Grain-size adjustment in Hf0.5Zr0.5O2ferroelectric film to improve the switching time in Hf0.5Zr0.5O2-based ferroelectric capacitor.

By adjusting the rising time in annealing ferroelectric HfO2-based films, the grain size of the film can be controlled. In this study, we found that increasing the rising time from 10 to 30 s at an annealing temperature of 700 °C in N2atmosphere resulted in improved ferroelectric switching speed. This is because the larger grain size reduces the internal resistance components, such as the grain bulk resistance and grain boundary resistance, of the HZO film. This in turn lowers the overall equivalent resistance. By minimizing the RC time constants, increasing the grain size plays a key role in improving the polarization switching speed of ferroelectric films.

[Validity and reliability of the "Trail Making Peg" test as a performance measurement for evaluating the cognitive function].

AIM: To investigate the validity and reliability of a novel performance test, called the "Trail Making Peg" (TMP) test, for evaluating the cognitive function. METHODS: We recruited 632 community-dwelling older adults (mean age: 73.3±5.2 years) as subjects for the assessment of the validity of the test and 319 adults (mean age: 73.1±5.2 years) as subjects for the assessment of reliability. Five cognitive tests (5-Cog) were used to evaluate the cognitive function, and the degree of cognitive decline was delineated for subjects scoring below 1 SD from the mean 5-Cog score. A receiver operating characteristic analysis was employed to calculate the cut-off point. RESULTS: There were no sex differences in the TMP scores (P=0.951), and the TMP and 5-Cog scores were found to correlate significantly (r=-0.63) with each other. The Trail Making Peg test demonstrated an area under the curve of 0.855 for discriminating between non-cognitive decline and cognitive decline. At this cutoff point, the sensitivity was 85% and the specificity was 69%. The intraclass correlation coefficient of the TMP was 0.746. CONCLUSIONS: The TMP exhibits sufficient validity and reliability. Our results suggest that TMP is a useful screening test for detecting cognitive decline.

Age and gender differences in correlations of leisure-time, household, and work-related physical activity with physical performance in older Japanese adults.

AIM: This study aimed to compare relationships of leisure-time, household, and work-related physical activity (PA) with physical performance by age and gender in older Japanese adults. METHODS: This cross-sectional study included 525 community-dwelling older adults (73.3 ± 5.2 years) recruited in 2009-2011 in Kasama City, rural Japan. We used the Physical Activity Scale for the Elderly to assess PA variables. Physical performance was evaluated by 11 performance tests: grip strength, single-leg balance, functional reach, sit-and-reach, standing time from long sitting position, sit-to-stand, timed up and go, habitual walk, hand working, and simple and choice reaction times. RESULTS: After adjusting for potential confounders, leisure-time PA in young-old (≤ 74 years) men correlated significantly with eight performance tests (absolute value of Spearman's partial rank correlation coefficient: r = 0.18-0.39), whereas in old-old (≥ 75 years) men it correlated with three performance tests (r = 0.20-0.23). Although leisure-time PA correlated with six performance tests (r = 0.19-0.22) in young-old women, there were no significant correlations between leisure-time PA and performance tests in old-old women. Household PA of young-old men (r = 0.20-0.23) and old-old women (r = 0.26-0.34) correlated with four performance tests. In old-old men and young-old women, no significant correlation was found between household PA and performance tests. Work-related PA did not relate significantly to any performance tests in any groups. CONCLUSION: This study showed that leisure-time PA is related to physical performance, especially in young-old men and women, and household PA is especially related in young-old men and old-old women. Our findings suggest that supporting strategies for maintaining physical functions would differ by gender and age.

Associations of physical activity with neighborhood environments and transportation modes in older Japanese adults.

OBJECTIVE: We investigated associations of walking and other leisure-time physical activity (LTPA) with environmental characteristics and transportation modes in older Japanese adults. METHODS: This cross-sectional study in 2010-2011 used data from 421 community-dwelling older adults aged 65-85 years living in Kasama City, rural Japan. We used the Physical Activity Scale for the Elderly to assess walking and other LTPAs, and the International Physical Activity Questionnaire Environment Module for neighborhood environments. RESULTS: After adjusting for confounders, we found that good traffic safety and aesthetics were positively associated with high levels of walking (ORs=1.64-2.12); whereas, good access to public transportation was negatively associated with walking (OR=0.64, 95% CI=0.42-0.98). Good access to recreational facilities, presence of sidewalks, absence of hills, seeing people exercise, and aesthetically pleasing surroundings were positively associated with high levels of LTPA except walking (ORs=1.61-2.13). Individuals who rode bicycles more than once per week were more likely to engage in a LTPA except walking (1-3 days: OR=1.72, 95% CI=1.03-2.87; ≥4 days: OR=2.90, 95% CI=1.71-4.93). CONCLUSION: This study adds information on correlates of physical activity among older Japanese adults; the positive association between LTPA except walking and the frequency of bicycle travel is an especially new and intriguing finding.

[Association of the physical activity of community-dwelling older adults with transportation modes, depression and social networks].

AIM: The purpose of this study was to cross-sectionally examine the relationships among leisure, household and occupational physical activity with the frequency of going out by various transportation modes, depression and social networks in older adults. METHODS: We randomly selected a total of 2,100 community-dwelling adults aged 65 to 85 years of age from the Basic Resident Register. Of these, 340 people were the subjects of this study. The scales of measurement used were the Physical Activity Scale for the Elderly, the Lubben Social Network Scale (LSNS) and the Geriatric Depression Scale (GDS). RESULTS: In a regression model, leisure-time physical activity significantly correlated with frequency of going out by bicycle (ß=0.17) and LSNS score (ß=0.17). Household physical activity and occupational physical activity were significantly correlated with LSNS score (ß=0.21) and frequency of going out by motor vehicle (ß=0.25), respectively. For total physical activity, in the 3 above-mentioned activities a significant correlation was observed among frequency of going out by bicycle (ß=0.10), by motor vehicle (ß=0.23), GDS score (ß=-0.16) and LSNS score (ß=0.23). CONCLUSION: These results indicate that the frequency of going out by bicycle and by motor vehicle were significant factors to predict leisure and occupational physical activity. Furthermore, social networks appear to be important determiners in leisure and household physical activity in community-dwelling older adults.

[Association of physical functions with leisure-time, household, and occupational physical activity in community-dwelling older adults].

AIM: The study objective was to cross-sectionally examine the relationships among leisure-time, household, and occupational physical activity with physical functions in Japanese older adults. METHODS: We randomly enrolled 189 community-dwelling older adults, aged 65 to 85 years, as subjects from the Basic Resident Register of Kasama City, Ibaraki prefecture. Physical activity was assessed by the Physical Activity Scale for the Elderly. Analysis of covariance was performed to determine the relationships between physical activity and physical functions, after adjustment for age and sex. RESULTS: Leisure-time physical activity significantly correlated with one-leg balance with eyes open, sit and reach, timed standing test from along sitting position on the floor, functional reach, 5-repetition sit-to-stand, timed up and go, 5-m habitual walk, choice stepping reaction time, and power in sit-to-stand tests. Household physical activity was significantly related to 5-repetition sit-to-stand and ability in sit-to-stand. Total (leisure-time plus household plus occupational) activity was significantly correlated with one-leg balance with eyes open, functional reach, and power in sit-to-stand tests. Post-hoc testing indicated that the levels of physical functions were higher in the subjects of the third tertile than in those of the first or second tertile. No difference was found in physical functions between the first and second tertile. CONCLUSION: Leisure-time physical activity was related to many physical functions. Household physical activity was also related to lower-extremity functions. Our data suggest that medium- or high-level physical activity may be necessary for older adults to maintain their physical functions.