A new high strength 2A97 Al-Cu-Li-X alloy was subjected to triple-aging of retrogression and re-aging treatments （RRA）. Transmission electron microscopy （TEM）, differential scanning calorimetry （DSC）, and tensil...A new high strength 2A97 Al-Cu-Li-X alloy was subjected to triple-aging of retrogression and re-aging treatments （RRA）. Transmission electron microscopy （TEM）, differential scanning calorimetry （DSC）, and tensile tests were used to investigate the effects of RRA treatment on the microstructures and properties. DSC test reveals the reversion temperature range of the strengthening δ＇ （Al3Li） phase. The results show that the microstructure consists of δ＇ （Al3Li） phase, T1 （Al2CuLi） phase and θ″/θ′（Al2Cu） phase for 2A97 alloy treated by a triple-aging of a retrogression and re-aging treatment in the following order： （1） at 165℃×30 min, （2） at 220 ℃ or 240℃ × 15 min, （3） at 165℃×24 h. The plastic deformation, incorporated into the treatment after secondary high temperature aging, promotes the T1 precipitation during final re-aging. The tensile properties of the alloy treated by the retrogression and re-aging treatment reach the peak level of alloy single-aged at 165℃ in T6 temper.展开更多
Background The Fc receptor associated pathway might improve the immune responses against hepatitis B virus （HBV） as previously described by us. In addition, the Fit3 ligand （FL） has been reported to potentiate ant...Background The Fc receptor associated pathway might improve the immune responses against hepatitis B virus （HBV） as previously described by us. In addition, the Fit3 ligand （FL） has been reported to potentiate antigen presenting cells in vivo and may act as a potential adjuvant to boost antigen-specific immune responses. In this study, the immune efficacies of a set of fusion proteins of HBsAg and Fc and/or FL were evaluated in HBsAg transgenic mice. Methods The fusion proteins composed of HBsAg and the Fc domain of murine IgG1 （HBsAg-Fc） and/or the Fit3 ligand, and yeast-derived recombinant HBsAg were used as immunogen to immunize HBsAg transgenic mice, respectively. Serum and liver HBsAg levels, serum anti-HBsAg and cytokine profile, and the activities of alanine aminotransferase （ALT）/AST were investigated after immunization. Results After six injections, the most pronounced decrease in serum and liver HBsAg levels was observed in the HBsAg-Fc immunized group. In addition, serum Thl cytokines and ALT/AST activities were highest in this group, indicating an effective induction of a favorable cellular immune response. Interestingly, the fusion protein containing HBsAg-Fc and the Fit3 ligand stimulated an alternative Thl-type immune response featured with high level productions of tumor necrosis factor a （TNF-a） and monocyte chemoabstractant protein 1 （MCP-1）, causing a more severe cytotoxicity in hepatocytes while showed less effective in reducing serum HBsAg level. Conclusion HBsAg-Fc is effective in eliciting both the humeral and cellular immune responses against HBsAg in HBsAg transgenic mice, which makes it a potential immunogen for the immunotherapy of chronic hepatitis B.展开更多
基金"973" Key Project of Chinese National Programs for Fundamental Research and Development (2005CB623705)
文摘A new high strength 2A97 Al-Cu-Li-X alloy was subjected to triple-aging of retrogression and re-aging treatments （RRA）. Transmission electron microscopy （TEM）, differential scanning calorimetry （DSC）, and tensile tests were used to investigate the effects of RRA treatment on the microstructures and properties. DSC test reveals the reversion temperature range of the strengthening δ＇ （Al3Li） phase. The results show that the microstructure consists of δ＇ （Al3Li） phase, T1 （Al2CuLi） phase and θ″/θ′（Al2Cu） phase for 2A97 alloy treated by a triple-aging of a retrogression and re-aging treatment in the following order： （1） at 165℃×30 min, （2） at 220 ℃ or 240℃ × 15 min, （3） at 165℃×24 h. The plastic deformation, incorporated into the treatment after secondary high temperature aging, promotes the T1 precipitation during final re-aging. The tensile properties of the alloy treated by the retrogression and re-aging treatment reach the peak level of alloy single-aged at 165℃ in T6 temper.
文摘Background The Fc receptor associated pathway might improve the immune responses against hepatitis B virus （HBV） as previously described by us. In addition, the Fit3 ligand （FL） has been reported to potentiate antigen presenting cells in vivo and may act as a potential adjuvant to boost antigen-specific immune responses. In this study, the immune efficacies of a set of fusion proteins of HBsAg and Fc and/or FL were evaluated in HBsAg transgenic mice. Methods The fusion proteins composed of HBsAg and the Fc domain of murine IgG1 （HBsAg-Fc） and/or the Fit3 ligand, and yeast-derived recombinant HBsAg were used as immunogen to immunize HBsAg transgenic mice, respectively. Serum and liver HBsAg levels, serum anti-HBsAg and cytokine profile, and the activities of alanine aminotransferase （ALT）/AST were investigated after immunization. Results After six injections, the most pronounced decrease in serum and liver HBsAg levels was observed in the HBsAg-Fc immunized group. In addition, serum Thl cytokines and ALT/AST activities were highest in this group, indicating an effective induction of a favorable cellular immune response. Interestingly, the fusion protein containing HBsAg-Fc and the Fit3 ligand stimulated an alternative Thl-type immune response featured with high level productions of tumor necrosis factor a （TNF-a） and monocyte chemoabstractant protein 1 （MCP-1）, causing a more severe cytotoxicity in hepatocytes while showed less effective in reducing serum HBsAg level. Conclusion HBsAg-Fc is effective in eliciting both the humeral and cellular immune responses against HBsAg in HBsAg transgenic mice, which makes it a potential immunogen for the immunotherapy of chronic hepatitis B.
