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Huang Q Fang C Chen Y Wu X Ye T Lin Y Dong S 《Environmental science and pollution research international》2011,19(7):2506-2514
The prevalence of bisphenol A (BPA) in the environment has attracted increasing attention because of the toxicity of this manmade pollutant. However, the toxicity related to cardiac development remains largely unknown. In the present paper, we investigated the cardiac toxicity of BPA using marine medaka (Oryzias melastigma) embryos. At 2?days postfertilization (dpf), the embryos were continuously exposed to a low concentration of BPA (200?μg/L) for the whole embryonic stage. Heart rate and sinus venosus (SV)-bulbus arteriosus (BA) distance were measured under microscopy. The mRNA expression levels of genes were quantified by SYBR real-time RT-PCR, and hematoxylin and eosin (H&E) staining was used to examine the histology of fish larvae hearts. Neither the heart rate nor the SV-BA distance of the embryos was affected by BPA exposure. However, the mRNA expression levels of Na(+)-K(+)-ATPase, BMP4, COX-1, FGF8, GATA4, and NKX2.5 were all downregulated at the critical developmental stages (6 and 10?dpf). Interestingly, the mRNA expression levels of COX-2 and LERP were significantly upregulated at 10?dpf. The mRNA expressions of inflammation-related genes (TNFα, IL1β, SOD, and CCL11) were all significantly upregulated after exposure. Moreover, we found that both the body length and the body width decreased in the larvae after embryonic exposure to BPA. The distributed foci of inflammation were observed in the juveniles after 2?weeks' depuration. Exposure to BPA at embryonic stages could alter the expression of heart development-related genes and inflammation-related genes of O. melastigma. The larvae hatched from exposed embryos showed the foci of inflammation in the heart ventricles and the decrease of the body length and width. 相似文献
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In recent times, the quality of medical care has been continuously improving in medical institutions wherein patient-centred care has been emphasized. Failure mode and effects analysis (FMEA) has also been promoted as a method of basic risk management and as part of total quality management (TQM) for improving the quality of medical care and preventing mistakes. Therefore, a study was conducted using FMEA to evaluate the potential risk causes in the process of infectious medical waste disposal, devise standard procedures concerning the waste, and propose feasible plans for facilitating the detection of exceptional cases of infectious waste. The analysis revealed the following results regarding medical institutions: (a) FMEA can be used to identify the risk factors of infectious waste disposal. (b) During the infectious waste disposal process, six items were scored over 100 in the assessment of uncontrolled risks: erroneous discarding of infectious waste by patients and their families, erroneous discarding by nursing staff, erroneous discarding by medical staff, cleaning drivers pierced by sharp articles, cleaning staff pierced by sharp articles, and unmarked output units. Therefore, the study concluded that it was necessary to (1) provide education and training about waste classification to the medical staff, patients and their families, nursing staff, and cleaning staff; (2) clarify the signs of caution; and (3) evaluate the failure mode and strengthen the effects. 相似文献
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In recent years, the issue of environmental protection has received considerable attention. This paper adds to the literature by investigating a scheduling problem in the manufacturing of a glass recycling factory in Taiwan. The objective is to minimize the sum of the total holding cost and loss cost. We first represent the problem as an integer programming (IP) model, and then develop two heuristics based on the IP model to find near-optimal solutions for the problem. To validate the proposed heuristics, comparisons between optimal solutions from the IP model and solutions from the current method are conducted. The comparisons involve two problem sizes, small and large, where the small problems range from 15 to 45 jobs, and the large problems from 50 to 100 jobs. Finally, a genetic algorithm is applied to evaluate the proposed heuristics. Computational experiments show that the proposed heuristics can find good solutions in a reasonable time for the considered problem. 相似文献
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为深入研究唐山市老自行车厂场区六价铬污染机理和确定治理方案,本文通过一系列的浸泡和土柱试验,查明了六价铬在场地包气带中的污染原理和硫酸亚铁还原固定治理土壤六价铬污染的可行性与相关参数。试验结果表明:污染场地内包气带中六价铬的运移主要受吸附和解析作用的控制。使用PH值为3.0,质量浓度为2.4%的硫酸亚铁溶液作为治理药剂,可将污染场地包气带中93.24%的六价铬去除。 相似文献
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泥石流堵塞坝溃决模式实验 总被引:4,自引:1,他引:3
为了研究泥石流堵塞坝溃决的模式,采用模型实验对堵塞坝溃决的过程进行模拟,实验历时2个月,共13组.实验中,通过改变主沟的水力参数和坝体参数研究泥石流堵塞坝溃决的全过程,并作了相关记录.通过对理论和实验数据的分析,泥石流堵塞坝的溃决形式有3种:冲刷溃决、有表面流的泥石流堆积体水力再启动、没有表面流的泥石流堆积体重力再启动.讨论了冲刷溃决中颗粒启动和有面流泥石流水力再启动的临界条件,并分析了启动流速u0和颗粒粒径D之间的关系;分析了泥石流重力再启动时堵塞坝坡面破坏的一般形式和特征;通过实验数据对不同溃决形式的溃决条件进行了验证,结果比较吻合. 相似文献