6,456 research outputs found
Psychological impact of carotid endarterectomy: a review of the studies.
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
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
Brain Neprilysin Activity and Susceptibility to Transgene-Induced Alzheimer Amyloids
Neprilysin (NEP) is a zinc metalloproteinase that degrades enkephalins, endothelins, and the Alzheimer’s disease amyloid ß (Aß) peptides. NEP-deficient mice possess increased levels of brain Aß1-40 and Aß1-42. The objective of this study was to determine whether tissue NEP specific activity differs according to age and/or across mouse strains, especially those strains predisposed toward formation of Aß-amyloid plaques following overexpression of the human Alzheimer amyloid precursor protein (APP). The C57Bl/6J mouse strain appears to be relatively susceptible to cerebral amyloidosis, whereas the Swiss Webster (SW) strain appears more resistant. We investigated whether NEP specific activity in brain and kidney homogenates from SW and C57 mice of 6, 40, and 80 weeks old varied according to mouse strain, age, and gender. Among the variables tested, NEP specific activity varied most dramatically across mouse strain, with the kidney and brain of SW mice displaying the highest activities. Aging was associated with a reduction in brain NEP specific activity in both trains. Gender-specific differences were identified in kidney but not in brain. We conclude that aging- and strain-dependent ifferences in NEP specific activity may play a role in the differential susceptibility of some mouse strains for developing cerebral amyloidosis following human APP overexpression
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