M. Ochiai, M. Akita, Yutaka Ohno, Shigeru Kishimoto, Kouichi Maezawa, Takashi Mizutani,
AlGaN/GaN metal-insulator-semiconductor high-electron-mobility transistors (MIS-HEMTs) using Si3N4 film as a gate insulator have been successfully fabricated. The gate leakage current decreased by about three orders of magnitude compared to that of the conventional AlGaN/GaN HEMTs without the Si3N4 gate insulator. The low-frequency noise of the MIS-HEMTs was smaller than that of the conventional HEMTs. Current collapse has also been suppressed in the MIS-HEMTs.
Tópico(s): Silicon Carbide Semiconductor Technologies
2003 - Institute of Physics | Japanese Journal of Applied Physics
Hirofumi Akita, Yutaka Takeda, Hiromitsu Hoshino, Hiroshi Wada, Shogo Kobayashi, Shigeru Marubashi, Hidetoshi Eguchi, Masahiro Tanemura, Masaki Mori, Yuichiro� Doki, Hiroaki Nagano,
Background The management of branch duct–type intraductal papillary mucinous neoplasms (IPMNs) remains controversial. This study aimed to elucidate the preoperative clinical factors that identify high-risk malignant transformation in branch duct–type IPMN. Methods We retrospectively evaluated 38 patients diagnosed with branch duct–type IPMN who underwent pancreatectomy, identifying different preoperative factors between adenoma (intraductal papillary mucinous adenoma [IPMA]) and carcinoma (intraductal ...
Tópico(s): Gallbladder and Bile Duct Disorders
2011 - Elsevier BV | The American Journal of Surgery
Atsuko Tomita, Ken‐ichi Shimizu, Kazúo Kato, Tomoki Akita, Yutaka Tai,
In a previous article (Catal. Commun. 2012, 17, 194), we reported that Pt/Fe-containing alumina catalysts pretreated with water could catalyze CO oxidation even below room temperature. To clarify the effect of the water pretreatment and the reaction mechanism of the novel catalytic system, in situ Fourier transform infrared (FT-IR), and X-ray absorption fine structure (XAFS) measurements during CO oxidation were conducted. From FT-IR measurements, it was revealed that the Pt surface of the catalyst ...
Tópico(s): Catalysts for Methane Reforming
2012 - American Chemical Society | The Journal of Physical Chemistry C
Masayuki Machida, Kiyoshi Asai, Motoaki Sano, Toshihiro Tanaka, Toshitaka Kumagai, Goro Terai, Ken-Ichi Kusumoto, Toshihide Arima, Osamu Akita, Yutaka Kashiwagi, Keietsu Abe, Katsuya Gomi, Hiroyuki Horiuchi, Katsuhiko Kitamoto, Tetsuo Kobayashi, Michio Takeuchi, David W. Denning, James E. Galagan, William C. Nierman, Jiujiang Yu, David B. Archer, Joan W. Bennett, Deepak Bhatnagar, Thomas E. Cleveland, Natalie D. Fedorova, Osamu Gotoh, Hiroshi Horikawa, Akira Hosoyama, Masayuki Ichinomiya, Rie Igarashi, Kazuhiro Iwashita, Praveen R. Juvvadi, Masashi Kato, Yumiko Kato, Taishin Kin, Akira Kokubun, Hiroshi Maéda, Noriko Maeyama, Jun-ichi Maruyama, Hideki Nagasaki, Tasuku Nakajima, Ken Oda, Kinya Okada, Ian T. Paulsen, Kazutoshi Sakamoto, Toshihiko Sawano, Mikio Takahashi, Kumiko Takase, Yasunobu Terabayashi, Jennifer R. Wortman, Osamu Yamada, Youhei Yamagata, Hideharu Anazawa, Yoji Hata, Yoshinao Koide, Takashi Komori, Yasuji Koyama, Toshitaka Minetoki, Sivasundaram Suharnan, Akimitsu Tanaka, Katsumi Isono, Satoru Kuhara, Naotake Ogasawara, Hisashi Kikuchi,
The genome of Aspergillus oryzae, a fungus important for the production of traditional fermented foods and beverages in Japan, has been sequenced. The ability to secrete large amounts of proteins and the development of a transformation system have facilitated the use of A. oryzae in modern biotechnology. Although both A. oryzae and Aspergillus flavus belong to the section Flavi of the subgenus Circumdati of Aspergillus, A. oryzae, unlike A. flavus, does not produce aflatoxin, and its long history ...
Tópico(s): Probiotics and Fermented Foods
2005 - Nature Portfolio | Nature
Takashi Mizutani, Hiroshi Makihara, M. Akita, Yutaka Ohno, Shigeru Kishimoto, K. Maezawa,
Frequency dispersion of the drain conductance was observed in AlGaN/GaN high electron mobility transistors (HEMTs). The transition frequency shifted to higher frequencies with increasing temperature. The activation energy for the change of the transition frequency was 0.47 eV, which was almost the same as that obtained by the measurement of the temperature dependence of the low-frequency noise.
Tópico(s): Semiconductor materials and devices
2003 - Institute of Physics | Japanese Journal of Applied Physics
Kotaro Akita, Yutaka Miyazawa,
Roots exhibit positive hydrotropism in response to soil moisture gradients in arid conditions. However, the mechanisms that regulate hydrotropism are yet to be elucidated. Ca2+ is involved in this response, but the molecular factors that interact with Ca2+ are currently unknown. To understand the role of Ca2+ in hydrotropism, as well as to identify proteins that are involved in this process, we examined the physiology of Arabidopsis thaliana seedlings cultured in Ca2+-free medium. Treatment with ...
Tópico(s): Plant Molecular Biology Research
2022 - Elsevier BV | Environmental and Experimental Botany
Mika Matsumori, Yutaka Shoji, Tsutomu Takahashi, Yasuko Shoji, Goro Takada,
... Department of Pediatrics, Akita University School of Medicine, Akita, JapanSearch for more papers by this authorYutaka Shoji, Yutaka Shoji Department of Pediatrics, Akita University School of ... Department of Pediatrics, Akita University School of Medicine, Akita, JapanSearch for more papers by this authorYutaka Shoji, Yutaka Shoji Department of Pediatrics, Akita University School of Medicine, Akita, JapanSearch for more ...
Tópico(s): ATP Synthase and ATPases Research
2005 - Wiley | Pediatrics International
Kei Kondo, Munetaka Akita, Takafumi Nakagawa, Yutaka Matsuo, Michito Yoshizawa,
Abstract Nanocarbons are synthetic carbon‐rich compounds with polyaromatic frameworks that have lately attracted attention as emerging functional materials. However, their extreme hydrophobicity and aggregation peculiarity, besides their shape and size diversities, precluded their study in solution, especially in “green” water. More convenient and general solubilizing methods of nanocarbon frameworks are required by using non‐covalent supramolecular interactions. Here we report a protocol for solubilizing ...
Tópico(s): Supramolecular Chemistry and Complexes
2015 - Wiley | Chemistry - A European Journal
Hirofumi Akita, Zhong Zheng, Yutaka Takeda, Chul Yong Kim, Nobuyoshi Kittaka, Shogo Kobayashi, Shigeru Marubashi, Ichiro Takemasa, Hiroaki Nagano, Keizo Dono, Shoji Nakamori, Morito Monden, Masaki Mori, Yuichiro� Doki, Gerold Bepler,
The identification of molecular markers, useful for therapeutic decisions in pancreatic cancer patients, is crucial for advances in disease management. Gemcitabine, although a cornerstone of current therapy, has limited efficacy. RRM1 is a key molecule for gemcitabine efficacy and is also involved in tumor progression. We determined in situ RRM1 and excision repair cross complementation group 1 (ERCC1) protein levels in 68 pancreatic cancer patients. All had R0 resections without preoperative therapy. ...
Tópico(s): Neuroendocrine Tumor Research Advances
2009 - Springer Nature | Oncogene
Hirofumi Akita, Hiroaki Nagano, Yutaka Takeda, Hidetoshi Eguchi, Hiroshi Wada, Shogo Kobayashi, Shigeru Marubashi, Masahiro Tanemura, Hidenori Takahashi, Hiroaki Ohigashi, Yasuhiko Tomita, Osamu Ishikawa, M. Mori, Yuichiro� Doki,
The identification of molecular markers useful for predicting prognosis in pancreatic cancer patients is crucial for advances in disease management. The epithelial cell adhesion molecule (Ep-CAM) is known to express in most epithelial malignancies and was reported as a tumor marker or a candidate of molecular targeting therapy. However, the clinical significance of Ep-CAM expression in pancreatic cancer is not well-known. We determined the difference of malignant potential between parental and Ep- ...
Tópico(s): Phagocytosis and Immune Regulation
2011 - Springer Nature | Oncogene
Hironaga Akita, Katsumi Doi, Yutaka Kawarabayasi, Toshihisa Ohshima,
Tópico(s): Polyamine Metabolism and Applications
2012 - Springer Science+Business Media | Biotechnology Letters
Kenichi Matsumoto, Takehiro Noda, Shogo Kobayashi, Yoshihiro Sakano, Yuki Yokota, Yoshifumi Iwagami, Daisaku Yamada, Yoshito Tomimaru, Hirofumi Akita, Kunihito Gotoh, Yutaka Takeda, Masahiro Tanemura, Koji Umeshita, Yuichiro� Doki, Hidetoshi Eguchi,
Glycolysis emerges as a new therapeutic target for malignancies. The inhibition of glycolytic activator, PFKFB3, repairs tumor endothelial cell function, and normalizing the tumor microenvironment. We aimed to investigate the significance of PFKFB3 in HCC, and the effects of the PFKFB3 inhibitor, PFK15, in HCC tumor cells and tumor endothelial cells. Double immunofluorescent staining of PFKFB3 and CD31 in HCC tissues revealed that high PFKFB3 expression in both tumor cells and tumor endothelial ...
Tópico(s): Angiogenesis and VEGF in Cancer
2020 - Elsevier BV | Cancer Letters
Kento Imajo, Hidenori Toyoda, Satoshi Yasuda, Yasuaki Suzuki, Katsutoshi Sugimoto, Hidekatsu Kuroda, Tomoyuki Akita, Junko Tanaka, Yutaka Yasui, Nobuharu Tamaki, Masayuki Kurosaki, Namiki Izumi, Atsushi Nakajima, Takashi Kumada,
Background & AimsUltrasound-guided attenuation parameter (UGAP) is recently developed for noninvasive evaluation of steatosis. However, reports on its usefulness in clinical practice are limited. This prospective multicenter study analyzed the diagnostic accuracy of grading steatosis with reference to magnetic resonance imaging–based proton density fat fraction (MRI-PDFF), a noninvasive method with high accuracy, in a large cohort.MethodsAltogether, 1010 patients with chronic liver disease who underwent ...
Tópico(s): Cardiovascular Function and Risk Factors
2021 - Elsevier BV | Clinical Gastroenterology and Hepatology
Yuki Yokota, Takehiro Noda, Yuichiro Okumura, Shogo Kobayashi, Yoshifumi Iwagami, Daisaku Yamada, Yoshito Tomimaru, Hirofumi Akita, Kunihito Gotoh, Yutaka Takeda, Masahiro Tanemura, Takashi Murakami, Koji Umeshita, Yuichiro� Doki, Hidetoshi Eguchi,
Hepatocellular carcinoma (HCC) is the second leading cause of cancer-related death. High recurrence rates after curative resection and the lack of specific biomarkers for intrahepatic metastases are major clinical problems. Recently, exosomal microRNAs (miRNAs) have been reported to have a role in the formation of the pre-metastatic niche and as promising biomarkers in patients with malignancy. Here we aimed to clarify the molecular mechanisms of intrahepatic metastasis and to identify a novel biomarker ...
Tópico(s): Cancer-related molecular mechanisms research
2021 - Wiley | Cancer Science
Yutaka Shoji, Tsutomu Takahashi, Yukiko Suzuki, Takashi Suzuki, Kazuo Komatsu, Hiyoshi Hirono, Yasuko Shoji, Takehiko Yokoyama, Hideyuki Kito, Goro Takada,
... Department of Pediatrics, Akita University School of Medicine, Akita, JapanSearch for more papers by this author Yutaka Shoji M.D., Corresponding Author Yutaka Shoji M.D. Department of Pediatrics, Akita University School of Medicine, Akita, JapanDepartment of Pediatrics, ...
Tópico(s): Childhood Cancer Survivors' Quality of Life
1998 - Wiley | Human Mutation
M. Oguri, Tsuneyuki Nakamura, Keita Tamanuki, Chisato Akita, Chika Kitaoka, Yutaka Saikawa, Masato Takahashi,
Recent studies have revealed that atherosclerosis progresses faster than expected in young adults with a history of Kawasaki disease. However, it is unclear as to when these arterial changes become measurable. In this study, we evaluated subclinical arterial stiffness in young children with a history of Kawasaki disease using two-dimensional ultrasound speckle tracking.A total of 75 children with a history of Kawasaki disease (mean age, 8.2 ± 2.8 years) and 50 healthy controls (mean age 8.3 ± 3.5 years) ...
Tópico(s): Cardiovascular Health and Disease Prevention
2013 - Cambridge University Press | Cardiology in the Young
Hidekatsu Kuroda, Takuma Oguri, Naohisa Kamiyama, Hidenori Toyoda, Satoshi Yasuda, Kento Imajo, Yasuaki Suzuki, Katsutoshi Sugimoto, Tomoyuki Akita, Junko Tanaka, Yutaka Yasui, Masayuki Kurosaki, Namiki Izumi, Atsushi Nakajima, Yudai Fujiwara, Tamami Abe, Keisuke Kakisaka, Takayuki Matsumoto, Takashi Kumada,
Background Because of the global increase in the incidence of nonalcoholic fatty liver disease, the development of noninvasive, widely available, and highly accurate methods for assessing hepatic steatosis is necessary. Purpose To evaluate the performance of models with different combinations of quantitative US parameters for their ability to predict at least 5% steatosis in patients with chronic liver disease (CLD) as defined using MRI proton density fat fraction (PDFF). Materials and Methods Patients ...
Tópico(s): Liver Disease and Transplantation
2023 - Radiological Society of North America | Radiology
Katsumi Togashi, Yutaka Akita, Isao NAKANE, Yasuyuki Shibata, Isamu Nakai,
Tópico(s): Insect-Plant Interactions and Control
1997 - Springer Science+Business Media | Applied Entomology and Zoology
Koji Hontani, Takahiro Tsuchikawa, Takaki Hiwasa, Toru Nakamura, Takashi Ueno, Toshihiro Kushibiki, Mizuna Takahashi, Kazuho Inoko, Hironobu Takano, Satoshi Takeuchi, Hirotoshi Dosaka‐Akita, Masaki Kuwatani, Naoya Sakamoto, Yutaka Hatanaka, Tomoko Mitsuhashi, Hideaki Shimada, Toshiaki Shichinohe, Satoshi Hirano,
... Hironobu Takano 1 , Satoshi Takeuchi 3 , Hirotoshi Dosaka-Akita 3 , Masaki Kuwatani 4 , Naoya Sakamoto 4 , Yutaka Hatanaka 5 , Tomoko Mitsuhashi 5 , Hideaki Shimada 6 , ...
Tópico(s): Lung Cancer Research Studies
2017 - Impact Journals LLC | Oncotarget
Koichi Tanaka, Hiroaki Waki, Yutaka Ido, Satoshi Akita, Yoshikazu Yoshida, Tamio Yoshida, T. Matsuo,
... JapanSearch for more papers by this authorYutaka Ido, Yutaka Ido Shimadzu Corporation, Nishinokyo-Kuwabaracho, Nakagyo-ku, Kyoto 604, JapanSearch for more papers by this authorSatoshi Akita, Satoshi Akita Shimadzu Corporation, Nishinokyo-Kuwabaracho, Nakagyo-ku, ... JapanSearch for more papers by this authorYutaka Ido, Yutaka Ido Shimadzu Corporation, Nishinokyo-Kuwabaracho, Nakagyo-ku, Kyoto 604, JapanSearch for more papers by this authorSatoshi Akita, Satoshi Akita Shimadzu Corporation, Nishinokyo-Kuwabaracho, Nakagyo-ku, ...
Tópico(s): Ion-surface interactions and analysis
1988 - Wiley | Rapid Communications in Mass Spectrometry
Masahiko Kubo, Kunihito Gotoh, Hidetoshi Eguchi, Shogo Kobayashi, Yoshifumi Iwagami, Yoshito Tomimaru, Hirofumi Akita, Tadafumi Asaoka, Takehiro Noda, Yutaka Takeda, Masahiro Tanemura, Masaki Mori, Yuichiro� Doki,
Tópico(s): Drug Transport and Resistance Mechanisms
2019 - Springer Science+Business Media | Annals of Surgical Oncology
Mitsuru Kinoshita, Shogo Kobayashi, Kunihito Gotoh, Masahiko Kubo, Kôji Hayashi, Yoshifumi Iwagami, Daisaku Yamada, Hirofumi Akita, Takehiro Noda, Tadafumi Asaoka, Yutaka Takeda, Masahiro Tanemura, Hidetoshi Eguchi, Shinya Urakawa, Kumiko Goto, Kayoko Maekawa, Hisashi Wada, Masaki Mori, Yuichiro� Doki,
Tópico(s): Chemokine receptors and signaling
2019 - Springer Science+Business Media | Digestive Diseases and Sciences
Tadafumi Asaoka, Shogo Kobayashi, Takehiko Hanaki, Yoshifumi Iwagami, Yoshito Tomimaru, Hirofumi Akita, Takehiro Noda, Kunihito Gotoh, Yutaka Takeda, Masahiro Tanemura, Yuichiro� Doki, Hidetoshi Eguchi,
Tópico(s): Peptidase Inhibition and Analysis
2020 - Springer Science+Business Media | Surgery Today
T. Mizutani, Yutaka Ohno, M. Akita, Shigeru Kishimoto, K. Maezawa,
Drain current collapse in AlGaN/GaN HEMTs has been studied in detail. Applying negative gate bias stress to the device caused a serious current collapse. Spatially resolved light illumination on the device combined with the measurement of series source and drain resistances revealed that the collapse was caused by the electrons trapped at the surface states between the gate and drain electrodes. Passivation of the device surface with Si3N4 film eliminated the current collapse.
Tópico(s): Advancements in Semiconductor Devices and Circuit Design
2002 - Wiley | physica status solidi (a)
Takeshi Nakao, Yutaka Ohno, M. Akita, Shigeru Kishimoto, K. Maezawa, Takashi Mizutani,
Electroluminescence (EL) in GaN high electron mobility transistors (HEMTs) biased at high drain-source voltages was investigated. The electroluminescence was observed at the drain edge where the high-field region is formed. This is quite different from the case of GaAs HEMTs where luminescence was observed at the gate edge. EL spectroscopy was also performed. The luminescence with the wavelength of visible to near-infrared light, the energy of which was less than the band gap energy, was observed ...
Tópico(s): Ga2O3 and related materials
2002 - Institute of Physics | Japanese Journal of Applied Physics
Yutaka Ohno, M. Akita, Shigeru Kishimoto, K. Maezawa, Takashi Mizutani,
Temperature distributions in AlGaN/GaN high-electron-mobility transistors under bias voltage have been measured by micro-Raman scattering spectroscopy. The temperature was estimated from the Raman shift of E2 phonons of GaN. The spatial and temperature resolutions are 1 µm and 10 K, respectively. When the power dissipation was 248 mW at a drain voltage of 40 V, the peak temperature of 443 K was observed at the gate edge on the drain side at the center of the channel. This position corresponds to ...
Tópico(s): Advancements in Semiconductor Devices and Circuit Design
2002 - Institute of Physics | Japanese Journal of Applied Physics
T. Mizutani, Yutaka Ohno, M. Akita, Shigeru Kishimoto, K. Maezawa,
Drain current collapse in AlGaN/GaN HEMTs has been studied systematically by applying bias stress to the device. The collapse was suppressed by light illumination with energy smaller than the bandgap. The position dependence of the light illumination and the measurement of series source and drain resistances revealed that the collapse was caused by the surface states between the gate and drain electrodes, which captured electrons injected from the gate. The current collapse was eliminated by the ...
Tópico(s): Silicon Carbide Semiconductor Technologies
2003 - Institute of Electrical and Electronics Engineers | IEEE Transactions on Electron Devices
Hiroki Shibutani, Yuzo Akita, Kotaro Yutaka, Satoshi Yamamoto, Yumie Matsui, Masahiro Yoshinaga, Masahiro Karakawa, Yasukiyo Mori,
Takotsubo cardiomyopathy (TC) is a cardiomyopathy that shows distinctive clinical conditions first described more than 20 years ago. Because clinical features of TC mimic those of anterior acute myocardial infarction (AMI), the differential diagnosis is important in selecting the appropriate treatment strategy in the acute phase. But it was difficult to differentiate those two diseases because the TC-like findings; such as the electrocardiogram (ECG) changes and left ventricular wall motion abnormality ...
Tópico(s): Cardiac Imaging and Diagnostics
2016 - BioMed Central | BMC Cardiovascular Disorders
Masahisa Jinushi, Tomoko Morita, Zhifang Xu, Ichiro Kinoshita, Hirotoshi Dosaka‐Akita, Hideo Yagita∥, Yutaka Kawakami,
Autophagy is a vital process controlling the lysosomal degradation of cellular organelles and thereby regulating tissue homeostasis in an environment-dependent fashion. Recent studies have unveiled the critical role of tumor cell-derived autophagy in regulating pro-tumor and anti-tumor processes depending on different stages and tumor microenvironments. However, the precise mechanism whereby autophagy regulates tumor progression remains largely unclear. Since myeloid cells contribute to tumor progression ...
Tópico(s): Mangiferin and Mango Extracts
2017 - Public Library of Science | PLoS ONE
Takeshi Ando, Eiichi Ohki, Yasutaka Nakashima, Yutaka Akita, Hiroshi Iijima, Osamu Tanaka, Masakatsu G. Fujie,
A split belt treadmill for gait rehabilitation was developed to improve the symmetry of the stance phase time of patients with stroke. The system, which increases the stance phase time of the affected leg and then realizes a well-balanced gait, is divided into two components. First, the stance phases of the sound and affected legs were measured and presented visually in real time to the patient and physical therapist as biofeedback. Second, using stance phase biofeedback, the physical therapist ...
Tópico(s): Muscle activation and electromyography studies
2012 - Fuji Technology Press Ltd. | Journal of Robotics and Mechatronics