In-situ technical study of modern paintings part 1: The evolution of artistic materials and painting techniques in ten paintings from 1889 to 1940 by Alessandro Milesi (1856-1945).

A complementary multi-analytical in-situ approach has been adopted for the investigation of a corpus of ten paintings dating from 1889 and 1940 by the Venetian painter Alessandro Milesi (1856-1945), from the collection of the International Gallery of Modern Art Ca' Pesaro in Venice. Analyses were performed in situ with digital imaging, elemental and spectroscopic analysis. The analysis of pigments and binding media and their possible deterioration patterns were studied with a combination of X-Ray Fluorescence (XRF) Spectroscopy, External Reflection- Fourier Transform Infrared Spectroscopy (ER-FTIR) and Raman Spectroscopy. These analytical methods provide information regarding the evolution of the artist's palette and the painting techniques adopted in painting. Data suggest the widespread detection of zinc carboxylates, with implications for conservation and display.

Effect of temperature on the release and remobilization of ecotoxic elements in AMD colloidal precipitates: the example of the Libiola copper mine, Liguria, (Italy).

Due to their characteristics, colloidal particles are able to control the dispersion of many organic and inorganic pollutants in soils and streams. Colloidal precipitates generated by acid mine drainage (AMD) process are usually amorphous or nanocrystalline materials, and their stability plays a crucial role in controlling the fate of metals released by sulphide oxydation. This paper describes a study of elements release (Fe, Al, Mn, Cd, Co, Cr, Cu, Ni, S, Zn) due to desorption or destabilization of three different colloidal precipitates, two ochreous and a greenish-blue precipitate, sampled at the Libiola mine site (northwest Italy). The samples were heated at high temperature in order to verify this treatment as inertization process. At room temperature, the most easily extracted element was S (with released percentages from 8.39 to 29.17 %), but considerable amounts of Cu, Zn and Mn (up to 16.6, 610.6 and 595.6 mg/kg, respectively) were also observed in the leachates for greenish-blue precipitates. The highest release of elements (S > Cu, Zn, Mn, Cd > Co, Ni > Al, Fe, Cr), with minor differences depending on the mineralogical composition of the samples, was observed for heat-treated samples obtained through moderate heating and mainly formed by anhydrous phases. Samples treated at high temperature had the lowest release, with only Cu showing a significant concentration in the leachate of greenish-blue precipitates. The results showed that dissolution/desorption is limited from ochreous natural colloidal precipitates occurring at the Libiola mine site but also that high amounts of some metals can be remobilized from greenish-blue precipitates. The destabilization of all percipitates through dehydratation-dehydroxylation can further remobilize important amounts of ecotoxic elements. Heat treatment at high temperature could be a definitive, although expensive, way to fix heavy metals in the solid fraction, preventing their dispersion in the surrounding environment.

Murine neural stem cells model Hunter disease in vitro: glial cell-mediated neurodegeneration as a possible mechanism involved.

Mucopolysaccharidosis type II (MPSII or Hunter Syndrome) is a lysosomal storage disorder caused by the deficit of iduronate 2-sulfatase (IDS) activity and characterized by progressive systemic and neurological impairment. As the early mechanisms leading to neuronal degeneration remain elusive, we chose to examine the properties of neural stem cells (NSCs) isolated from an animal model of the disease in order to evaluate whether their neurogenic potential could be used to recapitulate the early phases of neurogenesis in the brain of Hunter disease patients. Experiments here reported show that NSCs derived from the subventricular zone (SVZ) of early symptomatic IDS-knockout (IDS-ko) mouse retained self-renewal capacity in vitro, but differentiated earlier than wild-type (wt) cells, displaying an evident lysosomal aggregation in oligodendroglial and astroglial cells. Consistently, the SVZ of IDS-ko mice appeared similar to the wt SVZ, whereas the cortex and striatum presented a disorganized neuronal pattern together with a significant increase of glial apoptotic cells, suggesting that glial degeneration likely precedes neuronal demise. Interestingly, a very similar pattern was observed in the brain cortex of a Hunter patient. These observations both in vitro, in our model, and in vivo suggest that IDS deficit seems to affect the late phases of neurogenesis and/or the survival of mature cells rather than NSC self-renewal. In particular, platelet-derived growth factor receptor-α-positive (PDGFR-α+) glial progenitors appeared reduced in both the IDS-ko NSCs and in the IDS-ko mouse and human Hunter brains, compared with the respective healthy controls. Treatment of mutant NSCs with IDS or PDGF throughout differentiation was able to increase the number of PDGFR-α+ cells and to reduce that of apoptotic cells to levels comparable to wt. This evidence supports IDS-ko NSCs as a reliable in vitro model of the disease, and suggests the rescue of PDGFR-α+ glial cells as a therapeutic strategy to prevent neuronal degeneration.

Highly crystalline strontium ferrites SrFeO(3-δ): an easy and effective wet-chemistry synthesis.

The synthesis of strontium ferrite SrFeO(3-δ) has been explored through wet-chemistry methods in order to optimize a quick, easy and reproducible method to obtain the perovskite in pure crystalline form with a high yield. Among the three investigated synthetic paths, (i) coprecipitation of hydroxides, (ii) coprecipitation of oxalates and (iii) polyol-assisted coprecipitation, only the second one was effective in obtaining the desired perovskite modification as a single phase. The products were analyzed by means of powder X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS), to determine the crystalline structure and the chemical composition of the sample surface, respectively, and to optimise the synthetic process. Pure samples were further characterised by means of inductively coupled plasma (ICP-AES) analysis, nitrogen adsorption, elemental analysis, temperature programmed reduction (TPR) and Mössbauer spectroscopy.