Researcher basic information

• 博士（理学）, 北海道大学

• https://researchmap.jp/sakamotonaoya?lang=en

• https://jglobal.jst.go.jp/detail?JGLOBAL_ID=201501037394708760
• https://www.cris.hokudai.ac.jp/naoya/

• 201501037394708760

• SIMS
• 隕石
• 同位体
• 質量分析
• イメージセンサ
• 同位体イメージング
• 二次イオン質量分析計
• 宇宙化学

• Natural Science, Solid earth sciences
• Life Science, Molecular biology
• Natural Science, Space and planetary sciences

• Bachelor's degree program, Departments of Medicine, School of Medicine
• Master's degree program, Graduate School of Medicine
• Doctoral (PhD) degree program, Graduate School of Medicine

Research activity information

• Elasticity of β-Mg₂SiO₄ containing 1.2 wt% H₂O to 10 GPa and 600 K by ultrasonic interferometry with synchrotron X-radiation
  Masamichi Noda; Gabriel D. Gwanmesia; Matthew L. Whitaker; Haiyan Chen; Toru Inoue; Naoya Sakamoto; Hisayoshi Yurimoto
  AMERICAN MINERALOGIST, 111, 1, 128, 137, 27 Jan. 2026
  English, Scientific journal
• Origin of Earth’s hydrogen and carbon constrained by their core-mantle partitioning and bulk Earth abundance
  Yutaro Tsutsumi; Naoya Sakamoto; Kei Hirose; Shuhei Mita; Shunpei Yokoo; Han Hsu; Hisayoshi Yurimoto
  Nature Communications, 16, 1, Springer Science and Business Media LLC, 21 Nov. 2025
  Scientific journal
• Mineralogical evidence for hydrothermal alteration of Bennu samples
  T. J. Zega; T. J. McCoy; S. S. Russell; L. P. Keller; Z. Gainsforth; S. A. Singerling; V. R. Manga; C. Harrison; G. Libourel; B. S. Prince; K. Thomas-Keprta; A. King; M. Portail; V. Guigoz; V. Tu; L. Le; M. Thompson; M. C. Benner; N. A. Kerrison; J. J. Barnes; I. Ong; P. Haenecour; L. Chaves; L. Smith; M. Kontogiannis; N. Vega Santiago; D. Hill; Z. Zeszut; K. Domanik; Y.-J. Chang; C. M. Corrigan; S. Ray; L. R. Wardell; T. Gooding; T. R. Rose; H. C. Bates; P. F. Schofield; N. V. Almeida; T. Salge; J. Najorka; L. B. Seifert; N. Lunning; K. Righter; A. N. Nguyen; F. E. Brenker; S. A. Eckley; J. P. Dworkin; R. H. Jones; S. A. Sandford; M. A. Marcus; H. A. Bechtel; G. Dominguez; H. Yurimoto; N. Kawasaki; K. Bajo; N. Sakamoto; P.-M. Zanetta; S. Tachibana; H. Busemann; V. E. Hamilton; I. A. Franchi; M. Grady; R. C. Greenwood; K. Tait; N. Timms; P. Bland; F. Jourdan; S. M. Reddy; W. Rickard; D. Saxey; L. Vincze; H. C. Connolly; D. S. Lauretta
  Nature Geoscience, 18, 9, 832, 839, Springer Science and Business Media LLC, 22 Aug. 2025
  Scientific journal
• The variety and origin of materials accreted by Bennu’s parent asteroid
  J. J. Barnes; A. N. Nguyen; F. A. J. Abernethy; K. Bajo; D. V. Bekaert; E. Bloch; G. A. Brennecka; H. Busemann; J. S. Cowpe; S. A. Crowther; M. Ek; L. J. Fawcett; M. A. Fehr; I. A. Franchi; E. Füri; J. D. Gilmour; M. M. Grady; R. C. Greenwood; P. Haenecour; N. Kawasaki; P. Koefoed; D. Krietsch; L. Le; K. M. Liszewska; C. Maden; J. Malley; Y. Marrocchi; B. Marty; L. A. E. Meyer; T. S. Peretyazhko; L. Piani; J. Render; S. S. Russell; M. Rüfenacht; N. Sakamoto; M. Schönbächler; Q. R. Shollenberger; L. Smith; K. Thomas-Keprta; A. B. Verchovsky; J. Villeneuve; K. Wang; K. C. Welten; J. Wimpenny; E. A. Worsham; H. Yurimoto; L. Zimmermann; X. Zhao; C. M. O’D. Alexander; M. Amini; A. Baczynski; P. Bland; L. E. Borg; R. Burgess; M. W. Caffee; L. C. Chaves; P. L. Clay; J. P. Dworkin; D. I. Foustoukos; D. P. Glavin; V. E. Hamilton; D. Hill; C. H. House; G. R. Huss; T. Ireland; C. E. Jilly; F. Jourdan; L. P. Keller; T. S. Kruijer; V. Lai; T. J. McCoy; K. Nagashima; K. Nishiizumi; R. Ogliore; I. J. Ong; S. M. Reddy; W. D. A. Rickard; S. Sandford; D. W. Saxey; N. Timms; D. Weis; Z. E. Wilbur; T. J. Zega; D. N. DellaGiustina; C. W. V. Wolner; H. C. Connolly; D. S. Lauretta
  Nature Astronomy, Springer Science and Business Media LLC, 22 Aug. 2025
  Scientific journal, Abstract
  
  The first bodies to form in the Solar System acquired their materials from stars, the presolar molecular cloud and the protoplanetary disk. Asteroids that have not undergone planetary differentiation retain evidence of these primary accreted materials. However, geologic processes such as hydrothermal alteration can dramatically change their bulk mineralogy, isotopic compositions and chemistry. Here we analyse the elemental and isotopic compositions of samples from asteroid Bennu to uncover the sources and types of material accreted by its parent body. We show that some primary accreted materials escaped the extensive aqueous alteration that occurred on the parent asteroid, including presolar grains from ancient stars, organic matter from the outer Solar System or molecular cloud, refractory solids that formed close to the Sun, and dust enriched in neutron-rich Ti isotopes. We find Bennu to be richer in isotopically anomalous organic matter, anhydrous silicates, and light isotopes of K and Zn than its closest compositional counterparts, asteroid Ryugu and Ivuna-type (CI) carbonaceous chondrite meteorites. We propose that the parent bodies of Bennu, Ryugu and CI chondrites formed from a common but spatially and/or temporally heterogeneous reservoir of materials in the outer protoplanetary disk.
• Solar System’s earliest solids as tracers of the accretion region of Ryugu and Ivuna-type carbonaceous chondrites
  Noriyuki Kawasaki; Sota Arakawa; Yushi Miyamoto; Naoya Sakamoto; Daiki Yamamoto; Sara S. Russell; Hisayoshi Yurimoto
  Communications Earth & Environment, 6, 1, Springer Science and Business Media LLC, 16 Jul. 2025
  Scientific journal
• An evaporite sequence from ancient brine recorded in Bennu samples
  T. J. McCoy; S. S. Russell; T. J. Zega; K. L. Thomas-Keprta; S. A. Singerling; F. E. Brenker; N. E. Timms; W. D. A. Rickard; J. J. Barnes; G. Libourel; S. Ray; C. M. Corrigan; P. Haenecour; Z. Gainsforth; G. Dominguez; A. J. King; L. P. Keller; M. S. Thompson; S. A. Sandford; R. H. Jones; H. Yurimoto; K. Righter; S. A. Eckley; P. A. Bland; M. A. Marcus; D. N. DellaGiustina; T. R. Ireland; N. V. Almeida; C. S. Harrison; H. C. Bates; P. F. Schofield; L. B. Seifert; N. Sakamoto; N. Kawasaki; F. Jourdan; S. M. Reddy; D. W. Saxey; I. J. Ong; B. S. Prince; K. Ishimaru; L. R. Smith; M. C. Benner; N. A. Kerrison; M. Portail; V. Guigoz; P.-M. Zanetta; L. R. Wardell; T. Gooding; T. R. Rose; T. Salge; L. Le; V. M. Tu; Z. Zeszut; C. Mayers; X. Sun; D. H. Hill; N. G. Lunning; V. E. Hamilton; D. P. Glavin; J. P. Dworkin; H. H. Kaplan; I. A. Franchi; K. T. Tait; S. Tachibana; H. C. Connolly; D. S. Lauretta
  Nature, 637, 8048, 1072, 1077, Springer Science and Business Media LLC, 29 Jan. 2025
  Scientific journal, Abstract
  
  Evaporation or freezing of water-rich fluids with dilute concentrations of dissolved salts can produce brines, as observed in closed basins on Earth¹ and detected by remote sensing on icy bodies in the outer Solar System^2,3. The mineralogical evolution of these brines is well understood in regard to terrestrial environments⁴, but poorly constrained for extraterrestrial systems owing to a lack of direct sampling. Here we report the occurrence of salt minerals in samples of the asteroid (101955) Bennu returned by the OSIRIS-REx mission⁵. These include sodium-bearing phosphates and sodium-rich carbonates, sulfates, chlorides and fluorides formed during evaporation of a late-stage brine that existed early in the history of Bennu’s parent body. Discovery of diverse salts would not be possible without mission sample return and careful curation and storage, because these decompose with prolonged exposure to Earth’s atmosphere. Similar brines probably still occur in the interior of icy bodies Ceres and Enceladus, as indicated by spectra or measurement of sodium carbonate on the surface or in plumes^2,3.
• Zirconium isotope composition indicates s‐process depletion in samples returned from asteroid Ryugu
  Maria Schönbächler; Manuela A. Fehr; Tetsuya Yokoyama; Ikshu Gautam; Nao Nakanishi; Yoshinari Abe; Jérôme Aléon; Conel Alexander; Sachiko Amari; Yuri Amelin; Ken‐ichi Bajo; Martin Bizzarro; Audrey Bouvier; Richard W. Carlson; Marc Chaussidon; Byeon‐Gak Choi; Nicolas Dauphas; Andrew M. Davis; Tommaso Di Rocco; Wataru Fujiya; Ryota Fukai; Makiko K. Haba; Yuki Hibiya; Hiroshi Hidaka; Hisashi Homma; Peter Hoppe; Gary R. Huss; Kiyohiro Ichida; Tsuyoshi Iizuka; Trevor Ireland; Akira Ishikawa; Shoichi Itoh; Noriyuki Kawasaki; Noriko T. Kita; Koki Kitajima; Thorsten Kleine; Shintaro Komatani; Alexander N. Krot; Ming‐Chang Liu; Yuki Masuda; Mayu Morita; Kazuko Motomura; Frédéric Moynier; Izumi Nakai; Kazuhide Nagashima; Ann Nguyen; Larry Nittler; Morihiko Onose; Andreas Pack; Changkun Park; Laurette Piani; Liping Qin; Sara Russell; Naoya Sakamoto; Lauren Tafla; Haolan Tang; Kentaro Terada; Yasuko Terada; Tomohiro Usui; Sohei Wada; Meenakshi Wadhwa; Richard J. Walker; Katsuyuki Yamashita; Qing‐Zhu Yin; Shigekazu Yoneda; Edward D. Young; Hiroharu Yui; Ai‐Cheng Zhang; Tomoki Nakamura; Hiroshi Naraoka; Takaaki Noguchi; Ryuji Okazaki; Kanako Sakamoto; Hikaru Yabuta; Masanao Abe; Akiko Miyazaki; Aiko Nakato; Masahiro Nishimura; Tatsuaki Okada; Toru Yada; Kasumi Yogata; Satoru Nakazawa; Takanao Saiki; Satoshi Tanaka; Fuyuto Terui; Yuichi Tsuda; Sei‐ichiro Watanabe; Makoto Yoshikawa; Shogo Tachibana; Hisayoshi Yurimoto
  Meteoritics & Planetary Science, Wiley, 25 Nov. 2024
  Scientific journal, Abstract
  
  Nucleosynthetic isotope variations are powerful tracers to determine genetic relationships between meteorites and planetary bodies. They can help to link material collected by space missions to known meteorite groups. The Hayabusa 2 mission returned samples from the Cb‐type asteroid (162173) Ryugu. The mineralogical, chemical, and isotopic characteristics of these samples show strong similarities to carbonaceous chondrites and in particular CI chondrites. The nucleosynthetic isotope compositions of Ryugu overlap with CI chondrites for several elements (e.g., Cr, Ti, Fe, and Zn). In contrast to these isotopes, which are of predominately supernovae origin, s‐process variations in Mo isotope data are similar to those of carbonaceous chondrites, but even more s‐process depleted. To further constrain the origin of this depletion and test whether this signature is also present for other s‐process elements, we report Zr isotope compositions for three bulk Ryugu samples (A0106, A0106‐A0107, C0108) collected from the Hayabusa 2 mission. The data are complemented with that of terrestrial rock reference materials, eucrites, and carbonaceous chondrites. The Ryugu samples are characterized by distinct ⁹⁶Zr enrichment relative to Earth, indicative of a s‐process depletion. Such depletion is also observed for carbonaceous chondrites and eucrites, in line with previous Zr isotope work, but it is more extreme in Ryugu, as observed for Mo isotopes. Since s‐process Zr and Mo are coupled in mainstream SiC grains, these distinct s‐process variations might be due to SiC grain depletion in the analyzed materials, potentially caused by incomplete sample digestion, because the Ryugu samples were dissolved on a hotplate only to avoid high blank levels for other elements (e.g., Cr). However, local depletion of SiC grains cannot be excluded. An alternative, equally possible scenario is that aqueous alteration redistributed anomalous, s‐process‐depleted, Zr on a local scale, for example, into Ca‐phosphates or phyllosilicates.
• Update on the 53Mn-53Cr ages of dolomite in the Ivuna CI chondrite and asteroid Ryugu sample
  Shingo Sugawara; Wataru Fujiya; Noriyuki Kawasaki; Naoya Sakamoto; Akira Yamaguchi; Hisayoshi Yurimoto
  Geochimica et Cosmochimica Acta, 382, 40, 50, Elsevier BV, Oct. 2024, [Peer-reviewed]
  Scientific journal
• The Ni isotopic composition of Ryugu reveals a common accretion region for carbonaceous chondrites
  Fridolin Spitzer; Thorsten Kleine; Christoph Burkhardt; Timo Hopp; Tetsuya Yokoyama; Yoshinari Abe; Jérôme Aléon; Conel M. O’D Alexander; Sachiko Amari; Yuri Amelin; Ken-ichi Bajo; Martin Bizzarro; Audrey Bouvier; Richard W. Carlson; Marc Chaussidon; Byeon-Gak Choi; Nicolas Dauphas; Andrew M. Davis; Tommaso Di Rocco; Wataru Fujiya; Ryota Fukai; Ikshu Gautam; Makiko K. Haba; Yuki Hibiya; Hiroshi Hidaka; Hisashi Homma; Peter Hoppe; Gary R. Huss; Kiyohiro Ichida; Tsuyoshi Iizuka; Trevor R. Ireland; Akira Ishikawa; Shoichi Itoh; Noriyuki Kawasaki; Noriko T. Kita; Kouki Kitajima; Shintaro Komatani; Alexander N. Krot; Ming-Chang Liu; Yuki Masuda; Mayu Morita; Fréderic Moynier; Kazuko Motomura; Izumi Nakai; Kazuhide Nagashima; Ann Nguyen; Larry Nittler; Morihiko Onose; Andreas Pack; Changkun Park; Laurette Piani; Liping Qin; Sara S. Russell; Naoya Sakamoto; Maria Schönbächler; Lauren Tafla; Haolan Tang; Kentaro Terada; Yasuko Terada; Tomohiro Usui; Sohei Wada; Meenakshi Wadhwa; Richard J. Walker; Katsuyuki Yamashita; Qing-Zhu Yin; Shigekazu Yoneda; Edward D. Young; Hiroharu Yui; Ai-Cheng Zhang; Tomoki Nakamura; Hiroshi Naraoka; Takaaki Noguchi; Ryuji Okazaki; Kanako Sakamoto; Hikaru Yabuta; Masanao Abe; Akiko Miyazaki; Aiko Nakato; Masahiro Nishimura; Tatsuaki Okada; Toru Yada; Kasumi Yogata; Satoru Nakazawa; Takanao Saiki; Satoshi Tanaka; Fuyuto Terui; Yuichi Tsuda; Sei-ichiro Watanabe; Makoto Yoshikawa; Shogo Tachibana; Hisayoshi Yurimoto
  Science Advances, 10, 39, American Association for the Advancement of Science (AAAS), 27 Sep. 2024
  Scientific journal, The isotopic compositions of samples returned from Cb-type asteroid Ryugu and Ivuna-type (CI) chondrites are distinct from other carbonaceous chondrites, which has led to the suggestion that Ryugu/CI chondrites formed in a different region of the accretion disk, possibly around the orbits of Uranus and Neptune. We show that, like for Fe, Ryugu and CI chondrites also have indistinguishable Ni isotope anomalies, which differ from those of other carbonaceous chondrites. We propose that this unique Fe and Ni isotopic composition reflects different accretion efficiencies of small FeNi metal grains among the carbonaceous chondrite parent bodies. The CI chondrites incorporated these grains more efficiently, possibly because they formed at the end of the disk’s lifetime, when planetesimal formation was also triggered by photoevaporation of the disk. Isotopic variations among carbonaceous chondrites may thus reflect fractionation of distinct dust components from a common reservoir, implying CI chondrites/Ryugu may have formed in the same region of the accretion disk as other carbonaceous chondrites.
• Trace element partitioning in a deep magma ocean and the origin of the Hf-Nd mantle array
  Keisuke Ozawa; Naoya Sakamoto; Yutaro Tsutsumi; Kei Hirose; Tsuyoshi Iizuka; Hisayoshi Yurimoto
  Science Advances, 10, 33, American Association for the Advancement of Science (AAAS), 16 Aug. 2024, [Peer-reviewed]
  Scientific journal, Crystallization in Earth’s deep magma ocean could have caused trace element fractionation in the lower mantle that might be inherited to the isotopic compositions of the present-day mantle. However, the trace element partitioning has been experimentally investigated only up to the uppermost lower-mantle pressures. Here, we determined the bridgmanite/melt partition coefficients D of La, Nd, Sm, Lu, and Hf from 24 to 115 gigapascals, covering the wide pressure range of the lower mantle. Results demonstrate substantial reductions in D _Lu and D _Hf from >1 to ≪1 with increasing pressure to 91 gigapascals. We also found D _Lu / D _Hf > 1 and D _Sm / D _Nd < 1 under deep lower-mantle conditions, evolving melts toward low Lu/Hf and high Sm/Nd ratios by crystallizing bridgmanite. If residual melts form a dense hidden reservoir in the lowermost mantle, the complementary accessible mantle has the Hf and Nd isotopic compositions matching the observed terrestrial mantle array that deviates from the bulk silicate Earth reference.
• Pyrrhotites in asteroid 162173 Ryugu: Records of the initial changes on their surfaces with aqueous alteration
  Hiroharu Yui; Shu hei Urashima; Morihiko Onose; Mayu Morita; Shintaro Komatani; Izumi Nakai; Yoshinari Abe; Yasuko Terada; Hisashi Homma; Kazuko Motomura; Kiyohiro Ichida; Tetsuya Yokoyama; Kazuhide Nagashima; Jérôme Aléon; Conel M. O'D. Alexander; Sachiko Amari; Yuri Amelin; Ken ichi Bajo; Martin Bizzarro; Audrey Bouvier; Richard W. Carlson; Marc Chaussidon; Byeon Gak Choi; Nicolas Dauphas; Andrew M. Davis; Wataru Fujiya; Ryota Fukai; Ikshu Gautam; Makiko K. Haba; Yuki Hibiya; Hiroshi Hidaka; Peter Hoppe; Gary R. Huss; Tsuyoshi Iizuka; Trevor R. Ireland; Akira Ishikawa; Shoichi Itoh; Noriyuki Kawasaki; Noriko T. Kita; Kouki Kitajima; Thorsten Kleine; Sasha Krot; Ming Chang Liu; Yuki Masuda; Frédéric Moynier; Ann Nguyen; Larry Nittler; Andreas Pack; Changkun Park; Laurette Piani; Liping Qin; Tommaso Di Rocco; Sara S. Russell; Naoya Sakamoto; Maria Schönbächler; Lauren Tafla; Haolan Tang; Kentaro Terada; Tomohiro Usui; Sohei Wada; Meenakshi Wadhwa; Richard J. Walker; Katsuyuki Yamashita; Qing Zhu Yin; Shigekazu Yoneda; Edward D. Young; Ai Cheng Zhang; Tomoki Nakamura; Hiroshi Naraoka; Takaaki Noguchi; Ryuji Okazaki; Kanako Sakamoto; Hikaru Yabuta; Masanao Abe; Akiko Miyazaki; Aiko Nakato; Masahiro Nishimura; Tatsuaki Okada; Toru Yada; Kasumi Yogata; Satoru Nakazawa; Takanao Saiki; Satoshi Tanaka; Fuyuto Terui; Yuichi Tsuda; Sei ichiro Watanabe; Makoto Yoshikawa; Shogo Tachibana; Hisayoshi Yurimoto
  Geochimica et Cosmochimica Acta, 379, 172, 183, 15 Aug. 2024
  Scientific journal
• Retention of water in subducted slabs under core–mantle boundary conditions
  Yutaro Tsutsumi; Naoya Sakamoto; Kei Hirose; Shoh Tagawa; Koichiro Umemoto; Yasuo Ohishi; Hisayoshi Yurimoto
  Nature Geoscience, Springer Science and Business Media LLC, 21 Jun. 2024, [Peer-reviewed]
  Scientific journal
• Disequilibrium oxygen isotope distribution among aqueously altered minerals in Ryugu asteroid returned samples
  Noriko T. Kita; Kouki Kitajima; Kazuhide Nagashima; Noriyuki Kawasaki; Naoya Sakamoto; Wataru Fujiya; Yoshinari Abe; Jérôme Aléon; Conel M. O'D. Alexander; Sachiko Amari; Yuri Amelin; Ken‐ichi Bajo; Martin Bizzarro; Audrey Bouvier; Richard W. Carlson; Marc Chaussidon; Byeon‐Gak Choi; Nicolas Dauphas; Andrew M. Davis; Tommaso Di Rocco; Ryota Fukai; Ikshu Gautam; Makiko K. Haba; Yuki Hibiya; Hiroshi Hidaka; Hisashi Homma; Peter Hoppe; Gary R. Huss; Kiyohiro Ichida; Tsuyoshi Iizuka; Trevor R. Ireland; Akira Ishikawa; Shoichi Itoh; Thorsten Kleine; Shintaro Komatani; Alexander N. Krot; Ming‐Chang Liu; Yuki Masuda; Kevin D. McKeegan; Mayu Morita; Kazuko Motomura; Frédéric Moynier; Izumi Nakai; Ann Nguyen; Larry Nittler; Morihiko Onose; Andreas Pack; Changkun Park; Laurette Piani; Liping Qin; Sara S. Russell; Maria Schönbächler; Lauren Tafla; Haolan Tang; Kentaro Terada; Yasuko Terada; Tomohiro Usui; Sohei Wada; Meenakshi Wadhwa; Richard J. Walker; Katsuyuki Yamashita; Qing‐Zhu Yin; Tetsuya Yokoyama; Shigekazu Yoneda; Edward D. Young; Hiroharu Yui; Ai‐Cheng Zhang; Tomoki Nakamura; Hiroshi Naraoka; Takaaki Noguchi; Ryuji Okazaki; Kanako Sakamoto; Hikaru Yabuta; Masanao Abe; Akiko Miyazaki; Aiko Nakato; Masahiro Nishimura; Tatsuaki Okada; Toru Yada; Kasumi Yogata; Satoru Nakazawa; Takanao Saiki; Satoshi Tanaka; Fuyuto Terui; Yuichi Tsuda; Sei‐ichiro Watanabe; Makoto Yoshikawa; Shogo Tachibana; Hisayoshi Yurimoto
  METEORITICS & PLANETARY SCIENCE, Wiley, Apr. 2024, [Peer-reviewed]
  Scientific journal, Abstract
  
  Oxygen 3‐isotope ratios of magnetite and carbonates in aqueously altered carbonaceous chondrites provide important clues to understanding the evolution of the fluid in the asteroidal parent bodies. We conducted oxygen 3‐isotope analyses of magnetite, dolomite, and breunnerite in two sections of asteroid Ryugu returned samples, A0058 and C0002, using a secondary ion mass spectrometer (SIMS). Magnetite was analyzed by using a lower primary ion energy that reduced instrumental biases due to the crystal orientation effect. We found two groups of magnetite data identified from the SIMS pit morphologies: (1) higher δ¹⁸O (from 3‰ to 7‰) and ∆¹⁷O (~2‰) with porous SIMS pits mostly from spherulitic magnetite, and (2) lower δ¹⁸O (~ −3‰) and variable ∆¹⁷O (0‰–2‰) mostly from euhedral magnetite. Dolomite and breunnerite analyses were conducted using multi‐collection Faraday cup detectors with precisions ≤0.3‰. The instrumental bias correction was applied based on carbonate compositions in two ways, using Fe and (Fe + Mn) contents, respectively, because Ryugu dolomite contains higher amounts of Mn than the terrestrial standard. Results of dolomite and breunnerite analyses show a narrow range of ∆¹⁷O; 0.0‰–0.3‰ for dolomite in A0058 and 0.2‰–0.8‰ for dolomite and breunnerite in C0002. The majority of breunnerite, including large ≥100 μm grains, show systematically lower δ¹⁸O (~21‰) than dolomite (25‰–30‰ and 23‰–27‰ depending on the instrumental bias corrections). The equilibrium temperatures between magnetite and dolomite from the coarse‐grained lithology in A0058 are calculated to be 51 ± 11°C and 78 ± 14°C, depending on the instrumental bias correction scheme for dolomite; a reliable temperature estimate would require a Mn‐bearing dolomite standard to evaluate the instrumental bias corrections, which is not currently available. These results indicate that the oxygen isotope ratios of aqueous fluids in the Ryugu parent asteroid were isotopically heterogeneous, either spatially, or temporary. Initial water ice accreted to the Ryugu parent body might have ∆¹⁷O > 2‰ that was melted and interacted with anhydrous solids with the initial ∆¹⁷O < 0‰. In the early stage of aqueous alteration, spherulitic magnetite and calcite formed from aqueous fluid with ∆¹⁷O ~ 2‰ that was produced by isotope exchange between water (∆¹⁷O > 2‰) and anhydrous solids (∆¹⁷O < 0‰). Dolomite and breunnerite, along with some magnetite, formed at the later stage of aqueous alteration under higher water‐to‐rock ratios where the oxygen isotope ratios were nearly at equilibrium between fluid and solid phases. Including literature data, δ¹⁸O of carbonates decreased in the order calcite, dolomite, and breunnerite, suggesting that the temperature of alteration might have increased with the degree of aqueous alteration.
• Olivine-Hosted Melt Inclusions Track Progressive Dehydration Reactions in Subducting Slabs Across Volcanic Arcs
  Raimundo Brahm; Daniel Coulthard Jr; Georg Zellmer; Takeshi Kuritani; Naoya Sakamoto; Hajime Taniuchi; Hisayoshi Yurimoto; Mitsuhiro Nakagawa; Eiichi Sato
  Journal of Petrology, Oxford University Press (OUP), 29 Feb. 2024, [Peer-reviewed]
  Scientific journal, Abstract
  
  The stability and breakdown of mineral phases in subducting slabs control the cycling of trace elements through subduction zones. Stability of key minerals and the partitioning of trace elements between these minerals and liquid phases of interests have been charted by natural sample analysis and experimental constraints. However, systematic study from arc front to far back-arc has rarely shown that the expected geochemical variations of the slab liquid are actually recorded by natural samples. Complexities arise by uncertainties on the nature of the slab component (melts, fluids and supercritical liquids), source heterogeneities and transport processes. Using data from olivine-hosted melt inclusions sampled along and across the NE Japan and southern Kurile arcs, we demonstrate that experimentally and thermodynamically constrained phase stabilities in subducted materials indeed control the trace element signatures as predicted by these models and experiments. The main reactions that can be traced across arc are progressive breakdown of light rare earth element-rich accessory phases (e.g., allanite), enhanced dehydration of the lithospheric mantle (serpentine breakdown) and changes in the nature of the slab component. This work elucidates subduction zone elemental cycling in a well-characterized petrogenetic setting and provides important constraints on the interpretation of trace element ratios in arc magmas in terms of the prograde metamorphic reactions within the subducting slab.
• Pervasive aqueous alteration in the early Solar System revealed by potassium isotopic variations in Ryugu samples and carbonaceous chondrites
  Yan Hu; Frédéric Moynier; Wei Dai; Marine Paquet; Tetsuya Yokoyama; Yoshinari Abe; Jérôme Aléon; Conel M.O.D. Alexander; Sachiko Amari; Yuri Amelin; Ken ichi Bajo; Martin Bizzarro; Audrey Bouvier; Richard W. Carlson; Marc Chaussidon; Byeon Gak Choi; Nicolas Dauphas; Andrew M. Davis; Tommaso Di Rocco; Wataru Fujiya; Ryota Fukai; Ikshu Gautam; Makiko K. Haba; Yuki Hibiya; Hiroshi Hidaka; Hisashi Homma; Peter Hoppe; Gary R. Huss; Kiyohiro Ichida; Tsuyoshi Iizuka; Trevor R. Ireland; Akira Ishikawa; Shoichi Itoh; Noriyuki Kawasaki; Noriko T. Kita; Koki Kitajima; Thorsten Kleine; Shintaro Komatani; Alexander N. Krot; Ming Chang Liu; Yuki Masuda; Mayu Morita; Kazuko Motomura; Izumi Nakai; Kazuhide Nagashima; David Nesvorný; Ann Nguyen; Larry Nittler; Morihiko Onose; Andreas Pack; Changkun Park; Laurette Piani; Liping Qin; Sara S. Russell; Naoya Sakamoto; Maria Schönbächler; Lauren Tafla; Haolan Tang; Kentaro Terada; Yasuko Terada; Tomohiro Usui; Sohei Wada; Meenakshi Wadhwa; Richard J. Walker; Katsuyuki Yamashita; Qing Zhu Yin; Shigekazu Yoneda; Edward D. Young; Hiroharu Yui; Ai Cheng Zhang; Tomoki Nakamura; Hiroshi Naraoka; Takaaki Noguchi; Ryuji Okazaki; Kanako Sakamoto; Hikaru Yabuta; Masanao Abe; Akiko Miyazaki; Aiko Nakato; Masahiro Nishimura; Tatsuaki Okada; Toru Yada; Kasumi Yogata; Satoru Nakazawa; Takanao Saiki; Satoshi Tanaka; Fuyuto Terui; Yuichi Tsuda; Sei ichiro Watanabe; Makoto Yoshikawa; Shogo Tachibana; Hisayoshi Yurimoto
  Icarus, 409, Feb. 2024, [Peer-reviewed], ［Internationally co-authored］, [International Magazine]
  Scientific journal
• Pressure dependence of metal–silicate partitioning explains the mantle phosphorus abundance
  Nagi Ikuta; Naoya Sakamoto; Shoh Tagawa; Kei Hirose; Yutaro Tsutsumi; Shunpei Yokoo; Hisayoshi Yurimoto
  Scientific Reports, 14, 1, Springer Science and Business Media LLC, 12 Jan. 2024, [Peer-reviewed]
  Scientific journal, Abstract
  
  Previous experiments performed below 20 GPa suggested that the metal/silicate partition coefficient of phosphorus (P), D_P, extrapolated to typical high-pressure and -temperature conditions of the Earth’s core formation gives too high P concentration in the core unless a large amount of silicon was included in metals. Here we examined D_P between liquid metal and coexisting molten silicate at 27–61 GPa and 3820–4760 K, corresponding to conditions of core-forming metal segregation from silicate, by measuring recovered samples using a high-resolution imaging technique coupled with secondary ion mass spectrometry. The results demonstrate that the pressure dependence of D_P changes from positive to negative above 15 GPa, likely because of an increase in the coordination number of P⁵⁺ in silicate melt. With the present new partitioning data, the observed mantle P abundance may indicate ~ 0.2 wt% P in the core, consistent with the cosmo-/geochemical estimates, based on both single-stage and multi-stage core formation models without involving high amounts of silicon in metals.
• Analysis of Cation Composition in Dolomites on the Intact Particles Sampled from Asteroid Ryugu
  Mayu Morita; Hiroharu Yui; Shu Hei Urashima; Morihiko Onose; Shintaro Komatani; Izumi Nakai; Yoshinari Abe; Yasuko Terada; Hisashi Homma; Kazuko Motomura; Kiyohiro Ichida; Tetsuya Yokoyama; Kazuhide Nagashima; Jérôme Aléon; Conel M. Conel; Sachiko Amari; Yuri Amelin; Ken Ichi Bajo; Martin Bizzarro; Audrey Bouvier; Richard W. Carlson; Marc Chaussidon; Byeon Gak Choi; Nicolas Dauphas; Andrew M. Davis; Wataru Fujiya; Ryota Fukai; Ikshu Gautam; Makiko K. Haba; Yuki Hibiya; Hiroshi Hidaka; Peter Hoppe; Gary R. Huss; Tsuyoshi Iizuka; Trevor R. Ireland; Akira Ishikawa; Shoichi Itoh; Noriyuki Kawasaki; Noriko T. Kita; Kouki Kitajima; Thorsten Kleine; Sasha Krot; Ming Chang Liu; Yuki Masuda; Frédéric Moynier; Ann Nguyen; Larry Nittler; Andreas Pack; Changkun Park; Laurette Piani; Liping Qin; Tommaso Di Rocco; Sara S. Russell; Naoya Sakamoto; Maria Schönbächler; Lauren Tafla; Haolan Tang; Kentaro Terada; Tomohiro Usui; Sohei Wada; Meenakshi Wadhwa; Richard J. Walker; Katsuyuki Yamashita; Qing Zhu Yin; Shigekazu Yoneda; Edward D. Young; Ai Cheng Zhang; Tomoki Nakamura; Hiroshi Naraoka; Takaaki Noguchi; Ryuji Okazaki; Kanako Sakamoto; Hikaru Yabuta; Masanao Abe; Akiko Miyazaki; Aiko Nakato; Masahiro Nishimura; Tatsuaki Okada; Toru Yada; Kasumi Yogata; Satoru Nakazawa; Takanao Saiki; Satoshi Tanaka; Fuyuto Terui; Yuichi Tsuda; Sei Ichiro Watanabe; Makoto Yoshikawa; Shogo Tachibana; Hisayoshi Yurimoto
  Analytical Chemistry, 96, 1, 170, 178, 09 Jan. 2024, [Peer-reviewed]
  Scientific journal
• Plutonic Nature of a Transcrustal Magmatic System: Evidence from Ultrahigh Resolution Sr-Disequilibria in Plagioclase Microantecrysts from the Southern Taupo Volcanic Zone, New Zealand
  Daniel A Coulthard Jr; Raimundo Brahm; Charline Lormand; Georg F Zellmer; Naoya Sakamoto; Yoshiyuki Iizuka; Hisayoshi Yurimoto
  Journal of Petrology, 65, 1, Oxford University Press (OUP), 13 Dec. 2023, [Peer-reviewed]
  Scientific journal, Abstract
  
  The residence timescales of antecrystic minerals contribute a key piece of information regarding the petrologic evolution of transcrustal magmatic systems and may be inferred using a combination of observations derived from microanalytical chemistry and diffusion modelling. Here, we present state-of-the-art stacked CMOS-type active pixel sensor (SCAPS) isotopographic images of tephra-hosted plagioclase microantecrysts from Tongariro Volcanic Centre in the southern Taupo Volcanic Zone, New Zealand. These crystals exhibit high-frequency Sr and anorthite zonation at sub-micron spatial resolution. We also find that all crystals display high-frequency intracrystalline Sr chemical potential variations, indicating that they have not resided at magmatic temperature for diffusive relaxation to advance significantly. To quantify crystal residence times at the well-constrained magmatic temperatures of these tephras, we first forward-modeled intracrystalline Sr diffusion over time using numerical methods. Results were then analyzed using novel spatial Fourier-transform techniques developed to understand the systematics the diffusive decay of Sr disequilibria in the spatial frequency domain. This ultimately permitted the estimation of Sr concentration profiles at crystal formation, prior to uptake into the carrier melt at the onset of eruption. Our data imply residence times of hours to days for the studied microantecrysts. This is inconsistent with long antecryst residence times in magmatic mushes at elevated temperatures, pointing instead to a cool plutonic nature of the magmatic plumbing system beneath the southern Taupo Volcanic Zone.
• Neodymium‐142 deficits and samarium neutron stratigraphy of C‐type asteroid (162173) Ryugu
  Zachary A. Torrano; Michelle K. Jordan; Timothy D. Mock; Richard W. Carlson; Ikshu Gautam; Makiko K. Haba; Tetsuya Yokoyama; Yoshinari Abe; Jérôme Aléon; Conel Alexander; Sachiko Amari; Yuri Amelin; Ken‐ichi Bajo; Martin Bizzarro; Audrey Bouvier; Marc Chaussidon; Byeon‐Gak Choi; Nicolas Dauphas; Andrew M. Davis; Tommaso Di Rocco; Wataru Fujiya; Ryota Fukai; Yuki Hibiya; Hiroshi Hidaka; Hisashi Homma; Peter Hoppe; Gary R. Huss; Kiyohiro Ichida; Tsuyoshi Iizuka; Trevor Ireland; Akira Ishikawa; Shoichi Itoh; Noriyuki Kawasaki; Noriko T. Kita; Koki Kitajima; Thorsten Kleine; Shintaro Komatani; Alexander N. Krot; Ming‐Chang Liu; Yuki Masuda; Kevin D. McKeegan; Mayu Morita; Kazuko Motomura; Frédéric Moynier; Izumi Nakai; Kazuhide Nagashima; Ann Nguyen; Larry Nittler; Morihiko Onose; Andreas Pack; Changkun Park; Laurette Piani; Liping Qin; Sara Russell; Naoya Sakamoto; Maria Schönbächler; Lauren Tafla; Haolan Tang; Kentaro Terada; Yasuko Terada; Tomohiro Usui; Sohei Wada; Meenakshi Wadhwa; Richard J. Walker; Katsuyuki Yamashita; Qing‐Zhu Yin; Shigekazu Yoneda; Edward D. Young; Hiroharu Yui; Ai‐Cheng Zhang; Tomoki Nakamura; Hiroshi Naraoka; Takaaki Noguchi; Ryuji Okazaki; Kanako Sakamoto; Hikaru Yabuta; Masanao Abe; Akiko Miyazaki; Aiko Nakato; Masahiro Nishimura; Tatsuaki Okada; Toru Yada; Kasumi Yogata; Satoru Nakazawa; Takanao Saiki; Satoshi Tanaka; Fuyuto Terui; Yuichi Tsuda; Sei‐ichiro Watanabe; Makoto Yoshikawa; Shogo Tachibana; Hisayoshi Yurimoto
  METEORITICS & PLANETARY SCIENCE, Wiley, 07 Dec. 2023, [Peer-reviewed]
  Scientific journal, Abstract
  
  We report Nd and Sm isotopic compositions of four samples of Ryugu returned by the Hayabusa2 mission, including “A” (first touchdown) and “C” (second touchdown) samples, and several carbonaceous chondrites to evaluate potential genetic relationships between Ryugu and known chondrite groups and track the cosmic ray exposure history of Ryugu. We resolved Nd and Sm isotopic anomalies in small (<20 ng Nd and Sm) sample sizes via thermal ionization mass spectrometer using 10¹³ Ω amplifiers. Ryugu samples exhibit resolvable negative μ¹⁴²Nd values consistent with carbonaceous chondrite values, suggesting that Ryugu is related to the parent bodies of carbonaceous chondrites. Ryugu's negative μ¹⁴⁹Sm values are the result of exposure to galactic cosmic rays, as demonstrated by the correlation between ¹⁵⁰Sm/¹⁵²Sm and ¹⁴⁹Sm/¹⁵²Sm ratios that fall along the expected neutron capture correlation line. The neutron fluence calculated in the “A” samples (2.75 ± 1.94 × 10¹⁵ n cm⁻²) is slightly higher compared to the “C” samples (0.95 ± 2.04 × 10¹⁵ n cm⁻²), though overlapping within measurement uncertainty. The Sm results for Ryugu, at this level of precision, thus are consistent with a well‐mixed surface layer at least to the depths from which the “A” and “C” samples derive.
• The Magnesium Isotope Composition of Samples Returned from Asteroid Ryugu
  Martin Bizzarro; Martin Schiller; Tetsuya Yokoyama; Yoshinari Abe; Jérôme Aléon; Conel M. O’D. Alexander; Sachiko Amari; Yuri Amelin; Ken-ichi Bajo; Audrey Bouvier; Richard W. Carlson; Marc Chaussidon; Byeon-Gak Choi; Nicolas Dauphas; Andrew M. Davis; Tommaso Di Rocco; Wataru Fujiya; Ryota Fukai; Ikshu Gautam; Makiko K. Haba; Yuki Hibiya; Hiroshi Hidaka; Hisashi Homma; Peter Hoppe; Gary R. Huss; Kiyohiro Ichida; Tsuyoshi Iizuka; Trevor R. Ireland; Akira Ishikawa; Shoichi Itoh; Noriyuki Kawasaki; Noriko T. Kita; Kouki Kitajima; Thorsten Kleine; Shintaro Komatani; Alexander N. Krot; Ming-Chang Liu; Yuki Masuda; Mayu Morita; Fréderic Moynier; Kazuko Motomura; Izumi Nakai; Kazuhide Nagashima; David Nesvorný; Ann Nguyen; Larry Nittler; Morihiko Onose; Andreas Pack; Changkun Park; Laurette Piani; Liping Qin; Sara S. Russell; Naoya Sakamoto; Maria Schönbächler; Lauren Tafla; Haolan Tang; Kentaro Terada; Yasuko Terada; Tomohiro Usui; Sohei Wada; Meenakshi Wadhwa; Richard J. Walker; Katsuyuki Yamashita; Qing-Zhu Yin; Shigekazu Yoneda; Edward D. Young; Hiroharu Yui; Ai-Cheng Zhang; Tomoki Nakamura; Hiroshi Naraoka; Takaaki Noguchi; Ryuji Okazaki; Kanako Sakamoto; Hikaru Yabuta; Masanao Abe; Akiko Miyazaki; Aiko Nakato; Masahiro Nishimura; Tatsuaki Okada; Toru Yada; Kasumi Yogata; Satoru Nakazawa; Takanao Saiki; Satoshi Tanaka; Fuyuto Terui; Yuichi Tsuda; Sei-ichiro Watanabe; Makoto Yoshikawa; Shogo Tachibana; Hisayoshi Yurimoto
  The Astrophysical Journal Letters, 958, 2, L25, L25, American Astronomical Society, 24 Nov. 2023
  Scientific journal, Abstract
  
  The nucleosynthetic isotope composition of planetary materials provides a record of the heterogeneous distribution of stardust within the early solar system. In 2020 December, the Japan Aerospace Exploration Agency Hayabusa2 spacecraft returned to Earth the first samples of a primitive asteroid, namely, the Cb-type asteroid Ryugu. This provides a unique opportunity to explore the kinship between primitive asteroids and carbonaceous chondrites. We report high-precision μ²⁶Mg* and μ²⁵Mg values of Ryugu samples together with those of CI, CM, CV, and ungrouped carbonaceous chondrites. The stable Mg isotope composition of Ryugu aliquots defines μ²⁵Mg values ranging from –160 ± 20 ppm to –272 ± 30 ppm, which extends to lighter compositions relative to Ivuna-type (CI) and other carbonaceous chondrite groups. We interpret the μ²⁵Mg variability as reflecting heterogeneous sampling of a carbonate phase hosting isotopically light Mg (μ²⁵Mg ∼ –1400 ppm) formed by low temperature equilibrium processes. After correcting for this effect, Ryugu samples return homogeneous μ²⁶Mg* values corresponding to a weighted mean of 7.1 ± 0.8 ppm. Thus, Ryugu defines a μ²⁶Mg* excess relative to the CI and CR chondrite reservoirs corresponding to 3.8 ± 1.1 and 11.9 ± 0.8 ppm, respectively. These variations cannot be accounted for by in situ decay of ²⁶Al given their respective ²⁷Al/²⁴Mg ratios. Instead, it requires that Ryugu and the CI and CR parent bodies formed from material with a different initial ²⁶Al/²⁷Al ratio or that they are sourced from material with distinct Mg isotope compositions. Thus, our new Mg isotope data challenge the notion that Ryugu and CI chondrites share a common nucleosynthetic heritage.
• Water circulation in Ryugu asteroid affected the distribution of nucleosynthetic isotope anomalies in returned sample
  Tetsuya Yokoyama; Meenakshi Wadhwa; Tsuyoshi Iizuka; Vinai Rai; Ikshu Gautam; Yuki Hibiya; Yuki Masuda; Makiko K. Haba; Ryota Fukai; Rebekah Hines; Nicole Phelan; Yoshinari Abe; Jérôme Aléon; Conel M. O’D. Alexander; Sachiko Amari; Yuri Amelin; Ken-ichi Bajo; Martin Bizzarro; Audrey Bouvier; Richard W. Carlson; Marc Chaussidon; Byeon-Gak Choi; Nicolas Dauphas; Andrew M. Davis; Tommaso Di Rocco; Wataru Fujiya; Hiroshi Hidaka; Hisashi Homma; Peter Hoppe; Gary R. Huss; Kiyohiro Ichida; Trevor Ireland; Akira Ishikawa; Shoichi Itoh; Noriyuki Kawasaki; Noriko T. Kita; Koki Kitajima; Thorsten Kleine; Shintaro Komatani; Alexander N. Krot; Ming-Chang Liu; Kevin D. McKeegan; Mayu Morita; Kazuko Motomura; Frédéric Moynier; Izumi Nakai; Kazuhide Nagashima; Ann Nguyen; Larry Nittler; Morihiko Onose; Andreas Pack; Changkun Park; Laurette Piani; Liping Qin; Sara Russell; Naoya Sakamoto; Maria Schönbächler; Lauren Tafla; Haolan Tang; Kentaro Terada; Yasuko Terada; Tomohiro Usui; Sohei Wada; Richard J. Walker; Katsuyuki Yamashita; Qing-Zhu Yin; Shigekazu Yoneda; Edward D. Young; Hiroharu Yui; Ai-Cheng Zhang; Tomoki Nakamura; Hiroshi Naraoka; Takaaki Noguchi; Ryuji Okazaki; Kanako Sakamoto; Hikaru Yabuta; Masanao Abe; Akiko Miyazaki; Aiko Nakato; Masahiro Nishimura; Tatsuaki Okada; Toru Yada; Kasumi Yogata; Satoru Nakazawa; Takanao Saiki; Satoshi Tanaka; Fuyuto Terui; Yuichi Tsuda; Sei-ichiro Watanabe; Makoto Yoshikawa; Shogo Tachibana; Hisayoshi Yurimoto
  Science Advances, 9, 45, American Association for the Advancement of Science (AAAS), 10 Nov. 2023
  Scientific journal, Studies of material returned from Cb asteroid Ryugu have revealed considerable mineralogical and chemical heterogeneity, stemming primarily from brecciation and aqueous alteration. Isotopic anomalies could have also been affected by delivery of exogenous clasts and aqueous mobilization of soluble elements. Here, we show that isotopic anomalies for mildly soluble Cr are highly variable in Ryugu and CI chondrites, whereas those of Ti are relatively uniform. This variation in Cr isotope ratios is most likely due to physicochemical fractionation between ⁵⁴ Cr-rich presolar nanoparticles and Cr-bearing secondary minerals at the millimeter-scale in the bulk samples, likely due to extensive aqueous alteration in their parent bodies that occurred after Solar System birth. In contrast, Ti isotopes were marginally affected by this process. Our results show that isotopic heterogeneities in asteroids are not all nebular or accretionary in nature but can also reflect element redistribution by water.
• The Oxygen Isotopic Composition of Samples Returned from Asteroid Ryugu with Implications for the Nature of the Parent Planetesimal
  Haolan Tang; Edward D. Young; Lauren Tafla; Andreas Pack; Tommaso Di Rocco; Yoshinari Abe; Jérôme Aléon; Conel M. O’D. Alexander; Sachiko Amari; Yuri Amelin; Ken-ichi Bajo; Martin Bizzarro; Audrey Bouvier; Richard W. Carlson; Marc Chaussidon; Byeon-Gak Choi; Nicolas Dauphas; Andrew M. Davis; Wataru Fujiya; Ryota Fukai; Ikshu Gautam; Makiko K. Haba; Yuki Hibiya; Hiroshi Hidaka; Hisashi Homma; Peter Hoppe; Gary R. Huss; Kiyohiro Ichida; Tsuyoshi Iizuka; Trevor R. Ireland; Akira Ishikawa; Motoo Ito; Shoichi Itoh; Noriyuki Kawasaki; Noriko T. Kita; Kouki Kitajima; Thorsten Kleine; Shintaro Komatani; Alexander N. Krot; Ming-Chang Liu; Yuki Masuda; Kevin D. McKeegan; Mayu Morita; Kazuko Motomura; Frédéric Moynier; Kazuhide Nagashima; Izumi Nakai; Ann Nguyen; Larry Nittler; Morihiko Onose; Changkun Park; Laurette Piani; Liping Qin; Sara S. Russell; Naoya Sakamoto; Maria Schönbächler; Kentaro Terada; Yasuko Terada; Tomohiro Usui; Sohei Wada; Meenakshi Wadhwa; Richard J. Walker; Katsuyuki Yamashita; Qing-Zhu Yin; Tetsuya Yokoyama; Shigekazu Yoneda; Hiroharu Yui; Ai-Cheng Zhang; Tomoki Nakamura; Hiroshi Naraoka; Takaaki Noguchi; Ryuji Okazaki; Kanako Sakamoto; Hikaru Yabuta; Masanao Abe; Akiko Miyazaki; Aiko Nakato; Masahiro Nishimura; Tatsuaki Okada; Toru Yada; Kasumi Yogata; Satoru Nakazawa; Takanao Saiki; Satoshi Tanaka; Fuyuto Terui; Yuichi Tsuda; Sei-ichiro Watanabe; Makoto Yoshikawa; Shogo Tachibana; Hisayoshi Yurimoto
  The Planetary Science Journal, 4, 8, 144, 144, 01 Aug. 2023
  English, Scientific journal
• Abundant presolar grains and primordial organics preserved in carbon-rich exogenous clasts in asteroid Ryugu
  Ann. N. Nguyen; Prajkta Mane; Lindsay P. Keller; Laurette Piani; Yoshinari Abe; Jérôme Aléon; Conel M. O'D. Alexander; Sachiko Amari; Yuri Amelin; Ken-ichi Bajo; Martin Bizzarro; Audrey Bouvier; Richard W. Carlson; Marc Chaussidon; Byeon-Gak Choi; Nicolas Dauphas; Andrew M. Davis; Tommaso Di Rocco; Wataru Fujiya; Ryota Fukai; Ikshu Gautam; Makiko K. Haba; Yuki Hibiya; Hiroshi Hidaka; Hisashi Homma; Peter Hoppe; Gary R. Huss; Kiyohiro Ichida; Tsuyoshi Iizuka; Trevor R. Ireland; Akira Ishikawa; Shoichi Itoh; Noriyuki Kawasaki; Noriko T. Kita; Kouki Kitajima; Thorsten Kleine; Shintaro Komatani; Alexander N. Krot; Ming-Chang Liu; Yuki Masuda; Kevin D. McKeegan; Mayu Morita; Kazuko Motomura; Frédéric Moynier; Izumi Nakai; Kazuhide Nagashima; David Nesvorný; Larry Nittler; Morihiko Onose; Andreas Pack; Changkun Park; Liping Qin; Sara S. Russell; Naoya Sakamoto; Maria Schönbächler; Lauren Tafla; Haolan Tang; Kentaro Terada; Yasuko Terada; Tomohiro Usui; Sohei Wada; Meenakshi Wadhwa; Richard J. Walker; Katsuyuki Yamashita; Qing-Zhu Yin; Tetsuya Yokoyama; Shigekazu Yoneda; Edward D. Young; Hiroharu Yui; Ai-Cheng Zhang; Tomoki Nakamura; Hiroshi Naraoka; Takaaki Noguchi; Ryuji Okazaki; Kanako Sakamoto; Hikaru Yabuta; Masanao Abe; Akiko Miyazaki; Aiko Nakato; Masahiro Nishimura; Tatsuaki Okada; Toru Yada; Kasumi Yogata; Satoru Nakazawa; Takanao Saiki; Satoshi Tanaka; Fuyuto Terui; Yuichi Tsuda; Sei-ichiro Watanabe; Makoto Yoshikawa; Shogo Tachibana; Hisayoshi Yurimoto
  Science Advances, 9, 28, 14 Jul. 2023
  English, Scientific journal
• Carbonate record of temporal change in oxygen fugacity and gaseous species in asteroid Ryugu
  Wataru Fujiya; Noriyuki Kawasaki; Kazuhide Nagashima; Naoya Sakamoto; Conel M. O’D. Alexander; Noriko T. Kita; Kouki Kitajima; Yoshinari Abe; Jérôme Aléon; Sachiko Amari; Yuri Amelin; Ken-ichi Bajo; Martin Bizzarro; Audrey Bouvier; Richard W. Carlson; Marc Chaussidon; Byeon-Gak Choi; Nicolas Dauphas; Andrew M. Davis; Tommaso Di Rocco; Ryota Fukai; Ikshu Gautam; Makiko K. Haba; Yuki Hibiya; Hiroshi Hidaka; Hisashi Homma; Peter Hoppe; Gary R. Huss; Kiyohiro Ichida; Tsuyoshi Iizuka; Trevor R. Ireland; Akira Ishikawa; Shoichi Itoh; Thorsten Kleine; Shintaro Komatani; Alexander N. Krot; Ming-Chang Liu; Yuki Masuda; Kevin D. McKeegan; Mayu Morita; Kazuko Motomura; Frédéric Moynier; Izumi Nakai; Ann Nguyen; Larry Nittler; Morihiko Onose; Andreas Pack; Changkun Park; Laurette Piani; Liping Qin; Sara S. Russell; Maria Schönbächler; Lauren Tafla; Haolan Tang; Kentaro Terada; Yasuko Terada; Tomohiro Usui; Sohei Wada; Meenakshi Wadhwa; Richard J. Walker; Katsuyuki Yamashita; Qing-Zhu Yin; Tetsuya Yokoyama; Shigekazu Yoneda; Edward D. Young; Hiroharu Yui; Ai-Cheng Zhang; Tomoki Nakamura; Hiroshi Naraoka; Takaaki Noguchi; Ryuji Okazaki; Kanako Sakamoto; Hikaru Yabuta; Masanao Abe; Akiko Miyazaki; Aiko Nakato; Masahiro Nishimura; Tatsuaki Okada; Toru Yada; Kasumi Yogata; Satoru Nakazawa; Takanao Saiki; Satoshi Tanaka; Fuyuto Terui; Yuichi Tsuda; Sei-ichiro Watanabe; Makoto Yoshikawa; Shogo Tachibana; Hisayoshi Yurimoto
  Nature Geoscience, 16, 8, 675, 682, Springer Science and Business Media LLC, 10 Jul. 2023
  Scientific journal
• ²⁶ A l– ²⁶ M g chronology of high‐temperature condensate hibonite in a fine‐grained, C a ‐A l‐rich inclusion from reduced CV chondrite
  Noriyuki Kawasaki; Daiki Yamamoto; Sohei Wada; Changkun Park; Hwayoung Kim; Naoya Sakamoto; Hisayoshi Yurimoto
  METEORITICS & PLANETARY SCIENCE, Wiley, 15 May 2023
  Scientific journal
• Hydrogen Isotopic Composition of Hydrous Minerals in Asteroid Ryugu
  Laurette Piani; Kazuhide Nagashima; Noriyuki Kawasaki; Naoya Sakamoto; Ken-ichi Bajo; Yoshinari Abe; Jérôme Aléon; Conel M. O’D. Alexander; Sachiko Amari; Yuri Amelin; Martin Bizzarro; Audrey Bouvier; Richard W. Carlson; Marc Chaussidon; Byeon-Gak Choi; Nicolas Dauphas; Andrew M. Davis; Tommaso Di Rocco; Wataru Fujiya; Ryota Fukai; Ikshu Gautam; Makiko K. Haba; Yuki Hibiya; Hiroshi Hidaka; Hisashi Homma; Peter Hoppe; Gary R. Huss; Kiyohiro Ichida; Tsuyoshi Iizuka; Trevor R. Ireland; Akira Ishikawa; Shoichi Itoh; Noriko T. Kita; Kouki Kitajima; Thorsten Kleine; Shintaro Komatani; Alexander N. Krot; Ming-Chang Liu; Yuki Masuda; Kevin D. McKeegan; Mayu Morita; Kazuko Motomura; Frédéric Moynier; Izumi Nakai; Ann Nguyen; Larry Nittler; Morihiko Onose; Andreas Pack; Changkun Park; Liping Qin; Sara S. Russell; Maria Schönbächler; Lauren Tafla; Haolan Tang; Kentaro Terada; Yasuko Terada; Tomohiro Usui; Sohei Wada; Meenakshi Wadhwa; Richard J. Walker; Katsuyuki Yamashita; Qing-Zhu Yin; Tetsuya Yokoyama; Shigekazu Yoneda; Edward D. Young; Hiroharu Yui; Ai-Cheng Zhang; Tomoki Nakamura; Hiroshi Naraoka; Ryuji Okazaki; Kanako Sakamoto; Hikaru Yabuta; Masanao Abe; Akiko Miyazaki; Aiko Nakato; Masahiro Nishimura; Tatsuaki Okada; Toru Yada; Kasumi Yogata; Satoru Nakazawa; Takanao Saiki; Satoshi Tanaka; Fuyuto Terui; Yuichi Tsuda; Sei-ichiro Watanabe; Makoto Yoshikawa; Shogo Tachibana; Hisayoshi Yurimoto
  The Astrophysical Journal Letters, 946, 2, L43, L43, American Astronomical Society, 01 Apr. 2023, [Peer-reviewed]
  Scientific journal, Abstract
  
  Rock fragments of the Cb-type asteroid Ryugu returned to Earth by the JAXA Hayabusa2 mission share mineralogical, chemical, and isotopic properties with the Ivuna-type (CI) carbonaceous chondrites. Similar to CI chondrites, these fragments underwent extensive aqueous alteration and consist predominantly of hydrous minerals likely formed in the presence of liquid water on the Ryugu parent asteroid. Here we present an in situ analytical survey performed by secondary ion mass spectrometry from which we have estimated the D/H ratio of Ryugu’s hydrous minerals, D/H_Ryugu, to be [165 ± 19] × 10⁻⁶, which corresponds to δD_Ryugu = +59 ± 121‰ (2σ). The hydrous mineral D/H_Ryugu’s values for the two sampling sites on Ryugu are similar; they are also similar to the estimated D/H ratio of hydrous minerals in the CI chondrites Orgueil and Alais. This result reinforces a link between Ryugu and CI chondrites and an inference that Ryugu’s samples, which avoided terrestrial contamination, are our best proxy to estimate the composition of water at the origin of hydrous minerals in CI-like material. Based on this data and recent literature studies, the contribution of CI chondrites to the hydrogen of Earth’s surficial reservoirs is evaluated to be ∼3%. We conclude that the water responsible for the alteration of Ryugu’s rocks was derived from water ice precursors inherited from the interstellar medium; the ice partially re-equilibrated its hydrogen with the nebular H₂ before being accreted on the Ryugu’s parent asteroid.
• A dehydrated space-weathered skin cloaking the hydrated interior of Ryugu
  Noguchi, Takaaki; Matsumoto, Toru; Miyake, Akira; Igami, Yohei; Haruta, Mitsutaka; Saito, Hikaru; Hata, Satoshi; Seto, Yusuke; Miyahara, Masaaki; Tomioka, Naotaka; Ishii, Hope A.; Bradley, John P.; Ohtaki, Kenta K.; Dobrică, Elena; Leroux, Hugues; Le Guillou, Corentin; Jacob, Damien; de la Peña, Francisco; Laforet, Sylvain; Marinova, Maya; Langenhorst, Falko; Harries, Dennis; Beck, Pierre; Phan, Thi H. V.; Rebois, Rolando; Abreu, Neyda M.; Gray, Jennifer; Zega, Thomas; Zanetta, Pierre-M.; Thompson, Michelle S.; Stroud, Rhonda; Burgess, Kate; Cymes, Brittany A.; Bridges, John C.; Hicks, Leon; Lee, Martin R.; Daly, Luke; Bland, Phil A.; Zolensky, Michael E.; Frank, David R.; Martinez, James; Tsuchiyama, Akira; Yasutake, Masahiro; Matsuno, Junya; Okumura, Shota; Mitsukawa, Itaru; Uesugi, Kentaro; Uesugi, Masayuki; Takeuchi, Akihisa; Sun, Mingqi; Enju, Satomi; Takigawa, Aki; Michikami, Tatsuhiro; Nakamura, Tomoki; Matsumoto, Megumi; Nakauchi, Yusuke; Abe, Masanao; Arakawa, Masahiko; Fujii, Atsushi; Hayakawa, Masahiko; Hirata, Naru; Hirata, Naoyuki; Honda, Rie; Honda, Chikatoshi; Hosoda, Satoshi; Iijima, Yu-ichi; Ikeda, Hitoshi; Ishiguro, Masateru; Ishihara, Yoshiaki; Iwata, Takahiro; Kawahara, Kousuke; Kikuchi, Shota; Kitazato, Kohei; Matsumoto, Koji; Matsuoka, Moe; Mimasu, Yuya; Miura, Akira; Morota, Tomokatsu; Nakazawa, Satoru; Namiki, Noriyuki; Noda, Hirotomo; Noguchi, Rina; Ogawa, Naoko; Ogawa, Kazunori; Okada, Tatsuaki; Okamoto, Chisato; Ono, Go; Ozaki, Masanobu; Saiki, Takanao; Sakatani, Naoya; Sawada, Hirotaka; Senshu, Hiroki; Shimaki, Yuri; Shirai, Kei; Sugita, Seiji; Takei, Yuto; Takeuchi, Hiroshi; Tanaka, Satoshi; Tatsumi, Eri; Terui, Fuyuto; Tsukizaki, Ryudo; Wada, Koji; Yamada, Manabu; Yamada, Tetsuya; Yamamoto, Yukio; Yano, Hajime; Yokota, Yasuhiro; Yoshihara, Keisuke; Yoshikawa, Makoto; Yoshikawa, Kent; Fukai, Ryohta; Furuya, Shizuho; Hatakeda, Kentaro; Hayashi, Tasuku; Hitomi, Yuya; Kumagai, Kazuya; Miyazaki, Akiko; Nakato, Aiko; Nishimura, Masahiro; Soejima, Hiromichi; Suzuki, Ayako I.; Usui, Tomohiro; Yada, Toru; Yamamoto, Daiki; Yogata, Kasumi; Yoshitake, Miwa; Connolly, Harold C.; Lauretta, Dante S.; Yurimoto, Hisayoshi; Nagashima, Kazuhide; Kawasaki, Noriyuki; Sakamoto, Naoya; Okazaki, Ryuji; Yabuta, Hikaru; Naraoka, Hiroshi; Sakamoto, Kanako; Tachibana, Shogo; Watanabe, Sei-ichiro; Tsuda, Yuichi
  Nature Astronomy, 7, 2, 170, 181, Feb. 2023
  English, Scientific journal, Without a protective atmosphere, space-exposed surfaces of airless Solar System bodies gradually experience an alteration in composition, structure and optical properties through a collective process called space weathering. The return of samples from near-Earth asteroid (162173) Ryugu by Hayabusa2 provides the first opportunity for laboratory study of space-weathering signatures on the most abundant type of inner solar system body: a C-type asteroid, composed of materials largely unchanged since the formation of the Solar System. Weathered Ryugu grains show areas of surface amorphization and partial melting of phyllosilicates, in which reduction from Fe³⁺ to Fe²⁺ and dehydration developed. Space weathering probably contributed to dehydration by dehydroxylation of Ryugu surface phyllosilicates that had already lost interlayer water molecules and to weakening of the 2.7 µm hydroxyl (–OH) band in reflectance spectra. For C-type asteroids in general, this indicates that a weak 2.7 µm band can signify space-weathering-induced surface dehydration, rather than bulk volatile loss.
• Oxygen isotopes of anhydrous primary minerals show kinship between asteroid Ryugu and comet 81P/Wild2
  Noriyuki Kawasaki; Kazuhide Nagashima; Naoya Sakamoto; Toru Matsumoto; Ken-ichi Bajo; Sohei Wada; Yohei Igami; Akira Miyake; Takaaki Noguchi; Daiki Yamamoto; Sara S. Russell; Yoshinari Abe; Jérôme Aléon; Conel M. O’D. Alexander; Sachiko Amari; Yuri Amelin; Martin Bizzarro; Audrey Bouvier; Richard W. Carlson; Marc Chaussidon; Byeon-Gak Choi; Nicolas Dauphas; Andrew M. Davis; Tommaso Di Rocco; Wataru Fujiya; Ryota Fukai; Ikshu Gautam; Makiko K. Haba; Yuki Hibiya; Hiroshi Hidaka; Hisashi Homma; Peter Hoppe; Gary R. Huss; Kiyohiro Ichida; Tsuyoshi Iizuka; Trevor R. Ireland; Akira Ishikawa; Motoo Ito; Shoichi Itoh; Noriko T. Kita; Kouki Kitajima; Thorsten Kleine; Shintaro Komatani; Alexander N. Krot; Ming-Chang Liu; Yuki Masuda; Kevin D. McKeegan; Mayu Morita; Kazuko Motomura; Frédéric Moynier; Izumi Nakai; Ann Nguyen; Larry Nittler; Morihiko Onose; Andreas Pack; Changkun Park; Laurette Piani; Liping Qin; Maria Schönbächler; Lauren Tafla; Haolan Tang; Kentaro Terada; Yasuko Terada; Tomohiro Usui; Meenakshi Wadhwa; Richard J. Walker; Katsuyuki Yamashita; Qing-Zhu Yin; Tetsuya Yokoyama; Shigekazu Yoneda; Edward D. Young; Hiroharu Yui; Ai-Cheng Zhang; Tomoki Nakamura; Hiroshi Naraoka; Ryuji Okazaki; Kanako Sakamoto; Hikaru Yabuta; Masanao Abe; Akiko Miyazaki; Aiko Nakato; Masahiro Nishimura; Tatsuaki Okada; Toru Yada; Kasumi Yogata; Satoru Nakazawa; Takanao Saiki; Satoshi Tanaka; Fuyuto Terui; Yuichi Tsuda; Sei-ichiro Watanabe; Makoto Yoshikawa; Shogo Tachibana; Hisayoshi Yurimoto
  Science Advances, 8, 50, American Association for the Advancement of Science (AAAS), 16 Dec. 2022
  Scientific journal, The extraterrestrial materials returned from asteroid (162173) Ryugu consist predominantly of low-temperature aqueously formed secondary minerals and are chemically and mineralogically similar to CI (Ivuna-type) carbonaceous chondrites. Here, we show that high-temperature anhydrous primary minerals in Ryugu and CI chondrites exhibit a bimodal distribution of oxygen isotopic compositions: ¹⁶ O-rich (associated with refractory inclusions) and ¹⁶ O-poor (associated with chondrules). Both the ¹⁶ O-rich and ¹⁶ O-poor minerals probably formed in the inner solar protoplanetary disk and were subsequently transported outward. The abundance ratios of the ¹⁶ O-rich to ¹⁶ O-poor minerals in Ryugu and CI chondrites are higher than in other carbonaceous chondrite groups but are similar to that of comet 81P/Wild2, suggesting that Ryugu and CI chondrites accreted in the outer Solar System closer to the accretion region of comets.
• Contribution of Ryugu-like material to Earth's volatile inventory by Cu and Zn isotopic analysis
  Paquet, Marine; Moynier, Frederic; Yokoyama, Tetsuya; Dai, Wei; Hu, Yan; Abe, Yoshinari; Aleon, Jerome; O'D. Alexander, Conel M.; Amari, Sachiko; Amelin, Yuri; Bajo, Ken-ichi; Bizzarro, Martin; Bouvier, Audrey; Carlson, Richard W.; Chaussidon, Marc; Choi, Byeon-Gak; Dauphas, Nicolas; Davis, Andrew M.; Di Rocco, Tommaso; Fujiya, Wataru; Fukai, Ryota; Gautam, Ikshu; Haba, Makiko K.; Hibiya, Yuki; Hidaka, Hiroshi; Homma, Hisashi; Hoppe, Peter; Huss, Gary R.; Ichida, Kiyohiro; Iizuka, Tsuyoshi; Ireland, Trevor R.; Ishikawa, Akira; Ito, Motoo; Itoh, Shoichi; Kawasaki, Noriyuki; Kita, Noriko T.; Kitajima, Kouki; Kleine, Thorsten; Komatani, Shintaro; Krot, Alexander N.; Liu, Ming-Chang; Masuda, Yuki; McKeegan, Kevin D.; Morita, Mayu; Motomura, Kazuko; Nakai, Izumi; Nagashima, Kazuhide; Nesvorny, David; Nguyen, Ann N.; Nittler, Larry; Onose, Morihiko; Pack, Andreas; Park, Changkun; Piani, Laurette; Qin, Liping; Russell, Sara S.; Sakamoto, Naoya; Schoenbaechler, Maria; Tafla, Lauren; Tang, Haolan; Terada, Kentaro; Terada, Yasuko; Usui, Tomohiro; Wada, Sohei; Wadhwa, Meenakshi; Walker, Richard J.; Yamashita, Katsuyuki; Yin, Qing-Zhu; Yoneda, Shigekazu; Young, Edward D.; Yui, Hiroharu; Zhang, Ai-Cheng; Nakamura, Tomoki; Naraoka, Hiroshi; Noguchi, Takaaki; Okazaki, Ryuji; Sakamoto, Kanako; Yabuta, Hikaru; Abe, Masanao; Miyazaki, Akiko; Nakato, Aiko; Nishimura, Masahiro; Okada, Tatsuaki; Yada, Toru; Yogata, Kasumi; Nakazawa, Satoru; Saiki, Takanao; Tanaka, Satoshi; Terui, Fuyuto; Tsuda, Yuichi; Watanabe, Sei-ichiro; Yoshikawa, Makoto; Tachibana, Shogo; Yurimoto, Hisayoshi
  Nature astronomy, 7, 2, 182, 189, 12 Dec. 2022
  English, Scientific journal, Initial analyses showed that asteroid Ryugu's composition is close to CI (Ivuna-like) carbonaceous chondrites (CCs) - the chemically most primitive meteorites, characterized by near-solar abundances for most elements. However, some isotopic signatures (for example, Ti, Cr) overlap with other CC groups, so the details of the link between Ryugu and the CI chondrites are not yet fully clear. Here we show that Ryugu and CI chondrites have the same zinc and copper isotopic composition. As the various chondrite groups have very distinct Zn and Cu isotopic signatures, our results point at a common genetic heritage between Ryugu and CI chondrites, ruling out any affinity with other CC groups. Since Ryugu's pristine samples match the solar elemental composition for many elements, their Zn and Cu isotopic compositions likely represent the best estimates of the solar composition. Earth's mass-independent Zn isotopic composition is intermediate between Ryugu/CC and non-carbonaceous chondrites (NCs), suggesting a contribution of Ryugu-like material to Earth's budgets of Zn and other moderately volatile elements.
• Ryugu's nucleosynthetic heritage from the outskirts of the Solar System.
  Timo Hopp; Nicolas Dauphas; Yoshinari Abe; Jérôme Aléon; Conel M O'D Alexander; Sachiko Amari; Yuri Amelin; Ken-Ichi Bajo; Martin Bizzarro; Audrey Bouvier; Richard W Carlson; Marc Chaussidon; Byeon-Gak Choi; Andrew M Davis; Tommaso Di Rocco; Wataru Fujiya; Ryota Fukai; Ikshu Gautam; Makiko K Haba; Yuki Hibiya; Hiroshi Hidaka; Hisashi Homma; Peter Hoppe; Gary R Huss; Kiyohiro Ichida; Tsuyoshi Iizuka; Trevor R Ireland; Akira Ishikawa; Motoo Ito; Shoichi Itoh; Noriyuki Kawasaki; Noriko T Kita; Kouki Kitajima; Thorsten Kleine; Shintaro Komatani; Alexander N Krot; Ming-Chang Liu; Yuki Masuda; Kevin D McKeegan; Mayu Morita; Kazuko Motomura; Frédéric Moynier; Izumi Nakai; Kazuhide Nagashima; David Nesvorný; Ann Nguyen; Larry Nittler; Morihiko Onose; Andreas Pack; Changkun Park; Laurette Piani; Liping Qin; Sara S Russell; Naoya Sakamoto; Maria Schönbächler; Lauren Tafla; Haolan Tang; Kentaro Terada; Yasuko Terada; Tomohiro Usui; Sohei Wada; Meenakshi Wadhwa; Richard J Walker; Katsuyuki Yamashita; Qing-Zhu Yin; Tetsuya Yokoyama; Shigekazu Yoneda; Edward D Young; Hiroharu Yui; Ai-Cheng Zhang; Tomoki Nakamura; Hiroshi Naraoka; Takaaki Noguchi; Ryuji Okazaki; Kanako Sakamoto; Hikaru Yabuta; Masanao Abe; Akiko Miyazaki; Aiko Nakato; Masahiro Nishimura; Tatsuaki Okada; Toru Yada; Kasumi Yogata; Satoru Nakazawa; Takanao Saiki; Satoshi Tanaka; Fuyuto Terui; Yuichi Tsuda; Sei-Ichiro Watanabe; Makoto Yoshikawa; Shogo Tachibana; Hisayoshi Yurimoto
  Science advances, 8, 46, eadd8141, 20 Oct. 2022, [International Magazine]
  English, Scientific journal
• Presolar Stardust in Asteroid Ryugu
  Jens Barosch; Larry R. Nittler; Jianhua Wang; Conel M. O’D. Alexander; Bradley T. De Gregorio; Cécile Engrand; Yoko Kebukawa; Kazuhide Nagashima; Rhonda M. Stroud; Hikaru Yabuta; Yoshinari Abe; Jérôme Aléon; Sachiko Amari; Yuri Amelin; Ken-ichi Bajo; Laure Bejach; Martin Bizzarro; Lydie Bonal; Audrey Bouvier; Richard W. Carlson; Marc Chaussidon; Byeon-Gak Choi; George D. Cody; Emmanuel Dartois; Nicolas Dauphas; Andrew M. Davis; Alexandre Dazzi; Ariane Deniset-Besseau; Tommaso Di Rocco; Jean Duprat; Wataru Fujiya; Ryota Fukai; Ikshu Gautam; Makiko K. Haba; Minako Hashiguchi; Yuki Hibiya; Hiroshi Hidaka; Hisashi Homma; Peter Hoppe; Gary R. Huss; Kiyohiro Ichida; Tsuyoshi Iizuka; Trevor R. Ireland; Akira Ishikawa; Motoo Ito; Shoichi Itoh; Kanami Kamide; Noriyuki Kawasaki; A. L. David Kilcoyne; Noriko T. Kita; Kouki Kitajima; Thorsten Kleine; Shintaro Komatani; Mutsumi Komatsu; Alexander N. Krot; Ming-Chang Liu; Zita Martins; Yuki Masuda; Jérémie Mathurin; Kevin D. McKeegan; Gilles Montagnac; Mayu Morita; Smail Mostefaoui; Kazuko Motomura; Frédéric Moynier; Izumi Nakai; Ann N. Nguyen; Takuji Ohigashi; Taiga Okumura; Morihiko Onose; Andreas Pack; Changkun Park; Laurette Piani; Liping Qin; Eric Quirico; Laurent Remusat; Sara S. Russell; Naoya Sakamoto; Scott A. Sandford; Maria Schönbächler; Miho Shigenaka; Hiroki Suga; Lauren Tafla; Yoshio Takahashi; Yasuo Takeichi; Yusuke Tamenori; Haolan Tang; Kentaro Terada; Yasuko Terada; Tomohiro Usui; Maximilien Verdier-Paoletti; Sohei Wada; Meenakshi Wadhwa; Daisuke Wakabayashi; Richard J. Walker; Katsuyuki Yamashita; Shohei Yamashita; Qing-Zhu Yin; Tetsuya Yokoyama; Shigekazu Yoneda; Edward D. Young; Hiroharu Yui; Ai-Cheng Zhang; Masanao Abe; Akiko Miyazaki; Aiko Nakato; Satoru Nakazawa; Masahiro Nishimura; Tatsuaki Okada; Takanao Saiki; Satoshi Tanaka; Fuyuto Terui; Yuichi Tsuda; Sei-ichiro Watanabe; Toru Yada; Kasumi Yogata; Makoto Yoshikawa; Tomoki Nakamura; Hiroshi Naraoka; Takaaki Noguchi; Ryuji Okazaki; Kanako Sakamoto; Shogo Tachibana; Hisayoshi Yurimoto
  The Astrophysical Journal Letters, 935, 1, L3, L3, American Astronomical Society, 01 Aug. 2022
  Scientific journal, Abstract
  
  We have conducted a NanoSIMS-based search for presolar material in samples recently returned from C-type asteroid Ryugu as part of JAXA's Hayabusa2 mission. We report the detection of all major presolar grain types with O- and C-anomalous isotopic compositions typically identified in carbonaceous chondrite meteorites: 1 silicate, 1 oxide, 1 O-anomalous supernova grain of ambiguous phase, 38 SiC, and 16 carbonaceous grains. At least two of the carbonaceous grains are presolar graphites, whereas several grains with moderate C isotopic anomalies are probably organics. The presolar silicate was located in a clast with a less altered lithology than the typical extensively aqueously altered Ryugu matrix. The matrix-normalized presolar grain abundances in Ryugu are ${4.8}_{-2.6}^{+4.7}$ ppm for O-anomalous grains, ${25}_{-5}^{+6}$ ppm for SiC grains, and ${11}_{-3}^{+5}$ ppm for carbonaceous grains. Ryugu is isotopically and petrologically similar to carbonaceous Ivuna-type (CI) chondrites. To compare the in situ presolar grain abundances of Ryugu with CI chondrites, we also mapped Ivuna and Orgueil samples and found a total of 15 SiC grains and 6 carbonaceous grains. No O-anomalous grains were detected. The matrix-normalized presolar grain abundances in the CI chondrites are similar to those in Ryugu: ${23}_{-6}^{+7}$ ppm SiC and ${9.0}_{-3.6}^{+5.4}$ ppm carbonaceous grains. Thus, our results provide further evidence in support of the Ryugu–CI connection. They also reveal intriguing hints of small-scale heterogeneities in the Ryugu samples, such as locally distinct degrees of alteration that allowed the preservation of delicate presolar material.
• Formation and decomposition of vacancy-rich clinopyroxene in a shocked eucrite: New insights for multiple impact events
  Ai-Cheng Zhang; Jie-Ya Li; Jia-Ni Chen; Yuan-Yun Wen; Yan-Jun Guo; Yang Li; Naoya Sakamoto; Hisayoshi Yurimoto
  GEOCHIMICA ET COSMOCHIMICA ACTA, 329, 38, 50, Jul. 2022
  English, Scientific journal
• Samples returned from the asteroid Ryugu are similar to Ivuna-type carbonaceous meteorites
  Tetsuya Yokoyama; Kazuhide Nagashima; Izumi Nakai; Edward D. Young; Yoshinari Abe; Jérôme Aléon; Conel M. O’D. Alexander; Sachiko Amari; Yuri Amelin; Ken-ichi Bajo; Martin Bizzarro; Audrey Bouvier; Richard W. Carlson; Marc Chaussidon; Byeon-Gak Choi; Nicolas Dauphas; Andrew M. Davis; Tommaso Di Rocco; Wataru Fujiya; Ryota Fukai; Ikshu Gautam; Makiko K. Haba; Yuki Hibiya; Hiroshi Hidaka; Hisashi Homma; Peter Hoppe; Gary R. Huss; Kiyohiro Ichida; Tsuyoshi Iizuka; Trevor R. Ireland; Akira Ishikawa; Motoo Ito; Shoichi Itoh; Noriyuki Kawasaki; Noriko T. Kita; Kouki Kitajima; Thorsten Kleine; Shintaro Komatani; Alexander N. Krot; Ming-Chang Liu; Yuki Masuda; Kevin D. McKeegan; Mayu Morita; Kazuko Motomura; Frédéric Moynier; Ann Nguyen; Larry Nittler; Morihiko Onose; Andreas Pack; Changkun Park; Laurette Piani; Liping Qin; Sara S. Russell; Naoya Sakamoto; Maria Schönbächler; Lauren Tafla; Haolan Tang; Kentaro Terada; Yasuko Terada; Tomohiro Usui; Sohei Wada; Meenakshi Wadhwa; Richard J. Walker; Katsuyuki Yamashita; Qing-Zhu Yin; Shigekazu Yoneda; Hiroharu Yui; Ai-Cheng Zhang; Harold C. Connolly; Dante S. Lauretta; Tomoki Nakamura; Hiroshi Naraoka; Takaaki Noguchi; Ryuji Okazaki; Kanako Sakamoto; Hikaru Yabuta; Masanao Abe; Masahiko Arakawa; Atsushi Fujii; Masahiko Hayakawa; Naoyuki Hirata; Naru Hirata; Rie Honda; Chikatoshi Honda; Satoshi Hosoda; Yu-ichi Iijima; Hitoshi Ikeda; Masateru Ishiguro; Yoshiaki Ishihara; Takahiro Iwata; Kosuke Kawahara; Shota Kikuchi; Kohei Kitazato; Koji Matsumoto; Moe Matsuoka; Tatsuhiro Michikami; Yuya Mimasu; Akira Miura; Tomokatsu Morota; Satoru Nakazawa; Noriyuki Namiki; Hirotomo Noda; Rina Noguchi; Naoko Ogawa; Kazunori Ogawa; Tatsuaki Okada; Chisato Okamoto; Go Ono; Masanobu Ozaki; Takanao Saiki; Naoya Sakatani; Hirotaka Sawada; Hiroki Senshu; Yuri Shimaki; Kei Shirai; Seiji Sugita; Yuto Takei; Hiroshi Takeuchi; Satoshi Tanaka; Eri Tatsumi; Fuyuto Terui; Yuichi Tsuda; Ryudo Tsukizaki; Koji Wada; Sei-ichiro Watanabe; Manabu Yamada; Tetsuya Yamada; Yukio Yamamoto; Hajime Yano; Yasuhiro Yokota; Keisuke Yoshihara; Makoto Yoshikawa; Kent Yoshikawa; Shizuho Furuya; Kentaro Hatakeda; Tasuku Hayashi; Yuya Hitomi; Kazuya Kumagai; Akiko Miyazaki; Aiko Nakato; Masahiro Nishimura; Hiromichi Soejima; Ayako Suzuki; Toru Yada; Daiki Yamamoto; Kasumi Yogata; Miwa Yoshitake; Shogo Tachibana; Hisayoshi Yurimoto
  Science, 379, 6634, eabn7850, American Association for the Advancement of Science (AAAS), 09 Jun. 2022, [Peer-reviewed], [International Magazine]
  English, Scientific journal, Carbonaceous meteorites are thought to be fragments of C-type (carbonaceous) asteroids. Samples of the C-type asteroid (162173) Ryugu were retrieved by the Hayabusa2 spacecraft. We measure the mineralogy, bulk chemical and isotopic compositions of Ryugu samples. They are mainly composed of materials similar to carbonaceous chondrite meteorites, particularly the CI (Ivuna-type) group. The samples consist predominantly of minerals formed in aqueous fluid on a parent planetesimal. The primary minerals were altered by fluids at a temperature of 37 ± 10°C, (Stat.) (Syst.) million years after formation of the first solids in the Solar System. After aqueous alteration, the Ryugu samples were likely never heated above ~100°C. The samples have a chemical composition that more closely resembles the Sun’s photosphere than other natural samples do.
• Allocation of Carbon from an Arbuscular Mycorrhizal Fungus, Gigaspora margarita, to Its Gram-Negative and Positive Endobacteria Revealed by High-Resolution Secondary Ion Mass Spectrometry
  Yukari Kuga; Ting-Di Wu; Naoya Sakamoto; Chie Katsuyama; Hisayoshi Yurimoto
  MICROORGANISMS, 9, 12, Dec. 2021
  English, Scientific journal
• Inter- and intra-crystal quartz δ18O homogeneity at Okataina volcano, Aotearoa New Zealand: Implications for rhyolite genesis
  May Sas; Phil Shane; Noriyuki Kawasaki; Naoya Sakamoto; Georg F. Zellmer; Hisayoshi Yurimoto
  Journal of Volcanology and Geothermal Research, 421, 107430, 107430, Nov. 2021, [Peer-reviewed]
  English, Scientific journal
• Shallow magmatic processes revealed by cryptic microantecrysts: a case study from the Taupo Volcanic Zone
  Charline Lormand; Georg Florian Zellmer; Naoya Sakamoto; Teresa Ubide; Geoff Kilgour; Hisayoshi Yurimoto; Alan Palmer; Karoly Németh; Yoshiyuki Iizuka; Anja Moebis
  Contributions to Mineralogy and Petrology, 176, 11, Springer Science and Business Media LLC, Nov. 2021
  Scientific journal, Arc magmas typically contain phenocrysts with complex zoning and diverse growth histories. Microlites highlight the same level of intracrystalline variations but require nanoscale resolution which is globally less available. The southern Taupo Volcanic Zone (TVZ), New Zealand, has produced a wide range of explosive eruptions yielding glassy microlite-bearing tephras. Major oxide analyses and textural information reveal that microlite rims are commonly out of equilibrium with the surrounding glass. We mapped microlites and microcrysts at submicron resolution for major and trace element distributions and observed three plagioclase textural patterns: (1) resorption and overgrowth, (2) oscillatory zoning, and (3) normal (sharp) zoning. Pyroxene textures are diverse: (1) resorption and overgrowth, (2) calcium-rich bands, (3) hollow textures, (4) oscillatory zoning, (5) sector zoning, (6) normal zoning and (7) reverse zoning. Microlite chemistry and textures inform processes operating during pre-eruptive magma ascent. They indicate a plumbing system periodically intruded by short-lived sub-aphyric dykes that entrain microantecrysts grown under diverse physico-chemical conditions and stored in rapidly cooled, previously intruded dykes. Changes in temperature gradients between the intrusion and the host rock throughout ascent and repeated magma injections lead to fluctuations in cooling rates and generate local heterogeneities illustrated by the microlite textures and rim compositions. Late-stage degassing occurs at water saturation, forming thin calcic microcryst rims through local partitioning effects. This detailed investigation of textures cryptic to conventional imaging shows that a significant proportion of the micrometre-sized crystal cargo of the TVZ is of antecrystic origin and may not be attributed to late-stage nucleation and growth at the onset of volcanic eruptions, as typically presumed.
• Oxygen and Al-Mg isotopic constraints on cooling rate and age of partial melting of an Allende Type B CAI, Golfball
  Noriyuki Kawasaki; Shoichi Itoh; Naoya Sakamoto; Steven B. Simon; Daiki Yamamoto; Hisayoshi Yurimoto
  METEORITICS & PLANETARY SCIENCE, 56, 6, 1224, 1239, Jun. 2021
  English, Scientific journal
• Hydrogen diffusion mechanism in the mantle deduced from H-D interdiffusion in wadsleyite
  Wei Sun; Takashi Yoshino; Naoya Sakamoto; Hisayoshi Yurimoto
  Earth and Planetary Science Letters, 561, 116815, 116815, Elsevier BV, May 2021
  Scientific journal
• Experimental evidence for hydrogen incorporation into Earth's core
  Shoh Tagawa; Naoya Sakamoto; Kei Hirose; Shunpei Yokoo; John Hernlund; Yasuo Ohishi; Hisayoshi Yurimoto
  NATURE COMMUNICATIONS, 12, 1, May 2021
  English, Scientific journal
• Widespread Tissintite in Strongly Shock-Lithified Lunar Regolith Breccias
  Ai-Cheng Zhang; Qin-Ting Jiang; Naotaka Tomioka; Yan-Jun Guo; Jia-Ni Chen; Yang Li; Naoya Sakamoto; Hisayoshi Yurimoto
  GEOPHYSICAL RESEARCH LETTERS, 48, 5, Mar. 2021
  English, Scientific journal
• Isotope Microscopic Observation of Osteogenesis Process Forming Robust Bonding of Double Network Hydrogel to Bone
  Takayuki Nonoyama; Lei Wang; Masumi Tsuda; Yuki Suzuki; Ryuji Kiyama; Kazunori Yasuda; Shinya Tanaka; Kousuke Nagata; Ryosuke Fujita; Naoya Sakamoto; Noriyuki Kawasaki; Hisayoshi Yurimoto; Jian Ping Gong
  ADVANCED HEALTHCARE MATERIALS, 10, 3, Feb. 2021
  English, Scientific journal
• MushPEC: Correcting Post-entrapment Processes Affecting Melt Inclusions Hosted in Olivine Antecrysts
  Raimundo Brahm; Georg F. Zellmer; Takeshi Kuritani; Daniel Coulthard; Mitsuhiro Nakagawa; Naoya Sakamoto; Hisayoshi Yurimoto; Eiichi Sato
  FRONTIERS IN EARTH SCIENCE, 8, Jan. 2021
  English, Scientific journal
• An effect of variations in relative sensitivity factors on Al-Mg systematics of Ca-Al-rich inclusions in meteorites with secondary ion mass spectrometry
  Noriyuki Kawasaki; Changkun Park; Shigeyuki Wakaki; Hwayoung Kim; Sunyoung Park; Toshihiro Yoshimura; Kazuya Nagaishi; Hyun Na Kim; Naoya Sakamoto; Hisayoshi Yurimoto
  GEOCHEMICAL JOURNAL, 55, 4, 283, 287, 2021
  English, Scientific journal
• A new occurrence of corundum in eucrite and its significance
  Jie-Ya Li; Ai-Cheng Zhang; Naoya Sakamoto; Hisayoshi Yurimoto; Li-Xin Gu
  AMERICAN MINERALOGIST, 105, 11, 1656, 1661, Nov. 2020
  English, Scientific journal
• Slow ascent of unusually hot intermediate magmas triggering strombolian to sub-plinian eruptions
  C. Lormand; G. F. Zellmer; G. N. Kilgour; K. Németh; A. S. Palmer; N. Sakamoto; H. Yurimoto; T. Kuritani; Y. Iizuka; A. Moebis
  Journal of Petrology, 61, 10, 01 Oct. 2020
  Scientific journal
• Mineralogical and oxygen isotopic study of a new ultrarefractory inclusion in the Northwest Africa 3118 CV3 chondrite
  Yong Xiong; Ai-Cheng Zhang; Noriyuki Kawasaki; Chi Ma; Naoya Sakamoto; Jia-Ni Chen; Li-Xin Gu; Hisayoshi Yurimoto
  METEORITICS & PLANETARY SCIENCE, 55, 10, 2184, 2205, Oct. 2020
  English, Scientific journal
• The Cr-Zr-Ca armalcolite in lunar rocks is loveringite: Constraints from electron backscatter diffraction measurements
  Ai-Cheng Zhang; Run-Lian Pang; Naoya Sakamoto; Hisayoshi Yurimoto
  AMERICAN MINERALOGIST, 105, 7, 1021, 1029, Jul. 2020, [Peer-reviewed]
  English, Scientific journal
• Variations in initial ²⁶Al/²⁷Al ratios among fine-grained Ca-Al-rich inclusions from reduced CV chondrites
  Noriyuki Kawasaki; Sohei Wada; Changkun Park; Naoya Sakamoto; Hisayoshi Yurimoto
  Geochimica et Cosmochimica Acta, 279, 1, 15, 15 Jun. 2020, [Peer-reviewed]
  Scientific journal
• Unique angrite-like fragments in a CH3 chondrite reveal a new basaltic planetesimal
  Ai-Cheng Zhang; Noriyuki Kawasaki; Minami Kuroda; Yang Li; Hua-Pei Wang; Xue-Ning Bai; Naoya Sakamoto; Qing-Zhu Yin; Hisayoshi Yurimoto
  GEOCHIMICA ET COSMOCHIMICA ACTA, 275, 48, 63, Apr. 2020, [Peer-reviewed]
  English, Scientific journal
• Evidence of metasomatism in the interior of Vesta
  Ai-Cheng Zhang; Noriyuki Kawasaki; Huiming Bao; Jia Liu; Liping Qin; Minami Kuroda; Jian-Feng Gao; Li-Hui Chen; Ye He; Naoya Sakamoto; Hisayoshi Yurimoto
  NATURE COMMUNICATIONS, 11, 1, Mar. 2020, [Peer-reviewed]
  English, Scientific journal
• Heating duration of igneous rim formation on a chondrule in the Northwest Africa 3118 CV3oxA carbonaceous chondrite inferred from micro-scale migration of the oxygen isotopes
  Nozomi Matsuda; Naoya Sakamoto; Shogo Tachibana; Hisayoshi Yurimoto
  Chemie der Erde, 79, 4, Dec. 2019, [Peer-reviewed]
  Scientific journal
• Organogermanium suppresses cell death due to oxidative stress in normal human dermal fibroblasts
  Takeda Tomoya; Doiyama Sota; Azumi Junya; Shimada Yasuhiro; Tokuji Yoshihiko; Yamaguchi Hiroaki; Nagata Kosuke; Sakamoto Naoya; Aso Hisashi; Nakamura Takashi
  SCIENTIFIC REPORTS, 9, 1, 13637, 13637, 20 Sep. 2019, [Peer-reviewed], [International Magazine]
  English, Scientific journal
• Combined U-corrected Pb-Pb dating and ²⁶Al-²⁶Mg systematics of individual chondrules – Evidence for a reduced initial abundance of ²⁶Al amongst inner Solar System chondrules
  Jean Bollard; Noriyuki Kawasaki; N. Sakamoto; Mia Olsen; Shoichi Itoh; Kirsten Larsen; Daniel Wielandt; Martin Schiller; James N. Connelly; Hisayoshi Yurimoto; Martin Bizzarro
  Geochimica et Cosmochimica Acta, 260, 62, 83, 01 Sep. 2019, [Peer-reviewed]
  Scientific journal
• UNIQUE ANGRITE-LIKE FRAGMENTS IN A CH3 CHONDRITE REVEAL A NEW BASALTIC PLANETESIMAL
  Zhang, A. C.; Kawasaki, N.; Kuroda, M.; Li, Y.; Wang, H.; Bai, X. N.; Sakamoto, N.; Yin, Q. Z.; Yurimoto, H.
  METEORITICS & PLANETARY SCIENCE, 54, Aug. 2019, [Peer-reviewed]
  English
• DEVELOPMENT OF SAMPLE PREPARATION TECHNIQUE FOR ISOTOPE ANALYSIS OF FLUID INCLUSIONS BY SIMS
  Isono Y; Sakamoto N; Ishibashi A; Song J; Yurimoto H
  METEORITICS & PLANETARY SCIENCE, 54, Aug. 2019, [Peer-reviewed]
• CONSTRAINTS ON THE COOLING RATE FROM O-16-RICH PEROVSKITE IN A COMPACT TYPE A CAI FROM ALLENDE
  Park C; Sakamoto N; Wakaki S; Kobayashi S; Kawasaki N; Yurimoto H
  METEORITICS & PLANETARY SCIENCE, 54, Aug. 2019, [Peer-reviewed]
  English
• EXTREME O-16-RICH REFRACTORY INCLUSIONS IN THE ISHEYEVO CHONDRITE.
  Sakamoto N; Kawasaki N
  METEORITICS & PLANETARY SCIENCE, 54, Aug. 2019, [Peer-reviewed]
  English
• HEATING HISTORY OF IGNEOUS RIM FORMATION DEDUCED FROM MICRO-SCALE MIGRATION OF OXYGEN ISOTOPES
  Matsuda N; Sakamoto N; Tachibana S; Yurimoto H
  METEORITICS & PLANETARY SCIENCE, 54, Aug. 2019, [Peer-reviewed]
• VARIATIONS IN INITIAL (26)AL ABUNDANCES AMONG FINE-GRAINED CA-AL-RICH INCLUSIONS IN THE REDUCED CV CHONDRITES.
  Kawasaki N; Park C; Sakamoto N; Yurimoto H
  METEORITICS & PLANETARY SCIENCE, 54, Aug. 2019, [Peer-reviewed]
  English
• H-D Interdiffusion in Single-Crystal Olivine: Implications for Electrical Conductivity in the Upper Mantle
  Wei Sun; Takashi Yoshino; Minami Kuroda; Naoya Sakamoto; Hisayoshi Yurimoto
  Journal of Geophysical Research: Solid Earth, 124, 6, 5696, 5707, Jun. 2019, [Peer-reviewed]
  Scientific journal
• The ion microprobe as a tool for obtaining strontium isotopes in magmatic plagioclase: A case study at Okataina Volcanic Centre, New Zealand
  May Sas; Noriyuki Kawasaki; Naoya Sakamoto; Phil Shane; Georg F. Zellmer; Adam J.R. Kent; Hisayoshi Yurimoto
  Chemical Geology, 513, 153, 166, 20 May 2019, [Peer-reviewed]
  Scientific journal
• Nebular history of an ultrarefractory phase bearing CAI from a reduced type CV chondrite
  Takashi Yoshizaki; Daisuke Nakashima; Tomoki Nakamura; Changkun Park; Naoya Sakamoto; Hatsumi Ishida; Shoichi Itoh
  GEOCHIMICA ET COSMOCHIMICA ACTA, 252, 39, 60, May 2019, [Peer-reviewed]
  English, Scientific journal
• Variations in initial ²⁶ Al/ ²⁷ Al ratios among fluffy Type A Ca–Al-rich inclusions from reduced CV chondrites
  Noriyuki Kawasaki; Changkun Park; Naoya Sakamoto; Sun Young Park; Hyun Na Kim; Minami Kuroda; Hisayoshi Yurimoto
  Earth and Planetary Science Letters, 511, 25, 35, Apr. 2019, [Peer-reviewed]
  Scientific journal
• Fast diffusion path for water in silica glass
  Minami Kuroda; Shogo Tachibana; Naoya Sakamoto; Hisayoshi Yurimoto
  American Mineralogist, 104, 3, 385, 390, 01 Mar. 2019, [Peer-reviewed]
  Scientific journal
• An example of high-T, high-symmetry crystallization: Spherical (Mg, Fe)-oxides formed by particle attachment in the shocked martian meteorite Northwest Africa 7755
  Zhang Ai-Cheng; Wang Shu-Zhou; Tomioka Naotaka; Lu Xian-Cai; Ding Zhi-Yuan; Ma Chi; Wang Peng; Chen Jia-Ni; Xu Sheng; Gu Li-Xin; Bai Yuan-Qiang; Li Yang; Sakamoto Naoya; Wang Ru-Cheng
  AMERICAN MINERALOGIST, 104, 1, 150, 157, Jan. 2019, [Peer-reviewed]
• Weka trainable segmentation plugin in ImageJ: A semi-automatic tool applied to crystal size distributions of microlites in volcanic rocks
  Charline Lormand; Georg F. Zellmer; Károly Németh; Geoff Kilgour; Stuart Mead; Alan S. Palmer; Naoya Sakamoto; Hisayoshi Yurimoto; Anja Moebis
  Microscopy and Microanalysis, 24, 6, 667, 675, 01 Dec. 2018, [Peer-reviewed]
  Scientific journal
• Oxygen Isotopic Exchange between Amorphous Silicate and Water Vapor and Its Implications for Oxygen Isotopic Evolution in the Early Solar System
  Yamamoto Daiki; Kuroda Minami; Tachibana Shogo; Sakamoto Naoya; Yurimoto Hisayoshi
  ASTROPHYSICAL JOURNAL, 865, 2, 01 Oct. 2018, [Peer-reviewed]
  English, Scientific journal
• Stability of Al-bearing superhydrous phase B at the mantle transition zone and the uppermost lower mantle
  Kakizawa Sho; Inoue Toru; Nakano Hideto; Kuroda Minami; Sakamoto Naoya; Yurimoto Hisayoshi
  AMERICAN MINERALOGIST, 103, 8, 1221, 1227, Aug. 2018, [Peer-reviewed]
  English, Scientific journal
• CHONDRULE RIM INCLUDING O-16-ENRICHED OLIVINE IN CARBONACEOUS CHONDRITE NORTHWEST AFRICA 3118
  Matsuda N; Sakamoto N; Tachibana S; Yurimoto H
  METEORITICS & PLANETARY SCIENCE, 53, 6179, Aug. 2018, [Peer-reviewed]
• A SHORT TIMESCALE FOR CAI RIM FORMATION.
  T. Yoshizaki; T. Nakamura; D. Nakashima; N. Sakamoto; H. Ishida; S. Itoh
  METEORITICS & PLANETARY SCIENCE, 53, 6012, 6012, Aug. 2018, [Peer-reviewed]
  English
• Water diffusion in silica glass through pathways formed by hydroxyls
  Minami Kuroda; Shogo Tachibana; Naoya Sakamoto; Satoshi Okumura; Michihiko Nakamura; Hisayoshi Yurimoto
  American Mineralogist, 103, 3, 412, 417, 26 Mar. 2018, [Peer-reviewed]
  English, Scientific journal
• Supercritical fluid in the mantle transition zone deduced from H–D interdiffusion of wadsleyite
  Wei Sun; Takashi Yoshino; Naoya Sakamoto; Hisayoshi Yurimoto
  Earth and Planetary Science Letters, 484, 309, 317, 15 Feb. 2018, [Peer-reviewed]
  English, Scientific journal
• Negative activation volume of oxygen self-diffusion in forsterite
  Hongzhan Fei; Michael Wiedenbeck; Naoya Sakamoto; Hisayoshi Yurimoto; Takashi Yoshino; Daisuke Yamazaki; Tomoo Katsura
  Physics of the Earth and Planetary Interiors, 275, 1, 8, 01 Feb. 2018, [Peer-reviewed]
  English, Scientific journal
• Crystal growth and disequilibrium distribution of oxygen isotopes in an igneous Ca-Al-rich inclusion from the Allende carbonaceous chondrite
  Noriyuki Kawasaki; Steven B. Simon; Lawrence Grossman; Naoya Sakamoto; Hisayoshi Yurimoto
  Geochimica et Cosmochimica Acta, 221, 318, 341, 15 Jan. 2018, [Peer-reviewed]
  English, Scientific journal
• Origin and implications of troilite-orthopyroxene intergrowths in the brecciated diogenite Northwest Africa 7183
  Ai-Cheng Zhang; Yi-Fan Bu; Run-Lian Pang; Naoya Sakamoto; Hisayoshi Yurimoto; Li-Hui Chen; Jian-Feng Gao; De-Hong Du; Xiao-Lei Wang; Ru-Cheng Wang
  GEOCHIMICA ET COSMOCHIMICA ACTA, 220, 125, 145, Jan. 2018, [Peer-reviewed]
  English, Scientific journal
• On progress and rate of the peritectic reaction Fo + SiO2 -> En in natural andesitic arc magmas (vol 185, pg 383, 2016)
  Georg F. Zellmer; Naoya Sakamoto; Nozomi Matsuda; Yoshiyuki Iizuka; Anja Moebis; Hisayoshi Yurimoto
  GEOCHIMICA ET COSMOCHIMICA ACTA, 220, 552, 553, Jan. 2018, [Peer-reviewed]
  English
• Mg lattice diffusion in iron-free olivine and implications to conductivity anomaly in the oceanic asthenosphere
  Fei, H.; Koizumi, S.; Sakamoto, N.; Hashiguchi, M.; Yurimoto, H.; Marquardt, K.; Miyajima, N.; Katsura, T.
  Earth and Planetary Science Letters, 484, 204, 212, 2018, [Peer-reviewed]
  Scientific journal
• Boron-doped diamond as a new heating element for internal-resistive heated diamond-anvil cell
  Haruka Ozawa; Shigehiko Tateno; Longjian Xie; Yoichi Nakajima; Naoya Sakamoto; Saori I. Kawaguchi; Akira Yoneda; Naohisa Hirao
  HIGH PRESSURE RESEARCH, 38, 2, 120, 135, 2018, [Peer-reviewed]
  English, Scientific journal
• Pressure, temperature, water content, and oxygen fugacity dependence of the Mg grain-boundary diffusion coefficient in forsterite
  Fei, H.; Koizumi, S.; Sakamoto, N.; Hashiguchi, M.; Yurimoto, H.; Marquardt, K.; Miyajima, N.; Katsura, T.
  American Mineralogist, 103, 9, 1354, 1361, 2018, [Peer-reviewed]
  Scientific journal
• Formation of an ultracarbonaceous Antarctic micrometeorite through minimal aqueous alteration in a small porous icy body
  Hikaru Yabuta; Takaaki Noguchi; Shoichi Itoh; Tomoki Nakamura; Akira Miyake; Shinichi Tsujimoto; Noriaki Ohashi; Naoya Sakamoto; Minako Hashiguchi; Ken-ichi Abe; Aya Okubo; A. L. David Kilcoyne; Shogo Tachibana; Ryuji Okazaki; Kentaro Terada; Mitsuru Ebihara; Hiroko Nagahara
  GEOCHIMICA ET COSMOCHIMICA ACTA, 214, 172, 190, Oct. 2017, [Peer-reviewed]
  English, Scientific journal
• ORIGIN OF SPINEL FRAMBOIDS IN CALCIUM-ALUMINUM-RICH INCLUSIONS
  T. Yoshizaki; D. Nakashima; T. Nakamura; H. Ishida; N. Sakamoto
  METEORITICS & PLANETARY SCIENCE, 52, A400, A400, Aug. 2017, [Peer-reviewed]
  English
• Variation of mineralogy and organic material during the early stages of aqueous activity recorded in Antarctic micrometeorites
  T. Noguchi; H. Yabuta; S. Itoh; N. Sakamoto; T. Mitsunari; A. Okubo; R. Okazaki; T. Nakamura; S. Tachibana; K. Terada; M. Ebihara; N. Imae; M. Kimura; H. Nagahara
  GEOCHIMICA ET COSMOCHIMICA ACTA, 208, 1, 119, 144, Jul. 2017, [Peer-reviewed]
  English, Scientific journal
• Chronological study of oxygen isotope composition for the solar protoplanetary disk recorded in a fluffy Type A CAI from Vigarano
  Kawasaki Noriyuki; Itoh Shoichi; Sakamoto Naoya; Yurimoto Hisayoshi
  Geochimica et cosmochimica acta, 201, 201, 83, 102, 15 Mar. 2017, [Peer-reviewed]
  English
• Silicon and oxygen self-diffusion in stishovite: Implications for stability of SiO2-rich seismic reflectors in the mid-mantle
  Fang Xu; Daisuke Yamazaki; Naoya Sakamoto; Wei Sun; Hongzhan Fei; Hisayoshi Yurimoto
  EARTH AND PLANETARY SCIENCE LETTERS, 459, 332, 339, Feb. 2017, [Peer-reviewed]
  English, Scientific journal
• Evidence for the solar wind in lunar magmas: A study of slowly cooled samples of the Apollo 12 olivine basalt suite
  Jack A. Singer; James P. Greenwood; Shoichi Itoh; Naoya Sakamoto; Hisayoshi Yurimoto
  GEOCHEMICAL JOURNAL, 51, 1, 95, 104, 2017, [Peer-reviewed]
  English, Scientific journal
• Occurrences, abundances, and compositional variations of cosmic symplectites in the Acfer 094 ungrouped carbonaceous chondrite
  Kenichi Abe; Naoya Sakamoto; Alexander N. Krot; Hisayoshi Yurimoto
  GEOCHEMICAL JOURNAL, 51, 1, 3, 15, 2017, [Peer-reviewed]
  English, Scientific journal
• The lunar magma ocean volatile signature recorded in chlorine-rich glasses in KREEP basalts 15382 and 15386
  James P. Greenwood; Naoya Sakamoto; Shoichi Itoh; Paul H. Warren; Jack A. Singer; Kaori Yanai; Hisayoshi Yurimoto
  GEOCHEMICAL JOURNAL, 51, 1, 105, 114, 2017, [Peer-reviewed]
  English, Scientific journal
• Young asteroidal fluid activity revealed by absolute age from apatite in carbonaceous chondrite
  Ai-Cheng Zhang; Qiu-Li Li; Hisayoshi Yurimoto; Naoya Sakamoto; Xian-Hua Li; Sen Hu; Yang-Ting Lin; Ru-Cheng Wang
  NATURE COMMUNICATIONS, 7, 12844, 12844, Sep. 2016, [Peer-reviewed], [International Magazine]
  English, Scientific journal
• Inferring the Effects of Compositional Boundary Layers on Crystal Nucleation, Growth Textures, and Mineral Chemistry in Natural Volcanic Tephras through Submicron-Resolution Imaging
  Georg F. Zellmer; Naoya Sakamoto; Shyh-Lung Hwang; Nozomi Matsuda; Yoshiyuki Iizuka; Anja Moebis; Hisayoshi Yurimoto
  FRONTIERS IN EARTH SCIENCE, 4, Sep. 2016, [Peer-reviewed]
  English, Scientific journal
• On progress and rate of the peritectic reaction Fo + SiO2 -> En in natural andesitic arc magmas
  Georg F. Zellmer; Naoya Sakamoto; Nozomi Matsuda; Yoshiyuki Iizuka; Anja Moebis; Hisayoshi Yurimoto
  GEOCHIMICA ET COSMOCHIMICA ACTA, 185, 383, 393, Jul. 2016, [Peer-reviewed]
  English, Scientific journal
• Sound velocities of aluminum-bearing stishovite in the mantle transition zone
  Steeve Greaux; Yoshio Kono; Yanbin Wang; Akihiro Yamada; Chunyin Zhou; Zhicheng Jing; Toru Inoue; Yuji Higo; Tetsuo Irifune; Naoya Sakamoto; Hisayoshi Yurimoto
  GEOPHYSICAL RESEARCH LETTERS, 43, 9, 4239, 4246, May 2016, [Peer-reviewed]
  English, Scientific journal
• New constraints on upper mantle creep mechanism inferred from silicon grain-boundary diffusion rates
  Fei, H.; Koizumi, S.; Sakamoto, N.; Hashiguchi, M.; Yurimoto, H.; Marquardt, K.; Miyajima, N.; Yamazaki, D.; Katsura, T.
  Earth and Planetary Science Letters, 433, 350, 359, 2016, [Peer-reviewed]
  Scientific journal
• Mineralogical anatomy and implications of a Ti-Sc-rich ultrarefractory inclusion from Sayh al Uhaymir 290 CH3 chondrite
  Ai-Cheng Zhang; Chi Ma; Naoya Sakamoto; Ru-Cheng Wang; Wei-Biao Hsu; Hisayoshi Yurimoto
  GEOCHIMICA ET COSMOCHIMICA ACTA, 163, 27, 39, Aug. 2015, [Peer-reviewed]
  English, Scientific journal
• Hydrogen self-diffusivity in single crystal ringwoodite: Implications for water content and distribution in the mantle transition zone
  Wei Sun; Takashi Yoshino; Naoya Sakamoto; Hisayoshi Yurimoto
  GEOPHYSICAL RESEARCH LETTERS, 42, 16, 6582, 6589, Aug. 2015, [Peer-reviewed]
  English, Scientific journal
• Synthesis of large and homogeneous single crystals of water-bearing minerals by slow cooling at deep-mantle pressures
  Takuo Okuchi; Narangoo Purevjav; Naotaka Tomioka; Jung-Fu Lin; Takahiro Kuribayashi; Louise Schoneveld; Huijeong Hwang; Naoya Sakamoto; Noriyuki Kawasaki; Hisayoshi Yurimoto
  AMERICAN MINERALOGIST, 100, 7, 1483, 1492, Jul. 2015, [Peer-reviewed]
  English, Scientific journal
• Thermal and chemical evolution of the subarc mantle revealed by spinel-hosted melt inclusions in boninite from the Ogasawara (Bonin) Archipelago, Japan
  Susumu Umino; Keitaro Kitamura; Kyoko Kanayama; Akihiro Tamura; Naoya Sakamoto; Osamu Ishizuka; Shoji Arai
  GEOLOGY, 43, 2, 151, 154, Feb. 2015, [Peer-reviewed]
  English, Scientific journal
• Interaction of arc magmas with subvolcanic hydrothermal systems: Insights from compositions and metasomatic textures of olivine crystals in fresh basalts of Daisen and Mengameyama, Western Honshu, Japan
  Georg F. Zellmer; Shyh-Lung Hwang; Naoya Sakamoto; Yoshiyuki Iizuka; Sakiko Harada; Jun-Ichi Kimura; Yoshihiko Tamura; Hisayoshi Yurimoto
  Geological Society Special Publication, 410, 1, 219, 236, Geological Society of London, 2015, [Peer-reviewed]
  English, Scientific journal
• Isotope microscopy visualization of the adsorption profile of 2-methylisoborneol and geosmin in powdered activated carbon.
  Yoshihiko Matsui; Asuka Sakamoto; Soichi Nakao; Takuma Taniguchi; Taku Matsushita; Nobutaka Shirasaki; Naoya Sakamoto; Hisayoshi Yurimoto
  Environmental science & technology, 48, 18, 10897, 903, 16 Sep. 2014, [Peer-reviewed], [International Magazine]
  English, Scientific journal
• Origins of Al-rich chondrules: Clues from a compound Al-rich chondrule in the Dar al Gani 978 carbonaceous chondrite
  Ai-Cheng Zhang; Shoichi Itoh; Naoya Sakamoto; Ru-Cheng Wang; Hisayoshi Yurimoto
  GEOCHIMICA ET COSMOCHIMICA ACTA, 130, 78, 92, Apr. 2014, [Peer-reviewed]
  English, Scientific journal
• Stable isotope cellular imaging reveals that both live and degenerating fungal pelotons transfer carbon and nitrogen to orchid protocorms.
  Yukari Kuga; Naoya Sakamoto; Hisayoshi Yurimoto
  The New phytologist, 202, 2, 594, 605, Apr. 2014, [Peer-reviewed], [International Magazine]
  English, Scientific journal
• Crystal uptake into aphyric arc melts: Insights from two-pyroxene pseudo-decompression paths, plagioclase hygrometry, and measurement of hydrogen in olivines from mafic volcanics of SW Japan
  Georg F. Zellmer; Naoya Sakamoto; Yoshiyuki Iizuka; Masaya Miyoshi; Yoshihiko Tamura; Hui-Ho Hsieh; Hisayoshi Yurimoto
  Geological Society Special Publication, 385, 1, 161, 184, 2014, [Peer-reviewed]
  English, Scientific journal
• Arsenic alters uptake and distribution of sulphur in Pteris vittata.
  Toshihiro Watanabe; Ran Kouho; Tomo Katayose; Nobuyuki Kitajima; Naoya Sakamoto; Noriko Yamaguchi; Takuro Shinano; Hisayoshi Yurimoto; Mitsuru Osaki
  Plant, cell & environment, 37, 1, 45, 53, Jan. 2014, [Peer-reviewed], [International Magazine]
  English, Scientific journal
• Ion implantation and diffusion of zinc in dense SnO2 ceramics
  Minako Hashiguchi; Isao Sakaguchi; Naoya Sakamoto; Hisayoshi Yurimoto; Shunichi Hishita; Naoki Ohashi
  JOURNAL OF THE CERAMIC SOCIETY OF JAPAN, 121, 1420, 1004, 1007, Dec. 2013, [Peer-reviewed]
  English, Scientific journal
• Characterization of oxygen defect and zinc segregation in the dense tin dioxide ceramics added with zinc oxide
  Isao Sakaguchi; Naoya Sakamoto; Minako Hashiguchi; Hisayoshi Yurimoto; Shunichi Hishita; Naoki Ohashi
  JOURNAL OF THE CERAMIC SOCIETY OF JAPAN, 121, 1419, 956, 959, Nov. 2013, [Peer-reviewed]
  English, Scientific journal
• Synthesis of ¹⁸O-labeled RNA for application to kinetic studies and imaging.
  Tomohiro Hamasaki; Takahiro Matsumoto; Naoya Sakamoto; Akiko Shimahara; Shiori Kato; Ayumi Yoshitake; Ayumi Utsunomiya; Hisayoshi Yurimoto; Esteban C Gabazza; Tadaaki Ohgi
  Nucleic acids research, 41, 12, e126, Jul. 2013, [Peer-reviewed], [International Magazine]
  English, Scientific journal
• Characterization of Bone Mineralization in a Rat Model of Chronic Kidney Disease
  Hiromi Kimura-Suda; Kyosuke Kanazawa; Sachio Kobayashi; Mieko Kuwahara; Teppei Ito; Naoya Sakamoto; Makoto Kajiwara; Hideyuki Yamato; Kuniharu Ijiro; Hisayoshi Yurimoto
  JOURNAL OF BONE AND MINERAL RESEARCH, 28, Feb. 2013, [Peer-reviewed]
  English
• Studies on bone metabolism by using isotope microscopy, FTIR imaging, and micro-Raman spectroscopy
  Hiromi Kimura-Suda; Kajiwara Makoto; Sakamoto Naoya; Kobayashi Sachio; Ijiro Kuniharu; Yurimoto Hisayoshi; Yamato Hideyuki
  Journal of Oral Biosciences, 55, 2, 61, 65, Japanese Association for Oral Biology, 2013, [Peer-reviewed]
  English
• Tissue specific localization of pectin-Ca²⁺ cross-linkages and pectin methyl-esterification during fruit ripening in tomato (Solanum lycopersicum).
  Hiromi Hyodo; Azusa Terao; Jun Furukawa; Naoya Sakamoto; Hisayoshi Yurimoto; Shinobu Satoh; Hiroaki Iwai
  PloS one, 8, 11, e78949, 2013, [Peer-reviewed], [International Magazine]
  English, Scientific journal
• Needle-like grains across growth lines in the coral skeleton of Porites lobata.
  Satoko Motai; Takaya Nagai; Kohki Sowa; Tsuyoshi Watanabe; Naoya Sakamoto; Hisayoshi Yurimoto; Jun Kawano
  Journal of structural biology, 180, 3, 389, 93, Dec. 2012, [Peer-reviewed], [International Magazine]
  English, Scientific journal
• Oxygen isotopic composition of the solar nebula gas inferred from high-precision isotope imaging of melilite crystals in an Allende CAI
  Changkun Park; Shigeyuki Wakaki; Naoya Sakamoto; Sachio Kobayashi; Hisayoshi Yurimoto
  METEORITICS & PLANETARY SCIENCE, 47, 12, 2070, 2083, Dec. 2012, [Peer-reviewed]
  English, Scientific journal
• Oxygen isotopic and chemical zoning of melilite crystals in a type A Ca-Al-rich inclusion of Efremovka CV3 chondrite
  Noriyuki Kawasaki; Naoya Sakamoto; Hisayoshi Yurimoto
  METEORITICS & PLANETARY SCIENCE, 47, 12, 2084, 2093, Dec. 2012, [Peer-reviewed]
  English, Scientific journal
• Development of Highly Sensitive Ion Imager Corresponding to Real-Time Readout Having Single-Ion Detectability
  Naoya Sakamoto; Satoshi Aoyama; Shoji Kawahito; Hisayoshi Yurimoto
  JAPANESE JOURNAL OF APPLIED PHYSICS, 51, 7, 076701, Jul. 2012, [Peer-reviewed]
  English, Scientific journal
• Oxygen Isotopic Compositions of Asteroidal Materials Returned from Itokawa by the Hayabusa Mission
  Hisayoshi Yurimoto; Ken-ichi Abe; Masanao Abe; Mitsuru Ebihara; Akio Fujimura; Minako Hashiguchi; Ko Hashizume; Trevor R. Ireland; Shoichi Itoh; Juri Katayama; Chizu Kato; Junichiro Kawaguchi; Noriyuki Kawasaki; Fumio Kitajima; Sachio Kobayashi; Tatsuji Meike; Toshifumi Mukai; Keisuke Nagao; Tomoki Nakamura; Hiroshi Naraoka; Takaaki Noguchi; Ryuji Okazaki; Changkun Park; Naoya Sakamoto; Yusuke Seto; Masashi Takei; Akira Tsuchiyama; Masayuki Uesugi; Shigeyuki Wakaki; Toru Yada; Kosuke Yamamoto; Makoto Yoshikawa; Michael E. Zolensky
  SCIENCE, 333, 6046, 1116, 1119, Aug. 2011, [Peer-reviewed], [International Magazine]
  English, Scientific journal
• Hydrogen isotope ratios in lunar rocks indicate delivery of cometary water to the Moon
  James P. Greenwood; Shoichi Itoh; Naoya Sakamoto; Paul Warren; Lawrence Taylor; Hisayoshi Yurimoto
  NATURE GEOSCIENCE, 4, 2, 79, 82, Feb. 2011, [Peer-reviewed]
  English, Scientific journal
• Analysis of the noise properties of a solid-state SCAPS ion imager and development of software noise reduction
  K. Yamamoto; N. Sakamoto; H. Yurimoto
  SURFACE AND INTERFACE ANALYSIS, 42, 10-11, 1603, 1605, Oct. 2010, [Peer-reviewed]
  English, Scientific journal
• D/H of Lunar water: Implications for the origin of the Earth's water
  James P. Greenwood; Shoichi Itoh; Naoya Sakamoto; Paul H. Warren; Lawrence A. Taylor; Hisayoshi Yurimoto
  GEOCHIMICA ET COSMOCHIMICA ACTA, 74, 12, A354, A354, Jun. 2010, [Peer-reviewed]
  English
• Discovery of O-17,O-18-rich material from meteorite by direct-imaging method using stigmatic-SIMS and 2D ion detector
  Sakamoto Naoya; Itoh Shoichi; Yurimoto Hisayoshi
  APPLIED SURFACE SCIENCE, 255, 4, 1458, 1460, 15 Dec. 2008, [Peer-reviewed]
  English, Scientific journal
• Mineralogical characterization of a unique material having heavy oxygen isotope anomaly in matrix of the primitive carbonaceous chondrite Acfer 094
  Yusuke Seto; Naoya Sakamoto; Kiyoshi Fujino; Takashi Kaito; Tetsuo Oikawa; Hisayoshi Yurimoto
  GEOCHIMICA ET COSMOCHIMICA ACTA, 72, 11, 2723, 2734, Jun. 2008, [Peer-reviewed]
  English, Scientific journal
• Oxygen isotopic compositions of Allende Type CCAIs: Evidence for isotopic exchange during nebular melting and asteroidal metamorphism
  A. N. Krot; M. Chaussidon; H. Yurimoto; N. Sakamoto; K. Nagashima; I. D. Hutcheon; G. J. MacPherson
  GEOCHIMICA ET COSMOCHIMICA ACTA, 72, 10, 2534, 2555, May 2008, [Peer-reviewed]
  English, Scientific journal
• Hydrogen isotope evidence for loss of water from Mars through time
  James P. Greenwood; Shoichi Itoh; Naoya Sakamoto; Edward P. Vicenzi; Hisayoshi Yurimoto
  GEOPHYSICAL RESEARCH LETTERS, 35, 5, Mar. 2008, [Peer-reviewed]
  English, Scientific journal
• Remnants of the early solar system water enriched in heavy oxygen isotopes.
  Naoya Sakamoto; Yusuke Seto; Shoichi Itoh; Kiyoshi Kuramoto; Kiyoshi Fujino; Kazuhide Nagashima; Alexander N Krot; Hisayoshi Yurimoto
  Science (New York, N.Y.), 317, 5835, 231, 3, 13 Jul. 2007, [Peer-reviewed], [International Magazine]
  English, Scientific journal
• Highly sensitive ion imaging system using direct combination of a stacked-type solid-state imager and a microchannel plate driven by LabVIEW software
  Naoya Sakamoto; Hisayoshi Yurimoto
  SURFACE AND INTERFACE ANALYSIS, 38, 12-13, 1760, 1762, Dec. 2006, [Peer-reviewed]
  English, Scientific journal

• Al-Mg systematics of spinel-hibonite inclusions in Ryugu and Ivuna
  宮本悠史; 川崎教行; 坂本直哉; 圦本尚義, 日本地球惑星科学連合大会予稿集(Web), 2024, 2024
• Hydrogen isotopic fractionation between the SiO₂ phase and silicate melt in the lower mantle.
  仙波芽美; 栗田直季; 坂本直哉; 廣瀬敬; 圦本尚義, 日本地球惑星科学連合大会予稿集(Web), 2024, 2024
• The origin of oxygen isotopic variations for fassaite crystals in CAIs
  川崎教行; 正立大騎; 山本大貴; SIMON Steven B.; 坂本直哉; 圦本尚義, 日本地球化学会年会要旨集(Web), 70th, 2023
• Melilite crystals in a fluffy type A CAI from Vigarano show distinct formation ages.
  田邉路紗アイディーン; 川崎教行; 坂本直哉; 圦本尚義, 日本地球化学会年会要旨集(Web), 69th, 2022
• In-situ oxygen and manganese-chromium isotope studies of Ryugu: Implications to temperature and timing of aqueous activity.
  永島一秀; 川崎教行; 坂本直哉; 中村智樹; 野口高明; 岡崎隆司; 薮田ひかる; 奈良岡浩; 坂本佳奈子; 渡邊誠一郎; 津田雄一; 橘省吾; 圦本尚義, 日本地球化学会年会要旨集(Web), 69th, 2022
• The Solar System Explored by Isotope Microscope
  Naoya Sakamoto, THE HITACHI SCIENTIFIC INSTRUMENT NEWS, 64, 2, 1, 7, Jun. 2021, [Lead author, Corresponding author]
• Oxygen and Al-Mg isotopic constraints on the cooling rate, age, and precursor of partial melting of an Allende Type B CAI, Golfball
  川崎教行; 伊藤正一; 坂本直哉; SIMON Steven B.; 山本大貴; 圦本尚義, 日本地球惑星科学連合大会予稿集(Web), 2021, 2021
• Variations in initial 26Al/27Al ratios among condensate CAIs from CV chondrites
  川崎教行; 坂本直哉; 圦本尚義, 日本地球惑星科学連合大会予稿集(Web), 2021, 2021
• Effect of Al on high pressure hydrous minerals stable under mantle transition zone and lower mantle conditions
  太田明緒; 井上徹; 野田昌道; 柿澤翔; 川添貴章; 佐藤友子; 新名亨; 入舩徹男; 坂本直哉; 圦本尚義, 日本鉱物科学会年会講演要旨(Web), 2021, 2021
• Al-Mg systematics for partial melting of an Allende type B CAI, Golfball
  川崎教行; 伊藤正一; 坂本直哉; SIMON Steven B.; 圦本尚義; 圦本尚義, 日本地球惑星科学連合大会予稿集(Web), 2020, 2020
• 下部マントル上部における水の最大貯蔵量:ブリッジマナイトの最大含水量
  柿澤翔; 柿澤翔; 井上徹; 井上徹; 井上徹; 阿部遼太郎; 黒田みなみ; 黒田みなみ; 坂本直哉; 圦本尚義; 圦本尚義; 圦本尚義, 日本地球化学会年会要旨集(Web), 66th, 2019
• CVコンドライト隕石の凝縮CAIの初生²⁶Al/²⁷Al比
  川崎教行; 和田壮平; PARK C.; 坂本直哉; 圦本尚義; 圦本尚義, 日本地球化学会年会要旨集(Web), 66th, 2019
• Reduced CVコンドライトに含まれる細粒CAIの初生²⁶Al/²⁷Al比の分布
  川崎教行; PARK Changkun; 坂本直哉; 圦本尚義; 圦本尚義, 日本地球惑星科学連合大会予稿集(Web), 2019, 2019
• 流体包有物の同位体分析のための凍結SIMS法の開発
  磯野雄生; 坂本直哉; 圦本尚義, 日本地球惑星科学連合大会予稿集(Web), 2019, 2019
• (Advanced)無染色イメージング 26.同位体顕微鏡―宇宙から生命までを覗く窓
  坂本直哉; 阿部光太郎; 圦本尚義, 実験医学, 36, 20, 3426‐3427, 15 Dec. 2018
  Japanese
• ソフトレーザーアブレーション法による物質選択的元素分析法の開発と金属包有物分析への応用
  槇納好岐; 坂本直哉; 平田岳史, 日本地球化学会年会要旨集(Web), 65th, 2018
• Acfer094隕石中の難揮発性親鉄元素に乏しいメタル
  坂本直哉; 槇納好岐; 川崎教行, 日本地球惑星科学連合大会予稿集(Web), 2018, 2018
• ダイナミックSIMSを用いた安定同位体トレーサーの微細構造局在解析:アーバスキュラー菌根における生体元素膜間輸送
  久我ゆかり; WU Ting-Di; WU Ting-Di; 永田康祐; 坂本直哉; GUERQUIN-KERN Jean-Luc; GUERQUIN-KERN Jean-Luc; 勝山千恵; 圦本尚義, 日本土壌微生物学会講演要旨集, 2018, 2018
• Bridgmaniteの含水量におけるFeの影響
  柿澤翔; 井上徹; 井上徹; 井上徹; 阿部綾太郎; 黒田みなみ; 坂本直哉; 圦本尚義; 圦本尚義; 圦本尚義, 高圧討論会講演要旨集, 59th, 2018
• 骨形成に再利用される合成HAp系インプラントの同位体顕微鏡観察
  野々山貴行; 鈴木裕貴; 木山竜二; WANG Lei; 津田真寿美; 安田和則; 田中伸哉; 永田康祐; 藤田龍介; 坂本直哉; 圦本尚義; GONG Jian Ping, 日本セラミックス協会秋季シンポジウム講演予稿集(CD-ROM), 31st, 2018
• 石英ガラスにおける水の高速拡散
  黒田みなみ; 橘省吾; 坂本直哉; 圦本尚義; 圦本尚義, 日本地球惑星科学連合大会予稿集(Web), 2018, 2018
• 太陽系星雲における高温凝縮物と火成CAIの同時期形成
  川崎教行; PARK Changkun; 坂本直哉; PARK Sun Young; KIM Hyun Na; 黒田みなみ; 圦本尚義; 圦本尚義, 日本地球惑星科学連合大会予稿集(Web), 2018, 2018
• 原始太陽系円盤での非晶質ケイ酸塩ダストと水蒸気との酸素同位体交換反応
  山本大貴; 黒田みなみ; 橘省吾; 橘省吾; 坂本直哉; 圦本尚義; 圦本尚義, 日本地球惑星科学連合大会予稿集(Web), 2018, 2018
• 含水石英ガラス中における水素同位体交換反応
  黒田みなみ; 橘省吾; 坂本直哉; 圦本尚義, 日本鉱物科学会年会講演要旨(Web), 2017, 2017
• TEM‐SIMSを用いた¹³CO₂ラベル実験によるアーバスキュラー菌根菌内生細菌への炭素輸送解析
  久我ゆかり; WU Ting‐Di; WU Ting‐Di; GUERQUIN‐KERN Jean‐Luc; GUERQUIN‐KERN Jean‐Luc; 永田康祐; 坂本直哉; 圦本尚義; 勝山千恵, 日本微生物生態学会大会(Web), 61, 0, 109, 109, 2017
  日本菌学会, Japanese
• アエンデ隕石の火成CAIにみられる鉱物の結晶成長と酸素同位体の非平衡分布との関係
  川崎教行; SIMON Steven B; GROSSMAN Lawrence; 坂本直哉; 圦本尚義; 圦本尚義, 日本地球惑星科学連合大会予稿集(Web), 2017, ROMBUNNO.PPS10‐29 (WEB ONLY), 2017
  Japanese
• EARLY STAGES OF AQUEOUS ALTERATION IN COMETARY BODIES.
  T. Noguchi; H. Yabuta; S. Itoh; N. Sakamoto; T. Mitsunari; A. Okubo; R. Okazaki; T. Nakamura; S. Tachibana; K. Terada; M. Ebihara; N. Imae; M. Kimura; H. Nagahara, METEORITICS & PLANETARY SCIENCE, 51, A489, A489, Aug. 2016
  English, Summary international conference
• 温水処理による白紋羽病菌衰退現象における土壌微生物機能解析法の構築:安定同位体イメージング法
  久我ゆかり; 山田博之; 田代智子; 勝山千恵; 中村仁; 坂本直哉; 圦本尚義, 日本土壌微生物学会講演要旨集, 2016, 9, 06 Jun. 2016
  Japanese
• ヴィガラノ隕石fluffy Type A CAIに記録された初期太陽系円盤の酸素同位体組成変化のAl‐Mg年代学
  川崎教行; 伊藤正一; 坂本直哉; 圦本尚義; 圦本尚義, 日本地球惑星科学連合大会予稿集(Web), 2016, ROMBUNNO.PPS12‐04 (WEB ONLY), 2016
  Japanese
• ケイ酸塩ガラス中の水の拡散における含水量依存性
  黒田みなみ; 橘省吾; 奥村聡; 中村美千彦; 坂本直哉; 圦本尚義, 日本鉱物科学会年会講演要旨集, 2015, 5, 18 Sep. 2015
  Japanese
• FORMATION PERIOD FOR A FLUFFY TYPE A CAI FROM VIGARANO.
  N. Kawasaki; N. Sakamoto; H. Yurimoto, METEORITICS & PLANETARY SCIENCE, 50, Aug. 2015
  English, Summary international conference
• EARLY DISK DYNAMICS INFERRED FROM ISOTOPE SYSTEMATICS OF INDIVIDUAL CHONDRULES
  J. Bollard; N. Kawasaki; N. Sakamoto; K. Larsen; D. Wielandt; M. Schiller; J. Connelly; H. Yurimoto; M. Bizzarro, METEORITICS & PLANETARY SCIENCE, 50, Aug. 2015
  English, Summary international conference
• Vigarano隕石産Type B1CAIの酸素同位体分布
  山本淳博; 川崎教行; 坂本直哉; 圦本尚義, 日本地球惑星科学連合大会予稿集(Web), 2015, ROMBUNNO.PPS22‐12 (WEB ONLY), 2015
  Japanese
• マントル遷移層におけるペリドタイトと共存する無水鉱物の水の溶解度
  YOSHINO TAKASHI; SAKURAI MOE; SAKAMOTO NAOYA; YURIMOTO HISAYOSHI, 高圧討論会講演要旨集, 55th, 6, 10 Nov. 2014
  Japanese
• SIMSを用いたラン共生組織における元素輸送のイメージング解析
  KUGA YUKARI; SAKAMOTO NAOYA; YURIMOTO HISAYOSHI, 日本土壌肥料学会講演要旨集, 60, 36, 09 Sep. 2014
  Japanese
• GEHLENITIC MANTLE FORMATION OF A COMPACT TYPE A CAI FROM ALLENDE
  C. Park; K. Nagashima; S. Wakaki; N. Sakamoto; S. Kobayashi; H. Yurimoto, METEORITICS & PLANETARY SCIENCE, 49, A315, A315, Sep. 2014
  English, Summary international conference
• 同位体顕微鏡を用いた植物組織内での元素の可視化
  OGASAWARA KIMI; SAKAMOTO NAOYA; ITO TOSHIAKI; NAITO SATOSHI; TAKANO JUMPEI; YURIMOTO HISAYOSHI, 日本顕微鏡学会関東支部講演会予稿集, 38th, 41, 08 Mar. 2014
  Japanese
• 同位体顕微鏡によるラン共生プロトコームにおける元素輸送の細胞内可視化(2013年度大会一般講演要旨)
  久我 ゆかり; 坂本 直哉; 圦本 尚義, 土と微生物, 68, 1, 36, 36, 2014
  日本土壌微生物学会, Japanese
• 同位体顕微鏡システムを用いた植物組織内での元素の直接可視化
  OGASAWARA KIMI; SAKAMOTO NAOYA; ITO TOSHIAKI; YURIMOTO HISAYOSHI; NAITO SATOSHI; TAKANO JUMPEI, 日本植物学会大会研究発表記録, 77th, 167, 20 Aug. 2013
  Japanese
• 同位体顕微鏡によるラン共生プロトコームにおける元素輸送の細胞内可視化
  KUGA YUKARI; SAKAMOTO NAOYA; YURIMOTO HISAYOSHI, 日本土壌微生物学会講演要旨集, 2013, 23, 19 Jun. 2013
  Japanese
• 同位体顕微鏡システムを用いたシロイヌナズナ組織中のホウ素の直接可視化手法の確立
  OGASAWARA KIMI; SAKAMOTO NAOYA; ITO TOSHIAKI; YURIMOTO HISAYOSHI; NAITO SATOSHI; TAKANO JUMPEI, 日本植物生理学会年会要旨集, 54th, 335, 14 Mar. 2013
  Japanese
• B3-04 Genetic conditions of boninite magmas : Variety of primary boninites deduced from melt inclusions in Cr spinel
  Kitamura Keitaro; Umino Susumu; Kanayama Kyoko; Ishizuka O.; Sakamoto N.; Yurimoto H., PROGRAMME AND ABSTRACTS THE VOLCANOLOGICAL SOCIETY OF JAPAN, 2013, 0, 91, 91, 2013
  The Volcanological Society of Japan, Japanese
• COEXISTING NITROGEN- RICH AND POOR ORGANIC MATERIALS IN ULTRACARBONACEOUS ANTARCTIC MICROMETEORITE.
  H. Yabuta; S. Itoh; T. Noguchi; N. Sakamoto; M. Hashiguchi; K. Abe; S. Tsujimoto; D. Kilcoyne; A. Okubo; R. Okazaki; S. Tachibana; K. Terada; T. Nakamura; H. Nagahara, METEORITICS & PLANETARY SCIENCE, 47, A420, A420, Jul. 2012
  English, Summary international conference
• Survey of Presolar Remnants Remained in Meteorites by Isotope Microscope
  YURIMOTO Hisayoshi; SAKAMOTO Naoya, KENBIKYO, 47, 2, 92, 97, 30 Jun. 2012
  

  Laboratory analysis of space materials is an important method to study origin of solar system. Among the laboratory analysis, microscopy is very useful because space materials have complex and fine structures. Large differences of isotopic composition are common among the space materials. Isotopes can be used as tracers to study origin and evolution of space materials. Conventional mass spectrometry is limited to apply for microanalysis, but recently, isotope microscopy is developed and the situation is gradually changed. The isotope microscopy can obtain precise isotopic image of fine structures of space materials and analyze formation processes of the structure in detail. Here we report studies of oldest materials of the solar system, presolar grains formed in circum stellar, and ice fossils formed in molecular cloud.

  , The Japanese Society of Microscopy, Japanese
• 酸化亜鉛を添加した酸化スズセラミックス中の欠陥と緻密化に関する研究
  SAKAGUCHI ISAO; SAKAMOTO NAOYA; YURIMOTO HISAYOSHI; OHASHI NAOKI; HISHITA SHUN'ICHI, セラミックス基礎科学討論会講演要旨集, 50th, 21, 12 Jan. 2012
  Japanese
• Origin of a sapphirine-bearing Al-rich chondrule in the DaG 978 ungrouped chondrite
  Aicheng Zhang; Shoichi Itoh; Naoya Sakamoto; Hisayoshi Yurimoto; Rucheng Wang, Abstracts of Annual Meeting of the Geochemical Society of Japan, 59, 0, 269, 269, 2012
  We report mineralogy, oxygen isotopic and rare-earth-element compositions of a sapphirine-bearing Al-rich chondrule (SARC) from the Dar al Gani (DaG) 978 ungrouped carbonaceous chondrite. Our results indicate that the precursor of SARC included Group II CAIs as components. Assimilation of incompletely melted amoeboid olivine aggregate also occurred during formation of the ferromagnesian rim in SARC., GEOCHEMICAL SOCIETY OF JAPAN, Japanese
• S12-03 イトカワ母天体の熱進化(口頭セッション12:はやぶさ,口頭発表)
  圦本 尚義; 中村 智樹; 伊藤 正一; 坂本 直哉; 阿部 憲一; 橋口 未奈子; 片山 樹里; 加藤 千図; 川崎 教行; 小林 幸雄; 女池 竜二; 朴 昌根; 武井 将志; 若木 重行; 山本 広佑; 橋爪 光; 土山 明; 瀬戸 雄介; 長尾 敬介; 野口 高明; 海老原 充; 奈良岡 浩; 北島 富美雄; 岡崎 隆司; Ireland T.R.; Zolensky M.E.; 阿部 正真; 藤村 彰夫; 川口 淳一郎; 向井 利典; 上椙 真之; 矢田 達; 吉川 真, 日本惑星科学会秋期講演会予稿集, 2011, 15, 15, 23 Oct. 2011
  日本惑星科学会, Japanese
• 同位体顕微鏡,FTIRイメージング,顕微ラマン分光を用いた骨代謝に関する研究
  KIMURA(SUDA) HIROMI; KAJIHARA MAKOTO; SAKAMOTO NAOYA; KOBAYASHI SACHIO; IJIRO KUNIHARU; YURIMOTO HISAYOSHI; YAMATO HIDEYUKI, J Oral Biosci, 53, Supplement, 84, 84, 01 Sep. 2011
  (一社)歯科基礎医学会, Japanese
• 赤外イメージングおよび元素イメージングによる生体組織の解析
  木村 須田 廣美; 桑原 三恵子; 日高 公介; 金沢 恭祐; 本間 教嗣; 坂内 堅二; 菅野 三喜男; 梶原 誠; 大西 晃宏; 小林 幸雄; 坂本 直哉; 居城 邦治; 圦本 尚義; 大和 英之, バイオイメージング, 20, 2, 95, 96, 10 Aug. 2011
  Japanese
• 女性研究者がリードするバイオイメージング 赤外イメージングおよび元素イメージングによる生体組織の解析
  木村 廣美; 須田; 桑原 三恵子; 日高 公介; 金沢 恭祐; 本間 教嗣; 坂内 堅二; 菅野 三喜男; 梶原 誠; 大西 晃宏; 小林 幸雄; 坂本 直哉; 居城 邦治; 圦本 尚義; 大和 英之, バイオイメージング, 20, 2, 95, 96, Aug. 2011
  日本バイオイメージング学会, Japanese
• Oxygen isotopic compositions, ²⁶Al initial abundances and trace element compositions of asteroid Itokawa
  Yurimoto Hisayoshi; Nakamura Tomoki; Noguchi Takaaki; Nagao Keisuke; Ebihara Mitsuru; Naraoka Hiroshi; Okazaki Ryuichi; Kitajima Fumio; Mukai Toshifumi; Fujimura Akio; Abe Masanao; Itoh Shoichi; Sakamoto Naoya; Kobayashi Sachio; Hashizume Ko; Tsuchiyama Akira; Seto Yusuke; T. R. Ireland; M. Zolensky, Abstracts of Annual Meeting of the Geochemical Society of Japan, 58, 0, 171, 171, 2011
  太陽系形成期の研究は，主に隕石を参照することにより検証がおこなわれ，進展して来た．隕石は小惑星の破片であるといわれているが，母天体となる小惑星が確認されている隕石は一つもない．小惑星イトカワにタッチダウンした惑星探査機はやぶさが，昨年，小惑星イトカワの表面物質を地球に持ち帰った．採取された試料は，最大で数百ミクロンの微粒子であるが，これらの試料を分析することにより，小惑星と隕石との関係の一部が初めて明らかになっていくことが期待される． 本講演では，酸素同位体組成，マグネシウム同位体組成戸26Al，微量元素組成について報告する．, GEOCHEMICAL SOCIETY OF JAPAN
• Petrography of Fluffy Type A CAI from Efremovka CV3 chondrite and oxygen isotopic compositions of melilite
  Kawasaki Noriyuki; Sakamoto Naoya; Yurimoto Hisayoshi, Abstracts of Annual Meeting of the Geochemical Society of Japan, 58, 0, 178, 178, 2011
  本研究では，エフレモフカCV3コンドライト中のFluffy Type A CAIの岩石学的記載と，累帯構造を持つメリライト結晶の固溶体組成および酸素同位体組成の分析を行った．本CAIは，内部にWark-Loveringリムの断片のような構造があり，領域によって岩石学的特徴が異なることから，大きく4つのドメインに分類できる．各ドメインはその構造，鉱物組合せなどが異なり，特に2つのドメインのメリライトの固溶体組成と酸素同位体組成に違いが見られた．各ドメインの境界は大部分はWark-Loveringリムやその断片のような構造で区切られており，各ドメインは別々に形成され集合したものであると考えられる．, GEOCHEMICAL SOCIETY OF JAPAN
• 「初期太陽系物質科学の最前線」Acfer 094隕石における宇宙シンプレクタイトの存在度
  阿部憲一; 坂本直哉; 圦本尚義, 日本惑星科学会誌 遊・星・人, 19, 4, 268, 272, 25 Dec. 2010
  Japanese
• Abundance of Cosmic Symplectite in Acfer 094 carbonaceous chondrite
  ABE Kenichi; SAKAMOTO Naoya; YURIMOTO Hisayoshi, Planetary people, 19, 4, 268, 272, 25 Dec. 2010
  宇宙シンプレクタイト(COS)は現在知られている太陽系物質の中で最も重い酸素同位体組成を持ち,太陽系初期の水に由来することが示唆されている.COSが原子数比でFe:O:S&ap;4:4:1の特徴的な化学組成を保持していることを利用して,FE-SEM-EDSによりAcfer 094隕石の広範囲かつ高空間分解能なX線元素マッピングを行い,COSを探索した.1mm四方の元素マップを7面取得し,1〜260μm^2の大きさのCOSを66個同定した.COSの平均面積は32μm^2,個数存在度は9個/mm^2であり,Acfer 094隕石マトリックスにおいて体積存在度521ppmで普遍的に存在することが明らかになった., The Japanese Society for Planetary Sciences, Japanese
• Microstructure and its origin of isotopically anomalous material COS in the Acfer 094 carbonaceous chondrite
  SETO Yusuke; TOH Shoichi; SAKAMOTO Naoya; YURIMOTO Hisayoshi, 日本鉱物科学会年会講演要旨集, 2010, 157, 157, 23 Sep. 2010
  Japanese
• A Mineralogical Consideration on the Growth Process of Aragonite in Coral Skeletons
  MOTAI Satoko; NAGAI Takaya; SOWA Kohki; WATANABE Tsuyoshi; SAKAMOTO Naoya; YURIMOTO Hisayoshi, 日本鉱物科学会年会講演要旨集, 2010, 84, 84, 23 Sep. 2010
  Japanese
• 安定同位体を標識とした細胞イメージング
  YAMAMOTO KOSUKE; SAKAMOTO NAOYA; NISHIO TAKASHI; IJIRO KUNIHARU; YURIMOTO HISAYOSHI, 日本分析化学会年会講演要旨集, 59th, 168, 01 Sep. 2010
  Japanese
• 同位体顕微鏡システムおよび振動分光法によるマウス骨質の解析
  KIMURA(SUDA) HIROMI; KAJIHARA MAKOTO; SAKAMOTO NAOYA; KOBAYASHI SACHIO; IJIRO KUNIHARU; YURIMOTO HISAYOSHI; YAMATO HIDEYUKI, 高分子学会予稿集(CD-ROM), 59, 2 Disk1, ROMBUNNO.2PE123, 01 Sep. 2010
  Japanese
• D/H ZONING IN APATITE OF MARTIAN METEORITES QUE 94201 AND LOS ANGELES: IMPLICATIONS FOR WATER ON MARS
  J. P. Greenwood; S. Itoh; N. Sakamoto; E. P. Vicenzi; H. Yurimoto, METEORITICS & PLANETARY SCIENCE, 45, A68, A68, Jul. 2010
  English, Summary international conference
• Relationship between the abundance of presolar grains and metamorphic degree in carbonaceous and ordinary chondrites
  KOBAYASHI S.; NAGASHIMA K.; TONOTANI A.; SAKAMOTO N.; ITOH S.; RUSSELL S. S.; KROT Alexander N.; YURIMOTO H., 日本鉱物科学会年会講演要旨集, 2009, 223, 223, 07 Apr. 2010
  Japanese
• Variations of chemical composition of matrices of carbonaceous chondrites
  ABE K.; SAKAMOTO N.; KOJIMA H.; KROT A. N.; RUSSELL S. S.; YURIMOTO H., 日本鉱物科学会年会講演要旨集, 2009, 224, 224, 07 Apr. 2010
  Japanese
• 同位体顕微鏡システムによる骨形成の解析
  KIMURA(SUDA) HIROMI; KAJIHARA MAKOTO; SAKAMOTO NAOYA; KOBAYASHI SACHIO; IJIRO KUNIHARU; YURIMOTO HISAYOSHI; YAMATO HIDEYUKI, 日本骨代謝学会学術集会プログラム抄録集, 28th, 163, 163, 2010
  (一社)日本骨代謝学会, Japanese
• VARIATIONS OF CHEMICAL COMPOSITION OF MATRICES OF CARBONACEOUS CHONDRITES
  K. Abe; N. Sakamoto; H. Kojima; A. N. Krot; H. Yurimoto, METEORITICS & PLANETARY SCIENCE, 44, A15, A15, Jul. 2009
  English, Summary international conference
• DEVELOPMENT OF NEW SCAPS ION DETECTOR
  N. Sakamoto; S. Aoyama; S. Kawahito; H. Yurimoto, METEORITICS & PLANETARY SCIENCE, 44, A181, A181, Jul. 2009
  English, Summary international conference
• 重い酸素同位体に富む太陽系物質の発見
  坂本直哉, 日本惑星科学会誌 遊・星・人, 18, 1, 25, 30, 25 Mar. 2009
  Acfer 094隕石中の磁鉄鉱(Fe_3O_4)と鉄ニッケル硫化物からなるユニークな微細結晶集合体が,太陽系物質で最も重い酸素同位体組成を持つことを発見した.熱力学計算により原始惑星系円盤における磁鉄鉱と硫化鉄の共存条件を求めたところ,この物質は太陽系星雲中では金属鉄または硫化鉄が重い酸素同位体組成を持つH_2Oと360K以下で反応して形成し,隕石母天体上で周囲のケイ酸塩との同位体交換が平衡に達していない事がわかった.このことから,太陽系の始原的な水が重い酸素同位体組成を持つことを示す., The Japanese Society for Planetary Sciences, Japanese
• Discovery of the solar system material enriched in heavy oxygen isotopes
  Sakamoto Naoya, Planetary People, 18, 1, 25, 30, 25 Mar. 2009
  Acfer 094隕石中の磁鉄鉱(Fe_3O_4)と鉄ニッケル硫化物からなるユニークな微細結晶集合体が,太陽系物質で最も重い酸素同位体組成を持つことを発見した.熱力学計算により原始惑星系円盤における磁鉄鉱と硫化鉄の共存条件を求めたところ,この物質は太陽系星雲中では金属鉄または硫化鉄が重い酸素同位体組成を持つH_2Oと360K以下で反応して形成し,隕石母天体上で周囲のケイ酸塩との同位体交換が平衡に達していない事がわかった.このことから,太陽系の始原的な水が重い酸素同位体組成を持つことを示す., The Japanese Society for Planetary Sciences, Japanese
• Development of high-sensitivity ion imager corresponding to real-time readout
  Sakamoto Naoya; Aoyama Satoshi; Kawahito Shoji; Yurimoto Hisayoshi, Abstracts for Annual Meeting of Japan Association of Mineralogical Sciences, 2009, 0, 230, 230, 2009
  High-sensitivity ion imager corresponding to real-time readout with 250000 pixels is developed. The output signal fluctuation of the pixel caused by 1 incident ion was 150µV/ion pixel which is 5 times improved by adopting smaller pixel capacitance. In order to reduce the readout noise, multiple signal-sampling mechanism was incorporated. The readout noise was achieved to 250 µV corresponding to 1.7 ions with 16 times signal-sampling. The readout speed was achieved to 12.5 frames/sec with single sampling and 8.3 frames/sec with 16 times signal-sampling. The read noise is independent of read out speed and now optimizing with multiple signal-sampling mechanism. Therefore, real-time single ion detection is expected if all the parameters become optimized., Japan Association of Mineralogical Sciences, Japanese
• Chemistry and microstructure, of cos from Acfer 094 carbonaceous chondrite
  Y. Seto; N. Sakamoto; K. Fujino; H. Yurimoto, METEORITICS & PLANETARY SCIENCE, 43, 7, A143, A143, Jul. 2008
  English, Summary international conference
• Mineral phases, chemical composition and microstructure of ^17,18O-rich material "COS" in Acfer 094
  Seto Yusuke; Sakamoto Naoya; Fujino Kiyoshi; Yurimoto Hisayoshi, Abstracts for Annual Meeting of Japan Association of Mineralogical Sciences, 2008, 0, 206, 206, 2008
  We report mineral characterization of the isotopically anomalous material "COS" in the carbonaceous chondrite Acfer 094 using synchrotron radiation X-ray diffraction analysis and transmission electron microscopy. The results show following clear differences between the samples having high Ni content (High-Ni COS) and low Ni content (low-Ni COS); (1) The high-Ni COS grain consists of magnetite + pentlandite, while the low-Ni one consists of magnetite + pyrrhotite. (2) The high-Ni one is an aggregate of magnetite-pentlandite showing a symplectitic texture in tens nm scale, while the low-Ni one is an aggregate consisting of idiomorphic magnetite (∼100nm) and pyrrhotite (∼50nm) grains.We infer that the COS grains were formed by sulfurization and oxidization of metal grains. The chemical and micro-structural differences are probably reflected in the texture and the chemistry of precursor materials before the oxidization., Japan Association of Mineralogical Sciences, Japanese
• Microstructure Observations on Coral Skelton
  Motai Satoko; Nagai Takaya; Sakamoto Naoya; Sowa Kohki; Watanabe Tuyoshi; Yurimoto Hisayoshi, Abstracts for Annual Meeting of Japan Association of Mineralogical Sciences, 2008, 0, 175, 175, 2008
  Mineral phase identification of the coral skeletal microstructure is important for reconstructing the paleo-climate. Especially, chemical composition of Porites sp. is widely used as a paleo-environment variant. For example, it is believed that Sr/Ca ratio in coral skeletons is sensitive to temperature of seawater. Recently, Greegor et al. (1997) reported that as much as 40% of strontium (Sr) in coral aragonite existed as a SrCO₃ end member by using XANES and EXAFS. This should be a very serious problem, when we apply the Sr/Ca ratio to reconstruct the paleo-environment. However, since there has been no direct mineral identification of SrCO₃, we have carefully observed Porites sp. by FE-ASEM and ATEM in order to identify mineral phases in the coral skeletal., Japan Association of Mineralogical Sciences, Japanese
• Sulfur isotope compositions of sulfides surrounding a presolar SiC grain
  Ebata Shingo; Sakamoto Naoya; Yurimoto Hisayoshi, Abstracts of Annual Meeting of the Geochemical Society of Japan, 55, 0, 375, 375, 2008
  プレソーラー粒子は太陽系形成以前に存在した太陽系を作る材料粒子であり、単独でマトリックス中に埋まっている。2007年江端らによってカンラン石や金属鉄とともにFeSで囲まれていたプレソーラーSiC粒子（SEC_ALH07）がEH3コンドライトから発見された。本研究では、周囲の組織の起源を解明する事を目的とし周囲を取り囲んでいるFeSの硫黄同位体組成分析を行った。‹BR›FeSの硫黄同位体組成は、δ‹SUP›33‹/SUP›S=-71±45‰, δ‹SUP›34‹/SUP›S=-48±56‰, δ‹SUP›36‹/SUP›S=27±173‰（誤差1σ）であった。δ‹SUP›34‹/SUB›S, δ‹SUP›36‹/SUP›Sの同位体組成は2 σの誤差内で太陽系の同位体組成と同じである事を示す。また、江端らの酸素同位体測定の報告によると内包されているカンラン石は太陽の同位体組成と同じであった。これらの結果は、周囲の硫化物はプレソーラーSiC粒子を核としてカンラン石や金属鉄と共に原始太陽系内において形成されたものである事を示唆する。, GEOCHEMICAL SOCIETY OF JAPAN
• Mineralogical characterization of ^<17,18>O-rich materials in a primitive carbonaceous chondrite, Acfer 094
  SETO Yusuke; SAKAMOTO Naoya; YURIMOTO Hisayoshi; FUJINO Kiyoshi, 日本鉱物学会・学術講演会,日本岩石鉱物鉱床学会学術講演会講演要旨集, 2007, 77, 77, 22 Sep. 2007
  English
• Origin of 17,180-rich materials from ACFER 094
  N. Sakamoto; Y. Seto; S. Itoh; K. Kuramoto; K. Fujino; K. Nagashima; A. N. Krot; H. Yurimoto, METEORITICS & PLANETARY SCIENCE, 42, A134, A134, Aug. 2007
  English, Summary international conference
• X-ray diffraction and transmission electron microscopic studies of new-PCP from Acfer 094 carbonaceous chondrite
  Y. Seto; N. Sakamoto; K. Fujino; H. Yurimoto, METEORITICS & PLANETARY SCIENCE, 42, A140, A140, Aug. 2007
  English, Summary international conference
• サンゴ骨格の日輪構造内における酸素同位体比組成
  WATANABE TAKESHI; SOWA KOKI; SAKAMOTO NAOYA; YORIMOTO YORIYOSHI, 日本地球化学会年会講演要旨集, 54th, 239, 2007
  Japanese
• Non-heterogenous oxygen isotopic distribution in coral microstructures
  Watanabe Tsuyoshi; Sowa Koki; Sakamoto Naoya; Yurimoto Hisayoshi, Abstracts of Annual Meeting of the Geochemical Society of Japan, 54, 0, 219, 219, 2007
  Massive corals have been widely used as proxies for past changes in sea surface temperature (SST) of the tropical and subtropical oceans because the oxygen isotopic and strontium/calcium (Sr/Ca) ratios of their aragonitic skeletons are believed to vary as a function of the temperature of the ambient seawater. However, recent microanalytical studies using secondary ion mass spectrometry (SIMS) have revealed large chemical heterogeneities for Sr/Ca and oxygen isotopic ratios in coral skeleton, which cannot be explained by temperature variation (e.g. Meibom et al., 2004, Rollin-Bard, et al., 2003), GEOCHEMICAL SOCIETY OF JAPAN

• 原始太陽系円盤における物質の時空間分布と輸送作用の解明
  科学研究費助成事業
  Apr. 2025 - Mar. 2029
  川崎 教行; 荒川 創太; 馬上 謙一; 山本 大貴; 坂本 直哉
  日本学術振興会, 基盤研究(A), 北海道大学, 25H00678
• クライオ同位体顕微鏡による太陽系水進化の解明
  2022 - 2028
  坂本 直哉
  太陽系は、最初期に固体物質と始原水が混合して形成したと考えられています。本提案は、太陽系における水の進化過程を解明するために、物質中の水を凍らせたまま同位体の３次元分布を可視化するクライオ同位体顕微鏡により、隕石や宇宙探査機が持ち帰った地球外物質に含まれる宇宙の水の同位体組成分布を決定します。成果は、宇宙分野だけなく、地球科学や材料物質科学、生命科学など幅広い分野への応用が期待されます。
  科学技術振興機構, 戦略的な研究開発の推進/創発的研究支援事業, 21466785
• 最下部マントル物質の粘性率の決定
  科学研究費助成事業
  01 Apr. 2022 - 31 Mar. 2027
  山崎 大輔; 辻野 典秀; 芳野 極; 坂本 直哉
  日本学術振興会, 基盤研究(A), 岡山大学, 22H00180
• Light elements in the Earth's core revealed by ultrahigh-pressure experiments
  Grants-in-Aid for Scientific Research
  18 May 2021 - 31 Mar. 2026
  廣瀬 敬; 太田 健二; 坂本 直哉; 梅本 幸一郎; 圦本 尚義; Alfred Baron
  Japan Society for the Promotion of Science, Grant-in-Aid for Specially Promoted Research, The University of Tokyo, 21H04968
• Multi-scale Imaging of Water Molecules using MRI and Isotope Microscope
  Grants-in-Aid for Scientific Research
  01 Apr. 2021 - 31 Mar. 2024
  工藤 與亮; 村上 正晃; 小畠 隆行; 小牧 裕司; 杉森 博行; 坂本 直哉; 亀田 浩之; 安井 正人
  ①MRI撮像法開発：O-17標識水の存在によるT2値の短縮を定量的に計測してO-17濃度を定量解析するため、プリパルスを利用した高速T2 mapping法を開発して最適化を行った。異なる濃度のO-17標識水を含有した濃度ファントムを作成し、高速T2 mapping法と従来のFSE法によるT2 mapping法の精度を比較した。従来法と比較して高精度のT2値測定が可能となった。
  ②正常動物・疾患モデル動物でのMRI撮像：正常マウスやラットにてO-17標識水の静脈内投与法や髄腔内投与法、頸動脈内投与法、腹腔内投与法などを確立した。静脈内投与や頸動脈内投与によって脳内の有意なMRI信号変化を確認した。水中毒モデルラットにO-17標識水を腹腔内投与してMRI撮像を行い、AQP4欠損ラットとの比較を行った。AQP4欠損によって脳内の水貯留が増加することが明らかになった。ALSモデルマウス・ラットにてO-17標識水を静脈内投与してMRI撮像を行った。野生型と比較して錐体路での水漏出が増加していることが明らかとなった。
  ③同位体顕微鏡による水分子イメージング：新たに導入した多機能コーティング装置を用いて凍結下での標本作成から同位体顕微鏡によるイメージングまでの解析手順を確立した。ラット脳にO-18標識水を直接注入し、注入部位でのO-18濃度の上昇を確認した。摘出したラット肝の門脈内にO-18標識水を注入し、血管内や類洞内のO-18濃度の上昇を確認した。
  ④ヒトでのMRI撮像：認知症患者を対象にしたO-17標識水の髄腔内投与研究にて、特発性正常圧水頭症患者とアルツハイマー型認知症患者で、髄腔内の水吸収速度に差があることを見出した。
  Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (B), Hokkaido University, 21H02857
• 水素の高ダイナミックレンジ定量イメージング
  科学研究費助成事業 基盤研究(B)
  01 Apr. 2020 - 31 Mar. 2024
  坂本 直哉
  水素をイメージング可能な同位体顕微鏡の二次元イオン検出システムを高ダイナミックレンジ化する手法を開発し、固体物質表面の多量の水素と極微量な水素を同一視野において同時にイメージング可能とする。
  本年度は、昨年度までに開発した選択的画素リセットを行うイメージングシステムを用いて、実際の隕石に含まれる難揮発性包有物を分析した。同一視野内の鉱物間で数桁の濃度分布が分かっているマグネシウムとアルミニウム同位体をイメージングした。通常、数分で画素キャパシタが飽和して信号が取得不可になる条件において、画素を飽和させずに６時間以上の分析が可能であることが分かり、６桁を超えるダイナミックレンジのイメージングが可能となった。今後は、基本動作の精度をブラッシュアップしつつ、水素の高ダイナミックレンジイメージングを実行する。
  日本学術振興会, 基盤研究(B), 北海道大学, 20H01990
• 高圧下の鉄合金の特性とコアの軽元素組成の制約
  科学研究費助成事業
  05 Apr. 2021 - 31 Mar. 2022
  廣瀬 敬; 太田 健二; 坂本 直哉; 梅本 幸一郎; 圦本 尚義
  結果的に１ヶ月半という期間となった本課題について、以下の７つの研究を進めた。１）SPring-8のビームラインBL43LXUにおけるX線非弾性散乱法を使った液体FeOの縦波速度測定に関し、過去の測定データの解析と６月のビームタイムに向けた実験準備を行った。また２）同じくSPring-8のビームラインBL10XUにおけるX線回折測定によって、超高圧高温まで 固体Feの格子体積を求め、状態方程式を決定するためのデータを解析した。さらに３）固体FeHの高圧高温下における体積データから高温の状態方程式を作成するとともに、４）Fe-FeH系の高圧高温実験を行って、状態図の作成を試みた。クライオ二次イオン質量分析法を使って、回収試料の三次元水素濃度マッピングを行い、水素の定量分析法の開発を進めた。５）Fe-Si系の実験も200万気圧までやり直し、共融点の化学組成の圧力変化を正確に見積もった。６）コア形成時の金属-シリケイト分配についても二次イオン質量分析法を使った定量を行い、水素（水）が系に含まれることにより、硫黄と炭素の分配係数が大きく変化する（メタルに分配されにくくなる）ことを見つけた。最後に、７）沈み込んでいく海洋プレート（スラブ）は水をコアーマントル境界まで輸送し、その高温環境下で脱水した水はコアの金属鉄と化学反応を起こして、鉄水酸化物などを作ると従来考えられていた。ところが今回二次イオン質量分析法を使って行った、含水SiO2相の含水量を定量する実験によって、スラブが運んだ水は脱水せず、コアーマントル境界域に水を供給しないことが明らかになった。
  日本学術振興会, 基盤研究(A), 東京大学, 21H04506
• RANK/RANKL/OPG signaling upregulates IL-10 -regulated anti-inflammatory response during Candida albicans Infection
  Grants-in-Aid for Scientific Research
  01 Apr. 2019 - 31 Mar. 2022
  Kobayashi Michiyo
  Receptor activator of nuclear factor-kappa B ligand (RANKL) to RANK interactions are critical to pathogenesis in immune cells. Osteoprotegerin (OPG) prevents binding of RANKL to RANK. This study utilized a mouse model (orally inoculated) to determine if there was a correlation between superficial candidiasis, commonly caused by the opportunistic fungus Candida albicans, and RANK/RANKL/OPG. Upregulation of OPG, RANKL, and RANK mRNA expression were found in mice whose oral cavity had a superficial C. albicans infection. Moreover, administration of exogenous soluble RANKL upregulated the mRNA of RANK in the infected tissue. Exogenous soluble RANKL also upregulated the mRNA of IL-10, which prompted anti-inflammatory effects including wound healing. Therefore, our data suggested that RANK/RANKL/OPG signaling might play a role in the pathogenesis of candidiasis, making this the first study to show the relationship between this opportunistic infection and the RANK/RANKL/OPG axis.
  Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (C), Ohu University, 19K10343
• 表面分析法による菌根における炭素・窒素・水素の細胞輸送と循環解析
  科学研究費助成事業 基盤研究(B)
  01 Apr. 2017 - 31 Mar. 2021
  久我 ゆかり; 勝山 千恵; 坂本 直哉; 長谷川 巧; 青柳 里果
  本研究は，植物と真菌の共生である菌根において、炭素、窒素、水素の共生者間－組織内輸送および環境との循環を、細胞小器官レベルでの局在解析手法を中心に明らかにすることを目的としている。
  課題Ⅰ「表面分析法における試料調整法の影響評価」では，凍結試料を用いた安定同位体トレーサーの二次イオン質量分析法（SIMS）の開発に引き続き取り組んだ。高真空装置で凍結試料を測定するための，試料側の凍結法，表面作成法など，また，機械的な試料輸送・導入法，凍結ステージの開発はほぼ完成した。H30年度は特に，表面の導電性の改良に取り組み，測定法などの検討を行った。生細胞における安定同位体測定法の検討では，酵母をモデルとして用い，同位体標識リン酸を与えた真菌液胞内のポリリン酸の動態・分布を顕微ラマン散乱の手法を用いて明らかにすることを目指し，測定手法の確立に引き続き取り組んだ。本年度は，樹脂包埋試料作製における方法論の違いを検討するため，加圧凍結-凍結置換法の導入を検討した。
  課題Ⅱ「同位体分子情報」では，アーバスキュラー菌根共生における宿主から渡される分子として推定される脂質および糖質の解析のため，TOF-SIMS法の導入に着手した。
  課題Ⅲ「物質輸送と循環」では，アーバスキュラー菌根における物質輸送を同位体トレーサーの微細構造局在解析により明らかにするため，本研究で確立した同一試料を用いた透過型電子顕微鏡-SIMS法解析法を用い，分析を進めた。また，アーバスキュラー菌根における水輸送を解析するため，菌糸のみにトレーサーを与える培養系を確立した。土壌生態系における元素循環では，温度ストレスを与えた土壌中の菌糸圏微生物群（細菌および糸状菌）について，次世代シークエンサーを用いた群集構造解析を行った。
  日本学術振興会, 基盤研究(B), 広島大学, 17H03784
• Vapor Growth of Forsterite in Protoplanetary Disks: Anisotropy and Its Application to Astromineralogy
  Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (B)
  01 Apr. 2013 - 31 Mar. 2016
  Tachibana Shogo; Akira Miyake; Naoya Sakamoto; Jun Kawano
  Vapor growth experiments on forsterite, a major silicate mineral in space, were conducted under controlled protoplanetary disk conditions in order to understand its vapor growth kinetics. The growth experiments of forsterite at 1350 K in the presence of hydrogen gas (5 Pa) containing H2O (H2O/H2=0.05) were done at the supersaturation ratio of 15-20, and we found that the condensation coefficient of forsterite, a non-dimension parameter representing kinetic hindrance for vapor growth, is in the range of 0.003-0.006.
  Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (B), Hokkaido University, 25287140
• Origin of -OH in meteoritic hydrous minerals
  Grants-in-Aid for Scientific Research Grant-in-Aid for Young Scientists (B)
  01 Apr. 2013 - 31 Mar. 2015
  SAKAMOTO Naoya
  Meteorites contain aqueous altered minerals having information of parent body water. Because metal in primitive meteorites contains no oxygen species originally, comparison between oxidized metal in meteorite and experimental products is useful to understand the oxidation in the early solar system. In this study, oxygen isotope imaging for aqueous laterd minerals was performed using automated isotope microscope system and developed an oxygen isotope experimental instrument using a sorption pump.
  Japan Society for the Promotion of Science, Grant-in-Aid for Young Scientists (B), Hokkaido University, 25800299
• Mineral isochron of fine grained CAI using stigmatic isotope imaging method
  Grants-in-Aid for Scientific Research Grant-in-Aid for Challenging Exploratory Research
  01 Apr. 2012 - 31 Mar. 2013
  SAKAMOTO Naoya
  Development of stigmatic isotope imaging method and new ion imager required in order to obtain a mineral isochron from fine-grained CAIs were carried out using stigmatic-type secondary ion mass spectrometry. Magnesium isotope images of fine-grained CAI were obtained and the read-out speed of the ion imager achieved 150 frames per seconds.
  Japan Society for the Promotion of Science, Grant-in-Aid for Challenging Exploratory Research, Hokkaido University, 24654179
• Anatomy of protosolar system
  Grants-in-Aid for Scientific Research Grant-in-Aid for Specially Promoted Research
  2008 - 2012
  YURIMOTO Hisayoshi; TACHIBANA Shogo; ITOH Shoichi; SAKAMOTO Naoya; OTSUKI Kaori
  All types of primitive chondrites were analyzed isotopically insub-micrometer scale by isotope microscopy. Materials formed in pre-solar and early solar system agesare distinguished isotopically. The spatial distribution between the materials corresponds to formationsequences suggesting material evolution from presolar to early solar ages. Based on these results, wediscussed global and local characteristics of our solar system among planetary systems in the galaxy.
  Japan Society for the Promotion of Science, Grant-in-Aid for Specially Promoted Research, Hokkaido University, 20002002
• 高感度同位体顕微鏡システムの開発と隕石への応用
  科学研究費助成事業 特別研究員奨励費
  2007 - 2007
  坂本 直哉
  最近、申請者は同位体顕微鏡を用いて炭素質コンドライトAcfer 094から太陽系で最も17Oと18Oに富む物質を発見した。同位体顕微鏡とは、二次イオン質量分析装置と独自開発の二次元イオン検出器を組み合わせた、固体表面微小部分の同位体比変動の空間分布を分析可能な装置である。この物質の酸素同位体組成は、原始太陽系星雲の始源水を反映していると示唆されており、その存在の普遍性を調べることは初期太陽系形成時の物質進化を解明する上で重要である。本研究では、同位体顕微鏡を高感度化したシステムを開発することにより、他の隕石においてこの物質を迅速に探索することを目的としている。高感度化のために、検出器の蓄積信号を複数回読み出して平均化処理を行う読み出し方式を採用し、読み出しノイズxの低減を図った。その結果、読み出し回数に応じてノイズが低減され、この方式が有効であることを確認できた。また、信号強度が微弱な場合の読み出し方式を確立し、最適な読み出し回数を定式化した。これらの読み出し方式を最適化するための新しい制御システムを開発した。このシステムでは、必要な全てのモジュールが同一の工業用シャーシに格納され全てLabVIEWソフトェアで制御しており、駆動パルスの生成コードのVHDLからLabVIEWへの移植、駆動電圧の変更を容易にしたことにより柔軟な分析の最適化が可能となった。このシステムを同位体顕微鏡に取り付けて動作することを確認した。17Oと18Oに富む物質は磁鉄鉱と硫化鉄から構成されるが、Acfer 094には磁鉄鉱がほとんどない。
  そこで、11種類の隕石について電界放出型電子顕微鏡を用いて観察し、各隕石に含まれる磁鉄鉱と硫化鉄の比率の違いから分析候補を選定する指標を得た。
  日本学術振興会, 特別研究員奨励費, 北海道大学, 07J02997