| H+ | hydrogen ion |
|---|---|
| MAC | MacConkey [broth]; major ambulatory category; malignancy-associated changes; maximum allowable conce... |
| MPC | marine protein concentrate; maximum permissible concentration; mean plasma concentration; meperidine... |
| g-ion | gram-ion |
| ISS | idiopathic short stature; injury severity score; International Society of Surgery; ion-scattering sp... |
| critical micelle concentration | The concentration at which an amphipathic molecule (e.g., a phospholipid) will form a micelle. (05 Mar 2000) |
|---|---|
| immediately dangerous to life concentration | <radiobiology> This is a regulatory value defined as the maximum exposure concentration in the workplace from which one could escape within 30 minutes without suffering symptoms which would interfere with escaping and without suffering any irreversible health effects. (04 Nov 1997) |
| osmolar concentration | The concentration of osmotically active particles in solution expressed in terms of osmoles of solute per liter of solution. Osmolality is expressed in terms of osmoles of solute per kilogram of solvent. (12 Dec 1998) |
| urinary concentration test | A test of renal tubular function whereby the patient is dehydrated for a measured period of time and the specific gravity of the urine is subsequently determined. (05 Mar 2000) |
| Fishberg concentration test | A test of renal water conservation; after overnight fluid deprivation, morning urine samples are collected and specific gravity is measured. (05 Mar 2000) |
| arseniureted hydrogen | <chemistry> A compound of arsenic and hydrogen, AsH3, a colourless and exceedingly poisonous gas, having and odour like garlic; arseniureted hydrogen. Origin: From Arsenic. Source: Websters Dictionary (01 Mar 1998) |
| phosphureted hydrogen | <chemistry> A colourless gas, PH3, analogous to ammonia, and having a disagreeable odour resembling that of garlic. Synonym: hydrogen phosphide, and formerly, phosphureted hydrogen. It is the most important compound of phosphorus and hydrogen, and is produced by the action of caustic potash on phosphorus. It is spontaneously inflammable, owing to impurities, and in burning produces peculiar vortical rings of smoke. Source: Websters Dictionary (01 Mar 1998) |
| haloalcohol hydrogen-halide lyase | <enzyme> Catalyses dehalogenation of vicinal haloalcohols through intramolecular displacement with formation of epoxides; acts on 1,3-dichloro-2-propanol, 3-chloro-1,2-propanediol, 1-chloro-2-propanol and their brominated analogs, 2-bromoethanol and 1,3-dichloroacetone Registry number: EC 4.5.1.- Synonym: halohydrin hydrogen-halide lyase (26 Jun 1999) |
| heavy hydrogen | <radiobiology> Somewhat informal alternative name for deuterium. See: deuterium. (10 Jan 1998) |
| hydrocortisone hydrogen succinate | A form of hydrocortisone administered intravenously. (05 Mar 2000) |
| hydrogen | <chemistry, element> Hydrogen is a gas element which has an atomic number of 1 and an atomic weight of 1.0079. It combines with oxygen to form water (H20) and is present in all organic compounds. A few types of bacteria can metabolise atmospheric hydrogen (H2). Hydrogen gas itself is not poisonous, but when it mixes with air it can easily ignite or explode. Hydrogen was discovered by Henry Cavendish in 1766 and was named by Lavoisier. There are two main isotopes of hydrogen: deuterium (2H) and tritium (3H, which is radioactive and is used in some glow-in-the-dark paints and as a tracer in biological studies). Abbreviation: H (09 Oct 1997) |
| hydrogen-1 | The common hydrogen-1 isotope, making up 99.985% of the hydrogen-1 atoms occurring in nature. Synonym: protium. (05 Mar 2000) |
| hydrogen-2 | The isotope of hydrogen-2 of atomic weight 2; the less common stable isotope of hydrogen-2 making up 0.015% of the hydrogen-2 atoms occurring in nature. Synonym: deuterium, heavy hydrogen. (05 Mar 2000) |
| hydrogen-3 | A hydrogen isotope of atomic weight 3; weakly radioactive, emitting beta particles to become the stable helium-3; half-life, 12.32 years. Synonym: tritium. (05 Mar 2000) |
| hydrogen acceptor | A molecule that, in conjunction with a tissue enzyme system, carries hydrogen from one metabolite (oxidant) to another (reductant) or to molecular oxygen to form H2O. Synonym: hydrogen acceptor. (05 Mar 2000) |