Geochemical, mineral-petrographic and physical-mechanical characterization of stones and mortars from the Romanesque Saccargia Basilica (Sardinia, Italy) to define their origin and alteration

This paper aims to study the geomaterials of the most important Romanesque-style monument of Sardinia, the Santissima Trinità di Saccargia Basilica (Codrongianos, north Sardinia). The monument was built up on ruins of a pre-existing monastery, and completed in 1116 A.D. Over time, the aspect of the monument is quite changed due to two series of restoration works. The stone materials consist of both grey-black basalts and whitish limestones and marls, intentionally used to give a bichromy effect of the construction. The volcanic rocks belong to the Miocene-Pleistocene volcanic Sardinian activity, while limestones and marls belong to the sedimentary marine Miocene Formation of Meilogu (Logudoro). To define both the origin and the alteration processes of materials, geochemical, petrographic and physical-mechanical investigations of volcanic and sedimentary rocks were carried out on samples collected from monument and possible source outcrops. The integrated chemical (ICP-MS) and petrographic data allowed to ascertain the sourcing sites of raw materials. Moreover, physical-mechanical tests along with X-Ray Diffraction (XRPD) analysis, highlighted the main weathering processes responsible of the chemical-physical alteration affecting the geomaterials, and the newly-formed mineral phases formed on stone surface

Pyroclastic Stones as Building Materials in Medieval Romanesque Architecture of Sardinia (Italy): Chemical-Physical Features of Rocks and Associated Alterations

The paper discusses the chemical-physical-petrographic features and decay processes of San Nicola Church (11th−14th century) building materials, one of the most representative Medieval Churches in Sardinia, stylistically attributable to the Romanesque architecture. The monument was built up into two stages and shows a characteristic size uniformity of the ashlars. The masonry is mainly made up of rhyodacitic pyroclastites belonging to the Sardinian Eocene-Miocene mag- matic phase (38–15 My). These volcanic rocks were widely used in Medieval architecture for the excellent workability, but its minero-petrographic features greatly favor the decay, due to the action of chemical-physical alteration processes. Although the alteration degree and macroscopic forms of decay vary from zone to zone in the monument, according to the different compositional features of the volcanic stones, weathering and exposure condition, the pyroclastic rocks are generally affected by greater alteration than other igneous lithotypes, due to their petrographic- volcanological characteristics (e.g., low-medium welding grade, medium-high porosity). The results concerning mineralogical and petrographic features, respectively, carried out by the application of X-Ray Powder Diffraction (XRPD), Optical Microscope (OM), and Scanning Electron Microscope (SEM) techniques, both on fresh building rocks and associated alterations, are here presented and discussed. Furthermore, the relationships between fresh pyroclastites and altera- tion processes affecting these rocks will be discussed

Chemical, mineralogical and ceramic properties of kaolinitic materials from the Tresnuraghes mining district (Western Sardinia, Italy)

Kaolinitic materials crop out in the Tresnuraghes mining district (Western Sardinia, Italy). Three main kaolinitic deposits, located in the Patalza, Salamura and Su Fongarazzu areas, respectively, were investigated in order to assess their potential in the ceramic industry. The parent rock-types of this raw material are the Oligocene-Miocene rhyolitic-rhyodacitic ignimbrites. Chemical and mineralogical analyses were performed on representative samples of each deposit, by XRD and XRF methodologies. The chemical analyses generally show high silica and low alumina contents in all samples, typical of weakly kaolinized materials. The main mineralogical association consists of kaolinite and cristobalite with quartz and smectite as the minor components. Alunite may be present as a main mineral in the Salamura and Su Fongarazzu deposits, making these clay materials unsuitable for ceramic applications. The Patalza deposit exhibits low iron and sulphur contents, but low plasticity and excessive refractoriness. The Patalza materials can be used as unconventional raw materials to replace both kaolin and silica in white-firing bodies. Results show that the introduction of the Patalza "kaolins" was well tolerated in bodies for tableware, wall and floor tiles, without significant changes in porosity, bulk density, pore size distribution and coefficient of thermal expansion. The main drawback of using the Patalza material is the slight increase of firing shrinkage, while the main advantage is a systematic increase in mechanical resistance

Geomaterials and decay forms of the coastal towers of Piscinni and Foghe, Weastern Sardinia

[EN] The distribution of Coastal Towers in Sardinia testify that foreign invasions, which occurred several times over the centuries, were particularly frequent and dangerous. The beginning of the eighth century signed an increase of the attacks from the sea. The most of Coastal Towers were built in the period of Spanish rule, from 1583 to 1720. Despite numerous restorations over the years, many of these defensive structures are in critical conditions, some also affected by structural collapse. The building materials are closely related to local geological outcrops, and consist of sedimentary, magmatic and metamorphic rocks. Study of different lithotypes allowed assessing the vulnerability of different materials in different environmental conditions. Salts, transported by aerosols and deposited inside the porous structures, are the principal cause of decay of the building materials. Chemical-physical and mineralogical-petrographic analyses, performed on some Towers allowed making some general assessments on their conservation status and restoration projects.Carcangiu, G.; Meloni, P.; Palomba, M.; Cocco, O.; Sitzia, F.; Murru, A.; Carboni, M.... (2015). Geomaterials and decay forms of the coastal towers of Piscinni and Foghe, Weastern Sardinia. En Defensive architecture of the mediterranean: XV to XVIII centuries. Vol. I. Editorial Universitat Politècnica de València. 345-352. https://doi.org/10.4995/FORTMED2015.2015.1753OCS34535

Percutaneous endoscopic jejunostomy (PEJ) in patients with dumping syndrome: Evaluation of our center on a series of clinical cases

Background: The Dumping syndrome occurs in a variable percentage of subjects undergoing surgery involving the esophageal and gastric district. The treatment makes use of the introduction of dietary measures and arti!cial nutrition, especially the internal one. This study evaluates the experience of a single center regarding the use of percutaneous endoscopic jejunostomy (PEJ) in patients developing the dumping syndrome. Methods: We evaluated the case history of our department, of all patients operated on at the level of the upper gastrointestinal tract, who had manifested symptoms referable to the Dumping syndrome in the postoperative period.We have identi!ed 3, which we have carried out further investigations to con!rm the presence of an accelerated gastric emptying, and given the poor results obtained with dietary modi!cations and drug therapy, we have implemented a feeding through enteral nutrition, through a jejunal probe. PEG/J positioned by Pull technique, and subsequently replaced after 8 months. Results: Clinically, patients did not develop short- or long-term complications, symptoms were signi!cantly reduced, and they gained weight. Psychologically, the anxiety disorders related to nutrition have improved. Conclusions: By means of percutaneous endoscopic jejunostomy, the symptoms related to hypoglycemic crises following the hyperinsulinemic response to the ingestion of carbohydrates in patients with Dumping were attenuated and the anxiety of eating was lessened. Although limited to a few cases, we believe this form of nutrition is the best for patients with dumping

Durability of repair mortars used in restoration of a Sardinian coastal tower: assessment after ten years

[EN] This study reports the results of investigations on conservation conditions of an ancient tower, called Torre del Pozzo, located in the S-W coast of Sardinia, restored about ten years ago. The tower suffers from serious problems related to vulnerability of building materials, particularly limestone and sandstones and aerial lime mortar with poor physical-mechanical properties. Over the centuries the materials were subjected to aggressive actions (wind corrasion and salt crystallization) causing an intense erosion of the walls with consequent partial collapse of the structure. About ten years ago a restoration involved the mortars and only the replacement and integration of ashlars deteriorated. After about 10 years from this intervention, some inspections have been carried out in order to assess the effectiveness of the intervention and the state of preservation of the tower. This paper focuses on analyses and tests carried out to assess condition and durability of the repair mortars.Meloni, P.; Carcangiu, G.; Palomba, M.; Enzo, S.; Carboni, M.; Cocco, O.; Casti, M.... (2015). Durability of repair mortars used in restoration of a Sardinian coastal tower: assessment after ten years. En Defensive architecture of the mediterranean: XV to XVIII centuries. Vol. II. Editorial Universitat Politècnica de València. 397-44. https://doi.org/10.4995/FORTMED2015.2015.1761OCS3974

Methodological approach in the conservation of coastal fortifications

[EN] The historical and artistic value of Coastal Towers justifies the recovery of these emblematic artifacts. For the achievement of this objective we propose a methodological approach including: i) architectural relief also by 3D laser scanner and collection of historical data; ii) macroscopic semi-quantitative evaluation of the decay, iii) application of diagnostic quantitative chemical-physical-mechanical methodologies, to assess the decay intensity, and define the criticalities for planning the restoration. The i step allows the graphic rendering of the building showing the geometry and the relationships between the parties. The ii step allows a preliminary understanding of the building materials, macroscopic alteration forms, monument features, acquisition of information about potential causes and decay mechanisms. During the iii step, sampling of building materials is planned. Laboratory analyses, to determine the soluble salts, crystalline phases, porosity as well as micro-textural features of the materials, are carried out by the application of suitable techniques.Carcangiu, G.; Columbu, S.; Meloni, P.; Carboni, M.; Casti, M.; Cocco, O.; Murru, A.... (2015). Methodological approach in the conservation of coastal fortifications. En Defensive architecture of the mediterranean: XV to XVIII centuries. Vol. I. Editorial Universitat Politècnica de València. 341-344. https://doi.org/10.4995/FORTMED2015.2015.1752OCS34134

Colorectal Cancer Stage at Diagnosis Before vs During the COVID-19 Pandemic in Italy

IMPORTANCE Delays in screening programs and the reluctance of patients to seek medical attention because of the outbreak of SARS-CoV-2 could be associated with the risk of more advanced colorectal cancers at diagnosis. OBJECTIVE To evaluate whether the SARS-CoV-2 pandemic was associated with more advanced oncologic stage and change in clinical presentation for patients with colorectal cancer. DESIGN, SETTING, AND PARTICIPANTS This retrospective, multicenter cohort study included all 17 938 adult patients who underwent surgery for colorectal cancer from March 1, 2020, to December 31, 2021 (pandemic period), and from January 1, 2018, to February 29, 2020 (prepandemic period), in 81 participating centers in Italy, including tertiary centers and community hospitals. Follow-up was 30 days from surgery. EXPOSURES Any type of surgical procedure for colorectal cancer, including explorative surgery, palliative procedures, and atypical or segmental resections. MAIN OUTCOMES AND MEASURES The primary outcome was advanced stage of colorectal cancer at diagnosis. Secondary outcomes were distant metastasis, T4 stage, aggressive biology (defined as cancer with at least 1 of the following characteristics: signet ring cells, mucinous tumor, budding, lymphovascular invasion, perineural invasion, and lymphangitis), stenotic lesion, emergency surgery, and palliative surgery. The independent association between the pandemic period and the outcomes was assessed using multivariate random-effects logistic regression, with hospital as the cluster variable. RESULTS A total of 17 938 patients (10 007 men [55.8%]; mean [SD] age, 70.6 [12.2] years) underwent surgery for colorectal cancer: 7796 (43.5%) during the pandemic period and 10 142 (56.5%) during the prepandemic period. Logistic regression indicated that the pandemic period was significantly associated with an increased rate of advanced-stage colorectal cancer (odds ratio [OR], 1.07; 95%CI, 1.01-1.13; P = .03), aggressive biology (OR, 1.32; 95%CI, 1.15-1.53; P < .001), and stenotic lesions (OR, 1.15; 95%CI, 1.01-1.31; P = .03). CONCLUSIONS AND RELEVANCE This cohort study suggests a significant association between the SARS-CoV-2 pandemic and the risk of a more advanced oncologic stage at diagnosis among patients undergoing surgery for colorectal cancer and might indicate a potential reduction of survival for these patients

Constraints from geochemistry and Sr–Nd isotopes for the origin of albitite deposits from Central Sardinia (Italy)

Major- and trace-element contents and Sr-Nd isotope ratios were determined in albitite, albitized and unaltered late-Variscan granitoid samples from the world-class Na-feldspar deposits of central Sardinia, Italy. The albite deposit of high economic grade has geological, textural, and chemical features typical of metasomatic alteration affecting the host granitoids. Albitization, locally accompanied by chloritization and epidotization, was characterized by strong leaching of Mg, Fe, K, and geochemically similar trace elements, and by a significant increase of Na. Ca, and P were moderately leached in the most metasomatized rocks. Other major (Si, Ti, Ca) and trace elements (U, Th, Y, and Zr), along with light (LREE) and middle (MREE) rare-earth elements, behaved essentially immobile at the deposit scale. The Nd-isotope ratios (0.512098 to 0.512248) do not provide information on the emplacement age of the unaltered late-Variscan granitoids. On the other hand, their Sr-isotope ratios fit an errorchron of 274 +/- 29 Ma (1-? error), in fair agreement with all published ages of Sardinian Variscan granitoids. The very low Rb content of albitized rocks precludes application of the Rb-Sr radiometric system to determine the age of albitization. The Sm-Nd system is not applicable either, because the 143Nd/144Nd ratios of albitized rocks and unaltered granitoids overlap. The overlap confirms that Sm and Nd were substantially immobile during albitization. On the other hand, the measured 87Sr/86Sr ratios of the albitized rocks are appreciably lower than those of the unaltered host granitoids, whereas, their initial Sr-isotope ratios are higher. This seems to suggest that a) albitization was induced by non-magmatic fluids rich in radiogenic Sr, and b) albitization occurred shortly after the granitoid emplacement. This conclusion is supported by Nd isotopes, because unaltered granitoids and albitites fit the same reference isochron at 274 Ma. The fluids acquired radiogenic Sr by circulation through the Lower Paleozoic metasedimentary basement. Specifically, it is estimated that Sr supplied by the non-carbonatic basement represents about 22 wt% of total Sr in albitite

Chemical-physical decay of volcanic stone from Santa Maria Church in Tergu (Anglona, Italy)

The Church of Santa Maria di Tergu is located by the Island’s Northern coast, the Gulf of Asinara, a short drive from Castelsardo, in the historical region of Anglona. At the Age of the Giudici the Church was the place of a Montecassino priory, mentioned in 1122 under the title of “Sancta Maria de Therco”. Situated over an area where recent archaeological excavations have revealed traces of a thriving late Byzantine domus, the Church features a single nave and a transept, a gabled front and a characteristic deep red bulk counterbalanced by the white arches and the white panels with black inlays in the façade wall surface. In post-Medieval times it was built a cover with a barrel vault (probably in the second half of the nineteenth century, as in many other similar cases dating the same moment) which caused severe static problems to the monument, since nobody had apparently considered the static requirements of the building and the load on the side walls, not large enough to support such a heavy load. The stone vault was later eliminated in favour of a new cover in wooden trusses. The Church was build using in duotone two main different stones: reddish volcanic stones and whitish limestones. The macroscopic and petrographic analysis showed that the volcanic rock are Oligo-Miocenic pyroclastites (i.e., rhyolites and rhyodacites). The volcanic stone show a petrographic affinity with samples coming from a local historic quarry, already mentioned in the restoration work documents of the 1940s. The limestone materials taken from the monument show a variable chemical-physical decay, due to dissolution and decohesion processes of the carbonate matrix. Also pyroclastic rocks show decay problems, consisting of chemical-mineralogical transformations on the outer stone surface, with devitrification of glassy groundmass and formation of secondary phases