Category: N
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National health and nutrition examination survey (NHANES)
Conducted by the National Center for Health Statistics (NCHS), Centers for Disease Control and Prevention, designed to collect information about the health and diet of people in the United States. A comprehensive population survey that included a detailed dietary questionnaire from which intakes were calculated in a sample of over 10,000 adults. Data collected at…
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National Center for Health Statistics (NCHS) standards
Tables of height and weight for age used as reference values for the assessment of growth and nutritional status of children, based on data collected by the US National Center for Health Statistics in the 1970s. The most comprehensive such set of data, and used in most countries of the world.
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Nasogastric tube
Fine plastic tube inserted through the nose and thence into the stomach for enteral nutrition. A tube passed through the nose into the stomach. The tube inserted through the nose and ending in the stomach that carries liquid nourishment. Tube passed into the stomach through the nose used to aspirate stomach contents and secretions or…
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Naphthoquinone
The chemical ring structure of vitamin K; the various vitamers of vitamin K can be referred to as substituted naphthoquinones.
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Nano
Prefix for units of measurement, one thousand-millionth part (i.e. 10¯9), symbol n.
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Nicotine
Abrupt cessation of, or reduction in, nicotine use induces any combination of the following: dysphoric or depressed mood, insomnia, irritability or anger, anxiety, difficulty in concentrating, restlessness, decreased heart rate, and increased appetite or weight gain. A chemical found in tobacco, responsible for some of the physiological effects of smoking. The main alkaloid substance found…
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Narcissistic personality disorder
Characterized by a pervasive pattern of grandiosity in fantasy or behavior and an excessive need for admiration. Manifestations may include having an exaggerated sense of self-importance, having a feeling of being so special that one should associate only with other special people, exploiting others to advance one’s own ends, lacking empathy, and believing that others…
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Nystagmus
Abnormal movements of the eyeballs; side to side (horizontal), up and down (vertical), or circular (rotary). Such movements suggest organic pathology of the central nervous system (CNS) or of the oculomotor, trochlear, or abducens cranial nerves. Seen in toxic states such as intoxication with alcohol, sedative-hypnotics, anxiolytics, or phencyclidine (PCP). Rhythmic, involuntary movement of the…
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Nymphomania
Abnormal and excessive need or desire in a woman for sexual intercourse; known as satyriasis in men. May be of psychological or organic etiology. A rare phenomenon involving uncontrollable desire of a woman for sexual fulfillment. A true nymphomaniac will seek sexual gratification no matter what the consequences may be. An obsessive sexual urge in…
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Nyctophobia
The fear of night. Fear of the dark. It is common in children and not unusual in normal adults.