fraction

1. The quotient of two quantities. 2. An aliquot portion or any portion. 3. As a verb, to separate into portions.

- amorphous f. of adrenal cortex noncrystalline residue of an acetone extract of the adrenal cortex after crystalline steroids, e.g., corticosterone, deoxycorticosterone, etc., have been isolated.

- blood plasma fractions portions of the blood plasma as separated by electrophoresis or other technique.

- f. collector a device used to collect the eluate from a column in column chromatography.

- dried human plasma protein f. freeze-dried human plasma protein f..

- ejection f. the f. of the blood contained in the ventricle at the end of diastole that is expelled during its contraction, i.e., the stroke volume divided by end-diastolic volume, normally 0.55 (by electrocardiogram) or greater; with the onset of congestive heart failure, the ejection f. decreases, sometimes to 0.10 or even less in severe cases.

- filtration f. (FF) the f. of the plasma entering the kidney that filters into the lumen of the renal tubules, determined by dividing the glomerular filtration rate by the renal plasma flow; normally, it is around 0.17.

- human antihemophilic f. SYN: human antihemophilic factor.

- human plasma protein f. a sterile solution of selected proteins derived from the blood plasma of adult human donors, containing 4.5 to 5.5 g of protein per 100 ml, of which 83 to 90% is albumin and the remainder is α- and β-globulins; used as a blood volume supporter.

- mole f. the ratio of the moles of one component of a system to the total moles of all the components present.

- radionuclide ejection f. a nuclear medicine study for determination of ejection f. of either ventricle; supersedes multiple-gated acquisition scan in some centers. SEE ALSO: multiple-gated acquisition scan.

- recombination f. the proportion of progeny of a mating pair of specific genotype and coupling phase that are recombinant; there must be no differential selection among the possible types of progeny, and the recombination f. should be the same regardless of the alleles involved or their coupling phase.

- regurgitant f. the amount of blood regurgitated into a cardiac chamber divided by the stroke output; normally, no blood regurgitates; in patients with severe valvular lesions such as mitral or aortic insufficiency, regurgitant f. can approach 80%; this f. affords a quantitative measure of the severity of the valvular lesion.

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frac·tion 'frak-shən n one of several portions (as of a distillate) separable by fractionation <gamma globulin is a \fraction of blood plasma>

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frac·tion (frakґshən) 1. a portion of something larger; see also fractionation and fractional dose, under dose. 2. in chemistry, one of the separable constituents of a substance.