| specific activity | 1. <chemistry> The number of activity units (whatever is appropriate) per unit of mass, volume or molarity. 2. <radiobiology> Total activity of a given nuclide per gram of a compound, element or radioactive nuclide. Perhaps most often usage, in the context of radiochemicals, the number of microcuries per micromole. (16 Dec 1997) |
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| specific anergy | A reduction of the normal or usual immunologic response resulting from a reaction to a specific allergen. Synonym: specific anergy. (05 Mar 2000) |
| specific antigens | Antigen's that characterise a single genus of microorganisms. (05 Mar 2000) |
| specific antiserum | See: antiserum. (05 Mar 2000) |
| specific capsular substance | A soluble type-specific polysaccharide produced during active growth of virulent pneumococci composing a large part of the capsule. Synonym: pneumococcal polysaccharide, soluble specific substance, specific soluble polysaccharide, specific soluble sugar. (05 Mar 2000) |
| specific cause | A cause the action of which definitely produces the condition in question. (05 Mar 2000) |
| specific cholinesterase | <enzyme, neurology, physiology> An enzyme that breaks down unused acetylcholine in the synaptic cleft (the space between neurons), this enzyme is necessary to restore the synaptic cleft so it is ready to transmit the next nerve impulse. (06 May 1997) |
| specific compliance | The compliance of a structure divided by its initial volume, more specifically for the lungs, the compliance divided by the functional residual capacity. (05 Mar 2000) |
| specific disease | A disease produced by the action of a special pathogenic microorganism. (05 Mar 2000) |
| specific dynamic action | The increase of heat production caused by the ingestion of food, especially of protein. (05 Mar 2000) |
| specific epithet | The label (or designation) of a particular species in the binomial nomenclature system. For example: coli is the specific epithet of Escherichia coli. (09 Oct 1997) |
| specific extinction | Absorbance (of light) per unit path length (usually the centimeter) and per unit of mass concentration. Compare: molar absorption coefficient. Synonym: absorbancy index, absorptivity, extinction coefficient, specific extinction. (05 Mar 2000) |
| specific granule | One of the two main classes of granules found in neutrophils: contain lactoferrin, lysozyme, Vitamin B12 binding protein and elastase. Are released more readily than the azurophil (primary) granules which have typical lysosmal contents. (18 Nov 1997) |
| specific gravity | A measure of concentration. It is the weight of a substance, as compared (as a ratio) with that of an equal volume of water. (27 Sep 1997) |
| specific haemolysin | A sensitizing, complement-fixing, haemolytic antibody that reacts totally or completely with red blood cells of the antigenic type used to stimulate the formation of the haemolysin. (05 Mar 2000) |