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Detecting and Identifying in vivo Metabolites of Brodimoprim via LC/ESI-MS with Data-dependent Scanning

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Chemical Research in Chinese Universities 2008年第4期24卷 430-436页

作者： LIN Yan-ping SI Duan-yun LIU chang-xiao Department of Pharmaceutical Engineering School of Chemical Engineering and Technology Tianjin University Tianjin 300072 P. R. China Tianjin State Key Laboratory of PharmacoMnetics and Pharmacodynamics Tianjin Institute of Pharmaceutical Research Tianjin 300193 P. R. China

The present article covers a simple approach to detect and subsequently identify in vivo metabolites of brodimoprim, using high performance liquid chromatography coupled to ion trap mass spectrometer（LC/ESI-MS）, which is based on a data-dependent acquisition of isotope ions and result verified by full scan mass spectrum. The distinguished advantage of data-dependent scan is rapidness because it requires minimum sample preparation, and all the necessary data can be obtained in one chromatographic run. In addition, it is highly sensitive and selective, allowing detection of trace metabolites even in the presence of complex biomatrix. As a result, four phase-Ⅰ（M1--M4） and four Phase-Ⅱ（M5--M8） metabolites of brodimoprim were identified in urine after the oral administration of hrodimoprim to Wistar rats. Their chemical structures were proposed based on the interpretation of their CID fragmentation characterizations and the metabolic pathway was exhibited in this article.

关键词： LC/ESI-MS Data-dependant scan Metabolite identification Brodimoprim

Intestinal permeability of metformin using single-pass intestinal perfusion in rats

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World Journal of Gastroenterology 2006年第25期12卷 4064-4070页

作者： Nai-Ning Song Quan-Sheng Li chang-xiao Liu School of Chemical Engineering and Technology Tianjin University Tianjin 300072 China National Key Laboratory of Pharmacokinetics and Pharmacodynamics Tianjin Institute of Pharmaceutical Research Tianjin 300193 China National Key Laboratory of Pharmacokinetics and Pharmacodynamics Tianjin Institute of Pharmaceutical Research Tianjin 300193 China

AIM： To characterize the intestinal transport and mechanism of metformin in rats and to investigate whether or not metformin is a substrate for P-glycoprotein （P-gp）. METHODS： The effective intestinal permeability of metformin was investigated using single-pass intestinal perfusion （SPIP） technique in male Waster rats. SPIP was performed in three isolated intestinal segments （duodenum, jejunum and ileum） at the same concentration of metformin （50 μg/mL） to test if the intestinal transport of metformin exhibited site- dependent changes, and in a same isolated intestinal segment （duodenal segment） at three different concentrations of metformin （10, 50, 200 μg/mL） to test if the intestinal transport of metformin exhibited concentration-dependent changes. Besides, P-gp inhibitor verapamil （400 μg/mL） was co-perfused with metformin （50 μg/mL） in the duodenum segment to find out if the intestinal absorption of metformin was affected by P-gp exiting along the gastrointestinal track. Stability studies were conducted to ensure that the loss of metformin could be attributed to intestinal absorption. RESULTS： The effective permeability values （Peff） of metformin in the jejunum and ileum at 50μg/mL were significantly lower than those in the duodenum at the same concentration. Besides, Peff values in the duodenum at high concentration （200 μg/mL） were found to be significantly lower than those at low and medium concentrations （10 and 50 μg/mL）. Moreover the coperfusion with verapamil did not increase the Peff value of metformin at 50 μg/mL in the duodenum.CONCLUSION： Metformin could be absorbed from the whole intestine, with the main absorption site at duodenum. This concentration-dependent permeability behavior in the duodenum indicates that metformin is transported by both passive and active carrier-mediated saturable mechanism. The Peff value can not be increased by co-perfusion with verapamil, indicating that absorption of metformin is not efficiently transported by P-

关键词： Metformin Intestinal permeability Single-pass intestinal perfusion P-glycoprotein RP-HPLC

Geographical Information System-Based Assessment of Ecological Security in changbai Mountain Region

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Journal of Mountain Science 2014年第1期11卷 86-97页

作者： LU Xing-chang ZHANG Ji-quan LI xiao-zhen School of Environment Northeast Normal University College of Geo-exploration Science & Technology Jilin University Anyang City Bureau of Agriculture

Ecological security defined as the creation of a condition where the physical surroundings of a community provide for the needs of its inhabitants without diminishing its natural stock,which is important for regional security and social *** recent years,land use patterns in the changbai Mountain region have changed significantly with intensive human activities,and consequently led to increasing problems in regional ecological *** on the Pressure-State-Impact-Response(PSIR) model and the mathematical method of catastrophe progression supported by geographical information system(GIS),the ecological security situation of the study area under land use and cover change(LUCC) was *** results indicated that the ecological security in changbai Mountain region varied nonlinearly,which got better from 1990 to 2000 but became worse from 2000 to 2007,the ecological security levels in changbai Mountain region were mainly medium and medium to low during the past 17 years,with higher values of Ecological Security Index(ESI) in the central region and lower values in the east and west,the ecological security situation was more serious in the settlements and river valleys,where the LUCC was most remarkable.

关键词： Ecological security Pressure-State-Impact-Response Land use and cover change Geographical Information System(GIS) Catastrophe progression changbai Mountain

Editorial for special issue on advanced materials for energy storage and conversion

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International Journal of Minerals,Metallurgy and Materials 2021年第10期28卷 1545-1548页

作者： Qiao-bao Zhang Yong-chang Liu xiao-bo Ji Department of Materials Science and Engineering College of MaterialsXiamen UniversityFujian 361005China Beijing Advanced Innovation Center for Materials Genome Engineering Institute for Advanced Materials and TechnologyState Key Laboratory for Advanced Metals and MaterialsUniversity of Science and Technology BeijingBeijing 100083China State Key Laboratory of Powder Metallurgy College of Chemistry and Chemical EngineeringCentral South UniversityChangsha 410083China

The ever-increasing environmental problems and energy challenges have called urgent demand for utilizing green,efficient,and sustainable energy,thus promoting the development of new technologies associated with energy storage and conversion *** a wealth of energy storage devices,Li/Na/K/Zn/Mg ion batteries,metal-air batteries,and lithium-sulfur/all-solid-state batteries together with supercapacitors as advanced power sources have attracted considerable interest due to their conspicuous merits of high energy density,long cycle life,and good rate capability.

关键词： energy utilizing lithium

Applications of nanomaterials in COVID-19 pandemic

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Rare Metals 2022年第1期41卷 1-13页

作者： Mei-Fang xiao chang Zeng Shao-Hui Li Fu-Lai Yuan Health Management Center Xiangya HospitalCentral South UniversityChangsha 410008China

The novel coronavirus 2019(COVID-19)pandemic represents one of the biggest global health threats in the last two decades,so researchers around the world are searching for solutions and treatments for *** the time of writing,there are no specific drugs that have demonstrated suitable effectiveness in treating *** current challenge involves designing tools for the prevention,rapid and accurate diagnosis,drug delivery,and effective treatment of this novel *** this short review,we discuss how nanotechnology offers new ways to combat COVID-19,and how nanomaterials can be applied to control the COVID-19 *** also summarize relevant studies regarding the use of nanomaterials for preventing viral spread,preparing vaccines,and diagnosing coronavirus,as well as studies that show how nanoparticles can be used as drug delivery systems for the treatment of viral *** on nanotechnology-based diagnosis,drug delivery,and antiviral therapy is currently in the early ***,the unique chemical properties of some nanomaterials highlight the broad prospect of nanomaterials in the future,and we propose that they will play an important role in the fight against COVID-19.

关键词： Coronaviruses COVID-19 Nanomaterials Viral control

MOLECULAR ENGINEERING STUDIES ON NONTHROMBOGENIC BIOMATERIALS——A NOVEL CLASS OF NONTHROMBOGENIC BIOMATERIALS WITH ZWITTERIONIC STRUCTURE OF CARBOXYBETAINES

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Chinese Journal of Polymer Science 2005年第1期23卷 93-102页

作者： JunZhou Yong-zhiQiu xiao-pengZang chang-wangPan QiangChen JianShen Si-congLin ResearchCenterofSurface＆InterfaceChemistryandEngineeringTechnology NanjingUniversityNanjing210093China

N,N-dimethyl-N-methacryloyloxyethyl-N-carboxyethyl ammonium(DMMCA)was graft-copolymerized onto thesurface of segmented poly(ether urethane)(SPEU)and PE *** carboxybetaine structure on SPEU and PE filmsurfaces was confirmed by ATR-FTIR,XPS and water contact angle *** the experiments with plateletadhesion and protein adhesion assay in vitro,the two materials studied,including poly-DMMCA gel,all show *** confirms once again that the zwitterionic molecular structure on the surfaces of materials isessential for improving their nonthrombogenicity and biocompatibility.

关键词： Nonthrombogenic biomaterials Zwitterionic biomaterial Carboxybetaine structure Surface graftcopolymerization.

Difluoroalkylation/Lactonization of Alkenes with BrCF_(2)CO_(2)K via Photoredox Catalysis:Access toα,α-Difluoro-γ-lactones

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Chinese Journal of Chemistry 2023年第21期41卷 2819-2824页

作者： Min Zhang Qiang Li Jin-Hong Lin Ji-chang xiao Key Laboratory of Organofluorine Chemistry Shanghai Institute of Organic ChemistryUniversity of Chinese Academy of SciencesChinese Academy of Sciences345 Lingling RoadShanghai200032 China Department of Chemistry Innovative Drug Research CenterShanghai UniversityShanghai200444 China

Due to its unique electronic properties,the difluoromethylene group(CF2)has served as a valuable unity in the design of biologically active ***γ-lactones display a broad range of biological properties,α,α-difluoro-γ-lactones may exhibit unexpected biological activities,and thus their synthesis has received increasing *** synthetic methods suffer from tedious multi-step processes,and very few effective methods have been reported ***,we describe the difunctionalization of alkenes with BrCF_(2)CO_(2)K under photoredox catalysis with the use of a boron-Lewis acid for the access toα,α-difluoro-γ-*** this transformation,the alkene substrates and the used reagents,including BrCF_(2)CO_(2)K and the boron-Lewis acid,PhB(OH)2 or BF3·THF,are cheap and widely *** efficiency and atom economy may make this protocol attractive.

关键词： Photoredox Catalysis Fluorine Lactones Alkenes

Long-term Visual Tracking: Review and Experimental Comparison

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Machine Intelligence Research 2022年第6期19卷 512-530页

作者： chang Liu xiao-Fan Chen Chun-Juan Bo Dong Wang School of Information and Communication Engineering Dalian University of TechnologyDalian 116024China Dalian Minzu University Dalian 116600China

As a fundamental task in computer vision,visual object tracking has received much attention in recent *** studies focus on short-term visual tracking which addresses shorter videos and always-visible ***,long-term visual tracking is much closer to practical applications with more complicated *** exists a longer duration such as minute-level or even hour-level in the long-term tracking task,and the task also needs to handle more frequent target disappearance and *** this paper,we provide a thorough review of long-term tracking,summarizing long-term tracking algorithms from two perspectives:framework architectures and utilization of intermediate tracking *** we provide a detailed description of existing benchmarks and corresponding evaluation ***,we conduct extensive experiments and analyse the performance of trackers on six benchmarks:VOTLT2018,VOTLT2019(2020/2021),OxUvA,LaSOT,TLP and the long-term subset of ***,we discuss the future prospects from multiple perspectives,including algorithm design and benchmark *** our knowledge,this is the first comprehensive survey for long-term visual object *** relevant content is available at https://***/wangdongdut/Long-term-Visual-Tracking.

关键词： Visual object tracking long-term tracking short-term tracking re-detection online update

Temperature dependency of VOCs release characteristics of asphalt materials under varying test conditions

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Journal of Traffic and Transportation Engineering(English Edition) 2022年第2期9卷 280-292页

作者： Xiwen chang Yue xiao Yongshuang Long Feng Wang Zhanping You State Key Laboratory of Silicate Materials for Architectures Wuhan University of TechnologyWuhan 430070China Hubei Provincial Academy of Building Research and Design Co. LtdWuhan 430071China Department of Civil and Environmental Engineering Michigan Technological UniversityHoughtonMI 49931USA

Asphalt pavement is increasingly used in paving and ***,the release of volatile organic compounds(VOCs)from asphalt harm both the environment and *** methods were applied to characterize the VOCs for better understanding and ***,asphalt VOCs have huge heating temperature dependency,which makes the asphalt VOCs’characterization *** this research,three kinds of heating conditions,thermal gravimetric(TG)analyzer,pyrolysis(PY)analyzer,and thermal desorber(TD),were compared to determine the temperature dependency of VOC release *** chromatography and mass spectrometer(GC-MS)were then coupled for VOC *** indicated that the TG heating condition can surely simulate the volatilization of VOCs from some asphalt that is not in contact with air(no oxygen)during the actual construction process,while PY and TD represent the substances released by the asphalt due to the boiling point at a certain temperature and under the actual construction process,*** components detected by TG heating condition are both large and small molecules,while PY and TD heating condition will detect large molecules or small molecules,*** VOC composition results under various heating conditions reflect the chemical reaction law of asphalt molecules in the heating *** heating asphalt binders to a higher temperature,macromolecular substances will gradually crack and oxidize into small molecular substances,sulfides and *** the increase of temperature,the change trend of VOC components under different conditions is different.

关键词： Asphalt materials Volatile organic compounds Thermal gravimetric analysis-mass spectrometer Pyrolysis-gas chromatography-mass spectrometer Thermal desorption-gas chromatography-mass spectrometer

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