| molecular formula | In chemistry, a formula indicating the kind and number of atoms in the molecules of a substance, or its composition, but not the relation of the atoms to each other or the intimate structure of the molecule. Synonym: molecular formula. (05 Mar 2000) |
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| Pignet's formula | See: Black's formula. (05 Mar 2000) |
| constitutional formula | A formula in which the connections of the atoms and groups of atoms, as well as their kind and number, are indicated. Synonym: constitutional formula, graphic formula. (05 Mar 2000) |
| Poisson-Pearson formula | A formula to determine the statistical error in calculating the endemic index of malaria: let N = total number of children under 15 years in a locality; n = total number examined for the spleen-rate; x = number found with enlarged spleen; (x/n)100 = spleen-rate; e% = percentage of error; the percentage error will be, by this formula: (05 Mar 2000) |
| Hamilton-Stewart formula | Formula to calculate cardiac output after intravenous indicator dye injection; blood flow in liters per minute is given by dividing the amount of injectant in milligrams by the product of the average dye concentration in the initial curve of the dye concentration sampled at a given point in the circulation and multiplied by the dose of dye (in milligrams) to write the curve from appearance to disappearance (in the absence of any recirculation). Synonym: Hamilton-Stewart formula, Stewart-Hamilton method. (05 Mar 2000) |
| Haser's formula | A formula to determine the number of grams of urinary solids per liter, obtained by multiplying 2.33 by the last two figures of the specific gravity of the urine. Synonym: Christison's formula, Trapp's formula, Trapp-Haser formula. (05 Mar 2000) |
| Haworth conformational formula | <biochemistry> Of cyclic sugars, for the pyranoses, these depict those shapes (conformations) on which none, one, or two ring-atoms lie outside the plane of the ring. If there are two such atoms para to each other, they can lie 1) on opposite sides of the plane (trans), giving chair forms, or 2) on the same side of the plane (cis), giving boat forms. For beta-d-ribopyranose, the two chair forms (4C1 and 1C4) are depicted. Similarly, there are six boat conformations. If the two (trans) exoplanar atoms are meta to each other, the conformation is a skew form; if the two atoms are ortho to each other, the conformation is a half-chair form. For the furanoses, the envelope conformations have one ring-atom exoplanar. If there are three adjacent, coplanar ring-atoms (the two exoplanar ring-atoms on opposite sides of the plane), the conformations are twist forms. (05 Mar 2000) |
| Haworth perspective formula | <biochemistry> Of cyclic sugars, perspective representations of furanose or pyranose structures as pentagons or hexagons, respectively, with the connecting bonds so shaded as to make them appear as though the plane of the ring is at an angle of 30 |
| spatial formula | A chemical formula in which the arrangement of the atoms or atomic groupings in space are indicated. Synonym: spatial formula. (05 Mar 2000) |
| stereochemical formula | A chemical formula in which the arrangement of the atoms or atomic groupings in space are indicated. Synonym: spatial formula. (05 Mar 2000) |
| structural formula | A formula in which the connections of the atoms and groups of atoms, as well as their kind and number, are indicated. Synonym: constitutional formula, graphic formula. (05 Mar 2000) |
| Demoivre's formula | An obsolete formula for calculating life expectancy. (05 Mar 2000) |
| dental formula | <dentistry> A statement in tabular form of the number of each kind of teeth in the jaw; the dental formula for man is, for the deciduous teeth: for the permanent teeth: (05 Mar 2000) |
| Dreyer's formula | An obsolete formula indicating relationship between vital capacity and body surface area. (05 Mar 2000) |
| DuBois' formula | A formula for predicting a man's surface area from weight and height: A = 71.84W0.425 H0.725, where A = surface area in cm2, W = weight in kg, and H = height in cm. (05 Mar 2000) |