| PVR | peripheral vascular resistance; perspective volume rendering; poliovirus receptor; postvoiding resid... |
|---|---|
| RA | radioactive; ragocyte; ragweed antigen; rapidly adapting [receptors]; reactive arthritis; reciprocal... |
| RLC | residual lung capacity |
| RLO | residual lymphatic output |
| ROC | receiver operating characteristic; receptor-operated channels; relative operating characteristic; re... |
| nitrogen narcosis | Narcosis produced by nitrogenous materials such as occurs in certain forms of uraemia and hepatic coma, the stuporous condition characterised by disorientation and by loss of judgment and skill, attributed to an increased partial pressure of nitrogen in the inspired air of deepsea divers during underwater operations. Commonly referred to as "rapture of the deep." (05 Mar 2000) |
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| nitrogen oxides | Inorganic oxides that contain nitrogen. (12 Dec 1998) |
| nitrogen partition | Determination of the distribution of nitrogen in the urine among the various constituents. Synonym: nitrogen distribution. (05 Mar 2000) |
| nitrogen radioisotopes | Unstable isotopes of nitrogen that decay or disintegrate emitting radiation. N atoms with atomic weights 12, 13, 16, 17, and 18 are radioactive nitrogen isotopes. (12 Dec 1998) |
| nonprotein nitrogen | The nitrogen content of other than protein bodies; e.g., about one-half the nonprotein nitrogen in the blood is contained in urea. Synonym: rest nitrogen. (05 Mar 2000) |
| undetermined nitrogen | The nitrogen of blood, urine, etc., other than urea, uric acid, amino acids, etc., that can be directly estimated; in blood it amounts to about 25 mg per 100 ml. Urea nitrogen, the portion of nitrogen in a biological sample, such as blood or urine, that derives from its content of urea. See: blood urea nitrogen. (05 Mar 2000) |
| urinary nitrogen | Nitrogen excreted as urea, amino acids, uric acid, etc., in the urine; 1 g of urinary nitrogen indicates the breakdown in the body of 6.25 g of protein. See: nitrogen equivalent. (05 Mar 2000) |
| filtrate nitrogen | Nonprotein nitrogen in various compounds that normally pass through the glomerular filtration, or through a filter in the laboratory (after proteins are precipitated). (05 Mar 2000) |