(Encyclopedia) geriatricsgeriatricsjĕrēăˈtrĭks [key], the branch of medicine concerned with conditions and diseases of the aged. Many disabilities in old age are caused by or related to the…
(Encyclopedia) doll, small figure of a human being, usually used as a child's toy. The many types of dolls found among the relics of primitive peoples were cult objects. Egypt, Greece, and Rome have…
(Encyclopedia) pterosaurpterosaurtĕrˈəsôrˌ [key] [Gr., = winged lizard], extinct flying reptile (commonly called pterodactyl [Gr., = wing finger]) of the order Pterosauria, common in the late…
(Encyclopedia) AZT or zidovudinezidovudinezīdōˈvy&oomacr;dēnˌ [key], drug used to treat patients infected with the human immunodeficiency virus (HIV), which causes AIDS; also called…
(Encyclopedia) blood bank, site or mobile unit for collecting, processing, typing, and storing whole blood, blood plasma and other blood constituents. Most hospitals maintain their own blood reserves…
(Encyclopedia) calciumcalciumkălˈsēəm [key] [Lat.,=lime], metallic chemical element; symbol Ca; at. no. 20; at. wt. 40.078; m.p. about 839℃; b.p. 1,484℃; sp. gr. 1.55 at 20℃; valence +2. Calcium is a…
(Encyclopedia) phosphorusphosphorusfŏsˈfərəs [key] [Gr.,=light-bearing], nonmetallic chemical element; symbol P; at. no. 15; at. wt. 30.97376; m.p. 44.1℃; b.p. about 280℃; sp. gr. 1.82 at 20℃;…
Ancestor of Mammals Discovered The fossil skull of a 260-million-year-old sheep-sized animal was found near Williston on the Northern Cape, South Africa. It is the most primitive member yet…
—Borgna BrunnerVital Stats of the Universe In one of the most important cosmological discoveries in years, NASA scientists have captured the most precise image of the universe, shedding light on…
Dinosaurs lived throughout the Mesozoic Era, which began 245 million years ago and lasted for 180 million years. It is sometimes called the Age of the Reptiles. The era is divided into three…
