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Status of study on biological and toxicological effects of nanoscale materials

Science china chemistry 2005年第5期48卷 385-394页

作者： WAnG Bing1, FEnG Weiyue1, ZHAO Yuliang1, XInG Gengmei1, CHAI Zhifang1, WAnG Haifang2 & jiA Guang3.1. Laboratory for Bio-Environmental Health Sciences of nanoscale Materials (nanosafety Lab), Institute of High Energy Physics, Chi-nese Academy of Sciences, Beijing 100049, china 2. College of chemistry and Molecular Engineering, Peking university, Beijing 100871, china 3. department of Occupational and Environmental Health Sciences, School of Public Health, Peking university, Beijing 100083. china Laboratory for Bio-Environmental Health Sciences of nanoscale Materials (nanosafety Lab) Institute of High Energy Physics Chinese Academy of Sciences Beijing China College of chemistry and Molecular Engineering Peking University Beijing China department of Occupational and Environmental Health Sciences School of Public Health Peking University Beijing China

Because the physical and chemical properties of nanosized materials mostly differ from the existing microsized materials, their potential impacts on human health and the envi-ronment will be topics under the serious discussions in press and in a number of international scientific journals. We analyze and summarize the existing data of the experimental study on the biological activities and adverse effects of nanoscale materials/particles including single wall carbon nanotubes, multi wall carbon nanotubes, titanium oxide and iron powders. Though some biological behaviors of nanoscale materials observed cannot be understood on the basis of the current knowledge, as the existing data are mostly preliminary, it is too early to make some ex-clusive conclusions on biological activities (or the toxicity) of any of nanoscale materials. The experimental techniques, the current topics, and the future research directions for this new re-search field are also discussed.

关键词： nanomaterials, single wall carbon nanotubes, multi wall carbon nanotubes, titanium oxide and iron, biological activity and toxicological effect.

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EPR studies of Mn^(2+) in the Loess Plateau of central china: Implication for variation of the East Asia summer monsoon

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Chinese Science Bulletin 1998年第1期43卷 72-75页

作者： CHEn Jun\+1, ji Junfeng\+1, SU Yuanxia\+2 and LU Huayu\+3.. department of Earth Sciences, nanjing university, nanjing 210093. china 2. Center of Material Analysis, nanjing university, nanjing 210093. china 3. Xi’an Laboratory of Loess and Qu department of Earth Sciences Nanjing University Nanjing China Center of Material Analysis Nanjing University Nanjing China Xi’an Laboratory of Loess and Quaternary Geology Chinese Academy of Sciences Xi’an China

Mn 2+ EPR intensity recorded in the Chinese loess_paleosol sequence shows close correlation with magnetic susceptibility and Sr content as well as the oscillation of paleoclimate. Thus Mn 2+ EPR signal can serve as an... 详细信息

关键词： paleomonsoon loess paleosol EPR signal of Mn 2+

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Local electronic structure and magnetic properties of 3. transition metal doped GaAs

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Science china(Physics,Mechanics & Astronomy) 2008年第5期51卷 470-480页

作者： LIn He1 & DUAn HaiMing21 department of chemistry,Institute of Applied chemistry,Xinjiang {3.,Urumqi 83.046,china 2department of Physics,Xinjiang {3.,Urumqi 83.046,china department of chemistry Institute of Applied Chemistry Xinjiang University Urumqi China department of Physics Xinjiang University Urumqi China

The local electronic structure and magnetic properties of GaAs doped with 3. transition metal (Sc, Ti, V, Cr, Mn, Fe, Co, ni) were studied by using discrete variational method (DVM) based on density functional theory. The calculated result indicated that the magnetic moment of transition metal increases first and then decreases, and reaches the maximum value when Mn is doped into GaAs. In the case of Mn concentration of 1.4%, the magnetic moment of Mn is in good agreement with the experimental result. The coupling between impure atoms in the system with two impure atoms was found to have obvious variation. For different transition metal, the coupling between the impure atom and the nearest neighbor As also has different variation.

关键词： diluted magnetic semiconductor density functional theory 3. transition metal cluster model electronic structure

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Algorithm of graph isomorphism with threedimensional DnA graph structures

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Progress in natural Science:Materials International 2005年第2期15卷 86-89页

作者： LIU Guangwu 1,2*, YIn Zhixiang 1,3. XU jin1 and DOnG Yafei1(1. department of Control Science and Engineering, Hua Zhong university of Science and Technology, Wuhan 43.074, china 2. College of Transportation, Wuhan university of Technology, Wuhan 43.063. china 3. department of Mathematics and Physics, Anhui university of Science and Technology, Huainan 23.001, china) Dept. of Control Science and Eng. Huazhong Univ. of Sci. and Technol. Wuhan 430074 China Coll. of Transportation Wuhan Univ. of Technology Wuhan 430063 China Dept. of Mathematics and Physics Anhui Univ. of Sci. and Technol. Huainan 232001 China

An algorithm for solving the graph isomorphism problem with 3.D DnA structures is proposed in this paper. The k-armed branched junction molecules are used to code k-degree vertices. Double stranded molecules are used to code edges. Then the molecules are mixed in a tube to be ligated. The result can be detected by gel electrophoresis. The time complexity of the algorithm is O(n2), where n is the number of vertices of the graph.

关键词： DnA computing DnA graph structure graph isomorphism

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Characteristics of fMRI BOLD signal and its neurophysiological mechanism

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Progress in natural Science:Materials International 2007年第6期17卷 630-638页

作者： Zhao Xiaohu1,2, Wu Yigen3.and Guo Shengli3.1. College of Life Sciences, Zhejiang university, Hangzhou 3.0058, china 2. Imaging department of Tongji Hospital of Tongji university, Shanghai 200065, china 3. College of Mathematics and Physics, nanjing university of Information Science and Technology, nanjing 210044, china) College of Life Sciences Zhejiang University Hangzhou 310058 China Imaging department Tongji Hospital Tongji University Shanghai 200065 China College of Mathematics and Physics Nanjing University of Information Science and Technology Nanjing 210044 China

The functional magnetic resonance imaging (fMRI) based on blood oxygen level dependent (BOLD) contrast has emerged as one of the most potent noninvasive tools for mapping brain function and has been widely used to explore physiological, pathological changes and mental activity in the brain. Exploring the nature and property of BOLD signal has recently attracted more attentions. Despite that great progress has been made in investigation of the characteristics and neurophysiological basis, the exact nature of BOLD signal remains unclear. In this paper we discuss the characteristics of BOLD signals, the nonlinear BOLD response to external stimuli and the relation between BOLD signals and neural electrophysiological recordings. Furthermore, we develop our new opinions regarding nonlinear BOLD response and make some perspectives on future study.

关键词： functional magnetic resonance imaging blood oxygen level dependent nonlinear response neural electrophysiological activity.

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Smoothness for the collision local times of bifractional Brownian motions

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Science china Mathematics 2011年第9期54卷 1859-1873页

作者： SHEn GuangJun 1,2,& YAn LiTan 3.1 department of Mathematics,East china university of Science and Technology,Shanghai 20023.,{3. 2 department of Mathematics,Anhui normal university,Wuhu 241000,{3. 3.department of Mathematics,Donghua university,Shanghai 201620,{3. department of Mathematics East China University of Science and Technology Shanghai China department of Mathematics Anhui Normal University Wuhu China department of Mathematics Donghua University Shanghai China

Let B^Hi,Ki ={ Bt^Hi,Ki, t ≥ 0}, i= 1, 2 be two independent bifractional Brownian motions with respective indices Hi ∈ （0, 1） and K∈ E （0, 1]. One of the main motivations of this paper is to investigate f0^Tδ（Bs^H1 ,K1 - the smoothness of the collision local time, introduced by jiang and Wang in 2009, IT = f0^T δ（Bs^H1,K1）ds, T 〉 0, where 6 denotes the Dirac delta function. By an elementary method, we show that iT is smooth in the sense of the Meyer-Watanabe if and only if min{H-1K1, H2K2} 〈-1/3.

关键词： bifractional Brownian motion collision local time intersection local time chaos expansion

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γ-Hydroxy-α,β-acetylenic esters:asymmetric syntheses and applications

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Science china chemistry 2010年第1期53卷 21-35页

作者： GAO Ge1 & PU Lin2 1department of chemistry,Sichuan university,Chengdu 610064,{3. 2department of chemistry,university of Virginia,Charlottesville,Virginia 22904-43.9,USA department of chemistry Sichuan University Chengdu China department of chemistry University of Virginia Charlottesville USA

γ-Hydroxy-α,β-acetylenic esters are versatile synthetic precursors to many organic *** paper reviews the synthesis of chiral γ-hydroxy-α,β-acetylenic esters by asymmetric reduction of γ-oxo-α,β-acetylenic esters,enantioselective addition to aldehydes in the presence of chiral catalysts,and diastereoselective addition to chiral *** preparation of racemic γ-hydroxy-α,β-acetylenic esters is also *** are provided for the application of γ-hydroxy-α,β-acetylenic esters in organic synthesis.

关键词： γ-hydroxy-α β-acetylenic ester asymmetric enantioselective diastereoselective

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Theoretical study on thermal decomposition of azoisobutyronitrile in ground state

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Science china chemistry 2004年第5期47卷 373-380页

作者： SUn Chengke1,2, ZHAO Hongmei1 & LI Zonghe1 1. department of chemistry, Beijing normal university, Beijing 100875,{3. 2. department of chemistry, Qujing normal College, Qujing 655000,{3. Dept. of Chem. Beijing Normal Univ. Beijing 100875 China Dept. of Chem. Qujing Normal Coll. Qujing 655000 China

The thermal decomposition mechanisms of azoisobutyronitrile (AIBn) in the ground state have been investigated systematically. Based on the potential energy surfaces (PES) of various possible dissociation paths obtained using the semiempirical AM1 method with partial optimization, the density function theory B3.YP/6-3.1G* method was employed to optimize the geometric parameters of the reactants, the intermediates, the products and the transition states, which were further confirmed by the vibrational analysis. The obtained results show that the re- action process of the two-bond (three-body) simultaneous cleavage Me2(Cn)C─ n=n─ C(Cn)Me2? 2Me2(Cn)C?+n2 is much more favorable than the reaction process of the two one- bond asynchronous cleavage Me2(Cn)Cn=n─C(Cn)Me2 ? Me2(Cn)Cn=n?+ Me2(Cn)C?? Me2(Cn)C?+ n2. It was suggested that the electron shrinking effect of double bond (─n=n─) in AIBn and the stabilities of the Me2(Cn)C?radical as well as n2 molecule are main factors of leading to the reaction proceeding in the former pathway. The calculation results were consistent with all the experimental facts.

关键词： azoisobutyronitrile, radicals, thermal decomposition, density function theory (DFT).

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Doxepin protects cultured neurons against oxidative stress-induced injury

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Acta Pharmacologica Sinica 2004年第3期25卷 43-46页

作者： Bian-sheng ji,He ji1,Guo-qing LIU2 department of Pharmacology,china Pharmaceutical university,nanjing 210009 1department of Medicine,Henan university,Kaifeng 475001,china department of Pharmacology China Pharmaceutical University Nanjing 210009 department of Mecine Henan University Kaifeng 475001

AIM: To investigate protective effects of doxepin (Dox) on cultured neuronal injury induced by oxidative stress. METHODS: Cytotoxicities of glutamate (Glu 0.5 mmol/L, 15 min), sodium dithionite (0.5 mmol/L, 24 h) or hemo- globin (Hb100 mg/L,24 h)and the protective effects of Dox were observed. RESULTS: Exposure of cultured neurons to Glu, sodium dithionite and Hb developed a neurotoxicity expressed in the thiazol blue tetrazolium bro- mide (MTT) assay, the increase of lactate dehydrogenase (LDH) leakage, malondialdehyde (MDA) content and intracellular [Ca2+]i accumulation, as well as the decrease of superoxide dismutase (SOD) activity. DOX 1-100 nmol/L significantly inhibited all above changes. COnCLUSIOn: Dox protects cultured neurons against oxidative stress-induced injury by suppressing intracellular [Ca2+]iaccumulation, decreasing lipid peroxide generation and stimulating antioxidant enzyme.

关键词： doxepin ischemia glutamic acid hemoglobins neurons

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Synthesis of vertically aligned carbon nanotube arrays on silicon substrates

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Science china(Technological Sciences) 2004年第5期47卷 616-624页

作者： ZHEnG Ruiting1, CHEnG Guoan1, PEnG Yibin1, 2, ZHAO Yong1, 3. LIU Huaping1 & LIAnG Changlin1 1. Key Laboratory of Radiation Beam Technology and Materials Modification of Ministry of Education, department of Materials Science and Engineering, Beijing normal university, Beijing 100875, china 2. School of Science, Civil Aviation university of china, Tianjin 3.03.0, china 3. department of Physics, nanchang university, nanchang 3.0047, china Correspondence should be addressed to Zheng Ruiting Key Laboratory of Radiation Beam Technology and Materials Modification of Ministry of Education Department of Materials Science and Engineering Beijing Normal University Beijing China School of Science Civil Aviation University of China Tianjin China department of Physics Nanchang University Nanchang China

The growth of well-aligned carbon nanotube (CnT) arrays using a heat chemical vapor deposition system on silicon substrates is reported. The growth properties of CnT arrays are studied as a function of synthesis conditions. It is found that 750°C and 10 nm Fe film are suitable conditions for the growth of well-aligned CnT arrays. CnT arrays with a uniform diameter, thick tube wall and firm cohesion to the Si substrate can be grown for C2H2 concentration of 27%. Based on the experiment, the processes of improving the alignment of CnT arrays and cohesion between CnT arrays and Si substrates are discussed.

关键词： carbon nanotubes, vertically aligned, silicon substrate, chemical vapor deposition.

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