| anion | A negatively-charged ion. (09 Oct 1997) |
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| anion exchange | The process by which an anion in a mobile (liquid) phase exchanges with another anion previously bound to a solid, positively charged phase, the latter being an anion exchanger. It takes place when Cl- is exchanged for OH- in desalting. The reaction is Cl- (in solution) + (OH- on anion exchanger+) → (Cl- on anion exchanger) + OH- (in solution); combined with cation exchange, NaCl is removed from solution. Anion exchange may also be used chromatographically, to separate anions, and medicinally, to remove an anion (e.g., Cl-) from gastric contents or bile acids in the intestine. (05 Mar 2000) |
| anion exchange resin | <chemistry> A resin with fixed cationic groups which is used in chromatography to separate anionic molecules. A High molecular weight, insoluble polymers that contain functional anionic groups capable of undergoing exchange reactions. These resins are used for ion exchange chromatography, as gastric antacids, hypocholesteraemics, etc. (14 Aug 2000) |
| anion exchanger | Family of Integral membrane proteins that perform the exchange of chloride and bicarbonate across the plasma membrane. Best known is Band III protein of the red blood cell. (18 Nov 1997) |
| anion gap | <biochemistry> The difference between the sum of the measured cations and anions in the plasma or serum calculated as follows: (Na + K) -(Cl + HCO3) = < 20 mmol/l. Elevated values may occur in diabetic or lactic acidosis; normal or low values occur in bicarbonate-losing metabolic acidoses. Synonym: cation-anion difference. (05 Mar 2000) |
| anionic | Pertaining to or containing an anion. (18 Nov 1997) |
| anionic detergent | Detergents in which the hydrophilic funtion is fulfilled by an anionic grouping. Fatty acids are the best known natural products in this class, but it is doubtful if they have a specific detergent function in any biological system. The important synthetic species are aliphatic sulphate esters, for example sodium dodecyl sulphate (SDS or SLS). (18 Nov 1997) |
| anionic detergents | Detergent's, such as soaps (alkali metal salts of long-chain fatty acids), that carry a negative electric charge on a lipid-like molecule and exert a limited antibacterial effect. (05 Mar 2000) |
| anionic neutrophil activating peptide | <cytokine> A cytokine that activates neutrophils and attracts neutrophils and T-lymphocytes. It is released by several cell types including monocytes, macrophages, T-lymphocytes, fibroblasts, endothelial cells, and keratinocytes by an inflammatory stimulus. Il-8 is a member of the beta-thromboglobulin superfamily and structurally related to platelet factor 4. Acronym: IL-8 (12 Dec 1998) |
| anionotropy | The migration of a negative ion in tautomeric changes. (05 Mar 2000) |
| anions | Negatively charged atoms or radicals. (12 Dec 1998) |
| ambident anion | <chemistry> A group of atoms that carry an overall negative charge and which can donate electrons to electron acceptors such as metal atoms. (09 Oct 1997) |
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| cation-anion difference | <biochemistry> The difference between the sum of the measured cations and anions in the plasma or serum calculated as follows: (Na + K) -(Cl + HCO3) = < 20 mmol/l. Elevated values may occur in diabetic or lactic acidosis; normal or low values occur in bicarbonate-losing metabolic acidoses. Synonym: cation-anion difference. (05 Mar 2000) |
| superoxide anion | <chemistry> A harmful derivative of oxygen capable of oxidative destruction of cell components. (09 Oct 1997) |