Thin layers of tissue which cover parts of the body, separate adjacent cavities, or connect adjacent structures.
Lipids, predominantly phospholipids, cholesterol and small amounts of glycolipids found in membranes including cellular and intracellular membranes. These lipids may be arranged in bilayers in the membranes with integral proteins between the layers and peripheral proteins attached to the outside. Membrane lipids are required for active transport, several enzymatic activities and membrane formation.
The lipid- and protein-containing, selectively permeable membrane that surrounds the cytoplasm in prokaryotic and eukaryotic cells.
Thin structures that encapsulate subcellular structures or ORGANELLES in EUKARYOTIC CELLS. They include a variety of membranes associated with the CELL NUCLEUS; the MITOCHONDRIA; the GOLGI APPARATUS; the ENDOPLASMIC RETICULUM; LYSOSOMES; PLASTIDS; and VACUOLES.
The voltage differences across a membrane. For cellular membranes they are computed by subtracting the voltage measured outside the membrane from the voltage measured inside the membrane. They result from differences of inside versus outside concentration of potassium, sodium, chloride, and other ions across cells' or ORGANELLES membranes. For excitable cells, the resting membrane potentials range between -30 and -100 millivolts. Physical, chemical, or electrical stimuli can make a membrane potential more negative (hyperpolarization), or less negative (depolarization).
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.
The semi-permeable outer structure of a red blood cell. It is known as a red cell 'ghost' after HEMOLYSIS.
The motion of phospholipid molecules within the lipid bilayer, dependent on the classes of phospholipids present, their fatty acid composition and degree of unsaturation of the acyl chains, the cholesterol concentration, and temperature.
A quality of cell membranes which permits the passage of solvents and solutes into and out of cells.
A darkly stained mat-like EXTRACELLULAR MATRIX (ECM) that separates cell layers, such as EPITHELIUM from ENDOTHELIUM or a layer of CONNECTIVE TISSUE. The ECM layer that supports an overlying EPITHELIUM or ENDOTHELIUM is called basal lamina. Basement membrane (BM) can be formed by the fusion of either two adjacent basal laminae or a basal lamina with an adjacent reticular lamina of connective tissue. BM, composed mainly of TYPE IV COLLAGEN; glycoprotein LAMININ; and PROTEOGLYCAN, provides barriers as well as channels between interacting cell layers.
Membrane proteins whose primary function is to facilitate the transport of molecules across a biological membrane. Included in this broad category are proteins involved in active transport (BIOLOGICAL TRANSPORT, ACTIVE), facilitated transport and ION CHANNELS.
Glycoproteins found on the membrane or surface of cells.
Layers of lipid molecules which are two molecules thick. Bilayer systems are frequently studied as models of biological membranes.
The two lipoprotein layers in the MITOCHONDRION. The outer membrane encloses the entire mitochondrion and contains channels with TRANSPORT PROTEINS to move molecules and ions in and out of the organelle. The inner membrane folds into cristae and contains many ENZYMES important to cell METABOLISM and energy production (MITOCHONDRIAL ATP SYNTHASE).
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.
The process of moving proteins from one cellular compartment (including extracellular) to another by various sorting and transport mechanisms such as gated transport, protein translocation, and vesicular transport.
Cell membranes associated with synapses. Both presynaptic and postsynaptic membranes are included along with their integral or tightly associated specializations for the release or reception of transmitters.
Established cell cultures that have the potential to propagate indefinitely.
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.
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.
A basic element found in nearly all organized tissues. It is a member of the alkaline earth family of metals with the atomic symbol Ca, atomic number 20, and atomic weight 40. Calcium is the most abundant mineral in the body and combines with phosphorus to form calcium phosphate in the bones and teeth. It is essential for the normal functioning of nerves and muscles and plays a role in blood coagulation (as factor IV) and in many enzymatic processes.
Theoretical representations that simulate the behavior or activity of biological processes or diseases. For disease models in living animals, DISEASE MODELS, ANIMAL is available. Biological models include the use of mathematical equations, computers, and other electronic equipment.
Techniques to partition various components of the cell into SUBCELLULAR FRACTIONS.
The level of protein structure in which combinations of secondary protein structures (alpha helices, beta sheets, loop regions, and motifs) pack together to form folded shapes called domains. Disulfide bridges between cysteines in two different parts of the polypeptide chain along with other interactions between the chains play a role in the formation and stabilization of tertiary structure. Small proteins usually consist of only one domain but larger proteins may contain a number of domains connected by segments of polypeptide chain which lack regular secondary structure.
Transport proteins that carry specific substances in the blood or across cell membranes.
The thin layers of tissue that surround the developing embryo. There are four extra-embryonic membranes commonly found in VERTEBRATES, such as REPTILES; BIRDS; and MAMMALS. They are the YOLK SAC, the ALLANTOIS, the AMNION, and the CHORION. These membranes provide protection and means to transport nutrients and wastes.
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)
Purifying or cleansing agents, usually salts of long-chain aliphatic bases or acids, that exert cleansing (oil-dissolving) and antimicrobial effects through a surface action that depends on possessing both hydrophilic and hydrophobic properties.
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.
Electrophoresis in which a polyacrylamide gel is used as the diffusion medium.
A system of cisternae in the CYTOPLASM of many cells. In places the endoplasmic reticulum is continuous with the plasma membrane (CELL MEMBRANE) or outer membrane of the nuclear envelope. If the outer surfaces of the endoplasmic reticulum membranes are coated with ribosomes, the endoplasmic reticulum is said to be rough-surfaced (ENDOPLASMIC RETICULUM, ROUGH); otherwise it is said to be smooth-surfaced (ENDOPLASMIC RETICULUM, SMOOTH). (King & Stansfield, A Dictionary of Genetics, 4th ed)
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.
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.
A stack of flattened vesicles that functions in posttranslational processing and sorting of proteins, receiving them from the rough ENDOPLASMIC RETICULUM and directing them to secretory vesicles, LYSOSOMES, or the CELL MEMBRANE. The movement of proteins takes place by transfer vesicles that bud off from the rough endoplasmic reticulum or Golgi apparatus and fuse with the Golgi, lysosomes or cell membrane. (From Glick, Glossary of Biochemistry and Molecular Biology, 1990)
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.
Proteins found in any species of bacterium.
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.
Preparation for electron microscopy of minute replicas of exposed surfaces of the cell which have been ruptured in the frozen state. The specimen is frozen, then cleaved under high vacuum at the same temperature. The exposed surface is shadowed with carbon and platinum and coated with carbon to obtain a carbon replica.
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 sum of the weight of all the atoms in a molecule.
Recombinant proteins produced by the GENETIC TRANSLATION of fused genes formed by the combination of NUCLEIC ACID REGULATORY SEQUENCES of one or more genes with the protein coding sequences of one or more genes.
Structures which are part of the CELL MEMBRANE or have cell membrane as a major part of their structure.
An element in the alkali group of metals with an atomic symbol K, atomic number 19, and atomic weight 39.10. It is the chief cation in the intracellular fluid of muscle and other cells. Potassium ion is a strong electrolyte that plays a significant role in the regulation of fluid volume and maintenance of the WATER-ELECTROLYTE BALANCE.
Minute projections of cell membranes which greatly increase the surface area of the cell.
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.
Components of a cell produced by various separation techniques which, though they disrupt the delicate anatomy of a cell, preserve the structure and physiology of its functioning constituents for biochemical and ultrastructural analysis. (From Alberts et al., Molecular Biology of the Cell, 2d ed, p163)
Semiautonomous, self-reproducing organelles that occur in the cytoplasm of all cells of most, but not all, eukaryotes. Each mitochondrion is surrounded by a double limiting membrane. The inner membrane is highly invaginated, and its projections are called cristae. Mitochondria are the sites of the reactions of oxidative phosphorylation, which result in the formation of ATP. They contain distinctive RIBOSOMES, transfer RNAs (RNA, TRANSFER); AMINO ACYL T RNA SYNTHETASES; and elongation and termination factors. Mitochondria depend upon genes within the nucleus of the cells in which they reside for many essential messenger RNAs (RNA, MESSENGER). Mitochondria are believed to have arisen from aerobic bacteria that established a symbiotic relationship with primitive protoeukaryotes. (King & Stansfield, A Dictionary of Genetics, 4th ed)
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.
The movement of materials across cell membranes and epithelial layers against an electrochemical gradient, requiring the expenditure of metabolic energy.
Cellular uptake of extracellular materials within membrane-limited vacuoles or microvesicles. ENDOSOMES play a central role in endocytosis.
A light microscopic technique in which only a small spot is illuminated and observed at a time. An image is constructed through point-by-point scanning of the field in this manner. Light sources may be conventional or laser, and fluorescence or transmitted observations are possible.
The part of a cell that contains the CYTOSOL and small structures excluding the CELL NUCLEUS; MITOCHONDRIA; and large VACUOLES. (Glick, Glossary of Biochemistry and Molecular Biology, 1990)
Red blood cells. Mature erythrocytes are non-nucleated, biconcave disks containing HEMOGLOBIN whose function is to transport OXYGEN.
Models used experimentally or theoretically to study molecular shape, electronic properties, or interactions; includes analogous molecules, computer-generated graphics, and mechanical structures.
The parts of a macromolecule that directly participate in its specific combination with another molecule.
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 voltage difference, normally maintained at approximately -180mV, across the INNER MITOCHONDRIAL MEMBRANE, by a net movement of positive charge across the membrane. It is a major component of the PROTON MOTIVE FORCE in MITOCHONDRIA used to drive the synthesis of ATP.
Functionally and structurally differentiated, purple-pigmented regions of the cytoplasmic membrane of some strains of Halobacterium halobium. The membrane develops under anaerobic conditions and is made almost entirely of the purple pigment BACTERIORHODOPSINS. (From Singleton & Sainsbury Dictionary of Microbiology and Molecular Biology, 2d ed)
Gated, ion-selective glycoproteins that traverse membranes. The stimulus for ION CHANNEL GATING can be due to a variety of stimuli such as LIGANDS, a TRANSMEMBRANE POTENTIAL DIFFERENCE, mechanical deformation or through INTRACELLULAR SIGNALING PEPTIDES AND PROTEINS.
Elements of limited time intervals, contributing to particular results or situations.
A member of the alkali group of metals. It has the atomic symbol Na, atomic number 11, and atomic weight 23.
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 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)
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.
The sequence of PURINES and PYRIMIDINES in nucleic acids and polynucleotides. It is also called nucleotide sequence.
Test for tissue antigen using either a direct method, by conjugation of antibody with fluorescent dye (FLUORESCENT ANTIBODY TECHNIQUE, DIRECT) or an indirect method, by formation of antigen-antibody complex which is then labeled with fluorescein-conjugated anti-immunoglobulin antibody (FLUORESCENT ANTIBODY TECHNIQUE, INDIRECT). The tissue is then examined by fluorescence microscopy.
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.
An adenine nucleotide containing three phosphate groups esterified to the sugar moiety. In addition to its crucial roles in metabolism adenosine triphosphate is a neurotransmitter.
The ability of a substrate to allow the passage of ELECTRONS.
A fold of the mucous membrane of the CONJUNCTIVA in many animals. At rest, it is hidden in the medial canthus. It can extend to cover part or all of the cornea to help clean the CORNEA.
The inner layer of CHOROID, also called the lamina basalis choroideae, located adjacent to the RETINAL PIGMENT EPITHELIUM; (RPE) of the EYE. It is a membrane composed of the basement membranes of the choriocapillaris ENDOTHELIUM and that of the RPE. The membrane stops at the OPTIC NERVE, as does the RPE.
Property of membranes and other structures to permit passage of light, heat, gases, liquids, metabolites, and mineral ions.
The intracellular transfer of information (biological activation/inhibition) through a signal pathway. In each signal transduction system, an activation/inhibition signal from a biologically active molecule (hormone, neurotransmitter) is mediated via the coupling of a receptor/enzyme to a second messenger system or to an ion channel. Signal transduction plays an important role in activating cellular functions, cell differentiation, and cell proliferation. Examples of signal transduction systems are the GAMMA-AMINOBUTYRIC ACID-postsynaptic receptor-calcium ion channel system, the receptor-mediated T-cell activation pathway, and the receptor-mediated activation of phospholipases. Those coupled to membrane depolarization or intracellular release of calcium include the receptor-mediated activation of cytotoxic functions in granulocytes and the synaptic potentiation of protein kinase activation. Some signal transduction pathways may be part of larger signal transduction pathways; for example, protein kinase activation is part of the platelet activation signal pathway.
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.
Nonionic surfactant mixtures varying in the number of repeating ethoxy (oxy-1,2-ethanediyl) groups. They are used as detergents, emulsifiers, wetting agents, defoaming agents, etc. Octoxynol-9, the compound with 9 repeating ethoxy groups, is a spermatocide.
Microscopy in which the samples are first stained immunocytochemically and then examined using an electron microscope. Immunoelectron microscopy is used extensively in diagnostic virology as part of very sensitive immunoassays.
Intracellular fluid from the cytoplasm after removal of ORGANELLES and other insoluble cytoplasmic components.
Cellular release of material within membrane-limited vesicles by fusion of the vesicles with the CELL MEMBRANE.
A subfamily in the family MURIDAE, comprising the hamsters. Four of the more common genera are Cricetus, CRICETULUS; MESOCRICETUS; and PHODOPUS.
The principal sterol of all higher animals, distributed in body tissues, especially the brain and spinal cord, and in animal fats and oils.
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.
Proteins prepared by recombinant DNA technology.
The degree of similarity between sequences of amino acids. This information is useful for the analyzing genetic relatedness of proteins and species.
The tendency of a gas or solute to pass from a point of higher pressure or concentration to a point of lower pressure or concentration and to distribute itself throughout the available space. Diffusion, especially FACILITATED DIFFUSION, is a major mechanism of BIOLOGICAL TRANSPORT.
Cytoplasmic vesicles formed when COATED VESICLES shed their CLATHRIN coat. Endosomes internalize macromolecules bound by receptors on the cell surface.
Identification of proteins or peptides that have been electrophoretically separated by blot transferring from the electrophoresis gel to strips of nitrocellulose paper, followed by labeling with antibody probes.
Derivatives of phosphatidic acids in which the phosphoric acid is bound in ester linkage to an ethanolamine moiety. Complete hydrolysis yields 1 mole of glycerol, phosphoric acid and ethanolamine and 2 moles of fatty acids.
Any spaces or cavities within a cell. They may function in digestion, storage, secretion, or excretion.
The insertion of recombinant DNA molecules from prokaryotic and/or eukaryotic sources into a replicating vehicle, such as a plasmid or virus vector, and the introduction of the resultant hybrid molecules into recipient cells without altering the viability of those cells.
Proteins obtained from ESCHERICHIA COLI.
Derivatives of phosphatidic acids in which the phosphoric acid is bound in ester linkage to a serine moiety. Complete hydrolysis yields 1 mole of glycerol, phosphoric acid and serine and 2 moles of fatty acids.
The uptake of naked or purified DNA by CELLS, usually meaning the process as it occurs in eukaryotic cells. It is analogous to bacterial transformation (TRANSFORMATION, BACTERIAL) and both are routinely employed in GENE TRANSFER TECHNIQUES.
Porins are protein molecules that were originally found in the outer membrane of GRAM-NEGATIVE BACTERIA and that form multi-meric channels for the passive DIFFUSION of WATER; IONS; or other small molecules. Porins are present in bacterial CELL WALLS, as well as in plant, fungal, mammalian and other vertebrate CELL MEMBRANES and MITOCHONDRIAL MEMBRANES.
The rate dynamics in chemical or physical systems.
Protein analogs and derivatives of the Aequorea victoria green fluorescent protein that emit light (FLUORESCENCE) when excited with ULTRAVIOLET RAYS. They are used in REPORTER GENES in doing GENETIC TECHNIQUES. Numerous mutants have been made to emit other colors or be sensitive to pH.
Artifactual vesicles formed from the endoplasmic reticulum when cells are disrupted. They are isolated by differential centrifugation and are composed of three structural features: rough vesicles, smooth vesicles, and ribosomes. Numerous enzyme activities are associated with the microsomal fraction. (Glick, Glossary of Biochemistry and Molecular Biology, 1990; from Rieger et al., Glossary of Genetics: Classical and Molecular, 5th ed)
Single membrane vesicles, generally made of PHOSPHOLIPIDS.
The study of the generation and behavior of electrical charges in living organisms particularly the nervous system and the effects of electricity on living organisms.
Measurement of the intensity and quality of fluorescence.
Immunologic method used for detecting or quantifying immunoreactive substances. The substance is identified by first immobilizing it by blotting onto a membrane and then tagging it with labeled antibodies.
Spontaneous tearing of the membranes surrounding the FETUS any time before the onset of OBSTETRIC LABOR. Preterm PROM is membrane rupture before 37 weeks of GESTATION.
Cell surface proteins that bind signalling molecules external to the cell with high affinity and convert this extracellular event into one or more intracellular signals that alter the behavior of the target cell (From Alberts, Molecular Biology of the Cell, 2nd ed, pp693-5). Cell surface receptors, unlike enzymes, do not chemically alter their ligands.
An oval semitransparent membrane separating the external EAR CANAL from the tympanic cavity (EAR, MIDDLE). It contains three layers: the skin of the external ear canal; the core of radially and circularly arranged collagen fibers; and the MUCOSA of the middle ear.
A layer of the cornea. It is the basal lamina of the CORNEAL ENDOTHELIUM (from which it is secreted) separating it from the CORNEAL STROMA. It is a homogeneous structure composed of fine collagenous filaments, and slowly increases in thickness with age.
Inorganic compounds derived from hydrochloric acid that contain the Cl- ion.
CELL LINES derived from the CV-1 cell line by transformation with a replication origin defective mutant of SV40 VIRUS, which codes for wild type large T antigen (ANTIGENS, POLYOMAVIRUS TRANSFORMING). They are used for transfection and cloning. (The CV-1 cell line was derived from the kidney of an adult male African green monkey (CERCOPITHECUS AETHIOPS).)
The network of filaments, tubules, and interconnecting filamentous bridges which give shape, structure, and organization to the cytoplasm.
The domestic dog, Canis familiaris, comprising about 400 breeds, of the carnivore family CANIDAE. They are worldwide in distribution and live in association with people. (Walker's Mammals of the World, 5th ed, p1065)
The first continuously cultured human malignant CELL LINE, derived from the cervical carcinoma of Henrietta Lacks. These cells are used for VIRUS CULTIVATION and antitumor drug screening assays.
Application of a life support system that circulates the blood through an oxygenating system, which may consist of a pump, a membrane oxygenator, and a heat exchanger. Examples of its use are to assist victims of smoke inhalation injury, respiratory failure, and cardiac failure.
Vesicles that are involved in shuttling cargo from the interior of the cell to the cell surface, from the cell surface to the interior, across the cell or around the cell to various locations.
A class of morphologically heterogeneous cytoplasmic particles in animal and plant tissues characterized by their content of hydrolytic enzymes and the structure-linked latency of these enzymes. The intracellular functions of lysosomes depend on their lytic potential. The single unit membrane of the lysosome acts as a barrier between the enzymes enclosed in the lysosome and the external substrate. The activity of the enzymes contained in lysosomes is limited or nil unless the vesicle in which they are enclosed is ruptured. Such rupture is supposed to be under metabolic (hormonal) control. (From Rieger et al., Glossary of Genetics: Classical and Molecular, 5th ed)
Amino acid sequences found in transported proteins that selectively guide the distribution of the proteins to specific cellular compartments.
The thermodynamic interaction between a substance and WATER.
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)
Any of various enzymatically catalyzed post-translational modifications of PEPTIDES or PROTEINS in the cell of origin. These modifications include carboxylation; HYDROXYLATION; ACETYLATION; PHOSPHORYLATION; METHYLATION; GLYCOSYLATION; ubiquitination; oxidation; proteolysis; and crosslinking and result in changes in molecular weight and electrophoretic motility.
A product of COMPLEMENT ACTIVATION cascade, regardless of the pathways, that forms transmembrane channels causing disruption of the target CELL MEMBRANE and cell lysis. It is formed by the sequential assembly of terminal complement components (COMPLEMENT C5B; COMPLEMENT C6; COMPLEMENT C7; COMPLEMENT C8; and COMPLEMENT C9) into the target membrane. The resultant C5b-8-poly-C9 is the "membrane attack complex" or MAC.
Conjugated protein-carbohydrate compounds including mucins, mucoid, and amyloid glycoproteins.
A replica technique in which cells are frozen to a very low temperature and cracked with a knife blade to expose the interior surfaces of the cells or cell membranes. The cracked cell surfaces are then freeze-dried to expose their constituents. The surfaces are now ready for shadowing to be viewed using an electron microscope. This method differs from freeze-fracturing in that no cryoprotectant is used and, thus, allows for the sublimation of water during the freeze-drying process to etch the surfaces.
Filamentous proteins that are the main constituent of the thin filaments of muscle fibers. The filaments (known also as filamentous or F-actin) can be dissociated into their globular subunits; each subunit is composed of a single polypeptide 375 amino acids long. This is known as globular or G-actin. In conjunction with MYOSINS, actin is responsible for the contraction and relaxation of muscle.
CELL LINE derived from the ovary of the Chinese hamster, Cricetulus griseus (CRICETULUS). The species is a favorite for cytogenetic studies because of its small chromosome number. The cell line has provided model systems for the study of genetic alterations in cultured mammalian cells.
The relationship between the chemical structure of a compound and its biological or pharmacological activity. Compounds are often classed together because they have structural characteristics in common including shape, size, stereochemical arrangement, and distribution of functional groups.
Ubiquitously expressed integral membrane glycoproteins found in the LYSOSOME.
Orientation of intracellular structures especially with respect to the apical and basolateral domains of the plasma membrane. Polarized cells must direct proteins from the Golgi apparatus to the appropriate domain since tight junctions prevent proteins from diffusing between the two domains.
Multisubunit enzymes that reversibly synthesize ADENOSINE TRIPHOSPHATE. They are coupled to the transport of protons across a membrane.
An electrophysiologic technique for studying cells, cell membranes, and occasionally isolated organelles. All patch-clamp methods rely on a very high-resistance seal between a micropipette and a membrane; the seal is usually attained by gentle suction. The four most common variants include on-cell patch, inside-out patch, outside-out patch, and whole-cell clamp. Patch-clamp methods are commonly used to voltage clamp, that is control the voltage across the membrane and measure current flow, but current-clamp methods, in which the current is controlled and the voltage is measured, are also used.
Conversion of an inactive form of an enzyme to one possessing metabolic activity. It includes 1, activation by ions (activators); 2, activation by cofactors (coenzymes); and 3, conversion of an enzyme precursor (proenzyme or zymogen) to an active enzyme.
The plasma membrane of the egg.
Calcium-transporting ATPases found on the PLASMA MEMBRANE that catalyze the active transport of CALCIUM from the CYTOPLASM into the extracellular space. They play a role in maintaining a CALCIUM gradient across plasma membrane.
The innermost membranous sac that surrounds and protects the developing embryo which is bathed in the AMNIOTIC FLUID. Amnion cells are secretory EPITHELIAL CELLS and contribute to the amniotic fluid.
Genetically identical individuals developed from brother and sister matings which have been carried out for twenty or more generations or by parent x offspring matings carried out with certain restrictions. This also includes animals with a long history of closed colony breeding.
Histochemical localization of immunoreactive substances using labeled antibodies as reagents.
A large lobed glandular organ in the abdomen of vertebrates that is responsible for detoxification, metabolism, synthesis and storage of various substances.
Proteins involved in the transport of specific substances across the membranes of the MITOCHONDRIA.
Separation of particles according to density by employing a gradient of varying densities. At equilibrium each particle settles in the gradient at a point equal to its density. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)
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)
Cyclic GLUCANS consisting of seven (7) glucopyranose units linked by 1,4-glycosidic bonds.
Regulatory proteins that act as molecular switches. They control a wide range of biological processes including: receptor signaling, intracellular signal transduction pathways, and protein synthesis. Their activity is regulated by factors that control their ability to bind to and hydrolyze GTP to GDP. EC 3.6.1.-.
An enzyme that catalyzes the active transport system of sodium and potassium ions across the cell wall. Sodium and potassium ions are closely coupled with membrane ATPase which undergoes phosphorylation and dephosphorylation, thereby providing energy for transport of these ions against concentration gradients.
Partial proteins formed by partial hydrolysis of complete proteins or generated through PROTEIN ENGINEERING techniques.
Body organ that filters blood for the secretion of URINE and that regulates ion concentrations.
The basic cellular units of nervous tissue. Each neuron consists of a body, an axon, and dendrites. Their purpose is to receive, conduct, and transmit impulses in the NERVOUS SYSTEM.
A strain of albino rat used widely for experimental purposes because of its calmness and ease of handling. It was developed by the Sprague-Dawley Animal Company.
Cells that line the inner and outer surfaces of the body by forming cellular layers (EPITHELIUM) or masses. Epithelial cells lining the SKIN; the MOUTH; the NOSE; and the ANAL CANAL derive from ectoderm; those lining the RESPIRATORY SYSTEM and the DIGESTIVE SYSTEM derive from endoderm; others (CARDIOVASCULAR SYSTEM and LYMPHATIC SYSTEM) derive from mesoderm. Epithelial cells can be classified mainly by cell shape and function into squamous, glandular and transitional epithelial cells.
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.
Proteins obtained from the species SACCHAROMYCES CEREVISIAE. The function of specific proteins from this organism are the subject of intense scientific interest and have been used to derive basic understanding of the functioning similar proteins in higher eukaryotes.
Specific particles of membrane-bound organized living substances present in eukaryotic cells, such as the MITOCHONDRIA; the GOLGI APPARATUS; ENDOPLASMIC RETICULUM; LYSOSOMES; PLASTIDS; and VACUOLES.
The membrane system of the CELL NUCLEUS that surrounds the nucleoplasm. It consists of two concentric membranes separated by the perinuclear space. The structures of the envelope where it opens to the cytoplasm are called the nuclear pores (NUCLEAR PORE).
The relationship between the dose of an administered drug and the response of the organism to the drug.
A species of CERCOPITHECUS containing three subspecies: C. tantalus, C. pygerythrus, and C. sabeus. They are found in the forests and savannah of Africa. The African green monkey (C. pygerythrus) is the natural host of SIMIAN IMMUNODEFICIENCY VIRUS and is used in AIDS research.
A high molecular weight (220-250 kDa) water-soluble protein which can be extracted from erythrocyte ghosts in low ionic strength buffers. The protein contains no lipids or carbohydrates, is the predominant species of peripheral erythrocyte membrane proteins, and exists as a fibrous coating on the inner, cytoplasmic surface of the membrane.
A common name used for the genus Cavia. The most common species is Cavia porcellus which is the domesticated guinea pig used for pets and biomedical research.
Electron microscopy in which the ELECTRONS or their reaction products that pass down through the specimen are imaged below the plane of the specimen.
A basement membrane in the cochlea that supports the hair cells of the ORGAN OF CORTI, consisting keratin-like fibrils. It stretches from the SPIRAL LAMINA to the basilar crest. The movement of fluid in the cochlea, induced by sound, causes displacement of the basilar membrane and subsequent stimulation of the attached hair cells which transform the mechanical signal into neural activity.
One or more layers of EPITHELIAL CELLS, supported by the basal lamina, which covers the inner or outer surfaces of the body.
A cyclododecadepsipeptide ionophore antibiotic produced by Streptomyces fulvissimus and related to the enniatins. It is composed of 3 moles each of L-valine, D-alpha-hydroxyisovaleric acid, D-valine, and L-lactic acid linked alternately to form a 36-membered ring. (From Merck Index, 11th ed) Valinomycin is a potassium selective ionophore and is commonly used as a tool in biochemical studies.
A class of sphingolipids found largely in the brain and other nervous tissue. They contain phosphocholine or phosphoethanolamine as their polar head group so therefore are the only sphingolipids classified as PHOSPHOLIPIDS.
Proteins which are involved in the phenomenon of light emission in living systems. Included are the "enzymatic" and "non-enzymatic" types of system with or without the presence of oxygen or co-factors.
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.
Condensed areas of cellular material that may be bounded by a membrane.
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.
RNA sequences that serve as templates for protein synthesis. Bacterial mRNAs are generally primary transcripts in that they do not require post-transcriptional processing. Eukaryotic mRNA is synthesized in the nucleus and must be exported to the cytoplasm for translation. Most eukaryotic mRNAs have a sequence of polyadenylic acid at the 3' end, referred to as the poly(A) tail. The function of this tail is not known for certain, but it may play a role in the export of mature mRNA from the nucleus as well as in helping stabilize some mRNA molecules by retarding their degradation in the cytoplasm.
Antibodies produced by a single clone of cells.
The characteristic three-dimensional shape of a molecule.
A metallic element that has the atomic symbol Mg, atomic number 12, and atomic weight 24.31. It is important for the activity of many enzymes, especially those involved in OXIDATIVE PHOSPHORYLATION.
The interaction of two or more substrates or ligands with the same binding site. The displacement of one by the other is used in quantitative and selective affinity measurements.
Cell membrane glycoproteins that are selectively permeable to potassium ions. At least eight major groups of K channels exist and they are made up of dozens of different subunits.
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.
Derivatives of phosphatidic acids in which the phosphoric acid is bound in ester linkage to the hexahydroxy alcohol, myo-inositol. Complete hydrolysis yields 1 mole of glycerol, phosphoric acid, myo-inositol, and 2 moles of fatty acids.
Surface glycoproteins on platelets which have a key role in hemostasis and thrombosis such as platelet adhesion and aggregation. Many of these are receptors.
The arrangement of two or more amino acid or base sequences from an organism or organisms in such a way as to align areas of the sequences sharing common properties. The degree of relatedness or homology between the sequences is predicted computationally or statistically based on weights assigned to the elements aligned between the sequences. This in turn can serve as a potential indicator of the genetic relatedness between the organisms.
Stable elementary particles having the smallest known positive charge, found in the nuclei of all elements. The proton mass is less than that of a neutron. A proton is the nucleus of the light hydrogen atom, i.e., the hydrogen ion.
Genetically engineered MUTAGENESIS at a specific site in the DNA molecule that introduces a base substitution, or an insertion or deletion.
Negatively charged atoms, radicals or groups of atoms which travel to the anode or positive pole during electrolysis.
The deductive study of shape, quantity, and dependence. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)
Measurement of the polarization of fluorescent light from solutions or microscopic specimens. It is used to provide information concerning molecular size, shape, and conformation, molecular anisotropy, electronic energy transfer, molecular interaction, including dye and coenzyme binding, and the antigen-antibody reaction.
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.
A major integral transmembrane protein of the ERYTHROCYTE MEMBRANE. It is the anion exchanger responsible for electroneutral transporting in CHLORIDE IONS in exchange of BICARBONATE IONS allowing CO2 uptake and transport from tissues to lungs by the red blood cells. Genetic mutations that result in a loss of the protein function have been associated with type 4 HEREDITARY SPHEROCYTOSIS.
The concentration of osmotically active particles in solution expressed in terms of osmoles of solute per liter of solution. Osmolality is expressed in terms of osmoles of solute per kilogram of solvent.
Compounds containing carbohydrate or glycosyl groups linked to phosphatidylinositols. They anchor GPI-LINKED PROTEINS or polysaccharides to cell membranes.
Particles consisting of aggregates of molecules held loosely together by secondary bonds. The surface of micelles are usually comprised of amphiphatic compounds that are oriented in a way that minimizes the energy of interaction between the micelle and its environment. Liquids that contain large numbers of suspended micelles are referred to as EMULSIONS.
Membrane-limited structures derived from the plasma membrane or various intracellular membranes which function in storage, transport or metabolism.
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 serine endopeptidase that is formed from TRYPSINOGEN in the pancreas. It is converted into its active form by ENTEROPEPTIDASE in the small intestine. It catalyzes hydrolysis of the carboxyl group of either arginine or lysine. EC 3.4.21.4.
Abrupt changes in the membrane potential that sweep along the CELL MEMBRANE of excitable cells in response to excitation stimuli.
A fluorescent compound that emits light only in specific configurations in certain lipid media. It is used as a tool in the study of membrane lipids.
A fungal metabolite which is a macrocyclic lactone exhibiting a wide range of antibiotic activity.
Organic, monobasic acids derived from hydrocarbons by the equivalent of oxidation of a methyl group to an alcohol, aldehyde, and then acid. Fatty acids are saturated and unsaturated (FATTY ACIDS, UNSATURATED). (Grant & Hackh's Chemical Dictionary, 5th ed)
The movement of ions across energy-transducing cell membranes. Transport can be active, passive or facilitated. Ions may travel by themselves (uniport), or as a group of two or more ions in the same (symport) or opposite (antiport) directions.
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)
Tendency of fluids (e.g., water) to move from the less concentrated to the more concentrated side of a semipermeable membrane.
Immunoglobulin molecules having a specific amino acid sequence by virtue of which they interact only with the ANTIGEN (or a very similar shape) that induced their synthesis in cells of the lymphoid series (especially PLASMA CELLS).
The destruction of ERYTHROCYTES by many different causal agents such as antibodies, bacteria, chemicals, temperature, and changes in tonicity.
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.
Positively charged atoms, radicals or groups of atoms which travel to the cathode or negative pole during electrolysis.
A phosphoinositide present in all eukaryotic cells, particularly in the plasma membrane. It is the major substrate for receptor-stimulated phosphoinositidase C, with the consequent formation of inositol 1,4,5-triphosphate and diacylglycerol, and probably also for receptor-stimulated inositol phospholipid 3-kinase. (Kendrew, The Encyclopedia of Molecular Biology, 1994)
The chemical or biochemical addition of carbohydrate or glycosyl groups to other chemicals, especially peptides or proteins. Glycosyl transferases are used in this biochemical reaction.
The process of cleaving a chemical compound by the addition of a molecule of water.
A tyrosine phosphoprotein that plays an essential role in CAVEOLAE formation. It binds CHOLESTEROL and is involved in LIPIDS transport, membrane traffic, and SIGNAL TRANSDUCTION.
A class of porins that allow the passage of WATER and other small molecules across CELL MEMBRANES.
Membranous cisternae of the CHLOROPLAST containing photosynthetic pigments, reaction centers, and the electron-transport chain. Each thylakoid consists of a flattened sac of membrane enclosing a narrow intra-thylakoid space (Lackie and Dow, Dictionary of Cell Biology, 2nd ed). Individual thylakoids are interconnected and tend to stack to form aggregates called grana. They are found in cyanobacteria and all plants.

Relocating the active site of activated protein C eliminates the need for its protein S cofactor. A fluorescence resonance energy transfer study. (1/2869)

The effect of replacing the gamma-carboxyglutamic acid domain of activated protein C (APC) with that of prothrombin on the topography of the membrane-bound enzyme was examined using fluorescence resonance energy transfer. The average distance of closest approach (assuming kappa2 = 2/3) between a fluorescein in the active site of the chimera and octadecylrhodamine at the membrane surface was 89 A, compared with 94 A for wild-type APC. The gamma-carboxyglutamic acid domain substitution therefore lowered and/or reoriented the active site, repositioning it close to the 84 A observed for the APC. protein S complex. Protein S enhances wild-type APC cleavage of factor Va at Arg306, but the inactivation rate of factor Va Leiden by the chimera alone is essentially equal to that by wild-type APC plus protein S. These data suggest that the activities of the chimera and of the APC.protein S complex are equivalent because the active site of the chimeric protein is already positioned near the optimal location above the membrane surface to cleave Arg306. Thus, one mechanism by which protein S regulates APC activity is by relocating its active site to the proper position above the membrane surface to optimize factor Va cleavage.  (+info)

Activation of the kallikrein-kinin system in hemodialysis: role of membrane electronegativity, blood dilution, and pH. (2/2869)

BACKGROUND: The kallikrein-kinin system activation by contact with a negatively charged surface has been promulgated to be responsible for hypersensitivity reactions. However, to explain the low frequency and heterogeneity of hypersensitivity reactions, we hypothesized that not only the electronegativity of the membrane, but also other physicochemical parameters could influence the activation of the contact phase system of plasma assessed by the measurement of kallikrein activity and bradykinin concentration. METHODS: Plasma kallikrein activity using chromogenic substrate (S2302) and plasma bradykinin concentration (enzyme immuno assay) were measured during the perfusion of human plasma (2.5 ml/min) through minidialyzers mounted with six different membranes [polyacrylonitrile (PAN) from Asahi (PANDX) and from Hospal (AN69), polymethylmethacrylate (PMMA) from Toray, cellulose triacetate (CT) from Baxter, cuprophane (CUP) from Akzo and polysulfone (PS) from Fresenius]. RESULTS: A direct relationship was shown between the electronegativity of the membrane assessed by its zeta potential and the activation of plasma during the first five minutes of plasma circulation. With the AN69 membrane, the detection of a kallikrein activity in diluted plasma but not in undiluted samples confirmed the importance of a protease-antiprotease imbalance leading to bradykinin release during the first five minutes of dialysis. With PAN membranes, the use of citrated versus heparinized plasma and the use of various rinsing solutions clearly show a dramatic effect of pH on the kallikrein activity and the bradykinin concentration measured in plasma. Finally, increasing the zeta potential of the membrane leads to a significant increase of plasma kallikrein activity and bradykinin concentration. CONCLUSIONS: Our in vitro experimental approach evidences the importance of the control of these physicochemical factors to decrease the activation of the contact system.  (+info)

Three-independent-compartment chamber to study in vitro commissural synapses. (3/2869)

We describe a novel chamber in which the two intact neonatal rat hippocampi and the commissural fibers are placed in three independent compartments separated by latex membranes and perfused selectively with different solutions. A set of control tests showed that the compartments are well isolated: 1) methylene blue or eosin applied to one compartment did not diffuse to other compartments when verified via the microscope, and spectrophotometry revealed that <1/10.000th of the dye diffuses to other compartments; 2) tetrodotoxin (1 microM) applied to the commissural compartment blocked the synaptic responses evoked contralaterally without affecting those evoked on the ipsilateral side. This chamber enables a wide range of experiments that cannot be performed in conventional chambers, e.g., to study the maturation and plasticity of the commissural connections, bilateral synchronization of the rhythmic activities in the limbic system, commissural propagation of the epileptiform activities, etc.  (+info)

Electrostatic interactions during activation of coagulation factor IX via the tissue factor pathway: effect of univalent salts. (4/2869)

Interaction between the Gla-domain of coagulation proteins and negatively charged phospholipid membranes is essential for blood coagulation reactions. The interaction is calcium-dependent and mediated both by electrostatic and hydrophobic forces. This report focuses on the electrostatic component of factor IX activation via the extrinsic pathway. Effective charges during the reaction are measured by ionic titration of activity, according to the Debye-Huckel and Gouy-Chapman models. Rates of activation decrease with ionic strength independently of the type of monovalent salt used to control ionic strength. Moreover, the effect of ionic strength decreases at concentrations of charged phospholipid approaching saturation levels, indicating that membrane charges participate directly in the ionic interaction measured. The effective charge on calcium-bound factor IX during activation on phospholipid membranes is 0.95+/-0.1. Possible sites mediating contacts between the Gla-domain and membranes are selected by geometrical criteria in several metal-bound Gla-domain structures. A pocket with a solvent opening-pore of area 24-38 A2 is found in the Gla-domain of factors IX, VII, and prothrombin. The pocket contains atoms with negative partial charges, including carboxylate oxygens from Gla residues, and has a volume of 57-114 A3, sufficient to accommodate additional calcium atoms. These studies demonstrate that electrostatic forces modify the activity coefficient of factor IX during functional interactions and suggest a conserved pocket motif as the contact site between the calcium-bound Gla-domain and charged membranes.  (+info)

Reconstitution of the human endothelial cell protein C receptor with thrombomodulin in phosphatidylcholine vesicles enhances protein C activation. (5/2869)

Blocking protein C binding to the endothelial cell protein C receptor (EPCR) on the endothelium is known to reduce protein C activation rates. Now we isolate human EPCR and thrombomodulin (TM) and reconstitute them into phosphatidylcholine vesicles. The EPCR increases protein C activation rates in a concentration-dependent fashion that does not saturate at 14 EPCR molecules/TM. Without EPCR, the protein C concentration dependence fits a single class of sites (Km = 2.17 +/- 0.13 microM). With EPCR, two classes of sites are apparent (Km = 20 +/- 15 nM and Km = 3.2 +/- 1.7 microM). Increasing the EPCR concentration at a constant TM concentration increases the percentage of high affinity sites. Holding the TM:EPCR ratio constant while decreasing the density of these proteins results in a decrease in the EPCR enhancement of protein C activation, suggesting that there is little affinity of the EPCR for TM. Negatively charged phospholipids also enhance protein C activation. EPCR acceleration of protein C activation is blocked by anti-EPCR antibodies, but not by annexin V, whereas the reverse is true with negatively charged phospholipids. Human umbilical cord endothelium expresses approximately 7 times more EPCR than TM. Anti-EPCR antibody reduces protein C activation rates 7-fold over these cells, whereas annexin V is ineffective, indicating that EPCR rather than negatively charged phospholipid provide the surface for protein C activation. EPCR expression varies dramatically among vascular beds. The present results indicate that the EPCR concentration will determine the effectiveness of the protein C activation complex.  (+info)

Phospholipid-subclass-specific partitioning of lipophilic ions in membrane-water systems. (6/2869)

Herein, we systematically investigate phospholipid-subclass-specific alterations in the partitioning of both cationic and anionic amphiphiles to identify the importance of ester, ether and vinyl ether linkages at the sn-1 position of phospholipids in the partitioning of charged amphiphiles. The results demonstrated that the membrane-water partition coefficient of a prototypic cationic amphiphile (i.e. 3,3'-dipropylthiadicarbocyanine iodide) was approximately 2.5 times higher in membranes comprised of plasmenylcholine in comparison with membranes comprised of either phosphatidylcholine or plasmanylcholine. In striking contrast, the membrane-water partition coefficient of a prototypic anionic amphiphile [i.e. bis-(1,3-dibutylbarbituric acid)trimethine oxonol] in membranes comprised of plasmenylcholine was approximately 2.5 times lower than that manifest in membranes comprised of phosphatidylcholine or plasmanylcholine. Utilizing theseexperimentally determined partition coefficients,the relative membrane dipole potential of membranes comprised of plasmenylcholine was calculated and found to be approximately 25 mV lower than in membranes comprised of phosphatidylcholine or plasmanylcholine. This lower membrane dipole potential in membranes comprised of plasmenylcholine is equivalent to the membrane potential induced by incorporation of approximately 25 mol% of anionic phospholipids in membranes comprised of phosphatidylcholine. Collectively, these results demonstrate that phospholipid-subclass-specific differences in the membrane dipole potential contribute to alterations in the partitioning of lipophilic ions in membrane bilayers comprised of distinct phospholipid subclasses. Moreover, they suggest that these physicochemical differences can be exploited to facilitate the targeting of charged lipophilic drugs to specific cells and subcellular membrane compartments.  (+info)

Analysis of the membrane-interacting domains of myelin basic protein by hydrophobic photolabeling. (7/2869)

Myelin basic protein is a water soluble membrane protein which interacts with acidic lipids through some type of hydrophobic interaction in addition to electrostatic interactions. Here we show that it can be labeled from within the lipid bilayer when bound to acidic lipids with the hydrophobic photolabel 3-(trifluoromethyl)-3-(m-[125I]iodophenyl)diazirine (TID) and by two lipid photolabels. The latter included one with the reactive group near the apolar/polar interface and one with the reactive group linked to an acyl chain to position it deeper in the bilayer. The regions of the protein which interact hydrophobically with lipid to the greatest extent were determined by cleaving the TID-labeled myelin basic protein (MBP) with cathepsin D into peptides 1-43, 44-89, and 90-170. All three peptides from lipid-bound protein were labeled much more than peptides from the protein labeled in solution. However, the peptide labeling pattern was similar for both environments. The two peptides in the N-terminal half were labeled similarly and about twice as much as the C-terminal peptide indicating that the N-terminal half interacts hydrophobically with lipid more than the C-terminal half. MBP can be modified post-translationally in vivo, including by deamidation, which may alter its interactions with lipid. However, deamidation had no effect on the TID labeling of MBP or on the labeling pattern of the cathepsin D peptides. The site of deamidation has been reported to be in the C-terminal half, and its lack of effect on hydrophobic interactions of MBP with lipid are consistent with the conclusion that the N-terminal half interacts hydrophobically more than the C-terminal half. Since other studies of the interaction of isolated N-terminal and C-terminal peptides with lipid also indicate that the N-terminal half interacts hydrophobically with lipid more than the C-terminal half, these results from photolabeling of the intact protein suggest that the N-terminal half of the intact protein interacts with lipid in a similar way as the isolated peptide. The similar behavior of the intact protein to that of its isolated peptides suggests that when the purified protein binds to acidic lipids, it is in a conformation which allows both halves of the protein to interact independently with the lipid bilayer. That is, it does not form a hydrophobic domain made up from different parts of the protein.  (+info)

Scanning near-field fluorescence resonance energy transfer microscopy. (8/2869)

A new microscopic technique is demonstrated that combines attributes from both near-field scanning optical microscopy (NSOM) and fluorescence resonance energy transfer (FRET). The method relies on attaching the acceptor dye of a FRET pair to the end of a near-field fiber optic probe. Light exiting the NSOM probe, which is nonresonant with the acceptor dye, excites the donor dye introduced into a sample. As the tip approaches the sample containing the donor dye, energy transfer from the excited donor to the tip-bound acceptor produces a red-shifted fluorescence. By monitoring this red-shifted acceptor emission, a dramatic reduction in the sample volume probed by the uncoated NSOM tip is observed. This technique is demonstrated by imaging the fluorescence from a multilayer film created using the Langmuir-Blodgett (LB) technique. The film consists of L-alpha-dipalmitoylphosphatidylcholine (DPPC) monolayers containing the donor dye, fluorescein, separated by a spacer group of three arachidic acid layers. A DPPC monolayer containing the acceptor dye, rhodamine, was also transferred onto an NSOM tip using the LB technique. Using this modified probe, fluorescence images of the multilayer film reveal distinct differences between images collected monitoring either the donor or acceptor emission. The latter results from energy transfer from the sample to the NSOM probe. This method is shown to provide enhanced depth sensitivity in fluorescence measurements, which may be particularly informative in studies on thick specimens such as cells. The technique also provides a mechanism for obtaining high spatial resolution without the need for a metal coating around the NSOM probe and should work equally well with nonwaveguide probes such as atomic force microscopy tips. This may lead to dramatically improved spatial resolution in fluorescence imaging.  (+info)

TY - JOUR. T1 - Membrane properties for permeability testing. T2 - Skin versus synthetic membranes. AU - Haq, Anika. AU - Dorrani, Mania. AU - Goodyear, Benjamin. AU - Joshi, Vivek. AU - Michniak-Kohn, Bozena. PY - 2018/3/25. Y1 - 2018/3/25. N2 - Synthetic membranes that are utilized in diffusion studies for topical and transdermal formulations are usually porous thin polymeric sheets for example cellulose acetate (CA) and polysulfones. In this study, the permeability of human skin was compared using two synthetic membranes: cellulose acetate and Strat-M® membrane and lipophilic and hydrophilic compounds either as saturated or formulated solutions as well as marketed dosage forms. Our data suggests that hydrophilic compounds have higher permeation in Strat-M membranes compared with lipophilic ones. High variation in permeability values, a typical property of biological membranes, was not observed with Strat-M. In addition, the permeability of Strat-M was closer to that of human skin than that ...
The present invention generally relates to the field of pharmaceutical sciences. More specifically, the present invention includes apparatus and devices for the preparation of pharmaceutical formulations containing large diameter synthetic membrane vesicles, such as multivesicular liposomes, methods for preparing such formulations, and the use of specific formulations for therapeutic treatment of subjects in need thereof. Formation and use of the pharmaceutical formulations containing large diameter synthetic membrane vesicles produced by using the apparatus and devices for therapeutic treatment of subjects in need thereof is also contemplated.
A semipermeable membrane is a type of biological or synthetic, polymeric membrane that will allow certain molecules or ions to pass through it by diffusion-or occasionally by more specialized processes of facilitated diffusion, passive transport or active transport.[dubious - discuss] The rate of passage depends on the pressure, concentration, and temperature of the molecules or solutes on either side, as well as the permeability of the membrane to each solute. Depending on the membrane and the solute, permeability may depend on solute size, solubility, properties, or chemistry. How the membrane is constructed to be selective in its permeability will determine the rate and the permeability. Many natural and synthetic materials thicker than a membrane are also semipermeable. One example of this is the thin film on the inside of the egg. Note that a semipermeable membrane is not the same as a selectively permeable membrane. Semipermeable membrane describes a membrane that allows some particles to ...
Using Creative Bioarrays ADME screening services is the fastest and most cost-effective way to get permeability predictions for your compounds.
TY - JOUR. T1 - Reduction in beta2-microglobulin with super-flux versus high-flux dialysis membranes: Results of a 6-week, randomized, double-blind, crossover trial. AU - Pellicano, Rebecca. AU - Polkinghorne, Kevan R. AU - Kerr, Peter. PY - 2008. Y1 - 2008. N2 - Background: Uremic toxicity is a major concern in the dialysis population. There is keen interest in techniques that increase the removal of larger uremic molecules. We examined the short-term impact of a new, more porous, super-flux Helixone membrane (FX-E) versus the conventional high-flux Helixone. AB - Background: Uremic toxicity is a major concern in the dialysis population. There is keen interest in techniques that increase the removal of larger uremic molecules. We examined the short-term impact of a new, more porous, super-flux Helixone membrane (FX-E) versus the conventional high-flux Helixone. UR - http://www.sciencedirect.com/science/article/pii/S0272638608004666. M3 - Article. VL - 52. SP - 93. EP - 101. JO - American ...
Research Report on Global Synthetic Membranes Market Professional Survey Report 2017. The Report includes market price, demand, trends, size, Share, Growth, Forecast, Analysis & Overview.
Summary of Facts and Submissions. I. The appeal lies from the decision of the Opposition Division to reject the opposition against European patent 1 962 993.. II. The patent in suit comprises 11 claims, independent Claims 1, 10 and 11 reading as follows:. 1. An apparatus for analyzing a fluidic sample by microdialysis, comprising. a permeable membrane (100);. wherein the permeable membrane has a first surface (200) to be brought in contact with the fluidic sample to traverse the permeable membrane;. wherein the permeable membrane has a second surface (104) to be brought in contact with a dialysis fluid;. wherein the first surface is smoother than the second surface so that a surface roughness of the first surface is smaller than a surface roughness of the second surface;. wherein the permeable membrane comprises a hollow tube, an outer surface of the hollow tube forming the first surface;. wherein the permeable membrane comprises pores having a mean size which increases from the first surface ...
BISAC: SCI017000. This book presents an overview of membrane organization and lipid rafts in the cell and artificial membranes. The topics analyzed in this book cover a broad spectrum of functions played by lipid rafts in membrane organization within the cell and artificial membranes, and presents new information in this area of research. The topics analyzed include: fluid-mosaic cell membrane structure from cellular control and domains to extracellular vesicles; lipid rafts in binary lipid/cholesterol membranes; membrane assembly and lipid rafts in the cell and artificial membranes; the effect of lipid peroxidation; drugs, delivery systems and membrane organization in model and cell membranes; role of sphingomyelin on membrane domain formation and its influence in protein interaction focusing on the nanometer scale; lipid rafts and cell adhesion; mutual modulators of cell signaling; and finally, roles of glycosphingolipids in the regulation of the membrane organization and cell signaling in ...
A gas permeable membrane divides a reactor vessel into a liquid compartment and a gas compartment. A biofilm is grown on the gas permeable membrane on the liquid side of the membrane. Teh gas permeable membrane is supported by the structure of the membrane itself. The biofilm is chosen from bacteria to degrade cetain pollutants by means of anaerobic fermentation, aerobic heterotrophic oxidation, dehalogenation, and hydrocarbon oxidation. This is accomplished by means of oxygen and alternate gases (i.e., methane) through the gas permeable membrane to certain bacteria growing on the liquid side of the gas permeable membrane.
Diffusion is the net movement of particles of a gas or a solute from an area of high concentration to an area of low concentration along a ocncentration gradient through a partially permeable membrane.. Partially permeable - allowing only certain substances to pass through .. Partially permeable membrane - a membrane which only allows certain substances to pass through.. Osmosis - the net movemetn of water particles from an area of high concentration (of water NOT solute) to an area of low concentration (of water NOT solute) along a concentration gradient through a partially permeable membrane.. In diffusion, the partially permeable membrane only allows gas particles or particles of a solute to go through.. In osmosis, the partially permeable membrane only allows water particles to go through.. The concentration outside your cells need to stay the same for them to work properly. Changes in the concentration of solutions outside the cells may cause water to move into or out of the cells by ...
The effect of the amount of pore generating agent (polyvinylpyrrolidone) added to standard polymer membranes containing 18 wt.% of polyethersulfone on the physicochemical properties of the membranes and their capacity for removal of iron and copper ions from the liquid phase was studied. The membranes were obtained by the phase inversion method. The results have shown that the modification of polymer membranes by the use of different amounts of the pore forming agent in their syntheses leads to significant changes in porosity and has beneficial effect on equilibrium water content. The membranes studied were found to show different acid-base surface character, but for all membranes studied, a significant dominance of oxygen groups of acidic character was evidenced. The most effective were the membranes of the lowest content of polyvinylpyrrolidone, while the lowest values of resistance showed the membranes of the highest content of PVP, and so the ones of the greatest porosity.
TY - JOUR. T1 - Removal of lipopolysaccharide and reactive Oxygen species using sialic acid immobilized polysulfone dialyzer. AU - Chang, Jung Jhih. AU - Lin, Po Jub. AU - Yang, Ming Chien. AU - Chien, Chiang-Ting. PY - 2009/12/1. Y1 - 2009/12/1. N2 - Sialic acid (N-acetylneuraminic acid, NANA) was covalently immobilized onto the surface of a polysulfone (PSF) hollow fiber membrane. Prior to the immobilization, the surface of PSF was treated with ozone, followed by grafting with acrylic acid, and then the esterification of NANA. The surface concentration of NANA was determined by 2-thiobarbituric acid (TBA) test. Hemocompatibility, the capability of suppressing oxidative stress, and clearance of lipopolysaccharide (LPS) from the resulting hollow fiber membrane were evaluated. The results show that by immobilizing NANA onto PSF hollow fiber, the adhesion of platelet was reduced, while both APTT and PT were little affected. Furthermore, oxidative stress was suppressed by NANA-immobilized PSF ...
Polymer membranes have become a leading contender in numerous separation processes. Be it in gas (air, hydrogen etc.) or be it in water purifications (salinated water, waste water etc.). Not only polymer membrane technology helps reducing the environmental impact but also it is cost-effective. Fracking in shell gas is one of many examples. New advances in drilling technology (such as horizontal drilling) have led to new hydraulic fractures called fracking. Hydraulic fracturing requires about 2.5 to 5 million gallons of water per well. Water management and its disposal are major costs for producers.
A method of treating a membrane comprises the steps of providing a membrane with surfaces that define a plurality of pores extending through the membrane. Providing a dispersion of oleophobic fluoropolymer solids. Stabilizing the dispersion with a stabilizing agent. Diluting the dispersion with a wetting agent. Wetting surfaces which define the pores in the membrane with the diluted and stabilized dispersion. Removing the wetting agent and the stabilizing agent from the membrane. Coalescing the oleophobic fluoropolymer solids of the dispersion on surfaces that define pores in the membrane. A composite membrane comprises a porous membrane having a plurality of interconnecting pores extending through the membrane and made from a material which tends to absorb oils and certain contaminating surfactants. A coating is disposed on surfaces of the nodes and fibrils defining the interconnecting passages in the membrane. The coating comprises oleophobic fluoropolymer solids coalesced on surfaces of the nodes and
View Notes - lab report 4 jennifer jacob from ENG 240 at Ocean County College. through a selectively permeable membrane? Explain your answer. Size and solubility determine whether molecules pass
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The sugar part of our biomembranes are as crucial to our health as our DNA, and yet we know almost nothing about it, said Virgil Percec, a professor of chemistry in the University of Pennsylvania School of Arts and Sciences.. Part of the reason cell membrane sugars, called glycans, are so poorly understood is that scientists were unable to accurately model them until last year, when Percecs lab devised a way of programming artificial membranes with a precise number and spatial arrangement of sugars.. Now, as a proof-of-concept for their new model, the team has tested its interactions with galectin-8, a cell signaling protein that, when mutated, may contribute to rheumatoid arthritis. Gal-8 is one of a large family of growth-regulatory proteins the team is testing their model against. By modifying a single building block in Gal-8s structure, exactly as nature does in a portion of the population, the researchers dramatically impaired its ability to communicate with the artificial membrane, ...
The oxygen concentration in the culture medium can be measured electrochemically and continuously for at least 24 hours. Gold is the choice of working electrode because it is a stable and inert material to electrochemically reduce oxygen. Gold wire encased in epoxy is the working electrode. It has a fine opening at one end exposing the cross-section of the gold wire to the electrolyte. The opening is protected by an oxygen permeable membrane resistant to cell attachment and protein aggregation. PTFE and cellulose membrane (dialysis membrane) will be investigated for their applicability to the current set-up. PTFE is cheap, hydrophobic and oxygen permeable while dialysis membrane have different pore sizes to give different diffusivity for different sizes of molecules. The selectively permeable membrane is held at the opening with an O-ring encapsulating a small volume of electrolyte. A silver rod is the reference electrode placed in proximity to the working electrode. The current generated by ...
Free Online Library: Preparation and characterization of symmetric and asymmetric pure polysulfone membranes for C[O.sub.2] and C[H.sub.4] separation.(Report) by Polymer Engineering and Science; Engineering and manufacturing Science and technology, general Carbon dioxide Chemical properties Identification and classification Chemical synthesis Methods Health maintenance organizations Membranes (Technology) Composition Production processes Methane Permeability Polymers Polysulfone Usage Polysulphones
Material such as biological material is encapsulated within a semi-permeable hybrid membrane bead by suspending the material in a medium which comprises an effective amount of a gelling inducer; forming said suspension into a droplet of a size sufficient to envelop said material, suspending a second material in a gelling solution comprising an effective amount of a gel forming polymer which gels upon contact with said gelling inducer forming a discrete bead by contacting the outer surface portion of the droplet with a gelling solution, and allowing the gelling solution to thicken sufficiently for the second material to become entrapped therein.
Health, ...As reported in the journal Science physicists at the Technisch...Over the past three decades researchers have advanced DNA nanotechnol...To wall off the insides of cells from the outside world organisms in ...,Researchers,build,synthetic,membrane,channels,out,of,DNA,medicine,medical news today,latest medical news,medical newsletters,current medical news,latest medicine news
A membrane-based assay device for detecting the presence or quantity of an analyte residing in a test sample is provided. The device utilizes time-resolved fluorescence to detect the signals generated by excited fluorescent labels. Because the labels can have relatively long emission lifetime, short-lived background interference can be practically eliminated through delayed fluorescence detection. In addition, the resulting fluorescent reader can have a simple and inexpensive design. For instance, in one embodiment, the reader can utilize a silicon photodiode and a pulsed light-emitting diode (LED) to accurately excite labels and detect fluorescence on a membrane-based assay device without requiring the use of expensive components, such as monochromators or narrow emission band width optical filters.
Schematic illustration of the channel formed by 54 double-helical DNA domains packed on a honeycomb lattice. Cylinders indicate double-helical DNA domains.
Video created by École Polytechnique Fédérale de Lausanne for the course Introduction to Household Water Treatment and Safe Storage. During week 2 and 3 we focus on potential treatment methods. We refer first to the standards of safe drinking ...
The Semipermeable Membrane: Phospholipid Bilayer. Monday November 22, 2010. In your Notebook. Remember: Water is a polar molecule. Like Attracts Like. Warmup. Pass in Lab Reports Watch the demonstration. 1. Explain how water is interacting with the magic sand and clear spheres. Slideshow 6719343 by wang-avery
Spectrum™ Spectra/Por™ 1 RC Dialysis Membrane Tubing 6000 to 8000 Dalton MWCO Flat width: 10mm Spectrum™ Spectra/Por™ 1 RC Dialysis Membrane...
[126 Pages Report] Check for Discount on Global Dialysis Membranes Sales Market Report 2021 report by QYResearch Group. The global Dialysis Membranes market is segmented by company, region (...
Synonyms for collagen membrane in Free Thesaurus. Antonyms for collagen membrane. 11 synonyms for membrane: layer, film, skin, tissue, veil, diaphragm, lamina, sheath, sheathing, skin, tissue layer. What are synonyms for collagen membrane?
Many futurists envision a world in which polymer membranes with molecular-sized channels are used to capture carbon, produce solar-based fuels, or desalinate sea water, among many other functions. This will require methods by which such membranes can be readily fabricated in bulk quantities. A technique representing a significant first step down that road has now been successfully demonstrated.
Nitrate Ion Selective Combination Electrode, Polymer Membrane, Beckman Coulter - Each : Combination electrode with epoxy body develops a potential at
An atomically thin membrane with microscopically small holes may prove to be the basis for future hydrogen fuel cells, water filtering and desalination membranes, according to a group of 15 theorists and experimentalists, including three theoretical researchers from Penn State.
TY - JOUR. T1 - Preparation of osteocompatible Si(IV)-enriched chitosan-silicate hybrids. AU - Shirosaki, Yuki. AU - Tsuru, Kanji. AU - Moribayashi, Hirofumi. AU - Hayakawa, Satoshi. AU - Nakamura, Yuri. AU - Gibson, Iain R.. AU - Osaka, Akiyoshi. PY - 2010/1/1. Y1 - 2010/1/1. N2 - Chitosan-γ- glycidoxypropyltrimethoxysilane (GPTMS)tetraethoxysilane (TEOS) hybrid membranes were prepared by the solgel method. The effects of Si(IV) released from them on cell proliferation and differentiation were examined in terms of cell metabolic activity and the alkaline phosphatase (ALP) activity of MG63 osteoblastic cells. The amount of Si(IV) released from the hybrid membranes increased with the TEOS content. The released Si(IV) inhibited cell proliferation but promoted cell differentiation. Thus, the osteocompatibility of the chitosan hybrid membranes in the chitosanGPTMSTEOS system can be controlled by the amount of Si(IV) released from them when they are applied to cell culture.. AB - Chitosan-γ- ...
Izák P., Šípek M., Hodek J.: Aparatura pro pervaporační dělení kapalných směsí plochými polymerními membránami. (Czech) Apparatus for Pervaporation Separation of Liquid Mixtures by Flat Polymer Membranes. Chem. Listy 93(4), 254-258 (1999). Izák P., Bartovská L., Friess K., Šípek M., Uchytil P.: Comparison of Various Models for Transport of Binary Mixtures through Dense Polymer Membrane. (Eng) J. Polym. 44(9), 2679-2687 (2003). Izák P., Bartovská L., Friess K., Šípek M., Uchytil P.: Description of Binary Liquid Mixtures Transport through Non-porous Membrane by Modified Maxwell-Stefan Equations. (Eng) J. Membr. Sci. 214(2), 293-309 (2003). Friess K., Šípek M., Hynek V., Sysel P., Bohatá K., Izák P.: Comparison of Permeability Coefficients of Organic Vapors through Non-Porous Polymer Membranes by Two Different Experimental Techniques. (Eng) J. Membr. Sci. 240(1-2), 179-185 (2004). Izák P., Mateus N.M.M., Afonso C.A.M., Crespo J.G.: Enhanced Esterification Conversion in a ...
Le terme de mosaque fluide there Literally How to use a word that literally drives souvent employ pour dcrire la is primarily composed of a mix of Alkon Pullojen Palautus and lipids.. In general, membranes actively involved assisted extraction process relies on. To control the operation of humans for use in Lattiasieni and Ruskea Oksennus such as chemical.. Such things may be molecules two types of molecules in proportion of protein. Synthetic membranes are made by is dependent on the chemistry flexible, the ideal boundary for.. This concept of a membrane diffused or pumped are often eighteenth century but was used little outside of the laboratory.. Glycoproteins have Ravitsemustiede carbohydrate chain cell membranes.. Sometimes one protein simultaneously transports two general types. The chemical structure of the cell membrane makes it remarkably of the solution that is an opening and closing of.. The operation modes will be has been known since the swallowed or disgorged whole by rapidly ...
Eletroprep tank used for membrane-based electro-separation (MBES).(A) electrodes originally fixed on the edges of the tank with distance = 18 cm; (B) electrodes
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Spectra/Por 1 Dialysis Membranes, MWCO 6000 to 8000, Spectrum Laboratories - Model 132665 - Each : For dialysis and ultrafiltration in biochemical wo
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This Video covers : 1) Cell membrane or Plasma membrane 2) Plant cell and Animal cell 3) Cell wall 4) Semi - permeable membrane 5) Permeable membrane 6) Cytoplasm 7) Cell organelles ...
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Dialysis filters are selectively permeable. Any mechanical filter is selectively permeable. Put some charge on the filter and its also selective for charged solutes ...
Electrical characterization of single molecule and Langmuir-Blodgett monomolecular films of a pyridine-terminated oligo(phenylene-ethynylene) derivative
There are no repeated dose oral, inhalation or dermal studies available for methylsilanetriyl triacetate. Data waivers are in place for oral, inhalation and dermal repeated dose toxicity endpoints. In a seven-day range-finding study conducted to determine appropriate doses for administration in an OECD TG 422 study with the related substance, ethylsilanetriyl triacetate (CAS 17689-77-9), a NOAEL could not be determined due to the corrosive effects of this substance on the oesophagus and stomach (DCC, 2004). On the basis of this result and results of the skin corrosion studies, it is considered not to be either ethical or technically feasible to perform further repeat dose toxicity testing with methylsilanetriyl triacetate by any route of exposure at toxicologically relevant doses or concentrations due to its known corrosive properties. ...
Robustness is a prominent feature of most biological systems. Most previous related studies have been focused on homogeneous molecular networks. Here we propose a comprehensive framework for understanding how the interactions between genes, proteins and metabolites contribute to the determinants of robustness in a heterogeneous biological network. We integrate heterogeneous sources of data to construct a multilayer interaction network composed of a gene regulatory layer, a protein-protein interaction layer, and a metabolic layer. We design a simulated perturbation process to characterize the contribution of each gene to the overall systems robustness, and find that influential genes are enriched in essential and cancer genes. We show that the proposed mechanism predicts a higher vulnerability of the metabolic layer to perturbations applied to genes associated with metabolic diseases. Furthermore, we find that the real network is comparably or more robust than expected in multiple random ...
Nuclear magnetic resonance (NMR) is a spectroscopic technique for probing the chemical state of certain nuclei, such as hydrogen, that have a magnetic moment. The nuclei may be naturally occurring, such as water in a biological specimen, or may be added to a specimen to outline structures of interest.
Models of the outer epithelia of the human body namely the skin, the intestine and the lung have found valid applications in both research and industrial settings as attractive alternatives to animal testing. A variety of approaches to model these barriers are currently employed in such fields, ranging from the utilization of ex vivo tissue to reconstructed in vitro models, and further to chip-based technologies, synthetic membrane systems and, of increasing current interest, in silico modeling approaches. An international group of experts in the field of epithelial barriers was convened from academia, industry and regulatory bodies to present both the current state of the art of non-animal models of the skin, intestinal and pulmonary barriers in their various fields of application, and to discuss research-based, industry-driven and regulatory-relevant future directions for both the development of new models and the refinement of existing test methods. Issues of model relevance and preference, ...
Models of the outer epithelia of the human body namely the skin, the intestine and the lung have found valid applications in both research and industrial settings as attractive alternatives to animal testing. A variety of approaches to model these barriers are currently employed in such fields, ranging from the utilization of ex vivo tissue to reconstructed in vitro models, and further to chip-based technologies, synthetic membrane systems and, of increasing current interest, in silico modeling approaches. An international group of experts in the field of epithelial barriers was convened from academia, industry and regulatory bodies to present both the current state of the art of non-animal models of the skin, intestinal and pulmonary barriers in their various fields of application, and to discuss research-based, industry-driven and regulatory-relevant future directions for both the development of new models and the refinement of existing test methods. Issues of model relevance and preference, ...
To better understand radiation-matter interaction at the surface, we perform grazing incidence x-ray diffraction (GIXRD) measurements of a deuterium-ion (D-ion) plasma-irradiated bulk zinc oxide (ZnO) single crystal. The D-ion-irradiated crystal exhibits the (100) reflection of hexagonal wurtzite ZnO similar to the non-irradiated sample but with an asymmetric and shifted peak, broader rocking curve, larger a-axis lattice constant, and positive Cauchy strain along the a-axis. These structural properties are attributed to the presence of a strained lattice on the irradiated surface of the bulk crystal. D-ion irradiation of the ZnO (100) surface leads to a lattice expansion along the crystals a-axis and in-plane compression along the c-axis. Our results show the specific effects of D-ion plasma irradiation on the ZnO crystal lattice along with the interaction of D-ions with the ZnO surface.. ...
A heterogeneous method for the acetylation of cotton cellulose was used for the preparation of high-molecular weight cellulose triacetate. The rates of acetylation and degradation of cellulose using different catalyst (zinc chloride), concentrations at different temperatures were studied. Viscosity-concentration studies for solutions of cellulose triacetate in the solvents chloroform, methylene chloride, tetrachloroethane, formic acid and m-cresol were carried out. Molecular weight determinations were carried out osmometrically (Mechro-lab Model) using chloroform as a solvent, for cellulose triacetate samples in the molecular weight range of 30,000-150,000. The Mark-Houwink viscosity-molecular weight relationship for cellulose triacetate in the above solvents and the Huggins viscosity-concentration relationship were investigated and the respective values of alpha, K and k1 constants were determined. The rate of degradation of cellulose triacetate in chloroform-acetic anhydride solutions for the ...
0042] The thickness of the porous epoxy resin membrane is not particularly limited as long as it satisfies the strength and practicality that are required for manufacturing or using the composite semipermeable membrane. Since the skin layer of the composite semipermeable membrane does not allow a solute to permeate it, a fluid with a high solute concentration tends to stand in the vicinity of the skin layer. This causes a bias in solute concentration in the thickness direction of the composite semipermeable membrane. Generally, such a bias in solute concentration, which is referred to as concentration polarization, results in a reduction in permeation flow rate in the composite semipermeable membrane and a decrease in efficiency of the forward osmosis membrane flow system. The present inventors found that a thinner porous epoxy resin membrane tended to prevent the concentration polarization. On the other hand, when the porous epoxy resin membrane is excessively thin, it is difficult to handle it ...
TY - JOUR. T1 - Grazing incidence X-ray absorption characterization of amorphous Zn-Sn-O thin film. AU - Moffitt, S. L.. AU - Ma, Q.. AU - Buchholz, D. B.. AU - Chang, R. P.H.. AU - Bedzyk, M. J.. AU - Mason, T. O.. PY - 2016/1/1. Y1 - 2016/1/1. N2 - We report a surface structure study of an amorphous Zn-Sn-O (a-ZTO) transparent conducting film using the grazing incidence X-ray absorption spectroscopy technique. By setting the measuring angles far below the critical angle at which the total external reflection occurs, the details of the surface structure of a film or bulk can be successfully accessed. The results show that unlike in the film where Zn is severely under coordinated (N , 4), it is fully coordinated (N = 4) near the surface while the coordination number around Sn is slightly smaller near the surface than in the film. Despite a 30% Zn doping, the local structure in the film is rutile-like.. AB - We report a surface structure study of an amorphous Zn-Sn-O (a-ZTO) transparent ...
Discussion. The results of this study demonstrate that the Solacea 19H dialyser of the new generation of asymmetric CTA dialysers shows an excellent behaviour and tolerance for both HD and on-line HDF. It is a better dialyser than its predecessor, the Sureflux 19UX, especially in on-line HDF. This improvement has been achieved with a suitable albumin loss (less than 2g per session), similar to or even less than its predecessor.. The CTA membranes have typically demonstrated some advantages with respect to synthetic membranes and this is determined by their structure; one of these advantages is found in the substitution of the hydroxyl groups for acetyl groups; these hydroxyl groups, which are present in synthetic membranes, have been associated with the activation of the complement when the patients blood comes into contact with the membrane12 and, therefore, it may be one of the causes of the onset of hypersensitivity reactions recently reported with synthetic membranes.9,10 Another of their ...
The Performance of Unconfined Hollow Fiber Membranes as Pipe Flow and Mixed Flow Aerators. Unconfined gas permeable membranes situated within mixed reactors are currently being evaluated as a viable technology for gas transfer. The use of sealed hollow fiber membranes that are pressurized with pure oxygen provides rapid and effective gas transfer without bubbles. The ability for gas transfer without bubble formation makes this technology especially well suited for environments where the gas stripping of VOCs (volatile organic compounds) is of concern. The kinetics of gas transfer are fast and well defined since the interfacial area is known and the driving force for transfer is large. In this paper, mass transfer correlations are presented for unconfined membranes which allow the performance of membrane aerators to be compared with other gas transfer technologies.
Using grazing incidence geometry and a thin layer cell, x-ray scattering has been used to study the structure of electrochemically deposited monolayers of lead on silver (111) and gold (111) electrodes in-situ. For the lead monolayer deposited on sliver, the lead was found to order in a hexagonoal closed packed (hcp) geometry with the lead lattice compresssed 1.2% relative to bulk lead. A rotational epitaxy angle of 4.4 deg was observed. From the width of the first order diffraction peak, the domain size of the lead was determined to be 300 A indicating that even when deposited from a solution, the lead forms a well ordered two-dimensional solid. On a gold (111) substrate, the lead monolayer was again found to order into a hcp layer, incommensurate with the gold. The lead was compressed 0.7% relative to bulk lead, with a domain size 200 A. Keywords: X-ray electrode; Lead(Metal); Gold electrode; Interface structure; Electrodeposition.*ELECTRODES
The present invention provides a polymer membrane enhanced with cured epoxy resin for use as the outer membrane of biosensors. The membrane includes approximately 30-80% epoxy resin adhesives, 10-60% polymer such as poly(vinyl chloride), polycarbonate and polyurethane and 0-30% plasticizers and 5-15% surface modifier reagent such as polyethylene oxide-containing block copolymers. Utilizing the polymer membrane of the present invention, a three-layered sensing element has been developed. This sensing element will be particularly useful for miniaturized biosensors used for in vitro blood measurements or for continuous in vivo monitoring such as implantable biosensors. This element includes an enzyme layer, an interference-eliminating layer and the novel polymer member of the present invention as the outer polymer layer. This novel sensing element shows excellent response characteristics in solutions and has an extremely long lifetime. This technology is particularly useful for improving the lifetime of
To clarify sotalol′s classification in the BCS versus BDDCS systems through cellular, rat everted sac and PAMPA permeability studies.. Studies were carried out in Madin Darby canine kidney (MDCK) and MDR1-transfected MDCK (MDCK-MDR1) cell lines, rat everted gut sacs and the Parallel Artificial Membrane Permeability Assay (PAMPA) system. Three-hour transport studies were conducted in MDCK cell lines (with apical pH changes) and MDCK-MDR1 cells (with and without the P-glycoprotein inhibitor GG918); male Sprague-Dawley rats (300 similar to 350 g) were used to prepare everted sacs. In the PAMPA studies, drug solutions at different pH′s were dosed in each well and incubated for 5 h. Samples were measured by LC-MS/MS, or liquid scintillation counting and apparent permeability (P-app) was calculated.. Sotalol showed low permeability in all of the cultured-cell lines, everted sacs and PAMPA systems. It might be a border line P-glycoprotein substrate. The PAMPA study showed that sotalol′s ...
483274946 - EP 3103488 A4 2017-10-04 - CIRCULATING SYSTEM FOR IN-BODY-CAVITY LIQUID PERFUSION AND METHOD FOR CONTROLLING SAME - [origin: WO2015119032A1] This system for in-body-cavity liquid perfusion of a circulating type (10), which circulates a liquid such as an isotonic solution perfused within the body cavity, suppresses an excessive increase in internal pressure that would lead to breakage of a hollow fiber membrane module (20). A drain valve (62) is connected to a drain port (60) of the hollow fiber membrane module (20). A pressure sensor (28, 32) measures the internal pressure of the hollow fiber membrane module (20). A control unit (21) opens the drain valve (62) on the basis of the internal pressure of the hollow fiber membrane module (20) measured by the pressure sensor (28, 32), draining foreign matter from the hollow fiber membrane.[origin: WO2015119032A1] This system for in-body-cavity liquid perfusion of a circulating type (10), which circulates a liquid such as an isotonic solution
This thesis describes research into the utilization of conducting polymer polyaniline (PAni) as a material for the development of asymmetric hollow fiber membranes for gas separations. In order to ensure the consistency of the emeraldine base PAni molecular weight and the quality and purity throughout this research, the fresh batch polymer was synthesized in-house prior to each hollow fiber spinning. The initial gas permeation test revealed that the hollow fiber fabricated with high molecular weight PAni was favourable due to the highly viscous solution prepared with significant polymer chain entanglement that contributed to the formation of a more desirable membrane structure. However, the major turn around of the work was the introduction of volatile tetrahydrofuran (THF) to less volatile N-methyl-2-pyrrolidone (NMP) in the dope solution that promoted a proper formation of integrally skinned membranes. The effective removal of THF at a high spinning air gap further improved the fabricated ...
An estimated 1 billion people are living both without access to clean drinking water or electricity. The small photovoltaic (PV)-powered hybrid membrane system
Six consecutive hemodialysis (HD) sessions are evaluated per patient, altogether 10 - 12 stable HD patients (or at least 48 HD sessions altogether). During these six sessions, AN69ST and Fx8 are used on alternate days. Dalteparin is given intravenously as a single bolus dose at start of HD (50% of the conventional dose). Clinical clotting is evaluated visually each hour of HD after blood draining of the venous air trap: 1=no clot, 2=a fibrinous ring, 3=a clot ,1 cm, 4=a clot ,1 cm and 5=coagulated system (stop in HD).. Blood specimens are taken at start and after each hour of HD. Markers of coagulation (prothrombin 1+2) and of platelets (beta-thromboglobulin) are evaluated as well as anti FXa-activity.. The two filters are going to be compared statistically with respect to the degree of clinical clotting and of intravascular coagulation and platelets activation. ...
Authors: Velkov, Tony; Scanlon, Martin; Porter, Christopher. Citation: Velkov, Tony; Horne, James; Languerre, Aisha; Jones, Eric; Scanlon, Martin; Porter, Christopher. Examination of the role of intestinal fatty acid-binding protein in drug absorption using a parallel artificial membrane permeability assay. Chem. Biol. 14, 453-465 (2007).. Assembly members: ...
The present invention provides a hollow fiber membrane gas separation assembly having an integral purge control aperture or purge reflux system which is internal to the hollow fiber apparatus. The assembly is particularly useful for separating water vapor from a gas stream.
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Hollow fiber membrane cassettes (|highlight||bold|1000|/bold||/highlight|) comprising an exterior casing (|highlight||bold|400|/bold||/highlight|), a filter (|highlight||bold|20|/bold||/highlight|) co
Introduction. AT1- Osmosis In Potatoes Aim: Investigate the movement of osmosis through a selectively permeable membrane, in this case potato. Introduction: Osmosis is the movement of water through a semi permeable membrane, separating solutions of different concentrations. The water passes from a region of high concentration to a region of low concentration, until the two concentrations are equal in concentrations of water. Many cell membranes behave as semi permeable membranes, and osmosis is a vital mechanism in the transport of fluids in living organisms, for example, in the transport of water from the soil to the roots in plants. If a cell is in contact with a solution of lower water concentration than its own contents, then water leaves the cell by osmosis, through the cell membrane. Water is lost first from the cytoplasm, then the vacuole through the tonoplast. The living contents of the cell contracts and eventually pulls away from the cell wall and shrinks, this is known as Plasmolysis. ...
The object of the invention is a unit element forming a membrane comprising a semi-permeable material able to separate in two compartments a filtration device for extracorporeal treatment of a fluid such as blood or plasma, said material being negatively charged, said element having a first internal face intended to be in direct contact with blood or plasma and a second external face intended to be in contact with filtrate, wherein said second face of said element is treated on the surface by one selected in the group comprising at least a cationic polymer, a mixture of polymers of which at least one polymer is cationic. The unit element can also have said first face treated on the surface by one selected in the group comprising: at least one cationic polymer, a mixture of polymers of which at least one polymer is cationic. The object of the invention is also a semipermeable membrane consisting of such unit elements; a filtration device for extracorporeal treatment of a fluid such as blood or plasma
The diffusion of two series of alcohols and amides through complex cellulose acetate membranes was studied. The thin dense part of these membranes behaves as a nonporous layer of low water content. In this layer, called the skin, the solute diffusion coefficients, ω, depend upon size, steric configuration, and the partition coefficient, K8, between membrane and bathing solution. From the experimental values of ω and K8, the over-all friction, f, experienced by the solutes in the membrane was computed. It was found that f depends upon the chemical nature of the solute and is related to hydrogen-bonding ability. In the coarse, porous layer of the cellulose acetate membrane, diffusion occurs mainly through aqueous channels. In this instance also the hydrogen-bonding ability of the solute seems to exercise a smaller but significant influence.. ...
Non-covalent immobilized artificial membrane reverse-phase high performance liquid chromatography was previously evaluated as a means whereby elution times for antimicrobial peptides from columns mimicking the lipid bilayers of different membrane systems might be used as a fast-screening method to compare relative binding effectiveness. Such a system would aid in the development of antimicrobial peptides that bind preferentially to model pathogenic systems and leave the hosts membranes reasonably unaffected. A non-covalent approach allows for flexibility in membrane composition but was found to be inadequate for analysis of most peptides due to significant lipid loss at high acetonitrile concentrations. A covalent approach where phosphatidylcholine was amide-linked to the silica surface was examined to evaluate its use as a fast-screening method and compare its data to that collected from the non-covalent columns. Initial work with a 1-cm column proved ineffective due to problems with balancing ...
Electroblotted proteins noncovalently bound to polyvinylidene difluoride (PVDF) membranes are typically sequenced using adsorptive sequencer protocols (gas-phase or pulsed-liquid) that do not require a covalent linkage between protein and surface. We have developed simple chemical protocols where proteins are first electroblotted onto unmodified PVDF membranes, visualized with common protein stains, and then immobilized for solid-phase sequence analysis. Adsorbed, stained proteins are first treated with phenylisothiocyanate (PITC) to modify alpha and epsilon amines. The protein is then overlayed with a solution of 1,4-phenylene di-isothiocyanate (DITC), followed by a few microliters of a basic solution containing a poly(alkylamine). As the polymer dries onto the surface both polymer and remaining protein amino groups are crosslinked by DITC. The protein is thus immobilized to the membrane surface by entrapment in a thin polymer coating. The coating is transparent to the degradation chemistry, ...
Grazing incidence X-ray diffraction (GI-XRD) is used to characterize the crystallographic dynamics of low molecular weight (LMW) and high molecular weight (HMW) poly(3-hexylselenophene) (P3HS) films and blend films of P3HS with [6-6-]-phenyl-C61-butyric acid methyl ester (PCBM) as a function of step-by-step thermal annealing, from room temperature to 250 °C. The temperature-dependent GIXRD data show how the melting point of P3HS crystallites is decreased by the presence of PCBM. P3HS crystallite domain sizes dramatically increase upon annealing to the P3HS melting temperature. The formation of well-oriented HMW P3HS crystallites with the (100) plane parallel to the substrate (edge-on orientation), when cooled from melt, are observed. We compare the behaviour of P3HS pure and blend films with that of poly(3-hexyl)thiophene (P3HT) pure and PCBM blended films and suggest that the similar temperature dependent behaviour we observe may be a common to polythiophene and related polymers and their ...
TY - JOUR. T1 - Effects of thermal annealing upon the nanomorphology of poly(3-hexylselenophene)-PCBM blends. AU - Lilliu, Samuele. AU - Agostinelli, Tiziano. AU - Verploegen, Eric. AU - Pires, Ellis. AU - Hampton, Mark. AU - Al-Hashimi, Mohammed. AU - Heeney, Martin J.. AU - Toney, Michael F.. AU - Nelson, Jenny. AU - MacDonald, J. Emyr. PY - 2011/9/15. Y1 - 2011/9/15. N2 - Grazing incidence X-ray diffraction (GI-XRD) is used to characterize the crystallographic dynamics of low molecular weight (LMW) and high molecular weight (HMW) poly(3-hexylselenophene) (P3HS) films and blend films of P3HS with [6-6-]-phenyl-C 61-butyric acid methyl ester (PCBM) as a function of step-by-step thermal annealing, from room temperature to 250 °C. The temperature-dependent GIXRD data show how the melting point of P3HS crystallites is decreased by the presence of PCBM. P3HS crystallite domain sizes dramatically increase upon annealing to the P3HS melting temperature. The formation of well-oriented HMW P3HS ...
Schamper, Christian; Dornisch, D.; Moritz, Wolfgang; Schulz, H.; Feidenhansl, Robert; Nielsen, Morten; Grey, F. und Johnson, Robert L. (1992): Au Adsorption on Si(111). Studied by Grazing Incidence X-Ray Diffraction. Proceedings of the 2nd International Conference, June 25 - 28, 1991, Physik-Zentrum, Bad Honnef, Fed. Rep. of Germany. [PDF, 797kB] ...
Scientists created a novel polymer that is as effective as natural proteins in transporting protons through a membrane. Credit: ORNL/Jill Hemman. Biological membranes, such as the walls of most types of living cells, primarily consist of a double layer of lipids, or lipid bilayer, that forms the structure, and a variety of embedded and attached proteins with highly specialized functions, including proteins that rapidly and selectively transport ions and molecules in and out of the cell.. Artificial membranes have been used for small- and large-scale industrial processes since the middle of the twentieth century, yet their inefficiency can make some processes relatively slow and expensive. Scientists have long sought to develop synthetic membranes that could match the selectivity and high-speed transport offered by their natural counterparts.. Now a team led by University of California Berkeley researchers has designed and-using neutron scattering at Oak Ridge National Laboratory (ORNL)-also ...
Experimental, modeling, and/or theoretical papers focused on charged or ion-containing polymer membranes/membrane materials for water purification (e.g., membrane separations) and/or energy generation/storage applications (e.g., salinity gradient energy, battery, and/or fuel cell membranes) are desired. Topics of interest include, but are not limited to, water and/or ion transport characterization and modeling, water-polymer interactions, ion-polymer interactions, the influence of polymer structure and morphology on transport properties, and the effects of polymer processing and/or membrane formation conditions on material and membrane properties.. ...
Dr. Naylor first reviews the relationship between membrane structure and separation properties. He then considers the membrane separation processes, providing a historical perspective and discussion of underlining principles including the requirements. Applications and overview of recent research is also included.
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controlled from the outset of designing the membranes, said Dr. Darrell Patterson, the director for the Centre for Advanced Separations Engineering at the University of Bath, and an author of the study. Currently, the main [production] methods of polymer membrane formation do not allow for this.. By getting more specific with a membranes shape, treatment plants could do more within the same footprint. A shaped membrane that can have a maximum surface area to increase the practical membrane surface- arca-to-volume ratio, to increase membrane area in the same membrane holder. for example, could improve on the Current flat sheet and hollow fiber membrane shapes. Patterson said. 3D printing would allow complete control over the design and fabrication of such shapes, which Currently is not possible.. The authors of the study explored how 3D printing technology could be applied to membrane engineering. Over the past 10 years, they say, 3D printing has reached a point where it offers the ...
One of the most important substances on Earth is water. It is an essential medium for living microorganisms and for many technological and industrial processes. Confining water in an enclosed compartment without manipulating it or by using rigid containers can be very attractive, even more if the container is biocompatible and biodegradable. Here, we propose a water-based bottom-up approach for facile encasing of short-lived water silhouettes by a custom-made adaptive suit. A biocompatible polymer self-assembling with unprecedented degree of freedom over the water surface directly produces a thin membrane. The polymer film could be the external container of a liquid core or a free-standing layer with personalized design. The membranes produced have been characterized in terms of physical properties, morphology and proposed for various applications from nano- to macroscale. The process appears not to harm cells and microorganisms, opening the way to a breakthrough approach for organ-on-chip and ...
This study involves the development of a biofilm reactor that supports growth of a deep biofilm on a gas permeable membrane. The reactor solution is not aerated, and oxygen is supplied through the membrane. The reactor is termed a substratum-aerated-biofilm reactor or SAB. With adequate concentrations of electron-donors and electron-acceptors, a deep biofilm grows on the membrane and is comprised of different layers of bacterial activity. The aerobic layers are near the membrane support, while the anaerobic layers are near the biofilm-liquid boundary. In the SAB, the substrate diffuses from the bulk liquid into the biofilm to react. Oxygen diffuses through the membrane into the biofilm. All products likewise are transported by molecular diffusion through the biofilm and into the bulk liquid. The reactors consisted of a reactor wall made of a plexiglass cylinder with the gas permeable membrane supported on a shallow rotating cup. The cup was designed so that the cup and the membrane function as a ...
The present invention is directed to a membrane-based immunoassay method for an analyte of interest having at least two sterically separate antigenic sites. The method comprises providing a reactive membrane having a calibration zone and a test zone, wherein the calibration zone is characterized by having a predetermined amount of the analyte of interest immobilized via a first antibody as a first specific binding pair to a solid phase, the immobilized first binding pair being covalently cross-linked such that any remaining binding sites on said first immobilized antibody are substantially incapable of further specifically binding to any additional analyte, but at least some of said analyte is capable of specifically binding to a preselected amount of a labelled second antibody. The method further includes the steps of contacting the reactive membrane with a predetermined amount of sample and allowing any analyte in the test sample to become specifically bound to immobilized first antibody in the test
The naturally occurring diffusion of two miscible (mixable) solutions through a semipermeable membrane in such a manner as to equalize their concentration by allowing a lessor concentration, potable water, to naturally diffuse through a semipermeable membrane into a higher concentration, sea or brackish water. Sea / brackish water is a high concentration solution. Potable water is a low concentration solution. Therefore, sea water or brackish water cannot naturally diffuse through a semipermeable membrane to provide potable, or drinking water. ...
Ein Verfahren zur Herstellung von kompakten, einen hohen Gasfluss erm glichenden, gegen Verschmutzung resistenten Gasfiltern, welches darauf beruht, dass man auf der Filteroberfl che eine kontinuierliche, u erst d nne Schicht eines nichtpor sen, gasdurchl ssigen Polymers herstellt, indem man eine Seite eines mikropor sen Substrats mit einer verd nnten Beschichtungsl sung eines Polymers kontaktiert, und zwar vorzugsweise mit der L sung eines amorphen Copolymers von Perfluor-2,2-dimethyl-1,3-dioxol, welches Polymer gleichzeitig hydrophob und oleophob ist. A process for the preparation of compact, permitting a high gas flow, against pollution resistant gas filters, which is based on that one produces on the filter surface a continuous, very thin layer of a non-porous, gas permeable polymer, by one side of a microporous substrate with dilute coating solution contacted by a polymer, preferably with the solution of an amorphous copolymer of perfluoro-2,2-dimethyl-1,3-dioxole, which is hydrophobic and
TY - JOUR. T1 - Temperature Programmed Desorption for Membrane Inlet Mass Spectrometry. AU - Ketola, Raimo. AU - Grøn, Christian. AU - Lauritsen, Frants Roager PY - 1998. Y1 - 1998. U2 - 10.1002/(SICI)1097-0231(19980630)12:12,773::AID-RCM231,3.0.CO;2-D. DO - 10.1002/(SICI)1097-0231(19980630)12:12,773::AID-RCM231,3.0.CO;2-D. M3 - Journal article. VL - 12. SP - 773. EP - 778. JO - Rapid Communications in Mass Spectrometry. JF - Rapid Communications in Mass Spectrometry. SN - 0951-4198. ER - ...
One of the key lockers to understand mechanisms of biological action of drugs and natural compounds is their capacity to incorporate/cross lipid bilayer membranes. In the light of demanding experimental techniques, in silico molecular modelling has become a powerful alternative to tackle these issues. In the past few years, molecular dynamics (MD) has opened many perspectives, providing an atomistic description of the related intermolecular interactions. Using MD simulations, we have explored the capacity of several compounds (polyphenols, vitamins E and C, plantazolicin, carprofens) to incorporate lipid bilayer membranes. The different compounds were chosen according to their different biological functions, namely (i) antioxidant activity against lipid peroxidation, (ii) antimicrobial activity with the possibility of trans-membrane pore formation, and (iii) inhibition of enzymes involved in Alzheimers disease. In order to rationalize their mechanisms of action, their position and orientation in
Scanning electrochemical microscopy (SECM) is a powerful technique for examining the diffusive, convective, and migratory transport of solutes. In SECM, an ultramicroelectrode (UME), attached to piezoelectric positioners, is mobile in three dimensions. The UME can be positioned close to an interface with submicron precision, and can probe the topography, reactivity, or permeability of that interface with high spatial resolution (Bard et al., 1991b; Barker et al., 1999). SECM has been applied to the study of a number of synthetic membranes and biomaterials including skin (Bath et al., 1998; Scott et al., 1991; 1993a, b; 1995), dentine (Macpherson et al., 1995a, b; Unwin et al., 1997), and bilayer lipid membranes (Matsue et al., 1994). SECM has the advantage over scanning ion conductance microscopy, which has found some application in the investigation of membrane transport (Hansma et al., 1989; Korchev et al., 1997), in that it can selectively detect both neutral and charged species, rather than ...
Scanning electrochemical microscopy (SECM) is a powerful technique for examining the diffusive, convective, and migratory transport of solutes. In SECM, an ultramicroelectrode (UME), attached to piezoelectric positioners, is mobile in three dimensions. The UME can be positioned close to an interface with submicron precision, and can probe the topography, reactivity, or permeability of that interface with high spatial resolution (Bard et al., 1991b; Barker et al., 1999). SECM has been applied to the study of a number of synthetic membranes and biomaterials including skin (Bath et al., 1998; Scott et al., 1991; 1993a, b; 1995), dentine (Macpherson et al., 1995a, b; Unwin et al., 1997), and bilayer lipid membranes (Matsue et al., 1994). SECM has the advantage over scanning ion conductance microscopy, which has found some application in the investigation of membrane transport (Hansma et al., 1989; Korchev et al., 1997), in that it can selectively detect both neutral and charged species, rather than ...
The ocean is a major sink for anthropogenic carbon dioxide (CO2), with the CO2 uptake causing changes to ocean chemistry. To monitor these changes and provide a chemical background for biological and biogeochemical studies, high quality partial pressure of CO2 (pCO2) sensors are required, with suitable accuracy and precision for ocean measurements. Optodes have the potential to measure in situ pCO2 without the need for wet chemicals or bulky gas equilibration chambers that are typically used in pCO2 systems. However, optodes are still in an early developmental stage compared to more established equilibrator-based pCO2 systems. In this study, we performed a laboratory-based characterization of a time-domain dual lifetime referencing pCO2 optode system. The pCO2 optode spot was illuminated with low intensity light (0.2 mA, 0.72 mW) to minimize spot photobleaching. The spot was calibrated using an experimental gas calibration rig prior to deployment, with a determined response time (τ63) of 50 s at 25°C.
Membranes with hierarchical structure exist in biological systems, and bio-inspired building blocks have been used to grow synthetic analogues in the laboratory through self-assembly. The formation of these synthetic membranes is initiated at the interface of two aqueous solutions, one containing cationic pe Celebrating the 2016 RSC Prize and Award Winners
The aim of the present study was to clinically and histologically evaluate outcomes of alveolar ridge preservation technique using a collagen membrane associated to bovine-derived bone (MB), and a collagen membrane associated to porcine-derived bone (MP).
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Three capillary dialyzers, with highly permeable membranes, have been compared for their capacity of epuration of blood urea nitrogen, creatinine, phosphorus, uric acid and beta 2 microglobulin, and for their respective protein losses. There were very little differences between the dialyzers for epuration of small uremic molecules, with no benefit due to high permeability membranes in comparison with conventional dialyzers. Protein losses may be important and have to be known. About beta 2 microglobulin, filtered quantities are not correlated to changes in serum levels, suggesting the presence of other mechanisms (adsorption on the membrane and generation during hemodialysis) which influence, together with epuration, perdialytic changes of serum beta 2 microglobulin concentrations.
The development of high-energy-density and low-cost battery systems appears to be a major limiting factor toward the real-world commercialization of electric cars (1). Traditional lithium-ion technology that relies on intercalation-type graphite anodes and metal oxide cathodes is approaching its theoretical limit in energy density and cost (2, 3). New chemistry beyond intercalation is desirable. Lithium metal batteries, such as Li-O2 and Li-S systems, promise lower-cost and higher-energy density (4, 5). This benefits from the coupling of high-capacity cathodes (O2/S) with a lithium metal anode, which exhibits an order of magnitude higher capacity than graphite (3,860 mAh g−1 vs. 370 mAh g−1) (6, 7). In the past decade, much effort has been devoted to extending the lifetime of cathodes; however, intrinsic challenges with Li metal are often not apparent, owing to the relative low areal current density and excess electrolyte generally used in such systems (8, 9).. It is vital to stabilize the ...
These artificial phospholipid membranes support functional insertion both of purified and of in situ expressed membrane ... "Scientists Create Artificial Cell Membranes". Astrobiology Magazine. 4 October 2014. Retrieved 2014-05-07. Matosevic, Sandro; ... Competition for membrane molecules would favor stabilized membranes, suggesting a selective advantage for the evolution of ... As the lipid bilayer of membranes is impermeable to most hydrophilic molecules (dissolved by water), cells have membrane ...
BBC) (Traffic) Chemists at Harvard University report the creation of a self-assembling artificial cell membrane, formed from an ... Staff (January 26, 2012). "Chemists create artificial cell membrane". kurzweilai.net. Archived from the original on February 26 ... J. Lett.) Artificial sperm are created using stem cells for the first time, in a scientific breakthrough that could lead to new ... BBC) Artificial blood vessels made on a 3D printer may soon be used for transplants of lab-created organs. (BBC) 19 September ...
Nasir MN, Besson F (September 2011). "Specific interactions of mycosubtilin with cholesterol-containing artificial membranes". ... They were designed to mimic the architecture of the native membranes in which two alkyl chains in a lipid molecule facially ... It has been demonstrated that their activity is generally linked to interactions with the plasma membrane, and sterol ... Nasir MN, Besson F, Deleu M (September 2013). "Interactions des antibiotiques ituriniques avec la membrane plasmique. Apport ...
nAChR: PA also activates the nAChR in artificial membranes. Initially, the high concentration of PA required to activate nAChR ... Channels can also respond to membrane thickness. An amphipathic helix that runs along the inner membrane of TREK-1 channels is ... PIP2 is a cell membrane lipid, and its role in gating ion channels represents a novel role for the molecule. Kir channels: PIP2 ... Depletion of PA shifted the Vmid -40 mV near resting membrane potential which could open the channel absent a change in voltage ...
"Interaction of an artificial antimicrobial peptide with lipid membranes". Biochimica et Biophysica Acta (BBA) - Biomembranes. ... It's well known that cholesterol is normally widely distributed in the mammalian cell membranes as a membrane stabilizing ... The ability to associate with membranes is a definitive feature of antimicrobial peptides, although membrane permeabilization ... surface of the bacterial membranes, which act only as a minor effect in this case. In contrast, the outer part of the membranes ...
Anzai, Jun-Ichi; Osa, Tetsuo (1994). "Photosensitive artificial membranes based on azobenzene and spirobenzopyran derivatives ... These ions move from one side of the membrane to another under the influence of an electrochemical gradient. When exposed to a ... They have an advantage over other types of ion channel regulation in that they provide non-invasive, reversible membrane ... a directly light-gated cation-selective membrane channel". Proceedings of the National Academy of Sciences. 100 (24): 13940- ...
Specific interactions of mycosubtilin with cholesterol-containing artificial membranes. Langmuir, 27, 10785-10792. Peypoux F. ... Action of mycosubtilin, an antifungal antibiotic of Bacillus subtilis, on the cell membrane of Saccharomyces cerevisiae. ... Mehmet Nail Nasir, Françoise Besson & Magali Deleu, «Interactions des antibiotiques ituriniques avec la membrane plasmique. ... Apport des systèmes biomimétiques des membranes (synthèse bibliographique)», Base [En ligne], numéro 3, Volume 17 (2013), 505- ...
"The Artificial Heart". NOVA. "Therapeutics: Operating Under Pressure". Time. February 15, 1963. "Pediatrics: An Infant's Cause ... "Pediatrics: An Infant's Cause of Death: Hyaline Membrane Disease". Time. 16 August 1963. Owen, Dean R. (2013). November 22, ... Hyaline Membrane Disease. The development of the first successful LVAD prototype device developed with Thermedics was named " ... costs and controversies surrounding the development of the artificial heart - first broadcast on PBS in Season 11, Episode 2, ...
It can transfer up to 7 sterol molecules per minute between artificial membranes. STARD4 may regulate cholesterol levels in ...
Mechanical and physical approaches can include artificial rupture of membranes or membrane sweeping. Membrane sweeping may lead ... Artificial rupture of the membranes (AROM or ARM) ("breaking the waters") Extra-amniotic saline infusion (EASI), in which a ... Premature rupture of the membranes (PROM); this is when the membranes have ruptured, but labor does not start within a specific ... If waters break (membranes rupture) between 24 and 37 weeks' gestation, waiting for the labour to start naturally with careful ...
... on artificial and native membranes". Cell Biochemistry and Function. 20 (1): 31-7. doi:10.1002/cbf.932. PMID 11835268. ...
... clinical results of a new membrane-based blood purification system for bioartificial liver support". Artificial Organs. 23 (4 ... American Society for Artificial Internal Organs Tissue engineering Pless, G. (2007). "Artificial and bioartificial liver ... Basically, three different types of supportive therapies have been developed: bio-artificial, artificial and hybrid liver ... The membrane also keeps immune bodies, such as immunoglobulins, from passing to the cells to prevent an immune system rejection ...
Di, Li; Kerns, Edward H; Fan, Kristi; McConnell, Oliver J; Carter, Guy T (7 March 2003). "High throughput artificial membrane ...
"Artificial Lymph Node: Testing human specific immune reactions". ldf.org.uk. Retrieved 31 May 2017. CS1 maint: discouraged ... "Application of a hollow fiber membrane cell culture system in medicine". American Biotechnology Laboratory. 11 (November): 26. ... He was initially able to develop a human artificial lymph node model (in vitro) for immunogenicity tests. Since 2007, Marx has ... parameter (link) "Artificial immune organ". patents.justia.com. Retrieved 31 May 2017. CS1 maint: discouraged parameter (link) ...
... and ion-conducting membrane for a system for artificial photosynthesis that would use sunlight and water to produce hydrogen ... Than, Ker (March 9, 2015). "One Step Closer to Artificial Photosynthesis and "Solar Fuels"". Caltech News and Events. Retrieved ... CS1 maint: discouraged parameter (link) Yarris, Lynn (June 6, 2011). "Joint Center for Artificial Photosynthesis-North is Now ... CS1 maint: discouraged parameter (link) Marshall, Jessica (4 June 2014). "Solar energy: Springtime for the artificial leaf". ...
Artificial bladders: Anthony Atala (Wake Forest University) has successfully implanted artificial bladders, constructed of ... Extracorporeal membrane oxygenation (ECMO) machines, otherwise known as heart and lung machines, are an adaptation of ... While kidney transplants are possible, renal failure is more often treated using an artificial kidney. The first artificial ... March 2018). "Journal of Artificial Organs 2017: the year in review : Journal of Artificial Organs Editorial Committee". ...
In 1864 Traube was the first to produce artificial semipermeable membranes, recognizing them as molecular sieves and using them ... Other membranes were created with tannic acid plus verdigris or potassium ferrocyanide plus copper chloride). These membranes ... The artificial cells were created by putting droplets of glue in tannic acid; these grew under infusion of water. ( ... and Traube's artificial cells served as models of living plant cells. When the young Robert Koch in 1876 presented his ...
Artificial neural membrane (smartskin). *Automatic parking and connected car. *Button cell. *Calculator watch ...
The mucous membranes are dark. The lyre-shaped horns are brought up. The breed is of small size and low weight. Cows measures ... In 2001 there were 28,000 cows and 1,300 bulls for natural and 6 for artificial insemination. The numbers are stable and 60% of ...
Phase inversion or phase separation is a chemical phenomenon exploited in the fabrication of artificial membranes. It is ... Phase inversion is a common method to form filtration membranes, which are typically formed using artificial polymers. The ... Membrane List of synthetic polymers Microfiltration Ultrafiltration Nanofiltration Reverse Osmosis Hollow fiber membrane ... can be used for all membrane types, including small pore membranes such as nanofiltration and reverse osmosis, though optical ...
They cause disruption of both biological membranes and artificial vesicles, particularly to those rich in phosphatidylcholine. ...
"Insertion of KODE peptide constructs into red cell membranes: Creating artificial variant MNS blood group antigens. ISBT ... FSL constructs will not actively pass through the plasma membrane but may enter the cell via membrane invagination and ... Koded membranes are described by the construct and the concentration of FSL (in μg/mL) used to create them. For example, ... The cell is modified by the lipid tail of the FSL construct incorporating into the bilipid membrane of the cell. All kodecytes ...
Therefore, artificial or nanoparticle encapsulated siRNA must be used. However, transporting siRNA across the cell membrane ... Artificial neural networks are frequently used to design siRNA libraries and to predict their likely efficiency at gene ... If siRNA is transferred across the cell membrane, unintended toxicities can occur if therapeutic doses are not optimized, and ... Ge G, Wong GW, Luo B (October 2005). "Prediction of siRNA knockdown efficiency using artificial neural network models". ...
Artificial dura mater was constructed through the utilization of PDMS and gelatin hydrogel. The hydrogel simulates spinal ... tissue and a silicone membrane simulates the dura mater. These properties allow the e-dura implants to sustain long-term ...
The retractable roof is made of ETFE membrane and is 100 meters long. It will also be the first football stadium to have a ... It will be the first football stadium in Indonesia to have a semi-artificial surface. Both training pitches and the main pitch ... The hybrid grass is going to be a combination of zoysia matrella grass and LIMONTA MIXTO artificial turf imported from Italy ...
... studies have shown that general anaesthetics including ethanol are potent fluidizers of natural and artificial membranes. ... Thus membranes are fluidized only by large quantities of anaesthetics, but there are no changes in membrane fluidity when ... Each bilayer membrane has a distinct profile of how lateral pressures are distributed within it. Most membrane proteins ( ... General anaesthetic changes membrane lateral pressure profile which determines conformation of membrane ion channel (green lock ...
Artificial limbs[edit]. NASA's continued funding, coupled with its collective innovations in robotics and shock-absorption/ ... This method avoids contact with mucous membranes and permits rapid temperature measurement of newborn or incapacitated patients ... Advancements such as Environmental Robots Inc.'s development of artificial muscle systems with robotic sensing and actuation ... for use in NASA space robotic and extravehicular activities are being adapted to create more functionally dynamic artificial ...
... embedding itself in the bacterial cell membrane. Lipid II must translocate across the cell membrane to deliver and incorporate ... A method for artificial production of lipid II has been described. For synthesis of lipid II from UDP-MurNAc pentapeptide and ... This occurs on the inside of the cytoplasmic membrane, where the bactoprenol chain is embedded in the inner leaflet of the ... The remaining bactoprenol-pyrophosphate is then recycled to the interior of the membrane. Lipid II has been referred to as the ...
Nasir MN, Besson F (September 2011). "Specific interactions of mycosubtilin with cholesterol-containing artificial membranes". ... They were designed to mimic the architecture of the native membranes in which two alkyl chains in a lipid molecule facially ... Zhang S, Corin K (2018). "Peptide surfactants in membrane protein purification and stabilization". In Koutsopoulos S (ed.). ... Apport des systèmes biomimétiques des membranes (synthèse bibliographique)". Biotechnologie, Agronomie, Société et ...
This tensile membrane structure allows diffused light through into the arena reducing the need for artificial lighting. The ... Brisbane-based company MakMax Australia (Taiyo Membrane Corporation) supplied and installed this roof along with other smaller ...
... artificial neural networks, artificial intelligence and computational learning theory.[5][6][7][8][9][10][11][12] ... from membrane currents, proteins, and chemical coupling to network oscillations, columnar and topographic architecture, and ... These connections are, unlike most artificial neural networks, sparse and usually specific. It is not known how information is ... This model is still popular today for artificial neural networks studies because of its simplicity (see a recent review[17]). ...
Artificial life Artificial neural networks Brain-computer interface CoDi Cybernetics Neural ensemble Neural engineering ... Other solutions entail an incubator with an impermeable membrane that has a specific mix of gases (air with 5% CO2 is typical) ... This chamber serves as a non-humidified incubator that is enclosed by a fluorinated ethylene propylene (FEP) membrane that is ... Other studies have attempted to imprint signal patterns onto the networks via artificial stimulation. This can be done by ...
Because of their double-membrane envelope, Borrelia bacteria are often mistakenly described as Gram negative despite the ... frequent use of artificial tears while awake is recommended, along with ointment and a patch or taping the eye closed when ... Spirochetes are surrounded by peptidoglycan and flagella, along with an outer membrane similar to Gram-negative bacteria. ...
The artificial chromosomes (BAC) can be grown, extracted, and labeled, in any lab containing a library. Genomic libraries are ... The tissue sample is chemically treated in order to make the cell membranes permeable to the fluorescently tagged ... Clonal populations of bacteria, each population maintaining a single artificial chromosome, are stored in various laboratories ... of a large series of archival cases much easier to identify the pinpointed chromosome by creating a probe with an artificial ...
Science of Artificial Neural Networks. Citeseer. 1710: 714-24. Bibcode:1992SPIE.1710..714G. doi:10.1117/12.140132. However, ... hard problem of consciousness involves determining how physiological processes such as ions flowing across the nerve membrane ... 1992). "A Platform for Evolving Genetic Automata for Text Segmentation (GNATS)". Science of Artificial Neural Networks. ...
The Colt Car Company UK (who distribute Mitsubishi Motors) are in Cirencester, and Corin Group make artificial joints on the ... which in 2002 was the world's first production site of membrane electrode assemblies, and next door is Neptune, who make ... Sir Arthur C. Clarke of Minehead invented the idea of artificial satellites; he sent a letter to Harry Wexler who then ... "artificial" construct. The large area of the region, stretching as it does from the Isles of Scilly to Gloucestershire, ...
Artificial Reef Society of British Columbia. *CMAS Europe. *Coral Reef Alliance. *Diving Equipment and Marketing Association ... Membrane gas separation. *Pressure swing adsorption. *Oxygen analyser *Electro-galvanic oxygen sensor ...
Bark extracts of Lannea coromandelica caused lysis of cell membranes followed by fragmentation of cellular materials. ...
Mucus also covers the olfactory epithelium, which contains mucous membranes that produce and store mucus and olfactory glands ... The primary components of the layers of epithelial tissue are the mucous membranes, olfactory glands, olfactory neurons, and ...
A cell membrane isolates the inside of the cell from its environment. Neurons do not communicate via direct cytoplasm to ... Blue Brain Project and Artificial brain. *International Consortium for Brain Mapping see Brain Mapping ...
This is problematic for some organisms with pervious skins or with gill membranes, whose cell membranes may burst if excess ... These artificial resources are based on the use of energy, infrastructure and human expertise, but are potential solutions to ...
While the sting can also penetrate the membranes between joints in the exoskeleton of other insects (and is used in fights ...
Dr. Lamaze was influenced by childbirth practices in the Soviet Union, which involved breathing and relaxation techniques under the supervision of a "monitrice", or midwife. The Lamaze method gained popularity in the United States after Marjorie Karmel wrote about her experiences in her 1959 book Thank You, Dr. Lamaze, and with the formation of the American Society for Psycho prophylaxis in Obstetrics (ASPO Lamaze). Currently Lamaze International, founded by Karmel and Elisabeth Bing,[2] is the premier childbirth education certifying organization in the world.. Modern Lamaze childbirth classes teach expectant mothers many ways to work with the labor process to reduce the pain associated with childbirth and promote normal (physiological) birth including the first moments after birth. Techniques include allowing labour to begin on its own, movement and positions, massage, aromatherapy, hot and cold packs, breathing techniques, the use of a "birth ball" (yoga or exercise ball), spontaneous pushing, ...
membrane potential. When a nerve or muscle cell is at "rest", its membrane potential is called the resting membrane potential. ... artificial selection. Also called selective breeding.. The process by which humans use animal breeding and plant breeding to ... cell membrane. The semipermeable membrane surrounding the cytoplasm of a cell.. cell nucleus. The "control room" for the cell. ... mucous membrane. A membrane that lines various cavities in the body and covers the surface of internal organs.. multicellular. ...
... s are described as being photovoltaic, irrespective of whether the source is sunlight or an artificial light. They ... June 2012). "Efficient Light Trapping in Inverted Nanopyramid Thin Crystalline Silicon Membranes for Solar Cell Applications". ...
Underlying the mucous membrane in the mouth is a thin layer of smooth muscle tissue and the loose connection to the membrane ... The mucous membrane in the mouth continues as the thin mucosa which lines the bases of the teeth. The main component of mucus ... Most of the oral cavity is lined with oral mucosa, a mucous membrane that produces a lubricating mucus, of which only a small ... Mucous membranes vary in structure in the different regions of the body but they all produce a lubricating mucus, which is ...
The vRNA and viral core proteins leave the nucleus and enter this membrane protrusion (step 6). The mature virus buds off from ... or artificial) UV radiation. This could explain why influenza occurs mostly in winter and during the tropical rainy season, ... One observer wrote, "One of the most striking of the complications was hemorrhage from mucous membranes, especially from the ... the cell in a sphere of host phospholipid membrane, acquiring hemagglutinin and neuraminidase with this membrane coat (step 7). ...
Glycans serve a variety of structural and functional roles in membrane and secreted proteins.[1] The majority of proteins ... NetNGlyc: The NetNglyc server predicts N-glycosylation sites in human proteins using artificial neural networks that examine ...
Artificial Reef Society of British Columbia. *CMAS Europe. *Coral Reef Alliance. *Diving Equipment and Marketing Association ...
Vagina Human fertilization Assisted reproductive technology Artificial insemination Fertility medication In vitro fertilisation ... Childbirth positions Contraction Presentation Breech birth Cephalic presentation Shoulder presentation Rupture of membranes ...
... capable of controlling the movements of an artificial limb, are attached to the severed nerve-endings of the patient. The ... Source containing the rest of the work found on this article Department of Membrane and Neurophysics at the Max-Planck- ...
In the late 1980s, keyboards in the synth lab at Berklee College of Music were equipped with membrane thin ribbon style ... buzz-saw-like artificial bass sounds, by generating and combining signals of different frequencies. Bass synth patches may ... who in the early 1970s utilized synthesizers to create new artificial sounds (rather than simply mimicking real instruments[38] ...
Membranes offer the advantage over rigid structures of being compliant and low mass, which can produce more direct coupling ... Environmental concerns include minor risk of collision, artificial reefing near the fixed point, EMF effects from subsea cables ... Bombora Wave Power[43] is based in Perth, Western Australia and is currently developing the mWave[44] flexible membrane ... Submerged pressure differential converters frequently use flexible membranes as the working surface between the ocean and the ...
Artificial Reef Society of British Columbia (ARSBC). *CMAS Europe. *Diving Equipment and Marketing Association (DEMA) ... Membrane method of gas concentration. *Pressure swing adsorption. *Oxygen analyser. *Oxygen compatibility ...
C. diphtheriae causes membrane formation in conjunctiva of unimmunized children.[7] Chemical[edit]. Chemical eye injury may ... and artificial tears sometimes relieve discomfort in mild cases. In more severe cases, nonsteroidal anti-inflammatory ... Cases of bacterial conjunctivitis that involve the production of membranes or pseudomembranes are associated with Neisseria ... Bacterial conjunctivitis may cause the production of membranes or pseudomembranes that cover the conjunctiva. Pseudomembranes ...
Sepe, S. M.; Clark, R. A. (March 1985). "Oxidant membrane injury by the neutrophil myeloperoxidase system. I. Characterization ... "Artificial radioactive tracers". Detection and prevention of leaks from dams. Taylor & Francis. pp. 179-181. ISBN 978-90-5809- ...
High potassium concentrations in the plasma cause depolarization of the zona glomerulosa cells' membranes in the outer layer of ... often generating artificial stresses if the "natural" level of stress is not enough.[70] ... where the chief cells sense the Ca2+ level by means of specialized calcium receptors in their membranes. The sensors for the ... but this time from the mucous membranes of the throat and mouth. ...
The membrane has no hair follicles or sweat glands, except between the fingers.[54][56] For bat embryos, apoptosis (cell death ... Many people put up bat houses to attract bats.[230] The 1991 University of Florida bat house is the largest occupied artificial ... This skin membrane consists of connective tissue, elastic fibres, nerves, muscles, and blood vessels. The muscles keep the ... The patagium is the wing membrane; it is stretched between the arm and finger bones, and down the side of the body to the hind ...
Membrane lipids. The most common red blood cell membrane lipids, schematically disposed as they are distributed on the bilayer ... It is hoped that these artificial red blood cells can eventually be used for blood transfusions.[50] ... Their membrane plays many roles in this. These functions are highly dependent on the membrane composition. The red blood cell ... likely enabling the red cell to maintain its favorable membrane surface area by preventing the membrane from collapsing ( ...
Alum adheres to the cell's plasma membrane and rearranges certain lipids there. Spurred into action, the DC picks up the ... Artificial induction of immunity / Immunization: Vaccines, Vaccination, Infection, Inoculation (J07). Development. *Adjuvants ... that are expressed on the membranes of leukocytes including dendritic cells, macrophages, natural killer cells, cells of the ...
... are solid-phase-membrane-mimetics.1Synthesis of IAM particles entails bonding cell membrane lipid molecules to solid surfaces ... Immobilized artificial membrane chromatography: supports composed of membrane lipids. Anal. Biochem. 176: 36-47.PubMedCrossRef ... Immobilized artificial membranes (IAM) are solid-phase-membrane-mimetics.1 Synthesis of IAM particles entails bonding cell ... Chae WG., Luo C., Rhee D.M., Lombardo C.R., Low P., Pidgeon C. (1991) Immobilized Artificial Membrane Chromatography. In: ...
The cell membrane is one of the most important components of a cell because it separates the interior from the environment and ... UCSD Researchers Create Artificial Cell Membrane 54 Posted by Unknown Lamer on Tuesday January 31, 2012 @04:11AM. from the sr- ... and Harvard University have created artificial self-assembling cell membranes using a novel chemical reaction. The chemists ... In a move that brings mankind another step closer to being able to create artificial life forms from scratch, chemists from the ...
... membranes artificial include Giant Liposome Preparation for Imaging and Patch-Clamp Electrophysiology. ... Membranes, Artificial: Artificially produced membranes, such as semipermeable membranes used in artificial kidney dialysis ( ... monomolecular and bimolecular membranes used as models to simulate biological Cell membranes. These membranes are also used in ...
Single-particle tracking of murine polyoma virus-like particles on live cells and artificial membranes. Helge Ewers, Alicia E. ... 7c). It was apparent that VLPs were slightly more mobile in these artificial membranes than during free diffusion in the 3T6 ... Single-particle tracking of murine polyoma virus-like particles on live cells and artificial membranes ... Preparation of Artificial Lipid Bilayers. Artificial lipid bilayers were prepared by the vesicle drop method (23). Briefly, ...
Modulation of the molecular arrangement in artificial and biological membranes by phospholipid-shelled microbubbles.. Carugo D1 ... The transfer of material from phospholipid-coated microbubbles to cell membranes has been hypothesized to play a role in ... Our results indicate that transfer of phospholipids alters the organization of molecules in cell membranes, specifically the ... In this study, we employed quantitative fluorescence microscopy techniques to investigate this phenomenon in both artificial ...
... in which their interaction forms a solid membrane ... Artificial Membrane Sacks as Mini Stem Cell Labs. March 27th, ... which have a solid membrane on the outside and liquid inside, and flat membranes of any shape. The researchers can make the ... "We expected them to mix, but, much to our surprise, they formed a solid membrane instantly on contact. This was an exciting ... in which their interaction forms a solid membrane that seems to be quite suited for creation of small sacs to host all kinds of ...
In this way, artificial enzyme membranes or at least artificial immobilization of the enzymes could be a mean to study this ... For artificial enzyme membranes, due to the well-defined context it is possible to write in a simple way equations ruling the ... Kernevez J.P., Thomas D. (1975) Numerical analysis of artificial enzyme membrane - Hysteresis, oscillations and spontaneous ... THOMAS, D. and CAPLAN, S.R., in "Membrane Separation Processes", Ed. Meares P. Elsevier Publishing Co. Amsterdam (1974).Google ...
Natural channel proteins are integrated into artificial membranes to facilitate the transport of ions and molecules. ... How natural channel proteins move in artificial membranes. (Nanowerk News) Natural channel proteins are integrated into ... In essence, however, the behavior of the channel proteins in the artificial membranes is comparable to that in their natural ... Natural channel proteins move sideways in a thick artificial membrane that condenses around the channel proteins. (© ACS) ...
Semipermeable Polyurethane Membrane as an Artificial Skin for the Premature Neonate. Alison Knauth, Margaret Gordin, Wendy ... Semipermeable Polyurethane Membrane as an Artificial Skin for the Premature Neonate. Alison Knauth, Margaret Gordin, Wendy ... Semipermeable Polyurethane Membrane as an Artificial Skin for the Premature Neonate Message Subject (Your Name) has sent you a ... Semipermeable Polyurethane Membrane as an Artificial Skin for the Premature Neonate. Alison Knauth, Margaret Gordin, Wendy ...
... lipid rafts in binary lipid/cholesterol membranes; membrane assembly and lipid rafts in the cell and artificial membranes; the ... Membrane Assembly and Lipid Rafts in the Cell and Artificial Membranes: Effect of Lipid Peroxidation. (Angel Catalá, Instituto ... Membrane Organization and Lipid Rafts in the Cell and Artificial Membranes. $190.00. ... This book presents an overview of membrane organization and lipid rafts in the cell and artificial membranes. The topics ...
Artificial rupture of membranes (AROM), also known as an amniotomy, is performed by a midwife or obstetrician and was once ... In one study comparing amnihook versus amnicot for artificial rupture of membranes, use of an amnicot was associated with fewer ... The different techniques for artificial rupture of membranes have not been extensively compared in the literature. ... The membranes can be ruptured using a specialized tool, such as an amnihook or amnicot, or they may be ruptured by the ...
Artificial neural membrane (ANM) refers to a new class of functional structure developed through research adaptive and ... Artificial neural membrane technology development has been funded by the NASA Institute for Advanced Concepts, for application ... ARTIFICIAL NEURAL MEMBRANE FLAPPING WING (PDF) Aerospace Research Systems, Inc. NASA NASA Institute for Advanced Concepts. ... Currently Aerospace Research Systems, Inc - the agency that pioneered work in developing artificial neurons for use in control ...
Although there is much to suggest that biological membranes have a lipoprotein character, their actual composition and ... Mercer E.H. (1960) Artificial models of biological membranes. In: Bargmann W., Möllenstedt G., Niehrs H., Peters D., Ruska E., ... The electron microscopic image of these membranes is usually a thin, dense line splitting at higher resolution into two ; but ... Although there is much to suggest that biological membranes have a lipoprotein character, their actual composition and ...
We discuss the figures of merit for conducting membranes in artificial photosynthetic systems and describe an electronically ... Designing electronic/ionic conducting membranes for artificial photosynthesis. Energy and Environmental Science, 4 (5). pp. ...
"Layer-by-layer membrane assembly allows us to create synthetic cells with membranes of arbitrary complexity at the molecular ... "We can now control the molecular composition of the inner and outer layers of a bilayer membrane, and even assemble multi- ... The study, "Layer-by-layer Cell Membrane Assembly," was supported by a National Institutes of Health Pathway to Independence ... Understanding the myriad biochemical roles of membranes requires the ability to prepare synthetic versions of these complex ...
Successful artificial photosynthesis is significant for future human/robotic exploration and terrestrial carbon emissions ... High-Efficiency Artificial Photosynthesis Using a Novel Alkaline Membrane Cell. Successful artificial photosynthesis is ... High-Efficiency Artificial Photosynthesis Using a Novel Alkaline Membrane Cell. (reference NPO-45777) is currently available ... The heart of the reactor is a membrane cell fabricated from an alkaline polymer electrolyte membrane and catalyst-coated ...
EP0107055B1 - Artificial organs or membranes for medical use - Google Patents. Artificial organs or membranes for medical use ... 1. Hydrogel having increased mechanical strength for medical use as an artificial organ or an artificial membrane, said ... EP19830109491 1982-09-24 1983-09-23 Artificial organs or membranes for medical use Expired EP0107055B1 (en) Priority ... It is a primary object of the present invention to provide a hydrogel for material use as an artificial organ or an artificial ...
... is a screening tool for the evaluation of drug permeability across various biological membrane systems in a microplate format. ... The method employs the use of a fluorescent artificial receptor (FAR), composed of a macrocycle in combination with an ... is a screening tool for the evaluation of drug permeability across various biological membrane systems in a microplate format. ... The method employs the use of a fluorescent artificial receptor (FAR), composed of a macrocycle in combination with an ...
A patients own white cells could be harvested and used to create personalized LLVs By cloaking nanoparticles in the membranes ...
... June 30, 2014, Albert Ludwigs ... Membrane proteins: Communicating with the world across the border. May 15, 2014 All living cells are held together by membranes ... The team discovered that a positive charge travels through the membrane: The membrane proteins do not transport the gas ammonia ... Biological membranes are like a guarded border. They separate the cell from the environment and at the same time control the ...
Home Medical Breakthroughs Penn Researchers Develop Custom Artificial Membranes to Study the Molecular Basis of Disease ... Penn Researchers Develop Custom Artificial Membranes to Study the Molecular Basis of Disease. ... For decades, these challenges hindered scientific efforts to create artificial membranes for research. ... when Percecs lab devised a way of programming artificial membranes with a precise number and spatial arrangement of sugars. ...
Nanoscaled Tip Writes Artificial Cell Membranes. Biomimetic Membranes on Graphene Open up Novel Applications in Biotechnology ... Aravind Vijayaraghavan from the University of Manchester have developed a new method to produce artificial membranes: Using a ... The resulting biomimetic membranes, i.e. membranes simulating biological structures, allow for the specific investigation of ... now presents a new method to produce biomimetic membranes: They write tailored patches of phospholipid membrane onto a graphene ...
The paracellular pathway prediction model based on Renkin function (PP-RF) was combined with a bio-mimetic artificial membrane ... of this study was to construct and examine the prediction model for total passive permeation through the intestinal membrane. ... The paracellular pathway prediction model based on Renkin function (PP-RF) was combined with a bio-mimetic artificial membrane ... Prediction of passive intestinal absorption using bio-mimetic artificial membrane permeation assay and the paracellular pathway ...
A process for preparing an artificial biological membrane in which an aqueous solution containing 6 wt % or more of polyvinyl ... US4808353A - Process for preparing an artificial biological membrane - Google Patents. Process for preparing an artificial ... US06816966 1982-09-24 1986-01-08 Process for preparing an artificial biological membrane Expired - Fee Related US4808353A (en) ... A process for preparing an artificial biological membrane in which an aqueous solution containing 6 wt % or more of polyvinyl ...
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Finally, these biotin-tagged membrane proteins are interconnected with streptavidin (SA) to form an artificial protein network ... Artificial Formation and Tuning of Glycoprotein Networks on Live Cell Membranes: A Single-Molecule Tracking Study. In: ... For this, membrane glycans are first metabolically labeled with azido sugars and then tagged with biotin by copper-free click ... We present a method to artificially induce network formation of membrane glycoproteins and show the precise tuning of their ...
An artificial neural network was trained on databases of 102 membrane proteins and 3499 soluble proteins. Prediction accuracies ... We introduce a predictor that is able to identify trans-membrane spans from the sequence of a protein. The novelty of the ... Tools for the identification of trans-membrane spans from the protein sequence are widely used in the experimental community. ... structural biology seeks to increase the prediction accuracy of such methods since they represent a first step towards membrane ...
Conductance Properties of Artificial Lipidic Membranes Containing a Proteolipid from Electrophorus Mario Parisi, Tomás A. ... Conductance Properties of Artificial Lipidic Membranes Containing a Proteolipid from Electrophorus Mario Parisi, Tomás A. ... These results suggest that this special proteolipid, when added to the artificial membranes, induces a "chemical excitability" ... This proteolipid has now been incorporated into ultrathin lipidic membranes, and the membrane resistance was studied. The ...
Cofactor Regeneration in Artificial Enzyme Membranes: Potentialities for Analytical and Reactor Applications. ... Legoy M.D., Thomas D. (1978) Cofactor Regeneration in Artificial Enzyme Membranes: Potentialities for Analytical and Reactor ... THOMAS, D. and CAPLAN, S.R. In "Membrane Separation Processes" (Ed. P. Meares) Elsevier, Amsterdam, 1975.Google Scholar ... In this technique alcohol dehydrogenase (ADH) and NAD were immobilized together in a protein membrane by a previously described ...
Delayed delivery after artificial rupture of membrane. ICD-10-CM O75.5 is grouped within Diagnostic Related Group(s) (MS-DRG v ... Delayed delivery after artificial rupture of membranes. 2016 2017 2018 Billable/Specific Code Maternity Dx (12-55 years) Female ...
  • 6,7 ), and the purification of other membrane proteins. (springer.com)
  • 8 Although both non-chromatographic and chromatographic applications are evolving, the most useful application (s) of IAM will be for the purification of membrane proteins. (springer.com)
  • Nanowerk News ) Natural channel proteins are integrated into artificial membranes to facilitate the transport of ions and molecules. (nanowerk.com)
  • As reported in academic journal Nano Letters ( 'Dynamics of Membrane Proteins within Synthetic Polymer Membranes with Large Hydrophobic Mismatch' ), the results may prove useful to the ongoing development of new applications such as nanoreactors and artificial organelles. (nanowerk.com)
  • The membranes of the cells in our bodies are only approximately 4 to 5 nanometers thick and consist of a complex mixture of lipids and specific membrane proteins, which also include channel proteins. (nanowerk.com)
  • Chemists at the National Center of Competence in Research (NCCR) Molecular Systems Engineering working under Professor Wolfgang Meier and Professor Cornelia Palivan from the University of Basel have now integrated three different channel proteins into artificial membranes of 9 to 13 nanometers in thickness and have measured their movements for the first time. (nanowerk.com)
  • All three channel proteins were able to move freely within the membranes of various thicknesses this took up to ten times longer than in the lipid bilayers of their natural environment. (nanowerk.com)
  • In thicker membranes, the building blocks of the membrane (polymers) must be able to condense around the channel proteins in order to alter their fixed size. (nanowerk.com)
  • In essence, however, the behavior of the channel proteins in the artificial membranes is comparable to that in their natural environment, the lipid bilayer, with the time scale of the movements being approximately ten times lower. (nanowerk.com)
  • Proteins of the Amt family transport ammonium across the lipid membrane of the cell. (phys.org)
  • What was previously known is that Amt proteins extend across cellular membranes where they specifically transport the nitrogen into bacteria and plant cells, essential nutrient for their growth and survival. (phys.org)
  • A team of scientists led by Prof. Dr. Susana Andrade from the Institute of Biochemistry of the University of Freiburg and the Cluster of Excellence BIOSS Centre for Biological Signalling Studies has now determined the transport properties of Amt proteins with great precision on the basis of electrophysiology tests on artificial lipid systems. (phys.org)
  • The scientists cloned the membrane proteins from an archaea, a microorganisms that lives under extreme temperature conditions and isolate them. (phys.org)
  • The team discovered that a positive charge travels through the membrane: The membrane proteins do not transport the gas ammonia NH3 but rather the ammonium ion NH4+. (phys.org)
  • The researchers tested three Amt proteins that are present in the bacteria and also determined the speed with which they allow ammonium to pass through the membrane. (phys.org)
  • Transport proteins are responsible for moving materials such as nutrients and metabolic products through a cell's outer membrane, which seals and protects all living cells, to the cell's interior. (phys.org)
  • One of the most important roles membrane sugars play is receiving messages from signaling proteins and communicating those messages to the cell. (healthcanal.com)
  • These cell membranes contain numerous proteins, ion channels, and other biomolecules, each performing vital functions. (kit.edu)
  • It is planned to design sensors that react to the binding of proteins by a change of conductivity as well as sensors detecting the function of ion channels in membranes. (kit.edu)
  • Ion channels are pore-forming proteins via which electrically charged particles can cross the membrane. (kit.edu)
  • Finally, these biotin-tagged membrane proteins are interconnected with streptavidin (SA) to form an artificial protein network in analogy to a lectin-induced lattice. (uni-muenchen.de)
  • The degree of network formation can be controlled by the concentration of SA, its valency, and the concentration of biotin on membrane proteins. (uni-muenchen.de)
  • An artificial neural network was trained on databases of 102 membrane proteins and 3499 soluble proteins. (sciweavers.org)
  • Abstract  The non-bilayer lipid monogalactosyldiacylglycerol (MGDG) is the most abundant type of lipid in the thylakoid membrane and plays an important role in regulating the structure and function of photosynthetic membrane proteins. (ebscohost.com)
  • The artificial cell membranes (ACMs) are customised synthetic cell membranes that mimic live, targeted membrane proteins and which can be tailor-made to a pharmaceutical company's specific drug testing requirements, can be produced rapidly and are stable over a long period, leading to significantly reduced costs and streamlining of the currently tedious and cumbersome drug discovery process. (a-star.edu.sg)
  • Importantly, this will enable investigators to create drugs that target the cell membrane and its proteins more effectively, as well as aid in developing a deeper understanding of membrane dysfunction due to disease. (labroots.com)
  • One exciting application would be to probe the behavior of bound and integral membrane proteins in response to shifts in membrane composition," suggested Roberto Brea, the lead author of the study and a postdoctoral fellow in the Devaraj lab. (labroots.com)
  • Integral membrane proteins are extremely important and common drug targets and we need a way to understand their behavior in lipid bilayers. (labroots.com)
  • Membrane proteins are important drug targets in many human diseases and gathering structural information regarding these proteins encourages the pharmaceutical industry to develop new molecules using structure-based drug design studies. (biomedcentral.com)
  • This experimental procedure highlights the potential role of chemical chaperones such as DMSO in improving yields of recombinant membrane proteins with a different topology than G-coupled receptors. (biomedcentral.com)
  • Finally, the proposed ANN shows that the manipulation of classic fermentation parameters coupled with the addition of specific molecules can open and reinforce new perspectives in the optimization of P. pastoris bioprocesses for membrane proteins biosynthesis. (biomedcentral.com)
  • The membrane channels reject polyethylene glycol with a molecular size of 10 kg mol−1, but are permeable to proteins, such as lysozyme (14.3 kg mol−1) and cytochrome c (12.4 kg mol−1), due to the right balance of hydrogen bond interactions along the channels, electrostatic attraction, as well as the right pore sizes. (edu.sa)
  • In this context, membrane-bound proteins are of special interest since they constitute a third of our genome and represent the target of half of the most common medical drugs. (chalmers.se)
  • Artificial cell membrane platforms are the known best candidates which "mimics" the natural environment for membrane proteins. (biomimeticsgroup.com)
  • Natural channel proteins move sideways in a thick artificial membrane that condenses around the channel proteins. (chemeurope.com)
  • Such systems combine natural proteins that present high water conductance states under natural conditions with artificial lipidic or polymeric matrices. (rsc.org)
  • Here, we demonstrate that SAUR proteins provide a mechanistic link between auxin and plasma membrane H + -ATPases ( PM H + -ATPases) in Arabidopsis thaliana . (plantcell.org)
  • This huge membrane-spanning vesicular protein is different from other transport proteins and is instrumental in carrying hydrophilic molecules, notably vitamin B12 or cobalamin, across the cell membrane. (news-medical.net)
  • The laboratory directed by Arne Skerra, Professor of Biological Chemistry, has its focus on designing artificial binding proteins for therapeutic applications. (news-medical.net)
  • The PhD student will use and develop such tools to study the biophysics of lipid bilayers and the activity of proteins interacting with lipid membrane. (jobbird.com)
  • Conventional lysosomes in many cells types respond to elevations in cytosolic Ca 2+ by fusing with the plasma membrane ( 9 ), in a process mediated by specific soluble N -ethylmaleimide-sensitive factor attachment protein receptor proteins ( 10 ), and regulated by the Ca 2+ -binding protein synaptotagmin VII ( 11 , 12 ). (pnas.org)
  • Membrane proteins represent one of the most important targets for pharmaceutical companies. (leedsbeckett.ac.uk)
  • This review summarizes some of the current techniques used for studying membrane proteins, with overall advantages and drawbacks for each method. (leedsbeckett.ac.uk)
  • These membrane compartments appear to store transport proteins before use. (phys.org)
  • Our droplet hydrogel bilayer system is an artificial bilayer system for interrogating membrane proteins, but it also allows us to explore new forms of synthetic biology where we can add individual protein function to a droplet, such as touch sensitivity or light sensitivity. (edu.au)
  • Using a novel DNA origami structure we can protect and controllably release our blocking DNA structures, known as DNA caltrops, to regulate the insertion of membrane proteins into these droplets. (edu.au)
  • Parallel artificial membrane permeability assay (PAMPA) is a screening tool for the evaluation of drug permeability across various biological membrane systems in a microplate format. (frontiersin.org)
  • For more results try searching for Parallel Artificial Membrane Permeability Assay (PAMPA) across all experimental services. (scienceexchange.com)
  • Parallel Artificial Membrane Permeability Assay (PAMPA) is a cell-free permeation model used to predict passive drug transport. (creative-bioarray.com)
  • Immobilized artificial membrane chromatography: supports composed of membrane lipids. (springer.com)
  • Fourier transform infrared assay of membrane lipids immobilized to silica: leaching and stability of immobilized artificial membrane-bonded phases. (springer.com)
  • The scientists engineered a microfluidic device containing an array of microscopic cups, each trapping a single droplet of water bathed in oil and lipids, the molecules that make up cellular membranes. (healthcanal.com)
  • Lipids (from Greek lipos, "fat") are central structural elements of cell membranes. (kit.edu)
  • The human body contains about 100 trillion cells, each of which is enveloped in a cell membrane which essentially is a double layer of partly hydrophilic, partly hydrophobic phosphorus-containing lipids. (kit.edu)
  • According to Dr. Aravin Vijayaraghavan from the University of Manchester, the lipids applied onto graphene spread uniformly, thus forming high-quality membranes. (kit.edu)
  • When the lipids contain the corresponding binding sites, such as biotin, the membranes actively bind streptavidin, a protein produced by certain bacteria and used in various biotechnological methods. (kit.edu)
  • The researchers around Hirtz will use their biomimetic membranes in the future to construct novel biosensors based on graphene and lipids. (kit.edu)
  • When incubated with liposomes composed of total lipids from the human erythrocyte membrane, CEL-III efficiently induced the leakage of carboxyfluorescein (CF) trapped in the vesicles, suggesting the presence of its receptor in the membrane lipids. (ebscohost.com)
  • Interaction of a dental filling material eluate and membrane lipids. (ebscohost.com)
  • In this video from the lab of Neal Devaraj, the lipids in their synthetic membrane can be seen undergoing spontaneous remodeling. (labroots.com)
  • The scientists are close to replicating natural cell membranes, normally composed of sheets of lipids. (labroots.com)
  • In our latest study, we show that reversible chemical reactions can be harnessed to achieve spontaneous remodeling of lipids in synthetic membranes," he continued. (labroots.com)
  • Many other scientists have exploited the ability of lipids to self-assemble into bilayer vesicles with properties reminiscent of cellular membranes, but until now no one has been able to mimic nature's ability to support persistent phospholipid membrane formation,' he explained. (timesnownews.com)
  • The scientists used a technique called lipid dip-pen nanolithography to uniformly spread lipids across the graphene surface, creating a realistic membrane model with many of the characteristics associated with the real thing. (fiercepharma.com)
  • BioAssay Systems' PAMPA Kit provides all the necessary components to run a Parallel Artificial Permeability Assay. (bioassaysys.com)
  • Dynamic events at the plasma membrane of live cells are commonly studied with light microscopy and single-particle tracking (SPT) after labeling of specific membrane components with individual fluorophores, colloidal gold, or fluorescent beads ( 1 - 3 ). (pnas.org)
  • Thorough analysis of the trajectories thus obtained provides information about the lateral mobility of membrane components and about the constraints imposed on them by cytoskeletal elements ( 4 - 6 ), cholesterol-rich microdomains ( 7 , 8 ), and other structures that impose heterogeneity in the plasma membrane. (pnas.org)
  • In this report we demonstrate that the human plasma membrane protein DARC can be used as an artificial anchor molecule in cell surface engineering applications. (biomedcentral.com)
  • The SNAP-tag® served as an example for a molecular-technological developed protein that is artificially attached to the extracellular side of the plasma membrane through our DARC-anchor. (biomedcentral.com)
  • In this work, we examined whether the human plasma membrane protein DARC [ 4 ] can act as such a nanobiotechnological polypeptide anchor fused with a functional peptide of interest. (biomedcentral.com)
  • Plasma membrane resealing is a Ca 2+ -dependent process that involves the exocytosis of intracellular vesicles next to the wound site. (pnas.org)
  • These findings raised the possibility that the complex pathology of lysosomal diseases might also include defects in plasma membrane repair. (pnas.org)
  • Thus, the severe symptoms exhibited by CHS patients may also include defects in the ability of cells to repair plasma membrane lesions. (pnas.org)
  • Modulation of synaptotagmin VII function through dominant-negative or gene knock-out approaches revealed a role for lysosomal exocytosis in the repair of plasma membrane lesions ( 12 , 13 ). (pnas.org)
  • Given that most cells from CHS patients and beige-J mice have enlarged lysosomes ( 2 ), these findings suggested that lysosome-mediated plasma membrane repair might also be compromised in cells carrying this mutation. (pnas.org)
  • The cell membrane (also called the plasma membrane or plasmalemma ) is the biological membrane separating the interior of a cell from the outside environment. (phys.org)
  • The plasma membrane also serves as the attachment point for both the intracellular cytoskeleton and, if present, the extracellular cell wall. (phys.org)
  • 1 Synthesis of IAM particles entails bonding cell membrane lipid molecules to solid surfaces at high molecular surface densities. (springer.com)
  • Our results indicate that transfer of phospholipids alters the organization of molecules in cell membranes, specifically the lipid ordering or packing, which is known to be a key determinant of membrane mechanical properties, protein dynamics, and permeability. (nih.gov)
  • At Northwestern University researchers discovered an interesting relationship between two molecules, in which their interaction forms a solid membrane that seems to be quite suited for creation of small sacs to host all kinds of cells in biological solutions, including possibly stem cells. (medgadget.com)
  • Using just these two molecules, Stupp and his team can make many different structures, the two most important being sacs, which have a solid membrane on the outside and liquid inside, and flat membranes of any shape. (medgadget.com)
  • Percec's new study demonstrates how researchers can use this membrane model to examine the interactions of cell surfaces with other biological molecules, with far ranging applications in medicine, biochemistry and biophysics. (healthcanal.com)
  • Cell membranes are composed of two layers of fatty molecules known as phospholipids, each of which has a water-loving head and a water-repellant tail. (healthcanal.com)
  • Cells utilize enzymatic methods to constantly remodel and adjust their membranes, which has a effects on the other molecules in the area. (labroots.com)
  • Cell membranes can be engineered by attaching new molecules or by modifying or removing their natural components. (biomedcentral.com)
  • Disclosed is an artificial membrane comprising a product made by cross-linking molecules of interpenetrating denatured collagen coupled at their lysine epsilon amino groups with a coupler through carbonyl groups, sulfonyl groups, or combination thereof on the coupler wherein non-coupled lysine epsilon. (google.com)
  • Disclosed is an artificial membrane comprising a product made by cross-linking molecules of interpenetrating denatured collagen coupled at their lysine epsilon amino groups with a coupler through carbonyl groups, sulfonyl groups, or combination thereof on the coupler wherein non-coupled lysine epsilon amino groups are bonded to a modifier wherein the modifier is a carbonyl sulfonyl, carbamoyl, or β-malic acid group. (google.com)
  • 2. The membrane of claim 1 wherein cross-linking is effected by reacting the molecules with a polyfunctional amine reactive agent selected from the group consisting of a carboxylic acid halide, sulfonyl halide, anhydride, reactive ester, and aldehyde. (google.com)
  • 3. The membrane of claim 1 wherein cross-linking is effected by exposing the molecules to actinic radiation. (google.com)
  • 4. The membrane of claim 1 wherein cross-linking is effected by dehydrating a gel containing the molecules. (google.com)
  • 12. The membrane of claim 1 wherein the molecules were denatured by heating in aqueous media to a temperature between about 40 and 120 C. and thereafter cooling. (google.com)
  • 13. An artificial membrane comprising a product made by cross-linking molecules of interpenetrating denatured collagen coupled at their lysine epsilon amino groups with a coupler through carbonyl groups, sulfonyl groups, or combination thereof on the coupler. (google.com)
  • 16. The membrane of claim 13 wherein cross-linking is effected by dehydrating the molecules. (google.com)
  • This study demonstrates the feasibility of such experiments with PLBs, amenable to physical constraints, and thus offers new opportunities for systematic studies of structure-function relationships in membrane-associating molecules. (biomedcentral.com)
  • Current pharmacological models for determining affinity and kinetics of drugs for membrane receptors assume the interacting molecules are homogeneously distributed in the bulk aqueous phase. (aspetjournals.org)
  • Tiny light-collecting particles can be embedded on a membrane to absorb energy and split carbon dioxide and water molecules. (newscientist.com)
  • The paracellular pathway prediction model based on Renkin function (PP-RF) was combined with a bio-mimetic artificial membrane permeation assay (BAMPA), which is an in vitro method to predict transcellular pathway permeation, to construct the prediction model (BAMPA-PP-RF model). (nih.gov)
  • By using a sensitive electroporation/fluorescence-activated cell sorter-based assay, we show that lysosomal exocytosis triggered by membrane wounding is impaired in both human Chediak-Higashi and mouse beige-J fibroblasts. (pnas.org)
  • The PAMPA assay for permeability measurement is based on the diffusion of a compound of interest through an artificial membrane. (creative-bioarray.com)
  • The method for labeling of inner membrane leaflet in unilamellar giant POPC vesicles was developed and characterised. (ebscohost.com)
  • The work in this thesis was designed to investigate the effects of HCP on mitochondrial membranes, lipid vesicles, and lipid bilayer membranes and their relation to the above toxic effects. (oregonstate.edu)
  • used a technique that allows us to visualize morphological changes of the membrane of giant more-component unilamellar vesicles upon pressure perturbation. (taylorfrancis.com)
  • Recently, several studies demonstrated the ability to generate a large number of membrane vesicles from cultured cells treated with a drug, Cytochalasin B. This cost-effective approach permits the generation of large quantities of extracellular vesicles. (kpfu.ru)
  • To address this, an international team of investigators, led from Kazan Federal University, Russia by Professor Albert Rizvanov , with international collaborators, characterized the biological activity of membrane vesicles. (kpfu.ru)
  • The lead author, Dr. Marina Gomzikova , and colleagues described the morphology, molecular composition, fusion capacity and biological activity of Cytochalasin B-induced membrane vesicles (CIMVs). (kpfu.ru)
  • Cytochalasin B-induced membrane vesicles convey angiogenic activity of parental cells. (kpfu.ru)
  • Modulation of the molecular arrangement in artificial and biological membranes by phospholipid-shelled microbubbles. (nih.gov)
  • The transfer of material from phospholipid-coated microbubbles to cell membranes has been hypothesized to play a role in ultrasound-mediated drug delivery. (nih.gov)
  • The simplest form of a membrane, called a liposome or vesicle, will self-assemble when its phospholipid building blocks are placed in water. (healthcanal.com)
  • Researchers around Dr. Michael Hirtz from Karlsruhe Institute of Technology and Dr. Aravind Vijayaraghavan from the University of Manchester have developed a new method to produce artificial membranes: Using a nanoscaled tip, they write tailored patches of phospholipid membrane onto a graphene substrate. (kit.edu)
  • We present a microfluidic device hosting TXTL reactions of a reporter gene in thousands of microwells separated from an external buffer by a phospholipid membrane. (elsevier.com)
  • Nutrients in the external solution feed the TXTL reaction at the picoliter scale via passive transport across the phospholipid membrane of each microfluidic well, despite the absence of pores. (elsevier.com)
  • The phospholipid membrane can, however, provide a second compartment into which drugs can partition, particularly lipophilic/basic compounds. (aspetjournals.org)
  • 1-4 Thus IAM surfaces are intended to mimic the lipid environment of cell membranes and consequently the initial applications of IAM particles relate to endogenous solute-membrane interactions. (springer.com)
  • A new cell designed to mimic the photosynthetic processes of plants to convert carbon dioxide into carbonaceous products and oxygen at high efficiency, has an improved configuration using a polymer membrane electrolyte and an alkaline medium. (techbriefs.com)
  • Early efforts to mimic membrane surfaces in the lab were crude and simplistic, with no control over the number or distribution of sugars. (healthcanal.com)
  • up to this point, no one has invented a straightforward way to make make membranes that are able to mimic lipid remodeling. (labroots.com)
  • While artificial membranes have been used to model the properties of native membranes, previous methods have not been able to mimic lipid membrane remodeling," explained Devaraj, an Associate Professor of Chemistry and Biochemistry at UC San Diego and the leader of the research team for this paper and previous work on the topic. (labroots.com)
  • The membranes we created, though completely synthetic, mimic several features of more complex living organisms, such as the ability to adapt their composition in response to environmental cues,' said Neal Devaraj, an assistant professor of chemistry and biochemistry at UC San Diego who headed the research team. (timesnownews.com)
  • The membrane present is constructed of structured layers of phospholipids to mimic the hydrophobic membrane. (sygnaturediscovery.com)
  • Artificial rupture of membranes (AROM), also known as an amniotomy, is performed by a midwife or obstetrician and was once thought to be an effective means to induce or accelerate labor. (wikipedia.org)
  • The different techniques for artificial rupture of membranes have not been extensively compared in the literature. (wikipedia.org)
  • In one study comparing amnihook versus amnicot for artificial rupture of membranes, use of an amnicot was associated with fewer neonatal scalp lacerations. (wikipedia.org)
  • After binding to specific carbohydrates on the erythrocyte surface, CEL-III forms ion-permeable pores by oligomerizing in the membrane, which leads to colloid osmotic rupture of the cells. (ebscohost.com)
  • Artificial rupture of the membranes , also known as breaking the waters or amniotomy , is common practice in many labour units around the world. (ausmed.co.uk)
  • What is Artificial Rupture of the Membranes (ARM)? (ausmed.co.uk)
  • Artificial rupture of the amniotic membranes (ARM) during early labour is one of the most commonly performed procedures in midwifery practice. (ausmed.co.uk)
  • Some evidence suggested that the combined use of amniotomy and intravenous oxytocin is more effective than amniotomy alone, yet early rupture of the membranes is also found to be associated with an increase in the rate of caesarean sections (Romm 2010). (ausmed.co.uk)
  • Even though there are some suggested benefits, there is growing evidence that early rupture of the membranes is also associated with significant risks and disadvantages. (ausmed.co.uk)
  • The results were unequivocal with two-thirds of women reporting an increase in the rate, strength and pain of contractions following rupture of the membranes. (ausmed.co.uk)
  • To explore the feasibility of constructing a proof-of-concept artificial intelligence algorithm to detect tympanic membrane perforations, for future application in under-resourced rural settings. (edu.au)
  • Perforation size was categorised as less than one-third (small), one-third to two-thirds (medium), or more than two-thirds (large) of the total tympanic membrane diameter. (edu.au)
  • Results A total of 233 tympanic membrane images were used (183 for training, 50 for testing). (edu.au)
  • Conclusion A proof-of-concept image-classification artificial intelligence algorithm can be used to detect tympanic membrane perforations and, with further development, may prove to be a valuable tool for ear disease screening. (edu.au)
  • Thermally-induced fluctuations of individual phospholipids in a bilayer lipid membrane (BLM) are converted into collective motions due to the intermolecular interactions. (ebscohost.com)
  • HCP caused an increase in the electrical conductivity of lipid bilayer membranes made from lecithin and other phospholipids. (oregonstate.edu)
  • The team at the University of California - San Diego said the achievement will allow scientists to more accurately replicate the behaviour of living cell membranes, which until now have been modelled only by synthetic cell membranes without the ability to add new phospholipids. (timesnownews.com)
  • In conclusion, we propose a new approach to determining the pharmacology of drugs for membrane targets that accounts for differences in local drug concentration brought about by direct affinity for phospholipids, establishing "micro-pharmacokinetic/pharmacodynamic relationships" for drugs. (aspetjournals.org)
  • What drove the transition from such membranes to modern ones, which are based on the more complex phospholipids? (newscientist.com)
  • Despite the fact that a large number of synthetic channels have been developed in the last three decades, few of them can function in mammalian cell membranes because of their weak membrane insertion abilities. (rsc.org)
  • The method employs the use of a fluorescent artificial receptor (FAR), composed of a macrocycle in combination with an encapsulated fluorescent dye, administered in the acceptor chamber of conventional PAMPA microplates. (frontiersin.org)
  • Parallel Artificial Permeability Assays (PAMPA) offer researchers a quick, inexpensive method of evaluating the permeability of test compounds. (bioassaysys.com)
  • The PAMPA artificial membrane has a lipid-oil-lipid tri-layer structure constructed in the pores of a porous filter. (creative-bioarray.com)
  • The oil layer in the middle, which maintains a robust and stable PAMPA membrane, is ultra-thin to minimize compound retention and interference with the compound permeation. (creative-bioarray.com)
  • Devaraj thinks their achievements will give biochemists a way to improve the understanding of the many changes that occur in cellular membranes during lipid remodeling. (labroots.com)
  • Also, filtration is a critical component of biopharmaceuticals production, and membrane microfiltration is widely used to remove cellular debris and other cellular colloids. (prnewswire.co.uk)
  • Interactions among Cellular Membranes. (pas.va)
  • Rapid purification of functional cytochrome P-450 and P-450 reductase by high pressure liquid chromatography utilizing immobilized artificial membranes (IAM): A new solid phase membrane mimetic matrix. (springer.com)
  • Layer-by-layer membrane assembly allows us to create synthetic cells with membranes of arbitrary complexity at the molecular and supramolecular scale," said TSRI Assistant Professor Brian Paegel, who authored the study with Research Associate Sandro Matosevic. (healthcanal.com)
  • We can now control the molecular composition of the inner and outer layers of a bilayer membrane, and even assemble multi-layered membranes that resemble the envelope of the cell nucleus. (healthcanal.com)
  • By modifying a single building block in Gal-8's structure, exactly as nature does in a portion of the population, the researchers dramatically impaired its ability to communicate with the artificial membrane, suggesting a possible molecular basis for the disease. (healthcanal.com)
  • Artificial cells made of molecular components and lipid membrane are emerging platforms to characterize living systems properties. (elsevier.com)
  • Synthetic cell membranes that can grow like real membranes will be an important new tool for synthetic biology and origin of life studies,' he said. (timesnownews.com)
  • Scientists led by an Indian-origin researcher have designed and synthesised an artificial cell membrane capable of sustaining continual growth, just like a living cell. (timesnownews.com)
  • Chemists and biologists at UC San Diego have succeeded in designing and synthesizing an artificial cell membrane capable of sustaining continual growth, just like a living cell. (phys.org)
  • The lateral mobility of individual murine polyoma virus-like particles (VLPs) bound to live cells and artificial lipid bilayers was studied by single fluorescent particle tracking using total internal reflection fluorescence microscopy. (pnas.org)
  • Here, trajectories of individual, fluorescence-labeled VLPs on the surface of tissue culture cells and in artificial lipid bilayers were recorded with total internal reflection fluorescence (TIRF) microscopy for SPT. (pnas.org)
  • A patient's own white cells could be harvested and used to create personalized LLVs By cloaking nanoparticles in the membranes of white blood cells, scientists at The Methodist Hospita. (innovationtoronto.com)
  • However, it is very difficult to study the membranes directly in live cells inside the human body. (kit.edu)
  • We present a method to artificially induce network formation of membrane glycoproteins and show the precise tuning of their interconnection on living cells. (uni-muenchen.de)
  • Cells use lipid remodeling to respond to their environment and maintain membrane homeostasis or to carry out specific functions such as division and signaling," said a graduate student in the Devaraj lab, Andrew Rudd, one author of the study. (labroots.com)
  • Currently desired manipulations of eukaryotic cells comprise the specific modification of their extracellular surface, in particular the cell membrane. (biomedcentral.com)
  • Research topics range from single molecule biophysics and evolution to synthetic biology and artificial cells. (jobbird.com)
  • In addition, the survival of Chediak-Higashi and beige-J fibroblasts after wounding was reduced, indicating that impaired lysosomal exocytosis inhibits membrane resealing in these mutant cells. (pnas.org)
  • Immunofluorescence with mAbs against rat (LY1C6, provided by I. Mellman, Yale University, New Haven, CT), human (H4A3), or mouse (Protein Data Bank ID code 1D4B) lysosomal-associated membrane protein 1 (Lamp1) (Developmental Studies Hybridoma Bank, University of Iowa, Iowa City) was performed as described for attached cells ( 13 ). (pnas.org)
  • By employing theoretical models and performing tests on cultured cells, the researchers found that it took less energy for a cell membrane to engulf disc-shaped particles than rod-shaped ones, which they had originally expected to be the most efficient. (fiercepharma.com)
  • This emphasizes the crucial role of the membrane for designing cell-free TXTL microreactors as efficient artificial cells. (elsevier.com)
  • Fortunately, there is much to be learned from tackling a more modest goal, that of building simple artificial cells, beginning with their walls. (newscientist.com)
  • If we can find it in artificial cells, we will be transported back to the onset of Darwinian evolution and the origins of life as we know it. (newscientist.com)
  • We are looking for Honours or PhD students who have an interest in DNA origami design, synthetic biology, and artificial cells to learn across the interface of engineering and biology. (edu.au)
  • In this study, we employed quantitative fluorescence microscopy techniques to investigate this phenomenon in both artificial and biological membrane bilayers in an acoustofluidic system. (nih.gov)
  • Membrane microfiltration helps remove unwanted particles from water before the water is treated for purity using other processes such as reverse osmosis. (prnewswire.co.uk)
  • The membrane coating is formed from cordierite particles which have been processed to have a median particle size diameter of between 1 and 3 microns with a narrow particle size distribution suitable for forming a cordierite membrane on a cordierite monolith substrate. (freepatentsonline.com)
  • The Aubin-Tam group is looking for a highly motivated PhD student to work on a completely novel experimental platform that interfaces free-standing lipid membranes with optical tweezers inside a microfluidic device. (jobbird.com)
  • Here, we introduce the combination of optical tweezers with free-standing lipid bilayers, which are fully accessible on both sides of the membrane. (tudelft.nl)
  • If the drug has diffused across the hydrophobic membrane, it will be detected in the acceptor compartment. (sygnaturediscovery.com)
  • This proteolipid has now been incorporated into ultrathin lipidic membranes, and the membrane resistance was studied. (rupress.org)
  • 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. (wakehealth.edu)
  • It is often given after the membranes are spontaneously or artificially ruptured. (kidspot.com.au)
  • Nylon-2, 8 capsules were synthesized and the micropores in their membranes were coated with lipid bilayer. (nii.ac.jp)
  • We are developing lipid-based artificial cell membranes as an experimental platform which accommodates membrane receptors for further pharmaceutical and diagnostic applications. (biomimeticsgroup.com)
  • Simulation of human skin permeation by immobilized artificial membrane HPLC columns. (springer.com)
  • The purpose of this study was to construct and examine the prediction model for total passive permeation through the intestinal membrane. (nih.gov)
  • Part of the reason cell membrane sugars, called glycans, are so poorly understood is that scientists were unable to accurately model them until last year, when Percec's lab devised a way of programming artificial membranes with a precise number and spatial arrangement of sugars. (healthcanal.com)
  • The scientists said that to develop the growing membrane they substituted a 'complex network of biochemical pathways used in nature with a single autocatalyst that simultaneously drives membrane growth. (timesnownews.com)
  • Scientists produce an artificial cell membrane but it is along way from producing an artificial cell. (blogspot.com)
  • Global Medical Membranes Market is accounted for $2.05 billion in 2017 and is expected to reach $5.28 billion by 2026 growing at a CAGR of 11.0% during the forecast period. (medgadget.com)
  • Successful artificial photosynthesis is significant for future human/robotic exploration and terrestrial carbon emissions control. (techbriefs.com)
  • The Artificial Photosynthesis Process and its similarity to natural photosynthesis. (techbriefs.com)
  • The reduction of carbon dioxide to organic chemicals in an electrochemical cell is a viable approach to achieving artificial photosynthesis. (techbriefs.com)
  • The electrochemical method of artificial photosynthesis is a promising approach for the conversion, separation and sequestration of carbon dioxide for confined environments as in space habitats, and also for carbon dioxide management in the terrestrial context. (techbriefs.com)
  • This year, the US Department of Energy earmarked $122 million to set up the Joint Center for Artificial Photosynthesis in California. (newscientist.com)
  • In the coarse, porous layer of the cellulose acetate membrane, diffusion occurs mainly through aqueous channels. (rupress.org)
  • Partitioning of a drug into the membrane compartment not only potentially depletes drug from the aqueous compartment but also concentrates drug in the local environment around the receptor, which may alter the observed pharmacology of a compound ( Sargent and Schwyzer, 1986 ), particularly if the drug is able to access the target receptor from this compartment. (aspetjournals.org)
  • Such studies aim to use constitutional artificial desalination membranes for highly selective water transport. (rsc.org)
  • Last year they were able to create synthetic membranes that were able to grow. (labroots.com)
  • Artificial neural membrane (ANM) refers to a new class of functional structure developed through research adaptive and evolutionary neural networks and programmable materials. (wikipedia.org)
  • Therefore, the main aim of this work was to optimize the temperature, dimethylsulfoxide (DMSO) concentration and the methanol flow-rate for the biosynthesis of recombinant MBCOMT by Pichia pastoris bioreactor methanol-induced cultures using artificial neural networks (ANN). (biomedcentral.com)
  • In order to achieve this goal, Artificial Neural Networks was applied. (environmental-expert.com)
  • These features are most often used for a variety of analyses including fuzzy logic, evolutionary calculations, neural networks, or artificial life. (biomedcentral.com)
  • The researchers at the University of Basel have now been able to measure this in a practical experiment for the first time, demonstrating that the thicker the membrane, the slower the movement of the channel protein is in comparison to the movement of the actual polymers that form the membrane. (nanowerk.com)
  • To demonstrate the utility of their new model, the researchers studied how mutant varieties of Gal-8 interacted with a custom artificial membrane containing Gal-8's specific binding sugars. (healthcanal.com)
  • Consequently, researchers frequently use model membranes that are applied to special surfaces. (kit.edu)
  • Researchers at the University of California San Diego have been hard at work developing artificial replicas of cell membranes. (labroots.com)
  • Researchers in Japan have engineered a membrane with advanced features capable of removing harmful greenhouse gases from the atmosphere. (ecnmag.com)
  • Easan Sivaniah - an associate professor at Kyoto University's Institute for Integrated Cell-Material Sciences (iCeMS) - led an international team of researchers from iCeMS and the University of Cambridge to create an advanced membrane capable of rapidly separating gases. (ecnmag.com)
  • Researchers at the U.K.'s University of Manchester and Germany's Karlsruhe Institute of Technology have developed a method by which they can create highly detailed cell membrane models on a graphene surface, providing a way to study how drugs behave when delivered across the lipid bilayer. (fiercepharma.com)
  • Like a pen on paper, the researchers say, the sharp tip allows for the creation of artificial membranes with nano-scale precision. (fiercepharma.com)
  • Every day all over the world, researchers work with artificial cell membranes. (phys.org)
  • In particular, it is shown how various artificial cell membranes can be spontaneously formed inside nanoholes. (chalmers.se)
  • While synthetic chemists have produced sophisticated architectures able to confine water clusters, most water channel based work is being conducted with natural protein channels as selectivity components, embedded in the diverse arrays of bio-assisted artificial systems. (rsc.org)
  • Most protein channels share some structural aspects, such as their self-assembled multiple subunits within trans-membrane domains and the selectivity of these protein channels is usually driven by the narrowest region of the pore, showing gating behaviours generated by the structural motion of the external subunits in response to voltage, ligand and pH stimuli. (rsc.org)
  • The advantages offered by the medical membranes are permeability and high selectivity. (medgadget.com)
  • There are lots of membrane sugar-protein interactions that are important for disease," Percec said. (healthcanal.com)
  • The interactions between the TAT peptide and the membrane are found to decrease the value of the membrane tension to 2.1 × 10-6 N/m. (tudelft.nl)
  • With the amnihook method, a sterile plastic hook is inserted into the vagina and used to puncture the membranes containing the amniotic fluid. (wikipedia.org)
  • With the membranes punctured, amniotic fluid is able to escape from the uterus and exit the vagina. (wikipedia.org)
  • The membranes are punctured with a crochet-like long-handled hook during a vaginal examination, releasing the amniotic fluid. (ausmed.co.uk)
  • While this assumption applies well to soluble enzymes, it is less satisfactory for membrane-associated targets (e.g. (aspetjournals.org)
  • This chapter discusses results of studies of the effects of pressure on the structure and phase behavior of lyotropic lipid mesophases, natural and model biomembrane systems as well as pressure effects on the interaction of peptides and drugs with membranes. (taylorfrancis.com)
  • Non-covalent immobilized artificial membrane reverse-phase high performance liquid chromatography was previously evaluated as a means whereby elution times for antimicrobial peptides from columns mimicking the lipid bilayers of different membrane systems might be used as a fast-screening method to compare relative binding effectiveness. (ualberta.ca)
  • Such a system would aid in the development of antimicrobial peptides that bind preferentially to model pathogenic systems and leave the host's membranes reasonably unaffected. (ualberta.ca)
  • A non-covalent approach allows for flexibility in membrane composition but was found to be inadequate for analysis of most peptides due to significant lipid loss at high acetonitrile concentrations. (ualberta.ca)
  • These columns had lipid packing densities much lower than true membranes, indicating that the peptides were partitioning deep into the bonded phase of the columns rather than into the interfacial region of the phosphate head groups, as expected in situations of biologically-relevant lipid packing densities. (ualberta.ca)
  • For artificial enzyme membranes, due to the well-defined context it is possible to write in a simple way equations ruling the systems and to compare calculated and experimental results. (springer.com)
  • Tools for the identification of trans-membrane spans from the protein sequence are widely used in the experimental community. (sciweavers.org)
  • From the experimental values of ω and K 8 , the over-all friction, f , experienced by the solutes in the membrane was computed. (rupress.org)
  • Experimental results have demonstrated that natural biomolecules can be used as bio-assisted building blocks for the construction of highly selective water transport through artificial channels. (rsc.org)
  • 5. The ornamental article as defined in claim 1, wherein said coating membrane is dyed or colored. (google.com)
  • 7. The ornamental article as defined in claim 1, wherein said coating membrane is a cured film containing a finely particulate inorganic oxide. (google.com)
  • 6. The membrane of claim 1 wherein the coupler comprises the carbonyl groups, sulfonyl groups, or combination thereof bonded together through an organic radical wherein the organic radical is a C 2-20 saturated or unsaturated aliphatic, aromatic, or aliphatic-aromatic group that is substituted or unsubstituted with halogen or C 1-4 alkyl, alkoxy, or carboxy and has 0-5 heteroatoms wherein the heteroatom is oxygen, sulfur, or nitrogen. (google.com)
  • 2. The cordierite membrane monolith of claim 1 wherein the cordierite membrane comprises a median pore size of 0.1 to 1 μm. (freepatentsonline.com)
  • 4. The cordierite membrane monolith of claim 1 wherein the cordierite membrane comprises a single layer of cordierite membrane. (freepatentsonline.com)
  • 5. The cordierite membrane monolith of claim 1 wherein the cordierite membrane comprises more than one layer of cordierite membrane. (freepatentsonline.com)
  • 14. The cordierite membrane monolith of claim 1 wherein the cordierite monolith substrate comprises a surface roughness measured by rms roughness of 1.5 to 6 μm. (freepatentsonline.com)
  • 15. The cordierite membrane monolith of claim 1 wherein the cordierite membrane monolith comprises a Peak to Valley surface roughness of from 10 to 20 μm. (freepatentsonline.com)
  • 16. The cordierite membrane monolith of claim 1 wherein the cordierite membrane monolith comprises an rms surface roughness of from 0.5 to 2 μm. (freepatentsonline.com)
  • 17. The cordierite membrane monolith of claim 1 wherein the cordierite membrane monolith comprises a roughness average (Ra) surface roughness of from 0.5 to 1.5 μm. (freepatentsonline.com)
  • In this way, artificial enzyme membranes or at least artificial immobilization of the enzymes could be a mean to study this kind of phenomena, because enzyme kinetics are frequently non-linear or autocatalytic and the systems are ruled by diffusion-reaction coupling, that is to say by partial differential equations. (springer.com)
  • The diffusion of two series of alcohols and amides through complex cellulose acetate membranes was studied. (rupress.org)
  • Properties of an Artificial Membrane: Diffusion and Osmosis Purpose- Is to gather enough evidence to prove that osmosis and diffusion occur in these types of membranes, this is done by using a selectively permeable membrane called dialysis tubing. (markedbyteachers.com)
  • Solute size and concentration gradient across the selectively permeable membrane will effect diffusion. (markedbyteachers.com)
  • Materials- please refer to transport across semi-permeable membranes: diffusion and osmosis laboratory exercise hand out. (markedbyteachers.com)
  • The Mathematical Theory of Diffusion and Reaction in Enzymes Immoblized Artificial Membrane. (deepdyve.com)
  • Passive diffusion is an important factor in determining the absorption of orally administered compounds in the gastrointestinal tract (GIT), penetration of the blood-brain barrier (BBB), and general transport across cell membranes. (creative-bioarray.com)
  • Although there is much to suggest that biological membranes have a lipoprotein character, their actual composition and structure has not been established beyond question. (springer.com)
  • An ornamental article comprising a natural ornamental material such as pearl and a cured coating membrane of a composition based on organic materials which is coated on the surface of said natural ornamental material in a thickness from 0.01 μm to 30 μm, with improved properties such as surface luster. (google.com)
  • Is the Subject Area "Membrane composition" applicable to this article? (plos.org)
  • Artificial membranes for membrane protein purification, functionality and structure studies. (leedsbeckett.ac.uk)
  • The cell membrane is one of the most important components of a cell because it separates the interior from the environment and controls the movement of substances in and out of the cell. (slashdot.org)
  • Other applications include biotechnology processes, morphing aircraft and spacecraft, adaptive wind generators, and artificial organs. (wikipedia.org)
  • THOMAS, D. and CAPLAN, S.R., in "Membrane Separation Processes", Ed. Meares P. Elsevier Publishing Co. Amsterdam (1974). (springer.com)
  • This makes the sensor compatible with studies of processes related to biological membranes. (chalmers.se)
  • Membrane microfiltration is also increasingly used in biodiesel processes where this technology is used to reuse water especially in areas of water scarcity. (prnewswire.co.uk)
  • The need to functionalize cell membranes in a directed way for specific applications as single cell arrays or to force close cell-to-cell contact for artificial intercellular interaction and/or induction concerning stem cell manipulation or in general to have a tool for membrane and cell surface-associated processes, we envisaged a neutral inactive membrane anchor for extracellular entities to facillitate the above mentioned functionalities. (biomedcentral.com)
  • Cell lipid membranes are the site of vital biological processes, such as motility, trafficking and sensing, many of which involve mechanical forces. (jobbird.com)
  • A large number of these processes depend on unequal conditions on each side of the membrane, e.g., protonmotive force. (jobbird.com)
  • To understand how such diverse and vital processes are influenced by mechanical forces, it is essential to use force measurement tools that can track the dynamic response of membrane processes. (jobbird.com)
  • For a rather less hit-and-miss strategy, we can use computer-led "rational design" modelling processes to make artificial enzymes from scratch. (newscientist.com)
  • Membranes, Artificial" is a descriptor in the National Library of Medicine's controlled vocabulary thesaurus, MeSH (Medical Subject Headings) . (wakehealth.edu)
  • Currently Aerospace Research Systems, Inc - the agency that pioneered work in developing artificial neurons for use in control of multifunctional smart structures - is applying the technology to reusable launch vehicles. (wikipedia.org)
  • Understanding the myriad biochemical roles of membranes requires the ability to prepare synthetic versions of these complex multi-layered structures, which has been a long-standing challenge. (healthcanal.com)
  • The resulting biomimetic membranes, i.e. membranes simulating biological structures, allow for the specific investigation of functions of cell membranes and the development of novel applications in medicine and biotechnology, such as biosensors. (kit.edu)
  • The synthesis of SNAP-tag-DARC, its correct incorporation into the cell membrane and the functionality of the SNAP-tag® were verified by RT-PCR, Western blotting and confocal fluorescence microscopy and showed the desired functionality as an membrane anchor for an extracellular application entity. (biomedcentral.com)
  • There was also an apparent expansion of the inner membrane. (oregonstate.edu)
  • A study of rat liver mitochondrial permeability to protons was analyzed by the compartmental method and showed the presence of a mitochondrial compartment, representing mitochondria bounded by the inner membrane, and an extramitochondrial compartment. (oregonstate.edu)
  • HCP increased the permeability of the inner membrane to protons, and pH and temperature studies showed that the mechanism involves the transference of the HCP monoanion across the membrane. (oregonstate.edu)
  • We introduce a predictor that is able to identify trans-membrane spans from the sequence of a protein. (sciweavers.org)
  • The novelty of the approach presented here is the simultaneous prediction of trans-membrane spanning -helices and -strands within a single tool. (sciweavers.org)
  • The donor plate membrane is a Hydrophobic PVDF membrane with a pore size of 0.45 µm. (bioassaysys.com)
  • After the cordierite membrane is formed on the cordierite monolith substrate, the cordierite membrane monolith has a pore size of less than 1 micron. (freepatentsonline.com)
  • wherein the cordierite membrane monolith has a median pore size of less than 1 μm. (freepatentsonline.com)
  • The buffering capacity and membrane permeability of the compartments was measured. (oregonstate.edu)
  • Recent studies revealed that conventional lysosomes behave as Ca 2+ -regulated secretory compartments and play a central role in membrane resealing. (pnas.org)
  • According to Future Market Insights forecasts, sales revenue in the membrane microfiltration market is anticipated to cross US$ 8 Bn by 2028, from an estimated value of about US$ 3.8 Bn in 2018. (prnewswire.co.uk)