检索结果-南通市图书馆

Synthesis and Anti-tumor Activity of Novel Amide Derivatives of Ursolic Acid

在线全文

学校读者我要写书评

暂无评论

Chemical Research in Chinese Universities 2008年第1期24卷 42-46页

作者： LIU Dan meng yan-qiu ZHAO Juan CHEN Li-gong College of Pharmaceuticals ＆ Biotechnology Tianjin University Tianjin 300072 P. R. China Faculty of Pharmaceutical Engineering Shenyang Institute of Chemical Technology Shenyang 110142 P. R. China

Ursolic acid was modified at C3 and C28 position to obtain fourteen derivatives including twelve novel compounds, and their chemical structures were characterized by IR, ^1H NMR and MS. Cell growth inhibitory effects of the derivatives against Hela cell were evaluated by MTT assay. All these derivatives were found to have stronger cell growth inhibitory than their parent compound, ursolic acid. The derivatives with a substituted acetyl group at C3 hydroxyl group show better activities than those with an unsubstituted hydroxyl group.

关键词： Ursolic acid Amide derivatives Anti-tumor activity

齐墩果酸C-3及C-28位衍生物的设计合成及抗肿瘤活性研究

在线全文

学校读者我要写书评

暂无评论

化学试剂 2024年第10期46卷 91-98页

作者：谷彤彤陈果刘黎明孟艳秋沈阳化工大学制药工程教研室辽宁沈阳110142

设计及合成一系列新型齐墩果酸衍生物,并对其进行抗肿瘤活性及分子对接研究。以天然产物齐墩果酸为先导化合物,对其C-3羟基和C-28羧基进行结构修饰,合成新型齐墩果酸衍生物;采用MTT法测定化合物对人肺癌细胞(A549)和乳腺癌细胞(MCF-7)... 详细信息

设计及合成一系列新型齐墩果酸衍生物,并对其进行抗肿瘤活性及分子对接研究。以天然产物齐墩果酸为先导化合物,对其C-3羟基和C-28羧基进行结构修饰,合成新型齐墩果酸衍生物;采用MTT法测定化合物对人肺癌细胞(A549)和乳腺癌细胞(MCF-7)的体外抗肿瘤活性;利用计算机辅助药物设计方法分析所合成化合物关键基团与PI3K受体的作用方式。合成了12个未见文献报道的齐墩果酸衍生物,结构均经1HNMR、13 CNMR及MS谱确证。活性测试结果表明,化合物N-[3β-乙酰氧基-齐墩果烷-12-烯-28-酰]-2-氨基乙醇-4-三氟甲基苯甲酸酯(Ⅰ3)、3β-乙酰氧基-齐墩果烷-12-稀-28β-[N-(3-苯甲酰氨基丙基)]甲酰氨基(Ⅱ1)对肿瘤细胞的抑制活性明显高于母体齐墩果酸与阳性对照药Alpelisib相当。经过结构修饰后的齐墩果酸衍生物具有一定的抗肿瘤作用,值得进一步研究。

关键词：齐墩果酸衍生物分子对接结构修饰抗肿瘤活性 PI3K

Fuzzy-Model-Based Finite Frequency Fault Detection Filtering Design for Two-Dimensional Nonlinear Systems

在线全文

学校读者我要写书评

暂无评论

IEEE/CAA Journal of Automatica Sinica 2024年第10期11卷 2099-2110页

作者： meng Wang Huaicheng yan Jianbin qiu Wenqiang Ji Key Laboratory of Smart Manufacturing in Energy Chemical Process Ministry of EducationSchool of Information Science and EngineeringEast China University of Science and TechnologyShanghai 200237China Research Institute of Intelligent Control and Systems School of AstronauticsHarbin Institute of TechnologyHarbin 150080China School of Artificial Intelligence Hebei University of TechnologyTianjin 300401China IEEE

This article studies the fault detection filtering design problem for Roesser type two-dimensional(2-D)nonlinear systems described by uncertain 2-D Takagi-Sugeno(T-S)fuzzy ***,fuzzy Lyapunov functions are constructed and the 2-D Fourier transform is exploited,based on which a finite frequency fault detection filtering design method is proposed such that a residual signal is generated with robustness to external disturbances and sensitivity to *** has been shown that the utilization of available frequency spectrum information of faults and disturbances makes the proposed filtering design method more general and less conservative compared with a conventional nonfrequency based filtering design ***,with the proposed evaluation function and its threshold,a novel mixed finite frequency H_(∞)/H_(-)fault detection algorithm is developed,based on which the fault can be immediately detected once the evaluation function exceeds the ***,it is verified with simulation studies that the proposed method is effective and less conservative than conventional non-frequency and/or common Lyapunov function based filtering design methods.

关键词： Fault diagnosis finite frequency specifications mixed H_(∞)/H_(-)performance two-dimensional nonlinear systems

Synthesis and Anti-tumor Activity of Novel Glycyrrhetinic Acid Derivatives

在线全文

学校读者我要写书评

暂无评论

Chemical Research in Chinese Universities 2012年第2期28卷 214-219页

作者： meng yan-qiu DING Jia-qi LIU Yuan NIE Hui-hui GUAN Sai ZOU Chao ZHAO Na CHEN Hong CAO Bo Department of Pharmaceutical Engineering Shenyang University of Chemical TechnologyShenyang 110142P.R.China Department of Pharmacognosy Medical College of Chinese People's Armed Police ForcesTianjin 300162P R.China

Twenty-five derivatives of glycyrrhetinic acid（GA） modified on the A-ring,at C30 and C11 positions were *** in vitro cytotoxicity against various cancer cell lines[henrietta lacks strain of cancer cells（HeLa）,human hepatocellular liver carcinoma cells（HepG2） and human gastric carcinoma cells（BGC-823）] was evaluated by standard MTT[3-（4,5-dimethyl-2-thiazol-yl）-2,5-diphenyl-2H-tetrazolium bromide] *** the tested derivatives were found to have stronger cell growth inhibitory than their parent compound *** them,compounds 3a,5a,and 8d have similar activity on HeLa cell line,and compound 8a has similar activity on HeLa,HepG2 and BGC-823 cell lines as Gefitinib.

关键词： Glycyrrhetinic acid derivative Anti-tumor activity Structure modification

An experimental study of impact loading on deck of shore-connecting jetties exposed to oblique waves and current

在线全文

学校读者我要写书评

暂无评论

Journal of Hydrodynamics 2014年第2期26卷 216-225页

作者：孟艳秋陈国平严士常童朝锋 Key Laboratory of Coastal Disaster and Defence Ministry of Education Hohai University College of Harbour Coastal and Offshore Engineering Hohai University State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering Hohai University

The impact pressure from waves is an important issue to be considered in the design of coastal structures. In this paper, the waves acting on the deck of a shore-connecting jetty on a slope exposed to oblique waves and in the presence of current are examined based on laboratory experiments. The impact pressures are measured on a 1：50 scale model of a jetty head with down-standing beams and berthing members. The relations of the impact pressure with the incident wave angle and the current velocity are examined. It is shown that the impact pressure is sensitive to the wave angle and the current velocity. A computational model for the impact load on the deck of shore-connecting jetties exposed to oblique waves and current is developed.

关键词： wave current impact pressure shore-connecting jetty on a slope

Model-driven path planning for robotic plasma cutting of branch pipe with single Y-groove based on pipe-rotating scheme

在线全文

学校读者我要写书评

暂无评论

Advances in Manufacturing 2024年第1期12卷 94-107页

作者： yan Liu qiu Tang Xin-Cheng Tian School of Control Science and Engineering Shandong UniversityJinan250061People’s Republic of China Engineering Research Center of Intelligent Unmanned System Ministry of EducationJinan250061People’s Republic of China School of Mechanical and Electronic Engineering Shandong Jianzhu UniversityJinan250101People’s Republic of China

The automatic cutting of intersecting pipes is a challenging task in *** improved automation and accuracy,this paper proposes a model-driven path planning approach for the robotic plasma cutting of a branch pipe with a single ***,it summarizes the intersection forms and introduces a dual-pipe intersection *** on this model,the moving three-plane structure(a description unit of the geometric characteristics of the intersecting curve)is constructed,and a geometric model of the branch pipe with a single Y-groove is ***,a novel mathematical model for plasma radius and taper compensation is ***,the compensation model and groove model are integrated by establishing movable ***,to prevent collisions between the plasma torch and workpiece,the torch height is planned and a branch pipe-rotating scheme is *** the established models and moving frames,the planned path description of cutting robot is provided in this novel *** accuracy of the proposed method is verified by simulations and robotic cutting experiments.

关键词： Automatic groove cutting of intersecting pipes Model-driven robot path planning Plasma beam radius and taper compensation

Hard-carbon hybrid Li-ion/metal anode enabled by preferred mesoporous uniform lithium growth mechanism

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Energy Chemistry 2024年第1期88卷 252-259,I0006页

作者： Fang yan yan Liu Yuan Li yan Wang Zicen Deng meng Li Zhenwei Zhu Aohan Zhou Ting Li Jingyi qiu Gaoping Cao Shaobo Huang Biyan Wang Hao Zhang School of Chemistry and Biological Engineering University of Science and TechnologyBeijing 100083China Research Institute of Chemical Defense Beijing 100191China College of Physics and Engineering Henan University of Science and TechnologyLuoyang 471023HenanChina National Base for International Science&Technology Cooperation School of ChemistryXiangtan UniversityXiangtan 411105HunanChina Materials and Manufacturing Department Beijing University of TechnologyBeijing 100124China

To achieve high energy density in lithium batteries,the construction of lithium-ion/metal hybrid anodes is a promising *** particular,because of the anisotropy of graphite,hybrid anode formed by graphite/Li metal has low transport kinetics and is easy to causes the growth of lithium dendrites and accumulation of dead Li,which seriously affects the cycle life of batteries and even causes safety ***,by comparing graphite with two types of hard carbon,it was found that hybrid anode formed by hard carbon and lithium metal,possessing more disordered mesoporous structure and lithophilic groups,presents better *** indicate that the mesoporous structure provides abundant active site and storage space for dead *** the synergistic effect of this structure and lithophilic functional groups(–COOH),the reversibility of hard carbon/lithium metal hybrid anode is maintained,promoting uniform deposition of lithium metal and alleviating formation of lithium *** hybrid anode maintains a 99.5%Coulombic efficiency(CE)after 260 cycles at a specific capacity of 500 m Ah/*** work provides new insights into the hybrid anodes formed by carbon-based materials and lithium metal with high specific energy and fast charging ability.

关键词： Hard carbon/Li metal hybrid anode Mesoporous structure Surface oxygen functional group Fast charging Lithium batteries

High-capacity dilithium hydroquinone cathode material for lithium-ion batteries

在线全文

学校读者我要写书评

暂无评论

National Science Review 2024年第6期11卷 206-213页

作者： Yong Lu Haoqin Han Zhuo yang Youxuan Ni Zhicheng meng qiu Zhang Hao Wu Weiwei Xie Zhenhua yan Jun Chen Frontiers Science Center for New Organic Matter Key Laboratory of Advanced Energy Materials Chemistry(Ministry of Education) State Key Laboratory of Advanced Chemical Power SourcesCollege of ChemistryNankai University

Lithiated organic cathode materials show great promise for practical applications in lithium-ion batteries owing to their Li-reservoir characteristics. However, the reported lithiated organic cathode materials still suffer from strict synthesis conditions and low capacity. Here we report a thermal intermolecular rearrangement method without organic solvents to prepare dilithium hydroquinone（Li2Q）, which delivers a high capacity of 323 m Ah g-1with an average discharge voltage of 2.8 V. The reversible conversion between orthorhombic Li2Q and monoclinic benzoquinone during charge/discharge processes is revealed by in situ X-ray diffraction. Theoretical calculations show that the unique Li–O channels in Li2Q are beneficial for Li+ion diffusion. In situ ultraviolet-visible spectra demonstrate that the dissolution issue of Li2Q electrodes during charge/discharge processes can be handled by separator modification, resulting in enhanced cycling stability. This work sheds light on the synthesis and battery application of high-capacity lithiated organic cathode materials.

关键词： lithium-ion batteries cathode materials lithiated organic materials dilithium hydroquinone separator modification

NLRP3-mediated autophagy dysfunction links gut microbiota dysbiosis to tau pathology in chronic sleep deprivation

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Zoological Research 2024年第4期45卷 857-874页

作者： Na Zhao Xiu Chen qiu-Gu Chen Xue-Ting Liu Fan Geng meng-meng Zhu Fu-Ling yan Zhi-Jun Zhang Qing-Guo Ren Department of Neurology School of MedicineSoutheast UniversityNanjingJiangsu 210009China Department of Neurology Affiliated Zhongda HospitalSoutheast UniversityNanjingJiangsu 210009China

Emerging evidence indicates that sleep deprivation(SD)can lead to Alzheimer’s disease(AD)-related pathological changes and cognitive ***,the underlying mechanisms remain *** the present study,we identified the existence of a microbiota-gut-brain axis in cognitive deficits resulting from chronic SD and revealed a potential pathway by which gut microbiota affects cognitive functioning in chronic *** findings demonstrated that chronic SD in mice not only led to cognitive decline but also induced gut microbiota dysbiosis,elevated NLRP3 inflammasome expression,GSK-3βactivation,autophagy dysfunction,and tau hyperphosphorylation in the *** with the“SD microbiota”replicated the pathological and behavioral abnormalities observed in chronic sleep-deprived ***,both the deletion of NLRP3 in NLRP3-/-mice and specific knockdown of NLRP3 in the hippocampus restored autophagic flux,suppressed tau hyperphosphorylation,and ameliorated cognitive deficits induced by chronic SD,while GSK-3βactivity was not regulated by the NLRP3 inflammasome in chronic ***,deletion of NLRP3 reversed NLRP3 inflammasome activation,autophagy deficits,and tau hyperphosphorylation induced by GSK-3βactivation in primary hippocampal neurons,suggesting that GSK-3β,as a regulator of NLRP3-mediated autophagy dysfunction,plays a significant role in promoting tau ***,gut microbiota dysbiosis was identified as a contributor to chronic SD-induced tau pathology via NLRP3-mediated autophagy dysfunction,ultimately leading to cognitive ***,these findings highlight GSK-3βas a regulator of NLRP3-mediated autophagy dysfunction,playing a critical role in promoting tau hyperphosphorylation.

关键词： Chronic sleep deprivation Tau pathology NLRP3 inflammasome Autophagy GSK-3β Microbiota-gut-brain axis