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931.
Polychlorinated biphenyls (PCBs) were commercially produced between 1959 and 1984 in eastern Slovakia. Improper handling led to a highly contaminated local environment and high levels of PCBs in humans and wildlife in the Michalovce area. The aim of this study was to analyse serum for methylsulfonyl metabolites of PCB (MeSO(2)-PCBs) and DDE (3-MeSO(2)-DDE) in serum samples from pregnant women and in a selected number of paired cord blood samples to assess maternal sulfone levels and patterns, and transplacental transfer of these metabolites. The donating women were from two districts in eastern Slovakia. A liquid-liquid extraction method together with separation of substance groups and further clean-up on silica gel columns were applied prior to analysis by gas chromatography/mass spectrometry. 3-MeSO(2)-DDE was the major methyl sulfone in most of the samples followed by a yet not identified MeSO(2)-hexaCB, 4'-MeSO(2)-CB101, 4'-MeSO(2)-CB87 and 4-MeSO(2)-CB149. The women from the contaminated area had three times higher concentrations of the MeSO(2)-PCBs than women from the reference area. This is the first report on methyl sulfone metabolites of PCB and DDE in human cord serum. It is shown that these metabolites are transported through the placenta. The levels of MeSO(2)-PCBs in the maternal serum were about 1.5 times higher than in the corresponding cord serum on a lipid weight basis. For 3-MeSO(2)-DDE, the levels were about the same in maternal and cord serum. The difference in the maternal:cord ratio, comparing MeSO(2)-PCBs with 3-MeSO(2)-DDE might be due to differences in transport through the placenta caused by their different affinities for lipoproteins and plasma proteins.  相似文献   
932.
933.
In this work a quantitative analysis of the risk in the land transport of hazardous materials in Sicily has been executed. Risk calculation has been carried out using the TRAT-GIS code, a software for incidental and environmental risk assessment associated with the transport of dangerous substances and supported by a Geographical Information System (GIS). Results have been collected in a database, the GIS allows to display the risk maps.Risk analysis has been made on a regional scale, then some critical points have been analysed in detail. Comparisons between different typologies of transport and routes have been possible by means of the risk maps. In order to reduce the risk and improve the protection of citizens, some proposals have been analysed in these past years and some of them have been recently realized. In this study other proposals for the optimization of the transport system have been formulated, results have also permitted to evaluate the risk reduction after the future application of the Regional Transportation Plan for the Sicily.  相似文献   
934.
The main objective of this study is to quantify the potential overpressures due to Vapor Cloud Explosions (VCEs) and the potential gas buildup by using Computation Fluid Dynamics (CFD) for onshore or offshore facilities.A series of CFD simulations and analyses have been performed for the various vapor dispersion scenarios, covering different release rates and release locations. The overpressure that could result from the potential VCE is assessed by CFD simulation for the largest explosive transient gas cloud. The results from the analyses also comprise an extensive picture of probable leak scenarios having the potential to make an explosive gas cloud.The CFD analysis results could be applied to provide input for detailed risk-based design and risk analysis, to find safe and cost-optimal design against explosions.  相似文献   
935.
936.
Food and Environmental Virology - Roof-harvested rainwater (RHRW) is considered relatively clean water, even though the possible presence of pathogens in the water may pose human health risks. In...  相似文献   
937.
938.
Congenital diaphragmatic hernia is a rare disease associated with high mortality and morbidity. Antenatal ultrasound screening identifies more than 70% of cases, providing the opportunity for in utero referral to a tertiary care center for expert assessment and perinatal management. Additional genetic and morphologic assessment may be used to rule out associated anomalies. In isolated cases, the outcome may be predicted prenatally by medical imaging. The combination of lung size and liver herniation is a widely accepted method to stratify fetuses into groups with an increasing degree of pulmonary hypoplasia and corresponding mortality rates. Ultrasound measurement of the observed to expected lung-to-head ratio (o/e LHR) is most widely used. The o/e LHR is an independent predictor of survival and short-term morbidity. Finally, evaluation of stomach position has recently been introduced as an indirect method to estimate severity of the disease in left-sided defects, as it has been shown to correlate with the proportion of intrathoracic liver. Herein, we propose a protocol for the standardized ultrasound assessment of fetuses with isolated CDH and individualized prediction of neonatal outcome.  相似文献   
939.
940.
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