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Tissue, definition

Several additional terms related to the absorption of x-radiation require definition energy of a x-ray photon is properly represented in joules but more conveniently reported in eV fluence is the sum of the energy in a unit area intensity or flux is the fluence per unit time and the exposure is a measure of the number of ions produced in a mass of gas. The unit of exposure in medicine is the Rn ntgen, R, defined as the quantity of radiation required to produce 2.58 x C/kg of air. The absorbed dose for a tissue is a measure of energy dissipated per unit mass. The measure of absorbed dose most... [Pg.49]

Tb allium, which does not occur naturaHy in normal tissue, is not essential to mammals but does accumulate in the human body. Levels as low as 0.5 mg/100 g of tissue suggest thallium intoxication. Based on industrial experience, 0.10 mg /m of thallium in air is considered safe for a 40-h work week (37). The lethal dose for humans is not definitely known, but 1 g of absorbed thallium is considered sufficient to kHl an adult and 10 mg/kg body weight has been fatal to children. In severe cases of poisoning, death does not occur earlier than 8—10 d but most frequently in 10—12 d. Tb allium excretion is slow and prolonged. For example, tb allium is present in the feces 35 d after exposure and persists in the urine for up to three months. [Pg.470]

Chemical Pathology. Also referred to as clinical chemistry, this monitoring procedure involves the measurement of the concentration of certain materials in the blood, or of certain enzyme activities in semm or plasma. A variety of methods exist that allow (to variable degrees of specificity) the definition of a particular organ or tissue injury, the nature of the injurious process, and the severity of the effect (76). [Pg.236]

From the practical point of view, the principal variation of environment which is definitely under the control of the cultivator, is, of course, the alteration in the composition of the soil, which is brought about by scientific manuring, llie analysis of fruits and vegetables will give the ordinary agriculturist much information as to the necessary mineral ingredients to be added to the soil but in the case of essential oils, the conditions are entirely different. The various parts of the plant tissue are affected in different ways by the same mineral salts, and successful development of the fruit or any other given part of the plant may have little or no relationship with the quantity or quality of essential oil produced. So that it is only by actual distillations of the plant, or portion of the plant, coupled with an exhaustive examination of the essential oil, that informative results can be obtained. [Pg.3]

The definition of an overlap syndrome dictates that the criteria for diagnosis of both disorders (in the present context, of PM/DM and of some other connective tissue disorder), are fulfilled. It is not unexpected that those syndromes which overlap with PM/DM are also either known autoimmune conditions or ones in which an autoimmune basis is strongly suspected. The association of these disorders with PM/DM syndromes may not materially alter the basic histopathological featmes expected in PM/DM but some differences may be identifiable. The disorders most frequently associated with an overlap syndrome are rheumatoid arthritis, systemic lupus erythematosis, scleroderma, and mixed connective tissue disease. [Pg.332]

In conclusion, it is apparent that the lack of definitive methods for assessment of free radicals in muscle and other tissues inhibits clear conclusions to be drawn concerning the relevance (or lack of relevance) of these substances in muscle pathology. In particular, the relevance of free radicals to the deficits in muscle function (fatigue and damage), which occur with exercise, is still unclear despite extensive study. This and other areas require much further examination. [Pg.180]


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See also in sourсe #XX -- [ Pg.159 ]




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