著者

Lisa Yamasaki Soichiro Saeki Hatsune Kido Takao Suzuki

出版者

JAPAN ASSOCIATION FOR INTERNATIONAL HEALTH

雑誌

国際保健医療 (ISSN:09176543)

巻号頁・発行日

vol.35, no.4, pp.265-266, 2020-12-20 (Released:2021-03-16)

著者

鈴木 崇夫 スズキ タカオ Takao SUZUKI

雑誌

医事学研究

巻号頁・発行日

vol.10, pp.1-32, 1995-12-10

著者

Keiko Hirakawa Kaoru Koike Yoshimasa Kanawaku Tsuyoshi Moriyama Norio Sato Takao Suzuki Kenichi Furihata Youkichi Ohno

出版者

Japan Oil Chemists' Society

雑誌

Journal of Oleo Science (ISSN:13458957)

巻号頁・発行日

pp.ess18212, (Released:2019-03-13)

被引用文献数

6

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Proton nuclear magnetic resonance (NMR) is useful for the analysis of biological samples such as serum. Free induction decays (FIDs) are NMR signals that follow a radio-frequency pulse applied at the resonance frequency. Short-time Fourier transform (STFT) is a basic method for time-frequency analyses. The purpose of this study was to ascertain whether the STFT of FIDs enables the sensitive detection of changes and differences in serum properties. FIDs were obtained from serum collected from young, healthy, male volunteers ≤ 40 years of age and seniors ≥ 65 years of age. Temporal changes in the instantaneous amplitudes for the time-domain analysis, fast Fourier transform for frequency-domain analysis, and STFT were applied to the FIDs. The STFT-based spectrogram represented the complex frequency components that changed dynamically over time, indicating that the spectrogram enabled the visualization of the features of an FID. Furthermore, the results of a partial least-squares discriminant analysis demonstrated that the STFT was superior to the other two methods for discriminating between serum from younger and older subjects. In conclusion, the STFT of FIDs obtained from proton NMR measurements was useful for evaluating similarities and dissimilarities in the FIDs obtained from serum samples.

著者

Tatsuro Ishizaki Taketo Furuna Yuko Yoshida Hajime Iwasa Hiroyuki Shimada Hideyo Yoshida Shu Kumagai Takao Suzuki

出版者

日本疫学会

雑誌

Journal of Epidemiology (ISSN:09175040)

巻号頁・発行日

vol.21, no.3, pp.176-183, 2011-05-05 (Released:2011-05-05)

参考文献数

33

被引用文献数

11 27

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Background: Few studies have examined whether declines over time in hand-grip strength (HGS) and fast walking speed (FWS) differ by sex and age among non-Western community-dwelling older adults. This study aimed to quantify changes in HGS and FWS over the 6-year period from 1994 to 2000 and examine whether these changes differed by sex and baseline age among older individuals in a Japanese community.Methods: We conducted a community-based prospective cohort study. The participants were 513 nondisabled men and women aged 67 to 91 years at the 1994 survey. Independent variables regarding time since baseline, in addition to various time-dependent and time-independent covariates, were obtained in 1994, 1996, 1998, and 2000. The outcome variables were HGS and FWS assessed at each survey. All data on independent and dependent variables that were collected at each survey were simultaneously analyzed using a linear mixed-effects model.Results: The linear mixed-effects model revealed significant declines in both HGS (−0.70 kg/year, P < 0.001) and FWS (−0.027 m/sec/year, P < 0.001) among nondisabled older participants who had analyzable data in any survey during the 6-year period. Sex was significantly associated with the rate of decline in HGS (P < 0.001), but not FWS (P = 0.211).Conclusions: In this analysis of nondisabled older Japanese, a mixed-effects model confirmed a significant effect of aging on declines in HGS and FWS and showed that men had a significantly steeper decline in HGS than did women during a 6-year period.