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Isolation and Structure Elucidation of Autolytimycin, A New Compound Produced by Streptomyces Autolyticus JX-47

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Chinese Chemical Letters 2001年第10期12卷 903-906页

作者： Li, MG Wu, sh Zhao, LX Zhang, q.Li, WJ Cui, XL Xu, LH Wu, DG Jiang, CL yunnan Univ Yunnan Inst Microbiol Minist Educ PR China Key Lab Microbial Resources Kunming 650091 Peoples R China

Autolytimycin 1 was isolated from the culture filtrate of Streptomyces autolyticus JX-47, together with two known compounds, lebstatin 2 and 17-O-demethyl-geldanamycin 3. These compounds showed the activities of anti-... 详细信息

关键词： Streptomyces autolyticus autolytimycin lebstatin 17-O-demethyl-geldanamycin

Strengthening and deformation mechanism of high-strength CrMnFeCoNi high entropy alloy prepared by powder metallurgy

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Journal of Materials Science & Technology 2023年第1期132卷 119-131页

作者： y.Xing C.J.Li y.K.Mu y.D.Jia K.K.Song J.Tan G.Wang Z.q.Zhang J.H.yi J.Eckert Faculty of Materials Science and Engineering Kunming University of Science and TechnologyKunming 650093China Laboratory for Microstructures Institute of MaterialsShanghai UniversityShanghai 200444China School of Mechanical Electrical&Information EngineeringShandong UniversityWeihai 264209China College of Materials Science and Engineering Chongqing UniversityChongqing 400044China Erich Schmid Institute of Materials Science Austrian Academy of SciencesJahnstraße 12Leoben A-8700Austria Department of Materials Science Chair of Materials PhysicsMontanuniversität LeobenJahnstraße 12Leoben A-8700Austria Adjunct with National University of Science and Technology«MISiS» Leninsky Prosp.4Moscow 119049Russia

Multiphase CrMnFeCoNi high-entropy alloys(HEAs)were prepared by a powder metallurgy process com-bining mechanical alloying(MA)and vacuum hot-pressing sintering(HPS).The single-phase face-centered cubic(FCC)HEA powder prepared by MA was sintered into a bulk HEA specimen containing FCC phase matrix along with precipitated M 23 C 6 phase and nanoscaleσphase *** the sintering temper-ature was 1223 K,the ultimate strength reaches 1300±11.6 MPa,and the elongation exceeds 4%±0.6%.Microstructural characterization reveals that the formation of nanoscale particles and deformation twins play critical roles in improving the strain hardening(sh)*** the MA time promoted the formation of the precipitated phase and enhanced the sh ability by increasing the number of precip-itated *** sh capacity increases significantly with increasing sintering temperature,which is attributed to a significant enhancement in the twinning capacity due to grain growth and the reduced number ofσphase *** systematic studies,the planar glide of dislocations was found to be the main mode of deformation,while deformation twinning appeared as an auxiliary deformation mode when the twinning stress was *** the formation of precipitates leads to grain bound-ary and precipitation strengthening effects,crack initiation is more prominent owing to increased grain boundary brittleness around the precipitated M 23 C 6 *** prominence of crack initiation is a contra-diction that must be reconciled with regard to precipitation *** work serves as a useful reference for the preparation of high-strength HEA parts by powder metallurgy.

关键词： High entropy alloy Powder processing Grain reﬁnement Precipitation strengthening Deformation twinning

PROGRESS OF SyNTHETIC APERTURE SONAR IN CHINA

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PROGRESS OF SYNTHETIC APERTURE SONAR IN CHINA

Crystal structure of q.56A trichosanthin

2002中国—日本声学学术会议

作者： J. Tang Ch. Zhang sh. Li B. Sun J. Liu J. Xu y. Huang T. Lin sh. Xue L. Li T. Cui H. Huang y. Li q. Li Institute of Acoustics Chinese Academy of Science 17 Zhongguancun St. Beijing PRC

The Project of synthetic aperture sonar in China started in 1997. Up to now, we have built a prototype of synthetic aperture sonar for lake trial. It is of multi elements, so it can work in high speed

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来源： cnki会议评论

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Chinese Science Bulletin 1997年第16期42卷 1366-1369页

作者： Dong, yC Zhu, yR Cheng, sh Li, JH shaw, PC Chinese Acad Sci Inst Biophys Beijing 100101 Peoples R China Chinese Univ Hong Kong Dept Biochem Hong Kong Hong Kong Peoples R China

RIBOSOME inactivating proteins (RIPs) are a group of toxin with RNA N-glycosidase. It

关键词： mutant crystal structure trichosanthin.

The Effect of Injected Air Bubble Size on the Thermal Performance of a Vertical shell and Helical Coiled Tube Heat Exchanger

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Energy Engineering 2021年第6期118卷 1595-1609页

作者： Saif S.Hasan Ali sh.Baq.r Hameed B.Mahood Engineering Technical College Al-Furat Al-Awsat Technical UniversityAl-Najaf31001Iraq Department of Chemical and Process Engineering Faculty of Engineering and Physical SciencesUniversity of SurreyGuildfordGU27XHUK

In the present study,the effect of injecting air bubble size on the thermal performance of a vertical counter-current shell and coiled tube heat exchanger is experimentally *** experiments were accomplished in a cylindrical shape heat exchanger with a 50 cm height and 15 cm outer *** coil with 3.939 m eq.ivalent length and 0.6 cm outer diameter was used to carry the hot fluid(water).Four different cold fluid(shell side)flow rates(q.(s)=2;4;6 and 8 LPM)Þunder laminar flow conditions(316≤Re≤1223),constant hot(coil side)flow rate fluid rates(q.(h)=1 LPM),four different injected air flow rates(q.(a)=0:5;1;1:5 and 2 LPM),invariant temperature difference(ΔT=20°C),and constant bubble’s number(1400)were *** demonstrate the effect of bubble size,a sparger with orifice diameters of 0.1,0.8,and 1.5 mm was manufactured and used in the *** overall heat transfer coefficient(U),NTU,effectiveness,and pressure loss were *** experimental results clearly.sh.wed that the heat exchanger’s thermal efficiency significantly improved with increasing the shell side flow rate and the injected air flow *** maximum improvement in U,NTU,and effectiveness was 153%,153%,and 68%,*** thermal performance of the heat exchanger was shown to be improved with increasing the bubble *** the latter finding agrees with recent CFD published results,more studies need to be confirmed.

关键词： Sparger smooth helical coil vertical shell heat exchanger injection bubbles

‘C-type’ closed state and gating mechanisms of K2P channels revealed by conformational changes of the TREK-1 channel

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Journal of Molecular Cell Biology 2022年第1期14卷 47-55页

作者： q.ansen Zhang Jie Fu shaoying Zhang Peipei Guo shĳie Liu Juwen shen Jiangtao Guo Huaiyu yang shanghai Key Laboratory of Regulatory Biology Institute of Biomedical SciencesSchool of Life SciencesEast China Normal UniversityShanghai 200241China Department of Biophysics and Department of Pathology of Sir Run Run shaw Hospital Zhejiang University School of MedicineHangzhou 310058China

Two-pore domain potassium (K2P) channels gate primarily within the selectivity filter, termed ‘C-type’ gating. Due to the lack of structural insights into the nonconductive (closed) state, ‘C-type’ gating mechanisms remain elusive. Here, molecular dynamics (MD) simulations on TREK-1, a K2P channel, revealed that M4 helix movements induce filter closing in a novel ‘deeper-down’ structure that represents a ‘C-type’ closed state. The ‘down’ structure does not represent the closed state as previously proposed and instead acts as an intermediate state in gating. The study identified the allosteric ‘seesaw’ mechanism of M4 helix movements in modulating filter closing. Finally, guided by this recognition of K2P gating mechanisms, MD simulations revealed that gain-of-function mutations and small-molecule activators activate TREK-1 by perturbing state transitions from open to closed states. Together, we reveal a ‘C-type’ closed state and provide mechanical insights into gating procedures and allosteric regulations for K2P channels.

关键词： K2P state selectivity filter C-type gating

An authentication and plausibility model for big data analytic under LOS and NLOS conditions in 5G-VANET

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Science China(Information Sciences) 2020年第12期63卷 67-83页

作者： S.A.SOLEyMANI M.H.ANISI A.Hanan ABDULLAH M.Asri NGADI sh.GOUDARZI M.Khurram KHAN M.Nazri KAMA School of Computing Faculty of Engineering Universiti Teknologi Malaysia (UTM) School of Computer Science and Electronic Engineering University of Essex Centre of Artificial Intelligence National University of Malaysia (UKM) Center of Excellence in Information Assurance (CoEIA) King Saud University Advanced Informatics School Menara Razak Universiti Teknologi Malaysia (UTM)

The exchange of correct and reliable data among legitimate nodes is one of the most important challenges in vehicular ad hoc networks(VANETs). Malicious nodes and obstacles, by generating inaccurate information, have a negative impact on the security of 5G-VANET. The big data generated in the vehicular network is also an issue in the security of VANET. To this end, a security model based on authentication and plausibility is proposed to improve the safety of network named ‘AFPM’. In the first layer, an authentication mechanism using edge nodes along with 5G is proposed to deal with the illegitimate nodes who enter the network and broadcast wrong information. In the authentication mechanism, because of the growth of the connected vehicles to the edge nodes that lead to generating big data and hence the inappropriateness of the traditional data structures, cuckoo filter, as a space-efficient probabilistic data structure, is used. In the second layer, a plausibility model by performing fuzzy logic is presented to cope with inaccurate information. The plausibility model is based on detection of inconsistent data involved in the event message. The plausibility model not only tackles with inaccurate, incomplete, and inaccuracy data but also deals with misbehaviour nodes under both line-of-sight(LOS) and non-line-of-sight(NLOS) conditions. All obtained results are validated through well-known evaluation measures such as F-measure and communication overhead. The results presented in this paper demonstrate that the proposed security model possesses a better performance in comparison with the existing studies.

关键词： authentication plausibility fuzzy logic cuckoo filter 5G-VANET big data

缺血后处理对大鼠缺血再灌注心肌细胞凋亡的影响

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中国组织工程研究与临床康复 2007年第8期11卷 1450-1452页

作者：刘胜辉杨新春范谦首都医科大学附属朝阳医院心脏中心北京市100020

目的:观察缺血后处理对大鼠缺血再灌注心肌细胞凋亡的影响。方法:实验于2006-02/05在首都医科大学附属朝阳医院心脏中心实验室完成。选择健康SD大鼠48只,随机数字表法分为3组:假手术组、缺血再灌注组和缺血后处理组,每组16只。制备大鼠... 详细信息

目的:观察缺血后处理对大鼠缺血再灌注心肌细胞凋亡的影响。方法:实验于2006-02/05在首都医科大学附属朝阳医院心脏中心实验室完成。选择健康SD大鼠48只,随机数字表法分为3组:假手术组、缺血再灌注组和缺血后处理组,每组16只。制备大鼠心肌缺血再灌注模型。缺血再灌注组,收紧结扎线缺血40min,放松结扎线再灌注240min;缺血后处理组,缺血40min后,再灌注10s,缺血10s,连续3个循环,然后再灌注239min;假手术组,开胸后穿线做套环,但不收紧结扎线。采用TUNEL技术检测心肌细胞凋亡率,同时测定血清肌酸激酶活性和心肌梗死范围。结果:纳入动物48只,均进入结果分析。①血清中肌酸激酶活性的测定:再灌注结束后缺血后处理组和缺血再灌注组肌酸激酶活性明显高于假手术组[分别为(13.54±1.50),(20.72±1.58),(2.90±0.28)μkat/L,P<0.01],缺血后处理组明显低于缺血再灌注组(P<0.01)。②心肌梗死范围:再灌注结束后缺血后处理组和缺血再灌注组心肌缺血区与左室面积比值无明显差异,缺血后处理组心肌坏死区与缺血区比值显著低于缺血再灌注组(分别为26.1±6.7,40.2±7.2,P<0.01)。③心肌凋亡细胞计数:再灌注结束后假手术组未见明显细胞凋亡(<5%),缺血后处理组心肌细胞凋亡率明显低于缺血再灌注组[分别为(12.5±2.9)%,(21.3±3.8)%,P<0.01]。结论:缺血后处理可减轻缺血再灌注损伤、其机制可能与减少心肌细胞凋亡有关。

关键词：心肌缺血再灌注损伤细胞凋亡

脐血间充质干细胞:骨组织工程学的理想种子细胞?

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中国组织工程研究与临床康复 2007年第7期11卷 1329-1332页

作者：王琪苟三怀陈华江解放军第二军医大学附属长征医院骨科上海市200003

目的:探讨脐血间充质干细胞作为骨组织工程学研究的种子细胞的可行性和前景。资料来源:应用计算机检索Medline 1980-01/2005-12和Embase 1980-01/2005-12期间的有关的文献,检索词“umbilical cord blood,mesenchymal stem cell,bone tissue engineering”,并限定文章语言种类为English。同时计算机检索CBM、CBMdisc数据库1990-01/2004-04脐血间充质干细胞和组织工程学的相关文献,限定文章语言种类为中文,检索词“脐血/脐带血、间充质干细胞、骨组织工程学”。资料选择:选取试验包括脐血间充质干细胞的培养及鉴定和骨组织工程学发展的相关文献。纳入标准:①脐血间充质干细胞培养及鉴定相关的基础研究。②骨组织工程学进展相关的文献。排除标准:重复研究。资料提炼:共检索到47篇关于脐血间充质干细胞与骨组织工程学的实验或文献综述,30个实验符合纳入标准。排除的17篇为因重复的研究。资料综合:在特定条件培养基作用下,脐血间充质干细胞不仅可以分化为成骨、成软骨、成脂肪各种类型的细胞,而且可以向神经细胞、肝细胞及骨骼肌细胞等方向转化。脐血间充质干细胞具有易于取材、多向分化潜能、遗传背景稳定、植入体内安全、高增殖的特性,符合骨组织工程学研究种子细胞的要求。结论:脐血间充质干细胞凭借其独特的优点,有望成为未来骨组织工程学的理想种子细胞。

关键词：脐血间充质干细胞骨组织工程种子细胞.