| GRF | gastrin-releasing factor; genetically related macrophage factor; gonadotropin-releasing factor; grow... |
|---|---|
| HSF | heat shock factor; hepatocyte stimulatory factor; histamine sensitizing factor; human serum esterase... |
| LPF | leukocytosis-promoting factor; leukopenia factor; lipopolysaccharide factor; localized plaque format... |
| MIF | macrophage inhibitory factor; melanocyte[-stimulating hormone]-inhibiting factor; maximum inspirator... |
| MRF | Markov random field; medical record file; melanocyte-[stimulating hormone]-releasing factor; mesence... |
one and one-half syndrome
| enamel cleavage | The splitting of enamel in a plane parallel to the direction of the enamel rods. (05 Mar 2000) |
|---|---|
| equal cleavage | Cleavage producing blastomeres of like size. (05 Mar 2000) |
| equatorial cleavage | Cleavage in which the plane of cytoplasmic division is at right angles to the axis of the ovum. (05 Mar 2000) |
| yolk cleavage | Segmentation of the vitellus. (05 Mar 2000) |
| unequal cleavage | Cleavage producing blastomeres of different sizes at the two poles. (05 Mar 2000) |
| freeze cleavage | Method of specimen preparation for the electron microscope in which rapidly frozen tissue is cracked so as to produce a fracture plane through the specimen. The surface of the fracture plane is then shadowed by heavy metal vapour, strengthened by a carbon film and the underlying specimen is digested away, leaving a replica that can be picked up on a grid and examined in the transmission electron microscope. The great advantage of the method is that the fracture plane tends to pass along the centre of lipid bilayers and it is therefore possible to get en face views of membranes that reveal the pattern of Integral membrane proteins. The E face is the outer lamella of the plasma membrane viewed as if from within the cell, the P face the inner lamella viewed from outside the cell. Fracture planes also often pass along lines of weakness such as the interface between cytoplasm and membrane, so that outer and inner membrane surfaces can be viewed. Further information about the structure can be revealed by freeze etching. Extremely rapid freezing followed by deep etching has allowed the structure of the cytoplasm to be studied without the artefacts that might be introduced by fixation. (18 Nov 1997) |
| abstracting and indexing | Shortening or summarizing of documents; assigning of descriptors for referencing documents. (12 Dec 1998) |
| academies and institutes | Organizations representing specialised fields which are accepted as authoritative; may be non-governmental, university or an independent research organization, e.g., national academy of sciences, brookings institution, etc. (12 Dec 1998) |
| accounts payable and receivable | Short-term debt obligations and assets occurring in the regular course of operational transactions. (12 Dec 1998) |
| aged, 80 and over | A person 80 years of age and older. (12 Dec 1998) |
| algae and fungi | Algae represent a group of spore-propagating plants, unicellular or undifferentiated into root, stem, and leaf. They include seaweed and many unicellular fresh water plants, most of which contain chlorophyll. They account for about 90% of the earth's photosynthetic activity. Fungi are eukaryotic, heterotrophic organisms that live as saprobes or parasites and include mushrooms, yeasts, smuts, molds, etc. They lack chlorophyll. (12 Dec 1998) |
| alkyl and aryl transferases | <enzyme> A somewhat heterogeneous class of enzymes that catalyze the transfer of alkyl or related groups (excluding methyl groups). Registry number: EC 2.5 (12 Dec 1998) |
| allergy and immunology | A medical specialty concerned with the hypersensitivity of the individual to foreign substances and protection from the resultant infection or disorder. (12 Dec 1998) |
| alligators and crocodiles | Large, long-tailed reptiles, including caimans, of the order loricata. (12 Dec 1998) |
| Amine Precursor Uptake and Decarboxylation | <pharmacology, physiology> Paracrine cells of which argentaffin cells are an example. Usage of the term APUD is neither helpful nor memorable. Acronym: APUD (11 Nov 1997) |