ABSTRACT
Multimessenger astronomy received a great boost following the discovery of kilonova (KN) AT2017gfo, the optical counterpart of the gravitational wave source GW170817 associated with the ...short gamma-ray burst GRB 170817A. AT2017gfo was the first KN that could be extensively monitored in time using both photometry and spectroscopy. Previously, only few candidates have been observed against the glare of short GRB afterglows. In this work, we aim to search the fingerprints of AT2017gfo-like KN emissions in the optical/NIR light curves of 39 short GRBs with known redshift. For the first time, our results allow us to study separately the range of luminosity of the blue and red components of AT2017gfo-like kilonovae in short GRBs. In particular, the red component is similar in luminosity to AT2017gfo, while the blue KN can be more than 10 times brighter. Finally, we exclude a KN as luminous as AT2017gfo in GRBs 050509B and 061201.
We have analysed the NRAO Very Large Array Sky Survey and Sydney University Molonglo Sky Survey data at 1.4 GHz and 843 MHz for a well-defined complete sample of hard X-ray AGN observed by INTEGRAL. ...A large number (70/79) of sources are detected in the radio band, showing a wide range of radio morphologies, from unresolved or slightly resolved cores to extended emission over several hundreds of kpc scales. The radio fluxes have been correlated with the 2–10 keV and 20–100 keV emission, revealing significant correlations with slopes consistent with those expected for radiatively efficient accreting systems. The high-energy emission coming from the inner accretion regions correlates with the radio emission averaged over hundreds of kpc scales (i.e. thousands of years).
Proliferative verrucous leukoplakia (PVL) is a rare and refractory form of oral mucosal leukoplakia of unknown origin, characterized by high rates of malignant transformation. Different diagnostic ...criteria, terminologies, and therapeutic approaches have been proposed since the first report in 1985. There remains no general agreement regarding the clinical and histological diagnosis, prevention, and correct management of this disease. This retrospective study investigated 48 patients affected by PVL showing at least one malignant transformation and followed up at 2-month intervals. Twenty-five were female (52.1%) and 23 (47.9%) were male; their median age was 67 years (range 40–93 years). Follow-up ranged from 18 to 240 months. Clinical examination included the use of Lugol’s solution to prevent clinical underestimation of the margins and toluidine blue for suspicious areas. Surgical excision by scalpel was the preferred treatment for suspicious lesions, with only five carcinomas surgically removed by diode laser and two by CO2 laser. All specimens were accurately mapped after formalin fixation. Fifteen patients (31.3%; 10 female, five male) developed one oral carcinoma, while 33 (68.7%) developed two or more primary tumours (range 3–12). Only four patients (8.3%), who developed between 2 and 8 oral squamous cell carcinomas (OSCCs), died of tumour-related causes. The pre-surgical clinical workup, subsequent surgical treatment, and follow-up are key to success for patients affected by PVL with malignant transformation into stage 1 OSCC and/or verrucous carcinoma, leading to a high overall survival rate.
Context. In the last decade, astronomers have found a new type of supernova called superluminous supernovae (SLSNe) due to their high peak luminosity and long light-curves. These hydrogen-free ...explosions (SLSNe-I) can be seen to z ~ 4 and therefore, offer the possibility of probing the distant Universe. Aims. We aim to investigate the possibility of detecting SLSNe-I using ESA’s Euclid satellite, scheduled for launch in 2020. In particular, we study the Euclid Deep Survey (EDS) which will provide a unique combination of area, depth and cadence over the mission. Methods. We estimated the redshift distribution of Euclid SLSNe-I using the latest information on their rates and spectral energy distribution, as well as known Euclid instrument and survey parameters, including the cadence and depth of the EDS. To estimate the uncertainties, we calculated their distribution with two different set-ups, namely optimistic and pessimistic, adopting different star formation densities and rates. We also applied a standardization method to the peak magnitudes to create a simulated Hubble diagram to explore possible cosmological constraints. Results. We show that Euclid should detect approximately 140 high-quality SLSNe-I to z ~ 3.5 over the first five years of the mission (with an additional 70 if we lower our photometric classification criteria). This sample could revolutionize the study of SLSNe-I at z > 1 and open up their use as probes of star-formation rates, galaxy populations, the interstellar and intergalactic medium. In addition, a sample of such SLSNe-I could improve constraints on a time-dependent dark energy equation-of-state, namely w(a), when combined with local SLSNe-I and the expected SN Ia sample from the Dark Energy Survey. Conclusions. We show that Euclid will observe hundreds of SLSNe-I for free. These luminous transients will be in the Euclid data-stream and we should prepare now to identify them as they offer a new probe of the high-redshift Universe for both astrophysics and cosmology.
In this work we present spectra of all γ-ray burst (GRB) afterglows that have been promptly observed with the X-shooter spectrograph until 31/03/2017. In total, we have obtained spectroscopic ...observations of 103 individual GRBs observed within 48 hours of the GRB trigger. Redshifts have been measured for 97 per cent of these, covering a redshift range from 0.059 to 7.84. Based on a set of observational selection criteria that minimise biases with regards to intrinsic properties of the GRBs, the follow-up effort has been focused on producing a homogeneously selected sample of 93 afterglow spectra for GRBs discovered by the Swift satellite. We here provide a public release of all the reduced spectra, including continuum estimates and telluric absorption corrections. For completeness, we also provide reductions for the 18 late-time observations of the underlying host galaxies. We provide an assessment of the degree of completeness with respect to the parent GRB population, in terms of the X-ray properties of the bursts in the sample and find that the sample presented here is representative of the full Swift sample. We have constrained the fraction of dark bursts to be <28 per cent and confirm previous results that higher optical darkness is correlated with increased X-ray absorption. For the 42 bursts for which it is possible, we have provided a measurement of the neutral hydrogen column density, increasing the total number of published HI column density measurements by ∼33 per cent. This dataset provides a unique resource to study the ISM across cosmic time, from the local progenitor surroundings to the intervening Universe.
Abstract Introduction Patients undergoing bisphosphonate therapies may develop jaw lesions, mainly consisting in bone necrosis. No effective treatment has been proposed so far for such lesions, nor ...is there a uniform concept on the possible pathogenesis of this entity. Methods The study population included 31 patients with bisphosphonate-related osteonecrosis of the jaws and 10 healthy donors. All patients underwent to jaw bone biopsy and the tissue samples were divided into two parts, one of which was fixed, decalcified and routinely processed. The second part was fixed, embedded in methylmetacrylate, cut and stained with methylene blue and basic fuchsine. All samples were subjected to light and confocal microscopic examination and to histomorphometric analyses to evaluate differences in bone structure between the two samples groups. Results Three main histological patterns were identified in ONJ patients: 1 — Areas with active acute inflammation, characterized by predominance of soft tissues, inflammatory infiltrate, acellular necrotic debris, thin-walled and dilated blood vessel, intensely basophilic bone spiculae with scalloped borders showing prominent bone resorption. 2 — Areas characterized by predominance of bony structures showing wide acellular necrotic sequestra and large, scalloped Haversian canals containing inflammatory cells. 3 — Non-necrotic areas contained larger amounts of bone, showing increased trabecular thickness, inter-osteonic bone deposition and smaller and fewer Haversian canals. These differences were more evident after comparing the histomorphometrical data of samples from ONJ patients with controls. Also, lamellar bone from treated patients was composed of bigger osteones containing larger osteocytes. Two different types of newly-formed woven bone, mainly showing centrifugal spatial orientation, were easily detectable in these areas. Osteoclast-like cells detected in inflammatory areas from treated patients were small and contained few nuclei, but they were rare to absent in non-necrotic bone from the same patients. Conclusions These features point at a peculiar process of bone remodeling in patients undergoing bisphosphonate therapy, which showed scarce osteoclastic activity and subsequent deposition of newly-formed bone. The latter would be made up of thicker bone structures supplied by fewer blood vessels. Consequently, in case of increased metabolic requests, this modified bone would not be supported by adequate blood supply, thus leading to necrosis and superinfection.
GRB 090423 at a redshift of z 8.1 Racusin, J. L; Amati, L; Guidorzi, C ...
Nature (London),
10/2009, Letnik:
461, Številka:
7268
Journal Article
Recenzirano
Gamma-ray bursts (GRBs) are produced by rare types of massive stellar explosion. Their rapidly fading afterglows are often bright enough at optical wavelengths that they are detectable at ...cosmological distances. Hitherto, the highest known redshift for a GRB was z = 6.7 (ref. 1), for GRB 080913, and for a galaxy was z = 6.96 (ref. 2). Here we report observations of GRB 090423 and the near-infrared spectroscopic measurement of its redshift, z = . This burst happened when the Universe was only about 4 per cent of its current age. Its properties are similar to those of GRBs observed at low/intermediate redshifts, suggesting that the mechanisms and progenitors that gave rise to this burst about 600,000,000 years after the Big Bang are not markedly different from those producing GRBs about 10,000,000,000 years later.
The recent discovery of the electromagnetic counterpart of the gravitational wave source GW170817, has demonstrated the huge informative power of multi-messenger observations. During the next decade ...the nascent field of multi-messenger astronomy will mature significantly. Around 2030 and beyond, third generation ground-based gravitational wave detectors will be roughly ten times more sensitive than the current ones. At the same time, neutrino detectors currently upgrading to multi km3 telescopes, will include a 10 km3 facility in the Southern hemisphere. In this review, we describe the most promising sources of high frequency gravitational waves and neutrinos that will be detected in the next two decades. In this context, we show the important role of the Transient High Energy Sky and Early Universe Surveyor (THESEUS), a mission concept accepted by ESA for phase A study and proposed by a large international collaboration in response to the call for the Cosmic Vision Programme M5 missions. THESEUS aims at providing a substantial advancement in early Universe science as well as in multi–messenger and time–domain astrophysics, operating in strong synergy with future gravitational wave and neutrino detectors as well as major ground- and space-based telescopes. This review is an extension of the THESEUS white paper (Amati et al., 2017), also in light of the discovery of GW170817/GRB170817A that was announced on October 16th, 2017.
Plasmablastic lymphoma: a review Rafaniello Raviele, P; Pruneri, G; Maiorano, E
Oral diseases,
January 2009, Letnik:
15, Številka:
1
Journal Article
Recenzirano
Plasmablastic lymphoma (PBL) has been recently characterised as an aggressive subtype of non‐Hodgkin’s lymphoma, most frequently arising in the oral cavity of HIV‐infected patients. To date, ...approximately 60 cases fulfilling the clinico‐pathological characteristics of PBL have been reported. PBLs are composed of large cells with eccentrically located nuclei and deeply basophilic cytoplasm with a paranuclear hof. The tumour cells are invariably immunoreactive for the plasma cell marker CD138, and show monoclonal rearrangement of the immunoglobulin heavy chain gene (IgH) and/or clonal restriction of the Ig light chain (IgL) gene expression in most of the cases. Similar to other types of AIDS‐related lymphomas, there is evidence that Epstein–Barr virus and Kaposi‐sarcoma associated Human Herpes Virus 8 may play a relevant role in the pathogenesis of PBL. PBL patients have been treated heterogeneously, with a combination of chemotherapy, radiotherapy and/or surgery, and their prognosis is usually poor, with a death rate of approximately 60% at 1 year.
Weak lensing, which is the deflection of light by matter along the line of sight, has proven to be an efficient method for constraining models of structure formation and reveal the nature of dark ...energy. So far, most weak-lensing studies have focused on the shear field that can be measured directly from the ellipticity of background galaxies. However, within the context of forthcoming full-sky weak-lensing surveys such as Euclid , convergence maps (mass maps) offer an important advantage over shear fields in terms of cosmological exploitation. While it carry the same information, the lensing signal is more compressed in the convergence maps than in the shear field. This simplifies otherwise computationally expensive analyses, for instance, non-Gaussianity studies. However, the inversion of the non-local shear field requires accurate control of systematic effects caused by holes in the data field, field borders, shape noise, and the fact that the shear is not a direct observable (reduced shear). We present the two mass-inversion methods that are included in the official Euclid data-processing pipeline: the standard Kaiser & Squires method (KS), and a new mass-inversion method (KS+) that aims to reduce the information loss during the mass inversion. This new method is based on the KS method and includes corrections for mass-mapping systematic effects. The results of the KS+ method are compared to the original implementation of the KS method in its simplest form, using the Euclid Flagship mock galaxy catalogue. In particular, we estimate the quality of the reconstruction by comparing the two-point correlation functions and third- and fourth-order moments obtained from shear and convergence maps, and we analyse each systematic effect independently and simultaneously. We show that the KS+ method substantially reduces the errors on the two-point correlation function and moments compared to the KS method. In particular, we show that the errors introduced by the mass inversion on the two-point correlation of the convergence maps are reduced by a factor of about 5, while the errors on the third- and fourth-order moments are reduced by factors of about 2 and 10, respectively.
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