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.Models, Molecular: Models used experimentally or theoretically to study molecular shape, electronic properties, or interactions; includes analogous molecules, computer-generated graphics, and mechanical structures.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)Molecular Conformation: The characteristic three-dimensional shape of a molecule.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.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.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).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.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).Crystallography, X-Ray: The study of crystal structure using X-RAY DIFFRACTION techniques. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)Base Sequence: The sequence of PURINES and PYRIMIDINES in nucleic acids and polynucleotides. It is also called nucleotide sequence.Crystallography: The branch of science that deals with the geometric description of crystals and their internal arrangement. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)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.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.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.Quantitative Structure-Activity Relationship: A quantitative prediction of the biological, ecotoxicological or pharmaceutical activity of a molecule. It is based upon structure and activity information gathered from a series of similar compounds.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.Binding Sites: The parts of a macromolecule that directly participate in its specific combination with another molecule.Genome Components: The parts of a GENOME sequence that are involved with the different functions or properties of genomes as a whole as opposed to those of individual GENES.Chemistry, Physical: The study of CHEMICAL PHENOMENA and processes in terms of the underlying PHYSICAL PHENOMENA and processes.Chemistry: A basic science concerned with the composition, structure, and properties of matter; and the reactions that occur between substances and the associated energy exchange.Crystallization: The formation of crystalline substances from solutions or melts. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)Molecular Weight: The sum of the weight of all the atoms in a molecule.Physicochemical Phenomena: The physical phenomena describing the structure and properties of atoms and molecules, and their reaction and interaction processes.Spectrum Analysis, Raman: Analysis of the intensity of Raman scattering of monochromatic light as a function of frequency of the scattered light.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.Microscopy, Scanning Tunneling: A type of scanning probe microscopy in which a very sharp conducting needle is swept just a few angstroms above the surface of a sample. The tiny tunneling current that flows between the sample and the needle tip is measured, and from this are produced three-dimensional topographs. Due to the poor electron conductivity of most biological samples, thin metal coatings are deposited on the sample.Chemical Phenomena: The composition, conformation, and properties of atoms and molecules, and their reaction and interaction processes.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)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)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.Scenedesmus: A genus of GREEN ALGAE in the family Scenedesmaceae. It forms colonies of usually four or eight cylindrical cells that are widely distributed in freshwater and SOIL.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.Macromolecular Substances: Compounds and molecular complexes that consist of very large numbers of atoms and are generally over 500 kDa in size. In biological systems macromolecular substances usually can be visualized using ELECTRON MICROSCOPY and are distinguished from ORGANELLES by the lack of a membrane structure.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).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.Nucleic Acid Conformation: The spatial arrangement of the atoms of a nucleic acid or polynucleotide that results in its characteristic 3-dimensional shape.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)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.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.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.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.Electron Microscope Tomography: A tomographic technique for obtaining 3-dimensional images with transmission electron microscopy.Stereoisomerism: The phenomenon whereby compounds whose molecules have the same number and kind of atoms and the same atomic arrangement, but differ in their spatial relationships. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 5th ed)Surface Properties: Characteristics or attributes of the outer boundaries of objects, including molecules.Models, Structural: A representation, generally small in scale, to show the structure, construction, or appearance of something. (From Random House Unabridged Dictionary, 2d ed)Synchrotrons: Devices for accelerating protons or electrons in closed orbits where the accelerating voltage and magnetic field strength varies (the accelerating voltage is held constant for electrons) in order to keep the orbit radius constant.Humic Substances: Organic matter in a state of advanced decay, after passing through the stages of COMPOST and PEAT and before becoming lignite (COAL). It is composed of a heterogenous mixture of compounds including phenolic radicals and acids that polymerize and are not easily separated nor analyzed. (E.A. Ghabbour & G. Davies, eds. Humic Substances, 2001).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.Microscopy, Atomic Force: A type of scanning probe microscopy in which a probe systematically rides across the surface of a sample being scanned in a raster pattern. The vertical position is recorded as a spring attached to the probe rises and falls in response to peaks and valleys on the surface. These deflections produce a topographic map of the sample.Spectrum Analysis: The measurement of the amplitude of the components of a complex waveform throughout the frequency range of the waveform. (McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)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)Electrophoresis, Polyacrylamide Gel: Electrophoresis in which a polyacrylamide gel is used as the diffusion medium.Computer Simulation: Computer-based representation of physical systems and phenomena such as chemical processes.Chromatium: A genus of gram-negative, ovoid to rod-shaped bacteria that is phototrophic. All species use ammonia as a nitrogen source. Some strains are found only in sulfide-containing freshwater habitats exposed to light while others may occur in marine, estuarine, and freshwater environments.Recombinant Proteins: Proteins prepared by recombinant DNA technology.Kinetics: The rate dynamics in chemical or physical systems.Sequence Homology, Nucleic Acid: The sequential correspondence of nucleotides in one nucleic acid molecule with those of another nucleic acid molecule. Sequence homology is an indication of the genetic relatedness of different organisms and gene function.Computer Graphics: The process of pictorial communication, between human and computers, in which the computer input and output have the form of charts, drawings, or other appropriate pictorial representation.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 Structure, Quaternary: The characteristic 3-dimensional shape and arrangement of multimeric proteins (aggregates of more than one polypeptide chain).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.Cryoelectron Microscopy: Electron microscopy involving rapid freezing of the samples. The imaging of frozen-hydrated molecules and organelles permits the best possible resolution closest to the living state, free of chemical fixatives or stains.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.Metmyoglobin: Myoglobin which is in the oxidized ferric or hemin form. The oxidation causes a change in color from red to brown.Freeze Etching: A replica technique in which cells are frozen to a very low temperature and cracked with a knife blade to expose the interior surfaces of the cells or cell membranes. The cracked cell surfaces are then freeze-dried to expose their constituents. The surfaces are now ready for shadowing to be viewed using an electron microscope. This method differs from freeze-fracturing in that no cryoprotectant is used and, thus, allows for the sublimation of water during the freeze-drying process to etch the surfaces.Bisbenzimidazole: A benzimidazole antifilarial agent; it is fluorescent when it binds to certain nucleotides in DNA, thus providing a tool for the study of DNA replication; it also interferes with mitosis.Pharmaceutical Preparations: Drugs intended for human or veterinary use, presented in their finished dosage form. Included here are materials used in the preparation and/or formulation of the finished dosage form.Species Specificity: The restriction of a characteristic behavior, anatomical structure or physical system, such as immune response; metabolic response, or gene or gene variant to the members of one species. It refers to that property which differentiates one species from another but it is also used for phylogenetic levels higher or lower than the species.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.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)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.Hydrogen: The first chemical element in the periodic table. It has the atomic symbol H, atomic number 1, and atomic weight [1.00784; 1.00811]. It exists, under normal conditions, as a colorless, odorless, tasteless, diatomic gas. Hydrogen ions are PROTONS. Besides the common H1 isotope, hydrogen exists as the stable isotope DEUTERIUM and the unstable, radioactive isotope TRITIUM.Restriction Mapping: Use of restriction endonucleases to analyze and generate a physical map of genomes, genes, or other segments of DNA.Amino Acids: Organic compounds that generally contain an amino (-NH2) and a carboxyl (-COOH) group. Twenty alpha-amino acids are the subunits which are polymerized to form proteins.Software: Sequential operating programs and data which instruct the functioning of a digital computer.Cell Membrane: The lipid- and protein-containing, selectively permeable membrane that surrounds the cytoplasm in prokaryotic and eukaryotic cells.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.Static Electricity: The accumulation of an electric charge on a objectModels, 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.Amyloid: A fibrous protein complex that consists of proteins folded into a specific cross beta-pleated sheet structure. This fibrillar structure has been found as an alternative folding pattern for a variety of functional proteins. Deposits of amyloid in the form of AMYLOID PLAQUES are associated with a variety of degenerative diseases. The amyloid structure has also been found in a number of functional proteins that are unrelated to disease.Algorithms: A procedure consisting of a sequence of algebraic formulas and/or logical steps to calculate or determine a given task.Lipid Bilayers: Layers of lipid molecules which are two molecules thick. Bilayer systems are frequently studied as models of biological membranes.Silk: A continuous protein fiber consisting primarily of FIBROINS. It is synthesized by a variety of INSECTS and ARACHNIDS.Electrons: Stable elementary particles having the smallest known negative charge, present in all elements; also called negatrons. Positively charged electrons are called positrons. The numbers, energies and arrangement of electrons around atomic nuclei determine the chemical identities of elements. Beams of electrons are called CATHODE RAYS.Heme: The color-furnishing portion of hemoglobin. It is found free in tissues and as the prosthetic group in many hemeproteins.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)X-Rays: Penetrating electromagnetic radiation emitted when the inner orbital electrons of an atom are excited and release radiant energy. X-ray wavelengths range from 1 pm to 10 nm. Hard X-rays are the higher energy, shorter wavelength X-rays. Soft x-rays or Grenz rays are less energetic and longer in wavelength. The short wavelength end of the X-ray spectrum overlaps the GAMMA RAYS wavelength range. The distinction between gamma rays and X-rays is based on their radiation source.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)Isomerism: The phenomenon whereby certain chemical compounds have structures that are different although the compounds possess the same elemental composition. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 5th ed)Fourier Analysis: Analysis based on the mathematical function first formulated by Jean-Baptiste-Joseph Fourier in 1807. The function, known as the Fourier transform, describes the sinusoidal pattern of any fluctuating pattern in the physical world in terms of its amplitude and its phase. It has broad applications in biomedicine, e.g., analysis of the x-ray crystallography data pivotal in identifying the double helical nature of DNA and in analysis of other molecules, including viruses, and the modified back-projection algorithm universally used in computerized tomography imaging, etc. (From Segen, The Dictionary of Modern Medicine, 1992)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.Blotting, Southern: A method (first developed by E.M. Southern) for detection of DNA that has been electrophoretically separated and immobilized by blotting on nitrocellulose or other type of paper or nylon membrane followed by hybridization with labeled NUCLEIC ACID PROBES.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)Bacterial Proteins: Proteins found in any species of bacterium.Plant Lectins: Protein or glycoprotein substances of plant origin that bind to sugar moieties in cell walls or membranes. Some carbohydrate-metabolizing proteins (ENZYMES) from PLANTS also bind to carbohydrates, however they are not considered lectins. Many plant lectins change the physiology of the membrane of BLOOD CELLS to cause agglutination, mitosis, or other biochemical changes. They may play a role in plant defense mechanisms.Mass Spectrometry: An analytical method used in determining the identity of a chemical based on its mass using mass analyzers/mass spectrometers.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)Phylogeny: The relationships of groups of organisms as reflected by their genetic makeup.Organometallic Compounds: A class of compounds of the type R-M, where a C atom is joined directly to any other element except H, C, N, O, F, Cl, Br, I, or At. (Grant & Hackh's Chemical Dictionary, 5th ed)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.Chromatography, High Pressure Liquid: Liquid chromatographic techniques which feature high inlet pressures, high sensitivity, and high speed.Substrate Specificity: A characteristic feature of enzyme activity in relation to the kind of substrate on which the enzyme or catalytic molecule reacts.Nanostructures: Materials which have structured components with at least one dimension in the range of 1 to 100 nanometers. These include NANOCOMPOSITES; NANOPARTICLES; NANOTUBES; and NANOWIRES.Databases, Factual: Extensive collections, reputedly complete, of facts and data garnered from material of a specialized subject area and made available for analysis and application. The collection can be automated by various contemporary methods for retrieval. The concept should be differentiated from DATABASES, BIBLIOGRAPHIC which is restricted to collections of bibliographic references.Peptide Fragments: Partial proteins formed by partial hydrolysis of complete proteins or generated through PROTEIN ENGINEERING techniques.Molecular Dynamics Simulation: A computer simulation developed to study the motion of molecules over a period of time.Odors: The volatile portions of substances perceptible by the sense of smell. (Grant & Hackh's Chemical Dictionary, 5th ed)Protein Multimerization: The assembly of the QUATERNARY PROTEIN STRUCTURE of multimeric proteins (MULTIPROTEIN COMPLEXES) from their composite PROTEIN SUBUNITS.Rabbits: The species Oryctolagus cuniculus, in the family Leporidae, order LAGOMORPHA. Rabbits are born in burrows, furless, and with eyes and ears closed. In contrast with HARES, rabbits have 22 chromosome pairs.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.Pepsin A: Formed from pig pepsinogen by cleavage of one peptide bond. The enzyme is a single polypeptide chain and is inhibited by methyl 2-diaazoacetamidohexanoate. It cleaves peptides preferentially at the carbonyl linkages of phenylalanine or leucine and acts as the principal digestive enzyme of gastric juice.Chromatography, Gel: Chromatography on non-ionic gels without regard to the mechanism of solute discrimination.Protons: Stable elementary particles having the smallest known positive charge, found in the nuclei of all elements. The proton mass is less than that of a neutron. A proton is the nucleus of the light hydrogen atom, i.e., the hydrogen ion.PolysaccharidesViscosity: The resistance that a gaseous or liquid system offers to flow when it is subjected to shear stress. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)Cell Line: Established cell cultures that have the potential to propagate indefinitely.Quantum Theory: The theory that the radiation and absorption of energy take place in definite quantities called quanta (E) which vary in size and are defined by the equation E=hv in which h is Planck's constant and v is the frequency of the radiation.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)1,2-Dipalmitoylphosphatidylcholine: Synthetic phospholipid used in liposomes and lipid bilayers to study biological membranes. It is also a major constituent of PULMONARY SURFACTANTS.Organic Chemicals: A broad class of substances containing carbon and its derivatives. Many of these chemicals will frequently contain hydrogen with or without oxygen, nitrogen, sulfur, phosphorus, and other elements. They exist in either carbon chain or carbon ring form.Oligodeoxyribonucleotides: A group of deoxyribonucleotides (up to 12) in which the phosphate residues of each deoxyribonucleotide act as bridges in forming diester linkages between the deoxyribose moieties.Plants: Multicellular, eukaryotic life forms of kingdom Plantae (sensu lato), comprising the VIRIDIPLANTAE; RHODOPHYTA; and GLAUCOPHYTA; all of which acquired chloroplasts by direct endosymbiosis of CYANOBACTERIA. They are characterized by a mainly photosynthetic mode of nutrition; essentially unlimited growth at localized regions of cell divisions (MERISTEMS); cellulose within cells providing rigidity; the absence of organs of locomotion; absence of nervous and sensory systems; and an alternation of haploid and diploid generations.Exons: The parts of a transcript of a split GENE remaining after the INTRONS are removed. They are spliced together to become a MESSENGER RNA or other functional RNA.Protein Folding: Processes involved in the formation of TERTIARY PROTEIN STRUCTURE.Glycoproteins: Conjugated protein-carbohydrate compounds including mucins, mucoid, and amyloid glycoproteins.Sequence Analysis, DNA: A multistage process that includes cloning, physical mapping, subcloning, determination of the DNA SEQUENCE, and information analysis.Catalysis: The facilitation of a chemical reaction by material (catalyst) that is not consumed by the reaction.Vibration: A continuing periodic change in displacement with respect to a fixed reference. (McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)Alcohols: Alkyl compounds containing a hydroxyl group. They are classified according to relation of the carbon atom: primary alcohols, R-CH2OH; secondary alcohols, R2-CHOH; tertiary alcohols, R3-COH. (From Grant & Hackh's Chemical Dictionary, 5th ed)Drug Design: The molecular designing of drugs for specific purposes (such as DNA-binding, enzyme inhibition, anti-cancer efficacy, etc.) based on knowledge of molecular properties such as activity of functional groups, molecular geometry, and electronic structure, and also on information cataloged on analogous molecules. Drug design is generally computer-assisted molecular modeling and does not include pharmacokinetics, dosage analysis, or drug administration analysis.Genes: A category of nucleic acid sequences that function as units of heredity and which code for the basic instructions for the development, reproduction, and maintenance of organisms.Plant Proteins: Proteins found in plants (flowers, herbs, shrubs, trees, etc.). The concept does not include proteins found in vegetables for which VEGETABLE PROTEINS is available.Gene Library: A large collection of DNA fragments cloned (CLONING, MOLECULAR) from a given organism, tissue, organ, or cell type. It may contain complete genomic sequences (GENOMIC LIBRARY) or complementary DNA sequences, the latter being formed from messenger RNA and lacking intron sequences.Biological Evolution: The process of cumulative change over successive generations through which organisms acquire their distinguishing morphological and physiological characteristics.Carbohydrate Conformation: The characteristic 3-dimensional shape of a carbohydrate.DNA Transposable Elements: Discrete segments of DNA which can excise and reintegrate to another site in the genome. Most are inactive, i.e., have not been found to exist outside the integrated state. DNA transposable elements include bacterial IS (insertion sequence) elements, Tn elements, the maize controlling elements Ac and Ds, Drosophila P, gypsy, and pogo elements, the human Tigger elements and the Tc and mariner elements which are found throughout the animal kingdom.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.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).Inhibitory Concentration 50: The concentration of a compound needed to reduce population growth of organisms, including eukaryotic cells, by 50% in vitro. Though often expressed to denote in vitro antibacterial activity, it is also used as a benchmark for cytotoxicity to eukaryotic cells in culture.Diffusion: The tendency of a gas or solute to pass from a point of higher pressure or concentration to a point of lower pressure or concentration and to distribute itself throughout the available space. Diffusion, especially FACILITATED DIFFUSION, is a major mechanism of BIOLOGICAL TRANSPORT.Ion Channels: Gated, ion-selective glycoproteins that traverse membranes. The stimulus for ION CHANNEL GATING can be due to a variety of stimuli such as LIGANDS, a TRANSMEMBRANE POTENTIAL DIFFERENCE, mechanical deformation or through INTRACELLULAR SIGNALING PEPTIDES AND PROTEINS.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).Spectrometry, Fluorescence: Measurement of the intensity and quality of fluorescence.Hydrophobic and Hydrophilic Interactions: The thermodynamic interaction between a substance and WATER.Chromosome Mapping: Any method used for determining the location of and relative distances between genes on a chromosome.ComputersBlotting, Northern: Detection of RNA that has been electrophoretically separated and immobilized by blotting on nitrocellulose or other type of paper or nylon membrane followed by hybridization with labeled NUCLEIC ACID PROBES.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.Adsorption: The adhesion of gases, liquids, or dissolved solids onto a surface. It includes adsorptive phenomena of bacteria and viruses onto surfaces as well. ABSORPTION into the substance may follow but not necessarily.Gold: A yellow metallic element with the atomic symbol Au, atomic number 79, and atomic weight 197. It is used in jewelry, goldplating of other metals, as currency, and in dental restoration. Many of its clinical applications, such as ANTIRHEUMATIC AGENTS, are in the form of its salts.Introns: Sequences of DNA in the genes that are located between the EXONS. They are transcribed along with the exons but are removed from the primary gene transcript by RNA SPLICING to leave mature RNA. Some introns code for separate genes.Amides: Organic compounds containing the -CO-NH2 radical. Amides are derived from acids by replacement of -OH by -NH2 or from ammonia by the replacement of H by an acyl group. (From Grant & Hackh's Chemical Dictionary, 5th ed)Carbohydrate Sequence: The sequence of carbohydrates within POLYSACCHARIDES; GLYCOPROTEINS; and GLYCOLIPIDS.Carrier Proteins: Transport proteins that carry specific substances in the blood or across cell membranes.Dimerization: The process by which two molecules of the same chemical composition form a condensation product or polymer.Protein Subunits: Single chains of amino acids that are the units of multimeric PROTEINS. Multimeric proteins can be composed of identical or non-identical subunits. One or more monomeric subunits may compose a protomer which itself is a subunit structure of a larger assembly.Sulfates: Inorganic salts of sulfuric acid.Collagen: A polypeptide substance comprising about one third of the total protein in mammalian organisms. It is the main constituent of SKIN; CONNECTIVE TISSUE; and the organic substance of bones (BONE AND BONES) and teeth (TOOTH).Trypsin: A serine endopeptidase that is formed from TRYPSINOGEN in the pancreas. It is converted into its active form by ENTEROPEPTIDASE in the small intestine. It catalyzes hydrolysis of the carboxyl group of either arginine or lysine. EC 3.4.21.4.Glycosides: Any compound that contains a constituent sugar, in which the hydroxyl group attached to the first carbon is substituted by an alcoholic, phenolic, or other group. They are named specifically for the sugar contained, such as glucoside (glucose), pentoside (pentose), fructoside (fructose), etc. Upon hydrolysis, a sugar and nonsugar component (aglycone) are formed. (From Dorland, 28th ed; From Miall's Dictionary of Chemistry, 5th ed)Alkylation: The covalent bonding of an alkyl group to an organic compound. It can occur by a simple addition reaction or by substitution of another functional group.Protein Stability: The ability of a protein to retain its structural conformation or its activity when subjected to physical or chemical manipulations.Smell: The ability to detect scents or odors, such as the function of OLFACTORY RECEPTOR NEURONS.DNA Restriction Enzymes: Enzymes that are part of the restriction-modification systems. They catalyze the endonucleolytic cleavage of DNA sequences which lack the species-specific methylation pattern in the host cell's DNA. Cleavage yields random or specific double-stranded fragments with terminal 5'-phosphates. The function of restriction enzymes is to destroy any foreign DNA that invades the host cell. Most have been studied in bacterial systems, but a few have been found in eukaryotic organisms. They are also used as tools for the systematic dissection and mapping of chromosomes, in the determination of base sequences of DNAs, and have made it possible to splice and recombine genes from one organism into the genome of another. EC 3.21.1.Microscopy, Electron, Transmission: Electron microscopy in which the ELECTRONS or their reaction products that pass down through the specimen are imaged below the plane of the specimen.Glycosylation: The chemical or biochemical addition of carbohydrate or glycosyl groups to other chemicals, especially peptides or proteins. Glycosyl transferases are used in this biochemical reaction.Carbohydrates: The largest class of organic compounds, including STARCH; GLYCOGEN; CELLULOSE; POLYSACCHARIDES; and simple MONOSACCHARIDES. Carbohydrates are composed of carbon, hydrogen, and oxygen in a ratio of Cn(H2O)n.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.Epitopes: Sites on an antigen that interact with specific antibodies.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.Genomic Library: A form of GENE LIBRARY containing the complete DNA sequences present in the genome of a given organism. It contrasts with a cDNA library which contains only sequences utilized in protein coding (lacking introns).User-Computer Interface: The portion of an interactive computer program that issues messages to and receives commands from a user.Polymerase Chain Reaction: In vitro method for producing large amounts of specific DNA or RNA fragments of defined length and sequence from small amounts of short oligonucleotide flanking sequences (primers). The essential steps include thermal denaturation of the double-stranded target molecules, annealing of the primers to their complementary sequences, and extension of the annealed primers by enzymatic synthesis with DNA polymerase. The reaction is efficient, specific, and extremely sensitive. Uses for the reaction include disease diagnosis, detection of difficult-to-isolate pathogens, mutation analysis, genetic testing, DNA sequencing, and analyzing evolutionary relationships.Gene Expression: The phenotypic manifestation of a gene or genes by the processes of GENETIC TRANSCRIPTION and GENETIC TRANSLATION.Chemistry, Pharmaceutical: Chemistry dealing with the composition and preparation of agents having PHARMACOLOGIC ACTIONS or diagnostic use.Cross-Linking Reagents: Reagents with two reactive groups, usually at opposite ends of the molecule, that are capable of reacting with and thereby forming bridges between side chains of amino acids in proteins; the locations of naturally reactive areas within proteins can thereby be identified; may also be used for other macromolecules, like glycoproteins, nucleic acids, or other.Computational Biology: A field of biology concerned with the development of techniques for the collection and manipulation of biological data, and the use of such data to make biological discoveries or predictions. This field encompasses all computational methods and theories for solving biological problems including manipulation of models and datasets.Chromatography: Techniques used to separate mixtures of substances based on differences in the relative affinities of the substances for mobile and stationary phases. A mobile phase (fluid or gas) passes through a column containing a stationary phase of porous solid or liquid coated on a solid support. Usage is both analytical for small amounts and preparative for bulk amounts.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.Sequence Homology: The degree of similarity between sequences. Studies of AMINO ACID SEQUENCE HOMOLOGY and NUCLEIC ACID SEQUENCE HOMOLOGY provide useful information about the genetic relatedness of genes, gene products, and species.Antibodies, Monoclonal: Antibodies produced by a single clone of cells.Disulfides: Chemical groups containing the covalent disulfide bonds -S-S-. The sulfur atoms can be bound to inorganic or organic moieties.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.Insect Proteins: Proteins found in any species of insect.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)Plasmids: Extrachromosomal, usually CIRCULAR DNA molecules that are self-replicating and transferable from one organism to another. They are found in a variety of bacterial, archaeal, fungal, algal, and plant species. They are used in GENETIC ENGINEERING as CLONING VECTORS.Spectrometry, Mass, Electrospray Ionization: A mass spectrometry technique used for analysis of nonvolatile compounds such as proteins and macromolecules. The technique involves preparing electrically charged droplets from analyte molecules dissolved in solvent. The electrically charged droplets enter a vacuum chamber where the solvent is evaporated. Evaporation of solvent reduces the droplet size, thereby increasing the coulombic repulsion within the droplet. As the charged droplets get smaller, the excess charge within them causes them to disintegrate and release analyte molecules. The volatilized analyte molecules are then analyzed by mass spectrometry.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.Ions: An atom or group of atoms that have a positive or negative electric charge due to a gain (negative charge) or loss (positive charge) of one or more electrons. Atoms with a positive charge are known as CATIONS; those with a negative charge are ANIONS.Isoenzymes: Structurally related forms of an enzyme. Each isoenzyme has the same mechanism and classification, but differs in its chemical, physical, or immunological characteristics.Internet: A loose confederation of computer communication networks around the world. The networks that make up the Internet are connected through several backbone networks. The Internet grew out of the US Government ARPAnet project and was designed to facilitate information exchange.Sequence Analysis, Protein: A process that includes the determination of AMINO ACID SEQUENCE of a protein (or peptide, oligopeptide or peptide fragment) and the information analysis of the sequence.Chymotrypsin: A serine endopeptidase secreted by the pancreas as its zymogen, CHYMOTRYPSINOGEN and carried in the pancreatic juice to the duodenum where it is activated by TRYPSIN. It selectively cleaves aromatic amino acids on the carboxyl side.Mutagenesis, Site-Directed: Genetically engineered MUTAGENESIS at a specific site in the DNA molecule that introduces a base substitution, or an insertion or deletion.Quaternary Ammonium Compounds: Derivatives of ammonium compounds, NH4+ Y-, in which all four of the hydrogens bonded to nitrogen have been replaced with hydrocarbyl groups. These are distinguished from IMINES which are RN=CR2.Binding Sites, Antibody: Local surface sites on antibodies which react with antigen determinant sites on antigens (EPITOPES.) They are formed from parts of the variable regions of FAB FRAGMENTS.Evolution, Molecular: The process of cumulative change at the level of DNA; RNA; and PROTEINS, over successive generations.Time Factors: Elements of limited time intervals, contributing to particular results or situations.Escherichia coli Proteins: Proteins obtained from ESCHERICHIA COLI.Saccharomyces cerevisiae: A species of the genus SACCHAROMYCES, family Saccharomycetaceae, order Saccharomycetales, known as "baker's" or "brewer's" yeast. The dried form is used as a dietary supplement.

The urinary elimination profiles of diazepam and its metabolites, nordiazepam, temazepam, and oxazepam, in the equine after a 10-mg intramuscular dose. (1/20240)

A method for the extraction of diazepam and its metabolites (nordiazepam, temazepam, and oxazepam) from equine urine and serum and their quantitation and confirmation by liquid chromatography-tandem mass spectrometry is presented. Valium, a formulation of diazepam, was administered at a dose of 10 mg intramuscularly to four standard-bred mares. Diazepam is extensively metabolized in the horse to nordiazepam, temazepam, and oxazepam. Diazepam urinary concentrations were found to be less than 6 ng/mL. Nordiazepam was found to be mainly in its glucuronide-conjugated form and was measured out to a collection time of 53-55 h. Oxazepam and temazepam were entirely conjugated, and their urinary concentrations were measured out to collection times of 121 h and 77-79 h, respectively. Diazepam and nordiazepam were measured in equine postadministration serum out to collection times of 6 and 54 h, respectively. Oxazepam and temazepam were not detected in postadministration serum.  (+info)

A single membrane-embedded negative charge is critical for recognizing positively charged drugs by the Escherichia coli multidrug resistance protein MdfA. (2/20240)

The nature of the broad substrate specificity phenomenon, as manifested by multidrug resistance proteins, is not yet understood. In the Escherichia coli multidrug transporter, MdfA, the hydrophobicity profile and PhoA fusion analysis have so far identified only one membrane-embedded charged amino acid residue (E26). In order to determine whether this negatively charged residue may play a role in multidrug recognition, we evaluated the expression and function of MdfA constructs mutated at this position. Replacing E26 with the positively charged residue lysine abolished the multidrug resistance activity against positively charged drugs, but retained chloramphenicol efflux and resistance. In contrast, when the negative charge was preserved in a mutant with aspartate instead of E26, chloramphenicol recognition and transport were drastically inhibited; however, the mutant exhibited almost wild-type multidrug resistance activity against lipophilic cations. These results suggest that although the negative charge at position 26 is not essential for active transport, it dictates the multidrug resistance character of MdfA. We show that such a negative charge is also found in other drug resistance transporters, and its possible significance regarding multidrug resistance is discussed.  (+info)

Stabilization of poly-L-lysine/DNA polyplexes for in vivo gene delivery to the liver. (3/20240)

We are developing a self-assembling non-viral in vivo gene delivery vehicle based on poly-l-lysine and plasmid DNA. We have characterized poly-l-lysines of different chain lengths for DNA condensation and strength of DNA binding. Poly-l-lysine chains >20 residues bound DNA efficiently in physiological saline, while shorter chains did not. Attachment of asialoorosomucoid to PLL increased the PLL chain length required for efficient DNA binding in saline and for efficient DNA condensation. By electron microscopy, poly-l-lysine/DNA polyplexes appeared as toroids 25-50 nm in diameter or rods 40-80 nm long; conjugation of asialoorosomucoid to the polylysine component increased the size of resulting polyplexes to 50-90 nm. In water, poly-l-lysine and asialoorosomucoid-PLL polyplexes have effective diameters of 46 and 87.6 nm, respectively. Polyplexes containing only poly-l-lysine and DNA aggregated in physiological saline at all charge ratios and aggregated at neutral charge ratios in water. Attachment of asialoorosomucoid lessened, but did not eliminate, the aggregation of PLL polyplexes, and did not result in efficient delivery of polyplexes to hepatocytes. Conjugation of polyethylene glycol to poly-l-lysine sterically stabilized resulting polyplexes at neutral charge ratios by shielding the surfaces. For efficient in vivo gene delivery, polyplexes will need to be sterically stabilized to prevent aggregation and interaction with serum components.  (+info)

Isolation of SMTP-3, 4, 5 and -6, novel analogs of staplabin, and their effects on plasminogen activation and fibrinolysis. (4/20240)

Four novel triprenyl phenol metabolites, designated SMTP-3, -4, -5, and -6, have been isolated from cultures of Stachybotrys microspora IFO 30018 by solvent extraction and successive chromatographic fractionation using silica gel and silica ODS columns. A combination of spectroscopic analyses showed that SMTP-3, -4, -5, and -6 are staplabin analogs, containing a serine, a phenylalanine, a leucine or a tryptophan moiety in respective molecules in place of the N-carboxybutyl portion of the staplabin molecule. SMTP-4, -5, and -6 were active at 0.15 to 0.3 mM in enhancing urokinase-catalyzed plasminogen activation and plasminogen binding to fibrin, as well as plasminogen- and urokinase-mediated fibrinolysis. On the other hand, the concentration of staplabin required to exert such effects was 0.4 to 0.6 mM, and SMTP-3 was inactive at concentrations up to 0.45 mM.  (+info)

Novel selective inhibitors for human topoisomerase I, BM2419-1 and -2 derived from saintopin. (5/20240)

Compounds BM2419-1 and -2 were isolated from a culture broth of a fungus Paecilomyces sp. BM2419. It was shown that these novel compounds were artifacts derived from saintopin, a dual inhibitor of topoisomerase I and II by independent processes. In the human topoisomerase I inhibition assay using the recombinant Saccharomyces cerevisiae, BM2419-1 and -2 inhibited selectively the yeast growth dependent on human topoisomerase I induction with IC50 values of 0.3 ng/ml and 6.0 ng/ml, respectively.  (+info)

Apicularens A and B, new cytostatic macrolides from Chondromyces species (myxobacteria): production, physico-chemical and biological properties. (6/20240)

A novel macrolide, apicularen A, was produced by several species of the genus Chondromyces. Initially it was discovered by bioassay-guided RP-HPLC-fractionation of culture extracts of Chondromyces robustus, strain Cm a13. Apicularen A showed no antimicrobial activity, but was highly cytotoxic for cultivated human and animal cells, with IC50 values ranging between 0.1 and 3 ng/ml. A cometabolite of apicularen A, the N-acetylglucosamine glycoside apicularen B, was distinctly less cytotoxic with IC50 values between 0.2 and 1.2 microg/ml, and showed weak activity against a few Gram-positive bacteria. Apicularen A is chemically closely related to the salicylihalamides A and B from the marine sponge Haliclona sp.  (+info)

BE-31405, a new antifungal antibiotic produced by Penicillium minioluteum. I. Description of producing organism, fermentation, isolation, physico-chemical and biological properties. (7/20240)

A new antifungal antibiotic, BE-31405, was isolated from the culture broth of a fungal strain, Penicillium minioluteum F31405. BE-31405 was isolated by adsorption on high porous polymer resin (Diaion HP-20), followed by solvent extraction, precipitation and crystallization. BE-31405 showed potent growth inhibitory activity against pathogenic fungal strains such as Candida albicans, Candida glabrata and Cryptococcus neoformans, but did not show cytotoxic activity against mammalian cells such as P388 mouse leukemia. The mechanism studies indicated that BE-31405 inhibited the protein synthesis of C. albicans but not of mammalian cells.  (+info)

Structure of actinotetraose hexatiglate, a unique glucotetraose from an actinomycete bacterium. (8/20240)

An Actinomycete strain A499 belonging to the genera Amycolatopsis or Amycolata isolated from a Western Australian soil sample produced the cyclic decapeptide antibiotic quinaldopeptin (1), together with the actinotetraose hexatiglate (2), the hexa-ester of a novel non-reducing glucotetraose.  (+info)

The rates of aromatic nucleophilic substitution reactions in liquid ammonia are much faster than those in protic solvents indicating that liquid ammonia behaves like a typical dipolar aprotic solvent in its solvent effects on organic reactions. Nitrofluorobenzenes (NFBs) readily undergo solvolysis in liquid ammonia and 2-nitrofluorobenzene is about 30 times more reactive than the 4-substituted isomer. Oxygen nucleophiles, such as alkoxide and phenoxide ions, readily displace fluorine of 4-NFB in liquid ammonia to give the corresponding substitution product with little or no competing solvolysis product. Using the pKa of the substituted phenols in liquid ammonia, the Brønsted βnuc for the reaction of 4-NFB with para-substituted phenoxides is 0.91, indicative of the removal of most of the negative charge on the oxygen anion and complete bond formation in the transition state and therefore suggests that the decomposition of the Meisenheimer σ-intermediate is rate limiting. The aminolysis of ...
Bimolecular nucleophilic substitution (SN2) reactions are concerted, meaning they are a one step process. This means that the process whereby the nucleophile attacks and the leaving group leaves is simultaneous. Hence, the bond-making between the nucleophile and the electrophilic carbon occurs at the same time as the bond-breaking between the electophilic carbon and the halogen.. The potential energy diagram for an SN2 reaction is shown below. Upon nucleophilic attack, a single transition state is formed. A transition state, unlike a reaction intermediate, is a very short-lived species that cannot be isolated or directly observed. Again, this is a single-step, concerted process with the occurrence of a single transition state.. ...
The term SN2 means that two reactants are involved in the rate determining step. This means the nucleophile will attack the electrophilic carbon at the same time as the leaving group leaves. This leads to a 5 membered transition state. Since the nucelophile is coming into the molecule at the same time as the leaving group leaves it has to attack from the back. If the molecule is initially chiral it will lead to inversion of stereochemistry.. ...
A similarity search and molecular modeling study suggested the 2′-aryl-2-arylbenzothiazole framework as a novel scaffold for the design of COX-2-selective inhibitors. Conventional Suzuki coupling conditions did not furnish the designed compounds in good yield from 2′-bromo-2-arylbenzothiazole as the starting
Theoretical studies of the interplay between radical and ionic reactions. How do radicals influence the course of ionic reactions? What happens to the SN2 substitution mechanism if we introduce a neighboring radical center? Does a "Methylenology-Principle" exist, which relates nucleophilic substitution reactions in radicals to those in closed shell substrates? Are there analogies between addition reactions to C-C double bonds (such as in the Michael- or SN2-reactions) and addition reactions to radical centers? These are just some of the questions we try to answer using modern ab initio methods in combination with various approaches to model solvent effects. The aim of these studies is to improve the understanding of a large number of experimental observations on ionic reactions in radicals.. ...
Offered as CHEM 408 and BCBP 408.) This advanced seminar will focus on the ways in which chemical approaches have been used to study and engineer biological systems. We will explore a series of case studies in which the tools of chemistry have been brought to bear on biological questions and seek to answer the following: Did the application of small molecules that were designed and synthesized by chemists allow the researchers to elucidate biological phenomena that would have remained opaque using genetic and biochemical approaches? Do the findings suggest further experiments? If so, could follow-up experiments be carried out with known techniques, or would development of further chemical tools be required? Topics will include: the design and synthesis of chemical modulators of gene expression, signal transduction, and protein-protein interactions; chemical approaches to protein engineering and drug-target validation; activity-based proteomics; and chemical tagging of biomolecular targets. ...
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TY - JOUR. T1 - (+)-Phorboxazole A synthetic studies. Identification of a series of highly cytotoxic C(45-46) analogues. AU - Smith,Amos B.. AU - Razler,Thomas M.. AU - Pettit,George R.. AU - Chapuis,Jean Charles. PY - 2005/9/29. Y1 - 2005/9/29. N2 - (Chemical Equation Presented) Effective, scalable total syntheses and biological evaluation of six phorboxazole A analogues (1-6) have been achieved. Importantly, the C(45-46)-saturated, C(45-46)-alkenyl, and the C(45-46)-E-chloroalkenyl congeners (4, 5, and 6, respectively) reveal low nanomolar tumor cell growth inhibitory activity (GI50s) similar to or, in some cell lines, greater than that of the phorboxazoles across a diverse panel of human cancer cell lines.. AB - (Chemical Equation Presented) Effective, scalable total syntheses and biological evaluation of six phorboxazole A analogues (1-6) have been achieved. Importantly, the C(45-46)-saturated, C(45-46)-alkenyl, and the C(45-46)-E-chloroalkenyl congeners (4, 5, and 6, respectively) reveal ...
The synthesis of indaphyrins, novel meso-tetraarylsecochlorin-derived chromophores incorporating o-phenyl-to-beta-linkages, is described. Oxidative diol cleavage of meso-tetraaryl-2,3-dihydroxy-2,3-chlorins results in the formation of a secochlorin bisaldehyde. Depending on the reaction conditions during the ring cleavage reaction, one or two of the aldehyde groups react with the adjacent o-phenyl positions, leading to an intramolecular electrophilic aromatic substitution of the o-phenyl proton, and the establishment of a direct o-phenyl-to-beta-linkage. The initially formed carbinol is spontaneously oxidized to the corresponding ketone. This modification forces the aryl groups into co-planarity with the macrocycle, allowing for interactions between the pi-electrons of the aryl groups, the ketone linkage, and those of the chromophore, resulting in a significant electronic modulation of the porphyrinic pi-system. The UV-vis spectroscopic properties of the free base, CuII, NiII, and ZnII indaphyrins are
Molecular structure of the title compound, C12H15F2N2O+ C6H2N3O7-, showing the cation-anion unit that comprises the asymmetric unit, the disorder of F1 (F1A &am
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The effects of functional groups on the benzimidazole rings, length of the conjugated chain and alkyl groups bonded to the nitrogen atoms on the ground and excited state behaviors of the 1,1′,3,3′-tetraethyl-5,5′,6,6′-te ...
60. A method of preparing α-galactoceramide analog having the following Formula III: ##STR00117## wherein:R21 is OH, F or NH2,X is O, S, S(O), S(O2), or NH,R11 is H or an ester of a fatty acid having the Formula C(═O)R20, wherein R2O is a linear or branched, saturated or unsaturated alkyl chain preferably having from 1 inclusive to 15 inclusive carbon atoms, more preferably R11 is H or an acetyl group,R10 is a substituted or unsubstituted C1 to C30 alkyl group, substituted or unsubstituted aryl group, or substituted or unsubstituted arylalkyl group, andR9 is CH3 or a linear or branched or unsubstituted C1-C30 alkyl chain, preferably a C3-C7 or C13-C20 alkyl chain which may contain at least one heteroaryl group such as the following groups: ##STR00118## wherein R12 is preferentially H or CH3 or a linear or branched C1-C10 alkyl chain, or R9 is a linear or branched C1-C30 alkyl chain containing an heteroatom, such as a chain of the following Formula: ##STR00119## wherein:0,q,10,0,x,30,0,p,30, ...
... such as SATA, HPG, Sulfo-NHS-Acetate, and Trauts Reagent are useful for adding labels to or blocking functional groups on proteins, peptides, and other molecules.
This analysis provides the first precise crystal and molecular structural parameters for α-D-glucose. The C-C, C-H, and O-H bond lengths deviate only slightly from their means of 1.523 Å, 1.098 Å, and 0.968 Å. The C(1)-O(1) bond length, 1.389 Å, is significantly shorter than the mean value, 1.420 Å, of the other C-O bonds. The valence angle of the ring oxygen is 113.8 degrees. ...
Molecular structure of (I) showing the atom labelling scheme. Displacement ellipsoids are drawn at the 30% probability level. H atoms are represented as small s
Symmetry and Molecular Structures Some Readings Chemical Application of Group Theory F. A. Cotton Symmetry through the Eyes of a Chemist I. Hargittai and M. Hargittai The Most Beautiful Molecule - an Adventure
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For more than 50 years, the transatlantic partnership between the United States and Europe has been the linchpin of this countrys foreign...
Background with molecular structure. Abstract molecules in flat style. Download a Free Preview or High Quality Adobe Illustrator Ai, EPS, PDF and High Resolution JPEG versions. ID #13929352.
XCrySDen 1.5.60 :: DESCRIPTION XCrySDen (Crystalline Structures and Densities under the X-Window environment.) is a crystalline and molecular structure visualisation program, which aims at display of isosurfaces a
Cas Index,Name Index,APIs,Pharmaceutical intermediates,Fine chemicals,Browse by Compound Class,Browse by Functional Group,27652-89-7,,Capot Chemical
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A general redox‐neutral approach into the o‐,o′‐heteroatom‐linked N‐(hetero)aryl‐imidazole family of heteroaromatics has been developed. New types of ...
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What is a chemical synthesis ? It consists in one or several chemical reactions that lead to the production of a chemical compound
Vol 70: 1-(3,4-Di-meth-oxy-phen-yl)-3-phenyl-prop-2-en-1-one.. This article is from Acta Crystallographica Section E: Structure Reports Online, volume 70.AbstractIn the title compound. Biblioteca virtual para leer y descargar libros, documentos, trabajos y tesis universitarias en PDF. Material universiario, documentación y tareas realizadas por universitarios en nuestra biblioteca. Para descargar gratis y para leer online.
Previously, we have reported on the crystal and molecular structures, and spectroscopic properties ... normal and pathological conditions [26].
Get an in-depth review and ask questions about Nucleophilic aromatic substitution (8). See what people are saying about Nucleophilic aromatic substitution (8).
View Notes - Lecture #25 (Chapter 21) from CHEM 325BL at USC. Phenols and Aryl Halides Nucleophilic Aromatic Substitution Phenols Phenols have the hydroxyl group attached to a benzene ring. The name
1. A process for producing a polyalkylene glycol derivative of the formula (X): R--(OA)nOH (X) wherein R represents a hydrocarbon group having 1 to 7 carbon atoms, a protective group of a hydroxyl group, a protective group of an amino group, a protective group of an aldehyde group, a protective group of a carboxyl group or a protective group of a mercapto group; OA is an oxyalkylene group having 2 to 4 carbon atoms; and n is an average number of moles of the oxyalkylene group added and is 600 to 2000, the process comprising the following steps (A), (B), (C) and (D): Step (A): a step of adding 5 to 50% by mol of an alkali catalyst to a compound represented by the formula (Y): R--OH (Y) wherein R represents a hydrocarbon group having 1 to 7 carbon atoms, a protective group of a hydroxyl group, a protective group of an amino group, a protective group of an aldehyde group, a protective group of a carboxyl group or a protective group of a mercapto group, Step (B): a step of reacting an alkylene oxide ...
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Close The Infona portal uses cookies, i.e. strings of text saved by a browser on the users device. The portal can access those files and use them to remember the users data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser. ...
The nitro group of methyl 3-nitropyridine-4-carboxylate (1) has successfully been replaced by fluoride anion via nucleophilic aromatic substitution to give the 3-fluoro- pyridine-4-carboxylate 2.
Nomenclature. Electrophilic substitutions reactions of fNomenclature. Electrophilic substitutions reactions of furan, thiophene, pyrrole, indole, benzofuran and benzothiophene; reactions with bases, nucleophiles and metallations reactions. Synthesis of Paal-Knorr, Knorr, Hantzsch, Feist-Benary, Fischer, Reissert. The use of N-oxides of pyridine in substitution reactions of the pyridine nucleus. Reaction of Chichibabin and metallation of the alkyl pyridines. Synthesis from 1,5-diketones, followed by oxidation, synthesis of Hantzsch. Synthesis of pyrimidine nucleus from 1,3-dicarbonyl compounds (β-diketones + amidine, β-diketones + guanidine). Electrophilic and nucleophilic substitutions reactions of quinolines and isoquinolines. Skraup and Bischler-Napieralski synthesis.. ...
Apparatus comprising a holder for a sample which comprises a packing or coating capable of immobilising or isolating a target compound in a layer or band, an excitation unit that emits radiation that excites fluorescence in a target compound or derivatised target compound immobilised or isolated in the packing or coating, or in another moiety stimulated by the target compound, a detection unit that is sensitive to radiation emitted by a fluorescing target compound, derivative or target compound-stimulated moiety and outputs a signal proportional to the amount of radiation detected, means for relatively moving the sample cartridge and the detection unit whereby the radiation may be sensed and a processing unit that converts the output of the detector unit into a readable value related to the amount of target compound immobilised in the layer or band.
Authors: OFENTSE MAZIMBA Abstract: 6$H$-Benzo[$c$]chromen-6-ones serve as core structures of secondary metabolites and are of considerable pharmacological importance. Natural sources produce limited quantities, hence the need for synthetic procedures for 6$H$-benzo[$c$]chromen-6-ones, which are herein reviewed. The literature describes protocols such as the Suzuki coupling reactions for the synthesis of biaryl, which then undergoes lactonization, reactions of 3-formylcoumarin (chromenones) with 1,3-bis(silylenol ethers), radical mediated cyclization of arylbenzoates, metal or base catalyzed cyclization of phenyl-2-halobenzoates and 2-halobenzyloxyphenols, and benzoic acid coupling with benzoquinone using electrophilic metal-based catalyst. The efficient and simple procedures are those involving the reactions of Michael acceptor (chromenones and chalcones) with 1,3- and 1,5-dicarbonyl compounds. Keywords: 6$H$-Benzo[$c$]chromen-6-ones, benzopyranone, biaryls, Suzuki coupling, Michael addition, ...
In this paper, we developed a new method using 4-bromoacetophenone as the starting material, with tosylhydrazide and two arylboronic acids using Barluenga and Suzuki couplings in a four-component one-pot reaction to afford the target product 4-benzyl-1,1′-biphenyls. This system that we have developed enables the use of easily accessible starting materials and can be employed on a wide variety of substrates with good functional group tolerance. In particular, this protocol can be applied to the synthesis of 4-(1-([1,1′-biphenyl]-4-yl)ethyl)pyridine derivatives, a class of potential analogs of CPY17 inhibitors of prostate cancer.
A multi-application IC card system and method is disclosed providing a secure data transmission technique. The method is used, for example, to load an application from an application provider, which could be remote, to an IC card. At least a portion of the application is encrypted using a transfer key. The transfer key is then encrypted using the public key of a public/secret key pair of the intended IC card to form a key transformation unit. The encrypted application and key transformation unit are then sent to the IC card and the IC card decrypts the key transformation unit using its secret key. The transfer key is then recovered and used to decrypt the encrypted application. The application can then by stored on the IC card and accessed by the card user.
Structure-Property Relationship Discotic Liquid Crystals. CHM3T1 Lecture-3. M. Manickam School of Chemistry The University of Birmingham [email protected] Outline of Lecture. Introduction Structure-Property Relationship of Discotic LCs Synthesis of Discotic LCs Final comments. Slideshow 6642390 by rogan-reid
ORGANIC COMPOUNDS -- PART OF THE CLASS 532-570 SERIES : : : Hetero ring is five-membered consisting of one nitrogen and four carbons (e.g., halopyrrolidines, etc.) : Polycyclo ring system having the five-membered hetero ring as one of the cyclos : Bicyclo ring system having the five-membered hetero ring as one of the cyclos (e.g., octahydroindoles, etc.) : Additional polycyclo heterocyclic ring system attached directly or indirectly to the bicyclo ring system by nonionic bonding : The additional polycyclo heterocyclic ring system has a lactone ring as one of the cyclos : Ring carbon of each of the two five-membered hetero rings is bonded directly to chalcogen or nitrogen (e.g., both rings may be bonded to the same nitrogen atom or to different nitrogen atoms, etc ...
Design and synthesis of new chemical entities (NCEs) for biological evaluation, to explore the functions of biologically active lead structures by modifying them (lead optimisation) and enhancing the biological or medical significance with simpler scaffolds designed for ease of synthesis, development of new synthetic methodologies for construction of various heterocyclic ring systems present in natural products, design and development of new reactions, methods, reagents, and strategies that introduce fundamentally novel ways of synthesizing complex molecules of biological or medicinal significance, molecular docking and computational simulation studies, study of structure activity relationship (SAR) of synthesized derivatives for various biological activities, total synthesis of biologically active natural products ...
The course will provide students with a knowledge of natural products obtained from animals and plants, including marine organisms, with the emphasis on the isolation, structure determination, biosynthetic origin, synthesis, mode of action and medicinal properties of substances.. ...
Iwata, C.; Takemoto, Y.; Kubota, H.; Yamada, M.; Uchida, S.; Tanaka, T.; Imanishi, T., 1989: Synthetic studies on spirovetivane phytoalexins. III. A total synthesis of (+or-)-lubiminol
Malaria is a devastating disease that impacts approximately 215 mil sufferers annually among whom around 650 0 pass away (Who all 2011 The pass on of the condition can normally end up being controlled by way of a mix of vector control and chemotherapy. bioactivities natural basic products are actually valuable lead Cangrelor (AR-C69931) manufacture buildings for drug breakthrough (Mayer et al. 2010 Their additional development into medications is however frequently hampered by way of a lack of knowledge of their mode of action. As a result several strategies for the recognition of the direct focuses on of bioactive natural products have been developed in the past few years (Lomenick et al. 2011 Rix and Superti-Furga 2009 Among them proteome labeling strategies such as activity-based protein profiling (ABPP) have evolved into reliable tools for the recognition of protein focuses on of potentially bioreactive natural small molecules (B?ttcher et al. 2010 Cravatt et al. 2008 Deu et al. 2012 Heal et ...
The ionic bond is much weaker than a covalent bond. A quaternary ammonium or a nitro onlinne can be substituted by lSF with a nucleophilic aromatic substitution reaction 9,10.
For the polyhalogenated ethanes and propanes in addition to the nucleophilic substitution reactions, degradation of these compounds can occur through the base-mediated loss of HX. Depending on structure type, elimination or dehydrohalogenation may be the dominant reaction pathway at environmentally relevant pHs. This process often results in the formation of halogenated alkenes, which can be more persistent and of more concern than substitution products. For a number of the polyhalogenated aliphatics, both neutral and base-mediated hydrolysis will occur at ambient environmental pH and that the relative contributions of these processes will be dependent on the degree and pattern of halogen substitution. The rates of dehydrohalogenation reactions will be dependent on the strength of the C-X bond being broken in the elimination process. Accordingly, it is expected that the ease of elimination of X will follow the series Br > Cl > F ...
We have carried out a theoretical study of the geometrical and electronic structures of a family of planar dimers constituted by zinc(II) pyrazinoporphyrazine and zinc(II) phthalocyanine with peripheral electron-donating and electron-withdrawing substituents R [where R = OH (1), C(CH3)3 (2), CH3 (3), C6H5 (4), H (5), CO2H (7), NO2 (7), and PO3H2 (8)]. The complexes are connected by varying the bridge (B) ligand, where, in 1 9, B is CH= and, in 10 12, B is N=, O , and S , respectively. The CO2H group was included in complexes identified as 9 12. This was done because of the known properties of this group in acting as an anchor to adsorb a dye onto a semiconductor oxide. The aim of this work was to provide a useful theoretical basis for the design and screening of new potential dye candidates to be used in these devices, based on the properties of the dyes suitable for their good performance in solar cells, such as frontier molecular orbital spatial distributions; charge-separated states in the ...
In continuation of our interest in the field of asymmetric synthesis and total synthesis of natural products, most of them have several stereogenic centers. Th...
otherwise the warranty only applies for a period of one (1) year from the date of Stille invoice on labor.. The warranties set forth herein do not cover the following Products: (i) consumable items, including but not limited to drapes, (ii) used or refurbished equipment, (iii) Products serviced by anyone other than Stille or its authorized representatives during the Warranty Period.. If Purchaser discovers within this Warranty Period a failure of the Covered Products to conform to specifications or a defect in material or workmanship, Purchaser must promptly notify Stille by calling Stille Customer Service during normal business hours. Stilles warranty obligations will apply only to such notifications made during the warranty period and will not apply to notifications made after warranty expiration.. If Purchaser promptly notifies Stille of Purchasers warranty claim and makes the Covered Product available for service, Stille will, at Stilles option, either repair, adjust or replace (with new ...
2-(furan-3-yl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane 248924-59-6 route of synthesis, 2-(furan-3-yl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane chemical synthesis methods, 2-(furan-3-yl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane synthetic routes ect.
All living cells escape genetic imprisonment by incorporating post-translational modifications such as glycosylation into virtually all translated cellular proteins. This creates the true complexities of the cellular life that are orders of magnitudes more advanced than the human genome and a necessity for life. Despite technical advancements in the analysis of cell surface components, the repertoire of the glycome structures and their cellular interactions are immense and often too complex to decipher. Instead we propose a bottom-up approach using defined Glyco-modules creating an artificial glycocalyx (glycocalyxification) that can be used to systematically resolve the complex interactions on cellular-size membranes. There are several interesting applications within this area to investigate: (i) can we systematically build-up an artificial glycoxalyx from a plain cellular-sized membrane vesicles? (ii) can we complement the existing cellular glycocalyx with a synthetic glycocalyx components to ...
To equip students with a knowledge of natural products obtained from a range of sources including plants and marine organisms with the emphasis on the medicinal properties of substances; to describe extraction techniques and how these influence the chemical composition of the extract; to define compound classes of active constituents; to delineate the biosynthesis of selected compound classes; to show how selected compounds can be synthesised including a description of some industrial syntheses; to equip students with a basic understanding of how bioactive natural products are believed to work; to place natural products in the wider context of bioactive compounds.. ...
Chiral centers are tetrahedral carbon atoms that are connected to four different substituents. To locate a chiral center in a compound, first draw out the compound to show all of its bonds. Then,...
View Notes - CH19 March 31 from CHEM 2212 at UGA. Wittig Reaction: Mechanism of Addition Aldehydes and Unsymmetrical Ketones: Title: Jul 14 - 8:30 AM (4 of 6) Wittig Reaction Practice Problems:
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The overall theme of the lab is understanding the molecular consequences of posttranslational modifications (PTMs) including glycosylation and ubiquitination. These modifications expand the chemical diversity available to cells and living organisms. We specifically focus on the development of chemical tools as attractive methods for dissecting these biochemical pathways.. Currently we are applying these chemical approaches to reveal roles for PTMs in cellular responses is processes associated with changes in metabolism and stress. Recent evidence suggests that these pathways are important contributors to a variety of human diseases including neurodegeneration and cancer. To accomplish our scientific goals, members of the lab use combinations of organic synthesis, genetics, protein biochemistry, and cellular biology. View complete research description and publications list in Dr. Pratt group webpage. ...
Functionalized piperidines are found to constitute a very important core in numerous natural products (Desai et al., 1992; Pinder, 1992), synthetic pharmaceuticals (Breman et al., 2001; Watson et al., 2000), and a wide variety of biologically active compounds. In particular, 1,4-disubstituted piperidine scaffolds find useful applications as established drugs (Targum et al., 1995; Schotte et al.,1996), and they exhibit a wide range of pharmacological activities including antibacterial (Zhou et al., 2007), antimalarial (Misra et al., 2009), anticonvulsant, anti-inflammatory (Bin et al., 2001), and enzyme inhibitory activity (Agrawal & Somani, 2009; Dekus et al., 2007). Moreover a large number of compounds bearing piperidine scaffold have entered into preclinical and clinical trials over the last few years (Kamei et al., 2005). Hence, investigation of the structural features of biologically relevant piperidine derivatives is demanding. In continuation of our structural studies of densely ...
Our research group is working on the medicinal-chemical development of subtype selective inhibitors of the four GABA transport proteins mGAT1 - mGAT4. As ligand-receptor interaction generally represents highly specific processes of recognition, our particular emphasis is on the synthesis and biological evaluation of enantiomerically pure compounds. We also develop new methods of synthesis, particularly asymmetric syntheses for the expression of test compound in enantiomerically pure form. The biological screening is conducted with radioligand binding assays and a new method employing mass spectrometry we have developed to assess the ligand-receptor interaction (MS-Binding Studies).The results of the biological assays are employed in molecular modeling to create structure-activity-relationships (SAR) and 3-D bond models, which then serve as a basis for further optimizations. ...
Nicotinamide (NIC), also called vitamin B-3, is commonly known as a pellagra-preventive drug. Citric acid (CA) is a weak tribasic acid, generally used as a flavouring and chelating agent. Herein, a combined experimental and quantum chemical approach was adopted to study the structural properties and spectroscopic signatures of nicotinamide-citric acid (NIC-CA) cocrystals using monomer (2NIC + CA) and cluster (4NIC + CA) models. In the cluster model, two additional NIC molecules were attached to cover the nearest possible interactions to understand the complete molecular geometries and hydrogen bonding interactions present in the cocrystal. In addition to this, our strategy was to calculate and analyse the physicochemical properties of NIC and CA along with improved properties after NIC-CA cocrystal formation. The observed red shift in the stretching modes of ...
N-α-METHYL-D-VALINE HYDROCHLORIDE 210830-32-3 route of synthesis, N-α-METHYL-D-VALINE HYDROCHLORIDE chemical synthesis methods, N-α-METHYL-D-VALINE HYDROCHLORIDE synthetic routes ect.
Thiophene-2-carbothioamide | C5H5NS2 | CID 737237 - structure, chemical names, physical and chemical properties, classification, patents, literature, biological activities, safety/hazards/toxicity information, supplier lists, and more.
The Golden research group uses synthetic medicinal chemistry to address issues in chemical biology. We develop synthetic methodology to generate new chemical architecture and explore its associated pharmacology. Currently, projects in the Golden laboratory focus on chemical methodology development and the optimization of anti-infective and anticancer agents in cell and animal models. We work closely with expert collaborators who assess our compounds against various biological targets, and through structural manipulation of our chemical scaffolds, we refine properties to achieve a desired activity profile. Several projects are underway, and a few are represented below.. ...
Learn more about 1-thiophene-2-carbonyl-piperidine-4-carboxylic-acid. We enable science by offering product choice, services, process excellence and our people make it happen.
Four Steps To Success. By Donald Brown. What is success? For the business owner, success is defined as "the achievement of wealth and fame". For many, wealth and fame remain only dreams, but there is a four step formula that will allow anyone who truly desires success to reach their dreams. Step # 1. Know your product or service Before you begin promoting your product or service, you must learn everything about it. You must know the benefits inside and out. Dont become a modern day snake oil salesmen by promoting something you know nothing about. Your reputation and credibility are on the line. Promoting something just for the money is a sure fire way to damage your reputation and lose a customer for life. Promote only products or services you truly believe in and know something about. Step #2 Set Goals Your goal is your roadmap to success. Without goals you wander aimlessly. Until youve sat down and committed your goals to writing, you are doing nothing more than daydreaming. Make your goal ...
Learn more about 3-5-4-ethylpiperazin-1-yl-methyl-1-2-4-oxadiazol-3-yl-benzaldehyde-hydrochloride. We enable science by offering product choice, services, process excellence and our people make it happen.
Two SPPS strategies are now considered standard procedures, the Boc/Bzl and the Fmoc/tBu protection scheme. Fmoc/tBu- and Boc/Bzl-SPPS differ in the choice of the temporary Nα (Boc or Fmoc) and permanent (side-chain: tBu-related or Bzl-related) protecting groups. The type of Nα-blocking group determines the options for side-chain protection and the conditions of final cleavage (removal of the permanent protective groups and splitting from the carrier). Fmoc-SPPS is considered the milder method. ...
As the title says; Four Steps to Proper Cash Management, the tips come with four steps to follow so that companys cash properly managed .
R2 and R3 are each independently selected from the group consisting of hydrogen, deuterium, amino, halo, hydoxy, nitro, carboxy, (C2-C6)alkenyl, (C2-C6)alkynyl, trifluoromethyl, trifiuoromethoxy,(C1-C6)alkyl, (C1-C6)alkoxy, (C3-C10)cycloalkyl wherein the alkyl, alkoxy or cycloalkyl groups are optionally substittued by one to three groups selected from halo, hydroxy, carboxy, amino (C1-C6)alkylthio,(C1-C6)alkylamino, ((C1-C6)alkyl)2amino, (Cs-C9)heteroaryl. (C2-C9)heterocycloalkyl, (C3-C9)cycloalkyl or (C6-C10)aryl; or R2 and R3 are each independently (C3-C10)cycloalkyl, (C3-C10)cycloalkoxy,(C1-C6)alkylamino,(C1-C6)alkyl^amino, (C6-C10)arylamino,(C1-C6)alkylthk), (C6-C10)arylthio,(C1-C6)alkylsulfinyl, (C6-C10)arylsulfinyl, (C1-C6)alkylsulfonyl, (C6-C10)arylsulfonyl, (C1-C6)acyl, (C1-C6)alkoxy-CO-NH-, (C1-C6)alkyamino-CO-, (C5-C9)heteroaryl, (C2-C9)heterocycloalkyl or (C6-C10)aryl wherein the heteroaryl, heterocycloalkyl and aryl groups are optionally substituted by one to three halo, ...
Amazing science. I guess in situ chlorine oxidation from trichloroisocyanuric acid is missing to my non-sense education. Will have to revisit Dieckman condensation and Suzuki Coupling. Assuming a potential starting material candidate for Agent Yankee Dodge. ...
Detailed photophysical studies are presented for Cu2Cl2(dppb)2 and Ag2Cl2(dppb)2. Both compounds show very effective thermally activated delayed fluorescence (TADF) at ambient temperature with an emission quantum yield of the Ag(I) complex of ΦPL(300 K) = 93 %. This emission is blue shifted by 65 nm (2500 cm-1) with respect to the emission of the Cu(I) complex, demonstrating a valuable strategy for engineering blue light emitters. Potentially, these materials are well suited for taking advantage of the singlet harvesting effect in an OLED device. Moreover, both compounds do not show effects of concentration quenching at high emitter concentration, a property which might be attractive for reducing the efficiency roll-off at higher current densities. Investigations down to T = 1.6 K show that spin-orbit coupling (SOC) is particularly weak. This is displayed in the very long emission decay times of the triplet states (T1 states) of metal-toligand charge transfer (3MLCT) character, amounting to ...
The present invention refers to an RNA molecule with catalytic activity comprising at least one modified nucleoside, wherein the hydroxy group at the 2-position of the fibose sugar is replaced by a m
You are viewing an interactive 3D depiction of the molecule 4,4-(2,3-diisocyano-1,3-butadiene-1,4-diyl)bisphenol (C18H14N2O2) from the PQR.
The use of catalytic amounts of sodiumhydride as an efficient promoter for the dimerization of aromatic and even heteroaromatic aldehydes under standard laboratory conditions is reported. A range of substituted aromatic and heteroaromatic aldehydes was converted, and the corresponding esters were obtained in good to excellent yields even on a multigram scale.. ...
149246-41-3 - UHPNDZGXGKKNEQ-UHFFFAOYSA-N - 1H-Purine, 6,6-(1,4,10-trioxa-7,13-diazacyclopentadecane-7,13-diyl)bis- - Similar structures search, synonyms, formulas, resource links, and other chemical information.
Proteins are made up of chains of small organic molecules called amino acids such as glycine, alanine, lysine or tryptophan. Amino acids contain an amine functional group, which contains a nitrogen...
In his experiment Sharpless gave mice the drug, gave them radiation treatment, and watched what happened. The result astounded even Sharpless.. "If you dont give the mouse the drug, it dies of radiation sickness," he says. "If you give it the drug, it lives; it has nearly complete protection. You never ever get an experiment like this. It worked the first time and its worked every time since. Young mice, old mice, mice with genetic deficiencies that make them more or less susceptible to radiation. It always works.". It also worked up to twenty hours after the mice had been exposed to radiation.. Sharplesss lab put the drug up against many common chemotherapies, and the drug protected mice against all of them. The idea is that doctors could give the drug to cancer patients. Chemo or radiation would attack the cancer cells while the p16 drug protected bone marrow.. Sharpless started a company called G-Zero Therapeutics thats developing a class of p16 compounds for human use. The company has ...
The goal of this work is to examine the solid state structures of compounds that have been designed for increased conjugation and solubility, as these factors are important if these compounds are to be used in the solid state. The impact of three commonly employed molecular design strategies on the solid sta
CPN2H7O5 crystallizes in the orthorhombic Pbca space group. The structure is two-dimensional and consists of two CPN2H7O5 sheets oriented in the (0, 0, 1) direction. C4+ is bonded in a trigonal planar geometry to two N3- and one O2- atom. Both C-N bond lengths are 1.33 Å. The C-O bond length is 1.31 Å. P5+ is bonded in a tetrahedral geometry to four O2- atoms. There are a spread of P-O bond distances ranging from 1.53-1.58 Å. There are two inequivalent N3- sites. In the first N3- site, N3- is bonded in a trigonal planar geometry to one C4+ and two H1+ atoms. There is one shorter (1.02 Å) and one longer (1.03 Å) N-H bond length. In the second N3- site, N3- is bonded in a trigonal planar geometry to one C4+ and two H1+ atoms. Both N-H bond lengths are 1.02 Å. There are seven inequivalent H1+ sites. In the first H1+ site, H1+ is bonded in a single-bond geometry to one N3- atom. In the second H1+ site, H1+ is bonded in a linear geometry to two O2- atoms. There is one shorter (1.02 Å) and one
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Compiles representative subsite-fragment pairs derived from X-ray crystal structures. CSFDB consists of a repository of items, obtained through a surface scanning of targets protein using the Fsubsite software, with information about their chemical similarities. This database is organized in a way that representative fragments as well as fragment members belong to a representative subsite.
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Spherically polymerized polyolefins can be advantageously stabilized by being treated with at least one emulsion or dispersion containing a stabilizer or a mixture of stabilizers and an amine of formula I ##STR1## wherein R 1 is C 1 -C 20 alkyl which may be substituted by --OH, or is C 3 -C 50 alkyl which is interrupted by one or more oxygen atoms, or is C 1 -C 8 alkoxy, and each of R 2 and R 3 independently of the other is hydrogen or has one of the meanings indicated for R 1 , or R 2 and Rphd 3, together with the nitrogen atom to which they are attached, form a 5- to 7-membered heterocyclic ring.
Carboxylic acid is an organic molecule and an acid containing a carboxyl group, formula -COOH. They are a functional group present in both amino acids and fatty acids. Carboxylic acids are weak acids, and therefore dissociate incompletely in water, forming an equilibrium between the RCOOH molecule and the RCOO- and H+ ions. ...
We report the first enantioselective CC bond formation through CO bond cleavage using aryl ester counterparts. This method is characterized by its wide ...
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Pricking a finger everyday is just part of everyday life for many diabetes patients. A non-invasive measurement approach could release them from the constant pain of pin pricks. The linchpin is a biosensor engineered by Fraunhofer ...
Can Toxicity for Different Species be Correlated?: The Concept and Emerging Applications of Interspecies Quantitative Structure-Toxicity Relationship (i-QSTR) Modeling: 10.4018/IJQSPR.2016070102: Experimental evaluation of the toxicity of a compound is an expensive practice, and it requires sacrifice of a large number of animals. As a consequence, in
article{76461d1c-35ab-4466-9bf7-d2c919d7143f, abstract = {Synthesis of the title compounds in four steps using inexpensive collidine and lutidine as starting materials is described.}, author = {Roblou, Emmanuel and Sasaki, I and Pezet, F and Ait-Haddou, H and Vincendeau, S}, issn = {0039-7911}, keyword = {pyridine,nitrile,aldehyde,hydrazone}, language = {eng}, number = {20}, pages = {3743--3749}, publisher = {Marcel Dekker}, series = {Synthetic Communications}, title = {Synthesis of dicyanopyridines}, url = {http://dx.doi.org/10.1081/SCC-200032468}, volume = {34}, year = {2004 ...
Its time to check out a bunch of the tracks I have not posted recently. These are just a few of the songs that would get their own individual posts here on GIMME TINNITUS if I only had the time. Here is the next NOT POSTED mix. Listen. Downloadables: Brass Knuckles (mp3) by Personal and […] more… ...
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2YI5: Co-Crystalization and in Vitro Biological Characterization of 5-Aryl-4-(5-Substituted-2-4-Dihydroxyphenyl)-1,2,3-Thiadiazole Hsp90 Inhibitors.
2YI6: Co-Crystalization and in Vitro Biological Characterization of 5-Aryl-4-(5-Substituted-2-4-Dihydroxyphenyl)-1,2,3-Thiadiazole Hsp90 Inhibitors.
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Bioactive molecules as probes in human biology and disease. Starting from naturally occurring molecules that possess unique anti-cancer activity or neuroprotective/neurotrophic activities, our research incorporates synthetic chemistry and biological efforts to expedite discovery of novel bioactive molecules and to facilitate the study of their biological properties. Chemistry efforts will emphasize the development of modular approaches to target molecules and new methodologies to maximize synthetic efficiency. Biological studies will focus on profiling the activities of selected compounds and identifying their mode of action ...
Method for developing a quantitative structure activity relationship that includes obtaining a training set of chemical compounds with molecular descriptors consisting of a number of multidimensional vectors with an activity class for each of the vectors; partitioning the multidimensional vectors into groups having interdependence; transforming the descriptors such that the interdependence of the groups is lessened; estimating a probability distribution of the descriptors by assuming that a probability distribution of a product of each of the groups is approximately equal to the probability distribution of the molecular descriptors; performing the partitioning, transforming and estimating steps for each of the activity classes; and, developing a probability distribution for the activity classes.
Predictive hologram quantitative structure activity relationship (HQSAR) models were developed for a series of arylsulfonamide compounds acting as specific 5-HT6 antagonists. A training set containing 48 compounds served to establish the model. The best HQSAR model was generated using atoms, bond, and connectivity as
The Quantitative Structure-Activity Relationship of a series of novel Thiazoline derivatives with anticancer activity has been studied by using the density functional theory by B3LYP/ 6-31G. Descriptors of quantum mechanics of 21 thiazoline derivatives with known activity were obtained. Multiple linear regressions were employed to model the relationships between molecular descriptors and biological activity of molecules using stepwise method. The most model shows not only significant statistical quality, but also predictive ability, with the square of adjusted correlation coefficient (R2=0.945) and standard error (SE=0.586). We find that the anticancer activity expressed that as half maximal inhibitory concentration (IC50), closely relates to the highest occupied molecular orbital, dipole moment, softness, hardness, ionization energy, electron affinity. Accordingly can be offered a quantitative model, and interpret the activity of the compounds relying on the multivariate statistical analysis. This
The olefin metathesis reaction has become a widely used method for the construction of new carbon-carbon double bonds. The development of well-defined, ruthenium-based catalysts with high air- and moisture-stability and functional group tolerance has allowed synthetic chemists to exploit this reaction in many areas. The main goal of this thesis was to better understand the impact of changes in catalyst and monomer structure on the olefin metathesis reaction. The introduction of chelating alkylidene ligands to olefin metathesis catalysts has resulted in systems with high activity and stability that, for the most part, are active at or below room temperature. However, for some applications, catalysts that react only at higher temperatures are desirable. Chapter 2 describes the synthesis of latent olefin metathesis catalysts with chelating alkylidenes with a range of donor ligands: including phosphines, pyridines, imines, amines, and thioethers. The nature of the donor ligand was found to have a ...
The marine cyanobacterium Lyngbya majuscula is a prolific producer of bioactive secondary metabolites. Although biosynthetic gene clusters encoding several of these compounds have been identified, little is known about how these clusters of genes are transcribed or regulated, and techniques targeting genetic manipulation in Lyngbya strains have not yet been developed. We conducted transcriptional analyses of the jamaicamide gene cluster from a Jamaican strain of Lyngbya majuscula, and isolated proteins that could be involved in jamaicamide regulation. An unusually long untranslated leader region of approximately 840 bp is located between the jamaicamide transcription start site (TSS) and gene cluster start codon. All of the intergenic regions between the pathway ORFs were transcribed into RNA in RT-PCR experiments; however, a promoter prediction program indicated the possible presence of promoters in multiple intergenic regions. Because the functionality of these promoters could not be verified in vivo,
An enantioselective synthesis of allenes through palladium-catalyzed asymmetric allylic alkylation using a chiral diaminophosphine oxide is described. The asymmetric allylic alkylations proceeded in the presence of a catalytic amount of lithium acetate at 4 °C, affording the chiral allenes in excellent yield with up to 99% ee. ...
TY - JOUR. T1 - Fast Quantitative Detection of Cocaine in Beverages Using Nanoextractive Electrospray Ionization Tandem Mass Spectrometry. AU - Hu, Bin. AU - Peng, Xuejiao. AU - Yang, Shuiping. AU - Gu, Haiwei. AU - Chen, Huanwen. AU - Huan, Yanfu. AU - Zhang, Tingting. AU - Qiao, Xiaolin. PY - 2010/2/1. Y1 - 2010/2/1. N2 - Without any sample pretreatment, effervescent beverage fluids were manually sprayed into the primary ion plume created by using a nanoelectrospray ionization source for direct ionization, and the analyte ions of interest were guided into an ion trap mass spectrometer for tandem mass analysis. Functional ingredients (e.g., vitamins, taurine, and caffeine, etc.) and spiked impurity (e.g., cocaine) in various beverages, such as Red Bull energy drink, Coco-cola, and Pepsi samples were rapidly identified within 1.5 s. The limit of detection was found to be 7 ∼ 15 fg (S/N = 3) for cocaine in different samples using the characteristic fragment (m/z 150) observed in the MS3 ...
One palladium dichloride adduct of a phosphine-pyridine ligand N-diphenylphosphanyl-2-aminopyridine (L1) [(L1)PdCl2] (1) has been prepared and structurally characterized. Compound 1 can be used as an effective catalyst for the Suzuki-Miyaura cross-coupling reactions of unreactive aryl chlorides with aryl boronic acids, and worked much better than its mono- or bidentate phosphine ligands. The reactions with a wide scope of substrates proceeded to give desired products in good to excellent yields.
Molecular structure[edit]. Chemically, carotenes are polyunsaturated hydrocarbons containing 40 carbon atoms per molecule, ...
Molecular structure[edit]. Structure of SMC dimer. Primary structure[edit]. SMC proteins are 1,000-1,500 amino-acid long. They ... Secondary and tertiary structure[edit]. SMC dimers form a V-shaped molecule with two long coiled-coil arms.[14][15] To make ... Nasmyth K, Haering CH (2005). "The structure and function of SMC and kleisin complexes". Annu. Rev. Biochem. 74: 595-648. doi: ... Losada A, Hirano T (2005). "Dynamic molecular linkers of the genome: the first decade of SMC proteins". Genes Dev. 19 (11): ...
Properties and molecular structure. Orbital diagram, after Barrett (2002),[25] showing the participating atomic orbitals from ... 8 molecular lattice in the phase of solid oxygen". Nature. 443 (7108): 201-04. Bibcode:2006Natur.443..201L. doi:10.1038/ ... The spectroscopy of molecular oxygen is associated with the atmospheric processes of aurora and airglow.[48] The absorption in ... Krupenie, Paul H. (1972). "The Spectrum of Molecular Oxygen". Journal of Physical and Chemical Reference Data. 1 (2): 423-534. ...
Mass spectrometry: Used to determine the molecular weight of a compound and from mass spectrum analysis its structure. High ... These problems have been addressed by describing molecular structures using organic nomenclature . ... The structure of methane by pictorial representation of a Lewis diagram showing the sharing of electronpairs between atomic ... Because of molecular complexity, simplified systems of chemical notation have been developed. The latest version is the line- ...
3.1 Molecular structure *3.1.1 Inverted repeats. *3.1.2 Nucleoids. *3.2 DNA repair ... Granum structure The prevailing model for granal structure is a stack of granal thylakoids linked by helical stromal thylakoids ... "Molecular Biology and Evolution. 29 (10): 2937-48. doi:10.1093/molbev/mss101. PMC 3457768. PMID 22446745.. ... Granal structure. Using a light microscope, it is just barely possible to see tiny green granules-which were named grana.[108] ...
"Vectran molecular structure". Archived from the original on 2012-06-05. Retrieved 2012-11-22.. ... Chemical structure of this aramid consists of linearly substituted aromatic rings linked by amide groups. In a similar way, ... liquid-crystal polymers are capable of forming regions of highly ordered structure while in the liquid phase. However, the ...
Molecular structure of methanol. Specialty. Emergency medicine. Symptoms. Decreased level of consciousness, poor coordination, ... Fundamentals of Biochemistry: Life at the Molecular Level. 5th ed. Hoboken, NJ: Wiley, 2008. Print ...
Durup, Jean (1998). "On "Levinthal paradox" and the theory of protein folding". Journal of Molecular Structure. 424 (1-2): 157- ... Journal of Biomolecular Structure and Dynamics. 20 (3): 327-329. doi:10.1080/07391102.2002.10506850. PMID 12437370.. [permanent ... Journal of Biomolecular Structure & Dynamics. 20 (1): 5-6. doi:10.1080/07391102.2002.10506817. ISSN 0739-1102. PMID 12144347. ... The solution to this paradox has been established by computational approaches to protein structure prediction.[3] ...
Aromaticity of 1,3-imidazole in 5+n hetero-bicyclic molecules". Journal of Molecular Structure. 655 (3): 397-403. Bibcode: ... a b c Board review series (BRS)-- Biochemistry, Molecular Biology, and Genetics (fifth edition): Swanson, Kim, Glucksman ... "Histidine biosynthetic pathway and genes: structure, regulation, and evolution". Microbiological Reviews. 60 (1): 44-69. ISSN ... charge is equally distributed between both nitrogens and can be represented with two equally important resonance structures. As ...
Journal of Molecular Structure. 186: 43-52. doi:10.1016/0166-1280(89)87037-X.. .mw-parser-output cite.citation{font-style: ... The combination of three atomic orbitals form three molecular orbitals: one bonding, one non-bonding, and one anti-bonding. The ... The two electrons (corresponding to one bond) in a B−H−B bonding molecular orbital are spread out across three internuclear ... 3 and the dimeric structure of aluminium chloride. This type of bond is also called banana bond. ...
Journal of Molecular Structure. 1077: 101-113. Bibcode:2014JMoSt1077..101J. doi:10.1016/j.molstruc.2014.03.009.. ... Methods in Molecular Biology. Methods in Molecular Biology. 1654. pp. 151-164. doi:10.1007/978-1-4939-7231-9_10. ISBN 978-1- ... for interactions with high molecular weight complexes, large molecule assemblies, even with liposomes,[7] vesicles, nanodiscs,[ ... "Molecular interaction studies using microscale thermophoresis". Assay and Drug Development Technologies. 9 (4): 342-53. doi ...
Journal of Molecular Structure. 785 (1-3): 68-75. doi:10.1016/j.molstruc.2005.09.030.. ... Jaworska, Maria; Stasicka, Zofia (March 2006). "Structure and UV-vis spectroscopy of roussin black salt [Fe4S3(NO)7]−". ...
Lipid Molecular Structure Database. *. Paul, M. (2012). "Chemotaxonomic Investigations on Resins of the Frankincense Species ... Structure[edit]. The boswellic acids are organic acids, consisting of a pentacyclic triterpene, a carboxyl group and at least ... they differ only in their triterpene structure. Acetyl-alpha-boswellic acid and acetyl-beta-boswellic acid, C32H50O4, replace ... and sesquiterpene molecules with small amounts of diterpenoid components being the upper limit in terms of molecular weight).[2 ...
"Journal of Molecular Structure: THEOCHEM. 169: 403-419. doi:10.1016/0166-1280(88)80273-2.. - via ScienceDirect (Subscription ... A molecular orbital exploration of structure, stereochemistry, and reaction dynamics". Inorganic Chemistry. 16 (3): 511-522. ... A linear combination of these four structures, conserving the number of structures, leads to a triply degenerate T2 state and a ... molecular orbital theory[edit]. Hybridisation theory is an integral part of organic chemistry and in general discussed together ...
"Molecular structure of Nucleic Acids". *Linus Pauling *"Sickle Cell Anemia, a Molecular Disease" ...
Molecular structure of 2-monoacylglycerol. Monoglycerides (also: acylglycerols or monoacylglycerols) are a class of glycerides ...
The structure of DNA - J. D. Watson and F. H. C. Crick (1953). "Molecular structure of Nucleic Acids: A structure for ... First molecular protein structure (myoglobin) - J. C. Kendrew; G. Bodo; H. M. Dintzis; R. G. Parrish; H. Wyckoff; D. C. ... Before publishing one of its most famous discoveries, Watson and Crick's 1953 paper on the structure of DNA, Nature did not ... No referee working in the field ... could have kept his mouth shut once he saw the structure".[39] ...
Molecular Structure of Nucleic Acids: A Structure for Deoxyribose Nucleic Acid, Molecular models of DNA, and DNA structure ... The structure was reported in a letter titled "MOLECULAR STRUCTURE OF NUCLEIC ACIDS A Structure for Deoxyribose Nucleic Acid", ... The structure of the DNA double helix. The atoms in the structure are colour-coded by element and the detailed structures of ... "Molecular structure of nucleic acids; a structure for deoxyribose nucleic acid" (PDF). Nature. 171 (4356): 737-38. Bibcode: ...
Hartree-Fock, density-functional, G2, and CBS calculations". Journal of Molecular Structure: THEOCHEM. 668 (2-3): 171-178. doi: ...
Structural biology - a branch of molecular biology, biochemistry, and biophysics concerned with the molecular structure of ... Molecular biology is the study of biology at the molecular level.[43] This field overlaps with other areas of biology, ... Molecular biology - the study of biology and biological functions at the molecular level, some cross over with biochemistry ... along with the discovery of the double helical structure of DNA in 1953, marked the transition to the era of molecular genetics ...
"Molecular Structure of Nucleic Acids: A Structure for Deoxyribose Nucleic Acid" (PDF). Nature. 171 (4356): 737-8. Bibcode: ... Molecular genetics[edit]. DNA, the molecular basis for biological inheritance. Each strand of DNA is a chain of nucleotides, ... The molecular structure of DNA. Bases pair through the arrangement of hydrogen bonding between the strands. ... This structure showed that genetic information exists in the sequence of nucleotides on each strand of DNA. The structure also ...
Journal of Molecular Structure: THEOCHEM. 419 (1-3): 19-27. doi:10.1016/S0166-1280(97)00185-1.. ... Atkins, Peter; de Paula, Julio; Friedman, Ronald (2009). Quanta, Matter, and Change: A Molecular Approach to Physical Chemistry ... is the fine-structure constant, and c is the speed of light. In non-relativistic quantum mechanics, therefore, any atom with an ... Electron atomic and molecular orbitals. The chart of orbitals (left) is arranged by increasing energy (see Madelung rule). Note ...
"Molecular structure of Nucleic Acids". *Linus Pauling *"Sickle Cell Anemia, a Molecular Disease" ... Structure, style, and themes[edit]. Nature and structure of Darwin's argument[edit]. Darwin's aims were twofold: to show that ... 5 Structure, style, and themes *5.1 Nature and structure of Darwin's argument ... The Structure and Distribution of Coral Reefs. *On the Tendency of Species to form Varieties; and on the Perpetuation of ...
"Molecular structure of Nucleic Acids". *Linus Pauling *"Sickle Cell Anemia, a Molecular Disease" ... and the body of his review followed the structure of Vestiges, packed with current evidence to undermine the supposition of ...
Journal of Molecular Structure: THEOCHEM. 180: 125-140. doi:10.1016/0166-1280(88)80084-8.. ... Sapse AM (2000). Molecular Orbital Calculations for Amino Acids and Peptides. Birkhäuser. ISBN 978-0-8176-3893-1.. [page needed ... Structure and conformation[edit]. GABA is found mostly as a zwitterion (i.e. with the carboxyl group deprotonated and the amino ... Many GABA analogues with pharmaceutical applications have more rigid structures in order to control the binding better.[38][39] ...
"Molecular structure of Nucleic Acids". *Linus Pauling *"Sickle Cell Anemia, a Molecular Disease" ...
... structure, physiology and cognitive abilities of the nervous system.[1][2][3][4] ... We know from molecular biology that distinct parts of the nervous system release distinct chemical cues, from growth factors to ... others argue that uncovering structural functional relations depends on including as much neuronal and network structure as ...
"Molecular structure of Nucleic Acids". *Linus Pauling *"Sickle Cell Anemia, a Molecular Disease" ... He gave names to a number of vestigial structures in the book, among them "Olivier's Spalax, which lives underground like the ... His first law stated that use or disuse of a body's structures would cause them to grow or shrink in the course of several ... The first law stated that use or disuse would cause body structures to grow or shrink over the generations. The second law ...
... and comparative molecular similarity indices analysis (CoMSIA) based on three-dimensional quantitative structure-activity ... Molecular Docking and 3D-quantitative Structure Activity Relationship Analyses of Peptidyl Vinyl Sulfones: Plasmodium ... Molecular Docking and 3D-quantitative Structure Activity Relationship Analyses of Peptidyl Vinyl Sulfones: Plasmodium ...
Molecular Spectra and Structure. Leerdoelen. The student is able to explain the structure of molecules. The student is able to ... Omschrijving: In this course the structure of molecular systems, and interaction of light and molecules will be treated based ... 2. Molecular Electronic States. 3. Electronic States of Diatomic Molecules 4. Electron Configuration and Electronic States. 5. ... The student can explain relations between intensities of optical transitions for different degrees of freedom in a molecular ...
The Journal of Molecular Structure is dedicated to the publication of full-length articles and review papers, providing ... Special issues published in Journal of Molecular Structure. * Molecular Spectroscopy and Molecular Structure 2016 Austin J. ... Recently published articles from Journal of Molecular Structure. * Multiple quantitative structure-activity relationships ( ... Molecular and crystal structure and the Hirshfeld surface analysis of 1-amino-1-deoxy-α-d-sorbopyranose and 1-amino-1-deoxy-α-d ...
... 872109. Atmospheric pressure flow reactor ... Citation: Brezinsky, K. and Dryer, F., "Molecular Structure and Component Blending Effects on Knock Related Chemistry," SAE ...
BACK TO PLANT CELL STRUCTURE. Questions or comments? Send us an email.. © 1995-2018 by Michael W. Davidson and The Florida ... Plant vacuoles are also important for their role in molecular degradation and storage. Sometimes these functions are carried ...
BACK TO PLANT CELL STRUCTURE. Questions or comments? Send us an email.. © 1995-2017 by Michael W. Davidson and The Florida ... All of the green structures in plants, including stems and unripened fruit, contain chloroplasts, but the majority of ...
Supercomputers Calculate Structure Of Bones On The Molecular Level. Bone fibers contain an odd couple of gooey protein and ... Modeling the molecular structure of bone fibers would have taken years on a supercomputer. For this study, the calculations ... elucidating how the molecular structure of bone fibers help them take advantage of the best of both worlds. ... Molecular Look. This illustration shows a molecule of collagen (top) next to a molecule of a crystal of hydroxyapatite (bottom ...
Although several membrane biology books are available, they do not integrate recent knowledge gained using modern molecular ... This text attempts to introduce the molecular biology of cell membranes to students and professionals of diverse backgrounds. ... Molecular Biology of Membranes. Book Subtitle. Structure and Function. Authors. * H.R. Petty ... Molecular techniques, such as cDNA cloning and x-ray diffraction, have provided fresh insights into cell membrane structure and ...
Human leukocyte interferon: Relationship between molecular structure and species specificity. M. N. Thang, D. C. Thang, M. K. ... Human leukocyte interferon: Relationship between molecular structure and species specificity. M. N. Thang, D. C. Thang, M. K. ... Human leukocyte interferon: Relationship between molecular structure and species specificity. M. N. Thang, D. C. Thang, M. K. ... Human leukocyte interferon: Relationship between molecular structure and species specificity Message Subject (Your Name) has ...
The three-dimensional molecular structure of the desmosomal plaque.. Al-Amoudi A1, Castaño-Diez D, Devos DP, Russell RB, ... B) The same representation as in A rotated 90°. Next to the zigzag structure shown in A, an additional connection between ... Two molecular layers representing five to six unit cells in the extracellular and intracellular parts are shown. The ... Although 3D structures of the major plaque components are known, the overall architecture remains unknown. We used cryoelectron ...
Molecular Structure Reveals How HIV Infects Cells. The Landmark Finding Will Guide Future Drug Design ... "One thing that weve lacked is a high-resolution molecular picture of the CCR5 receptor structure that we can use for precise ... "Knowing the CXCR4 structure and now the CCR5 structure at this level of detail should accelerate the development of drugs that ... Soon after the structure determination of CCR5, SIMM performed structure-based drug design and has obtained several drug lead ...
Human genetics is the field of biology and genetics that studies the structure and function of genes at a molecular level. The ... Abstract in Science: The Chemical Structure of a Molecule Resolved by Atomic Force Microscopy. (hat tip: Gizmodo). ... To image the chemical structure of a molecule with an AFM, it is necessary to operate in very close proximity to the molecule. ... molecular level at Nano scale dimensions of 1-100nm. The ability to see Nano-sized particles has given rise to a variety of ...
Where did you get the molecular structure is it molecular modelling or single crystal data? ... Tamiflu Molecular Structure. Roche is allegedly struggling to keep up with unprecedented demand for its antiviral Tamiflu in ... I drew it in a chemistry drawing program and used its builtin 3D optimisation to render it as a fairly accurate structure. ...
Festive Flu Virus Structure. A playful image from Rommie Amaro and colleagues uses a festive approach to the serious science of ... The Structures of Life. Reveals how structural biology provides insight into health and disease and is useful in developing new ... In a video interview, biochemist Wes Sundquist discusses how the HIV virus uses molecular pathways in host cells to replicate ...
Its articles discuss molecular structure in chemistry. Journal of Molecular Structure: THEOCHEM. ... Journal of Molecular Structure is a scientific journal published by Elsevier ScienceDirect since 1968. ...
It must be understood that finding the correct molecular structure in a molecular structure database as enormous as PubChem, ... be the molecular property indices. A fingerprint is a subset F. ⊆. {. 1. ,. …. ,. n. }. . Each molecular structure candidate ... without knowing the molecular structure of the compound, and without the need for a database of spectra or molecular structures ... is a vector of n molecular properties for this molecular structure (the desired output). Here, +. 1. denotes the presence and − ...
Antibody Structure and Molecular Immunology. Read the Nobel Lecture. Pdf 578 kB. Copyright © The Nobel Foundation 1972 ...
... ... Better Probes of Molecular Structure Now Possible with MRFMs and Micro-STMs. ... enabling researchers to probe DNA and other molecular-scale structures.. However, he insists that this accomplishment is just ... New Modeling Technique Simulates Full Range of Molecular Detail. University of Michigan Experiment Explores Avalanche Behavior ...
... This site is an overview on viruses. The user ... Material Detail: Viruses: Structure, Function, and Uses - Molecular Cell Biology - NCBI Bookshelf ... Disciplines with similar materials as Viruses: Structure, Function, and Uses - Molecular Cell Biology - NCBI Bookshelf ... Other materials like Viruses: Structure, Function, and Uses - Molecular Cell Biology - NCBI Bookshelf ...
Just enough molecular biology, The genome, Writing a DNA sequence, Central dogma, ... ... So thats protein structure. So another aspect of molecular structure are, so, sort of aspect of structure is transcription ... In this lecture, were going to talk about molecular biology structures, by which I mean structures in the DNA and other ... So, another kind of structure a very different kind of structure is not so much a physical one, but a sequence structure. And ...
The nicotinic cholinergic receptor: correlation of molecular structure with functional properties.. Conti-Tronconi BM, Raftery ...
They are generated by different molecular mechanisms: ED-A+ and ED-B+... ... Engel J (1993) Structure and function of laminin. In: Rohrbach DH, Timpl R (eds) Molecular and cellular aspects of basement ... Molecular variants of fibronectin and laminin: structure, physiological occurrence and histopathological aspects. ... Engvall E (1995) Structure and function of basement membranes. Int J Dev Biol 39:781-787Google Scholar ...
... molecular target-the ?2-adrenergic receptor. The work is particularly exciting because it offers the first glimpse into an ... Scientists Unveil Structure of Molecular Target of Many Drugs. October 29, 2007. ... "Many laboratories around the world are trying to reveal the secrets of these proteins and this new structure takes this field ... To learn more about the NIH Roadmap for Medical Research, visit . Details about the Protein Structure Initiative are available ...
Accurate determination of molecular structure and vibrational force constants by computation. *James E. Boggs1. ... Boggs, J.E. Accurate determination of molecular structure and vibrational force constants by computation. Phys Chem Minerals 14 ... Portalone G, Schultz G, Domenicano A, Hargittai I (1984) Molecular structure and ring distortions of fluorobenzene: An electron ... Fogarasi G, Pulay P (1985) Ab initio calculation of force fields and vibrational spectra inVibrational Spectra and Structure ...
The purpose of this review is to examine current molecular docking strategies used in drug discovery and medicinal chemistry, ... Broadly used in modern drug design, molecular docking methods explore the ligand conformations adopted within the binding sites ... exploring the advances in the field and the role played by the integration of structure- and ligand-based methods. ... Pharmaceutical research has successfully incorporated a wealth of molecular modeling methods, within a variety of drug ...
  • So, if DNA-tagged molecular shapes (whether made of DNA with Rothemund staples, or Schafmeister polymers, or whatever) were allowed to self-assemble to a DNA framework, and then zinc or light (or whatever reagent) were added, then the shapes could bond quite strongly into a single large strong precise molecule. (typepad.com)
  • Dendrimer, molecular structure.Dendrimers are artificially created branched polymers and subbranches along a central backbone of carbon atoms, usually extending from a central atom or ring of atoms. (sciencephoto.com)
  • Molecular Recognition and Polymers covers the fundamental aspects and applications of molecular recognition-in the creation of novel polymeric materials for use in drug delivery, sensors, tissue engineering, molecular imprinting, and other areas. (wiley.com)
  • The focus of this dissertation is to develop a fundamental understanding of process-structure-property relationship in two different classes of polymers: semi-crystalline Ultra High Molecular Weight Polytetrafluoroethylene (UHMWPTFE) and amorphous glassy double network (DN) epoxies. (umass.edu)
  • Brezinsky, K. and Dryer, F., "Molecular Structure and Component Blending Effects on Knock Related Chemistry," SAE Technical Paper 872109, 1987, https://doi.org/10.4271/872109 . (sae.org)
  • I drew it in a chemistry drawing program and used its builtin 3D optimisation to render it as a fairly accurate structure. (sciencebase.com)
  • Its articles discuss molecular structure in chemistry. (wikipedia.org)
  • The purpose of this review is to examine current molecular docking strategies used in drug discovery and medicinal chemistry, exploring the advances in the field and the role played by the integration of structure- and ligand-based methods. (mdpi.com)
  • Our results offer an approach that can aid in predicting these optimal structures, providing the potential to enhance the production of everything from over-the-counter drugs to new LED materials," adds Tuckerman, also a professor at NYU's Courant Institute of Mathematical Sciences and the NYU-East China Normal University Center for Computational Chemistry at NYU Shanghai. (eurekalert.org)
  • A chemical structure with stereo-chemistry bonds is provided for each chemical component, in addition to conventional information, such as Chinese and English names, physical and chemical properties. (springer.com)
  • Now, in an article published today in the journal Nature Plants , Whitehead Institute Member Jing-Ke Weng and first author and Weng lab postdoc Fu-Shuang Li, together with collaborators Professor Mei Hong and graduate student Pyae Phyo from the Department of Chemistry, have used innovative chemical degradation methods and state-of-the-art nuclear magnetic resonance (NMR) spectroscopy to determine the chemical structure of sporopollenin. (phys.org)
  • In addition to solving a longstanding puzzle in plant chemistry, identifying the structure of sporopollenin opens the door for its potential use in a host of other applications. (phys.org)
  • To help complete the puzzle, the researchers collaborated with Mei Hong's group in MIT's Department of Chemistry and used magic-angle-spinning solid-state NMR spectroscopy, which can determine the chemical structures of insoluble compounds by having them interact with magnetic fields. (phys.org)
  • When combined with a heuristic, allowing simultaneous constrained fitting of the high-resolution structures of the major plaque proteins (desmoplakin, plakophilin, and plakoglobin), it reveals their mutual molecular interactions and explains their stoichiometry. (nih.gov)
  • Eventually, however, with help from insights gained during the CXCR4 project, Wu, as a new professor, and her young team of students used a novel "fusion partner" molecule that would hold CCR5 proteins together enough to form usable crystals, together with efforts of computational modeling, compound synthesis and cell signaling assays from Drs. Hualiang Jiang, Hong Liu and Xin Xie's groups at SIMM, which led to the structure determination of CCR5. (scripps.edu)
  • Because of their role in so many medically important processes and the great challenges they present for detailed study, membrane proteins have been one focus of the NIH Roadmap for Medical Research," said NIH Director Elias A. Zerhouni, M.D. "The determination of this structure is an exciting example of the rewards of the Roadmap investment. (scienceblog.com)
  • Many laboratories around the world are trying to reveal the secrets of these proteins and this new structure takes this field to a new level. (scienceblog.com)
  • This is a data set used by Ning Qian and Terry Sejnowski in their study using a neural net to predict the secondary structure of certain globular proteins . (uci.edu)
  • Unlike DNA, RNA can "fold back" on itself to form structures that rival proteins in their complexity. (labmanager.com)
  • The α7β7β7α7 structure is apparent in all 20S proteasome structures, ranging from the simplest structure isolated in Thermoplasma in which there are only single α and β proteins to the more complex eukaryotic structures, comprising seven distinct α and seven distinct β proteins. (mcponline.org)
  • When these proteins sense higher acidity caused by proximity to the target cell, the virus unfurls a protein structure that penetrates the outer membrane of the cell and anchors the virus to the cell, causing infection. (healthcanal.com)
  • Until now, understanding just the molecular makeup of the proteins-and the more aggressive subtypes that cause a rapid acceleration of the disease-has plagued researchers. (medicalxpress.com)
  • Minor groove‐binding architectural proteins: Structure, function, and DNA recognition. (currentprotocols.com)
  • Anne Houdusse has established and clarified the molecular structure and function of myosins - a family of motor proteins vital for muscle contraction and motility processes such as cell division or transport of organelles within cells. (embo.org)
  • A sensor-adaptor mechanism for enterovirus uncoating from structures of EV71. (nature.com)
  • The authors of the research paper have proposed a mechanism for how the motor works by comparing its structure to those of other, similar enzymes called helicases. (phys.org)
  • Understanding the molecular mechanism of partial agonism of the nAChR has great potential for designing novel smoking cessation compounds but is currently hampered by the absence of a high-resolution structure of a eukaryote nicotinic receptor. (esrf.eu)
  • The team confirmed this mechanism by lowering the acidity around the virus, which caused the membrane-penetrating protein structure to detach and refold, showing its status in high and low pH environments. (healthcanal.com)
  • The first part of this dissertation aims at developing experimental techniques for studying the sintering process in-situ and thereby elucidates the molecular mechanism associated with UHMWPTFE sintering. (umass.edu)
  • Portalone G, Schultz G, Domenicano A, Hargittai I (1984) Molecular structure and ring distortions of fluorobenzene: An electron diffraction study, and a comparison with other experimental and ab initio results. (springer.com)
  • Using noncontact atomic force microscopy researchers at IBM , with the help of folks at the Utrecht University, managed to view the structure of pentacene ( a polycyclic aromatic hydrocarbon molecule) down to the resolution of individual atoms. (medgadget.com)
  • MacDonald believes that these micro-STMs could also be used for manufacturing massively parallel micro-robots for information storage and molecular-scale robotics, enabling researchers to probe DNA and other molecular-scale structures. (aps.org)
  • In order to understand the how best to go about predicting these structures, researchers rely on a construct called the free energy surface, a multidimensional mathematical object that reveals optimal spatial or geometrical configurations of a given system--whether it pertains to pharmaceuticals or computer chips. (eurekalert.org)
  • Sporopollenin is extremely inert and resistant to reacting with other chemicals, including the ones researchers typically use to determine the structures of other plant biopolymers, such as polysaccharides, lignin, and natural rubber. (phys.org)
  • Researchers at Purdue and The Catholic University of America have discovered the structure of an enzyme called an ATPase, which is essential for the operation of "molecular motors" that package DNA into the head segment of the T4 virus. (phys.org)
  • The researchers determined the structure of the particular ATPase used to break the high-energy bond that links the phosphate to ADP. (phys.org)
  • The researchers determined the enzyme structure using a technique called X-ray crystallography. (phys.org)
  • Image courtesy of Iowa State University In an article published Dec. 8 in the journal Scientific Reports , a team of Iowa State University researchers presented a novel database that allows scientists to quickly access information on RNA structures encoded within the human genome. (labmanager.com)
  • Researchers establish a method that integrates genetic and molecular data to reveal tissue-specific features that have n. (labmanager.com)
  • In looking at the molecular structure , researchers found that the N-terminus, the creation point of the protein, played an important role in manipulating both the fibrils structures and the aggregation processes. (medicalxpress.com)
  • I don't have a lot of experience with 5'-RACE (in fact it's not working well for my gene), but to avoid trouble derived from secondary structure it should be good to perform the RT at high temperatures (up to 55ºC) and maybe use a PCR kit for GC-rich templates. (protocol-online.org)
  • Perhaps the most fundamental of such molecular processes entails chromatin rearrangements, which prime large changes in gene expression required for differentiation and/or dedifferentiation of progenitor cells. (hindawi.com)
  • We have mapped the fire ant PBAN gene structure and determined the tissue expression level in the central nervous system of the ant. (frontiersin.org)
  • Dynamic changes in the 3D structure of the chromatin in the leg precursor cells bring the Pen enhancer into spatial proximity to the Pitx1 gene, thus enabling the activation of this critical gene specifically in the future leg. (mpg.de)
  • By probing the three dimensional structure of this protein complex, called RNA-Induced Initiation of Transcriptional gene Silencing (RITS), scientists from Cold Spring Harbor Laboratory (CSHL) and their collaborators at St. Jude's Research Hospital have discovered new details of how its various parts or "domains" contribute to heterochromatin assembly and gene silencing. (innovations-report.com)
  • Primary structure of the Saccharomyces cerevisiae GAL4 gene. (asm.org)
  • The fourth and last alignment is the SAM riboswitch which regulates the downstream gene expression by assuming alternative structures upon binding of SAM. (mdc-berlin.de)
  • Ke, Y.Y. & Lin, T.H. Modeling the ligand-receptor interaction for a series of inhibitors of the capsid protein of enterovirus 71 using several three-dimensional quantitative structure-activity relationship techniques. (nature.com)
  • In a video interview, biochemist Wes Sundquist discusses how the HIV virus uses molecular pathways in host cells to replicate itself and spread infection to nearby cells. (nih.gov)
  • However, the number of possible configurations is enormous, and the pathways leading to the most stable ones are complex, which makes these favored structures difficult to nail down in computational searches. (eurekalert.org)
  • While heterogeneity exists in the basic processes displayed during regenerative events in different species-most notably the cellular source contributing to formation of new tissue-activation of conserved molecular pathways is imperative for proper regulation of cells during regeneration. (hindawi.com)
  • Histamine-synthesizing neurons are located in the hypothalamus tuberomamillary nucleus, and these neurons send projections to the CNS through three major pathways, two ascending bundles that innervate the forebrain structures, and one descending bundle reaching the spinal cord. (aspetjournals.org)
  • I will voice over the slides, explaining the concepts, so they're ready to apply molecular orbital theory on the first day of class. (ionicviper.org)
  • After that he moved to USA, where he did his PhD thesis with Robert S. Mulliken from the University of Chicago, on semiempirical MO theory, while holding a post at The Catholic University of America in Washington, D.C.. He realised that the then current approach to molecular orbital theory was incorrect and changed his topic to what resulted in the development of the Roothaan equations. (wikipedia.org)
  • Pulay P, Fogarasi G, Pang F, Boggs JE (1979) Systematic ab initio gradient calculations of molecular geometries, force constants, and dipole moment derivatives. (springer.com)
  • But after carrying out some very good calculations on these he revolted against the Hückel method, threw his excellent calculations out the window, and for his thesis developed entirely independently his now well known all-electron LCAO SCF self-consistent-field method for the calculation of atomic and molecular wave functions, now appropriately referred to, I believe, as the Hartree-Fock-Roothaan method. (wikipedia.org)
  • This fingerprint is then used to search a molecular structure database such as PubChem. (pnas.org)
  • For each of the four RNA families, we compile a multiple-sequence alignment based on experimentally verified transient and dominant (dominant in terms of either the thermodynamic stability and/or attention received so far) RNA secondary structures using a combination of automated search via covariance model and manual curation. (mdc-berlin.de)
  • Pharmaceutical research has successfully incorporated a wealth of molecular modeling methods, within a variety of drug discovery programs, to study complex biological and chemical systems. (mdpi.com)
  • In this "bite" , we're looking at biological and molecular structure, which, in other words refers to what living things are made of . (wikibooks.org)
  • http://www.google.es/patents/US4990502?utm_source=gb-gplus-share Patente US4990502 - Low molecular weight heparins of regular structure, their preparation and their biological uses. (google.es)
  • Low molecular weight heparins of regular structure, their preparation and their biological uses. (google.es)
  • Membranes with hierarchical structure exist in biological systems, and bio-inspired building blocks have been used to grow synthetic analogues in the laboratory through self-assembly. (rsc.org)
  • This is the first time a structure has been determined of an ATPase involved in a DNA packaging motor," said Michael Rossmann, the Hanley Distinguished Professor of Biological Sciences in Purdue's College of Science. (phys.org)
  • The structure of this biological machine is conceptually similar to an engineer's blueprint, and it explains how each of the parts in this complex assemble into a functional complex that efficiently identifies viral DNA when it enters the cell," Wiedenheft says. (infectioncontroltoday.com)
  • The mysteries linked to the structure of the DNA molecule and the biological functions that it undergoes are now solved due to diffraction and microscopy-based imaging techniques. (osa-opn.org)
  • In this review, emphasis is laid on biophysical structure-function analysis and on the cell biological and organismal roles of mammalian CLCs and their role in disease. (mdc-berlin.de)
  • As group leader at the French National Research for Scientific Research (CNRS) Institute Curie in Paris, Anne Houdusse studies the structure and function of biological macromolecules, using biophysical techniques, particularly X-ray crystallography. (embo.org)
  • As in most receptor-structure projects, Wu and her colleagues further stabilized CCR5 with a compound that is known to bind to it, in this case the Pfizer drug maraviroc (sold under the brand name Selzentry® or Celsentri® outside the US). (scripps.edu)
  • We use the fragmentation tree to predict the molecular structure fingerprint of the unknown compound using machine learning. (pnas.org)
  • Regardless whether one searches for the molecular formula of a compound, the pharmacological activity of a compound, or the English name of a plant, the information in the book can be retrieved in multiple ways. (springer.com)
  • 2. The method of claim 1 , wherein the self-assembled structure is prepared from a compound which includes at least one reactive functional group. (google.com.au)
  • 4. The method of claim 1 , wherein the self-assembled molecular structure is prepared from a compound selected from a group consisting of octadecyl isocyanate, dodecyl isocyanate, dodecanol, and 1-octadecanol. (google.com.au)
  • 11. The method of claim 1 , wherein the self-assembled structure comprises a hydroxyl-terminated compound. (google.com.au)
  • 6. The method for the preparation of an organopolysiloxane having a branched molecular structure as claimed in claim 1 in which the alkaline compound is an alkali metal hydroxide or a reaction product thereof with a methylpolysiloxane. (patentgenius.com)
  • 7. The method for the preparation of an organopolysiloxane having a branched molecular structure as claimed in claim 6 in which the amount of the alkaline compound is in such a range that the molar ratio of alkali metal element in the alkalimetal hydroxide to the silicon atoms in the siloxane mixture is in the range from 10.sup. (patentgenius.com)
  • To this end, the neutron structure of H/D exchanged HCA II crystals in complex with AZM was determined. (rcsb.org)
  • They are generated by different molecular mechanisms: ED-A + and ED-B + fibronectin by alternative splicing of pre mRNA, de novo-glycosylated fibronectin by alternative post-translational O -linked glycosylation of the IIICS region, and the laminin isoforms by exchange of single chains of the heterotrimeric molecule. (springer.com)
  • The analysis of cellular and molecular mechanisms involved in natural regenerative phenomena is of great interest to improve medical applications for replacement of lost or damaged tissue in humans. (hindawi.com)
  • The molecular and chemical details are relatively clear for enveloped viruses, such as influenza, HIV and herpes, but up to now the mechanisms for cell entry of non-enveloped viruses, such as BTV and others, had not been well understood. (healthcanal.com)
  • This represents a key piece in the puzzle and a significant step forward for understanding molecular structures and mechanisms in this family of viruses. (healthcanal.com)
  • Zhi-Wen Hu et al, Molecular structure of an N-terminal phosphorylated β-amyloid fibril, Proceedings of the National Academy of Sciences (2019). (medicalxpress.com)
  • The nicotinic cholinergic receptor: correlation of molecular structure with functional properties. (nih.gov)
  • Structure of a human common cold virus and functional relationship to other picornaviruses. (nature.com)
  • Employing structure-based mutagenesis, we investigated the functional role of several homologous contact residues in human α4β2 nAChRs expressed in Xenopus oocytes. (esrf.eu)
  • C) Proposed binding site of a protean ligand (proxyfan) in the inactive hH 3 R 445 as observed by molecular docking, depicting the three functional groups of the ligand important for binding (nitrogen-containing ring, central electronegative group and aromatic ring). (aspetjournals.org)
  • Several of their functional roles are expressed and modulated via RNA structure. (mdc-berlin.de)
  • A given transcript, however, can have more than a single functional RNA structure throughout its life, a fact which has been previously overlooked. (mdc-berlin.de)
  • We here introduce four RNA families with transient RNA structures that play distinct and diverse functional roles. (mdc-berlin.de)
  • She has transferred details seen in atomic resolution structures into functional insight and co-developed a theory that describes the movement of the molecular motors during muscle contraction. (embo.org)
  • Changes in the 3D structure of chromatin as a prerequisite for the development of arms and legs. (mpg.de)
  • The second member of the RITS complex is a protein called Chp1, which acts like a molecular Velcro that specifically attaches to those areas of chromatin that have been chemically marked by methyl groups. (innovations-report.com)
  • Our strategy to understand how these various modules of the RITS complex work has been to find out what these structures look like and how they connect to each other and to chromatin," says Joshua-Tor. (innovations-report.com)
  • The cytoplasmic surface of intercellular junctions is a complex network of molecular interactions that link the extracellular region of the desmosomal cadherins with the cytoskeletal intermediate filaments. (nih.gov)
  • However, because the molecular constituents of such systems of interest and their interactions are often remarkably complex, elucidating these multi-dimensional free energy surfaces in order to derive the best "molecular answers" has presented significant challenges to scientists. (eurekalert.org)
  • The use of specific non-covalent interactions to control polymer structure and properties is a rapidly emerging field with applications in diverse disciplines. (wiley.com)
  • Computer simulation indicates that formation of these hierarchically structured membranes requires strong interactions between molecular components at early time points in order to generate a diffusion barrier between both solutions. (rsc.org)
  • Here, I extend the sympatric sister-species approach, in which variance between lineages and places is minimized, to sister clades and test a fundamental assumption of comparative genetic studies of dispersal: that taxa which evolved at the same time and in the same place will, if they have similar life histories and ecologies, have essentially the same phylogeographic structure. (wiley.com)
  • This drug derives its therapeutic effect from two fundamental molecular actions. (esrf.eu)
  • Address correspondence and reprint requests to Mark A. Magnuson, MD, Departments of Molecular Physiology and Biophysics and of Medicine, 708 Light Hall, Vanderbilt University School of Medicine, Nashville, TN 37232-0615. (diabetesjournals.org)
  • The easy separation of these two classes of human leukocyte interferon makes the purification procedures more rational and will facilitate the preparation of both subspecies to a high degree of molecular homogeneity. (pnas.org)
  • Due to the high degree of molecular customisation during synthesis, they may one day be used for a variety of applications, such as nanotechnology, drug delivery systems, nanoscale batteries, lubricants, catalysts and herbicides. (sciencephoto.com)
  • Experimental studies using structurally designed PAs confirm simulation results by showing that only PAs with high ζ potential are able to yield hierarchically structured membranes. (rsc.org)
  • The great excitement today, which I attempt to convey in this book, is that molecular details are beginning to merge with physiological responses. (springer.com)
  • Rigorously quantifying the influence of intrinsic and extrinsic factors on phylogeographic structure may advance most efficiently through meta-analyses of contemporaneously codistributed taxa, including but not limited to sympatric sister species. (wiley.com)
  • Additionally, we showed how to harness the intrinsic temporal properties of strong-field ionization to image molecular structure at unprecedented, fewfemtosecond resolutions. (osa-opn.org)
  • Malvern's OMNISEC is a Gel Permeation Chromatography (GPC) / Size Exclusion Chromatography (SEC) system for the measurement of absolute molecular weight, molecular size, intrinsic viscosity, branching and other parameters. (aimil.com)
  • Furthermore, the chemical structure of such PAs must incorporate residues that form β-sheets, which facilitates self-assembly of long nanofibers. (rsc.org)
  • Together, these results demonstrate the predictive value of the X-ray crystal structure and highlight the key role of specific amino acid residues in mediating receptor desensitisation and channel opening with limited efficacy, which both are effects thought to facilitate smoking cessation. (esrf.eu)
  • Extensive structure-function analysis identified residues involved in ion permeation, anion-proton coupling and gating and led to attractive biophysical models. (mdc-berlin.de)
  • SHANGHAI, CHINA, AND LA JOLLA, CA - September 12, 2013 - In a long-awaited finding, a team of Chinese and US scientists has determined the high-resolution atomic structure of a cell-surface receptor that most strains of HIV use to get into human immune cells. (scripps.edu)
  • Learn about why and how scientists study these structures. (nih.gov)
  • More than 40 years after beta blockers were first used clinically, scientists can finally get a close-up look at the drugs' molecular target-the ?2-adrenergic receptor. (scienceblog.com)
  • The molecular blueprint of the surveillance complex was determined by a team of scientists in Wiedenheft's lab at MSU using a technique called X-ray crystallography. (infectioncontroltoday.com)
  • A joint research group of the University of Tokyo, Japan Science & Technology Agency (JST) and Japan's Institute of Advanced Industrial Science and Technology (AIST) has succeeded in recording video images showing temporal changes in organic molecule structures. (nikkeibp.co.jp)
  • The object of the research was to "observe changes in an organic molecule as if viewing a molecular model. (nikkeibp.co.jp)
  • Electron microscope image of an organic molecule having a single-stranded chain with a carbon chain length of 12 (above) and its molecular model (below): The bar in the image is 1 nm long. (nikkeibp.co.jp)
  • 1,2 We demonstrated the potential of our methodology by accurately imaging the complete structure of the organic molecule acetylene (C 2 H 2 ), including the C-H bond that is considered highly elusive in conventional diffraction imaging techniques. (osa-opn.org)
  • In eastern Australia, where strong environmental structure is lacking, phylogeographic differences between species that have been codistributed for ∼85% of their evolutionary histories were consistent with tendencies favoured by their modest life-history differences, that is the larger, rarer species had lower genetic diversity. (wiley.com)
  • Analysis of molecular variance of P. stachyoides showed that 4% of the observed genetic differentiation occurred between populations in different k ī puka and 96% when individuals were pooled from all k ī puka. (usgs.gov)
  • Bayesian and multivariate analyses both classified the P. stachyoides and M. zahlbruckneri populations into genetic groups with considerable sub-structuring detected in the P. stachyoides population. (usgs.gov)
  • While the genetic mutations were known from the earlier study, it fell to graduate student Matt Peña to find out how small changes in the DNA structure of the bacteria translated into specific enzymatic changes. (rationalresponders.com)
  • Molecular techniques, such as cDNA cloning and x-ray diffraction, have provided fresh insights into cell membrane structure and function. (springer.com)
  • You just viewed Viruses: Structure, Function, and... . (merlot.org)
  • The molecular potential energy function b. (bio.net)
  • We review here our research to date on the molecular structure and diversity of ant PBAN/pyrokinin peptides in preparation for determining the function of the neuropeptides in ants and other social insects. (frontiersin.org)
  • This model of modular function dictated by structure, can be also generalized to other lncRNAs, beyond the field of X chromosome inactivation, to explain common features of similarly folded RNAs. (frontiersin.org)
  • Francis Crick, the co-discoverer of the double-helix DNA structure, reportedly said "If you want to understand function, study structure. (osa-opn.org)
  • This Science Object is the third of four Science Objects in the Cell Structure and Function SciPack. (nsta.org)
  • In 1-3 hours, the Cell Structure and Function: The Molecular Machinery of Life will help me re-learn, refresh, or learn for the first time some critical science concepts I will have to know to obtain my Science Educator credentials. (nsta.org)
  • This presentation of the molecular structure and function of cells was outstanding! (nsta.org)
  • For optimization, it is necessary to study the structure-function relationship, and molecular dynamic simulation is an effective strategy for screening the molecular structure and even for predicting experimental results. (rsc.org)
  • however, the molecular function of this protein remains uncertain. (arvojournals.org)
  • According to IBM's Dan Rugar, three-dimensional imaging would have tremendous medical implications for controlling diseases and understanding DNA and protein structures. (aps.org)
  • Over the past decade Professor Roy has undertaken the first complete molecular understanding of BTV. (healthcanal.com)
  • It also offers a novel molecular rationale for understanding normal photoreceptor OS architecture and progressive retinal degenerations associated with inherited defects in P/rds. (arvojournals.org)
  • Studies like this can help us understand the physical basis for these kinds of diseases, and they can give us a better understanding for the molecular basis for adaptation,' Shamoo said. (rationalresponders.com)
  • Molecular Mechanics a. (bio.net)
  • Here we review case studies of a range of mineralized tissues, focused on bottom-up models and analyses of the structure and mechanics of mineralized tissues. (aps.org)
  • The student can explain relations between intensities of optical transitions for different degrees of freedom in a molecular system. (rug.nl)
  • This includes its replication cycle from virus entry via genome replication to virus assembly and structure, cell-to-cell transmission, and the engagement of the virus particle with the host cell. (healthcanal.com)
  • Solution structure of a phytocystatin from Ananas comosus and its molecular interaction with papain. (sigmaaldrich.com)
  • A molecular model of AcCYS/papain complex is proposed to illustrate the interaction between AcCYS and papain, indicating a complete blockade of the catalytic triad by AcCYS. (sigmaaldrich.com)
  • Her goal from the beginning was to determine the structures and understand the functions of these two HIV co-receptors and she was very determined which was inspiring," said Stevens. (scripps.edu)
  • Xist, the master regulator of X chromosome inactivation, is a classic example of how lncRNAs can exert multi-layered and fine-tuned regulatory functions, by acting as a molecular scaffold for recruitment of distinct protein factors. (frontiersin.org)
  • It is at the molecular level that many of the basic functions of organisms are carried out such as, protein synthesis, extraction of energy from food, and replication. (nsta.org)