20 research outputs found

    Establishing the nature of X-ray binaries through infrared spectroscopy

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    European Space Agency's INTEGRAL (International Gamma-Ray Astrophysics Laboratory) satellite have discovered new X-ray sources due to its sensitivity above 20 keV. Most of these sources suffer from high absorption and the classical blue band spectral classification region is normally not accessible. This can be overcome, however, through infrared spectroscopy. The characterisation of these systems can influence the population synthesis models currently in use. In this work, we present the first H and K band spectra for three INTEGRAL sources using the NICS instrument mounted on the Telescopio Nazionale Galileo (TNG) 3.5-m telescope. This study was complemented with infrared photometry from UKIDSS, 2MASS, WISE and NEOWISE databases. Our spectra show all the significant features in emission and are, thus, consistent with a Be nature of the companions. Owing to their X-ray characteristics, these systems were classified as Be X-ray binaries. This allowed us to refine its distances to the sources using suitable calibrations that take into account the contamination by the circumstellar disk.This work was supported partially by the project ESP2017-85691-P AM acknowledges the support by the VIDI de la UA under visiting programme INV17-26

    IGR J19294+1816: a new Be-X-ray binary revealed through infrared spectroscopy

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    The aim of this work is to characterize the counterpart to the INTErnational Gamma-Ray Astrophysics Laboratory high-mass X-ray binary candidate IGR J19294+1816 so as to establish its true nature. We obtained H-band spectra of the selected counterpart acquired with the Near Infrared Camera and Spectrograph instrument mounted on the Telescopio Nazionale Galileo 3.5-m telescope which represents the first infrared spectrum ever taken of this source. We complement the spectral analysis with infrared photometry from UKIDSS, 2MASS, WISE, and NEOWISE data bases. We classify the mass donor as a Be star. Subsequently, we compute its distance by properly taking into account the contamination produced by the circumstellar envelope. The findings indicate that IGR J19294+1816 is a transient source with a B1Ve donor at a distance of d = 11 ± 1 kpc, and luminosities of the order of 1036–37 erg s−1, displaying the typical behaviour of a Be-X-ray binary.Part of this work was supported by the Spanish Ministerio de EconomĂ­a y Competitividad project number ESP2014-53672-C3-3-P. JJRR acknowledges financial support from the Generalitat Valenciana and University of Alicante projects GV/2014/088 and GRE12-35, respectively. AM acknowledges the support by the grant by the Vicerectorat d’InvestigaciĂł, Desenvolupament i InnovaciĂł de la Universitat d’Alacant under visiting researcher programme INV15-10

    Inter-society consensus document on treatment and prevention of bronchiolitis in newborns and infants

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    Acute bronchiolitis is the leading cause of lower respiratory tract infection and hospitalization in children less than 1 year of age worldwide. It is usually a mild disease, but some children may develop severe symptoms, requiring hospital admission and ventilatory support in the ICU. Infants with pre-existing risk factors (prematurity, bronchopulmonary dysplasia, congenital heart diseases and immunodeficiency) may be predisposed to a severe form of the disease. Clinical diagnosis of bronchiolitis is manly based on medical history and physical examination (rhinorrhea, cough, crackles, wheezing and signs of respiratory distress). Etiological diagnosis, with antigen or genome detection to identify viruses involved, may have a role in reducing hospital transmission of the infection. Criteria for hospitalization include low oxygen saturation (<90-92%), moderate-to-severe respiratory distress, dehydration and presence of apnea. Children with pre-existing risk factors should be carefully assessed. To date, there is no specific treatment for viral bronchiolitis, and the mainstay of therapy is supportive care. This consists of nasal suctioning and nebulized 3% hypertonic saline, assisted feeding and hydration, humidified O2 delivery. The possible role of any pharmacological approach is still debated, and till now there is no evidence to support the use of bronchodilators, corticosteroids, chest physiotherapy, antibiotics or antivirals. Nebulized adrenaline may be sometimes useful in the emergency room. Nebulized adrenaline can be useful in the hospital setting for treatment as needed. Lacking a specific etiological treatment, prophylaxis and prevention, especially in children at high risk of severe infection, have a fundamental role. Environmental preventive measures minimize viral transmission in hospital, in the outpatient setting and at home. Pharmacological prophylaxis with palivizumab for RSV bronchiolitis is indicated in specific categories of children at risk during the epidemic period. Viral bronchiolitis, especially in the case of severe form, may correlate with an increased incidence of recurrent wheezing in pre-schooled children and with asthma at school age. The aim of this document is to provide a multidisciplinary update on the current recommendations for the management and prevention of bronchiolitis, in order to share useful indications, identify gaps in knowledge and drive future research

    Hyades Member K2-136c:The Smallest Planet in an Open Cluster with a Precisely Measured Mass

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    International audienceK2-136 is a late-K dwarf (0.742 ± 0.039 M ⊙) in the Hyades open cluster with three known, transiting planets and an age of 650 ± 70 Myr. Analyzing K2 photometry, we found that planets K2-136b, c, and d have periods of 8.0, 17.3, and 25.6 days and radii of 1.014 ± 0.050 R ⊕, 3.00 ± 0.13 R ⊕, and 1.565 ± 0.077 R ⊕, respectively. We collected 93 radial velocity (RV) measurements with the High-Accuracy Radial-velocity Planet Searcher for the Northern hemisphere (HARPS-N) spectrograph (Telescopio Nazionale Galileo) and 22 RVs with the Echelle SPectrograph for Rocky Exoplanets and Stable Spectroscopic Observations (ESPRESSO) spectrograph (Very Large Telescope). Analyzing HARPS-N and ESPRESSO data jointly, we found that K2-136c induced a semi-amplitude of 5.49 ± 0.53 m s-1, corresponding to a mass of 18.1 ± 1.9 M ⊕. We also placed 95% upper mass limits on K2-136b and d of 4.3 and 3.0 M ⊕, respectively. Further, we analyzed Hubble Space Telescope and XMM-Newton observations to establish the planetary high-energy environment and investigate possible atmospheric loss. K2-136c is now the smallest planet to have a measured mass in an open cluster and one of the youngest planets ever with a mass measurement. K2-136c has ~75% the radius of Neptune but is similar in mass, yielding a density of 3.69−0.56+0.67{3.69}_{-0.56}^{+0.67} g cm-3 (~2-3 times denser than Neptune). Mass estimates for K2-136b (and possibly d) may be feasible with more RV observations, and insights into all three planets' atmospheres through transmission spectroscopy would be challenging but potentially fruitful. This research and future mass measurements of young planets are critical for investigating the compositions and characteristics of small exoplanets at very early stages of their lives and providing insights into how exoplanets evolve with time

    Roadmap for Optical Tweezers 2023

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    Optical tweezers are tools made of light that enable contactless pushing, trapping, and manipulation of objects ranging from atoms to space light sails. Since the pioneering work by Arthur Ashkin in the 1970s, optical tweezers have evolved into sophisticated instruments and have been employed in a broad range of applications in life sciences, physics, and engineering. These include accurate force and torque measurement at the femtonewton level, microrheology of complex fluids, single micro- and nanoparticle spectroscopy, single-cell analysis, and statistical-physics experiments. This roadmap provides insights into current investigations involving optical forces and optical tweezers from their theoretical foundations to designs and setups. It also offers perspectives for applications to a wide range of research fields, from biophysics to space exploration

    Obscured BeXRBs through infrared spectroscopy

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    The X-ray Universe 2017, Proceedings of the conference held 6-9 June, 2017 in Rome, Italy. Edited by J.-U. Ness and S. Migliari. Online at https://www.cosmos.esa.int/web/xmm-newton/2017-symposium, p.321The identification and spectral characterization of the optical/infrared counterparts in X-ray binaries is an essential step to understand the physics of these systems. We report on the first infrared spectroscopy of three INTEGRAL X-ray binary sources which present high absorption. Our spectra show that almost all the significant features are in emission, consistent with a Be companion star. We correct the infrared excess taking into account the circumstellar envelope emission in order to obtain a refined estimation of the distance to the X-ray sources and their X-ray luminosities. Based on these results we discuss how their X-ray characteristics fit into the BeX-ray scenario.Project ESP2014-53672-C3-3-P and INV15-10 of U

    Case report on pathogenetic link between gluten and IgA nephropathy

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    Abstract Background A relationship between IgA nephropathy (IgAN) and celiac disease (CD) has been reported. We show the pathogenetic link for the first time. Case presentation A 39-year-old man with cystic fibrosis (CF) and CF-related diabetes started to present gross hematuria, back pain and headache. At admission, laboratory analysis showed increase in serum creatinine of 1.5 mg/dl, together with hematuria and mild proteinuria (1 g/24 h). He underwent a renal biopsy to investigate the cause of hematuria and renal failure. Biopsy was consistent with IgAN. In view of patient reported dyspepsia, an upper gastrointestinal endoscopy with duodenal biopsies was undertaken and was normal. We looked for mucosal deposits of tTG-2 in the duodenum and the renal mesangium. tTG-2 deposits were found both in the duodenum and in renal biopsies, where they topographically replicated mesangial IgA deposits. After one year on a continued gluten containing diet, the patient developed a Marsh 2 type duodenal pathology. Conclusions Our findings suggest a connection between CD and IgAN in terms of an immune-mediated gluten-induced pathogenesis even in the absence of villous atrophy and serum celiac autoantibodies

    Omalizumab therapy in a 13-year-old boy with severe persistent asthma and concomitant eosinophilic esophagitis

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    Background: Eosinophilic esophagitis (EoE) has been defined as "asthma of the esophagus" for the large number of similarities between the two diseases. Omalizumab is an anti-Immunoglobulin E (IgE) antibody currently approved only in allergic IgE-mediated severe persistent uncontrolled asthma and in chronic spontaneous urticaria unresponsive to antihistamines, but it has been tried in other diseases, too. Case presentation: We present herein the case of a 13-year-old boy, affected from preschool age by severe chronic allergic asthma poorly controlled despite a generous long-term therapy, and, since he was 8 years old, by eosinophilic esophagitis, responsive to courses of strict elimination diet and semi-elemental diet, even if very burdensome for his quality of life. At the age of 11.5 years, for inadequate asthma control, he started to receive therapy with omalizumab. After the first month and for the entire duration (18 months) of omalizumab treatment, asthma was well controlled, long-term conventional therapy was gradually withdrawn and lung- function improved. Concerning EoE, after an initial clinical but not histological remission during the first few months of treatment with omalizumab, the patient experienced an exacerbation of gastrointestinal symptoms. Therefore, he started treatment with topical steroids which was effective to improve gastrointestinal symptoms. However, EoE is still steroid-dependent. Currently, he continues both treatments: omalizumab for asthma and topical steroid for EoE. Conclusions: This case report confirms that omalizumab is an effective treatment in patients with severe persistent, uncontrolled asthma. On the other hand, in our patient it did not produce persistent improvement neither on symptoms nor on biopsy findings of EoE. The outcome of this case might indicate different pathogenic mechanism(s) of the two diseases
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