259 research outputs found
Stability mechanisms of high current transport in iron-chalcogenides superconducting films
The improvement in the fabrication techniques of iron-based superconductors
have made these materials real competitors of high temperature superconductors
and MgB. In particular, iron-chalcogenides have proved to be the most
promising for the realization of high current carrying tapes. But their use on
a large scale cannot be achieved without the understanding of the current
stability mechanisms in these compounds. Indeed, we have recently observed the
presence of flux flow instabilities features in Fe(Se,Te) thin films grown on
CaF. Here we present the results of current-voltage characterizations at
different temperatures and applied magnetic fields on Fe(Se,Te) microbridges
grown on CaF. These results will be analyzed from the point of view of the
most validated models with the aim to identify the nature of the flux flow
instabilities features (i.e., thermal or electronic), in order to give a
further advance to the high current carrying capability of iron-chalcogenide
superconductors.Comment: 4 pages, 3 figure
Twenty years of the Italian Fanconi Anemia Registry: where we stand and what remains to be learned
The natural history of Fanconi anemia remains hard to establish because of its rarity and its heterogeneous clinical presentation; since 1994, the Italian Fanconi Anemia Registry has collected clinical, epidemiological and genetic data of Italian Fanconi Anemia patients. This registry includes 180 patients with a confirmed diagnosis of Fanconi anemia who have either been enrolled prospectively, at diagnosis, or later on. After enrollment, follow-up data were periodically collected to assess the clinical course, possible complications and long-term survival; the median follow up was 15.6 years. The main goal of the study was to describe the natural history of Fanconi anemia, focusing on the following variables: family history, disease presentation, development of hematological manifestations, development of malignancies, occurrence of hematopoietic stem cell transplantation and survival. Typical morphological and/or hematological abnormalities and/or growth retardation were the most common manifestations at diagnosis; the majority of patients (77%) exhibited hematological abnormalities at the initial presentation, and almost all (96%) eventually developed hematological manifestations. More than half of the patients (57%) underwent a bone-marrow transplant. The occurrence of cancer was quite rare at diagnosis, whereas the cumulative incidence of malignancies at 10, 20 and 30 years was 5%, 8% and 22%, respectively, for hematological cancers and 1%, 15% and 32%, respectively, for solid tumors. Overall survival at 10, 20 and 30 years were 88%, 56% and 37%, respectively; the main causes of death were cancer, complications of the hematological presentation and complications of transplantation. These data clearly confirm the detrimental outcome of Fanconi anemia, with no major improvement in the past decades
Periprocedural and Short-Term Outcomes of Transfemoral Transcatheter Aortic Valve Implantation With the Sapien XT as Compared With the Edwards Sapien Valve
ObjectivesThe aim of this study was to analyze the short-term outcomes after transcatheter aortic valve implantation with the Edwards Sapien THV (ESV), compared with the Sapien XT THV (SXT) (Edwards Lifesciences, Irvine, California).BackgroundThe SXT has been recently commercialized in Europe, but there are no studies analyzing the efficacy and safety of SXT, compared with ESV.MethodsAll consecutive patients (n = 120) who underwent transcatheter aortic valve implantation in our center via the transfemoral approach with either ESV (n = 66) or SXT (n = 54). Valve Academic Research Consortium endpoints were used.ResultsMean age was 80 ± 8 years, and mean Logistic-European System for Cardiac Operative Risk Evaluation was 24.9 ± 17.0. The ilio-femoral artery minimal lumen diameter was smaller in patients treated with the SXT (7.27 ± 1.09 mm vs. 7.94 ± 1.08 mm, p = 0.002). Device success was high in both groups (96.3% vs. 92.4%, p = 0.45). Major vascular events were 3-fold lower in the SXT group (11.1% vs. 33.3%, relative risk: 0.40, 95% confidence interval: 0.28 to 0.57; p = 0.004). Life-threatening and major bleeding events were not significantly different between groups (18.5% vs. 27.3% and 35.2% vs. 40.9%, respectively). The SXT group had a lower 30-day Valve Academic Research Consortium combined safety endpoint (20.4% vs. 45.5%; relative risk: 0.44, 95% confidence interval: 0.24 to 0.80; p = 0.004). The 30-day mortality was 1.7% (n = 2). At 30 days, mean transaortic gradient was approximately 10 mm Hg in both groups and the aortic regurgitation was mild-to-moderate in 70.2% of SXT and 76.3% of ESV.ConclusionsThe new SXT valve has the same short-term performance as the ESV but seems to be associated with a lower risk of major vascular complications and thus has a broader clinical application
Predictive Value of MRI in Hypoxic-Ischemic Encephalopathy Treated with Therapeutic Hypothermia
Background: Hypoxic-ischemic encephalopathy (HIE) is a severe pathology, and no unique predictive biomarker has been identified. Our aims are to identify associations of perinatal and outcome parameters with morphological anomalies and ADC values from MRI. The secondary aims are to define a predictive ADC threshold value and detect ADC value fluctuations between MRIs acquired within 7 days (MR0) and at 1 year (MR1) of birth in relation to perinatal and outcome parameters. Methods: Fifty-one term children affected by moderate HIE treated with hypothermia and undergoing MRI0 and MRI1 were recruited. Brain MRIs were evaluated through the van Rooij score, while ADC maps were co-registered on a standardized cerebral surface, on which 29 ROIs were drawn. Statistical analysis was performed in Matlab, with the statistical significance value at 0.05. Results: ADC0 < ADC1 in the left and right thalami, left and right frontal white matter, right visual cortex, and the left dentate nucleus of children showing abnormal perinatal and neurodevelopmental parameters. At ROC analysis, the best prognostic ADC cut-off value was 1.535 mm2/s Ă— 10-6 (sensitivity 80%, specificity 86%) in the right frontal white matter. ADC1 > ADC0 in the right visual cortex and left dentate nucleus, positively correlated with multiple abnormal perinatal and neurodevelopmental parameters. The van Rooij score was significantly higher in children presenting with sleep disorders. Conclusions: ADC values could be used as prognostic biomarkers to predict children's neurodevelopmental outcomes. Further studies are needed to address these crucial topics and validate our results. Early and multidisciplinary perinatal evaluation and the subsequent re-assessment of children are pivotal to identify physical and neuropsychological disorders to guarantee early and tailored therapy
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