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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,{2., beijing 100084, china. 清华大学北京 100084

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

SOME PROPERTIES OF LSQR FOR LARGE SPARSE LINEAR LEAST SQUARES PROBLEMS

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Journal of Systems science & Complexity 2010年第4期23卷 815-821页

作者： Zhongxiao JIA department of Mathematical sciences,{2. university,beijing 100084,china. department of Mathematical sciences Tsinghua University Beijing China

It is well-known that many Krylov solvers for linear systems,eigenvalue problems,andsingular value decomposition problems have very simple and elegant formulas for residual *** not only allow us to further understand the methods theoretically but also can be usedas cheap stopping criteria without forming approximate solutions and residuals at each step beforeconvergence takes *** for large sparse linear least squares problems is based on the Lanczosbidiagonalization process and is a Krylov ***,there has not yet been an analogouslyelegant formula for residual *** paper derives such kind of *** addition,the authorgets some other properties of LSQR and its mathematically equivalent CGLS.

关键词： CGLS krylov subspace lanczos bidiagonalization least squares lsqr normal equations.

Cloning and characterization of cotton heteromeric acetyl-CoA carboxylase genes

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Progress in Natural science:Materials International 2007年第12期17卷 1412-1418页

作者： Qiao Zhixin and Liu Jinyuan(Laboratory of Molecular Biology and Protein science Laboratory of the Ministry of Education, department of {2. sciences and biotechnology, tsinghua university, beijing 100084, china) Laboratory of Molecular Biology and Protein science Department of Biological Sciences and Biotechnology Tsinghua University Beijing 100084 China

Heteromeric acetyl-coenzyme A (CoA) carboxylase (ACCase) catalyzes the formation of malonyl-CoA from acetyl-CoA. It plays an essential role in fatty acid synthesis in prokaryotes and most of plants. The heteromeric ACCase is composed of four subunits: biotin carboxylase (BC), biotin carboxyl carrier protein (BCCP), and α- and β-subunits of carboxyltransferase (α- and β-CT). In this study, we cloned five novel genes encoding the subunits of heteromeric ACCase (one BC, BCCP and β-CT, and two α-CTs) from cotton (Gossypium hirsutum cv. zhongmian 35) by RACE-PCR. The deduced amino acid sequence of these cDNAs shares high similarity with other reported heteromeric ACCase subunits. The phylogenetic analysis indicated that the different subunits of heteromeric ACCase were grouped in a similar pattern. Southern blot analysis revealed the milti-copy patterns of these heteromeric ACCase genes in cotton genome. Semi-quantitative RT-PCR demonstrated that heteromeric ACCase genes were constitutively expressed in all of the cotton tissues, but the transcripts accumulated at a relatively low level in roots. To our knowledge, this is the first report about characterization of the heteromeric ACCase genes in cotton.

关键词： heteromeric ACCase cotton gene cloning fatty acid synthesis.

Assembly and structure of protein phosphatase 2.

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science china(Life sciences) 2009年第2期52卷 135-146页

作者： SHI Yi Gong Center for Structural Biology, department of biological {2.s and biotechnology, and School of Medicine, tsinghua university, beijing 100084, china Center for Structural Biology Department of Biological Sciences and Biotechnology and School of Medicine Tsinghua University Beijing China

Protein phosphatase 2. (PP2.) represents a conserved family of important protein serine/threonine phosphatases in species ranging from yeast to human. The PP2. core enzyme comprises a scaffold subunit and a catalytic subunit. The heterotrimeric PP2. holoenzyme consists of the core enzyme and a variable regulatory subunit. The catalytic subunit of PP2. is subject to reversible methylation, medi-ated by two conserved enzymes. Both the PP2. core and holoenzymes are regulated through interac-tion with a large number of cellular cofactors. Recent biochemical and structural investigation reveals critical insights into the assembly and function of the PP2. core enzyme as well as two families of holoenzyme. This review focuses on the molecular mechanisms revealed by these latest advances.

关键词： protein phosphorylation dephosphorylation PP2. structure mechanism

Electrophysiological research of synapse formation from beginning to maturity

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Chinese science Bulletin 1998年第1期43卷 55-59页

作者： XIE Zuoping and ZHENG Yufang State Key Laboratory of Biomembrane and Membrane Biotechnique department of biological {2.s and biotechnology, tsinghua university, beijing 100084, china State Key Laboratory of Biomembrane and Membrane Biotechnique Tsinghua University Beijing China department of biological {2.s and biotechnology Tsinghua University Beijing China

The development of synapses is an important question in neurobiology. We employ patchclamp technique to record MEPCs and EPCs of myoballs in Xenopus cell culture. The rate of EPC/MEPC is related with synapses maturation. Accordingly, we define the mature synapses as those whose rate of presynaptic membrane’s EPC to MEPC is more than 8. The process of maturation needs about 2.5 h after neurites contact with myoballs. We divide the development of synapses into three stages: young, developing and mature. The neurotransmitters stack gradually and increase by hundreds of times along with young synapses growing into maturity. So the process of synapses maturation should include presynaptic membrane specialization, postsynaptic membrane specialization and neurotransmitters stack.

关键词： definition of mature synapse α latrotoxin (α LTX) neurotransmitter stack.

Molecular cloning and characterization of a cotton phosphoenolpyruvate carboxylase gene

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Progress in Natural science:Materials International 2008年第5期18卷 539-545页

作者： Zhixin Qiao, Jin-Yuan Liu Laboratory of Molecular Biology and Protein science Laboratory of the Ministry of Education, department of {2. sciences and biotechnology, tsinghua university, beijing 100084, china Laboratory of Molecular Biology and Protein science Laboratory of the Ministry of Education Department of Biological Sciences and Biotechnology Tsinghua University Beijing 100084 China

Phosphoenolpyruvate carboxylase (PEPC) plays diverse physiological functions during plant development. In this study, a new phos- phoenolpyruvate carboxylase gene GhPEPC2.is isolated from cotton (Gossypium hirsutum cv. zhongmian 35) by RACE-PCR. The cloned cDNA of GhPEPC2.is 3364 bp in length, and has an open reading frame of 2.13 bp, encoding for 971 putative amino acids with a calculated molecular mass of 110.6 kD and pI of 5.56. The deduced amino acid sequence of GhPEPC2.shares high similarity with other reported plant PEPCs. Southern blot analysis indicates that the cotton PEPC exists as a small gene family and the GhPEPC2.might have two copies in the cotton genome. The semi-quantitative RT-PCR reveals that GhPEPC2.constitutively expresses in all the tissues of cot- ton and accumulated highly in roots, owers and embryos but relatively low in stems and bers. In addition, the recombinant GhPEPC2.has been puri ed by expressing it in Escherichia coli and the catalytic properties of it were also investigated. The results showed that GhPEPC2.is a typical C3 PEPC with a higher Km (83.6 lM) and lower Vmax (8.0 lmol min 1 mg 1) compared with the C3 PEPCs pre- viously reported.

关键词： Phosphoenolpyruvate carboxylase Recombinant protein Southern blot Cotton

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,{2. 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

Localization of calmodulin and calmodulin-like protein and their functions in biomineralization in P. fucata

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Progress in Natural science:Materials International 2008年第4期18卷 405-412页

作者： Zi Fang a, Zhenguang Yan a, Shuo Li a, Qin Wang a, Weizhong Cao a, Guangrui Xu a, Xunhao Xiong a, Liping Xie a,b, Rongqing Zhang a,b, a Institute of Marine biotechnology, department of {2. science and biotechnology, tsinghua university, beijing 100084, china b Protein science Laboratory of the Ministry of Education, tsinghua university, beijing 100084, china Institute of Marine biotechnology Department of Biological Science and Biotechnology Tsinghua University Beijing 100084 China Protein science Laboratory of the Ministry of Education Tsinghua University Beijing 100084 China

Calmodulin (CaM) and calmodulin-like protein (CaLP) are two proteins involved in biomineralization. Their localizations in Pinct- ada fucata mantle epithelia were studied by Western blot (WB) analysis of the nuclear/cytosol fraction of primary cultured P. fucata mantle cells and immunogold electron microscopy. The results showed a completely different distribution of these two proteins at the subcellular level. CaM was distributed throughout both the nucleus and cytoplasm of the mantle epithelium but CaLP was distributed only in the cytoplasm. The functions of these two proteins in biomineralization were investigated by shell regeneration. During this pro- cess, the expressions of CaM and CaLP were greatly enhanced in different organelles of the mantle epithelium. Overexpression of these two proteins and a mutant of calmodulin-like protein (M-CaLP) that lacks an extra C-terminal tail in MC3T3-E1 promoted the mRNA expression of osteopontin, a biomineralization marker for osteoblasts. All of the results indicated that CaM and CaLP have completely different distributions in the mantle epithelium and affect the biomineralization process at different levels. The extra C-terminal tail of CaLP is important for its functions in biomineralization in P. fucata.

关键词： Pinctada fucata Calmodulin Calmodulin-like protein Immunogold electron microscopy

An introduction to tsinghua Cloud

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science china(Information sciences) 2010年第7期53卷 1481-1486页

作者： ZHENG WeiMin1,2.1department of Computer science and Technology,{2., beijing 100084, china 2.5} National Laboratory for Information science and Technology, beijing 100084, china department of Computer science and Technology Tsinghua University Beijing China tsinghua National Laboratory for Information science and Technology Beijing China

Cloud computing has become a trend that draws attention from both academia and industry all over the world. This paper unveils details of tsinghua Cloud, a comprehensive solution for cloud computing developed by Tsing... 详细信息

关键词： cloud computing distributed file system virtual computing environment data sharing