1,134 research outputs found
X-ray polarimetry and spectroscopy of the neutron star low-mass X-ray binary GX 9+9:An in-depth study with IXPE and <i>NuSTAR</i>
We report on a comprehensive analysis of simultaneous X-ray polarimetric and spectral data of the bright atoll source GX 9+9 with the Imaging X-ray Polarimetry Explorer (IXPE) and NuSTAR. The source is significantly polarized in the 4- 8 keV band, with a degree of 2.2% ± 0.5% (uncertainty at the 68% confidence level). The NuSTAR broad-band spectrum clearly shows an iron line, and is well described by a model including thermal disc emission, a Comptonized component, and reflection. From a spectro-polarimetric fit, we obtain an upper limit to the polarization degree of the disc of 4% (at the 99% confidence level), while the contribution of Comptonized and reflected radiation cannot be conclusively separated. However, the polarization is consistent with resulting from a combination of Comptonization in a boundary or spreading layer, plus reflection off the disc, which significantly contributes in any realistic scenario
Incontinentia Pigmenti
Incontinentia pigment! (Bloch-Sulzberger syndrome) is a rare neuroectodermal dysptasia. It is an X-linked dominant disorder caused by mutations in the IKBKG/NEMO gene on Xq28. Approximately 80% of patients have a deletion of exons 4 to 10. Incontinentia pigmenti has an estimated incidence of 0.7 cases per 100,000 births. In hemizygous males, it is usually lethal, while in females, it has a wide spectrum of clinical manifestations. Incontinentia pigmenti is a muttisystemic disease that invariably features skin changes. These changes are the main diagnostic criteria and they evolve in 4 stages, in association with other abnormalities affecting the central nervous system, eyes, teeth, mammary glands, hair, nails, skin, and other parts of the body. The aim of this brief review is to highlight the clinical features of this genodermatosis and underline the importance of case-by-case interdisciplinary management, including genetic counseling. (C) 2018 AEDV. Published by Elsevier Espana, S.L.U. All rights reserved
An XMM-Newton look at the strongly variable radio-weak BL Lac Fermi J1544-0639
Fermi J1544-0639/ASASSN-17gs/AT2017egv was identified as a gamma-ray/optical
transient on May 15, 2017. Subsequent multiwavelength observations suggest that
this source may belong to the new class of radio-weak BL Lacs. We studied the
X-ray spectral properties and short-term variability of Fermi J1544-0639 to
constrain the X-ray continuum emission mechanism of this peculiar source. We
present the analysis of an XMM-Newton observation, 56 ks in length, performed
on February 21, 2018. The source exhibits strong X-ray variability, both in
flux and spectral shape, on timescales of ~10 ks, with a harder-when-brighter
behaviour typical of BL Lacs. The X-ray spectrum is nicely described by a
variable broken power law, with a break energy of around 2.7 keV consistent
with radiative cooling due to Comptonization of broad-line region photons. We
find evidence for a `soft excess', nicely described by a blackbody with a
temperature of ~0.2 keV, consistent with being produced by bulk Comptonization
along the jet.Comment: 11 pages, 12 figures. Accepted for publication in Astronomy &
Astrophysic
Hard X-ray selected giant radio galaxies - I. The X-ray properties and radio connection
We present the first broad-band X-ray study of the nuclei of 14 hard X-ray
selected giant radio galaxies, based both on the literature and on the analysis
of archival X-ray data from NuSTAR, XMM-Newton, Swift and INTEGRAL. The X-ray
properties of the sources are consistent with an accretion-related X-ray
emission, likely originating from an X-ray corona coupled to a radiatively
efficient accretion flow. We find a correlation between the X-ray luminosity
and the radio core luminosity, consistent with that expected for AGNs powered
by efficient accretion. In most sources, the luminosity of the radio lobes and
the estimated jet power are relatively low compared with the nuclear X-ray
emission. This indicates that either the nucleus is more powerful than in the
past, consistent with a restarting of the central engine, or that the giant
lobes are dimmer due to expansion losses.Comment: 11 pages, 3 figures. Accepted for publication in MNRA
Poor clinical response in rheumatoid arthritis is the main risk factor for diabetes development in the short-term: A 1-year, single-centre, longitudinal study
Objectives Despite of the European League Against Rheumatism (EULAR) provided different sets of recommendations for the management of cardiovascular risk in inflammatory arthritis patients, it must be pointed out that cardiometabolic comorbidity, such as type 2 diabetes (T2D), remains still underdiagnosed and undertreated in patients affected by rheumatoid arthritis (RA). Methods In this work, we designed a single centre, prospective study in order to better investigate the occurrence of T2D during the course of 1 year of follow-up. Furthermore, we evaluated the role of both traditional cardiovascular and RA-specific related risk factors to predict the occurrence of new T2D. Results In this study, we evaluated 439 consecutive RA patients and we observed that 7.1% of our patients (31/439) developed T2D, after 12 month of prospective follow-up. The regression analysis showed that the presence of high blood pressure, the impaired fasting glucose (IFG) at the first observation and the poor EULAR-DAS28 response, after 12 months of follow\u2013up, were significantly associated with an increased likelihood of being classified as T2D. Similarly, we observed that 7.7% of our patients (34/439) showed IFG after 12 months of prospective follow-up. The regression analysis showed that the presence of high blood pressure and the poor EULAR-DAS28 response after 12 months of follow-up, were significantly associated with an increased likelihood of showing IFG. Conclusions Our study supports the hypothesis of a significant short-term risk of T2D in RA patients and of a close associations between uncontrolled disease activity and glucose metabolism derangement. Further multicentre, randomised-controlled studies are surely needed in order to elucidate these findings and to better ascertain the possible contribution of different therapeutic regimens to reduce this risk
Broadband X-ray spectral analysis of the Seyfert 1 galaxy GRS 1734-292
We discuss the broadband X-ray spectrum of GRS 1734-292 obtained from
non-simultaneous XMM-Newton and NuSTAR observations, performed in 2009 and
2014, respectively. GRS1734-292 is a Seyfert 1 galaxy, located near the
Galactic plane at . The NuSTAR spectrum ( keV) is dominated by
a primary power-law continuum with and a high-energy
cutoff keV, one of the lowest measured by NuSTAR in a
Seyfert galaxy. Comptonization models show a temperature of the coronal plasma
of keV and an optical depth, assuming a slab
geometry, or a similar temperature and
assuming a spherical geometry. The 2009 XMM-Newton
spectrum is well described by a flatter intrinsic continuum
() and one absorption line due to Fe\textsc{XXV}
K produced by a warm absorber. Both data sets show a modest iron
K emission line at keV and the associated Compton reflection, due
to reprocessing from neutral circumnuclear material
Epigenetic and Genetic Factors Related to Curve Progression in Adolescent Idiopathic Scoliosis: A Systematic Scoping Review of the Current Literature
Adolescent idiopathic scoliosis (AIS) is a progressive deformity of the spine. Scoliotic curves progress until skeletal maturity leading, in rare cases, to a severe deformity. While the Cobb angle is a straightforward tool in initial curve magnitude measurement, assessing the risk of curve progression at the time of diagnosis may be more challenging. Epigenetic and genetic markers are potential prognostic tools to predict curve progression. The aim of this study is to review the available literature regarding the epigenetic and genetic factors associated with the risk of AIS curve progression. This review was carried out in accordance with Preferential Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines. The search was carried out in January 2022. Only peer-reviewed articles were considered for inclusion. Forty studies were included; fifteen genes were reported as having SNPs with significant association with progressive AIS, but none showed sufficient power to sustain clinical applications. In contrast, nine studies reporting epigenetic modifications showed promising results in terms of reliable markers. Prognostic testing for AIS has the potential to significantly modify disease management. Most recent evidence suggests epigenetics as a more promising field for the identification of factors associated with AIS progression, offering a rationale for further investigation in this field
Phospholipid hydroperoxide glutathione peroxidase is the 18-kDa selenoprotein expressed in human tumor cell lines.
Human tumor cell lines cultured in 75Se-containing media demonstrate four major 75Se-labeled cellular proteins (57, 22, 18, and 12 kDa) on sodium dodecyl sulfate-polyacrylamide gel electrophoresis and autoradiography. Among these selenoproteins, an enzymatic activity is known only for the 22-kDa protein, since this protein has been identified as the monomer of glutathione peroxidase. However, all tested cell lines also contained a peroxidase activity with phospholipid hydroperoxides that is completely accounted for by the other selenoenzyme, phospholipid hydroperoxide glutathione peroxidase (PHGPX) (Ursini, F., Maiorino, M., and Gregolin, C. (1985) Biochim. Biophys. Acta 839, 62-70). Sodium dodecyl sulfate-polyacrylamide gel electrophoresis and autoradiography of 75Se-labeled proteins separated by gel permeation chromatography supported the identification of PHGPX as the monomeric protein matching the 18 kDa band. This paper is the first report on the identification of PHGPX in human cells
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