284 research outputs found

    Fused Filament Fabrication and Computer Numerical Control Milling in Cultural Heritage Conservation

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    This paper reports a comparison between the advantages and disadvantages of fused filament fabrication (FFF) and computer numerical control (CNC) milling, when applied to a specific case of conservation of cultural heritage: the reproduction of four missing columns of a 17th-century tabernacle. To make the replica prototypes, European pine wood (the original material) was used for CNC milling, while polyethylene terephthalate glycol (PETG) was used for FFF printing. Neat materials were chemically and structurally characterized (FTIR, XRD, DSC, contact angle measurement, colorimetry, and bending tests) before and after artificial aging, in order to study their durability. The comparison showed that although both materials are subject to a decrease in crystallinity (an increase in amorphous bands in XRD diffractograms) and mechanical performance with aging, these characteristics are less evident in PETG (E = 1.13 +/- 0.01 GPa and sigma = 60.20 +/- 2.11 MPa after aging), which retains water repellent (ca = 95.96 +/- 5.56 degrees) and colorimetric ( increment E = 2.6) properties. Furthermore, the increase in flexural strain (%) in pine wood, from 3.71 +/- 0.03% to 4.11 +/- 0.02%, makes it not suitable for purpose. Both techniques were then used to produce the same column, showing that for this specific application CNC milling is quicker than FFF, but, at the same time, it is also much more expensive and produces a huge amount of waste material compared to FFF printing. Based on these results, it was assessed that FFF is more suitable for the replication of the specific column. For this reason, only the 3D-printed PETG column was used for the subsequent conservative restoration

    The use of Laser ablation-inductively coupled plasma-mass spectrometry (LA-ICPMS) in the study of Cultural Heritage

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    Several analytical techniques are actually employed for the study of Cultural Heritage and permit to identify production methodologies, constituent materials, degradation products, dating and provenance of the objects examined; elemental analyses provide precious information to archaeologists, art historians, restorers and analysts, opening a door into the past. Those techniques capable of ensuring versatility of application, sensitivity and non-destructive or micro-invasive analysis are generally requested. Laser ablation–inductively coupled plasma–mass spectrometry (LA-ICPMS), by virtue of its effective lateral resolution, sensitivity to most elements and capacity of outdoing limitations due to the low quantity of accessible samples, fulfils these requirements. Multivariate statistical techniques applied to the elemental data permit classification and provenance of artistic objects and allow to confute or confirm historical hypotheses. In the present work several case studies, addressed recently by the authors concerning objects of artistic and historical value, are outlined: pottery and glazes of Vesuvian area (Campania, Italy), fibulae of Egnatia (Puglia, Italy), inks of painting of Sant’Irene by Giuseppe Verrio and lime mortars from Siponto (Puglia, Italy). For each of the presented activity, results, advantages and drawbacks of the LA-ICPMS were discussed

    Historically Accurate Reconstruction of the Materials and Conservation Technologies Used on the Facades of the Artistic Buildings in Lecce (Apulia, Italy)

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    The protection of the stone surfaces of the buildings of the city of Lecce (Apulia, Italy) represents an ancient practice, which has always allowed the conservation of the historical-artistic heritage of the city, which nowadays is an international touristic and cultural destination. The identification of ancient recipes, materials and methodologies for the protection of historical buildings plays an important role in establishing correct protocols in order to ensure the durability of stone surfaces over time. This work presents a historically accurate reconstruction of the materials and conservation technologies used on the facades of the artistic buildings in Lecce. Several historical buildings, both civil and religious, have been selected in order to investigate the treatments applied on their facades and to know the traditions spread in the past in the field of building conservation in the Salento territory. Thanks to non-invasive or micro-destructive techniques (optical microscopy, ATR-FTIR spectroscopy, pyrolysis–gas chromatography–mass spectrometry), the characteristic molecular markers of the materials and the products of degradation have been identified, deepening the knowledge of the mechanisms of deterioration and interaction between the stone material, the surface finish and the surrounding environment. The paper is a valuable tool for the knowledge of ancient traditions and the planning of proper restoration works

    ARCHAEOLOGICAL MATERIALS FROM GABII (CENTRAL ITALY): KNOWLEDGE OF OFFERINGS AND RITUALS AT THE INFANT BURIALS THROUGH AN INTEGRATED APPROACH

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    The ancient Latin city of Gabii is situated 18 km (11.2 miles) to the east of Rome (Central Italy) along the modern Via Prenestina. Gabii was a renowned city in Roman times, particularly during the Republican period and there are various influences in the site that can be identified in Roman culture itself. Gabii is also one of the most significant and important archaeological sites in the territory of the Municipality of Rome and due to its characteristics, it represents today an extraordinary research context. From the excavations carried out in the past it is possible to see how, under the soil, the main structures and buildings of the ancient city are still largely preserved. Among the various testimonies of the past, the tombs, and the micro and macro remains that these contain, represent an opportunity to investigate such practices in the context of Early Iron Age and Orientalizing Latium. In particular, the finds from the Area D baby burials of Gabii enriched the existing dataset so far significantly, allowing us to explore funerary ritual behavior in a more systematic way. This work reports the results of the detailed examination of four tombs (Tombs 30, 50, 51 and 52) of archaeological site. The field strategy for the excavation of the tombs was geared from the start towards both the systematic retrieval of archaeobotanical and zooarchaeological remains and the sampling for organic residue analysis. Aiming for total recovery, the sediments from the tomb fills were sifted in their entirety as their stratigraphic excavation progressed, and samples were taken for flotation. This careful screening allowed for the detection of concentrations of organic material that represent plant and/or animal depositions. The excavation and removal of the grave goods was carried out following strict protocols for residue sampling, minimizing the risk of organic contamination. Samples were analysed by High Temperature Gas Chromatography/Mass Spectrometry (HTGC/MS) and Gas chromatography/Combustion/Isotope ratio mass spectrometry (GC-C-IRMS). For each burial, a subset of vessels including both closed and open shapes was selected, such as cups, open bowl without foot, amphoretta, amphora with dots, Kantharos, plate on a foot, olla, and olpe in bucchero. The results demonstrate the still largely unexploited potential of this sort of integrated studies, encouraging us to expand the application of chemical methods to contexts from other well–controlled excavations

    Tools to tie: Flower characteristics, voc emission profile, and glandular trichomes of two mexican salvia species to attract bees

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    A plant can combine physical and chemical tools to interact with other organisms. Some are designed for pollinator attraction (i.e., colors and volatile organic compounds-VOCs); others can act to discourage herbivores (i.e., non-glandular trichomes). Few studies fully address available tools in a single species; notwithstanding, this information can be pivotal in understanding new interactions out of the home range. We characterized flower traits, emission profiles of constitutive compounds from flowers and leaves, micro-morphology of the glandular trichomes, and listed flower visitors of two Mexican bird-pollinated Salvia species (S. blepharophylla and S. greggii), growing in an Italian botanical garden. Flowers were highly variable in their morphometric characteristics. In both species, four trichome morphotypes with similar histochemistry and distribution were documented for leaves and flowers except the calyx abaxial side. The vegetative emission profiles were qualitatively more complex than the floral ones; however, common compounds occurring in high relative percentages were β-caryophyllene and germacrene D. Floral bouquets were dominated by limonene and β-pinene in S. greggii and by 1,8-cineole in S. blepharophylla. Two potential (non-bird) pollinators were especially abundant: small bees belonging to the genus Lasioglossum and large bees belonging to the species Xylocopa violacea. Our study highlights the plasticity of these plants, as well as tools that can be conveniently used to establish novel interactions

    Flower selection of Xylocopa violacea: aromatic and ornamental plants as resources in a botanic garden

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    We assessed the interactions between aromatic and ornamentals plants and local pollinators in a botanic garden. We focused our attention on a frequent solitary bee, Xylocopa violacea, that thanks to its large size and its feeding preferences can visit many types of flowers. By conducting linear walking transects, we recorded all flower visits by bees, highlighting those of X. violacea. We analysed bee preferences in terms of plant family, plant origin or flower morphology. We also identified plant species that were visited by X. violacea together with other foraging bees. Results indicated that X. violacea selectively visits flowering plant species at the botanic garden, preferring Lamiaceae and bilabiate flower types on which legitimate or illegitimate visits can be performed. Other bee species do concurrently visit the same plants, and in the future studies on competition, resource exploitation and pollination success will be addressed

    The medial septum is insulin resistant in the AD presymptomatic phase: rescue by nerve growth factor-driven IRS1 activation.

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    Basal forebrain cholinergic neurons (BFCN) are key modulators of learning and memory and are high energy-demanding neurons. Impaired neuronal metabolism and reduced insulin signaling, known as insulin resistance, has been reported in the early phase of Alzheimer's disease (AD), which has been suggested to be "Type 3 Diabetes." We hypothesized that BFCN may develop insulin resistance and their consequent failure represents one of the earliest event in AD. We found that a condition reminiscent of insulin resistance occurs in the medial septum of 3 months old 3 7Tg-AD mice, reported to develop typical AD histopathology and cognitive deficits in adulthood. Further, we obtained insulin resistant BFCN by culturing them with high insulin concentrations. By means of these paradigms, we observed that nerve growth factor (NGF) reduces insulin resistance in vitro and in vivo. NGF activates the insulin receptor substrate 1 (IRS1) and rescues c-Fos expression and glucose metabolism. This effect involves binding of activated IRS1 to the NGF receptor TrkA, and is lost in presence of the specific IRS inhibitor NT157. Overall, our findings indicate that, in a well-established animal model of AD, the medial septum develops insulin resistance several months before it is detectable in the neocortex and hippocampus. Remarkably, NGF counteracts molecular alterations downstream of insulin-resistant receptor and its nasal administration restores insulin signaling in 3 7Tg-AD mice by TrkA/IRS1 activation. The cross-talk between NGF and insulin pathways downstream the insulin receptor suggests novel potential therapeutic targets to slow cognitive decline in AD and diabetes-related brain insulin resistance

    Lithium therapy and weight change in people with bipolar disorder: A systematic review and meta-analysis

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    Lithium remains the gold standard maintenance treatment for Bipolar Disorder (BD). However, weight gain is a side effect of increasing relevance due to its metabolic implications. We conducted a systematic review and metaanalysis aimed at summarizing evidence on the use of lithium and weight change in BD. We followed the PRISMA methodology, searching Pubmed, Scopus and Web of Science. From 1003 screened references, 20 studies were included in the systematic review and 9 included in the meta-analysis. In line with the studies included in the systematic review, the meta-analysis revealed that weight gain with lithium was not significant, noting a weight increase of 0.462 Kg (p = 0158). A shorter duration of treatment was significantly associated with more weight gain. Compared to placebo, there were no significant differences in weight gain. Weight gain was significantly lower with lithium than with active comparators. This work reveals a low impact of lithium on weight change, especially compared to some of the most widely used active comparators. Our results could impact clinical decisions
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