检索结果-南通市图书馆

FTA-环介导等温扩增技术直接提取变异链球菌DNA的效果评价

在线全文

学校读者我要写书评

暂无评论

中国组织工程研究 2025年第5期29卷 1043-1049页

作者：王玥晖尚进杨晨符冬格曹灿张晓东王敬夫北部战区总医院口腔科辽宁省沈阳市110016 空军军医大学第三附属医院颌面外科陕西省西安市710004

背景:变异链球菌是龋病的重要病原菌,及时检测变异链球菌水平对龋病的早发现、早治疗有重要意义。目的:建立并评价FTA-环介导等温扩增(loop-mediated isothermal amplification,LAMP)技术直接提取变异链球菌DNA的应用效果。方法:①制备... 详细信息

背景:变异链球菌是龋病的重要病原菌,及时检测变异链球菌水平对龋病的早发现、早治疗有重要意义。目的:建立并评价FTA-环介导等温扩增(loop-mediated isothermal amplification,LAMP)技术直接提取变异链球菌DNA的应用效果。方法:①制备含有ATCC标准菌株变异链球菌的菌悬液,接种于脑心浸出液培养基,充分混匀后按10倍梯度稀释成7种浓度(4.2×10^(7),4.2×10^(6),4.2×10^(5),4.2×10^(4),4.2×10^(3),4.2×10^(2),4.2×10 CFU/mL),每个稀释级做2个平行对照,并增加无菌水作为空白对照;②分别采用FTA卡、常规煮沸法、试剂盒提取及裂解液提取4种方法直接提取菌株DNA,通过LAMP技术进行扩增,并进行特异性试验,比较4种提取方法的差异。结果与结论:①4种方法提取的DNA均满足LAMP扩增的要求;②特异性试验结果显示,只有变异链球菌才可特异扩增出靶基因;③裂解液提取法最低检测限为4.2×10^(3) CFU/mL,FTA卡提取法最低检测限为4.2×10^(4) CFU/mL,试剂盒提取法和常规煮沸法最低检测限分别为4.2×10^(6) CFU/mL和4.2×10^(7) CFU/mL;④4种提取方法其他方面的比较显示,试剂盒提取法的实验成本、步骤数和时间都是最高;其他3种方法步骤数一致,其中FTA卡所需仪器设备最少,常规煮沸法单次成本最低,裂解液提取法所需时间最少;FTA卡和裂解液提取法仅需少量菌即可提取成功,后者在时间方面优于FTA卡,但相较于FTA卡其单次成本高,所需设备多;⑤结果说明,该研究建立的FTA-LAMP技术具有操作简便、特异性强、灵敏度高、结果可视化等优势,有望为高效提取检测变异链球菌提供新途径。

关键词：变异链球菌环介导等温扩增 FTA卡 DNA 可视化

GPCR activation:protonation and membrane potential

在线全文

学校读者我要写书评

暂无评论

Protein & Cell 2013年第10期4卷 747-760页

作者： Xuejun C.Zhang Kening Sun Laixing Zhang Xuemei Li can cao National Laboratory of Macromolecules National Center for Protein Science-BeijingInstitute of BiophysicsChinese Academy of SciencesBeijing 100101China

GPCR proteins represent the largest family of signaling membrane proteins in eukaryotic *** importance to basic cell biology,human diseases,and pharma-ceutical interventions is well *** crystal structures of GPCR proteins have been reported in both active and inactive *** data indicate that agonist binding alone is not suffi cient to trigger the conformational change of GPCRs necessary for binding of downstream G-proteins,yet other essential factors re-main *** on analysis of available GPCR crystal structures,we identifi ed a potential conformational switch around the conserved Asp2.50,which consistently shows distinct conformations between inactive and active *** the structural information with the current literature,we propose an energy-coupling mechanism,in which the interaction between a charge change of the GPCR protein and the membrane potential of the living cell plays a key role for GPCR activation.

关键词： GPCR membrane potential protonation ac-tivation

Effects of 3d-transition metal doping on the electronic and magnetic properties of one-dimensional diamond nanothread

在线全文

学校读者我要写书评

暂无评论

Chinese Physics B 2020年第6期29卷 358-363页

作者： Zhenzhen Miao can cao Bei Zhang Haiming Duan Mengqiu Long Institute of Low-dimensional Quantum Materials and Devices School of Physics Science and TechnologyXinjiang UniversityUrumqi 830046China Hunan Key Laboratory of Super Micro-structure and Ultrafast Process School of Physics and ElectronicsCentral South UniversityChangsha 410083China

The diamond nanothread(DNT), a new one-dimensional(1 D) full carbon sp3 structure that has been successfully synthesized recently, has attracted widespread attention in the carbon community. By using the first-principles calculation method of density functional theory(DFT), we have studied the effects of 3 d transition metal(TM) atomic doping on the electronic and magnetic properties of DNT. The results show that the spin-polarized semiconductor characteristics are achieved by doping Sc, V, Cr, Mn, and Co atoms in the DNT system. The magnetic moment ranges from 1.00 μB to 3.00 μB and the band gap value is from 0.35 e V to 2.54 e V. The Fe-doped DNT system exhibits spin-metallic state with a magnetic moment of 2.58 μB, while the Ti and Ni-doped DNT systems are nonmagnetic semiconductors. These results indicate that the 3 d TM atoms doping can modulate the electronic and magnetic properties of 1 D-DNT effectively, and the TM-doped DNT systems have potential applications in the fields of electronics, optoelectronics, and spintronics.

关键词： diamond nanothread transition metal atom doping electronic and magnetic property

First-Principles Study on Electronic Structures and Optical Properties of Doped Ag Crystal

在线全文

学校读者我要写书评

暂无评论

Chinese Physics Letters 2012年第3期29卷 180-183页

作者： cao can CHEN Ling-Na JIA Shu-Ting ZHANG Dan XU Hui School of Physics Science and Technology Central South UniversityChangsha 410083 School of Computer Science and Technology University of South ChinaHengyang 421001

By using the first-principles calculation based on density functional theory,we investigate the electronic structures and optical properties of Cl-doped Ag *** results show that the electronic structure of Cl-doped Ag crystal depends on the doped concentration and the site of impurity ***,the calculated adsorption spectra of Cl-doped Ag crystal show isotropy or anisotropy coincide with the symmetry of Ag *** features are discussed to provide guidance to experimental efforts for Ag-based nanoeletronic devices.

关键词： defect crystal symmetry

微波消解-ICP-MS法测定中链甘油三酸酯中铜、铅、铬、镍、锡

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

质谱学报 2014年第4期35卷 341-346页

作者：曹璨辽宁省分析科学研究院辽宁沈阳110015

为满足国家药品安全的限量要求,采用微波消解法对中链甘油三酸酯（MCT）进行前处理,建立了电感耦合等离子体质谱（ICP-MS）测定MCT中痕量有害元素铜、铅、铬、镍、锡的方法,并对测定条件进行了优化.结果表明：各元素在0～30 μg/L范围... 详细信息

为满足国家药品安全的限量要求,采用微波消解法对中链甘油三酸酯（MCT）进行前处理,建立了电感耦合等离子体质谱（ICP-MS）测定MCT中痕量有害元素铜、铅、铬、镍、锡的方法,并对测定条件进行了优化.结果表明：各元素在0～30 μg/L范围内线性良好,相关系数r在0.999 4～0.999 9之间,方法检出限为0.013～0.057 μg/kg,相对标准偏差为1.2％～6.7％;对各元素进行3个不同浓度水平下的加标回收率实验,平均回收率为94.0％～110.0％.使用该方法测定国家标准物质鸡肉GBW10018中的痕量有害元素,测定结果与标准值无显著差异.

关键词：微波消解电感耦合等离子体质谱(ICP-MS) 中链甘油三酸酯(MCT) 有害元素

FWorks:An Integrated Digital Simulation Platform for FADEC Systems 36

在线全文

学校读者我要写书评

暂无评论

FWorks:An Integrated Digital Simulation Platform for FADEC S...

Proton transfer during class-A GPCR activation: do the CWxP motif and the membrane potential act in concert?

第36届中国控制会议

作者： can cao Jie Shen Maochun Luo Bing Yu Jiqiang Wang Zhongzhi Hu Jiangsu Province Key Laboratory of Aerospace Power System Nanjing University of Aeronautics and Astronautics

ISBN: (纸本)9781538629185

FWorks,an integrated digital simulation platform designed for collaborative research and development on Full Authority Digital Electronic Control（FADEC） systems for aircraft engines,is presented in this *** internet-based and an open architecture simulation platform,containing baselined numerical models for aircrafts,engines,FADEC systems and components,provides multiple users with flexibility,concurrently and remotely,to construct new or change existing models and control algorithms,to integrate the engine and FADEC system models,and to verify FADEC system interfaces,functionalities and performance.

关键词： digital simulation platform collaborative design FADEC aircraft engine

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

Biophysics Reports 2018年第3期4卷 115-122页

作者： Xuejun C.Zhang Ye Zhou can cao National Laboratory of Biomacromolecules CAS Center for Excellence in Biomacromolecules Institute of Biophysics Chinese Academy of Sciences University of Chinese Academy of Sciences

INTRODUCTION G-protein-coupled receptors(GPCRs) form the largest receptor superfamily of eukaryotic cells(Flock et al.2017). A typical GPCR protein contains seven transmembrane helices(TMs 1–7)(Palczewski et al. 2000).Upon activation, the GPCR opens a cavity on its cytoplasmic side, between TMs 5–6 and the remaining of the receptor,

关键词：

Production of ultrafine iron powder by low-temperature hydrogen reduction: properties change with temperature

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Journal of Iron and Steel Research International 2024年第11期31卷 2645-2654页

作者： Min Gan En-di Guo Hao-rui Li Yun-can cao Xiao-hui Fan Zhi-yun Ji Zeng-qing Sun School of Minerals Processing and Bioengineering Central South UniversityChangsha410083HunanChina

Ultrafine iron powder is widely used due to its excellent performance. Hydrogen reduction of fine-grained high-purity iron concentrate to prepare ultrafine iron powder has the advantages of low energy consumption, pollution-free, and low cost. The hydrogen reduction of high-purity iron concentrates, characterized by the maximum particle size of 6.43 μm when the cumulative distribution is 50% and the maximum particle size of 11.85 μm when the cumulative distribution is 90% while the total iron content of 72.10%, was performed. The hydrogen reduction could be completed at 425 ℃, and the purity of ultrafine iron powders was more than 99 wt.% in the range of 425–650 ℃. Subsequently, the effect of reduction temperature on various properties of ultrafine iron powder was investigated, including particle morphology, particle size, specific surface area, lattice parameters, bulk density, and reaction activity. It was found that the reaction activity of the iron powders prepared by hydrogen reduction was much higher than that of the products of carbonyl and liquid phase synthesis. Below 500 ℃, the reduced iron powders were nearly unbound, with a small particle size and a low bulk density. The particles had a porous surface, with a specific surface area as high as 11.31 m^(2) g^(−1). The crystallization of reduced iron powders was imperfect at this time, the amorphization degree was prominent, and the interior contained a high mechanical storage energy, which had shown high reaction reactivity. It was suitable for catalysts, metal fuels, and other functionalized applications.

关键词： High-purity iron concentrate Hydrogen reduction Ultrafine iron powder Mechanical activation High reaction activity

Differentially Expressed MicroRNAs Associated with Vein Graft Restenosis in Rats

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Cardiovascular Innovations and Applications 2020年第3期5卷 45-55页

作者： Shuwei Wan Hui cao Yubo Zhao Yaming Guo Chuang Li Nan Li can cao Zhaohui Hua Zhen Li Department of Endovascular Surgery The First Affi liated HospitalZhengzhou UniversityZhengzhou450000 HenanPeople’s Republic of China

Objective:Intimal hyperplasia is the main cause of restenosis of vein grafts after venous *** are considered to play a role in vein graft restenosis;however,the expression profi le of microRNAs in neointima has not been reported in *** wanted to investigate the differentially expressed microRNAs in the restenosis of vein grafts in ***:We established a rat model for vein transplantation to explore the pathogenic roles of microRNAs during intimal *** and eosin staining was used to confi rm intimal hyperplasia in the vein *** in microRNA expression in the vein grafts were detected 3 and 14 days after surgery by sequencing,reverse transcription–quantitative polymerase chain reaction,and bioinformatics analyses for functional ***:We detected 711 newly predicted microRNAs among all the *** these comparisons,437 differentially expressed microRNAs were detected in the postoperative day 3 group versus the control group,265 were detected in the postoperative day 14 group versus the control group,and 158 were detected in the postoperative day 14 group versus the postoperative day 3 *** analysis revealed signifi cant enrichment of target genes that mediate Wnt,mitogen-activated protein kinase,vascular smooth muscle contraction,and regulation of actin cytoskeleton ***:Our results provide insight into the pathogenesis of restenosis and will help develop novel targets in the prevention and treatment of vein graft restenosis.

关键词： vein graft intimal hyperplasia restenosis microRNA