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Muramatsu H, Kambe T, Tsukamoto T, Kuzume A, Hosono R, Imaoka T, Yamamoto K. Synthesis and functionalities of FeSn 12 superatom prepared by single atom introduction with a dendrimer template. Chemistry 2024; 30:e202400060. [PMID: 38263351 DOI: 10.1002/chem.202400060] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2024] [Accepted: 01/16/2024] [Indexed: 01/25/2024]
Abstract
Superatoms are promising as new building block materials that can be designed by precise controlling of the constituent atoms. Stannaspherene (Sn12 2-) is a rigid cage-like cluster with icosahedral symmetry, for which one-atom encapsulation was theoretically expected and detected in the gas phase. Here, a single-atom introduction method into stannaspherene using a dendrimer template with polyvinylpyrrolidone (PVP) protection is demonstrated. This advanced solution-phase synthesis allows not only the selective doping of one atom into the cluster cage, but also enable further detail characterization of optical and magnetic properties that were not possible in the gas-phase synthesis. In other words, this liquid-phase synthesis method has enabled the adaptation of detailed analytical methods. In this study, FeSn12 was synthesized and characterized, revealing that a single Fe atom introduction in the Sn12 2- cage result in the appearance of near-infrared emission and enhancement in the magnetism.
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Affiliation(s)
- Hisanori Muramatsu
- Laboratory for Chemistry and Life Science, JST-ERATO, Yamamoto Atom Hybrid Project, Tokyo Institute of Technology, Yokohama, 226-8503, Japan
| | - Tetsuya Kambe
- Laboratory for Chemistry and Life Science, JST-ERATO, Yamamoto Atom Hybrid Project, Tokyo Institute of Technology, Yokohama, 226-8503, Japan
- Division of Applied Chemistry, Graduate School of Engineering, Osaka University, Osaka, 565-0871, Japan
| | - Takamasa Tsukamoto
- Laboratory for Chemistry and Life Science, JST-ERATO, Yamamoto Atom Hybrid Project, Tokyo Institute of Technology, Yokohama, 226-8503, Japan
- JST-PRESTO, Kawaguchi, Saitama, 332-0012, Japan
- Institute of Industrial Science, The University of Tokyo, Tokyo, 153-8505, Japan
| | - Akiyoshi Kuzume
- Laboratory for Chemistry and Life Science, JST-ERATO, Yamamoto Atom Hybrid Project, Tokyo Institute of Technology, Yokohama, 226-8503, Japan
- Clean Energy Research Center, University of Yamanashi, Kofu, 400-8510, Japan
| | - Reina Hosono
- Laboratory for Chemistry and Life Science, JST-ERATO, Yamamoto Atom Hybrid Project, Tokyo Institute of Technology, Yokohama, 226-8503, Japan
| | - Takane Imaoka
- Laboratory for Chemistry and Life Science, JST-ERATO, Yamamoto Atom Hybrid Project, Tokyo Institute of Technology, Yokohama, 226-8503, Japan
| | - Kimihisa Yamamoto
- Laboratory for Chemistry and Life Science, JST-ERATO, Yamamoto Atom Hybrid Project, Tokyo Institute of Technology, Yokohama, 226-8503, Japan
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2
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Atqa A, Yoshida M, Wakizaka M, Chun WJ, Oda A, Imaoka T, Yamamoto K. Ultra-small Mo-Pt subnanoparticles enable CO 2 hydrogenation at room temperature and atmospheric pressure. Chem Commun (Camb) 2023; 59:11947-11950. [PMID: 37668093 DOI: 10.1039/d3cc02703a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/06/2023]
Abstract
We present a partially-oxidised bimetallic Mo-Pt subnanoparticle (Mo4Pt8Ox) enabling thermally-driven CO2 hydrogenation to CO at room temperature and atmospheric pressure. A mechanistic study explained the full catalytic cycle of the reaction from CO2 activation to catalyst reactivation. DFT calculations revealed that alloying with Mo lowers the activation barrier by weakening the CO adsorption. This finding could be a first step for low-energy CO2 conversion.
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Affiliation(s)
- Augie Atqa
- Institute of Innovative Research, Tokyo Institute of Technology, Yokohama 226-8503, Japan.
| | - Masataka Yoshida
- Institute of Innovative Research, Tokyo Institute of Technology, Yokohama 226-8503, Japan.
| | - Masanori Wakizaka
- Graduate School of Photonics Science, Chitose Institute of Science and Technology, Chitose 066-0012, Japan
| | - Wang-Jae Chun
- Graduate School of Arts and Sciences, International Christian University, Tokyo 181-8585, Japan
| | - Akira Oda
- Graduate School of Engineering, Nagoya University, Nagoya 464-8603, Japan
| | - Takane Imaoka
- Institute of Innovative Research, Tokyo Institute of Technology, Yokohama 226-8503, Japan.
- JST ERATO Yamamoto Atom Hybrid Project, Tokyo Institute of Technology, Yokohama 226-8503, Japan
| | - Kimihisa Yamamoto
- Institute of Innovative Research, Tokyo Institute of Technology, Yokohama 226-8503, Japan.
- JST ERATO Yamamoto Atom Hybrid Project, Tokyo Institute of Technology, Yokohama 226-8503, Japan
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3
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Zou Q, Akada Y, Kuzume A, Yoshida M, Imaoka T, Yamamoto K. Alloying at a Subnanoscale Maximizes the Synergistic Effect on the Electrocatalytic Hydrogen Evolution. Angew Chem Int Ed Engl 2022; 61:e202209675. [PMID: 35912811 DOI: 10.1002/anie.202209675] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2022] [Indexed: 01/07/2023]
Abstract
Bonding dissimilar elements to provide synergistic effects is an effective way to improve the performance of metal catalysts. However, as the properties become more dissimilar, achieving synergistic effects effectively becomes more difficult due to phase separation. Here we describe a comprehensive study on how subnanoscale alloying is always effective for inter-elemental synergy. Thirty-six combinations of both bimetallic subnanoparticles (SNPs) and nanoparticles (NPs) were studied systematically using atomic-resolution imaging and catalyst benchmarking based on the hydrogen evolution reaction (HER). Results revealed that SNPs always produce greater synergistic effects than NPs, the greatest synergistic effect was found for the combination of Pt and Zr. The atomic-scale miscibility and the associated modulation of electronic states at the subnanoscale were much different from those at the nanoscale, which was observed by annular-dark-field scanning transmission electron microscopy (ADF-STEM) and X-ray photoelectron spectroscopy (XPS), respectively.
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Affiliation(s)
- Quan Zou
- Laboratory for Chemistry and Life Science (CLS), Institute of Innovative Research (IIR), Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama, 226-8503, Japan
| | - Yuji Akada
- Laboratory for Chemistry and Life Science (CLS), Institute of Innovative Research (IIR), Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama, 226-8503, Japan
| | - Akiyoshi Kuzume
- JST-ERATO, YamamotoAtom Hybrid Project, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama, 226-8503, Japan
| | - Masataka Yoshida
- Laboratory for Chemistry and Life Science (CLS), Institute of Innovative Research (IIR), Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama, 226-8503, Japan.,JST-ERATO, YamamotoAtom Hybrid Project, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama, 226-8503, Japan
| | - Takane Imaoka
- Laboratory for Chemistry and Life Science (CLS), Institute of Innovative Research (IIR), Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama, 226-8503, Japan.,JST-ERATO, YamamotoAtom Hybrid Project, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama, 226-8503, Japan
| | - Kimihisa Yamamoto
- Laboratory for Chemistry and Life Science (CLS), Institute of Innovative Research (IIR), Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama, 226-8503, Japan.,JST-ERATO, YamamotoAtom Hybrid Project, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama, 226-8503, Japan
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4
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Yamamoto K, Zou Q, Akada Y, Kuzume A, Yoshida M, Imaoka T. Alloying at a Subnanoscale Maximizes the Synergistic Effect on the Electrocatalytic Hydrogen Evolution. Angew Chem Int Ed Engl 2022. [DOI: 10.1002/ange.202209675] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Affiliation(s)
- Kimihisa Yamamoto
- Tokyo Institute of Technology 4259 Nagatsuta 226-8503 Yokohama JAPAN
| | - Quan Zou
- Tokyo Institute of Technology: Tokyo Kogyo Daigaku Laboratory of Chemistry and Life Science JAPAN
| | - Yuji Akada
- Tokyo Institute of Technology: Tokyo Kogyo Daigaku Laboratory for Chemistry and Life Science JAPAN
| | - Akiyoshi Kuzume
- Tokyo Institute of Technology: Tokyo Kogyo Daigaku JST - ERATO, YamamotoAtom Hybrid Project JAPAN
| | - Masataka Yoshida
- Tokyo Institute of Technology: Tokyo Kogyo Daigaku Laboratory of Chemistry and Life Science JAPAN
| | - Takane Imaoka
- Tokyo Institute of Technology: Tokyo Kogyo Daigaku Laboratory of Chemistry and Life Science JAPAN
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5
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Kozumi H, Tanabe M, Kambe T, Imaoka T, Chun WJ, Yamamoto K. Copper-bismuth binary oxide clusters: an efficient catalyst for selective styrene bisperoxidation. CHEM LETT 2022. [DOI: 10.1246/cl.210725] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- Hiromu Kozumi
- Laboratory for Chemistry and Life Science (CLS), Tokyo Institute of Technology, Yokohama 226-8503, Japan
| | - Makoto Tanabe
- ERATO−JST, Yamamoto Atom Hybrid Project, Tokyo Institute of Technology, Yokohama 226-8503, Japan
| | - Tetsuya Kambe
- Laboratory for Chemistry and Life Science (CLS), Tokyo Institute of Technology, Yokohama 226-8503, Japan
- ERATO−JST, Yamamoto Atom Hybrid Project, Tokyo Institute of Technology, Yokohama 226-8503, Japan
| | - Takane Imaoka
- Laboratory for Chemistry and Life Science (CLS), Tokyo Institute of Technology, Yokohama 226-8503, Japan
- ERATO−JST, Yamamoto Atom Hybrid Project, Tokyo Institute of Technology, Yokohama 226-8503, Japan
| | - Wang-Jae Chun
- Graduate School of Arts and Sciences, International Christian University, Mitaka, Tokyo 181-8585, Japan
| | - Kimihisa Yamamoto
- Laboratory for Chemistry and Life Science (CLS), Tokyo Institute of Technology, Yokohama 226-8503, Japan
- ERATO−JST, Yamamoto Atom Hybrid Project, Tokyo Institute of Technology, Yokohama 226-8503, Japan
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6
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Wakizaka M, Chun WJ, Imaoka T, Yamamoto K. Synthesis and magnetic properties of sub-nanosized iron carbides on a carbon support. RSC Adv 2022; 12:3238-3242. [PMID: 35425399 PMCID: PMC8979317 DOI: 10.1039/d1ra09191c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2021] [Accepted: 01/18/2022] [Indexed: 11/30/2022] Open
Abstract
Iron carbide clusters with near-sub-nanometer size have been synthesized by employing a tetraphenylmethane-cored phenylazomethine dendrimer generation 4 (TPM-DPAG4) as a molecular template. Magnetic measurements reveal that these iron carbide clusters exhibit a magnetization–field hysteresis loop at 300 K. The data indicate that these iron carbide clusters are ferromagnets at room temperature. This study reports the synthesis and ferromagnetism of iron carbide clusters with near-subnanometer size by employing a dendrimer template and carbothermal hydrogen reduction (CHR).![]()
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Affiliation(s)
- Masanori Wakizaka
- Laboratory for Chemistry and Life Science Institute of Innovative Research, Tokyo Institute of Technology Yokohama 226-8503 Japan
| | - Wang-Jae Chun
- Graduate School of Arts and Sciences, International Christian University Tokyo 181-8585 Japan
| | - Takane Imaoka
- Laboratory for Chemistry and Life Science Institute of Innovative Research, Tokyo Institute of Technology Yokohama 226-8503 Japan
| | - Kimihisa Yamamoto
- Laboratory for Chemistry and Life Science Institute of Innovative Research, Tokyo Institute of Technology Yokohama 226-8503 Japan
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Abstract
Dendrimers, which are highly branched polymers and regarded as huge single molecules, are interesting substances from the aspect of not only polymer chemistry but also molecular chemistry. Various applications in materials science and life science have been investigated by taking advantage of the radially layered structures and intramolecular nanospaces of dendrimers. Most dendrimers have flexible structures that originate from their organic chains which contain many sp3-type atoms, while relatively rigid dendrimers composed only of sp2-type atoms have rarely been reported. It has been recently clarified that such rigid dendrimers exhibit a specific aromatic property not found in other materials. Dendritic phenylazomethines (DPAs), as one of the rigid dendrimers, have only sp2-type C and N atoms and possess a radially branched π-conjugation system in their own macromolecular chains. Such geometric and electronic structures heighten the electron density at the core of the dendrimer and induce an intramolecular potential gradient, which affords unique reactivities that lead to extraordinary functions. This unique property of the rigid dendrimers can be regarded as a new atypical electronic state based on radial aromatic chains not found in conventional aromatic compounds containing spherical aromaticity, Möbius aromaticity, metal aromaticity, and conductive polymers. Therefore, this as-yet-unknown characteristic is expected to contribute to the further development of fundamental and materials chemistry.In this Account, we highlight the rigid DPA dendrimers and their peculiar atomically precise and selective assembly behaviors that originate from the radial aromatic chains. One of the most noteworthy attainments based on the radial aromatic chains is the precise synthesis of a multimetallic multinuclear complex of a dendrimer containing a total of 13 elements. Next, we describe the electrochemical and catalytic functionalization of such multinuclear dendrimer complexes and the construction of supramolecular nanoarchitectures by the polymerization of DPAs. These complexes exhibit encapsulation-release switching of guests and additive-free catalytic ability similar to proteins and enzymes. Such selective and accurate control of the intramolecular assembly of guests and the intermolecular arrangement of hosts realized by the radial aromatic chains of dendrimers will enable supramolecular chemistry and biochemistry to be linked from a new aspect. In addition, the multimetallic multinuclear complexes of dendrimers afford a novel approach to precisely synthesize sub-nanoparticles with ultrasmall particle sizes (1 nm) that have been technically difficult to obtain by conventional nanotechnology. We discuss the method for the synthesis of these sub-nanoparticles with well-controlled atomicity and composition using DPA complexes as a template and recent advances to reveal their specific physical and chemical properties. These results suggest that the unique electronic states induced in such radial aromatics could play an important role in the development of next-generation chemistry.
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Affiliation(s)
- Takamasa Tsukamoto
- Laboratory for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology, Yokohama 226-8503 Japan
- PRESTO, JST, Kawaguchi, Saitama 332-0012 Japan
- ERATO, JST, Kawaguchi, Saitama 332-0012 Japan
| | - Takane Imaoka
- Laboratory for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology, Yokohama 226-8503 Japan
- ERATO, JST, Kawaguchi, Saitama 332-0012 Japan
| | - Kimihisa Yamamoto
- Laboratory for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology, Yokohama 226-8503 Japan
- ERATO, JST, Kawaguchi, Saitama 332-0012 Japan
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8
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Affiliation(s)
- Tetsuya Kambe
- Laboratory for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology, 4259 Nagatsutacho, Midori-ku, Yokohama, Kanagawa 226-8503, Japan
- JST-ERATO, Tokyo Institute of Technology, 4259 Nagatsutacho, Midori-ku, Yokohama, Kanagawa 226-8503, Japan
| | - Meijia Li
- Laboratory for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology, 4259 Nagatsutacho, Midori-ku, Yokohama, Kanagawa 226-8503, Japan
| | - Takamasa Tsukamoto
- Laboratory for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology, 4259 Nagatsutacho, Midori-ku, Yokohama, Kanagawa 226-8503, Japan
- JST-ERATO, Tokyo Institute of Technology, 4259 Nagatsutacho, Midori-ku, Yokohama, Kanagawa 226-8503, Japan
- JST-PRESTO, Kawaguchi, Saitama 332-0012, Japan
| | - Takane Imaoka
- Laboratory for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology, 4259 Nagatsutacho, Midori-ku, Yokohama, Kanagawa 226-8503, Japan
- JST-ERATO, Tokyo Institute of Technology, 4259 Nagatsutacho, Midori-ku, Yokohama, Kanagawa 226-8503, Japan
| | - Kimihisa Yamamoto
- Laboratory for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology, 4259 Nagatsutacho, Midori-ku, Yokohama, Kanagawa 226-8503, Japan
- JST-ERATO, Tokyo Institute of Technology, 4259 Nagatsutacho, Midori-ku, Yokohama, Kanagawa 226-8503, Japan
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9
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Takada K, Morita M, Imaoka T, Kakinuma J, Albrecht K, Yamamoto K. Metal atom-guided conformational analysis of single polynuclear coordination molecules. Sci Adv 2021; 7:7/32/eabd9887. [PMID: 34362728 PMCID: PMC8346213 DOI: 10.1126/sciadv.abd9887] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/24/2020] [Accepted: 06/21/2021] [Indexed: 06/13/2023]
Abstract
Microscopic observation of single molecules is a rapidly expanding field in chemistry and differs from conventional characterization techniques that require a large number of molecules. One of such form of single-molecule microscopy is high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM), which is especially suitable for coordination compounds because of its atomic number-dependent contrast. However, to date, single-molecule observations using HAADF-STEM has limited to simple planar molecules. In the present study, we demonstrate a direct structural investigation of nonplanar dendronized polynuclear Ir complexes with subnanometer resolution using Ir as an atomic label. Decreasing the electron dose to the dendrimer complexes is critical for the single-molecule observation. A comparison with simulated STEM images of conformational isomers is performed to determine the most plausible conformation. Our results enlarge the potential of electron microscopic observation to realize structural analysis of coordination macromolecules, which has been impossible with conventional methods.
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Affiliation(s)
- Kenji Takada
- JST ERATO, Yamamoto Atom Hybrid Project, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama 226-8503, Japan
| | - Mari Morita
- JST ERATO, Yamamoto Atom Hybrid Project, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama 226-8503, Japan
| | - Takane Imaoka
- JST ERATO, Yamamoto Atom Hybrid Project, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama 226-8503, Japan.
- Institute of Innovative Research, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama 226-8503, Japan
| | - Junko Kakinuma
- JST ERATO, Yamamoto Atom Hybrid Project, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama 226-8503, Japan
| | - Ken Albrecht
- JST ERATO, Yamamoto Atom Hybrid Project, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama 226-8503, Japan.
- Institute of Innovative Research, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama 226-8503, Japan
| | - Kimihisa Yamamoto
- JST ERATO, Yamamoto Atom Hybrid Project, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama 226-8503, Japan.
- Institute of Innovative Research, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama 226-8503, Japan
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10
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Abstract
Subnanoparticles (SNPs) with sizes of approximately 1 nm are attractive for enhancing the catalytic performance of transition metals and their oxides. Such SNPs are of particular interest as redox-active catalysts in selective oxidation reactions. However, the electronic states and oxophilicity of copper oxide SNPs are still a subject of debate in terms of their redox properties during oxidation reactions for hydrocarbons. In this work, in situ X-ray absorption fine structure (XAFS) measurements of Cu28 Ox SNPs, which were prepared by using a dendritic phenylazomethine template, during temperature-programmed reduction (TPR) with H2 achieved lowering of the temperature (T50 =138 °C) reported thus far for the CuII →CuI reduction reaction because of Cu-O bond elongation in the ultrasmall copper oxide particles.
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Affiliation(s)
- Kazutaka Sonobe
- Laboratory for Chemistry and Life Science, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama, 226-8503, Japan
| | - Makoto Tanabe
- JST-ERATO, Yamamoto Atom Hybrid Project, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama, 226-8503, Japan
| | - Takane Imaoka
- Laboratory for Chemistry and Life Science, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama, 226-8503, Japan.,JST-ERATO, Yamamoto Atom Hybrid Project, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama, 226-8503, Japan
| | - Wang-Jae Chun
- Graduate School of Arts and Sciences, International Christian University, Mitaka, Tokyo, 181-8585, Japan
| | - Kimihisa Yamamoto
- Laboratory for Chemistry and Life Science, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama, 226-8503, Japan.,JST-ERATO, Yamamoto Atom Hybrid Project, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama, 226-8503, Japan
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Sonobe K, Tanabe M, Imaoka T, Chun W, Yamamoto K. Front Cover: Low‐Temperature H
2
Reduction of Copper Oxide Subnanoparticles (Chem. Eur. J. 33/2021). Chemistry 2021. [DOI: 10.1002/chem.202101409] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Kazutaka Sonobe
- Laboratory for Chemistry and Life Science Tokyo Institute of Technology 4259 Nagatsuta Midori-ku, Yokohama 226-8503 Japan
| | - Makoto Tanabe
- JST-ERATO Yamamoto Atom Hybrid Project Tokyo Institute of Technology 4259 Nagatsuta Midori-ku, Yokohama 226-8503 Japan
| | - Takane Imaoka
- Laboratory for Chemistry and Life Science Tokyo Institute of Technology 4259 Nagatsuta Midori-ku, Yokohama 226-8503 Japan
- JST-ERATO Yamamoto Atom Hybrid Project Tokyo Institute of Technology 4259 Nagatsuta Midori-ku, Yokohama 226-8503 Japan
| | - Wang‐Jae Chun
- Graduate School of Arts and Sciences International Christian University Mitaka, Tokyo 181-8585 Japan
| | - Kimihisa Yamamoto
- Laboratory for Chemistry and Life Science Tokyo Institute of Technology 4259 Nagatsuta Midori-ku, Yokohama 226-8503 Japan
- JST-ERATO Yamamoto Atom Hybrid Project Tokyo Institute of Technology 4259 Nagatsuta Midori-ku, Yokohama 226-8503 Japan
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12
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Sonobe K, Tanabe M, Imaoka T, Chun WJ, Yamamoto K. Low-Temperature H 2 Reduction of Copper Oxide Subnanoparticles. Chemistry 2021; 27:8410. [PMID: 34050583 DOI: 10.1002/chem.202101410] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Invited for the cover of this issue is Kimihisa Yamamoto and co-workers at Tokyo Institute of Technology and International Christian University. The image depicts enhanced reactivity of the copper oxide subnanoparticles under low-temperature conditions. Read the full text of the article at 10.1002/chem.202100508.
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Affiliation(s)
- Kazutaka Sonobe
- Laboratory for Chemistry and Life Science, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama, 226-8503, Japan
| | - Makoto Tanabe
- JST-ERATO, Yamamoto Atom Hybrid Project, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama, 226-8503, Japan
| | - Takane Imaoka
- Laboratory for Chemistry and Life Science, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama, 226-8503, Japan.,JST-ERATO, Yamamoto Atom Hybrid Project, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama, 226-8503, Japan
| | - Wang-Jae Chun
- Graduate School of Arts and Sciences, International Christian University, Mitaka, Tokyo, 181-8585, Japan
| | - Kimihisa Yamamoto
- Laboratory for Chemistry and Life Science, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama, 226-8503, Japan.,JST-ERATO, Yamamoto Atom Hybrid Project, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama, 226-8503, Japan
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13
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Wakizaka M, Imaoka T, Yamamoto K. Highly Dispersed Molybdenum Oxycarbide Clusters Supported on Multilayer Graphene for the Selective Reduction of Carbon Dioxide. Small 2021; 17:e2008127. [PMID: 33760388 DOI: 10.1002/smll.202008127] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/27/2020] [Revised: 02/02/2021] [Indexed: 06/12/2023]
Abstract
Molybdenum oxycarbide clusters are novel nanomaterials that exhibit attractive catalytic activity; however, the methods for their production are currently very restrictive. This work represents a new strategy for the creation of near-subnanometer size molybdenum oxycarbide clusters on multilayer graphene. To adsorb Mo-based polyoxometalates of the type [PMo12 O40 ]3- as a precursor for Mo oxycarbide clusters, the novel tripodal-phenyl cation N,N,N-tri(4-phenylbutyl)-N-methylammonium ([TPBMA]+ ) is synthesized. [TPBMA]+ exhibits superior adsorption on multilayer graphene compared to commercially available cations such as tetrabutylammonium ([nBu4 N]+ ) and tetraphenylphosphonium ([PPh4 ]+ ). Using [TPBMA]+ as an anchor, highly dispersed precursor clusters (diameter: 1.0 ± 0.2 nm) supported on multilayer graphene are obtained, as confirmed by high-resolution scanning transmission electron microscopy. Remarkably, this new material achieves the catalytic reduction of CO2 to selectively produce CO (≈99.9%) via the reverse water-gas-shift reaction, by applying carbothermal hydrogen reduction to generate Mo oxycarbide clusters in situ.
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Affiliation(s)
- Masanori Wakizaka
- Laboratory for Chemistry and Life Science Institute of Innovative Research, Tokyo Institute of Technology, Yokohama, 226-8503, Japan
| | - Takane Imaoka
- Laboratory for Chemistry and Life Science Institute of Innovative Research, Tokyo Institute of Technology, Yokohama, 226-8503, Japan
| | - Kimihisa Yamamoto
- Laboratory for Chemistry and Life Science Institute of Innovative Research, Tokyo Institute of Technology, Yokohama, 226-8503, Japan
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Abstract
For decades, chemists have explored cluster compounds according to theoretical models that have proved too simplistic to accurately predict cluster properties, stabilities and functions. By incorporating molecular symmetry into existing cluster models, we can better study real polyatomic molecules and have new guidelines for their design. This symmetry-adapted cluster model allows us to discover substances that shatter the conventional notion of clusters. Theoretical predictors will point to the viability of new clusters, whose syntheses can be realized with parallel advances in experimental methods. This Perspective describes these modern experimental and theoretical strategies for cluster design and how they may give rise to new fields in cluster chemistry.
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Akanuma Y, Imaoka T, Sato H, Yamamoto K. Silver in the Center Enhances Room‐Temperature Phosphorescence of a Platinum Sub‐nanocluster by 18 Times. Angew Chem Int Ed Engl 2021. [DOI: 10.1002/ange.202012921] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Affiliation(s)
- Yuki Akanuma
- Institute of Innovative Research Tokyo Institute of Technology 4269 Nagatsuta, Midori-ku Yokohama 226-8503 Japan
| | - Takane Imaoka
- Institute of Innovative Research Tokyo Institute of Technology 4269 Nagatsuta, Midori-ku Yokohama 226-8503 Japan
- JST-ERATO, Yamamoto Atom Hybrid Project Tokyo Institute of Technology 4269 Nagatsuta, Midori-ku Yokohama 226-8503 Japan
| | - Hiroyasu Sato
- Rigaku Corporation 3-9-12, Matsubara-cho Akishima-shi 196-8666 Japan
| | - Kimihisa Yamamoto
- Institute of Innovative Research Tokyo Institute of Technology 4269 Nagatsuta, Midori-ku Yokohama 226-8503 Japan
- JST-ERATO, Yamamoto Atom Hybrid Project Tokyo Institute of Technology 4269 Nagatsuta, Midori-ku Yokohama 226-8503 Japan
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16
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Akanuma Y, Imaoka T, Sato H, Yamamoto K. Silver in the Center Enhances Room-Temperature Phosphorescence of a Platinum Sub-nanocluster by 18 Times. Angew Chem Int Ed Engl 2021; 60:4551-4554. [PMID: 33200557 DOI: 10.1002/anie.202012921] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2020] [Revised: 10/29/2020] [Indexed: 12/11/2022]
Abstract
There has been controversy surrounding the roles of the metal core (metal-metal interaction) and the shell (metal-ligand interaction) in photoluminescence of ligand-protected metal nanoclusters. We have discovered aggregation-induced room-temperature phosphorescence of a platinum-thiolate complex and its silver ion inclusion complex (a silver-doped platinum sub-nanocluster). The inclusion of silver ion boosted the photoluminescent quantum yield by 18 times. Photophysical measurements indicate that the rate of nonradiative decay was slower for the silver-doped platinum sub-nanocluster. DFT calculations showed that the LUMO, which had the main contribution from Ag s-orbital and Pt d-orbitals, played a critical role in suppressing the structural distortion at the excited state. This work will hopefully stimulate more research on designing strategies based on molecular orbitals of atomicity-precise luminescent multimetallic nanoclusters.
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Affiliation(s)
- Yuki Akanuma
- Institute of Innovative Research, Tokyo Institute of Technology, 4269 Nagatsuta, Midori-ku, Yokohama, 226-8503, Japan
| | - Takane Imaoka
- Institute of Innovative Research, Tokyo Institute of Technology, 4269 Nagatsuta, Midori-ku, Yokohama, 226-8503, Japan.,JST-ERATO, Yamamoto Atom Hybrid Project, Tokyo Institute of Technology, 4269 Nagatsuta, Midori-ku, Yokohama, 226-8503, Japan
| | - Hiroyasu Sato
- Rigaku Corporation, 3-9-12, Matsubara-cho, Akishima-shi, 196-8666, Japan
| | - Kimihisa Yamamoto
- Institute of Innovative Research, Tokyo Institute of Technology, 4269 Nagatsuta, Midori-ku, Yokohama, 226-8503, Japan.,JST-ERATO, Yamamoto Atom Hybrid Project, Tokyo Institute of Technology, 4269 Nagatsuta, Midori-ku, Yokohama, 226-8503, Japan
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17
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Wakizaka M, Chun W, Imaoka T, Yamamoto K. Multiple‐Oxidation‐State Tungsten‐Oxide Clusters on a Carbon Surface as an Intersection between Molecular and Bulk Oxides. Eur J Inorg Chem 2021. [DOI: 10.1002/ejic.202001104] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Affiliation(s)
- Masanori Wakizaka
- Laboratory for Chemistry and Life Science Institute of Innovative Research Tokyo Institute of Technology Yokohama 226-8503 Japan
| | - Wang‐Jae Chun
- Graduate School of Arts and Sciences International Christian University Tokyo 181-8585 Japan
| | - Takane Imaoka
- Laboratory for Chemistry and Life Science Institute of Innovative Research Tokyo Institute of Technology Yokohama 226-8503 Japan
| | - Kimihisa Yamamoto
- Laboratory for Chemistry and Life Science Institute of Innovative Research Tokyo Institute of Technology Yokohama 226-8503 Japan
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18
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Wakizaka M, Chun WJ, Imaoka T, Yamamoto K. Metallic Tungsten Nanoparticles That Exhibit an Electronic State Like Carbides during the Carbothermal Reduction of WCl 6 by Hydrogen. Inorg Chem 2020; 59:15690-15695. [PMID: 33085886 DOI: 10.1021/acs.inorgchem.0c01930] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Carbothermal hydrogen reduction (CHR) is a unique dry chemical process used to fabricate metals and carbides on carbon supports. In this study, a stepwise CHR of WCl6 on a graphite support is demonstrated for the first time. Powder X-ray diffraction studies revealed that, at 773 K, metallic tungsten nanoparticles are produced, whereas, at 1073 K, the metastable W2C phase is generated rather than the thermodynamically stable WC phase. X-ray photoelectron spectroscopy and X-ray absorption near edge structure studies showed that the chemical state of the W nanoparticles simultaneously exhibits metallic W(∼0) and carbide W(δ+) character. The obtained results suggest that, although electronic interactions exist between the metallic W atoms and the graphite support, the body-centered cubic structure of the metallic tungsten is maintained, confirmed by the extended X-ray absorption fine structure. In addition, high-resolution scanning transmission electron microscopy observations revealed that the W nanoparticles exhibit a thin flattened shape on the support. These results support the notion that the mechanism for the formation of the W nanoparticles during the CHR is influenced by the electronic interactions between the W nanoparticles and the graphite support. Our work thus suggests that the combination of early-transition-metal atoms and carbon-based supports would afford modulatable electronic systems though the electronic interactions.
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Affiliation(s)
- Masanori Wakizaka
- Laboratory for Chemistry and Life Science Institute of Innovative Research, Tokyo Institute of Technology, Yokohama 226-8503, Japan
| | - Wang-Jae Chun
- Graduate School of Arts and Sciences, International Christian University, Tokyo 181-8585, Japan
| | - Takane Imaoka
- Laboratory for Chemistry and Life Science Institute of Innovative Research, Tokyo Institute of Technology, Yokohama 226-8503, Japan
| | - Kimihisa Yamamoto
- Laboratory for Chemistry and Life Science Institute of Innovative Research, Tokyo Institute of Technology, Yokohama 226-8503, Japan
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19
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Imaoka T, Umemoto N, Oshima S. Hemodialysis patients with better coronary flow reserve and nutrition status have surprising prognosis. Eur Heart J 2020. [DOI: 10.1093/ehjci/ehaa946.1269] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Abstract
Background
In clinical setting, ischemic heart disease is a challenging problem in hemodialysis (HD) population. Coronary flow reserve (CFR) measured by 13 ammonia positron emitting tomography (13NH3PET) is an established and reliable modality for detecting coronary artery disease. Furthermore, some prior studies show CFR is an important and independent predictor for cardiovascular event and mortality. On the other hand, HD patients with malnutrition status have poor prognosis. We have reported about the relationship between cardiovascular events and geriatric nutrition risk index (GNRI). Now, we wonder the predictability of combination of CFR and GNRI.
Methods and result
We collected 438 consecutive HD patients who received 13NH3PET in our hospital suspected for ischemic heart disease. 29 patients were excluded due to undergoing coronary revascularization within 60 days, 103 patients were excluded due to incomplete database. In total, 306 HD patients were classified into 4 group according the median value of CFR (1.99) and GNRI (97.73); Low CFR Low GNRI group (n=77), High CFR and Low GNRI group (n=76), Low CFR High GNRI group (n=78) and High CFR High GNRI group (n=75). We collected their follow up data up to 1544 days (median 833 days) about all-cause mortality and cardiovascular (CV) mortality. Surprisingly, there is no mortality event in High CFR High GNRI group. We analyzed about all-cause mortality, CV mortality. Kaplan-Meyer analysis shows there are statistically intergroup differences in each (all-cause mortality; log rank p<0.01, CV mortality; log rank p=0.02). Furthermore, we calculated area under the curve (AUC) analysis, net reclassification improvement (NRI) and integrated discrimination improvement (IDI)m adding GNRI and CFR on conventional risk factors. There are intergroup differences for all-cause mortality in AUC [conventional risk factors, +GNRI, +GNRI+CFR; 0.70, 0.72 (p=0.29), 0.79 (p<0.01)], NRI [+GNRI; 0.32 (p=0.04), +GNRI+CFR 0.82 (p<0.01)] and IDI [+GNRI; 0.01 (p=0.05), +GNRI+CFR 0.09 (p<0.01)].
Conclusion
HD patients with low CFR and malnutrition status has statistically significant poorer prognosis comparing HD patients with high CFR and without malnutrition status. Adding combination of GNRI and CFR on conventional risk factors improves the predictability of HD population's prognosis.
Funding Acknowledgement
Type of funding source: None
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Affiliation(s)
- T Imaoka
- Ichinomiya municipal hospital, cardiology, Ichinomiya, Japan
| | - N Umemoto
- Ichinomiya municipal hospital, cardiology, Ichinomiya, Japan
| | - S Oshima
- Nagoya Kyoritsu Hospital, cardiology, Nagoya, Japan
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20
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Umemoto N, Imaoka T, Inoue S, Oshima S, Itou R, Sakakibara T, Shimizu K, Ishii H, Murohara T. Impact of stress myocardial blood flow as an important predictor for major adverse cardiac and cerebrovascular event in hemodialysis patients, even in patients without myocardial perfusion abnormality. Eur Heart J 2020. [DOI: 10.1093/ehjci/ehaa946.0312] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Abstract
Background
In the clinical setting, ischemic heart disease (IHD) is a major problem not only in general patients but also in regular hemodialysis (HD) patients. Positron emission tomography (PET) is becoming a reliable modality for detecting coronary artery disease. Of course, PET illustrates myocardial perfusion (MP), PET also measures myocardial blood flow (MBF) directly. We have reported stress MBF is an independent predictor in HD population. Although some prior studies show CFR is an independent predictor for their prognosis in patients without MP abnormality, there is limited data about the predictability of stress MBF in HD patients without MP abnormality.
Methods
A total 438 of HD patients who undergone 13NH3PET for suspected IHD were enrolled. All patients were undergone13NH3PET at Nagoya Radiological Diagnosis Foundation. After we excluded patients whose summed stress score (SSS) <4, we identified 182 eligible patients. Patients were divided into two group according to the median value of CFR levels; low stress MBF group (≤2.56) and high stress MBF group (>2.56). We followed up them up to 4.2 years (median 2.4 years) and collected their data. We evaluated their major adverse cardiac cerebrovascular event. We performed Kaplan-Meyer analysis and multivariable cox regression models. Furthermore, we evaluated the incremental value with C-index, net reclassification improvement (NRI) and integrated discrimination improvement (IDI) when CFR added into a model with established risk factors.
Result
There were intergroup difference in baseline characteristics: age, gender, prior CVD and diabetes. Kaplan-Meyer analysis shows statistically intergroup difference [log rank p=0.013, hazard ratio (HR) 0.413, 95% confidential interval (CI) 0.220–0.775]. Multivariable cox regression model for MACCE shows CFR is an independent risk factor (p=0.004, HR 0.311, 95% CI 0.137–0.684). As regarding model discrimination, all of C-index (0.832 vs 0.796, p=0.15), NRI (0.513, p=0.008) and IDI (0.032, p=0.033) were greatest in a predicting model with established risk factors plus stress MBF.
Conclusion
The low stress MBF group has poor prognosis in MACCE comparing to the high stress MBF group. Stress MBF is an independent risk factor for MACCE. Adding stress MBF on conventional risk factors could more accurately predict MACCE in HD patients, even in patients without MP abnormality.
Funding Acknowledgement
Type of funding source: None
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Affiliation(s)
- N Umemoto
- Ichinomiya Municipal Hospital, Ichinomiya, Japan
| | - T Imaoka
- Ichinomiya Municipal Hospital, Ichinomiya, Japan
| | - S Inoue
- Ichinomiya Municipal Hospital, Ichinomiya, Japan
| | - S Oshima
- Kyoritsu Hospital, department of cardiology, Nagoya, Japan
| | - R Itou
- Kyoritsu Hospital, department of cardiology, Nagoya, Japan
| | - T Sakakibara
- Kyoritsu Hospital, department of cardiology, Nagoya, Japan
| | - K Shimizu
- Ichinomiya Municipal Hospital, Ichinomiya, Japan
| | - H Ishii
- Nagoya University Hospital, department of cardiology, Nagoya, Japan
| | - T Murohara
- Nagoya University Hospital, department of cardiology, Nagoya, Japan
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21
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Umemoto N, Imaoka T, Inoue S, Itou R, Oshima S, Sakakibara T, Shimizu K, Ishii H, Murohara T. Diabetes and hemodialysis are important factor for decrease coronary flow reserve even in the patients with normal myocardial perfusion. Eur Heart J 2020. [DOI: 10.1093/ehjci/ehaa946.0293] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Abstract
Background
In clinical setting, patients with traditional coronary risk factors are at high risk for coronary artery disease (CAD). Such patients who complain chest discomfort are usually performed nuclear myocardial perfusion (MP) test. We sometimes find patients whose PET result shows normal MP and abnormal coronary flow reserve (CFR). However, there are limited data about the predictors for decreased CFR. In the view of describe above, we have investigated the parameters for decreased CFR in the patients without MP abnormality.
Methods and results
From 20th April 2013 to 21st December 2018, we performed 2,930 13N- ammonia PET for suspected CAD. After excluding the follows; 966 patients with repeated test, 54 patients with incomplete data, one patient missed, we investigated 1,909 eligible patients' data. We performed least square to identify the factors decreased CFR. Hemodialysis (HD), age, prior revascularization, diabetes (DM) and body mass index (BMI) were independent risk factor for decreased CFR in all population. On the other hand, HD, age, DM, hypertension and BMI were independent risk factor for decreasing CFR in patients without MP abnormality. According to the result of least square methods, we classified all patients into four groups; without DM/ without HD group, with DM/ without HD group, without DM/ with HD group and with DM/ with HD group. The value of CFR in each group were as follows: without DM/ without HD group (median, 1st quartile-3rd quartile; 2.88, 2.21–3.52), with DM/ without HD group (2.65, 2.00–3.38), without DM/ with HD group (2.29, 1.67–2.95) and with DM/ with HD group (1.97, 1.43–2.68). There were statistically significant intergroup differences. The value of CFR in the patients without MP abnormality were as follows: without DM/ without HD group (3.04, 2.47–3.65), with DM/ without HD group (2.98, 2.40–3.61), without DM/ with HD group (2.52, 2.10–3.08) and with DM/ with HD group (2.38, 1.86–2.97). Even in the patients without MP abnormality, there were also statistically significant intergroup differences.
Conclusion
According to our 13N-ammonia PET data analysis, DM and HD were important and independent factors for decreased CFR. Even in the patients without MP abnormality, DM and HD were important factor for decreased CFR.
Funding Acknowledgement
Type of funding source: None
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Affiliation(s)
- N Umemoto
- Ichinomiya Municipal Hospital, Ichinomiya, Japan
| | - T Imaoka
- Ichinomiya Municipal Hospital, Ichinomiya, Japan
| | - S Inoue
- Ichinomiya Municipal Hospital, Ichinomiya, Japan
| | - R Itou
- Kyoritsu Hospital, department of cardiology, Nagoya, Japan
| | - S Oshima
- Kyoritsu Hospital, department of cardiology, Nagoya, Japan
| | - T Sakakibara
- Kyoritsu Hospital, department of cardiology, Nagoya, Japan
| | - K Shimizu
- Ichinomiya Municipal Hospital, Ichinomiya, Japan
| | - H Ishii
- Nagoya University Hospital, department of cardiology, Nagoya, Japan
| | - T Murohara
- Nagoya University Hospital, department of cardiology, Nagoya, Japan
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22
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Yamauchi R, Morishima I, Morita Y, Takagi K, Nagai H, Kanzaki Y, Watanabe N, Komeyama S, Sugiyama H, Shimojo K, Imaoka T, Sakamoto G. Catheter ablation of atrial fibrillation benefits the patients with heart failure and preserved ejection fraction as well as those with heart failure and reduced ejection fraction. Eur Heart J 2020. [DOI: 10.1093/ehjci/ehaa946.0430] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Abstract
Background
Although catheter ablation of atrial fibrillation (AF) has recently been shown to improve the cardiac function and even mortality in patients with heart failure (HF) and reduced ejection fraction (HFrEF), few studies have examined the outcomes of AF catheter ablation in patients with HF with preserved ejection fraction (HFpEF).
Purpose
To verify the impact of AF catheter ablation on the cardiac function and HF status in patients with HFpEF.
Methods
We studied 306 patients with HF who had a history of an HF hospitalization and/or preprocedural serum BNP levels >100pg/ml (age, 68.9±8.2 years old; male, 66.3%; non-paroxysmal AF, 63.1%, left atrial diameter [LAD], 42.5±6.3 mm; left ventricular ejection fraction [LVEF], 60.6±12.0%) out of 596 consecutive patients who underwent pulmonary vein isolation-based catheter ablation of AF. The patients with an LVEF ≥50% were defined as having HFpEF (n=262; age, 69.0±8.2 years old; male, 64.5%; non-paroxysmal AF, 61.8%, LAD, 42.1±5.9 mm; left LVEF, 64.0±8.2%) and the remaining patients with an LVEF <50% were defined as having HFrEF (n=44, age, 67.9±8.7 years old; male, 77.0%; non-paroxysmal AF, 70.5%, LAD, 44.9±8.2 mm; LVEF, 40.1±10.2%). The patients received periodic follow-ups for 12 months after the catheter ablation. The cardiac function parameters including the echocardiographic findings and HF functional status of the patients were compared between baseline and 12 months, stratified by the HF subgroup.
Results
AF recurred in 60 patients with HFpEF (22.9%) and in 14 with HFrEF (31.8%) during the 12 month follow-up (p=0.27), however, sinus rhythm was maintained at 12 months in most of the patients (253 patients with HFpEF [96.6%] and 42 patients with HFrEF [95.5%]) (p=0.71). Figure 1 compares the changes in the cardiac function parameters and NYHA functional class from baseline to the 12-month follow-up stratified by the HF subgroup. Both the patients with HFpEF and HFrEF had significant improvements in the serum BNP levels, chest thorax ratio, and LVEF determined by echocardiography. LA reverse remodeling as shown by a significant reduction in the LAD was observed in both HF subgroups, however, the E/E', an index of the LV diastolic function, did not significantly change in either of the subgroups. Similar to the patients with HFrEF, an improvement in the NYHA functional class was seen in those with HFpEF.
Conclusions
Catheter ablation of AF may benefit patients with HFpEF as well as those with HFrEF. Sinus rhythm maintenance achieved by AF catheter ablation in patients with HFpEF may lead to LA reverse remodeling and a better LV systolic function, thereby improving the NYHA functional class. It is unclear whether changes in the LV diastolic function may contribute to this favorable process.
Funding Acknowledgement
Type of funding source: None
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Affiliation(s)
| | | | - Y Morita
- Ogaki Municipal Hospital, Ogaki, Japan
| | - K Takagi
- Ogaki Municipal Hospital, Ogaki, Japan
| | - H Nagai
- Ogaki Municipal Hospital, Ogaki, Japan
| | - Y Kanzaki
- Ogaki Municipal Hospital, Ogaki, Japan
| | | | | | | | - K Shimojo
- Ogaki Municipal Hospital, Ogaki, Japan
| | - T Imaoka
- Ogaki Municipal Hospital, Ogaki, Japan
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Abstract
Ultrasmall particles exhibit structures and/or properties that are different from those of the corresponding bulk materials; in this context especially ultrasmall precious-metal particles have been extensively investigated. In this study, we targeted the transition base-metal Mo and succeeded in systematically producing Mo oxycarbide/carbide particles with diameters of 1.7 ± 0.7, 1.4 ± 0.5, 1.3 ± 0.4, 1.2 ± 0.3, 1.0 ± 0.3, and 0.8 ± 0.2 nm on a carbon support using the carbothermal hydrogen reduction method at 773 K and a diphenylazomethine-type dendrimer as a template. The formation and properties of the particles were confirmed using X-ray photoelectron spectroscopy, high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM) images, and X-ray absorption fine structure (XAFS) studies. We found that Mo particles with a diameter of 1.3 nm or greater formed carbides such as β'-Mo2C, whereas smaller particles formed oxycarbides, indicating a size-dependent transformation in the phase or composition of the particles. Thus, this work demonstrated a new concept, subnano-transformation, which would be a new class of phase transformation based on the concept of the size dependence in such an ultrasmall scale. In addition, the movement of Mo atoms within a cluster and on the fringes of a nanoparticle was also demonstrated during continuous time-course high-resolution HAADF-STEM observation.
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Affiliation(s)
- Masanori Wakizaka
- Laboratory for Chemistry and Life Science Institute of Innovative Research, Tokyo Institute of Technology, Yokohama 226-8503, Japan.
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24
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Affiliation(s)
- Masanori Wakizaka
- Laboratory for Chemistry and Life Science Institute of Innovative Research Tokyo Institute of Technology Yokohama 226‐8503 Japan
| | - Hisanori Muramatsu
- Laboratory for Chemistry and Life Science Institute of Innovative Research Tokyo Institute of Technology Yokohama 226‐8503 Japan
| | - Takane Imaoka
- Laboratory for Chemistry and Life Science Institute of Innovative Research Tokyo Institute of Technology Yokohama 226‐8503 Japan
| | - Kimihisa Yamamoto
- Laboratory for Chemistry and Life Science Institute of Innovative Research Tokyo Institute of Technology Yokohama 226‐8503 Japan
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25
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Applegate KE, Rühm W, Wojcik A, Bourguignon M, Brenner A, Hamasaki K, Imai T, Imaizumi M, Imaoka T, Kakinuma S, Kamada T, Nishimura N, Okonogi N, Ozasa K, Rübe CE, Sadakane A, Sakata R, Shimada Y, Yoshida K, Bouffler S. Individual response of humans to ionising radiation: governing factors and importance for radiological protection. Radiat Environ Biophys 2020; 59:185-209. [PMID: 32146555 DOI: 10.1007/s00411-020-00837-y] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/15/2019] [Accepted: 02/26/2020] [Indexed: 05/23/2023]
Abstract
Tissue reactions and stochastic effects after exposure to ionising radiation are variable between individuals but the factors and mechanisms governing individual responses are not well understood. Individual responses can be measured at different levels of biological organization and using different endpoints following varying doses of radiation, including: cancers, non-cancer diseases and mortality in the whole organism; normal tissue reactions after exposures; and, cellular endpoints such as chromosomal damage and molecular alterations. There is no doubt that many factors influence the responses of people to radiation to different degrees. In addition to the obvious general factors of radiation quality, dose, dose rate and the tissue (sub)volume irradiated, recognized and potential determining factors include age, sex, life style (e.g., smoking, diet, possibly body mass index), environmental factors, genetics and epigenetics, stochastic distribution of cellular events, and systemic comorbidities such as diabetes or viral infections. Genetic factors are commonly thought to be a substantial contributor to individual response to radiation. Apart from a small number of rare monogenic diseases such as ataxia telangiectasia, the inheritance of an abnormally responsive phenotype among a population of healthy individuals does not follow a classical Mendelian inheritance pattern. Rather it is considered to be a multi-factorial, complex trait.
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Affiliation(s)
| | - W Rühm
- Helmholtz Center Munich, German Research Center for Environmental Health, Institute of Radiation Medicine, Neuherberg, Germany
| | - A Wojcik
- Centre for Radiation Protection Research, MBW Department, Stockholm University, Stockholm, Sweden
| | - M Bourguignon
- Department of Biophysics and Nuclear Medicine, University of Paris Saclay (UVSQ), Verseilles, France
| | - A Brenner
- Department of Epidemiology, Radiation Effects Research Foundation, Hiroshima, Japan
| | - K Hamasaki
- Department of Molecular Biosciences, Radiation Effects Research Foundation, Hiroshima, Japan
| | - T Imai
- National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Sciences and Technology, Chiba, Japan
| | - M Imaizumi
- Department of Nagasaki Clinical Studies, Radiation Effects Research Foundation, Nagasaki, Japan
| | - T Imaoka
- Department of Radiation Effects Research, National Institute of Radiological Sciences, National Institute for Quantum and Radiological Science and Technology, Chiba, Japan
| | - S Kakinuma
- Department of Radiation Effects Research, National Institute of Radiological Sciences, National Institute for Quantum and Radiological Science and Technology, Chiba, Japan
| | - T Kamada
- QST Hospital, National Institute of Radiological Sciences, National Institute for Quantum and Radiological Science and Technology, Chiba, Japan
| | - N Nishimura
- Department of Radiation Effects Research, National Institute of Radiological Sciences, National Institute for Quantum and Radiological Science and Technology, Chiba, Japan
| | - N Okonogi
- QST Hospital, National Institute of Radiological Sciences, National Institute for Quantum and Radiological Science and Technology, Chiba, Japan
| | - K Ozasa
- Department of Epidemiology, Radiation Effects Research Foundation, Hiroshima, Japan
| | - C E Rübe
- Department of Radiation Oncology, Saarland University Medical Center, Homburg/Saar, Germany
| | - A Sadakane
- Department of Epidemiology, Radiation Effects Research Foundation, Hiroshima, Japan
| | - R Sakata
- Department of Epidemiology, Radiation Effects Research Foundation, Hiroshima, Japan
| | - Y Shimada
- National Institute for Quantum and Radiological Science and Technology, Chiba, Japan
- Institute for Environmental Sciences, Aomori, Japan
| | - K Yoshida
- Immunology Laboratory, Department of Molecular Biosciences, Radiation Effects Research Foundation, Hiroshima, Japan
| | - S Bouffler
- Radiation Effects Department, Centre for Radiation, Chemical and Environmental Hazards, Public Health England, Chilto, Didcot, UK
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26
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Kambe T, Watanabe A, Li M, Tsukamoto T, Imaoka T, Yamamoto K. Superatomic Gallium Clusters in Dendrimers: Unique Rigidity and Reactivity Depending on their Atomicity. Adv Mater 2020; 32:e1907167. [PMID: 32080936 DOI: 10.1002/adma.201907167] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/01/2019] [Revised: 12/24/2019] [Indexed: 06/10/2023]
Abstract
Superatoms have been investigated due to their possible substitution for other elements. The solution-phase synthesis of superatoms has attracted attention to realize the availability of superatoms. However, the previous approach is basically limited to the formation of a single cluster. Here, superatoms are investigated and the number of valence electrons in these superatoms is changed by designing the number of gallium atoms present. Based on the dendrimer template method, clusters consisting of 3, 12, 13, and other numbers of atoms have been synthesized. The halogen-like superatomic nature of Ga13 is structurally and electrochemically observed as completely different to the other clusters. The gallium clusters of 13 and 3 atoms, which can fill the 2P and 1P superatomic orbitals, respectively, exhibit different reactivities. The 3-atom gallium cluster is suggested as being reduced to Ga3 H2 - due to the lower shift of energy levels in the unoccupied orbitals. The results for these gallium clusters provide candidates for superatoms.
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Affiliation(s)
- Tetsuya Kambe
- Laboratory for Chemistry and Life Science, Tokyo Institute of Technology, 4259 Nagatsutacho, Midori-ku, Yokohama, 226-8503, Japan
- ERATO Japan Science and Technology (JST), 4259 Nagatsutacho, Midori-ku, Yokohama, 226-8503, Japan
| | - Aiko Watanabe
- Laboratory for Chemistry and Life Science, Tokyo Institute of Technology, 4259 Nagatsutacho, Midori-ku, Yokohama, 226-8503, Japan
| | - Meijia Li
- Laboratory for Chemistry and Life Science, Tokyo Institute of Technology, 4259 Nagatsutacho, Midori-ku, Yokohama, 226-8503, Japan
| | - Takamasa Tsukamoto
- Laboratory for Chemistry and Life Science, Tokyo Institute of Technology, 4259 Nagatsutacho, Midori-ku, Yokohama, 226-8503, Japan
- ERATO Japan Science and Technology (JST), 4259 Nagatsutacho, Midori-ku, Yokohama, 226-8503, Japan
| | - Takane Imaoka
- Laboratory for Chemistry and Life Science, Tokyo Institute of Technology, 4259 Nagatsutacho, Midori-ku, Yokohama, 226-8503, Japan
- ERATO Japan Science and Technology (JST), 4259 Nagatsutacho, Midori-ku, Yokohama, 226-8503, Japan
| | - Kimihisa Yamamoto
- Laboratory for Chemistry and Life Science, Tokyo Institute of Technology, 4259 Nagatsutacho, Midori-ku, Yokohama, 226-8503, Japan
- ERATO Japan Science and Technology (JST), 4259 Nagatsutacho, Midori-ku, Yokohama, 226-8503, Japan
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Ida Y, Okazawa A, Sonobe K, Muramatsu H, Kambe T, Imaoka T, Chun WJ, Tanabe M, Yamamoto K. A useful preparation of ultrasmall iron oxide particles by using arc plasma deposition. RSC Adv 2020; 10:41523-41531. [PMID: 35516573 PMCID: PMC9057782 DOI: 10.1039/d0ra07443h] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2020] [Accepted: 11/06/2020] [Indexed: 11/21/2022] Open
Abstract
Ultrasmall particles, different from the larger size nanoparticles, have recently attracted significant attention in the scientific community in nanotechnology for catalytic, electronic and optical applications; however, their magnetic properties remain unexplored due to the difficult structural analysis. A challenging issue is to develop a preparation method for iron oxide particles (IOPs) with fine size control, and to determine the dependence of magnetic properties on the morphology and crystallinity of the magnetic particles. However, synthetic approaches to obtain IOPs, regarded as one of the new fields of magnetic nanoparticles, have been significantly limited. This article reported a developed synthetic method to prepare IOPs on carbon supports using pulsed arc plasma deposition (APD) in flowing oxygen gas, which clarified the finely-controlled formation of IOPs on graphene nanosheets. Structural characterization of the IOPs revealed the formation of crystalline γ-Fe2O3 ultrasmall particles with oxygen deficiency. The pulsed APD method for IOPs is the first simple and convenient technique to not only prevent significant aggregation and contamination by organic compounds and avoid the need for thermal pretreatment, but also provide uniform crystalline nano-order particles. Finely size-controlled ultrasmall iron oxide particles (IOPs) on graphene nanosheets were usefully prepared by using pulsed arc plasma deposition. The IOPs are composed of a high crystallinity single γ-Fe2O3 component without annealing.![]()
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Affiliation(s)
- Yumi Ida
- JST-ERATO
- Yamamoto Atom Hybrid Project
- Tokyo Institute of Technology
- Yokohama 226-8503
- Japan
| | - Atsushi Okazawa
- Department of Basic Science
- Graduate School of Arts and Sciences
- The University of Tokyo
- Tokyo 153-8902
- Japan
| | - Kazutaka Sonobe
- Laboratory for Chemistry and Life Science
- Tokyo Institute of Technology
- Yokohama 226-8503
- Japan
| | - Hisanori Muramatsu
- Laboratory for Chemistry and Life Science
- Tokyo Institute of Technology
- Yokohama 226-8503
- Japan
| | - Tetsuya Kambe
- JST-ERATO
- Yamamoto Atom Hybrid Project
- Tokyo Institute of Technology
- Yokohama 226-8503
- Japan
| | - Takane Imaoka
- JST-ERATO
- Yamamoto Atom Hybrid Project
- Tokyo Institute of Technology
- Yokohama 226-8503
- Japan
| | - Wang-Jae Chun
- Graduate School of Arts and Sciences
- International Christian University
- Tokyo 181-8585
- Japan
| | - Makoto Tanabe
- JST-ERATO
- Yamamoto Atom Hybrid Project
- Tokyo Institute of Technology
- Yokohama 226-8503
- Japan
| | - Kimihisa Yamamoto
- JST-ERATO
- Yamamoto Atom Hybrid Project
- Tokyo Institute of Technology
- Yokohama 226-8503
- Japan
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28
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Matsunaga H, Machida Y, Nakagawa M, Yamaguchi M, Ogawara Y, Shima Y, Yamagata K, Katsumoto T, Hattori A, Itoh M, Seki T, Nishiya Y, Nakamura K, Suzuki K, Imaoka T, Suzuki M, Sampetrean O, Saya H, Ichimura K, Kitabayashi I. Characterization of a novel BBB-permeable mutant IDH1 inhibitor, DS-1001b. Ann Oncol 2019. [DOI: 10.1093/annonc/mdz243.006] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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29
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Affiliation(s)
- Kimihisa Yamamoto
- Laboratory for Chemistry and Life Science (CLS), Institute of Innovative Research (IIR), Tokyo Institute of Technology, Yokohama 226-8503, Japan
- ERATO-JST Yamamoto Atom Hybrid Project, Tokyo Institute of Technology, Yokohama 226-8503, Japan
| | - Takane Imaoka
- Laboratory for Chemistry and Life Science (CLS), Institute of Innovative Research (IIR), Tokyo Institute of Technology, Yokohama 226-8503, Japan
- ERATO-JST Yamamoto Atom Hybrid Project, Tokyo Institute of Technology, Yokohama 226-8503, Japan
- PRESTO-JST, Kawaguchi 332-0012, Japan
| | - Makoto Tanabe
- Laboratory for Chemistry and Life Science (CLS), Institute of Innovative Research (IIR), Tokyo Institute of Technology, Yokohama 226-8503, Japan
- ERATO-JST Yamamoto Atom Hybrid Project, Tokyo Institute of Technology, Yokohama 226-8503, Japan
| | - Tetsuya Kambe
- Laboratory for Chemistry and Life Science (CLS), Institute of Innovative Research (IIR), Tokyo Institute of Technology, Yokohama 226-8503, Japan
- ERATO-JST Yamamoto Atom Hybrid Project, Tokyo Institute of Technology, Yokohama 226-8503, Japan
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30
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Wakizaka M, Imaoka T, Yamamoto K. Composition-defined nanosized assemblies that contain heterometallic early 4d/5d-transition-metals. Dalton Trans 2019; 48:14261-14268. [PMID: 31408064 DOI: 10.1039/c9dt03094h] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The controlled assembly of early transition metals remains a challenging research target, especially with respect to the generation of heterometallic molecules and nanomaterials. In this study, metal chlorides of the early 4d/5d-transition-metals, i.e., ZrCl4, NbCl5, MoCl5, HfCl4, TaCl5, and WCl6, were stoichiometrically introduced into a tetraphenylmethane-core dendritic-phenylazomethine generation 4 dendrimer in the presence of an optimal amount of organic ligands such as pyridine and 3-chloropyridine. The coordinative interactions between the metal chlorides and the imines in the dendrimers indicated a positive correlation for the Lewis acidity of the metals. Moreover, it was clearly demonstrated for the first time that heterometallic assemblies of defined composition contain four kinds of early 4d/5d-transition-metals, such as TaV, NbV, MoV, and ZrIV, which was confirmed by UV-vis titration, XPS, and HAADF-STEM/EDS measurements. The results of this study should provide access to new routes to produce nanomaterials composed of heterometallic early 4d/5d-transition metals.
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Affiliation(s)
- Masanori Wakizaka
- Laboratory for Chemistry and Life Science Institute of Innovative Research, Tokyo Institute of Technology, Yokohama 226-8503, Japan.
| | - Takane Imaoka
- Laboratory for Chemistry and Life Science Institute of Innovative Research, Tokyo Institute of Technology, Yokohama 226-8503, Japan.
| | - Kimihisa Yamamoto
- Laboratory for Chemistry and Life Science Institute of Innovative Research, Tokyo Institute of Technology, Yokohama 226-8503, Japan.
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31
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Affiliation(s)
- Takane Imaoka
- Laboratory for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology, Yokohama, Kanagawa 226-8503, Japan
- PRESTO-JST, Kawaguchi, Saitama 332-0012, Japan
- ERATO Yamamoto Atom-Hybrid Project, Tokyo Institute of Technology, Yokohama, Kanagawa 226-8503, Japan
| | - Kimihisa Yamamoto
- Laboratory for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology, Yokohama, Kanagawa 226-8503, Japan
- ERATO Yamamoto Atom-Hybrid Project, Tokyo Institute of Technology, Yokohama, Kanagawa 226-8503, Japan
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32
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Imaoka T, Toyonaga T, Morita M, Haruta N, Yamamoto K. Isomerizations of a Pt 4 cluster revealed by spatiotemporal microscopic analysis. Chem Commun (Camb) 2019; 55:4753-4756. [PMID: 30897188 DOI: 10.1039/c9cc00530g] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
We now report the first direct observation of the fluxional nature in which the four-atomic platinum cluster (Pt4) randomly walks through several isomers. Time-lapse analysis by a Cs-corrected transmission electron microscope allowed us to acquire the atomic coordinates at a sub-angstrom space resolution and 0.2 s time resolution for each cluster isomer. The analysis revealed that the isomerization follows a simple first-order kinetic model.
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Affiliation(s)
- Takane Imaoka
- Laboratory for Chemistry and Life Science (CLS), Institute of Innovative Research (IIR), Tokyo Institute of Technology, Yokohama 226-8503, Japan.
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Tsukamoto T, Kambe T, Nakao A, Imaoka T, Yamamoto K. Atom-hybridization for synthesis of polymetallic clusters. Nat Commun 2018; 9:3873. [PMID: 30250189 PMCID: PMC6155219 DOI: 10.1038/s41467-018-06422-8] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2018] [Accepted: 09/04/2018] [Indexed: 12/23/2022] Open
Abstract
The chemistry of metal clusters on the sub-nanometer scale is not yet well understood because metal clusters, especially multimetallic clusters, are difficult to synthesize with control over size and composition. The template synthesis of multimetallic sub-nanoclusters is achieved using a phenylazomethine dendrimer as a macromolecular template. Its intramolecular potential gradient allows the precise uptake of metal precursor complexes containing up to eight elements on the template. The usefulness of this method is demonstrated by synthesizing multimetallic sub-nanoclusters composed of five elements (Ga1In1Au3Bi2Sn6). The size and composition of this cluster can be precisely controlled and the metals involved are alloyed with each other. This approach provides the ability to easily blend different metals in various combinations to create new materials on the sub-nanometer scale, which will lead to the development of a new area in the field of chemistry. Multimetallic clusters are difficult to synthesize with control over elemental composition and organization. Here, the authors use dendrimers to precisely template the formation of five-element sub-nanoclusters, providing an elegant route to otherwise-inaccessible multinary compounds.
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Affiliation(s)
- Takamasa Tsukamoto
- JST-ERATO, Yamamoto Atom Hybrid Project, Institute of Innovative Research, Tokyo Institute of Technology, Yokohama, 226-8503, Japan
| | - Tetsuya Kambe
- JST-ERATO, Yamamoto Atom Hybrid Project, Institute of Innovative Research, Tokyo Institute of Technology, Yokohama, 226-8503, Japan.,Laboratory for Chemistry and Life Science, Tokyo Institute of Technology, Yokohama, 226-8503, Japan
| | - Aiko Nakao
- RIKEN, 2-1 Hirosawa, Wako, Saitama, 351-0198, Japan
| | - Takane Imaoka
- JST-ERATO, Yamamoto Atom Hybrid Project, Institute of Innovative Research, Tokyo Institute of Technology, Yokohama, 226-8503, Japan.,Laboratory for Chemistry and Life Science, Tokyo Institute of Technology, Yokohama, 226-8503, Japan.,JST-PRESTO, 4-1-8 Honcho, Kawaguchi, Saitama, 332-0012, Japan
| | - Kimihisa Yamamoto
- JST-ERATO, Yamamoto Atom Hybrid Project, Institute of Innovative Research, Tokyo Institute of Technology, Yokohama, 226-8503, Japan. .,Laboratory for Chemistry and Life Science, Tokyo Institute of Technology, Yokohama, 226-8503, Japan.
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34
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Affiliation(s)
- Tetsuya Kambe
- Laboratory for Chemistry and Life Science, Tokyo Institute of Technology
- JST-ERATO, Tokyo Institute of Technology
| | - Reina Hosono
- Laboratory for Chemistry and Life Science, Tokyo Institute of Technology
| | - Takane Imaoka
- Laboratory for Chemistry and Life Science, Tokyo Institute of Technology
- JST-ERATO, Tokyo Institute of Technology
| | - Kimihisa Yamamoto
- Laboratory for Chemistry and Life Science, Tokyo Institute of Technology
- JST-ERATO, Tokyo Institute of Technology
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35
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Nishimura M, Imaoka T, Daino K, Takabatake M, Kokubo T, Nishimura Y, Kakinuma S, Shimada Y. PO-118 Impact of parity on neutron-induced mammary cancer risk in sprague-dawley rats. ESMO Open 2018. [DOI: 10.1136/esmoopen-2018-eacr25.643] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
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36
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Imaoka T, Bukeo N, Yamamoto K. Epitaxially Grown Ultra-Flat Self-Assembling Monolayers with Dendrimers. Molecules 2018; 23:E485. [PMID: 29473849 PMCID: PMC6017922 DOI: 10.3390/molecules23020485] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2018] [Revised: 02/13/2018] [Accepted: 02/14/2018] [Indexed: 11/30/2022] Open
Abstract
Mono-molecular films formed by physical adsorption and dendrimer self-assembly were prepared on various substrate surfaces. It was demonstrated that a uniform dendrimer-based monolayer on the subnanometer scale can be easily constructed via simple dip coating. Furthermore, it was shown that an epitaxially grown monolayer film reflecting the crystal structure of the substrate (highly ordered pyrolytic graphite (HOPG)) can also be formed by aligning specific conditions.
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Affiliation(s)
- Takane Imaoka
- Laboratory for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology, Yokohama 225-8503, Japan.
- ERATO, Japan Science and Technology Agency, Chiyoda 102-0076, Japan.
- PRESTO, Japan Science and Technology Agency, Chiyoda 102-8666, Japan.
| | - Noriko Bukeo
- Laboratory for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology, Yokohama 225-8503, Japan.
| | - Kimihisa Yamamoto
- Laboratory for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology, Yokohama 225-8503, Japan.
- ERATO, Japan Science and Technology Agency, Chiyoda 102-0076, Japan.
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37
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Abstract
Superatoms, clusters that mimic the properties of elements different to those of which they are composed, have the potential to serve as building blocks for unprecedented materials with tunable properties. The development of a method for the solution-phase synthesis of superatoms would be an indispensable achievement for the future progress of this research field. Here we report the fabrication of aluminum clusters in solution using a dendrimer template, producing Al13-, which is the most well-known superatom. The Al13- cluster is identified using mass spectrometry and scanning transmission electron microscopy, and X-ray photoelectron spectroscopy is used to measure the binding energies. The superatomic stability of Al13- is demonstrated by evaluating its tendency toward oxidation. In addition, the synthesis of Al13- in solution enables electrochemical measurements, the results of which suggest oxidation of Al13-. This solution-phase synthesis of Al13- superatoms has a significant role for the experimental development of cluster science.
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Affiliation(s)
- Tetsuya Kambe
- Laboratory for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology, Yokohama, 226-8503, Japan
- ERATO-JST, Institute of Innovative Research, Tokyo Institute of Technology, Yokohama, 226-8503, Japan
| | - Naoki Haruta
- ERATO-JST, Institute of Innovative Research, Tokyo Institute of Technology, Yokohama, 226-8503, Japan
| | - Takane Imaoka
- Laboratory for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology, Yokohama, 226-8503, Japan
- ERATO-JST, Institute of Innovative Research, Tokyo Institute of Technology, Yokohama, 226-8503, Japan
- PRESTO-JST, Institute of Innovative Research, Tokyo Institute of Technology, Yokohama, 226-8503, Japan
| | - Kimihisa Yamamoto
- Laboratory for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology, Yokohama, 226-8503, Japan.
- ERATO-JST, Institute of Innovative Research, Tokyo Institute of Technology, Yokohama, 226-8503, Japan.
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38
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Imaoka T, Okada T, Samukawa S, Yamamoto K. Room-Temperature Synthesis of GaN Driven by Kinetic Energy beyond the Limit of Thermodynamics. ACS Appl Mater Interfaces 2017; 9:41629-41633. [PMID: 29135223 DOI: 10.1021/acsami.7b13694] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
The nitridation reaction is significantly important to utilize the unique properties of nitrides and nitrogen-doped materials. However, nitridation generally requires a high temperature or highly reactive reagents (often explosive) because the energies of N-N bond cleavage and nitrogen anion formation (N3-) are very high. We demonstrate the first room-temperature synthesis of GaN directly from GaCl3 by nanoscale atom exchange reaction. Nonequilibrium nitrogen molecules with very high translational energy were used as a chemically stable and safe nitrogen source. The irradiation of molecular nitrogen to the desired reaction area successfully provided a gallium nitride (GaN) nanosheet that exhibited a typical photoluminescence spectrum. Because this process retains the target substrate room temperature and does not involve any photon nor charged ion, it allows damage-less synthesis of the semiconducting metal nitrides, even directly on plastic substrates such as polyethylene terephthalate (PET).
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Affiliation(s)
- Takane Imaoka
- Laboratory for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology , Yokohama 225-8503, Japan
| | | | | | - Kimihisa Yamamoto
- Laboratory for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology , Yokohama 225-8503, Japan
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39
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Kambe T, Imaoka T, Yamamoto K. Insight into the Effect of Dendrimer Structure on Photoluminescence from Assembled Bismuth Complexes. J Inorg Organomet Polym Mater 2017. [DOI: 10.1007/s10904-017-0705-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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40
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Imaoka T, Akanuma Y, Haruta N, Tsuchiya S, Ishihara K, Okayasu T, Chun WJ, Takahashi M, Yamamoto K. Platinum clusters with precise numbers of atoms for preparative-scale catalysis. Nat Commun 2017; 8:688. [PMID: 28947792 PMCID: PMC5613004 DOI: 10.1038/s41467-017-00800-4] [Citation(s) in RCA: 107] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2016] [Accepted: 07/28/2017] [Indexed: 11/21/2022] Open
Abstract
Subnanometer noble metal clusters have enormous potential, mainly for catalytic applications. Because a difference of only one atom may cause significant changes in their reactivity, a preparation method with atomic-level precision is essential. Although such a precision with enough scalability has been achieved by gas-phase synthesis, large-scale preparation is still at the frontier, hampering practical applications. We now show the atom-precise and fully scalable synthesis of platinum clusters on a milligram scale from tiara-like platinum complexes with various ring numbers (n = 5-13). Low-temperature calcination of the complexes on a carbon support under hydrogen stream affords monodispersed platinum clusters, whose atomicity is equivalent to that of the precursor complex. One of the clusters (Pt10) exhibits high catalytic activity in the hydrogenation of styrene compared to that of the other clusters. This method opens an avenue for the application of these clusters to preparative-scale catalysis.The catalytic activity of a noble metal nanocluster is tied to its atomicity. Here, the authors report an atom-precise, fully scalable synthesis of platinum clusters from molecular ring precursors, and show that a variation of only one atom can dramatically change a cluster's reactivity.
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Affiliation(s)
- Takane Imaoka
- Laboratory for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology, Yokohama, 226-8503, Japan.
- ERATO-JST, Saitama, Kawaguchi, 332-0012, Japan.
- PRESTO-JST, Saitama, Kawaguchi, 332-0012, Japan.
| | - Yuki Akanuma
- Laboratory for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology, Yokohama, 226-8503, Japan
| | - Naoki Haruta
- Laboratory for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology, Yokohama, 226-8503, Japan
- ERATO-JST, Saitama, Kawaguchi, 332-0012, Japan
| | - Shogo Tsuchiya
- Laboratory for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology, Yokohama, 226-8503, Japan
| | - Kentaro Ishihara
- Laboratory for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology, Yokohama, 226-8503, Japan
| | - Takeshi Okayasu
- Laboratory for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology, Yokohama, 226-8503, Japan
| | - Wang-Jae Chun
- ERATO-JST, Saitama, Kawaguchi, 332-0012, Japan
- Graduate School of Arts and Sciences, International Christian University, Tokyo, 181-8585, Japan
| | - Masaki Takahashi
- ERATO-JST, Saitama, Kawaguchi, 332-0012, Japan
- Department of Applied Chemistry, Faculty of Engineering, Yamanashi University, Kofu, 400-8501, Japan
| | - Kimihisa Yamamoto
- Laboratory for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology, Yokohama, 226-8503, Japan.
- ERATO-JST, Saitama, Kawaguchi, 332-0012, Japan.
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41
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Takahashi M, Koizumi H, Chun WJ, Kori M, Imaoka T, Yamamoto K. Finely controlled multimetallic nanocluster catalysts for solvent-free aerobic oxidation of hydrocarbons. Sci Adv 2017; 3:e1700101. [PMID: 28782020 PMCID: PMC5529056 DOI: 10.1126/sciadv.1700101] [Citation(s) in RCA: 55] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/10/2017] [Accepted: 06/20/2017] [Indexed: 05/22/2023]
Abstract
The catalytic activity of alloy nanoparticles depends on the particle size and composition ratio of different metals. Alloy nanoparticles composed of Pd, Pt, and Au are widely used as catalysts for oxidation reactions. The catalytic activities of Pt and Au nanoparticles in oxidation reactions are known to increase as the particle size decreases and to increase on the metal-metal interface of alloy nanoparticles. Therefore, multimetallic nanoclusters (MNCs) around 1 nm in diameter have potential as catalysts for oxidation reactions. However, there have been few reports describing the preparation of uniform alloy nanoclusters. We report the synthesis of finely controlled MNCs (around 1 nm) using a macromolecular template with coordination sites arranged in a gradient of basicity. We reveal that Cu-Pt-Au MNCs supported on graphitized mesoporous carbon show catalytic activity that is 24 times greater than that of a commercially available Pt catalyst for aerobic oxidation of hydrocarbons. In addition, solvent-free aerobic oxidation of hydrocarbons to ketones at room temperature, using small amounts of a radical initiator, was achieved as a heterogeneous catalytic reaction for the first time.
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Affiliation(s)
- Masaki Takahashi
- Interdisciplinary Graduate School of Medicine and Engineering, University of Yamanashi, 4-4-37 Takeda, Kofu 400-8510, Japan
- Laboratory for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology, Yokohama 226-8503, Japan
- Exploratory Research for Advanced Technology–Japan Science and Technology Agency (ERATO-JST), Kawaguchi, Saitama 332-0012, Japan
| | - Hiromu Koizumi
- Laboratory for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology, Yokohama 226-8503, Japan
| | - Wang-Jae Chun
- Exploratory Research for Advanced Technology–Japan Science and Technology Agency (ERATO-JST), Kawaguchi, Saitama 332-0012, Japan
- Graduate School of Arts and Sciences, International Christian University, Mitaka, Tokyo 181-8585, Japan
| | - Makoto Kori
- Laboratory for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology, Yokohama 226-8503, Japan
| | - Takane Imaoka
- Laboratory for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology, Yokohama 226-8503, Japan
- Exploratory Research for Advanced Technology–Japan Science and Technology Agency (ERATO-JST), Kawaguchi, Saitama 332-0012, Japan
- Precursory Research for Embryonic Science and Technology–Japan Science and Technology (PRESTO-JST), Kawaguchi, Saitama 332-0012, Japan
| | - Kimihisa Yamamoto
- Laboratory for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology, Yokohama 226-8503, Japan
- Exploratory Research for Advanced Technology–Japan Science and Technology Agency (ERATO-JST), Kawaguchi, Saitama 332-0012, Japan
- Corresponding author.
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42
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Ono T, Date I, Imaoka T, Shingo T, Furuta T, Asari S, Ohmoto T. Evaluation of Intracerebral Grafting of Dopamine-Secreting PC12 Cells into Allogeneic and Xenogeneic Brain. Cell Transplant 2017; 6:511-3. [PMID: 9331503 DOI: 10.1177/096368979700600512] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
The PC12 pheochromocytoma tumor cell line is derived from a rat adrenal medullary tumor and secretes dopamine. We have previously reported that grafted microencapsulated PC12 cells using agarose and poly(styrene sulfonic acid) survived in the xenogeneic brain without immunosuppression. To investigate whether unencapsulated PC12 cells form a tumor and how they provoke immunological reaction, PC12 cell suspension was implanted into the striatum of Sprague-Dawley rat (allogeneic graft) or guinea pig (xenogeneic graft) and histological analysis using Nissl stain and immunocytochemical analysis using antityrosine hydroxylase (TH) antibody were performed 1, 2, and 4 wk after transplantation. Host animals were not immunosuppressed. PC12 cells formed a mass 1 and 2 wk after transplantation both in allogeneic and xenogeneic brain. These grafted PC12 cells were immunoreactive to anti-TH antibody. Four weeks after transplantation, however, grafted PC12 cells in the allogeneic brain were only found within the restricted area near the site of implantation. In the xenogeneic brain, only the trace of grafted PC12 cells were found around the site of implantation 4 wk after transplantation. In both allogeneic and xenogeneic animals, a number of lymphocytes were found in and around the grafts at all period investigated. These findings indicate that PC12 cells could survive in the allogeneic or xenogeneic brain for 2 wk and were ultimately rejected by immunological reaction by 4 wk after transplantation. Implantation of encapsulated PC12 cells in the allogeneic or xenogeneic brain is considered a safe and effective method for delivering dopamine into the brain because PC12 cells will not form a tumor in the long-term even if capsules are damaged in some reason.
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Affiliation(s)
- T Ono
- Department of Neurological Surgery, Okayama University Medical School, Japan
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Kambe T, Imaoka T, Yamamoto K. Inside Back Cover: Reducing Capsule Based on Electron Programming: Versatile Synthesizer for Size-Controlled Ultra-Small Metal Clusters (Chem. Eur. J. 46/2016). Chemistry 2016. [DOI: 10.1002/chem.201604371] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Tetsuya Kambe
- Chemical Resources Laboratory; Tokyo Institute of Technology; 4259 Nagatsuta-cho Midori-ku Yokohama 226-8503 Japan
- Yamamoto Atom Hybrid Project, ERATO (Japan) Science and Technology Agency (JST); Tokyo Institute of Technology; 4259 Nagatsuta-cho Midori-ku Yokohama 226-8503 Japan
| | - Takane Imaoka
- Chemical Resources Laboratory; Tokyo Institute of Technology; 4259 Nagatsuta-cho Midori-ku Yokohama 226-8503 Japan
- Yamamoto Atom Hybrid Project, ERATO (Japan) Science and Technology Agency (JST); Tokyo Institute of Technology; 4259 Nagatsuta-cho Midori-ku Yokohama 226-8503 Japan
| | - Kimihisa Yamamoto
- Chemical Resources Laboratory; Tokyo Institute of Technology; 4259 Nagatsuta-cho Midori-ku Yokohama 226-8503 Japan
- Yamamoto Atom Hybrid Project, ERATO (Japan) Science and Technology Agency (JST); Tokyo Institute of Technology; 4259 Nagatsuta-cho Midori-ku Yokohama 226-8503 Japan
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Kambe T, Watanabe A, Imaoka T, Yamamoto K. Bismuth Complexes in Phenylazomethine Dendrimers: Controllable Luminescence and Emission in the Solid State. Angew Chem Int Ed Engl 2016. [DOI: 10.1002/ange.201607396] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Tetsuya Kambe
- Laboratory for Chemistry and Life Science; Tokyo Institute of Technology; 4259 Nagatsuta Midori-ku Yokohama 226-8503 Japan
- ERATO Japan Science and Technology (JST); 4259 Nagatsuta Midori-ku Yokohama 226-8503 Japan
| | - Aiko Watanabe
- Laboratory for Chemistry and Life Science; Tokyo Institute of Technology; 4259 Nagatsuta Midori-ku Yokohama 226-8503 Japan
| | - Takane Imaoka
- Laboratory for Chemistry and Life Science; Tokyo Institute of Technology; 4259 Nagatsuta Midori-ku Yokohama 226-8503 Japan
- ERATO Japan Science and Technology (JST); 4259 Nagatsuta Midori-ku Yokohama 226-8503 Japan
| | - Kimihisa Yamamoto
- Laboratory for Chemistry and Life Science; Tokyo Institute of Technology; 4259 Nagatsuta Midori-ku Yokohama 226-8503 Japan
- ERATO Japan Science and Technology (JST); 4259 Nagatsuta Midori-ku Yokohama 226-8503 Japan
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Kambe T, Watanabe A, Imaoka T, Yamamoto K. Bismuth Complexes in Phenylazomethine Dendrimers: Controllable Luminescence and Emission in the Solid State. Angew Chem Int Ed Engl 2016; 55:13151-13154. [PMID: 27709815 DOI: 10.1002/anie.201607396] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2016] [Indexed: 11/07/2022]
Abstract
Dendritic phosphors were obtained by the stepwise integration of BiCl3 in phenylazomethine dendrimers. The bismuth-coordinated phenylazomethines displayed photoluminescence at 500-800 nm, and the intensity could be tuned by changing the stoichiometry of BiCl3 and the dendrimer. This phosphor did not show serious luminescence quenching even though the local concentration of BiCl3 in the dendrimer was as high as 20 M, and luminescence was also observed in the solid state. The absorption and emission properties could be reversibly switched by addition of a Lewis base or under electrochemical redox control, which induced the reversible complexation of BiCl3 in the dendrimer.
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Affiliation(s)
- Tetsuya Kambe
- Laboratory for Chemistry and Life Science, Tokyo Institute of Technology, 4259 Nagatsuta Midori-ku, Yokohama, 226-8503, Japan.,ERATO Japan Science and Technology (JST), 4259 Nagatsuta Midori-ku, Yokohama, 226-8503, Japan
| | - Aiko Watanabe
- Laboratory for Chemistry and Life Science, Tokyo Institute of Technology, 4259 Nagatsuta Midori-ku, Yokohama, 226-8503, Japan
| | - Takane Imaoka
- Laboratory for Chemistry and Life Science, Tokyo Institute of Technology, 4259 Nagatsuta Midori-ku, Yokohama, 226-8503, Japan.,ERATO Japan Science and Technology (JST), 4259 Nagatsuta Midori-ku, Yokohama, 226-8503, Japan
| | - Kimihisa Yamamoto
- Laboratory for Chemistry and Life Science, Tokyo Institute of Technology, 4259 Nagatsuta Midori-ku, Yokohama, 226-8503, Japan. .,ERATO Japan Science and Technology (JST), 4259 Nagatsuta Midori-ku, Yokohama, 226-8503, Japan.
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Kambe T, Imaoka T, Yamamoto K. Reducing Capsule Based on Electron Programming: Versatile Synthesizer for Size-Controlled Ultra-Small Metal Clusters. Chemistry 2016; 22:16406-16409. [DOI: 10.1002/chem.201603229] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2016] [Indexed: 11/11/2022]
Affiliation(s)
- Tetsuya Kambe
- Chemical Resources Laboratory; Tokyo Institute of Technology; 4259 Nagatsuta-cho Midori-ku Yokohama 226-8503 Japan
- Yamamoto Atom Hybrid Project, ERATO (Japan) Science and Technology Agency (JST); Tokyo Institute of Technology; 4259 Nagatsuta-cho Midori-ku Yokohama 226-8503 Japan
| | - Takane Imaoka
- Chemical Resources Laboratory; Tokyo Institute of Technology; 4259 Nagatsuta-cho Midori-ku Yokohama 226-8503 Japan
- Yamamoto Atom Hybrid Project, ERATO (Japan) Science and Technology Agency (JST); Tokyo Institute of Technology; 4259 Nagatsuta-cho Midori-ku Yokohama 226-8503 Japan
| | - Kimihisa Yamamoto
- Chemical Resources Laboratory; Tokyo Institute of Technology; 4259 Nagatsuta-cho Midori-ku Yokohama 226-8503 Japan
- Yamamoto Atom Hybrid Project, ERATO (Japan) Science and Technology Agency (JST); Tokyo Institute of Technology; 4259 Nagatsuta-cho Midori-ku Yokohama 226-8503 Japan
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Odawara M, Miyagawa J, Iwamoto N, Takita Y, Imaoka T, Takamura T. Once-weekly glucagon-like peptide-1 receptor agonist dulaglutide significantly decreases glycated haemoglobin compared with once-daily liraglutide in Japanese patients with type 2 diabetes: 52 weeks of treatment in a randomized phase III study. Diabetes Obes Metab 2016; 18:249-57. [PMID: 26661514 PMCID: PMC5064615 DOI: 10.1111/dom.12602] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/27/2015] [Revised: 09/18/2015] [Accepted: 10/28/2015] [Indexed: 01/14/2023]
Abstract
AIMS To examine the efficacy and safety of once-weekly dulaglutide 0.75 mg monotherapy compared with once-daily liraglutide 0.9 mg in Japanese patients with type 2 diabetes (T2D) for 52 weeks. METHODS We conducted a phase III, randomized, 52-week (26-week primary endpoint), active- and placebo-controlled trial comparing 492 Japanese patients (dulaglutide, n = 281; liraglutide, n = 141; and placebo, n = 70). Participants and investigators were blinded to treatment assignment for dulaglutide and placebo but not for liraglutide (open-label comparator); after 26 weeks, patients randomized to placebo were switched to once-weekly dulaglutide 0.75 mg (open-label). The present paper reports results for patients treated with dulaglutide and patients treated with liraglutide for 52 weeks. RESULTS At week 52, dulaglutide decreased HbA1c significantly from baseline compared with liraglutide [least squares mean difference: -0.20; 95% confidence interval (CI) -0.39, -0.01; p = 0.04]. At week 52 (last observation carried forward), dulaglutide significantly decreased pre- and post-dinner blood glucose (BG) levels, the mean of seven-point self-monitored BG profiles, the mean of all postprandial BG levels and circadian variation compared with liraglutide. Body weight was generally stable in both groups through 52 weeks. The most frequently reported adverse events were nasopharyngitis, constipation, nausea and diarrhoea. Eight dulaglutide-treated (2.9%) and four liraglutide-treated (2.9%) patients reported hypoglycaemia, with no event being severe. CONCLUSIONS Monotherapy with once-weekly dulaglutide 0.75 mg was effective and safe in Japanese patients with T2D, with better glycaemic control compared with once-daily liraglutide 0.9 mg.
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Affiliation(s)
- M Odawara
- Division of Diabetes, Endocrinology and Metabolism, Department of Diabetes, Endocrinology, Metabolism and Rheumatology, Tokyo Medical University, Tokyo, Japan
| | - J Miyagawa
- Division of Diabetes, Endocrinology and Metabolism, Department of Internal Medicine, Hyogo College of Medicine, Nishinomiya, Japan
| | | | - Y Takita
- Eli Lilly Japan K.K., Kobe, Japan
| | - T Imaoka
- Eli Lilly Japan K.K., Kobe, Japan
| | - T Takamura
- Department of Comprehensive Metabology, Kanazawa University Graduate School of Medical Sciences, Kanazawa, Japan
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Miyagawa J, Odawara M, Takamura T, Iwamoto N, Takita Y, Imaoka T. Once-weekly glucagon-like peptide-1 receptor agonist dulaglutide is non-inferior to once-daily liraglutide and superior to placebo in Japanese patients with type 2 diabetes: a 26-week randomized phase III study. Diabetes Obes Metab 2015; 17:974-83. [PMID: 26179187 PMCID: PMC5042083 DOI: 10.1111/dom.12534] [Citation(s) in RCA: 74] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/06/2015] [Revised: 06/22/2015] [Accepted: 07/02/2015] [Indexed: 01/13/2023]
Abstract
AIMS To examine the efficacy and safety of once-weekly dulaglutide monotherapy (0.75 mg) compared with placebo and once-daily liraglutide (0.9 mg) in Japanese patients with type 2 diabetes. METHODS This was a phase III, 52-week (26-week primary endpoint), randomized, double-blind, placebo-controlled, open-label comparator (liraglutide) trial comparing 492 Japanese patients with type 2 diabetes (dulaglutide, n = 281; liraglutide, n = 141; and placebo, n = 70) who were aged ≥20 years. Patients and investigators were blinded to treatment assignment for dulaglutide and placebo but not for liraglutide. The primary objective evaluated the superiority of dulaglutide versus placebo on change from baseline in glycated haemoglobin (HbA1c) at 26 weeks. Analyses were performed on the full analysis set. RESULTS At 26 weeks, once-weekly dulaglutide was superior to placebo and non-inferior to once-daily liraglutide for HbA1c change from baseline [least squares mean difference: dulaglutide vs placebo -1.57% (95% confidence interval -1.79 to -1.35); dulaglutide vs liraglutide -0.10% (95% confidence interval -0.27 to 0.07)]. The most frequently reported adverse events were nasopharyngitis, constipation, diarrhoea, nausea, abdominal distension and decreased appetite; only decreased appetite was different between the dulaglutide and liraglutide groups [dulaglutide, n = 2 (0.7%); liraglutide, n = 8 (5.8%); p = 0.003]. Nine (1.8%) patients experienced hypoglycaemia [dulaglutide, n = 6 (2.1%); liraglutide, n = 2 (1.5%); placebo, n = 1 (1.4%)], with no event being severe. CONCLUSIONS In Japanese patients with type 2 diabetes, once-weekly dulaglutide (0.75 mg) was superior to placebo and non-inferior to once-daily liraglutide (0.9 mg) for reduction in HbA1c at 26 weeks. Dulaglutide was safe and well tolerated.
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Affiliation(s)
- J Miyagawa
- Division of Diabetes, Endocrinology and Metabolism, Department of Internal Medicine, Hyogo College of Medicine, Nishinomiya, Japan
| | - M Odawara
- Division of Diabetes, Endocrinology and Metabolism, Department of Diabetes, Endocrinology, Metabolism and Rheumatology, Tokyo Medical University, Tokyo, Japan
| | - T Takamura
- Department of Comprehensive Metabology, Kanazawa University Graduate School of Medical Sciences, Kanazawa, Japan
| | | | - Y Takita
- Eli Lilly Japan K.K, Kobe, Japan
| | - T Imaoka
- Eli Lilly Japan K.K, Kobe, Japan
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Araki E, Inagaki N, Tanizawa Y, Oura T, Takeuchi M, Imaoka T. Efficacy and safety of once-weekly dulaglutide in combination with sulphonylurea and/or biguanide compared with once-daily insulin glargine in Japanese patients with type 2 diabetes: a randomized, open-label, phase III, non-inferiority study. Diabetes Obes Metab 2015; 17:994-1002. [PMID: 26179754 PMCID: PMC5042081 DOI: 10.1111/dom.12540] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/14/2015] [Revised: 06/23/2015] [Accepted: 07/02/2015] [Indexed: 01/18/2023]
Abstract
AIMS To evaluate 0.75 mg of dulaglutide, a once-weekly glucagon-like peptide-1 receptor agonist, compared with once-daily insulin glargine for glycaemic control in Japanese patients with type 2 diabetes (T2D). METHODS In this phase III, randomized, open-label, parallel-group, 26-week study, 361 patients with inadequately controlled T2D receiving sulphonylureas and/or biguanides, aged ≥20 years, with glycated haemoglobin (HbA1c) levels 7.0-10.0% (53-86 mmol/mol), inclusive, were randomized (1 : 1) to receive dulaglutide or glargine. Participants and investigators were not masked to treatment allocation. The primary measure was change from baseline in HbA1c at 26 weeks, analysed using a mixed-effects model for repeated measures, with a predefined non-inferiority margin of 0.4%. RESULTS At week 26, least-squares (LS) mean (standard error) reductions in HbA1c were -1.44 (0.05)% [-15.74 (0.55) mmol/mol] in the dulaglutide group and -0.90 (0.05)% [-9.84 (0.55) mmol/mol] in the glargine group. The mean between-group treatment difference in HbA1c was -0.54% (95% CI -0.67, -0.41) [-5.90 mmol/mol (95% CI -7.32, -4.48)]; p < 0.001. Dulaglutide significantly reduced body weight compared with glargine at week 26 (LS mean difference -1.42 kg, 95% CI -1.89, -0.94; p < 0.001). The most frequent adverse events with dulaglutide treatment were nasopharyngitis and gastrointestinal symptoms. The incidence of hypoglycaemia was significantly lower with dulaglutide [47/181 (26%)] compared with glargine [86/180 (48%)], p < 0.001. CONCLUSION In Japanese patients with T2D uncontrolled on sulphonylureas and/or biguanides, once-weekly dulaglutide was superior to once-daily glargine for reduction in HbA1c at 26 weeks. Although dulaglutide increased gastrointestinal symptoms, it was well tolerated, with an acceptable safety profile.
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Affiliation(s)
- E Araki
- Department of Metabolic Medicine, Faculty of Life Sciences, Kumamoto University, Kumamoto, Japan
| | - N Inagaki
- Department of Diabetes, Endocrinology and Nutrition, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Y Tanizawa
- Division of Endocrinology, Metabolism, Hematological Science and Therapeutics, Yamaguchi University Graduate School of Medicine, Yamaguchi, Japan
| | - T Oura
- Eli Lilly Japan K.K., Kobe, Japan
| | | | - T Imaoka
- Eli Lilly Japan K.K., Kobe, Japan
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