| immediately dangerous to life concentration | <radiobiology> This is a regulatory value defined as the maximum exposure concentration in the workplace from which one could escape within 30 minutes without suffering symptoms which would interfere with escaping and without suffering any irreversible health effects. (04 Nov 1997) |
|---|---|
| osmolar concentration | The concentration of osmotically active particles in solution expressed in terms of osmoles of solute per liter of solution. Osmolality is expressed in terms of osmoles of solute per kilogram of solvent. (12 Dec 1998) |
| urinary concentration test | A test of renal tubular function whereby the patient is dehydrated for a measured period of time and the specific gravity of the urine is subsequently determined. (05 Mar 2000) |
| Fishberg concentration test | A test of renal water conservation; after overnight fluid deprivation, morning urine samples are collected and specific gravity is measured. (05 Mar 2000) |
| adrenal mass | <radiology> Metastasis, most common (especially lung, melanoma), primary adenocarcinoma, large at diagnosis (greater than 5 cm), usually functional (increased corticosteroids most likely to be Cushing's), rapid growth, benign adrenal adenoma, with or without functional, nonfunctional occurs in 2-8% of population, diff from metastasis: MRI (metastasis bright on T2), biopsy, follow, pheochromocytoma, neuroblastoma, myelolipoma, cyst / pseudocyst see also: adrenal calcification, haemorrhage (12 Dec 1998) |
| apperceptive mass | The already existing knowledge base in a similar or related area with which the new perceptual material is articulated. (05 Mar 2000) |
| atomic mass | <chemistry, physics> The mass of an atom relative to other atoms. The present-day basis of the scale of atomic weights is carbon, the most common isotope of this element has arbitrarily been assigned an atomic weight of 12. The unit of the scale is 1/12 the weight of the carbon atom or roughly the mass of one proton or one neutron. The atomic weight of any element is approximately equal to the total number of protons and neutrons in is nucleus (16 Dec 1997) |
| atomic mass unit | <chemistry> One-twelfth the mass of a neutral atom of the most abundant isotope of carbon. (16 Dec 1997) |
| bilateral adrenal mass | <radiology> Acute granulomatous disease (e.g., TB), metastases (bilateral in 15%), pheochromocytoma (bilateral in 10%), adrenal hyperplasia (adenoma), spontaneous adrenal haemorrhage (12 Dec 1998) |
| body mass index | One of the anthropometric measures of body mass; it has the highest correlation with skinfold thickness or body density. (12 Dec 1998) |
| breast mass | <oncology, surgery> A breast lump may be benign or cancerous. Examples of breast lumps include: breast abscess, fat necrosis, fibroadenoma, fibrocystic breast disease and breast cancer. A breast biopsy is the best way to determine the aetiology of a breast lump. Remember, 80 to 85% of all biopsies are benign. (27 Sep 1997) |
| para-sellar mass | <radiology> Mnemonic: SATCHMO, S sphenoid sinus tumour, A aneurysm / adenoma of pituitary, T teratoid lesion, C craniopharyngioma, H hypothalamic glioma / histiocytoma, M meningioma / metastasis, O optic glioma less common lesions: germinoma, epidermoid, hamartoma, chordoma, arachnoid cyst (12 Dec 1998) |
| mass | <chemistry> The quantity of matter in an object. (09 Jan 1998) |
| mass-action ratio | The ratio of the product of all of the product concentrations divided by the product of all of the reactant concentrations of a particular reaction; when the reaction has been completed (i.e., t = ∞), then this ratio is equal to the equilibrium constant. (05 Mar 2000) |
| mass action theory | That large areas of brain tissue function as a whole in learned or intelligent action. (05 Mar 2000) |