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Effects of basic fibroblast growth factor on beta-catenin protein and mRNA expression during the proliferation of endogenous neural stem cells following focal cerebral ischemia

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Neural Regeneration Research 2009年第2期4卷 111-117页

作者： Xuesong Xing Weili Lü liguang sun Department of Biochemistry and Molecular Biology College of Basic Medicine China Medical University Shenyang 110001 Liaoning Province China Department of Anatomy College of Basic Medicine Shenyang Medical College Shenyang 110034 Liaoning Province China

BACKGROUND： The Wnt/β-catenin signaling pathway plays an important role in neural development. ,β-catenin is an important component of the Wnt/β-catenin signaling pathway. The Wnt signaling pathway has been shown to regulate the interaction of neural stem cells with the extracellular matrix. OBJECTIVE： To investigate the effects of basic fibroblast growth factor （bFGF） on β-catenin protein and mRNA expression, and on hippocampal neural stem cell proliferation in a rat model of cerebral ischemia/reperfusion. DESIGN, TIME AND SETTING： A randomized, controlled, neurobiology experiment was performed in Shenyang Medical College between August 2006 and August 2008. MATERIALS： A total of 72 healthy male Wistar rats, aged 3 months, were used in this study. bFGF was provided by Beijing SL Pharmaceutical Co.,Ltd., China. METHODS： Rats were randomly divided into 3 groups： sham-operated, ischemia/reperfusion, and bFGF-treated （n = 24 per group）. Focal cerebral ischemia/reperfusion was induced in rats from the ischemia/reperfusion group and the bFGF-treated group by 2 hour right middle cerebral artery occlusion and 2 hour restoration of blood flow using the suture method. The ischemia/reperfusion and bFGF-treated groups were intraperitoneally administered 500 IU/mL of bFGF, or the same volume of physiological saline, once a day at postoperative days 1 3, and once every 3 days thereafter. Simultaneously, the sham-operated group underwent experimental procedures identical to the ischemia/reperfusion and bFGF-treated groups, with the exception of ischemia/reperfusion induction and drug administration. At 2 hours, 2, 6, 13, and 20 days after ischemiaJreperfusion induction, 50 mg/kg bromodeoxyuridine （BrdU） was administered to each group, twice daily, to label proliferating neural stem cells. MAIN OUTCOME MEASURES： The effects of bFGF on BrdU labeling, and ,8 -catenin mRNA and protein expression, in neural stem cells were examined by immunohistochemistry, Western blot, RT-PCR, and

关键词： basic fibroblast growth factor β-catenin neural stem cell proliferation rats

High resolution oxygen isotope and grayscale records of a medieval fossil giant clam(Tridacna gigas) in the South China Sea: physiological and paleoclimatic implications

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Acta Oceanologica Sinica 2014年第8期33卷 18-25页

作者： YAN Hong WANG Yuhong sun liguang State Key Laboratory of Loess and Quaternary Geology Institute of Earth EnvironmentChinese Academy of Sciences Institute of Polar Environment School of Earth and Space SciencesUniversity of Science and Technology of China Advanced Management Research Center Ningbo University

Mollusks are well known for their detailed recording of paleoenvironmental and paleoclimatic changes in their carbonate shells. In this study, we constructed 18-year blue color intensity and oxygen isotope profiles of a14C dated （AD 990±40） fossil giant clam,Tridacna gigas, from Shidao Island, South China Sea. Theδ18O profile of theT. gigas specimen displayed regular annual cycles and was probably controlled by seasonal variations of the climatic parameters. The blue color intensity profile showed good agreement with theδ18O series, and both had 18 clear annual cycles in accordance with the 18 visually identified annual growth bands. The annual shell growth rate determined from the blue color intensity and oxygen isotope profiles indicated that the annual shell increment of theTridacna specimen was stable after the onset of sexual ma-turity. Spectral analysis of theδ18O and blue color intensity time series suggested that the El Ni？o-Southern Oscillation （ENSO） period observed in the instrumental temperature and precipitation records of the South China Sea during the past 50 years also existed in medieval times. Our results showed that fossil giant clams could provide a good archive of historical intra-seasonal to decadal climate variations.

关键词： Tridacna gigas oxygen isotope blue color intensity Medieval Warm Period sea surface temperature El Ni?o–Southern Oscillation

Millennial mercury records derived from ornithogenic sediment on Dongdao Island,South China Sea

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Journal of Environmental Sciences 2011年第9期23卷 1415-1423页

作者： Hong Yan Yuhong Wang Wenhan Cheng liguang sun Institute of Polar Environment University of Science and Technology of China Hefei 230026 China National Institutes of Health Bethesda MD 20892 USA

Two ornithogenic sediment cores,which have a time span of 1000 years and are influenced by red-footed booby （Sula sula）,were collected from Dongdao Islands,South China *** determined mercury concentrations of the two cores show similar and substantial fluctuations during the past millennium,and the fluctuations are most likely caused by the changes in mercury level of the ocean environment and in anthropogenic Hg *** the past 500 years,the mercury concentration in the red-footed booby excrement has a striking association with global anthropogenic mercury *** mercury concentration increased rapidly after AD 1600 in corresponding to beginning of the unparalleled gold and silver mining in South Central America that left a large volume of anthropogenic mercury *** the Industrial Revolution,the mercury level has increased at a fast pace,very likely caused by modern coal combustion,chlor-alkali and oil refining *** comparison of mercury profiles from different places on earth suggested that anthropogenic mercury pollution after the Industrial Revolution is more severe in Northern Hemisphere than in Antarctica.

关键词： South China Sea red-footed booby ornithogenic sediment mercury anthropogenic source

Stimulation of gaseous phosphine production from Antarctic seabird guanos and ornithogenic soils

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Journal of Environmental Sciences 2009年第2期21卷 150-154页

作者： ZHU Renbin LIU Yashu sun Jianjun sun liguang GENG Jinju Institute of Polar Environment University of Science and Technology of China Hefei 230026 China State Key Laboratory of PoUution Control and Resource Reuse Nanjing University Nanjing 210093 China

Matrix-bound phosphine （MBP） is a general term used to indicate non-gaseous reduced phosphorus compounds that are transformed into phosphine gas upon reaction with bases or acids. Antarctic seabird guanos and ornithogenic soils were used as materials to compare the different digestion methods for transforming matrix-bound phosphine into phosphine gas. The results demonstrated that more phosphine gas in most of Antarctic environmental materials was formed of matrix-bound phosphine by caustic digestion than by acidic digestion. The comparative study on different digestion methods also revealed that the fraction of MBP converted to gaseous phosphine during the digestion depended on the temperature. The optimal digestion temperature was close to 70℃and the optimal digestion time was about 20 min. Acidic conditions were more favorable for the release of matrix-bound phosphine compared to the neutral conditions. A proper water dilution can increase the production and emission of phosphine from the Antarctic penguin guanos.

关键词： phosphine matrix-bound phosphine ornithogenic soil Antarctica penguin guano

饱和地基中劲芯水泥土墙隔振的二维BEM-FEM耦合分析

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世界地震工程 2024年第4期40卷 164-178页

作者：孙立光朱颖时刚王瑜刘攀郜新军朱超杰郑州地铁集团有限公司河南郑州450000 郑州大学土木工程学院郑州450001 中铁隧道集团二处有限公司河北廊坊065000

振动污染在国际上已被列入“七大环境公害”之一,填充沟是振动污染治理的一种常用隔振屏障。传统的填充沟受工程造价和施工工艺等限制工程中应用较困难;为克服上述问题,提出一种新型隔振屏障-内插预制芯墙的劲芯水泥土墙。对于饱和地基... 详细信息

振动污染在国际上已被列入“七大环境公害”之一,填充沟是振动污染治理的一种常用隔振屏障。传统的填充沟受工程造价和施工工艺等限制工程中应用较困难;为克服上述问题,提出一种新型隔振屏障-内插预制芯墙的劲芯水泥土墙。对于饱和地基中劲芯水泥土墙的隔振问题,饱和地基采用饱和土半解析边界元法(boundary element method,BEM)建模,劲芯水泥土墙采用有限元法(finite element method,FEM)建模,根据饱和地基-水泥土墙交界面的平衡和连续性条件,分别建立了劲芯水泥土墙对入射Rayleigh波(瑞利波)的远场被动隔振和对动力机器基础振动近场主动隔振的半解析BEM-FEM耦合分析方法,并对劲芯水泥土墙的隔振效果进行了计算分析。研究结果表明:饱和地基中设置劲芯水泥土墙能够起到较好的隔振作用,其隔振效果与混凝土墙基本相当且远优于纯水泥土墙;预制芯墙在劲芯水泥土墙隔振系统中起关键作用,为避免弹性波从芯墙底绕射而降低隔振效果,预制芯墙深度应与水泥土墙深度保持一致;增大芯墙厚度对隔振效果提升不大。在等深芯墙条件下,增大墙深能显著提高远场隔振效果,但对近场隔振效果提升较小;增大墙厚也可提高隔振效果,但提高幅度不大。实际工程中,建议结合工程造价和施工工艺,选择合适的水泥土墙和预制芯墙墙厚。此外,屏障距振源距离对主动隔振效果影响较小,建议根据被保护建筑与振源之间的实际情况,选择合适位置构建隔振屏障。

关键词：环境振动饱和地基劲芯水泥土搅拌墙隔振效果 BEM-FEM耦合方法

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

Ecosystem evolution of seal colony and the influencing factors in the 20th century on Fildes Peninsula,West Antarctica

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Journal of Environmental Sciences 2011年第9期23卷 1431-1436页

作者： Jing Huang liguang sun Xinming Wang Yuhong Wang Tao Huang Institute of Polar Environment University of Science & Technology of China Hefei 230026 China Guangzhou Institute of Geochemistry Chinese Academy of Science Guangzhou 510640 China Advanced Management Research Center Ningbo University Ningbo 315211 China

As the topmost predator in Antarctica,the seal is a unique indicator of Antarctic environment and climate *** this study,we collected a sediment core from the Fildes Peninsula of West Antarctica,and used cholesterol,cholestanol,epicoprostanol,coprostanol,and seal hair numbers as the proxy indicators of seal population size and phytol as of general vegetation,and we reconstructed the 20th century history of variation of the seal population and vegetation abundance on this *** sealing industry in the early 20th century caused the dramatic decline of seal population,and the ban of seal hunting since the 1960s led to its recovery of seal *** seal population during the past century was primarily controlled by human activities and krill *** reconstructed relation between seal population and vegetation abundance may offer new insights into Antarctic environment and ecology.

关键词： fecal sediment molecular marker human culture seal ecosystem climate

Biomineralization process occurring in iron mud of coastal seepage area of Zhoushan Island, Zhejiang Province

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Chinese Science Bulletin 2008年第12期53卷 1894-1904页

作者： WU ZiJun JIA Nan YUAN LinXi sun liguang School of Earth and Space Sciences University of Science and Technology of China Hefei 230026 China

The biomineralization process of iron oxidizing bacteria and its influence on accumulation of metals were investigated by modern biological observation techniques (i.e., SEM and TEM) and geochemical methods, in coastal area of Zhoushan Island, Zhejiang province where a thick ancient wood layers were buried, Results show that the iron mud samples mainly contain Leptothrix-like sheaths and Gal-lionella-like stalks, which are known as neutrophilic iron-oxidizing bacteria. These two bacteria are present as obviously different abundance in two sampling sites, which may be regulated by the geo-chemistry of seepage water. The biomineralization product of iron oxidizing bacteria is ferrihydrite, a poorly ordered iron oxide, and formation of amorphous mineral is affected by the factors of bacteria, minor Si and temperature preventing any further transformation into more crystalline phases. Organic functional groups, extracellular polymers and surface charges can provide favorable nucleation sites or template for formation of iron precipitates on the bacterial surface. The mineralization process of the iron oxidizing bacteria is divided into different stages, i.e., extracellular mineralization, intracellular mineralization and the whole cell mineralization. Furthermore, due to BIOS containing the bacterial organic matter, the accumulation capacity of metals specially Fe and Co is highly increased, suggest-ing that BIOS exert a degree of controlling in the cycling of metal elements in seepage area.

关键词：生物矿化过程铁矿浙江省渗流水

Heavy Metal Distributions and Source Tracing in the Lacustrine Sediments of Dongdao Island,South China Sea

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Acta Geologica Sinica(English Edition) 2008年第5期82卷 1002-1014页

作者： LIU Xiaodong sun liguang YIN Xuebin WANG Yuhong Institute of Polar Environment University of Science and Technology of China Hefei Anhui 230026 National Institutes of Health Bethesda MD 20892 USA

The levels and depth distributions of As, Cd, Cu, Zn, Pb, Hg, Fe and Mn in two sediment cores DY2 and DY4 collected from the ＂Cattle Pond＂ of Dongdao Island, South China Sea, were determined and analyzed with the main objective to identify the sources of these elements and evaluate the corresponding sedimentological and geochemical processes. Lithological characters and sedimentary parameters such as LOI950℃, CaO, LOI550℃ and TOC indicate that the depth of 96 cm and 87 cm are the critical points for DY2 and DY4 cores, respectively. As, Cd, Cu, Zn, Hg and P are remarkably enriched in the ornithogenic sediments above the critical depth points; their concentration-versus-depth profiles are similar to those of TOC and LOI550℃; the ratios of As, Cd, Cu, Zn, Hg over Ca are significantly correlated with P/Ca. Statistical and comparative analyses of these elements＇ levels in the ornithogenic sediments of DY2 and DY4 strongly suggest that seabird droppings are the main source of these elements. Additionally, for the upper sediment layers of DY2 and DY4 cores, Fe oxide sorption mechanism, like organic matter, may also play an important role in the abundances of heavy metals. Heavy metal Pb has geochemical characteristics distinctly different from those of As, Cd, Cu, Zn, Hg and P, and its isotope composition indicates an origin of anthropogenic emissions from the surrounding countries. These geochemical characteristics in the orinithogenic sediments of Xisha Islands are compared with the studies in the remote Antarctic and Arctic regions.

关键词： heavy metals elemental geochemistry ornithogenic sediments Dongdao Island South China Sea