The antigenic variation of influenza A virus hemagglutinin (HA) glycoproteins requires frequent changes in vaccine formulation. The new strategy of creating influenza seed strains for vaccine production is to generate...The antigenic variation of influenza A virus hemagglutinin (HA) glycoproteins requires frequent changes in vaccine formulation. The new strategy of creating influenza seed strains for vaccine production is to generate 7 + 1 reassortants that contain seven genes from a high-yield virus A/Puerto Rico/8/34[A/PR/8/34](H1N1) and the HA gene from the circulating strains. By using this DNA-based cotransfection technique, we generated 7 + 1 reassortants rgH3N1 which had the antigenic determinants of influenza virus A/Songbird/HongKong/102/00[SB/HK/01](H3N8) and 7 other genes from A/PR/ 8/34. The hemagglutinin of A/Songbird/HongKong/102/00 is 96.3% homologous to that of A/Equine/Jilin/98[Eq/Jl/89] (H3N8). The resulting virus rgH3N1 grows to high HA titers in chicken embryonated eggs, allowing vaccine preparation in unconcentrated allantoic fluid. The rgH3N1 is stable after multiple passages in embryonated eggs. The reassortant rgH3N1 virus could be used as vaccine candidate to reduce the reemergence of equine influenza outbreaks.展开更多
Objective:A novel protein was first purified from Panax quinquefolius L.(AGNP),and in vitro antioxidant activities of AGNP were first studied in this work.Methods:AGNP was purified by Ion-exchange chromatography and G...Objective:A novel protein was first purified from Panax quinquefolius L.(AGNP),and in vitro antioxidant activities of AGNP were first studied in this work.Methods:AGNP was purified by Ion-exchange chromatography and Gel-filtration chromatography.The chemical characterizations of AGNP were tested by sodium dodecyl sulfate–polyacrylamide gel electrophoresis(SDS-PAGE),high-pressure gel-filtration chromatography,MALDI-TOF-MS and HPLC.In vitro antioxidant effects were tested in simple antioxidant assay including 2,2-diphenylpicrylhydrazyl radical scavenging,superoxide radical(O2^-)scavenging,hydroxyl radical(OH)scavenging,and ferric-reducing ability.Results:The results showed which the content of AGNP measured by Bradford method was 2.42 mg/m L and the subunit molecular weight of AGNP measured by sodium dodecyl sulfate–polyacrylamide gel electrophoresis(SDS-PAGE)was 15 kD.The AGNP molecular weight was 15,114 Da both of SDS-PAGE and mass spectrum purity.The result of high-pressure gel-filtration chromatography demonstrated that the molecular weight of AGNP was 31,086 Da,which implied that AGNP was a homodimer.The in vitro Antioxidant results indicated that AGNP had obvious effects to remove the free radicals in vitro.Conclusion:In conclusion,AGNP had more powerful antioxidant capacity and it can be used as an effective natural antioxidant to alleviate oxidative stress.展开更多
In recent years, zinc based alloys as a new biodegradable metal material aroused intensive interests. However, the processing of Zn alloys micro-tubes (named slender-diameter and thin-walled tubes) is very difficult...In recent years, zinc based alloys as a new biodegradable metal material aroused intensive interests. However, the processing of Zn alloys micro-tubes (named slender-diameter and thin-walled tubes) is very difficult due to their HCP crystal structure and unfavorable mechanical properties. This study aimed to develop a novel technique to produce micro-tube of Zn alloy with good performance for biodegrad- able vascular stent application. In the present work, a processing method that combined drilling, cold rolling and optimized drawing was proposed to produce the novel Zn-5Mg-1Fe (wt%) alloy micro- tubes. The micro-tube with outer diameter of 2.5 mm and thickness of 130 μm was fabricated by this method and its dimension errors are within 10 μm. The micro-tube exhibits a fine and homogeneous microstructure, and the ultimate tensile strength and ductility are more than 220 MPa and 20% respectively. In addition, the micro-tube and stents of Zn alloy exhibit superior in vitro corrosion and expansion performance. It could be concluded that the novel Zn alloy micro-tube fabricated by above method might be a promising candidate material for biodegradable stent.展开更多
文摘The antigenic variation of influenza A virus hemagglutinin (HA) glycoproteins requires frequent changes in vaccine formulation. The new strategy of creating influenza seed strains for vaccine production is to generate 7 + 1 reassortants that contain seven genes from a high-yield virus A/Puerto Rico/8/34[A/PR/8/34](H1N1) and the HA gene from the circulating strains. By using this DNA-based cotransfection technique, we generated 7 + 1 reassortants rgH3N1 which had the antigenic determinants of influenza virus A/Songbird/HongKong/102/00[SB/HK/01](H3N8) and 7 other genes from A/PR/ 8/34. The hemagglutinin of A/Songbird/HongKong/102/00 is 96.3% homologous to that of A/Equine/Jilin/98[Eq/Jl/89] (H3N8). The resulting virus rgH3N1 grows to high HA titers in chicken embryonated eggs, allowing vaccine preparation in unconcentrated allantoic fluid. The rgH3N1 is stable after multiple passages in embryonated eggs. The reassortant rgH3N1 virus could be used as vaccine candidate to reduce the reemergence of equine influenza outbreaks.
基金financial support from the Jilin Provincial Key Laboratory of Biomacromolecules of Chinese Medicine, Local Standard Project of Chinese Medicinal Materials in Jilin Province (No. PZ-2016-03 and No. JLPZGF-2018-004)The Science and Technology Development Plan Project of Jilin Province (No. 20190101010JH, No. 20190304095YY)+1 种基金The National Key Research and Development Program of China (2017YFC1702106)the National Traditional Chinese Medicine Standardization Project of China (No. ZYBZH-C-JL-22 and No. ZYBZH-C-HEB-11)
文摘Objective:A novel protein was first purified from Panax quinquefolius L.(AGNP),and in vitro antioxidant activities of AGNP were first studied in this work.Methods:AGNP was purified by Ion-exchange chromatography and Gel-filtration chromatography.The chemical characterizations of AGNP were tested by sodium dodecyl sulfate–polyacrylamide gel electrophoresis(SDS-PAGE),high-pressure gel-filtration chromatography,MALDI-TOF-MS and HPLC.In vitro antioxidant effects were tested in simple antioxidant assay including 2,2-diphenylpicrylhydrazyl radical scavenging,superoxide radical(O2^-)scavenging,hydroxyl radical(OH)scavenging,and ferric-reducing ability.Results:The results showed which the content of AGNP measured by Bradford method was 2.42 mg/m L and the subunit molecular weight of AGNP measured by sodium dodecyl sulfate–polyacrylamide gel electrophoresis(SDS-PAGE)was 15 kD.The AGNP molecular weight was 15,114 Da both of SDS-PAGE and mass spectrum purity.The result of high-pressure gel-filtration chromatography demonstrated that the molecular weight of AGNP was 31,086 Da,which implied that AGNP was a homodimer.The in vitro Antioxidant results indicated that AGNP had obvious effects to remove the free radicals in vitro.Conclusion:In conclusion,AGNP had more powerful antioxidant capacity and it can be used as an effective natural antioxidant to alleviate oxidative stress.
基金supported by the National Basic Research Program of China(973 Program)(Grant No.2012CB619102)the National Science Foundation of China(Grant No.31400821)the innovation fund of Western Metal Materials(Grant No.XBCL-3-14)
文摘In recent years, zinc based alloys as a new biodegradable metal material aroused intensive interests. However, the processing of Zn alloys micro-tubes (named slender-diameter and thin-walled tubes) is very difficult due to their HCP crystal structure and unfavorable mechanical properties. This study aimed to develop a novel technique to produce micro-tube of Zn alloy with good performance for biodegrad- able vascular stent application. In the present work, a processing method that combined drilling, cold rolling and optimized drawing was proposed to produce the novel Zn-5Mg-1Fe (wt%) alloy micro- tubes. The micro-tube with outer diameter of 2.5 mm and thickness of 130 μm was fabricated by this method and its dimension errors are within 10 μm. The micro-tube exhibits a fine and homogeneous microstructure, and the ultimate tensile strength and ductility are more than 220 MPa and 20% respectively. In addition, the micro-tube and stents of Zn alloy exhibit superior in vitro corrosion and expansion performance. It could be concluded that the novel Zn alloy micro-tube fabricated by above method might be a promising candidate material for biodegradable stent.