Human muscular skeleton structure plays an important role for adaptive locomotion. Understanding of its mechanism is expected to be used for realizing adaptive locomotion of a humanoid robot as well. In this paper, a jumping robot driven by pneumatic artificial muscles is designed to duplicate human leg structure and function. It has three joints and nine muscles, three of them are biarticular muscles. For controlling such a redundant robot, we take biomechanical findings into account: biarticular muscles mainly contribute to joint coordination whereas monoarticular muscles contribute to provide power. Through experiments, we find (1) the biarticular muscles realize coordinated movement of joints when knee and/or hip is extended, (2) the extension of the ankle does not lead to coordinated movement, and (3) we can superpose extension of the knee with that of the hip without losing the joint coordination. The obtained knowledge can be used not only for robots, but may also contribute to understanding of adaptive human mechanism.

Hydrogenation of diamond has been carried out using the electron-cyclotron-resonance microwave plasma chemical-vapor deposition apparatus. According to reflection high-energy and low-energy electron diffraction and X-ray photoelectron spectroscopy measurements, the natural- and synthetic-diamond surfaces maintained their crystallinity even after the hydrogenation. Seebeck effect measurement and the temperature dependence of the resistance revealed an appearance of deep acceptor levels in the hydrogenated diamond layer. The diffusion depth of the hydrogen by the plasma treatment (2 h, 830°C) was roughly estimated to be ∼0.6 µm from the drain current-voltage characteristics of a rudimentary MISFET using the hydrogenated diamond.

Optical frequency combs are innovative tools for broadband spectroscopy because a series of comb modes can serve as frequency markers that are traceable to a microwave frequency standard. However, a mode distribution that is too discrete limits the spectral sampling interval to the mode frequency spacing even though individual mode linewidth is sufficiently narrow. Here, using a combination of a spectral interleaving and dual-comb spectroscopy in the terahertz (THz) region, we achieved a spectral sampling interval equal to the mode linewidth rather than the mode spacing. The spectrally interleaved THz comb was realized by sweeping the laser repetition frequency and interleaving additional frequency marks. In low-pressure gas spectroscopy, we achieved an improved spectral sampling density of 2.5 MHz and enhanced spectral accuracy of 8.39 × 10−7 in the THz region. The proposed method is a powerful tool for simultaneously achieving high resolution, high accuracy, and broad spectral coverage in THz spectroscopy.

Radiotherapy is a commonly used regimen for treating various types of intractable cancers, although the effects depend on the cell cycle of the targeted cancer cell lines, and for irradiation purposes it is therefore critical to establish a protocol for controlling the cell cycle. Here, we showed that a common murine melanoma cell line B16BL6 was more vulnerable to irradiation during the early S phase, and that synchronisation of the cell cycle greatly increased the therapeutic effects of radiotherapy. Cell-sorting experiments, according to cell-cycle phase, using B16BL6 cells demonstrated that cells in the early S phase were the most susceptible to radiotherapy. Gemcitabine, a clinically utilised anti-cancer drug, induced cell-cycle arrest during the early S phase in B16BL6 cells, and thus a synergistic therapeutic effect was observed when irradiation was administered at the right time. Human pancreatic cancer cell line PANC-1 exhibited similar properties to B16BL6 in terms of its radiosensitivity during the S/G2/M phase and also demonstrated a synergistic effect of cell cycle synchronisation. These results show the importance of cell-cycle control in the application of irradiation and suggest a suitable time interval between chemotherapy and radiotherapy, as well as providing useful information for treating intractable cancer.

Terahertz (THz) dual comb spectroscopy (DCS) is a promising method for high-accuracy, high-resolution, broadband THz spectroscopy because the mode-resolved THz comb spectrum includes both broadband THz radiation and narrow-line CW-THz radiation characteristics. In addition, all frequency modes of a THz comb can be phase-locked to a microwave frequency standard, providing excellent traceability. However, the need for stabilization of dual femtosecond lasers has often hindered its wide use. To overcome this limitation, here we have demonstrated adaptive-sampling THz-DCS, allowing the use of free-running femtosecond lasers. To correct the fluctuation of the time and frequency scales caused by the laser timing jitter, an adaptive sampling clock is generated by dual THz-comb-referenced spectrum analysers and is used for a timing clock signal in a data acquisition board. The results not only indicated the successful implementation of THz-DCS with free-running lasers but also showed that this configuration outperforms standard THz-DCS with stabilized lasers due to the slight jitter remained in the stabilized lasers.