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Traditional Chinese medicine (TCM) has been an indispensable source of drugs for curing various human diseases. However, the inherent chemical diversity and complexity of TCM restricted the safety and efficacy of its usage. Over the past few decades, the combination of liquid chromatography with mass spectrometry has contributed greatly to the TCM qualitative analysis. And novel approaches have been continuously introduced to improve the analytical performance, including both the data acquisition methods to generate a large and informative dataset, and the data post-processing tools to extract the structure-related MS information. Furthermore, the fast-developing computer techniques and big data analytics have markedly enriched the data processing tools, bringing benefits of high efficiency and accuracy. To provide an up-to-date review of the latest techniques on the TCM qualitative analysis, multiple data-independent acquisition methods and data-dependent acquisition methods (precursor ion list, dynamic exclusion, mass tag, precursor ion scan, neutral loss scan, and multiple reaction monitoring) and post-processing techniques (mass defect filtering, diagnostic ion filtering, neutral loss filtering, mass spectral trees similarity filter, molecular networking, statistical analysis, database matching, etc.) were summarized and categorized. Applications of each technique and integrated analytical strategies were highlighted, discussion and future perspectives were proposed as well.
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Objective To explore the overall change of chemical components of Bupleuri Radix-Paeoniae Radix Alba herb pair before and after compatibility. Methods The change of chemical constituents of Bupleuri Radix and Paeoniae Radix Alba before and after compatibility were analyzed based on UPLC-MS background subtraction and metabonomics. Chemical constituents of eight batches in Bupleuri Radix, Paeoniae Radix Alba, and Bupleuri Radix-Paeoniae Radix Alba were analyzed by UPLC-MS. Mass spectrometry data of the extracts of Paeoniae Radix Alba and Bupleuri Radix were respectively subtracted from mass spectrum data of the extracts of Bupleuri Radix-Paeoniae Radix Alba herb pair by mass spectrometry background subtraction method, finally mass spectrum data of chemical constituents of Bupleuri Radix and Paeoniae Radix Alba after compatibility were obtained. The chemical components of Bupleuri Radix, Paeoniae Radix Alba before and after compatibility were analyzed by PCA and OPLS-DA separately. Results A total of 57 constituents of Bupleuri Radix-Paeoniae Radix Alba herb pair, Bupleuri Radix, and Paeoniae Radix Alba were detected by UPLC-MS, and 32 of them were identified by the literature. Multivariate statistics showed that there were six ingredients which had significant changes in Bupleuri Radix before and after compatibility and three of them were identified. There were three components which were significantly changed in Paeoniae Radix Alba and two of them were identified. The saikosaponin a, 3’-O-acetylation of saikosaponin a, and 4’’-O-acetylation of saikosaponin A decreased after compatibility in Bupleuri Radix, and paeoniflorin, gallic acidpaeoniflorin or their isomers increased after compatibility in Paeoniae Radix Alba. Conclusion The overall differences of chemical composition in Bupleuri Radix-Paeoniae Radix Alba before and after compatibility were compared, which laid the foundation for the explanation of its compatibility mechanism.
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BACKGROUND: Quantitative myocardial perfusion scintigraphy with thallium-201 has provided an increase in accuracy of coronary artery disease detection. Myocardial uptake and clearance data based on thallium-201 kinetics in normal subjects is using in quantitative interpretation of myocardial perfusion scan. Exercise and pharmacologic stress make different hemodynamic effects and different myocardial uptake and clearance of thallium-201. Effect of background subtraction on thallium-201 myocardial perfusion scintigraphy may also be different due to different thallium-201 biokinetics in each type of stress used. This study was aimed to evaluate the effects of the background subtraction on myocardial thallium-201 biokinetics according to the type of stress used. METHODS: Fifteen healthy volunteers underwent planar thallium-201 myocardial perfusion imaging with peak treadmill exercise and intravenous infusion of dipyridamole, adenosine, or dobutamine. Each subject underwent another planar thallium-201 myocardial perfusion imaging at 4 hour later, as a redistribution imaging. Count densities from ROIs(regions of interest) drawn over left ventricle, lung, and liver were compared between before- and after background subtraction. RESULTS: Before background subtraction, absolute myocardial thallium-201 uptake was greater after pharmacologic testing than exercise testing in both stress and redistribution imaging. Myocardial thallium-201 clearance was lower during pharmacologic stress than exercise. After background subtraction, myocardial thallium-201 uptake was higher during exercise than pharmacologic testing. The percentage change in clearance was higher with exercise testing, while the percentage change in uptake was higher with pharmacologic testing. CONCLUSION: Thallium-201 uptake and clearance in heart and adjacent structure were different between adenosine, dipyridamole, dobutamine, and exercise testing. Background subtraction results in different myocardial uptake and clearance data due to different extracardiac uptake subtracted in each stress method. The diagnostic criteria for quantitative analysis of myocardial perfusion imaging must be specified for types of myocardial stress and processes used for background subtraction.