145 research outputs found

    Modelling of photonic wire Bragg Gratings

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    Some important properties of photonic wire Bragg grating structures have been investigate. The design, obtained as a generalisation of the full-width gap grating, has been modelled using 3D finite-difference time-domain simulations. Different types of stop-band have been observed. The impact of the grating geometry on the lowest order (longest wavelength) stop-band has been investigated - and has identified deeply indented configurations where reduction of the stop-bandwidth and of the reflectivity occurred. Our computational results have been substantially validated by an experimental demonstration of the fundamental stop-band of photonic wire Bragg gratings fabricated on silicon-on-insulator material. The accuracy of two distinct 2D computational models based on the effective index method has also been studied - because of their inherently much greater rapidity and consequent utility for approximate initial designs. A 2D plan-view model has been found to reproduce a large part of the essential features of the spectral response of full 3D models

    The use of the Borg Rating of perceived exertion scale in cardiopulmonary resuscitation

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    Cardiorespiratory arrest is a critical event whose survival rate is related to the quality of resuscitation manoeuvres, combined with technology. It is important to understand the perception of tiredness during this procedure, aiming at the effectiveness of compressions and increasing the chances of survival. Goal Apply the Borg Scale to analyze the effort perceived by nurses during cardiopulmonary resuscitation manoeuvres with a feedback device. Method Experimental study with randomized distribution of nurses in a teaching hospital, simulating cardiac arrest, to assess perceived exertion using the Borg scale during cardiopulmonary resuscitation with/without a feedback device. A statistical significance level of 5% was adopted. Results Sixty-nine nurses working in critical and non-critical adult care units were included. Perceived exertion and heart rate were lower in the intervention group (p<0.001), influenced by the feedback device, with no significant difference regarding the actuation units. Conclusion The Borg scale proved to be adequate for the proposed objectives. The feedback device contributed to less effort and reduced heart rate during resuscitation manoeuvres. The low cost and ease of application favour its use in training and real-time consultations to assess performance during resuscitation, using a feedback device to reduce efforts and the perception of tiredness. It also allows reflection on the intervening factors and resources that can influence the quality of care and the chances of survival

    Polyphenols journey through blood-brain barrier towards neuronal protection

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    Age-related complications such as neurodegenerative disorders are increasing and remain cureless. The possibility of altering the progression or the development of these multifactorial diseases through diet is an emerging and attractive approach with increasing experimental support. We examined the potential of known bioavailable phenolic sulfates, arising from colonic metabolism of berries, to infuence hallmarks of neurodegenerative processes. In silico predictions and in vitro transport studies across blood-brain barrier (BBB) endothelial cells, at circulating concentrations, provided evidence for diferential transport, likely related to chemical structure. Moreover, endothelial metabolism of these phenolic sulfates produced a plethora of novel chemical entities with further potential bioactivies. Pre-conditioning with phenolic sulfates improved cellular responses to oxidative, excitotoxicity and infammatory injuries and this attenuation of neuroinfammation was achieved via modulation of NF-κB pathway. Our results support the hypothesis that these small molecules, derived from dietary (poly)phenols may cross the BBB, reach brain cells, modulate microglia-mediated infammation and exert neuroprotective efects, with potential for alleviation of neurodegenerative diseases.info:eu-repo/semantics/publishedVersio

    Phyllosticta citricarpa and sister species of global importance to Citrus.

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    Several Phyllosticta species are known as pathogens of Citrus spp., and are responsible for various disease symptoms including leaf and fruit spots. One of the most important species is P. citricarpa, which causes a foliar and fruit disease called citrus black spot. The Phyllosticta species occurring on citrus can most effectively be distinguished from P. citricarpa by means of multilocus DNA sequence data. Recent studies also demonstrated P. citricarpa to be heterothallic, and reported successful mating in the laboratory. Since the domestication of citrus, different clones of P. citricarpa have escaped Asia to other continents via trade routes, with obvious disease management consequences. This pathogen profile represents a comprehensive literature review of this pathogen and allied taxa associated with citrus, focusing on identification, distribution, genomics, epidemiology and disease management. This review also considers the knowledge emerging from seven genomes of Phyllosticta spp., demonstrating unknown aspects of these species, including their mating behaviour.TaxonomyPhyllosticta citricarpa (McAlpine) Aa, 1973. Kingdom Fungi, Phylum Ascomycota, Class Dothideomycetes, Order Botryosphaeriales, Family Phyllostictaceae, Genus Phyllosticta, Species citricarpa.Host rangeConfirmed on more than 12 Citrus species, Phyllosticta citricarpa has only been found on plant species in the Rutaceae.Disease symptomsP. citricarpa causes diverse symptoms such as hard spot, virulent spot, false melanose and freckle spot on fruit, and necrotic lesions on leaves and twigs.Useful websitesDOE Joint Genome Institute MycoCosm portals for the Phyllosticta capitalensis (https://genome.jgi.doe.gov/Phycap1), P. citriasiana (https://genome.jgi.doe.gov/Phycit1), P. citribraziliensis (https://genome.jgi.doe.gov/Phcit1), P. citrichinaensis (https://genome.jgi.doe.gov/Phcitr1), P. citricarpa (https://genome.jgi.doe.gov/Phycitr1, https://genome.jgi.doe.gov/Phycpc1), P. paracitricarpa (https://genome.jgi.doe.gov/Phy27169) genomes. All available Phyllosticta genomes on MycoCosm can be viewed at https://genome.jgi.doe.gov/Phyllosticta
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