338 research outputs found

    Geology of the Raditladi quadrangle, Mercury (H04)

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    In this work, we present a 1:3,000,000-scale geologic map of the Raditladi quadrangle (H04) of Mercury. The area covers nearly 7% of the entire planet and encompasses several features of interest such as the Caloris basin, the Raditladi basin, hollow clusters and volcanic features. The mapping took advantage of the data produced during MESSENGER's orbital phase. The mapped deposits include impact-related units observed at several scales from the Caloris basin to the secondary crater chains. The Smooth Plains unit covers the majority of the area, mantling the older Intercrater Plains and Bright Intercrater Plains units. Results show that the emplacement of all the main units and the Caloris impact event, representing the main geologic events in the quadrangle, were concentrated between 3.96 and 3.72 Ga. After this intense phase, the geologic framework was modified only by local events such as impact craters and hollow formation. This map is among the first products for the detailed geologic characterization of Mercury at such a scale. It will contribute as a constraint and a support for both further local investigation and mapping, and targeting of the forthcoming BepiColombo ESA/JAXA joint exploration mission to Mercury

    Researchers, trainers and first responders: a synergy for an improved prevention of chemical, biological, radiological and nuclear risks in south-east Asian countries.

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    Italian scientists active in national research and academic institutions have been collaborating since 2013, under the aegis of the EU Chemical, Biological, Radiological and Nuclear (CBRN) Risk Mitigation Centres of Excellence, with governmental stakeholders and technical partners, in nine countries of South-East Asia, in order to enhance the local capabilities in preventing, monitoring and responding to CBRN incidents due to intentional, accidental or natural causes. The initiatives implied training courses, didactical sessions, live simulations, table-top exercises and interactive train-the-trainer sessions, in the presence of European and local experts, with trans-disciplinary competences covering areas such as chemistry, biology, toxicology, medicine, engineering, law and international right

    Clinical observations and risk factors for tinnitus in a Sicilian cohort

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    The aims of this study were to determine the distribution of risk factors associated with tinnitus analysing their role in the development of tinnitus and the effects of their interaction; to evidence the importance of a suitable and adequate clinical and audiologic assessment to avoid those modifiable risk factors responsible for cochlear dysfunction and tinnitus onset. 46 subjects with tinnitus and 74 controls were studied according to: age, sex, Body Mass Index (BMI), neck circumference, tobacco smoking, feeling fatigue or headache, self reporting snoring, hypertension, diabetes, coronary heart disease, and/or hyperlipidemia, and laboratory finding as lipid profile and levels of reactive oxygen metabolites (d-ROM). Audiological assessment was performed by multi-frequency audiometry (PTA0.5–16 kHz) and transient-evoked otoacoustic emissions (TEOAE diagnostic). Univariate analysis was performed to examine the association between determinants and occurrence of tinnitus; Mantel–Haenszel test (G.or) was used to investigate the joint effect of determinants on tinnitus. Tinnitus was more frequent among males with age [50 years; BMI[30 kg/m2, neck circumference[40 cm, headache, hypertension, hypercholesterolemia resulted significant risk factors for tinnitus (P.0001). Tinnitus group had more comorbidity (P.0001) and worse audiometric thresholds (60.87 Vs 21.62 % hearing loss; P.0001) with respect to control group. The interaction between hypertension–BMI C 30 kg/m2 (G.or = 8.45) and smoking–hypercholesterolemia (G.or = 5.08) increases the risk of tinnitus (P.0001). Our results underline that several factors either individually or jointly contribute to tinnitus onset; a comprehensive knowledge about tinnitus risk factors and associated clinical conditions could contribute to minimizing this disorder

    The addition of simvastatin administration to cold storage solution of explanted whole liver grafts for facing ischemia/reperfusion injury in an area with a low rate of deceased donation: a monocentric randomized controlled double-blinded phase 2 study.

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    BACKGROUND: Liver transplantation is the best treatment for end-stage liver disease. The interruption of the blood supply to the donor liver during cold storage damages the liver, affecting how well the liver will function after transplant. The drug Simvastatin may help to protect donor livers against this damage and improve outcomes for transplant recipients. The aim of this study is to evaluate the benefits of treating the donor liver with Simvastatin compared with the standard transplant procedure. PATIENT AND METHODS: We propose a prospective, double-blinded, randomized phase 2 study of 2 parallel groups of eligible adult patients. We will compare 3-month, 6-month, and 12-month graft survival after LT, in order to identify a significant relation between the two homogenous groups of LT patients. The two groups only differ by the Simvastatin or placebo administration regimen while following the same procedure, with identical surgical instruments, and medical and nursing skilled staff. To reach these goals, we determined that we needed to recruit 106 patients. This sample size achieves 90% power to detect a difference of 14.6% between the two groups survival using a one-sided binomial test. DISCUSSION: This trial is designed to confirm the effectiveness of Simvastatin to protect healthy and steatotic livers undergoing cold storage and warm reperfusion before transplantation and to evaluate if the addition of Simvastatin translates into improved graft outcomes. TRIAL REGISTRATION: ISRCTN27083228

    Thermal stability of water ice in Ceres' crater Oxo

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    Dwarf planet Ceres, target of the NASA Dawn mission, exhibits evidences of ammoniated phyllosilicates on its surface [1], compatible with a likely outer Solar System origin. Considerable amounts of water ice have recently been detected in some craters by the Visible InfraRed mapping spectrometer (VIR) onboard Dawn in some small fresh crater, such as Oxo, located at about 40° N. The exposure mechanism of water ice is unknown: cryovolcanism, cometary type sublimation/recondensation [2]or impacts with other bodies are likely mechanisms. The evaluation of the time stability of the water ice is crucial to understand the plausible mechanism for its existence. For this purpose, we developed a 3D finite-elements model (FEM) by using the topography given by the shape model of Ceres derived on the basis of images acquired by the Framing Camera in the Survey mission phase. The illumination conditions are provided by the SPICE toolkit. We performed several simulations by analyzing the effect of thermal inertia and albedo on the temperature and rate of ice sublimation. The results of the simulations about the stability of water ice will be presented.[1] De Sanctis et al. NATURE, doi:10.1038/nature16172[2] Formisano et al. MNRAS, doi: 10.1093/mnras/stv234

    (1) Ceres: Study of Thermal Convection in the Mantle and its Mechanical Effects

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    Ceres is the largest body of the Main Belt, which is characterized by a huge abundance of water ice in its interior. This feature is suggested by its relatively low bulk density (2162 kg m-3, Russell et al. 2016, Park et al. 2016) and by several geological and geochemical evidences (specific minerals or salts produced by acqueous alteration, icy patches on the surface, lobate morphologies interpretable as surface flows (De Sanctis et al. 2016, Carrozzo et al. 2018, Raponi et al. 2018, Zolotov 2017 and Schmidt et al., 2017).Ceres is partially differentiated as suggested by its normalized moment of inertia, 0.37 (Park et al. 2016). A typical internal structure proposed for Ceres is: a rocky core (300-350 km), an icy (or muddy) mantle (100-150 km) and a rocky crust some kilometers in depth (eg. Mc Cord & Sotin 2005, Neveu & Desch, 2015). The temperature gradient across the mantle, estimated through numerical modelling (e.g. McCord & Sotin 2005, Neveu & Desch 2015) would be large enough to initiate a thermal convection in the mantle. Since the mantle is not uniquely defined from a composition point of view, in this work we explore how the composition and, in particular the "degree" of muddiness of the mantle, can influence the characteristic of thermal convection. We also estimate the thickness of the top conductive boundary layer and the mechanical stress, which can cause its deformation. - De Sanctis, M., et al. (2015) doi:10.1038/nature16172.- Russell, C., et al. (2016), doi:10.1126/science.aaf4219.- Park, R., et al. (2016),Lunar and Planetary Science Conference, vol. 47, p. 1781.- Schmidt, B. E., et al. (2017), doi:doi:10.1038/ngeo2936- Zolotov, M. Y. (2017), doi:https://doi.org/10.1016 j.icarus.2017.06.018.- Carrozzo, F., et al. (2018), Nature, formation and distribution of carbonates on ceres, Science Advances.- Raponi, A., et al. (2018), Variations in the amount of water ice on ceres' surface suggest a seasonal water cycle, Science Advances.- McCord, T., and C. Sotin (2005), doi:10.1029/2004JE002244.- Neveu, M., and S. Desch (2015), Geochemistry, thermal evolution, and cryovolcanism on Ceres with a muddy ice mantle, Geophys. Res. Lett

    A study regarding the stability of the primordial crust of asteroid Ceres

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    Ceres is a particular object of the solar system, since it is a "transition body" between the icy satellites of the outer solar system and the rocky bodies of the inner part. Probably it is differentiated [1,2], i.e. it has a core made of "rock" (silicates) with a weak presence of metals, a large icy mantle and a rocky crust. In particular, it has been proposed the existence on the surface of the ammoniated phyllosilicates, compatible with an outer solar system origin [3]. Also water in clay minerals, brucite, and iron-rich serpentine have been proposed to exist on the surface [4]. Ice directly on the surface regolith seems to be very unstable: numerical simulations of [5] indicate that it can last for very few orbits. A crust made of a mixture of ice and rock is potentially unstable. In the solar system, for example, Callisto has such a crust but its surface temperature is below the critical temperature for the Rayleigh-Taylor instability [6]: this seems not to be the case of Ceres. In this work, we verify the stability of the primordial crust, by assuming a certain initial composition (ice and rock) and thickness. We assume a post-differentiation Ceres, made of three layers (rocky core, icy mantle and crust). The key role is played by the viscosity of the layers, which influenced the survival or not of the primordial crust. We applied the method of the parametrized thermal convection widely diffused in literature. [1] McCord, T.B. and Sotin, C., 2005, JGR 110 [2] Castillo-Rogez, J.C., and McCord, T.B., 2010, Icarus 205, 443-459 [3] De Sanctis, M.C. et al., 2015, doi:10.1038/nature16172 [4] Rivkin, A.S., et al., 2014, Space Sci Rev, 95-116, 163, doi 10.1007/s11214-010-9677-4 [5] Formisano, M., et al., 2016, MRAS 455, 1892-1904 [6] Shoji, D. and Kurita, K., 2014, doi:10.1002/2014JE004695

    Hodgkin's disease presenting below the diaphragm. The experience of the Gruppo Italiano Studio Linfomi (GISL)

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    Background and Objective. Infradiaphragmatic Hodgkin\ub4s disease is rare, making up 5-12% of cases in clinical stages I and II; consequently, several questions concerning prognosis and treatment strategy remain to be answered. The aim of this study was to analyze the clinical and prognostic characteristics and outcome of his condition. Methods. A series of 282 patients with CS I-II Hodgkin\ub4s disease (HD) was investigated. In 31 patients the disease was confined below the diaphragm (BDHD), and in the remaining above the diaphragm (ADHD). The presenting features and outcomes were compared in the two groups. Results. The BDHD group was older (p < 0.0002), had a higher frequency of males (p < 0.08) and a different histological subtype group distribution (p < 0.0001). Stage II BDHD patients had a worse overall survival rate (OS) than stage II ADHD patients (68.8% vs 86.6% at 8 years, p < 0.01) if age is not considered; patients with more than 40 years of age, in fact, had the same survival rates as those with ADHD. BDHD patients with intra-abdominal disease alone had worse prognostic factors and OS (p = 0.12) than patients with inguinal-femoral nodes. Interpretation and Conclusions. Although BDHD patients present distinct features, they have the same OS and relapse-free survival rate as age-adjusted ADHD patients. According to our experience patients with stage I peripheral BDHD respond well to radiotherapy-based regimens. Those with stage II and or intra-abdominal disease are more challenging; chemotherapy or a combined therapy seem to be more suitable approaches for these patients
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