| EF | ectopic focus; edema factor; ejection fraction; elastic fibril; electric field; elongation factor; e... |
|---|---|
| ERHD | exposure-related hypothermic death |
| ex | exacerbation; examination, examined, examiner; example; excision; exercise; exophthalmos; exposure; ... |
| exp | expansion; expectorant; experiment, experimental; expiration, expired; exponential function; exposur... |
| FSE | fast spin echo; filtered smoke exposure |
| time constant | That part of a circuit that determines the time interval over which the rate of electrical events will be averaged; in pulmonary physiology, the factors determining rate of flow in the airways. (05 Mar 2000) |
|---|---|
| transformation 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) |
| 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) |
| universal gas constant | <radiobiology> R = 8.314 x 10^7 ergs per degree C per mole. (09 Oct 1997) |
| flotation constant | Characteristic sedimentation behaviour of a lipoprotein fraction of plasma in a centrifugal field in a medium of appropriate density, achieved by adding a salt or D2O to the plasma. Synonym: negative S, Svedberg of flotation. (05 Mar 2000) |
| law of constant numbers in ovulation | The number of ova discharged at each ovulation is nearly constant for any given species. (05 Mar 2000) |
| abortion rate | The number of abortions per 1000 terminated pregnancies during a given period of time. (05 Mar 2000) |
| age-specific rate | A rate for a specified age group, in which the numerator and denominator refer to the same age group. (05 Mar 2000) |
| attack rate | A cumulative incidence rate used for particular groups observed for limited periods under special circumstances, such as during an epidemic. (05 Mar 2000) |
| average flow rate | <physiology> The flow rate determined by dividing the total volume passed in a time period divided by the time period, usually quoted in mls per minute. (05 Mar 2000) |
| backup rate | A utility charge for providing occasional electricity service to replace on-site generation. (05 Dec 1998) |
| basal metabolic rate | <biochemistry, biology> The metabolic rate as measured under basal conditions: 12 hours after eating, after a restful sleep, no exercise or activity preceding test, elimination of emotional excitement and occurring in a comfortable temperature. Acronym: BMR (15 Nov 1997) |
| baseline foetal heart rate | <paediatrics> The average heart rate for a particular foetus during the diastolic phase of uterine contractions. (05 Mar 2000) |
| baseline variability of foetal heart rate | The beat-to-beat changes in foetal heart rate as recorded on a graph. (05 Mar 2000) |
| basic reproductive rate, ratio | <epidemiology> See Reproductive Ratio. (05 Dec 1998) |