(Ni-Sn-M_xO_y)/Pb改性复合电极电解合成L-半胱氨酸的反应

在（Ｎｉ－Ｓｎ）／Ｐｂ合金修饰电极中添加某些金属氧化物进行改性,用于电解合成Ｌ－半胱氨酸反应。结果证明,添加ＷＯ３后电极反应活性大大加强,反应同期转化率有较大提高,选择性也有所提高,添加稀土金属氧化物能有效降低反应阴极过电位,使反应选择性有所提高,但是电极稳定性还有待改善。     

Precise Sequential DNA Ligation on A Solid Substrate: Solid-Based Rapid Sequential Ligation of Multiple DNA Molecules

Ligation, the joining of DNA fragments, is a fundamental procedure in molecular cloning and is indispensable to the production of genetically modified organisms that can be used for basic research, the applied biosciences, or both. Given that many genes cooperate in various pathways, incorporating multiple gene cassettes in tandem in a transgenic DNA construct for the purpose of genetic modification is often necessary when generating organisms that produce multiple foreign gene products. Here, we describe a novel method, designated PRESSO (precise sequential DNA ligation on a solid substrate), for the tandem ligation of multiple DNA fragments. We amplified donor DNA fragments with non-palindromic ends, and ligated the fragment to acceptor DNA fragments on solid beads. After the final donor DNA fragments, which included vector sequences, were joined to the construct that contained the array of fragments, the ligation product (the construct) was thereby released from the beads via digestion with a rare-cut meganuclease; the freed linear construct was circularized via an intra-molecular ligation. PRESSO allowed us to rapidly and efficiently join multiple genes in an optimized order and orientation. This method can overcome many technical challenges in functional genomics during the post-sequencing generation.     

Quantifying the evidence for ecological synergies

There is increasing concern that multiple drivers of ecological change will interact synergistically to accelerate biodiversity loss. However, the prevalence and magnitude of these interactions remain one of the largest uncertainties in projections of future ecological change. We address this uncertainty by performing a meta-analysis of 112 published factorial experiments that evaluated the impacts of multiple stressors on animal mortality in freshwater, marine and terrestrial communities. We found that, on average, mortalities from the combined action of two stressors were not synergistic and this result was consistent across studies investigating different stressors, study organisms and life-history stages. Furthermore, only one-third of relevant experiments displayed truly synergistic effects, which does not support the prevailing ecological paradigm that synergies are rampant. However, in more than three-quarters of relevant experiments, the outcome of multiple stressor interactions was non-additive (i.e. synergies or antagonisms), suggesting that ecological surprises may be more common than simple additive effects.     

铁皮石斛腋芽的快速繁殖

目的利用组织培养技术建立铁皮石斛的高效快繁体系,克隆繁殖种苗,为野生居群的恢复提供材料。方法以铁皮石斛腋芽为外植体,研究不同浓度和配比的基本培养基、激素以及天然提取物对腋芽萌发生长,丛生芽的诱导增殖以及壮苗生根的影响,比较不同培养阶段的增殖倍数,筛选各时期的最适培养基。并对试管苗的形态学特征进行了调查。结果1/2MS+NAA 0.2 mg/L+BA 1 mg/L适合腋芽的成活生长。BA与香蕉汁组合有利于丛生芽的诱导增殖,其最适比例为1/2MS+NAA 0.5 mg/L+BA 2.0 mg/L+香蕉汁100 g/L,增殖倍数最大可达14.0,平均增殖倍数为6.4。培养基中添加100 g/L香蕉汁或200 g/L马铃薯汁均有利于壮苗生根。结论铁皮石斛通过腋芽形成丛生芽途径建立高效的快繁技术体系获得优质种苗是可行的。     

昆虫多次交配的策略和利益

简要回顾昆虫交配系统的研究历史,并简述Bateman的性选择原理,讨论雌雄昆虫在交配过程中的角色和性选择压力的相对关系。一般而言,由于雌雄两性在交配过程中的角色和对后代投入的不同,往往是雄虫试图与尽可能多的雌虫交配,即雄虫使自己被尽可能多的雌虫接受,雌虫选择最好的雄虫进行交配,即雌虫选择交配对象。雄虫因而发展出各种类型的交配策略,以获取与更多雌虫的交配机会;而雌虫也通过交配选择权,选择对自己更有利的雄虫进行交配,雌虫在交配过程中除了可以获得基因利益,还可以获取物质利益。文章分别就昆虫的交配策略和利益展开叙述和讨论。     

多发性骨髓瘤细胞中一个表达上调基因的克隆与分析

根据GenBank收录的多发性骨髓瘤细胞株 (ARH 77)表达上调ESTAF4 2 5 30 0设计引物 ,运用RT PCR检测了 5例多发性骨髓瘤患者及 4例正常人骨髓细胞中该EST的表达水平 .Northern印迹杂交分析该EST在多种组织中的表达 .进一步利用该EST作探针 ,筛选ARH 77cDNA文库 ,获得全长cDNA克隆 ,对该序列进行了分析 .结果显示 ,该EST在多发性骨髓瘤患者骨髓细胞中亦有较高的表达 ,而在正常人骨髓细胞中低表达 .经测序证实 ,该cDNA全长为 4 5 2bp(GenBank收录号 :AF4 87338) .预测其编码一个 5 7个氨基酸的小分子量蛋白质 ,属于与DNA复制有关的解旋酶 引物酶基因家族的新成员 .该基因在多发性骨髓瘤细胞中表达上调 ,其表达水平的改变可能与多发性骨髓瘤的发生与发展有关     

Integrated analysis of multiple data sources reveals modular structure of biological networks

It has been a challenging task to integrate high-throughput data into investigations of the systematic and dynamic organization of biological networks. Here, we presented a simple hierarchical clustering algorithm that goes a long way to achieve this aim. Our method effectively reveals the modular structure of the yeast protein-protein interaction network and distinguishes protein complexes from functional modules by integrating high-throughput protein-protein interaction data with the added subcellular localization and expression profile data. Furthermore, we take advantage of the detected modules to provide a reliably functional context for the uncharacterized components within modules. On the other hand, the integration of various protein-protein association information makes our method robust to false-positives, especially for derived protein complexes. More importantly, this simple method can be extended naturally to other types of data fusion and provides a framework for the study of more comprehensive properties of the biological network and other forms of complex networks.     

多发性骨髓瘤恶性相关基因快速表达克隆法的建立

为从多发性骨髓瘤细胞中克隆与鉴定恶性相关基因并试图阐明其发病分子机制,建立了一种改进的快速表达克隆法,简单、快捷、直接从多发性骨髓瘤细胞株ARH-77 cDNA文库中克隆恶性相关基因。其特点是常用的表达克隆法与经典的DNA介导的NIH／3T3转染实验相结合,直接从cDNA表达文库中克隆恶性相关基因。首先建立高质量的cDNA表达文库,将cDNA表达文库分成几个基因池,转染NIH／3T3细胞;将转化活性最强的基因池再分成几个亚基因池,转染NIH／3T3细胞;将转化活性最强的亚基因池再分成次级亚基因池,直到获得有明显转化活性的单个cDNA克隆。该技术亦可用于从其他肿瘤细胞中克隆恶性相关基因。     

多约束代谢网络模型的研究进展

基于约束的基因组尺度代谢网络模型(genome-scale metabolic models,GEMs)分析已被广泛应用于代谢表型的预测.而实际细胞中代谢速率除计量学约束外,还受到酶资源可用性和反应热力学可行性等其他因素影响,在GEMs中整合酶资源约束或者热力学约束构建多约束代谢网络模型可以进一步缩小优化解空间,提升细...