A NuSTAR view of powerful gamma-ray loud blazars

We observed with the NuSTAR satellite 3 blazars at z>2, detected in gamma-rays by Fermi/LAT and in the soft X-rays, but not yet observed above 10 keV. The flux and slope of their X-ray continuum, together with Fermi/LAT data allows us to estimate their total electromagnetic output and peak frequency. For some of them we can study the source in different states, and investigate the main cause of the observed different spectral energy distribution. We then collected all blazars at redshift greater than 2 observed by NuSTAR, and confirm that these hard and luminous X-ray blazars are among the most powerful persistent sources in the Universe. We confirm the relation between the jet power and the disk luminosity, extending it at the high energy end.Comment: 10 pages, 13 figures, accepted for publication in A&

Probing the Residual Structure in Avian Prion Hexarepeats by CD, NMR and MD Techniques

Many proteins perform essential biological functions by means of regions that lacking specific organized structure exist as an ensemble of interconverting transient conformers. The characterization of such regions, including the description of their structural propensities, number of conformations and relative populations can provide useful insights. Prion diseases result from the conversion of a normal glycoprotein into a misfolded pathogenic isoform. The structures of mammal and chicken prion proteins show a similar fold with a globular domain and a flexible N-terminal portion that contains different repeated regions: octarepeats (PHGGGWGQ) in mammals and hexarepeats (PHNPGY) in chickens. The higher number of prolines in the hexarepeat region suggests that this region may retain a significant amount of residual secondary structure. Here, we report the CD, NMR and MD characterization of a peptide (2-HexaPY) composed of two hexarepeats. We combine experimental NMR data and MD to investigate at atomic level its ensemble-averaged structural properties, demonstrating how each residue of both repeats has a different quantified PPII propensity that shows a periodicity along the sequence. This feature explains the absence of cooperativity to stabilize a PPII conformation. Nonetheless, such residual structure can play a role in nucleating local structural transitions as well as modulating intra-molecular or inter-molecular interactions

Acellular dermal matrix used in diabetic foot ulcers: Clinical outcomes supported by biochemical and histological analyses

Diabetic foot ulcer (DFU) is a diabetes complication which greatly impacts the patient’s quality of life, often leading to amputation of the affected limb unless there is a timely and adequate management of the patient. DFUs have a high economic impact for the national health system. Data have indeed shown that DFUs are a major cause of hospitalization for patients with diabetes. Based on that, DFUs represent a very important challenge for the national health system. Especially in developed countries diabetic patients are increasing at a very high rate and as expected, also the incidence of DFUs is increasing due to longevity of diabetic patients in the western population. Herein, the surgical approach focused on the targeted use of the acellular dermal matrix has been integrated with biochemical and morphological/histological analyses to obtain evidence-based information on the mechanisms underlying tissue regeneration. In this research report, the clinical results indicated decreased postoperative wound infection levels and a short healing time, with a sound regeneration of tissues. Here we demonstrate that the key biomarkers of wound healing process are activated at gene expression level and also synthesis of collagen I, collagen III and elastin is prompted and modulated within the 28-day period of observation. These analyses were run on five patients treated with Integra® sheet and five treated with the injectable matrix Integra® Flowable, for cavitary lesions. In fact, clinical evaluation of improved healing was, for the first time, supported by biochemical and histological analyses. For these reasons, the present work opens a new scenario in DFUs treatment and follow-up, laying the foundation for a tailored protocol towards complete healing in severe pathological conditions

Point-of-care pancreatic stone protein measurement in critically ill COVID-19 patients

Introduction Pancreatic stone protein (PSP) is a novel biomarker that is reported to be increased in pneumonia and acute conditions. The primary aim of this study was to prospectively study plasma levels of PSP in a COVID-19 intensive care unit (ICU) population to determine how well PSP performed as a marker of mortality in comparison to other plasma biomarkers, such as C reactive protein (CRP) and procalcitonin (PCT).Methods We collected clinical data and blood samples from COVID-19 ICU patients at the time of admission (T0), 72 h later ( T1), five days later (T2), and finally, seven days later. The PSP plasma level was measured with a point-of-care system; PCT and CRP levels were measured simultaneously with laboratory tests. The inclusion criteria were being a critical COVID-19 ICU patient requiring ventilatory mechanical assistance.Results We enrolled 21 patients and evaluated 80 blood samples; we found an increase in PSP plasma levels according to mixed model analysis over time (p < 0.001), with higher levels found in the nonsurvivor population (p < 0.001). Plasma PSP levels achieved a statistically significant result in terms of the AUROC, with a value higher than 0.7 at T0, T1, T2, and T3. The overall AUROC of PSP was 0.8271 (CI (0.73-0.93), p < 0.001). These results were not observed for CRP and PCT.Conclusion These first results suggest the potential advantages of monitoring PSP plasma levels through point-of-care technology, which could be useful in the absence of a specific COVID-19 biomarker. Additional data are needed to confirm these results

GASP XXXIV: Unfolding the thermal side of ram pressure stripping in the jellyfish galaxy JO201

X-ray studies of jellyfish galaxies play a crucial role in understanding the interactions between the interstellar medium (ISM) and the intracluster medium (ICM). In this paper, we focused on the jellyfish galaxy JO201. By combining archival Chandra observations, MUSE H$\alpha$ cubes, and maps of the emission fraction of the diffuse ionised gas, we investigated both its high energy spectral properties and the spatial correlation between its X-ray and optical emissions. The X-ray emission of JO201 is provided by both the Compton thick AGN (L$_{\text{X}}^{0.5-10 \text{keV}}$=2.7$\cdot$10$^{41}$ erg s$^{-1}$, not corrected for intrinsic absorption) and an extended component (L$_{\text{X}}^{0.5-10 \, \text{keV}}\approx$1.9-4.5$\cdot$10$^{41}$ erg s$^{-1}$) produced by a warm plasma (kT$\approx$1 keV), whose luminosity is higher than expected from the observed star formation (L$_{\text{X}}\sim$3.8$\cdot10^{40}$ erg s$^{-1}$). The spectral analysis showed that the X-ray emission is consistent with the thermal cooling of hot plasma. These properties are similar to the ones found in other jellyfish galaxies showing extended X-ray emission. A point-to-point analysis revealed that this X-ray emission closely follows the ISM distribution, whereas CLOUDY simulations proved that the ionisation triggered by this warm plasma would be able to reproduce the [OI]/H$\alpha$ excess observed in JO201. We conclude that the galactic X-ray emitting plasma is originated on the surface of the ISM as a result of the ICM-ISM interplay. This process would entail the cooling and accretion of the ICM onto the galaxy, which could additionally fuel the star formation, and the emergence of [OI]/H$\alpha$ excess in the optical spectrum.Comment: 21 pages, 6 figures, 5 tables. Manuscript in press in Ap

CHEX-MATE: Morphological analysis of the sample

A classification of the galaxy clustera's dynamical state is crucial when dealing with large samples. The identification of the most relaxed and most disturbed objects is necessary for both cosmological analysis, focused on spherical and virialised systems, and astrophysical studies, centred around all those micro-physical processes that take place in disturbed clusters (such as particle acceleration or turbulence). Among the most powerful tools for the identification of the dynamical state of clusters is the analysis of their intracluster medium (ICM) distribution. In this work, we performed an analysis of the X-ray morphology of the 118 (Cluster HEritage project with XMM-Newton -Mass Assembly and Thermodynamics at the Endpoint of structure formation) CHEX-MATE clusters, with the aim of providing a classification of their dynamical state. To investigate the link between the X-ray appearance and the dynamical state, we considered four morphological parameters: the surface brightness concentration, the centroid shift, and the second- and third-order power ratios. These indicators result to be strongly correlated with each other, powerful in identifying the disturbed and relaxed population, characterised by a unimodal distribution, and not strongly influenced by systematic uncertainties. In order to obtain a continuous classification of the CHEX-MATE objects, we combined these four parameters in a single quantity, M, which represents the grade of relaxation of a system. On the basis of the M value, we identified the most extreme systems of the sample, finding 15 very relaxed and 27 very disturbed galaxy clusters. From a comparison with previous analysis on X-ray selected samples, we confirmed that the Sunyaev-Zeldovich (SZ) clusters tend to be more disturbed. Finally, by applying our analysis to a simulated sample, we found a general agreement between the observed and simulated results, with the only exception being the concentration. This latter behaviour is partially related to the presence of particles with a high smoothed-particle-hydrodynamics density in the central regions of the simulated clusters due to the action of the idealised isotropic thermal active galactic nucleus (AGN) feedback

GASP XXXIV: Unfolding the thermal side of ram pressure stripping in the jellyfish galaxy JO201

X-ray studies of jellyfish galaxies play a crucial role in understanding the interactions between the interstellar medium (ISM) and the intracluster medium (ICM). In this paper, we focused on the jellyfish galaxy JO201. By combining archival Chandra observations, Multi Unit Spectroscopic Explorer Hα cubes, and maps of the emission fraction of the diffuse ionized gas, we investigated both its high-energy spectral properties and the spatial correlation between its X-ray and optical emissions. The X-ray emission of JO201 is provided by both the Compton-thick active galactic nucleus (L0.5X-10keV = 2.7 · 1041 erg s−1, not corrected for intrinsic absorption) and an extended component (L0.5X–10 keV » 1.9–4.5 · 1041 erg s−1) produced by a warm plasma (kT»1 keV), whose luminosity is higher than expected from the observed star formation (LX ~ 3.8 · 1040erg s−1). The spectral analysis showed that the X-ray emission is consistent with the thermal cooling of hot plasma. These properties are similar to the ones found in other jellyfish galaxies showing extended X-ray emission. A point-to-point analysis revealed that this X-ray emission closely follows the ISM distribution, whereas CLOUDY simulations proved that the ionization triggered by this warm plasma would be able to reproduce the [O I]/Hα excess observed in JO201. We conclude that the galactic X-ray emitting plasma originates on the surface of the ISM as a result of the ICM–ISM interplay. This process would entail the cooling and accretion of the ICM onto the galaxy, which could additionally fuel the star formation, and the emergence of [O I]/Hα excess in the optical spectrum

CHEX-MATE: Constraining the origin of the scatter in galaxy cluster radial X-ray surface brightness profiles

We investigate the statistical properties and the origin of the scatter within the spatially resolved surface brightness profiles of the CHEXâ MATE sample, formed by 118 galaxy clusters selected via the SZ effect. These objects have been drawn from the Planck SZ catalogue and cover a wide range of masses, M500â =â [2â â â 15]à - 1014â Mâ , and redshift, zâ =â [0.05,â 0.6]. We derived the surface brightness and emission measure profiles and determined the statistical properties of the full sample and sub-samples according to their morphology, mass, and redshift. We found that there is a critical scale, Râ â ¼â 0.4R500, within which morphologically relaxed and disturbed object profiles diverge. The median of each sub-sample differs by a factor of â ¼10 at 0.05R500. There are no significant differences between mass- and redshift-selected sub-samples once proper scaling is applied. We compare CHEXâ MATE with a sample of 115 clusters drawn from the THE THREE HUNDRED suite of cosmological simulations. We found that simulated emission measure profiles are systematically steeper than those of observations. For the first time, the simulations were used to break down the components causing the scatter between the profiles. We investigated the behaviour of the scatter due to object-by-object variation. We found that the high scatter, approximately 110%, at R

CHEX-MATE: Characterization of the intra-cluster medium temperature distribution

Context. Galaxy clusters grow through the accretion of mass over cosmic time. Their observed properties are then shaped by how baryons distribute and energy is diffused. Thus, a better understanding of spatially resolved, projected thermodynamic properties of the intra-cluster medium (ICM) may provide a more consistent picture of how mass and energy act locally in shaping the X-ray observed quantities of these massive virialized or still collapsing structures. Aims. We study the perturbations in the temperature (and density) distribution to evaluate and characterize the level of inhomogeneities and the related dynamical state of the ICM. Methods. We obtain and analyze the temperature and density distribution for 28 clusters (2.4 × 1014Mo ̇ < M500 < 1.2 × 1015Mo ̇; 0.07 < z < 0.45) selected from the CHEX-MATE sample. We use these spatially resolved two-dimensional distributions to measure the global and radial scatter and identify the regions that deviate the most from the average distribution. During this process, we introduce three dynamical state estimators and produce "clean"temperature profiles after removing the most deviant regions. Results. We find that the temperature distribution of most of the clusters is skewed towards high temperatures and is well described by a log-normal function. There is no indication that the number of regions deviating more than 1σ from the azimuthal value is correlated with the dynamical state inferred from morphological estimators. The removal of these regions leads to local temperature variations up to 10- 20% and an average increase of ∼5% in the overall cluster temperatures. The measured relative intrinsic scatter within R500, σ T,int/T, has values of 0.17-0.05+0.08, and is almost independent of the cluster mass and dynamical state. Comparing the scatter of temperature and density profiles to hydrodynamic simulations, we constrain the average Mach number regime of the sample to M3D = 0.36-0.09+0.16. We infer the ratio between the energy in turbulence and the thermal energy, and translate this ratio in terms of a predicted hydrostatic mass bias b, estimating an average value of b ∼ 0.11 (covering a range between 0 and 0.37) within R500. Conclusions. This study provides detailed temperature fluctuation measurements for 28 CHEX-MATE clusters which can be used to study turbulence, derive the mass bias, and make predictions on the scaling relation properties

A retrofitting technique using steel grids for existing masonry panels: a numerical and analytical study

The current research focuses on a numerical and analytical study aimed at investigating the efficiency of a steel-based reinforcement system suitable for existing masonry walls. The application of such a retrofitting technique, which consists of glued thin steel grids applied on both faces of a masonry panel, is reversible, cheap and easy to be executed and appears to be suitable especially for buildings with concrete slab or inter-stories beams to which the steel elements could be anchored. The study is based on a reference experimental test carried out at the “Politehnica” University of Timisoara (Romania), within the European FP6 project PROHITECH. The reference test provided the application of a constant ver-tical compression and cyclic horizontal displacements to an unreinforced brick-cement mortar wall in full-scale (1500 × 1500 × 250mm), to which was conferred a double-fixed constraint condition. Based on the experimental evidences, a reference numerical model has been implemented in ABAQUS, by adopting a plastic-damage material and a macro-element approach for the masonry modelling. Hence, in order to determine a design crite-rion of the studied system, a comparison with the analytical formulations available in the current Italian and European codes for the unreinforced configuration is presented in this study. Then, a wide parametric study on the investigated retrofitting technique has been carried out by varying thickness and spacing of steel grid elements, as well as the geo-metrical ratio of the panel (height/length). On the basis of the numerical results, a capac-ity formulation has been proposed, which takes into account the steel distribution in the masonry panel. The obtained outcomes revealed that the strength increase achievable by adopting the studied reinforcement system could be compared to the efficiency of a rein-forced masonry wall of new construction and it is strongly influenced by the geometrical ratio of the wall, as well as the steel distribution