An indirect competitive fluorescence immunoassay using a DNA/dye conjugate as antibody multiple labels was developed on 96-well plates for the identification and quantification of 2,2＇,4,4＇-tetrabromodiphenyl ether ...An indirect competitive fluorescence immunoassay using a DNA/dye conjugate as antibody multiple labels was developed on 96-well plates for the identification and quantification of 2,2＇,4,4＇-tetrabromodiphenyl ether （BDE-47） in aqueous samples. A hapten, 2,4,2＇- tribromodiphenyl ether-4＇-aldehyde, was synthesized, and was conjugated to bovine serum albumin to form a coating antigen. Specific recognition of the antigen by anti-PBDE antiserum was confirmed by a surface plasmon resonance measurement. In the immunoassay, the coating antigen was adsorbed on a 96-well plate first, and a sample, antiserum and biotinylated goat anti-rabbit secondary antibody were then added and reacted sequentially. A biotinylated, double-stranded DNA with 219 base pairs was attached to the secondary antibody by using streptavidin as a molecular bridge. In situ multiple labeling of the antibody was accomplished after addition of a DNA-binding fluorescent dye, SYBR Green I. The working range of the immunoassay for the BDE-47 standard was 3.1-390 ~tg/L, with an IC50 value of 15.6 Ixg/L. The calculated LOD of the immunoassay is 0.73 Ixg/L. The immunoassay demonstrated relatively high selectivity for BDE-47, showing very low cross-reactivity （〈 3%） with BDE-15, BDE-153 and BDE-209. With a spiked river water sample containing 50 Izg/L BDE-47, quantification by the immunoassay was 41.9 ~tg/L, which compared well with the standard GC-ECD method （45.7 Ixg/L）. The developed immunoassay provides a rapid screening tool for polybrominated diphenyl ethers in environmental samples.展开更多
Arterial spin labeling(ASL) is a magnetic resonance imaging technique for measuring tissue perfusion using a freely diffusible intrinsic tracer.As compared with other perfusion techniques,ASL offers several advantages...Arterial spin labeling(ASL) is a magnetic resonance imaging technique for measuring tissue perfusion using a freely diffusible intrinsic tracer.As compared with other perfusion techniques,ASL offers several advantages and is now available for routine clinical practice in many institutions.Its noninvasive nature and ability to quantitatively measure tissue perfusion make ASL ideal for research and clinical studies.Recent technical advances have increased its sensitivity and also extended its potential applications.This review focuses on some basic knowledge of ASL perfusion,emerging techniques and clinical applications in neuroimaging.展开更多
目的采用三维准连续脉冲动脉自旋标记(3D pseudocontinuous arterial spin labeling,3D p CASL)技术研究复发缓解型多发性硬化(relapsing-remitting multiple sclerosis,RRMS)患者看似正常的脑白质区(normal appearing white matter,NA...目的采用三维准连续脉冲动脉自旋标记(3D pseudocontinuous arterial spin labeling,3D p CASL)技术研究复发缓解型多发性硬化(relapsing-remitting multiple sclerosis,RRMS)患者看似正常的脑白质区(normal appearing white matter,NAWM)脑血流量(cerebral blood flow,CBF)变化,并分析其临床相关性。材料与方法本研究共纳入29例RRMS患者及年龄性别完全匹配的17名健康志愿者。所有受试者通过GE公司的3.0 T MR采集了T2加权成像(T2weighted image,T2WI)、三维快速扰相梯度回波序列(3-dimensional fast spoiled gradient echo,3D-FSPGR)及3D p CASL。将3D p CASL标准化配准后在半卵圆中心NAWM、侧脑室旁NAWM手绘感兴趣区,得到两个区域的平均CBF值。采用两独立样本t检验比较RRMS和健康志愿者的NAWM CBF值的差异,并将CBF值与临床资料进行相关性分析。结果与健康志愿者比较,RRMS患者半卵圆中心NAWM及侧脑室旁NAWM的CBF值明显降低(半卵圆中心NAWM:32.5452±4.5848 vs 35.4865±5.7968,P=0.036;侧脑室旁NAWM:30.7788±4.1746 vs 34.0530±4.4821,P=0.006)。RRMS患者半卵圆中心NAWM及侧脑室旁NAWM的CBF值与患者的年龄、发病年龄、发病次数、病程、扩展残疾状态量表(expanded disability status scale,EDSS)评分没有明显相关性。结论采用3D p CASL技术定量分析RRMS患者微循环的脑血流灌注情况发现,在常规MRI没有明显病变的NAWM的CBF值明显降低。该研究表明RRMS患者NAWM存在潜在的血流动力学改变,进一步提示血流动力学因素在RRMS患者的发病中可能起着重要的作用。展开更多
建立了定量肽段串联体蛋白质(concatamers of Q peptides,QconCATs)结合18O同位素标记-多反应监测质谱的蛋白质绝对定量新方法。首先对QconCAT重组蛋白质进行了纯度表征,十二烷基硫酸钠-聚丙烯酰胺凝胶电泳(SDS-PAGE)表征结果表明重组...建立了定量肽段串联体蛋白质(concatamers of Q peptides,QconCATs)结合18O同位素标记-多反应监测质谱的蛋白质绝对定量新方法。首先对QconCAT重组蛋白质进行了纯度表征,十二烷基硫酸钠-聚丙烯酰胺凝胶电泳(SDS-PAGE)表征结果表明重组蛋白质的纯度在99%以上,相对分子质量约为63.4 kDa。对QconCAT重组蛋白质酶切后的肽段混合物进行质谱分析,并经pFind和pLabel软件处理,验证了目标肽段。还考察了QconCAT重组蛋白质的酶切效率和18O标记效率,并对QconCAT蛋白质结合18O标记-同位素稀释-多反应监测质谱方法进行了评价。实验结果表明,采用该方法对腾冲嗜热厌氧菌(Thermoanaerobacter tengcongensis,TTE)中选定蛋白质的肽段进行绝对含量测定时,相对标准偏差小于20%,准确度较高,说明该方法可用于复杂生物样本中蛋白质的绝对定量。更重要的是所建方法不仅解决了细胞培养氨基酸稳定同位素标记(SILAC)技术的重标试剂价格昂贵的问题,也为定量蛋白质组学提供了一种新的方法。展开更多
In this paper a decision support system for systematically evaluating the impact of labeling products with their carbon footprints is developed and applied to prioritize products for carbon labeling in a large superma...In this paper a decision support system for systematically evaluating the impact of labeling products with their carbon footprints is developed and applied to prioritize products for carbon labeling in a large supermarket chain in the UK.Carbon labels may change consumers’ behavior and encourage suppliers to implement carbon-reduction solutions.Those changes may,however,lead to unintended risks.To handle the challenges of uncertainties in the evaluation,the Evidential Reasoning approach and the Intelligent Decision System software for multi-criteria decision analysis are applied to support the process.The system developed can be applied to assessing the impact of sustainable development policies to maximize their benefits and minimize their risks.展开更多
基金supported by the Chinese Academy of Sciences (No. KSSCX2-YW-G-059)the National Hi-Tech Research and Development Program of China (No.2007AA06A407)the National Natural Science Foundation of China (No. 20825519, 20890112, 20921063)
文摘An indirect competitive fluorescence immunoassay using a DNA/dye conjugate as antibody multiple labels was developed on 96-well plates for the identification and quantification of 2,2＇,4,4＇-tetrabromodiphenyl ether （BDE-47） in aqueous samples. A hapten, 2,4,2＇- tribromodiphenyl ether-4＇-aldehyde, was synthesized, and was conjugated to bovine serum albumin to form a coating antigen. Specific recognition of the antigen by anti-PBDE antiserum was confirmed by a surface plasmon resonance measurement. In the immunoassay, the coating antigen was adsorbed on a 96-well plate first, and a sample, antiserum and biotinylated goat anti-rabbit secondary antibody were then added and reacted sequentially. A biotinylated, double-stranded DNA with 219 base pairs was attached to the secondary antibody by using streptavidin as a molecular bridge. In situ multiple labeling of the antibody was accomplished after addition of a DNA-binding fluorescent dye, SYBR Green I. The working range of the immunoassay for the BDE-47 standard was 3.1-390 ~tg/L, with an IC50 value of 15.6 Ixg/L. The calculated LOD of the immunoassay is 0.73 Ixg/L. The immunoassay demonstrated relatively high selectivity for BDE-47, showing very low cross-reactivity （〈 3%） with BDE-15, BDE-153 and BDE-209. With a spiked river water sample containing 50 Izg/L BDE-47, quantification by the immunoassay was 41.9 ~tg/L, which compared well with the standard GC-ECD method （45.7 Ixg/L）. The developed immunoassay provides a rapid screening tool for polybrominated diphenyl ethers in environmental samples.
文摘Arterial spin labeling(ASL) is a magnetic resonance imaging technique for measuring tissue perfusion using a freely diffusible intrinsic tracer.As compared with other perfusion techniques,ASL offers several advantages and is now available for routine clinical practice in many institutions.Its noninvasive nature and ability to quantitatively measure tissue perfusion make ASL ideal for research and clinical studies.Recent technical advances have increased its sensitivity and also extended its potential applications.This review focuses on some basic knowledge of ASL perfusion,emerging techniques and clinical applications in neuroimaging.
文摘目的采用三维准连续脉冲动脉自旋标记(3D pseudocontinuous arterial spin labeling,3D p CASL)技术研究复发缓解型多发性硬化(relapsing-remitting multiple sclerosis,RRMS)患者看似正常的脑白质区(normal appearing white matter,NAWM)脑血流量(cerebral blood flow,CBF)变化,并分析其临床相关性。材料与方法本研究共纳入29例RRMS患者及年龄性别完全匹配的17名健康志愿者。所有受试者通过GE公司的3.0 T MR采集了T2加权成像(T2weighted image,T2WI)、三维快速扰相梯度回波序列(3-dimensional fast spoiled gradient echo,3D-FSPGR)及3D p CASL。将3D p CASL标准化配准后在半卵圆中心NAWM、侧脑室旁NAWM手绘感兴趣区,得到两个区域的平均CBF值。采用两独立样本t检验比较RRMS和健康志愿者的NAWM CBF值的差异,并将CBF值与临床资料进行相关性分析。结果与健康志愿者比较,RRMS患者半卵圆中心NAWM及侧脑室旁NAWM的CBF值明显降低(半卵圆中心NAWM:32.5452±4.5848 vs 35.4865±5.7968,P=0.036;侧脑室旁NAWM:30.7788±4.1746 vs 34.0530±4.4821,P=0.006)。RRMS患者半卵圆中心NAWM及侧脑室旁NAWM的CBF值与患者的年龄、发病年龄、发病次数、病程、扩展残疾状态量表(expanded disability status scale,EDSS)评分没有明显相关性。结论采用3D p CASL技术定量分析RRMS患者微循环的脑血流灌注情况发现,在常规MRI没有明显病变的NAWM的CBF值明显降低。该研究表明RRMS患者NAWM存在潜在的血流动力学改变,进一步提示血流动力学因素在RRMS患者的发病中可能起着重要的作用。
文摘In this paper a decision support system for systematically evaluating the impact of labeling products with their carbon footprints is developed and applied to prioritize products for carbon labeling in a large supermarket chain in the UK.Carbon labels may change consumers’ behavior and encourage suppliers to implement carbon-reduction solutions.Those changes may,however,lead to unintended risks.To handle the challenges of uncertainties in the evaluation,the Evidential Reasoning approach and the Intelligent Decision System software for multi-criteria decision analysis are applied to support the process.The system developed can be applied to assessing the impact of sustainable development policies to maximize their benefits and minimize their risks.
