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perfluoroalkyl and polyfluoroalkyl substances

(Encyclopedia)perfluoroalkyl and polyfluoroalkyl substances (PFAS), a group of several thousand synthetic organic chemical compounds made up of a chain of carbon atoms bonded to fluorine atoms. PFAS, which resist w...

pharmacology

(Encyclopedia)pharmacology, study of the changes produced in living animals by chemical substances, especially the actions of drugs, substances used to treat disease. Systematic investigation of the effects of drug...

Witherspoon, John

(Encyclopedia)Witherspoon, John, 1723–94, Scottish-American Presbyterian clergyman, political leader in the American Revolution, and signer of the Declaration of Independence, b. Haddingtonshire (now East Lothian...

ultraviolet radiation

(Encyclopedia)ultraviolet radiation, invisible electromagnetic radiation between visible violet light and X rays; it ranges in wavelength from about 400 to 4 nanometers and in frequency from about 1015 to 1017 hert...

growth hormone

(Encyclopedia)growth hormone or somatotropin sōmătˌətrōˈpən [key], glycoprotein hormone released by the anterior pituitary gland that is necessary for normal skeletal growth in humans (see protein). Evidence...

meprobamate

(Encyclopedia)meprobamate məprōˈbəmātˌ [key], tranquilizing drug that acts as a depressant of the central nervous system and is commonly used in the treatment of anxiety and sometimes schizophrenia. Although ...

mineral water

(Encyclopedia)mineral water, spring water containing various mineral salts, especially the carbonates, chlorides, phosphates, silicates, sulfides, and sulfates of calcium, iron, lithium, magnesium, potassium, sodiu...

Muller, Hermann Joseph

(Encyclopedia)Muller, Hermann Joseph mŭlˈər [key], 1890–1967, American geneticist and educator, b. New York City, grad. Columbia (B.A., 1910; Ph.D., 1916). A student of Thomas Hunt Morgan, he taught (1915–18...

mustard gas

(Encyclopedia)mustard gas, chemical compound used as a poison gas in World War I. The burning sensation it causes on contact with the skin is similar to that caused by oil from black mustard seeds. The compound is ...

Macdonald, Dwight

(Encyclopedia)Macdonald, Dwight, 1906–82, American author and editor, b. New York City. As an associate editor (1928–36) of the business magazine Fortune he acquired a distaste for capitalism, and in 1937 he be...