The failure wave has been observed propagating in glass under impact loading since 1991. It is a continuous fracture zone which may be associated with the damage accumulation process during the propagation of shock wa...The failure wave has been observed propagating in glass under impact loading since 1991. It is a continuous fracture zone which may be associated with the damage accumulation process during the propagation of shock waves. A progressive fracture model was proposed to describe the failure wave formation and propagation in shocked glass considering its heterogeneous meso-structures. The original and. nucleated microcracks will expand along the pores and other defects with concomitant dilation when shock loading is below the Hugoniot Elastic Limit. The governing equation of the failure wave is characterized by inelastic bulk strain with material damage and fracture. And the inelastic bulk strain consists of dilatant strain from nucleation and expansion of microcracks and condensed strain from the collapse of the original pores. Numerical simulation of the free surface velocity was performed and found in good agreement with planar impact experiments on K9 glass at China Academy of Engineering Physics. And the longitudinal, lateral and shear stress histories upon the arrival of the failure wave were predicted, which present the diminished shear strength and lost spall strength in the failed layer.展开更多
OBJECTIVE:To explore the effect of acupuncture treatment on cerebral ischaemia-reperfusion injury(CIRI)and reveal the underlying mechanism of the effect based on nuclear receptor coactivator 4(NCOA4)mediated ferritino...OBJECTIVE:To explore the effect of acupuncture treatment on cerebral ischaemia-reperfusion injury(CIRI)and reveal the underlying mechanism of the effect based on nuclear receptor coactivator 4(NCOA4)mediated ferritinophagy.METHODS:Sprague-Dawley male rats were divided into four groups:the sham group,model group,acupuncture group,and sham acupuncture group.After 2 h of middle cerebral artery occlusion(MCAO),reperfusion was performed for 24 h to induce CIRI.The rats were treated with acupuncture at the Neiguan(PC6)and Shuigou(GV26)acupoints.Their neurological function was evaluated by taking their Bederson scores at 2 h after ischaemia and 24 h after reperfusion.Triphenyltetrazolium chloride staining was applied to assess the cerebral infarct volume at 24 h after reperfusion.The malondialdehyde(MDA)and ferrous iron(Fe^(2+))levels were observed after 24 h of reperfusion using an assay kit.Western blotting was performed to detect the expression of NCOA4 and ferritin heavy chain 1(FTH1)at 24 h after reperfusion.Moreover,the colocalization of ferritin with neurons,NCOA4 with microtubule-associated protein 1 light chain 3(LC3),and NCOA4 with ferritin was visualized using immunofluorescence staining.RESULTS:Acupuncture significantly improved neurological function and decreased cerebral infarct volume in the acupuncture group.Following CIRI,the expression of NCOA4,LC3 and FTH1 was increased,which enhanced ferritinophagy and induced an inappropriate accumulation of Fe^(2+)and MDA in the ischaemic brain.However,acupuncture dramatically downregulated the expression of NCOA4,LC3 and FTH1,inhibited the overactivation of ferritinophagy,and decreased the levels of MDA and Fe^(2+).CONCLUSIONS:Acupuncture can inhibit NCOA4-mediated ferritinophagy and protect neurons against CIRI in a rat model.展开更多
基金National Natural Science Foundation of China(51731004,51671054)Fundamental Research Funds for the Central Universities in China(2242018K40108,2242018K40109)+1 种基金Natural Science Foundation of Jiangsu Province(BK20181285)Youth Research Fund Project of Anhui University of Technology。
基金Project supported by the National Natural Science Foundation of China (Nos.10272047 and 10376046).
文摘The failure wave has been observed propagating in glass under impact loading since 1991. It is a continuous fracture zone which may be associated with the damage accumulation process during the propagation of shock waves. A progressive fracture model was proposed to describe the failure wave formation and propagation in shocked glass considering its heterogeneous meso-structures. The original and. nucleated microcracks will expand along the pores and other defects with concomitant dilation when shock loading is below the Hugoniot Elastic Limit. The governing equation of the failure wave is characterized by inelastic bulk strain with material damage and fracture. And the inelastic bulk strain consists of dilatant strain from nucleation and expansion of microcracks and condensed strain from the collapse of the original pores. Numerical simulation of the free surface velocity was performed and found in good agreement with planar impact experiments on K9 glass at China Academy of Engineering Physics. And the longitudinal, lateral and shear stress histories upon the arrival of the failure wave were predicted, which present the diminished shear strength and lost spall strength in the failed layer.
基金the National Natural Science Foundation of China:Mechanism of Acupuncture in Extending Thrombolytic Time Window of Cerebral Infarction Based on Nuclear Receptor Coactivator 4 Mediated Ferritinophagy(No.82205238)National Natural Science Foundation of China:Exploring the Mechanism of Acupuncture Improving Thrombolytic Safety in Cerebral Infarction through the ERK1/2-mTOR Pathway Based on Autophagy Apoptosis Interaction(No.82074525)+1 种基金Natural Science Foundation of Jiangsu Province:Experimental Study on Acupuncture Regulation of Ferroptosis-NLRP3 Inflammasome Pathway to Reduce Hemorrhagic Transformation after Thrombolysis in Cerebral Infarction(No.BK20210689)Traditional Chinese Medicine Science and Technology Development Plan Project of Jiangsu Province:Clinical and Experimental Study on Acupuncture Improving the Safety of rt-PA Intravenous Thrombolysis in Cerebral Infarction(No.YB2020005)。
文摘OBJECTIVE:To explore the effect of acupuncture treatment on cerebral ischaemia-reperfusion injury(CIRI)and reveal the underlying mechanism of the effect based on nuclear receptor coactivator 4(NCOA4)mediated ferritinophagy.METHODS:Sprague-Dawley male rats were divided into four groups:the sham group,model group,acupuncture group,and sham acupuncture group.After 2 h of middle cerebral artery occlusion(MCAO),reperfusion was performed for 24 h to induce CIRI.The rats were treated with acupuncture at the Neiguan(PC6)and Shuigou(GV26)acupoints.Their neurological function was evaluated by taking their Bederson scores at 2 h after ischaemia and 24 h after reperfusion.Triphenyltetrazolium chloride staining was applied to assess the cerebral infarct volume at 24 h after reperfusion.The malondialdehyde(MDA)and ferrous iron(Fe^(2+))levels were observed after 24 h of reperfusion using an assay kit.Western blotting was performed to detect the expression of NCOA4 and ferritin heavy chain 1(FTH1)at 24 h after reperfusion.Moreover,the colocalization of ferritin with neurons,NCOA4 with microtubule-associated protein 1 light chain 3(LC3),and NCOA4 with ferritin was visualized using immunofluorescence staining.RESULTS:Acupuncture significantly improved neurological function and decreased cerebral infarct volume in the acupuncture group.Following CIRI,the expression of NCOA4,LC3 and FTH1 was increased,which enhanced ferritinophagy and induced an inappropriate accumulation of Fe^(2+)and MDA in the ischaemic brain.However,acupuncture dramatically downregulated the expression of NCOA4,LC3 and FTH1,inhibited the overactivation of ferritinophagy,and decreased the levels of MDA and Fe^(2+).CONCLUSIONS:Acupuncture can inhibit NCOA4-mediated ferritinophagy and protect neurons against CIRI in a rat model.
