Introduction:Stroke has been the leading cause of death in China for decades.This study described the trends in stroke mortality in China from 2004 to 2019.Methods:Data was obtained from the National Disease Surveilla...Introduction:Stroke has been the leading cause of death in China for decades.This study described the trends in stroke mortality in China from 2004 to 2019.Methods:Data was obtained from the National Disease Surveillance Point(DSP)system.A descriptive analysis was conducted.The adjusted mortality rate(AMR)and age-standardized mortality rate(ASMR)of stroke were calculated.Results:From 2004 to 2019,the ASMR substantially decreased,with a reduction of 39.8%,but the AMR stayed relatively stable.The mortality rate of stroke in rural areas was consistently higher than in urban areas.A geographical gradient in mortality of stroke was also apparent,with an increased rate in the western part of China and a decreased rate in the eastern part of China.In central China,the rate remained relatively stable.Conclusions:Although the ASMR of stroke continued to decline in China,the stagnant crude mortality rates suggested that China had not achieved sufficient decline to offset the demographic forces of population growth and ageing.More vigorous and effective prevention and treatment strategies are urgently needed to mitigate the disease burden of stroke in China,especially in areas with high stroke burden and limited resources.展开更多
Hydrocodes are necessary numerical tools in the fields of implosion and high-velocity impact,which often involve large deformations with changing-topology interfaces.It is very difficult for Lagrangian or Simplified A...Hydrocodes are necessary numerical tools in the fields of implosion and high-velocity impact,which often involve large deformations with changing-topology interfaces.It is very difficult for Lagrangian or Simplified Arbitrary Lagrangian-Eulerian(SALE)codes to tackle these kinds of large-deformation problems,so a stag-gered Multi-Material ALE(MMALE)code is developed in this paper,which is the explicit time-marching Lagrange plus remap type.We use the Moment Of Fluid(MOF)method to reconstruct the interfaces of multi-material cells and present an adaptive bisection method to search for the global minimum value of the nonlinear objective function.To keep the Lagrangian computations as long as possible,we develop a ro-bust rezoning method named as Combined Rezoning Method(CRM)to generate the convex,smooth grids for the large-deformation domain.Regarding the staggered remap phase,we use two methods to remap the variables of Lagrangian mesh to the rezoned one.One is the first-order intersection-based remapping method that doesn’t limit the distances between the rezoned and Lagrangian meshes,so it can be used in the applications of wide scope.The other one is the conservative second-order flux-based remapping method developed by Kucharika and Shashkov[22]that requires the rezoned element to locate in its adjacent old elements.Numerical results of triple point problem show that the result of first-order remapping method using ALE computations is gradually convergent to that of second-order remapping method using Eulerian computations with the decrease of rezoning,thereby telling us that MMALE computations should be performed as few as possible to reduce the errors of the interface reconstruction and the remapping.Numerical results provide a clear evidence of the robustness and the accuracy of this MMALE scheme,and that our MMALE code is powerful for the large-deformation problems.展开更多
文摘Introduction:Stroke has been the leading cause of death in China for decades.This study described the trends in stroke mortality in China from 2004 to 2019.Methods:Data was obtained from the National Disease Surveillance Point(DSP)system.A descriptive analysis was conducted.The adjusted mortality rate(AMR)and age-standardized mortality rate(ASMR)of stroke were calculated.Results:From 2004 to 2019,the ASMR substantially decreased,with a reduction of 39.8%,but the AMR stayed relatively stable.The mortality rate of stroke in rural areas was consistently higher than in urban areas.A geographical gradient in mortality of stroke was also apparent,with an increased rate in the western part of China and a decreased rate in the eastern part of China.In central China,the rate remained relatively stable.Conclusions:Although the ASMR of stroke continued to decline in China,the stagnant crude mortality rates suggested that China had not achieved sufficient decline to offset the demographic forces of population growth and ageing.More vigorous and effective prevention and treatment strategies are urgently needed to mitigate the disease burden of stroke in China,especially in areas with high stroke burden and limited resources.
基金This work was performed under the auspices of National Natural Science Founda-tion of China(No.11702030)NSAF(No.U1630247).
文摘Hydrocodes are necessary numerical tools in the fields of implosion and high-velocity impact,which often involve large deformations with changing-topology interfaces.It is very difficult for Lagrangian or Simplified Arbitrary Lagrangian-Eulerian(SALE)codes to tackle these kinds of large-deformation problems,so a stag-gered Multi-Material ALE(MMALE)code is developed in this paper,which is the explicit time-marching Lagrange plus remap type.We use the Moment Of Fluid(MOF)method to reconstruct the interfaces of multi-material cells and present an adaptive bisection method to search for the global minimum value of the nonlinear objective function.To keep the Lagrangian computations as long as possible,we develop a ro-bust rezoning method named as Combined Rezoning Method(CRM)to generate the convex,smooth grids for the large-deformation domain.Regarding the staggered remap phase,we use two methods to remap the variables of Lagrangian mesh to the rezoned one.One is the first-order intersection-based remapping method that doesn’t limit the distances between the rezoned and Lagrangian meshes,so it can be used in the applications of wide scope.The other one is the conservative second-order flux-based remapping method developed by Kucharika and Shashkov[22]that requires the rezoned element to locate in its adjacent old elements.Numerical results of triple point problem show that the result of first-order remapping method using ALE computations is gradually convergent to that of second-order remapping method using Eulerian computations with the decrease of rezoning,thereby telling us that MMALE computations should be performed as few as possible to reduce the errors of the interface reconstruction and the remapping.Numerical results provide a clear evidence of the robustness and the accuracy of this MMALE scheme,and that our MMALE code is powerful for the large-deformation problems.
