中华鳖病原维氏气单胞菌的分子鉴定及分子分类学研究

气单胞菌是一类人和水产经济动物的严重致病菌,用分子进化手段鉴定一株分离自红脖子病甲鱼病灶部位的菌HBJY01,同时探讨气单胞菌的进化地位.克隆HBJY01的16S rRNA和gyrB基因,鉴定该菌的属种.用16S rRNA和gyrB基因通过构建系统进化树和计算序列两两间遗传距离的方法,探讨气单胞菌的进化地位.HBJY01的16S rRNA和gyrB基因与维氏气单胞菌的相应基因同源性最高,经分子鉴定为维氏气单胞菌.气单胞菌应独立于弧菌科,单独形成一个科,即气单胞菌科(Aeromonadaceae).     

江西丰城市汉族8对遗传性状的基因频率

为探究江西汉族部分遗传性状基因频率分布的特征,采用随机抽样方法对江西丰城市372例(男233例,女139例)汉族人群的眦褶、眼睑、鼻梁类型、鼻孔形状、下颌类型、耳垂类型、额头发际、发形8对遗传性状进行了调查.结果显示:眦褶、头发类型性别间差异有统计学意义;眼睑、鼻梁形状性别间差异有统计学意义;鼻孔、下颌、耳垂、发际性别间差异无统计学意义;内眦褶、鼻孔形状民族间差异较大,耳垂、下颌、发际、发形次之,鼻梁类型、眼睑民族间差异较小;与其它13个民族进行聚类分析结果显示,遗传性状的基因频率分布具有一定的地域性.     

基于16S rRNA和16S-23S rRNA基因间隔区序列探讨陆生和水生螺原体菌株的系统发生关系

采集江苏省养殖池塘内发病的中华绒螯蟹、克氏原螯虾和南美白对虾,利用已有螺原体16S rRNA和23S rRNA基因序列保守引物扩增并测序16S rRNA和16S-23S rRNA基因间隔区序列(ISRs).基于已获得的序列和GenBank中下载的螺原体序列分别进行同源性比对,比对的结果分别利用PAUP软件和MrBaye...     

Preparation of monoclonal antibody based indirect competitive ELISA for detecting 19-nortestosterone residue

19-Nortestosterone (NT) has been illegally used in horse racing to boost physical performance, and in animal husbandry to accelerate weight gain. To monitor the abuse of NT, our goal was to develop a commercial enzyme linked immunosorbent assay (ELISA) kit. For this purpose, hybridomas were prepared by fusing NS0 mouse myeloma cells with splenocytes isolated from immunized BALB/c mouse. Noncompetitive and competitive indirect ELISA were used to screen positive cell clones. To optimize the indirect competiti...     

Rapid growth and sterility of growth hormone gene transgenic triploid carp

Triploid carp (100%) with 150 (3n=150) chromosomes were obtained by crossing the females of improved tetraploid hybrids (♀, 4n=200) of red crucian carp (♀)×common carp (♂) with the males of diploid yellow river carp (♂, 2n=100). The crosses yielded transgenic triploid carp (positive triploid fish, 44.2% of the progeny) and non-transgenic triploid carp (negative triploid fish). Histological examination of the gonads of 24-month-old positive triploid fish suggested they were sterile and the fish were not able to produce mature gametes during the breeding season. Morphologically, both the positive and negative triploid fish were similar. They had a spindle-shaped, laterally compressed, steel grey body with two pairs of barbells. Most of the quantifiable traits of the triploid carp were intermediate between those of the two parents. The positive and negative triploid fish were raised in the same pond for 2 years. The mean body weight of the positive triploid fish was 2.3 times higher than the negative triploid fish. The weight of the largest positive triploid fish was 2.91 times higher than that of the largest negative triploid fish. Thus, we produced fast-growing transgenic triploid carp that have a reduced ecological risk because of their inability to mate and produce progeny.     

准一维量子线中电子的传导性

一条理想的量子线同一条无序量子线耦合在一起,理想链中能量为E的电子波函数,能被无序链中某些格点能量Vn,2在电子能量E附近的格点强烈散射.在Vn,2=E格点,能量为E的电子波函数能发生全反射,也就是"反共振效应".在无序度W较大时,随着W的增大,无序链中能够强烈影响周期链的格点数减少,这使得周期链中电子的局域长度增大,与数值计算结果一致.     

关于基因繁殖的反应扩散系统（0，1）解的定态分歧

作者应用谱理论和规范化LyapunovSchmidt约化方法研究了关于基因繁殖的反应扩散系统（0,1）解的定态分歧,在特征值的代数重数为1的情况下,在一定条件下得到了定态方程从二阶非退化奇点处分歧出的正则分歧解.     

多信道认知网络的直观信道感知策略

为了提高频谱利用率,认知无线电技术可使非授权用户在不影响授权用户正常通信的情况下,利用瞬时的频谱空穴满足自身通信需求。如何通过感知频谱及时有效地发现频谱空穴是一个至关重要的问题,尤其是对于多信道认知无线电网络。针对多信道认知无线电网络,该文在连续时间Markov链的信道占用模型基础上,根据信道状态可能发生变化的概率,提出了一个动态的直观信道感知策略,并考虑了感知周期的影响。仿真结果表明:在感知周期合适的情况下,该策略能够有效地发现并利用频谱空穴,并且比周期感知和随机感知策略消耗更少的能量用于感知。     

B群脑膜炎球菌lpxL2基因敲除突变株的构建及初步鉴定

 应用基因敲除技术的方法和原理,通过PCR扩增B群脑膜炎球菌lpxL2基因及载体pGBK T7上的Kan抗性片段,lpxL2片段与puc-18载体连接得到重组质粒msb-puc,以重组质粒msb-puc为基础,分别通过反向PCR和酶切2种方法构建lpxL2基因中间片段的缺失,并在缺失位点连入Kan抗性表达盒,从而得到重组质粒mpK,mpK转化B群脑膜炎球菌,并用PCR的方法对转化子进行初步筛选鉴定,初步确定突变株1株.本研究通过基因敲除MenB中LPS合成途径相关基因lpxL2的方法,降低LPS毒性,为B群脑膜炎球菌OMV疫苗的研发做了铺垫.     

基于二维区间Hash链的RFID安全协议

作为未来物联网(IOT)的核心技术之一,无线射频识别(RFID)系统由于设备的局限性而存在许多安全问题.在分析几种典型安全协议核心思想的基础上,提出了基于二维区间(two-dimensional region,TDR)Hash链的安全协议.该协议以区间划分的方式标识各链,从而提高了数据库的检索效率;同时,由于在协议中引入了随机性,RFID系统的安全性得到了进一步增强.