نتایج جستجو برای: 137
تعداد نتایج: 13875 فیلتر نتایج به سال:
Measurements of fallout radioactivity in Greenland in 1977 are reported. Strontium-90 (and Cesium-137 in most cases) was determined in samples of precipitation, sea water, vegetation, animals, and drinking water. Estimates are given of the mean contents of 90Sr and 137Cs in the human diet in Greenland in 1977.
Data from published studies and World Wide Web sources were combined to develop a regression model to predict (137)Cs concentration ratios for saltwater fish. Predictions were developed from 1) numeric trophic levels computed primarily from random resampling of known food items and 2) K concentrations in the saltwater for 65 samplings from 41 different species from both the Atlantic and Pacific...
سرعت فرسایش و رسوب خاک در بیشتر قسمت های جهان نسبت به سرعت طبیعی در اثر فعالیت های انسانی در حال افزایش است. پژوهشگران در سراسر دنیا از دیرباز در پی این بوده اند تا با استفاده از روش های مختلف بتوانند میزان فرسایش را در اراضی مختلف محاسبه نمایند. تکنیک های کمی و کیفی متعددی برای محاسبه فرسایش و رسوب در جهان وجود دارد. بیشتر این تکنیک ها الگوی مکانی از انتقال خاک و رسوب ذرات فرسایش یافته را ایجا...
Hreinn Stefansson1,3, Agnar Helgason1,3, Gudmar Thorleifsson1, Valgerdur Steinthorsdottir1, Gisli Masson1, John Barnard2, Adam Baker1, Aslaug Jonasdottir1, Andres Ingason1, Vala G Gudnadottir1, Natasa Desnica1, Andrew Hicks1, Arnaldur Gylfason1, Daniel F Gudbjartsson1, Gudrun M Jonsdottir1, Jesus Sainz1, Kari Agnarsson1, Birgitta Birgisdottir1, Shyamali Ghosh1, Adalheidur Olafsdottir1, Jean-Bap...
The tooth structure preservation is the best way to postpone more invasive therapies. Especially in young patients more conservative techniques should be applied. Bonded porcelain veneers and even more the direct composite restorations, are the two therapeutic procedures that require the fewer sacrifice of dental tissue, finalized to the optimal recovery of aesthetic and functional outcome. Alt...
Background: There is some evidence suggesting a close relationship between polyunsaturated fatty acids (PUFAs) and renal inflammation and fibrosis, which are crucial stages in chronic kidney disease. Methods: To verify the role of PUFAs in renal fibrosis processes, we investigated the effects of eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA) and arachidonic acid (AA) on the gene expres...
A range of individual nutrients and foods have been suggested to increase obesity risk in childhood, but the evidence is inconsistent. Dietary patterns that summarise the whole diet may, however, be more informative. The aim of the present paper was to systematically review the current evidence pertaining to overall dietary patterns in childhood and later obesity risk. Studies eligible for revi...
Volume 29, Number 3, May/June 1997 1980, the rate increased by 61% among adolescents, by 69% among women aged 20–24, by 67% among 25–29 year-olds and by 82% among women aged 30–34.2 Indeed, the rates for these latter groups have continued to rise since 1991, even as the birthrate among adolescents has stabilized and turned slightly downward. As a result of these trends, nonmarital births now ac...
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