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Protein & Cell 2010年第4期1卷 363-370页

作者： Xue Yao Shasha Fang Wentao Qiao yunqi geng Yuequan Shen Tianjin Key Laboratory of Protein Science College of Life SciencesNankai University94 Weijin RoadTianjin 300071China Key Laboratory of Molecular Microbiology and Biotechnology(Ministry of Education) the College of Life ScienceNankai University94 Weijin RoadTianjin 300071China

Integrase plays a critical role in the recombination of viral DNA into the host ***,over the past decade,it has been a hot target of drug design in the fight against type 1 human immunodeficiency virus(HIV-1).Bovine immunodeficiency virus(BIV)integrase has the same function as HIV-1 *** have determined crystal structures of the BIV integrase catalytic core domain(CCD)in two different crystal forms at a resolution of 2.45Åand 2.2Å,*** crystal form I,BIV integrase CCD forms a back-to-back dimer,in which the two active sites are on opposite *** has also been seen in many of the CCD structures of HIV-1 integrase that were determined ***,in crystal form II,BIV integrase CCD forms a novel face-toface dimer in which the two active sites are close to each ***,the distance separating the two active sites is approximately 20Å,a distance that perfectly matches a 5-base pair *** on these data,we propose a model for the interaction of integrase with its target DNA,which is also supported by many published biochemical *** results provide important clues for designing new inhibitors against HIV-1.

关键词： bovine immunodeficiency virus integrase catalytic core domain crystal structure dimerization

Borf-1 protein identified as a transcriptional trans-activator of bovine foamy virus

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Chinese Science Bulletin 1999年第11期44卷 1017-1021页

作者： Jiajian Liu Shuhong Liu Qimin Chen yunqi geng Nankai Univ Coll Life Sci Tianjin 300071 Peoples R China

Bovine foamy virus (BFV), a member of the spumavirus subfamily of retroviruses,contains two open reading frames (ORF-1 and ORF-2) in addition to the genes coding for gag,po/and env. Borf-1 protein, encoded by BFV ORF-1, is identified as a transcriptional transactivator, which augments gene expression directed by the viral long terminal repeat (LTR).Further investigations in transient expression assays reveal that the Borf-1 responsive elements are located in the U3 domain of the LTR, upstream from position -140 ( + 1 represents the transcription initiation site), and the BFV RU5 region has an inhibitory effect in LTR-directed gene expression.

关键词： bovine foamy virus (BFV )3026 China Strain transcriptional trans-activator transient expression assay.

MicroRNAs and their role in viral infection

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Frontiers in Biology 2007年第1期2卷 15-20页

作者： MU Junjie YAO Xue CHEN Qimin geng yunqi QIAO Wentao College of Life Science and Tianjin State Laboratory of Microbial Functional Genomics Nankai UniversityTianjin 300071China

Recently,a class of about 22 nucleotides(nt)small RNA has been discovered in many eukaryotes,termed microRNAs(miRNAs),which have a variety of *** recent findings have demonstrated that viruses can also encode their own ***,other findings reveal a relationship between host miRNA and viral *** findings suggest a tight relationship between host and viral infection via miRNA *** article introduces the miRNAs encoded by viruses and reviews the advances of the interaction of the mammalian host miRNAs and viral infection.

关键词： microRNA(miRNA) viral infection small RNA

cis-acting element located in the bovine foamy virus internal promoter possesses the properties of a transcrip-tional enhancer

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Chinese Science Bulletin 2002年第13期47卷 1108-1112页

作者： Wentao Qiao Chunguang Guo Shuhui Wang Jinzhong Wang Qimin Chen yunqi geng Nankai Univ Coll Life Sci Tianjin 300071 Peoples R China

Bovine foamy virus encodes a transcriptional transactivitor, Tas or Borf-1, which governs the level of viral transcripts initiated by both the promoter in the long terminal repeat (LTR) and the internal promoter (IP) located in the env gene through their cis-acting targets. We have identified and characterized a 72 bp TBS (Borf-1) responsive element located in BFV3026, internal promoter (TREIP) by deletion mutant and transient expression assay. This cis-acting target element in the internal promoter has the properties of a transcriptional enhancer which functions independently of its orientation, position and also in heterologous promoters (BFV LTR and bovine immunodeficiency virus, BIV LTR). Alignments reveal that there are positional similarity and sequence homology among BFV TREIP, SFV-1 TREIP proximal element and SFV-3 TREIPH, which suggests that this kind of cis-acting elements possesses some common functional character.

关键词： bovine foamy virus (BFV) internal promoter (IP) Tas responsive element (TRE) enhancer.

Membrane-spanning domain of bovine foamy virus transmembrane protein having cytotoxicity

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Frontiers in Biology 2006年第4期1卷 353-356页

作者： MA Yonggang YU Hong WANG Jinzhong CHEN Qimin geng yunqi College of Life Sciences Nankai UniversityTianjin 300071China

Foamy viruses(FVs)have broad cellular tropism infecting vertebrates from fish to human being,which indicates that Env protein has a high capability for membrane *** features in all FV transmembrane(TM)proteins include a region of hydrophobic domain called membrane-spanning domain(MSD),which contains several stretches of hydrophobic amino *** investigate whether these features were associated with the cytotoxicity effect of TM on Escherichia coli,a series of mutants were constructed and expressed in the *** BL21(DE3)using pET-32a(+)as expressing *** results showed that only TM3 without MSD was expressed in ***,whereas the other two containing full or part of the MSD(TM1 and TM2)could not be ***,the bacterial amount and living bacteria analysis revealed that the cytotoxicity of TM was dependent on its MSD,especially on the stretches of hydrophobic amino *** blotting analysis showed that TM3 protein was purified with affinity purification.

关键词： bovine foamy virus(BFV) membrane-spanning domain(MSD) cytotoxicity

On the structure of AP-4 responsive element in the LTR of Jembrana disease virus

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Chinese Science Bulletin 2003年第2期48卷 1247-1250页

作者： Zijing Liu Hongyan Yin Gang Deng Yuhua Yuan Jinzhong Wang yunqi geng Qimin Chen Nankai Univ Coll Life Sci Tianjin 300071 Peoples R China

Previous studies with deletion and sequence analysis of JDV LTR showed that there is a putative AP-4 responsive element in LTR. By antisense transient assay and gel shifting assay, we for the first time demonstrated that AP-4 modulated JDV gene expression by binding DNA di-rectly to bovine cells. The results, derived from site-directed mutagenesis experiments, suggest that the six base pairs of AP-4 binding site (CAGCTG) have different effects on JDV gene expression. When the first two base pairs changed to GC, JDV gene expression is severely decreased.

关键词： JDV cellular factor AP-4 trans-activator (Tat) LTR site-directed mutagenesis.

Characterization of a full-length infectious clone of bovine foamy virus 3026

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Virologica Sinica 2014年第2期29卷 94-102页

作者： Tiejun Bing Hong Yu Yue Li Lei Sun Juan Tan yunqi geng Wentao Qiao Key Laboratory of Molecular Microbiology and Biotechnology (Ministry of Education) and Key Laboratory of Microbial Functional Genomics (Tianjin) College of Life Sciences Nankai University Department of Molecular and Cellular Pharmacology the Vascular Biology Institute University of Miami School of Medicine National Laboratory of Biomacromolecules Center for Biological Imaging Institute of Biophysics Chinese Academy of Sciences

The biological features of most foamy viruses(FVs) are poorly understood, including bovine foamy virus(BFV). BFV strain 3026(BFV3026) was isolated from the peripheral blood mononuclear cells of an infected cow in Zhangjiakou, China. A full-length genomic clone of BFV3026 was obtained from BFV3026-infected cells, and it exhibited more than 99% amino acid(AA) homology to another BFV strain isolated in the USA. Upon transfection into fetal canine thymus cells, the full-length BFV3026 clone produced viral structural and auxiliary proteins, typical cytopathic effects, and virus particles. These results demonstrate that the full-length BFV3026 clone is fully infectious and can be used in further BFV3026 research.

关键词：感染性克隆牛泡沫病毒 BFV3026 外周血单核细胞表征细胞病变效应生物学特性胸腺细胞

Synthesis of Large-Area, Few-Layer Graphene on Iron Foil by Chemical Vapor Deposition

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Nano Research 2011年第12期4卷 1208-1214页

作者： Yunzhou Xue Bin Wu Yunlong Guo Liping Huang Lang Jiang Jianyi Chen Dechao geng yunqi Liu Wenping Hu Gui Yu Beijing National Laboratory for Molecular Sciences Key Laboratory of Organic Solids Institute of Chemistry Chinese Academy ofSciences Beijing 100190 China

我们表明一个简单、可控制的方法综合大区域，由优化化学蒸汽免职(CVD ) 的铁底层上的很少层 graphene 用甲烷和氢的混合物的方法。基于 Fe-C 阶段图的分析，为 Fe 表面上的 graphene 的成功的合成的一个合适的过程被设计。适当温度和... 详细信息

我们表明一个简单、可控制的方法综合大区域，由优化化学蒸汽免职(CVD ) 的铁底层上的很少层 graphene 用甲烷和氢的混合物的方法。基于 Fe-C 阶段图的分析，为 Fe 表面上的 graphene 的成功的合成的一个合适的过程被设计。适当温度和冷却过程被发现在高度水晶的很少层 graphene 的合成很重要。基于 Graphene 的地效果晶体管(联邦货物税) 设备用产生很少层 graphene 被制作，并且与 3001150 cm2/ 的提取活动性显示出好质量(V 敢椠 ?? 敤瑢吗？

关键词：化学气相沉积合成过程石墨铁箔面积相图分析 Fe-C 冷却过程

Structural engineered living materials

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Nano Research 2024年第2期17卷 715-733页

作者： Yang geng Zian Jia Ling Li 635 Prices Fork Road Department of Mechanical EngineeringVirginia Polytechnic Institute and State UniversityBlacksburg VA24061USA

Biological structural materials not only exhibit remarkable mechanical properties but also often embody dynamic characteristics such as environmental responsiveness,autonomy,and self-healing,which are difficult to achieve in conventional engineering *** merging materials science,synthetic biology,and other disciplines,engineered living materials(ELMs)provide a promising solution to combine living organisms with abiotic components,thus facilitating the construction of functional“living”*** natural materials,ELMs possess vitality and hold immense application potential in areas such as medicine,electronics,and construction,captivating increasing research attention *** an emerging branch of ELMs,structural ELMs aim to mimic living biological structural materials by achieving desired mechanical performance while maintaining important“living”*** we summarize the recent progress and provide our perspectives for this emerging research *** first summarize the superiority of structural ELMs by reviewing biological structural materials and biomimetic material design ***,we provide a systematic discussion on the definition and classifications of structural ELMs,their mechanical performance,and physiological ***,we summarize some critical challenges faced by structural ELMs and highlight directions of future *** hope this review article can provide a timely summary of the state of the art and relevant perspectives for future development of structural ELMs.

关键词： structural materials engineered living materials(ELMs) structural ELMs composites mechanical properties

Mixed Dead-time Effect Suppression Strategy for Modular Multilevel Converters

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CSEE Journal of Power and Energy Systems 2024年第3期10卷 1075-1084页

作者： Zhi geng Minxiao Han School of Electrical and Electronic Engineering North China Electric Power UniversityBeijing 102206China IEEE

Dead time is necessary for the coupled power switches to prevent shoot-through,especially in the modular multilevel converters(MMCs)with a large number of power *** paper proposes a dead-time effect suppression strategy for MMCs with nearest level *** operational principles of MMCs are first *** to the operational features of MMCs,the method that removes a switching signal from the coupled switches and the reduced switching frequency voltage balancing algorithms(RSFVBAs)are mixed in the proposed *** the intervals that are furthest away from the zerocrossing points(ZCP)of arm currents,the single switching signal method can completely eliminate the dead-time effect(DTE).Alternatively,the DTE is suppressed by the RSFVBA in intervals that are close to the *** the combination of the two methods,the dependence of the DTE suppression method on currents is reduced and the influences of ZCP are also released without degrading the normal operation performance of ***,the output performance of MMCs is improved and the voltage stress on the arm inductor dramatically ***,the validation of the method is verified by the simulation results with the professional tool Matlab/Simulink.

关键词： Dead-time effect modular multilevel converters switching frequency voltage balancing algorithm