The ruthenium(II)–arene compound RAPTA-C induces apoptosis in EAC cells through mitochondrial and p53–JNK pathways

An investigation of the molecular mechanism of the anticancer activity demonstrated by the ruthenium(II)–arene compound [Ru(η⁶-p-cymene)Cl₂(pta)] (pta is 1,3,5-triaza-7-phosphaadamantane), termed “RAPTA-C”, in Ehrlich ascites carcinoma (EAC) bearing mice is described. RAPTA-C exhibits effective cell growth inhibition by triggering G₂/M phase arrest and apoptosis in cancer cells. Cell cycle arrest is associated with increased levels of p21 and reduced amounts of cyclin E. RAPTA-C treatment also enhances the levels of p53, and its treatment triggers the mitochondrial apoptotic pathway, as shown by the change in Bax to Bcl-2 ratios, resulting in cytochrome c release and caspase-9 activation. c-Jun NH₂-terminal kinase (JNK) is a critical mediator in RAPTA-C-induced cell growth inhibition. Activation of JNK by RAPTA-C increases significantly during apoptosis. Overall, these results suggest a critical role for JNK and p53 in RAPTA-C-induced G₂/M arrest and apoptosis of EAC-bearing mice. Consequently, RAPTA-C treatment results in a significant inhibition in the progression of cancer in an animal model, which emulates the human disease, and does so with remarkably low general toxicity; hence, RAPTA-C has potential for clinical application.     

不同层面上微生物多样性研究方法

在讨论不同层面上微生物多样性研究的特征和对比各主要研究方法的基础上,探讨了在不同层面上研究微生物多样性时对方法的选择性应用,分析了微生物多样性研究技术体系的发展趋势。     

Habitat monitoring in Europe: a description of current practices

Monitoring of biodiversity at the level of habitats is becoming increasingly common. Here we describe current practices in habitat monitoring based on 150 schemes in Europe. Most schemes were initiated after 1990 in response to EU nature directives or habitat management/restoration actions, with funding mostly from European or national sources. Schemes usually monitor both the spatial distribution and the quality of the habitats, and they frequently collect data on environmental parameters and potential causes of changes. Many schemes are local or regional rather than national or international in scope, and sampling effort varies greatly across spatial and temporal scales. Experimental design is used in half of the schemes, however, data are rarely analysed by advanced statistics. Most schemes require two months or less per year in manpower and are typically run by professionals rather than by volunteers. Estimated salaries plus equipment costs average 650,000 Euro per year per scheme, and add up to 80 million Euros annually. Costs are particularly high for schemes based on European or international law and for schemes funded by European or national sources. Costs are also high in schemes in which sampling sites are selected subjectively rather than based on sampling theory, and in schemes that do not use field mapping or remote sensing to document spatial variation in habitats. Our survey demonstrates promising developments in European habitat monitoring but also underlines the need for better spatial coverage, documentation of spatial variaton, improved sampling design and advanced data analysis. Such improvements are essential if we are to judge progress towards the 2010 biodiversity targets.     

生态系统服务视角下的景观美学研究进展

美学是生态系统服务的重要研究内容之一,从美和美学的本质入手去探讨景观美学的概念和范围,明确了景观美学的研究内容,确定景观审美和审美主体与客体之间对立统一的辩证关系,总结景观美学的传统研究方法,如问卷调查法、美景度法、语义差异法、层次分析法等.但是人对景观的主观感知一直都采用的是模糊评价法,用于评估和监测景观美学的标准化...     

Managing intentions: the end-of-life administration of analgesics and sedatives, and the possibility of slow euthanasia

There has been much debate regarding the 'double-effect' of sedatives and analgesics administered at the end-of-life, and the possibility that health professionals using these drugs are performing 'slow euthanasia.' On the one hand analgesics and sedatives can do much to relieve suffering in the terminally ill. On the other hand, they can hasten death. According to a standard view, the administration of analgesics and sedatives amounts to euthanasia when the drugs are given with an intention to hasten death. In this paper we report a small qualitative study based on interviews with 8 Australian general physicians regarding their understanding of intention in the context of questions about voluntary euthanasia, assisted suicide and particularly the use of analgesic and sedative infusions (including the possibility of voluntary or non-voluntary 'slow euthanasia'). We found a striking ambiguity and uncertainty regarding intentions amongst doctors interviewed. Some were explicit in describing a 'grey' area between palliation and euthanasia, or a continuum between the two. Not one of the respondents was consistent in distinguishing between a foreseen death and an intended death. A major theme was that 'slow euthanasia' may be more psychologically acceptable to doctors than active voluntary euthanasia by bolus injection, partly because the former would usually only result in a small loss of 'time' for patients already very close to death, but also because of the desirable ambiguities surrounding causation and intention when an infusion of analgesics and sedatives is used. The empirical and philosophical implications of these findings are discussed.     

小麦遗传转化研究进展

小麦作为最重要的3大禾谷作物之一,其离体培养具有很强的惰性,再生频率与水稻、玉米相比要低一些,目前大多通过对基因型和外植体的选择来达到植株的高频再生分化,因此其遗传转化就远远滞后于水稻和玉米,更不用说与其它双子叶植物相比了.重点综述了小麦转基因技术和外源基因在小麦中的遗传转化研究现状,其内容包括几种主要的小麦转基因方法和以基因枪法为主的各种转化技术对品质基因、抗除草剂基因和抗病等基因在小麦中的遗传转化研究进展,并对存在的一些问题进行了简要的论述.     

中国茴香属的比较研究及分类处理意见

从细胞学、孢粉学、形态学角度,并辅以解剖学和胚胎学方法,对茴香属Foeniculum Miller植物球茎茴香F.vulgare subsp.copillaceum var.azoricum（Miller）Thellung与茴香F.vulgare Miller进行了比较研究。结果表明,孢粉学特征差异表现在花粉粒类型、球状、大小、萌发孔、纹饰等方面;细胞学特征差异表现在核型不对称系数、染色体组成、最长染色体与最短染色体之比值等方面;形态学特征差异包括基部茎、基部叶叶鞘及果实主棱的圆钝等方面;解剖学上发现数量性状差异;胚胎学方面则表现在珠被上。就上述对应特征而言,茴香均表现出比球茎茴香更为进化的特性。据此,支持Miller（1768）将球茎茴香均作为等级的处理意见,而不支持将球茎茴香视为茴香变种,以及为茴香异名的观点,并恢复其名称为Foeniculum azoricum Miller。     

中国赤潮的发生趋势和研究进展

通过对中国沿海赤潮发生历史的回顾以及主要赤潮事件的分析,阐明了中国沿海赤潮发生所呈现的趋势,即频率增加,规模扩大,新的赤潮藻种不断出现,有毒赤潮种比例上升,以及有害赤潮危害程度日益增加,且初步分析了赤潮频发的内因和外因,综述了我国科学家在赤潮生消过程监测,赤潮灌的培养生物学和分类学,赤潮藻类的营养动力学及生理生态学特性,赤潮藻类的生活史,赤潮藻类毒素,赤潮的模型和赤潮防治及国际合作等方面工作的进展,指出了研究还存在的不足之处,并对未来赤潮研究和管理提出了建议。     

浅谈昆虫分类学的研究方向

本文阐述了昆虫分类学的 3个研究方向及其形成过程、各自的研究重心和意义、各自解决的关键问题和工作内容以及 3个研究方向的相互关系。     

Nitrogen Fluxes and Retention in Urban Watershed Ecosystems

Although the watershed approach has long been used to study whole-ecosystem function, it has seldom been applied to study human-dominated systems, especially those dominated by urban and suburban land uses. Here we present 3 years of data on nitrogen (N) losses from one completely forested, one agricultural, and six urban/suburban watersheds, and input–output N budgets for suburban, forested, and agricultural watersheds. The work is a product of the Baltimore Ecosystem Study, a long-term study of urban and suburban ecosystems, and a component of the US National Science Foundations long-term ecological research (LTER) network. As expected, urban and suburban watersheds had much higher N losses than did the completely forested watershed, with N yields ranging from 2.9 to 7.9 kg N ha^–1 y^–1 in the urban and suburban watersheds compared with less than 1 kg N ha^–1 y^–1 in the completely forested watershed. Yields from urban and suburban watersheds were lower than those from an agricultural watershed (13–19.8 kg N ha^–1 y^–1). Retention of N in the suburban watershed was surprisingly high, 75% of inputs, which were dominated by home lawn fertilizer (14.4 kg N ha^–1 y^–1) and atmospheric deposition (11.2 kg N ha^–1 y^–1). Detailed analysis of mechanisms of N retention, which must occur in the significant amounts of pervious surface present in urban and suburban watersheds, and which include storage in soils and vegetation and gaseous loss, is clearly warranted.