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A proton magnetic resonance spectroscopic method for determining disulfiram in the bulk drug product and in the formulated material was collaboratively studied. The method depends on the use of chloroform-d as a solvent and hexamethylcyclotrisiloxane as the internal standard. No interference from tablet excipients was observed. The method is rapid and specific. Eighteen laboratories analyzed duplicate samples of a bulk drug product, a 250 mg tablet composite, and a 500 mg tablet composite. The average per cent results and standard deviations were 99.7 +/- 1.4, 100.9 +/- 2.0, and 99.9 +/- 2.2, respectively. 相似文献
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Little information exists concerning the effects of long-term fungicide programs on the qualitative and quantitative characteristics of fusaria in turfgrasses and in turfgrass soils. These effects were studied on Poa pratensis L, turfgrasses at three locations, using 14 fungicides, one nematicide, and five mixed fungicide programs. Some fungicides increased the numbers of fusaria in soil and thatch, some had no effect, and others greatly reduced the numbers. Changes in Fusarium species' compositions occurred independently from the changes in propagule numbers. The proportion of Fusarium-colonized turfgrass crowns was generally higher in fungicide-treated than in nontreated turfgrasses. 相似文献
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This paper describes the main features of the Sangay wilderness area in the Ecuadorian Andes. It is a region of great diversity with life zones ranging from tundra to subtropical rain forest. The conservation value of the area is assessed and the feasibility of protection determined. Boundaries based mainly on the limits of human interference are put forward with management proposals for its establishment as a National Park. 相似文献
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D.F. Owen 《Biological conservation》1975,8(3):173-183
Concern about the apparent decline in butterfly populations has led to projects designed to obtain quantitative information on their abundance and diversity. Three methods of sampling communities of butterflies are suggested, and the use of a diversity index, β, is recommended. This index gives an estimate of the probability that an individual sampled at random from a community will be different from the previous individual sampled. Change and stability in diversity can be used as a guide for conservation and management programmes. 相似文献