631 research outputs found

    Commentary on a microfluidic platform to design crosslinked hyaluronic acid nanoparticles (cHANPs) for enhanced MRI

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    Strategies to enhance the relaxometric properties of gadolinium (Gd)-based contrast agents (CAs) for magnetic resonance imaging (MRI), without the chemical modification of chelates, have recently had a strong impact on the diagnostic field. We have taken advantage of the interaction between Gadolinium diethylenetriamine penta-acetic acid (Gd-DTPA) and the hydrogel structure of hyaluronic acid to design cross-linked hyaluronic acid nanoparticles down to 35 nm for use in MRI applications. The proposed bioformulations enable the control of the relaxometric properties of CAs, thus boosting the relaxation rate of T1. Our results led us to identify this approach as an adjustable scenario to design intravascularly injectable hydrogel nanoparticles entrapping Gd-DTPA. This approach overcomes the general drawbacks of clinically approved CAs having poor relaxivity and toxic effects

    A Microfluidic Platform to design crosslinked Hyaluronic Acid Nanoparticles (cHANPs) for enhanced MRI

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    Recent advancements in imaging diagnostics have focused on the use of nanostructures that entrap Magnetic Resonance Imaging (MRI) Contrast Agents (CAs), without the need to chemically modify the clinically approved compounds. Nevertheless, the exploitation of microfluidic platforms for their controlled and continuous production is still missing. Here, a microfluidic platform is used to synthesize crosslinked Hyaluronic Acid NanoParticles (cHANPs) in which a clinically relevant MRI-CAs, gadolinium diethylenetriamine penta-acetic acid (Gd-DTPA), is entrapped. This microfluidic process facilitates a high degree of control over particle synthesis, enabling the production of monodisperse particles as small as 35 nm. Furthermore, the interference of Gd-DTPA during polymer precipitation is overcome by finely tuning process parameters and leveraging the use of hydrophilic-lipophilic balance (HLB) of surfactants and pH conditions. For both production strategies proposed to design Gd-loaded cHANPs, a boosting of the relaxation rate T(1) is observed since a T(1) of 1562 is achieved with a 10 μM of Gd-loaded cHANPs while a similar value is reached with 100 μM of the relevant clinical Gd-DTPA in solution. The advanced microfluidic platform to synthesize intravascularly-injectable and completely biocompatible hydrogel nanoparticles entrapping clinically approved CAs enables the implementation of straightforward and scalable strategies in diagnostics and therapy applications

    Existence of Order-Preserving Functions for Nontotal Fuzzy Preference Relations under Decisiveness

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    Looking at decisiveness as crucial, we discuss the existence of an order-preserving function for the nontotal crisp preference relation naturally associated to a nontotal fuzzy preference relation. We further present conditions for the existence of an upper semicontinuous order-preserving function for a fuzzy binary relation on a crisp topological space

    Multiobjective Optimization, Scalarization, and Maximal Elements of Preorders

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    We characterize the existence of (weak) Pareto optimal solutions to the classical multiobjective optimization problem by referring to the naturally associated preorders and their finite (Richter-Peleg) multiutility representation. The case of a compact design space is appropriately considered by using results concerning the existence of maximal elements of preorders. The possibility of reformulating the multiobjective optimization problem for determining the weak Pareto optimal solutions by means of a scalarization procedure is finally characterized

    Recovery of residual copper from low-content tailings derived from waste electrical cable treatment

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    The current work aims at the recovery of residual copper from electrical cables with low content of copper (less than 5%). The sample originated from the tailings of electrical cables that had been previously subjected to copper recycling treatment. The tailings were successively treated with physical methods (sieving, heavy medium sep- aration in ZnCl2 bath, and counter-current separation) and electrochemical methods (cementation, electrowin- ning). Sieving seems to be more efficient than gravity separation methods, since, for 1.00 mm aperture and sieving time as short as 2 min, the undersize copper grade of the product was 57% in copper (from 4% in the feed), with corresponding copper recovery of 53%. Longer sieving times or larger apertures led to products with higher copper recovery but of lower grade. As regards cementation, preliminary tests were carried out to investigate the effect of pH using high purity CuSO4 \ub7 5H2O instead of dissolving metallic copper. Subsequent tests using the sieving undersize product of the scrap copper wire confirmed the results of the preliminary tests; in addition to pH, this product was also used to investigate the effects of the attacking chemical (H2SO4, HCl, H2O2), sacrificial metal (aluminium, iron scrap), temperature, and surface area on cementation. The results show that cementation of the dissolved copper from scrap wire is efficient at pH = 2.5\u20133.2, with sufficient copper recovery within a few hours. Also, electrowinning tests on the undersize sieving product proved the feasibility to obtain pure copper by electrodeposition onto stainless steel cathode with lead anode, without contamination of the electrolytic solution. In both methods, copper purity degrades when HCl acid is used instead of H2SO4. Espe- cially with the use of H2SO4 in electrowinning, it was observed that lead anode is passivated when the solution is entirely depleted from copper ions. The results of the current work clearly demonstrate the feasibility to obtain pure copper from low-grade electric wire scraps by successively submitting the tailings to sieving and cementation

    Degradation Prediction Model for Friction of Road Pavements with Natural Aggregates and Steel Slags

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    Steel production wastes (steel slags) are used more often in asphalt concrete pavements as a valuable replacement for natural aggregates, which are becoming increasingly rare. In this paper authors investigate the polishing characteristics of aggregates, and in particular of steel slags, used in bituminous road surfacing, are a major factor in determining the resistance to skidding. The main purpose of the study is the identification of a suitable degradation model, based on friction indicators, in the laboratory, as well as the comparison of in-situ pavement skid resistance with the cumulative number of passing vehicles over the years. The model predicts the expected resistance to skidding of the road surface based on the knowledge of the polished stone value (PSV) of the aggregates and the expected trac on the road. In this study, several types of aggregates were compared: steel slag, limestone, limestone and slag mixture, diabase, Criggion stone and basalt. Using a standard PSV test, it was found that the aggregates did not reach the lower value of skid resistance (equilibrium value). The analysis of the British Portable Number (BPN) data versus polishing time allowed to empirically derive a regression model for each investigated aggregate. Hence, it appears possible to define both an investigatory level and threshold level to predict the actual residual life of the pavement from the examination of skid resistance

    A design method for improving assembly and environmental sustainability in packaging solutions: a case study in household appliances

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    By using a functional requirement analysis, through Design for Manufacture and Assembly and Design for Environment principles, this paper aims at showing a new design method to improve the overall assembly features and environmental sustainability of a packaging solution. This method provides to rank functional requirements according to three different design specifications and also to the number of relationships they have with each other. At the same time, a ranked order of importance for the packaging parts has been realised, considering the number of performed functions. The purpose of this method is to support the designers in focusing their attention on the most important packaging parts and, at the same time, giving them a clear idea of which are the most important functional requirements to be satisfied. This study has been focused on domestic household packaging, but the provided method can be extended to any particular packaging solution and its findings are still valid. According to the Design for Environmental perspective, the actual and the new resulting packaging solutions have been then compared through Life Cycle Assessment method. The results have shown the new packaging solution being able to cut down the environmental impacts, on average, of approximately 30%

    Fostering Sustainability @UniTs

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    Promoting sustainability through innovative culture and models is nowadays a top task for universities. Their commitment oriented by the 17 United Nations’ Sustainable Development Goals (UN SDGs) conveys the message that sustainability is not a "luxury" but an essential vehicle through which to pursue and guarantee everyone's rights, inclusion and future.Solving complex problems calls for collaboration among communities; aware of that, Italian universities set up the RUS - Italian University Network for Sustainable Development - which acts as a model to encourage collaboration between universities and cities, to spread social innovation at local level and to provide cultural awareness at national level. The University of Trieste (UniTs) joined the network in 2017. Consistent with its strategy for sustainability, UniTs has implemented measures on the macro-context (to raise public awareness and to support research) as well as on micro-context (to orientate behaviors and habits of its community). In particular, it focused on virtuous projects such as waste management, based both on the constant reduction of waste production and on the optimization of the use of materials and products (i.e. paper, glass, reagents), along with the setting of separate waste collection to reduce disposal and favor recycling. The paper will refer on the present framework and the implementation of new integrated projects, aimed at consolidating a community attentive and aware of sustainability
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