| van Creveld, S | <person> Dutch paediatrician, *1894. See: Ellis-van Creveld syndrome. (05 Mar 2000) |
|---|---|
| van Deen, Izaak | <person> Dutch physiologist, 1804-1869. See: van Deen's test. (05 Mar 2000) |
| van Deen's test | Glacial acetic acid, gum guaiac solution, and hydrogen peroxide are added to an aqueous suspension of the suspected stain; if occult blood or blood pigment is present, a blue colour develops. Synonym: guaiac test, Schonbein's test, van Deen's test. (05 Mar 2000) |
| van den Bergh, A | <person> Dutch physician, 1869-1943. See: van den Bergh's test. (05 Mar 2000) |
| van den Bergh's test | A test for bile pigments (bilirubin) by reaction with diazotised sulfanilic acid (diazo reaction). (05 Mar 2000) |
| van der Hoeve's syndrome | <syndrome> A subtype of osteogenesis imperfecta in which progressive conductive hearing loss begins in childhood because of stapedial fixation. (05 Mar 2000) |
| van der Kolk, Jacobus | <person> Dutch physician, 1797-1862. See: van der Kolk's law. (05 Mar 2000) |
| van der Kolk's law | In a mixed nerve, the sensory fibres are distributed to the parts moved by the muscles controlled by the motor fibres. (05 Mar 2000) |
| van der Velden, Reinhardt | <person> German physician, 1851-1903. See: van der Velden's test. (05 Mar 2000) |
| van der Velden's test | A test for free hydrochloric acid, the presence of which turns an added solution of methylene blue from violet to green. (05 Mar 2000) |
| van der Waals attraction | <chemistry> Electrodynamic forces arise between atoms, molecules and assemblies of molecules due to their vibrations giving rise to electromagnetic interactions, these are attractive when the vibrational frequencies and absorptions are identical or similar, repulsive when nonidentical. Other interactions originally proposed by van der Waals were included in this name, but these are usually separated into the Coulomb's force, the Keesom force and the London force. Only the last is of electrodynamic nature. Probably important in holding lipid membranes into that structure and possibly in other interactions, for example cell adhesion. Electrodynamic forces between large scale assemblies can be of relatively long range nature. (18 Nov 1997) |
| van der Waals' forces | First postulated by van der Waals in 1873 to explain deviations from ideal gas behaviour seen in real gases; the attractive force's between atoms or molecules other than electrostatic (ionic), covalent (sharing of electrons), or hydrogen bonding (sharing a proton); generally ascribed to dipolar and dispersion effects, π-electrons, etc.; these relatively nondescript force's contribute to the mutual attraction of organic molecules. Synonym: London forces. (05 Mar 2000) |
| van der Waals, Johannes | <person> Dutch physicist and Nobel laureate, 1837-1923. See: van der Waals' forces. (05 Mar 2000) |
| van Ekenstein, W | <person> 19th century scientist. See: Lobry de Bruyn-van Ekenstein transformation. (05 Mar 2000) |
| van Ermengen, Emile | <person> Belgian bacteriologist, 1851-1932. See: van Ermengen's stain. (05 Mar 2000) |