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Progress in Natural Science:Materials International 2009年第5期19卷 563-572页

作者： Longguo Jin, Bo Huang, Hui Li, Jinyuan Liu Laboratory of Molecular Biology and MOE Laboratory of Protein Science, department of biological sciences and biotechnology, tsinghua university, beijing 100084. china [a]Laboratory of Molecular Biology and MOE Laboratory of Protein Science Department of Biological Sciences and Biotechnology Tsinghua University Beijing 100084 China

Plant AP2/EREBP transcription factors play important roles in plant development and in plant responses to biotic and abiotic stresses. A novel gene for ethylene-responsive element binding protein (EREBP), designated GhERF5, which encodes a protein of 255 amino acids, was isolated by RACE-PCR from cotton (Gossypium hirsutum) seedlings. Sequence alignment revealed that GhERF5 contains a typical AP2/ERF domain, and belongs to the B3 subgroup of the ERF subfamily. Particle bombardment assay showed that GhERF5 functions as an in vivo transcription activator in tobacco cells, and it is located in the nuclei of onion epidermis cells. Semi-quantitative RT-PCR revealed that the expression of GhERF5 was highly and rapidly induced when plants were treated with exogenous ethylene, abscisic acid (ABA), salt, cold and drought. Promoter analysis indicated that there are conserved cis-acting elements induced by these stresses in the 50-upstream region of the GhERF5 gene. These results suggest that the GhERF5 gene might play an important role in cotton response to ethylene, ABA and environmental stresses.

关键词： Ethylene-responsive element binding factor (ERF) Abiotic stresses Nuclear localization Transactivation Gossypium hirsutum

Design of policy mechanism to promote cleaner production in china

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Journal of Environmental sciences 2001年第3期13卷 346-350页

作者： ZHANG Tian zhu(department of Environmental Science and Engineering, tsinghua university, beijing 100084. china. department of Environmental Science and Engineering Tsinghua University Beijing 100084 China. zhangtz@***

In order to promote cleaner production in china, a package of policy options was presented based on the identification of the barriers encountered in the CP demonstration project and the effectiveness and feasibility of policy options for the CP implementation were analyzed. Furthermore, the policy mechanism framework was given, which composes of compulsory, economic incentive, social pressure and supportive function. Finally, the implementation strategy of the policy mechanism, in which the emphasis will be changed from compulsory policy options towards economic and social pressure policy options, was proposed.

关键词： cleaner production barrier identification policy mechanism china

SYNTHESIS OF NOVEL SOLUBLE AROMATIC POLYPYROMELLITIMIDE CONTAINING ORDERED 1,2,4-TRIAZINE IN THE MAIN CHAIN

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Chinese Journal of Polymer Science 2002年第3期20卷 219-224页

作者： Xiao-bing Yi Guo-shi Wu Feng-cai Lu department of Chemistry tsinghua university, beijing 100084.china Institute of Chemistry Chinese Academy of sciences, beijing 100080, china Tsing Hua Univ Dept Chem Beijing 100084 Peoples R China Chinese Acad Sci Inst Chem Beijing 100080 Peoples R China

A new heat-resistant, soluble polymer, poly(phenyl-1,2,4-triazine imide), has been prepared via a two-step method of polycondensation of N,N'-bis(4-benzil)pyromellitimide and terephthalamidrazone in cresol, followed by curing at higher temperature. The rigid 1,2,4-triazine group increases the solubility of the polyimide so that the polymer is soluble in cresol, N-methyl-2-pyrrolidone (NMP), trifluoroacetic acid and concentrated sulfuric acid, etc. Thermogravimetric analysis (TGA) indicates that this novel polyimide has good thermal stability with a high decomposition temperature of 447degreesC in air and of 423 degreesC in N-2, It has a tensile strength of 107.4 MI'a with an elongation at break of around 7.6%.

关键词： polyimides N,N '-bis(4-benzil)pyromellitimide rigid-rod group 1,2,4-triazine

Effects of the Biot and the squirt-flow coupling interaction on anisotropic elastic waves

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Chinese Science Bulletin 2000年第23期45卷 2130-2138页

作者： YANG Dinghui & ZHANG Zhongjie department of Mathematical sciences, tsinghua university, beijing 100084. china Institute of Geophysics, Chinese Academy of sciences, beijing 100101, china department of Mathematical sciences Tsinghua University Beijing China Institute of Geophysics Chinese Academy of Sciences Beijing China

Considering the velocity anisotropy of the solid/fluid relative motion and employment of the BISQ theory based on the one-dimensional porous isotropic case, we establish a two-phase anisotropic elastic wave equation to simultaneously include the Biot and the squirt mechanisms in terms of both the basic principles of the fluid’s mass conservation and the elastic-wave dynamical equations in the two-phase anisotropic rock. Numerical results, while the Biot-flow and the squirt-flow effects are simultaneously considered in the transversely isotropic (Tl) poroelastic medium, show that the attenuation of the quasi P-wave and the quasi SV-wave strongly depend on the permeability anisotropy, and the attenuation behavior at low and high frequencies is contrary. Meanwhile, the attenuation and dispersion of the quasi P-wave are also affected seriously by the anisotropic solid/fluid coupling additional density.

关键词： two-phase anisotropy Biot flow squirt-flow elastic wave attenuation and dispersion BISQ model.

Effects of genistein, daidzein and glycitein on the osteogenic and adipogenic differentiation of bone marrow stromal cells and on the adipogenic trans-differentiation of osteoblasts

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Progress in Natural Science:Materials International 2005年第11期15卷 993-999页

作者： LI Xianghui, ZHANG Jinchao, SUI Senfang and YANG Mengsu (State Key Laboratory of Biomembrane, department of biological sciences and biotechnology, tsinghua university, beijing 100084. china department of Chemistry, College of Chemistry & Environmental Science, Hebei university, Baoding 071002, china department of Biology and Chemistry, City university of Hong Kong, Hong Kong, china) State Key Laboratory of Biomembrane Department of Biological Sciences and Biotechnology Tsinghua University Beijing 100084 China. department of Chemistry College of Chemistry & Environmental Science Hebei University Baoding 071002 China. department of Biology and Chemistry City University of Hong Kong Hong Kong China

The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT), alkaline phosphatase (ALP) activity and oil red O assays were used to examine the effects of genistein, daidzein and glycitein on the osteogenic and adipogenic differentiation of primary mouse bone marrow stromal cells (MSCs) and the adipogenic trans-differentiation of primary mouse osteoblasts. The results indicated that daidzein, genistein and glycitein at concentrations from 1×10-8 mol/L to 1×10-5mol/L promoted the proliferation of MSCs and osteoblasts; genistein, daidzein and glycitein promoted osteogenic differentiation and inhibited adipogenic differentiation of MSCs, and inhibited adipocytic transdifferentiation of osteoblasts at appropriate concentrations as 17β-estradiol. It suggests that genistein, daidzein and glycitein regulate a dual differentiational process of MSCs into the osteogenic and adipogenic lineages, and trans-differentiational process of primary osteoblasts into the adipocyte lineages, causing a lineage shift toward osteoblast. Protective effects of them on bone may be mediated by a reversal of adipogenesis which may promote the proliferation, differentiation and mineralization of osteoblasts, and make adipocytes secrete less cytokines which may promote osteoclast formation and activation. In addition, the results also indicated that genistein, daidzein and glycitein may be helpful in preventing the development of steroid induced osteonecrosis.

关键词： genistein daidzein glycitein bone marrow stromal cells osteoblasts osteogenic differentiation adipogenic differentiation adipogenic trans-differentiation.

Crystallization and preliminary X-ray studies of porcine kidney aminoacylase Ⅰ

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Chinese Science Bulletin 1997年第20期42卷 1750-1752页

作者： ZHAOHaiyan, MENGWuyi, LIN Zhengjiong and ZHOU Haimeng1. National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of sciences, beijing 100101, china 2. department of biological Science and biotechnology, tsinghua university, beijing 100084. china National Laboratory of Biomacromolecules Institute of Biophysics Chinese Academy of Sciences Beijing China department of biological Science and biotechnology Tsinghua University Beijing China

AMINOACYLASE Ⅰ（ACY-1）（E. C. 3. 5. 1. 14 ） participated in amino acid metabolism existingin mammalian kidney and microorganisms, and catalyzes reversible hydrolysis of acylaminoacids. ACY-1 consists of 772 amino acids, and the molecular weight is 85 500 daltons. It is adimeric metalloprotein having two Zn2+ in the molecule. The nucleotide and the amino acid se-quence of porcine and human ACY-1 have been determined. The nucleotide sequence and

关键词： aminoacylase I crystallization preliminary crystallography.

Expression of lignin peroxidase H2 from Phanerochaete chrysosporium by multi-copy recombinant Pichia strain

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Journal of Environmental sciences 2009年第2期21卷 218-222页

作者： WANG Wei,WEN Xianghua department of Environmental Science and Engineering,tsinghua university,beijing 100084.china. department of Environmental Science and Engineering Tsinghua University Beijing 100084 China

The lipH2 gene, encoding the expression of lignin peroxidase, was cloned from Phanerochaete chrysosporium BKM-F-1767 and expressed in Pichia pastoris X-33, a yeast. The cDNA of LiPH2 was generated from total RNA extracted from P chrysosporium by PCR with primers that do not contain a P. chrysosporium lignin peroxidase secretion signal. The gene was then successfully inserted into the expression vector pPICZα, and resulted in the recombinant vector pPICZα-lipH2. The transformation was conducted in two ways. One was using the wild Pichia pastoris as the recipients, which results in the recombinant P. pastoris with single or low lipH2 gene copy. The second was using P. pastoris and single or low lipH2 gene copy as the recipients, which results in the recombinant P. pastoris with multi-copies of lipH2 genes. This study firstly expressed the gene lipH2 in P. pastoris and achieved the successful expression of the lipH2 depending upon the generation of a recombinant strain that contained multiple copies. The lignin peroxidase activity reached a maximum of 15 U/L after 12 h induction.

关键词： heterologous expression lignin peroxidase Pichia pastoris

A measure for spatial heterogeneity of vegetation in the Center of Inner Mongolia

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Progress in Natural Science:Materials International 2008年第3期18卷 289-295页

作者： Baimin Songa,b, Daming Huangc,d, Renqing Wanga, Shiyomi Masae d, Fei Xua, Wei Wanga, Gaosheng Zhanga, Xianqiang Zhanga, Jian Qiaoe a College of Life Science, Shandong university, Jinan 250100, china b department of Environmental Science and Engineering, tsinghua university, beijing 100084. china c Institute of Ecology, department of biological sciences and biotechnology, tsinghua university, beijing 100084. china d Faculty of Science, Ibaraki university, Bunkyo 2-1-1, Mito 310-8512, Japan e department of Chemical Engineering, tsinghua university, beijing 100084. china College of Life Science Shandong University Jinan 250100 China department of Environmental Science and Engineering Tsinghua University Beijing 100084 China Institute of Ecology Department of Biological Sciences and Biotechnology Tsinghua University Beijing 100084 China Faculty of Science Ibaraki University Bunkyo 2-1-1 Mito 310-8512 Japan department of Chemical Engineering Tsinghua University Beijing 100084 China

This study surveyed and analyzed the vegetation heterogeneity in the Center of Inner Mongolia (CIM) by a new method based on the beta-binomial distribution for each kind of vegetation. As many as 190 large quadrats of 5 mm 5 mm (representing an area of 50 km 50 km) (referred to as L-quadrats hereafter) were extracted from about an area of 475,000 km2. Each L-quadrat was divided into four small quadrats (S-quadrat) of 2.5 mm 2.5 mm (equivalent to 25 km 25 km) and the frequency of occurrence of each type of vegetation was recorded in each small quadrate. The weighted average heterogeneity from all of the vegetations composing a land- scape provides a measure at landscape level to determine the spatial intricateness of landscape composition. Our results indicated that each vegetation has its own distribution pattern and the degree of heterogeneity is different from one kind of vegetation to the other. The results proved that the beta-binomial distribution can be very useful for analyzing vegetation landscapes.

关键词： Heterogeneity Beta-binomial distribution Frequency Occurrence Inner Mongolia

Continuity in weak topology:higher order linear systems of ODE

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Science china Mathematics 2008年第6期51卷 1036-1058页

作者： ZHANG MeiRong department of Mathematical sciences,Zhou Pei-Yuan Center for Applied Mathematics,tsinghua university,beijing 100084.china department of Mathematical sciences Zhou Pei-Yuan Center for Applied Mathematics Tsinghua University Beijing 100084 China

We will introduce a type of Fredholm operators which are shown to have a certain con- tinuity in weak *** this,we will prove that the fundamental matrix solutions of k-th, k≥2,order linear systems of ordinary differential equations are continuous in coefficient matrixes with weak ***,Floquet multipliers and Lyapunov exponents for periodic systems are continuous in weak ***,for the scalar Hill’s equations,Sturm-Liouville eigenvalues, periodic and anti-periodic eigenvalues,and rotation numbers are all continuous in potentials with weak *** results will lead to many interesting variational problems.

关键词： continuity weak topology Fredholm operator linear system Hill’s equation eigenvalue rotation number Lyapunov exponent 34A30 34L40 37E45 34D08 58C07 46B50

Isochronous Centers and Isochronous Functions

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Acta Mathematicae Applicatae Sinica 2002年第2期18卷 315-324页

作者： Li-jun Yangdepartment of Mathematical sciences of tsinghua university, beijing 100084. china department of Mathematical sciences of tsinghua university Beijing China

We study isochronous centers of two classes of planar systems of ordinary differential equations. For the first class which is the Lienard systems of the form x=y-F(x), y=-g(x) with a center at the origin, we prove that if g is isochronous (see Definition 1.1), then the center is isochronous if and only if F≡0. For the second class which is the Hamiltonian systems of the form i=-g(y), y=f(x) with a center at the origin, we prove that if / or g is isochronous, then the center is isochronous if and only if the other is also isochronous.

关键词： Isochronous center Lienard system monotonicity period function