186,632 research outputs found
The Pietà di Ragusa panel: A science-based contribution to its dating by dendrochronology, wood anatomy and pigment analysis
No full textThis paper discusses the results of scientific investigations on a panel painting whose past attribution to Michelangelo has been recently taken again into account. The panel was investigated by means of dendrochronology, wood anatomy and pigment analysis. The wooden support is made of spruce and its last tree ring was dendrochronologically dated to 1497. Taking the time for wood working and seasoning into account, the terminus post quem for the creation of the painting is between 1525 and 1535. According to chemical analysis, the paint's binder is mainly egg tempera with some parts in fat tempera and finishings on the sky with azurite in glue tempera over a layer of smalt bound in fat tempera. These pigments are coherent with the expected period and help to date this panel. Obviously, we cannot confirm that Michelangelo himself painted the panel, but our results are coherent with his lifetime (1475–1564) and executive career. Our study contributes new science-based data to an on-going art historical debate. Aim The aim is to locate the chronological and geographical contexts by scientific analyses of the painted panel “Ragusa Pietà” under debate because of a possible attribution to Michelangelo who is believed to have painted it for Vittoria Colonna. © 2016 Elsevier Masson SA
La Storia Economica come Impegno. Saggi in onore di Angelo Moioli
No full textl volume raccoglie venti saggi di storia economica che altrettanti amici e colleghi di Angelo Moioli gli hanno voluto dedicare, per celebrare la sua lunga e impegnata carriera accademica, improntata sempre a una seria ricerca scientifica e a un’appassionata attività istituzionale. Lo spettro degli articoli offerti ripercorre l’ampia gamma dei suoi interessi scientifici, dall’organizzazione
dell’economia in antico regime alle dinamiche macro-economiche di lungo periodo, dai problemi della fiscalità alle soluzioni del credito cooperativo, dall’industria otto-novecentesca ai temi del lavoro e della società contemporanea, dai protagonisti del ceto imprenditoriale ad alcune figure centrali della politica economica italiana del ventesimo secolo
Amintore Fanfani tra spirito del capitalismo ed economia reale
No full textRiflessione sulla figura di Amintore Fanfani
Obsidian use in the mosaic of the St. Juvenal church, Narni (Italy): Chemical characterization and origin
No full textTesserae from the mosaic on the front of the San Giovenale chapel inside the Narni Cathedral were analyzed through non-destructive XRF analysis for the characterization of both colouring matters and opacifiers of the glass matrix. Subsequently, the concentration of the elements present at trace levels (μg g-1) was determined by means of Instrumental Neutron Activation Analysis (INAA) for comparisons with obsidians of known provenance and well-studied micro-elemental composition, in order to identify the geographical origin of the obsidian used in this Middle Ages mosaic. The main result is that the black tesserae were made with obsidian fragments coming from the Sardinia deposits (probably, Arci Mountain site C). © 2013 Avino et al.; licensee Chemistry Central Ltd
Gli statuti delle arti in età moderna tra norma e pratiche. Primi appunti del caso veneto
No full textNeonatal period: body composition changes in breast-fed full-term newborns
No full textBACKGROUND: Weight loss during initial days of life in healthy infants is known to consist of loss of both body solids and total body water. However, the nature of these body composition changes needs further investigation.
OBJECTIVE: To investigate the nature of changes in body composition that accompany weight loss during the first days of life in healthy term newborns.
METHODS: Body composition of healthy full-term newborns was assessed using air-displacement plethysmography. Cross-sectional (n = 262) and longitudinal samples (n = 28) were assessed during the first 4 and 5 days after delivery, respectively.
RESULTS: In the cross-sectional sample, mean body weight decreased significantly through day 4 (p < 0.001), mean fat mass (FM) and %FM decreased significantly (p = 0.005 and p = 0.031, respectively) by day 3. There was a significant decrease in mean fat-free mass on days 3 and 4 (p = 0.01 and p < 0.001, respectively). In the longitudinal sample, there was a significant decrease in mean body weight, FM and %FM (p < 0.001, p = 0.001, p = 0.013, respectively) by day 4. On day 5 there was a significant increase in mean body weight, FM and %FM (p < 0.001, p = 0.024, p = 0.036, respectively) when compared to day 4. There was no significant difference in mean FM and %FM values between day 1 and day 5.
CONCLUSIONS: These results indicate that body composition changes are constituted by a reduction in both fat and fat free mass. However, a greater %FM is lost and consequently regained by day 5 when compared to fat-free mass
PH effects in the acetaldehyde-ammonia reaction
No full textThe pH dependency of the reaction of acetaldehyde and ammonia to form the acetaldehyde-ammonia trimer has been studied in detail. The acetaldehyde-ammonia trimer is a molecule of interest in organic synthesis, since it can be used as a substrate in many reactions involving acetaldehyde or ammonia. This trimer is well known in the literature but no references are present so far to describe its formation from ammonia sources other than ammonium hydroxide. The focus of this study is on describing the course of reaction after addition of acetaldehyde to solutions of ammonia and various acids. Products have been analysed by means of 1H-NMR and IR spectroscopy and the complete range of pH values has been covered. Depending on the pH, two reaction regimes can be distinguished. At high pH, only the trimer is formed. In contrast, at low pH, only low quantities of the trimer are produced and the nature of the applied acid has a distinct effect on the reaction outcome. Inorganic acids result in low trimer concentration and high quantity of unreacted ammonia. Polymer formation dominates with simple carboxylic acids. Complex organic acids, such as e.g. maleic or nicotinic acid, lead to comparable quantities of the trimer and acetaldehyde. Based on our results, we propose some adjustments to the traditional reaction scheme developed for acetaldehyde-ammonia trimer formation at high pH
Le Storie di Ester di Paolo Veronese in San Sebastiano. Studio dei processi esecutivi attraverso la diagnostica per immagini
No full textStudio dei materiali e della tecnica esecutiva del ciclo di Ester di Paolo Veronese tramite radiografia RX e riflettografia IR multispettrale a scansione in occasione del restauro presso la soprintendenza di Venezi
Prognostic value of high-sensitive cardiac troponin I in asymptomatic chronic hemodialysis patients
No full textIntroduction: Increased levels of cardiac troponins (cTn) are a hallmark of acute myocardial infarction (AMI), along with symptoms and electrocardiographic (ECG) changes. Stably elevated cTn concentrations are frequently observed in asymptomatic patients with chronic kidney disease (CKD) and/or on hemodialysis (HD); the meaning of this elevation, as assessed by conventional techniques, remains unclear. Aim of our study was to evaluate the clinical significance of cTnI levels in asymptomatic HD patients by employing a newer high-sensitive cTnI (hs-cTnI) assay. Methods: We enrolled 49 patients undergoing regular HD treatment for more than 3 months; all patients were asymptomatic for chest pain and had no history of acute coronary syndrome in the past 2 months. For every patient we measured hs-cTnI, cTnI and brain natriuretic peptide (BNP) before initiation of one HD session at baseline (T0), after 3 (T1) and 9 months (T2). Demographic, anamnestic, dialytic and echocardiographic characteristics of the examined population were evaluated. We also recorded the number of cardiovascular events from T0 to 12 months after T2. Results: Fifteen patients were lost to follow-up: 6 died, 2 underwent kidney transplantation, 7 did not match the inclusion criteria later during observation. At T0 (49 patients) we observed 14 hs-cTnI positive patients vs. 4 standard c-TnI positive patients (28,5% vs 8,1%); at T1 (40 patients) 16 vs 3 (26.4% vs 7.5%); at T2 (34 pz) 9 vs 0 (26.4% vs 0%). During the study we recorded 10 cardiovascular events, 8 of which in patients that were hs-cTNI positive, leading to death in 3. Hs-cTnI levels were predictive of cardiovascular events at all times and predictive of cardiovascular mortality at T0 and T1 (p < 0.001). In a multivariate analysis, a history of coronary artery disease (CAD) was an independent variable of high hs-cTnI levels at T0 (p < 0.04) and T1 (p < 0.03). Conclusions: Our study shows that a novel sensitive assay detects more asymptomatic HD patients compared to previously used methods, being at the same time predictive of cardiovascular mortality and morbidity. The only independent variable of high hs-cTnI concentrations was a positive history of cardiovascular disease, suggesting a possible role of hs-cTnI in identifying a high-risk subset of patients
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