Income dynamics in an enlarged Europe: the role of capital regions

This article is aimed to study, by means of both a nonparametric and a parametric approach to convergence, whether after the recent enlargements of the European Union the traditional twofold spatial regime of regional per capita income growth, envisaging a north/south and/or a cohesion/non-cohesion countries divide, should be replaced by an alternative east/west spatial pattern. A second relevant issue is whether new member regions where capital cities are located are benefiting from the same “network effect” that stimulated growth in old member capital regions during the 1980s and early 1990s. We find evidence, by means of spatial econometrics tools, of significant spatial effects in the enlarged Europe which seems to be formed by a group of old member regions, slowly becoming more homogeneous, and a newcomers group which represents a separate “convergence club” but whose capital regions are rapidly integrating into the west. The European regional policy may play a crucial role in this context.     

Magnetic composites based on bovine serum albumin and poly(aspartic acid)

In this investigation, magnetic polymer composites were developed by using a magnetic field‐assisted strategy. To create the composite, an interpolymeric complex based on bovine serum albumin and poly(aspartic acid) used as a polymer matrix was mixed with pre‐synthesized magnetite nanoparticles and then exposed to a high‐frequency magnetic field. The formation of such composite was confirmed by FTIR‐spectra, scanning electron micrographs, dynamic light scattering measurements, and magnetic susceptibility analysis. The results revealed that the materials have a superparamagnetic behavior and an average hydrodynamic size ranging from 220 to 580 nm. The polymer matrix improved the colloidal stability of the magnetic filler. The proposed composites are expected to be promising candidates for biomedical applications, such as drug delivery systems. POLYM. ENG. SCI., 59:1409–1415 2019. © 2019 Society of Plastics Engineers     

Sr-containing hydroxyapatite: morphologies of HA crystals and bioactivity on osteoblast cells

A series of Sr-substituted hydroxyapatites (HA), of general formula Ca_(10 ? x)Sr_x(PO₄)₆(OH)₂, where x = 2 and 4, were synthesized by solid state methods and characterized extensively. The reactivity of these materials in cell culture medium was evaluated, and the behavior towards MG-63 osteoblast cells (in terms of cytotoxicity and proliferation assays) was studied. Future in vivo studies will give further insights into the behavior of the materials.A paper by Lagergren et al. (1975), concerning Sr-substituted HA prepared by a solid state method, reports that the presence of Sr in the apatite composition strongly influences the apatite diffraction patterns. Zeglinsky et al. (2012) investigated Sr-substituted HA by ab initio methods and Rietveld analyses and reported changes in the HA unit cell volume and shape due to the Sr addition.To further clarify the role played by the addition of Sr on the physico-chemical properties of these materials we prepared Sr-substituted HA compositions by a solid state method, using different reagents, thermal treatments and a multi-technique approach. Our results indicated that the introduction of Sr at the levels considered here does influence the structure of HA. There is also evidence of a decrease in the crystallinity degree of the materials upon Sr addition. The introduction of increasing amounts of Sr into the HA composition causes a decrease in the specific surface area and an enrichment of Sr-apatite phase at the surface of the samples. Bioactivity tests show that the presence of Sr causes changes in particle size and/or morphology during soaking in MEM solution; on the contrary the morphology of pure HA does not change after 14 days of reaction. The presence of Sr, as Sr-substituted HA and SrCl_2, in cultures of human MG-63 osteoblasts did not produce any cytotoxic effect. In fact, Sr-substituted HA increased the proliferation of osteoblast cells and enhanced cell differentiation: Sr in HA has a positive effect on MG-63 cells. In contrast, Sr ions alone, at the concentrations released by Sr-HA (1.21–3.24 ppm), influenced neither cell proliferation nor differentiation. Thus the positive effects of Sr in Sr-HA materials are probably due to the co-action of other ions such as Ca and P.     

Exciton Recombination in Formamidinium Lead Triiodide: Nanocrystals versus Thin Films

The optical properties of the newly developed near‐infrared emitting formamidinium lead triiodide (FAPbI₃) nanocrystals (NCs) and their polycrystalline thin film counterpart are comparatively investigated by means of steady‐state and time‐resolved photoluminescence. The excitonic emission is dominant in NC ensemble because of the localization of electron–hole pairs. A promisingly high quantum yield above 70%, and a large absorption cross‐section (5.2 × 10^?13 cm^?2) are measured. At high pump fluence, biexcitonic recombination is observed, featuring a slow recombination lifetime of 0.4 ns. In polycrystalline thin films, the quantum efficiency is limited by nonradiative trap‐assisted recombination that turns to bimolecular at high pump fluences. From the temperature‐dependent photoluminescence (PL) spectra, a phase transition is clearly observed in both NC ensemble and polycrystalline thin film. It is interesting to note that NC ensemble shows PL temperature antiquenching, in contrast to the strong PL quenching displayed by polycrystalline thin films. This difference is explained in terms of thermal activation of trapped carriers at the nanocrystal's surface, as opposed to the exciton thermal dissociation and trap‐mediated recombination, which occur in thin films at higher temperatures.     

Three-dimensional acquisition of large and detailed cultural heritage objects

Cultural heritage digitization is becoming more common every day, but the applications discussed in the literature address mainly the digitization of objects at a resolution proportional to the object size, using low resolution for large artifacts such as buildings or large statues, and high resolution for small detailed objects. The case studied in this paper concerns a huge physical model of imperial Rome (16 × 17.5 m) whose extremely small details forced the use of high resolution and low noise scanning, in contrast with the long range needed. This paper gives an account of the procedures and the technologies used for solving this “contradiction”.     

Effectiveness of cognitive-load based adaptive instruction in genetics education

Research addressing the issue of instructional control in computer-assisted instruction has revealed mixed results. Prior knowledge level seems to play a mediating role in the student’s ability to effectively use given instructional control. This study examined the effects of three types of instructional control (non-adaptive program control, learner control, adaptive program control) and prior knowledge (high school, 1st year and 2nd year college students) on effectiveness and efficiency of learning in a genetics training program. The results revealed that adaptive program control led to highest training performance but not to superior post-test or far-transfer performance. Furthermore, adaptive program control proved to be more efficient in terms of learning outcomes of the test phase than the other two instructional control types. College students outperformed the high school students on all aspects of the study thereby strengthening the importance of prior knowledge in learning effectiveness and efficiency. Lastly, the interaction effects showed that for each prior knowledge level different levels of support were beneficial to learning.     

Upon the characterization of semi-synthetic hydrogels based on poly (NIPAM) inserted onto collagen sponge

The preparation of a semi-synthetic hydrogel based on poly(N-isopropyl acrylamide-co-diethylene glycol diacrylate) inserted onto a collagen porous membrane, it was previous presented. The synthesis of the hydrogels was performed through radical copolymerization of N-isopropyl acrylamide (NIPAM) with diethylene glycol diacrylate (DEGDA) also as crosslinking agent, using ammonium persulfate as initiator and N,N,N′,N′-tetramethylethylene diamine activator, and it was achieved in the presence of the collagen matrix. In this paper the thus prepared hydrogels are characterized by Differential Scanning Calorimetry, Scanning Electron Microscopy and for their swelling capacities. A kinetic model was studied to investigate the swelling mechanism of the semi-interpenetrated polymeric network. The swelling behavior was found dependent on the hydrogel composition and to the external stimuli such as temperature and pH of environment. This manner of acting recommends these materials as smart materials with potential applications in tissue engineering and pharmaceutical field as for example bioproducts carrier matrices.     

Bionanocomposite Polylactic Acid/Organoclay Films: Functional Properties and Measurement of Total and Lactic Acid Specific Migration

The aim of the work was to manufacture, using a laboratory‐scale film production pilot plant, nanocomposite polylactic acid (PLA) films added with Cloisite 30B clay‐derived nanofiller having one nanometric dimension, and to characterize and to assess the migration of the obtained systems, in view of food packaging applications. The study demonstrated that it is possible to obtain nanocomposite PLA films with intercalated/exfoliated morphology of the dispersed layered nanofiller using conventional film production technologies. With increasing the silicate content in the film, the developed systems show a marked improvement of the mechanical performance, with a rise in the modulus and in the elongation at break with respect to the unfilled PLA, a significant lowering in the oxygen permeability and a slight increase in the surface wettability, without given significant alteration of film transparency and chromatic perception. Compared with the unfilled PLA, no significant changes can be observed about the migration behaviour of the nanocomposite PLA systems. In fact, both the overall migration and the specific migration, measured as lactic acid, remain always well below the applicable generic specific migration limit of 60 mg/kg food (10 mg/dm²) of the Regulation EU 10/2011. Copyright © 2013 John Wiley & Sons, Ltd.     

Development and validation of NIR-chemometric methods for chemical and pharmaceutical characterization of meloxicam tablets

Context: Near-Infrared (NIR) spectroscopy is an important component of a Process Analytical Technology (PAT) toolbox and is a key technology for enabling the rapid analysis of pharmaceutical tablets.

Objective: The aim of this research work was to develop and validate NIR-chemometric methods not only for the determination of active pharmaceutical ingredients content but also pharmaceutical properties (crushing strength, disintegration time) of meloxicam tablets.

Materials and methods: The development of the method for active content assay was performed on samples corresponding to 80%, 90%, 100%, 110% and 120% of meloxicam content and the development of the methods for pharmaceutical characterization was performed on samples prepared at seven different compression forces (ranging from 7 to 45?kN) using NIR transmission spectra of intact tablets and PLS as a regression method.

Results: The results show that the developed methods have good trueness, precision and accuracy and are appropriate for direct active content assay in tablets (ranging from 12 to 18 mg/tablet) and also for predicting crushing strength and disintegration time of intact meloxicam tablets.

Discussion: The comparative data show that the proposed methods are in good agreement with the reference methods currently used for the characterization of meloxicam tablets (HPLC-UV methods for the assay and European Pharmacopeia methods for determining the crushing strength and disintegration time).

Conclusion: The results show the possibility to predict both chemical properties (active content) and physical/pharmaceutical properties (crushing strength and disintegration time) directly, without any sample preparation, from the same NIR transmission spectrum of meloxicam tablets.     

Geographical classification of sicilian olive oils in terms of sterols and fatty acids content

The sterols and fatty acids contents of 22 extravirgin olive oil samples produced in the Etna area and in other areas of Sicily were determined. Principal component analysis (PCA) of these data provided a ‘scores’ plot where samples produced in the Etna area were clearly grouped and unknown samples could be classified according to their geographical origin. This classification was confirmed by the residual standard deviation values of all samples fitted into a disjoint principal components model derived from Etna oils only. The above results suggest that the DOC (denominazlone di origine controllata) origin mark for Etna extravirgin olive oils can be attributed on the basis of their sterols and fatty acids contents by means of PCA.