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The synthesis of fluorescent nanoclusters based on the etching reaction

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Nano Research 2024年第5期17卷 4631-4638页

作者： Hongbin lin Yitao Cao Qiaofeng Yao Tiankai Chen Huiting Shan jianping Xie Joint School of National University of Singapore and Tianjin University International Campus of Tianjin UniversityFuzhou 350207China Department of Chemical and Biomolecular Engineering National University of SingaporeSingapore 117585Singapore National and Local Joint Engineering Research Center of MPTES in High Energy and Safety LIBs Engineering Research Center of MTEES(Ministry of Education)and Key Laboratory of ETESPG(GHEI)South China Normal UniversityGuangzhou 510006China Tianjin Key Laboratory of Molecular Optoelectronic Sciences Key Laboratory of Integrated Organic CircuitsMinistry of EducationDepartment of ChemistrySchool of ScienceTianjin UniversityTianjin 300072China

Thiolate-protected atomically precise nanoclusters(NCs)demonstrate a series of unique luminescent characteristics attributed to their various peculiar electronic ***,fluorescent NCs present extraordinary practical values in biosensing and bioimaging research ***,restricted by the types of fluorescent NCs,there are great difficulties in promoting the development of NCs in fluorescent research *** a result,it is of significant necessity for researchers to develop new synthetic pathways to produce high-quality fluorescent *** to the analysis about the structural characteristics of fluorescent NCs,some general features like longer motif and higher ligand-to-metal ratio can be found,consistent to some presented regularities in etching ***,in this work,we used Au_(25)(MHA)_(18)(MHA=6-mercaptohexanoic acid)as a model nanocluster and utilized the etching reaction to systematically explore etching products and their corresponding luminescent ***,we also identified three main reaction processes in the entire etching reaction process,which can generate new metal nanocluster species with various fluorescent ***,the etching reaction will provide a good platform to produce new luminescent metal NC species.

关键词： etching reaction metal nanoclusters fluorescent properties fluorescent conversion

Expression of a New hemA Gene from Agrobacterium radiobacter in Escherichia coli for 5-Aminolevulinate Production

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Chinese Journal of Chemical Engineering 2005年第4期13卷 522-528页

作者： LIU Xiaoxia（刘晓侠） lin jianping（林建平） QIN Gang（秦钢） CEN Peilin（岑沛霖） Institute of Bioengineering College of Materials Science and Chemical Engineering Zhejiang University Hangzhou 310027 China

A new hemA gene encoding 5-aminolevulinate (ALA) synthase was cloned from Agrobacterium ra- diobacter zju-0121. The ALA synthase catalyzes the pyridoxal phosphate-dependent condensation of succinyl coen- zyme A (succinyl-CoA) and glycine to produce ALA. Four plasmids carrying the A, radiobacter hemA gene were transformed into different E. coli strains. The effects of both genetic and physiological factors on the expression of ALA synthase and ALA production were studied. The results indicated that the final intracellular activity of ALA synthase and the production of ALA in different expression systems varied largely. Among them, the recombinant E. coli BL21 (DE3) harboring the expression plasmid pET28-A. R-hemA was the most suitable one. The effects of isopropyl-β-D-thiogalactopyranoside (IPTG) addition time, IPTG concentration, culture temperature and the initial concentration of precursors and glucose on the ALA production were also evaluated. The expressed ALA synthase accounted for about 23.7% of the intracellular soluble protein. The highest specific activity of ALA syn- thase was 13.8nmol·min-1·mg-1 of intracellular soluble protein. In the batch culture of the recombinant E. coli, the extracellular ALA concentration reached 0.9 g·L-1.

关键词： 5-aminolevulinate (ALA) ALA synthase metabolic engineering

Microstructure evolution and phase transformation of the mushy zone in a quenchedβ-solidifying TiAl alloy

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Journal of Materials Science & Technology 2024年第2期169卷 28-41页

作者： Fuqiang Zhang Xianfei Ding Leming Xu Xin Feng Hai Nan jianping He Yongfeng Liang Junpin lin State Key Laboratory for Advanced Metals and Materials University of Science and Technology BeijingBeijing 100083China Cast Titanium Alloy R&D Center Beijing Institute of Aeronautical MaterialsBeijing 100095China

This study investigates the phase constitutions and transformations that occur in the mushy zone and in the adjacent phase fields of a directionally solidified Ti-44Al-8Nb-1Cr alloy via quenching *** results indicate that the mushy zone consists of unmeltedβdendrites and interdendritic liquid,whose formation can be attributed to the difference in melting point aroused by local heterogeneity in ***βdendrite is composed of numerous subgrains with various *** quenching,theβdendrite transforms into Widmanstättenαvia a precipitation reaction,owing to the decreasing cooling rate caused by heat transfer from the surrounding ***,after quenching,the interdendritic liquid is transformed intoγ*** the singleβphase field and the lower part of the mushy zone,a massive transformation ofβtoγ***,in theβ+αphase field,bothβandαphases are retained to ambient *** the heating process,the transformation ofα→βgives rise to the formation ofβvariants,which affects the orientation ofβdendrites in the mushy *** growth kinematics of theα→βtransformation was elucidated,revealing the preferential growth directions of111and112forβ***,this study presents an illustration of the formation process of the mushy zone and the microstructural evolution during the heating and quenching process.

关键词： Titanium aluminides Mushy zone Quenching Electron backscattering diffraction Phase transformation

Molecular mechanism of SCARB2-mediatec attachment and uncoating of EV71

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Protein & Cell 2014年第9期5卷 692-703页

作者： Minghao Dang Xiangxi Wang Quan Wang Yaxin Wang jianping lin Yuna Sun Xuemei Li Liguo Zhang Zhiyong Lou Junzhi Wang Zihe Rao National Laboratory of Macromolecules Institute of Biophysics Chinese Academy of Science Beijing 100101 China Laboratory of Structural Biology School of Medicine Tsinghua University Beijing 100084 China School of Life Sciences School of Pharmacy Nankai University Tianjin 300071 China National Institutes for Food and Drug Control Beijing 100050 China

Unlike the well-established picture for the entry of enveloped viruses, the mechanism of cellular entry of non-enveloped eukaryotic viruses remains largely mysterious. Picornaviruses are representative models for such viruses, and initiate this entry process by their functional receptors. Here we present the structural and functional studies of SCARB2, a functional receptor of the important human enterovirus 71 （EV71）. SCARB2 is responsible for attachment as well as uncoating of EV71. Differences in the structures of SCARB2 under neutral and acidic conditions reveal that SCARB2 undergoes a pivotal pH-dependent conformational change which opens a lipid-transfer tunnel to mediate the expulsion of a hydrophobic pocket factor from the virion, a pre-requisite for uncoating. We have also identified the key residues essential for attachment to SCARB2, identifying the canyon region of EV71 as mediating the receptor interaction. Together these results provide a clear understanding of cellular attachment and initiation of uncoating for enteroviruses.

关键词： viral entry uncoating picornavirusesreceptor binding SCARB2 EV71 lipid transfer tunnel

Dual-curvilinear beam enabled tunable manipulation of high-and low-refractive-index particles

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Photonics Research 2024年第7期12卷 1427-1436页

作者： ZHENG YUAN CHENCHEN ZHANG YUAN GAO WENXIANG YAN XIAN LONG ZHI-CHENG REN XI-lin WANG jianping DING HUI-TIAN WANG National Laboratory of Solid State Microstructures and School of Physics Nanjing UniversityNanjing 210093China Collaborative Innovation Center of Advanced Microstructures Nanjing 210093China Collaborative Innovation Center of Solid-State Lighting and Energy-Saving Electronics Nanjing 210093China

We present an innovative approach for the simultaneous agile manipulation of high-refractive-index(HRI) and low-refractive-index(LRI) particles. Our method involves introducing a dual-curvilinear optical vortex beam(DC-OVB) generated by superimposing a pair of curved beams: HRI and LRI particles are controlled by the bright curve and the dark channel between the two curves, respectively. The proposed DC-OVB provides customizable motion paths and velocities for both LRI and HRI particles. Each curve of the DC-OVB can support a distinct orbital flow density(OFD), enabling the application of torques to HRI and LRI particles, guiding them to orbit along specified trajectories and prompting them to execute various curvilinear motions simultaneously,including curvilinear movement, revolution, and rotation.

关键词： tunable refractive beam

The underappreciated role of fugitive VOCs in ozone formation and health risk assessment emitted from seven typical industries in China

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Journal of Environmental Sciences 2024年第2期136卷 647-657页

作者： Zhiling Liang Yunjiang Yu Bingbing Sun Qian Yao Xihua lin Yongsheng Wang jianping Zhang Yingzi Li Xuefeng Wang Zhengzheng Tang Shexia Ma College of Environmental and Chemical Engineering Shanghai University of Electric PowerShanghai 200090China State Environmental Protection Key Laboratory of Environmental Protection Health Risk Assessment South China Institute of Environmental SciencesMinistry of Ecology and EnvironmentGuangzhou 510535China Henan Jiyuan Ecological Environment Testing Center Jiyuan 454650China Ecological Environment Bureau of Jiyuan Production City Integration Demonstration Zone Jiyuan 454650China

Fugitive emission from industrial sources may result in ozone formation and health risk,while the exact contribution of this source remains incompletely *** this study,emission characteristics,ozone formation potential(OFP)and health risk of fugitive VOCs in7 representative industries were *** material industry was the dominant contributor to VOCs of fugitive emission in comparison with other *** OFP of VOCs from fugitive emission was in the range of 1.45×10^(3)-3.98×10^(5)μg/m^(3),with a higher value than that of organized emission in seven industries except for the coking industry and the chemical material industry,suggesting that fugitive VOCs should be taken into account while developing control ***,m,p-xylene,n-nonane,ethylene,vinyl chloridethe and other high OFP-contributing species were the major reactive species that should be *** risk assessment investigated non-cancer and cancer risks of fugitive VOCs in 7 industries were all above safe level(HR>1 and LCR>1×10^(-4)),posing remarkable health threats to human *** were the main contributor to non-cancer risk,while halohydrocarbons and aromatics contributed most to cancer risks,posing remarkable health threat on human *** findings highlighted the contribution of fugitive VOCs on ozone formation and health risk was underestimated,indicating which should be considered in emission control strategies of industrial sources.

关键词： Industrial sources Volatile organic compounds Fugitive emission Ozone formation potential Health risk assessment

Factors That Affect the Computational Prediction of Hot Spots in Protein-Protein Complexes

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Computational Molecular Bioscience 2012年第1期2卷 23-34页

作者： jianping lin Pi Liu Hua-Zheng Yang Nagarajan Vaidehi College of Pharmacy Nankai University Tianjin China Department of Immunology Beckman Research Institute of the City of Hope Duarte USA State Key Laboratory of Elemento-Organic Chemistry Elemento-Organic Chemistry Institute Nankai University Tianjin China

Protein-protein complexes play an important role in the physiology and the pathology of cellular functions, and therefore are attractive therapeutic targets. A small subset of residues known as “hot spots”, accounts for most of the protein-protein binding free energy. Computational methods play a critical role in identifying the hotspots on the proteinprotein interface. In this paper, we use a computational alanine scanning method with all-atom force fields for predicting hotspots for 313 mutations in 16 protein complexes of known structures. We studied the effect of force fields, solvation models, and conformational sampling on the hotspot predictions. We compared the calculated change in the protein-protein interaction energies upon mutation of the residues in and near the protein-protein interface, to the experimental change in free energies. The AMBER force field (FF) predicted 86% of the hotspots among the three commonly used FF for proteins, namely, AMBER FF, Charmm27 FF, and OPLS-2005 FF. However, AMBER FF also showed a high rate of false positives, while the Charmm27 FF yielded 74% correct predictions of the hotspot residues with low false positives. Van der Waals and hydrogen bonding energy show the largest energy contribution with a high rate of prediction accuracy, while the desolvation energy was found to contribute little to improve the hot spot prediction. Using a conformational ensemble including limited backbone movement instead of one static structure leads to better predicttion of hotpsots.

关键词： Hotspot Prediction Computational Mutagenesis Concoord Ensemble Protein-Protein Complexes

Effect of Welding Parameters on Stress Distribution of Weld-Bonded Joints

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Effect of Welding Parameters on Stress Distribution of Weld-...

A New Species of the Genus Liurana(Anura:Ceratobatrachidae)from Medog,China

The 2011 International Conference on Chemical, Mechanical and Materials Engineering(CMME2011)

作者： Zhang Baowen lin jianping Lu Zhiguo College of Mechanical Engineering Tongji University

In the weld-through technique of weld-bonding process, adhesive usually suffers extremely high temperature, causing damage to adhesive and consequently the joint strength. The present work studied the effect of welding parameters on the stress distribution of weld-bonded joints under tensile loading. The adhesive properties at elevated temperatures were first presented based on the experiments. Then a finite element model was developed to predict the temperature distribution of weld-bonded joint in the welding process. Effect of welding parameters on the dimensions of weld nugget and adhesive failure zone was obtained. At last, the stress distribution of weld-bonded joint under tensile loading was studied through finite element method. It has been found that both the stress near the adhesive failure zone and the maximum stress of weld nugget decrease when the welding current increases.

关键词： Weld-bonded,stress distribution,failure zone

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Asian Herpetological Research 2024年第3期15卷 131-139页

作者： Haoqi YU Yiheng lin Yuxi WANG Puyang ZHENG Shengchao SHI Bin WANG jianping JIANG Zhaobin SONG Feng XIE Chengdu Institute of Biology Chinese Academy of SciencesChengdu 610213Sichuan China College of Life Sciences Sichuan UniversityChengdu 610065SichuanChina University of Chinese Academy of Sciences Beijing 100049China POWERCHINA Chengdu Engineering Corporation Limited Chengdu 611130SichuanChina Hubei Engineering Research Center for Protection and Utilization of Special Biological Resources in the Hanjiang River Basin School of Life ScienceJianghan UniversityWuhan 430056HubeiChina

A new species of the genus Liurana is described from Medog,Xizang,China,based on morphological and molecular *** phylogenetic analysis based on the mitochondrial gene COI indicated that this new species represented an independent evolutionary *** addition,the uncorrected genetic distance between the new species and its closest congener species,***,was 9.6%-9.8%for *** new species,Liurana namchabarwa ***,lin,Wang,Jiang and Xie,could be distinguished from its congeners by following characters:(1)relatively large body size in this genus,SVL=21.2-23.1 mm in adult males(n=3);(2)relatively narrow head(HL/HW=100.5%-104.8%(n=3));(3)digital disc not expanded;(4)relatively long hindlimbs,with tibiotarsal articulation reaching tip of snout when adpressed.

关键词： Liurana namchabarwa sp.nov. molecular phylogenetic analyses morphology taxonomy