Atomic species differing in mass number but having the same atomic number. (Grant & Hackh's Chemical Dictionary, 5th ed)
Techniques for labeling a substance with a stable or radioactive isotope. It is not used for articles involving labeled substances unless the methods of labeling are substantively discussed. Tracers that may be labeled include chemical substances, cells, or microorganisms.
Stable nitrogen atoms that have the same atomic number as the element nitrogen, but differ in atomic weight. N-15 is a stable nitrogen isotope.
Stable oxygen atoms that have the same atomic number as the element oxygen, but differ in atomic weight. O-17 and 18 are stable oxygen isotopes.
Stable carbon atoms that have the same atomic number as the element carbon, but differ in atomic weight. C-13 is a stable carbon isotope.
Stable zinc atoms that have the same atomic number as the element zinc, but differ in atomic weight. Zn-66-68, and 70 are stable zinc isotopes.
Stable sulfur atoms that have the same atomic number as the element sulfur, but differ in atomic weight. S-33, 34, and 36 are stable sulfur isotopes.
Deuterium. The stable isotope of hydrogen. It has one neutron and one proton in the nucleus.
Stable iron atoms that have the same atomic number as the element iron, but differ in atomic weight. Fe-54, 57, and 58 are stable iron isotopes.
Stable strontium atoms that have the same atomic number as the element strontium, but differ in the atomic weight. Sr-84, 86, 87, and 88 are the stable strontium isotopes.
Method for assessing flow through a system by injection of a known quantity of radionuclide into the system and monitoring its concentration over time at a specific point in the system. (From Dorland, 28th ed)
An analytical method used in determining the identity of a chemical based on its mass using mass analyzers/mass spectrometers.
Methods for assessing flow through a system by injection of a known quantity of an indicator, such as a dye, radionuclide, or chilled liquid, into the system and monitoring its concentration over time at a specific point in the system. (From Dorland, 28th ed)
Stable mercury atoms that have the same atomic number as the element mercury, but differ in atomic weight. Hg-196, 198-201, and 204 are stable mercury isotopes.
A microanalytical technique combining mass spectrometry and gas chromatography for the qualitative as well as quantitative determinations of compounds.
The rate dynamics in chemical or physical systems.
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.
Creation and development of bodies within solar systems, includes study of early planetary geology.
Isotopes that exhibit radioactivity and undergo radioactive decay. (From Grant & Hackh's Chemical Dictionary, 5th ed & McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)
The first chemical element in the periodic table. It has the atomic symbol H, atomic number 1, and atomic weight [1.00784; 1.00811]. It exists, under normal conditions, as a colorless, odorless, tasteless, diatomic gas. Hydrogen ions are PROTONS. Besides the common H1 isotope, hydrogen exists as the stable isotope DEUTERIUM and the unstable, radioactive isotope TRITIUM.
Unstable isotopes of carbon that decay or disintegrate emitting radiation. C atoms with atomic weights 10, 11, and 14-16 are radioactive carbon isotopes.
Chromatographic techniques in which the mobile phase is a liquid.
Unstable isotopes of zinc that decay or disintegrate emitting radiation. Zn atoms with atomic weights 60-63, 65, 69, 71, and 72 are radioactive zinc isotopes.
A mass of organic or inorganic solid fragmented material, or the solid fragment itself, that comes from the weathering of rock and is carried by, suspended in, or dropped by air, water, or ice. It refers also to a mass that is accumulated by any other natural agent and that forms in layers on the earth's surface, such as sand, gravel, silt, mud, fill, or loess. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed, p1689)
Any solid objects moving in interplanetary space that are smaller than a planet or asteroid but larger than a molecule. Meteorites are any meteoroid that has fallen to a planetary surface. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)
A nonmetallic element with atomic symbol C, atomic number 6, and atomic weight [12.0096; 12.0116]. It may occur as several different allotropes including DIAMOND; CHARCOAL; and GRAPHITE; and as SOOT from incompletely burned fuel.
Techniques used to determine the age of materials, based on the content and half-lives of the RADIOACTIVE ISOTOPES they contain.
A mass spectrometry technique using two (MS/MS) or more mass analyzers. With two in tandem, the precursor ions are mass-selected by a first mass analyzer, and focused into a collision region where they are then fragmented into product ions which are then characterized by a second mass analyzer. A variety of techniques are used to separate the compounds, ionize them, and introduce them to the first mass analyzer. For example, for in GC-MS/MS, GAS CHROMATOGRAPHY-MASS SPECTROMETRY is involved in separating relatively small compounds by GAS CHROMATOGRAPHY prior to injecting them into an ionization chamber for the mass selection.
The inanimate matter of Earth, the structures and properties of this matter, and the processes that affect it.
The sequence of transfers of matter and energy from organism to organism in the form of FOOD. Food chains intertwine locally into a food web because most organisms consume more than one type of animal or plant. PLANTS, which convert SOLAR ENERGY to food by PHOTOSYNTHESIS, are the primary food source. In a predator chain, a plant-eating animal is eaten by a larger animal. In a parasite chain, a smaller organism consumes part of a larger host and may itself be parasitized by smaller organisms. In a saprophytic chain, microorganisms live on dead organic matter.
Tritium is an isotope of hydrogen (specifically, hydrogen-3) that contains one proton and two neutrons in its nucleus, making it radioactive with a half-life of about 12.3 years, and is used in various applications including nuclear research, illumination, and dating techniques due to its low energy beta decay.
The systematic study of the complete complement of proteins (PROTEOME) of organisms.
Uptake of substances through the lining of the INTESTINES.
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 gaseous envelope surrounding a planet or similar body. (From Random House Unabridged Dictionary, 2d ed)
The facilitation of a chemical reaction by material (catalyst) that is not consumed by the reaction.
The ash, dust, gases, and lava released by volcanic explosion. The gases are volatile matter composed principally of about 90% water vapor, and carbon dioxide, sulfur dioxide, hydrogen, carbon monoxide, and nitrogen. The ash or dust is pyroclastic ejecta and lava is molten extrusive material consisting mainly of magnesium silicate. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)
The science of the earth and other celestial bodies and their history as recorded in the rocks. It includes the study of geologic processes of an area such as rock formations, weathering and erosion, and sedimentation. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)
Separation of a mixture in successive stages, each stage removing from the mixture some proportion of one of the substances, for example by differential solubility in water-solvent mixtures. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)
Theoretical representations that simulate the behavior or activity of chemical processes or phenomena; includes the use of mathematical equations, computers, and other electronic equipment.
The period of history before 500 of the common era.
An element with the atomic symbol N, atomic number 7, and atomic weight [14.00643; 14.00728]. Nitrogen exists as a diatomic gas and makes up about 78% of the earth's atmosphere by volume. It is a constituent of proteins and nucleic acids and found in all living cells.
Radioactive substances added in minute amounts to the reacting elements or compounds in a chemical process and traced through the process by appropriate detection methods, e.g., Geiger counter. Compounds containing tracers are often said to be tagged or labeled. (Hawley's Condensed Chemical Dictionary, 12th ed)
Bodies preserved either by the ancient Egyptian technique or due to chance under favorable climatic conditions.
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)
Enzymes that catalyze the cleavage of a carbon-carbon bond by means other than hydrolysis or oxidation. This subclass contains the DECARBOXYLASES, the ALDEHYDE-LYASES, and the OXO-ACID-LYASES. EC 4.1.
The study of early forms of life through fossil remains.
The simplest saturated hydrocarbon. It is a colorless, flammable gas, slightly soluble in water. It is one of the chief constituents of natural gas and is formed in the decomposition of organic matter. (Grant & Hackh's Chemical Dictionary, 5th ed)
A great expanse of continuous bodies of salt water which together cover more than 70 percent of the earth's surface. Seas may be partially or entirely enclosed by land, and are smaller than the five oceans (Atlantic, Pacific, Indian, Arctic, and Antarctic).
The physical or physiological processes by which substances, tissue, cells, etc. take up or take in other substances or energy.
A colorless, odorless gas that can be formed by the body and is necessary for the respiration cycle of plants and animals.
A functional system which includes the organisms of a natural community together with their environment. (McGraw Hill Dictionary of Scientific and Technical Terms, 4th ed)
Remains, impressions, or traces of animals or plants of past geological times which have been preserved in the earth's crust.
Periodic movements of animals in response to seasonal changes or reproductive instinct. Hormonal changes are the trigger in at least some animals. Most migrations are made for reasons of climatic change, feeding, or breeding.
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)
The protein complement of an organism coded for by its genome.
Organic compounds that generally contain an amino (-NH2) and a carboxyl (-COOH) group. Twenty alpha-amino acids are the subunits which are polymerized to form proteins.
The salinated water of OCEANS AND SEAS that provides habitat for marine organisms.
The scientific study of past societies through artifacts, fossils, etc.
The group of celestial bodies, including the EARTH, orbiting around and gravitationally bound by the sun. It includes eight planets, one minor planet, and 34 natural satellites, more than 1,000 observed comets, and thousands of lesser bodies known as MINOR PLANETS (asteroids) and METEOROIDS. (From Academic American Encyclopedia, 1983)
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.
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).
Regular course of eating and drinking adopted by a person or animal.
A mass spectrometry technique used for analysis of nonvolatile compounds such as proteins and macromolecules. The technique involves preparing electrically charged droplets from analyte molecules dissolved in solvent. The electrically charged droplets enter a vacuum chamber where the solvent is evaporated. Evaporation of solvent reduces the droplet size, thereby increasing the coulombic repulsion within the droplet. As the charged droplets get smaller, the excess charge within them causes them to disintegrate and release analyte molecules. The volatilized analyte molecules are then analyzed by mass spectrometry.
The extent to which the active ingredient of a drug dosage form becomes available at the site of drug action or in a biological medium believed to reflect accessibility to a site of action.
The first artificially produced element and a radioactive fission product of URANIUM. Technetium has the atomic symbol Tc, atomic number 43, and atomic weight 98.91. All technetium isotopes are radioactive. Technetium 99m (m=metastable) which is the decay product of Molybdenum 99, has a half-life of about 6 hours and is used diagnostically as a radioactive imaging agent. Technetium 99 which is a decay product of technetium 99m, has a half-life of 210,000 years.
The production of an image obtained by cameras that detect the radioactive emissions of an injected radionuclide as it has distributed differentially throughout tissues in the body. The image obtained from a moving detector is called a scan, while the image obtained from a stationary camera device is called a scintiphotograph.
Inorganic compounds that include a positively charged tetrahedral nitrogen (ammonium ion) as part of their structure. This class of compounds includes a broad variety of simple ammonium salts and derivatives.
A research technique to measure solvent exposed regions of molecules that is used to provide insight about PROTEIN CONFORMATION.
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.
Disciplines that apply sciences to law. Forensic sciences include a wide range of disciplines, such as FORENSIC TOXICOLOGY; FORENSIC ANTHROPOLOGY; FORENSIC MEDICINE; FORENSIC DENTISTRY; and others.
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)
Theoretical representations that simulate the behavior or activity of biological processes or diseases. For disease models in living animals, DISEASE MODELS, ANIMAL is available. Biological models include the use of mathematical equations, computers, and other electronic equipment.
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.
Excrement from the INTESTINES, containing unabsorbed solids, waste products, secretions, and BACTERIA of the DIGESTIVE SYSTEM.
Chemical groups containing the covalent sulfur bonds -S-. The sulfur atom can be bound to inorganic or organic moieties.
The deductive study of shape, quantity, and dependence. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)
Measurement and evaluation of the components of substances to be taken as FOOD.
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.
The unconsolidated mineral or organic matter on the surface of the earth that serves as a natural medium for the growth of land plants.
Stable gold atoms that have the same atomic number as the element gold, but differ in atomic weight. Au-197 is a stable isotope.
Unstable isotopes of lead that decay or disintegrate emitting radiation. Pb atoms with atomic weights 194-203, 205, and 209-214 are radioactive lead isotopes.
Liquid chromatographic techniques which feature high inlet pressures, high sensitivity, and high speed.
Planet that is the third in order from the sun. It is one of the four inner or terrestrial planets of the SOLAR SYSTEM.
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.
Uranium. A radioactive element of the actinide series of metals. It has an atomic symbol U, atomic number 92, and atomic weight 238.03. U-235 is used as the fissionable fuel in nuclear weapons and as fuel in nuclear power reactors.
Pollutants, present in water or bodies of water, which exhibit radioactivity.
A series of steps taken in order to conduct research.
The science dealing with the earth and its life, especially the description of land, sea, and air and the distribution of plant and animal life, including humanity and human industries with reference to the mutual relations of these elements. (From Webster, 3d ed)
An essential branched-chain amino acid important for hemoglobin formation.
An extinct genus of large mammals in the family Elephantidae that fed by grazing on low vegetation. Most died out at the end of the last ice age.
Fluids composed mainly of water found within the body.
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.
Inorganic salts of sulfuric acid.
The loss of water vapor by plants to the atmosphere. It occurs mainly from the leaves through pores (stomata) whose primary function is gas exchange. The water is replaced by a continuous column of water moving upwards from the roots within the xylem vessels. (Concise Dictionary of Biology, 1990)
Chemical and physical transformation of the biogenic elements from their nucleosynthesis in stars to their incorporation and subsequent modification in planetary bodies and terrestrial biochemistry. It includes the mechanism of incorporation of biogenic elements into complex molecules and molecular systems, leading up to the origin of life.
Stable potassium atoms that have the same atomic number as the element potassium, but differ in atomic weight. K-41 is a stable potassium isotope.
Unstable isotopes of potassium that decay or disintegrate emitting radiation. K atoms with atomic weights 37, 38, 40, and 42-45 are radioactive potassium isotopes.
Salts or ions of the theoretical carbonic acid, containing the radical CO2(3-). Carbonates are readily decomposed by acids. The carbonates of the alkali metals are water-soluble; all others are insoluble. (From Grant & Hackh's Chemical Dictionary, 5th ed)
Radiographic visualization of the cerebral ventricles by injection of air or other gas.
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 large lobed glandular organ in the abdomen of vertebrates that is responsible for detoxification, metabolism, synthesis and storage of various substances.
Benzoate derivatives that contain one or more alkyl or aryl groups linked to the benzene ring structure by OXYGEN.
A characteristic feature of enzyme activity in relation to the kind of substrate on which the enzyme or catalytic molecule reacts.
Elements of limited time intervals, contributing to particular results or situations.
Derivatives of ACETIC ACID. Included under this heading are a broad variety of acid forms, salts, esters, and amides that contain the carboxymethane structure.
Unstable isotopes of selenium that decay or disintegrate emitting radiation. Se atoms with atomic weights 70-73, 75, 79, 81, and 83-85 are radioactive selenium isotopes.
Events and activities of the Earth and its structures.
The facilitation of biochemical reactions with the aid of naturally occurring catalysts such as ENZYMES.
The dimension of the physical universe which, at a given place, orders the sequence of events. (McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)
An element that is a member of the chalcogen family. It has an atomic symbol S, atomic number 16, and atomic weight [32.059; 32.076]. It is found in the amino acids cysteine and methionine.
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 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.
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)
I'm sorry for any confusion, but the term "Pacific Ocean" is a geographical term referring to the largest ocean in the world, covering an area of about 63,800,000 square miles (165,200,000 square kilometers), and it is not a medical term.
Stable iodine atoms that have the same atomic number as the element iodine, but differ in atomic weight. I-127 is the only naturally occurring stable iodine isotope.
Stable gallium atoms that have the same atomic number as the element gallium, but differ in atomic weight. Ga-71 is a stable gallium isotope.
The branch of science concerned with the interrelationship of organisms and their ENVIRONMENT, especially as manifested by natural cycles and rhythms, community development and structure, interactions between different kinds of organisms, geographic distributions, and population alterations. (Webster's, 3d ed)
The synthesis by organisms of organic chemical compounds, especially carbohydrates, from carbon dioxide using energy obtained from light rather than from the oxidation of chemical compounds. Photosynthesis comprises two separate processes: the light reactions and the dark reactions. In higher plants; GREEN ALGAE; and CYANOBACTERIA; NADPH and ATP formed by the light reactions drive the dark reactions which result in the fixation of carbon dioxide. (from Oxford Dictionary of Biochemistry and Molecular Biology, 2001)
A widely used industrial solvent.
Stable phosphorus atoms that have the same atomic number as the element phosphorus, but differ in atomic weight. P-31 is a stable phosphorus isotope.
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.
Dysprosium. An element of the rare earth family that has the atomic symbol Dy, atomic number 66, and atomic weight 162.50. Dysprosium is a silvery metal used primarily in the form of various salts.
The longterm manifestations of WEATHER. (McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)
Activation analysis in which the specimen is bombarded with neutrons. Identification is made by measuring the resulting radioisotopes. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)
NMR spectroscopy on small- to medium-size biological macromolecules. This is often used for structural investigation of proteins and nucleic acids, and often involves more than one isotope.
One of a set of bone-like structures in the mouth used for biting and chewing.
A primary source of energy for living organisms. It is naturally occurring and is found in fruits and other parts of plants in its free state. It is used therapeutically in fluid and nutrient replacement.
Measurement of cells' substrate utilization and biosynthetic output for modeling of METABOLIC NETWORKS.
The phenomenon whereby compounds whose molecules have the same number and kind of atoms and the same atomic arrangement, but differ in their spatial relationships. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 5th ed)
Elimination of ENVIRONMENTAL POLLUTANTS; PESTICIDES and other waste using living organisms, usually involving intervention of environmental or sanitation engineers.
Water containing no significant amounts of salts, such as water from RIVERS and LAKES.
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.
Linear POLYPEPTIDES that are synthesized on RIBOSOMES and may be further modified, crosslinked, cleaved, or assembled into complex proteins with several subunits. The specific sequence of AMINO ACIDS determines the shape the polypeptide will take, during PROTEIN FOLDING, and the function of the protein.
A soft, grayish metal with poisonous salts; atomic number 82, atomic weight 207.19, symbol Pb. (Dorland, 28th)
A metallic element, atomic number 49, atomic weight 114.82, symbol In. It is named from its blue line in the spectrum. (From Dorland, 28th ed)
The systematic identification and quantitation of all the metabolic products of a cell, tissue, organ, or organism under varying conditions. The METABOLOME of a cell or organism is a dynamic collection of metabolites which represent its net response to current conditions.
One of the three domains of life (the others being Eukarya and ARCHAEA), also called Eubacteria. They are unicellular prokaryotic microorganisms which generally possess rigid cell walls, multiply by cell division, and exhibit three principal forms: round or coccal, rodlike or bacillary, and spiral or spirochetal. Bacteria can be classified by their response to OXYGEN: aerobic, anaerobic, or facultatively anaerobic; by the mode by which they obtain their energy: chemotrophy (via chemical reaction) or PHOTOTROPHY (via light reaction); for chemotrophs by their source of chemical energy: CHEMOLITHOTROPHY (from inorganic compounds) or chemoorganotrophy (from organic compounds); and by their source for CARBON; NITROGEN; etc.; HETEROTROPHY (from organic sources) or AUTOTROPHY (from CARBON DIOXIDE). They can also be classified by whether or not they stain (based on the structure of their CELL WALLS) with CRYSTAL VIOLET dye: gram-negative or gram-positive.
Complexing agent for removal of traces of heavy metal ions. It acts also as a hypocalcemic agent.
Behavioral responses or sequences associated with eating including modes of feeding, rhythmic patterns of eating, and time intervals.
Stable yttrium atoms that have the same atomic number as the element yttrium, but differ in atomic weight. Y-89 is the only naturally occurring stable isotope of yttrium.
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.
Multicellular, eukaryotic life forms of kingdom Plantae (sensu lato), comprising the VIRIDIPLANTAE; RHODOPHYTA; and GLAUCOPHYTA; all of which acquired chloroplasts by direct endosymbiosis of CYANOBACTERIA. They are characterized by a mainly photosynthetic mode of nutrition; essentially unlimited growth at localized regions of cell divisions (MERISTEMS); cellulose within cells providing rigidity; the absence of organs of locomotion; absence of nervous and sensory systems; and an alternation of haploid and diploid generations.
Unstable isotopes of iodine that decay or disintegrate emitting radiation. I atoms with atomic weights 117-139, except I 127, are radioactive iodine isotopes.
Actinium. A trivalent radioactive element and the prototypical member of the actinide family. It has the atomic symbol Ac, atomic number 89, and atomic weight 227.0278. Its principal isotope is 227 and decays primarily by beta-emission.
An essential aromatic amino acid that is a precursor of MELANIN; DOPAMINE; noradrenalin (NOREPINEPHRINE), and THYROXINE.
Unstable isotopes of strontium that decay or disintegrate spontaneously emitting radiation. Sr 80-83, 85, and 89-95 are radioactive strontium isotopes.
Unstable isotopes of chromium that decay or disintegrate emitting radiation. Cr atoms with atomic weights of 46-49, 51, 55, and 56 are radioactive chromium isotopes.
Plutonium. A naturally radioactive element of the actinide metals series. It has the atomic symbol Pu, atomic number 94, and atomic weight 242. Plutonium is used as a nuclear fuel, to produce radioisotopes for research, in radionuclide batteries for pacemakers, and as the agent of fission in nuclear weapons.
The fourth planet in order from the sun. Its two natural satellites are Deimos and Phobos. It is one of the four inner or terrestrial planets of the solar system.
A plant genus of the family FABACEAE. Canavalia ensiformis is the source of CONCANAVALIN A.
Members of the class of compounds composed of AMINO ACIDS joined together by peptide bonds between adjacent amino acids into linear, branched or cyclical structures. OLIGOPEPTIDES are composed of approximately 2-12 amino acids. Polypeptides are composed of approximately 13 or more amino acids. PROTEINS are linear polypeptides that are normally synthesized on RIBOSOMES.
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.
Eating of excrement by animal species.

Impact of 9-(2-phosphonylmethoxyethyl)adenine on (deoxy)ribonucleotide metabolism and nucleic acid synthesis in tumor cells. (1/3036)

Following exposure to 9-(2-phosphonylmethoxyethyl)adenine (an inhibitor of the cellular DNA polymerases alpha, delta and epsilon), human erythroleukemia K562, human T-lymphoid CEM and murine leukemia L1210 cells markedly accumulated in the S phase of the cell cycle. In contrast to DNA replication, RNA synthesis (transcription) and protein synthesis (mRNA translation) were not affected by 9-(2-phosphonylmethoxyethyl)-adenine. The ribonucleoside triphosphate pools were slightly elevated, while the intracellular levels of all four deoxyribonucleoside triphosphates were 1.5-4-fold increased in 9-(2-phosphonylmethoxyethyl)adenine-treated K562, CEM and L1210 cells. The effect of 9-(2-phosphonylmethoxyethyl)adenine on de novo (thymidylate synthase-mediated) and salvage (thymidine kinase-mediated) dTTP synthesis was investigated using radio-labelled nucleoside precursors. The amount of thymidylate synthase-derived dTTP in the acid soluble pool was 2-4-fold higher in PMEA-treated than in untreated K562 cells, which is in accord with the 3-4-fold expansion of the global dTTP level in the presence of 9-(2-phosphonylmethoxyethyl)adenine. Strikingly, 2-derived dTTP accumulated to a much higher extent (i.e. 16-40-fold) in the soluble dTTP pool upon 9-(2-phosphonylmethoxyethyl)adenine treatment. In keeping with this finding, a markedly increased thymidine kinase activity could be demonstrated in extracts of 9-(2-phosphonylmethoxyethyl)adenine-treated K562 cell cultures. Also, in the presence of 200 microM 9-(2-phosphonylmethoxyethyl)adenine, 14-fold less thymidylate synthase-derived but only 3-fold less thymidine kinase-derived dTTP was incorporated into the DNA of the K562 cells. These data show that thymidine incorporation may be inappropriate as a cell proliferation marker in the presence of DNA synthesis inhibitors such as 9-(2-phosphonylmethoxyethyl)adenine. Our findings indicate that 9-(2-phosphonylmethoxyethyl)adenine causes a peculiar pattern of (deoxy)ribonucleotide metabolism deregulation in drug-treated tumor cells, as a result of the metabolic block imposed by the drug on the S phase of the cell cycle.  (+info)

Transfer of the 1-pro-R and the 1-pro-S hydrogen atoms of ethanol in metabolic reductions in vivo. (2/3036)

The transfer of deuterium from [1 R-2H]ethanol and [1 S-2H]-ethanol to reduced metabolites of administered compounds was measured in female rats provided with bile fistulas. Administered cyclohexanone was reduced to cyclohexanol, and in this reduction hydrogen was transferred only from the 1-pro-R position of the ethanol. The deuterium content in the cyclohexanol was about 67% of that in the ethanol. In the reduction of the 17-oxo group in 3beta-hydroxy-5alpha-androstan-17-one, hydrogen was transferred both from the 1-pro-R position and the 1-pro-S position, resulting in degrees of labelling that were about 25% and 2%, respectively, of those in the specific positions of the ethanols. The 1-pro-R and 1-pro-S positions of ethanol contributed about 9% and 5%, respectively, of the 3beta hydrogen in lithocholic acid formed from 3-oxo-5beta-cholanoic acid. The results indicate that alcohol dehydrogenase and aldehyde dehydrogenase do not share a common pool of NAD, and that NADH formed during acetaldehyde oxidation is utilized for reductions in the cytosol to a smaller extent than the NADH formed in the alcohol dehydrogenase reaction. This result supports the concept that aldehyde oxidation is mainly an intramitochondrial process. The relatively extensive utilization of the 1-pro-S hydrogen of ethanol in the reduction of 3-oxo-5beta-cholanoic acid, that is probably NADPH-dependent, indicates that cytosolic NADPH may be produced from malate or isocitrate formed intramitochondrially.  (+info)

Kinetics of thyroglobulin iodination and of hormone synthesis catalysed by thyroid peroxidase. Role of iodide in the coupling reaction. (3/3036)

The kinetics of tyrosine iodination and of thyroxine synthesis in thyroglobulin, different reactions catalyzed by the same enzyme (thyroid peroxidase), have been compared. Thyroxine synthesis always began after a lag period of 3-5 min. This lag was constant whatever the rate of iodination; this rate of iodination was increased either by increasing the concentration of iodide or enzyme or by decreasing the concentration of thyroglobulin. Increasing the rate of iodination resulted in increasing the number of iodine atoms incorporated during the lag period. Thus the lag observed for thyroxine synthesis was constant and did not depend on the fact that free iodide or non-iodinated tyrosine residues of thyroglobulin were exhausted before thyroxine synthesis occurred. Finally, it appeared that, whatever the explanation of the lag, the enzyme catlyzes thyroid hormone synthesis at a slower rate than iodination. The existence of a lag also allowed us to prepare thyroglobulin samples with different iodine contents but without thyroid hormones. Thus iodination and thyroxine synthesis could be studied independently and the following results were obtained. 1. Iodotyrosine residues which can couple to form thytoxine are made considerably before coupling occurs. 2. H2O2 is required for coupling of these hormonogenic residues; thus the coupling reaction requires enzymic oxidation of the iodotyrosine residues. 3. In addition a strict requirement for iodide was needed for coupling; the requirement was dependent on the concentration of iodide. Thus iodide, a substrate of the iodination reaction, may also have other effects on the activity of thyroid peroxidase.  (+info)

Quantitative determination of N-acetylglucosamine residues at the non-reducing ends of peptidoglycan chains by enzymic attachment of [14C]-D-galactose. (4/3036)

The ability of human milk galactosyltransferase to attach D-galactose residues quantitatively to the C-4 of N-acetylglucosamine moieties at the ends of oligosaccharides has been utilized for the specific labeling and quantitative determination of the chain length of the glycan moiety of the bacterial cell wall. The average polysaccharide chain length of the soluble, uncrosslinked peptidoglycan secreted by Micrococcus luteus cells on incubation with penicillin G was studied with this technique and found to be approximately 70 hexosamines long. Furthermore, the peptidoglycan chain length of Escherichia coli sacculi of different cell shapes and dimensions was determined both in rod-shaped cells and in filaments induced by temperature shift of a division mutant or by addition of cephalexin or nalidixic acid. The average chain length found in most of these sacculi was between 70 and 100 hexosamines long. Small spherical 'mini' cells had chain lengths similar to those of the isogenic rod-like cells.  (+info)

Radioactive labelling of ribosomal proteins with reductive alkylation and its use in studying ribosome-cytosol interactions. (5/3036)

Mouse brain ribosomes were radioactively labelled by a cell-free reductive alkylation reaction with NaBH4 and [14C]formaldehyde. The radioactivity was largely associated with ribosomal proteins, but little, if any, of the rRNA was radioactive after the alkylation procedure. Both ribosomal structural proteins and loosely associated components were successfully labelled by this procedure. The sedimentation properties of the ribosomes were unaltered and their ability to carry out poly(U)-directed protein synthesis, although decreased, was largely retained. Incubation of 14C-labelled ribosomes with brain cytosol resulted in a 17% loss of radioactivity, although treatment of the ribosomes with 1.0 m-KCl to remove the loosely associated factors rendered the ribonucleoprotein particles resistant to cytosol effects. The ribosome-cytosol interactions did not appear to be related to an exchange process, since the released radioactivity was largely degraded to acid-soluble material. In addition, the incubation of native ribosomes with brain cytosol resulted in an almost complete loss in the ability of the ribosomes to participate in cell-free protein synthesis.  (+info)

Intratumoral distribution of two consecutive injections of chimeric antibody G250 in primary renal cell carcinoma: implications for fractionated dose radioimmunotherapy. (6/3036)

Tumor uptake of the chimeric G250 (cG250) monoclonal antibody (mAb) in patients with primary renal cell carcinoma (RCC) is among the highest reported in solid tumors. However, as observed in other tumor types, the intratumoral distribution of the antibody is highly heterogeneous, which may limit the efficacy of radioimmunotherapy. A number of highly dynamic physiological factors have been postulated that may contribute to heterogeneous tumor uptake of antibodies. Their impact on tumor uptake of antibodies may vary from one tumor region to another as well as from one day to the next. Here, we report on a clinical study that was designed to investigate whether the pattern of mAb cG250 uptake within RCC tumors is altered with subsequent injections. Ten patients with a clinical diagnosis of primary RCC were studied. Nine days before surgery, patients received 125I-cG250 (5 mg of cG250, 50 microCi of 125I), followed by a second injection of 131I-cG250 (5 mg of cG250, 3.5 mCi of 131I) 4 days later. Postsurgery, the tumor was cut into (1-cm) thick slices. Slices were imaged on a gamma camera, and the slice with the most pronounced heterogeneity in 131I-cG250 distribution was selected and cut into 1-cm3 cubes. Each cube was analyzed for 121I-cG250 and 131I-cG250 uptake, and the 131I/125I ratio was determined. For each tumor slice, the distribution patterns of both isotopes were reconstructed and compared with each other. All tumors analyzed showed a heterogeneous distribution of both isotopes throughout the tumor slice; focal uptake in some areas of a tumor reached very high levels (up to 0.19% injected dose/g), whereas other tumorous areas of the same slice showed much lower uptake (as low as 0.0047% injected dose/g). Remarkably, in all tumors, the distribution pattern of both injections was identical: without exception, in all samples analyzed (n = 692), the uptake of 125I-cG250 was similar to 131I-cG250 uptake. Overall, the 131I/125I ratio was 1.64+/-0.31 (mean+/-SD). The constant 131I/125I ratios, observed in all tumor samples investigated, indicate that the tumor parameters governing cG250 mAb uptake were not altered significantly within the time period studied. In addition, the results of this study suggest that multiple radiolabeled antibody injections, administered within short time periods, will target the same areas within a tumor and, thus, will not solve the problem of heterogeneous tumor uptake of antibody.  (+info)

Structures of the M2 channel-lining segments from nicotinic acetylcholine and NMDA receptors by NMR spectroscopy. (7/3036)

The structures of functional peptides corresponding to the predicted channel-lining M2 segments of the nicotinic acetylcholine receptor (AChR) and of a glutamate receptor of the NMDA subtype (NMDAR) were determined using solution NMR experiments on micelle samples, and solid-state NMR experiments on bilayer samples. Both M2 segments form straight transmembrane alpha-helices with no kinks. The AChR M2 peptide inserts in the lipid bilayer at an angle of 12 degrees relative to the bilayer normal, with a rotation about the helix long axis such that the polar residues face the N-terminal side of the membrane, which is assigned to be intracellular. A model built from these solid-state NMR data, and assuming a symmetric pentameric arrangement of M2 helices, results in a funnel-like architecture for the channel, with the wide opening on the N-terminal intracellular side.  (+info)

15N-labelling and preliminary heteronuclear NMR study of Desulfovibrio vulgaris Hildenborough cytochrome c553. (8/3036)

When using heteronuclear NMR, 15N-labelling is necessary for structural analysis, dynamic studies and determination of complex formation. The problems that arise with isotopic labelling of metalloproteins are due to their complex maturation process, which involves a large number of factors. Cytochromes c are poorly expressed in Escherichia coli and the overexpression that is necessary for 15N-labelling, requires an investigation of the expression host and special attention to growth conditions. We have succeeded in the heterologous expression and the complete and uniform isotopic 15N-labelling of the cytochrome c553 from Desulfovibrio vulgaris Hildenborough, in a sulphate-reducing bacterium, D. desulfuricans G200, by using a growth medium combining 15N-ammonium chloride and 15N-Celtone. These conditions allowed us to obtain approximately 0.8 mg x L-1 of pure labelled cytochrome c553. 1H and 15N-assignments for both the oxidized and the reduced states of cytochrome c553 were obtained from two-dimensional heteronuclear experiments. Pseudocontact effects due to the haem Fe3+ have been analysed for the first time through 15N and 1H chemical shifts in a c-type cytochrome.  (+info)

Isotopes are variants of a chemical element that have the same number of protons in their atomic nucleus, but a different number of neutrons. This means they have different atomic masses, but share similar chemical properties. Some isotopes are stable and do not decay naturally, while others are unstable and radioactive, undergoing radioactive decay and emitting radiation in the process. These radioisotopes are often used in medical imaging and treatment procedures.

Isotope labeling is a scientific technique used in the field of medicine, particularly in molecular biology, chemistry, and pharmacology. It involves replacing one or more atoms in a molecule with a radioactive or stable isotope of the same element. This modified molecule can then be traced and analyzed to study its structure, function, metabolism, or interaction with other molecules within biological systems.

Radioisotope labeling uses unstable radioactive isotopes that emit radiation, allowing for detection and quantification of the labeled molecule using various imaging techniques, such as positron emission tomography (PET) or single-photon emission computed tomography (SPECT). This approach is particularly useful in tracking the distribution and metabolism of drugs, hormones, or other biomolecules in living organisms.

Stable isotope labeling, on the other hand, employs non-radioactive isotopes that do not emit radiation. These isotopes have different atomic masses compared to their natural counterparts and can be detected using mass spectrometry. Stable isotope labeling is often used in metabolic studies, protein turnover analysis, or for identifying the origin of specific molecules within complex biological samples.

In summary, isotope labeling is a versatile tool in medical research that enables researchers to investigate various aspects of molecular behavior and interactions within biological systems.

Nitrogen isotopes are different forms of the nitrogen element (N), which have varying numbers of neutrons in their atomic nuclei. The most common nitrogen isotope is N-14, which contains 7 protons and 7 neutrons in its nucleus. However, there are also heavier stable isotopes such as N-15, which contains one extra neutron.

In medical terms, nitrogen isotopes can be used in research and diagnostic procedures to study various biological processes. For example, N-15 can be used in a technique called "nitrogen-15 nuclear magnetic resonance (NMR) spectroscopy" to investigate the metabolism of nitrogen-containing compounds in the body. Additionally, stable isotope labeling with nitrogen-15 has been used in clinical trials and research studies to track the fate of drugs and nutrients in the body.

In some cases, radioactive nitrogen isotopes such as N-13 or N-16 may also be used in medical imaging techniques like positron emission tomography (PET) scans to visualize and diagnose various diseases and conditions. However, these applications are less common than the use of stable nitrogen isotopes.

Oxygen isotopes are different forms or varieties of the element oxygen that have the same number of protons in their atomic nuclei, which is 8, but a different number of neutrons. The most common oxygen isotopes are oxygen-16 (^{16}O), which contains 8 protons and 8 neutrons, and oxygen-18 (^{18}O), which contains 8 protons and 10 neutrons.

The ratio of these oxygen isotopes can vary in different substances, such as water molecules, and can provide valuable information about the origins and history of those substances. For example, scientists can use the ratio of oxygen-18 to oxygen-16 in ancient ice cores or fossilized bones to learn about past climate conditions or the diets of ancient organisms.

In medical contexts, oxygen isotopes may be used in diagnostic tests or treatments, such as positron emission tomography (PET) scans, where a radioactive isotope of oxygen (such as oxygen-15) is introduced into the body and emits positrons that can be detected by specialized equipment to create detailed images of internal structures.

Carbon isotopes are variants of the chemical element carbon that have different numbers of neutrons in their atomic nuclei. The most common and stable isotope of carbon is carbon-12 (^{12}C), which contains six protons and six neutrons. However, carbon can also come in other forms, known as isotopes, which contain different numbers of neutrons.

Carbon-13 (^{13}C) is a stable isotope of carbon that contains seven neutrons in its nucleus. It makes up about 1.1% of all carbon found on Earth and is used in various scientific applications, such as in tracing the metabolic pathways of organisms or in studying the age of fossilized materials.

Carbon-14 (^{14}C), also known as radiocarbon, is a radioactive isotope of carbon that contains eight neutrons in its nucleus. It is produced naturally in the atmosphere through the interaction of cosmic rays with nitrogen gas. Carbon-14 has a half-life of about 5,730 years, which makes it useful for dating organic materials, such as archaeological artifacts or fossils, up to around 60,000 years old.

Carbon isotopes are important in many scientific fields, including geology, biology, and medicine, and are used in a variety of applications, from studying the Earth's climate history to diagnosing medical conditions.

Zinc isotopes refer to variants of the chemical element zinc, each with a different number of neutrons in their atomic nucleus. Zinc has five stable isotopes: zinc-64, zinc-66, zinc-67, zinc-68, and zinc-70. These isotopes have naturally occurring abundances that vary, with zinc-64 being the most abundant at approximately 48.6%.

Additionally, there are also several radioactive isotopes of zinc, including zinc-65, zinc-71, and zinc-72, among others. These isotopes have unstable nuclei that decay over time, emitting radiation in the process. They are not found naturally on Earth and must be produced artificially through nuclear reactions.

Medical Definition: Zinc isotopes refer to variants of the chemical element zinc with different numbers of neutrons in their atomic nucleus, including stable isotopes such as zinc-64, zinc-66, zinc-67, zinc-68, and zinc-70, and radioactive isotopes such as zinc-65, zinc-71, and zinc-72.

Sulfur isotopes are different forms of the chemical element sulfur, each with a distinct number of neutrons in their atomic nuclei. The most common sulfur isotopes are sulfur-32 (with 16 neutrons) and sulfur-34 (with 18 neutrons). These isotopes have similar chemical properties but different atomic masses, which can be used to trace the movement and cycling of sulfur through various environmental processes, such as volcanic emissions, bacterial metabolism, and fossil fuel combustion. The relative abundances of sulfur isotopes can also provide information about the origins and history of sulfur-containing minerals and compounds.

Deuterium is a stable and non-radioactive isotope of hydrogen. The atomic nucleus of deuterium, called a deuteron, contains one proton and one neutron, giving it an atomic weight of approximately 2.014 atomic mass units (amu). It is also known as heavy hydrogen or heavy water because its hydrogen atoms contain one neutron in addition to the usual one proton found in common hydrogen atoms.

Deuterium occurs naturally in trace amounts in water and other organic compounds, typically making up about 0.015% to 0.018% of all hydrogen atoms. It can be separated from regular hydrogen through various methods such as electrolysis or distillation, and it has many applications in scientific research, particularly in the fields of chemistry and physics.

In medical contexts, deuterium is sometimes used as a tracer to study metabolic processes in the body. By replacing hydrogen atoms in specific molecules with deuterium atoms, researchers can track the movement and transformation of those molecules within living organisms. This technique has been used to investigate various physiological processes, including drug metabolism, energy production, and lipid synthesis.

I must clarify that "Iron Isotopes" is not a medical term, but rather a scientific concept from the field of physics and chemistry. However, I can certainly provide a general explanation of isotopes and then focus on iron isotopes specifically.

An isotope is a variant of a chemical element that has the same number of protons (and thus the same atomic number) but a different number of neutrons within its nucleus. This results in variations of the atomic mass of isotopes of the same element. Some isotopes are stable, while others are unstable and will decay over time into other elements or isotopes, a process called radioactive decay.

Iron (Fe) has four naturally occurring stable isotopes: Fe-54, Fe-56, Fe-57, and Fe-58. These iron isotopes have different numbers of neutrons in their nuclei, resulting in slightly different atomic masses. The most abundant iron isotope is Fe-56, which contains 26 protons and 30 neutrons in its nucleus.

In the context of human health, iron is an essential nutrient that plays a crucial role in various biological processes, such as oxygen transport and energy production. However, the concept of iron isotopes does not have a direct medical relevance, but it can be useful in scientific research related to fields like geochemistry, environmental science, or nuclear physics.

Strontium isotopes are different forms of the element strontium that have different numbers of neutrons in their atomic nuclei. The most common strontium isotopes are Sr-84, Sr-86, Sr-87, and Sr-88, with atomic masses of 83.913, 85.909, 86.909, and 87.905 atomic mass units (amu), respectively.

Strontium-87 is a radioactive isotope that is produced naturally in the Earth's crust through the decay of rubidium-87. The ratio of strontium-87 to strontium-86 can be used as a geological dating tool, as well as a forensic tool for determining the origin of objects or materials.

In medical applications, strontium ranelate, which contains stable strontium isotopes, has been used in the treatment of osteoporosis due to its ability to increase bone density and reduce the risk of fractures. However, its use has been limited due to concerns about potential side effects, including cardiovascular risks.

The Radioisotope Dilution Technique is a method used in nuclear medicine to measure the volume and flow rate of a particular fluid in the body. It involves introducing a known amount of a radioactive isotope, or radioisotope, into the fluid, such as blood. The isotope mixes with the fluid, and samples are then taken from the fluid at various time points.

By measuring the concentration of the radioisotope in each sample, it is possible to calculate the total volume of the fluid based on the amount of the isotope introduced and the dilution factor. The flow rate can also be calculated by measuring the concentration of the isotope over time and using the formula:

Flow rate = Volume/Time

This technique is commonly used in medical research and clinical settings to measure cardiac output, cerebral blood flow, and renal function, among other applications. It is a safe and reliable method that has been widely used for many years. However, it does require the use of radioactive materials and specialized equipment, so it should only be performed by trained medical professionals in appropriate facilities.

Mass spectrometry (MS) is an analytical technique used to identify and quantify the chemical components of a mixture or compound. It works by ionizing the sample, generating charged molecules or fragments, and then measuring their mass-to-charge ratio in a vacuum. The resulting mass spectrum provides information about the molecular weight and structure of the analytes, allowing for identification and characterization.

In simpler terms, mass spectrometry is a method used to determine what chemicals are present in a sample and in what quantities, by converting the chemicals into ions, measuring their masses, and generating a spectrum that shows the relative abundances of each ion type.

Indicator dilution techniques are a group of methods used in medicine and research to measure various physiological variables, such as cardiac output or cerebral blood flow. These techniques involve introducing a known quantity of an indicator substance (like a dye or a radioactive tracer) into the system being studied and then measuring its concentration over time at a specific location downstream.

The basic principle behind these techniques is that the concentration of the indicator substance will be inversely proportional to the flow rate of the fluid through which it is moving. By measuring the concentration of the indicator substance at different points in time, researchers can calculate the flow rate using mathematical formulas.

Indicator dilution techniques are widely used in clinical and research settings because they are relatively non-invasive and can provide accurate and reliable measurements of various physiological variables. Some common examples of indicator dilution techniques include thermodilution, dye dilution, and Fick principle-based methods.

Mercury isotopes refer to variants of the chemical element mercury (Hg) that have different numbers of neutrons in their atomic nuclei. This means that while all mercury isotopes have 80 protons in their nucleus, they can have different numbers of neutrons, ranging from 120 to 124 or more.

The most common and stable mercury isotope is Hg-202, which has 80 protons and 122 neutrons. However, there are several other mercury isotopes that occur naturally in trace amounts, including Hg-196, Hg-198, Hg-199, Hg-200, and Hg-204.

Mercury isotopes can also be produced artificially through various nuclear reactions. These isotopes may have different physical and chemical properties than the more common mercury isotopes, which can make them useful for a variety of applications, such as in medical imaging or environmental monitoring. However, some mercury isotopes are radioactive and can be hazardous to handle or dispose of improperly.

Gas Chromatography-Mass Spectrometry (GC-MS) is a powerful analytical technique that combines the separating power of gas chromatography with the identification capabilities of mass spectrometry. This method is used to separate, identify, and quantify different components in complex mixtures.

In GC-MS, the mixture is first vaporized and carried through a long, narrow column by an inert gas (carrier gas). The various components in the mixture interact differently with the stationary phase inside the column, leading to their separation based on their partition coefficients between the mobile and stationary phases. As each component elutes from the column, it is then introduced into the mass spectrometer for analysis.

The mass spectrometer ionizes the sample, breaks it down into smaller fragments, and measures the mass-to-charge ratio of these fragments. This information is used to generate a mass spectrum, which serves as a unique "fingerprint" for each compound. By comparing the generated mass spectra with reference libraries or known standards, analysts can identify and quantify the components present in the original mixture.

GC-MS has wide applications in various fields such as forensics, environmental analysis, drug testing, and research laboratories due to its high sensitivity, specificity, and ability to analyze volatile and semi-volatile compounds.

In the context of medicine and pharmacology, "kinetics" refers to the study of how a drug moves throughout the body, including its absorption, distribution, metabolism, and excretion (often abbreviated as ADME). This field is called "pharmacokinetics."

1. Absorption: This is the process of a drug moving from its site of administration into the bloodstream. Factors such as the route of administration (e.g., oral, intravenous, etc.), formulation, and individual physiological differences can affect absorption.

2. Distribution: Once a drug is in the bloodstream, it gets distributed throughout the body to various tissues and organs. This process is influenced by factors like blood flow, protein binding, and lipid solubility of the drug.

3. Metabolism: Drugs are often chemically modified in the body, typically in the liver, through processes known as metabolism. These changes can lead to the formation of active or inactive metabolites, which may then be further distributed, excreted, or undergo additional metabolic transformations.

4. Excretion: This is the process by which drugs and their metabolites are eliminated from the body, primarily through the kidneys (urine) and the liver (bile).

Understanding the kinetics of a drug is crucial for determining its optimal dosing regimen, potential interactions with other medications or foods, and any necessary adjustments for special populations like pediatric or geriatric patients, or those with impaired renal or hepatic function.

Deuterium oxide, also known as heavy water, is a compound consisting of two atoms of deuterium (a heavy isotope of hydrogen) and one atom of oxygen. Its chemical formula is D2O. Deuterium oxide has physical and chemical properties similar to those of regular water (H2O), but its density and boiling point are slightly higher due to the increased atomic weight. It is used in various scientific research applications, including as a tracer in biochemical and medical studies.

Planetary evolution is a field of study that focuses on the processes that have shaped the formation, development, and changes of planets and other celestial bodies over time. This encompasses various scientific disciplines, including astronomy, astrobiology, geology, and atmospheric science. The study of planetary evolution helps scientists understand how planets form, how they change over time, and the conditions that allow for the development of life.

The process of planetary evolution can be driven by a variety of factors, including:

1. Formation: Planets form from a protoplanetary disk, a rotating disk of gas and dust surrounding a young star. Over time, solid particles in the disk collide and stick together to form larger and larger bodies, eventually leading to the formation of planets.
2. Internal differentiation: As planets grow, their interiors differentiate into layers based on density, with heavier materials sinking towards the center and lighter materials rising towards the surface. This process can lead to the formation of a core, mantle, and crust.
3. Geological activity: Planetary evolution is also influenced by geological processes such as volcanism, tectonics, and erosion. These processes can shape the planet's surface, create mountain ranges, and carve out valleys and basins.
4. Atmospheric evolution: The evolution of a planet's atmosphere is closely tied to its geological activity and the presence of volatiles (gases that easily vaporize). Over time, the composition of a planet's atmosphere can change due to processes such as outgassing from the interior, chemical reactions, and interactions with the solar wind.
5. Climate evolution: The climate of a planet can also evolve over time due to changes in its orbit, axial tilt, and atmospheric composition. These factors can influence the amount of sunlight a planet receives and the greenhouse effect, which can lead to global warming or cooling.
6. Impact events: Collisions with other celestial bodies, such as asteroids and comets, can significantly impact a planet's evolution by causing large-scale changes to its surface and atmosphere.
7. Life: On planets where life emerges, biological processes can also play a role in shaping the planet's environment and influencing its evolution. For example, photosynthetic organisms can produce oxygen, which can alter the composition of a planet's atmosphere.

Understanding the various factors that contribute to a planet's evolution is crucial for understanding the formation and development of planetary systems and searching for potentially habitable exoplanets.

Radioisotopes, also known as radioactive isotopes or radionuclides, are variants of chemical elements that have unstable nuclei and emit radiation in the form of alpha particles, beta particles, gamma rays, or conversion electrons. These isotopes are formed when an element's nucleus undergoes natural or artificial radioactive decay.

Radioisotopes can be produced through various processes, including nuclear fission, nuclear fusion, and particle bombardment in a cyclotron or other types of particle accelerators. They have a wide range of applications in medicine, industry, agriculture, research, and energy production. In the medical field, radioisotopes are used for diagnostic imaging, radiation therapy, and in the labeling of molecules for research purposes.

It is important to note that handling and using radioisotopes requires proper training, safety measures, and regulatory compliance due to their ionizing radiation properties, which can pose potential health risks if not handled correctly.

I'm sorry for any confusion, but "Hydrogen" is not a medical term. It is a chemical element with the symbol H and atomic number 1. It is the lightest and most abundant chemical element in the universe, making up about 75% of its elemental mass.

In a medical context, hydrogen can be discussed in terms of molecular hydrogen (H2) which has been studied for potential therapeutic benefits. Some research explores its use as an antioxidant and anti-inflammatory agent, but more studies are needed to confirm these effects and understand the mechanisms behind them.

Carbon radioisotopes are radioactive isotopes of carbon, which is an naturally occurring chemical element with the atomic number 6. The most common and stable isotope of carbon is carbon-12 (^12C), but there are also several radioactive isotopes, including carbon-11 (^11C), carbon-14 (^14C), and carbon-13 (^13C). These radioisotopes have different numbers of neutrons in their nuclei, which makes them unstable and causes them to emit radiation.

Carbon-11 has a half-life of about 20 minutes and is used in medical imaging techniques such as positron emission tomography (PET) scans. It is produced by bombarding nitrogen-14 with protons in a cyclotron.

Carbon-14, also known as radiocarbon, has a half-life of about 5730 years and is used in archaeology and geology to date organic materials. It is produced naturally in the atmosphere by cosmic rays.

Carbon-13 is stable and has a natural abundance of about 1.1% in carbon. It is not radioactive, but it can be used as a tracer in medical research and in the study of metabolic processes.

Liquid chromatography (LC) is a type of chromatography technique used to separate, identify, and quantify the components in a mixture. In this method, the sample mixture is dissolved in a liquid solvent (the mobile phase) and then passed through a stationary phase, which can be a solid or a liquid that is held in place by a solid support.

The components of the mixture interact differently with the stationary phase and the mobile phase, causing them to separate as they move through the system. The separated components are then detected and measured using various detection techniques, such as ultraviolet (UV) absorbance or mass spectrometry.

Liquid chromatography is widely used in many areas of science and medicine, including drug development, environmental analysis, food safety testing, and clinical diagnostics. It can be used to separate and analyze a wide range of compounds, from small molecules like drugs and metabolites to large biomolecules like proteins and nucleic acids.

Zinc radioisotopes are unstable isotopes or variants of the element zinc that undergo radioactive decay, emitting radiation in the process. These isotopes have a different number of neutrons than the stable isotope of zinc (zinc-64), which contributes to their instability and tendency to decay.

Examples of zinc radioisotopes include zinc-65, zinc-70, and zinc-72. These isotopes are often used in medical research and diagnostic procedures due to their ability to emit gamma rays or positrons, which can be detected using specialized equipment.

Zinc radioisotopes may be used as tracers to study the metabolism and distribution of zinc in the body, or as therapeutic agents to deliver targeted radiation therapy to cancer cells. However, it is important to note that the use of radioisotopes carries potential risks, including exposure to ionizing radiation and the potential for damage to healthy tissues.

I'm sorry for any confusion, but "geologic sediments" is not a term used in medical definitions. Geological sediments are deposits of material that accumulate over time, usually in layers, as a result of natural geological processes such as weathering, erosion, and deposition. These sediments can eventually become rock formations and provide important clues about the Earth's history, including information about past climates, environments, and life on Earth.

I'm sorry for any confusion, but "meteoroids" is not a term used in medical definitions. It is a term from the field of astronomy. Meteoroids are small particles or bits of rock that are traveling in space. When they enter the Earth's atmosphere, they can become meteors (also known as "shooting stars") and can sometimes make it to the ground as meteorites.

In the context of medical definitions, 'carbon' is not typically used as a standalone term. Carbon is an element with the symbol C and atomic number 6, which is naturally abundant in the human body and the environment. It is a crucial component of all living organisms, forming the basis of organic compounds, such as proteins, carbohydrates, lipids, and nucleic acids (DNA and RNA).

Carbon forms strong covalent bonds with various elements, allowing for the creation of complex molecules that are essential to life. In this sense, carbon is a fundamental building block of life on Earth. However, it does not have a specific medical definition as an isolated term.

Radiometric dating is a method used to determine the age of objects, including rocks and other fossilized materials, based on the decay rates of radioactive isotopes. This technique relies on the fact that certain elements, such as carbon-14, potassium-40, and uranium-238, are unstable and gradually decay into different elements over time.

By measuring the ratio of the remaining radioactive isotope to the stable end product, scientists can calculate the age of a sample using the following formula:

age = (ln(Nf/N0)) / λ

where Nf is the number of atoms of the decayed isotope, N0 is the initial number of atoms of the radioactive isotope, and λ is the decay constant.

Radiometric dating has been used to date objects ranging from a few thousand years old to billions of years old, making it an essential tool for archaeologists, geologists, and other scientists who study the history of our planet.

Tandem mass spectrometry (MS/MS) is a technique used to identify and quantify specific molecules, such as proteins or metabolites, within complex mixtures. This method uses two or more sequential mass analyzers to first separate ions based on their mass-to-charge ratio and then further fragment the selected ions into smaller pieces for additional analysis. The fragmentation patterns generated in MS/MS experiments can be used to determine the structure and identity of the original molecule, making it a powerful tool in various fields such as proteomics, metabolomics, and forensic science.

I'm sorry for any confusion, but "geological phenomena" is not a term typically used in medical definitions. Geological phenomena refer to natural processes and features related to the earth's physical structure, composition, and the various changes it undergoes over time. This could include things like volcanic eruptions, earthquakes, rock formations, or the formation of fossil fuels. If you have a term that you would like me to provide a medical definition for, I'd be happy to help!

I'm sorry for any confusion, but the term "food chain" is not typically used in a medical context. It is a concept from ecology that describes the sequence of organisms through which food and energy pass as one organism eats another.

However, if you're referring to "food web" or "dietary intake," these terms might be more applicable in a medical context. For instance, dietary intake refers to what and how much a person consumes, which can have significant implications for their health. A food web, on the other hand, is a more complex network of relationships between different species that consume and are consumed by others, which can help researchers understand the impacts of changes in one species' population or behavior on others within an ecosystem.

If you meant to ask about something else, please provide more context or clarify your question, and I will do my best to provide a helpful answer!

Tritium is not a medical term, but it is a term used in the field of nuclear physics and chemistry. Tritium (symbol: T or 3H) is a radioactive isotope of hydrogen with two neutrons and one proton in its nucleus. It is also known as heavy hydrogen or superheavy hydrogen.

Tritium has a half-life of about 12.3 years, which means that it decays by emitting a low-energy beta particle (an electron) to become helium-3. Due to its radioactive nature and relatively short half-life, tritium is used in various applications, including nuclear weapons, fusion reactors, luminous paints, and medical research.

In the context of medicine, tritium may be used as a radioactive tracer in some scientific studies or medical research, but it is not a term commonly used to describe a medical condition or treatment.

Proteomics is the large-scale study and analysis of proteins, including their structures, functions, interactions, modifications, and abundance, in a given cell, tissue, or organism. It involves the identification and quantification of all expressed proteins in a biological sample, as well as the characterization of post-translational modifications, protein-protein interactions, and functional pathways. Proteomics can provide valuable insights into various biological processes, diseases, and drug responses, and has applications in basic research, biomedicine, and clinical diagnostics. The field combines various techniques from molecular biology, chemistry, physics, and bioinformatics to study proteins at a systems level.

Intestinal absorption refers to the process by which the small intestine absorbs water, nutrients, and electrolytes from food into the bloodstream. This is a critical part of the digestive process, allowing the body to utilize the nutrients it needs and eliminate waste products. The inner wall of the small intestine contains tiny finger-like projections called villi, which increase the surface area for absorption. Nutrients are absorbed into the bloodstream through the walls of the capillaries in these villi, and then transported to other parts of the body for use or storage.

Oxidation-Reduction (redox) reactions are a type of chemical reaction involving a transfer of electrons between two species. The substance that loses electrons in the reaction is oxidized, and the substance that gains electrons is reduced. Oxidation and reduction always occur together in a redox reaction, hence the term "oxidation-reduction."

In biological systems, redox reactions play a crucial role in many cellular processes, including energy production, metabolism, and signaling. The transfer of electrons in these reactions is often facilitated by specialized molecules called electron carriers, such as nicotinamide adenine dinucleotide (NAD+/NADH) and flavin adenine dinucleotide (FAD/FADH2).

The oxidation state of an element in a compound is a measure of the number of electrons that have been gained or lost relative to its neutral state. In redox reactions, the oxidation state of one or more elements changes as they gain or lose electrons. The substance that is oxidized has a higher oxidation state, while the substance that is reduced has a lower oxidation state.

Overall, oxidation-reduction reactions are fundamental to the functioning of living organisms and are involved in many important biological processes.

In medical terms, the term "atmosphere" is not typically used as a standalone definition or diagnosis. However, in some contexts, it may refer to the physical environment or surroundings in which medical care is provided. For example, some hospitals and healthcare facilities may have different atmospheres depending on their specialties, design, or overall ambiance.

Additionally, "atmosphere" may also be used more broadly to describe the social or emotional climate of a particular healthcare setting. For instance, a healthcare provider might describe a patient's home atmosphere as warm and welcoming, or a hospital ward's atmosphere as tense or chaotic.

It is important to note that "atmosphere" is not a medical term with a specific definition, so its meaning may vary depending on the context in which it is used.

Catalysis is the process of increasing the rate of a chemical reaction by adding a substance known as a catalyst, which remains unchanged at the end of the reaction. A catalyst lowers the activation energy required for the reaction to occur, thereby allowing the reaction to proceed more quickly and efficiently. This can be particularly important in biological systems, where enzymes act as catalysts to speed up metabolic reactions that are essential for life.

I'm sorry for any confusion, but "Volcanic Eruptions" are not a medical term or concept. Volcanic eruptions refer to the release of molten rock, ash, and gases from a volcano's opening, or vent, onto the Earth's surface. This is a geological event that occurs due to the movement of tectonic plates and the build-up of pressure within the Earth's crust.

If you have any medical questions or terms you would like me to define, please feel free to ask!

I'm sorry for any confusion, but "geology" is not a medical term. It is a scientific discipline that deals with the Earth's physical structure and substance, its history, and the processes that act on it. If you have any questions about medical terminology or concepts, I would be happy to help!

Chemical fractionation is a process used in analytical chemistry to separate and isolate individual components or fractions from a mixture based on their chemical properties. This technique typically involves the use of various chemical reactions, such as precipitation, extraction, or chromatography, to selectively interact with specific components in the mixture and purify them.

In the context of medical research or clinical analysis, chemical fractionation may be used to isolate and identify individual compounds in a complex biological sample, such as blood, urine, or tissue. For example, fractionating a urine sample might involve separating out various metabolites, proteins, or other molecules based on their solubility, charge, or other chemical properties, allowing researchers to study the individual components and their roles in health and disease.

It's worth noting that while chemical fractionation can be a powerful tool for analyzing complex mixtures, it can also be time-consuming and technically challenging, requiring specialized equipment and expertise to perform accurately and reliably.

A chemical model is a simplified representation or description of a chemical system, based on the laws of chemistry and physics. It is used to explain and predict the behavior of chemicals and chemical reactions. Chemical models can take many forms, including mathematical equations, diagrams, and computer simulations. They are often used in research, education, and industry to understand complex chemical processes and develop new products and technologies.

For example, a chemical model might be used to describe the way that atoms and molecules interact in a particular reaction, or to predict the properties of a new material. Chemical models can also be used to study the behavior of chemicals at the molecular level, such as how they bind to each other or how they are affected by changes in temperature or pressure.

It is important to note that chemical models are simplifications of reality and may not always accurately represent every aspect of a chemical system. They should be used with caution and validated against experimental data whenever possible.

I'm not a medical professional, but the term "History, Ancient" is not a medical term per se. However, in a broader context, it could refer to the study of ancient medical practices, theories, and beliefs that existed in civilizations prior to the Middle Ages or Classical Antiquity. This might include the examination of ancient texts, artifacts, and archaeological evidence to understand how illnesses were treated and viewed in these historical periods. It forms an essential part of the evolution of medical knowledge and practices over time.

Nitrogen is not typically referred to as a medical term, but it is an element that is crucial to medicine and human life.

In a medical context, nitrogen is often mentioned in relation to gas analysis, respiratory therapy, or medical gases. Nitrogen (N) is a colorless, odorless, and nonreactive gas that makes up about 78% of the Earth's atmosphere. It is an essential element for various biological processes, such as the growth and maintenance of organisms, because it is a key component of amino acids, nucleic acids, and other organic compounds.

In some medical applications, nitrogen is used to displace oxygen in a mixture to create a controlled environment with reduced oxygen levels (hypoxic conditions) for therapeutic purposes, such as in certain types of hyperbaric chambers. Additionally, nitrogen gas is sometimes used in cryotherapy, where extremely low temperatures are applied to tissues to reduce pain, swelling, and inflammation.

However, it's important to note that breathing pure nitrogen can be dangerous, as it can lead to unconsciousness and even death due to lack of oxygen (asphyxiation) within minutes.

Radioactive tracers are radioisotopes or radiolabeled compounds that are introduced into a biological system, such as the human body, in very small amounts to allow tracking or monitoring of specific physiological processes or locations. The radiation emitted by the tracer can be detected and measured, providing information about the distribution, metabolism, or binding of the compound within the body. This technique is widely used in medical imaging and research for diagnostic and therapeutic purposes. Examples of radioactive tracers include technetium-99m for bone scans, fluorine-18 for positron emission tomography (PET) scans, and iodine-131 for thyroid studies.

In the field of medicine and particularly in forensic pathology, mummies are human or animal bodies that have been preserved naturally or intentionally after death, through processes such as desiccation (drying), freezing, or exposure to chemicals like salt or smoke. The study of mummies, known as mummy science or mummy studies, can provide valuable insights into various aspects including the biological characteristics, health conditions, dietary habits, and cultural practices of past civilizations.

Medical definitions of water generally describe it as a colorless, odorless, tasteless liquid that is essential for all forms of life. It is a universal solvent, making it an excellent medium for transporting nutrients and waste products within the body. Water constitutes about 50-70% of an individual's body weight, depending on factors such as age, sex, and muscle mass.

In medical terms, water has several important functions in the human body:

1. Regulation of body temperature through perspiration and respiration.
2. Acting as a lubricant for joints and tissues.
3. Facilitating digestion by helping to break down food particles.
4. Transporting nutrients, oxygen, and waste products throughout the body.
5. Helping to maintain healthy skin and mucous membranes.
6. Assisting in the regulation of various bodily functions, such as blood pressure and heart rate.

Dehydration can occur when an individual does not consume enough water or loses too much fluid due to illness, exercise, or other factors. This can lead to a variety of symptoms, including dry mouth, fatigue, dizziness, and confusion. Severe dehydration can be life-threatening if left untreated.

Carbon-carbon lyases are a class of enzymes that catalyze the breaking of carbon-carbon bonds in a substrate, resulting in the formation of two molecules with a double bond between them. This reaction is typically accompanied by the release or addition of a cofactor such as water or a coenzyme.

These enzymes play important roles in various metabolic pathways, including the breakdown of carbohydrates, lipids, and amino acids. They are also involved in the biosynthesis of secondary metabolites, such as terpenoids and alkaloids.

Carbon-carbon lyases are classified under EC number 4.1.2. in the Enzyme Commission (EC) system. This classification includes a wide range of enzymes with different substrate specificities and reaction mechanisms. Examples of carbon-carbon lyases include decarboxylases, aldolases, and dehydratases.

It's worth noting that the term "lyase" refers to any enzyme that catalyzes the removal of a group of atoms from a molecule, leaving a double bond or a cycle, and it does not necessarily imply the formation of carbon-carbon bonds.

Paleontology is not a medical field, but rather it is a branch of earth sciences and biology that deals with the study of prehistoric life forms through the examination of plant and animal fossils, including those of extinct organisms. It involves various disciplines such as stratigraphy, geochronology, and systematics to understand the evolutionary history of life on Earth.

However, I understand that you are looking for information related to a non-medical topic, so here is some additional context:

Paleontology can be divided into several subdisciplines, including vertebrate paleontology (the study of fossilized animals with backbones), invertebrate paleontology (the study of fossilized animals without backbones), paleobotany (the study of fossil plants), micropaleontology (the study of microscopic fossils), and taphonomy (the study of the processes that occur after an organism's death, leading to its preservation as a fossil).

Paleontologists use various techniques to study fossils, including comparative anatomy, histology (the study of tissue structure), and geochemistry. They also rely on other scientific fields such as genetics, physics, and chemistry to help them interpret the data they collect from fossils.

Through their research, paleontologists can learn about the morphology, behavior, ecology, and evolutionary relationships of extinct organisms, providing valuable insights into the history of life on Earth.

Methane is not a medical term, but it is a chemical compound that is often mentioned in the context of medicine and health. Medically, methane is significant because it is one of the gases produced by anaerobic microorganisms during the breakdown of organic matter in the gut, leading to conditions such as bloating, cramping, and diarrhea. Excessive production of methane can also be a symptom of certain digestive disorders like irritable bowel syndrome (IBS) and small intestinal bacterial overgrowth (SIBO).

In broader terms, methane is a colorless, odorless gas that is the primary component of natural gas. It is produced naturally by the decomposition of organic matter in anaerobic conditions, such as in landfills, wetlands, and the digestive tracts of animals like cows and humans. Methane is also a potent greenhouse gas with a global warming potential 25 times greater than carbon dioxide over a 100-year time frame.

I'm sorry for any confusion, but "Oceans and Seas" are not medical terms. Generally speaking, an ocean is a large body of saltwater that covers a majority of the Earth's surface, and a sea is a smaller body of saltwater that may be partially enclosed by land. However, if you have any questions related to marine biology or environmental science, I would be happy to try and help answer those for you!

In medicine, "absorption" refers to the process by which substances, including nutrients, medications, or toxins, are taken up and assimilated into the body's tissues or bloodstream after they have been introduced into the body via various routes (such as oral, intravenous, or transdermal).

The absorption of a substance depends on several factors, including its chemical properties, the route of administration, and the presence of other substances that may affect its uptake. For example, some medications may be better absorbed when taken with food, while others may require an empty stomach for optimal absorption.

Once a substance is absorbed into the bloodstream, it can then be distributed to various tissues throughout the body, where it may exert its effects or be metabolized and eliminated by the body's detoxification systems. Understanding the process of absorption is crucial in developing effective medical treatments and determining appropriate dosages for medications.

Carbon dioxide (CO2) is a colorless, odorless gas that is naturally present in the Earth's atmosphere. It is a normal byproduct of cellular respiration in humans, animals, and plants, and is also produced through the combustion of fossil fuels such as coal, oil, and natural gas.

In medical terms, carbon dioxide is often used as a respiratory stimulant and to maintain the pH balance of blood. It is also used during certain medical procedures, such as laparoscopic surgery, to insufflate (inflate) the abdominal cavity and create a working space for the surgeon.

Elevated levels of carbon dioxide in the body can lead to respiratory acidosis, a condition characterized by an increased concentration of carbon dioxide in the blood and a decrease in pH. This can occur in conditions such as chronic obstructive pulmonary disease (COPD), asthma, or other lung diseases that impair breathing and gas exchange. Symptoms of respiratory acidosis may include shortness of breath, confusion, headache, and in severe cases, coma or death.

An "ecosystem" is not a term that has a specific medical definition, as it is a concept that is more commonly used in the fields of ecology and environmental science. However, I can provide you with the general ecological definition of an ecosystem:

An ecosystem is a community of living organisms interacting with each other and their non-living environment, including both biotic factors (plants, animals, microorganisms) and abiotic factors (climate, soil, water, and air). These interactions create a complex network of relationships that form the foundation of ecological processes, such as energy flow, nutrient cycling, and population dynamics.

While there is no direct medical definition for an ecosystem, understanding the principles of ecosystems can have important implications for human health. For example, healthy ecosystems can provide clean air and water, regulate climate, support food production, and offer opportunities for recreation and relaxation, all of which contribute to overall well-being. Conversely, degraded ecosystems can lead to increased exposure to environmental hazards, reduced access to natural resources, and heightened risks of infectious diseases. Therefore, maintaining the health and integrity of ecosystems is crucial for promoting human health and preventing disease.

In medical terms, "fossils" do not have a specific or direct relevance to the field. However, in a broader scientific context, fossils are the remains or impressions of prehistoric organisms preserved in petrified form or as a mold or cast in rock. They offer valuable evidence about the Earth's history and the life forms that existed on it millions of years ago.

Paleopathology is a subfield of paleontology that deals with the study of diseases in fossils, which can provide insights into the evolution of diseases and human health over time.

Animal migration is a seasonal movement of animals from one place to another, typically over long distances, to find food, reproduce, or escape harsh conditions. This phenomenon is observed in various species, including birds, mammals, fish, and insects. The routes and destinations of these migrations are often genetically programmed and can be quite complex. Animal migration has important ecological consequences and is influenced by factors such as climate change, habitat loss, and human activities.

Hydrogen-ion concentration, also known as pH, is a measure of the acidity or basicity of a solution. It is defined as the negative logarithm (to the base 10) of the hydrogen ion activity in a solution. The standard unit of measurement is the pH unit. A pH of 7 is neutral, less than 7 is acidic, and greater than 7 is basic.

In medical terms, hydrogen-ion concentration is important for maintaining homeostasis within the body. For example, in the stomach, a high hydrogen-ion concentration (low pH) is necessary for the digestion of food. However, in other parts of the body such as blood, a high hydrogen-ion concentration can be harmful and lead to acidosis. Conversely, a low hydrogen-ion concentration (high pH) in the blood can lead to alkalosis. Both acidosis and alkalosis can have serious consequences on various organ systems if not corrected.

The proteome is the entire set of proteins produced or present in an organism, system, organ, or cell at a certain time under specific conditions. It is a dynamic collection of protein species that changes over time, responding to various internal and external stimuli such as disease, stress, or environmental factors. The study of the proteome, known as proteomics, involves the identification and quantification of these protein components and their post-translational modifications, providing valuable insights into biological processes, functional pathways, and disease mechanisms.

Amino acids are organic compounds that serve as the building blocks of proteins. They consist of a central carbon atom, also known as the alpha carbon, which is bonded to an amino group (-NH2), a carboxyl group (-COOH), a hydrogen atom (H), and a variable side chain (R group). The R group can be composed of various combinations of atoms such as hydrogen, oxygen, sulfur, nitrogen, and carbon, which determine the unique properties of each amino acid.

There are 20 standard amino acids that are encoded by the genetic code and incorporated into proteins during translation. These include:

1. Alanine (Ala)
2. Arginine (Arg)
3. Asparagine (Asn)
4. Aspartic acid (Asp)
5. Cysteine (Cys)
6. Glutamine (Gln)
7. Glutamic acid (Glu)
8. Glycine (Gly)
9. Histidine (His)
10. Isoleucine (Ile)
11. Leucine (Leu)
12. Lysine (Lys)
13. Methionine (Met)
14. Phenylalanine (Phe)
15. Proline (Pro)
16. Serine (Ser)
17. Threonine (Thr)
18. Tryptophan (Trp)
19. Tyrosine (Tyr)
20. Valine (Val)

Additionally, there are several non-standard or modified amino acids that can be incorporated into proteins through post-translational modifications, such as hydroxylation, methylation, and phosphorylation. These modifications expand the functional diversity of proteins and play crucial roles in various cellular processes.

Amino acids are essential for numerous biological functions, including protein synthesis, enzyme catalysis, neurotransmitter production, energy metabolism, and immune response regulation. Some amino acids can be synthesized by the human body (non-essential), while others must be obtained through dietary sources (essential).

Seawater is not a medical term, but it is a type of water that covers more than 70% of the Earth's surface. Medically, seawater can be relevant in certain contexts, such as in discussions of marine biology, environmental health, or water safety. Seawater has a high salt content, with an average salinity of around 3.5%, which is much higher than that of freshwater. This makes it unsuitable for drinking or irrigation without desalination.

Exposure to seawater can also have medical implications, such as in cases of immersion injuries, marine envenomations, or waterborne illnesses. However, there is no single medical definition of seawater.

I believe you may have made a typo in your question. "Archaeology" is the scientific study of past human cultures and societies through the recovery, examination, and analysis of material remains such as artifacts, buildings, biofacts (e.g., bones, shells), and cultural landscapes. It is not typically associated with medical definitions. If you intended to ask for a different term related to medicine or healthcare, please let me know so I can provide the correct information.

For more information about archaeology, you may be interested in visiting the World Archaeological Congress () or the Society for American Archaeology () websites to learn more about this fascinating field of study.

I'm sorry for any confusion, but "Solar System" is not a medical term. It refers to the astronomical system that includes our star, the Sun, and the objects that orbit it, such as planets, dwarf planets, asteroids, comets, and meteoroids. The Solar System is located in the Milky Way galaxy. If you have any medical terms or concepts you would like me to define or explain, I'd be happy to help!

In the context of medicine, particularly in relation to cancer treatment, protons refer to positively charged subatomic particles found in the nucleus of an atom. Proton therapy, a type of radiation therapy, uses a beam of protons to target and destroy cancer cells with high precision, minimizing damage to surrounding healthy tissue. The concentrated dose of radiation is delivered directly to the tumor site, reducing side effects and improving quality of life during treatment.

Magnetic Resonance Spectroscopy (MRS) is a non-invasive diagnostic technique that provides information about the biochemical composition of tissues, including their metabolic state. It is often used in conjunction with Magnetic Resonance Imaging (MRI) to analyze various metabolites within body tissues, such as the brain, heart, liver, and muscles.

During MRS, a strong magnetic field, radio waves, and a computer are used to produce detailed images and data about the concentration of specific metabolites in the targeted tissue or organ. This technique can help detect abnormalities related to energy metabolism, neurotransmitter levels, pH balance, and other biochemical processes, which can be useful for diagnosing and monitoring various medical conditions, including cancer, neurological disorders, and metabolic diseases.

There are different types of MRS, such as Proton (^1^H) MRS, Phosphorus-31 (^31^P) MRS, and Carbon-13 (^13^C) MRS, each focusing on specific elements or metabolites within the body. The choice of MRS technique depends on the clinical question being addressed and the type of information needed for diagnosis or monitoring purposes.

A diet, in medical terms, refers to the planned and regular consumption of food and drinks. It is a balanced selection of nutrient-rich foods that an individual eats on a daily or periodic basis to meet their energy needs and maintain good health. A well-balanced diet typically includes a variety of fruits, vegetables, whole grains, lean proteins, and low-fat dairy products.

A diet may also be prescribed for therapeutic purposes, such as in the management of certain medical conditions like diabetes, hypertension, or obesity. In these cases, a healthcare professional may recommend specific restrictions or modifications to an individual's regular diet to help manage their condition and improve their overall health.

It is important to note that a healthy and balanced diet should be tailored to an individual's age, gender, body size, activity level, and any underlying medical conditions. Consulting with a healthcare professional, such as a registered dietitian or nutritionist, can help ensure that an individual's dietary needs are being met in a safe and effective way.

Mass spectrometry with electrospray ionization (ESI-MS) is an analytical technique used to identify and quantify chemical species in a sample based on the mass-to-charge ratio of charged particles. In ESI-MS, analytes are ionized through the use of an electrospray, where a liquid sample is introduced through a metal capillary needle at high voltage, creating an aerosol of charged droplets. As the solvent evaporates, the analyte molecules become charged and can be directed into a mass spectrometer for analysis.

ESI-MS is particularly useful for the analysis of large biomolecules such as proteins, peptides, and nucleic acids, due to its ability to gently ionize these species without fragmentation. The technique provides information about the molecular weight and charge state of the analytes, which can be used to infer their identity and structure. Additionally, ESI-MS can be interfaced with separation techniques such as liquid chromatography (LC) for further purification and characterization of complex samples.

Biological availability is a term used in pharmacology and toxicology that refers to the degree and rate at which a drug or other substance is absorbed into the bloodstream and becomes available at the site of action in the body. It is a measure of the amount of the substance that reaches the systemic circulation unchanged, after administration by any route (such as oral, intravenous, etc.).

The biological availability (F) of a drug can be calculated using the area under the curve (AUC) of the plasma concentration-time profile after extravascular and intravenous dosing, according to the following formula:

F = (AUCex/AUCiv) x (Doseiv/Doseex)

where AUCex is the AUC after extravascular dosing, AUCiv is the AUC after intravenous dosing, Doseiv is the intravenous dose, and Doseex is the extravascular dose.

Biological availability is an important consideration in drug development and therapy, as it can affect the drug's efficacy, safety, and dosage regimen. Drugs with low biological availability may require higher doses to achieve the desired therapeutic effect, while drugs with high biological availability may have a more rapid onset of action and require lower doses to avoid toxicity.

Technetium is not a medical term itself, but it is a chemical element with the symbol Tc and atomic number 43. However, in the field of nuclear medicine, which is a branch of medicine that uses small amounts of radioactive material to diagnose or treat diseases, Technetium-99m (a radioisotope of technetium) is commonly used for various diagnostic procedures.

Technetium-99m is a metastable nuclear isomer of technetium-99, and it emits gamma rays that can be detected outside the body to create images of internal organs or tissues. It has a short half-life of about 6 hours, which makes it ideal for diagnostic imaging since it decays quickly and reduces the patient's exposure to radiation.

Technetium-99m is used in a variety of medical procedures, such as bone scans, lung scans, heart scans, liver-spleen scans, brain scans, and kidney scans, among others. It can be attached to different pharmaceuticals or molecules that target specific organs or tissues, allowing healthcare professionals to assess their function or identify any abnormalities.

Radionuclide imaging, also known as nuclear medicine, is a medical imaging technique that uses small amounts of radioactive material, called radionuclides or radiopharmaceuticals, to diagnose and treat various diseases and conditions. The radionuclides are introduced into the body through injection, inhalation, or ingestion and accumulate in specific organs or tissues. A special camera then detects the gamma rays emitted by these radionuclides and converts them into images that provide information about the structure and function of the organ or tissue being studied.

Radionuclide imaging can be used to evaluate a wide range of medical conditions, including heart disease, cancer, neurological disorders, gastrointestinal disorders, and bone diseases. The technique is non-invasive and generally safe, with minimal exposure to radiation. However, it should only be performed by qualified healthcare professionals in accordance with established guidelines and regulations.

Ammonium compounds are chemical substances that contain the ammonium ion (NH4+). The ammonium ion is formed when ammonia (NH3) reacts with a hydrogen ion (H+) to form a bond. Ammonium compounds can be found in a variety of forms, including salts, acids, and bases.

In medicine, ammonium compounds may be used for various purposes. For example, ammonium chloride is sometimes used as a expectorant to help loosen mucus in the airways, while ammonium bicarbonate is used as a systemic alkalizer to treat metabolic acidosis.

However, it's important to note that some ammonium compounds can be toxic in high concentrations. For instance, exposure to high levels of ammonia gas (NH3) can cause respiratory irritation and damage to the lungs. Similarly, ingesting large amounts of ammonium chloride can lead to stomach upset, vomiting, and potentially life-threatening electrolyte imbalances.

Therefore, it's essential to use ammonium compounds only under the guidance of a healthcare professional and to follow recommended dosages carefully to avoid adverse effects.

Deuterium exchange measurement is a technique used in physical chemistry and biochemistry to study the structure, dynamics, and interactions of proteins, peptides, and other biological macromolecules. This method involves the exchange of deuterium (a heavy isotope of hydrogen) for hydrogen atoms in the molecule of interest.

The process typically begins with the preparation of a sample containing the macromolecule, which is then exposed to an environment with a high concentration of deuterated solvent, such as heavy water (D2O). Over time, some or all of the exchangeable hydrogen atoms in the molecule will be replaced by deuterium atoms through a series of chemical reactions.

The rate and extent of this deuterium exchange can provide valuable information about various aspects of the macromolecule's structure and behavior, including:

1. Solvent accessibility: Regions of the molecule that are exposed to solvent will typically undergo faster deuterium exchange than those that are buried within the protein's core or shielded by other structures. This allows researchers to identify which parts of the molecule are accessible to the solvent and infer information about its overall shape and conformation.
2. Dynamics: The rate of deuterium exchange can also be used to study the flexibility and dynamics of different regions of the macromolecule. Flexible or disordered regions will typically exhibit faster exchange rates than more rigid or structured ones, providing insights into the molecule's internal motions and conformational changes.
3. Interactions: Deuterium exchange measurements can also be used to study how the macromolecule interacts with other molecules, such as ligands, drugs, or other proteins. By comparing the deuterium exchange patterns in the presence and absence of these interaction partners, researchers can identify which regions of the molecule are involved in binding and learn more about the nature of these interactions.

There are several experimental methods for measuring deuterium exchange, including nuclear magnetic resonance (NMR) spectroscopy, mass spectrometry (MS), and infrared spectroscopy (IR). Each method has its advantages and limitations, but all provide valuable information that can help researchers better understand the structure, dynamics, and function of biological macromolecules.

Reference standards in a medical context refer to the established and widely accepted norms or benchmarks used to compare, evaluate, or measure the performance, accuracy, or effectiveness of diagnostic tests, treatments, or procedures. These standards are often based on extensive research, clinical trials, and expert consensus, and they help ensure that healthcare practices meet certain quality and safety thresholds.

For example, in laboratory medicine, reference standards may consist of well-characterized samples with known concentrations of analytes (such as chemicals or biological markers) that are used to calibrate instruments and validate testing methods. In clinical practice, reference standards may take the form of evidence-based guidelines or best practices that define appropriate care for specific conditions or patient populations.

By adhering to these reference standards, healthcare professionals can help minimize variability in test results, reduce errors, improve diagnostic accuracy, and ensure that patients receive consistent, high-quality care.

Forensic sciences is the application of scientific methods and techniques to investigations by law enforcement agencies or courts of law. It involves the use of various scientific disciplines, such as chemistry, biology, physics, and psychology, to assist in the examination of physical evidence, interpretation of crime scene data, and evaluation of behavioral patterns. The goal is to provide objective information that can help establish the facts of a case and contribute to the administration of justice.

Forensic science encompasses several sub-disciplines, including forensic biology (DNA analysis, serology, and forensic anthropology), forensic chemistry (drug analysis, toxicology, and digital forensics), forensic physics (firearms and toolmark identification, ballistics, and digital forensics), and forensic psychology (criminal profiling, eyewitness testimony, and legal psychology).

The ultimate objective of forensic sciences is to provide unbiased, scientifically validated information that can aid in the investigation and prosecution of criminal cases, as well as protect the rights of defendants and promote the integrity of the legal system.

Solvents, in a medical context, are substances that are capable of dissolving or dispersing other materials, often used in the preparation of medications and solutions. They are commonly organic chemicals that can liquefy various substances, making it possible to administer them in different forms, such as oral solutions, topical creams, or injectable drugs.

However, it is essential to recognize that solvents may pose health risks if mishandled or misused, particularly when they contain volatile organic compounds (VOCs). Prolonged exposure to these VOCs can lead to adverse health effects, including respiratory issues, neurological damage, and even cancer. Therefore, it is crucial to handle solvents with care and follow safety guidelines to minimize potential health hazards.

Biological models, also known as physiological models or organismal models, are simplified representations of biological systems, processes, or mechanisms that are used to understand and explain the underlying principles and relationships. These models can be theoretical (conceptual or mathematical) or physical (such as anatomical models, cell cultures, or animal models). They are widely used in biomedical research to study various phenomena, including disease pathophysiology, drug action, and therapeutic interventions.

Examples of biological models include:

1. Mathematical models: These use mathematical equations and formulas to describe complex biological systems or processes, such as population dynamics, metabolic pathways, or gene regulation networks. They can help predict the behavior of these systems under different conditions and test hypotheses about their underlying mechanisms.
2. Cell cultures: These are collections of cells grown in a controlled environment, typically in a laboratory dish or flask. They can be used to study cellular processes, such as signal transduction, gene expression, or metabolism, and to test the effects of drugs or other treatments on these processes.
3. Animal models: These are living organisms, usually vertebrates like mice, rats, or non-human primates, that are used to study various aspects of human biology and disease. They can provide valuable insights into the pathophysiology of diseases, the mechanisms of drug action, and the safety and efficacy of new therapies.
4. Anatomical models: These are physical representations of biological structures or systems, such as plastic models of organs or tissues, that can be used for educational purposes or to plan surgical procedures. They can also serve as a basis for developing more sophisticated models, such as computer simulations or 3D-printed replicas.

Overall, biological models play a crucial role in advancing our understanding of biology and medicine, helping to identify new targets for therapeutic intervention, develop novel drugs and treatments, and improve human health.

Medically, hair is defined as a threadlike structure that grows from the follicles found in the skin of mammals. It is primarily made up of a protein called keratin and consists of three parts: the medulla (the innermost part or core), the cortex (middle layer containing keratin filaments) and the cuticle (outer layer of overlapping scales).

Hair growth occurs in cycles, with each cycle consisting of a growth phase (anagen), a transitional phase (catagen), and a resting phase (telogen). The length of hair is determined by the duration of the anagen phase.

While hair plays a crucial role in protecting the skin from external factors like UV radiation, temperature changes, and physical damage, it also serves as an essential aspect of human aesthetics and identity.

Feces are the solid or semisolid remains of food that could not be digested or absorbed in the small intestine, along with bacteria and other waste products. After being stored in the colon, feces are eliminated from the body through the rectum and anus during defecation. Feces can vary in color, consistency, and odor depending on a person's diet, health status, and other factors.

In the context of medicine and toxicology, sulfides refer to inorganic or organic compounds containing the sulfide ion (S2-). Sulfides can be found in various forms such as hydrogen sulfide (H2S), metal sulfides, and organic sulfides (also known as thioethers).

Hydrogen sulfide is a toxic gas with a characteristic rotten egg smell. It can cause various adverse health effects, including respiratory irritation, headaches, nausea, and, at high concentrations, loss of consciousness or even death. Metal sulfides, such as those found in some minerals, can also be toxic and may release hazardous sulfur dioxide (SO2) when heated or reacted with acidic substances.

Organic sulfides, on the other hand, are a class of organic compounds containing a sulfur atom bonded to two carbon atoms. They can occur naturally in some plants and animals or be synthesized in laboratories. Some organic sulfides have medicinal uses, while others may pose health risks depending on their concentration and route of exposure.

It is important to note that the term "sulfide" has different meanings in various scientific contexts, so it is essential to consider the specific context when interpreting this term.

I'm sorry for any confusion, but there seems to be a misunderstanding. Mathematics is not a medical term; it is a branch of science dedicated to the study of numbers, shapes, and structures. However, mathematics does have many applications in medicine, such as in modeling disease spread, analyzing medical images, or designing clinical trials. If you have any questions related to mathematics in a medical context, I'd be happy to help clarify those for you!

"Food analysis" is not a medical term per se, but it falls under the broader field of food science and nutrition. Food analysis refers to the laboratory methods and techniques used to determine the composition and quality of food products. This can include testing for nutrients (such as proteins, fats, carbohydrates, vitamins, and minerals), contaminants (like heavy metals, pesticides, or allergens), and other components that may affect the safety, quality, or authenticity of food.

The results of food analysis can be used to ensure compliance with regulatory standards, develop new food products, assess the nutritional value of diets, investigate food-borne illnesses, and monitor trends in food consumption. While not a medical definition, food analysis is an important tool for promoting public health and preventing diet-related diseases.

Zinc is an essential mineral that is vital for the functioning of over 300 enzymes and involved in various biological processes in the human body, including protein synthesis, DNA synthesis, immune function, wound healing, and cell division. It is a component of many proteins and participates in the maintenance of structural integrity and functionality of proteins. Zinc also plays a crucial role in maintaining the sense of taste and smell.

The recommended daily intake of zinc varies depending on age, sex, and life stage. Good dietary sources of zinc include red meat, poultry, seafood, beans, nuts, dairy products, and fortified cereals. Zinc deficiency can lead to various health problems, including impaired immune function, growth retardation, and developmental delays in children. On the other hand, excessive intake of zinc can also have adverse effects on health, such as nausea, vomiting, and impaired immune function.

I'm sorry for any confusion, but "soil" is not a term that has a medical definition. Soil is defined as the top layer of earth in which plants grow, a mixture of organic material, clay, sand, and silt. If you have any questions related to medicine or health, I would be happy to try to help answer them for you.

I'm sorry for any confusion, but "Gold Isotopes" doesn't seem to have a specific medical definition. Isotopes are generally a term used in physics and chemistry. They refer to variants of a particular chemical element which have the same number of protons in their atomic nucleus, but different numbers of neutrons.

Gold, with the atomic number 79, has only one stable isotope, gold-197. The other isotopes are unstable and undergo radioactive decay. These isotopes aren't typically used in a medical context, although some may be used in research or scientific applications.

If you have any questions about a specific medical context or use of isotopes, I'd be happy to try to help further!

Lead radioisotopes refer to specific types of radioactive isotopes (or radionuclides) of the element lead. These isotopes have unstable nuclei and emit radiation as they decay over time, changing into different elements in the process. Examples of lead radioisotopes include lead-210, lead-212, and lead-214. These isotopes are often found in the decay chains of heavier radioactive elements such as uranium and thorium, and they have various applications in fields like nuclear medicine, research, and industrial radiography. However, exposure to high levels of radiation from lead radioisotopes can pose significant health risks, including damage to DNA and increased risk of cancer.

High-performance liquid chromatography (HPLC) is a type of chromatography that separates and analyzes compounds based on their interactions with a stationary phase and a mobile phase under high pressure. The mobile phase, which can be a gas or liquid, carries the sample mixture through a column containing the stationary phase.

In HPLC, the mobile phase is a liquid, and it is pumped through the column at high pressures (up to several hundred atmospheres) to achieve faster separation times and better resolution than other types of liquid chromatography. The stationary phase can be a solid or a liquid supported on a solid, and it interacts differently with each component in the sample mixture, causing them to separate as they travel through the column.

HPLC is widely used in analytical chemistry, pharmaceuticals, biotechnology, and other fields to separate, identify, and quantify compounds present in complex mixtures. It can be used to analyze a wide range of substances, including drugs, hormones, vitamins, pigments, flavors, and pollutants. HPLC is also used in the preparation of pure samples for further study or use.

Molecular structure, in the context of biochemistry and molecular biology, refers to the arrangement and organization of atoms and chemical bonds within a molecule. It describes the three-dimensional layout of the constituent elements, including their spatial relationships, bond lengths, and angles. Understanding molecular structure is crucial for elucidating the functions and reactivities of biological macromolecules such as proteins, nucleic acids, lipids, and carbohydrates. Various experimental techniques, like X-ray crystallography, nuclear magnetic resonance (NMR) spectroscopy, and cryo-electron microscopy (cryo-EM), are employed to determine molecular structures at atomic resolution, providing valuable insights into their biological roles and potential therapeutic targets.

I'm sorry for any confusion, but "Uranium" is not a medical term. It is a chemical element with the symbol "U" and atomic number 92. Uranium is a dense, silvery-gray metal that is hard and brittle at room temperature. It's primarily used as a fuel in nuclear power plants and in the manufacture of weapons.

While uranium does not have direct medical applications, it does pose potential health risks due to its radioactivity. Exposure to high levels of radiation from uranium can lead to acute radiation sickness, anemia, and an increased risk of cancer. However, under normal circumstances, the general public is not exposed to significant amounts of uranium, so it's not a common health concern.

Radioactive water pollutants refer to contaminants in water sources that contain radioactive materials. These materials can include substances such as radium, uranium, and cesium, which emit ionizing radiation. This type of pollution can occur through various means, including the disposal of radioactive waste from nuclear power plants, hospitals, and research facilities; oil and gas drilling operations; and mining activities.

Exposure to radioactive water pollutants can have serious health consequences, as ionizing radiation has been linked to an increased risk of cancer, genetic mutations, and other harmful effects. Therefore, it is essential to regulate and monitor radioactive water pollution to protect public health and the environment.

In the context of medical research, "methods" refers to the specific procedures or techniques used in conducting a study or experiment. This includes details on how data was collected, what measurements were taken, and what statistical analyses were performed. The methods section of a medical paper allows other researchers to replicate the study if they choose to do so. It is considered one of the key components of a well-written research article, as it provides transparency and helps establish the validity of the findings.

I'm sorry for any confusion, but "geography" is not a term that has a medical definition. Geography is a field of study that deals with the location and distribution of physical and cultural features on Earth's surface, as well as how humans interact with and affect those features. It is not a concept that is typically used in a medical context. If you have any questions related to medicine or healthcare, I would be happy to try to help answer them for you!

Leucine is an essential amino acid, meaning it cannot be produced by the human body and must be obtained through the diet. It is one of the three branched-chain amino acids (BCAAs), along with isoleucine and valine. Leucine is critical for protein synthesis and muscle growth, and it helps to regulate blood sugar levels, promote wound healing, and produce growth hormones.

Leucine is found in various food sources such as meat, dairy products, eggs, and certain plant-based proteins like soy and beans. It is also available as a dietary supplement for those looking to increase their intake for athletic performance or muscle recovery purposes. However, it's important to consult with a healthcare professional before starting any new supplement regimen.

I'm sorry for any confusion, but "mammoths" are not a medical term. They are actually large extinct mammals that lived during the Ice Age, similar to elephants and characterized by their long curved tusks and thick fur. If you have any questions about medical terminology or concepts, I'd be happy to help with those instead!

Body water refers to the total amount of water present in the human body. It is an essential component of life and makes up about 60-70% of an adult's body weight. Body water is distributed throughout various fluid compartments within the body, including intracellular fluid (water inside cells), extracellular fluid (water outside cells), and transcellular fluid (water found in specific bodily spaces such as the digestive tract, eyes, and joints). Maintaining proper hydration and balance of body water is crucial for various physiological processes, including temperature regulation, nutrient transportation, waste elimination, and overall health.

In the context of medicine and medical devices, calibration refers to the process of checking, adjusting, or confirming the accuracy of a measurement instrument or system. This is typically done by comparing the measurements taken by the device being calibrated to those taken by a reference standard of known accuracy. The goal of calibration is to ensure that the medical device is providing accurate and reliable measurements, which is critical for making proper diagnoses and delivering effective treatment. Regular calibration is an important part of quality assurance and helps to maintain the overall performance and safety of medical devices.

In the context of medicine and biology, sulfates are ions or compounds that contain the sulfate group (SO4−2). Sulfate is a polyatomic anion with the structure of a sphere. It consists of a central sulfur atom surrounded by four oxygen atoms in a tetrahedral arrangement.

Sulfates can be found in various biological molecules, such as glycosaminoglycans and proteoglycans, which are important components of connective tissue and the extracellular matrix. Sulfate groups play a crucial role in these molecules by providing negative charges that help maintain the structural integrity and hydration of tissues.

In addition to their biological roles, sulfates can also be found in various medications and pharmaceutical compounds. For example, some laxatives contain sulfate salts, such as magnesium sulfate (Epsom salt) or sodium sulfate, which work by increasing the water content in the intestines and promoting bowel movements.

It is important to note that exposure to high levels of sulfates can be harmful to human health, particularly in the form of sulfur dioxide (SO2), a common air pollutant produced by burning fossil fuels. Prolonged exposure to SO2 can cause respiratory problems and exacerbate existing lung conditions.

Plant transpiration is the process by which water vapor escapes from leaves and other aerial parts of plants to the atmosphere. It is a type of evapotranspiration, which refers to both evaporation from land surfaces and transpiration from plants. Water molecules are absorbed by plant roots from the soil, move up through the xylem tissue to the leaves, and then evaporate from the leaf surface through stomatal pores. This process helps in the transportation of nutrients from the soil to various parts of the plant, regulates the temperature of the plant, and maintains the turgor pressure within the cells. Plant transpiration is influenced by environmental factors such as light intensity, temperature, humidity, and wind speed.

Chemical evolution is a term that refers to the set of processes thought to have given rise to life from simple inorganic compounds. It is a prebiotic process, meaning it occurred before the existence of life. The fundamental idea behind chemical evolution is that simple chemicals underwent a series of transformations, eventually leading to the formation of complex organic molecules necessary for life, such as amino acids, nucleotides, and lipids. These building blocks then came together to form the first self-replicating entities, which are considered the precursors to modern cells.

The concept of chemical evolution is based on several key observations and experiments. For example, it has been shown that simple inorganic compounds can be transformed into more complex organic molecules under conditions believed to have existed on early Earth, such as those found near hydrothermal vents or in the presence of ultraviolet radiation. Additionally, experiments using simulated prebiotic conditions have produced a variety of biologically relevant molecules, supporting the plausibility of chemical evolution.

It is important to note that chemical evolution does not necessarily imply that life emerged spontaneously or randomly; rather, it suggests that natural processes led to the formation of complex molecules that eventually gave rise to living organisms. The exact mechanisms and pathways by which this occurred are still subjects of ongoing research and debate in the scientific community.

Potassium isotopes refer to variants of the element potassium that have different numbers of neutrons in their atomic nuclei, while having the same number of protons, which defines the element. The most common and stable potassium isotope is potassium-39 (39K), which contains 19 neutrons and 20 protons. However, there are also other naturally occurring potassium isotopes, including potassium-40 (40K) with 21 neutrons and potassium-41 (41K) with 22 neutrons.

Potassium-40 is a radioactive isotope that undergoes both beta decay and electron capture, making it useful for various scientific applications such as dating rocks and determining the age of archaeological artifacts. It has a half-life of approximately 1.25 billion years.

In medical contexts, potassium isotopes may be used in diagnostic tests or therapeutic procedures, such as positron emission tomography (PET) scans, where radioactive potassium-40 or other radioisotopes are introduced into the body to help visualize and diagnose various conditions. However, it's important to note that the use of potassium isotopes in medical settings is relatively rare due to the availability of other more commonly used radioisotopes.

Potassium radioisotopes refer to unstable isotopes or variants of the element potassium that emit radiation as they decay towards a stable form. A common example is Potassium-40 (40K), which occurs naturally in small amounts in potassium-containing substances. It decays through beta decay and positron emission, as well as electron capture, with a half-life of approximately 1.25 billion years.

Radioisotopes like 40K have medical applications such as in dating archaeological artifacts or studying certain biological processes. However, exposure to high levels of radiation from potassium radioisotopes can be harmful and potentially lead to health issues like radiation sickness or cancer.

Carbonates are a class of chemical compounds that consist of a metal or metalloid combined with carbonate ions (CO32-). These compounds form when carbon dioxide (CO2) reacts with a base, such as a metal hydroxide. The reaction produces water (H2O), carbonic acid (H2CO3), and the corresponding carbonate.

Carbonates are important in many biological and geological processes. In the body, for example, calcium carbonate is a major component of bones and teeth. It also plays a role in maintaining pH balance by reacting with excess acid in the stomach to form carbon dioxide and water.

In nature, carbonates are common minerals found in rocks such as limestone and dolomite. They can also be found in mineral waters and in the shells of marine organisms. Carbonate rocks play an important role in the global carbon cycle, as they can dissolve or precipitate depending on environmental conditions, which affects the amount of carbon dioxide in the atmosphere.

Pneumoencephalography is a diagnostic procedure that is rarely used today, due to the development of less invasive techniques. It involves the introduction of air or another gas into the ventricular system or subarachnoid space of the brain, followed by X-ray imaging to visualize the structures and any abnormalities within the intracranial cavity.

The primary purpose of this procedure was to diagnose conditions affecting the brain's ventricles, such as hydrocephalus, tumors, or inflammation. The introduction of air into the cranium allowed for better visualization of these structures and any potential abnormalities. However, due to its invasive nature, risks associated with the procedure, and the availability of non-invasive imaging techniques like CT and MRI scans, pneumoencephalography has fallen out of favor in modern medicine.

Reproducibility of results in a medical context refers to the ability to obtain consistent and comparable findings when a particular experiment or study is repeated, either by the same researcher or by different researchers, following the same experimental protocol. It is an essential principle in scientific research that helps to ensure the validity and reliability of research findings.

In medical research, reproducibility of results is crucial for establishing the effectiveness and safety of new treatments, interventions, or diagnostic tools. It involves conducting well-designed studies with adequate sample sizes, appropriate statistical analyses, and transparent reporting of methods and findings to allow other researchers to replicate the study and confirm or refute the results.

The lack of reproducibility in medical research has become a significant concern in recent years, as several high-profile studies have failed to produce consistent findings when replicated by other researchers. This has led to increased scrutiny of research practices and a call for greater transparency, rigor, and standardization in the conduct and reporting of medical research.

The liver is a large, solid organ located in the upper right portion of the abdomen, beneath the diaphragm and above the stomach. It plays a vital role in several bodily functions, including:

1. Metabolism: The liver helps to metabolize carbohydrates, fats, and proteins from the food we eat into energy and nutrients that our bodies can use.
2. Detoxification: The liver detoxifies harmful substances in the body by breaking them down into less toxic forms or excreting them through bile.
3. Synthesis: The liver synthesizes important proteins, such as albumin and clotting factors, that are necessary for proper bodily function.
4. Storage: The liver stores glucose, vitamins, and minerals that can be released when the body needs them.
5. Bile production: The liver produces bile, a digestive juice that helps to break down fats in the small intestine.
6. Immune function: The liver plays a role in the immune system by filtering out bacteria and other harmful substances from the blood.

Overall, the liver is an essential organ that plays a critical role in maintaining overall health and well-being.

Hydroxybenzoate ethers are a type of chemical compound that are commonly used as preservatives in pharmaceuticals, cosmetics, and food products. They are formed by the reaction between a hydroxybenzoic acid and an alcohol, resulting in the creation of an ether bond.

The term "hydroxybenzoate" refers to a class of compounds known as phenols, which contain a hydroxyl group (-OH) attached to a benzene ring. Examples of hydroxybenzoic acids include gallic acid, protocatechuic acid, and vanillic acid.

When these hydroxybenzoic acids react with an alcohol, such as ethanol or methanol, they form hydroxybenzoate ethers. The most common examples of hydroxybenzoate ethers used in medical applications include:

* Methylparaben (methyl 4-hydroxybenzoate)
* Ethylparaben (ethyl 4-hydroxybenzoate)
* Propylparaben (propyl 4-hydroxybenzoate)
* Butylparaben (butyl 4-hydroxybenzoate)

These compounds are effective antimicrobial agents and are used to prevent the growth of bacteria, yeasts, and molds in a variety of medical and consumer products. However, there is some concern that parabens may have estrogenic effects and potentially disrupt hormone function, although the evidence for this is not conclusive. As a result, some manufacturers have begun to phase out the use of parabens in their products.

Substrate specificity in the context of medical biochemistry and enzymology refers to the ability of an enzyme to selectively bind and catalyze a chemical reaction with a particular substrate (or a group of similar substrates) while discriminating against other molecules that are not substrates. This specificity arises from the three-dimensional structure of the enzyme, which has evolved to match the shape, charge distribution, and functional groups of its physiological substrate(s).

Substrate specificity is a fundamental property of enzymes that enables them to carry out highly selective chemical transformations in the complex cellular environment. The active site of an enzyme, where the catalysis takes place, has a unique conformation that complements the shape and charge distribution of its substrate(s). This ensures efficient recognition, binding, and conversion of the substrate into the desired product while minimizing unwanted side reactions with other molecules.

Substrate specificity can be categorized as:

1. Absolute specificity: An enzyme that can only act on a single substrate or a very narrow group of structurally related substrates, showing no activity towards any other molecule.
2. Group specificity: An enzyme that prefers to act on a particular functional group or class of compounds but can still accommodate minor structural variations within the substrate.
3. Broad or promiscuous specificity: An enzyme that can act on a wide range of structurally diverse substrates, albeit with varying catalytic efficiencies.

Understanding substrate specificity is crucial for elucidating enzymatic mechanisms, designing drugs that target specific enzymes or pathways, and developing biotechnological applications that rely on the controlled manipulation of enzyme activities.

In the field of medicine, "time factors" refer to the duration of symptoms or time elapsed since the onset of a medical condition, which can have significant implications for diagnosis and treatment. Understanding time factors is crucial in determining the progression of a disease, evaluating the effectiveness of treatments, and making critical decisions regarding patient care.

For example, in stroke management, "time is brain," meaning that rapid intervention within a specific time frame (usually within 4.5 hours) is essential to administering tissue plasminogen activator (tPA), a clot-busting drug that can minimize brain damage and improve patient outcomes. Similarly, in trauma care, the "golden hour" concept emphasizes the importance of providing definitive care within the first 60 minutes after injury to increase survival rates and reduce morbidity.

Time factors also play a role in monitoring the progression of chronic conditions like diabetes or heart disease, where regular follow-ups and assessments help determine appropriate treatment adjustments and prevent complications. In infectious diseases, time factors are crucial for initiating antibiotic therapy and identifying potential outbreaks to control their spread.

Overall, "time factors" encompass the significance of recognizing and acting promptly in various medical scenarios to optimize patient outcomes and provide effective care.

Acetates, in a medical context, most commonly refer to compounds that contain the acetate group, which is an functional group consisting of a carbon atom bonded to two hydrogen atoms and an oxygen atom (-COO-). An example of an acetate is sodium acetate (CH3COONa), which is a salt formed from acetic acid (CH3COOH) and is often used as a buffering agent in medical solutions.

Acetates can also refer to a group of medications that contain acetate as an active ingredient, such as magnesium acetate, which is used as a laxative, or calcium acetate, which is used to treat high levels of phosphate in the blood.

In addition, acetates can also refer to a process called acetylation, which is the addition of an acetyl group (-COCH3) to a molecule. This process can be important in the metabolism and regulation of various substances within the body.

Selenium radioisotopes are unstable forms of the element selenium that emit radiation as they decay into more stable forms. These isotopes can be produced through various nuclear reactions, such as irradiating a stable selenium target with protons or alpha particles. Some examples of selenium radioisotopes include selenium-75, selenium-79, and selenium-81.

Selenium-75 is commonly used in medical imaging to study the function of the thyroid gland, as it accumulates in this gland and can be detected using a gamma camera. Selenium-79 and selenium-81 have potential uses in cancer treatment, as they can be incorporated into compounds that selectively target and destroy cancer cells. However, more research is needed to fully understand the potential benefits and risks of using these radioisotopes in medical treatments.

It's important to note that handling and using radioisotopes requires special training and precautions, as they can be dangerous if not handled properly. Exposure to radiation from radioisotopes can increase the risk of cancer and other health problems, so it's essential to use them only under controlled conditions and with appropriate safety measures in place.

I'm sorry for any confusion, but "geological processes" is not a term typically used in medical definitions. Geological processes refer to the natural events that shape the Earth's surface and interior over time, such as volcanic activity, plate tectonics, erosion, and sedimentation. These processes are studied within the field of geology. If you have any questions related to medicine or health, I would be happy to try to help answer those!

Biocatalysis is the use of living organisms or their components, such as enzymes, to accelerate chemical reactions. In other words, it is the process by which biological systems, including cells, tissues, and organs, catalyze chemical transformations. Biocatalysts, such as enzymes, can increase the rate of a reaction by lowering the activation energy required for the reaction to occur. They are highly specific and efficient, making them valuable tools in various industries, including pharmaceuticals, food and beverage, and biofuels.

In medicine, biocatalysis is used in the production of drugs, such as antibiotics and hormones, as well as in diagnostic tests. Enzymes are also used in medical treatments, such as enzyme replacement therapy for genetic disorders that affect enzyme function. Overall, biocatalysis plays a critical role in many areas of medicine and healthcare.

"Time" is not a medical term or concept. It is a fundamental concept in physics that refers to the ongoing sequence of events taking place. While there are medical terms that include the word "time," such as "reaction time" or "pregnancy due date," these refer to specific measurements or periods within a medical context, rather than the concept of time itself.

Sulfur is not typically referred to in the context of a medical definition, as it is an element found in nature and not a specific medical condition or concept. However, sulfur does have some relevance to certain medical topics:

* Sulfur is an essential element that is a component of several amino acids (the building blocks of proteins) and is necessary for the proper functioning of enzymes and other biological processes in the body.
* Sulfur-containing compounds, such as glutathione, play important roles in antioxidant defense and detoxification in the body.
* Some medications and supplements contain sulfur or sulfur-containing compounds, such as dimethyl sulfoxide (DMSO), which is used topically for pain relief and inflammation.
* Sulfur baths and other forms of sulfur-based therapies have been used historically in alternative medicine to treat various conditions, although their effectiveness is not well-established by scientific research.

It's important to note that while sulfur itself is not a medical term, it can be relevant to certain medical topics and should be discussed with a healthcare professional if you have any questions or concerns about its use in medications, supplements, or therapies.

Oxygen is a colorless, odorless, tasteless gas that constitutes about 21% of the earth's atmosphere. It is a crucial element for human and most living organisms as it is vital for respiration. Inhaled oxygen enters the lungs and binds to hemoglobin in red blood cells, which carries it to tissues throughout the body where it is used to convert nutrients into energy and carbon dioxide, a waste product that is exhaled.

Medically, supplemental oxygen therapy may be provided to patients with conditions such as chronic obstructive pulmonary disease (COPD), pneumonia, heart failure, or other medical conditions that impair the body's ability to extract sufficient oxygen from the air. Oxygen can be administered through various devices, including nasal cannulas, face masks, and ventilators.

Temperature, in a medical context, is a measure of the degree of hotness or coldness of a body or environment. It is usually measured using a thermometer and reported in degrees Celsius (°C), degrees Fahrenheit (°F), or kelvin (K). In the human body, normal core temperature ranges from about 36.5-37.5°C (97.7-99.5°F) when measured rectally, and can vary slightly depending on factors such as time of day, physical activity, and menstrual cycle. Elevated body temperature is a common sign of infection or inflammation, while abnormally low body temperature can indicate hypothermia or other medical conditions.

I believe there may be a slight misunderstanding in your question. "Plant leaves" are not a medical term, but rather a general biological term referring to a specific organ found in plants.

Leaves are organs that are typically flat and broad, and they are the primary site of photosynthesis in most plants. They are usually green due to the presence of chlorophyll, which is essential for capturing sunlight and converting it into chemical energy through photosynthesis.

While leaves do not have a direct medical definition, understanding their structure and function can be important in various medical fields, such as pharmacognosy (the study of medicinal plants) or environmental health. For example, certain plant leaves may contain bioactive compounds that have therapeutic potential, while others may produce allergens or toxins that can impact human health.

I'm sorry for any confusion, but the term "Pacific Ocean" is a geographical term referring to the largest single body of saltwater on Earth, extending from the Arctic in the north to the Antarctic in the south. It covers an area of about 63,800,000 square miles (165,200,000 square kilometers).

If you're looking for a medical term or definition, I'd be happy to help with that as well. Could you please provide more context?

Iodine isotopes are different forms of the chemical element iodine, which have different numbers of neutrons in their nuclei. Iodine has a total of 53 protons in its nucleus, and its stable isotope, iodine-127, has 74 neutrons, giving it a mass number of 127. However, there are also radioactive isotopes of iodine, which have different numbers of neutrons and are therefore unstable.

Radioactive isotopes of iodine emit radiation as they decay towards a stable state. For example, iodine-131 is a commonly used isotope in medical imaging and therapy, with a half-life of about 8 days. It decays by emitting beta particles and gamma rays, making it useful for treating thyroid cancer and other conditions that involve overactive thyroid glands.

Other radioactive iodine isotopes include iodine-123, which has a half-life of about 13 hours and is used in medical imaging, and iodine-125, which has a half-life of about 60 days and is used in brachytherapy (a type of radiation therapy that involves placing radioactive sources directly into or near tumors).

It's important to note that exposure to radioactive iodine isotopes can be harmful, especially if it occurs through inhalation or ingestion. This is because the iodine can accumulate in the thyroid gland and cause damage over time. Therefore, appropriate safety measures must be taken when handling or working with radioactive iodine isotopes.

Gallium isotopes are different forms of the element gallium that have the same number of protons in their nucleus (which defines the element) but a different number of neutrons. This results in a slight difference in atomic mass.

For example, the most stable and abundant gallium isotope is Gallium-69, which has 31 protons and 38 neutrons in its nucleus, giving it an atomic mass of 68.925 g/mol. However, there are also other less common isotopes such as Gallium-67, which has 31 protons and 36 neutrons, giving it an atomic mass of 66.928 g/mol.

In medical context, Gallium-67 is used as a radioactive tracer in diagnostic imaging to help identify certain types of infection, inflammation, or cancer. The gallium-67 is injected into the patient's body and accumulates in areas with increased blood flow, such as sites of infection or tumors. A special camera then detects the gamma rays emitted by the radioactive gallium and creates images that can help doctors diagnose and monitor various medical conditions.

Ecology is not a medical term, but rather a term used in the field of biology. It refers to the study of the relationships between living organisms and their environment. This includes how organisms interact with each other and with their physical surroundings, such as climate, soil, and water. Ecologists may study the distribution and abundance of species, the flow of energy through an ecosystem, and the effects of human activities on the environment. While ecology is not a medical field, understanding ecological principles can be important for addressing public health issues related to the environment, such as pollution, climate change, and infectious diseases.

Photosynthesis is not strictly a medical term, but it is a fundamental biological process with significant implications for medicine, particularly in understanding energy production in cells and the role of oxygen in sustaining life. Here's a general biological definition:

Photosynthesis is a process by which plants, algae, and some bacteria convert light energy, usually from the sun, into chemical energy in the form of organic compounds, such as glucose (or sugar), using water and carbon dioxide. This process primarily takes place in the chloroplasts of plant cells, specifically in structures called thylakoids. The overall reaction can be summarized as:

6 CO2 + 6 H2O + light energy → C6H12O6 + 6 O2

In this equation, carbon dioxide (CO2) and water (H2O) are the reactants, while glucose (C6H12O6) and oxygen (O2) are the products. Photosynthesis has two main stages: the light-dependent reactions and the light-independent reactions (Calvin cycle). The light-dependent reactions occur in the thylakoid membrane and involve the conversion of light energy into ATP and NADPH, which are used to power the Calvin cycle. The Calvin cycle takes place in the stroma of chloroplasts and involves the synthesis of glucose from CO2 and water using the ATP and NADPH generated during the light-dependent reactions.

Understanding photosynthesis is crucial for understanding various biological processes, including cellular respiration, plant metabolism, and the global carbon cycle. Additionally, research into artificial photosynthesis has potential applications in renewable energy production and environmental remediation.

Toluene is not a medical condition or disease, but it is a chemical compound that is widely used in various industrial and commercial applications. Medically, toluene can be relevant as a substance of abuse due to its intoxicating effects when inhaled or sniffed. It is a colorless liquid with a distinctive sweet aroma, and it is a common solvent found in many products such as paint thinners, adhesives, and rubber cement.

In the context of medical toxicology, toluene exposure can lead to various health issues, including neurological damage, cognitive impairment, memory loss, nausea, vomiting, and hearing and vision problems. Chronic exposure to toluene can also cause significant harm to the developing fetus during pregnancy, leading to developmental delays, behavioral problems, and physical abnormalities.

Phosphorus isotopes are different forms of the element phosphorus that have different numbers of neutrons in their atomic nuclei, while the number of protons remains the same. The most common and stable isotope of phosphorus is 31P, which contains 15 protons and 16 neutrons. However, there are also several other isotopes of phosphorus that exist, including 32P and 33P, which are radioactive and have 15 protons and 17 or 18 neutrons, respectively. These radioactive isotopes are often used in medical research and treatment, such as in the form of radiopharmaceuticals to diagnose and treat various diseases.

Molecular sequence data refers to the specific arrangement of molecules, most commonly nucleotides in DNA or RNA, or amino acids in proteins, that make up a biological macromolecule. This data is generated through laboratory techniques such as sequencing, and provides information about the exact order of the constituent molecules. This data is crucial in various fields of biology, including genetics, evolution, and molecular biology, allowing for comparisons between different organisms, identification of genetic variations, and studies of gene function and regulation.

Dysprosium is a chemical element with the symbol Dy and atomic number 66. It is a rare earth element that belongs to the lanthanide series. Dysprosium is a naturally occurring, silvery-white, malleable, and ductile metal. It is not found in its free form in nature, but it is often found combined with other elements in minerals such as monazite and bastnasite.

Dysprosium has a number of important uses due to its unique magnetic properties. It is used in the production of high-strength magnets, which are used in various applications including electric motors, generators, and wind turbines. Dysprosium is also used in the nuclear industry as a neutron absorber in control rods for nuclear reactors.

In medical terms, dysprosium has no known therapeutic uses or health benefits. However, it may be used in some medical devices or equipment due to its magnetic properties. For example, dysprosium is sometimes used in the production of magnetic resonance imaging (MRI) contrast agents.

Climate, in the context of environmental science and medicine, refers to the long-term average of weather conditions (such as temperature, humidity, atmospheric pressure, wind, rainfall, and other meteorological elements) in a given region over a period of years to decades. It is the statistical description of the weather patterns that occur in a particular location over long periods of time.

In medical terms, climate can have significant impacts on human health, both physical and mental. For example, extreme temperatures, air pollution, and ultraviolet radiation levels associated with certain climates can increase the risk of respiratory and cardiovascular diseases, heat-related illnesses, and skin cancer. Similarly, changes in climate patterns can affect the distribution and prevalence of infectious diseases, such as malaria and Lyme disease.

Climate change, which refers to significant long-term changes in the statistical distribution of weather patterns over periods ranging from decades to millions of years, can have even more profound impacts on human health, including increased rates of heat-related illnesses and deaths, worsening air quality, and altered transmission patterns of infectious diseases.

Neutron Activation Analysis (NAA) is not strictly a medical definition, but it's a technique used in the field of nuclear medicine and forensic medicine for material analysis and identification. Here's a general definition:

Neutron Activation Analysis is a non-destructive analytical method that uses nuclear reactions to identify and determine the concentration of elements within a sample. The sample is irradiated with neutrons, which induce nuclear reactions that produce radioactive isotopes of the elements present in the sample. The gamma radiation emitted by these radioisotopes is then measured and analyzed to quantify the elemental composition of the sample. This technique is particularly useful for detecting and measuring trace elements and isotopes, making it valuable in various fields such as archaeology, geology, nuclear medicine, and forensic science.

Nuclear Magnetic Resonance (NMR) Biomolecular is a research technique that uses magnetic fields and radio waves to study the structure and dynamics of biological molecules, such as proteins and nucleic acids. This technique measures the magnetic properties of atomic nuclei within these molecules, specifically their spin, which can be influenced by the application of an external magnetic field.

When a sample is placed in a strong magnetic field, the nuclei absorb and emit electromagnetic radiation at specific frequencies, known as resonance frequencies, which are determined by the molecular structure and environment of the nuclei. By analyzing these resonance frequencies and their interactions, researchers can obtain detailed information about the three-dimensional structure, dynamics, and interactions of biomolecules.

NMR spectroscopy is a non-destructive technique that allows for the study of biological molecules in solution, which makes it an important tool for understanding the function and behavior of these molecules in their natural environment. Additionally, NMR can be used to study the effects of drugs, ligands, and other small molecules on biomolecular structure and dynamics, making it a valuable tool in drug discovery and development.

A tooth is a hard, calcified structure found in the jaws (upper and lower) of many vertebrates and used for biting and chewing food. In humans, a typical tooth has a crown, one or more roots, and three layers: the enamel (the outermost layer, hardest substance in the body), the dentin (the layer beneath the enamel), and the pulp (the innermost layer, containing nerves and blood vessels). Teeth are essential for proper nutrition, speech, and aesthetics. There are different types of teeth, including incisors, canines, premolars, and molars, each designed for specific functions in the mouth.

Glucose is a simple monosaccharide (or single sugar) that serves as the primary source of energy for living organisms. It's a fundamental molecule in biology, often referred to as "dextrose" or "grape sugar." Glucose has the molecular formula C6H12O6 and is vital to the functioning of cells, especially those in the brain and nervous system.

In the body, glucose is derived from the digestion of carbohydrates in food, and it's transported around the body via the bloodstream to cells where it can be used for energy. Cells convert glucose into a usable form through a process called cellular respiration, which involves a series of metabolic reactions that generate adenosine triphosphate (ATP)—the main currency of energy in cells.

Glucose is also stored in the liver and muscles as glycogen, a polysaccharide (multiple sugar) that can be broken down back into glucose when needed for energy between meals or during physical activity. Maintaining appropriate blood glucose levels is crucial for overall health, and imbalances can lead to conditions such as diabetes mellitus.

Metabolic Flux Analysis (MFA) is not a medical term, but rather a term used in biochemistry and molecular biology. It refers to a mathematical modeling approach used to quantify the flow rates of metabolites through metabolic pathways in biological systems, such as cells or organisms. MFA uses measured data on the consumption and production rates of metabolites, along with knowledge of the reactions that make up the metabolic network, to estimate the fluxes (rates of reaction) through each pathway. This approach can help elucidate the regulation and dynamics of metabolic networks in response to genetic or environmental perturbations, and has applications in fields such as metabolic engineering and systems biology.

Stereoisomerism is a type of isomerism (structural arrangement of atoms) in which molecules have the same molecular formula and sequence of bonded atoms, but differ in the three-dimensional orientation of their atoms in space. This occurs when the molecule contains asymmetric carbon atoms or other rigid structures that prevent free rotation, leading to distinct spatial arrangements of groups of atoms around a central point. Stereoisomers can have different chemical and physical properties, such as optical activity, boiling points, and reactivities, due to differences in their shape and the way they interact with other molecules.

There are two main types of stereoisomerism: enantiomers (mirror-image isomers) and diastereomers (non-mirror-image isomers). Enantiomers are pairs of stereoisomers that are mirror images of each other, but cannot be superimposed on one another. Diastereomers, on the other hand, are non-mirror-image stereoisomers that have different physical and chemical properties.

Stereoisomerism is an important concept in chemistry and biology, as it can affect the biological activity of molecules, such as drugs and natural products. For example, some enantiomers of a drug may be active, while others are inactive or even toxic. Therefore, understanding stereoisomerism is crucial for designing and synthesizing effective and safe drugs.

Environmental biodegradation is the breakdown of materials, especially man-made substances such as plastics and industrial chemicals, by microorganisms such as bacteria and fungi in order to use them as a source of energy or nutrients. This process occurs naturally in the environment and helps to break down organic matter into simpler compounds that can be more easily absorbed and assimilated by living organisms.

Biodegradation in the environment is influenced by various factors, including the chemical composition of the substance being degraded, the environmental conditions (such as temperature, moisture, and pH), and the type and abundance of microorganisms present. Some substances are more easily biodegraded than others, and some may even be resistant to biodegradation altogether.

Biodegradation is an important process for maintaining the health and balance of ecosystems, as it helps to prevent the accumulation of harmful substances in the environment. However, some man-made substances, such as certain types of plastics and industrial chemicals, may persist in the environment for long periods of time due to their resistance to biodegradation, leading to negative impacts on wildlife and ecosystems.

In recent years, there has been increasing interest in developing biodegradable materials that can break down more easily in the environment as a way to reduce waste and minimize environmental harm. These efforts have led to the development of various biodegradable plastics, coatings, and other materials that are designed to degrade under specific environmental conditions.

I'm sorry for any confusion, but "Fresh Water" is not a medical term. It is a term used to describe water that contains low concentrations of dissolved salts and other dissolved minerals. It is distinguished from saline water, which includes saltwater found in the ocean and brackish water found in estuaries. Fresh water is essential for many biological processes and is the primary source of water for human consumption, agriculture, and industrial use.

In the context of medicine, iron is an essential micromineral and key component of various proteins and enzymes. It plays a crucial role in oxygen transport, DNA synthesis, and energy production within the body. Iron exists in two main forms: heme and non-heme. Heme iron is derived from hemoglobin and myoglobin in animal products, while non-heme iron comes from plant sources and supplements.

The recommended daily allowance (RDA) for iron varies depending on age, sex, and life stage:

* For men aged 19-50 years, the RDA is 8 mg/day
* For women aged 19-50 years, the RDA is 18 mg/day
* During pregnancy, the RDA increases to 27 mg/day
* During lactation, the RDA for breastfeeding mothers is 9 mg/day

Iron deficiency can lead to anemia, characterized by fatigue, weakness, and shortness of breath. Excessive iron intake may result in iron overload, causing damage to organs such as the liver and heart. Balanced iron levels are essential for maintaining optimal health.

Proteins are complex, large molecules that play critical roles in the body's functions. They are made up of amino acids, which are organic compounds that are the building blocks of proteins. Proteins are required for the structure, function, and regulation of the body's tissues and organs. They are essential for the growth, repair, and maintenance of body tissues, and they play a crucial role in many biological processes, including metabolism, immune response, and cellular signaling. Proteins can be classified into different types based on their structure and function, such as enzymes, hormones, antibodies, and structural proteins. They are found in various foods, especially animal-derived products like meat, dairy, and eggs, as well as plant-based sources like beans, nuts, and grains.

In the context of medicine, "lead" most commonly refers to lead exposure or lead poisoning. Lead is a heavy metal that can be harmful to the human body, even at low levels. It can enter the body through contaminated air, water, food, or soil, and it can also be absorbed through the skin.

Lead poisoning occurs when lead builds up in the body over time, causing damage to the brain, nervous system, red blood cells, and kidneys. Symptoms of lead poisoning may include abdominal pain, constipation, fatigue, headache, irritability, memory problems, and in severe cases, seizures, coma, or even death.

Lead exposure is particularly dangerous for children, as their developing bodies are more sensitive to the harmful effects of lead. Even low levels of lead exposure can cause learning disabilities, behavioral problems, and developmental delays in children. Therefore, it's important to minimize lead exposure and seek medical attention if lead poisoning is suspected.

Indium is not a medical term, but it is a chemical element with the symbol In and atomic number 49. It is a soft, silvery-white, post-transition metal that is rarely found in its pure form in nature. It is primarily used in the production of electronics, such as flat panel displays, and in nuclear medicine as a radiation source for medical imaging.

In nuclear medicine, indium-111 is used in the labeling of white blood cells to diagnose and locate abscesses, inflammation, and infection. The indium-111 labeled white blood cells are injected into the patient's body, and then a gamma camera is used to track their movement and identify areas of infection or inflammation.

Therefore, while indium itself is not a medical term, it does have important medical applications in diagnostic imaging.

Metabolomics is a branch of "omics" sciences that deals with the comprehensive and quantitative analysis of all metabolites, which are the small molecule intermediates and products of metabolism, in a biological sample. It involves the identification and measurement of these metabolites using various analytical techniques such as mass spectrometry and nuclear magnetic resonance spectroscopy. The resulting data provides a functional readout of the physiological state of an organism, tissue or cell, and can be used to identify biomarkers of disease, understand drug action and toxicity, and reveal new insights into metabolic pathways and regulatory networks.

Bacteria are single-celled microorganisms that are among the earliest known life forms on Earth. They are typically characterized as having a cell wall and no membrane-bound organelles. The majority of bacteria have a prokaryotic organization, meaning they lack a nucleus and other membrane-bound organelles.

Bacteria exist in diverse environments and can be found in every habitat on Earth, including soil, water, and the bodies of plants and animals. Some bacteria are beneficial to their hosts, while others can cause disease. Beneficial bacteria play important roles in processes such as digestion, nitrogen fixation, and biogeochemical cycling.

Bacteria reproduce asexually through binary fission or budding, and some species can also exchange genetic material through conjugation. They have a wide range of metabolic capabilities, with many using organic compounds as their source of energy, while others are capable of photosynthesis or chemosynthesis.

Bacteria are highly adaptable and can evolve rapidly in response to environmental changes. This has led to the development of antibiotic resistance in some species, which poses a significant public health challenge. Understanding the biology and behavior of bacteria is essential for developing strategies to prevent and treat bacterial infections and diseases.

Phytic acid, also known as phytate in its salt form, is a natural substance found in plant-based foods such as grains, legumes, nuts, and seeds. It's a storage form of phosphorus for the plant and is often referred to as an "anti-nutrient" because it can bind to certain minerals like calcium, iron, magnesium, and zinc in the gastrointestinal tract and prevent their absorption. This can potentially lead to mineral deficiencies if a diet is consistently high in phytic acid-rich foods and low in mineral-rich foods. However, it's important to note that phytic acid also has antioxidant properties and may have health benefits when consumed as part of a balanced diet.

The bioavailability of minerals from phytic acid-rich foods can be improved through various methods such as soaking, sprouting, fermenting, or cooking, which can help break down some of the phytic acid and release the bound minerals.

Feeding behavior refers to the various actions and mechanisms involved in the intake of food and nutrition for the purpose of sustaining life, growth, and health. This complex process encompasses a coordinated series of activities, including:

1. Food selection: The identification, pursuit, and acquisition of appropriate food sources based on sensory cues (smell, taste, appearance) and individual preferences.
2. Preparation: The manipulation and processing of food to make it suitable for consumption, such as chewing, grinding, or chopping.
3. Ingestion: The act of transferring food from the oral cavity into the digestive system through swallowing.
4. Digestion: The mechanical and chemical breakdown of food within the gastrointestinal tract to facilitate nutrient absorption and eliminate waste products.
5. Assimilation: The uptake and utilization of absorbed nutrients by cells and tissues for energy production, growth, repair, and maintenance.
6. Elimination: The removal of undigested material and waste products from the body through defecation.

Feeding behavior is regulated by a complex interplay between neural, hormonal, and psychological factors that help maintain energy balance and ensure adequate nutrient intake. Disruptions in feeding behavior can lead to various medical conditions, such as malnutrition, obesity, eating disorders, and gastrointestinal motility disorders.

Yttrium isotopes are different forms of the element yttrium, which have the same number of protons in their atomic nuclei (which is 39 and defines the element), but different numbers of neutrons. This results in a difference in the mass number of the isotopes. For example, the most common yttrium isotope is Y-89, which has 39 protons and 50 neutrons, giving it a mass number of 89. However, there are also other yttrium isotopes such as Y-88, Y-90, Y-91 etc., with different numbers of neutrons and thus different mass numbers. Some yttrium isotopes are stable, while others are unstable and radioactive, meaning they will decay into other elements over time.

'Escherichia coli' (E. coli) is a type of gram-negative, facultatively anaerobic, rod-shaped bacterium that commonly inhabits the intestinal tract of humans and warm-blooded animals. It is a member of the family Enterobacteriaceae and one of the most well-studied prokaryotic model organisms in molecular biology.

While most E. coli strains are harmless and even beneficial to their hosts, some serotypes can cause various forms of gastrointestinal and extraintestinal illnesses in humans and animals. These pathogenic strains possess virulence factors that enable them to colonize and damage host tissues, leading to diseases such as diarrhea, urinary tract infections, pneumonia, and sepsis.

E. coli is a versatile organism with remarkable genetic diversity, which allows it to adapt to various environmental niches. It can be found in water, soil, food, and various man-made environments, making it an essential indicator of fecal contamination and a common cause of foodborne illnesses. The study of E. coli has contributed significantly to our understanding of fundamental biological processes, including DNA replication, gene regulation, and protein synthesis.

I apologize for any confusion, but "plants" is not a term that has a medical definition. The term "plants" refers to a large and diverse group of organisms that obtain their energy through photosynthesis, which is the process of converting sunlight into chemical energy. Plants are typically characterized by having cells with cell walls containing cellulose, chloroplasts containing the pigment chlorophyll, and the ability to synthesize their own food through photosynthesis.

In a medical or biological context, you might be thinking of "plant-based" or "phytomedicine," which refer to the use of plants or plant extracts as a form of medicine or treatment. Phytomedicines have been used for thousands of years in many traditional systems of medicine, and some plant-derived compounds have been found to have therapeutic benefits in modern medicine as well. However, "plants" itself does not have a medical definition.

Iodine radioisotopes are radioactive isotopes of the element iodine, which decays and emits radiation in the form of gamma rays. Some commonly used iodine radioisotopes include I-123, I-125, I-131. These radioisotopes have various medical applications such as in diagnostic imaging, therapy for thyroid disorders, and cancer treatment.

For example, I-131 is commonly used to treat hyperthyroidism and differentiated thyroid cancer due to its ability to destroy thyroid tissue. On the other hand, I-123 is often used in nuclear medicine scans of the thyroid gland because it emits gamma rays that can be detected by a gamma camera, allowing for detailed images of the gland's structure and function.

It is important to note that handling and administering radioisotopes require specialized training and safety precautions due to their radiation-emitting properties.

Actinium is a naturally occurring radioactive metallic element with the symbol Ac and atomic number 89. It was discovered in 1899 by André-Louis Debierne, a French chemist, who isolated it from uranium ore. Actinium is one of the actinides, a series of elements in the periodic table that are characterized by their radioactivity and their position in the f-block of the periodic table.

Actinium has no biological role in humans or other organisms, and exposure to its radiation can be harmful. It is not found in significant quantities in the environment, but it can be produced artificially through nuclear reactions. Actinium has a few potential medical applications, including as a component of radioactive compounds used for cancer treatment. However, its use in medicine is limited due to its radioactivity and toxicity.

Phenylalanine is an essential amino acid, meaning it cannot be produced by the human body and must be obtained through diet or supplementation. It's one of the building blocks of proteins and is necessary for the production of various molecules in the body, such as neurotransmitters (chemical messengers in the brain).

Phenylalanine has two forms: L-phenylalanine and D-phenylalanine. L-phenylalanine is the form found in proteins and is used by the body for protein synthesis, while D-phenylalanine has limited use in humans and is not involved in protein synthesis.

Individuals with a rare genetic disorder called phenylketonuria (PKU) must follow a low-phenylalanine diet or take special medical foods because they are unable to metabolize phenylalanine properly, leading to its buildup in the body and potential neurological damage.

Strontium radioisotopes are radioactive isotopes of the element strontium. Strontium is an alkaline earth metal that is found in nature and has several isotopes, some of which are stable and some of which are radioactive. The radioactive isotopes of strontium, also known as strontium radionuclides, decay and emit radiation in the form of beta particles.

Strontium-89 (^89Sr) and strontium-90 (^90Sr) are two common radioisotopes of strontium that are used in medical applications. Strontium-89 is a pure beta emitter with a half-life of 50.5 days, which makes it useful for the treatment of bone pain associated with metastatic cancer. When administered, strontium-89 is taken up by bones and irradiates the bone tissue, reducing pain and improving quality of life in some patients.

Strontium-90, on the other hand, has a longer half-life of 28.8 years and emits more powerful beta particles than strontium-89. It is used as a component in radioactive waste and in some nuclear weapons, but it is not used in medical applications due to its long half-life and high radiation dose.

It's important to note that exposure to strontium radioisotopes can be harmful to human health, especially if ingested or inhaled. Therefore, handling and disposal of strontium radioisotopes require special precautions and regulations.

Chromium radioisotopes are unstable isotopes or variants of the chemical element chromium that emit radiation as they decay into more stable forms. These isotopes have an excess of energy and particles, making them unstable and capable of emitting ionizing radiation in the form of gamma rays or subatomic particles such as alpha or beta particles.

Chromium has several radioisotopes, including chromium-50, chromium-51, and chromium-53, among others. Chromium-51 is one of the most commonly used radioisotopes in medical applications, particularly in diagnostic procedures such as red blood cell labeling and imaging studies.

It's important to note that handling and using radioisotopes require proper training and safety measures due to their potential radiation hazards.

Plutonium is not a medical term, but it is a chemical element with the symbol Pu and atomic number 94. It is a dense, silvery-red, transuranic radioactive metal that occurs in minute quantities naturally as an intermediate product of uranium decay, or can be produced by neutron capture in uranium-238.

Plutonium is highly toxic and radioactive, and it has been classified as a Category II carcinogen by the International Agency for Research on Cancer (IARC). It is mainly used in the production of nuclear weapons and as fuel in nuclear reactors. Medical uses of plutonium are limited due to its high radioactivity and toxicity.

In medicine, plutonium-210 has been used in some cancer therapies, such as brachytherapy, where a small amount of the isotope is implanted directly into the tumor. However, due to its high radioactivity and potential for causing radiation damage to surrounding tissues, its use in medicine is highly regulated and relatively rare.

I'm sorry for any confusion, but "Mars" is not a medical term. It is the fourth planet from the Sun in our solar system and is often called the "Red Planet" due to its reddish appearance from iron oxide (rust) on its surface. If you have any medical questions or terms you would like defined, I'd be happy to help!

'Canavalia' is a genus of herbaceous plants in the legume family, also known as jackbeans or horse eye beans. While the plant itself has some medicinal uses, such as being used as a traditional remedy for skin conditions and inflammation, it is not typically the subject of medical definition.

However, a compound called canavalia ensiformis agglutinin (Con A) can be extracted from the seeds of Canavalia ensiformis (also known as jackbean). Con A is a type of lectin, which is a protein that binds to carbohydrates and has various biological effects.

Con A has been studied for its potential medical applications, such as in cancer research. It can bind to specific structures on the surface of cancer cells and induce cell death, making it a subject of interest in immunotherapy and other cancer treatments. However, more research is needed before Con A can be used as a standard treatment for cancer or any other medical condition.

Peptides are short chains of amino acid residues linked by covalent bonds, known as peptide bonds. They are formed when two or more amino acids are joined together through a condensation reaction, which results in the elimination of a water molecule and the formation of an amide bond between the carboxyl group of one amino acid and the amino group of another.

Peptides can vary in length from two to about fifty amino acids, and they are often classified based on their size. For example, dipeptides contain two amino acids, tripeptides contain three, and so on. Oligopeptides typically contain up to ten amino acids, while polypeptides can contain dozens or even hundreds of amino acids.

Peptides play many important roles in the body, including serving as hormones, neurotransmitters, enzymes, and antibiotics. They are also used in medical research and therapeutic applications, such as drug delivery and tissue engineering.

Selenium is a trace element that is essential for the proper functioning of the human body. According to the medical definitions provided by the National Institutes of Health (NIH), selenium is a component of several major metabolic pathways, including thyroid hormone metabolism, antioxidant defense systems, and immune function.

Selenium is found in a variety of foods, including nuts (particularly Brazil nuts), cereals, fish, and meat. It exists in several forms, with selenomethionine being the most common form found in food. Other forms include selenocysteine, which is incorporated into proteins, and selenite and selenate, which are inorganic forms of selenium.

The recommended dietary allowance (RDA) for selenium is 55 micrograms per day for adults. While selenium deficiency is rare, chronic selenium deficiency can lead to conditions such as Keshan disease, a type of cardiomyopathy, and Kaschin-Beck disease, which affects the bones and joints.

It's important to note that while selenium is essential for health, excessive intake can be harmful. High levels of selenium can cause symptoms such as nausea, vomiting, hair loss, and neurological damage. The tolerable upper intake level (UL) for selenium is 400 micrograms per day for adults.

Coprophagia is a medical term that refers to the consumption or eating of feces. This behavior is generally considered abnormal in humans and most other animals, but it is a natural part of the life cycle for some species such as certain insects and rodents. In animals, coprophagia can sometimes be a sign of an underlying medical condition, nutritional deficiency, or behavioral issue. In humans, coprophagia is often associated with mental health disorders such as pica or obsessive-compulsive disorder (OCD). It's important to note that coprophagia can pose serious health risks, including the transmission of diseases and parasites, so it should be addressed with a healthcare professional if it occurs.

  • What are labelled compounds? (
  • Labelled compounds are compounds in which one or more of the atoms of a portion of the molecules is replaced with or substituted by a detectable quantity of stable or radioactive isotope(s) of the elements present in them chemically, enzymatically or biosynthetically, using suitable precursors, reagents, reaction schemes and procedures. (
  • What are the applications of labelled compounds? (
  • The isotopically labelled compounds have numerous and varied applications as tracers. (
  • The tables 1 & 2 show some of the important applications of labelled compounds and labelled biomolecules in different disciplines. (
  • The Applications in human mineral Isotopic labeling of compounds is a non-radioactive method of labeling, provides site-specific investigation of structures, makes molecules easily detectable by mass spectrometry and NMR, maintaining the physico-chemical properties of the target molecule, and is cost-effective and easy to use. (
  • The synthesis of folic acid, multiply labelled with stable isotopes The isotope-labeled compounds fluoxetine-d5 and norfluoxetine-d5 were used to study matrix effects caused by co-eluting compounds originating from raw and Isotope labeling methods for large systems. (
  • 13C-Phosphorylated compounds and 13C-organic acids labeling is assessed using an Agilent 1290 Infinity II coupled to an ABSciex QTRAP 6500+ LC-MS/MS system. (
  • According to the new market research report Stable Isotope Labeled Compounds Market is projected to grow at a CAGR of 3.0% during the forecast period to reach USD 312 million by 2024 from USD 269 million in 2019. (
  • However, the high cost of stable isotope-labeled compounds is expected to restrain the growth of this market during the forecast period. (
  • Cambridge Isotope Laboratories (CIL) (US), Merck KGaA (Germany), and URENCO (UK) are the key players operating in the stable isotope labeled compounds market. (
  • Cambridge Isotope Laboratories (CIL) held the leading position in the stable isotope labeled compounds market in 2018. (
  • With the acquisition of Sigma-Aldrich Corporation (US), Merck KGaA secured the second position in the global stable isotope labeled compounds market in 2018. (
  • Sigma-Aldrich was one of the leading developers, manufacturers, and distributors of stable isotope-labeled compounds. (
  • Acquisitions, collaborations, expansions, a broad product portfolio, and the presence of a strong distribution and sales network across the globe have enabled this company to secure a leading position in the stable isotope labeled compounds market. (
  • Based on type, the stable isotope labeled compounds industry is segmented into C-13, N-15, O-18, H-2 (deuterium), and other isotopes. (
  • The H-2 labeled compounds segment accounted for the largest share of the stable isotope-labeled compounds market in 2019. (
  • Based on application, the stable isotope labeled compounds market is segmented into research, clinical diagnostics, industrial applications, and other applications. (
  • North America is expected to dominate the stable isotope labeled compounds market. (
  • Major growth drivers for the global stable isotope labeled compounds market include an increasing surge in research activities and growing trend in analytical research within the pharmaceutical and biotechnology sector. (
  • The rising incidence of cancer has notably boosted analytical investigations using stable isotope-labeled compounds. (
  • However, high cost of stable isotope labeled compounds and lack of skilled professionals are anticipated to restrain the overall market growth during the forecast period. (
  • These isotopes function as distinctive markers for compounds, detectable through techniques such as nuclear magnetic resonance (NMR) and mass spectrometry (MS). Commonly employed stable isotopes encompass 2H, 13C, and 15N. (
  • Researchers, particularly those engaged in metabolism-mediated toxicity studies, have shown significant interest in stable isotope-labeled compounds. (
  • Beyond metabolomics research, stable isotope-labeled compounds are experiencing increasing utilization in environmental analysis, proteomics, and medical diagnostic research. (
  • COVID-19 pandemic had a positive impact on the global stable isotope labeled compounds market. (
  • During the pandemic period, the global stable isotope labeled compounds market experienced noteworthy growth due to heightened demand for stable isotope-labeled compounds, driven by their crucial role in research related to the virus, such as investigations into the structure and dynamics of membrane proteins in pathogens like SARS-CoV-2. (
  • The lessons learned and the increased utilization of stable isotope-labeled compounds during the pandemic are likely to contribute to healthy market expansion during the forecast period. (
  • On the basis of end user, the global stable isotope labeled compounds market is divided into Academic & Research Institutions, Hospital & Diagnostic Centers, and Pharmaceutical & Biotechnology Companies segments. (
  • The pharmaceutical & biotechnology companies segment is expected to hold the highest share in the global stable isotope labeled compounds market by end user during the forecast period. (
  • Stable Isotope Labeling by/with Amino acids in Cell culture (SILAC) is a technique based on mass spectrometry that detects differences in protein abundance among samples using non-radioactive isotopic labeling. (
  • In contrast, the second population is fed with growth medium containing amino acids labeled with stable (non-radioactive) heavy isotopes. (
  • Pulsed SILAC (pSILAC) is a variation of the SILAC method where the labelled amino acids are added to the growth medium for only a short period of time. (
  • The NeuCode amino acid method is similar to SILAC but differs in that the labeling only utilizes heavy amino acids. (
  • The increased multiplexing capability of NeuCode amino acids is from the use of mass defects from extra neutrons in the stable isotopes. (
  • MedChemExpress ( MCE ) offers a diverse array of Stable Isotope-Labeled Amino Acids & Peptides, including free and protected amino acids. (
  • Applications of Stable Isotope-Labeled amino acids are directed to proteomic, metabolomics, or structural biology researches, etc . (
  • These include free and protected amino acids (for both canonical and non-canonical) as well as mixes and methyl labeling kits. (
  • However, efficient labeling of proteins with selected amino acids necessitates auxotrophic hosts, which are often not available. (
  • Below lists is the most common stable isotopically labeled amino acids that can be used for the synthesis of peptides with stable isotopes containing carbon 13 ( 13 C), Nitrogen 15 ( 15 N). (
  • 13C-labeled amino acids are analyzed using an Agilent 1290 Infinity II coupled to an ABSciex QTRAP 6500+ LC-MS/MS system. (
  • We recently developed a practical protocol for preparing proteins bearing stereo-selectively 13 C-methyl labeled leucines and valines, instead of the commonly used 13 C-methyl labeled precursors for these amino acids, by E. coli cellular expression. (
  • Cambridge Isotope Laboratories offers a complete listing of Stable Isotope Labeled Mass Spec for all your research needs. (
  • The CIL group comprises five companies-Cambridge Isotope Laboratories, Inc. (CIL) (US), CIL Isotope Separations, LLC (CIS) (US), CIL Canada (Canada), Euriso-Top (France), and ABX GmbH (Germany). (
  • Proteins from both cell populations are combined and analyzed together by mass spectrometry as pairs of chemically identical peptides of different stable-isotope composition can be differentiated in a mass spectrometer owing to their mass difference. (
  • Here, we describe a new method (immuno-SILAC) for the absolute quantification of proteins in complex samples based on polyclonal antibodies and stable isotope-labeled recombinant protein fragments to allow affinity enrichment prior to mass spectrometry analysis and accurate quantification. (
  • Nuclear magnetic resonance spectroscopy, Radiolabeling, Biomolecules-Analysis, Isotope Labeling-methods, Nuclear Magnetic Resonance, Biomolecular Here we describe a protocol for the labeling of proteins that facilitates their study using a technique that is sensitive to millisecond conformational exchange restrict to techniques of labeling with isotopes (stable or radioactive): do not use for radioisotope tracer studies of "labeled" cells, microorganisms or chemicals Pris: 1862 kr. (
  • 12. C. This gives a Amino-acid selective isotope labeling of proteins offers numerous advantages in mechanistic studies by revealing structural and functional information unattainable from a crystallographic approach. (
  • Stable isotope labeled peptides, or SIL peptides, maintain identical amino acid sequence with the natural ones released from the parent proteins by chemical or enzymatic cleavage, but some of the amino acid residuals are labeled by specific stable isotope, such as 2 H, 13 C, and/or 15 N atom(s). (
  • The SAIL labeling pattern is particularly useful for the structure calculation of large proteins with advantages seen in the NOESY spectra. (
  • Using this protocol, proteins with any combinations of isotope-labeled or unlabeled Leu and Val residues were prepared, including some that could not be prepared by the precursor methods. (
  • LP3 is colocalised with and closely collaborates with the DEMAX platform of the ESS on production of deuterium labeled biomolecules (proteins, lipids) for neutron scattering experiments and the development of methods for crystal growth for neutron crystallography. (
  • They compared the isotope patterns of these spectra to the spectra of the metabolites produced from unlabeled glucose and were able to identify herpetopanone, a diterpene with the formula C 20 H 36 O 4 . (
  • BDG Synthesis specialises in the custom synthesis of milligram to multi-gram quantities of precisely labelled stable isotope materials, metabolites and reference standards, for clients worldwide, including the US, UK, EU and Asia Pacific. (
  • For instance, isotope-assisted metabolomics technology has enabled the mapping of a global metabolic network, estimation of flux at branch points of metabolic pathways, and assignment of elemental formulas to unknown metabolites. (
  • The combination of high-resolution LC-MS-based untargeted metabolomics with stable isotope tracing provides a global overview of the cellular fate of precursor metabolites. (
  • This methodology enables detection of putative metabolites from biological samples and simultaneous quantification of the pattern and extent of isotope labeling. (
  • Labeling of Trypanosoma brucei cell cultures with 50% uniformly 13C-labeled glucose demonstrated incorporation of glucose-derived carbon into 187 of 588 putatively identified metabolites in diverse pathways including carbohydrate, nucleotide, lipid, and amino acid metabolism. (
  • Labeling patterns confirmed the metabolic pathways responsible for the biosynthesis of many detected metabolites, and labeling was detected in unexpected metabolites, including two higher sugar phosphates annotated as octulose phosphate and nonulose phosphate. (
  • Markus Nett, Technical University Dortmund, Germany, and colleagues have discovered a new natural product, herpetopanone (pictured), which is produced by Herpetosiphon aurantiacus 114-95 T . The team fed glucose, labeled with 13 C atoms, to a culture of the bacterium, and used liquid chromatography-mass spectrometry (LC-MS) to analyze the metabolic products of the bacteria. (
  • M. Takeda, M. Kainosho, in Comprehensive Isotope Labeling of Biomolecules - Labeling Methods. (
  • In our Silantes Webshop you can find stable isotope labelled ( 2 H, 13 C, 15 N) biomolecules as standards for NMR spectroscopy and as internal mass standards for mass spectrometry. (
  • Techniques for labeling a substance with a stable or radioactive isotope. (
  • Stable isotope labeled peptides have been widely applied in the nuclear magnetic resonance (NMR) spectroscopy and mass spectrometry (MS). The combination of SIL peptides with NMR spectroscopy allow for the incorporation of NMR active nuclei which can reduce the complexity of spectra, and then help researchers to obtain novel correlations between atoms for more structural information. (
  • Recent advances in metabolomics have extended the capability of isotope-assisted studies to reveal global metabolism. (
  • Here, we report a new chemical isotope labelling LC-MS analytical method for one-pot derivatization of CK bases and their glycoconjugates, based on differential benzylation labelling of the adenine skeleton of CKs with benzyl bromide and its deuterium isotope-labelled reagent. (
  • γ-Aminobutyric acid-d 6 is the deuterium labeled γ-Aminobutyric acid. (
  • L-Phenylalanine-d 5 is the deuterium labeled L-Phenylalanine. (
  • L-Leucine-d 3 is the deuterium labeled L-Leucine. (
  • L-Glutamic acid-d 5 is the deuterium labeled L-Glutamic acid. (
  • The kit includes matched, deuterium-labeled internal standards for a total of 44 solutions. (
  • Stable isotope labeling involves the utilization of non-radioactive isotopes as tracers for modeling various chemical and biochemical systems. (
  • In the first incident, a patient was inadvertently injected intravenously with an estimated 100-200 uL of fresh whole blood from an HIV-infected patient after a used syringe containing the blood was mistaken for another syringe containing red blood cells that had been treated (i.e., labeled) with a radioactive isotope (1). (
  • the cells had been labeled with a radioactive isotope and were injected in the wrong patient when hospital personnel failed to correctly match the identification number of the recipient with that of the specimen of white blood cells (2,3). (
  • A small subset of these procedures involves withdrawing and then reinjecting a patient's blood after certain cells or elements (i.e., red blood cells, white blood cells, or platelets) are labeled with a radioactive isotope. (
  • Fluorodeoxyglucose (FDG) labeled with the radioactive tracer isotope fluorine-18 ( 18 F) is concentrated in areas of increased glucose metabolism. (
  • For example, the medium can contain arginine labeled with six carbon-13 atoms (13C) instead of the normal carbon-12 (12C). (
  • A SILAC approach involving incorporation of tyrosine labeled with nine carbon-13 atoms (13C) instead of the normal carbon-12 (12C) has been utilized to study tyrosine kinase substrates in signaling pathways. (
  • This method uses isotope dilution with carbon-13 labeled internal standards. (
  • Ions from each analyte and each carbon-13 labeled internal standard are monitored, and the abundances of each ion are measured. (
  • Stable Isotope Products for Chemical Labeling Stable isotope coded chemical tags enable researchers to perform mass spectrometric- based proteomics studies in the absence of metabolic labeling. (
  • Stable isotope tracing's role in understanding nutraceuticals' impact on cancer metabolism, as well as proteomics research, contributed to market expansion. (
  • Köp boken Isotope labeling in Biomolecular NMR (ISBN 9789400749535) hos Adlibris. (
  • XAD-2 resin and polyurethane foam (PUF) matrices were extracted with acetonitrile containing stable-isotope labeled internal standards (ISTD). (
  • Recently, a new technique called NeuCode (neutron encoding) SILAC, has augmented the level of multiplexing achievable with metabolic labeling (up to 4). (
  • For obtaining metabolic and pharmaco kinetic data, a widely used method, often the method of choice, is that of radio labelling the compound to be studied. (
  • We have developed a new approach for monitoring the metabolic dynamics in microbial ecosystems using a combination of DNA fingerprinting and metabolome analysis based on stable-isotope-labeling technologies. (
  • L-Valine-d 8 can be used in the labelled synthesis of L-valineamide-d8 intermediate[1]. (
  • By capitalizing on our stable isotope labeled RNA phosphoramidites and triphosphates innotope offers an oligonucleotide synthesis service for our customers. (
  • 5' - & 3' - End labeling of nucleic acids, Sequencing of nucleic acids, Nucleic acid hybridization, Making of labelled hybridization probes, Gene cloning, Studies on mechanism of DNA repair and DNA replication, Transcription of genetic message to RNA, Translation of genetic information from RNA to protein. (
  • Stable isotope labeling of nucleic acids. (
  • Therefore, the isotope shifts would provide a useful auxiliary index for identifying Lys residues with deprotonated ζ -amino groups at physiological pH levels. (
  • Labeling occurs by site-specific incorporation of stable isotope labeled tags at cysteine residues or the general labeling of amines and carboxyl groups in protein samples. (
  • However, there is still room for improvement in the labeling efficiencies for Val residues, using the methods with labeled precursors or Val itself. (
  • Taking advantage of the double-deletion mutant, ΔilvDΔleuB E. coli BL21(DE3), an efficient and residue-selective labeling method with various isotope-labeled Ile, Leu, and Val residues was established. (
  • Tracers that may be labeled include chemical substances, cells, or microorganisms. (
  • With more than 10 years of experience, and as a world-leading peptide manufacturing organization, NovoPro can provide customized peptides labeled with stable isotopes including 2 H, 15 N & 13 C, respectively, or a combination of 15 N & 13 C. Even when the peptides are attached with specific modification motifs. (
  • The labelleding of methyl and methylene groups in SAIL-labelled samples also makes them amenable to straight forward relaxation experiments for the investigation of side-chain motions. (
  • Indeed, although there are fewer NOE peaks for a SAIL-labelled protein than for a uniformly 15 N, 13 C-labelled one, it is likely that there are more interpretable NOE peaks. (
  • It had also been used to study biofilm tolerance to antibiotics to differentiate tolerant and sensitive subpopulations Traditionally the level of multiplexing in SILAC was limited due to the number of SILAC isotopes available. (
  • Large-scale quantitative phosphoproteomic analysis (TMT-labeling) in the presence of the vasopressin analog dDAVP (0.1 nM, 30 min) allowed quantification of 11,570 phosphosites of which 169 were significantly decreased, while 206 were increased in abundance in CAMK2D knockout clones. (
  • The approach was further developed to also generate quantitative data via the addition of heavy isotope-labeled recombinant protein fragment standards prior to trypsin digestion. (
  • Chemical isotope labelling LC-MS analysis methods have been developed for most other phytohormones, enhancing their LC separations and quantitative sensitivity. (
  • These industries heavily rely on stable isotopes for drug discovery, development, and toxicity studies. (
  • Matrix effects were evaluated by spiking the samples with isotope-labeled standards of 40 polar contaminants. (
  • SAIL-labelled protein is prepared using cell-free methods . (
  • The SAIL Wiki site has a figure illustrating the labelling scheme. (
  • By reducing the number of these protons in SAIL-labelled samples, the overlap is decreased and the quality of NOESY spectra is improved. (
  • More general advantages of SAIL-labelled samples include the fact that lines become sharper due to a decrease in long-range couplings and by eliminating dipolar relaxation pathways. (
  • Despite the clear advantages to using SAIL-labelled protein for structure determination, this labelling method is not very common - probably because it is very expensive and requires cell-free technologoy which is not available in many labs. (
  • For the development and validation of our monitoring approach, fecal microbiota were analyzed with stable-isotope-labeled glucose used as the sole carbon source. (
  • We established an efficient approach, crosslinking of segmentally isotope-labeled RNA and tandem mass spectrometry (CLIR-MS/MS), to localize protein-RNA interactions simultaneously at amino acid and nucleotide resolution. (
  • In this work we demonstrate the potential of glycan reductive isotope labeling (GRIL) using [12C]- and [13C]-coded aniline and zwitterionic hydrophilic interaction capillary liquid chromatography electrospray mass spectrometry (μZIC-HILIC-ESI-MS) for relative quantitation of glycosylation variants in selected glycoproteins present in samples from cancer patients. (
  • After de-N-glycosylation, relative quantitation of the hAGP glycans was carried out using stable isotope labeling and μZIC-HILIC-ESI-MS analysis. (
  • Importantly, the results demonstrate that the presented methodology combining an enrichment of a target protein by IAC with isotope coded relative quantitation of N-glycans can be successfully used for targeted glycomics studies. (
  • IsoCor: correcting MS data in isotope labeling experiments. (
  • The method can be used for automated detection of chemical/post- translational modifications, quality control of experiments and labelling approaches, and to control the modification settings of protein identification tools. (
  • Four Isotope-Labeled Recombination Pathways of Ozone Formation" by Dmitri Babikov, Elizaveta Grushnikova et al. (
  • These pathways become physically distinct when a rare isotope of oxygen is introduced, such as 18 O, which represents a sensitive probe of the ozone forming reaction. (
  • Two pathways for the formation of asymmetric ozone isotopomer exhibit rather different rate coefficients, indicating large isotope effect driven by -difference. (
  • The company's isotope separation facility located in Ohio (US) is the world's largest C-13 and O-18 isotope separation facility and has the only commercial heavy enrichment columns in the world. (
  • The aromatic ring labeling strategy removes one-bond 13 C- 13 C couplings, which often complicate spectra or require the use of constant time data collection methods to reduce spectral complexity. (
  • Recent developments of improved NMR methods and isotope labeling schemes have enabled a number of advances in addressing the. (
  • It is not used for articles involving labeled substances unless the methods of labeling are substantively discussed. (
  • As one of the world's leading radio-labeling groups we have a reputation for excellence in synthetic chemistry enabling us to carry out the most challenging synthetic projects. (
  • 2010-04-07 This putative identification is corroborated by mass spectrometric fragmentation, isotope labeling, and a gene silencing experiment. (
  • Typically, these studies are performed with high-resolution isotope ratio mass spectrometers (IRMSs) along with a changeover-valve-based dual-inlet system (DIS). (
  • Due to technological advances clumped-isotope studies have gained importance in recent years. (
  • Isotope-labeling is a useful technique for understanding cellular metabolism. (
  • Using stable isotope labeling and siRNA-mediated gene silencing, we showed that A549 lung cancer cells produce NAA and its downstream … 2019-06-26 15 N-labeling. (
  • Alternatively, uniform labeling with 13C or 15N can be used. (
  • Uniform 15 N labeling results in an isolated spin 2018-06-12 Isotopic labeling is a technique for tracking the passage of a sample of substance through a system. (
  • Identification of specific genes like onco genes.Screening of population for infection by bacteria, fungus and virus using labelled probes. (
  • Amyloid β concentrations and stable isotope labeling kinetics of human plasma specific to central nervous system amyloidosis. (
  • We are taking a different approach, namely performing clumped-isotope measurements with a compact low-resolution IRMS with an open-split-based DIS. (
  • The 13 C / 15 N / 2 H-stable isotope labeled RNA phosphoramidites and triphosphates provided by innotope can be utilized to produce tailor made RNA oligonucleotides with the optimized isotope labeling pattern for follow up applications. (

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