著者

Yudai Okuyama Yuta Kato

出版者

National Museum of Nature and Sciece (National Science Museum, Tokyo)

雑誌

国立科学博物館研究報告B類(植物学) (ISSN:18819060)

巻号頁・発行日

vol.48, no.4, pp.133-139, 2022-11-22 (Released:2022-11-22)

参考文献数

11

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To obtain a better understanding of the floral traits of sect. Heterotropa (genus Asarum, Aristolochiaceae), we conducted a detailed microscopic examination of the surface of the calyx, the floral part best representing the diversity of the lineage. The surface structures were highly variable among Heterotropa species, with remarkable variations in trichome morphology on the adaxial surface of the calyx lobes. Four types of trichome were identified on the calyx lobes, each of which was the sole type in most samples, although combinations of multiple types were occasionally seen. Variations were also found in the distribution of stomata on the surface of the calyx. Although the biological functions of the trichomes and stomata on the calyx are unclear, they may be related to pollination systems, e.g., through emission of the floral scents that are highly variable among Heterotropa species.

著者

Makoto Sugihara Kaori Mine Makito Futami Yuta Kato Tadaaki Arimura Masaya Yano Yosuke Takamiya Takashi Kuwano Shin-ichiro Miura

出版者

The Japanese Circulation Society

雑誌

Circulation Reports (ISSN:24340790)

巻号頁・発行日

vol.2, no.11, pp.682-690, 2020-11-10 (Released:2020-11-10)

参考文献数

21

被引用文献数

4

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Background:Drug-coated balloon strategies in endovascular therapy often result in severe dissection, so lesion preparation must be improved. We evaluated the efficacy of a gradual inflation method, termed “super slow inflation” (SSI), in preparing lesions to avoid severe dissections.Methods and Results:The association between balloon pressure and the dilatation of a model constricted vessel, as well as the load applied to the balloon surface, were determined using a burst leak detector for a quick inflation (QI; 1 atm/s) protocol and SSI (1 atm/20 s). A retrospective, single-center, non-randomized study evaluated differences in vessel dissection patterns after balloon angioplasty depending on inflation method in 81 consecutive patients (mean [±SD] age 74.6±9.2 years; 54 males) who underwent balloon angioplasty for de novo femoropopliteal lesions between January 2017 and March 2019. In the constricted vessel model, vessel dilatation increased gradually using SSI, with the maximum dilatation load being approximately 100 g lower for the SSI than QI protocol. In patients, the rate of severe vessel dissection was significantly lower in the SSI than non-SSI group (17.6% vs. 55.2%, respectively; P<0.001). Multivariate regression analysis revealed that SSI was an independent factor preventing severe dissection (odds ratio 0.18; 95% confidence interval 0.06–0.53; P=0.002).Conclusions:SSI is a gentle and effective method for the preparation of femoropopliteal lesions to reduce the incidence of severe angiographic dissection when using drug-coated balloons.

著者

Ikuya Yamada Atsushi Tanaka Seiji Oda Yuichi Okazaki Fumito Toda Yuta Kato Yuta Kizawa Masaya Oshita Manami Goto Amane Morimura Asuka Ochi Kaoru Toda Wencong Wang Hajime Yamamoto Hidekazu Ikeno Shunsuke Yagi

出版者

The Japan Institute of Metals and Materials

雑誌

MATERIALS TRANSACTIONS (ISSN:13459678)

巻号頁・発行日

vol.64, no.9, pp.2097-2104, 2023-09-01 (Released:2023-08-25)

参考文献数

37

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Chemical substitution is an effective way to improve electrocatalytic properties in transition metal oxides. We investigate the synergistic effect between Fe4+ and Co4+ ions on the catalytic activity for oxygen evolution reaction (OER) in the Fe–Co-mixed perovskite oxide CaFe1−xCoxO3. The OER activity of CaFe1−xCoxO3 is substantially increased by small amounts of Co (Fe) doping into CaFeO3 (CaCoO3), leading to the superiority compared to the pure Fe and Co perovskite oxides. The x dependences of the OER overpotential and specific activity for CaFe1−xCoxO3 (0.05 ≦ x ≦ 0.95) are expressed by constant offset from the weighted average between CaFeO3 and CaCoO3, which can be interpreted to be the synergistic effect between Fe4+ and Co4+ ions on OER activity. The absence of the optimum x for the highest activity for CaFe1−xCoxO3 contrasts with the volcano-like plots reported in various mixed-metal oxides. First-principle calculations using the special quasirandom structure models on CaFe1−xCoxO3 (x = 0.03–0.5) demonstrate that about half the amount of Fe4+ is electronically activated to possess smaller charge-transfer energies, corroborating the enhancement of catalytic activity in CaFe1−xCoxO3. These findings provide new insight into the synergistic effects in complex transition metal oxide catalysts.

著者

Ikuya Yamada Yuta Kato Hiroshi Nakajima Hidekazu Ikeno Shigeo Mori Shogo Kawaguchi

出版者

The Japan Institute of Metals and Materials

雑誌

MATERIALS TRANSACTIONS (ISSN:13459678)

巻号頁・発行日

pp.MT-MG2022005, (Released:2023-01-10)

参考文献数

37

被引用文献数

1

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A novel oxide YCu3Rh4O12 has been obtained using high-pressure and high-temperature conditions of 12 GPa and 1573 K. Electron diffraction and synchrotron X-ray powder diffraction data demonstrates that YCu3Rh4O12 crystallizes in a cubic AA′3B4O12-type quadruple perovskite structure. The valence state is estimated to be Y3+Cu3+3Rh3+4O12 by X-ray absorption spectroscopy. The electric resistivity and magnetization data prove that YCu3Rh4O12 is a diamagnetic insulator, which is expected from the electron configurations of Cu3+ (3d8, low spin, S = 0) and Rh3+ (4d6, low spin, S = 0) ions. The first-principle calculation displays the insulating band structure for YCu3Rh4O12. The valence state transition from Ca2+Cu2.8+3Rh3.4+4O12 to Y3+Cu3+3Rh3+4O12 indicates that the doped electrons by the substitution of Y3+ for Ca2+ are not simply injected to Cu and/or Rh ions, realizing unusual charge redistributions consisting of the simultaneous Cu oxidation (Cu2.8+ → Cu3+) and Rh reduction (Rh3.4+ → Rh3+).

著者

Makoto Sugihara Kaori Mine Makito Futami Yuta Kato Tadaaki Arimura Masaya Yano Yosuke Takamiya Takashi Kuwano Shin-ichiro Miura

出版者

The Japanese Circulation Society

雑誌

Circulation Reports (ISSN:24340790)

巻号頁・発行日

pp.CR-20-0095, (Released:2020-10-16)

参考文献数

21

被引用文献数

4

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Background:Drug-coated balloon strategies in endovascular therapy often result in severe dissection, so lesion preparation must be improved. We evaluated the efficacy of a gradual inflation method, termed “super slow inflation” (SSI), in preparing lesions to avoid severe dissections.Methods and Results:The association between balloon pressure and the dilatation of a model constricted vessel, as well as the load applied to the balloon surface, were determined using a burst leak detector for a quick inflation (QI; 1 atm/s) protocol and SSI (1 atm/20 s). A retrospective, single-center, non-randomized study evaluated differences in vessel dissection patterns after balloon angioplasty depending on inflation method in 81 consecutive patients (mean [±SD] age 74.6±9.2 years; 54 males) who underwent balloon angioplasty for de novo femoropopliteal lesions between January 2017 and March 2019. In the constricted vessel model, vessel dilatation increased gradually using SSI, with the maximum dilatation load being approximately 100 g lower for the SSI than QI protocol. In patients, the rate of severe vessel dissection was significantly lower in the SSI than non-SSI group (17.6% vs. 55.2%, respectively; P<0.001). Multivariate regression analysis revealed that SSI was an independent factor preventing severe dissection (odds ratio 0.18; 95% confidence interval 0.06–0.53; P=0.002).Conclusions:SSI is a gentle and effective method for the preparation of femoropopliteal lesions to reduce the incidence of severe angiographic dissection when using drug-coated balloons.

著者

Yuta Kato Rieko Kuhara Maki Sakamoto Reiichiro Tsuchiya Noboru Nagatani Yoshimune Nonomura

出版者

Japan Oil Chemists' Society

雑誌

Journal of Oleo Science (ISSN:13458957)

巻号頁・発行日

pp.ess20252, (Released:2021-01-15)

被引用文献数

4

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The Sara-sara feel, which means “a state in which things are not damp or sticky and feel dry,” is a preferred tactile sensation when people touch human skin, hair, clothing, and cosmetics. In this study, the Sara-sara feel was evaluated for silicone powder, cellulose powder, hydrophobized sericite powder, and various mixes of these powders. It was found that the highest Sara-sara feel score was achieved by the silicone powder. A multiple regression analysis showed that the Sara-sara feel was strongly correlated with a slippery feel. The relationship between certain physical properties, e.g., particle size distribution, and the slippery feel was analyzed to demonstrate how the subjects felt the slippery feel. It was observed that as the friction coefficient µk was reduced, most subjects strongly felt the slippery feel. This coefficient slightly decreased when the composition of spherical silicone powder increased, because the contact area between spherical particles is smaller than that between plate and amorphous particles.