Mechanism of Ischemic Mitral Regurgitation

Yutaka Otsuji,Masaaki Takeuchi,Ryuzo Sakata,Robert A. Levine,Chuwa Tei 한국심초음파학회 2008 Journal of Cardiovascular Imaging (J Cardiovasc Im Vol.16 No.1

Augmented leaflet tethering due to the outward displacement of the PMs with LV remodeling appears to be a basic mechanism for ischemic MR. Further, annular dilatation and LV dysfunction likely contribute to the development of MR in the presence of augmented tethering. PM dysfunction per se does not usually cause ischemic MR and may occasionally attenuate tethering and MR. The concept of PM dyssynchrony is important and further study to separate effects of PM dyssynchrony from other factors are required. Although surgical annuloplasty is often effective in reversing ischemic MR, the frequency of patients with persistent or recurrent ischemic MR after surgical ring annuloplasty even with advanced down sizing suggests the need for approaches to address tethering. Finally, leaflet tethering in patients with ischemic MR can vary within a single patient and between patients, indicating the multiple and individualized approaches may be required to correct ischemic MR in affected patients. Augmented leaflet tethering due to the outward displacement of the PMs with LV remodeling appears to be a basic mechanism for ischemic MR. Further, annular dilatation and LV dysfunction likely contribute to the development of MR in the presence of augmented tethering. PM dysfunction per se does not usually cause ischemic MR and may occasionally attenuate tethering and MR. The concept of PM dyssynchrony is important and further study to separate effects of PM dyssynchrony from other factors are required. Although surgical annuloplasty is often effective in reversing ischemic MR, the frequency of patients with persistent or recurrent ischemic MR after surgical ring annuloplasty even with advanced down sizing suggests the need for approaches to address tethering. Finally, leaflet tethering in patients with ischemic MR can vary within a single patient and between patients, indicating the multiple and individualized approaches may be required to correct ischemic MR in affected patients.

Formation and Cycloreversion of 2-Silacyclobuta[2.3]cyclophances via Photoinduced Electron Transfer

Mizuno, Kazuhiko,Nakanishi, Kazuhisa,Otsuji, Yoshio,Hayamizu, Tomoo,Maeda, Hajime,Adachi, Tomohiro,Ishida, Akito,Takamuku, Setsuo Korean Society of Photoscience 2003 Journal of Photosciences Vol.10 No.1

Irradiation of an acetonitrile solution containing dimethylbis(4-vinylphenylmethyl)silane 1a in the presence of 9,10-dicyanoanthracene leads to formation of the intramolecular photocycloadduct, 2-sila-cyclobuta[2.3]cyclophane(2a). In contrast, prolonged irradiation gave insoluble polymeric material. The photocycloreversion of 2a occurs efficiently (quantum yields exceeds unity) by use of redox-type photosensitization in the presence of magnesium perchlorate. The transient absorption spectra generated by pulse radiolysis and gamma-radiolysis show that the radical cation species generated from 1a is different from that arising from 2a.

Exploring Science Communication of Global Issue and Suggesting its Implication in Science Education: The Cases about Nuclear Energy of Korea and Japan

박영신,정운관,Hisashi Otsuji 한국지구과학회 2018 韓國地球科學會誌 Vol.39 No.5

The purpose of this study was to explore what kinds of science communication are ongoing in formal and informal settings for learning about nuclear energy, which is very important issue domestically and internationally. The researchers collected and analyzed data from science textbooks at elementary and middle school levels, from exhibitions in Y informal hall that belongs to one nuclear power plant, and from 40 bestselling books about nuclear energy in order to explore the kind of science communication. The same process was used to explore Japanese case so that we could compare the results with Korean cases and draw implications for enhancing science communication about nuclear energy. The science communication of nuclear energy in Korea included implicit and indirect content espoused in science textbooks; two opposite views displayed in bestselling books, and positive aspects mainly displayed in exhibition of information hall in nuclear power plant. It is suggested that both direct and explicit science communication along with the neutral viewpoints including positive and negative ones be provided for the public to form a good understanding of nuclear energy

Solution-processed Al₂O₃gate dielectrics for graphene field-effect transistors

Park, Goon-Ho,Kim, Kwan-Soo,Fukidome, Hirokazu,Suemitsu, Tetsuya,Otsuji, Taiichi,Cho, Won-Ju,Suemitsu, Maki Institute of Pure and Applied Physics 2016 Japanese Journal of Applied Physics Vol.55 No.9

<P>The performance of actual graphene FETs suffers significant degradation from that expected for pristine graphene, which can be partly attributed to the onset of defects and the doping of the graphene induced during the fabrication of gate dielectric layers. These effects are mainly due to high-temperature processes such as postdeposition annealing. Here, we propose a novel low-temperature method for the fabrication of gate dielectrics, which consists of the natural oxidation of an ultrathin Al layer and a sol-gel process with oxygen plasma treatment to form an Al2O3 layer. The method results in a significant reduction of defects and doping in graphene, and devices fabricated by this method show an intrinsic carrier mobility as high as 9100 cm(2) V-1 s(-1). (C) 2016 The Japan Society of Applied Physics</P>

Design of Novel Two-Stage Light Gas Gun Made of Polyethylene

Satoshi Iima,Yasuhiro Akahoshi,Takao Koura,Hiroto Nagai,Hiroshi Takakura,Yasutaka Otsuji 한국항공우주학회 2008 한국항공우주학회 학술발표회 논문집 Vol.- No.-

In order to conduct impact experiments at the hypervelocity more 10 ㎞/s, a four-stage light gas gun is developed. The four-stage light gas gun could obtain higher launching velocity than the conventional guns by launching a small-sized two-stage light gas gun by a large-sized two-stage light gas gun. For the design of the four-stage light gas gun, design optimization is necessary. especially for the lengths of the pump tube and launch tube of the small-sized two-stage light gas gun. In this study. we estimate the performance of the four-stage light gas gun experimentally and numerically.

Impact of Tumor Location on the Quality of Life of Patients Undergoing Total or Proximal Gastrectomy

Fujisaki Muneharu,Nomura Takashi,Yamashita Hiroharu,Uenosono Yoshikazu,Fukunaga Tetsu,Otsuji Eigo,Takahashi Masahiro,Matsumoto Hideo,Oshio Atsushi,Nakada Koji 대한위암학회 2022 Journal of gastric cancer Vol.22 No.3

Purpose Most studies have investigated the differences in postgastrectomy quality of life (QOL) based on the surgical procedure or reconstruction method adopted; only a few studies have compared QOL based on tumor location. This large-scale study aims to investigate the differences in QOL between patients with esophagogastric junction cancer (EGJC) and those with upper third gastric cancer (UGC) undergoing the same gastrectomy procedure to evaluate the impact of tumor location on postoperative QOL. Methods The Postgastrectomy Syndrome Assessment Scale-45 (PGSAS-45) questionnaire was distributed in 70 institutions to 2,364 patients who underwent gastrectomy for EGJC or UGC. A total of 1,909 patients were eligible for the study, and 1,744 patients who underwent total gastrectomy (TG) or proximal gastrectomy (PG) were selected for the final analysis. These patients were divided into EGJC and UGC groups; thereafter, the PGSAS-45 main outcome measures (MOMs) were compared between the two groups for each type of gastrectomy. Results Among the post-TG patients, only one MOM was significantly better in the UGC group than in the EGJC group. Conversely, among the post-PG patients, postoperative QOL was significantly better in 6 out of 19 MOMs in the UGC group than in the EGJC group. Conclusions Tumor location had a minimal effect on the postoperative QOL of post-TG patients, whereas among post-PG patients, there were definite differences in postoperative QOL between the two groups. It seems reasonable to conservatively estimate the benefits of PG in patients with EGJC compared to those in patients with UGC. Purpose Most studies have investigated the differences in postgastrectomy quality of life (QOL) based on the surgical procedure or reconstruction method adopted; only a few studies have compared QOL based on tumor location. This large-scale study aims to investigate the differences in QOL between patients with esophagogastric junction cancer (EGJC) and those with upper third gastric cancer (UGC) undergoing the same gastrectomy procedure to evaluate the impact of tumor location on postoperative QOL. Methods The Postgastrectomy Syndrome Assessment Scale-45 (PGSAS-45) questionnaire was distributed in 70 institutions to 2,364 patients who underwent gastrectomy for EGJC or UGC. A total of 1,909 patients were eligible for the study, and 1,744 patients who underwent total gastrectomy (TG) or proximal gastrectomy (PG) were selected for the final analysis. These patients were divided into EGJC and UGC groups; thereafter, the PGSAS-45 main outcome measures (MOMs) were compared between the two groups for each type of gastrectomy. Results Among the post-TG patients, only one MOM was significantly better in the UGC group than in the EGJC group. Conversely, among the post-PG patients, postoperative QOL was significantly better in 6 out of 19 MOMs in the UGC group than in the EGJC group. Conclusions Tumor location had a minimal effect on the postoperative QOL of post-TG patients, whereas among post-PG patients, there were definite differences in postoperative QOL between the two groups. It seems reasonable to conservatively estimate the benefits of PG in patients with EGJC compared to those in patients with UGC.

Differences in Prevalence of Lymphovascular Invasion among Early Gastric Cancers between Korea and Japan

( Sun-young Lee ),( Naohisa Yoshida ),( Osamu Dohi ),( Sang Pyo Lee ),( Daisuke Ichikawa ),( Jeong Hwan Kim ),( In-kyung Sung ),( Hyung Seok Park ),( Eigo Otsuji ),( Yoshito Itoh ),( Chan Sup Shim ),( 대한간학회 2017 Gut and Liver Vol.11 No.3

Background/Aims: The presence of invasion is a diagnostic criterion of early gastric cancer (EGC) in Korea, whereas diagnosis in Japan is based on enlarged nuclei and prominent nucleoli. Moreover, the depth of invasion is the location of cancer cell infiltration in Korea, whereas it is the location of lymphovascular invasion (LVI) or cancer cell infiltration in Japan. We evaluated the characteristics of EGC with LVI to uncover the effects of different diagnostic criteria. Methods: Consecutive T1-stage EGC patients who underwent complete resection were included after endoscopic or surgical resection. The presence of LVI was evaluated. Results: LVI was present in 112 of 1,089 T1-stage EGC patients. LVI was associated with depth of invasion (p<0.001) and age (p=0.017). The prevalence of LVI in mucosal cancer was significantly higher in Korea (p<0.001), whereas that of submucosal cancer was higher in Japan (p=0.024). For mucosal EGC types, LVI was positively correlated with diagnostic criteria applied in Korea (p=0.017). For submucosal EGC types, LVI was positively correlated with Japanese criteria (p=0.001) and old age (p=0.045). Conclusions: The higher prevalence of LVI for mucosal EGC in Korea and for submucosal EGC in Japan indicates that different diagnostic criteria should be considered when reading publications from other countries. (Gut Liver 2017;11:383-391)