文献一覧: Hideto Yoshida (著者)

12 0 0 0 OA Ryugu particles found outside the Hayabusa2 sample container

著者: Aiko Nakato Shiori Inada Shizuho Furuya Masahiro Nishimura Toru Yada Masanao Abe Tomohiro Usui Hideto Yoshida Takashi Mikouchi Kanako Sakamoto Hajime Yano Yayoi N. Miura Yoshinori Takano Shinji Yamanouchi Ryuji Okazaki Hirotaka Sawada Shogo Tachibana
出版者: GEOCHEMICAL SOCIETY OF JAPAN
雑誌: GEOCHEMICAL JOURNAL (ISSN:00167002)
巻号頁・発行日: pp.GJ22017, (Released:2022-10-21)
被引用文献数: 13

The Hayabusa2 spacecraft explored C-type near-Earth asteroid (162173) Ryugu and returned asteroidal materials, collected during two touchdown operations, to the Earth as the first sample from carbonaceous-type asteroid. The sample container, in which ~5 g of Ryugu sample was enclosed, was safely opened in the clean chamber system with no severe exposure to the terrestrial atmosphere. In the course of preparation operation of the sample container, two dark-colored millimeter- to sub-millimeter-sized particles were found outside the sealing part of the sample container. Because they look similar to the Ryugu particles inside the sample container, the particles were named as Q particles (Q from questionable). In this study, we investigated Q particles (Q001 and Q002) mineralogically and petrographically to compare them with potential contaminants (the ablator material of the reentry capsule and fine sand particles at the capsule landing site), Ryugu sample, and CI chondrites. The Q particles show close resemblance to Ryugu sample and CI chondrites, but have no evidence of terrestrial weathering that CI chondrites experienced. We therefore conclude that the Q particles are originated from Ryugu and were expelled from the sample catcher (sample storage canister) in space prior to the enclosure operation of the sample catcher in the sample container. The most likely scenario is that the Q particles escaped from the sample catcher during the retrieval of the sample collection reflector, which was the necessary operation for the sample container closing.

2023-03-24 09:53:31
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1 0 0 0 OA Ryugu particles found outside the Hayabusa2 sample container

著者: Aiko Nakato Shiori Inada Shizuho Furuya Masahiro Nishimura Toru Yada Masanao Abe Tomohiro Usui Hideto Yoshida Takashi Mikouchi Kanako Sakamoto Hajime Yano Yayoi N. Miura Yoshinori Takano Shinji Yamanouchi Ryuji Okazaki Hirotaka Sawada Shogo Tachibana
出版者: GEOCHEMICAL SOCIETY OF JAPAN
雑誌: GEOCHEMICAL JOURNAL (ISSN:00167002)
巻号頁・発行日: vol.56, no.6, pp.197-222, 2022 (Released:2022-12-16)
参考文献数: 60
被引用文献数: 13

2023-01-12 21:48:56
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1 0 0 0 Enhancement of the Classification Performance of Electrical Field-Flow Fractionation Using Horizontal Electrophoresis

著者: Tetsuya Yamamoto Takahisa Tatekawa Kunihiro Fukui Hideto Yoshida
出版者: The Society of Chemical Engineers, Japan
雑誌: JOURNAL OF CHEMICAL ENGINEERING OF JAPAN (ISSN:00219592)
巻号頁・発行日: vol.44, no.6, pp.398-404, 2011-06-20 (Released:2011-06-20)
参考文献数: 12
被引用文献数: 5 5

The purpose of the present study was to enhance the classification performance of electrical field-flow fractionation (EFFF). In recent research by this group, the surface potential of silica particles treated with a bead mill displayed size dependency—smaller particles had a more negative zeta potential. This phenomenon and the EFFF system were used to classify the particles, with the bottom and top plates of the EFFF channel serving as negative and positive electrodes, respectively.In the present study, improvements to the EFFF channel were carried out to enhance classification accuracy. Walls of deionized water were utilized to prevent particles from contacting the electrodes. Because vertical electrophoresis led to the disturbance of particle trajectories in the channel by gravitational sedimentation, horizontal electrophoresis was applied. Furthermore, hydrodynamic force was induced in the channel creating differing linear velocities of the slurry and the water at the inlet. As a result, 200-nm particles could be classified at an applied voltage of 5 V with high accuracy when compared with the previous method that used vertical electrophoresis.

2020-07-31 13:48:03
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1 0 0 0 OA Ingestion of hyaluronans (molecular weights 800 k and 300 k) improves dry skin conditions: a randomized, double blind, controlled study

著者: Chinatsu Kawada Takushi Yoshida Hideto Yoshida Wakako Sakamoto Wataru Odanaka Toshihide Sato Takeshi Yamasaki Tomoyuki Kanemitsu Yasunobu Masuda Osamu Urushibata
出版者: 日本酸化ストレス学会
雑誌: Journal of Clinical Biochemistry and Nutrition (ISSN:09120009)
巻号頁・発行日: vol.56, no.1, pp.66-73, 2015 (Released:2015-01-01)
参考文献数: 36
被引用文献数: 1 16

Hyaluronan (HA) has been increasingly used as a dietary supplement to improve the skin. However, the effect of ingested HA may depend on its molecular weight (MW) because its physiological activities in the body vary with its MW. In this study, we examined the effects of ingested HA with varying MW on the skin. In this randomized, double blind, placebo controlled study, 61 subjects with dry skin received oral HA (120 mg/day), of MWs 800 k and 300 k or placebo, for 6 weeks. The skin moisture contents of the first two groups increased more than those of the placebo group during the ingestion period. In addition, group HA 300 k exhibited significant improvements in skin moisture content 2 weeks after ingestion ended compared with the placebo group. A questionnaire survey about subjective facial aging symptoms showed that the HA treated groups exhibited significantly improved the skin condition compared with the placebo treated group. Furthermore, dermatologists objectively evaluated the clinical symptoms of the facial and whole body skin, showing that no adverse events were related to daily ingestion of HA. This study shows that both of ingesting HAs (MWs 800 k and 300 k) improved the skin condition by increasing the moisture content.

2015-05-02 18:15:38
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