| follicular cancer of the thyroid | <oncology, tumour> A cancer of the thyroid gland that occurs with increased frequency in those who have had radiation exposure to the neck. Other risk factors include a family history of thyroid disease and history for goitre. Follicular carcinoma constitutes about 30% of all thyroid cancers. It has a greater rate of recurrence and metastasis than that of papillary carcinoma (the most common form of thyroid cancer). Symptoms include enlargement of the thyroid gland or neck swelling, change in voice, cough (occasionally bloody) and diarrhoea. (12 Nov 1997) |
|---|---|
| laryngeal cancer | A malignant (cancerous) tumour of the larynx. Presentation includes a progressively hoarse voice, difficulty swallowing and weight loss. Risk factors include smoking and heavy alcohol consumption. (27 Sep 1997) |
| Li-Fraumeni cancer syndrome | <syndrome> Familial breast cancer in young women, with soft-tissue sarcomas in children and other cancers in close relatives. (05 Mar 2000) |
| liver cancer | <oncology, tumour> A tumour of the liver. most cancer involving the liver is spread (metastatic) from other areas (colon, breast or lung). See: hepatoma. (27 Sep 1997) |
| localised cancer | A cancer still confined to its site of origin. (09 Oct 1997) |
| lung cancer | A cancerous growth in lung tissue. Lung cancer may be metastatic from another source (colon) or may be primary (tumour is of lung cell origin). Classification is based on the type of cell the lung cancer originates from (adenocarcinoma, alveolar cell carcinoma, squamous cell carcinoma, large cell and small cell carcinomas). (27 Sep 1997) |
| Abbe theory of image formation | <optics, physics> Abbe's theory is based on the fact that a non-self-luminous particle, which is illuminated by an extraneous source, gives rise to diffracted light rays, in addition to the dioptric pencil. He stated that to form a good microscopical image as many of the diffracted rays as possible should be intercepted by the objective. With closely ruled lines, his theory is easily demonstrated by observing the back lens of the objective, for here the diffracted rays can be observed directly if the aperture diaphragm is closed. It can be shown that, when the illumination is arranged to exclude the diffracted images, resolution is lost. (11 Mar 1998) |
| adsorption theory of narcosis | That a drug becomes concentrated at the surface of the cell as a result of adsorption, and thus alters permeability and metabolism. (05 Mar 2000) |
| Altmann's theory | A theory that protoplasm consists of granular particles (called bioblasts) that are clustered and enclosed in indifferent matter. (05 Mar 2000) |
| Arrhenius-Madsen theory | That the reaction of an antigen with its antibody is a reversible reaction, the equilibrium being determined according to the law of mass action by the concentrations of the reacting substances. (05 Mar 2000) |
| atomic theory | That chemical compounds are formed by the union of atoms in certain definite proportions; in its modern form, first advanced in 1803 by John Dalton. (05 Mar 2000) |
| Baeyer's theory | That carbon bonds are set at fixed angles (109 |
| balance theory | In social psychology, a theory which assumes that steady and unsteady states can be specified for cognitive units, such as an individual and his or her attitudes or acts, and that such units tend to seek steady states (balance); e.g., balance exists when both parts of a unit are evaluated the same, but disequilibrium arises when both parts are not evaluated the same, which causes either cognitive reevaluation of the parts or their segregation. See: cognitive dissonance theory, consistency principle. (05 Mar 2000) |
| beta-oxidation-condensation theory | <biochemistry> That the two carbon fragments split from the fatty acid molecule by beta-oxidation are converted to acetic acid and then condensed to acetoacetic acid. (05 Mar 2000) |
| Bohr's theory | That spectrum lines are produced 1) by the quantised emission of radiant energy when electrons drop from an orbit of a higher to one of a lower energy level, or 2) by absorption of radiation when an electron rises from a lower to a higher energy level. (05 Mar 2000) |