目的利用CT技术不仅能直观观察肺的形态与结构,并且可以定量测定其生理功能情况。文中旨在利用GE256排多层螺旋CT研究不同海拔高度健康志愿者的肺功能参数,并分析其变化规律。方法收集2016年3月至2018年2月青海省人民医院体检科健康男...目的利用CT技术不仅能直观观察肺的形态与结构,并且可以定量测定其生理功能情况。文中旨在利用GE256排多层螺旋CT研究不同海拔高度健康志愿者的肺功能参数,并分析其变化规律。方法收集2016年3月至2018年2月青海省人民医院体检科健康男性志愿者40例。按世居住地海拔高度分为中海拔组(平均海拔约2260 m)和高海拔组(平均海拔约4000 m),每组20例。在深吸气及深呼气末进行胸部扫描,利用GE工作站(AW4.6)肺功能软件分析处理,并采集CT肺功能相关指标数据:深吸气末与深呼气末两肺密度平均值(MLDin、MLDex)、两肺容积、(Vin、Vex)、容积差(Vin-Vex)、容积比(Vin/Vex)。结果中海拔组吸气末平均肺密度与高海拔组比较差异无统计学意义[(-869.80±20.66) HU vs (-865.85±22.57) HU,P=0.567];呼气末平均肺密度差异有统计学意义[(-705.90±25.63) HU vs (-745.50±12.76) HU,P=0.000]。高海拔组Vex高于中海拔组[(2279.59±520.25) mL vs (1566.48±350.97) mL,P<0.05],Vin-Vex、Vin/Vex均小于中海拔组(P<0.05)。结论肺功能CT定量技术可更深层了解高海拔低氧环境下人体肺功能变化的特点,为高原医学诠释低氧环境对人体肺功能适应的机制与变化机理提供了影像学依据。展开更多
The ceramic samples with nominal composition of La_(2/3)Ca_(1/3)Fe_(1-x)Mn_(x)O_(3)(0.01≤x≤0.20)were prepared by solid state reaction method.The effect of Fe doping on the Mn site was measured by the positron annihi...The ceramic samples with nominal composition of La_(2/3)Ca_(1/3)Fe_(1-x)Mn_(x)O_(3)(0.01≤x≤0.20)were prepared by solid state reaction method.The effect of Fe doping on the Mn site was measured by the positron annihilation technique and M'dssbauer spectroscopy.Upon doping,no appreciable structure change and electronic structure change in Mn-O plane were observed in the series of compounds.The M6ssbauer parameters show that the iron probe has stable 3+valance with the high spin state in all samples.Moreover,by examining the shape of the spectra,the tendency can be found that the isomer shift and quadruploe splitting increase with the increasing Fe+3 content.This phenomenon shows the local lattice distortion and the localization of d-electrons with the increasing Fe-doping content.展开更多
文摘目的利用CT技术不仅能直观观察肺的形态与结构,并且可以定量测定其生理功能情况。文中旨在利用GE256排多层螺旋CT研究不同海拔高度健康志愿者的肺功能参数,并分析其变化规律。方法收集2016年3月至2018年2月青海省人民医院体检科健康男性志愿者40例。按世居住地海拔高度分为中海拔组(平均海拔约2260 m)和高海拔组(平均海拔约4000 m),每组20例。在深吸气及深呼气末进行胸部扫描,利用GE工作站(AW4.6)肺功能软件分析处理,并采集CT肺功能相关指标数据:深吸气末与深呼气末两肺密度平均值(MLDin、MLDex)、两肺容积、(Vin、Vex)、容积差(Vin-Vex)、容积比(Vin/Vex)。结果中海拔组吸气末平均肺密度与高海拔组比较差异无统计学意义[(-869.80±20.66) HU vs (-865.85±22.57) HU,P=0.567];呼气末平均肺密度差异有统计学意义[(-705.90±25.63) HU vs (-745.50±12.76) HU,P=0.000]。高海拔组Vex高于中海拔组[(2279.59±520.25) mL vs (1566.48±350.97) mL,P<0.05],Vin-Vex、Vin/Vex均小于中海拔组(P<0.05)。结论肺功能CT定量技术可更深层了解高海拔低氧环境下人体肺功能变化的特点,为高原医学诠释低氧环境对人体肺功能适应的机制与变化机理提供了影像学依据。
基金Supported by the National Natural Science Foundation of China under Grant No.19805010by the Key-project of Chinese Academy of Sciences under contract KJ952-S1-416.
文摘The ceramic samples with nominal composition of La_(2/3)Ca_(1/3)Fe_(1-x)Mn_(x)O_(3)(0.01≤x≤0.20)were prepared by solid state reaction method.The effect of Fe doping on the Mn site was measured by the positron annihilation technique and M'dssbauer spectroscopy.Upon doping,no appreciable structure change and electronic structure change in Mn-O plane were observed in the series of compounds.The M6ssbauer parameters show that the iron probe has stable 3+valance with the high spin state in all samples.Moreover,by examining the shape of the spectra,the tendency can be found that the isomer shift and quadruploe splitting increase with the increasing Fe+3 content.This phenomenon shows the local lattice distortion and the localization of d-electrons with the increasing Fe-doping content.
