This article mainly discussed bulk material lHvl^ared by powder metallurgy, and the commercial 2024 aluminum alloy powder and FeNiCrCoA13 high entropy alloy powder （both produced by argon gas atomization process） we...This article mainly discussed bulk material lHvl^ared by powder metallurgy, and the commercial 2024 aluminum alloy powder and FeNiCrCoA13 high entropy alloy powder （both produced by argon gas atomization process） were ball-milled for different hours. The prepared powder was consolidated by hot extrusion method. The microstruetures of the milled powder and bulk alloy were examined by X - Ray Diffraction （XRD）, Scanning Electron Microscopy （SEM） and Transmission Electron Microscopy （TEM）. The thermal stability was tested by differential scanning calorimetry （DSC）. Mechanical properties of the extruded alloy were examined by Vickers hardness tester and mechanical testing machine. The results show that after milling, the mixed particle sizes and microstructures of the alloy powder change obviously. The compressive strength of the extruded alloy has reached 580 MPa under certain conditions of milling time and composition.展开更多
目的分析相关疫苗上市后中国大陆肠道病毒71型(enterovirus type 71,EV71)C4亚型的分子流行特征。方法基于贝叶斯的马尔可夫链蒙特卡罗(markov chain monte carlo,MCMC)分析方法,对EV71疫苗上市前后中国大陆EV71毒株VP1基因相似性进行...目的分析相关疫苗上市后中国大陆肠道病毒71型(enterovirus type 71,EV71)C4亚型的分子流行特征。方法基于贝叶斯的马尔可夫链蒙特卡罗(markov chain monte carlo,MCMC)分析方法,对EV71疫苗上市前后中国大陆EV71毒株VP1基因相似性进行比较。应用贝叶斯天际线模型和SpreaD3 v0.9.6软件对中国大陆C4亚型病毒进行系统发生地理学分析,通过绘制贝叶斯天际线图描绘种群动态历史变化,并应用EasyCodeML软件分析正选择压力位点。结果中国大陆EV71 C4亚型VP1基因序列的平均进化速率为2.25×10-3 site/year,C4a亚型毒株平均进化速率为3.1×10-3 site/year;EV71 C4亚型的起源可追溯至1990年的华东地区,C4a亚型可能起源于1999年。2002—2007年C4亚型经历了种群规模扩张,种群规模于2007年达峰值,且在EV71疫苗上市后仍保持较高水平。C4亚型病毒VP1基因中有5个氨基酸位点承受正选择压力,比对分析EV71疫苗上市后2015—2018年C4亚型病毒序列,筛选到VP1基因第289位点承受正选择压力。结论本研究揭示了EV71 C4亚型的遗传进化信息,为制定手足口病(hand,foot and mouth disease,HFMD)的防控策略提供了科学的数据支持。展开更多
2024 Aluminum alloy powder( 60wt%) and Fe-based amorphous powder( 40 wt%) were adopted. They were mechanical machined for 48hours after being mixed. Bulk material was gained after Spark Plasma Sintering. The sintering...2024 Aluminum alloy powder( 60wt%) and Fe-based amorphous powder( 40 wt%) were adopted. They were mechanical machined for 48hours after being mixed. Bulk material was gained after Spark Plasma Sintering. The sintering parameters included sintering temperature,heating or cooling rates,pressure and holding time. 300 ℃- 800 ℃ were adopted while the heating or cooling rate was 100 ℃ / min and with the pressure of 50 MPa in the experiments. The holding time was 10 min or 20 min at different temperatures, respectively. Bulk materials after sintering were examined by Scanning Electron Microscopy and X-Ray Diffraction. The micro-hardness and relative density also were tested. The sintering temperature had the most significant influence on the microstructure and property of the bulk material. The influence of holding time came second while the heating or cooling rates and pressure were fixed. The density became larger with the increase of the temperature. The compactness was best at 500℃. The pressure and generation of high-temperature phases were the factors which affected the density and the compactness.展开更多
目的建立第一代国家柯萨奇病毒A组16型(CV-A16)抗原标准品,用于CV-A16疫苗的抗原含量检测.方法由中国食品药品检定研究院(中检院)牵头,联合我国主要的CV-A16灭活疫苗研发单位,共计6个实验室,采用协标试剂盒,分别对两个相同、编盲设置的...目的建立第一代国家柯萨奇病毒A组16型(CV-A16)抗原标准品,用于CV-A16疫苗的抗原含量检测.方法由中国食品药品检定研究院(中检院)牵头,联合我国主要的CV-A16灭活疫苗研发单位,共计6个实验室,采用协标试剂盒,分别对两个相同、编盲设置的候选CV-A16抗原标准品(A、B)进行CV-A16抗原含量协作标定.并且分别采用各实验室建立的CV-A16抗原检测试剂盒和各自工艺制备的CV-A16疫苗原液,以候选标准品为标准进行适用性研究.结果各实验室A/B相对抗原含量比为0.978~1.082(CV:6.2%~12.4%),表明各实验室检测结果准确、可靠.故将A、B结果合并分析.候选标准品(A、B)的几何均值为2194.5kU/ml,几何变异系数(geometric coefficient of variation,GCV)为11.0%,且协标结果呈正态分布,符合标准品研制要求.将候选标准品的抗原含量暂定为2000U/ml进行适用性研究,共3家实验室完成该研究,结果显示3个采用各自工艺制备的CV-A16原液,在各自建立的CV-A16检测试剂盒上均与候选标准品具有良好的线性和平行性,适用性良好.结论建立的候选标准品可作为CV-A16抗原标准品,赋值为2000U/ml,用于CV-A16疫苗的抗原含量检测.展开更多
目的评价我国三家企业生产的肠道病毒71型(EV-A71)灭活疫苗的小鼠中和抗体应答水平和攻毒保护能力,为了解新上市EV-A71疫苗的免疫保护特性提供基础.方法应用小鼠模型,分别对上市的3家企业EV-A71灭活疫苗(编盲为A、B、C疫苗)进行中和抗...目的评价我国三家企业生产的肠道病毒71型(EV-A71)灭活疫苗的小鼠中和抗体应答水平和攻毒保护能力,为了解新上市EV-A71疫苗的免疫保护特性提供基础.方法应用小鼠模型,分别对上市的3家企业EV-A71灭活疫苗(编盲为A、B、C疫苗)进行中和抗体应答水平、被动免疫和主动免疫攻毒保护研究.结果一剂人用剂量A、B和C疫苗免疫后,EV-A71中和抗体几何均滴度(geometric mean titer,GMT)分别为331、132和69U/ml,A疫苗显著高于B疫苗和C疫苗(P<0.05).应用3家疫苗免疫血清被动保护,结果显示半数有效剂量(ED50)分别为1.9、50.4和8.2U/ml,提示3家疫苗免疫抗体均具有良好的保护能力,但随抗体稀释倍数的增加保护率下降趋势不同.EV-A71疫苗免疫主动保护结果显示,4倍稀释的3家EV-A71疫苗一针免疫即可获得100%的保护效果,但同样随剂量降低,保护率下降趋势不同,一针和二针免疫保护的ED50值分别为人用疫苗剂量的203.2、24.4和41.5倍,及396.4、121.4和127.5倍.结论我国不同厂家EV-A71灭活疫苗一针免疫即可获得良好的免疫应答和保护能力,抗体应答和保护水平与临床前研究一致,但三家疫苗特性存在一定差异,应进一步深入开展相关基础研究,充分保证上市后EV-A71疫苗的有效性.展开更多
文摘This article mainly discussed bulk material lHvl^ared by powder metallurgy, and the commercial 2024 aluminum alloy powder and FeNiCrCoA13 high entropy alloy powder （both produced by argon gas atomization process） were ball-milled for different hours. The prepared powder was consolidated by hot extrusion method. The microstruetures of the milled powder and bulk alloy were examined by X - Ray Diffraction （XRD）, Scanning Electron Microscopy （SEM） and Transmission Electron Microscopy （TEM）. The thermal stability was tested by differential scanning calorimetry （DSC）. Mechanical properties of the extruded alloy were examined by Vickers hardness tester and mechanical testing machine. The results show that after milling, the mixed particle sizes and microstructures of the alloy powder change obviously. The compressive strength of the extruded alloy has reached 580 MPa under certain conditions of milling time and composition.
文摘目的分析相关疫苗上市后中国大陆肠道病毒71型(enterovirus type 71,EV71)C4亚型的分子流行特征。方法基于贝叶斯的马尔可夫链蒙特卡罗(markov chain monte carlo,MCMC)分析方法,对EV71疫苗上市前后中国大陆EV71毒株VP1基因相似性进行比较。应用贝叶斯天际线模型和SpreaD3 v0.9.6软件对中国大陆C4亚型病毒进行系统发生地理学分析,通过绘制贝叶斯天际线图描绘种群动态历史变化,并应用EasyCodeML软件分析正选择压力位点。结果中国大陆EV71 C4亚型VP1基因序列的平均进化速率为2.25×10-3 site/year,C4a亚型毒株平均进化速率为3.1×10-3 site/year;EV71 C4亚型的起源可追溯至1990年的华东地区,C4a亚型可能起源于1999年。2002—2007年C4亚型经历了种群规模扩张,种群规模于2007年达峰值,且在EV71疫苗上市后仍保持较高水平。C4亚型病毒VP1基因中有5个氨基酸位点承受正选择压力,比对分析EV71疫苗上市后2015—2018年C4亚型病毒序列,筛选到VP1基因第289位点承受正选择压力。结论本研究揭示了EV71 C4亚型的遗传进化信息,为制定手足口病(hand,foot and mouth disease,HFMD)的防控策略提供了科学的数据支持。
基金Sponsored by the National Basic Research Development Program of China(973 Program)(Grant No.2012CB619503)National High Technology Research and Development Program of China(863 Program)(Grant No.2013AA031001)International S&T Cooperation Program of China(Grant No.2012DFA50630)
文摘2024 Aluminum alloy powder( 60wt%) and Fe-based amorphous powder( 40 wt%) were adopted. They were mechanical machined for 48hours after being mixed. Bulk material was gained after Spark Plasma Sintering. The sintering parameters included sintering temperature,heating or cooling rates,pressure and holding time. 300 ℃- 800 ℃ were adopted while the heating or cooling rate was 100 ℃ / min and with the pressure of 50 MPa in the experiments. The holding time was 10 min or 20 min at different temperatures, respectively. Bulk materials after sintering were examined by Scanning Electron Microscopy and X-Ray Diffraction. The micro-hardness and relative density also were tested. The sintering temperature had the most significant influence on the microstructure and property of the bulk material. The influence of holding time came second while the heating or cooling rates and pressure were fixed. The density became larger with the increase of the temperature. The compactness was best at 500℃. The pressure and generation of high-temperature phases were the factors which affected the density and the compactness.
文摘目的建立第一代国家柯萨奇病毒A组16型(CV-A16)抗原标准品,用于CV-A16疫苗的抗原含量检测.方法由中国食品药品检定研究院(中检院)牵头,联合我国主要的CV-A16灭活疫苗研发单位,共计6个实验室,采用协标试剂盒,分别对两个相同、编盲设置的候选CV-A16抗原标准品(A、B)进行CV-A16抗原含量协作标定.并且分别采用各实验室建立的CV-A16抗原检测试剂盒和各自工艺制备的CV-A16疫苗原液,以候选标准品为标准进行适用性研究.结果各实验室A/B相对抗原含量比为0.978~1.082(CV:6.2%~12.4%),表明各实验室检测结果准确、可靠.故将A、B结果合并分析.候选标准品(A、B)的几何均值为2194.5kU/ml,几何变异系数(geometric coefficient of variation,GCV)为11.0%,且协标结果呈正态分布,符合标准品研制要求.将候选标准品的抗原含量暂定为2000U/ml进行适用性研究,共3家实验室完成该研究,结果显示3个采用各自工艺制备的CV-A16原液,在各自建立的CV-A16检测试剂盒上均与候选标准品具有良好的线性和平行性,适用性良好.结论建立的候选标准品可作为CV-A16抗原标准品,赋值为2000U/ml,用于CV-A16疫苗的抗原含量检测.
文摘目的评价我国三家企业生产的肠道病毒71型(EV-A71)灭活疫苗的小鼠中和抗体应答水平和攻毒保护能力,为了解新上市EV-A71疫苗的免疫保护特性提供基础.方法应用小鼠模型,分别对上市的3家企业EV-A71灭活疫苗(编盲为A、B、C疫苗)进行中和抗体应答水平、被动免疫和主动免疫攻毒保护研究.结果一剂人用剂量A、B和C疫苗免疫后,EV-A71中和抗体几何均滴度(geometric mean titer,GMT)分别为331、132和69U/ml,A疫苗显著高于B疫苗和C疫苗(P<0.05).应用3家疫苗免疫血清被动保护,结果显示半数有效剂量(ED50)分别为1.9、50.4和8.2U/ml,提示3家疫苗免疫抗体均具有良好的保护能力,但随抗体稀释倍数的增加保护率下降趋势不同.EV-A71疫苗免疫主动保护结果显示,4倍稀释的3家EV-A71疫苗一针免疫即可获得100%的保护效果,但同样随剂量降低,保护率下降趋势不同,一针和二针免疫保护的ED50值分别为人用疫苗剂量的203.2、24.4和41.5倍,及396.4、121.4和127.5倍.结论我国不同厂家EV-A71灭活疫苗一针免疫即可获得良好的免疫应答和保护能力,抗体应答和保护水平与临床前研究一致,但三家疫苗特性存在一定差异,应进一步深入开展相关基础研究,充分保证上市后EV-A71疫苗的有效性.
