| 131I | radioactive Iodine(used in Thyroid uptake, Liver & Kidney Scans & Treatment of malignant & nonmalig... |
|---|---|
| 99mTc | radioactive Technetium(used in Brain Skull, Thyroid, Liver, Spleen, Bone & Lung scans) |
| RA | radioactive; ragocyte; ragweed antigen; rapidly adapting [receptors]; reactive arthritis; reciprocal... |
| RAIU | radioactive iodine uptake |
| RAMP | radioactive antigen microprecipitin; right atrial mean pressure |
| HWE | Hardy-Weinberg Equilibrium |
|---|---|
| OEC | Oxygen equilibrium curves |
| ENa | equilibrium potential |
| E(K) | equilibrium potential for K |
| equilibrium constant | <chemistry> The ratio of the reverse and forward rate constants for a reaction of the type: A + B = AB at equilibrium the equilibrium constant (K) equals the product of the concentrations of reactants divided by the concentration of product and has dimensions of concentration. Kd = (concentration A.concentration B) / (concentration AB). The affinity constant (Ka) is the reciprocal of the equilibrium constant. Dimension: moles per litre. In general the concept of Kd is more readily understood than that of Ka, for example: in considering the conversion of A to AB by the binding of ligand B, the Kd = B when A = AB. Thus Kd is equal to the ligand concentration which produces half maximal conversion (response). (10 Jan 1998) |
|---|---|
| equilibrium dialysis | In immunology, a method for determination of association constants for hapten-antibody reactions in a system in which the hapten (dialyzable) and antibody (nondialyzable) solutions are separated by semipermeable membranes. Since at equilibrium the quantity of free hapten will be the same in the two compartments, quantitative determinations can be made of hapten-bound antibody, free antibody, and free hapten. (05 Mar 2000) |
| equilibrium potential | <physiology> The membrane potential at which a particular type of ion or other particle does not diffuse through the membrane in either direction. (09 Oct 1997) |
| linkage equilibrium | <genetics> Situation that should exist in a population undisturbed by selection, migration, etc., in which all possible combinations of linked genes should be present at equal frequency. The situation is no more common than are such undisturbed populations. (18 Nov 1997) |
| air pollutants, radioactive | Pollutants, present in air, which exhibit radioactivity. (12 Dec 1998) |
| radioactive | Giving off radiation. (12 Dec 1998) |
| radioactive atom | <chemistry, physics> An atom with an unstable nucleus, which emits particulate or electromagnetic radiation (radioactive emission) to achieve greater stability. See: radionuclide, half-life, Becquerel. (05 Mar 2000) |
| radioactive constant | <physics, radiobiology> The fraction of the amount of a radionuclide that undergoes transition per unit time. Formally: Lamda=dP/dt Where dP is the probability of a given nucleus undergoing spontaneous nuclear transition in the time interval dt. (16 Dec 1997) |
| radioactive contamination | <radiobiology> Radioactive substance dispersed in material or places where it is undesirable. (16 Dec 1997) |
| radioactive cow | Colloquialism for radionuclide generator. See: cow. (05 Mar 2000) |
| radioactive decay | <physics> The process by which a spontaneous change in nuclear state takes place. This process is accompanied by the emission of energy in various specific combinations of electromagnetic and corpuscular radiation and neutrinos. (16 Dec 1997) |
| radioactive fallout | The material that descends to the earth or water well beyond the site of a surface or subsurface nuclear explosion. (12 Dec 1998) |
| radioactive iodide uptake test | A test of thyroid function in which 131I-iodide is given orally; after 24 hours, the amount present in the thyroid gland is measured and compared with normal values. Synonym: radioactive iodide uptake test, RAI test. (05 Mar 2000) |
| radioactive iodine | Iodine that gives off radiation. See radioiodine. (12 Dec 1998) |
| radioactive isotope | <physics, radiobiology> An isotope of an element that has an unstable nucleus, it tries to stabilise itself by giving off ionising radiation. (09 Oct 1997) |