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Efficient expression of codon-adapted human acetaldehyde dehydrogenase 2 cDNA with 6×His tag in Pichia pastoris

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science China(Life sciences) 2009年第10期52卷 935-941页

作者： ZHAO YuFeng1,2, LEI MingKe2, WU YuanXin2, ZHANG ZiSheng3.& WANG CunWen2 1 State key Laboratory of Agricultural Microbiology, College of Life science and technology, Huazhong Agriculture university, Wuhan 43.070, China 2 Key Laboratory for Green {3. Processes of the Ministry of Education, Hubei Key Lab of Novel Reactor & Green {3. technology, school of {3. Engineering and Pharmacy, Wuhan Institute of technology, Wuhan 43.074, China 3.department of {3. Engineering, university of Ottawa, Ottawa, Canada K1N 6N5 State key Laboratory of Agricultural Microbiology College of Life Science and Technology Huazhong Agriculture University Wuhan China Key Laboratory for Green chemical Processes of the Ministry of Education Hubei Key Lab of Novel Reactor & Green Chemical Technology School of Chemical Engineering and Pharmacy Wuhan Institute of Technology Wuhan China department of chemical Engineering University of Ottawa Ottawa Canada

Human mitochondrial acetaldehyde dehydrogenase 2 (ALDH2) catalyzes the oxidation of acetaldehyde to acetic acid. Therefore, ALDH2 has therapeutic potential in detoxification of acetaldehyde. Further-more, ALDH2 catalyzes nitroglycerin to nitrate and 1, 2-glyceryldinitrate during therapy for angina pectoris, myocardial infarction, and heart failure. Large quantities of ALDH2 will be needed for potential clinical practice. In this study, Pichia pastoris was used as a platform for expression of human ALDH2. Based on the ALDH2*1 cDNA sequence, we designed ALDH2 cDNA by choosing the P. pastoris preferred codons and by decreasing the G + C content level. The sequence was synthesized using the overlap extension PCR method. The cDNA and 6×His tags were subcloned into the plasmid pPIC9K. The recombinant protein was expressed in P. pastoris GS115 and purified using Ni2+-Sepharose affinity chromatography. The amount of secreted protein in the culture was 80 mg/L in shake-flask cultivation and 260 mg/L in high-density bioreactor fermentation. Secreted ALDH2 was easily purified from the culture supernatant by using Ni2+-Sepharose affinity chromatography. After purification of the fermentation supernatant, the enzyme had a specific activity of 1.2 U/mg protein. The yield was about 16 mg/L in a shake flask culture of P. pastoris GS115 which contained the original human ALDH2*1 cDNA.

关键词： acetaldehyde dehydrogenase codon optimization overlap extension PCR Pichia pastoris.

Magnetic properties and structure of very thin permalloy films

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Journal of university of science and technology Beijing 2004年第3期11卷 225-229页

作者： Guanghua Yu Haifeng Li Tao Yang Fengwu Zhu Materials science and Engineering school, university of science and technology Beijing, Beijing 100083. China Mat. Sci. and Eng. Sch. Univ. of Sci. and Technol. Beijing Beijing 100083 China

In order to study the magnetic properties and structure of very thinpermalloy films, Ni_(81)Fe_(19) films of 12 nm in thickness were prepared by different instrumentsat an ultrahigh base vacuum and a lower base vacuum. The anisotropic magnetoresistance coefficients(ΔR/R) of Ni_(81)Fe_(19) (12 nm) films reached 1.6 % and 0.6 %, and the coercivities were 127 and3.4 A/m, respectively. X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD) were usedto study the structure and surface chemical state. The experimental results show that the filmsprepared at the ultrahigh base vacuum have a smoother surface, a bigger grain size and a denserstructure with fewer defects than those prepared at the lower base vacuum.

关键词： NiFe film anisotropic magnetoresistance (AMR) coercivity structure

Determination of the Thermal Expansion Coefficient of Concrete at Early Ages by Using Temperature-stress Testing Machine

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Journal of Wuhan university of technology(Materials science) 2006年第4期21卷 146-149页

作者：霍凯成 Hubei Key Laboratory of Roadway Bridge & Structure Engineering Wuhan University of TechnologyWuhan 430070China

By using the uptodate temperatuer-stress testing machine, the thermal expansion coefficient of concrete at early ages was studied and indicative conclusions were achieved ： temperature rising due to hydration heat is not directly correlated with cracking, but the temperature and stress evolation process should be taken into consideration in the same time. Proper chemical admixtures and mineral cornpasitions can improve the mechanical properties of concrete such as thermal expansion coefficient, which is very indicative in practice.

关键词： concrete coefficient of thermal expansion temperature-stress test

Topological chirality and achirality of the closed circular DNAs

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Chinese science Bulletin 1997年第20期42卷 1705-1708页

作者： QIU Wenyuan and XIN Houwen1. department of chemical Physics, university of {3. and technology of China, Hefei 23.026, China 2. department of Chemistry, Lanzhou university, Lanzhou 73.000, China department of chemical Physics University of Science and Technology of China Hefei China department of Chemistry Lanzhou University I anzhou China

THE study of the relations between the topological structure and its function is one of the focus-es in modern chemistry and life science. In this note we set up a topological model to de-scribe the ccDNAs on the basis of Seifert construction in knot theory. Our model for theccDNAs helps to determine whether a structure is topologically chiral or achiral. This is one ofthe fundamental biological problems.

关键词： DNA topology knot theory topologiesl chirality topological achirality.

Adsorption and Reaction of CO on Mo(100)-c(2×2)-N Surface Studied by HREELS

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Chinese chemical Letters 2000年第3期11卷 275-278页

作者： Jun Fa ZHU.,ian Chang GUO, Run Sheng ZHAI, Xin He BAO, Shu Xian ZHUANG ( National Synchrotron Radiation Laboratory, university of science and technology of China, Hefei 23.029 {3. of chemical Physics. university of science and technology of China Natl. Synchrt. Radiation Laboratory Univ. of Sci. and Technol. of China Hefei 230029 China State Key Laboratory of Catalysis Dalian Institute of Chemical Physics Chinese Academy of Sciences Dalian 116023 China department of chemical Physics Univ. of Sci. and Technol. of China Hefei 230026 China

High resolution electron energy loss spectroscopy (HREELS) has been used to investigate the adsorption and reaction of CO on the Mo(100)-c(2×2)N surface. CO directly adsorbed on the N atoms from the c(2×2) layer to form isocyanate (NCO) surface species was found in addition to CO adsorbed on the molybdenum atoms at 120 K. indicating that both Mo and N atoms of the Mo(100)-c(2×2)-N surface are of high reactivities for CO adsorption.

关键词： HREELS adsorption reaction Mo(100)-c(2×2)-N CO.

Atom Transfer Radical Polymerization of Methyl Methacrylate with α,α-Dichlorotoluene or α,α,α-Trichlorotoluene as Initiator

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Chinese chemical Letters 1999年第7期10卷 611-614页

作者： Zhi Feng FU Yan SHI Ming Zhi HUANG Shu Ke JIAO(department of Polymer science. Beijing university of {3. technology. Beijing 100029) department of Polymer science Beijing Univ. of Chemical Technology Beijing 100029 China

The atom transfer radical polymerization (ATRP) of methyl methacrylate using α.α dichlorotoluene or α.α.α-trichlorotoluene as the initiator and CuCl/2.2'-bipyridine complex as the catalyst was investigated. α,α-Dichlorotoluene gave good control of molecular weight with high initiation efficiency and low polydispersity. While α.α.α-trichlorotoluene gave very slow polymerization rate. which could be improved by the addition of Cu (0) to the system.

关键词： atom transfer radical polymerization (ATRP),methyl methacrylate initiator

COMPUTER OPTIMIZATION OF DENSITY AND VISCOSITY FOR BINARY METALLIC MELTS

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中国有色金属学会会刊：英文版 1995年第2期5卷 30-33页

作者： Zhang,Jiayun Zhou, Tuping Feng, Xueliang (department of Physical Chemistry,university of science and {3. Beijing, Beijing 100083. Univ of science and technology Beijing Beijing China

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关键词： metallic melts viscosity computer optimization

PRECIPITATION AND MICROSTRUCTURE OF Cr MODIFIED Al_3.i

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Acta Metallurgica Sinica(English Letters) 2001年第1期14卷 13-20页

作者： W.H. Tian and M. Nemoto (department of Materials Physics and Chemistry, university of science and {3. Beijing, Beijing 100083. China Sasebo National College of {3., Okishin 1-1, Sasebo 857-1193. japan) Dept. of Mat. Phys. Univ. of Sci. and Technol. Beijing Beijing 100083 China

The microstructures of Cr modified Al3.i containing Al2Ti and L10-AlTi precipitates have been investigated in terms of transmission electron microscopy(TEM). Fine precipitation of Al2Ti (Ga2Hf type structure) and Ll0-AlTi(Cr) occurs in Ll2-Al3.i(Cr) by aging around 973.. The aging behavior was investigated by microhardness measurements. TEM observations reveal that plate-like Al2Ti precipitates lie on{100} planes of the Ll2-Al3.i(Cr) matrix with the c axis of the tetragonal phase perpendicular to the thin plate. As contrast with Al2Ti precipitates, Ll0-AlTi(Cr) precipitates form thin plate and lie on {100} planes of Ll2-Al3.i(Cr) matrix at the initial aging time and for long time aging the habit plane of the thin plate deviates from {100} plane and finally forms a kinked plate. The coherency stresses across the precipitate/matrix interface are considered to be the main factors controlling the precipitate morphology.

关键词： Age hardening Aluminum compounds Microstructure Precipitation (chemical) Titanium compounds

Integration of chemical product development, process design and operation based on a kilo-plant

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Progress in Natural science:Materials International 2006年第6期16卷 600-606页

作者： QIAN Yu, WU Zhihui and JIANG Yanbin (school of chemical Engineering, South China university of {3., Guangzhou 510640, China) school of chemical Engineering South China University of Technology Guangzhou 510640 China

Presented in this paper is an integrated approach of computer-aided product development, process design and operation analysis based on a kilo-plant. The implemented kilo-plant, as a research platform to manufacture product in kilogram-scale, was designed especially for fine and specialty chemicals. The characteristics of product synthesis, process operation and product quality control are investigated coupled with computer-aided monitoring, online modeling, simulation and operation process optimization. In this way, chemical product discovery, process design and operation are integrated in a systematic approach, in the aim to respond to rapid changing marketplace demands to new products.

关键词： integration kilo-plant product development process operation process analysis.