1,721,036 research outputs found
Anti-oxidant grafted PLGA nanomaterials for neointimal hyperplasia prevention: a feasibility study
No full textThe restenosis after percutaneous transluminal angioplasty (PTA) mainly involves the uncontrolled proliferation of smooth muscle cells (SMC) in blood vessel’s tunica media. The local delivery of hyperplasia inhibiting drugs could allow to reduce its occurrence. One of the possible approaches can consist in the release of drug loaded polymeric nanoparticles (NP) during the expansion of the balloon. This preliminary work aims to evaluate the feasibility of NP made of anti-oxidant grafted PLGAs (g- AA-PLGA) as potential novel drug carrier for restenosis prevention.
Caffeic acid (CA) and resveratrol (RV) were grafted to PLGA (L/G ratio 50/50, Mw=20.4 KDa, Tg=47.1±0.5 °C) by a radical process [1, 2]. The materials were characterized by DSC, GPC and DPPH assay. NP were prepared by the solvent displacement method and characterized for hydrodynamic diameter (DH) and zeta potential () by DLS. NP cytotoxicity was evaluated by MTT assay. Cellular uptake and subsequent exocytosis was studied in macrophages, SMC and endothelial cells.
The grafting procedure permitted to obtain polymers with good radical scavenging properties (DPPH inhibition at 1h of 90.0±0.4% for g-CA-PLGA and 27.0±0.8% for g-RV-PLGA) without a significant variation in Mw. Monodispersed NP with a DH lower than 200 nm and a of about -30 mV were prepared for all the polymers. MTT assays evidenced no signs of cytotoxicity in all the cellular models. In macrophages, no statistically differences were found among the uptake of all the types of NP. In endothelial cells, the uptake of g-CA-PLGA NP was significantly higher than the one of g-RV-PLGA and PLGA NP (two-way ANOVA: g-CA-PLGA vs PLGA p=0.028 and g-CA-PLGA vs g-RV-PLGA p=0.032). Moreover, g-RV-PLGA and PLGA NP were similarly taken up (p>0.05). In SMC, the uptake of g-CA-PLGA NP occurred faster compared to the other NP (one-way ANOVA: g-CA-PLGA vs PLGA p=0.002; g-CA-PLGA vs g-RV-PLGA p=0.004 and g-RV-PLGA vs PLGA p=0.984). The exocytosis of g-CA-PLGA NP occurred within 8 h and 48 h in macrophages and SMC, respectively. These data agreed with images obtained by fluorescence microscopy. The results on cellular uptake and exocytosis demonstrate that g-CA-PLGA NP may be a suitable carrier to locally administer drugs, in the prevention of restenosis following PTA.
References
[1] Cilurzo F, Puoci F, Selmin F, Iemma F, Minghetti P. Pyrogallic acid-PLGA conjugate as new biodegradable material suitable for final sterilization by irradiation. Polym. Adv. Technol., 22, 2201- 2205, 2011.
[2] Selmin F, Puoci F, Parisi O.I, Franzè S, Musazzi U.M, Cilurzo F. Caffeic acid-PLGA conjugate to design drug delivery systems stable to sterilization. J. Funct. Biomater., 6, 1-13, 2015
Healthy Eating Apps. La salubrità degli alimenti in mano agli algoritmi
No full textThe essay takes its basis from the information and labelling duties, laid down by the European legislator for food products, in order to analyse the use of the apps aimed to help the consumer in the choice of foods that best meet his or her needs. Although Healthy Eating Apps can be a valuable aid in the interpretation of the information on the label, their use raises several legal issues related mainly to the control of safety in the functioning of the algorithm and software, as well as the processing of personal data that consumers can enter in the app
Mercato digitale e nuovi paradigmi della tutela del consumatore in Brasile e Germania
No full textThe paper analyses the growth of the digital market and focuses on two topics: consumer protection in the digital market and liability of the internet service provider. These two topics are considered in the light of the Brazilian and the German experience; the combined analysis between these two legal sys- tems demonstrates the existence of common principles and striking similarities. The paper shows that both legal systems seem to extend consumer protection to the weaker party who is acting in the digital market and not only to the natural person who is acting outside the scope of an economic activity. The paper further argues that consumer protection in the digital market can be eas- ier to understand if we take into account hybrid economic operators like the prosumer, which are discussed in detail. Finally, the paper examines the simi- larities between Brazil and Germany regarding how jurisprudence as well as statutory law seek to protect digital rights. In both countries courts started to protect digital rights of their citizens by considering them to be fundamental rights. Only in Brazil, however, has the legislature taken the extra step of en- shrining and specifically defining these rights by statute
Efficienza energetica dei sistemi ibridi per il riscaldamento ambienti. Rivista INGENIO
No full textRIVISTA INGENI
SMA actuator for gas combi boiler divertine valve
No full textAbstract
This article deals with a three way diverting valve for heating boilers using a shape memory alloy material to move its actuator. This project was realized by the Research & Development Department of MTS (Merloni Termosanitari) together with the Energy Department of the University of Ancona; this device is protected by a European patent. As is well known, the three way diverting valve inside a heating boiler has the function to shift hot water flow coming from the primary heat exchanger either towards the sanitary circuit or the domestic heating system, depending on the demand. The idea of a shape memory alloy to realize the actuator movement of the three way valve represents a good alternative to traditional actuator moving systems using a electric motor. A shape memory alloy is characterised by the ability to recover a pre-macroscopic deformation during a phase change caused by heating; moreover the deformation recovery brings to a increase to the mechanical properties of a shape memory alloy. In this article, we will present in detail the valve functionality, the equations we used for the dimensioning, and the description of the most important tests on the device to verify its efficacy and reliabililty
L’action dans le texte. Pour une approche herméneutique du Trattato teorico-prattico di Ballo (1779) de G. Magri (CN D, Pantin, 2018).
No full textArianna Béatrice Fabbricatore, L’action dans le texte. Pour une approche herméneutique du Trattato teorico-prattico di Ballo (1779) de G. Magri. La parole est-elle capable de décrire le mouvement ? Peut-on vraiment comprendre et interpréter un pas de danse à partir de sa description verbale ? Avec l’ambition d’offrir au lecteur un aperçu clair et pratique de la danse de son époque, Gennaro Magri, danseur grotesque napolitain, publie en 1779 le Trattato teorico-prattico di ballo. Dans ce..
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