lead to the formation of active or inactive metabolites, which may then be further distributed, excreted, or undergo additional metabolic transformations.

4. Excretion: This is the process by which drugs and their metabolites are eliminated from the body, primarily through the kidneys (urine) and the liver (bile).

Understanding the kinetics of a drug is crucial for determining its optimal dosing regimen, potential interactions with other medications or foods, and any necessary adjustments for special populations like pediatric or geriatric patients, or those with impaired renal or hepatic function.

I'm sorry for any confusion, but "thermodynamics" is not a term that has a specific medical definition. It is a branch of physics that deals with the relationships between heat and other forms of energy. However, the principles of thermodynamics can be applied to biological systems, including those in the human body, such as in the study of metabolism or muscle function. But in a medical context, "thermodynamics" would not be a term used independently as a diagnosis, treatment, or any medical condition.

Photic stimulation is a medical term that refers to the exposure of the eyes to light, specifically repetitive pulses of light, which is used as a method in various research and clinical settings. In neuroscience, it's often used in studies related to vision, circadian rhythms, and brain function.

In a clinical context, photic stimulation is sometimes used in the diagnosis of certain medical conditions such as seizure disorders (like epilepsy). By observing the response of the brain to this light stimulus, doctors can gain valuable insights into the functioning of the brain and the presence of any neurological disorders.

However, it's important to note that photic stimulation should be conducted under the supervision of a trained healthcare professional, as improper use can potentially trigger seizures in individuals who are susceptible to them.

Tissue engineering is a branch of biomedical engineering that combines the principles of engineering, materials science, and biological sciences to develop functional substitutes for damaged or diseased tissues and organs. It involves the creation of living, three-dimensional structures that can restore, maintain, or improve tissue function. This is typically accomplished through the use of cells, scaffolds (biodegradable matrices), and biologically active molecules. The goal of tissue engineering is to develop biological substitutes that can ultimately restore normal function and structure in damaged tissues or organs.

Fluorescence spectrometry is a type of analytical technique used to investigate the fluorescent properties of a sample. It involves the measurement of the intensity of light emitted by a substance when it absorbs light at a specific wavelength and then re-emits it at a longer wavelength. This process, known as fluorescence, occurs because the absorbed energy excites electrons in the molecules of the substance to higher energy states, and when these electrons return to their ground state, they release the excess energy as light.

Fluorescence spectrometry typically measures the emission spectrum of a sample, which is a plot of the intensity of emitted light versus the wavelength of emission. This technique can be used to identify and quantify the presence of specific fluorescent molecules in a sample, as well as to study their photophysical properties.

Fluorescence spectrometry has many applications in fields such as biochemistry, environmental science, and materials science. For example, it can be used to detect and measure the concentration of pollutants in water samples, to analyze the composition of complex biological mixtures, or to study the properties of fluorescent nanomaterials.

Secondary protein structure refers to the local spatial arrangement of amino acid chains in a protein, typically described as regular repeating patterns held together by hydrogen bonds. The two most common types of secondary structures are the alpha-helix (α-helix) and the beta-pleated sheet (β-sheet). In an α-helix, the polypeptide chain twists around itself in a helical shape, with each backbone atom forming a hydrogen bond with the fourth amino acid residue along the chain. This forms a rigid rod-like structure that is resistant to bending or twisting forces. In β-sheets, adjacent segments of the polypeptide chain run parallel or antiparallel to each other and are connected by hydrogen bonds, forming a pleated sheet-like arrangement. These secondary structures provide the foundation for the formation of tertiary and quaternary protein structures, which determine the overall three-dimensional shape and function of the protein.

Macromolecular substances, also known as macromolecules, are large, complex molecules made up of repeating subunits called monomers. These substances are formed through polymerization, a process in which many small molecules combine to form a larger one. Macromolecular substances can be naturally occurring, such as proteins, DNA, and carbohydrates, or synthetic, such as plastics and synthetic fibers.

In the context of medicine, macromolecular substances are often used in the development of drugs and medical devices. For example, some drugs are designed to bind to specific macromolecules in the body, such as proteins or DNA, in order to alter their function and produce a therapeutic effect. Additionally, macromolecular substances may be used in the creation of medical implants, such as artificial joints and heart valves, due to their strength and durability.

It is important for healthcare professionals to have an understanding of macromolecular substances and how they function in the body, as this knowledge can inform the development and use of medical treatments.

Fluorescence microscopy is a type of microscopy that uses fluorescent dyes or proteins to highlight and visualize specific components within a sample. In this technique, the sample is illuminated with high-energy light, typically ultraviolet (UV) or blue light, which excites the fluorescent molecules causing them to emit lower-energy, longer-wavelength light, usually visible light in the form of various colors. This emitted light is then collected by the microscope and detected to produce an image.

Fluorescence microscopy has several advantages over traditional brightfield microscopy, including the ability to visualize specific structures or molecules within a complex sample, increased sensitivity, and the potential for quantitative analysis. It is widely used in various fields of biology and medicine, such as cell biology, neuroscience, and pathology, to study the structure, function, and interactions of cells and proteins.

There are several types of fluorescence microscopy techniques, including widefield fluorescence microscopy, confocal microscopy, two-photon microscopy, and total internal reflection fluorescence (TIRF) microscopy, each with its own strengths and limitations. These techniques can provide valuable insights into the behavior of cells and proteins in health and disease.

Fluorescent dyes are substances that emit light upon excitation by absorbing light of a shorter wavelength. In a medical context, these dyes are often used in various diagnostic tests and procedures to highlight or mark certain structures or substances within the body. For example, fluorescent dyes may be used in imaging techniques such as fluorescence microscopy or fluorescence angiography to help visualize cells, tissues, or blood vessels. These dyes can also be used in flow cytometry to identify and sort specific types of cells. The choice of fluorescent dye depends on the specific application and the desired properties, such as excitation and emission spectra, quantum yield, and photostability.

Magnetic Resonance Spectroscopy (MRS) is a non-invasive diagnostic technique that provides information about the biochemical composition of tissues, including their metabolic state. It is often used in conjunction with Magnetic Resonance Imaging (MRI) to analyze various metabolites within body tissues, such as the brain, heart, liver, and muscles.

During MRS, a strong magnetic field, radio waves, and a computer are used to produce detailed images and data about the concentration of specific metabolites in the targeted tissue or organ. This technique can help detect abnormalities related to energy metabolism, neurotransmitter levels, pH balance, and other biochemical processes, which can be useful for diagnosing and monitoring various medical conditions, including cancer, neurological disorders, and metabolic diseases.

There are different types of MRS, such as Proton (^1^H) MRS, Phosphorus-31 (^31^P) MRS, and Carbon-13 (^13^C) MRS, each focusing on specific elements or metabolites within the body. The choice of MRS technique depends on the clinical question being addressed and the type of information needed for diagnosis or monitoring purposes.

Peptides are short chains of amino acid residues linked by covalent bonds, known as peptide bonds. They are formed when two or more amino acids are joined together through a condensation reaction, which results in the elimination of a water molecule and the formation of an amide bond between the carboxyl group of one amino acid and the amino group of another.

Peptides can vary in length from two to about fifty amino acids, and they are often classified based on their size. For example, dipeptides contain two amino acids, tripeptides contain three, and so on. Oligopeptides typically contain up to ten amino acids, while polypeptides can contain dozens or even hundreds of amino acids.

Peptides play many important roles in the body, including serving as hormones, neurotransmitters, enzymes, and antibiotics. They are also used in medical research and therapeutic applications, such as drug delivery and tissue engineering.

Erythrocytes, also known as red blood cells (RBCs), are the most common type of blood cell in circulating blood in mammals. They are responsible for transporting oxygen from the lungs to the body's tissues and carbon dioxide from the tissues to the lungs.

Erythrocytes are formed in the bone marrow and have a biconcave shape, which allows them to fold and bend easily as they pass through narrow blood vessels. They do not have a nucleus or mitochondria, which makes them more flexible but also limits their ability to reproduce or repair themselves.

In humans, erythrocytes are typically disc-shaped and measure about 7 micrometers in diameter. They contain the protein hemoglobin, which binds to oxygen and gives blood its red color. The lifespan of an erythrocyte is approximately 120 days, after which it is broken down in the liver and spleen.

Abnormalities in erythrocyte count or function can lead to various medical conditions, such as anemia, polycythemia, and sickle cell disease.

In a medical context, "hot temperature" is not a standard medical term with a specific definition. However, it is often used in relation to fever, which is a common symptom of illness. A fever is typically defined as a body temperature that is higher than normal, usually above 38°C (100.4°F) for adults and above 37.5-38°C (99.5-101.3°F) for children, depending on the source.

Therefore, when a medical professional talks about "hot temperature," they may be referring to a body temperature that is higher than normal due to fever or other causes. It's important to note that a high environmental temperature can also contribute to an elevated body temperature, so it's essential to consider both the body temperature and the environmental temperature when assessing a patient's condition.

Molecular structure, in the context of biochemistry and molecular biology, refers to the arrangement and organization of atoms and chemical bonds within a molecule. It describes the three-dimensional layout of the constituent elements, including their spatial relationships, bond lengths, and angles. Understanding molecular structure is crucial for elucidating the functions and reactivities of biological macromolecules such as proteins, nucleic acids, lipids, and carbohydrates. Various experimental techniques, like X-ray crystallography, nuclear magnetic resonance (NMR) spectroscopy, and cryo-electron microscopy (cryo-EM), are employed to determine molecular structures at atomic resolution, providing valuable insights into their biological roles and potential therapeutic targets.

Proteins are complex, large molecules that play critical roles in the body's functions. They are made up of amino acids, which are organic compounds that are the building blocks of proteins. Proteins are required for the structure, function, and regulation of the body's tissues and organs. They are essential for the growth, repair, and maintenance of body tissues, and they play a crucial role in many biological processes, including metabolism, immune response, and cellular signaling. Proteins can be classified into different types based on their structure and function, such as enzymes, hormones, antibodies, and structural proteins. They are found in various foods, especially animal-derived products like meat, dairy, and eggs, as well as plant-based sources like beans, nuts, and grains.

Electrophoresis, polyacrylamide gel (EPG) is a laboratory technique used to separate and analyze complex mixtures of proteins or nucleic acids (DNA or RNA) based on their size and electrical charge. This technique utilizes a matrix made of cross-linked polyacrylamide, a type of gel, which provides a stable and uniform environment for the separation of molecules.

In this process:

1. The polyacrylamide gel is prepared by mixing acrylamide monomers with a cross-linking agent (bis-acrylamide) and a catalyst (ammonium persulfate) in the presence of a buffer solution.
2. The gel is then poured into a mold and allowed to polymerize, forming a solid matrix with uniform pore sizes that depend on the concentration of acrylamide used. Higher concentrations result in smaller pores, providing better resolution for separating smaller molecules.
3. Once the gel has set, it is placed in an electrophoresis apparatus containing a buffer solution. Samples containing the mixture of proteins or nucleic acids are loaded into wells on the top of the gel.
4. An electric field is applied across the gel, causing the negatively charged molecules to migrate towards the positive electrode (anode) while positively charged molecules move toward the negative electrode (cathode). The rate of migration depends on the size, charge, and shape of the molecules.
5. Smaller molecules move faster through the gel matrix and will migrate farther from the origin compared to larger molecules, resulting in separation based on size. Proteins and nucleic acids can be selectively stained after electrophoresis to visualize the separated bands.

EPG is widely used in various research fields, including molecular biology, genetics, proteomics, and forensic science, for applications such as protein characterization, DNA fragment analysis, cloning, mutation detection, and quality control of nucleic acid or protein samples.

A chemical model is a simplified representation or description of a chemical system, based on the laws of chemistry and physics. It is used to explain and predict the behavior of chemicals and chemical reactions. Chemical models can take many forms, including mathematical equations, diagrams, and computer simulations. They are often used in research, education, and industry to understand complex chemical processes and develop new products and technologies.

For example, a chemical model might be used to describe the way that atoms and molecules interact in a particular reaction, or to predict the properties of a new material. Chemical models can also be used to study the behavior of chemicals at the molecular level, such as how they bind to each other or how they are affected by changes in temperature or pressure.

It is important to note that chemical models are simplifications of reality and may not always accurately represent every aspect of a chemical system. They should be used with caution and validated against experimental data whenever possible.

Lipids are a broad group of organic compounds that are insoluble in water but soluble in nonpolar organic solvents. They include fats, waxes, sterols, fat-soluble vitamins (such as vitamins A, D, E, and K), monoglycerides, diglycerides, triglycerides, and phospholipids. Lipids serve many important functions in the body, including energy storage, acting as structural components of cell membranes, and serving as signaling molecules. High levels of certain lipids, particularly cholesterol and triglycerides, in the blood are associated with an increased risk of cardiovascular disease.

A plasmid is a small, circular, double-stranded DNA molecule that is separate from the chromosomal DNA of a bacterium or other organism. Plasmids are typically not essential for the survival of the organism, but they can confer beneficial traits such as antibiotic resistance or the ability to degrade certain types of pollutants.

Plasmids are capable of replicating independently of the chromosomal DNA and can be transferred between bacteria through a process called conjugation. They often contain genes that provide resistance to antibiotics, heavy metals, and other environmental stressors. Plasmids have also been engineered for use in molecular biology as cloning vectors, allowing scientists to replicate and manipulate specific DNA sequences.

Plasmids are important tools in genetic engineering and biotechnology because they can be easily manipulated and transferred between organisms. They have been used to produce vaccines, diagnostic tests, and genetically modified organisms (GMOs) for various applications, including agriculture, medicine, and industry.

An example of a polar surface is the rocksalt (111) surface. In general, a polar surface is less stable than a nonpolar surface ... The surface acidity and basicity of the oxide depends on the crystal structure and surface orientation. The surfaces of ... Examples of nonpolar surfaces include the rocksalt (100) surface, the rutile (100), (110) and (001) surfaces and the pervoskite ... the surface will be dipoleless and is considered a nonpolar surface. If the structures are different, the surface will have a ...
A heat flow and physical properties package for the surface of Mercury. Tilman Spohn, Karsten Seiferlin. Planetary and Space ... In June 2020, the top of the mole reached the regolith surface. The mole entered the surface at an angle of 30 degrees from ... In October 2020, the top of the mole was below the surface of Mars, and a decision was made to scrape two more scoops of ... HP3 mole at the surface of Mars, with the lander scoop pressing on its back cap. The mole, after being covered with sand by the ...
Better surface adsorption. Atomically thin boron nitride has been found to have better surface adsorption capabilities than ... Mechanical properties. Monolayer boron nitride has an average Young's modulus of 0.865 TPa and fracture strength of 70.5 GPa. ... It is similar in geometry as well as physical and thermal properties to its all-carbon analog graphene, but has very different ... Dielectric properties. Atomically thin hexagonal boron nitride is an excellent dielectric substrate for graphene, molybdenum ...
Soil mineral components belonging to a given textural class may thus share properties linked to their specific surface area (e. ... These properties vary through the depth of a soil profile, i.e. through soil horizons. Most of these properties determine the ... It is the surface area to volume ratio (specific surface area) of soil particles and the unbalanced ionic electric charges ... wet surface soil is typically 3 to 6 °C colder than dry surface soil. Soil heat flux refers to the rate at which heat energy ...
The bulk powder properties are the combined effect of particle properties by the conversion of food products in solid state ... The amount and rate of water adsorption depends on the bulk and particles' surface composition, total particle surface area ( ... The properties of food powders including their functionality and their stability are highly dependent on these structures. Many ... In fact, it is very affordable and has been reported to retain most of the nutritional properties of food if dry using ...
Worn and damaged surfaces, which appear unmarked, have yielded inscriptions or other markings on X-rays. Heavily corroded metal ... To produce a radiograph of a painting, the radiographic film is placed on the painted surface and the X-ray tube is placed ... Pigments from the lower painting appear through cracks in the surface layer. The Old Guitarist by Pablo Picasso at the Art ... The radiography of cultural property is the use of radiography to understand intrinsic details about objects. Most commonly ...
"Development of surface acoustic wave devices by Gordon S. Kino and H. J. Shaw". Science, Technology, and the Modern Navy: ... Ruch, J. G.; Kino, G. S. (1968). "Transport Properties of GaAs". Physical Review. 174 (3): 921-931. Bibcode:1968PhRv..174..921R ... Kino, Gordon S.; Shaw, John (1972). "Acoustic Surface Waves". Scientific American. 227 (4): 50-69. Bibcode:1972SciAm.227d..50K ... "Exploring the chemical enhancement for surface-enhanced Raman scattering with Au bowtie nanoantennas". The Journal of Chemical ...
Surface creep is the slow movement of soil and rock debris by gravity which is usually not perceptible except through extended ... ISBN 978-0-8247-8984-8. Styczen, M.E. & Morgan, R.P.C. (1995). "Engineering properties of vegetation". In Morgan, R.P.C. & ... Rainfall, and the surface runoff which may result from rainfall, produces four main types of soil erosion: splash erosion, ... Mass movement is the downward and outward movement of rock and sediments on a sloped surface, mainly due to the force of ...
Brattain spoke on Surface Properties of Semiconductors, Bardeen on Semiconductor Research Leading to the Point Contact ... He continued to study the surface properties of solids and the "transistor effect", so as to better understand the various ... Walter Houser Brattain on including the Nobel Lecture, December 11, 1956 Surface Properties of Semiconductors ( ... doi:10.1002/j.1538-7305.1956.tb03829.x. Brattain, Walter H. (December 11, 1956). "Surface Properties of Semiconductors". ...
H surface does not perturb graphene's electronic properties, whereas the interaction between it and the clean Si(100) surface ... Graphene surfaces can be protected by a coating with materials such as SiN, PMMA and h-BN. In January 2015, the first stable ... The local density of states shows that the bonded C and Si surface states are highly disturbed near the Fermi energy. If the in ... Neto, A Castro; Peres, N. M. R.; Novoselov, K. S.; Geim, A. K. (2009). "The electronic properties of graphene" (PDF). Rev Mod ...
... magnetic and optical properties; chemical reactions at surfaces; defects, nucleation and growth; and new surface and interface ... Surface Review and Letters is an international journal published by World Scientific. It was launched in 1994, and covers both ... Topics covered include surface and interface structures; electronic, ... theoretical and experimental research in physical and properties and processes that occur at the boundaries of materials. ...
"Electronic properties of metals chemisorbed on semiconductor surface and metal/semiconductor interfaces". Progress in Surface ... Zi, Jian; Zhang, Kaiming; Xie, Xide (1997). "Vibrational properties of SiGe superlattices". Progress in Surface Science. ... "Overview of Metal/Semiconductor Interfaces," The Structure of Surfaces. Springer Series in Surface Sciences 24. Berlin: ... Her research work was concentrated in solid state physics, semiconductor physics, and surface physics. Xie Xide was appointed ...
Rotation period, gross surface properties. The Magellan mission mapped the entire planet using a radar altimeter, a task that ... which provide information about the shapes and surface properties of solid bodies, unavailable by other means. Radar can also ... Mapping of Titan's surface and observations of other moons from the Cassini spacecraft. As Venus, Titan also possesses an ... The first human to walk on the surface of another Solar System body was Neil Armstrong, who stepped onto the Moon on July 21, ...
Functional coatings may be applied to change the surface properties of the substrate, such as adhesion, wettability, corrosion ... Walls, J. M. (1981-06-19). "The application of surface analytical techniques to thin films and surface coatings". Thin Solid ... Surface Topography: Metrology and Properties. 8 (4): 045013. Bibcode:2020SuTMP...8d5013T. doi:10.1088/2051-672X/ab9f05. ISSN ... "Study of Various Epoxy-Based Surface Coating Techniques for Anticorrosion Properties". Advances in Materials Science and ...
... and subsequently the surface energy. Changes in surface energy then alter the surface properties of the material. Surface ... Another method of altering surface properties of biomaterials is to coat the surface. Coatings are used in many applications to ... This can be a challenge due to the fact that the majority of biomaterials do not possess the surface properties to covalently ... Plasma modification is one way to alter the surface of biomaterials to enhance their properties. During plasma modification ...
... surface mapping, esp. of polar regions. Venus - first radar detection in 1961. Rotation period, gross surface properties. The ... Radar images provide information about the shapes and surface properties of solid bodies, which cannot be obtained by other ... Measurements included surface roughness and later mapping of shadowed regions near the poles. The next easiest target is Venus ... Mars - Mapping of surface roughness from Arecibo Observatory. The Mars Express mission carries a ground-penetrating radar. ...
Surface Topography: Metrology and Properties. 4 (2): 025002. doi:10.1088/2051-672x/4/2/025002. S2CID 111631084. Harp, Susan R ... 2016). "Surface-specific flow factors for prediction of friction of cross-hatched surfaces". ... The average flow model of Patir and Cheng, is often coupled with the rough surface interaction model of Greenwood and Tripp for ... The average flow model spans the regimes of lubrication where the surfaces are close together and/or touching. The average flow ...
Surface Topography: Metrology and Properties. 10 (2): 025023. doi:10.1088/2051-672X/ac4566. ISSN 2051-672X. Ghorbani, Siamak; ... Other resins in addition to the epoxy may also be used instead of fibers to improve properties such as water absorption. If ... Due to the lack of long-term stability and very poor damping properties, steel fabricated structures are seldom used where high ... Ramakrishna, H. V.; Rai, S. K. (January 2006). "Effect on the Mechanical Properties and Water Absorption of Granite Powder ...
They were among the few surface features visible as the spacecraft entered orbit during a global dust storm. Appearing as faint ... Plescia, J.B. (2004). Morphometric Properties of Martian Volcanoes. J. Geophys. Res. 109(E03003), Table 1. Carr, M.H. (2006). ... ISBN 978-0-511-27041-3.[permanent dead link] Carr, M.H. (2006). The Surface of Mars; Cambridge University Press: New York, p. ... Carr, Michael (2006). The Surface of Mars. Cambridge, UK: Cambridge University Press. p. 63. ...
"Science Experiments - Surface Electrical Properties". Apollo 17 Mission. Lunar and Planetary Institute. Retrieved February 7, ... This was intended to measure the rate of the "gardening" process on the lunar surface, whereby the regolith on the surface is ... and Surface Electrical Properties (SEP) experiment. The Apollo 17 LRV traveled a cumulative distance of approximately 35.7 km ( ... And, Houston, as I step off at the surface at Taurus-Littrow, we'd like to dedicate the first step of Apollo 17 to all those ...
Surface Topography: Metrology and Properties. 4 (3): 034009. Bibcode:2016SuTMP...4c4009S. doi:10.1088/2051-672x/4/3/034009. ... Surface Topography: Metrology and Properties. 4 (3): 034003. doi:10.1088/2051-672X/4/3/034003. S2CID 99433277.{{cite journal ... In the late 1980s, Leighton discovered a new ultrasonic signal that he identified as due to surface waves on the walls of gas ... measurement of the liquid convection and shear from these surface waves; theory on how sound causes the bubbles to generate ...
Zimbleman, J.R. (1985). "Surface Properties of Ascraeus Mons: Dust Deposits on a Tharsis Volcano" (PDF). Lunar and Planetary ... Bell, Jim (2008-06-05). The Martian Surface: Composition, Mineralogy and Physical Properties. ISBN 978-0-521-86698-9. Sleep, ... see Martian surface). The dust forms a mantle over the surface that obscures or mutes much of the fine-scale topography and ... The bulk of the volcano's surface consists of lava flows of the early Amazonian age. The northern flanks of the volcano are ...
"Surface". MESSENGER web site. Johns Hopkins University/Applied Physics Lab. Archived from the original on 30 September 2016. ... ISBN 978-1-4292-5519-6. Plescia, J. B. (2004). "Morphometric properties of Martian volcanoes". Journal of Geophysical Research ... On other planets, peak elevations above an equipotential surface or a reference ellipsoid could be used if enough data is ... Lewis, K. W.; Peters, S.; Gonter, K.; Morrison, S.; Schmerr, N.; Vasavada, A. R.; Gabriel, T. (2019). "A surface gravity ...
Microstrip consists of a strip conductor on the top surface of a dielectric layer and a ground plane on the bottom surface of ... Thermal properties can be important. Thermal expansion changes the electrical properties of lines and can break plated through ... An important property of the TEM mode is that it can be used at low frequencies, all the way down to zero (i.e. DC). Another ... The electrical properties of the substrate of most interest are the relative permittivity (εr) and the loss tangent (δ). The ...
Most of the volcano's surface is mantled with a thick layer of fine dust or ash, giving the volcano's flanks a smooth to ... Plescia, J. B. (2004). "Morphometric properties of Martian volcanoes". Journal of Geophysical Research. 109 (E03003): Table 1. ... Carr, M.H. (2006). The Surface of Mars; Cambridge University Press: Cambridge, UK, p. 57. ...
The function of surface modification is to change the physical and chemical properties of surfaces to improve the functionality ... By altering the surface functionalities using plasma modification, the optimal surface, chemical and physical properties can be ... Ion implantation is an effective surface treatment technique that be used to enhance the surface properties of biomaterials. ... "Deposition of TiN layer on TiNi thin films to improve surface properties". Surface Coatings and Technology. 167 (2-3): 129-13. ...
By surface filtration, the particles are caught on the paper surface. Filter paper is mostly used because of the ability of a ... The filter papers may also be treated with reagents or impregnation to get the right properties. The main application for air ... There are two mechanisms of filtration with paper; volume, and surface. By volume filtration, the particles are caught in the ... Normally particularly long fibrous pulp that is mercerised is used to get these properties. The paper is normally impregnated ...
Marek Kosmulski, "Chemical Properties of Material Surfaces", Marcel Dekker Inc., 2001. Jean-Pierre Jolivet, "Metal Oxide ... For example, the surface charge of adsorbent is described by the ion that lies on the surface of the particle (adsorbent) ... Kosmulski, Marek (2001). "Chemical Properties of Material Surfaces". Surfactant Science. 20011074. doi:10.1201/9780585418049. ... at the surface. This is often the case for pure ("pristine surface") oxides in water. In the presence of specific adsorption, ...
Richard Heap (30 January 2009). "City to 'strip out' St Alphage House". Property Week. Retrieved 24 November 2010. "St Alphage ... House Replacement Surfaces". 5 November 2010. Retrieved 12 June 2021. "London Wall Place , Barbican ...
October 2021). "Surface Properties of Octacalcium Phosphate Nanocrystals Are Crucial for Their Bioactivities". ACS Omega. 6 (39 ... The table below displays various octacalcium phosphate material properties and descriptions of said properties. The three ... The advantageous properties of OCP have made it a primary candidate for many orthopedic uses, and although mass production has ... Though OCP has not been established in the dental field, bioactive properties of OCP have attracted the attention of oral ...
An example of a polar surface is the rocksalt (111) surface. In general, a polar surface is less stable than a nonpolar surface ... The surface acidity and basicity of the oxide depends on the crystal structure and surface orientation. The surfaces of ... Examples of nonpolar surfaces include the rocksalt (100) surface, the rutile (100), (110) and (001) surfaces and the pervoskite ... the surface will be dipoleless and is considered a nonpolar surface. If the structures are different, the surface will have a ...
R.E. Barnhill, R.P. Dube, F.F. Little "Properties of Shepards surfaces," Rocky Mountain Journal of Mathematics, Rocky Mountain ...
However, fatigue properties rely heavily on the surface condition. In this work, in-process surface parameters (three differing ... However, fatigue properties rely heavily on the surface condition. In. this work, in-process surface parameters (three ... often starts at the surface due to surface roughness or defects at the surface, than at internal ... Fatigue Properties of Additively Manufactured. AlSi10Mg-Surface Treatment Effect. Procedia Struct. Integr. 2017,7, 58-66. [ ...
Discover the impact of quaternized polysulfones on hydrophilic/hydrophobic properties, morphology, and compatibility with blood ... 32] M. Rankl, S. Laib and S. Seeger, "Surface Tension Proper-ties of Surface-Coatings for Application in Biodiagnostics ... Surface Properties and Compatibility with Blood of New Quaternized Polysulfones () Raluca Marinica Albu, Ecaterina Avram, ... R. Albu, E. Avram, I. Stoica, E. Ioanid, D. Popovici and S. Ioan, "Surface Properties and Compatibility with Blood of New ...
Formation Mechanisms and Properties of Semifluorinated Molecular Gradients on Silica Surfaces, Langmuir (Accessed September 27 ... ... We use surface-sensitive combinatorial near-edge x-ray absorption fine structure spectroscopy (combi-NEXAFS) to measure the ... position-dependent concentration and molecular orientation of SFOs in the molecular gradients on surfaces. Using the NEXAFS ...
soil structure and surface properties influences the drying process in the. rhizosphere. Future studies should focus on the ... Influence of Physical Microstructure and Surface Properties on the Drying Rate of Water from Simulated Soil Micromodels. ... soil surface properties, including soil water repellency. Studies conducted. using bulk soil may struggle to differentiate ... such as soil structure and surface properties to better elucidate the mechanism. for EPS-mediated water retention in the ...
The filler SiCB with 3 wt % PF surface treatment greatly improved the tensile strength of NR/BR composites and reached 7.1 MPa ... Due to the easy processing and low cost of filler as well as the effectively enhanced mechanical properties of composites, the ... As a result, both the cross-link density and mechanical properties of the obtained composites were effectively enhanced. ... were prepared with different treatment conditions and their effect as fillers on the mechanical properties of filler filled ...
Discover how room size and surface properties affect acoustics. Learn strategies to optimize sound quality in different spaces. ... The Impact of Room Size and Surface Properties on Acoustics. Posted by Acoustical Surfaces on 09/06/2023 6:35 am. , Leave a ... The Impact of Surface Properties on a Space. As noted, the materials used in a space can also drastically affect the sound ... Start with a thorough evaluation of your space, paying close attention to its size and surface properties, as these elements ...
... into cell walls of spruce wood and to deposit OTS layers on its inner and outer surfaces. Distribution and chemical ... Mahltig, B., Arnold, M., Löthman, P. (2010) Surface properties of sol-gel treated thermally modified wood. J. Sol-Gel Sci. ... Hydrophobisation of wood surfaces by combining liquid flame spray (LFS) and plasma treatment: dynamic wetting properties. ... Influence of atmospheric pressure plasma treatments on the surface properties of ligno-cellulosic substrates. Holzforschung 70: ...
... In: ... the oxides have evaporated and thermal diffusion of atoms near the surface has partially reconstructed the surface composition ... The dispersion of active sites available for the chemisorption of H-2 and CO on the Ga3Ni2 catalyst surface was determined by H ... The element with higher affinity to oxygen concentrates on the surface in the oxide form, whereas the element with lower ...
Metamaterials for visible and near infrared antireflective properties and large surface elaboration Author(s): Jean-Baptiste ... Thus, we have summoned the exceptional physical properties of the material patterning. Numerical analysis has been performed on ... We propose two distinctive designs of metamaterials demonstrating antireflective properties in the optical and near infrared ... structures were not only designed to demonstrate a good optical response but were also meant to be feasible on large surfaces ...
The variations of surface temperature during the flight are discussed. ... Atmospheric and Surface Properties from Spectral Radiance Observations in the 4.3-Micron Region ... Evaluation of Turbulent Surface Flux Parameterizations for the Stable Surface Layer over Halley, Antarctica ... Evaluation of Turbulent Surface Flux Parameterizations for the Stable Surface Layer over Halley, Antarctica ...
Surface properties of functional coatings and thin films for semiconductors and applications in the field of renewable energy. ... Surface properties of functional coatings and thin films for semiconductors and applications in the field of renewable energy. ... Analysis of structural properties by means of grazing-incidence X-ray scattering (GISAXS) ... It also covers the right instrument selection for characterizing surfaces and interfaces - from atomic force microscopes and ...
Ojo, Samuel Olukunle (2017). Effect of surface treatment and recycling on the mechanical properties of e-glass. University of ... Effect of surface treatment and recycling on the mechanical properties of e-glass ... Binder removal via fibre spreading did not cause any reduction in the properties of E-glass fibre bundles. However, binder ... in the strengths of the E-glass composites after specified treatment could be correlated to the reduction in properties ...
Viscosity properties of biomembrane surfaces. Description. Cellular processes such as the formation of microtubuli or pores ...
Properties of Screws with Special Surface Treatment" such as fluorine coating and molybdenum disulfide coating. ... Property of Screws with Special Surface Treatment. Comparison of axial force generated by difference of surface treatment. ... It can be confirmed from the above test results that the reducing the friction coefficient on thread surface by special surface ... Surface treatment. Tightening torque. (N・m). Stress. (N/mm2). Axial force. (kN). ...
NCO-sP(EO-stat-PO) surface coatings preserve biochemical properties of RGD peptides. ... surfaces maintain peptide configuration-specific cell-surface interactions or if differences between dissimilar binding ... but was shorter in comparison to the unmodified glass surface. MSC proliferation on cyclic RGDfK modified coatings was 4 times ... but not on linear RGD peptides or the unmodified glass surfaces. Our results indicate specific effects of these adhesion ...
Bolam, Vivienne Jane (1991) The influence of surface treatments on the fatigue properties of an Al-Li-Cu-Mg-Zr (8090) alloy. ... The influence of surface treatments on the fatigue properties of an Al-Li-Cu-Mg-Zr (8090) alloy ... The influence of surface treatments on the fatigue properties of an Al-Li-Cu-Mg-Zr (8090) alloy ... The influence of surface treatments on the fatigue properties of an Al-Li-Cu-Mg-Zr (8090) alloy ...
Electrical and Surface Properties of InAs/InSb Nanowires Cleaned by Atomic Hydrogen. *Mark ... We find that clean and unreconstructed nanowire surfaces can be obtained simultaneously for both InSb and InAs by heating to ... We find that clean and unreconstructed nanowire surfaces can be obtained simultaneously for both InSb and InAs by heating to ... We find that clean and unreconstructed nanowire surfaces can be obtained simultaneously for both InSb and InAs by heating to ...
surface texture, functionality-related properties, grinding, Ni-base superalloy, machinability, Engineering design, Mechanical ... Correlating and evaluating the functionality-related properties with surface texture parameters and specific characteristics of ... Machining-process-induced surface texture plays an indispensable role in determining surface integrity and final functional ... The inadequacy of using 2D single-valued surface profile parameters and the non-ubiquity of using 3D areal surface texture ...
Contact Properties and Surface Reaction Kinetics of Single ZnO Nanowire Devices Fabricated by Dielectrophoresis ... Contact Properties and Surface Reaction Kinetics of Single ZnO Nanowire Devices Fabricated by Dielectrophoresis. In: Oxide- ... Finally, the reaction kinetics of ethanol and water vapors on the NW surface are compared through the analysis of the DC ...
This letter is to inform you that the property's home warranty (home address) secured by Edina Realty Mortgage, may be ... Minnesota sent a note out to her clients letting them know that another scam has surfaced. She has noticed quite a few of these ...
... surface roughness, hydrophobicity, surface energy, and surface morphology. The study manifest that the period and amplitude of ... Effects of periodic surface structures induced by femtosecond laser irradiation on the antibacterial properties of Zr-based ... Various surface properties of the micro-nano structures were tested. Result Experimental results illuminate that laser energy ... The laser texture converts the originally hydrophilic specimen surface into a hydrophobic surface, which greatly reduces the ...
Microstructuring Reduces Friction Losses Between Curved Surfaces by Improving Tribological Properties. December 2005 ... Structuring of Metallic 3D Surfaces by the Etching Process: ... to reduce friction and improve the tribological properties of ... describes a photochemical method used to create microstructures on curved metallic surfaces (for instance, on the inner walls ...
Furthermore, the surface activity of SPPs has also been investigated by using pendant drop tensiometry. All studied SPP samples ... This study also reveals that all SPPs investigated reduce the surface tension of water at high concentrations but at diluted ... condensation nuclei activation properties of Mediterranean pollen types considering organic chemical composition and surface ... condensation nuclei activation properties of Mediterranean pollen types considering organic chemical composition and surface ...
Search by property. A list of all pages that have property "Describe output parameters model" with value "ice flow of an ice ... Model:Alpine3D + (for every grid cell: air and surface tempe … for every grid cell: air and surface temperature, relative ... Model:DetachmentLtdErosion + (_info = { "surface_water__discharg … _info = {,/br, "surface_water__discharge": {,/br, "dtype": ... Property:. Value:. List of results. *Model:DELTA + (Vertically-integrated flow velocities and bed elevations as functions of ...
Co on Fe3O4(001): Towards precise control of surface properties Raquel Gargallo-Caballero; Raquel Gargallo-Caballero ... Vibrational properties of CO2 adsorbed on the Fe3O4 (111) surface: Insights gained from DFT J. Chem. Phys. (March 2020) ... The catalytic properties of specific oxides stem partially from the particular arrangement of Fe and Co cations at the surface ... The surface lattice constant of the resulting surface is half the magnetite one, as evidenced by the disappearance of the first ...
title = "Near-surface mechanical properties of amorphous polymers",. abstract = "Polymeric material near a free surface can ... N2 - Polymeric material near a free surface can have properties which deviate considerably from the bulk properties, Many ... AB - Polymeric material near a free surface can have properties which deviate considerably from the bulk properties, Many ... Polymeric material near a free surface can have properties which deviate considerably from the bulk properties, Many ...
Dielectric Properties and Energy Storage Densities of Poly(vinylidenefluoride) Nanocomposite with Surface Hydroxylated Cube ... Dielectric Properties and Energy Storage Densities of Poly(vinylidenefluoride) Nanocomposite with Surface Hydroxylated Cube ... Dielectric constants of the nanocomposite with surface hydroxylated BST-NPs (BST-NPs-OH) were higher as compared with those of ... Liu, S., Xiu, S., Shen, B., Zhai, J., & Kong, L. B. (2016). Dielectric Properties and Energy Storage Densities of Poly( ...
  • Despite the fact that newly developed in-process contour parameters are able to reduce the surface roughness significantly, only a minor improvement in fatigue properties could be observed: Crack initiation is caused by sharp, microscopic notches at the surface in combination with high tensile residual stresses at the surface, which are present on all in-process contour parameter specimens. (
  • The post-process parameter sets, turning and shot peening, both improve fatigue behaviour significantly: Turned specimens show lowest surface roughness, while, for shot peened specimens, the tensile residual stresses of the surface radially shifted from the surface towards the centre of the specimens, which counteracts the crack initiation at the surface. (
  • The laser treatment greatly improves the surface roughness of the sample. (
  • Conclusion This article comprehensively discusses the influence mechanism of nano- and microscale structures on bacterial adhesion from four aspects: surface roughness, hydrophobicity, surface energy, and surface morphology. (
  • Aim and Objectives: To evaluate and compare the abrasive effect of Ultrasonic and powered toothbrush on the surface roughness of enamel, Type II and IX GC Fuji cement. (
  • Also, the type II GIC had greater surface roughness compared to type IX GIC. (
  • For the first time, phenolic formaldehyde resin (PF)-treated silica carbon black (SiCB) were prepared with different treatment conditions and their effect as fillers on the mechanical properties of filler filled natural rubber/butadiene rubber (NR/BR) composites were investigated in detail. (
  • As a result, both the cross-link density and mechanical properties of the obtained composites were effectively enhanced. (
  • The mechanical properties of the oxides are assessed using scratch adhesion tests and tensile fracture experiments. (
  • we therefore investigate the hypothesis that the near-surface mechanical properties of amorphous polymers differ from the bulk properties owing to the presence of an absolute length scale. (
  • There are few studies that fully characterize the effect of the filler size on the surface, optical and mechanical properties of resin composites. (
  • To determine the influence of the filler size content on surface, optical and mechanical properties before and after accelerated aging. (
  • Mechanical properties decreased for all materials when submitted to immersion in ethanol. (
  • Titanium is the material of choice, as it has good mechanical properties. (
  • Results showed that micromodels with more hydrophobic surfaces took four times longer to completely dry compared to micromodels with less hydrophobic surfaces. (
  • Diffusion uses several uneven surfaces to disperse the sound waves in various directions, reducing the intensity of reflections and creating a more evenly distributed sound throughout the space. (
  • The results obtained are useful in biomedical applications, including evaluation of bacterial adhesion to the surfaces, or utilization of modified polysulfones as semipermeable membranes. (
  • We found that all the formed surface structures can reduce the adhesion of Escherichia coli and Staphylococcus aureus. (
  • In detail, the adhesion rate of bacteria on the surface of SWPSS is the lowest. (
  • There is very little known about the surface structures of transition metal oxides, but their bulk crystal structures are well researched. (
  • The approach to determine the surface structure is to assume the oxides are ideal crystal, where the bulk atomic arrangement is maintained up to and including the surface plane. (
  • The surfaces will be generated by cleavages along the planes of the bulk crystal structure. (
  • However, when a crystal is cleaved along a particular plane, the position of surface ions will differ from the bulk structure. (
  • Micromodels of each design were then surface-treated to exhibit properties of rhizosphere versus bulk soil. (
  • CO2 conversion experiments were performed by using the catalyst material reduced in hydrogen at temperatures of 300 and 600 degrees C. Results: XPS study of the Ga3Ni2 surface subjected to different heating-annealing conditions has revealed that the concentration of Ga at the oxidized surface is strongly enhanced and the concentration of Ni is strongly depleted with respect to the values in the bulk. (
  • By annealing the surface at 600 degrees C in ultra-high vacuum, the oxides have evaporated and thermal diffusion of atoms near the surface has partially reconstructed the surface composition towards the energetically more favorable bulk value, whereas annealing at a lower temperature of 300 degrees C was ineffective to change the surface composition. (
  • Polymeric material near a free surface can have properties which deviate considerably from the bulk properties, Many researchers have reported a reduced glass transition temperature in thin polymeric films and attributed this effect to an enhanced segmental mobility near a free surface. (
  • Distribution functions in bulk and at surfaces in relation to experiments, potential of mean force, Debye-Hückel theory. (
  • The relative acidity and basicity of the atoms present on the surface of metal oxides are also affected by the coordination of the metal cation and oxygen anion, which alter the catalytic properties of these compounds. (
  • For this reason, structural defects in transition metal oxides greatly influence their catalytic properties. (
  • It also covers the right instrument selection for characterizing surfaces and interfaces - from atomic force microscopes and nano scratch testers to grazing-incidence X-ray scattering (GISAXS). (
  • Starting with pristine nanowires covered only by the native oxide formed through exposure to ambient air, we investigate the effect of atomic hydrogen cleaning on the surface chemistry and electrical performance. (
  • Through electrical measurement of individual nanowires, we observe an increase in conductivity of 2 orders of magnitude by atomic hydrogen cleaning, which we relate through theoretical simulation to the contact-nanowire junction and nanowire surface Fermi level pinning. (
  • Our study demonstrates the significant potential of atomic hydrogen cleaning regarding device fabrication when high quality contacts or complete control of the surface structure is required. (
  • In the colloidal approach, the main emphasis has been on the quantification of bacterial interaction forces, including a comparison with physico-chemical theory, the probing of bacterial surface heterogeneity using atomic force microscopy (AFM) and a focus on irreversible interactions and bond aging. (
  • Contours with low line energy have a slightly positive effect on fatigue strength because less pores can be found at the surface and subsurface area, which even more greatly promotes an early crack initiation. (
  • The element with higher affinity to oxygen concentrates on the surface in the oxide form, whereas the element with lower affinity sinks into the subsurface region. (
  • Co is deposited at room temperature on the reconstructed magnetite (001) surface filling first the subsurface octahedral vacancies and then occupying adatom sites on the surface. (
  • 11] A. Filimon, E. Avram and S. Ioan, "Influence of Mixted Solvents and Temperature on the Solution Properties of Quaternized Polysulfones," Journal of Macromolecular Science, Part B: Physics, Vol. 46, No. 3, May 2007, pp. 503-520. (
  • The dispersion of active sites available for the chemisorption of H-2 and CO on the Ga3Ni2 catalyst surface was determined by H-2 and CO temperature-programmed desorption. (
  • Catalytic tests were in agreement with the XPS results, where an increased CO2 conversion for the catalyst reduced with hydrogen at a higher temperature followed an increased Ni/Ga surface concentration ratio. (
  • The variations of surface temperature during the flight are discussed. (
  • In this talk I will discuss the arrangement and interfacial electronic properties of ordered molecular domains that form through interadsorbate hydrogen bonding at noble metal surfaces probed with high spatial resolution, low temperature scanning tunneling microscopy (STM) and spectroscopy, as well as supporting density functional theory (DFT) calculations. (
  • The purpose of the project is to study Backahill's properties within a defined geographical area and evaluate the properties' exposure to climate threats in terms of temperature, wind, water (rising sea level, high flows, precipitation and torrential rain) and land (for example if there is a risk of landslides, landslides or erosion in the area). (
  • 1] M. Barikani and S. Mehdipour-Ataei, "Synthesis, Char-acterization and Thermal Properties of Novel Arylene Sulfone Ether Polyimides and Polyamides," Journal of Polymers Science, Part A: Polymer Chemistry, Vol. 38, No. 9, May 2000, pp. 1487-1492. (
  • In the present study, we investigated whether the NCO-sP(EO-stat-PO) surfaces maintain peptide configuration-specific cell-surface interactions or if differences between dissimilar binding molecules are concealed by the coating. (
  • The growth of chemically and electronically tuned, monolayer thin films, including organic molecules on metallic surfaces, is steered by the balance of adsorbate-surface and interadsorbate interactions. (
  • His research interests focus on studying interactions between surfaces and adsorbates that induce morphological transitions, change electronic characteristics, determine growth and ordering, and drive surface reaction dynamics as they relate to energy generation, nanoscale electronics, and chemical sensors. (
  • The research field of bacterial interactions, which is characterized by the apparent dichotomy between colloidal surface properties and specific interactions, has seen significant recent progress along both lines. (
  • Ubbink, J & Schär-Zammaretti, P 2007, ' Colloidal properties and specific interactions of bacterial surfaces ', Current Opinion in Colloid and Interface Science , vol. 12, no. 4-5, pp. 263-270. (
  • Controlling the Structure, Properties and Surface Reactivity of Clickable Azide-Functionalized Au 25 (SR) 18 Nanocluster Platforms Through Regioisomeric Ligand Modifications. (
  • Objective In this essay, a femtosecond laser is used to create various structures on the surface of Zr-based amorphous material. (
  • This precise control of the near-surface Co atoms location opens up the way to accurately tune the surface physical and magnetic properties of mixed spinel oxides. (
  • Gets the cylindrical surface geometry. (
  • When a crystal of a binary oxide is cleaved to generate two new surfaces, each solid's charge remains neutral. (
  • The fatigue results are discussed in terms of the microstructure of the alloys and the physical properties of the oxide films and their effect on the underlying substrate. (
  • Surface modification of superparamagnetic iron oxide nanoparticles (SPIONs) has been introduced with lauric acid and oleic acid via co-precipitation and thermal decomposition methods, respectively. (
  • When in contact with oxygen, a 2- to 10-nm oxide layer is formed on the surface, which has been described as osteoconductive. (
  • We have investigated the instability of the surface composition to oxidation of the Ga3Ni2 noble metal-free intermetallic compound, a new catalyst for the CO2 reduction to CO, CH4 and methanol. (
  • MSC proliferation on cyclic RGDfK modified coatings was 4 times higher than on films functionalized by linear gRGDsc sequences, underlining that the NCO-sP(EO-stat-PO) film preserves the configuration-specific biochemical peptide properties. (
  • The first section of this study involves the modification of SPIONs to obtain adequate stability of SPIONs in suspension and suitable interaction between hydrophobic PHBV solution and the surfaces of SPIONs during preparation of magnetic microspheres, which is presented in the second part of the study. (
  • They can undergo cluster-surface strain -promoted alkyne - azide cycloaddition (CS-SPAAC) chemistry with complementary strained- alkynes . (
  • The ability to conduct CS-SPAAC chemistry without altering the parent nanocluster structure is different as the isomeric form of the surface ligand is changed, with the [Au25 (SCH2 CH2 -p-C6 H4 -N3 )18 ]1- isomer having the highest reaction rates, while the [Au25 (SCH2 CH2 -o-C6 H4 -N3 )18 ]1- isomer is not stable following CS-SPAAC. (
  • This process, presented at the PCMI Conference in Atlanta in September 2005, describes a photochemical method used to create microstructures on curved metallic surfaces (for instance, on the inner walls of cylinder liners). (
  • As a result, this superconducting gap structure change happen in the same doping range where changes of the Fermi surface topology were reported, implying that the nodal structure and Fermi surface topology are closely linked. (
  • Hydrophilic/hydrophobic properties, morphological aspects and compatibility with red blood cells and platelets are affected by the alkyl radicals and by history of the formed films. (
  • Methods Through the raster scan mode, under different laser energy densities, LIPSS (Laser-induced periodic surface structures), SWPSS (Super-wavelength periodic surface structure) and microporous structures were obtained in the experiment. (
  • Given that the conventional approaches (Fourier or wavelet transform) are limited to either periodicity or feature-scale characterization, our work contributes with the proposal of a transformation which combines Fourier and wavelet merits to quantify simultaneously the period and feature scale of a periodic or almost periodic surface pattern. (
  • Two extreme cases are the fully random surface where no point correlations exist and the fully periodic surface where a fixed surface unit is repeated endlessly along surface with a specific translation vector. (
  • The mechanism whereby EPS promotes increased moisture content may include (i) water being held within the swelling polymer matrix during wet conditions and remaining hydrated during dry soil conditions, (ii) promotion of soil particle aggregation which increases the capillary forces on water in small intra-particle soil pores, and (iii) altered soil surface properties, including soil water repellency. (
  • The output of our study has been (a) a detailed investigation of the mathematical properties of the proposed period-scale transform (PST) along with its relationship with other well-known transforms, (b) a presentation of some examples of PST of model 1D periodic surfaces to identify its benefits, and (c) first applications of PST in real profiles extracted from experimental polymer surfaces after plasma treatment. (
  • This study also reveals that all SPPs investigated reduce the surface tension of water at high concentrations but at diluted concentrations (such as those of activation in the CCNC), the water surface tension value is a good approximation in K¨ohler theory. (
  • We use surface-sensitive combinatorial near-edge x-ray absorption fine structure spectroscopy (combi-NEXAFS) to measure the position-dependent concentration and molecular orientation of SFO's in the molecular gradients on surfaces. (
  • Antigens are molecular structures on the surface of viruses that are recognized by the immune system and can trigger an immune response (such as antibody production). (
  • Although there are already many existing standard parameters for quantitatively characterizing the machined surface, accurately describing and effectively correlating the 3D surface texture parameters and specific characteristics with the relevant functional performances in practice, are still not well solved. (
  • The surface characteristics of various materials, as well as their chemical and organic origin, when suspended in water, can influence colonization by bacteria [5]. (
  • The presence of Tb 2 Pc 3 molecules on the surface are inspected using scanning probe microscopy with submolecular resolution supported by density functional theory (DFT) calculations and additional chemical analysis. (
  • Although much of our work is relevant to modern industrial technology, most of it is basic research which aims to answer basic questions about the nature and behaviour of surfaces and molecules. (
  • R.E. Barnhill, R.P. Dube, F.F. Little "Properties of Shepard's surfaces," Rocky Mountain Journal of Mathematics, Rocky Mountain J. Math. (
  • Bacteria have been shown to regulate moisture content in soil through the secretion of extracellular polysaccharides (EPS), a polymeric substance whose properties vary with bacterial species and environmental conditions. (
  • Here we employed emulated soil micromodels with systematically controlled EPS effects such as soil structure and surface properties to better elucidate the mechanism for EPS-mediated water retention in the rhizosphere. (
  • These results illustrate the mechanisms whereby soil structure and surface properties influences the drying process in the rhizosphere. (
  • The amount, or intensity, of gamma rays depends on the type of radioactive material at the site, its concentration and depth from the surface, and physical distribution in the soil. (
  • Transition metal oxides have a wide variety of surface structures which affect the surface energy of these compounds and influence their chemical properties. (
  • The acidic and basic sites on the surface of metal oxides are commonly characterized via infrared spectroscopy, calorimetry among other techniques. (
  • Since very little is known about the surface Gibbs energy of transition metal oxides, polarity of the surface and the degree of coordinative unsaturation of a surface cation are used to compare the stabilities of different surface structures. (
  • Mesoscopic oxides constitute a fascinating family of materials due to the wide range of functional properties that they offer. (
  • The ongoing challenge associated with these systems comes from the ever growing demand of miniaturization and device performance in a variety of applications, which calls for an extremely high level of control over the structural properties at the nanoscale. (
  • In order to understand and get control of these properties, it is necessary to find ways and tools to characterize surface morphology in a quantitative and concise way. (
  • The most widely used method to detect and characterize periodicity of a surface is the Fourier transform (FT) and the diagram of the square of its amplitude versus frequency called power spectral density (PSD). (
  • Due to the operating conditions encountered, the fatigue properties of any alloy are of paramount importance, such that control of the microstructure and surface finish to maximise fatigue resistance is required. (
  • The laser texture converts the originally hydrophilic specimen surface into a hydrophobic surface, which greatly reduces the material's surface energy. (
  • From the tiny scales of nanotechnology to the much larger feature sizes of geophysics and ocean studies, the morphology of surfaces plays an important role springing from its critical impact on surface properties and functionalities [ 1 ]. (
  • In technology, on the other side, and more specifically in nanotechnology where surface morphology can be controlled at nanometer scale, it is more common to fabricate surfaces either by top-down techniques or self-assembly processes with almost periodic structures consisting of similar humps or holes or trenches arranged in a periodic manner [ 2 ]. (
  • The same feature of (almost) periodicity is encountered in biological structures with an outstanding example-the surface morphology of moth eyes which has played a principal role in recent biomimetic technology [ 3 ]. (
  • Methods: The instability of the oxidized Ga3Ni2 surface composition to different heating-annealing conditions was studied by X-ray photoelectron spectroscopy (XPS), used to determine the elemental composition and the chemical bonding in the near-surface region. (
  • To fine-tune structure-property correlations of thiolate-protected gold nanoclusters through post-assembly surface modifications, we report the synthesis of the o, m, and p regioisomeric forms of the anionic azide -functionalized [Au25 (SCH2 CH2 -C6 H4 -N3 )18 ]1- platform. (
  • The research reported in this paper addressed this issue by proposing a practical means which makes use of both 3D surface texture parameters and statistical functions for surface geometrical characterization and functional correlation and evaluation. (
  • To better investigate the influence of machining-induced surface texture and its characterization on the functionality-related performance of machined surfaces, Ni-based superalloy GH4169, a typical difficult-to-machine material widely used in aircraft industry, was selected for the machining experiment. (
  • The quantitative characterization of such surface structures demands mathematical methods able to reveal both period- and feature-scale aspects. (
  • The Scotch-Brite™ PD Surface Conditioning Low Stretch Belt is well-suited for high belt tension applications and has a loftier web especially resistant to loading on soft and/or oily materials. (
  • Surface tension does not depend on the area of the free-surface of the liquid. (
  • For a small liquid drop, the surface tension is predominant and the effect of gravity is negligible. (
  • Surface tension and iii. (
  • Without normal surfactant, the tissue surrounding the air sacs in the lungs (the alveoli) sticks together (because of a force called surface tension) after exhalation, causing the alveoli to collapse. (
  • This substance lowers surface tension, which keeps the alveoli from collapsing after exhalation and makes breathing easy. (
  • These two proteins help spread the surfactant across the surface of the lung tissue, aiding in the surface tension-lowering property of surfactant. (
  • The loss of functional surfactant raises surface tension in the alveoli, causing severe breathing problems. (
  • However, fatigue properties rely heavily on the surface condition. (
  • In the present work the properties of the 8090 (Al-Li-Cu-Mg-Zr) alloy are studied, with particular emphasis on the fatigue properties after chromic acid anodising. (
  • 12] S. Ioan, A. Filimon and E. Avram, "Influence of the De- gree of Substitution on the Solution Properties of Chloro- methylated Polysulfone," Journal of Applied Poly- mer Science, Vol. 101, No. 1, April 2006, pp. 524-531. (
  • Some are man-made (for example, created by ocean dumping), the surfaces of which may differ from one location to another. (
  • This was also proven via magnetic susceptibility measurement as a higher value of this magnetic property was detected for PHBV/SPIONs Lauric microspheres. (
  • On the other hand, the application of bare SPIONs has shown some limitations as the magnetic properties diminish due to exposure to air 15 or due to variations in storage conditions 16 . (
  • The odor is a distinctive warning property of this liquid compound. (
  • Prevention resources should focus on improved control of contaminants and improved transitions between surfaces and conditions. (
  • The tools of calculus can be used in a variety of applications to compute properties and to describe the behavior of functions, curves, surfaces, solids and many other mathematical objects. (
  • The inadequacy of using 2D single-valued surface profile parameters and the non-ubiquity of using 3D areal surface texture parameters in industry are the main obstacles. (
  • Two kinds of mechanically-processed surfaces, one ground and the other turned, both having an identical value of 3D arithmetic mean deviation (Sa), were quantitatively characterized and analyzed using 2D and 3D surface texture parameters. (
  • Correlation between the 3D surface texture parameters or statistical functions with the corresponding functional performance, e.g. contact, running-in wear and lubricant retention, were then established. (
  • This study emphasized on the effectiveness and veracity of the 3D surface texture parameters and statistical functions in characterizing and evaluating machined-surface performance along with the traditional 2D parameters. (
  • It is defined as the angle between the tangent to the liquid surface and the solid inside the liquid. (
  • Compute a tangent line to a curve or compute a tangent plane or a normal line to a surface. (
  • The stability of these surface structures are evaluated by surface polarity, the degree of coordinative unsaturation and defect sites. (
  • Also, defect sites can have a huge impact on the surface stability. (
  • Therefore, it is very important to introduce surface modifications or protective coating on SPIONs to provide protection to their intrinsic properties while maintaining their stability. (
  • Under basal conditions, MSC expressed osteogenic marker genes after 14 days on cyclic RGD peptides, but not on linear RGD peptides or the unmodified glass surfaces. (
  • Conformable disc conditions surfaces without gounging, undercutting, or damaging the base material. (
  • Thus, we have summoned the exceptional physical properties of the material patterning. (
  • Conclusions: The instability of the active surface chemical composition to oxidation in air must be taken into account when considering noble metal-free intermetallic catalysts as alternatives to the conventional catalysts based on noble metals. (
  • By showing realistic geometric parameters, the structures were not only designed to demonstrate a good optical response but were also meant to be feasible on large surfaces by lithographic methods such as micro contact printing or nano-imprint lithography. (
  • Binder removal via fibre spreading did not cause any reduction in the properties of E-glass fibre bundles. (
  • It can be confirmed from the above test results that the reducing the friction coefficient on thread surface by special surface treatment will achieve higher axial force than screws with no surface treatment subject to the same tightening torque. (
  • A comparison between the experimental and numerical results indeed indicates that a length-scale effect is present near the surface. (
  • Conclusion: The results indicate that the use of powered toothbrushes causes significantly greater wear of the tooth surface than the use of ultrasonic toothbrushes on enamel and GIC. (
  • Our Scotch-Brite™ PD Surface Conditioning Low Stretch (PDF, 50 Kb) is a thicker, more springy version of our standard Scotch-Brite™ SC Surface Conditioning Low Stretch Belt. (
  • Scotch-Brite™ Precision Surface Conditioning Discs set a new standard in surface conditioning performance. (
  • Meet the next advancement in surface conditioning technologies: Scotch-Brite™ Precision Surface Conditioning Discs. (
  • Newly created surfaces will tend to minimize the surface Gibbs energy, through reconstruction, to obtain the most thermodynamically stable surface. (
  • A big concern in this endeavor is the presence of randomness and its co-existence with order on the arrangement of peaks and valleys on surfaces. (
  • Indeed, FT and mainly PSD are very sensitive to the presence of periodic repetition of a specific surface feature and display it with a well-defined peak at the frequency of repetition which is the inverse of period. (
  • Surface water measurements for radionuclides at the HISS showed the presence of total uranium ranging from bkg to 5 pCi/L, Th-230 ranging from 0.1 to 0.9 pCi/L, and Ra-226 ranging from 0.1 to 0.3 pCi/L ( Tables 1 , 2 ). (
  • If the structures are identical, the surface will be dipoleless and is considered a nonpolar surface. (
  • If the structures are different, the surface will have a strong dipole and is considered a polar surface. (
  • Various surface properties of the micro-nano structures were tested. (
  • Such structures act as oil-retaining depressions to reduce friction and improve the tribological properties of components involved in this process. (
  • Finally, the reaction kinetics of ethanol and water vapors on the NW surface are compared through the analysis of the DC current under direct exposure to gas flows. (
  • Although there is no surface water at the NPL site that could be contaminated, Coldwater Creek forms a boundary of the site ( Figure 1 ) and contaminated surface runoff has entered the creek ( Mitre, 1988 ). (
  • Surface water sampling in Coldwater Creek by the SLAPS showed the maximum concentration of total uranium, including background, was 4 pCi/L. The concentrations of Th-230 and Ra-226 were at or below bkg ( Bechtel, 1989a ). (