Weight penalty has been a challenge for design engineers of aerospace vehicles.Today’s high-efficiency combat aircraft undergoes intense stress and strain during flying missions,which require stronger and stiffer mat...Weight penalty has been a challenge for design engineers of aerospace vehicles.Today’s high-efficiency combat aircraft undergoes intense stress and strain during flying missions,which require stronger and stiffer materials to retain structural integrity.Though metallic materials have been successfully used for the construction of aircraft structures and components,metals still have a low strength-to-weight ratio.This paper aims to develop an alternate optimised material selection methodology to replace the metallic skin of a medium-sized military aircraft.The search for the optimum material will result in reduced aircraft weight which will be benefitted by extra payload on the aircraft.The selection methodology is comprised of finding design pressure limits on the aircraft skin,and comparison of properties(strength,elastic modulus,shear modulus,etc.)and performance(safety factor,deflection,and stress)of the existing metallic skin with alternate optimised material.The comparison was made under aerodynamic pressure,bending force,and twisting moment.Carbon Fibre Reinforced Polymer/Epoxy(CFRP)Uni-Directional(UD)prepreg(elastic modolus is 209 GPa)was selected as an alternate optimum material to replace the aluminium alloy skin of the aircraft studied.The selected alternate optimum material resulted in the reduction of aircraft skin weight by 30%.展开更多
To function optimally,human blood natural killer(NK)cells need to communicate with other immune cells.Previously,it has been shown that NK cells communicate with 6-sulfo LacNAc dendritic cells(slanDCs),which are able ...To function optimally,human blood natural killer(NK)cells need to communicate with other immune cells.Previously,it has been shown that NK cells communicate with 6-sulfo LacNAc dendritic cells(slanDCs),which are able to stimulate NK cells in vitro.In this study,we investigated how slanDCs regulate the level of NK cell activation.The secretion of interleukin(IL)-1βby slanDCs during coculture with NK cells increased as a result of signaling via intercellular adhesion molecule-1 on slanDCs following its interaction with lymphocyte functionassociated antigen-1 on NK cells.IL-1βinduced the expression of Fas receptor(CD95)on NK cells.The binding of Fas ligand(CD178)to CD95 induced the apoptosis of activated NK cells.Moreover,IL-1βalso induced increased cyclooxygenase-2 expression in slanDCs,which in turn enabled the cells to secrete prostaglandin(PG)-E2.Consequently,PGE2 acted as a suppressing agent,tuning down the activation level of NK cells.In summary,IL-1βlimits the level of NK cell activation by inducing apoptosis and suppression as a homeostatic regulatory function.展开更多
基金funding this work through the Large Groups Research Project(No.RGP.2/163/43).
文摘Weight penalty has been a challenge for design engineers of aerospace vehicles.Today’s high-efficiency combat aircraft undergoes intense stress and strain during flying missions,which require stronger and stiffer materials to retain structural integrity.Though metallic materials have been successfully used for the construction of aircraft structures and components,metals still have a low strength-to-weight ratio.This paper aims to develop an alternate optimised material selection methodology to replace the metallic skin of a medium-sized military aircraft.The search for the optimum material will result in reduced aircraft weight which will be benefitted by extra payload on the aircraft.The selection methodology is comprised of finding design pressure limits on the aircraft skin,and comparison of properties(strength,elastic modulus,shear modulus,etc.)and performance(safety factor,deflection,and stress)of the existing metallic skin with alternate optimised material.The comparison was made under aerodynamic pressure,bending force,and twisting moment.Carbon Fibre Reinforced Polymer/Epoxy(CFRP)Uni-Directional(UD)prepreg(elastic modolus is 209 GPa)was selected as an alternate optimum material to replace the aluminium alloy skin of the aircraft studied.The selected alternate optimum material resulted in the reduction of aircraft skin weight by 30%.
基金grants from the Deutsche Forschungsgemeinschaft(DFG):SFB738/A5,Deutsche Zentrum für Infektionsforschung(DZIF):TTU 04.802,Hannover Biomedical Research School(HBRS),REBIRTH Cluster of Excellence and Niedersächsische Krebsgesellschaft e.V.
文摘To function optimally,human blood natural killer(NK)cells need to communicate with other immune cells.Previously,it has been shown that NK cells communicate with 6-sulfo LacNAc dendritic cells(slanDCs),which are able to stimulate NK cells in vitro.In this study,we investigated how slanDCs regulate the level of NK cell activation.The secretion of interleukin(IL)-1βby slanDCs during coculture with NK cells increased as a result of signaling via intercellular adhesion molecule-1 on slanDCs following its interaction with lymphocyte functionassociated antigen-1 on NK cells.IL-1βinduced the expression of Fas receptor(CD95)on NK cells.The binding of Fas ligand(CD178)to CD95 induced the apoptosis of activated NK cells.Moreover,IL-1βalso induced increased cyclooxygenase-2 expression in slanDCs,which in turn enabled the cells to secrete prostaglandin(PG)-E2.Consequently,PGE2 acted as a suppressing agent,tuning down the activation level of NK cells.In summary,IL-1βlimits the level of NK cell activation by inducing apoptosis and suppression as a homeostatic regulatory function.
