412 research outputs found

    A critical fractional equation with concave-convex power nonlinearities

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    none4sìIn this work we study a fractional critical problem with concave-convex nonlinearities. Our main results show the existence and multiplicity of solutions to this problem for different values of the real parameter appearing in the equation. The dependency on this parameter changes according to whether we consider the concave power case or the convex power case. These two cases will be treated separatelyopenBarrios B; Colorado E; Servadei R; Soria FBarrios, B; Colorado, E; Servadei, Raffaella; Soria, F

    Dandy-Walker malformation: is the "tail sign" the key sign?

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    OBJECTIVE.To demonstrate the value of the "tail sign" in the assessment of Dandy-Walker Malformation (DWM). METHODS: A total of 31fetal MRI, performed before 24 weeks of gestation after second-line US examination between May 2013 and September 2014, were examined retrospectively. All MRI examinations were performed using a 1.5 Tesla magnet without maternal sedation. RESULTS: MRI diagnosed 15/31 cases of Dandy-Walker Malformation, 6/31 cases of vermian partial caudal agenesis, 2/31 of vermian hypoplasia, 4/31 of vermian malrotation, 2/31 of Walker-Warburg Syndrome, 1/31 of Blake pouch cyst, 1/31 of rhombencephalosynapsis. All data were compared with fetopsy results, Fetal MR after the 30th week or postnatal MRI; the follow up depended on the maternal decision to terminate or continue pregnancy. In our review study we found the presence of the "tail sign"; this sign was visible only in Dandy-Walker Malformation and Walker-Warburg Syndrome. CONCLUSION: The "tail sign" could be helpful in the difficult differential diagnosis between Dandy Walker, vermian malrotation, vermian hypoplasia and vermian partial agenesis

    Development of UHTCMCs via water based ZrB2 powder slurry infiltration and polymer infiltration and pyrolysis

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    Cf/ZrB2-SiC ultra-high temperature composites were manufactured via aqueous slurry impregnation coupled with polymer infiltration and pyrolysis, using a allylhydrido polycarbosilane precursor. For the first time we used ultra-high modulus pitch-based carbon fibres for the PIP process, investigating three different architectures, 0/0°, 0/90°, and 2D. Microstructure, mechanical properties and oxidation resistance in air at 1650 °C were investigated. As expected, the mechanical properties showed the tendency to decrease with increase of the preforms complexity, due to the higher amount of flaws and residual stresses. For instance, the flexural strength was approaching 500 MPa for 0/0°, 370 MPa for 0/90° and 190 MPa for 2D. The materials showed an optimal resistance to oxidation at 1650 °C thanks to formation of a viscous borosilicate glass that guaranteed a self-healing functionality

    Using Abbreviated Injury Scale (AIS) codes to classify Computed Tomography (CT) features in the Marshall System

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    <p>Abstract</p> <p>Background</p> <p>The purpose of Abbreviated Injury Scale (AIS) is to code various types of Traumatic Brain Injuries (TBI) based on their anatomical location and severity. The Marshall CT Classification is used to identify those subgroups of brain injured patients at higher risk of deterioration or mortality. The purpose of this study is to determine whether and how AIS coding can be translated to the Marshall Classification</p> <p>Methods</p> <p>Initially, a Marshall Class was allocated to each AIS code through cross-tabulation. This was agreed upon through several discussion meetings with experts from both fields (clinicians and AIS coders). Furthermore, in order to make this translation possible, some necessary assumptions with regards to coding and classification of mass lesions and brain swelling were essential which were all approved and made explicit.</p> <p>Results</p> <p>The proposed method involves two stages: firstly to determine all possible Marshall Classes which a given patient can attract based on allocated AIS codes; via cross-tabulation and secondly to assign one Marshall Class to each patient through an algorithm.</p> <p>Conclusion</p> <p>This method can be easily programmed in computer softwares and it would enable future important TBI research programs using trauma registry data.</p

    Access to Reliable Information about Long-Term Prognosis Influences Clinical Opinion on Use of Lifesaving Intervention

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    Background: Decompressive craniectomy has been traditionally used as a lifesaving rescue treatment in severe traumatic brain injury (TBI). This study assessed whether objective information on long-term prognosis would influence healthcare workers ’ opinion about using decompressive craniectomy as a lifesaving procedure for patients with severe TBI. Method: A two-part structured interview was used to assess the participants ’ opinion to perform decompressive craniectomy for three patients who had very severe TBI. Their opinion was assessed before and after knowing the predicted and observed risks of an unfavourable long-term neurological outcome in various scenarios. Results: Five hundred healthcare workers with a wide variety of clinical backgrounds participated. The participants were significantly more likely to recommend decompressive craniectomy for their patients than for themselves (mean difference in visual analogue scale [VAS] 21.5, 95 % confidence interval 21.3 to 21.6), especially when the next of kin of the patients requested intervention. Patients ’ preferences were more similar to patients who had advance directives. The participants’ preferences to perform the procedure for themselves and their patients both significantly reduced after knowing the predicted risks of unfavourable outcomes, and the changes in attitude were consistent across different specialties, amount of experience in caring for similar patients, religious backgrounds, and positions in the specialty of the participants. Conclusions: Access to objective information on risk of an unfavourable long-term outcome influenced healthcare workers
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