检索结果-南通市图书馆

3D printing in space:from mechanical structures to living tissues

在线全文

学校读者我要写书评

暂无评论

International Journal of Extreme Manufacturing 2024年第2期6卷 378-387页

作者： mao mao Zijie Meng xinxin huang Hui Zhu Lei Wang xiaoyong Tian Jiankang he Dichen Li Bingheng Lu State Key Laboratory for Manufacturing Systems Engineering Xi’an Jiaotong UniversityXi’an 710049People’s Republic of China National Medical Products Administration(NMPA)Key Laboratory for Research and Evaluation of Additive Manufacturing Medical Devices Xi’an Jiaotong UniversityXi’an 710049People’s Republic of China National Innovation Platform(Center)for Industry-Education Integration of Medical Technology Xi’an Jiaotong UniversityXi’an 710049People’s Republic of China Frontier institute of Science and Technology Xi’an Jiaotong UniversityXi’an 710049People’s Republic of China National Innovation institute of Additive Manufacturing Xi’an 710000People’s Republic of China

3D printing stands at the forefront of transforming space exploration,offering unprecedented on-demand and rapid manufacturing capabilities.It adeptly addresses challenges such as mass reduction,intricate component fabrication,and resource constraints.Despite the obstacles posed by microgravity and extreme environments,continual advancements underscore the pivotal role of 3D printing in aerospace science.Beyond its primary function of producing space structures,3D printing contributes significantly to progress in electronics,biomedicine,and resource optimization.This perspective delves into the technological advantages,environmental challenges,development status,and opportunities of 3D printing in space.Envisioning its crucial impact,we anticipate that 3D printing will unlock innovative solutions,reshape manufacturing practices,and foster self-sufficiency in future space endeavors.

关键词： 3D printing in space space manufacturing microgravity

Space advanced technology demonstration satellite

在线全文

学校读者我要写书评

暂无评论

Science china(Technological sciences) 2024年第1期67卷 240-258页

作者： ZHANG xiaoFeng CheN Wen ZHU xiaoCheng MENG Na he JunWang BI xingZi ZHANG Yonghe SHI Qi LI Fei LIU Rui FENG ZhengGong LIU Liu LI JinSong WU HaiChen XU Dongxiao LI TaiJie huang JiangJiang LIU Shuo LI TianTong YU xianSheng GAO Yang ZHOU heng BAN HanYu ZHANG YanLi ZHANG YueTing YANG YingQuan he Tao DUAN XuLiang CheN xin WANG YaMin SUN AnTai ZHANG Kuoxiang SUN Ying WANG YaoBin FAN ChengCheng xiONG ShaoLin LI xinQiao WEN xiangYang LING Zhixing SUN xiaoJin ZHANG Chen BAI xianYong WANG ZhanShan DENG YuanYong TIAN Hui YANG JianFeng XUE HongBo SANG Peng LIU JinGuo ZheNG HuiLong ZHU xiang he JianWu LI Hui XU Luxiang XU ShuYan CheN WenWu LIU ZhenDong WANG ZhaoLi mao xiangLong GAO Rong LI ZongXuan DING GuoPeng WANG xinYu DOU RunJiang WENG LuBin LUO Hao WANG YaPing LIANG xianFeng FANG ZiRuo Innovation academy for Microsatellites Chinese Academy of SciencesShanghai 201203China institute of High Energy physics Chinese Academy of SciencesBeijing 100049China National Astronomical Observatory of china Beijing 100101China Shanghai institute of Technical physics Chinese Academy of SciencesShanghai 200083China institute of Precision Optical Engineering School of Physics Science and EngineeringTongji UniversityShanghai 200092China School of Earth and Space sciences Peking UniversityBeijing 100871China xi’an institute of Optics and Precision Mechanics Chinese Academy of SciencesXi’an 710119China National Space Science Center Chinese Academy of SciencesBeijing 100190China Shenyang institute of Automation Chinese Academy of SciencesShenyang 110016China institute of Engineering Thermophysics Chinese Academy of SciencesBeijing 100190China institute of Mechanics Chinese Academy of SciencesBeijing 100190China Shanghai institute of Organic Chemistry Chinese Academy of SciencesShanghai 200032China Hangzhou institute for Advanced Study University of Chinese Academy of SciencesHangzhou 310024China Nanyang Technological University Singapore 569830Singapore Dalian institute of Chemical physics Chinese Academy of SciencesDalian 116023China Technical institute of physics and Chemistry Chinese Academy of SciencesBeijing 100049China Changchun institute of Optics Fine Mechanics and PhysicsChinese Academy of SciencesChangchun 130033China institute of Semiconductors Chinese Academy of SciencesBeijing 100083China institute of Automation Chinese Academy of SciencesBeijing 100190China School of Aeronautics and Astronautics Zhejiang UniversityHangzhou 310058China

The Space Advanced Technology demonstration satellite(SATech-01),a mission for low-cost space science and new technology experiments,organized by chinese academy of sciences(CAS),was successfully launched into a Sun-synchronous orbit at an altitude of~500 km on July 27,2022,from the Jiuquan Satellite Launch Centre.Serving as an experimental platform for space science exploration and the demonstration of advanced common technologies in orbit,SATech-01 is equipped with 16 experimental payloads,including the solar upper transition region imager(SUTRI),the lobster eye imager for astronomy(LEIA),the high energy burst searcher(heBS),and a High Precision Magnetic Field Measurement System based on a CPT Magnetometer(CPT).It also incorporates an imager with freeform optics,an integrated thermal imaging sensor,and a multi-functional integrated imager,etc.This paper provides an overview of SATech-01,including a technical description of the satellite and its scientific payloads,along with their on-orbit performance.

关键词： SATech-01 spacecraft design scientific instruments on-orbit performance

Characteristic of Near-surface Microstructure and Its Effects on the Torsion Performance of Cold Drawn Pearlitic Steel Wires for Bridge Cables

在线全文

学校读者我要写书评

暂无评论

Journal of wuhan University of Technology(Materials Science) 2022年第5期37卷 992-999页

作者：张帆 mao xinping 鲍思前 ZHAO Gang ZHAO Sixin DENG Zhaojun he Meng huang Fangyu QU xi The State Key Laboratory of Refractories and Metallurgy Wuhan University of Science and TechnologyWuhan430081China Baosteel Central Research institute Wuhan430080China Key Laboratory for Ferrous Metallurgy and Resources Utilization of Ministry of Education Wuhan University of Science and TechnologyWuhan430081China

The characteristic of near-surface microstructure and its effects on the torsion performance of cold-drawn pearlitic steel wires for bridge cables were investigated by focused ion beam-scanning electron microscope,transmission electron microscopy and differential scanning calorimetry.The samples with similar tensile strength before and after hot-dip galvanizing process are,respectively,characterized as delaminated and non-delaminated in torsion test which indicates that the tensile strength is independent of the toughness value(i e,reduction area and torsion ability).It is interesting to find that there exists submicron granular ferrite on near-surface of the wires,which can be attributed to dislocation rearrangement and sub-grains rotation during cold drawing and hot-dip galvanizing process.And their distribution can suggest homogeneousness of deformation degree to a certain extent:the closer to the surface of their distribution,the more homogeneous deformation of the wires.There is a close relationship between the thermal stability of the cementite layer and distribution of granular ferrite:differential scanning calorimetry(DSC)analysis shows that the sample is accompanied by submicron granular ferrite which is located closer to the surface has higher thermal stability under galvanizing temperature(450°C).A new mechanism of the torsion delamination of pearlitic steel wires is discussed in terms of the thermal stability of the cementite layer and distribution of granular ferrite.

关键词： cold-drawn pearlite steel wires torsion performance near-surface microstructure submicron granular ferrite

Microstructure Evolution and Its Effects on the Mechanical Behavior of Cold Drawn Pearlite Steel Wires for Bridge Cables

在线全文

学校读者我要写书评

暂无评论

Journal of wuhan University of Technology(Materials Science) 2022年第1期37卷 96-103页

作者：张帆 mao xinping 鲍思前 ZHAO Gang ZHAO Sixin DENG Zhaojun he Meng huang Fangyu QU xi The State Key Laboratory of Refractories and Metallurgy Wuhan University of Science and TechnologyWuhan 430081China Baosteel Central Research institute Wuhan 430080China Key Laboratory for Ferrous Metallurgy and Resources Utilization of Ministry of Education Wuhan University of Science and TechnologyWuhan 430081China

The microstructure evolution and its effects on the mechanical performance of 2000 MPa bridge cable steel wires were investigated by transmission electron microscope(TEM),electron backscatter diffraction(EBSD),X-ray diffractometer(XRD)and mechanical tests.Experimental results reveal that,with the increasing strain from 0 to 1.42,a fiber structure and afiber texture aligned with the wire axis are gradually developed accompanied by cementite decomposition and the formation of sub-grains;the tensile strength increases linearly from 1510 to 2025 MPa,and the reduction of the area is stable with a slight decline from 44%to 36%.After annealing at 450℃for different times,pronounced changes in the microstructure occur.Cementite lamella fragment into coarser globules corresponding to a remarkable spheroidization process,while ferrite domains recover and recrystallize,and this process is associated to modifications in the mechanical properties.Furthermore,based on the observations on dislocation lines crossing through cementite lamellae,a possible mechanism of cementite decomposition is discussed.

关键词： pearlitic steels cold drawing annealing microstructure mechanical properties

Nondestructive technique for identifying nuclides using neutron resonance transmission analysis at CSNS Back-n

在线全文

学校读者我要写书评

暂无评论

Nuclear Science and Techniques 2024年第1期35卷 178-187页

作者： Sheng-Da Tang Yong-Hao Chen Jing-Yu Tang Rui-Rui Fan Qiang Li Gong Li Dong Liu Zheng-Yao Jin xing-Zhu Cui Tian-xiang Chen Yi-Wei Yang Rong Liu Han Yi Yang Li Zhen Yang Qi An Hao-Fan Bai Jiang-Bo Bai Jie Bao Ping Cao Qi-Ping Chen Zhen Chen Zeng-Qi Cui An-Chuan Fan Chang-Qing Feng Fan-Zhen Feng Ke-Qing Gao Min-Hao Gu Chang-Cai Han Zi-Jie Han Guo-Zhu he Yong-Cheng he Yang Hong Yi-Wei Hu Han-xiong huang Wei-Hua Jia Hao-yu Jiang Wei Jiang Zhi-jie Jiang Ling Kang Bo Li Chao Li Jia-Wen Li xiao Li Jie Liu Shu-Bin Liu Guang-Yuan Luan Chang-Jun Ning Bin-Bin Qi Jie Ren Zhi-Zhou Ren xi-Chao Ruan Zhao-Hui Song Kang Sun Zhi-xin Tan Li-Jiao Wang Peng-Cheng Wang Zhao-Hui Wang Zhong-Wei Wen xiao-Guang Wu Xuan Wu Li-Kun xie Yong-Ji Yu Guo-Hui Zhang Lin-Hao Zhang Mo-Han Zhang Qi-Wei Zhang xian-Peng Zhang Yu-Liang Zhang Yue Zhang Zhi-Yong Zhang mao-Yuan Zhao Lu-Ping Zhou Zhi-Hao Zhou Ke-Jun Zhu Sino-French institute of Nuclear Engineering and Technology Sun Yat-sen UniversityZhuhai 519082China institute of High-Energy physics Chinese Academy of Sciences(CAS)Beijing 100049China Spallation Neutron Source Science Center Dongguan 523803China School of Nuclear Science and Technology University of Science and Technology of ChinaHefei 230026China State Key Laboratory of Particle Detection and Electronics University of Science and Technology of ChinaHefei 230026China State Key Laboratory of Particle Detection and Electronics Institute of High Energy PhysicsChinese Academy of SciencesBeijing 100049China USTC Archaeometry Laboratory University of Science and Technology of ChinaHefei 230026China institute of Nuclear physics and Chemistry China Academy of Engineering PhysicsMianyang 621900China Department of Modern physics University of Science and Technology of ChinaHefei 230026China State Key Laboratory of Nuclear physics and Technology School of PhysicsPeking UniversityBeijing 100871China Key Laboratory of Nuclear Data China Institute of Atomic EnergyBeijing 102413China Northwest institute of Nuclear Technology Xi’an 710024China University of chinese academy of sciences Beijing 100049China

Nondestructive and noninvasive neutron assays are essential applications of neutron techniques.Neutron resonance transmission analysis(NRTA)is a powerful nondestructive method for investigating the elemental composition of an object.The back-streaming neutron line(Back-n)is a newly built time-of-flight facility at the china Spallation Neutron Source(CSNS)that provides neutrons in the eV to 300 MeV range.A feasibility study of the NRTA method for nuclide identification was conducted at the CSNS Back-n via two test experiments.The results demonstrate that it is feasible to identify different elements and isotopes in samples using the NRTA method at Back-n.This study reveals its potential future applications.

关键词： CSNS White neutron beam NRTA Nuclide identification Nondestructive method

A draft sequence of the rice (Oryza sativa ssp. indica) genome

在线全文

学校读者我要写书评

暂无评论

chinese Science Bulletin 2001年第23期46卷 1937-1942页

作者： YU Jun, HU Songnian, WANG Jun,LI Songgang WONG Ka-Shu Gane, LIU Bin,DENG Yajun, DAI Li, ZHOU Yan,ZHANG xiuqing, CAO Mengliang, LIU Jing,SUN Jiandong , TANG Jiabin, CheN Yanjiong,huang xiaobing, LIN Wei, YE Chen, TONG Wei,CONG Lijuan, GENG Jianing, HAN Yujun, LI Lin,LI Wei, HU Guangqiang, huang xiangang,LI Wenjie, LI Jian, LIU Zhanwei, LI Long,LIU Jianping, Ql Qiuhui, LIU Jinsong, LI Li,WANG Xuegang, LU Hong, WU Tingling,ZHU Miao, Nl Peixiang, HAN Hua, DONG Wei,REN xiaoyu, FENG xiaoli, GUI Peng,LI xianran, WANG Hao, XU xin, ZHAI Wenxue,XU Zhao, ZHANG Jinsong, he Sijie,ZHANG Jianguo, XU Jichen, ZHANG Kunlin,ZheNG xianwu, DONG Jianhai, ZENG Wanyong,TAO Lin, CheN Xuewei, he Jun, LIU Daofeng,TIAN Wei, TIAN Chaoguang, xiA Hongai,LI Gang, GAO Hui, LI Ping, CheN Wei ,WANG Xudong, ZHANG Yong, HU Jianfei,WANG Jing, LIU Song, YANG Jian,ZHANG Guangyu, xiONG Yuqing, LI Zhijie,mao Long, ZHOU Chengshu, ZHU Zhen,CheN Runsheng, HAO Bailin,ZheNG Weimou, CheN Shouyi, QUO Wei,LI Guojie, LIU Siqi, huang Guyang,TAO Ming, WANG Jian, ZHU Lihuang,YUAN Longping& YANG HuanmingBeijing Genomics institute/Center of Genomics & Bioinformatics, chinese academy of sciences, Beijing 101300, china Hangzhou Genomics institute/institute of Bioinformatics of Zhejiang University/Key Laboratory of Bioinformatics of Zhejiang Province, Hangzhou 310007, china institute of Genetics, chinese academy of sciences, Beijing 100101, china National Hybrid Rice R & D Center, Changsha 410125, china Laboratory of Bioinformatics, institute of Biophysics, chinese academy of sciences, Beijing 100101, china College of Life sciences, Peking University, Beijing 100871, china institute of Theoretical physics, chinese academy of sciences, Beijing 1Q0080, china Digital china Ltd., Beijing 100080, china institute of Computing Technology, chinese academy of sciences, Beijing 100080, china Medical College, xi’an Jiaotong University, xi’an 710061, chinaThese authors contributed equally to this work.Corresponding author.Corresponden Beijing Genomics institute/Center of Genomics & Bioinformatics Chinese Academy of Sciences Beijing China Hangzhou Genomics institute/institute of Bioinformatics of Zhejiang University/Key Laboratory of Bioinformatics of Zhejiang Province Hangzhou China College of Life sciences Peking University Beijing China Medical College Xi’an Jiaotong University Xi’an China institute of Genetics Chinese Academy of Sciences Beijing China Laboratory of Bioinformatics Institute of Biophysics Chinese Academy of Sciences Beijing China National Hybrid Rice R & D Center Changsha China institute of Theoretical physics Chinese Academy of Sciences Beijing China Digital china Ltd. Beijing China institute of Computing Technology Chinese Academy of Sciences Beijing China

The sequence of the rice genome holds fundamental information for its biology, including physiology, genetics, development, and evolution, as well as information on many beneficial phenotypes of economic significance. Using a "whole genome shotgun" approach, we have pro-duced a draft rice genome sequence of Oryza sativa ssp. in-dica, the major crop rice subspecies in china and many other regions of Asia. The draft genome sequence is constructed from over 4.3 million successful sequencing traces with an accumulative total length of 2214.9 Mb. The initial assembly of the non-redundant sequences reached 409.76 Mb in length, based on 3.30 million successful sequencing traces with a total length of 1797.4 Mb from an indica variant cultivar 93-11, giving an estimated coverage of 95.29% of the rice genome with an average base accuracy of higher than 99%. The coverage of the draft sequence, the randomness of the sequence distribution, and the consistency of BIG-ASSEM-BLER, a custom-designed software package

关键词： rice genome draft sequences.

A novel protein domain is important for photosystem Ⅱ complex assembly and photoautotrophic growth in angiosperms

在线全文

学校读者我要写书评

暂无评论

Molecular Plant 2023年第2期16卷 374-392页

作者： Wei Li Jiangfan Guo Xue Han xiaowen Da Kai Wang Hongfei Zhao Shi-Tang huange Bosheng Li Hang he Ruirui Jiang Shichen Zhou Peng Yan Tao Chen Yi he Jiming Xu Yu Liu Yunrong Wu Huixia Shou Zhongchang Wu Chuanzao mao xiaorong Mo State Key Laboratory of Plant Environmental Resilience College of Life ScienceZhejang UniversityHangzhou 310058PR China College of Life Science Shaanxi Normal UniversityXi'anShaanxi Province 710062PR China School of Advanced Agricultural sciences and School of Life sciences State Key Laboratory of Protein and Plant Gene ResearchPeking UniversityBeijing 100871China Peking University institute of Advanced Agricultural sciences Shandong Laboratory of Advanced Agricultural Sciences at WeifangWeifangShandong 261000China College of Urban Construction Zhejiang Shuren UniversityHangzhou 310015PR China School of Life sciences Peking UniversityBeijing 100871PR China State Key Laboratory of Subtropical Silviculture Zhejiang A&F UniversityLin'anHangzhou 311300PR China

Photosystem Ⅱ(PSⅡ)is a multi-subunit protein complex of the photosynthetic electron transport chain that is vital to photosynthesis.Although the structure,composition,and function of PSⅡ have been extensively studied,its biogenesis mechanism remains less understood.Thylakoid rhodanese-like(TROL)provides an anchor for leaf-type ferredoxin:NADP^(+)oxidoreductase.here,we report the chacterizaton of a second type of TROL protein,TROL2,encoded by seed plant genomes whose function has not previously been reported.We show that TROL2 is a PSⅡ assembly cofactor with essential roles in the establishment of photoautotrophy.TROL2 contains a 45-amino-acid domain,termed the chlorotic lethal seedling(CLS)domain,that is both necessary and sufficient for TROL2 function in PSⅡ assembly and photoautotrophic growth.Phylogenetic analyses suggest that TROL2 may have arisen from ancestral TROL1 via gene duplication before the emergence of seed plants and acquired the CLS domain via evolution of the sequence encoding its N-terminal portion.We further reveal that TROL2(or CLS)forms an assembly cofactor complex with the intrinsic thylakoid membrane protein LOW PSⅡ ACCUMULATION2 and interacts with small PSⅡ subunits to facilitate PSⅡ complex assembly.Collectively,our study not only shows that TROL2(CLS)is essential for photoautotrophy in angiosperms but also reveals its mechanistic role in PSⅡ complex assembly,shedding light on the molecular and evolutionary mechanisms of photosynthetic complex assemblyin angiosperms.

关键词： PSⅡassembly TROL2 assembly factors angiosperms evolution

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

深圳市新生儿脑卒中多中心现况调查

中国当代儿科杂志 2024年第5期26卷 450-455页

作者：时莉秀冯晋兴韦艳芳路欣茹张雨茜杨林颖何胜男陈佩娟韩静陈诚涂惠英余章斌黄进洁曾淑娟陈晚铃刘颖郭燕平毛姣玉李晓东张谦慎谢治利黄梅英晏昆山应尔雅陈俊王艳荣刘亚萍宋波刘华艳肖晓冬唐红王宇娜蔡茵莎龙琦许汉强王会战孙倩韩芳张瑞彪杨传忠窦蕾时会菊王瑞蒋萍无深圳市儿童医院新生儿科广东深圳518034 深圳市宝安区妇幼保健院新生儿科广东深圳518101 深圳市龙岗区妇幼保健院/汕头大学医学院龙岗妇幼临床学院新生儿科广东深圳518172 深圳市人民医院/暨南大学第二临床医学院/南方科技大学第一附属医院新生儿科广东深圳518020 深圳市龙岗中心医院/广州中医药大学深圳临床医学院新生儿科广东深圳518116 北京大学深圳医院新生儿科广东深圳518036 华中科技大学协和深圳医院新生儿科广东深圳518052 香港大学深圳医院新生儿科广东深圳518053 深圳市龙岗区人民医院新生儿科广东深圳518172 深圳市南山区妇幼保健院新生儿科广东深圳518067 深圳市第三人民医院新生儿科广东深圳518112 深圳市龙华区中心医院新生儿科广东深圳518110 深圳市盐田区人民医院新生儿科广东深圳518081 深圳远东妇产医院新生儿科广东深圳518002 深圳市第二人民医院新生儿科广东深圳518025 陆丰市人民医院新生儿科广东陆丰516500 惠阳三和医院新生儿科广东惠州518200 惠州市第三人民医院新生儿科广东惠州516100 深圳市妇幼保健院新生儿科广东深圳518028 南方科技大学医院新生儿科广东深圳518055 深圳市罗湖区人民医院新生儿科广东深圳518005 深圳新生儿数据协作网

目的总结深圳市新生儿脑卒中发病率、临床特征及预后等情况,提高脑卒中新生儿的早期诊治能力。方法由深圳市儿童医院牵头,收集2020年1月—2022年12月深圳新生儿数据协作网组织21家单位收治的新生儿脑卒中36例,分析深圳市新生儿脑卒中发... 详细信息

目的总结深圳市新生儿脑卒中发病率、临床特征及预后等情况,提高脑卒中新生儿的早期诊治能力。方法由深圳市儿童医院牵头,收集2020年1月—2022年12月深圳新生儿数据协作网组织21家单位收治的新生儿脑卒中36例,分析深圳市新生儿脑卒中发病率、临床特征、治疗、预后等情况。结果深圳市21家医院2020、2021、2022年新生儿脑卒中的发病率分别为1/15137、1/6060、1/7704。缺血性脑卒中占75%(27/36),男性患儿占64%(23/36)。86%(31/36)的患儿在生后3d内起病,53%(19/36)以惊厥起病。颅脑影像学结果显示,22例(61%)大脑左侧发生梗死,13例(36%)基底节梗死;12例完成磁共振血管成像检查,9例(75%)累及大脑中动脉。29例患儿完成脑电图检查,21例(72%)出现尖波,10例(34%)出现电发作。不同医院对症支持治疗不同。12例(33%)完善新生儿行为神经测定评分,平均得分(32±4)分。共随访27例患儿12月龄左右的预后情况,44%(12/27)的患儿预后良好。结论新生儿脑卒中主要为缺血性脑卒中,多以惊厥为首发症状,多累及大脑中动脉,脑电图多出现尖波,神经发育评分较低,以对症支持治疗为主,部分患儿预后不良。

关键词：脑卒中多中心研究新生儿

Development of a simplified and inexpensive RNA depletion method for plasmid DNA purification using size selection magnetic beads(SSMBs)

在线全文

学校读者我要写书评

暂无评论

Genes & Diseases 2021年第3期8卷 298-306页

作者： xi Wang Ling Zhao xiaoxing Wu Huaxiu Luo Di Wu Meng Zhan Jing Zhang Mikhail Pakvasa William Wagstaff Fang he Yukun mao Yongtao Zhang Changchun Niu Meng Wu xia Zhao Hao Wang Linjuan huang Deyao Shi Qing Liu Na Ni Kai Fu Kelly Hynes Jason Strelzow Mostafa El Dafrawy Tong-Chuan he Hongbo Qi Zongyue Zeng Ministry of Education Key Laboratory of Diagnostic Medicine School of Laboratory and Diagnostic MedicineChongqing Medical UniversityChongqing400016PR China Molecular Oncology Laboratory Department of Orthopaedic Surgery and Rehabilitation MedicineThe University of Chicago Medical CenterChicagoIL60637USA Departments of Gastrointestinal Surgery Obstetrics and Gynecologyand NephrologyThe First Affiliated Hospital of Chongqing Medical UniversityChongqing400016PR China Department of Burn and Plastic Surgery West China Hospital of Sichuan UniversityChengduSichuan Province610041PR China Department of Orthopaedic Surgery The First Affiliated HospitalGuangzhou University of Chinese MedicineGuangzhouGuangdong Province510405PR China Departments of Orthopaedic Surgery and Neurosurgery The Affiliated Zhongnan Hospital of Wuhan UniversityWuhanHubei Province430072PR China Department of Orthopaedic Surgery The Affiliated Hospital of Qingdao UniversityQingdaoShandong Province266061PR China Department of Laboratory Diagnostic Medicine Chongqing General HospitalChongqing400021PR China institute of Boneand Joint Research The departments of Orthopaedic Surgery and Obstetrics and GynecologyThe First and Second Hospitals of Lanzhou UniversityLanzhouGansuProvince730030PR China Department of Orthopaedics Union HospitalTongji Medical CollegeHuazhong University of Science and TechnologyWuhanHubei Province430022PR China Department of Spine Surgery Second Xiangya HospitalCentral South UniversityChangshaHunan Province410011PR China

Plasmid DNA(pDNA)isolation from bacterial cells is one of the most common and critical steps in molecular cloning and biomedical research.Almost all pDNA purification in-volves disruption of bacteria,removal of membrane lipids,proteins and genomic DNA,purifi-cation of pDNA from bulk lysate,and concentration of pDNA for downstream applications.While many liquid-phase and solid-phase pDNA purification methods are used,the final pDNA preparations are usually contaminated with varied degrees of host RNA,which cannot be completely digested by RNase A.To develop a simple,cost-effective,and yet effective method for RNA depletion,we investigated whether commercially available size selection magnetic beads(SSMBs),such as Mag-Bind®TotalPure NGS Kit(or Mag-Bind),can completely deplete bacterial RNA in pDNA preparations.In this proof-of-principle study,we demonstrated that,compared with RNase A digestion and two commercial plasmid affinity purification kits,the SSMB method was highly efficient in depleting contaminating RNA from pDNA minipreps.Gene transfection and bacterial colony formation assays revealed that pDNA purified from SSMB method had superior quality and integrity to pDNA samples cleaned up by RNase A digestion and/or commercial plasmid purification kits.We further demonstrated that the SSMB method completely depleted contaminating RNA in large-scale pDNA samples.Furthermore,the Mag-bind-based SSMB method costs only 5-10%of most commercial plasmid purification kits on a per sample basis.Thus,the reported SSMB method can be a valuable and inexpensive tool for the removal of bacterial RNA for routine pDNA preparations.

关键词： DNA transfection DNA vaccination Gene delivery Plasmid DNA purification RNA depletion Size selection magnetic beads