| high energy particle generating unit | A machine capable of providing highly energised radiation for the purposes of radiotherapy treatment. (16 Dec 1997) |
|---|---|
| Holzknecht unit | An obsolete unit of X-ray dosage equal to one-fifth of the erythema dose. (05 Mar 2000) |
| Hounsfield unit | A normalised index of X-ray attenuation based on a scale of -1000 (air) to +1000 (bone), with water being 0; used in CT imaging. (05 Mar 2000) |
| Howell unit | The quantity of heparin required to keep 1 ml of cat's blood fluid for 24 hr at 0캜; it is equivalent approximately to 0.002 mg of pure heparin. Synonym: Howell unit. (05 Mar 2000) |
| Sherman-Bourquin unit of vitamin B2 | The amount of vitamin B2 required in the diet daily to sustain an average weekly gain of 3 g for 8 weeks in standard test rats; one unit is equivalent to 1 to 7 ug (0.001 to 0.007 mg) of riboflavin, depending on the deficiency diet used in the above assay. (05 Mar 2000) |
| Sherman-Munsell unit | A rat growth unit; the daily amount of vitamin A which sustains a rate of gain amounting to 3 g a week in standard test rats. (05 Mar 2000) |
| Sherman unit | Unit of vitamin C, minimum protective dose; the minimum amount of vitamin C which, fed daily, will protect a 300-g guinea pig from scurvy for 90 days; equivalent to 0.5 to 0.6 mg of ascorbic acid. (05 Mar 2000) |
| SI unit | <chemistry, physics> An International System of Units of measurement in which the fundamental units are standardised. Examples include: metre, kilometre, ampere, gray, joule, Sievert, Becquerel. Origin: Fr. Le Systeme International d'Unites (18 Nov 1997) |
| Somogyi unit | A measure of the level of activity of amylase in blood serum, as analyzed by means of the Somogyi method (the most frequently used procedure); one unit is equivalent to 1 mg of reducing sugar liberated as glucose per 100 ml of serum, when an aliquot of the latter is mixed with a standard starch substrate (plus sodium chloride for maximal activation) and incubated for a standard time; normal range is 80 to 150 unit's, but values are usually not regarded as clinically significant unless they are greater than 200. (05 Mar 2000) |
| Steenbock unit | A unit of vitamin D; the total amount of vitamin D which will produce within 10 days a narrow line of calcium deposit in the rachitic metaphyses of the distal ends of the radii and ulnae of standard rachitic rats. (05 Mar 2000) |
| nephelometric turbidity unit | A measurement unit of the clarity of water, dependent on the amount of suspended matter. (05 Dec 1998) |
| Dam unit | A unit of activity of vitamin K; the smallest amount of vitamin K, per gram of chick per day, capable of producing normal coagulability in the blood of K-avitaminotic chicks after 3 days of oral administration. (05 Mar 2000) |
| Svedberg unit | A sedimentation constant of 1 × 10-13 seconds. (05 Mar 2000) |
| digitalis unit | The activity of 0.1 g of the international standard powdered digitalis. (05 Mar 2000) |
| diphtheria antitoxin unit | The antitoxin activity of 0.0628 mg standard diphtheria antitoxin. (05 Mar 2000) |