429 research outputs found

    Avaliação de insumos agrícolas por meio de testes ecotoxicológicos: fase preliminar.

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    A PROPOSAL FOR A HYBRID POWER TRAIN FOR A TRUCK

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    Aiming at reducing the emission of pollutants from automotive vehicles, international commissions indicate, at each given period, a target of admissible values for these pollutants, to be implemented by the automakers. A case like the future implementation of EuroVII, from 2025, in European regions. In parallel to these conditions, there are many studies with the objective of seeking alternatives for the propulsion of these combustion vehicles, for example, the application of fully electric or hybrid vehicles. This article aims to develop and implement a mathematical model for a proposal for a hybrid engine, in a low-power truck, resulting in a small diesel engine, powering the vehicle's alternator and battery, generating the charging for use in a main electric motor, that is, to develop with a focus on energy conservation and the environment, with a reduction in the size of a combustion engine and its emissions

    Ultrasonography Reliability in the Detection of Inflammatory and Structural Abnormalities: An Exercise in Multiple Joints

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    Background Ultrasonography is an image technique that allows rheumatologists to visualize structural and inflammatory changes within a joint. The objective of this study was to assess the interobserver and intraobserver reliability of musculoskeletal ultrasound (US) in the detection of inflammatory and destructive joint changes in patients with polyarthritis. Methods A Delphi exercise was undertaken to standardize and adapt the EULAR-OMERACT elementary US definitions of inflammatory lesions (effusion, synovial hypertrophy, power Doppler, bone erosions, and synovitis) for each joint. Fifteen patients were analyzed, and video clips of 600 joints were collected. Each joint was scored for the presence of each elementary component, on 2 separate occasions, by 6 examiners. Interobserver and intraobserver agreement analysis was assessed through Fleiss κ coefficient (κ). Results Considering all patients and all joints, the interobserver values were highest for erosions and lowest for effusion (κ = 0.7314 and κ = 0.6044, respectively). When analyzing different regions, the highest interobserver agreement was for tibiotalar joint (κ = 0.8043) and the lowest for wrist (κ = 0.6767). Intraobserver reliability was excellent for each and all elementary components and anatomical region. Conclusions The present study showed either a good or excellent US interobserver and intraobserver reliability in elementary elements and anatomical region. This kind of US reliability exercises are important for standardization of exploration in everyday practice by reducing the variability associated with this imaging technique, and ensuring a greater degree of homogeneity and future comparability in the assessment of disease activity in polyarthritis patients.info:eu-repo/semantics/publishedVersio

    Sub-Bandgap Sensitization of Perovskite Semiconductors via Colloidal Quantum Dots Incorporation

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    ABSTRACT: By taking advantage of the outstanding intrinsic optoelectronic properties of perovskite-based photovoltaic materials, together with the strong near-infrared (NIR) absorption and electronic confinement in PbS quantum dots (QDs), sub-bandgap photocurrent generation is possible, opening the way for solar cell efficiencies surpassing the classical limits. The present study shows an effective methodology for the inclusion of high densities of colloidal PbS QDs in a MAPbI3 (methylammonium lead iodide) perovskite matrix as a means to enhance the spectral window of photon absorption of the perovskite host film and allow photocurrent production below its bandgap. The QDs were introduced in the perovskite matrix in different sizes and concentrations to study the formation of quantum-confined levels within the host bandgap and the potential formation of a delocalized intermediate mini-band (IB). Pronounced sub-bandgap (in NIR) absorption was optically confirmed with the introduction of QDs in the perovskite. The consequent photocurrent generation was demonstrated via photoconductivity measurements, which indicated IB establishment in the films. Despite verifying the reduced crystallinity of the MAPbI3 matrix with a higher concentration and size of the embedded QDs, the nanostructured films showed pronounced enhancement (above 10-fold) in NIR absorption and consequent photocurrent generation at photon energies below the perovskite bandgap.info:eu-repo/semantics/publishedVersio

    End-users’ perspectives of an eHealth platform to promote physical activity in COPD: a qualitative study

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    Introduction: eHealth platforms can be used as a tool to promote physical activity (PA) in patients with COPD. When developing such platforms, a bottom-up approach is needed to ensure that patients’ and healthcare professionals’ (HCP) needs and expectations are addressed. Aim: To assess patients’ and HCP’ perspectives on the ideal eHealth platform (web application - app - for HCP + mobile app for patients) for PA promotion in patients with COPD. Methods: One focus group with 5 patients (68±8 yrs, FEV1 44±21pp) and 6 individual interviews with HCP (physicians and physiotherapist, 39±10 yrs) were conducted using a semi-structured interview guide. Interviews were recorded and transcripts were analysed using the Grounded Theory approach. Results: Participants considered an eHealth platform to promote patients' PA valuable. Both groups suggested that PA should be individualised according to patients’ characteristics. The main features for a mobile app included: shared goal setting, PA progress graphs, motivational messages and goal badges, notifications, a bi-directional communication system to support patients and information on breathing exercises. Both groups highlighted the importance of measuring steps, PA duration, SpO2, and dyspnoea on exertion. For the web app, the HCP highlighted the importance of a notification system to signal PA changes or non-compliance (e.g., colour scheme), as well as tabs for PA goal setting and monitoring. HCP recommended this platform for patients with stable or mild disease and/or those attending pulmonary rehabilitation. Conclusion: Findings provide guidance to the design of future eHealth platforms for PA promotion in COPD.publishe

    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

    Intrahepatic cholestasis of pregnancy

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    Intrahepatic cholestasis of pregnancy (ICP) is a cholestatic disorder characterized by (i) pruritus with onset in the second or third trimester of pregnancy, (ii) elevated serum aminotransferases and bile acid levels, and (iii) spontaneous relief of signs and symptoms within two to three weeks after delivery. ICP is observed in 0.4–1% of pregnancies in most areas of Central and Western Europe and North America, while in Chile and Bolivia as well as Scandinavia and the Baltic states roughly 5–15% and 1–2%, respectively, of pregnancies are associated with ICP. Genetic and hormonal factors, but also environmental factors may contribute to the pathogenesis of ICP. Intrahepatic cholestasis of pregnancy increases the risk of preterm delivery (19–60%), meconium staining of amniotic fluid (27%), fetal bradycardia (14%), fetal distress (22–41%), and fetal loss (0.4–4.1%), particularly when associated with fasting serum bile acid levels > 40 μmol/L. The hydrophilic bile acid ursodeoxycholic acid (10–20 mg/kg/d) is today regarded as the first line treatment for intrahepatic cholestasis of pregnancy. Delivery has been recommended in the 38th week when lung maturity has been established

    What motivates patients with COPD to be physically active? A cross-sectional study

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    Motivation can be broadly defined as what moves people to act. Low motivation is a frequently reported factor for the reduced physical activity (PA) levels observed in patients with chronic obstructive pulmonary disease (COPD). This study assessed patients' motives to be physically active, according to three pulmonary rehabilitation (PR) participation groups (Never PR, Previous PR and Current PR) and explored whether these motives were related to the PA levels and clinical characteristics. The motives to be physically active were assessed with the Exercise Motivation Inventory-2 (EMI-2, 14 motivational factors, five dimensions) and PA with accelerometry (PA groups: 0.05) but having less symptoms and ≥two comorbidities were associated with higher scores in psychological/health and body-related motives, respectively (p < 0.05). The findings may encourage health professionals to actively explore with patients their motives to be physically active to individualise PA promotion.publishe
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