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fatigue, in physiology

(Encyclopedia)fatigue, in physiology, inability to perform reasonable and necessary physical or mental activity. Muscle fatigue, for example, results when the contractile properties of muscle are reduced, and conti...

acne

(Encyclopedia)acne, common inflammatory disease of the hair follicles and sebaceous glands characterized by blackheads, whiteheads, pustules, nodules and, in the more severe forms, by cysts and scarring. The lesion...

bismuth

(Encyclopedia)bismuth bĭzˈməth [key] [Ger. Weisse Masse=white mass], metallic chemical element; symbol Bi; at. no. 83; at. wt. 208.98040; m.p. 271.3℃; b.p. about 1,560℃; sp. gr. 9.75 at 20℃; valence +3 or ...

bleaching

(Encyclopedia)bleaching, process of whitening by chemicals or by exposure to sun and air, commonly applied to textiles, paper pulp, wheat flour, petroleum products, oils and fats, straw, hair, feathers, and wood. C...

sting

(Encyclopedia)sting, in zoology, organ found in bees, many wasps, some ants, and in scorpions and sting rays, used defensively as well as to kill or paralyze prey. In the bee and the wasp the venom is produced by g...

sulfa drug

(Encyclopedia)sulfa drug, any of a class of synthetic chemical substances derived from sulfanilamide, or para-aminobenzenesulfonamide. Sulfa drugs are used to treat bacterial infections, although they have largely ...

cassava

(Encyclopedia)cassava mănˈēŏk [key], name for many species of the genus Manihot of the family Euphorbiaceae (spurge family). The roots, which resemble sweet potatoes and are eaten in much the same way, yield ca...

vinegar

(Encyclopedia)vinegar, sour liquid consisting mainly of acetic acid and water, produced by the action of bacteria on dilute solutions of ethyl alcohol derived from previous yeast fermentation. The coloring and flav...

fermented milk

(Encyclopedia)fermented milk, whole or skim milk curdled to beverage or custardlike consistency by lactic-acid-producing microorganisms. Many forms of fermented milk were used by early nomadic herders, especially i...

Graham, Thomas

(Encyclopedia)Graham, Thomas, 1805–69, Scottish chemist, best known for research in diffusion in both gases and liquids that led to his formulation of Graham's law. His discovery that certain substances (e.g., gl...