铁掺杂纳米氧化锌室温脱硫剂的结构及效能研究

采用均匀沉淀法制备了铁掺杂纳米氧化锌脱硫剂,利用XRD和BET手段对脱硫剂进行了表征,优化了铁的掺杂量,并探讨了焙烧温度、脱硫温度和氧含量等因素对脱除H2S性能的影响。结果表明,铁的掺杂使脱硫剂的比表面积和孔容增大,当Fe∶Zn的摩尔比为5∶100(FZ5.0)时其活性最好。FZ5.0脱硫剂适用于室温脱硫,当样品的焙烧温度为270℃,氧含量为10%,穿透时间达到370 m in时,脱硫性能最佳。     

聚合氯化铝组合芽孢杆菌发酵液法对链状裸甲藻孢囊种源萌发调控研究

对比不同浓度梯度的聚合氯化铝(poly aluminium chloride,以下简称"PAC")和不同发酵时间、不同投加量的Ba3芽孢杆菌(Bacillus)发酵液及两者组合法对链状裸甲藻(Gymnodinium catenatum)的除藻效果,用最佳投加量进行了沉积物种源萌发调控实验,探究了PAC组合菌发酵液方法对...     

中华鳖胚胎期氯吡硫磷暴露对孵出幼体生理表现的影响

氯吡硫磷是一种广泛用于控制农作物上有害昆虫的有机磷杀虫剂,对水生生物可能具有较高毒性.用不同质量浓度(0、0.03、0.3、3.0 mg/L)的氯吡硫磷溶液处理孵化中的中华鳖受精卵,测定胚胎存活、孵出幼体大小、游泳表现、早期生长及肝脏生理指标(甘油三酯和丙二醛含量、超氧化物歧化酶和过氧化氢酶活性)来评估胚胎期氯吡硫磷暴露对中华鳖胚胎发育及幼体生理表现的潜在影响.在0.03～3.0 mg/L的质量浓度范围内,氯吡硫磷暴露并不显著改变包括胚胎存活、孵化期、幼体大小、运动、生长速度和生理表现在内的所有测量指标.该结果表明低浓度的氯吡硫磷暴露可能对水生龟鳖类动物胚胎发育和幼体表型的影响不大.     

中国股市的拓扑结构及其复杂性质研究

在计算中国股市各股票之间的关联函数的基础上,利用最小生成树方法构建了股市的拓扑结构,从而验证了股市板块内部的共振效应,并发现股市的拓扑结构的连通性分布满足幂律关系。为此,本文从自组织临界性的角度研究了股市的复杂性质,其所得到的股市整体结构的分形性,将成为股市复杂系统鲁棒性研究的基础。     

基于WebGIS 的汉江水环境管理信息系统

依据互联网地理信息系统（WebGIS）的实现技术及特点,分析了ArcIMS的体系结构及其运行机制,通过基于ArcIMS9平台并结合JS,JSP等技术,提出一种新的具有多层结构的WebGIS解决方案,并结合具体实例阐述了其在水环境管理信息系统的实现．结合水环境管理信息系统的需求,给出了基于WebGIS的水环境管理信息系统的功能体系结构．采用Apache＋Tomcat作为网络服务器、ArcIMS作为地图服务器完成了系统功能设计,实现了网上数字地图的处理、传送,以及基于地图的水环境信息查询、评估、统计、分析,和排放污染总量与污染源的控制决策．     

Yersinia pestis genome sequencing identifies patterns of global phylogenetic diversity

Plague is a pandemic human invasive disease caused by the bacterial agent Yersinia pestis. We here report a comparison of 17 whole genomes of Y. pestis isolates from global sources. We also screened a global collection of 286 Y. pestis isolates for 933 SNPs using Sequenom MassArray SNP typing. We conducted phylogenetic analyses on this sequence variation dataset, assigned isolates to populations based on maximum parsimony and, from these results, made inferences regarding historical transmission routes. Our phylogenetic analysis suggests that Y. pestis evolved in or near China and spread through multiple radiations to Europe, South America, Africa and Southeast Asia, leading to country-specific lineages that can be traced by lineage-specific SNPs. All 626 current isolates from the United States reflect one radiation, and 82 isolates from Madagascar represent a second radiation. Subsequent local microevolution of Y. pestis is marked by sequential, geographically specific SNPs.     

Common variants at TRAF3IP2 are associated with susceptibility to psoriatic arthritis and psoriasis

Psoriatic arthritis (PsA) is an inflammatory joint disease that is distinct from other chronic arthritides and which is frequently accompanied by psoriasis vulgaris (PsV) and seronegativity for rheumatoid factor. We conducted a genome-wide association study in 609 German individuals with PsA (cases) and 990 controls with replication in 6 European cohorts including a total of 5,488 individuals. We replicated PsA associations at HLA-C and IL12B and identified a new association at TRAF3IP2 (rs13190932, P = 8.56 × 10?1?). TRAF3IP2 was also associated with PsV in a German cohort including 2,040 individuals (rs13190932, P = 1.95 × 10?3). Sequencing of the exons of TRAF3IP2 identified a coding variant (p.Asp10Asn, rs33980500) as the most significantly associated SNP (P = 1.13 × 10?2?, odds ratio = 1.95). Functional assays showed reduced binding of this TRAF3IP2 variant to TRAF6, suggesting altered modulation of immunoregulatory signals through altered TRAF interactions as a new and shared pathway for PsA and PsV.     

Rad51 and DNA-PKcs are involved in the generation of specific telomere aberrations induced by the quadruplex ligand 360A that impair mitotic cell progression and lead to cell death

Functional telomeres are protected from non-homologous end-joining (NHEJ) and homologous recombination (HR) DNA repair pathways. Replication is a critical period for telomeres because of the requirement for reconstitution of functional protected telomere conformations, a process that involves DNA repair proteins. Using knockdown of DNA-PKcs and Rad51 expression in three different cell lines, we demonstrate the respective involvement of NHEJ and HR in the formation of telomere aberrations induced by the G-quadruplex ligand 360A during or after replication. HR contributed to specific chromatid-type aberrations (telomere losses and doublets) affecting the lagging strand telomeres, whereas DNA-PKcs-dependent NHEJ was responsible for sister telomere fusions as a direct consequence of G-quadruplex formation and/or stabilization induced by 360A on parental telomere G strands. NHEJ and HR activation at telomeres altered mitotic progression in treated cells. In particular, NHEJ-mediated sister telomere fusions were associated with altered metaphase-anaphase transition and anaphase bridges and resulted in cell death during mitosis or early G1. Collectively, these data elucidate specific molecular and cellular mechanisms triggered by telomere targeting by the G-quadruplex ligand 360A, leading to cancer cell death.     

Propagation of histone marks and epigenetic memory during normal and interrupted DNA replication

Although all nucleated cells within a multicellular organism contain a complete copy of the genome, cell identity relies on the expression of a specific subset of genes. Therefore, when cells divide they must not only copy their genome to their daughters, but also ensure that the pattern of gene expression present before division is restored. While the carrier of this epigenetic memory has been a topic of much research and debate, post-translational modifications of histone proteins have emerged in the vanguard of candidates. In this paper we examine the mechanisms by which histone post-translational modifications are propagated through DNA replication and cell division, and we critically examine the evidence that they can also act as vectors of epigenetic memory. Finally, we consider ways in which epigenetic memory might be disrupted by interfering with the mechanisms of DNA replication.