5 research outputs found
Water Diffusion through a Titanium Dioxide/Poly(Carbonate Urethane) Nanocomposite for Protecting Cultural Heritage: Interactions and Viscoelastic Behavior
Water diffusion through a TiO2/poly (carbonate urethane) nanocomposite designed for the eco-sustainable protection of outdoor cultural heritage stonework was investigated. Water is recognized as a threat to heritage, hence the aim was to gather information on the amount of water uptake, as well as of species of water molecules absorbed within the polymer matrix. Gravimetric and vibrational spectroscopy measurements demonstrated that diffusion behavior of the nanocomposite/water system is Fickian, i.e., diffusivity is independent of concentration. The addition of only 1% of TiO2 nanoparticles strongly betters PU barrier properties and water-repellency requirement is imparted. Defensive action against penetration of water free from, and bonded through, H-bonding association arises from balance among TiO2 hydrophilicity, tortuosity effects and quality of nanoparticle dispersion and interfacial interactions. Further beneficial to antisoiling/antigraffiti action is that water-free fraction was found to be desorbed at a constant rate. In environmental conditions, under which weathering processes are most likely to occur, nanocomposite Tg values remain suitable for heritage treatments
Copper Minerals at Vesuvius Volcano (Southern Italy): A Mineralogical Review
This work is part of a project focused on the Somma–Vesuvius volcano and aimed at identifying Cu minerals related to mineralizing processes associated with magmatic activity in an active magmatic-hydrothermal system. A mineralogical survey was carried out on a set of samples represented by sublimates and fumarolic products from the collection of the Mineralogical Museum of the University of Naples Federico II (Italy). These samples are mainly related to most recent eruptive episodes of Vesuvius activity, from 1631 onward. Copper-bearing minerals were characterized, as well as associated minerals, by X-ray diffraction (XRD) scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDS). An investigation on the structural complexity of Cu-mineral assemblages with different temperature formations was also carried out using the TOPOS software package. The main copper phases are sulfates, followed by vanadates, hydroxyhalides, oxides, carbonates, silicates and finally, phosphates. New mineral occurrences for Vesuvius, both Cu-bearing and Cu-free, are described. Nevertheless, the fumarolic/alteration minerals at Vesuvius cannot be considered of economic relevance as a copper reservoir, this type of mineralizations are significant for copper crystal chemistry and for the knowledge of the mineralogical variants. The obtained datasets can be of interest for the knowledge of volcanic byproducts of copper ore deposits (i.e., porphyry copper systems) and of (base) metal segregation processes
HLA-G expression and regulation during Pseudomonas aeruginosa infection in cystic fibrosis patients.
Background Deregulated immune response fails to control biofilm-forming bacteria, as P.aeruginosa, in the lung of Cystic Fibrosis (CF) patients. HLA-G is an immune-modulatory molecule involved in respiratory diseases and infections. Methods HLA-G mRNA and protein were analyzed in plasma and exhaled breath condensate from CF patients undergoing intravenous antibiotic treatment, CF cell line and murine model. Results Therapy normalizes HLA-G plasmatic in CF patients suggesting a systemic anti-inflammatory role while in CF airway system, higher expression of HLA-G is associated with P.aeruginosa infection. CF cell line and murine model expressed higher HLA-G molecules in the presence of P.aeruginosa. Conclusions Plasmatic and lung HLA-G expression suggest a role in reducing systemic inflammation and supporting P.aeruginosa infection
The history of the “Virgin with Child” sculpture (Ottaviano, Naples,southern Italy): Hypotheses from archaeometric multi-technique investigations
A life-size whitish marble statue of a “Virgin with Child” has been recently rediscovered in the St. Rosario church located in Ottaviano, a small town near Naples (southern Italy). This artwork shows stylistic fea- tures of the Tuscan-Roman school of the 16th century, and is framed in an intriguing historical context. Historical documents testify that the sculpture was a property of the cadet branch of noble Tuscan family of the Medici, the Medici of Ottaviano. A multianalytical approach has been used to try to indicate the supply area of the white marble of the studied sculpture. Considering the whole mineralogical, petro- graphic and geochemical data, the source rock can be possibly limited to the main classical white marbles of the Mediterranean district, as the classical marble of Aphrodisias. A reuse practice of a former artwork can be also hypothesized.