Seiji Koga, Satoshi Ikeda, Tomohiko Yasunaga, Tomoo Nakata, Koji Maemura,
Previous studies have shown a possible role for obstructive sleep apnea syndrome (OSAS) in the development and/or progression of chronic kidney disease (CKD). However, the impact of treatment for OSAS on CKD has not been clarified. The aim of this study was to investigate the influence of OSAS and the short-term effects of nasal continuous positive airway pressure (CPAP) on the estimated glomerular filtration rate (eGFR).We evaluated 38 men with OSAS diagnosed on polysomnography. The associations between ...
Tópico(s): Neuroscience of respiration and sleep
2013 - The Japanese Society of Internal Medicine | Internal Medicine
T. Nakata, Koji Fujiwara, N. Takahashi, Masami Nakano, Naotaka Okamoto,
The method for analyzing flux distributions in transformer cores made of grain-oriented silicon steel is improved in order to reduce error in calculation due to anisotropy in magnetic materials. A model to verify the improved method is proposed, and the calculated results are compared with measured ones. >
Tópico(s): Microstructure and Mechanical Properties of Steels
1994 - IEEE Magnetics Society | IEEE Transactions on Magnetics
Benchmark problem 13 of the TEAM Workshop consists of steel plates around a coil (a nonlinear magnetostatic problem). Seventeen computer codes developed by twelve groups are applied, and twenty‐five solutions are compared with each other and with experimental results. In addition to the numerical calculations, two theoretical presentations are given in order to explain discrepancies between the calculations and the experiment.
Tópico(s): Non-Destructive Testing Techniques
1992 - Emerald Publishing Limited | COMPEL The International Journal for Computation and Mathematics in Electrical and Electronic Engineering
Benchmark problem 10 of the TEAM workshop consists of steel plates around a coil (non‐linear transient eddy current problem). Six computer codes are applied, and 6 solutions are compared with each other and experimental results for eddy current densities as well as flux densities. Some codes were found to give oscillatory solutions.
Tópico(s): Non-Destructive Testing Techniques
1990 - Emerald Publishing Limited | COMPEL The International Journal for Computation and Mathematics in Electrical and Electronic Engineering
Yoshiki Nakata, Koji Tsubakimoto, N. Miyanaga, Aiko Narazaki, Tatsuya Shoji, Yasuyuki Tsuboi,
Noble metal nanodots have been applied to plasmonic devices, catalysts, and highly sensitive detection in bioinstruments. We have been studying the fabrications of them through a laser-induced dot transfer (LIDT) technique, a type of laser-induced forward transfer (LIFT), in which nanodots several hundred nm in diameter are produced via a solid–liquid–solid (SLS) mechanism. In the previous study, an interference laser processing technique was applied to LIDT, and aligned Au nanodots were successfully ...
Tópico(s): Laser-Ablation Synthesis of Nanoparticles
2021 - Multidisciplinary Digital Publishing Institute | Nanomaterials
Akira Sato, K. Matsubayashi, Toshitaka Morishima, Kayo Nakata, Koji Kawakami, Isao Miyashiro,
Abstract Background Cancer survivors are frequently excluded from clinical research, resulting in their omission from the development of many cancer treatment strategies. Quantifying the prevalence of prior cancer in newly diagnosed cancer patients can inform research and clinical practice. This study aimed to describe the prevalence, characteristics, and trends of prior cancer in newly diagnosed cancer patients in Japan. Methods Using Osaka Cancer Registry data, we examined the prevalence, characteristics, ...
Tópico(s): Cancer Diagnosis and Treatment
2021 - BioMed Central | BMC Cancer
Chihiro Koyama, Shuta Tahara, Shinji Kohara, Yohei Onodera, Didrik R. Småbråten, Sverre M. Selbach, Jaakko Akola, Takehiko Ishikawa, Atsunobu Masuno, Akitoshi Mizuno, Junpei Okada, Yūki Watanabe, Yui Nakata, Koji Ohara, Haruka Tamaru, Hirohisa Oda, Ippei Obayashi, Yasuyuki Hiraoka, Osami Sakata,
Abstract Understanding the liquid structure provides information that is crucial to uncovering the nature of the glass-liquid transition. We apply an aerodynamic levitation technique and high-energy X-rays to liquid ( l )-Er 2 O 3 to discover its structure. The sample densities are measured by electrostatic levitation at the International Space Station. Liquid Er 2 O 3 displays a very sharp diffraction peak (principal peak). Applying a combined reverse Monte Carlo – molecular dynamics approach, the simulations ...
Tópico(s): Mineralogy and Gemology Studies
2020 - Nature Portfolio | NPG Asia Materials
Shintaro Kajiyama, Yang Wu, Masayuki Hyodo, Yukio Nakata, Koji Nakashima, Norimasa Yoshimoto,
A series of triaxial compression tests were performed on the methane hydrate-bearing sands formed with rounded glass beads and natural sands to examine their mechanical properties. The effect of particle characteristics on the mechanical response of methane hydrate-bearing sands with regard to the exertion of bonding force and de-bond mechanism between grains is explained from the grain-scale viewpoint. In comparison with the natural sand, methane hydrate-bearing glass beads owns a similar initial ...
Tópico(s): Climate change and permafrost
2017 - Elsevier BV | Journal of Natural Gas Science and Engineering
Tomohisa Nagata, Akinori Nakata, Koji Mori, Takashi Maruyama, Futoshi Kawashita, Masako Nagata,
A number of companies publish corporate social responsibility (CSR) reporting in booklets and other publicly available formats. The purpose of this paper is to clarify the nine-year (2004-2012) trend of occupational safety and health (OSH) activities as described in CSR reporting (by industry sector and company size).We investigated CSR reporting on the website in all Japanese companies listed on the first section of the Tokyo Stock Exchange. The data were extracted from CSR reporting of each company ...
Tópico(s): Risk Perception and Management
2017 - BioMed Central | BMC Public Health
H. Shiraga, Shinsuke Fujioka, M. Nakai, T. Watari, Hirotaka Nakamura, Yasunobu Arikawa, H. Hosoda, Takahiro Nagai, Mayuko Koga, Hironobu Kikuchi, Yoshikazu Ishii, T. Sogo, K. Shigemori, H. Nishimura, Zhe Zhang, Minoru Tanabe, S. Ohira, Yoshitaka Fujii, Tomohiro Namimoto, Y. Sakawa, O. Maegawa, T. Ozaki, K. A. Tanaka, H. Habara, T. Iwawaki, Kozo Shimada, Hideo Nagatomo, T. Johzaki, Atsushi Sunahara, M. Murakami, H. Sakagami, T. Taguchi, T. Norimatsu, H. Homma, Yasushi Fujimoto, A. Iwamoto, N. Miyanaga, Junji Kawanaka, Takahisa Jitsuno, Yoshiki Nakata, Koji Tsubakimoto, Keiichi Sueda, N. Morio, S. Matsuo, T. Kawasaki, K. Sawai, K. Tsuji, Hironaru Murakami, T. Kanabe, K. Kondo, R. Kodama, Nobuhiko Sarukura, Toshihiko Shimizu, K. Mima, H. Azechi,
Abstract Implosion and heating experiments at the Institute of Laser Engineering, Osaka University on Fast Ignition (FI) targets for the FIREX-1 project have been performed with Gekko-XII laser for implosions and LFEX laser for heating. We tried to reduce the prepulse level in the LFEX laser system and have improved the plasma diagnostics to observe the plasma in the harsh hard X-ray environment. A plastic (CD) shell target, 7-μm thick and 500 μm in diameter with a hollow gold cone was used in this ...
Tópico(s): Laser-induced spectroscopy and plasma
2012 - Elsevier BV | High Energy Density Physics
H. Shiraga, Shinsuke Fujioka, M. Nakai, T. Watari, Hideya Nakamura, Yasunobu Arikawa, H. Hosoda, Takahiro Nagai, Mayuko Koga, Hironobu Kikuchi, Yoshikazu Ishii, T. Sogo, K. Shigemori, H. Nishimura, Zhe Zhang, Minoru Tanabe, S. Ohira, Yoshitaka Fujii, Tomohiro Namimoto, Y. Sakawa, O. Maegawa, T. Ozaki, K. A. Tanaka, H. Habara, T. Iwawaki, Kozo Shimada, Hideo Nagatomo, T. Johzaki, Atsushi Sunahara, M. Murakami, H. Sakagami, T. Taguchi, T. Norimatsu, H. Homma, Yasushi Fujimoto, A. Iwamoto, N. Miyanaga, Junji Kawanaka, Takahisa Jitsuno, Yoshiki Nakata, Koji Tsubakimoto, N. Morio, T. Kawasaki, K. Sawai, K. Tsuji, Hironaru Murakami, T. Kanabe, K. Kondo, Nobuhiko Sarukura, Toshihiko Shimizu, K. Mima, H. Azechi,
Based on the successful result of fast heating of a shell target with a cone for heating beam injection at Osaka University in 2002 using the PW laser (Kodama et al 2002 Nature 418 933), the FIREX-1 project was started in 2004. Its goal is to demonstrate fuel heating up to 5 keV using an upgraded heating laser beam. For this purpose, the LFEX laser, which can deliver an energy up to10 kJ in a 0.5–20 ps pulse at its full spec, has been constructed in addition to the Gekko-XII laser system at the Institute ...
Tópico(s): Laser-induced spectroscopy and plasma
2011 - IOP Publishing | Plasma Physics and Controlled Fusion
Takanori Okada, Kazufumi Ooi, Yosuke Nakata, Koji Fujita, Katsuhisa Tanaka, Kōichiro Tanaka,
We investigate the surface electromagnetic characteristics of a photoinduced periodical structure using the attenuated total reflection (ATR) technique in the terahertz frequency region. A wire grating structure is generated at the surface of a silicon prism by irradiation with a spatially modulated, ultrafast pulsed laser. A characteristic minimum due to the excitation of surface waves is observed in the ATR spectrum. The depth profile of the photoinduced carrier layer is also studied. We confirm ...
Tópico(s): Metamaterials and Metasurfaces Applications
2010 - Optica Publishing Group | Optics Letters
With the density-matrix variational method, the ground-state energy of a many-electron system is calculated by minimizing the energy expectation value subject to the selected representability conditions for the second-order reduced-density matrix (2-RDM). There is a lack of size extensivity under the $P$, $Q$, and $G$ conditions of this method by applying to $M$ noninteracting atoms and molecules up to $M=32$; ${\text{Be}}_{M}$, ${({\text{CH}}_{4})}_{M}$, and ${({\text{N}}_{2})}_{M}$. The energy per molecule $(E/M)$ ...
Tópico(s): Advanced NMR Techniques and Applications
2009 - American Physical Society | Physical Review A
K. Yamamoto, Manabu Tanaka, Shinichi Tashiro, Kazuya Nakata, Koji Yamazaki, Eri Yamamoto, Keiichi Suzuki, Anthony B. Murphy,
A gas tungsten arc in helium and argon was modelled taking into account the contamination of the plasma by metal vapour from the weld pool. The whole region of gas tungsten arc atmosphere including the tungsten cathode, arc plasma and weld pool was treated using a unified numerical model. A viscosity approximation was used to express the diffusion coefficient in terms of viscosity of shielding gas and metal vapour. The transient two-dimensional distributions of the temperature, velocity of plasma ...
Tópico(s): Metal and Thin Film Mechanics
2008 - Maney Publishing | Science and Technology of Welding & Joining
Kentaro Yamamoto, Manabu Tanaka, Shinichi Tashiro, Kohei Nakata, Koji Yamazaki, Eri Yamamoto, Keiichi Suzuki, Anthony B. Murphy,
A gas tungsten arc in helium is modeled taking into account the contamination of the plasma by the metal vapor from the weld pool surface. The whole region of gas tungsten arc welding, namely the tungsten cathode, arc plasma and weld pool, is treated using a unified numerical model. A viscosity approximation is used to express the diffusion coefficient in terms of the viscosities of the helium gas and the iron vapor. The time-dependent two-dimensional distributions of temperature, velocity and iron ...
Tópico(s): Advanced materials and composites
2008 - Elsevier BV | Surface and Coatings Technology
Hiroki Nakata, Koji Inui, Toshiaki Wasaka, Yohei Tamura, Kosuke Akatsuka, Tetsuo Kida, Ryusuke Kakigi,
We investigated the effect of the inhibitory process with increasing muscle force on event-related potentials (ERPs) and motor evoked potentials (MEPs). The subjects performed a S1–S2 paradigm with go/nogo tasks. S1 was an auditory tone burst, and S2 was an electrical stimulation applied to the second (go stimuli) or fifth digit (nogo stimuli) of the left hand. The recordings were conducted at 3 force levels; 10, 30 and 50% maximal voluntary contraction (MVC). After the presentation of S2, the subjects ...
Tópico(s): Muscle activation and electromyography studies
2006 - Elsevier BV | Clinical Neurophysiology
Ryusuke Kakigi, Hiroki Nakata, Koji Inui, Nobuo Hiroe, Osamu Nagata, Manabu Honda, Satoshi Tanaka, Norihiro Sadato, Mitsumasa Kawakami,
We recorded magnetoencephalography (MEG) and functional magnetic resonance imaging (fMRI) following noxious laser stimulation in a Yoga Master who claims not to feel pain when meditating. As for background MEG activity, the power of alpha frequency bands peaking at around 10 Hz was much increased during meditation over occipital, parietal and temporal regions, when compared with the non-meditative state, which might mean the subject was very relaxed, though he did not fall asleep, during meditation. ...
Tópico(s): Psychosomatic Disorders and Their Treatments
2005 - Wiley | European Journal of Pain
Hiroki Nakata, Koji Inui, Toshiaki Wasaka, Kosuke Akatsuka, Ryusuke Kakigi,
The go/nogo task is a useful paradigm for recording event-related potentials (ERPs) to investigate the neural mechanisms of response inhibition. In nogo trials, a negative deflection at around 140-300 ms (N2), which has been called the 'nogo potential', is elicited at the frontocentral electrodes, compared with ERPs recorded in go trials. In the present study, we investigated the generators of nogo potentials by recording ERPs and by using magnetoencephalography (MEG) simultaneously during somatosensory ...
Tópico(s): EEG and Brain-Computer Interfaces
2005 - Wiley | European Journal of Neuroscience
Kosuke Akatsuka, Toshiaki Wasaka, Hiroki Nakata, Koji Inui, Minoru Hoshiyama, Ryusuke Kakigi,
To determine the existence of a preattentively evoked somatosensory mismatch negativity component and to investigate the use of that component in objective clinical diagnostics. First we determined the temporal discrimination threshold (DT) of paired stimuli in each subject, and applied two sequential electrical stimuli to the hand with paired stimulus times of (1) DT−10 ms, (2) DT−30 ms and (3) DT+50 ms. Then, we recorded ERPs using an oddball paradigm, frequent (standard) and rare (deviant). We used ...
Tópico(s): Hearing Loss and Rehabilitation
2005 - Elsevier BV | Clinical Neurophysiology
Hiroki Nakata, Koji Inui, Toshiaki Wasaka, Yohei Tamura, Tetsuo Kida, Ryusuke Kakigi,
Tópico(s): EEG and Brain-Computer Interfaces
2004 - Springer Science+Business Media | Experimental Brain Research
Hiroki Nakata, Koji Inui, Toshiaki Wasaka, Yoshiaki Nishihira, Ryusuke Kakigi,
Tópico(s): Tactile and Sensory Interactions
2003 - Springer Science+Business Media | Brain Topography
Hiroki Nakata, Koji Inui, Yoshiaki Nishihira, Arihiro Hatta, Masanori Sakamoto, Tetsuo Kida, Toshiaki Wasaka, Ryusuke Kakigi,
Objective: We investigated the effects of a go/nogo task on event-related potentials (ERPs) evoked by somatosensory stimuli. Methods: ERPs following electrical stimulation of the second (go stimulus) or fifth (nogo stimulus) left-handed digit were recorded from 9 subjects. The recordings were conducted in 3 conditions: Control, Count and Movement. The subjects were instructed to count the go stimuli silently in Count, and respond to the go stimuli by grasping right hands in Movement. Go and nogo stimuli ...
Tópico(s): Motor Control and Adaptation
2003 - Elsevier BV | Clinical Neurophysiology
Hiroki Nakata, Koji Inui, Toshiaki Wasaka, Yohei Tamura, Tuan Diep Tran, Yunhai Qiu, Xiaohong Wang, Thi Binh Nguyen, Ryusuke Kakigi,
To evaluate the effects of movement on cortical activities evoked by noxious stimulation, we recorded magnetoencephalography following noxious YAG laser stimulation applied to the dorsum of the left hand in normal volunteers. Results of the present study can be summarized as follows: (1) active movement of the hand ipsilateral to the side of noxious stimulation resulted in significant attenuation of both primary and secondary somatosensory cortices (SI and SII) in the hemisphere contralateral to the ...
Tópico(s): Pain Mechanisms and Treatments
2003 - Lippincott Williams & Wilkins | Pain
Aya Nakata, Koji Ogawa, Takashi Sasaki, N. Koyama, Ken Wada, Jun Kotera, Hideo Kikkawa, Kenji Omori, Osamu Kaminuma,
SUMMARY Even though the existence of phosphodiesterase (PDE) 7 in T cells has been proved, the lack of a selective PDE7 inhibitor has confounded an accurate assessment of PDE7 function in such cells. In order to elucidate the role of PDE7 in human T cell function, the effects of two PDE inhibitors on PDE7A activity, cytokine synthesis, proliferation and CD25 expression of human peripheral blood mononuclear cells (PBMC) were determined. Recombinant human PDE7A was obtained and subjected to cyclic AMP- ...
Tópico(s): Receptor Mechanisms and Signaling
2002 - Oxford University Press | Clinical & Experimental Immunology
Kohki Mukai, Yoshiaki Nakata, Koji Otsubo, Mitsuru Sugawara, Naoki Yokoyama, Hiroshi Ishikawa,
This letter reports on the high characteristic temperature of InGaAs/GaAs quantum-dot lasers at room temperature. Self-assembled quantum dots were grown using low-growth-rate molecularbeam epitaxy, and continuous-wave lasing occurred at the dot ground level of 1.26 μm at 25 °C. The characteristic temperature of the threshold currents was 120 K, and ground-level lasing was observed up to 100 °C. Comparing the lasing performances and the spontaneous emission spectra with those of 1.3 μm emission dots, ...
Tópico(s): Photonic and Optical Devices
2000 - American Institute of Physics | Applied Physics Letters
Hideto Watanabe, Ken Nakata, Koji Kimata, Isao Nakanishi, Yoshihiko Yamada,
Mouse cartilage matrix deficiency ( cmd ) is an autosomal recessive disorder caused by a genetic defect of aggrecan, a large chondroitin sulfate proteoglycan in cartilage. The homozygotes (−/−) are characterized by cleft palate and short limbs, tail, and snout. They die just after birth because of respiratory failure, and the heterozygotes (+/−) appear normal at birth. Here we report that the heterozygotes show dwarfism and develop spinal misalignment with age. Within 19 months of age, they exhibit spastic gait ...
Tópico(s): Protease and Inhibitor Mechanisms
1997 - National Academy of Sciences | Proceedings of the National Academy of Sciences
N. Takahashi, T. Nakata, Koji Fujiwara, Tamaki Imai,
The effectiveness of the edge element is investigated by comparing systematically the number of unknown variables with that of the nodal element. It is shown that the edge element is superior to the nodal element from the standpoints of computer storage and CPU time. The 3-D periodic boundary condition for the edge element is also derived in order to reduce the computer storage and the CPU time. >
Tópico(s): Advanced Numerical Methods in Computational Mathematics
1992 - IEEE Magnetics Society | IEEE Transactions on Magnetics
David Simoncini, Hiroya Nakata, Koji Ogata, Shinichiro Nakamura, Kam Y. J. Zhang,
Abstract Protein structure prediction directly from sequences is a very challenging problem in computational biology. One of the most successful approaches employs stochastic conformational sampling to search an empirically derived energy function landscape for the global energy minimum state. Due to the errors in the empirically derived energy function, the lowest energy conformation may not be the best model. We have evaluated the use of energy calculated by the fragment molecular orbital method ( ...
Tópico(s): Computational Drug Discovery Methods
2015 - Wiley | Molecular Informatics
Seiji Yaegassi, Masaya Okada, Yuu Saitou, Mitsunori Yokoyama, Ken Nakata, Koji Katayama, Masaki Ueno, Makoto Kiyama, Tsukuru Katsuyama, Takao Nakamura,
Abstract Vertical heterojunction field‐effect transistors (VHFETs) utilizing re‐grown AlGaN/GaN two‐dimensional electron gas (2DEG) channels on free‐standing GaN substrates have been developed. The VHFETs exhibited a specific on‐resistance (RonA) of 7.6 mΩcm 2 at a threshold voltage (V th ) of ‐1.1 V and a breakdown voltage (VB) of 672 V. The breakdown voltage and the figure of merit (VB 2 /RonA) are the highest among those of the GaN‐based vertical transistors ever reported. It was demonstrated that the ...
Tópico(s): Semiconductor materials and devices
2010 - Wiley | Physica status solidi. C, Conferences and critical reviews/Physica status solidi. C, Current topics in solid state physics
Kiwako Sakamoto, Hiroki Nakata, Koji Inui, Mauro Gianni Perrucci, Cosimo Del Gratta, Ryusuke Kakigi, Gian Luca Romani,
The somatic sensation of the tongue is necessary for daily life, but it is difficult to know the underlying neural mechanisms. In particular, because of the vomiting reflex and several morphological problems, no neuroimaging studies have examined somatosensory processing by stimulating the posterior part of the tongue, except for two magnetoencephalographic studies (Sakamoto et al., 2008a,b). This is the first study to clarify the human cortical processing for sensory perception by the posterior ...
Tópico(s): Motor Control and Adaptation
2009 - Elsevier BV | Neuroscience Research