| His' rule | The duration of pregnancy is calculated from the first day of the first omitted menstrual period; obsolete. (05 Mar 2000) |
|---|---|
| Huckel's rule | <chemistry> The number of depolarised electrons in an aromatic ring is equal to 4n + 2 where n is zero or any positive integer; l-tyrosine, l-phenylalanine, l-tryptophan, and l-histidine (when the imidazole ring is deprotonated) obey this rule. (05 Mar 2000) |
| Nagele's rule | Means of estimating date of delivery by counting back three months from the first day of the last menstrual period and adding seven days. (05 Mar 2000) |
| New Hampshire rule | Pioneering American test of criminal responsibility (1871): "if the [criminal] act was the offspring of insanity, a criminal intent did not produce it." (05 Mar 2000) |
| Durham rule | An American test of criminal responsibility (1954): "an accused is not criminally responsible if his unlawful act was the product of mental disease or mental defect." (05 Mar 2000) |
| isoprene rule | The classical, outmoded statement that naturally occurring terpenes are built up by condensation of isoprene units by either a 1-4 linkage ("head to tail") or a 4-4 linkage ("tail to tail"). (05 Mar 2000) |
| Ogino-Knaus rule | The time in the menstrual period when conception is most likely to occur is at about midway between two menstrual periods; fertilization of the ovum is least likely just before or just after menstruation; the basis for the rhythm method of contraception. (05 Mar 2000) |
| Trusler's rule for pulmonary artery banding | A method that gives guidance as to the correct tightness of the band; the degree of banding for a complex congenital cardiac anomaly with bidirectional shunting less than that for simple ones. (05 Mar 2000) |
| Jackson's rule | After an epileptic attack, simple and quasiautomatic functions are less affected and more rapidly recovered than the more complex ones. (05 Mar 2000) |
| Jordan's rule | <genetics> An evolutionary rule that states that the closest genetic relatives of a given species are found very near it, but the two groups are isolated by some kind of natural barrier (such as a river) that neither species can cross easily. (09 Oct 1997) |
| Young's rule | An obsolete rule to determine a child's dose: 12 is added to the child's age and the sum is divided by the age; the adult dose divided by the figure so obtained gives the proper dose. (05 Mar 2000) |
| Liebermeister's rule | In adult febrile tachycardia, about eight pulse beats correspond to an increase of 1캜. (05 Mar 2000) |
| Allen, Edgar Van Nuys | <person> U.S. Physician, 1900-1961. See: Allen's test. (05 Mar 2000) |
| Canavan-van Bogaert-Bertrand disease | Autosomal recessive degenerative disease of infancy; mostly in Jewish infants; onset typically within first 3-4 months of birth, consisting of blindness, psychomotor regression, enlarged head, optic atrophy, hypotonia, spasticity, increased N-acetylaspartic acid urinary excretion. MRI shows enlarged brain, decreased attenuation of cerebral and cerebellar white matter, and normal ventricles. Pathologically, there is increased brain volume and weight, and spongy degeneration in the subcortical white matter. See: leukodystrophy. Synonym: Canavan's sclerosis, Canavan-van Bogaert-Bertrand disease, spongy degeneration of infancy. (05 Mar 2000) |
| van | The front of an army; the first line or leading column; also, the front line or foremost division of a fleet, either in sailing or in battle. "Standards and gonfalons, twixt van and rear, Stream in the air." (Milton) Origin: Abbrev. Fr. Vanguard. 1. A fan or other contrivance, as a sieve, for winnowing grain. 2. [OF. Vanne, F. Vanneau beam feather (cf. It. Vanno a wing) fr. L. Vannus. See Etymology above] A wing with which the air is beaten. "[/Angels] on the air plumy vans received him. " "He wheeled in air, and stretched his vans in vain; His vans no longer could his flight sustain." (Dryden) Origin: L. Vannus a van, or fan for winnowing grain: cf. F. Van. Cf. Fan, Van a wing Winnow. <chemical> A shovel used in cleansing ore. Origin: Cornish. <chemical> To wash or cleanse, as a small portion of ore, on a shovel. Source: Websters Dictionary (01 Mar 1998) |