新規電子ドープ型銅酸化物高温超伝導体の光電子分光による研究

学位の種別: 課程博士審査委員会委員 : （主査）東京大学教授 小形 正男, 東京大学教授 長谷川 修司, 東京大学准教授 松田 巌, 東京大学准教授 岡本 徹, 東京大学教授 髙木 英典University of Tokyo(東京大学

新規電子ドープ型銅酸化物高温超伝導体の光電子分光による研究

学位の種別: 課程博士審査委員会委員 : （主査）東京大学教授 小形 正男, 東京大学教授 長谷川 修司, 東京大学准教授 松田 巌, 東京大学准教授 岡本 徹, 東京大学教授 髙木 英典University of Tokyo(東京大学

Disease-Free Interval Length Correlates to Prognosis of Patients Who Underwent Metastasectomy for Esophageal Lung Metastases

BackgroundPulmonary metastasectomy is a standard method for treatment of selected pulmonary metastases cases. Nevertheless, because prognosis for patients with lung metastases from esophageal cancer who have undergone pulmonary metastasectomy is poor, candidates for this method of treatment are rare. Therefore, the efficacy of surgical treatment for pulmonary metastatic lesions from esophageal cancer has not been thoroughly examined.MethodsBetween March 1984 and May 2006, 57 patients underwent resection of pulmonary metastases from primary esophageal cancer. These cases were registered in the database developed by the Metastatic Lung Tumor Study Group of Japan and were retrospectively reviewed from the registry. After excluding eight cases because of missing information, we reviewed the remaining 49 cases and examined the prognostic factors for pulmonary metastasectomy for metastases from esophageal cancer.ResultsThere were no perioperative deaths. After pulmonary metastasectomy, disease recurred in 16 (33%) of the 49 patients. The overall 5-year survival was 29.6%. Median survival time was 18 months. The survival of patients with a disease-free interval (DFI) less than 12 months was significantly lower than patients with a DFI greater than 12 months. Through multivariate analysis, we identified DFI as a clinical factor significantly related to overall survival (p = 0.04).ConclusionsWe identified that patients with a DFI less than 12 months who underwent pulmonary metastasectomy for metastases from esophageal cancer had a worse prognosis. Pulmonary metastasectomy for esophageal cancer should be considered for selected patients with a DFI ≥12 months

A novel one-dimensional electronic state at IrTe2 Surface

Highly one-dimensional (1D) Fermi sheets are realized at the surface of a layered Ir telluride IrTe2 which exhibits a stripe-type charge and orbital order below ∼280 K. The 1D Fermi sheets appear in the low temperature range where the stripe order is well established. The 1D Fermi sheets are truncated by the bulk Fermi surfaces, and the spectral weight suppression at the Fermi level deviates from the typical Tomonaga–Luttinger behavior. The 1D band runs along the stripe and is accompanied by several branches which can be derived from the quantization in the perpendicular direction

Revealing the Orbital Composition of Heavy Fermion Quasiparticles in CeRu2Si2

We present a resonant angle-resolved photoemission spectroscopy (ARPES) study of the electronic band structure and heavy fermion quasiparticles in CeRu2Si2. Using light polarization analysis, considerations of the crystal field environment and hybridization between conduction and f electronic states, we identify the d-electronic orbital character of conduction bands crossing the Fermi level. Resonant ARPES spectra suggest that the localized Ce f states hybridize with eg and t2g states around the zone center. In this fashion, we reveal the orbital structure of the heavy fermion quasiparticles in CeRu2Si2 and discuss its implications for metamagnetism and superconductivity in the related compound CeCu2Si2