Numerical Simulation and Experimental Characterization of Emitter Wrap through Solar Cells with Deep Grooved Base Contact (EWT-DGB)

Abstract In this work we present an Emitter Wrap Through cell with Deep Grooved Base contact (EWT-DGB), designed for both 1-sun and concentrating applications. The proposed approach, which consists in a deep grooved hole array composed by holes of two alternating doping type, allows both a reduction of the cell series resistance and an increase in collection efficiency also by using relatively thick substrates with low lifetime. The measured experimental data including dark J-V characteristics, figures of merit (FOMs) under illumination and external quantum efficiency (EQE) are compared to the results of 3-D drift-diffusion TCAD numerical simulations. Moreover, the impact of the hole spacing and of process-dependent physical parameters (interface defects) on FOMs is investigated by means of simulations

Patient referral is influenced by dialysis centre structure in the Diamant Alpin Dialysis cohort study

Background. Late referral (LR) to the nephrologist of patients with progressing chronic kidney disease (CKD) has numerous deleterious effects and is observed in many countries. The contributing factors associated with LR are controversial and poorly defined. We hypothesized that these factors might be better identified by analysing patients starting dialysis in three distinct European countries within the same area. Method. The referral and progression of kidney failure patterns were analysed with demographic, clinical and biological data in 279 non-selected consecutive patients starting dialysis in eight centres of three adjacent regions in France, Italy and Switzerland. Results. Early referral (>6 months before the start of dialysis) was seen in 200 patients (71.6%), intermediate referral (1-6 months) in 42 (15.1%) and LR (<1 month) in 37 (13.3%). However inter-centre variations were between 2 and 19% for LR and 6-50% for combined late and intermediate referral. There were no differences at the national levels, but LR was more frequent in the large city centres than in the private or regional structures, with 31 out of 169 (18.3%), two out of 55 (5.4%) and four out of 55 (7.3%), respectively, of their patients (P<0.01). By multivariate analysis, it appears that, besides the presence of an active cancer and the CKD progression rate, the centre structure and the referring physician (primary care physicians and nephrologists are less responsible for LR than other medical specialists) play a significant role in the practice of LR. Conclusions. Within a dialysis cohort spread over adjacent regions of three countries, LR has the same global distribution pattern, indicating that different health and social security systems do not play a major role in inducing or preventing this practice. The contributing factors for LR that were identified are the type of the referring physician and the structure of the dialysis unit. Both factors are potential targets for an educational and collaborative approac

A Systematic Review and International Web-Based Survey of Randomized Controlled Trials in the Perioperative and Critical Care Setting: Interventions Reducing Mortality

The authors aimed to identify interventions documented by randomized controlled trials (RCTs) that reduce mortality in adult critically ill and perioperative patients, followed by a survey of clinicians’ opinions and routine practices to understand the clinicians’ response to such evidence. The authors performed a comprehensive literature review to identify all topics reported to reduce mortality in perioperative and critical care settings according to at least 2 RCTs or to a multicenter RCT or to a single-center RCT plus guidelines. The authors generated position statements that were voted on online by physicians worldwide for agreement, use, and willingness to include in international guidelines. From 262 RCT manuscripts reporting mortality differences in the perioperative and critically ill settings, the authors selected 27 drugs, techniques, and strategies (66 RCTs, most frequently published by the New England Journal of Medicine [13 papers], Lancet [7], and Journal of the American Medical Association [5]) with an agreement ≥67% from over 250 physicians (46 countries). Noninvasive ventilation was the intervention supported by the largest number of RCTs (n = 13). The concordance between agreement and use (a positive answer both to “do you agree” and “do you use”) showed differences between Western and other countries and between anesthesiologists and intensive care unit physicians. The authors identified 27 clinical interventions with randomized evidence of survival benefit and strong clinician support in support of their potential life-saving properties in perioperative and critically ill patients with noninvasive ventilation having the highest level of support. However, clinician views appear affected by specialty and geographical location

DECLINE OF PREVALENCE OF RESISTANCE ASSOCIATED SUBSTITUTIONS TO NS3 AND NS5A INHIBITORS AT DAA- FAILURE IN HEPATITIS C VIRUS IN ITALY OVER THE YEARS 2015 TO 2018

Background: A minority of patients fails to eliminate HCV and resistance-associated substitutions (RASs) are commonly detected at failure of interferon-free DAA regimens . Methods: Within the Italian network VIRONET-C, the prevalence of NS3/NS5A/NS5B RASs was retrospectively evaluated in patients who failed an EASL recommended DAA-regimen in 2015-2018 . The geno2pheno system and Sorbo MC et al. Drug Resistance Updates 2018 were used to infer HCV- genotype/subtype and predict drug resistance . The changes in prevalence of RASs over time were evaluated by chi-square test for trend, predictors of RASs at failure were analysed by logistic regression . Results: We included 386 HCV infected patients: 75% males, median age was 56 years (IQR 52-61), metavir fibrosis stage F4 in 76%; 106 (28%) were treatment- experienced: 91 (86%) with IFN-based treatments, 26 (25%) with DAAs. Patients with HIV and HBV coinfection were 10% (33/317) and 8% (6/72), respectively. HCV genotype was 1b in 122 pts (32%), 3 in 109 (28%), 1a in 97 (25%), 4 in 37 (10%), 2 in 21 (5%). DAA regimens were: LDV/SOF in 115 (30%), DCV/SOF in 103 (27%), 3D in 83 (21%), EBR/GRZ in 32 (8%), VEL/SOF in 29 (7%), GLE/PIB in 18 (5%) and 2D in 6 (2%); ribavirin was administered in 123 (32%) . The NS5A fasta-sequence was available for all patients, NS5B for 361 (94%), NS3 for 365 (95%) . According to the DAA failed the prevalence of any RASs was 90%, namely 80/135 (59%) in NS3, 313/359 (87%) in NS5A, 114/286 (40%) in NS5B . The prevalence of any RASs significantly declined from 2015 to 2018 (93% vs 70%, p=0.004): NS5A RASs from 90% to 72% (p=0 .29), NS3 RASs from 74% to 18% (p&lt;0 .001), while NS5B RASs remained stable . Independent predictors of any RASs included advanced fibrosis (AOR 6.1, CI 95% 1.8-20.3, p=0 .004) and genotype (G2 vs G1a AOR 0 .03, CI 95% 0 .002- 0 .31, p=0 .004; G3 vs G1a AOR 0 .08, CI 95% 0 .01-0 .62, p=0 .02; G4 vs G1a AOR 0 .05, CI 95% 0 .006-0 .46, p=0 .008), after adjusting for age, previous HCV treatment and year of genotype . Notably, full activity was predicted for GLE/PIB in 75% of cases and for at least two components of VEL/SOF/VOX in 53% of cases, no case with full-resistance to either regimen was found . Conclusion: Despite decreasing prevalence over the years, RASs remain common at virological failure of DAA treatment, particularly in patients with the highest grade of liver fibrosis. The identification of RASs after failure could play a crucial role in optimizing retreatment strategies

Numerical Conservation Issues for Stochastic Hamiltonian Problems

We focus on the study of stochastic Hamiltonian problem driven by additive noise. Stochastic Runge-Kutta methods obtained as stochastic perturbation of symplectic Runge-Kutta methods exhibit a remarkable error growth as the parameter ε of the diffusive part increases. Through a perturbative theory, we investigate the reason of this behaviour, due to the presence of a secular term ε √t destroying the overall conservation accuracy

An exponentially fitted quadrature rule over unbounded intervals

A new class of quadrature formulae for the computation of integrals over unbounded intervals with oscillating integrand is illustrated. Such formulae are a generalization of the gaussian quadrature formulae by exploiting the Exponential Fitting theory. The coefficients depend on the frequency of oscillation, in order to improve the accuracy of the solution. The construction of the methods with 1, 2 and 3 nodes is described, together with the comparison of the order of accuracy with respect to classical formulae

On the perturbative analysis of the time-discretization for stochastic Hamiltonian problems

Stochastic Differential Equations (SDEs) are excellent models used to describe several natu-ral and real-life phenomena, when they are subject to random perturbations. This is the case, for example, of weather forecasts, turbulent diffusion or investment finance. Indeed, SDEs provide a key tool for a "mesoscopic" approach to describe the effects of external environments to a physical model. The irreversible character of a stochastic dynamics destroys the idea of isolate systems, since the particles are repeatedly influenced by small unpredictable perturbations of the external environment. In this talk, specifically, we focus on the study on the dynamics of stochastic Hamiltonian problems because they represent a suitable candidate to conciliate the canonical character of the evolution equations, with the non-differentiability of the Wiener process, that describes the continuous innovative character of stochastic diffusion. Our analysis focuses on the study of stochastic Runge-Kutta methods developed by Burrage and Burrage, obtained through a stochastic perturbation of symplectic Runge-Kutta methods, in order to understand if they maintain the linear drift visible in the expected Hamiltonian of the system. In particular we observe that stochastic Runge-Kutta methods exhibit a remarkable error that increases with the parameter ε, describing the amplitude of the diffusive part of the problem. Through a perturbative analysis, in terms of ε expansions, we investigate the reason of this behaviour and exhibit the presence of a secular term ε*sqrt(t) that destroys the overall conservation accuracy. The theoretical results are also confirmed by selected numerical experiments