182 research outputs found

    AN EXPEDITIOUS PARAMETRIC APPROACH FOR CITY INFORMATION MODELING AND FINITE ELEMENT ANALYSIS

    Get PDF
    Abstract. The mitigation of seismic risk passes through the assessment of seismic hazard of urban fabrics on a given territory. Statistical methods and damage probability matrices are currently used to facilitate seismic safety knowledge and assessment operations. These methods, despite being fast and low cost, often return results that differ from reality and prone to the expertise of the operator. Indeed, in order to have more accurate information it is necessary to conduct Finite Element Analysis (FEA). However, this type of analysis requires considerable surveying and modeling time and therefore are not easily applied to the urban scale. The key to implement this analysis at the territorial scale lies in the way of acquisition of urban data (geometric and informative) and their management within appropriate modeling environments that allow their treatment. Currently, the information modeling paradigms used for urban data collection and management are either time and resource consuming (HBIM) or overly simplified (GIS). In this research we investigate the potential of City Information Modeling (CIM) in a parametric environment (with reference to CityGML standards) combined with urban survey procedures. Aim of the work presented here is the definition of a parametric modeling protocol that allows, in a short time, the acquisition, modeling and finite element structural analysis of urban aggregates

    Sustainable solutions for removing aged wax-based coatings from cultural heritage. Exploiting hydrophobic deep eutectic solvents (DESs)

    Get PDF
    This study describes the investigation on the use of hydrophobic Deep Eutectic Solvents (DESs) for the removal of nonpolar coatings from works of art to replace toxic solvents. Beeswax and two microcrystalline waxes (R21 and Renaissances) have been selected as reference nonpolar coatings since they are commonly present in their aged state on metal and stone artifacts. The interaction between the DESs and three waxes has been evaluated through contact angle measurements, solubility tests, and cleaning tests carried out by implementing a method that is ordinarily used by restorers. Tests have been conducted on mockups consisting of microscope glass slides covered by wax. The effective removal of the wax-based coating from the mockups has been assessed through spectrocolorimetry and multispectral imaging under visible (VIS) and ultraviolet light (UV) at 365 nm by loading the waxes with a fluorescent marker (Rhodamine 6G). Fourier Transform Infrared (FT-IR) spectroscopy in the Attenuated Total Reflectance (ATR) mode was performed to assess the presence of both the wax and the solvent on the swabs used for the cleaning tests, confirming the actual interaction among the solvent and the solute. The experimental process proved DESs’ potential of being used as green solvents for cleaning treatments on Cultural Heritage

    Autopsy findings in COVID-19-related deaths. A literature review

    Get PDF
    Although many clinical reports have been published, little is known about the pathological post-mortem findings from people who have died of the novel coronavirus disease. The need for postmortem information is urgent to improve patient management of mild and severe illness, and treatment strategies. The present systematic review was carried out according to the Preferred Reporting Items for Systematic Review (PRISMA) standards. A systematic literature search and a critical review of the collected studies were conducted. An electronic search of PubMed, Science Direct Scopus, Google Scholar, and Excerpta Medica Database (EMBASE) from database inception to June 2020 was performed. We found 28 scientific papers; the total amount of cases is 341. The major histological feature in the lung is diffuse alveolar damage with hyaline membrane formation, alongside microthrombi in small pulmonary vessels. It appears that there is a high incidence of deep vein thrombosis and pulmonary embolism among COVID-19 decedents, suggesting endothelial involvement, but more studies are needed. A uniform COVID-19 post-mortem diagnostic protocol has not yet been developed. In a time in which international collaboration is essential, standardized diagnostic criteria are fundamental requirements

    Cytokine Storm in COVID-19: Immunopathogenesis and Therapy

    Get PDF
    A cytokine storm is a hyperinflammatory state secondary to the excessive production of cytokines by a deregulated immune system. It manifests clinically as an influenza-like syndrome, which can be complicated by multi-organ failure and coagulopathy, leading, in the most severe cases, even to death. The term cytokine storm was first used in 1993 to describe the graft-versus-host disease following allogeneic hematopoietic stem cell transplantation. It was then reused to define the adverse syndromes secondary to the administration of immunostimulating agents, such as anti-CD28 antibodies or bioengineered immune cells, i.e., CAR T-cell therapy. Currently, the concept of cytokine storm has been better elucidated and extended to the pathogenesis of many other conditions, such as sepsis, autoinflammatory disease, primary and secondary hemophagocytic lymphohistiocytosis, and multicentric Castleman disease. Moreover, cytokine storm has recently emerged as a key aspect in the novel Coronavirus disease 2019, as affected patients show high levels of several key pro-inflammatory cytokines, such as IL-1, IL-2, IL-6, TNF-α, IFN-γ, IP-10, GM-CSF, MCP-1, and IL-10, some of which also correlate with disease severity. Therefore, since the onset of the pandemic, numerous agents have been tested in the effort to mitigate the cytokine storm in COVID-19 patients, some of which are effective in reducing mortality, especially in critically ill patients, and are now becoming standards of care, such as glucocorticoids or some cytokine inhibitors. However, the challenge is still far from being met, and other therapeutic strategies are being tested in the hope that we can eventually overcome the disease

    Performance evaluation of a commercial protective coating through field-exposure tests on three stone substrates

    Get PDF
    In the last decades, there have been several studies on Cultural Heritage regarding the performance of protective and consolidating coatings for the prevention of decay. A coating must have several characteristics such as efficiency, breathability, and must be durable and reversible. In this research work, the performance of a commercial protective product (Fosbuild FBLE 200) was evaluated. This coating is composed of a TiO2 nanopowder dispersed in an aqueous solution of an acrylic polymer. The product, which exhibits depolluting, antimicrobial, water-repellent and self-cleaning properties, has been applied on three different lithotypes: Carrara marble, Noto stone, and Comiso stone. Field-exposure tests were carried out in two different outdoor environments (Catania and Palermo) in order to assess its suitability. Promising results were obtained for the Carrara marble after one year of exposure; however, a decrease in effectiveness was observed at the end of the second year

    Straighten your back! Self-correction posture and postural balance in 'non rehabilitative instructed' multiple sclerosis patients

    Get PDF
    BACKGROUD: Patients with MS, regardless of the complexity of the activity or sensory conditions, commonly present a significant postural control deficit compared to healthy subjects. OBJECTIVE: To investigate which postural self-correction strategies are adopted by patients with Multiple Sclerosis versus a group of healthy-subjects and how self-correction can influence the control of postural balance. METHODS: A case-control prospective observational study was conducted. Person with Multiple Sclerosis and a group of healthy volunteers were enrolled. Patients included were instructed with vocal commands, to reach a self-correction posture, and they were compared to healthy subjects. Clinical assessments including Balance, Stabilometry and Postural evaluation of the spine were performed. RESULTS: Sixty patients (30: control-group; 30: treatment-group) were enrolled. In the treatment group, the analysis reported a significant statistical difference between path length and center of pressure speed in self-correction posture with closed-eyes (p=0,049; 0,047) and an improvement in C7 and L3 levels in self-correction posture (p<0,01-C7; p<0,01-L3). There are significant statistical differences about path length between the two groups in all examined conditions (p=0,0001). At sagittal plane evaluation, results show an increase of all measurements in both posture (C7-neutral posture p=0,0001; L3-neutral posture p=0,0001; C7-self-correction posture p=0,0001; L3-self-correction posture p=0,0001). CONCLUSION: Further study should investigate dynamic situations and different Multiple Sclerosis forms to complete balance analysis and to establish a correct rehabilitative program with self-correction exercise as powerful focus

    Comparison of anti-transglutaminase ELISAs and an anti-endomysial antibody assay in the diagnosis of celiac disease: A prospective study

    Get PDF
    Background: Most studies of anti-transglutaminase (anti-tTG) assays have considered preselected groups of patients. This study compared the sensitivity, specificity, and predictive value of an immunofluorescence method for anti-endomysial antibodies (EmAs) and two anti-tTG ELISAs, one using guinea pig tTG (gp-tTG) and the other human tTG (h-tTG) as antigen, in consecutive patients investigated for suspected celiac disease (CD). Methods: We studied 207 consecutive patients (99 men, 108 women; age range, 17-84 years) who underwent intestinal biopsy for suspected CD. Patients presented with one or more of the following: weight loss, anemia, chronic diarrhea, abdominal pain, dyspepsia, alternating bowel habits, constipation, pain in the joints, and dermatitis. At entry to the study, an intestinal biopsy was performed and a serum sample was taken for IgA EmAs, anti-gp-tTG, and anti-h-tTG. Results: Intestinal histology showed that 24 patients had partial or total villous atrophy; in these patients the diagnosis of CD was confirmed by follow-up. The remaining 183 patients had villous/crypt ratios that were within our laboratory's reference values and were considered controls. Serum EmAs, anti-gp-tTG, and anti-h-tTG were positive in all 24 CD patients; in the control group, none were positive for serum EmAs, but 15 of 183 (8.2%) were positive for anti-gp-tTG, and 6 of 183 (3.3%) were positive for anti-h-tTG. Sensitivity was 100% for all assays, whereas specificity was 100% for the EmA, 92% for the anti-gp-tTG, and 97% for the anti-h-tTG assay. The negative predictive value was 100% for all assays; the positive predictive value was 100% for the EmA, 80% [95% confidence interval (CI), 65-95%] for the anti-h-tTG (P = 0.03 vs EmA) and 60% (95% CI, 44-76%) for the anti-gp-tTG assay (P = 0.0002 vs EmA). Areas (95% CIs) under the ROC curves were 0.987 (0.97-1.0) for anti-h-tTG and 0.965 (0.94-0.99) for anti-gp-tTG. Most of the patients testing false positive for anti-tTG had Crohn disease or chronic liver disease. Conclusions: Although both anti-tTG ELISAs showed optimum sensitivity, their lack of specificity yielded positive predictive values significantly lower than those for the EmA assay. © 2002 American Association for Clinical Chemistry

    Effects of different sources of air pollution on the carbonate stone surface of relevant European monuments

    Get PDF
    This contribution focuses on spectrometric analyses carried out on black crust samples, collected from buildings and churches belonging to the European built Heritage, i.e., the Corner Palace in Venice (Italy), the Cathedral of St. Rombouts in Mechelen (Belgium), the Church of St. Eustache in Paris (France) and the Tower of London (United Kingdom). Such monuments, all built in carbonate stones, were selected for their historic and artistic relevance, as well as for their location in different urban contexts (exposed to intense vehicular traffic or pedestrian areas). For a complete characterization of the black crusts, an approach integrating complementary techniques was used, including optical (OM) and scanning electron microscopy coupled with energy-dispersive X-ray spectrometry (SEM-EDS), Fourier transform infrared spectroscopy (FT-IR) and laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS). The complete characterization of the damage layers provided information on their chemical composition, the state of conservation of the underlying substrates and the interactions between crusts and stones. In particular, the geochemical study in terms of trace elements revealed that all crusts are enriched in heavy metals (As, Cd, Co, Cr, Cu, Fe, Mn, Mo, Ni, Pb, Sb, Sn, Ti, V, and Zn) compared to substrates. The different concentrations of such elements in all analyzed crust samples can be ascribed to several factors, such as: height of sampling, morphology of the sampled surfaces (vertical or horizontal), exposure to atmospheric agents, exposure to direct (road or boat traffic) or indirect (industries) sources of pollution, accumulation time of pollutants on the surfaces, wash out and particulate air pollution. Specifically, the crusts collected at lower heights (some samples of the Corner Palace, Cathedral of St. Rombouts and Tower of London) resulted to be mainly influenced by mobile sources of pollution (vehicular or boat traffic), while samples taken at higher heights (Church of St. Eustache and some samples of the Corner Palace) are generally mostly affected by stationary combustion sources. In some cases, the detailed analysis of multilayered crusts (Palazzo Corner) contributed to recognize the variation of combustion sources responsible for the deterioration of surfaces over time. In addition, the possibility of analyzing altered portions of the substrate (Tower of London) permitted to observe that some elements (Zn, Cu and Ni) show concentrations similar and, sometimes, higher than the overlying crusts. This result can be explained by the geochemical mobility of such elements (at specific environmental conditions), which accelerate the process of sulfating, rapidly creating new layers of crust In conclusion, the study of black crusts and altered substrates in terms of trace elements may provide information useful to understand the influence of the pollutants in the genesis of such degradation forms
    • …
    corecore