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1. The Ni isotopic composition of Ryugu reveals a common accretion region for carbonaceous chondrites

Author

Spitzer, Fridolin, Kleine, Thorsten, Burkhardt, Christoph, Hopp, Timo, Yokoyama, Tetsuya, Abe, Yoshinari, Aléon, Jérôme, Alexander, Conel M. O'D., 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, Itoh, Shoichi, Kawasaki, Noriyuki, Kita, Noriko T., Kitajima, Kouki, Komatani, Shintaro, Krot, Alexander N., Liu, Ming-Chang, Masuda, Yuki, Morita, Mayu, Moynier, Fréderic, Motomura, Kazuko, Nakai, Izumi, Nagashima, Kazuhide, Nguyen, Ann, Nittler, Larry, Onose, Morihiko, Pack, Andreas, Park, Changkun, Piani, Laurette, Qin, Liping, Russell, Sara S., Sakamoto, Naoya, Schönbächler, 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, and Yurimoto, Hisayoshi

Subjects
Astrophysics - Earth and Planetary Astrophysics
Abstract

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 and 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 and Ryugu may have formed in the same region of the accretion disk as other carbonaceous chondrites., Comment: Published open access in Science Advances

Published
2024
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2. Homogenization of layered materials with rigid components in two-slip finite crystal plasticity

Author

Ishikawa, Akira and Svadlenka, Karel

Subjects
Mathematics - Analysis of PDEs, Mathematics - Optimization and Control, 49J45 (Primary) 74Q05, 74C15 (Secondary)
Abstract

This paper is an extension of the result by Christowiak and Kreisbeck (2017), which addresses the Gamma-convergence approach to a homogenization problem for composite materials consisting of two distinct types of parallel layers. In Christowiak et al. (2017), one of the layers of the material undergoes only local rotations while the other allows local rotation and plastic deformation along a single slip system. On the other hand, real materials show an interplay of multiple directions of slip. Here we obtain the Gamma-limit for the problem where the number of slip directions is increased to two. When the slip systems are orthogonal, we derive the full homogenized energy based on generalized convex envelopes of the original energy density. Since these envelopes are not completely known for angles between slip directions differing from the right angle, we present a partial, conditional homogenization result in this general case. The analysis is based on a modification of the classical construction of laminate microstructures but several nontrivial difficulties arise due to nonconvex constraints being present in the composite energy.

Published
2024

11. Analysis of Cation Composition in Dolomites on the Intact Particles Sampled from Asteroid Ryugu.

Author

Morita, Mayu, Yui, Hiroharu, Urashima, Shu-Hei, Onose, Morihiko, Komatani, Shintaro, Nakai, Izumi, Abe, Yoshinari, Terada, Yasuko, Homma, Hisashi, Motomura, Kazuko, Ichida, Kiyohiro, Yokoyama, Tetsuya, Nagashima, Kazuhide, Aléon, Jérôme, OD Alexander, Conel, Amari, Sachiko, Amelin, Yuri, Bajo, Ken-Ichi, Bizzarro, Martin, Bouvier, Audrey, Carlson, Richard, Chaussidon, Marc, Choi, Byeon-Gak, Dauphas, Nicolas, Davis, Andrew, Fujiya, Wataru, Fukai, Ryota, Gautam, Ikshu, Haba, Makiko, Hibiya, Yuki, Hidaka, Hiroshi, Hoppe, Peter, Huss, Gary, Iizuka, Tsuyoshi, Ireland, Trevor, Ishikawa, Akira, Itoh, Shoichi, Kawasaki, Noriyuki, Kita, Noriko, Kitajima, Kouki, Kleine, Thorsten, Krot, Sasha, Liu, Ming-Chang, Masuda, Yuki, Moynier, Frédéric, Nguyen, Ann, Nittler, Larry, Pack, Andreas, Park, Changkun, Piani, Laurette, Qin, Liping, Rocco, Tommaso, Russell, Sara, Sakamoto, Naoya, Schönbächler, Maria, Tafla, Lauren, Tang, Haolan, Terada, Kentaro, Usui, Tomohiro, Wada, Sohei, Wadhwa, Meenakshi, Walker, Richard, Yamashita, Katsuyuki, Yin, Qing-Zhu, Yoneda, Shigekazu, Young, Edward, 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, and Yurimoto, Hisayoshi

Abstract

Characterization of the elemental distribution of samples with rough surfaces has been strongly desired for the analysis of various natural and artificial materials. Particularly for pristine and rare analytes with micrometer sizes embedded on specimen surfaces, non-invasive and matrix effect-free analysis is required without surface polishing treatment. To satisfy these requirements, we proposed a new method employing the sequential combination of two imaging modalities, i.e., microenergy-dispersive X-ray fluorescence (micro-XRF) and Raman micro-spectroscopy. The applicability of the developed method is tested by the quantitative analysis of cation composition in micrometer-sized carbonate grains on the surfaces of intact particles sampled directly from the asteroid Ryugu. The first step of micro-XRF imaging enabled a quick search for the sparsely scattered and micrometer-sized carbonates by the codistributions of Ca2+ and Mn2+ on the Mg2+- and Fe2+-rich phyllosilicate matrix. The following step of Raman micro-spectroscopy probed the carbonate grains and analyzed their cation composition (Ca2+, Mg2+, and Fe2+ + Mn2+) in a matrix effect-free manner via the systematic Raman shifts of the lattice modes. The carbonates were basically assigned to ferroan dolomite bearing a considerable amount of Fe2+ + Mn2+ at around 10 atom %. These results are in good accordance with the assignments reported by scanning electron microscopy-energy-dispersive X-ray spectroscopy, where the thin-sectioned and surface-polished Ryugu particles were applicable. The proposed method requires neither sectioning nor surface polishing; hence, it can be applied to the remote sensing apparatus on spacecrafts and planetary rovers. Furthermore, the non-invasive and matrix effect-free characterization will provide a reliable analytical tool for quantitative analysis of the elemental distribution on the samples with surface roughness and chemical heterogeneity at a micrometer scale, such as art paintings, traditional crafts with decorated shapes, as well as sands and rocks with complex morphologies in nature.

Published
2024

13. Water circulation in Ryugu asteroid affected the distribution of nucleosynthetic isotope anomalies in returned sample.

Author

Yokoyama, Tetsuya, Wadhwa, Meenakshi, Iizuka, Tsuyoshi, Rai, Vinai, Gautam, Ikshu, Hibiya, Yuki, Masuda, Yuki, Haba, Makiko, Fukai, Ryota, Hines, Rebekah, Phelan, Nicole, Abe, Yoshinari, Aléon, Jérôme, Alexander, Conel, Amari, Sachiko, Amelin, Yuri, Bajo, Ken-Ichi, Bizzarro, Martin, Bouvier, Audrey, Carlson, Richard, Chaussidon, Marc, Choi, Byeon-Gak, Dauphas, Nicolas, Davis, Andrew, Di Rocco, Tommaso, Fujiya, Wataru, Hidaka, Hiroshi, Homma, Hisashi, Hoppe, Peter, Huss, Gary, Ichida, Kiyohiro, Ireland, Trevor, Ishikawa, Akira, Itoh, Shoichi, Kawasaki, Noriyuki, Kita, Noriko, Kitajima, Koki, Kleine, Thorsten, Komatani, Shintaro, Krot, Alexander, Liu, Ming-Chang, McKeegan, Kevin, Morita, Mayu, Motomura, Kazuko, Moynier, Frédéric, Nakai, Izumi, Nagashima, Kazuhide, Nguyen, Ann, Nittler, Larry, Onose, Morihiko, Pack, Andreas, Park, Changkun, Piani, Laurette, Qin, Liping, Russell, Sara, Sakamoto, Naoya, Schönbächler, Maria, Tafla, Lauren, Tang, Haolan, Terada, Kentaro, Terada, Yasuko, Usui, Tomohiro, Wada, Sohei, Walker, Richard, Yamashita, Katsuyuki, Yoneda, Shigekazu, Young, Edward, 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, and Yin, Qing-Zhu

Abstract

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 54Cr-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 [Formula: see text] 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.

Published
2023

14. Abundant presolar grains and primordial organics preserved in carbon-rich exogenous clasts in asteroid Ryugu.

Author

Nguyen, Ann, Mane, Prajkta, Keller, Lindsay, Piani, Laurette, Abe, Yoshinari, Aléon, Jérôme, Alexander, Conel, Amari, Sachiko, Amelin, Yuri, Bajo, Ken-Ichi, Bizzarro, Martin, Bouvier, Audrey, Carlson, Richard, Chaussidon, Marc, Choi, Byeon-Gak, Dauphas, Nicolas, Davis, Andrew, Di Rocco, Tommaso, Fujiya, Wataru, Fukai, Ryota, Gautam, Ikshu, Haba, Makiko, Hibiya, Yuki, Hidaka, Hiroshi, Homma, Hisashi, Hoppe, Peter, Huss, Gary, Ichida, Kiyohiro, Iizuka, Tsuyoshi, Ireland, Trevor, Ishikawa, Akira, Itoh, Shoichi, Kawasaki, Noriyuki, Kita, Noriko, Kitajima, Kouki, Kleine, Thorsten, Komatani, Shintaro, Krot, Alexander, Liu, Ming-Chang, Masuda, Yuki, McKeegan, Kevin, Morita, Mayu, Motomura, Kazuko, Moynier, Frédéric, Nakai, Izumi, Nagashima, Kazuhide, Nesvorný, David, Nittler, Larry, Onose, Morihiko, Pack, Andreas, Park, Changkun, Qin, Liping, Russell, Sara, Sakamoto, Naoya, Schönbächler, Maria, Tafla, Lauren, Tang, Haolan, Terada, Kentaro, Terada, Yasuko, Usui, Tomohiro, Wada, Sohei, Wadhwa, Meenakshi, Walker, Richard, Yamashita, Katsuyuki, Yokoyama, Tetsuya, Yoneda, Shigekazu, Young, Edward, 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, and Yin, Qing-Zhu

Subjects
Carbon, Solar System, Meteoroids, Silicates
Abstract

Preliminary analyses of asteroid Ryugu samples show kinship to aqueously altered CI (Ivuna-type) chondrites, suggesting similar origins. We report identification of C-rich, particularly primitive clasts in Ryugu samples that contain preserved presolar silicate grains and exceptional abundances of presolar SiC and isotopically anomalous organic matter. The high presolar silicate abundance (104 ppm) indicates that the clast escaped extensive alteration. The 5 to 10 times higher abundances of presolar SiC (~235 ppm), N-rich organic matter, organics with N isotopic anomalies (1.2%), and organics with C isotopic anomalies (0.2%) in the primitive clasts compared to bulk Ryugu suggest that the clasts formed in a unique part of the protoplanetary disk enriched in presolar materials. These clasts likely represent previously unsampled outer solar system material that accreted onto Ryugu after aqueous alteration ceased, consistent with Ryugus rubble pile origin.

Published
2023

17. Presolar stardust in asteroid Ryugu

Author

Barosch, Jens, Nittler, Larry R., Wang, Jianhua, Alexander, Conel M. O'D., De Gregorio, Bradley T., Engrand, Cécile, Kebukawa, Yoko, Nagashima, Kazuhide, Stroud, Rhonda M., Yabuta, Hikaru, Abe, Yoshinari, Aléon, Jérôme, Amari, Sachiko, Amelin, Yuri, Bajo, Ken-ichi, Bejach, Laure, Bizzarro, Martin, Bonal, Lydie, Bouvier, Audrey, Carlson, Richard W., Chaussidon, Marc, Choi, Byeon-Gak, Cody, George D., Dartois, Emmanuel, Dauphas, Nicolas, Davis, Andrew M., Dazzi, Alexandre, Deniset-Besseau, Ariane, Di Rocco, Tommaso, Duprat, Jean, Fujiya, Wataru, Fukai, Ryota, Gautam, Ikshu, Haba, Makiko K., Hashiguchi, Minako, Hibiya, Yuki, Hidaka, Hiroshi, Homma, Hisashi, Hoppe, Peter, Huss, Gary R., Ichida, Kiyohiro, Iizuka, Tsuyoshi, Ireland, Trevor R., Ishikawa, Akira, Ito, Motoo, Itoh, Shoichi, Kamide, Kanami, Kawasaki, Noriyuki, Kilcoyne, A. L. David, Kita, Noriko T., Kitajima, Kouki, Kleine, Thorsten, Komatani, Shintaro, Komatsu, Mutsumi, Krot, Alexander N., Liu, Ming-Chang, Martins, Zita, Masuda, Yuki, Mathurin, Jérémie, McKeegan, Kevin D., Montagnac, Gilles, Morita, Mayu, Mostefaoui, Smail, Motomura, Kazuko, Moynier, Frédéric, Nakai, Izumi, Nguyen, Ann N., Ohigashi, Takuji, Okumura, Taiga, Onose, Morihiko, Pack, Andreas, Park, Changkun, Piani, Laurette, Qin, Liping, Quirico, Eric, Remusat, Laurent, Russell, Sara S., Sakamoto, Naoya, Sandford, Scott A., Schönbächler, Maria, Shigenaka, Miho, Suga, Hiroki, Tafla, Lauren, Takahashi, Yoshio, Takeichi, Yasuo, Tamenori, Yusuke, Tang, Haolan, Terada, Kentaro, Terada, Yasuko, Usui, Tomohiro, Verdier-Paoletti, Maximilien, Wada, Sohei, Wadhwa, Meenakshi, Wakabayashi, Daisuke, Walker, Richard J., Yamashita, Katsuyuki, Yamashita, Shohei, Yin, Qing-Zhu, Yokoyama, Tetsuya, Yoneda, Shigekazu, Young, Edward D., Yui, Hiroharu, Zhang, Ai-Cheng, Abe, Masanao, Miyazaki, Akiko, Nakato, Aiko, Nakazawa, Satoru, Nishimura, Masahiro, Okada, Tatsuaki, Saiki, Takanao, Tanaka, Satoshi, Terui, Fuyuto, Tsuda, Yuichi, Watanabe, Sei-ichiro, Yada, Toru, Yogata, Kasumi, Yoshikawa, Makoto, Nakamura, Tomoki, Naraoka, Hiroshi, Noguchi, Takaaki, Okazaki, Ryuji, Sakamoto, Kanako, Tachibana, Shogo, and Yurimoto, Hisayoshi

Subjects
Astrophysics - Earth and Planetary Astrophysics, Astrophysics - Solar and Stellar Astrophysics
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$^{+4.7}_{-2.6}$ ppm for O-anomalous grains, 25$^{+6}_{-5}$ ppm for SiC grains and 11$^{+5}_{-3}$ 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 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 $^{+7}_{-6}$ ppm SiC and 9.0$^{+5.3}_{-4.6}$ 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., Comment: 12 pages, 3 figures, 2 tables. Published in ApJL

Published
2022
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18. Effect of Groundwater Filtering on Clogging of Recharge Well

Author

Hayashi, Hidehiko, Ishikawa, Akira, Kohsaka, Nobuaki, di Prisco, Marco, Series Editor, Chen, Sheng-Hong, Series Editor, Vayas, Ioannis, Series Editor, Kumar Shukla, Sanjay, Series Editor, Sharma, Anuj, Series Editor, Kumar, Nagesh, Series Editor, Wang, Chien Ming, Series Editor, Cui, Zhen-Dong, Series Editor, Hazarika, Hemanta, editor, Haigh, Stuart Kenneth, editor, Chaudhary, Babloo, editor, Murai, Masanori, editor, and Manandhar, Suman, editor

Published
2024
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19. Oxygen isotopes of anhydrous primary minerals show kinship between asteroid Ryugu and comet 81P/Wild2

Author

Kawasaki, Noriyuki, Nagashima, Kazuhide, Sakamoto, Naoya, Matsumoto, Toru, Bajo, Ken-ichi, Wada, Sohei, Igami, Yohei, Miyake, Akira, Noguchi, Takaaki, Yamamoto, Daiki, Russell, Sara S, Abe, Yoshinari, Aléon, Jérôme, Alexander, Conel M O’D, Amari, Sachiko, Amelin, Yuri, 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, Kita, Noriko T, Kitajima, Kouki, Kleine, Thorsten, Komatani, Shintaro, Krot, Alexander N, Liu, Ming-Chang, Masuda, Yuki, McKeegan, Kevin D, Morita, Mayu, Motomura, Kazuko, Moynier, Frédéric, Nakai, Izumi, Nguyen, Ann, Nittler, Larry, Onose, Morihiko, Pack, Andreas, Park, Changkun, Piani, Laurette, Qin, Liping, Schönbächler, Maria, Tafla, Lauren, Tang, Haolan, Terada, Kentaro, Terada, Yasuko, Usui, Tomohiro, Wadhwa, Meenakshi, Walker, Richard J, Yamashita, Katsuyuki, Yin, Qing-Zhu, Yokoyama, Tetsuya, Yoneda, Shigekazu, Young, Edward D, Yui, Hiroharu, Zhang, Ai-Cheng, Nakamura, Tomoki, Naraoka, Hiroshi, 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, and Yurimoto, Hisayoshi

Subjects
Earth Sciences, Physical Sciences, Space Sciences, Geology, Prevention
Abstract

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: 16O-rich (associated with refractory inclusions) and 16O-poor (associated with chondrules). Both the 16O-rich and 16O-poor minerals probably formed in the inner solar protoplanetary disk and were subsequently transported outward. The abundance ratios of the 16O-rich to 16O-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.

Published
2022

20. Ryugus nucleosynthetic heritage from the outskirts of the Solar System.

Author

Hopp, Timo, Dauphas, Nicolas, Abe, Yoshinari, Aléon, Jérôme, OD Alexander, Conel, Amari, Sachiko, Amelin, Yuri, Bajo, Ken-Ichi, Bizzarro, Martin, Bouvier, Audrey, Carlson, Richard, Chaussidon, Marc, Choi, Byeon-Gak, Davis, Andrew, Di Rocco, Tommaso, Fujiya, Wataru, Fukai, Ryota, Gautam, Ikshu, Haba, Makiko, Hibiya, Yuki, Hidaka, Hiroshi, Homma, Hisashi, Hoppe, Peter, Huss, Gary, Ichida, Kiyohiro, Iizuka, Tsuyoshi, Ireland, Trevor, Ishikawa, Akira, Ito, Motoo, Itoh, Shoichi, Kawasaki, Noriyuki, Kita, Noriko, Kitajima, Kouki, Kleine, Thorsten, Komatani, Shintaro, Krot, Alexander, Liu, Ming-Chang, Masuda, Yuki, McKeegan, Kevin, Morita, Mayu, Motomura, Kazuko, Moynier, Frédéric, Nakai, Izumi, Nagashima, Kazuhide, Nesvorný, David, Nguyen, Ann, Nittler, Larry, Onose, Morihiko, Pack, Andreas, Park, Changkun, Piani, Laurette, Qin, Liping, Russell, Sara, Sakamoto, Naoya, Schönbächler, Maria, Tafla, Lauren, Tang, Haolan, Terada, Kentaro, Terada, Yasuko, Usui, Tomohiro, Wada, Sohei, Wadhwa, Meenakshi, Walker, Richard, Yamashita, Katsuyuki, Yin, Qing-Zhu, Yokoyama, Tetsuya, Yoneda, Shigekazu, Young, Edward, 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, and Yurimoto, Hisayoshi

Abstract

Little is known about the origin of the spectral diversity of asteroids and what it says about conditions in the protoplanetary disk. Here, we show that samples returned from Cb-type asteroid Ryugu have Fe isotopic anomalies indistinguishable from Ivuna-type (CI) chondrites, which are distinct from all other carbonaceous chondrites. Iron isotopes, therefore, demonstrate that Ryugu and CI chondrites formed in a reservoir that was different from the source regions of other carbonaceous asteroids. Growth and migration of the giant planets destabilized nearby planetesimals and ejected some inward to be implanted into the Main Belt. In this framework, most carbonaceous chondrites may have originated from regions around the birthplaces of Jupiter and Saturn, while the distinct isotopic composition of CI chondrites and Ryugu may reflect their formation further away in the disk, owing their presence in the inner Solar System to excitation by Uranus and Neptune.

Published
2022

25. Pyrrhotites in asteroid 162173 Ryugu: Records of the initial changes on their surfaces with aqueous alteration

Author

Yui, Hiroharu, Urashima, Shu-hei, Onose, Morihiko, Morita, Mayu, Komatani, Shintaro, Nakai, Izumi, Abe, Yoshinari, Terada, Yasuko, Homma, Hisashi, Motomura, Kazuko, Ichida, Kiyohiro, Yokoyama, Tetsuya, Nagashima, Kazuhide, Aléon, Jérôme, M. O’D. Alexander, Conel, Amari, Sachiko, Amelin, Yuri, Bajo, Ken-ichi, Bizzarro, Martin, Bouvier, Audrey, Carlson, Richard W., Chaussidon, Marc, Choi, Byeon-Gak, Dauphas, Nicolas, Davis, Andrew M., Fujiya, Wataru, Fukai, Ryota, Gautam, Ikshu, Haba, Makiko K., Hibiya, Yuki, Hidaka, Hiroshi, Hoppe, Peter, Huss, Gary R., Iizuka, Tsuyoshi, Ireland, Trevor R., Ishikawa, Akira, Itoh, Shoichi, Kawasaki, Noriyuki, Kita, Noriko T., Kitajima, Kouki, Kleine, Thorsten, Krot, Sasha, Liu, Ming-Chang, Masuda, Yuki, Moynier, Frédéric, Nguyen, Ann, Nittler, Larry, Pack, Andreas, Park, Changkun, Piani, Laurette, Qin, Liping, Di Rocco, Tommaso, Russell, Sara S., Sakamoto, Naoya, Schönbächler, Maria, Tafla, Lauren, Tang, Haolan, Terada, Kentaro, Usui, Tomohiro, Wada, Sohei, Wadhwa, Meenakshi, Walker, Richard J., Yamashita, Katsuyuki, Yin, Qing-Zhu, Yoneda, Shigekazu, Young, Edward D., 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, and Yurimoto, Hisayoshi

Published
2024
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30. Pervasive aqueous alteration in the early Solar System revealed by potassium isotopic variations in Ryugu samples and carbonaceous chondrites

Author

Hu, Yan, Moynier, Frédéric, Dai, Wei, Paquet, Marine, Yokoyama, Tetsuya, Abe, Yoshinari, Aléon, Jérôme, Alexander, Conel M. O'D., 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, Itoh, Shoichi, Kawasaki, Noriyuki, Kita, Noriko T., Kitajima, Koki, Kleine, Thorsten, Komatani, Shintaro, Krot, Alexander N., Liu, Ming-Chang, Masuda, Yuki, Morita, Mayu, Motomura, Kazuko, Nakai, Izumi, Nagashima, Kazuhide, Nesvorný, David, Nguyen, Ann, Nittler, Larry, Onose, Morihiko, Pack, Andreas, Park, Changkun, Piani, Laurette, Qin, Liping, Russell, Sara S., Sakamoto, Naoya, Schönbächler, 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, and Yurimoto, Hisayoshi

Published
2024
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39. Subclassification of pT3 upper tract urothelial carcinoma: a multicenter retrospective study

Author

Yamada, Yukio, Nakagawa, Tohru, Miyakawa, Jimpei, Kawai, Taketo, Taguchi, Satoru, Tabata, Mariko, Kaneko, Tomoyuki, Ishikawa, Akira, Miyazaki, Hideyo, Kondo, Yasushi, Matsumoto, Akihiko, Naito, Akihiro, Hikatsu, Masahiro, Fujii, Yoichi, Akiyama, Yoshiyuki, Yamada, Yuta, Sato, Yusuke, Nomiya, Akira, Yamada, Daisuke, Murata, Taro, Suzuki, Motofumi, Enomoto, Yutaka, Nishimatsu, Hiroaki, Takeuchi, Takumi, Tanaka, Yoshinori, and Kume, Haruki

Published
2023
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40. Contribution of Ryugu-like material to Earth’s volatile inventory by Cu and Zn isotopic analysis

Author

Paquet, Marine, Moynier, Frederic, Yokoyama, Tetsuya, Dai, Wei, Hu, Yan, Abe, Yoshinari, Aléon, Jérôme, 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, Nesvorný, David, Nguyen, Ann N., Nittler, Larry, Onose, Morihiko, Pack, Andreas, Park, Changkun, Piani, Laurette, Qin, Liping, Russell, Sara S., Sakamoto, Naoya, Schönbächler, 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, and Yurimoto, Hisayoshi

Published
2023
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46. Classification of Patients Based on Dyspnea and Desaturation During Exercise in Interstitial Lung Disease.

Author

Otake, Kohei, Misu, Shogo, Yamamoto, Akio, Yamaguchi, Takumi, Nagatani, Chisato, Sakai, Hideki, Kaneko, Masahiro, Ishikawa, Akira, and Tomioka, Hiromi

Abstract

Background: Dyspnea and desaturation during exercise are essential assessment items for pulmonary rehabilitation. Characterizing patients using these 2 factors may be important for providing more effective pulmonary rehabilitation. This study aimed to categorize subjects with interstitial lung disease (ILD) using dyspnea and desaturation at the end of the 6-min walk test (6MWT). Methods: This was a retrospective study including 230 stable subjects with ILD who underwent 6MWT in our out-patient department at a general hospital in Japan. The modified Borg scale and oxygen saturation determined by SpO2 at the end of the 6MWT were used for cluster analysis using the k-means method with k = 4. Results: Subjects were classified into 4 characteristic clusters. SpO2 at the end of the 6MWT was lower in cluster 4 (80.5 ± 3.0%) than in clusters 1 (94.3 ± 2.0%), 2 (94.3 ± 1.9%), and 3 (87.9 ± 1.8%) and was lower in cluster 3 than in clusters 1 and 2. The modified Borg scale score at the end of the 6MWT was higher in clusters 2 (4 [3–8]), 3 (3 [0–9]), and 4 (4 [0–7]) than in cluster 1 (0.5 [0–2.0]) and was higher in cluster 2 than in cluster 3. Conclusions: Subjects with ILD were classified into 4 characteristic clusters using dyspnea and SpO2 at the end of the 6MWT. The 4 clusters are characterized as follows: Cluster 1 had mild desaturation and mild dyspnea; cluster 2 had mild desaturation and severe dyspnea; cluster 3 had both moderate desaturation and dyspnea, and cluster 4 had both severe desaturation and dyspnea. These classification data offer insight for individualized pulmonary rehabilitation for patients with ILD. [ABSTRACT FROM AUTHOR]

Published
2025
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47. Genetic Diversity, Runs of Homozygosity, and Selection Signatures in Native Japanese Chickens: Insights from Single-Nucleotide Polymorphisms.

Author

Velasco, Vanessa V., Tsudzuki, Masaoki, Hashimoto, Norikazu, Goto, Naoki, and Ishikawa, Akira

Subjects
GENETIC variation, SINGLE nucleotide polymorphisms, POULTRY breeding, CHROMOSOMES, DNA sequencing, CHICKEN breeds
Abstract

Simple Summary: This study assessed genetic diversity, runs of homozygosity (ROH), and selection signatures in 11 populations of seven native Japanese chicken breeds and three foreign chicken breeds using 11,493 single nucleotide polymorphisms (SNPs) from restriction-site-associated DNA sequencing. Six Japanese chicken populations showed moderate diversity, with one breed exhibiting higher genetic diversity. Population analyses grouped the 11 populations into four clusters, revealing generally lower ROH values in Japanese populations than in foreign populations. ROH and Fst analyses identified seven SNPs within the selection signatures, five of which were candidate genetic variants for fear-related behavior. Understanding genetic diversity, runs of homozygosity (ROH), and selection signatures is critical for the conservation and breeding management of native Japanese chickens. In this study, genetic diversity, ROH, and selection signatures in 11 populations of seven native Japanese breeds and three foreign breeds with different genetic and behavioral backgrounds were investigated using 11,493 SNPs identified through restriction-site-associated DNA sequencing. The Oh-Shamo (OSM), an aggressive cockfighting breed, exhibited the highest genetic diversity. Six native Japanese breeds, Ingie (IG), Ryujin-Jidori (RYU), Tosa-Jidori (TJI), Tosa-Kukin (TKU), Nagoya (NAG), and Ukkokei (UK), showed intermediate levels of genetic diversity and ROH. Population analyses grouped the 11 populations into four distinct clusters: (1) five populations comprising three foreign breeds (the Fayoumi inbred line, closed-colony G line of White Leghorn, commercial T line of WL, and White Plymouth Rock) and the IG Japanese breed; (2) OSM and two old Jidori breeds (RYU and TJI); (3) TKU and UK; and (4) the meat-type Nagoya breed. ROH and Fst analyses identified seven SNPs on chromosomes 13, 17, 20, 24, and 26, five of which were candidate genetic variants for fear-related behavior. These findings provide insights into genetic diversity and conserved genomic segments valuable for breeding and conservation in Japanese chicken breeds. [ABSTRACT FROM AUTHOR]

Published
2024
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48. A Proton Pump Inhibitor Independently Elevates Gastrin Levels as a Marker for Metachronous Gastric Cancer After Endoscopic Submucosal Dissection.

Author

Teshima, Hajime, Takigawa, Hidehiko, Kotachi, Takahiro, Tsuboi, Akiyoshi, Tanaka, Hidenori, Yamashita, Ken, Kishida, Yoshihiro, Urabe, Yuji, Kuwai, Toshio, Ishikawa, Akira, and Oka, Shiro

Subjects
STOMACH cancer, PROTON pump inhibitors, BIOMARKERS, RECEIVER operating characteristic curves, HELICOBACTER pylori
Abstract

Background and Objective: Serum markers such as gastrin and pepsinogen are useful for stratifying gastric cancer risk. However, their utility in predicting metachronous gastric cancer after endoscopic submucosal dissection (ESD) in patients with gastric cancer after Helicobacter pylori eradication (GCAE) is unclear. This study aimed to clarify predictive factors for metachronous gastric cancer after ESD with a focus on serum markers. Methods: A retrospective analysis was conducted on 197 patients with 224 GCAE lesions who underwent ESD at Hiroshima University Hospital between April 2010 and December 2019. In total, 63 patients with 74 differentiated-type lesions were classified into metachronous gastric cancer (MG) and non-metachronous gastric cancer (NMG) groups, excluding proton pump inhibitor (PPI) users, female patients, and undifferentiated-type cases. The predictive value of serum markers was assessed using ROC curve analysis, and their association with carcinogenesis was evaluated using multiple logistic regression. Furthermore, the incidence of MG was compared between long-term PPI users and non-users. Results: ROC analysis revealed that serum gastrin had the highest discriminative ability for MG (AUC 0.77, cut-off 99 pg/mL, sensitivity 61.6%, and specificity 80.0%). Severe mucosal atrophy and high gastrin levels were significantly more common in the MG group and were independent predictors (p < 0.01). Although serum gastrin levels were significantly elevated in PPI users, no increased risk of MG was observed. Conclusions: In addition to severe mucosal atrophy, PPI-independent elevated serum gastrin levels may be associated with an increased risk of MG after ESD. Serum gastrin may serve as a valuable marker for post-ESD cancer surveillance in GCAE patients. [ABSTRACT FROM AUTHOR]

Published
2024
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