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Cleavage of Supercoiled Circular Double-stranded DNA Induced by a Eukaryotic Cambialistic Superoxide Dismutase from Cinnamomum camphora

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Acta Biochimica et Biophysica sinica 2004年第9期36卷 609-617页

作者： Bao-Zhong WANG, Xu-Bin WEI&, and Wang-Yi LIU* State Key Laboratory of molecular Biology, institute of Biochemistry and Cell Biology, Shanghai institutes for Biological sciences,Chinese Academy of sciences, Shanghai 200031, china State Key Laboratory of molecular Biology Institute of Biochemistry and Cell Biology Shanghai Institutes for Biological Sciences Chinese Academy of SciencesShanghai 200031 China

A eukaryotic cambialistic superoxide dismutase (SOD) has been purified to homogeneity from mature seeds of the disease- and insect-resistant camphor tree (Cinnamomum camphora). Besides the known role of this SOD in protecting cells against oxidative stress, it can induce the cleavage of supercoiled double-stranded DNA into nicked and linear DNA. It can not cleave linear DNA or RNA, demonstrating there is no DNase or RNase in the purified cambialistic SOD. Furthermore, the SOD can linearize circular pGEM-4Z DNA that is relaxed by topoisomerase I. This result indicates that the DNA-cleaving activity re- quires substrates being topologically constrained. The supercoiled DNA-cleaving activity of the cambialistic SOD can be inhibited by either SOD inhibitor (azide) or catalase and hydroxyl radical scavengers (ethanol and mannitol). The chelator of iron, diethylenetriaminepentaacetic acid (DTPA), also inhibits the supercoiled DNA-cleaving activity. These results show that the dismutation activity is crucial for the supercoiled DNA cleavage. The modification of tryptophan residue of the cambialistic SOD with N-bromosuccinimide (NBS) shows that these two activities are structurally correlative. The reaction mechanism is proposed that the hydroxyl radical formed in a transition-metal-catalyzing Fenton-type reaction contributes to the DNA- cleaving activity. In addition, the cleavage sites in supercoiled pGEM-4Z DNA are random.

关键词： cambialistic SOD Fenton-type reaction hydroxyl radical relaxed circular duplex DNA supercoiled DNA cleavage

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Regulation of mammalian pre-mRNA splicing

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Science china(Life sciences) 2009年第3期52卷 253-260页

作者： HUI JingYi State Key Laboratory of molecular Biology,institute of Biochemistry and Cell Biology,Shanghai institutes for Biological sciences,Chinese Academy of sciences,Shanghai 200031,china State Key Laboratory of molecular Biology Institute of Biochemistry and Cell Biology Shanghai Institutes for Biological Sciences Chinese Academy of Sciences Shanghai China

In eukaryotes,most protein-coding genes contain introns which are removed by precursor messenger RNA(pre-mRNA) *** splicing is a process by which multiple messenger RNAs(mRNAs) are generated from a single pre-mRNA,resulting in functionally distinct *** genome-wide analyses of alternative splicing indicated that in higher eukaryotes alternative splicing is an important mechanism that generates proteomic complexity and regulates gene ***-regulation of splicing causes a wide range of human *** review describes the current understanding of pre-mRNA splicing and the mechanisms that regulate mammalian pre-mRNA *** also discusses emerging directions in the field of alternative splicing.

关键词： pre-mRNA splicing alternative splicing splicing regulation signal transduction microRNA

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Theoretical research progress in complexity of complex dynamical networks

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Progress in Natural Science:Materials International 2007年第7期17卷 761-774页

作者： Fang Jinqing(Joint Complex Network Research Group,china institute of atomic Energy,Beijing 102413,china) Joint Complex Network Research Group China Institute of Atomic Energy Beijing 102413 China

This article reviews the main progress in dynamical complexity of theoretical models for nonlinear complex networks proposed by our Joint Complex Network Research Group(JCNRG).The topological and dynamical properties of these theoretical models are numerically and analytically *** findings are useful for understanding and deeply studying complex networks from macro- scopic to microscopic levels and have a potential of applications in real-world networks.

关键词： Harmonions unifying hybrid preferential model a large unifying hybrid network model quantum interference network nonowire networks generalized local-world model non-local links model evolving model of weighted networks small-world network with the unchanged degree

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Identification of γ1 subunit of GABAA receptor in rat testis

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Cell Research 2002年第1期12卷 33-37页

作者： JING HUA HU, YUAN CHANG YAN Lab of molecular Cell Biology, institute of Biochemistry and Cell Biology, Shanghai institutes for Biological sciences, Chinese Academy of sciences, Shanghai 200031, china Lab of molecular Cell Biology Institute of Biochemistry and Cell Biology Shanghai Institutes for Biological Sciences Chinese Academy of Sciences Shanghai China

The isoform type ofγsubunits of GABAA receptor is a molecular determinant of its pharmacological characteristics. At present, the existence of GABAA receptor in mammalian sperm is still a controversy. By using degenerate primers designed according to highly conserved region in all threeγ(γ1, γ2 andγ3) subunits cloned in rat brain, we performed reverse transcription polymerase chain reaction (RT-PCR) to examine the expression pattern of -γsubunits of GABAA receptor in rat testis. Only one 370 bp fragment was obtained from RT-PCR in rat testis and sequencing results showed that it representedγ1 subunit, but notγ2 orγ3 subunit. Using the cloned fragment as probe, a 3.8 kb transcript which in size as same asγ1 ubunit in rat brain was detected in rat testis mRNA by performing Northern blot assay. Furthermore, results of in situ hybridization assay confirmed thatγ1 subunit was expressed in round spermatids and spermatozoa, maybe also in secondary spermatocyte. These evidences proved that 71 subunit of GABAA receptor is exclusively expressed in rat testis and this feature may be the structural basis of the specific function of GABAA receptors in sperm acrosome reaction.

关键词： GABAA receptor rat testis γ1 subunit.

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High-resolution photofragment translational spectro- scopy for the UV photodissociation of C_2H_5I

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Science china Chemistry 2007年第4期50卷 476-482页

作者： BI WeiBin, XU XiLing, HUANG JianGou, XIAO DaoQing & ZHU QiHe Beijing National Laboratory for molecular sciences, State Key Laboratory of molecular Reaction Dynamics, institute of Chemistry, Chinese Academy of sciences, Beijing 100080, china Beijing National Laboratory for molecular sciences State Key Laboratory of Molecular Reaction Dynamics Institute of Chemistry Chinese Academy of Sciences Beijing China

The photodissociation of ethyl iodide at 279.71, 281.73, 304.02 and 304.67 nm has been studied on our new mini-photofragment translational spectrometer with a total flight path of only 5 cm. Some vibra-tional peaks are firstly resolved in the TOF spectra of I*(2P1/2) and I(2P3/2) channels. These vibrational peaks are assigned to the excitation states (ν2 = 0, 1, 2,…) of the umbrella mode (ν2, 540 cm-1) of the photofragment C2H5, and the distribution of the vibrational states is obtained. The dissociation energy has been determined to be D0(C-I)=2.314 ± 0.03 eV. The energy partitioning of the available energy (Eavl=ET+Eint=ET+EV,R) calculated from our experimental data E int /E avl= 22.1% at 281.73 nm, 22.4% at 304.02 nm for the I* channel, and E int /E avl= 25.2% at 279.71 nm, 25.9% at 304.67 nm for the I channel, seem to be more reliable.

关键词： photofragment translational spectroscopy C2H5I photodissociation vibrational state distribution energy partitioning dissociation energy

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A　STATISTICAL　THEORY　FOR　THE　BIO-PHOTON　EMISSION　OF　THE　LIVING　SYSTEMS

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原子与分子物理学报 1997年第1期 132-140页

作者： Pang Xiaofeng International Centre for Material Physics, academia sinica Dept. of Physics, Southwest institute for Nationalities The Institue of atomic and molecular Physics, Sichuan Union UniversityShenyang Chengdu Chengdu110015 610051 610065

ＡＳＴＡＴＩＳＴＩＣＡＬＴＨＥＯＲＹＦＯＲＴＨＥＢＩＯ－ＰＨＯＴＯＮＥＭＩＳＳＩＯＮＯＦＴＨＥＬＩＶＩＮＧＳＹＳＴＥＭＳＰａｎｇＸｉａｏｆｅｎｇＩｎｔｅｒｎａｔｉｏｎａｌＣｅｎｔｒｅｆｏｒＭａｔｅｒｉａｌＰｈｙｓｉｃ... 详细信息

ＡＳＴＡＴＩＳＴＩＣＡＬＴＨＥＯＲＹＦＯＲＴＨＥＢＩＯ－ＰＨＯＴＯＮＥＭＩＳＳＩＯＮＯＦＴＨＥＬＩＶＩＮＧＳＹＳＴＥＭＳＰａｎｇＸｉａｏｆｅｎｇＩｎｔｅｒｎａｔｉｏｎａｌＣｅｎｔｒｅｆｏｒＭａｔｅｒｉａｌＰｈｙｓｉｃｓ，ＡｃａｄｅｍｉａＳｉｎｉｃａＤ...

关键词： Bio photon emission Molecules Negative entropy Living things Statistical theory of non equilibrum state Bio self organization

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Biasing fluctuation model for directional stepping motion of molecular motor

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Chinese Science Bulletin 1998年第22期43卷 1879-1882页

作者： BAO Jingdong 1 and ZHUO Yizhong 2 1. Beijing Meteorological College, Beijing 100081, china 2. china institute of atomic Energy, Beijing 102413, china Beijing Meteorological College Beijing China china institute of atomic Energy Beijing China

The biasing fluctuation model with a colored noise is presented to study the directional stepping motion of the molecular motor. The expression of probability current is obtained in the adiabatic approximation. The fo... 详细信息

关键词： molecular motor stepping motion biasing force colored noise Langevin equation.

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VISCOELASTIC BEHAVIOR OF THE NON-HOOKE DEFORMATION BEFORE YIELDING IN UNIAXIAL DRAWING OF AMORPHOUS POLY(ETHYLENE TEREPHTHALATE)

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Chinese Journal of Polymer Science 2001年第4期19卷 399-405页

作者： Zhen-hua Yuan De-yan Shen Ren-yuan Qian Polymer Physics Laboratory Center for molecular Science, institute of Chemistry Chinese Academy of sciences, Beijing 100080 china 中科院化学所高分子物理及化学国家重点实验室北京

Viscoelastic behavior of the non-Hooke deformation of amorphous PET film before yield was investigated in the temperature region 74-80.5 degreesC around the glass transition temperature. The film specimen was drawn to yield point followed by unloading to zero stress, then the residual deformation was held constant; while the subsequent evolution of the stress was recorded. An induction period was found in the course of stress evolution followed by a stress step-increase. The induction period decreases with increasing drawing temperature with an activation energy of 1.10 MJ/mol.K, which is attributed to the time needed for the relaxation of rubbery deformation through cooperative internal rotations. At temperatures lower than 74 degreesC, there is no stress increase or the induction period becomes too long to be observed. Thus the nature of anelasticity in the non-Hooke region before yielding is attributed to stress induced rubbery deformation. The experimental results are interpreted in terms of Perez' theological model of a series connected Hooks spring and a Voigt element consisting of a parallel connected elastic spring and a dashpot.

关键词： pre-yield deformation PET uniaxial drawing non-Hooke deformation viscoelasticity stress induced rubbery deformation

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陨石、超基性岩、花岗岩及其主矿物中某些微量元素的仪器中子活化分析

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地球化学 1976年第2期5卷 133-143页

作者： METEOEITE ANALYSIS GROUPinstitute of atomic Energy, academia sinica Guiyang institute of Geochemistry, academia sinica 中国科学院原子能研究所陨石分析组中国科学院贵阳地球化学研究所陨石分析组

研究地球物质中化学元素的分布、迁移和转变的规律，进一步探讨地球的形成与演化过程是地球化学的主要课题之一。球粒陨石的平均化学组成可能代表着形成太阳系的太阳星云的平均化学组成，也是组成地球的初始物质，而地壳上的各种岩浆岩... 详细信息

研究地球物质中化学元素的分布、迁移和转变的规律，进一步探讨地球的形成与演化过程是地球化学的主要课题之一。球粒陨石的平均化学组成可能代表着形成太阳系的太阳星云的平均化学组成，也是组成地球的初始物质，而地壳上的各种岩浆岩都是从地球的初始物质经过熔融、调整、演化而逐渐形成的。我们通过对普通球粒陨石、超基性岩。

关键词：地球化学球粒陨石化学组成超基性岩花岗岩微量元素中子活化分析

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STRUCTURE AND SURFACE CONDITION OF ULTRAFINE AI PARTICLES

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Acta Metallurgica sinica(English Letters) 1992年第6期5卷 402-408页

作者： SUN Xiukui CHEN Wenxiu XU Jian FAN Xueshu WEI Wenduo State Key Laboratory of Rapidly Solidified Non-Equilibrium Alloys,institute of Metal Research,academia sinica,Shenyang,chinaWU Yukun PENG Yingguo Laboratory of atomic Imaging of Solids,institute of Metal Research,academia sinica,Shenyang,china Associate Professor,institute of Metal Research,academia sinica,Shenyang 110015,china

The crystal habit,crystalline structure,surface condition and composition of the ultrafine Al particles prepared by inert gas evaporation method were studied in detail by means of high resolution transmission electron microscope,X-ray diffraction and X-ray photo-electron *** results indicate that the ultrafine Al particles prepared in high pure inert gas are of clear crystal habits,single crystal in a large majority and fcc crystalline structure with a_0=0.405 *** is also found on the surface of the Al particles that there is a layer of amor- phous Al_2O_3 with 2 nm average thickness,which could protect the particles against oxidizing ***,the ultrafine Al particles prepared by the inert gas evaporation method are very stable in atmosphere.

关键词： ultrafine Al particle structure surface condition amorphous alumina

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