非晶半导体超晶格薄膜的光声谱研究

本文对a-Si:H/a-SiN_x:H超晶格薄膜进行了光声谱研究.在光声谱中可以观察到由于量子尺寸效应所引起的吸收边“兰移”现象.将超晶格系列样品的光声谱与它们的光吸收谱以及本征硅的光声谱作了比较,研究表明,在a-Si:H/a-SiN_x:H超晶格中光生载流子(电子和空穴)的非辐射复合比本征硅要大得多.光生载流子在带间的跃迁主要属于辐射跃迁,在带尾间的跃迁,主要属于非辐射跃迁.     

病毒在生物进化中的重要意义

最早的原始 RNA 是地球上的第一批生命。逆转录 RNA 所产生的 DNA 是球上第一批以DNA 为遗传信息载体的生命祖先。当今的一切生物都重现着原始 RNA 的进化方式,即以基因的重排与重组作为产生物种多样化的手段。这些都可由当代病毒学的新发现中获得证据。     

DDR相关蛋白缺陷引起的原发性免疫缺陷表型研究进展

在细胞内可变区基因(多样化基因)连接区基因片段重组(variable(diversity)joining recombination,V(D)J)与免疫球蛋白的类别转换重组(class switch recombination,CSR)过程中会产生程序性DNA双链断裂(DNA double strand break,DSB).当检测到DSB发生时DNA损伤反应(DNA damage response,DDR)被启动.DDR缺陷的病人具有原发性免疫缺陷表型(primary immunodeficiency,PID).总结了V(D)J重组与CSR产生DDR的分子机制,综述了V(D)J重组与CSR过程中DDR相关蛋白缺陷引起的原发性免疫缺陷表型.     

Construction of recombinant industrial Saccharomyces cerevisiae strain with bglS gene insertion into PEP4 locus by homologous recombination

The bglS gene encoding endo-1,3-1,4-β-glucanase from Bacillus subtil＆ was cloned and sequenced in this study. The bglS expression cassette, including PGK1 promoter, bglS gene fused to the signal sequence of the yeast mating pheromone a-factor （MFals）, and ADH1 terminator with G418-resistance as the selected marker, was constructed. Then one of the PEP4 allele of Saccharomyces cerevisiae WZ65 strain was replaced by bglS expression cassette using chromosomal integration of polymerase chain reaction （PCR）-mediated homologous recombination, and the bglS gene was expressed simultaneously. The recombinant strain S. cerevisiae （SC-βG） was preliminarily screened by the clearing hydrolysis zone formed after the barley β-glucan was hydrolyzed in the plate and no proteinase A （PrA） activity was measured in fermenting liquor. The results of PCR analysis of genome DNA showed that one of the PEP4 allele had been replaced and bglS gene had been inserted into the locus of PEP4 gene in recombinant strains. Different endo-1,3-1,4-β-glucanase assay methods showed that the recombinant strain SC-βG had high endo-1,3-1,4-β-glucanase expression level with the maximum of 69.3 U/（h·ml） after 60 h of incubation. Meanwhile, the Congo Red method was suitable for the determination of endo-1,3-1,4-β-glucanase activity during the actual brewing process. The current research implies that the constructed yeast strain could be utilized to improve the industrial brewing property of beer.     

Design of nonuniform cosine-modulated filter-banks with the perfect-reconstruction property and arbitrary filter lengths

In this paper, a method is proposed to construct recombination nonuniform cosine-modulated filter banks (CMFBs) with a perfect-reconstruction property and with arbitrary filter lengths. In this filter bank (FB) structure, certain channels of an original M-channel uniform FB are merged by a set of transmultiplexers (TMUXs), yielding nonuniform outputs, and the length restrictions on the original CMFB and the recombination TMUXs are avoided, allowing them to have arbitrary filter lengths. By imposing certain improved matching conditions on the prototype filters, nonuniform FBs with arbitrary filter lengths and with good properties can be obtained. As a result, the flexibility of selecting modulation types and filter lengths is greatly increased in the design of recombination nonuniform CMFBs. Another benefit due to the flexibility is that the system delay can be reduced.     

丙型肝炎病毒核酸疫苗的研究

从丙型肝炎病人的阳性血清中提取出丙型肝炎病毒ＲＮＡ，通过ＲＴ－ＰＣＲ的方法获得丙型肝炎病毒Ｃ区基因片段。并将此片段克隆到真核细胞表达载体ｐｃＤＮＡ３．１（＋），得到重组质粒ｐｃＤＮＡ－ＨＣＶ／Ｃ，再将其通过肌肉注射免疫ＢＡＬＢ／小鼠后，小鼠产生了抗ＨＣＶ／Ｃ区抗体。     

ZnCdSe单量子阱中点缺陷附近由非辐射载子复合激活的点缺陷反应

本文对ＺｎＣｄＳｅ单量子阱中点缺陷附近由非辐射载子复合而激活的点缺陷反应作了研究．样品在不同温度下对荧光光谱随时间变化的测量表明，这种反应增强了辐射量子效率．实验结果与温度相关的点缺陷状态跃迁率模型相吻合，并得到该跃迁的激活能为０．４５ｅｖ．     

1MeV电子辐照GaAs/Ge太阳电池变温光致发光研究

对1 MeV电子辐照GaAs/Ge太阳电池在30~290K温度范围进行了变温光致发光光谱测量,分析了辐照电池样品的发光峰位、发光强度随温度的变化.并用Arrhenius方程对发光强度随温度的变化进行拟合,得出了辐照太阳电池的非辐射复合中心分别为H2(EV+0.41eV)和H3(EV+0.71eV).     

Establishment ofChlamydomonas reinhardtii chloroplast expression

An expression vector pACⅢ containing the chimeric gene HAV- VP3P1 and HCV-C gene has been constructed and transferred to C. reinhardtii by the biolistic method. The trans-formants have been identified by PCR, Southern-blotting, Northern-blotting and Western-blotting assays after selecting on resistant medium and incubating in the dark. The results show that the chimeric gene has replaced the chIL gene of C. reinhardtii chloroplast genome and expressed correctly under the control of the C. reinhardtii chloroplast double promoters 5' chlL-5' atpA. The analysis of SDS-PAGE indicates that the expressed protein accounts for 5.31 % of total soluble protein.     

穿山龙液泡H+-ATPase c亚基基因片段的克隆

利用抑制消减杂交（SSH）和SMART技术，构建了3年生和1年生穿山龙（Dioscorea nipponica）根组织mRNA群体间正向差减cDNA文库．从34个随机测序的cDNA克隆中，发现了1个编码液泡H^＋-ATPase（V-H^＋-ATPase）c亚基的克隆，并命名为DnvHAc1（Accession No：DN792564）．序列同源性分析表明，其cDNA序列长486bp，3’端具有PolyA结构，其编码的氨基酸序列（115个氨基酸残基）也与多种植物的液泡H^＋-ATPase c亚基（16kDa proteolipids）具有较高同源性，具有3个跨膜疏水结构域，结构域Ⅲ为功能保守的区域，有dicyclohexylcarbodimide（DCCD）结合位点，Glu-92在调节液泡H^＋-ATPase具有重要作用．该研究结果为克隆其全长基因和进一步研究其在薯蓣皂甙次生代谢生物合成中的功能提供了重要的实验基础．