| AF | abnormal frequency; acid-fast; adult female; afebrile; aflatoxin; albumin-free; albumose-free; aldeh... |
|---|---|
| AFB | acid-fast bacillus; aflatoxin B; air fluidized bed; aortofemoral bypass |
| CFR | case-fatality ratio; citrovorum-factor rescue; Code of Federal Regulations; complement-fixation reac... |
| FAB | fast atom bombardment; formalin ammonium bromide; fragment, antigen-binding [of immunoglobulins]; Fr... |
| FAST | flow-assisted, short-term [balloon catheter]; fluorescent antibody staining technique; fluoro-allerg... |
| fast neutrons | Neutrons, the energy of which exceeds some arbitrary level, usually around one million electron volts. (12 Dec 1998) |
|---|---|
| fast pyrolysis | Thermal conversion of biomass by rapid heating to between 450> To 600>C in the absence of oxygen. (05 Dec 1998) |
| fast smear | A cytologic smear containing material from the vaginal pool and pancervical scrapings, mixed and prepared on one microscopic slide, smeared, and fixed immediately; used principally for routine screening of ovaries, endometrium, cervix, vagina, and hormonal states. (05 Mar 2000) |
| Kluver-Barrera Luxol fast blue stain | <technique> In combination with cresyl violet, a stain useful for demonstrating myelin and Nissl substance. (05 Mar 2000) |
| liquid-metal fast-breeder reactor | <physics> Fission breeder reactor concept using liquid-metal coolant and breeding additional fuel off fast neutrons. See: breeder reactor. (09 Oct 1997) |
| Luxol fast blue | Name for a group of closely related copper phthalocyanin dyes used as stains (with PAS, PTAH, haematoxylin, silver nitrate, etc.) for myelin in nerve fibres. (05 Mar 2000) |
| actinic ray | A light ray toward and beyond the violet end of the spectrum that acts upon a photographic plate and produces other chemical effects. Synonym: chemical ray. (05 Mar 2000) |
| alpha ray | <physics> A radioactive particle made up of two protons and two neutrons, these particles are created by the decay of a radioactive material or by nuclear bombardment, and they are the same as the nucleus of a helium-4 atom. (09 Oct 1997) |
| ap, X-ray | An X-ray picture in which the beams pass from front-to-back (anteroposterior). As opposed to a PA (posteroanterior) film in which the rays pass through the body from back-to-front. (12 Dec 1998) |
| beta ray | 1. <radiobiology> Original term used for electrons (and positrons) ejected from decaying nuclei via beta emission. (Label derives from the old days when we had various kinds of radiation emission, and they were labelled alpha, beta, and gamma (the first letters of the Greek Alphabet) because no one really knew what any of them were.) 2. A stream of positive or negative electrons ejected with high energy from a disintegrating atomic nucleus; most biomedically used isotopes emit negative particles (electrons or negatrons, rather than positrons). Cathode rays are low-energy negative electrons produced in cathode ray tubes, also called television tubes or oscilloscopes. (12 Sep 2000) |
| gamma ray | <radiobiology> Electromagnetic radiation (photons) with energies greater than (roughly) 100 keV (that is, 100,000 electron volts). Gamma radiation frequently accompanies alpha and beta decays, and always accompanies fission. Gamma rays are highly penetrating and are best shielded against using dense materials, such as lead or depleted uranium. (Gamma rays are similar to X-rays, but are generally higher in energy and nuclear in origin.) Gamma rays have wavelengths of 1 nanometre or shorter. These are highly energised, deeply penetrating photons which can be emitted from an atomic nucleus during nuclear fission (the splitting of an atom) and during regular atomic decay (radioactivity). (13 Oct 1997) |
| gamma ray knife | A beam of high energy X-rays. See: radiosurgery. (05 Mar 2000) |
| panoramic X-ray | <dentistry> An X-ray taken by a machine that rotates around your head to give the orthodontist a picture of your teeth, jaws and other important information. (08 Jan 1998) |
| panoramic X-ray film | In dentistry, a radiograph taken to give a panoramic view of the entire upper and lower dental arch as well as the temporomandibular joints. (05 Mar 2000) |
| ray | <botany> A zygomorphic flower in the family Asteraceae, a radial band of cells traversing the conducting elements in woody stems. Of a compound umbel, one of the first (lower) series of branches of the inflorescence main stem. (09 Oct 1997) |