土地利用变化对生态系统的结构和功能产生了深刻影响,改变生态系统产品与服务的提供能力对维持生态系统服务具有重要作用。基于Web of Science核心数据库,利用R包“bibliometrix”及VOSviewer计量可视化工具,对1992—2024年间土地利用...土地利用变化对生态系统的结构和功能产生了深刻影响,改变生态系统产品与服务的提供能力对维持生态系统服务具有重要作用。基于Web of Science核心数据库,利用R包“bibliometrix”及VOSviewer计量可视化工具,对1992—2024年间土地利用在生态系统服务价值评估中的发文现状、研究前沿及热点进行了全面梳理。结果表明:该领域的发文量整体呈现出上升趋势,年均发文量从7.15篇(1992—2005年)增加到749.00篇(2017—2024年)。其中,我国机构的发文量位居世界首位,相关研究主要发表在Ecosystem Services、Land Use Policy及Ecological Economics等高水平期刊上,具备较高的学术影响力,但仍有待提高。关键词聚类图谱以Ecosystem Services、Biodiversity、Management、Valuation、Land Use Change、Trade-Offs等为核心,研究内容主要集中在土地利用视角下的生物多样性保护等生态系统服务、生态系统服务价值的评估及其实际应用、土地利用变化动态与生态系统服务的权衡与协同三方面。同时,还系统梳理了土地利用与生态系统服务价值领域的研究现状、主题热点及演化趋势,阐明了土地利用与生态系统服务价值的研究体系。展开更多
A rapid and sensitive fluorescence labeling method was developed and validated for the microanalysis of a sulfated polysaccharide drug,namely propylene glycol alginate sodium sulfate(PSS), in rat plasma. Fluorescein i...A rapid and sensitive fluorescence labeling method was developed and validated for the microanalysis of a sulfated polysaccharide drug,namely propylene glycol alginate sodium sulfate(PSS), in rat plasma. Fluorescein isothiocyanate(FITC) was selected to label PSS, and 1, 6-diaminohexane was used to link PSS and FITC in order to prepare FITC-labeled PSS(F-PSS) through a reductive amination reaction. F-PSS was identified by UV-Vis, FT-IR and 1H-NMR spectrum. The cell stability and cytotoxicity of F-PSS were tested in Madin-Darby canine kidney(MDCK) cells. The results indicated that the labeling efficiency of F-PSS was 0.522% ± 0.0248% and the absolute bioavailability was 8.39%. F-PSS was stable in MDCK cells without obvious cytotoxicity. The method was sensitive and reliable; it showed a good linearity, precision, recovery and stability. The FITC labeling method can be applied to investigating the absorption and metabolism of PSS and other polysaccharides in biological samples.展开更多
文摘土地利用变化对生态系统的结构和功能产生了深刻影响,改变生态系统产品与服务的提供能力对维持生态系统服务具有重要作用。基于Web of Science核心数据库,利用R包“bibliometrix”及VOSviewer计量可视化工具,对1992—2024年间土地利用在生态系统服务价值评估中的发文现状、研究前沿及热点进行了全面梳理。结果表明:该领域的发文量整体呈现出上升趋势,年均发文量从7.15篇(1992—2005年)增加到749.00篇(2017—2024年)。其中,我国机构的发文量位居世界首位,相关研究主要发表在Ecosystem Services、Land Use Policy及Ecological Economics等高水平期刊上,具备较高的学术影响力,但仍有待提高。关键词聚类图谱以Ecosystem Services、Biodiversity、Management、Valuation、Land Use Change、Trade-Offs等为核心,研究内容主要集中在土地利用视角下的生物多样性保护等生态系统服务、生态系统服务价值的评估及其实际应用、土地利用变化动态与生态系统服务的权衡与协同三方面。同时,还系统梳理了土地利用与生态系统服务价值领域的研究现状、主题热点及演化趋势,阐明了土地利用与生态系统服务价值的研究体系。
基金supported in part by programs of Qingdao Science and Technology Project (11-2-3-73-jh)Shandong Science and Technology Project (2011GSF 11815)Special Fund for Marine Scientific Research in the Public Interest (201005024)
文摘A rapid and sensitive fluorescence labeling method was developed and validated for the microanalysis of a sulfated polysaccharide drug,namely propylene glycol alginate sodium sulfate(PSS), in rat plasma. Fluorescein isothiocyanate(FITC) was selected to label PSS, and 1, 6-diaminohexane was used to link PSS and FITC in order to prepare FITC-labeled PSS(F-PSS) through a reductive amination reaction. F-PSS was identified by UV-Vis, FT-IR and 1H-NMR spectrum. The cell stability and cytotoxicity of F-PSS were tested in Madin-Darby canine kidney(MDCK) cells. The results indicated that the labeling efficiency of F-PSS was 0.522% ± 0.0248% and the absolute bioavailability was 8.39%. F-PSS was stable in MDCK cells without obvious cytotoxicity. The method was sensitive and reliable; it showed a good linearity, precision, recovery and stability. The FITC labeling method can be applied to investigating the absorption and metabolism of PSS and other polysaccharides in biological samples.
