Grasslands,one of the major terrestrial ecosystems,are essential for the maintenance of ecological and production functions;however,they are undergoing extensive degradation.The development and cutting-edge exploratio...Grasslands,one of the major terrestrial ecosystems,are essential for the maintenance of ecological and production functions;however,they are undergoing extensive degradation.The development and cutting-edge explorations in grassland science are critical to addressing challenges such as climate change and the increasing influence of human activities.To identify research trends in grassland science,latent Dirichlet allocation(LDA)topic modelling was used to conduct an automated content analysis on 123,829 papers available on Web of Science Core Collection from 1900 to 2020.Results from this analysis showed that grassland research has become increasing multidisciplinary,accompanied by a pronounced reduction in the relative frequency of traditional production-oriented research and an increase in the themes focusing on ecological functions and modern technologies.Changes in research activities have been uneven globally,with a significant increase in the number of publications in China and Brazil,which probably reflects an increased support from various governmental agencies in these countries.Additionally,in 2019,China surpassed the United States in terms of the total number of publications.Further,this study identified important topics and emerging challenges in grassland research,such as biodiversity conservation,climate changes,and genetic considerations.Comprehensive improvement of education,research,global cooperation,and funding strategies will be necessary to promote grassland science research on frontier themes and to effectively address the social and environmental challenges in the new era.展开更多
Neural stem cells,which are capable of multi-potential differentiation and self-renewal,have recently been shown to have clinical potential for repairing central nervous system tissue damage.However,the theme trends a...Neural stem cells,which are capable of multi-potential differentiation and self-renewal,have recently been shown to have clinical potential for repairing central nervous system tissue damage.However,the theme trends and knowledge structures for human neural stem cells have not yet been studied bibliometrically.In this study,we retrieved 2742 articles from the PubMed database from 2013 to 2018 using "Neural Stem Cells" as the retrieval word.Co-word analysis was conducted to statistically quantify the characteristics and popular themes of human neural stem cell-related studies.Bibliographic data matrices were generated with the Bibliographic Item Co-Occurrence Matrix Builder.We identified 78 high-frequency Medical Subject Heading(MeSH)terms.A visual matrix was built with the repeated bisection method in gCLUTO software.A social network analysis network was generated with Ucinet 6.0 software and GraphPad Prism 5 software.The analyses demonstrated that in the 6-year period,hot topics were clustered into five categories.As suggested by the constructed strategic diagram,studies related to cytology and physiology were well-developed,whereas those related to neural stem cell applications,tissue engineering,metabolism and cell signaling,and neural stem cell pathology and virology remained immature.Neural stem cell therapy for stroke and Parkinson’s disease,the genetics of microRNAs and brain neoplasms,as well as neuroprotective agents,Zika virus,Notch receptor,neural crest and embryonic stem cells were identified as emerging hot spots.These undeveloped themes and popular topics are potential points of focus for new studies on human neural stem cells.展开更多
文摘Grasslands,one of the major terrestrial ecosystems,are essential for the maintenance of ecological and production functions;however,they are undergoing extensive degradation.The development and cutting-edge explorations in grassland science are critical to addressing challenges such as climate change and the increasing influence of human activities.To identify research trends in grassland science,latent Dirichlet allocation(LDA)topic modelling was used to conduct an automated content analysis on 123,829 papers available on Web of Science Core Collection from 1900 to 2020.Results from this analysis showed that grassland research has become increasing multidisciplinary,accompanied by a pronounced reduction in the relative frequency of traditional production-oriented research and an increase in the themes focusing on ecological functions and modern technologies.Changes in research activities have been uneven globally,with a significant increase in the number of publications in China and Brazil,which probably reflects an increased support from various governmental agencies in these countries.Additionally,in 2019,China surpassed the United States in terms of the total number of publications.Further,this study identified important topics and emerging challenges in grassland research,such as biodiversity conservation,climate changes,and genetic considerations.Comprehensive improvement of education,research,global cooperation,and funding strategies will be necessary to promote grassland science research on frontier themes and to effectively address the social and environmental challenges in the new era.
基金supported by the National Natural Science Foundation of China,No.81471308(to JL)the Stem Cell Clinical Research Project in China,No.CMR-20161129-1003(to JL)the Innovation Technology Funding of Dalian in China,No.2018J11CY025(to JL)
文摘Neural stem cells,which are capable of multi-potential differentiation and self-renewal,have recently been shown to have clinical potential for repairing central nervous system tissue damage.However,the theme trends and knowledge structures for human neural stem cells have not yet been studied bibliometrically.In this study,we retrieved 2742 articles from the PubMed database from 2013 to 2018 using "Neural Stem Cells" as the retrieval word.Co-word analysis was conducted to statistically quantify the characteristics and popular themes of human neural stem cell-related studies.Bibliographic data matrices were generated with the Bibliographic Item Co-Occurrence Matrix Builder.We identified 78 high-frequency Medical Subject Heading(MeSH)terms.A visual matrix was built with the repeated bisection method in gCLUTO software.A social network analysis network was generated with Ucinet 6.0 software and GraphPad Prism 5 software.The analyses demonstrated that in the 6-year period,hot topics were clustered into five categories.As suggested by the constructed strategic diagram,studies related to cytology and physiology were well-developed,whereas those related to neural stem cell applications,tissue engineering,metabolism and cell signaling,and neural stem cell pathology and virology remained immature.Neural stem cell therapy for stroke and Parkinson’s disease,the genetics of microRNAs and brain neoplasms,as well as neuroprotective agents,Zika virus,Notch receptor,neural crest and embryonic stem cells were identified as emerging hot spots.These undeveloped themes and popular topics are potential points of focus for new studies on human neural stem cells.
