目的 探究粮谷全粉及各组分间氢同位素比值的差异以及干燥条件和水分对粮谷中氢同位素比值测定的影响。方法 采用高温裂解/元素分析—稳定同位素比值质谱法(high temperature cracking/elemental analysis-stable isotope ratio mass sp...目的 探究粮谷全粉及各组分间氢同位素比值的差异以及干燥条件和水分对粮谷中氢同位素比值测定的影响。方法 采用高温裂解/元素分析—稳定同位素比值质谱法(high temperature cracking/elemental analysis-stable isotope ratio mass spectrometry, TC/EA-IRMS)测定粮谷全粉(玉米、大米、小麦和高粱)及各组分(淀粉、脱脂部分、脂肪、粗纤维和蛋白质)的δ^(2)H值,分析不同干燥条件对粮谷中δ^(2)H值的影响,探讨可交换氢对淀粉氢同位素比值测定的影响。结果 粮谷籽粒与各组分中的δ^(2)H值存在差异,粮谷在105℃烘干至恒重后除水效果最佳。在最佳干燥条件下被不同标准水样处理后,粮谷和淀粉的δ^(2)H值最大差值分别为12.11‰和18.41‰,这表明可交换氢对淀粉的δ^(2)H值具有显著影响(P<0.001)。结论 糖、脂肪、蛋白质、纤维素在粮谷生长过程中存在同位素分馏,使样品的氢同位素不是均一性分布。有机物中含有可交换氢,会与样品所处环境中的水进行同位素交换,影响准确分析,测定粮谷氢同位素比值时需排除水的干扰。本研究为后续粮谷淀粉中氢同位素比值的测定及粮谷溯源研究提供了有效的参考依据。展开更多
Objective: to investigate whether MR 3D-FSE Cube sequence imaging is superior to traditional 2 D-FSE sequence imaging in the diagnosis of space occupying lesions in saddle area. Methods: From January 2018 to January 2...Objective: to investigate whether MR 3D-FSE Cube sequence imaging is superior to traditional 2 D-FSE sequence imaging in the diagnosis of space occupying lesions in saddle area. Methods: From January 2018 to January 2020, data of 106 patients with space-occupying lesions in saddle area confirmed by surgery and pathology were collected, Routine 2 D-FSE sequence and 3 D-FSE Cube sequence scans were performed in all patients before operation. Analysis of MRI images by two radiologists over 10 years of service, and the two sequences were independently diagnosed, based on surgical and pathological findings, the diagnostic results were statistically analyzed. Results: according to conventional 2 D-FSE sequence images and 3 D-FSE Cube sequence images, the diagnostic accuracy was 70.7%(75/106) and 84.9%(90/106), difference was statistically significant (P<0.05). Conclusion: MR 3D-FSE Cube sequence imaging is superior to traditional 2 D-FSE in the qualitative diagnosis of space occupying lesions in saddle area, it is worth popularizing in clinical application.展开更多
文摘目的 探究粮谷全粉及各组分间氢同位素比值的差异以及干燥条件和水分对粮谷中氢同位素比值测定的影响。方法 采用高温裂解/元素分析—稳定同位素比值质谱法(high temperature cracking/elemental analysis-stable isotope ratio mass spectrometry, TC/EA-IRMS)测定粮谷全粉(玉米、大米、小麦和高粱)及各组分(淀粉、脱脂部分、脂肪、粗纤维和蛋白质)的δ^(2)H值,分析不同干燥条件对粮谷中δ^(2)H值的影响,探讨可交换氢对淀粉氢同位素比值测定的影响。结果 粮谷籽粒与各组分中的δ^(2)H值存在差异,粮谷在105℃烘干至恒重后除水效果最佳。在最佳干燥条件下被不同标准水样处理后,粮谷和淀粉的δ^(2)H值最大差值分别为12.11‰和18.41‰,这表明可交换氢对淀粉的δ^(2)H值具有显著影响(P<0.001)。结论 糖、脂肪、蛋白质、纤维素在粮谷生长过程中存在同位素分馏,使样品的氢同位素不是均一性分布。有机物中含有可交换氢,会与样品所处环境中的水进行同位素交换,影响准确分析,测定粮谷氢同位素比值时需排除水的干扰。本研究为后续粮谷淀粉中氢同位素比值的测定及粮谷溯源研究提供了有效的参考依据。
文摘Objective: to investigate whether MR 3D-FSE Cube sequence imaging is superior to traditional 2 D-FSE sequence imaging in the diagnosis of space occupying lesions in saddle area. Methods: From January 2018 to January 2020, data of 106 patients with space-occupying lesions in saddle area confirmed by surgery and pathology were collected, Routine 2 D-FSE sequence and 3 D-FSE Cube sequence scans were performed in all patients before operation. Analysis of MRI images by two radiologists over 10 years of service, and the two sequences were independently diagnosed, based on surgical and pathological findings, the diagnostic results were statistically analyzed. Results: according to conventional 2 D-FSE sequence images and 3 D-FSE Cube sequence images, the diagnostic accuracy was 70.7%(75/106) and 84.9%(90/106), difference was statistically significant (P<0.05). Conclusion: MR 3D-FSE Cube sequence imaging is superior to traditional 2 D-FSE in the qualitative diagnosis of space occupying lesions in saddle area, it is worth popularizing in clinical application.
