56 research outputs found

    A Discovery of a Peculiar Pulsar in the Small Magellanic Cloud

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    We report on a peculiar X-ray binary pulsar IKT1 = RXJ0047.3-7312 observed with XMM-Newton in Oct. 2000. The X-ray spectrum is described by a two-component spectrum. The hard component has a broken power-law with respective photon indices of 0.2 and 1.8, below and above the break energy at 5.8 keV. The soft component can be modeled by a blackbody of kT = 0.6 keV. The X-ray flux shows a gradual decrease and periodic variations of about 4000 s. The averaged flux in 0.7-10.0 keV is 2.9x10^-12 ergs/cm^2/s, which is ~10 times brighter than that in a ROSAT observation in Nov. 1999. In addition to the 4000-s variation, we found coherent pulsations of 263 +/- 1 s. These discoveries strengthen the Be/X-ray binary scenario proposed by the ROSAT and ASCA observations on this source, and confirm that most of the hard sources in the Small Magellanic Cloud are X-ray binary pulsars. A peculiar property of this XBP is that the coherent pulsations are found only in the soft component, and the folded light curve shows a flat top shape with a sharp dip. We discuss the nature of this XBP focusing on the peculiar soft component.Comment: 5 pages, 5figures, Accepted for publication in PAS

    A Suzaku Observation of the Low-Ionization Fe-Line Emission from RCW 86

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    The newly operational X-ray satellite Suzaku observed the southwestern quadrant of the supernova remnant (SNR) RCW 86 in February 2006 to study the nature of the 6.4 keV emission line first detected with the Advanced Satellite for Cosmology and Astronomy (ASCA). The new data confirm the existence of the line, localizing it for the first time; most of the line emission is adjacent and interior to the forward shock and not at the locus of the continuum hard emission. We also report the first detection of a 7.1 keV line that we interpret as the K-beta emission from low-ionization iron. The Fe-K line features are consistent with a non-equilibrium plasma of Fe-rich ejecta with n_{e}t <~ 10^9 cm^-3 s and kT_{e} ~ 5 keV. This combination of low n_{e}t and high kT_{e} suggests collisionless electron heating in an SNR shock. The Fe K-alpha line shows evidence for intrinsic broadening, with a width of 47 (34--59) eV (99% error region). The difference of the spatial distributions of the hard continuum above 3 keV and the Fe-K line emission support a synchrotron origin for the hard continuum.Comment: 6 pages with 6 figures. Accepted for PASJ Suzaku Special Issue (vo. 58, sp.1

    Recommendations related to the analytical equivalence assessment of gene panel testing

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    Advances in cancer genome care over the past few years have included the development of gene panel testing for various biomarkers. This article summarizes issues and provides recommendations related to analytical performance evaluations for new oncology gene panels. The scope of these recommendations includes comprehensive genomic profiling assays related to gene panel testing that uses histological or serum specimens to detect gene mutations. As a research project of the Japan Agency for Medical Research and Development Research on Regulatory Science of Pharmaceuticals and Medical Devices, we convened the working group committee that consisted of more than 30 experts from academia, industry, and government. We have discussed the points that should be considered to allow maximal simplification of assessments using clinical specimens in evaluating accuracy and limit of detection in equivalence and analytical performance for three years. We provide recommendations specific to each type of gene mutation as well as to reference standards or specimens used for evaluations. In addition, in order to facilitate the discussion on the analytical performance of gene panel tests by multidisciplinary tumor boards of hospitals, the present recommendations also describe the items that companies are expected to provide information on in their packaging inserts and reports, and the items that are expected to be discussed by multidisciplinary tumor boards. Our working group document will be important for participants in multidisciplinary tumor boards including medical oncologists and genome scientists, and developers of gene panels not only in Japan but also in other countries

    A Suzaku Observation of the Neutral Fe-line Emission from RCW 86

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    The newly operational X-ray satellite Suzaku observed the supernova remnant (SNR) RCW 86 in February 2006 to study the nature of the 6.4 keV emission line first detected with the Advanced Satellite for Cosmology and Astronomy (ASCA). The new data confirms the existence of the line, localizing it for the first time inside a low temperature emission region and not at the locus of the continuum hard X-ray emission. We also report the first detection of a 7.1 keV line that we interpret as the K(beta) emission from neutral or low-ionized iron. The Fe-K line features are consistent with a non-equilibrium plasma of Fe-rich ejecta with n(sub e) less than or approx. equal to 10(exp 9)/cu cm s and kT(sub e) > 1 keV. We found a sign that Fe K(alpha) line is intrinsically broadened 47 (35-57) eV (99% error region). Cr-K line is also marginally detected, which is supporting the ejecta origin for the Fe-K line. By showing that the hard continuum above 3 keV has different spatial distribution from the Fe-K line, we confirmed it to be synchrotron X-ray emission

    Synthesis of 2-Alkylideneisochromans by Cyclocarbonylative Sonogashira Reactions

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    In this study we used a tandem carbonylative Sonogashira reaction/cyclisation process to construct alkylidene-functionalized isochromans in high yields with complete stereoselectivity (only Z isomers were formed). The reaction was per-formed in the absence of a CuI co-catalyst with a small amount of PdCl2(PPh3)2 (0.2–0.5 mol-%), and aryl iodides bearing both electron-donating and electron-withdrawing substituents were successfully employe

    Risk factors for incisional hernia according to different wound sites after open hepatectomy using combinations of vertical and horizontal incisions: A multicenter cohort study.

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    Background:Although several risk factors for incisional hernia after hepatectomy have been reported, their relationship to different wound sites has not been investigated. Therefore, this study aimed to examine the risk factors for incisional hernia according to various wound sites after hepatectomy.Methods:Patients from the Osaka Liver Surgery Study Group who underwent open hepatectomy using combinations of vertical and horizontal incisions (J-shaped incision, reversed L-shaped incision, reversed T-shaped incision, Mercedes incision) between January 2012 and December 2015 were included. Incisional hernia was defined as a hernia occurring within 3 y after surgery. Abdominal incisional hernia was classified into midline incisional hernia and transverse incisional hernia. The risk factors for each posthepatectomy incisional hernia type were identified.Results:A total of 1057 patients met the inclusion criteria. The overall posthepatectomy incisional hernia incidence rate was 5.9% (62 patients). In the multivariate analysis, the presence of diabetes mellitus and albumin levels <3.5 g/dL were identified as independent risk factors. Moreover, incidence rates of midline and transverse incisional hernias were 2.4% (25 patients), and 2.3% (24 patients), respectively. In multivariate analysis, the independent risk factor for transverse incisional hernia was the occurrence of superficial or deep incisional surgical site infection, and interrupted suturing for midline incisional hernia.Conclusions:Risk factors for incisional hernia after hepatectomy depend on the wound site. To prevent incisional hernia, running suture use might be better for midline wound closure. The prevention of postoperative wound infection is important for transverse wounds, under the presumption of preoperative nutrition and normoglycemia

    The ASTRO-H X-ray Observatory

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    The joint JAXA/NASA ASTRO-H mission is the sixth in a series of highly successful X-ray missions initiated by the Institute of Space and Astronautical Science (ISAS). ASTRO-H will investigate the physics of the high-energy universe via a suite of four instruments, covering a very wide energy range, from 0.3 keV to 600 keV. These instruments include a high-resolution, high-throughput spectrometer sensitive over 0.3-2 keV with high spectral resolution of Delta E < 7 eV, enabled by a micro-calorimeter array located in the focal plane of thin-foil X-ray optics; hard X-ray imaging spectrometers covering 5-80 keV, located in the focal plane of multilayer-coated, focusing hard X-ray mirrors; a wide-field imaging spectrometer sensitive over 0.4-12 keV, with an X-ray CCD camera in the focal plane of a soft X-ray telescope; and a non-focusing Compton-camera type soft gamma-ray detector, sensitive in the 40-600 keV band. The simultaneous broad bandpass, coupled with high spectral resolution, will enable the pursuit of a wide variety of important science themes.Comment: 22 pages, 17 figures, Proceedings of the SPIE Astronomical Instrumentation "Space Telescopes and Instrumentation 2012: Ultraviolet to Gamma Ray

    The Quiescent Intracluster Medium in the Core of the Perseus Cluster

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    Clusters of galaxies are the most massive gravitationally-bound objects in the Universe and are still forming. They are thus important probes of cosmological parameters and a host of astrophysical processes. Knowledge of the dynamics of the pervasive hot gas, which dominates in mass over stars in a cluster, is a crucial missing ingredient. It can enable new insights into mechanical energy injection by the central supermassive black hole and the use of hydrostatic equilibrium for the determination of cluster masses. X-rays from the core of the Perseus cluster are emitted by the 50 million K diffuse hot plasma filling its gravitational potential well. The Active Galactic Nucleus of the central galaxy NGC1275 is pumping jetted energy into the surrounding intracluster medium, creating buoyant bubbles filled with relativistic plasma. These likely induce motions in the intracluster medium and heat the inner gas preventing runaway radiative cooling; a process known as Active Galactic Nucleus Feedback. Here we report on Hitomi X-ray observations of the Perseus cluster core, which reveal a remarkably quiescent atmosphere where the gas has a line-of-sight velocity dispersion of 164+/-10 km/s in a region 30-60 kpc from the central nucleus. A gradient in the line-of-sight velocity of 150+/-70 km/s is found across the 60 kpc image of the cluster core. Turbulent pressure support in the gas is 4% or less of the thermodynamic pressure, with large scale shear at most doubling that estimate. We infer that total cluster masses determined from hydrostatic equilibrium in the central regions need little correction for turbulent pressure.Comment: 31 pages, 11 Figs, published in Nature July

    New Hepatic Resection Criteria for Intermediate-Stage Hepatocellular Carcinoma Can Improve Long-Term Survival: A Retrospective, Multicenter Collaborative Study.

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    Background:Hepatic resection (HR) is not recommended for intermediate-stage hepatocellular carcinoma (HCC) by the Barcelona Clinic Liver Cancer criteria. We examined the prognostic factors of HR for intermediate-stage HCC and developed new HR criteria for intermediate-stage HCC.Methods:A total of 110 patients who underwent HR without any prior treatment for intermediate-stage HCC between January 2007 and December 2012 were enrolled at eight university hospitals. The outcomes and prognostic factors of HR were evaluated to develop new HR criteria.Results:In terms of tumor size and number, the most significant prognostic factors were within the up-to-seven criteria. Furthermore, serum albumin level ≥35 g/L and serum alpha-fetoprotein (AFP) level
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