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.
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.
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 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 nitrogen atoms that have the same atomic number as the element nitrogen, but differ in atomic weight. N-15 is a stable nitrogen isotope.
A colorless, odorless gas that can be formed by the body and is necessary for the respiration cycle of plants and animals.
A hydrocarbon used as an industrial solvent. It has been used as an aerosal propellent, as a refrigerant and as a local anesthetic. (From Martindale, The Extra Pharmacopoeia, 31st ed, p1403)
The gaseous envelope surrounding a planet or similar body. (From Random House Unabridged Dictionary, 2d ed)
Remains, impressions, or traces of animals or plants of past geological times which have been preserved in the earth's crust.
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)
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)
Toxic, chlorinated, saturated hydrocarbons. Include both the 1,1- and 1,2-dichloro isomers. The latter is considerably more toxic. It has a sweet taste, ethereal odor and has been used as a fumigant and intoxicant among sniffers. Has many household and industrial uses.
The study of early forms of life through fossil remains.
A genus of gram-negative, aerobic, rod-shaped bacteria found in wet soil containing decaying organic material and in water. Cells tend to be pleomorphic if grown on media containing succinate or coccoid if grown in the presence of an alcohol as the sole carbon source. (From Bergey's Manual of Determinative Bacteriology, 9th ed)
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)
A plant species of the genus PINUS which is the subject of genetic study.
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 family of bacteria found in the mouth and intestinal and respiratory tracts of man and other animals as well as in the human female urogenital tract. Its organisms are also found in soil and on cereal grains.
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)
Carbon monoxide (CO). A poisonous colorless, odorless, tasteless gas. It combines with hemoglobin to form carboxyhemoglobin, which has no oxygen carrying capacity. The resultant oxygen deprivation causes headache, dizziness, decreased pulse and respiratory rates, unconsciousness, and death. (From Merck Index, 11th ed)
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)
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)
The cycle by which the element carbon is exchanged between organic matter and the earth's physical environment.
Nanometer-sized tubes composed mainly of CARBON. Such nanotubes are used as probes for high-resolution structural and chemical imaging of biomolecules with ATOMIC FORCE MICROSCOPY.
Inorganic compounds that contain carbon as an integral part of the molecule but are not derived from hydrocarbons.
The 17-alpha isomer of TESTOSTERONE, derived from PREGNENOLONE via the delta5-steroid pathway, and via 5-androstene-3-beta,17-alpha-diol. Epitestosterone acts as an antiandrogen in various target tissues. The ratio between testosterone/epitestosterone is used to monitor anabolic drug abuse.
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)
A plant genus of the family ASTERACEAE that is used for experiments in molecular genetic studies in plant physiology and development.
A plant genus of the family RHAMNACEAE. Several species have been reclassified to the FRANGULA genus. It is often called buckthorn but should not be confused with other plants called that.
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)
Total mass of all the organisms of a given type and/or in a given area. (From Concise Dictionary of Biology, 1990) It includes the yield of vegetative mass produced from any given crop.
The period of history before 500 of the common era.
A plant genus of the family MYRTACEAE. Members contain PHYTOHEMAGGLUTININS.
A genus of rod-shaped, oval, or bean-shaped bacteria found in soil and fresh water. Polar prosthecae are present and cells reproduce by budding at the tips of the prosthecae. Cells of this genus are aerobic and grow best with one-carbon compounds. (From Bergey's Manual of Determinative Bacteriology, 9th ed)
Illegitimate use of substances for a desired effect in competitive sports. It includes humans and animals.
The salinated water of OCEANS AND SEAS that provides habitat for marine organisms.
Elimination of ENVIRONMENTAL POLLUTANTS; PESTICIDES and other waste using living organisms, usually involving intervention of environmental or sanitation engineers.
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.
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).
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)
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.
A microanalytical technique combining mass spectrometry and gas chromatography for the qualitative as well as quantitative determinations of compounds.
Closable openings in the epidermis of plants on the underside of leaves. They allow the exchange of gases between the internal tissues of the plant and the outside atmosphere.
An enzyme with high affinity for carbon dioxide. It catalyzes irreversibly the formation of oxaloacetate from phosphoenolpyruvate and carbon dioxide. This fixation of carbon dioxide in several bacteria and some plants is the first step in the biosynthesis of glucose. EC 4.1.1.31.
The unconsolidated mineral or organic matter on the surface of the earth that serves as a natural medium for the growth of land plants.
Water particles that fall from the ATMOSPHERE.
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.
The ceasing of existence of a species or taxonomic groups of organisms.
Water containing no significant amounts of salts, such as water from RIVERS and LAKES.
A carboxy-lyase that plays a key role in photosynthetic carbon assimilation in the CALVIN-BENSON CYCLE by catalyzing the formation of 3-phosphoglycerate from ribulose 1,5-biphosphate and CARBON DIOXIDE. It can also utilize OXYGEN as a substrate to catalyze the synthesis of 2-phosphoglycolate and 3-phosphoglycerate in a process referred to as photorespiration.
Toxic asphyxiation due to the displacement of oxygen from oxyhemoglobin by carbon monoxide.
Deuterium. The stable isotope of hydrogen. It has one neutron and one proton in the nucleus.
A large family of narrow-leaved herbaceous grasses of the order Cyperales, subclass Commelinidae, class Liliopsida (monocotyledons). Food grains (EDIBLE GRAIN) come from members of this family. RHINITIS, ALLERGIC, SEASONAL can be induced by POLLEN of many of the grasses.
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)
Woody, usually tall, perennial higher plants (Angiosperms, Gymnosperms, and some Pterophyta) having usually a main stem and numerous branches.
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.
Order of mammals whose members are adapted for flight. It includes bats, flying foxes, and fruit bats.
The longterm manifestations of WEATHER. (McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)
Derivatives of ACETIC ACID. Included under this heading are a broad variety of acid forms, salts, esters, and amides that contain the carboxymethane structure.
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.
Inorganic salts of sulfuric acid.
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)
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.
A solvent for oils, fats, lacquers, varnishes, rubber waxes, and resins, and a starting material in the manufacturing of organic compounds. Poisoning by inhalation, ingestion or skin absorption is possible and may be fatal. (Merck Index, 11th ed)
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.
The complete absence, or (loosely) the paucity, of gaseous or dissolved elemental oxygen in a given place or environment. (From Singleton & Sainsbury, Dictionary of Microbiology and Molecular Biology, 2d ed)
Any of several processes for the permanent or long-term artificial or natural capture or removal and storage of carbon dioxide and other forms of carbon, through biological, chemical or physical processes, in a manner that prevents it from being released into the atmosphere.
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)
A colorless, flammable, poisonous liquid, CS2. It is used as a solvent, and is a counterirritant and has local anesthetic properties but is not used as such. It is highly toxic with pronounced CNS, hematologic, and dermatologic effects.
Divisions of the year according to some regularly recurrent phenomena usually astronomical or climatic. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)
Regular course of eating and drinking adopted by a person or animal.
Unstable isotopes of carbon that decay or disintegrate emitting radiation. C atoms with atomic weights 10, 11, and 14-16 are radioactive carbon isotopes.
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.
An analytical method used in determining the identity of a chemical based on its mass using mass analyzers/mass spectrometers.
The process of cumulative change over successive generations through which organisms acquire their distinguishing morphological and physiological characteristics.
The relationships of groups of organisms as reflected by their genetic makeup.
Carbon tetrachloride poisoning is a condition characterized by the systemic toxicity induced by exposure to carbon tetrachloride, a volatile chlorinated hydrocarbon solvent, causing central nervous system depression, cardiovascular collapse, and potentially fatal liver and kidney damage.
The rate dynamics in chemical or physical systems.
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)
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.
A measure of the total greenhouse gas emissions produced by an individual, organization, event, or product. It is measured in units of equivalent kilograms of CARBON DIOXIDE generated in a given time frame.
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).
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.
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.
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)
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.
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)
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)
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).
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.
The inanimate matter of Earth, the structures and properties of this matter, and the processes that affect it.
A dark powdery deposit of unburned fuel residues, composed mainly of amorphous CARBON and some HYDROCARBONS, that accumulates in chimneys, automobile mufflers and other surfaces exposed to smoke. It is the product of incomplete combustion of carbon-rich organic fuels in low oxygen conditions. It is sometimes called lampblack or carbon black and is used in INK, in rubber tires, and to prepare CARBON NANOTUBES.
Carboxyhemoglobin is a form of hemoglobin in which the heme group is chemically bonded to carbon monoxide, reducing its ability to transport oxygen and leading to toxic effects when present in high concentrations.
The facilitation of a chemical reaction by material (catalyst) that is not consumed by the reaction.
Chromatographic techniques in which the mobile phase is a liquid.

An examination of coaxial stacking of helical stems in a pseudoknot motif: the gene 32 messenger RNA pseudoknot of bacteriophage T2. (1/7271)

The RNA pseudoknot located at the 5' end of the gene 32 messenger RNA of bacteriophage T2 contains two A-form helical stems connected by two loops, in an H-type pseudoknot topology. A combination of multidimensional NMR methods and isotope labeling were used to investigate the pseudoknot structure, resulting in a more detailed structural model than provided by earlier homonuclear NMR studies. Of particular significance, the interface between the stacked helical stems within the pseudoknot motif is described in detail. The two stems are stacked in a coaxial manner, with an approximately 18 degrees rotation of stem1 relative to stem2 about an axis that is parallel to the helical axis. This rotation serves to relieve what would otherwise be a relatively close phosphate-phosphate contact at the junction of the two stems, while preserving the stabilizing effects of base stacking. The ability of the NMR data to determine pseudoknot bending was critically assessed. The data were found to be a modestly precise indicator of pseudoknot bending, with the angle between the helical axes of stem1 and stem2 being in the range of 15+/-15 degrees. Pseudoknot models with bend angles within this range are equally consistent with the data, since they differ by only small amounts in the relatively short-range interproton distances from which the structure was derived. The gene 32 messenger RNA pseudoknot was compared with other RNA structures with coaxial or near-coaxial stacked helical stems.  (+info)

Prior protein intake may affect phenylalanine kinetics measured in healthy adult volunteers consuming 1 g protein. kg-1. d-1. (2/7271)

Study of the amino acid metabolism of vulnerable groups, such as pregnant women, children and patients, is needed. Our existing protocol is preceded by 2 d of adaptation to a low 13C formula diet at a protein intake of 1 g. kg-1. d-1 to minimize variations in breath 13CO2 enrichment and protein metabolism. To expand on our potential study populations, a less invasive protocol needs to be developed. We have already established that a stable background 13CO2 enrichment can be achieved on the study day without prior adaptation to the low 13C formula. Therefore, this study investigates phenylalanine kinetics in response to variations in prior protein intake. Healthy adult subjects were each fed nutritionally adequate mixed diets containing 0.8, 1.4 and 2.0 g protein. kg-1. d-1 for 2 d. On d 3, subjects consumed an amino acid-based formula diet containing the equivalent of 1 g protein. kg-1. d-1 hourly for 10 h and primed hourly oral doses of L-[1-13C]phenylalanine for the final 6 h. Phenylalanine kinetics were calculated from plasma-free phenylalanine enrichment and breath 13CO2 excretion. A significant quadratic response of prior protein intake on phenylalanine flux (P = 0.012) and oxidation (P = 0.009) was identified, such that both variables were lower following adaptation to a protein intake of 1.4 g. kg-1. d-1. We conclude that variations in protein intake, between 0.8 and 2.0 g. kg-1. d-1, prior to the study day may affect amino acid kinetics and; therefore, it is prudent to continue to control protein intake prior to an amino acid kinetics study.  (+info)

Carbon 13 NMR study of nonenzymatic reactions of pyridoxal 5'-phosphate with selected amino acids and of related reactions. (3/7271)

Carbon 13 nuclear magnetic resonance spectroscopy has been used to monitor the nonenzymatic reactions of pyridoxal 5'-phosphate with glycine, alanine, valine, serine, and with several other model compounds. Isotopically enriched amino acids were employed so that low concentrations could be utilized while still allowing relatively rapid acquisition of spectral data. The results for alanine and serine are particularly noteworthy in that alanine is deaminated to pyruvate and pyruvate is aminated to alanine, but contrary to the enzymatic reactions of various serine dehydratases wherein serine is converted to pyruvate, the nonenzymatic reaction utilizing serine results in hydroxypruvate rather than pyruvate formation. In the reverse reaction, hydroxypyruvate is aminated to serine but very inefficiently relative to the amination of pyruvate to alanine. The experimental results have been formulated into a proposed reaction mechanism for deamination of amino acids by pyridoxal-P.  (+info)

The Ice Man's diet as reflected by the stable nitrogen and carbon isotopic composition of his hair. (4/7271)

Establishing the diets of ancient human populations is an integral component of most archaeological studies. Stable isotope analysis of well-preserved bone collagen is the most direct approach for a general assessment of paleodiet. However, this method has been limited by the scarcity of well-preserved skeletal materials for this type of destructive analysis. Hair is preserved in many burials, but is often overlooked as an alternative material for isotopic analysis. Here we report that the stable carbon and nitrogen isotope values for the hair of the 5200 year-old Ice Man indicates a primarily vegetarian diet, in agreement with his dental wear pattern. Whereas previous investigations have focused on bone collagen, the stable isotope composition of hair may prove to be a more reliable proxy for paleodiet reconstruction, particularly when skeletal remains are not well preserved and additional archaeological artifacts are unavailable.  (+info)

European interlaboratory comparison of breath 13CO2 analysis. (5/7271)

The BIOMED I programme Stable Isotopes in Gastroenterology and Nutrition (SIGN) has focused upon evaluation and standardisation of stable isotope breath tests using 13C labelled substrates. The programme dealt with comparison of 13C substrates, test meals, test conditions, analysis techniques, and calculation procedures. Analytical techniques applied for 13CO2 analysis were evaluated by taking an inventory of instrumentation, calibration protocols, and analysis procedures. Two ring tests were initiated measuring 13C abundances of carbonate materials. Evaluating the data it was found that seven different models of isotope ratio mass spectrometers (IRMS) were used by the participants applying both the dual inlet system and the continuous flow configuration. Eight different brands of certified 13C reference materials were used with a 13C abundance varying from delta 13CPDB -37.2 to +2.0/1000. CO2 was liberated from certified material by three techniques and different working standards were used varying from -47.4 to +0.4/1000 in their delta 13CPDB value. The standard deviations (SDs) found for all measurements by all participants were 0.25/1000 and 0.50/1000 for two carbonates used in the ring tests. The individual variation for the single participants varied from 0.02 /1000 (dual inlet system) to 0.14/1000 (continuous flow system). The measurement of the difference between two carbonates showed a SD of 0.33/1000 calculated for all participants. Internal precision of IRMS as indicated by the specifications of the different instrument suppliers is < 0.3/1000 for continuous flow systems. In this respect it can be concluded that all participants are working well within the instrument specifications even including sample preparation. Increased overall interlaboratory variation is therefore likely to be due to non-instrumental conditions. It is possible that consistent differences in sample handling leading to isotope fractionation are the causes for interlaboratory variation. Breath analysis does not require sample preparation. As such, interlaboratory variation will be less than observed for the carbonate samples and within the range indicated as internal precision for continuous flow instruments. From this it is concluded that pure analytical interlaboratory variation is acceptable despite the many differences in instrumentation and analytical protocols. Coordinated metabolic studies appear possible, in which different European laboratories perform 13CO2 analysis. Evaluation of compatibility of the analytical systems remains advisable, however.  (+info)

Enzymatic synthesis of natural and 13C enriched linear poly-N-acetyllactosamines as ligands for galectin-1. (6/7271)

As part of a study of protein-carbohydrate interactions, linear N-acetyl-polyllactosamines [Galbeta1,4GlcNAcbeta1,3]nwere synthesized at the 10-100 micromol scale using enzymatic methods. The methods described also provided specifically [1-13C]-galactose-labeled tetra- and hexasaccharides ([1-13C]-Galbeta1,4GlcNAcbeta1,3Galbeta1,4Glc and Galbeta1, 4GlcNAcbeta1,3[1-13C]Galbeta1,4GlcNAcbeta1,3Galbeta 1,4Glc) suitable for NMR studies. Two series of oligosaccharides were produced, with either glucose or N-acetlyglucosamine at the reducing end. In both cases, large amounts of starting primer were available from human milk oligosaccharides (trisaccharide primer GlcNAcbeta1,3Galbeta1, 4Glc) or via transglycosylation from N-acetyllactosamine. Partially purified and immobilized glycosyltransferases, such as bovine milk beta1,4 galactosyltransferase and human serum beta1,3 N- acetylglucosaminyltransferase, were used for the synthesis. All the oligo-saccharide products were characterized by1H and13C NMR spectroscopy and MALDI-TOF mass spectrometry. The target molecules were then used to study their interactions with recombinant galectin-1, and initial1H NMR spectroscopic results are presented to illustrate this approach. These results indicate that, for oligomers containing up to eight sugars, the principal interaction of the binding site of galectin-1 is with the terminal N-acetyllactosamine residues.  (+info)

Documenting the diet in ancient human populations through stable isotope analysis of hair. (7/7271)

Fundamental to the understanding of human history is the ability to make interpretations based on artefacts and other remains which are used to gather information about an ancient population. Sequestered in the organic matrices of these remains can be information, for example, concerning incidence of disease, genetic defects and diet. Stable isotopic compositions, especially those made on isolates of collagen from bones, have been used to help suggest principal dietary components. A significant problem in the use of collagen is its long-term stability, and the possibility of isotopic alteration during early diagenesis, or through contaminating condensation reactions. In this study, we suggest that a commonly overlooked material, human hair, may represent an ideal material to be used in addressing human diets of ancient civilizations. Through the analysis of the amino-acid composition of modern hair, as well as samples that were subjected to radiation (thus simulating ageing of the hair) and hair from humans that is up to 5200 years old, we have observed little in the way of chemical change. The principal amino acids observed in all of these samples are essentially identical in relative abundances and content. Dominating the compositions are serine, glutamic acid, threonine, glycine and leucine, respectively accounting for approximately 15%, 17%, 10%, 8% and 8% of the total hydrolysable amino acids. Even minor components (for example, alanine, valine, isoleucine) show similar constancy between the samples of different ages. This constancy clearly indicates minimal alteration of the amino-acid composition of the hair. Further, it would indicate that hair is well preserved and is amenable to isotopic analysis as a tool for distinguishing sources of nutrition. Based on this observation, we have isotopically characterized modern individuals for whom the diet has been documented. Both stable nitrogen and carbon isotope compositions were assessed, and together provide an indication of trophic status, and principal type (C3 or C4) of vegetation consumed. True vegans have nitrogen isotope compositions of about 7/1000 whereas humans consuming larger amounts of meat, eggs, or milk are more enriched in the heavy nitrogen isotope. We have also analysed large cross-sections of modern humans from North America and Europe to provide an indication of the variability seen in a population (the supermarket diet). There is a wide diversity in both carbon and nitrogen isotope values based at least partially on the levels of seafood, corn-fed beef and grains in the diets. Following analysis of the ancient hair, we have observed similar trends in certain ancient populations. For example, the Coptics of Egypt (1000 BP) and Chinchorro of Chile (5000-800 BP) have diets of similar diversity to those observed in the modern group but were isotopically influenced by local nutritional sources. In other ancient hair (Egyptian Late Middle Kingdom mummies, ca. 4000 BP), we have observed a much more uniform isotopic signature, indicating a more constant diet. We have also recognized a primary vegetarian component in the diet of the Neolithic Ice Man of the Oetztaler Alps (5200 BP). In certain cases, it appears that sulphur isotopes may help to further constrain dietary interpretations, owing to the good preservation and sulphur content of hair. It appears that analysis of the often-overlooked hair in archaeological sites may represent a significant new approach for understanding ancient human communities.  (+info)

NMR studies on the 46-kDa dimeric protein, 3,4-dihydroxy-2-butanone 4-phosphate synthase, using 2H, 13C, and 15N-labelling. (8/7271)

3,4-Dihydroxy-2-butanone 4-phosphate synthase catalyses the release of C-4 from the substrate, ribulose phosphate, via a complex series of rearrangement reactions. The cognate ribB gene of Escherichia coli was hyperexpressed in a recombinant E. coli strain. The protein was shown to be a 46-kDa homodimer by hydrodynamic analysis. A variety of protein samples labelled with different grades of 13C, 15N and 2H, i.e. one with 100% 2H and 15N, one with 75% 2H, 99% 13C, 15N, and one with 100% 2H, 99% 13C,15N were prepared. Despite the large molecular size, 2- and 3-dimensional NMR spectra of reasonable quality were obtained. Attempts at the assignment of individual 13C, 15N and 1H signals show, in principle, the feasibility of structure determination. The number of NMR signals shows unequivocally that the homodimeric protein obeys strict C2 symmetry.  (+info)

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.

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.

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.

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.

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.

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.

Methyl chloride, also known as methyl chloride or chloromethane, is not typically considered a medical term. However, it is a chemical compound with the formula CH3Cl. It is a colorless and extremely volatile liquid that easily evaporates at room temperature.

In terms of potential health impacts, methyl chloride can be harmful if inhaled, swallowed, or comes into contact with the skin. Exposure to high levels can cause symptoms such as headache, dizziness, irritation of the eyes, nose, and throat, nausea, vomiting, and difficulty breathing. Prolonged exposure or significant inhalation can lead to more severe health effects, including damage to the nervous system, liver, and kidneys.

It is essential to handle methyl chloride with care, following appropriate safety measures and guidelines, to minimize potential health risks.

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.

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.

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.

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.

Ethylene dichloride, also known as 1,2-dichloroethane, is an organic compound with the formula ClCH2CH2Cl. It is a colorless liquid with a chloroform-like odor. Ethylene dichloride is used in the production of vinyl chloride, which is used to make polyvinyl chloride (PVC) plastic.

Ethylene dichloride is also an intermediate in the production of other chemicals and is used as a solvent for various industrial applications. It is highly toxic and exposure can cause a range of adverse health effects, including irritation of the eyes, skin, and respiratory tract, nausea, vomiting, dizziness, and potentially more serious issues such as liver and kidney damage. Long-term exposure has been linked to an increased risk of certain types of cancer.

It is important to handle ethylene dichloride with care and to use appropriate personal protective equipment when working with this chemical. It should be stored in a cool, well-ventilated area away from heat sources and open flames.

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.

I apologize for the confusion, but "Xanthobacter" is not a medical term or concept. It is actually a genus name in the family of bacteria known as Xanthobacteraceae. These are aerobic, gram-negative bacteria that can be found in various environments such as soil and water. They have the ability to fix nitrogen and degrade certain organic compounds, making them important members of soil microbial communities. If you have any questions related to medical terminology or concepts, I would be happy to help.

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!

"Pinus taeda," also known as Loblolly Pine, is not a medical term. It is a species of tree in the family Pinaceae that is native to the southeastern United States. The tree is commonly used in the production of timber, paper, and pulp, and it has some medicinal uses as well.

The bark, leaves (needles), and sap of the Loblolly Pine have been used traditionally by indigenous peoples for various medicinal purposes, such as treating skin conditions, wounds, and respiratory ailments. However, there is limited scientific evidence to support these uses, and they should not be attempted without consulting a healthcare professional.

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.

Peptococcaceae is a family of obligately anaerobic, non-spore forming, gram-positive cocci that are found as normal flora in the human gastrointestinal tract. These bacteria are commonly isolated from feces and are known to be associated with various human infections, particularly intra-abdominal abscesses, bacteremia, and brain abscesses. The genus Peptococcus includes several species, such as Peptococcus niger and Peptococcus saccharolyticus, which are known to be associated with human infections. However, it is important to note that the taxonomy of this group of bacteria has undergone significant revisions in recent years, and some species previously classified as Peptococcaceae have been reassigned to other families.

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.

Carbon monoxide (CO) is a colorless, odorless, and tasteless gas that is slightly less dense than air. It is toxic to hemoglobic animals when encountered in concentrations above about 35 ppm. This compound is a product of incomplete combustion of organic matter, and is a major component of automobile exhaust.

Carbon monoxide is poisonous because it binds to hemoglobin in red blood cells much more strongly than oxygen does, forming carboxyhemoglobin. This prevents the transport of oxygen throughout the body, which can lead to suffocation and death. Symptoms of carbon monoxide poisoning include headache, dizziness, weakness, nausea, vomiting, confusion, and disorientation. Prolonged exposure can lead to unconsciousness and death.

Carbon monoxide detectors are commonly used in homes and other buildings to alert occupants to the presence of this dangerous gas. It is important to ensure that these devices are functioning properly and that they are placed in appropriate locations throughout the building. Additionally, it is essential to maintain appliances and heating systems to prevent the release of carbon monoxide into living spaces.

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.

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.

The carbon cycle is a biogeochemical cycle that describes the movement of carbon atoms between the Earth's land, atmosphere, and oceans. It involves the exchange of carbon between various reservoirs, including the biosphere (living organisms), pedosphere (soil), lithosphere (rocks and minerals), hydrosphere (water), and atmosphere.

The carbon cycle is essential for the regulation of Earth's climate and the functioning of ecosystems. Carbon moves between these reservoirs through various processes, including photosynthesis, respiration, decomposition, combustion, and weathering. Plants absorb carbon dioxide from the atmosphere during photosynthesis and convert it into organic matter, releasing oxygen as a byproduct. When plants and animals die, they decompose, releasing the stored carbon back into the atmosphere or soil.

Human activities, such as burning fossil fuels and deforestation, have significantly altered the natural carbon cycle, leading to an increase in atmospheric carbon dioxide concentrations and contributing to global climate change. Therefore, understanding the carbon cycle and its processes is crucial for developing strategies to mitigate the impacts of climate change and promote sustainable development.

Carbon nanotubes (CNTs) are defined in medical literature as hollow, cylindrical structures composed of rolled graphene sheets, with diameters typically measuring on the nanoscale (ranging from 1 to several tens of nanometers) and lengths that can reach several micrometers. They can be single-walled (SWCNTs), consisting of a single layer of graphene, or multi-walled (MWCNTs), composed of multiple concentric layers of graphene.

Carbon nanotubes have unique mechanical, electrical, and thermal properties that make them promising for various biomedical applications, such as drug delivery systems, biosensors, and tissue engineering scaffolds. However, their potential toxicity and long-term effects on human health are still under investigation, particularly concerning their ability to induce oxidative stress, inflammation, and genotoxicity in certain experimental settings.

Carbon inorganic compounds are chemical substances that contain carbon combined with one or more elements other than hydrogen. These compounds include oxides of carbon such as carbon monoxide (CO) and carbon dioxide (CO2), metal carbides like calcium carbide (CaC2) and silicon carbide (SiC), and carbonates like calcium carbonate (CaCO3) and sodium carbonate (Na2CO3).

Unlike organic compounds, which are based on carbon-hydrogen bonds, inorganic carbon compounds do not contain hydrocarbon structures. Instead, they feature carbon bonded to elements such as nitrogen, oxygen, sulfur, or halogens. Inorganic carbon compounds have diverse physical and chemical properties and play important roles in various industrial applications, as well as in biological systems.

Epitestosterone is a steroid hormone that is structurally similar to testosterone. It is produced in the body, primarily in the testes and adrenal glands, and is a natural component of human urine. Epitestosterone is a weak androgen, meaning it has minimal male sex hormone effects.

The ratio of epitestosterone to testosterone (T/E ratio) in urine is often used as a marker for the detection of doping with anabolic steroids, which are synthetic versions of testosterone. In athletes who have not taken performance-enhancing drugs, the T/E ratio is typically less than 1. However, when anabolic steroids are used, the level of testosterone in the body increases, while the level of epitestosterone remains relatively unchanged, leading to a higher T/E ratio.

Medical professionals and anti-doping agencies use a specific cutoff value for the T/E ratio to determine if an individual has violated doping regulations. It's important to note that some individuals may have naturally higher T/E ratios due to genetic factors, which can complicate the interpretation of test results in anti-doping tests.

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.

"Flaveria" is not a term that has a medical definition. It is a genus of flowering plants in the aster family (Asteraceae) that includes about 40 species, mostly native to the Americas. Some Flaveria species are used in research to study the molecular mechanisms of photosynthesis and plant responses to environmental stresses.

"Rhamnus" is a genus of plants, and it does not have a medical definition. It belongs to the buckthorn family (Rhamnaceae) and includes several species of shrubs and small trees that are found in various parts of the world, including Europe, Asia, and North America.

Some Rhamnus species have been used in traditional medicine for their laxative properties due to the presence of anthraquinones in their bark and leaves. However, it is important to note that the use of these plants as medicine should be done under the guidance of a healthcare professional, as they can cause adverse effects if not used properly.

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.

Biomass is defined in the medical field as a renewable energy source derived from organic materials, primarily plant matter, that can be burned or converted into fuel. This includes materials such as wood, agricultural waste, and even methane gas produced by landfills. Biomass is often used as a source of heat, electricity, or transportation fuels, and its use can help reduce greenhouse gas emissions and dependence on fossil fuels.

In the context of human health, biomass burning can have both positive and negative impacts. On one hand, biomass can provide a source of heat and energy for cooking and heating, which can improve living standards and reduce exposure to harmful pollutants from traditional cooking methods such as open fires. On the other hand, biomass burning can also produce air pollution, including particulate matter and toxic chemicals, that can have negative effects on respiratory health and contribute to climate change.

Therefore, while biomass has the potential to be a sustainable and low-carbon source of energy, it is important to consider the potential health and environmental impacts of its use and implement appropriate measures to minimize any negative effects.

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.

"Myrtus" is a botanical name that refers to a genus of evergreen shrubs and trees in the family Myrtaceae. The most common species is Myrtus communis, also known as the common myrtle or European myrtle. It is native to the Mediterranean region and has been used in traditional medicine for various purposes.

In a medical context, "Myrtus" may be mentioned in relation to herbal remedies or phytotherapy, where extracts from the leaves, flowers, or fruits of the plant are used. Some studies suggest that Myrtus communis may have anti-inflammatory, antimicrobial, and antioxidant properties. However, more research is needed to confirm these effects and establish safe and effective therapeutic dosages.

It's important to note that while some natural substances can be beneficial for health, they should not be used as a substitute for professional medical advice or treatment. Always consult with a healthcare provider before starting any new supplement regimen.

I'm sorry for any confusion, but "Hyphomicrobium" is not a medical term. It is a genus name in the bacterial kingdom, specifically within the class Betaproteobacteria. These are typically aerobic, motile bacteria that are often found in soil and water environments. They play a role in various biogeochemical processes such as denitrification and carbon cycling. If you have any questions related to biological or environmental sciences, I'd be happy to help with those!

Doping in sports is the use of prohibited substances or methods to improve athletic performance. The World Anti-Doping Agency (WADA) defines doping as "the occurrence of one or more of the following anti-doping rule violations":

1. Presence of a prohibited substance in an athlete's sample
2. Use or attempted use of a prohibited substance or method
3. Evading, refusing, or failing to submit to sample collection
4. Whereabouts failures (three missed tests or filing failures within a 12-month period)
5. Tampering or attempted tampering with any part of the doping control process
6. Possession, trafficking, or administration of a prohibited substance or method
7. Complicity in an anti-doping rule violation
8. Prohibited association with a person who has been serving a period of ineligibility for an anti-doping rule violation

Doping is considered unethical and harmful to the integrity of sports, as it provides an unfair advantage to those who engage in it. It can also have serious health consequences for athletes. Various international and national organizations, including WADA and the United States Anti-Doping Agency (USADA), work to prevent doping in sports through education, testing, and enforcement of anti-doping rules.

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.

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.

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.

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!

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.

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.

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.

Stomata are microscopic pores found in the epidermis of plant leaves, stems, and other organs. They are essential for gas exchange between the plant and the atmosphere, allowing the uptake of carbon dioxide for photosynthesis and the release of oxygen. Plant stomata consist of two guard cells that surround and regulate the size of the pore. The opening and closing of the stomatal pore are influenced by environmental factors such as light, humidity, and temperature, as well as internal signals within the plant.

Phosphoenolpyruvate carboxylase (PEP-carboxylase or PEPC) is a biotin-dependent enzyme that plays a crucial role in the carbon fixation process of photosynthesis, specifically in the C4 and CAM (Crassulacean Acid Metabolism) plant pathways. It is also found in some bacteria and archaea.

PEP-carboxylase catalyzes the irreversible reaction between phosphoenolpyruvate (PEP) and bicarbonate (HCO3-) to form oxaloacetate and inorganic phosphate (Pi). This reaction helps to initiate the carbon fixation process by incorporating atmospheric carbon dioxide into an organic molecule, which can then be used for various metabolic processes.

In C4 plants, PEP-carboxylase is primarily located in the mesophyll cells where it facilitates the initial fixation of CO2 onto PEP, forming oxaloacetate. This oxaloacetate is then reduced to malate, which is subsequently transported to bundle sheath cells for further metabolism and additional carbon fixation by another enzyme, ribulose-1,5-bisphosphate carboxylase/oxygenase (RuBisCO).

In CAM plants, PEP-carboxylase operates at night to fix CO2 into malate, which is stored in vacuoles. During the day, malate is decarboxylated, releasing CO2 for RuBisCO-mediated carbon fixation while conserving water through reduced stomatal opening.

PEP-carboxylase is also found in some non-photosynthetic bacteria and archaea, where it contributes to various metabolic pathways such as gluconeogenesis, anaplerotic reactions, and the glyoxylate cycle.

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 "rain" is not a medical term. In general, rain refers to water droplets that fall from the sky as part of the Earth's weather cycle. These drops form when moisture in the air condenses and cools, creating clouds which eventually become heavy enough to release the collected water.

If you have any medical concerns or questions, I'd be happy to try and help answer those for you!

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.

"Extinction, Biological" refers to the state or process of a species or taxonomic group becoming extinct, meaning that there are no surviving members remaining alive anywhere in the world. This can occur due to various factors such as environmental changes, competition with other species, overexploitation by humans, or a combination of these and other elements. It is an important concept in the field of biology and conservation, as the extinction of a species can have significant impacts on ecosystems and biodiversity.

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.

Ribulose-1,5-bisphosphate carboxylase/oxygenase (RuBisCO) is a crucial enzyme in the Calvin cycle, which is a process that plants use to convert carbon dioxide into glucose during photosynthesis. RuBisCO catalyzes the reaction between ribulose-1,5-bisphosphate and carbon dioxide, resulting in the formation of two molecules of 3-phosphoglycerate, which can then be converted into glucose.

RuBisCO is considered to be the most abundant enzyme on Earth, making up as much as 50% of the soluble protein found in leaves. It is a large and complex enzyme, consisting of eight small subunits and eight large subunits that are arranged in a barrel-shaped structure. The active site of the enzyme, where the reaction between ribulose-1,5-bisphosphate and carbon dioxide takes place, is located at the interface between two large subunits.

RuBisCO also has a secondary function as an oxygenase, which can lead to the production of glycolate, a toxic compound for plants. This reaction occurs when the enzyme binds with oxygen instead of carbon dioxide and is more prevalent in environments with low carbon dioxide concentrations and high oxygen concentrations. The glycolate produced during this process needs to be recycled through a series of reactions known as photorespiration, which can result in significant energy loss for the plant.

Carbon monoxide (CO) poisoning is a medical condition that occurs when carbon monoxide gas is inhaled, leading to the accumulation of this toxic gas in the bloodstream. Carbon monoxide is a colorless, odorless, and tasteless gas produced by the incomplete combustion of fossil fuels such as natural gas, propane, oil, wood, or coal.

When carbon monoxide is inhaled, it binds to hemoglobin, the protein in red blood cells responsible for carrying oxygen throughout the body. This binding forms carboxyhemoglobin (COHb), which reduces the oxygen-carrying capacity of the blood and leads to hypoxia, or insufficient oxygen supply to the body's tissues and organs.

The symptoms of carbon monoxide poisoning can vary depending on the level of exposure and the duration of exposure. Mild to moderate CO poisoning may cause symptoms such as headache, dizziness, weakness, nausea, vomiting, chest pain, and confusion. Severe CO poisoning can lead to loss of consciousness, seizures, heart failure, respiratory failure, and even death.

Carbon monoxide poisoning is a medical emergency that requires immediate treatment. Treatment typically involves administering high-flow oxygen therapy to help eliminate carbon monoxide from the body and prevent further damage to tissues and organs. In some cases, hyperbaric oxygen therapy may be used to accelerate the elimination of CO from the body.

Prevention is key in avoiding carbon monoxide poisoning. It is essential to ensure that all fuel-burning appliances are properly maintained and ventilated, and that carbon monoxide detectors are installed and functioning correctly in homes and other enclosed spaces.

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.

Poaceae is not a medical term but a taxonomic category, specifically the family name for grasses. In a broader sense, you might be asking for a medical context where knowledge of this plant family could be relevant. For instance, certain members of the Poaceae family can cause allergies or negative reactions in some people.

In a medical definition, Poaceae would be defined as:

The family of monocotyledonous plants that includes grasses, bamboo, and sedges. These plants are characterized by narrow leaves with parallel veins, jointed stems (called "nodes" and "internodes"), and flowers arranged in spikelets. Some members of this family are important food sources for humans and animals, such as rice, wheat, corn, barley, oats, and sorghum. Other members can cause negative reactions, like skin irritation or allergies, due to their silica-based defense structures called phytoliths.

"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.

I'm sorry for any confusion, but "trees" is not a medical term. It is a common term used in various fields, including biology, ecology, and dendrology, to refer to a woody perennial plant with a single stem or trunk that supports branches and leaves in most species.

If you have any questions related to medical terminology or health-related topics, please provide more context so I can offer an accurate and helpful response.

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.

Chiroptera is the scientific order that includes all bat species. Bats are the only mammals capable of sustained flight, and they are distributed worldwide with the exception of extremely cold environments. They vary greatly in size, from the bumblebee bat, which weighs less than a penny, to the giant golden-crowned flying fox, which has a wingspan of up to 6 feet.

Bats play a crucial role in many ecosystems as pollinators and seed dispersers for plants, and they also help control insect populations. Some bat species are nocturnal and use echolocation to navigate and find food, while others are diurnal and rely on their vision. Their diet mainly consists of insects, fruits, nectar, and pollen, although a few species feed on blood or small vertebrates.

Unfortunately, many bat populations face significant threats due to habitat loss, disease, and wind turbine collisions, leading to declining numbers and increased conservation efforts.

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.

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.

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.

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.

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!

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.

Carbon tetrachloride is a colorless, heavy, and nonflammable liquid with a mild ether-like odor. Its chemical formula is CCl4. It was previously used as a solvent and refrigerant, but its use has been largely phased out due to its toxicity and ozone-depleting properties.

Inhalation, ingestion, or skin contact with carbon tetrachloride can cause harmful health effects. Short-term exposure can lead to symptoms such as dizziness, headache, nausea, and vomiting. Long-term exposure has been linked to liver and kidney damage, as well as an increased risk of cancer.

Carbon tetrachloride is also a potent greenhouse gas and contributes to climate change. Its production and use are regulated by international agreements aimed at protecting human health and the environment.

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.

Anaerobiosis is a state in which an organism or a portion of an organism is able to live and grow in the absence of molecular oxygen (O2). In biological contexts, "anaerobe" refers to any organism that does not require oxygen for growth, and "aerobe" refers to an organism that does require oxygen for growth.

There are two types of anaerobes: obligate anaerobes, which cannot tolerate the presence of oxygen and will die if exposed to it; and facultative anaerobes, which can grow with or without oxygen but prefer to grow in its absence. Some organisms are able to switch between aerobic and anaerobic metabolism depending on the availability of oxygen, a process known as "facultative anaerobiosis."

Anaerobic respiration is a type of metabolic process that occurs in the absence of molecular oxygen. In this process, organisms use alternative electron acceptors other than oxygen to generate energy through the transfer of electrons during cellular respiration. Examples of alternative electron acceptors include nitrate, sulfate, and carbon dioxide.

Anaerobic metabolism is less efficient than aerobic metabolism in terms of energy production, but it allows organisms to survive in environments where oxygen is not available or is toxic. Anaerobic bacteria are important decomposers in many ecosystems, breaking down organic matter and releasing nutrients back into the environment. In the human body, anaerobic bacteria can cause infections and other health problems if they proliferate in areas with low oxygen levels, such as the mouth, intestines, or deep tissue wounds.

Carbon sequestration is the process of capturing and storing atmospheric carbon dioxide (CO2), a greenhouse gas, to mitigate climate change. It can occur naturally through processes such as photosynthesis in plants and absorption by oceans. Artificial or engineered carbon sequestration methods include:

1. Carbon Capture and Storage (CCS): This process captures CO2 emissions from large point sources, like power plants, before they are released into the atmosphere. The captured CO2 is then compressed and transported to suitable geological formations for long-term storage.

2. Ocean Sequestration: This method involves directly injecting CO2 into the deep ocean or enhancing natural processes that absorb CO2 from the atmosphere, such as growing more phytoplankton (microscopic marine plants) through nutrient enrichment.

3. Soil Carbon Sequestration: Practices like regenerative agriculture, agroforestry, and cover cropping can enhance soil organic carbon content by increasing the amount of carbon stored in soils. This not only helps mitigate climate change but also improves soil health and productivity.

4. Biochar Sequestration: Biochar is a type of charcoal produced through pyrolysis (heating biomass in the absence of oxygen). When added to soils, biochar can increase soil fertility and carbon sequestration capacity, as it has a high resistance to decomposition and can store carbon for hundreds to thousands of years.

5. Mineral Carbonation: This method involves reacting CO2 with naturally occurring minerals (like silicate or oxide minerals) to form stable mineral carbonates, effectively locking away the CO2 in solid form.

It is important to note that while carbon sequestration can help mitigate climate change, it should be considered as one of many strategies to reduce greenhouse gas emissions and transition towards a low-carbon or carbon-neutral economy.

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.

Carbon disulfide is a colorless, volatile, and flammable liquid with the chemical formula CS2. It has a unique odor that is often described as being similar to that of rotten eggs or garlic. In industry, carbon disulfide is primarily used as a solvent in the production of rayon and cellophane.

In medicine, exposure to carbon disulfide has been linked to various health problems, including neurological disorders, cardiovascular disease, and reproductive issues. Long-term exposure can lead to symptoms such as headaches, dizziness, memory loss, and peripheral neuropathy. It is also considered a potential occupational carcinogen, meaning that it may increase the risk of cancer with prolonged exposure.

It's important for individuals who work in industries where carbon disulfide is used to follow proper safety protocols, including using appropriate personal protective equipment and monitoring air quality to minimize exposure.

I'm sorry for any confusion, but "seasons" is not a term that has a medical definition. Seasons refer to the four divisions of the year (spring, summer, autumn or fall, and winter) based on the position of the earth in its orbit around the sun. If you have any questions related to health or medicine, I'd be happy to try to help answer those!

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.

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.

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.

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.

Biological evolution is the change in the genetic composition of populations of organisms over time, from one generation to the next. It is a process that results in descendants differing genetically from their ancestors. Biological evolution can be driven by several mechanisms, including natural selection, genetic drift, gene flow, and mutation. These processes can lead to changes in the frequency of alleles (variants of a gene) within populations, resulting in the development of new species and the extinction of others over long periods of time. Biological evolution provides a unifying explanation for the diversity of life on Earth and is supported by extensive evidence from many different fields of science, including genetics, paleontology, comparative anatomy, and biogeography.

Phylogeny is the evolutionary history and relationship among biological entities, such as species or genes, based on their shared characteristics. In other words, it refers to the branching pattern of evolution that shows how various organisms have descended from a common ancestor over time. Phylogenetic analysis involves constructing a tree-like diagram called a phylogenetic tree, which depicts the inferred evolutionary relationships among organisms or genes based on molecular sequence data or other types of characters. This information is crucial for understanding the diversity and distribution of life on Earth, as well as for studying the emergence and spread of diseases.

Carbon tetrachloride poisoning refers to the harmful effects on the body caused by exposure to carbon tetrachloride, a volatile and toxic chemical compound. This substance has been widely used in various industrial applications, such as a solvent for fats, oils, and rubber, a fire extinguishing agent, and a refrigerant. However, due to its high toxicity, the use of carbon tetrachloride has been significantly reduced or phased out in many countries.

Ingestion, inhalation, or skin absorption of carbon tetrachloride can lead to poisoning, which may cause various symptoms depending on the severity and duration of exposure. Acute exposure to high concentrations of carbon tetrachloride can result in:

1. Central nervous system depression: Dizziness, headache, confusion, drowsiness, and, in severe cases, loss of consciousness or even death.
2. Respiratory irritation: Coughing, wheezing, shortness of breath, and pulmonary edema (fluid accumulation in the lungs).
3. Cardiovascular effects: Increased heart rate, low blood pressure, and irregular heart rhythms.
4. Gastrointestinal symptoms: Nausea, vomiting, abdominal pain, and diarrhea.
5. Liver damage: Hepatitis, jaundice, and liver failure in severe cases.
6. Kidney damage: Acute kidney injury or failure.

Chronic exposure to carbon tetrachloride can lead to long-term health effects, including:

1. Liver cirrhosis (scarring of the liver) and liver cancer.
2. Kidney damage and kidney disease.
3. Peripheral neuropathy (damage to the nerves in the limbs), causing numbness, tingling, or weakness.
4. Increased risk of miscarriage and birth defects in pregnant women exposed to carbon tetrachloride.

Treatment for carbon tetrachloride poisoning typically involves supportive care, such as oxygen therapy, fluid replacement, and monitoring of vital signs. In some cases, specific treatments like activated charcoal or gastric lavage may be used to remove the substance from the body. Prevention is crucial in minimizing exposure to this harmful chemical by following safety guidelines when handling it and using appropriate personal protective equipment (PPE).

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.

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.

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.

A "carbon footprint" is not a medical term, but it is an environmental concept that has become widely used in recent years. It refers to the total amount of greenhouse gas emissions produced to directly or indirectly support human activities, usually expressed in equivalent tons of carbon dioxide (CO2).

Greenhouse gases include carbon dioxide, methane, nitrous oxide, and fluorinated gases, among others. These gases trap heat in the atmosphere and contribute to global warming and climate change.

A carbon footprint can be calculated for an individual, organization, event, or product by adding up all the emissions associated with its production, use, and disposal. This includes direct emissions from sources such as transportation, heating, and industrial processes, as well as indirect emissions from electricity generation, supply chain activities, and waste management.

Reducing carbon footprints is an important strategy for mitigating climate change and reducing the negative impacts on human health associated with a warming planet, such as increased heat-related illnesses, respiratory problems, and infectious diseases.

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.

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.

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.

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.

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.

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 "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.

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.

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.

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!

"Soot" is not typically considered a medical term, but it does have relevance to public health and medicine due to its potential health effects. Soot is a general term for the fine black or brown particles that are produced when materials burn, such as in fires, industrial processes, or vehicle emissions. It is made up of a complex mixture of substances, including carbon, metals, and other organic compounds.

Inhaling soot can lead to respiratory problems, cardiovascular issues, and cancer. This is because the tiny particles can penetrate deep into the lungs and even enter the bloodstream, causing inflammation and damage to tissues. Prolonged exposure or high concentrations of soot can have more severe health effects, particularly in vulnerable populations such as children, the elderly, and those with pre-existing medical conditions.

Carboxyhemoglobin (COHb) is a form of hemoglobin that has bonded with carbon monoxide (CO), a colorless, odorless gas. Normally, hemoglobin in red blood cells binds with oxygen (O2) to carry it throughout the body. However, when exposed to CO, hemoglobin preferentially binds with it, forming carboxyhemoglobin, which reduces the amount of oxygen that can be carried by the blood. This can lead to hypoxia (lack of oxygen in tissues) and potentially serious medical consequences, including death. Carbon monoxide exposure can occur from sources such as smoke inhalation, vehicle exhaust, or faulty heating systems.

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.

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.

... , Carbon, Lists of isotopes by element). ... Stable carbon isotopes in carbon dioxide are utilized ... Has 2 halo neutrons Carbon-11 or 11 C is a radioactive isotope of carbon that decays to boron-11. This decay mainly occurs due ... The least stable isotope is 8 C , with a half-life of 3.5(1.4)×10−21 s. Light isotopes tend to decay into isotopes of boron and ... Cosmogenic isotopes Environmental isotopes Isotopic signature Radiocarbon dating "Standard Atomic Weights: Carbon". CIAAW. 2009 ...
Organic carbon contains less of the stable isotope Carbon-13, or 13C, relative to the initial inorganic carbon from the ... Understanding these variations in carbon fractionation across species is applied in isotope geochemistry and ecological isotope ... Carbon on Earth naturally occurs in two stable isotopes, with 98.9% in the form of 12C and 1.1% in 13C. The ratio between these ... "On the Relationship Between Carbon Isotope Discrimination and the Intercellular Carbon Dioxide Concentration in Leaves". ...
"Oxygen-isotope trends and seawater temperature changes across the Late Cambrian Steptoean positive carbon-isotope excursion ( ... The Steptoean Positive Carbon Isotope Excursion (SPICE) was a geological event which occurred about 495 million years ago near ... "A global carbon isotope excursion (SPICE) during the Late Cambrian: relation to trilobite extinctions, organic-matter burial ... "A global carbon isotope excursion (SPICE) during the Late Cambrian: relation to trilobite extinctions, organic-matter burial ...
Examples of non-radioactive medical isotopes are: Deuterium in deuterated drugs Carbon-13 used in liver function and metabolic ... A medical isotope is an isotope used in medicine. The first uses of isotopes in medicine were in radiopharmaceuticals, and this ... The most common isotope used in diagnostic scans is Tc-99m (Technetium-99m), being used in approximately 85% of all nuclear ... Another well-known radioactive isotope used in medicine is I-131 (Iodine-131), which is used as a radioactive label for some ...
Carbon isotope ratios can also be used to distinguish between marine, freshwater, and terrestrial food sources. Carbon isotope ... Carbon isotopes are analysed in archaeology to determine the source of carbon at the base of the foodchain. Examining the 12C/ ... "Carbon Isotopes, Photosynthesis, and Archaeology: Different pathways of photosynthesis cause characteristic changes in carbon ... For example, most carbon is present as 12C, with approximately 1% being 13C. The ratio of the two isotopes may be altered by ...
Interpretation of carbon isotope effects are usually complicated by simultaneously forming and breaking bonds to carbon. Even ... Kinetic isotope effects that are greater than 1 are referred to as normal kinetic isotope effects, while kinetic isotope ... The observation of a primary 13C isotope effect at C3, an inverse 2H isotope effect, a secondary 13C isotope effect at C2, and ... it is reasonable to expect detectable carbon isotope effects. When 13C is used as the label, the change in mass of the isotope ...
See isotopes of carbon for notes about the measurement. Light radioactive neon isotopes usually decay to fluorine or oxygen, ... Neon (10Ne) possesses three stable isotopes: 20 Ne , 21 Ne , and 22 Ne . In addition, 17 radioactive isotopes have been ... Articles with short description, Short description with empty Wikidata description, Isotopes of neon, Neon, Lists of isotopes ... This isotope has not yet been observed; given data is inferred or estimated from periodic trends. The isotopic composition ...
A practical use is radiocarbon dating with carbon-14. Stable isotope Environmental isotopes "Natural Isotopes". www.soest. ... Natural isotopes are either stable isotopes or radioactive isotopes that have a sufficiently long half-life to allow them to ... isotope is U-238. Many elements have both natural and artificial isotopes. For example, hydrogen has three natural isotopes and ... Natural isotopes must be either stable, have a half-life exceeding about 7×107 years (there are 35 isotopes in this category, ...
Isotopic labeling Isotopes of hydrogen Isotopes of carbon; δ13C Isotopes of oxygen; δ18O Isotopes of nitrogen; δ15N Isotopes of ... Isotope Isotopologue Isotopomer Isotope analysis Isotopic signature Stable Isotope Ratio Isotope geochemistry Isotope-ratio ... The original carbon isotope reference material was a Belemnite fossil from the PeeDee Formation in South Carolina, known as the ... The carbon isotope reference frame was later established in Vienna against a hypothetical material called the Vienna Pee Dee ...
... isotope ratios of the bulk chemical mixture, or isotope ratios of individual constituent compounds. Stable isotopes of carbon ... The tube is made of glassy carbon with glassy carbon filling in which way oxygen isotope can be measured simultaneously without ... δDSecondary carbon < δDTertiary carbon. The fractionation factors between carbon sites also decrease with increasing ... The isotope ratio of carbon in the steroids of athletes has been used to determine whether these steroids originated from the ...
A carbon steel collimator assembly is located just outboard of the beam tube window. This collimator assembly provides further ... Media related to High Flux Isotope Reactor at Wikimedia Commons Bryan, Chris (October 2011). "High Flux Isotope Reactor". Oak ... The High Flux Isotope Reactor (HFIR) is a nuclear research reactor at Oak Ridge National Laboratory (ORNL) in Oak Ridge, ... Like the target positions, a type of PTP capsule is available that houses up to nine 2-inch (51 mm) long isotope or materials ...
Carbon has two stable isotopes, 12C and 13C, and one radioactive isotope, 14C. The stable carbon isotope ratio, δ13C, is ... USGS Tritium/Helium-3 Dating Hydrologic Isotope Tracers - Helium Cosmogenic isotopes Environmental isotopes Geochemistry ... Isotope Geochemistry". Retrieved 2009-01-18. Saltzman, Matthew R (2002). "Carbon isotope (d13C) stratigraphy across the ... National Isotope Development Center Reference information on isotopes, and coordination and management of isotope production, ...
Because stable carbon isotope ratios of plant tissues change based on the inorganic carbon sources for photosynthesis, ... O'Leary, Marion H. (1988). "Carbon Isotopes in Photosynthesis". BioScience. 38 (5): 328-336. doi:10.2307/1310735. JSTOR 1310735 ... These meadows account for more than 10% of the ocean's total carbon storage. Per hectare, it holds twice as much carbon dioxide ... "Mechanistic interpretation of carbon isotope discrimination by marine macroalgae and seagrasses". Functional Plant Biology. 29 ...
C3 plants preferentially use the lighter of two isotopes of carbon in the atmosphere, 12C, which is more readily involved in ... O'Leary, Marion (May 1988). "Carbon Isotopes in Photosynthesis". BioScience. 38 (5): 328-336. doi:10.2307/1310735. JSTOR ... but the carbon isotope record suggests that they were too scarce to impact the atmospheric composition until around 850 million ... being closer to C3 plants if they fix most carbon in the day and closer to C4 plants if they fix all their carbon at night. ...
The ratio of carbon-13 and carbon-12 isotopes in these types of plants is as follows: C4 plants: -16 to -10 ‰ CAM plants: -20 ... Carbon isotopes: you are what you eat Hair-rising research Ayacucho Archaeo Isotope Project The pursuit of isotopic and ... In addition, there are two types of plants with different biochemical pathways; the C3 carbon fixation, where the isotope ... Farquhar, G D; Ehleringer, J R; Hubick, K T (1989). "Carbon Isotope Discrimination and Photosynthesis". Annual Review of Plant ...
... naturally occurring isotopes. The isotope carbon-12 (12C) forms 98.93% of the carbon on Earth, while carbon-13 (13C) forms the ... Carbon chauvinism Carbon detonation Carbon footprint Carbon star Carbon planet Gas carbon Low-carbon economy Timeline of carbon ... Carbon can form very long chains of interconnecting carbon-carbon bonds, a property that is called catenation. Carbon-carbon ... Isotopes of carbon are atomic nuclei that contain six protons plus a number of neutrons (varying from 2 to 16). Carbon has two ...
Carbon, Isotopes of carbon, Environmental isotopes, Geochemistry, Paleoclimatology). ... ISBN 978-1-4443-3301-5. Mook, W. G., & Tan, F. C. (1991). Stable carbon isotopes in rivers and estuaries. Biogeochemistry of ... This signal is also a function of the amount of carbon burial; when organic carbon is buried, more 12C is locked out of the ... O'Leary, M. H. (1988). "Carbon Isotopes in Photosynthesis". BioScience. 38 (5): 328-336. doi:10.2307/1310735. JSTOR 1310735. ...
The stable isotope composition of amino acids refers to the abundance of heavy and light non-radioactive isotopes of carbon ( ... Bonds to heavy isotopes are stronger than bonds to light isotopes, making reactions involving heavier isotopes proceed slightly ... This allows the sources of carbon in food webs to be identified. The isotope effect associated with transamination also makes ... Carbon skeletons from these diverse sources are further modified before transamination, the addition of an amino group that ...
Methane Isotope Carbon isotopes Hydrogen isotopes Isotopic signature Isotope geochemistry Isotopologue Isotopomer Clumped ... each of which has two stable isotopes. For carbon, 98.9% are in the form of carbon-12 (12C) and 1.1% are carbon-13 (13C); while ... Clumped isotope composition is calculated relative to the random distribution of carbon and hydrogen isotopes in the methane ... The abundance of the clumped isotopes provides information independent from the traditional carbon or hydrogen isotope ...
Most of the isotopes with atomic mass numbers below 14 decay to isotopes of carbon, while most of the isotopes with masses ... Articles with short description, Short description matches Wikidata, Isotopes of nitrogen, Nitrogen, Lists of isotopes by ... creating carbon-14, which decays back to nitrogen-14 with a half-life of 5700(30) years. Nitrogen-15 is a rare stable isotope ... Two sources of nitrogen-15 are the positron emission of oxygen-15 and the beta decay of carbon-15. Nitrogen-15 presents one of ...
The isotopes of carbon can be separated in the form of carbon dioxide gas by cascaded chemical exchange reactions with amine ... An isotopical pure diamond is a type of diamond that is composed entirely of one isotope of carbon. Isotopically pure diamonds ... or the less common 13C isotope. Compared to natural diamonds that are composed of a mixture of 12C and 13C isotopes, ... The 12C isotopically pure, (or in practice 15-fold enrichment of isotopic number, 12 over 13 for carbon) diamond gives a 50% ...
The most widely studied and used isotopes in archaeology are carbon, oxygen, nitrogen, strontium and calcium. An isotope is an ... The ratio of different carbon isotopes naturally fluctuates over time, and, by analysing the composition of carbon dioxide (CO2 ... whereas C4 plants fix it into a 4-carbon molecule, and have a carbon isotope signature with higher 13C. This signature ... As with carbon, oxygen isotopic ratio variances can be attributed to specific locations and the proportion of O isotopes can ...
Isotopes neighbor each other vertically. Examples include carbon-12, carbon-13, and carbon-14 in the table above. Isotones are ... carbon-12, and nitrogen-14 (as N − Z = 0 for each pair), or boron-12, carbon-14, and nitrogen-16 (as N − Z = 2 for each pair). ... Isotopes are nuclides with the same number of protons but differing numbers of neutrons; that is, they have the same atomic ... Examples include carbon-14, nitrogen-15, and oxygen-16 in the table above. Isobars are nuclides with the same number of ...
Carbon isotopes indicate "dry woodland" conditions. This seeming contradiction between the seasonally dry climate and tropical ...
Zeebe, R; Wolf-Gladrow, D (2001). CO2 in seawater: Equilibrium, Kinetics, Isotopes. Elsevier Science. p. 360. "Fifth Assessment ... The Oceanic carbon cycle is a central process to the global carbon cycle and contains both inorganic carbon (carbon not ... The oceanic carbon cycle (or marine carbon cycle) is composed of processes that exchange carbon between various pools within ... and organic carbon (carbon that is, or has been, incorporated into a living thing). Part of the marine carbon cycle transforms ...
Klein, R.G. (2013). "Stable carbon isotopes and human evolution". PNAS. 110 (26): 10470-2. Bibcode:2013PNAS..11010470K. doi: ... More direct stable isotope evidence from Neanderthal bodies also indicates a heavy, though by no means exclusive reliance on ... In February 2019, scientists reported evidence, based on isotope studies, that at least some Neanderthals may have eaten meat. ... This is corroborated by stable carbon isotopic evidence indicating the consumption of plants found along riversides and under ...
Zeebe, Richard E.; Wolf-Gladrow, Dieter A. (15 October 2001). CO2 in Seawater: Equilibrium, Kinetics, Isotopes. Amsterdam. ISBN ... Total inorganic carbon (CT or TIC) is the sum of the inorganic carbon species. Carbon compounds can be distinguished as either ... Particulate inorganic carbon (PIC) is the other form of inorganic carbon found in the ocean. Most PIC is the CaCO3 that makes ... Inorganic carbon is found primarily in simple compounds such as carbon dioxide (CO2), carbonic acid (H2CO3), bicarbonate (HCO−3 ...
Carbon has three naturally occurring isotopes. About 99% of carbon on Earth is carbon-12 (12C), about 1% is carbon-13 (13C), ... This fractionation of carbon isotopes is caused by kinetic isotope effects and mass dependence of CO2 diffusivity. The overall ... doi:10.1016/0160-4120(79)90005-9. Farquhar, G. D.; Ehleringer, J. R.; Hubick, K. T. (1989). "Carbon Isotope Discrimination and ... is a change in the ratio of the atmospheric concentrations of heavy isotopes of carbon (13C and 14C) by the admixture of large ...
Hodson, Martin J.; Parker, Adrian G.; Leng, Melanie J.; Sloane, Hilary J. (May 2008). "Silicon, oxygen and carbon isotope ... Isotopes of silicon Isotope geochemistry Stable isotope ratio Isotope-ratio mass spectrometry Sutton, Jill N.; André, Luc; ... Silicon isotope biogeochemistry is the study of environmental processes using the relative abundance of Si isotopes. As the ... Currently, there are four main analytical methods for the measurement of Si isotopes: Gas Source Isotope-Ratio Mass ...
"Direct analysis of carbon isotope variability in albumins by liquid flow-injection isotope ratio mass spectrometry". J. Am. Soc ... For example, carbon isotope ratios are measured relative to the international standard for C. The C standard is produced from a ... Many radiogenic isotope measurements are made by ionization of a solid source, whereas stable isotope measurements of light ... The isotope-ratio mass spectrometer (IRMS) allows the precise measurement of mixtures of naturally occurring isotopes. Most ...
The most common is stable carbon-12, followed by stable carbon-13. Carbon-14 is a natural radioactive isotope with a half-life ... Carbon also forms many oxides such as carbon monoxide, carbon suboxide, and carbon dioxide. Carbon forms disulfides and ... Carbon is present in the atmosphere in the form of carbon monoxide, carbon dioxide, and methane. Carbon is a key constituent of ... followed by the stable isotope germanium-72, the stable isotope germanium-70, and the stable isotope germanium-73. The isotope ...
... the three isotopes of carbon are known as carbon-12, carbon-13, and carbon-14, often abbreviated to 12C, 13C, and 14C. Carbon ... Thus, for example, there are three main isotopes of carbon. All carbon atoms have 6 protons in the nucleus, but they can have ... For example, all carbon atoms contain 6 protons in their atomic nucleus; so the atomic number of carbon is 6. Carbon atoms may ... Of the 80 elements with at least one stable isotope, 26 have only one single stable isotope. The mean number of stable isotopes ...
Isotopes of carbon, Carbon, Lists of isotopes by element). ... Stable carbon isotopes in carbon dioxide are utilized ... Has 2 halo neutrons Carbon-11 or 11 C is a radioactive isotope of carbon that decays to boron-11. This decay mainly occurs due ... The least stable isotope is 8 C , with a half-life of 3.5(1.4)×10−21 s. Light isotopes tend to decay into isotopes of boron and ... Cosmogenic isotopes Environmental isotopes Isotopic signature Radiocarbon dating "Standard Atomic Weights: Carbon". CIAAW. 2009 ...
The project Talos Dome ice core - climate-related variability of iron, carbon dioxide and carbon isotopes in the southern ocean ... Collaborating laboratories analysed concentrations of carbon dioxide and carbon isotopes in the gas that was contained in air ... Final Activity Report Summary - TDICOSO (Talos Dome ice core ? Climate-related variability of Iron, CO2 and Carbon isotopes in ... Talos Dome ice core Climate-related variability of Iron, CO2 and Carbon isotopes in the Southern Ocean. ...
Changes in soil organic matter with cropping as measured by organic carbon fractions and 13C natural isotope abundance. *Rod D ... Changes in soil organic matter with cropping as measured by organic carbon fractions and 13C natural isotope abundance. Plant ...
Coastal wetlands are major global carbon sinks, however, they are heterogeneous and dynamic ecosystems. To characterize spatial ... Static chamber gas fluxes and carbon and nitrogen isotope content of age-dated sediment cores from a Phragmites wetland in Sage ... Static chamber gas fluxes and carbon and nitrogen isotope content of age-dated sediment cores from a Phragmites wetland in Sage ... Coastal wetlands are major global carbon sinks, however, they are heterogeneous and dynamic ecosystems. To characterize spatial ...
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Source-diagnostic dual-isotope composition and optical properties of water-soluble organic carbon and elemental carbon in the ... Source-diagnostic dual-isotope composition and optical properties of water-soluble organic carbon and elemental carbon in the ... Source-diagnostic dual-isotope composition and optical properties of water-soluble organic carbon and elemental carbon in the ... 3000 years of carbon monoxide records show positive impact of global intervention in the 1980s ...
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Stable carbon isotope fractionation of chloroethenes by dehalorespiring isolates. Environ Sci Technol 41(12):4277-85. PMID: ... This is the first measurement of carbon isotope fractionation by Dehalococcoides isolates and of TCE transformation by S. ... Assessing Bioremediation of Chloroethenes through Stable Carbon Isotope Fractionation. View Research Brief as PDF(73KB) ... Alvarez-Cohens research group studied stable carbon isotope fractionation during the reduction of TCE using three test systems ...
LIU, XIANZHAO; SU, QING; LI, CHAOKUI; ZHANG, Yong; and WANG, Qing (2014) "Responses of carbon isotope ratios of C_3 herbs to ... Responses of carbon isotope ratios of C_3 herbs to humidity index in northern China. ... Arid and humid climate zones, C_3 herbaceous plants, carbon isotope, humidity index, northern China ...
The content and isotopic compositions of water dissolved organic carbon (DOC) and dissolved inorganic carbon (DIC) from the ... This study aims to complement existing research on the carbon cycle of water in reservoirs, for the effective control of ... Keywords: carbon isotope; dissolved inorganic carbon(DIC); dissolved organic carbon(DOC); sources; summer; water from Miyun ... Concentration and Carbon Isotope Composition of DOC and DIC in the Miyun Reservoir Watershed in Summer] [Article in Chinese] ...
Victor Conte: Time for commissions to use Carbon Isotope Ratio testing. By Zach Arnold , November 21, 2011 ... But theres another test called the CIR or Carbon Isotope Ratio test that can differentiate between a natural testosterone ... If athletic commissions can use inexpensive tests to measure correct metrics such as hematocrit levels & carbon isotope ratios ... 20 Responses to "Victor Conte: Time for commissions to use Carbon Isotope Ratio testing". ...
Influence of diagenetic and post-sampling processes on biogenic carbonate oxygen and carbon isotopes in suboxic sediments ... Influence of diagenetic and post-sampling processes on biogenic carbonate oxygen and carbon isotopes in suboxic sediments , EGU ...
Heart-cutting two-dimensional liquid chromatography combined with isotope ratio mass spectrometry for the determination of ... Determination of carbon isotope ratios for honey samples by means of a liquid chromatography/isotope ratio mass spectrometry ... Determination of carbon isotope ratios of methanol and acetaldehyde in air samples by gas chromatography-isotope ratio mass ... Stable carbon isotope analysis of amino acid enantiomers by conventional isotope ratio mass spectrometry and combined gas ...
12C stable carbon isotope ratios of protein and sugar compounds with a combination of elemental analyzer - isotope ratio mass ... spectrometry and liquid chromatography - isotope ratio mass spectrometry (. 13C-EA/LC-IRMS). Lutz Elflein and Kurt-Peter Raezke ... of honey adulteration with invert sugar syrups from various C3 and C4 plant sources was realized by coupling an isotope ratio ...
Geochemical Preservation of the Steptoean Positive Carbon Isotope Excursion (SPICE) Event in Dolomites of the Furongian ... Geochemical Preservation of the Steptoean Positive Carbon Isotope Excursion (SPICE) Event in Dolomites of the Furongian ... Geochemical Preservation of the Steptoean Positive Carbon Isotope Excursion (SPICE) Event in Dolomites of the Furongian ... Isotopes. Geographic Coverage. Madison County, Illinois. Publisher. Champaign, Ill.: Illinois State Geological Survey, Prairie ...
Home/Disequilibrium/Understanding isotope exchange at chemical equilibrium for better carbon dating. Understanding isotope ... Comments Off on Understanding isotope exchange at chemical equilibrium for better carbon dating 23 Views ... To assess the effect of mineral surface and size on the exchange rates of C and O isotopes, different grain sizes of natural ... The specific isotope exchange process was unclear between 72 hours and 2112 hours during the large calcite experiments and ...
We propose that isotopically labeled CO2 is incorporated into plant-derived carbon and then into the DNA of rhizosphere ... There are currently large knowledge gaps related to which soil-associated microorganisms take up plant carbon in the ... largely due to more genes for complex carbon utilization and amino acid metabolism. Given the ability to degrade cellulose, ... rhizosphere and the fate of that carbon. We conducted an experiment in which common wild oats (Avena fatua) were grown in a ...
Stable carbon and oxygen isotope ratios of planktonic foraminifera from the equatorial Atlantic. PANGAEA, https://doi.org/ ... Curry, William B; Crowley, Thomas J (1987): Stable carbon and oxygen isotope ratios of planktonic foraminifera from the ... Curry, WB; Crowley, TJ (1987): (Table 5) Stacked records of stable carbon and oxygen isotopes for Equatorial Atlantic ... Carbon isotopic records of nutrient-depleted surface water place constraints on the past fertility of the oceans and on past ...
Oxygen and carbon stable isotope tracers of Weddell Sea water masses: new data and some paleoceanographic implications ... Mackensen, A. (2001): Oxygen and carbon stable isotope tracers of Weddell Sea water masses: new data and some paleoceanographic ...
Carbon cycling within an East African lake revealed by the carbon isotope composition of diatom silica: a 25-ka record from ... Diatom frustule-bound carbon isotopes offer an original tool in examining long-term fluctuations in a lakes carbon budget and ... Carbon cycling within an East African lake revealed by the carbon isotope composition of diatom silica: a 25-ka record from ... One promising technique is to explore the carbon-isotope composition (d13Cdiatom) of organic matter incorporated within the ...
Different carbon sites in a large organic molecule have different isotope compositions. Different carbon sites may not have the ... The relative isotope enrichment between the carboxyl and methyl carbon in acetic acid is defined as ln. 13. α. carb. -. met. = ... 13R=13A12A, and A denotes carbon isotope abundance in a position. a Meinschein et al. (1974). b Rinaldi et al. (1974). c ... On-line measurement of intramolecular carbon isotope distribution of acetic acid by continuous-flow isotope ratio mass ...
Carbon isotope discrimination in Tsuga heterophylla and its relationship to mineral nutrition and growth Walia, Ankit Abstract ... The objective of my research was to explore the use of carbon isotope analysis as a physiological tool to diagnose the ... The objective of my research was to explore the use of carbon isotope analysis as a physiological tool to diagnose the ... Normally cellulose is isolated from wood samples to be analyzed for carbon isotope analysis (expressed as 813C values), but ...
Serum carbon isotope values [13C-to-12C serum carbon isotope ratio (δ(13)C)], which reflect consumption of corn- and cane-based ... Blinded serum samples were assayed for δ(13)C by natural abundance stable isotope mass spectroscopy. Multiple linear regression ... Serum carbon isotope values [13C-to-12C serum carbon isotope ratio (δ(13)C)], which reflect consumption of corn- and cane-based ... Blinded serum samples were assayed for δ(13)C by natural abundance stable isotope mass spectroscopy. Multiple linear regression ...
To see the isotopes that exist in the ScientificConstants package for a particular element, use the GetIsotopes function with ... Home : Support : Online Help : Science and Engineering : Scientific Constants : Initial Elements and Isotopes ...
Compare multiple isotopes and compute with their properties. ... Isotope data: abundance, decay properties and modes, radiation ... Do computations with isotope properties:. half life potassium-40 / carbon-14. RELATED EXAMPLES. *. ... Isotopes. Isotopes are variants of elements that differ in the number of their neutrons. Wolfram,Alpha provides data on a wide ... Properties of Isotopes. Obtain properties of isotopes, such as abundance, radiation shielding and decay chain. ...
"BIOGEOCHEMISTRY OF STABLE CARBON ISOTOPES.;s:8:\u0000*\u0000title;s:42:BIOGEOCHEMISTRY OF STABLE CARBON ISOTOPES.;s:8 ... "BIOGEOCHEMISTRY OF STABLE CARBON ISOTOPES.;s:8:\u0000*\u0000title;s:42:BIOGEOCHEMISTRY OF STABLE CARBON ISOTOPES.;s:8 ... "BIOGEOCHEMISTRY OF STABLE CARBON ISOTOPES.;s:8:\u0000*\u0000title;s:42:BIOGEOCHEMISTRY OF STABLE CARBON ISOTOPES.;s:8 ... "BIOGEOCHEMISTRY OF STABLE CARBON ISOTOPES.;s:8:\u0000*\u0000title;s:42:BIOGEOCHEMISTRY OF STABLE CARBON ISOTOPES.;s:8 ...
Table S2) Stable carbon isotope ratios of bulk sediment of ODP Leg 208 holes. *James C Zachos (Contributor) ... Stable carbon isotope ratios of bulk sediment of ODP Leg 208 holes. Unknown Publisher. 10.1594/pangaea.772044 ... Stable isotope analyses were conducted on automated gas source mass spectrometers in four laboratories. The Site 1262 and 1266 ...
Fuhe magnetic susceptibility data and high-resolution carbon isotope data are from Whalen et al.3, low-resolution carbon ... Throughout the figure, carbon isotope records in dark gray are δ13Ccarb and records in light gray are δ13Corg. The Late ... Carbon isotope stratigraphy. Bulk carbonate δ13C from the H-32, CG-1 and Sinsin sections and δ13Corg from H-32 were measured at ... 5) and carbon isotope geochemistry (blue ties in Fig. 6). In a first step, we assign an age relative to the F-F boundary to ...
Certain Radioactive isotopes require the purchase of an LSD shield *. International customers must order from:. International ... Radioactive isotopes are drop-shipped from a different location and can not be returned or refunded.. Shopping cart may not ... Also included in the set is a mixed source of Cs-137 and Zn-65 which students may use to identify an unknown isotope.. *. ... All our radioactive isotopes and sources are legal to purchase and own by the general public. See NRC Regulations. ...
Speleothem carbon isotope (δ13Cspel) records from the temperate region of western Europe are often clearly correlated to ... Here we show that speleothem carbon isotope (δ13Cspel) records may retain information on soil respiration and allow its ... Stalagmite carbon isotopes suggest deglacial increase in soil respiration in western Europe driven by temperature change. ... For stable carbon isotopes, an aliquot of powder was analysed on a ThermoFinnigan GasBench II carbonate preparation device at ...
  • Ms. Johnson is a member of the Diane M. O'Brien Laboratory and focuses her research on how we can utilize naturally occurring stable isotope ratios in circulating metabolites as biomarkers of dietary intake. (nutrition.org)
  • Previous related work from the O'Brien Laboratory published in AJCN may be of interest to readers, as well as a related commentary on the use of stable isotope ratios in nutritional epidemiology . (nutrition.org)
  • Tree-ring stable carbon isotope ratios (delta C-13) often display a decline over the industrial period (post-AD1850) that is only partly explained by changes in the isotopic ratio of carbon dioxide (CO2) and may represent a response to increased atmospheric concentrations Of CO2 (ca). (columbia.edu)
  • Responses of carbon isotope ratios of C_3 herbs to humidity index in n" by XIANZHAO LIU, QING SU et al. (tubitak.gov.tr)
  • Table 2a) Stable isotope ratios of planktonic foraminifera from sediment core EN066-38PG in the equatorial Atlantic. (pangaea.de)
  • We found that, after calibration, CLM was able to reasonably simulate the observed fluxes of energy and carbon, carbon stocks, carbon isotope ratios, and ecosystem response to water stress. (copernicus.org)
  • Analysis of stable isotope ratios from mineralised tissue has been widely used for dietary reconstruction. (springer.com)
  • In-lake organic carbon produced by algae is distinct from the terrestrial input of organic carbon from the watershed produced by vascular plants, based on their respective C/N ratios. (blogspot.com)
  • Eelgrass (Zostera marina) characteristics, sediment grain size distributions, sediment total organic carbon contents (TOC), carbon isotope ratios of sediment organic matter, and total carbon to total nitrogen ratios were measured at four lower intertidal sites in Bellingham Bay, Washington, July 2-5, 2019. (usgs.gov)
  • The intent of the working group is to characterize and utilize water isotope ratios as a climate variable. (usclivar.org)
  • Tree -ring carbon and oxygen isotope ratios from live and recently dead trees may reveal important mechanisms of tree mortality . (bvsalud.org)
  • This fractionation enables the use of stable nitrogen isotopes (δ 15 N) to infer trophic level, and high δ 15 N recorded in bone collagen usually indicates high-protein diets (Sponheimer et al. (springer.com)
  • These data including carbon and nitrogen isotopes from glacial sediments will be used to constrain process-based models of the modern and LGM ocean. (github.io)
  • Plants find it easier to use the lighter isotopes (12 C ) when they convert sunlight and carbon dioxide into food. (wikipedia.org)
  • This was done by analysing the purified effluent carbon dioxide from the reaction, at various fixed stages of completeness, by means of a mass spectrometer. (gla.ac.uk)
  • The reaction involving the heavy isotope Is a little slower than the light one, so the carbon dioxide appears to have an abnormally low C13 content and from this k12/k13 can be calculated. (gla.ac.uk)
  • Since C14 is beta-radioactive, the samples of effluent carbon dioxide were analysed by counting measured volumes in a Geiger counter, using a simple standard technique, being derived in a manner similar to that used for k12/k13. (gla.ac.uk)
  • The fact that carbon dioxide is a 'greenhouse gas' - a gas that prevents a certain amount of heat radiation escaping back to space and thus maintains a generally warm climate on Earth, goes back to an idea that was first conceived, though not specifically with respect to CO2, nearly 200 years ago. (skepticalscience.com)
  • He also found that carbon dioxide was very good at trapping heat, despite being a trace gas occurring in the hundreds of parts per million (ppm) range. (skepticalscience.com)
  • The ocean's carbon cycle is an important part of Earth's climate system because it impacts the concentration of atmospheric carbon dioxide (CO 2 ), which is a greenhouse gas. (github.io)
  • If H pylori are present, the bacteria convert the urea into carbon dioxide, which is detected and recorded in your exhaled breath after 10 minutes. (medlineplus.gov)
  • Then we can see how temperature and carbon dioxide levels have developed, and how the climate has varied between ice ages and warm periods over the past 150,000 years. (lu.se)
  • You will have the chance to pull up a core sample from the glaciers in Greenland and carry out measurements to read the temperature and carbon dioxide levels for the past 150 000 years. (lu.se)
  • To uncover historical climate data, researchers look at air bubbles preserved in the ice that contain 'old air' - by measuring the levels of carbon dioxide in these bubbles it is possible to compare historical levels with current carbon dioxide levels in the atmosphere (we currently have approximately 400 ppm CO 2 ). (lu.se)
  • However, in the long term, the emitted carbon dioxide can be stored again as the trees regrow, slowly returning the forest to a carbon sink. (lu.se)
  • The unified atomic mass unit is defined as 1/12 of the mass of an unbound atom of carbon-12 in its ground state. (wikipedia.org)
  • The weight of an atom of oxygen-16 (an oxygen atom with eight neutrons in the nucleus) was found to be 2.657 × 10 -23 grams and an atom of carbon-12 (a carbon atom with six neutrons in the nucleus) was found to weigh 1.99 × 10 -23 grams. (jrank.org)
  • An atom of carbon-12 is taken to have a mass of 12 atomic mass unit (amu). (onlinemathlearning.com)
  • A method for determining the 18O/16O ratio of organic matter composed of carbon, hydrogen, oxygen, and nitrogen is described. (eurekamag.com)
  • Stable carbon (δ¹³C) and hydrogen (δ²H) isotopes have been used to characterize hydrocarbons for exploration, development and production since the 1960s, and have re-emerged as predictive tools with the development of unconventional "tight" oil and gas plays. (onepetro.org)
  • Maturities derived from carbon and hydrogen isotopes can serve as controls in regional maturity maps, which are used to help define areas of oil, wet gas and dry gas production. (onepetro.org)
  • Stable carbon and hydrogen isotope values show a strong correlation to both initial and cumulative GOR for the unconventional Niobrara and Codell intervals of Wattenberg Field. (onepetro.org)
  • Stable isotopes of carbon (δ13C), sulfur (δ34S), oxygen (δ18O), hydrogen (δ2H), nitrogen (δ15N), and radioactive isotope of hydrogen (tritium) have been applied in combination with conventional techniques (chemical) to investigate Karachi coastal water pollution due to Layari and Malir rivers, which mainly carry the domestic and industrial wastewater of Karachi Metropolitan. (intechopen.com)
  • Hayes, J.M. Strauss, H., Kaufman, A.J., 1999, The abundance of 13 C in marine organic matter and isotopic fractionation in the global biogeochemical cycle of carbon during the past 800 Ma. (sepmstrata.org)
  • It is known that stable carbon isotope fractionation is associated with the fixation of CO in autotrophic organisms [2]. (lu.se)
  • These results demonstrate the potential of natural gas stable isotope signatures as a useful and reliable fluid quality prediction tool. (onepetro.org)
  • Wiederhold, J. G. Metal stable isotope signatures as tracers in environmental geochemistry. (nature.com)
  • 12 C and 13 C are measured as the isotope ratio δ13C in benthic foraminifera and used as a proxy for nutrient cycling and the temperature dependent air-sea exchange of CO2 (ventilation). (wikipedia.org)
  • Ordinary carbon contains about 1% of C13, so ordinary oxaloacetic acid can be used to determine the first isotope effect, i.e. , the ratio k12/k13. (gla.ac.uk)
  • Stable isotope ratio variation in natural systems reflects the dynamics of Earth systems processes and imparts isotope labels to Earth materials. (springer.com)
  • Samples analysed by continuous flow isotope ratio mass spectroscopy. (elementallab.co.uk)
  • Leaf Δ 13 C isotope analysis was applied for the common species of Q. mongolica for Haean sites to examine water use efficiency, which is the ratio of carbon gains and water losses through stomata, at different elevations. (uni-bayreuth.de)
  • Stable isotope analyses compares the ratio (δ) between these two isotopes so that increased productivity is reflected by an increase in the δ 13 C of organic matter in Lake Baikal sediments. (blogspot.com)
  • Therefore, in addition to comparing δ 13 C values, the carbon to nitrogen ratio (C/N) of the organic matter can be of used to quantify/assess algal versus higher plant (e.g. terrestrial) production. (blogspot.com)
  • 13C by isotope ratio mass spectrometry. (cdc.gov)
  • Carbon isotope stratigraphy of the St. Clair from an outcrop near Dongola Hollow and from the Schlamer #1 core, both located in Alexander County, Illinois, reveals the presence of the Ireviken (early Sheinwoodian) and Mulde (middle to upper Homerian) carbon isotope excursions. (confex.com)
  • Data for: Stratigraphy of early to middle Eocene hyperthermals from Possagno (Southern Alps, Italy) and comparison with global carbon isotope records. (mendeley.com)
  • Validation of the correlation between Niobrara and Codell production GOR and stable isotope composition was provided by an independent geochemistry dataset from the USGS. (onepetro.org)
  • Carbon isotopes in lake sediments can be used to compare algal growth rates (i.e. productivity) under different nutrient dynamics while silicon isotopes tell us specifically about the cycling of silicon (a key nutrient) in the lake over time. (blogspot.com)
  • Has 2 halo neutrons Carbon-11 or 11 C is a radioactive isotope of carbon that decays to boron-11. (wikipedia.org)
  • Left: Dissolved Inorganic Carbon (DIC) in the ocean interior arises from transport of preformed DIC from the surface plus regenerated biological carbon. (github.io)
  • A newly developed method will be applied that provides a precise and complete decomposition of dissolved inorganic carbon storage into preformed and biologically-regenerated components. (github.io)
  • 2 of biomass from inorganic carbon [2]. (lu.se)
  • Here we show the unambiguous isotopic imaging of 12 C carbon atoms embedded in 13 C graphene and the monitoring of their self-diffusion via atomic-level vibrational spectroscopy. (nature.com)
  • We first grow a domain of 12 C carbon atoms in a pre-existing crack of 13 C graphene, which is then annealed at 600 degrees Celsius for several hours. (nature.com)
  • Using scanning transmission electron microscopy-electron energy loss spectroscopy, we obtain an isotope map that confirms the segregation of 12 C atoms that diffused rapidly. (nature.com)
  • Our results demonstrate the high mobility of carbon atoms during growth and annealing via self-diffusion. (nature.com)
  • Fig. 4: Self-diffusion of carbon atoms in graphene. (nature.com)
  • Isotopes are atoms of the same element that have different number of neutrons. (onlinemathlearning.com)
  • Some of the atoms of certain isotopes are unstable because of the extra number of neutrons, and they are said to be radioactive. (onlinemathlearning.com)
  • Learn how to write atoms in isotope notation! (onlinemathlearning.com)
  • The temperature can be recreated by looking at the relationship between different oxygen isotopes (that is, different kinds of oxygen atoms). (lu.se)
  • However factors other than primary productivity can influence the carbon isotopic composition of in-lake produced organic matter, such as the concentration of atmospheric CO 2 , lake-water pH, temperature, nutrient limitation and algal growth rates. (blogspot.com)
  • We aimed at assessing whether the two climatic factors affect cork-ring isotopic composition under contrasting conditions of water availability, and, therefore, if carbon and oxygen signatures in cork can reflect tree functional (physiological and structural) responses to stressful conditions, which might be aggravated by climate change. (unl.pt)
  • Overall, stable isotopes provided valuable new insights into the drought-related variations of ecosystem C dynamics, encouraging future studies but also highlighting the need of improved methodology to disentangle short-term dynamics of isotopic composition of R (eco). (uni-bielefeld.de)
  • Diel variations in carbon isotopic composition and concentration of organic acids and their impact on plant dark respiration in different species. (uni-bielefeld.de)
  • Variations in temperature, moisture and a number of other environmental properties may be recorded as changes in ring width but also, for example, as changes in the stable carbon- and oxygen-isotope composition of wood samples. (lu.se)
  • Moreover, quantified forest water fluxes and budgets and defined relationships with environmental factors can be linked to estimate carbon fluxes of the forests as combining phloem sap Δ 13 C isotope analysis. (uni-bayreuth.de)
  • Perturbation experiments will be used in which one variable (temperature, sea ice, circulation, soluble iron fluxes) is changed at a time and the carbon decomposition is applied. (github.io)
  • Stable isotopes are different forms of an element, which have the same number of protons but differing number of neutrons. (blogspot.com)
  • is an isotope of chlorine that has 17 protons and 18 neutrons. (onlinemathlearning.com)
  • is an isotope of chlorine that has 17 protons and 20 neutrons. (onlinemathlearning.com)
  • Isotopes are versions of an atom or an element that have the same number of protons, but different numbers of neutrons. (onlinemathlearning.com)
  • In isotope notation, you can quickly show how many protons, neutrons, and electrons are in an atom. (onlinemathlearning.com)
  • Isotope notation is particularly important in nuclear chemistry, because if you're doing fission, fusion, alpha decay, beta decay, positron emission, or electron capture, you want to be able to tell how many neutrons and protons are in the nucleus. (onlinemathlearning.com)
  • Alpha particle ( ionizing radiation ) - two neutrons and two protons bound as a single particle (a helium nucleus) that is emitted from the nucleus of certain radioactive isotopes in the process of disintegration. (cdc.gov)
  • Forests supply several types of services to the local communities as well as non-local communities and recently its important role in regulations of water and carbon quantity has been received public attention with regard to climate change and water shortage problems. (uni-bayreuth.de)
  • This will be achieved by working with teachers to develop and implement a carbon cycle and climate science curriculum into their programs as part of OSU's Science and Math Investigative Lerning Experiences (SMILE) program. (github.io)
  • We thus concluded that differences in carbon isotope profiles of the hollows might point to the disturbance of the mires due to climate warming or due to differences in hydrology. (unibas.ch)
  • These results suggest that although stable isotopes signatures in cork rings are not proxies for net growth, they may be (fairly) robust indicators of trees' physiological and structural adjustments to climate and environmental changes in Mediterranean environments. (unl.pt)
  • The US CLIVAR Working Group on Observations and Modeling of Water Isotopes in the Climate System was formed in April 2018. (usclivar.org)
  • Through a combination of modern observations, past climate records, and model simulations, water isotopes hold vast potential to advance our understanding of the global hydrological cycle and how it will respond to anthropogenic greenhouse gases. (usclivar.org)
  • Ice and water normally have different distributions of the different oxygen isotopes, so it is possible to see that the balance has varied if there has been a lot of ice (cold climate) or lots of water (warm climate). (lu.se)
  • The carbon isotope compositions of the alkanes and polycyclic aromatic hydrocarbons (means -27.5 and -24.7%, respectively) reflect a primarily terrestrial organic matter source.We submitted individual aliphatic and polycyclic aromatic hydrocarbons in samples of hydrothermal petroleum from Escanaba Trough to compound specific isotope analysis to trace their origins. (usgs.gov)
  • The carbon isotope compositions of the alkanes and polycyclic aromatic hydrocarbons (means -27.5 and -24.7 per mill, respectively) reflect a primarily terrestrial organic matter source. (usgs.gov)
  • How do carbon isotopes infer past primary productivity? (blogspot.com)
  • This unit is defined as 1/12 the mass of carbon-12 (12 C) and is equal to 1.6606 × 10 -24 grams. (jrank.org)
  • On this scale, carbon-12 weighs exactly 12 atomic mass units. (jrank.org)
  • In these lessons, we will learn about Isotopes, Isotope Notation, Atomic Mass Unit (amu), and how to calculate the Atomic Mass of an element. (onlinemathlearning.com)
  • The following diagrams show the isotopes of chlorine and how to calculate the relative atomic mass. (onlinemathlearning.com)
  • In this video, we'll learn about what isotopes are and how to write atomic number and mass number in isotope notation. (onlinemathlearning.com)
  • How do you determine and calculate isotope abundance when you know the relative atomic mass (also known as atomic weight), as measured in amu or atomic mass numbers? (onlinemathlearning.com)
  • If the relative atomic mass of chlorine is 35.45, what is the abundance of each isotope? (onlinemathlearning.com)
  • Beta particle ( ionizing radiation ) - a charged particle emitted from the nucleus of certain unstable atomic nuclei (radioactive isotopes), having the charge and mass of an electron. (cdc.gov)
  • Further data for radioisotopes (radioactive isotopes) of carbon are listed (including any which occur naturally) below. (webelements.com)
  • Further data for naturally occuring isotopes of carbon are listed above. (webelements.com)
  • The isotope data indicate that the Ireviken and Mulde are stratigraphically adjacent, suggesting that the middle Wenlock is extremely condensed or missing in these sections. (confex.com)
  • This study is the first of its kind to analyse carbon, nitrogen and sulphur stable isotope data from skeletons of the eleventh-seventeenth centuries in Portugal. (springer.com)
  • Richards and Hedges 1999 ), especially when combined with carbon isotope data. (springer.com)
  • Modern observations and paleoclimate data provide a wealth of information on changes to the carbon cycle. (github.io)
  • We dive deep into this really novel study, touching on stable isotopes, controlled feeding trials, essential and non-essential amino acids, and emerging biomarkers of intake for use in experimental and observational nutrition studies. (nutrition.org)
  • Stable isotope labeling by amino acids in cell culture, SILAC, as a simple and accurate approach to expression proteomics. (nature.com)
  • Carbon isotopic records of nutrient-depleted surface water place constraints on the past fertility of the oceans and on past atmospheric pCO2 levels. (pangaea.de)
  • We submitted individual aliphatic and polycyclic aromatic hydrocarbons in samples of hydrothermal petroleum from Escanaba trough to compound specific isotope analysis to trace their origins. (usgs.gov)
  • Stable isotope analysis can be executed pre-completion on samples obtained from mud gas and/or gas desorbing from cuttings and core. (onepetro.org)
  • The spatial resolutions of even the most sensitive isotope analysis techniques based on light or ion probes are limited to a few hundred nanometres. (nature.com)
  • Isotope analysis in the transmission electron microscope. (nature.com)
  • Stable isotope analysis (N and C) of fossil cereal grains is regularly explored as a means of obtaining insights to past crop growing conditions and agricultural practices. (lu.se)
  • Considering the consistent salinity-dependent discrimination of H-2 to salinity, and no significant diagenetic alteration of taraxerol delta H-2 values on centennial time scales, taraxerol H isotopes are a promising proxy for hydroclimate reconstruction in mangrove and mangrove-adjacent systems. (unibas.ch)
  • To explore this idea, we reconstruct the contemporaneous global extent of marine anoxia using uranium (U) isotopes from Ludfordian marine carbonates sampled from two widely spaced paleogeographic locations. (lu.se)
  • Background radioactivity - radioactive elements in the natural environment including those in the crust of the earth (like radioactive potassium, uranium, and thorium isotopes) and those produced by cosmic rays. (cdc.gov)
  • The positive δ 13 C excursion and the extinctions have been linked to increased marine productivity (ocean eutrophication), leading to increased organic carbon burial, and expansion of marine anoxia in shallow continental seas. (lu.se)
  • Also useful in determining carbon sources because different plant groups have seperate and identifiable isotopic signatures. (sepmstrata.org)
  • We return to our previous questions to find new answers with the help of osteological methods - DNA and isotope analyses", says Torbjörn Ahlström, Professor of Historic Osteology. (lu.se)
  • In this study, we address the relation between carbon and oxygen stable isotopes of cork rings and precipitation and temperature, in two distinct locations of southwestern Portugal-the (wetter) Tagus basin peneplain and the (drier) Grândola mountains. (unl.pt)
  • Observations have shown that carbon-13 isotopes are present in the atmosphere of the planet TYC 8998-760-1 b, which have never been discovered on a planet outside the solar system in the past. (curiosmos.com)
  • There are three naturally occurring isotopes of carbon: 12, 13, and 14. (wikipedia.org)
  • This table shows information about naturally occuring isotopes , their atomic masses , their natural abundances , their nuclear spins , and their magnetic moments . (webelements.com)
  • This is not to be confused with the relative percentage isotope abundances which totals 100% for all the naturally occurring isotopes. (webelements.com)
  • Freshwater fish exhibit variation in δ 13 C depending on the ecosystem as freshwater plants have numerous sources of carbon, unlike terrestrial plants (Zohary et al. (springer.com)
  • Little is known about how much greenhouse gases are released during and after a wildfire, about how much of the stored carbon is lost, or about how the energy exchange at the Earth's surface is changed because of a fire. (lu.se)
  • Our joint efforts focus on isotopes 3 H and 14 C near nuclear power plants. (lu.se)
  • Radiotracer studies of bound pesticide residues in soil, plants and food : report of a research co-ordination meeting on isotopic tracer-aided studies of unextractable or bound pesticide residues in soil, plants and food / organized by the Joint FAO/IAEA Division of Isotope and Radiation Applications of Atomic Energy for Food and Agricultural Development and held at Neuherberg, 11-15 July 1983. (who.int)
  • Quantification, nature and bioavailability of bound 14C-pesticide residues in soil, plants and food : proceedings of the Final Research Co-ordination Meeting on Isotopic Tracer-Aided Studies of Unextractable or Bound Pesticide Residues in Soil, Plants and Food / organized by the Joint FAO/IAEA Division of Isotope and Radiation Applications of Atomic Energy for Food and Agricultural Development and held in Gainesville, Florida, from 25 to 29 March 1985. (who.int)
  • The C-12 atom has been given the atomic weight of exactly 12.000000000 and is used as the basis upon which the atomic weight of other isotopes is determined. (webelements.com)
  • Results of search for 'au:'Joint FAO/IAEA Division of Isotope and Radiation Applications of Atomic Energy for Food and Agricultural Development. (who.int)
  • Marketing and consumer acceptance of irradiated foods : report of the Consultants' Meeting on Marketing, Market Testing and Consumer Acceptance of Irradiated Foods, Vienna, 27 September - 1 October 1982 / organized by the Joint FAO/IAEA Division of Isotope and Radiation Applications of Atomic Energy for Food and Agricultural Development. (who.int)
  • Use of irradiation as a quarantine treatment of agricultural commodities : final report of a consultants' meeting held in Honolulu, Hawaii, 21-23 November 1983 / organized by the Joint FAO/IAEA Division of Isotope and Radiation Applications of Atomic Energy for Food and Agricultural Development. (who.int)
  • Nuclear techniques in the study and control of parasitic diseases of livestock : proceedings of the Final Research Co-ordination Meeting on the Use of Nuclear Techniques in the Study and Control of Parasitic Diseases of Farm Animals, held in Vienna from 11 to 14 May 1987 / organized by the Joint FAO/IAEA Division of Isotope and Radiation Applications of Atomic Energy for Food and Agricultural Development. (who.int)
  • In this regard, the quantification of water and carbon in the forest ecosystem is critical starting point of evaluation of their services. (uni-bayreuth.de)
  • Unger S, Maguas C, Pereira JS, Aires LM, David TS, Werner C. Disentangling drought-induced variation in ecosystem and soil respiration using stable carbon isotopes. (uni-bielefeld.de)
  • Studying forest recovery after wildfire is vital for understanding the net impact of the wildfire on the forest ecosystem and its carbon balance. (lu.se)
  • cellulose extraction and blue-stain fungus on retrospective studies of carbon and oxygen isotope variation in live and dead trees. (bvsalud.org)
  • To investigate changes in Lake Baikal's primary productivity, we are analysing organic carbon (δ 13 C organic ) and silicon (δ 30 Si) isotopes at the BGS. (blogspot.com)
  • The San Juan Bay Estuary, Puerto Rico, contains mangrove forests that store significant amounts of organic carbon in soils and biomass. (usgs.gov)
  • Isotope abundances of carbon. (webelements.com)
  • Here we will go through the algebra and reasoning to figure out the amount of abundances of the isotopes, in percentages and in decimals. (onlinemathlearning.com)
  • Ions from each analyte and each carbon-13 labeled internal standard are monitored, and the abundances of each ion are measured. (cdc.gov)
  • Additionally, the human samples have higher stable isotope differences, in comparison with faunal samples, than would be expected within the food web, particularly for δ 13 C. This human bone collagen δ 13 C enrichment may reflect a diet rich in aquatic protein intake, which is also supported by δ 34 S archived in human and faunal samples, and the presence of oysters and cockles shells at the excavation. (springer.com)
  • During photosynthesis algae take up carbon, but they prefer to take up the lighter isotope ( 12 C) rather than the heavier ( 13 C) because the former is easier to utilise. (blogspot.com)
  • In soils with suppressed degradation due to anoxic conditions, stable carbon isotope depth profiles are either more or less uniform indicating no or very low degradation or depth profiles turn to lighter values due to an enrichment of recalcitrant organic substances during anaerobic mineralisation which are depleted in 13C. (unibas.ch)