| MRA | magnetic resonance angiography; main renal artery; marrow repopulation activity; medical record anal... |
|---|---|
| a.t. | acquisition time; 영상회복시간 = TR x N x Nex TR; Time to Repeat &... |
| VDRE | Vitamin D Responsive Element |
| ACSE | association control service element |
| BEP | brain evoked potential; basic element of performance |
| neutral element | An element of the zero group of the periodic system comprising the rare gases, He, Ne, Ar, Kr, Xe, Rn. Synonym: noble element. (05 Mar 2000) |
|---|---|
| noble element | A metal that cannot be oxidised by heat alone, nor readily dissolved by acid; e.g., gold, platinum. Synonym: noble element. (05 Mar 2000) |
| dyad symmetry element | Dyad symmetry element bound by serum response factor to control the expression of c fos. (18 Nov 1997) |
| Is element | Mobile nucleotide sequences that occur naturally in the genomes of bacterial populations. When inserted into bacterial DNA, they inactivate the gene concerned, when they are removed the gene regains its activity. Closely related to transposons and range in size from a few hundred to a few thousand bases, but are usually less than 1500 bases. (18 Nov 1997) |
| electronegative element | An element whose atoms have a tendency to accept electrons and form negative ions (e.g., oxygen, sulfur, chlorine, etc.). (05 Mar 2000) |
| electropositive element | <chemistry> An element whose atoms have a tendency to lose electrons and form positive ions (e.g., sodium). (05 Mar 2000) |
| element | <chemistry> One of the 103 known chemical substances that cannot be divided into simpler substances by chemical means. A substance whose atoms all have the same atomic number. Examples: hydrogen, lead, uranium.(See atom, matter, nuclide.) (16 Dec 1997) |
| trace element | Any chemical element that an organism needs very small quantities of tosurvive. (09 Oct 1997) |
| transitional element | <cell biology> Region at the boundary of the rough endoplasmic reticulum and the Golgi. Transport vesicles are responsible for the transfer of secretory proteins from this part of the rough endoplasmic reticulum to the Golgi system. (18 Nov 1997) |
| enhancer element | <molecular biology> A DNA sequence, present in the genomes of higher eukaryotes and of various animal viruses, which can increase the transcription of genes into messenger RNA. These control element frequently found 5' to the start site of a gene, when bound by a specific transcription factor, enhance the levels of expression of the gene, but are not sufficient alone to cause expression. Distinguished from a promoter, that is alone sufficient to cause expression of the gene when bound, in practice, the two terms merge. Enhancers usually can function in either orientation and at various distances from a promoter. Compare: promoter. (03 Jul 1999) |
| transposable element | <molecular biology> Small, mobile DNA sequences that can replicate and insert copies at random sites within chromosomes. They have nearly identical sequences at each end, oppositely oriented (inverted) repeats and code for the enzyme, transposase, that catalyses their insertion. Bacteria have two types of transposon, simple transposons that have only the genes needed for insertion and complex transposons that contain genes in addition to those needed for insertion. Eukaryotes contain two classes of mobile genetic elements, the first are like bacterial transposons in that DNA sequences move directly. The second class (retrotransposons) move by producing RNA that is transcribed, by reverse transcriptase, into DNA which is then inserted at a new site. (13 Nov 1997) |
| extrachromosomal element | Any heritable element not associated with the chromosome. It is usually a plasmid or the DNA of organelles such as mitochondria and chloroplasts. (18 Nov 1997) |
| accumulation analysis | A technique in which an intermediate of a metabolic pathway accumulates due to selective inhibition of a particular step in that pathway or in a mutant that is deficient in a certain step. The intermediate is then isolated, analyzed, and identified. (05 Mar 2000) |
| activation analysis | <radiobiology> Method for identifying and measuring chemical elements in a sample of material. Sample is first made radioactive by bombardment with neutrons, charged particles, or gamma rays. Newly formed radioactive atoms in the sample then give off characteristic radiations (such as gamma rays) that tell what kinds of atoms are present, and how many. (09 Oct 1997) |
| actuarial analysis | The application of probability and statistical methods to calculate the risk of occurrence of any event, such as onset of illness, recurrent disease, hospitalization, disability, or death. It may include calculation of the anticipated money costs of such events and of the premiums necessary to provide for payment of such costs. (12 Dec 1998) |