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The protection effect of β-CD on DNA damage induced by ultrafine TiO_2

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Science china Chemistry 2007年第2期50卷 272-275页

作者： ZHU RongRong,WANG ShiLong,SUN XiaoYu,ZHANG Rui & YAO SiDe school of life Science and Technology,tongji univer.ity,shanghai 200092,china 1. school of life Science and Technology Tongji University Shanghai 200092 China

Under the photocatalysis of 365 nm ultraviolet radiation,ultrafine TiO2 caused the oxidative damage of Teasy plasmid DNA. The damage was determined by gel-electrophoresis. Then,a different dose of β-CD was added to the reaction,and the damage was restrained. The rate of damage restraining reached 97% when the mass of β-CD was 4 times as that of TiO2. Through UV scan and IR spectroscopy,it was found that the Ti-O of ultrafine TiO2 was bound with -OH of β-CD cavum and the -OH on the surface of ultrafine TiO2 disappeared,so the formation of ?OH was controlled. The ultrafine TiO2 has been widely used,but it was determined to be carcinogenic by some research. The protection effect of β-CD to DNA in the molecular level takes a new look on the surface modification of nano particles to decrease the toxic effect.

关键词： β-CD ultrafine TiO2 plasmid DNA oxide damage bond reaction damage restrain

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 univer.ity, shanghai 200092, china 1. school of life Science and Technology Tongji University Shanghai 200092 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

Fold-Hopf bifurcation in a simplified four-neuron BAM (bidirectional associative memory) neural network with two delays

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Science china(Technological sciences) 2010年第3期53卷 633-644页

作者： GE JuHong & XU Jian school of Aerospace Engineering and Applied Mechanics,tongji univer.ity,shanghai 200092,china 1. school of Aerospace Engineering and Applied Mechanics Tongji University Shanghai 200092 China

The bidirectional associative memory (BAM) neural network with four neurons and two delays is considered in the present paper.A linear stability analysis for the trivial equilibrium is firstly employed to provide a possible critical point at which a zero and a pair of pure imaginary eigenvalues occur in the corresponding characteristic equation.A fold-Hopf bifurcation is proved to happen at this critical point by the nonlinear *** coupling strength and the delay are considered as bifurcation parameters to investigate the dynamical behaviors derived from the fold-Hopf *** dynamical behaviours are qualitatively classified in the neighbourhood of the fold-Hopf bifurcation point by using the center manifold reduction (CMR) together with the normal *** bifurcating periodic solutions are expressed analytically in an approximate *** validity of the results is shown by their consistency with the numerical simulation.

关键词： codimension-two bifurcation time delay solution classification unfolding centre manifold

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 univer.ity,shanghai 200092,china ~3Cellular Morphology Center,Medical school,tongji univer.ity,shanghai 200092,china Institute of Cancer Research Life Science and Technology School Tongji University Shanghai 200092 China Cellular Morphology Center Medical School Tongji University Shanghai 200092 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

NUMERICAL ANALYSIS OF THE 3-D FLOW FIELD OF PRESSURE ATOMIZERS WITH V-SHAPED CUT AT ORIFICE

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Journal of Hydrodynamics 2011年第2期23卷 187-192页

作者： ZHOU Hua school of Aerospace Engineering and Applied Mechanics Tongji University Shanghai 200092 China

Axisymmetric liquid jets have been studied extensively for more than one century, while non-axisymmetric jets are also very common in engineering applications but attract less concern. Based on Eulerian fluid-fluid model in Fluent software, this article analysizes the 3-D flow fields of pressure atomizers with V-shaped cut at orifice, which will result in a non-axisymmetric liquid jet. Flow rate analysis and jet structure analysis are carried out, the results show that the flow rate can be formulated by adding a correction coefficient to the formula of inviscid axisymmetric jets in atomization regime, when the Weber number is low enough to make the flow fall out of atomization regime, and the jet structure together with the flow rate formula will change. Analysis shows that the evolution of the spray and therefore the structure of the liquid jet are affected much by relative velocity and the local volume fraction of liquid phase.

关键词： flow rate fraction distribution gas-liquid interference non-axisymmetric liquid jet pressure atomizer

Diatomaceous silica filter aid filtration for the effective separation of colloidal Cr（OH）＿3 precipitate from tanning wastewater

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Journal of Environmental sciences 1995年第2期7卷 151-156页

作者： Zhao Youcai Xi Diming Chen Shaowei(school of Environrnental Engineering , tongji univer.ity, shanghai 200092 , china)

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关键词： diatornaceous silica filter acid filtration tanning wastewater colloidal Cr(OH)_3 precipitate.

Homogenization-based multi-scale damage theory

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Science china(Physics,Mechanics & Astronomy) 2010年第4期53卷 690-698页

作者： LI Jie 1,2 & REN XiaoDan 1 1 school of Civil Engineering, tongji univer.ity, shanghai 200092, china 2 State Key Laboratory of Disaster Reduction in Civil Engineering, shanghai 200092, china 1. school of Civil Engineering Tongji University Shanghai 200092 China2. State Key Laboratory of Disaster Reduction in Civil Engineering Shanghai 200092 China

The research of modern mechanics reveals that the damage and failure of structures should be considered on different scales. The present paper is dedicated to establishing the multi-scale damage theory for the nonlinear structural analysis. Starting from the asymptotic expansion based homogenization theory, the multi-scale energy integration is proposed to bridge the gap between the micro and macro scales. By recalling the Helmholtz free energy based damage definition, the damage variable is represented by the multi-scale energy integration. Hence the damage evolution could be numerically simulated on the basis of the unit cell analysis rather than the experimental data identification. Finally the framework of the multi-scale damage theory is established by transforming the multi-scale damage evolution into the conventional continuum damage mechanics. The agree- ment between the simulated results and the benchmark results indicates the validity and effectiveness of the proposed theory.

关键词： Multi-scale damage representation asymptotic method constitutive model numerical simulation

Expression of estrogen receptor （ER） -α and -βtranscripts in the neonatal and adult rat cerebral cortex, cerebellum, and olfactory bulb

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Cell Research 2001年第4期11卷 321-324页

作者： GUO XING ZHONG, JUN DA SU, QING WEN SUN, BING HUA JIAO Department of Biochemistry and Molecular Biology, Second Military Medical univer.ity, shanghai 200433 school of life sciences and Medical Engineering, tongji univer.ity, shanghai 200092, china Shangha 1Department of Biochemistry and Molecular Biology Second Military Medical University Shanghai 200433 3shanghai Institute of Physiology Chinese Academy of Sciences Shanghai 200031 China 1Department of Biochemistry and Molecular Biology Second Military Medical University Shanghai 200433 1Department of Biochemistry and Molecular Biology Second Military Medical University Shanghai 200433

In the present study expression of estrogen receptor subtype -α(ERα) and -β (ERβ) in the cerebral cortex, cerebellum, and olfactory bulb was investigated and compared between neonatal (1～3-days-old) and adult (250～350g) rats, using reverse transcription-polymerase chain reaction (RT- PCR). No ERα transcripts were detectable in the adult cerebellum and olfactory bulb, whereas very weak expression of ERα was present in the adult cerebral cortex. No significant difference in ERβ transcripts was detectable between the neonatal and adult rats. While transcripts for both ER subtypes were co-expressed in these brain areas of neonatal rats, although ERα expression was significantly weaker than ERβ. Even in the cerebral cortex known to contain both ER subtypes in adult rats, ERα transcripts in neonatal rats were much higher than in adult. These observations provide evidence for the existence of different expression patterns of ERcα/ERβ transcripts in these three brain areas between the neonatal and adult rats, suggesting that each ER subtype may play a distinct role in the regulation of differentiation, development, and functions of the brain by estrogen.

关键词： Cerebellum cerebral cortex estrogen receptor (ER) olfactory bulb RT-PCR.

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 univer.ity, Zaozhuang 277160, china 2 shanghai Institute of Ceramics, Chinese Academy of sciences, shanghai 200050, china 3 school of life Science and Technology, tongji univer.ity, shanghai 200092, china 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 200092 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