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Impact and mechanism of TiO_2 nanoparticles on DNA synthesis in vitro

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science china Chemistry 2008年第4期51卷 367-372页

作者： LI ShiQiang, ZHU Hong, ZHU RongRong, SUN XiaoYu, YAO SiDe & WANG ShiLong school of life science and technology, tongji university, shanghai 2.0092. china school of life science and technology Tongji University Shanghai China

The impact of TiO2 nanoparticles on DNA synthesis in vitro in the dark and the molecular mechanism of such impact were studied. The impact of TiO2 nanoparticles on DNA synthesis was investigated by adding TiO2 nanoparticles in different sizes and at various concentrations into the polymerase chain reaction (PCR) system. TiO2 nanoparticles were premixed with the DNA polymerase, the primer or the template, respectively and then the supernatant and the precipitation of each mixture were added into the PCR system separately to observe the impact on DNA synthesis. Sequentially the interaction be- tween TiO2 nanoparticles and the DNA polymerase, the primer or the template was further analyzed by using UV-visible spectroscopy and polyacrylamide gel electrophoresis (PAGE). The results suggest that TiO2 nanoparticles inhibit DNA synthesis in the PCR system in the dark more severely than mi- croscale TiO2 particles at the equivalent concentration and the inhibition effect of TiO2 nanoparticles is concentration dependent. The molecular mechanism of such inhibition is that in the dark, TiO2 nanoparticles interact with the DNA polymerase through physical adsorption while TiO2 nanoparticles do with the primer or the template in a chemical adsorption manner. The disfunction levels of the bio-molecules under the impact of TiO2 nanoparticles are in the following order: the primer > the tem- plate > the DNA polymerase.

关键词： TiO2 nanoparticles PCR DNA synthesis molecular mechanism

Protein Secondary Structure Prediction Using Dynamic Programming

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Acta Biochimica et Biophysica Sinica 2005年第3期37卷 167-172页

作者： Jing ZHAO Pei-Ming SONG Qing FANG Jian-Hua LUO school of life science & technology,shanghai Jiaotong university,shanghai 200240,china shanghai Center for Bioinformation and technology,shanghai 200235,china Logistical Engineering university,Chongqing 400016,china school of life science & technology Shanghai Jiaotong UniversityShanghai 200240 China shanghai Center for Bioinformation and technologyshanghai 200235 China Logistical Engineering universityChongqing 400016 China

In the present paper,we describe how a directed graph was constructed and then searched forthe optimum path using a dynamic programming approach,based on the secondary structure propensity ofthe protein short sequence derived from a training data *** protein secondary structure was thus pre-dicted in this *** average three-state accuracy of the algorithm used was 76.70%.

关键词： directed graph dynamic programming approach protein secondary structure

A simple solution route to control synthesis of Fe_3O_4 nanomaterials at low temperature and their magnetic properties

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science china Chemistry 2009年第7期52卷 916-923页

作者： LIU Yi1,2, CHEN Yun1, ZENG YuPing2 & WANG ShiLong3 1 Department of Chemistry and Chemical Engineering, Zaozhuang university, Zaozhuang 277160, china 2 shanghai Institute of Ceramics, Chinese Academy of sciences, shanghai 200050, china 3 school of life science and technology, tongji university, shanghai 2.0092. china Department of Chemistry and Chemical Engineering Zaozhuang University Zaozhuang China shanghai Institute of Ceramics Chinese Academy of Sciences Shanghai China school of life science and technology Tongji University Shanghai China

A series of nanostructured iron compounds including cubic Fe3O4 and orthorhombic FeOOH were synthesized via a facile low temperature (in the range of 60-100℃) solution method. In the whole process, the interaction between FeCl2·4H2O and methenamine (C6H12N4) was carried out through a reflux device under different reaction conditions such as temperature, solvent, and duration. The samples were detected by XRD, TEM, SAED, physical property measurement system, and Mssbauer spectroscopy, separately. The experiments showed that magnetic mixture nanoparticles had flake and rod morphologies, and cubic Fe3O4 took on grain nanostructure. Magnetism measurements indicated that the saturated magnetization of the as-obtained magnetic mixture was lower than that of the cubic magnetite. Mssbauer spectroscopy testified the sample consisting of cubic magnetite rather than γ-Fe2O3. In addition, a possible growth mechanism of cubic magnetic nanoparticles under different conditions was discussed.

关键词： magnetic nanoparticles cubic Fe3O4 oxidation-coprecipitation method reflux magnetic properties at room temperature Mssbauer spectrum

Mechanisms of antiprostate cancer by gum mastic:NF-κB signal as target

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Acta Pharmacologica Sinica 2007年第3期28卷 446-452页

作者： Mei-lan HE~(2,4) Ang LI~2 Chun-su XU~2 Shun-li WANG~3 Meng-jie ZHANG~2 Hua GU~2 Yao-qin YANG~3 Hui-hong TAO~3 ~2Institute of Cancer Research,life science and technology school,tongji university,shanghai 2.0092.china ~3Cellular Morphology Center,Medical school,tongji university,shanghai 2.0092.china Institute of Cancer Research Life Science and Technology School Tongji University Shanghai China Cellular Morphology Center Medical School Tongji University Shanghai China

Aim:To study the effect of gum mastic,a natural resin,on the proliferation ofandrogen-independent prostate cancer PC-3 cells,and further investigate themechanisms involved in this regulatory system,taking nuclear factor κB(NF-κB)signal as the ***:3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazoliumbromide(MTT)assay and a flow cytometer were used to detect the effect of gummastic on the proliferation of PC-3 ***,reporter gene assay,RT-PCR,andWestern blotting were carried out to study the effects of gum mastic on the NF-κBprotein level and the NF-κB signal *** expression of genes involved inthe NF-κB signal pathway,including cyclin D1,inhibitors of κBs(IκBα),andphosphorylated Akt(p-AKT),were *** addition,transient transfectionassays with the 5×NF-κB consensus sequence promoter was also used to test theeffects of gum ***:Gum mastic inhibited PC-3 cell growth and blockedthe PC-3 cell cycle in the G1 *** mastic also suppressed NF-κB activity inthe PC-3 *** expression of cyclin D1,a crucial cell cycle regulator and anNF-κB downstream target gene,was reduced as ***,gum masticdecreased the p-AKT protein level and increased the IκBα protein ***:Gum mastic inhibited the proliferation and blocked the cell cycleprogression in PC-3 cells by suppressing NF-κB activity and the NF-κB signalpathway.

关键词： gum mastic prostate cancer NF-κB signal

EMMA:An Efficient Massive Mapping Algorithm Using Improved Approximate Mapping Filtering

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Acta Biochimica et Biophysica Sinica 2006年第12期38卷 857-864页

作者： Xin ZHANG~1 Zhi-Wei CAO~2 Zhi-Xin LIN~3 Qing-Kang WANG~1* Yi-Xue LI~4 1 Institute of Micro/Nano science and technology,shanghai Jiaotong university,shanghai 200030,china 2 shanghai Center for Bioinformation technology,shanghai 200235,china 3 College of life science and technology,shanghai Jiaotong university,shanghai 200030,china 4 Bioinformation Center of shanghai Institutes for Biological sciences,Chinese Academy of sciences,shanghai 200031,china Institute of Micro/Nano science and technology Shanghai Jiaotong UniversityShanghai 200030 China shanghai Center for Bioinformation technology Shanghai 200235 China College of life science and technology Shanghai Jiaotong UniversityShanghai 200030 China Bioinformation Center of shanghai Institutes for Biological sciences Chinese Academy of SciencesShanghai 200031 China

Efficient massive mapping algorithm (EMMA),an algorithm on efficiently mapping massivecDNAs onto genomic sequences,has recently been *** process of mapping massive cDNAsonto genomic sequences has been improved using more approximate mapping filtering based on an enhancedsuffix array coupled with a pruned fast hash table,algorithms of block alignment extensions,and *** compared with the classical BLAT software in this field,the computing of EMMA ranges fromtwo to forty-one times faster under similar prediction precisions.

关键词： cDNA mapping maximal exact match enhanced suffix array pruned fast hash table extension algorithm

Electrochemical Characteristic of Decarburization Reaction

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International Journal of Minerals,Metallurgy and Materials 1999年第1期13卷 27-30页

作者： Xionggang Lu Fushen Li lifen Li Kouchih Chou (Applied science school, university of science and technology Beijing, Beijing 100083, china)(Material science and Engineering school, shanghai university, shanghai 200072, china) Applied science school University of Science and Technology Beijing Beijing 100083 China Material science and Engineering school Shanghai University Shanghai 200072 China

The electrochemical mechanism of the reaction between Fe-C melts and CaO-SiO2-Al2O3-FeOx slag systems has been carried out. The experimental results suggest that the final content of carbon in melt increases as the partial oxygen pressure of gas decreases no matter whether there is electronic conductor or not. However, the final content of carbon in the system with electronic conductor is much lower than that without electronic conductor. It can be deduced that the transfer ability of oxygen in slag is dominated by electrons. When an electronic conductor exists, an easy pathway for the electrons is provided and the oxygen transfer rate is accelerated.

关键词： melt-slag reaction decarburization electrochemistry electronic conductor

Characteristics of fMRI BOLD signal and its neurophysiological mechanism

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Progress in Natural science:Materials International 2007年第6期17卷 630-638页

作者： Zhao Xiaohu1,2, Wu Yigen3 and Guo Shengli3(1. College of life sciences, Zhejiang university, Hangzhou 310058, china 2. Imaging Department of tongji Hospital of tongji university, shanghai 200065, china 3. College of Mathematics and Physics, Nanjing university of Information science and technology, Nanjing 210044, china) College of life sciences Zhejiang University Hangzhou 310058 China Imaging Department Tongji Hospital Tongji University Shanghai 200065 China College of Mathematics and Physics Nanjing University of Information Science and Technology Nanjing 210044 China

The functional magnetic resonance imaging (fMRI) based on blood oxygen level dependent (BOLD) contrast has emerged as one of the most potent noninvasive tools for mapping brain function and has been widely used to explore physiological, pathological changes and mental activity in the brain. Exploring the nature and property of BOLD signal has recently attracted more attentions. Despite that great progress has been made in investigation of the characteristics and neurophysiological basis, the exact nature of BOLD signal remains unclear. In this paper we discuss the characteristics of BOLD signals, the nonlinear BOLD response to external stimuli and the relation between BOLD signals and neural electrophysiological recordings. Furthermore, we develop our new opinions regarding nonlinear BOLD response and make some perspectives on future study.

关键词： functional magnetic resonance imaging blood oxygen level dependent nonlinear response neural electrophysiological activity.

cDNA cloning,sequence analysis,and recombinant expression of akitonin beta,a C-type lectin-like protein from Agkistrodon acutus

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Acta Pharmacologica Sinica 2004年第3期25卷 118-123页

作者： Xiang-dong ZHA1,2,Jing LIU1,Kang-sen XU3 1 school of life science,university of science and technology,Hefei 230026 school of life science,Anhui university,2 Hefei 230039 National Institute for Control of Pharmaceuticals and Biological Products,Beijing 100050,china 3 school of life science University of Science and Technology Hefei 230026 National Institute for Control of Pharmaceuticals and Biological Products 北京 100050

AIM: To clone the cDNA of a new member of snake venom C-type lectin-like proteins, to study its structure- function relationships and to achieve its recombinant production. METHODS: PCR primers were designed based on the homology and cDNA was amplified by RT-PCR using total RNA from snake venom gland as the template. The PCR products were cloned into the plasmid pGEM-T and sequenced. The deduced protein sequence was analyzed with some bioinformatic programs. A recombinant expression plasmid was constructed using pBAD- TOPO as vector and transformed into *** TOP10 competent cells. RESULTS: A novel cDNA sequence encod- ing akitonin β was found and accepted by GenBank (accession number AF387100). Akitonin β consists of a typical carbohydrate recognition domain (CRD) of C-type lectins, and it is homologous with other snake venom C-type lectin-like proteins. It was predicted to be a platelet antagonist. Upon induction with arabinose rAkitonin β express- ing in E coli was achieved at a high level (superior to 150 mg/L). The recombinant fusion protein exhibited inhibitory activities on rat platelet aggregation in vitro. CONCLUSION: A new member of snake venom C-type lectin-like proteins was discovered and characterized, and an efficient recombinant expression system was estab- lished for its production.

关键词： snake venoms cDNA akitonin C-type lectin-like proteins recombinant proteins structure- activity relationship

Effect of Asymmetry in a Bistable System Subject to Multiplicative Colored Noise

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Communications in Theoretical Physics 2007年第12期48卷 1059-1062页

作者： ZHOU Yu-Rong~(1,2)GUO Feng~3 and PANG Xiao-Feng~1~1 school of life science and technology,university of Electronic science and technology of china,Chengdu 610054,china~2 school of Information and Electric Engineering,Panzhihua university,Panzhihua 617000,china~3 school of Automation Engineering,university of Electronic science and technology of china,Chengdu 610054,china school of life science and technology University of Electronic Science and Technology of China Chengdu 610054 China school of Information and Electric Engineering Panzhihua University Panzhihua 617000 China school of Automation Engineering University of Electronic Science and Technology of China Chengdu 610054 China

By the method of the stochastic energetics,we investigate the stochastic resonance (SR) phenomenon of anoverdamped Brown particle in an asymmetric bistable potential,driven by external periodical signal and *** expressions have been obtained for the quasi-steady-state probability distribution *** is found thatthe input energy (IE) pumped into the system by the external driving shows an SR-like behavior as a function of thenoise strength,whereas the IE turns to be a monotonic function of the correlation time of the *** effect ofpotential asymmetry is also studied on SR and IE.

关键词： asymmetric bistable system stochastic resonance stochastic energetics