Análise da percepção ergonómica de postos de trabalho dotados de microscópio

A adequabilidade do dimensionamento dos postos e equipamentos de trabalho aos trabalhadores e às tarefas desenvolvidas é fundamental para a promoção de condições de conforto e prevenção do desenvolvimento de LMERT. A percepção dos trabalhadores é importante para a análise e intervenção ergonómica. Este estudo teve como objectivo analisar a percepção dos trabalhadores sobre a adequabilidade dos postos de trabalho que envolvam tarefas ao microscópio. Foi analisada a adequabilidade das dimensões dos elementos do mobiliário e do microscópio, e desenvolvido e aplicado o Questionário de Análise Ergonómica de Tarefas ao Microscópio (QAETM). O questionário contemplou questões associadas a características pessoais, actividades desenvolvidas, percepções de risco e sensações de dor e/ou desconforto. A análise das dimensões dos postos de trabalho mostrou que estas se apresentam em geral inadequadas às tarefas realizadas. Verificou-se ainda que alguns postos de trabalho tinham sofrido intervenções por parte dos profissionais. A maioria dos inquiridos considera as dimensões das cadeiras adequadas, contrariamente à das bancadas. No que respeita ao microscópio, foram sugeridas alterações ao nível dos parafusos de focagem, movimentação de platina e altura e inclinação das oculares. Este estudo permitiu verificar que alguns dos profissionais apresentam uma baixa percepção ergonómica, não sendo na sua maioria capazes de identificar a falta de adequabilidade das dimensões dos seus postos de trabalho. Apesar do referido, alguns revelaram preocupações ergonómicas, sugerindo e identificando, nomeadamente ao nível do microscópio, situações a alterar, tendo mesmo a iniciativa de intervir no seu posto de trabalho de modo a promover uma melhor postura.info:eu-repo/semantics/publishedVersio

Metal transfer to sediments, invertebrates and fish following waterborne exposure to silver nitrate or silver sulfide nanoparticles in an indoor stream mesocosm

Engineered nanomaterials; Silver uptake; TroutNanomaterials dissenyats; Captació de plata; TruitaNanomateriales de ingeniería; Absorción de plata; TruchaThe fate of engineered nanomaterials in ecosystems is unclear. An aquatic stream mesocosm explored the fate and bioaccumulation of silver sulfide nanoparticles (Ag2S NPs) compared to silver nitrate (AgNO3). The aims were to determine the total Ag in water, sediment and biota, and to evaluate the bioavailable fractions of silver in the sediment using a serial extraction method. The total Ag in the water column from a nominal daily dose of 10 μg L−1 of Ag for the AgNO3 or Ag2S NP treatments reached a plateau of around 13 and 12 μg L−1, respectively, by the end of the study. Similarly, the sediment of both Ag-treatments reached ~380 μg Ag kg−1, and with most of it being acid-extractable/labile. The biota accumulated 4–59 μg Ag g−1 dw, depending on the type of Ag-treatment and organism. The oligochaete worm, Lumbriculus variegatus, accumulated Ag from the Ag2S exposure over time, which was similar to the AgNO3 treatment by the end of the experiment. The planarian, Girardia tigrina, and the chironomid larva, Chironomus riparius, showed much higher Ag concentrations than the oligochaete worms; and with a clearer time-dependent statistically significant Ag accumulation relative to the untreated controls. For the pulmonate snail, Physa acuta, bioaccumulation of Ag from AgNO3 and Ag2S NP exposures was observed, but was lower from the nano treatment. The AgNO3 exposure caused appreciable Ag accumulation in the water flea, Daphnia magna, but accumulation was higher in the Ag2S NP treatment (reaching 59 μg g−1 dw). In the rainbow trout, Oncorhynchus mykiss, AgNO3, but not Ag2S NPs, caused total Ag concentrations to increase in the tissues. Overall, the study showed transfer of total Ag from the water column to the sediment, and Ag bioaccumulation in the biota, with Ag from Ag2S NP exposure generally being less bioavailable than that from AgNO3.This work was supported by the project NanoFASE (Nanomaterial Fate and Speciation in the Environment), financed by the European Union's Horizon 2020 research and innovation programme under grant agreement no 646002. RDH was partly supported by NanoHarmony under grant agreement 885931 in Horizon 2020 while redrafting the main text. PVS was awarded with a PhD grant (SFRH/BD/51571/2014) by FCT – Fundação para a Ciência e a Tecnologia. SL and PVS received additional financial support from FCT/MCTES, through national funds, to CESAM (UIDP/50017/2020+UIDB/50017/2020+ LA/P/0094/2020)

numerical modelling and validation

Publisher Copyright: © 2023 The Author(s)This study investigates the Non-Destructive Testing (NDT) inspection of 3D-printed fibre-reinforced polymers, comparing the conventional Active Transient Thermography (ATT) technique with a novel variant known as Double Active Transient Thermography (DATT). Finite element models for the simulation of both inspection techniques are validated by evaluating two statistical measures to correlate the numerical results with the experimental responses. The thermal contrast obtained with DATT was approximately twice the one obtained with ATT, for all tested samples. Numerical models allowed an insight evaluation of the heat dissipation along the thickness of the specimens, specifically around the fibres and the defects. These validated numerical models evidenced a relevant tool to predict the results of thermal contrast and to optimize the inspection parameters.publishersversionpublishe

Hypersomnia in Whipple disease: case report.

Arq Neuropsiquiatr. 2006 Sep;64(3B):865-8. Hypersomnia in Whipple disease: case report. Maia LF, Marta M, Lopes V, Rocha N, Lopes C, Martins-da-Silva A, Monteiro L. SourceDepartment of Neurological Disordes and Senses, Hospital Geral de Santo António, Largo Prof. Abel Salazar, 4099-001 Porto, Portugal. Abstract Whipple disease (WD) is a rare systemic infection caused by Tropheryma whippelii. Neurological involvement has been recognised in 40% of patients, either as initial manifestations or during the course of the disease. We report on a 45 years-old man with WD with initial, persistent and irresistible episodes of daytime somnolence. The patient was HLA-DQB1*0602 positive (genetic marker for narcolepsy). WD diagnosis was suspected on clinical and MRI basis and confirmed by histological and immunohistochemical study of duodenal biopsy. Forty months later all clinical features improved, narcoleptic-like episodes disappeared and cerebral MRI and CSF normalised. Longitudinal neurophysiological studies revealed persistent sleep pattern abnormalities with sleep fragmentation, paucity of slow wave and of REM sleep. The disruption of the hypocretin circuitry in the hypothalamic - diencephalic region triggered by the infection was the probable cause of the hypersomnia and narcopleptic symptoms. WD should be added to the list of causes of secondary hypersomnia

Fast decellularization process using supercritical carbon dioxide for trabecular bone

Decellularization is a process that consists on the removal of immunogenic cellular material from a tissue, so that it can be safely implanted as a functional and bioactive scaffold. Most decellularization protocols rely on the use of harsh chemicals and very long washing processes, leading to severe changes in the ultrastructure and loss of mechanical integrity. To tackle these challenges, supercritical carbon dioxide (scCO2) is herein proposed as an alternative methodology for assisting decellularization of porcine trabecular bone tissue and is combined, for the first time, with Tri(n-butyl) phosphate (TnBP). Histological and DNA analysis revealed that both TnBP and scCO2 were able to extract the DNA content from the scaffolds, being this effect more pronounced in treatments that used TnBP as a co-solvent. The combined protocol led to a decrease in DNA content by at least 90%, demon- strating the potential of this methodology and opening new possibilities for future optimizations.info:eu-repo/semantics/publishedVersio

Evaluation of extracellular matrix formation in polycaprolactone and starch-compounded polycaprolactone nanofiber meshes when seeded with bovine articular chondrocytes

Cartilage defects are a major health problem. Tissue engineering has developed different strategies and several biomaterial morphologies, including natural-based ones, for repairing these defects. We used electrospun polycaprolactone (PCL) and starch-compounded PCL (SPCL) nanofiber meshes to evaluate extracellular matrix (ECM) formation by bovine articular chondrocytes (BACs). The main aim of this work was to evaluate the suitability of PCL and SPCL nanofiber meshes in chondrocyte cultures, and their capability to produce ECM when seeded onto these nanostructured materials. The effect of culture conditions (static vs dynamic) on ECM formation was also assessed. BACs were seeded onto PCL and SPCL nanofiber meshes using a dynamic cellseeding procedure and cultured under static or dynamic conditions for 4 weeks. Constructs were characterized using scanning electron microscopy, histology, immunolocalization of collagen types I and II, and glycosaminoglycan (GAG) quantification. Results show an extensive cell colonization of the entire nanofiber mesh, for both materials, and that chondrocytes presented typical spherical morphology. Some degree of cell infiltration inside the nanofiber meshes was noticeable for both materials. ECM formation and GAG were detected throughout the materials, evidencing typical construct maturation. PCL and SPCL nanofiber meshes are suitable as supports for ECM formation and therefore are adequate for cartilage tissue-engineering approaches.M. Alves da Silva would like to acknowledge the Portuguese Foundation for Science and Technology (FCT) for her grant (SFRH/BD/28708/2006), Marie Curie Actions-ALEA JACTA EST (MEST-CT-2004-008104), European NoE EXPERTISSUES (NMP3-CT-2004-500283), IP GENOSTEM (LSHB-CT-2003-503161) and NATURALLY NANO (POCTI/EME/58982/2004)

Keep on running – a randomized controlled trial to test a digital evidence-based intervention for sustained adoption of recreational running: rationale, design and pilot feasibility study

Background: This paper describes the rationale, intervention development, study design and results from the pilot feasibility study of the Keep On Running (KOR) trial. KOR aims to test a web-based brief theory-based intervention, targeting maintenance of recreational running behavior over time (i.e. relapse preventing). Methods: Intervention development was based both on Self- Determination Theory and on Self-Regulation Theory. As part of it, a pilot study was implemented (n=18) to measure intervention adherence and participant satisfaction in order to establish the feasibility and acceptability of the intervention toolkit. Furthermore, this pilot study was also used to test the feasibility and acceptability of the questionnaires selected to be part of the later RCT. Results: Pilot intervention acceptability was good, but overall adherence was low. Features such as feedback and social sharing should be added to the toolkit. The main trial should lessen questionnaire length and include data from usual monitoring gadgets and apps (APIs). The protocol of the RCT was adjusted to test the efficacy of the refined final version of the intervention, and the RCT that will test it, contributing to the understanding of recreational running sustainability, allowing the optimization of future interventions aimed at physical activity promotion.Fundação para a Ciência e Tecnologia - FCTinfo:eu-repo/semantics/acceptedVersio

Prospects for electrical performance tuning in Ca3Co4O9 materials by metallic Fe and Ni particles additions

This work further explores the possibilities for designing the high-temperature electrical performance of the thermoelectric Ca3Co4O9 phase, by a composite approach involving separate metallic iron and nickel particles additions, and by employing two different sintering schemes, capable to promote the controlled interactions between the components, encouraged by our recent promising results obtained for similar cobalt additions. Iron and nickel were chosen because of their similarities with cobalt. The maximum power factor value of around 200 µWm−1K−2 at 925 K was achieved for the composite with the nominal nickel content of 3% vol., processed via the twostep sintering cycle, which provides the highest densification from this work. The effectiveness of the proposed approach was shown to be strongly dependent on the processing conditions and added amounts of metallic particles. Although the conventional one-step approach results in Feand Ni-containing composites with the major content of the thermoelectric Ca3Co4O9 phase, their electrical performance was found to be significantly lower than for the Co-containing analogue, due to the presence of less-conducting phases and excessive porosity. In contrast, the relatively high performance of the composite with a nominal nickel content of 3% vol. processed via a two-step approach is related to the specific microstructural features from this sample, including minimal porosity and the presence of the Ca2Co2O5 phase, which partially compensate the complete decomposition of the Ca3Co4O9 matrix. The obtained results demonstrate different pathways to tailor the phase composition of Ca3Co4O9 -based materials, with a corresponding impact on the thermoelectric performance, and highlight the necessity of more controllable approaches for the phase composition tuning, including lower amounts and different morphologies of the dispersed metallic phases.publishe

Dynamic piezoelectric stimulation enhances osteogenic differentiation of human adipose stem cells

This work reports on the influence of the substrate polarization of electroactive β-PVDF on human adipose stem cells (hASCs) differentiation under static and dynamic conditions. hASCs were cultured on different β-PVDF surfaces (non-poled and “poled -”) adsorbed with fibronectin and osteogenic differentiation was determined using a quantitative alkaline phosphatase assay. “Poled -” β-PVDF samples promote higher osteogenic differentiation, which is even higher under dynamic conditions. It is thus demonstrated that electroactive membranes can provide the necessary electromechanical stimuli for the differentiation of specific cells and therefore will support the design of suitable tissue engineering strategies, such as bone tissue engineering.This work is funded by FEDER funds through the "Programa Operacional Fatores de Competitividade – COMPETE" and by national funds arranged by FCT- Fundação para a Ciência e a Tecnologia, project references PTDC/CTM-NAN/112574/2009 and PEST-C/FIS/UI607/2014. The authors also thank funding from Matepro –Optimizing Materials and Processes”, ref. NORTE-07-0124-FEDER-000037”, co-funded by the “Programa Operacional Regional do Norte” (ON.2 – O Novo Norte), under the “Quadro de Referência Estratégico Nacional” (QREN), through the “Fundo Europeu de Desenvolvimento Regional” (FEDER). CR, VS and VC thank the FCT for the SFRH/BPD/90870/2012, SFRH/BPD/64958/2009 and SFRH/BPD/97739/2013 grants, respectively. Academy of Finland is acknowledged for research funding (projects 136288 (VH) and 256931 (JP))

Estolides Synthesis Catalyzed by Immobilized Lipases

Estolides are vegetable-oil-based lubricants obtained from oleic acid or any source of hydroxy fatty acids. In this work, the estolides synthesis from oleic acid and methyl ricinoleate (biodiesel from castor oil), using immobilized commercial lipases (Novozym 435, Lipozyme RM-IM, and Lipozyme TL-IM) in a solvent-free medium was investigated. Acid value was used to monitor the reaction progress by determining the consumption of acid present in the medium. Novozym 435 showed the best performance. Water removal improved the conversion. Novozym 435 was more active at atmospheric pressure. Novozym 435 was reused four times with conversion reaching 15% after the fourth reaction at 80°C. Estolides produced under the reaction conditions used in this work presented good properties, such as, low temperature properties as pour point (−24°C), viscosity (23.9 cSt at 40°C and 5.2 cSt at 100°C), and viscosity index (153)