496 research outputs found
First Detection of X-Ray Line Emission from Type IIn Supernova 1978K with XMM-Newton's RGS
We report on robust measurements of elemental abundances of the Type IIn
supernova SN 1978K, based on the high-resolution X-ray spectrum obtained with
the Reflection Grating Spectrometer (RGS) onboard XMM-Newton. The RGS clearly
resolves a number of emission lines, including N Ly, O Ly, O
Ly, Fe XVII, Fe XVIII, Ne He and Ne Ly for the first
time from SN 1978K. The X-ray spectrum can be represented by an absorbed,
two-temperature thermal emission model, with temperatures of keV
and keV. The elemental abundances are obtained to be N
, O , Ne , Fe
times the solar values. The low metal abundances except
for N show that the X-ray emitting plasma originates from the circumstellar
medium blown by the progenitor star. The abundances of N and O are far from
CNO-equilibrium abundances expected for the surface composition of a luminous
blue variable, and resemble the H-rich envelope of less-massive stars with
masses of 10-25 M. Together with other peculiar properties of SN 1978K,
i.e., a low expansion velocity of 500-1000 km s and SN IIn-like optical
spectra, we propose that SN 1978K is a result of either an electron-capture SN
from a super asymptotic giant branch star, or a weak Fe core-collapse explosion
of a relatively low-mass (10 M) or high-mass (20-25
M) red supergiant star. However, these scenarios can not naturally
explain the high mass-loss rate of the order of over 1000 yr before the explosion, which is
inferred by this work as well as many other earlier studies. Further
theoretical studies are required to explain the high mass-loss rates at the
final evolutionary stages of massive stars.Comment: 10 pages, 6 figures, accepted for publication in PAS
Performance of the Charge Injection Capability of Suzaku XIS
A charge injection technique is applied to the X-ray CCD camera, XIS (X-ray
Imaging Spectrometer) onboard Suzaku. The charge transfer inefficiency (CTI) in
each CCD column (vertical transfer channel) is measured by the injection of
charge packets into a transfer channel and subsequent readout. This paper
reports the performances of the charge injection capability based on the ground
experiments using a radiation damaged device, and in-orbit measurements of the
XIS. The ground experiments show that charges are stably injected with the
dispersion of 91eV in FWHM in a specific column for the charges equivalent to
the X-ray energy of 5.1keV. This dispersion width is significantly smaller than
that of the X-ray events of 113eV (FWHM) at approximately the same energy. The
amount of charge loss during transfer in a specific column, which is measured
with the charge injection capability, is consistent with that measured with the
calibration source. These results indicate that the charge injection technique
can accurately measure column-dependent charge losses rather than the
calibration sources. The column-to-column CTI correction to the calibration
source spectra significantly reduces the line widths compared to those with a
column-averaged CTI correction (from 193eV to 173eV in FWHM on an average at
the time of one year after the launch). In addition, this method significantly
reduces the low energy tail in the line profile of the calibration source
spectrum.Comment: Paper contains 18 figures and 15 tables. Accepted for publication in
PAS
Suzaku Observations of the North Polar Spur: Evidence for Nitrogen Enhancement
We present observations of the North Polar Spur (NPS) using the X-ray Imaging
Spectrometer (XIS) aboard the Suzaku X-ray satellite. The NPS is a large region
of enhanced soft X-ray and radio emission projected above the plane of the
Galaxy, likely produced by a series of supernovae and stellar winds from the
nearby Sco-Cen OB association. The exceptional sensitivity and spectral
resolution of the XIS below 1 keV allow unprecedented probing of low-energy
spectral lines, including CVI (0.37 keV) and NVII (0.50 keV), and we have
detected highly-ionized nitrogen toward the NPS for the first time. For this
single pointing toward the brightest 3/4 keV emission (l = 26.8 deg, b = +22.0
deg), the best-fit NPS emission model implies a hot (kT ~ 0.3 keV), collisional
ionization equilibrium (CIE) plasma with depleted C, O, Ne, Mg, and Fe
abundances of less than 0.5 solar, but an enhanced N abundance, with N/O = 4.0
+0.4,-0.5 times solar. The temperature and total thermal energy of the gas
suggest heating by one or more supernovae, while the enhanced nitrogen
abundance is best explained by enrichment from stellar material that has been
processed by the CNO cycle. Due to the time required to develop AGB stars, we
conclude that this N/O enhancement cannot be caused by the Sco-Cen OB
association, but may result from a previous enrichment episode in the solar
neighborhood.Comment: 13 pages, 10 figures, accepted for publication in PASJ (2nd Suzaku
Special Issue
Impact of long-acting calcium channel blockers on the prognosis of patients with coronary artery disease with and without chronic kidney disease: A comparison of three drugs
金沢大学医薬保健研究域医学系Calcium channel blockers (CCBs) can prevent cardiovascular events in patients with coronary artery disease (CAD). This study looked retrospectively at the prognosis of CAD in hypertensive patients with CAD who had undergone a coronary angiograph, had been given a CCB (benidipine [n = 66], amlodipine [n = 45], or long-acting nifedipine [n = 31]) on hospital discharge and were then followed up for a mean ± SD of 5.2 ± 2.9 years. Systolic/diastolic blood pressure for all 142 patients decreased significantly from a mean ± SD of 137 ± 20/74 ± 15 mmHg to 129 ± 20/71 ± 12 mmHg. Major adverse cardiovascular events (MACE) occurred in 15 patients. Chronic kidney disease (CKD) was a significant risk factor for MACE (hazard ratio 2.35, 95%confidence intervals 1.45, 3.80). Benidipine was superior to nifedipine in preventing MACE in patients both with and without CKD. In conclusion, benidipine and amlodipine reduced the frequency of MACE in hypertensive patients with CAD, particularly in those with complicating CKD. © 2010 Field House Publishing LLP
Monte-Carlo Simulator and Ancillary Response Generator of Suzaku XRT/XIS System for Spatially Extended Source Analysis
We have developed a framework for the Monte-Carlo simulation of the X-Ray
Telescopes (XRT) and the X-ray Imaging Spectrometers (XIS) onboard Suzaku,
mainly for the scientific analysis of spatially and spectroscopically complex
celestial sources. A photon-by-photon instrumental simulator is built on the
ANL platform, which has been successfully used in ASCA data analysis. The
simulator has a modular structure, in which the XRT simulation is based on a
ray-tracing library, while the XIS simulation utilizes a spectral
"Redistribution Matrix File" (RMF), generated separately by other tools.
Instrumental characteristics and calibration results, e.g., XRT geometry,
reflectivity, mutual alignments, thermal shield transmission, build-up of the
contamination on the XIS optical blocking filters (OBF), are incorporated as
completely as possible. Most of this information is available in the form of
the FITS (Flexible Image Transport System) files in the standard calibration
database (CALDB). This simulator can also be utilized to generate an "Ancillary
Response File" (ARF), which describes the XRT response and the amount of OBF
contamination. The ARF is dependent on the spatial distribution of the
celestial target and the photon accumulation region on the detector, as well as
observing conditions such as the observation date and satellite attitude. We
describe principles of the simulator and the ARF generator, and demonstrate
their performance in comparison with in-flight data.Comment: 19 pages with 8 figures, accepted for publication in PASJ Vol 58,
Suzaku special issu
Inflammatory pseudotumors of the kidney and the lung presenting as immunoglobulin G4-related disease: a case report
<p>Abstract</p> <p>Introduction</p> <p>It has been reported that immunoglobulin G4-related systemic disease can spread to nearly every organ, and often presents as an inflammatory mass or masses at those sites. In the kidney, this disease is often diagnosed after a radical or partial nephrectomy following the discovery of an inflammatory mass which is often suspected to be a malignant tumor. Here, we present a rare case of inflammatory pseudotumors of the kidney and the lung presenting as immunoglobulin G4-related disease, which were diagnosed by computed tomography-guided biopsies.</p> <p>Case presentation</p> <p>A 54-year-old Japanese man was referred to our hospital with suspected bilateral renal cancer, multiple lung metastases and autoimmune pancreatitis. His serum immunoglobulin G4 level was high. We used computed tomography-guided biopsies and histopathological examinations of the biopsied specimens to diagnose the tumors as immunoglobulin G4-related bilateral renal and lung inflammatory pseudotumors. Our patient was treated with oral prednisolone, and after one month of treatment, contrast-enhanced computed tomography demonstrated a general improvement, as noted by a reduction in size of the masses.</p> <p>Conclusion</p> <p>Renal masses that are formed due to immunoglobulin G4-related disease require comprehensive diagnosis to prevent unnecessary surgical resections from being performed. Further consideration should be paid to immunoglobulin G4-related diseases in the future.</p
A rare case of metastatic renal carcinoid
<p>Abstract</p> <p>Background</p> <p>Carcinoid is an endocrine cell tumor with low-grade atypia, which is generally a low-grade malignant cancer with a good prognosis. Metastatic renal carcinoid is even rarer than primary carcinoids.</p> <p>Case presentation</p> <p>We present our experience of a patient with metastatic renal carcinoid from the gastrointestinal tract.</p> <p>Conclusions</p> <p>The carcinoid tumor of the kidney in our patient, who had a history of liver metastasis from rectal carcinoid, was considered metastatic based on the pathological findings.</p
A Systematic Review of Mosquito Coils and Passive Emanators: Defining Recommendations for Spatial Repellency Testing Methodologies.
Mosquito coils, vaporizer mats and emanators confer protection against mosquito bites through the spatial action of emanated vapor or airborne pyrethroid particles. These products dominate the pest control market; therefore, it is vital to characterize mosquito responses elicited by the chemical actives and their potential for disease prevention. The aim of this review was to determine effects of mosquito coils and emanators on mosquito responses that reduce human-vector contact and to propose scientific consensus on terminologies and methodologies used for evaluation of product formats that could contain spatial chemical actives, including indoor residual spraying (IRS), long lasting insecticide treated nets (LLINs) and insecticide treated materials (ITMs). PubMed, (National Centre for Biotechnology Information (NCBI), U.S. National Library of Medicine, NIH), MEDLINE, LILAC, Cochrane library, IBECS and Armed Forces Pest Management Board Literature Retrieval System search engines were used to identify studies of pyrethroid based coils and emanators with key-words "Mosquito coils" "Mosquito emanators" and "Spatial repellents". It was concluded that there is need to improve statistical reporting of studies, and reach consensus in the methodologies and terminologies used through standardized testing guidelines. Despite differing evaluation methodologies, data showed that coils and emanators induce mortality, deterrence, repellency as well as reduce the ability of mosquitoes to feed on humans. Available data on efficacy outdoors, dose-response relationships and effective distance of coils and emanators is inadequate for developing a target product profile (TPP), which will be required for such chemicals before optimized implementation can occur for maximum benefits in disease control
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