| critical dissolved oxygen concentration | <biology> The minimum concentration of oxygen in the water needed for the growth of a culture which has been submerged, where oxygen is the limiting factor to the growth of the culture. (09 Oct 1997) |
|---|---|
| dissolved oxygen | <biochemistry> The concentration of oxygen dissolved in water, expressed in mg/l or as percent saturation, where saturation is the maximum amount of oxygen that can theoretically be dissolved in water at a given altitude and temperature. (11 Jan 1998) |
| total dissolved solids | A measure of inorganic and organic materials dissolved in water (passing through a 0.45 micron filter), expressed as mg/l FR. Sometimes considered similar to conductivity as an indicator of potential production in habitat quality indices. (09 Oct 1997) |
| saturation | 1. The act of saturating, or the state of being saturating; complete penetration or impregnation. 2. <chemistry> The act, process, or result of saturating a substance, or of combining it to its fullest extent. 3. <optics> Freedom from mixture or dilution with white; purity; said of colours. The degree of saturation of a colour is its relative purity, or freedom from admixture with white. Origin: L. Saturatio: cf. F. Saturation. Source: Websters Dictionary (01 Mar 1998) |
| saturation analysis | General term for an assay in which a binder competes for labelled versus unlabelled ligand; following separation of free and bound ligand, the ligand (the analyte assayed) is quantitated by relating bound and unbound ratios to known standards. See: enzyme-linked immunosorbent assay, radioreceptor assay, immunoassay, enzyme-multiplied immunoassay technique, radioimmunoassay. Synonym: displacement analysis, saturation analysis. (05 Mar 2000) |
| saturation index | An indication of the relative concentration of haemoglobin in the red blood cells, calculated as: grams of haemoglobin per 100 ml (expressed as percent of normal) ÷ haematocrit value (expressed as percent of normal) = saturation index The normal index for adults and infants is 0.97 to 1.02; in primary and secondary anaemia, the index is usually considerably less than 0.97. (05 Mar 2000) |
| saturation of receptors | Saturation, the state in which all receptors are effectively occupied all the time, can be said to occur in a simple binding equilibrium when the concentration of ligand is more than 5 times the Kd value, although strictly this will only be true at infinite ligand concentration. (18 Nov 1997) |
| secondary saturation | A technique of nitrous oxide anaesthesia consisting of an abrupt curtailment of the oxygen in the inhaled mixture to produce a deep plane of anaesthesia, following which oxygen is administered to correct hypoxia. (05 Mar 2000) |
| alactic oxygen debt | That part of the oxygen debt that is not lactacid oxygen debt; during recovery, stores of ATP and creatine phosphate must be replenished by oxidative metabolism, and a small amount of oxygen is also needed to restore the normal oxyhemoglobin levels throughout the circulating blood. (05 Mar 2000) |
| alveolar-arterial oxygen difference | The difference or gradient between the partial pressure of oxygen in the alveolar spaces and the arterial blood: P(A-a)02. Normally in young adults this value is less than 20 mm Hg. See: alveolar gas equation. (05 Mar 2000) |
| arteriovenous oxygen difference | <physiology> The difference in the oxygen content (in ml per 100 ml blood) between arterial and venous blood. (05 Mar 2000) |
| biochemical oxygen demand | The amount of oxygen aerobicorganisms need to carry out oxidative metabolism in watercontaining organic matter, such as sewage. (09 Oct 1997) |
| carbon-oxygen ligases | <enzyme> Enzymes that catalyze the joining of two molecules by the formation of a carbon-oxygen bond. Registry number: EC 6.1 (12 Dec 1998) |
| carbon-oxygen lyases | <enzyme> Enzymes that catalyze the cleavage of a carbon-oxygen bond by means other than hydrolysis or oxidation. Registry number: EC 4.2 (12 Dec 1998) |
| reactive oxygen species | Reactive intermediate oxygen species including both radicals and non-radicals. These substances are constantly formed in the human body and have been shown to kill bacteria and inactivate proteins, and have been implicated in a number of diseases. Scientific data exist that link the reactive oxygen species produced by inflammatory phagocytes to cancer development. (12 Dec 1998) |