土地利用/覆被变化对生物栖息地连接度的影响——以巩义地区黄鼬、蒙古兔和黄喉貂为例

土地利用/覆被变化通过改变生物栖息地而对物种分布产生影响。以河南省巩义市为研究区域,选取分布在该区域的哺乳动物黄鼬(Mustela sibirica)、蒙古兔(Lepus tolai)和黄喉貂(Martes flavigula)为目标物种,首先依据其生物特性和生态需求,确定了这3个物种的扩散能力;其次,基于景观连接度原理,分析了1990—2011年研究区土地利用整体变化和各类型变化情况,及其对单一物种和多物种栖息地连接度变化的影响。研究结果表明:(1)土地利用整体变化使得栖息地连接度增加,变化范围为22.22%—45.46%;(2)各土地利用类型变化对栖息地连接度的影响差异显著,连接度的升高和降低与栖息地斑块面积增加和减少密切相关;(3)基于多目标物种栖息地整体连接度空间分布图,确定了研究区目标物种保护的关键区域。     

稳定、无抗药的痢疾福氏2a和宋内双价菌苗候选株的构建

通过体内外基因重组,将大肠杆菌粘附因子cs3基因定位整合到痢疾杆菌福氏2a疫苗株T32菌染色体的asd基因内,使asd基因灭活;将来内O抗原基因克隆至无抗药性表达载体pXL378,获得重组质粒pXL390,将其转化asd-的T32受体菌,构建成福氏2a和宋内双价苗苗株FS01。实验表明:重组质粒pXL390在不带任何抗菌素基因的情况下,在asd-的T32受体菌内是稳定的。FS01株遗传稳定,能表达两种痢疾菌的PLS-O抗原,无明显毒性作用。动物试验表明,以FS01株皮下免疫的小鼠对福氏2a和宋内有毒株的腹腔攻击有100％的保护。     

赤潮过程中“藻-菌”关系研究进展

微生物对促进海洋物质循环,维持水生环境的生态平衡具有重要作用。在赤潮事件中,基于微生物(尤其是细菌)的多样性和重要性,它们与藻类之间的相互关系成为了研究的热点。过去20年里,人们从不同角度对"藻-菌"间的关系进行了探索,包括物理学过程、生物学过程、环境过程以及化学过程。就化学过程而言,它作为一种较早出现的技术,在以往的研究中带给人们许多认识藻菌关系的方法。随着学科的渗透,化学法有了拓展与延伸,为人们认识藻菌关系带来了新的契机。从化学生态学领域来梳理"藻-菌"关系中涉及的现象和行为,包括菌对藻的有益面、菌对藻的有害面、以及藻类应答细菌行为的化学途径;并从信号语言(群体感应、化感作用)的角度来阐释两者之间的互生或克生关系。通过文献综述的方式来解读藻菌关系的互作过程和机理,为认识赤潮的发生和防控方法提供借鉴。     

我国湿地生态状况评价研究进展

从湿地生态状况评价定义、国际重要湿地和全国重点湿地生态状况和主要评价方法等方面研究综述了我国湿地生态状况评价。对全国1413处湿地生态状况的研究显示,国际重要湿地生态状况总体较好,重点湿地生态状况较差,生态状况差有341处,占24.85%,并系统分析了各类湿地生态状况评价的方法、内容和结果。认为湿地生态状况评价是满足湿地保护管理需求的一项基本技术研究工作,开展湿地生态状况评价可以从不同空间、时间尺度反映湿地生态变化趋势,满足湿地生态系统保护修复的管理要求,并揭示各生态因子的内在关系,是提高湿地的保护、管理和合理开发的重要技术手段。最后分析了当前湿地生态状况评价所面临的难点,并提出了相关对策建议。     

StxB／HlyA（CT）融合蛋白的分泌表达和StxB在小鼠内的特异免疫反应

本文将志贺氏毒Ｂ亚单位（ＳｔｘＢ）与大肠杆菌溶血素Ａ的Ｃ末端（ＨｌｙＡ（ＣＴ））相融合,蛋白ＳｔｘＢ／ＨｌｙＡ（ＣＴ）不仅能在大肠杆菌中分泌到胞外,而且也能从ａｒｏＡ突变的减毒鼠伤寒沙门氏菌中分泌出去。当用高拷贝质粒ｐＵＣ１８作载体时,上述融合蛋白对宿主细胞有毒性,但以低拷贝质粒ｐＢＲ３２２取代之后,该融合蛋白不再对窠主细胞产生任何不利影响。融合蛋白ＳｔｘＢ／ＨｌｙＡ（ＣＴ）无论是在ａｅｒｏｂａｃ     

大兴安岭和长白山地区蜜环菌生物种的研究

从大兴安岭和长白山采集到30号蜜环菌(Armillaria mellea)标本,选其中有代表性的10个号的担子果获得单孢株。交配试验表明每一担子果都具有双因子异宗配合系。不同子实体交配型之间交配结果表明,在大兴安岭和长白山地区蜜环菌目前至少存在5个生物种,分别称为生物种A、B、C、D和E。将这5个生物种的单孢菌种与欧洲5个蜜环菌生物种的单孢菌株进行配合,生物种B与欧洲A.gallica,生物种E与欧洲A.ostoyae亲和交配,因此将生物种B和E分别定为A.gallica和A.ostoyae。生物种A、C和D则不与任何欧洲生物种交配。     

Construction of a trivalent candidateShigella vaccine strain with host-vector balanced-lethal system

A trivalent liveShigella vaccine candidate FSD01 against S.flexneri 2a, S.sonnei and S.dysenteriae I was constructed. This candidate strain was based on the S.flexneri 2a vaccine T32. By homologous recombination exchange, the chromosomalasd gene of T32 was site-specifically inactivated, resulting in the strain unable to grow normally in LB broth, while anotherasd gene of S.mutans was employed to construct an Asd⁺ complementary vector. This combination ofasd ^- host/Asd⁺ vector formed a balanced-lethal expression system in T32 strain. By use of this system, two important protective antigen genes coding for S.sonnei Form I antigen and Shiga toxin B subunit were cloned and expressed in T32, which led to the construction of trivalent candidate vaccine FSD01. Experimental results showed that this strain was genetically stable, but its recombinant plasmid was non-resistant. Moreover, it was able to effectively express trivalent antigens in one host and induce protective responses in mice against the challenges of the above threeShigella strains.     

死亡分析（1990年人口普查资料分析）

本文定义了期内死亡数和龄内死亡数的概念,并给出了从现时人口统计资料中汇总准确年龄人口数,期内死亡数和龄内死亡数的方法。本文给出了现时人口寿命分布的极大似然估计,从而给出了现时人口寿命表各参数的严格的概率意义,并利用１９９０年人口普查资料的１０％抽样数据,求得中国（男、女）寿命表。     

Tat Peptide-Mediated Soluble Expression of the Membrane Protein LSECtin-CRD in Escherichia coli

The human liver and lymph node sinusoidal endothelial cell C-type lectin (hLSECtin), a type II integral membrane protein, containing a Ca²⁺-dependent carbohydrate recognition domain (CRD), has a well-established biological activity, yet its three-dimensional structure is unknown due to low expression yields and aggregation into inclusion bodies. Previous study has demonstrated that the HIV-1 virus-encoded Tat peptide (‘YGRKKRRQRRR’) can increase the yields and the solubility of heterologous proteins. However, whether the Tat peptide could promote the high-yield and soluble expression of membrane proteins in Escherichia coli is not known. Therefore, the prokaryotic expression vector pET28b-Tat-hLSECtin-CRD (using pET28b and pET28b-hLSECtin-CRD as controls) was constructed, and transformed into E. coli BL21 (DE3) cells and induced with isopropyl-β-d-thiogalactoside (IPTG) followed with identifying by SDS-PAGE and Western blot. Subsequently, the bacterial subcellular structure, in which overexpressed the heterologous proteins Tat-hLSECtin-CRD and Tat-free hLSECtin-CRD, was analyzed by transmission electron microscope (TEM) respectively, and the mannose-binding activity of Tat-hLSECtin-CRD was also determined. Expectedly, the solubility of Tat-LSECtin-CRD significantly increased compared to Tat-free LSECtin-CRD (**p < 0.01) with prolonged time, and the Tat-LSECtin-CRD had a significant mannose-binding activity. The subcellular structure analysis indicated that the bacterial cells overexpressed Tat-hLSECtin-CRD exhibited denser region compared with controls, while dot denser region aggregated in the two ends of bacterial cells overexpressed Tat-free hLSECtin-CRD. This study provided a novel method for improving the soluble expression of membrane proteins in prokaryotic systems by fusion with the Tat peptide, which may be potentially expanded to the expression of other membrane proteins.     

Systematic construction and validation of an immune prognostic model for lung adenocarcinoma

Lung adenocarcinoma (LUAD), the most common non‐small‐cell lung cancer, is characterized by a dense lymphocytic infiltrate, which indicates that the immune system plays an active role in the development and growth of this cancer. However, no investigations to date have proposed robust models for predicting survival outcome for patients with LUAD in terms of tumour immunology. A total of 761 LUAD patients were included in this study, in which the database of The Cancer Genome Atlas (TCGA) was utilized for discovery, and the Gene Expression Omnibus (GEO) database was utilized for validation. Bioinformatics analysis and R language tools were utilized to construct an immune prognostic model and annotate biological functions. Lung adenocarcinoma showed a weakened immune phenotype compared with adjacent normal tissues. Immune‐related gene sets were profiled, an immune prognostic model based on 2 immune genes (ANLN and F2) was developed with the TCGA database to distinguish cases as having a low or high risk of unfavourable prognosis, and the model was verified with the GEO database. The model was prognostically significant in stratified cohorts, including stage I‐II, stage III‐IV and epidermal growth factor receptor (EGFR) mutant subsets, and was considered to be an independent prognostic factor for LUAD. Furthermore, the low‐ and high‐risk groups showed marked differences in tumour‐infiltrating leucocytes, tumour mutation burden, aneuploidy and PD‐L1 expression. In conclusion, an immune prognostic model was proposed for LUAD that is capable of independently identifying patients at high risk for poor survival, suggesting a relationship between local immune status and prognosis.