refractive index

index /in·dex/ (in´deks) pl. indexes, in´dices   [L.]

1. forefinger.

2. a unitless quantity, usually a ratio of two measurable quantities having the same dimensions, or such a ratio multiplied by 100.

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body mass index  (BMI) the weight in kilograms divided by the square of the height in meters, used in the assessment of underweight and obesity.

cardiac index  (CI) cardiac output per unit time divided by body surface area.

Colour Index  a publication of the Society of Dyers and Colourists and the American Association of Textile Chemists and Colorists containing an extensive list of dyes and dye intermediates. Each chemically distinct compound is identified by a specific number, the C.I. number, avoiding the confusion of trivial names used for dyes in the dye industry.

Index Medicus  a monthly publication of the National Library of Medicine in which the world's leading biomedical literature is indexed by author and subject.

mitotic index  the ratio of the number of cells in a population undergoing mitosis to the number not undergoing mitosis.

opsonic index  a measure of opsonic activity determined by the ratio of the number of microorganisms phagocytized by normal leukocytes in the presence of serum from an individual infected by the microorganism, to the number phagocytized in serum from a normal individual.

phagocytic index  the average number of bacteria ingested per leukocyte of the patient's blood.

Quetelet index  body mass i.

refractive index  the refractive power of a medium compared with that of air (assumed to be 1). Symbol n or n.

short increment sensitivity index  (SISI) a hearing test in which randomly spaced, 0.5-second tone bursts are superimposed at 1- to 5-decibel increments in intensity on a carrier tone having the same frequency and an intensity of 20 decibels above the speech recognition threshold.

therapeutic index  originally, the ratio of the maximum tolerated dose to the minimum curative dose; now defined as the ratio of the median lethal dose (LD50) to the median effective dose (ED50). It is used in assessing the safety of a drug.

vital index  the ratio of births to deaths within a given time in a population.

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refractive index

n.

Abbr. n The ratio of the speed of light in air or in a vacuum to the speed of light in another medium.

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refractive index,

a numeric expression of the refractive power of a medium as compared with that of air, which has a refractive index value of 1. The refractive index is related to the number, charge, and mass of vibrating particles in the material through which light is passing and may be used as a measure of the total solids in a solution.

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refractive index (RI) (rē·frakˑ·tiv inˑ·deks),

n a measurement of the bending of a light ray when moving from a less dense substance to a higher dense material. Measured by a refractometer.

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index

pl. indexes, indices [L.] the numerical ratio of measurement of any part in comparison with a fixed standard.

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index case

the first case of a disease in a group to be brought to the attention of the clinician.

Color index

a publication of the Society of Dyers and Colorists and the American Association of Textile Chemists and Colorists, containing an extensive list of dyes and dye intermediates. Each chemically distinct compound is identified by a specific number, the CI number, avoiding the confusion of trivial names used for dyes in the dye industry. The Royal Horticultural Society, London, produces a similar document to aid in the identification of flower colors.

erythrocyte i's

see erythrocyte indices.

index Medicus

a monthly publication of the National Library of Medicine, in which the world's leading biomedical literature is indexed by author and subject.

opsonic index

a measure of opsonic activity determined by the ratio of the number of microorganisms phagocytized by normal leukocytes in the presence of serum from an animal infected by the microorganism, to the number phagocytized in serum from a normal animal.

phagocytic index

the average number of bacteria ingested per leukocyte of the patient's blood.

production index

a method of expressing production compared with a potential or target.

refractive index

the refractive power of a medium compared with that of air (assumed to be 1).

therapeutic index

originally, the ratio of the maximum tolerated dose to the minimum curative dose; now defined as the ratio of the median lethal dose (LD₅₀) to the median effective dose (ED₅₀). It is used in assessing the safety of a drug.

index Veterinarius

a periodic listing of all publications in the veterinary literature by the Commonwealth Agricultural Bureaux, United Kingdom. Also available on on-line data search.

vital index

the ratio of births to deaths within a given time in a population.