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Abstract  

Positron annihilation lifetime measurement and Fourier transform infrared spectrometry were applied to the study of temperature dependencies of free volume parameters and hydrogen bonds in segmented polyurethane, specially fabricated as a shape memory polymer. The variation of free volumes in amorphous region were correlated to that of hydrogen bonding and the shape memory mechanism of polyurethane is elucidated from a microscopic point of view. The relationship between free volume contents and the formation of hydrogen bonds significantly suggests that the shape memory occurs due to the configurational recovery of the microscopic regulation around urethane bundles of hard segment and consequent restoration of soft-segment in polyurethane.

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Summary Thermodynamic properties of a layered perovskite oxide Gd2SrCo2O7 have been studied. Powder X-ray diffraction, electric resistivity, magnetic susceptibility and heat capacity measurements were carried out. The crystal structure was determined as I4/mmm. The temperature dependence of the magnetic susceptibility was fitted to the Curie-Weiss behavior with antiferromagnetic interaction. Spin state of Co3+ ion was derived to be intermediate spin state configuration (t2g 5eg 1). The spin ordering was observed as a broad anomaly in the heat capacity curve with a peak at 2 K. The measured entropy was 35.47 J K-1mol-1, which was 65% of expected value. Thus the spin ordering should not be completed at the lowest temperature 0.2 K covered in the present experiments and/or some short range ordering remains at higher temperatures.

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It has been shown that the tissue oxygen index (TOI) measured by near-infrared spectroscopy oscillates at very low frequencies during recovery after exercise and that this oscillation is derived from interactions among biochemical substances involved in oxidative metabolism in skeletal muscle. As a further step, we examined whether TOI in muscle interacts through oscillation with factors related to oxygen in the cardiorespiratory system. For this examination, coherence and phase difference between the TOI in the vastus lateralis and heart rate (HR) and between TOI and arterial oxygen saturation (SpO2) were sequentially determined during recovery (2–60 min) after severe cycle exercise with a workload of 7.5% of body weight for 20 s. Significant coherence between TOI and HR was obtained in the very low-frequency band (approximate range: 0.002–0.03 Hz) and in the low-frequency band (approximate range: 0.06–0.12 Hz). The phase difference was negative in the low-frequency band and positive in the very low-frequency band. The coherence between TOI and SpO2 was significant in the very low-frequency band. The phase difference was negative. There were no sequential changes in these coherences and phase differences. The results suggest that TOI in skeletal muscle interrelates with factors related to the heart and lungs.

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Journal of Radioanalytical and Nuclear Chemistry
Authors: K. Takamiya, R. Okumura, N. Abe, Y. Nakano, K. Miyata, S. Fukutani, A. Taniguchi, and H. Yamana

Abstract  

The new control system of pneumatic transportation apparatuses for neutron irradiation in Kyoto University Reactor (KUR) has been developed based on the TCP/IP network for the purpose of integrated management of the apparatus. The control system is comprised of PLCs, control PCs, database and web servers. Archiving logs of detailed information about irradiation enables the secure operation and management of the irradiation system. The information stored in the server can be referred by remote PCs and mobile phones through the internet. Combining the present facility with measurement and radiation management systems it can realize advanced INAA methods and secure managements of radioisotopes.

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To investigate the relationships between site-specific muscle loss in the thigh, muscle quality and zigzag walking performance, 40 men and 41 women aged 65–79 years had muscle thickness (MTH) measured by ultrasound at nine sites on the anterior and posterior aspects of the body. Skeletal muscle mass (SM) was estimated from an ultrasoundderived prediction equation. Site-specific thigh sarcopenia was calculated using ultrasound-measured MTH at the anterior/posterior aspects of the thigh (AP-MTH ratio). Zigzag walking time (ZWT) and maximum isometric knee extension (KE) and flexion (KF) torques were measured. Muscle quality (torque/thigh SM) and knee joint strength index (torque/body mass) were calculated. There were no significant correlations between SM index and ZWT. However, AP-MTH ratio was inversely correlated (P < 0.05) to ZWT in men (r = −0.335) and women (r = −0.309). ZWT was also inversely correlated (P < 0.05) to KE-strength index in both sexes (men, r = −0.328; women, r = −0.372). Similarly, ZWT was correlated to KF-strength index (r = −0.497) and muscle quality (r = −0.322) in women, but not in men. After adjusting for age, height and body mass, AP-MTH ratio was inversely correlated to ZWT in men (r = −0.325) and tended to be correlated to ZWT in women (r = −0.263). Zigzag walking performance may be associated with site-specific thigh sarcopenia in older men and women.

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