目的比较不同炮制条件对地骨皮化学成分的影响,优选饮片炮制方法。方法采用HPLC-IT-TOF/MS;ZORBAX SB-Aq C_(18)色谱柱;流动相为0.1%甲酸水溶液-乙腈梯度洗脱;柱温40℃;流速0.3 mL/min;进样体积5μL;电喷雾离子源(Electrospray Ionizati...目的比较不同炮制条件对地骨皮化学成分的影响,优选饮片炮制方法。方法采用HPLC-IT-TOF/MS;ZORBAX SB-Aq C_(18)色谱柱;流动相为0.1%甲酸水溶液-乙腈梯度洗脱;柱温40℃;流速0.3 mL/min;进样体积5μL;电喷雾离子源(Electrospray Ionization,ESI),正、负离子模式下扫描,根据相对分子质量和碎片离子等质谱信息,结合文献信息以及数据库鉴定化学成分,并以各成分的离子峰面积比作为不同炮制品的变化指数进行比较。根据鉴定结果将地骨皮5种主要活性成分的相对含量进行逼近理想解排序法分析(technique for order preference by similarity to ideal solution,TOPSIS),以客观评价经不同炮制方法所得地骨皮的品质。结果共鉴定23种化合物,其中亚麻酸在烘干80℃、焙干100℃时消失,甜菜碱在淘洗2次后消失。地骨皮在不同炮制方法下各成分含量差异较大,随着淘洗次数的增加,地骨皮中成分含量迅速下降;甜菜碱含量随着烘制温度的升高而升高,相反咖啡酰丁二胺含量会随着烘制温度的升高而降低;地骨皮甲素、地骨皮乙素均在50℃烘干时含量最高,绿原酸晒干时含量最高。通过对7种地骨皮样品进行综合评价分析,发现30℃晒干,淘洗1次(S1)为最佳炮制方式。结论地骨皮各炮制品中化合物种类和成分均发生变化;S1为最佳炮制方式。阐明了经不同炮制方法后地骨皮成分变化规律,并为地骨皮质量控制和评价奠定基础。展开更多
目的:采用UPLC-Q-TOF-MS法测定扶正膏药渣中特女贞苷、丹皮酚、芒柄花素、藁本内酯的含量。方法:采用安捷伦ZORBAX Eclipse Plus C 18柱(3.0 mm×100 mm,1.8μm),以乙腈-0.05 mmol·L^(-1)甲酸铵溶液为流动相进行梯度洗脱,流速...目的:采用UPLC-Q-TOF-MS法测定扶正膏药渣中特女贞苷、丹皮酚、芒柄花素、藁本内酯的含量。方法:采用安捷伦ZORBAX Eclipse Plus C 18柱(3.0 mm×100 mm,1.8μm),以乙腈-0.05 mmol·L^(-1)甲酸铵溶液为流动相进行梯度洗脱,流速为0.4 mL/min,进样量为2.0μL,柱温为30℃;质谱条件如下:离子源为ESI,正、负模式下采集数据,喷雾电压4000 V;离子化温度325℃,外标法定量。结果:特女贞苷、丹皮酚、芒柄花素、藁本内酯的线性范围分别为1.0~100.0,1.0~100.0,1.1~112.0,0.5~50.0μg/L,且线性关系均良好(R≥0.9990);精密度、稳定性、重复性试验结果显示4个中药成分的峰面积RSD均≤5.0%;4个中药成分的平均加样回收率分别为94.90%~109.14%(RSD<4.0%,n=6)。结论:建立的UPLC-Q-TOF-MS法检测扶正膏药渣中的特女贞苷、丹皮酚、芒柄花素、藁本内酯的含量结果准确可靠,证实了药渣中还残留一定量的活性成分,具有一定的营养价值,为药渣的综合开发利用提供依据。展开更多
To increase spatial resolution and signal-to-noise ratio in PET imaging,we present in this paper the design and performance evaluation of a PET detector module combining both depth-of-interaction(DOI) and time-offligh...To increase spatial resolution and signal-to-noise ratio in PET imaging,we present in this paper the design and performance evaluation of a PET detector module combining both depth-of-interaction(DOI) and time-offlight(TOF) capabilities.The detector module consists of a staggered dual-layer LYSO block with2 mm × 2 mm × 7 mm crystals.MR-compatible SiPM sensors(MicroFJ-30035-TSV,SensL) are assembled into an 8× 8 array.SiPM signals from both fast and slow outputs are read out by a 128-channel ASIC chip.To test its performance,a flood histogram is acquired with a ^(22)Na point source on top of the detector,and the energy resolution and the coincidence resolving time(CRT) value for each individual crystal are measured.The flood histogram shows excellent crystal separation in both layers.The average energy resolution at 511 keV is 14.0 and 12.7%at the bottom and top layers,respectively.The average CRT of a single crystal is 635 and 565 ps at the bottom and top layers,respectively.In conclusion,the compact DOI-TOF PET detector module is of excellent crystal identification capability,good energy resolution and reasonable time resolution and has promising application prospective in clinical TOF PET,PET/MRI,and brain PET systems.展开更多
Detecting feature points on the human body in video frames is a key step for tracking human movements. There have been methods developed that leverage models of human pose and classification of pixels of the body imag...Detecting feature points on the human body in video frames is a key step for tracking human movements. There have been methods developed that leverage models of human pose and classification of pixels of the body image. Yet, occlusion and robustness are still open challenges. In this paper, we present an automatic, model-free feature point detection and action tracking method using a time-of-flight camera. Our method automatically detects feature points for movement abstraction. To overcome errors caused by miss-detection and occlusion, a refinement method is devised that uses the trajectory of the feature points to correct the erroneous detections. Experiments were conducted using videos acquired with a Microsoft Kinect camera and a publicly available video set and comparisons were conducted with the state-of-the-art methods. The results demonstrated that our proposed method delivered improved and reliable performance with an average accuracy in the range of 90 %.The trajectorybased refinement also demonstrated satisfactory effectiveness that recovers the detection with a success rate of 93.7 %. Our method processed a frame in an average time of 71.1 ms.展开更多
文摘目的比较不同炮制条件对地骨皮化学成分的影响,优选饮片炮制方法。方法采用HPLC-IT-TOF/MS;ZORBAX SB-Aq C_(18)色谱柱;流动相为0.1%甲酸水溶液-乙腈梯度洗脱;柱温40℃;流速0.3 mL/min;进样体积5μL;电喷雾离子源(Electrospray Ionization,ESI),正、负离子模式下扫描,根据相对分子质量和碎片离子等质谱信息,结合文献信息以及数据库鉴定化学成分,并以各成分的离子峰面积比作为不同炮制品的变化指数进行比较。根据鉴定结果将地骨皮5种主要活性成分的相对含量进行逼近理想解排序法分析(technique for order preference by similarity to ideal solution,TOPSIS),以客观评价经不同炮制方法所得地骨皮的品质。结果共鉴定23种化合物,其中亚麻酸在烘干80℃、焙干100℃时消失,甜菜碱在淘洗2次后消失。地骨皮在不同炮制方法下各成分含量差异较大,随着淘洗次数的增加,地骨皮中成分含量迅速下降;甜菜碱含量随着烘制温度的升高而升高,相反咖啡酰丁二胺含量会随着烘制温度的升高而降低;地骨皮甲素、地骨皮乙素均在50℃烘干时含量最高,绿原酸晒干时含量最高。通过对7种地骨皮样品进行综合评价分析,发现30℃晒干,淘洗1次(S1)为最佳炮制方式。结论地骨皮各炮制品中化合物种类和成分均发生变化;S1为最佳炮制方式。阐明了经不同炮制方法后地骨皮成分变化规律,并为地骨皮质量控制和评价奠定基础。
文摘目的:采用UPLC-Q-TOF-MS法测定扶正膏药渣中特女贞苷、丹皮酚、芒柄花素、藁本内酯的含量。方法:采用安捷伦ZORBAX Eclipse Plus C 18柱(3.0 mm×100 mm,1.8μm),以乙腈-0.05 mmol·L^(-1)甲酸铵溶液为流动相进行梯度洗脱,流速为0.4 mL/min,进样量为2.0μL,柱温为30℃;质谱条件如下:离子源为ESI,正、负模式下采集数据,喷雾电压4000 V;离子化温度325℃,外标法定量。结果:特女贞苷、丹皮酚、芒柄花素、藁本内酯的线性范围分别为1.0~100.0,1.0~100.0,1.1~112.0,0.5~50.0μg/L,且线性关系均良好(R≥0.9990);精密度、稳定性、重复性试验结果显示4个中药成分的峰面积RSD均≤5.0%;4个中药成分的平均加样回收率分别为94.90%~109.14%(RSD<4.0%,n=6)。结论:建立的UPLC-Q-TOF-MS法检测扶正膏药渣中的特女贞苷、丹皮酚、芒柄花素、藁本内酯的含量结果准确可靠,证实了药渣中还残留一定量的活性成分,具有一定的营养价值,为药渣的综合开发利用提供依据。
基金supported in part by Fundamental Research Funds for the Central Universities(No.FRF-TP-15-114A1)National Natural Science Foundation of China(Nos.11375096,11505300)Tsinghua University Initiative Scientific Research Program(No.20131089289)
文摘To increase spatial resolution and signal-to-noise ratio in PET imaging,we present in this paper the design and performance evaluation of a PET detector module combining both depth-of-interaction(DOI) and time-offlight(TOF) capabilities.The detector module consists of a staggered dual-layer LYSO block with2 mm × 2 mm × 7 mm crystals.MR-compatible SiPM sensors(MicroFJ-30035-TSV,SensL) are assembled into an 8× 8 array.SiPM signals from both fast and slow outputs are read out by a 128-channel ASIC chip.To test its performance,a flood histogram is acquired with a ^(22)Na point source on top of the detector,and the energy resolution and the coincidence resolving time(CRT) value for each individual crystal are measured.The flood histogram shows excellent crystal separation in both layers.The average energy resolution at 511 keV is 14.0 and 12.7%at the bottom and top layers,respectively.The average CRT of a single crystal is 635 and 565 ps at the bottom and top layers,respectively.In conclusion,the compact DOI-TOF PET detector module is of excellent crystal identification capability,good energy resolution and reasonable time resolution and has promising application prospective in clinical TOF PET,PET/MRI,and brain PET systems.
文摘Detecting feature points on the human body in video frames is a key step for tracking human movements. There have been methods developed that leverage models of human pose and classification of pixels of the body image. Yet, occlusion and robustness are still open challenges. In this paper, we present an automatic, model-free feature point detection and action tracking method using a time-of-flight camera. Our method automatically detects feature points for movement abstraction. To overcome errors caused by miss-detection and occlusion, a refinement method is devised that uses the trajectory of the feature points to correct the erroneous detections. Experiments were conducted using videos acquired with a Microsoft Kinect camera and a publicly available video set and comparisons were conducted with the state-of-the-art methods. The results demonstrated that our proposed method delivered improved and reliable performance with an average accuracy in the range of 90 %.The trajectorybased refinement also demonstrated satisfactory effectiveness that recovers the detection with a success rate of 93.7 %. Our method processed a frame in an average time of 71.1 ms.
