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2,454 results on '"Sugawara, T."'

8. Observation of Fermi-surface-dependent nodeless superconducting gaps in Ba0.6K0.4Fe2As2

Author

Ding, H., Richard, P., Nakayama, K., Sugawara, T., Arakane, T., Sekiba, Y., Takayama, A., Souma, S., Sato, T., Takahashi, T., Wang, Z., Dai, X., Fang, Z., Chen, G. F., Luo, J. L., and Wang, N. L.

Subjects
Condensed Matter - Superconductivity
Abstract

The recent discovery of superconductivity in iron-arsenic compounds below a transition temperature (Tc) as high as 55K ended the monopoly of copper oxides (cuprates) in the family of high-Tc superconductors. A critical issue in understanding this new superconductor, as in the case of cuprates, is the nature, in particular the symmetry and orbital dependence, of the superconducting gap. There are conflicting experimental results, mostly from indirect measurements of the low energy excitation gap, ranging from one gap to two gaps, from line nodes to nodeless gap function in momentum space. Here we report a direct observation of the superconducting gap, including its momentum, temperature, and Fermi surface (FS) dependence in Ba0.6K0.4Fe2As2 (Tc = 37 K) using angle-resolved photoelectron spectroscopy. We find two superconducting gaps with different values: a large gap (~ 12 meV) on the two small hole-like and electron-like FS sheets, and a small gap (~ 6 meV) on the large hole-like FS. Both gaps, closing simultaneously at the bulk Tc, are nodeless and nearly isotropic around their respective FS sheets. The isotropic pairing interactions are strongly orbital dependent, as the ratio 2Delta/kBTc switches from weak to strong coupling on different bands. The same and surprisingly large superconducting gap due to strong pairing on the two small FS, which are connected by the (pi, 0) spin-density-wave vector in the parent compound, strongly suggests that the pairing mechanism originates from the inter-band interactions between these two nested FS sheets., Comment: 4 figures

Published
2008
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23. Evaluation of contrast visual acuity in patients with retinitis pigmentosa

Author

Oomachi K, Ogata K, Sugawara T, Hagiwara A, Hata A, and Yamamoto S.

Subjects
Ophthalmology, RE1-994
Abstract

Kazumi Oomachi1, Kazuha Ogata2, Takeshi Sugawara2, Akira Hagiwara2, Akira Hata1, Shuichi Yamamoto21Department of Public Health; 2Department of Ophthalmology, Chiba University Graduate School of Medicine, Chiba, JapanBackground: The purpose of this study was to determine visual acuity at different contrast levels under photopic and mesopic conditions in patients with retinitis pigmentosa.Methods: Sixty eyes of 31 normal controls, 92 eyes of 52 patients with retinitis pigmentosa without other ocular disorders (RP-1 group), and 20 eyes of 14 patients with retinitis pigmentosa with cataracts and without other ocular disorders (RP-2 group) were studied. Conventional visual acuity was measured using a conventional Landolt ring chart with 100% contrast and luminance of 150 cd/m2. All of the patients with retinitis pigmentosa had a decimal visual acuity better than 1.0. Contrast visual acuity was measured with the same Landolt ring chart with contrasts of 100% and 10% and under photopic (200 cd/m2) and mesopic (10 cd/m2) conditions. Decimal visual acuities were converted to logMAR units for the analyses.Results: The 100% contrast visual acuity and the 10% contrast visual acuity determined under both photopic and mesopic conditions were significantly poorer in both the RP-1 and RP-2 groups than in the controls. The differences between the conventional visual acuity and the 100% contrast visual acuity were significantly greater in the RP-1 and RP-2 groups than in the controls under both photopic and mesopic conditions. The differences between the 100% contrast visual acuity and the 10% contrast visual acuity were not significant among the three groups under photopic and mesopic conditions.Conclusion: Contrast visual acuities were greatly reduced in patients with retinitis pigmentosa with relatively well preserved conventional visual acuity, and the contrast visual acuity was largely influenced by ambient light levels in patients with retinitis pigmentosa. Although a longitudinal study for confirmation has to be performed, our findings indicate that contrast visual acuity is a better test to follow changes in visual function in patients with retinitis pigmentosa.Keywords: retinitis pigmentosa, contrast visual acuity, photopic vision, mesopic vision

Published
2011

30. Ophthalmoplegia associated with transorbital penetrating brainstem injury by broken fishing pole

Author

Kaneko-Ohtaki A, Machida S, Sugawara T, and Kurosaka D

Subjects
Ophthalmology, RE1-994
Abstract

Aki Kaneko-Ohtaki, Shigeki Machida, Takeshi Sugawara, Daijiro KurosakaDepartment of Ophthalmology, Iwate Medical University School of Medicine, Iwate, JapanAbstract: We report our findings in a case of ophthalmoplegia caused by a transorbital penetrating brainstem injury. An 8-year-old boy was accidentally injured by a broken fishing fiberglass pole which penetrated through the right orbit and entered the brainstem. Magnetic resonance imaging showed a linear wound that entered and passed through the pons obliquely and reached the fourth cerebral ventricle and cerebellar vermis. He had a left-sided hemiplegia and left facial nerve palsy and was diagnosed with “one-and-a-half syndrome”. His hemiplegia and left facial nerve palsy resolved in 2 weeks leaving only a left abducens nerve palsy. The eye position and eye movements fully recovered within 3 months. These findings suggest a good prognosis for this type of trauma unless life-threatening changes develop.Keywords: penetrating orbitocranial trauma, trauma, penetrating orbitocranial injury

Published
2011

33. High-performance hardware architectures for galois counter mode

Author

Satoh, A., Sugawara, T., and Aoki, T.

Subjects
Performance analysis/diagnostic software, Computers -- Design and construction, Computers -- Evaluation, Performance analysis software -- Usage, Very-large-scale integration -- Usage
Published
2009

34. Exploratory aspirin resistance trial in healthy Japanese volunteers (J-ART) using platelet aggregation as a measure of thrombogenicity

Author

Fujiwara, T, Ikeda, M, Esumi, K, Fujita, T D, Kono, M, Tokushige, H, Hatoyama, T, Maeda, T, Asai, T, Ogawa, T, Katsumata, T, Sasaki, S, Suzuki, E, Suzuki, M, Hino, F, Fujita, T K, Zaima, H, Shimada, M, Sugawara, T, Tsuzuki, Y, Hashimoto, Y, Hishigaki, H, Horimoto, S, Miyajima, N, Yamamoto, T, Imagawa, K, Sesoko, S, and Fujisawa, Y

Published
2007
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