Photosystem I and II Reaction Centers in a New Type Oxygenic Photosynthesis of Acaryochloris marina Based on Chlorophyll d: Studies of Delayed Fluorescence and Triplet State ESR

Itoh, Shigeru,Fukushima, Yoshimasa,Itoh, Kunihiro,Maeda, Masanori,Mino, Hiroyuki,Kumazaki, Shigeichi Korean Society of Photoscience 2002 Journal of Photosciences Vol.9 No.2

A cyanobacteria-like organism Aaryochloris marina performs oxygenic photosynthesis with near far-red light by the use of chlorophyll d. Reaction center chlorophyll (Chl) of Photosystem (PS) II of A. marina was studied by analysis of millisecond-delayed fluorescence. Delayed fluorescence is emitted by Chi d indicating efficient energy transfer between antenna Chi d molecules and the unknown primary electron donor of PS II. P740 a reaction center Chl of PS I of A. marina is shown to give a dimer type cation, and triplet state with a D value of 245xlO$\^$-4/ cm$\^$-l/ in contrast to the 280-290 xlO$\^$-4/cm$\^$-l/ values of P700 suggesting triplet spins interacting at a 5% larger distance in P740 than in P700.

Hysteresis and fast timescales in transport relations of toroidal plasmas

Itoh, K.,Itoh, S.-I.,Ida, K.,Inagaki, S.,Kamada, Y.,Kamiya, K.,Dong, J.Q.,Hidalgo, C.,Evans, T.,Ko, W.H.,Park, H.,Tokuzawa, T.,Kubo, S.,Kobayashi, T.,Kosuga, Y.,Sasaki, M.,Yun, G.S.,Song, S.D.,Kasuya, International Atomic Energy Agency 2017 Nuclear fusion Vol.57 No.10

<P>This article assesses current understanding of hysteresis in transport relations, and its impact on the field. The rapid changes of fluxes compared to slow changes of plasma parameters are overviewed for both core and edge plasmas. The modulation ECH experiment is explained, in which the heating power cycles on-and-off periodically, revealing hysteresis and fast changes in the gradient–flux relation. The key finding is that hystereses were observed simultaneously in both the the gradient–flux and gradient–fluctuation relations. Hysteresis with rapid timescale exists in the channels of energy, electron and impurity densities, and plausibly in momentum. Advanced methods of data analysis are explained. Transport hysteresis can be studied by observing the higher harmonics of temperature perturbation <img ALIGN='MIDDLE' ALT='$\delta T_{\rm m}$ ' SRC='http://ej.iop.org/images/0029-5515/57/10/102021/nfaa796aieqn001.gif'/> in heating modulation experiments. The hysteresis introduces the term <img ALIGN='MIDDLE' ALT='$\delta T_{\rm m}$ ' SRC='http://ej.iop.org/images/0029-5515/57/10/102021/nfaa796aieqn002.gif'/>, which depends on the harmonic number <I>m</I> in an algebraic manner (not exponential decay). Next, the causes of hysteresis and its fast timescale are discussed. The nonlocal-in-space coupling works here, but does not suffice. One mechanism for ‘the heating heats turbulence’ is that the external source <I>S</I> in phase space for heating has its fluctuation in turbulent plasma. This coupling can induce the direct input of heating power into fluctuations. The height of the jump in transport hysteresis is smaller for heavier hydrogen isotopes, and could be one of the origins of isotope effects on confinement. Finally, the impacts of transport hysteresis on the control system are assessed. Control systems must be designed so as to protect the system from sudden plasma loss.</P>

Comparison of Electronic-Excitation-Induced Structural Modification of Carbon-Based Nanomaterials with that of Semiconductor Surfaces

Noriaki Itoh,Chihiro Itoh,Junichi Kanasaki 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2016 NANO Vol.11 No.6

Modification by electronic excitation of semiconductor surfaces and carbon-related quasi-twodimensional (2D) nanostructured materials, namely graphene, carbon nanotubes is reviewed. Defect creation in these materials takes place not by low-intensity photoirradiation, but by laser or electron irradiation. The defect creation processes are different from ordinary photochemical processes in molecules or in some solids like alkali halides, which can be modified by a localized exciton. It is pointed out that there are common features in defect creation by electronic excitation in semiconductor surfaces and carbon-related quasi-2D nanomaterials: the yield-intensity relation shows strong superlinearity for laser irradiation near the bandgap energies and linearity or weak superlinearity for higher energy electron or photon irradiation. These results are explained in terms of multi-hole localization, in which bonds are weakened more strongly and more energy is available upon recombination with trapped electrons in comparison with excitons. The multi-hole localized state is considered to be realized by the creation of dense excitons or by cascade excitation for laser irradiation and by multiple excitations or multiple exciton generation by single impacts for electron irradiation. The review includes also polymerization of C60 films by electronic excitation, which is induced by low-intensity photoirradiation as well as by laser or electron irradiation. The experimental observation that laser or electron irradiation polymerize C60 films differently from low-intensity photoirradiation is explained in terms of multi-hole localization similar to the defect formation mechanism. Although fragmentation of C60 is due to electronic excitation of the molecule, it is included in the review because its yield is strongly superlinear for laser irradiation near bandgap energies and weakly superlinear for high-energy electron or photon irradiation as for other cases.

Electroretinography recordings using a light emitting diode active corneal electrode in healthy beagle dogs

Yoshiki Itoh,Yasuharu Izumisawa,Seiya Maehara,Kazuto Yamashita,Norihiko Itoh 대한수의학회 2013 Journal of Veterinary Science Vol.14 No.1

Electroretinography (ERG) is a well-established diagnostic procedure for objectively evaluating retinal function. In this study, ERG in beagle dogs, which are a popular experimental animal, was performed to determine the normal range of ERG variables and assess differences between the left and right eyes. ERG findings including rod, combined rod-cone,single-flash cone, and 30-Hz flicker responses were recorded with an LED-electrode in 43 sedated beagle dogs. The subjects were divided into young (< 1 year old), adult (1∼5years old), and senile animals (≥ 6 years old). Normal ERG ranges were obtained. Significant differences in b-wave amplitude along with b/a ratio of the combined rod-cone response were found between the young and adult animals as well as young and senile dogs. No significant differences were observed between the left and right eyes. ERG variables in beagle dogs differed by age due to age-related retinal changes. Thus, we propose that normal ERG ranges should be determined according to age in each clinic and laboratory using its own equipment because each institution usually has different systems or protocols for ERG testing.

Entropic mechanism of large fluctuation in allosteric transition

Itoh, K.,Sasai, M. National Academy of Sciences 2010 PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF Vol.107 No.17

Nonlinear collision analysis of heavy trucks onto steel highway guard fences

Itoh, Yoshito,Liu, Chunlu,Usami, Koichi Techno-Press 2001 Structural Engineering and Mechanics, An Int'l Jou Vol.12 No.5

The design specifications of guard fences in Japan were reexamined and the revised specifications were implemented from April 1999. Because of the huge consumption in time and cost to test the performances of full-scale guard fences in the field, some assumptions are adopted while modifying the design specifications, and numerical analyses are necessary to confirm the impact performance and safety level of new types of steel highway guard fences. In this study, the finite element models are developed for the heavy trucks and steel highway guard fences to reenact their behaviors, and the solution approach is carried out using nonlinear dynamic analysis software of structures in three dimensions (LS-DYNA). The numerical simulation results are compared with the full-scale on-site testing results to verify the proposed analysis procedure. The collision process is simulated and it is also made possible to visualize the movement of the truck and the performances of guard fences. In addition, the energy shift of the truck kinetic energy to the truck and guard fence Internal energy, and the energy absorption of each guard fence component are studied for the development of a new design methodology of steel highway guard fences based on the energy absorption capacity.

A Novel Paramyxean Parasite, Marteilia granula sp. nov. (Cercozoa), from the Digestive Gland of Manila Clam Ruditapes philippinarum in Japan

Itoh, Naoki,Yamamoto, Toshihiro,Kang, Hyun-Sil,Choi, Kwang-Sik,Green, Timothy J.,Carrasco, No^,^egrave,lia,Awaji, Masahiko,Chow, Seinen The Japanese Society of Fish Pathology 2014 Fish pathology Vol.49 No.4

Nanocommunication Design in Graduate-Level Education and Research Training

Itoh, Tadashi,Akai, Hisazumi,Takeda, Seiji,Ogawa, Hisahito,Ichikawa, Satoshi,Geshi, Masaaki,Ara, Masato,Niioka, Hirohiko The Korean Vacuum Society 2010 Applied Science and Convergence Technology Vol.19 No.6

나노과학, 나노공학, 및 나노기술의 축적된 지식을 대중참여라는 관점을 첨가하여 대학원생이나 젊은 과학자들에게 가르치기 위하여, 오사카 대학은 2004년부터 다양한 교육 및 훈련 프로그램을 제공하고 있는데, 교학문적(交學問的) 대학원 부전공 과목, 야간 강좌, 단기 국제훈련 프로그램 등이다. 연속강의는 위성통신을 이용하여 교실에 전달되기도 한다. 또한 학생들은 현대시설을 활용한 실습을 통하여 직접, 나노소재와 나노소자를 설계, 제작, 측정, 특성분석 및 기능화 할 수 있다. 그리고 특별히 사회적, 법적, 윤리적 관계를 포함하는 나노소통에 관한 연구훈련 프로그램과 강좌 시리즈가 네 개 개설되어 있으니, "나노기술 경력 건설 강좌", "나노기술의 대중 참여", "나노기술 지도 설계", "목적과제 학습 및 훈련 프로그램(PAL)"이다. 전체 프로그램의 윤곽이 나노소통 특별 프로그램과 함께 소개되어 있다. In order to teach the accumulated knowledge of nanoscience, nanoengineering and nanotechnology to graduate school students and young scientists with the sense of public engagement, Osaka University started from 2004 to prepare and offer various kinds of education and training programs such as trans-disciplinary graduate-school minor program, evening course refresher program, short-term international research training program, etc. It offers a series of lectures, partly broadcasted live to satellite classrooms. In addition, the students can join intensive hands-on training programs using modern facilities, allowing them to design, fabricate, measure, characterize and functionalize nanomaterials and nanodevices. In addition, there are four specially designed lectures and research training programs aimed for nanocommunication including social, legal and ethical relationship: "Nanotechnology Career-up Lectures", "Social Engagement on Nanotechnology", "Road Map Design on Nanotechnology", and "Project-Aimed Learning and Training Programs (PAL)". The outline of the whole programs is described together with the specialized programs for nanocommunication.

Fabrication and Applications of Comb-Shaped Lateral Field Emitter Arrays

Itoh, Junji 한국진공학회 1993 Applied Science and Convergence Technology Vol.2 No.3

여러 종류의 수직 또는 수평 형태의 field emitter array가 연구되었다. 그 중 수평형의 FEA는 emitter가 동일 평면 위에 구성되어 있고, gate는 고주파의 응용을 위하여서는 더욱 적합하다. 이 빗살 모양의 FEA의 구조, emission 성질, 응용에 대하여 설명한다.

Investigation of Lattice Effects in Perovskites by $O-isotope^{18}$ Exchange

Itoh, Mitsuru,Mahesh, Rajappan,Wang, Ruiping The Korean Ceramic Society 2000 The Korean journal of ceramics Vol.6 No.3

In the present study, preliminary experimental results of the change in the properties of perovskite-type oxides caused by the $^{18}O$- exchange have been reported. Two systems were selected for the exchange, (1) $ATiO_3$(A=Ca,Sr,Ba) and (2) manganese perovskite. The dielectric properties of isotope-exchanged $SrTi^{18}O_3$showed a drastic change from a quantum paraelectricity below 3K to ferroelectric-like behavior with a peak at 23K and an enhanced dielectric constant, 35000 at the peak. On the contrary, the $T_c$ for $BaTiO_3$was found to increase by 0.9K. The observed isotope shift of $T_c$ as well as $T_co$ for the manganese perovskites is correlated with the key parameters controlling the lattice such as $Mn^{3+}$ content, average ionic radius of the A-site cation <$r_A$> ad A-site ionic disorder $\sigma^2$.