| kerma | <physics> The sum of the initial kinetic energies of all the charged ionising particle liberated by uncharged ionising particles per unit mass of a specified material. Kerma is measured in the same unit as absorbed dose. The SI unit of kerma is joule per kilogram and its special name is the gray (Gy). Kerma can be quoted for any specified material at a point in free space or in an absorbing medium. (13 Nov 1997) |
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| boron neutron capture therapy | A technique for the treatment of neoplasms, especially gliomas and melanomas in which boron-10, an isotope, is introduced into the target cells followed by irradiation with thermal neutrons. (12 Dec 1998) |
| neutron | <physics> An elementary atomic particle that has no charge and a mass that is approximately the same as that of a proton. Neutrons are found in allatoms except the lightest isotopes of hydrogen. (09 Jan 1998) |
| neutron activation analysis | Activation analysis in which the specimen is bombarded with neutrons. Identification is made by measuring the resulting radioisotopes. (12 Dec 1998) |
| neutron capture therapy | A technique for the treatment of neoplasms in which an isotope is introduced into target cells followed by irradiation with thermal neutrons. (12 Dec 1998) |
| neutron radiation | An emission of neutrons from the nucleus of an atom by decay or fission. (05 Mar 2000) |
| integrated neutron flux | <radiobiology> Sum (integral) of the neutron flux (neutrons per unit time per unit area, see flux) over all time, total number of neutrons which passed through a unit area. Important figure-of-merit in testing effects of neutron radiation on materials, and in assessing how long such materials can survive exposure to neutron sources (such as fission reactor cores and D-T fusion plasmas). (09 Oct 1997) |
| thermal neutron | <radiobiology> A neutron in thermal equilibrium with its surrounding environment. Thermal neutrons are those that have been slowed down by a moderator to speeds characteristic of the local temperature. Compare: fast neutron. (09 Oct 1997) |
| fast neutron | <physics> Neutron with energy greater than roughly 100,000 electron volts (100 keV). Distinguished from slow or thermal neutrons. (09 Oct 1997) |
| accelerator factor | <chemical> Heat- and storage-labile plasma glycoprotein which accelerates the conversion of prothrombin to thrombin in blood coagulation. Factor v accomplishes this by forming a complex with factor xa, phospholipid, and calcium (prothrombinase complex). Deficiency of factor v leads to owren's disease. Chemical name: Blood-coagulation factor V (12 Dec 1998) |
| acetate replacement factor | <biochemistry> 1,2 dithiolane 3 valeric acid. Regarded as a coenzyme in the oxoglutarate dehydrogenase complex of the citric acid cycle. Involved generally in oxidative decarboxylations of _ keto acids. A growth factor for some organisms. (18 Nov 1997) |
| adrenal weight factor | A postulated substance of adenohypophysial origin responsible for maintenance of the weight of the adrenal cortex. (05 Mar 2000) |
| adrenocorticotropic releasing factor | Hormone produced by hypothalamus that causes pituitary to secrete adrenocorticotropic hormone. (05 Mar 2000) |
| a-factor | <molecular biology> A protein which is found in the bacterial genus Streptomyces that helps start the production of streptomycin and the process of morphological differentiation. It is used in biotechnology to induce these functions in mutant strains of Streptomyces that cannot produce it themselves. (09 Feb 1998) |
| angiogenesis factor | Substance causing proliferation of new blood vessels. It is found in tissues with high metabolic requirements, such as the retina, and in certain cancers. The factor is also released by hypoxic macrophages at the edges or outer surfaces of wounds and initiates revascularization in wound healing. (12 Dec 1998) |