Study of the effects of salt crystallisation on degradation of limestone rocks

Salt crystallization is widely recognized as a cause of deterioration of porous building materials. In particular, the crystallization pressure of salt crystals growing in confined pores is found to be the main cause for damage. The aim of this study is to better understand the degradation of porous rocks induced by salt crystallisation and correlate such processes with the intrinsic characteristics of materials. With this intend, an experimental salt weathering simulation has been carried out on two limestones widely used in the Baroque architecture of eastern Sicily. A systematic approach including petrographic, porosimetric and colorimetric analyses, was used to evaluate the correlation among salt crystallisation, microstructural and chromatic variations of limestone. Results showed a quite different resistance of the two limestones to salt damage, and this was found to be strongly dependent on their pore structure and textural characteristics

RBS, PIXE, Ion-Microbeam and SR-FTIR Analyses of Pottery Fragments from Azerbaijan

The present work is aimed at the investigation of the ceramic bulk and pigmented glazed surfaces of ancient potteries dating back to XIX century A.D. and coming from the charming archeological site located in the Medieval Agsu town (Azerbaijan), a geographic area of special interest due to the ancient commercial routes between China, Asia Minor, and Europe. For the purpose of the study, complementary investigation tools have been exploited: non-destructive or micro-destructive investigation at elemental level by ion beam analysis (IBA) techniques, by using Rutherford Backscattering Spectrometry (RBS), Proton-Induced X-ray Emission (PIXE) spectroscopy and ion-microbeam analysis, and chemical characterization at microscopic level, by means of synchrotron radiation (SR) Fourier transform infrared (FTIR) microspectroscopy. The acquired information reveals useful for the identification of the provenance, the reconstruction of the firing technology, and finally, the identification of the pigment was used as a colorant of the glaze

Spectroscopic investigation of Roman decorated plasters by combining FT-IR, micro-Raman and UV-Raman analyses

In this work, the complementary use of Fourier transform infrared (FT-IR) spectroscopy, conventional micro-Raman spectroscopy and UV-Raman scattering proved successful for the characterization of bulk minerals and of a variety of pigments from decorated finishing layers of plasters from a Roman archaeological site known as Villa dei Quintili, a monumental residence located in the south-eastern part of Rome (Italy). The used multi-technique approach provided insights on the pictorial technique, giving information that could be useful for proper restoration. It is worth underlining that the present study represents the first attempt of carrying out UV resonance Raman measurements for analysing cultural heritage materials

Design and development of a peptide-based adiponectin receptor agonist for cancer treatment

<p>Abstract</p> <p>Background</p> <p>Adiponectin, a fat tissue-derived adipokine, exhibits beneficial effects against insulin resistance, cardiovascular disease, inflammatory conditions, and cancer. Circulating adiponectin levels are decreased in obese individuals, and this feature correlates with increased risk of developing several metabolic, immunological and neoplastic diseases. Thus, pharmacological replacement of adiponectin might prove clinically beneficial, especially for the obese patient population. At present, adiponectin-based therapeutics are not available, partly due to yet unclear structure/function relationships of the cytokine and difficulties in converting the full size adiponectin protein into a viable drug.</p> <p>Results</p> <p>We aimed to generate adiponectin-based short peptide that can mimic adiponectin action and be suitable for preclinical and clinical development as a cancer therapeutic. Using a panel of 66 overlapping 10 amino acid-long peptides covering the entire adiponectin globular domain (residues 105-254), we identified the 149-166 region as the adiponectin active site. Three-dimensional modeling of the active site and functional screening of additional 330 peptide analogs covering this region resulted in the development of a lead peptidomimetic, ADP 355 (H-DAsn-Ile-Pro-Nva-Leu-Tyr-DSer-Phe-Ala-DSer-NH₂). In several adiponectin receptor-positive cancer cell lines, ADP 355 restricted proliferation in a dose-dependent manner at 100 nM-10 μM concentrations (exceeding the effects of 50 ng/mL globular adiponectin). Furthermore, ADP 355 modulated several key signaling pathways (AMPK, Akt, STAT3, ERK1/2) in an adiponectin-like manner. siRNA knockdown experiments suggested that ADP 355 effects can be transmitted through both adiponectin receptors, with a greater contribution of AdipoR1. <it>In vivo</it>, intraperitoneal administration of 1 mg/kg/day ADP 355 for 28 days suppressed the growth of orthotopic human breast cancer xenografts by ~31%. The peptide displayed excellent stability (at least 30 min) in mouse blood or serum and did not induce gross toxic effects at 5-50 mg/kg bolus doses in normal CBA/J mice.</p> <p>Conclusions</p> <p>ADP 355 is a first-in-class adiponectin receptor agonist. Its biological activity, superior stability in biological fluids as well as acceptable toxicity profile indicate that the peptidomimetic represents a true lead compound for pharmaceutical development to replace low adiponectin levels in cancer and other malignancies.</p

Conservare i murales outdoor: alcuni esempi romani.

Il tema della conservazione in situ di opere murali outdoor \ue8 al centro, negli ultimi tempi, di un accesso dibattito soprattutto in relazione al differente approccio da adottare a seconda che l\u2019opera sia un murale oppure un dipinto murale. Fino a pochi anni fa l\u2019interesse crescente per la conservazione della cosiddetta \u201cstreet art\u201d ha portato alla ricerca di nuove metodologie e alla sperimentazione di nuovi prodotti da applicare sulle opere al fine di garantirne la durabilit\ue0 nel tempo. Attualmente il restauratore/conservatore che si trova di fronte ad un\u2019opera di \u201cUrban Art\u201d deve adottare un approccio conservativo molto pi\uf9 cauto ponendosi alcune questioni preliminari legate alla reale necessit\ue0 di proteggere e salvare le opere di arte urbana realizzate da artisti che lavorano in ambienti esterni

Major factors controlling Late Pleistocene to Holocene soil development in the Vesuvius area (southern Italy)

In this paper the role of time and late Pleistocene to middle Holocene climate changes in the Somma-Vesuvius volcano foothill (southern Italy) is investigated with a multidisciplinary approach. Four volcanic soils inter-layered between five well-known and well-dated primary tephra layers were characterized. Chronological constraints were provided by the pyroclastic layers identified in the field (Pomici di Base, Pomici Verdoline, Agnano Pomici Principali, Mercato and Avellino), ranging between 22 and 3.8 thousand years (ka) before present (BP). These represent products of explosive eruptions of Somma-Vesuvius and the Phlegrean Fields. Another pyroclastic layer (Agnano Monte Spina) from the Phlegrean Fields was also identified, and other ash layers previously unknown in the Somma-Vesuvius stratigraphy. These were characterized with SEM-EDS analyses, and correlated with other eruptions from the Phlegrean Fields (Soccavo 4-5 and Tufi Biancastri) around 12 and 21 ka BP, respectively, thus resulting in further time constraints for phases of soil development. A detailed characterization of the four pedons integrated morphological, physical, chemical, mineralogical and micromorphological analyses. Soil features were interpreted in terms of dominant genetic processes and environmental conditions. The extent of soil development, assessed with pedogenetic indices and the degree of weathering of primary pumices, was only in part consistent with time-spans of soil formation, suggesting a more important role of climate than soil age. The different extents of expression of andic properties, pumice weathering and varying clay mineralogy allowed us to relate changes to the main climatic phases that occurred during the late Pleistocene to the mid Holocene. © 2014 British Society of Soil Science