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Dose-dependent effects of lead on cell-cycle arrest, DNA damage, and cyclin D1 expression in primary cultured rat hippocampal neurons

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Neural Regeneration Research 2010年第3期5卷 221-225页

作者： shuang gao Liguang Sun Yuanyuan You China Medical University Shenyang 110001 Liaoning Province China

BACKGROUND： Previous studies have suggested that the hippocampus is one of the neurotoxic target sites for lead. However, the molecular mechanisms of action, including the effect of lead on cell-cycle arrest, remain poorly understood. OBJECTIVE： To investigate the effects of different lead concentrations on cell-cycle arrest, DNA damage, and cyclin D1 expression in primary cultured rat hippocampal neurons. DESIGN, TIME AND SETTING： A randomized, controlled, in vitro experiment was performed at the China Medical University between July 2008 and May 2009. MATERIALS： Antibodies specific to cyclin D1 and actin were synthesized and purified by Santa Cruz Biotechnology, USA. FACStar flow cytometer was purchased from Becton Dickinson, San Jose, California, USA. METHODS： Wistar rat hippocampal neurons were primary cultured for 7 days. Neurons in the control group were treated with 0.01 mol/L phosphate buffered saline. Neurons in the 0.2, 1.0, and 10 umol/L lead acetate groups were subjected to 0.2, 1.0, and 10 umol/L lead acetate. Subsequently hippocampal neurons in each group were cultured for 24 hours. MAIN OUTCOME MEASURES： The effects of lead on cell cycle were measured by flow cytometry, DNA damage was measured using the comet assay, and cyclin D1 expression was measured using Western blot analysis. RESULTS： Treatment of hippocampal neurons with 0.2 umol/L lead acetate did not significantly alter cell cycle phase distribution, i.e., sub-G1, S, G0/G1, G2/M, whereas treatment with 1.0 and 10 umol/L lead acetate significantly increased the percentage of S and sub-G1 phase cells （P 〈 0.05）. Olive tail moment in all lead-treated groups and the percentage of DNA in the tail in 1.0 umol/L and 10 umol/L lead acetate groups were significantly greater compared with the control group （P 〈 0.05）. In addition, the percentage of tail DNA was greater in the 0.2 umol/L lead acetate group compared with the control group （P 〉 0.05）. Following incubation with 0.2, 1.0, and 10 umol/L lead

关键词： lead cell-cycle arrest DNA damage cyclin D1 hippocampal neurons nerve factor neural regeneration

Sharp Chandra View of ROSAT All-Sky Survey Bright Sources I. Improvement of Positional Accuracy

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Research in Astronomy and Astrophysics 2016年第12期16卷 67-74页

作者： shuang gao Song Wang Ji-Feng Liu Department of Astronomy Beijing Normal University Key Laboratory of Optical Astronomy National Astronomical Observatories Chinese Academy of Sciences College of Astronomy and Space Sciences University of Chinese Academy of Sciences

The ROSAT All-Sky Survey （RASS） represents one of the most complete and sensitive soft X- ray all-sky surveys to date. However, the deficient positional accuracy of the RASS Bright Source Catalog （BSC） and subsequent lack of firm optical identifications affect multi-wavelength studies of X-ray sources. The widely used positional errors σpos based on the Tycho Reference Catalog （Tycho-1） have previously been applied for identifying objects in the optical band. The considerably sharper Chandra view covers a fraction of RASS sources, whose ~rpos could be improved by utilizing the sub-arcsec positional accuracy of Chandra observations. We cross-match X-ray objects between the BSC and Chandra sources extracted from the Advanced CCD Imaging Spectrometer （ACIS） archival observations. A combined list of counter- parts （BSCxACIS） with Chandra spatial positions weighted by the X-ray flux of multiple counterparts is employed to evaluate and improve the former identifications of BSC when used with other surveys. Based on these identification evaluations, we suggest that the point-source likeness of BSC sources and INS （iso- lated neutron star） candidates should be carefully reconsidered.

关键词： catalogs -- surveys -- X-rays: general -- X-rays: stars

Spatiotemporal evolution of urban carbon emission performance in China and prediction of future trends

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Journal of Geographical Sciences 2020年第5期30卷 757-774页

作者： WANG Shaojian gao shuang HUANG Yongyuan SHI Chenyi Guangdong Provincial Key Laboratory of Urbanization and Geo-simulation School of Geography and PlanningSun Yat-sen UniversityGuangzhou 510275China College of Urban and Environmental Sciences Peking UniversityBeijing 100871China

Climate change resulting from CO_2 emissions has become an important global environmental issue in recent *** carbon emission performance is one way to reduce carbon *** carbon emission performance has been discussed at the national and industrial levels,city-level studies are lacking due to the limited availability of statistics on energy *** this study,based on city-level remote sensing data on carbon emissions in China from 1992–2013,we used the slacks-based measure of super-efficiency to evaluate urban carbon emission *** traditional Markov probability transfer matrix and spatial Markov probability transfer matrix were constructed to explore the spatiotemporal evolution of urban carbon emission performance in China for the first time and predict long-term trends in carbon emission *** results show that urban carbon emission performance in China steadily increased during the study period with some ***,the overall level of carbon emission performance remains low,indicating great potential for improvements in energy conservation and emission *** spatial pattern of urban carbon emission performance in China can be described as"high in the south and low in the north,"and significant differences in carbon emission performance were found between *** spatial Markov probabilistic transfer matrix results indicate that the transfer of carbon emission performance in Chinese cities is stable,resulting in a"club convergence"***,neighborhood backgrounds play an important role in the transfer between carbon emission performance *** on the prediction of long-term trends in carbon emission performance,carbon emission performance is expected to improve gradually over ***,China should continue to strengthen research and development aimed at improving urban carbon emission performance and achieving the national energy conservation and emission reducti

关键词： urban carbon emission performance super-efficiency SBM model spatial Markov chain spatiotemporal patterns trend prediction China

Microstructural evolution and stress state related to mechanical properties of electron beam melted Ti-6Al-4V alloy modified by laser shock peening

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Journal of Materials Science & Technology 2020年第15期47卷 153-161页

作者： Liang Lan Xinyuan Jin shuang gao Bo He Yonghua Rong Research Center of High-temperature Alloy Precision Forming School of Material EngineeringShanghai University of Engineering ScienceShanghai 201620China School of Materials Science and Engineering Shanghai Jiao Tong UniversityShanghai 200240China

This work characterizes microstructural evolutions of electron beam melted(EBM) Ti-6 Al-4 V alloy modified via laser shock peening(LSP).The depth stress distribution and tensile properties of EBM Ti-6 Al-4 V alloy were measured before and after *** results indicate that microstructure consists of β phase with 7.2%±0.4% vol.% and balance α lamellar in EBM sample,and the α lamella was refined into nano-equiaxed grains and submicro-equiaxed grains after *** dominant refinement mechanism is revealed during *** faults were found in the LSP-treated sample,and their corresponding planes were determined as(0001) basal plane,(1010) prismatic plane,and(1011) pyramidal plane obtained by high resolution transmission electron *** subgrains and high-angle grains formed during dynamic recrystallization were identified by selected area electron diffraction *** LSP treatment produces a significantly residual compressive stress approximately-380 MPa with the depth of compressive stress layer reaching 450 μ*** and elongation of the EBM sample were significantly increased after *** strength and ductility enhancements are attributed to compre s sive stress,grain refinement and grain gradient distribution of α phase.

关键词： Electron beam melting Ti-6Al-4V alloy Laser shock peening Microstructural evolution Stress state Mechanical properties

Hydrous cerium oxides coated glass fiber for efficient and long-lasting arsenic removal from drinking water

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Journal of Advanced Ceramics 2021年第2期10卷 247-257页

作者： Ronghui Li Weiyi Yang shuang gao Jianku Shang Qi Li School of Gemology and Material Technology Hebei GEO UniversityShijiazhuang050031China Key Laboratory of Advanced Technologies of Materials(Ministry of Education) School of Materials Science and EngineeringSouthwest Jiaotong UniversityChengdu610031China Shenyang National Laboratory for Materials Science Institute of Metal ResearchChinese Academy of SciencesShenyang110016China

A novel arsenic adsorbent with hydrous cerium oxides coated on glass fiber cloth(HCO/GFC)was *** HCO/GFC adsorbents were rolled into a cartridge for arsenic removal *** to the large pores between the glass fibers,the arsenic polluted water can flow through *** arsenic removal performance was evaluated by testing the equilibrium adsorption isotherm,adsorption kinetics,and packed-bed *** pH effects on arsenic removal were *** test results show that HCO/GFC filter has high As(Ⅴ)and As(Ⅲ)removal capacity even at low equilibrium *** more toxic As(Ⅲ)in water can be easily removed within a wide range of solution p H without *** contaminated ground-water from Yangzong Lake(China)was used in the column *** typical breakthrough conditions(the empty bed contact time,EBCT=2 min),arsenic researched breakthrough at over 24,000 bed volumes(World Health Organization(WHO)suggested that the maximum contaminant level(MCL)for arsenic in drinking water is 10 mg/L).The Ce content in the treated water was lower than 5 ppb during the column test,which showed that cerium did not leach from the HCO/GFC material into the treated *** relationship between dosage of adsorbents and the adsorption kinetic model was also clarified,which suggested that the pseudo second order model could fit the kinetic experimental data better when the adsorbent loading was relatively low,and the pseudo first order model could fit the kinetic experimental data better when the adsorbent loading amount was relatively high.

关键词： hydrous cerium oxide(HCO) glass fiber cloth(GFC) column test adsorption kinetics adsorption mechanism

Influence of multiple laser shock peening treatments on the microstructure and mechanical properties of Ti-6Al-4V alloy fabricated by electron beam melting

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International Journal of Minerals,Metallurgy and Materials 2022年第9期29卷 1780-1787页

作者： Liang Lan Ruyi Xin Xinyuan Jin shuang gao Bo He School of Material Engineering Shanghai University of Engineering ScienceShanghai 201620China Research Center of High-temperature Alloy Precision Forming Shanghai University of Engineering ScienceShanghai 201620China

Laser shock peening(LSP)is an attractive post-processing method to tailor surface microstructure and enhance mechanical performances of additive manufactured(AM)*** effects of multiple LSP treatments on the microstructure and mechanical properties of Ti-6Al-4V part produced by electron beam melting(EBM),as a mature AM process,were studied in this ***,surface topography,residual stress,and tensile performance of EBM-manufactured Ti-6Al-4V specimens were systematically analyzed subjected to different LSP *** distribution of porosities in EBM sample was assessed via X-ray computed *** results showed that EBM samples with two LSP treatments possessed a lower porosity value of 0.05%compared to the value of 0.08%for the untreated *** strength of EBM samples with two LSP treatments was remarkably raised by 12%as compared with the as-built *** grains ofαphase were refined in near-surface layer,and a dramatic increase in the depth and magnitude of compressive residual stress(CRS)was achieved in EBM sample with multiple LSP *** grain refinement ofαphase and CRS with larger depth were responsible for the strength enhancement of EBM samples with two LSP treatments.

关键词： additive manufacturing laser shock peening electron beam melting residual stress Ti-6Al-4V alloy mechanical properties

Possible Streams of the Globular Clusters in the Galaxy

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Chinese Journal of Astronomy and Astrophysics 2007年第1期7卷 111-119页

作者： shuang gao Bi-Wei Jiang Yong-Heng Zhao Department of Astronomy Beijing Normal University Beijing 100875 National Astronomical Observatories Chinese Academy of Sciences Beijing 100012

We aim to retrieve ghost streams under the assumption that all the globular clusters in our Galaxy were formed in very early merge events. Our results are based on two speculations： that the specific energy and angular momentum of the globular clusters after merge are not changed in the course of evolution and that the globular clusters with a common origin would stay in the same orbit plane as the parent galaxy. After taking into account the apogalacticum distance of the orbits, we suggest with some Confidence five possible streams. The number of streams is consistent with the previous results. Three of the four well established members of the Sagittadus stream were found to be in one of our streams. Several other globular clusters in our result were also thought to come from accretion by previous researchers. The orbital parameters of the streams are derived, which provide a way to test whether these streams are true with the help of more accurate measurement of proper motions of the globular clusters.

关键词： globular clusters general-Galaxy formation-Galaxy halo

Fabrication of ultrafine ZnFe2O4 nanoparticles for efficient photocatalytic reduction CO2 under visible light illumination

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Journal of Materials Science & Technology 2018年第12期34卷 2331-2336页

作者： Jun xiao Weiyi Yang shuang gao Caixia Sun Qi Li Environment Functional Materials Division Shenyang National Laboratory for Materials ScienceInstitute of Metal ResearchChinese Academy of SciencesShenyong 110016China University ofChineseAcademy of Sciences Beijing 100049China Division of Energy and Environment Graduate School of ShenzhenTsinghua UniversityShenzhen 518055China Key Laboratory of New Metallic Functional Materials and Advanced Surface Engineering in Universities of Shandong Qingdao Binhai UniversityQingdao 266555China School of Mechanical and Electronic Engineering Qingdao Binhai UniversityQingdao 266555China

A one-pot, solvent-thermal process was used to create the ultrafine ZnFe2O4nanoparticles *** the solvent-thermal process, the in situ self-forming NaCl not only served as a "cage" to confine the ion diffusion, but also acted as a microreactor for nanocrystallite growth. An average particle size of ～10 nm and a high-specific surface area of～112.9 m2/g were observed for the ultrafine ZnFe2O4nanoparticles Owing to the synergistic effect of ultrafine particle size, the full utilization of the visible light region and high conduction band(CB) position, ultrafine ZnFe2O4photocatalyst displayed an efficient photocatalytic CO2reduction under visible light illumination. Besides, the ultrafine ZnFe2O4photocatalyst showed high production selectivity for CH3CHO and C2H5OH generation in aqueous CO2/NaHCO3solution. This work may provide a new idea for the synthesis of new high-efficiency photocatalysts.

关键词： Ultrafine nanoparticles Photocatalytic CO_2 reduction Visible light ZnFe_2O_4 photocatalyst In situ self-formed "cage"

Intergrowth of C phase within μ phase in a Re-containing Ni-base single crystal superalloy

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Journal of Materials Science & Technology 2018年第5期34卷 806-810页

作者： shuang gao Yizhou Zhou Zhi-Quan Liu Tao Jin Institute of Metal Research Chinese Academy of Sciences Division of Energy and Environment Graduate School at ShenzhenTsinghua University

Precipitation of topologically close-packed phases in a Re-containing Ni-base single crystal superalloy was studied under elevated temperature by in situ transmission electron *** 1150℃,a new intergrowth structure called C phase was found within μ phase with a defined crystallographic orientation *** mapping analysis reveals that C phase has a similar element composition as μ phase,but contains a lower level of Cr,W and *** increasing temperature,the proportion of C phase increases *** 1250℃,C phase becomes the dominant *** is demonstrated that C phase is more thermodynamically stable than μ phase above 11509 that leads to an intergrowth pathway from μ phase to C phase.

关键词： Ni-base superalloy Phase transformation Precipitation