The convective heat transfer of supercritical-pressure RP-3(Rocket Propellant 3)aviation kerosene in a horizontal circular tube has been numerically studied,focusing mainly on the non-uniform heat transfer deteriorati...The convective heat transfer of supercritical-pressure RP-3(Rocket Propellant 3)aviation kerosene in a horizontal circular tube has been numerically studied,focusing mainly on the non-uniform heat transfer deterioration along the circumferential direction.The governing equations of mass,momentum and energy have been solved using the pressure-based segregated solver based on the finite volume method.The re-normalization group(RNG)k-εturbulence model with an enhanced wall treatment was selected.Considering the heat conduction in the solid wall,the mechanism of heat transfer deterioration and the buoyancy effect on deteriorated heat transfer were discussed.The evolution of secondary flow was analyzed.Effects of the outer-wall heat flux,mass flux,pressure and tube thermal conductivity on heat transfer were investigated.Moreover,the buoyancy criterion and the heat transfer correlation were obtained.Results indicate that the poor flow performance of near-wall fluid causes the pseudo-film boiling,further leads to the heat transfer deterioration.The strong buoyancy has an effect of enhancing the heat transfer at the bottom of tube,and weakening the heat transfer at the top of tube,which results in the non-uniform inner-wall temperature and heat flux distributions.Decreasing the ratio of outer-wall heat flux and mass flux,increasing the pressure could weaken the heat transfer difference along the circumferential direction,while the effect of thermal conductivity of tube on the circumferential parameters distributions is more complicated.When the buoyancy criterion of(Grq/Grth)max≤0.8 is satisfied,the effect of buoyancy could be ignored.The new correlations work well for non-uniform heat transfer predictions.展开更多
Ischemic stroke(IS)represents a significant threat to brain health due to its elevated mortality and disability rates.The efficacy of small-molecule neuroprotective agents has been impeded by challenges associated wit...Ischemic stroke(IS)represents a significant threat to brain health due to its elevated mortality and disability rates.The efficacy of small-molecule neuroprotective agents has been impeded by challenges associated with traversing the blood-brain barrier(BBB)and limited bioavailability.Conversely,advanced nano drug delivery systems hold promise for overcoming these obstacles by facilitating efficient transportation across the BBB and maintaining optimal drug concentrations.This review aims to explore advanced neuroprotective nano drug delivery systems as a means of effectively administering neuroprotective agents to the brain using pharmaceutical approaches in the treatment of IS.By examining these systems,researchers and clinicians can gain valuable insights and innovative concepts,illuminating the potential of advanced neuroprotective nano drug delivery systems.Leveraging these advancements can drive the progress of pioneering and efficacious therapeutic interventions for IS.展开更多
Although some co-risk factors and hemodynamic alterations are involved in hypertension progression,their direct biomechanical effects are unclear.Here,we constructed a high-hydrostatic-pressure cell-culture system to ...Although some co-risk factors and hemodynamic alterations are involved in hypertension progression,their direct biomechanical effects are unclear.Here,we constructed a high-hydrostatic-pressure cell-culture system to imitate constant hypertension and identified novel molecular classifications of human aortic smooth muscle cells(HASMCs)by single-cell transcriptome analysis.Under 100-mmHg(analogous to healthy human blood pressure)or 200-mmHg(analogous to hypertension)hydrostatic pressure for 48 h,HASMCs showed six distinct vascular SMC(VSMC)clusters according to differential gene expression and gene ontology enrichment analysis.Especially,two novel HASMC subsets were identified,named the inflammatory subset,with CXCL2,CXCL3 and CCL2 as markers,and the endothelial-function inhibitory subset,with AKR1C2,AKR1C3,SERPINF1 as markers.The inflammatory subset promoted CXCL2&3 and CCL2 chemokine expression and secretion,triggering monocyte migration;the endothelial-function inhibitory subset secreted SERPINF1 and accelerated prostaglandin F2αgeneration to inhibit angiogenesis.The expression of the two VSMC subsets was greatly increased in arterial media from patients with hypertension and experimental animal models of hypertension.Collectively,we identified high hydrostatic pressure directly driving VSMCs into two new subsets,promoting or exacerbating endothelial dysfunction,thereby contributing to the pathogenesis of cardiovascular diseases.展开更多
基金support from the National Natural Science Foundation of China(No.51576027)。
文摘The convective heat transfer of supercritical-pressure RP-3(Rocket Propellant 3)aviation kerosene in a horizontal circular tube has been numerically studied,focusing mainly on the non-uniform heat transfer deterioration along the circumferential direction.The governing equations of mass,momentum and energy have been solved using the pressure-based segregated solver based on the finite volume method.The re-normalization group(RNG)k-εturbulence model with an enhanced wall treatment was selected.Considering the heat conduction in the solid wall,the mechanism of heat transfer deterioration and the buoyancy effect on deteriorated heat transfer were discussed.The evolution of secondary flow was analyzed.Effects of the outer-wall heat flux,mass flux,pressure and tube thermal conductivity on heat transfer were investigated.Moreover,the buoyancy criterion and the heat transfer correlation were obtained.Results indicate that the poor flow performance of near-wall fluid causes the pseudo-film boiling,further leads to the heat transfer deterioration.The strong buoyancy has an effect of enhancing the heat transfer at the bottom of tube,and weakening the heat transfer at the top of tube,which results in the non-uniform inner-wall temperature and heat flux distributions.Decreasing the ratio of outer-wall heat flux and mass flux,increasing the pressure could weaken the heat transfer difference along the circumferential direction,while the effect of thermal conductivity of tube on the circumferential parameters distributions is more complicated.When the buoyancy criterion of(Grq/Grth)max≤0.8 is satisfied,the effect of buoyancy could be ignored.The new correlations work well for non-uniform heat transfer predictions.
基金financial support provided by the National Natural Science Foundation of Shanghai(No.20ZR1420000)Shanghai Shen Kang Center Research Physician Training Program on Innovation and Translation Capabilities(No.SHDC2022CRS051)Three-Year Action Plan for Improving Clinical Research Capacity of International Peace Maternal and Child Health Hospital,Shanghai Jiao Tong University School of Medicine(No.IPMCH2022CR1-05).
文摘Ischemic stroke(IS)represents a significant threat to brain health due to its elevated mortality and disability rates.The efficacy of small-molecule neuroprotective agents has been impeded by challenges associated with traversing the blood-brain barrier(BBB)and limited bioavailability.Conversely,advanced nano drug delivery systems hold promise for overcoming these obstacles by facilitating efficient transportation across the BBB and maintaining optimal drug concentrations.This review aims to explore advanced neuroprotective nano drug delivery systems as a means of effectively administering neuroprotective agents to the brain using pharmaceutical approaches in the treatment of IS.By examining these systems,researchers and clinicians can gain valuable insights and innovative concepts,illuminating the potential of advanced neuroprotective nano drug delivery systems.Leveraging these advancements can drive the progress of pioneering and efficacious therapeutic interventions for IS.
基金supported by the National Key Research and Development Program of China(2018YFC1312703)CAMS Innovation Fund for Medical Sciences(CIFMS,2016-12M1–006)+1 种基金the National Natural Science Foundation of China(81630014,81825002,81800367,81870318,81670379)Beijing Outstanding Young Scientist Program(BJJWZYJH01201910023029).
文摘Although some co-risk factors and hemodynamic alterations are involved in hypertension progression,their direct biomechanical effects are unclear.Here,we constructed a high-hydrostatic-pressure cell-culture system to imitate constant hypertension and identified novel molecular classifications of human aortic smooth muscle cells(HASMCs)by single-cell transcriptome analysis.Under 100-mmHg(analogous to healthy human blood pressure)or 200-mmHg(analogous to hypertension)hydrostatic pressure for 48 h,HASMCs showed six distinct vascular SMC(VSMC)clusters according to differential gene expression and gene ontology enrichment analysis.Especially,two novel HASMC subsets were identified,named the inflammatory subset,with CXCL2,CXCL3 and CCL2 as markers,and the endothelial-function inhibitory subset,with AKR1C2,AKR1C3,SERPINF1 as markers.The inflammatory subset promoted CXCL2&3 and CCL2 chemokine expression and secretion,triggering monocyte migration;the endothelial-function inhibitory subset secreted SERPINF1 and accelerated prostaglandin F2αgeneration to inhibit angiogenesis.The expression of the two VSMC subsets was greatly increased in arterial media from patients with hypertension and experimental animal models of hypertension.Collectively,we identified high hydrostatic pressure directly driving VSMCs into two new subsets,promoting or exacerbating endothelial dysfunction,thereby contributing to the pathogenesis of cardiovascular diseases.
