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Structural basis for transcription initiation by E. coli σE

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Structural basis for transcription initiation by E. coli σE

中国生物化学与分子生物学会第十二届全国会员代表大会暨2018年全国学术会议

作者： Chengli Fang lingting li liqiang Shen Jing Shi Yu Feng Yu Zhang Key Laboratory of Synthetic Biology CAS Center for Excellence in Molecular Plant SciencesShanghai Institute of Plant Physiology and EcologyChinese Academy of Sciences University of Chinese Academy of Sciences Department of Biochemistry and Molecular Biology School of MedicineZhejiang University

Bacterial RNAP uses extra-cytoplasmic function(ECF) σ factors to regulate gene *** σ is a well-studied and vital ECF σ factor,which controls expression of a set of genes in response to various environmental and cellular events causing cell-envelop ***,it remains elusive how σ interacts with RNAP core enzyme,and how the σ-RNAP holoenzyme initiates transcription of its regulated *** this study,we have determined a cryo-EM structure of *** complex comprising σ(*** σ-RPo).The structure revealskey interactions essential for assembly of σ-RNAP holoenzyme and for promoter recognition and ***,the structure shows that the non-conserved linker region connecting N-terminal and C-terminal domains(σ2/σ4 linker) of σ threads into the active-center cleft and exits through the RNA exit *** bioinformatic,biochemical,and structural analysis suggest that the highly divergent σ2/σ4 linker of ECF σ factors probably interact with RNAP in the same mode and plays essential roles during transcription initiation.

关键词： RNA polymerase Extra-Cytoplasmic Function σ factors transcription initiation promoter recognition

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海南木豆丛枝植原体质粒全序列测定及分析

热带作物学报 2014年第7期35卷 1404-1408页

作者：李玲婷车海彦曹学仁杨毅罗大全中国热带农业科学院环境与植物保护研究所农业部热带作物有害生物综合治理重点实验室海南省热带农业有害生物监测与控制重点实验室海南海口571101

提取木豆叶片基因组总DNA,通过克隆,测序木豆丛枝植原体海南株系质粒(pPPWB-Hn)的完整DNA序列,并使用生物信息学软件对该质粒全长序列进行分析。分析结果显示:pPPWB-Hn质粒全长4 218 bp,含有4个开放阅读框,分别编码Rep、dnaG、threonine... 详细信息

提取木豆叶片基因组总DNA,通过克隆,测序木豆丛枝植原体海南株系质粒(pPPWB-Hn)的完整DNA序列,并使用生物信息学软件对该质粒全长序列进行分析。分析结果显示:pPPWB-Hn质粒全长4 218 bp,含有4个开放阅读框,分别编码Rep、dnaG、threonine synthase和未知蛋白。其中,Rep是2次跨膜蛋白,dnaG是单次跨膜蛋白,Rep和dnaG均与质粒自主复制有关。Rep和未知蛋白可能分布在细胞质中,dnaG可能定位到细胞膜上或膜外,Threonine synthase可能定位到线粒体膜上或线粒体内腔。系统进化树显示:pPPWB-Hn与植原体16SrⅡ组的pPNWB(AY270152),pTBBperi(DQ119297)及pTBBcap(DQ119296)处在同一进化分支。

关键词：木豆丛枝植原体质粒序列分析

动脉自旋标记联合区域性动脉自旋标记技术评估单侧大脑中动脉重度狭窄或闭塞患者侧支代偿

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中国医学影像技术 2024年第4期40卷 526-530页

作者：刘蒋静李晨林斌王玲廷周智鹏桂林医学院附属医院放射科广西桂林541001

目的观察动脉自旋标记(ASL)联合区域性ASL(t-ASL)技术评估单侧大脑中动脉(MCA)重度狭窄或闭塞患者侧支代偿的价值。方法回顾性选取52例单侧MCA重度狭窄或闭塞患者(病变组),根据相对脑血流量(rCBF)将其进一步分为侧支循环不良亚组(n=23... 详细信息

目的观察动脉自旋标记(ASL)联合区域性ASL(t-ASL)技术评估单侧大脑中动脉(MCA)重度狭窄或闭塞患者侧支代偿的价值。方法回顾性选取52例单侧MCA重度狭窄或闭塞患者(病变组),根据相对脑血流量(rCBF)将其进一步分为侧支循环不良亚组(n=23)及良好亚组(n=29);以55名健康体检者为对照组。基于ASL[标记后延迟时间(PLD)=1 525、2 525 ms]和t-ASL图像比较组间及病变组内亚组间脑血流量(CBF)、rCBF及CBF差值(PLD 2 525 ms下CBF-PLD 1 525 ms下CBF),观察侧支代偿来源;以Kendall相关性分析评估各参数与代偿的相关性。结果病变组患侧与对照组左侧CBF、CBF差值的差异及组间rCBF差异均有统计学意义(P均<0.001),且2组PLD=2 525 ms下CBF均大于PLD=1 525 ms(P均<0.05),病变组患侧CBF均小于对侧(P均<0.05)。病变组内2亚组间CBF差值、患侧CBF及rCBF差异(P均<0.001),以及侧支无代偿和对侧颈内动脉(ICA)+椎基底动脉(VBA)代偿占比差异均有统计学意义(P均<0.05)。病变组rCBF(PLD=2 525 ms)与存在VBA侧支代偿呈低度正相关(r=0.397,P=0.004)。结论 ASL联合t-ASL有助于评估单侧MCA狭窄或闭塞患者侧支代偿情况。

关键词：大脑中动脉狭窄闭塞侧支循环动脉自旋标记灌注成像

乡村振兴视域下温州职业教育“校企村”融合路径研究

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林业科技情报 2023年第4期55卷 186-188页

作者：厉玲婷谢华楣翁耀炜浙江安防职业技术学院浙江温州325016

近年来,地方职业院校助力乡村振兴已成常态。职业教育本身的功能定位与乡村振兴需求相契合,使得职业教育在培育乡村经济的推动者、乡土文化的传承者等方面大有可为。该研究通过探讨温州职业教育“校企村”融合发展的现实困境,提出相应策... 详细信息

近年来,地方职业院校助力乡村振兴已成常态。职业教育本身的功能定位与乡村振兴需求相契合,使得职业教育在培育乡村经济的推动者、乡土文化的传承者等方面大有可为。该研究通过探讨温州职业教育“校企村”融合发展的现实困境,提出相应策略,进而研究温州职业教育对服务产业兴农、培养农村专业人才和提供现代技术支撑等方面的外延应用。

关键词：温州职业教育乡村振兴校企村

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嗜水气单胞菌噬菌体(Yyong)的分离与基因组分析

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中国生物工程杂志 2024年第8期44卷 57-68页

作者：陈慧珏刘文才钱敏桦潘灵婷徐锦鹏李登峰童贻刚宁波大学海洋学院宁波315832 北京化工大学生命科学学院北京100029

目的:嗜水气单胞菌(Aeromonas hydrophila)的致病范围十分广泛,耐药现象日益普遍,危害鱼类、家畜和人类健康,有必要分离、鉴定烈性***噬菌体。方法:以*** Ah2为指示菌,用双层平板法从污水中分离获得烈性噬菌体Yyong。对其进行了电镜观... 详细信息

目的:嗜水气单胞菌(Aeromonas hydrophila)的致病范围十分广泛,耐药现象日益普遍,危害鱼类、家畜和人类健康,有必要分离、鉴定烈性***噬菌体。方法:以*** Ah2为指示菌,用双层平板法从污水中分离获得烈性噬菌体Yyong。对其进行了电镜观察、宿主范围检测、一步生长试验、全基因组测序、基因注释和系统进化分析。结果:Yyong呈肌尾病毒样,头部直径为(83±2)nm,尾部长度为(115±5)nm。基因组全长165663 bp,G+C含量为40.90%,含有16个tRNA基因和242个开放阅读框(ORF),含有诸多辅助代谢基因(AMGs),主要涉及DNA合成和抗氧化应激。有2个ORF分别被预测为编码毒素-抗毒素(toxin-antitoxin,TA)防御系统的毒素(PAAR重复蛋白)和抗毒素DarG,这有利于Yyong在细菌细胞内生存。有3个ORF分别被预测为编码σ因子、抗σ^(70)蛋白和σ^(70)诱饵,这些因子可能修饰RNA聚合酶使之优先识别噬菌体基因的启动子区域。在系统进化树中,与Yyong进化距离最小的病毒是Tulanevirus属的气单胞菌噬菌体。Yyong与它们间分享的最高平均核苷酸一致性(ANI)值和DNA分子杂交(isDDH)值分别是94.51%和53.30%,均小于定义一个种的边界值,与它们间分享的最大成对序列相似度值(PASC值)和基因组间相似度(VIRIDIC)值分别是90.51%和90.20%,均大于属的边界值;Tulanevirus属与Straboviridae科的另一个属Biquartavirus聚成一个枝簇(clade),它们共享的核心基因(core genes)占比为68.53%,符合国际病毒分类委员会(ICTV)关于建立一个亚科的标准(27%~79%)。结论:Yyong是一个新种,属于Tulanevirus属。建议在Straboviridae科下建立一个新亚科以包含Tulanevirus属和Biquartavirus属。Yyong携带数量和种类多样的AMGs和tRNA基因,使其有效地控制宿主细菌,高效合成噬菌体自身核酸和蛋白质。一些AMGs具有良好开发潜力。丰富了噬菌体基因数据库与噬菌体分类系统,为噬菌体功能基因研究和噬菌体研发奠定了基础。

关键词：分离基因组噬菌体嗜水气单胞菌辅助代谢基因新亚科

新型聚球藻噬藻体Yong-L2-223的分离及基因组分析

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微生物学报 2024年第1期64卷 189-207页

作者：胡嘉琪潘灵婷周钦钱敏桦蔡汝倩王飞任晓清林威李登峰童贻刚宁波大学海洋学院浙江宁波315000 北京化工大学生命科学与技术学院北京100029

【目的】噬藻体(cyanophages)是特异性侵染蓝藻(cyanobacteria)的病毒,广泛分布于各类水体中,在调节蓝藻种群动态和密度、推动生物地球水生生态系统循环中起着重要作用。本研究的目的在于分离、鉴定噬藻体。【方法】本研究以海洋聚球藻(... 详细信息

【目的】噬藻体(cyanophages)是特异性侵染蓝藻(cyanobacteria)的病毒,广泛分布于各类水体中,在调节蓝藻种群动态和密度、推动生物地球水生生态系统循环中起着重要作用。本研究的目的在于分离、鉴定噬藻体。【方法】本研究以海洋聚球藻(Synechococcus sp.)PCC 7002为指示宿主,从淡水水样中分离培养一株新型噬藻体Yong-L2-223,对其进行了宿主范围实验、全基因组测序、基因功能注释和系统进化分析。【结果】针对31株供试蓝藻的宿主范围实验,结果除指示藻PCC 7002[属于聚球藻目(Synechococcales)]外,Yong-L2-223能够感染2株淡水蓝藻,分别是来源于滇池的绿色微囊藻(Microcystis viridis)FACHB-1342[属于色球藻目(Chroococcales)]和水华束丝藻(Aphanizomenon flos-aquae)FACHB-1209[属于念珠藻目(Nostocales)]。既可在高盐条件下感染海洋蓝藻,又可在低盐条件下感染淡水蓝藻,Yong-L2-223具有广盐性。透射电镜观察表明,Yong-L2-223呈肌尾病毒样(myovirus-like),头部直径约60nm,尾部长约136nm。Yong-L2-223的双链DNA基因组全长为65725bp,G+C含量为58.6%,含有100个开放阅读框(openreading frame,ORFs)。Yong-L2-223基因组中含有编码Cas4、基因转移因子(gene transfer factor,GTA)的基因,含有辅助代谢基因(auxiliary metabolic genes,AMGs),含有pre-Q0生物合成基因簇(gene cluster)。这些基因的编码产物可能有助于该噬藻体对宿主的适应、感染,从而实现跨3个目(order)感染蓝藻。将Yong-L2-223基因组与现有数据库中所有病毒基因组进行序列配对比较(pairwise sequence comparison,PASC),结果最高PASC值仅为3.78%,远远低于国际病毒分类委员会(International Committee on Taxonomy of Viruses,ICTV)界定属的边界值(70%)。在基于全基因组的蛋白谱系统进化树中,Yong-L2-223形成一个独立的分支(branch),与其他病毒间进化距离远。【结论】Yong-L2-223在有尾纲中代表一个新的未知的属。本研究首次以海洋蓝藻为指示藻从淡水中分离获得噬藻体,且该噬藻体序列新颖,拓宽了对噬藻体的认知,丰富了噬藻体库、噬藻体基因库,为噬藻体资源开发奠定了基础。

关键词：海洋聚球藻淡水噬藻体基因组分析

Promoting the optoelectronic and ferromagnetic properties of Cr_(2)S_(3)nanosheets via Se doping

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Science China(Physics,Mechanics & Astronomy) 2022年第7期65卷 138-146页

作者： Xinyun Zhou Chang liu lingting Song Hongmei Zhang Ziwei Huang Chenglin He Bailing li Xiaohui lin Zucheng Zhang Shun Shi Dingyi Shen Rong Song Jia li Xingqiang liu Xuming Zou Le Huang Lei liao Xidong Duan Bo li School of Physics and Electronics College of Semiconductors(College of Integrated Circuits)Hunan UniversityChangsha 410082China Hunan Key Laboratory of Two-Dimensional Materials and State Key Laboratory for Chemo/Biosensing and Chemometrics College of Chemistry and Chemical EngineeringHunan UniversityChangsha 410082China Key Laboratory of Nondestructive Testing(Ministry of Education) Nanchang Hangkong UniversityNanchang 330063China Key Laboratory for Micro-Nano Physics and Technology of Hunan Province College of Materials Science and EngineeringHunan UniversityChangsha 410082China School of Materials and Energy Guangdong University of TechnologyGuangzhou 510006China Shenzhen Research Institute of Hunan University Shenzhen 518063China Research Institute of Hunan University in Chongqing Chongqing 401120China

Doping can change the band structure of semiconductors,thereby affecting their electrical,optical,and magnetic *** this study,we describe the synthesis of two-dimensional(2D)Se-doped Cr_(2)S_(3)(Se-Cr_(2)S_(3))nanosheets using the chemical vapor deposition *** these semiconductor nanosheets,the Se doping concentration can be controlled by tuning the Se/S mass ratio in the *** the doping concentrations of 10.05%and 2.05%,the room temperature conductivity and mobility were increased by nearly 4 and 2 orders of magnitude,*** addition,the response time of an ultrathin Se-Cr_(2)S_(3)photodetector was 200 times shorter than that of an undoped Cr_(2)S_(3)nanosheet photodetector.4.07%-Se-Cr_(2)S_(3)nanosheets show ferrimagnetic behavior with a Curie temperature of~200 K,which is 80 K higher than that of undoped Cr_(2)S_(3)nanosheets.A density functional theory calculation indicated that the Se doping can induce the formation of intercalated Cr vacancies in SeCr_(2)S_(3)and enhance its metallic *** results demonstrated that Se-Cr_(2)S_(3)has significant potential in future electronic,optoelectronic,and spintronic devices.

关键词： two-dimensional materials Cr_(2)S_(3)nanosheets doping optoelectronics ferromagnetism

Synthesis of novel Pt/MO/GN composites and their electrocatalysis toward methanol oxidation

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Synthesis of novel Pt/MO/GN composites and their electrocata...

Synthesis of Pd@Pt/GNs composite and its superior electrocatalysis for methanol oxidation

中国化学会第九届全国无机化学学术会议

作者： lin Shen li zhongshui Ye lingting Huang Xiaomei Lei Fengling College of Chenistry and Chemical Engneering Fujian Normal University

Direct methanol fuel cells（DMFCs） have attracted extensive attention as green power sources for vehicles and portable electronics. An enormous amount of effort has been dedicated to investigate the structures and mechanisms of the catalyst system, which aim at providing catalysts with higher efficiency, lower cost, and longer durability. In this work, two-dimensional（2D） graphene nanosheets（GNs） were functionalized with soluble macromolecule and used as scaffold materials to load Pt nanoparticles with designed shapes and sizes to optimize efficient Pt utilization. Meanwhile, metallic oxo-compounds（MO）, such as polyoxometalate（POMs） or metallic oxide（Ti O2, Cu2 O, Zn O, Sn O2, etc.） have rich electrochemical properties and thermodynamic characteristics, which are introduced into Pt/graphene composites to achieve stronger synergistic interaction between different components and remarkably improve electrocatalytic performances toward methanol oxidation. Seven different type of composites were designed and synthesized successfully as follows: Pt/{PDDA-GNs/PSS-GNs}n, Pt/{PEI-GNs/PMo12}n, Pt/CS/PW12-GNs, Pt/GNs-CD, Pt/G4（CS）/GNs-H, Pt/Ti O2/GNs-M and Pt/Cu2O/GNs-H. The components, constructions and morphologies of as-synthesized composites were utilized to characterized by TEM, HAADF-STEM, SEM, AFM, EDX, XPS, XRD, FT-IR, UV-vis, TGA, ICP and Raman spectra. Cyclic voltammetry（CV）, chronoamperometry, COad stripping voltammetry, and electrochemical impedance spectroscopy（EIS） were used to study the electrocatalytic properties toward methanol oxidation. The investigation results show that the as-synthesized composites exhibit remarkably enhanced catalytic activities toward methanol oxidation and better CO tolerance compared with Pt/C catalyst（Johnson Matthey） and recently reported Pt graphene-based catalysts. It is worthy of noting that, under the light irradiation, the catalytic activity and stability of Pt/TiO 2/GNs-M and Pt/Cu2O/GNs-H composites drastically increases due t

关键词： Graphene Platinum metallic oxo-compounds electrocatalysis methanol oxidation

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Synthesis of Pd@Pt/GNs composite and its superior electrocat...