To investigate the effects of long-term low dose hormone replacement therapy （HRT） on postmenopaosal women in homone level, cognition score, hippocampus volume, and magnetic resonance spectroscopy （MRS） parameters...To investigate the effects of long-term low dose hormone replacement therapy （HRT） on postmenopaosal women in homone level, cognition score, hippocampus volume, and magnetic resonance spectroscopy （MRS） parameters. Methods A total of 182 postmenopausal women aged 50-87 years were chosen at Peking Union Medical College Hospital and assigned to HRT group and control group. The volunteers of HRT group had taken low dose hormone [ estradiol （E2 ） 0. 5-1.0 mg and progesterone 0.5-2.0 mg, once a day ] for 4-33 years. The concentrations of E2, progesterone, and testosterone were measured using enzyme-linked immunosorbent assay （ELISA）. The gene types of apolipoprotein E （ApoE） were measured by polymerase chain reaction, and the subjects with susceptible genes （ ApoE ε3/ε4） of Alzheimer＇s disease （AD） were screened. Their hippocampus volumes and MRS parameters were obtained through magnetic resonance imaging （MRI）, and results in two groups were analyzed by statistical method. Results Compared with control group, the concentrations of E2 at each age stage in HRT group were significantly higher （P 〈0. 05） except the 80-89 years old subgroup; yet, there were no statistical differences in the concentrations of progesterone and testosterone between the two groups. There was no obvious difference in ApoE subtypes distribution between the two groups The results of hippocampus MRI for the subjects with susceptible genes ApoE ε3/ε4 （HRT group 14 cases, control group 11 cases） showed that the ratio of bilateral hippocampus volume to whole brain volume in HRT group （0. 406 ± 0.028） was signiticantlyhigher than control gronp （0.369±0.031, P〈0.05）. Theresults of ^1H MRS for the subjects with susceptible genes ApoE ε3/ε4 （ HRT group 12 cases, control group 11 cases） showed that the N-acetylaspartate/total creatine at the area of hippocampus in HRT group （ 1.54±0. 08 ） were significantly higher than control group （ 1.45±0. 13, P 〈 0. 05）. Conclusions For postmenopausal women, long-term low dose HRT can maintain the physiological concentration of E2 in plasma. Furthermore, the hippocampus MRI performed on those with ApoE ε3/ε3 genes shows that long-term low dose HRT can prevent hippocampus atrophy, which is beneficial to maintain the brain function and prevent AD.展开更多
硅橡胶复合绝缘子在电力系统中使用广泛,但随着运行时间增长容易老化,威胁电力系统的安全运行。为此,采用核磁共振(nuclear magnetic resonance,NMR)技术来分析识别硅橡胶复合绝缘子的老化状态。运用NMR分析方法从低场NMR信号中提取出...硅橡胶复合绝缘子在电力系统中使用广泛,但随着运行时间增长容易老化,威胁电力系统的安全运行。为此,采用核磁共振(nuclear magnetic resonance,NMR)技术来分析识别硅橡胶复合绝缘子的老化状态。运用NMR分析方法从低场NMR信号中提取出表征硅橡胶绝缘子老化状态的特征量,解释绝缘子的老化机理,并与红外光谱分析技术进行对比分析。结果表明:复合绝缘子NMR测量结果与红外光谱外层吸收峰吻合,2种结果在一定程度上都能反映复合绝缘子的老化程度;绝缘子的老化程度越高,NMR方法的横向弛豫时间值越小,红外光谱的吸收值越低。展开更多
目的探讨氢质子磁共振波谱(1H-MRS)对病毒性脑炎和脑低级别胶质瘤的鉴别诊断价值。方法使用飞利浦3.0 T MR系统对低级别胶质瘤(胶质瘤组)20例,病毒性脑炎(脑炎组)25例进行常规MRI平扫和增强扫描,所有病例均在病灶区及相应正常脑实质区...目的探讨氢质子磁共振波谱(1H-MRS)对病毒性脑炎和脑低级别胶质瘤的鉴别诊断价值。方法使用飞利浦3.0 T MR系统对低级别胶质瘤(胶质瘤组)20例,病毒性脑炎(脑炎组)25例进行常规MRI平扫和增强扫描,所有病例均在病灶区及相应正常脑实质区设置感兴趣区进行1H-MRS成像。利用Function Tool软件对波谱数据进行分析,分别检测病灶侧和对侧相应正常脑区MRS的N-乙酰天门冬氨酸(NAA)、肌酸(Cr)、胆碱(Cho)值,并进行比较。结果两组正常侧与相应部位病灶侧的Cho/Cr、Cho/NAA、NAA/Cho、NAA/Cr比较差异有统计学意义(均P<0.01)。两组间病灶侧Cho/Cr、Cho/NAA、NAA/Cho比较差异有统计学意义(均P<0.01)。两组间正常侧Cho/Cr、Cho/NAA、NAA/Cho、NAA/Cr比较差异无统计学意义(均P>0.05)。Cho/Cr的ROC曲线下面积为0.926,其中Cho/Cr取界值为2.46时,鉴别脑低级别胶质瘤与病毒性脑炎的灵敏度为91.7%,特异度为88.9%。结论1H-MRS对病毒性脑炎和脑低级别胶质瘤的鉴别诊断有重要临床价值,其中以Cho/Cr比值鉴别二者的参考价值最大。展开更多
目的探讨氢质子磁共振波谱分析(1H-MRS)在碘异常引起脑损伤病变中的应用价值。方法收集临床诊断碘异常引起脑损伤的病例28例,其中低碘组16例,高碘组12例。使用西门子1.5 T MRI,多体素相位矩阵扫描。检测低碘组和高碘组病人海马区与正常...目的探讨氢质子磁共振波谱分析(1H-MRS)在碘异常引起脑损伤病变中的应用价值。方法收集临床诊断碘异常引起脑损伤的病例28例,其中低碘组16例,高碘组12例。使用西门子1.5 T MRI,多体素相位矩阵扫描。检测低碘组和高碘组病人海马区与正常参照区域的代谢物浓度,利用SPSS12.0分析各种代谢物的变化。结果1H-MRS示低碘组胆碱降低、γ-氨基丁酸、N-乙酰天门冬氨酸减少;高碘组胆碱增加、谷氨酸升高,γ-氨基丁酸、N-乙酰天门冬氨酸减少。结论1H-MRS在碘异常引起脑损伤病变定性诊断中有重要的临床价值。展开更多
文摘To investigate the effects of long-term low dose hormone replacement therapy （HRT） on postmenopaosal women in homone level, cognition score, hippocampus volume, and magnetic resonance spectroscopy （MRS） parameters. Methods A total of 182 postmenopausal women aged 50-87 years were chosen at Peking Union Medical College Hospital and assigned to HRT group and control group. The volunteers of HRT group had taken low dose hormone [ estradiol （E2 ） 0. 5-1.0 mg and progesterone 0.5-2.0 mg, once a day ] for 4-33 years. The concentrations of E2, progesterone, and testosterone were measured using enzyme-linked immunosorbent assay （ELISA）. The gene types of apolipoprotein E （ApoE） were measured by polymerase chain reaction, and the subjects with susceptible genes （ ApoE ε3/ε4） of Alzheimer＇s disease （AD） were screened. Their hippocampus volumes and MRS parameters were obtained through magnetic resonance imaging （MRI）, and results in two groups were analyzed by statistical method. Results Compared with control group, the concentrations of E2 at each age stage in HRT group were significantly higher （P 〈0. 05） except the 80-89 years old subgroup; yet, there were no statistical differences in the concentrations of progesterone and testosterone between the two groups. There was no obvious difference in ApoE subtypes distribution between the two groups The results of hippocampus MRI for the subjects with susceptible genes ApoE ε3/ε4 （HRT group 14 cases, control group 11 cases） showed that the ratio of bilateral hippocampus volume to whole brain volume in HRT group （0. 406 ± 0.028） was signiticantlyhigher than control gronp （0.369±0.031, P〈0.05）. Theresults of ^1H MRS for the subjects with susceptible genes ApoE ε3/ε4 （ HRT group 12 cases, control group 11 cases） showed that the N-acetylaspartate/total creatine at the area of hippocampus in HRT group （ 1.54±0. 08 ） were significantly higher than control group （ 1.45±0. 13, P 〈 0. 05）. Conclusions For postmenopausal women, long-term low dose HRT can maintain the physiological concentration of E2 in plasma. Furthermore, the hippocampus MRI performed on those with ApoE ε3/ε3 genes shows that long-term low dose HRT can prevent hippocampus atrophy, which is beneficial to maintain the brain function and prevent AD.
文摘硅橡胶复合绝缘子在电力系统中使用广泛,但随着运行时间增长容易老化,威胁电力系统的安全运行。为此,采用核磁共振(nuclear magnetic resonance,NMR)技术来分析识别硅橡胶复合绝缘子的老化状态。运用NMR分析方法从低场NMR信号中提取出表征硅橡胶绝缘子老化状态的特征量,解释绝缘子的老化机理,并与红外光谱分析技术进行对比分析。结果表明:复合绝缘子NMR测量结果与红外光谱外层吸收峰吻合,2种结果在一定程度上都能反映复合绝缘子的老化程度;绝缘子的老化程度越高,NMR方法的横向弛豫时间值越小,红外光谱的吸收值越低。
文摘目的探讨氢质子磁共振波谱(1H-MRS)对病毒性脑炎和脑低级别胶质瘤的鉴别诊断价值。方法使用飞利浦3.0 T MR系统对低级别胶质瘤(胶质瘤组)20例,病毒性脑炎(脑炎组)25例进行常规MRI平扫和增强扫描,所有病例均在病灶区及相应正常脑实质区设置感兴趣区进行1H-MRS成像。利用Function Tool软件对波谱数据进行分析,分别检测病灶侧和对侧相应正常脑区MRS的N-乙酰天门冬氨酸(NAA)、肌酸(Cr)、胆碱(Cho)值,并进行比较。结果两组正常侧与相应部位病灶侧的Cho/Cr、Cho/NAA、NAA/Cho、NAA/Cr比较差异有统计学意义(均P<0.01)。两组间病灶侧Cho/Cr、Cho/NAA、NAA/Cho比较差异有统计学意义(均P<0.01)。两组间正常侧Cho/Cr、Cho/NAA、NAA/Cho、NAA/Cr比较差异无统计学意义(均P>0.05)。Cho/Cr的ROC曲线下面积为0.926,其中Cho/Cr取界值为2.46时,鉴别脑低级别胶质瘤与病毒性脑炎的灵敏度为91.7%,特异度为88.9%。结论1H-MRS对病毒性脑炎和脑低级别胶质瘤的鉴别诊断有重要临床价值,其中以Cho/Cr比值鉴别二者的参考价值最大。
文摘目的探讨氢质子磁共振波谱分析(1H-MRS)在碘异常引起脑损伤病变中的应用价值。方法收集临床诊断碘异常引起脑损伤的病例28例,其中低碘组16例,高碘组12例。使用西门子1.5 T MRI,多体素相位矩阵扫描。检测低碘组和高碘组病人海马区与正常参照区域的代谢物浓度,利用SPSS12.0分析各种代谢物的变化。结果1H-MRS示低碘组胆碱降低、γ-氨基丁酸、N-乙酰天门冬氨酸减少;高碘组胆碱增加、谷氨酸升高,γ-氨基丁酸、N-乙酰天门冬氨酸减少。结论1H-MRS在碘异常引起脑损伤病变定性诊断中有重要的临床价值。
