| sulfur group | The elements sulfur, selenium, and tellurium; they form dibasic acids with hydrogen, and their oxyacids are also dibasic. (05 Mar 2000) |
|---|---|
| sulfur group transferases | <enzyme> Enzymes that catalyze the transfer of sulfur atoms (2.8.1), sulfur groups (2.8.2) or coenzyme a (2.8.3). Registry number: EC 2.8 (12 Dec 1998) |
| symptom group | See: syndrome, complex. (05 Mar 2000) |
| synechococcus group | Unicellular, coccoid to rod-shaped cyanobacteria that divide by binary fission in a single plane. Their cells lack structured sheaths and range in diameter from 0.3 to 2.3 microns. These organisms are isolated from freshwater, marine, and hot spring environments. By examining morphological, physiological, and chemical properties it has been possible to subdivide this group into six "strain clusters". These clusters are equivalent to genera but have not been formalised. (12 Dec 1998) |
| synechocystis group | Unicellular cyanobacteria that divide by binary fission in two or three successive planes at right angles to one another. Typically, the cells occur singly or in pairs. These organisms are isolated from freshwater and seawater environments. By examining morphological, physiological, and chemical properties it has been possible to subdivide this group into four "strain clusters". These clusters are equivalent to genera but have not been formalised. (12 Dec 1998) |
| determinant group | That part of an antigenic molecule against which a particular immune response is directed. For instance a tetra to penta peptide sequence in a protein, a tri to penta glycoside sequence in a polysaccharide. In the animal most antigens will present several or even many antigenic determinants simultaneously. See: hapten. (18 Nov 1997) |
| diagnosis-related group | A classification of patients by diagnosis or surgical procedure (sometimes including age) into major diagnostic categories (each containing specific diseases, disorders, or procedures) for the purpose of determining payment of hospitalization charges, based on the premise that treatment of similar medical diagnoses generate similar costs. A scheme for billing for medical and especially hospital services by combining diseases into groups according to the resources needed for care, arranged by diagnostic category. A dollar value is assigned to each group as the basis of payment for all cases in that group, without regard to the actual cost of care or duration of hospitalization of any individual case, as a mechanism to motivate health-care providers to economise. (05 Mar 2000) |
| difarnesyl group | A 30-carbon open chain hexaisoprenoid hydrocarbon radical; occurs as a side chain in vitamin K2. (05 Mar 2000) |
| Dombrock blood group | See Blood Groups appendix. (05 Mar 2000) |
| duffy blood-group system | A blood group consisting mainly of the antigens fy(a) and fy(b), determined by allelic genes, the frequency of which varies profoundly in different races; amorphic genes are common. (12 Dec 1998) |
| I blood-group system | A blood group related both to the abo and p systems that includes several different antigens found in most people on erythrocytes, in milk, and in saliva. The antibodies react only at low temperatures. (12 Dec 1998) |
| quebec group | <geology> The middle of the three groups into which the rocks of the Canadian period have been divided in the American Lower Silurian system. Source: Websters Dictionary (01 Mar 1998) |
| one-carbon group transferases | <enzyme> A subclass of transferases that transfer chemical groups containing a single carbon. These include the methyltransferases, the hydroxymethyl and formyl transferases, the carboxyl and carbamoyl transferases, and the amidinotransferases. Registry number: EC 2.1 (12 Dec 1998) |
| taxonomic group | <zoology> A taxon with all its subordinate taxa and their individuals, for example the taxonomic group Insecta consists of all insects and their taxa. (09 Jan 1998) |
| T group | <abbreviation> Training group. (05 Mar 2000) |