| diachronic study | A study done over the course of time. For example, a longitudinal study of children with Down syndrome (trisomy 21) might involve the study of 100 children with this condition from birth to 10 years of age. Also called a longitudinal study. The opposite of a synchronic (cross-sectional) study. (12 Dec 1998) |
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| epidemiologic study characteristics | Types and formulations of studies used in epidemiological and clinical research. (12 Dec 1998) |
| twin study | A method of detecting genetic causes in human traits and genetic factors in behaviour using sets of twins. (12 Dec 1998) |
| foetal doppler study | <radiology> Non-stress test (NST), external monitoring for 20 minutes; poor specificity, greater than4 foetal heart accelerations (greater than15 bpm over baseline for 15 seconds) following foetal movement in foetus greater than34 weeks, no heart accelerations in immaturity, sleep, maternal sedation contraction stress test (CST), external monitoring after oxytocin or maternal breast stimulation, greater than 3 uterine contraction in 10 minutes; 50% specificity uterine and umbilical artery waveform, elevated systolic:diastolic ratio = increased vascular resistance foetal aortic flow volume, 185-246 ml/kg/min see also: biophysical profile, intrauterine growth retardation (IUGR) (12 Dec 1998) |
| follow-up study | Study in which persons exposed to risk or given a designated preventive or therapeutic regimen are observed over a period or at intervals to determine the outcome of the exposure or regimen. (05 Mar 2000) |
| Framingham Heart study | <epidemiology> Ongoing epidemiologic study of a cohort of over 5,000 of the population of Framingham, MA conducted since 1949 under the auspices of the National Institutes of Health and Boston University. (05 Mar 2000) |
| longitudinal study | <epidemiology> A study taking place over time. If individuals are followed, this is a longitudinal cohort study. If individuals are not followed, but classes (usually age classes) are restudied, this is a longitudinal cross-sectional study. The converse of a horizontal study. (05 Dec 1998) |
| bufadienolides (two double bonds) | Bufatrienolides (three double bonds), etc; they have varying numbers of hydroxyl groups at positions 3, 5, 14, and 16, and these may be further substituted. For structure, see steroids. (05 Mar 2000) |
| bufenolides (one double bond) | (05 Mar 2000) |
| carbon-carbon double bond isomerases | <enzyme> Enzymes that catalyze the shifting of a carbon-carbon double bond from one position to another within the same molecule. Registry number: EC 5.3.3 (12 Dec 1998) |
| RNA, double-stranded | RNA consisting of two strands as opposed to the more prevalent single-stranded RNA. most of the double-stranded segments are formed from transcription of DNA by intramolecular base-pairing of inverted complementary sequences separated by a single-stranded loop. Some double-stranded segments of RNA are normal in all organisms. (12 Dec 1998) |
| conjugated double bonds | Two or more double bond separated by each single bond. (05 Mar 2000) |
| double | 1. To increase by adding an equal number, quantity, length, value, or the like; multiply by two; to double a sum of money; to double a number, or length. "Double six thousand, and then treble that." (Shak) 2. To make of two thicknesses or folds by turning or bending together in the middle; to fold one part upon another part of; as, to double the leaf of a book, and the like; to clinch, as the fist; often followed by up; as, to double up a sheet of paper or cloth. "Then the old man Was wroth, and doubled up his hands." (Tennyson) 3. To be the double of; to exceed by twofold; to contain or be worth twice as much as. "Thus reenforced, against the adverse fleet, Still doubling ours, brave Rupert leads the way." (Dryden) 4. To pass around or by; to march or sail round, so as to reverse the direction of motion. "Sailing along the coast, the doubled the promontory of Carthage." (Knolles) 5. To unite, as ranks or files, so as to form one from each two. Origin: OE. Doblen, dublen, doublen, F. Doubler, fr. L. Duplare, fr. Duplus. See Double. 1. Twice as much; twice the number, sum, quantity, length, value, and the like. "If the thief be found, let him pay double." (Ex. Xxii. 7) 2. Among compositors, a doublet (see Doublet. 2); among pressmen, a sheet that is twice pulled, and blurred. 3. That which is doubled over or together; a doubling; a plait; a fold. "Rolled up in sevenfold double Of plagues." (Marston) 4. A turn or circuit in running to escape pursues; hence, a trick; a shift; an artifice. "These men are too well acquainted with the chase to be flung off by any false steps or doubles." (Addison) 5. Something precisely equal or counterpart to another; a counterpart. Hence, a wraith. "My charming friend . . . Has, I am almost sure, a double, who preaches his afternoon sermons for him." (Atlantic Monthly) 6. A player or singer who prepares to take the part of another player in his absence; a substitute. 7. Double beer; strong beer. 8. A feast in which the antiphon is doubled, hat is, said twice, before and after the Psalms, instead of only half being said, as in simple feasts. 9. A game between two pairs of players; as, a first prize for doubles. 10. An old term for a variation, as in Bach's Suites. 1. Twofold; multiplied by two; increased by its equivalent; made twice as large or as much, etc. "Let a double portion of thy spirit be upon me." (2 Kings II. 9) "Darkness and tempest make a double night." (Dryden) 2. Being in pairs; presenting two of a kind, or two in a set together; coupled. "[Let] The swan, on still St. Mary's lake, Float double, swan and shadow." (Wordsworth) 3. Divided into two; acting two parts, one openly and the other secretly; equivocal; deceitful; insincere. "With a double heart do they speak." (Ps. Xii. 2) 4. <botany> Having the petals in a flower considerably increased beyond the natural number, usually as the result of cultivation and the expense of the stamens, or stamens and pistils. The white water lily and some other plants have their blossoms naturally double. Double is often used as the first part of a compound word, generally denoting two ways, or twice the number, quantity, force, etc, twofold, or having two. Double base, or Double bass . Same as Double-quick. Double window, a window having two sets of glazed sashes with an air space between them. Origin: OE. Doble, duble, double, OF. Doble, duble, double, F. Double, fr. L. Duplus, fr. The root of duo two, and perh. That of plenus full; akin to Gr. Double. See Two, and Full, and cf. Diploma, Duple. Source: Websters Dictionary (01 Mar 1998) |
| double antibody immunoassay | A method of separating antibody-bound antigen (e.g., insulin) from free antigen by precipitating the former with antibody specific for immunoglobulin. Synonym: double antibody immunoassay, double antibody method. (05 Mar 2000) |
| double antibody method | A method of separating antibody-bound antigen (e.g., insulin) from free antigen by precipitating the former with antibody specific for immunoglobulin. Synonym: double antibody immunoassay, double antibody method. (05 Mar 2000) |