Selective Function of PKC-θin T cells

T cell activation is a critical process in initiating adaptive immune response since only through this process the naive antigen specific T cells differentiate into armed effector T cells that mediate the actual immune response. During T cell activation, naive T cells undergo clonal expansion and acquire the capability to kill target cells infected with pathogens or produce cytokines essential for regulating immune response. Inappropriate activation or inactivation of T cells leads to autoimmunity or severe immunodeficiencies. PKC-θ is selectively expressed in T cells and required for mediating T cell activation process. Mice deficient in PKC-θ exhibit defects in T cell activation, survival and activation-induced cell death. PKC-θ selectively translocates to immunological synapse and mediates the signals required for activation of NF-κB, AP1 and NFAT that are essential for T cell activation. Furthermore, PKC-θ^-│- mice displayed multiple defects in the development of T cell-mediated immune responses in vivo. PKC-θ is thus a critical molecule that regulates T cell function at multiple stages in T cell-mediated immune responses in vivo.

Down-conversion materials for organic solar cells:Progress,challenges,and perspectives

Organic solar cells(OSCs)in terms of power conversion efficiency(PCE)and operational lifetime have made remarkable progress during the last decade by improving the active layer materials and introducing new interlayers.The newly developed wide bandgap organic donor and low bandgap acceptor molecules covered the absorption from the visible to the near-infrared region.Whereas the incident high energy region(UV)is not in favor of OSCs.Its absorption causes thermalization losses and photoinduced degradation,which hinders the PCE and lifetime of OSCs.Recently,lanthanide and non-lanthanide-based down-conversion(DC)materials have been introduced,which can effectively convert the high-energy photons(UV)to low-energy photons(visible)and resolve the spectral mismatch losses that limit the absorption of OSCs in high energy incident spectrum.Furthermore,the DC materials also protect the OSCs from UV-induced degradation.The DC materials were also proposed to cross the Shockley-Queisser efficiency limit of the solar cell.In this review,the need for DC materials and their processing method for OSCs have been thoroughly discussed.However,the main emphasis has been given to developing lanthanides and non-lanthanides-based DC materials for OSCs,their applications,and their impact on photovoltaic device performance,stability,and future perspectives.