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Rhodoaggregin : a novel multimeric platelet agonist from the venom of Calloselasma rhodostoma (Malayan Pit Viper)

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华夏医学 2000年第1期13卷 1-7页

作者： Runhua Wang 1, Karen S. C. Thiang 2 and Max C.M.Chung 2, 3 (Bioscience Centre, Department of Biological Sciences 1,Department of Biochemistry 2, Bioprocessing Technology Centre, National University of singapore 3, singapore) Bioscience Centre Department of Biological Sciences Singapore Bioscience Centre Department of Biochemistry Singapore Bioscience Centre Department of Biochemistry Singapore Bioprocessing Technology Centre National University of Singapore Singapore

By means of Superdex 75 gel filtration and Mono Q ion exchange chromatography, we have isolated a novel platelet aggregation inducer, termed rhodoaggregin, from the crude venom of Calloselasma rhodostoma (Malayan pit viper). The native molecular mass of rhodoaggregin (as estimated by gel filtration chromatography) was 66 kDa while its isoelectric point (pI) was determined to be 3.45. Under reducing conditions of SDS PAGE, rhodoaggregin exhibited two distinctive bands with molecular masses of 18 kDa (α subunit) and 15 kDa (β subunit). In the absence of reducing agents, however, two bands were also observed, but with apparent molecular masses of 28 (major) and 52 (minor) kDa, respectively. Furthermore, mass spectrometric analysis also showed that rhodoaggregin had a molecular mass of 30155.39±3.25. These molecular weight data suggest that rhodoaggregin probably exists as a tetrameric structure consisting of two disulfide linked heterodimers. N terminal amino acid sequence analysis showed that the two subunits of rhodoaggregin exhibit a high degree of homology with each other and with those of the C type lectin related proteins (CLPs) from other snake venoms. Functional platelet assays showed that rhodoaggregin induced platelet aggregation in rabbit and human whole blood, platelet rich plasma (PRP) and washed platelets with a lag period and in an all or none manner. The concentration of rhodoaggregin that induced maximal aggregation is estimated at about 0.04 μg/ml (or 0.7 nM). [WT5”HZ]

关键词： a novel platelet aggregation inducer the venom of calloselasma rhodostoma(Malayan pit viper) Molecular analyses gel filtration chromatogrophy,SDS PAGE and RP HPLC

Damage Assessment for Buried Structures Against Internal Blast Load

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Transactions of Tianjin University 2008年第5期14卷 353-357页

作者： MA Guowei HUANG Xin LI Jianchun School of Civil and Environmental Engineering Nanyang Technological University Nanyang Avenue Singapore 639798 Singapore

The soil-structure interaction (SSI) decoupling is applied to simplify buried structure against internal blast load as spring effect. Shear failure, bending failure and combined failure modes are considered based on five transverse velocity profiles for the rigid-plastic structural element. The critical equations for shear and bending failure are derived respectively. Pressureimpulse diagrams are accordingly developed to assess damage of the buried structures against internal blast load. Comparison is done to show influences of soil-structure interaction and shear-to-bending strength ratio of a structural element. A case study is conducted to show the application of damage assessment to a reinforced concrete beam element of buried structure.

关键词： combined failure pressure-impulse diagram buried structure blast load damage assessment

Hardness, Wear Resistance and Fracture Toughness of Cast Hiduminium/Corundum Particulate Composites

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Journal of Materials Science & Technology 1996年第5期12卷 357-360页

作者： K.H.W.Seah(Dept. of Mechanical Engineering, National University of singapore, 10 Kent Ridge Crescent, singapore 119260)R.S.Kulkarni and S.C.Sharma (Dept. of Mechanical Engineering, R.V.College of Engineering, Mysore Road, Bangalore-560-059, Karnataka, Ind RV COLL ENGN DEPT ENGN MECHBANGALORE 560059KARNATAKAINDIA SJCE DEPT ENGN MECHMYSOREKARNATAKAINDIA

This paper reports some results obtained in an investigation to see how increasing the corundum dispersoid content from 0% to 7% in a matrix of as-cast and wrought hiduminium alloy affects the hardness. wear resistance and fracture toughness of the composite. The results show that as the corundum content is increased, the hardness and the wear resistance increase remarkably,whereas the fracture toughness drops significantly. It was found that Just a minute amount of corundum is sufficient to cause a fairly large change in these mechanical properties. The hardness of the material is also affected signifIcantly by the aging time. Moreover, if other factors are kept constant, hot extrusion improves both its hardness and its wear resistance. whereas the fracture toughness is decreased

关键词： Wear Resistance and Fracture Toughness of Cast Hiduminium/Corundum Particulate Composites Book Cast Hardness

A fast SVM training algorithm based on the set segmentation and k-means clustering

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Progress in Natural Science:Materials International 2003年第10期 30-35页

作者： YANG Xiaowei 1,2 , LIN Daying 1, HAO Zhifeng 1, LIANG Yanchun 3*, LIU Guirong 2 and HAN Xu 2(1. Department of Applied Mathematics, South China University of Technology, Guangzhou 510640, China 2. Centre for ACES, Department of Mechanical Engineering, National University of singapore, 119260, singapore 3. College of Computer Science and Technology, Jilin University, Changchun 130012, China) Department of Applied Mathematics，South China University of Technology，Guangzhou 510640，China Centre for ACES，Department of Mechanical Engineering，National University of singapore，119260，singapore Department of Applied Mathematics，South China University of Technology，Guangzhou 510640，China College of Computer Science and Technology，Jilin University，Changchun 130012，China Centre for ACES，Department of Mechanical Engineering，National University of singapore，119260，singapore

At present, studies on training algorithms for support vector machines (SVM) are important issues in the field of machine learning. It is a challenging task to improve the efficiency of the algorithm without reducing the generalization performance of SVM. To face this challenge, a new SVM training algorithm based on the set segmentation and k means clustering is presented in this paper. The new idea is to divide all the original training data into many subsets, followed by clustering each subset using k means clustering and finally train SVM using the new data set obtained from clustering centroids. Considering that the decomposition algorithm such as SVM light is one of the major methods for solving support vector machines, the SVM light is used in our experiments. Simulations on different types of problems show that the proposed method can solve efficiently not only large linear classification problems but also large nonlinear ones.

关键词： support vector machines set segmentation k means clustering.

CHARACTERIZATION OF MIXED GAS PERMEATION THROUGH HOLLOW FIBERS

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化工学报 2000年第S1期51卷 74-78页

作者： Wang R. Liu S.L. and cao Y.M. (Environmental Technology Institute, singapore, 18 Nanyang Drive, 637723) (Institute of Materials Research & Engineering, 3 Research Link singapore, 117602)

We have studied the mixed gas permeation in hollow fiber membrane modules using two approaches: namely, the co- current plug flow model and the complete mixing model with the combination of experimental data. Elucidation was made to determine the permeance of CO2 and CH4 and the selectivity of CO2/CH4 in a polyimide hollow fiber membrane permeator It is found that the intrinsic gas separation properties of hollow fibers for mixed gases can be accurately determined based on (1) the cocurrent plug now model, and (2) the complete mixing model with the assumption of averaged retentate concentration of the feed and the retentate outlet.

关键词： permeation mixture gas hollow fiber membranes characterization

Solving constrained traveling salesman problems by genetic algorithms

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Progress in Natural Science:Materials International 2004年第7期 79-85页

作者： WU Chunguo 1,2, LIANG Yanchun 1,2*, LEE Heowpueh 2, LU Chun 2 and LIN Wuzhong 2(1. College of Computer Science and Technology, Jilin University Key Laboratory for Symbol Computation and Knowledge Engineering, Ministry of Education of China, Changchun 130012, China 2. Institute of High Performance Computing, singapore 117528, singapore) College of Computer Science and Technology，Jilin University Key Laboratory for Symbol Computation and Knowledge Engineering，Ministry of Education of China，Changchun 130012，China Institute of High Performance Computing，singapore 117528，singapore Institute of High Performance Computing，singapore 117528，singapore

Three kinds of constrained traveling salesman problems (TSP) arising from application problems, namely the open route TSP, the end-fixed TSP, and the path-constrained TSP, are proposed. The corresponding approaches based on modified genetic algorithms (GA) for solving these constrained TSPs are presented. Numerical experiments demonstrate that the algorithm for the open route TSP shows its advantages when the open route is required, the algorithm for the end-fixed TSP can deal with route optimization with constraint of fixed ends effectively, and the algorithm for the path-constraint could benefit the traffic problems where some cities cannot be visited from each other.

关键词： constrained traveling salesman problem genetic algorithm Hamiltonian path open route fixed end.

Advances in modeling of biomolecular interactions

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Acta Pharmacologica Sinica 2004年第1期 3-10页

作者： Cong-zhong CAI, Ze-rong LI, Wan-lu WANG, Yu-zong CHENDepartment of Applied Physics, Chongqing University, Chongqing 400044, China Bioprocessing Technology Centre Department of Computational Science, National University of singapore, singapore 117543

Modeling of molecular interactions is increasingly used in life science research and biotechnology development. Examples are computer aided drug design, prediction of protein interactions with other molecules, and simulation of networks of biomolecules in a particular process in human body. This article reviews recent progress in the related fields and provides a brief overview on the methods used in molecular modeling of biological systems.

关键词： computer simulation computer-aided design ligands protein conformation

Electron Cyclotron Resonance Deposition of Wide Bandgap a-SiC:H Films Using Acetylene under High Hydrogen Dilution

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Journal of Materials Science & Technology 1997年第3期13卷 189-193页

作者： S.F.Yoon and J.Ahn(School of Electrical and Electronic Engineering, Nanyang Technological University Nanyang Avenue, singapore 639798,Rep. of singapore) School of Electrical and Electronic Engineering Nanyang Technological University Nanyang Avenue Singapore 639798 Singapore

The deposition of hydrogenated amorphous silicon carbide (a-SiC.H) films from a mixture of silane, acetylene and hydrogen gas using the electron cyclotron resonance chemical vapour deposition (ECR-CVD) process is reported. The variation of the deposition and film characteristics such as the deposition rate- optical bandgap, photoluminescence and the infra-red (IR) absorption as a function of the hydrogen dilution is investigated. The deposition rate increases to a maximum value of ~25 nm/min at a moderate hydrogen diIution ratio of ~20 [hydrogenflow (sccm)/acetylene+silane flow (sccm)], and decreases in response to a further increase in the hydrogen dilution. There is no strong dependence of the optical bandgap on the hydrogen dilution within the dilution range investigated (10 to 60), and the optical bandgap calculated from the E04 method varied marginally from ~2.85 eV to ~3.17 eV. The room temperaturephotoluminescence (PL) peak energy and intensity shows a prominent shift to a maximum value of ~2.17 eV corresponding to maximum PL intensity at a moderate hydrogen diIution of ~*** PL intensity shows a strong dependence on the hydrogen dilution variation. IR absorption results show that films deposited at higher hydrogen dilution have more Si-C bonding.

关键词： SiC Wide Electron Cyclotron Resonance Deposition of Wide Bandgap a-SiC

MODELLING OF INFINITE PROBE-EXCITED CAVITY-BACKED APERTURE ARRAYS

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MODELLING OF INFINITE PROBE-EXCITED CAVITY-BACKED APERTURE A...