542 research outputs found

    Implementation and Performance Analysis of a Low Resolution OFDM System Prototype With Low Cost Hardware

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    The present work focus on the implementation and analyze of performance of a low-resolution OFDM system prototype with low-cost hardware. A software defined radio (SDR) system was chosen in this implementation due to its various advantages over a traditional radio system. Among the options of SDR devices available, the use of universal software radio peripherals (USRP) was avoided due to its high cost, despite its popularity in this field of research. Alternatively, a combination of two low-cost SDRs, "Hackrf One" and "RTL- SDR Blog V3" with the GNU Radio, a popular, free and open source radio software, were used. Thus, it was possible to emulate the behavior of a low resolution ADC in the receiver, characterize its performance and estimate its energy savings. This allowed us to determine the feasibility of building a component with the analog-to-digital conversion function with few bits of resolution. We conclude that the performance of an ADC with at least 5 bits of resolution is pretty reasonable and that this reduction in the number of bits, in comparison to 8-bit ADC, represents a fairly expressive energy saving

    Ketogenic Diet and Drug-Induced Hepatotoxicity During Tuberculosis Treatment

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    When therapy with hepatotoxic drugs is being considered, all other possible contributing agents of liver damage should be held to account. While not generally considered a risk factor, we present 2 cases in which ketogenic diet (KD) may have played a role in liver injury due to antituberculosis drugs. Ketogenic diet has been linked to liver injury, and while its pathophysiology remains obscure, carnitine depletion could play a role, as it is a mechanism of liver damage common to KD and antituberculosis drug regimens.info:eu-repo/semantics/publishedVersio

    Effect of flow perfusion conditions in the chondrogenic differentiation of bone marrow stromal cells cultured onto starch based biodegradable scaffolds

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    Cartilage tissue engineering (TE) typically involves the combination of a 3-D biodegradable polymeric support material, with primary chondrocytes or other cell types able to differentiate into chondrocytes. The culture environment in which cell–material constructs are created and stored is an important factor. Various bioreactors have been introduced in TE approaches to provide specific culturing environments that might promote and accelerate cells’ potential for chondrogenic differentiation and enhance the production of cartilage extracellular matrix. The aim of the present study was to investigate the chondrogenic differentiation of goat bone marrow cells (GBMCs) under flow perfusion culture conditions. For that purpose, GBMCs were seeded into starch–polycaprolactone fiber mesh scaffolds and cultured in a flow perfusion bioreactor for up to 28 days using culture medium supplemented with transforming growth factor-b1. The tissue-engineered constructs were characterized after several end points (7, 14, 21 and 28 days) by histological staining and immunocytochemistry analysis, as well as by glycosaminoglycan and alkaline phosphatase quantification assays. In addition, the expression of typical chondrogenic markers was assessed by real-time reverse-transcription polymerase chain reaction analysis. In general, the results obtained suggest that a flow perfusion microenvironment favors the chondrogenic potential of GBMCs.EXPERTISSUES NMP3-CT-2004-500283Fundação para a Ciência e a Tecnologia (FCT) - Vivo Tissue (PTDC/CVT/67677/2006

    Natural pigments of anthocyanin and betalain for coloring soy-based yogurt alternative

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    The aim of this work was to evaluate the color stability of betalain- and anthocyanin-rich extracts in yogurt-like fermented soy, in order to develop a preliminary understanding of how these pigments behave in this type of food system during storage for 21 days at 4 °C. Thus, the extracts of red beetroot, opuntia, hibiscus and red radish were integrated into the yogurt-like fermented soy in two different ways—directly after lyophilization, and encapsulated in nanosystems based in soybean lecithin—as this approach has never been used to further increase the value and potential of the dairy-free alternatives of yogurt-like fermented soy. The results showed that non-encapsulated betalain-rich extracts from red radish are the most promising for coloring yogurt-like fermented soy. However, encapsulated opuntia extracts can also be an alternative to supplement the soy fermented beverages with betalains, without changing significantly the color of the system but giving all its health benefits, due to the protection of the pigments by nanoencapsulation.This research was funded by COMPETE 2020 program, co-financed by the FEDER and the European Union, PTDC/ASP-AGR/30154/2017 (POCI-01-0145-FEDER-030154). Foundation for Science and Technology (FCT, Portugal), and FEDER-COMPETE-QREN-EU funded research centers CQ-UM (UID/QUI/00686/2019), CF-UM-UP (UID/FIS/04650/2019) and REQUIMTE (UIDB/50006/2020)

    Beetroot as a source of natural dyes for ham

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    Beetroot (Beta vulgaris L.) was subjected to extraction procedures in order to obtain the respective extracts containing the natural dyes and subjected to cytotoxicity assays in AGS cell line. Encapsulation of the extracts in nanosystems based on soybean lecithin and maltodextrin was performed. Lyophilized extracts before and after encapsulation in maltodextrin were applied in the formulation of leg ham and used in pilot scale of production. The colour of ham samples from the different assays was evaluated visually and by colorimetry.Dias, S.; Pereira, D.M.; Castanheira, E.M.S.; Fortes, A.G.; Pereira, R.; Gonçalves, a.M.S.T. Beetroot as a Source of Natural Dyes for Ham. Proceedings 2019, 41, 82. https://doi.org/10.3390/ecsoc-23-0662

    Effect of bacterial ice nuclei on the frequency and intensity of lightning activity inferred by the BRAMS model

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    Many studies from the last decades have shown that airborne microorganisms can be intrinsically linked to atmospheric processes. Certain bacteria may constitute the most active ice nuclei found in the atmosphere and might have some influence on the formation of ice crystals in clouds. This study deals with the ice nucleation activity of <i>Pseudomonas syringae</i> inside of thunderstorms through numerical simulations using BRAMS (<i>Brazilian Regional Atmospheric Model System</i>). The numerical simulations were developed in order to investigate the effect on the total amount of rainwater as a function of ice nuclei (IN) <i>P. syringae</i> concentrations with different scenarios (classified as S2 to S4 scenarios) corresponding to a maximum of 10<sup>2</sup> to 10<sup>4</sup> IN bacteria per liter of cloud water plus the BRAMS default (classified as S5 scenario). Additionally, two other scenarios were included without any IN (S1) and the sum of RAMS default and S4 scenario (classified as S6). The chosen radiosonde data is for 3 March 2003, typical summertime in São Paulo City which presents a strong convective cell. The objective of the simulations was to analyze the effect of the IN concentrations on the BRAMS modeled cloud properties and precipitation. The simulated electrification of the cloud permitted analysis of the total flashes estimated from precipitable and non-precipitable ice mass fluxes in two different lightning frequencies. Among all scenarios, only S4 and S6 presented a tendency to decrease the total cloud water, and all bacteria scenarios presented a tendency to decrease the total amount of rain (−8%), corroborating other reports in the literature. All bacteria scenarios also present higher precipitable ice concentrations compared to S5 scenario, the RAMS default. The main results present the total flash number per simulation as well. From the results, the total flash numbers, from both lightning frequencies, in S4 and S6 scenarios, are from 3.1 to 3.7 higher than the BRAMS default. Even the lower bacterial concentrations (scenarios S2 and S3) produced 3 time higher number of flashes, compared to S5 scenario. This result is a function of the hydrometeors in each simulation. In conclusion, IN bacteria could affect directly the thunderstorm structure and lightning formation with many other microphysical implications

    Regionalizing eco-toxicity characterization factors for copper soil emissions considering edaphic information for Northern Spain and Portuguese vineyards

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    The management of vineyards depends on the use of plant protection agents. Regardless of the numerous environmental impacts that these pesticides generate during their production, their dosage as pest control agents in vineyards causes an important toxic effect that must be monitored. Copper-based inorganic pesticides are the most widely used agents to control fungal diseases in humid wine-growing regions. It is, however, significant that the environmental analysis of their use through the Life Cycle Assessment (LCA) methodology does not provide detailed information on the potential toxicity of this type of pesticides. Hence, most studies report average values for copper characterization factors (CFs), excluding local soil characteristics. The objective of the study was the spatial characterization of the ecotoxicity factors of copper soil emissions as a function of the chemical characteristics of vineyard soils located in Portugal and Galicia (NW Spain). A multiple linear regression model was applied to calculate the comparative toxic potential. Subsequently, CFs for copper were calculated based on spatial differentiation considering the variable properties of the soil within each wine appellation. The CFs obtained for the area evaluated ranged from 141 to 5937 PAF·m3·day/kgCu emitted, for fibric histosols (HSf) and dystic cambisols (CMd), respectively. Moreover, the average values obtained for Galician and Portuguese soils were 1145 and 2274 PAF·m3·day/kgCu emitted, respectively. The results obtained illustrate the high variability of CF values as a function of the chemical characteristics of each type of soil. For example, Cu soil mobility was linked to organic carbon content and pH. Finally, to validate the representativeness of the calculated CFs, these were applied to the results of 12 literature life cycle inventories of grape production in the area evaluated, revealing that impact scores associated with Cu emissions can considerably vary when spatially-differentiated CFs are implemented.publishe

    Application of natural pigments in ordinary cooked ham

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    The possibility of obtaining a carmine or pink color on ordinary cooked ham by applying natural dyes from three plant species, namely red radish (Raphanus sativus L.), hibiscus (Roselle sabdariffa L.) and red beetroot (Beta vulgaris L.), was investigated. The extracts were evaluated for the stability at physical-chemical parameters and subjected to cytotoxicity assays in the gastric cell line AGS Encapsulation of the extracts in soybean lecithin liposomes and maltodextrin microcapsules was performed. Lyophilized extracts before and after encapsulation in maltodextrin were applied in the formulation of ordinary cooked ham and used in a pilot scale of production. The color of cooked ham samples from different assays was evaluated visually and by colorimetry. The results suggest that the coloration of ordinary cooked ham obtained with extracts of red beetroot is very promising for future applications in this type of meat product.This research was funded by COMPETE 2020 program, co-financed by the FEDER and the European Union, PTDC/ASP-AGR/30154/2017 (POCI-01-0145-FEDER-030154). Foundation for Science and Technology (FCT, Portugal), and FEDER-COMPETE-QREN-EU funded research centres CQ-UM (UID/QUI/00686/2019), CF-UM-UP (UID/FIS/04650/2019) and REQUIMTE (UIDB/50006/2020). The APC was also funded by FCT

    Spectrum and Frequency of GJB2 Mutations in a Cohort of 264 Portuguese Nonsyndromic Sensorineural Hearing Loss Patients

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    OBJECTIVE: To assess the spectrum and prevalence of mutations in the GJB2 gene in Portuguese nonsyndromic sensorineural hearing loss (NSSHL) patients. DESIGN: Sequencing of the coding region, basal promoter, exon 1, and donor splice site of the GJB2 gene; screening for the presence of the two common GJB6 deletions. STUDY SAMPLE: A cohort of 264 Portuguese NSSHL patients. RESULTS: At least one out of 21 different GJB2 variants was identified in 80 (30.2%) of the 264 patients analysed. Two mutant alleles were found in 53 (20%) of these probands, of which 83% (44/53) harboured at least one c.35delG allele. Twenty-seven (10.2%) of the probands harboured only one mutant allele. Subsequent analysis revealed that the GJB6 deletion del(GJB6-D13S1854) was present in at least 7.4% (2/27) of the patients carrying only one mutant GJB2 allele. Overall, one in five (55/264) of the patients were diagnosed as having DFNB1-related NSSHL, of which the vast majority (53/55) harboured only GJB2 mutations. CONCLUSIONS: This study provides clear demonstration that mutations in the GJB2 gene are an important cause of NSSHL in Portugal, thus representing a valuable indicator as regards therapeutical and rehabilitation options, as well as genetic counseling of these patients and their families
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