HIGH POWER REVERSE CONDUCTION GTO THYRISTORS

Yoshikazu Takahashi,Masahide Watanabe,Osamu Yamada,Humiaki Kirihata,Osamu Hashimoto 전력전자학회 1989 ICPE(ISPE)논문집 Vol.- No.-

We have newly developed two types of reverse conducting GTO(RC-GTO)thynstors with ratings of 2.5kV,2000A and t. 5kV,3000A. Good electrical separation between the GTO part and the diode part was attained by introducing a double diffused p-base profile. High turn-off capability was achieved by reducing the variation of on-state voltage and gate impedance among the GTO segments.<br/> Especially for the 4.5kV, 3000A device, a pin Junction structure with anode shorting was applied in order to reduce on-state voltage and switching energy.

Institutionalization of Environmental Education in Japan

Masahiro Takahashi,Osamu Abe 한국환경교육학회 2019 環境 敎育 Vol.32 No.4

In this paper, the historical process of institutionalization of environmental education will be addressed as central ideas on how to attain environmental conservation and a sustainable society in Japan. In order to clarify the figure of Japanese environmental education, an institutionalization process and some important topics related to environmental education will also be described. Primitive environmental education had occurred when miserable pollution covered in Japan. Historically it was called Kowgai education (pollution education), which was one of the educational movements. After the experience of Kowgai Education, Japanese environmental education showed discontinuation between before the 1990s and after the 1990s. It is one of the important characters when to see overall environmental education in Japan. Environmental education in Japan prior to the 1990s focused on nature and environmental problems. However, since the 1990s when global environmental problems emerged, environmental education in Japan has been continuously developed. The concept of ESD is included in the idea of environmental education when the Revised Basic Act on Education appeared in 2006. Recently, Environmental Education Promotion Law is enacted in 2011 and it is also contained the concept of ESD. Terminology issue is identified in these days, which means several terms are disordered in this field of environmental education in Japan, such as "Environmental Education" and "ESD" are both utilized various sentence and contents.

Evolution of Visual Pigments and Related Molecules

Hisatomi, Osamu,Yamamoto, Shintaro,Kobayashi, Yuko,Honkawa, Hanayo,Takahashi, Yusuke,Tokunaga, Fumio Korean Society of Photoscience 2002 Journal of Photosciences Vol.9 No.2

In photoreceptor cells, light activates visual pigments consisting of a chromophore (retinal) and a protein moiety (opsin). Activated visual pigments trigger an enzymatic cascade, called phototransduction cascade, in which more than ten phototransduction proteins are participating. Two types of vertebrate photoreceptor cells, rods and cones, play roles in twilight and daylight vision, respectively. Cones are further classified into several subtypes based on their morphology and spectral sensitivity. Though the diversities of vertebrate photoreceptor cells are crucial for color discrimination and detection of light over a wider range of intensities, the molecular mechanism to characterize the photoreceptor types remains unclear. We investigated the amino acid sequences of about 50 vertebrate opsins, and found that these sequences can be classified into five fundamental subfamilies. Clear relationships were found between these subfamilies and their characteristic spectral sensitivities. In addition to opsins, we studied other phototransduction proteins. The amino acid sequences of phototransduction proteins can be classified into a few subfamilies. Even though their spectral sensitivity is considerably different, cones fundamentally share the phototransduction protein isoforms which are different from those found in rods. It is suggested that the difference in phototransduction proteins between rods and cones is responsible for their sensitivity to light. Isoforms and their selective expression may characterize individual photoreceptor cells, thus providing us with physiological functions such as color vision and daylight/twilight visions.

Magnified single-balloon enteroscopy in the diagnosis of intestinal follicular lymphoma: a case series

( Kenichiro Takahashi ),( Shigeki Bamba ),( Masahiro Kawahara ),( Atsushi Nishida ),( Osamu Inatomi ),( Masaya Sasaki ),( Tomoyuki Tsujikawa ),( Ryoji Kushima ),( Mitsushige Sugimoto ),( Katsuyuki Kit 대한장연구학회 2018 Intestinal Research Vol.16 No.4

The objective of this study was to evaluate the magnified endoscopic findings in the diagnosis of follicular lymphoma in the small intestine in comparison with those of intestinal follicular lymphoma and lymphangiectasia. Four patients with follicular lymphoma and 3 with lymphangiectasia in the small intestine were retrospectively analyzed. A prototype magnifying single-balloon enteroscope was used. The findings of the intestinal follicular lymphoma and lymphangiectasia were retrospectively analyzed to determine the magnified endoscopic findings of follicular lymphoma in the small intestine. Opaque white granules were observed in 3 of the 4 patients with follicular lymphoma. Magnified narrow-band imaging (NBI) of the opaque white granules showed stretched microvessels, which had a diminutive tree-like appearance. The remaining patient had no opaque white granules and only displayed whitish villi. Magnified NBI observation of the whitish villi revealed the absence of marginal villus epithelium, which was confirmed by histology. The magnified NBI enteroscopy revealed the diminutive tree-like appearance on the opaque white granules and the absence of marginal villus epithelium of the whitish villi in intestinal follicular lymphoma. These findings may be useful in diagnosing follicular lymphoma. (Intest Res 2018;16:628-634)

Effects of Geometrical Uncertainties on Whole Breast Radiotherapy: A Comparison of Four Different Techniques

Naoki Nakamura,Osamu Takahashi,Minobu Kamo,Shogo Hatanaka,Haruna Endo,Norifumi Mizuno,Naoto Shikama,Mami Ogita,Kenji Sekiguchi 한국유방암학회 2014 Journal of breast cancer Vol.17 No.2

Purpose: The purpose of this study was to quantify the targetcoverage, homogeneity, and robustness of the dose distributionsagainst geometrical uncertainties associated with fourwhole breast radiotherapy techniques. Methods: The study wasbased on the planning-computed tomography-datasets of 20patients who underwent whole breast radiotherapy. A total offour treatment plans (wedge, field-in-field [FIF], hybrid intensitymodulatedradiotherapy [IMRT], and full IMRT) were created foreach patient. The hybrid IMRT plans comprised two opposedtangential open beams plus two IMRT beams. Setup errors weresimulated by moving the beam isocenters by 5 mm in the anterioror posterior direction. Results: With the original plan, thewedge technique yielded a high volume receiving ≥107% of theprescription dose (V107; 7.5%±4.2%), whereas the other threetechniques yielded excellent target coverage and homogeneity. A 5 mm anterior displacement caused a large and significant increasein the V107 (+5.2%±4.1%, p<0.01) with the FIF plan, butnot with the hybrid IMRT (+0.4%±1.2%, p=0.11) or full IMRT(+0.7%±1.8%, p=0.10) plan. A 5-mm posterior displacementcaused a large decrease in the V95 with the hybrid IMRT (-2.5%±3.7%, p<0.01) and full IMRT (-4.3%±5.1%, p<0.01) plans, butnot with the FIF plan (+0.1%±0.7%, p=0.74). The decrease inV95 was significantly smaller with the hybrid IMRT plan than withthe full IMRT plan (p<0.01). Conclusion: The FIF, hybrid IMRT,and full IMRT plans offered excellent target coverage and homogeneity. Hybrid IMRT provided better robustness against geometricaluncertainties than full IMRT, whereas FIF provided comparablerobustness to that of hybrid IMRT

Relationship between the gut microbiota and bile acid composition in the ileal mucosa of Crohn’s disease

Shigeki Bamba,Osamu Inatomi,Atsushi Nishida,Masashi Ohno,Takayuki Imai,Kenichiro Takahashi,Yuji Naito,Junichi Iwamoto,Akira Honda,Naohiro Inohara,Akira Andoh 대한장연구학회 2022 Intestinal Research Vol.20 No.3

Background/Aims: Crosstalk between the gut microbiota and bile acid plays an important role in the pathogenesis of gastrointestinal disorders. We investigated the relationship between microbial structure and bile acid metabolism in the ileal mucosa of Crohn’s disease (CD).Methods: Twelve non-CD controls and 38 CD patients in clinical remission were enrolled. Samples were collected from the distal ileum under balloon-assisted enteroscopy. Bile acid composition was analyzed by liquid chromatography-mass spectrometry. The gut microbiota was analyzed by 16S rRNA gene sequencing.Results: The Shannon evenness index was significantly lower in endoscopically active lesions than in non-CD controls. β-Diversity, evaluated by the UniFrac metric, revealed a significant difference between the active lesions and non-CD controls (<i>P</i>=0.039). The relative abundance of <i>Escherichia</i> was significantly higher and that of <i>Faecalibacterium</i> and <i>Roseburia</i> was significantly lower in CD samples than in non-CD controls. The increased abundance of <i>Escherichia</i> was more prominent in active lesions than in inactive lesions. The proportion of conjugated bile acids was significantly higher in CD patients than in non-CD controls, but there was no difference in the proportion of primary or secondary bile acids. The genera <i>Escherichia</i> and <i>Lactobacillus</i> were positively correlated with the proportion of conjugated bile acids. On the other hand, <i>Roseburia</i>, <i>Intestinibacter</i>, and <i>Faecalibacterium</i> were negatively correlated with the proportion of conjugated bile acids.Conclusions: Mucosa-associated dysbiosis and the alteration of bile acid composition were identified in the ileum of CD patients. These may play a role in the pathophysiology of ileal lesions in CD patients.

INTEGRATING MULTIMEDIA APPLICATIONS ON HIGH-SPEED NETWORK

Teruji Shiroshita,Osamu Takahashi,Masahide Yamashita 한국통신학회 1995 Asia-Pacific Conference on Communications Vol.1 No.1

Realization of Complex Wave Digital Filters with Generalized-Immittance Converter

Masataka Osada,Osamu Yamazaki,Shinichi Takahashi 대한전자공학회 1995 JTC-CSCC : Joint Technical Conference on Circuits Vol.- No.-

Insulin-like Growth Factor-Ⅰand Ⅱ Induce An Increase in the Translational Activity of Amelogenin in the Mouse Embryonic First Molar In Vitro

Yamane, Akira,takahashi, Katsu,Bringas, Pablo,Amano, Osamu,Slavkin, Harold C.,Margarita, Zeichner-David Korean Academy of Oral Biology and the UCLA Dental 1997 International Journal of Oral Biology Vol.22 No.3

In order to elucidate the roles of insulin, IGF-Ⅰ and Ⅱ during amelogenesis, the effects of these factors on the translational activity of amelogenin, the predominant matrix protein in developing enamel, were examined in mouse embryonic molars maintained in vitro. Mouse mandibular first molars isolated from embryos on embryonic day 15 were cultured as an explant for 6, 12 and 18 days in serumless, chemically defined medium containing 1000ng/ml of insulin, 100ng/ml of IGF-Ⅰ or 100ng/ml of IGF-Ⅱ. The translational activity of amelogenin was measured by incorporation of [^35S]-methionine, immunoprecipitation with a specific amelogenin antibody followed by polyacrylamide gel electrophoresis in combination with fluorography. IGF-Ⅰ and IGF-Ⅱ induced 55% and 104% increases in the translational activity of amelogenin respectively at 6 days in culture. This effect was lost after 12 and 18 days in culture. Insulin did not produce any significant differences in the translational activity of amelogenin. These data suggested that IGF-Ⅰ and Ⅱ accelerated amelogenesis by inducing an increase in amelogenin translation in the mouse mandibular first molar in vitro.

Prototype single-balloon enteroscopy with passive bending and high force transmission improves depth of insertion in the small intestine

( Yasuhiro Morita ),( Shigeki Bamba ),( Osamu Inatomi ),( Kenichiro Takahashi ),( Takayuki Imai ),( Masaki Murata ),( Masashi Ohno ),( Masaya Sasaki ),( Tomoyuki Tsujikawa ),( Akira Andoh ) 대한장연구학회 2020 Intestinal Research Vol.18 No.2

Background/Aims: We retrospectively analyzed Crohn’s disease (CD) patients with small intestinal strictures who underwent single-balloon enteroscopy (SBE) to ascertain whether prototype SBEs with a passive bending mechanism and high force transmission insertion tube had better insertability in the small intestine than a conventional SBE. Methods: Among 253 CD patients who underwent SBE, we identified 94 CD patients who had undergone attempted endoscopic balloon dilatation (EBD) for small intestinal stenosis for inclusion in this study. We analyzed whether the type of scope used for their initial procedure affected the cumulative surgery-free rate. For the insertability analysis, patients who underwent SBE at least twice were divided into 3 groups according to the type of scope used: conventional SBE only, prototype SBE only, and both conventional and prototype SBEs. For each group, depth of insertion, procedure time, and number of EBDs were compared in the same patient at different time points. Results: The success rate of EBD was 88.3%. The 5- and 10-year cumulative surgery-free rate was 75.7% and 72.8%, respectively. Cox regression analysis indicated that the factors contributing to surgery were long stricture (≥2 cm), EBD failure, and elevated Crohn’s Disease Activity Index, but not the type of scope used for EBD. The prototype SBEs significantly improved the depth of insertion (P=0.03, Wilcoxon’s signed-rank test). Conclusions: In CD patients with small intestinal stenosis, the prototype SBEs with a passive bending mechanism and high force transmission insertion tube did not improve long-term EBD outcome but did improve deep insertability. (Clinical Trial Registration No. UMIN000037102) (Intest Res 2020;18:229-237)