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The impact of atmospheric industrial emissions on secondary pollutant formation depends on many factors; one of the most important being the environmental setting in which the industry is located. The environmental setting affects an industry’s impact on ozone levels through both the air mass dispersion (a function of topography and wind patterns) and the emissions of organic volatile compounds (VOC) and nitrogen oxides (NO x ) in the area. This model-based study shows how the sensitivity of surface ozone changes with the choice of source location. For the analysis, seven points distributed along the Tinto–Guadalquivir Basin (in the Southwestern Iberian Peninsula) were selected. This area is characterized by the close proximity of natural environments and crop fields to cities, roads, and industrial areas with high NO x emissions. Natural VOC emissions represent more than 60% of the total non-methane volatile organic compounds emitted in the study area. The results reveal that the largest increases in ozone levels are produced when the industry is located both far away from NO x emission sources and near to biogenic VOC emissions. Furthermore, the highest increases over the hourly and 8-hourly maximums, as well as the highest accumulated daily values, are found in areas characterized by high VOC/NO x emission ratios and NO x sensitivity. The study of the recurrent meteorological patterns along with the distribution of chemical indicators of the O3–NO x –VOC sensitivity allows the determination of the industry’s geographical impact on ozone levels. This information enables air quality managers to decide the future location of an industry minimizing its impact on smog levels.  相似文献   
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Photooxidation of cumene (isopropylbenzene) and pyridine in dilute solution in natural waters gives products characteristic of reactions with alkylperoxy (RO(2).) and hydroxyl (HO.) radicals. On the basis of the rates of formation of the products, the average concentrations of RO(2). and HO. are estimated to be about 10(-9) and 10(-17) mole per liter, respectively. The concentration of RO(2). is large enough that, for some classes of reactive chemicals, oxidation can be an important process in natural waters.  相似文献   
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The immunohistochemical expression, tissue-specific and cell-specific distribution patterns of progesterone receptors (PR), growth hormone (GH) and insulin growth factor-I (IGF-I) have been studied in 22 cases of feline fibroadenomatous change (FFAC). PR and GH were detected in all cases and were distributed homogeneously throughout the lesion, while IGF-I was detected in 77% of the cases at the site of ductal budding. The simultaneous expression of PR, GH and IGF-I was detected in epithelial cells in 14 of 22 cases while PR and GH expression only was detected in epithelial cells in 11 cases. Cases that expressed GH and IGF-I without PR expression in the stroma were the most numerous. Double immunohistochemical staining showed the co-localisation of PR and GH in a subset of ductal epithelial cells located between basal/myoepithelial and luminal cells (probably undifferentiated stem cells). These results suggest that ligand-activated progesterone receptors may induce the local synthesis of GH which in turn may exert its proliferative action directly and also indirectly through the production of other growth factors, such as IGF-I, in an autocrine/paracrine manner.  相似文献   
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This article describes the treatment of single congenital portosystemic shunts (CPSs) (intrahepatic and extrahepatic) using an interventional radiology technique involving embolisation of anomalous vessels with percutaneous coils. Briefly, a multipurpose catheter was introduced into the caudal vena cava and then into the portosystemic shunt. An autoexpandable stent was placed in the caudal vena cava, next to the shunt, in order to avoid coil migrations, and a cobra-like vascular catheter was used to pass through the stent and to place the coils in the shunt. This technique was used for treatment of CPS in six dogs. The results indicate that percutaneous embolisation of a CPS using coils, a less invasive technique than the traditional surgical technique, may result in complete closure of the anomalous vessel without development of portal hypertension.  相似文献   
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