331 research outputs found
Smoke-like echo in the left atrial cavity in mitral valve disease: Its features and significance
In some patients with mitral stenosis, a smoke-like echo is observed in the left atrial cavity. The present study in 116 consecutive patients with rheumatic mitral valve disease investigated the echocardiographic features and clinical significance of this echo. The smoke-like echo is characterized by the following echocardiographic features: 1) it is composed of numerous microechoes; 2) it curls up slowly in the enlarged left atrial cavity; and 3) it vanishes as soon as it pours into the ventricular cavity. Hemostasis in the left atrial cavity was considered to be an important underlying condition for development of the echo. Hemorheologic conditions indicated that the shear rate of blood flow in the left atrial cavity was calculated to be low enough for the development of red blood cell aggregation.These conditions suggest that the source of the smokelike echo might be aggregated cells due to hemostasis in the left atrial cavity. Left atrial thrombi were detected in many patients who had this echo in the left atrial cavity. Although it has not been conclusively determined that the presence of the smoke-like echo is a necessary condition for thrombus formation, this echo appears to be closely related to thrombus formation in the left atrial cavity. It is concluded that the presence of this echo indicates severe left atrial hemostasis and is a warning for thrombus formation
Recent Fusion Research in the National Institute for Fusion Science
The National Institute for Fusion Science (NIFS), which was established in 1989, promotes academic approaches toward the exploration of fusion science for steady-state helical reactor and realizes the establishment of a comprehensive understanding of toroidal plasmas as an inter-university research organization and a key center of worldwide fusion research. The Large Helical Device (LHD) Project, the Numerical Simulation Science Project, and the Fusion Engineering Project are organized for early realization of net current free fusion reactor, and their recent activities are described in this paper. The LHD has been producing high-performance plasmas comparable to those of large tokamaks, and several new findings with regard to plasma physics have been obtained. The numerical simulation science project contributes understanding and systemization of the physical mechanisms of plasma confinement in fusion plasmas and explores complexity science of a plasma for realization of the numerical test reactor. In the fusion engineering project, the design of the helical fusion reactor has progressed based on the development of superconducting coils, the blanket, fusion materials and tritium handling
Monte Carlo study of cuprate superconductors in a four-band - model: Role of orbital degrees of freedom
Understanding the complex phase diagram of cuprate superconductors is a
long-standing challenging problem. Recent studies have shown that orbital
degrees of freedom, both Cu orbitals and O orbitals, are a key
ingredient for a unified understanding of cuprate superconductors, including
the material dependence. Here we investigate a four-band - model derived
from the first-principles calculations with the variational Monte Carlo method,
which allows us to elucidate competing orders on an equal footing. The obtained
results can consistently explain the doping dependence of superconductivity,
antiferromagnetic and stripe phases, phase separation in the underdoped region,
and also novel magnetism in the heavily-overdoped region. Our four-band -
model with neighbouring intersite interactions is a minimal model to describe
the phase diagram comprehensively. The presence of orbitals is critical to
the charge-stripe features, which induce two types of stripe phases with
-wave and -wave bond stripe. On the other hand, the presence of
orbital is indispensable to material dependence of the
superconducting transition temperature (), and enhances local
magnetic moment as a source of novel magnetism in the heavily-overdoped region
as well. These findings beyond one-band description could provide a major step
toward a full explanation of unconventional normal state and high
in cuprate supercondutors.Comment: 15 pages, 10 figures, submitted to Phys. Rev. Research. arXiv admin
note: text overlap with arXiv:2105.1166
Treatment for Churg-Strauss Syndrome: Induction of Remission and Efficacy of Intravenous Immunoglobulin Therapy
ABSTRACTChurg-Strauss syndrome (CSS) is characterized by the presence of asthma, eosinophilia, and small-vessel vasculitis with granuloma. It is a distinct entity, as determined from all classifications of systemic vasculitis. The poor prognostic factors in CSS are renal insufficiency, cardiomyopathy, severe gastrointestinal (GI) tract, and central nervous systems (CNS) involvement. The initial management of CSS should include a high dose of a corticosteroid: prednisone at 1 mg/kg/day or its equivalent for methylprednisolone with tapering over 6 months. In patients with severe or rapidly progressing CSS, the administration of methylprednisolone pulse at 1 g/body/day for 3 days is recommended. When corticosteroid therapy does not induce remission, or when patients have poor prognostic factors, immunosuppressive cytotoxic therapy is indicated. However, some patients with severe CSS often show resistance to conventional treatment. We think that IVIG therapy is a hopeful candidate for second-line treatment for CSS patients, particularly in the case of neuropathy and/or cardiomyopathy, which are resistant to conventional therapy. However, there is not much evidence supporting the effectiveness of IVIG in CSS, and the mechanisms underlying the action of IVIG remain unclear. Now we are performing clinical trials of IVIG therapy for CSS patients who are resistant to conventional treatment, through a nationwide double-blinded placebo-controlled study in Japan
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