| radioactive tracer | <physics, radiobiology> A radioisotope is an element which has the same atomic number as another but a different atomic weight, exhibiting the property of spontaneous decomposition. Decomposition gives off radiation (gamma rays) that can be detected with a counter. If a radioisotope is attached to a biological compound and injected into the body, its path may be traced through the body (resulting in an image). (27 Sep 1997) |
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| radioactive tracers | Radioactive substances added in minute amounts to the reacting elements or compounds in a chemical process and traced through the process by appropriate detection methods, e.g., geiger counter. Compounds containing tracers are often said to be tagged or labelled. (12 Dec 1998) |
| radioactive waste | <radiobiology> Equipment and materials from nuclear operations which are radioactive and for which there is no further anticipated use. Wastes are generally classified as high-level (having radioactivity concentrations of hundreds to thousands of curies per gallon or cubic foot), low-level (in the range of 1 microcurie per gallon or cubic foot), or intermediate (between high and low). See: curie. (09 Oct 1997) |
| radioactivity | <radiobiology> The quality of emitting or the emission of corpuscular or electromagnetic radiations consequent to nuclear disintegration, a natural property of all chemical elements of atomic number above 83 and possible of induction in all other known elements. (18 Nov 1997) |
| radioallergosorbent test | An allergy test done on a sample of blood. The aim with rast, as with skin tests, is to check for allergic sensitivity to specific substances. Rast stands for radioallergosorbent test. (12 Dec 1998) |
| radioautogram | Older term for autoradiograph. (05 Mar 2000) |
| radioautography | <technique> A specimen containing radioactive atoms is overlaid with a photographic emulsion (X-ray film), which is subsequently developed, revealing the localisation of radioactivity as a pattern of silver grains. Resolution is determined by the path length of the radiation and so the low energy beta emitting isotope, tritium, is usually used. The technique can be used to visualise radioactively labelled molecules or fragments of molecules, used in analyzing length and number of DNA fragments after they are separated by gel electrophoresis. (12 Mar 1998) |
| radiobicipital | Relating to the radius and the biceps muscle. (05 Mar 2000) |
| radiobicipital reflex | Contraction of the biceps muscle which sometimes occurs in the elicitation of the brachioradial reflex. (05 Mar 2000) |
| radiobiology | Study of the scientific principles, mechanisms, and effects of the interaction of ionizing radiation with living matter. (12 Dec 1998) |
| radiocalcium | A radioisotope of calcium, particularly calcium-45. (05 Mar 2000) |
| radiocarbon | A radioactive isotope of carbon; e.g., 14C. (05 Mar 2000) |
| radiocardiogram | A graphic record of the concentration of injected radioisotope within the cardiac chambers. (05 Mar 2000) |
| radiocardiography | The technique of recording or interpreting radiocardiograms. (05 Mar 2000) |
| radiocarpal | 1. Relating to the radius and the bones of the carpus. 2. On the radial or lateral side of the carpus. (05 Mar 2000) |