| amorphous | <cell biology> Having an irregular or undefined shape or structure. (05 Feb 1998) |
|---|---|
| amorphous fraction of adrenal cortex | Noncrystalline residue of an acetone extract of the adrenal cortex after crystalline steroids, e.g., corticosterone, deoxycorticosterone, etc., have been isolated. (05 Mar 2000) |
| amorphous insulin zinc suspension | Sterile suspension of insulin in buffered water for injection, modified by the addition of zinc chloride such that the solid phase of the suspension is amorphous; it contains 40 or 80 units per ml; the duration of action is equivalent to that of insulin injection. Synonym: amorphous insulin zinc suspension, semilente insulin. (05 Mar 2000) |
| amorphous phosphorus | Red phosphorus, an allotropic form of phosphorus formed by heating ordinary phosphorus, in the absence of oxygen, to 260캜; it occurs as an amorphous dark red mass or powder, nonpoisonous, and much less flammable than ordinary phosphorus; it may be reconverted to the latter by heating to 454.4캜 in nitrogen gas. (05 Mar 2000) |
| selenium | <element> Essential trace element that must be provided as a supplement in serum free culture media for most animal cells. (18 Nov 1997) |
| selenium compounds | Inorganic compounds that contain selenium as an integral part of the molecule. (12 Dec 1998) |
| selenium deficiency | deficiency of the essential mineral selenium causes keshan disease, a fatal form of cardiomyopathy (disease of the heart muscle) first observed in keshan province in china and since found elsewhere. According to the national academy of sciences, the recommended dietary allowances of selenium are 70 milligrams per day for men and 55 milligrams per day for women. Food sources of selenium include seafoods, some meats such as kidney and liver, and some grains and seeds (12 Dec 1998) |
| selenium excess | Too much of the mineral selenium may cause reversible changes in the hair (balding) and nails, garlic odour to the breath, intestinal distress, weakness and slower mentation (slowed mental functionning). According to the national academy of sciences, the recommended dietary allowances of selenium are 70 milligrams per day for men and 55 milligrams per day for women. (12 Dec 1998) |
| selenium poisoning | Chronic poisoning of horses, cattle, and swine, caused by ingestion of grains and forage raised on soils high in selenium; it occurs only in arid regions, from eating certain plants which are selenium accumulators. (05 Mar 2000) |
| selenium radioisotopes | Unstable isotopes of selenium that decay or disintegrate emitting radiation. Se atoms with atomic weights 70-73, 75, 79, 81, and 83-85 are radioactive selenium isotopes. (12 Dec 1998) |
| selenium sulfide | A mixture of crystalline selenium monosulfide and solid solutions of selenium and sulfur in an amorphous form, containing 52 to 55.5% Se; used in the treatment of seborrhoea of the scalp or dandruff; it is applied to the scalp as a suspension. (05 Mar 2000) |
| selenium transferase | <enzyme> Converts phosphoseryl-trna to selenocysteinyl-trna; product of sela gene; converts seryl-trna(sec)(uca) to selenocysteyl-trna(sec)(uca) in pyridoxal-phosphate dependent reaction Registry number: EC 2.- Synonym: se-transferase, selenocysteine synthase (26 Jun 1999) |
| nickel-iron-selenium hydrogenase | <enzyme> From desulfovibrio baculatus Registry number: EC 1.12.- Synonym: nifese hydrogenase (26 Jun 1999) |
| deficiency, selenium | Deficiency of the essential mineral selenium causes Keshan disease, a fatal form of cardiomyopathy (disease of the heart muscle) first observed in Keshan province in China and since found elsewhere. According to the National Academy of Sciences, the Recommended Dietary Allowances of selenium are 70 milligrams per day for men and 55 milligrams per day for women. Food sources of selenium include seafoods, some meats such as kidney and liver, and some grains and seeds. (12 Dec 1998) |
| Abbe test plate | <equipment> A long, wedge-shaped coverslip about 0.20 mm thick at one end and 0.10 to 0.12 mm at the other end coated chemically with a silver film on which are ruled horizontal lines. at each variation in thickness of 0.01 mm there are vertical lines. By means of oblique illumination and by focusing on different portions of the plate, it is possible to determine the optimum coverslip thickness for any objective and also, for microscopes with drawtubes, the tube length for best objective performance. The approximate freedom from spherical and chromatic aberrations can also be estimated. Small isolated bits of silver near the edges of the lines form good objects for the star test (05 Aug 1998) |