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Interaction specific binding hotspots in Endonuclease colicin-immunity protein complex from MD simulations

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Science China Chemistry 2013年第8期56卷 1143-1151页

作者： YAO XueXia JI ChangGe XIE DaiQian ZhANG John Z.h. School of Chemistry and Chemical Engineering Nanjing University College of Engineering Nanjing Agricultural University State Key Laboratory of Precision Spectroscopy Department of PhysicsEast China Normal University Department of Chemistry New York University

The binding of Endonuclease colicin 9 (E9) by Immunity protein 9 (Im9) was found to involve some hotspots from helix III of Im9 on protein-protein interface that contribute the dominant binding energy to the *** the current work,MD simulations of the WT and three hotspot mutants (D51A,Y54A and Y55A of Im9) of the E9-Im9 complexes were carried out to investigate specific interaction mechanisms of these three hotspot *** changes of binding energy between the WT and mutants of the complex were computed by the MM/PBSA method using a polarized force field and were in excellent agreement with experiment values,verifying that these three residues were indeed hotspots of the binding *** decomposition analysis revealed that binding by D51 to E9 was dominated by electrostatic interaction due to the presence of the carboxyl group of Asp51 which hydrogen bonds to *** binding by hotspots Y54 and Y55,van der Waals interaction from the aromatic side chain of tyrosine provided the dominant *** comparison,calculation by using the standard (nonpolarizable) AMBER99SB force field produced binding energy changes from these mutations in opposite direction to the experimental *** hydrogen bond analysis showed that conformations sampled from MD simulation in the standard AMBER force field were distorted from the native state and they disrupted the inter-protein hydrogen bond network of the protein-protein *** current work further demonstrated that electrostatic polarization plays a critical role in modulating protein-protein binding.

关键词： protein-protein interaction binding hotspot mutation Endonuclease Colicin immunity protein MD simulation

Semisolid joining of aluminum A356 alloy by partial remelting and mechanical stirring

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Transactions of Nonferrous Metals Society of China 2010年第9期20卷 1792-1798页

作者： S.M.J.ALVANI h.AAShURI A.KOKABI R.BEYGI Materials Science and Engineering Department Sharif University of Technology

A method to reach the globular weld structure of A356 aluminum alloy using stirring the localized semisolid zone during butt-joining is *** the heat conductivity of this alloy is very high, the accurate controlling of temperature during joining must be considered.A gas heating system was used to heat up the nitrogen gas up to the required temperature.A dried and free oxygen gas was prepared when a stream of nitrogen gas could pass closely around a hot *** and pure nitrogen gas flow through a precise ceramic nozzle was used to create a localized semisolid *** this stage a fine stirrer was introduced into the weld seam in order to mix the two sides into a single uniform *** were moved in direction of joint line by a small trolley to avoid the deviation of nozzle from the joint line and its distance and angle from the substrate.A fixture system was used to hold two substrates together on the trolley.A narrow hot plate was located on the trolley to heat up the joint line due to high heat conductivity of *** of gas temperature was investigated on the microstructure and mechanical properties of weld *** showed that increase in temperature promoted the final welding properties, and also at liquid fractions less than 50% joining was not fully *** best mechanical properties were achieved with liquid fraction of about 70%.

关键词： semisolid joining A356 localized stirring shear punch semi-solid holding thermal treatment

Impulsive effect on exponential synchronization of neural networks with leakage delay under sampled-data feedback control

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Chinese Physics B 2014年第7期23卷 218-229页

作者： S.Lakshmanan Ju h.Park Fathalla A.Rihan R.Rakkiyappan Department of Mathematical Sciences College of ScienceUAE University Nonlinear Dynamics Group Department of Electrical EngineeringYeungnam University Department of Mathematics Bharathiar University

We consider the impulsive effect on the exponential synchronization of neural networks with leakage delay under the sampled-data feedback control. We use an appropriate Lyapunov-Krasovskii functional combined with the input delay approach and some inequality techniques to derive sufficient conditions that ensure the exponential synchronization of the delayed neural network. The conditions are formulated in terms of the leakage delay, the sampling period, and the exponential convergence rate. Numerical examples are given to demonstrate the usefulness and the effectiveness of the results.

关键词： exponential synchronization impulsive effect leakage delay sampled-data feedback

A preliminary experimental study of the boron concentration in vapor and the isotopic fractionation of boron between seawater and vapor during evaporation of seawater

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Science China Chemistry 2001年第5期44卷 540-551页

作者：肖应凯 G.h.Swihart 肖云 R.D.VockeJr. Qinghai Institute of Salt Lakes Chinese Academy of Sciences Xining China Department of Geological Sciences The University of Memphis Memphis USA Inorganic Analytical Chemistry Division National Institute of Standards and Technology Gaithersburg USA

A laboratory experiment was undertaken to investigate the behaviour of boron at the seawater-air interface under air flow conditions. Dried air at 25 and 35℃ was passed over or bubbled through seawater at the same temperature. A combination of ice-chilled condensers and KOh impregnated cellulose fibre filters was used to collect boron from the reacted air. When air stripped of boron was passed over the seawater, boron was found in the reacted air, and its concentration was higher in the higher temperature test. In the tests where air was bubbled through seawater the concentration of boron in the reacted air was directly proportional to the air flow rate. In this situation the boron in the reacted air was mainly introduced as a spray of microdroplets. Isotopic analysis of the collected boron in the non-bubbled tests yields fractionation factors which demonstrate that the lighter isotope, 10B, is enriched in the reacted air. The size of the fractionation changes with temperature, ruling out a purely kinetic effect.

关键词： boron isotope isotopic fractionation evaporation seawater.

Effects of Radix Ginseng on microbial infections: a narrative review

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Journal of Traditional Chinese Medicine 2014年第2期34卷 227-233页

作者： hong Wu Niels hфiby Liang Yang Michael Givskov Zhijun Song Department of International health Immunology & MicrobiologyUniversity of Copenhagen Department of Clinical Microbiology Singapore Centre on Environmental Life Sciences Engineering Nanyang Technological University Department of Clinical Microbiology RigshospitaletUniversity Hospital of Copenhagen Department of Clinical Microbiology Slagelse Hospital

OBJECTIVE: To summarized the antimicrobial-like effects of Radix Ginseng, which provide important information to the relevant researchers and clinicians, and will benefit the clinical treatment of infectious ***: PubMed and Google were used to search for and collect scientific publications related to Radix Ginseng and microbial infections. The authors read, classified, and discussed the associated scientific results or evidences, and summarized the corresponding ***: In this review, recent studies on the bene-ficial effects of Radix Ginseng extracts on microbial and biofilm infections were reviewed. The importance and significance of Radix Ginseng's beneficial effects are discussed. Evidence for the favorable effects of Radix Ginseng extracts on viral, bacterial,fungal, and parasitic infections and the possible underlying mechanisms are ***: Radix Ginseng might be a promising supplemental remedy for the prevention and treatment of infectious diseases.

关键词： Radix Ginseng Viruses Bacteria Fungi Biofilms Parasitology Review

Effect of Fuel to Oxidant Molar Ratio on Structural and DC Electrical Conductivity of ZnO Nanoparticles Prepared by Simple Solution Combustion Method

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Journal of Materials Science & Technology 2013年第10期29卷 898-902页

作者： C.S.Naveen M.L.Dinesha h.S.Jayanna Department of PG Studies and Research in Physics Kuvempu University

ZnO nanoparticles of different sizes were prepared by varying the molar ratio of glycine and zinc nitrate hexahydrate as fuel and oxidizer （0.1, 0.8, 1.11, 1.3, 1.5, 1.7, 2.0） by simple solution combustion method. UV-Visible spectrophotometry studies show that, the band gap of the prepared ZnO nanoparticles increases with increasing fuel to oxidant （F/O） molar ratio up to 1.7 revealing the formation of ZnO nanoparticles. The decrease in band gap for the sample of F/O molar ratio 2.0 is due to an increase in particle size. Powder X-ray diffraction patterns of the prepared samples show the formation of single phase ZnO nanoparticles and the particle size decreases with increasing F/O molar ratio up to 1.7. Surface morphology of the prepared samples was studied by scanning electron microscopy and it was observed that, the porosity increases with increasing F/O molar ratio. DC electrical conductivity at room temperature and in the temperature range of 303-563 K was studied for all the samples and the results revealed that, the sample of F/O molar ratio 1.7 has low electrical conductivity at room temperature and high EAR （high temperature activation energy） compared to other samples.

关键词： ZnO nanoparticles Structural characterization Electrical conductivity

hOMOTOPY PERTURBATION SOLUTION AND PERIODICITY ANALYSIS OF NONLINEAR VIBRATION OF ThIN RECTANGULAR FUNCTIONALLY GRADED PLATES

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Acta Mechanica Solida Sinica 2014年第2期27卷 210-220页

作者： A.Allahverdizadeh R.Oftadeh M.J.Mahjoob M.h.Naei School of Engineering - Emerging Technologies University of Tabriz School of Mechanical Engineering College of Engineering University of Tehran Department of Mechanical and Industrial Engineering Northeastern University

In this paper nonlinear analysis of a thin rectangular functionally graded piate is formulated in terms of von-Karman＇s dynamic equations. Functionaily Graded Material （FGM） properties vary through the constant thickness of the plate at ambient temperature. By expansion of the solution as a series of mode functions, we reduce the governing equations of motion to a Duffing＇s equation. The homotopy perturbation solution of generated Duffing＇s equation is also obtained and compared with numerical solutions. The sufficient conditions for the existence of periodic oscillatory behavior of the plate are established by using Green＇s function and Schauder＇s fixed point theorem.

关键词： nonlinear vibration FGM rectangular plate Schauder's fixed point theorem homotopy perturbation method

Dilemma of concepts and strategies for the prevention of spread of hIV in relation to human behavior,law and human rights

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Journal of Zhejiang University-Science B(Biomedicine & Biotechnology) 2011年第7期12卷 591-610页

作者： Reinhard h. DENNIN Michael LAFRENZ Amdt SINN Lan-juan LI Institute of Medical Microbiology and hygiene University of Luebeck Campus Luebeck 160 Ratzeburger Allee Luebeck D-23538 Germany AIDS Medical Board Medical Association Rostock MV 18055 Germany Centre for European and International Criminal Law Studies (ZEIS) University of Osnabriick Osnabrueck 49076 Germany State Key Laboratory for Diagnosis and Treatment of Infectious Disease the First Affiliated Hospital School of Medicine Zhejiang University Hangzhou 310003 China

The new prevalence data regarding the estimated global number of human immunodeficiency virus positive (hIV+) cases,i.e.,including people who are either aware or unaware of their hIV infection in 2010,lead many to wonder why the increase in incidence has reached today’s unprecedented level and escalated within such a short ***,in spite of prevention campaigns in countries affected by hIV/acquired immune deficiency syndrome (AIDS) with their urgent messages aimed at preventing hIV transmission by promoting changes in individual’s *** article analyzes the background of the prevention strategies,in particular their political,social and legal concepts in terms of human rights,and reveals traits of human behavior not considered thus far.A radical reappraisal is necessary,at social and legislative levels,as well as options additional to current *** ethical issues come up,they become blamed for outmoded moralistic ***,ignoring the reality has led to dire consequences from prioritizing individual human rights over society’s collective need to prevent the spread of hIV.

关键词： hIV Prevention human rights Fundamental rights Jurisdiction Decriminalization

A creative method to tune Fe–O interaction in ferrites

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先进陶瓷(英文) 2023年第8期12卷 1612-1624页

作者： Farshad Farshidfar Arash Fattahi Ralf Brüning Dominic h.Ryan Khashayar Ghandi Department of Chemistry University of GuelphGuelph N1G 2W1Canada Physics Department Mount Allison UniversitySackville E4L 1E6Canada Physics Department McGill UniversityMontreal H3A 2T8Canada

To be able to regulate the anionic oxygen position in ferrites,an original compositing method is developed by introducing a porous p-type phase in the n-type matrix of ferrite spinel semiconductors.A result of this method is the synergetic effect of the enhanced mass and charge transport that impacted the morphology and anionic oxygen position within the MgFe_(2)O_(4) *** hypothesis is that fine tuning of the anionic oxygen position in ferrites allows us to regulate their physicochemical properties significantly,with the implications for diverse *** electron exchange interaction(J)between O-centered and octahedral-occupying iron(Fe)-centered orbitals affected both the electrical and magnetic properties of the matrix significantly,supporting our *** three-dimensional variable range electron hopping is one such effect.

关键词： Fe_(2)O_(4) spinel structural distortion electron hopping