5,433 research outputs found

    Psychological impact of carotid endarterectomy: a review of the studies.

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    Carotid Endarterectomy (CEA) is a surgical treatment validated to prevent cerebral ischemia, embolism and stroke in patients affected by severe stenosis of the carotid artery. A 1999 systematic review of the literature found controversial results about CEA influence on improvement of post-surgical cognitive performance. Moreover, few studies addressed the issue of the positive effects of CEA on quality of life and depression, reporting also controversial findings. The present review was aimed at considering the last 20 years studies focusing on the effects of CEA on the psychological dimensions. The purpose was to clarify the benefits, in terms of psychological well-being, offered by CEA, besides a reduction of the cardiovascular risk, as well as to have indication to lead further research in this area. Results of the 39 studies considered suggest that, although few studies show cognitive deterioration, most of them show stability with a tendency to improve both in cognitive functions and in other psychological areas. Further research is needed to clarify when it would be appropriate the use of CEA, the characteristics of eligible patients, and psychological as well as physical expected outcomes

    Lignin degradation efficiency of chemical pre-treatments on banana rachis destined to bioethanol production

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    Valuable biomass conversion processes are highly dependent on the use of effective pretreatments for lignocellulose degradation and enzymes for saccharification. Among the nowadays available treatments, chemical delignification represents a promising alternative to physical-mechanical treatments. Banana is one of the most important fruit crops around the world. After harvesting, it generates large amounts of rachis, a lignocellulosic residue, that could be used for second generation ethanol production, via saccharification and fermentation. In the present study, eight chemical pretreatments for lignin degradation (organosolv based on organic solvents, sodium hypochlorite, hypochlorous acid, hydrogen peroxide, alkaline hydrogen peroxide, and some combinations thereof) have been tested on banana rachis and the effects evaluated in terms of lignin removal, material losses, and chemical composition of pretreated material. Pretreatment based on lignin oxidation have demonstrated to reach the highest delignification yield, also in terms of monosaccharides recovery. In fact, all the delignified samples were then saccharified with enzymes (cellulase and beta-glucosidase) and hydrolysis efficiency was evaluated in terms of final sugars recovery before fermentation. Analysis of Fourier transform infrared spectra (FTIR) has been carried out on treated samples, in order to better understand the structural effects of delignification on lignocellulose. Active chlorine oxidations, hypochlorous acid in particular, were the best effective for lignin removal obtaining in the meanwhile the most promising cellulose-to-glucose conversion

    Quenching of the Haldane gap in LiVSi2O6 and related compounds

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    Abstract.: We report results of susceptibility χ and 7Li NMR measurements on LiVSi2O6. The temperature dependence of the magnetic susceptibility χ(T) exhibits a broad maximum, typical for low-dimensional magnetic systems. Quantitatively it is in agreement with the expectation for an S=1 spin chain, represented by the structural arrangement of V ions. The NMR results indicate antiferromagnetic ordering below TN=24 K. The intra- and interchain coupling J and Jp for LiVSi2O6, and also for its sister compounds LiVGe2O6, NaVSi2O6 and NaVGe2O6, are obtained via a modified random phase approximation which takes into account results of quantum Monte Carlo calculations. While Jp is almost constant across the series, J varies by a factor of 5, decreasing with increasing lattice constant along the chain direction. The comparison between experimental and theoretical susceptibility data suggests the presence of an easy-axis magnetic anisotropy, which explains the formation of an energy gap in the magnetic excitation spectrum below TN, indicated by the variation of the NMR spin-lattice relaxation rate at T≪T

    Multidimensional natal isotopic niches refect migratory patterns in birds

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    7openInternationalBothNaturally occurring stable isotope ratios in animal tissues allow estimation of species trophic position and ecological niche. Measuring multiple isotopes of migratory species along flyway bottlenecks offers the opportunity to sample multiple populations and species whose tissues carry information at continental scales. We measured δ2H, δ18O, δ13C, δ15N in juvenile feathers of 21 bird species captured at a migratory bottleneck in the Italian Alps. We examined if trends in individual isotopes reflected known migratory strategies and whether dietary (δ13C–δ15N) and spatially-explicit breeding origin (δ2H–δ18O) niche breadth (NB) differed among long-distance trans-Saharan (TS), short-distance (IP) and irruptive (IR) intra-Palearctic migrants, and whether they correlated with reported populations long-term trends. In both TS and IP groups, species δ2H declined with capture date, indicating that northern populations reached the stopover site later in the season, following a Type-I migration strategy. Values of δ2H indicated that breeding range of TS migrants extended farther north than IP and IR migrants. The breeding season was longer for IP migrants whose δ13C and δ15N values declined and increased, respectively, with time of capture. Average species dietary NB did not differ among migratory groups, but TS migrants displayed wider breeding origin niches, suggesting that long-distant migration is linked to broader ecological niches. Isotope origin NB well reflected species geographic range extent, while dietary NB did not correlate with literature accounts of species’ diet. We found no relationship between species breeding NB and population trends in Europe, suggesting that conditions in the breeding grounds, as inferred by stable isotopes, are not the only determinant of species’ long-term persistence. We demonstrate that ringing activities and isotopic measurements of passerines migrating through a bottleneck represents a unique opportunity to investigate large-scale life-history phenomena relevant to conservation.openFranzoi, A.; Larsen, S.; Franceschi, P.; Hobson, K. A.; Pedrini, P.; Camin, F.; Bontempo, L.Franzoi, A.; Larsen, S.; Franceschi, P.; Hobson, K.A.; Pedrini, P.; Camin, F.; Bontempo, L

    Practical indications for the prevention and management of SARS-CoV-2 in ambulatory dialysis patients : lessons from the first phase of the epidemics in Lombardy

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    Confronting the SARS-CoV-2 outbreak has allowed us to appreciate how efficiently highly-resourced settings can respond to crises. However even such settings are not prepared to deal with the situation, and lessons are only slowly being learnt. There is still an urgent need to accelerate protocols that lead to the implementation of rapid point-of-care diagnostic testing and effective antiviral therapies. In some high-risk populations, such as dialysis patients, where several individuals are treated at the same time in a limited space and overcrowded areas, our objective must be to ensure protection to patients, the healthcare team and the dialysis ward. The difficult Italian experience may help other countries to face the challenges. The experience of the Lombardy underlines the need for gathering and sharing our data to increase our knowledge and support common, initially experience-based, and as soon as possible evidence-based position to face this overwhelming crisis
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