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Ikeuchi, Hirotomo; Sasaki, Shinji; Onishi, Takashi; Nakayoshi, Akira; Arai, Yoichi; Sato, Takumi; Ohgi, Hiroshi; Sekio, Yoshihiro; Yamaguchi, Yukako; Morishita, Kazuki; et al.
JAEA-Data/Code 2023-005, 418 Pages, 2023/12
JAEA-Data-Code-2023-005-01.pdf:24.59MBJAEA-Data-Code-2023-005-02.pdf:32.18MB
For safe and steady decommissioning of Tokyo Electric Power Company Holdings' Fukushima Daiichi Nuclear Power Station (1F), information concerning composition and physical/chemical properties of fuel debris generated in the reactors should be estimated and provided to other projects conducting the decommissioning work including the retrieval of fuel debris and the subsequent storage. For this purpose, in FY2021, samples of contaminants (the wiped smear samples and the deposits) obtained through the internal investigation of the 1F Unit 2 were analyzed to clarify the components and to characterize the micro-particles containing uranium originated from fuel (U-bearing particles) in detail. This report summarized the results of analyses performed in FY2021, including the microscopic analysis by SEM and TEM, radiation analysis, and elemental analysis by ICP-MS, as a database for evaluating the main features of each sample and the probable formation mechanism of the U-bearing particles.
Nakayoshi, Akira; Mitsugi, Takeshi; Sasaki, Shinji; Maeda, Koji
JAEA-Data/Code 2021-011, 279 Pages, 2022/03
JAEA-Data-Code-2021-011.pdf:37.76MB
At the TEPCO's Fukushima Daiichi Nuclear Power Station (1F), an investigation inside the reactors has been carried out, and R&D has been made on methods of fuel debris retrieval and storage after retrieval. In order to carry out the decommissioning work safely and steadily, understanding characteristics of fuel debris in the reactors is required. Therefore, in the development of technologies for grasping and analyzing properties of fuel debris project, the characteristics of simulated fuel debris, such as hardness, drying behavior, etc., of fuel debris for design of removal and storage, have been investigated and estimated, and provided to other projects conducting the decommissioning work. As part of this project, U-containing particles in samples (e.g., deposit on the investigation equipment, sediment in the reactors, etc.) obtained during the internal investigation of the reactors of 1F units 1 to 3 were analyzed. This report summarized the results of FE-SEM/WDX, FE-SEM/EDS, STEM/EDS, and TEM analysis, which were extracted from all analysis results obtained, as a database for the evaluation of the generation mechanism of U-containing particles. The analyses were performed at the JAEA Oarai Research and Development Institute and Nippon Nuclear Fuel Development Co., LTD.
Matsumoto, Fumiko; Maeda, Kayo*; Chatake, Toshiyuki*; Maeda, Yuichiro*; Fujiwara, Satoru
Biochemical and Biophysical Research Communications, 382(1), p.205 - 209, 2009/04
Times Cited Count：15 Percentile：37.83(Biochemistry & Molecular Biology)Two cardiomyopathy-causing mutations, E244D and K247R, in human cardiac troponin T (TnT) are located in the coiled-coil region of the Tn-core domain. To elucidate effects of mutations in this region on the regulatory function of Tn, we measured Ca
-dependent ATPase activity of myofibrils containing various mutants of TnT at these residues. The results confirmed that the mutant E244D increases the maximum ATPase activity without changing the Ca sensitivity. The mutant K247R was shown for the first time to have the effect similar to the mutant E244D. Furthermore, various TnT mutants (E244D, E244M, E244A, E244K, K247R, K247E, and K247A) showed various effects on the maximum ATPase activity while the Ca sensitivity was unchanged. Molecular dynamics simulations of the Tn-core containing these TnT mutants suggested that the hydrogen-bond network formed by the side chains of neighboring residues around residues 244 and 247 is important for Tn to function properly.
have an anomalous endohedral structure? Synthesis and single crystal X-ray structure of the carbene adductAkasaka, Takeshi*; Kono, Takayoshi*; Takematsu, Yuji*; Nikawa, Hidefumi*; Nakahodo, Tsukasa*; Wakahara, Takatsugu*; Ishitsuka, Midori*; Tsuchiya, Takahiro*; Maeda, Yutaka*; Liu, M. T. H.*; et al.
Journal of the American Chemical Society, 130(39), p.12840 - 12841, 2008/10
Times Cited Count：76 Percentile：84.42(Chemistry, Multidisciplinary)We report here the results on single crystal X-ray crystallographic analysis of the Gd@C carbene adduct (Gd@C(ad), Ad=adamantylidene). The Gd atom in Gd@C(Ad) is located at an off-centered position near a hexagonal ring in the C2v-C cage, as found for M@C (M = Sc and La) and La@C(Ad). Theoretical calculation also confirms the position of the Gd atom in the X-ray crystal structure.
Matsumoto, Fumiko*; Makino, Koji*; Maeda, Kayo*; Patzelt, H.*; Maeda, Yuichiro*; Fujiwara, Satoru
Journal of Molecular Biology, 342(4), p.1209 - 1221, 2004/09
Times Cited Count：19 Percentile：29.79(Biochemistry & Molecular Biology)Regulation of skeletal and cardiac muscle contraction is associated with the thin filament-based proteins, troponin C (TnC), TnI, TnT, tropomyosin, and actin. Knowledge of 
structures of these proteins is indispensable for elucidating the molecular mechanism of this Ca-sensitive regulation. Here the structure of TnC within the thin filaments was investigated with neutron scattering, combined with selective deuteration and the contrast matching technique. Deuterated TnC was prepared, reconstituted into the native thin filaments, and neutron scattering patterns of these reconstituted thin filaments containing deuterated TnC were measured under the condition where non-deuterated components were rendered 'invisible' to neutrons. The obtained scattering curves arising only from deuterated TnC were analyzed by model calculations using the Monte Carlo method. The results showed that upon binding of Ca, radius of gyration of TnC changed from 23 AA to 24 AA , and the radial position of TnC within the thin filament changed from 53 AA to 49 AA .
Aoyagi, Takayoshi*; *; Mihara, Morihiro; Okutsu, Kazuo*; Maeda, Munehiro*
JNC TN8400 2001-024, 103 Pages, 2001/06
JNC-TN8400-2001-024.pdf:8.84MB
In the disposal concept of TRU waste, concentrated disposal of wastes forms in large cross-section underground cavities is envisaged, because most of TRU waste is no-heat producing in spite of large generated volume as compared with HLW. In the design of engineered barrier system based on large cross-section cavities, it is necessary to consider the long-term mechanical process such as creep displacement of the host rock from the viewpoint of the stability of engineered barrier system. In this study, the long-term creep displacement of the host rock was calculated using the non-linear viscoelasticity model and the effects on the stability of engineered barrier system was evaluated. As a result, in the disposal concept of crystalline rock, no creep displacement occurred at the time after 1 milion year. On the other hand, in the disposal concept of sedimentary rock, creep displacement of 80
90mm occurred at the time after 1 milion year. Also, in this calculation, a maximum reduction of 45mm concerned with the thickness of buffer material was estimated. But these values resulted within allowance of design values. Therefore, these results show that the effects of the creep displacement on the stability of engieered barrier system would not be significant.
Aoyagi, Takayoshi*; Maeda, Munehiro*; Mihara, Morihiro; Tanaka, M.*
JNC TN8400 98-002, 62 Pages, 1998/11
Tests to determine the swelling pressure, permeability, compressive strength and elastic modulus of Ca-Na exchanged bentonite, Na-bentonite and Ca-bentonite at the Power Reactor and Nuclear Fuel Development Corporation have mainly used distilled water. However, disposal facilities for TRU waste will use cementateous material for packaging, backfill as well as structural support. In this case, a large amount of calcium will dissolve in groundwater flowing through the cementateous material. Therefore, it is important to investigate the mechanical properties of bentonite in calcium-rich water as part of the disposal research program for TRU waste. In order to understand the effect of the chemical composition of water on the basic mechanical properties of bentonite - part of evaluating the disposal concepts for TRU waste disposal - we tested the permeability of compacted bentonite under saturated conditions using a calcium hydroxide solution. The aqueous solution represents water dominated by the calcium component. Na-bentonite, Ca-Na exchanged bcntonite and Ca-bentonite were used for swelling pressure measurement tests and permeability testing. Measures of the maximum and equilibrium swelling pressure as well as permeability were obtained. The dry density of bentonite was varied between tests. Results show that swelling pressure and permeability are dependent on dry density. In separate tests usig Ca-bentonite, the bentonite-mixing rate was varied as an independent parameter. Results show that there is little change in the swelling pressure and permeability between tests usig calcium hydroxide solution and distilled water for all bentonite types.
sensitization in the myofibrilsMatsumoto, Fumiko; Maeda, Kayo*; Nitanai, Yasushi*; Oda, Toshiro*; Maeda, Yuichiro*; Fujiwara, Satoru
no journal, ,
Familial hypertrophic cardiomyopathy (HMC) has been reported to be caused by mutations in a regulatory protein, troponin (Tn). HMC is characterized by functional aberration on the force-pCa relationship. Only a few cardiomyopathy-causing mutations have been mapped on the coiled-coil region (IT-arm) in the Tn core domain. Here we focus on two mutations in the IT-arm, E244D and K247R of TnT. Whereas E244D has been reported to show an increase of the maximum level of ATPase activity, the functional consequence of K247R mutation has not been analyzed. In order to understand how these mutations cause functional aberrations, we measured ATPase activity of myofibrils containing various mutants of these residues (E244; D, M, A, K and K247; R, E, A). The maximum level of ATPase activity was found to increase in K247R, without changing the Ca ion sensitivity, as found in E244D. A close inspection of the crystal structure showed that the side chains of E244 and K247 form the triplet with that of E110 of TnI on the outside of the hydrophobic core of the coiled-coil. This triplet is thus likely to introduce flexibility into the IT-arm at this position. The mutations at the residues 244 and 247 could alter this flexibility. The results obtained here suggested that the proper flexibility of the IT-arm is important for the correct function of the myofibrils. The relationship between the IT-arm flexibility and functional aberration in the myofibril will be discussed.
Matsumoto, Fumiko; Maeda, Kayo*; Piroddi, N.*; Belus, A.*; Poggesi, C.*; Maeda, Yuichiro*; Fujiwara, Satoru
no journal, ,
Hypertrophic cardiomyopathy (HCM) is an autosomal dominant cardiac disease resulting from mutations in genes encoding contractile proteins, including troponin. HMC is characterized by functional aberration on the force-pCa relationship. Only a few HMC-causing mutations have been mapped on the coiled-coil region in the Tn core. Here we focus on two mutations in this region, E244D and K247R of TnT. Whereas E244D has been reported to show an increase of the maximum level of ATPase activity without changing the Ca sensitivity (Yanaga et. al., 1999), the functional consequence of K247R mutation has not been analyzed. We showed from the ATPase measurements of myofibrils containing the mutants K247R that this mutation exhibits similar functional consequences to the mutation E244D. Moreover, in order to understand how the mutations at these residues cause functional aberrations, we prepared various mutants of TnT (E244D, E244M, E244A, E244K, K247R, K247E, and K247A), having various volumes and charges, and measured ATPase activity of myofibrils containing these mutants TnT. The effect of mutations on the maximum ATPase activity level was different from each other while the Ca sensitivity was unchanged. To gain insight into the relationship between the ATPase activity and (possible) structural changes caused by these mutations, we carried out energy minimization/molecular dynamics calculations based on the crystal structure of the Tn-core. The results suggested that the stable hydrogen bond network at this region is important for the "proper" function of Tn.
Matsumoto, Fumiko; Piroddi, N.*; Belus, A.*; Scellini, B.*; Maeda, Kayo*; Tesi, C.*; Poggesi, C.*; Maeda, Yuichiro*; Fujiwara, Satoru
no journal, ,
We showed that two Hypertrophic Cardiomyopathy -associated mutations of TnT, E244D and K247R, increase the maximum ATPase activity without any change in Ca ion sensitivity in BSJ 2007. It is, however, still not clear if the mutations have direct effects on the muscle. We thus examined the maximal isometric tension and kinetics of Tn-exchanged myofibrils by use single myofibril. The results indicate that the effects of the mutations on the physiological function of the myofibrils are directly coupled with the effects on the ATPase activity. And the mutant TnT exchanged myofibrils had similar kinetics as the wild type.
Kitamura, Ryoichi; Maeda, Yukimoto; Kobayashi, Takayoshi
no journal, ,
no abstracts in English
Saegusa, Jun; Yanagisawa, Kayo; Yamaguchi, Toshio; Manabe, Sachi; Yoda, Tomoyuki; Maeda, Satoshi; Utsumi, Azusa; Shibamichi, Masaru; Ejiri, Akira; Kurita, Yoshiyuki; et al.
no journal, ,
no abstracts in English
