| arsenic acid | <chemical> The hydrate of arsenic oxide or arsenic pentoxide which forms arsenates with certain bases. (05 Mar 2000) |
|---|
| arsenic | 1. <chemistry> One of the elements, a solid substance resembling a metal in its physical properties, but in its chemical relations ranking with the nonmetals. It is of a steel-gray colour and brilliant luster, though usually dull from tarnish. It is very brittle, and sublimes at 356 deg Fahrenheit. It is sometimes found native, but usually combined with silver, cobalt, nickel, iron, antimony, or sulphur. Orpiment and realgar are two of its sulphur compounds, the first of which is the true arsenticum of the ancients. The element and its compounds are active poisons. Specific gravity from 5.7 to 5.9. Atomic weight. Symbol As. 2. Arsenious oxide or arsenious anhydride; called also arsenious acid, white arsenic, and ratsbane. <chemistry> Pertaining to, or derived from, arsenic; said of those compounds of arsenic in which this element has its highest equivalence; as, arsenic acid. Origin: L. Arsenicum, Gr, yellow orpiment, perh. Fr. Or better Attic masculine, male, on account of its strength, or fr. Per. Zernikh: cf. F. Arsenic. Source: Websters Dictionary (01 Mar 1998) |
|---|---|
| arsenic-fast | Resistant to the poisonous action of arsenic; denoting especially spirochetes and other protozoan parasites, which acquire resistance after repeated administration of the drug. (05 Mar 2000) |
| arsenic pigmentation | Generalised but spotty increased melanin pigmentation of the skin in chronic arsenic poisoning. (05 Mar 2000) |
| arsenic poisoning | A severe poisoning that occurs after the exposure (ingested or inhaled). Signs and symptoms include: nausea, vomiting, diarrhoea, rapid heart rate, apprehension and difficulty breathing. (27 Sep 1997) |
| arsenic trihydride | <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) |
| arsenic trioxide | As2O3;dissolves in water to give arsenous acid, H3AsO3; used in the treatment of skin diseases and malaria, and as a tonic; also used externally as a caustic. Synonym: arsenous oxide, white arsenic. (05 Mar 2000) |
| white arsenic | As2O3;dissolves in water to give arsenous acid, H3AsO3; used in the treatment of skin diseases and malaria, and as a tonic; also used externally as a caustic. Synonym: arsenous oxide, white arsenic. (05 Mar 2000) |
| 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) |