| drug activity | A measure of the physiological response a drug produces. A less active drug produces less response (and visa versa). (12 Dec 1998) |
|---|---|
| insulin-like activity | A measure of substances, usually in plasma, that exert biologic effects similar to those of insulin in various bioassays; sometimes used as a measure of plasma insulin concentrations; always gives higher values than immunochemical techniques for the measurement of insulin. (05 Mar 2000) |
| intrinsic sympathomimetic activity | The property of a drug that causes activation of adrenergic receptors so as to produce effects similar to stimulation of the sympathetic nervous system. (05 Mar 2000) |
| optical activity | The ability of a material to rotate the plane of polarized light. (09 Oct 1997) |
| triggered activity | One or a series of spontaneously generated heart beats originating from an action potential that produces an after-depolarisation which reaches activation threshold. (05 Mar 2000) |
| unit of thyrotrophic activity | The activity of an amount of an extract of the anterior lobe of the hypophysis which, given daily for 5 days, will cause the thyroid of a guinea pig (weighing 200 g) to reach a weight of 600 mg. (05 Mar 2000) |
| zone of polarizing activity | <cell biology> The small group of mesenchyme cells in avian limb buds that is located at the posterior margin of the developing bud and that produces a substance, possibly retinoic acid, that provides positional information to the developing limb bud. (18 Nov 1997) |
| brush heap structure | Haphazard interlocking of fibrils in a gel or hydrocolloid impression material. (05 Mar 2000) |
| gel structure | Brush heap structure of fibrils giving firmness to hydrocolloids. (05 Mar 2000) |
| genetic fine structure | The study of genes on the level of their nucleotide sequences and what happens to their molecular structure at that level. (09 Oct 1997) |
| chi structure | <molecular biology> The name for the X-shaped structure which forms during the recombination process between two plasmids, or circular pieces, of DNA. The Greek letter chi resembles this structure. (05 Jan 1998) |
| group structure | The informal or formal organization of a group of people based on a network of personal relationships which is influenced by the size and composition, etc., of the group. (12 Dec 1998) |
| molecular structure | The location of the atoms, groups or ions relative to one another in a molecule, as well as the number and location of chemical bonds. (12 Dec 1998) |
| cointegrate structure | A structure of DNA produced by the fusion of two replicons, one possessing a transposon. (05 Mar 2000) |
| cruciform structure | A structure, shaped like a cross, which can form during homologous recombination when inverted base-pair repeats pair with each other on the same strand of DNA instead of with homologous sections on a different strand of DNA. (09 Oct 1997) |