Adult neurogenesis continuously produces new neurons critical for cognitive plasticity in adult rodents.While it is known transforming growth factor-βsignaling is important in embryonic neurogenesis,its role in postn...Adult neurogenesis continuously produces new neurons critical for cognitive plasticity in adult rodents.While it is known transforming growth factor-βsignaling is important in embryonic neurogenesis,its role in postnatal neurogenesis remains unclear.In this study,to define the precise role of transforming growth factor-βsignaling in postnatal neurogenesis at distinct stages of the neurogenic cascade both in vitro and in vivo,we developed two novel inducible and cell type-specific mouse models to specifically silence transforming growth factor-βsignaling in neural stem cells in(mGFAPcre-ALK5fl/fl-Ai9)or immature neuroblasts in(DCXcreERT2-ALK5fl/fl-Ai9).Our data showed that exogenous transforming growth factor-βtreatment led to inhibition of the proliferation of primary neural stem cells while stimulating their migration.These effects were abolished in activin-like kinase 5(ALK5)knockout primary neural stem cells.Consistent with this,inhibition of transforming growth factor-βsignaling with SB-431542 in wild-type neural stem cells stimulated proliferation while inhibited the migration of neural stem cells.Interestingly,deletion of transforming growth factor-βreceptor in neural stem cells in vivo inhibited the migration of postnatal born neurons in mGFAPcre-ALK5fl/fl-Ai9 mice,while abolishment of transforming growth factor-βsignaling in immature neuroblasts in DCXcreERT2-ALK5fl/fl-Ai9 mice did not affect the migration of these cells in the hippocampus.In summary,our data supports a dual role of transforming growth factor-βsignaling in the proliferation and migration of neural stem cells in vitro.Moreover,our data provides novel insights on cell type-specific-dependent requirements of transforming growth factor-βsignaling on neural stem cell proliferation and migration in vivo.展开更多
This research conducts a comprehensive experimental study of the entire filling system process at the Weishan Lake Rare Earth Mine(WSLREM)in Shandong Province,encompassing tailings thickening,feeding,slurry preparatio...This research conducts a comprehensive experimental study of the entire filling system process at the Weishan Lake Rare Earth Mine(WSLREM)in Shandong Province,encompassing tailings thickening,feeding,slurry preparation,and pipeline transportation.It proposes a complete and efficient upgrade solution for an intelligent paste filling system.The results show that the F1 flocculant was selected to prepare a flocculant solution with a solution concentration of 0.1%.The unit consumption is set to 25 g·t^(-1),and the flocculation and sedimentation effects are optimal when the mass concentration is 15%,with an underflow concentration of 62%.The selection experiment of cementitious material shows that the effect of using new cementitious material is better than that of traditional 32.5R Portland cement.At the same time,rheological experiments on the filling slurry were carried out,and the filling transportation pressure was studied by combining theoretical calculations with numerical simulations.The research results have guiding significance for the debugging of filling pumps and the selection of a filling pipeline.After the application of industrial transformation,the underflow concentration of the sand silo was 64%–66%,the slurry concentration was 68%–72%,the addition range of the cementing material was 1∶16–1∶4,and the filling capacity was 40–60 m^(3)·h^(-1).The intelligent upgrade and transformation of the filling system have yielded remarkable results,providing significant reference value for the intelligent filling transformation of similar mines.展开更多
In-situ tensile tests were conducted on a chemically corroded third-generation single-crystal superalloy DD9 at 980 and 1100℃.The phase transformation in the surface areas during the tensile process was analyzed usin...In-situ tensile tests were conducted on a chemically corroded third-generation single-crystal superalloy DD9 at 980 and 1100℃.The phase transformation in the surface areas during the tensile process was analyzed using field emission scanning electron microscope,energy dispersive X-ray spectroscope,electron probe X-ray microanalysis,and transmission electron microscope.The phase transformation mechanism on the surface and the influence mechanism were studied through observation and dynamic calculation.During tensile tests at elevated temperatures,chemical corrosion promotes the precipitation of topologically close-packed(tcp)μphase andσphase on the alloy surface.Both the precipitation amount and size of these two phases on the surface at 1100℃are greater than those at 980℃.The precipitation of tcp phase on the alloy surface results in the formation of an influence layer on the surface area,and the distribution characteristics of alloying elements are significantly different from those of the substrate.The depth of the influence layer at 1100℃is greater than that at 980℃.The precipitation of tcp phase prompts the phase transition fromγphase toγ′phase around the tcp phase.展开更多
基金supported by NIH grants,Nos.R01NS125074,R01AG083164,R01NS107365,and R21NS127177(to YL),1F31NS129204-01A1(to KW)and Albert Ryan Fellowship(to KW).
文摘Adult neurogenesis continuously produces new neurons critical for cognitive plasticity in adult rodents.While it is known transforming growth factor-βsignaling is important in embryonic neurogenesis,its role in postnatal neurogenesis remains unclear.In this study,to define the precise role of transforming growth factor-βsignaling in postnatal neurogenesis at distinct stages of the neurogenic cascade both in vitro and in vivo,we developed two novel inducible and cell type-specific mouse models to specifically silence transforming growth factor-βsignaling in neural stem cells in(mGFAPcre-ALK5fl/fl-Ai9)or immature neuroblasts in(DCXcreERT2-ALK5fl/fl-Ai9).Our data showed that exogenous transforming growth factor-βtreatment led to inhibition of the proliferation of primary neural stem cells while stimulating their migration.These effects were abolished in activin-like kinase 5(ALK5)knockout primary neural stem cells.Consistent with this,inhibition of transforming growth factor-βsignaling with SB-431542 in wild-type neural stem cells stimulated proliferation while inhibited the migration of neural stem cells.Interestingly,deletion of transforming growth factor-βreceptor in neural stem cells in vivo inhibited the migration of postnatal born neurons in mGFAPcre-ALK5fl/fl-Ai9 mice,while abolishment of transforming growth factor-βsignaling in immature neuroblasts in DCXcreERT2-ALK5fl/fl-Ai9 mice did not affect the migration of these cells in the hippocampus.In summary,our data supports a dual role of transforming growth factor-βsignaling in the proliferation and migration of neural stem cells in vitro.Moreover,our data provides novel insights on cell type-specific-dependent requirements of transforming growth factor-βsignaling on neural stem cell proliferation and migration in vivo.
基金Supported by the National Natural Science Foundation of China(52004152)Shandong Provincial Natural Science Foundation(ZR2024ME006,ZR2023QE133,ZR2020QE100)+2 种基金Small and Medium-sized Technology Enterprises in Shandong Province(2022TSGC2077)Shandong College Youth Science and Technology Support Program(2023KJ149)National Key Laboratory Open Project Open Fund(2023-JSKSSYS-06)。
文摘This research conducts a comprehensive experimental study of the entire filling system process at the Weishan Lake Rare Earth Mine(WSLREM)in Shandong Province,encompassing tailings thickening,feeding,slurry preparation,and pipeline transportation.It proposes a complete and efficient upgrade solution for an intelligent paste filling system.The results show that the F1 flocculant was selected to prepare a flocculant solution with a solution concentration of 0.1%.The unit consumption is set to 25 g·t^(-1),and the flocculation and sedimentation effects are optimal when the mass concentration is 15%,with an underflow concentration of 62%.The selection experiment of cementitious material shows that the effect of using new cementitious material is better than that of traditional 32.5R Portland cement.At the same time,rheological experiments on the filling slurry were carried out,and the filling transportation pressure was studied by combining theoretical calculations with numerical simulations.The research results have guiding significance for the debugging of filling pumps and the selection of a filling pipeline.After the application of industrial transformation,the underflow concentration of the sand silo was 64%–66%,the slurry concentration was 68%–72%,the addition range of the cementing material was 1∶16–1∶4,and the filling capacity was 40–60 m^(3)·h^(-1).The intelligent upgrade and transformation of the filling system have yielded remarkable results,providing significant reference value for the intelligent filling transformation of similar mines.
文摘In-situ tensile tests were conducted on a chemically corroded third-generation single-crystal superalloy DD9 at 980 and 1100℃.The phase transformation in the surface areas during the tensile process was analyzed using field emission scanning electron microscope,energy dispersive X-ray spectroscope,electron probe X-ray microanalysis,and transmission electron microscope.The phase transformation mechanism on the surface and the influence mechanism were studied through observation and dynamic calculation.During tensile tests at elevated temperatures,chemical corrosion promotes the precipitation of topologically close-packed(tcp)μphase andσphase on the alloy surface.Both the precipitation amount and size of these two phases on the surface at 1100℃are greater than those at 980℃.The precipitation of tcp phase on the alloy surface results in the formation of an influence layer on the surface area,and the distribution characteristics of alloying elements are significantly different from those of the substrate.The depth of the influence layer at 1100℃is greater than that at 980℃.The precipitation of tcp phase prompts the phase transition fromγphase toγ′phase around the tcp phase.
