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burn

(Encyclopedia)burn, injury resulting from exposure to heat, electricity, radiation, or caustic chemicals. Three degrees of burn are commonly recognized. In first-degree burns the outer layer of skin, called epiderm...

injection

(Encyclopedia)injection, introduction of a fluid into the body, usually by means of a needle and syringe. The material injected may be a test substance (as in determining allergic sensitivity or immunity to a disea...

erythema

(Encyclopedia)erythema ĕrˌəthēˈmə [key], more or less diffuse redness of the skin due to concentration of an abnormally large amount of blood within the small vessels of the skin (hyperemia), as in burns. Ery...

menthol

(Encyclopedia)menthol, white crystalline substance with a characteristic pungent odor. It is derived from the oil of the peppermint plant, Mentha piperita (see mint), or prepared synthetically from coal tar. An alc...

river blindness

(Encyclopedia)river blindness or onchocerciasis, disease caused by the parasitic nematode worm Onchocerca volvulus. The worm larvae are transmitted by the bites of blackflies (genus Simulium) that live in fast movi...

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...

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...

nail, in anatomy

(Encyclopedia)nail, in anatomy, the horny outgrowth shielding the tip of the finger and the toe in humans and most other primates. The nail consists of dead cells pushed outward by dividing cells in the root, a fol...

boil

(Encyclopedia)boil or furuncle fyo͝orˈŭngkəl [key], tender, painful inflammatory nodule in the skin, which becomes pustular but with a hard center (see abscess). It may be caused by any of various microbes, the...

Hawkes, John

(Encyclopedia)Hawkes, John (John Clendennin Burne Hawkes, Jr.), 1925–98, American writer, b. Stamford, Conn., grad. Harvard, 1949. He taught English at Brown Univ. after 1958. Hawkes is considered one of the most...