| NK cell | Natural Killer cell |
|---|---|
| CNL | cardiolipin natural lecithin; chronic neutrophilic leukemia |
| e | base of natural logarithms, approximately 2.7182818285; egg transfer; ejection; electric charge; ele... |
| LGL-NK | large granular lymphocyte-natural killer |
| ln | natural logarithm |
natural purification (자정 작용
| natural language processing | Computer processing of a language with rules that reflect and describe current usage rather than prescribed usage. (12 Dec 1998) |
|---|---|
| natural mutation | A mutation which occurs by itself without first being affected by a mutagen, for example during the process of DNA replication. Spontaneous mutations arise at a remarkably constant rate. The rate that spontaneous mutations arise has been used as an evolutionary clock to estimate how closely related two (or more) separate species are to each other. (09 Oct 1997) |
| natural passive immunity | Immunity conferred by the mother on the foetus or newborn. (14 Nov 1997) |
| natural pigment | A naturally occurring coloured compound; absorbs light in the visible range of the electromagnetic spectrum. Compare: structural colour. Synonym: biochrome. (05 Mar 2000) |
| natural products | Naturally occurring compounds that are end products of secondary metabolism; often, they are unique compounds for particular organisms or classes of organisms. (05 Mar 2000) |
| natural selection | The hypothesis that genotype environment interactions occurring at the phenotypic level lead to differential reproductive success of individuals and hence to modification of the gene pool of a population. (18 Nov 1997) |
| immunity, natural | The capacity of a normal organism to remain unaffected by microorganisms and their toxins. It results from non-specific mechanisms such as genetic endowment, naturally occurring antiviral and bactericidal substances, phagocytosis, and constitutional factors such as body temperature, oxygen tension, and age. (12 Dec 1998) |
| killer cells, natural | Cells responsible for spontaneous cytotoxicity of a variety of tumour cells without prior immunization. These natural killer cells are found in non-immune humans and experimental animals and are thought by some to be the same as killer cells (killing by antibody-dependent cell cytotoxicity), but they can also kill in the absence of antibody. (12 Dec 1998) |
| attitude to death | Conceptual response of the individual to the various aspects of death, which are based on his psychosocial and cultural experience. (12 Dec 1998) |
| Black Death | <disease, organism> Yersinina pestis is a gram-negative, rod-shaped, faculatively anaerobic bacterial species in the family Enterobacteriaceae. It causes bubonic plaque, which is transmitted by rodent fleas. Historically known as the Black Plague, this disease devastated Europe and Asia in the 1300s. It still exists today and is characterised by sudden high fever, chills, excessively swollen and tender lymph nodes (buboes), followed by tissue bleeding and gangrene. Other complications include pneumonia and septicaemia. (12 Nov 1997) |
| brain death | Total cessation of brain function for 24 hours as manifested by absence of spontaneous movement, absence of spontaneous respiration, and absence of all brainstem reflexes. (12 Dec 1998) |
| rate, death | The number of deaths in the population divided by the average population (or the population at midyear) is the crude death rate. In 1994, for example, the crude death rate per 1,000 population was 8.8 in the united states, 7.1 in Australia, etc. A death rate can also be tabulated according to age or cause. (12 Dec 1998) |
| genetic death | Death of the bearer of a gene at any age before generating living offspring. May be compatible with good health and long life. See: genetic lethal. (05 Mar 2000) |
| maternal death | Death of a woman while pregnant or within 42 days after the termination of gestation, irrespective of the duration and site of pregnancy and the cause of death; two periods are recognised in the 42-day interval: period 1 includes day 1 to day 7; period 2 includes day 8 to day 42. Maternal death's are further classified as: (05 Mar 2000) |
| maternal death rate | The number of maternal deaths that occur as the direct result of the reproductive process per 100,000 live births. See: rate. See: maternal death. (05 Mar 2000) |