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960 results on '"Kotani, Y."'

1. Element-specific field-induced spin reorientation and an unusual tetracritical point in MnCr2S4

Author

Yamamoto, Sh., Suwa, H., Kihara, T., Nomura, T., Kotani, Y., Nakamura, T., Skourski, Y., Zherlitsyn, S., Prodan, L., Tsurkan, V., Nojiri, H., Loidl, A., and Wosnitza, J.

Subjects
Condensed Matter - Strongly Correlated Electrons
Abstract

The ferrimagnetic spinel MnCr2S4 shows a variety of magnetic-field-induced phase transitions owing to bond frustration and strong spin-lattice coupling. However, the site-resolved magnetic properties at the respective field-induced phases in high magnetic fields remain elusive. Our soft x-ray magnetic circular dichroism studies up to 40 T directly evidence element-selective magnetic-moment reorientations in the field-induced phases. The complex magnetic structures are further supported by entropy changes extracted from magnetocaloric-effect measurements. Moreover, thermodynamic experiments reveal an unusual tetracritical point in the H-T phase diagram of MnCr2S4 due to strong spin-lattice coupling., Comment: 18 pages, 8 figures

Published
2020
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2. Bulk and element specific magnetism of the medium and high entropy Cantor-Wu alloys

Author

Billington, D., James, A. D. N., Harris-Lee, E. I., Lagos, D. A., ONeill, D., Tsuda, N., Toyoki, K., Kotani, Y., Nakamura, T., Bei, H., Mu, S., Samolyuk, G. D., Stocks, G. M., Duffy, J. A., Taylor, J. W., Giblin, S. R., and Dugdale, S. B.

Subjects
Condensed Matter - Strongly Correlated Electrons
Abstract

Magnetic Compton scattering, x-ray magnetic circular dichroism spectroscopy and bulk magnetometry measurements are performed on a set of medium (NiFeCo and NiFeCoCr) and high (NiFeCoCrPd and NiFeCoCrMn) entropy Cantor-Wu alloys. The bulk spin momentum densities determined by magnetic Compton scattering are remarkably isotropic, and this is a consequence of the smearing of the electronic structure by disorder scattering of the electron quasiparticles. Non-zero x-ray magnetic circular dichroism signals are observed for every element in every alloy indicating differences in the populations of the majority and minority spin states implying finite magnetic moments. When Cr is included in the solid solution, the Cr spin moment is unambiguously antiparallel to the total magnetic moment, while a vanishingly small magnetic moment is observed for Mn, despite calculations indicating a large moment. Some significant discrepancies are observed between the experimental bulk and surface magnetic moments. Despite the lack of quantitative agreement, the element specific surface magnetic moments seem to be qualitatively reasonable.

Published
2020
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8. Electronic structure of BaNi$_2$P$_2$ observed by angle-resolved photoemission spectroscopy

Author

Ideta, S., Yoshida, T., Nakajima, M., Malaeb, W., Kito, H., Eisaki, H., Iyo, A., Tomioka, Y., Ito, T., Kihou, K., Lee, C. H., Kotani, Y., Ono, K., Mo, S. K., Hussain, Z., Shen, Z. -X., Harima, H., Uchida, S., and Fujimori, A.

Subjects
Condensed Matter - Superconductivity
Abstract

We have performed an angle-resolved photoemission spectroscopy (ARPES) study of BaNi$_2$P$_2$ which shows a superconducting transition at $T_c$ $\sim$ 2.5 K. We observed hole and electron Fermi surfaces (FSs) around the Brillouin zone center and corner, respectively, and the shapes of the hole FSs dramatically changed with photon energy, indicating strong three-dimensionality. The observed FSs are consistent with band-structure calculation and de Haas-van Alphen measurements. The mass enhancement factors estimated in the normal state were $m^*$/$m_b$ $\leq$ 2, indicating weak electron correlation compared to typical iron-pnictide superconductors. An electron-like Fermi surface around the Z point was observed in contrast with BaNi$_2$As$_2$ and may be related to the higher $T_c$ of BaNi$_2$P$_2$., Comment: 6 figures

Published
2014
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9. Evidence for exclusion of the possibility of $d$-wave superconducting-gap symmetry in Ba-doped KFe$_2$As$_2$

Author

Ota, Y., Okazaki, K., Kotani, Y., Shimojima, T., Malaeb, W., Watanabe, S., Chen, C. -T., Kihou, K., Lee, C. H., Iyo, A., Eisaki, H., Saito, T., Fukazawa, H., Kohori, Y., and Shin, S.

Subjects
Condensed Matter - Superconductivity
Abstract

We have investigated the superconducting(SC)-gap anisotropy for several Ba-doped KFe$_2$As$_2$ samples using laser-based angle-resolved photoemission spectroscopy. We show that the SC-gap anisotropy and node positions drastically change with a small amount of Ba doping. Our results totally exclude a possibility of $d$-wave symmetry and strongly suggest that both spin and orbital fluctuations are important for the paring interaction in the Ba-doped K122.

Published
2013
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10. Evidence for a cos(4\varphi) Modulation of the Superconducting Energy Gap of Optimally Doped FeTe_{0.6}Se_{0.4} Single Crystals Using Laser Angle-Resolved Photoemission Spectroscopy

Author

Okazaki, K., Ito, Y., Ota, Y., Kotani, Y., Shimojima, T., Kiss, T., Watanabe, S., Chen, C. -T., Niitaka, S., Hanaguri, T., Takagi, H., Chainani, A., and Shin, S.

Subjects
Condensed Matter - Superconductivity, Condensed Matter - Materials Science, Condensed Matter - Strongly Correlated Electrons
Abstract

We study the superconducting(SC)-gap anisotropy of the \Gamma-centered hole Fermi surface in optimally doped FeTe_{0.6}Se_{0.4} (T_c = 14.5 K), using laser-excited angle-resolved photoemission spectroscopy (ARPES). We observe sharp superconducting coherence peaks at T = 2.5 K. In contrast to earlier ARPES studies but consistent with thermodynamic results, the momentum dependence shows a \cos(4\varphi) modulation of the SC-gap anisotropy. The observed SC-gap anisotropy strongly indicates that the pairing interaction is not a conventional phonon-mediated isotropic one. Instead, the results suggest the importance of second-nearest-neighbor electronic interactions between the iron sites in the framework of s_\pm-wave superconductivity., Comment: 5 pages, 3 figures, published in Physical Review Letters

Published
2012
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11. Dependence of carrier doping on the impurity potential in transition-metal-substituted FeAs-based superconductors

Author

Ideta, S., Yoshida, T., Nishi, I., Fujimori, A., Kotani, Y., Ono, K., Nakashima, Y., Yamaichi, S., Sasagawa, T., Nakajima, M., Kihou, K., Tomioka, Y., Lee, C. H., Iyo, A., Eisaki, H., Ito, T., Uchida, S., and Arita, R.

Subjects
Condensed Matter - Superconductivity
Abstract

In order to examine to what extent the rigid-band-like electron doping scenario is applicable to the transition metal-substituted Fe-based superconductors, we have performed angle-resolved photoemission spectroscopy studies of Ba(Fe$_{1-x}$Ni$_{x}$)$_2$As$_2$ (Ni-122) and Ba(Fe$_{1-x}$Cu$_{x}$)$_2$As$_2$ (Cu-122), and compared the results with Ba(Fe$_{1-x}$Co$_x$)$_2$As$_2$ (Co-122). We find that Ni 3$\it{d}$-derived features are formed below the Fe 3$\it{d}$ band and that Cu 3$\it{d}$-derived ones further below it. The electron and hole Fermi surface (FS) volumes are found to increase and decrease with substitution, respectively, qualitatively consistent with the rigid-band model. However, the total extra electron number estimated from the FS volumes (the total electron FS volume minus the total hole FS volume) is found to decrease in going from Co-, Ni-, to Cu-122 for a fixed nominal extra electron number, that is, the number of electrons that participate in the formation of FS decreases with increasing impurity potential. We find that the N$\acute{\rm{e}}$el temperature $T_{\rm{N}}$ and the critical temperature $T_{\it{c}}$ maximum are determined by the FS volumes rather than the nominal extra electron concentration nor the substituted atom concentration., Comment: Total: 9 pages, 10 figures

Published
2012
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12. Angle-resolved photoemission spectroscopy study of PrFeAsO_{0.7}: Dependence of the electronic structure on the pnictogen height

Author

Nishi, I., Ishikado, M., Ideta, S., Malaeb, W., Yoshida, T., Fujimori, A., Kotani, Y., Kubota, M., Ono, K., Yi, M., Lu, D. H., Moore, R., Shen, Z. -X., Iyo, A., Kihou, K., Kito, H., Eisaki, H., Shamoto, S., and Arita, R.

Subjects
Condensed Matter - Superconductivity
Abstract

We have performed an angle-resolved photoemission spectroscopy (ARPES) study of the iron-based superconductor PrFeAsO_{0.7} and examined the Fermi surfaces and band dispersions near the Fermi level. Heavily hole-doped electronic states have been observed due to the polar nature of the cleaved surfaces. Nevertheless, we have found that the ARPES spectra basically agree with band dispersions calculated in the local density approximation (LDA) if the bandwidth is reduced by a factor of ~2.5 and then the chemical potential is lowered by ~70 meV. Comparison with previous ARPES results on LaFePO reveals that the energy positions of the d_{3z^2-r^2}- and d_{yz,zx}-derived bands are considerably different between the two materials, which we attribute to the different pnictogen height as predicted by the LDA calculation.

Published
2011
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13. Multimodal analysis of Zr substitution effects on magnetic and crystallographic properties in (Sm1−Zr )(Fe0.8Co0.2)12 compounds with ThMn12 structure

Author

Kobayashi, S., primary, Ogawa, D., additional, Xu, X.D., additional, Takahashi, Y.K., additional, Martin-Cid, A., additional, Ishigami, K., additional, Kotani, Y., additional, Suzuki, M., additional, Yoshioka, T., additional, Tsuchiura, H., additional, Sepehri-Amin, H., additional, Ohkubo, T., additional, Hono, K., additional, Hirosawa, S., additional, and Nakamura, T., additional

Published
2023
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15. Growth parameters in children with achondroplasia: A 7-year, prospective, multinational, observational study.

Author

Savarirayan, R, Irving, M, Harmatz, P, Delgado, B, Wilcox, WR, Philips, J, Owen, N, Bacino, CA, Tofts, L, Charrow, J, Polgreen, LE, Hoover-Fong, J, Arundel, P, Ginebreda, I, Saal, HM, Basel, D, Font, RU, Ozono, K, Bober, MB, Cormier-Daire, V, Le Quan Sang, K-H, Baujat, G, Alanay, Y, Rutsch, F, Hoernschemeyer, D, Mohnike, K, Mochizuki, H, Tajima, A, Kotani, Y, Weaver, DD, White, KK, Army, C, Larrimore, K, Gregg, K, Jeha, G, Milligan, C, Fisheleva, E, Huntsman-Labed, A, Day, J, Savarirayan, R, Irving, M, Harmatz, P, Delgado, B, Wilcox, WR, Philips, J, Owen, N, Bacino, CA, Tofts, L, Charrow, J, Polgreen, LE, Hoover-Fong, J, Arundel, P, Ginebreda, I, Saal, HM, Basel, D, Font, RU, Ozono, K, Bober, MB, Cormier-Daire, V, Le Quan Sang, K-H, Baujat, G, Alanay, Y, Rutsch, F, Hoernschemeyer, D, Mohnike, K, Mochizuki, H, Tajima, A, Kotani, Y, Weaver, DD, White, KK, Army, C, Larrimore, K, Gregg, K, Jeha, G, Milligan, C, Fisheleva, E, Huntsman-Labed, A, and Day, J

Abstract

PURPOSE: This study was undertaken to collect baseline growth parameters in children with achondroplasia who might enroll in interventional trials of vosoritide, and to establish a historical control. METHODS: In this prospective, observational study, participants (≤17 years) underwent a detailed medical history and physical examination and were followed every 3 months until they finished participating in the study by enrolling in an interventional trial or withdrawing. RESULTS: A total of 363 children were enrolled (28 centers, 8 countries). Mean (SD) follow up was 20.4 (15.0) months. In participants <1 year, mean annualized growth velocity (AGV) was 11.6 cm/year for girls and 14.6 cm/year for boys. By age 1 year, mean AGV decreased to 7.4 cm/year in girls and 7.1 cm/year in boys. By age 10 years, mean AGV decreased to 3.6 cm/year for both sexes. Mean height z-score in participants <1 year was -2.5 for girls and -3.2 for boys and decreased up to the age 5 years (-5.3 for girls; -4.6 for boys). Girls and boys had a disproportionate upper-to-lower body segment ratio. Mean ratio was highest in participants aged <1 year (2.9 for girls; 2.8 for boys) and decreased gradually to approximately 2 in both sexes from 4 years of age onward. CONCLUSION: This study represents one of the largest datasets of prospectively collected medical and longitudinal growth data in children with achondroplasia. It serves as a robust historical control to measure therapeutic interventions against and to further delineate the natural history of this condition.

Published
2022

21. High-field soft-x-ray dichroism of a hard ferrimagnet with easy-plane anisotropy

Author

Yamamoto, S., Gorbunov, D., Diaz-Ortega, I. F., Miyata, A., Kihara, T., Kotani, Y., Nakamura, T., Mushnikov, N. V., Andreev, A. V., Nojiri, H., and Wosnitza, J.

Abstract

We performed soft x-ray spectroscopic studies of the ferrimagnet TbFe5Al7 with strong easy-plane anisotropy in pulsed magnetic fields up to 29 T along with bulk magnetization and magnetostriction measurements. We observed pronounced amplitude changes of x-ray magnetic circular dichroism and x-ray absorption spectra at the field-induced magnetic transition. This microscopically evidences the simultaneous rotation of the Tb 4 f and Fe 3d magnetic moments from a collinear ferrimagnetic order along the [100] axis to a state with the moments close to [010], the other easy-axis direction of the tetragonal lattice in magnetic fields applied along the [100] axis. We determined the magnetic-anisotropy constant of TbFe5Al7 by simulating the high-field macro- and microscopic magnetization process using a two-sublattice model.

Published
2021

23. Element-specific field-induced spin reorientation and tetracritical point in MnCr2S4

Author

Yamamoto, S., Suwa, H., Kihara, T., Nomura, T., Kotani, Y., Nakamura, T., Scurschii, I., Zherlitsyn, S., Prodan, L., Tsurkan, V., Nojiri, H., Loidl, A., and Wosnitza, J.

Abstract

The ferrimagnetic spinel MnCr2S4 shows a variety of magnetic-field-induced phase transitions owing to bond frustration and strong spin-lattice coupling. However, the site-resolved magnetic properties at the respective field-induced phases in high magnetic fields remain elusive. Our soft x-ray magnetic circular dichroism studies up to 40 T directly evidence element-selective magnetic-moment reorientations in the field-induced phases. The complex magnetic structures are further supported by entropy changes extracted from magnetocaloric-effect measurements. Moreover, thermodynamic experiments reveal an unusual tetracritical point in the H-T phase diagram of MnCr2S4 due to strong spin-lattice coupling.

Published
2021

24. Response to correspondence on 'Reproducibility of CRISPR-Cas9 methods for generation of conditional mouse alleles: a multi-center evaluation'.

Author

Gurumurthy, CB, O'Brien, AR, Quadros, RM, Adams, J, Alcaide, P, Ayabe, S, Ballard, J, Batra, SK, Beauchamp, M-C, Becker, KA, Bernas, G, Brough, D, Carrillo-Salinas, F, Chan, W, Chen, H, Dawson, R, DeMambro, V, D'Hont, J, Dibb, K, Eudy, JD, Gan, L, Gao, J, Gonzales, A, Guntur, A, Guo, H, Harms, DW, Harrington, A, Hentges, KE, Humphreys, N, Imai, S, Ishii, H, Iwama, M, Jonasch, E, Karolak, M, Keavney, B, Khin, N-C, Konno, M, Kotani, Y, Kunihiro, Y, Lakshmanan, I, Larochelle, C, Lawrence, CB, Li, L, Lindner, V, Liu, X-D, Lopez-Castejon, G, Loudon, A, Lowe, J, Jerome-Majeweska, L, Matsusaka, T, Miura, H, Miyasaka, Y, Morpurgo, B, Motyl, K, Nabeshima, Y-I, Nakade, K, Nakashiba, T, Nakashima, K, Obata, Y, Ogiwara, S, Ouellet, M, Oxburgh, L, Piltz, S, Pinz, I, Ponnusamy, MP, Ray, D, Redder, RJ, Rosen, CJ, Ross, N, Ruhe, MT, Ryzhova, L, Salvador, AM, Alam, SS, Sedlacek, R, Sharma, K, Smith, C, Staes, K, Starrs, L, Sugiyama, F, Takahashi, S, Tanaka, T, Trafford, A, Uno, Y, Vanhoutte, L, Vanrockeghem, F, Willis, BJ, Wright, CS, Yamauchi, Y, Yi, X, Yoshimi, K, Zhang, X, Zhang, Y, Ohtsuka, M, Das, S, Garry, DJ, Hochepied, T, Thomas, P, Parker-Thornburg, J, Adamson, AD, Yoshiki, A, Schmouth, J-F, Golovko, A, Thompson, WR, Lloyd, KCK, Wood, JA, Cowan, M, Mashimo, T, Mizuno, S, Zhu, H, Kasparek, P, Liaw, L, Miano, JM, Burgio, G, Gurumurthy, CB, O'Brien, AR, Quadros, RM, Adams, J, Alcaide, P, Ayabe, S, Ballard, J, Batra, SK, Beauchamp, M-C, Becker, KA, Bernas, G, Brough, D, Carrillo-Salinas, F, Chan, W, Chen, H, Dawson, R, DeMambro, V, D'Hont, J, Dibb, K, Eudy, JD, Gan, L, Gao, J, Gonzales, A, Guntur, A, Guo, H, Harms, DW, Harrington, A, Hentges, KE, Humphreys, N, Imai, S, Ishii, H, Iwama, M, Jonasch, E, Karolak, M, Keavney, B, Khin, N-C, Konno, M, Kotani, Y, Kunihiro, Y, Lakshmanan, I, Larochelle, C, Lawrence, CB, Li, L, Lindner, V, Liu, X-D, Lopez-Castejon, G, Loudon, A, Lowe, J, Jerome-Majeweska, L, Matsusaka, T, Miura, H, Miyasaka, Y, Morpurgo, B, Motyl, K, Nabeshima, Y-I, Nakade, K, Nakashiba, T, Nakashima, K, Obata, Y, Ogiwara, S, Ouellet, M, Oxburgh, L, Piltz, S, Pinz, I, Ponnusamy, MP, Ray, D, Redder, RJ, Rosen, CJ, Ross, N, Ruhe, MT, Ryzhova, L, Salvador, AM, Alam, SS, Sedlacek, R, Sharma, K, Smith, C, Staes, K, Starrs, L, Sugiyama, F, Takahashi, S, Tanaka, T, Trafford, A, Uno, Y, Vanhoutte, L, Vanrockeghem, F, Willis, BJ, Wright, CS, Yamauchi, Y, Yi, X, Yoshimi, K, Zhang, X, Zhang, Y, Ohtsuka, M, Das, S, Garry, DJ, Hochepied, T, Thomas, P, Parker-Thornburg, J, Adamson, AD, Yoshiki, A, Schmouth, J-F, Golovko, A, Thompson, WR, Lloyd, KCK, Wood, JA, Cowan, M, Mashimo, T, Mizuno, S, Zhu, H, Kasparek, P, Liaw, L, Miano, JM, and Burgio, G

Published
2021

25. Bulk and element specific magnetism of the medium and high entropy Cantor-Wu alloys

Author

Billington, David P, James, Alyn D N, Harris-Lee, Eddie I, Lagos, Daniel A, O'Neill, Daniel, Tsuda, N., Toyoki, K., Kotani, Y., Nakamura, T., Bei, Hongbin, Mu, Sai, Samolyuk, German, Stocks, GM, Duffy, Jonathan, Taylor, Jonathan, Giblin, Sean, and Dugdale, Stephen B

Abstract

Magnetic Compton scattering, x-ray magnetic circular dichroism spectroscopy and bulk magnetometry measurements are performed on a set of medium (NiFeCo and NiFeCoCr) and high (NiFeCoCrPd and NiFeCoCrMn) entropy Cantor-Wu alloys. The bulk spin momentum densities determined by magnetic Compton scattering are remarkably isotropic, and this is a consequence of the smearing of the electronic structure by disorder scattering of the electron quasiparticles. Nonzero x-ray magnetic circular dichroism signals are observed for every element in every alloy indicating differences in the populations of the majority and minority spin states implying finite magnetic moments. When Cr is included in the solid solution, the Cr spin moment is unambiguously antiparallel to the total magnetic moment, while a vanishingly small magnetic moment is observed for Mn, despite calculations indicating a large moment. Some significant discrepancies are observed between the experimental bulk and surface magnetic moments. Despite the lack of quantitative agreement, the element specific surface magnetic moments seem to be qualitatively reasonable.

Published
2020

27. Element- and orbital-selective magnetic coherent rotation at the first-order phase transition of a hard uniaxial ferrimagnet

Author

Yamamoto, S., Gorbunov, D., Akai, H., Yasumura, H., Kotani, Y., Nakamura, T., Kato, T., Mushnikov, N. V., Andreev, A. V., Nojiri, H., and Wosnitza, J.

Subjects
Condensed Matter::Materials Science, Condensed Matter::Strongly Correlated Electrons
Abstract

3d-4 f intermetalic compounds with heavy rare-earth elements show first-order phase transitions in high magnetic fields due to the competition between the exchange interaction and the magnetocrystalline anisotropy. However, the microscopic picture of the field-induced noncollinear magnetic structures remains elusive. Here we report the direct experimental observation of the coherent stepwise rotation of the 3d and 4 f magnetic moments of the uniaxial hard ferrimagnet TmFe5Al7 by using soft x-ray magnetic circular dichroism in pulsed magnetic fields up to 25 T. The element- and shell-selective moments show a transition from the collinear ferrimagnet toward the forced ferromagnetic state via a canted phase, which is explained by a two-sublattice model.

Published
2020

28. Element- and orbital-selective magnetic coherent rotation at the first-order phase transition of a hard uniaxial ferrimagnet

Author

(0000-0001-5819-2867) Yamamoto, S., Gorbunov, D., Akai, H., Yasumura, H., Kotani, Y., Nakamura, T., Kato, T., Mushnikov, N. V., Andreev, A. V., Nojiri, H., Wosnitza, J., (0000-0001-5819-2867) Yamamoto, S., Gorbunov, D., Akai, H., Yasumura, H., Kotani, Y., Nakamura, T., Kato, T., Mushnikov, N. V., Andreev, A. V., Nojiri, H., and Wosnitza, J.

Abstract

3d-4 f intermetalic compounds with heavy rare-earth elements show first-order phase transitions in high magnetic fields due to the competition between the exchange interaction and the magnetocrystalline anisotropy. However, the microscopic picture of the field-induced noncollinear magnetic structures remains elusive. Here we report the direct experimental observation of the coherent stepwise rotation of the 3d and 4 f magnetic moments of the uniaxial hard ferrimagnet TmFe5Al7 by using soft x-ray magnetic circular dichroism in pulsed magnetic fields up to 25 T. The element- and shell-selective moments show a transition from the collinear ferrimagnet toward the forced ferromagnetic state via a canted phase, which is explained by a two-sublattice model.

Published
2020

30. Bulk and element-specific magnetism of medium-entropy and high-entropy Cantor-Wu alloys

Author

Billington, D., primary, James, A. D. N., additional, Harris-Lee, E. I., additional, Lagos, D. A., additional, O'Neill, D., additional, Tsuda, N., additional, Toyoki, K., additional, Kotani, Y., additional, Nakamura, T., additional, Bei, H., additional, Mu, S., additional, Samolyuk, G. D., additional, Stocks, G. M., additional, Duffy, J. A., additional, Taylor, J. W., additional, Giblin, S. R., additional, and Dugdale, S. B., additional

Published
2020
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38. Magnetic Microscopy Using a Circularly Polarized Hard-X-ray Nanoprobe at SPring-8

Author

Suzuki, M., primary, Yumoto, H., additional, Koyama, T., additional, Yamazaki, H., additional, Takeuchi, T., additional, Kawamura, N., additional, Mizumaki, M., additional, Osawa, H., additional, Kondo, Y., additional, Ariake, J., additional, Yasui, A., additional, Kotani, Y., additional, Tsuji, N., additional, Nakamura, T., additional, Hirosawa, S., additional, Yamada, K. T., additional, Kim, S., additional, Kim, K.-J., additional, Ishibashi, M., additional, Ono, T., additional, and Ohashi, H., additional

Published
2020
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48. Reproducibility of CRISPR-Cas9 methods for generation of conditional mouse alleles: a multi-center evaluation.

Author

Gurumurthy, CB, O'Brien, AR, Quadros, RM, Adams, J, Alcaide, P, Ayabe, S, Ballard, J, Batra, SK, Beauchamp, M-C, Becker, KA, Bernas, G, Brough, D, Carrillo-Salinas, F, Chan, W, Chen, H, Dawson, R, DeMambro, V, D'Hont, J, Dibb, KM, Eudy, JD, Gan, L, Gao, J, Gonzales, A, Guntur, AR, Guo, H, Harms, DW, Harrington, A, Hentges, KE, Humphreys, N, Imai, S, Ishii, H, Iwama, M, Jonasch, E, Karolak, M, Keavney, B, Khin, N-C, Konno, M, Kotani, Y, Kunihiro, Y, Lakshmanan, I, Larochelle, C, Lawrence, CB, Li, L, Lindner, V, Liu, X-D, Lopez-Castejon, G, Loudon, A, Lowe, J, Jerome-Majewska, LA, Matsusaka, T, Miura, H, Miyasaka, Y, Morpurgo, B, Motyl, K, Nabeshima, Y-I, Nakade, K, Nakashiba, T, Nakashima, K, Obata, Y, Ogiwara, S, Ouellet, M, Oxburgh, L, Piltz, S, Pinz, I, Ponnusamy, MP, Ray, D, Redder, RJ, Rosen, CJ, Ross, N, Ruhe, MT, Ryzhova, L, Salvador, AM, Alam, SS, Sedlacek, R, Sharma, K, Smith, C, Staes, K, Starrs, L, Sugiyama, F, Takahashi, S, Tanaka, T, Trafford, AW, Uno, Y, Vanhoutte, L, Vanrockeghem, F, Willis, BJ, Wright, CS, Yamauchi, Y, Yi, X, Yoshimi, K, Zhang, X, Zhang, Y, Ohtsuka, M, Das, S, Garry, DJ, Hochepied, T, Thomas, P, Parker-Thornburg, J, Adamson, AD, Yoshiki, A, Schmouth, J-F, Golovko, A, Thompson, WR, Lloyd, KCK, Wood, JA, Cowan, M, Mashimo, T, Mizuno, S, Zhu, H, Kasparek, P, Liaw, L, Miano, JM, Burgio, G, Gurumurthy, CB, O'Brien, AR, Quadros, RM, Adams, J, Alcaide, P, Ayabe, S, Ballard, J, Batra, SK, Beauchamp, M-C, Becker, KA, Bernas, G, Brough, D, Carrillo-Salinas, F, Chan, W, Chen, H, Dawson, R, DeMambro, V, D'Hont, J, Dibb, KM, Eudy, JD, Gan, L, Gao, J, Gonzales, A, Guntur, AR, Guo, H, Harms, DW, Harrington, A, Hentges, KE, Humphreys, N, Imai, S, Ishii, H, Iwama, M, Jonasch, E, Karolak, M, Keavney, B, Khin, N-C, Konno, M, Kotani, Y, Kunihiro, Y, Lakshmanan, I, Larochelle, C, Lawrence, CB, Li, L, Lindner, V, Liu, X-D, Lopez-Castejon, G, Loudon, A, Lowe, J, Jerome-Majewska, LA, Matsusaka, T, Miura, H, Miyasaka, Y, Morpurgo, B, Motyl, K, Nabeshima, Y-I, Nakade, K, Nakashiba, T, Nakashima, K, Obata, Y, Ogiwara, S, Ouellet, M, Oxburgh, L, Piltz, S, Pinz, I, Ponnusamy, MP, Ray, D, Redder, RJ, Rosen, CJ, Ross, N, Ruhe, MT, Ryzhova, L, Salvador, AM, Alam, SS, Sedlacek, R, Sharma, K, Smith, C, Staes, K, Starrs, L, Sugiyama, F, Takahashi, S, Tanaka, T, Trafford, AW, Uno, Y, Vanhoutte, L, Vanrockeghem, F, Willis, BJ, Wright, CS, Yamauchi, Y, Yi, X, Yoshimi, K, Zhang, X, Zhang, Y, Ohtsuka, M, Das, S, Garry, DJ, Hochepied, T, Thomas, P, Parker-Thornburg, J, Adamson, AD, Yoshiki, A, Schmouth, J-F, Golovko, A, Thompson, WR, Lloyd, KCK, Wood, JA, Cowan, M, Mashimo, T, Mizuno, S, Zhu, H, Kasparek, P, Liaw, L, Miano, JM, and Burgio, G

Abstract

BACKGROUND: CRISPR-Cas9 gene-editing technology has facilitated the generation of knockout mice, providing an alternative to cumbersome and time-consuming traditional embryonic stem cell-based methods. An earlier study reported up to 16% efficiency in generating conditional knockout (cKO or floxed) alleles by microinjection of 2 single guide RNAs (sgRNA) and 2 single-stranded oligonucleotides as donors (referred herein as "two-donor floxing" method). RESULTS: We re-evaluate the two-donor method from a consortium of 20 laboratories across the world. The dataset constitutes 56 genetic loci, 17,887 zygotes, and 1718 live-born mice, of which only 15 (0.87%) mice contain cKO alleles. We subject the dataset to statistical analyses and a machine learning algorithm, which reveals that none of the factors analyzed was predictive for the success of this method. We test some of the newer methods that use one-donor DNA on 18 loci for which the two-donor approach failed to produce cKO alleles. We find that the one-donor methods are 10- to 20-fold more efficient than the two-donor approach. CONCLUSION: We propose that the two-donor method lacks efficiency because it relies on two simultaneous recombination events in cis, an outcome that is dwarfed by pervasive accompanying undesired editing events. The methods that use one-donor DNA are fairly efficient as they rely on only one recombination event, and the probability of correct insertion of the donor cassette without unanticipated mutational events is much higher. Therefore, one-donor methods offer higher efficiencies for the routine generation of cKO animal models.

Published
2019

49. Observation of orbital angular momentum in the chiral magnet CrNb3S6 by soft x-ray magnetic circular dichroism

Author

Mito, M., Ohsumi, H., Shishidou, T., Kuroda, F., Weinert, M., Tsuruta, K., Kotani, Y., Nakamura, T., Togawa, Y., Kishine, J., Kousaka, Y., Akimitsu, J., Inoue, K., Mito, M., Ohsumi, H., Shishidou, T., Kuroda, F., Weinert, M., Tsuruta, K., Kotani, Y., Nakamura, T., Togawa, Y., Kishine, J., Kousaka, Y., Akimitsu, J., and Inoue, K.

Abstract

The chiral magnet CrNb3S6 with its solitonic objects has novel magnetic and transport properties, in which the spin-orbit coupling (SOC) plays a central role. Aiming to address the possible existence of orbital moments driven by SOC, we perform soft x-ray magnetic circular dichroism spectroscopy at the Cr L2,3 edges with in-plane magnetization. The dichroic signals provide direct experimental evidence that the Cr orbital magnetic moment is not quenched and is coupled antiparallel to the spin counterpart. Application of the orbital sum rule reveals that the magnitude of the Cr orbital moment is about 1% of the total magnetization. These findings are consistent with the first-principles electronic structure calculations that utilize the Cr 2p core radial function to define the Cr local 3d quantities. The distinct roles of the atomic SOC among the Cr 3d and Nb 4d states are discussed.

Published
2019

50. Diffuse interface model to simulate the rise of a fluid droplet across a cloud of particles

Author

Lecrivain, G., Kotani, Y., Yamamoto, R., Hampel, U., and Taniguchi, T.

Subjects
Physics::Fluid Dynamics, three phase flows, particles at fluidic interface, rising droplet, direct numerical simulation, Diffuse interface model
Abstract

A large variety of industrial and natural systems involve the adsorption of solid particles to the fluidic interface of droplets in motion. A diffuse interface model is here suggested to directly simulate the three-dimensional dynamics of a fluid droplet rising across a cloud of large particles. In this three-phase model the two solid-fluid boundaries and the fluidic boundary are replaced with smoothly spreading interfaces. A significant advantage of the method lies in the fact that the capillary effects, the three-phase flow hydrodynamics, and the inter-particle collisions are all resolved. We first report important numerical limitations associated with the inter-particle collisions in diffuse interface models. In a second stage the effect of the particle concentration on the terminal velocity of a rising fluid droplet is investigated. It is found that, in a quiescent environment, the terminal velocity of the rising the fluid droplet decreases exponentially with the particle concentration. This exponential decay is also confirmed by a simple rheological model.

Published
2018

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