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Carbon microcrystallites can become oriented in the carbonization process of coal tar pitch, which occurs with the characteristic where a mesophase is obtained, by using a magnetic field. An oriented film that has the ability to transmit visible light from 450 to 800 nm can be obtained by sandwiching an appropriate amount of coal pitch between two glass plates and heating in an inert atmosphere at 793 K under a magnetic field. This film can be used to obtain the same linearly polarized light as a commercially available polarizing element. The degree of orientation of the film prepared in a magnetic field of 3 T is not sufficient to use as a polarizer, but a magnetic field of 6 T is able to sufficiently suppress the passage of crossed polarized light. The electrical conductivity of the carbon film prepared at 793 K is improved by 10 times by the application of a magnetic field of 10 T. The electrical conductivity is sensitive to the magnetic field, and there is a possibility that it can be further improved by applying 10 T or more. Coal tar pitch is the residue after obtaining coke from coal, and the optical and electrical advantage of a material prepared in the magnetic field derived from such natural products is clarified.

[Purpose] The purpose of this study was to clarify the correlation between the range of spinal mobility on the sagittal plane and the dynamic balance ability of elderly people living in communities. [Subjects and Methods] The persons studied were 31 healthy elderly people living in the community (16 females and 15 males). The range of mobility of the participants’ spines in the sagittal plane was measured by using a spinal mouse®. Balance ability was evaluated by using Functional reach (FR), Timed up and go (TUG), and Maximum walking speed (MWS). [Results] A significant positive correlation between the flexion range of the lumbar vertebrae and the FR distance was identified, and a significant negative correlation between the extension range of the thoracic vertebrae and the time required for TUG was also identified. In addition, a significant positive correlation between the extension range of the entire spine and MWS, was identified. [Conclusion] The result of this study have clarified that mobility of the spine in the sagittal plane is associated with dynamic balance ability, which is related to falling.

Posturography is utilized to assess the influence of aging on postural control. Although this measurement is advantageous for finding group-level differences between the young and the elderly, it is unclear whether it has the potential to differentiate elderly individuals who are affected by various impacts of aging. The purpose of this study was to determine the utility of posturography to discriminate elderly individuals from young adults. We investigated the performances of the random forest classifiers constructed from center of pressure (COP) indices for discriminating standing postures between healthy elderly and young people. Postural sways in 19 young and 31 community-dwelling elderly participants were measured using force plates in 4 standing conditions: bipedal standing, standing on a narrow base, standing on foam rubber, and standing with eyes closed. We further verified the informative predictors that contributed to the prediction model. As the results, the classifier based on the COP indices for standing on foam rubber showed the best performance (accuracy: 93.4%, sensitivity: 94.4%, specificity: 93.6%, area under the curve of receiving operator characteristics: 0.95), followed by the classifier for standing with eyes closed. The informative predictors varied depending on the postural conditions. Our findings demonstrated the potential of posturography for identifying elderly postures. The evaluation of sensory re-weighting using the appropriate COP indices would be a useful clinical tool for detecting the progress of aging on postural control.

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