STUDY OF COLLOIDAL INTERACTIONS MEDIATED BY BIOMOLECULAR RECOGNITION AND BY ELECTROKINETIC FLOWS.

This PhD thesis focuses on new types of interparticle interactions in colloidal dispersions. In particular, it considers interactions mediated by two different phenomena - biomolecular recognition and electrokinetic flows. The general purpose of this investigation is twofold: while we investigate new mechanisms providing new forms of colloidal interactions, we also exploit the measured interactions to better describe the phenomena at their origin. Indeed, the observed colloidal interactions enable to detect both biomolecular recognition and electrokinetic flows with sensitivity hardly achievable in other ways. In all cases, interactions have been investigated by optical techniques: static and dynamic light scattering, electric transmitted light intensity and electric birefringence. The first part of the thesis reports a systematic study of colloidal interactions performed on a dispersion of charged spherical latex particles having two peculiar properties: their surface can be functionalized with various surfactant molecules and their refractive index is very close to that of water. We have quantified interparticle interactions through the measurement of the second virial coefficients extracted from static and dynamic light scattering measurements. We have studied particles coated with various surfactants and in presence of various ionic strengths. In particular we have studied particles coated with glyco-lipids, so that the colloids are effectively coated with sugar groups. In agreement with previous literature we have found attractive interaction in carbohydrate-coated colloidal dispersions when calcium ions are present in the solution. The second part of the thesis reports a previously undescribed interaction found when colloidal mixture of large and small colloids charged of the same sign are under the effect of an electric field at low (sub-kHz) frequencies. Measurements of the intensity of the transmitted polarized light as a function of field strength and frequency on rods-spheres mixtures have revealed that the previously observed negative torque acting on the rods at low frequency, is accompanied by a field-induced clearing of the dispersion. Measurements performed on mixtures of large (dilute) and small (semidilute) spherical colloids show that such clearing effect is universal and due to an anisotropic redistribution of the small spheres around the larger ones. O(E2) electro-osmotic flows, greatly enhanced by the presence of the small spheres, can be the responsible mechanism of the phenomena observed in rod-sphere and sphere-sphere binary mixture of charged colloidal particles

Salification Controls the In-Vitro Release of Theophylline

Sustained released formulation is the most used strategy to control the efficacy and the adverse reactions of an API (active pharmaceutical ingredient) with a narrow therapeutic index. In this work, we used a different way to tailor the solubility and diffusion of a drug. Salification of Theophylline with Squaric Acid was carried out to better control the absorption of Theophylline after administration. Salification proved to be a winning strategy decreasing the dissolution of the APIs up to 54% with respect to Theophylline. Most importantly, this was accomplished in the first 10 min of the dissolution process, which are the most important for the API administration. Two polymorphs were identified and fully characterized. Theophylline squarate was discovered as trihydrate (SC-XRD) and as a metastable anhydrous form. Indeed, during the Variable Temperature-XRPD experiment, the trihydrate form turned back into the two starting components after losing the three molecules of water. On the other hand, the synthesis of the trihydrate form was observed when a simple mixing of the two starting components were exposed to a high humidity relative percentage (90% RH)

AUTODETERMINAZIONE E AIUTO AL SUICIDIO

IL VOLUME RACCOGLIE GLI ATTI DEL CONVENGO INTERNAZIONALE SVOLTOSI PRESSO L'UNIVERSITA' DI VERONA NEI GIORNI 5 E 6 APRILE 2019 CHE ALLA LUCE DEL CASO CAPPATO - DJ FABO HA ESAMINATO LE PROBLMATICHE AFFRONTATE DALLA CORTE COSTITUZIONALE NELLA PROSPETTIVA STORICA E COMPARATA DELLA DISCIPLINA PENALE IN MATERIA DI ISTIGAZIONE E AIUTO AL SUICIDIO. PERTANTO VI E' STATO UN CONTRIBUTO DI DIVERSE DISCIPLINE, NON SOLO PENALI MA ANCHE MEDICO-LEGALI, COSTITUZIONALI, CIVILI, ECC., CHE HANNO PORTATO A IMPORTANTI CONVERGENZE SULLA NECESSITA' DI INTERVENTI RIFORMATORI NELL'ORDINAMENTO ITALIANO

Contar la historia a la nación. Dos adaptaciones transculturales de la serie española de televisión Cuéntame cómo pasó: Raccontami y Conta-me como foi

En septiembre de 2001, Televisión Española estrenó Cuéntame cómo pasó, una serie de ficción que narra la vida en España durante los últimos años del franquismo a través de la familia Alcántara. Concebida como un relato histórico de carácter popular y para todos los públicos, su inmediato éxito de audiencia significó la consolidación en prime time de una historia definida dramáticamente por el contexto dictatorial del franquismo y, pese a las especificidades históricas, la venta internacional de su formato. En diciembre de 2006, la RAI —Radio Televisione Italiana— estrenó Raccontami, la versión italiana que, con la familia Ferrucci como protagonista de la ficción, plantea el primer caso de adaptación de la serie española en un entorno sociocultural sin dictadura. En abril de 2007, la RTP — Radio Televisión Portuguesa — estrenó Conta-me como foi, la adaptación portuguesa con los Lopes como representantes de la familia de clase media y como testigos de la última etapa de la dictadura salazarista. Emitidas por televisiones públicas, ambas series, además de tener la nostalgia del pasado como punto de partida creativo común, utilizan una estructura narrativa similar a Cuéntame cómo pasó para ofrecer un relato propio y diferenciado de la realidad de sus países. Más allá de los paralelismos e intercambios argumentales establecidos con la serie original, el presente artículo ofrece un análisis de estas dos adaptaciones dispares con el fin de entender el tipo de representación histórica desde conceptos de transtextualidad e identidad

Porous silicon bragg reflector and 2D gold-polymer nanograting: a route towards a hybrid optoplasmonic platform

Photonic and plasmonic systems have been intensively studied as an effective means to modify and enhance the electromagnetic field. In recent years hybrid plasmonic–photonic systems have been investigated as a promising solution for enhancing light-matter interaction. In the present work we present a hybrid structure obtained by growing a plasmonic 2D nanograting on top of a porous silicon distributed Bragg reflector. Particular attention has been devoted to the morphological characterization of these systems. Electron microscopy images allowed us to determine the geometrical parameters of the structure. The matching of the optical response of both components has been studied. Results indicate an interaction between the plasmonic and the photonic parts of the system, which results in a localization of the electric field profile

Occurrence of the Tamarix Leafhopper, Opsius stactogalus Fieber (Hemiptera: Cicadellidae), in Argentina

The paleartic tamarix leafhopper, Opsius stactogalus Fieber (Hemiptera: Cicadellidae), can reduce the growth of tamarisk due to the aggregate feeding imposed by their populations. The species was mentioned for Argentina in Metcalf's catalogue (1967) without locality or region reference, and the contributions on Cicadellidae published by many authors after Metcalf omitted this distributional data. Populations of O. stactogalus on Tamarix sp. were found in 12 sites between 28° 48′ to 39° 17′ S and 64° 06′ to 70° 04′ W, located in both the Neotropical and Andean biogeographic regions

Vapor phase Beckmann rearrangement using high silica zeolite catalyst

Vapor phase Beckmann rearrangement of cyclohexanone oxime to e-caprolactam has been studied using high silica zeolite catalysts. Catalysts with different crystal sizes and gel-ageing times have been activated by ionic exchange in different conditions by means of a highly basic solution and a nearly neutral solution both containing ammonium salts. Samples have been calcined at different temperatures in order modify the number of defective sites. We observed that samples exchanged by means of a highly basic solution (pH > 10)1,2 and calcined at a relatively lower temperature (450 C) show the most interesting catalytic results. X-ray powder diffraction patterns of these samples show2 retention of the unit cell symmetry (orthorhombic cell) if compared to the dried sample. NH3-TPD confirms the low acidity of high silica zeolites, however a higher amount of desorbed ammonia is observed for the samples exchanged at higher pH and calcined at 450 C. Due to silanol nests the IR spectra of the same samples show the formation of Si\u2013NH2 bonds which are absent in the same material exchanged by other methods. Such sites seem to promote the high stability of the high silica zeolite catalysts also to the regeneration which is needed to remove the heavy carbonaceous compounds from the catalyst surface

Large-scale spatial distribution of breeding Barn Swallows Hirundo rustica in relation to cattle farming

Capsule: The information on the spatial distribution of cattle farming stored in public bovine computerized databases can predict the distribution and abundance of breeding Barn Swallow Hirundo rustica L. across Europe. Aims: To develop and validate models of habitat factors which account for the distribution of breeding Barn Swallow colonies. Results: The models were based on data on the distribution of cattle farming provided by the public Bovine Computerized Database of the Regione Lombardia (northern Italy). Cattle distribution was a strong predictor of presence and size of Barn Swallow colonies as well as of the number of swallow colonies in a municipality. The models were robust and passed a cross-validation procedure and were used to estimate the spatial distribution of about 116,000 breeding pairs in awide area (8695 km(2)) of the low Po plain of northern Italy in 2001. Conclusions: Bovine computerized databases are mandatory in all European Union (EU) countries according to the EU Regulation (CE) 1760/2000. They may serve as a basis for wide scale modelling of the distribution and abundance of breeding Barn Swallow in Europe

Aquivion® PFSA-based spray-freeze dried composite materials with SiO2 and TiO2 as hybrid catalysts for the gas phase dehydration of ethanol to ethylene in mild conditions

Aquivion PFSA resin, a perfluorinated ion-exchange polymer, has been used as a heterogeneous strong acid catalyst for a range of reactions; however, the activity of this material is limited due to the extremely low surface area of the polymer. In this paper we described the one-step synthesis of Aquivion® PFSA-based hybrid materials using heterocoagulation and spray-freeze-drying of sols containing the precursor of the active phases. The intimated encapsulation of different nano-oxides, such as TiO2 and SiO2 in the superacid resin matrix was easily obtained using this technique and compared with similar catalysts prepared by the impregnation conventional route. The approach led to the preparation of porous micro-granules characterised by a high homogeneity in the phase distribution and high surface area. The prepared materials were active and selective for the gas phase dehydration of ethanol to ethylene in mild conditions. The increase of the porosity improved the activity of the composites, compared to the pure Aquivion® PFSA, and allowed to reduce the amount of the superacid resin. Moreover, the type of encapsulated oxide, TiO2 or SiO2, modified the improved performance of the catalysts, having TiO2 the higher efficiency for ethanol conversion and selectivity in ethylene at very low temperature