1,304 research outputs found
Helicobacter pylori infection, chronic gastritis, and proton pump inhibitors
No full textThe proton pump inhibitors (PPIs) omeprazole, lansoprazole, and pantoprazole are widely used as antisecretory drugs and, in association with antibiotics, for the treatment of Helicobacter pylori infections. PPIs possess antibacterial activity against H. pylori in vitro, and may also exert an anti-inflammatory effect by interfering with the cellular immune response to infection. Their antimicrobial activity is selective for H. pylori. Lansoprazole is the most effective, although its bactericidal activity is similar to that of omeprazole. Pantoprazole is the least effective. The mechanisms that account for the antibacterial effects of PPIs may depend on a structural similarity of PPIs to antibiotics which are active against H. pylori, on the inhibition of bacterial urease exerted by PPIs, or on the possible interaction of PPIs with bacterial ATPases that regulate the transmembrane ion flux. Recent studies have shown that PPIs have anti-inflammatory actions and can interfere with the host-bacteria interactions. Lansoprazole can bind to polymorphonuclear leukocytes that infiltrate the gastric mucosa colonized by H. pylori and can thus inhibit the oxidative burst of activated inflammatory cells. In an in vivo study, lansoprazole reduced the degree of activity of histologic gastritis independently of the presence of H. pylori. In another study, omeprazole was capable of inhibiting the cytotoxic activity of NK T cells. Investigation of PPI interactions with H. pylori activities and the cellular immune response to the infection may help us to understand the pathogenic mechanisms of H. pylori-associated diseases and enable clinicians to better treat the
Leonardo Ricci 100. Scrittura, pittura e architettura: 100 note a margine dell’Anonimo del XX secolo
No full textLeonardo Ricci 100. Scrittura, pittura architettura. 100 note a margine dell’Anonimo del XX secolo
No full textIl catalogo raccoglie saggi di Claudia Conforti, Antonella Greco, Aldo Colonnetti, Giovanni Leoni, Giovanna Uzzani, Luca Barontini, Giovanni Bartolozzi, Paola Ricci, Stefano Lambardi e Ilaria Cattabriga, oltre ai saggi degli stessi curatori. Nel volume sono pubblicati i molti documenti inediti, schizzi, disegni, quadri e fotografie, esposti nella mostra al Refettorio di Santa Maria Novella, organizzati secondo un ritmo scandito dalle parole del libro-diario di Ricci, l’Anonimo del XX secolo
Black-Box Model-Based Active Damping of Driveline Oscillations
No full textThis paper presents a driveline active damping strategy for electric vehicles. We first propose a black-box identification of the main oscillation modes of a transmission of a 4 Wheel Driven electric vehicle. We identify the models in a variety of conditions. We then design the active damping control using mathcal H_infty considerations on the identified models. Extensive experimental validation shows that the active damping reduces of 24% the longitudinal jerk during sharp acceleration maneuvers without negatively affecting the longitudinal acceleration. Furthermore, we test the controller under a variety of condition to assess its robustness with respect to transmission load variations, friction changes and velocity
On optimal control of multichamber suspensions
No full textThis paper deals with the technological analysis, and optimal control of multichamber suspensions for automotive applications. Multichamber suspensions are composed by a variable damping shock absorber and an air-spring equipped with at least an auxiliary volume. The auxiliary volume is connected to the air-spring main chamber through a two-state valve. This configuration allows for a rapid change of both the damping and the stiffness of the suspension. The first goal of this paper is to model and analyze the behaviour of the suspension, the second goal is to investigate the potential benefit of this architecture from the comfort point of view. To this aim, the paper proposes an optimal benchmark controller and tests it in simulation showing comfort improvements up to 16% with respect to state-of-the-art solution of a passive soft spring and semi-active damping control
Optimizing Thermal Energy Sharing in Smart District Heating Networks
No full textThe constant attention to sustainability aimed at reconciling economic and social development with environmental protection is the driving force of the continuous growth of renewable energy in the energy sector. Among the numerous actions taken by the European Commission (EC) in this direction, an important initiative towards the complete decarbonization is represented by the Renewable Energy Communities (RECs). According to the EC, "energy communities enable collective and citizen-driven energy actions to support the clean energy transition. They can contribute to increasing public acceptance of renewable energy projects and make it easier to attract private investments in the clean energy transition". At the European level, numerous energy communities are emerging, although they are all based on photovoltaic production and, consequently, focus only on electricity flows. The aim of this paper is to define a thermal energy community in which thermal energy sharing can be achieved by exploiting the concept of the smart district heating network. Starting from a small existing district heating network, its conversion into a smart one will be analyzed and optimized with the aim of studying the sharing of thermal energy between the various prosumer and non-prosumer users connected to the district heating network
sj-docx-1-pim-10.1177_14750902231173470 – Supplemental material for LCA approach for environmental impact assessment within the maritime industry: Re-design case study of yacht’s superstructure
No full textSupplemental material, sj-docx-1-pim-10.1177_14750902231173470 for LCA approach for environmental impact assessment within the maritime industry: Re-design case study of yacht’s superstructure by Francesco Del Pero, Caterina Antonia Dattilo, Alessandro Giraldi and Massimo Delogu in Proceedings of the Institution of Mechanical Engineers, Part M: Journal of Engineering for the Maritime Environment</p
Penetration of solar radiation into waters of Messina Strait (Italy)
No full textThe optical properties of the waters of five different stations, three located in the Messina Strait and two near the Strait (open sea), were analysed. Direct spectral measurements of the downward solar irradiance (290 - 800 nm) at different depths (0.5 m, 7 m, 10 m, 13 m, 20 m) were made using a cosine sensor connected to a spectroradiometer. Water samples were collected in the surface layer and their absorption spectra were analysed. The natural fluorescence profiles, along the water column, were determined using a fluorometer (SBE 911 plus - Sea Teach). The spectral attenuation coefficient (K-lambda), the variation of K-lambda in different wavelength ranges (Delta K-Delta lambda), the wavelength corresponding to minimum value of K-lambda, the spectral depths of penetration of both 1% and 10% of the sub-surface irradiance values (P-lambda), the depths of 1% of penetration of UVB, UVA and PAR, the depth ranges of the maxim concentration of Chl a and superficial CDOM were measured at each station. The maximum solar UVB penetration was about 65% of the photic zone and the maximum UVA penetration was nearly 100% (data of the Ionic sea station). Thus, a large part of the photic zone was exposed to UV radiation sufficient to cause a possible reduction in the photosynthetic activity of phytoplankton. The spectral penetration of solar radiation, especially UVB radiation, was significantly different in the three stations of the Strait with respect to the two stations studied in the open sea. This shows that variations in the spectral attenuation along the water column can be used as an indicator of properties of the water body
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