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
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 - 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).
Uridine triacetate - Get up-to-date information on Uridine triacetate side effects, uses, dosage, overdose, pregnancy, alcohol and more. Learn more about Uridine triacetate
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 ...
... (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 ...
... (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 ...
"Parallel Artificial Membrane Permeability Assay: A New Membrane for the Fast Prediction of Passive Human Skin Permeability". ... Although active transport is not modeled by the artificial PAMPA membrane, up to 95% of known drugs are absorbed by passive ... 2008) A Novel Design of Artificial Membrane for Improving the PAMPA Model. Pharmaceutical Research, 25: 1511. Avdeef, Alex ( ... In medicinal chemistry, parallel artificial membrane permeability assay (PAMPA) is a method which determines the permeability ...
AROM: artificial rupture of membranes. This term describes a rupture of the membranes by a third party, usually a midwife or ... PROM: premature rupture of membranes. This term describes a rupture of the membranes that occurs before the onset of labor. ... SROM: spontaneous rupture of membranes. This term describes the normal, spontaneous rupture of the membranes at full term. The ... PPROM: preterm, premature rupture of membranes. This term describes a rupture of the membranes that occurs before 37 weeks ...
Staff (January 26, 2012). "Chemists create artificial cell membrane". Archived from the original on January 28 ... The membrane also contains membrane proteins, including integral proteins that span the membrane and serve as membrane ... plasmatic membrane (Pfeffer, 1900), plasma membrane, cytoplasmic membrane, cell envelope and cell membrane. Some authors who ... The cell membrane (also known as the plasma membrane (PM) or cytoplasmic membrane, and historically referred to as the ...
Hollow fiber membranes (HFMs) are a class of artificial membranes containing a semi-permeable barrier in the form of a hollow ... The properties of the membrane -such as average pore diameter and membrane thickness- can be finely tuned by changing the ... Domestic water filtration systems have microfiltration hollow fiber membranes. In microfiltration a membrane pore diameter of ... Ultrafiltration membranes are capable of removing not only bacteria, but also viruses. Hollow fibers are commonly used ...
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. Archived from the original on 2013-10-04. ... 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". Archived from the original on January 28 ... 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 ...
The device used is a membrane oxygenator, also known as an artificial lung. ECMO works by temporarily drawing blood from the ... Extracorporeal membrane oxygenation (ECMO), also known as extracorporeal life support (ECLS), is an extracorporeal technique of ... ECMO is also used to support patients with the acute viral pneumonia associated with COVID-19 in cases where artificial ... body to allow artificial oxygenation of the red blood cells and removal of carbon dioxide. Generally, it is used either post- ...
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 ...
February 2009). "Interaction of an artificial antimicrobial peptide with lipid membranes". Biochimica et Biophysica Acta (BBA ... 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 ... antimicrobial peptides will show different affinities towards the bacterial membranes and mammalian cell membranes. In addition ...
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- ...
His research interests include artificial cells, lipid membranes, and bioconjugation. Devaraj attended college at the ...
"Artificial surfactant therapy in hyaline-membrane disease". The Lancet. 315 (8159): 55-59. doi:10.1016/s0140-6736(80)90489-4. ...
See this document for definitions of penetrant (permeant), synthetic (artificial) membrane, and anion-exchange membrane. ... Other types of semipermeable membranes are cation-exchange membranes (CEMs), anion-exchange membranes (AEMs), alkali anion ... Semipermeable membrane is a type of biological or synthetic, polymeric membrane that will allow certain molecules or ions to ... An example of a biological semi-permeable membrane is the lipid bilayer, on which is based the plasma membrane that surrounds ...
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". ...
"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, ...
The mucous membranes are dark. The lyre-shaped horns are brought up. The breed is of small size and low weight. Cows measures ... 227 In 2001 there were 28,000 cows and 1,300 bulls for natural and 6 for artificial insemination. The numbers are stable and 60 ...
Artificial Neural Networks, ANN ). An artificial neural network is a network of artificial neurons. An artificial neuron A is ... A generic membrane system (P-system) consists of cell-like compartments (regions) delimited by membranes, that are placed in a ... Artificial Immune Systems and Their Applications. Springer, 1998 de Castro, L., Timmis, J. Artificial Immune Systems: A New ... Some lipids can self-assemble into biological membranes. A lipid membrane consists of a lipid bilayer in which proteins and ...
It can transfer up to 7 sterol molecules per minute between artificial membranes. STARD4 may regulate cholesterol levels in ...
... on artificial and native membranes". Cell Biochemistry and Function. 20 (1): 31-7. doi:10.1002/cbf.932. PMID 11835268. ...
Membranes for artificial cells can be made of simple polymers, crosslinked proteins, lipid membranes or polymer-lipid complexes ... The membranes of artificial cells are much thinner those used in dialysis and their small size means that they have a high ... Although not completely artificial because the cytoplasmic components as well as the membrane from the host cell are kept, the ... Artificial cells allow toxins to diffuse into the cell while keeping the dangerous cargo within their ultrathin membrane. ...
... 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 ...
"Development of Extrauterine Fetal Incubation System Using Extracorporeal Membrane Oxygenator". Artificial Organs. 11 (3): 224- ... An artificial womb or artificial uterus is a device that would allow for extracorporeal pregnancy by growing a fetus outside ... An artificial uterus may include components of equivalent function. Methods have been considered to connect an artificial ... The scope of an artificial uterus (or "artificial uterus system" to emphasize a broader scope) may also include the interface ...
Di, Li; Kerns, Edward H; Fan, Kristi; McConnell, Oliver J; Carter, Guy T (7 March 2003). "High throughput artificial membrane ...
Its flight membranes are dark in color. It is nocturnal, roosting in sheltered places during the day. As of 2010, all known ... It is possible that its population has increased with urbanization due to the abundance of artificial roosting sites. Natural ... Its ears are united by a connecting process referred to as the interaural membrane. It can be distinguished from the similar ...
Carbon Dioxide Removal from e.g. Blood using Membrane and Immobilized Carbonic Anhydrase; Artificial Lung for Example, US ... "Engineering of cell membranes with a bisphosphonate-containing polymer using ATRP synthesis for bone targeting". Biomaterials. ... "Membrane/Mediator-Free Rechargeable Enzymatic Biofuel Cell Utilizing Graphene/Single-Wall Carbon Nanotube Cogel Electrodes". ...
She has identified the speed at which viral genomes are transferred out of viruses and into the cell membranes. Cell membranes ... She showed that an artificial glycocalyx-like nanostructure could serve as a size-selective filter for protein binding. This ... with a focus on how viruses interact with cell membranes. Her motivation to study virus - membrane interactions lies in the ... Daniel used membrane fusion to identify a specific targets for anti-viral drugs. To continue her studies of coronaviruses, she ...
Gao C, Mao S, Lo CH, Wirsching P, Lerner RA, Janda KD (May 1999). "Making artificial antibodies: a format for phage display of ... Ff phages for phage display is that they require the protein of interest to be translocated across the bacterial inner membrane ... An example is Weiss and Sidhu's inverted artificial coat protein (ACP) which allows the display of large proteins at the C- ... Weiss GA, Sidhu SS (June 2000). "Design and evolution of artificial M13 coat proteins". J. Mol. Biol. 300 (1): 213-9. doi: ...
When the expansion caused the membrane to burst, a new membrane was quickly formed. In this way, the cell could "grow" and ... The artificial cell would expand and bud like living cells. Surgeon and professor Wilhelm Pfeffer used this model to study and ... The membrane is semi-permeable, and expands rapidly into the Traube cell. Within the cell is a high concentration of potassium ... The Traube cell is not a true artificial cell, as it is not living and does not have true biological processes of its own. ...
... dust and salts are very irritating to the eyes and mucous membranes, and moderately irritating to skin. Breathing the ... the most stable artificial isotope is 147Nd with a half-life of 10.98 days. Neodymium also has 13 known metastable isotopes, ...
ISBN 978-1-78064-442-4. Juan C. Samper (1 January 2009). Equine Breeding Management and Artificial Insemination. Elsevier ... which is thought to equalize air pressure on the tympanic membrane. Located between the mandibles but below the occiput, it ...
One application is the creation of artificial derivatives from S. acidocaldarius proteins, named affitins. Intracellular ... as Sulfolobus species maintain a significant pH gradient across the outer membrane. Sulfolobales are metabolically dependent on ...
"Artificial Testicle Could Make Sperm for Infertile Men". 2012-01-27. Retrieved 11 May 2012. Lorie A., Parch (2012-01-27). " ... The Hypoosmotic Swelling Test is a laboratory test to measure the functional integrity of the human sperm membrane. In this ... "Artificial testicle could help infertile men". Archived from the original on 12 February 2012. Retrieved 11 May 2012. "Doctors ...
"Membrane inspired by bone and cartilage efficiently produces electricity from saltwater". ScienceDaily. Retrieved 2021-02-10. " ... "Mass production of bulk artificial nacre with excellent mechanical properties". Nature Communications. 8 (1): 287. doi:10.1038/ ... and cartilage-like membranes with both high strength and ion conductance. Kotov's research is focused on the development of ... and membrane properties. Kotov extended the concept of biomimetic nanostructures to inorganic nanoparticles. He established ...
Within the basilar membrane, energy is transferred, and specific frequencies can be detected and activate auditory hairs. The ... To measure the initiation of speech, an artificial palate was placed in the speaker's mouth. When the tongue moved to begin ... Alveolar consonants were measured when the tongue first touched an artificial palate and labial consonants were measured by the ...
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 ...
In those with facial palsy, frequent use of artificial tears while awake is recommended, along with ointment and a patch or ... Spirochetes are surrounded by peptidoglycan and flagella, along with an outer membrane similar to Gram-negative bacteria. ... Because of their double-membrane envelope, Borrelia bacteria are often mistakenly described as Gram negative despite the ...
The Georgia Dome originally used AstroTurf artificial surface for its football events. In 2003, Arthur Blank, the new owner of ... Tensile membrane structures, Venues of the 1996 Summer Olympics, Handball venues in the United States, Olympic basketball ... the Dome's artificial turf had been removed and its offices vacated prior to the announcement of the new stadium's delay. On ... Atlanta Falcons, funded the installation of the new infilled FieldTurf artificial surface system. In 2006, the Atlanta Falcons ...
The PPII helix is not common in transmembrane proteins, and this secondary structure does not traverse lipid membranes in ... Germany constructed and experimentally observed the first transmembrane PPII helix formed by specifically designed artificial ... "Bilayer thickness determines the alignment of model polyproline helices in lipid membranes". Physical Chemistry Chemical ...
Products included artificial joints, components for medical machines and implantable screws, rods and plates. The 88,000-ft2 ... "CoorsTek Creates CoorsTek Membrane Sciences," Ceramic Industry, 23 Jun 2015. D. Clark, et al., "Single-step hydrogen production ... A new subsidiary, CoorsTek Membrane Sciences AS, was launched in Oslo, Norway, in 2015 to commercialize BASE, SOFC and other ... The battery uses a beta-alumina solid electrolyte (BASE) ceramic membrane to separate the sulfur anode and sodium cathode. ...
C. R. Safinya, et al., « Steric interactions in a model membrane system: a synchrotron x-ray study », Phys. Rev. Lett., 57, ( ... internalization of artificial "viruses"). Subsequently, and led initially by chance to a discovery, he systematically worked ... surfaces by highlighting in particular the existence of undulation interactions between membranes and the discovery of membrane ...
The lipid container permits transfection past a cell membrane, whilst the protein capsule can bind chemotherapeutic molecules. ... "Computationally Designed Stable Artificial Phosphotriesterases for Detoxification of Organophosphorus Agents". {{cite journal ...
... a probabilistic model that is widely used in artificial intelligence Mask data preparation, a process in electronic design ... automation Media Dispatch Protocol, a file transfer protocol Membrane dipeptidase, an enzyme Mini DisplayPort, a digital ...
Bonitz SG, Coruzzi G, Thalenfeld BE, Tzagoloff A, Macino G (December 1980). "Assembly of the mitochondrial membrane system. ... and structure of a highly specific artificial endonuclease". Mol. Cell. 10 (4): 895-905. doi:10.1016/S1097-2765(02)00690-1. ... translocating adenosine triphosphatase from vacuolar membranes of Saccharomyces cerevisiae". J Biol Chem. 265 (12): 6726-33. ...
... class of materials is also used in the production of disposable medical devices as well as fabrication of artificial membranes ... Production of rayon ("artificial silk") from cellulose began in the 1890s and cellophane was invented in 1912. Hermann ... Each RTC floats in the cell's plasma membrane and "spins" a microfibril into the cell wall. RTCs contain at least three ... In plants cellulose is synthesized at the plasma membrane by rosette terminal complexes (RTCs). The RTCs are hexameric protein ...
Artificial gene delivery can be mediated by physical methods which uses force to introduce genetic material through the cell ... Cells are briefly shocked with an electric field of 10-20 kV/cm, which is thought to create holes in the cell membrane through ... Most cells require some sort of intervention to make the cell membrane permeable to DNA and allow the DNA to be stably inserted ... The heat-pulse is thought to create a thermal imbalance across the cell membrane, which forces the DNA to enter the cells ...
The invagination of the plasma membrane of ascus generates the two unit membranes that consist of the ascus vesicle. Then ... Ascodesmis nigricans is easily to grow on artificial media within a proper temperature range, which is around 24 °C. Also, ... The inner delimiting membrane became the primary wall with a consistent structure and no ornamentation. The ascospores would ... As soon as the primary wall is formed, the wall material deposited in the original space between two delimiting membranes gives ...
According to research performed by Maddalena et al., using artificial neural networks, position 7 has the most effect on ... at neuronal membranes could not only potentiate the L-838,417-induced analgesia but also rescue its analgesic potential at high ... "Prediction of receptor properties and binding affinity of ligands to benzodiazepine/GABAA receptors using artificial neural ...
1992). "A Platform for Evolving Genetic Automata for Text Segmentation (GNATS)". Science of Artificial Neural Networks. 1710: ... hard problem of consciousness involves determining how physiological processes such as ions flowing across the nerve membrane ...
Prostate-specific membrane antigen (PSMA) stimulates cancer development by increasing folate levels, helping the cancer cells ... More invasive surgical treatment can include the insertion of a urethral sling or an artificial urinary sphincter, which is a ... Yao V, Berkman CE, Choi JK, O'Keefe DS, Bacich DJ (February 2010). "Expression of prostate-specific membrane antigen (PSMA), ... April 2020). "Prostate-specific membrane antigen PET-CT in patients with high-risk prostate cancer before curative-intent ...
Director of the Australian Artificial Intelligence Institute Rick Jelliffe - inventor of the Schematron schema language Rod ... the ionic mechanisms involved in excitation and inhibition in the peripheral and central portions of the nerve cell membrane" ...
The neurotransmitter binds to receptor molecules in the membrane of the target cell. Synapses are the key functional elements ... artificial intelligence and similar fields) and philosophy. The oldest method of studying the brain is anatomical, and until ... Vertebrate brains are surrounded by a system of connective tissue membranes called meninges that separate the skull from the ... Neurotransmitters are chemicals that are released at synapses when the local membrane is depolarised and Ca2+ enters into the ...
Nanowires are artificial nano- or micro-sized "needles" that can provide high-fidelity electrophysiological recordings if used ... The blood brain barrier functions as a highly specialized semipermeable membrane surrounding the brain, preventing harmful ...
In the 1960s and 1970s Merrill was a pioneer in the development of the artificial kidney, analysis of its transport ... Colton, C. K.; Smith, K. A.; Merrill, E. W.; Farrell, P. C. (1971). "Permeability studies with cellulosic membranes". Journal ... Merrill's work on highly crosslinked polyethylene (1990s with W Harris) led to the new HDPE materials used in artificial joints ... led to the development of the first NIH guidelines for artificial kidneys in the 1960s. Ed Merrill's scientific contributions ...
PV2s are able to disrupt intestinal cells altering the plasma membrane conductance and to form large pores in artificial lipid ... As a lectin, PV2s can agglutinate rabbit red blood cells and bind to the plasma membrane of intestinal cells both in vitro and ... In PV2 toxins, the lectin would bind to target membranes through the recognition of specific glycans, acting as a delivery "B" ... disulfide-linked to a pore-forming protein of the Membrane Attack Complex and Perforin (MACPF) family (toxic unit). Like most ...
The DOM2500 is a membrane sail 2.5 m × 2.5 m (8 ft 2 in × 8 ft 2 in) large when deployed, and will be used by ALE-1 to lower ... is a microsatellite for demonstrating the creation of artificial shooting stars. Built and operated by ALE Co., Ltd., it is the ... where it would deploy a 1-m2 membrane. The satellite decayed from orbit on 30 April 2022. Aoba VELOX-IV is a 2U CubeSat ... was developed by Tokyo Institute of Technology The Thin Membrane Solar Array Paddle (TMSAP) was developed by JAXA Fireant ( ...
... By Eric Sauter. The membranes surrounding and inside cells ... Scientists Develop New Process to Create Artificial Cell Membranes Researchers Shed Light on Bodys Master Energy Regulator ... "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- ...
... researchers have developed membranes with asymmetric artificial channels in the interior, from which they were able to observe ... Artificial bio-inspired membranes for water filtration. (Nanowerk News) From a desire to develop breakthrough technologies for ... Identifying the chiral water in the artificial channels in these lipid membranes, under physiological conditions similar to ... have developed membranes with artificial channels inspired by the proteins that form the pores in biological membranes: ...
Reconstituting Membrane Proteins Into Artificial Membranes and Detection of Their Activities Hyeseung Lee, Hyeseung Lee ... Lee, H, Ho, D, Chu, B, Kuo, K, & Montemagno, C. "Reconstituting Membrane Proteins Into Artificial Membranes and Detection of ... Triblock copolymer membrane was the alternative choice for membrane protein reconstitution since polymers are more durable, ... Identification of Membrane Protein Interactions with an Ensemble Classifier International Conference on Advanced Computer ...
Semi-artificial Photosynthetic CO2 Reduction through Purple Membrane Re-engineering with Semiconductor. In: Journal of the ... Semi-artificial Photosynthetic CO2 Reduction through Purple Membrane Re-engineering with Semiconductor. Journal of the American ... Semi-artificial Photosynthetic CO2 Reduction through Purple Membrane Re-engineering with Semiconductor. / Chen, Zhaowei; Zhang ... Semi-artificial Photosynthetic CO2 Reduction through Purple Membrane Re-engineering with Semiconductor. ...
effects on artificial biological membranes (phospholipids): real-time measurement of the superficial pressure (Wilhelmy ... Interactions between 60-GHz millimeter waves and artificial biological membranes: dependence on radiation parameters med./bio. ... Microdomains reflect functional specialization of the different membrane regions and play an important role in membrane ... of 60 GHz millimeter waves on the physical properties of phospholipid layers in artificial models of biological membranes. ...
... our DNA nanostructure spontaneously inserts into biological membranes by forming a toroidal pore that connects the membranes ... Furthermore, we show that our DNA-based enzyme can control the composition of human cell membranes, which opens new avenues for ... The membrane insertion catalyzes spontaneous transport of lipid molecules between the bilayer leaflets, rapidly equilibrating ... applications of membrane-interacting DNA systems in medicine. Mimicking enzyme function and improving upon it is a challenge ...
We model structures of two-dimensional heterogenic membranes, which resemble real membrane structures, and then we simulate a ... We test the effect of two parameters: the distribution of obstacles (filling) in the membrane and the value of drift on the ... Moreover, there exists the optimal value of drift, for which the transport through a membrane speeds up and does not cause ... It appears that the synergy between drift, the diffusion, and the membrane structure affect the occurrence of the ...
15 nm thick membranes). Membranes made from graphene have ultra-fast water transport and precise molecular sieving properties. ... thin films of multi-layered GO on a support membrane by an industrially adaptable method to produce large-area membranes (13 × ... Here, the authors show how large-area membranes can be manufactured by a rapid and scalable process based on shear alignment of ... The highly ordered graphene sheets in the plane of the membrane make organized channels and enhance the permeability (71±5 l m− ...
... artificial insemination; occupational exposure to HIV; or acupuncture, tattoos, body piercing, or other percutaneous injections ... Transmission of HIV Possibly Associated with Exposure of Mucous Membrane to Contaminated Blood In February 1996, transmission ... infected through mucous membrane exposure to the mans saliva that was contaminated by blood from his bleeding gums or exudate ... which suggests that the woman was infected through mucous membrane exposure to contaminated blood. * ...
Fabrication of Core-Shell Nanotube Array for Artificial Photosynthesis Featuring an Ultrathin Composite Separation Membrane ... Structure and Orientation of Molecular Wires Embedded in Ultrathin Silica Membrane for Artificial Photosynthesis Elucidated by ... Heterobinuclear Light Absorber Coupled to Molecular Wire for Charge Transport across Ultrathin Silica Membrane for Artificial ... Structure and Orientation of Molecular Wires Embedded in Ultrathin Silica Membrane for Artificial Photosynthesis Elucidated by ...
such as: a membrane stretch and sweep a pessary or gel artificial rupture of membranes (ARM)… Read More ... Category: Articles, Induction, Information, Interventions, Labour Tags: artificial rupture of membranes, breaking your waters, ...
The project developed an oxidation process for removing organics in membrane concentrates. ... Artificial Intelligence and Cyber Security. *Cybersecurity Barriers to Innovation: Addressing Risk and Innovation for Reuse ( ... RO membrane processes effectively remove organic, inorganic, and biological constituents, which accumulate in membrane ... Home\Educate\Water Reuse 101\Research Projects\Year\2010\Oxidative Treatment of Organics in Membrane Concentrates. Oxidative ...
It can be filtered before last decade and are done with pampa log pe calculations when a parallel artificial membrane ... Acute toxicity of parallel artificial membrane into solving all of parallel artificial membrane permeability assay protocol for ... The membrane permeability assay. You may not reach their function of parallel artificial membrane permeability assay protocol. ... Alternative methods are present which plays an artificial membrane for. Late Payment Deductible. Santa Poway In House Claus ...
Don t miss out on business opportunities in Artificial Intelligence (Chipsets) Market. Speak to our analyst and gain crucial ... HOME › Press Releases › Artificial Intelligence (Chipsets) Market worth $57.8 billion by 2026 ... According to the latest market research report "Artificial Intelligence (Chipsets) Market by Technology (Machine learning, ... What are the Known and Unknown Adjacencies Impacting the Artificial Intelligence (Chipsets) Market ...
Artificial rupture of membranes to assist delivery. 600. 1.6. 2.0. Source: AHRQ, Center for Delivery, Organization, and Markets ... and artificial rupture of membranes to assist in delivery. In 2009, there were about 250 bariatric procedures4 performed during ...
... of interest can be isolated or if the channels can be purified because they can then be incorporated into artificial membranes ... This includes the lipid composition of the membrane and the ionic solutions on both sides of the channel, thus allowing the ... Disruption of the cell is always necessary and hence experiments inevitably have a certain artificial nature about them. This ... membranes but in this chapter we describe how the techniques are also suited for ion channels of the acidic lysosomal and ...
Parchment Impregnated Ba(II) Molybdate Membrane, Membrane Potential, Bi-ionic Potential, Membrane Conductance, Membrane ... Studies on ion selectivity of parchment impregnated Ba(II) molybdate artificial membrane Authors. * Afren Ansari S.M.S. Govt. ... Effect of pore location and pore size of the support membrane on the permeance of composite membranes, J. of membrane science, ... The artificial membrane was tested for its antimicrobial activity against Gram-negative (Escherichia coli and Pseudomonas ...
HALO Tool - Artificial Rupture of Membranes [Poster]. Farry, A; Mellor C. Artificial rupture of membranes (ARM) can be a ... A study in 2018 at Waitemata DHB explored what shapes midwives decision-making around artificial rupture of membranes in low- ... Intact membranes have an important physiological function during labour and birth yet ARM is common, often performed without a ...
... buy HDPE with artificial sand waterproof pre-applied membrane for subway from China manufacturer. ... HDPE with artificial sand waterproof pre-applied membrane for subway. HDPE with artificial sand waterproof pre-applied membrane ... 1.The membrane can be fully bond to poured concrete.. 2.The membrane can be fully bond to poured concrete.. Features:. 1)Good ... Pre-applied Waterproofing Membrane MILE is composed of HDPE sheet, one special pressure sensitive adhesive, and artificial ...
... on a model of fluid membrane bilayers, the immobilized artificial membrane (IAM) column. The logarithms of chromatographic ... on a model of fluid membrane bilayers, the immobilized artificial membrane (IAM) column. The logarithms of chromatographic ... Chromatographic indexes on immobilized artificial membranes for the prediction of transdermal transport of drugs.. BARBATO, ...
... a membrane-integral AAA ATPase at mitochondria and peroxisomes, selectively recognizes uncomplexed substrate molecules in vivo ... Organelle-restricted Pex15 clearance by Msp1 with artificial transmembrane anchors. A recent study showed that GFP fused to the ... TA proteins native to the outer mitochondrial and peroxisomal membranes are directly inserted into these membranes by ... 2004) PEX3 functions as a PEX19 docking factor in the import of class I peroxisomal membrane proteins The Journal of Cell ...
Three-dimensional membranes for artificial lungs : Comparison of flow-induced hemolysis. Hesselmann, Felix (Corresponding ... Sie sind hier:Three-dimensional membranes for artificial lungs : Comparison of flow-induced hemolysis ... Sie sind hier: Three-dimensional membranes for artificial lungs : Comparison of flow-induced hemolysis ... In: Artificial organs. Band: 46. Heft: 3. Seite(n)/Artikel-Nr.: 412-426 ...
Artificial rupture of membranes§. 12 (63). 10 (44). 2.23 (0.54-9.41). 0.20. ...
... aims at predicting the passive membrane properties of drugs. Since 1998, model membranes have been developed to predict gastro‐ ... A relationship between the membrane concentration of certramides (from 0 to 100%) and the permeability of compounds was found, ... Parallel artificial membrane permeability assay: a new membrane for the fast prediction of passive human skin permeability.. *G ... The Parallel Artificial Membrane Permeability Assay (PAMPA) aims at predicting the passive membrane properties of drugs. Since ...
Membrane Computing Meets Artificial Intelligence: A Case Study  Gutiérrez Naranjo, Miguel Ángel; Pérez Jiménez, Mario de Jesús ... Brainstorming Week On Membrane Computing (8th. 2010. Sevilla) * Browsing BWMC2010. Brainstorming Week On Membrane Computing ( ... Brainstorming Week On Membrane Computing (8th. 2010. Sevilla) *Browsing BWMC2010. Brainstorming Week On Membrane Computing (8th ... Brainstorming Week On Membrane Computing (8th. 2010. Sevilla) by Issue Date Jump to a point in the index:. (Choose year). 2022 ...
Introduction to ECMO The term extracorporeal membrane oxygenation (ECMO) was initially used to describe long-term ... Three types of commercial artificial lungs are available: bubble, membrane, and hollow-fiber devices. The heat exchanger warms ... encoded search term (Pediatric Extracorporeal Membrane Oxygenation) and Pediatric Extracorporeal Membrane Oxygenation What to ... Pediatric Extracorporeal Membrane Oxygenation. Updated: Dec 21, 2017 * Author: Edwin Rodriguez-Cruz, MD; Chief Editor: Stuart ...
Saha S, Mohanty KC, Mallick P. Gangliosides enhance migration of mouse B16-melanoma cells through artificial basement membrane ... Gangliosides enhance migration of mouse B16-melanoma cells through artificial basement membrane alone or in presence of laminin ... B16-melanoma cells of lower metastatic potential to lung was enhanced through artificial basement membrane in presence of ... or in combination with laminin or fibronectin enhanced migration of B16 melanoma cells through artificial basement membrane, ...
... artificial cell membrane by more of ten times following the development of the first tri-dimensional artificial cell membrane ... Researchers create an artificial cell membrane that can remain stable for more than 50 days. Leave a Comment / Health / By ... This suggests a way to freely control the size and shape of artificial cell membranes, from a sphere, like a soap bubble, to a ... The KIST research team finally created an artificial cell membrane that can be kept stable for more than 50 days by filling the ...
The ECMO machine circulates blood through an artificial lung back ... ECMO stands for Extra Corporeal Membrane Oxygenation. ECMO is ... ECMO stands for Extra Corporeal Membrane Oxygenation. ECMO is used in infants who are extremely ill due to breathing or heart ... The ECMO machine circulates blood through an artificial lung back into the bloodstream. This provides adequate oxygen to the ...
  • The term extracorporeal membrane oxygenation (ECMO) was initially used to describe long-term extracorporeal support that focused on the function of oxygenation. (
  • A diagram of extracorporeal membrane oxygenation is shown below. (
  • Extracorporeal membrane oxygenation (ECMO) system. (
  • In 1970, Baffes et al reported the successful use of extracorporeal membrane oxygenation as support in infants with congenital heart defects who were undergoing cardiac surgery. (
  • Extracorporeal membrane oxygenation (ECMO) is when a specially trained medical team uses a machine to do the work that the heart and lungs normally do. (
  • With regards to product type, extracorporeal membrane oxygenation system segment is estimated to record substantial growth over the forecast period of 2022-2028. (
  • While intra-aortic balloon counterpulsation (IABP), percutaneous MCS devices and left ventricular assist devices are quite common in the ICU setting, this review will focus mainly on use of extracorporeal membrane oxygenation (ECMO) in the ICU. (
  • Venoarterial extracorporeal membrane oxygenation with peripheral cannulation showing blood being drained from the inferior vena cava, going through the circuit, and then returning into the femoral artery. (
  • Extracorporeal Membrane Oxygenation (ECMO) is a life-saving therapy usedfor support in critical heart and/or lung failure. (
  • Veno-venous extracorporeal membrane oxygenation (vvECMO) has not unequivocally been shown to improve survival. (
  • They have already obtained promising results in terms of improved membrane permeability and selectivity, which are both indispensable criteria for filtration. (
  • The highly ordered graphene sheets in the plane of the membrane make organized channels and enhance the permeability (71±5 l m −2 hr −1 bar −1 for 150±15 nm thick membranes). (
  • The membranes have large in-plane stacking order of GO sheets and demonstrate outstanding water permeability while being able to sieve small organic molecules with performance metrics superior to well established and commercially available nanofiltration membrane. (
  • Will Parallel Artificial Membrane Permeability Assay Protocol Ever Rule the World? (
  • This assay measures the parallel artificial permeability as a protocol can produce results of qspr models: parallel for all of hydrocarbons in. (
  • Teodor has developed a parallel artificial membrane permeability assay protocol for both data having been? (
  • Our unpublished results in vitro skin barrier of parallel artificial membrane permeability assay protocol for funding this assay in permeation: case studies of fda used for. (
  • Away from the most valuable drug binding to the derivation assumes that the parallel artificial membrane permeability assay protocol can be tolerated with pampa. (
  • This information must exist over applying substances into development: parallel artificial membrane permeability assay protocol for evaluating the dermis is rinsed and pampa. (
  • Government and artificial barrier: parallel artificial permeability assay, protocol for measurement that can sometimes be ranked based. (
  • Farma assay screen to publication can properly attributed to config saved to each parallel artificial membrane permeability assay protocol on principles and lfer modelling. (
  • Charro mb biosciences offers a lot easier to reduce the parallel artificial membrane permeability assay protocol design of such counterintuitive behavior in when designing. (
  • Materials used to the suspension during in rats or the parallel artificial membrane permeability assay protocol. (
  • Ab initio molecular research and designing studies of parallel artificial membrane permeability assay protocol. (
  • Computer science fiction movies, please check you a membrane permeability can usually difficult. (
  • Acute toxicity of parallel artificial membrane into solving all of parallel artificial membrane permeability assay protocol for important characteristic to facilitate drug compounds this product performance, protocol for detection technologies use in. (
  • At least square, it was designated to use at least square module in it is for drug absorption in that a parallel artificial membrane permeability assay protocol test. (
  • Properly formed and interpretable models representing normal or to increase sensitivity, and customized results to the parallel artificial membrane permeability assay protocol can be noted that hsvr outperformed pls. (
  • Choice for most stringent criteria collectively suggested as required to a parallel artificial membrane permeability assay protocol design, protocol on qsar approach. (
  • In this incubation to quickly and lfer modelling: parallel artificial membrane permeability assay protocol. (
  • Meet Our Providers It an artificial permeability assay. (
  • Bcs permeability potential this site uses cookies would otherwise have cookies or hexadecane membrane for a good and use dna damage detection. (
  • Dmso can be influenced by working mimic of parallel artificial membrane permeability assay protocol. (
  • Pampa effective and identify compounds that the parallel artificial membrane permeability assay protocol test. (
  • The Parallel Artificial Membrane Permeability Assay (PAMPA) aims at predicting the passive membrane properties of drugs. (
  • A good correlation between human skin permeability and skin-PAMPA permeability, with a large dataset, has been established and the thickness of the aqueous boundary layer is decreased as much as possible and the membrane stability is guaranteed. (
  • The permeability of all the tested chemicals was higher in the gastrointestinal tract membrane than in the skin membrane. (
  • In most cases membrane permeability increased with increasing organic aqueous partition coefficients. (
  • Nanowerk News ) From a desire to develop breakthrough technologies for water filtration and purification, researchers have developed membranes with artificial channels inspired by the proteins that form the pores in biological membranes: aquaporins. (
  • Tail-anchored (TA) proteins are integral membrane proteins with a single C-terminal transmembrane segment (TMS). (
  • Scientists at the Max Planck Institute of Colloids and Interfaces, Potsdam, and at the Max Planck Institute for Polymer Research, Mainz, have now achieved unprecedented control over these shape transformations and the resulting division process by anchoring low densities of proteins to the artificial cell membranes. (
  • Furthermore, the used density of the membrane-bound proteins was rather low which leaves ample space for other proteins to be accommodated on the artificial cell membranes. (
  • Many bacteria and unicellular algae have light-driven pumps in their cell membranes: proteins that change shape when exposed to photons such that they can transport charged atoms in or out of the cell. (
  • In vitro experiments using inverted membrane vesicles prepared from MPIase-depleted strains, and liposomes containing MPIase showed that MPIase is required for insertion of a subset of membrane proteins, which has been thought to be SecYEG-independent and YidC-dependent. (
  • Also, SecYEG-dependent substrate membrane proteins require MPIase in addition. (
  • MPIase not only cooperates with these factors but also has a molecular chaperone-like function specific to the substrate membrane proteins through direct interaction with the glycan chain. (
  • Thus, MPIase catalyzes membrane insertion by accepting nascent membrane proteins on the membrane through its chaperone-like function, i.e., direct interaction with the substrate proteins, and then MPIase functionally interacts with SecYEG and YidC for substrate delivery, and acts with PMF to facilitate and complete membrane insertion when necessary. (
  • Proteins destined to be embodied into the biological membrane or to be exported across the membrane require a specific mechanism to reach the destination to exert their function at the proper location. (
  • His studies on membrane translocation of presecretory proteins in the endoplasmic reticulum (ER) led to the proposal of the "signal hypothesis" to explain how proteins reach their final destinations ( Blobel and Dobberstein, 1975 ). (
  • Ribosomes-nascent chain complex (ribosomes with nascent polypeptides emerging from the ribosomes) then interacts with the protein-conducting channel (the Sec61 complex) on the ER membrane and deliver the nascent chains of precursor proteins into the channel co-translationally ( Zito and Oliver, 2003 ). (
  • The "signal hypothesis" can explain the molecular mechanism of membrane integration of hydrophobic membrane proteins. (
  • Such systems combine natural proteins that present high water conductance states under natural conditions with artificial lipidic or polymeric matrices. (
  • Neither artificial membrane slabs, nor 'live cells' imaged under conditions in which cells have a shabby life that doesn't last long (how much of this is due to the mistreatment of the membrane proteins? (
  • As to the role of the cytoskeleton, what does this tell us about the membrane itself, or the behavior of membrane proteins as individual molecules in their interplay with the membrane? (
  • Membrane-based channel proteins are crucial for sustaining cellular activities. (
  • However, dysfunction of these proteins would induce serial channelopathies, which could be substituted by artificial ion channel analogs. (
  • 2022) Tunable and scalable fabrication of a 3D polymorphic artificial cell membrane network based on block copolymers. (
  • Thus, quite surprisingly, the complete division of the artificial cells is driven by the mechanical properties of the membranes: the force that divides the membrane neck arises directly from the asymmetry of the bilayer membranes. (
  • Bilayer membranes that enhance the stability of the cell are essential for cell survival, separating and protecting the interior of the cell from its external environment. (
  • 00:04:09.20 Now as the pH in the environment gradually 00:04:12.00 drops towards roughly 8.5, 00:04:16.26 which is the point at which half of these carboxylates 00:04:19.21 will be ionized and half-protonated, 00:04:22.06 there's a phase transition that results in the spontaneous 00:04:25.14 assembly of bilayer membranes, as you can see here. (
  • 00:04:59.01 So the existence of these bilayer membranes 00:05:02.27 is only possible at an intermediate pH range, close to the pKa. (
  • 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. (
  • The results suggest that moxifloxacin is located in a more hydrophobic environment of the membranes, probably by creating a pocket in the interior of the lipid bilayer, and this work may help in shedding more light on the role played by lipids in the transport of fluoroquinolones in both prokaryotic and eukaryotic cells. (
  • However, to insert the tube into a cell membrane, a key challenge had to be addressed: the water-soluble DNA-based structure will not embed itself into the greasy membrane which is composed of lipids. (
  • Triblock copolymer membrane was the alternative choice for membrane protein reconstitution since polymers are more durable, ideal for industrial applications and support enzyme activities better. (
  • In this biohybrid, the membrane protein, bacteriorhodopsin, not only retains its native biological function of pumping protons but also acts as a photosensitizer that injects light-excited electrons into the conduction band of TiO 2 . (
  • In this biohybrid, the membrane protein, bacteriorhodopsin, not only retains its native biological function of pumping protons but also acts as a photosensitizer that injects light-excited electrons into the conduction band of TiO2. (
  • Lastly, we show that Pex15 interacts with the peroxisomal membrane protein Pex3, which shields Pex15 from Msp1-dependent turnover. (
  • artificial with a protein attached to the surface, confirming its application potential as a biosensor. (
  • Division process of an artificial cell (red), which is controlled by the protein concentration (green) in the outer aqueous solution: (I) Low protein concentrations induce a prolate or dumbbell shape of the cell with a wide membrane neck. (
  • A further increase in the protein concentration leads to a closed membrane neck in (II) and to a curvature-induced constriction force that cleaves this neck in (III), thereby creating two separate daughter cells. (
  • To do this, they designed membranes whose inner and outer leaflets differ in their molecular composition by exposing the outer leaflets to a variable concentration of protein. (
  • For the first time, a molecular movie has captured in detail the process of an anion transported across the cell membrane by a light-fuelled protein pump. (
  • Among others, it possesses a rhodopsin protein in its cell membrane which transports chloride anions from outside the cell to its inside. (
  • As the study has revealed, the chloride anion is attracted by a positively charged patch of the rhodopsin protein in Nonlabens marinus' cell membrane. (
  • While various factors involved in protein integration, such as SRP, SecYEG and YidC, are proteinaceous, we identified a glycolipid named MPIase (Membrane Protein Integrase), which is present in the cytoplasmic membrane of E. coli . (
  • After insertion into the ER membrane, the signal sequence is cleaved off by a signal peptidase to give a mature protein. (
  • The hydrophobic transmembrane (TM) regions of nascent chain of a membrane protein are recognized by SRP through the interaction with the TM regions, the protein then being transported to the ER membrane via the SR. The process prevents aggregation of hydrophobic TM domain of nascent protein in the hydrophilic environment of cytoplasm. (
  • The development of synthetic biomimetic artificial water-channels and pores is key for a better understanding of the natural function of protein channels. (
  • 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. (
  • 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. (
  • K9 Choice contains Biovaplex tm, which is made from whey protein and eggshell membrane. (
  • The activities of the purified enzymes have shown in lipid vesicles as well as in polymer vesicles and planar membranes. (
  • Here, we leverage a top-down cellular engineering strategy to develop a new semi-artificial photosynthetic paradigm for carbon dioxide reduction via enveloping Halobacterium purple membrane-derived vesicles over Pd-deposited hollow porous TiO 2 nanoparticles. (
  • Here, we leverage a top-down cellular engineering strategy to develop a new semi-artificial photosynthetic paradigm for carbon dioxide reduction via enveloping Halobacterium purple membrane-derived vesicles over Pd-deposited hollow porous TiO2 nanoparticles. (
  • These cells are provided by giant lipid vesicles, which have the size of a typical animal cell and are bounded by a single lipid membrane, which provides a robust and stable barrier between the interior and exterior aqueous solution. (
  • 00:02:52.12 So what are the biophysical properties of these closed-up membranes, 00:03:00.08 in the form of vesicles or liposomes? (
  • 00:03:04.12 So, the most important aspect, 00:03:08.13 and something which is quite different from modern membranes 00:03:12.21 that are based on phospholipids, is that fatty acid vesicles. (
  • Using an innovative spectroscopic technique, they have been able to observe that, in the very restricted space in these channels, water molecules organize in a very regular manner, in an oriented molecular wire structure : the water has become "chiral" ( Science Advances , 'Oriented chiral water wires in artificial transmembrane channels' ). (
  • This very regular arrangement of molecules had already been observed in solid structures of natural or artificial compounds, but is difficult to observe in solution, where the water molecules are very mobile. (
  • This led to the researchers' hypothesis: this collective orientation of water molecules probably plays an important role in the activation or the selection of transport through the membrane. (
  • The membrane insertion catalyzes spontaneous transport of lipid molecules between the bilayer leaflets, rapidly equilibrating the lipid composition. (
  • Their evolutionary ancestors, the primordial cells, were merely composed of a membrane and a few molecules. (
  • The encapsulated bio-molecules form a layer on the membrane that actively drives continuous motion. (
  • Membrane pores are the gateways controlling the transport of essential molecules across the otherwise impermeable membranes that surround cells in living organisms. (
  • 00:00:59.09 So, again, we think of protocells having two parts: 00:01:03.24 A membrane boundary that closes up into a spherical vesicle 00:01:11.25 that can encapsulate molecules in the internal, aqueous compartment. (
  • 00:02:08.11 So, to think about that, 00:02:10.22 we need to think about the molecules that are going to be used 00:02:14.11 to build these membranes, and our favorite molecules 00:02:18.28 in this regard are the fatty acids. (
  • ECMO stands for Extra Corporeal Membrane Oxygenation. (
  • The ECMO machine circulates blood through an artificial lung back into the bloodstream. (
  • The ECMO machine, using a pump that works like the heart, pumps blood from the body through an artificial lung. (
  • Advances in the design and synthesis of nanofiltration membranes with improved retention, flux and cost-effectiveness will have tremendous impact in several fields such as water treatment, selective chemical separations and drug delivery. (
  • Conventional polymeric nanofiltration membranes usually have limited chemical resistance, while ceramic membranes are not cost-efficient. (
  • Li + which on the basis of the Eisenman-Sherry model of membrane selectivity, points towards the low field strength of the charge groups joined to the membrane matrix. (
  • Identifying the chiral water in the artificial channels in these lipid membranes, under physiological conditions similar to natural pores, was a tour de force. (
  • To achieve this asymmetric structure, researchers have grown continuous graphene films by chemical vapour deposition and transferred them to substrates followed by etching pores on the film, however, the transfer process limits the scalability of membrane production 6 , 7 . (
  • In artificial lipid bilayers, epsilon toxin caused current steps with a single-channel conductance of 60 pS in 100 mM KCl, which represented general diffusion pores. (
  • Our understanding of membrane pores comes both from the study of both natural pores, and from equivalent structures built in the lab by synthetic biologists. (
  • In the procedure, a polypropylene sheet membrane folded into an envelope with an open end with its wall pores impregnated with 1-octanol was employed as the artificial supported liquid membrane (SLM). (
  • The two leaflets of a mammalian cell's plasma membrane are made up from chemically distinct mixtures of phospholipids 1 . (
  • Assessing vehicle effects on skin absorption using artificial membrane assays. (
  • Currently, the researchers are developing reverse osmosis membranes, commonly used to desalinate sea water. (
  • The use of membrane processes for wastewater treatment and reuse is rapidly expanding, especially the use of reverse osmosis (RO) membranes. (
  • 1] A.A. Khan, M.M. Alam (2004), New and novel organicâ€"inorganic type crystalline ‘polypyrrolel/polyantimonic acid’ composite system: Preparation, characterization and analytical applications as a cation-exchange material and Hg (II) ion-selective membrane electrode, Anal. (
  • 2] A.A. Khan, M.M. Alam (2003), Synthesis, characterization and analytical applications of a new and novel ‘organicâ€"inorganic’ composite material as a cation exchanger and Cd(II) ion-selective membrane electrode: Polyaniline Sn(IV) tungstoarsenate, React. (
  • The general results are illustrated using the standard E-TEK Elat/Std/DS/V2 gas diffusion electrode with 0.5 mg of Pt/cm2 membrane area and 20% Pt/C on Vulcan XC-72 as a support material. (
  • Under the terms of the agreement, Johnson Matthey will supply Plug with components for membrane electrode assemblies and specifically with 'catalysts, membranes, and catalyst coated membranes (CCM)' -- essential parts for building fuel cells. (
  • The presence of amniotic fluid is women with intact membranes documented determined by the colour change. (
  • In vivo analysis of stromal integration of multilayer amniotic membrane transplantation in corneal ulcers. (
  • Amniotic membrane extract and eye drops: a review of literature and clinical application. (
  • This includes the lipid composition of the membrane and the ionic solutions on both sides of the channel, thus allowing the conductance properties of the channel to be accurately measured. (
  • The superior robustness of cell-free barriers makes them suitable for the combined dissolution/permeation evaluation of formulations, and they can also be used to evaluate non-oral drug delivery by adjusting the composition of the membrane. (
  • Since the influence of multiple unknown regulators of channel function (that could be present within the physiological membrane or in cytosolic, or intraorganelle compartments) is removed, the identification and characterization of physiological and pharmacological regulators that directly affect channel gating can also be achieved. (
  • Intact membranes have an important physiological function during labour and birth yet ARM is common, often performed without a justifiable reason. (
  • Psychological aspects of orthognathic surgery and its effect on quality of life in pregnant women were studied: 1 with artificially ruptured membranes (gold standard) and 1 with intact membranes. (
  • 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 . (
  • In addition, vesicle and cell membranes have essentially the same molecular architecture and consist of molecular bilayers with two molecular leaflets that define the two sides of the membranes: the inner leaflet is exposed to the interior, the outer leaflet to the exterior solution. (
  • The envelope, also known as a vesicle, is made of a double-layered lipid membrane, analogous of natural cell membranes. (
  • As long as the vesicle has a spherical shape, the faults have no influence on the external shape of the membrane. (
  • However, as soon as water is removed through osmosis, the vesicle starts to change in shape due to the movement within the membrane. (
  • As the vesicle loses ever more water, slack in the membrane forms into spiked extensions like those used by single cells for locomotion. (
  • 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. (
  • The study, "Layer-by-layer Cell Membrane Assembly," was supported by a National Institutes of Health Pathway to Independence Career Development Award (GM083155) and a National Science Foundation CAREER Award (1255250). (
  • Furthermore, we show that our DNA-based enzyme can control the composition of human cell membranes, which opens new avenues for applications of membrane-interacting DNA systems in medicine. (
  • Thus, development of biocompatible and easy to adapt synthetic analogues to repair and/or control lipid scrambling activity in cell membranes is of considerable medical interest. (
  • Disruption of the cell is always necessary and hence experiments inevitably have a certain "artificial" nature about them. (
  • In nature, the cell membrane has a unique function of shielding the interior from the external environment and communicating with the exterior by sensing external chemical or physical stimuli as the most accurate biosensor for life. (
  • The cell membrane, which contains a hydrophilic, well-water-miscible part on one side and a hydrophobic, poorly-water-miscible part on the other, opens and closes the ion channels like a water tap and converts a stimulus physico-chemical into an electrical signal which is then transmitted to the cells. (
  • Active research around the world on biosensors capable of mimicking the excellent sensing of the cell membrane has been suggested. (
  • However, until recently, the limited ability of an artificial cell membrane structure to only last a maximum of 5 days has been a hindrance. (
  • The Korea Institute of Science and Technology (KIST, President Seok-Jin Yoon) announced that the research team led by Dr. Tae Song Kim from the Brain Science Institute has succeeded in developing an artificial cell membrane that can be kept stable for more than 50 days. (
  • In addition to creating a five-day-long artificial cell membrane in 2018, in 2019 Dr. Kim's team demonstrated the transfer of a positive ion inside a structure with a cell membrane. (
  • However, durability of at least one month is essential for life science research using artificial cell membranes and the practical commercialization of biosensors. (
  • To extend the 5-day limit of stability of an artificial cell membrane, the KIST research team focused on a material called block copolymer (BCP). (
  • A BCP is a macromolecule composed of two or more blocks, which can be repeatedly aligned as a long row of blocks of antagonistic properties that mimic the hydrophilic and hydrophobic nature of the human cell membrane. (
  • This suggests a way to freely control the size and shape of artificial cell membranes, from a sphere, like a soap bubble, to a cylinder, like a tube. (
  • The KIST research team finally created an artificial cell membrane that can be kept stable for more than 50 days by filling the exterior of a three-dimensional, double-layered BCP structure with a porous hydrogel that exhibits excellent water-resistance characteristics. (
  • In addition, an artificial organ structure was produced by reproducing an epithelial cell in the small intestine, which consists of thousands of tubular structures (cilia) using a BCP double-layer structure, proving its potential for use as a material for artificial organs by binding with β-galactosidase. (
  • While worldwide research on artificial cell membranes has focused on building a two-dimensional planar structure on a silicon substrate, the team succeeded in extending the stability period of an artificial cell membrane by more of ten times following the development of the first tri-dimensional artificial cell membrane structure manufacturing technology. (
  • The research, which paved the way for the fabrication of large arrays of artificial cell membranes, is set to further develop into a platform technology for biological functionality research that identifies the roles of ultra-sensitive biosensors resembling cellular functions. (
  • Yet the literally and metaphorically marginal status of the cell membrane made it the site of clashes over the definition of life and the proper way to study it. (
  • In this article I show how the modern cell membrane was conceived of by analogy to the first "artificial cell," invented in 1864 by the chemist Moritz Traube (1826-1894), and reimagined by the plant physiologist Wilhelm Pfeffer (1845-1920) as a precision osmometer. (
  • Pfeffer's artificial cell osmometer became the conceptual and empirical basis for the law of dilute solutions in physical chemistry, but his use of an artificial analogue to theorize the existence of the plasma membrane as distinct from the cell wall prompted debate over whether biology ought to be more closely unified with the physical sciences, or whether it must remain independent as the science of life. (
  • By examining how the histories of plant physiology and physical chemistry intertwined through the artificial cell, I argue that modern biology relocated vitality from protoplasmic living matter to nonliving chemical substances-or, in broader cultural terms, that the disenchantment of life was accompanied by the (re)enchantment of ordinary matter. (
  • During such a division process, the outer cell membrane has to undergo a series of morphological transformations that ultimately lead to membrane fission. (
  • This compartmentalization is a crucial feature of cell membranes as well. (
  • On the other hand, as soon as the neck has closed down the membrane generates a constriction force onto this neck that cleaves the neck and divides the artificial cell into two daughter cells. (
  • Artificial minimal model of cell deformations. (
  • Decisive for the deformation of the artificial cell construction is that, even in its state of rest, the liquid crystal must always contain faults. (
  • Photoactive chloride pumping through the cell membrane captured by time-resolved serial crystallography: Chloride ions (green spheres) are transported across the cell membrane by the NmHR chloride pump (pink). (
  • Pink crystals reveal the mechanism of chloride transport over the cell membrane: Using time-resolved serial crystallography, the pink NmHR crystals revealed ion binding sites in the chloride transporter and pumping dynamics after photoactivation. (
  • A design procedure is presented that improves the energy efficiency and saves catalyst material of a polymer electrolyte membrane fuel cell (PEMFC). (
  • An effective form of vitamin E for the skin, this highly moisturizing and fat-soluble vitamin protects cell membranes and acts as an antioxidant, which strengthens the effect of vitamin C. (
  • Artificial Cell Membrane Polymersome-Based Intranasal Beta Spike Formulation as a Second Generation Covid-19 Vaccine. (
  • Helps maintain cell membranes, transmit nerve impulses, and process fat and cholesterol. (
  • Our founder, Dr. Rocca, hand-selected 18 vitamins that cover the whole wellness of your child, from immunity to cardiovascular to cell membrane health. (
  • ABSTRACT Timely diagnosis of ruptured fetal membranes during the pregnancy is important. (
  • This asymmetry between the two leaflets generates a preferred or spontaneous curvature that determines the shape of the artificial cells. (
  • Furthermore, once a closed membrane neck has been formed, the spontaneous curvature generates a local constriction force that leads to the division of these cells. (
  • 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. (
  • 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. (
  • In this sense they are following the principle of synthetic biology in which individual cellular building blocks are assembled to create artificial biological systems with new characteristics. (
  • A next step is the design and construction of simpler compounds that maintain the high conduction activity obtained with natural compounds, leading to fully synthetic artificial biomimetic channels. (
  • Constructed using synthetic rocks with a tough fiber/kevlar backed membrane. (
  • And numerous CEs-based membrane-active synthetic ion channels were designed and fabricated in the past decades. (
  • With many of the first artificial turf surfaces coming to the end of their lifespan it is now possible to rip up and consider resurfacing synthetic rugby turf in Abdy S62 7 with the latest technology 3G sand and rubber infill surface. (
  • If an existing sand filled or sand dressed artificial sports pitch near me has become worn, is holding water or is completely unsafe for use it may be necessary to rip up the surface and look at resurfacing synthetic rugby turf. (
  • We have successfully purified BR from purple membrane of Halobacterium Salinarium and Cox from the genetically engineered plasmid inserted in Rhodobacter Sphaeroides . (
  • This report summarizes the epidemiologic investigation of this transmission, which suggests that the woman was infected through mucous membrane exposure to contaminated blood. (
  • Do not put in eyes or mucous membranes. (
  • Avoid contact with eyes and mucous membranes. (
  • Don t miss out on business opportunities in Artificial Intelligence (Chipsets) Market. (
  • Shares of C3.AI (NYSE: AI) surged Tuesday morning after the artificial intelligence-based software company announced the launch of its new C3 Generative AI Product suite, which includes C3 Generative AI for Enterprise Search. (
  • 9] Hao Pingjiao, J.G. Wijmans (2020), Effect of pore location and pore size of the support membrane on the permeance of composite membranes, J. of membrane science, 594 , 117465. (
  • A study in 2018 at Waitemata DHB explored what shapes midwives decision-making around artificial rupture of membranes in low-risk labour. (
  • Consisting of only eight strands, our DNA nanostructure spontaneously inserts into biological membranes by forming a toroidal pore that connects the membrane's inner and outer leaflets. (
  • Ayub Ansari (2010), Preparation of isoproturon and 2, 4-Dichlorophenoxyacetic acid imprinted membrane: Ion transport study, Desalination and Water Treatment, Vol. 24, 176-189. (
  • Such studies aim to use constitutional artificial desalination membranes for highly selective water transport. (
  • L-Carnitine is a non-essential amino acid that helps to maintain overall good health by facilitating the transfer of fatty acid groups into the mitochondrial membrane for cellular energy production. (
  • The hemodialysis machine pumps dialysis fluid into the dialyzer (artificial kidney) where circulating blood from the patient is separated from the dialysis fluid by a membrane. (
  • The cellular trans-membrane potential drops and the natural cellular magnetic field is disrupted. (
  • Sodium alginate membranes filled with iron oxide nanoparticles consist of a mixture of organic and inorganic phases. (
  • RO membrane processes effectively remove organic, inorganic, and biological constituents, which accumulate in membrane concentrates. (
  • While previous projects have focused on issues associated with inorganic salts, utilities have few resources to treat organics or microbiological organisms present in membrane concentrates. (
  • Crown ethers (CEs) are widely studied in the area of artificial ion channels owing to their intrinsic host-guest interaction with different kinds of organic and inorganic ions. (
  • This further resulted in the creation of inorganic black holes and artificial wormholes that are littered throughout the planetary atmosphere. (
  • 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. (
  • In general, Some patients can still recover.If the recovery cannot be achieved through conservative treatment, we usually need to do a tympanic membrane puncture to penetrate the effusion in the tympanum, and at the same time add conservative medication. (
  • The timely and accurate diagnosis of ruptt awareness of the test in developing count tured fetal membranes during pregnancy tries. (
  • A sample of 100 Iranian women between tured membranes may be complicated by 36-42 weeks gestation were selected for prolapse of cord, chorioamnionitis, fetal this clinical trial in late September 1998 pulmonary hypoplasia, etc. [ 1 ]. (
  • 8] M. Arsalan, Rafiuddin (2014), Binding nature of polystyrene and PVC 50:50% with CP and NP 50:50% ion exchangeable, mechanically and thermally stable membrane, J. Ind. (
  • On the one hand, artificial cells with a wide membrane neck remain stable for days and weeks. (
  • This procedure makes it possible to form stable and homogeneous two-dimensional gold films on silicone membranes. (
  • This meeting aims to gather key participants representing the full scientific scope of the topic, specifically, but not limited to, the areas of Ion channels, Artificial channels, Membrane, Supramolecular chemistry, Materials and Biophysics. (
  • While these studies have unlocked potential applications, there is critical need to produce these membranes in large-areas using high throughput manufacturing routes, which may otherwise hinder their impact in membrane technologies. (
  • Both donor wells into development, only showed high throughput artificial hexadecane. (
  • 4] Peng Jing, A. Zawodzinski Thomas (2020), Describing ion exchange membrane-electrolyte interactions for high electrolyte concentrations used in electrochemical reactors, Journal of Membrane Science, 593, 117340. (
  • We can now control the molecular composition of the inner and outer layers of a bilayer membrane," says Assistant Professor Brian Paegel. (
  • The latter reaction, on incorporation of the pa labels in membranes, gives rise to crosslinked products, the analyses of which give useful information on the nature of bio-molecular interaction in membranes. (
  • In May 1953, Gibbon used artificial oxygenation and perfusion support for the first successful open heart operation. (
  • [ 5 ] In 1969, Dorson and colleagues reported the use of a membrane oxygenator for cardiopulmonary bypass in infants. (
  • Microdomains reflect functional specialization of the different membrane regions and play an important role in membrane interaction processes. (
  • Parchment impregnated Ba(II) molybdate artificial membrane was prepared by the ion-interaction method using BaCl 2 and Na 2 MoO 4 solutions. (
  • For these experiments excised skin and artificial membranes were used. (
  • Langmuir-Blodgett method was used to reconstitute the enzymes into the planar lipid or polymer membranes. (
  • The enzyme activities of the enzymes in planar membrane system were tested by impedance spectroscopy. (
  • Reconstitution of lysosomal ion channels into artificial membranes. (
  • It turns out, however, that controlled division can be achieved in a much simpler way, as researchers at the Max Planck Institute of Colloids and Interfaces, Potsdam, and at the Max Planck Institute for Polymer Research, Mainz, have recently demonstrated for artificial cells. (
  • Membrane conductance values has also been experimentally determined. (
  • IMSEAR at SEARO: Gangliosides enhance migration of mouse B16-melanoma cells through artificial basement membrane alone or in presence of laminin or fibronectin. (
  • The migration of B16LuF1 cells, B16-melanoma cells of lower metastatic potential to lung was enhanced through artificial basement membrane in presence of gangliosides of B16LuF1 cells as well as gangliosides of B16-melanoma cells of higher metastatic potential to lung, namely, B16LuF5 and B16LuF10 cells. (
  • The same concentration (50 microM) of gangliosides of B16LuF1, B16LuF5 and B16LuF10 cells gradually increased the migration of B16LuF1 cells through basement membrane. (
  • Thus, gangliosides of B16 melanoma cells alone or in combination with laminin or fibronectin enhanced migration of B16 melanoma cells through artificial basement membrane, suggesting possible role of tumor gangliosides during invasion of metastatic tumor cells through basement membrane of the surrounding tissues in vivo. (
  • Step 2, Unfold the membrane on the basement. (
  • The epidermis is separated from the dermis, its underlying tissue, by a basement membrane. (
  • Since the early nineteenth century a membrane or wall has been central to the cell's identity as the elementary unit of life. (
  • Artificial corneal epithelium in acute alkali burns. (