Long-term population dynamics of ixodid ticks and development of tick-borne encephalitis foci under conditions of the middle taiga subzone

Long-term (1995–2003) population dynamics of ixodid ticks and their main hosts (small mammals) and conditions providing for the formation of tick-borne encephalitis (TBE) foci were studies in the middle taiga subzone (Karelia). The results show that the bank vole (Clethrionomys glareolus Schr.) is the main host for the larvae and nymphs of Ixodes persulcatus Schulze, 1930 and for the larvae, nymphs, and adult individuals of I. trianguliceps Birula, 1895. The proportion of ticks feeding on this species (relative to their total number) reaches 63.3% (64.0% of I. persulcatus and 61.1% of I. trianguliceps). Activity of a TBE focus is determined primarily by the abundance of bank voles of older age groups.     

燃烧后CO2气体捕集技术研究

从燃煤电厂排出的烟气分离技术,分为即燃烧前处理、富氧燃烧以及燃烧后处理三类,阐述燃烧后的处理方法.这种方法有五大技术发展方向,包括吸收、吸附、膜分离、霜冻分离和生物捕捉.对这五个方向的技术做一些阐述,并列举这几个方向下正在开展的研究实例,对二氧化碳捕集技术做一个较全面的介绍.     

不同构型人工湿地基质中土著菌的耐药性及整合子丰度调查

采用Kirby-Bauer纸片琼脂扩散法分析了夏、冬季节9个不同构型人工湿地中的葡萄球菌(Staphylococcus)、假单胞菌(Pseudomonas)两种土著菌对7种常用抗生素的耐药性,并通过荧光定量PCR检测人工湿地基质中Ⅰ型整合子(int1)的丰度.结果表明,共分离出的522株葡萄球菌和543株假单胞菌,约84%的菌株对所测试的抗生素具有耐药性,多重耐药率达到68%以上,MRI指数平均为0.22,与某些环境中人源或动物源细菌耐药水平相当,表明人工湿地基质土著菌具有较高水平的耐药性;两种土著菌对氨苄西林和复方新诺明的耐药率较高,四环素、庆大霉素和环丙沙星的耐药率均极低(3%),而对头孢他啶和氯霉素的耐药性呈现差别.湿地基质中int1基因的浓度为1.14×105~5.66×105copies·g-1,其相对丰度为0.54%~3.68%.季节和湿地工艺对细菌耐药和整合酶基因分布有较大影响.夏季2种细菌的抗生素耐药率、多重耐药指数和int1丰度均显著高于冬季;下行垂直流湿地中的抗生素耐药率、多重耐药指数(MRI)最高,而在水平潜流湿地中int1丰度最高.研究表明人工湿地基质的土著菌长期暴露在一定浓度抗生素和耐药肠道菌的生活污水环境下获得了耐药性,人工湿地中抗生素耐药菌和耐药基因的污染及环境风险不容忽视.     

旱地赤红壤钾素的Q/I特性

对12种旱地赤红壤与1种参比水稻土的钾素Q/I特性进行比较，结果表明，旱地由于土壤粘粒少，有机质质量分数低等因素的影响，其易释放钾库及供钾能力均小，钾位的缓冲性能很差，阳离子交换量较低；如不施钾肥或施肥不当，会造成作物减产或钾素损失。而由不同母质发育的旱地赤红壤，Q/I特性差别不大。     

Polymer coating of copper oxide nanoparticles increases nanoparticles uptake and toxicity in the green alga Chlamydomonas reinhardtii

Copper oxide nanoparticles (CuO NPs) are frequently used in a polymer-coated form, to be included in paints or fabrics for antimicrobial properties. Their application in antifouling paints may lead to the contamination of aquatic ecosystems. However, the toxicological risk of NPs in the environment is hard to evaluate due to a lack of knowledge on the mechanisms of NP interaction with biological systems. In this study, we investigated the effect of polymer coating on CuO NP toxicity in the green alga Chlamydomonas reinhardtii by comparing bare and polymer-coated CuO NPs prepared from the same CuO nanopowder. Both CuO NP suspensions were toxic to C. reinhardtii after 6 h treatment to concentrations of 0.005-0.04 g L⁻¹. Bare and polymer-coated CuO NPs induced a decrease of Photosystem II activity and the formation of reactive oxygen species. Polymer-coated CuO NP was found to be more toxic than the uncoated CuO NP. The higher toxicity of CS-CuO NP was mainly associated with the increased capacity of polymer-coated CuO NP to penetrate the cell compared to bare CuO NPs. These results indicates that the high toxicity of polymer-coated CuO NPs in algal cells results of intracellular interactions between NPs and the cellular system.     

Synthesis,structural characterization and antimicrobial activity of nickel(II) tetrathiocyanato dicuperate(I) complexes with some acyl hydrazones

Heterobimetallic complexes of the type Ni[Cu(SCN)₂]₂ · L (where L = acetophenone benzoylhydrazone, acetophenone isonicotinoyl hydrazone, acetophenone salicyloylhydrazone (ash), acetophenone anthraniloylhydrazone, p-hydroxy acetophenone benzoylhydrazone, p-hydroxy acetophenone isonicotinoyl hydrazone p-hydroxy acetophenone salicyloylhydrazone (phash), p-hydroxy acetophenone anthraniloyl hydrazone), were synthesized and characterized. The complexes are polymeric, insoluble in common organic solvents and are nonelectrolytes. Magnetic moments and electronic spectral studies suggest a spin-free octahedral geometry for the complexes. IR spectra show the bidentate nature of all the ligands bonding through >C=O and >C=N–groups. The SCN group acts as a bridge between two metal centers. X-ray powder diffraction parameters for Ni[Cu(SCN)₂]₂ · ash and Ni[Cu(SCN)₂]₂ · phash correspond to orthorhombic and tetrahedral crystal lattices, respectively, for these complexes. The complexes show a significant antifungal activity against Rizoctonia, Stemphylium and Aspergillus sp. and antibacterial activity against Clostridium and Pseudomonas sp. The metal complexes are more active than the ligands.     

Thallium(I) and thallium(III) induce apoptosis in isolated rat hepatocytes by alterations in mitochondrial function and generation of ROS

Environmental metal toxins, generated through diverse anthropogenic activities, constitute one of the major contaminants that have led to global dispersion of these toxic metals in the ecosystem. Thallium is one of these widely dispersed metals that produce severe adverse effects on human and biological systems. The influence of thallium(I) and thallium(III) on the early events that trigger apoptosis signaling were examined in freshly isolated rat hepatocytes. In addition, the role of oxidative stress, and mitochondria in the induction of apoptosis were also investigated. Incubation of thallium(I) and thallium(III) with isolated rat hepatocytes generated reactive oxygen species (ROS), collapse of mitochondrial membrane potential, activation of caspases cascade, and appearance of apoptosis phenotype. Mitochondrial permeability transition (MPT) pore sealing agents (cyclosporine A and carnitine) and ATP generators (L-glutamine, fructose, and xylitol) inhibited the activation of caspase-3 and apoptosis, indicating that both the cations activated apoptosis signaling via mitochondrial pathway. Pretreatment of hepatocytes with antioxidants (α-tocopherol or deferoxamine) also blocked caspase-3 activation induced by these cations, suggesting that oxidative stress may be directly involved in a mitochondrial MPT pore opening and activation of caspases cascade. These findings contribute to a better understanding of the mechanisms that mediate thallium-induced apoptosis in isolated rat hepatocytes.     

用改进的TRAP法测定树木端粒酶活性

TRAP法是一种常用的测定端粒酶活性的方法,但并不太适合测定木本植物的端粒酶活性.因此以油松针叶为实验材料,对TRAP法进行改进.参照前人的研究通过对比实验证明,在端粒酶提取过程中将PEG8000加入上清液,可获得高效的端粒酶.在此基础上,对PCR先导引选择TS、模板浓度选择100 ng,最终获得油松针叶高质量的端粒酶PCR产物.应用SYBR Green I替代银染液对电泳凝胶进行染色,获得条带清晰、重复性好的电泳结果.通过对油松针叶、银杏叶片、胡杨愈伤组织、沙冬青悬浮细胞等4种木本植物实验材料进行测定,证明该改进的技术体系可能是适合于木本植物端粒酶活性测定的稳定的、灵敏度高的可行方法.图5表1参17     

冬季APEC峰会前后室内外VOCs相关性分析

为研究冬季VOCs类物质的室内外相关性,于2014年11月5日~12月11日对一间无人为活动的房间的空气进行了室内外同步采样,定量分析了98种VOCs物质,并将其分为烷烃、烯烃、芳香烃、卤代烃和含氧烃五类,分别讨论了VOCs的浓度水平、I/O、室内外相关系数和分类间的相关系数,并利用质量平衡模型初步估计了室外源对室内VOCs的贡献情况.研究表明,五类VOCs的室内浓度均大于室外浓度,且烷烃>含氧烃>卤代烃>烯烃;五类VOCs均同时存在室内源和室外源;对于VOCs的室内外相关性,烯烃和含氧烃分别为相关性最差和最好的组分,同时,r(卤代烃)>r(烷烃)>r(芳香烃);对于物质间的相关性,烷烃-烯烃的相关性在室内外均最高(rin=0.805,rout=0.888,P￡0.01),卤代烃-含氧烃之间的相关性最差(rin=0.491,P￡0.05;rout=0.529,P￡0.01);室外源对室内浓度的贡献率与VOCs的种类相关,贡献率均值最高的是卤代烃类(56.57%),之后依次是烷烃(46.64%)、烯烃(40.10%)、含氧烃(33.98%)和芳香烃(20.67%).此外,APEC峰会后VOCs的浓度水平、I/O、室内外相关性以及物质间的相关性均高于峰会前的对应值.     

Environmental policy and human capital inequality: A matter of life and death

This paper analyzes the economic implications of an environmental policy when we account for the life expectancy of heterogeneous agents. In a framework in which everyone suffers from pollution but health status also depends on individual human capital, we find that the economy may be stuck in a trap in which inequality rises steadily, especially when the initial pollution intensity of production is too high. We emphasize that such inequality is in the long run costly for the economy in terms of health and growth. Therefore, we study whether a tax on pollution associated with an investment in pollution abatement can be used to address this situation. We show that a stricter environmental policy may allow the economy to escape from the inequality trap while enhancing the long-term growth rate when the initial inequality in human capital is not too large.