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DNA Damage,Apoptosis and C-myc,C-fos,and C-jun Overexpression Induced by Selenium in Rat Hepatocytes

Biomedical and Environmental Sciences 2006年第3期19卷 197-204页

作者： RI-AN yu cheng-feng YANG XUE-MIN CHEN Department of Occupational and Environmental Health MOE Key Laboratory of Environment and Health School of Public Health Tongji Medical College Huazhong University of Science and Technology Wuhan 430030 Hubei China

Objective To study the effects of selenium on DNA damage, apoptosis and c-myc, c-fos, and c-jun expression in rat hepatocytes. Methods Sodium selenite at the doses of 5, 10, and 20 μmol/kg was given to rats by i.p. and there were 5 male SD rats in each group. Hepatocellular DNA damage was detected by single cell gel electrophoresis （or comet assay）. Hepatocellular apoptosis was determined by TUNEL （TdT-mediated dUTP nick end labelling） and flow cytometry. C-myc, c-fos, and c-jun expression in rat bepatocytes were assayed by Northern dot hybridization. C-myc, c-fos, and c-jun protein were detected by immunohistochemical method. Results At the doses of 5, 10, and 20μmol/kg, DNA damage was induced by sodium selenite in rat hepatocytes and the rates of comet cells were 34.40%, 74.80%, and 91.40% respectively. Results also showed an obvious dose-response relationship between the rates of comet cells and the doses of sodium selenite （r=0.9501, P〈0.01）. Sodium selenite at the doses of 5, 10, and 20μmol/kg caused c-myc, c-fos, and c-jun overexpression obviously. The positive brown-yellow signal for proteins of c-myc, c-fos, and c-jun was mainly located in the cytoplasm of bepatocytes with immunohistocbemical method. TUNEL-positive cells were detected in selenium-treated rat livers. Apoptotic rates （%） of selenium-treated liver cells at the doses of 5, 10, and 20 μmol/kg were （3.72±1.76）, （5.82±1.42）, and （11.76±1.87） respectively, being much higher than those in the control. Besides an obvious dose-response relationship between apoptotic rates and the doses of sodium selenite （r=0.9897, P〈0.01）, these results displayed a close relationship between DNA damage rates and apoptotic rates, and the relative coefficient was 0.9021, P〈0.01. Conclusion Selenium at 5-20μmol/kg can induce DNA damage, apoptosis, and overexpression of c-myc, c-fos, and c-jun in rat hepatocytes.

关键词： Selenium DNA damage Apoptosis C-myc C-fos C-jun

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Influence of Boron Content in Iron Oxide on Performance of Mn-Zn Ferrites

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Journal of Iron and Steel Research International 2010年第2期17卷 59-62页

作者： yu cheng-feng LI yu-guang XU Hui-yu GAO Jin-sheng College of Resource and Environmental Engineering East China University of Science and Technology Shanghai 200237 China Technology and Quanlity Management Department Baoshan Iron and Steel Co Ltd Shanghai 201900 China Shanghai Baosteel Tiantong Magneitic Materials Co Ltd Shanghai 201900 China

The ferrites of PC30 （Mn-Zn ferrites） were prepared by using a dry processing route. The effect of Mn-Zn ferrites doped with H3BO3 was investigated on the basis of microstructure analysis. The results of the samples doped with H3BO3 less than 5 × 10^-5 showed that the doping had no significant effect on power loss, initial permeability, fine grain microstructure, and density of Mn-Zn ferrites. With the further increase in H3BO3 doping （up to 1 × 10 ^-4 ）, the microstructure of Mn-Zn ferrites is in the critical state between fine grain and ＂sandwich＂, and the initial permeability and density of Mn-Zn ferrites begin falling quickly; the increased H3BO3 doping also results in deteriorated power loss properties. Thus, the control of the boron content in iron oxide is of utmost importance for the quality of Mn-Zn ferrites in producing process.

关键词： iron oxide Mn-Zn ferrite boron content initial permeability

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The Effect of Vineyard Cover Crop on Main Monomeric Phenols of Grape Berry and Wine in Vitis viniferal L. cv. Cabernet Sauvignon

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Agricultural Sciences in China 2010年第3期9卷 440-448页

作者： XI Zhu-mei ZHANG Zhen-wen cheng yu-feng LI Hua College of Enology Northwest A＆F University/Shaanxi Engineering Research Center for Viti-Viniculture Yangling 712100 P.R.China

This study was conducted to determine the effect of cover crop inter-row in vineyard on main mono-phenol content of grape berry and wine. Three such cover crops, two perennial legumes （white clover and alfalfa） and a perennial gramineous grass （tall fescue） were sown in vineyard. The main phenolic compounds of mature grape berry and wines vinified under the same conditions were extracted with ethyl acetate and diethyl ether and analyzed by high- performance liquid chromatography （HPLC） by comparing to soil tillage. A total of ten phenolic compounds were identified and quantified in the different grape berry and wines, including nonflavonoids （hydroxybenzoic and hydroxycinnamic acids） and flavonoids （flavanols and flavonols）. The concentration of flavonoid compounds （409.43 to 538.63 mg kg^-1 and 56.16 to 81.30 mg L^-1） was higher than nonflavonoids （76.91 to 98.85 mg kg^-1 and 30.65 to 41.22 mg L^-1） for Cabernet Sauvignon grape and wine under different treatments, respectively. In the flavonoid phenolics, Catechin was the most abundant in the different grapes and wines, accounting for 74.94 to 79.70% and 48.60 to 50.62% of total nonanthocyanin phenolics quantified, respectively. Compared to soil tillage, the sward treatments showed a higher content of main mono-phenol and total nonanthocyanin phenolics in grapes and wines. There were significant differences between two cover crop treatments （tall fescue and white clover） and soil tillage for the content of benzoic acid, salicylic acid, caffeic acid, catechin, and total phenolics in the grape berry （P 〈 0.05 or P〈0.01）. The wine from tall fescue cover crop had the highest gallic acid, caffeic acid and catechin. Cover crop system increased the total nonanthocyanin phenolics of grapes and wines in order of the four treatments： tall fescue, white clover, alfalfa, and soil tillage （control）. Cover crop in vineyard increased total phenols of grape berry and wine, and thus improved the quality of wine evidently.

关键词： vineyard cover crops inter-row Cabernet Sauvignon grape berry wine monomeric phenols

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A preliminary evaluation of high-performance advanced regional eta-coordinate model(H-AREM)

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Atmospheric and Oceanic Science Letters 2017年第1期10卷 1-8页

作者： cheng yu-feng XU You-Ping LI Li-Juan WANG Bin The State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics Institute of Atmospheric Physics Chinese Academy of Sciences Beijing China College of Earth Science University of Chinese Academy of Sciences Beijing China CpLA Troops PLA Troops No.78127 Chengdu China Beijing Institute of Applied Meteorology Beijing China

This paper preliminarily evaluates the speedup,scalability,and prediction skill of the highperformance advanced regional eta coordinate model（H-AREM）,which is based on several parallel processing methods and decomposition *** show that the parallel version of the model that is based on a modular parallel framework and a multidimensional domain decomposition strategy performs better overall,*** is faster and more scalable than the version based on a message passing interface and a one-dimensional decomposition *** particular,the scalability of the H-AREM with a resolution of 8 km approaches 8099 ***,in the H-AREM,higher resolutions result in more realistic precipitation predictions without remarkable increases in simulation time.

关键词： AREM parallel computation speed-up scalability

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Combining Phytate/Ca^(2+) Fractionation with Trichloroacetic Acid/Acetone Precipitation Improved Separation of Low-Abundant Proteins of Wheat (Triticum aestivum L.) Leaf for Proteomic Analysis

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Journal of Integrative Agriculture 2013年第7期12卷 1123-1129页

作者： Muhammad A R F Sultan LIU Hui cheng yu-feng ZHANG Pei-pei ZHAO Hui-xian State Key Laboratory of Crop Stress Biology for Arid Areas Ministry of Science and Technology/College of Life Sciences Northwest A&F University

Proteomic assessment of low-abundance leaf proteins is hindered by the large quantity of ribulose-1,5-bisphosphate carboxylase/oxygenase （Rubisco） present within plant leaf tissues. In the present study, total proteins were extracted from wheat （Triticum aestivum L.） leaves by a conventional trichloroacetic acid （TCA）/acetone method and a protocol first developed in this work. Phytate/Ca2＋ fractionation and TCA/acetone precipitation were combined to design an improved TCA/acetone method. The extracted proteins were analysed by two-dimensional gel electrophoresis （2-DE）. The resulting 2-DE images were compared to reveal major differences. The results showed that large quantities of Rubisco were deleted from wheat leaf proteins prepared by the improved method. As many as （758±4） protein spots were detected from 2-DE images of protein extracts obtained by the improved method, 130 more than those detected by the TCA/acetone method. Further analysis indicated that more protein spots could be detected at regions of pI 4.00-4.99 and 6.50-7.00 in the improved method-based 2-DE images. Our findings indicated that the improved method is an efficient protein preparation protocol for separating low-abundance proteins in wheat leaf tissues by 2-DE analysis. The proposed protocol is simple, fast, inexpensive and also applicable to protein preparations of other plants.

关键词： Triticum aestivum L. Rubisco low-abundance protein phytate/Ca2+ two-dimensional gel electrophoresis plant leaf proteomics

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Bioinformatic Analysis of BBTV Satellite DNA in Hainan

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Virologica Sinica 2011年第4期26卷 279-284页

作者： Nai-tong yu Tuan-cheng feng yu-liang Zhang Jian-hua Wang Zhi-xin Liu Institute of Tropical Bioscience and Biotechnology CA TAS Haikou 571101 China

Banana bunchy top virus (BBTV),family Nanaviridae,genus Babuvirus,is a single stranded DNA virus (ssDNA) that causes banana bunchy top disease (BBTD) in banana *** is the most common and most destructive of all viruses in these plants and is widespread throughout the Asia-Pacific *** this study we isolated,cloned and sequenced a BBTV sample from Hainan Island,*** results from sequencing and bioinformatics analysis indicate this isolate represents a satellite DNA component with 12 DNA sequences *** also predicted the physical and chemical properties,structure,signal peptide,phosphorylation,secondary structure,tertiary structure and functional domains of its encoding protein,and compare them with the corresponding quantities in the replication initiation protein of BBTV DNA1.

关键词： Banana bunchy top virus Satellite Prediction

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公司所得税与净出口:促进还是阻碍——基于跨国面板数据的实证研究

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国际贸易问题 2015年第5期 145-153页

作者：程风雨厦门大学经济学院国际经济与贸易系 361005

本文基于1995-2011年全球44个国家的面板数据,主要采用工具变量法与系统GMM,在一定程度上控制了变量内生性问题,实证考察公司所得税对一国净出口贸易的影响,继而采用面板门限模型,探讨贸易开放视角下两者之间的非线性关系。结果表明:不... 详细信息

本文基于1995-2011年全球44个国家的面板数据,主要采用工具变量法与系统GMM,在一定程度上控制了变量内生性问题,实证考察公司所得税对一国净出口贸易的影响,继而采用面板门限模型,探讨贸易开放视角下两者之间的非线性关系。结果表明:不管是发达国家还是发展中国家,公司所得税对净出口贸易存在促进作用;由于贸易开放度的差异,公司所得税对净出口贸易的影响呈现显著的门限效应,且随着开放程度的提高,公司所得税对净出口贸易的促进作用会逐步增强。

关键词：公司所得税净出口门限效应面板数据

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贸易开放视角下的地区税收竞争与经济增长——来自中国的经验证据

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财经论丛 2016年第5期 11-19页

作者：程风雨广州市社会科学院广东广州510410

经济全球化的深入使得一国之内税收竞争的增长效应更多地受制于对外开放因素的影响。本文基于2000-2013年中国29个省(市)的面板数据,旨在从贸易开放的视角实证考察税收竞争对经济增长的影响及作用机制。两阶段最小二乘法(2SLS)的研究结... 详细信息

经济全球化的深入使得一国之内税收竞争的增长效应更多地受制于对外开放因素的影响。本文基于2000-2013年中国29个省(市)的面板数据,旨在从贸易开放的视角实证考察税收竞争对经济增长的影响及作用机制。两阶段最小二乘法(2SLS)的研究结果表明,在影响区域经济增长方面,贸易开放与地区间税收竞争存在一定程度的策略替代性;面板门限模型(PTR)的运用,发现不同区域贸易开放度存在较大差异,从而形成税收竞争增长的类"N"效应。在考虑到贸易开放度区域异质的情形下,地区税收竞争依旧是促进区域经济增长的重要政策工具,注重税收竞争对政策工具的"精准"投放。

关键词：地区税收竞争贸易开放经济增长策略性替代门限效应

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发展中国家增值税存在相对贸易中性吗?——基于非正规经济的视角

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财经论丛 2015年第10期 24-31页

作者：程风雨广州市社会科学院广东广州510000

在各种现实条件下对增值税相对贸易中性效应的探讨,这是一个实证问题。本文从非正规经济视角出发,借助VAR模型对主流理论中发达国家的增值税贸易中性理论在发展中国家是否适用进行了检验。基于1994-2012年16个发展中国家的跨国面板数据... 详细信息

在各种现实条件下对增值税相对贸易中性效应的探讨,这是一个实证问题。本文从非正规经济视角出发,借助VAR模型对主流理论中发达国家的增值税贸易中性理论在发展中国家是否适用进行了检验。基于1994-2012年16个发展中国家的跨国面板数据,研究结果发现,发展中国家同样存在增值税相对贸易中性效应,非正规经济的存在可以在一定程度上解释相对贸易中性的存在问题。考虑到我国特殊的发展国情,本文利用1990-2012年我国多维变量时间序列数据,实证分析表明,在我国增值税对出口贸易发展具有一定阻碍作用,且并不存在显著的贸易中性效应。

关键词：增值税汇率非正规经济相对贸易中性 VAR模型

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增值税存在相对贸易中性效应吗——基于面板VAR模型的实证分析

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国际商务（对外经济贸易大学学报） 2015年第5期 134-143页

作者：程风雨广州市社会科学院广东广州510000

经济全球化下贸易自由度的不断提高,使得境内税的贸易效应问题走到国际经贸领域的前台。本文利用1994~2012年全球45个国家的面板数据,从宏观角度运用面板VAR模型,对增值税相对贸易效应问题展开实证研究。实证结果显示,从长期趋势看,不... 详细信息

经济全球化下贸易自由度的不断提高,使得境内税的贸易效应问题走到国际经贸领域的前台。本文利用1994~2012年全球45个国家的面板数据,从宏观角度运用面板VAR模型,对增值税相对贸易效应问题展开实证研究。实证结果显示,从长期趋势看,不管是发达国家还是发展中国家,总体上都存在增值税相对贸易中性效应;从不同税种的贸易效应的对比来看,相对于公司所得税而言,增值税更易阻碍国际贸易的稳定发展;汇率因素只能在一定程度上起到平抑增值税贸易阻碍效应的作用。

关键词：增值税公司所得税汇率中性效应面板VAR模型

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