Objective: To determine the impact of white matter hyperintensities(WMHs) on p hysical health and cognitive function in 60-64 year old individuals residing in the community. Methods:A subsample of 478 persons aged 60-...Objective: To determine the impact of white matter hyperintensities(WMHs) on p hysical health and cognitive function in 60-64 year old individuals residing in the community. Methods:A subsample of 478 persons aged 60-64 from a larger com munity sample underwent brain magnetic resonance imaging(MRI) scans. WMHs on T2 weighted FLAIR (fluid attenuated inversion recovery) MRI scans were assessed usi ng anautomated procedure. Subjects were assessed for global cognitive function, episodic memory, working memory (digit span),information processing speed (Symbo l Digit Modalities Test;SDMT), fine motor dexterity (Purdue Pegboard), and grip strength, and completed the Physical Component Summary of the Short Form Health Survey (SF-12). Regression analyses were used to examine the effect of WMHs on physical and cognitive function. Results: Deep and periventricular WMHs were pre sent in all subjects, with women having slightly more lesions than men. WMHs wer e significantly associated with poorer reported physical health on the SF-12 sc ale, after adjusting for depression, cognitive function, and brain atrophy. WMHs were also related to lower scores on the Purdue Pegboard test, grip strength, c hoice reaction time, and SDMT, but not on tests of episodic memory, working memo ry, general intellectual function,and global cognitive function. On regression a nalyses, the Purdue Pegboard test and grip strength were related to physicaldisa bility. Conclusion: WMHs are common, albeit mild, in middle adult life. They are associated with physical disability,possibly through reduced speed, fine motor coordination, and muscular strength. They are also related to slowed information processing speed but not other cognitive functions.展开更多
The comparative analysis of the dielectric properties of bismuth-containing pyrochlores with different manifestation of atomic order/disorder was carried out.We examined the dielectric properties(including behavior in...The comparative analysis of the dielectric properties of bismuth-containing pyrochlores with different manifestation of atomic order/disorder was carried out.We examined the dielectric properties(including behavior in electric fields)of two pyrochlore compounds:BZN(presumably a composition close to Bi_(1.5)Zn_(0.5)Nb_(1.5)O_(6.5))ceramics with chemical disorder in both A and B cation sublattices and Bi_(2)Ti_(2)O_(7)single crystal with fully chemical ordered structure.The fundamental differences between the dielectric properties of the BZN ceramics and Bi_(2)Ti_(2)O_(7)single crystal were shown.In particular,in the dielectric relaxation behavior(which cannot be described via Arrhenius law in the Bi_(2)Ti_(2)O_(7))or in the influence of the electric fields on the dielectric permittivity(split-ting of the field-cooled and zero-field-cooled behaviors was observed for Bi_(2)Ti_(2)O_(7)below estimated freezing temperature).The results of this study highlights the special role of Bi_(2)Ti_(2)O_(7)as a candidate material for studying aspects of geometric frustration related with pyrochlore structure in non-magnetic medium and specifies the future directions of research.展开更多
文摘Objective: To determine the impact of white matter hyperintensities(WMHs) on p hysical health and cognitive function in 60-64 year old individuals residing in the community. Methods:A subsample of 478 persons aged 60-64 from a larger com munity sample underwent brain magnetic resonance imaging(MRI) scans. WMHs on T2 weighted FLAIR (fluid attenuated inversion recovery) MRI scans were assessed usi ng anautomated procedure. Subjects were assessed for global cognitive function, episodic memory, working memory (digit span),information processing speed (Symbo l Digit Modalities Test;SDMT), fine motor dexterity (Purdue Pegboard), and grip strength, and completed the Physical Component Summary of the Short Form Health Survey (SF-12). Regression analyses were used to examine the effect of WMHs on physical and cognitive function. Results: Deep and periventricular WMHs were pre sent in all subjects, with women having slightly more lesions than men. WMHs wer e significantly associated with poorer reported physical health on the SF-12 sc ale, after adjusting for depression, cognitive function, and brain atrophy. WMHs were also related to lower scores on the Purdue Pegboard test, grip strength, c hoice reaction time, and SDMT, but not on tests of episodic memory, working memo ry, general intellectual function,and global cognitive function. On regression a nalyses, the Purdue Pegboard test and grip strength were related to physicaldisa bility. Conclusion: WMHs are common, albeit mild, in middle adult life. They are associated with physical disability,possibly through reduced speed, fine motor coordination, and muscular strength. They are also related to slowed information processing speed but not other cognitive functions.
基金The authors are grateful to L.A.Shilkina for X-ray phase analysis of the BZN samples.The reported study was funded by Russian Science Foundation(RSF)-research projects no.20-72-00086(BZN ceramics preparation,dielectric mea-surements)At RTU MIREA,the work was supported by the Ministry of Science and Higher Education of Russia(project FSFZ 0706-2020-2022,Bi2Ti2O7 single crystal growth),the equipment of the Center for Collective Use of RTU MIREA was used.
文摘The comparative analysis of the dielectric properties of bismuth-containing pyrochlores with different manifestation of atomic order/disorder was carried out.We examined the dielectric properties(including behavior in electric fields)of two pyrochlore compounds:BZN(presumably a composition close to Bi_(1.5)Zn_(0.5)Nb_(1.5)O_(6.5))ceramics with chemical disorder in both A and B cation sublattices and Bi_(2)Ti_(2)O_(7)single crystal with fully chemical ordered structure.The fundamental differences between the dielectric properties of the BZN ceramics and Bi_(2)Ti_(2)O_(7)single crystal were shown.In particular,in the dielectric relaxation behavior(which cannot be described via Arrhenius law in the Bi_(2)Ti_(2)O_(7))or in the influence of the electric fields on the dielectric permittivity(split-ting of the field-cooled and zero-field-cooled behaviors was observed for Bi_(2)Ti_(2)O_(7)below estimated freezing temperature).The results of this study highlights the special role of Bi_(2)Ti_(2)O_(7)as a candidate material for studying aspects of geometric frustration related with pyrochlore structure in non-magnetic medium and specifies the future directions of research.
