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131.
Measurement of the microvillar enzymes, γ-glutamyltranspeptidase (GGTP), aminopeptidase M (APM) and alkaline phosphatase (ALP), in amniotic fluid supernatant has been proposed as a method for the early prenatal diagnosis of cystic fibrosis. The activities of these enzymes in a series of other fetal abnormalities have now been examined. GGTP activities were below the 5th percentile in 28 out of 54 cases of trisomy 21 and 9 of 14 cases of trisomy 18, while APM values were below this cut-off in 26 of 54 cases of trisomy 21 and 8 of 14 cases of trisomy 18. Abnormal ALP isoenzyme ratios were found in 6 of 54 cases of trisomy 21 and 4 of 14 cases of trisomy 18. If prenatal cytogenetic studies are routinely carried out on amniotic fluid cells, the occasional confounding effect of abnormal microvillar enzymes associated with fetal trisomies rather than with cystic fibrosis should be avoided.  相似文献   
132.
广州市实施I/M简易瞬态工况检测方法的环境效果分析   总被引:2,自引:0,他引:2  
采用简易瞬态工况法对在用车进行检测,能够更为有效地筛选高排放车辆.2007—2009年广州市轻型汽油车的简易瞬态工况法的初检数据表明,国Ⅰ排放标准实施以前(简称"国Ⅰ前")车辆和国Ⅰ及以后排放标准车辆排放超限值比例分别为20.1%和17.6%.简易瞬态工况法复检数据得到的国Ⅰ前和国Ⅰ及以后车辆经维护后能够达标的比例分别为76.0%和64.7%,且经过有效维护后超标车辆的平均排放水平有较大比例的削减.同时,采用修正的MOBILE5模型对广州市轻型汽油车排放进行模拟.结果发现,广州市2009年轻型汽油车的CO、HC和NOx排放量分别为24.4×104、3.8×104和1.8×104 t.如果考虑I/M制度实施及实际执行率,复检不达标车辆在全部淘汰情景下,2009年广州市轻型汽油车排放的CO、HC和NOx分别能削减4.20×104、0.58×104和0.15×104 t,占全部轻型汽油车的削减比例分别为17.2%、15.3%和8.2%;而在全部置换为国Ⅳ新车情景下,3种污染物分别能削减4.12×104、0.57×104和0.14×104 t,削减比例分别为16.9%、15.0%和8.0%.国Ⅰ前及国Ⅰ车辆对CO和HC削减量的贡献达到90%左右,对NOx削减量的贡献也在85%左右.  相似文献   
133.
王涛  龙恩深  袁琦  陈红轻 《灾害学》2010,25(1):139-143
帐篷在救灾过程中发挥着巨大作用,但内部热湿环境比较恶劣,空温、内表面均温都超出了人体所能适应的范围,严重影响灾区群众的身心健康。汶川8.0级地震的灾区群众利用一些土方法如搭遮阳网等对帐篷进行了改进。通过对门窗封闭和门窗开启情况下改进的帐篷与普通帐篷室内温度、相对湿度、内表面均温的对比,发现采取一些简单的改进方法能取得意想不到的效果,可以有效的降低帐篷内部温度和内表面均温,从而降低帐篷内的当量有效温度,改善帐篷内居住环境。从而得到很大启示,提出了一些在帐篷使用过程中的改善措施以及结构改进的方向。  相似文献   
134.
应用体外叙利亚金黄鼠胚胎细胞(SHE)二阶段恶性转化试验,村由太湖水中提取的微囊藻粗毒素(MRT)的促癌作用进行了研究。结果表明,微囊藻粗毒素可明显增强由低剂量3-甲基胆蒽(MCA)启动的细胞恶性转化作用,所形成的转化率明最高于阴性对照组(P0<0.01),并呈良好的剂量反应关系,但用微囊藻粗毒素作启动剂,以典型的促癌剂豆蔻酸乙酸大戟二萜醇酯(TPA)促进后未见恶性转化率升高。提示微囊藻粗毒素可能是环境中一种新的促癌剂,是饮致癌的重要因素之一。  相似文献   
135.
用1971-2000年的30年逐日降水量资料,按旬统计汶川地震重灾县5-12月各旬的雨日、中雨日、大雨日、暴雨日的平均日数和气候概率,根据地震重灾区实际地质环境条件,降低强降雨强度条件,基于模糊综合评判法,按照最大隶属度原则对汶川特大地震重灾区的39个县进行地质灾害时空气候风险评估。结果表明:重灾区的地质灾害气候风险指数值存在两个高值期间,一个是5月中旬至7月上旬,另一个是8月下旬至9月下旬。而10月下旬至次年4月,重灾区降雨明显减少,绝大部分地区没有地质灾害气候风险;从地域分布来看,高风险区域主要集中在重灾区的西部和中部,风险等级为3~4级(风险较大或很大),东部地区风险等级为1~2级(中等风险或风险较小),但7月下旬高等级风险区位置集中在重灾区的南部和东部。  相似文献   
136.
Since the liberalisation of its investment regime in the 1990s, Argentina has seen a rise in foreign direct investment into large-scale exploration and exploitation of mineral resources. However, many social groups (local communities, grassroots movement and the church) often strongly oppose new mining projects on the grounds of environmental, ethical and economic concerns. In a situation marked by widespread conflict, mining companies continue operating and develop Corporate Social Responsibility (CSR) initiatives which are often promoted as a means of contributing to the sustainability and development of the nation. The paper develops a framework to highlight how the principles of stakeholder theory could be used as conceptual and practical guidance for conflict-resolution oriented CSR policies. The framework is further used to analyse two case studies of conflictive mining projects in Argentina. The paper explores how key stakeholders perceive contribution of CSR to welfare and the socio-economic development of mining communities and sustainable development of the nation. It demonstrates that institutional and social stakeholder networks often strongly oppose the idea of voluntary self-regulation implied by CSR in situations characterised by weak governance. Even though the CSR of companies could be improved in areas of corporate communication, transparency, stakeholder engagement and dialogue, it is not seen as a panacea for the social conflicts in the sector.  相似文献   
137.
Chung K  Lee I  Han JI 《Chemosphere》2012,86(4):415-419
As an effort to better utilize the microbial fuel cell (MFC) technology, we previously proposed an innovative MFC system named M2FC consisting of ferric-based MFC part and ferrous-based fuel cell (FC) part. In this reactor, ferric ion, the catholyte in the MFC part, was efficiently regenerated by the FC part with the generation of additional electricity. When both units were operated separately, the ferric-based MFC part produced approximately 1360 mW m−2 of power density with FeCl3 as catholyte and Fe-citrate as anolyte. The ferrous-based FC part with FeCl3 as catholyte and Fe-EDTA as anolyte displayed the highest power density (1500 mW m−2), while that with ferricyanide as catholyte and Fe-noligand as anolyte had the lowest power density (380 mW m−2). The types of catholytes and chelating complexes as anolyte were found to play important roles in the reduction of ferric ions and oxidation of ferrous ion. Linear sweep voltammetry results supported that the cathode electrolytes were electrically active and these agreed well with the M2FC reactor performance. These results clearly showed that ligands played critical role in the efficiency and rate for recycling iron ion and thus the M2FC performance.  相似文献   
138.
Over the last two decades, mining and mineral exploration companies have adopted various environmental management practices in response to society’s pressure for better environmental protection. The literature highlights a number of benefits and challenges for companies adopting environmental management practices with the Greek Mining and Mineral Industry (GMMI) facing similar issues. In order to analyze the challenges faced by the GMMI, a Strengths, Weaknesses, Opportunities and Threats (SWOT) analysis was conducted, which examined the strengths, weaknesses, opportunities and threats faced by the industry when adopting environmental management practices. The analysis prescribes policy recommendations both for the government and industry which, if adopted, could facilitate improved environmental performance.  相似文献   
139.
石墨炉原子吸收光谱法测定农产品中痕量铍   总被引:1,自引:0,他引:1  
采用石墨炉原子吸收光谱法测定农产品中痕量铍,比较了微波消解和电热板消解两种前处理方法,选择了基体改良剂。方法在0μg/L—4.00μg/L范围内线性良好,微波消解法和电热板消解法的检出限分别为0.002mg/kg和0.0002mg/kg,标样平行测定的RSD为2.4%—4.1%,农产品加标回收率为80.0%—95.0%。  相似文献   
140.
城市生活垃圾卫生填埋场渗滤液水量水质的确定   总被引:11,自引:2,他引:11  
冯明谦  李强 《四川环境》2001,20(2):52-54
本文论述了3种渗滤液水量预测法,推荐采用Q=CIA×10-3公式;介绍了确定渗滤液水质的方法;根据国内外渗滤液水质实测值,分析了水质特点,认为我国渗滤液浓渡呈增加趋势。  相似文献   
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