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PATTERN, CAUSES AND ESSENCE OF DESERTIFICATION IN SAHEL OF WEST AFRICA

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Journal of Geographical Sciences 1995年第1期5卷 91-98页

作者： ding Dengshan (department of Geo and Ocean Sciences, nanjing university, nanjing 210008People’s Republic of china)

Sahel of Africa is one of the most seriously desertified regions in the world. It becomes notorious owing to severe drought anddesertification occurred during 1968-1973 in the region. This paperdiscusses the causes and essence of desertification in Sahel. Firstiy, thechanges of social and economic conditions in West Africa and theirinfluence on desertification are analysized. Then the pattem ofdesertification is described, and the causes and essence are ***, the author proposes some measures for prevation and control of desertification in the area.

关键词： desertification Sahel overgrazing excess economic activities

6-Hydroxydopamine-induced glutathione alteration occurs via glutathione enzyme system in primary cultured astrocytes

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Acta Pharmacologica Sinica 2005年第7期26卷 799-805页

作者： Ji ZHANG Jun HU Jian-hua ding Hong-hong YAO Gang HU~2 department of Pharmacology,nanjing Medical university,nanjing 210029,china department of Pharmacology Nanjing Medical University Nanjing China

Aim:To define the role of enzymes involved in glutathione metabolism in 6-hydroxydopamine(6-OHDA)-induced glutathione alteration in primary ***:Total glutathione(GSx)levels were determined using themodified enzymatic microtiter plate *** mRNA levels of γ-glutamylcysteinesynthetase(γGCS),γ-glutamyltransferase(γGT),glutathione peroxidase(GPx),GR(glutathione reductase),and glutathione transferases(GST)were determined us-ing RT-PCR.γGT activity was determined using 7GT assay ***:Inprimary cultured astrocytes,6-OHDA induced a significant elevation of cellularGSx levels after treatment for 24 ***,the GSx levels decreased after 24 hand the values were even lower than the value in the control group without 6-OHDA at 48 ***-PCR data showed that the mRNA levels of γGCS,the rate-limiting enzyme of γ-L-glutamyl-L-cysteinylglycine(GSH)synthesis,were increasedby 6-OHDA after treatment for 24 h and 48 h;the mRNA levels of GPx,GR,and GSTdid not alter in 6-OHDA-treated astrocytes after treatment for 24 h and 48 h;and 6-OHDA increased the mRNA levels and the activity of TGT after treatment for 48 h,which induced a decrease in GSx levels,despite the up-regulation of γCS afterexposure to 6-OHDA for 48 ***:The change in γGCS correlated withthe increase in GSH levels induced by 6-OHDA after treatment for 24 *** levelsdecreased because of increased γGT mRNA levels and γGT activity induced by 6-OHDA after treatment for 48 h.

关键词： 6-hydroxydopamine glutathione oxidative stress glutamate-cysteine ligase gammaglutamyltransferase

Differentiation of embryoid-body cells derived from embryonic stem cells into hepatocytes in alginate microbeads in vitro

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Acta Pharmacologica Sinica 2007年第12期28卷 1924-1930页

作者： Sheng FANG,Yu-dong QIU,Liang MAO,Xiao-lei SHI,De-cai YU,Yi-tao ding~2department of Hepatobiliary Surgery,Affiliated Drum Tower Hospital,Medical College of nanjing university,nanjing 210008,china department of Hepatobiliary Surgery Affiliated Drum Tower Hospital Medical College of Nanjing University Nanjing China

Aim:Embryonic stem (ES) cells are being widely investigated as a promisingsource of hepatocytes with their proliferative,renewable,and ***,controlled and scalable ES cell differentiation culture intofunctional hepatocytes is *** this study,we examined the differentiat-ing potential of embryoid-body cells derived from ES cells into hepatocytes inalginate microbeads containing exogenous growth factors in ***:.Embryoid bodies were formed from ES cells by suspension *** cultured for 5 d were treated with *** disaggregated cellswere encapsulated in alginate microbeads and stimulated with exogenous growthfactors to induce hepatic *** the course of cell differentiation,cellmorphology and viability were observed,and the expression patterns of somegenes of the hepatocyte were confirmed by *** immunofluorescenceanalysis revealed the expression of albumin (ALB) and cytokeratin-18 (CK18).Hepatocyte functional assays were confirmed by the secretion of ALB and ***:We showed that embryoid-body cells could maintain cell viability inalginate microbeads in *** also found that directed differentiated cellsexpressed several hepatocyte genes including α-fetoprotein (AFP),ALB,Cyp7a1,CK18,transthyretin (TTR) and tyrosine aminotransferase (TAT) and producedALB and urea in alginate *** directed differentiated cells expressedALB and CK18 proteins on d ***,embryoid-body cells could not formhepatocytes without exogenous growth factors in alginate ***:The differentiation of embryoid-body cells into hepatocytes con-taining exogenous growth factors in alginate microbeads gives rise to functionalhepatocytes and may develop scalable stem cell differentiation strategies forbioartificial livers and hepatocyte transplantation.

关键词： alginate cell culture encapsulation hepatocytes stem cell differentiation

Mycophenolic acid inhibits SLE-associated cytokine expression and promotes apoptosis of peripheral blood mononuclear cells from patients with systemic lupus erythematosus

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Acta Pharmacologica Sinica 2006年第8期27卷 1051-1057页

作者： ding-lei SU~(2,3) Hui-juan WANG~2 Xiao-hui JI~(2,5) Yuan-yuan LI~4 Heng-bao XUAN~4 Chun HENG~4 Yu-feng LI~4 ~2department of Immunology,nanjing Medical university,nanjing 210029,china:~3department of Hematology,nanjing First Hospital Affiliated to nanjing Medical university,nanjing 210029,china ~4department of Hematology,Affiliated Huai'an First Hospital of nanjing Medical university,Huai'an 223300.china department of Immunology Nanjing Medical University Nanjing China department of Hematology Nanjing First Hospital Affiliated to Nanjing Medical University Nanjing China department of Hematology Affiliated Huai'an First Hospital of Nanjing Medical University Huai'an China

Aim:To investigate the effect of the novel immunosuppressant mycophenolicacid（MPA）on cytokine production and apoptosis of the peripheral blood mono-nuclear cells（PBMC）of patients with systemic lupus erythematosus（SLE）.Methods:The levels of IL-10,IL-12,IFN-γ,sFas and sFasL in the supernatants ofcultured PBMC from 41 SLE patients was determined by the ABC-ELISA *** percentage of IFN-γIL- 10-,IFN-γ-IL-10+,and IFN-γ+IL-10+subsets in CD4+ceils were detected by three-color flow *** percentage of apoptoticTh cells was detected by AV-FITC/PI flow *** from 22 sex-andage-comparable healthy people were used as normal ***:The lev-els of IL-10,IL-12,and IFN-γwere all significantly elevated in the supernatants ofcultured PBMC from SLE samples,compared with normal *** enhancedproductions of IL-10,IL-12,and IFN-γ by PBMC from SLE both spontaneouslyand stimulated by phytohaemagglutinin（PHA）were significantly reduced by *** percentages of CD4+IFN-γIL-10+and CD4+IFN-γ+IL-10+cell subsets in cul-tured PBMC from SLE were significantly increased,but decreased when MPA wasadded into the *** being cultured in vitro for 48h,the PBMC of SLEpatients showed a higher secretion of sFasL as well as a higher percentage *** significantly increased the apoptotic percentage of SLE PBMC,but reduced the secretion of sFasL and ***:MPA reduces theabnormal production of SLE-associated cytokines,such as IL-10,IL-12,and IFN-γ,inhibits the increase of CD4+IFN-γ+IL-10,CD4+IFN-γIL-10+and CD4+IFN-γ+IL-10+subset;and promotes the apoptosis of PBMC in SLE patients,which may beassociated with the therapeutic mechanism of MPA for SLE.

关键词： systemic lupus erythematosus mycophenolic acid cytokine apoptosis therapeutic mechanism

Optical Response of Granular YBCO Weak Link

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Chinese Journal of Lasers 1996年第1期B5卷 43-46页

作者： XU Kexi, ZHOU Shiping, BAO Jiashan(Physics department, Shanghai university, Jia-ding, Shanghai 201800, china)XU Weiwei, WANG Huabing(nanjing university, nanjing 210093, china) Shanghai Univ Shanghai China

A preliminary result on photoresponse of granular YBa2Cu3O7-x （YBCO） weak link is reported. The Josephson eritical current Ic is suppressed by the light illumination. At lower temperature （T= 64. 5K ）, the hysteresis in I-V charateristics of the weak link appears. These features of the granular high- Tc oxide Josephson junctions may be usefull for optical detection purpose.

关键词： :Granular superconducting films weak link photoresponse

Polymer-assisted nanoparticulate contrast-enhancing materials

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Science china Chemistry 2010年第3期53卷 479-486页

作者： ding Yin1,3,HU Yong2,WU Wei1 & JIANG XiQun1 1Laboratory of Mesoscopic Chemistry and department of Polymer Science and Engineering,College of Chemistry & Chemical Engineering,nanjing university,nanjing 210093,china 2National Laboratory of Solid State Microstructure,department of Material Science and Engineering,nanjing university,nanjing 210093,china 3Key Laboratory of Analytical Chemistry for Life Science,Ministry of Education,School of Chemistry and Chemical Engineering,nanjing university,nanjing 210093,china Laboratory of Mesoscopic Chemistry and department of Polymer Science and Engineering College of Chemistry & Chemical Engineering Nanjing University Nanjing China Key Laboratory of Analytical Chemistry for Life Science Ministry of Education School of Chemistry and Chemical Engineering Nanjing University Nanjing China National Laboratory of Solid State Microstructure Department of Material Science and Engineering Nanjing University Nanjing China

The application of nanotechnology in medicine research has significant potential in modern biomedical research,disease diagnosis and *** fluorophore-based detection techniques have been widely used as imaging and signal transduction tools for the detection of trace levels of *** photosensitivity of the fluorophores,however,limits their application in such complex environments as living bio-systems where degradation or photobleaching *** nanoparticles have unique and stable optical,electrical,magnetic and catalytic properties because of their various shapes,sizes and *** potential of the nanoparticles as novel imaging agents has been studied as a possible solution to this *** modification of inorganic nanoparticles could enhance their biostability in physiological conditions and ability of targeting bioactive molecules.

关键词： contrast agent cell image gold nanoparticles iron oxide nanoparticles carbon nanotubes polymeric-inorganic hybrid nanoparticles

Specific CEA-producing colorectal carcinoma cell killing with recombinant adenoviral vector containing cytosine deaminase gene

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World Journal of Gastroenterology 2002年第2期8卷 270-275页

作者： Li-Zong Shen Wen-Xi Wu Qiang ding Yi-Bing Hua,department of General Surgery,The First Affiliated Hospital of nanjing Medical university,nanjing,210029,Jiangsu Province,china De-Hua Xu Zhong-Cheng Zheng Xin-Yuan Liu,Shanghai Institute of Biochemistry and Cell Biology,The Chinese Academy of Sciences,Shanghai,200031,china Kun Yao,department of Microbiology and Immunology,nanjing Medical university,nanjing,210029,Jiangsu Province,china department of General Surgery The First Affiliated Hospital of Nanjing Medical University 300 Guangzhou Road Nanjing 210029 Jiangsu Province China.

AIM: To kill CEA positive colorectal carcinoma cells specifically using the E coli cytosine deaminase (CD) suicide gene, a new replication-deficient recombinant adenoviral vector was constructed in which CD gene was controlled under CEA promoter and its in vitro cytotoxic effects were evaluated. METHODS: Shuttle plasmid containing CD gene and regulatory sequence of the CEA gene was constructed and recombined with the right arm of adenovirus genome DNA in 293 cell strain. Dot blotting and PCR were used to identify positive plaques. The purification of adenovirus was performed with ultra-concentration in CsCl step gradients and the titration was measured with plaque formation assay. Cytotoxic effects were assayed with MTT method, The fifty percent inhibition concentration (IC(50)) of 5-FC was calculated using a curve-fitting parameter. The human colorectal carcinoma cell line, which was CEA-producing, and the CEA-nonproducing Hela cell line were applied in cytological tests. An established recombinant adenovirus vector AdCMVCD, in which the CD gene was controlled under CMV promoter, was used as virus control. Quantitative results were expressed as the mean +/- SD of the mean. Statistical analysis was performed using ANOVA test. RESULTS: The desired recombinant adenovirus vector was named AdCEACD. The results of dot blotting and PCR showed that the recombinant adenovirus contained CEA promoter and CD gene. Virus titer was about 5.0 X 10(14)pfu/L(-1) after purification. The CEA-producing Lovo cells were sensitive to 5-FC and had the same cytotoxic effect after infection with AdCEACD and AdCMVCD (The IC(50) values of 5-FC in parent Lovo cells, Lovo cells infected with 100 M.O.I AdCEACD and Lovo cells infected with 10 M.O.I AdCMVCD were >15000, 216.5+/-38.1 and 128.8+/-25.4 micromol.L(-1), Pdingly when the m.o.i of adenoviruses were enhanced (The value of IC(50) of 5-FC was reduced to 27.9+/-4.2 micr

关键词： Gene Therapy Genetic Vectors Adenoviridae Animals Antimetabolites Bystander Effect Carcinoembryonic Antigen Cell Line Colorectal Neoplasms Cytosine Deaminase Flucytosine Hela Cells Humans Nucleoside Deaminases Promoter Regions (Genetics) Research Support, Non-U.S. Gov't Tumor Cells, Cultured

MICROSTRUCTURE AND TENSILE PROPERTIES OF Fe_3Al-BASED ALLOYS WITH VC AND TiC ADDITIONS

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Acta Metallurgica Sinica(English Letters) 2001年第4期14卷 248-252页

作者： W.L. Xu, Y.S. Sun and S.S. ding department of Materials Science & Engineering, Southeast university, nanjing 210096, china Dept. of Mat. Sci. Southeast Univ. Nanjing 210096 China

Microstructure and tensile properties of Fe3 Al-based alloys with the additions of TiC and VC particles have been investigated. Results show that the formation of TiC particles results in the refinement of the macrostructure of as-cast ingots. Although the addition of VC particles does not cause any significant change of the as-cast microstructure, the microstructure of the alloy after hot-working and recrystallization has been found to be refined. The formation of both VC and TiC particles results in the increase of yield strength, especially at the high temperature of 600°C.

关键词： Aluminum alloys Doping (additives) Microstructure Tensile strength Titanium carbide

Large magnetostriction of Nd_(0.2)Tb_(0.3)Dy_(0.5)Fe_(1.93)/epoxy composites in a wide temperature range

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Journal of Rare Earths 2024年第4期42卷 705-709页

作者： Hehe ding Yangguang Shi Shaolong Tang MIIT Key Laboratory of Aerospace Information Materials and Physics Department of Applied PhysicsNanjing University of Aeronautics and AstronauticsNanjing210016China National Laboratory of Solid State Microstructures Nanjing UniversityNanjing210093China

We report the magnetostrictive performance of the Nd_(0.2)Tb_(0.3)Dy_(0.5)Fe_(1.93)/epoxy *** of M?ssbauer spectra and the XRD results indicate that the easy magnetic direction of the Nd_(0.2)Tb_(0.3)Dy_(0.5)Fe_(1.93)compound is alongdirection with spontaneous magnetostrictionλ111 of1900 ***-oriented Nd_(0.2)Tb_(0.3)Dy_(0.5)Fe_(1.93)/epoxy composites with particle volume fractions of20 vol%-55 vol%were *** measurements demonstrate that the composite is highly *** raw material cost of Nd_(0.2)Tb_(0.3)Dy_(0.5)Fe_(1.93)is about 85%of that of the Terfenol-D(Tb_(0.3)Dy_(0.7)Fe_(2))***_(0.2)Tb_(0.3)Dy_(0.5)Fe_(1.93)/epoxy composites possess comparable magnetostriction with those composites made of Tb_(0.3)Dy_(0.7)Fe_(2)*** room temperature,the magnetostrictionλ_Ⅱof the Nd_(0.2)Tb_(0.3)Dy_(0.5)Fe_(1.93)/epoxy composite reaches 420 ppm at a low field of 80 kA/m and about1000 ppm at 239 kA/*** addition,the composite exhibits a large saturation magnetostrictionλ_Ⅱover1200 ppm from 300 to 100 K,suggesting its potential applications as a low-cost magnetostrictive material in a wide temperature ***,the current study offers an opportunity to widen the operating temperature range of the magnetostrictive composite.

关键词： Magnetostrictive composite Nd_(0.2)Tb_(0.3)Dy_(0.5)Fe_(1.93) Wide temperaturerange Laves phase Rare earths