Diagnostic investigation to support the restoration of the polychrome terracotta relief "Madonna and Child" in Piove di Sacco (Padova, Italy)

Restoration procedures of the polychrome terracotta relief “Madonna and Child” with papier-mâché inserts from a shrine in Piove di Sacco (Padova, orthern Italy) were assisted by analytical investigations, contributing to identify the chemical composition of the pigments, fractures and internal damages, additions and retouchings, which strongly modified the original manufact. In particular, energy dispersive X-ray fluorescence, Raman spectroscopy and FT-IR spectroscopy were employed to determine the chemical composition of pigments on the original layer and on the overpaintings and to understand the artistic techniques. Moreover, X-ray planar radiography and computed tomography were used to understand the structure and its conservative state. Finally, the relief, stylistically dated to the 17th century, turned out to be a Renaissance terracotta artefact. The polychrome blue traces of lapis lazuli highlighted a valuable artwork and the resemblance with the style of Donatello and his apprentices have recently led to further studies, as an initial part of a larger research on polychrome terracotta in Veneto

Plasmonic Light Trapping in Titania–Silver Dots Thin Films

Metal nanoparticles (NPs) in a transparent dielectric matrix represent a very intriguing system due to the plasmonic absorption tunable in the range of visible wavelengths. Herein, the preparation and physical characterization of plasmonic titania–silver dots thin films are reported. The synthesis parameter that leads to making a TiO2 matrix in which the Ag NPs are actually incorporated is carefully analyzed and controlled. Morphological (scanning electron microscopy, transmission electron microscopy, high resolution electron microscopy), structural (selected area diffraction, X-ray diffraction), and spectroscopic (Raman spectroscopy) characterization techniques attest that the Ag NPs are spherical and homogeneously distributed into the TiO2 dielectric matrix in the structural modification of anatase. The study of the optical properties of films concludes the work. Plasmonic resonance is analyzed according to the light scattering theory

The restoration of the Colosso di Barletta: EDXRF analysis

The Colosso di Barletta is an imposing outdoor bronze statue, dating back the V century, located near the Basilica of “Santo Sepolcro” in Barletta (Apulia, Southern Italy). The monument underwent a structural restoration in 1981, during which the Central Institute of Restoration in Rome performed cleaning treatments and consolidation of the patinas. Currently, the Laboratory of Archaeometry of the University of Salento is carrying on a campaign of non-destructive and in situ measurements by using energy dispersion X-ray fluorescence (EDXRF) in order to assess the chemical composition of the alloy and to study its patinas

Climate change impacts on plant phenology: Grapevine (vitis vinifera) bud break in wintertime in southern italy

The effects of global warming on plants are not limited to the exacerbation of summer stresses; they could also induce dormancy dysfunctions. In January 2020, a bud break was observed in an old poly-varietal vineyard. Meteorological data elaboration of the 1951–2020 period confirmed the general climatic warming of the area and highlighted the particular high temperatures of the last winter. Phenological records appeared to be significantly correlated to wood hydration and starch reserve consumption, demonstrating a systemic response of the plant to the warm conditions. The eight cultivars, identified by single-nucleotide polymorphism (SNP) profiles and ampelographic description, grown in this vineyard showed different behaviors. Among them, the neglected Sprino, Baresana, Bianco Palmento, and Uva Gerusalemme, as well as the interspecific hybrid Seyve Villard 12.375, appeared to be the most interesting. Among the adaptation strategies to climate changes, the cultivar selection should be considered a priority, as it reduces the inputs required for the plant management over the entire life cycle of the vineyard. Hot Mediterranean areas, such as Salento, are a battlefront against the climate change impacts, and, thus, they represent a precious source of biodiversity for viticulture

Ion beams delivered by two accelerating gaps for industrial and therapeutic applications

Laser ion sources offer the possibility to get ion beams utilizable to improve particle accelerators. Today many laboratories, as well as the LEAS, are involved to develop accelerators of very contained dimensions, easy to be installed in little laboratories and hospitals. Pulsed lasers at intensities of the order of 108 W/cm2 and of ns pulse duration, interacting with solid matter in vacuum, produce plasma of high temperature and density. The charge state distribution of the plasma generates high electric fields which accelerate ions along the normal to the target surface. The energy of emitted ions has a shifted Maxwell-Boltzmann distribution which depends on the ion charge state. To increase the ion energy, a post-acceleration system can be employed by means of high voltage power supplies of about 100 kV. The post acceleration system results a good method to obtain high ion currents using a not expensive system and the final ion beams find interesting applications in the field of the ion implantations, hadrontherapy, scientific applications and industrial use. In this work we study the electromagnetic and geometric proper-ties, like the emittance of the beams delivered by Cu target. Plasma‟s characterization was performed us-ing a Faraday cup for the electromagnetic characteris-tics, while for the geometric ones by adopting a pep-per pot system. Applying 60 kV of accelerating volt-age and a laser irradiance of 0.1 GW/cm2, we obtain 5.5 mA of output current and a normalized beam emittance of 0.2 π mm mrad. The brightness of the beams was 137 mA(p mm mrad)-2

Study of Faraday cups for fast ion beams provided by a LIS source

Faraday cups are widely utilized to characterize ion and electrons beams. Owing to the secondary electron emission (SEE) induced by the collision of beams with collectors, wrong measurements could emerge from these detectors. To overcome this problem a polarized grid is utilized in front the cup collector at a negative voltage with respect to the collector. Unfortunately, the high voltage connection of the Faraday cups is hard to obtain. Then, in this work we want to study the secondary emission on different Al ion collector designs having tilted surfaces with respect to beam axis. Tests were performed using ion beams accelerated by a power supply up to 40 kV. The results by the modified collector surfaces were compared to the ones performed with a simple flat collector. The results we obtained point out that the secondary electron emission enhanced on incident beam energy and on the angle with respect to the normal direction of the surface. The ratio of the SEE to angle value results constant for the accelerating voltage and the possibility to design an ion collector able to reset the SEE seems not to be reached

Characterization of the Airborne Microbiome in Different Indoor and Outdoor Locations of a University Building Using an Innovative Compositional Data Analysis Approach

In this work, we investigated the structure of the airborne bacterial community obtained by 16S rRNA gene sequencing performed on aerosol samples from different indoor and outdoor locations. The 48-h aerosol samples were collected in two laboratories, in the corridors, and on the roof of the Mathematics and Physics Department of the University of Salento (Italy). The investigation was carried out through the application of an innovative compositional data analysis approach, mainly based on a centered log-ratio transformation as a standardization procedure, the Aitchison distance for data ordination, and the principal component analysis via singular value decomposition for data clustering. This methodology allowed us to explore the main relationships among samples, identifying different results between indoor and outdoor samples both at the genus level and at the species level. Bacillus and Pseudomonas represented the most abundant genera identified in the analyzed samples. Out of the 21 identified bacterial species with the highest abundances in the collected aerosol samples, Acinetobacter lwoffii, Propionibacterium acnes, Diplorickettsia massiliensis, and Corynebacterium tuberculostearicum were the only four commonly classified as human opportunistic pathogens. Among the genera mostly associated with indoor environments, Hymenobacter and Arthrobacter could be noted as including many species that are unique in being radiation resistant

Misure di radioattività naturale nel sito preistorico di Grotta dei Cervi in Porto Badisco (LE)

Nel presente lavoro sono riportati I risultati di una campagna di misure finalizzata alle determinazione della concentrazione di radon all’interno di Grotta dei Cervi di Porto Badisco (LE). Grotta dei Cervi è una cavità carsica caratterizzata da un complesso pittorico neolitico imponente

Caratterizzazione di Batteri Vibrio harveyi irradiati con luce UV e raggi X

Lo studio dei batteri sottoposti a stimolazioni dovute all'ambiente è di estremo interesse per impli-cazioni strutturali, meccanicistiche ed evolutive. Bat-teri luminescenti evoluti in determinati ambienti han-no sviluppato particolari risposte e il loro comporta-mento può fornire informazioni sulla funzione e sulla produzione dell‟enzima luciferina. Per esaminare l'in-terazione con radiazione UV, in condizioni controlla-te di laboratorio sono stati utilizzati ceppi batterici foto-luminescenti appartenenti alla specie Vibrio har-veyi campionati da una grotta costiera con elevato contenuto di radon che genera radiazioni ionizzanti. La sopravvivenza dei ceppi batterici è stata analizza-ta, alla luce e al buio, a seguito di una varietà di trat-tamenti genotossici tra cui esposizione alle radiazioni UV. I ceppi sono stati irradiati mediante una lampada germicida. I risultati hanno dimostrato che la maggior parte dei ceppi esibiscono un basso tasso di sopravvi-venza dopo l'esposizione ai raggi UV. Tutti i ceppi dopo esposizione a luce visibile e ai raggi UV hanno mostrato una forte capacità di fotoriattivazione. Que-sta capacità era inaspettata, poiché questi batteri sono stati prelevati da un ambiente buio in assenza raggi UV. Questo porta ad ipotizzare che la fotoriattivazio-ne in questi batteri potrebbe essere stata sviluppata dagli stessi per riparare le lesioni del DNA provocate anche da radiazioni diverse dall‟UV (ad esempio, raggi X) e che i batteri luminescenti potrebbero usare la luce da essi emessa per effettuare la fotoriattivazio-ne. L'elevata capacità di fotoriattivazione dei batteri è stata anche confermata dai risultati di deconvoluzio-ne. La deconvoluzione è stata applicata agli spettri di emissione che ha evidenziato la presenza di diversi picchi. La presenza del picco nel visibile è in grado di controllare l'enzima fotoliasi

Oral complications of Type 1 diabetes mellitus in a non-smoking population

Type 1 diabetes mellitus (T1DM) is a complex metabolic condition that results in hyperglycemia due to insulin deficiency (Daneman, 2006). Diabetes has a range of effects on almost every system in the body including the kidneys, the eyes, the cardiovascular system, the genito-urinary system, the gastro-intestinal system and the nervous system (Daneman, 2006). The effects of this ondition are widespread and have a significant impact both on life expectancy and the quality of life of individuals suffering from diabetes (Scottish Diabetes Survey Monitoring Group, 2011). The impact of diabetes on oral health has been investigated over many decades, however, the conclusions have been varied and study design has not always been adequate (Mealey et al., 2006; Khader et al., 2006; Chávarray et al., 2009). Research presented in this thesis is largely the result of a cross-sectional clinical study examining the oral cavities of non-smoking T1DM patients, funded by the Chief Scientist Office of the Scottish Government. The clinical part of the study took place between January 2006 and May 2009 in Glasgow Dental Hospital. Chapter one provides an introduction and narrative review on the subject of T1DM, periodontal disease, and the various other reported oral manifestations of diabetes mellitus. The methods for measuring general and oral health related quality of life outcomes are also discussed. Chapter one reveals some of the inadequacies of studies nvestigating the link between T1DM and oral disease to date and ontextualises the studies presented in this thesis. Chapter two presents the main periodontal findings of a large cross-sectional study. 112 non-diabetic subjects and 203 subjects with type 1 diabetes were examined. 203 diabetic patients were divided into well controlled and poorly controlled groups based on their average blood sugar levels over the previous two years. 169 were poorly controlled. (PCD). Those with T1DM, (especially those with poor glycaemic control) had a greater extent and severity of periodontitis than those without diabetes. There was also some evidence that never smoking T1DM patients were more likely to have periodontal disease than non-diabetic subjects. The odds ratio (OR) was 1.43 [0.74 to 2.75] (p = 0.29) for all T1DM patients and 1.58 [0.75 to 3.33] (p = 0.23) for PCD. This difference remained even after the multivariable analysis took into account age, gender and lifestyle including: body mass index of the subject; whether they had smoked in the past; whether they attended a dentist; their level of education and how deprived the area they lived in was. Chapter three presents an analysis of the impact of age, HbA1c, and duration on the expression of periodontal disease in T1DM subjects. Cross-tabulations and multivariable logistic regression analysis was performed on the periodontal data from T1DM subjects and non-diabetic subjects in order to determine the relationship between age, HbA1c and duration, and periodontitis. Diabetic subjects developed periodontitis at a younger age than non-diabetes subjects. This will represent a significant impact on life time dental service provision for subjects affected at a young age. The relationship between HbA1c and severe periodontitis is not a simple one. It is possible that unknown factors confound the relationship between glycaemic control and periodontitis. There was no relationship between duration of diabetes and periodontitis when age was controlled for. Chapter four presents the results of a small study investigating biomarkers of bone turnover in patients with and without T1DM and in patients with and without periodontitis. Patients with T1DM had higher levels of osteoprotegerin an osteoprotective molecule that normally leads to a reduced propensity for bone loss. T1DM patients were also shown to have reduced levels of biomarkers of bone formation (osteocalcin). It is possible that a reduced capacity for bone repair and regeneration may account for the increase levels of periodontitis seen in T1DM. Further prospective studies would be required to confirm this hypothesis. Chapter five investigated the level of caries and oral mucosal abnormalities in T1DM. There was little difference in caries indicators or in oral mucosal lesions between the groups. There was no difference in the bacterial microflora and in the level of resistance to antibiotics found in this cohort. T1DM patients, however, did have an increase in the symptoms of dry mouth, an increased density of candida colonisation and reduced salivary flow rates.Chapter six reports the data derived from the oral health questionnaire, including the Oral Health Impact Profile -14 (OHIP-14) and the Audit of Diabetes Dependent Quality of Life (ADDQOL©). Patients with T1DM, despite having increased levels of periodontal disease, reduced salivary flow rates and increased symptoms of xerostomia did not have higher OHIP scores by any measure. The reasons for this apparently negligible impact of oral disease or oral health related quality of life are discussed. The OHIP-14 was shown to have construct validity in this population although the correlations were relatively weak and the differences were small. It is possible that patients with T1DM do not consider the impact of their oral health to be a significant problem in light of their other on-going medical issues. This finding requires further in-depth investigation of the psychology behind this apparent reduced impact. This is the first study of its kind to examine the oral and dental health of non-smoking type 1 diabetic patients. The conclusions from the clinical data support the view that patients with T1DM should be targeted with oral and dental health advice. Encouragingly the prevalence of periodontitis was lower in well controlled diabetic subjects suggesting that the effect of T1DM on the oral cavity can be ameliorated by good glycaemic control even though logistic regression analysis did not show a linear relationship. It is important that health rofessionals work together in order to prevent and manage the oral complications of T1DM in the same way that there are preventive and screening programmes for other diabetic complications. The pathogenesis behind the increased prevalence and severity of periodontal disease in T1DM requires further study.EThOS - Electronic Theses Online ServiceGBUnited Kingdo