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radiation sickness

(Encyclopedia)radiation sickness, harmful effect produced on body tissues by exposure to radioactive substances. The biological action of radiation is not fully understood, but it is believed that a disturbance in ...

quasicrystal

(Encyclopedia)quasicrystal kwāˈzīkrĭsˌtəl, kwäzˈē– [key] or quasiperiodic solid, solid body that exhibits such crystalline features as symmetry and repeating patterns of unit cells (regular arrangements ...

blood groups

(Encyclopedia)blood groups, differentiation of blood by type, classified according to immunological (antigenic) properties, which are determined by specific substances on the surface of red blood cells. Blood group...

eye

(Encyclopedia)CE5 Cross section of human eye eye, organ of vision and light perception. In humans the eye is of the camera type, with an iris diaphragm and variable focusing, or accommodation. Other types of ey...

cycad

(Encyclopedia)cycad sīˈkăd [key], any plant of the order Cycadales, tropical and subtropical palmlike evergreens. The cycads, ginkgoes, and conifers comprise the three major orders of gymnosperms, or cone-bearin...

banana

(Encyclopedia)banana, name for several species of the genus Musa and for the fruits these produce. The banana plant—one of the largest herbaceous plants—is native to tropical Asia but now cultivated throughout ...

Lindahl, Tomas

(Encyclopedia)Lindahl, Tomas, 1938–, Swedish-born British biochemist, grad. Karolinska Institute (Ph.D. 1967, M.D. 1970). Lindahl was a professor at the Univ. of Gothenburg from 1978 to 1982. In 1981 he joined th...

lactic acid

(Encyclopedia)lactic acid, CH3CHOHCO2H, a colorless liquid organic acid. It is miscible with water or ethanol. Lactic acid is a fermentation product of lactose (milk sugar); it is present in sour milk, koumiss, leb...

Modrich, Paul Lawrence

(Encyclopedia)Modrich, Paul Lawrence, 1946–, American biochemist and molecular geneticist, b. Raton, N.M., Ph.D. Stanford Univ., 1973. Modrich joined the faculty at the Duke Univ. School of Medicine in 1976, and ...

acetylcholine

(Encyclopedia)acetylcholine əsētˌəlkōˈlēn [key], a small organic molecule liberated at nerve endings as a neurotransmitter. It is particularly important in the stimulation of muscle tissue. The transmission ...