8,277 research outputs found

    On Words with the Zero Palindromic Defect

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    We study the set of finite words with zero palindromic defect, i.e., words rich in palindromes. This set is factorial, but not recurrent. We focus on description of pairs of rich words which cannot occur simultaneously as factors of a longer rich word

    Long-term prediction of adherence to continuous positive air pressure therapy for the treatment of moderate/severe obstructive sleep apnea syndrome

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    BACKGROUND: Continuous positive airway pressure (CPAP) therapy is a highly effective treatment for obstructive sleep apnea syndrome (OSAS). However, poor adherence is a limiting factor, and a significant proportion of patients are unable to tolerate CPAP. The aim of this study was to determine predictors of long-term non-compliance with CPAP. METHODS: CPAP treatment was prescribed to all consecutive patients with moderate or severe OSAS (AHI ≥15 events/h) (n = 295) who underwent a full-night CPAP titration study at home between February 1, 2002 and December 1, 2016. Adherence was defined as CPAP use for at least 4 h per night and five days per week. Subjects had periodical follow-up visits including clinical and biochemical evaluation and assessment of adherence to CPAP. RESULTS: Median follow-up observation was 74.8 (24.2/110.9) months. The percentage of OSAS patients adhering to CPAP was 41.4% (42.3% in males and 37.0% in females), and prevalence was significantly higher in severe OSAS than in moderate (51.8% vs. 22.1%; p < 0.001; respectively). At multivariate analysis, lower severity of OSAS (HR = 0.66; CI 95 0.46-0.94) p < 0.023), cigarette smoking (HR = 1.72; CI 95 1.13-2.61); p = 0.011), and previous cardiovascular events (HR = 1.95; CI 95 1.03-3.70; p = 0.04) were the only independent predictors of long-term non-adherence to CPAP after controlling for age, gender, and metabolic syndrome. CONCLUSIONS: In our cohort of patients with moderate/severe OSAS who were prescribed CPAP therapy, long-term compliance to treatment was present in less than half of the patients. Adherence was positively associated with OSAS severity and negatively associated with cigarette smoking and previous cardiovascular events at baseline

    Oxidative/nitrative stress in the pathogenesis of systemic sclerosis: are antioxidants beneficial?

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    Systemic sclerosis (SSc) is a multisystem autoimmune disease: characterised from the clinical side by progressive vasculopathy and fibrosis of the skin and different organs and from the biochemical side by fibroblast deregulation with excessive production of collagen and increased expression of nicotinamide adenine dinucleotide phosphate oxidase 4 (NOX4). The latter contributes to an overproduction of reactive oxygen species that through an autocrine loop maintains NOX4 in a state of activation. Reactive oxygen and nitrogen species are implicated in the origin and perpetuation of several clinical manifestations of SSc having vascular damage in common; attempts to dampen oxidative and nitrative stress through different agents with antioxidant properties have not translated into a sustained clinical benefit. Objective of this narrative review is to describe the origin and clinical implications of oxidative and nitrative stress in SSc, with particular focus on the central role of NOX4 and its interactions, to re-evaluate the antioxidant approaches so far used to limit disease progression, to appraise the complexity of antioxidant treatment and to touch on novel pathways elements of which may represent specific treatment targets in the not so distant future.info:eu-repo/semantics/publishedVersio

    Radon mitigation during the installation of the CUORE 0νββ0\nu\beta\beta decay detector

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    CUORE - the Cryogenic Underground Observatory for Rare Events - is an experiment searching for the neutrinoless double-beta (0νββ0\nu\beta\beta) decay of 130^{130}Te with an array of 988 TeO2_2 crystals operated as bolometers at \sim10 mK in a large dilution refrigerator. With this detector, we aim for a 130^{130}Te 0νββ0\nu\beta\beta decay half-life sensitivity of 9×10259\times10^{25} y with 5 y of live time, and a background index of 102\lesssim 10^{-2} counts/keV/kg/y. Making an effort to maintain radiopurity by minimizing the bolometers' exposure to radon gas during their installation in the cryostat, we perform all operations inside a dedicated cleanroom environment with a controlled radon-reduced atmosphere. In this paper, we discuss the design and performance of the CUORE Radon Abatement System and cleanroom, as well as a system to monitor the radon level in real time.Comment: 10 pages, 6 figures, 1 tabl

    Isoprostane in systemic sclerosis: a systematic review and meta-analysis

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    Objectives: To further the knowledge of oxidative stress in systemic sclerosis (SSc), we performed a systematic review and meta-analysis on studies measuring isoprostane, a vasoactive agent deriving from arachidonic acid and implicated in the vasculopathy of SSc. Methods: Systematic search following the PRISMA guidelines in PubMed and EMBASE between January-1990/December-2017 using the terms: oxidative stress, isoprostane, systemic sclerosis and scleroderma. Results: After the screening process, 8 studies including 240 SSc patients and 192 controls were included in the systematic review and meta-analysis, 6 investigating urinary and 2 serum isoprostane: random effect meta-analysis revealed isoprostane overgeneration in SSc (p <.001) with wide heterogeneity (I 2 = 75%). Subgroup analysis on urinary isoprostane favoured excess excretion in SSc (p =.009) with slightly lower heterogeneity (I 2 = 67%); further subgroup analysis according to unit of measurement revealed no increased isoprostane excretion when expressed as pg/mg creatinine but increased when expressed as pmol/mmol creatinine (p =.05) with medium heterogeneity (I 2 = 32%). Subgroup analysis on serum isoprostane favoured overproduction in SSc (p <.0001) with no heterogeneity. Conclusion: There is some evidence for isoprostane overgeneration in SSc that confirms the occurrence of oxidative stress in this setting: further prospective studies with specified outcomes are needed to evaluate the prognostic value of this functional biomarker

    Antiphospholipid antibodies and renal transplant: a systematic review and meta-analysis

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    Objective: To evaluate the effect of antiphospholipid antibodies (aPL) on renal allograft outcome after kidney transplantation. Methods: A systematic search of EMBASE and PubMed databases from inception to July 2018 was run according to PRISMA guidelines; Peto's odds ratio (OR) for rare events was used for the meta-analysis. Results: Our inclusion/exclusion criteria were met by 22 cohort studies having different outcomes: allograft thrombosis (n = 9) and thromboprophylaxis (n = 3), allograft loss from any cause (n = 9), allograft malfunction (n = 3), duration (n = 2), glomerular filtration rate at 1 year (n = 3) and allograft rejection (n = 5). The pooled prevalence of allograft thrombosis and of thrombotic microangiopathy was greater in aPL+ve than negative recipients (10.4% vs 1.7%, p < 0.0001 and 10.2% vs 0%, p = 0.005, respectively). The pooled prevalence of allograft thrombosis was 75% in patients not taking anticoagulation whereas none of the anticoagulated recipients developed thrombosis (p < 0.0001). The pooled prevalence of allograft loss was greater in aPL+ve recipients (28% vs 18% respectively, p < 0.0001); the pooled prevalence of aPL was greater in allograft loss recipients compared to those who did not lose it (51% vs 33%, p < 0.0001). The pooled prevalence of allograft malfunction and rejection was similar in aPL−ve and aPL+ve recipients (32.2% vs 40.3% and 14.9% vs 14.4%, respectively) but graft duration was shorter in aPL+ve than aPL−ve recipients (p = 0.001) and glomerular filtration rate at 1 year was lower in aPL + ve than aPL−ve recipients (p < 0.0001). Conclusion: APL relate strongly to allograft thrombosis, loss and duration but not to allograft malfunction and rejection. Oral antivitamin K anticoagulants effectively prevent allograft thrombosis in aPL recipients. The debate on the role of aPL in renal transplant is limited by the expression of data as percentage of recipients positive for aPL rather than aPL titres in many studies

    The Dependence of Work Function on Thickness in Epitaxial Cu-Pd Systems

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    Changes in work function have been measured with a Kelvin probe for the initial stages of epitaxial growth of (111) Cu on (111) Pd and (111) Pd on (111) Cu and for CO adsorption on selected bilayers at room temperature. The results of this study show that, at low metal coverages, the overlayers have properties which differ significantly from those of bulk crystals. One of the most interesting observations was that a quarter monolayer of Cu on Pd (111) increases the saturation work function change upon CO adsorption by more than a factor of three as compared to a thick Pd (111) film

    Self-Supervised Learning Across Domains

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    Human adaptability relies crucially on learning and merging knowledge from both supervised and unsupervised tasks: the parents point out few important concepts, but then the children fill in the gaps on their own. This is particularly effective, because supervised learning can never be exhaustive and thus learning autonomously allows to discover invariances and regularities that help to generalize. In this paper we propose to apply a similar approach to the problem of object recognition across domains: our model learns the semantic labels in a supervised fashion, and broadens its understanding of the data by learning from self-supervised signals on the same images. This secondary task helps the network to focus on object shapes, learning concepts like spatial orientation and part correlation, while acting as a regularizer for the classification task over multiple visual domains. Extensive experiments confirm our intuition and show that our multi-task method combining supervised and self-supervised knowledge shows competitive results with respect to more complex domain generalization and adaptation solutions. It also proves its potential in the novel and challenging predictive and partial domain adaptation scenarios

    Liver biopsy in type 2 diabetes mellitus: steatohepatitis represents the sole feature of liver damage

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    Recent studies report a prevalence of non-alcoholic fatty liver disease (NAFLD) of between 70% and 80% in patients with metabolic syndrome (MS) and type 2 diabetes mellitus (T2DM). Nevertheless, it is not possible to differentiate between simple steatosis and nonalcoholic steatohepatitis (NASH) with non-invasive tests. The aim of this study was to differentiate between simple steatosis and NASH by liver biopsy in patients with hypertransaminasemia and MS or T2DM. Two hundred and fifteen patients with increased ALT levels and MS, and 136 patients at their first diagnosis of T2DM regardless of ALT values were consecutively admitted to a tertiary hepatology center between January 2004 and November 2014. Exclusion criteria were other causes of liver disease/ALT increase. Each patient underwent a clinical, laboratory and ultrasound evaluation, and a liver biopsy. Gender distribution, age, and body mass index were similar in the two groups of patients, whereas cholesterol levels, glycemia and blood pressure were significantly different between the two groups. The prevalence of NAFLD was 94.82% in MS patients and 100% in T2DM patients. NASH was present in 58.52% of MS patients and 96.82% of T2DM. Consequently, this study reveals that, by using liver biopsy, almost all patients with T2DM or MS have NAFLD, which in patients with T2DM means NASH. Importantly, it suggests that NASH may be one of the early complications of T2DM due to its pathophysiological correlation with insulin resistance
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