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Search Results: 1 - 10 of 2677 matches for " Shigeki Kato "
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Numerical evidence of quantum melting of spin ice: quantum-classical crossover
Yasuyuki Kato,Shigeki Onoda
Physics , 2014, DOI: 10.1103/PhysRevLett.115.077202
Abstract: Unbiased quantum Monte-Carlo simulations are performed on the nearest-neighbor spin-$\frac{1}{2}$ pyrochlore XXZ model with an antiferromagnetic longitudinal and a weak ferromagnetic transverse exchange couplings, $J$ and $J_\perp$. The specific heat exhibits a broad peak at $T_{\mathrm{CSI}}\sim0.2J$ associated with a crossover to a classical Coulomb liquid regime showing a suppressed spin-ice monopole density, a broadened pinch-point singularity, and the Pauling entropy for $|J_\perp|\ll J$, as in classical spin ice. On further cooling, the entropy restarts decaying for $J_\perp>J_{\perp c}\sim-0.104J$, producing another broad specific heat peak for a crossover to a bosonic quantum Coulomb liquid, where the spin correlation contains both photon and quantum spin-ice monopole contributions. With negatively increasing $J_\perp$ across $J_{\perp c}$, a first-order thermal phase transition occurs from the quantum Coulomb liquid to an XY ferromagnet. Relevance to magnetic rare-earth pyrochlore oxides is discussed.
Clinical Analysis of Pulmonary Nontuberculous Mycobacterial Disease Diagnosed as Coincidental Pulmonary Infection Due to Mycobacterium Species*  [PDF]
Yoshihiro Kobashi, Keiji Mouri, Yasushi Obase, Shigeki Kato, Mikio Oka
Open Journal of Respiratory Diseases (OJRD) , 2013, DOI: 10.4236/ojrd.2013.32016
Abstract: Objectives: We analyzed the clinical characteristics of patients with pulmonary mycobacterial disease diagnosed as coincidental pulmonary infection due to Mycobacterium species. Materials and Methods: One hundred sixty patients satisfied the diagnostic criteria of nontuberculous mycobacterial disease proposed by American Thoracic Society during the last seven years. Six patients (3.8%) were coincidental pulmonary infection due to two Mycobacterium species. We investigated the background, laboratory findings, microbiological findings, radiological findings, treatment and prognosis. Results: There were six patients, 3 males and 3 females, with a mean age of 71.7 years. The causative microorganisms of coincidental pulmonary infection consisted of Mycobacterium avium + Mycobacterium intracellulare in two patients, Mycobacterium avium + Mycobacterium kansasii in one, Mycobacterium intracellulare + Mycobacterium chelonae in one, Mycobacterium intracellulare + Mycobacterium abscessus in one, and Mycobacterium intracellulare + Mycobacterium tuberculosis in one. Regarding the radiological findings, the distribution of the lesion was frequently shown in both the right middle and left lingula lobes, but the extent of the lesion was limited within the unilateral lung field. Centrilobular small nodules with bronchiectasis were recognized in all patients and cavities or infiltration shadows were recognized in half of them on chest computed tomography. A definite diagnosis was obtained by bronchoalveolar lavage fluid in four patients and expectorated sputum in two. Combined chemotherapy was performed for two patients and that for pulmonary tuberculosis in one. Conclusions: Coincidental pulmonary infection due to Mycobactterium species occurred at a low percentage. Although most patients were elderly with underlying disease and clinical features were compatible with pulmonary Mycobacterium avium complex disease, the prognosis was comparatively good with and without treatment.
Contrast Enhancement of Posterior Mediastinal Ganglioneuromas—Correlation between the Level of Enhancement and Histopathological Features  [PDF]
Yoshiyuki Ozawa, Masaki Hara, Maho Kato, Shigeki Shimizu, Yuta Shibamoto
Open Journal of Radiology (OJRad) , 2014, DOI: 10.4236/ojrad.2014.41016

Purpose: Relationship between CT or MR images and histological findings, especially vascularity, has not been adequately evaluated. The purpose of this study was to investigate correlation between contrast enhancement on CT and MRI and histological findings in posterior mediastinal ganglioneuromas. Materials and Methods: Contrast-enhanced (CE) CT (n = 11) and CE MRI (n = 5) of 12 patients with ganglioneuroma were reviewed. The attenuation, signal intensity, and dynamic enhancement pattern of the tumors were evaluated. The vascularity was histologically evaluated by the numbers of vessels. Results: Enhancement on CE-CT was none, mild, moderate, and high enhancement in 5 (45%), 2 (18%), 3 (27%), and 1 (9%) of the 11 lesions, respectively. Dynamic MRI showed mild, moderate and high enhancement in 3 (60%), 1 (20%) and 1 (20%) cases, respectively. The level of contrast enhancement correlated well only with the number of capillary vessels (r = 0.79, P = 0.0037). Conclusion: The posterior mediastinal ganglioneuromas sometimes show insufficient enhancement particularly on CE-CT. The level of enhancement might correlate with the amount of capillary vessels.

Clinical Application of T-SPOT.TB Using Pleural Effusion as a Diagnostic Method for Tuberculosis Infection  [PDF]
Yoshihiro Kobashi, Keiji Mouri, Yasushi Obase, Shigeki Kato, Mikio Oka
Open Journal of Respiratory Diseases (OJRD) , 2014, DOI: 10.4236/ojrd.2014.42010
Introduction: The objective of this study was the comparison of the results of T-SPOT.TB using pleural effusion (PE) with those of IGRAs using peripheral blood (PB) or other diagnostic methods for the diagnosis of tuberculous (TB) pleurisy. Methods: We measured adenosine deaminase (ADA) in PE, QuantiFERON TB-Gold In-Tube (QFT), and T-SPOT.TB using PB, and T-SPOT.TB using PE. The definite group of TB pleurisy included 12 patients and other disease group 33 patients. Main find-ings: Sensitivity for QFT using PB was 83% and specificity was 85%, sensitivity for T-SPOT.TB using PB was 92% and specificity was 82%, while sensitivity for ADA in PE was 83% and specificity was 76%. When we adopted the same cut-off level of a positive response for T-SPOT.TB as PB using PE, sensitivity for T-SPOT.TB using PE was 100% and specificity was 82%, respectively. Although there were no significant differences among the four diagnostic methods, sensitivity for T-SPOT.TB using PE gave the most accurate diagnosis of TB-definite patients compared to ADA in PE or QFT using PB. Conclusions: If we performed T-SPOT.TB using a local specimen from the infection site, we could obtain a higher sensitivity than IGRAs using PB or ADA in PE and the numbers of ESAT-6 and CFP-10-positive SFCs were 3 to 5 fold higher in PEMCs than in PBMCs. T-SPOT.TB using PE may become a useful diagnostic method for TB pleurisy.
Clinical Evaluation of New Biomarkers including IFN-γ for the Diagnosis of Active Tuberculosis Disease  [PDF]
Yoshihiro Kobashi, Keiji Mouri, Shigeki Kato, Mikio Oka
Journal of Tuberculosis Research (JTR) , 2015, DOI: 10.4236/jtr.2015.34020
Abstract: Background: The aim of this study was to evaluate the clinical potential of new biomarkers such as IL-2, TNF-α, MCP-1, MIP-1β including IFN-γ for the diagnosis of active tuberculosis (TB) disease. Materials and Methods: The subjects consisted of 31 patients with active TB disease and 62 patients with non-TB disease. We measured IFN-γ using QuantiFERON-TB Gold In Tube, and IL-2, TNF-α, MCP-1, and MIP-1β using the supernatant from whole blood stimulated with MTB (Mycobacterium tuberculosis)-specific antigens. Results: In the patient group with active TB disease, while the positive response rate of IFN-γ was 74%, that of IL-2 using the supernatant was 61%, TNF-α was 71%, MCP-1 was 81% and MIP-1β was 81%. In the patient group with non-TB disease, while the positive response rate of IFN-γ was 11%, that of IL-2using the supernatant was 32%, TNF-α was 26%, MCP-1 was 23% and MIP-1β was 19%. All biomarker levels of the patients with active TB disease using the supernatant were significantly higher than those of the patients with non-TB disease. While MIP-1β was the most sensitive of all the biomarkers (sensitivity: 80.6%), IFN-γ was the best in terms of specificity (specificity: 87.0%). Conclusions: Several biomarkers, apart from IL-2, showed similar results compared to IFN-γ. The combination of IFN-γ and other new biomarkers may increase the diagnostic accuracy of active TB.
Pulmonary Mycobacterium kansasii Disease in Previously Healthy Women  [PDF]
Yoshihiro Kobashi, Masaaki Abe, Keiji Mouri, Shigeki Kato, Mikio Oka
Journal of Tuberculosis Research (JTR) , 2016, DOI: 10.4236/jtr.2016.44017
Abstract: We encountered two cases of pulmonary M. kansasii disease in two women without underlying diseases in our hospital. Case 1 was a 52-year-old woman who visited with an abnormal chest shadow. She showed nodular and linear shadows with bronchiectatic changes and small cavities in the left upper lobe and lingula, and was diagnosed with pulmonary M. kansasii disease because M. kansasii was isolated from her bronchoscopic specimens. Case 2 was a 33-year-old woman who visited with a productive cough. She showed several cavity lesions in the right lung, and was diagnosed with pulmonary M. kansasii disease from several isolated sputum samples. Combination therapy using INH, RFP, and EB was effective treatment for the two cases. Because pulmonary M. kansasii disease in previously healthy women shows various radiological patterns, it was considered important to perform acid-fast bacilli examination using clinical specimens in order to decide on the appropriate treatment methods.
Clinical Analysis of Pulmonary Nontuberculous Mycobacterial Disease Complicated by Lung Cancer during the Follow-Up Periods  [PDF]
Yoshihiro Kobashi, Makoto Kittaka, Keiji Mouri, Shigeki Kato, Mikio Oka
Open Journal of Respiratory Diseases (OJRD) , 2016, DOI: 10.4236/ojrd.2016.64009
Abstract: Introduction: The objective of this study was the estimation of the clinical characteristics of patients with pulmonary nontuberculous mycobacterial (NTM) disease complicated by lung cancer during the follow-up periods. Methods: We analyzed the clinical findings of four patients (2.0%) complicated by lung cancer during the follow-up periods of over six months at least after the definite diagnosis of pulmonary NTM disease of 202 patients with pulmonary NTM disease experienced in our hospital in the last decade. Results: There were four patients with pulmonary NTM disease complicated by lung cancer and all of them were caused by Mycobacterium avium complex (MAC). They were all elderly male patients and had underlying diseases. Three patients were diagnosed with primary lung cancer and one diagnosed with metastatic lung cancer from colon cancer within 3 years after the diagnosis of pulmonary NTM disease. The treatments for lung cancer were surgical resection for all patients with localized lesions. One patient died due to the worsening of underlying disease and the remaining three survived except for the recurrence of one patient. Conclusion: Although the complication rate of pulmonary NTM disease and lung cancer was a lower percentage (2.0%) than in previous reports, the careful follow-up for patients with pulmonary NTM disease without forgetting the possible complication of lung cancer is necessary.
Pulmonary Mycobacterium kansasii Disease with Solitary Nodule  [PDF]
Yoshihiro Kobashi, Masaaki Abe, Ryo Shirai, Shigeki Kato
Journal of Tuberculosis Research (JTR) , 2019, DOI: 10.4236/jtr.2019.71003
Abstract: We recently encountered two patients with pulmonary Mycobacterium kansasii disease showing a solitary nodule. The patients were 53 and 66 years old and both were male. One patient had underlying diseases. The diagnosis was based on the clinical symptom in one patient and an abnormal chest shadow in the other. The final diagnosis was obtained by bronchoscopy and CT-guided lung biopsy. Antituberculous drugs were administered to one patient. We emphasize the importance of the positive identification of causative microorganisms in patients who present with a solitary nodule including surgical methods to differentiate the infection from lung cancer.
Environmentally Induced Under-Development of Seeds in Garden Pea and Its Underlying Factors  [PDF]
Akira Horibata, Takuji Ito, Masayuki Kotani, Takahide Kawanishi, Hiroshi Shinto, Kazuyoshi Tsuji, Shigeki Kusu, Tsuneo Kato
Agricultural Sciences (AS) , 2016, DOI: 10.4236/as.2016.77045
Abstract: Under-development of pea (Pisum sativum L.) seeds in normally developed pods, resulting in “unfilled pods”, has been a serious problem in the greenhouse cultivation in Wakayama Prefecture, one of the major regions of pea cultivation in Japan. This phenomenon appears to be induced by low temperature and low solar irradiation during pea growing season. This study examined the relationship between this seed under-development and sucrose-to-starch metabolism in developing seeds and pods after flowering. The starch content, ADP-glucose pyrophosphorylase (AGPase) and sucrose synthase activities of a pea cultivar, Kishuusui, were monitored through seed development in shading-treatment plot and in control plot. Results showed that the present treatment induced the depression of starch accumulation and AGPase activity in developing seeds compared with control, which might cause the occurrence of under-development of seeds and unfilled pods. Surplus carbohydrates from source organs might be stored in pod walls, as expected from higher starch level and AGPase activity in treated pod walls. The necessity of thermostable AGPase variants in pea to prevent the unfilled-pod problem was discussed.
RETRACTED: Usefulness of Iron-Containing Fiducial Marker for Prostate Radiotherapy  [PDF]
Osamu Tanaka, Hisao Komeda, Takayoshi Iida, Masayoshi Tamaki, Kensaku Seike, Daiki Kato, Takamasa Yokoyama, Shigeki Hirose, Daisuke Kawaguchi, Eiichi Yama
International Journal of Medical Physics,Clinical Engineering and Radiation Oncology (IJMPCERO) , 2016, DOI: 10.4236/ijmpcero.2016.54033

Short Retraction Notice

The paper does not meet the standards of \"International Journal of Medical Physics, Clinical Engineering and Radiation Oncology\".

This article has been retracted to straighten the academic record. In making this decision the Editorial Board follows COPE's Retraction Guidelines. The aim is to promote the circulation of scientific research by offering an ideal research publication platform with due consideration of internationally accepted standards on publication ethics. The Editorial Board would like to extend its sincere apologies for any inconvenience this retraction may have caused.

The full retraction notice in PDF is preceding the original paper, which is marked \"RETRACTED\".

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