Acta Orientalia Vilnensia
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La nascita della filosofia in Grecia: Popper e i Presocratici
No full textIl saggio mette in evidenza il senso del "ritorno ai Presocratici" operato da Karl Popper. Il filosofo austro-inglese vede nel momento aurorale della nascita della filosofia in Grecia l'inaugurarsi di quel "razionalismo critico", di quel dialogo razionale, che è poi la cifra caratteristica della civiltà occidentale. Vengono presi in esame i lavori di Popper sul pensiero antico, dando una ricostruzione storico-filosofica del ruolo e del permanere del pensiero greco in un importante filosofo del Novecento
Filoviridae: classificazione, proprietà dei virus, replicazione, caratteristiche delle infezioni
No full textDevelopment of MnOx base catalysts for the PROX process. Theoretical insights and practical application
No full textThe growing demand for sustainable energy carriers has positioned hydrogen at the center of the global energy transition. However, hydrogen produced by conventional hydrocarbon-reforming processes typically contains residual carbon monoxide (CO) hindering its direct use in proton exchange membrane fuel cells (PEM) due to the poisoning of Pt electrodes. Therefore, the abatement of CO represents a crucial purification step in hydrogen processing for PEM applications.
Among the available H2 purification strategies, apart from methanation and membrane separation, the Preferential Oxidation of CO (PROX) has emerged over the past decades as a highly promising alternative, although the development of efficient, selective and low-cost catalysts represents the main scientific and technological challenge for the practical deployment of PEM technology.
Therefore, aiming at bringing contribution in the field of H2 purification processes, this study offers a comprehensive investigation of the H2 and CO oxidation functionalities of a nanocomposite MnCeOx catalyst by a combined computational and experimental approach documenting its potential PROX behavior for PEM technology exploitation.
The catalyst, synthesized by the redox-precipitation route, was extensively characterized, revealing the dominant role of surface Mn(IV) sites in governing a distinctive PROX behavior in the range of 293-423 K. In fact, catalytic tests reveal that this depends on the high CO oxidation activity of the MnCeOx catalyst at low temperature (∼293 K) and a substantial inactivity towards hydrogen oxidation at T<373 K.
Complementary Density Functional Theory (DFT) calculations performed on a model Mn4O8 cluster provided theoretical support for the experimental observations, revealing different interaction pathways of Mn(IV) sites with CO and H2. These give rise to two separate oxidation cycles, characterized by a significant activation energy gap, which explains the observed selectivity toward CO oxidation.
The experimental and theoretical insights were integrated into two simplified reaction mechanisms involving direct lattice oxygen abstraction and diatomic oxygen species respectively. The validity of these mechanistic interpretations was confirmed through the development of two kinetic models able to predict the CO and H2 oxidation activity of the MnCeOx catalyst in the range of 293-533K.
Overall, this work contributes to the fundamental understanding of MnCeOx catalysts, elucidating the interplay between surface redox chemistry, oxygen mobility and catalytic selectivity.
Beyond elucidating the molecular basis of PROX activity, the integration of computational and experimental insights establishes a robust methodological framework for the rational design of next-generation mixed-oxide catalysts for energy and environmental applications.
Chapter 1 provides an overview of the global energy context highlighting the role of hydrogen as a sustainable energy carrier. It addresses the main hydrogen production routes, including Steam Methane Reforming (SMR), Partial Oxidation (POX) and Autothermal Reforming (ATR) of hydrocarbons and outlines the key purification strategies, namely Pressure Swing Adsorption (PSA), membrane separation and methanation required to meet hydrogen purity standards for hydrogen application. The chapter concludes with a review of recent advances in the preferential oxidation of CO describing the main classes of catalysts, their reaction mechanisms and the technological limitations that motivate further research.
Chapter 2 focuses on materials and methods employed in this study. It describes the preparation of the MnCeOx catalyst and the suite of physico-chemical characterization techniques used to assess its properties, including X-Ray Fluorescence (XRF), X-Ray Diffraction (XRD), N2 physisorption, Laser Raman Spectroscopy (LRS), X-ray Photoelectron Spectroscopy (XPS), Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM), Temperature Programmed Reduction (TPR) and Temperature Programmed Desorption (TPD). The chapter also outlines the catalyst testing protocols, such as Temperature Programmed Catalytic Reaction (TPCR) experiments, and describes the computational approach adopted for Density Functional Theory (DFT) analysis.
Chapter 3, devoted to results and discussion, begins with a detailed interpretation of the main physicochemical characterization data, providing a detailed interpretation of the structural, surface properties and redox behavior of the catalyst. Then, the second part of the chapter highlights the PROX performance of the catalyst under various conditions, in terms of activity, selectivity and stability under both kinetic regime and under real process conditions. Mechanistic insights from Density Functional Theory (DFT) calculations on a model Mn4O8 cluster and kinetic data of CO and H2 oxidation are then used to obtain simplified reaction mechanisms. Based on these evidences, finally, the chapter describes the development of suitable macrokinetic models able to predict the CO and H2 oxidation functionality of MnO2-based catalysts under a wide range of conditions, establishing quantitative correlations between structure, mechanism and reactivity and offering a rational basis for the interpretation and optimization of PROX performance
Post-marketing safety profile of dengue vaccines CYD-TDV and TAK-003: analysis of adverse event reports from a European database
No full textIntroduction: Dengue is one of the major global public health burden, particularly in endemic regions. CYD-TDV and TAK-003 are the currently licensed live attenuated tetravalent dengue vaccines, differing in serostatus indication, age range, and immunogenic design. While efficacy has been demonstrated in clinical trials, post-marketing safety data are still limited, supporting the need for real-world pharmacovigilance analyses. Objective: This study characterize adverse reactions associated with CYD-TDV and TAK-003 reported in the European pharmacovigilance database and to compare their post-marketing safety profiles. Methods: A retrospective pharmacovigilance study was conducted using the EudraVigilance database. Individual Case Safety Reports (ICSRs) listing CYD-TDV or TAK-003 as suspected products were retrieved. Adverse drug reactions were coded using MedDRA® version 28.1 and classified by seriousness and outcome. Disproportionality analyses were performed using Reporting Odds Ratios (RORs) with 95% confidence intervals at the System Organ Class (SOCs) and Preferred Terms (PTs) levels. Sensitivity analyses included grouping clinically related PTs and restricting analyses to serious cases. Vaccine groups were compared using chi-square tests. Results: A total of 2,288 ICSRs were identified, including 1,768 (77.3%) related to TAK-003 and 520 (22.7%) to CYD-TDV. TAK-003-related reports mainly involved adults (49.8%) and females (57.9%). Although most ICSRs were classified as serious, serious reports were more frequent for CYD-TDV than for TAK-003 (81.1% vs. 76.4%; p = 0.04). Fatal outcomes were also more commonly reported for CYD-TDV (50.8% vs. 0.6%; p < 0.01). At the SOC level, TAK-003 showed lower disproportional reporting than CYD-TDV for infections and infestations (ROR = 0.07; 95% CI = 0.056–0.089), gastrointestinal disorders (ROR = 0.22; 95%CI = 0.18–0.27), general disorders and administration site conditions (ROR = 0.29; 95%CI = 0.23–0.36), nervous system disorders (ROR = 0.42; 95%CI = 0.34–0.51), cardiac disorders (ROR = 0.35; 95%CI = 0.23–0.51), and hepatobiliary disorders (ROR = 0.09; 95%CI = 0.04–0.19). Higher reporting for TAK-003 was observed for skin and subcutaneous tissue disorders (ROR = 1.98; 95%CI = 1.59–2.48). Conclusion: This real-world pharmacovigilance study suggests that TAK-003 is predominantly associated with non-serious, reactogenic adverse reactions, whereas CYD-TDV reports more frequently involve serious outcomes, likely reflecting differences in indications and epidemiological contexts. Continued post-marketing surveillance remains essential for both vaccines
Some classes of one-dimensional rings characterized by their reflexive ideals
No full textWe study reflexive ideals in one-dimensional Cohen-Macaulay local rings, providing characterizations of almost Gorenstein rings, rings with minimal multiplicity, and Arf rings, which describe their reflexive fractional ideals
A Quantitative Method for 3D Scan Quality Assessment Under Different Surface Conditions for Reverse Engineering of Shipyard Components
No full textShipyards are transitioning toward Industry 4.0 more slowly than other industrial sectors, and this inertia often limits the adoption of reliable digital workflows for reverse engineering. Within the wider research aimed at supporting the digital transition of shipbuilding operations, this study presents a dedicated methodology for evaluating 3D scan quality by combining three complementary indicators describing geometric completeness, agreement with a reference model, and measurement accuracy and variability. A purpose-designed test sample representative of shipbuilding geometrical challenges was manufactured in metal by CNC methods and in PLA through additive manufacturing. Two scanning systems, a field-oriented portable device and a metrology-oriented fixed system, were evaluated
under raw surface conditions and with tracking enhancement strategies (optical markers and scanning spray). Results show that reflective surfaces represent a critical scenario, where tracking enhancement is essential to obtain continuous reconstruction and reliable
dimensional correspondence. Conversely, with low-reflectivity surfaces, high-quality reconstructions can also be achieved with portable systems, with tracking enhancements mainly improving uniformity and repeatability. Overall, the proposed workflow provides a quantitative basis to support scanner selection, which involves a compromise between portability and achievable metrological performance, for shipyards reverse engineering applications
Positioned and primary positioned -semigroups
No full textLet C be a positive integer cone and k \in C. A C-semigroup S is k-positioned if for every h \in C\S we have that k-h belongs to S. In this work, we focus on this family of semigroups and introduce primary positioned C-semigroups, characterizing a subfamily of them through the perspective of irreducibility. Furthermore, we provide some procedures to compute all such semigroups, describing a family of graphs containing all the primary positioned C-semigroups for a fixed k \in C
Cumulative clinical benefits of biologic treatments in patients with moderate-to-severe psoriasis: an Italian real-life experience – IL PSO (Italian Landscape Psoriasis)
No full textBackground Psoriasis is a chronic inflammatory disease associated with significant long-term cumulative life course impairment. Achieving rapid relief from psoriasis is a crucial aspect of an effective treatment, as it helps patients manage their daily discomfort, including pain, itching, embarrassment and other negative impacts of the disease. Cumulative clinical benefit, measured as the area under the curve (AUC) of Psoriasis Area and Severity Index (PASI) responses and days free of disease, offers a comprehensive assessment of treatment efficacy over time. Objectives To evaluate the cumulative clinical benefits of biologic therapies in patients with moderate-to-severe plaque psoriasis in a real-world Italian multicentre setting. Methods This multicentre retrospective real-life study included patients treated with bimekizumab, brodalumab, guselkumab, ixekizumab, risankizumab, secukinumab, tildrakizumab or ustekinumab at 23 Italian referral centres. Cumulative benefit was assessed by the AUC of PASI 100 (100% improvement from baseline) from week 0 to week 52, and days free of disease (PASI 100). Analyses included subgroup evaluations by biologic-naive status and baseline PASI (≤ 10 vs. > 10). Results Among 1017 patients, bimekizumab showed the highest cumulative clinical benefit, with a mean of 203 days free of disease. It was significantly superior to guselkumab (P < 0.05), secukinumab (P < 0.01), ustekinumab (P < 0.01) and tildrakizumab (P < 0.001). The advantage was consistent across subgroups, with 216 days free of disease in biologic-naive and 184 in biologic-experienced patients. No significant differences were found between bimekizumab and ixekizumab, brodalumab or risankizumab. Conclusions In this multicentre real-life study, bimekizumab showed exploratory evidence of the cumulative clinical benefit of biologics in moderate-to-severe psoriasis. These findings highlight the importance of cumulative endpoints and individualized treatment strategies in daily practice
Drying Very Preterm Infants Before Plastic Wrapping at Birth
No full textImportance: Despite continuous improvements in neonatal resuscitation and stabilization in the last decades, thermal management immediately after birth remains an unresolved issue in preterm infants. Objective: To compare 2 strategies of thermal management (plastic wrapping with or without drying) for preventing heat loss at birth in very preterm infants. Design, Setting, and Participants: This multicenter, unblinded, randomized clinical trial was conducted among very preterm infants (birth weight 37.5 °C) at NICU admission, temperature at 1 hour after NICU admission, intraventricular hemorrhage, respiratory distress syndrome, late-onset sepsis, bronchopulmonary dysplasia, and mortality before hospital discharge. Results: Overall, 354 very preterm infants were randomized (180 [50.8%] female; mean [SD] gestational age, 28.6 [2.5] weeks); all received the allocated intervention and were included in the analysis. Normothermia at NICU admission was achieved in 81 of 177 dried infants (45.8%) and 82 of 177 undried infants (46.3%; risk ratio, 0.99; 95% CI, 0.79-1.24). The mean (SD) neonatal temperature at NICU admission was 36.4 °C (0.8 °C) in dried neonates and 36.5 °C (0.7 °C) in undried neonates (mean difference, -0.1 °C; 95% CI, -0.2 °C to 0.1 °C). In-hospital mortality included 26 of 177 dried neonates (14.7%) and 10 of 177 undried neonates (5.6%) (unadjusted risk ratio, 2.60; 95% CI, 1.29-5.23). The other secondary outcome measures were not different between the 2 arms. Conclusions and Relevance: In this multicenter randomized clinical trial, drying before plastic wrapping provided no benefit to very preterm infants in maintaining normothermia at NICU admission. Most deaths could be expected due to the compromised profile of the neonates, with no pathophysiological explanation related to the trial interventions. Approximately half of the infants were outside the normal thermal range at NICU admission; hence, thermal management remains a challenge requiring further investigations