144 research outputs found
Probing mass-radius relation of protoneutron stars from gravitational-wave asteroseismology
The gravitational-wave (GW) asteroseismology is a powerful technique for
extracting interior information of compact objects. In this work, we focus on
spacetime modes, the so-called -modes, of GWs emitted from a proto-neutron
star (PNS) in the postbounce phase of core-collapse supernovae. Using results
from recent three-dimensional supernova models, we study how to infer the
properties of the PNS based on a quasi-normal mode analysis in the context of
the GW asteroseismology. We find that the -mode frequency multiplied by
the PNS radius is expressed as a linear function with respect to the ratio of
the PNS mass to the PNS radius. This relation is insensitive to the nuclear
equation of state (EOS) employed in this work. Combining with another universal
relation of the -mode oscillations, we point out that the time dependent
mass-radius relation of the PNS can be obtained by observing both the - and
-mode GWs simultaneously. Our results suggest that the simultaneous
detection of the two modes could provide a new probe into finite-temperature
nuclear EOS that predominantly determines the PNS evolution.Comment: accepted for publication in PR
A Note on Stable States of Dipolar Systems at Low Temperatures
In the past several years, many important innovations in nanotechnology were
made. Today it becomes possible to make nanosize magnetic particles, and
development of high storage-density magnetic device is desired. In such a
magnetic particle system, dipole interaction plays the main role. In this note,
we consider stable states of dipolar systems at low temperature: Some systems
show ``antiferromagnetic structure'', and others show magnetic domain
structure, depending on lattice shapes.Comment: 5 pages including 5 eps figures, to appear in "Computer Simulation
Studies in Condensed Matter Physics XVIII", Eds. D. P. Landau, S. P. Lewis,
and H.-B. Sch\"{u}ttler (Springer Verlag, Heidelberg, Berlin
Laparoscopic and Endoscopic Cooperative Surgery for Gastric Submucosal Tumor Near Esophagogastric Junction With Sliding Hiatal Hernia
The usefulness of laparoscopic and endoscopic cooperative surgery (LECS) for gastric submucosal tumors in the cardiac region has been reported in recent years. However, LECS for submucosal tumors at the esophagogastric junction with hiatal sliding esophageal hernia has not been reported, and its validity as a treatment method is unknown. The patient was a 51-year-old man with a growing submucosal tumor in the cardiac region. Surgical resection was indicated because a definitive diagnosis of the tumor was not determined. The lesion was a luminal protrusion tumor, located on the posterior wall of the stomach 20 mm from the esophagogastric junction, and had a maximum diameter of 16.3 mm on endoscopic ultrasound examination. Because of the hiatal hernia, the lesion could not be detected from the gastric side by endoscopy. Local resection was considered to be feasible because the resection line did not extend into the esophageal mucosa and the resection site could be less than half the circumference of the lumen. The submucosal tumor was resected completely and safely by LECS. The tumor was diagnosed as a gastric smooth muscle tumor finally. Nine months after surgery, a follow-up endoscopy showed reflux esophagitis. LECS was a useful technique for submucosal tumors of the cardiac region with hiatal hernia, but fundoplication might be considered for preventing backflow of gastric acid
Higher-order structure and Statistical Properties of Dipolar Nano-Particles
この論文は国立情報学研究所の電子図書館事業により電子化されました。研究会報告ダイポール相互作用は,異方性の持つr^の長距離相互作用であるため自己組織化により特殊な相構造をとる.今回,前回発表したOCTAシステムを用いた計算により確認された多様な多階層相構造と熱力学的な性質との比較を行った.計算に用いた系は,ダイポール相互作用とVan der Waals球を含む粒子系であるが,比熱にダブルピークを持つ.Van der Waals球に引力項がある場合,このピークは比較的高温で出現するが,斥力項のみの場合ではより低温に出現し生成構造も異なる
Finite dipolar hexagonal columns on piled layers of triangular lattice
We have investigated, by the Monte Carlo simulation, spin systems which
represent moments of arrayed magnetic nanoparticles interacting with each other
only by the dipole-dipole interaction. In the present paper we aim the
understanding of finite size effects on the magnetic nanoparticles arrayed in
hexagonal columns cut out from the close-packing structures or from those with
uniaxial compression. In columns with the genuine close-packing structures, we
observe a single vortex state which is also observed previously in finite
2-dimensional systems. On the other hand in the system with the inter-layer
distance set times of the close-packing one, we found ground
states which depend on the number of layers. The dependence is induced by a
finite size effect and is related to a orientation transition in the
corresponding bulk system.Comment: 3 pages, 2 figures. Proceedings of the International Conference on
Magnetism 2006 (ICM2006) conference. To appear in a special volume of Journal
of Magnetism and Magnetic Material
Differential Expression of Survivin in Mammary Gland Diseases
Objective: Unlike other inhibitors of apoptosis proteins (IAP), survivin is expressed during fetal development, cannot be detected in normal adult tissues, and is re-expressed in most of the common human cancers. However, the clinicopathological significance of the expression of survivin in human breast carcinoma has not been fully elucidated. Therefore, we examined the accumulation of survivin in pathological specimens of mammary gland diseases to identify new protein markers that may lead to improvements in patient management.Methods: We investigated the expression of survivin using immunohistochemistry in 180 cases of breast disease accessioned in the Department of Pathology, International University of Health and Welfare Hospital and Nissan Tamagawa Hospital between 2003 and 2013.Results: Ninety-eight out of 141 malignant tumor cases (69.5%) stained positive for survivin, with no significant staining being detected in the remaining cases. Staining for survivin was completely absent in the epithelial cells of 34 of 39 cases of benign disease. No correlation was observed between the expression of survivin and major prognostic factors in breast carcinomas including patient age, tumor size, histological grade, axillary lymph node metastasis, local recurrence, and visceral metastasis status. However, a significant difference was observed in the expression of survivin between malignant and benign tumors and other benign diseases.Conclusion: The results of the present study suggest that the expression of survivin is strongly selective for cancer cells and may be useful for identifying and quantifying human breast cancer
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