[ Objective ] This study aimed to investigate the major contributors to the measurement uncertainty in quantitative analysis of genetically modified ingreclients and improve the quality of quantitative detection of ge...[ Objective ] This study aimed to investigate the major contributors to the measurement uncertainty in quantitative analysis of genetically modified ingreclients and improve the quality of quantitative detection of genetically modified components. [ Method] The content of CaMV35S promoter （parameter） in GTS40- 3-2 soybean powder samples was measured to estimate the measurement uncertainty preliminarily. [ Result] Type A uncertainty （uA） ＇ type B uncertainty （uB） and combined standard uncertainty （Uc） were 0.0 004, 0.002 and 0.002, respectively. At a confidence level ofp = 95% and freedom degree of Voff = 3 251, coverage factor k = 1.96, expanded uncertainty U = 0.004. The final measurement result was C = 0.028 ± 0. 004, which was dose to the conventional true value （0.03）. Thus, the measurement uncertainty was relatively small, indicating a high quality of measurement. In this study, uncertainty evaluation indicated that the deviation of micro liquid transfer made the greatest contribution to the measurement uncertainty. [ Cludusion ] The deviation of micro liquid transfer should be reduced to im- prove the quality of measurement.展开更多
Oxidative stress, a predominant cause of apoptosis cascades triggered in neurodegenerative disorders, has been regarded as a critical inducement in the pathogenesis of Alzheimer's disease(AD). Gou Teng-San(GTS) is...Oxidative stress, a predominant cause of apoptosis cascades triggered in neurodegenerative disorders, has been regarded as a critical inducement in the pathogenesis of Alzheimer's disease(AD). Gou Teng-San(GTS) is a traditional Chinese herbs preparation commonly utilized to alleviate cognitive dysfunction and psychological symptoms of patients with dementia. The present study aimed to investigate the protective effects of GTS40, an active fraction of GTS, on H_2O_2-induced oxidative damage and identify the potential active ingredients. Our results revealed that GTS40 exhibited radical scavenging activity, elevated cell viability, decreased the levels of intracellular reactive oxygen species(ROS), and stabilized mitochondrial transmembrane potential(MMP) in H_2O_2-treated PC12 cells. In addition, GTS40 blocked the apoptotic cascade by reversing the imbalance of Bcl-2/Bax and inhibiting the activity of caspase-3. Furthermore, an HPLC-QTOFMS method was developed to characterize major chemical constituents in GTS40. Our results revealed twenty-seven identified or tentatively characterized compounds through comparing their retention time(t_R) and MS spectra with reference standards. These results suggested that GTS40 was a promising active fraction that may be beneficial in the prevention and treatment of oxidative stress-mediated neurodegenerative disorders.展开更多
首次以转基因大豆中结构特异性基因为靶基因,建立了特异的微滴式数字QX200 PCR(Droplet digital PCR,ddPCR)检测方法,对其进行准确定量。结果表明:ddPCR对结构特异性基因的检出限为2拷贝/(20μL),检测灵敏度高于国标中qPCR方法。微滴式...首次以转基因大豆中结构特异性基因为靶基因,建立了特异的微滴式数字QX200 PCR(Droplet digital PCR,ddPCR)检测方法,对其进行准确定量。结果表明:ddPCR对结构特异性基因的检出限为2拷贝/(20μL),检测灵敏度高于国标中qPCR方法。微滴式数字PCR方法是一种准确、高灵敏度的基因拷贝数的分析方法,操作简便,可在转基因检测领域广泛应用。展开更多
保时捷、奥迪之流以至仍在嗫泣的丰田带同一尘不染的卡车大军压境不过短短两个星期后，这条赛道便迎来一支老兵军团大开怀旧派对，尽管所谓怀旧其实横跨1923至1993年。勒芒古典车赛（Le Mans Classic）欢迎任何年份介乎战前布加迪、机...保时捷、奥迪之流以至仍在嗫泣的丰田带同一尘不染的卡车大军压境不过短短两个星期后，这条赛道便迎来一支老兵军团大开怀旧派对，尽管所谓怀旧其实横跨1923至1993年。勒芒古典车赛（Le Mans Classic）欢迎任何年份介乎战前布加迪、机械增压宾利、D-Type、GT40至到惊世C组怪物的古典汽车参与，参赛车辆一律按年份分组从白昼斗至晚上，而且是真刀真枪大斗法，堪称怀旧风味最浓的运动。展开更多
基金Supported by Project of Standardized Technology System of Sichuan Bureau of Quality and Technical Supervision(ZYBZ2013-39)
文摘[ Objective ] This study aimed to investigate the major contributors to the measurement uncertainty in quantitative analysis of genetically modified ingreclients and improve the quality of quantitative detection of genetically modified components. [ Method] The content of CaMV35S promoter （parameter） in GTS40- 3-2 soybean powder samples was measured to estimate the measurement uncertainty preliminarily. [ Result] Type A uncertainty （uA） ＇ type B uncertainty （uB） and combined standard uncertainty （Uc） were 0.0 004, 0.002 and 0.002, respectively. At a confidence level ofp = 95% and freedom degree of Voff = 3 251, coverage factor k = 1.96, expanded uncertainty U = 0.004. The final measurement result was C = 0.028 ± 0. 004, which was dose to the conventional true value （0.03）. Thus, the measurement uncertainty was relatively small, indicating a high quality of measurement. In this study, uncertainty evaluation indicated that the deviation of micro liquid transfer made the greatest contribution to the measurement uncertainty. [ Cludusion ] The deviation of micro liquid transfer should be reduced to im- prove the quality of measurement.
基金supported by the National Natural Science Foundation of China(Nos.81373956 and J1310032)
文摘Oxidative stress, a predominant cause of apoptosis cascades triggered in neurodegenerative disorders, has been regarded as a critical inducement in the pathogenesis of Alzheimer's disease(AD). Gou Teng-San(GTS) is a traditional Chinese herbs preparation commonly utilized to alleviate cognitive dysfunction and psychological symptoms of patients with dementia. The present study aimed to investigate the protective effects of GTS40, an active fraction of GTS, on H_2O_2-induced oxidative damage and identify the potential active ingredients. Our results revealed that GTS40 exhibited radical scavenging activity, elevated cell viability, decreased the levels of intracellular reactive oxygen species(ROS), and stabilized mitochondrial transmembrane potential(MMP) in H_2O_2-treated PC12 cells. In addition, GTS40 blocked the apoptotic cascade by reversing the imbalance of Bcl-2/Bax and inhibiting the activity of caspase-3. Furthermore, an HPLC-QTOFMS method was developed to characterize major chemical constituents in GTS40. Our results revealed twenty-seven identified or tentatively characterized compounds through comparing their retention time(t_R) and MS spectra with reference standards. These results suggested that GTS40 was a promising active fraction that may be beneficial in the prevention and treatment of oxidative stress-mediated neurodegenerative disorders.
文摘首次以转基因大豆中结构特异性基因为靶基因,建立了特异的微滴式数字QX200 PCR(Droplet digital PCR,ddPCR)检测方法,对其进行准确定量。结果表明:ddPCR对结构特异性基因的检出限为2拷贝/(20μL),检测灵敏度高于国标中qPCR方法。微滴式数字PCR方法是一种准确、高灵敏度的基因拷贝数的分析方法,操作简便,可在转基因检测领域广泛应用。
文摘保时捷、奥迪之流以至仍在嗫泣的丰田带同一尘不染的卡车大军压境不过短短两个星期后，这条赛道便迎来一支老兵军团大开怀旧派对，尽管所谓怀旧其实横跨1923至1993年。勒芒古典车赛（Le Mans Classic）欢迎任何年份介乎战前布加迪、机械增压宾利、D-Type、GT40至到惊世C组怪物的古典汽车参与，参赛车辆一律按年份分组从白昼斗至晚上，而且是真刀真枪大斗法，堪称怀旧风味最浓的运动。
