风洞技术

风洞技术是测定信息化学物质对昆虫行为影响研究中非常重要的实验手段,可为确定信息物质的浓度、配比提供参考,也可辅助诱芯的改进和诱捕器的设计。实际上风洞实验是一种信息物质田间应用前的室内模拟测试。风洞实验前要做好充分的准备,观察和记录的指标因测试的是性信息素还是植物挥发物而不同。本文重点介绍了风洞实验的具体操作步骤,列举了风洞技术在苹果蠹蛾Cydia pomonella多成分性信息素研究和葡萄藤蛾Lobesia botrana对葡萄主要挥发物的行为反应研究中的两个应用实例,最后还讨论了风洞与嗅觉仪的区别、风洞的优缺点,以及风洞的日常维护等。     

RNA干扰与技术

RNA干扰(RNA interference,RNAi)是由双链RNA诱导的、序列特异的基因沉默机制。它是自然存在于植物、线虫和果蝇中抵抗外来基因(包括病毒、转座子)入侵的方式。在哺乳动物细胞中,能够人工诱导RNA干扰,沉默有同源序列基因表达。这一新技术具有特异性、高效性。因此,正被用来研究人类基因组的功能、肿瘤和抗病毒感染等。     

The proton inventory technique

The proton inventory technique uses the dependence of enzymic reaction rate on the atom fraction of deuterium present in mixtures of protium oxide and deuterium oxide to deduce for simple cases the number of exchangeable hydrogenic sites that produce isotope effects, and the magnitude of the isotope effect generated at each site. For more complex cases, other information, such as the participation of more than a single step in limiting the rate, may be obtained. The background of the method, the conduct of the experiments and the interpretation of the results are briefly reviewed. The method is then illustrated in its application to various enzyme systems by a series of case histories.     

ChIA-PET技术

配对末端标签测序分析染色质相互作用(chromatin interaction analysis by paired-end tag sequencing,ChIA-PET)技术是一项在全基因组范围内分析远程染色质相互作用的新技术。它把染色质免疫沉淀(chromatin immunoprecipitation,ChIP)技术、染色质邻近式连接(chromatin proximity ligation)技术、配对末端标签(paired-endtag,PET)技术和新一代测序(next-generation sequencing)技术融为一体,在基因组三维折叠和套环状态下分析基因表达和调控。ChIA-PET技术已用于确定人乳腺腺癌细胞内雌激素受体a的结合位点之间的相互作用。随着更多蛋白质因子的发现及其抗体的应用,该技术可实时捕获全基因组范围内参与复制、转录过程的蛋白质因子结合位点以及结合位点间的相互作用,这对于阐明基因调控和疾病发生机制具有重大意义。     

The soil percolation technique

Summary 1) Technical details of the operation of the soil percolation technique are fully described.2) An adaptation of the technique to the measurement of the carbon dioxide output of soils is presented.3) The technique is discussed.