| heterogeneous nuclear RNA | An ill-defined form of RNA, of high molecular weight, that never leaves the nucleus and is thought to be the precursor of messenger RNA. (05 Mar 2000) |
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| heterogenous nuclear RNA | <molecular biology> Originally identified as a class of RNA, found in the nucleus but not the nucleolus, which is rapidly labelled and with a very wide range of sizes, 2-40 kilobases. It represents the primary transcripts of RNA polymerase II and includes precursors of all messenger RNAs from which introns are removed by splicing. (18 Nov 1997) |
| small nuclear RNA | <molecular biology> A nucleic acid found in all living cells. Plays a role in transferring information from DNA to the protein-forming system of the cell. (16 Dec 1997) |
| nuclear | <cell biology> Of or pertaining to a nucleus; as, the nuclear spindle or the nuclear fibrils of a cell; the nuclear part of a comet, etc. Source: Websters Dictionary (01 Mar 1998) |
| Nuclear actin binding protein | <molecular biology> Nuclear protein, dimer of 34 kD subunits. Binds actin with Kd of around 25M. (18 Nov 1997) |
| nuclear atom | <physics, radiobiology> A concept or model of the atom characterised by the presence of a small, massive nucleus at its centre. (05 Mar 2000) |
| nuclear bag | <cell biology> The aggregation of nuclei occurring in the nonstriated centre of an intrafusal muscle fibre of a neuromuscular spindle. (05 Mar 2000) |
| nuclear bag fibre | The largest type of intrafusal muscle fibre's in a neuromuscular spindle, containing a central aggregation of nuclei (nuclear bag). (05 Mar 2000) |
| nuclear binding energy | <physics> The difference between the total energy (= mc^2) of the bound nucleus, and the energies of the individual constituent particles (= sum of masses c^2). The nuclear binding energy per nucleon is a maximum for iron. Fusion releases energy because light nuclei are less tightly bound than medium-weight nuclei, and thus energy is liberated when they become more tightly bound after fusing. Fission releases energy for the same reason - heavy nuclei are also less tightly bound than medium-weight nuclei, and energy is liberated when heavy nuclei split into lighter nuclei. (09 Oct 1997) |
| nuclear bone scan | A nuclear medicine test that involves the introduction of a radioactive compound into the blood stream. The radioactive compound acts as a tracer and allows for the imaging of the bony skeleton. (27 Sep 1997) |
| nuclear cardiology | <radiology> Myocardial infarct imaging (Tc-99m PYP), myocardial perfusion imaging (Tl-201), blood pool (MUGA), first-pass studies (12 Dec 1998) |
| nuclear cataract | A cataract involving the nucleus. Synonym: hard cataract. (05 Mar 2000) |
| nuclear chain fibre | The shortest and most numerous type of intrafusal muscle fibre's in a neuromuscular spindle, containing a single row of centrally positioned nuclei. (05 Mar 2000) |
| nuclear chemistry | The science concerned with the chemistry of nuclear reactions and processes. (05 Mar 2000) |
| nuclear-cytoplasmic ratio | Ratio of volume of nucleus to volume of cytoplasm, fairly constant for a particular cell type and usually increased in malignant neoplasms. (05 Mar 2000) |