1,242 research outputs found
Pathogenesis of polymyalgia rheumatica
Polymyalgia rheumatica (PMR) is a chronic, inflammatory disorder of unknown cause, almost exclusively occurring in people aged over 50 and often associated with giant cell arteritis. The evidence that PMR occurs almost exclusively in individuals aged over 50 may indicate that age-related immune alterations in genetically predisposed subjects contribute to development of the disease. Several infectious agents have been investigated as possible triggers of PMR even though the results are inconclusive. Activation of the innate and adaptive immune systems has been proved in PMR patients as demonstrated by the activation of dendritic cells and monocytes/macrophages and the altered balance between Th17 and Treg cells. Disturbed B cell distribution and function have been also demonstrated in PMR patients suggesting a pathogenesis more complex than previously imagined. In this review we will discuss the recent findings regarding the pathogenesis of PMR
Histopathology of the gut in rheumatic diseases
The gastrointestinal tract regulates the trafficking of macromolecules between the environment and the host through an epithelial barrier mechanism and is an important part of the immune system controlling the equilibrium between tolerance and immunity to non-self-antigens. Various evidence indicates that intestinal inflammation occurs in patients with rheumatic diseases. In many rheumatic diseases intestinal inflammation appears to be linked to dysbiosis and possibly represents the common denominator in the pathogenesis of different rheumatic diseases. The continuative interaction between dysbiosis and the intestinal immune system may lead to the aberrant activation of immune cells that can re-circulate from the gut to the sites of extraintestinal inflammation as observed in patients with ankylosing spondylitis. The exact contribution of genetic factors in the development of intestinal inflammation in rheumatic diseases needs to be clarified
Toward the valorization of olive (Olea europaea var. europaea L.) biodiversity: horticultural performance of seven Sicilian cultivars in a hedgerow planting system
An intense survey of the Sicilian's olive growing areas for autochthonous germplasm, mainly represented by centennials olive trees (Olea europaea var. europaea L.) apparently older then III centuries, started at the beginning of the 1980s and resulted in the selection of more than 150 cultivars and accessions. This germplasm was propagated in a nursery, by grafting onto seedlings of Olea europaea L., and planted in an experimental orchard, in an olive district located in the South-west of the Island, where they were evaluated for over 30 years and selected for their early bearing, high and constant productivity, as well as high oil content of the fruits and excellent chemical (oleic acid and phenol content) and organoleptic profile of the oil. This paper reports data on the horticultural performances (production, vigor, crop efficiency and oil quality) of four cultivars (\u2018Kalat\u2019, \u2018Olivo di Mandanici\u2019, \u2018Abunara\u2019 and \u2018Minuta\u2019), selected within the Sicilian's autochthonous germplasm trained as 'Free Palmetta' and tested in a hedgerow planting system at three different planting densities: 500, 666 and 1000 trees ha-1. The cultivar \u2018Nocellara del Belice\u2019, \u2018Cerasuola, and \u2018Biancolilla\u2019, widely cultivated in the area where the trial was carried out, were used as references. The outstanding performance of the cultivar \u2018Kalat\u2019 at planting density of 1000 trees ha 121, suggests that this cultivar can be a promising choice for the super high density orchards (SHD). The other cultivars tested did not performed as \u2018Kalat\u2019 and seem not suitable for SHD planting system due to their high vigor. The hedgerow planting system tested, in the first 6 years of planting, increaseed productivity of all cultivars compared to traditional olive orchard typical of the area where the trial was conducted. This hedgerow olive orchard may represent a valid solution to increase orchard productivity and to reduce harvest costs by mechanization, depending on tree high, with straddle or side by side canopy contact machines. Achieve higher yield and reducing management costs using autochthonous, resilient cultivars, could be a new strategy to counteract climate changes. The unique organoleptic profiles of the oils obtained from the cultivars tested, could improve the offer of tasty, flavored and nutraceutical extra virgin olive oils in the international markets. Results highlight the importance of preserving and valorizing biodiversity to increase productivity and resiliency of agricultural systems, facing continuous, fast and deep social and environmental changes
EFFETTI DINAMICI DELL'INNALZAMENTO DEL CARICO PER ASSE DI ROTABILI FERROVIARI PER TRASPORTO MERCI
Lo sviluppo di un sistema di trasporto ferroviario merci richiede di minimizzare i tempi di percorrenza e massimizzare la capacità di carico dei convogli. Questo obiettivo può essere raggiunto mediante tre diverse strategie, che possono essere adottate separatamente o in modo congiunto. Le strategie consistono sostanzialmente nell'aumento della capacità di carico del singolo carro, nell'aumento della lunghezza del convoglio e nell'aumento della velocità del veicolo. La possibilità di attuare simultaneamente le tre strategie è possibile solo disponendo di infrastrutture dedicate e utilizzando una progettazione specifica della linea e dei veicoli. Il lavoro illustra gli effetti di un innalzamento del carico per asse, oltre al limite attualmente consentito in Italia, sui principali indicatori utilizzati dalla norma UIC per l'omologazione del materiale rotabile. Le valutazioni sono state effettuate utilizzando un tracciato reale di buona qualità ed un modello numerico di un veicolo di tipo Y2
Vaccinations in patients with inflammatory bowel disease.
Treatment of inflammatory bowel disease (IBD) frequently requires administration of immunosuppressive therapies, which increases susceptibility to a number of infectious pathogens. However, many infections can be prevented by correct and appropriate utilization of vaccinations. While several guidelines have been published on vaccination schedules in patients with IBD, vaccination rates remain suboptimal and even lower than those in the general population. This is due to many factors including poor awareness of the importance of vaccines by gastroenterologists and general practitioners as well as potential prejudices of patients regarding the safety and benefits of vaccines. With the aim of increasing awareness about the key role of immunization in the management of patients with IBD, the present review examines the existing literature relating to the main vaccinations and their application in these patients. We also summarize current evidence in order to provide clinicians with an easy source of reference for the principal recommendations for prevention of infectious diseases in patients with IBD. In addition, the recommendations about traveling for IBD patients are briefly explored. Lastly, since it is important for gastroenterologists to be aware of recommendations on vaccination, we recommend implementing educational programs to ensure compliance with current guidelines
In vitro evaluation of bacteriocinlike inhibitory substances produced by lactic acid bacteria isolated during traditional sicilian cheese making
Bacteriocins are antimicrobial proteins produced by bacteria that inhibit the growth of other bacteria with a bactericidal or bacteriostatic mode of action. Many lactic acid bacteria (LAB) produce a high diversity of different bacteriocins. Bacteriocinogenic LAB are generally recognised as safe (GRAS) and useful to control the frequent development of pathogens and spoilage microorganisms. For this reason they are commonly used as starter cultures in food fermentations. In this study, the authors describe the results of a screening on 699 LAB isolated from wooden vat surfaces, raw milk and traditional Sicilian cheeses, for the production of bacteriocin-like inhibitory substances, by comparing two alternative methods. The antagonistic activity of LAB and its proteinaceous nature were evaluated using the spot-on-thelawn and the well-diffusion assay (WDA) and the sensitivity to proteolytic (proteinase K, protease B and trypsin), amylolytic (a-amylase) and lipolytic (lipase) enzymes. The indicator strains used were: Listeria monocytogenes, Staphylococcus aureus, Escherichia coli, Salmonella enteritidis. A total of 223 strains (belonging to the species Enterococcus spp., Lactobacillus spp., Pediococcus spp., Streptococcus spp., Leuconostoc spp. and Lactococcus lactis) were found to inhibit the growth of Listeria monocytogenes by using the spot-on-the-lawn method; only 37 of these were confirmed by using the WDA. The direct addition of bacteriocin-producing cultures into dairy products can be a more practical and economic option for the improvement of the safety and quality of the final product
Bionics-based surgical training using 3D printed photopolymers and smart devices
Additive manufacturing technologies support the realization of surgical training devices using, typically, photopolymers-based materials. Unfortunately, the material jetting family, able to print a large range of soft and hard polymers, requires expensive machines and materials, which are not always available. On the other hand, vat polymerization fails in the resolution/volume ratio and in the mechanical properties reconstruction. Stereolithographic 3D printers, mostly used in dental surgery, make possible to realize cheap and sustainable models for training activity using only one material, reducing the possibility to obtain different mechanical characteristics. Moreover, the printed objects have to be treated (i.e. curing post-processing) in order to obtain the required performances, that could be preserved for long term storing. The aim of the proposed approach is to assure the surgeons' skills improvement through bionic-based surgical 3D printed models and smart devices, able to reproduce the same perception of a real surgical activity. We demonstrated how it is possible develop smart devices capable to take into account the same characteristics of different materials (i.e. bone and spongy bone) even if stored for a long time
BIAXIAL CURVATURE AND DUCTILITY CAPACITY OF RC COLUMN BASE CROSS SECTIONS
The deformation performance of the base cross sections of reinforced concrete buildings is
fundamental when large seismic events occur allowing the structure to have large excursions in
nonlinear field and guaranteeing an overall ductile behaviour.
It is well known that the axial force acting on columns significantly reduces the curvature capacity of
the sections and for this reason the technical codes give design criteria stating a limitation in order to
preserve the displacement capacity. It is also recognized that when biaxial bending occur the cross
section undergo a loss in strength capacity. Starting the study of from Bresler (1960), which provided
suitable expression to predict 3D limit interaction surfaces, several numerical and analytical models
were developed to take into account the biaxial interaction in strength.
Simultaneously it is noteworthy to point out that the presence of biaxial bending also influences the
deformation capacity of sections causing in most of the cases a relevant loss of the curvature and
ductility available with respect to the one owned along the principal axes. This important issue is not
faced by technical codes and not exhaustively treated in scientific literature as it was done for strength.
Moreover nonlinear structural models based on lumped plasticity do not take into account these
interaction aspects when defining plastic hinge properties in terms of curvature capacity.
The paper presents a numerical study in which the deformation capacity of RC cross sections
subjected to axial load and biaxial bending is investigated by means of a fiber discretization.
A procedure for the numerical definition of biaxial domains of ultimate curvature, yielding curvature
and curvature ductility is provided and the sensitivity of the biaxial deformation performance to some
geometrical and mechanical parameters (aspect ratio, concrete strength and confinement efficacy) is
discussed.The deformation performance of the base cross sections of reinforced concrete buildings is
fundamental when large seismic events occur allowing the structure to have large excursions in
nonlinear field and guaranteeing an overall ductile behaviour.
It is well known that the axial force acting on columns significantly reduces the curvature capacity of
the sections and for this reason the technical codes give design criteria stating a limitation in order to
preserve the displacement capacity. It is also recognized that when biaxial bending occur the cross
section undergo a loss in strength capacity. Starting the study of from Bresler (1960), which provided
suitable expression to predict 3D limit interaction surfaces, several numerical and analytical models
were developed to take into account the biaxial interaction in strength.
Simultaneously it is noteworthy to point out that the presence of biaxial bending also influences the
deformation capacity of sections causing in most of the cases a relevant loss of the curvature and
ductility available with respect to the one owned along the principal axes. This important issue is not
faced by technical codes and not exhaustively treated in scientific literature as it was done for strength.
Moreover nonlinear structural models based on lumped plasticity do not take into account these
interaction aspects when defining plastic hinge properties in terms of curvature capacity.
The paper presents a numerical study in which the deformation capacity of RC cross sections
subjected to axial load and biaxial bending is investigated by means of a fiber discretization.
A procedure for the numerical definition of biaxial domains of ultimate curvature, yielding curvature
and curvature ductility is provided and the sensitivity of the biaxial deformation performance to some
geometrical and mechanical parameters (aspect ratio, concrete strength and confinement efficacy) is
discussed
Processing of targets in smooth or apparent motion along the vertical in the human brain: an fMRI study
Neural substrates for processing constant speed visual motion have been extensively studied. Less is known about the brain activity patterns when the target speed changes continuously, for instance under the influence of gravity. Using functional MRI (fMRI), here we compared brain responses to accelerating/decelerating targets with the responses to constant speed targets. The target could move along the vertical under gravity (1g), under reversed gravity (-1g), or at constant speed (0g). In the first experiment, subjects observed targets moving in smooth motion and responded to a GO signal delivered at a random time after target arrival. As expected, we found that the timing of the motor responses did not depend significantly on the specific motion law. Therefore brain activity in the contrast between different motion laws was not related to motor timing responses. Average BOLD signals were significantly greater for 1g targets than either 0g or -1g targets in a distributed network including bilateral insulae, left lingual gyrus, and brain stem. Moreover, in these regions, the mean activity decreased monotonically from 1g to 0g and to -1g. In the second experiment, subjects intercepted 1g, 0g, and -1g targets either in smooth motion (RM) or in long-range apparent motion (LAM). We found that the sites in the right insula and left lingual gyrus, which were selectively engaged by 1g targets in the first experiment, were also significantly more active during 1g trials than during -1g trials both in RM and LAM. The activity in 0g trials was again intermediate between that in 1g trials and that in -1g trials. Therefore in these regions the global activity modulation with the law of vertical motion appears to hold for both RM and LAM. Instead, a region in the inferior parietal lobule showed a preference for visual gravitational motion only in LAM but not RM
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