In the shaping process of cross wedge rolling（CWR）, metal undergoes a complex microstructural evolution, which affects the quality and mechanical properties of the product. Through secondary development of the DEFOR...In the shaping process of cross wedge rolling（CWR）, metal undergoes a complex microstructural evolution, which affects the quality and mechanical properties of the product. Through secondary development of the DEFORM-3D software, we developed a rigid plastic finite element model for a CWR-processed rear axle tube, coupled with thermomechanical and microstructural aspects of workpieces. Using the developed model, we investigated the microstructural evolution of the CWR process. Also, the influence of numerous parameters, including the initial temperature of workpieces, the roll speed, the forming angle, and the spreading angle, on the grain size and the grain-size uniformity of the rolled workpieces was analyzed. The numerical simulation was verified through rolling and metallographic experiments. Good agreement was obtained between the calculated and experimental results, which demonstrated the reliability of the model constructed in this work.展开更多
SARS-CoV-2 induced marked lymphopenia in severe patients with COVID-19.However,whether lymphocytes are targets of viral infection is yet to be determined,although SARS-CoV-2 RNA or antigen has been identified in T cel...SARS-CoV-2 induced marked lymphopenia in severe patients with COVID-19.However,whether lymphocytes are targets of viral infection is yet to be determined,although SARS-CoV-2 RNA or antigen has been identified in T cells from patients.Here,we confirmed that SARS-CoV-2 viral antigen could be detected in patient peripheral blood cells(PBCs)or postmortem lung T cells,and the infectious virus could also be detected from viral antigen-positive PBCs.We next prove that SARS-CoV-2 infects T lymphocytes,preferably activated CD4+T cells in vitro.Upon infection,viral RNA,subgenomic RNA,viral protein or viral particle can be detected in the T cells.Furthermore,we show that the infection is spike-ACE2/TMPRSS2-independent through using ACE2 knockdown or receptor blocking experiments.Next,we demonstrate that viral antigen-positive T cells from patient undergone pronounced apoptosis.In vitro infection of T cells induced cell death that is likely in mitochondria ROS-HIF-1a-dependent pathways.Finally,we demonstrated that LFA-1,the protein exclusively expresses in multiple leukocytes,is more likely the entry molecule that mediated SARS-CoV-2 infection in T cells,compared to a list of other known receptors.Collectively,this work confirmed a SARS-CoV-2 infection of T cells,in a spike-ACE2-independent manner,which shed novel insights into the underlying mechanisms of SARS-CoV2-induced lymphopenia in COVID-19 patients.展开更多
基金support given by the National Natural Science Foundation of China (No.51505026)
文摘In the shaping process of cross wedge rolling（CWR）, metal undergoes a complex microstructural evolution, which affects the quality and mechanical properties of the product. Through secondary development of the DEFORM-3D software, we developed a rigid plastic finite element model for a CWR-processed rear axle tube, coupled with thermomechanical and microstructural aspects of workpieces. Using the developed model, we investigated the microstructural evolution of the CWR process. Also, the influence of numerous parameters, including the initial temperature of workpieces, the roll speed, the forming angle, and the spreading angle, on the grain size and the grain-size uniformity of the rolled workpieces was analyzed. The numerical simulation was verified through rolling and metallographic experiments. Good agreement was obtained between the calculated and experimental results, which demonstrated the reliability of the model constructed in this work.
基金the Natural Science Foundation of China(excellent scholars 81822028,82041013,and 81772199 to P.Z.,and 81974456 and 82170081 to H.L.Z.)Strategic Priority Research Program of the CAS(grant number XDB29010204)to P.Z.
文摘SARS-CoV-2 induced marked lymphopenia in severe patients with COVID-19.However,whether lymphocytes are targets of viral infection is yet to be determined,although SARS-CoV-2 RNA or antigen has been identified in T cells from patients.Here,we confirmed that SARS-CoV-2 viral antigen could be detected in patient peripheral blood cells(PBCs)or postmortem lung T cells,and the infectious virus could also be detected from viral antigen-positive PBCs.We next prove that SARS-CoV-2 infects T lymphocytes,preferably activated CD4+T cells in vitro.Upon infection,viral RNA,subgenomic RNA,viral protein or viral particle can be detected in the T cells.Furthermore,we show that the infection is spike-ACE2/TMPRSS2-independent through using ACE2 knockdown or receptor blocking experiments.Next,we demonstrate that viral antigen-positive T cells from patient undergone pronounced apoptosis.In vitro infection of T cells induced cell death that is likely in mitochondria ROS-HIF-1a-dependent pathways.Finally,we demonstrated that LFA-1,the protein exclusively expresses in multiple leukocytes,is more likely the entry molecule that mediated SARS-CoV-2 infection in T cells,compared to a list of other known receptors.Collectively,this work confirmed a SARS-CoV-2 infection of T cells,in a spike-ACE2-independent manner,which shed novel insights into the underlying mechanisms of SARS-CoV2-induced lymphopenia in COVID-19 patients.
