兰州唐古特白刺根际微生物分离鉴定

【目的】从兰州唐古特白刺根际分离得到对植物有潜在促生效果的功能微生物，为研发相关菌种制剂的研究奠定基础。【方法】通过平板划线法从其根际分离纯化出6株细菌，并对菌株进行形态特征观察、革兰氏染色等一系列生理生化试验。用藜麦检测各菌株的促生功能，并对具有优良促生作用的1个菌株16S rRNA基因进行分子鉴定及基因草图绘制。【结果】根据生化鉴定结果，6株细菌分别属于不动杆菌属(Acinetobacter)、土壤杆菌属(Agrobacterium)、类芽孢杆菌属(Paenibacillus)、芽孢杆菌属(Bacillus)、鞘氨醇单胞菌属(Sphingomonas)和假单胞菌属(Pseudomonas)。其中，16S rRNA基因鉴定BC4属于肠杆菌属(Enterobacter)，具有较好的促生效果。【结论】BC4具有较好的促生效果，为兰州唐古特白刺菌种资源的开发和利用提供了一定的理论依据。     

D-β-Hydroxybutyrate Prevents MPP+-Induced Neurotoxicity in PC12 Cells

Numerous studies show that D-β-Hydroxybutyrate (DβHB) is neuroprotective. The present study was to explore the neuroprotective effects of DβHB against the cell death and apoptosis induced by 1-methyl-4-phenylpyridinium ion (MPP+) in PC12 cells. PC12 cells were pretreated with DβHB and followed by MPP+ exposure. The cell viability was determined by MTT assay. The morphological characteristics of apoptosis was observed by Acridine Orange (AO) staining and apoptotic rates were measured by flow cytometer. The product of lipid peroxidation, malondialdehyde (MDA), was measured using thiobarbituric acid method. The mitochondrial membrane potential (MMP), intracellular ROS and total glutathione were detected by microplate reader. In PC12 cells, pretreatment with DβHB significantly reduced MPP+-induced the decrease of cell viability. AO staining and flow cytometric analysis found DβHB inhibited MPP+-induced apoptosis. The measurement of MDA formation showed that DβHB alleviated lipid peroxidation induced by MPP+. The loss of MMP induced by MPP+ was preventive by DβHB. The changes of intracellular ROS and total glutathione induced by MPP+ were reversed by DβHB. DβHB protected PC12 cells against MPP+-induced death and apoptosis.     

Abundances and host relationships of chigger mites in Yunnan Province,China

This paper reports on ectoparasitic chigger mites found on small mammals in Yunnan Province, southwest China. Data were accumulated from 19 investigation sites (counties) between 2001 and 2009. A total of 10 222 small mammal hosts were captured and identified; these represented 62 species, 34 genera and 11 families in five orders. From the body surfaces of these 10 222 hosts, a total of 92 990 chigger mites were collected and identified microscopically. These represented 224 species, 22 genera and three subfamilies in the family Trombiculidae (Trombidiformes). Small mammals were commonly found to be infested by chigger mites and most host species harboured several species of mite. The species diversity of chigger mites in Yunnan was much higher than diversities reported previously in other provinces of China and in other countries. A single species of rodent, Eothenomys miletus (Rodentia: Cricetidae), carried 111 species of chigger mite, thus demonstrating the highest species diversity and heaviest mite infestation of all recorded hosts. This diversity is exceptional compared with that of other ectoparasites. Of the total 224 mite species, 21 species accounted for 82.2% of all mites counted. Two species acting as major vectors for scrub typhus (tsutsugamushi disease), Leptotrombidium scutellare and Leptotrombidium deliense, were identified as the dominant mite species in this sample. In addition to these two major vectors, 12 potential or suspected vector species were found. Most species of chigger mite had a wide range of hosts and low host specificity. For example, L. scutellare parasitized 30 species of host. The low host specificity of chigger mites may increase their probability of encountering humans, as well as their transmission of scrub typhus among different hosts. Hierarchical clustering analysis showed that similarities between different chigger mite communities on the 18 main species of small mammal host did not accord with the taxonomic affinity of the hosts. This suggests that the distribution of chigger mites may be strongly influenced by the environment in which hosts live.     

大型煤电基地开发生态累积效应及定量分析方法研究

大型煤电基地(CEBs)是我国煤基能源和材料集中开发区域和国家能源战略安全重要支撑，合理评价CEBs开发生态影响是CEBs可持续协调开发、科学管理中的难点问题。研究将CEBs开发视为系统工程，与自然生态系统(NES)相关联，深入研究大型煤电基地生态系统(CEBES)的驱动行为、内在结构及主要关系、生态影响途径、生态累积过程和生态累积效应及阈值分析方法。基于CEBs空间和功能定位提出CEBs的概念、内涵和特点，融合构建的CEBES涵盖到自然资源、能源开发行为(煤、电等)、其他人类活动(农、牧、城)和大气、水、土壤及生物域；研究表明CEBES的生态累积状态受三种行为驱动和影响(自然行为、能源开发行为和其他人类活动),通过融合、传导和辐射耦合作用，表现为生态要素损伤、系统结构变化和系统状态失衡三级状态，生态累积具有影响多态性、空间多尺度和过程渐变性特点；明确了生态累积过程、累积效应和阈值及其相互关系，引入反映生态影响累积程度的生态损伤系数，提出四类生态阈值(生态要素、内部结构、系统状态和行为调控);基于系统性和实用性筛选反映生态累积相对状态的60项指标，构建具有“三力”驱动、分区要素耦合和系...     

IGF-Ⅱ、IGF-lR、IGFBP-3在结直肠癌中的表达及诊断价值研究

目的:探讨结直肠癌中IGF-Ⅱ、IGF-l R以及IGFBP-3等的阳性表达及诊断价值。方法:收集我院45例结直肠癌、33例炎性息肉、40例腺瘤以及35例正常肠粘膜组织予以免疫组织化学SP法进行IGF-Ⅱ、IGF-l R以及IGFBP-3检测,并统计结直肠腺瘤不同组织类型和结直肠癌不同Dukes分期的阳性表达差异。结果:结直肠癌组织中IGF-Ⅱ、IGF-l R以及IGFBP-3表达均呈高阳性率,并且显著高于其他3组(P0.05)。结直肠腺瘤管状、混合型、绒毛状等不同组织类型IGF-Ⅱ、IGF-l R以及IGFBP-3表达阳性率呈逐渐增高趋势,绒毛状腺瘤显著高于其他两型(P0.05)。45例结直肠癌中,Dukes分期A、B两期显著低于C期和D期,比较差异具有显著性(P0.05)。结论:IGF-Ⅱ、IGF-l R以及IGFBP-3可能在结直肠腺瘤发生、发展及进展为结直肠癌的过程中起一定作用,对结直肠癌早期诊断具有一定价值。     

Cryo-EM reveals a previously unrecognized structural protein of a dsRNA virus implicated in its extracellular transmission

Mosquito viruses cause unpredictable outbreaks of disease. Recently, several unassigned viruses isolated from mosquitoes, including the Omono River virus (OmRV), were identified as totivirus-like viruses, with features similar to those of the Totiviridae family. Most reported members of this family infect fungi or protozoans and lack an extracellular life cycle stage. Here, we identified a new strain of OmRV and determined high-resolution structures for this virus using single-particle cryo-electron microscopy. The structures feature an unexpected protrusion at the five-fold vertex of the capsid. Disassociation of the protrusion could result in several conformational changes in the major capsid. All these structures, together with some biological results, suggest the protrusions’ associations with the extracellular transmission of OmRV.