石墨烯与抑癌基因p53 DNA片段相互作用的分子模拟与光谱学验证

石墨烯(graphene,G)及其衍生物由于具有独特的理化性质,被广泛应用于能源、生物医学等领域,但尚缺乏其对生物体和环境潜在危害的研究。采用分子动力学模拟并结合光谱学方法(紫外可见吸收光谱、紫外变温实验及荧光光谱),分析了石墨烯与抑癌基因p53启动子区DNA片段(p53-DNA)间的相互作用,并探讨了相关作用机制。石墨烯的部分芳香环与p53-DNA碱基的芳香环之间存在π-π堆积作用,两者可以通过嵌插作用进行结合,同时还通过沟槽作用进一步结合。光谱实验进一步证实,在石墨烯作用下,p53-DNA的熔点(Tm)值升高,EB-DNA体系发生静态荧光淬灭,说明石墨烯能与p53-DNA结合;同时,p53-DNA与石墨烯结合后在260 nm处的吸光度升高,说明石墨烯对p53-DNA的双螺旋结构具有一定的破坏作用。上述研究结果从分子水平上分析了石墨烯与p53-DNA间的相互作用机制,有助于进一步阐明石墨烯的毒性作用机理。     

海洋微生物多样性的研究进展

介绍了海洋微生物多样性研究的意义,综述了国内外开展海洋微生物多样性的主要研究方法和原理。重点介绍了分子生物学技术在研究中的应用,对序列分析和指纹图谱、分子标记、分子探针等方法进行了详细的阐述。     

大气化学非均相反应摄取系数的测定

摄取系数是表征大气非均相反应的重要物理化学参数,也是大气颗粒物表面摄取气体能力的重要量化指标.本文综述了摄取系数的主要概念、主要测定方法和影响因素,以NaCl与NO2非均相反应为例,讨论了用漫反射傅立叶转换红外原位反应器扩散实验方式测定反应摄取系数的方法和误差,分析了气体扩散深度与红外穿透厚度对测定结果的影响,并测定了初始反应摄取系数.     

环境中微/纳米塑料的污染现状、分析方法、毒性评价及健康效应研究进展

微塑料是粒径小于5 mm的塑料颗粒,纳米塑料是粒径小于1 μm的塑料颗粒.微/纳米塑料广泛存在于各种环境介质中,由于其粒径小、比表面积大,很容易被直接吸入、经口食入或皮肤浸入至体内,造成毒害作用,危害健康.本文主要总结了环境中微/纳米塑料在水、大气、土壤和食品中的污染现状,阐述了其对生物体可能产生的毒性效应,探讨了其对...     

Monitoring Changes in Freshwater Macroinvertebrate Communities Along a Salinity Gradient Using Artificial Substrates

Scientists strive to develop efficient sampling protocols, reducing both the number of samples and processing time required, which can be adapted for use in a broad range of ecosystems. We investigated the accuracy and usefulness of artificial substrates in monitoring the impact of rising salinity on freshwater macroinvertebrate communities. We sampled seven sites along a salinity gradient (from 0.2gL^-1 to 2.6gL^-1) over a 19-km stretch of the Meurthe River, in northeastern France. All other parameters remained stable in this section of the river. Artificial substrate samples, each consisting of six liters of pebbles, were removed from the river at one-month intervals and examined. Results obtained indicated the same qualitative impairments as those found in samples collected using a Surber net. The use of artificial substrates was found to be a viable alternative method for assessing biological changes in river quality due to increasing salinity disturbance when Surber sampling cannot be performed.     

Evaluation of A Sampling Strategy for Estimation of Long-term Pm2.5 Exposure for Epidemiological Studies

As part of the European Community Respiratory Health Survey (ECRHS) PM_2.5 (particles collected with an upper 50% cut point of 2.5 μm aerodynamic diameter) was measured using an EPA-WINS (Environmetal Protection Agency Well Impactor Ninety-six) sampler. The monitoring schedule was restricted to 7 days per month for one year. Simultaneously, during this one year study period a collocated Harvard Impactor (HI) was run on a daily basis in Erfurt, Germany. Here we validated the reliability of annual, seasonal and monthly means estimated using the ECRHS scheme (measurements taken less than 25% of the whole study period) with the ‘true’ long-term averages, which were estimated using all available daily means.The daily PM_2.5 means, obtained by both instruments operated in parallel, were only slightly different (the mean difference between EPA-WINS and HI was 1.8 μg m⁻³ and 2.8 μg m⁻³ for the winter means). The values obtained by the two instruments were highly correlated (r = 0.95).In view of that negligible difference, no additional bias was seen with respect to the annual and the winter means estimated by the two different sampling strategies (the difference was 1.7 μg m⁻³ and 2.7 μg m⁻³, respectively). Monthly means, however, can only be considered to be a crude estimate that may substantially under- or overestimate the true monthly mean value.     

电动力学及其联用技术降解污染土壤中持久性有机污染物的研究进展

采用电动力学及其联用技术降解污染土壤中的持久性有机污染物是近10a发展起来的新型原位修复技术,本文综述了电动力学及其联用技术降解污染土壤中持久性有机污染物的5种主要方法:①电动力学技术;②电动力学结合Fenton技术;③电动力学结合生物技术;④电动力学结合表面活性剂/助溶剂技术;⑤电动力学结合超声技术.介绍了各种方法的基本原理、特点、应用范围和研究进展,提出了今后的研究方向.     

Performance Evaluation of the SLEUTH Model in the Shenyang Metropolitan Area of Northeastern China

Performance evaluation is crucial for the development and improvement of an urban cellular automata model, such as SLEUTH. In this paper, we employed multiple methods for map comparison and model validation to evaluate the simulation performance of the SLEUTH urban growth model in the Shenyang metropolitan area of China. These multiple methods included the relative operating characteristic (ROC) curve statistic, multiple-resolutions error budget, and landscape metrics. They were used to quantitatively examine model performance in terms of the amount and spatial location of urban development, urban spatial pattern and prediction ability. The assessment results showed that SLEUTH performed well in the way of the quantitative simulation of urban growth for this case study. Similar to other urban growth models, however, the simulation accuracy for spatial location of new development at the pixel scale and urban spatial pattern still needs to be improved greatly. These inaccuracies might be attributed to the structure and nature of SLEUTH, local urban development characteristics, and the temporal and spatial scale of its application. Finally, many valuable suggestions had been put forward to improve simulation performance of SLEUTH model for spatial location of urban development in the Shenyang metropolitan area.     

水环境中多环芳烃的污染现状及研究进展

概述了多环芳烃(PAHs)的属性和主要来源,介绍了其在不同环境介质中的分析方法、污染状况、迁移转化及风险评估现状,提出了进一步加强复杂环境基质中PAHs分析方法、不同环境介质中PAHs迁移转化特征,以及PAHs环境生态风险和人体健康风险等方面研究的建议。     

浅析定电位电解法测试SO2应注意的问题

用定电位电解法测定SO2时,会出现多种影响测试结果的各种因素。本文对此进行了讨论,结果表明,采取有效措施可降低干扰,极大的提高了污染源监测和在线比对监测的可靠性和准确性。