In the current settings of osteosarcoma research and drug screening,in vitro three-dimensional(3D)models,which overcome the limitations of traditional models,are favored.In in vitro 3D models,tumor microenvironment si...In the current settings of osteosarcoma research and drug screening,in vitro three-dimensional(3D)models,which overcome the limitations of traditional models,are favored.In in vitro 3D models,tumor microenvironment simulation,particularly of the mechanical microenvironment,is crucial for estimating the biological effects of a tumor.However,current in vitro osteosarcoma model construction is often limited to a single mechanical signal,which fails to simulate the diversity of osteosarcoma mechanical stimuli.In this study,we utilized embedded bioprinting technology and the multiple response properties of calcium ions in soft and hard stiffness systems with osteosarcoma cell biological functions to construct an integrated gradient biomechanical signal-tailored osteosarcoma model(IGBSTOM).We achieved this by printing a fibrinogen bioink containing calcium ions and osteosarcoma tumor spheroids within an extracellular matrix composed of methacryloylated alginate,methacryloylated gelatin,thrombin,and transglutaminase,which is rich in polysaccharides and proteins and exhibits self-healing properties.Our in vitro and in vivo studies showed that the IGBSTOM enhanced tumor stemness,proliferation,and migration,and successfully reproduced the nest-like structure of tumors,providing an in vitro research platform that is more similar to the natural tumor than the existing models.This study proposes a novel IGBSTOM construction and provides a new strategy for the clinical understanding of tumor development,drug screening,and exploration of drug resistance and metastasis mechanisms.展开更多
The economic benefits of transport infrastructure investment have been widely accepted.However,the varying influence of road transport development across vertical space has rarely been discussed.Taking Sichuan provinc...The economic benefits of transport infrastructure investment have been widely accepted.However,the varying influence of road transport development across vertical space has rarely been discussed.Taking Sichuan province in China as case study area where the landform is diverse and complex,administrative counties were categorized into 4 main types:plain counties,hill counties,mountain counties,and plateau counties.Using statistical data during 2006-2014,theperformanceofeconomic development and transport construction level in the four types of counties are discussed.Subsequently,the heterogeneous effect of each grade road on economy was calculated by local regression model(GWR).The results indicate that plain counties largely surpassed the other geomorphic counties in economic development level,while the gradient gap among them was on the decline.Similarly,distribution of transport infrastructure presented a decreasing trend from the low plain counties to high plateau counties.Regional imbalances were mainly reflected in the County road and Village road.Regarding the changes of regional gaps,National&Provincial roads and County roads were constantly expanding,whereas the disparity of Village road was slowly narrowing over time.Particularly noteworthy was the non-stationary economic influence of traffic factors across vertical gradients.On average,National&Provincial roads generated higher benefits in the high elevation regions than the lowlands.In contrast,County road and Village road were found to be more effective in promoting economic development in plains.With regard to local estimates of traffic factors,coefficients in mountain counties exhibited larger fluctuation ranges than other geomorphic units.The conclusions provide a basis for government decisionmaking in a more reasonable construction arrangement of road facilities and sustainable economic development.展开更多
Geothermal exploration and development in North Africa have advanced significantly,driven by the region's rich geothermal resources and rising energy demand.The countries of Mauritania,Morocco,Algeria,Tunisia,Liby...Geothermal exploration and development in North Africa have advanced significantly,driven by the region's rich geothermal resources and rising energy demand.The countries of Mauritania,Morocco,Algeria,Tunisia,Libya,and Egypt are located near tectonic plate boundaries(African and Eurasian plates),giving them substantial geothermal potential.Various exploration activities,including geological surveys and geophysical studies,have been conducted to assess geothermal reservoirs and identify suitable development sites.This article reviews the progress made in geothermal exploration across the region,highlighting the key activities undertaken to evaluate geothermal resources.It also explores how government policies have played a critical role either in fostering or in freezing geothermal development.The different conducted assessments such as analyzing geological structures,hydrothermal systems,and subsurface temperatures lead to identify suitable sites for geothermal development and improve the understanding of subsurface conditions and ongoing projects.Today,some countries in North Africa are positioning themselves to become important players in the global geothermal energy landscape,and with continued investment and concerted efforts,the region has the potential to emerge as a prominent player in the global geothermal energy landscape.展开更多
Since the“Twelfth Five-Year Plan”,global tidal energy,tidal current energy,wave energy,ocean thermal energy conversion(OTEC),and salinity gradient power technologies have experienced a new surge in development.China...Since the“Twelfth Five-Year Plan”,global tidal energy,tidal current energy,wave energy,ocean thermal energy conversion(OTEC),and salinity gradient power technologies have experienced a new surge in development.China has also been promoting marine energy development through technology research and development,demonstration projects,and industrial planning.Against the backdrop of developing the marine economy and building a strong maritime nation,the development of ocean energy is of great significance for actively and prudently advancing carbon peaking and carbon neutrality,boosting high-quality economic and social development,and gaining an edge in the new round of technological revolution.展开更多
The organization of the brain follows a topologi-cal hierarchy that changes dynamically during development.However,it remains unknown whether and how cognitive training administered over multiple years during develop-...The organization of the brain follows a topologi-cal hierarchy that changes dynamically during development.However,it remains unknown whether and how cognitive training administered over multiple years during develop-ment can modify this hierarchical topology.By measuring the brain and behavior of school children who had carried out abacus-based mental calculation(AMC)training for five years(starting from 7 years to 12 years old)in pre-training and post-training,we revealed the reshaping effect of long-term AMC intervention during development on the brain hierarchical topology.We observed the development-induced emergence of the default network,AMC training-promoted shifting,and regional changes in cortical gradi-ents.Moreover,the training-induced gradient changes were located in visual and somatomotor areas in association with the visuospatial/motor-imagery strategy.We found that gradient-based features can predict the math ability within groups.Our findings provide novel insights into the dynamic nature of network recruitment impacted by long-term cognitive training during development.展开更多
This study was designed to determine the effect of different sperm preparation treatments on yak sperm quality and in vitro embryo development.Frozen-thawed semen samples were treated using swim-up or percoll gradient...This study was designed to determine the effect of different sperm preparation treatments on yak sperm quality and in vitro embryo development.Frozen-thawed semen samples were treated using swim-up or percoll gradient centrifugation methods.Sperm concentration,progressive motility,recovery of motile sperm,membrane integrity,acrosome and chromatin integrity were scored and compared in recovered samples and controls.In addition,the effects of two sperm separation treatments on embryos capable of cleavage and in vitro development to the blastocyst stage were evaluated.Swim-up separated sperm showed a higher motility,while the concentration of spermatozoa recovered and percent recovery of motile sperm were higher with percoll gradient centrifugation separation.According to the optical and electron microscopies,swim-up produced higher percentage of sperm with intact plasma membrane and acrosome than percoll gradient centrifugation separation.However,there was no difference in the percentage of sperm with intact chromatin between two treatment groups.Cell numbers in the blastocysts of two groups were not different.The blastocyst rate was similar in both groups,whereas cleavage rate was higher when swim-up was used.展开更多
Methods for horizontal well spacing calculation in tight gas reservoirs are still adversely affected by the complexity of related control factors,such as strong reservoir heterogeneity and seepage mechanisms.In this s...Methods for horizontal well spacing calculation in tight gas reservoirs are still adversely affected by the complexity of related control factors,such as strong reservoir heterogeneity and seepage mechanisms.In this study,the stress sensitivity and threshold pressure gradient of various types of reservoirs are quantitatively evaluated through reservoir seepage experiments.On the basis of these experiments,a numerical simulation model(based on the special seepage mechanism)and an inverse dynamic reserve algorithm(with different equivalent drainage areas)were developed.The well spacing ranges of Classes I,II,and III wells in the Q gas field are determined to be 802–1,000,600–662,and 285–400 m,respectively,with their average ranges as 901,631,and 342.5 m,respectively.By considering both the pairs of parallel well groups and series well groups as examples,the reliability of the calculation results is verified.It is shown that the combination of the two models can reduce errors and provide accurate results.展开更多
Connectome mapping studies have documented a principal primary-to-transmodal gradient in the adult brain network,capturing a functional spectrum that ranges from perception and action to abstract cognition.However,how...Connectome mapping studies have documented a principal primary-to-transmodal gradient in the adult brain network,capturing a functional spectrum that ranges from perception and action to abstract cognition.However,how this gradient pattern develops and whether its development is linked to cognitive growth,topological reorganization,and gene expression profiles remain largely unknown.Using longitudinal resting-state functional magnetic resonance imaging data from 305 children(aged 6-14 years),we describe substantial changes in the primary-to-transmodal gradient between childhood and adolescence,including emergence as the principal gradient,expansion of global topography,and focal tuning in primary and default-mode regions.These gradient changes are mediated by developmental changes in network integration and segregation,and are associated with abstract processing functions such as working memory and expression levels of calcium ion regulated exocytosis and synaptic transmission-related genes.Our findings have implications for understanding connectome maturation principles in normal development and developmental disorders.展开更多
基金appreciate financial support from the National Key R&D Program of China(No.2022YFA1104600)2022 Lingang Laboratory“Seeking Outstanding Youth Program”Open Project(No.LGQS-202206-04)+3 种基金Shanghai Ninth People’s Hospital–Shanghai Jiao Tong University School of Medicine–Shanghai University of Science and Technology Cross-funded Collaborative Program(No.JYJC202233)the National Natural Science Foundation of China(No.82372377)Biomaterials and Regenerative Medicine Institute Cooperative Research Project by Shanghai Jiao Tong University School of Medicine(No.2022LHBO8),Shanghai Key Laboratory of Orthopaedic Implants,Department of Orthopaedics by Shanghai Ninth People’s Hospital–Shanghai Jiao Tong University School of Medicine(No.KFKT202206),the Key R&D Program of Jiangsu Province Social Development Project(No.BE2022708)the Project of Shanghai Science and Technology Commission(No.22015820100).
文摘In the current settings of osteosarcoma research and drug screening,in vitro three-dimensional(3D)models,which overcome the limitations of traditional models,are favored.In in vitro 3D models,tumor microenvironment simulation,particularly of the mechanical microenvironment,is crucial for estimating the biological effects of a tumor.However,current in vitro osteosarcoma model construction is often limited to a single mechanical signal,which fails to simulate the diversity of osteosarcoma mechanical stimuli.In this study,we utilized embedded bioprinting technology and the multiple response properties of calcium ions in soft and hard stiffness systems with osteosarcoma cell biological functions to construct an integrated gradient biomechanical signal-tailored osteosarcoma model(IGBSTOM).We achieved this by printing a fibrinogen bioink containing calcium ions and osteosarcoma tumor spheroids within an extracellular matrix composed of methacryloylated alginate,methacryloylated gelatin,thrombin,and transglutaminase,which is rich in polysaccharides and proteins and exhibits self-healing properties.Our in vitro and in vivo studies showed that the IGBSTOM enhanced tumor stemness,proliferation,and migration,and successfully reproduced the nest-like structure of tumors,providing an in vitro research platform that is more similar to the natural tumor than the existing models.This study proposes a novel IGBSTOM construction and provides a new strategy for the clinical understanding of tumor development,drug screening,and exploration of drug resistance and metastasis mechanisms.
基金supported by the National Natural Science Foundation of China (Grants No. 41571523 and 41661144038)the National Basic Research Program of China (973 Program) (Grant No. 2013CBA01808)the National Key Technology Research and Development Program of the Ministry of Science and Technology of China (Grant No. 2014BAC05B01)
文摘The economic benefits of transport infrastructure investment have been widely accepted.However,the varying influence of road transport development across vertical space has rarely been discussed.Taking Sichuan province in China as case study area where the landform is diverse and complex,administrative counties were categorized into 4 main types:plain counties,hill counties,mountain counties,and plateau counties.Using statistical data during 2006-2014,theperformanceofeconomic development and transport construction level in the four types of counties are discussed.Subsequently,the heterogeneous effect of each grade road on economy was calculated by local regression model(GWR).The results indicate that plain counties largely surpassed the other geomorphic counties in economic development level,while the gradient gap among them was on the decline.Similarly,distribution of transport infrastructure presented a decreasing trend from the low plain counties to high plateau counties.Regional imbalances were mainly reflected in the County road and Village road.Regarding the changes of regional gaps,National&Provincial roads and County roads were constantly expanding,whereas the disparity of Village road was slowly narrowing over time.Particularly noteworthy was the non-stationary economic influence of traffic factors across vertical gradients.On average,National&Provincial roads generated higher benefits in the high elevation regions than the lowlands.In contrast,County road and Village road were found to be more effective in promoting economic development in plains.With regard to local estimates of traffic factors,coefficients in mountain counties exhibited larger fluctuation ranges than other geomorphic units.The conclusions provide a basis for government decisionmaking in a more reasonable construction arrangement of road facilities and sustainable economic development.
文摘Geothermal exploration and development in North Africa have advanced significantly,driven by the region's rich geothermal resources and rising energy demand.The countries of Mauritania,Morocco,Algeria,Tunisia,Libya,and Egypt are located near tectonic plate boundaries(African and Eurasian plates),giving them substantial geothermal potential.Various exploration activities,including geological surveys and geophysical studies,have been conducted to assess geothermal reservoirs and identify suitable development sites.This article reviews the progress made in geothermal exploration across the region,highlighting the key activities undertaken to evaluate geothermal resources.It also explores how government policies have played a critical role either in fostering or in freezing geothermal development.The different conducted assessments such as analyzing geological structures,hydrothermal systems,and subsurface temperatures lead to identify suitable sites for geothermal development and improve the understanding of subsurface conditions and ongoing projects.Today,some countries in North Africa are positioning themselves to become important players in the global geothermal energy landscape,and with continued investment and concerted efforts,the region has the potential to emerge as a prominent player in the global geothermal energy landscape.
文摘Since the“Twelfth Five-Year Plan”,global tidal energy,tidal current energy,wave energy,ocean thermal energy conversion(OTEC),and salinity gradient power technologies have experienced a new surge in development.China has also been promoting marine energy development through technology research and development,demonstration projects,and industrial planning.Against the backdrop of developing the marine economy and building a strong maritime nation,the development of ocean energy is of great significance for actively and prudently advancing carbon peaking and carbon neutrality,boosting high-quality economic and social development,and gaining an edge in the new round of technological revolution.
基金supported by the National Natural Science Foundation of China(32071096 and 31270026)the National Social Science Foundation(17ZDA323)+3 种基金the STI 2030-Major Projects(2021ZD0200500)the Hong Kong Baptist University Research Committee Interdisciplinary Research Matching Scheme 2018/19(IRMS/18-19/SCI01)the Recruitment Program of Global Experts of Zhejiang Provincethe Start-up Funds for Leading Talents at Beijing Normal University and the National Basic Science Data Center“Chinese Data-sharing Warehouse for In-vivo Imaging Brain”(NBSDC-DB-15).
文摘The organization of the brain follows a topologi-cal hierarchy that changes dynamically during development.However,it remains unknown whether and how cognitive training administered over multiple years during develop-ment can modify this hierarchical topology.By measuring the brain and behavior of school children who had carried out abacus-based mental calculation(AMC)training for five years(starting from 7 years to 12 years old)in pre-training and post-training,we revealed the reshaping effect of long-term AMC intervention during development on the brain hierarchical topology.We observed the development-induced emergence of the default network,AMC training-promoted shifting,and regional changes in cortical gradi-ents.Moreover,the training-induced gradient changes were located in visual and somatomotor areas in association with the visuospatial/motor-imagery strategy.We found that gradient-based features can predict the math ability within groups.Our findings provide novel insights into the dynamic nature of network recruitment impacted by long-term cognitive training during development.
基金supported by the National Natural Science Foundation of China(30871903)the Fundamental Research Funds for the Gansu Universities,China(2011)
文摘This study was designed to determine the effect of different sperm preparation treatments on yak sperm quality and in vitro embryo development.Frozen-thawed semen samples were treated using swim-up or percoll gradient centrifugation methods.Sperm concentration,progressive motility,recovery of motile sperm,membrane integrity,acrosome and chromatin integrity were scored and compared in recovered samples and controls.In addition,the effects of two sperm separation treatments on embryos capable of cleavage and in vitro development to the blastocyst stage were evaluated.Swim-up separated sperm showed a higher motility,while the concentration of spermatozoa recovered and percent recovery of motile sperm were higher with percoll gradient centrifugation separation.According to the optical and electron microscopies,swim-up produced higher percentage of sperm with intact plasma membrane and acrosome than percoll gradient centrifugation separation.However,there was no difference in the percentage of sperm with intact chromatin between two treatment groups.Cell numbers in the blastocysts of two groups were not different.The blastocyst rate was similar in both groups,whereas cleavage rate was higher when swim-up was used.
基金the Major Science and Technology Project of Southwest Oil and Gas Field Company(2022ZD01-02).
文摘Methods for horizontal well spacing calculation in tight gas reservoirs are still adversely affected by the complexity of related control factors,such as strong reservoir heterogeneity and seepage mechanisms.In this study,the stress sensitivity and threshold pressure gradient of various types of reservoirs are quantitatively evaluated through reservoir seepage experiments.On the basis of these experiments,a numerical simulation model(based on the special seepage mechanism)and an inverse dynamic reserve algorithm(with different equivalent drainage areas)were developed.The well spacing ranges of Classes I,II,and III wells in the Q gas field are determined to be 802–1,000,600–662,and 285–400 m,respectively,with their average ranges as 901,631,and 342.5 m,respectively.By considering both the pairs of parallel well groups and series well groups as examples,the reliability of the calculation results is verified.It is shown that the combination of the two models can reduce errors and provide accurate results.
基金supported by the National Natural Science Foundation of China(31830034,82021004,81620108016,31221003,31521063,81671767,82071998,81971690,32130045,and 61761166004)Changjiang Scholar Professorship Award(T2015027)+3 种基金the National Key Research and Development Project of China(2018YFA0701402)Beijing Nova Program(Z191100001119023)the Beijing Brain Initiative of Beijing Municipal Science&Technology Commission(Z181100001518003)the Fundamental Research Funds for the Central Universities(2020NTST29)。
文摘Connectome mapping studies have documented a principal primary-to-transmodal gradient in the adult brain network,capturing a functional spectrum that ranges from perception and action to abstract cognition.However,how this gradient pattern develops and whether its development is linked to cognitive growth,topological reorganization,and gene expression profiles remain largely unknown.Using longitudinal resting-state functional magnetic resonance imaging data from 305 children(aged 6-14 years),we describe substantial changes in the primary-to-transmodal gradient between childhood and adolescence,including emergence as the principal gradient,expansion of global topography,and focal tuning in primary and default-mode regions.These gradient changes are mediated by developmental changes in network integration and segregation,and are associated with abstract processing functions such as working memory and expression levels of calcium ion regulated exocytosis and synaptic transmission-related genes.Our findings have implications for understanding connectome maturation principles in normal development and developmental disorders.
