摘要：Objective: To screen a triple helix-forming oligodeoxyribonucleotide (TFO) that can bind HBV core promoter at target site with high affinity and specificity, and to observe the ability of manganese porphyrin modified TFO to combine and cleave HBV DNA. Methods: Similar homopurine domain (1 734 - 1 754) in HBV core promoter was selected as target sequence. Several corresponding TFOs were synthesized. The affinities and specificities of TFOs binding target sequence were tested with electrophoretic mobility shift and DNase I footprinting assays. The selected best TFO was modified with manganese porphyrin and acridine. The ability of the TFO derivative to cleave HBV DNA was observed with cleavage experiment. Results: Under the condition of 371 and pH 7. 4, the TFO consisting of cytidylate and thymidylate (CT-TFO) and the parallel TFO consisting of guanylate and thymidylate (GT-TFOp) bound the target sequence weakly with Kd values much more than 10 -6 mol/L. The affinities of anti-parallel GT-TFO ( GT-TFOap) and short TFO consisting of adenine nucleotide and guanylate (AG-TFOsh) binding the target sequence were higher than those of the formers, with Kd values of 5 μ 10-7 mol/L and 2. 5 μ 10-8 mol/L respectively. Long AG-TFO (AG-TF01) had the highest binding affinity with a Kd value of 3 μ 10 -9 mol/L among all the TFOs studied for sequence specificity. In the presence of potassium monopersulfate, KHSO5, TFO modified with manganese porphyrin and acridine cleaved the target sequence where the triplex DNA formed. Conclusion: TFO containing AG or GT binds homopurine in HBV core promoter in adverse parallel direction to form triple helix. AG-TFO1 has the highest binding affinity among all the TFOs studied. After modified with manganese porphyrin, AG-TFO1 completely binds and cleaves the target HBV DNA sequence where triplex DNA is formed.

摘要：开发商选择宁波江北湾头姚江的末端段,总投资额约3亿元人民币,兴建了目前宁波市城区内最大的城市公园--日湖公园,这是一个针对原有湖水利用的案例.其东起大庆南路延伸段,南到通途路,西界湖滨路,北接环城北路,占地43.6公顷.设计者充分利用水的流动、多变、渗透、聚散、蒸发等特性,做到动静相补、声色相衬、虚实相应、层次丰富,产生了特殊的艺术魅力,主要表现在以下几个方面.

摘要：本文介绍一种无线遥控开关和插座断电报警装置的设计方法,并对该装置的结构和工作原理进行了详细的说明。本设计采用315MHz稳频无线电遥控组件及其他外围设备来组装遥控开关,利用继电器点触去控制其他电路。考虑到开关的安全性,在开关旁边加了一个报警装置,用以提醒用户在突然断电的情况下关掉开关或者拔掉插头。