XRD analysis of patinas on the monument dedicated to Saint Oronzo, Lecce

The monument dedicated to Saint Oronzo is placed in the homonymous square in the city centre of Lecce (Southern Italy). This monument consists of an internal wooden structure that is completely covered with copper sheets, lying on a concrete base about 1.5 meters high, which is placed on a Roman column about 29 meters high. The restoration of this manufact started in June 2018 and, first of all, non-destructive analyses are planned as proposed in the time-schedule. In this paper, we show the results of X-ray diffraction (XRD) analysis of the patinas both of the statue and of the column in order to evaluate their composition

Synthesis and in vitro cytotoxicity of glycans-capped silver nanoparticles

Silver nanostructures were successfully synthesized through a simple and "green" method using saccharides as reducing and caping agent. Transmission electron microscopy (TEM) and UV-Vis absorption were used to certify the quality of the silver nanoparticles obtained: firstly, size and dispersion. In this work Silver NanoParticles (AgNPs) cytotoxicity related to saccharides capping (Glucose and (GlucoseSucrose) was explored in human epithelia cervix carcinoma cells (HeLa). The cells were incubated with increasing AgNPs number/cell and HeLa cells viability was monitored for a period of 48 h compared with the positive and negative controls. We observed that the toxicity increases with incubation time and with AgNPs number/cell. In particular, the different cytotoxic degree of the AgNPs, i.e. AgNP-G are more toxic than AgNP-GS, suggest that the cytotoxic effects are largely depended on the capping agent. The highest concentration of AgNP-G number/cell is able to induce extensive cell death of HeLa cells soon after 1hr of incubation; conversely the lowest concentration of AgNP-GS number/cell, surprisingly, is able to induce cell proliferation

Sub-nanomolar detection of biogenic amines by SERS effect induced by hairy Janus silver nanoparticles

Surface enhanced Raman scattering (SERS) is largely used as a transduction method for analytes detection in liquid and vapor phase. In particular, SERS effect was promoted by a plethora of different metal and semiconducting nanoparticles (NPs) and silver and gold nanoparticles appear particularly suitable for this application. Nevertheless, silver nanoparticles intrinsic propensity to aggregate in large clusters reduces the possibility to use naked nanoparticles in SERS applications, for this reason they are usually functionalized with organic molecules. This approach inhibits the aggregation process but, on the other hand, reduces the surficial area of the NPs able to interact with the analyte molecules. In the present work, we propose a simple method to obtain surficial anisotropic Janus silver nanoparticles: octadecylamine was used to stabilize the nanoparticles and to promote the deposition of the silver nanoparticles on a solid substrate. The AgNPs/octadecylamine nanostructures showed the typical “hairy” Janus morphology and a strong SERS effect was observed when two biogenic amines, i. e. 2-phenylethylamine and tyramine, were fluxed on the solid film. SERS phenomenon was studied as a function both of the chemical structure of the fluxed amine and of the distance between the aromatic moiety and the nanoparticle allowing to propose the AgNPs/octadecylamine Janus nanoparticles as an active layer for the detection of phenylethylamine and tyramine in picomolar concentration

Gold leafs in 14th century Florentine painting

Gold leafs are typically present in paintings and frescoes of the Italian Renaissance in the 13th and 14th centuries. The chemical composition and thickness of gold leafs provide important information toward a better understanding of the technology of that epoch. The present paper discusses the results of non-destructive analysis carried out with a portable energy dispersive X-ray fluorescence (ED-XRF) equipment on the 14th century panel Annunciation with Saints Catherine of Alexandria, Anthony Abbot, Proculus and Francis by the painter Lorenzo Monaco.L’application de feuilles d’or sur des tableaux et des fresques est typique de la Renaissance italienne aux xiiie et xive siècles. Leur composition chimique et leur épaisseur fournissent des informations importantes pour la compréhension des techniques de cette période. Ce travail discute les résultats des analyses non-destructives réalisées avec un système portable de fluorescence X à dispersion d’énergie (ED-FX) sur le panel du xive siècle Annonciation avec Saints Catherine d’Alexandrie, Anthony Abbot, Proculus et Francis par le peintre Lorenzo Monaco

High ordered biomineralization induced by carbon nanoparticles in the sea urchin Paracentrotus lividus

A surprising and unexpected biomineralization process was observed during toxicological assessment of carbon nanoparticles on Paracentrotus lividus (sea urchin) pluteus larvae. The larvae activate a process of defense against external material, by incorporating the nanoparticles into microstructures of aragonite similarly to pearl oysters. Aiming at a better understanding of this phenomenon, the larvae were exposed to increasing concentrations of carbon nanoparticles and the biomineralization products were analyzed by electron microscopy, x-ray diffraction and Raman spectroscopy. In order to evaluate the possible influence of Sp-CyP-1 expression on this biomineralization process by larvae, analyses of gene expression (Sp-CyP-1) and calcein labeling were performed. Overall, we report experimental evidence about the capability of carbon nanoparticles to induce an increment of Sp-CyP-1 expression with the consequent activation of a biomineralization process leading to the production of a new pearl-like biomaterial never previously observed in sea urchins

MODIFICATION OF Pd-H2 AND Pd-D2 THIN FILMS PROCESSED BY HE-NE LASER

We have performed experiments of absorption of hydrogen and deuterium gas by Pd thin films and we have studied the behavior of these samples compared with non processed ones. We have also employed, during the treatment, a continuous wave He-Ne laser to irradiate the samples inside the chamber in order to increase the gas absorption. By a scanning electron microscope (SEM) and an electron probe micro analyzer (EDX) we have observed, on the surface of the treated samples, the presence of structures like spots and inside them different elements from Pd. By these results we can say that the gas loading has been a very important condition to produce “transmutation” elements and the laser action has been very interesting in order to increase the morphological modifications of the treated samples

Determinazione del livello di radon nella grotta della Zinzulusa, Castro (LE)

In questo lavoro sono riportati i risultati speri-mentali delle determinazioni di radon in acqua e in aria effettuate nella grotta della Zinzulusa (Castro, Lecce). Tale campagna di misura ha consentito di valutare i livelli di questo importante gas radioattivo in un famoso e suggestivo luogo turistico del Salento. I dati ottenuti, per la prima volta nella grotta, possono essere confrontati con i valori delle normative vigenti in materia di sicurezza sul posto di lavoro. Questo risultato è di basilare importanza per la salute dei turisti, delle guide e di tutti coloro che operano nella grotta

Relaxation from a voluntary contraction is preceded by increased excitability of motor cortical inhibitory circuits.

none3BUCCOLIERI A.; G. ABBRUZZESE; ROTHWELL JCBuccolieri, A.; Abbruzzese, Giovanni; Rothwell, J