| HofF | height of fundus |
|---|---|
| RO | radiation oncology; radiation output; ratio of; relative odds; renal osteodystrophy; reverse osmosis... |
| R/O | rule out |
| CO | 1) Cardiac Output = Stroke Volume x HR Stroke Volume °áÁ¤ÀÎÀÚ<... |
| VAN | Vein, Artery, NerveÀÇ ¼øÀ¸·Î |
| NPRM | Notice of Proposed Rule Making |
|---|---|
| ATR | against the rule |
| WTR | with the rule |
| VHL | Van Hippel-Lindau disease |
| VWS | Van der Woude syndrome |
| Le Bel-van't Hoff rule | The number of stereoisomers of an organic compound is 2n where n represents the number of asymmetric carbon atoms (unless there is an internal plane of symmetry). A corollary of their simultaneously announced conclusions, in 1874, that the most probable orientation of the bonds of a carbon atom linked to four groups or atoms is toward the apexes of a tetrahedron, and that this accounted for all then-known phenomena of molecular asymmetry (which involved a carbon atom bearing four different atoms or groups). See: stereoisomerism. (05 Mar 2000) |
|---|---|
| van't Hoff, Jacobus | <person> Dutch chemist and Nobel laureate, 1852-1911. See: van't Hoff's equation, van't Hoff's law, van't Hoff's theory, Le Bel-van't Hoff rule. (05 Mar 2000) |
| van't Hoff's equation | Equation for osmotic pressure of dilute solutions. See: van't Hoff's law. For any reaction, d(ln Keq/d(1/T) equals -dH/R where Keq is the equilibrium constant, T the absolute temperature, R is the universal gas constant, and dH is the change in enthalpy; thus, plotting ln Keq vs. 1/T allows the determination of dH. (05 Mar 2000) |
| van't Hoff's law | In stereochemistry, all optically active substances have one or more multivalent atoms united to four different atoms or radicals so as to form in space an unsymmetrical arrangement, the osmotic pressure exerted by any substance in very dilute solution is the same that it would exert if present as gas in the same volume as that of the solution; or, at constant temperature, the osmotic pressure of dilute solutions is proportional to the concentration (number of molecules) of the dissolved substance; i.e., the osmotic pressure, π, in dilute solutions is π = RTσci, where R is the universal gas constant, T is the absolute temperature, and ci is the molar concentration of solute i, the rate of chemical reactions increases between two-and three-fold for each 10°C rise in temperature. (05 Mar 2000) |
| van't Hoff's theory | That substances in dilute solution obey the gas laws. Compare: van't Hoff's law. (05 Mar 2000) |
| Abegg's rule | The tendency of the sum of the maximum positive and maximum negative valence of a particular element to equal 8; e.g., C may have a valence of +4 and -4, O of +6 and -2. Sometimes loosely stated as all atoms have the same number of valences, a consequence of the tendency of valence electron shells to be filled to 8. (05 Mar 2000) |
| American Law Institute rule | A test of criminal responsibility (1962): "a person is not responsible for criminal conduct if at the time of such conduct as a result of mental disease or defect he lacks substantial capacity either to appreciate the wrongfulness of his conduct or to conform his conduct to the requirements of law." (05 Mar 2000) |
| astigmatism against the rule | Astigmatism when the greater curvature or refractive power is in the horizontal meridian. (05 Mar 2000) |
| astigmatism with the rule | Astigmatism when the greater curvature or refractive power is in the vertical meridian. (05 Mar 2000) |
| pair rule gene | <molecular biology> A segmentation gene, expressed sequentially between gap genes and segment polarity genes. In development of Drosophila, a set of about 8 genes that are expressed only in alternate segments (odd or even) of the developing embryo. Loss of function mutants thus lack alternate segments. Examples: even skipped (eve), fushi tarazu (ftz), hairy. (18 Nov 1997) |
| Gibb's phase rule | An expression of the relationships existing between systems in equilibrium: P + V = C + 2, where P is the number of phases, V the variance or degrees of freedom, and C the number of components; it also follows that the variance is, V = C + 2 -P. For H2O at its triple point, V = 1 + 2 -3 = 0, i.e., both temperature and pressure are fixed. Synonym: Gibb's phase rule. (05 Mar 2000) |
| Gloger's rule | The rule or observation that the skin of a warm-blooded animal species tends to become darker in colour towards warmer climates at lower altitudes or lower latitudes, and to become lighter in colour towards colder climates at higher altitudes or higher latitudes. (09 Oct 1997) |
| Goriaew's rule | Rarely used term for a rule of a blood counting field by which it is marked off in a series of squares, some of which are again subdivided into sixteen smaller ones. (05 Mar 2000) |
| Chargaff's rule | In DNA the number of adenine units equals the number of thymine units; likewise, the number of guanine units equals the number of cytosine units. (05 Mar 2000) |
| gt-ag rule | This is the observation that all introns in DNA begin with the nucleotides of GT(guanine, thymine) and end with the nucleotides AG (adenine, guanine). When the DNA is transcribed into RNA, the introns are removed from the RNA by a mechanism which recognises these beginning and ending nucleotides - in the RNA they would be CU (cytosine, uracil) and AC (adenine, cytosine). (09 Oct 1997) |
| van't Hoff's rule |
[Jacobus Henricus van't Hoff, Dutch chemist, 1852?1911] The rule that the speed of chemical reactions is doubled, at least, for each 10¡ÆC rise in temperature.
Ãâó:
|
|---|
Á¦Ç°¸í |
ÆÇ¸Å»ç |
º¸ÇèÄÚµå | ¼ººÐ/ÇÔ·® | ±¸ºÐ/º¸Çè±Þ¿© |
|---|
Á¦Ç°¸í |
ÆÇ¸Å»ç |
º¸ÇèÄÚµå | ¼ººÐ/ÇÔ·® | ±¸ºÐ/º¸Çè±Þ¿© |
|---|