伊蚊5-HT受体家族生物信息学分析和时空表达谱的构建

5-羟色胺(5-HT)可通过多个受体介导来调控昆虫的生长发育和运动等生理活动,也是新型杀虫剂潜在的靶点。本研究对埃及伊蚊的5-羟色胺受体家族进行系统分析,即利用生物信息学方法、进化分析5-HT受体在物种间的同源性,构建系统进化树;使用同源建模的方法以人类5-羟色胺受体结构为模板,构建埃及伊蚊(Aedes aegypti)5-HT受体的三维结构模型;通过实时荧光定量PCR方法研究受体在埃及伊蚊幼虫期、蛹期和成蚊,未吸血雌蚊的头、胸、腹及附肢的表达情况。从NCBI和VectorBase数据库中得到埃及伊蚊的6个5-HT受体基因,生物信息学分析发现6个受体结构均具有7次跨膜区,其中在受体蛋白的二级结构中α-螺旋占有较高的比重。进化分析结果表明,埃及伊蚊5-HT受体基因分别位于3个不同的分支,各分支均与黑腹果蝇5-HT相应受体具有较高的同源性。表达谱构建结果表明,相比各龄幼虫和雌蚊,5-HT受体均在雄蚊中的表达量最高,且在雌蚊各组织中呈现明显的差异。5-HTR1B、5-HTR2B、5-HTR7B在头、胸、腹和附肢4种组织中均有表达;5-HTR1A在头、胸、腹中均有表达;5-HTR1D在胸腔中高表达,但在头部和附肢中不表达;5-HTR7A在附肢中表达丰度最高,而在头部无表达;该结果预示不同受体介导5-HT的功能可能不同。本研究明确了埃及伊蚊5-HT受体家族蛋白的序列特征、进化关系及组织表达特征,为埃及伊蚊5-HT受体功能的进一步研究奠定了基础。

Solution properties and self-association of multi-blocks like copolymer P(AM/AA) prepared by template copolymerization

The association and properties of multi-block like copolymers(TP)of acrylamide(AM)and acrylic acid(AA)prepared by template copolymerization in aqueous solution were studied.The results showed that the copolymers of this type exhibited a significant structure effect compared with that of similar random copolymers(CP)obtained by copoly-merization in the absence of template.Decreasing the value of pH or adding Ca2+ion to the copolymer solution will make phase separation occur.The TEM images demonstrated that the phase separation caused by Ca2+ion was due to the forma-tion of extensively intermolecular cross-linking.With the increase of the pH value of copolymer solution,the changes of the solution viscosity was similar with that of homopoly-acrylic acid,which originally increased and then decreased.But the increase range of template copolymer was higher than that of homopolyacrylic acid.TEM images indicated that at the maximal viscosity the copolymer obtained in the presence of template formed coiled aggregates.

齿轮故障识别的密度峰值聚类欠定盲源分离算法

为提高盲源分离算法在振动源数目估计问题中的噪声鲁棒性,提出了一种基于密度峰值聚类的欠定盲源分离算法。对预处理后的信号提取单源点,通过密度峰值聚类对单源点进行聚类得到混合矩阵的估计值。通过基于压缩感知模型对源信号进行重构,得到分离信号。为验证所提算法分离准确性和噪声鲁棒性,用所提算法对不同信噪比下的仿真信号进行分离,结果显示:在信噪比不低于4 dB时,所提算法均可以准确分离出源信号,算法的准确性和鲁棒性得到验证。设计旋转部件故障诊断试验台对所提算法在实际应用中的有效性进行验证,对实测复合故障振动信号进行分离,试验结果表明该算法成功分离出观测信号中的锥齿轮和行星齿轮单一故障特征,有助于工程中旋转部件故障诊断。