Fabrication and Electrochemical Characterization of Sulfurized-Polyacrylonitrile Nanofiber Electrodes for Na/S Batteries Using Various Polyacrylonitrile Solutions.

A polyacrylonitrile (PAN) nanofiber web was prepared by electrospinning PAN solutions with dimethyl sulfoxide (DMSO) or Dimethylformamide (DMF) as solvent. The PAN web was heated with sulfur to synthesize a sulfurized polyacrylonitrile (SPAN) nanofiber web. The shape of the SPAN web was found to depend on concentration of the PAN solution and properties of the solvent. The SPAN web synthesized using 8 wt% PAN solution in DMSO showed the highest capacity of 1053.3 mAh g-1sulfur under a current density of 526 mA g-1sulfur. Thus, we determined that DMSO could be a potential solvent for preparation of SPAN web electrodes.

Viability of the antigen determines whether DNA or urocanic acid act as initiator molecules for UV-induced suppression of delayed-type hypersensitivity.

UV radiation suppresses the immune response, and UV-induced immune suppression contributes to UV-induced photocarcinogenesis. For UV-induced immune suppression to occur, electromagnetic energy (i.e. UV radiation) must be converted to a biological signal. Two photoreceptors have been identified in the skin that serves this purpose, epidermal DNA and trans-urocanic acid (UCA). Although compelling evidence exists to support a role for each pathway (UV-induced DNA damage or photoisomerization of UCA) in UV-induced immune suppression, it is not clear what determines which photoreceptor pathway is activated. To address this question, we injected UV-irradiated mice with a monoclonal antibody with specificity for cis-UCA or applied liposomes containing DNA repair enzymes to the skin of UV-irradiated mice. The effect that each had on UV-induced suppression of delayed-type hypersensitivity was measured. We asked whether the light source used (FS-40 sunlamps vs solar-simulated UV radiation) altered whichever pathway of immune suppression was activated. Different doses of UV radiation and the viability of the antigen were also considered. Neither the dose of UV nor the light source had any influence on determining which pathway was activated. Rather, we found that the viability of the antigen was the critical determinant. When live antigens were used, UV-induced immune suppression was blocked with monoclonal anti-cis-UCA but not with T4 endonuclease V-containing liposomes. The reverse was observed when formalin-fixed or killed antigens were used. Our findings indicate that antigen viability dictates which photoreceptor pathway predominates after UV exposure.