Spectrophotometry, Atomic
Spectrophotometry
Spectrophotometry, Ultraviolet
Spectrophotometry, Infrared
Tablets
Zinc
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.
Graphite
Microchemistry
Oxyhemoglobins
Calibration
Chromatography, High Pressure Liquid
Oxidation-Reduction
A chemical reaction in which an electron is transferred from one molecule to another. The electron-donating molecule is the reducing agent or reductant; the electron-accepting molecule is the oxidizing agent or oxidant. Reducing and oxidizing agents function as conjugate reductant-oxidant pairs or redox pairs (Lehninger, Principles of Biochemistry, 1982, p471).
Copper
Aluminum
Indocyanine Green
Color
Coloring Agents
Lead
Indicators and Reagents
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)
Trace Elements
Spectrum Analysis
Colorimetry
Blood Volume Determination
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.
Hydrogen-Ion Concentration
Chromatography, Thin Layer
Flow Injection Analysis
Chromium
Densitometry
Potassium Iodide
Metals, Heavy
Hydrochloric Acid
Mercury
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.
Magnesium
Spinal Puncture
Baccharis
Iron
Cerebrospinal Fluid Proteins
Reproducibility of Results
The statistical reproducibility of measurements (often in a clinical context), including the testing of instrumentation or techniques to obtain reproducible results. The concept includes reproducibility of physiological measurements, which may be used to develop rules to assess probability or prognosis, or response to a stimulus; reproducibility of occurrence of a condition; and reproducibility of experimental results.
Tantalum
Temperature
Hemoglobins
Chemistry
Cadmium
Chemical Phenomena
Oxygen
Solutions
Hair
Manganese
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)
Water
Erythrocytes
Water Pollutants, Chemical
Flavins
Nephelometry and Turbidimetry
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.
Chromatography, Gas
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.
Platinum
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".
Electron Transport Complex IV
A multisubunit enzyme complex containing CYTOCHROME A GROUP; CYTOCHROME A3; two copper atoms; and 13 different protein subunits. It is the terminal oxidase complex of the RESPIRATORY CHAIN and collects electrons that are transferred from the reduced CYTOCHROME C GROUP and donates them to molecular OXYGEN, which is then reduced to water. The redox reaction is simultaneously coupled to the transport of PROTONS across the inner mitochondrial membrane.
Palladium
Limit of Detection
Nickel
Methylene Blue
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.
Subarachnoid Hemorrhage
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.
Selenium
Cobalt
Cytochromes
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.
Calcium
A basic element found in nearly all organized tissues. It is a member of the alkaline earth family of metals with the atomic symbol Ca, atomic number 20, and atomic weight 40. Calcium is the most abundant mineral in the body and combines with phosphorus to form calcium phosphate in the bones and teeth. It is essential for the normal functioning of nerves and muscles and plays a role in blood coagulation (as factor IV) and in many enzymatic processes.
Ultrafiltration
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).
Carbon Monoxide
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)
Electron Spin Resonance Spectroscopy
A technique applicable to the wide variety of substances which exhibit paramagnetism because of the magnetic moments of unpaired electrons. The spectra are useful for detection and identification, for determination of electron structure, for study of interactions between molecules, and for measurement of nuclear spins and moments. (From McGraw-Hill Encyclopedia of Science and Technology, 7th edition) Electron nuclear double resonance (ENDOR) spectroscopy is a variant of the technique which can give enhanced resolution. Electron spin resonance analysis can now be used in vivo, including imaging applications such as MAGNETIC RESONANCE IMAGING.
Pharmaceutical Preparations
Hydrochlorothiazide
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.
Environmental Monitoring
Molybdenum
Myoglobin
Models, Chemical
Reference Values
Technology, Pharmaceutical
The application of scientific knowledge or technology to pharmacy and the pharmaceutical industry. It includes methods, techniques, and instrumentation in the manufacture, preparation, compounding, dispensing, packaging, and storing of drugs and other preparations used in diagnostic and determinative procedures, and in the treatment of patients.
Quality Control
Melanins
Cyanides
Spectroscopy, Fourier Transform Infrared
Spectroscopy, Near-Infrared
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.
Solvents
Electron Transport
Evaluation Studies as Topic
Molecular Structure
Mass Spectrometry
Cattle
Absorption
Silicon Dioxide
Plant Extracts
Oxygen Consumption
Electrons
Stable elementary particles having the smallest known negative charge, present in all elements; also called negatrons. Positively charged electrons are called positrons. The numbers, energies and arrangement of electrons around atomic nuclei determine the chemical identities of elements. Beams of electrons are called CATHODE RAYS.
Micelles
Particles consisting of aggregates of molecules held loosely together by secondary bonds. The surface of micelles are usually comprised of amphiphatic compounds that are oriented in a way that minimizes the energy of interaction between the micelle and its environment. Liquids that contain large numbers of suspended micelles are referred to as EMULSIONS.
Reference Standards
Catalysis
Buffers
Antioxidants
Methanol
Solubility
Electrochemistry
Magnetic Resonance Spectroscopy
NADP
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)
Drugs, Chinese Herbal
Heme
Arsenic
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)
Rats, Inbred Strains
Carotenoids
Thermodynamics
A rigorously mathematical analysis of energy relationships (heat, work, temperature, and equilibrium). It describes systems whose states are determined by thermal parameters, such as temperature, in addition to mechanical and electromagnetic parameters. (From Hawley's Condensed Chemical Dictionary, 12th ed)
Liver
DNA Adducts
Drug Carriers
Forms to which substances are incorporated to improve the delivery and the effectiveness of drugs. Drug carriers are used in drug-delivery systems such as the controlled-release technology to prolong in vivo drug actions, decrease drug metabolism, and reduce drug toxicity. Carriers are also used in designs to increase the effectiveness of drug delivery to the target sites of pharmacological actions. Liposomes, albumin microspheres, soluble synthetic polymers, DNA complexes, protein-drug conjugates, and carrier erythrocytes among others have been employed as biodegradable drug carriers.
Metals
Cytochrome c Group
Protein Binding
Superoxide Dismutase
Catalase
Oxidoreductases
The class of all enzymes catalyzing oxidoreduction reactions. The substrate that is oxidized is regarded as a hydrogen donor. The systematic name is based on donor:acceptor oxidoreductase. The recommended name will be dehydrogenase, wherever this is possible; as an alternative, reductase can be used. Oxidase is only used in cases where O2 is the acceptor. (Enzyme Nomenclature, 1992, p9)
Calorimetry, Differential Scanning
Materials Testing
Mathematics
Chelating Agents
Carbonic Anhydrases
Flavin-Adenine Dinucleotide
Rabbits
Nitrogenase
Phenobarbital
Sensitivity and Specificity
Polyethylene Glycols
Polymers of ETHYLENE OXIDE and water, and their ethers. They vary in consistency from liquid to solid depending on the molecular weight indicated by a number following the name. They are used as SURFACTANTS, dispersing agents, solvents, ointment and suppository bases, vehicles, and tablet excipients. Some specific groups are NONOXYNOLS, OCTOXYNOLS, and POLOXAMERS.
Chemistry, Pharmaceutical
Circular Dichroism
Food Contamination
Oxidative Stress
Ascorbic Acid
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.
Horses
Drug Delivery Systems
Fluorescence
Rats, Sprague-Dawley
Nitrites
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)
Gas Chromatography-Mass Spectrometry
Drug Combinations
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).
Hydrogen Peroxide
Cations
Edetic Acid
Scattering, Radiation
Oxidants
Rats, Wistar
Lipid Peroxidation
Peroxidase
NAD
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)
Binding Sites
Escherichia coli
A species of gram-negative, facultatively anaerobic, rod-shaped bacteria (GRAM-NEGATIVE FACULTATIVELY ANAEROBIC RODS) commonly found in the lower part of the intestine of warm-blooded animals. It is usually nonpathogenic, but some strains are known to produce DIARRHEA and pyogenic infections. Pathogenic strains (virotypes) are classified by their specific pathogenic mechanisms such as toxins (ENTEROTOXIGENIC ESCHERICHIA COLI), etc.
Anaerobiosis
Microscopy, Electron, Transmission
Environmental Exposure
Glutathione Peroxidase
Serum Albumin
Cytochrome P-450 Enzyme System
A superfamily of hundreds of closely related HEMEPROTEINS found throughout the phylogenetic spectrum, from animals, plants, fungi, to bacteria. They include numerous complex monooxygenases (MIXED FUNCTION OXYGENASES). In animals, these P-450 enzymes serve two major functions: (1) biosynthesis of steroids, fatty acids, and bile acids; (2) metabolism of endogenous and a wide variety of exogenous substrates, such as toxins and drugs (BIOTRANSFORMATION). They are classified, according to their sequence similarities rather than functions, into CYP gene families (>40% homology) and subfamilies (>59% homology). For example, enzymes from the CYP1, CYP2, and CYP3 gene families are responsible for most drug metabolism.
Permeability
Plant Leaves
Microscopy, Electron, Scanning
Microscopy in which the object is examined directly by an electron beam scanning the specimen point-by-point. The image is constructed by detecting the products of specimen interactions that are projected above the plane of the sample, such as backscattered electrons. Although SCANNING TRANSMISSION ELECTRON MICROSCOPY also scans the specimen point by point with the electron beam, the image is constructed by detecting the electrons, or their interaction products that are transmitted through the sample plane, so that is a form of TRANSMISSION ELECTRON MICROSCOPY.
Dose-Response Relationship, Drug
Swine
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).
Structure-Activity Relationship
Nanoparticles
Substrate Specificity
Analysis of Variance
Biological Markers
Measurable and quantifiable biological parameters (e.g., specific enzyme concentration, specific hormone concentration, specific gene phenotype distribution in a population, presence of biological substances) which serve as indices for health- and physiology-related assessments, such as disease risk, psychiatric disorders, environmental exposure and its effects, disease diagnosis, metabolic processes, substance abuse, pregnancy, cell line development, epidemiologic studies, etc.
Fluorescent Dyes
Osmolar Concentration
Occupational Exposure
Molecular Sequence Data
Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.
Protons
Protein Conformation
The characteristic 3-dimensional shape of a protein, including the secondary, supersecondary (motifs), tertiary (domains) and quaternary structure of the peptide chain. PROTEIN STRUCTURE, QUATERNARY describes the conformation assumed by multimeric proteins (aggregates of more than one polypeptide chain).
A comparison of techniques for the quantitative analysis of hyaluronic acid in equine synovial fluid. (1/8806)
A comparison of methods of preparing the hyaluronic acid of equine synovial fluid for quantitative spectrophotographic analysis is presented. A new method is proposed which appears superior to the previous methods. (+info)The direct spectrophotometric observation of benzo(a)pyrene phenol formation by liver microsomes. (2/8806)
Optical spectral repetitive scan analysis during the oxidative metabolism of benzo(a)pyrene by liver microsomal suspensions reveals the time-dependent formation of an intermediate(s) of which the visible spectra resemble those of several benzo(a)pyrene phenols. Liver microsomes from 3-methylcholanthrene-treated rats showed a greater rate of formation of the phenols than did microsomes from control animals; the rate of formation catalyzed by liver microsomes from phenobarbital-pretreated rats was intermediate. When 3-hydroxybenzo(a)pyrene was used as a standard for comparison of activity, the rates of formation of phenols were compared when measured by fluorometric, spectrophotometric, or high-pressure liquid chromatographic analytical techniques. An epoxide hydrase inhibitor, 1,1,1-trichloropropene-2,3-oxide, enhanced phenol formation regardless of the source of liver microsomes, and 7,8-benzoflavone inhibited control and 3-methylcholanthrene-induced microsomal metabolism of benzo(a)pyrene, 7,8-Benzoflavone did not effect benzo(a)pyrene metabolism by liver microsomes from phenobarbital-pretreated rats. The effect of inhibitors on the spectrophotometric assay correlates well with the results obtained from benzo(a)pyrene metabolite analysis using high-pressure liquid chromatography. (+info)Accumulation of astaxanthin all-E, 9Z and 13Z geometrical isomers and 3 and 3' RS optical isomers in rainbow trout (Oncorhynchus mykiss) is selective. (3/8806)
Concentrations of all-E-, 9Z- and 13Z- geometrical and (3R,3'R), (3R, 3'S) and (3S,3'S) optical isomers of astaxanthin were determined in rainbow trout liver, gut tissues, kidney, skin and blood plasma to evaluate their body distribution. Two cold-pelleted diets containing predominantly all-E-astaxanthin (36.9 mg/kg astaxanthin, 97% all-E-, 0.4% 9Z-, 1.5% 13Z-astaxanthin, and 1.1% other isomers, respectively) or a mixture of all-E- and Z-astaxanthins (35.4 mg/kg astaxanthin, 64% all-E-, 18.7% 9Z-, 12.3% 13Z-astaxanthin, and 2.0% other isomers, respectively), were fed to duplicate groups of trout for 69 d. Individual E/Z isomers were identified by VIS- and 1H-NMR-spectrometry, and quantified by high-performance liquid chromatography. Significantly higher total carotenoid concentration was observed in plasma of trout fed diets with all-E-astaxanthin (P < 0.05). The relative E/Z-isomer concentrations of plasma, skin and kidney were not significantly different among groups, whereas all-E-astaxanthin was higher in intestinal tissues and 13Z-astaxanthin was lower in liver of trout fed all-E-astaxanthin (P < 0.05). The relative amount of hepatic 13Z-astaxanthin (39-49% of total astaxanthin) was higher than in all other samples (P < 0.05). Synthetic, optically inactive astaxanthin was used in all experiments, and the determined dietary ratio between the 3R,3'R:3R, 3'S (meso):3S,3'S optical isomers was 25.3:49.6:25.1. The distribution of R/S-astaxanthin isomers in feces, blood, liver and fillet was similar to that in the diets. The ratio between (3S,3'S)- and (3R,3'R)-astaxanthin in the skin and posterior kidney was ca. 2:1 and 3:1, respectively, regardless of dietary E/Z-astaxanthin composition. The results show that geometrical and optical isomers of astaxanthin are distributed selectively in different tissues of rainbow trout. (+info)Reactivity of cyanate with valine-1 (alpha) of hemoglobin. A probe of conformational change and anion binding. (4/8806)
The 3-fold increase in the carbamylation rate of Val-1 (alpha) of hemoglobin upon deoxygenation described earlier is now shown to be a sensitive probe of conformational change. Thus, whereas this residue in methemoglobin A is carbamylated at the same rate as in liganded hemoglobin, upon addition of inositol hexaphosphate its carbamylation rate is enhanced 30% as much as the total change in the rate between the CO and deoxy states. For CO-hemoglobin Kansas in the presence of the organic phosphate, the relative increase in the carbamylation rate of this residue is about 50%. These results indicate that methemoglobin A and hemoglobin Kansas in the presence of inositol hexaphosphate do not assume a conformation identical with deoxyhemoglobin but rather form either a mixture of R and T states or an intermediate conformation in the region around Val-1 (alpha). Studies on the mechanism for the rate enhancement in deoxyhemoglobin suggest that the cyanate anion binds to groups in the vicinity of Val-1 (alpha) prior to proton transfer and carbamylation of this NH2-terminal residue. Thus, specific removal with carboxypeptidase B of Arg-141 (alpha), which is close to Val-1 (alpha) in deoxyhemoglobin, abolishes the enhancement in carbamylation. Chloride, which has the same valency as cyanate, is a better competitive inhibitor of the carbamylation of deoxyhemoglobin (Ki = 50 mM) compared with liganded hemoglobin. Nitrate and iodide are also effective inhibitors of the carbamylation of Val-1 (alpha) of deoxyhemoglobin (Ki = 35 mM); inorganic phosphate, sulfate, and fluoride are poor competitive inhibitors. The change in pKa of Val-1 (alpha) upon deoxygenation may be due to its differential interaction with chloride. (+info)Negligible amount of copper in hepatic L-tryptophan 2,3-dioxygenase. (5/8806)
During the purification of L-tryptophan 2,3-dioxygenase, a protohemoprotein from rat liver, both copper and heme contents of the preparations were found to be progressively increased as purification proceeded. However, the greater part of copper was removed in the late stages of the purification giving a copper to heme ratio less than 0.4. The small amounts of copper could further be reduced by one-half, by a mild treatment of enzyme with chelators such as ethylenedi aminetetraacetate, without any accompanying decrease in enzymatic activity. Since the turnover number of these enzyme preparations expressed per mol of enzyme-bound heme, 200 to 277 min-1 at 25 degrees, were either comparable to or slightly higher than those reported with homogeneous enzyme preparations, the heme in the preparation was considered to be of fully active L-tryptophan 2,3-dioxygenase and, therefore, such a small ratio of copper to heme, 0.1 to 0.3, indicated that copper is not a constituent of L-tryptophan 2,3-dioxygenase of rat liver. The findings were thus inconsistent with the results of Brady et al. (Brady, F. O., Monaco, M. E. Forman, H. J. Schutz, G., and Feigelson, P. (1972) J. Biol. Chem. 247, 7915-7922), who found that L-tryptophan 2,3-dioxygenase contained 2 g atoms of copper and 2 mol of heme/mol of enzyme. Possible reasons for this discrepancy have been discussed. (+info)Selenium redox biochemistry of zinc-sulfur coordination sites in proteins and enzymes. (6/8806)
Selenium has been increasingly recognized as an essential element in biology and medicine. Its biochemistry resembles that of sulfur, yet differs from it by virtue of both redox potentials and stabilities of its oxidation states. Selenium can substitute for the more ubiquitous sulfur of cysteine and as such plays an important role in more than a dozen selenoproteins. We have chosen to examine zinc-sulfur centers as possible targets of selenium redox biochemistry. Selenium compounds release zinc from zinc/thiolate-coordination environments, thereby affecting the cellular thiol redox state and the distribution of zinc and likely of other metal ions. Aromatic selenium compounds are excellent spectroscopic probes of the otherwise relatively unstable functional selenium groups. Zinc-coordinated thiolates, e.g., metallothionein (MT), and uncoordinated thiolates, e.g., glutathione, react with benzeneseleninic acid (oxidation state +2), benzeneselenenyl chloride (oxidation state 0) and selenocystamine (oxidation state -1). Benzeneseleninic acid and benzeneselenenyl chloride react very rapidly with MT and titrate substoichiometrically and with a 1:1 stoichiometry, respectively. Selenium compounds also catalyze the release of zinc from MT in peroxidation and thiol/disulfide-interchange reactions. The selenoenzyme glutathione peroxidase catalytically oxidizes MT and releases zinc in the presence of t-butyl hydroperoxide, suggesting that this type of redox chemistry may be employed in biology for the control of metal metabolism. Moreover, selenium compounds are likely targets for zinc/thiolate coordination centers in vivo, because the reactions are only partially suppressed by excess glutathione. This specificity and the potential to undergo catalytic reactions at low concentrations suggests that zinc release is a significant aspect of the therapeutic antioxidant actions of selenium compounds in antiinflammatory and anticarcinogenic agents. (+info)Structure and function in rhodopsin: further elucidation of the role of the intradiscal cysteines, Cys-110, -185, and -187, in rhodopsin folding and function. (7/8806)
The disulfide bond between Cys-110 and Cys-187 in the intradiscal domain is required for correct folding in vivo and function of mammalian rhodopsin. Misfolding in rhodopsin, characterized by the loss of ability to bind 11-cis-retinal, has been shown to be caused by an intradiscal disulfide bond different from the above native disulfide bond. Further, naturally occurring single mutations of the intradiscal cysteines (C110F, C110Y, and C187Y) are associated with retinitis pigmentosa (RP). To elucidate further the role of every one of the three intradiscal cysteines, mutants containing single-cysteine replacements by alanine residues and the above three RP mutants have been studied. We find that C110A, C110F, and C110Y all form a disulfide bond between C185 and C187 and cause loss of retinal binding. C185A allows the formation of a C110-C187 disulfide bond, with wild-type-like rhodopsin phenotype. C187A forms a disulfide bond between C110 and C185 and binds retinal, and the pigment formed has markedly altered bleaching behavior. However, the opsin from the RP mutant C187Y forms no rhodopsin chromophore. (+info)Specificity of native-like interhelical hydrophobic contacts in the apomyoglobin intermediate. (8/8806)
On exposure to mildly acidic conditions, apomyoglobin forms a partially folded intermediate, I. The A, B, G, and H helices are significantly structured in this equilibrium intermediate, whereas the remainder of the protein is largely unfolded. We report here the effects of mutations at helix pairing sites on the stability of I in three classes of mutants that: (i) truncate hydrophobic side chains in native helix packing sites, (ii) truncate hydrophobic side chains not involved in interhelical contacts, and (iii) extend hydrophobic side chains at residues not involved in interhelical contacts. Class I mutants significantly decrease the stability and cooperativity of folding of the intermediate. Class II and III mutants show smaller effects on stability and have little effect on cooperativity. Qualitatively similar results to those found in I were obtained for all three classes of mutants in native myoglobin (N), demonstrating that hydrophobic burial is fairly specific to native helix packing sites in I as well as in N. These results suggest that hydrophobic burial along native-like interhelical contacts is important for the formation of the cooperatively folded intermediate. (+info) Subarachnoid Hemorrhage: A type of stroke that occurs when there is bleeding in the space surrounding the brain, known as the subarachnoid space. This type of hemorrhage can be caused by a ruptured aneurysm, arteriovenous malformation (AVM), or other blood vessel abnormalities. Symptoms of subarachnoid hemorrhage can include sudden severe headache, nausea and vomiting, confusion, seizures, and loss of consciousness. Prompt medical attention is essential to prevent further brain damage and improve outcomes. Treatment options may include surgery, endovascular coiling, or medication to control symptoms and prevent further bleeding.
Spectrophotometry
Wikimedia Commons has media related to Spectrophotometry. Spectrophotometry Handbook (Articles with short description, Short ... Spectrophotometry is a tool that hinges on the quantitative analysis of molecules depending on how much light is absorbed by ... Samples for IR spectrophotometry may be smeared between two discs of potassium bromide or ground with potassium bromide and ... Largely, spectrophotometry is best used to help quantify the amount of purification your sample has undergone relative to total ...
Micro-spectrophotometry
Fluorescence spectroscopy Infrared spectroscopy Microfluorimetry Raman Microspectrosopy Spectrophotometry Ultraviolet-visible ...
Thorfin R. Hogness
Zscheile, F. P.; Sidwell, A. E. (1937). "Photoelectric Spectrophotometry. An Apparatus for the Ultra-violet and Visible ...
Savitzky-Golay filter
Talsky, Gerhard (1994-10-04). Derivative Spectrophotometry. Wiley. ISBN 978-3527282944. Abbaspour, Abdolkarim; Khajehzadeha, ... "The Analysis of Overlapping Spectral Absorption Bands by Derivative Spectrophotometry". Appl. Spectrosc. 9 (2): 78-96. Bibcode: ...
Xanthochromia
However, recent guidelines suggest that spectrophotometry should be performed. Spectrophotometry relies on the different ... Spectrophotometry can also detect the presence of oxyhemoglobin and methemoglobin, which absorb light at 410-418 nm and 403-410 ... Chu, K; Hann, A; Greenslade, J; Williams, J; Brown, A (Mar 10, 2014). "Spectrophotometry or Visual Inspection to Most Reliably ... There is still disagreement about whether or not to routinely use spectrophotometry or whether visual inspection is adequate, ...
Algol
Fletcher, Emery S. (1964). "Spectrophotometry of Algol". The Astronomical Journal. 69: 357. Bibcode:1964AJ.....69..357F. doi: ...
Forensic colorimetry
doi:10.1016/S0379-0738(96)02038-5. "2.1.5: Spectrophotometry". Chemistry LibreTexts. 2013-10-02. Retrieved 2020-12-26. Murray, ...
Förster resonance energy transfer
ISBN 978-3-527-31555-0. Harris DC (2010). "Applications of Spectrophotometry". Quantitative Chemical Analysis (8th ed.). New ...
Sulfanilic acid
"Colorimetry and Spectrophotometry". Vogel's Textbook of Quantitative Chemical Analysis, 5th Edition. Longman. p. 702. ISBN 0- ...
N-(1-Naphthyl)ethylenediamine
G. H. Jerffery; J. Bassett; J. Mendham; R. C. Denney (1989). "Colorimetry and Spectrophotometry". Vogel's Textbook of ...
Spectronic 20
Morris, Rob (November 2, 2015). "UNIT 2.1 Spectrophotometry". Current Protocols in Essential Laboratory Techniques (Online). ... "Celebrating 50 years of spectrophotometry". Thermo Fisher Scientific (Molecular Spectroscopy). Retrieved 10 December 2003. ...
Reciprocity (photography)
ISBN 978-0-521-77096-5. W. M. H. Greaves (1936). "Time Effects in Spectrophotometry". Monthly Notices of the Royal Astronomical ... 22 (67). Bibcode:1913POPot..67.....K. Loyd A. Jones (July 1927). "Photographic Spectrophotometry in the Ultra-Violet Region". ...
Howard Cary
Described as "famous" it gave the field of Raman spectrophotometry a "tremendous boost" in the United States. Other instruments ... Beckman, A. O.; Gallaway, W. S.; Kaye, W.; Ulrich, W. F. (1977). "History of spectrophotometry at Beckman Instruments, Inc". ... Hind, Andrew R. (December 2002). "To improvements in spectrophotometry. . " (PDF). American Laboratory. 34: 32-35. Retrieved 27 ... use single instrument containing both the optical and electronic components needed for ultraviolet-absorption spectrophotometry ...
Kamenskoe Plateau Observatory
Spectrophotometry of active galaxies. Stellar astronomy. Large planets of the solar system. Comets. AES astrometry. ... spectrophotometry - EK Denisyuk, LN Kondratyeva, RR Valiullin) - was ordered for the Tikhov observatory, but was installed ...
Comet dust
"grains" Newburn, R; Spinrad, H (Dec 1985). "Spectrophotometry of seventeen comets. II - The continuum". Astronomical Journal. ...
Cary 14 Spectrophotometer
Clarke, F. J. J. (June 5, 1972). "High Accuracy Spectrophotometry at the National Physical Laboratory (Teddington, Middlesex, ... Sommer, L. (1989). Analytical absorption spectrophotometry in the visible and ultraviolet : the principles. Amsterdam: Elsevier ... Hind, Andrew R. (December 2002). "To improvements in spectrophotometry. . " (PDF). American Laboratory. 34: 32-35. Retrieved 27 ...
Stopped-flow
Chance, Britton (1951). "Rapid and Sensitive Spectrophotometry. I. The Accelerated and Stopped‐Flow Methods for the Measurement ... Chance, Britton; Legallais, Victor (1951). "Rapid and Sensitive Spectrophotometry. II. A Stopped‐Flow Attachment for a ...
Ultraviolet-visible spectroscopy
If UV/Vis spectrophotometry is used in quantitative chemical analysis then the results are additionally affected by uncertainty ... Samples for UV/Vis spectrophotometry are most often liquids, although the absorbance of gases and even of solids can also be ... "Spectrophotometry Applications and Fundamentals". www.mt.com. Retrieved 10 July 2018. Forensic Fiber Examination Guidelines, ... In addition, ultraviolet-visible spectrophotometry can be used to determine the thickness, along with the refractive index and ...
Crab Nebula
I - Spectrophotometry of the filaments". The Astrophysical Journal. 258 (1): 1-10. Bibcode:1982ApJ...258....1F. doi:10.1086/ ...
Astronomical spectroscopy
... this is known as spectrophotometry. Radio astronomy was founded with the work of Karl Jansky in the early 1930s, while working ...
Cygnus Loop
Fesen RA; Blair WP; Kirshner RP (Nov 1982). "Spectrophotometry of the Cygnus Loop". Astrophys. J. 262 (12): 171-88. Bibcode: ...
Xi2 Ceti
Bessell, Michael S. (1999). "Spectrophotometry: Revised Standards and Techniques". Publications of the Astronomical Society of ...
Know Labs
"About Know Labs". Gail Overton (2013-01-16). "SPECTROPHOTOMETRY: ChromaID scanner challenges traditional spectrophotometry". ...
Quentin Gibson
Gibson, QH; Milnes, L. (1964). "Apparatus for rapid and sensitive spectrophotometry". Biochemical Journal. 91 (1): 161-171. doi ...
AB magnitude
Oke, J. B. (1983). "Secondary standard stars for absolute spectrophotometry". The Astrophysical Journal. 266: 713-717. Bibcode: ...
Aromatic amino acid
Schmid F (April 2001). "Biological Macromolecules: UV‐visible Spectrophotometry" (PDF). Encyclopedia of Life Sciences. ...
WD 1145+017
"Fast spectrophotometry of WD 1145+017". Monthly Notices of the Royal Astronomical Society. 481 (1): 703-714. arXiv:1808.07320. ...
WD 1145+017 b
"Fast spectrophotometry of WD 1145+017". Monthly Notices of the Royal Astronomical Society. 481 (1): 703-714. arXiv:1808.07320. ...
EX Hydrae
"Multi-wavelength spectrophotometry of EX Hydrae". Astronomy & Astrophysics. 382 (3): 984-998. Bibcode:2002A&A...382..984E. doi: ...
Leonard Hanssen
He is an expert in infrared spectrophotometry and integrating sphere design and applications. Hanssen earned B.S. degrees in ... "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 ... He is the project leader for infrared spectrophotometry in the Sensor Science Division of the Physical Measurement Laboratory. ...
D3677 Standard Test Methods for Rubber-Identification by Infrared Spectrophotometry
Standard Test Methods for Rubber-Identification by Infrared Spectrophotometry. Standard Test Methods for Rubber-Identification ... 1.3 Since it is customary in infrared spectrophotometry to use wavenumbers (cm−1) rather than Hertz (Hz), the unit for ... D3677 Standard Test Methods for Rubber-Identification by Infrared Spectrophotometry> new BOS Vol. 09.01 Committee D11 $ 98.00 ... Standard Test Methods for Rubber-Identification by Infrared Spectrophotometry Standard ...
PRIME PubMed | Spectrophotometry of hemoglobin and hemoglobin derivatives
Spectrophotometry of hemoglobin and hemoglobin derivatives. Download Prime PubMed App to iPhone, iPad, or Android ... TY - JOUR T1 - Spectrophotometry of hemoglobin and hemoglobin derivatives. AU - van Kampen,E J, AU - Zijlstra,W G, PY - 1983/1/ ... "Spectrophotometry of Hemoglobin and Hemoglobin Derivatives." Advances in Clinical Chemistry, vol. 23, 1983, pp. 199-257. ... Spectrophotometry of Hemoglobin and Hemoglobin Derivatives. Adv Clin Chem. 1983;23:199-257. PubMed PMID: 6398614. ...
Browsing by Subject "Spectrophotometry, Atomic"
Development of a Spectrophotometry Assay for Arginine, a Precursor to Ethyl - American Vineyard Foundation
Development of a Spectrophotometry Assay for Arginine, a Precursor to Ethyl. AVF Proj. ID: 9711 / Year Posted: 1997. /Cat.: ... The new spectrophotometry assay for arginine utilizes techniques adapted from ion exchange chromatography. In our method ... 50Development of a Spectrophotometry Assay for Arginine, a Precursor to Ethyl. ...
Spectrophotometry from Mars Hand Lens Imager goniometer measurements: Kimberley region, Gale crater<...
Liang, W., Johnson, J. R., Hayes, A. G., Lemmon, M. T., Bell, J. F., Grundy, W. M., & Deen, R. G. (2020). Spectrophotometry ... Spectrophotometry from Mars Hand Lens Imager goniometer measurements: Kimberley region, Gale crater. Icarus. 2020 Jan 1;335: ... Spectrophotometry from Mars Hand Lens Imager goniometer measurements : Kimberley region, Gale crater. In: Icarus. 2020 ; Vol. ... Liang, W, Johnson, JR, Hayes, AG, Lemmon, MT, Bell, JF, Grundy, WM & Deen, RG 2020, Spectrophotometry from Mars Hand Lens ...
Algorithms: Spectrophotometry - SDSS DR7
The spectrophotometry since DR2 is vastly improved compared to DR1, but the final calibrated spectra in DR2 and beyond are not ... The spectrophotometry was tied to the fiber magnitudes of stars, whose relation to the true, PSF magnitudes of stars is seeing- ... Algorithms - Spectrophotometry. Because the SDSS spectra are obtained through 3-arcsecond fibers during non-photometric ... over the survey is 0.034). Users of spectra should note that the fractional improvement in spectrophotometry from DR1 to DR2 ...
Can Bottled Tea Brewing Be Simplified Using Spectrophotometry?
Spectrophotometry service at University of Hawaii at Manoa
Simultaneous determination of compounds in Septalen® pellets by derivative spectrophotometry
second-derivative spectrophotometry / zero-crossing method / method with correction / lidocaine / cetrimonium bromide / ... Simultaneous determination of compounds in Septalen® pellets by derivative spectrophotometry. Određivanje Septalen® pastila ... pellets by derivative spectrophotometry. in Journal of the Serbian Chemical Society Srpsko hemijsko društvo, Beograd., 65(5-6 ... pellets by derivative spectrophotometry T1 - Određivanje Septalen® pastila primenom derivativne spektrofotometrije VL - 65 IS ...
Lab 4 Write up - Spectrophotometry and Dilutions: How much blue
Correction: Quantification of glucose-6-phosphate dehydrogenase activity by spectrophotometry: A systematic review and meta...
Organske snovi v okolju: spremljanje, pretvorbe in učinki • UNG
Chromogen/Metal Indicator DOJINDO LABORATORIES
Center for Nonlinear and Complex Systems at Duke University
Biomedical Science | Bradley University
Simultaneous determination of timolol maleate and latanoprost tartrate in ophthalmic preparations by derivative...
BSc Immunology with Entrepreneurship - course details (2023 entry) | The University of Manchester
Geometry.Net - Science: Electrochemistry
Journal of Research Volume 51 | NIST
A further contribution to the interpretation of the results of the July 31, 1981 prominence eclipse - NASA/ADS
It is shown that the prominence brightness distribution at a wavelength of 1.35 cm is in better agreement with the Ca II-line brightness distribution than with that of the H-alpha line. The prominence was both active and long-lived. It is suggested that shock excitation is the underlying mechanism in the Ca II line, while H-alpha emission involves a radiative mechanism.
NIOSHTIC-2 Search Results - Basic View
Inspection analyzer - All industrial manufacturers
DOC SBIR 2014-NIST-SBIR-01 | SBIR.gov
Frontiers | Variations on primary metabolites of the carrageenan-producing red algae Sarcopeltis skottsbergii from Chile and...
Near infrared (up to 2500 nm) light source for diffuse reflection measurement Diffuse reflection light source L16462-01 |...
Educational Resources | Page 7 | NCBioNetwork.org
Atomic2
- Atomic absorption spectrophotometry was used for copper measurements. (bvsalud.org)
- Lead levels were determined using atomic absorption spectrophotometry. (who.int)
Measurement1
- The L16462-01 is a light source integrating lamps and bundled optical fibers for diffuse reflection measurement in near-infrared spectrophotometry. (hamamatsu.com)
Correction1
- Correction: Quantification of glucose-6-phosphate dehydrogenase activity by spectrophotometry: A systematic review and meta-analysis. (bvsalud.org)
Concentration2
- In general, metal indicators are utilized for chelate titration, and colorimetric and fluorometric chelating agents are utilized for the determination of the metal concentration by spectrophotometry. (dojindo.com)
- concentration of formaldehyde released was quantified using spectrophotometry. (cdc.gov)
Color1
- The objective of this study was to compare different resins and determine their matching color with Vita shade, also investigating the possibility of substitution among them and the correlation between the visual and spectrophotometry methods of color selection. (bvsalud.org)
Types1
- Afin d'étudier l'effet de l'adoucissement de l'eau du robinet (extraction du calcium) sur les colorations à l'hématoxyline et à l'éosine, cinq (5) séries de lames issues de 30 blocs de tissus pathologiques humains différents inclus en paraffine ont été préparées de la même manière, sauf pour le lavage qui a été effectué avec cinq types d'eau différents. (who.int)
General1
- This interactive lesson covers the basics of Spectrophotometry including: a general overview of. (ncbionetwork.org)
Page1
- We have a separate page showing the quality of spectrophotometry in DR6 . (sdss2.org)
Method1
- 1.3 Since it is customary in infrared spectrophotometry to use wavenumbers (cm −1 ) rather than Hertz (Hz), the unit for frequency in the SI system, the former is employed throughout this test method. (astm.org)
Stars1
- The spectrophotometry was tied to the fiber magnitudes of stars, whose relation to the true, PSF magnitudes of stars is seeing-dependent. (sdss2.org)
Fluorescence spectrophotometry1
- Benzo(a)pyrene diolepoxide-DNA adducts detected by synchronous fluorescence spectrophotometry. (nih.gov)
Total1
- 13) Quality and yield of total RNA are determined by spectrophotometry. (nih.gov)