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College of Science and, Japan

Imai T.,Kyoto University | Kurihara T.,Kyoto University | Esaki N.,Kyoto University | Mihara H.M.,Ritsumeikan UniversityShiga
Bioscience, Biotechnology and Biochemistry | Year: 2014

Selenite is a selenium source for selenoprotein biosynthesis in mammalian cells. Although previous studies have suggested the involvement of glutathione (GSH) and/or thioredoxin reductase in selenite metabolism, intracellular selenite metabolism remains largely unknown. Here, we report that GSH depletion did not affect the amount of selenoprotein in Hepa 1-6 cells, suggesting that GSH does not play a central role in the reduction of selenite in selenoprotein biosynthesis. On the other hand, we found that GSH is involved in the efflux of lowmolecular-weight selenium compounds from cells, presumably via the formation of selenodiglutathione. Moreover, selenite inhibited the efflux of a fluorescent bimane-GS conjugate that is mediated by ATPdependent multidrug-resistant proteins, implying the existence of an active transporter for selenodiglutathione. This is the first report demonstrating that GSH plays a role in selenium excretion from cells by forming a GSH-conjugate, which may contribute to the distribution, detoxification, and homeostasis of selenium in the body. © 2014 Japan Society for Bioscience, Biotechnology, and Agrochemistry.

Dau V.T.,Sumitomo Chemical | Bui T.T.,Japan National Institute of Advanced Industrial Science and Technology | Dinh T.X.,Ritsumeikan UniversityShiga | Terebessy T.,Atrium Innovation Ltd.
Sensors and Actuators, A: Physical | Year: 2016

We present a pressure sensing unit based on a unique corona discharge setup using symmetrical electrode arrangement with simultaneous positive and negative corona generation. The device generates stable corona discharge and enables reliable air pressure measurement in the range of 80-105 kPa, tested with five prototypes. The current-voltage characteristics of bipolar discharge system is analyzed in general form and three governing parameters, namely electrode geometry, electrode distance and discharge current, are studied in relation with absolute pressure. The sensors are driven with constant discharge current as low as 1 μA. The measured sensitivity is in good agreement with theoretical prediction and the sensor stability has been confirmed with 20-h continuous test without sensitivity deterioration. The sensitivity does not depend on the tested temperature range and its variation between devices is small, approximately ±3.0%. The advantage of the proposed system compared with similar corona-based constructions is its stable operation at low current with low power consumption and minimum electrode deterioration, which provides a cost effective and reliable solution. & copy;2015 Elsevier B.V. All rights reserved.

Konno Y.,Ritsumeikan UniversityShiga | Han X.-H.,Ritsumeikan UniversityShiga | Lin L.,Zhejiang University | Hu H.,Zhejiang UniversityZhejiang | And 4 more authors.
Smart Innovation, Systems and Technologies | Year: 2016

Automatic liver lesion enhancement and detection has an essential role for the computer-aided diagnosis of liver tumor in CT volume data. This paper proposes a novel lesion enhancement strategy using Bayesian framework by combining the lesion probabilities based on an adaptive non-parametric model with the processed test volume and the constructed common non-lesion models with prepared liver database. Due to the large variation of different lesion tissues, it is difficult to obtain the common lesion prototypes from liver volumes, and thus this paper investigates a lesion-training-data free strategy by only constructing the healthy liver and vessel prototypes using local patches, which can be extracted from any slice of the test liver volume, and is also easy to prepare the common training non-lesion samples for all volumes. With the healthy liver and vessel prototypes from the test volume, an adaptive non-parametric model is constructed for estimating the lesion possibility, which is considered as the pixel likelihood to lesion region; the common model constructed using the pre-prepared liver database is used to estimate the pixel probability, which is defined as prior knowledge due to the used unvaried model. Finally, the posterior probabilities based on Bayesian theory are achieved for enhancing lesion regions. Experimental results validate that the proposed framework can not only detect almost small lesion regions but also greatly reduce falsely detect regions. © Springer International Publishing Switzerland 2016.

Fujii R.,Ritsumeikan UniversityShiga | Tateyama T.,Ritsumeikan UniversityShiga | Kitrungrotsakul T.,Ritsumeikan UniversityShiga | Tanaka S.,Ritsumeikan UniversityShiga | Chen Y.-W.,Zhejiang University
Smart Innovation, Systems and Technologies | Year: 2016

The purpose of this study is to construct a system for surgical assistance by touchless interactions. In the clinical site, surgeons usually need to use some contacting devices to display or visualize medical images and check the anatomic information of the patient. However, after operating the visualization device, re-sterilization is necessary in order to maintain hygiene. Though some touchless surgery support systems using Kinect have been developed, their functions are not enough for surgical support. In this paper, we develop a new system, which can visualize 3D medical image by simple touchless single-handed interactions. © Springer International Publishing Switzerland 2016.

Yasuda H.,Ritsumeikan UniversityShiga | Sakaue Y.,Ritsumeikan UniversityShiga | Tanaka M.,Osaka Dental University | Matsushima M.,Kurary CO. | And 4 more authors.
Transactions of Japanese Society for Medical and Biological Engineering | Year: 2014

Chewing is thought to be important for normal swallowing, because it fixes the human mandible on proper place. When fulcrum of tongue movement vanishes, it becomes difficult to roll food bolus and saliva into pharynx by tongue. The purpose of this study is to develop a new swallowing measurement system focused on the movement of prominentia laryngea and mandible to estimate the swallowing mechanism. In our measurement system, a flexible polymer curvature sensor (FPCS), that converts its bending curvature into voltage, was used to measure the movement of prominentia laryngea and mandible during swallowing. FPCSs were attached on prominentia laryngea and bulging of masseter in the vicinity of mandible. The waveforms of FPCSs changed according to swallowing. Results suggest that the swallowing test focusing on movement of prominentia laryngea and mandible is possible. © 2014, Japan Soc. of Med. Electronics and Biol. Engineering. All rights reserved.

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