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- 3D printed bioactive interference screw and PCL bio-filler for ligament fixationPublication . Rodrigues, Mafalda; Moreira, Rui; Silva, Inês V.; Duarte, Marta M.; Ribeiro, Viviana P.; Oliveira, Ana L.; Costa, João B.Musculoskeletal injuries, widespread across all ages, genders and sociodemographic groups, are prevalent in the knee joint and require a range of treatments - from conservative methods to surgical interventions, such as meniscal resection, repair, reconstruction or tissue engineering (TE) approaches. To address one of the most significant challenges in orthopedic procedures – long-term implant fixation – an innovative solution is being developed for knee ligaments and meniscus fixation. PLA screws are being developed through the combination of 3D printing, supercritical CO2 (scCO2) foaming and impregnation technologies, aiming to achieve a biodegradable and bioactive screw with improve bone integration ability. Additionally, to improve the anchor and fixation of the ligament treatments, PCL Bio-Fillers are being developed through the use of 3D printing, electrospinning and dipping methods with the final goal to induce the bone cells to reproduce itself (osteogenesis) and create a better grip between the ligaments and the bone. PLA screws were manufactured by 3D printing and further process to induce porosity by scCO2 foaming, followed by EPS impregnation through scCO2. Scanning electron microscopy (SEM) was used to evaluate microporosity and the EPS impregnation. The CO2 concentration, density and expansion ratio of the PLA screws were evaluated. FTIR (Fourier-transform infrared spectroscopy) was performed to evaluate chemical composition changes of the samples. DSC (Differential scanning calorimetry) was applied to analyze thermal stability both before and after treatment. PCL Bio-Fillers were produced by 3D printing, coated with PCL using electrospinning and dipped with bruxite. Then, to study the PCL fibers and bruxite dispersion, we have used the scanning electron microscopy (SEM) method. Results: Several conditions of foaming were tested (pressure, time, temperature and controlled expansion measures) and then, analyzed through SEM imaging. Samples with greater porosity were selected for further testing and analysis. The CO2 concentration results revealed that the saturation increase is proportional to the increase in pressure and inversely proportional to the increase in infill density. The expansion ratio results demonstrated that it typically decreases with increasing infill density and batch pressure. To optimize the 3D printed Bio-Fillers coated with PCL several parameters were adjusted (PCL concentration, flow rate, distance, potential difference, and nozzle size). Firstly, samples with apparent macroscopy uneven coating were remove with further analysis being performed via SEM analysis. The SEM analysis showed that increasing the potential difference and decreasing the flow rate produced more dispersed and thinner fibers. It also revealed that increase PCL concentration led to higher fiber density and size. In the end, the parameters that resulted in the better PCL fibers dispersion were with a concentration of 7,5% w/v of PCL, 20 μL/min flow rate, 10 cm of distance between the nozzle and the Bio-Filler, 23 kV of potential difference and 20 G of nozzle size. Further work is being performed to optimize the dipping process with bruxite and achieve an even coating. Conclusion: The sCO2 methodologies implemented were efficient in terms of generating porosity and EPS impregnation. EPS-induced bioactivity will be studied in the future.
- Alzheimer’s detection through structural MRI texture analysisPublication . Oliveira, M. J.; Ribeiro, P.; Rodrigues, P. M.Introduction: Alzheimer’s Disease (AD) is the most common cause of dementia. It affects mostly the elderly and is directly impacted by the observed growth of life expectancy. AD manifests as a chronic and progressive neurodegenerative disease, gradually deteriorating memory and cognitive abilities, and diminishing day-to-day quality of life. As the global population ages, understanding and addressing the challenges of AD becomes increasingly important for public health. Early detection enables treatment planning and symptom management, becoming an important study subject. In that sense, the present study aims to develop an automatic Structural MRI-based tool for the detection of AD and early stages of the disease (Mild Cognitive Impairment—MCI). Methods: 504 pre-processed sMRI images were decomposed into slices comprising the three anatomical planes (axial, coronal and sagittal) from where a set of 22 GLCM features were computed to feed 18 machine learning models, employing a hold-out method (80-20 train--test split). The analysis involved comparing three classes, HC (Healthy Controls), MCI and moderate AD in an All vs. All classification approach. Results and Discussion: A wide set of metrics was used to evaluate the model's performance. Combining the three anatomical planes, the All vs. All classification with a Linear Support Vector Machine yielded the following results: 82.2% for Accuracy, 82.2% for Recall, 83.0% for Precision, 89.9% Specificity, 81.9% for F1-Score and 89.8% for AUC. Conclusions: The results indicate that the proposed model distinguishes between AD, CN and MCI well. The methodology used provided a balanced performance across the seven metrics, highlighting the model's robustness and reliability in classifying the different groups. This approach shows significant potential for aiding in AD early detection and diagnosis and related cognitive impairments with an unusual approach.
- Anuário do sector de produção audiovisual em Portugal 2021Publication . Burnay, Catarina Duff; Ribeiro, Nelson
- Anuário do setor de produção audiovisual em Portugal 2020Publication . Burnay, Catarina Duff; Ribeiro, Nelson
- APIT | Associação de Produtores Independentes de Televisão | Barómetro 2020Publication . Burnay, Catarina Duff; Ribeiro, Nelson
- O Arco Maior, quando são os jovens a falarPublication . Azevedo, Joaquim
- Assessing the antimicrobial activity of essential oils against skin microorganisms using flow cytometryPublication . Lopes, Ana I.; Oliveira, Cláudia S.; Pintado, Manuela E.; Tavaria, Freni K.Introduction: The skin microbiome is a dynamic ecosystem vital for skin health, comprising bacteria like Staphylococcus spp. And Cutibacterium acnes, and fungi such as Candida and Malassezia spp. Dysbiosis, or microbial imbalance, can lead to conditions like acne and dermatitis. Current treatments, including anti-inflammatory drugs and antimicrobials, help manage dysbiosis but have limitations, such as microbiome disruption and antimicrobial resistance. Consequently, interest in natural alternatives,particularly essential oils (EOs), is increasing. Rich in bioactive terpenes and terpenoids, EOs target multiple cellular structures, reducing microbial adaptation and resistance. Flow cytometry, a powerful analytical tool, enables precise assessment of antimicrobial activity by distinguishing live and dead microorganisms using fluorescent staining. This study evaluates the antimicrobial effects of eucalyptus, lavender, and thyme EOs, offering insights into their potential as microbiome-friendly therapeutic agents. Methods: flow cytometry assay was used to assess the antimicrobial activity of eucalyptus, lavender, and thyme EOs against seven skinassociated microorganisms: methicillin-susceptible Staphylococcus aureus (MSSA), methicillin-resistant S. aureus (MRSA), Staphylococcus epidermidis (S. epidermidis), Cutibacterium acnes (C. acnes), Candida albicans (C. albicans), Candida tropicalis (C. tropicalis), and Malassezia furfur (M. furfur). Firstly, minimum inhibitory (MIC) and bactericidal (MBC) concentrations were determined. Then, to further explore EOs antimicrobial effects, microbial cells were exposed to MIC, ½MIC, and ¼MIC of each oil, followed by staining with propidium iodide (PI) and thiazole orange (TO). Flow cytometry was then used to assess viability, membrane integrity, and cell death. Additionally, fluorescence microscopy was performed on yeasts exposed to eucalyptus oil at ¼MIC, providing complementary validation of the flow cytometry findings. Results: The MIC and MBC values of the tested EOs ranged from 0.06% to 2.5% (v/v), with thyme EO showing the lowest values for all microorganisms, indicating its strongest antimicrobial activity. Among bacteria, S. epidermidis had the highest MIC/MBC values, suggesting greater resistance, while C. acnes had the lowest, indicating higher susceptibility. Among yeasts, C. albicans exhibited the highest values, whereas C. tropicalis and M. furfur were more susceptible. Flow cytometry confirmed these findings, validating thyme EO as the most effective, with the highest percentages of dead and injured cells. It also demonstrated that EOs antimicrobial activity is concentration-dependent. S. epidermidis had the highest percentage of live cells, reinforcing its resistance, while C. acnes had the lowest, confirming its susceptibility. C. albicans was more resistant than C. tropicalis. For M. furfur, fluorescence microscopy clarified an apparent lack of TO staining in flow cytometry, confirming viable but unstained cells. Conclusion: The selected EOs exhibited antimicrobial activity against all tested microorganisms. Thyme EO showed the strongest effect. Flow cytometry confirmed the MIC/MBC results, revealing that thyme EO induced the highest percentages of dead and injured cells at all tested concentrations. Among bacteria, S. epidermidis was the most resistant, while C. albicans was the most resistant yeast. For M. furfur, flow cytometry suggested an absence of live cells due to the lack of TO staining, even in untreated samples. However, fluorescence microscopy confirmed that M. furfur cells remained viable but did not stain green like Candida spp. This discrepancy likely results from the yeast’s lipid-rich membrane interfering with TO uptake, highlighting potential staining limitations. This work reinforces flow cytometry as a powerful tool to validate EO’s antimicrobial effects and support the potential of thyme, eucalyptus, and lavender EO’s as natural alternatives for managing skin dysbiosis while preserving microbiome balance.
- Assessment of the post-acute covid-19 syndrome cardiovascular effect through ECG analysisPublication . Ribeiro, P.; Souza, C. C. C. D.; Camerino, C. M. C.; Pordeus, D.; Leite, C. F.; Marques, J. A. L.; Madeiro, J. P.; Rodrigues, P. M.Introduction: SARS-CoV-2, a virus responsible for the emergence of the life-threatening disease known as COVID-19, exhibits a diverse range of clinical manifestations. The spectrum of symptoms varies widely, encompassing mild to severe presentations, while a considerable portion of the population remains asymptomatic. COVID-19, primarily a respiratory virus, has been linked to cardiovascular complications in some patients. Notably, cardiac issues can also arise after recovery, contributing to post-acute COVID-19 syndrome, a significant concern for patient health. The present study intends to evaluate the post-acute COVID-19 syndrome cardiovascular effect through ECG by comparing patients affected with cardiac diseases without COVID-19 diagnosis report (class 1) and patients with cardiac pathologies who present post-acute COVID-19 syndrome (class 2). Methods: From 2 body positions, a total of 10 non-linear features, extracted every 1 second under a multi-band analysis performed by Discrete Wavelet Transform (DWT), have been compressed by 6 statistical metrics to serve as inputs for an individual feature analysis by the means of Mann-Whitney U-test and XROC classification. Results and Discussion: 480 Mann-Whitney U-test statistical analyses and XROC discrimination approaches have been done. The percentage of statistical analysis with significant differences (p<0.05) was 30.42% (146 out of 480). The best overall results were obtained by approximating the feature Energy, with the data compressor Kurtosis in the body position Down. Those results were 83.33% of Accuracy, 83.33% of Sensitivity, 83.33% of Specificity and 87.50% of AUC. Conclusions: The results show that the applied methodology can be a way to show changes in cardiac behaviour provoked by post-acute COVID-19 syndrome.
- Os auxílios de estado e as medidas de política económica geralPublication . Borges, Carla Sofia RicardoControlo comunitário dos Auxílios de Estado e Política de Concorrência. O problema em sede de Mercado Único e alterações decorrentes do Tratado de Maastricht. A política comunitária em matéria de Auxílios de Estado - princípios gerais, orientações e critérios. Regime jurídico-comunitário dos Auxílios de Estado. Constituição económica, controlo democrático e papel dos Tribunais Nacionais. As Medidas de Política Económica Geral e a fundamental distinção entre as mesmas e os Auxílios de Estado. Critérios de detecção de “elementos de Auxílio”. Análise do art.º 92.º do TUE. O princípio geral de incompatibilidade e as derrogações. As dificuldades da distinção entre Medidas de Política Económica Geral e Auxílios de Estado em especial em matéria Tributária. Exemplos, Jurisprudência do TJUE e prática da CE. Conclui-se pela importância fundamental do controle comunitário do Auxílios de Estado para o normal funcionamento do Mercado Único e salvaguarda da competitividade das empresas. E, bem assim, pela delicadeza da distinção entre as Medidas de Política Económica Geral e os Auxílios de Estado e seu particular potencial de dificuldade na área tributária.
- Os benefícios fiscais em Portugal: conceitos, metodologia e práticaPublication . Oliveira, Francisca Guedes de; Leitão, Alexandra Pinto; Gonçalves, Ana; Portugal, António Moura; Reis, Bernardo Sousa; Pinto, Daniel Marques; Nascimento, Rui Dinis