河流干支流水质与土地利用的相关关系

为探索不同等级河流水质状况及其对土地利用构成响应的差异,以江苏北部的灌河流域为研究对象,基于2006—2007年两个年度灌河及其支流的水质监测数据和研究区的Landsat TM影像,在河流两侧长度0.0—10.0 km、宽度0.0—0.5 km的范围内,运用多元回归分析,对研究区干、支流主要水质指标及其与相应土地利用构成的关系进行了研究。结果表明:2006—2007年间,研究区干流水质总体上显著好于支流,支流的总氮(TN)、总磷(TP)等营养盐指标显著高于干流,而干流的有机污染指标显著高于支流;比较不同观测尺度上土地利用构成对河流水质变化的方差贡献率发现,缓冲区宽度一定时,支流在所有观测尺度上的土地利用构成与水质变化皆存在显著相关关系,而干流仅在缓冲区长度0.0—4.0 km的观测尺度上其土地利用构成与水质变化的相关关系显著;缓冲区长度一定时,干、支流河道两侧0.0—0.3 km间土地利用状况对水质变化的解释能力较大。同时发现,氮、磷等营养盐浓度多与较大尺度上的土地利用构成相关,而化学需氧量(COD)、生化需氧量(BOD)等多与较小尺度上的土地利用构成相关。研究结果显示,有必要区分不同河流等级,选择适宜的观测尺度,分别研究不同水质指标与土地利用构成间的相关关系。     

DNA damage accumulation and repair defects in acute myeloid leukemia: implications for pathogenesis,disease progression,and chemotherapy resistance

DNA damage repair mechanisms are vital to maintain genomic integrity. Mutations in genes involved in the DNA damage response (DDR) can increase the risk of developing cancer. In recent years, a variety of polymorphisms in DDR genes have been associated with increased risk of developing acute myeloid leukemia (AML) or of disease relapse. Moreover, a growing body of literature has indicated that epigenetic silencing of DDR genes could contribute to the leukemogenic process. In addition, a variety of AML oncogenes have been shown to induce replication and oxidative stress leading to accumulation of DNA damage, which affects the balance between proliferation and differentiation. Conversely, upregulation of DDR genes can provide AML cells with escape mechanisms to the DDR anticancer barrier and induce chemotherapy resistance. The current review summarizes the DDR pathways in the context of AML and describes how aberrant DNA damage response can affect AML pathogenesis, disease progression, and resistance to standard chemotherapy, and how defects in DDR pathways may provide a new avenue for personalized therapeutic strategies in AML.     

Clinical study of autologous cytokine-induced killer cells for the treatment of elderly patients with diffuse large B-cell lymphoma

To evaluate the effectiveness and safety of autologous cytokine-induced killer (CIK) cells in elderly patients with diffuse large B-cell lymphoma. Peripheral blood mononuclear cells (PBMC) were isolated from nine elderly patients with diffuse large B-cell lymphoma. PBMCs were augmented by priming with interferon gamma (IFN-γ) followed by IL-2 and monoclonal antibody (mAb) against CD3. Autologous CIK cells (range 5 × 10(9)-1 × 10(10)) were then infused back to individual patients; infusion was repeated every 4 weeks for 32 weeks (eight cycles). Patients were assessed for changes in lymphocyte subgroup, tumor-related biological parameters, imaging characteristics, the condition of remission, quality of life (QOL), and survival. Prior to CIK infusion, two patients were in complete remission and seven patients were in partial remission. After autologous CIK cell transfusions, the proportion of CD3+, CD3+CD8+, and CD3+CD56+ cells were significantly increased compared with baseline (P < 0.05); whereas serum levels of β2-microglobulin and LDH were significantly decreased (P < 0.05). The lymphoma symptoms were reduced and QOL was improved (P < 0.05) in all patients. All patients achieved complete remission at study endpoint. No adverse reactions were reported. Autologous CIK cell immunotherapy is safe and efficacious for the treatment of elderly patients with diffuse large B-cell lymphoma.     

基于GIS的外来入侵植物调查规划与外业实施

前期规划对外来入侵植物野外调查工作的顺利开展至关重要。本文将基于GIS的野外调查规划方法和入侵植物调查技术规范相结合, 利用地图资源丰富、分析功能强大的LocaSpace Viewer和奥维互动地图, 形成有针对性的野外调查规划方案。具体操作流程包括: (1)借助LocaSpace Viewer软件集成的高分辨率遥感数据和地理标注数据选取调查区域; (2)根据调查规范, 通过该软件的空间分析和地理要素编辑功能, 规划调查地理网格、调查点、样地、标准地和样方, 运用KML空间数据格式存储和分享调查规划信息; (3)在外业实施中使用移动版奥维互动地图软件的数据管理和导航功能实现调查规划信息的导入、定位和导航。通过在福建、广西和云南三省开展技术方法的实地应用与对比实验发现, 运用该方案的外业实施能够达到日平均调查6个样点, 采集调查数据80多条, 直线调查距离180 km, 调查点导航精度大于15 m。对比实验表明基于规划调查比未规划调查在时间利用效率上提高1倍, 工作效率得到显著提升。该方案为外来入侵植物的发生和危害等基础性调查工作提供了高效的技术支撑, 为生物多样性野外调查规划提供了参考方案。     

Inter-chain disulfide bond improved protein trans-splicing increases plasma coagulation activity in C57BL/6 mice following portal vein FVIII gene delivery by dual vectors

Protein trans-splicing based dual-vector factor VIII(FVIII) gene delivery is adversely affected by less efficiency of protein splicing.We sought to increase the amount of spliced FVIII protein and plasma coagulation activity in dual-vector FVIII transgene in mice by means of strengthening the interaction of inteins,protein splicing elements,thereby facilitating protein trans-splicing.Dual-vector delivery of the FVIII gene in cultured cells showed that replacement of Met226 in the heavy chain and Asp1828 in the light chain with Cys residues could facilitate inter-chain disulfide linking and improve protein trans-splicing,increasing the levels of spliced FVIII protein.In this study,C57BL/6 mice were coadministered dual vectors of intein-fused human FVIII heavy chain and light chain with Cys mutations via portal vein injection into the liver.Forty-eight hours post-injection,plasma was collected and analyzed for FVIII antigen concentration and coagulation activity.These mice showed increased circulating FVIII heavy chain polypeptide(442±151 ng mL-1 vs.305±103 ng mL-1) and coagulation activity(1.46±0.37 IU mL-1 vs.0.85±0.23 IU mL-1) compared with control mice co-administered dual vectors expressing the heavy and light chains of wild-type FVIII.Moreover,coagulation activity was similar to that of mice receiving a single vector expressing FVIII(1.79±0.59 IU mL-1).These findings indicate that improving protein trans-splicing by inter-chain disulfide bonding is a promising approach for increasing the efficacy of dual-vector based FVIII gene transfer.     

冷蒿种群在放牧干扰下遗传多样性的变化

通过随机扩增多态性 DNA(RAPD)方法检测了放牧干扰下冷蒿种群遗传多样性的变化。 17条 (组 )引物进行 RAPD分析 ,扩增共产生 2 5 4条带 ,其中 2 4 0条为多态性带 ,多态位点百分率达 94 .4 9%。随着放牧强度的增加 ,冷蒿种群多态位点百分数 ,Nei遗传多样性指数、Shannon信息指数均下降 ,种群内个体平均遗传一致度增加。放牧梯度上 4个冷蒿种群 H t=0 .2 116 ,Hs=0 .170 0 ,Dst=0 .0 4 16 ,种群间基因分化系数 Gst=0 .196 5 ,基因流 N*m=2 .0 4 5 1;同时随着放牧强度的增加 ,种群间的 Dst、Gst增加 ,N*m 降低。说明放牧限制了种群间的基因交流 ,使种群发生遗传分化。放牧梯度上的 4个冷蒿种群的遗传距离很小 ,但是随着放牧强度的增加 ,遗传距离在缓慢的增加 ,种群间的遗传一致度降低。根据遗传距离所构建的 U PGMA聚类图中冷蒿 4个种群随着牧压的增加 ,逐级聚在一起。这表明冷蒿种群的遗传分化与放牧强度的关系     

甲基单胞菌Methylomonas sp.GYJ3中甲烷单加氧酶还原酶组分的纯化和性质

Ｍｅｔｙｌｏｍｏｎａｓｓｐ．ＧＹＪ３菌的甲烷单加氧酶（ＭＭＯ）粗酶提取液经ＤＥＡＥ－ＳｅｐｈａｒｏｓｅＣＬ－６Ｂ阴离子交换层析、ＳｅｐｈａｄｅｘＧ－１００凝胶过滤层析和ＤＥＡＥ－ＴＳＫｇｅｌＨＰＬＣ分离纯化出ＭＭＯ还原酶组分．经ＨＰＬＣ分析,纯度大于９５％,纯化倍数为４．４,加入至ＭＭＯ羟基化酶和调节蛋白Ｂ的体系中表现比活为２２８ｎｍｏｌ环氧丙烷每分钟毫克蛋白．ＳＤＳ－ＰＡＧＥ电泳表明还原酶由一种亚基组成,分子量４２ｋＤ．ＩＣＰ－ＡＥＳ测定还原酶的Ｆｅ含量为１．８３ｍｏｌＦｅ每ｍｏｌ蛋白．ＵＶ－Ｖｉｓ光谱表明还原酶除２８０ｎｍ蛋白质特征峰外在４６０ｎｍ有最大吸收峰,且Ａ２８０ｎｍ／Ａ４６０ｎｍ为２．５０,与其它黄素一铁硫蛋白相似,推测还原酶可能含一个ＦＡＤ辅基和Ｆｅ２Ｓ２中心．在厌氧条件下,还原酶能够和ＮＡＤＨ作用,ＵＶ－Ｖｉｓ光谱分析表明还原酶４６０ｎｍ处特征吸收峰消失,说明在ＭＭＯ催化过程中还原酶接受ＮＡＤＨ的电子．ＤＥＡＥ－ＳｅｐｈａｒｏｓｅＣＬ－６Ｂ阴离子交换层析分离出调节蛋白Ｂ,部分纯化的调节蛋白Ｂ的分子量大约在２０ｋＤ,它能够提高ＭＭＯ比活性４０倍,ＭＭＯ还原酶和调节蛋白Ｂ单独存在时不具有ＭＭＯ     

PCR-SSCP技术在假丝酵母属菌种鉴别中的应用

选取中国工业微生物菌种保藏管理中心(CICC)保藏的假丝酵母属的7个种30株菌, 对其rDNA的ITS1区及ITS2区进行了PCR-SSCP指纹图谱分析, 结果表明在假丝酵母属种水平的区分鉴定中, ITS1区与ITS2区的PCR-SSCP图谱均能对本研究所选7个种的菌株进行显著区分, 比较两个区段的PCR-SSCP图谱及鉴别效果, 发现ITS2区的应用效果要优于ITS1区。     

城市生态风险评价研究进展

随着城市化发展和城市人居环境的恶化,城市生态风险越来越受到关注,但尚缺乏有关城市生态风险评价的深入系统研究.本文依据城市生态学原理及生态风险评价框架从驱动力、风险源、风险受体与评价终点,以及生态风险综合评价方法等方面对城市生态风险评价研究进行综述.指出城市经济社会活动类型与程度是城市生态风险产生的主要驱动力;城市生态系统不同等级功能实体和城市整体是城市生态风险评价中的风险受体;城市生态风险评价终点包括城市生态系统结构、过程、功能要素,以及城市整体水平的性质和功能变化;耦合了社会经济需求的生态系统模型是城市生态风险评价方法的发展方向.未来城市生态风险评价研究应明确生态风险管理具体目标,确定综合性评价终点,建立多指标评价体系和综合评价方法.