2,523 research outputs found

    The Regulation of Axon Diameter: From Axonal Circumferential Contractility to Activity-Dependent Axon Swelling

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    In the adult nervous system axon caliber varies widely amongst different tracts. When considering a given axon, its diameter can further fluctuate in space and time, according to processes including the distribution of organelles and activity-dependent mechanisms. In addition, evidence is emerging supporting that in axons circumferential tension/contractility is present. Axonal diameter is generically regarded as being regulated by neurofilaments. When neurofilaments are absent or low, microtubule-dependent mechanisms can also contribute to the regulation of axon caliber. Despite this knowledge, the fine-tune mechanisms controlling diameter and circumferential tension throughout the lifetime of an axon, remain largely elusive. Recent data supports the role of the actin-spectrin-based membrane periodic skeleton and of non-muscle myosin II in the control of axon diameter. However, the cytoskeletal arrangement that underlies circumferential axonal contraction and expansion is still to be discovered. Here, we discuss in a critical viewpoint the existing knowledge on the regulation of axon diameter, with a specific focus on the possible role played by the axonal actin cytoskeleton.This work from the authors’ group was supported by Prémio Melo e Castro—Santa Casa da Misericórdia de Lisboa; by the Infrastructure for NMR, EM and X-rays for Translational Research (iNEXT); and by FEDER—Fundo Europeu de Desenvolvimento Regional funds through the Norte Portugal Regional Operational Programme (NORTE 2020), Portugal 2020, and by Portuguese funds through FCT—Fundação para a Ciência e a Tecnologia/Ministério da Ciência, Tecnologia e Ensino Superior in the framework of the project NORTE-01-0145-FEDER-028623. AC and RP-C are funded by Fundação para a Ciência e Tecnologia—FCT (fellowships SFRH/BPD/114912/2016 and SFRH/BD/112112/2015, respectively)

    Conception and justification of a new test setup for assessment of the fatigue strength of connections between precast railway bridge girders

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    Important investments have been made worldwide in the modernization and construction of railway lines. Plans for new constructions, have also been laid out. Recently, precast concrete has been widely employed in the construction of railway bridges and viaducts. Several precast solutions have been applied, namely: I-shaped or U-shaped precast girders and uni-cellular or bi-cellular precast box girders. Regarding the structural scheme in the longitudinal direction, either simple span or continuous decks have been used. In this context, this work aims to contribute to the knowledge about the real performance of these structures through the development of a laboratory tests setup, for the study of this type of structure, focusing on the connection between the precast beams. The setup will be implemented at the Laboratory of Earthquake and Structural Engineering (LESE), several experimental campaigns on the cyclic behaviour of reinforced concrete elements have been carried out.6612-034D-AE05 | PEDRO DA SILVA DELGADON/

    The reality of an Obesity Surgical Treatment Center in Portugal

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    Introduction: Obesity surgery is used as the most effective treatment for morbid obesity, with better cost-benefit, less morbidity and mortality. The present study aimed to analyze the results of a surgical center for obesity treatment and integrate them with the most recent scientific evidence. Methods: Retrospective cross-sectional observational study involving 270 patients aged 18 years or older, who underwent bariatric surgery between July 2008 and February 2020 in a private hospital in Portugal. Results: The sample presented an average age of 44 ± 12 years, being mostly female (83.7%). The average pre-surgery Body Mass Index was 41.1 ± 4.9 kg/m2 . The most performed surgery was Gastric Bypass (80.4%), followed by Gastric Banding (14.8%) and Gastric Sleeve (4.8%). One month after surgery, there was a percentage of excess weight lost (% EWL) of 25.2 ± 9.6%. After 6 months, there was an average % EWL of 67.2 ± 23.2%. One year after surgery, the average % EWL was 75.7 ± 25.7%, the average Body Mass Index was 29.3 ± 4.6 kg/m2 and the average weight loss percentage was 29.5 ± 9.4%. Conclusion: Gastric Bypass is the mostly performed surgery, because it is the Gold Standard method for surgical treatment of obesity in this center. On average, all surgeries performed have extremely positive results of excess weight lost. After 1 year, patients maintained an average weight loss percentage of 29.5 ± 9.4%, in line with data presented in a study that estimated an average recorded weight loss percentage of 28.9%. Data like those presented by the American Society for Nutrition (ASN), the Obesity Action Coalition (OAC), the International Federation for the Surgery of Obesity and Metabolic Disorders (IFSO), the International Society for the Perioperative Care of the Obese Patient (ISPCOP) and the American Society for Parenteral and Enteral Nutrition (ASPEN) (2019), indicate a target weight loss percentage between 20 and 45%.info:eu-repo/semantics/publishedVersio

    Hematoproteinuria in a Lupic Patient with Diabetes: Which One is the Winner?

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    We report the case of a 46-year-old woman referred to nephrology consult for non-nephrotic proteinuria and hematuria.info:eu-repo/semantics/publishedVersio

    Food Intake in Pregnant Women with Gestational Diabetes Mellitus

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    Rationale: The aim of the present study was to verify the fulfillment of the nutritional requirements of macronutrients of pregnant women diagnosed with Gestational Diabetes Mellitus (GDM) at Lusíadas Lisboa Hospital. Inadequate glycemic control in GDM increases the risk of maternal, fetal and neonatal consequences, in this sense, nutritional therapy is essential during the follow-up of these pregnant women. Methods: Cross-sectional observational study. The study sample included 20 pregnant women diagnosed with GDM. Participants were asked to answer a questionnaire that included relevant data and to complete a three-day food record, for which they gave consent. A statistical analysis was performed with IBM® SPSS® 25. Results: The mean age measured was 35±4 years and 75% of the sample were in the 3º trimester. In the pre-gestational period, the sample had a Body Mass Index (BMI) of 26,2±5,3kg/m2 . The mean fasting capillary blood glucose was 89±9mg/dL and the postprandial was 119±19mg/dL. 75% reached the fasting glycemic objective and 95% the postprandial. It was also found that pregnant women who didn´t meet the goal set for fasting blood glucose, had higher pre-gestational BMI. In terms of macronutrients, it was found that 75% of the sample didn´t reach Total Energy Requirements (TER), 50% didn´t reach protein (1,1g/kg of current weight/day and 15-20% TER), 10% lipid (30% TER) and all carbohydrates (50-55% TER), with only 35% reaching the daily minimum of carbohydrates (175g). It was also found that sample didn´t reach 28g/day of fiber. Conclusions: The present study demonstrated the importance of an individualized nutritional intervention by a nutritionist with pregnant women diagnosed with GDM. The importance of this intervention is based on adherence to an adequate dietary pattern that prevents nutritional deficits, enhances clinical outcomes and contributes to the prevention of the incidence of GDM.info:eu-repo/semantics/publishedVersio

    Adaptability and Procedural Content Generation for Educational Escape Rooms

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    We present a literature review that aims to understand the role of the Educational Escape Room (EER) in improving the teaching, learning, and assessment processes through an EER design framework. The main subject is to identify the recent interventions in this field in the last five years. Our study focuses on understanding how it is possible to create an EER available to all students, namely visually challenged users. As a result of the implementation of new learning strategies that promote autonomous learning, a concern arose in adapting educational activities to each student's individual needs. To study the adaptability of each EER, we found the EER design framework essential to increase the student experience by promoting the consolidation of knowledge through narrative and level design. The results of our study show evidence of progress in students' performance while playing an EER, revealing that students' learning can be effective. Research on Procedural Content Generation (PCG) highlighted how important it is to implement adaptability in future studies of EERs. However, we found some limitations regarding the process of evaluating learning through the EERs, showing how important it is to study and implement learning analytics in future studies in this field

    Antifouling Marine Coatings with a Potentially Safer and Sustainable Synthetic Polyphenolic Derivative

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    The development of harmless substances to replace biocide-based coatings used to prevent or manage marine biofouling and its unwanted consequences is urgent. The formation of biofilms on submerged marine surfaces is one of the first steps in the marine biofouling process, which facilitates the further settlement of macrofoulers. Anti-biofilm properties of a synthetic polyphenolic compound, with previously described anti-settlement activity against macrofoulers, were explored in this work. In solution this new compound was able to prevent biofilm formation and reduce a pre-formed biofilm produced by the marine bacterium, Pseudoalteromonas tunicata. Then, this compound was applied to a marine coating and the formation of P. tunicata biofilms was assessed under hydrodynamic conditions to mimic the marine environment. For this purpose, polyurethane (PU)-based coating formulations containing 1 and 2 wt.% of the compound were prepared based on a prior developed methodology. The most effective formulation in reducing the biofilm cell number, biovolume, and thickness was the PU-based coating containing an aziridine-based crosslinker and 2 wt.% of the compound. To assess the marine ecotoxicity impact of this compound, its potential to disrupt endocrine processes was evaluated through the modulation of two nuclear receptors (NRs), peroxisome proliferator-activated receptor gamma (PPAR gamma), and pregnane X receptor (PXR). Transcriptional activation of the selected NRs upon exposure to the polyphenolic compound (10 mu M) was not observed, thus highlighting the eco-friendliness towards the addressed NRs of this new dual-acting anti-macro- and anti-microfouling agent towards the addressed NRs
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