Investigating the spatiotemporal evolution of vegetation and its response mechanisms to natural and anthropogenic elements is crucial for regional vegetation restoration and ecological preservation.The Mu Us Sandy Lan...Investigating the spatiotemporal evolution of vegetation and its response mechanisms to natural and anthropogenic elements is crucial for regional vegetation restoration and ecological preservation.The Mu Us Sandy Land(MUSL),which is situated in the semi-arid zone of northwestern China adjacent to the Loess Plateau,has been at the forefront of desertification and oasis formation over the past two millennia.This study is based on the synthesis of the Normalized Difference Vegetation Index(NDVI)data from MOD13A3 data in the MODIS(Moderate-Resolution Imaging Spectroradiometer)dataset(2002-2021)and climate data(temperature and precipitation)at annual and monthly scales from the National Earth System Science Data Center.A range of analytical methods,including univariate linear regression,Theil-Sen trend analysis and Mann-Kendall significance test,correlation analysis,residual analysis,and Hurst index,were used to explore the response mechanisms of the NDVI to climate change and human activities and to predict the future trends of the NDVI in the MUSL.The results showed that through the method of correlation analysis,in terms of both spatially averaged correlation coefficients and area proportion,the NDVI was positively correlated with temperature and precipitation in 97.59%and 96.51%of the study area,respectively,indicating that temperature has a greater impact on the NDVI than precipitation.Residual analysis quantified the contributions of climate change and human activities to the NDVI changes,revealing that climate change and human activities contribute up to 30.00%and 70.00%,respectively,suggesting that human activities predominantly affect the NDVI changes in the MUSL.The Hurst index was used to categorize the future trend of the NDVI into four main directions of development:continuous degradation(0.05%of the study area),degradation in the past but improvement in the future(54.45%),improvement in the past but degradation in the future(0.13%),and continuous improvement(45.36%).In more than 50.00%of the regions that have been degraded in the past but were expected to improve in the future,the NDVI was expected to exhibit a stable trend of anti-persistent improvement.These findings provide theoretical support for future ecological protection,planning,and the implementation of ecological engineering in the MUSL,and also offer a theoretical basis for the planning and execution of construction projects,environmental protection measures,and the sustainable development of vegetation.展开更多
BACKGROUND Macrophages play a crucial role in the tumor microenvironment,displaying remarkable plasticity that allows them to either suppress or promote tumor progression.Their polarization into M1 or M2 phenotypes co...BACKGROUND Macrophages play a crucial role in the tumor microenvironment,displaying remarkable plasticity that allows them to either suppress or promote tumor progression.Their polarization into M1 or M2 phenotypes could have significant prognostic implications,and manipulating this polarization may offer a novel approach to controlling colorectal neoplasms.AIM To evaluate the infiltration rates of M1 and M2 macrophages in colorectal neoplasia,specifically comparing cases with and without metalloproteinase mutations.Additionally,it sought to explore potential prognostic factors as-sociated with the disease.展开更多
Eco-geological vulnerability assessment is a significant research topic within the field of eco-geology,but it remains poorly studied.The Mu Us Sandy Land,located in the central part of the farming-pastoral ecotone in...Eco-geological vulnerability assessment is a significant research topic within the field of eco-geology,but it remains poorly studied.The Mu Us Sandy Land,located in the central part of the farming-pastoral ecotone in northern China,plays a critical role in maintaining the ecological security pattern in this region.However,this sandy land also faces severe sandy desertification and ecological degradation.This study conducted a regional eco-geological vulnerability assessment of the Mu Us Sandy Land using a comprehensive index evaluation method based on eco-geological theories and survey results.To construct an appropriate index system for the eco-geological vulnerability assessment of the Mu Us Sandy Land,the study considered the sandy land’s unique characteristics and identified 15 factors of five categories,namely geology,meteorology,soil,topography,and vegetation.The paper calculated the comprehensive weights of all the indices using the analytic hierarchy process(AHP)and the entropy weight method(EWM).Furthermore,it established the eco-geological vulnerability index(EGVI)and obtained the assessment results.The results showed that the eco-geological vulnerability of the Mu Us Sandy Land gradually intensifies from east to west,manifested as vulnerable eco-geological conditions overall.Specifically,extremely vulnerable zones are found in the northwestern and southeastern parts of the study area,highly vulnerable zones in the western and southern parts,moderately vulnerable zones in the central part,and slightly and potentially vulnerable zones in the eastern and southern parts.Areas with high spatial autocorrelations include the northern Uxin Banner-Otog Banner-Angsu Town area,the surrounding areas of Hongdunjie Town in the southeastern part of the study area,the Hongshiqiao Township-Xiaohaotu Township area,Otog Front Banner,and Bainijing Town,which should be prioritized in the ecological conservation and restoration.Additionally,the paper proposed suggestions for the ecological conservation and restoration of county-level administrative areas in the study area.Overall,the findings provide a valuable reference for the ecological conservation and restoration of the Mu Us Sandy Land and other desert areas in arid and semi-arid regions.展开更多
转座子是一类可以在基因组中不同遗传位点间移动的DNA序列,在其转移过程中有时会伴随自身拷贝数的增加。作为基因组的重要组成部分,转座子可以通过多种方式影响宿主基因及基因组的结构与功能,进而在宿主的演化过程中扮演重要角色。目前...转座子是一类可以在基因组中不同遗传位点间移动的DNA序列,在其转移过程中有时会伴随自身拷贝数的增加。作为基因组的重要组成部分,转座子可以通过多种方式影响宿主基因及基因组的结构与功能,进而在宿主的演化过程中扮演重要角色。目前依据转座过程中间体类型的不同可以将其分为I类转座子和II类转座子。Mutator超家族转座子是20世纪70年代在玉米(Zea may L.)中发现的一类特殊的转座子,其属于II类转座子,广泛存在于真核生物基因组中,包含遗传特征明晰可分的众多转座子家族。此外,该超家族转座子转座频率高,倾向于插入基因富含区及低拷贝序列区,可快速产生大量新的突变体,目前已被广泛应用于正向及反向遗传学研究。本文结合近年来相关研究结果,围绕Mutator超家族转座子的分类组成、结构特征、转座机制、插入偏好、靶位点重复序列以及玉米自主性MULEs元件展开综述,并对转座子研究面临的问题及未来研究方向进行了探讨,旨在与研究领域内的同行探讨相关研究的可能突破点、未来发展方向及可能产生的重大影响。展开更多
基金supported by the grants of "863" High-tech Program(No.2006AA10A106)the China National Fundamental Fund of Personnel Training(No.J0730649)supported by the open funds of the National Key Laboratory of Crop Genetic Improvement
基金funded by the Shaanxi Provincial Department of Science and Technology(2023JCYB449)the Yan'an University Project(YDBK2017-19)+1 种基金the Yan'an Science and Technology Bureau's List System Project(2023SLJBZ002)the Shaanxi Provincial Department of Education Natural Science Special Project(23JK0725,24JK0716).
文摘Investigating the spatiotemporal evolution of vegetation and its response mechanisms to natural and anthropogenic elements is crucial for regional vegetation restoration and ecological preservation.The Mu Us Sandy Land(MUSL),which is situated in the semi-arid zone of northwestern China adjacent to the Loess Plateau,has been at the forefront of desertification and oasis formation over the past two millennia.This study is based on the synthesis of the Normalized Difference Vegetation Index(NDVI)data from MOD13A3 data in the MODIS(Moderate-Resolution Imaging Spectroradiometer)dataset(2002-2021)and climate data(temperature and precipitation)at annual and monthly scales from the National Earth System Science Data Center.A range of analytical methods,including univariate linear regression,Theil-Sen trend analysis and Mann-Kendall significance test,correlation analysis,residual analysis,and Hurst index,were used to explore the response mechanisms of the NDVI to climate change and human activities and to predict the future trends of the NDVI in the MUSL.The results showed that through the method of correlation analysis,in terms of both spatially averaged correlation coefficients and area proportion,the NDVI was positively correlated with temperature and precipitation in 97.59%and 96.51%of the study area,respectively,indicating that temperature has a greater impact on the NDVI than precipitation.Residual analysis quantified the contributions of climate change and human activities to the NDVI changes,revealing that climate change and human activities contribute up to 30.00%and 70.00%,respectively,suggesting that human activities predominantly affect the NDVI changes in the MUSL.The Hurst index was used to categorize the future trend of the NDVI into four main directions of development:continuous degradation(0.05%of the study area),degradation in the past but improvement in the future(54.45%),improvement in the past but degradation in the future(0.13%),and continuous improvement(45.36%).In more than 50.00%of the regions that have been degraded in the past but were expected to improve in the future,the NDVI was expected to exhibit a stable trend of anti-persistent improvement.These findings provide theoretical support for future ecological protection,planning,and the implementation of ecological engineering in the MUSL,and also offer a theoretical basis for the planning and execution of construction projects,environmental protection measures,and the sustainable development of vegetation.
文摘BACKGROUND Macrophages play a crucial role in the tumor microenvironment,displaying remarkable plasticity that allows them to either suppress or promote tumor progression.Their polarization into M1 or M2 phenotypes could have significant prognostic implications,and manipulating this polarization may offer a novel approach to controlling colorectal neoplasms.AIM To evaluate the infiltration rates of M1 and M2 macrophages in colorectal neoplasia,specifically comparing cases with and without metalloproteinase mutations.Additionally,it sought to explore potential prognostic factors as-sociated with the disease.
基金This research was jointly supported by the project of the China Geological Survey(DD20242481)Key Laboratory of Airborne Geophysics and Remote Sensing Geology,MNR(2020YFL33)。
文摘Eco-geological vulnerability assessment is a significant research topic within the field of eco-geology,but it remains poorly studied.The Mu Us Sandy Land,located in the central part of the farming-pastoral ecotone in northern China,plays a critical role in maintaining the ecological security pattern in this region.However,this sandy land also faces severe sandy desertification and ecological degradation.This study conducted a regional eco-geological vulnerability assessment of the Mu Us Sandy Land using a comprehensive index evaluation method based on eco-geological theories and survey results.To construct an appropriate index system for the eco-geological vulnerability assessment of the Mu Us Sandy Land,the study considered the sandy land’s unique characteristics and identified 15 factors of five categories,namely geology,meteorology,soil,topography,and vegetation.The paper calculated the comprehensive weights of all the indices using the analytic hierarchy process(AHP)and the entropy weight method(EWM).Furthermore,it established the eco-geological vulnerability index(EGVI)and obtained the assessment results.The results showed that the eco-geological vulnerability of the Mu Us Sandy Land gradually intensifies from east to west,manifested as vulnerable eco-geological conditions overall.Specifically,extremely vulnerable zones are found in the northwestern and southeastern parts of the study area,highly vulnerable zones in the western and southern parts,moderately vulnerable zones in the central part,and slightly and potentially vulnerable zones in the eastern and southern parts.Areas with high spatial autocorrelations include the northern Uxin Banner-Otog Banner-Angsu Town area,the surrounding areas of Hongdunjie Town in the southeastern part of the study area,the Hongshiqiao Township-Xiaohaotu Township area,Otog Front Banner,and Bainijing Town,which should be prioritized in the ecological conservation and restoration.Additionally,the paper proposed suggestions for the ecological conservation and restoration of county-level administrative areas in the study area.Overall,the findings provide a valuable reference for the ecological conservation and restoration of the Mu Us Sandy Land and other desert areas in arid and semi-arid regions.
文摘转座子是一类可以在基因组中不同遗传位点间移动的DNA序列,在其转移过程中有时会伴随自身拷贝数的增加。作为基因组的重要组成部分,转座子可以通过多种方式影响宿主基因及基因组的结构与功能,进而在宿主的演化过程中扮演重要角色。目前依据转座过程中间体类型的不同可以将其分为I类转座子和II类转座子。Mutator超家族转座子是20世纪70年代在玉米(Zea may L.)中发现的一类特殊的转座子,其属于II类转座子,广泛存在于真核生物基因组中,包含遗传特征明晰可分的众多转座子家族。此外,该超家族转座子转座频率高,倾向于插入基因富含区及低拷贝序列区,可快速产生大量新的突变体,目前已被广泛应用于正向及反向遗传学研究。本文结合近年来相关研究结果,围绕Mutator超家族转座子的分类组成、结构特征、转座机制、插入偏好、靶位点重复序列以及玉米自主性MULEs元件展开综述,并对转座子研究面临的问题及未来研究方向进行了探讨,旨在与研究领域内的同行探讨相关研究的可能突破点、未来发展方向及可能产生的重大影响。
