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solstice

(Encyclopedia)solstice sŏlˈstĭs [key] [Lat.,=sun stands still], in astronomy, either of the two points on the ecliptic that lie midway between the equinoxes (separated from them by an angular distance of 90°). ...

National Radio Astronomy Observatory

(Encyclopedia)National Radio Astronomy Observatory (NRAO), federal observatory for radio astronomy, founded in 1956 and operated under contract with the National Science Foundation by Associated Universities, Inc.,...

mastectomy

(Encyclopedia)mastectomy măstĕkˈtəmē [key], surgical removal of breast tissue, usually done as treatment for breast cancer. There are many types of mastectomy. In general, the farther the cancer has spread, th...

Pap test

(Encyclopedia)Pap test, Pap smear, or Papanicolaou test păpˌənēˈkəlou [key], medical procedure used to detect cancer of the uterine cervix (see uterus). A scraping, brushing, or smear, is taken from the surf...

Slye, Maud

(Encyclopedia)Slye, Maud slī [key], 1879–1954, American pathologist, b. Minneapolis, grad. Brown, 1899. At the Univ. of Chicago she taught pathology, becoming professor emeritus in 1945, and was a member (1911...

gamma radiation

(Encyclopedia)gamma radiation, high-energy photons emitted as one of the three types of radiation resulting from natural radioactivity. It is the most energetic form of electromagnetic radiation, with a very short ...

Young, Charles Augustus

(Encyclopedia)Young, Charles Augustus, 1834–1908, American astronomer, b. Hanover, N.H., grad. Dartmouth, 1853. He discovered the reversing layer of the solar atmosphere and proved the gaseous nature of the sun's...

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...

DES

(Encyclopedia)DES or diethylstilbestrol dīˌĕthˌəlstĭlbĕsˈtrôl [key], synthetic nonsteroid female sex hormone having the same physiological effects as estrogen. In the 1940s and 50s DES was mistakenly belie...

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