| gyromagnetic ratio | In nuclear magnetic resonance, the ratio of the magnetic dipole moment of the nucleus to the nuclear spin angular momentum; the gyromagnetic ratio is a unique value for each type of nucleus. Synonym: magnetogyric ratio. (05 Mar 2000) |
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| molecular weight ratio | The sum of the atomic weight's of all the atoms constituting a molecule; the mass of a molecule relative to the mass of a standard atom, now 12C (taken as 12.000). Relative molecular mass (Mr) is the mass relative to the dalton and has no units. See: atomic weight. Synonym: molecular mass, molecular weight ratio, relative molecular mass. (05 Mar 2000) |
| P/O ratio | A measure of oxidative phosphorylation; the ratio of phosphate radicals esterified (forming adenosine 5'-triphosphate from adenosine 5'-diphosphate) to atoms of oxygen consumed by mitochondria; normally, the ratio is 3 (starting from NADH). Synonym: P/O quotient. (05 Mar 2000) |
| hand ratio | The ratio of the length of the hand (measured on the dorsum from the styloid process of the ulna to the tip of the third finger) to the width across the knuckles. (05 Mar 2000) |
| segregation ratio | In genetics, the proportion of progeny of a particular genotype or phenotype from actual matings of specified genotypes. The test of a Mendelian hypothesis is the comparison of the segregation rate with the Mendelian rate. (05 Mar 2000) |
| sex ratio | The number of males per 100 females. (12 Dec 1998) |
| signal-to-noise ratio | <microscopy> Also sometimes used as an abbreviation for serial number, can be somewhat confusing in the case of electronic equipment. (05 Aug 1998) |
| split ratio | The fraction of the cells in a fully grown culture of animal cells that should be used to start a subsequent culture. Minimum may be dictated by medium inadequacies that result in poor growth of some cells at high dilution. (18 Nov 1997) |
| standardised mortality ratio | The ratio of the number of events observed in a population to the number that would be expected if the population had the same distribution as a standard or reference population. (05 Mar 2000) |
| nuclear-cytoplasmic ratio | Ratio of volume of nucleus to volume of cytoplasm, fairly constant for a particular cell type and usually increased in malignant neoplasms. (05 Mar 2000) |
| nucleolar-nuclear ratio | Ratio of volume of nucleolus to volume of nucleus, usually increased in malignant neoplasms. (05 Mar 2000) |
| nutritive ratio | The ratio or proportion of digestible protein to digestible non-nitrogenous nutrients in a ration for livestock. (05 Mar 2000) |
| systolic/diastolic ratio | A calculation from pulsed Doppler ultrasound determinations of blood flow velocities that reflects intrinsic resistance in an arterial blood vessel. (05 Mar 2000) |
| international normalised ratio | System established by the world health organization and the international committee on thrombosis and haemostasis for monitoring and reporting blood coagulation tests. Under this system, results are standardised using the international sensitivity index for the particular test reagent/instrument combination used. (12 Dec 1998) |
| IRI/G ratio | The ratio of immunoreactive insulin to serum or plasma glucose; in hypoglycaemic states a ratio of less than 0.3 is usual with the exception of the hypoglycaemia due to insulinoma, where the ratio is often higher than 0.3. (05 Mar 2000) |