Agostino Oglialoro Todaro, allievo di Paternò e mentore di Marussia Bakunin

L'attività di ricercatore e di docente di Agostino Oglialoro Todaro è discussa e messa in relazione con il contesto storico nella Napoli di fine ottocento e inizio novecento

Optimization of Digital Overcurrent Protection Settings in DC Urban Light Railway Systems

DC urban light railway systems are used for public transportation in many towns worldwide. In these systems, short circuit currents are often similar, both in steady state magnitude and in rate-of-rise, to normal operation currents. In order to properly set the protection relays, to obtain short circuit discrimination and to avoid nuisance trippings, it is important to analyze short circuit and normal operation current patterns. It is also important to highlight that normal operation current patterns are not only those related to rolling stock acceleration, but also to zone commutation. This paper presents the results of several measurement campaigns, performed for this purpose, on the tram network of Turin, Italy. The measurements results are then used to propose optimized settings for the installed overcurrent protections

Impact of MV Ground Fault Current Distribution on Global Earthing Systems

Global earthing systems (GESs), created by the interconnection of local earthing systems, should guarantee the absence of dangerous touch voltages. One of the reasons for this safety characteristic of GESs is the fault current distribution between grounding electrodes and medium-voltage (MV) cable sheaths: Only a small portion of the fault current is injected into the ground by the ground grid of the faulty substation. In systems with isolated neutral or with resonant earthing, this effect may be sufficient to provide safety from electric shock. In this paper, a model describing the behavior of the MV distribution system with interconnected grounding electrodes during a ground fault is built. It is then used to analyze the impact of different factors on the fault current distribution. A sensitivity analysis is performed, varying the main parameters, and the results are used to draw some conclusions on the current distribution influence on GESs

Effects of Anionic Liposome Delivery of All–Trans–Retinoic Acid on Neuroblastoma Cell Differentiation

All–trans–retinoic acid (ATRA) has long been known to affect cell growth and differentiation. To improve ATRA’s therapeutic efficacy and pharmacodynamics, several delivery systems have been used. In this study, free ATRA and anionic–liposome–encapsulated ATRA were compared for their effects on SK–N–SH human neuroblastoma cell growth and differentiation. Anionic liposomes made of L–α –phosphatidylcholine (PC) and L–α –phosphatidic acid (PA), empty (PC–PA) and loaded with ATRA (PC–PA–ATRA), were characterized by dynamic light scattering (DLS) and electrophoretic mobility measurements, and drug entrapment efficiency (EE%) was measured to evaluate the applicability of the new colloidal formulation. The results of brightfield microscopy and cell growth curves indicated that ATRA, whether free or encapsulated, reduced growth and induced differentiation, resulting in SK–N–SH cells changing from epithelioid to neuronal–like morphologies, and producing a significant increase in neurite growth. To further characterize the neuro-differentiation of SK–N–SH cells, the expression of βIII–Tubulin and synaptophysin and mitochondria localization were analyzed via immunofluorescence. Increased expression of neuronal markers and a peculiar localization of mitochondria in the neuritic extensions were apparent both in ATRA– and PC–PA–ATRA–differentiated cells. As a whole, our results strongly indicate that ATRA treatment, by any means, can induce the differentiation of parent SK–N–SH, and they highlight that its encapsulation in anionic liposomes increases its differentiation ability in terms of the percentage of neurite–bearing cells. Interestingly, our data also suggest an unexpected differentiation capability of anionic liposomes per se. This work highlights the importance of developing and carefully testing novel delivery nanocarriers, which are a necessary first “step” in the development of new therapeutic settings

Global Earthing System: Can Buried Metallic Structures Significantly Modify the Ground Potential Profile?

Global earthing systems (GESs), which are created by the interconnection of local earthing systems, should guarantee the absence of dangerous touch voltages. According to international standards, one of the reasons for this safety characteristic of GESs is that medium-voltage and low-voltage grounding systems form a quasi-equipotential area. Typical examples of GESs are in city centers due to the high number of interconnected grounding systems in the area. For this reason, in addition to ground grids, other metallic parts with different primary functions shall be also considered, e.g., water and gas pipes, tramway tracks, and building foundations can modify the electric potential distribution in the area. In this paper, a model based on the Maxwell's subareas method (MaSM) is used to evaluate how buried metallic parts, which are not intentionally connected to ground grids, modify the electric potential on the soil surface. First, the MaSM model is validated with experimental measurements on a simple electrode configuration. The measured voltages are compared with the MaSM results and with the results obtained with a finite-element method model simulated with COMSOL Multiphysics. Then, the simulations are carried out on a realistic urban test case

Update on COVID-19 and Effectiveness of a Vaccination Campaign in a Global Context

The COVID-19 pandemic caused by SARS-CoV-2 remains a significant issue for global health, the economy, and society. When SARS-CoV-2 began to spread, the most recent serious infectious disease of this century around the world, with its high morbidity and mortality rates, it is understandable why such infections have generally been spread in the past, mainly from international travel movements. This perspective review aimed to provide an update for clinicians on the recent developments related to the microbiological perspectives in pandemics, diagnostics, prevention (such as the spread of a virus), vaccination campaigns, treatment options, and health consequences for COVID-19 based on the current literature. In this way, the authors attempt to raise awareness on the transversal nature of these challenges by identifying the main risk/vulnerability factors that the scientific community must face including our current knowledge on the virus capacity of the mechanism of entry into the cells, the current classifications of viral variants, the knowledge of the mathematical model on the spread of viruses (the possible routes of transmission), and the effectiveness of vaccination campaigns in a global context of pandemic, particularly from COVID-19, with a look at new or future vaccines

Acute disseminated encephalomyelitis presenting as fever of unknown origin: case report

BACKGROUND: Fever of unknown origin (FUO) can be defined as a body temperature higher than 38.3°C on several occasions over more than 3 weeks, the diagnosis of which remains uncertain after 1 week of evaluation. Acute disseminated encephalomyelitis (ADEM) is an inflammatory demyelinating disease of the central nervous system with a wide range of clinical manifestations. The highest incidence of ADEM is observed during childhood and it usually occurs following a viral or bacterial infection or, more rarely, following a vaccination, or without a preceding cause. CASE PRESENTATION: Here, we describe an atypical case of ADEM that initially manifested as several weeks of FUO in a fifteen years old boy. CONCLUSIONS: This case report suggests a new possible syndromic association between ADEM and FUO, which should be considered in the clinical examination of patients with FUO, especially in the presence of also modest neurologic or neuropsychiatric symptoms

Acute Disseminated Encephalomyelitis Presenting as Fever of Unknown Origin: Case Report

Background: Fever of unknown origin (FUO) can be defined as a body temperature higher than 38.3°C on several occasions over more than 3 weeks, the diagnosis of which remains uncertain after 1 week of evaluation. Acute disseminated encephalomyelitis (ADEM) is an inflammatory demyelinating disease of the central nervous system (CNS) with a wide range of clinical manifestations. The highest incidence of ADEM is observed during childhood and it usually occurs following a viral or bacterial infection or, more rarely, following a vaccination, or without a preceding cause. Case presentation: Here, we describe an atypical case of ADEM that initially manifested as several weeks of FUO in a 15 years old boy. Conclusions: This case report suggests a new possible syndromic association between ADEM and FUO, which should be considered in the clinical examination of patients with FUO, especially in the presence of also modest neurologic or neuropsychiatric symptoms.&nbsp

Electronic transport, ionic activation energy and trapping phenomena in a polymer-hybrid halide perovskite composite

Abstract The exploitation of methylammonium lead iodide perovskite-polymer composites is a promising strategy for the preparation of photoactive thin layers for solar cells. The preparation of these composites is a simple fabrication method with improved moisture stability when compared to that of pristine perovskite films. To deepen the understanding of the charge transport properties of these films, we investigated charge carrier mobility, traps, and ion migration. For this purpose, we applied a combinatory measurement approach that proves how such composites can still retain an ambipolar charge transport nature and the same mobility values of the related perovskite. Furthermore, thermally stimulated current measurements revealed that the polymer influenced the creation of additional defects during film formation without affecting charge mobility. Finally, impedance spectroscopy measurements suggested the addition of starch may hinder ion migration, which would require larger activation energies to move ions in composite films. These results pave the way for new strategies of polymer-assisted perovskite film development

Use of zeolite-rich rocks and waste materials for the production of structural lightweight concretes

This paper aims at testing the use of mixtures constituted by natural zeolitized products and SiC-bearing industrial wastes (sludge deriving from polishing of porcelain stoneware tiles, hereafter DPM) for the production of lightweight expanded aggregates as constituents of structural and/or thermo-insulating lightweight concretes. Two commercial products have been used as zeolite natural source: Cab70 (Yellow facies of Campanian Ignimbrite) and IZclino (Turkish clinoptilolite-rich epiclastite). Different amounts of a calcareous material (Pozzano limestones - hereafter CP) from the Sorrento peninsula (Naples - Italy) were also added to a Cab70 - DPM mixture. All raw materials were characterized by means of mineralogical (XRPD) and chemical (XRF) analyses. All the products and mixtures were tested from a technological point of view by means of fusibility and firing tests in order to evaluate the expanding properties. It was evidenced that the expansion of the mixture was deeply depending on the occurrence of SiC in the industrial waste. The addition of CP (10 wt.%) to the mixtures accounts for an even increased expansion, though this is accompanied by a worsening of the mechanical features of the material. These results along with literature data allowed to select 3 mixtures (70% Cab70-30% DPM, 70% IZclino-30% DPM, 60% Cab70-30% DPM-10% CP) and each of them was used for the preparation of 5 l of lightweight aggregates afterward employed for the manufacture of lightweight concretes. It was remarked that natural zeolitized materials mixed with DPM (30 wt. %) can provide lightweight aggregates with densities ranging between 0.8 and 1.0 g/cm3 suitable for the preparation of structural lightweight concretes. The addition to the mixture of CP (10 wt.%) produces less dense aggregates (0.6-0.7 g/cm3) potentially useful for the manufacture of thermo insulating lightweight concretes