Spectrophotometric techniques by which the absorption or emmision spectra of radiation from atoms are produced and analyzed.
The art or process of comparing photometrically the relative intensities of the light in different parts of the spectrum.
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)
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.
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)
Solid dosage forms, of varying weight, size, and shape, which may be molded or compressed, and which contain a medicinal substance in pure or diluted form. (Dorland, 28th ed)
A metallic element of atomic number 30 and atomic weight 65.38. It is a necessary trace element in the diet, forming an essential part of many enzymes, and playing an important role in protein synthesis and in cell division. Zinc deficiency is associated with ANEMIA, short stature, HYPOGONADISM, impaired WOUND HEALING, and geophagia. It is known by the symbol Zn.
Determination, by measurement or comparison with a standard, of the correct value of each scale reading on a meter or other measuring instrument; or determination of the settings of a control device that correspond to particular values of voltage, current, frequency or other output.
A noninvasive technique that uses the differential absorption properties of hemoglobin and myoglobin to evaluate tissue oxygenation and indirectly can measure regional hemodynamics and blood flow. Near-infrared light (NIR) can propagate through tissues and at particular wavelengths is differentially absorbed by oxygenated vs. deoxygenated forms of hemoglobin and myoglobin. Illumination of intact tissue with NIR allows qualitative assessment of changes in the tissue concentration of these molecules. The analysis is also used to determine body composition.
An allotropic form of carbon that is used in pencils, as a lubricant, and in matches and explosives. It is obtained by mining and its dust can cause lung irritation.
A compound formed by the combination of hemoglobin and oxygen. It is a complex in which the oxygen is bound directly to the iron without causing a change from the ferrous to the ferric state.
The rate dynamics in chemical or physical systems.
The development and use of techniques and equipment to study or perform chemical reactions, with small quantities of materials, frequently less than a milligram or a milliliter.
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).
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)
Imaging the temperatures in a material, or in the body or an organ. Imaging is based on self-emanating infrared radiation (HEAT WAVES), or on changes in properties of the material or tissue that vary with temperature, such as ELASTICITY; MAGNETIC FIELD; or LUMINESCENCE.
A tricarbocyanine dye that is used diagnostically in liver function tests and to determine blood volume and cardiac output.
Liquid chromatographic techniques which feature high inlet pressures, high sensitivity, and high speed.
A heavy metal trace element with the atomic symbol Cu, atomic number 29, and atomic weight 63.55.
Chemicals and substances that impart color including soluble dyes and insoluble pigments. They are used in INKS; PAINTS; and as INDICATORS AND REAGENTS.
The visually perceived property of objects created by absorption or reflection of specific wavelengths of light.
A metallic element that has the atomic number 13, atomic symbol Al, and atomic weight 26.98.
A series of steps taken in order to conduct research.
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)
Substances used for the detection, identification, analysis, etc. of chemical, biological, or pathologic processes or conditions. Indicators are substances that change in physical appearance, e.g., color, at or approaching the endpoint of a chemical titration, e.g., on the passage between acidity and alkalinity. Reagents are substances used for the detection or determination of another substance by chemical or microscopical means, especially analysis. Types of reagents are precipitants, solvents, oxidizers, reducers, fluxes, and colorimetric reagents. (From Grant & Hackh's Chemical Dictionary, 5th ed, p301, p499)
Inorganic compounds that contain magnesium as an integral part of the molecule.
A bile pigment that is a degradation product of HEME.
Measurement of the intensity and quality of fluorescence.
A soft, grayish metal with poisonous salts; atomic number 82, atomic weight 207.19, symbol Pb. (Dorland, 28th)
Chromatography on thin layers of adsorbents rather than in columns. The adsorbent can be alumina, silica gel, silicates, charcoals, or cellulose. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)
A group of chemical elements that are needed in minute quantities for the proper growth, development, and physiology of an organism. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)
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.
Method for determining the circulating blood volume by introducing a known quantity of foreign substance into the blood and determining its concentration some minutes later when thorough mixing has occurred. From these two values the blood volume can be calculated by dividing the quantity of injected material by its concentration in the blood at the time of uniform mixing. Generally expressed as cubic centimeters or liters per kilogram of body weight.
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)
Any technique by which an unknown color is evaluated in terms of standard colors. The technique may be visual, photoelectric, or indirect by means of spectrophotometry. It is used in chemistry and physics. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)
Inorganic compounds that contain potassium as an integral part of the molecule.
The analysis of a chemical substance by inserting a sample into a carrier stream of reagent using a sample injection valve that propels the sample downstream where mixing occurs in a coiled tube, then passes into a flow-through detector and a recorder or other data handling device.
Dithionite. The dithionous acid ion and its salts.
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)
A trace element that plays a role in glucose metabolism. It has the atomic symbol Cr, atomic number 24, and atomic weight 52. According to the Fourth Annual Report on Carcinogens (NTP85-002,1985), chromium and some of its compounds have been listed as known carcinogens.
A strong corrosive acid that is commonly used as a laboratory reagent. It is formed by dissolving hydrogen chloride in water. GASTRIC ACID is the hydrochloric acid component of GASTRIC JUICE.
The measurement of the density of a material by measuring the amount of light or radiation passing through (or absorbed by) the material.
An inorganic compound that is used as a source of iodine in thyrotoxic crisis and in the preparation of thyrotoxic patients for thyroidectomy. (From Dorland, 27th ed)
Metals with high specific gravity, typically larger than 5. They have complex spectra, form colored salts and double salts, have a low electrode potential, are mainly amphoteric, yield weak bases and weak acids, and are oxidizing or reducing agents (From Grant & Hackh's Chemical Dictionary, 5th ed)
Method of analyzing chemicals using automation.
A metallic element that has the atomic symbol Mg, atomic number 12, and atomic weight 24.31. It is important for the activity of many enzymes, especially those involved in OXIDATIVE PHOSPHORYLATION.
The statistical reproducibility of measurements (often in a clinical context), including the testing of instrumentation or techniques to obtain reproducible results. The concept includes reproducibility of physiological measurements, which may be used to develop rules to assess probability or prognosis, or response to a stimulus; reproducibility of occurrence of a condition; and reproducibility of experimental results.
A silver metallic element that exists as a liquid at room temperature. It has the atomic symbol Hg (from hydrargyrum, liquid silver), atomic number 80, and atomic weight 200.59. Mercury is used in many industrial applications and its salts have been employed therapeutically as purgatives, antisyphilitics, disinfectants, and astringents. It can be absorbed through the skin and mucous membranes which leads to MERCURY POISONING. Because of its toxicity, the clinical use of mercury and mercurials is diminishing.
Tapping fluid from the subarachnoid space in the lumbar region, usually between the third and fourth lumbar vertebrae.
Inorganic or organic salts and esters of boric acid.
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.
The oxygen-carrying proteins of ERYTHROCYTES. They are found in all vertebrates and some invertebrates. The number of globin subunits in the hemoglobin quaternary structure differs between species. Structures range from monomeric to a variety of multimeric arrangements.
A basic science concerned with the composition, structure, and properties of matter; and the reactions that occur between substances and the associated energy exchange.
A metallic element with atomic symbol Fe, atomic number 26, and atomic weight 55.85. It is an essential constituent of HEMOGLOBINS; CYTOCHROMES; and IRON-BINDING PROTEINS. It plays a role in cellular redox reactions and in the transport of OXYGEN.
The composition, conformation, and properties of atoms and molecules, and their reaction and interaction processes.
A plant genus of the family ASTERACEAE. Other plants called broom include CYTISUS; SPARTIUM; and BROMUS.
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.
Relating to the size of solids.
Elements of limited time intervals, contributing to particular results or situations.
The chemical and physical integrity of a pharmaceutical product.
Carbon monoxide (CO). A poisonous colorless, odorless, tasteless gas. It combines with hemoglobin to form carboxyhemoglobin, which has no oxygen carrying capacity. The resultant oxygen deprivation causes headache, dizziness, decreased pulse and respiratory rates, unconsciousness, and death. (From Merck Index, 11th ed)
Proteins in the cerebrospinal fluid, normally albumin and globulin present in the ratio of 8 to 1. Increases in protein levels are of diagnostic value in neurological diseases. (Brain and Bannister's Clinical Neurology, 7th ed, p221)
A conjugated protein which is the oxygen-transporting pigment of muscle. It is made up of one globin polypeptide chain and one heme group.
Inorganic or organic compounds containing trivalent iron.
Tantalum. A rare metallic element, atomic number 73, atomic weight 180.948, symbol Ta. It is a noncorrosive and malleable metal that has been used for plates or disks to replace cranial defects, for wire sutures, and for making prosthetic devices. (Dorland, 28th ed)
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.
Theoretical representations that simulate the behavior or activity of chemical processes or phenomena; includes the use of mathematical equations, computers, and other electronic equipment.
An element with atomic symbol Cd, atomic number 48, and atomic weight 114. It is a metal and ingestion will lead to CADMIUM POISONING.
Fractionation of a vaporized sample as a consequence of partition between a mobile gaseous phase and a stationary phase held in a column. Two types are gas-solid chromatography, where the fixed phase is a solid, and gas-liquid, in which the stationary phase is a nonvolatile liquid supported on an inert solid matrix.
That portion of the electromagnetic spectrum in the visible, ultraviolet, and infrared range.
A trace element with atomic symbol Mn, atomic number 25, and atomic weight 54.94. It is concentrated in cell mitochondria, mostly in the pituitary gland, liver, pancreas, kidney, and bone, influences the synthesis of mucopolysaccharides, stimulates hepatic synthesis of cholesterol and fatty acids, and is a cofactor in many enzymes, including arginase and alkaline phosphatase in the liver. (From AMA Drug Evaluations Annual 1992, p2035)
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.
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.
A filament-like structure consisting of a shaft which projects to the surface of the SKIN from a root which is softer than the shaft and lodges in the cavity of a HAIR FOLLICLE. It is found on most surfaces of the body.
Red blood cells. Mature erythrocytes are non-nucleated, biconcave disks containing HEMOGLOBIN whose function is to transport OXYGEN.
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).
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)
Chemical compounds which pollute the water of rivers, streams, lakes, the sea, reservoirs, or other bodies of water.
Chemical analysis based on the phenomenon whereby light, passing through a medium with dispersed particles of a different refractive index from that of the medium, is attenuated in intensity by scattering. In turbidimetry, the intensity of light transmitted through the medium, the unscattered light, is measured. In nephelometry, the intensity of the scattered light is measured, usually, but not necessarily, at right angles to the incident light beam.
Concentration or quantity that is derived from the smallest measure that can be detected with reasonable certainty for a given analytical procedure.
A trace element with the atomic symbol Ni, atomic number 28, and atomic weight 58.69. It is a cofactor of the enzyme UREASE.
Platinum. A heavy, soft, whitish metal, resembling tin, atomic number 78, atomic weight 195.09, symbol Pt. (From Dorland, 28th ed) It is used in manufacturing equipment for laboratory and industrial use. It occurs as a black powder (platinum black) and as a spongy substance (spongy platinum) and may have been known in Pliny's time as "alutiae".
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)
Derivatives of the dimethylisoalloxazine (7,8-dimethylbenzo[g]pteridine-2,4(3H,10H)-dione) skeleton. Flavin derivatives serve an electron transfer function as ENZYME COFACTORS in FLAVOPROTEINS.
Domesticated bovine animals of the genus Bos, usually kept on a farm or ranch and used for the production of meat or dairy products or for heavy labor.
The 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)
An analytical method used in determining the identity of a chemical based on its mass using mass analyzers/mass spectrometers.
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.
Transparent, tasteless crystals found in nature as agate, amethyst, chalcedony, cristobalite, flint, sand, QUARTZ, and tridymite. The compound is insoluble in water or acids except hydrofluoric acid.
A chemical element having an atomic weight of 106.4, atomic number of 46, and the symbol Pd. It is a white, ductile metal resembling platinum, and following it in abundance and importance of applications. It is used in dentistry in the form of gold, silver, and copper alloys.
The physical or physiological processes by which substances, tissue, cells, etc. take up or take in other substances or energy.
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)
A basic element found in nearly all organized tissues. It is a member of the alkaline earth family of metals with the atomic symbol Ca, atomic number 20, and atomic weight 40. Calcium is the most abundant mineral in the body and combines with phosphorus to form calcium phosphate in the bones and teeth. It is essential for the normal functioning of nerves and muscles and plays a role in blood coagulation (as factor IV) and in many enzymatic processes.
Hemeproteins whose characteristic mode of action involves transfer of reducing equivalents which are associated with a reversible change in oxidation state of the prosthetic group. Formally, this redox change involves a single-electron, reversible equilibrium between the Fe(II) and Fe(III) states of the central iron atom (From Enzyme Nomenclature, 1992, p539). The various cytochrome subclasses are organized by the type of HEME and by the wavelength range of their reduced alpha-absorption bands.
Inorganic or organic oxy acids of sulfur which contain the RSO2(OH) radical.
The monitoring of the level of toxins, chemical pollutants, microbial contaminants, or other harmful substances in the environment (soil, air, and water), workplace, or in the bodies of people and animals present in that environment.
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.
Inorganic salts of HYDROGEN CYANIDE containing the -CN radical. The concept also includes isocyanides. It is distinguished from NITRILES, which denotes organic compounds containing the -CN radical.
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.
A compound consisting of dark green crystals or crystalline powder, having a bronze-like luster. Solutions in water or alcohol have a deep blue color. Methylene blue is used as a bacteriologic stain and as an indicator. It inhibits GUANYLATE CYCLASE, and has been used to treat cyanide poisoning and to lower levels of METHEMOGLOBIN.
Bleeding into the intracranial or spinal SUBARACHNOID SPACE, most resulting from INTRACRANIAL ANEURYSM rupture. It can occur after traumatic injuries (SUBARACHNOID HEMORRHAGE, TRAUMATIC). Clinical features include HEADACHE; NAUSEA; VOMITING, nuchal rigidity, variable neurological deficits and reduced mental status.
Particles consisting of aggregates of molecules held loosely together by secondary bonds. The surface of micelles are usually comprised of amphiphatic compounds that are oriented in a way that minimizes the energy of interaction between the micelle and its environment. Liquids that contain large numbers of suspended micelles are referred to as EMULSIONS.
An element with the atomic symbol Se, atomic number 34, and atomic weight 78.96. It is an essential micronutrient for mammals and other animals but is toxic in large amounts. Selenium protects intracellular structures against oxidative damage. It is an essential component of GLUTATHIONE PEROXIDASE.
Chemistry dealing with the composition and preparation of agents having PHARMACOLOGIC ACTIONS or diagnostic use.
A trace element that is a component of vitamin B12. It has the atomic symbol Co, atomic number 27, and atomic weight 58.93. It is used in nuclear weapons, alloys, and pigments. Deficiency in animals leads to anemia; its excess in humans can lead to erythrocytosis.
The separation of particles from a suspension by passage through a filter with very fine pores. In ultrafiltration the separation is accomplished by convective transport; in DIALYSIS separation relies instead upon differential diffusion. Ultrafiltration occurs naturally and is a laboratory procedure. Artificial ultrafiltration of the blood is referred to as HEMOFILTRATION or HEMODIAFILTRATION (if combined with HEMODIALYSIS).
The range or frequency distribution of a measurement in a population (of organisms, organs or things) that has not been selected for the presence of disease or abnormality.
The study of chemical changes resulting from electrical action and electrical activity resulting from chemical changes.
Inorganic or organic compounds that contain divalent iron.
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).
Insoluble polymers of TYROSINE derivatives found in and causing darkness in skin (SKIN PIGMENTATION), hair, and feathers providing protection against SUNBURN induced by SUNLIGHT. CAROTENES contribute yellow and red coloration.
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.
A system for verifying and maintaining a desired level of quality in a product or process by careful planning, use of proper equipment, continued inspection, and corrective action as required. (Random House Unabridged Dictionary, 2d ed)
A thiazide diuretic often considered the prototypical member of this class. It reduces the reabsorption of electrolytes from the renal tubules. This results in increased excretion of water and electrolytes, including sodium, potassium, chloride, and magnesium. It is used in the treatment of several disorders including edema, hypertension, diabetes insipidus, and hypoparathyroidism.
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)
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.
The color-furnishing portion of hemoglobin. It is found free in tissues and as the prosthetic group in many hemeproteins.
Volume of circulating BLOOD. It is the sum of the PLASMA VOLUME and ERYTHROCYTE VOLUME.
A basis of value established for the measure of quantity, weight, extent or quality, e.g. weight standards, standard solutions, methods, techniques, and procedures used in diagnosis and therapy.
A metallic element with the atomic symbol Mo, atomic number 42, and atomic weight 95.94. It is an essential trace element, being a component of the enzymes xanthine oxidase, aldehyde oxidase, and nitrate reductase. (From Dorland, 27th ed)
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)
Studies determining the effectiveness or value of processes, personnel, and equipment, or the material on conducting such studies. For drugs and devices, CLINICAL TRIALS AS TOPIC; DRUG EVALUATION; and DRUG EVALUATION, PRECLINICAL are available.
Presence of warmth or heat or a temperature notably higher than an accustomed norm.
The rate at which oxygen is used by a tissue; microliters of oxygen STPD used per milligram of tissue per hour; the rate at which oxygen enters the blood from alveolar gas, equal in the steady state to the consumption of oxygen by tissue metabolism throughout the body. (Stedman, 25th ed, p346)
The facilitation of a chemical reaction by material (catalyst) that is not consumed by the reaction.
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.
The process in which substances, either endogenous or exogenous, bind to proteins, peptides, enzymes, protein precursors, or allied compounds. Specific protein-binding measures are often used as assays in diagnostic assessments.
A chemical system that functions to control the levels of specific ions in solution. When the level of hydrogen ion in solution is controlled the system is called a pH buffer.
The property of emitting radiation while being irradiated. The radiation emitted is usually of longer wavelength than that incident or absorbed, e.g., a substance can be irradiated with invisible radiation and emit visible light. X-ray fluorescence is used in diagnosis.
Measuring instruments for determining the temperature of matter. Most thermometers used in the field of medicine are designed for measuring body temperature or for use in the clinical laboratory. (From UMDNS, 1999)
A colorless, flammable liquid used in the manufacture of FORMALDEHYDE and ACETIC ACID, in chemical synthesis, antifreeze, and as a solvent. Ingestion of methanol is toxic and may cause blindness.
Concentrated pharmaceutical preparations of plants obtained by removing active constituents with a suitable solvent, which is evaporated away, and adjusting the residue to a prescribed standard.
Polymers of ETHYLENE OXIDE and water, and their ethers. They vary in consistency from liquid to solid depending on the molecular weight indicated by a number following the name. They are used as SURFACTANTS, dispersing agents, solvents, ointment and suppository bases, vehicles, and tablet excipients. Some specific groups are NONOXYNOLS, OCTOXYNOLS, and POLOXAMERS.
Binary classification measures to assess test results. Sensitivity or recall rate is the proportion of true positives. Specificity is the probability of correctly determining the absence of a condition. (From Last, Dictionary of Epidemiology, 2d ed)
Naturally occurring or synthetic substances that inhibit or retard the oxidation of a substance to which it is added. They counteract the harmful and damaging effects of oxidation in animal tissues.
The species Oryctolagus cuniculus, in the family Leporidae, order LAGOMORPHA. Rabbits are born in burrows, furless, and with eyes and ears closed. In contrast with HARES, rabbits have 22 chromosome pairs.
The general name for a group of fat-soluble pigments found in green, yellow, and leafy vegetables, and yellow fruits. They are aliphatic hydrocarbons consisting of a polyisoprene backbone.
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)
Chinese herbal or plant extracts which are used as drugs to treat diseases or promote general well-being. The concept does not include synthesized compounds manufactured in China.
Large, hoofed mammals of the family EQUIDAE. Horses are active day and night with most of the day spent seeking and consuming food. Feeding peaks occur in the early morning and late afternoon, and there are several daily periods of rest.
The deductive study of shape, quantity, and dependence. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)
Electron microscopy in which the ELECTRONS or their reaction products that pass down through the specimen are imaged below the plane of the specimen.
Analytical technique for studying substances present at enzyme concentrations in single cells, in situ, by measuring light absorption. Light from a tungsten strip lamp or xenon arc dispersed by a grating monochromator illuminates the optical system of a microscope. The absorbance of light is measured (in nanometers) by comparing the difference between the image of the sample and a reference image.
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)
Electropositive chemical elements characterized by ductility, malleability, luster, and conductance of heat and electricity. They can replace the hydrogen of an acid and form bases with hydroxyl radicals. (Grant & Hackh's Chemical Dictionary, 5th ed)
Systems for the delivery of drugs to target sites of pharmacological actions. Technologies employed include those concerning drug preparation, route of administration, site targeting, metabolism, and toxicity.
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.
A microanalytical technique combining mass spectrometry and gas chromatography for the qualitative as well as quantitative determinations of compounds.
The parts of a macromolecule that directly participate in its specific combination with another molecule.
Nicotinamide adenine dinucleotide phosphate. A coenzyme composed of ribosylnicotinamide 5'-phosphate (NMN) coupled by pyrophosphate linkage to the 5'-phosphate adenosine 2',5'-bisphosphate. It serves as an electron carrier in a number of reactions, being alternately oxidized (NADP+) and reduced (NADPH). (Dorland, 27th ed)
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)
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.
A large lobed glandular organ in the abdomen of vertebrates that is responsible for detoxification, metabolism, synthesis and storage of various substances.
Positively charged atoms, radicals or groups of atoms which travel to the cathode or negative pole during electrolysis.
A shiny gray element with atomic symbol As, atomic number 33, and atomic weight 75. It occurs throughout the universe, mostly in the form of metallic arsenides. Most forms are toxic. According to the Fourth Annual Report on Carcinogens (NTP 85-002, 1985), arsenic and certain arsenic compounds have been listed as known carcinogens. (From Merck Index, 11th ed)
Compounds containing the -SH radical.
The dialdehyde of malonic acid.
Genetically identical individuals developed from brother and sister matings which have been carried out for twenty or more generations or by parent x offspring matings carried out with certain restrictions. This also includes animals with a long history of closed colony breeding.
Lasers with a semiconductor diode as the active medium. Diode lasers transform electric energy to light using the same principle as a light-emitting diode (LED), but with internal reflection capability, thus forming a resonator where a stimulated light can reflect back and forth, allowing only a certain wavelength to be emitted. The emission of a given device is determined by the active compound used (e.g., gallium arsenide crystals doped with aluminum or indium). Typical wavelengths are 810, 1,060 and 1,300 nm. (From UMDNS, 2005)
The products of chemical reactions that result in the addition of extraneous chemical groups to 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).
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.
Agents that emit light after excitation by light. The wave length of the emitted light is usually longer than that of the incident light. Fluorochromes are substances that cause fluorescence in other substances, i.e., dyes used to mark or label other compounds with fluorescent tags.
An oxidoreductase that catalyzes the reaction between superoxide anions and hydrogen to yield molecular oxygen and hydrogen peroxide. The enzyme protects the cell against dangerous levels of superoxide. EC
The process of cleaving a chemical compound by the addition of a molecule of water.
An oxidoreductase that catalyzes the conversion of HYDROGEN PEROXIDE to water and oxygen. It is present in many animal cells. A deficiency of this enzyme results in ACATALASIA.
A strain of albino rat used widely for experimental purposes because of its calmness and ease of handling. It was developed by the Sprague-Dawley Animal Company.
Chemicals that bind to and remove ions from solutions. Many chelating agents function through the formation of COORDINATION COMPLEXES with METALS.
A family of zinc-containing enzymes that catalyze the reversible hydration of carbon dioxide. They play an important role in the transport of CARBON DIOXIDE from the tissues to the LUNG. EC
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).
Inorganic salts of phosphoric acid.
The isotopic compound of hydrogen of mass 2 (deuterium) with oxygen. (From Grant & Hackh's Chemical Dictionary, 5th ed) It is used to study mechanisms and rates of chemical or nuclear reactions, as well as biological processes.
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.
A condensation product of riboflavin and adenosine diphosphate. The coenzyme of various aerobic dehydrogenases, e.g., D-amino acid oxidase and L-amino acid oxidase. (Lehninger, Principles of Biochemistry, 1982, p972)
An enzyme system that catalyzes the fixing of nitrogen in soil bacteria and blue-green algae (CYANOBACTERIA). EC
A barbituric acid derivative that acts as a nonselective central nervous system depressant. It potentiates GAMMA-AMINOBUTYRIC ACID action on GABA-A RECEPTORS, and modulates chloride currents through receptor channels. It also inhibits glutamate induced depolarizations.
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.
Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.
The presence in food of harmful, unpalatable, or otherwise objectionable foreign substances, e.g. chemicals, microorganisms or diluents, before, during, or after processing or storage.
Expanded structures, usually green, of vascular plants, characteristically consisting of a bladelike expansion attached to a stem, and functioning as the principal organ of photosynthesis and transpiration. (American Heritage Dictionary, 2d ed)
A disturbance in the prooxidant-antioxidant balance in favor of the former, leading to potential damage. Indicators of oxidative stress include damaged DNA bases, protein oxidation products, and lipid peroxidation products (Sies, Oxidative Stress, 1991, pxv-xvi).
A six carbon compound related to glucose. It is found naturally in citrus fruits and many vegetables. Ascorbic acid is an essential nutrient in human diets, and necessary to maintain connective tissue and bone. Its biologically active form, vitamin C, functions as a reducing agent and coenzyme in several metabolic pathways. Vitamin C is considered an antioxidant.
A strain of albino rat developed at the Wistar Institute that has spread widely at other institutions. This has markedly diluted the original strain.
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)
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.
Any of various animals that constitute the family Suidae and comprise stout-bodied, short-legged omnivorous mammals with thick skin, usually covered with coarse bristles, a rather long mobile snout, and small tail. Included are the genera Babyrousa, Phacochoerus (wart hogs), and Sus, the latter containing the domestic pig (see SUS SCROFA).
A strong oxidizing agent used in aqueous solution as a ripening agent, bleach, and topical anti-infective. It is relatively unstable and solutions deteriorate over time unless stabilized by the addition of acetanilide or similar organic materials.
A continuing periodic change in displacement with respect to a fixed reference. (McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)
Salts of nitrous acid or compounds containing the group NO2-. The inorganic nitrites of the type MNO2 (where M=metal) are all insoluble, except the alkali nitrites. The organic nitrites may be isomeric, but not identical with the corresponding nitro compounds. (Grant & Hackh's Chemical Dictionary, 5th ed)
Benzene derivatives that include one or more hydroxyl groups attached to the ring structure.
A coenzyme composed of ribosylnicotinamide 5'-diphosphate coupled to adenosine 5'-phosphate by pyrophosphate linkage. It is found widely in nature and is involved in numerous enzymatic reactions in which it serves as an electron carrier by being alternately oxidized (NAD+) and reduced (NADH). (Dorland, 27th ed)
Property of membranes and other structures to permit passage of light, heat, gases, liquids, metabolites, and mineral ions.
Single preparations containing two or more active agents, for the purpose of their concurrent administration as a fixed dose mixture.
A statistical technique that isolates and assesses the contributions of categorical independent variables to variation in the mean of a continuous dependent variable.
A chelating agent that sequesters a variety of polyvalent cations such as CALCIUM. It is used in pharmaceutical manufacturing and as a food additive.
A major protein in the BLOOD. It is important in maintaining the colloidal osmotic pressure and transporting large organic molecules.
The complete absence, or (loosely) the paucity, of gaseous or dissolved elemental oxygen in a given place or environment. (From Singleton & Sainsbury, Dictionary of Microbiology and Molecular Biology, 2d ed)
Electron-accepting molecules in chemical reactions in which electrons are transferred from one molecule to another (OXIDATION-REDUCTION).

UV irradiation of polycyclic aromatic hydrocarbons in ices: production of alcohols, quinones, and ethers. (1/2682)

Polycyclic aromatic hydrocarbons (PAHs) in water ice were exposed to ultraviolet (UV) radiation under astrophysical conditions, and the products were analyzed by infrared spectroscopy and mass spectrometry. Peripheral carbon atoms were oxidized, producing aromatic alcohols, ketones, and ethers, and reduced, producing partially hydrogenated aromatic hydrocarbons, molecules that account for the interstellar 3.4-micrometer emission feature. These classes of compounds are all present in carbonaceous meteorites. Hydrogen and deuterium atoms exchange readily between the PAHs and the ice, which may explain the deuterium enrichments found in certain meteoritic molecules. This work has important implications for extraterrestrial organics in biogenesis.  (+info)

Conformational changes generated in GroEL during ATP hydrolysis as seen by time-resolved infrared spectroscopy. (2/2682)

Changes in the vibrational spectrum of the chaperonin GroEL in the presence of ADP and ATP have been followed as a function of time using rapid scan Fourier transform infrared spectroscopy. The interaction of nucleotides with GroEL was triggered by the photochemical release of the ligands from their corresponding biologically inactive precursors (caged nucleotides; P3-1-(2-nitro)phenylethyl nucleotide). Binding of either ADP or ATP induced the appearance of small differential signals in the amide I band of the protein, sensitive to protein secondary structure, suggesting a subtle and localized change in protein conformation. Moreover, conformational changes associated with ATP hydrolysis were detected that differed markedly from those observed upon nucleotide binding. Both, high-amplitude absorbance changes and difference bands attributable to modifications in the interaction between oppositely charged residues were observed during ATP hydrolysis. Once this process had occurred, the protein relaxed to an ADP-like conformation. Our results suggest that the secondary structure as well as salt bridges of GroEL are modified during ATP hydrolysis, as compared with the ATP and ADP bound protein states.  (+info)

A new bile acid conjugate, ciliatocholic acid, from bovine gall bladder bile. (3/2682)

This study was carried out to investigate the occurrence of ciliatocholic acid in bovine gall bladder bile. Ciliatocholic acid was synthesized according to the method described by Bergstrom and Norman for the synthesis of taurocholic acid. Elemental analysis, melting point, and the infrared spectrum of this substance were determined. An isolation procedure for ciliatocholic acid was established by stepwise elution with an HCl-ethanol solvent system using a Dowex-1 anion exchange resin column chromatographic technique. Ciliatocholic acid amounting to 158 mug (as ciliatine) per 100 ml of gall bladder bile was found in the fraction eluted with 0.01 N HCl in 50% ethanol. This coumpound was purified by preparative thin-layer chromatography and confirmed to be ciliatocholic acid from the hydrolytic stability, phosphorus determination, and chromatographic behavior. Thus, bovine gall bladder bile contains a small amount of ciliatocholic acid.  (+info)

Infrared dichroism of the DNA-caffeine complex. A new method for determination of the ligand orientation. (4/2682)

Infrared linear dichroism (LD) measurements on films of the DNA-caffeine complex in terms of the relative humidity (r.h.) show two main effects. Firstly, there is an insertion of caffeine molecules into the DNA double helix (B form), as evidenced by a very strong parallel LD behaviour of the 745 cm-1 band due to the C-H out-of-plane deformation vibration of caffeine. Furthermore, a high r.h. values a modified B form occurs in the complex similar to the B form recently reported by BRAHMS and coworkers for DNA-polypeptide complexes. The reversible B-A transition of the DNA in dependence of the r.h. is not affected in general in the presence of caffeine.  (+info)

The two-dimensional IR nonlinear spectroscopy of a cyclic penta-peptide in relation to its three-dimensional structure. (5/2682)

A form of two-dimensional (2D) vibrational spectroscopy, which uses two ultrafast IR laser pulses, is used to examine the structure of a cyclic penta-peptide in solution. Spectrally resolved cross peaks occur in the off-diagonal region of the 2D IR spectrum of the amide I region, analogous to those in 2D NMR spectroscopy. These cross peaks measure the coupling between the different amide groups in the structure. Their intensities and polarizations relate directly to the three-dimensional structure of the peptide. With the help of a model coupling Hamiltonian, supplemented by density functional calculations, the spectra of this penta-peptide can be regenerated from the known solution phase structure. This 2D-IR measurement, with an intrinsic time resolution of less than 1 ps, could be used in all time regimes of interest in biology.  (+info)

High base pair opening rates in tracts of GC base pairs. (6/2682)

Sequence-dependent structural features of the DNA double helix have a strong influence on the base pair opening dynamics. Here we report a detailed study of the kinetics of base pair breathing in tracts of GC base pairs in DNA duplexes derived from 1H NMR measurements of the imino proton exchange rates upon titration with the exchange catalyst ammonia. In the limit of infinite exchange catalyst concentration, the exchange times of the guanine imino protons of the GC tracts extrapolate to much shorter base pair lifetimes than commonly observed for isolated GC base pairs. The base pair lifetimes in the GC tracts are below 5 ms for almost all of the base pairs. The unusually rapid base pair opening dynamics of GC tracts are in striking contrast to the behavior of AT tracts, where very long base pair lifetimes are observed. The implication of these findings for the structural principles governing spontaneous helix opening as well as the DNA-binding specificity of the cytosine-5-methyltransferases, where flipping of the cytosine base has been observed, are discussed.  (+info)

2-mercapto N-(azolyl)benzenesulfonamides. VI. Synthesis and anti-HIV activity of some new 2-mercapto-N-(1,2,4-triazol-3-yl)benzenesulfonamide derivatives containing the 1,2,4-triazole moiety fused with a variety of heteroaromatic rings. (7/2682)

A series of 2-mercapto-N-(1,2,4-triazol-3-yl)benzenesulfonamide derivatives containing the triazole moiety fused with a variety of heteroaromatic rings [XVI-XXVIII] was obtained by the reactions of 3-methylthio-1,4-2-benzodithiazine 1,1-dioxide derivatives [Ia-d] with 2-hydrazines [IIa-f]. Some of the intermediate 1,1-dioxide-1,4,2-benzodithiazin-3-ylhydrazines [III-XV] initially formed were also isolated. Preliminary screening data indicated that compounds [XVI-XIX and XXVII] were anti-HIV inactive, whereas other compounds showed a high [XXI and XXIII], fairly high [XXIII and XXVI] or moderate [XX, XXIV, XXV and XXVIII] activity. The compound [XXI] exhibited also high activity against ten selected HIV mutants.  (+info)

Synthesis, anti-HIV and anticancer activities of new 4-(2-mercaptobenzenesulfonyl)perhydro-1,2,4-triazin-3-ones. (8/2682)

Syntheses of N-(6-chloro-1,1-dioxo-7-R1-1,4,2-benzodithiazyn-3-yl)-N'-(2- hydroxyethyl)hydrazines (IIa-d], N-(6-chloro-1,1-dioxo-7-methyl-1,4,2-benzodithiazyn-3-yl)-N'-(2- chloroethyl)hydrazine [IV], 4-(4-chloro-5-R1-2-mercaptobenzenesulfonyl)perhydro-1,2,4-triaz in-3-ones [IIIa-d] and 5-chloro-4-methyl-2-(3-oxoperhydro-1,2,4-triazin-4- ylsulfonyl)phenylthioacetic acid [V] have been described. Preliminary screening data have indicated that compounds [IIIa-d] exhibit either a moderate or a high anti-HIV activity and a moderate anticancer activity in some human tumor cell lines.  (+info)

Ultraviolet-Visible-Near Infrared spectrophotometry (UV-Vis-NIR) is a non-destructive, non-contact optical characterization technique used to measure reflectance, absorbance, and transmittance of liquids and solids. It can be used to refine advanced optical modeling, or to make efficient, direct measurements of standard optical properties.. The optical properties, reflectance, transmittance, and absorbance, of a material are characterized with UV-Vis-NIR by analyzing the sample response as a function of wavelength. Covalents UV-Vis-NIR systems are considered dual-beam spectrometers, in which collimated beams of light are directed in two paths, one as a reference, and one towards the sample. As the wavelength of the applied beams is scanned through an entire spectral range, the reflected or transmitted light intensities are compared between the sample and the reference path. The difference between these intensities is plotted to produce the final UV-Vis-NIR spectrum, which captures the samples ...
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Does the Level of Chlamydia Serology Titre Correlate to the Degree of Tubal Disease at Laparoscopy? A Retrospective Controlled Study. B-Lines on Chest Ultrasound Predicts Elevated Left Ventricular Diastolic Pressures. Causes of Morbidity and Mortality of Wildlife Species Presented to a Wildlife Clinic in East Tennessee, USA, 2000-2011. Two-Dimensional Infrared Correlation Spectroscopy, Linear Two-Dimensional Infrared Spectroscopy and Non-Linear Two-Dimensional Infrared Spectroscopy Comparative Study on Malignant and Benign Human Cancer Cells and Tissues under Synchrotron Radiation with the Passage of Time. Investigation on Silver Ion Release from Wound Dressings In Vitro and In Vivo. On Physical Nature of the Long-Range Effect during the Crystal Growth through Boundary Layers. Physician and Patient Perspective to Weight Gain in Pregnancy. Compliance in the Duration of Administration of Anticancer Chemotherapy: Comparative Study of Two Different Administration Modalities (PVC versus IVAD). Wildlife
Plasmonic gold nanostars (NSts) demonstrate an enhanced electric field in their surrounding due to large number of hot spots on their surface resulting in a unique ability to confine light within a nanometric volume. We are demonstrating beneficial properties of NSts as signal enhancers for tissue and cell imaging using optical coherence tomography (OCT), microscopy, surface-enhanced vibration spectroscopy (SEVS), including surface-enhanced Raman scattering (SERS), and surface-enhanced infrared absorption spectroscopy (SEIRAS) with an attenuated total reflectance (ATR) and infrared reflection-absorption spectroscopy (IRRAS) configurations. Scattering ability of gold NSts with various sizes was investigated by OCT capillary imaging and light and confocal microscopy in vitro. The variation of NSts sizes allows one to shift plasmon resonance up to 1300 nm. The most intensive scattering signals were found from the largest NSts. NSts were applied in SEVS scenarios using plasmonic chip-based systems ...
Infrared absorption spectroscopy has proven to be one of the most powerful spectroscopic techniques available for the characterization of catalytic systems. Although the history of IR absorption spectroscopy in catalysis is long, the technique continues to provide key fundamental information about a variety Catalysis for Production of Renewable Energy
en] The structure, composition, and physico-chemical properties of lipid-protein complexes generated between dimyristoylphosphatidylcholine (DPMC) and the CNBr fragments of human apoA-I were studied. The fragments were separated by high performance liquid chromatography and purified on a reversed-phase column. The complexes with DMPC were isolated on a Superose column; their dimensions were obtained by gradient gel electrophoresis and by electron microscopy. The secondary structure of the protein in the complexes was studied both by circular dichroism and by attenuated total reflection infrared spectroscopy. The fragments 1 and 4 of apoA-I, containing, respectively, two and three amphipathic helices, recombined with the phospholipid to generate discoidal particles with sizes similar to that of apoA-I- and apoA-II-DMPC complexes. The infrared measurements indicated that in all complexes the apolipoprotein helical segments were oriented parallel to the phospholipid acyl chains and that the protein ...
Infrared spectroscopy is used extensively in the study of isolated biomolecules, but it becomes less useful as it is applied to systems of increasing complexity. Even if the individual vibrational bands can be resolved spectroscopically, their assignment becomes problematic when they are more closely spaced than can be determined using ab initio methods. We describe a method that helps to alleviate this difficulty by measuring the direction of the vibrational transition moment for each vibrational band. The molecules of interest (adenine and cytosine) are cooled to 0.37 kelvin in liquid helium nanodroplets and oriented in a large dc electric field. A polarized infrared laser is then used to determine the directions of the infrared transition moments relative to the permanent dipole moment. Comparisons with ab initio calculations provide detailed structural information, including experimental evidence for nonplanarity of adenine and three tautomers of cytosine. ...
The relation between mechanical film properties of various adsorbed protein layers at the air/water interface and intrinsic stability of the corresponding proteins is discussed. Mechanical film properties were determined by surface deformation in shear and dilation. In shear, fracture stress, σf, and fracture strain, γf, were determined, as well as the relaxation behavior after macroscopic fracture. The dilatational measurements were performed in a Langmuir trough equipped with an infra-red reflection absorption spectroscopy (IRRAS) accessory. During compression and relaxation of the surface, the surface pressure, Π, and adsorbed amount, Γ (determined from the IRRAS spectra), were determined simultaneously. In addition, IRRAS spectra revealed information on conformational changes in terms of secondary structure. Possible correlations between macroscopic film properties and intrinsic stability of the proteins were determined and discussed in terms of molecular dimensions of single proteins ...
Infiltration synthesis, the atomic-layer-deposition-based organic-inorganic material hybridization technique that enables unique hybrid composites with improved material properties and inorganic nanostructures replicated from polymer templates, is shown to be driven by the binding reaction between reactive chemical groups of polymers and perfusing vapor-phase material precursors. Here in this paper, we discover that residual solvent molecules from polymer processing can react with infiltrating material precursors to enable the infiltration synthesis of metal oxides in a nonreactive polymer. The systematic study, which combines in situ quartz crystal microgravimetry, polarization-modulated infrared reflection-absorption spectroscopy, X-ray photoelectron spectroscopy, and transmission electron microscopy, shows that the ZnO infiltration synthesis in nominally nonreactive SU-8 polymer is mediated by residual processing solvent cyclopentanone, a cyclic ketone whose Lewis-basic terminal carbonyl ...
The synthesis of two galactose-terminated alkanethiols with the structural formula X-OC2H5NHCO(CH2)15SH (X = 2,3,4,6-tetra-O-methyl-beta-D-Gal or beta-D-Gal) is described. Single-component and mixed self-assembled monolayers (SAMs) of the methylated and nonmethylated compounds were prepared on gold and subsequently characterized with ellipsometry, contact angle goniometry, and infrared reflection-absorption spectroscopy. Studies of the irreversible protein adsorption onto the SAMs using ex-situ ellipsometry revealed very low levels of fibrinogen and lysozyme adsorption onto mixed SAMs displaying advancing water contact angles between 24 degrees and 45 degrees and below 45 degrees , respectively. A monomethylated compound (X = 6-O-methyl-beta-D-Gal) was also synthesized and assembled on gold. This particular compound was found to possess wettability properties corresponding to the low adsorption regime of the mixed SAMs, and the results from the same set of fibrinogen and lysozyme adsorption experiments
Glycans at the surface of cellular membranes modulate biological activity via multivalent association with extracellular messengers. The lack of tuneable simplified models mimicking this dynamic environment complicates basic studies of these phenomena. We here present a series of mixed reversible self-assembled monolayers (rSAMs) that addresses this deficiency. Mixed rSAMs were prepared in water by simple immersion of a negatively charged surface in a mixture of sialic acid- and hydroxy-terminated benzamidine amphiphiles. Surface compositions derived from infrared reflection-absorption spectroscopy (IRAS) and film thickness information (atomic force microscopy, ellipsometry) suggest the latter to be statistically incorporated in the monolayer. These surfaces affinity for the lectin hemagglutinin revealed a strong dependence of the affinity on the presentation, density, and mobility of the sialic acid ligands. Hence, a spacer length of 4 ethylene glycol and a surface density of 15% resulted in a ...
Determining the chemical and structural modifications occurring within a protein during fundamental processes such as ligand or substrate binding is essential to building up a complete picture of biological function. Currently, significant unanswered questions relate to the way in which protein structural dynamics fit within the structure-function relationship and to the functional role, if any, of bound water molecules in the active site. Addressing these questions requires a multidisciplinary approach and complementary experimental techniques that, in combination, enhance our understanding of the complexities of protein chemistry. We exemplify this philosophy by applying both physical and biological approaches to investigate the active site chemistry that contributes to the inhibition of the Corynebacterium glutamicum catalase enzyme by nitric oxide. Ultrafast two-dimensional infrared spectroscopy (2D-IR) experiments exploit the NO ligand as a local probe of the active site molecular ...
Atmospheric corrosion, the most common form of metal corrosion, occurs within the interfacial region between a solid, and the surrounding atmosphere. In fact three phases and two interfaces are involved: the gas, a thin liquid layer, a solid, the gas/liquid and the liquid/solid interfaces. In this thesis, the vapor/liquid and liquid/metal interfaces have been studied by the in-situ techniques vibrational sum frequency spectroscopy (VSFS), and infrared reflection/absorption spectroscopy (IRAS). The main focus has been on characterization of the corrosive organic molecules formic acid, acetic acid, and acetaldehyde, at the two interfaces. Additionally, the headgroup of sodium dodecyl sulfate (SDS) has been examined at the air/water interface.. VSFS is an inherently surface sensitive laser spectroscopy technique, which provides vibrational spectra solely of the molecules residing at the surface of for example a liquid, despite the vast excess of the same molecules in the bulk. To obtain a ...
Infrared (IR) absorption spectroscopy directly probes the vibrational modes associate with the molecular bonds in a sample by measuring absorption in the mid-infrared spectral region, ~ 3 - 20 microns. IR spectroscopic measurements are thus intrinsically endowed with a level of chemical specificity and information content far exceeding that of most other optical measurement techniques.[1] Despite their potential, IR absorption measurements suffer not only from limited sensitivity, but are severely hindered by the strong, broad absorption of water that overlaps the bands of most organic compounds of interest. While recent surface enhanced infrared absorption (SEIRA) spectroscopy measurements have shown that IR resonant nanoantennas can be leveraged to dramatically increase sensitivity, [2-3] these have all been performed in dry environments and without time-resolution ...
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We are using ultrafast 2D IR vibrational echo spectroscopy and other multi-dimensional IR methods, which we have pioneered, to study dynamics of molecular complexes, water confined on nm lengths scales with a variety of topographies, molecules bound to surfaces, ionic liquids, and materials such as metal organic frameworks and porous silica. We can probe the dynamic structures these systems. The methods are somewhat akin to multidimensional NMR, but they probe molecular structural evolution in real time on the relevant fast time scales, eight to ten orders of magnitude faster than NMR. We are obtaining direct information on how nanoscopic confinement of water changes its properties, a topic of great importance in chemistry, biology, geology, and materials. For the first time, we are observing the motions of molecular bound to surfaces. In biological membranes, we are using the vibrational echo methods to study dynamics and the relationship among dynamics, structure, and function. We are also ...
Author: Wang, X. L. et al.; Genre: Journal Article; Published in Print: 2005; Title: Hydrolysis reaction analysis of L-alpha-distearoylphosphatidyleholine monolayer catalyzed by phospholipase A2 with polarization-modulated infrared reflection absorption spectroscopy
Fingerprint Dive into the research topics of Mid-IR pulse shaping for enhanced 2D IR spectroscopy. Together they form a unique fingerprint. ...
Zanni MT. Two-dimensional infrared spectroscopy measures the structural dynamics of a self-assembled film only one molecule thick. Proceedings of the National Academy of Sciences of the United States of America. 2016 ;113:4890-4891. ...
Kratochvil HT, Maj M, Matulef K, Annen AW, Ostmeyer J, Perozo E, Roux B, Valiyaveetil FI, Zanni MT. Probing the Effects of Gating on the Ion Occupancy of the K+ Channel Selectivity Filter Using Two-Dimensional Infrared Spectroscopy. Journal of the American Chemical Society. 2017 ;139:8837-8845. ...
Alperstein AM, Ostrander JS, Zhang TQO, Zanni MT. Amyloid found in human cataracts with two-dimensional infrared spectroscopy. Proceedings of the National Academy of Sciences of the United States of America. 2019 ;116:6602-6607. ...
TY - JOUR. T1 - An infrared study of crystallization in sodium-disilicate glasses containing iron oxides. AU - Park, J. W.. AU - Chen, Haydn. PY - 1980/1/1. Y1 - 1980/1/1. N2 - The infrared absorption spectra of sodium-disilicate glasses containing various amounts of Fe2O3 ([Na2O · 2 SiO2]1-x [Fe2O3]x, where x = 0.05, 0.1 and 0.2) were investigated in the wavenumber range from 200-2000 cm-1. The addition of Fe2O3 to the sodium-disilicate glass does not seem to introduce any new absorption band as compared with the spectrum of a pure sodium-disilicate glass; nevertheless, a general shift of the existing absorption bands toward lower wavenumbers is observed. The amount of shift is, in fact, proportional to the content of Fe2O3 in the glass. This observation is consistent with the recently proposed structural model for the bonding of Fe3+ ions in the iron-sodium-silicate glass system. Annealing of 20 mol% iron oxide glasses at 550 and 580°C produced an extra sharp infrared absorption peak at ...
Type 2 diabetes is one of the most prevalent diseases in the United States, inflicting more than 20.8 million people and expanding at epidemic rates in some are...
Vibrational and electronic transition dipole strengths are often good probes of molecular structures, especially in excitonically coupled systems of chromophores. One cannot determine transition dipole strengths using linear spectroscopy unless the concentration is known, which in many cases it is not. In this paper, we report a simple method for measuring transition dipole moments from linear absorption and 2D IR spectra that does not require knowledge of concentrations. Our method is tested on several model compounds and applied to the amide I band of a polypeptide in its random coil andα-helical conformation as modulated by the solution temperature. It is often difficult to confidently assign polypeptide and protein secondary structures to random coil or α-helix by linear spectroscopy alone, because they absorb in the same frequency range. We find that the transition dipole strength of the random coil state is 0.12 ± 0.013 D^2, which is similar to a single peptide unit, indicating that ...
There are six types of Cl. botulinum (Types A, B, C, D, E, and F). The differentiation between these types is based upon the antigenic structure of the toxin. Many strains of these various types have been isolated. In addition, a number of nontoxigenic type Elike strains have come to light. It would be of great value to have a rapid method of distinguishing between these strains, or of identifying the type of toxigenic culture. This thesis discusses an investigation into the possibilities of the use of infra-red in an approach to this problem. Smears of bacterial cells were prepared by scraping a small amount of growth from the agar surface of a petri plate, and dissolving it in a drop of water on the surface of a silver chloride disc. In the case of broth cultures, growth to be placed on the discs was first obtained by centrifugation. A second empty disc was then placed over the first with a bit of lens tissue under one edge to prevent the formation of interference fringes. The two discs were ...
We report a new approach to achieving super-resolution in point-scanning microscopy through polarization modulation for the first time, to the best of our knowledge. By modulating linearly polarized incident light, the emission extent of fluorescent dyes changes periodically, adding sparsity in each recording, which contributes to the super-resolution reconstruction. To recover the super-resolution result, a sparse penalty-based deconvolution method is implemented onto the polarization-modulated dataset subsequently. By simply inserting a vortex half-wave retarder into a typical confocal microscope, we obtain the super-resolution experimental results of both nuclear pore complex proteins and tubulins in vero cells, which evidence a sub-diffraction resolution of ...
In order to characterize the molecular structure and organization of the lipids, we performed attenuated total reflectance infrared (ATR-IR) spectroscopy measurements. Fig. 3a shows the absorption bands characteristic for the stretching vibrations of the lipid acyl chains for the lipid monolayer (black line) and for the lipid-graphene assembly (red line).28 The presence of these peaks confirms that the lipids remain underneath the graphene. Depending on whether the lipids are in contact or not with graphene, a shift in the peaks maxima is observed, characteristic for changes in the lipid conformation.29 Additionally, a shift was observed in the asymmetric methylene vibration (CH2) from ∼2915 to 2912 cm−1 and in the symmetric methylene vibration (CH2) from ∼2848 to 2844 cm−1, respectively. Furthermore the intensity of the asymmetric and symmetric CH2 bands of the lipid-graphene assembly increased. The observed shift is attributed to a change of the physical properties of the lipids film, ...
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X-irradiation of an Ar matrix doped with {\it p}-benzoquinone (PBQ) at 10 K leads to formation of the PBQ radical cation (PBQ$^{\bullet +}$) and radical anion (PBQ$^{\bullet -}$). The IR spectrum of PBQ$^{\bullet +}$ exhibits broad and dense absorption bands in the 2000 cm$^{-1}$ and higher energy region. Another characteristic of the spectrum is the presence of three intense peaks in the lower energy region. Equation-of-motion coupled-cluster calculations have been performed to analyze the spectrum with the quasi-diabatic model Hamiltonian technique. A spectral simulation based on the model Hamiltonian reproduces the observed IR spectrum very well, revealing that the electronic transition to the low-lying excited state, ${\tilde A}\,^2B_{2u} \leftarrow {\tilde X}\,^2B_{3g}$, is severely affected by nonadiabatic interaction of the two states, to which the aforementioned features are attributed. In particular, three $b_{1u}$ fundamental peaks for ${\tilde X}\,^2B_{3g}$ PBQ$^{\bullet +}$ gain ...
A new, full (nine)-dimensional potential energy surface and dipole moment surface to describe the NO{sup +}(H{sub 2}O) cluster is reported. The PES is based on fitting of roughly 32 000 CCSD(T)-F12/aug-cc-pVTZ electronic energies. The surface is a linear least-squares fit using a permutationally invariant basis with Morse-type variables. The PES is used in a Diffusion Monte Carlo study of the zero-point energy and wavefunction of the NO{sup +}(H{sub 2}O) and NO{sup +}(D{sub 2}O) complexes. Using the calculated ZPE the dissociation energies of the clusters are reported. Vibrational configuration interaction calculations of NO{sup +}(H{sub 2}O) and NO{sup +}(D{sub 2}O) using the MULTIMODE program are performed. The fundamental, a number of overtone, and combination states of the clusters are reported. The IR spectrum of the NO{sup +}(H{sub 2}O) cluster is calculated using 4, 5, 7, and 8 modes VSCF/CI calculations. The anharmonic, coupled vibrational calculations, and IR spectrum show very good ...
ZnGeP2(ZGP) single crystal with size of 24 mm in diameter and 70 mm in length was grown by a modified vertical Bridgman(VB) method in a three-zone furnace. The crystal was annealed in Zn Ge P2 powder at 600 ℃ for 500 h. X-ray diffraction(XRD), X-ray fluorescence(XRF) and Fourier transform infrared spectrophotometry(FTIR) were employed to characterize its properties. A ZGP optical parametric oscillator(ZGP-OPO) device was fabricated from the annealed sample. Laser experiment was carried out on the device. Tunable mid-infrared laser in the range of 3~5 μm was realized on the ZGP-OPO pumped by 2.1 μm, 7 k Hz laser. All the results indicate that our grown crystal is in good quality and can be used for nonlinear optical applications.
Researchers have succeeded in observing the forbidden infrared spectrum of a charged molecule for the first time. These extremely weak spectra offer perspectives for extremely precise measurements of molecular properties and may also contribute to the development of molecular clocks and quantum technology ...
Infrared absorption of some 3,4-disubstituted pyridines and pyridine 1-oxides Australian journal of chemistry CSIRO Publishing 0004-9425 10.1071/CH9650583
The spectral dependence of the infrared absorption cross section of As in Si near 0 K has been determined from infrared transmission measurements for three As concentrations (5.3, 8.4, and 15.9 × 1017 cm−3) in the impurity band regime. The results demonstrate some features of physical interest. With increasing As concentration, the lines associated with the intra-atomic transitions broaden asymmetrically, while the integral of the total absorption cross section over photon energy is conserved as required by the oscillator strength sum rule. It thus appears that the cross section for the intra-atomic transitions is conserved as the lines hybridize with the continuum. Comparison of our results with photoionization cross-sectional data suggests that the lines contribute to the cross section for photoionization through field and thermally assisted transitions when they are near the threshold for photoionization.. © 1989 Optical Society of America. Full Article , PDF Article ...
In this study, we provide the first Fourier-transform infrared absorption spectroscopy (FTIR) and Raman spectroscopy (RS) analysis of a vibrational fingerprint of erlotinib, a drug which is applied in non-small cell lung cancer therapy, in solid state and solution in different pH conditions. Additionally, the performed DFT theoretical calculations in vacuum and PCM models support the interpretation of vibrational spectra and give insight into an optimized spatial configuration of the investigated drug. The present considerations show vibrational structure of erlotinib and details of its molecular geometry. Furthermore, we discuss the pH condition where the protonated –NH|sup|+|/sup| and C=N|sup|+|/sup| forms occur and indicate the spectral changes characteristic for the erlotinib protonation. It is of great of importance to better understand biological activity of the drug and to develop new tyrosine kinase inhibitors.
A molecular mechanics (MM) force field-based empirical electrostatic potential map (MM map) for amide-I vibrations is developed with the aim of seeking a quick and reasonable approach to computing local mode parameters and their distributions in solution phase. Using N-methylacetamide (NMA) as a model compound, the instantaneous amide-I normal-mode parameters (transition frequency and dipole) obtained at the level of MM force fields are converted to solution phase values by a four-site potential scheme, but without the need for quantum mechanical frequency computations of solute-solvent clusters as are required in constructing ab initio-based electrostatic potential or field maps. The linear IR line shape of the amide-I mode in NMA obtained from the frequency-time correlation function on the basis of the MM map are found to be comparable to those from the ab initio-based maps. Our results show that the amide-I local mode parameters are largely determined by the solvated peptide structure rather ...
Infrared spectrophotometry (IR) uses similar instrumentation to UV-vis spectrophotometry but it uses a different light source (infrared frequencies of ~1011 to 1014 Hz). The instrumentation consists of an infrared beam that is split into two identical beams (reference beam and analytical beam).. The analytical beam passes through the sample so that molecular vibrational absorption can occur. The intensity of the two beams are compared over the range 2.5 µm to 16 µm and plotted as a function of wavenumber (the reciprocal of the wavelength in cm-1). ...
E. e. J + 1) for the R branch. The values of ν P , R at nonzero integral values of m are the transition wavenumbers of the allowed rotational lines associated with a given (v′,v″) band. A plot of ν P , R vs. m forms a parabola, usually called the Fortrat parabola. 7 presents the Fortrat parabola for the CN B - X (0,0) band. , 2006). We see that there are no lines with transition wavenumbers greater than that of the vertex of the parabola. The vertex can be seen in the spectrum as a sharp edge to the band and is called the band head. 35]. For example, vibrational transitions in homonuclear diatomic molecules can be observed in Raman spectroscopy, but not in infrared absorption or emission as discussed above. Further details about infrared absorption and Raman spectroscopy can be obtained from graduate spectroscopy textbooks, for example Bernath (2005), or specialist books. 4 Rotational structure A good first-order model of rotation is the rigid-rotor model, in which the internuclear ...
While peak height measurements were faster, they were still labor-intensive. There was one benefit to these methodologies: you were intimately familiar with the data. If anything was even a little off-including unexpected peaks, distortion of peak shapes, etc.-it was immediately noticeable and important because that meant that there was something unexpected in the sample, which could mean serious contamination. Part of the analysts role was to identify those contaminants, which usually meant multiple injections and cold trapping of the peak components as they left the column. In the past, infrared spectrophotometry was used to scan the trapped material. Today, people use mass spectrometry methods, e.g., liquid chromatography-mass spectrometry (LC-MS). Anything that could make those measurements easier and faster was welcomed into the lab (depending on your budget). Anything began with electronic integrators built around the Intel 4004 and 8008 chips[5][6] The integrators, connected to the ...
Kinetic IR spectroscopy was used to reveal β-sheet formation and water expulsion in the folding of single-chain monellin (SMN) composed of a five-stranded β-sheet and an α-helix. The time-resolved IR spectra between 100 μs and 10 s were analyzed based on two consecutive intermediates, I1 and I2, appearing within 100 μs and with a time constant of ≈100 ms, respectively. The initial unfolded state showed broad amide I′ corresponded to a fluctuating conformation. In contrast, I1 possessed a feature at 1,636 cm−1 for solvated helix and weak features assignable to turns, demonstrating the rapid formation of helix and turns. I2 possessed a line for solvated helix at 1,637 cm−1 and major and minor lines for β-sheet at 1,625 and 1,680 cm−1, respectively. The splitting of the major and minor lines is smaller than that of the native state, implying an incomplete formation of the β-sheet. Furthermore, both major and minor lines demonstrated a low-frequency shift compared to those of the ...
The study of membrane proteins (MPs) remains a major challenge in protein biochemistry mainly because of problems of protein aggregation and thermal instability in nonnative preparations of MPs in detergents, or native-like but insoluble preparations in liposomes. As a result, nonconventional surfactants with properties intermediate to lipids and detergents are becoming increasingly popular as alternative platforms for MPs (Bayburt and Sligar, 2002; Boldog et al., 2006; Park et al., 2007; Dalal et al., 2009; Popot, 2010). Discoidal lipoproteins, which include reconstituted high-density lipoprotein particles, nanodiscs, and nanoscale apolipoprotein-bound bilayers (NABBs), constitute a type of nonconventional platform that has enabled novel assays on MPs sequestered in a well-defined, soluble native-like lipid environment, such as single-particle imaging, surface plasmon resonance, nuclear magnetic resonance, and surface-enhanced infrared absorption spectroscopy (Banerjee et al., 2008; Das et al., ...
RequirePackage{filecontents} \begin{filecontents}{\jobname.bib} @Article{Adato2013, author = {Adato, Ronen and Altug, Hatice}, title = {In-situ ultra-sensitive infrared absorption spectroscopy of biomolecule interactions in real time with plasmonic nanoantennas}, journal = {Nat. Commun.}, year = {2013}, volume = {4}, } \end{filecontents} \documentclass{scrbook} \usepackage[nottoc,numbib]{tocbibind} \begin{document} \chapter{chapter1} text \cite{Adato2013} text \bibliographystyle{plain} % nature_style \bibliography{\jobname} % calls bib file created with filecontents! \end{document ...
A method for obtaining a high-contrast visible-light signal from infrared absorption in low-absorbance samples is described. This method is based on a beam-fanning optical limiter in photorefractive BaTiO3. The resulting signal is not linear but does exhibit an enhanced signal-to-background ratio that is 4 to 6 orders of magnitude better than that of conventional infrared absorption spectrophotometry in the shot-noise limit. A simple model for the beam-fanning, optical-limiter-based, pulsed-laser-excited photothermal spectroscopy detector is found to describe the experimental data adequately. This technique using photothermal spectroscopy detection may have advantages for rapid signal analysis and for two-dimensional visible imaging of infrared absorption.
The Near Infrared Reflectance Accessory (NIRA) is designed for diffuse reflectance measurements of light-scattering solids, liquids, and powders using the Frontier FT-NIR or FT-IR/NIR spectrometer.
The Near Infrared Reflectance Accessory (NIRA) is designed for diffuse reflectance measurements of light-scattering solids, liquids, and powders using the PerkinElmer Spectrum One NTS, Spectrum 100N, or Spectrum 400N FT-NR spectrometers.
TY - JOUR. T1 - SOFIA INFRARED SPECTROPHOTOMETRY of COMET C/2012 K1 (PAN-STARRS). AU - Woodward, Charles E.. AU - Kelley, Michael S P. AU - Harker, David E.. AU - Ryan, Erin L.. AU - Wooden, Diane H.. AU - Sitko, Michael L.. AU - Russell, Ray W.. AU - Reach, William T.. AU - Pater, Imke De. AU - Kolokolova, Ludmilla. AU - Gehrz, Robert D.. N1 - Publisher Copyright: © 2015. The American Astronomical Society. All rights reserved.. Copyright: Copyright 2018 Elsevier B.V., All rights reserved.. PY - 2015/8/20. Y1 - 2015/8/20. N2 - We present pre-perihelion infrared 8-31 μm spectrophotometric and imaging observations of comet C/2012 K1 (Pan-STARRS), a dynamically new Oort Cloud comet, conducted with NASAs Stratospheric Observatory for Infrared Astronomy facility (+FORCAST) in 2014 June. As a new comet (first inner solar system passage), the coma grain population may be extremely pristine, unencumbered by a rime and insufficiently irradiated by the Sun to carbonize its surface organics. The comet ...
Request Report Methodology @ https://www.persistencemarketresearch.co/methodology/26926 The content of the study subjects, includes a total of 15 chapters:. Chapter 1, to describe Vibrational Circular Dichroism Spectrometer product scope, market overview, market opportunities, market driving force and market risks.. Chapter 2, to profile the top manufacturers of Vibrational Circular Dichroism Spectrometer , with price, sales, revenue and global market share of Vibrational Circular Dichroism Spectrometer in 2017 and 2020.. Chapter 3, the Vibrational Circular Dichroism Spectrometer competitive situation, sales, revenue and global market share of top manufacturers are analyzed emphatically by landscape contrast.. Chapter 4, the Vibrational Circular Dichroism Spectrometer breakdown data are shown at the regional level, to show the sales, revenue and growth by regions, from 2014 to 2020.. Chapter 5, 6, 7, 8 and 9, to break the sales data at the country level, with sales, revenue and market share for ...
The 37-residue human islet amyloid polypeptide (hIAPP or amylin) self-assembles into fibers, the assembly of which has been associated with the disease mechanism of type II diabetes. Infrared spectroscopy in conjunction with isotope labeling is proving to be a powerful tool for studying the aggregation process of hIAPP and other amyloid forming proteins with residue specific structure and kinetic information, but the relationship between the spectroscopic observables and the structure is not fully established. We report a detailed analysis of the linear and 2D IR spectra of hIAPP fibers isotope labeled at seven different residue positions. The features of the 2D IR spectra, including the frequencies, linewidths, intensities, and polarization dependence of the diagonal and cross-peaks, rely heavily on the position of the isotope labeled residue. In order to understand how these measured parameters depend on fiber secondary and tertiary structure, we have simulated 1D and 2D IR spectra utilizing ...
A detailed study of the mechanism by which a dizinc catalyst copolymerizes cyclohexene oxide and carbon dioxide is presented. The catalyst, previously published by Williams et al. ( Angew. Chem. Int. Ed. 2009, 48, 931), shows high activity under just 1 bar pressure of CO2. This work applies in situ attenuated total reflectance infrared spectroscopy (ATR-FTIR) to study changes to the catalyst structure on reaction with cyclohexene oxide and, subsequently, with carbon dioxide. A computational investigation, using DFT with solvation corrections, is used to calculate the relative free energies for various transition states and intermediates in the cycle for alternating copolymerization catalyzed by this dinuclear complex. Two potentially competing side reactions, sequential epoxide enchainment and sequential carbon dioxide enchainment are also investigated. The two side-reactions are shown to be thermodynamically disfavored, rationalizing the high selectivity exhibited in experimental studies using ...
2010.12.13 The reseach article Noradrenaline and a Thiol Analogue on Gold Surfaces: an IRAS, XPS and NEXAFS Study. was published in Journal of Physical Chemistry C. Self-assembled monolayers and multilayers of a noradrenaline analogue (Nor-Pt) on gold substrates as well as multilayers of noradrenaline have been investigated by means of the molecular orientation, the molecule−surface interaction, the molecular composition and the functional group availability for further biointeraction processes, using X-ray photoelectron spectroscopy (XPS), infrared reflection−absorption spectroscopy (IRAS), and near-edge X-ray absorption fine structure (NEXAFS) spectroscopy ...
Exploration of attenuated total reflectance mid-infrared spectroscopy and multivariate calibration to measure immunoglobulin G in human sera
Diffuse-reflectance IR Fourier transform (DRIFT) spectroscopy was used to study in situ, the low-temp. (T |200 Deg) methanation of CO2 over Ru on TiO2 and on Al2O3 supports. For 3.8% Ru/TiO2, the reaction exhibits an activation energy (Ea) of 19 kcal/mol, is 0.43 +- 0.05 order in H2 concn., and essentially independent of CO2 concn. At 110 Deg, 40% of the available metal sites are occupied by CO (qCO = 0.4), a known methanation intermediate. In contrast to Ru/TiO2, Ru/Al2O3, despite having the same Ea and qCO = 0.2, is 15 times less active. Batch catalyst screening expts. showed no dependence of methanation activity on adsorbed CO(COa) formation rate (as modeled by HCOOH dehydration) or on qCO. In view of this, and the fact that CO dissocn. is structure-sensitive, heterogeneity in the active sites is invoked to reconcile the data. The high Ru dispersion on TiO2 is believed to contribute to the enhanced activity over this support. Adsorbed CO2 and H2 react, possibly at the metal-support interface, to form
TY - JOUR. T1 - Structures, vibrational absorption and vibrational circular dichroism spectra of L-alanine in aqueous solution: a density functional theory and RHF study. AU - Frimand, K.. AU - Bohr, H.. AU - Jalkanen, K.J.. AU - Suhai, S.. PY - 2000. Y1 - 2000. M3 - Article. VL - 255. SP - 165. EP - 194. JO - Chemical Physics. JF - Chemical Physics. SN - 0301-0104. ER - ...
The relative configuration of a key subunit of hemicalide, a recently isolated, highly bioactive marine natural product having potent antiproliferative activity against a panel of human cancer cell lines, was assigned by combining stereocontrolled synthesis of model substrates with NMR, IR, and vibrational circular dichroism (VCD) spectroscopy. The assignment of the absolute configuration of asymmetric carbon center C42 in two structurally complex epimeric substructures containing six stereocenters by VCD analysis illustrates the power and reliability of combining methods. ...
Nicu, V. and Neugebauer, J. and Wolff, S. and Baerends, E. 2008. A vibrational circular dichroism implementation within a Slater-type-orbital based density functional framework and its application to hexa- and hepta-helicenes. Theoretical Chemistry Accounts: Theory, Computation, and Modeling (Theoretica Chimica Acta). 119: pp. 245-263 ...
essentially a graph plotted with the infrared light absorbed on the Y-axis The compound is: The most appropriate spectroscopy for the identification of a nitrile group is: Compound I gives a strong infrared absorption at 1730 cm-1. Each of the following IR spectra (shown below) corresponds to one of the five isomers of C … By an intense pulse of radiation which contains a wide range of frequencies Why is UV-Vis Spectroscopy not like IR Spectroscopy UV/Vis Spectroscopy is where electromagnetic radiation in the UV to Visible range is shone at a sample to be analysed. What is the name given to the relaxation process due to an interaction between an excited nucleus and the magnetic fields caused by nuclei in molecules moving around in the sample? The solved questions answers in this Test: Spectroscopy- 3 quiz give you a good mix of easy questions and tough questions. This question is going to give you three isomeric compounds and three IR spectra. Multiple choice questions on principles, IR ...
2017-2022 Southeast Asia and Regional Vibrational Circular Dichroism Spectrometer Industry Production, Sales and Consumption Status and Prospects Professional Market Research Report
TY - JOUR. T1 - Application of infrared attenuated total reflection spectroscopy to in situ analysis of atheromatous plaques in aorta. AU - Nakamura, Atsushi. AU - Koga, Takehiro. AU - Fujimaki, Makoto. AU - Ohki, Yoshimichi. AU - Sota, Takayuki. AU - Lipinska-Kalita, Kristina. AU - Nagae, Tsuneyuki. AU - Ishimaru, Shin. AU - Aizawa, Katsuo. PY - 2000. Y1 - 2000. N2 - Ex vivo infrared attenuated total reflection (ATR) spectroscopic studies have been carried out to observe the accumulation of cholesterol ester in atheromatous plaques. It has been found that ATR spectra can be successfully obtained from the intima side of aorta and give the same information as the transmission spectra. This means, the ATR spectra include information about the chemical composition of atheromatous plaques together with the degree of eventual lesions. We have demonstrated that ATR microspectroscopic measurements can give images of atheromatous plaques distribution and enable in situ observation of the relative amount ...
The electrode potential dependence of the hydration layer on an n-Ge(100) surface was studied by a combination of in situ and operando electrochemical attenuated total reflection infrared (ATR-IR) spectroscopy and real space density functional theory (DFT) calculations. Constant-potential DFT calculations were coupled to a modified generalised Poisson-Boltzmann ion
TY - JOUR. T1 - The oxidation of hydroxylamine on Pt-, and Pd-modified Au electrodes in aqueous electrolytes. T2 - Electrochemical and in situ spectroscopic studies. AU - Jebaraj, Adriel Jebin Jacob. AU - De Godoi, Denis Ricardo Martins. AU - Scherson, Daniel Alberto. PY - 2013/3/15. Y1 - 2013/3/15. N2 - The electrooxidation of hydroxylamine, NH2OH, in 0.1 M phosphate buffer (PB, pH = 7) on Pt-, and Pd-modified Au electrodes prepared by galvanic displacement of underpotential deposited Cu, was investigated by electrochemical techniques and three and in situ vibrational probes, substrate-induced surface enhanced Raman scattering, SI-SERS, surface enhanced infrared absorption, SEIRAS, and Fourier transform infrared reflection-absorption, IRAS, spectroscopies. Analyses of the results obtained made it possible to identify at low overpotentials, solution phase (sol) and adsorbed (ads) nitric oxide, NO, as well as solution phase nitrous oxide, N2O. As the potential was increased, the peak(s) ascribed ...
Applications and Uncertainties Associated with Measurements Using Fourier Transform Infrared Spectrometry, Gas Chromatography-Mass Spectrometry and Selective Ion Electrode Method in Fire Suppression Tests
Milk, preheated at 82°C for 30 minutes, was heated to 146°C for four seconds (UHT-treated) and cooled to 5°C in a tubular heat exchanger. Immediately after heat treatment, 20 gallons of heated milk were vacuum distilled at 30°C in a semi-continuous, reduced pressure glass apparatus. Twenty gallons of non-heated milk were distilled in a similar manner to serve as a control. Continuous liquid-liquid ethyl ether extractions were employed to recover the compounds from the aqueous distillates. Gas chromatography, mass spectrometry, infrared spectrophotometry and odor confirmation were used to characterize the compounds in the flavor concentrates. A technique for collecting and transferring packed column gas chromatographic fractions to capillary columns for mass spectral analysis was developed. The following compounds were identified in UHT-treated milk (the underlined compounds appeared to result from the heat treatment): the C₃, ₄, ₅, ₇, ₈, ₉, ₁₀, ₁₁, ₁₃ n-methyl ...
Solvent-solute interactions influence the mechanisms of chemical reactions in solution, but the response of the solvent is often slower than the reactive event. Here, we report that exothermic reactions of fluorine (F) atoms in d3-acetonitrile and d2-dichloromethane involve efficient energy flow to vibrational motion of the deuterium fluoride (DF) product that competes with dissipation of the energy to the solvent bath, despite strong solvent coupling. Transient infrared absorption spectroscopy and molecular dynamics simulations show that after DF forms its first hydrogen bond on a subpicosecond time scale, DF vibrational relaxation and further solvent restructuring occur over more than 10 picoseconds. Characteristic dynamics of gas-phase F-atom reactions with hydrogen-containing molecules persist in polar organic solvents, and the spectral evolution of the DF products serves as a probe of solvent reorganization induced by a chemical reaction. ...
Time-resolved infrared absorption spectra of the C[triple bond]N bands of photoexcited TMABN and DMABN have been measured in non-polar hexane, polar aprotic THF and polar protic butanol with high temporal and spectral resolution (|0.5 ps and 5 cm(-1), respectively). In butanol, the intramolecular …
This article describes the application of multivariate statistical process control techniques to a series of mid-infrared spectra collected online from a styrene/ 2-ethylhexyl acrylate emulsion copolymerization process. Principal component analysis of the mid-infrared spectral data indicated that in situ monitoring of the complex copolymerization process was feasible in the spectral region of interest. It was also observed that projection to latent structures or partial least squares (PLS) could be used for the effective indirect online prediction of individual monomer conversions and copolymer compositions over a substantial range of process operating conditions. A combination of the developed PLS methodology with a mid-infrared attenuated total reflection probe proved to be an effective tool for the efficient online characterization of polymer quality, thereby overcoming the lack of robust online conversion and composition measuring devices. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci ...
Abstract: The aim of this study was to evaluate the viability of near infrared spectroscopy (NIRS) to detect the anomaly known as yellow stain on cork granulate. Detecting this anomaly is crucial to the cork granulate stopper industry, since it is associated with the presence of 2.4.6-Trichloroanisole (TCA), this compound having been identified as the main agent responsible for cork off-flavours. Samples for the NIRS spectra were prepared by mixing in different proportions cork granulate with high visual quality and cork granulate with yellow stain, obtaining 120 samples with 8 different percentages of yellow stain (0, 5, 10, 15, 25, 35, 50 and 100%). Two spectra per sample were collected using a Bruker MPA spectrophotometer and the partial least squares (PLS) method was used to obtain numerous equations. The best equation was obtained by utilizing the standard normal variate (SNV) spectral preprocessing, making use of only one specific part of the near infrared spectral range: 9400-4250 cm-1. This
This project will design and deliver a high accuracy monitor for the photo-chemically coupled pollutants nitric oxide, nitrogen dioxide and ozone using infrared absorption spectroscopy with quantum cascade (QC) lasers. The target molecules are monitored at air quality stations worldwide using instruments which require frequent calibration and are subject to significant chemical interferences (in the cases of NO2 and O3). This QC monitor will initially provide a portable measurement standard to calibrate the existing network and could eventually replace existing instruments. QC lasers are spectroscopically stable and can be operated near room temperature when in pulsed mode. This allows the design of compact, rugged, monitors which are also highly accurate. The main Phase 2 objectives are to complete the detailed design and construction of an instrument which can simultaneously measure all three species with high time resolution and high accuracy. This instrument will be delivered to NIST ...
Infrared reflection absorption and X-ray photoelectron spectroscopies are used to show that the process of carbon monoxide (CO) oxidation can occur on the surface of
Figure 2. B3LYP-D3(BJ)/def2-TZVP optimized geometry of the 2/(+)-1 and 2/(-)-1. Of interest to readers of this blog will be the DFT study of these complexes. The authors used three different well-known methods - B3LYP-D3(BJ)/def2-TZVP, M06-2x/def2-TZVP, and ωB97X-D/def2-TZVP - to compute structures and (most importantly) predict the vibrational frequencies. Interestingly, M06-2x/def2-TZVP and ωB97X-D/ def2-TZVP both failed to predict the vibrational frequency difference between the complexes with the two stereoisomers of α-pinene. However, B3LYP-D3(BJ)/def2-TZVP performed extremely well, with a mean average error (MAE) of only 1.9 cm-1 for the four different terpenes. Using this functional and the larger may-cc-pvtz basis set reduced the MAE to 1.5 cm-1 with the largest error of only 2.5 cm-1.. As the authors note, these complexes provide some fertile ground for further experimental and computational study and benchmarking.. ...
I.r. difference spectra are presented for 3-(indol-3-yl)acryloyl-, cinnamoyl-, 3-(5-methylthien-2-yl)acryloyl-, dehydrocinnamoyl- and dihydrocinnamoyl-chymotrypsins at low pH, where the acyl-enzymes are catalytically inactive. At least two absorption bands are seen in each case in the ester carbonyl stretching region of the spectrum. Cinnamoyl-chymotrypsin substituted at the carbonyl carbon atom with 13C was prepared. A difference spectrum in which 13C-substituted acyl-enzyme was subtracted from [12C]acyl-enzyme shows two bands in the ester carbonyl region and thus confirms the assignment of the features to the single ester carbonyl group. The frequencies of the ester carbonyl bands are interpreted in terms of differential hydrogen-bonding. In each case a lower-frequency relatively narrow band is assigned to a productive potentially reactive binding mode in which the carbonyl oxygen atom is inserted in the oxyanion hole of the enzyme active centre. The higher-frequency band, which is broader, is ...
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Philip J. Stephens was a theoretical chemist who brought to fruition two new forms of optical spectroscopy, using circularly polarized light, for the determination of electronic structure and molecular stereochemistry. The first was magnetic circular dichroism (MCD), the wavelength dependence of the differential absorption of left and right circularly polarized light induced by a magnetic field applied parallel to the light beam. Stephens established a methodology for extracting from MCD spectra the angular momentum characteristics of ground and excited electronic states and demonstrated applications to the assignment of the optical spectra of coordination complexes of transition metals and to metalloproteins. In the second half of his career Stephens led the field of vibrational circular dichroism (VCD), the measurement of the natural circular dichroism (CD) arising from the vibrational transitions of chiral molecules. He developed instrumental techniques to measure this weak dichroism over a ...
Near infrared spectroscopy offers the possibility of noninvasive and continuous bedside investigation of cerebral oxygenation in newborn infants. Using this technique we investigated the relationship between changes in cerebral oxygenation and hemodynamics, and changes in some physiological variables during blood transfusion in anaemic preterm infants.
The critical cooling rate for glass formation, Rc, and the crystallization kinetics of the compositions 1 2(100 - x)BaO- 1 2(100 - x)TiO2-xSiO2 with x = 20, 25, 30, 33.3 and 40 mol.% were studied using a thermal image furnace. Crystallization was studied under nonisothermal conditions and the data were analyzed using the Johnson-Mehl-Avrami (JMA) equation. The Rc and activation energy for crystallization both decrease with increasing silica content. Fresnoite, Ba2TiSi2O8, crystallized from all of the glasses when they were reheated. The infrared absorption spectra of the glasses and crystals show that they both contain (Si2O7) and square pyramidal (TiO5) groups.
In 1980 Harstein et al. [1] discovered that when a molecule was absorbed on metal surfaces, its infrared absorptions appeared more intense than what would be expected for traditional measurements. This effect was named Surface-Enhanced Infrared Absorption (SEIRA), to recall the analogy with SERS (Surface Enhanced Raman Spectroscopy), which was already known since the beginning of 70th [2],[3]. Many papers have been published trying to explain the enhancement mechanism which may be related to the result of the enhanced optical field at the surface of metal nano-particles when illuminated at the phonon resonance frequencies. In analogy with the interpretation of the SERS effect, Osawa [4] suggested that the total enhancement is produced by the combination of electromagnetic and chemical mechanisms. Moreover, it was noticed that the enhancement was significant for the first monolayer directly attached to the metal surface and decayed sharply within 5 nm from the surface. In addition, vibrational ...
The Fourier Transform Infrared Spectroscopy facility at the CEA Paris-Saclay is located at the Laboratory of Fundamental Mechanisms in Bioenergetics (UMR 9198). It provides the users with advanced FTIR spectrometry and responds to most of the needs of FTIR analyses.. The FTIR platform includes 4 spectrometers with many accessories: Transmission cell, ATR accessories, thermostatable liquid cells, cryostat for low temperature studies … It enables the analysis of various samples under different physical forms (see below). The laboratory has a specialization in FTIR difference spectroscopy, time-resolved FTIR, low temperature FTIR, and an expertise in the investigation of biochemical reactions and photo-induced reactions.. Equipment:. - Bruker Vertex 80V (under vacuum - to reduce noise and water vapor contamination; cryostat option; detectors: Bolometer, DTGS, MCT; spectral range between 100 and 6000 cm-1). It is interfaced with a pulsed laser Continuum Surelite+OPO (tunable between 440 and 670 ...
Results of protein secondary structure analysis are shown in Table 5. The protein internal structure α-helix and β-sheet were modeled and identified using secondary derivative function based on amide I component peaks centered at ca. 1,650 and 1,625 cm−1, respectively. We found the absorbance peak height and area intensities of protein amide I, amide II, α-helix and β-sheet height as well as their ratio in SBM, CM, and RSM. All parameters of protein secondary structure were significantly different (p,0.05) among SBM, CM, and RSM except amide I to amide II area ratio (p = 0.53). Amide I area, Amide I peak height, Amide II area, α-helix and β-sheet height in RSM were significantly lower than those in SBM and in CM (p,0.05). Reports showed that amide I region mainly resulted from C=O stretching vibration and C-N stretching vibration. The region of amide II was primarily associated with NH in-plane bending and C-N stretching, also related to C=O stretching, C-C stretching and N-C stretching ...
We believe in loving Anything you do, and undertaking Anything you really like. Je Ballet is often a designer of premium ballet gear. Our flagship solution could be the Turning Pointe, a next level coaching Device for dancers of all types. Designed on the need to deliver the dance Neighborhood with strategies to further improve, we operate with dancers across the globe to produce items that are not merely wonderful, but also extremely functional ...
Infrared wavelengths exist on the invisible spectrum of light and cannot be seen with the human eye, but are experienced kinetically as heat. The infrared spectrum of light penetrates deeply into the epidermis and therefore fully engages the cellular and molecular network. As the rays of infrared light burrow into the epidermis, the largest human organ, they heat the body up from the inside out. The body responds to both infrared heat therapy and light to reduce inflammation by increasing circulation. Improved blood circulation intrinsically flushes inflammation out of the joints by creating a current of hyperoxygenated hemoglobin through the affected areas of the body.. When the body is exposed to the healing rays of the infrared spectrum, the living anatomy of the human body invites the light into its network system to create a domino effect on the cellular activity to decrease inflammation.. As the infrared light seeps beyond the initial membrane of the skin to penetrate into the soft tissue ...
The real problem with a small group of people who control these technologies unwatched by the public eye is its potential for great abuse. For example, we can never fully solve any accident or crime and know whether it was an EEG heterodyned crime or a regular one. Princess Dianas driver could have been EEG heterodyned and made to crash into the barrier. John Hinckley could have been made to believe that only by shooting President Reagan could he get Jody Foster to love him. I met a Colonel in the Air Force who test flew the new exotic airplanes and who was menticized after discovery of all sorts of corruption with Halliburton defense contracts. False memories were implanted in him and he was made to believe he was married and had a kid with some music star for two years. Clearly the capability exists to create Manchurian Candidates like John Hinckley. JFK junior could have been made to misinterpret the horizon or his aircraft instruments to malfunction.. All these events could have been ...
Financial support by Région Provence-Alpes-Côte dAzur, Programme Interdisciplinaire Energie CNRS and ANR Bioénergie. We thank Dr. A. Ronda and NanoTecMat technological facility for atomic force microscopy (AFM) experiments, Dr. S. Canaan and S. Robert for TLC experiments, and M. Bauzan for growing the bacteria. PM-IRRA=polarization modulation infrared reflection adsorption. ...
1. Abe, H., T. Kusama, S. Kawano, and M. Iwamoto, 1995. Non-destructive determination of protein content in a single kernel of wheat and soybean by near infrared spectroscopy. In: A.M.C. Davies & P. Williams (Eds.), Near Infrared Spectroscopy: the Future Waves, pp. 457-461. NIR Publications, Chichester, UK.. 2. Dyer, D.J., and P. Feng, 1995. Near infrared applications in the development of genetically altered grains. In: A.M.C. Davies & P. Williams (Eds.), Near Infrared Spectroscopy: the Future Waves, pp. 490-493. NIR Publications, Chichester, UK.. 3. Orman, B.A., and R.A. Schumann, Jr., 1992. Nondestructive single-kernel oil determination of maize by near-infrared transmission spectroscopy. Journal of the American Oil Chemists Society 69:1036-1038.. 4. Patrick, B.E., and G.D. Jolliff, 1997. Nondestructive single-seed oil determination of meadowfoam by near-infrared transmission spectroscopy. Journal of the American Oil Chemists Society 74:273-276.. 5. R bbelen, G., 1990. Mutation breeding for ...
Fourier transform infrared spectroscopy (FTIR spectroscopy) covers a wide range of chemical applications, especially for polymers and organic compounds. Learn more about the basics of this chemical analysis technique.
A single photon detector is the key device needed to build highly sensitive instruments for measuring spectra. For the past 30 years, scientists have made steady progress increasing the efficiency and sensitivity of visible and ultraviolet photon detectors while methods for detecting elusive single photons in the near-infrared (NIR) range have faltered. The methods presently in use are too static-laden, inefficient and slow, or depend on superconducting detectors, which require expensive, low-temperature operating environments. The NIST group, Lijun Ma, Oliver Slattery and Xiao Tang, wanted to develop a way to use existing detectors such as avalanche photodiode detectors (APD), which work very well for detecting visible light and are widely used, but are ineffective for the detection of NIR.. Their approach was to adapt a technique developed two years ago at NIST for quantum cryptography that up converts photons at one frequency to a higher frequency. The technique promotes the infrared ...
Pardo, Leonardo; Sepulcre Sánchez, Francesc; Cladera Cerdà, Josep Bartomeu; Duñach, Mireia; Labarta, A.; Tejada, J.; Padrós Morell, Esteve ...
The IUCr is a scientific union serving the interests of crystallographers and other scientists employing crystallographic methods ...
I am getting tired of the Greg and OP show, so I want to address some of the comments from perspective. I first want to warn you about learning science from fiction writers! It is true that CO2 makes up a small percentage of our atmosphere, much less than 1%. It is 4th on the list, behind N2, O2 and Ar. However, none of these three major constituents absorb in the infrared, while CO2 is a very strong absorber. This IR absorption is what holds in the heat and causes the warming. Imagine your football field is a tank of extremely pure and absolutely transparent water. Now add a very small bit of highly-concentrated red dye. Even a little bit would make a big difference to your ability to see through the water. CO2 is basically a dye in the infrared spectrum, absorbing certain wavelengths that would otherwise pass out of the atmosphere and back into space. Man-made sources of CO2 are presently contributing less about 5% of the total CO2 into the atmosphere, but that is enough to tip the balance ...
Twardowski, J.; Nowak, I.; Stufkens, D.J.; Snoeck, T.L., 1984: Raman and ir studies of homogeneous forms of acid phosphatase ec from rat liver
... and emittance of materials at infrared wavelengths. He is an expert in infrared spectrophotometry and integrating sphere design ... "Fourier transform infrared spectrophotometry (FTIS) facility". NIST. 2019-10-15. Retrieved 2020-11-01. Hanssen, Leonard; Kaplan ... He manages the Fourier Transform Infrared Spectrophotometry (FTIS) Facility, which was developed to take low uncertainty ... FTIS employs a Fourier-transform infrared spectrophotometer and custom integrating sphere to measure absolute infrared ...
March 2002). "Near-Infrared Spectrophotometry of Phobos and Deimos". Icarus. 156 (1): 64-75. Bibcode:2002Icar..156...64R. doi: ... Infrared spectra show that it has carbon-rich material found in carbonaceous chondrites. Instead, its composition shows ... "A Study of Near-Infrared Hyperspectral Imaging of Martian Moons by NIRS4/MACROMEGA onboard MMX Spacecraft" (PDF). Lunar and ... Observations of Phobos in the thermal infrared suggest a composition containing mainly phyllosilicates, which are well known ...
Spectrophotometry, infrared spectroscopy Absorption spectra Table 1. Supersaturation measurement methods (Profos, 1987).[11] ... This can be determined using satellite data from the Atmospheric Infrared Sounder.[23] Evidence of supersaturation in the ... "The Global Distribution of Supersaturation in the Upper Troposphere from the Atmospheric Infrared Sounder". Journal of Climate ...
"Infrared photometry and spectrophotometry of Nova Aquilae 1982". Monthly Notices of the Royal Astronomical Society. 207: 897- ... The fading nova was also observed from the ground in the near and mid infrared by Bode et al., who concluded that either dust ...
Compared to previous distillation methods, infrared spectrophotometry offered a tremendous time savings, reducing testing time ... and Robert Brattain assembled a team to study the problem using infrared spectrophotometry. Another team at Shell used chemical ... It included infrared spectroscopy researchers at Cambridge (G.B.B.M. Sutherland), at Oxford (Harold Warris Thompson), and ... Companies such as Perkin-Elmer whose work was not as restricted, were able to publish about their work in infrared spectroscopy ...
"Visible to Thermal-Infrared Spectrophotometry of a Possible Inactive Cometary Nucleus". Icarus. 153 (2): 332-337. Bibcode: ... October 2011). "Asteroid Catalog Using Akari: AKARI/IRC Mid-Infrared Asteroid Survey". Publications of the Astronomical Society ... Varuna in the near-infrared". Astronomy & Astrophysics. 562: A85. arXiv:1401.5962. Bibcode:2014A&A...562A..85L. doi:10.1051/ ... diameter and composition of near-Earth asteroids via near-infrared spectroscopy". Icarus. 219 (1): 382-392. Bibcode:2012Icar.. ...
October 2001). "Visible to Thermal-Infrared Spectrophotometry of a Possible Inactive Cometary Nucleus". Icarus. 153 (2): 332- ...
July 2013). "ICNIRP guidelines on limits of exposure to incoherent visible and infrared radiation" (PDF). Health Physics. 105 ( ... Plant Physiology Online: Principles of Spectrophotometry v t e. ...
"Hubble Space Telescope Absolute Spectrophotometry of Vega from the Far-Ultraviolet to the Infrared". The Astronomical Journal. ... The Infrared Astronomical Satellite (IRAS) discovered an excess of infrared radiation coming from the star, and this was ... One of the early results from the Infrared Astronomy Satellite (IRAS) was the discovery of excess infrared flux coming from ... Stars that display an infrared excess due to dust emission are termed Vega-like stars. In 2021, a candidate ultra-hot Neptune ...
Harris, Alan W.; Davies, John K.; Green, Simon F. (October 1998). "Thermal Infrared Spectrophotometry of the Near-Earth ... October 2011). "Asteroid Catalog Using Akari: AKARI/IRC Mid-Infrared Asteroid Survey". Publications of the Astronomical Society ... "Keck observations of near-Earth asteroids in the thermal infrared". Icarus. 166 (1): 116-130. Bibcode:2003Icar..166..116D. doi: ...
Spectrophotometry in infrared light is mainly used to study structure of substances, as given groups give absorption at defined ... This makes it possible also to study the isotopic composition of a sample with infrared spectrophotometry. Atomic absorption ... The infrared spectrum typically has very narrow absorption lines, which makes them unsuited for quantitative analysis but gives ... Therefore, infrared spectroscopy is either performed in the gaseous phase (for volatile substances) or with the substances ...
Gases in the cabin can be tested using gas chromatography, mass spectrometry and infra-red spectrophotometry. Samples of air ...
He credited the Corona Lab program with the establishment of the atomic wavelength standard in the infrared. Humphreys attended ... His inventions significantly advanced the techniques of radiometry and spectrophotometry. ... Co-authored Rao, K. Narahari; Curtis J. Humphreys; D.H. Rank, "Wavelength Standards in the Infrared", Academic Press, 1966. ... Standards 1953, 50, 1. "Interferometric measurement of wavelengths of infrared atomic emission lines in the extraphotographic ...
"Neutron-capture element abundances in the planetary nebula NGC 5315 from deep optical and near-infrared spectrophotometry". ...
The transmission extends from UV light to mid-infrared, ranging from 250 to 5,000 nm. Sapphire can withstand the extreme ... Spectrophotometry Handbooks Standard Practice for Describing and Measuring Performance of Ultraviolet, Visible, and Near- ...
In 2011 a new bus station, the design of which was inspired by the infrared experiment of William Herschel, was built in the ... Herschel pioneered the use of astronomical spectrophotometry, using prisms and temperature measuring equipment to measure the ... The shape of Slough Bus Station, built in 2011, was inspired by Herschel's infrared experiment. Herschel Grammar School, Slough ... In the course of these investigations, Herschel discovered infrared radiation. Other work included an improved determination of ...
The NIFA administers cobalt-60 radiation source, Laser absorption spectrometer and Atomic Absorption Spectrophotometry, Near- ... infrared spectrometer and Ultraviolet-visible spectroscopy. A library was opened in 1990, and recently, the institute has ...
Ultraviolet fluorescence and infrared analysis are used to detect repairs or earlier painting present on canvasses. Atomic ... Absorption Spectrophotometry (AAS) and Inductively Coupled Plasma Mass Spectrometry (ICP-MS) are used to detect anomalies in ...
He developed a device specific to this measure that he called a Near Infrared Spectrophotometry Hemencephalography system, ... Both approaches to hemoencephalography, near infrared and passive infrared, are indirect measures of neural activity based on ... PIR uses a sensor similar to the NIR sensor to detect light from a narrow band of the infrared spectrum that corresponds to the ... Hershel Toomim, near infrared hemoencephalography measures changes in the local oxygenation level of the blood. Similar to ...
... is a pioneer in the development of instruments for infrared spectrophotometry and non-dispersive infrared analysis. Two of his ... Liston-Becker was one of a number of companies seeking to develop instruments to measure CO 2 using infrared absorption. Soon ... In 1950, Morris Folb and Max Liston formed the Liston-Folb company, focusing on the development of nondispersive infrared ... Wilks, Paul A. (2013). "The origins of commercial infrared spectrometers". In Stock, John T.; Orna, Mary Virginia (eds.). The ...
Infrared analysis of pharmaceuticals. 2. A study of the cinchona alkaloids in potassium bromide disks. J Am Pharm Assoc Am ... Spectrophotometry and crystallography studies were conducted independently by three teams, including scientists from MIT. The ... Infrared, ultraviolet, and visible absorption spectra of some USP and NF reference standards and their derivatives. Association ... Infrared analysis of pharmaceuticals. 1. Application of the potassium bromide disk technique to some steroids, alkaloids, ...
IR spectrophotometryEdit. Main article: Infrared spectroscopy. Spectrophotometers designed for the infrared region are quite ... "Spectrophotometry". NIST. Retrieved Dec 23, 2018.. *^ a b c d e f g h i j Ninfa AJ, Ballou DP, Benore M (2010). Fundamental ... "Spectrophotometry Applications and Fundamentals". www.mt.com. Mettler-Toledo International Inc. Retrieved Jul 4, 2018.. ... UV-visible spectrophotometryEdit. Main article: Ultraviolet-visible spectroscopy. Most spectrophotometers are used in the UV ...
Rivkin A. S.; et al. (1. 3. 2002). "Near-Infrared Spectrophotometry of Phobos and Deimos". Icarus 156 (1): 64. Bibcode:2002Icar ... "Compositional Interpretation of PFS/MEx and TES/MGS Thermal Infrared Spectra of Phobos". European Planetary Science Congress ...
... micrometers Ultraviolet and infrared energy sources Photometric colour determination equipment X-ray fluorescence and spectro-photometry ...
The demand for synthetic rubber caused Beckman Instruments to develop infrared spectrophotometers. Infrared spectrophotometers ... Beckman, A. O.; Gallaway, W. S.; Kaye, W.; Ulrich, W. F. (March 1977). "History of spectrophotometry at Beckman Instruments, ... since by 1954 Beckman Instruments was marketing a separate infrared spectrophotometer. Beckman developed the IR-1 infrared ... The DK was named for Wilbur I. Kaye, who developed it by modifying the DU to expand its range into the near-infrared. He did ...
Much of his work dealt with infrared spectrophotometry, but he also became familiar with NMR, which was being used in nuclear ... He was active in researching molecular and solid-state structure, using infrared (IR) and radio frequency spectroscopy, and ...
Two such signs, in the near-infrared, extending somewhat into visible light, are in common use. Water, hydroxyl, and some ... Feierberg, M; Lebofsky, L; Tholen, D (1985). "The nature of C-class asteroids from 3u spectrophotometry". Icarus. 63 (2): 191. ... Hayabusa 1's NIRS (Near-Infrared Spectrometer) design was then shifted from its maximum wavelength of 2.1 um, to Hayabusa 2's ... Lesser signs of water include ultraviolet/visible (OH 0-0, 308 Å), mid-infrared, and longer. The hydrogen nucleus- one proton- ...
2012), "Fundamental Parameters and Infrared Excesses of Hipparcos Stars", Monthly Notices of the Royal Astronomical Society, ... September 2002), "Metallicity Determinations from Ultraviolet-Visual Spectrophotometry. I. The Test Sample", The Astrophysical ...
Infrared" by people in Harvard Catalyst Profiles by year, and whether "Spectrophotometry, Infrared" was a major or minor topic ... Spectrophotometry in the infrared region, usually for the purpose of chemical analysis through measurement of absorption ... "Spectrophotometry, Infrared" is a descriptor in the National Library of Medicines controlled vocabulary thesaurus, MeSH ( ... Below are the most recent publications written about "Spectrophotometry, Infrared" by people in Profiles. ...
A calibration curve for infrared absorptiometry of nitrogen in silicon at 963 cm-1 was obtained by the use of charged particle ... Determination of Nitrite and Nitrogen Dioxide by Spectrophotometry After Solid Phase Extraction. Parmar, Prachi; Mathew, ... this relation was found to give underestimated nitrogen concentration suggesting the existence of infrared insensitive nitrogen ...
"Analytical infrared spectrophotometry of the sulfur oxides." (1952) Masters Thesis, Rice University. http://hdl.handle.net/ ...
Near-Infrared Spectrophotometry with the Beckman Model DU Spectrophotometer Wilbur Kaye Author Information Author Affiliations ... Wilbur Kaye, "Near-Infrared Spectrophotometry with the Beckman Model DU Spectrophotometer," J. Opt. Soc. Am. 41, 277-277 (1951 ...
A. L. Schoen, "A Photographic Method of Spectrophotometry in the Red and Infrared*," J. Opt. Soc. Am. 14, 179-186 (1927) ... A Photographic Method of Spectrophotometry in the Red and Infrared A. L. Schoen ... A New Method for Photographic Spectrophotometry* Loyd A. Jones. J. Opt. Soc. Am. 10(5) 561-572 (1925) ...
From spectrophotometry to multispectral imaging of ore minerals in visible and near infrared (VNIR) microscopy ... From spectrophotometry to multispectral imaging of ore minerals in visible and near infrared (VNIR) microscopy. ... From spectrophotometry to multispectral imaging of ore minerals in visible and near infrared (VNIR) microscopy. In: "9th ... needs a more in-depth investigation as well as the possibility to extend both imaging and spectroscopy into the near infrared ...
In this work, a study of the molecular structure and the infrared and Raman spectra of this chemical is presented. Theoretical ...
IR spectrophotometry[edit]. Main article: Infrared spectroscopy. Spectrophotometers designed for the infrared region are quite ... Although spectrophotometry is most commonly applied to ultraviolet, visible, and infrared radiation, modern spectrophotometers ... "Spectrophotometry". NIST. Retrieved Dec 23, 2018.. *^ a b c d e f g h i j Ninfa AJ, Ballou DP, Benore M (2010). Fundamental ... UV-visible spectrophotometry[edit]. Main article: Ultraviolet-visible spectroscopy. Most spectrophotometers are used in the UV ...
E. I. Stearns, "Applications of Near Infra-Red Spectrophotometry," J. Opt. Soc. Am. 33, 27-30 (1943) ... Survey of Near Infra-Red Communication Systems W. S. Huxford and John R. Platt. J. Opt. Soc. Am. 38(3) 253-268 (1948) ... An Infra-Red Spectrophotometer for Industrial Research E. J. Martin, A. W. Fischer, B. Mandel, and R. E. Nusbaum. J. Opt. Soc. ... The Sensitivity of the Human Eye to Infra-Red Radiation Donald R. Griffin, Ruth Hubbard, and George Wald. J. Opt. Soc. Am. 37(7 ...
Fourier transform infrared spectrophotometry (FTIS) facility. The Fourier transform infrared spectrophotometry (FTIS) facility ... Complete hemispherical infrared laser-based reflectometer (CHILR). A custom instrument, the Complete Hemispherical infrared ... Advanced infrared radiometry and imaging (AIRI). Radiation thermometers and blackbodies can be calibrated using a set of ... The continuous-wave terahertz spectrometer makes use of two near-infrared lasers. The first laser is a fixed-frequency cw ring ...
Fourier transform infrared spectrophotometry (FTIS) facility The Fourier transform infrared spectrophotometry (FTIS) facility ... The LBIR facility provides calibrations of blackbody and other sources and detectors that operate in a low-background infrared ... We have constructed, calibrated, and tested a cryogenic low-background infrared radiometer for both spectral radiance and ... The group also establishes and disseminates measurement scales for optical/infrared properties of materials and performs ...
Ultraviolet Visible Near Infrared Spectrophotometry. UV-Vis-NIR transmission spectrum collected on Sodalime glass with overlaid ... Ultraviolet-Visible-Near Infrared spectrophotometry (UV-Vis-NIR) is a non-destructive, non-contact optical characterization ...
This study investigated the effectiveness of near infrared (NIR) spectrophotometry for measuring abdominal saturation in a rat ... JOURNAL OF NEAR INFRARED SPECTROSCOPY, cilt.26, sa.4, ss.235-244, 2018 (SCI İndekslerine Giren Dergi) ... Initial and final NIR spectrophotometry measurements were compared. No statistically significant difference was found in the ... the use of NIR spectrophotometry can be considered a good non-invasive alternative method for early diagnosis of acute ...
title = "SOFIA INFRARED SPECTROPHOTOMETRY of COMET C/2012 K1 (PAN-STARRS)",. abstract = "We present pre-perihelion infrared 8- ... SOFIA INFRARED SPECTROPHOTOMETRY of COMET C/2012 K1 (PAN-STARRS). Charles E. Woodward, Michael S P Kelley, David E. Harker, ... SOFIA INFRARED SPECTROPHOTOMETRY of COMET C/2012 K1 (PAN-STARRS). / Woodward, Charles E.; Kelley, Michael S P; Harker, David E ... Fingerprint Dive into the research topics of SOFIA INFRARED SPECTROPHOTOMETRY of COMET C/2012 K1 (PAN-STARRS). Together they ...
Spectrophotometry, branch of spectroscopy that deals with measurement of the radiant energy transmitted or reflected by a body ... Infrared spectrophotometry is most commonly used in studying the molecular structures of complex organic compounds. ... Spectrophotometry, branch of spectroscopy that deals with measurement of the radiant energy transmitted or reflected by a body ... Spectrophotometry of protein solutions (the measurement of the degree of absorbance of light by a protein within a specified ...
IR spectrophotometryEdit. Main article: Infrared spectroscopy. Spectrophotometers designed for the infrared region are quite ... "Spectrophotometry". NIST. Retrieved Dec 23, 2018.. *^ a b c d e f g h i j Ninfa AJ, Ballou DP, Benore M (2010). Fundamental ... "Spectrophotometry Applications and Fundamentals". www.mt.com. Mettler-Toledo International Inc. Retrieved Jul 4, 2018.. ... UV-visible spectrophotometryEdit. Main article: Ultraviolet-visible spectroscopy. Most spectrophotometers are used in the UV ...
Chemical component of gallstone in Songklanagarind Hospital determined by infrared spectrophotometry. Authors: D Premprapha. P ... Objective: To identify the chemical composition of gallstones in Songklanagarind Hospital by infrared spectrophotometry and ... Gallstones were obtained from cholecystectomy patients in Songklanagarind Hospital and examined with spectrophotometry KBr disk ...
Spectrophotometry, infrared spectroscopy Absorption spectra Table 1. Supersaturation measurement methods (Profos, 1987).[11] ... This can be determined using satellite data from the Atmospheric Infrared Sounder.[23] Evidence of supersaturation in the ... "The Global Distribution of Supersaturation in the Upper Troposphere from the Atmospheric Infrared Sounder". Journal of Climate ...
... infrared spectrophotometry; raman spectroscopy; nuclear magnetic resonance spectroscopy; electron spin resonance spectroscopy; ... ultraviolet and visible spectrophotometry; fluorescence and phosphorescence spectrophotometry; flame emission and atomic ... A simple generalized instrument suitable for fluorescence and phosphorescence spectrophotometry usually comprises a source of ... and near infrared absorption photometry and with fluorescent and phosphorescent emission systems. All the presently known ...
Identifying Plastic Encapsulant Materials by Pyrolysis Infrared Spectrophotometry Robert K. Lowry ; Robert K. Lowry ... "Identifying Plastic Encapsulant Materials by Pyrolysis Infrared Spectrophotometry." Proceedings of the ISTFA 1998. ISTFA 1998: ... electronic molding compounds, Fourier transform infrared analysis, plastic encapsulated microcircuits, pyrolysis infrared ... Pyrolysis of the EMC, followed by Fourier Transform Infrared (FT-IR) chemical analysis of the condensates of organic substances ...
5.2.3 Infrared Spectrophotometry. 5.2.4 NMR Spectrometry. 5.2.5 Polarography. 5.2.6 Column Chromatography. 5.2.7 Thin-Layer ... 2.2.4 Infrared Spectrophotometry. 2.2.5 NMR Spectrometry. 2.2.6 Polarography. 2.2.7 Titrimetric Methods. 2.2.8 Gravimetric ... 8.2.2 Infrared Spectrophotometry. 8.2.3 Thin-Layer Chromatography. 8.2.4 Column and High-Performance Column Chromatography. 8.2 ... 7.2.1 Ultraviolet Spectrophotometry. 7.2.2 Colorimetric Methods. 7.2.3 Fluorimetry. 7.2.4 Column Chromatography. 7.2.5 Thin- ...
Infrared spectrophotometry. *Near infrared spectrophotometry. *Raman spectrophotometry. *Nuclear magnetic resonance ...
Infrared absorption spectrophotometry.. Comparison: Cholecalciferol CRS.. Corresponding. Pre-cholecalciferol. 0.05% max. ...
Chromatography; Criminalistics; Evidence identification; Hair and fiber analysis; Infrared techniques; Scientific techniques; ... Spectrophotometry; Spectroscopy; Trace evidence. To cite this abstract, use the following link:. http://www.ncjrs.gov/App/ ... thin layer chromatography and infrared spectroscopy. Application of these techniques is dependent on the nature of the sample, ...
It uses either visible or infrared light to determine the light transmission, absorption, or reflectance properties of a ... Source for information on Micro-spectrophotometry: World of Forensic Science dictionary. ... Micro-spectrophotometry Micro-spectrophotometry (MSP) is an essential tool in the forensic analysis of many kinds of trace ... Micro-spectrophotometry. Micro-spectrophotometry (MSP) is an essential tool in the forensic analysis of many kinds of trace ... Infrared Absorption Spectrophotometry 344. Ultraviolet and Visible Absorption Spectrophotometry 347 ...
Static and Dynamic Spectrophotometry. Near Infrared Spectroscopy. Pulse oximetry. Chemo-metrics. Physiological Measurement. ... Qassem, M. and Kyriacou, P. (2014). Use of reflectance near-infrared spectroscopy to investigate the effects of daily ... Abay, T.Y. and Kyriacou, P.A. (2014). Investigation of photoplethysmography and near infrared spectroscopy for the assessment ... Qassem, M. and Kyriacou, P.A. (2012). In vitro spectrophotometric near infrared measurements of skin absorption and dehydration ...
Near‐infrared spectrophotometry Authors: Salganicoff, Leon Article Type: Research Article Citation: Biofactors, vol. 7, no. 3, ... Near‐infrared spectroscopy in the diagnosis of mitochondrial disorders Authors: Bank, William , Park, Jane , Lech, Gwen , ... Correlative magnetic resonance and near‐infrared technologies for the evaluation of mitochondrial disease ...
  • Nosrati R, Lin S, Mohindra R, Ramadeen A, Toronov V, Dorian P. Study of the Effects of Epinephrine on Cerebral Oxygenation and Metabolism During Cardiac Arrest and Resuscitation by Hyperspectral Near-Infrared Spectroscopy. (harvard.edu)
  • Nosrati R, Lin S, Ramadeen A, Monjazebi D, Dorian P, Toronov V. Cerebral Hemodynamics and Metabolism During Cardiac Arrest and Cardiopulmonary Resuscitation Using Hyperspectral Near Infrared Spectroscopy. (harvard.edu)
  • Hocke LM, Tong Y, Lindsey KP, de B Frederick B. Comparison of peripheral near-infrared spectroscopy low-frequency oscillations to other denoising methods in resting state functional MRI with ultrahigh temporal resolution. (harvard.edu)
  • Kim YJ, Lee HJ, Shin HS, Shin Y. Near-infrared reflectance spectroscopy as a rapid and non-destructive analysis tool for curcuminoids in turmeric. (harvard.edu)
  • Recent works in developing multispectral image analysis (Pirard, 2004) have demonstrated its superior potential with respect to conventional colour imaging, but at the same time reconciliation with spectroscopic databases such as the Quantitative Data File III (Criddle and Stanley, 1993) still needs a more in-depth investigation as well as the possibility to extend both imaging and spectroscopy into the near infrared domain. (upm.es)
  • Spectrophotometry is a branch of electromagnetic spectroscopy concerned with the quantitative measurement of the reflection or transmission properties of a material as a function of wavelength. (wikipedia.org)
  • Spectrophotometry , branch of spectroscopy that deals with measurement of the radiant energy transmitted or reflected by a body as a function of the wavelength. (britannica.com)
  • [2] It is more specific than the general term electromagnetic spectroscopy in that spectrophotometry deals with visible light, near- ultraviolet , and near- infrared , but does not cover time-resolved spectroscopic techniques. (wikipedia.org)
  • Techniques used to examine and compare these fibers include microscopy, microspectrophotometry, thin layer chromatography and infrared spectroscopy. (ncjrs.gov)
  • Breast-milk intake (g/d) was measured from saliva samples by using infrared spectroscopy. (nih.gov)
  • L. Wang, J. Chapman, O. von Ramm, R.A. Palmer and Boris Mizaikoff, "Classification of Atherosclerotic Rabbit Aorta Samples by Mid-Infrared Spectroscopy and Multivariate Data Analysis" , J. Biomed. (duke.edu)
  • We previously validated the near-infrared spectroscopy-derived hemoglobin difference (HbD) signal (cerebral oxyhemoglobin - deoxyhemoglobin) as a reliable measure of changes in CBF in animal models. (biomedsearch.com)
  • Bates , A. N.: Analysis of endrin residues in flour by infrared spectroscopy. (springer.com)
  • Principles of infrared (IR) spectroscopy. (unige.it)
  • Functional Near-Infrared Spectroscopy (fNIRS) is an increasingly established technology with a potential to satisfy these conditions. (frontiersin.org)
  • Functional Near-Infrared Spectroscopy (fNIRS) is an increasingly established technology pioneered by Jöbsis (1977) that allows non-invasive, comparatively low-cost, compact and hazard-free continuous measurement of cerebral oxygenation levels using near-infrared light. (frontiersin.org)
  • The roots can be reliably differentiated via Fourier transform infrared spectroscopy with attenuated total reflection (FTIR-ATR). (frontiersin.org)
  • After remarkable adjustments and improvements of the IR spectroscopy, the Fourier transform infrared (FTIR) spectroscopy became a powerful tool for the differentiation and identification of different samples. (frontiersin.org)
  • The present invention is related to near-infrared (NIR) microscopes for spectroscopic and image analysis, and, in particular, to microscopes useful for both NIR spectroscopy, NIR chemical imaging and NIR volumetric chemical imaging. (google.com)
  • X-ray diffraction (XRD), infrared spectroscopy (IR), and colorimetry (VIS). (cdc.gov)
  • The purpose of this study was to determine if photoacoustic Fourier transform infrared (PA-FTIR) spectroscopy could be a viable alternative for laboratory analysis of crystalline silica samples. (cdc.gov)
  • the composition of the chemical groups was determined by infrared spectroscopy. (bireme.br)
  • To monitor the cerebral circulation continuously and noninvasively, we used near-infrared spectroscopy (NIRS) to determine quantitative changes in cerebral concentrations of oxygenated hemoglobin (HbO 2 ) and deoxygenated hemoglobin (Hb) from the first hours of life. (aappublications.org)
  • Near-infrared spectroscopy (NIRS) is a relatively recently developed technique that can provide continuous bedside quantitation of changes in cerebral concentration of oxygenated hemoglobin (HBO 2 ) and deoxygenated hemoglobin (Hb). (aappublications.org)
  • The resulting polyesters were complexed with copper (II) or silver (I). The new polymers were characterized by proton and carbon nuclear magnetic resonance spectroscopy, inherent viscosity, infrared spectroscopy, differential scanning calorimetry and thermogravimetric analysis. (mdpi.com)
  • The corresponding metal complexes were characterized by differential scanning calorimery and infrared spectroscopy. (mdpi.com)
  • The goal of this study was to investigate and to characterize the differences in the color of the scales among preserved specimens and to analyze the differences in the microstructures of the scales that cover their bodies using near-infrared spectroscopy, and to evaluate whether the latter is efficient in distinguishing the populations. (scielo.br)
  • Near-infrared spectroscopy (NIRS) has the potential to detect differences in the chemical composition of the exoskeleton through the stretching and bending of functional groups CH, NH and OH of organic molecules ( Pasquini, 2003 ). (scielo.br)
  • 1.1 Infrared (IR) spectroscopy is a valuable method of fiber polymer identification and comparison in forensic examinations. (bsigroup.com)
  • Surface and microanalysis: infrared spectroscopy, scanning and transmission electron microscopy, Auger electron and x-ray photoelectron spectroscopy. (mcgill.ca)
  • Infrared Spectrometry. (booktopia.com.au)
  • The intIRpret computer program for the identification of the principal components of chemical mixtures of hazardous wastes based on analysis by infrared spectrometry was described. (cdc.gov)
  • Following on from our previous foray into the UV-visible area of the spectrum, in this article we discuss its nearest neighbour in the spectral scale, namely near infrared (NIR) spectrometry. (spectroscopyeurope.com)
  • P&CAM 159 [4] and S272 [5] use similar samplers with measurement by fluorescence spectrophotometry. (cdc.gov)
  • Bulk analysis: spectrophotometry using UV, visible, flame and atomic absorption, x-ray diffraction and x-ray fluorescence. (mcgill.ca)
  • Ultraviolet-Visible-Near Infrared spectrophotometry (UV-Vis-NIR) is a non-destructive, non-contact optical characterization technique used to measure reflectance, absorbance, and transmittance of liquids and solids. (covalentmetrology.com)
  • Hanssen is responsible for the realizing and maintaining NIST's scales for spectral reflectance, transmittance, and emittance of materials at infrared wavelengths. (wikipedia.org)
  • FTIS employs a Fourier-transform infrared spectrophotometer and custom integrating sphere to measure absolute infrared reflectance, transmittance, and absorbance. (wikipedia.org)
  • It uses either visible or infrared light to determine the light transmission, absorption, or reflectance properties of a material. (encyclopedia.com)
  • THE INVENTION UW-Madison researchers have developed prediction equations that can estimate corn silage nutrition based on the unique light patterns of different chemical components using near-infrared reflectance spectrophotometry (NIRS). (warf.org)
  • Characterization and Identification of Spilled Residual Fuel Oils by Gas Chromatography and Infrared Spectrophotometry. (epa.gov)
  • The trans fat content of foods can be measured by gas chromatography or infrared spectrophotometry. (madsci.org)
  • Infrared absorption spectrophotometry. (alibaba.com)
  • Crystalline silica can also be determined by visible absorption spectrophotometry (e.g., method 7601), but polymorphs cannot be distinguished. (cdc.gov)
  • The amounts of complexed copper and silver were determined by atomic absorption spectrophotometry. (mdpi.com)
  • He manages the Fourier Transform Infrared Spectrophotometry (FTIS) Facility, which was developed to take low uncertainty measurements. (wikipedia.org)
  • 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. (harvard.edu)
  • In this work, a study of the molecular structure and the infrared and Raman spectra of this chemical is presented. (isharonline.org)
  • Pyrolysis of the EMC, followed by Fourier Transform Infrared (FT-IR) chemical analysis of the condensates of organic substances evolved by the pyrolysis, and comparison of the spectra with a reference library of known EMCs, provides a rapid means of specific EMC identification. (asminternational.org)
  • 1.3 This test method assumes that specimens and infrared spectra are prepared and analyzed by experienced personnel and that the equipment is operated according to the manufacturer's direction for optimum performance. (astm.org)
  • Infrared spectra show that it has carbon-rich material found in carbonaceous chondrites. (wikipedia.org)
  • Bellamy , L. J.: The infrared spectra of complex molecules. (springer.com)
  • Self-training, self-optimizing expert system for interpretation of the infrared spectra of environmental mixtures. (cdc.gov)
  • A multitude of spatially resolved spectra of transmitted, reflected, emitted or scattered near infrared wavelength radiation light from the illuminated area of the sample is collected and a collimated beam is produced therefrom. (google.com)
  • Comparison of far-infrared intensity spectra for (a) Zn-,(b) Fe-,and (c) Mn-coordinated complexes in aqueous and gas phases in the500-0 cm-1 region. (nih.gov)
  • Although spectrophotometry is most commonly applied to ultraviolet, visible , and infrared radiation, modern spectrophotometers can interrogate wide swaths of the electromagnetic spectrum , including x-ray , ultraviolet , visible , infrared , and/or microwave wavelengths. (wikipedia.org)
  • Ultraviolet spectrophotometry is particularly useful in detecting colourless substances in solution and measuring their concentration. (britannica.com)
  • Blinn , R. C: The utility of ultraviolet spectrophotometry in determining pesticide residues in foodstuiffs. (springer.com)
  • In astronomy , the term spectrophotometry refers to the measurement of the spectrum of a celestial object in which the flux scale of the spectrum is calibrated as a function of wavelength , usually by comparison with an observation of a spectrophotometric standard star, and corrected for the absorption of light by the Earth's atmosphere. (wikipedia.org)
  • In chemistry , spectrophotometry is the quantitative measurement of the reflection or transmission properties of a material as a function of wavelength. (wikipedia.org)
  • Spectrophotometry uses photometers , known as spectrophotometers, that can measure a light beam's intensity as a function of its color (wavelength). (wikipedia.org)
  • Infrared images of Jupiter at 5-micrometer wavelength during the Voyager 1 encounter. (arizona.edu)
  • The system includes an illumination source which illuminates an area of a sample using light in the near infrared radiation wavelength and light in the visible wavelength. (google.com)
  • The visible wavelength light from the illuminated area of the sample is simultaneously detected providing for the simultaneous visible and near infrared chemical imaging analysis of the sample. (google.com)
  • Photoelectric cells in a spectrophotometer device worn on the forehead measure the amount of each wavelength of light reflected by cerebral blood flow in the activated cortical tissue and send the data to a computer, which then calculates the ratio of red to infrared light and translates it into a visual signal of corresponding to oxygenation level on a graphical interface the patient can see. (wikipedia.org)
  • The use of IR microscopes, coupled with Fourier transform infrared (FTIR) spectrometers, has greatly simplified the IR analysis of single fibers, thus making the technique feasible for routine use in the forensic laboratory. (bsigroup.com)
  • Two efficient means for performing three dimensional near infrared chemical imaging microscopy are provided. (google.com)
  • In parallel, a conformational analysis on the CHO-blocked peptide and their tertbutyloxycarbonylated synthetic precursors was performed in the crystal state and in solution using X-ray diffraction, infrared absorption, and 1H nuclear magnetic resonance. (biomedsearch.com)
  • Crystals were analysed by infrared spectrophotometry, thermogravimetry and X-ray diffraction. (ias.ac.in)
  • Any aerosol (e.g., tobacco smoke) which absorbs infrared radiation near 2950 cm-1 interferes. (cdc.gov)
  • A chemical imaging system is provided which uses a near infrared radiation microscope. (google.com)
  • A near infrared imaging spectrometer is provided for selecting a near infrared radiation image of the collimated beam. (google.com)
  • A custom instrument, the Complete Hemispherical infrared Laser-based Reflectometer (CHILR), employs a gold integrating sphere and is used for the measurement. (nist.gov)
  • The group also establishes and disseminates measurement scales for optical/infrared properties of materials and performs supporting theoretical analysis. (nist.gov)
  • He is the project leader for infrared spectrophotometry in the Sensor Science Division of the Physical Measurement Laboratory. (wikipedia.org)
  • [2] Spectrophotometry uses photometers , known as spectrophotometers, that can measure the intensity of a light beam at different wavelengths. (wikipedia.org)
  • The spectrophotometry was taken with the Keck I/Low Resolution Imaging Spectrometer between wavelengths 434 and 912 nm in the B, g, V, R, I, and RG850 filters as it was leaving the Earth-Moon system on 2020 March 23 UTC. (caltech.edu)
  • Objective: To identify the chemical composition of gallstones in Songklanagarind Hospital by infrared spectrophotometry and determine the relation of body mass index with composition of gallstones.Materials and Methods: Gallstones were obtained from cholecystectomy patients in Songklanagarind Hospital and examined with spectrophotometry KBr disk method. (who.int)
  • Spectrophotometry is a tool that hinges on the quantitative analysis of molecules depending on how much light is absorbed by colored compounds. (wikipedia.org)
  • Quantitative analysis of petroleum oil pollutants by infrared spectrophotometry / Michael Gurenfeld. (epa.gov)
  • The continuous-wave terahertz spectrometer makes use of two near-infrared lasers. (nist.gov)
  • Two independent analytical instruments were used to measure the resulting SF6 concentrations in the LEV exhaust duct, a Bruel & Kjaer (B&K) photoacoustic analyzer and a Miran SapphIRe infrared spectrometer. (cdc.gov)
  • A Miran SapphIRe infrared spectrometer was used to measure the resulting SF6 concentrations in the LEV exhaust duct. (cdc.gov)
  • We present pre-perihelion infrared 8-31 μm spectrophotometric and imaging observations of comet C/2012 K1 (Pan-STARRS), a dynamically new Oort Cloud comet, conducted with NASA's Stratospheric Observatory for Infrared Astronomy facility (+FORCAST) in 2014 June. (elsevier.com)
  • A Fourier transform infrared spectrophotometric method was described for the determination of quartz , mica (sericite) and feldspar( potassium feldspar) in respirable dust in Taebaek area. (bvsalud.org)
  • Determination of Nitrite and Nitrogen Dioxide by Spectrophotometry After Solid Phase Extraction. (ebscohost.com)
  • An example of an experiment in which spectrophotometry is used is the determination of the equilibrium constant of a solution. (wikipedia.org)
  • Infrared determination of aldrin and dieldrin in aldrin-treated soil. (springer.com)
  • Ansary A, Abdel-Moety MM, Abdel-Gawad FM, Mohamed EA, Khater MM (2012) Simultaneous Determination of Carvedilol and Hydrochlorothiazide in Tablets and Spiked Human Plasma using Derivative Spectrophotometry. (omicsonline.org)
  • This study investigated the effectiveness of near infrared (NIR) spectrophotometry for measuring abdominal saturation in a rat model of induced mesenteric ischemia. (erdogan.edu.tr)
  • The IR technology constitutes a rapid and effective tool to predict several properties of naphtha from the correlation of the spectrum in the infrared area and the properties. (scribd.com)
  • PIR uses a sensor similar to the NIR sensor to detect light from a narrow band of the infrared spectrum that corresponds to the amount of heat being generated by an active brain region, as well as the local blood oxygenation level. (wikipedia.org)
  • Identity with gas chromatographic and infrared data is given in an elaborate fashion and comparisons are made in the absence of extremely expensive analytical equipment. (epa.gov)
  • 4.3 This test method provides an infrared technique to determine the unsaturation level of hydrogenated nitrile rubbers in the raw state. (astm.org)
  • Developed by Dr. Jeffrey Carmen, a privately practicing psychologist in New York, passive infrared HEG is a marriage of the classic hemoencephalography principles employed by Toomim and a technique known as thermoscopy. (wikipedia.org)
  • NOTE: Sta nd ard glas s c ells m ayb e use d if infrared quartz cells are not available. (cdc.gov)
  • No details for operation of infrared spectrophotometers are included in this test method. (astm.org)
  • A calibration curve for infrared absorptiometry of nitrogen in silicon at 963 cm-1 was obtained by the use of charged particle activation analysis with the 14N(p, α) 11C reaction. (ebscohost.com)
  • Infrared analysis overcomes both of these limitations. (cdc.gov)
  • Spectrophotometry is often used in measurements of enzyme activities, determinations of protein concentrations, determinations of enzymatic kinetic constants, and measurements of ligand binding reactions. (wikipedia.org)
  • Measurements were repeated using NIR spectrophotometry probes after the abdomen was surgically closed. (erdogan.edu.tr)
  • Initial and final NIR spectrophotometry measurements were compared. (erdogan.edu.tr)
  • Infrared spectrophotometry is most commonly used in studying the molecular structures of complex organic compounds . (britannica.com)
  • The emission in the Unidentified Infrared Bands (UIBs) comes from the molecular cloud and the interface and extends into the HII region. (u-strasbg.fr)
  • In order to determine the respective concentrations of reactants and products at this point, the light transmittance of the solution can be tested using spectrophotometry. (wikipedia.org)
  • The LBIR facility provides calibrations of blackbody and other sources and detectors that operate in a low-background infrared environment, typically in space-simulating vacuum chambers in which cryogenically-cooled interior shrouds surround the instruments. (nist.gov)
  • For heat-treated FZ silicon and Czochralski (CZ) silicon, this relation was found to give underestimated nitrogen concentration suggesting the existence of infrared insensitive nitrogen. (ebscohost.com)