| molecular mass | 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) |
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| pill mass | The mixture of drug(s), excipients, diluents and binders with a suitable amount of liquid to form a plastic mass which can be rolled into a long rod and cut into the appropriate number of units for pills to be rolled from. Synonym: pill mass. (05 Mar 2000) |
| pilular mass | The mixture of drug(s), excipients, diluents and binders with a suitable amount of liquid to form a plastic mass which can be rolled into a long rod and cut into the appropriate number of units for pills to be rolled from. Synonym: pill mass. (05 Mar 2000) |
| complex liver mass in kids | <radiology> Epithelial, FNH (uncommon, F greater than M), hepatic adenoma (uncommon, F greater than M), hepatoma (increased aFP in 90%), hepatoblastoma (increased aFP, less than 2 years of age), mesenchymal, hamartoma, cavernous haemangioma, haemangioendothelioma, embryonal rhabdomyosarcoma (obstructs common bile duct; less than 5 years of age), undifferentiated sarcoma, teratoma, abscess / haematoma / complicated cyst (12 Dec 1998) |
| critical mass | <chemistry, radiobiology> The minimum amount of mass of a combination of radioactive substances needed for the substances to generate and lose an exactly balanced number of neutrons to make a chain reaction which will keep going by itself. (09 Oct 1997) |
| posterior mediastinal mass | <radiology> Mnemonic: HALOVEEN, haematoma, abscess, lymph nodexs, osteophyte, vertebral (metastasis, plasmacytoma), extramedullary haematopoesis, oesophagus, neurogenic (12 Dec 1998) |
| cystic pelvic mass | <radiology> Physiologic ovarian cyst, The Big Three (ectopic, PID, endometriosis), ovarian neoplasm, nongynecologic mass (12 Dec 1998) |
| cystic sellar mass | <radiology> Arachnoid cyst, cystic craniopharyngioma, dermoid / epidermoid (12 Dec 1998) |
| sclerotic cemental mass | Benign fibro-osseous jaw lesions of unknown aetiology, occurring predominantly in middle-aged black females, which present as large painless radiopaque masses usually involving several quadrants of the jaw. Synonym: florid osseous dysplasia, cemental dysplasia. (05 Mar 2000) |
| solid renal mass | <radiology> MALIGNANT until proven otherwise!, renal cell carcinoma (85%), other malignancy (10%), renal sarcoma, lymphoma, transitional cell carcinoma, metastases, benign mass (5%), oncocytoma, angiomyolipoma (fat present), fibroma (12 Dec 1998) |
| solitary echogenic liver mass | <radiology> Haemangioma, focal fatty infiltration, hepatoma, adenoma, focal nodular hyperplasia, hepatic lipoma (12 Dec 1998) |
| spectrometry, mass, fast atom bombardment | A mass spectrometric technique that is used for the analysis of a wide range of biomolecules, such as glycoalkaloids, glycoproteins, polysaccharides, and peptides. Positive and negative fast atom bombardment spectra are recorded on a mass spectrometer fitted with an atom gun with xenon as the customary beam. The mass spectra obtained contain molecular weight recognition as well as sequence information. (12 Dec 1998) |
| spectrometry, mass, matrix-assisted laser desorption-ionization | A mass spectrometric technique that is used for the analysis of large biomolecules. Analyte molecules are embedded in an excess matrix of small organic molecules that show a high resonant absorption at the laser wavelength used. The matrix absorbs the laser energy, thus inducing a soft disintegration of the sample-matrix mixture into free (gas phase) matrix and analyte molecules and molecular ions. In general, only molecular ions of the analyte molecules are produced, and almost no fragmentation occurs. This makes the method well suited for molecular weight determinations and mixture analysis. (12 Dec 1998) |
| spectrometry, mass, secondary ion | A mass-spectrometric technique that is used for microscopic chemical analysis. A beam of primary ions with an energy of 5-20 kiloelectronvolts (kev) bombards a small spot on the surface of the sample under ultra-high vacuum conditions. Positive and negative secondary ions sputtered from the surface are analyzed in a mass spectrometer in regards to their mass-to-charge ratio. (12 Dec 1998) |
| spectrum analysis, mass | Analysis of the mass of an object through means of determining the wave length(s) at which electromagnetic energy is absorbed by that object. (12 Dec 1998) |