固定化细胞技术在重金属废水处理中的应用研究进展

作为生物吸附技术的一种,固定化细胞技术用于重金属废水处理虽然时间不长,但已表现出良好的应用前景.通过分析固定化细胞技术的概念、固定化方法、可利用生物种类、吸附机理及其在生产实践中的应用情况,探讨了该技术目前存在的问题及研究方向.     

人类活动对生态系统服务功能的影响

生态系统服务功能是人类可持续发展的基础,但是人类在利用生态系统提供自然资源和生存环境两个方面的多种服务功能的同时,也在强烈影响生态系统的服务功能。除部分人类活动有利于生态系统服务功能的稳定与提高外,更多地则导致了一系列危及自身生存与发展的生态环境危机与灾难。目前,生态系统服务功能受到人类活动影响的后果已成为全球面临的日益突出的重大问题和人类社会共同关注的焦点,因而人类活动对生态系统服务功能的影响愈加受到人们的重视。论文介绍了生态系统服务功能的定义,阐述了生态系统服务功能的内涵,重点分析了人类活动影响生态系统服务功能的类型、人类活动对生态系统服务功能的影响及变化趋势。在此基础上,对尚待进一步研究的内容提出了建议。     

南充城市人居环境质量综合评价研究

介绍了人后环境的定义,并根据全面性、以人为本、可操作性、相对独立性的原则选取评价指标和构建指标体系.采用层次分析法对各指标和子系统赋予不同的权重,利用综合加权求和的方法得出该生态示范区的社会经济,基础设施和公共服务设施,生态环境以及人居环境在1999年和2000年的综合评价指教,对比人居环境1999年和2000年的评价指数,从而得出南克城市人居环境的指教在增大,状况是在不断改善,并从不同的角度给南克城市人居环境建设提出了一些建议,比如:因地制宜,采用多种投资方式加快城市基础设施和公共服务设施建设;优化城市布局,改善能源结构,加大环境治理投资,改善生态环境;加大宣传力度,提高城市可持续管理意识;坚持以人为本,搞好城市人居环境的规则和设计改善措施.     

Natural formation and degradation of chloroacetic acids and volatile organochlorines in forest soil--challenges to understanding

- DOI: http:/dx.doi.org/10.1065/espr2005.06.262 Goal, Scope and Background The anthropogenic environmental emissions of chloroacetic acids and volatile organochlorines have been under scrutiny in recent years because the two compound groups are suspected to contribute to forest dieback and stratospheric ozone destruction, respectively. The two organochlorine groups are linked because the atmospheric photochemical oxidation of some volatile organochlorine compounds is one source of phytotoxic chloroacetic acids in the environment. Moreover, both groups are produced in higher amounts by natural chlorination of organic matter, e.g. by soil microorganisms, marine macroalgae and salt lake bacteria, and show similar metabolism pathways. Elucidating the origin and fate of these organohalogens is necessary to implement actions to counteract environmental problems caused by these compounds. Main Features While the anthropogenic sources of chloroacetic acids and volatile organochlorines are relatively well-known and within human control, knowledge of relevant natural processes is scarce and fragmented. This article reviews current knowledge on natural formation and degradation processes of chloroacetic acids and volatile organochlorines in forest soils, with particular emphasis on processes in the rhizosphere, and discusses future studies necessary to understand the role of forest soils in the formation and degradation of these compounds. Results and Discussion Reviewing the present knowledge of the natural formation and degradation processes of chloroacetic acids and volatile organochlorines in forest soil has revealed gaps in knowledge regarding the actual mechanisms behind these processes. In particular, there remains insufficient quantification of reliable budgets and rates of formation and degradation of chloroacetic acids and volatile organochlorines in forest soil (both biotic and abiotic processes) to evaluate the strength of forest ecosystems regarding the emission and uptake of chloroacetic acids and volatile organochlorines, both on a regional scale and on a global scale. Conclusion It is concluded that the overall role of forest soil as a source and/or sink for chloroacetic acids and volatile organochlorines is still unclear; the available laboratory and field data reveal only bits of the puzzle. Detailed knowledge of the natural degradation and formation processes in forest soil is important to evaluate the strength of forest ecosystems for the emission and uptake of chloroacetic acids and volatile organochlorines, both on a regional scale and on a global scale. Recommendation and Perspective As the natural formation and degradation processes of chloroacetic acids and volatile organochlorines in forest soil can be influenced by human activities, evaluation of the extent of this influence will help to identify what future actions are needed to reduce human influences and thus prevent further damage to the environment and to human health caused by these compounds.     

一种新去整合素Adinbitor的表达、序列分析及其对C6神经胶质瘤细胞凋亡的诱导

Adinbitor为一通过基因工程方法获得的来自于中国白眉蝮蛇毒腺的去整合素家族的新成员 .从蝮蛇毒腺中提取总RNA进行RT -PCR扩增 ,获得了 2 19bp的白眉蝮蛇去整合素基因 .cDNA测序及由此推导的氨基酸序列结果显示 ,Adinbitor为含有 73个氨基酸的多肽 ,其中包括 12个半胱氨酸 ,并具有去整合素的特征模序 -RGD .对此去整合素基因进行克隆、转化与诱导后 ,得到了该蛋白的可溶性高效表达 .经组氨酸亲和层析纯化 ,获得了分子量Mr为 9×10 3 的均质融合蛋白 ,并将其命名为adinbitor.序列分析表明 ,adinbitor与已发表于GENBANK上的整合素序列有很高的同源性 ,其中同源性最高的是南韩的saxatilin ,二者的蛋白质同源性高达 91.78% .活性测定结果表明 ,Adinbitor能有效地诱导神经胶质瘤细胞C6的细胞凋亡 ,有希望成为一种抗癌新药 .图 5参 15     

Salvage Logging, Ecosystem Processes, and Biodiversity Conservation

Abstract:  We summarize the documented and potential impacts of salvage logging—a form of logging that removes trees and other biological material from sites after natural disturbance. Such operations may reduce or eliminate biological legacies, modify rare postdisturbance habitats, influence populations, alter community composition, impair natural vegetation recovery, facilitate the colonization of invasive species, alter soil properties and nutrient levels, increase erosion, modify hydrological regimes and aquatic ecosystems, and alter patterns of landscape heterogeneity. These impacts can be assigned to three broad and interrelated effects: (1) altered stand structural complexity; (2) altered ecosystem processes and functions; and (3) altered populations of species and community composition. Some impacts may be different from or additional to the effects of traditional logging that is not preceded by a large natural disturbance because the conditions before, during, and after salvage logging may differ from those that characterize traditional timber harvesting. The potential impacts of salvage logging often have been overlooked, partly because the processes of ecosystem recovery after natural disturbance are still poorly understood and partly because potential cumulative effects of natural and human disturbance have not been well documented. Ecologically informed policies regarding salvage logging are needed prior to major natural disturbances so that when they occur ad hoc and crisis-mode decision making can be avoided. These policies should lead to salvage-exemption zones and limits on the amounts of disturbance-derived biological legacies (e.g., burned trees, logs) that are removed where salvage logging takes place. Finally, we believe new terminology is needed. The word salvage implies that something is being saved or recovered, whereas from an ecological perspective this is rarely the case.     

Attrition and housing improvements: A study of post-disaster housing after three years

This research is part of an effort to monitor houses built for victims of hurricane Fifi in 1975. After 3 years (1978) we interviewed the residents to determine the rate of continued occupancy and the amount of housing improvement and the correlates of both. We found that a significant number of small families, Protestants, and families that had not participated in the construction of the housing had moved. From what we could determine, moving was primarily related to seeking work and improving one's financial position.
Nearly 90% of the permanent occupants had improved their houses with either indigenous or manufactured materials. Non-improvement of houses was concentrated among families with few members. The largest number of unimproved houses was located in the project that sewed the poorest victims and contained the cheapest housing.     

户外端子箱操作人因可靠性及其风险评价*

为正确评价人为因素对户外端子箱失效的影响,利用CREAM(Cognitive Reliability and Error Analysis Method)模型的共同绩效条件分析端子箱操作过程中人的行为机理以及行为可靠性因素;应用SLIM(Success Likelihood Index Method)模型计算人为失误概率,并采用比例故障模型计算户外端子箱自身的故障率;以某断路器端子箱为例进行验证。结果表明:研究案例的人为失误概率为1.56%,设备故障率为0.84%,系统的风险值为10.7%,系统的风险等级为3;从概率的角度说明事故发生原因中人为因素的影响更大。因此,从行为可靠性影响因素层面对人为失误概率进行调控,可使户外端子箱操作人因可靠性得到提高,系统的风险等级随之降低。     

全氟辛烷磺酰基化合物水生生态风险和人体健康风险评价

全氟辛烷磺酰基化合物（Perfluorooctanesulfonate,PFOS ）广泛用于工农业生产,PFOS可通过不同的迁移路径迁移到大气、水和土壤等环境介质中。研究表明,PFOS是一种新的持久性有机物污染物,具有毒性,可通过食物链富集。2006年PFOS被欧盟议会和部长理事会列为限制销售和使用物质。本文引用中国沿海、亚洲海域和美国部分水域的PFOS暴露浓度数据,采用商值法对PFOS的水生生态环境风险进行了评价,建立了5 种因素水平的数学模型,并应用此数学模型对PFOS的人体健康风险进行了评价。结果表明我国部分地区和亚洲沿海PFOS的水生生态风险低于美国水域,亚洲沿海、我国部分地区以及美国部分城市水体中PFOS个人风险大小依次是我国部分地区<亚洲沿海<美国部分城市。     

Mixed uncertainty analysis of polycyclic aromatic hydrocarbon inhalation and risk assessment in ambient air of Beijing

This article presents the application of an integrated method that estimates the dispersion of polycyclic aromatic hydrocarbons (PAHs) in air, and assesses the human health risk associated with PAHs inhalation. An uncertainty analysis method consisting of three components were applied in this study, where the three components include a bootstrapping method for analyzing the whole process associated uncertainty, an inhalation rate (IR) representation for evaluating the total PAH inhalation risk for human health, and a normally distributed absorption fraction (AF) ranging from 0% to 100% to represent the absorption capability of PAHs in human body. Using this method, an integrated process was employed to assess the health risk of the residents in Beijing, China, from inhaling PAHs in the air. The results indicate that the ambient air PAHs in Beijing is an important contributor to human health impairment, although over 68% of residents seem to be safe from daily PAH carcinogenic inhalation. In general, the accumulated daily inhalation amount is relatively higher for male and children at 10 years old of age than for female and children at 6 years old. In 1997, about 1.73% cancer sufferers in Beijing were more or less related to ambient air PAHs inhalation. At 95% confidence interval, approximately 272–309 individual cancer incidences can be attributed to PAHs pollution in the air. The probability of greater than 500 cancer occurrence is 15.3%. While the inhalation of ambient air PAHs was shown to be an important factor responsible for higher cancer occurrence in Beijing, while the contribution might not be the most significant one.