1,721,058 research outputs found
Thermo-responsive polymers: Applications of smart materials in drug delivery and tissue engineering
No full textSynthetic polymers are attracting great attention in the last decades for their use in the biomedical field as nanovectors for controlled drug delivery, hydrogels and scaffolds enabling cell growth. Among them, polymers able to respond to environmental stimuli have been recently under growing consideration to impart a “smart” behavior to the final product, which is highly desirable to provide it with a specific dynamic and an advanced function. In particular, thermo-responsive polymers, materials able to undergo a discontinuous phase transition or morphological change in response to a temperature variation, are among the most studied. The development of the so-called controlled radical polymerization techniques has paved the way to a high degree of engineering for the polymer architecture and properties, which in turn brought to a plethora of sophisticated behaviors for these polymers by simply switching the external temperature. These can be exploited in many different fields, from separation to advanced optics and biosensors. The aim of this review is to critically discuss the latest advances in the development of thermo-responsive materials for biomedical applications, including a highly controlled drug delivery, mediation of cell growth and bioseparation. The focus is on the structural and design aspects that are required to exploit such materials for cutting-edge applications in the biomedical field
Evoluzione tecnologica nelle lubrorifrerigerazione e riduzione dei possibili effetti sulla salute degli esposti
No full textIntermolecular interactions in Poly(2,6-dimethyl-1,4-Phenylenoxide) /(Poly(Styrene) blends from the study of FT-IR spectra at various temperatures
No full textRecoverable Thermo-Responsive Polymeric Surfactants for the Synthesis of Bulk Plastics from Latexes
Full text linkFree-radical emulsion polymerization (eFRP) is widely adopted in industries due to the great advantages that this technique offers in terms of a high polymerization rate, good heat management, and conduction in a non-toxic solvent like water. On the other hand, eFRP requires surfactants to stabilize the produced polymer nanoparticles (NPs). At the same time, the recovery of a bulk material from a NP suspension needs the addition of salts or alkali for the destabilization of the emulsion and the precipitation of the polymer. These can contaminate the final product and affect its properties. For this reason, alternative strategies able to coagulate the NP latex avoiding the addition of exogenous compounds are needed. In this work, we synthesized thermo-responsive polymeric surfactants that are able to promote the NP formation during the eFRP and to allow the recovery of the bulk polymer by simply increasing the environment temperature. Surfactants with a tunable hydrophilic–lipophilic balance were produced through reversible-addition fragmentation chain transfer (RAFT) emulsion polymerization by chain-extending a polyethylene glycol-based macromolecular chain transfer agent with butyl methacrylate, in order to obtain a series of block copolymers with high blocking efficiency, controlled molecular weight distribution, and well-defined thermo-responsive behavior. Then, the RAFT agent was removed to avoid the further extension of the block copolymers, and the surfactants were tested in the eFRP of different monomers (i.e., butyl methacrylate, methyl methacrylate, and styrene) to produce stable NP latexes. Finally, the possibility of triggering the NP aggregation and of guaranteeing the recovery of both surfactants and bulk material by simply changing the temperature of the system was assessed
Indagini archeologiche all’interno della Rocca di Urbisaglia: dalla città romana a quella medievale
No full textIl contributo sintetizza l'esito dei lavori di scvao condotto nella Rocca della città medievaledi Urbisagli
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Tifernum Mataurense (Sant'Angelo in Vado - PU) in età tardoantica e post-antica
No full textCon questo studio si è tentato di gettare nuova luce su un periodo ancora rimasto relativamente oscuro tra tardo-antico e alto Medioevo nell’area appenninica Nord-marchigiana, segnatamente alto-mataurense, tenuto conto dei nuovi dati di scavo, raccolti nell’ultimo sessennio dall’Università di Macerata a Tifernum Mataurense (Sant’Angelo in Vado-PU). I dati acquisiti insieme a fonti letterarie ed epigrafiche consentono di ipotizzare un graduale impoverimento già a partire dal II-III sec. d.C. fino ad un tracollo tra la fine del VI ed il VII sec. d.C. All’interno è una successione di fasi di progressiva decadenza, di cui la più grave nel VI sec. è attribuibile a fattori politico-militari (conflitto greco-gotico e calata dei Longobardi) e a non trascurabili concause climatico-ambientali. Alla stregua di altri centri appenninici Nord-marchigiani il centro perde gradatamente prerogative ed organizzazione urbane, benché posizione strategica e risorse paiono consentire forme successive di resilienza e aggregazione areale, sopravvissute poi nelle più tarde istituzioni plebane
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