109 research outputs found
Mortar Characterization of Historical Masonry Damaged by Riverbank Failure: The Case of Lungarno Torrigiani (Florence)
The research of structural masonry associated with geo-hydrological hazards in Cultural Heritage is a multidisciplinary issue, requiring consideration of several aspects including the characterization of used materials. On 25 May 2016, loss of water from the subterranean pipes and of the aqueduct caused an Arno riverbank failure damaging a 100 m long portion of the historical embankment wall of Lungarno Torrigiani in Florence. The historical masonry was built from 1854–1855 by Giuseppe Poggi and represents a historical example of an engineering approach to riverbank construction, composed of a scarp massive wall on foundation piles, with a rubble masonry internal core. The failure event caused only a cusp-shaped deformation to the wall without any shattering or toppling. A complete characterization of the mortars was performed to identify the technologies, raw materials and state of conservation in order to understand why the wall has not collapsed. Indeed, the mortars utilized influenced the structural behavior of masonry, and their characterization was fundamental to improve the knowledge of mechanical properties of civil architectural heritage walls. Therefore, the aim of this research was to analyze the mortars from mineralogical–petrographic, physical and mechanical points of view, to evaluate the contribution of the materials to damage events. Moreover, the results of this study helped to identify compatible project solutions for the installation of hydraulically and statically functional structures to contain the riverbank
Monitoring and evaluation of sandstone decay adopting non-destructive techniques: On-site application on building stones
This paper focuses on the characterization approach to evaluate the decay state of Pietra Serena of historic buildings in Florence (Italy). Pietra Serena is a Florentine sandstone largely used in the city especially during the Renaissance; it is a symbol of cultural heritage of Florence and constitutes a large part of the city center, which was named a World Heritage Site by UNESCO in 1982. Unfortunately, many environmental factors negatively affect the stone, increasing damage and the danger of falling material. Any detachment of stone fragments, in addition to constitute a loss in cultural heritage, can be dangerous for citizens and the many tourists that visit the city. The use of non-destructive techniques (NDTs) as ultrasonic and Schmidt hammer tests can quantitatively define some mechanical properties and help to monitor the decay degree of building stone. In this study, the NDTs were combined with mineralogical, petrographical, chemical and physical analyses to investigate the stone materials, in order to correlate their features with the characteristics of the different artefacts in Pietra Serena. Correlations between the NDTs results and the compositional characteristics of the on-site stone were carried out; such discussion allows to identify zones of weakness and dangerous unstable elements
A Multidisciplinary Methodology for Technological Knowledge, Characterization and Diagnostics: Sandstone Facades in Florentine Architectural Heritage
The Historic Center of Florence, a UNESCO World Heritage Site, includes many examples of architecture characterized by rough-hewn rusticated block facades—a very common masonry technique in the Florentine Renaissance—made in Pietraforte sandstone. The latter features numerous criticalities related to its intrinsic characteristics and to decay phenomena that are due to weathering and pollution. A multidisciplinary methodology has been developed starting from historic analysis and architectural survey to a complete optometric, mechanical, physical, mineralogical, and petrographic characterization of rough-hewn rusticated blocks, applied to the case study of the Palazzo Medici Riccardi facades. The studies performed in this work cover several research fields, from architecture to geology, going through material diagnostics, and aim at improving knowledge and designing new restoration solutions for Pietraforte building-material criticalities. The research proposes an operative protocol aimed at supporting restoration projects and monitoring plans, with the aim to protect historical, architectural, and artistic cultural heritage and to safeguard the people who visit the city of Florence every year
A Multidisciplinary Methodology for Technological Knowledge, Characterization and Diagnostics: Sandstone Facades in Florentine Architectural Heritage
The Historic Center of Florence, a UNESCO World Heritage Site, includes many examples of architecture characterized by rough-hewn rusticated block facades—a very common masonry technique in the Florentine Renaissance—made in Pietraforte sandstone. The latter features numerous criticalities related to its intrinsic characteristics and to decay phenomena that are due to weathering and pollution. A multidisciplinary methodology has been developed starting from historic analysis and architectural survey to a complete optometric, mechanical, physical, mineralogical, and petrographic characterization of rough-hewn rusticated blocks, applied to the case study of the Palazzo Medici Riccardi facades. The studies performed in this work cover several research fields, from architecture to geology, going through material diagnostics, and aim at improving knowledge and designing new restoration solutions for Pietraforte building-material criticalities. The research proposes an operative protocol aimed at supporting restoration projects and monitoring plans, with the aim to protect historical, architectural, and artistic cultural heritage and to safeguard the people who visit the city of Florence every year
Fabry disease presenting with sudden hearing loss and otosclerosis : a case report
Introduction: Fabry disease is an X-linked lysosomal storage disorder resulting in a multiple-system disorder with a
wide spectrum of physical signs and symptoms, predominantly affecting the central and peripheral nervous
systems, skin, heart, kidneys, and eyes.
Case presentation: We describe the case of a 26-year-old European Caucasian man who had Fabry disease and
who presented with episodic sudden unilateral hearing loss and was treated with glucocorticoids, pentoxifylline,
hyperbaric oxygen, and fluoride because of concomitant audiometric evidence of otosclerosis. This case
demonstrates the partial and transient beneficial effect of standard treatment for sudden hearing loss not related
to Fabry disease and analyzes the possible connection between typical Fabry disease inner-ear lesions and
otosclerosis. Whereas hearing loss has been described in connection with Fabry disease, otosclerosis-associated
hearing loss in Fabry disease has not yet been described.
Conclusions: Although progressive hearing loss in patients with Fabry disease seems to be influenced by
replacement therapy, few data concerning treatment of sudden hearing loss are available. The lack of literature
concerning the pathogenesis of the otological involvement in Fabry disease makes it impossible to identify a
connection between the latter and otosclerosis. Therefore, this report may help to reinforce the importance of a
thorough evaluation of hearing in patients with Fabry disease and may be of help with therapeutic decisionmaking
Virtual inspection based on 3D survey supporting risks detachment analysis in Pietraforte stone built heritage
The paper presents the first results of a multidisciplinary research project launched to support the conservation and restoration of the stone façades of the Pitti Palace in Florence with innovative techniques from the fields of geomatics and diagnostic analysis. Monitoring campaigns are periodically conducted on the façades of the palace to identify stone elements in critical conditions; such surveys primarily require close and careful observation of the façade, for which a crane basket is required. The paper proposes first attempt to compare results obtained through a traditional workflow with those coming from a deeper use of the high-resolution 3D model to conduct a virtual inspection and to map elements of vulnerability on a GIS.
On a test area, the analysis of the factors considered relevant to the risk of detachment was carried out on the digital model and compared with what the experts observed on-site by carrying out Non-Destructive diagnostic tests. Traditionally conducted monitoring and diagnostic surveys are assumed to validate the proposed method, which, following a simple data analysis, remotely identifies all blocks detected as vulnerable by the in-situ inspection, potentially drastically reducing fieldwork. It is therefore proposed as a preliminary screening useful to better address further analysis
Application of a physically based model to forecast shallow landslides at a regional scale
<p>In this work, we apply a physically based model, namely the
HIRESSS (HIgh REsolution Slope Stability Simulator) model, to forecast the
occurrence of shallow landslides at the regional scale. HIRESSS is a physically
based distributed slope stability simulator for analyzing shallow landslide
triggering conditions during a rainfall event. The modeling software is made up of two
parts: hydrological and geotechnical. The hydrological model is based on an
analytical solution from an approximated form of the Richards equation, while
the geotechnical stability model is based on an infinite slope model that
takes the unsaturated soil condition into account. The test area is a portion
of the Aosta Valley region, located in the northwest of the Alpine mountain chain. The
geomorphology of the region is characterized by steep slopes with elevations
ranging from 400 m a.s.l. on the Dora Baltea River's floodplain to
4810 m a.s.l. at Mont Blanc. In the study area, the mean annual
precipitation is about 800–900 mm. These features make the territory
very prone to landslides, mainly shallow rapid landslides and rockfalls.
In order to apply the model and to increase its reliability, an in-depth
study of the geotechnical and hydrological properties of hillslopes
controlling shallow landslide formation was conducted. In particular, two
campaigns of on site measurements and laboratory experiments were performed
using 12 survey points. The data collected contributed to the generation of an input map
of parameters for the HIRESSS model. In order to consider the effect of
vegetation on slope stability, the soil reinforcement due to the presence of
roots was also taken into account; this was done based on vegetation maps and
literature values of root cohesion. The model was applied using back analysis
for two past events that affected the Aosta Valley region between 2008 and
2009, triggering several fast shallow landslides. The validation of the
results, carried out using a database of past landslides, provided good
results and a good prediction accuracy for the HIRESSS model from both a
temporal and spatial point of view.</p
Ipoacusia ricorrente improvvisa associata ad otosclerosi in giovane adulto con Malattia di Fabry
Presentiamo un caso clinico di ipoacusia monolaterale da coinvolgimento cocleovestibolare e otosclerosi in paziente con Malattia di Fabry. F.M., paziente di 26 anni (Malattia di Fabry diagnosticata a 9 anni, in terapia enzimatica sostitutiva dal 2001), presenta improvvisa comparsa di vertigini a regressione spontanea associate a persistente ipoacusia sinistra ed acufeni. L'esame della soglia uditiva evidenzia una soglia a destra di 40 dB SPL, a sinistra di 50 dB SPL. L'esame audiometrico evidenzia ipoacusia mista sinistra con una soglia di trasmissione della via aerea sui 40-50 dB Hl pantonale e della via ossea su frequenze medio-acute (3000-4000 Hz). Il timpanogramma risulta di tipo A. F.M. viene sottoposto a ciclo di ossigenoterapia iperbarica e terapia per os con glucocorticoidi, fluoruro di sodio e pentossifillina. L'audiometria a distanza di 1 mese evidenzia modesto miglioramento con persistenza di gap nella trasmissione tra via aerea e ossea. Dopo 3 mesi F.M. riferisce peggioramento della sintomatologia, esegue nuovo ciclo di ossigenoterapia iperbarica e terapia farmacologica. I BEAP'S evidenziano lieve sofferenza della via uditiva centrale sinistra. L'audiometria mostra nuovamente ipoacusia mista sinistra con soglia della via aerea sui 40-60 dB Hl con gap tra via aerea e via ossea e timpanogramma di tipo A-C. La TC, con studio della finestra ovale, ha mostrato quadro di iniziale otosclerosi. Il caso clinico presentato mostra gli effetti terapeutici, parziali e transitori, del trattamento standard dell'ipoacusia non correlata alla Malattia di Fabry e analizza le possibili correlazioni tra le tipiche lesioni a carico dell'orecchio interno nella Malattia di Fabry e l'otosclerosi. Il coinvolgimento cocleovestibolare nella Malattia di Fabry si manifesta nel 26% dei pazienti con ipoacusia neurosensoriale per le alte frequenze, tinnito e vertigini. Attualmente in letteratura non sono descritti casi di otosclerosi in pazienti con tale patologia
LONG-CHAIN POLYNSATURATED ACIDS PROFILE IN PLASMA PHOSPHOLIPIDS OF HYPERPHENYLALANINEMIC CHILDREN ON UNRESTRICTED DIET
Introduction
Hyperphenylalaninemia (HPA) is an autosomal recessive inborn error of metabolism, caused by a mutated gene of the hepatic enzyme phenylalanine hydroxylase (PAH; OMIM 261600), which converts the amino acid phenylalanine to other essential compounds in the body, such as tyrosine. The range of disease severity observed among patients with this form of HPA is mostly due to allelic heterogeneity at the PAH locus. Various combinations of mutations result in a spectrum of metabolic phenotypes ranging from phenylketonuria (PKU, blood Phe levels >360 micromol/L), which require dietary management, to mild hyperphenylalaninaemia (MHP, blood Phe levels ranging 120\u2013360 micromol/L) in which dietary restriction may be not necessary. PKU diet is similar to a vegetarian diet in that all animal-based foods and further some foods with high protein contents (cereals, bread, pasta and protein rich vegetables) must be avoided and replaced in part by low protein dietetic products. Therefore, children with PKU may have non adequate food supply of docosahexaenoic acid (DHA, 22:6n-3), except during infancy, when they may receive breast milk or infant formula preparations supplemented with DHA. The phenylketonuric (PKU) diet determines a low intake of long chain polyunsaturated fatty acids (LCPUFA), such as arachidonic acid (AA) and docosahexaenoic-acid (DHA), which are contained only in food of animal source. This lack of LCPUFA may be firstly explained by the inhibitory effect of phenylalanine and its metabolites on the endogenous synthesis of DHA and AA; it has been speculated, infact, that high plasma Phe levels, above the upper limit of 120 \u3bcmol/L, could impair the metabolic steps of LCPUFA synthesis. Therefore, PKU patients must rely only on the endogenous synthesis of LCPUFA from their precursors, the content of which also is often suboptimal in dietary products for patients with PKU, particularly that of \u3b1-linolenic acid (ALA), the precursor of DHA. In other words, \u201csuccessful\u201d dietary treatment of PKU appears to result in an iatrogenic decrease of the circulating DHA pools.
Aim of the study: The primary aim of the present study was to examine whether MHP children (on unrestricted dietary regimen) may exhibit a different plasma phospholipids LCPUFA profile from PKU children on a strict dietary control especially concerning DHA and AA, comparing them with an healthy reference population.
Patients and Methods: 45 MHP children (age 9-14 years) were age and sex matched with 45 PKU and 45 healthy control children and then admitted to the Department of Paediatrics, San Paolo Hospital, Milan, from July 2009 to July 2011 for routine examinations. Plasma phospholipds fatty acids were determined and expressed as % of total fatty acids. Inclusion criteria were as follows: age at recruitment 9-14 years, weight at birth > 2500 g, gestational age 37\u201342 week inclusive, singleton birth, having white parents. Children exhibiting diabetes mellitus and/or endocrine diseases, chronic liver diseases, overweight/obesity according to the International Obesity Task Force, and/or hyperlipidemia according to Italian guidelines, were excluded to prevent possible bias effects on plasma fatty acid status. PKU children non compliant with the recommended diet were also excluded. Compliance was evaluated according to age adjusted reference threshold values of plasma Phe. In all participating children fasting blood samples were taken in the morning at 8 h \ub1 30 min, within 3 days of recruitment. Fatty acid (FA) plasma levels were measured. In both HPA groups the FA analyses demonstrated reductions of long-chain polyunsaturated fatty acids (LCPUFA).
Results: MHP children showed phospholipds docosahexaenoic acid levels higher than PKU children (mean difference, 0.2%; 95% confidence interval, 0.02% to 0.38%), although difference was not significant after correction for multiple comparisons (P=0.117), and lower than healthy children (0.8%; -1.01% to -0.59%).
Conclusions: the results suggest that MHP children may exhibit a plasma phospholipds LCPUFA profile not appreciably differing from PKU children whereas show lower DHA levels than healthy children. While disadvantaged DHA levels of PKU may be mainly explained on the basis of the restricted dietary regimen, extra-dietary factors possibly connected with features of deranged metabolic pathways may play a role in hyperphenylalaninemic children. To clarify the possible role of hyperphenylalaninemia per se in determining the inhibition of LCPUFA synthesis, it appears interesting to examine plasma DHA levels in HPA children on unrestricted dietary regimen. In this study, MHP children showed levels of docosahexaenoic acid in plasma phospholipids around 12% higher than PKU children although difference was no significant after correction for multiple comparisons. All these results together suggest that independently of the dietary regimen, MHP children may exhibit DHA levels in plasma phospholipids not appreciably different from PKU children, but worse than in healthy subjects
GTAP and TiVA: Differences between the two databases and their Implications for Trade in Value-Added Indicators
- …