| ORS | olfactory reference syndrome; oral rehydration solution; oral surgery, oral surgeon; Orthopaedic Res... |
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| RAD | radial artery catheter; radiation absorbed dose; radical; radiography or radiographic; reactive airw... |
| rad | radiation absorbed dose; radial; radian; radical; radius; root [Lat. radix] |
| RM | radical mastectomy; random migration; radon monitor; range of movement; red marrow; reference materi... |
| RND | radical neck dissection; radionuclide dacryography; reactive neurotic depression |
| carbon | <chemistry, element> Sixth element (Z=6) in the periodic table, has 6 protons, often described as the basis of life on earth because of its chemical properties, has potential for use with silicon as a low-activation structural material for fusion reactors, in the form silicon carbide. Carbon tiles are often used in plasma-facing components because its low Z makes carbon a relatively nice impurity. It is also useful as a neutron moderator. See: low-activation materials, plasma-facing components. Abbreviation: C (13 Nov 1997) |
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| carbon-11 | A cyclotron-produced, positron-emitting radioisotope of carbon with a half-life of 20.3 minutes; used in positron-emitting tomography. (05 Mar 2000) |
| carbon-12 | The standard of atomic mass, 98.90% of natural carbon. (05 Mar 2000) |
| carbon-13 | A stable natural isotope, 1.1% of natural carbon. (05 Mar 2000) |
| carbon-14 | A beta-emitter with a half-life of 5715 years, widely used as a tracer in studying various aspects of metabolism; naturally occurring 14C, arising from cosmic ray bombardment, is used to date relics containing natural carbonaceous materials. (05 Mar 2000) |
| carbon bisulfide | <chemical> Carbon disulfide (cs2). A colourless, flammable, poisonous liquid, cs2. It is used as a solvent, and is a counterirritant and has local anaesthetic properties but is not used as such. It is highly toxic with pronounced CNS, haematologic, and dermatologic effects. Chemical name: Carbon disulfide (12 Dec 1998) |
| carbon compounds, inorganic | Inorganic compounds that contain carbon as an integral part of the molecule but are not derived from hydrocarbons. (12 Dec 1998) |
| carbon dichloride | An anthelmintic against hookworm and other nematodes. Synonym: carbon dichloride, ethylene tetrachloride, tetrachloroethylene. (05 Mar 2000) |
| carbon dioxide | <biochemistry, physiology> A metabolic byproduct of carbohydrate metabolism. Carbon Dioxide collects in the tissues, is cleared by the blood (via the veins) and removed from the body via the lungs when we exhale air. Abbreviation: CO2 (13 Nov 1997) |
| carbon dioxide acidosis | <biochemistry> A metabolic derangement of acid-base balance where the blood pH is abnormally low. Causes include haemorrhagic shock, cardiogenic shock, severe dehydration, sepsis, toxic ingestion (for example isopropyl alcohol, methanol), alcoholic ketoacidosis, lactic acidosis, renal failure and diabetic ketoacidosis. Respiratory acidosis will occur if the lungs are not ventilating properly resulting in an excess of carbon dioxide in the body. (25 Jun 1999) |
| carbon dioxide blood level | A measure of the bicarbonate level in the blood based on a venipuncture specimen. The serum carbon dioxide is one of the normally reported values in the electrolytes profile. Lower levels of carbon dioxide indicate an acidosis. The normal level is 20 to 29 mEq/L. Lower than normal levels can indicate diabetic ketoacidosis, lactic acidosis, alcoholic ketoacidosis, kidney disease, renal failure, diarrhoea, Addison's disease, ethylene glycol poisoning or methanol poisoning. Greater than normal levels can be seen with excessive vomiting, hyperaldosteronism and Cushing's syndrome. (27 Sep 1997) |
| carbon dioxide content | The total carbon dioxide available from serum or plasma following addition of acid; measured routinely in hospital laboratories as a component of electrolyte profiles. (05 Mar 2000) |
| carbon dioxide cycle | First, an organism which can photosynthesise (such as a plant or some bacteria) will absorb carbon dioxide (CO2) from the air and incorporate it into its body or turn it into organic matter. Then, other organisms which cannot photosynthesise will eat the organic matter, or the photosynthesising organism, and release carbon dioxide gas as a waste product back into the air. (09 Oct 1997) |
| carbon dioxide electrode | A glass electrode in a film of bicarbonate solution covered by a thin plastic membrane permeable to carbon dioxide but impermeable to water and electrolytes; the carbon dioxide pressure of a gas or liquid sample quickly equilibrates through the membrane and is measured in terms of the resulting pH of the bicarbonate solution, as sensed by the glass electrode; commonly used to analyze arterial blood samples. Synonym: Severinghaus electrode. (05 Mar 2000) |
| carbon dioxide elimination | The rate at which carbon dioxide enters the alveolar gas from the blood, equal in the steady state to the metabolic production of carbon dioxide by tissue metabolism throughout the body; units: ml/min STPD or mmol/min. (05 Mar 2000) |