Calorimetry, Differential Scanning: Differential thermal analysis in which the sample compartment of the apparatus is a differential calorimeter, allowing an exact measure of the heat of transition independent of the specific heat, thermal conductivity, and other variables of the sample.Calorimetry: The measurement of the quantity of heat involved in various processes, such as chemical reactions, changes of state, and formations of solutions, or in the determination of the heat capacities of substances. The fundamental unit of measurement is the joule or the calorie (4.184 joules). (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)Calorimetry, Indirect: Calculation of the energy expenditure in the form of heat production of the whole body or individual organs based on respiratory gas exchange.Thermodynamics: 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)Energy Metabolism: The chemical reactions involved in the production and utilization of various forms of energy in cells.Basal Metabolism: Heat production, or its measurement, of an organism at the lowest level of cell chemistry in an inactive, awake, fasting state. It may be determined directly by means of a calorimeter or indirectly by calculating the heat production from an analysis of the end products of oxidation within the organism or from the amount of oxygen utilized.Temperature: 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.Titrimetry: The determination of the concentration of a given component in solution (the analyte) by addition of a liquid reagent of known strength (the titrant) until an equivalence point is reached (when the reactants are present in stoichiometric proportions). Often an indicator is added to make the equivalence point visible (e.g., a change in color).Protein Denaturation: Disruption of the non-covalent bonds and/or disulfide bonds responsible for maintaining the three-dimensional shape and activity of the native protein.X-Ray Diffraction: The scattering of x-rays by matter, especially crystals, with accompanying variation in intensity due to interference effects. Analysis of the crystal structure of materials is performed by passing x-rays through them and registering the diffraction image of the rays (CRYSTALLOGRAPHY, X-RAY). (From McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)Circular Dichroism: A change from planar to elliptic polarization when an initially plane-polarized light wave traverses an optically active medium. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)Protein Binding: 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.Spectroscopy, Fourier Transform Infrared: A spectroscopic technique in which a range of wavelengths is presented simultaneously with an interferometer and the spectrum is mathematically derived from the pattern thus obtained.Phase Transition: A change of a substance from one form or state to another.1,2-Dipalmitoylphosphatidylcholine: Synthetic phospholipid used in liposomes and lipid bilayers to study biological membranes. It is also a major constituent of PULMONARY SURFACTANTS.Hot Temperature: Presence of warmth or heat or a temperature notably higher than an accustomed norm.Molecular Sequence Data: 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.Lipid Bilayers: Layers of lipid molecules which are two molecules thick. Bilayer systems are frequently studied as models of biological membranes.Transition Temperature: The temperature at which a substance changes from one state or conformation of matter to another.Models, Molecular: Models used experimentally or theoretically to study molecular shape, electronic properties, or interactions; includes analogous molecules, computer-generated graphics, and mechanical structures.Technology, Pharmaceutical: The application of scientific knowledge or technology to pharmacy and the pharmaceutical industry. It includes methods, techniques, and instrumentation in the manufacture, preparation, compounding, dispensing, packaging, and storing of drugs and other preparations used in diagnostic and determinative procedures, and in the treatment of patients.Powder Diffraction: Method of using a polycrystalline powder and Rietveld refinement (LEAST SQUARES ANALYSIS) of X-RAY DIFFRACTION or NEUTRON DIFFRACTION. It circumvents the difficulties of producing single large crystals.Kinetics: The rate dynamics in chemical or physical systems.Amino Acid Sequence: 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.Chemistry, Pharmaceutical: Chemistry dealing with the composition and preparation of agents having PHARMACOLOGIC ACTIONS or diagnostic use.Solubility: 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)Dimyristoylphosphatidylcholine: A synthetic phospholipid used in liposomes and lipid bilayers for the study of biological membranes.Binding Sites: The parts of a macromolecule that directly participate in its specific combination with another molecule.Water: 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)Protein Conformation: 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).Protein Structure, Tertiary: 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.Protein Folding: Processes involved in the formation of TERTIARY PROTEIN STRUCTURE.Thermogravimetry: Technique whereby the weight of a sample can be followed over a period of time while its temperature is being changed (usually increased at a constant rate).Magnetic Resonance Spectroscopy: Spectroscopic method of measuring the magnetic moment of elementary particles such as atomic nuclei, protons or electrons. It is employed in clinical applications such as NMR Tomography (MAGNETIC RESONANCE IMAGING).Molecular Conformation: The characteristic three-dimensional shape of a molecule.Phosphatidylcholines: 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.Drug Compounding: The preparation, mixing, and assembling of a drug. (From Remington, The Science and Practice of Pharmacy, 19th ed, p1814)Protein Structure, Secondary: 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.Entropy: The measure of that part of the heat or energy of a system which is not available to perform work. Entropy increases in all natural (spontaneous and irreversible) processes. (From Dorland, 28th ed)Hydrogen-Ion Concentration: 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)Crystallography, X-Ray: The study of crystal structure using X-RAY DIFFRACTION techniques. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)Drug Stability: The chemical and physical integrity of a pharmaceutical product.Excipients: Usually inert substances added to a prescription in order to provide suitable consistency to the dosage form. These include binders, matrix, base or diluent in pills, tablets, creams, salves, etc.Particle Size: Relating to the size of solids.Liposomes: 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.Body Composition: The relative amounts of various components in the body, such as percentage of body fat.Body Temperature Regulation: The processes of heating and cooling that an organism uses to control its temperature.Drug Carriers: Forms to which substances are incorporated to improve the delivery and the effectiveness of drugs. Drug carriers are used in drug-delivery systems such as the controlled-release technology to prolong in vivo drug actions, decrease drug metabolism, and reduce drug toxicity. Carriers are also used in designs to increase the effectiveness of drug delivery to the target sites of pharmacological actions. Liposomes, albumin microspheres, soluble synthetic polymers, DNA complexes, protein-drug conjugates, and carrier erythrocytes among others have been employed as biodegradable drug carriers.Oxygen Consumption: The rate at which oxygen is used by a tissue; microliters of oxygen STPD used per milligram of tissue per hour; the rate at which oxygen enters the blood from alveolar gas, equal in the steady state to the consumption of oxygen by tissue metabolism throughout the body. (Stedman, 25th ed, p346)Models, Chemical: Theoretical representations that simulate the behavior or activity of chemical processes or phenomena; includes the use of mathematical equations, computers, and other electronic equipment.Spectrometry, Fluorescence: Measurement of the intensity and quality of fluorescence.Ligands: A molecule that binds to another molecule, used especially to refer to a small molecule that binds specifically to a larger molecule, e.g., an antigen binding to an antibody, a hormone or neurotransmitter binding to a receptor, or a substrate or allosteric effector binding to an enzyme. Ligands are also molecules that donate or accept a pair of electrons to form a coordinate covalent bond with the central metal atom of a coordination complex. (From Dorland, 27th ed)Enzyme Stability: The extent to which an enzyme retains its structural conformation or its activity when subjected to storage, isolation, and purification or various other physical or chemical manipulations, including proteolytic enzymes and heat.Base Sequence: The sequence of PURINES and PYRIMIDINES in nucleic acids and polynucleotides. It is also called nucleotide sequence.Phosphatidylethanolamines: 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.RNA, Messenger: 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.Nuclear Magnetic Resonance, Biomolecular: NMR spectroscopy on small- to medium-size biological macromolecules. This is often used for structural investigation of proteins and nucleic acids, and often involves more than one isotope.Powders: Substances made up of an aggregation of small particles, as that obtained by grinding or trituration of a solid drug. In pharmacy it is a form in which substances are administered. (From Dorland, 28th ed)Time Factors: Elements of limited time intervals, contributing to particular results or situations.Energy Intake: Total number of calories taken in daily whether ingested or by parenteral routes.Rest: Freedom from activity.Molecular Structure: The location of the atoms, groups or ions relative to one another in a molecule, as well as the number, type and location of covalent bonds.Biophysical Phenomena: The physical characteristics and processes of biological systems.Gene Expression Profiling: The determination of the pattern of genes expressed at the level of GENETIC TRANSCRIPTION, under specific circumstances or in a specific cell.Membranes, Artificial: 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.Biophysics: The study of PHYSICAL PHENOMENA and PHYSICAL PROCESSES as applied to living things.Phosphatidylglycerols: 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.Spectrophotometry, Ultraviolet: Determination of the spectra of ultraviolet absorption by specific molecules in gases or liquids, for example Cl2, SO2, NO2, CS2, ozone, mercury vapor, and various unsaturated compounds. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)Oxidation-Reduction: A chemical reaction in which an electron is transferred from one molecule to another. The electron-donating molecule is the reducing agent or reductant; the electron-accepting molecule is the oxidizing agent or oxidant. Reducing and oxidizing agents function as conjugate reductant-oxidant pairs or redox pairs (Lehninger, Principles of Biochemistry, 1982, p471).beta-Cyclodextrins: Cyclic GLUCANS consisting of seven (7) glucopyranose units linked by 1,4-glycosidic bonds.Scattering, Radiation: The diversion of RADIATION (thermal, electromagnetic, or nuclear) from its original path as a result of interactions or collisions with atoms, molecules, or larger particles in the atmosphere or other media. (McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)Escherichia coli: 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.Recombinant Proteins: Proteins prepared by recombinant DNA technology.Carbonic Anhydrase II: A cytosolic carbonic anhydrase isoenzyme found widely distributed in cells of almost all tissues. Deficiencies of carbonic anhydrase II produce a syndrome characterized by OSTEOPETROSIS, renal tubular acidosis (ACIDOSIS, RENAL TUBULAR) and cerebral calcification. EC 4.2.1.-Membrane Fluidity: 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.Models, Biological: 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.Crystallization: The formation of crystalline substances from solutions or melts. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)Povidone: A polyvinyl polymer of variable molecular weight; used as suspending and dispersing agent and vehicle for pharmaceuticals; also used as blood volume expander.Microscopy, Electron, Scanning: 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.Freeze Drying: Method of tissue preparation in which the tissue specimen is frozen and then dehydrated at low temperature in a high vacuum. This method is also used for dehydrating pharmaceutical and food products.Carbohydrate Metabolism: Cellular processes in biosynthesis (anabolism) and degradation (catabolism) of CARBOHYDRATES.Membrane Lipids: 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.Mutation: 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.Spectrophotometry, Infrared: Spectrophotometry in the infrared region, usually for the purpose of chemical analysis through measurement of absorption spectra associated with rotational and vibrational energy levels of molecules. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)Surface Plasmon Resonance: A biosensing technique in which biomolecules capable of binding to specific analytes or ligands are first immobilized on one side of a metallic film. Light is then focused on the opposite side of the film to excite the surface plasmons, that is, the oscillations of free electrons propagating along the film's surface. The refractive index of light reflecting off this surface is measured. When the immobilized biomolecules are bound by their ligands, an alteration in surface plasmons on the opposite side of the film is created which is directly proportional to the change in bound, or adsorbed, mass. Binding is measured by changes in the refractive index. The technique is used to study biomolecular interactions, such as antigen-antibody binding.DNA: A deoxyribonucleotide polymer that is the primary genetic material of all cells. Eukaryotic and prokaryotic organisms normally contain DNA in a double-stranded state, yet several important biological processes transiently involve single-stranded regions. DNA, which consists of a polysugar-phosphate backbone possessing projections of purines (adenine and guanine) and pyrimidines (thymine and cytosine), forms a double helix that is held together by hydrogen bonds between these purines and pyrimidines (adenine to thymine and guanine to cytosine).Cattle: 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.Micelles: 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.Structure-Activity Relationship: 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.Gene Expression Regulation: Any of the processes by which nuclear, cytoplasmic, or intercellular factors influence the differential control (induction or repression) of gene action at the level of transcription or translation.Hydrophobic and Hydrophilic Interactions: The thermodynamic interaction between a substance and WATER.Peptides: 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.Physicochemical Phenomena: The physical phenomena describing the structure and properties of atoms and molecules, and their reaction and interaction processes.Chemistry, Physical: The study of CHEMICAL PHENOMENA and processes in terms of the underlying PHYSICAL PHENOMENA and processes.Gels: Colloids with a solid continuous phase and liquid as the dispersed phase; gels may be unstable when, due to temperature or other cause, the solid phase liquefies; the resulting colloid is called a sol.Sphingomyelins: 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.Bacterial Proteins: Proteins found in any species of bacterium.Protein Stability: The ability of a protein to retain its structural conformation or its activity when subjected to physical or chemical manipulations.Fluorescence Polarization: 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.Poloxamer: A nonionic polyoxyethylene-polyoxypropylene block co-polymer with the general formula HO(C2H4O)a(-C3H6O)b(C2H4O)aH. It is available in different grades which vary from liquids to solids. It is used as an emulsifying agent, solubilizing agent, surfactant, and wetting agent for antibiotics. Poloxamer is also used in ointment and suppository bases and as a tablet binder or coater. (Martindale The Extra Pharmacopoeia, 31st ed)Phospholipids: Lipids containing one or more phosphate groups, particularly those derived from either glycerol (phosphoglycerides see GLYCEROPHOSPHOLIPIDS) or sphingosine (SPHINGOLIPIDS). They are polar lipids that are of great importance for the structure and function of cell membranes and are the most abundant of membrane lipids, although not stored in large amounts in the system.Delayed-Action Preparations: Dosage forms of a drug that act over a period of time by controlled-release processes or technology.Solutions: The homogeneous mixtures formed by the mixing of a solid, liquid, or gaseous substance (solute) with a liquid (the solvent), from which the dissolved substances can be recovered by physical processes. (From Grant & Hackh's Chemical Dictionary, 5th ed)Sequence Homology, Amino Acid: The degree of similarity between sequences of amino acids. This information is useful for the analyzing genetic relatedness of proteins and species.Cells, Cultured: 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.Cyclodextrins: A homologous group of cyclic GLUCANS consisting of alpha-1,4 bound glucose units obtained by the action of cyclodextrin glucanotransferase on starch or similar substrates. The enzyme is produced by certain species of Bacillus. Cyclodextrins form inclusion complexes with a wide variety of substances.Surface-Active Agents: Agents that modify interfacial tension of water; usually substances that have one lipophilic and one hydrophilic group in the molecule; includes soaps, detergents, emulsifiers, dispersing and wetting agents, and several groups of antiseptics.Protein Structure, Quaternary: The characteristic 3-dimensional shape and arrangement of multimeric proteins (aggregates of more than one polypeptide chain).Fats: The glyceryl esters of a fatty acid, or of a mixture of fatty acids. They are generally odorless, colorless, and tasteless if pure, but they may be flavored according to origin. Fats are insoluble in water, soluble in most organic solvents. They occur in animal and vegetable tissue and are generally obtained by boiling or by extraction under pressure. They are important in the diet (DIETARY FATS) as a source of energy. (Grant & Hackh's Chemical Dictionary, 5th ed)Lipid Metabolism: Physiological processes in biosynthesis (anabolism) and degradation (catabolism) of LIPIDS.Cell Line: Established cell cultures that have the potential to propagate indefinitely.Proteins: 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.Protein Isoforms: Different forms of a protein that may be produced from different GENES, or from the same gene by ALTERNATIVE SPLICING.Oligonucleotide Array Sequence Analysis: Hybridization of a nucleic acid sample to a very large set of OLIGONUCLEOTIDE PROBES, which have been attached individually in columns and rows to a solid support, to determine a BASE SEQUENCE, or to detect variations in a gene sequence, GENE EXPRESSION, or for GENE MAPPING.Body Weight: The mass or quantity of heaviness of an individual. It is expressed by units of pounds or kilograms.Surface Properties: Characteristics or attributes of the outer boundaries of objects, including molecules.Fatty Acids, Nonesterified: FATTY ACIDS found in the plasma that are complexed with SERUM ALBUMIN for transport. These fatty acids are not in glycerol ester form.Nucleic Acid Denaturation: Disruption of the secondary structure of nucleic acids by heat, extreme pH or chemical treatment. Double strand DNA is "melted" by dissociation of the non-covalent hydrogen bonds and hydrophobic interactions. Denatured DNA appears to be a single-stranded flexible structure. The effects of denaturation on RNA are similar though less pronounced and largely reversible.Hydrogen Bonding: A low-energy attractive force between hydrogen and another element. It plays a major role in determining the properties of water, proteins, and other compounds.Static Electricity: The accumulation of an electric charge on a objectCarbon Dioxide: A colorless, odorless gas that can be formed by the body and is necessary for the respiration cycle of plants and animals.Dimerization: The process by which two molecules of the same chemical composition form a condensation product or polymer.Nanocapsules: Nanometer-sized, hollow, spherically-shaped objects that can be utilized to encapsulate small amounts of pharmaceuticals, enzymes, or other catalysts (Glossary of Biotechnology and Nanobiotechnology, 4th ed).Chitosan: Deacetylated CHITIN, a linear polysaccharide of deacetylated beta-1,4-D-glucosamine. It is used in HYDROGEL and to treat WOUNDS.Freezing: Liquids transforming into solids by the removal of heat.Polymers: Compounds formed by the joining of smaller, usually repeating, units linked by covalent bonds. These compounds often form large macromolecules (e.g., BIOPOLYMERS; PLASTICS).Glucose: A primary source of energy for living organisms. It is naturally occurring and is found in fruits and other parts of plants in its free state. It is used therapeutically in fluid and nutrient replacement.Anilino Naphthalenesulfonates: A class of organic compounds which contain an anilino (phenylamino) group linked to a salt or ester of naphthalenesulfonic acid. They are frequently used as fluorescent dyes and sulfhydryl reagents.Ultracentrifugation: Centrifugation with a centrifuge that develops centrifugal fields of more than 100,000 times gravity. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)Lipids: 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)Signal Transduction: 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.Reproducibility of Results: The statistical reproducibility of measurements (often in a clinical context), including the testing of instrumentation or techniques to obtain reproducible results. The concept includes reproducibility of physiological measurements, which may be used to develop rules to assess probability or prognosis, or response to a stimulus; reproducibility of occurrence of a condition; and reproducibility of experimental results.Carrier Proteins: Transport proteins that carry specific substances in the blood or across cell membranes.Nanoparticles: Nanometer-sized particles that are nanoscale in three dimensions. They include nanocrystaline materials; NANOCAPSULES; METAL NANOPARTICLES; DENDRIMERS, and QUANTUM DOTS. The uses of nanoparticles include DRUG DELIVERY SYSTEMS and cancer targeting and imaging.Reverse Transcriptase Polymerase Chain Reaction: A variation of the PCR technique in which cDNA is made from RNA via reverse transcription. The resultant cDNA is then amplified using standard PCR protocols.Cloning, Molecular: 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.Insulin: A 51-amino acid pancreatic hormone that plays a major role in the regulation of glucose metabolism, directly by suppressing endogenous glucose production (GLYCOGENOLYSIS; GLUCONEOGENESIS) and indirectly by suppressing GLUCAGON secretion and LIPOLYSIS. Native insulin is a globular protein comprised of a zinc-coordinated hexamer. Each insulin monomer containing two chains, A (21 residues) and B (30 residues), linked by two disulfide bonds. Insulin is used as a drug to control insulin-dependent diabetes mellitus (DIABETES MELLITUS, TYPE 1).Protein Multimerization: The assembly of the QUATERNARY PROTEIN STRUCTURE of multimeric proteins (MULTIPROTEIN COMPLEXES) from their composite PROTEIN SUBUNITS.Mutagenesis, Site-Directed: Genetically engineered MUTAGENESIS at a specific site in the DNA molecule that introduces a base substitution, or an insertion or deletion.Emulsions: Colloids formed by the combination of two immiscible liquids such as oil and water. Lipid-in-water emulsions are usually liquid, like milk or lotion. Water-in-lipid emulsions tend to be creams. The formation of emulsions may be aided by amphiphatic molecules that surround one component of the system to form MICELLES.Tablets: Solid dosage forms, of varying weight, size, and shape, which may be molded or compressed, and which contain a medicinal substance in pure or diluted form. (Dorland, 28th ed)Solvents: Liquids that dissolve other substances (solutes), generally solids, without any change in chemical composition, as, water containing sugar. (Grant & Hackh's Chemical Dictionary, 5th ed)Gene Expression: The phenotypic manifestation of a gene or genes by the processes of GENETIC TRANSCRIPTION and GENETIC TRANSLATION.Substrate Specificity: A characteristic feature of enzyme activity in relation to the kind of substrate on which the enzyme or catalytic molecule reacts.Cell Membrane: The lipid- and protein-containing, selectively permeable membrane that surrounds the cytoplasm in prokaryotic and eukaryotic cells.Cations: Positively charged atoms, radicals or groups of atoms which travel to the cathode or negative pole during electrolysis.Protein Unfolding: Conformational transitions of the shape of a protein to various unfolded states.Obesity: A status with BODY WEIGHT that is grossly above the acceptable or desirable weight, usually due to accumulation of excess FATS in the body. The standards may vary with age, sex, genetic or cultural background. In the BODY MASS INDEX, a BMI greater than 30.0 kg/m2 is considered obese, and a BMI greater than 40.0 kg/m2 is considered morbidly obese (MORBID OBESITY).Thermogenesis: The generation of heat in order to maintain body temperature. The uncoupled oxidation of fatty acids contained within brown adipose tissue and SHIVERING are examples of thermogenesis in MAMMALS.Sequence Alignment: 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.Blood Glucose: Glucose in blood.Dietary Carbohydrates: Carbohydrates present in food comprising digestible sugars and starches and indigestible cellulose and other dietary fibers. The former are the major source of energy. The sugars are in beet and cane sugar, fruits, honey, sweet corn, corn syrup, milk and milk products, etc.; the starches are in cereal grains, legumes (FABACEAE), tubers, etc. (From Claudio & Lagua, Nutrition and Diet Therapy Dictionary, 3d ed, p32, p277)Gymnema: A plant genus of the family ASCLEPIADACEAE.Pulmonary Gas Exchange: The exchange of OXYGEN and CARBON DIOXIDE between alveolar air and pulmonary capillary blood that occurs across the BLOOD-AIR BARRIER.Deuterium: Deuterium. The stable isotope of hydrogen. It has one neutron and one proton in the nucleus.Guanidine: A strong organic base existing primarily as guanidium ions at physiological pH. It is found in the urine as a normal product of protein metabolism. It is also used in laboratory research as a protein denaturant. (From Martindale, the Extra Pharmacopoeia, 30th ed and Merck Index, 12th ed) It is also used in the treatment of myasthenia and as a fluorescent probe in HPLC.Cholesterol: The principal sterol of all higher animals, distributed in body tissues, especially the brain and spinal cord, and in animal fats and oils.DNA Primers: Short sequences (generally about 10 base pairs) of DNA that are complementary to sequences of messenger RNA and allow reverse transcriptases to start copying the adjacent sequences of mRNA. Primers are used extensively in genetic and molecular biology techniques.Transcription, Genetic: The biosynthesis of RNA carried out on a template of DNA. The biosynthesis of DNA from an RNA template is called REVERSE TRANSCRIPTION.Adipose Tissue: Specialized connective tissue composed of fat cells (ADIPOCYTES). It is the site of stored FATS, usually in the form of TRIGLYCERIDES. In mammals, there are two types of adipose tissue, the WHITE FAT and the BROWN FAT. Their relative distributions vary in different species with most adipose tissue being white.Dose-Response Relationship, Drug: The relationship between the dose of an administered drug and the response of the organism to the drug.Mice, Inbred C57BLMethylcellulose: Methylester of cellulose. Methylcellulose is used as an emulsifying and suspending agent in cosmetics, pharmaceutics and the chemical industry. It is used therapeutically as a bulk laxative.Computer Simulation: Computer-based representation of physical systems and phenomena such as chemical processes.Muscle, Skeletal: A subtype of striated muscle, attached by TENDONS to the SKELETON. Skeletal muscles are innervated and their movement can be consciously controlled. They are also called voluntary muscles.Transcription Factors: Endogenous substances, usually proteins, which are effective in the initiation, stimulation, or termination of the genetic transcription process.Membrane Proteins: Proteins which are found in membranes including cellular and intracellular membranes. They consist of two types, peripheral and integral proteins. They include most membrane-associated enzymes, antigenic proteins, transport proteins, and drug, hormone, and lectin receptors.Desiccation: Removal of moisture from a substance (chemical, food, tissue, etc.).Amino Acid Motifs: Commonly observed structural components of proteins formed by simple combinations of adjacent secondary structures. A commonly observed structure may be composed of a CONSERVED SEQUENCE which can be represented by a CONSENSUS SEQUENCE.Peptide Fragments: Partial proteins formed by partial hydrolysis of complete proteins or generated through PROTEIN ENGINEERING techniques.Algorithms: A procedure consisting of a sequence of algebraic formulas and/or logical steps to calculate or determine a given task.Osmolar Concentration: 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.Amino Acid Substitution: The naturally occurring or experimentally induced replacement of one or more AMINO ACIDS in a protein with another. If a functionally equivalent amino acid is substituted, the protein may retain wild-type activity. Substitution may also diminish, enhance, or eliminate protein function. Experimentally induced substitution is often used to study enzyme activities and binding site properties.Rats, Sprague-Dawley: 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.Analysis of Variance: A statistical technique that isolates and assesses the contributions of categorical independent variables to variation in the mean of a continuous dependent variable.Drug Delivery Systems: Systems for the delivery of drugs to target sites of pharmacological actions. Technologies employed include those concerning drug preparation, route of administration, site targeting, metabolism, and toxicity.Salts: Substances produced from the reaction between acids and bases; compounds consisting of a metal (positive) and nonmetal (negative) radical. (Grant & Hackh's Chemical Dictionary, 5th ed)Fatty Acids: 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)Liver: A large lobed glandular organ in the abdomen of vertebrates that is responsible for detoxification, metabolism, synthesis and storage of various substances.Glycerol: A trihydroxy sugar alcohol that is an intermediate in carbohydrate and lipid metabolism. It is used as a solvent, emollient, pharmaceutical agent, and sweetening agent.Liquid Crystals: Materials in intermediate state between solid and liquid.Light: That portion of the electromagnetic spectrum in the visible, ultraviolet, and infrared range.Muramidase: A basic enzyme that is present in saliva, tears, egg white, and many animal fluids. It functions as an antibacterial agent. The enzyme catalyzes the hydrolysis of 1,4-beta-linkages between N-acetylmuramic acid and N-acetyl-D-glucosamine residues in peptidoglycan and between N-acetyl-D-glucosamine residues in chitodextrin. EC 3.2.1.17.Nitrogen: An element with the atomic symbol N, atomic number 7, and atomic weight [14.00643; 14.00728]. Nitrogen exists as a diatomic gas and makes up about 78% of the earth's atmosphere by volume. It is a constituent of proteins and nucleic acids and found in all living cells.2-Naphthylamine: A naphthalene derivative with carcinogenic action.Microscopy, Polarization: Microscopy using polarized light in which phenomena due to the preferential orientation of optical properties with respect to the vibration plane of the polarized light are made visible and correlated parameters are made measurable.DNA, Complementary: Single-stranded complementary DNA synthesized from an RNA template by the action of RNA-dependent DNA polymerase. cDNA (i.e., complementary DNA, not circular DNA, not C-DNA) is used in a variety of molecular cloning experiments as well as serving as a specific hybridization probe.Cold Temperature: An absence of warmth or heat or a temperature notably below an accustomed norm.Nucleic Acid Conformation: The spatial arrangement of the atoms of a nucleic acid or polynucleotide that results in its characteristic 3-dimensional shape.Calcium: 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.Mathematics: The deductive study of shape, quantity, and dependence. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)Polyethylene Glycols: 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.Catalytic Domain: The region of an enzyme that interacts with its substrate to cause the enzymatic reaction.Dipodomys: A genus of the family Heteromyidae which contains 22 species. Their physiology is adapted for the conservation of water, and they seldom drink water. They are found in arid or desert habitats and travel by hopping on their hind limbs.Unilamellar Liposomes: Single membrane vesicles, generally made of PHOSPHOLIPIDS.DNA-Binding Proteins: Proteins which bind to DNA. The family includes proteins which bind to both double- and single-stranded DNA and also includes specific DNA binding proteins in serum which can be used as markers for malignant diseases.Tryptophan: An essential amino acid that is necessary for normal growth in infants and for NITROGEN balance in adults. It is a precursor of INDOLE ALKALOIDS in plants. It is a precursor of SEROTONIN (hence its use as an antidepressant and sleep aid). It can be a precursor to NIACIN, albeit inefficiently, in mammals.Starch: Any of a group of polysaccharides of the general formula (C6-H10-O5)n, composed of a long-chain polymer of glucose in the form of amylose and amylopectin. It is the chief storage form of energy reserve (carbohydrates) in plants.Microscopy, Electron: 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.Immunohistochemistry: Histochemical localization of immunoreactive substances using labeled antibodies as reagents.RNA: A polynucleotide consisting essentially of chains with a repeating backbone of phosphate and ribose units to which nitrogenous bases are attached. RNA is unique among biological macromolecules in that it can encode genetic information, serve as an abundant structural component of cells, and also possesses catalytic activity. (Rieger et al., Glossary of Genetics: Classical and Molecular, 5th ed)

Calorimetric studies on the stability of the ribosome-inactivating protein abrin II: effects of pH and ligand binding. (1/2195)

The effects of pH and ligand binding on the stability of abrin II, a heterodimeric ribosome-inactivating protein, and its subunits have been studied using high-sensitivity differential scanning calorimetry. At pH7.2, the calorimetric scan consists of two transitions, which correspond to the B-subunit [transition temperature (Tm) 319.2K] and the A-subunit (Tm 324.6K) of abrin II, as also confirmed by studies on the isolated A-subunit. The calorimetric enthalpy of the isolated A-subunit of abrin II is similar to that of the higher-temperature transition. However, its Tm is 2.4K lower than that of the higher-temperature peak of intact abrin II. This indicates that there is some interaction between the two subunits. Abrin II displays increased stability as the pH is decreased to 4.5. Lactose increases the Tm values as well as the enthalpies of both transitions. This effect is more pronounced at pH7.2 than at pH4.5. This suggests that ligand binding stabilizes the native conformation of abrin II. Analysis of the B-subunit transition temperature as a function of lactose concentration suggests that two lactose molecules bind to one molecule of abrin II at pH7.2. The presence of two binding sites for lactose on the abrin II molecule is also indicated by isothermal titration calorimetry. Plotting DeltaHm (the molar transition enthalpy at Tm) against Tm yielded values for DeltaCp (change in excess heat capacity) of 27+/-2 kJ.mol-1.K-1 for the B-subunit and 20+/-1 kJ.mol-1.K-1 for the A-subunit. These values have been used to calculate the thermal stability of abrin II and to surmise the mechanism of its transmembrane translocation.  (+info)

Expression and characterization of the intact N-terminal domain of streptokinase. (2/2195)

Proteolytic studies have enabled two of the three putative domains of the fibrinolytic protein streptokinase to be isolated and characterized (Conejero-Lara F et al., 1996, Protein Sci 5:2583-2591). The N-terminal domain, however, could not be isolated in these experiments because of its susceptibility to proteolytic cleavage. To complete the biophysical characterization of the domain structure of streptokinase we have overexpressed, purified, and characterized the N-terminal region of the protein, residues 1-146. The results show this is cooperatively folded with secondary structure content and overall stability closely similar to those of the equivalent region in the intact protein.  (+info)

The effects of hydrostatic pressure on ribosome conformation in Escherichia coli: and in vivo study using differential scanning calorimetry. (3/2195)

Differential scanning calorimetry of whole Escherichia coil cells allowed the detection in vivo of changes in ribosome conformation. This enabled for the first time an analysis of the effects of high hydrostatic pressures on ribosomes in living cells. A correlation was observed between loss of cell viability and decrease in ribosome-associated enthalpy in cells subjected to pressures of 50-250 MPa for 20 min. Cell death and ribosome damage were therefore closely related phenomena. In pressure-treated cells, the thermogram peak temperatures decreased, suggesting that the remaining ribosomes had adopted a less stable conformation. During subsequent incubation of the cultures at 37 degrees C, peak temperatures and enthalpies gradually increased over a period of 5 h. This change in ribosome conformation had no apparent effect on cell survival, as viability continued to decrease. The addition of 5 mM MgCl2 before pressure treatment of cells prevented the reduction in stability of surviving ribosomes but had no effect on the initial loss of enthalpy or on cell viability.  (+info)

Glycosylation of asparagine-28 of recombinant staphylokinase with high-mannose-type oligosaccharides results in a protein with highly attenuated plasminogen activator activity. (4/2195)

The properties of recombinant staphylokinase (SakSTAR) expressed in Pichia pastoris cells have been determined. The single consensus N-linked oligosaccharide linkage site in SakSTAR (at Asn28 of the mature protein) was occupied in approximately 50% of the expressed protein with high-mannose-type oligosaccharides. The majority of these glycans ranged in polymerization state from Man8GlcNAc2 to Man14GlcNAc2, with the predominant species being Man10GlcNAc2 and Man11GlcNAc2. Glycosylated SakSTAR (SakSTARg) did not differ from its aglycosyl form in its aggregation state in solution, its thermal denaturation properties, its ability to form a complex with human plasmin (hPm), the amidolytic properties of the respective SakSTAR-hPm complexes, or its ability to liberate the amino-terminal decapeptide required for formation of a functional SakSTAR-hPm plasminogen activator complex. However, this latter complex with SakSTARg showed a greatly reduced ability to activate human plasminogen (hPg) as compared with the same complex with the aglycosyl form of SakSTAR. We conclude that glycosylation at Asn28 does not affect the structural properties of SakSTAR or its ability to participate in the formation of an active enzymatic complex with hPm, but it is detrimental to the ability of the SakSTAR-hPm complex to serve as a hPg activator. This is likely due to restricted access of hPg to the active site of the SakSTARg-hPm complex.  (+info)

Hydrocarbon chain packing and the effect of ethanol on the thermotropic phase behavior of mixed-chain phosphatidylglycerols. (5/2195)

Previous studies in this laboratory have delineated the relationship between the acyl chain asymmetry of mixed-chain phosphatidylcholines and the effect of ethanol concentration ([EtOH]) on their melting behavior (Li et al., Biophys J., 70 (1996) 2784-2794). This present investigation extends these findings to another phospholipid family by using high-resolution differential scanning calorimetry (DSC) to characterize the effect of ethanol concentration on the main phase transition temperature (Tm) of five molecular species of mixed-chain phosphatidylglycerol (PG). For C(14):C(18)PG, C(15):C(17)PG, C(16):C(16)PG, and C(17):C(15)PG, a biphasic profile in the Tm versus [EtOH] plot was observed, and the minimum in the plot for each PG occurred at 33, 15, 19, and 36 mg/ml, respectively. This biphasic behavior is typical of phospholipids whose acyl chain asymmetry is fairly small. For C(18):C(14)PG, only a linear decrease in the Tm was observed as a function of ethanol concentration; this effect is characteristic of highly asymmetric phospholipids. Our DSC results obtained with mixed-chain PG in the presence of ethanol demonstrate that the acyl chain asymmetry of the five lipids studied can be ranked as follows: C(15):C(17)PG+info)

Thermotropic phase behavior of mixed-chain phosphatidylglycerols: implications for acyl chain packing in fully hydrated bilayers. (6/2195)

In this communication we report the first systematic investigation of the thermodynamic properties of fully hydrated mixed-chain phosphatidylglycerols (PG) using high-resolution differential scanning calorimetry (DSC). The crystal structure of dimyristoylphosphatidylglycerol shows an acyl chain conformation that is nearly opposite to that of phosphatidylcholine (PC). In PC, the sn-1 chain is straight while the sn-2 chain contains a bend; for PG, the sn-1 contains a bend while the sn-2 chain is in the all-trans conformation (R.H. Pearson, I. Pascher, The molecular structure of lecithin dihydrate, Nature, 281 (1978) 499-501; I. Pascher, S. Sundell, K. Harlos, H. Eibl, Conformational and packing properties of membrane lipids: the crystal structure of sodium dimyristoylphosphatidylglycerol, Biochim. Biophys. Acta, 896 (1987) 77-88). If the structure of PG found in the single crystal can be extrapolated to that in the fully hydrated gel-state bilayer, the observed difference in acyl chain conformations implies that modulation of the acyl chain asymmetry will have an opposite effect on the thermotropic phase behavior of PG and PC. For example, it is expected, based on the crystal structures, that C(15):C(13)PG should have a higher main phase transition temperature (Tm) than C(14):C(14)PG, and C(13):C(15)PG should have a lower Tm than C(14):C(14)PG. However, our DSC studies show clearly that the expectation is not borne out by experimental data. Rather, the Tm values of C(15):C(13)PG, C(14):C(14)PG, and C(13):C(15)PG are 18.2 degrees C, 23.1 degrees C, and 24.4 degrees C, respectively. Several other PGs, each with a unique acyl chain composition, have also been studied in this laboratory using high-resolution DSC. It is shown that the acyl chain conformation of fully hydrated PG in general is nearly opposite to that seen in the PG crystal structure.  (+info)

An ordered metastable phase in hydrated phosphatidylethanolamine: the Y-transition. (7/2195)

By using time-resolved X-ray diffraction, differential scanning calorimetry and scanning densitometry, we observed rapid formation at low temperature of a metastable ordered phase, termed LR1 phase, in fully hydrated dihexadecylphosphatidylethanolamine (DHPE). The LR1 phase has the same lamellar repeat period as the gel Lbeta phase but differs from the latter in its more ordered, orthorhombic hydrocarbon chain arrangement. It forms at about 12 degrees C upon cooling and manifests itself as splitting of the sharp, symmetric wide-angle X-ray peak of the DHPE gel phase into two reflections. This transition, designated the 'Y-transition', is readily reversible and proceeds with almost no hysteresis between cooling and heating scans. Calorimetrically, the LR1-->Lbeta transition is recorded as a low-enthalpy (0.2 kcal/mol) endothermic event. The formation of the LR1 phase from the gel phase is associated with a small, about 2 microl/g, decrease of the lipid partial specific volume recorded by scanning densitometry, in agreement with a volume calculation based on the X-ray data. The formation of the equilibrium Lc phase was found to take place from within the LR1 phase. This appears to be the only observable pathway for crystallisation of DHPE upon low-temperature incubation. Once formed, the Lc phase of this lipid converts directly into Lbeta phase at 50 degrees C, skipping the LR1 phase. Thus, the LR1 phase of DHPE can only be entered by cooling of the gel Lbeta phase. The data disclose certain similarities between the low-temperature polymorphism of DHPE and that of long-chain normal alkanes.  (+info)

Thermodynamics of the reconstitution of tuna cytochrome c from two peptide fragments. (8/2195)

Two peptide fragments from tuna cytochrome c (cyt c), N-fragment (residues 1-44 containing the heme) and C-fragment (residues 45-103), combine to form a 1:1 fragment complex. This was clearly proved by ion-spray mass spectrometry. It was found from CD and NMR spectra that the structure of the fragment complex formed is similar to that of an intact cyt c, although each isolated fragment itself is unstructured. Binding constants and enthalpies upon the complex formation were directly observed by isothermal titration calorimetry. Thermodynamic parameters (deltaG(o)b, deltaHb, deltaS(o)b, and deltaC(b)p)) associated with the complex formation were determined at various pHs and temperatures. DeltaHb was found to be almost independent of pH values. The change in heat capacity accompanying the complex formation (deltaC(b)p) was directly determined from the temperature dependence of deltaHb. In addition, the change in heat capacity and enthalpy upon tuna cyt c unfolding were determined by differential scanning calorimetry. Thermodynamic parameters for the unfolding/dissociation process of the fragment complex were compared with those for cyt c unfolding at pH 3.9 and 303 K. In a comparison of two unfolding processes, the heat capacity change of each was very close to the other, while both the unfolding enthalpy and entropy of the fragment complex were larger than those of tuna cyt c. These thermodynamic data suggest that the internal interactions between polar groups (hydrogen bonding) and nonpolar groups (van der Waals interactions) are preserved in the fragment complex as well as in the native state of cyt c.  (+info)

We investigated the thermotropic phase behavior of the distearoylphosphatidylcholine (DSPC)-cholesterol binary bilayer membrane as a function of the cholesterol composition (X(ch)) by fluorescence spectroscopy using 6-propionyl-2-(dimethylamino)naphthalene (Prodan) and differential scanning calorimetry (DSC). The fluorescence spectra, each of which has a single maximum, showed that the wavelength at the maximum intensity (lambda(max)) changed depending on the bilayer state: ca. 440 nm for the lamellar gel (L(beta) or L(beta)) and the liquid ordered (L(o)) phases, ca. 470 nm for the ripple gel (P(beta)) phase and ca. 490 nm for the liquid crystalline (L(alpha)) phase, respectively. The transition temperatures were determined from the temperature dependences of the lambda(max) and endothermic peaks of the DSC thermograms. Both measurements showed that the pretransition disappears around X(ch)=0.035. The constructed temperature-X(ch) phase diagram indicated that the phase behavior of the binary ...
Wet milling by a multi-ring media mill was carried out for aqueous slurries of Mg(OH)2 and TiO2 powder mixtures in the concentration range from 6.9 to 50 wt%. Rings used as grinding media were made of partially stabilized zirconia or polyoxymethylene. Products were characterized by thermogravimetry-differential thermal analysis, X-ray diffractometry and EPMA. ZrO2 contamination in the product was determined by X-ray flurescence analysis. The temperature of endothermic peaks of dehydration remained almost unchanged regardless of slurry concentration but decreased with increasing compressive force exerted by grinding rings. The homogeneity of the product is correlated with the temperature of exothermic peaks above 1100 K due to the crystallization of MgTiO3, but not with the endothermic peaks around 650 K. The increase of the slurry concentration increases the homogeneity of the product, facilitating the formation of single-phase MgTiO3 on subsequent heating. The increase of the compressive force of
31 P-NMR and Differential Scanning Calorimetry Studies for Determining Vesicleâ s Drug Physical State and Fraction in Alendronate Liposomes Abstract.
Sodium chloride, the same substance that you sprinkle on your french fries for lunch, is a useful chemical. One of its most useful qualities is heat absorption. Salt -- the more common name for sodium chloride -- is a crystal that can absorb heat very effectively because of its particular physical and chemical ...
The objective of this science fair project is to observe the differences in heat absorption for darker colors vs. lighter colors.
Reversible transition of the ZP meshwork status by substitution treatment with dcp11 and gpp2.(a) RCAI staining of the VE substitutionally treated with dcp11 an
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Differential Scanning Calorimetry (DSC) data is used to advance stable and developable proteins into the pipeline, while optimising process and formulation conditions to maintain stability between manufacture and storage.. In 2017, Malvern launched the new MicroCal PEAQ-DSC Automated System, which has new features such as PEAQ-compliance, performance increases, smart experimental design and analysis software, and an autosampler.. This free whitepaper discusses eight reasons why you should update your MicroCal VP-Capillary DSC to the new system, including topics such as DSC data analysis in the regulated environment, increasing DSC productivity, experimental sample and scan set-up, automated objective data analysis, and objective study of data for compareability and biosimilarity studies.. ...
Figure 3 confirms the existence of a disordered structure both below and above the transition temperature as detected by the DSC experiment. The temperature evolution of the structure of the liquid has been followed looking at the Q position of the first maximum (around Q=13 nm-1) and minimum (around Q=4 nm-1) of I(Q) respectively identified as positions QA and QB.The Q values of these two points, reported as a function of temperature in the insets of Figure 3, show a jump at the temperatures corresponding to the LTL-HTL transition, as derived by the DSC measurements. The three transition temperatures for the maxima (full triangle) and the minima (full stars) of I(Q) reported on the phase diagram of Figure 2 show good agreement.. The combination of DSC and X-ray diffraction allowed us to draw the phase diagram of a solution undergoing inverse melting and to characterise the two different microscopic local structures of the disordered fluid phases, the LTL and the HTL observed in the low ...
Theory Seminar: Probing Gravitational Waves from First-Order Phase Transitions at eLISA Monday, 29 February 2016 from 12:00 to 13:00 (Europe/...
Using differential scanning calorimetry (DSC) and plate count (PC), growth of Escherichia coli was measured in four initial E. coli cell concentrations cultured in tryptic soy broth (TSB) at 35C. The calorimeter measured the energy released and/or absorbed by E. coli cells during growth and expressed it as thermograms. The resulting thermograms accurately reflected cell growth and activity, and exhibited a close correlation with growth values recorded by PC. Heat release decreased notably in the final stage of the logarithmic growth phase, and no signal was generated once the stationary phase had begun. DSC accurately quantified growth in E. coli at different initial cell concentrations grown in TSB at 35C. Depending on initial E. coli concentration, DSC detected growth starting after just a few minutes and up to five hours. The detection limit of calorimeter was 4.3 0.4 log10 CFU. DSC is an effective alternative method for measuring bacterial growth in TSB in real time. This is the first report ...
PAPER Polar phase transitions in heteroepitaxial stabilized La0.5Y0.5AlO3 thin films Shenghua Liu1, Chunfeng Zhang1, Mengya Zhu1, Qian He2, Jak Chakhalian3, Xiaoran Liu3,4, Albina Borisevich2, Xiaoyong Wang1 and Min Xiao1,4 Published 1 September 2017 • © 2017 IOP Publishing Ltd Journal of Physics: Condensed Matter, Volume 29, Number 40 Article PDF Figures References PDF 18 Total downloads Turn on MathJax Get permission to re-use this article Share this article Article information Abstract We report on the fabrication of epitaxial La0.5Y0.5AlO3 ultrathin films on (001) LaAlO3 substrates. Structural characterizations by scanning transmission electron microscopy and x-ray diffraction confirm the high quality of the film with a − b + c − AlO6 octahedral tilt pattern. Unlike either of the nonpolar parent compound, LaAlO3 and YAlO3, second harmonic generation measurements on the thin films suggest a nonpolar-polar phase transition at T c near 500 K, and a polar-polar phase transition at T a ...
Differential scanning calorimetric thermograms of oxatomide (1), β-cyclodextrin (2), physical mixture (3), kneaded mixture (4), coevaporated (5), freeze-dried
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A number of compositions of ceramic oxide high T(sub c) superconductors were elevated for their glass formation ability by means of rapid thermal analysis during quenching, optical, and electron microscopy of the quenched samples, and with subsequent DSC measurements. Correlations between experimental measurements and the methodical composition changes identified the formulations of superconductors that can easily form glass. The superconducting material was first formed as a glass; then, with subsequent devitrification, it was formed into a bulk crystalline superconductor by a series of processing methods.. ...
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When gases evolve during a chemical reaction, a fraction of the reaction heat is lost with them. We have analyzed, both theoretically and experimentally, the deviations that this effect can produce on the determination of the reaction heat by differential scanning calorimetry (DSC). It is shown that, even in the absence of gas overheating, deviations related to variations in the sample heat capacity can be substantial in experiments involving very intense DSC peaks. However, experiments performed on thermal decomposition of metal organic salts and on evaporation of liquids have shown that deviations usually arise from gas ...
Flash Differential Scanning Calorimetry revolutionizes rapid-scanning DSC. The Flash DSC 1 can analyze reorganization processes that were previously impossible to measure.
A method and apparatus for simultaneous differential scanning calorimetry and microdielectrometry is disclosed. The apparatus includes a sample cell containing a sensor for measuring the dielectric and thermal properties of the sample. The method applies a voltage to a material while heating the material over a temperature range and then simultaneously measuring the current gain of the material, the temperature of the material and the energy input to the material.
The catalytic effects of MnFe2O4 nanoparticles on the dehydrogenation properties of NaAlH4, prepared by ball milling, are investigated. The onset temperatures for NaAlH4 + 7 mol% MnFe2O4 are 95 C, 152 C and 327 C for the ...
A dense article that includes a dense TFE copolymer film is provided. The dense TFE copolymer film includes a first endotherm between about 50 C. and about 300 C., a second endotherm between about 320 C. and about 350 C., and a third endotherm between about 350 C. and about 400 C. To form the dense article, a core shell TFE copolymer is formed into a pellet, ram extruded into a tape, dried into a dried preform, and then stretched into a dense TFE copolymer film that exhibits improved physical and mechanical properties. The dense TFE copolymer film is produced directly from the dried preform at a deformation temperature less than about 335 C. and without increasing the porosity of the dried preform, as would conventionally be done in expansion processes. The dense TFE copolymer films have a methane permeability less than about 20 μg*micron/cm2/min. The dense articles have a void volume less than about 20%.
Metal roofs are excellent materials that have excellent durability and exceptoinal performance. However, how can you reduce their heat absorption?
Polymer chain motion was not restricted by the ORMOGLASS and two different phases were present in contrast to what was previously observed in ormoglass coated PLA.17 Differential scanning calorimetry (DSC) results showed that the thermal properties of the polymer were globally not affected by the incorporation of the ORMOGLASS. In fact, the thermograms of the hybrid fibers associated with the first heating ramp were similar to those of PLA fibers. Moreover, based on the second heating ramps, no significant differences in Tg were observed for the PLA and the hybrid fibers, as expected (Fig. S4, ESI†). Interactions at the nanometric level can be created thanks to the intrinsic advantages of the fabrication method,24 but no strong chemical interactions, able to induce significant modifications in Tg, were formed. Note that Tg in this amorphous PLDLLA (70% LL/30% LD PLA) ranges between 55 and 60 °C and basically depends on the molecular weight.25 The higher the ORMOGLASS content, the earlier the ...
By Darcy Simonis, ABB Food and beverage production requires a large range of temperatures. This means that plants must have effective cooling systems to deal with the excess heat. Removing the excess heat from the system requires a cooling tower, however, traditional designs require frequent maintenance
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By simulating from a half-gel starting structure, we are able to determine accurately the phase transition temperature of pentadecanes with the optimized L-OPLS parameters (Siu et al., JCTC 2012 ...
TY - JOUR. T1 - Structural Phase Transitions at Clean and Metal-Covered Si(111) Surfaces Investigated by Rheed Spot Analysis. AU - Hasegawa, Shuji. AU - Nagai, Yasuyoshi. AU - Oonishi, Toshio. AU - Kobayashi, Nobuhiko. AU - Miyake, Takashi. AU - Murakami, Shuuichi. AU - Ishii, Yuuji. AU - Hanawa, Daiki. AU - Ino, Shozo. PY - 1995/3/1. Y1 - 1995/3/1. N2 - Structural phase transitions between various kinds of superlattice structures formed on a Si(111) surface have been investigated by spot analysis of reflection high-energy electron diffraction (RHEED). Reversible transitions induced by temperature changes and irreversible ones induced by metal depositions were observed. Detailed discussions on the dynamics of the phase transitions are made by quantitative analyses of integrated spot intensity and profile. For a phase transition of 7x7âŸ1x1 structures on a clean Si(111) surface, a hysteresis with temperature difference of 5° C between in heating and cooling processes was found in the spot ...
Paracetamol is a sparingly soluble bitter tasting drug. It is widely used as an analgesic and antipyretic. Complexation of drug with different cyclodextrins (?, ? and HP-?-CD) was attempted to improve solubility of Paracetamol. During the drug excipient interaction studies, ?, ? cyclodextrins elicited analytical interference and showed considerable absorbance at ?max (243.5 nm) of Paracetamol while the ones constituting of hydroxypropyl-beta-cyclodextrin (HP-?-CD) did not show any such interference. Therefore, the present study is concentrated on exploring HP-?-CD as complexing agent. Phase solubility studies showed that complexation of Paracetamol/HP-?-CD at molar ratio 1:1 and showed AL type solubility curve. Complexation was done by various methods like physical mixing, kneading and freeze drying and resulting drug complexes were characterized by Differential Scanning Calorimetry (DSC) and Fourier Transform Infrared Spectroscopy (FTIR). The thermograms obtained showed an endothermic peak for
Polyester-like thermoplastic products obtained as a result of the reaction between lignins and terephthaloyl chrolide were examined. Steam exploded lignin (L) and sodium lignosulphonates (LS) were modified with terephthaloyl chloride. Some molecular and thermal properties of lignin modificates were determined. As a result of TG analysis it can be stated that modified product have higher temperature of a maximum weight loss than initial lignins. In thermograms of the initial lignins only endothermic peaks at 124 and 121°C for LS and 111°C for L can be observed. In case of modified LS the additional enothermic peak at 401°C is noticed. It is probably caused by thermal decomposition of the products. For modified product of LS an exothermic peaks at 313°C is observed. Molecular properties of lignins and products of their modification were evaluated using gel permeation chromatography (GPC). Due to GPC application a comparison of molecular weight distribution both for lignins and for products of ...
Polyester-like thermoplastic products obtained as a result of the reaction between lignins and terephthaloyl chrolide were examined. Steam exploded lignin (L) and sodium lignosulphonates (LS) were modified with terephthaloyl chloride. Some molecular and thermal properties of lignin modificates were determined. As a result of TG analysis it can be stated that modified product have higher temperature of a maximum weight loss than initial lignins. In thermograms of the initial lignins only endothermic peaks at 124 and 121°C for LS and 111°C for L can be observed. In case of modified LS the additional enothermic peak at 401°C is noticed. It is probably caused by thermal decomposition of the products. For modified product of LS an exothermic peaks at 313°C is observed. Molecular properties of lignins and products of their modification were evaluated using gel permeation chromatography (GPC). Due to GPC application a comparison of molecular weight distribution both for lignins and for products of ...
High sensitivity differential scanning calorimetry (d.s.c.) and uv-visible spectrophotometry have been used to study the thermal unfolding of alpha-chymotrypsin in presence of calcium chloride at pH = 2.8, 3.4, 5.0, 7.0, and 8.2. Quantitative thermodynamic parameters accompanying the thermal transitions have been evaluated. In the absence of calcium ions, the thermal denaturation of a-chymotrypsin is a reversible process giving a ratio of the vant Hoff to calorimetric enthalpy of 0.92 at pH = 2.8. At pH values higher than 5.0, the thermal denaturations in the absence of calcium chloride were observed to be completely irreversible. In the presence of calcium chloride, alpha-chymotrypsin undergoes irreversible thermal denaturation and its thermal transitions are found to be scan-rate dependent fitting to the model N-2 --, I, yielding an average activation energy of (419 +/- 16) kJ (.) mol(-1) using different approaches at pH = 2.8. It is also observed that at pH 2.8 and 3.4, calcium reduces the ...
For this endpoint one study is available. The explosive properties of the test item were assessed according to Regulation EC No. 440/2008 Method A.14. Explosive Properties and OECD Test Guideline 113 (1981): Thermal Stability (DSC measurement). In the DSC-measurement the energy of the exothermic decomposition of the test item was , -500 J/g. The onset temperature for the exothermic decomposition was 350°C. Therefore, further tests for explosive properties had not to be performed. It is concluded that the test item has no explosive properties. ...
This article reports the temperature dependence of the structural and photoelectrical properties of C60 thin films with varying crystal structure and oxygen content near the orientational disorder/order phase transition at about 260 K. X-ray diffraction data demonstrate that highly crystalline oxygen-free C60 films undergo the first-order phase transition at 252 K with a lattice parameter discontinuity Δa/a of 0.22%; no discontinuity was observed in C60 films with coexisting amorphous and nanocrystalline phases. A strong effect of the phase transition on the dark- and photoconductivity in those films is presented: In highly crystalline C60 films both dark- and photoconductivity increase as the temperature is lowered through the transition region. However, opposite temperature changes of the conductivity are observed in nanocrystalline/amorphous C60 films. In situ exposure of samples to oxygen gas suppresses any critical behavior. The experimental results are interpreted in terms of ...
TY - JOUR. T1 - Fabrication and characterization of a solid polymeric electrolyte of PAN-TiO2-LiClO4 AU - Abd Rahman, Mohd Yusri. AU - Ahmad, Azizan. AU - Ismail, L. H C. AU - Mat Salleh, Muhamad. PY - 2010/2/15. Y1 - 2010/2/15. N2 - The ionic conductivity of PAN-TiO2-LiClO4 as a function of TiO2 concentration and temperature has been reported. The electrolyte samples were prepared by solution casting technique. Their conductivity was measured using the impedance spectroscopy technique. The highest room temperature conductivity of 1.8 × 10-4 S cm-1 was obtained at 7.5 wt % of TiO2 filler. It was observed that the relationship between temperature and conductivity were linear, fitting well in Arrhenius and not in Vogel-Tamman-Fulcher equation. The pre-exponential factor, σ0 and Ea are 1.8 × 10-4 S cm-1 and 0.15 eV, respectively. The conductivity data have been supported by differential scanning calorimeter (DSC) analysis. DSC analysis showed that there was a significant change in glass ...
Dortmund Data bank - Thermophysical Properties | Benzene, CAS Number: 71-43-2 | 1-Propanol, CAS Number: 71-23-8 | SpringerMaterials 2014
An endotherm (from Greek ἔνδον endon "within" and θέρμη thermē "heat") is an organism that maintains its body at a metabolically favorable temperature, largely by the use of heat set free by its internal bodily functions instead of relying almost purely on ambient heat. Such internally generated heat is mainly an incidental product of the animals routine metabolism, but under conditions of excessive cold or low activity an endotherm might apply special mechanisms adapted specifically to heat production. Examples include special-function muscular exertion such as shivering, and uncoupled oxidative metabolism such as within brown adipose tissue. Only birds and mammals are extant universally endothermic groups of animals. Certain lamnid sharks, tuna and billfishes are also endothermic. In common parlance, endotherms are characterized as "warm-blooded". The opposite of endothermy is ectothermy, although in general, there is no absolute or clear separation between the nature of ...
A paper structure having at least three regions is disclosed. The paper structure has a first region, a patterned second region, and a third transition region connecting the first and second regions. The first and second regions are disposed at different elevations, and can each have a thickness less than a thickness of the transition region. An apparatus and process for making such a paper structure are also disclosed.
This is also reflected in the solubility versus temperature phase diagram (Fig. 3A), which shows a region of concentrations where the HB oligomer is unstable (below the dashed purple line and above the black solubility line) and a region where the oligomer is metastable (above the dashed purple line). Similar arguments can be made for the other metastable phases, such as the two, three, and four β-sheet fibril phases. We emphasize that we did not calculate free energies as we were able to calculate the solubilities directly; the discussion here is mainly presented for pedagogical purposes.. Knowledge of the thermodynamically stable and metastable phases in the phase diagram allows us to determine the conditions under which the oligomer or fibril can form. A previous discontinuous molecular dynamics (DMD) study of Aβ16-22 kinetic aggregation by Cheon et al. (6) found that at 20 mM and T* = 0.2, corresponding to 342 K, a system of peptides in a random configuration first forms a fibril nucleus, ...
FT-IR and 2D correlation spectroscopy were employed to study the microstructural changes ocurring during phase transitions of a liquid crystal poly(amidoamine) codendrimer (PAMAM (L1)16(L2)16) generation 3, functionalized on the terminal groups by one-chain promesogenic calamitic units (4-(4-decyloxybenzoyloxy)salicylaldehyde (L1)) and two-chain promesogenic calamitic units (4-(3,4-didecyloxybenzoyloxy)salicylaldehyde (L2)). Spectral modifications associated with molecular conformation rearangements allowing for molecular shape change on going from a liquid−crystalline organization to another were found. The transition temperatures were calculated, and they are in good agreement with the DSC data. Spectral analysis gives evidence of the LC phase transitions and to an additional transition associated with the existence of conformers. Various types of hydrogen bonding have been established ...
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Thermogram of a cat. The different colours represent different temperatures. The lightest colours are the hottest temperatures, while the darker colours represent cooler temperatures. Thermography uses special cameras that can detect light in the far-infrared range of the electromagnetic spectrum (900-14,000 nanometers or 0.9-14 µm) to create an image that represents an objects temperature. - Stock Image Z934/0730
Industrially textured PLA multifilaments were heat set under different conditions at 110 ºC for 1 min and subjected to one cycle of deformation up to 20%. Thermal transitions of the original textured, heat set and cyclic strained filaments were measured using differential scanning calorimetry from 25 to 250 ºC. Cyclic deformation induces an endo-exo transition at peak temperatures between 55 - 60 ºC that is not observed in the original textured and heat set multifilaments. There is another endo-exo transition with peak temperatures between 67 and 72 ºC in all filaments, the intensity of which varies according to texturing conditions, heat setting and cycle strain. Texturing conditions, heat setting and cyclic strain play a role in thermal transitions, the strain at breaking and elastic properties of the filaments. The crystallinity and magnitude of the endo-exo thermal events detected by DSC are related to the strain at breaking and elasticity of polylactide textured ...
You may also wish to search for items by Massalska-Arodz. 7 matching references were found. Rachwalska, M.; Massalska-Arodz, M.; Moscicki, J.K.; Jaich, A., Calorimetric study of NPOB, Mol. Cryst. Liq. Cryst., 1982, 80, 157-164. [all data] Bamezai, R.K.; Godlewska, M.; Massalska-arodz, M.; Sciesinski, J.; Witko, W., The adiabatic calorimetry study of the polymorphism of solid 4,4-di-n-butyloxyazoxybenzene, Phase Transitions, 1990, 27(2-3), 113-119. [all data] Mayer, J.; Witko, W.; Massalska-Arodz, M.; Williams, G.; Dabrowski, R., Polymorphism of right handed (S) 4-(2-Methylbutyl) 4´-Cyanobiphenyl, Phase Transitions, 1999, 69, 2, 199-213, https://doi.org/10.1080/01411599908208019 . [all data] Sciesinski, J.; Sciesinska, E.; Massalska, E.; Massalska-Arodz, M.; Wasiutynski, T.; Zielinski, P.M.; Witko, W., Polymorphism of righthanded octyloxycyanobiphenyl, IEEE Trans. Dielect. Electr. Insul., 2001, 8, 3, 522-526, https://doi.org/10.1109/94.933377 . [all data] Massalska-Arodz, M., Specific-heat ...
The outermost membrane of gram-negative bacteria is a lipopolysaccharide (LPS) rich bilayer assembly that acts as the first line of defense for bacterial cells in adverse physical and chemical environments. Besides the LPS, the outer membrane has radially extending O-antigen polysaccharide chains and β-barrel membrane proteins that make the bacterial membrane physiologically unique compared to the phospholipid cell membranes. To study the molecular complexity and dynamics of the LPS rich membrane, we have developed coarse grained parameter set for the outer membrane compatible with the Martini force field. The coarse grained model was benchmarked against available experimental and atomistic simulations data for properties such as membrane thickness, density profiles of the residues, area per lipid, gel to liquid-crystalline phase transition temperatures, order parameters, and radial distribution functions. More than 17 membrane compositions were studied with a combined simulation time of over 100
In accordance with column 2 of REACH Annex VII, the boiling point study does not need to be conducted as the substance decompose before boiling. A study similar to OECD 102 and EU Method A.2 was performed to determine the melting point of the test item using differential scanning calorimetry (DSC). The analysis was carried out in the DSC 1 STAR SYSTEM by Mettler Toledo. A SWISSI M20 crucible was used for the determination. The measuring range was between 25 °C to 300 °C at a heating rate of 2.0 °C/min. The analysis was performed as a duplicate determination. The decomposition of the test item releases an average energy of 818.5 J/g. The onset temperature of melting is an average 72.5 ° C. The decomposition temperature is at an average of 80.8 °C. As the test item decomposes right after melting, no boiling point could be determined. therefore, no test on boiling point is needed. ...
A chemical registry was created from a literature review and included characteristics relevant to XL such as molecular weight, carcinogenicity/mutagenicity, toxicity, hydrophobicity, and commercial availability. From this registry, compounds were then selected for efficacy screening using an ex vivo rabbit corneal cross-linking simulation set up. XL solution was administered via a corneal reservoir for 30 min in 0.1M NaHCO3 at either pH 7.4 or 8.5. The epithelium was left intact and 0.5% proparacaine was applied prior to XL. The control contralateral eye was treated identically with vehicle. Effectiveness of XL was based on shifts in thermal denaturation temperature (Tm) as measured by differential scanning calorimetry (Perkin-Elmer DSC 6000). Favorable DSC results were validated using biomechanical inflation tests with digital image correlation (DIC) as previously described by Myers et al.. ...
1B5U: CONTRIBUTION OF HYDROGEN BONDS TO THE CONFORMATIONAL STABILITY OF HUMAN LYSOZYME: CALORIMETRY AND X-RAY ANALYSIS OF SIX SER-|ALA MUTANT
The CMS hadronic calorimeter (HCAL) employs a plastic-scintillator-based endcap detector. The CMS HCAL Phase 1 upgrade involves installing silicon photomultipliers (SiPM) to measure light from scintillators in the detector. The SiPM signals are digitized by custom readout cards, called QIE cards, using the charge integration and encoder version 11 (QIE11) chip. The QIE cards for the HCAL endcap (HE) were tested and calibrated at FNAL. Then at CERN the QIE cards completed high radiation tests in the CHARM facility and muon/pion energy measurements in testbeam. Finally, the HE readout electronics were installed in CMS in 2018. The HCAL endcaps were calibrated using two Co-60 radiation sources. During physics data-taking in 2018, the HCAL online software (HCOS) configures and monitors the readout electronics to ensure data quality. This talk will summarize the testing, installation and commissioning of the HE Phase 1 upgrade readout system ...
LISA may be able to detect the gravitational waves from a first order phase transition at the electroweak scale. We present results from a large campaign of simulations studying a model of such phase transitions, and determine the shape of the power spectrum with unparalleled accuracy. We make concrete predictions of the detectability of sound waves from such a scenario, and note that an accurate measurement could place constraints on the underlying phase transition parameters.. ...
Journal of Shahid Sadoughi University of Medical Sciences ماهنامه علمی پژوهشی دانشگاه علوم پزشکی و خدمات بهداشتی درمانی شهید صدوقی یزد
Extramarks provides online study material for ICSE class 10 Calorimetry chapter. Practice physics icse board sample papers to score good marks in exams.
Abstract: We find an unexpected tetragonal-to-monoclinic-to-rhombohedral-to-cubic phase transition sequence induced by pressure, and a morphotropic phase boundary in a pure compound using first-principles calculations. Huge dielectric and piezoelectric coupling constants occur in the transition regions, comparable to those observed in the new complex single-crystal solid-solution piezoelectrics such as Pb(Mg$_{1/3}$Nb$_{2/3}$)O$_{3}$-PbTiO$_{3}$, which are expected to revolutionize electromechanical applications. Our results show that morphotropic phase boundaries and giant piezoelectric effects do not require intrinsic disorder, and open the possibility of studying this effect in simple systems ...
1B5X: Contribution of hydrogen bonds to the conformational stability of human lysozyme: calorimetry and X-ray analysis of six Ser Ala mutants.
Brief Summary Report of MHE Project Phenomenology and Controllability of New Exothermic Reaction between Metal and Hydrogen (Quote) https://www.researchgate.net/p…etween_Metal_and_Hydrogen
A new homologous series (ten compounds) of 2-hydroxy azo compounds SRn (where n:1-10) were synthesized. Their structures were elucidated using spectroscopic techniques such as IR (Infrared), 1H-NMR as well as elemental analysis. Mesomorphic properties and phase transitions were studied using polarized hot stage optical microscopy and differential scanning calorimetry (DSC), and are discussed as a function of the number of carbon atoms in the thioalkyl chain. It has been found that all compounds in the series are pure nematogens.
Molecular download on the in EducationWhy trade? untenable download on the nature of isotherms at first order phase transitions for classical is valid development? black or Black download on the nature of isotherms at first order phase transitions for?
Characterizing the interactions and stability of biomolecules. Microcalorimetry is used to study reactions involving biomolecules, including interactions
Characterizing the interactions and stability of biomolecules. Microcalorimetry is used to study reactions involving biomolecules, including interactions
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References [https://www.hamamatsu.com/eu/en/product/optical-sensors/photodiodes/si-photodiodes/index.html Hamamatsu Si photodiode datasheets ...
The invention relates to liquid-crystalline compounds of the formula I ##STR1##in which R.sup.1, R.sup.2, A.sup.1, A.sup.2, A.sup.3, A.sup.4, Z.sup.1, Z.sup.2, a, b and c are as defined in claim 1, and to liquid-crystalline media comprising at least compound of the formula I and to electro-optical displays containing a liquid-crystalline medium of this type.
If you have a question about this talk, please contact Norros I... Abstract not available. This talk is part of the Probability series.. ...
Glycin immersed in LN2 formed an amorphous product. Upon heating to -65 °C an unidentified crystalline phase of glycin was observed, which transformed at ≈ 55 °C to 2-glycin ...
The thermal phase transition behavior of maize starch in water:ionic liquid (IL) mixtures was investigated. With decreasing water:IL molar ratio to 10:1, the endothermic transition shifted to higher temperatures, and then to lower temperatures at 5:1 water:IL ratio. At 2:1 water:IL ratio, an exothermic transition occurred at a lower temperature than gelatinization temperature of starch in pure water. At the same water:IL ratios (35:1 to 5:1), the endothermic transition temperatures of starch increased with decreasing alkyl chain length of the cation, whereas an opposite trend was found for the exothermic transition at 2:1 water:IL ratio. Rheological, 1H NMR and FTIR analyses of water:IL mixtures showed that with decreasing water:IL ratio, the viscosity of water:IL mixture and the interactions between cation and anion increased, whereas the interactions between IL and water increased and then decreased. The endothermic transition of starch in water:IL mixtures of 35:1 to 5:1 was affected by the ...
The interactions of trimethoprim, sulphadiazine and sulphamethoxazole with natural (alpha-, beta-, gamma-) and amorphous (RAMEB) or crystalline (DIMEB) methylated beta-cyclodextrins were investigated both in aqueous solution (using phase-solubility analysis) and in the solid state (using DSC supported by X-ray analysis). In particular, DSC studies enabled determination of the relative degree of crystallinity of each drug in its physical and ground mixtures with the different cyclodextrins on the basis of the variation of its heat of fusion in comparison with that of the pure drug. In all cases, the host cavity size was a prevalent factor for the inclusion complexation in liquid state. On the contrary, it had a negligible effect on solid-state interactions in terms of drug amorphization. DIMEB and RAMEB exhibited similar performances in aqueous solution, showing that the presence of methyl-groups improved the complexing and solubilizing properties of beta-cyclodextrin. However, DSC studies ...
Breath cancer analysis. Thermographic footage of a man breathing towards a dogs nose as part of a test for cancer. A thermogram shows variation in temperature on the surface of an object, measured by the long-wave infrared radiation it emits. The temperature scale is colour-coded from black (cold) through dark blue, light blue, green and yellow to red and white (hottest). This thermogram footage shows that exhaled air is warm, but cools quickly. Dogs have an extremely sensitive sense of smell, and can be trained to detect different types of chemicals, including those produced in the breath in some forms of cancer. - Stock Video Clip K004/5646
Abstract: Loops are one of the fundamental structures that trace the geometry of the magnetic field in the solar atmosphere. Their evolution and dynamics provide a crucial proxy for studying how the magnetized structures are formed and heated in the solar atmosphere. Here, we report on spectroscopic observations of a set of transition region loops taken by the Interface Region Imaging Spectrograph (IRIS) at Si IV 1394 Å with a sit-and-stare mode. The loops are corresponding to the flux emergence at its very late phase when the emerged magentic features in the photosphere have fully developed. We find the transition region loops are still expanding and moving upward with a velocity of a few kilometers per second ($\lesssim$10 km/s) at this stage. The expansion of the loops leads to interactions between themselves and the ambient field, which can drive magnetic reconnection evidenced by multiple intense brightenings, including transition region explosive events and IRIS bombs in the footpoint ...
Dilauroylglycerol arginine conjugates constitute a novel class of specific biocompatible surfactants, which can be considered analogues of partial glycerides and phospholipids. During their preparation, spontaneous intramolecular acyl-migration reactions are observed and both possible regioisomers are obtained: 1,2-dilauroyl-rac-glycero-3-(Nα-acetyl-l-arginine) (1212RAc) and 1,3-dilauroylglycero-2-(Nα-acetyl-l-arginine) (12RAc12). To study the influence of the presence of both regioisomers on the physicochemical properties, the phase behavior in the dry state of pure 1,2-dilauroyl-rac-glycero-3-(Nα-acetyl-l-arginine) and two mixtures of both regioisomers were studied by differential scanning calorimetry and small-angle X-ray diffraction complemented by polarized light microscopy. The experiments were performed for a sequence of heating, cooling and reheating scans. The results have shown that all samples investigated display thermotropic liquid crystallinity. The transition temperatures have ...
0035]FIGS. 4-6 illustrate specific examples of differential scanning calorimetry (DSC) measurements of release agents at viscosities of approximately 8 mPa*s, 40 mPa*s and 77 mPa*s. More specifically, FIG. 4 illustrates a comparative release agent, wherein the release agent has a viscosity of 8 mPa*s. As can be seen from the DSC curve, the peak endothermic melting temperature or Tmp of the release agent is approximately 85° C., i.e., 85° C.+/-1° C., and the melting range of the release agent (Tmr) is in the range of 47° C.+/-1° C. to 105° C.+/-1° C. FIG. 5 illustrates a release agent contemplated herein, wherein the release agent exhibits a viscosity of approximately 40 mPa*s. As can be seen from the DSC curve, the peak endothermic melting temperature or Tmp of the release agent is approximately 84° C., i.e., 84° C.+/-1° C., and the melting range of the release agent (Tmr) is in the range of 43° C.+/-1° C. to 104° C.+/-1° C. FIG. 6 illustrates another release agent contemplated ...
Syndiotactic polystyrene pellets were processed into powder form using mechanical (ball milling, rotor milling) and physicochemical (spray drying) techniques with the intention of using it as feed material for selective laser sintering. New materials are an important component in broadening the application window for selective laser sintering but must meet strict requirements to be used. Particles obtained were characterized in size and shape using SEM imaging, analyzed by software, and compared to the product obtained by conventional ball milling. Rotor milling and spray drying proved capable of making spherical powders, yet only rotor milling achieved particles with a mean diameter within the desired range of 45-97 µm. Subsequently, the obtained powders were examined for the effect each processing technique imparts on the intrinsic properties of the material. Differential scanning calorimetry analysis revealed amorphization for all methods and a reduction in crystallinity after processing, however,
The effect of oxygen content in zirconium on the structure and mechanical properties of the Cu46Zr42Al7Y5 alloy, in the form of melt-spun ribbons and suction-cast rods, was investigated. Two types of Zr, rod and crystal bar of different nominal purities and oxygen contents, were used to synthesize the alloy by arc melting. Rapidly solidified ribbons were produced by melt spinning and their amorphous structures were confirmed by X-ray diffractometry (XRD) and differential scanning calorimetry (DSC). Bulk samples in the form of rods were cast using a special water-cooled suction casting unit attached to the arc melting system. XRD and DSC studies proved the amorphous structure of the bulk alloy synthesized from low-oxygen Zr and partial crystallization of the same alloy for high-oxygen Zr. In both bulk samples, uniformly distributed crystalline particles were identified as yttrium oxides. Higher mean compressive strength of amorphous alloy was observed. The hardness of amorphous phase was close to ...
We therefore used propolis as a lipid material to prepare solid lipid nanoparticles (SLNs); SLNs are proposed bioactive medications for topical intranasal therapy. Suitable formulation parameters were studied and the SLNs obtained by the high shear homogenization method were characterized; a selected formulation was viscosized to increase the residence time. Dimensional, morphological, and solid-state characterizations of the formulated SLNs were performed. In vitro and ex vivo permeation tests of diclofenac sodium, the model drug, and polyphenols were carried out. The propolis amount and surfactant concentration represent the key parameters that affect nanoparticle properties in terms of size, drug and polyphenol content, and physical stability. Size dispersions of about 600nm and 0.4 PI were obtained, which do not change by increasing the viscosity. Drug is encapsulated in SLNs, as demonstrated by FTIR and DSC analyses. ...
TY - JOUR. T1 - Ferroelastic domain structures of the low-temperature phase transition in TlH2PO4. AU - Kim, Kum Bae. AU - Lee, Kwang Sei. AU - Lee, Cheol Eui. PY - 1998/6. Y1 - 1998/6. N2 - The low-temperature II-III phase transition of TlH2PO4 (ferroelastic in phase II) at 230 K (Tc2) was studied by a polarizing microscope between 300 and 80 K. Despite the II-III phase transition at Tc2, the two kinds of ferroelastic domain structures with the (100) and/or (001) and (201) domain boundaries were still observed below Tc2 and were nearly temperature-independent. No new domain structures corresponding to antiferroelectric or ferrielectric orientation states were observed in phase III. The possible intermediate structural phase transition near 130 K suggested by vibrational spectroscopic study [B. Pasquier et al.: Chem. Phys. 171 (1993) 203] was not detected. The transition at Tc2 without optically detectable new domains indicates that the monoclinic crystal system of the phase II persists in phase ...
I have been getting annual thermograms instead of doing mammograms. During my last visit, the consultant noticed an area between my shoulder blades was highlighted green and she suggested that it may have something to do with gallbladder congestion. She referred me to the Miracle Gallbladder and Liver Cleanse book and protocall by Andreas Moritz. I read the book and did the flush 4 months in a row and seemed to have textbook results which consisted of small pea green "stones" exiting my body. There is a lot of praise for this protocall, but there seems to be an equal amount of skeptcsism about whether or not these are actually gall and liver stones or if they are a by product of the olive oil that is ingested the night before. I was hoping to get your opinions on this cleanse before I go forward with another round. Its not exactly how I want to spend a weekend, but I will continue if it is worth it. Thank You so much! Johnna T. ...
scales or at atomic scales, but virtually no technique offers the ability to monitor and map bias-induced phase transitions at nanometer lengths. The detection of phase transitions at these length scales is crucial for understanding the function of a variety of materials used in energy transduction, harvesting, and piezoelectric actuation. Here, a non-destructive technique is demonstrated using an atomic force microscope tip, which is used to confine an electric field in a small (nanometers) volume of material. By using a special AC waveform applied to the tip, it is possible to listen to the changes in the elastic properties of the material by monitoring the resonant frequency of the tip-sample contact. The technique is applied to a material used in ultrasound transducers and energy harvesting devices to detect and map a voltage-induced phase transition across the surface, and is compared to thermodynamic modeling, providing fresh insight into how these materials function at the relevant ...
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Elkordy, Amal, Forbes, Robert T and Barry, Brian W (2008) Study of protein conformational stability and integrity using calorimetry and FT-Raman spectroscopy correlated with enzymatic activity. European Journal of Pharmaceutical Sciences, 33 (2). pp. 177-190. ISSN 0928-0987 ...
AbeBooks.com: Quantitative X-Ray Diffractometry (9781461395379) by Lev S. Zevin; Giora Kimmel and a great selection of similar New, Used and Collectible Books available now at great prices.
Thermal analysis and calorimetry for carbon neutral capture in liquid , CO2 capture in solid media, Sequestration of CO2 hydrates, in minerals and saline solutions, and chemical looping combustion
We investigate the swelling and shrinking of L-beta lamellar gel phases composed of surfactant and fatty alcohol after contact with aqueous poly(ethyleneglycol) solutions. The height change Delta h(t) is diffusionlike with a swelling coefficient S: Delta h=S root t. On increasing polymer concentration, we observe sequentially slower swelling, absence of swelling, and finally shrinking of the lamellar phase. This behavior is summarized in a nonequilibrium diagram and the composition dependence of S quantitatively described by a generic model. We find a diffusion coefficient, the only free parameter, consistent with previous measurements ...
Reaction calorimeters uncover potential safety issues and provide process information under using real time heat flow or heat flux calorimetry.
A structural and Mössbauer study of Y3Fe5O12 nanoparticles prepared with high energy ball milling and subsequent sintering. Widatallah, H. M.; Johnson, C.; Al-Harthi, S. H.; Gismelseed, A. M.; Al-Rawas, A. D.; Stewart, S. J.; Elzain, M. E.; Al-Omari, I. A.; Yousif, A. A. // Hyperfine Interactions;2008, Vol. 183 Issue 1-3, p87 The influence of ball milling and subsequent sintering of a 3:5 molar mixture of Y2O3 and α-Fe2O3 on the formation of nanocrystalline Y3Fe5O12 (YIG) particles is studied. Pre-milling the mixture for 100 h lowers the onset temperature at which the material forms to 900°C which is 200°C... ...
K.Baumgartner, S. Oelmeier, J. Hubbuch, The influence of mixed salts on the capacity of HIC adsorbers and a correlation to the surface tension and the aggregation onset temperature, 34th International symposium on the separation of proteins, peptides and polynucleotides (ISPPP), Würzburg, Germany, 05. November 2014.. ...
While this new bra might sound like the next best thing since sliced bread, critics argue that the thermal technology may be premature. Hypothetically, its conceivable that malignant processes would have a temperature gradient compared to non-malignant tissues, says Dr. Therese Bevers, medical director of the cancer prevention center at the University of Texas M.D. Anderson Cancer Center. But that gradient may not be very large.". Medical experts say that thermograms are already being used by the industry to detect abnormal cells, but unfortunately the "hot" and "cold" spots that are supposed to indicate cancerous and non-malignant tissue, respectively, are not always accurate. We see some thermograms come back as abnormal, and we do all kinds of imaging with mammogram, ultrasound and MRI and we follow the women and nothing develops, says Bevers. And we have women with breast cancers that are not seen on the thermograms.. So, can First Warnings new sport bra really predict cancer? It is ...
In order to facilitate the study of reactive-compositional porous media processes we develop a virtual kinetic cell (single-cell model) as well as a virtual combustion tube (one-dimensional model). Both models are fully compositional based on an equation of state. We employ the models to study phase behavior sensitivity for in situ combustion, a thermal oil recovery process. For the one-dimensional model we first study the sensitivity to numerical discretization errors and provide grid density guidelines for proper resolution of in situ combustion behavior. A critical condition for success of in situ combustion processes is the formation and sustained propagation of a high-temperature combustion front. Using the models developed, we study the impact of phase behavior on ignition/extinction dynamics as a function of the operating conditions. We show that when operating close to ignition/extinction branches, a change of phase behavior model will shift the system from a state of ignition to a state ...
We discuss an open driven-dissipative many-body system, in which the competition of unitary Hamiltonian and dissipative Liouvillian dynamics leads to a nonequilibrium phase transition. It shares features of a quantum phase transition in that it is interaction driven, and of a classical phase transition, in that the ordered phase is continuously connected to a thermal state. We characterize the phase diagram and the critical behavior at the phase transition approached as a function of time. We find a novel fluctuation induced dynamical instability, which occurs at long wavelength as a consequence of a subtle dissipative renormalization effect on the speed of sound.. ...
The 144 site Elite Klone Machine is a Commercial Level propagation system. These systems are specifically designed for serious growers. Made of grey ABS plastic shell for less heat absorption from lights above and greater reflective properties to promote efficient growth. Has alpha/numeric lid to categorize different plant species with ease as well as colored Klone collars to visually differentiate plant species using a color coded pattern determined by you. Larger fan to introduce more oxygen to the grow chamber with even greater cooling effects. Optional humidity dome with integrated vents allow you to adjust the humidity level within the dome and provide more control.. Sold in Quantity of: 1. Warranty Offered: 1. ...
A system for treating vision disorders is disclosed. The system includes a heating device able to heat predetermined areas of the corneal tissue of an eye. The energy for heating is typically generated in the form of laser light or infrared that cause the tissue at that predetermined area to heat and shrink. The shrinkage shifts a plug or portion of the cornea with respect to the remainder of the eye to change the shape of the corneal surface and correct the problematic refractive error. A heat absorption modifier is used to avoid damage to the epithelial layer as energy is passed therethrough.
Abstract: Very recently, the discovery of a marginal, or practically perfect, phase transition (MPT or PPPT) at finite temperature in the 2-leg ladder Ising model with trimer rungs was reported [1]. The MPT or PPPT stems from a new mathematical structure that has not appeared before in phase-transition problems. This opens the door to simulations and utilizations of the spontaneous phase-transition phenomena in one-dimensional systems, despite the proof that phase transitions do not exist in the one-dimensional Ising models with short-range interactions back to year 1924 [2]. Naturally, the urgent fundamental and practical question is how we, now guided by the new light on phase transitions, can find the next cases of MPT or PPPT in one-dimensional systems. Here, I present a generalization of the original idea to a new parents-children Ising model with ice-cream-cone rungs, and exactly prove that the model possesses the same mathematical structure and thus MPT or PPPT. Yet, the ice-cream-cone ...
The synthesis and thermotropic properties of four homologous series of salicylaldimine-based dimer liquid crystals are reported. Two 4-(4-alkoxy-2-hydroxybenzylideneamino) benzoyloxy groups are connected to a central part consisting of a 1,3-phenylene, 1,5-pentylene, 2,2-dimethyl- 1,5-pentylene or 3,3-dimethyl-1,5-pentylene unit. The terminal alkoxy chains have been varied from 4 to 16 carbon atoms in length. All the compounds exhibit liquid crystalline phases whose behaviour depends on the nature of the central part and the length of the alkoxy terminal chains. All compounds of the series with the central phenyl part exhibit enantiotropic B-phases, and the sequence B-6 - B-1 - B-2 on increasing terminal chain length was observed. Replacement of the phenyl group with a pentyl central group partly suppresses the formation of B-phases. The longer homologues of this series show the B1 phase, while the shorter exhibit an intercalated SmCc mesophase. The introduction of methyl substituents to the ...
The paper frankly discusses some of the limits of using enthalpy arrays. For example, since the fragment should be present at a higher concentration than enzyme, very tight binders would require unfeasibly low enzyme concentrations. This limits the practical range of the technique to inhibitors with KIs ranging from ~500 nM to 2 mM. Also, as Morgen G observed in a comment to the last post, this is more of a biochemical assay (monitoring the heat of an enzymatic reaction) rather than what most people think of when you say the word calorimetry (monitoring the heat of binding, as in the case of isothermal titration calorimetry). Still, enthalpy arrays seem pretty cool; hopefully folks will warm to them ...
This volume explores the creation, study, and processing of new liquid-crystalline polymers. It covers not only the chemistry of liquid-crystalline polymers, but also the physics and engineering aspects of these materials. A wide range of topics is covered, including syntheses of main-chain and side-chain LCPs, structural characterization of LP, rheology and processing, and applications such a electro-optics and self-reinforcing blends.
Fraden et al. and Teramoto et al. have studied the entropy driven phase transition of monodisperse suspensions of purely repulsive rods from an isotropic to an aligned nematic phase experimentally. [1-2] The phase transition has also been studied theoretically and computationally. [3-5] For Fraden et al. the motivation to study hard particle binary mixtures of multiple aspect ratios stems from the desire to ultimately understand the impact of polydispersity on the phase separation of concentrated suspensions of rodlike macromolecules. F-actin, microtubules, and DNA are all examples of biological rodlike particles in which length and diameter polydispersity are common. Theoretical studies of binary hard-rod mixtures predict that in addition to isotropicnematic (I-N) coexistence, isotropic-nematic-nematic (I-N-N), isotropic-isotropic (I-I), and nematic-nematic (N-N) coexistence are possible when the length or diameter ratios of the particles are large enough [6 -12]. Fraden et al. have presented ...
Sharp phase boundaries Small changes in climate can show big effects - i.e. number of events. Climate Phase change and amplification Frost and salt crystallisation Phase transitions at precise thermo-hygrometric conditions
In this article, three formulations of two phase compositional Darcy flows taking into account phase transitions are compared. The first formulation is the so called natural variable formulation commonly used in reservoir simulation, the second has been introduced in [14] and uses the phase pressures, saturations and component fugacities as main unknowns, and the third is an extension to general compositional two phase flows of the pressure pressure formulation introduced in [2] in the case of two compo-nents. The three formulations are shown to lead to equivalent definitions of the phase transitions for our gas liquid thermodynamical model. Then, they are compared numerically in terms of solution and convergence of the Newton type non linear solver on several 1D and 3D test cases including gas appearance and liquid disappearance. The 3D discretization is based on the Vertex Approximate Gradient (VAG) scheme [10] and takes into account discontinuous capillary pressures.
A mixture of at least two aqueous dispersions of non-ionic lipid spherules encapsulating an aqueous phase containing an active substance. The active substance encapsulated in the spherules of one of the dispersions is different from the active substance encapsulated in the spherules of another of the dispersions.
Microcalorimetry enables detailed investigation of the interactions between and thermodynamics of molecules/biomolecules and is particularly widely used
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Differential scanning calorimeter[edit]. Main article: Differential scanning calorimetry. In a differential scanning ... Differential scanning calorimetry is a workhorse technique in many fields, particularly in polymer characterization. ... A modulated temperature differential scanning calorimeter (MTDSC) is a type of DSC in which a small oscillation is imposed upon ... Differential scanning calorimeters, isothermal micro calorimeters, titration calorimeters and accelerated rate calorimeters are ...
Differential scanning calorimetry, viscosity measurements, light scattering). Uses[edit]. Because of their amphiphilic ...
To measure the heat flow differential scanning calorimetry can be used.[9] ...
a b ISO 11357-2: Plastics - Differential scanning calorimetry - Part 2: Determination of glass transition temperature (1999). ... The most frequently used definition of Tg uses the energy release on heating in differential scanning calorimetry (DSC, see ... Measurement of Tg (the temperature at the point A) by differential scanning calorimetry ... phonons in condensed matter are directly responsible for the thermal conductivity that levels out temperature differentials ...
Differential scanning calorimetry". Retrieved 17 April 2017. Chupka, É. I.; Rykova, T. M. (1983). "Electrical properties of ... as determined as inflection point of the heat capacity-temperature curve recorded by differential scanning calorimetry (DSC). ... The phosphitylated sample is then scanned using liquide state 31P-NMR spectroscopy and the hydroxyl groups are quantified by ...
Thermogravimetry Differential thermal analysis Differential scanning calorimetry Danish, Muhammad; Ahmad, Nazir; Zahara, Nayab ...
... differential scanning calorimetry, thermogravimetric analysis; Electrophoresis; Field flow fractionation; X-ray diffraction; ...
Differential scanning calorimetry is used to characterize the thermal properties of polymers, such as the glass transition ... represented as traces from differential scanning calorimetry. As the temperature increases, both amorphous and semicrystalline ...
"Detection of coating waxes on apples by differential scanning calorimetry". European Food Research and Technology 212.5 (2000) ...
Differential Scanning Calorimetry (DSC) tests demonstrate the apparent source of discrepancy. On heating, solid Galinstan will ... is a scan of a eutectic specimen showing the melting point at +10°C and the freezing point is -19°C. Several US patents have ...
Its existence has only recently been confirmed by differential scanning calorimetry. Okamoto H; Journal of Phase Equilibria, ...
"Differential Scanning Calorimetry Analysis of the Thermal Treatment of Ternary Mixtures of Ethylene Vinyl Acetate, Polyethylene ...
This technique uses differential scanning calorimetry (DSC) to detect the phase changes. The signal detection relies on ... of the melting can be done by sensing the transient heat flows during phase transitions using differential scanning calorimetry ... Scanning curves and loops have been used to show that cryoporometry melting curves are prone to pore-pore cooperative effects ... "Studies of freezing-melting hysteresis in cryoporometry scanning loop experiments using NMR diffusometry and relaxometry", Chem ...
I. Study of curing by differential scanning calorimetry and Fourier transform infrared". Journal of Polymer Science Part A: ...
... of the temperature and enthalpy of the solid-solid phase transition of caesium nitrate by differential scanning calorimetry". ...
Differential scanning calorimetry (DSC) is used to determine the thermal properties of polyanhydrides. Glass transition ...
"Quantitative Description of Temperature Induced Self-Aggregation Thermograms Determined by Differential Scanning Calorimetry". ... equation can be exploited for the extraction of aggregation numbers of self-assembled micelles from differential scanning ... "Enthalpy of micellisation of a diblock copoly(oxyethylene/oxypropylene) by isothermal titration calorimetry. Comparison with ...
Differential scanning calorimetry gives information on melting point together with its enthalpy of fusion. A basic melting ...
Differential scanning calorimetry (DSC) is another method industries use to examine properties of gelatinized starch. As water ...
Differential scanning calorimetry has shown that high temperature (69 °C) is required to unfold it. Phytic acid is the primary ...
Assays to detect adulteration with HFCS use differential scanning calorimetry and other advanced testing methods. In the ...
Differential scanning calorimetry (DSC) is an analytical technique used to examine thermodynamic properties of molecules. It ... differential scanning calorimetry (DSC), nuclear magnetic resonance which include 2HNMR and 31PNMR, thin layer chromatography ( ...
The most frequently used definition of Tg uses the energy release on heating in differential scanning calorimetry (DSC, see ... ISO 11357-2: Plastics - Differential scanning calorimetry - Part 2: Determination of glass transition temperature (1999). "The ... phonons in condensed matter are directly responsible for the thermal conductivity that levels out temperature differentials ...
Differential scanning calorimetry can be used to quantify enthalpy change due to molecular structural relaxation. The term " ... Let the homogeneous differential equation: m d 2 y d t 2 + γ d y d t + k y = 0 {\displaystyle m{\frac {d^{2}y}{dt^{2}}}+\gamma ...
The sf-TM experiments duplicate experiments that can be performed using differential scanning calorimetry (DSC). A limitation ... A second cooling scan followed by a third heating scan can be performed to check on the reliability of the prior scans. ... The second heating scan will differ from the first heating scan because of thermal relaxation during the first scan and the ... used to be consistent with modulated temperature differential scanning calorimetry (mt-DSC) and other situations when a ...
By differential scanning calorimetry (DSC), holo SOD1 unfolds by a two-state mechanism: from dimer to two unfolded monomers.[24 ...
Differential scanning calorimetry, or DSC, is a thermoanalytical technique in which the difference in the amount of heat ...
One of the major advantages of differential scanning calorimetry (DSC) is that it depends on heat measurements, which make ... Influence of transition rates and scan rate on kinetic simulations of differential scanning calorimetry profiles of reversible ... One of the major advantages of differential scanning calorimetry (DSC) is that it depends on heat measurements, which make ... Using Differential Scanning Calorimetry to Expedite the Development of Optimized Therapeutic Protein Formulations. ...
This is accomplished by means of differential scanning calorimetry (DSC). The technique makes use of the double melting point ... Determination of Degradation of Nylon 66 Using Differential Scanning Calorimetry. Published: 0 ... predictions, heat measurement, scanning, nylon 66, degradation, melting points, polyamide resins, brittleness, crystallization ... predictions, heat measurement, scanning, nylon 66, degradation, melting points, polyamide resins, brittleness, crystallization ...
Differential scanning calorimetry, or DSC, is a thermoanalytical technique in which the difference in the amount of heat ... Differential scanning calorimetry can be used to measure a number of characteristic properties of a sample. Using this ... Using differential scanning calorimetry to study the stability to oxidation of samples generally requires an airtight sample ... Freezing-point depression can be used as a purity analysis tool when analysed by differential scanning calorimetry. This is ...
Flash Differential Scanning Calorimetry revolutionizes rapid-scanning DSC. The Flash DSC 1 can analyze reorganization processes ... Temperature Scan DMA Measurements of Differently Vulcanized SBR Samples. Frequency Sweep DMA Measurements of Differently ... You are here: Home , Analytical Instruments , Thermal Analysis Excellence , Chip Calorimetry (Flash DSC) ... Safety analysis of a nitration reaction by DSC and reaction calorimetry. Safety is an important aspect in process development ...
Differential Scanning Calorimetry (DSC). Differential scanning calorimetry (DSC) is the most frequently used thermal analysis ... Differential Scanning Calorimetry (DSC). Glass transition temperature and crystallization determination by Differential ... Physics of Differential scanning calorimetry. Differences in heat flow arise when a sample absorbs or releases heat due to ... Differential scanning calorimetry (DSC) is the most frequently used thermal analysis tech-nique. DSC measures enthalpy changes ...
A method and apparatus for simultaneous differential scanning calorimetry and microdielectrometry is disclosed. The apparatus ... Differential scanning calorimeter. WO1998020314A3 *. Oct 31, 1997. Jul 2, 1998. Ta Instr Inc. Differential scanning calorimeter ... Differential Scanning Calorimetry (DSC) provides quantitative measurements of the instantaneous heat capacities and thermal ... 2 discloses a cross-sectional schematic view of a sample cell for simultaneous differential scanning calorimetry and ...
type.9 9.). Test Methods 11.1 Melting Characteristics by Thermal Analysis-Use differential scanning calorimetry (DSC) as ...
Learn about the principles of Differential Scanning Calorimetry (DSC). Differential Scanning Calorimetry (DSC) is a technique ...
Differential scanning calorimetry of the effects of temperature and humidity on phenol-formaldehyde resin cure. Polymer. Vol. ... Differential scanning calorimetry of the effects of temperature and humidity on phenol-formaldehyde resin cure ... A differential scanning calorimeter was employed to characterize the degree of resin cure in this study. Resin-impregnated ...
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Nonisothermal crystallization kinetics of in situ nylon 6/graphene composites by differential scanning calorimetry. Authors. * ... The nonisothermal crystallization kinetics was investigated by differential scanning calorimetry for the nylon 6/graphene ... Isothermal crystallization kinetics of in situ Nylon 6/graphene composites by differential scanning calorimetry, Polymer ... Journal of Thermal Analysis and Calorimetry, 2014, 118, 1, 197. CrossRef ...
... differential scanning calorimetry, differential thermal analysis, hydrocarbons, oxidation, oxidation induction time (OIT), ... oxidation onset temperature (OOT), oxidative stability, pressure differential scanning calorimetry, ... e1 Standard Test Methods for Oxidation Onset Temperature of Hydrocarbons by Differential Scanning Calorimetry , ... of the oxidative properties of hydrocarbons by differential scanning calorimetry or pressure differential scanning calorimetry ...
Get Differential Scanning Calorimetry Supplies at Spectrum Chemical. SpectrumChemical.com carries a full line of fine chemicals ... Differential Scanning Calorimetry Supplies Differential Scanning Calorimetry Supplies. Spectrum offers laboratory grade ... Spectrum has the Differential Scanning Calorimetry Supplies solution for you. ... Differential Scanning Calorimetry Supplies from the industrys leading manufacturer Perkin Elmer. Whether you require a DSC ...
Using differential scanning calorimetry (DSC) and plate count (PC), growth of Escherichia coli was measured in four initial E. ... Growth measurement of Escherichia coli by differential scanning calorimetry. Villagómez Ibarra, José Roberto. 2014 ... Growth measurement of Escherichia coli by differential scanning calorimetry?, Esmeralda Rangel-Vargas, Carlos A. Gómez-Aldapa, ...
... differential scanning calorimetry, hydrocarbons, isothermal temperature, oxidation, oxidation induction time, oxidative ... e1 Standard Test Methods for Determining Oxidation Induction Time of Hydrocarbons by Differential Scanning Calorimetry , ... of the oxidative properties of hydrocarbons by differential scanning calorimetry or pressure differential scanning calorimetry ... Standard Test Methods for Determining Oxidation Induction Time of Hydrocarbons by Differential Scanning Calorimetry. Active ...
... differential scanning calorimetry, hazard potential, kinetics, thermal analysis, thermal hazard, thermal stability,, ... 16 Standard Test Method for Kinetic Parameters for Thermally Unstable Materials Using Differential Scanning Calorimetry and the ... E2890 Test Method for Kinetic Parameters for Thermally Unstable Materials by Differential Scanning Calorimetry Using the ... Standard Test Method for Kinetic Parameters for Thermally Unstable Materials Using Differential Scanning Calorimetry and the ...
It was therefore of interest to investigate the possible application of differential scanning calorimetry (DSC) as a fast and ... investigation to group disparate batches of licit and illicit diazepam tablets using differential scanning calorimetry ... investigation to group disparate batches of licit and illicit diazepam tablets using differential scanning calorimetry S. Bibi ...
Differential scanning calorimetry studies revealed strong relationships between onset and enthalpy values of all acorn tissues ... Effects of desiccation on temperate recalcitrant seeds: differential scanning calorimetry, gas chromatography, electron ... Effects of desiccation on temperate recalcitrant seeds: differential scanning calorimetry, gas chromatography, electron ...
Differential scanning calorimetry of blood plasma for clinical diagnosis and monitoring. Exp Mol Pathol. 2009;86:186-91.PubMed ... The differential scanning calorimetry (DSC) method has been employed to compare changes in DSC profiles of blood sera in the ... Differential scanning calorimetry was applied to evaluate the effect of WBC on the response of elite cross-country skiers to ... Differential scanning calorimetry (DSC) was applied to compare changes in athletes blood serum during both sessions. Mean DSC ...
The electrochemical results were in close agreement with those deriving from a differentialscanning calorimetric study of the ...
Kinetics of Cold-Cap Reactions for Vitrification of Nuclear Waste Glass Based on Simultaneous Differential Scanning Calorimetry ... Kinetics of Cold-Cap Reactions for Vitrification of Nuclear Waste Glass Based on Simultaneous Differential Scanning Calorimetry ... the cold-cap reactions of a representative waste glass feed using both the simultaneous differential scanning calorimetry ...
Differential scanning calorimetry (DSC) unfolding trace of AxeA. The protein (0.6 mg ml−1) was heated in 50 mM sodium phosphate ... f5: Differential scanning calorimetry (DSC) unfolding trace of AxeA. The protein (0.6 mg ml−1) was heated in 50 mM sodium ... f5: Differential scanning calorimetry (DSC) unfolding trace of AxeA. The protein (0.6 mg ml−1) was heated in 50 mM sodium ... Mentions: The thermal stability of AxeA was further investigated by differential scanning calorimetry (DSC). The observed ...
The application of Differential Scanning Calorimetry (DSC) has been proven useful in characterizing bituminous binders, ... Differential Scanning Calorimetry applied to bitumen: Results of the RILEM NBM TG1 Round Robin test.. The application of ... The application of Differential Scanning Calorimetry (DSC) has been proven useful in characterizing bituminous binders, ... Differential Scanning Calorimetry (DSC) has been proven useful in characterizing bituminous binders, distillates and crude oils ...
  • Compared with those parameters determined by titration calorimetry, the results highlight the potentiality of DSC to estimate binding parameters in multiligand binding proteins. (meta.org)
  • In this sense, the application of the theory of macromolecular unfolding linked to ligand binding to differential scanning calorimetry (DSC) has proved to be a useful tool to simultaneously characterize the energetics of unfolding and binding. (meta.org)
  • Calorimetry is the science or act of measuring changes in state variables of a body for the purpose of deriving the heat transfer associated with changes of its state due, for example, to chemical reactions, physical changes, or phase transitions under specified constraints. (wikipedia.org)
  • The surface of the specimen to be examined is scanned with an electron beam, and the reflected (or back-scattered) beam of electrons is collected, then displayed at the same scanning rate on a cathode ray tube (similar to a TV screen). (fisk.edu)
  • Differential scanning calorimetry results have shown that MP196 prefers incorporation into bacterial cell membranes over erythrocyte membranes, as this cationic peptide prefers incorporating into membranes which have a higher negatively charged phospholipid ratio. (wikipedia.org)