Ground Reaction Force in Sit-to-stand Movement Reflects Lower Limb Muscle Strength and Power in Community-dwelling Older Adults

Background: Ground reaction force parameters in a sit-to-stand (STS) movement can be used to evaluate lower extremity function. Few reports, however, are available on whether the ground reaction force parameters in an STS movement reflect dynamic knee and ankle strength or power. The aims of this study were to examine associations among ground reaction force parameters in an STS movement and isokinetic knee and ankle strength and power in healthy older adults, and to compare associations with the five-times STS test. Methods: The following five ground reaction force parameters were measured in 19 men and 28 women: peak reaction force, two rate of force development (RFD) parameters and two time-related parameters. Results: RFD (Δ90 ms)/body weight correlated significantly with average isokinetic knee extension/flexion power in both sexes (partial-r = 0.39–0.54) and average ankle plantar flexion and dorsiflexion power (partial-r = 0.50 and partial-r = 0.49, respectively), in women. No isokinetic parameters were significantly related to the five-times STS test. Conclusion: Ground reaction force parameters in an STS movement can accurately reflect the dynamic strength and power in the lower limbs, which is approximately equal to or better than the strength and power reflected by the five-times STS test

Selective emergence of photoluminescence at telecommunication wavelengths from cyclic perfluoroalkylated carbon nanotubes

Abstract Chemical functionalisation of semiconducting single-walled carbon nanotubes (SWNTs) can tune their local band gaps to induce near-infrared (NIR) photoluminescence (PL). However, tuning the PL to telecommunication wavelengths (>1300 nm) remains challenging. The selective emergence of NIR PL at the longest emission wavelength of 1320 nm was successfully achieved in (6,5) SWNTs via cyclic perfluoroalkylation. Chiral separation of the functionalised SWNTs showed that this functionalisation was also effective in SWNTs with five different chiral angles. The local band gap modulation mechanism was also studied using density functional theory calculations, which suggested the effects of the addenda and addition positions on the emergence of the longest-wavelength PL. These findings increase our understanding of the functionalised SWNT structure and methods for controlling the local band gap, which will contribute to the development and application of NIR light-emitting materials with widely extended emission and excitation wavelengths

Impact of Robotic Assistance on Precision of Vitreoretinal Surgical Procedures

<div><p>Purpose</p><p>To elucidate the merits of robotic application for vitreoretinal maneuver in comparison to conventional manual performance using an <i>in-vitro</i> eye model constructed for the present study.</p><p>Methods</p><p>Capability to accurately approach the target on the fundus, to stabilize the manipulator tip just above the fundus, and to perceive the contact of the manipulator tip with the fundus were tested. The accuracies were compared between the robotic and manual control, as well as between ophthalmologists and engineering students.</p><p>Results</p><p>In case of manual control, ophthalmologists were superior to engineering students in all the 3 test procedures. Robotic assistance significantly improved accuracy of all the test procedures performed by engineering students. For the ophthalmologists including a specialist of vitreoretinal surgery, robotic assistance enhanced the accuracy in the stabilization of manipulator tip (from 90.9 µm to 14.9 µm, P = 0.0006) and the perception of contact with the fundus (from 20.0 mN to 7.84 mN, P = 0.046), while robotic assistance did not improve pointing accuracy.</p><p>Conclusions</p><p>It was confirmed that telerobotic assistance has a potential to significantly improve precision in vitreoretinal procedures in both experienced and inexperienced hands.</p></div

System to evaluate force applied on the fundus for test procedure 3, perception of contact with the fundus.

<p>An amplifier detected the voltage changes converted from the applied force change on the load cell. The amplifier was calibrated to measure 30 mN as 1 V change. The values of changes in voltage were shown with noise filtering in the data logger, and recorded on the computer.</p

Comparison of manual and telerobotic control by ophthalmologists and engineering students in test procedure 2, positioning stability.

<p>(mean ± SEM; n = 4−5 per group; ***P<0.001).</p

Comparison of manual and telerobotic control by ophthalmologists and engineering students in test procedure 1, aiming accuracy.

<p>(mean ± SEM; n = 4−5 per group; *P<0.05).</p