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cysteine

(Encyclopedia)CE5 CE5 cysteine sĭsˈtēn [key], organic compound, one of the 20 amino acids commonly found in animal proteins. Only the l-stereoisomer participates in the biosynthesis of mammalian protein...

circumcision

(Encyclopedia)circumcision sûrˌkəmsĭzhˈən [key], operation to remove the foreskin covering the glans of the penis. It dates back to prehistoric times and was widespread throughout the Middle East as a religio...

chromium

(Encyclopedia)chromium krōˈmēəm [key] [Gr.,=color], metallic chemical element; symbol Cr; at. no. 24; at. wt. 51.9961; m.p. about 1,857℃; b.p. 2,672℃; sp. gr. about 7.2 at 20℃; valence +2, +3, +6. Chromiu...

coal mining

(Encyclopedia)coal mining, physical extraction of coal resources to yield coal; also, the business of exploring for, developing, mining, and transporting coal in any form. Coal has been historically important indus...

Philip II, king of Macedon

(Encyclopedia)Philip II, 382–336 b.c., king of Macedon (359–336 b.c.), son of Amyntas II. While a hostage in Thebes (367–364), he gained much knowledge of Greece and its people. He was appointed regent for Am...

Russell, John Russell, 1st Earl

(Encyclopedia)Russell, John Russell, 1st Earl, 1792–1878, British statesman; younger son of the 6th duke of Bedford, known most of his life as Lord John Russell. He became a Whig member of Parliament in 1813 and ...

titanium

(Encyclopedia)titanium tītāˈnēəm, tĭ– [key] [from Titan], metallic chemical element; symbol Ti; at. no. 22; at. wt. 47.867; m.p. 1,675℃; b.p. 3,260℃; sp. gr. 4.54 at 20℃; valence +2, +3, or +4. Titani...

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 ...

osteoporosis

(Encyclopedia)osteoporosis ŏsˌtēōˌpərōˈsĭs [key], disorder in which the normal replenishment of old bone tissue is severely disrupted, resulting in weakened bones and increased risk of fracture; osteopenia...

boron

(Encyclopedia)boron bōrˈŏn [key] [New Gr. from borax], chemical element; symbol B; at. no. 5; interval in which at. wt. ranges 10.806–10.821; m.p. about 2,300℃; sublimation point about 2,550℃; sp. gr. 2.3 ...