596 research outputs found

    The puzzling symbiotic X-ray system 4U1700+24

    Full text link
    Symbiotic X-ray binaries form a subclass of low-mass X-ray binary systems consisting of a neutron star accreting material from a red giant donor star via stellar wind or Roche lobe overflow. Only a few confirmed members are currently known; 4U 1700+24 is a good candidate as it is a relatively bright X-ray object, possibly associated with the late-type star V934 Her. We analysed the archive {\it XMM}-Newton and Swift/XRT observations of 4U 1700+24 in order to have a uniform high-energy (0.3−100.3-10 keV) view of the source. We confirmed the existence of a red-shifted O VIII Ly-α\alpha transition (already observed in the 2002 {\it XMM}-Newton data) in the high-resolution spectra collected via the RGS instruments. The red-shift of the line is found in all the analysed observations and, on average, it was estimated to be ≃0.009\simeq 0.009. We also observed a modulation of the centroid energy of the line on short time scales (a few days) and discuss the observations in the framework of different scenarios. If the modulation is due to the gravitational red-shift of the neutron star, it might arise from a sudden re-organization of the emitting XX-ray matter on the scale of a few hundreds of km. Alternatively, we are witnessing a uni-polar jet of matter (with typical velocity of 1000−40001000-4000 km s−1^{-1}) possibly emitted by the neutron star in an almost face-on system. The second possibility seems to be required by the apparent lack of any modulation in the observed XX-ray light curve. We also note also that the low-resolution spectra (both {\it XMM}-Newton and Swift/XRT in the 0.3−100.3-10 keV band) show the existence of a black body radiation emitted by a region (possibly associated with the neutron star polar cap) with typical size from a few tens to hundreds of meters. The size of this spot-like region reduces as the overall luminosity of 4U 1700+24 decreases.Comment: In press on A&

    Digital approach for the rehabilitation of the edentulous maxilla with pterygoid and standard implants: The static and dynamic computer-aided protocols

    Get PDF
    A full-arch rehabilitation of the edentulous upper jaw without grafting procedures exploits the residual alveolar or the basal bone, with the necessity of long implants placed with a particular orientation. The precision in planning and placing the fixtures is fundamental to avoid clinical problems and to allow an acceptable connection with the prosthesis. The computer-aided implantology resulted in more accuracy than the traditional one, with a high standard of correspondence between the virtual project and the real outcome. This paper reports about the two different digital protocols, static and dynamic, as support to implant-borne prosthetic rehabilitation of edentulous maxillae. Two pterygoid and two/four anterior standard implants were seated in both cases by two different operators, without flap raising, and immediately loaded. This approach avoided the posterior cantilever by-passing the maxillary sinus and was adequately planned and realized without any surgical or prosthetic error. The two digital flow-charts were described step by step, underlining each other’s advantages and drawbacks compared to a free-hand approach

    Tracking the evolution of riverbed morphology on the basis of uav photogrammetry

    Get PDF
    Unmanned aerial vehicle (UAV) photogrammetry has recently become a widespread technique to investigate and monitor the evolution of different types of natural processes. Fluvial geomorphology is one of such fields of application where UAV potentially assumes a key role, since it allows for overcoming the intrinsic limits of satellite and airborne-based optical imagery on one side, and in situ traditional investigations on the other. The main purpose of this paper was to obtain extensive products (digital terrain models (DTMs), orthophotos, and 3D models) in a short time, with low costs and at a high resolution, in order to verify the capability of this technique to analyze the active geomorphic processes on a 12 km long stretch of the French–Italian Roia River at both large and small scales. Two surveys, one year apart from each other, were carried out over the study area and a change detection analysis was performed on the basis of the comparison of the obtained DTMs to point out and characterize both the possible morphologic variations related to fluvial dynamics and modifications in vegetation coverage. The results highlight how the understanding of different fluvial processes may be improved by appropriately exploiting UAV-based products, which can thus represent a low-cost and non-invasive tool to crucially support decisionmakers involved in land management practices

    Proline enantiomers discrimination by (L)-prolinated porphyrin derivative Langmuir-Schaefer films: proof of concept for chiral sensing applications

    Get PDF
    A porphyrin derivative functionalized with the L-enantiomer of proline amino acid was characterized at the air-pure water interface of the Langmuir trough. The porphyrin derivative was dissolved in dichloromethane solution, spread at the air-subphase interface and investigated by acquiring the surface pressure vs. area per molecule Langmuir curves. It is worth observing that the behavior of the molecules of the porphyrin derivative floating film was substantially influenced by the presence of L-proline amino acid dissolved in the subphase (10(-5) M); on the contrary, the physical chemical features of the floating molecules were only slightly influenced by the D-proline dissolved in the subphase. Such an interesting chirality-driven selection was preserved when the floating film was transferred onto solid supports by means of the Langmuir-Schaefer method, but it did not emerge when a spin-coating technique was used for the layering of the tetrapyrrolic derivatives. The obtained results represent proof of concept for the realization of active molecular layers for chiral discrimination: porphyrin derivatives, due to their intriguing spectroscopic and supramolecular properties, can be functionalized with the chiral molecule that should be detected. Moreover, the results emphasize the crucial role of the deposition technique on the features of the sensing layers

    Proline Enantiomers Discrimination by (L)-Prolinated Porphyrin Derivative Langmuir–Schaefer Films: Proof of Concept for Chiral Sensing Applications

    Get PDF
    A porphyrin derivative functionalized with the L-enantiomer of proline amino acid was characterized at the air–pure water interface of the Langmuir trough. The porphyrin derivative was dissolved in dichloromethane solution, spread at the air–subphase interface and investigated by acquiring the surface pressure vs. area per molecule Langmuir curves. It is worth observing that the behavior of the molecules of the porphyrin derivative floating film was substantially influenced by the presence of L-proline amino acid dissolved in the subphase (10−5 M); on the contrary, the physical chemical features of the floating molecules were only slightly influenced by the D-proline dissolved in the subphase. Such an interesting chirality-driven selection was preserved when the floating film was transferred onto solid supports by means of the Langmuir–Schaefer method, but it did not emerge when a spin-coating technique was used for the layering of the tetrapyrrolic derivatives. The obtained results represent proof of concept for the realization of active molecular layers for chiral discrimination: porphyrin derivatives, due to their intriguing spectroscopic and supramolecular properties, can be functionalized with the chiral molecule that should be detected. Moreover, the results emphasize the crucial role of the deposition technique on the features of the sensing layers

    Reduced AKT/mTOR signaling and protein synthesis dysregulation in a Rett syndrome animal model.

    Get PDF
    Rett syndrome (RTT) is a neurodevelopmental disorder with no efficient treatment that is caused in the majority of cases by mutations in the gene methyl-CpG binding-protein 2 (MECP2). RTT becomes manifest after a period of apparently normal development and causes growth deceleration, severe psychomotor impairment and mental retardation. Effective animal models for RTT are available and show morphofunctional abnormalities of synaptic connectivity. However, the molecular consequences of MeCP2 disruption leading to neuronal and synaptic alterations are not known. Protein synthesis regulation via the mammalian target of the rapamycin (mTOR) pathway is crucial for synaptic organization, and its disruption is involved in a number of neurodevelopmental diseases. We investigated the phosphorylation of the ribosomal protein (rp) S6, whose activation is highly dependent from mTOR activity. Immunohistochemistry showed that rpS6 phosphorylation is severely affected in neurons across the cortical areas of Mecp2 mutants and that this alteration precedes the severe symptomatic phase of the disease. Moreover, we found a severe defect of the initiation of protein synthesis in the brain of presymptomatic Mecp2 mutant that was not restricted to a specific subset of transcripts. Finally, we provide evidence for a general dysfunction of the Akt/mTOR, but not extracellular-regulated kinase, signaling associated with the disease progression in mutant brains. Our results indicate that defects in the AKT/mTOR pathway are responsible for the altered translational control in Mecp2 mutant neurons and disclosed a novel putative biomarker of the pathological process. Importantly, this study provides a novel context of therapeutic interventions that can be designed to successfully restrain or ameliorate the development of RTT

    Imported and Indigenous cases of Invasive Meningocococcal Disease W:P1.5,2:F1-1: ST-11 in migrants' reception centers. Italy, June-November 2014.

    Get PDF
    We report about three unliked cases of meningococcal meningitis caused by the ST-11/ET-37 strain of Neisseria meningitidis serogroup W. Two of the three cases, detected in Sicily on June and July 2014, were migrants from Mali and Eritrea. The third case was a fatal meningitis occurred on November 2014 in a 37 years old man, working in an immigrant center in Calabria. This report suggests that tetravalent conjugate vaccines (ACYW) should be actively offered to the staff of migrants\u2019 reception centers

    Hospital discharges-based search of acute flaccid paralysis cases 2007-2016 in Italy and comparison with the National Surveillance System for monitoring the risk of polio reintroduction

    Get PDF
    Background: Acute flaccid paralysis (AFP) surveillance has been adopted globally as a key strategy for monitoring the progress of the polio eradication initiative. Hereby, to evaluate the completeness of the ascertainment of AFP cases in Italy, a hospital-discharges based search was carried out. Methods: AFP cases occurring between 2007 and 2016 among children under 15 years of age were searched in the Italian Hospital Discharge Records (HDR) database using specific ICD-9-CM diagnostic codes. AFP cases identified between 2015 and 2016 were then compared with those notified to the National Surveillance System (NSS). Results: Over a 10-year period, 4163 hospital discharges with diagnosis of AFP were reported in Italy. Among these, 956 (23.0%) were acute infective polyneuritis, 1803 (43.3%) myopathy, and 1408 (33.8%) encephalitis, myelitis and encephalomyelitis. During the study period, a decreasing trend was observed for all diagnoses and overall the annual incidence rate (IR) declined from 5.5 to 4.5 per 100,000 children. Comparing NSS with HDR data in 2015-2016, we found a remarkable underreporting, being AFP cases from NSS only 14% of those recorded in HDR. In particular, the acute infective polyneuritis cases reported to NSS accounted for 42.6% of those detected in HDR, while only 0.9% of myopathy cases and 13.1% of encephalitis/myelitis/encephalomyelitis cases have been notified to NSS. The highest AFP IRs per 100,000 children calculated on HDR data were identified in Liguria (17.4), Sicily (5.7), and Veneto (5.1) Regions; regarding the AFP notified to the NSS, 11 out of 21 Regions failed to reach the number of expected cases (based on 1/100,000 rate), and the highest discrepancies were observed in the Northern Regions. Overall, the national AFP rate was equal to 0.6, therefore did not reach the target value. Conclusions: AFP surveillance data are the final measure of a country's progress towards polio eradication. The historical data obtained by the HDR have been useful to assess the completeness of the notification data and to identify the Regions with a low AFP ascertainment rate in order to improve the national surveillance system

    Management of a Complex Case during COVID-19 Time Using One-day Digital Dentistry: A Case Report

    Get PDF
    Aim and objective: The aim of the present case report is to describe the digital management of an implant prosthetic rehabilitation performed by the use of different digital technologies, which allowed to successfully perform in 1 day both the surgical and the prosthetical stages with a minimally invasive approach and a high standard of care. Background: Coronavirus disease-2019 (COVID-19) pandemic is affecting dental everyday practice. Clinicians have to reduce the number of patients per day and the time they spend in the dental office. Minimally invasive and digital approaches, with less possible exposure and interaction, are suggested to reduce the risk of infection. Case description: The failure of a short-span implant prosthetic rehabilitation combined with pain and mobility of the involved teeth was the main complaint reported by a 78-year-old male patient, who asked an urgent appointment to solve the problem. An intraoral scanner allowed the clinician to immediately take a preliminary digital impression of the arch to be treated. The resulting 3D files were sent by e-mail to the dental technician who provided a digital wax-up for the computerized workflow. Computer-aided implantology (CAI) performed using an in-office cone-beam computed tomography (CBCT) allowed clinician to guide the surgical approach in a prosthetic manner. Such an integration inside a well-defined workflow was the key for a successful and rapid treatment. Conclusion: By using new innovative digital technology, the treatment was completed in 1 day, reducing the risk of COVID-19 by limiting the number of appointments and reducing contacts in confined environments like the dental office and public transportations. It also helped to reduce materials production and people movement in the treatment of dental emergency. Clinical significance: The possibility of performing an effective treatment saving time by using efficient technology and a minimally invasive procedure highlights the importance of digital planning in order to optimize every single step of the treatment. Digital workflow reduces also the movement of potentially infected materials from the office to the dental laboratory

    Janus effect of glucocorticoids on differentiation of muscle fibro/adipogenic progenitors

    Get PDF
    Muscle resident fibro-adipogenic progenitors (FAPs), support muscle regeneration by releasing cytokines that stimulate the differentiation of myogenic stem cells. However, in non-physiological contexts (myopathies, atrophy, aging) FAPs cause fibrotic and fat infiltrations that impair muscle function. We set out to perform a fluorescence microscopy-based screening to identify compounds that perturb the differentiation trajectories of these multipotent stem cells. From a primary screen of 1,120 FDA/EMA approved drugs, we identified 34 compounds as potential inhibitors of adipogenic differentiation of FAPs isolated from the murine model (mdx) of Duchenne muscular dystrophy (DMD). The hit list from this screen was surprisingly enriched with compounds from the glucocorticoid (GCs) chemical class, drugs that are known to promote adipogenesis in vitro and in vivo. To shed light on these data, three GCs identified in our screening efforts were characterized by different approaches. We found that like dexamethasone, budesonide inhibits adipogenesis induced by insulin in sub-confluent FAPs. However, both drugs have a pro-adipogenic impact when the adipogenic mix contains factors that increase the concentration of cAMP. Gene expression analysis demonstrated that treatment with glucocorticoids induces the transcription of Gilz/Tsc22d3, an inhibitor of the adipogenic master regulator PPARγ, only in anti-adipogenic conditions. Additionally, alongside their anti-adipogenic effect, GCs are shown to promote terminal differentiation of satellite cells. Both the anti-adipogenic and pro-myogenic effects are mediated by the glucocorticoid receptor and are not observed in the presence of receptor inhibitors. Steroid administration currently represents the standard treatment for DMD patients, the rationale being based on their anti-inflammatory effects. The findings presented here offer new insights on additional glucocorticoid effects on muscle stem cells that may affect muscle homeostasis and physiology
    • …
    corecore