| DHA | dehydroacetic acid; dehydroascorbic acid; dehydroepiandrosterone; dihydroacetic acid; dihydroxyaceto... |
|---|---|
| GA | Gamblers Anonymous; gastric analysis; gastric antrum; general anesthesia; general angiography; gener... |
| IAA | imidazoleacetic acid; indoleacetic acid; infectious agent, arthritis; insulin autoantibody; Internat... |
| NA | Avogadro constant or number; nalidixic acid; Narcotics Anonymous; network administrator; neuraminida... |
| NAA | N-acetyl aspartate; naphthaleneacetic acid; neutral amino acid; neutron activation analysis; neutrop... |
| free water | Water in the body that can be removed by ultrafiltration and in which substances can be dissolved. (05 Mar 2000) |
|---|---|
| free water clearance | The amount of water excreted in the urine beyond that which would accompany the excreted solutes if the urine were isosmotic with plasma; it represents the loss of body water in excess of solute tending to raise body osmolality and making urine hyposmotic. Unlike other clearance's, it is calculated by subtracting the osmolal clearance from the actual volume of urine excreted per minute. A negative value for free water clearance represents the amount of water that the body has reclaimed from isosmotic tubule fluid to make the urine hyperosmotic and to lower body osmolality. (05 Mar 2000) |
| free wave | <radiobiology> A wave (for example, electromagnetic) traveling in a homogeneous infinite medium (no boundary conditions). (09 Oct 1997) |
| free will | 1. A will free from improper coercion or restraint. "To come thus was I not constrained, but did On my free will." (Shak) 2. The power asserted of moral beings of willing or choosing without the restraints of physical or absolute necessity. Source: Websters Dictionary (01 Mar 1998) |
| Rambourg's chromic acid-phosphotungstic acid stain | <technique> A stain for glycoproteins, used with an electron microscope, with which ultrathin tissue sections reveal complex carbohydrates in the same locations as shown by Rambourg's periodic acid-chromic methenamine-silver stain. (05 Mar 2000) |
| a1-acid glycoprotein | <biology> Plasma protein of mammals and birds, 38% carbohydrate. In humans a single chain glycoprotein of 39 kD. Increased levels are associated with inflammation, pregnancy and various diseases. (18 Nov 1997) |
| abscisic acid | <biochemistry> A lipid hormone that inhibits cell growth in plants, it is associated with fruit drop, leaf death and seed dormancy. It is synthesised in the plastids from carotenoids. This hormone helps plants deal with water loss, and its effects can be reversed with gibberellins. (06 May 1997) |
| abscisic acid 8'-hydroxylase | <enzyme> Catalyses conversion of abscisic acid to 8'-hydroxyabscisic acid, which rearranges to phaseic acid Registry number: EC 1.14.99.- Synonym: aba 8'-hydroxylase (26 Jun 1999) |
| acetic acid | <chemical> The acid most commonly associated with vinegar, it is the most commercially important organic acid and is used to manufacture a wide range of chemical products, such as plastics and Acetobacter but, except for making vinegar, is usually made through synthetic processes. Derivatives of acetic acid which may be formed by substitution reactions. Mono- and di-substituted, as well as, halogenated compounds have been synthesised. Experimentally, alpha- and n2- substituted acetic acids have been examined for their anti-inflammatory activity and effect on the central nervous system respectively. Additionally, limited exposure data has been collected on dibromo and dichloroacetic acids to determine whether they pose health effects. Synonym: ethanoic acid. (26 Jun 1999) |
| acetoacetic acid | CH3COCH2COOH;one of the ketone bodies, formed in excess and appearing in the urine in starvation or diabetes. Synonym: diacetic acid. (05 Mar 2000) |
| acetohydroxamic acid | C2H5NO2; N-Hydroxyacetamide;an inhibitor of urease, used as adjunctive therapy in chronic urea-splitting urinary infections. (05 Mar 2000) |
| acetrizoic acid | <chemical> A water-soluble, iodinated radiographic contrast medium, used as sodium acetrizoate in hysterosalpingography. Pharmacological action: contrast media. Chemical name: Benzoic acid, 3-(acetylamino)-2,4,6-triiodo- (12 Dec 1998) |
| acetylsalicylic acid | <drug> An odourless, white, slightly bitter drug used to reduce pain, fever, inflammation and sometimes to prevent blood clotting. Also called aspirin. Some people cannot tolerate it because it can cause stomach bleeding, however. It is soluble in both water and alcoholand melts at 132 to 136 degrees C. (06 May 1997) |
| acetyltannic acid | An astringent used for treatment of diarrhoea. Synonym: diacetyltannic acid, tannylacetate. (05 Mar 2000) |
| acid | <chemical, chemistry> A fundamental category of many compounds whose water-based solutions have a sour taste, turn blue litmus paper red and can combine with metals to form salts. They are chemical compounds which yield hydrogen ions or protons when dissolved in water, whose hydrogen can be replaced by metals or basic radicals, or which react with bases to form salts and water (neutralization). An extension of the term includes substances dissolved in media other than water. Specific types of acids include: Arrhenius acid: any chemical that increases the number of free hydrogen ions (H+) when added to a water-based solution. The more free hydrogens produced, the stronger the acid. Bronsted or Bronsted-Lowry acid: any chemical that acts as a proton donor in a chemical reaction. Lewis acid: any chemical that accepts two electrons to form a covalent bond during a chemical reaction. (13 Nov 1997) |