Characterization and application of nucleocapsid protein of porcine reproductive and respiratory syndrome virus expressed in E.coli

从已构建的PRRSV ORF7重组质粒pUCm-T-ORF7中用PCR扩增ORF7基因亚克隆至表达载体pGEX-4T-3,构建重组表达质粒pGEX-4T-3-ORF7并转化大肠杆菌。经SDS-PAGE及Western blotting鉴定,成功表达了谷胱苷肽转移酶(GST)融合的核衣壳蛋白(N),重组N蛋白表达量约为菌体总蛋白的35%,主要以可溶的形式存在,且能形成同源二聚体。重组N蛋白经谷胱苷肽凝胶(glutathione sepharose 4B)亲和层析后得到高度纯化,并将该蛋白作为抗原建立了间接ELISA检测方法。利用该方法对某猪场76份猪血清进行检测并将结果与IDEXX公司ELISA试剂盒检测结果作比较,2种方法的总符合率达93.4%,检测结果之间差异不显著(P>0.05)。结果表明大肠杆菌表达的重组GST融合N蛋白具有良好的抗原性,因而有望利用该重组蛋白开发为试剂盒应用于临床PRRSV抗体的检测。Porcine reproductive and respiratory syndrome virus(PRRSV) FJ-1 was a newly identified virus isolate in Fujian province.The ORF7 gene of FJ-1 was amplified by RT-PCR and cloned into vector pUCm-T,then subcloned into expression vector of pGEX-4T-3.The recombinant GST-tagged nucleocapsid protein(rN) was expressed in E.coli and the molecular weight was approximately 38 000 as identified by SDS-PAGE and Western blotting.Expression level of the rN protein was approximately 35% of the total bacterial protein and mostly soluble.The rN protein was purified to homogeneity using GST affinity chromatography.Analysis of the rN protein under nonreducing conditions revealed that similar to native protein,the rN protein also possesses homo-dimerization property.An indirect enzyme-linked immunosorbent assay(ELISA) for detecting PRRSV antibody was developed using the purified rN protein as antigen.76 serum samples were detected by the method and the result was compared with that using IDEXX PRRS HerdChek ELISA kit.An identity of 93.4% was revealed between the two ELISA kits and no significant difference(P>0.05) was detected.The data indicate the rN protein has the potential usefulness for detection of the PRRSV antibodies.福建省科技攻关计划重点资助项目(2003N083);; 厦门市科技攻关计划重点资助项目(3502Z20031054

中国海及邻近区域碳库与通量综合分析

中国海总面积约470万平方公里,纵跨热带、亚热带、温带、北温带等多个气候带.其中,南海北依\"世界第三极\"青藏高原、南邻\"全球气候引擎\"西太平洋暖池,东海拥有全球最宽的陆架之一,跨陆架物质运输显著,黄海是冷暖流交汇区域,渤海则是受人类活动高度影响的内湾浅海.中国海内有长江、黄河、珠江等大河输入,外邻全球两大西边界流之一的黑潮.这些鲜明的特色赋予了中国海碳储库和通量研究的典型代表意义.文章从不同海区（渤海、黄海、东海、南海）、不同界面（陆-海、海-气、水柱-沉积物、边缘海-大洋等）,以及不同生态系统（红树林、盐沼湿地、海草床、海藻养殖、珊瑚礁、水柱生态系统等）多层面对海洋碳库与通量进行了较系统地综合分析,初步估算了各个碳库的储量与不同碳库间的通量.就海气通量而言,渤海向大气中释放CO2约0.22Tg Ca-1,黄海吸收CO2约1.15Tg Ca-1,东海吸收CO2约6.92～23.30Tg Ca-1,南海释放CO2约13.86～33.60Tg Ca-1.如果仅考虑海-气界面的CO2交换,中国海总体上是大气CO2的\"源\",净释放量约6.01～9.33Tg Ca-1.这主要是由于河流输入以及邻近大洋输入所致.河流输入渤黄海、东海、南海的溶解无机碳（DIC）分别为5.04、14.60和40.14Tg Ca-1,而邻近大洋输入DIC更是高达144.81Tg Ca-1,远超中国海向大气释放的碳量.渤海、黄海、东海、南海的沉积有机碳通量分别为2.00、3.60、7.40、7.49Tg Ca-1.东海和南海向邻近大洋输送有机碳通量分别为15.25～36.70和43.39Tg Ca-1.就生态系统而言,中国沿海红树林、盐沼湿地、海草床有机碳埋藏通量为0.36Tg Ca-1,海草床溶解有机碳（DOC）输出通量为0.59Tg Ca-1;中国近海海藻养殖移出碳通量0.68Tg Ca-1,沉积和DOC释放通量分别为0.14和0.82Tg Ca-1.总计,中国海有机碳年输出通量为81.72～103.17Tg Ca-1.中国海的有机碳输出以DOC形式为主,东海向邻近大洋输出的DOC通量约15.00～35.00Tg Ca-1,南海输出约31.39Tg Ca-1.综上,尽管从海-气通量看中国海是大气CO2的\"源\",但考虑了河流、大洋输入、沉积输出以及微型生物碳泵（DOC转化输出）作用后,中国海是重要的储碳区.需要指出的是,文章数据是基于中国海各海区碳循环研究报道,鉴于不同研究方法上的差异,所得数据难免有一定的误差范围,亟待将来统一方法标准下的更多深入研究和分析.国家重点研发计划项目(编号:2016YFA0601400);;国家自然科学基金项目(批准号:91751207、91428308、41722603、41606153、41422603);;中央高校基础研究项目(编号:20720170107);;中海油项目(编号:CNOOC-KJ125FZDXM00TJ001-2014、CNOOCKJ125FZDXM00ZJ001-2014)资

南海北部神狐海域沉积物颗粒对天然气水合物聚集的主要影响

An important parameter is the saturation of gas hydrate within the sediment pore for evaluating its impact on energy, climate and environment. So it is significant of understanding which factors affecting the saturation of gas hydrates. There is a good r

The methane hydrate accumulation controlled compellingly by sediment grain at Shenhu, northern South China Sea

An important parameter is the saturation of gas hydrate within the sediment pore for evaluating its impact on energy, climate and environment. So it is significant of understanding which factors affecting the saturation of gas hydrates. There is a good r

Visual inertial measurement unit based inertial guide sample estimation method

本发明提出了一种基于惯性引导采样的视觉IMU方向估计方法，即利用IMU的方向估计信息，引导视觉方向估计中匹配点对的采样过程和误匹配点的移除过程。包括基于增益自适应互补滤波器的IMU方向估计、基于尺度旋转不变的特征检测以及基于视觉IMU融合的方向估计三个步骤。本发明方法采用增益自适应互补滤波器，能够在初始迭代过程中剔除明显的误匹配点对，提高了方向估计的准确性；将IMU的姿态估计信息作为初值引入到视觉方向估计中，通过迭代移除误匹配点对，加快了方向估计的进程，有效避免了采用随机初始值带来的运算量大的问题。本发明方法适用性广、鲁棒性好、准确率高，可广泛应用在人体康复训练的动作捕捉过程中