Electron heating experiment using the high harmonic fast wave on LHD

hiroshi Kasahara,K. Saito,N. Takeuchi,R. Kumazawa,T. Seki,T. Mutoh,T. Oosako,Y. Takase 한국물리학회 2006 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.49 No.III

Electron heating experiments using the High Harmonic Fast Wave (HHFW) were performed on the Large Helical Device (LHD). An electron temperature increase from 2.5 keV to 3.6 keV by 1.2 MW of HHFW was observed when both ECH and NBI were used to create a target plasma with high stored energy and electron temperature. When ECH works effectively, the electron density is pumped out, but the rate of decrease of the electron density is reduced when HHFW heating is applied. This result indicates that HHFW is absorbed effectively when the central electron temperature and electron beta are high enough, and suggests that parallel heating of electrons by HHFW reduces electron density pump out caused by perpendicular electron heating by ECH. According to a 1-D calculation, raising the density is more effective for improving singlepass damping than raising the temperature. According to a 2-D full-wave calculation, electron damping occurs in an off-axis region at low density, but wave fields become more concentrated in the core and absorption becomes more centrally localized at high density.e

Interaction of Tomato Mosaic Virus Movement Protein with Tobacco RIO Kinase

Hiroshi Nyunoya,Kuniaki Yoshioka,Yasuhiko Matsushita,Masahiro Kasahara,Ken-ichi Konagaya 한국분자세포생물학회 2004 Molecules and cells Vol.17 No.2

Tomato mosaic virus (ToMV) has a regulatory gene encoding a movement protein (MP) that is involved in the cell-to-cell movement of viral RNA through plas-modesmata. To identify the host cell factors interacting with ToMV MP, we used a recombinant MP probe to isolate cDNA clones from a phage expression library of Nicotiana tabacum by a far-Western screening method. One of the cDNA clones encoded an MP-interacting protein, MIP-T7, homologous to the yeast novel pro-tein kinase, Rio1p. We isolated a full-length cDNA by RT-PCR. The putative gene product was designated NtRIO, and shared 33 and 73% amino acid identity with yeast and Arabidopsis RIO kinases, respectively. In vitro analyses using recombinant proteins showed that NtRIO also interacted with a different MP de-rived from Cucumber mosaic virus. NtRIO had auto-phosphorylation activity and phosphorylated ToMV MP. Addition of recombinant tobacco casein kinase 2 resulted in a marked increase in the phosphorylation of NtRIO. The interaction between NtRIO and ToMV MP was inhibited by phosphorylation of NtRIO.

Role of Hydrogen Generation by Klebsiella pneumoniae in the Oral Cavity

Tomoko Kanazuru,Kumiko Nagata,Hiroshi Matsui,Kunihiko Watanabe,Eisuke F. Sato,Emiko Kasahara,Mika Jikumaru,June Inoue,Masayasu Inoue 한국미생물학회 2010 The journal of microbiology Vol.48 No.6

Some gastrointestinal bacteria synthesize hydrogen (H2) by fermentation. Despite the presence of bactericidal factors in human saliva, a large number of bacteria also live in the oral cavity. It has never been shown that oral bacteria also produce H2 or what role H2 might play in the oral cavity. It was found that a significant amount of H2 is synthesized in the oral cavity of healthy human subjects, and that its generation is enhanced by the presence of glucose but inhibited by either teeth brushing or sterilization with povidone iodine. These observations suggest the presence of H2-generating bacteria in the oral cavity. The screening of commensal bacteria in the oral cavity revealed that a variety of anaerobic bacteria generate H2. Among them,Klebsiella pneumoniae (K. pneumoniae) generated significantly large amounts of H2 in the presence of glucose. Biochemical analysis revealed that various proteins in K. pneumoniae are carbonylated under standard culture conditions, and that oxidative stress induced by the presence of Fe++ and H2O2 increases the number of carbonylated proteins, particularly when their hydrogenase activity is inhibited by KCN. Inhibition of H2generation markedly suppresses the growth of K. pneumoniae. These observations suggest that H2 generation and/or the reduction of oxidative stress is important for the survival and growth of K. pneumoniae in the oral cavity.

ZnO coated ball bearing system

Masahiro TOSA,Michiko SASAKI,Masahiro GOTO,Akira KASAHARA,Hiroshi HONDA,Hiroshi SUZUKI 한국진공학회 2016 한국진공학회 학술발표회초록집 Vol.2016 No.8

Growth variation in a natural japanese population of Pleurocybella porrigens

Akira Suzuki,Hoang Pham Nguyen Duc,Kosuke Nakamura,Hiroshi Akiyama,Yoshimasa Kasahara 한국버섯학회 2010 한국버섯학회 국제학술대회 Vol.6 No.-

Growth variation in a natural japanese population of Pleurocybella porrigens

Akira Suzuki,Hoang Pham Nguyen Duc,Kosuke Nakamura,Hiroshi Akiyama,Yoshimasa Kasahara 한국버섯학회 2010 한국버섯학회지 Vol.8 No.4

A basidiomycetous wood rotting fungus Pleurocybella porrigens (angel wings) has been well known as an excellent edible mushroom and named as Sugihiratake, in Japanese common name based on its morphological and ecological features. This mushroom has been favorably consuming by Japanese people. In 2004, an outbreak of serious acute encephalopathy exclusively occurred in patients with chronic kidney diseases after the intake of this mushroom. Thereafter, many researchers have conducted to examine the factor of onset of the encephalopathy, but the exact factors that induced the encephalopathy still remain unclear. Matsumoto et al. (2005) reported the mushroom specimens from different geographical areas in Japan were grouped into two distinct clusters based on ITS rDNA sequences. Vegetative growth of P. porrigens is extremely slow even cultivation on natural media surveyed and its physiological characteristic gives a disadvantage for the development of various fields of researches on this mushroom. Thus, we attempted to find a medium accelerating the vegetative growth of P. porrigens for further research to elucidate the possible association between its chemical constituent(s) and the onset of encephalopathy. Fifteen isolates of P. porrigens collected from different geographical areas in Japan were cultivated on PDA. The growth of the isolates was extremely slow as we know and most tested isolates formed mycelia look like those often observed in the cultivation of basidiomycetous ectomycorrhizal fungi. Among them, we chose five isolates based on the ranking of their higher growth rates. The top five isolates were cultured in five kinds of liquid media, PD medium, MY medium, Carrot medium, Ohta’s medium for ectomycorrhizal fungi (Ohta, 1990) and Amazake medium (Ishihara, 2007), and on a solid medium, PDA, at 20℃ in the dark. The dry biomasses of the isolates cultured in the liquid media were determined after 6 weeks of the stationary cultivation whereas the growth rates of the isolates cultured on PDA were compared by the colony diameter after 8 weeks of the cultivation. Among the tested liquid media, PD medium was the most suitable medium for their biomass growth (17 mg dry mycelium/flask - 127 mg dry mycelium/flask) and followed by Ohta’s medium (13 mg dry mycelia/flask - 79 mg dry mycelia/flask), MY medium (10 mg dry mycelium/flask - 72 mg dry mycelium/flask), Amazake medium (8 mg dry mycelium/flask - 47 mg dry mycelium/flask) and Carrot medium (4 mg dry mecelium/flask - 18 mg dry mycelium/flask). The average biomass growths of the isolates cultured in the synthetic medium, Ohta’s medium were 20-92% of those of the isolates cultured in PD medium. No correlation was observed between the cultivation in PD medium (liquid medium) and that on PDA (solid medium). Extremely large biomass variation was observed among the same isolates cultured on the same kind of the liquid medium. Large variation in colony features associated with their growth rates was also observed among the isolates cultured on PDA. These results suggest that PD medium would be a suitable one for most researches and Ohta’s medium for researches requiring clarity of its chemical constituents. The above results also indicate that the Japanese population of P. porrigens has large variation in vegetative growth although we have not yet examined whether the tested isolates comprise cryptic species or not.