Varma R.S在微波促进有机化学反应中的研究进展

微波辐射促进化学反应是一个新的技术．本文综述了近年来Varma R．S先生在该领域中的研究概况．     

黄体酮透皮吸收研究

本文针对黄体酮透皮吸收过程中，影响黄体酮透过量的促渗剂因素，运用药物透皮吸收的试验方法和数学理论进行了深入的研究和探讨，建立了一个黄体酮透皮吸收体外试验模型，为黄体酮透皮治疗系统应用于临床铺平了道路。     

具全期启动子盒的杆状病毒高效表达载体的组建与应用

通过ＰＣＲ扩增，得到苜蓿丫纹夜蛾核型多角体病毒（ＡｕｔｏｇｒａｐｈａｃａｌｉｆｏｒｎｉｃａＮｕｃｌｅａｒＰｏｌｙｈｅｄｒｏｓｉｓＶｉｒｕｓ，ＡｃＮＰＶ）具早晚期启动子元件的ｐ３５基因启动子，将其插入到杆状病毒转移载体质粒ｐＳＸＩＶＶＩ＋Ｘ３多克隆位点上游，使之与ｐＳＸＩＶＶＩ＋Ｘ３质粒中的人工合成后期启动子（ＰＳｙｎ）、多角体ＸＩＶ启动子（ＰＸＩＶ）串联构成早期、晚期、极晚期能持续启动外源基因表达的转移载体质粒ｐＳＸ３５．将ｐＳＸ３５用于组建含ＨＢｓＡｇ基因并形成多角体的重组ＴｎＮＰＶ，ＨＢ－ｓＡｇ基因的表达量显著提高，表达时间亦明显提前，从而实现了外源基因在杆状病毒表达系统的全期、高效表达．ｍＲＮＡ引物延伸试验结果显示，Ｐｐ３５在重组病毒中可产生２套转录本，分别于病毒感染的早期和晚期起始ＨＢｓＡｇ基因的表达．     

Functional analysis of cis-acting sequences regulating root-specific expression in transgenic tobacco

Two different length fragments, RSF1 and RSF2 which contained the cis-acting sequences of root-specific gene TobRB7, were isolated from tobacco genome. The abilities of these fragments to direct root-specific expression were studied by fusing them to the β-glucuronidase (GUS) report gene with different directions. After the recombined vectors were transformed into tobacco, the expression pattern was performed by histochemical staining and the quantitative analysis of GUS activity. The data suggested that the cis-acting element of TobRB7 gene direct GUS expression not only as root-specific but also as bidirectional. In our studies, the short fragment, RSF2, performed stronger activity than RSF1 with any direction. The stronger activity of GUS expression was determined by reverse inserting of RSF1 or RSF2 than positive inserting.     

Identification of seed-specific promoter nap300 and its comparison with 7S promoter

By fusing seed-specific promoter nap300 with β-glucuronidase gene, it was found that this about 300bp DNA fragment was sufficient to direct seed-specific gene expression. The substitution mutation in both distB and proxB elements had a little effect on the expression efficiency and almost no effect on the organ-specific expression pattern. In the experiment designed to compare nap300 with 7S promoter, the result showed that tissue specificity for nap300 was higher than that for 7S, and its expression level was lower than 7S's. There was no big difference in their expression pattern, and the maximal activity stage for the two promoters was identical, which indicated they could be used simultaneously for expressing different foreign genes in seeds.     

Functional analysis of cis-acting sequences regulating root-specific expression in transgenic tobacco

Two different length fragments, RSF1 and RSF2 which contained the cis-acting sequences of root-spe- cific gene TobRB7, were isolated from tobacco genome. The abilities of these fragments to direct root-specific expression were studied by fusing them to the β-glucuronidase (GUS) report gene with different directions. After the recombined vectors were transformed into tobacco, the expression pattern was performed by histochemical staining and the quantitative analysis of GUS activity. The data suggested that the cis-acting element of TobRB7 gene direct GUS expression not only as root-specific but also as bidirectional. In our studies, the short fragment, RSF2, performed stronger activity than RSF1 with any direction. The stronger activity of GUS expression was determined by reverse inserting of RSF1 or RSF2 than positive inserting.     

Expression of ipt gene driven by tomato fruit specific promoter and its effects on fruit development of tomato

Fruit specific promoter (2A12) from Lycopersicom esculentum and cDNA of isopentenyl-transferase (ipt) from Ti plasmid of Agrobacterium tumerfaciens C58 were cloned by PCR procedure respectively. Two plant expression vectors with 2A12/gus or 2A12/ipt were respectively constructed. These two chimeric genes were transferred into tomato by Agrobacterium mediated procedure. The results of Southern hybridization showed that the fusion genes had been integrated into tomatoes. The result of gus histochemical staining showed that 2A12 had high fruit specific expressive capability in transgenic tomato. The ipt expression resulted in accumulation of high level of cytokinins (CTKs) in fruit lead to developmental changes in fruits and seeds. The fruit of ipt transformed tomato had the hyperplastic placenta with very few seeds or even seedless. The shelf life of transgenic fruits elongated for 1-2 weeks. The ratio of fruit set, the dry weight of fruit and the crude protein content in fruit were increased, while the soluble sugar of fruits decreased.     

绿色荧光蛋白(GFP)基因在短小芽孢杆菌中的组成型表达

采用PCR技术,亚克隆来自短小芽孢杆菌总基因组中的启动子活性片段F1,构建了一个大肠杆菌-短小芽孢杆菌穿梭表达载体pHY300-F1gfp,以缺失启动子的绿色荧光蛋白(GFP)基因为报告基因,检测了该片段在短小芽孢杆菌DX01菌株中的启动活性,在荧光显微镜下,观察到了明亮的绿色荧光,证实活性片段F1具有组成型启动子的功能,GFP基因在短小芽孢杆菌中实现了组成型表达．     

Tissue-specific expression of glutathione S-transferases induced by 2-tridecanone or quercetin in cotton bollworms, Helicoverpa armigera (Hübner)

The tissue-specific expression of glutathione S-transferases (GSTs) in the cotton bollworm and the expression level induced by 2-tridecanone and quercetin were examined using the methods of biochemistry and the quantitative PCR. The relative expression level of GST mRNA was unanimous with the GSTs activity conjugaging with 1-chloro-2, 4-dimitro-benzene (CDNB) in fat bodies,midguts, heads and integuments of cotton bollworms. The GSTs activity in fat bodies was the highest, then midguts, heads and integuments in turn, which was in consistent with the relative expression level of GST mRNA. The specific activity of GSTs and the relative expression level of GST mRNA could be significantly induced by 2-tridecanone and quercetin, and after the induction the order of the GSTs activity and the relative expression level of GST mRNA in the above four tissues in cotton bollworms was not different from the control.The induction of GSTs by 2-tridecanone was stronger than by quercetin in all four tissues, which was in accordance with the relative expression level of GST mRNA. It suggested that the increase of GSTs activity induced by plant allelochemicals was associated with the elevated expression of GST mRNA in cotton bollworms.     

K2O对Pt／γ—A12O3上CO选择性氧化反应的助催效应

采用等体积浸渍法制备Pt／γ—Al2O3催化剂，通过添加K2O考察其对改善富氢气氛中CO选择性氧化性能的影响。结果表明，当加入K2O的质量分数为0．034，且采取在负载Pt后再添加的方式时，可显著改善催化剂的低温活性，在120℃时CO转化率可达90％。降低富氢气中CO浓度有助于提高CO转化率。O2／CO增加也可提高CO转化率，但O2／CO的增加并不能提高CO氧化的选择性。为了同时得到CO高转化率和CO氧化高选择性，O2／CO(V：V)为1．0～1．8。用BET、XRD和CO—TPD等表征方法说明了K2O的助催效应。