A plant species of the genus CHRYSANTHEMUM, family ASTERACEAE. The flowers contain PYRETHRINS, cinerolones, and chrysanthemines which are powerful contact insecticides. Most in the old Pyrethrum genus are reclassified to TANACETUM; some to other ASTERACEAE genera.
A broad category of sleep disorders characterized by either hypersomnolence or insomnia. The three major subcategories include intrinsic (i.e., arising from within the body) (SLEEP DISORDERS, INTRINSIC), extrinsic (secondary to environmental conditions or various pathologic conditions), and disturbances of circadian rhythm. (From Thorpy, Sleep Disorders Medicine, 1994, p187)
A mixture of isomeric tritolyl phosphates. Used in the sterilization of certain surgical instruments and in many industrial processes.
Aspects of health and disease related to travel.
The great peninsula of southwest Asia comprising most of the present countries of the Middle East. It has been known since the first millennium B.C. In early times it was divided into Arabia Petraea, the northwest part, the only part ever conquered, becoming a Roman province; Arabia Deserta, the northern part between Syria and Mesopotamia; and Arabia Felix, the main part of the peninsula but by some geographers restricted to modern Yemen. (From Webster's New Geographical Dictionary, 1988, p63)
The small mass of modified cardiac muscle fibers located at the junction of the superior vena cava (VENA CAVA, SUPERIOR) and right atrium. Contraction impulses probably start in this node, spread over the atrium (HEART ATRIUM) and are then transmitted by the atrioventricular bundle (BUNDLE OF HIS) to the ventricle (HEART VENTRICLE).