| ARRS | American Roentgen Ray Society |
|---|---|
| AXF | advanced x-ray facility |
| AXR | abdominal x-ray [examination] |
| BREASTS | bronchopulmonary aspergillosis, radiotherapy, extrinsic allergic alveolitis, ankylosing spondylitis,... |
| CR | calculation rate; calculus removed; calorie-restricted; cardiac rehabilitation; cardiac resuscitatio... |
| polar plates | Condensed platelike bodies at the ends of the spindle during mitosis of certain types of cells. (05 Mar 2000) |
|---|---|
| polar presentation | The presentation of either pole of the foetal oval; may be either a cephalic or breech presentation, or a longitudinal lie. (05 Mar 2000) |
| polar ring | A thickened, electron-dense ring at the anterior end of certain stages of the Apicomplexa; part of the apical complex characteristic of these sporozoans. (05 Mar 2000) |
| polar solvents | Solvent's that exhibit polar forces on solutes, due to high dipole moment, wide separation of charges, or tight association; e.g., water, alcohols, acids. (05 Mar 2000) |
| polar star | One of the figures forming the diaster. Synonym: polar star. (05 Mar 2000) |
| polar zone | The region in the vicinity of an electrode applied to the body. See: electrotonus. (05 Mar 2000) |
| electro-polar | <physics> Possessing electrical polarity; positively electrified at one end, or on one surface, and negatively at the other; said of a conductor. Source: Websters Dictionary (01 Mar 1998) |
| zinco-polar | <physics> Electrically polarized like the surface of the zinc presented to the acid in a battery, which has zincous affinity. Source: Websters Dictionary (01 Mar 1998) |
| law of polar excitation | A given segment of a nerve is irritated by the development of catelectrotonus and the disappearance of anelectrotonus, but the reverse does not hold; i.e., excitation occurs at the cathode when the circuit is closed and at the anode when it is opened. Synonym: Pfluger's law. (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) |