测定胸腺肽含量几种定量方法的比较

本文用凯氏定氮法、双缩脲法及福林－酚法测定了胸腺肽含量,并加以比较,说明三种方法对其含量测定没有显著差异．在实践中可以根据不同条件选择适当的方法进行实验．     

胃泌素释放肽受体与妇科肿瘤的诊断与治疗

胃泌素释放肽GRP(gastrin-releasing peptide,GRP)作为一种生长因子可以在许多肿瘤组织表达,GRP与肿瘤中的受体GRPR结合后,可启动一系列信号传导通路及基因调控机制,从而促进肿瘤细胞的增殖.GRPR在正常组织和肿瘤组织中的激活作用有重要的生长效应.且在恶性肿瘤中的表达比在正常的人体组织更为普遍.以GRPR作为靶向治疗已有一定的理论支持,但临床研究不多.本文着重要阐述的是关于GRPR与妇科肿瘤的诊断与治疗的关系并展望了其前景.     

Aptamer selection for the detection of Escherichia coli K88

In this study, the first group of single-stranded DNA aptamers that are highly specific to enterotoxigenic Escherichia coli (ETEC) K88 was obtained from an enriched oligonucleotide pool by the SELEX (Systematic Evolution of Ligands by Exponential Enrichment) procedure, during which the K88 fimbriae protein was used as the target and bovine serum albumin as counter targets. These aptamers were applied successfully in the detection of ETEC K88. They were then grouped under different families based on the similarity of their secondary structure and the homology of their primary sequence. Four sequences from different families were deliberately chosen for further characterization by fluorescence analysis. Having the advantage of high sensitivity, fluorescence photometry was selected as single-stranded DNA quantification method during the SELEX process. Aptamers with the highest specificity and affinity were analyzed to evaluate binding ability with E. coli. Since ETEC K88 is the only type of bacterium that expressed abundant K88 fimbriae, the selected aptamers against the K88 fimbriae protein were able to specifically identify ETEC K88 among other bacteria. This method of detecting ETEC K88 by aptamers can also be applied to bacteria other than ETEC K88.     

应用意愿价值评估法评价河流生态恢复的时间稳定性——以上海城市内河为例

意愿价值评估法 (CVM)的评估结果是否具有时间稳定性是其可靠性检验中的重要问题,决定其能否应用于我国的生态系统服务价值评估.本文以上海城市内河生态恢复为评估对象,设计相隔1个月和2年的3次意愿价值评估方案,分别对3次调查的426、498和200份问卷进行了对比分析.结果表明： 3次支付意愿均值分别为14.2、14.1和18.0元,中位数分别为5、5和10元.进一步对支付意愿分布和主要统计值、影响因素、模型时间变量的显著性分析结果表明,相隔1个月的CVM 结果具有时间上的稳定性,而相隔2年的CVM 结果表现出一定差异.     

不同碳源对须糖多孢菌生长发育及丁烯基多杀菌素生物合成的影响

本文研究了不同碳源对须糖多孢菌生长以及丁烯基多杀菌素生物合成的影响,通过寻找优势碳源优化发酵培养基配方,促进须糖多孢菌丁烯基多杀菌素的生物合成。试验共设11个处理,1个对照,通过单因素试验比较不同处理组菌体OD600值和丁烯基多杀菌素产量,筛选获得最优碳源及其发酵培养基配方。结果表明,除可溶性淀粉和木糖外,须糖多孢菌在9种碳源中都能进行生长,对不同构型碳源显示较好的利用率。在以半乳糖、葡萄糖、果糖和甘露糖作为碳源时具有较好的生长速率,而以甘露糖为碳源时能显著促进丁烯基多杀菌素的合成。选择甘露糖最佳添加浓度为5 g/L,须糖多孢菌最高菌体浓度和丁烯基多杀菌素产量分别是初始配方条件的1. 32倍和1. 78倍,显著提高了丁烯基多杀菌素的产量。上述结果为培养基碳源对丁烯基多杀菌素生物合成影响机制的研究及丁烯基多杀菌素大规模工业化发酵生产提供了科学依据和新的技术途径。     

Species traits and climate velocity explain geographic range shifts in an ocean‐warming hotspot

Species' ranges are shifting globally in response to climate warming, with substantial variability among taxa, even within regions. Relationships between range dynamics and intrinsic species traits may be particularly apparent in the ocean, where temperature more directly shapes species' distributions. Here, we test for a role of species traits and climate velocity in driving range extensions in the ocean‐warming hotspot of southeast Australia. Climate velocity explained some variation in range shifts, however, including species traits more than doubled the variation explained. Swimming ability, omnivory and latitudinal range size all had positive relationships with range extension rate, supporting hypotheses that increased dispersal capacity and ecological generalism promote extensions. We find independent support for the hypothesis that species with narrow latitudinal ranges are limited by factors other than climate. Our findings suggest that small‐ranging species are in double jeopardy, with limited ability to escape warming and greater intrinsic vulnerability to stochastic disturbances.