1,133 research outputs found

    Coffee production: an occupational setting where exposure to mycotoxins need to be recognized and prevented

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    This project was supported by FCT/MCTES UIDP/05608/2020, and UIDB/05608/2020. This work is also supported by national funds through FCT/MCTES/FSE/UE, 2023.01366.BD; UI/BD/153746/2022 and CE3C unit UIDB/00329/2020; UI/BD/151431/2021; and Instituto Politécnico de Lisboa, national support through IPL/2022/InChildhealth/BI/12M; IPL/IDI&CA2023/FoodAIIEU_ESTeSL; IPL/IDI&CA2023/ASPRisk_ESTeSL; IPL/IDI&CA2023/ARAFSawmills_ESTeSL.Coffee production involves different processes until being available as a beverage involving several workers worldwide. Mycotoxin exposure may occur in this occupational setting since coffee beans are frequently contaminated with these fungal secondary metabolites due the crop infection by toxigenic fungi that commonly infect the plant during the various production stages. A study was developed in two milling industries located in Brazil aiming to evaluate workplace contamination with mycotoxins.info:eu-repo/semantics/publishedVersio

    Abnormal coactivation of knee and ankle extensors is related to changes in heteronymous spinal pathways after stroke

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    <p>Abstract</p> <p>Background</p> <p>Abnormal coactivation of leg extensors is often observed on the paretic side of stroke patients while they attempt to move. The mechanisms underlying this coactivation are not well understood. This study (1) compares the coactivation of leg extensors during static contractions in stroke and healthy individuals, and (2) assesses whether this coactivation is related to changes in intersegmental pathways between quadriceps and soleus (Sol) muscles after stroke.</p> <p>Methods</p> <p>Thirteen stroke patients and ten healthy individuals participated in the study. Levels of coactivation of knee extensors and ankle extensors were measured in sitting position, during two tasks: maximal isometric voluntary contractions in knee extension and in plantarflexion. The early facilitation and later inhibition of soleus voluntary EMG evoked by femoral nerve stimulation were assessed in the paretic leg of stroke participants and in one leg of healthy participants.</p> <p>Results</p> <p>Coactivation levels of ankle extensors (mean ± SEM: 56 ± 7% of Sol EMG max) and of knee extensors (52 ± 10% of vastus lateralis (VL) EMG max) during the knee extension and the ankle extension tasks respectively were significantly higher in the paretic leg of stroke participants than in healthy participants (26 ± 5% of Sol EMG max and 10 ± 3% of VL EMG max, respectively). Early heteronymous facilitation of Sol voluntary EMG in stroke participants (340 ± 62% of Sol unconditioned EMG) was significantly higher than in healthy participants (98 ± 34%). The later inhibition observed in all control participants was decreased in the paretic leg. Levels of coactivation of ankle extensors during the knee extension task were significantly correlated with both the increased facilitation (Pearson r = 0.59) and the reduced inhibition (r = 0.56) in the paretic leg. Measures of motor impairment were more consistently correlated with the levels of coactivation of biarticular muscles than those of monoarticular muscles.</p> <p>Conclusion</p> <p>These results suggest that the heteronymous pathways linking quadriceps to soleus may participate in the abnormal coactivation of knee and ankle extensors on the paretic side of stroke patients. The motor impairment of the paretic leg is strongly associated with the abnormal coactivation of biarticular muscles.</p

    Fischer-Tropsch diesel and biofuels exergy and energy analysis for low emissions vehicles

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    This research investigates the effects of a synthetic diesel-like fuel (Fischer-Tropsch diesel) and biofuels (ethanol and biodiesel) fuel blends on the energy-exergy efficiencies and gaseous exhaust emissions characteristics of a compression ignition engine. Two blends of alternative fuels denoted as E15B35FTD50 (15% ethanol, 35% biodiesel, and 50% Fischer-Tropsch diesel) and E15B35D50 (15% ethanol, 35% biodiesel, and 50% diesel) were experimentally studied on a single-cylinder diesel engine and compared to diesel fuel. The results show that the energetic and the exergetic efficiencies of the alternative fuels are comparable to those of the engine fueled with diesel fuel. The unburnt HC, NO, N2O, and NH3 emissions were reduced for the two alternative fuel blends compared to diesel, while CO emissions increased. The light HC species were found to slightly increase for the alternative fuel blends in comparison with diesel fuel. However, the total HC was considerably reduced by the combustion of E15B35FTD50 not only when compared to the diesel fuel combustion, but also when compared to E15B35D50. Overall, these results may contribute to identifying advantages and limitations in terms of energetic-exergetic analysis and emissions for the new generation of conventional diesel and hybrid electric vehicles that aim to achieve future emissions regulations.The Coordenação de Aperfeiçoamento de Pessoal de Nível Superior-Brasil (CAPES)-Finance Code 001 is also acknowledged for the scholarship (No. 88887.199341/2018-00) to pursue F.A.T. postgraduate studies under the International Cooperation Program with the University of Birmingham and CAPES (Ref. 40/2014)

    A comparative study of biofuels and Fischer–Tropsch diesel blends on the engine combustion Performance for reducing exhaust gaseous and particulate emissions

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    The worldwide consumption of fossil hydrocarbons in the road transport sector in 2020 corresponded to roughly half of the overall consumption. However, biofuels have been discreetly contributing to mitigate gaseous emissions and participating in sustainable development, and thus leading to the extending of the commercial utilization of internal combustion engines. In this scenario, the present work aims at exploring the effects of alternative fuels containing a blend of 15% ethanol and 35% biodiesel with a 50% fossil diesel (E15D50B35) or 50% Fischer–Tropsch (F-T) diesel (E15FTD50B35) on the engine combustion, exhaust emissions (CO, HC, and NOx), particulate emissions characteristics as well as the performance of an aftertreatment system of a common rail diesel engine. It was found that one of the blends (E15FTD50B35) showed more than 30% reduction in PM concentration number, more than 25% reduction in mean particle size, and more than 85% reduction in total PM mass with respect to conventional diesel fuel. Additionally, it was found that the E15FTD50B35 blend reduces gaseous emissions of total hydrocarbons (THC) by more than 25% and NO by 3.8%. The oxidation catalyst was effective in carbonaceous emissions reduction, despite the catalyst light-off being slightly delayed in comparison to diesel fuel blends.This research received no external fundin

    Mosaic in Vigna sinensis in the state of Pernambuco, Brazil. II. Symptons and host range of the Mosaic "II"

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    Foram descritos os sintomas do Mosaico "II" em Vigna sinensis (L.) Savi ex Hassk. e em uma coleção de plantas hospedeiras artificiais do vírus causador dessa doença. Essas hospedeiras estão distribuídas entre as famílias das Chenopodiaceae (quatro espécies), Compositae (uma espécie) e Leguminosae (16 espécies). Em 34 outras espécies pertencentes às famílias Apocinaceae, Caricaceae, Compositae, Commeliaceae, Cucurbitaceae, Gramineae, Iridaceae, Leguminosae, Malvaceae, Passifloraceae e Solanaceae, a inoculação do vírus não provocou sintomas externos nas plantas. O mesmo aconteceu com relação a cinco variedades de Vigna sinensis e 21 de Phaseolus vulgaris. Das 34 espécies acima referidas, foi possível recuperar o vírus das seguintes: Centrosema pubescens, Phaseolus angularis, Nicandra physaloides, Nicotiana tabacum e Physalis angulata.Symptoms and host range of Mosaic "II" isolated from Vigna sinensis (L.) Savi ex Hassk are presented. Native accessions and introduced cultivars of 55 species distributed among the following botanical families: Apocinaceae, Caricaceae, Chenopodiaceae, Compositae, Commelinaceae, Gramineae, Iridaceae, Leguminosae, Malvaceae, Passifloraceae and Solanaceae were included. Twenty one species tested exhibited symptoms of disease, 5 species were demonstrated to be symptomless carriers, and 29 species were not infected. Five cultivars of Vigna sinensis and 21 of Phaseolus vulgaris were resistant. All tests were conducted in the laboratory and greenhouse, and inoculations were by mechanical methods

    High performance silicon photonic devices based on practical metamaterials

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    Robert Halir, et al., "High performance silicon photonic devices based on practical metamaterials," OECC/PSC, 7-12 July 2019, Fukuoka (Japan)Subwavelength grating metamaterials are enabling a new generation of high-performance silicon photonic devices. Here we discuss the fundamental physics along with some of the latest advances in this rapidly expanding field.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech. Ministerio de Economía y Competitividad, Programa Estatal de Investigación Orientada a los Retos de la Sociedad (cofinanciado FEDER) – TEC2016-80718-R, TEC2015-71127-C2-1-R (FPI BES-2016-077798) and IJCI-2016-30484; Community of Madrid – S2018/NMT-4326, Marie Sklodowska-Curie –734331, Czech Science Foundation – 1900062

    Fungal and mycotoxins contamination in non-alcoholic beverages: the case of tea from Portuguese market and coffee beans from Brazil

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    This project was supported by FCT/MCTES UIDP/05608/2020, and UIDB/05608/2020. This work is also supported by national funds through FCT/MCTES/FSE/UE, 2023.01366.BD; UI/BD/153746/2022 and CE3C unit UIDB/00329/2020; UI/BD/151431/2021; and Instituto Politécnico de Lisboa, national support through IPL/2022/InChildhealth/BI/12M; IPL/IDI&CA2023/FoodAIIEU_ESTeSL; IPL/IDI&CA2023/ASPRisk_ESTeSL; IPL/IDI&CA2023/ARAFSawmills_ESTeSLAgriculture constitutes one of the most sensitive sectors that could be affected by climate change. Among the xenobiotics contaminating agricultural crops, fungi and mycotoxins are the most challenging since their presence represents an economic burden due to crop loss and serious health effects related to animals and humans with severe repercussions. This study intends to characterize the fungal and mycotoxin contamination in tea available in the Portuguese market and in coffee from two Brazilian industries.info:eu-repo/semantics/publishedVersio

    Identification of genes encoding antimicrobial proteins in Langerhans cells

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    Langerhans cells (LCs) reside in the epidermis where they are poised to mount an antimicrobial response against microbial pathogens invading from the outside environment. To elucidate potential pathways by which LCs contribute to host defense, we mined published LC transcriptomes deposited in GEO and the scientific literature for genes that participate in antimicrobial responses. Overall, we identified 31 genes in LCs that encode proteins that contribute to antimicrobial activity, ten of which were cross-validated in at least two separate experiments. Seven of these ten antimicrobial genes encode chemokines
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