| alpha channeling | <radiobiology> Term for an idea (so far theoretical) in magnetic confinement fusion, the idea is that plasma waves can be used to control the alpha particles produced in a fusion reactor, to transfer their energy directly to fuel ions, and to help push them out of the plasma. This could potentially help to substantially improve the power output capabilities of fusion plasmas. (09 Oct 1997) |
|---|---|
| alpha-chloralose | A conjugate of chloral and glucose used as an anaesthetic in laboratory animals; it does not depress cardiovascular reflexes as much as most other anaesthetic agents. (05 Mar 2000) |
| alpha-chlorohydrin | <chemical> 3-chloro-1,2-propanediol. A chlorinated propanediol compound that has shown anti-fertility activity in males and has been used as a chemosterilant in rodents. Pharmacological action: chemosterilants, contraceptive agents, male. Chemical name: 1,2-Propanediol, 3-chloro- (12 Dec 1998) |
| alpha-chymotrypsin-induced glaucoma | Transient secondary glaucoma following the use of alpha-chymotrypsin in cataract extraction. (05 Mar 2000) |
| alpha-cortol | 5b-Pregnane-3a,11b,17,20a,21-pentaol; the 5b enantiomer of alpha-allocortol;a reduction product of cortisone, present in the urine, differing from cortisone in that the three keto groups are reduced to hydroxyls. (05 Mar 2000) |
| alpha-cortolone | 3a,17a,20a,21-Tetrahydroxy-5b-pregnane-11-one;the 5b enantiomer of alpha-allocortolone; a reduction product of cortisone, present in the urine, differing from cortisone in that two of the keto groups (at positions 3 and 20) are reduced to hydroxyls. (05 Mar 2000) |
| alpha-d-galactosidase | <enzyme> An enzyme catalyzing the hydrolysis of alpha-d-galactosides to release free d-galactose. A deficiency of type A alpha-d-galactosidase is associated with Fabry's disease. Synonym: melibiase. (05 Mar 2000) |
| alpha-d-glucosidase | A glucohydrolase removing terminal nonreducing 1,4-linked alpha-glucose residues by hydrolysis, yielding alpha-glucose; a deficiency of the lysosomal enzyme is associated with glycogen storage disease type II. There are at least five isozymes of maltase. Synonym: glucoinvertase. (05 Mar 2000) |
| alpha-D-mannose-beta-1,2-N-acetylglucosaminyltransferase | <enzyme> Absolute specificity for terminal branched mannosyl residues of glycolipids Registry number: EC 2.4.1.- Synonym: udpgnac-1,2-magtransferase (26 Jun 1999) |
| alpha-D-xylosidase | <enzyme> Highly specific for 4-nitrophenyl alpha-d-xylopyranoside and isoprimeverose; can also split off the alpha-d-xylopyranosyl residue on the non-reducing terminal of the backbone of certain oligoxyloglucans Registry number: EC 3.2.1.- Synonym: alpha-d-xylosidase I, alpha-d-xylosidase II (26 Jun 1999) |
| alpha emission | <physics> Form of nuclear decay where the nucleus emits an alpha particle (see entry below). (09 Oct 1997) |
| alpha-endorphin | <chemical> An endogenous opioid peptide derived from the pro-opiomelanocortin precursor. It differs from gamma-endorphin by one amino acid. Chemical name: alpha-Endorphin (12 Dec 1998) |
| alpha error | The statistical error (said to be of the first kind or type I) made in testing an hypothesis when it is concluded that a result is positive when it really is not. Alpha error is often referred to as a false positive. (12 Dec 1998) |
| alpha-farnesene | 3,7,11-Trimethyl-1,3,6,10-dodecatetraene;a straight open-chain hydrocarbon built up of three isoprene units; one of the four isomeric forms occurs in the natural coating of apples. (05 Mar 2000) |
| alpha-fetoprotein | <protein, tumour marker> A protein substance that is normally produced by the liver cells. It is one of the first alpha-globulins to appear in mammalian sera during development of the embryo and the dominant serum proteins in early embryonic life. They reappear in the adult serum during certain pathologic states. Measurement of the alpha-fetoprotein level in the bloodstream has been used as a early detection test for some forms of cancer (hepatocellular carcinoma). Alpha-fetoprotein can also be an important marker in the fluid obtained by amniocentesis for the prenatal diagnosis of anencephaly and other open neural tube defects such as spina bifida. Elevated in: wrong dates for a pregnancy, multiple gestation, midline closure (neural-tube) defects, encephalocele, anencephaly, liver tumours, hepatoblastoma, haemangioendothelioma (occasionally, mild), hepatocellular carcinoma (HCC, hepatoma). The level produced by liver tumours (hepatomas), germ cell tumours (teratocarcinoma and embryonal cell carcinomas) permits the monitoring of response to treatment of these tumours. Decreased in: wrong dates for a pregnancy, chromosome abnormality (including Down syndrome) Acronym: AFP (27 Jun 1999) |