Alterazioni cromatiche di materiali lapidei carbonatici: studio delle macchie indotte dalla coesistenza con materiali ferrosi e metodi innovativi per la loro rimozione

Carbonatic stones artifacts, especially those in outdoor environments, undergo chemical, physical, biological and anthropic degradation or at least alteration. A remarkable aesthetic impact rises from the presence of stains based on metal compounds that can be attributed to extrinsic (metal-stone contact) or intrinsic (oxidation of iron minerals in the stone) factors. The iron staining, especially on light-colored stone, is generally considered to be one of the most difficult problem encountered in the cleaning of porous building materials. Here we present a research starting with a preliminary chemical and morphological characterisation of iron based stains, on carrara marble and travertine, and ending with a cleaning procedure by innovative chemical and biological treatments. We used several analytical methods on both ancient artefacts and simulated samples, in order to individuate the iron compounds that are more frequently found. A natural staining was chosen, i.e. the exposition of marble and travertine in contact with iron on a terrace. The most efficient chemical and biological solution were individuated and optimize

A multidisciplinary diagnostic approach preliminary to the restoration of the country church "San Maurizio" located in Ittiri (SS), Italy

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A green approach to clean iron stains from marble surfaces

AbstractIn the field of cultural heritage restoration, the removal of iron corrosion stains is a difficult problem to deal with, especially in stone materials. Many studies in recent years have been aimed at finding simple and reliable methods using non-toxic chelating compounds. The search for natural non-toxic compounds is therefore of great relevance, especially in the conservation of cultural heritage, where the use of toxic chemical compounds often involves risks for the environment and human health. Following this trend, the purpose of this preliminary work was to verify the use of two proteins, Lactotransferrin (Ltf) and Ovotransferrin (Ovt), for the removal of iron-based stains on marble surfaces. The two proteins, whose high affinity for iron "in vivo" has been widely documented, were extracted from their natural matrices. The protein extracts were then immobilized using a common cellulose pulp. The poultices obtained were spread on the surfaces of artificially stained marble specimens and, after a set time, were easily removed. The effectiveness of the removal, visually evident, was detected by spectrocolorimetry and image analysis. The surface analyses, before and after the treatment, carried out by X-ray photoelectron spectroscopy (XPS), confirmed that both proteins have a selective and effective complexing capacity for the ferric ions of rust stains

The Neolithic site “La Marmotta”. DNA metabarcoding to identify the microbial deterioration of waterlogged archeological wood

Introduction: The evaluation of biological degradation of waterlogged archeological wood is crucial to choose the conservative and protective treatments to be applied to the wooden material. The waterlogged environmental conditions are characterized by oxygen scarcity, only allowing the growth of adapted microbes capable to degrade the organic wooden material, mainly erosion bacteria and softrot fungi. In this work, we characterized and evaluated the biodegradation state and the microbial communities of wooden fragments preserved in storage tanks. These were preserved by waterlogging within the Neolithic village “La Marmotta,” currently found under the Bracciano Lake (Lazio, Italy). Methods: The waterlogged wood samples were first identified taxonomically with an optical microscope, also allowing an evaluation of their preservation state. The microbial community was then evaluated through the sequencing of Internal Transcribed Spacer sequences for fungi and 16S for bacteria with the Oxford Nanopore Technologies (ONT) MinION platform. Results: The identified microbial community appears to be consistent with the waterlogged samples, as many bacteria attributable to the erosion of wood and ligninolytic fungi have been sequenced. Discussion: The reported results highlight the first use of targeted metabarcoding by ONT applied to study the biodeterioration of waterlogged archeological wood

The importance of Cone-Beam computed tomography in diagnosis of associated mandibular osteonecrosis: case report / A importância da TCFC no diagnóstico e prognóstico da osteonecrose mandibular associada aos bisfosfonatos: relato de caso clínico

The Cone-Beam Computed Tomography (CBCT) is very useful in diagnosis and treatment planning, as well as in the prognosis of osteonecrosis of the jaws. This study reports a clinical case of Bisphosphonate-Associated Mandibular Osteonecrosis from the perspective of CBCT. The patient, female, 83 years old, presented painful symptoms in the posterior region of the right mandible and reported Bisphosphonate medication for more than five years to treat osteoporosis and osteopenia. Based on clinical and CBCT imaging characteristics, the patient was diagnosed with Bisphosphonate-Associated Mandibular Osteonecrosis. Initially, the treatment consisted of oral antibiotic therapy, pain control, hyperbaric oxygenation and oral hygiene (mouthwashes). After 11 months of clinical therapy, CBCT revealed bone reconstruction of the buccal cortex, but also a hypodense imaging in the lingual cortex compatible with bone lysis and bone sequestration. The patient was referred for bone debridement and sequestrectomy. The histopathological diagnosis consisted of osteonecrosis with secondary acute osteomyelitis. After 60 days of the surgical procedure and hyperbaric sessions/systemic antibiotic therapy, an oral healthy mucosa in the region of the right mandibular body was evidenced in the intraoral examination. Cortical bone regeneration was observed on CBCT. Concluded that the use of CBCT, in this case report, makes it possible to estimate the extent of the lesion and the post-treatment outcome, assessing bone density, the presence of bone sequestration and the involvement of the involved areas. In fact, early diagnosis is essential for the success of the therapeutic approach

Ancient coins: cluster analysis applied to find a correlation between corrosion process and burial soil characteristics

Although it is well known that any material degrades faster when exposed to an aggressive environment as well as that "aggressive" cannot be univocally defined as depending also on the chemical-physical characteristics of material, few researches on the identification of the most significant parameters influencing the corrosion of metallic object are available

Copernicus Ocean State Report, issue 6

The 6th issue of the Copernicus OSR incorporates a large range of topics for the blue, white and green ocean for all European regional seas, and the global ocean over 1993–2020 with a special focus on 2020