| electron resonance absorption | <physics> A spectrometric method, based on measurement of electron spins and magnetic moments, for detecting and estimating free radicals in reactions and in biological systems. Synonym: electron paramagnetic resonance. (05 Mar 2000) |
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| external absorption | The absorption of substances through skin, mucocutaneous surfaces, or mucous membranes. (05 Mar 2000) |
| fluorescent treponemal antibody-absorption test | <investigation> A sensitive and specific serologic test for syphilis. It is more specific than the VDRL assay. The patient's serum is diluted to remove non-specific antibodies and then mixed on a glass slide with Nichol's strain of Treponema pallidum. If antibodies are present in the patient's serum they bind to the antigen and the bound antibodies are detected with fluoresceinated antihuman gamma-globulin antibody. Synonym: FTA-ABS test. (12 Sep2002) |
| activity coefficient | <chemistry> The factor by which the value of a concentration of a solute must be multiplied to determine its true thermodynamic activity. (06 May 1997) |
| attenuation coefficient | 1. <radiobiology> Compton: The fractional number of photons removed from a beam of radiation per unit thickness of material through which it is passing as a result of Compton effect interactions. 2. Linear: The fractional number of photons removed from a beam of radiation per unit thickness of material through which it is passing due to all absorption and scattering processes. 3. Pair Production: That fractional decrease in the intensity of a beam of ionising radiation due to pair production in a medium through which it passes. 4. Photoelectric Effect: That fractional decrease in the intensity of a beam of ionising radiation due to photoelectric effect in a medium through which it passes. (16 Dec 1997) |
| biological coefficient | Rarely used term denoting the energy expended by the body at rest. (05 Mar 2000) |
| Bunsen's solubility coefficient | The milliliters of gas STPD dissolved per milliliter of liquid and per atmosphere (760 mm Hg) partial pressure of the gas at any given temperature. (05 Mar 2000) |
| velocity coefficient | The rate of transformation of a unit mass of substance in a chemical reaction. (05 Mar 2000) |
| recombination coefficient | <radiobiology> The rate of recombination of positive ions with electrons (or negative ions) in a gas, per unit volume, divided by the product of the particle densities of the two species (positive ions and electrons/negative ions) involved. (09 Oct 1997) |
| mass attenuation coefficient | <physics> The mass attenuation coefficient, u/p, of a material for uncharged ionising particles is the quotient of DN/N by pdl, where DN/N is the fraction of particles that experience interactions in traversing a distance dl in a material of density p. (16 Dec 1997) |
| reflection coefficient | A measure of the relative permeability of a particular membrane to a particular solute; calculated as the ratio of observed osmotic pressure to that calculated from van't Hoff's law; also equal to 1 minus the ratio of the effective pore areas available to solute and to solvent. (05 Mar 2000) |
| partition coefficient | <chemistry> Equilibrium constant for the partitioning of a molecule between hydrophobic (oil) and hydrophilic (water) phases. A measure of the affinity of the molecule for hydrophobic environments and thus, for example: a rough guide to the ease with which a molecule will cross the plasma membrane. (18 Nov 1997) |
| reliability coefficient | An index of the consistency of measurement often based on the correlation between scores obtained on the initial test and a retest (test-retest reliability) or between scores on two similar forms of the same test (equivalent-form reliability). (05 Mar 2000) |
| respiratory coefficient | <physiology> Molar ratio of carbon dioxide production to oxygen consumption. (18 Nov 1997) |
| Rideal-Walker coefficient | A figure expressing the disinfecting power of any substance; it is obtained by dividing the figure indicating the degree of dilution of the disinfectant that kills a microorganism in a given time by that indicating the degree of dilution of phenol which kills the organism in the same space of time under similar conditions. Synonym: hygienic laboratory coefficient, phenol coefficient. (05 Mar 2000) |