Analyses of stable isotopes(C,O,H)in tree rings are increasingly important cross-disciplinary programs.The rapid development in this field documented in an increasing number of publications requires a comprehensive re...Analyses of stable isotopes(C,O,H)in tree rings are increasingly important cross-disciplinary programs.The rapid development in this field documented in an increasing number of publications requires a comprehensive review.This study includes a bibliometric analysis-based review to better understand research trends in tree ring stable isotope research.Overall,1475 publications were selected from the Web of Science Core Collection for 1974-2023.The findings are that:(1)numbers of annual publications and citations increased since 1974.From 1974 to 1980,there were around two relevant publications per year.However,from 2020 to 2022,this rose sharply to 109 publications per year.Likewise,average article citations were less than four per year before 1990,but were around four per article per year after 2000;(2)the major subjects using tree ring stable isotopes include forestry,geosciences,and environmental sciences,contributing to 42.5%of the total during 1974-2023;(3)the top three most productive institutions are the Chinese Academy of Sciences(423),the Swiss Federal Institute for Forest,Snow and Landscape Research(227),and the University of Arizona(204).These achievements result from strong collaborations;(4)review papers,for example,(Dawson et al.,Annu Rev Ecol Syst 33:507-559,2002)and(McCarroll and Loader,Quat Sci Rev 23:771-801,2004),are among the most cited,with more than 1000 citations;(5)tree ring stable isotope studies mainly focus on climatology and ecology,with atmospheric CO_(2) one of the most popular topics.Since 2010,precipitation and drought have received increasing attention.Based on this analysis,the research stages,key findings,debated issues,limitations and direc-tions for future research are summarized.This study serves as an important attempt to understand the progress on the use of stable isotopes in tree rings,providing scientific guid-ance for young researchers in this field.展开更多
With the introduction and wide application of extensive courses in recent years,their theoretical research and practical application have received more and more attention.In this paper,the current application and prac...With the introduction and wide application of extensive courses in recent years,their theoretical research and practical application have received more and more attention.In this paper,the current application and practice of the extensive courses at the elementary school level is studied through the integration of the theoretical concepts of extensive course and taking the practicals in the extensive courses of xx primary school as an example.展开更多
The massive conversion of resourceful biomass to carbon nanomaterials not only opens a new avenue to effective and economical disposal of biomass,but provides a possibility to produce highly valued functionalized carb...The massive conversion of resourceful biomass to carbon nanomaterials not only opens a new avenue to effective and economical disposal of biomass,but provides a possibility to produce highly valued functionalized carbon-based electrodes for energy storage and conversion systems.In this work,biomass is applied to a facile and scalable one-step pyrolysis method to prepare three-dimensional(3D)carbon nanotubes/mesoporous carbon architecture,which uses transition metal inorganic salts and melamine as initial precursors.The role of each employed component is investigated,and the electrochemical performance of the attained product is explored.Each component and precise regulation of their dosage is proven to be the key to successful conversion of biomass to the desired carbon nanomaterials.Owing to the unique 3D architecture and integration of individual merits of carbon nanotubes and mesoporous carbon,the as-synthesized carbon nanotubes/mesoporous carbon hybrid exhibits versatile application toward lithium-ion batteries and Zn-air batteries.Apparently,a significant guidance on effective conversion of biomass to functionalized carbon nanomaterials can be shown by this work.展开更多
Critical-sized bone defects caused by traumatic fractures,tumour resection and congenital malformation are unlikely to heal spontaneously.Bone tissue engineering is a promising strategy aimed at developing in vitro re...Critical-sized bone defects caused by traumatic fractures,tumour resection and congenital malformation are unlikely to heal spontaneously.Bone tissue engineering is a promising strategy aimed at developing in vitro replacements for bone transplantation and overcoming the limitations of natural bone grafts.In this study,we developed an innovative bone engineering scaffold based on gelatin methacrylate(GelMA)hydrogel,obtained via a two-step procedure:first,solid lipid nanoparticles(SLNs)were loaded with resveratrol(Res),a drug that can promote osteogenic differentiation and bone formation;these particles were then encapsulated at different concentrations(0.01%,0.02%,0.04%and 0.08%)in GelMA to obtain the final Res-SLNs/GelMA scaffolds.The effects of these scaffolds on osteogenic differentiation of bone marrow mesenchymal stem cells(BMSCs)and bone regeneration in rat cranial defects were evaluated using various characterization assays.Our in vitro and in vivo investigations demonstrated that the different Res-SLNs/GelMA scaffolds improved the osteogenic differentiation of BMSCs,with the ideally slow and steady release of Res;the optimal scaffold was 0.02 Res-SLNs/GelMA.Therefore,the 0.02 Res-SLNs/GelMA hydrogel is an appropriate release system for Res with good biocompatibility,osteoconduction and osteoinduction,thereby showing potential for application in bone tissue engineering.展开更多
基金This study was supported by the National Natural Science Foundation of China(Grant Number:42007407,42022059)the Sino-German mobility program(M-0393)+1 种基金the Key Research Program of the Institute of Geology and Geophysics(CAS Grant IGGCAS-201905)the CAS Youth Interdisciplinary Team(JCTD-2021-05).
文摘Analyses of stable isotopes(C,O,H)in tree rings are increasingly important cross-disciplinary programs.The rapid development in this field documented in an increasing number of publications requires a comprehensive review.This study includes a bibliometric analysis-based review to better understand research trends in tree ring stable isotope research.Overall,1475 publications were selected from the Web of Science Core Collection for 1974-2023.The findings are that:(1)numbers of annual publications and citations increased since 1974.From 1974 to 1980,there were around two relevant publications per year.However,from 2020 to 2022,this rose sharply to 109 publications per year.Likewise,average article citations were less than four per year before 1990,but were around four per article per year after 2000;(2)the major subjects using tree ring stable isotopes include forestry,geosciences,and environmental sciences,contributing to 42.5%of the total during 1974-2023;(3)the top three most productive institutions are the Chinese Academy of Sciences(423),the Swiss Federal Institute for Forest,Snow and Landscape Research(227),and the University of Arizona(204).These achievements result from strong collaborations;(4)review papers,for example,(Dawson et al.,Annu Rev Ecol Syst 33:507-559,2002)and(McCarroll and Loader,Quat Sci Rev 23:771-801,2004),are among the most cited,with more than 1000 citations;(5)tree ring stable isotope studies mainly focus on climatology and ecology,with atmospheric CO_(2) one of the most popular topics.Since 2010,precipitation and drought have received increasing attention.Based on this analysis,the research stages,key findings,debated issues,limitations and direc-tions for future research are summarized.This study serves as an important attempt to understand the progress on the use of stable isotopes in tree rings,providing scientific guid-ance for young researchers in this field.
文摘With the introduction and wide application of extensive courses in recent years,their theoretical research and practical application have received more and more attention.In this paper,the current application and practice of the extensive courses at the elementary school level is studied through the integration of the theoretical concepts of extensive course and taking the practicals in the extensive courses of xx primary school as an example.
基金financially supported by the National Key Research and Development Program of China(Grant No.2019YFC1907900)Science&Technology Talents Lifting Project of Hunan Province(Grant No.2022TJ-N16)the Scientific Research Fund of Hunan Provincial Education Department,China(Grant No.21A0392).
文摘The massive conversion of resourceful biomass to carbon nanomaterials not only opens a new avenue to effective and economical disposal of biomass,but provides a possibility to produce highly valued functionalized carbon-based electrodes for energy storage and conversion systems.In this work,biomass is applied to a facile and scalable one-step pyrolysis method to prepare three-dimensional(3D)carbon nanotubes/mesoporous carbon architecture,which uses transition metal inorganic salts and melamine as initial precursors.The role of each employed component is investigated,and the electrochemical performance of the attained product is explored.Each component and precise regulation of their dosage is proven to be the key to successful conversion of biomass to the desired carbon nanomaterials.Owing to the unique 3D architecture and integration of individual merits of carbon nanotubes and mesoporous carbon,the as-synthesized carbon nanotubes/mesoporous carbon hybrid exhibits versatile application toward lithium-ion batteries and Zn-air batteries.Apparently,a significant guidance on effective conversion of biomass to functionalized carbon nanomaterials can be shown by this work.
基金supported by the Natural Science Foundation of Anhui Province(Grant No.2008085QH362)Key Program of Anhui Educational Committee(Grant No.KJ2020ZD51)+2 种基金Translational Medicine Key Projects of Bengbu Medical College(Grant Nos.BYTM2019006 and BYTM 2019012)Scientific Research Innovation Team of Bengbu Medical College(Grant No.BYKC201910)512 Talents Development Project of Bengbu Medical College(Grant Nos.by51202302 and by51202309).
文摘Critical-sized bone defects caused by traumatic fractures,tumour resection and congenital malformation are unlikely to heal spontaneously.Bone tissue engineering is a promising strategy aimed at developing in vitro replacements for bone transplantation and overcoming the limitations of natural bone grafts.In this study,we developed an innovative bone engineering scaffold based on gelatin methacrylate(GelMA)hydrogel,obtained via a two-step procedure:first,solid lipid nanoparticles(SLNs)were loaded with resveratrol(Res),a drug that can promote osteogenic differentiation and bone formation;these particles were then encapsulated at different concentrations(0.01%,0.02%,0.04%and 0.08%)in GelMA to obtain the final Res-SLNs/GelMA scaffolds.The effects of these scaffolds on osteogenic differentiation of bone marrow mesenchymal stem cells(BMSCs)and bone regeneration in rat cranial defects were evaluated using various characterization assays.Our in vitro and in vivo investigations demonstrated that the different Res-SLNs/GelMA scaffolds improved the osteogenic differentiation of BMSCs,with the ideally slow and steady release of Res;the optimal scaffold was 0.02 Res-SLNs/GelMA.Therefore,the 0.02 Res-SLNs/GelMA hydrogel is an appropriate release system for Res with good biocompatibility,osteoconduction and osteoinduction,thereby showing potential for application in bone tissue engineering.
