Aging effects on cerebral asymmetry: a voxel-based morphometry and diffusion tensor imaging study

The hemispheres of the human brain are functionally and structurally asymmetric. The purpose of this study was to evaluate the effects of aging on gray and white matter asymmetry. Two hundred twenty-six right-handed normal volunteers aged 21–71 years were included in this study. The effects of aging on gray matter volume asymmetry and white matter fractional anisotropy asymmetry were evaluated with use of voxel-based morphometry and voxel-based analysis of fractional anisotropy maps derived from diffusion tensor imaging (DTI), respectively. The voxel-based morphometry showed no significant correlation between age and gray matter volume asymmetry. The voxel-based analysis of DTI also showed no significant correlation between age and white matter fractional anisotropy asymmetry. Our results showed no significant effects of aging on either gray matter volume asymmetry or white matter fractional anisotropy asymmetry.     

铜离子交换分子筛上NO吸附的IR光谱及TPD研究

采用原位IR光谱及TPD技术研究了NO在铜离子交换分子筛上各种表面物种的生成及脱附,并与NO在Cu-ZSM-5上的分解反应性能相关联,考察了Cu-ZSM-5反应活性高的原因及O₂的生成机理。NO的吸附状态随分子筛母体种类及铜离子交换度的不同而变化,交换度较高的ZSM-5催化剂上容易形成NO-3物种,该物种对NO分解及O₂的生成具有重要作用。     

Potential switching of optical properties in polymer electrolytes

The electric field dependence of the optical properties of a series of anion-conducting polymer electrolytes at an ITO–electrolyte interface was investigated. A change in reflectance and refractive index of polymer electrolytes [poly(ethyl methacrylate)]₁₈(Bu₃SnX)₃Bu₄NX where X = Cl, Br, and SCN was observed. This was ascribed to anion accumulation/depletion in the interfacial region. Shorter response times were observed for electrolytes with higher conductivities, illustrating the interrelationship between these two phenomena. © 1997 John Wiley & Sons, Inc. J Polym Sci B: Polym Phys 35: 2057–2062, 1997