The segregation of bismuth atoms on the [101] tilt copper grain boundaries Σ3 (111) 70.53°, Σ33 (545) 58.99°, Σ11(323) 50.48° and Σ9 (212) 38.94° has been studied by pseudo-molecular dynamics u...The segregation of bismuth atoms on the [101] tilt copper grain boundaries Σ3 (111) 70.53°, Σ33 (545) 58.99°, Σ11(323) 50.48° and Σ9 (212) 38.94° has been studied by pseudo-molecular dynamics using the empirical N-body potentials. The relationship between bismuth segregation and grain boundary structure has been discussed in detail.展开更多
During the analysis of benziamidazole-class irreversible proton pump inhibitors,an unusual mass spectral response with the mass-to-charge ratio at[Mt10]t intrigued us,as it couldn't be assigned to any literature k...During the analysis of benziamidazole-class irreversible proton pump inhibitors,an unusual mass spectral response with the mass-to-charge ratio at[Mt10]t intrigued us,as it couldn't be assigned to any literature known relevant structure,intermediate or adduct ion.Moreover,this mysterious mass pattern of[Mt10]t has been gradually observed by series of marketed proton pump inhibitors,viz.omeprazole,pantoprazole,lansoprazole and rabeprazole.All the previous attempts to isolate the corresponding component were unsuccessful.The investigation of present work addresses this kind of signal to a pyridinium thiocyanate mass spectral intermediate(10),which is the common fragment ion of series of labile aggregates.The origin of such aggregates can be traced to the reactive intermediates formed by acid-promoted degradation.These reactive intermediates tend to react with each other and give raise series of complicated aggregates systematically in a water/acetonitrile solution by electrospray ionization.The structure of the corresponding pyridinium thiocyanate species of omeprazole(10a)has been eventually characterized with the help of synthetic specimen(10a′).Our structural proposal as well as its origin was supported by in situ nuclear magnetic resonance,chemical derivatization and colorimetric experiments.展开更多
胶质瘤是最常见的颅内原发恶性肿瘤。氨基质子转移成像(amide proton transfer imaging,APT)是目前一种以磁共振平扫方式反映肿瘤内多肽及蛋白质的氨基质子与水中的氢离子转运水平的技术,可以较为准确地反映肿瘤内的蛋白质水平、pH值等...胶质瘤是最常见的颅内原发恶性肿瘤。氨基质子转移成像(amide proton transfer imaging,APT)是目前一种以磁共振平扫方式反映肿瘤内多肽及蛋白质的氨基质子与水中的氢离子转运水平的技术,可以较为准确地反映肿瘤内的蛋白质水平、pH值等相关信息。在国内外已被广泛应用于胶质瘤的手术前后病情判断研究。本文将国内外该领域的研究进展作一简要综述。展开更多
目的建立丹参水溶性成分HPLC数字化指纹图谱,为丹参质量控制提供依据。方法采用RP-HPLC法分析丹参水溶液,以Century SIL BDS柱(250mm×4.6mm,5μm),流动相为1%醋酸水-1%醋酸甲醇低压梯度洗脱,检测波长:290nm,柱温:(30±0.15)℃...目的建立丹参水溶性成分HPLC数字化指纹图谱,为丹参质量控制提供依据。方法采用RP-HPLC法分析丹参水溶液,以Century SIL BDS柱(250mm×4.6mm,5μm),流动相为1%醋酸水-1%醋酸甲醇低压梯度洗脱,检测波长:290nm,柱温:(30±0.15)℃,进样量5μL。用"中药色谱指纹图谱超信息特征数字化评价系统3.0"软件计算不同批次的丹参水溶性成分HPLC指纹图谱的色谱指纹图谱指数F和色谱指纹图分离量指数RF等46个参数进行潜信息特征数字化评价。以双参照物体系结合定量结构-性质相关(QSPR)原理标定指纹峰的表观分子量、峰位、洗脱动量数δ、折合相对积分ф。结果以丹酚酸B(SAB)峰为参照物峰,确定36个共有峰,建立了丹参水溶性成分HPLC数字化指纹图谱,获得了判别丹参药材质量的重要数字信息。以双定性双定量相似度法评价不同产地丹参药材,质量稳定。结论所建立HPLC数字化指纹图谱具有较好的精密度和重现性,适用于丹参药材的质量控制。数字化指纹图谱是数字中药的核心技术,双定性双定量相似度法是宏观定性定量评价中药质量的最准确、最佳技术。展开更多
基金The subject supported by the Chinese Academy of Sciences and National Natural Science Foundation of China
文摘The segregation of bismuth atoms on the [101] tilt copper grain boundaries Σ3 (111) 70.53°, Σ33 (545) 58.99°, Σ11(323) 50.48° and Σ9 (212) 38.94° has been studied by pseudo-molecular dynamics using the empirical N-body potentials. The relationship between bismuth segregation and grain boundary structure has been discussed in detail.
基金supported by the National Natural Science Foundation of China(Grant Nos.:82030107 and 81872831)the National Science and Technology Major Projects for significant new drugs creation of the 13th five-year plan(Grant Nos.:2017ZX09101001 and 2018ZX09721002007).
文摘During the analysis of benziamidazole-class irreversible proton pump inhibitors,an unusual mass spectral response with the mass-to-charge ratio at[Mt10]t intrigued us,as it couldn't be assigned to any literature known relevant structure,intermediate or adduct ion.Moreover,this mysterious mass pattern of[Mt10]t has been gradually observed by series of marketed proton pump inhibitors,viz.omeprazole,pantoprazole,lansoprazole and rabeprazole.All the previous attempts to isolate the corresponding component were unsuccessful.The investigation of present work addresses this kind of signal to a pyridinium thiocyanate mass spectral intermediate(10),which is the common fragment ion of series of labile aggregates.The origin of such aggregates can be traced to the reactive intermediates formed by acid-promoted degradation.These reactive intermediates tend to react with each other and give raise series of complicated aggregates systematically in a water/acetonitrile solution by electrospray ionization.The structure of the corresponding pyridinium thiocyanate species of omeprazole(10a)has been eventually characterized with the help of synthetic specimen(10a′).Our structural proposal as well as its origin was supported by in situ nuclear magnetic resonance,chemical derivatization and colorimetric experiments.
文摘胶质瘤是最常见的颅内原发恶性肿瘤。氨基质子转移成像(amide proton transfer imaging,APT)是目前一种以磁共振平扫方式反映肿瘤内多肽及蛋白质的氨基质子与水中的氢离子转运水平的技术,可以较为准确地反映肿瘤内的蛋白质水平、pH值等相关信息。在国内外已被广泛应用于胶质瘤的手术前后病情判断研究。本文将国内外该领域的研究进展作一简要综述。
文摘目的建立丹参水溶性成分HPLC数字化指纹图谱,为丹参质量控制提供依据。方法采用RP-HPLC法分析丹参水溶液,以Century SIL BDS柱(250mm×4.6mm,5μm),流动相为1%醋酸水-1%醋酸甲醇低压梯度洗脱,检测波长:290nm,柱温:(30±0.15)℃,进样量5μL。用"中药色谱指纹图谱超信息特征数字化评价系统3.0"软件计算不同批次的丹参水溶性成分HPLC指纹图谱的色谱指纹图谱指数F和色谱指纹图分离量指数RF等46个参数进行潜信息特征数字化评价。以双参照物体系结合定量结构-性质相关(QSPR)原理标定指纹峰的表观分子量、峰位、洗脱动量数δ、折合相对积分ф。结果以丹酚酸B(SAB)峰为参照物峰,确定36个共有峰,建立了丹参水溶性成分HPLC数字化指纹图谱,获得了判别丹参药材质量的重要数字信息。以双定性双定量相似度法评价不同产地丹参药材,质量稳定。结论所建立HPLC数字化指纹图谱具有较好的精密度和重现性,适用于丹参药材的质量控制。数字化指纹图谱是数字中药的核心技术,双定性双定量相似度法是宏观定性定量评价中药质量的最准确、最佳技术。
