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.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)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)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.Crystallization: The formation of crystalline substances from solutions or melts. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)Cryoultramicrotomy: The technique of using a cryostat or freezing microtome, in which the temperature is regulated to -20 degrees Celsius, to cut ultrathin frozen sections for microscopic (usually, electron microscopic) examination.Iodine Compounds: Inorganic compounds that contain iodine as an integral part of the molecule.Microscopy, Electron, Scanning Transmission: A type of TRANSMISSION ELECTRON MICROSCOPY in which the object is examined directly by an extremely narrow electron beam scanning the specimen point-by-point and using the reactions of the electrons that are transmitted through the specimen to create the image. It should not be confused with SCANNING ELECTRON MICROSCOPY.Bacteriorhodopsins: Rhodopsins found in the PURPLE MEMBRANE of halophilic archaea such as HALOBACTERIUM HALOBIUM. Bacteriorhodopsins function as an energy transducers, converting light energy into electrochemical energy via PROTON PUMPS.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.Halobacterium: A genus of HALOBACTERIACEAE whose growth requires a high concentration of salt. Binary fission is by constriction.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.Molecular Conformation: The characteristic three-dimensional shape of a molecule.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.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).Microscopy, Electron, Scanning: Microscopy in which the object is examined directly by an electron beam scanning the specimen point-by-point. The image is constructed by detecting the products of specimen interactions that are projected above the plane of the sample, such as backscattered electrons. Although SCANNING TRANSMISSION ELECTRON MICROSCOPY also scans the specimen point by point with the electron beam, the image is constructed by detecting the electrons, or their interaction products that are transmitted through the sample plane, so that is a form of TRANSMISSION ELECTRON MICROSCOPY.Electron Transport: The process by which ELECTRONS are transported from a reduced substrate to molecular OXYGEN. (From Bennington, Saunders Dictionary and Encyclopedia of Laboratory Medicine and Technology, 1984, p270)Neutron Diffraction: The scattering of NEUTRONS by matter, especially crystals, with accompanying variation in intensity due to interference effects. It is useful in CRYSTALLOGRAPHY and POWDER DIFFRACTION.Crystallography, X-Ray: The study of crystal structure using X-RAY DIFFRACTION techniques. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)Powder Diffraction: Method of using a polycrystalline powder and Rietveld refinement (LEAST SQUARES ANALYSIS) of X-RAY DIFFRACTION or NEUTRON DIFFRACTION. It circumvents the difficulties of producing single large crystals.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.Models, Molecular: Models used experimentally or theoretically to study molecular shape, electronic properties, or interactions; includes analogous molecules, computer-generated graphics, and mechanical structures.Electron Spin Resonance Spectroscopy: A technique applicable to the wide variety of substances which exhibit paramagnetism because of the magnetic moments of unpaired electrons. The spectra are useful for detection and identification, for determination of electron structure, for study of interactions between molecules, and for measurement of nuclear spins and moments. (From McGraw-Hill Encyclopedia of Science and Technology, 7th edition) Electron nuclear double resonance (ENDOR) spectroscopy is a variant of the technique which can give enhanced resolution. Electron spin resonance analysis can now be used in vivo, including imaging applications such as MAGNETIC RESONANCE IMAGING.Neutrons: Electrically neutral elementary particles found in all atomic nuclei except light hydrogen; the mass is equal to that of the proton and electron combined and they are unstable when isolated from the nucleus, undergoing beta decay. Slow, thermal, epithermal, and fast neutrons refer to the energy levels with which the neutrons are ejected from heavier nuclei during their decay.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.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)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)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.Selenomethionine: Diagnostic aid in pancreas function determination.Electron Probe Microanalysis: Identification and measurement of ELEMENTS and their location based on the fact that X-RAYS emitted by an element excited by an electron beam have a wavelength characteristic of that element and an intensity related to its concentration. It is performed with an electron microscope fitted with an x-ray spectrometer, in scanning or transmission mode.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).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.Biophysical Phenomena: The physical characteristics and processes of biological systems.Particle Size: Relating to the size of solids.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.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)Biophysics: The study of PHYSICAL PHENOMENA and PHYSICAL PROCESSES as applied to living things.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.Optics and Photonics: A specialized field of physics and engineering involved in studying the behavior and properties of light and the technology of analyzing, generating, transmitting, and manipulating ELECTROMAGNETIC RADIATION in the visible, infrared, and ultraviolet range.Bacterial Proteins: Proteins found in any species of bacterium.Thermogravimetry: Technique whereby the weight of a sample can be followed over a period of time while its temperature is being changed (usually increased at a constant rate).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.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)Lasers: An optical source that emits photons in a coherent beam. Light Amplification by Stimulated Emission of Radiation (LASER) is brought about using devices that transform light of varying frequencies into a single intense, nearly nondivergent beam of monochromatic radiation. Lasers operate in the infrared, visible, ultraviolet, or X-ray regions of the spectrum.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.Lipid Bilayers: Layers of lipid molecules which are two molecules thick. Bilayer systems are frequently studied as models of biological membranes.Refractometry: Measurement of the index of refraction (the ratio of the velocity of light or other radiation in the first of two media to its velocity in the second as it passes from one into the other).Light: That portion of the electromagnetic spectrum in the visible, ultraviolet, and infrared range.Surface Properties: Characteristics or attributes of the outer boundaries of objects, including molecules.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.Kinetics: The rate dynamics in chemical or physical systems.Microscopy: The use of instrumentation and techniques for visualizing material and details that cannot be seen by the unaided eye. It is usually done by enlarging images, transmitted by light or electron beams, with optical or magnetic lenses that magnify the entire image field. With scanning microscopy, images are generated by collecting output from the specimen in a point-by-point fashion, on a magnified scale, as it is scanned by a narrow beam of light or electrons, a laser, a conductive probe, or a topographical probe.Powders: Substances made up of an aggregation of small particles, as that obtained by grinding or trituration of a solid drug. In pharmacy it is a form in which substances are administered. (From Dorland, 28th ed)Models, Structural: A representation, generally small in scale, to show the structure, construction, or appearance of something. (From Random House Unabridged Dictionary, 2d ed)Sarcomeres: The repeating contractile units of the MYOFIBRIL, delimited by Z bands along its length.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.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.Binding Sites: The parts of a macromolecule that directly participate in its specific combination with another molecule.Green Chemistry Technology: Pollution prevention through the design of effective chemical products that have low or no toxicity and use of chemical processes that reduce or eliminate the use and generation of hazardous substances.Time Factors: Elements of limited time intervals, contributing to particular results or situations.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).Technology, Pharmaceutical: The application of scientific knowledge or technology to pharmacy and the pharmaceutical industry. It includes methods, techniques, and instrumentation in the manufacture, preparation, compounding, dispensing, packaging, and storing of drugs and other preparations used in diagnostic and determinative procedures, and in the treatment of patients.Electron Transport Complex IV: A multisubunit enzyme complex containing CYTOCHROME A GROUP; CYTOCHROME A3; two copper atoms; and 13 different protein subunits. It is the terminal oxidase complex of the RESPIRATORY CHAIN and collects electrons that are transferred from the reduced CYTOCHROME C GROUP and donates them to molecular OXYGEN, which is then reduced to water. The redox reaction is simultaneously coupled to the transport of PROTONS across the inner mitochondrial membrane.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)Freeze Fracturing: Preparation for electron microscopy of minute replicas of exposed surfaces of the cell which have been ruptured in the frozen state. The specimen is frozen, then cleaved under high vacuum at the same temperature. The exposed surface is shadowed with carbon and platinum and coated with carbon to obtain a carbon replica.Recombinant Proteins: Proteins prepared by recombinant DNA technology.Chemistry, Pharmaceutical: Chemistry dealing with the composition and preparation of agents having PHARMACOLOGIC ACTIONS or diagnostic use.Solubility: The ability of a substance to be dissolved, i.e. to form a solution with another substance. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)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.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)Electron Transport Complex III: A multisubunit enzyme complex that contains CYTOCHROME B GROUP; CYTOCHROME C1; and iron-sulfur centers. It catalyzes the oxidation of ubiquinol to UBIQUINONE, and transfers the electrons to CYTOCHROME C. In MITOCHONDRIA the redox reaction is coupled to the transport of PROTONS across the inner mitochondrial membrane.Phase Transition: A change of a substance from one form or state to another.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.Quartz: Quartz (SiO2). A glassy or crystalline form of silicon dioxide. Many colored varieties are semiprecious stones. (From Grant & Hackh's Chemical Dictionary, 5th ed)Apatites: A group of phosphate minerals that includes ten mineral species and has the general formula X5(YO4)3Z, where X is usually calcium or lead, Y is phosphorus or arsenic, and Z is chlorine, fluorine, or OH-. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)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.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)Spectrometry, X-Ray Emission: The spectrometric analysis of fluorescent X-RAYS, i.e. X-rays emitted after bombarding matter with high energy particles such as PROTONS; ELECTRONS; or higher energy X-rays. Identification of ELEMENTS by this technique is based on the specific type of X-rays that are emitted which are characteristic of the specific elements in the material being analyzed. The characteristic X-rays are distinguished and/or quantified by either wavelength dispersive or energy dispersive methods.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)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.Phosphoric Triester Hydrolases: A class of enzymes that catalyze the hydrolysis of one of the three ester bonds in a phosphotriester-containing compound.Mathematics: The deductive study of shape, quantity, and dependence. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)Nanoparticles: Nanometer-sized particles that are nanoscale in three dimensions. They include nanocrystaline materials; NANOCAPSULES; METAL NANOPARTICLES; DENDRIMERS, and QUANTUM DOTS. The uses of nanoparticles include DRUG DELIVERY SYSTEMS and cancer targeting and imaging.1,2-Dipalmitoylphosphatidylcholine: Synthetic phospholipid used in liposomes and lipid bilayers to study biological membranes. It is also a major constituent of PULMONARY SURFACTANTS.Phosphatidylethanolamines: Derivatives of phosphatidic acids in which the phosphoric acid is bound in ester linkage to an ethanolamine moiety. Complete hydrolysis yields 1 mole of glycerol, phosphoric acid and ethanolamine and 2 moles of fatty acids.Microscopy, Polarization: Microscopy using polarized light in which phenomena due to the preferential orientation of optical properties with respect to the vibration plane of the polarized light are made visible and correlated parameters are made measurable.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.Nanotechnology: The development and use of techniques to study physical phenomena and construct structures in the nanoscale size range or smaller.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.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.Oxidoreductases: The class of all enzymes catalyzing oxidoreduction reactions. The substrate that is oxidized is regarded as a hydrogen donor. The systematic name is based on donor:acceptor oxidoreductase. The recommended name will be dehydrogenase, wherever this is possible; as an alternative, reductase can be used. Oxidase is only used in cases where O2 is the acceptor. (Enzyme Nomenclature, 1992, p9)Purple Membrane: Functionally and structurally differentiated, purple-pigmented regions of the cytoplasmic membrane of some strains of Halobacterium halobium. The membrane develops under anaerobic conditions and is made almost entirely of the purple pigment BACTERIORHODOPSINS. (From Singleton & Sainsbury Dictionary of Microbiology and Molecular Biology, 2d ed)Data Collection: Systematic gathering of data for a particular purpose from various sources, including questionnaires, interviews, observation, existing records, and electronic devices. The process is usually preliminary to statistical analysis of the data.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.Physicochemical Phenomena: The physical phenomena describing the structure and properties of atoms and molecules, and their reaction and interaction processes.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.Chemistry, Physical: The study of CHEMICAL PHENOMENA and processes in terms of the underlying PHYSICAL PHENOMENA and processes.Ferredoxins: Iron-containing proteins that transfer electrons, usually at a low potential, to flavoproteins; the iron is not present as in heme. (McGraw-Hill Dictionary of Scientific and Technical Terms, 5th ed)Cell Membrane: The lipid- and protein-containing, selectively permeable membrane that surrounds the cytoplasm in prokaryotic and eukaryotic cells.Muscles: Contractile tissue that produces movement in animals.Durapatite: The mineral component of bones and teeth; it has been used therapeutically as a prosthetic aid and in the prevention and treatment of osteoporosis.Differential Thermal Analysis: Technique by which phase transitions of chemical reactions can be followed by observation of the heat absorbed or liberated.Freezing: Liquids transforming into solids by the removal of heat.Drug Compounding: The preparation, mixing, and assembling of a drug. (From Remington, The Science and Practice of Pharmacy, 19th ed, p1814)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.Models, Biological: Theoretical representations that simulate the behavior or activity of biological processes or diseases. For disease models in living animals, DISEASE MODELS, ANIMAL is available. Biological models include the use of mathematical equations, computers, and other electronic equipment.Spectrophotometry: The art or process of comparing photometrically the relative intensities of the light in different parts of the spectrum.Electrochemistry: The study of chemical changes resulting from electrical action and electrical activity resulting from chemical changes.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)Myofibrils: The long cylindrical contractile organelles of STRIATED MUSCLE cells composed of ACTIN FILAMENTS; MYOSIN filaments; and other proteins organized in arrays of repeating units called SARCOMERES .Cytochrome c Group: A group of cytochromes with covalent thioether linkages between either or both of the vinyl side chains of protoheme and the protein. (Enzyme Nomenclature, 1992, p539)Photosynthetic Reaction Center Complex Proteins: Protein complexes that take part in the process of PHOTOSYNTHESIS. They are located within the THYLAKOID MEMBRANES of plant CHLOROPLASTS and a variety of structures in more primitive organisms. There are two major complexes involved in the photosynthetic process called PHOTOSYSTEM I and PHOTOSYSTEM II.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.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.Materials Testing: The testing of materials and devices, especially those used for PROSTHESES AND IMPLANTS; SUTURES; TISSUE ADHESIVES; etc., for hardness, strength, durability, safety, efficacy, and biocompatibility.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.Freeze Drying: Method of tissue preparation in which the tissue specimen is frozen and then dehydrated at low temperature in a high vacuum. This method is also used for dehydrating pharmaceutical and food products.Models, Theoretical: Theoretical representations that simulate the behavior or activity of systems, processes, or phenomena. They include the use of mathematical equations, computers, and other electronic equipment.Calcium Phosphates: Calcium salts of phosphoric acid. These compounds are frequently used as calcium supplements.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.Osmium: Osmium. A very hard, gray, toxic, and nearly infusible metal element, atomic number 76, atomic weight 190.2, symbol Os. (From Dorland, 28th ed)Membrane Lipids: Lipids, predominantly phospholipids, cholesterol and small amounts of glycolipids found in membranes including cellular and intracellular membranes. These lipids may be arranged in bilayers in the membranes with integral proteins between the layers and peripheral proteins attached to the outside. Membrane lipids are required for active transport, several enzymatic activities and membrane formation.Computer Simulation: Computer-based representation of physical systems and phenomena such as chemical processes.Myosins: A diverse superfamily of proteins that function as translocating proteins. They share the common characteristics of being able to bind ACTINS and hydrolyze MgATP. Myosins generally consist of heavy chains which are involved in locomotion, and light chains which are involved in regulation. Within the structure of myosin heavy chain are three domains: the head, the neck and the tail. The head region of the heavy chain contains the actin binding domain and MgATPase domain which provides energy for locomotion. The neck region is involved in binding the light-chains. The tail region provides the anchoring point that maintains the position of the heavy chain. The superfamily of myosins is organized into structural classes based upon the type and arrangement of the subunits they contain.Gels: Colloids with a solid continuous phase and liquid as the dispersed phase; gels may be unstable when, due to temperature or other cause, the solid phase liquefies; the resulting colloid is called a sol.Particle Accelerators: Devices which accelerate electrically charged atomic or subatomic particles, such as electrons, protons or ions, to high velocities so they have high kinetic energy.Catalysis: The facilitation of a chemical reaction by material (catalyst) that is not consumed by the reaction.Oxygen: An element with atomic symbol O, atomic number 8, and atomic weight [15.99903; 15.99977]. It is the most abundant element on earth and essential for respiration.Electroplating: Coating with a metal or alloy by electrolysis.Chitosan: Deacetylated CHITIN, a linear polysaccharide of deacetylated beta-1,4-D-glucosamine. It is used in HYDROGEL and to treat WOUNDS.Excipients: Usually inert substances added to a prescription in order to provide suitable consistency to the dosage form. These include binders, matrix, base or diluent in pills, tablets, creams, salves, etc.Nanocomposites: Nanometer-scale composite structures composed of organic molecules intimately incorporated with inorganic molecules. (Glossary of Biotechnology and Nanobiotechology Terms, 4th ed)Drug Carriers: Forms to which substances are incorporated to improve the delivery and the effectiveness of drugs. Drug carriers are used in drug-delivery systems such as the controlled-release technology to prolong in vivo drug actions, decrease drug metabolism, and reduce drug toxicity. Carriers are also used in designs to increase the effectiveness of drug delivery to the target sites of pharmacological actions. Liposomes, albumin microspheres, soluble synthetic polymers, DNA complexes, protein-drug conjugates, and carrier erythrocytes among others have been employed as biodegradable drug carriers.Spectrum Analysis, Raman: Analysis of the intensity of Raman scattering of monochromatic light as a function of frequency of the scattered light.Image Processing, Computer-Assisted: A technique of inputting two-dimensional images into a computer and then enhancing or analyzing the imagery into a form that is more useful to the human observer.Equipment Design: Methods of creating machines and devices.Sulfur: An element that is a member of the chalcogen family. It has an atomic symbol S, atomic number 16, and atomic weight [32.059; 32.076]. It is found in the amino acids cysteine and methionine.Microscopy, Fluorescence: Microscopy of specimens stained with fluorescent dye (usually fluorescein isothiocyanate) or of naturally fluorescent materials, which emit light when exposed to ultraviolet or blue light. Immunofluorescence microscopy utilizes antibodies that are labeled with fluorescent dye.Software: Sequential operating programs and data which instruct the functioning of a digital computer.Electron Transport Chain Complex Proteins: A complex of enzymes and PROTON PUMPS located on the inner membrane of the MITOCHONDRIA and in bacterial membranes. The protein complex provides energy in the form of an electrochemical gradient, which may be used by either MITOCHONDRIAL PROTON-TRANSLOCATING ATPASES or BACTERIAL PROTON-TRANSLOCATING ATPASES.Photosystem I Protein Complex: A large multisubunit protein complex that is found in the THYLAKOID MEMBRANE. It uses light energy derived from LIGHT-HARVESTING PROTEIN COMPLEXES to drive electron transfer reactions that result in either the reduction of NADP to NADPH or the transport of PROTONS across the membrane.
... allows for identification of the crystal orientation at the single volume of the sample from where the pattern was collected. ... neutron diffraction and/or electron diffraction in a Transmission electron microscope. ... Electron backscatter diffraction (EBSD) is a Scanning Electron Microscope based microstructural-crystallographic ... An electron backscatter diffraction pattern of monocrystalline silicon, taken at 20 kV with a field-emission electron source ...
A sample was collected by evaporating the condensed liquid into a Pyrex flask. Finally, using electron diffraction, it was ... When F becomes F−, it gains one electron but has the same number of protons, meaning the attraction of the protons to the ... His model predicts that F donates electrons into a vacant atomic orbital in the atom it is bonded to, giving the bonds a ... In addition, the fluorine atom also receives a certain amount of pi electron density back from the central atom giving rise to ...
Ti2P solved by three-dimensional electron diffraction data collected with the precession technique and high-resolution electron ... Zou, XD, Hovmöller, S. and Oleynikov, P. "Electron Crystallography - Electron microscopy and Electron Diffraction". IUCr Texts ... In addition to electron microscopy images, it is also possible to use electron diffraction (ED) patterns for crystal structure ... electron diffraction data.[19][20] Crystal structures determined via electron crystallography can be checked for their quality ...
Ti2P solved by three-dimensional electron diffraction data collected with the precession technique and high-resolution electron ... Titanium phosphide is classified as a "metal-rich phosphide", where extra valence electrons from the metal are delocalised. ...
... allows for identification of the crystal orientation at the single volume of the sample from where the pattern was collected. ... Traditionally these types of studies have been carried out using X-ray diffraction (XRD), neutron diffraction and/or electron ... towards the diffraction camera, to increase the contrast in the resultant electron backscatter diffraction pattern. The ... Electron backscatter diffraction (EBSD) is a microstructural-crystallographic characterisation technique to study any ...
... (PED) is a specialized method to collect electron diffraction patterns in a transmission ... For a cursory introduction to the theory of electron diffraction, see the theory section of the electron diffraction wiki. For ... This plug-in enables the widely used software package to collect precession electron diffraction patterns without additional ... Precession electron diffraction enables much more direct determination of space group symmetries over other forms of electron ...
... an objective aperture is placed in the diffraction plane so as to only collect electrons scattering through that aperture, ... An annular dark field detector collects electrons from an annulus around the beam, sampling far more scattered electrons than ... These images are formed by collecting scattered electrons with an annular dark-field detector. In conventional dark-field ... Transmission electron microscopy Scanning transmission electron microscopy Dark field microscopy DE Jesson; SJ Pennycook (1995 ...
PEEM measures the coefficient indirectly by collecting the emitted secondary electrons generated in the electron cascade that ... which goes together naturally with low-energy electron diffraction (LEED), and low-energy electron microscopy (LEEM). In ... Low-energy electron microscopy (LEEM) and mirror electron microscopy (MEM):These two electron emission microscopy use electron ... Auger processes and inelastic electron scattering create a cascade of low-energy electrons. Some electrons penetrate the sample ...
... particularly when diffraction data is collected at room temperature instead of the traditional cryogenic temperature (typically ... Flexibility can also be observed in very high-resolution electron density maps produced by X-ray crystallography, ...
Other examples of "instrumental analysis are scanning electron microscopy, X-ray diffraction, and atomic absorption ... analysis is the same process but the carbon dioxide gas that is given off by the digestion will be collected and the type of ...
The corresponding samples were examined with X-ray diffraction and transmission electron microscopy but no quasicrystals were ... The specific composition of the accompanying minerals and the location where the sample was collected-far from any industrial ... as demonstrated by the narrow diffraction peaks. The mechanism of their formation is yet uncertain. ... search for natural quasicrystals around the year of 2000 using the database of the International Centre for Diffraction Data. ...
... three-dimensional electron backscatter diffraction (3D EBSD), with which the sample is serially sectioned and imaged, 3DXRD and ... This signal is transmitted through the sample and collected by two-dimensional detectors. Since different grains satisfy the [[ ... Diffraction Diffraction Tomography Synchrotron Poulsen, H. F.; Nielsen, S. F.; Lauridsen, E. M.; Schmidt, S.; Suter, R. M.; ... 3D X-ray diffraction (3DXRD) is a microscopy technique using hard X-rays (with energy in the 30-100 keV range) to investigate ...
For objects such as crystals and diffraction gratings, diffraction is used with X-rays and electron beams. Measurement ... and the reflected electrons are collected as a photodetector image that is interpreted by a computer. These are not transit- ... For non-relativistic electrons in an electron microscope, the de Broglie wavelength is: λ e = h 2 m e e V , {\displaystyle \ ... The underlying limitations are the beam width and the wavelength of the electron beam (determining diffraction), determined, as ...
Refait, S. H. Drissi, J. P. Mihe, and J.-M. R. Génin (1996): "Conversion electron Mössbauer spectroscopy and X-ray diffraction ... L. Vins, J. Subrt, V. Zapletal, and F. Hanousek (1987): "Preparation and properties of green rust type substances". Collect. ...
Similar diffraction patterns can be produced by scattering electrons or neutrons. X-rays are usually not diffracted from atomic ... They collect X-rays efficiently for photon energies of 0.1 to 30 keV and can achieve gains of 100 to 10000 in flux over using a ... X-ray diffraction is a form of elastic scattering; the outgoing X-rays have the same energy, and thus same wavelength, as the ... In X-ray diffraction a beam strikes a crystal and diffracts into many specific directions. The angles and intensities of the ...
When a diffraction pattern is collected, the data is described in terms of absolute counts of photons or electrons, a ... was imaged using nano area electron diffraction (NAED) with atomic resolution. In principle, electron diffraction imaging ... Coherent electron diffraction imaging works the same as CXDI in principle only electrons are the diffracted waves and an ... to form a diffraction pattern which may be more attractive for 3D applications than electron diffraction since x-rays typically ...
... is an extension of traditional transmission electron microscopy and uses a transmission electron microscope to collect the data ... more effectively suppresses phase and diffraction contrast, providing image intensities that vary with the projected mass- ... This information is collected and used to assemble a three-dimensional image of the target. For biological applications, the ... Electron tomography (ET) is a tomography technique for obtaining detailed 3D structures of sub-cellular macro-molecular objects ...
It was named alacranite after its occurrence in the Alacran mine in Chile due to its similarities in X-ray diffraction patterns ... They reported the composition of alacranite to be As8S9 regarding to the electron-microprobe analyses. When they analyzed a ... A group that studies seafloor hydrothermal, submarine volcanism and regional tectonics in Papua New Guinea collected samples ... The structure of alacranite remained unsolved until further studies collected specimens containing crystals of alacranite. ...
The structure of acetyl cyanide was determined through the joint use of electron diffraction intensities and rotational ... Relatively little data has been collected about the possible thermal and photochemical decompositions and kinetic ... "Molecular structure of acetyl cyanide as studied by gas electron diffraction". Journal of Molecular Structure. 20 (3): 437-448 ...
Detection of secondary electrons[edit]. The most common imaging mode collects low-energy (,50 eV) secondary electrons that are ... Backscattered electrons can also be used to form an electron backscatter diffraction (EBSD) image that can be used to determine ... Nonconductive specimens collect charge when scanned by the electron beam, and especially in secondary electron imaging mode, ... Backscattered electrons (BSE) consist of high-energy electrons originating in the electron beam, that are reflected or back- ...
... structure determination is often aided by complementary data collected from X-Ray diffraction and mass spectrometric ... Due to complex interactions which arise from electron-electron repulsion, algebraic solutions of the Schrödinger equation are ... Unpaired electrons also have a net spin, and an external magnetic field allows for the extraction of similar information ... For this reason, nuclei are of negligible size in relation to much lighter electrons and are treated as point charges in ...
... is a scientific technique using X-ray, neutron, or electron diffraction on powder or microcrystalline ... When the scattered radiation is collected on a flat plate detector, the rotational averaging leads to smooth diffraction rings ... Neutron diffraction[edit]. Main article: Neutron diffraction. Sources that produce a neutron beam of suitable intensity and ... Powder diffraction stands in contrast to single crystal diffraction techniques, which work best with a single, well-ordered ...
... although new techniques such as electron backscatter diffraction have been used. There are three main categories of dinosaur ... "Collecting Eggs," Carpenter (1999); page 117. "Collecting Eggs," Carpenter (1999); pages 117-118. "Collecting Eggs," Carpenter ... The specimen would then be bombarded with electrons. The electrons bounce back off the metal and due to their small size, can ... The sample can then be bombarded by electrons emitted by the same sort of probe used by scanning electron microscopes. Upon ...
... such as low-energy electron diffraction (LEED), helium atom scattering is unique in that it does not penetrate the surface of ... Since single scattering dominates the helium-surface interactions, the collected helium signal easily gives information on the ... in a similar manner to that seen for Bragg scattering in electron and x-ray diffraction. Most helium atom scattering studies ... The most commonly used detector setup is an electron bombardment ion source followed by a mass filter and an electron ...
The single-crystal X-ray diffraction data were collected with an Xcalibur CCD diffractometer, MoKα radiation. The triclinic ( ... The F, Na, Mg, Al, P, Cl, K, Ca, Mn, As, Sb, Pb, and Bi contents in lahnsteinite are below their detection limits by electron ... The current of the absorbed electrons on Co was 0.6 nA. The angle of selection of X-ray radiation was 35°, and the focal ... The X-ray powder diffraction pattern of Lahnsteinite is readily indexed in a triclinic unit cell with the unit-cell dimensions ...
At the electronic level, it depends on whether the electron orbitals are spaced (or "quantized") such that they can absorb a ... Optical fibers doped with a wavelength shifter collect scintillation light in physics experiments. ... Such fiber uses diffraction effects instead of or in addition to total internal reflection, to confine light to the fiber's ... Primary material considerations include both electrons and molecules as follows:. * ...
A new method for collecting complete three-dimensional electron diffraction data is described. Diffraction data is collected by ... Collecting 3D electron diffraction data by the rotation method. Zhang, Daliang Stockholm University, Faculty of Science, ... The main disadvantages of electron crystallography compared to X-ray diffraction are that the data are difficult to collect, ... The new techniques include a digital sampling method for collecting precession electron diffraction data and a rotation method ...
Precession electron diffraction (PED) is a specialized method to collect electron diffraction patterns in a transmission ... For a cursory introduction to the theory of electron diffraction, see the theory section of the electron diffraction wiki. For ... This plug-in enables the widely used software package to collect precession electron diffraction patterns without additional ... Precession electron diffraction enables much more direct determination of space group symmetries over other forms of electron ...
The fibers were, therefore, not useful for performing Transmission electron microscopy or Electron diffraction. ... grids 13 for use with a transmission electron microscope, and wand 14, which is a mobile collecting means for gathering fibers ... by Transmission electron microscopy) and crystalline content (by Electron diffraction) are facilitated using fibers in the size ... Electron Diffraction of B. mori Electrospun Fibers Bombyx mori silk fibers electrospun from the solution of Example 2, using ...
The products were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron ... The diffraction data were collected in a 2θ range of 10° to 60° with a step size of 0.04°. SEM micrographs were recorded with a ... Synchrotron X-ray diffraction patterns were collected at the beam line BL02B2 of SPring-8, Japan, equipped with a large Debye- ... The deposited product was characterized by XRD and scanning electron microscopy (SEM) (Figs. 3b and 3c). The diffraction ...
Ti2P solved by three-dimensional electron diffraction data collected with the precession technique and high-resolution electron ... Zou, XD, Hovmöller, S. and Oleynikov, P. "Electron Crystallography - Electron microscopy and Electron Diffraction". IUCr Texts ... In addition to electron microscopy images, it is also possible to use electron diffraction (ED) patterns for crystal structure ... electron diffraction data.[19][20] Crystal structures determined via electron crystallography can be checked for their quality ...
RED data (individual ED frames) are collected by combining beam tilt and goniometer tilt. After three-dimensional ... Schematic representation of the concept of the rotation electron diffraction (RED) method. ...
... allows for identification of the crystal orientation at the single volume of the sample from where the pattern was collected. ... neutron diffraction and/or electron diffraction in a Transmission electron microscope. ... Electron backscatter diffraction (EBSD) is a Scanning Electron Microscope based microstructural-crystallographic ... An electron backscatter diffraction pattern of monocrystalline silicon, taken at 20 kV with a field-emission electron source ...
The cross marks where the electron back-scattered diffraction pattern (shown in Fig. 4) was collected. (AmMin, v94:841.. ... Electron Density: Bulk Density (Electron Density)=2.86 gm/cc. note: Specific Gravity of Tistarite =3.02 gm/cc.. ... PETistarite = 11.59 barns/electron. U=PETistarite x rElectron Density= 33.16 barns/cc.. ... X Ray Diffraction: By Intensity(I/Io): 1.7033(1), 2.579(0.9), 2.707(0.88),3.734(0.84), 1.489(0.46), 2.242(0.38), 1.8672(0.33), ...
The specimens for transmission electron microscopy and selected area diffraction were collected on a standard 3 mm diameter ... All materials were characterized by x-ray diffraction crystallography, selected area electron diffraction, transmission ... The tin oxide particles were fully crystalline as characterized by electron and x-ray diffraction. Energy dispersive x-ray ... The tin oxide particles were fully crystalline as characterized by electron and x-ray diffraction. Energy dispersive x-ray ...
Not through his geochemistry or his electron diffraction patterns, but through his ability to recognize rocks that would ... When I was young, he took my sister and me to the quarries around the Chicago suburbs to collect rocks. Hed put a few rocks in ... I had a whole bag of collecting vessels to give to all my fellow postdocs and I was fractionating urine and that was not for me ...
... intense pulses allow diffraction data to be collected before the onset of significant radiation damage (`diffraction before ... These ∼200 000 diffraction patterns in turn represented only a fraction of the 2.4 million images that were collected in total ... Protein structure determination by single-wavelength anomalous diffraction phasing of X-ray free-electron laser data. ... both collected at the SPring-8 Angstrom Compact Free-Electron Laser (SACLA). They phased their structure using the method of ...
Diffraction patterns and crystal images were collected by using a FEI Tecnai F20 transmission cryo-electron microscope equipped ... Atomic resolution electron diffraction from amyloid nanocrystals. Diffraction images of Zn2+-NNQQNY (A), Cd2+-NNQQNY (B), ... Strong anomalous signals are not expected for electron diffraction because the energy of the electron beam is far from any ... phases are lost when only diffraction data are collected, either from 2D crystals by electron crystallography or from 3D ...
Transmission electron microscope (TEM) and electron diffraction (ED) examination results indicate that ZnTiO3 crystallites ... Scanning electron microscope (SEM) observations show extensive large agglomeration in the samples. ... The TEM samples were prepared by dispersing the post-calcined powders in an ultrasonic bath and then collected on a copper grid ... Transmission electron microscope (TEM) and electron diffraction (ED) examination results indicate that ZnTiO3 crystallites ...
... electron diffraction), I wondered if there were some way to get absolute stereochemistry ... The authors ended up scanning the electron beam along individual crystals, collecting diffraction patterns as they went, which ... Anyway, that sort of breaks down in electron diffraction, at least if you treat it as a sort of souped-up X-ray diffraction. ... Rotating the sample/electron beam geometry gave more diffraction spots per shot and a better framework for matching them up in ...
... allows for identification of the crystal orientation at the single volume of the sample from where the pattern was collected. ... Traditionally these types of studies have been carried out using X-ray diffraction (XRD), neutron diffraction and/or electron ... towards the diffraction camera, to increase the contrast in the resultant electron backscatter diffraction pattern. The ... Electron backscatter diffraction (EBSD) is a microstructural-crystallographic characterisation technique to study any ...
Electron back-scattered diffraction (EBSD). EBSD data were collected at the Microscopy and Microanalysis Facility, John de ... Data were collected at 20 kV and ~1 nA beam current, with an analytical step size of 2 μm. EBSD data were collected using ... electron backscattered diffraction (EBSD), and atom probe tomography (APT) in order to describe the Cr-spinel reverse zonation ... a Backscattered electron (BSE) image of a Cr-spinel grain with a homogenous core surrounded by a small magnetite rim. Al (b) ...
The objective lens is switched off so that a diffraction pattern is collected - uses modified crystallography programmes to get ... More coherent electron source. Less dampening (loss of scattered electrons). Highly automated - kept in room alone so ... Electron beam hitting the sample can cause it to become charged and this will repel the electrons. ... In DEDs there is a cascade of electrons from the scintillator (rather than photons) and one electron tends to trigger one pixel ...
X-ray diffraction analysis of air samples collected on membrane filters over periods of several days offers a reliable ... X ray diffraction ; Electron microscopy ; Samples ; Air pollution detection ; Reprints ... Use of X-Ray Diffraction to Supplement Electron Microscope Analysis.. ... The transmission electron microscope analysis of enough individual high volume air samples to provide annual average fiber ...
X-ray diffraction, scanning electron microscopy and Raman spectroscopy will be used for mineralogical analysis, (ambient ... Collected samples will be subject to a range of microbiological and mineralogical analytical techniques, both on site and in ...
Quantitative electron diffraction techniques have been especially important for the determination of linear polymer structures ... the usual method for determining crystal structures with electron diffraction data from polymers has been to collect an hk0 net ... has been applied to three-dimensional electron diffraction data sets. Even when electron diffraction intensities are not used ... Quantitative electron diffraction techniques have been especially important for the determination of linear polymer structures ...
Diffraction Based Strain Mapping in Electron Microscopy. Implementation in STEM and Modified Transmission-SEM Fig. 1: (a) High- ... Diffraction patterns were collected with 100 ms exposure on an FEI Ceta camera. A typical diffraction pattern can be seen in ... ScienceElectron and Ion Microscopy. Diffraction Based Strain Mapping in Electron Microscopy. Implementation in STEM and ... Scanning Diffraction in a Modified SEM. Commercial scanning electron microscopes (SEMs) are able to produce a fine electron ...
Selected area electron diffraction patterns were collected and their appearance indicated that the nanoparticle cores are ... The functionalized nanoparticles have been characterized by X-ray powder diffraction, transmission electron microscopy, Fourier ... Changes in the electron spin relaxation time were estimated by observations of the signal line width in electron paramagnetic ... including the relaxation times of the unpaired electrons in the CA. The electron spin relaxation time may be a key factor for ...
Selected area electron diffraction patterns were collected and their appearance indicated that the nanoparticle cores are ... performed by means of transmission electron microscopy, X-ray diffraction and dynamic light scattering. The chemical ... This is considered as an indication of that yttrium dilution changes the electron spin relaxation time in Gd2O3. ... The nanoparticles are crystalline, spherically shaped and in the size range of 2-4 nm as shown by transmission electron ...
X-ray diffraction and optical or electron microscope analysis was conducted by NIOSH and two independent laboratories. All ... Bulk samples of talc (14807966) were collected and personal air sampling was conducted in the mine and the mill. ...
  • Fortunately, electron microscopes can resolve atomic structure in real space and the crystallographic structure factor phase information can be experimentally determined from an image's Fourier transform. (wikipedia.org)
  • The Fourier transform of an atomic resolution image is similar, but different, to a diffraction pattern-with reciprocal lattice spots reflecting the symmetry and spacing of a crystal. (wikipedia.org)
  • Ancillary components include a gas injection system to permit ion beam-assisted and electron beam-assisted chemical vapor deposition, x-ray detectors, micromanipulators, electrical test probes, advanced pattern generators, Fourier transform IR-Raman detectors and orientation imaging systems. (photonics.com)
  • This article presents the three-dimensional reconstruction of the Melbournevirus from single-particle X-ray diffraction patterns collected at the LINAC Coherent Light Source (LCLS) as well as reconstructions from simulated data exploring the consequences of different kinds of experimental sources of noise. (osti.gov)
  • Describe the difference between direct electron detectors and older EM cameras. (brainscape.com)
  • Due to the difficulty of direct electron transfer between Cyt c and a bare electrode, some modified electrodes were used as a tool to investigate the direct electrochemical property. (hindawi.com)
  • They were found to promote the direct electron transfer of Cyt c at electrode surfaces. (hindawi.com)
  • We are actually developing a completely automatic data collection procedure ( Fast EDT ) that, coupled with a new direct electron diffraction camera ( MEDIPIX ), will allow fast data collections in less than 1 minutes drastically reducing the dose suffered by the sample. (iit.it)
  • Daniele Filippetto, a Berkeley Lab scientist, works on the High-Repetition-rate Electron Scattering apparatus (HiRES), which will function like an ultrafast electron camera. (lbl.gov)
  • This newly launched setup, dubbed HiRES (for High Repetition-rate Electron Scattering apparatus), will function like an ultrafast electron camera, potentially producing images that can pinpoint defects and their effects, track electronic and superconducting properties in exotic materials, and detail chemical reactions in gases, liquids and biological samples that are difficult to study using more conventional, X-ray-based experiments. (lbl.gov)
  • The APEX gun is a unique source of ultrafast electrons, with the potential to reach unprecedented precision and stability in timing-ultimately at or below 10 femtoseconds," Filippetto said. (lbl.gov)
  • This computerized rendering shows the layout of the HiRES ultrafast electron diffraction beamline, which is located in the domed Advanced Light Source building at Berkeley Lab. (lbl.gov)
  • Scientists at the University of Toronto have employed femtosecond electron diffraction to study the ultrafast melting of aluminum under illumination by 120-fs pulses of near-IR laser radiation. (photonics.com)
  • Previously, electrons hit a scintillator that produced multiple photons, which went on to trigger multiple pixels. (brainscape.com)
  • In DEDs there is a cascade of electrons from the scintillator (rather than photons) and one electron tends to trigger one pixel. (brainscape.com)
  • However, the interactions between the electrons in the beam and the crystal are much stronger than those between the X-ray photons and the crystal. (elifesciences.org)
  • The implementation of laboratory X-ray microscopes with isotropic sources like laser generated plasmas requires condenser elements which collect photons from large solid angles, match the aperture of the micro zone plate objective to insure high spatial frequency transfer and allow to work at. (ebscohost.com)
  • The trend toward quantitative 3-D nanotomography is being advanced via a focused ion beam in conjunction with equipment to collect various analytical signals, such as electrons, x-rays, ions and photons. (photonics.com)
  • The natural gas and propane gas sources were domestic (kitchen) stoves, and similar particle aggregates collected in the outdoor air were correspondingly identified as carbon nanocrystal aggregates and sometimes more complex aggregates of silica nanocrystals intermixed with the carbon nanotubes and other carbon nanocrystals. (springer.com)
  • Under these conditions, the diffraction signal from a sample-sized particle remained above the average background to a resolution of 4.25 nm. (osti.gov)
  • Respirable dust was collected and the amount of crystalline silica and particle size distribution were measured. (bmj.com)
  • For this purpose, calcium carbonate nanoparticles (average particle size 14.6 nm) were prepared and later applied for effective removal of fluoride from simulated as well as real drinking water (DW) samples collected from different areas of Lahore, Pakistan. (iwaponline.com)
  • In the present study, we used pale yellow coloured bauxite originated from Araku, Vishakapatnam district of Andhra Pradesh, India and studied its structural properties including particle size and nature of metal-oxygen bond using X-ray diffraction (XRD), electron paramagnetic resonance (EPR), optical absorption and near-infrared (NIR ) spectroscopic methods. (scirp.org)
  • Bulk Density (Electron Density)=2.86 gm/cc note: Specific Gravity of Tistarite =3.02 gm/cc. (webmineral.com)
  • U=PE Tistarite x r Electron Density= 33.16 barns/cc. (webmineral.com)
  • It can also aid in the assignment of a structure to a particular point on the reaction pathway in cases where the final electron density is ambiguous. (portlandpress.com)
  • An electron density map. (oregonstate.edu)
  • The electron density had a 'pear shape' when contoured at 5 sigma having dimensions of 6.8 Å×4.9 Å×3.3 Å with the long axis approximately parallel to the CD helix and tilted at approximately 23° to the membrane plane. (royalsocietypublishing.org)
  • Modern X-ray diffraction methods permit an insight into the electron density distribution in a material. (esrf.eu)
  • Experimental data obtained by X-ray diffraction are analysed with the aim to create electron-density maps which reflect the probability of an electron being present at a specific location. (esrf.eu)
  • Electron-density studies by means of high-quality, low temperature X-ray diffraction data provide important experimental information about chemical bonding in crystalline solids, including the identification of bonding interactions, ionicity vs covalency of bonds, and an estimate of the strength of interactions. (esrf.eu)
  • Bonding interactions require the presence of a BCP and/or RCP, and the values of the electron density and its Laplacian at BCPs and RCPs correlate with the properties of the chemical bonds. (esrf.eu)
  • The present experimental static electron density reveals BCPs for all bonds as well as RCPs for three-centre (3c) and polycentre bonds ( Figures 1, 2 ). (esrf.eu)
  • Gradient trajectories of the electron density in high-pressure γ-B 28 phase of boron with BCPs (blue), RCPs (green), and cage critical points (purple) indicated (Image credit: S. Mondal & S. van Smaalen). (esrf.eu)
  • The transitional metal ions present were investigated using electron paramagnetic resonance (EPR) and optical absorption spectra. (scirp.org)
  • Reverse zoning is undetectable under an optical microscope, and it appears either concentric and/or asymmetric when observed in atomic number contrast under backscattered electron (BSE) imaging 9 , or remains non-observable under both an optical microscope and BSE (this study). (nature.com)
  • If the system geometry is well described, it is possible to relate the bands present in the diffraction pattern to the underlying crystal phase and orientation of the material within the electron interaction volume. (wikipedia.org)
  • Meanwhile, in the September 8 Proceedings of the National Academy of Sciences, researchers led by Nikolaus Grigorieff at Janelia and Marcus Fändrich at Ulm University, Germany, describe a detailed structure for Aβ42 fibrils using electron cryomicroscopy. (alzforum.org)
  • While cryoEM's resolution is a tad lower than micro-electron diffraction's, this method allowed the researchers to examine the aggregated peptide in a more natural, hydrated state. (alzforum.org)
  • The resulting diffraction patterns are an average of the different incident beam directions, which enhances the amount of Bragg spots/discs that can be recorded and averages over many different dynamical scattering conditions. (imaging-git.com)
  • One technique used to limit radiation damage is electron cryomicroscopy , in which the samples undergo cryofixation and imaging takes place at liquid nitrogen or even liquid helium temperatures. (wikipedia.org)
  • In friction tests against fixed and loose abrasive particles, the surface layers of hypereutectoid steel and hypoeutectic cast iron that were produced by electron-beam cladding and quenching had lower wear rates than mild steel after pack carburizing, quenching, and tempering. (chemweb.com)
  • The TEM diffraction patterns showed the PbS particles to be cubic in structure. (scielo.org.za)
  • Diffraction based methods, where changes in lattice distances of a material lead to varying Bragg angles, are very powerful to do so. (imaging-git.com)
  • Information about the strain of a sample region is contained in the Bragg angles of a diffraction pattern of this area. (imaging-git.com)
  • The second part is especially helpful for strain mapping with larger convergence angles, as the multiple scattering of electrons leads to contrasts within the Bragg discs, which reduces the quality of the auto-correlation and thus the measurement precision. (imaging-git.com)
  • When high-quality diffraction was observed for an untilted crystal, the crystal was then tilted to 60° to check the diffraction quality at higher tilt angles as crystal flatness and embedding could affect the diffraction quality at higher tilt ( Gonen, 2013 ). (elifesciences.org)