目的通过体素水平静息态功能MRI(resting state functional MRI,rs-fMRI)序列探索脑小血管病相关轻度认知障碍(mild cognitive impairment associated with cerebral small vessel disease,CSVD-MCI)患者早期认知障碍的机制,并分析其与...目的通过体素水平静息态功能MRI(resting state functional MRI,rs-fMRI)序列探索脑小血管病相关轻度认知障碍(mild cognitive impairment associated with cerebral small vessel disease,CSVD-MCI)患者早期认知障碍的机制,并分析其与临床神经心理学指标的相关性。材料与方法筛选临床及常规MRI检查符合CSVD-MCI诊断标准的受试者21例,并挑选与其年龄、性别及受教育年限相匹配的健康对照(health control,HC)20例,所有被试都接受rs-fMRI检查,计算全脑度中心度(degree centrality,DC)值,将两组DC值差异显著团块的峰值蒙特利尔神经病学研究所(Montreal Neurological Institute,MNI)坐标作为种子点,与全脑其他体素进行功能连接(functional connection,FC)分析,两组脑功能存在差异脑区的DC及FC值与蒙特利尔认知评估量表(Montreal Cognitive Assessment,MoCA)评分进行相关性分析,并进一步分析CSVD总负荷评分与MoCA评分,以及CSVD总负荷评分与各认知域评分的相关性。结果与HC组相比,CSVD-MCI组左侧内侧额上回/左侧前扣带回、左侧角回/左侧缘上回、右侧内侧额上回/右侧额中回、左侧小脑及右侧小脑DC值减低,左侧前扣带回与左侧颞中下回、双侧楔前叶、双侧中扣带回FC值减低。白质高信号评分、CSVD总负荷评分与MoCA评分呈显著负相关(r_(s)=−0.461,P=0.036;r_(s)=−0.458,P=0.037);CSVD总负荷评分与视空间和执行功能评分呈负相关(r_(s)=−0.473,P=0.030),与其他认知域评分无显著相关性。CSVD-MCI组左侧前扣带回-右侧楔前叶FC值与MoCA评分呈显著正相关(r=0.565,P=0.018)。结论常规MRI可以显示CSVD特征性影像学病灶,rs-fMRI序列可以早期发现DC及FC减低脑区,CSVD评分及DC、FC值与临床神经心理学评分呈明显相关,可作为CSVD-MCI患者的潜在影像学标志物,揭示其认知功能减退的潜在机制。展开更多
Vanadium dioxide thin films were fabricated through annealing vanadium oxide thin films deposited by dual ion beam sputtering. X-ray diffraction (XRD), atom force microscopy (AFM), and Fourier transform infrared spect...Vanadium dioxide thin films were fabricated through annealing vanadium oxide thin films deposited by dual ion beam sputtering. X-ray diffraction (XRD), atom force microscopy (AFM), and Fourier transform infrared spectrum (FTIR) were employed to measure the crystalline structure, surface morphology, and infrared optical transmittance. The phase transition properties were characterized by transmittance. The results show that the annealed vanadium oxide thin film is composed of monoclinic VO2, with preferred orientation of (011). The maximum of transmittance change is beyond 65% as the temperature increases from 20 to 80 C. The reversible changes in optical transmittance against temperature were observed. The change rate of transmittance at short wavelength is higher than that at long wavelength at the same temperature across semiconductor-metal phase transition. This phenomenon was discussed using diffraction effect.展开更多
基金supported by the National High-Tech Research and Development Program of China(No.2008AA031401)the National Natural Science Foundation of China (No.60771019)+2 种基金the Natural Science Foundation of Tianjin, China (No.08JCZD-JC17500)the StateKey Lab on Integrated Optoelectronics (No.2010KFB001)The Research Fund for the Doctoral Program of Higher Education of China (No.20100032120029)
文摘Vanadium dioxide thin films were fabricated through annealing vanadium oxide thin films deposited by dual ion beam sputtering. X-ray diffraction (XRD), atom force microscopy (AFM), and Fourier transform infrared spectrum (FTIR) were employed to measure the crystalline structure, surface morphology, and infrared optical transmittance. The phase transition properties were characterized by transmittance. The results show that the annealed vanadium oxide thin film is composed of monoclinic VO2, with preferred orientation of (011). The maximum of transmittance change is beyond 65% as the temperature increases from 20 to 80 C. The reversible changes in optical transmittance against temperature were observed. The change rate of transmittance at short wavelength is higher than that at long wavelength at the same temperature across semiconductor-metal phase transition. This phenomenon was discussed using diffraction effect.
