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821.
Histopathological changes in selenium-exposed fish 总被引:1,自引:0,他引:1
E M Sorensen J S Bell C W Harlan 《The American journal of forensic medicine and pathology》1983,4(2):111-123
Redear sunfish (Lepomis microlophus) were collected from Martin Lake in east Texas. For at least 8 months, 1 year earlier, aqueous selenium-laden effluent from man-made sources was released into this 5,000-acre reservoir (unpublished data). Redear sunfish from a reference lake, 8 km upstream, were collected for comparison to Martin Lake fish. The hepatopancreas (i.e., liver and associated, disseminated exocrine pancrease), mesonephros (i.e., kidney), gonads, heart, spleen, stomach, and gill arches were preserved for histopathological examination using optical and/or transmission electron microscopy. Livers from Martin Lake redear sunfish (which had accumulated approximately 20 ppm selenium in the liver) showed central necrosis, reduced quantities of rough endoplasmic reticulum and glycogen particles, and increased numbers of lysosome-like structures. Kidneys showed proliferative glomerulonephritis, and exocrine pancreas showed marked hypertrophy at the optical level. Ultrastructurally, architectural disorganization, reduced rough endoplasmic reticulum, increased cisternal space, and proliferation of smooth endoplasmic reticulum were evident. The stomach, spleen, gill, heart, and gonads showed no abnormalities. 相似文献
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Richard W. Wahl 《Journal of policy analysis and management》1982,1(4):496-511
The Consumer Price Index (CPI) is widely used to adjust wages and federal benefits as an offset to inflation, but the index contains substantial sources of bias as used for such purposes. For instance, these sources of bias, such as changes in the real cost of petroleum, the cost of environmental protection, and an inappropriate method for measuring homeownership costs, accounted for nearly half of the CPI increase in the year from November 1978 to November 1979. Because of the nature of the index, such biases will always be present, creating the risk that the CPI may be adding to the inflation that it is only supposed to measure. Therefore, a new index or indexes that are more appropriate for adjusting wages and benefits for inflation should be developed. 相似文献
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The techniques of thin-layer chromatography, gas chromatography with electron capture detection, and gas chromatography/mass spectrometry were used to analyze hand swab extracts for the presence of nitroglycerine. Both the amount of nitroglycerine transferred to the hands after handling commercial explosives and its persistence were measured. Gas chromatography-electron capture detection was found to be the most accurate and sensitive technique for making such determinations, especially if the extract was partially purified by thin-layer chromatography prior to analysis. The lowest limit of detection was 10 ng of nitroglycerine, and residues could be detected over 20 h after handling the raw explosive. 相似文献
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The bulk and surface refractive indices have been measured for 20 float window glasses, 20 non-float window glasses, 20 patterned window glasses and 20 toughened float windscreen glasses.The refractive index of the tin-contact surface of the float glasses was always greater than that of the bulk, typically by 0.002 (range 0.00053–0.00307). In contrast the refractive indices of the two surfaces and the bulk of the sheet window glasses were in agreement within accepted experimental error in each case. A number of patterned window glasses showed significantly different refractive indices between the plain and patterned surfaces, the largest difference obtained (0.00021) being an order of magnitude smaller than that found for a typical float glass.Nine of the 40 float glasses examined yielded abnormal fragments from the upper surface in the sense that they did not disappear at the match temperature of the bulk glass. The refractive index measured from these abnormal fragments for two of these glasses was lower than the refractive index from the bulk glass.The variation in the bulk refractive index for the sheet and float window glasses produced an estimated standard deviation (E.S.D.) of 1.2 × 10?5. However, the patterned glasses were nearly three times as variable (E.S.D. = 3.3 × 10?5) and the toughened float glasses were, on average, almost seven times as variable (E.S.D. = 8.0 × 10?5).The value of making surface as well as bulk refractive index measurements in routine casework is discussed in the light of the above results. 相似文献