431 research outputs found

    Anderson transition on the Bethe lattice: an approach with real energies

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    We study the Anderson model on the Bethe lattice by working directly with propagators at real energies EE. We introduce a novel criterion for the localization-delocalization transition based on the stability of the population of the propagators, and show that it is consistent with the one obtained through the study of the imaginary part of the self-energy. We present an accurate numerical estimate of the transition point, as well as a concise proof of the asymptotic formula for the critical disorder on lattices of large connectivity, as given in [P.W. Anderson 1958]. We discuss how the forward approximation used in analytic treatments of localization problems fits into this scenario and how one can interpolate between it and the correct asymptotic analysis.Comment: Close to published versio

    Comparison between the diagnostic accuracy of clinico-pathological and molecular tests for feline infectious peritonitis (FIP)

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    The aim of this study was to compare the diagnostic accuracy for feline infectious peritonitis (FIP) of conventional clinic-pathological tests with that of molecular tests such as routine PCR and PCR followed by the sequencing of the Spike (S) gene. Blood, effusion and tissues specimens were collected from 21 FIP suspected cats. In vivo examination consisted of CBC, serum protein electrophoresis, AGP measurement, cytological and biochemical examination and the evaluation of the ΔTNC on effusions, and of molecular tests such the screening PCR (target: 3’UTR region) and the PCR directed towards the S gene followed by the amplification products sequencing in order to detect the aminoacidic substitution recently considered diagnostic for FIP1. These molecular techniques were applied to tissues collected during necropsy, which also allowed forming an FIP group (13 cats) and a non-FIP group (5 cats) based on histology and immunohistochemistry. The best test on tissues was immunohistochemistry (sens: 92.3%; spec: 100%), while the screening PCR suffered of low specificity (spec: 33.3%) and the S gene sequencing showed low sensitivity (sens: 69.2%).On effusions, the best tests resulted screening PCR and cytology (sens and spec: 100%) in comparison with the ΔTNC measurement (sens: 85.7 %; spec: 100%) and the S gene sequencing (sens: 42.8%; spec: 100%).On blood, the best test resulted AGP measurement (sens: 81.8%; spec: 100%), while serum protein electrophoresis showed a surprisingly low sensitivity (sens: 41.7%). Screening PCR (sens: 55.6%; spec: 100%) and S gene sequencing (sens: 33.3%; spec: 100%) proved again low accuracy.

    Health Literacy, Socioeconomic Status and Vaccination Uptake: A Study on Influenza Vaccination in a Population-Based Sample

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    Background: Health Literacy (HL) has been recently hypothesized to affect the relationship between socio-economic status (SES) and health conditions. However, to date no study has yet assessed the potential contribution of HL in the pathway through which SES affects influenza vaccination status. We aim to examine the relationships among HL, SES factors, and influenza vaccination uptake in Tuscan (Italy) residents belonging to different high-risk groups (HRGs) for influenza. Methods: The study was performed within the Tuscan population sample selected in the Italian Behavioral Risk Factor Surveillance System in 2017–2018. HL was assessed using the Italian version of the 6-items European Health Literacy Survey Questionnaire (HLS-EU-Q6). Mediation analyses were conducted using SES variables as independent variables, influenza vaccination status as dependent variable and HL as mediator variable. Results: A total of 3278 people belonged to HRGs for influenza. In the whole sample, 19.4% of the participants were vaccinated against influenza. Participants who were not employed or had a poor financial status were more likely to be vaccinated against influenza (OR 1.56, 95%CI 1.26–1.94, p < 0.001, and OR 1.21, 95%CI 1.00–1.48, p = 0.047 respectively). HL did not mediate the relationship of any of the independent variables with influenza vaccination status. Conclusions: Some SES determinants resulted to influence influenza vaccination uptake, while HL did not affect the likelihood of influenza vaccination uptake among HRGs. Universal health care systems, as in the case of Italy, offering influenza vaccination free of charge to HRGs help in reducing inequalities and mitigating HL demands

    Obestatin: a new element for mineral metabolism and inflammation in patients on hemodialysis.

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    Background: Obestatin plays a key role in the process of energy balance maintenance with an anorectic effect. The main aim of the study was to evaluate obestatin in uremic patients to determine whether it is correlated with nutritional and inflammatory status. Methods: We studied plasma obestatin in uremic patients (n = 50) undergoing hemodialysis therapy and in healthy subjects. Plasma obestatin was measured using an ELISA kit. Results: Obestatin levels in uremic patients were lower than in healthy subjects (p 23 had lower obestatin levels than those with a BMI Conclusions: Based on the present observational data, obestatin might be implicated in the inflammatory state and the disturbances of calcium/phosphate metabolism of hemodialysis patients. However, further studies are warranted to determine whether this hormone plays a key role in contributing to malnutrition and to the chronic inflammatory process

    Endoscopic retrograde appendicitis therapy versus appendectomy or antibiotics in the modern approach to uncomplicated acute appendicitis: A systematic review and meta-analysis

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    Endoscopic therapy; Appendicitis; AppendectomyTerapia endoscĂłpica; Apendicitis; ApendicectomĂ­aTerĂ pia endoscĂČpica; Apendicitis; ApendicectomiaIntroduction Endoscopic retrograde appendicitis therapy has been proposed as an alternative strategy for treating appendicitis, but debate exists on its role compared with conventional treatment. Methods This systematic review was performed on MEDLINE, Cochrane Central Register of Controlled Trials, and EMBASE. The last search was in April of 2023. The risk ratio with a 95% confidence interval was calculated for dichotomous variables, and the mean difference with a 95% confidence interval for continuous variables. The risk of bias was assessed using the Cochrane Risk of Bias 2.0 tool (randomized controlled trials) and the Risk of Bias in Non-Randomized Studies of Intervention tool (non-randomized controlled trials). Results Six studies met the eligibility criteria. Four studies compared endoscopic retrograde appendicitis therapy (n = 236 patients) and appendectomy (n = 339) and found no differences in technical success during index admission (risk ratio 0.97, 95% confidence interval [0.92,1.02]). Appendectomy showed superior outcomes for recurrence at 1-year follow-up (risk ratio 11.28, 95% confidence interval [2.61,48.73]). Endoscopic retrograde appendicitis therapy required shorter procedural time (mean difference –14.38, 95% confidence interval [–20.17, –8.59]) and length of hospital stay (mean difference –1.19, 95% confidence interval [–2.37, –0.01]), with lower post-intervention abdominal pain (risk ratio 0.21, 95% confidence interval [0.14,0.32]). Two studies compared endoscopic retrograde appendicitis therapy (n = 269) and antibiotic treatment (n = 280). Technical success during admission (risk ratio 1.11, 95% confidence interval [0.91,1.35]) and appendicitis recurrence (risk ratio 1.07, 95% confidence interval [0.08,14.87]) did not differ, but endoscopic retrograde appendicitis therapy decreased the length of hospitalization (mean difference –1.91, 95% confidence interval [–3.18, –0.64]). Conclusion This meta-analysis did not identify significant differences between endoscopic retrograde appendicitis therapy and appendectomy or antibiotics regarding technical success during index admission and treatment efficacy at 1-year follow-up. However, a high risk of imprecision limits these results. The advantages of endoscopic retrograde appendicitis therapy in terms of reduced procedural times and shorter lengths of stay must be balanced against the increased risk of having an appendicitis recurrence at one year

    Side-gate leakage and field emission in all-graphene field effect transistors on SiO2/Si substrate

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    We fabricate planar all-graphene field-effect transistors with self-aligned side-gates at 100 nm from the main graphene conductive channel, using a single lithographic step. We demonstrate side-gating below 1V with conductance modulation of 35% and transconductance up to 0.5 mS/mm at 10 mV drain bias. We measure the planar leakage along the SiO2/vacuum gate dielectric over a wide voltage range, reporting rapidly growing current above 15 V. We unveil the microscopic mechanisms driving the leakage, as Frenkel-Poole transport through SiO2 up to the activation of Fowler-Nordheim tunneling in vacuum, which becomes dominant at high voltages. We report a field-emission current density as high as 1uA/um between graphene flakes. These findings are essential for the miniaturization of atomically thin devices

    A Gut-Ex-Vivo System to Study Gut Inflammation Associated to Inflammatory Bowel Disease (IBD)

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    Inflammatory bowel disease (IBD) is a complex, chronic, and dysregulated inflammatory condition which etiology is still largely unknown. Its prognosis and disease progression are highly variable and unpredictable. IBD comprises several heterogeneous inflammatory conditions ranging from Ulcerative Colitis (UC) to Crohn's Disease (CD). Importantly, a definite, well-established, and effective clinical treatment for these pathologies is still lacking. The urgent need for treatment is further supported by the notion that patients affected by UC or CD are also at risk of developing cancer. Therefore, a deeper understanding of the molecular mechanisms at the basis of IBD development and progression is strictly required to design new and efficient therapeutic regimens. Although the development of animal models has undoubtedly facilitated the study of IBD, such in vivo approaches are often expensive and time-consuming. Here we propose an organ ex vivo culture (Gut-Ex-Vivo system, GEVS) based on colon from Balb/c mice cultivated in a dynamic condition, able to model the biochemical and morphological features of the mouse models exposed to DNBS (5-12 days), in 5 h. Indeed, upon DNBS exposure, we observed a dose-dependent: (i) up-regulation of the stress-related protein transglutaminase 2 (TG2); (ii) increased intestinal permeability associated with deregulated tight junction protein expression; (iii) increased expression of pro-inflammatory cytokines, such as TNFα, IFNÎł, IL1ÎČ, IL6, IL17A, and IL15; (iv) down-regulation of the anti-inflammatory IL10; and (v) induction of Endoplasmic Reticulum stress (ER stress), all markers of IBD. Altogether, these data indicate that the proposed model can be efficiently used to study the pathogenesis of IBD, in a time- and cost-effective manner

    Side-gate leakage and field emission in all-graphene field effect transistors on SiO2/Si substrate

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    We fabricate planar all-graphene field-effect transistors with self-aligned side-gates at 100 nm from the main graphene conductive channel, using a single lithographic step. We demonstrate side-gating below 1V with conductance modulation of 35% and transconductance up to 0.5 mS/mm at 10 mV drain bias. We measure the planar leakage along the SiO2/vacuum gate dielectric over a wide voltage range, reporting rapidly growing current above 15 V. We unveil the microscopic mechanisms driving the leakage, as Frenkel-Poole transport through SiO2 up to the activation of Fowler-Nordheim tunneling in vacuum, which becomes dominant at high voltages. We report a field-emission current density as high as 1uA/um between graphene flakes. These findings are essential for the miniaturization of atomically thin devices.Comment: Research article, 8 pages, 5 figure
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