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Characterization on the Mean Molar Absorptivity of Amino Acids in Microbial Lipopeptides

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Chinese Chemical Letters 2006年第4期17卷 517-520页

作者： Shi Zhong YANG Tao CHEN Bo Zhong MU dong zhi wei Department of Chemistry East China University of Science and Technology Shanghai 200237 Bioengineering Institute East China University of Science and Technology Shanghai 200237

The molar absorption coefficients of each of 14 kinds of amino acids were determined by the spectrophotometric method, and the mean molar absorption coefficients of 37 different mixtures of each with amino acid composition exactly equivalent to that of the peptide chain of the corresponding lipopeptide were determined based on calculation or experimental. The significance of the results is that the mean molar absorption coefficients strongly demonstrate the regular patterns, though different amino acids bear quite different molar absorption coefficients.

关键词： Molar absorption coefficient lipopeptide amino acid spectrophotometry,

Enzymatic synthesis of nucleosides by nucleoside phosphorylase co-expressed in Escherichia coli

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Journal of Zhejiang University-Science B(Biomedicine & Biotechnology) 2010年第11期11卷 880-888页

作者： Qing-bao DING Ling OU dong-zhi wei Xiao-kun wei Yan-mei XU Chun-yan ZHANG State Key Laboratory ofBtoreactor Engmeering East Chma Untverstty of Science and Technology Shanghai 200237 China Shanghai Scibest Biotechnology Co. Ltd. Shanghai 200235 China

Nucleoside phosphorylase is an important enzyme involved in the biosynthesis of nucleosides. In this study, purine nucleoside phosphorylase and pyrimidine nucleoside phosphorylase were co-expressed in Escherichia coli and the intact cells were used as a catalyst for the biosynthesis of nucleosides. For protein induction, lactose was used in place of isopropyl β-D-l-thiogalactopyranoside （IPTG）. When the concentration of lactose was above 0.5 mmol/L, the ability to induce protein expression was similar to that of IPTG. We determined that the reaction conditions of four bacterial strains co-expressing these genes （TUD, TAD, DUD, and DAD） were similar for the biosyntheses of 2,6-diaminopurine nucleoside and 2,6-diaminopurine deoxynucleoside. When the substrate concentration was 30 mmol/L and 0.5% of the recombinant bacterial cell volume was used as the catalyst （pH 7.5）, a greater than 90% conversion yield was reached after a 2-h incubation at 50℃. In addition, several other nucleosides and nucleoside derivatives were efficiently synthesized using bacterial strains co-expressing these recombinant enzymes.

关键词： Nucleoside phosphorylase Lactose Enzymatic synthesis

Cloning of 3H11 mAb variable region gene and expression of 3H11 human-mouse chimeric light chain

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World Journal of Gastroenterology 1998年第1期4卷 46-49页

作者： LI Jing WANG Yan LI Quan-Xi WANG Ya-Ming XU Jian-Jun dong zhi-wei 不详

IM To clone mouse antihuman gastric cancer mAb(3H11) variable genes and to construct 3H11 humanmouse chimeric antibody.METHODS The entire VH and VL genes of antigastric cancer mAb 3H11 were cloned by RTPCR method from 3H11 hybridoma cells, using 5′ primers for leader sequences. The 3H11 VL gene was then inserted into humanmouse chimeric light chain expression vector and transfected into murine Sp2/0 myeloma cells.RESULTS DNA sequence analysis indicated that the cloned genes included the whole leader sequences and the mature Ig variable region encoding sequences. After gene transfection, transient expression of chimeric light chain protein was detected.CONCLUSION DNA sequences and transient expression indicated that the cloned gene was functional. This work laid basis for constructing 3H11 humanmouse chimeric antibody in the future..

关键词： gene,expression stomach neoplasms antibodies,monoclonal chimeric antibody

Improving the biotransformation efficiency of soybean phytosterols in Mycolicibacterium neoaurum by the combined deletion of fbpC3 and embC in cell envelope synthesis

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Synthetic and Systems Biotechnology 2022年第1期7卷 453-459页

作者： Liang-Bin Xiong Hao-Hao Liu Lu Song Miao-Miao dong Jie Ke Yong-Jun Liu Ke Liu Ming Zhao Feng-Qing Wang dong-zhi wei Jiading District Central Hospital Affiliated Shanghai University of Medicine and Health Sciences Shanghai201800PR China State Key Laboratory of Bioreactor Engineering Newworld Institute of BiotechnologyEast China University of Science and TechnologyShanghai200237PR China Huawei Safety Evaluation&Medical Research(Shanghai)Co. Ltd.Shanghai201206PR China

Biotransformation of soybean phytosterols into 9α-hydroxy-4-androstene-3,17-dione(9-OHAD)by mycobacteria is the core step in the synthesis of adrenocortical ***,the low permeability of the dense cell envelope largely inhibits the overall conversion efficiency of *** antigen 85(Ag85)complex encoded by fbpA,fbpB,and fbpC was proposed as the key factor in the combined catalysis of mycoloyl for producing mycolyl-arabinogalactan(m-AG)and trehalose dimycolate(TDM)in mycobacterial cell ***,we confirmed that fbpC3 was essential for the biotransformation of trehalose monomycolate(TMM)to TDM in Mycolicibacterium *** deficiency of this gene raised the cell permeability,thereby enhancing the steroid uptake and *** 9-OHAD yield in the fbpC3-deficient 9-OHAD-producing strain was increased by 21.3%.Moreover,the combined deletion of fbpC3 and embC further increased the 9-OHAD yield compared to the single deletion of ***,after 96 h of bioconversion in industrial resting cells,the 9-OHAD yield of 11.2 g/L was achieved from 20 g/L phytosterols and the productivity reached 0.116 g/L/*** summary,this study suggested the critical role of the fbpC3 gene in the synthesis of TDM in *** and verified the feasibility of improving the bioconversion efficiency of phytosterols through the cell envelope en-gineering strategy.

关键词： Mycolicibacterium 9-OHAD Cell permeability Soybean phytosterol fbpC3 embC

In situ One-Pot Fabrication of MoO3-x Clusters Modified Polymer Carbon Nitride for Enhanced Photocatalytic Hydrogen Evolution

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Chinese Journal of Chemical Physics 2020年第4期33卷 491-499,I0002页

作者： Rong-jie Qi Jun-ying Liu zhi-dong wei wei-qi Guo zhi Jiang Wen-feng Shangguan Research Center for Combustion and Environmental Technology Shanghai Jiao Tong UniversityShanghai 200240China Center of Hydrogen Science Shanghai Jiao Tong UniversityShanghai 200240China

Developing low-cost and high-efficient noble-metal-free cocatalysts has been a challenge to achieve economic hydrogen *** this work,molybdenum oxides(MoO3-x)were in situ loaded on polymer carbon nitride(PCN)via a simple one-pot impregnation-calcination *** from post-impregnation method,intimate coupling interface between high-dispersed ultra-small MoO3-xnanocrystal and PCN was successfully formed during the in situ growth *** MoO3-x-PCN-X(X=1,2,3,4)photocatalyst without noble platinum(Pt)finally exhibited enhanced photocatalytic hydrogen performance under visible light irradiation(λ>420 nm),with the highest hydrogen evolution rate of 15.6μmol/h,which was more than 3 times that of bulk *** structure-performance revealed that such improvement in visible-light hydrogen production activity originated from the intimate interfacial interaction between high-dispersed ultra-small MoO3-xnanocrystal and polymer carbon nitride as well as efficient charge carriers transfer brought by Schottky junction formed.

关键词： Noble-metal-free cocatalyst Polymer carbon nitride MoO3-xclusters Schottky junction Photocatalytic hydrogen production

Multiplexed site-specific genome engineering in Mycolicibacterium neoaurum by Att/Int system

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Synthetic and Systems Biotechnology 2022年第3期7卷 1002-1011页

作者： Ke Liu Gui-Hong Lin Kun Liu Yong-Jun Liu Xin-Yi Tao Bei Gao Ming Zhao dong-zhi wei Feng-Qing Wang State Key Laboratory of Bioreactor Engineering Newworld Institute of BiotechnologyEast China University of Science and TechnologyShanghai200237China

Genomic integration of genes and pathway-sized DNA cassettes is often an indispensable way to construct robust and productive microbial cell *** some uncommon microbial hosts,such as Mycolicibacterium and Mycobacterium species,however,it is a ***,we present a multiplexed integrase-assisted site-specific recombination(miSSR)method to precisely and iteratively integrate genes/pathways with controllable copies in the chromosomes of Mycolicibacteria for the purpose of developing cell ***,a single-step multi-copy integration method was established in *** by a combination application of mycobacteriophage L5 integrase and two-step allelic exchange strategy,the efficiencies of which were~100%for no more than three-copy integration events and decreased sharply to~20%for five-copy integration ***,the R4,Bxb1 andΦC31 bacteriophage Att/Int systems were selected to extend the available integration toolbox for multiplexed gene integration ***,a reconstructed mycolicibacterial Xer recombinases(Xer-cise)system was employed to recycle the selection marker of gene recombination to facilitate the iterative gene *** a proof of concept,the biosynthetic pathway of ergothioneine(EGT)in Mycolicibacterium neoaurum ATCC 25795 was achieved by remodeling its metabolic pathway with a miSSR *** six copies of the biosynthetic gene clusters(BGCs)of EGT and pentose phosphate isomerase(PRT),the titer of EGT in the resulting strain in a 30 mL shake flask within 5 days was enhanced to 66 mg/L,which was 3.77 times of that in the wild *** improvements indicated that the miSSR system was an effective,flexible,and convenient tool to engineer the genomes of Mycolicibacteria as well as other strains in the Mycobacteriaceae due to their proximate evolutionary relationships.

关键词： Site-specific recombination Phage integrase Xer recombinases Mycolicibacterium Multi-copy integration

全腔输出相对论磁控管输出模式转换结构的理论设计和数值模拟

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物理学报 2018年第18期67卷 318-325页

作者：杨温渊董烨董志伟北京应用物理与计算数学研究所北京100094

采用全腔输出结构后,相对论磁控管径向尺寸显著减小,轴向长度也有较大幅度的缩短.但是,由于输出结构为三个相对独立的扇形波导,实际应用时,一般需要对微波输出模式进行转换.针对全腔输出相对论磁控管,本文研究了两种输出模式转换结构并... 详细信息

采用全腔输出结构后,相对论磁控管径向尺寸显著减小,轴向长度也有较大幅度的缩短.但是,由于输出结构为三个相对独立的扇形波导,实际应用时,一般需要对微波输出模式进行转换.针对全腔输出相对论磁控管,本文研究了两种输出模式转换结构并利用三维全电磁粒子模拟程序对其进行了研究.首先研究了将三个扇形波导角向增宽从而渐变或者突变为一个同轴波导的情况,研究结果表明,两种情况下输出微波功率均大于采用传统三个独立扇形波导输出时的90%,输出模式主要是TEM模.其次研究了输出区由三个扇形输出波导分别变换为三个截面大小与之接近的矩形输出波导的可行性,研究结果表明,注入扇形波导中的TE_(11)模式几乎全部转换为矩形波导中的TE_(10)模式.实际应用时,可根据需要选择上述输出模式转换结构.

关键词：相对论磁控管半透明阴极全腔耦合输出扇形波导

新型全腔输出半透明阴极相对论磁控管的理论和数值研究

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物理学报 2016年第24期65卷 235-243页

作者：杨温渊董烨董志伟北京应用物理与计算数学研究所北京100094

为减小器件的体积和重量,提高器件的实用性,在轴向渐变输出结构半透明阴极相对论磁控管的基础上,提出了全腔耦合输出结构半透明阴极相对论磁控管,并对其进行了理论分析和数值模拟.采用全腔输出结构后,器件互作用区径向半径由10.5 cm降到... 详细信息

为减小器件的体积和重量,提高器件的实用性,在轴向渐变输出结构半透明阴极相对论磁控管的基础上,提出了全腔耦合输出结构半透明阴极相对论磁控管,并对其进行了理论分析和数值模拟.采用全腔输出结构后,器件互作用区径向半径由10.5 cm降到6.6 cm,轴向长度由大于40 cm降到小于30 cm,器件尺寸显著减小.通过对输出结构的参数优化,在注入电子束电压和电流分别约为395 kV和5.6 kA、外加磁场为4.75 k Gs(1 Gs=10^(-4)T)时,模拟在S波段获得了效率约50%的微波输出,输出功率达到1.15 GW,模式更加纯净.同时还分析了耦合孔的长度、宽度和深度以及输出波导的宽度和短路面起始位置等参数对输出性能的影响规律.

关键词：相对论磁控管半透明阴极全腔耦合输出

Effect of arterioportal shunting in radical resection of hilar cholangiocarcinoma

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Chinese Medical Journal 2010年第22期123卷 3217-3219页

作者： CHEN Yong-liang HUANG zhi-qiang HUANG Xiao-qiang dong Jia-hong DUAN wei-dong LIU zhi-wei ZHANG Xuan LIANG Yu-rong CHEN Ming-yi Department of Hepatobiliary Surgery General Hospital of Chinese People's Liberation Army Beijing 100853 China

Background The resection and reconstruction of the hepatic artery is often required in radical surgery for hilar cholangiocarcinoma. In this study, we report our experience in performing arterioportal shunting as an alternative for the arterial reconstruction. Methods Four patients with hilar cholangiocarcinoma underwent extended left hepatectomy and caudate Iobectomy combined with en bloc resection of the hepatic artery and arterioportal shunting with restriction of the arterial caliber. The efficacy of arterioportal shunting was assessed by computed tomography angiography （CTA）. Results All the four patients recovered uneventfully without any complications. CTA showed a patent shunt and normal liver regeneration. No signs of portal hypertension were found at one year of follow-up. Conclusions Arterioportal shunting with restriction of the arterial caliber appears to be a feasible and safe alternative for the microvascular reconstruction after hepatic artery resection in radical surgery for hilar cholangiocarcinoma.

关键词： arterioportal shunting hilar cholangiocarcinoma restriction of the arterial caliber