1,721,150 research outputs found
Ten years at the head of Padua’s Geriatric Department
Full text linkPresentation and commentary on the special issue of the journal Aging Clin Exp Res about Prof. Oreste Terranova who has been at the head of Padua Geriatric Department for ten years
PROVE DI INVECCHIAMENTO SU BIOCOMPOSITI EPOSSIDICI AD ELEVATE PERFORMANCE RINFORZATI CON FIBRE DI AGAVE
No full textLa riduzione dell'impatto ambientale nella moderna produzione di materiali compositi a matrice polimerica ha attratto una significativa attività di ricerca finalizzata alla messa a punto di nuovi materiali compositi “green” caratterizzati altresì da una apprezzabile riduzione dei costi e del peso specifico. Tra questi materiali giocano un ruolo importante i cosiddetti biocompositi, materiali costituiti da matrici a basso impatto ambientale o rinnovabili, rinforzate con fibre naturali. Nel presente lavoro, attraverso una sistematica campagna di prove sperimentali sono analizzati gli effetti dei principali agenti ambientali sulle proprietà meccaniche di biocompositi ad elevate prestazioni costituiti da una matrice epossidica green rinforzata con fibre di agave sisalana. Tramite laminazione manuale sono state realizzate tre tipologie di laminati biocompositi, con diverso lay-up (unidirezionale, cross-ply e quasi-isotropo, con percentuale in volume di fibre pari al 50%), che rappresentano in pratica i laminati di uso comune per applicazioni strutturali. Al fine di evidenziare i diversi effetti dell’invecchiamento su matrice e rinforzo, sono stati analizzati altresì provini costituiti dalla sola matrice epossidica. Tutti i materiali considerati sono stati sottoposti a un processo di invecchiamento accelerato, con condizioni controllate di temperatura, umidità e radiazioni UV, al fine di riprodurre le condizioni di esercizio associati, come avviene di solito, all’esposizione periodica alla luce solare (cicli di temperatura e UV), e all’umidità connessa a condizioni ambientali esterne (con possibile presenza di pioggia e rugiada). Sono state considerati in dettaglio gli effetti di degrado sulle caratteristiche meccaniche statiche e dinamiche. L’analisi dei risultati sperimentali è stata altresì finalizzata alla messa a punto di affidabili modelli che possano essere utilizzati per la previsione della evoluzione nel tempo delle proprietà meccaniche di tali interessanti materiali.The reduction of the environmental impact in the modern production of polymer matrix composite materials has attracted a significant research activity aimed to the development of new "green" composite materials characterized by an appreciable saving in terms of costs and specific weight. Among these materials, an important role is played by the so-called biocomposites, made by an ecofriendly matrix reinforced with natural fibers. In this work, the effects of the main environmental agents on the mechanical properties of high-performance biocomposites consisting of a green epoxy matrix reinforced by agave fibres, are analysed through a systematic experimental testing campaign. Three types of biocomposite laminates (unidirectional, cross-ply and quasi-isotropic with a Vf = 50%) that represent common laminates for structural applications, have been manufactured by hand lay-up and successive compression moulding. In order to highlight the different effects of ageing on matrix and reinforcement, samples consisting of simple epoxy matrix alone have been analysed too. All materials considered have been subjected to an accelerated ageing process with controlled temperature, humidity and UV radiation conditions, in order to reproduce the usual operating conditions associated with periodic exposure to sunlight (temperature and UV cycles) and humidity related to external environmental conditions (with possible presence of rain and dew). Detailed consideration has been given to the effects of degradation on static and dynamic mechanical properties. The analysis of the experimental results was also aimed to the developing of reliable models that can be used to predict the evolution of the mechanical properties of these interesting materials, over time
Influence of the anisotropy of sisal fibers on the mechanical properties of high performance unidirectional biocomposite lamina and micromechanical models
Full text linkHigh performance biocomposites reinforced by sisal fibers, are between the most promising materials that could
be used in various fields, from automotive to civil constructions, thanks to their good mechanical performance, as
well as to the low cost and the great availability of the fiber. Nevertheless, at present their practical use is
prevented by the limited knowledge of their mechanical performance. The results of the present study have
shown that the intimate fibrillar structure of the sisal fiber is associated with a high anisotropy involving not only
the elastic parameters, but also the damage processes with typical fiber splitting phenomena, that influence
noticeably the biocomposite strength under transversal tensile/compressive, longitudinal compressive and shear
loading. Also, they have permitted to implement new micromechanical models that can be used at the design
stage, in all practical structural applications where low cost green biocomposites reinforced by sisal long fiber
could be advantageously used
Discriminating between organic and psychological determinants of multiple chemical sensitivity: A case study
No full textAbstract
Multiple chemical sensitivity (MCS) is a controversial disorder characterized by a diverse set of debilitating symptoms purportedly induced by environmental chemicals. Many cases of putative MCS are believed to have a strong psychogenic component, making it difficult to differentiate between organic and psychogenic causes. In this case report we describe a procedure that can aid in this differentiation. A patient who met a strict set of criteria for MCS was tested on two test occasions. On the first, the patient was found to have no olfactory dysfunction, as determined from standardized olfactory tests. On the second, odorants, as well as a blank stimulus, were presented to the patient with instructions as to whether they were harmful or harmless. The patient's task was to estimate the intensity of each odorant and report any induced MCS-related symptoms. Potentially harmful odorants presented as harmless were judged significantly less intense, and triggered fewer symptoms, than harmless odorants presented as harmful. When an odorless stimulus was presented as harmful, the patient provided higher intensity evaluations and exhibited more symptoms than when it was presented as harmless. These phenomena were not present in three non-MCS controls. This straight-forward procedure allowed us to determine that the MCS symptoms of this patient were largely psychological and may be of general value for identifying psychogenic cases of MCS.Abstrac
ACCESSI LAPAROTOMICI E LAPAROSCOPICI
Full text linkTesto di studio di Chirurgia per corso di studi di Scienze Infermieristiche. Si descrive la tenica chirurgica degli accessi addominali
Analysis of suicide in the elderly in Italy. Risk factors and prevention of suicidal behavior
Full text linkThe authors describe the nationwide scale of suicides among the elderly in Italy for the period 1993-2010. The data are derived from the Italian Institute for Statistics (ISTAT) and the World Health Organization (WHO). The elderly turned out to represent the highest risk category for suicide, with risk increasing with age (sui- cide rates, per 100,000, in men aged 75 or over and aged 65-74 were respectively 28.3 and 15.7 in 2007). The rates for men were three times higher than those for women. The north-east and north-west regions of Italy had the highest rates of suicide in the elderly. Education was inversely related to the risk of suicide. Hanging was the most frequent method of suicide in men, and precipita- tion in women. The reasons for suicide, as inferred from available data, were predominantly mental-physical ill- nesses. The risk factors emerging from our analysis are discussed from the preventive point of view, in relation to the Italian situation and a review of the literature
Primary carcinoid tumor of the cystic and common bile ducts.
No full textWe report a case of primary carcinoid tumor arising at the confluence of the cystic and common bile ducts. The patient was a 64-year-old woman who developed a sudden onset of biliary colic and jaundice. Computerized tomography and nuclear magnetic resonance showed a mass lesion close to the head of the pancreas. At laparotomy a nodular lesion was found at the confluence of the cystic and common bile ducts. Microscopic observation revealed a type B-C carcinoid (Soga's classification) with positive immunoreactivity to chromogranin and cytokeratin. The presence of neurosecretory intracytoplasmic granules was demonstrated by electron microscopy. Flow cytometry showed diploid DNA content of the neoplastic cells with less than 5% of the nuclei in the S-phase region
Hernioplasty in Elderly High-Risk Adults: Efficacy of Fibrin Glue
Full text linkBackground:
Risk factors as cirrhosis, diabetes, coagulopathies, advanced age, have often been considered a contraindication to perform an inguinal hernioplasty. The aim of this study was to establish whether fibrin glue application to fix the mesh during a Lichtenstein inguinal hernioplasty is useful to prevent complications in high risk patients.
Methods:
From March 2004 to September 2009, 87 high risk patients underwent hernioplasty using fibrin glue to fix mesh prosthesis. Patients were evaluated for immediate and late postoperative pain, presence of haematomas and seromas, infiltration of ascitic fluid, and wound complications.
Results:
Among our patients (mean age 73.6±12.4 years) 38 (44%) had diabetes, 33 (38%) had coagulopathies and 16 (18%) had liver cirrhosis (2 C Child’s grade). During a follow-up period ranging from 12 to 24 months, no complications nor significant post-operative pain were observed.
Conclusions:
This preliminary observational study indicates that fibrin glue application can be considered a very useful way to obtain good results by open hernioplasty in high risk patients
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