利用1 H NMR法测定27个不同生长期的当归提取物,对当归的主要活性成分阿魏酸、藁本内酯、当归多糖进行了初步归属,用特征峰相对峰面积表示3种活性成分的相对含量,并对它们在生长过程中的含量变化进行分析.数据分析显示,当归中阿魏酸、...利用1 H NMR法测定27个不同生长期的当归提取物,对当归的主要活性成分阿魏酸、藁本内酯、当归多糖进行了初步归属,用特征峰相对峰面积表示3种活性成分的相对含量,并对它们在生长过程中的含量变化进行分析.数据分析显示,当归中阿魏酸、藁本内酯、当归多糖的含量在第1年变化较为平稳,第2年和第3年变化相对较为活跃,而在当归的生长周期内,当归多糖的含量变化明显大于其他两种活性成分,为参与代谢活动的主要活性成分.结果证实,通过对照1 H NMR指纹图谱,将相对含量法与主成分分析法相结合,能对不同生长期的当归药材中的活性成分进行宏观评价和分析,可作为植物药材代谢组学的研究方法.展开更多
Background Recent studies suggest that bone marrow adipose tissue might play a role in the pathogenesis of osteoporosis. There are inconsistent findings on the relationship among marrow fat content, bone mineral densi...Background Recent studies suggest that bone marrow adipose tissue might play a role in the pathogenesis of osteoporosis. There are inconsistent findings on the relationship among marrow fat content, bone mineral density and apparent diffusion coefficient （ADC）. This study aimed to prospectively explore the efficacy of MR spectroscopy （MRS） and diffusion-weighted MR imaging （DWl） in detecting vertebral marrow changes in postmenopausal women with varying bone densities. Methods Both MRS and DWl of the lumber spine were performed in 102 postmenopausal women （mean age, （67.3±6.5） years; range, 55-83 years）, who underwent dual X-ray absorptiometry. Marrow fat content and ADC were compared and correlated among three groups： 24 with normal bone density, 31 with osteopenia and 47 with osteoporosis. Results Vertebral marrow fat content was significantly increased in the osteoporotic group （（65.60±7.68）%, P 〈0.001） and the osteopenic group （（57.68±6.45）%, P 〈0.001）, when compared with the normal bone density group （（51.67±3.27）%）. ADC values were significantly decreased in the osteoporotic group （（0.39±0.03）×10^-3mm^2/s, P 〈0.001） and in the osteopenic group （（0.42±0.02）×10^-3mm^2/s, P 〈0.001）, when compared with the normal bone density group （（0.47±0.03）×10^-3mm^2/s）. The marrow fat content negatively correlated with both bone density （r=-0.731, P 〈0.001） and marrow ADC （r=-0.572, P 〈0.001）. The bone density positively correlated with the ADC values （r=0.802, P 〈0.001）. Conclusions Postmenopausal women experience a corresponding increase in vertebral marrow fat content as the bone density decreases. Marrow fat content and ADC correlate to the bone density. MRS and DWl may indirectly assess the early bone marrow changes in postmenopausal women.展开更多
以壳聚糖为载体,以硝酸铈铵作引发剂,用甲基丙烯酰氧乙基-十六烷基-二甲基溴化铵为活性单体进行接枝共聚反应制备季铵盐型壳聚糖衍生物.用核磁共振和红外光谱对接枝产物进行了表征和测定,用悬菌定量实验研究了其抗菌性能.结果表明:甲基...以壳聚糖为载体,以硝酸铈铵作引发剂,用甲基丙烯酰氧乙基-十六烷基-二甲基溴化铵为活性单体进行接枝共聚反应制备季铵盐型壳聚糖衍生物.用核磁共振和红外光谱对接枝产物进行了表征和测定,用悬菌定量实验研究了其抗菌性能.结果表明:甲基丙烯酰氧乙基-十六烷基-二甲基溴化铵通过其双键可以接枝到壳聚糖表面;所制备的壳聚糖季铵盐衍生物对大肠杆菌、金黄色葡萄球菌以及白色念珠菌在振荡作用15 m in后,平均杀菌率分别为99.99%、99.99%和99.96%.展开更多
应用生物核磁共振技术结合主成分分析(PCA)和正交偏最小二乘判别分析法(OPLS-DA)分别分析奶牛在患有临床酮病和亚临床酮病时内源性代谢产物的变化,研究酮病对奶牛代谢过程的影响,寻找差异表达的代谢物。运用1 H核磁共振(1 H NMR)技术获...应用生物核磁共振技术结合主成分分析(PCA)和正交偏最小二乘判别分析法(OPLS-DA)分别分析奶牛在患有临床酮病和亚临床酮病时内源性代谢产物的变化,研究酮病对奶牛代谢过程的影响,寻找差异表达的代谢物。运用1 H核磁共振(1 H NMR)技术获得临床酮病组、亚临床酮病组与健康对照组3组奶牛血浆代谢组谱。所采集的数据经过模式分析获得差异代谢物。结果显示:临床酮病组、亚临床酮病组与健康对照组相比,差异性代谢物均为23个,其中临床酮病组6个表达上调,17个表达下调;而亚临床酮病组13个表达上调,10个表达下调。临床酮病组与亚临床酮病组相比,差异性代谢物为28个,其中4个表达上调,24个表达下调。结果表明1 H NMR谱结合模式识别分析技术能有效获得区别奶牛临床酮病和亚临床酮病的差异代谢物,并全景式地揭示了酮病发生过程中机体发生的广泛代谢紊乱,为今后深入探究酮病发生机理和新的防治策略奠定了基础。展开更多
以吡嗪作为内标物,采用1 H NMR方法对葛根素的含量进行测定。对葛根素的1 H NMR谱进行分析,考察了脉冲宽度、延迟时间、扫描次数等对测定结果的影响,确定了特征峰峰面积截取范围,根据峰面积积分值计算样品含量。葛根素定量分析最佳参数...以吡嗪作为内标物,采用1 H NMR方法对葛根素的含量进行测定。对葛根素的1 H NMR谱进行分析,考察了脉冲宽度、延迟时间、扫描次数等对测定结果的影响,确定了特征峰峰面积截取范围,根据峰面积积分值计算样品含量。葛根素定量分析最佳参数为:室温,匀场3次,脉冲宽度18μs,延迟时间1.5μs,扫描次数48。计算含量的特征峰选择为C7-H或C4-H峰。展开更多
The relative chemical shifts (△δ) △δwere put forward to investigate the microscopic structure of 1-ethyl-3-methyl-imidazolium tetrafluoroborate (EmimBF4) during the dilution process with water.The concentration-de...The relative chemical shifts (△δ) △δwere put forward to investigate the microscopic structure of 1-ethyl-3-methyl-imidazolium tetrafluoroborate (EmimBF4) during the dilution process with water.The concentration-dependent △δ(C2)H-(C4)H,△δ(C2)H-(C5)H and △δ(C4)H-(C5)H were analyzed.The results reveal that the variations of the microscopic structures of three aromatic protons are inconsistent.The strength of the H-bond between water and three aromatic protons follows the order:(C2)H···O 】 (C4)H···O 】 (C5)H···O.The concentration-dependent △δ(C6)H-(C7)H and △δ(C6)H-(C8)H indicate the formation of the H-bonds of (Calkyl)H···O is impossible,and more water is located around (C6)H than around (C7)H or (C8)H.The concentration-dependent △δ(C2)H-(C4)H and △δ(C2)H-(C5)H both increase rapidly when xwater 】 0.9 or so,suggesting the ionic pairs of EmimBF4 are dissociated rapidly.The turning points of concentration-dependent △δ(C2)H-(C4)H and △δ(C2)H-(C5)H indicate that some physical properties of the EmimBF4/water mixtures also change at the corresponding concentration point.The microscopic structures of EmimBF4 in water could be clearly detected by the relative chemical shifts.展开更多
文摘利用1 H NMR法测定27个不同生长期的当归提取物,对当归的主要活性成分阿魏酸、藁本内酯、当归多糖进行了初步归属,用特征峰相对峰面积表示3种活性成分的相对含量,并对它们在生长过程中的含量变化进行分析.数据分析显示,当归中阿魏酸、藁本内酯、当归多糖的含量在第1年变化较为平稳,第2年和第3年变化相对较为活跃,而在当归的生长周期内,当归多糖的含量变化明显大于其他两种活性成分,为参与代谢活动的主要活性成分.结果证实,通过对照1 H NMR指纹图谱,将相对含量法与主成分分析法相结合,能对不同生长期的当归药材中的活性成分进行宏观评价和分析,可作为植物药材代谢组学的研究方法.
文摘Background Recent studies suggest that bone marrow adipose tissue might play a role in the pathogenesis of osteoporosis. There are inconsistent findings on the relationship among marrow fat content, bone mineral density and apparent diffusion coefficient （ADC）. This study aimed to prospectively explore the efficacy of MR spectroscopy （MRS） and diffusion-weighted MR imaging （DWl） in detecting vertebral marrow changes in postmenopausal women with varying bone densities. Methods Both MRS and DWl of the lumber spine were performed in 102 postmenopausal women （mean age, （67.3±6.5） years; range, 55-83 years）, who underwent dual X-ray absorptiometry. Marrow fat content and ADC were compared and correlated among three groups： 24 with normal bone density, 31 with osteopenia and 47 with osteoporosis. Results Vertebral marrow fat content was significantly increased in the osteoporotic group （（65.60±7.68）%, P 〈0.001） and the osteopenic group （（57.68±6.45）%, P 〈0.001）, when compared with the normal bone density group （（51.67±3.27）%）. ADC values were significantly decreased in the osteoporotic group （（0.39±0.03）×10^-3mm^2/s, P 〈0.001） and in the osteopenic group （（0.42±0.02）×10^-3mm^2/s, P 〈0.001）, when compared with the normal bone density group （（0.47±0.03）×10^-3mm^2/s）. The marrow fat content negatively correlated with both bone density （r=-0.731, P 〈0.001） and marrow ADC （r=-0.572, P 〈0.001）. The bone density positively correlated with the ADC values （r=0.802, P 〈0.001）. Conclusions Postmenopausal women experience a corresponding increase in vertebral marrow fat content as the bone density decreases. Marrow fat content and ADC correlate to the bone density. MRS and DWl may indirectly assess the early bone marrow changes in postmenopausal women.
文摘以壳聚糖为载体,以硝酸铈铵作引发剂,用甲基丙烯酰氧乙基-十六烷基-二甲基溴化铵为活性单体进行接枝共聚反应制备季铵盐型壳聚糖衍生物.用核磁共振和红外光谱对接枝产物进行了表征和测定,用悬菌定量实验研究了其抗菌性能.结果表明:甲基丙烯酰氧乙基-十六烷基-二甲基溴化铵通过其双键可以接枝到壳聚糖表面;所制备的壳聚糖季铵盐衍生物对大肠杆菌、金黄色葡萄球菌以及白色念珠菌在振荡作用15 m in后,平均杀菌率分别为99.99%、99.99%和99.96%.
文摘应用生物核磁共振技术结合主成分分析(PCA)和正交偏最小二乘判别分析法(OPLS-DA)分别分析奶牛在患有临床酮病和亚临床酮病时内源性代谢产物的变化,研究酮病对奶牛代谢过程的影响,寻找差异表达的代谢物。运用1 H核磁共振(1 H NMR)技术获得临床酮病组、亚临床酮病组与健康对照组3组奶牛血浆代谢组谱。所采集的数据经过模式分析获得差异代谢物。结果显示:临床酮病组、亚临床酮病组与健康对照组相比,差异性代谢物均为23个,其中临床酮病组6个表达上调,17个表达下调;而亚临床酮病组13个表达上调,10个表达下调。临床酮病组与亚临床酮病组相比,差异性代谢物为28个,其中4个表达上调,24个表达下调。结果表明1 H NMR谱结合模式识别分析技术能有效获得区别奶牛临床酮病和亚临床酮病的差异代谢物,并全景式地揭示了酮病发生过程中机体发生的广泛代谢紊乱,为今后深入探究酮病发生机理和新的防治策略奠定了基础。
文摘以吡嗪作为内标物,采用1 H NMR方法对葛根素的含量进行测定。对葛根素的1 H NMR谱进行分析,考察了脉冲宽度、延迟时间、扫描次数等对测定结果的影响,确定了特征峰峰面积截取范围,根据峰面积积分值计算样品含量。葛根素定量分析最佳参数为:室温,匀场3次,脉冲宽度18μs,延迟时间1.5μs,扫描次数48。计算含量的特征峰选择为C7-H或C4-H峰。
基金the National Natural Science Foundation of China (20773109 & 20704035)the Natural Science Foundation of Zhejiang Province (Y4090453)
文摘The relative chemical shifts (△δ) △δwere put forward to investigate the microscopic structure of 1-ethyl-3-methyl-imidazolium tetrafluoroborate (EmimBF4) during the dilution process with water.The concentration-dependent △δ(C2)H-(C4)H,△δ(C2)H-(C5)H and △δ(C4)H-(C5)H were analyzed.The results reveal that the variations of the microscopic structures of three aromatic protons are inconsistent.The strength of the H-bond between water and three aromatic protons follows the order:(C2)H···O 】 (C4)H···O 】 (C5)H···O.The concentration-dependent △δ(C6)H-(C7)H and △δ(C6)H-(C8)H indicate the formation of the H-bonds of (Calkyl)H···O is impossible,and more water is located around (C6)H than around (C7)H or (C8)H.The concentration-dependent △δ(C2)H-(C4)H and △δ(C2)H-(C5)H both increase rapidly when xwater 】 0.9 or so,suggesting the ionic pairs of EmimBF4 are dissociated rapidly.The turning points of concentration-dependent △δ(C2)H-(C4)H and △δ(C2)H-(C5)H indicate that some physical properties of the EmimBF4/water mixtures also change at the corresponding concentration point.The microscopic structures of EmimBF4 in water could be clearly detected by the relative chemical shifts.
