AIM： To explore if ischemic preconditioning （IPC） can enhance the survival of retinal ganglion cells （RGCs） after optic nerve axotomy. METHODS： Twenty-four hours prior to retinal ischemia 60min or axotomy, IPC ...AIM： To explore if ischemic preconditioning （IPC） can enhance the survival of retinal ganglion cells （RGCs） after optic nerve axotomy. METHODS： Twenty-four hours prior to retinal ischemia 60min or axotomy, IPC was applied for ten minutes in groups of （n=72） animals. The survival of RGCs, the cellular expression of heat shock protein 27 （HSP27） and heat shock protein 70 （HSP70） and the numbers of retinal microglia in the different groups were quantified at 7 and 14d post-injury. The cellular expression of HSP27 and HSP70 and changes in the numbers of retinal microglia were quantified to detect the possible mechanism of the protection of the IPC. RESULTS： Ten minutes of IPC promoted RGC survival in both the optic nerve injury （IPC-ONT） and the retinal ischemia 60min （IPC-IR60） groups, examined at 7d and 14d post-injury. Microglial proliferation showed little correlation with the extent of benefit effects of IPC on the rescue of RGCs. The number of HSP27-positive RGCs was significantly higher in the IPC-ONT group than in the sham IPC-ONT group, although the percentage of HSP27-positive RGCs did not significantly differ between groups. For the IPC-IR60 group, neither the number nor the percentage ofthe HSP27-positive RGCs differed significantly between the IPC and the sham-operated groups. The number of HSP70-positive RGCs was significantly higher for both the IPC-ONT and the IPC-IR60 experimental groups, but the percentages did not differ. CONCLUSION： The induction of IPC enhances the survival of RGCs against both axotomy and retinal ischemia.展开更多
The preconditioned density-based conjugate heat transfer(CHT)algorithm was used to investigate the heat transfer characteristics of a cooled turbine vane.Fluid domain provided boundary heat flux for solid domain and o...The preconditioned density-based conjugate heat transfer(CHT)algorithm was used to investigate the heat transfer characteristics of a cooled turbine vane.Fluid domain provided boundary heat flux for solid domain and obtained boundary temperature from it for the coupling strategy.The governing equations were solved by the preconditioned density-based finite-volume method,with preconditioning matrix,improved Abu-Gharmam Shaw(AGS)transition model,matrix dissipation scheme and four kinds of turbulence models.The grid system is multi-block structured grids for fluid domain and unstructured grids for solid domain,with full-matched grids at the fluid-solid interfaces.The effects of turbulence model,outlet Mach number,outlet Reynolds number,inlet turbulence intensity and the temperature ratio of blade surface/gas on the local heat transfer performance were studied.Results indicate that the k-o shear-stress transport(SST)and AGS model can predict the conjugate heat transfer better than others.The Mach number and Reynolds number have relatively obvious influences on the heat transfer,while the turbulence intensity and temperature ratio only have slight influences.Comparisons with experimental data demonstrate the applicability and accuracy of the numerical algorithm.展开更多
BACKGROUND: Ischemic preconditioning (IPC) is a strategy to reduce ischemia-reperfusion (I/R) injury. The protective effect of remote ischemic preconditioning (RIPC) on liver I/R injury is not clear. This study aimed ...BACKGROUND: Ischemic preconditioning (IPC) is a strategy to reduce ischemia-reperfusion (I/R) injury. The protective effect of remote ischemic preconditioning (RIPC) on liver I/R injury is not clear. This study aimed to investigate the roles of RIPC in liver I/R in fatty liver rats and the involvement of endothelial nitric oxide synthase-nitric oxide (eNOS-NO) pathway and microRNA expressions in this process. METHODS: A total of 32 fatty rats were randomly divided into the sham group, I/R group, RIPC group and RIPC+I/R group. Serum alanine aminotransferase (ALT), aspartate aminotransferase (AST) and nitric oxide (NO) were measured. Hematoxylin-eosin staining was used to observe histological changes of liver tissues, TUNEL to detect hepatocyte apoptosis, and immunohistochemistry assay to detect heat shock protein 70 (HSP70) expression. Western blotting was used to detect liver inducible NOS (iNOS) and eNOS protein levels and realtime quantitative polymerase chain reaction to detect miR-34a, miR-122 and miR-27b expressions. RESULTS: Compared with the sham and RIPC groups, serum ALT, AST and iNOS in liver tissue were significantly higher in other two groups, while serum NO and eNOS in liver tissue were lower, and varying degrees of edema, degeneration and inflammatory cell infiltration were found. Cell apoptosis number was slightly lower in the RIPC+I/R group than that in I/R group. Compared with the sham group, HSP70 expressions were significantly increased in other three groups (all P<0.05). Compared with the sham and RIPC groups, elevated miR-34a expressions were found in I/R and RIPC+I/R groups (P<0.05). MiR-122 and miR-27b were found significantly decreased in I/R and RIPC+I/R groups compared with the sham and RIPC groups (all P<0.05). CONCLUSION: RIPC can reduce fatty liver I/R injury by affecting the eNOS-NO pathway and liver microRNA expressions.展开更多
文摘AIM： To explore if ischemic preconditioning （IPC） can enhance the survival of retinal ganglion cells （RGCs） after optic nerve axotomy. METHODS： Twenty-four hours prior to retinal ischemia 60min or axotomy, IPC was applied for ten minutes in groups of （n=72） animals. The survival of RGCs, the cellular expression of heat shock protein 27 （HSP27） and heat shock protein 70 （HSP70） and the numbers of retinal microglia in the different groups were quantified at 7 and 14d post-injury. The cellular expression of HSP27 and HSP70 and changes in the numbers of retinal microglia were quantified to detect the possible mechanism of the protection of the IPC. RESULTS： Ten minutes of IPC promoted RGC survival in both the optic nerve injury （IPC-ONT） and the retinal ischemia 60min （IPC-IR60） groups, examined at 7d and 14d post-injury. Microglial proliferation showed little correlation with the extent of benefit effects of IPC on the rescue of RGCs. The number of HSP27-positive RGCs was significantly higher in the IPC-ONT group than in the sham IPC-ONT group, although the percentage of HSP27-positive RGCs did not significantly differ between groups. For the IPC-IR60 group, neither the number nor the percentage ofthe HSP27-positive RGCs differed significantly between the IPC and the sham-operated groups. The number of HSP70-positive RGCs was significantly higher for both the IPC-ONT and the IPC-IR60 experimental groups, but the percentages did not differ. CONCLUSION： The induction of IPC enhances the survival of RGCs against both axotomy and retinal ischemia.
基金The work is financially supported by National Nature Science Foundation of China under Grant number 91130013.
文摘The preconditioned density-based conjugate heat transfer(CHT)algorithm was used to investigate the heat transfer characteristics of a cooled turbine vane.Fluid domain provided boundary heat flux for solid domain and obtained boundary temperature from it for the coupling strategy.The governing equations were solved by the preconditioned density-based finite-volume method,with preconditioning matrix,improved Abu-Gharmam Shaw(AGS)transition model,matrix dissipation scheme and four kinds of turbulence models.The grid system is multi-block structured grids for fluid domain and unstructured grids for solid domain,with full-matched grids at the fluid-solid interfaces.The effects of turbulence model,outlet Mach number,outlet Reynolds number,inlet turbulence intensity and the temperature ratio of blade surface/gas on the local heat transfer performance were studied.Results indicate that the k-o shear-stress transport(SST)and AGS model can predict the conjugate heat transfer better than others.The Mach number and Reynolds number have relatively obvious influences on the heat transfer,while the turbulence intensity and temperature ratio only have slight influences.Comparisons with experimental data demonstrate the applicability and accuracy of the numerical algorithm.
基金supported by a grant from 2013 Applied Basic Research of Changzhou Bureau of Science and Technology(CJ20130044)
文摘BACKGROUND: Ischemic preconditioning (IPC) is a strategy to reduce ischemia-reperfusion (I/R) injury. The protective effect of remote ischemic preconditioning (RIPC) on liver I/R injury is not clear. This study aimed to investigate the roles of RIPC in liver I/R in fatty liver rats and the involvement of endothelial nitric oxide synthase-nitric oxide (eNOS-NO) pathway and microRNA expressions in this process. METHODS: A total of 32 fatty rats were randomly divided into the sham group, I/R group, RIPC group and RIPC+I/R group. Serum alanine aminotransferase (ALT), aspartate aminotransferase (AST) and nitric oxide (NO) were measured. Hematoxylin-eosin staining was used to observe histological changes of liver tissues, TUNEL to detect hepatocyte apoptosis, and immunohistochemistry assay to detect heat shock protein 70 (HSP70) expression. Western blotting was used to detect liver inducible NOS (iNOS) and eNOS protein levels and realtime quantitative polymerase chain reaction to detect miR-34a, miR-122 and miR-27b expressions. RESULTS: Compared with the sham and RIPC groups, serum ALT, AST and iNOS in liver tissue were significantly higher in other two groups, while serum NO and eNOS in liver tissue were lower, and varying degrees of edema, degeneration and inflammatory cell infiltration were found. Cell apoptosis number was slightly lower in the RIPC+I/R group than that in I/R group. Compared with the sham group, HSP70 expressions were significantly increased in other three groups (all P<0.05). Compared with the sham and RIPC groups, elevated miR-34a expressions were found in I/R and RIPC+I/R groups (P<0.05). MiR-122 and miR-27b were found significantly decreased in I/R and RIPC+I/R groups compared with the sham and RIPC groups (all P<0.05). CONCLUSION: RIPC can reduce fatty liver I/R injury by affecting the eNOS-NO pathway and liver microRNA expressions.
