The creation of anodic ethanol oxidation reaction catalysts with superior all-around performance for direct ethanol fuel cells(DEFCs)has continued to attract the attention of researchers.An ultrathin trimetallic PtAuB...The creation of anodic ethanol oxidation reaction catalysts with superior all-around performance for direct ethanol fuel cells(DEFCs)has continued to attract the attention of researchers.An ultrathin trimetallic PtAuBi aerogel with branching,rough-surfaced 1D nanowires that self-assemble into a 3D porous network structure has been created in this study.It has a mass activity(MA)of 8045 mA mgPt^(-1)in an alkaline medium,which is 7.56 times greater than that of commercial Pt/C(1064 mA mgPt^(-1)).Notably,the catalytic activity and resistance to CO poisoning of PtAuBi aerogels are improved by the addition of an efficient"active additive"Au.The results analysis reveals that the increased performance of PtAuBi aerogel is mostly attributable to the integrated function of the 3D porous network structure,the downward shift of the Pt d-band center,and the synergistic effect of the"Pt-Bi"and/or"Pt-Au"dual active sites.展开更多
Cancer occurrence and development has been demonstrated to be associated with escape from immune surveillance, and low eostimulatory molecules expression has been considered as one of the important reasons for cancer ...Cancer occurrence and development has been demonstrated to be associated with escape from immune surveillance, and low eostimulatory molecules expression has been considered as one of the important reasons for cancer evading the immune system. 4-1BB （CD137） is a costimulatory molecule expressed on the surface of activated T cells. Interaction of 4-1BB with its natural ligand （4-1BBL） expressed on antigen presenting cells （APCs） has been shown to amplify T-cell mediated immunity. We therefore examined whether murine cancer cells expressing 4-1BBL could produce antitumor effects in inoculated mice. Mouse forestomach carcinoma （MFC） cells were transfected with 4-1BBL gene （MFC/4-1BBL）. The proliferation of the transduced cells in vitro was not different from that of parental cells. However, MFC/4-1BBL cells developed small tumors and induced higher cytotoxicity of tumor infiltration lymphocyte （TIL）. Production of cytokines （IFN-γ TNF-α and IL-2） in serum and cytotoxic T lymphocyte （CTL） activity of splenocytes from mice immunized with mitomycin C （MMC）-treated MFC/4-1BBL cells were significantly higher than that from mice immunized with MMC-treated parental MFC and MFC/ pMKITneo cells. These results suggest that modification of cancer cells with 4-1BBL gene can produce antitumor immune responses.展开更多
Interleukin （IL）-23, a cytokine composed of p19 and the p40 subunit of IL-12, can enhance the proliferation of memory T cells and production of IFN-γ from activated T cells. It can also induce antitumor effects in ...Interleukin （IL）-23, a cytokine composed of p19 and the p40 subunit of IL-12, can enhance the proliferation of memory T cells and production of IFN-γ from activated T cells. It can also induce antitumor effects in murine model. To further evaluate the antitumor activity and immune enhancement of IL-23 in vivo, murine colon carcinoma cells retrovirally transduced with mIL-23 gene were injected subcutaneously （s.c.） into BALB/c mice. Survival time and tumor volume were observed. LDH release assay, [^3H]-TdR incorporation assay and ELISA were used to determine CTL activity, proliferation of splenocytes and level of cytokines, respectively. Number of dendritic cells （DCs） was analyzed by flow cytometry （FCM）. IL-23 secreted by Colon26/IL-23 cells suppressed the growth of tumor and prolonged the survival time of mice, enhanced proliferation of splenocytes, CTL activity, and number of DCs. IL-23 also promoted the production of Thl cytokines such as IFN-γ, IL-12 and TNF-α. However, the level of IL-4 was not enhanced significantly. These data suggested that IL-23 secreted by tumor cells can induce antitumor activitv bv enhancing immune resnonse.展开更多
The evolution of corrosion behavior of 316 L stainless steels exposed to salt lake atmosphere for 8 years was investigated.The results showed that the stainless steel in salt lake atmosphere had a greater corrosion ra...The evolution of corrosion behavior of 316 L stainless steels exposed to salt lake atmosphere for 8 years was investigated.The results showed that the stainless steel in salt lake atmosphere had a greater corrosion rate during the initial exposure time and relatively lower corrosion rate during the subsequent exposure time.Dust depositions accumulated on the downward surface caused severe local corrosion of stainless steel.As exposure time prolonged,the relative amount of Croxide and Feoxidein the corrosion products gradually increased,which may directly affect the corrosion rate of stainless steels.Moreover,the maximum pit depth followed a power function with respect to exposure time.展开更多
基金supported by the National Natural Science Foundation of China(91745112)the Science and Technology Commission of Shanghai Municipality(22010501200,21ZR1425000,19DZ2271100).
文摘The creation of anodic ethanol oxidation reaction catalysts with superior all-around performance for direct ethanol fuel cells(DEFCs)has continued to attract the attention of researchers.An ultrathin trimetallic PtAuBi aerogel with branching,rough-surfaced 1D nanowires that self-assemble into a 3D porous network structure has been created in this study.It has a mass activity(MA)of 8045 mA mgPt^(-1)in an alkaline medium,which is 7.56 times greater than that of commercial Pt/C(1064 mA mgPt^(-1)).Notably,the catalytic activity and resistance to CO poisoning of PtAuBi aerogels are improved by the addition of an efficient"active additive"Au.The results analysis reveals that the increased performance of PtAuBi aerogel is mostly attributable to the integrated function of the 3D porous network structure,the downward shift of the Pt d-band center,and the synergistic effect of the"Pt-Bi"and/or"Pt-Au"dual active sites.
基金a grant from Hebei Provincial Department of Educationa grant from Hebei Provincial Department of Science and Technology (06276102D-95)
文摘Cancer occurrence and development has been demonstrated to be associated with escape from immune surveillance, and low eostimulatory molecules expression has been considered as one of the important reasons for cancer evading the immune system. 4-1BB （CD137） is a costimulatory molecule expressed on the surface of activated T cells. Interaction of 4-1BB with its natural ligand （4-1BBL） expressed on antigen presenting cells （APCs） has been shown to amplify T-cell mediated immunity. We therefore examined whether murine cancer cells expressing 4-1BBL could produce antitumor effects in inoculated mice. Mouse forestomach carcinoma （MFC） cells were transfected with 4-1BBL gene （MFC/4-1BBL）. The proliferation of the transduced cells in vitro was not different from that of parental cells. However, MFC/4-1BBL cells developed small tumors and induced higher cytotoxicity of tumor infiltration lymphocyte （TIL）. Production of cytokines （IFN-γ TNF-α and IL-2） in serum and cytotoxic T lymphocyte （CTL） activity of splenocytes from mice immunized with mitomycin C （MMC）-treated MFC/4-1BBL cells were significantly higher than that from mice immunized with MMC-treated parental MFC and MFC/ pMKITneo cells. These results suggest that modification of cancer cells with 4-1BBL gene can produce antitumor immune responses.
文摘Interleukin （IL）-23, a cytokine composed of p19 and the p40 subunit of IL-12, can enhance the proliferation of memory T cells and production of IFN-γ from activated T cells. It can also induce antitumor effects in murine model. To further evaluate the antitumor activity and immune enhancement of IL-23 in vivo, murine colon carcinoma cells retrovirally transduced with mIL-23 gene were injected subcutaneously （s.c.） into BALB/c mice. Survival time and tumor volume were observed. LDH release assay, [^3H]-TdR incorporation assay and ELISA were used to determine CTL activity, proliferation of splenocytes and level of cytokines, respectively. Number of dendritic cells （DCs） was analyzed by flow cytometry （FCM）. IL-23 secreted by Colon26/IL-23 cells suppressed the growth of tumor and prolonged the survival time of mice, enhanced proliferation of splenocytes, CTL activity, and number of DCs. IL-23 also promoted the production of Thl cytokines such as IFN-γ, IL-12 and TNF-α. However, the level of IL-4 was not enhanced significantly. These data suggested that IL-23 secreted by tumor cells can induce antitumor activitv bv enhancing immune resnonse.
基金supported by the National Natural Science Foundation of China(Nos.51601199 and 51671197)。
文摘The evolution of corrosion behavior of 316 L stainless steels exposed to salt lake atmosphere for 8 years was investigated.The results showed that the stainless steel in salt lake atmosphere had a greater corrosion rate during the initial exposure time and relatively lower corrosion rate during the subsequent exposure time.Dust depositions accumulated on the downward surface caused severe local corrosion of stainless steel.As exposure time prolonged,the relative amount of Croxide and Feoxidein the corrosion products gradually increased,which may directly affect the corrosion rate of stainless steels.Moreover,the maximum pit depth followed a power function with respect to exposure time.
