# dose

(redirected from effective dose)
Also found in: Dictionary, Thesaurus, Medical, Acronyms, Wikipedia.
Related to effective dose: Effective dose 50

## dose

1. Med a specific quantity of a therapeutic drug or agent taken at any one time or at specified intervals
2. Physics the total energy of ionizing radiation absorbed by unit mass of material, esp of living tissue; usually measured in grays (SI unit) or rads
3. a small amount of syrup added to wine, esp sparkling wine, when the sediment is removed and the bottle is corked
Collins Discovery Encyclopedia, 1st edition © HarperCollins Publishers 2005
The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.

## Dose

the energy of ionizing radiation absorbed by a unit of mass of irradiated matter (the absorbed dose Da). The absorbed energy is expended in the heating and the chemical and physical transformation of matter. The magnitude of the dose depends on the type of radiation (for example, X-ray or neutron flux), the energy of its particles, the density of their flux, and the composition of the irradiated matter. All other things being equal, the longer the time of irradiation, the greater the dose. Thus, doses accumulate with time. The dose per unit time is called the dose rate.

In addition to the absorbed dose there are the concepts of the exposure dose and the dose equivalent. The exposure dose, a measure of the ionization of air under the action of Xand y-radiation, is measured by the number of charges formed. Coulombs per kg is the unit of exposure dose in the system. An exposure dose of 1 coulomb per kg means that the total charge of all ions of the same sign formed in one kilogram of air is equal to one coulomb. The roentgen is a subsidiary that is widely used for exposure dose; 1 roentgen = 2.57976 x 10-4 coulombs per kg, which corresponds to the formation of 2.08 x 109 pairs of ions in 1 cu cm of air (at 0°C and 760 mm mercury). In order to create that number of ions it is necessary to expend energy equal to 0.114 ergs per cu cm, or 88 ergs per g. Thus, 88 ergs per g is the energy equivalent of the roentgen. The absorbed dose of X-radiation or y radiation in any substance can be calculated from the magnitude of the exposure dose. In order to do this it is necessary to know the composition of the substance and the photon energy.

Thus, the radiation danger to which a human being is subjected under any form of radiation corresponds to the same magnitude of dose equivalent. Natural sources of ionizing radiation (cosmic rays, the natural radioactivity of soil, water, air, and the human body) produce an average equivalent dose rate of 125 millirems per year. A dose equivalent of 400-500 rems received in a short time during irradiation of the whole body may, without special treatment, lead to death. However, the same dose equivalent received evenly during the course of one’s life leads to no perceptible changes. A dose equivalent of 5 rems per year is considered the maximum permissible exposure (MPE) in occupational irradiation.

The minimum dose of γ-radiation that will suppress the reproductive capacity of certain cells after a single irradiation is 5 rems. Inceptive changes in the blood are observed with prolonged daily doses of 0.02-0.05 rems, tumor formation, with 0.11 rems. The long-term consequences of irradiation are judged according to the increase in the frequency of mutation in the offspring. The dosage that will double the frequency of spontaneous mutation in man probably does not exceed 100 rems per generation. With local irradiation—that is, for the purpose of treating malignant tumors—high doses (6,000-10,000 rems in three or four weeks) of X-radiation or γ-radiation are used (carefully shielding the rest of the body).

Radiobiology distinguishes the following doses that lead sooner or later to death in animals: a dose that causes the death of 50 percent of the animals in 30 days (a lethal dose— LD30/50) with single-exposure unilateral X-radiation or γ-radiation is 300 rems for guinea pigs and 1,000 rems for rabbits; the minimum absolute lethal dose (MALD) with general γ-radiation is approximately 600 rems for man. With increases in dosage, the survival time is reduced to 2.8-3.5 days; further increases in dosage do not change that period. Only doses higher than 10,000-20,000 rems shorten the survival time to one day, and with subsequent irradiation, to a few hours. With a dose of 15,000-25,000 rems, cases of “death under the ray” are noted. Particular forms of radiation injury correspond to each dosage range. A number of invertebrate animals, plants, and microorganisms have considerably lower sensitivity.

Dosimeters are used in measuring radiation doses in order to predict radiation effects.

### REFERENCES

GOST 8848-63: Edinitsy radioaktivnosti i ioniziruiushchikh izluchenii. Moscow, 1964.
GOST 12631-67. Koeffitsient kachestva ioniziruiushchikh izluchenii. Moscow, 1967.
Ivanov, V. I. Kurs dozimetrii, 2nd ed. Moscow, 1970.
Golubev, B. P. Dozimetriia i zashchita ot ioniziruiushchikh izluchenii, 2nd ed. Moscow, 1971.

V. I. IVANOV and N. G. DARENSKAIA

## dose

[dōs]
(medicine)
The measure, expressed in number of roentgens, of a property of x-rays at a particular place; used in radiology.
(nucleonics)
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.
References in periodicals archive ?
(10) Similar minimal effective doses can be determined for serotonin-reuptake inhibiting (SRI) antidepressants (Table 2, (5) page 12).
In our study we were able to decrease the effective dose without losing any important findings that may affect the diagnoses.
Effective dose: a flawed concept that could and should be replaced: comments on a paper by D J Brenner (Br J Radiol 2008; 81: 521-3).
In Table 2, the calculated values of absorbed dose rate, radium equivalent activity, the external hazard index and annual effective dose equivalent were found to be higher for smaller grain sizes except for sample XI74, where the absorbed dose rate, radium equivalent activity and annual effective dose equivalent were slightly higher for grain sizes <2 mm and >1 mm, compared to grain size <1 mm and >0.5 mm.
Poppy plant extract doses causes longer seizure duration that the most effective dose is 50 mg/kg mice, which have increased seizure duration up to 198 1275 seconds, comparable to dose of 500 mg/kg of rosemary extract [2].
From the results it can be concluded that the total effective dose rate is less than 1 mSv per year in dwellings constructed from the building materials measured in the course of the present study.
The experts say reviewing these guidelines is essential, to ensure all children who require penicillin are receiving effective doses.
Myocardial perfusion imaging accounted for almost a quarter of the total effective dose (22%).
The most effective dose identified in case of normal and mild diabetic cases used for assessing antidiabetic effect in severely diabetic models based on FBG and PPG, urine sugar (US) and body weight (bw) (5,6).
Thus, in our article, we should have either listed doses in terms of effective dose (using Sv or mrem) or in terms of organ dose (using Gy or mrad).
The dosages and potency of intravenous mephentermine for prevention of post-spinal hypotension are not available in English literature This study was designed to determine the minimum effective dose ([ED.sub.50]) of mephentermine and to compare its potency with that of ephedrine for prevention of post-spinal hypotension in parturients undergoing caesarean section.

Site: Follow: Share:
Open / Close