Former Olympians had remained on high bone mineral density for a long period: Consecutive checkup of the 1964 Tokyo Olympic Japanese contestants for over 50 years.

INTRODUCTION: We performed consecutive checkups of the 1964 Tokyo Olympic contestants every 4 years for 50 years. This study evaluated bone mineral density (BMD) and its related factors in former Tokyo Olympic athletes. OBJECTIVES: The study population comprised 181 former Olympians (141 men and 40 women) who had undergone BMD measurement in at least one of the four checkups performed every 4 years since 2005. The mean age of the 104 subjects who participated in the last checkup in 2016 was 76.1 years for men and 74.0 years for women. METHODS: Health-related information regarding medical history, regular physical activity, alcohol consumption, and smoking was obtained using questionnaires. The areal BMD of the total body was measured using dual-energy X-ray absorptiometry (DXA). The relationship between BMD and anthropometric measurements, medical history, and health behaviors was examined. Furthermore, we assessed the influence of the mode and magnitude of weight-bearing and impact loading during athletic events during their active careers on BMD. RESULTS: The mean Z-scores of BMD of the total body, lumbar spine, pelvis, and upper and lower limbs were > 0 in both male and female subjects at each checkup. The subjects had a higher mean height and weight than the Japanese age- and sex-matched individuals. Furthermore, the subjects had higher grip strength than the age- and sex-matched individuals. BMD showed a positive correlation with body weight, lean body mass (LBM), muscle mass, and grip strength, with higher correlation coefficients found between BMD of the pelvis or lower limbs and LBM or muscle mass volume. When the association with current participation in sports activities was examined, male subjects who exercised weekly had significantly higher grip strength and greater muscle mass volume; however, no significant differences were observed among female subjects. After adjusting for age and LMB, BMD was significantly higher in both the lumbar spine and lower limbs of male subjects with relatively more impact loading in sports events during their active careers. CONCLUSION: The Tokyo Olympic contestants maintained a high muscle mass even at an older age, regardless of their medical history, which may be one of the reasons for their ability to maintain a high BMD.

Nuclear and magnetic spin structure of the antiferromagnetic triangular lattice compound LiCrTe2 investigated by [Formula: see text]SR, neutron and X-ray diffraction.

Two-dimensional (2D) triangular lattice antiferromagnets (2D-TLA) often manifest intriguing physical and technological properties, due to the strong interplay between lattice geometry and electronic properties. The recently synthesized 2-dimensional transition metal dichalcogenide LiCrTe[Formula: see text], being a 2D-TLA, enriched the range of materials which can present such properties. In this work, muon spin rotation ([Formula: see text]SR) and neutron powder diffraction (NPD) have been utilized to reveal the true magnetic nature and ground state of LiCrTe[Formula: see text]. From high-resolution NPD the magnetic spin order at base-temperature is not, as previously suggested, helical, but rather collinear antiferromagnetic (AFM) with ferromagnetic (FM) spin coupling within the ab-plane and AFM coupling along the c-axis. The value if the ordered magnetic Cr moment is established as [Formula: see text]. From detailed [Formula: see text]SR measurements we observe an AFM ordering temperature [Formula: see text] K. This value is remarkably higher than the one previously reported by magnetic bulk measurements. From [Formula: see text]SR we are able to extract the magnetic order parameter, whose critical exponent allows us to categorize LiCrTe[Formula: see text] in the 3D Heisenberg AFM universality class. Finally, by combining our magnetic studies with high-resolution synchrotron X-ray diffraction (XRD), we find a clear coupling between the nuclear and magnetic spin lattices. This suggests the possibility for a strong magnon-phonon coupling, similar to what has been previously observed in the closely related compound LiCrO[Formula: see text].

Quantitative analysis of the resorption and osteoconduction process of a calcium phosphate cement and its mechanical effect for screw fixation.

The clinical application of calcium phosphate cements (CPCs) composed of tetracalcium phosphate and dicalcium phosphate anhydrous has been limited because of its longer setting time, so that we developed the CPC in which the setting time was shortened to approximately 10 min. Aiming at clinical application, we evaluated the histological response in the bone quantitatively and the biomechanical effectiveness of this substance. The CPC was implanted in the rabbit femoral condyle up to 52 weeks for histological evaluation. In mechanical testing, small cancellous screws were inserted into the condyle, both with and without augmentation with the CPC, and the pull-out strength was measured. The micro-computed tomography finding demonstrated that the cross-sectional area of the implanted CPC at 24 weeks was approximately two-thirds of the initial area. The amount of newly calcified bone around the CPC was significantly greater than that of the sintered hydroxyapatite. Histologically, the new bone was formed on the surface of the implanted CPC 1 week after the implantation and resorption of the CPC was evident at 3 weeks. The pull-out strength was enhanced significantly by augmentation with the CPC and the initial strength was maintained for a 6 week period. This CPC showed good osteoconductivity and was resorbed without adverse inflammation. Using the CPC as augmentation may be capable of useful treatment options in fractures with poor bone quality.