| noncondensing, controlled extraction turbine | A turbine that bleeds part of the main steam flow at one (single extraction) or two (double extraction) points. (05 Dec 1998) |
|---|---|
| tooth extraction | The surgical removal of a tooth. (12 Dec 1998) |
| total breech extraction | Delivery of a foetus in breech presentation with complete extraction of the entire foetal body from the uterus. (05 Mar 2000) |
| extraction | The process or act of pulling or drawing out. Origin: L. Trahere = to draw (18 Nov 1997) |
| extraction and processing industry | The industry concerned with the removal of raw materials from the earth's crust and with their conversion into refined products. (12 Dec 1998) |
| extraction coefficient | The percentage of a substance removed from the blood or plasma in a single passage through a tissue; e.g., the extraction coefficient for p-aminohippuric acid (PAH) in the kidney is the difference between arterial and renal venous plasma PAH concentrations, divided by the arterial plasma PAH concentration. (05 Mar 2000) |
| extraction, obstetrical | Extraction of the foetus by means of obstetrical instruments. (12 Dec 1998) |
| extraction ratio | The fraction of a substance removed from the blood flowing through the kidney; it is calculated from the formula (A -V)/A, where A and V, respectively, are the concentrations of the substance in arterial and renal venous plasma. (05 Mar 2000) |
| annular cataract | Congenital cataract in which a central white membrane replaces the nucleus. Synonym: disk-shaped cataract, life-belt cataract, umbilicated cataract. (05 Mar 2000) |
| arborescent cataract | An obsolete term for dendritic cataract. (05 Mar 2000) |
| atopic cataract | A cataract associated with atopic dermatitis. (05 Mar 2000) |
| axial cataract | A lenticular opacity in the visual axis of the lens. (05 Mar 2000) |
| black cataract | A cataract in which the lens is hardened and of a dark brown colour. In the 19th century, German black cataract meant gutta severa (q.v.). Synonym: cataracta brunescens, cataracta nigra. (05 Mar 2000) |
| blue cataract | Coronary cataract of bluish colour. Synonym: cataracta cerulea. (05 Mar 2000) |
| capsular cataract | A cataract in which the opacity affects the capsule only. (05 Mar 2000) |