89 results on '"Yuasa, T"'
Search Results
2. Effect of chemical oxide layers on platinum-enhanced oxidation of silicon.
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Namba, K., Yuasa, T., Nakato, Y., Yoneda, K., Kato, H., and Kobayashi, H.
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SILICON , *PHOTOELECTRON spectroscopy , *SYNCHROTRON radiation - Abstract
Si oxidation promoted by a platinum (Pt) overlayer has been investigated using x-ray photoelectron spectroscopy and synchrotron radiation ultraviolet photoelectron spectroscopy. Heat treatments of the specimens with <∼5-nm-Pt/0.5−1-nm-chemical oxide/Si(100)> structure at 300-400 °C increase the oxide thickness to 4-5 nm. The amounts of the suboxide species, a(Si[sup +]), a(Si[sup 2+]), and a(Si[sup 3+]), in the chemical oxide layers formed in hydrochloric acid (HCl) plus hydrogen peroxide (H[sub 2]O[sub 2]) are in the order of a(Si[sup +])>a(Si[sup 2+])>a(Si[sup 3+]), while those for the oxide layers formed in nitric acid (HNO[sub 3]) have an order of a(Si[sup 3+])>a(Si[sup 2+])≈a(Si[sup +]). The amounts of the suboxide species in the former oxide layers are much higher than those in the latter oxide layers. These results indicate that the HNO[sub 3] oxide layers are more highly oxidized, probably resulting in a higher atomic density and a lower defect density. Although the initial chemical oxide layers formed in HCl+H[sub 2]O[sub 2] are thinner than those grown in HNO[sub 3] the former oxide layers become thicker than the latter after the Pt deposition and the heat treatments below 200 °C. This result is attributed to the lower atomic density and the higher defect density of the chemical oxide layers produced in HCl+H[sub 2]O[sub 2], which enhance the diffusion of oxidizing species. It is suggested that the variation in the atomic density of the chemical oxide layers cause the different energy distribution of interface states in the Si band gap. © 1997 American Institute of Physics. [ABSTRACT FROM AUTHOR]
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- 1997
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3. Comparison of medically versus surgically treated acute type a aortic dissection in patients <80 years old versus patients ≥80 years old.
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Yanagisawa S, Yuasa T, Suzuki N, Hirai T, Yasuda N, Miki K, Yasuura K, Horiuchi K, Tanaka T, Yanagisawa, Satoshi, Yuasa, Takeshi, Suzuki, Noriyuki, Hirai, Toshihisa, Yasuda, Nobuyuki, Miki, Ken, Yasuura, Kenzo, Horiuchi, Kazutaka, and Tanaka, Toshikazu
- Abstract
Although recent progress in emergency surgery has resulted in an increase in the indication for older patients with acute type A aortic dissection (AAD), some patients remain who cannot undergo surgical treatment and little is known about the prognosis of patients with AAD who receive medical treatment, especially in elderly patients. Of the 82 patients with AAD who were admitted to our institution, 48 received medical therapy only. We retrospectively reviewed their clinical data and analyzed the prognostic value of the clinical characteristics in both younger and older patients. The in-hospital and 1-year mortality were significantly lower in the patients who underwent surgical treatment than in those who received medical treatment (6% vs 65%, p <0.001; 8% vs 73%, p <0.001, respectively). Of the patients with medical treatment, the in-hospital and 1-year mortality rate in the younger (<80 years old, n = 27) and older (≥80 years old, n = 21) groups was 70% and 80% and 57% and 65%, respectively. For the younger group, the presence of an open false lumen was significantly associated with in-hospital mortality (89% vs 50%, p = 0.044). In contrast, in the older group, a lower serum albumin level (3.4 ± 0.3 vs 4.0 ± 0.5 g/dl, p = 0.010) and the incidence of an open false lumen (83% vs 33%, p = 0.032) were significantly associated with in-hospital mortality. In conclusion, in addition to an open false lumen as a risk factor, a lower serum albumin level is an important prognostic factor in older patients with AAD. [ABSTRACT FROM AUTHOR]
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- 2011
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4. Whole-atom Compton scattering cross-sections and individual shell cross-sections for the biological elements in the energy region from 1 to 4keV
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Rao, D.V., Yuasa, T., Akatsuka, T., Tromba, G., Takeda, T., Cesareo, R., Brunetti, A., and Gigante, G.E.
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COMPTON effect , *COMPTON electrons , *ELECTRON beams , *ELECTRON optics - Abstract
Abstract: Whole-atom Compton scattering cross-sections are evaluated for selected biological elements in the energy region from 1 to 4keV and from 5keV to 10MeV, for the other elements. These cross-sections were calculated within the non-relativistic impulse approximation. The Compton profiles utilized here were taken from the tables of Biggs et al. Total cross-section for fixed incident photon energy were obtained by summing the sub-shell contributions. [Copyright &y& Elsevier]
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- 2007
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5. The impact of habitat fragmentation on genetic structure of the Japanese sika deer ( Cervus nippon) in southern Kantoh, revealed by mitochondrial D-loop sequences.
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Yuasa, T., Nagata, J., Hamasaki, S., Tsuruga, H., and Furubayashi, K.
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FRAGMENTED landscapes , *HABITATS , *SIKA deer , *GENETICS , *LANDSCAPE ecology , *POPULATION , *MITOCHONDRIA , *DEER - Abstract
In southern Kantoh, Japanese sika deer ( Cervus nippon) are distributed discontinuously due to large urban areas and developed road networks. To assess the impact of habitat fragmentation on sika deer subpopulations, we examined mitochondrial D-loop sequences from 435 individuals throughout southern Kantoh. About 13 haplotypes were detected, and their distributions revealed spatial genetic structure. Significant genetic differentiation was observed among seven of eight subpopulations. We found no significant correlation between pairwise F ST and geographical distance among subpopulations. Genetic diversity indices suggested that seven of eight subpopulations had probably experienced population bottlenecks in the recent past. Therefore, and in the light of the results of a nested clade analysis of these haplotypes, we conclude that recent fluctuations in population size and the interruption of gene flow due to past and present habitat fragmentation have played major roles influencing the spatial genetic structure of the sika deer population. This is the first evidence of spatial genetic population structure in the highly fragmented sika deer population in Honshu, Japan. [ABSTRACT FROM AUTHOR]
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- 2007
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6. A third-generation bisphosphonate, minodronic acid (YM529), successfully prevented the growth of bladder cancer in vitro and in vivo.
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Sato, K., Yuasa, T., Nogawa, M., Kimura, S., Segawa, H., Yokota, A., and Maekawa, T.
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DIPHOSPHONATES , *BLADDER cancer , *CANCER cell proliferation , *CANCER treatment , *IMMUNOHISTOCHEMISTRY , *CANCER chemotherapy - Abstract
Minodronic acid (YM529) is a third-generation bisphosphonate (BP) that has been shown to directly and indirectly prevent proliferation, induce apoptosis, and inhibit metastasis of various types of cancer cells. In this study, we have investigated the therapeutic efficacy of YM529 against bladder cancer, both in vitro and in vivo. YM529 inhibited geranylgeranylation as well as farnesylation and reduced the growth of all seven bladder cancer cell lines in a dose- and time-dependent manner in vitro. YM529 demonstrated a good synergistic or additive antiproliferative effect when administered in combination with cisplatin or paclitaxel. Immunohistochemical study revealed YM529 inhibited the prenylation of Rap1A in vivo. YM529 administered systemically did not markedly inhibit the growth of visceral metastases but it showed a significant anticancer effect on bone metastases monitored by an in vivo imaging system. Moreover, intravesical YM529 demonstrated significant growth inhibition in a bladder cancer orthotopic model. No adverse effects were associated with the systemic as well as the intravesical treatment regimens. In conclusion, our study suggests that YM529 may be a potent anticancer agent for bladder cancer. The efficacy and safety of this BP as an agent for combination chemotherapies against bladder cancer should be verified by early-phase clinical trials. [ABSTRACT FROM AUTHOR]
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- 2006
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7. Diagnosis of Bone Metastasis in Men with Prostate Cancer by Measurement of Serum ICTP in Combination with Alkali Phosphatase and Prostate-specific Antigen
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Kataoka, A., Yuasa, T., Kageyama, S., Tsuchiya, N., Habuchi, T., Iwaki, H., Narita, M., Okada, Y., and Yoshiki, T.
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METASTASIS , *PROSTATE cancer , *SERUM , *TUMOR markers - Abstract
Abstract: Aims: Carboxy-terminal telopeptide of type I collagen (ICTP) is a parameter of bone absorption, and has recently been introduced to monitor bone metastases. The aim of this retrospective study was to investigate the potential of ICTP as a candidate serum marker of bone metastasis in prostate cancer. Materials and methods: Serum markers in 155 men pathologically diagnosed with prostate cancer were measured. The serum levels of ICTP, prostate-specific antigen (PSA), and alkali phosphatase (ALP) were compared to assess the extent of disease (EOD) scores from bone scans and then analysed statistically. Results: The serum ICTP levels were not well correlated with the EOD scores in the total group of men, men newly diagnosed with prostate cancer, or men previously diagnosed with prostate cancer who were followed up. The sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of ICTP (cut-off value, 5.0ng/ml) of the men newly diagnosed with prostate cancer were 78.6%, 88.0%, 78.6%, and 88.0%, respectively. In these men, the specificity and PPV of ALP (cut-off value, 335IU/l) were 100%, whereas the sensitivity and NPV of PSA (cut-off value, 40ng/ml) were 100% in this study. The serum levels of ICTP in the men with low ALP (<335IU/l) and high PSA (≥40ng/ml) clearly separated the men with or without bone metastasis, as judged by bone scans. Conclusion: We found that the ICTP is not a superior serum marker for bone metastases compared with ALP or PSA. Our study suggests, however, that the ICTP measurement is useful in a certain subset of men with the combination of PSA and ALP in distinguishing men with bone metastasis from those without. [Copyright &y& Elsevier]
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- 2006
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8. Phylogenetic position of the small solitary phaeodarians (Radiolaria) based on 18S rDNA sequences by single cell PCR analysis
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Yuasa, T., Takahashi, O., Dolven, J.K., Mayama, S., Matsuoka, A., Honda, D., and Bjørklund, K.R.
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RADIOLARIA , *PHYLOGENY , *CLADISTIC analysis , *MOLECULAR biology - Abstract
Abstract: Within the holoplanktonic protists group Radiolaria, the Class Phaeodarea is today represented by several hundreds species. The phaeodarian skeletons consist of opaline silica as well as organic matter and are very fragile and vulnerable to dissolution. Their tests are therefore rarely found in the fossil records; this has caused uncertainty with regard to their phylogenetic evolution. In this study, small, solitary phaeodarian species, namely, Protocystis xiphodon (Haeckel), Challengeron diodon Haeckel and Conchellium capsula Borgert were examined using molecular techniques in order to clarify the phylogenetic position of the Phaeodarea. The phylogenetic trees obtained from the neighbor-joining, maximum-parsimony and maximum-likelihood methods of analysis showed that all phaeodarians formed a monophyletic group within the Phylum Cercozoa. This result contradicts Haeckel''s classical taxonomy, wherein the phaeodarians were grouped along with the polycystines, i.e., nassellarians and spumellarians, and the acantharians under the common name “Radiolaria”. Within the cercozoan clade, the Phaeodarea were closely related to the euglyphid and pseudodifflugid testate amoebae and the desmothoracid heliozoans. The tests and skeletons of both the phaeodarians and the euglyphid testate amoebae resemble each other in their chemical composition and construction. The similarities in the morphologic features may suggest that they are sisters as the Phylum Cercozoa in which leading from molecular methods. [Copyright &y& Elsevier]
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- 2006
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9. Images of biological soft tissue using synchrotron X-ray and laser CT systems
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Rao, D.V., Yuasa, T., Akatsuka, T., Tromba, G., Hasan, M.Z., Takeda, T., and Devaraj, B.
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INDUSTRIAL lasers , *SYNCHROTRONS , *MICROMECHANICS , *PARTICLES (Nuclear physics) - Abstract
Abstract: Images of embedded biological soft tissue of snail are obtained using synchrotron X-ray and laser CT systems. The biological soft tissue is embedded in another object and the microstructure is non-uniformly distributed. Under such conditions, the clear identification and occupation of the embedded biological soft tissue is necessary. In order to improve the monochromacy and image quality, the Synchrotron Radiation for Medical Physics facility at Elettra, Trieste, Italy, has been used for the image acquisition. A similar study is performed with a novel trans-illumination laser CT imaging system using optical fiber based on the optical heterodyne detection method for biomedical use. Based on the experimental observations, the proposed system can reconstruct tomographic images of highly scattering objects in the trans-illumination mode, similar to X-ray CT. Finally, images are presented, acquired using the two systems and the importance of these imaging techniques to image the internal structure of the embedded biological soft tissue is discussed. [Copyright &y& Elsevier]
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- 2006
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10. Tomographic images of few soft materials and embedded biological soft tissue using tube source of X-rays at optimum energy
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Rao, D.V., Yuasa, T., Akatsuka, T., Cesareo, R., Gigante, G.E., and Takeda, T.
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X-rays , *TOMOGRAPHY , *MEDICAL radiography , *THREE-dimensional imaging - Abstract
Abstract: Tomographic images are obtained for few soft materials with multi-structure, cylinder with holes of different diameter and biological soft tissue. 2D images are obtained in the transmission mode. 3D images are reconstructed with the use of 2D slices for visualization of the internal structure. We obtained a series of images in the region 24–27keV. 3D visualization of the materials is processed and analyzed the results. The present study is also focused on few geometrical considerations in order to design the collimators in front of the fluorescent source to improve the geometrical efficiency. [Copyright &y& Elsevier]
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- 2006
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11. Tomographic imaging based on scattered radiation from polyethylene using 10, 15, 20, 25 and 30keV synchrotron X-rays with simple approximations
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Rao, D.V., Yuasa, T., Akatsuka, T., Tromba, G., Hasan, M. Zahid, and Takeda, T.
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TOMOGRAPHY , *MEDICAL radiography , *ENGINEERING instruments , *RADIATION - Abstract
Abstract: Tomographic imaging based on scattered radiation from polyethylene (C5H8O2), is evaluated, using 10, 15, 20, 25 and 30keV synchrotron X-rays. The SYRMEP facility at Elettra, Trieste, Italy, has been used to detect the scattered radiation from the sample at an angle of 90° using Si-Pin detector coupled to a multi-channel analyzer. The contribution of transmitted, Compton and fluorescence photons are assessed from a test phantom of small dimensions with simple approximations. The optimum analysis is performed with the use of the dimensions of the sample by detecting the radiation at various energies. [Copyright &y& Elsevier]
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- 2005
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12. Observation of plasmons coupled with optical phonons in n-AlxGa1-xAs by Raman scattering.
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Yuasa, T., Naritsuka, S., Mannoh, M., Shinozaki, K., Yamanaka, K., Nomura, Y., Mihara, M., and Ishii, M.
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PLASMONS (Physics) , *PHONONS , *RAMAN effect - Abstract
Raman scattering from Si-doped n-AlxGa1-xAs (x=0.25) grown by molecular beam epitaxy has been studied at room temperature. In addition to the optical phonon lines, three new Raman lines have been clearly observed in samples with high carrier concentrations (n>=1×1018 cm-3). These lines are identified as the coupled plasmon-longitudinal optical (LO) phonon modes because their frequencies and relative intensities to the LO phonon lines depend on the excitation wavelength. [ABSTRACT FROM AUTHOR]
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- 1985
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13. Suzaku studies of SFXT flare mechanisms.
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Sasano, M., Yuasa, T., Yamada, S., Nakazawa, K., and Makishima, K.
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SOLAR flares , *DATA analysis , *NEUTRON stars , *STELLAR magnetic fields , *ASTROPHYSICS , *DENSITY of stars - Abstract
To understand flare mechanisms of SFXTs, we analyzed Suzaku public data of AXJ161929-4945. The data covered a large flare with a rise time of about 500 sec and a duration of about 3 hours. Over a 1-40 keV band, the spectra were very similar between the flare and quiescence periods. The column density was not different between the two spectra by more than 10%. A narrow Fe-line were very clearly detected in the quiescence, but disappeared in the flare. These results suggest that the flare occurred due to strong magnetic fields of the neutron star. [ABSTRACT FROM AUTHOR]
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- 2012
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14. Photorefractive InGaAs/GaAs multiple quantum wells in the Franz-Keldysh geometry.
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Iwamoto, S., Kageshima, H., Yuasa, T., Nishioka, M., Someya, T., Arakawa, Y., Fukutani, K., Shimura, T., and Kuroda, K.
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QUANTUM wells , *ELECTROOPTICS - Abstract
We fabricate semi-insulating InGaAs/GaAs multiple quantum wells and observe the excitonic enhancement of the photorefractivity in the Franz-Keldysh geometry at wavelengths of 0.92-0.94 μm. A maximum two-wave mixing gain of 138 cm[sup -1] and a maximum diffraction efficiency of 1.5x10[sup -4] are obtained. The saturation intensity and the spatial resolution are also measured by four-wave mixing. The diffraction efficiency is saturated at a high external electric field. The dominant cause of this saturation is the deviation of the excitonic electroabsorption from its quadratic law. © 2001 American Institute of Physics. We fabricate semi-insulating InGaAs/GaAs multiple quantum wells and observe the excitonic enhancement of the photorefractivity in the Franz-Keldysh geometry at wavelengths of 0.92-0.94 μm. A maximum two-wave mixing gain of 138 cm[sup -1] and a maximum diffraction efficiency of 1.5x10[sup -4] are obtained. The saturation intensity and the spatial ! resolution are also measured by four-wave mixing. The diffraction efficiency is saturated at a high external electric field. The dominant cause of this saturation is the deviation of the excitonic electroabsorption from its quadratic law. © 2001 American Institute of Physics. We fabricate semi-insulating InGaAs/GaAs multiple quantum wells and observe the excitonic enhancement of the photorefractivity in the Franz-Keldysh geometry at wavelengths of 0.92-0.94 μm. A maximum two-wave mixing gain of 138 cm[sup -1] and a maximum diffraction efficiency of 1.5x10[sup -4] are obtained. The saturation intensity and the spatial resolution are also measured by four-wave mixing. The diffraction efficiency is saturated at a high external electric field. The dominant cause of this saturation is the deviation of the excitonic electroabsorption from its quadratic law. © 2001 American Institute of Physics. [ABSTRACT FROM AUTHOR]
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- 2001
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15. 22 Second-line combination chemotherapy with cisplatin, gemcitabine and paclitaxel for the treatment of advanced germ cell tumours.
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Tatsuro, T., Yuasa, T., Hagiwara, K., Sano, M., Uehara, S., Ogawa, M., Yamasaki, M., Sakura, M., Masuda, H., Yamamoto, S., and Fukui, I.
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TERATOCARCINOMA , *COMBINATION drug therapy , *CISPLATIN , *HEALTH outcome assessment , *CANCER relapse , *ADVERSE health care events , *THERAPEUTICS - Published
- 2016
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16. 1141 Clinical outcome of the patients with pancreas metastasis from renal cell cancer.
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Yuasa, T., Inoshita, N., Saiura, A., Sukegawa, G., Yamamoto, S., Urakami, S., Masuda, H., Fujii, Y., Fukui, I., Ishikawa, Y., and Yonese, J.
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- 2014
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17. The volume DWI method increases/INS; detectability of small ischemic lesions in patients with transient global amnesia.
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Yuasa, T., Mutsukura, K., Nakao, Y., Ichinose, K., Tomita, I., Satoh, H., Satoh, A., Seto, M., Ochi, M., and Tsujihata, M.
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- 2013
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18. 9332 POSTER Efficacy and Feasibility of Combined Irinotecan and Cisplatin Therapy for Extrapulmonary Small Cell Carcinomas
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Nakano, K., Yuasa, T., Nishimura, N., Mishima, Y., Sakajiri, S., Yokoyama, M., and Takahashi, S.
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- 2011
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19. Intervertebral disc development is regulated by Wnt/β-catenin signaling.
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Kondo N, Yuasa T, Shimono K, Tung W, Okabe T, Yasuhara R, Pacifici M, Zhang Y, Iwamoto M, Enomoto-Iwamoto M, Kondo, Naoki, Yuasa, Takahito, Shimono, Kengo, Tung, Weien, Okabe, Takahiro, Yasuhara, Rika, Pacifici, Maurizio, Zhang, Yejia, Iwamoto, Masahiro, and Enomoto-Iwamoto, Motomi
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Study Design: Histologic analysis of intervertebral disc (IVD) in three types of transgenic mice.Objective: To investigate the role of Wnt/β-catenin signaling in regulation of IVD development and organization.Summary Of Background Data: β-catenin dependent Wnt signaling is one of the central regulators in cartilage development during limb skeletal formation. Little is known, however, about the physiologic relevance of this signaling pathway to IVD development and organization.Methods: Temporal-spatial distribution of Wnt/β-catenin signaling activity was examined in IVD using Wnt/β-catenin reporter (TOPGAL) mice. The structural changes in the mouse IVD components such as the nucleus pulposus (NP), endplate (EP), annulus fibrosus (AF), and the growth plate (GP) of the vertebral body were analyzed after transient activation of Wnt/β-catenin signaling or deletion of β-catenin in the mice.Results: Activity of Wnt/β-catenin signaling was high in EP, AF, and GP in the embryonic stages and decreased at the postnatal stage; it was undetectable in the embryonic NP but upregulated after birth. The transient activation of Wnt/β-catenin signaling caused severe deterioration of the GP and the AF, whereas deficiency of β-catenin accelerated bone formation in between EP and GP.Conclusion: The findings in this study suggest that proper regulation of Wnt/β-catenin signaling is required for development and organization of IVD. [ABSTRACT FROM AUTHOR]- Published
- 2011
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20. A genetic polymorphism of the osteoprotegerin gene is associated with an increased risk of advanced prostate cancer.
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Narita N, Yuasa T, Tsuchiya N, Kumazawa T, Narita S, Inoue T, Ma Z, Saito M, Horikawa Y, Satoh S, Ogawa O, Habuchi T, Narita, Naofumi, Yuasa, Takeshi, Tsuchiya, Norihiko, Kumazawa, Teruaki, Narita, Shintaro, Inoue, Takamitsu, Ma, Zhiyong, and Saito, Mitsuru
- Abstract
Background: The purpose of this study was to evaluate the role of osteoprotegerin gene (OPG) polymorphisms as genetic modifiers in the etiology of prostate cancer (PCa) and disease progression.Methods: Three hundred and sixty one patients with PCa and 195 normal controls were enrolled in the study, and two genetic polymorphisms, 149 T/C and 950 T/C in the putative promoter region of OPG, were genotyped.Results: There was no significant difference in the genotype frequencies between PCa patients and controls (P = 0.939 and 0.294 for 149 T/C and 950 T/C polymorphisms, respectively). However, those patients with TC and TT genotypes in the 950 T/C polymorphism had a significantly increased risk of extraprostatic (age-adjusted odds ratio; aOR = 1.74 and 2.03 for TC and TT genotypes compared with the CC genotype, P = 0.028) and metastatic disease (aOR = 1.72 and 2.76 for TC and TT genotypes compared with the CC genotype, P = 0.009) compared with those with the CC genotype. In addition, analysis of the metastatic PCa patients (Stage D) showed that the presence of the T allele of the OPG 950 T/C polymorphism was an independent risk factor predicting survival by Cox proportional hazard regression analyses (P = 0.031).Conclusion: Progression of PCa may be influenced by an intrinsic genetic factor of the host's bone metabolism. The variant C allele of 950 T/C in the OPG promoter may play a major role as a genetic safe guard against progression in patients with PCa. [ABSTRACT FROM AUTHOR]- Published
- 2008
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21. P129 - Prognostic significance of body mass index in patients with metastatic renal cell carcinoma treated with first-line therapies.
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Sato, K., Takemura, K., Oki, R., Urasaki, T., Yoneoka, Y., Fujiwara, R., Yasuda, Y., Oguchi, T., Numao, N., Yamamoto, S., Yonese, J., and Yuasa, T.
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BODY mass index , *RENAL cell carcinoma , *METASTASIS - Published
- 2024
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22. Characteristics of Low‐Frequency Pulses Associated With Downward Terrestrial Gamma‐Ray Flashes.
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Wada, Y., Morimoto, T., Nakamura, Y., Wu, T., Enoto, T., Nakazawa, K., Ushio, T., Yuasa, T., and Tsuchiya, H.
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THUNDERSTORMS , *LIGHTNING , *STATISTICAL correlation , *GAMMA rays - Abstract
Winter thunderstorms in Japan have been recognized as an ideal target to observe high‐energy atmospheric phenomena thanks to low‐charge‐center cloud structures. During four winter seasons in Japan (from 2016 October to 2020 March), seven downward terrestrial gamma‐ray flashes (TGFs) were detected by gamma‐ray and broadband low‐frequency (LF: 0.8–500 kHz) monitors. All the detected TGFs took place at the initial stage of lightning flashes. Based on the LF observation, the seven downward TGFs in the present study can be classified into two types: energetic‐bipolar and small‐bipolar types. Three of them are energetic‐bipolar events, coincident with a high peak‐current LF pulse that originates from a negative return stroke with a peak current larger than 100 kA. The others are small‐bipolar events, followed by a negative bipolar LF pulse with a moderate peak current. Three of the four small‐bipolar events are multi‐pulse TGFs, while all of the energetic‐bipolar events in this study are single‐pulse TGFs. Plain Language Summary: Terrestrial gamma‐ray flashes (TGFs) are a transient high‐energy emission from lightning discharges. While a lot of upward TGFs have been detected by satellites, a few downward TGF have been detected by ground‐based experiments. Our detection network in Japan has detected seven downward TGFs in winter thunderstorms for 4 years. Lightning discharges associated with the downward TGFs were also monitored in the low‐frequency radio band. The low‐frequency pulses associated with the downward TGFs can be classified into two types. Correlation analysis of downward TGFs with gamma‐ray and low‐frequency observations is a powerful approach to reveal the production mechanism of TGFs. Key Points: Downward terrestrial gamma‐ray flashes (TGFs) in winter thunderstorms of Japan can be classified into two types based on low‐frequency (LF) observationsThree events were single‐pulse TGFs coincident with high peak‐current LF pulses of return strokesFour events were followed by moderate peak‐current LF pulses, and three of them are multi‐pulse TGFs [ABSTRACT FROM AUTHOR]
- Published
- 2022
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23. Chronic inflammatory demyelinating polyneuropathy in a patient with hyperIgEaemia
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Kimura, A., Yoshino, H., and Yuasa, T.
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IMMUNOGLOBULIN E , *DEMYELINATION , *ALLERGIES , *CEREBROSPINAL fluid , *NEUROPATHY - Abstract
Abstract: We herein report the case of a 46 year old man with chronic inflammatory demyelinating polyneuropathy (CIDP) with hyperIgEaemia. The patient presented with bilateral weakness, generalized hyporeflexia, and mild paresthesia of the fingers of both hands. Nerve conduction studies revealed multiple sites of motor conduction block in the absence of sensory abnormalities. Muscle strength increased, as did compound muscle action potential (CMAP) amplitude immediately after the intravenous infusion of immunoglobulin (IVIg). Serum IgE levels also fluctuated in parallel with his relapsing–remitting clinical course. We propose that pure motor CIDP may be immune mediated and suggest that IgE-mediated allergy may be one potential cause of this condition. [Copyright &y& Elsevier]
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- 2005
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24. Microstructure of TFA-MOD superconductor film on metal tape
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Kato, T., Araki, T., Yuasa, T., Iijima, Y., Saitoh, T., Hirayama, T., Yamada, Y., and Hirabayashi, I.
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SUPERCONDUCTORS , *TRANSMISSION electron microscopy - Abstract
Superconductor film of YBa2Cu3O
7−δ having high-Jc values was formed on a CeO2/YSZ buffered metal tape by the metal-organic deposition using trifluoroacetates (TFA-MOD) method. Transmission electron microscopy (TEM) confirmed the presence of microstructures of multi-layered structure of YBCO/CeO2/YSZ/Ni-based alloy. The thickness of each thin film YBCO, CeO2 and YSZ, was estimated to be 0.2, 0.5 and 1.3μ m, respectively. Both the film of YSZ on polycrystalline and the film of CeO2 on the YSZ film were composed of columnar grains aligned〈1 0 0〉 direction. The columnar structure of the CeO2 film was strongly correlated to that of the structure of YSZ film. While highly oriented YBCO film was formed on the CeO2 film, it was not dense and had a rough surface. TEM-EDS revealed copper oxide in the film of YBCO and secondary phase produced from YBCO and CeO2 (BaCeO3) between the two layers. [Copyright &y& Elsevier]- Published
- 2002
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25. Dip-coated YBa2Cu3O<f>7−x</f> film by metalorganic deposition using trifluoroacetate
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Araki, T., Kurosaki, H., Yuasa, T., Iijima, Y., Saitoh, T., Yamada, Y., and Hirabayashi, I.
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SURFACE coatings , *ACETATES - Abstract
Metalorganic deposition using trifluoroacetates (TFA-MOD) with dip coating was applied for the preparation of YBCO coated conductor. The thickness of the dip-coated films increases with the 0.364th power of the withdrawal speed of substrates. This relationship is common to the case on either single crystal or metal substrate. A 3 cm long dipped YBCO tape on CeO2/YSZ(IBAD)/hastelloy-C is formed at a 5 mm/s withdrawal speed. The tape of 2000 A˚ in thickness has
Jc of 1.0–1.3 MA/cm2 (77 K, 0 T) measured by the four-probe-method. [Copyright &y& Elsevier]- Published
- 2002
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26. Meteorological Aspects of Gamma‐Ray Glows in Winter Thunderstorms.
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Wada, Y., Enoto, T., Kubo, M., Nakazawa, K., Shinoda, T., Yonetoku, D., Sawano, T., Yuasa, T., Ushio, T., Sato, Y., Diniz, G. S., and Tsuchiya, H.
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HAILSTORMS , *THUNDERSTORMS , *ATMOSPHERIC temperature measurements , *ATMOSPHERIC physics , *WINTER , *CUMULONIMBUS - Abstract
During three winter seasons from November 2016 to March 2019, 11 gamma‐ray glows were detected at a single observation site of our ground‐based gamma‐ray monitoring network in Kanazawa, Japan. These events are analyzed with observations of an X‐band radar network, a ceilometer, a disdrometer, and a weather monitor. All the detected glows were connected to convective high‐reflectivity regions of more than 35 dBZ, developed up to an altitude of >2 km. They were also accompanied by heavy precipitation of graupels. Therefore, graupels in the lower layer of thunderclouds that correspond to high‐reflectivity regions can form strong electric fields producing gamma‐ray glows. Also, these events are compared with a limited sample of nondetection cases, but no significant differences in meteorological conditions were found between detection and nondetection cases in the present study. Plain Language Summary: Strong electric fields inside thunderclouds can accelerate electrons to relativistic energies, and gamma‐ray photons from the accelerated electrons can be observed as minute‐lasting "gamma‐ray glows." During winter thunderstorms in Japan, we detected eleven gamma‐ray glows at sea level. The observations were combined with meteorological measurements such as atmospheric temperature, cloud bases, types of precipitation particles, and radar‐echo measurements. All the detected gamma‐ray glows were taking place during a passage of tall and well‐developed radar‐echo regions, and accompanied by heavy precipitation of graupel/hail pellets. The graupel/hail particles in the lower layer of thunderclouds could have contributed to gamma‐ray glows production. Key Points: Eleven gamma‐ray glows were observed during three winter seasons at a single observation site in JapanAll the detected gamma‐ray glows were associated with tall and well‐developed radar‐echo structures of thunderstormsGraupel pallets in the lower layer of thunderclouds could be related to downward electron acceleration for the gamma‐ray glows [ABSTRACT FROM AUTHOR]
- Published
- 2021
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27. Chemically enhanced focused ion beam etching of deep grooves and laser-mirror facets in GaAs under Cl2 gas irradiation using a fine nozzle.
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Takado, N., Asakawa, K., Yuasa, T., Sugata, S., Miyauchi, E., Hashimoto, H., and Ishii, M.
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GALLIUM arsenide , *CHLORINE , *ION bombardment , *OPTOELECTRONICS , *INTEGRATED circuits - Abstract
Chlorine-enhanced GaAs maskless etching has been performed with a novel focused ion beam etching (FIBE) system. The system is composed of an air-locked ultrahigh vacuum chamber, a 30-keV Ga+ FIB column, and a fine nozzle. The nozzle irradiates a high-density Cl2 flux on a desired, small area of the sample while retaining a sufficiently low surrounding gas pressure for stable Ga+ FIB emission. Condensed Ga residues, appearing on the etched surface with no Cl2 gas, could be suppressed under Cl2 gas irradiation. Highly chemically enhanced sputtering yields (up to 50 GaAs molecules per incident ion) were obtained by selecting the optimum relationship between scanning time and Cl2 gas pressure. At the maximum yield, a deep groove (about 6 μm) with a smooth surface was obtained by line-scanning FIBE. The etching was applied to laser-mirror formation of an AlGaAs laser. A vertical mirror facet, fabricated in advance by a reactive ion beam etching, was trimmed about one micron thick by line-scanning FIBE. Light output versus current characteristics did not change before and after FIBE and the etching has been shown to be useful for laser-mirror formation. [ABSTRACT FROM AUTHOR]
- Published
- 1987
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28. Real-world outcomes of nivolumab and cabozantinib in metastatic renal cell carcinoma: results from the International Metastatic Renal Cell Carcinoma Database Consortium.
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Stukalin, I., Wells, J. C., Graham, J., Yuasa, T., Beuselinck, B., Kollmansberger, C., Ernst, D. S., Agarwal, N., Le, T., Donskov, F., Hansen, A. R., Bjarnason, G. A., Srinivas, S., Wood, L. A., Alva, A. S., Kanesvaran, R., Fu, S. Y. F., Davis, I. D., Choueiri, T. K., and Heng, D. Y. C.
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RENAL cell carcinoma , *VASCULAR endothelial growth factor receptors - Abstract
Objectives In the present study, we explored the real-world efficacy of the immuno-oncology checkpoint inhibitor nivolumab and the tyrosine kinase inhibitor cabozantinib in the second-line setting. Methods Using the International Metastatic Renal Cell Carcinoma Database Consortium (imdc) dataset, a retrospective analysis of patients with metastatic renal cell carcinoma (mrcc) treated with nivolumab or cabozantinib in the second line after prior therapy targeted to the vascular endothelial growth factor receptor (vegfr) was performed. Baseline characteristics and imdc risk factors were collected. Overall survival (os) and time to treatment failure (ttf) were calculated using Kaplan-Meier curves. Overall response rates (orrs) were determined for each therapy. Multivariable Cox regression analysis was performed to determine survival differences between cabozantinib and nivolumab treatment. Results The analysis included 225 patients treated with nivolumab and 53 treated with cabozantinib. No significant difference in median os was observed: 22.10 months [95% confidence interval (ci): 17.18 months to not reached] with nivolumab and 23.70 months (95% ci: 15.52 months to not reached) with cabozantinib (p = 0.61). The ttf was also similar at 6.90 months (95% ci: 4.60 months to 9.20 months) with nivolumab and 7.39 months (95% ci: 5.52 months to 12.85 months) with cabozantinib (p = 0.20). The adjusted hazard ratio (hr) for nivolumab compared with cabozantinib was 1.30 (95% ci: 0.73 to 2.3), p = 0.38. When adjusted by imdc criteria and age, the hr was 1.32 (95% ci: 0.74 to 2.38), p = 0.35. Conclusions Real-world imdc data indicate comparable os and ttf for nivolumab and cabozantinib. Both agents are reasonable therapeutic options for patients progressing after initial first-line vegfr-targeted therapy. [ABSTRACT FROM AUTHOR]
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- 2019
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29. A0326 - Characterization of patients with metastatic renal cell carcinoma treated with or without cytoreductive nephrectomy in the era of combination immunotherapy: Results from the International Metastatic Renal Cell Carcinoma Database Consortium (IMDC).
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Takemura, K., Ernst, M., Navani, V., Wells, J.C., Bakouny, Z., Donskov, F., Basappa, N.S., Wood, L.A., Meza, L., Pal, S.K., Szabados, B., Powles, T., Beuselinck, B., Mckay, R.R., Lee, J-L., Ernst, D.S., Kapoor, A., Yuasa, T., Choueiri, T.K., and Heng, D.Y.C.
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RENAL cell carcinoma , *DATABASES , *NEPHRECTOMY , *METASTASIS , *IMMUNOTHERAPY - Published
- 2023
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30. Termination of Electron Acceleration in Thundercloud by Intracloud/Intercloud Discharge.
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Wada, Y., Bowers, G. S., Enoto, T., Kamogawa, M., Nakamura, Y., Morimoto, T., Smith, D. M., Furuta, Y., Nakazawa, K., Yuasa, T., Matsuki, A., Kubo, M., Tamagawa, T., Makishima, K., and Tsuchiya, H.
- Abstract
Abstract: An on‐ground observation program for high‐energy atmospheric phenomena in winter thunderstorms along the Japan Sea has been performed via measurements of gamma ray radiation, atmospheric electric field, and low‐frequency radio band. On 11 February 2017, the radiation detectors recorded gamma ray emission lasting for 75 s, and then abruptly terminated with a nearby lightning discharge. The gamma ray spectrum extended up to 20 MeV and was reproduced by a cutoff power law model with a photon index of 1 . 3 6 − 0 . 04 + 0 . 03, being consistent with Bremsstrahlung radiation from a thundercloud (known as a gamma‐ray glow or a thunderstorm ground enhancement). The low‐frequency radio monitors, installed ∼50 km away from the gamma ray observation site recorded leader development of an intracloud/intercloud discharge spreading over ∼60 km area with a ∼300‐ms duration. The timing of the gamma ray termination coincided with the moment when the leader development of the intracloud/intercloud discharge passed 0.7 km horizontally away from the radiation monitors. The intracloud/intercloud discharge started ∼15 km away from the gamma ray observation site. Therefore, the glow was terminated by the leader development, while it did not trigger the lightning discharge in the present case. [ABSTRACT FROM AUTHOR]
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- 2018
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31. 1455P Characterization of patients with metastatic renal cell carcinoma achieving complete response to first-line therapies: Results from the international metastatic renal cell carcinoma database consortium (IMDC).
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Takemura, K., Navani, V., Ernst, M.S., Wells, J.C., Choueiri, T.K., Meza, L., Pal, S.K., Lee, J-L., Li, H., Agarwal, N., Alva, A.S., Hansen, A.R., Basappa, N.S., Szabados, B.E., Powles, T.B., Tran, B., Hocking, C.M., Beuselinck, B., Yuasa, T., and Heng, D.Y.C.
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RENAL cell carcinoma , *METASTASIS , *TREATMENT effectiveness , *DATABASES - Published
- 2022
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32. Synchrotron-based XRD from rat bone of different age groups.
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Rao, D.V., Gigante, G.E., Cesareo, R., Brunetti, A., Schiavon, N., Akatsuka, T., Yuasa, T., and Takeda, T.
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BONE growth , *SYNCHROTRONS , *X-ray powder diffraction , *HYDROXYAPATITE , *SCANNING electron microscopy ,RAT anatomy - Abstract
Synchrotron-based XRD spectra from rat bone of different age groups (w, 56 w and 78w), lumber vertebra at early stages of bone formation, Calcium hydroxyapatite (HAp) [Ca 10 (PO 4 ) 6 (OH) 2 ] bone fill with varying composition (60% and 70%) and bone cream (35–48%), has been acquired with 15 keV synchrotron X-rays. Experiments were performed at Desy, Hamburg, Germany, utilizing the Resonant and Diffraction beamline (P9), with 15 keV X-rays (λ = 0.82666 A 0 ). Diffraction data were quantitatively analyzed using the Rietveld refinement approach, which allowed us to characterize the structure of these samples in their early stages. Hydroxyapatite, received considerable attention in medical and materials sciences, since these materials are the hard tissues, such as bone and teeth. Higher bioactivity of these samples gained reasonable interest for biological application and for bone tissue repair in oral surgery and orthopedics. The results obtained from these samples, such as phase data, crystalline size of the phases, as well as the degree of crystallinity, confirm the apatite family crystallizing in a hexagonal system, space group P6 3 /m with the lattice parameters of a = 9.4328 Å and c = 6.8842 Å (JCPDS card #09-0432). Synchrotron-based XRD patterns are relatively sharp and well resolved and can be attributed to the hexagonal crystal form of hydroxyapatite. All the samples were examined with scanning electron microscope at an accelerating voltage of 15 kV. The presence of large globules of different sizes is observed, in small age groups of the rat bone (8w) and lumber vertebra (LV), as distinguished from, large age groups (56 and 78w) in all samples with different magnification, reflects an amorphous phase without significant traces of crystalline phases. Scanning electron microscopy (SEM) was used to characterize the morphology and crystalline properties of Hap, for all the samples, from 2 to 100 μm resolution. [ABSTRACT FROM AUTHOR]
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- 2017
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33. 3159: Diagnosis of ischemic heart disease by detecting post ischemic regional left ventricular delayed relaxation following treadmill stress echocardiography with color kinesis
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Nakashiki, K., Otsuji, Y., Yuasa, T., Kuwahara, E., Uemura, T., Takasaki, K., Kubota, K., Mizukami, N., Ishii, K., Kisanuki, A., and Tei, C.
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- 2006
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34. Synchrotron-based crystal structure, associated morphology of snail and bivalve shells by X-ray diffraction.
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Rao, D.V., Gigante, G.E., Kumar, Y. Manoj, Cesareo, R., Brunetti, A., Schiavon, N., Akatsuka, T., Yuasa, T., and Takeda, T.
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SYNCHROTRON radiation , *CRYSTAL structure , *CRYSTAL morphology , *X-ray diffraction , *CALCIUM carbonate , *SCANNING electron microscopy - Abstract
Synchrotron-based high-resolution X-ray powder diffraction spectra from the body parts of a snail and bivalve (CaCO 3 ), have been recorded with Pilatus area detector. Experiments were performed at Desy, Hamburg, Germany, utilizing the Resonant and Diffraction beamline (P9), with 15 keV X-rays (λ=0.82666 Å). The external shell of these living organisms, is composed of calcium carbonate, which carries strong biological signal. It consists of some light elements, such as, Ca, C and O, which constitute part of the soft tissue and other trace elements. The knowledge of these diffraction patterns and hence the understanding of structures at molecular level are enormous. The application of synchrotron radiation to powder diffraction is well suited for samples of biological nature via changes in their patterns and also to investigate crystallographic phase composition. With the use of Rietveld refinement procedure, to the high-resolution diffraction spectra, we were able to extract the lattice parameters of orthorhombic polymorph of CaCO 3 , the most abundant mineral produced by these living organisms. The small size of the crystallite is a very important factor related to the biological structure. The natural model presents a combination of organic and inorganic phases with nanometer size. For the present study, we also used the scanning electron microscopy (SEM) to explore the associated morphology of the snail and bivalve. [ABSTRACT FROM AUTHOR]
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- 2016
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35. X-ray System for Early Diagnosis of Breast Cancer.
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Ando, M., Maksimenko, A., Ichihara, S., Endo, T., Moriyama, N., Yuasa, T., Hashimoto, E., Sugiyama, H., Li, G., and Hyodo, K.
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BREAST cancer , *CANCER in women , *MAMMOGRAMS , *DIAGNOSTIC imaging , *BREAST exams - Abstract
Increasing rate of breast cancer in Japan is enormous in these years. Nevertheless only 2–3 % of female may receive mammography. In order to improve this number for early detection of breast cancer we have started development of a refraction-based visualization of breast cancer. This system comprises two types of imaging: one is for a regular annual or biyearly check of the breast cancer. This is a 2-D mode x-ray dark-field imaging where a Laue transmission type of angle analyzer with thickness of 2.124 mm is used for the FOV of 90 mm × 90 mm that can provide the spatial resolution better than 50 microns; the other a 3-D reconstruction for further detailed check to specify type and location of breast cancer. © 2007 American Institute of Physics [ABSTRACT FROM AUTHOR]
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- 2007
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36. In-vivo Fluorescent X-ray CT Imaging of Mouse Brain.
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Takeda, T., Wu, J., Lwin, Thet-Thet, Huo, Q., Sunaguchi, N., Murakami, T., Mouri, S., Nasukawa, S., Yuasa, T., Hyodo, K., Hontani, H., Minami, M., and Akatsuka, T.
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BRAIN , *TOMOGRAPHY , *X-rays , *IODINE , *BASAL ganglia , *MEDICAL imaging systems , *LABORATORY mice - Abstract
Using a non-radioactive iodine-127 labeled cerebral perfusion agent (I-127 IMP), fluorescent X-ray computed tomography (FXCT) clearly revealed the cross-sectional distribution of I-127 IMP in normal mouse brain in-vivo. Cerebral perfusion of cortex and basal ganglion was depicted with 1 mm in-plane spatial resolution and 0.1 mm slice thickness. Degree of cerebral perfusion in basal ganglion was about 2-fold higher than that in cortical regions. This result suggests that in-vivo cerebral perfusion imaging is realized quantitatively by FXCT at high volumetric resolution. © 2007 American Institute of Physics [ABSTRACT FROM AUTHOR]
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- 2007
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37. Validity of Fusion Imaging of Hamster Heart obtained by Fluorescent and Phase-Contrast X-Ray CT with Synchrotron Radiation.
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Wu, J., Takeda, T., Lwin, Thet Thet, Huo, Q., Sunaguchi, N., Murakami, T., Mouri, S., Nasukawa, S., Fukami, T., Yuasa, T., Hyodo, K., Hontani, H., Minami, M., and Akatsuka, T.
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CARDIOMYOPATHIES , *TOMOGRAPHY , *SYNCHROTRON radiation , *HAMSTERS as laboratory animals , *VETERINARY diagnosis , *X-rays , *DIAGNOSIS - Abstract
Fluorescent X-ray CT (FXCT) to depict functional information and phase-contrast X-ray CT (PCCT) to demonstrate morphological information are being developed to analyze the disease model of small animal. To understand the detailed pathological state, integration of both functional and morphological image is very useful. The feasibility of image fusion between FXCT and PCCT were examined by using ex-vivo hearts injected fatty acid metabolic agent (127I-BMIPP) in normal and cardiomyopathic hamsters. Fusion images were reconstructed from each 3D image of FXCT and PCCT. 127I-BMIPP distribution within the heart was clearly demonstrated by FXCT with 0.25 mm spatial resolution. The detailed morphological image was obtained by PCCT at about 0.03 mm spatial resolution. Using image integration technique, metabolic abnormality of fatty acid in cardiomyopathic myocardium was easily recognized corresponding to anatomical structures. Our study suggests that image fusion provides important biomedical information even in FXCT and PCCT imaging. © 2007 American Institute of Physics [ABSTRACT FROM AUTHOR]
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- 2007
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38. High Quality Image of Biomedical Object by X-ray Refraction Based Contrast Computed Tomography.
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Hashimoto, E., Maksimenko, A., Sugiyama, H., Hirano, K., Hyodo, K., Shimao, D., Nishino, Y., Ishikawa, T., Yuasa, T., Ichihara, S., Arai, Y., and Ando, M.
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X-ray refraction , *TOMOGRAPHY , *ALGORITHMS , *OPTICAL diffraction , *X-rays , *CANCER - Abstract
Recently we have developed a new Computed Tomography (CT) algorithm for refraction contrast that uses the optics of diffraction-enhanced imaging. We applied this new method to visualize soft tissue which is not visualized by the current absorption based contrast. The meaning of the contrast that appears in refraction-contrast X-ray CT images must be clarified from a biologic or anatomic point of view. It has been reported that the contrast is made with the specific gravity map with a range of approximately 10 μarc sec. However, the relationship between the contrast and biologic or anatomic findings has not been investigated, to our knowledge. We compared refraction-contrast X-ray CT images with microscopic X-ray images, and we evaluated refractive indexes of pathologic lesions on phase-contrast X-ray CT images. We focused our attenuation of breast cancer and lung cancer as samples. X-ray refraction based Computed Tomography was appeared to be a pathological ability to depict the boundary between cancer nest and normal tissue, and inner structure of the disease. © 2007 American Institute of Physics [ABSTRACT FROM AUTHOR]
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- 2007
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39. A Novel and Simple X-Ray Dark Field Imaging.
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Hashimoto, E., Sugiyama, H., Maksimenko, A., Hyodo, K., Yuasa, T., Pattanasiriwisawa, W., Rubenstein, E., Roberson, Joseph, Ando, M., and Warwick, T.
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X-ray optics , *MEDICAL imaging systems , *MONOCHROMATORS , *OPTICAL diffraction , *OPTICAL resolution , *CRYSTALS - Abstract
A novel and simple X ray optics ‘Owl’ capable of dark field imaging due to refraction contrast is under developement. That comprises a Bragg case asymmetric monochromator ‘M’ and an analyzer ‘A’ in a double crystal arrangement. ‘A’ has thickness of N × L, where N means integer and L the extinction distance in the Laue case or has a thickness that should provide reasonable transmittant X-ray intensity in the Bragg case. The analyzer can only select the refracted light from object towards the forward diffraction direction, while completely suppresses the intensity toward the diffraction direction at the just Bragg position. Their angular width of diffraction was 0.3 μrad at X-ray energy of 35keV. The spatial resolution available is at the order of 5μm or better. This method has a large potential of application to material science, biology and clinical medicine. Pictures shown as demonstration of dark field imaging is a ceramics with hexagonal outer size of 5 mm, containing 91 holes with diameter of 300μm and human auditory ossicles excised. © 2004 American Institute of Physics [ABSTRACT FROM AUTHOR]
- Published
- 2004
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40. Development of High-Speed Fluorescent X-Ray Micro-Computed Tomography.
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Takeda, T., Tsuchiya, Y., Kuroe, T., Zeniya, T., Wu, J., Thet-Thet-Lwin, Yashiro, T., Yuasa, T., Hyodo, K., Matsumura, K., Dilmanian, F. A., Itai, Y., Akatsuka, T., and Warwick, T.
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TOMOGRAPHY , *X-ray spectroscopy , *X-rays , *MEDICAL imaging systems , *BIOMEDICAL engineering , *IODINE - Abstract
A high-speed fluorescent x-ray CT (FXCT) system using monochromatic synchrotron x rays was developed to detect very low concentration of medium-Z elements for biomedical use. The system is equipped two types of high purity germanium detectors, and fast electronics and software. Preliminary images of a 10mm diameter plastic phantom containing channels field with iodine solutions of different concentrations showed a minimum detection level of 0.002 mg I/ml at an in-plane spatial resolution of 100μm. Furthermore, the acquisition time was reduced about 1/2 comparing to previous system. The results indicate that FXCT is a highly sensitive imaging modality capable of detecting very low concentration of iodine, and that the method has potential in biomedical applications. © 2004 American Institute of Physics [ABSTRACT FROM AUTHOR]
- Published
- 2004
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41. First-, second-, third-line therapy for mRCC: benchmarks for trial design from the IMDC.
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Ko, J J, Choueiri, T K, Rini, B I, Lee, J-L, Kroeger, N, Srinivas, S, Harshman, L C, Knox, J J, Bjarnason, G A, MacKenzie, M J, Wood, L, Vaishampayan, U N, Agarwal, N, Pal, S K, Tan, M-H, Rha, S Y, Yuasa, T, Donskov, F, Bamias, A, and Heng, D Y C
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RENAL cell carcinoma , *CANCER invasiveness , *CLINICAL trials , *THERAPEUTICS , *CLINICAL medicine - Abstract
Background:Limited data exist on outcomes for metastatic renal cell carcinoma (mRCC) patients treated with multiple lines of therapy. Benchmarks for survival are required for patient counselling and clinical trial design.Methods:Outcomes of mRCC patients from the International mRCC Database Consortium database treated with 1, 2, or 3+ lines of targeted therapy (TT) were compared by proportional hazards regression. Overall survival (OS) and progression-free survival (PFS) were calculated using different population inclusion criteria.Results:In total, 2705 patients were treated with TT of which 57% received only first-line TT, 27% received two lines of TT, and 16% received 3+ lines of TT. Overall survival of patients who received 1, 2, or 3+ lines of TT were 14.9, 21.0, and 39.2 months, respectively, from first-line TT (P<0.0001). On multivariable analysis, 2 lines and 3+ lines of therapy were each associated with better OS (HR=0.738 and 0.626, P<0.0001). Survival outcomes for the subgroups were as follows: for all patients, OS 20.9 months and PFS 7.2 months; for those similar to eligible patients in the first-line ADAPT trial, OS 14.7 months and PFS 5.6 months; for those similar to patients in first-line TIVO-1 trial, OS 24.8 months and PFS 8.2 months; for those similar to patients in second-line INTORSECT trial, OS 13.0 months and PFS 3.9 months; and for those similar to patients in the third-line GOLD trial, OS 18.0 months and PFS 4.4 months.Conclusions:Patients who are able to receive more lines of TT live longer. Survival benchmarks provide context and perspective when interpreting and designing clinical trials. [ABSTRACT FROM AUTHOR]
- Published
- 2014
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42. Outcomes of patients with metastatic renal cell carcinoma that do not meet eligibility criteria for clinical trials.
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Heng, D. Y. C., Choueiri, T. K., Rini, B. I., Lee, J., Yuasa, T., Pal, S. K., Srinivas, S., Bjarnason, G. A., Knox, J. J., MacKenzie, M., Vaishampayan, U. N., Tan, M. H., Rha, S. Y., Donskov, F., Agarwal, N., Kollmannsberger, C., North, S., and Wood, L. A.
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RENAL cell carcinoma , *METASTASIS , *VASCULAR endothelial growth factors , *MEDICAL statistics , *HEALTH outcome assessment , *COHORT analysis , *CLINICAL trials - Abstract
This study focuses on the outcomes of a large international cohort of patients with metastatic RCC who would not have met the eligibility criteria for clinical trials and compares these to those that would have eligible. The proportion of patients who would have been ineligible and the reason for ineligibility are also discussed.Background Targeted therapies in metastatic renal cell carcinoma (mRCC) have been approved based on registration clinical trials that have strict eligibility criteria. The clinical outcomes of patients treated with targeted agents but are ineligible for trials are unknown. Patients and Methods mRCC patients treated with vascular endothelial growth factor-targeted therapy were retrospectively deemed ineligible for clinical trials (according to commonly used inclusion/exclusion criteria) if they had a Karnofsky performance status (KPS) <70%, nonclear-cell histology, brain metastases, hemoglobin ≤9 g/dl, creatinine >2× the upper limit of normal, corrected calcium ≥12 mg/dl, platelet count of <100 × 103/uL, or neutrophil count <1500/mm3. Results Overall, 768 of 2210 (35%) patients in the International Metastatic RCC Database Consortium (IMDC) were deemed ineligible for clinical trials by the above criteria. Between ineligible versus eligible patients, the response rate, median progression-free survival (PFS) and median overall survival of first-line targeted therapy were 22% versus 29% (P = 0.0005), 5.2 versus 8.6 months, and 12.5 versus 28.4 months (both P < 0.0001), respectively. Second-line PFS (if applicable) was 2.8 months in the trial ineligible versus 4.3 months in the trial eligible patients (P = 0.0039). When adjusted by the IMDC prognostic categories, the HR for death between trial ineligible and trial eligible patients was 1.55 (95% confidence interval 1.378–1.751, P < 0.0001). Conclusions The number of patients that are ineligible for clinical trials is substantial and their outcomes are inferior. Specific trials addressing the unmet needs of protocol ineligible patients are warranted. [ABSTRACT FROM AUTHOR]
- Published
- 2014
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43. Development of microwave kinetic inductance detectors and their readout system for LiteBIRD.
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Hattori, K., Hazumi, M., Ishino, H., Kibayashi, A., Kibe, Y., Mima, S., Okamura, T., Sato, N., Tomaru, T., Yamada, Y., Yoshida, M., Yuasa, T., and Watanabe, H.
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COSMIC background radiation , *GRAVITATIONAL waves , *INFLATIONARY universe , *POLARIZATION (Nuclear physics) , *SUPERCONDUCTORS , *SURFACE impedance , *ANTENNAS (Electronics) - Abstract
Abstract: Primordial gravitational waves generated by inflation have produced an odd-parity pattern B-mode in the cosmic microwave background (CMB) polarization. LiteBIRD (Light satellite for the studies of B-mode polarization and Inflation from cosmic background Radiation Detection) aims at detecting this B-mode polarization precisely. It requires about 2000 detectors capable of detecting a frequency range from 50GHz to 250GHz with ultra low noise. Superconducting detectors are suitable for this requirement. We have fabricated and tested microwave kinetic inductance detectors (MKIDs) and developed a new readout system. We have designed antenna-coupled MKIDs. Quasi-particles are created by incident radiation and are detected as a change of the surface impedance of a superconductor strip. This change of the surface impedance is translated into the change of the resonant frequency of a microwave signal transmitted through the resonator. We also have developed a new readout system for MKIDs. The newly developed readout system is not only able to read out the amplitude and the phase data with the homodyne detection for multi-channels, but also provides a unique feature of tracking the resonant frequency of the target resonator. This mechanism enables us to detect signals with a large dynamic range. We report on the recent R&D status of the developing MKIDs and on the read-out system for LiteBIRD. [Copyright &y& Elsevier]
- Published
- 2013
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44. Hardening and Termination of Long-Duration y Rays Detected Prior to Lightning.
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Tsuchiya, H., Enoto, T., Iwata, K., Yamada, S., Yuasa, T., Kitaguchi, T., Kawaharada, M., Nakazawa, K., Kokubun, M., Kato, H., Okano, M., Tamagawa, T., and Makishima, K.
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HARDENING (Heat treatment) , *GAMMA ray sources , *GAMMA ray detectors , *LIGHTNING , *THUNDERSTORMS - Abstract
We report the first observation of 3-30 MeV prolonged gamma-ray emission that was abruptly terminated by lightning. The gamma-ray detection was made during winter thunderstorms on December 30, 2010, by the Gamma-Ray Observation of Winter Thunderclouds experiment carried out in a coastal area along the Sea of Japan. The gamma-ray flux lasted for less than 3 min, continuously hardening closer to the lightning occurrence. The hardening at energies of 3-10 MeV energies was most prominent. The gamma-ray flux abruptly ceased less than 800 ms before the lightning flash that occurred over 5 km away from the experimental site. In addition, we observed a clear difference in the duration of the 3-10 MeV gamma rays and those >10 MeV, suggesting that the area of >10 MeV gamma-ray emission is considerably smaller than that of the lower-energy gamma rays. This work may give a manifestation that a local region emitting prolonged gamma rays connects with a distant region to initiate lightning. [ABSTRACT FROM AUTHOR]
- Published
- 2013
- Full Text
- View/download PDF
45. Geometry dependence of the light collection efficiency of BGO crystal scintillators read out by avalanche photo diodes.
- Author
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Sasano, M., Nishioka, H., Okuyama, S., Nakazawa, K., Makishima, K., Yamada, S., Yuasa, T., Okumura, A., Kataoka, J., Fukazawa, Y., Hanabata, Y., and Hayashi, K.
- Subjects
- *
AVALANCHE photodiodes , *ENERGY consumption , *ATTENUATION (Physics) , *MONTE Carlo method , *GEOMETRIC analysis , *CRYSTAL optics - Abstract
Abstract: Light collection efficiency from BGO crystal scintillators of various sizes and shapes was measured by reading them using 1×1cm2 avalanche photo diodes. When the crystals have simple geometry, the light collection efficiency was found to depend on their size, shape and the read-out position through a rather well-defined empirical scaling relation. The light collection efficiency of tapered crystals was seen to depend on both the position of irradiation, and the read-out position of the avalanche photo diodes. Using optical Monte-Carlo simulations, the relation was reproduced assuming plausible proper parameters for surface conditions and the attenuation length. This results were reproduced with a reasonable accuracy by optical Monte-Carlo simulations. Simple physical explanations are given to these geometrical effects. [Copyright &y& Elsevier]
- Published
- 2013
- Full Text
- View/download PDF
46. High Temperature-Induced Repression of the Rice Sucrose Transporter ( Os SUT1) and Starch Synthesis-Related Genes in Sink and Source Organs at Milky Ripening Stage Causes Chalky Grains.
- Author
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Phan, T. T. T., Ishibashi, Y., Miyazaki, M., Tran, H. T., Okamura, K., Tanaka, S., Nakamura, J., Yuasa, T., and Iwaya‐Inoue, M.
- Subjects
- *
PHYSIOLOGICAL effects of heat , *RICE , *SUCROSE , *STARCH synthesis , *PLANT genes , *RIPENING of grain , *GRAIN yields , *FLOWERING of plants - Abstract
High temperatures during rice grain ripening reduced yield and grain quality. The proportion of milky white grains was 43.6 % at 30 °C but only 6.5 % at 25 °C. Grain filling was initially faster at 30 °C and finished earlier, and the final dry matter content was less, than at 25 °C. High temperature strongly suppressed the expression of the sucrose transporter gene Os SUT1 and starch synthesis-related genes Su Sy2, AGPS2b, BEIIb and Granule-bound starch synthase in grains during early grain filling; the transcription levels of Os SUT1 at 14 days after flowering ( DAF) were about 60 % lower in grains, flag leaf blade, flag leaf sheath and first leaf sheath. These facts are possibly involved in the earlier termination of grain filling at 21 DAF, following the rapid rise of grain dry weight from 0 to 7 DAF, due to possible reduction in assimilate supply via Os SUT1 under the high temperature. When panicles were partly clipped, the resultant increase in assimilate supply to the remaining grains significantly upregulated the expression of Os SUT1 and the starch synthesis-related genes at 14 DAF, which consequently accelerated starch accumulation in the grains and ultimately increased the grain weight of remaining grains at 30 °C. These results indicate that high temperature during grain filling reduces grain yield and quality by changing the expression of Os SUT1 and starch synthase-related genes, resulting in earlier ripening due to hastened or premature assimilate supply to grains. [ABSTRACT FROM AUTHOR]
- Published
- 2013
- Full Text
- View/download PDF
47. Fermi-LAT and Suzaku observations of the radio galaxy Centaurus B.
- Author
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Katsuta, J., Tanaka, Y. T., Stawarz, Ł, O'Sullivan, S. P., Cheung, C. C., Kataoka, J., Funk, S., Yuasa, T., Odaka, H., Takahashi, T., and Svoboda, J.
- Subjects
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RADIO galaxies , *RADIO sources (Astronomy) , *ASTRONOMY , *DENSITY wave theory , *GALACTIC nuclei - Abstract
Centaurus B is a nearby radio galaxy positioned in the southern hemisphere close to the Galactic plane. Here we present a detailed analysis of about 43 months of accumulated Fermi-LAT data of the γ-ray counterpart of the source initially reported in the 2nd Fermi-LAT catalog, and of newly acquired Suzaku X-ray data. We confirm its detection at GeV photon energies and analyze the extension and variability of the γ-ray source in the LAT dataset, in which it appears as a steady γ-ray emitter. The X-ray core of Centaurus B is detected as a bright source of a continuum radiation. We do not detect, however, any diffuse X-ray emission from the known radio lobes, with the provided upper limit only marginally consistent with the previously claimed ASCA flux. Two scenarios that connect the X-ray and γ-ray properties are considered. In the first one, we assume that the diffuse non-thermal X-ray emission component is not significantly below the derived Suzaku upper limit. In this case, modeling the inverse-Compton emission shows that the observed γ-ray flux of the source may in principle be produced within the lobes. This association would imply that efficient in-situ acceleration of the radiating electrons is occurring and that the lobes are dominated by the pressure from the relativistic particles. In the second scenario, with the diffuse X-ray emission well below the Suzaku upper limits, the lobes in the system are instead dominated by the magnetic pressure. In this case, the observed γ-ray flux is not likely to be produced within the lobes, but instead within the nuclear parts of the jet. By means of synchrotron self-Compton modeling, we show that this possibility could be consistent with the broad-band data collected for the unresolved core of Centaurus B, including the newly derived Suzaku spectrum. [ABSTRACT FROM AUTHOR]
- Published
- 2013
- Full Text
- View/download PDF
48. Right ventricular outflow tract obstruction metastatic thyroid carcinoma.
- Author
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Yanagisawa S, Suzuki Y, Yuasa T, and Tanaka T
- Published
- 2010
- Full Text
- View/download PDF
49. Identification of anaplastic lymphoma kinase fusions in renal cancer: Large-scale immunohistochemical screening by the intercalated antibody-enhanced polymer method.
- Author
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Sugawara E, Togashi Y, Kuroda N, Sakata S, Hatano S, Asaka R, Yuasa T, Yonese J, Kitagawa M, Mano H, Ishikawa Y, and Takeuchi K
- Published
- 2012
- Full Text
- View/download PDF
50. Prognostic Impact of C-reactive Protein for Determining Overall Survival of Patients With Castration-resistant Prostate Cancer Treated With Docetaxel.
- Author
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Ito M, Saito K, Yasuda Y, Sukegawa G, Kubo Y, Numao N, Kitsukawa S, Urakami S, Yuasa T, Yamamoto S, Yonese J, and Fukui I
- Published
- 2011
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