105 results on '"Santos, João Miguel"'
Search Results
2. Smart Lysimeter with Crop and Environment Monitoring : Enhanced with Pest and Crop Control
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Almeida, Carlos, Martins, João C., Santos, João Miguel, Jasnau Caeiro, José, Rannenberg, Kai, Editor-in-Chief, Soares Barbosa, Luís, Editorial Board Member, Goedicke, Michael, Editorial Board Member, Tatnall, Arthur, Editorial Board Member, Neuhold, Erich J., Editorial Board Member, Stiller, Burkhard, Editorial Board Member, Tröltzsch, Fredi, Editorial Board Member, Pries-Heje, Jan, Editorial Board Member, Kreps, David, Editorial Board Member, Reis, Ricardo, Editorial Board Member, Furnell, Steven, Editorial Board Member, Mercier-Laurent, Eunika, Editorial Board Member, Winckler, Marco, Editorial Board Member, Malaka, Rainer, Editorial Board Member, Camarinha-Matos, Luis M., editor, Heijenk, Geert, editor, Katkoori, Srinivas, editor, and Strous, Leon, editor
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- 2022
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3. Selective root canal retreatment of a maxillary first molar: a case report with a 9-year follow up.
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Viegas, Olavo Guerreiro and Marques Santos, João Miguel
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- 2024
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4. Influence of Preoperative Pulp Inflammation in the Outcome of Full Pulpotomy Using a Dog Model
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Santos, João Miguel, Marques, Joana A., Diogo, Patrícia, Messias, Ana, Sousa, Vitor, Sequeira, Diana, and Palma, Paulo J.
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- 2021
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5. Regeneration of pulp-dentin complex using human stem cells of the apical papilla: in vivo interaction with two bioactive materials
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Sequeira, Diana B., Oliveira, Ana Rafaela, Seabra, Catarina M., Palma, Paulo J., Ramos, Carlos, Figueiredo, Maria H., Santos, Ana C., Cardoso, Ana L., Peça, João, and Santos, João Miguel
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- 2021
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6. Hybrid GaN-based optoelectronics for visible light communications
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Melo Santos, João Miguel
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621.3815 - Abstract
Development of light-emitting diode technology is driven mainly by the need for efficient solid-state lighting, but it is also creating opportunities for new applications such as visible light communications (VLC). Here, the solid-state visible light sources are used to transmit data with the added requirement of a short excited-state lifetime so that sources can be modulated at high speed. This research focuses on hybrid optical sources for visible light communications with an emphasis on novel formats of colour-converters for multi-wavelength photoluminescence as well as white-light generation. Such converters include red and green colloidal quantum dots, the organic semiconductor BBEHPV andII-VI / III-V epitaxial structures. Solution-processable and environmentally stable polymeric films based on red and green colloidal quantum dots are demonstrated. Modulation bandwidth up to 24 MHz, photoluminescence quantum yields up to 61% and peak emission tunability across the visible spectrum makes these materials interesting as colour-converters for VLC. Free-space data transmission was demonstrated in this case with data rates up to 400 Mbit/s and 500 Mbit/s using 2-PAM modulation scheme for green and red quantum dots, respectively. Hybrid sources consisting of 450nm InGaN LEDs with capillary-bonded micron-thick ZnCdSe/ZnCdMgSe multi-quantum-well colour-converting membranes with peak emission at 540 nm are reported. After processing, the membrane was capillary bonded onto the sapphire side of the μLED resulting in a maximum converted average power of 37 μW. The -3dB optical modulation bandwidth of the bare LED, hybrid device and II-VI were 79 MHz, 51 MHz and 145 MHz, respectively. Visible light communication using both InGaN LEDs and a InGaN laser diode, down-converted by a red-emitting AlInGaP multi-quantum-well nanomembrane are also reported. Similarly to the previous devices, the AlInGaP nanomembrane was bonded onto the μLED array. For the down-converted laser diode approach, the nanomembrane can be sandwiched between a sapphire lens and optionally onto a distributed feedback reflector. The down-converter structure is remotely excited by the laser diode. Data transmission up to 870 Mb/s using M-PAM andOFDM modulation schemes is demonstrated for the μLED integrated nanomembrane. ODFM transmission at 1.2Gb/s is achieved for the laser diode pumped sample.
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- 2017
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7. Effect of restorative timing on shear bond strength of composite resin/calcium silicate–based cements adhesive interfaces
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Palma, Paulo J., Marques, Joana A., Antunes, Márcia, Falacho, Rui I., Sequeira, Diana, Roseiro, Luís, Santos, João Miguel, and Ramos, João C.
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- 2021
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8. BIM-based environmental impact assessment for infrastructure design projects
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van Eldik, Maarten Albert, Vahdatikhaki, Faridaddin, dos Santos, João Miguel Oliveira, Visser, Maarten, and Doree, Andre
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- 2020
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9. Histological Bone-Healing Evaluation of Critical-Size Defects Filled with β-Tricalcium Phosphate in Rat Tibiae.
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Vasques, Ana Maria Veiga, Bueno, Carlos Roberto Emerenciano, Guimarães, Maria Rosa Felix de Souza Gomide, Valentim, Diego, da Silva, Ana Cláudia Rodrigues, Benetti, Francine, Santos, João Miguel Marques, Cintra, Luciano Tavares Angelo, and Dezan Junior, Eloi
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RATS ,TIBIA ,COMPACT bone ,LABORATORY rats ,BONE growth ,PHOSPHATES - Abstract
Bone defects may be a result of different pathologies and represent a challenge in different fields of dentistry. Techniques for the correction of bone defects involving the use of several types of grafts have been proposed. This study evaluated bone repair in rat tibiae after surgically created critical-size defects were filled with β-tricalcium phosphate (RTR
® , Septodont, FR). Critical-size bone defects were created in the tibiae of 32 male Wistar rats, which were divided into four groups (n = 8): Control 30 days, Control 90 days, RTR® 30 days, and RTR® 90 days. After the experimental period, the animals were euthanized and specimens were collected, embedded in paraffin, serially cut, and stained with hematoxylin and eosin to evaluate the inflammatory and repair response. Two parameters were analyzed: neoformed bone tissue areas (NBA) and neoformed cortical areas (NCA). Statistical analysis was performed by ANOVA and Tukey's test (p < 0.05). The RTR® group demonstrated superior bone healing compared with the control group in both analyzed parameters (NBA and NCA), with repair of the cortical bone and bone-tissue formation in the central region of the defect, which showed partial repair in the defect area (p < 0.05). RTR® enhanced bone neoformation in the adopted experimental model and may be a useful biomaterial to boost healing in cases of critical-size bone defects. [ABSTRACT FROM AUTHOR]- Published
- 2024
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10. Effects of endodontic irrigation solutions on structural, chemical, and mechanical properties of coronal dentin: A scoping review.
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Marques, Joana A., Falacho, Rui I., Santos, João Miguel, Ramos, João Carlos, and Palma, Paulo J.
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DENTIN anatomy ,MATERIALS testing ,ENDODONTICS ,MEDICAL information storage & retrieval systems ,DENTAL materials ,ETHYLENEDIAMINETETRAACETIC acid ,CHELATING agents ,SODIUM hypochlorite ,BIOMEDICAL materials ,SYSTEMATIC reviews ,MEDLINE ,LITERATURE reviews ,MEDICAL databases ,ROOT canal treatment ,IRRIGATION (Medicine) ,ONLINE information services - Abstract
Objective: This review aims to assess structural, chemical, and mechanical properties of coronal dentin after endodontic irrigation. Materials and Methods: Reporting followed the PRISMA extension for scoping reviews. An electronic search was carried out in PubMed, Embase, and Cochrane Library. Records filtered by language and published up to November 4, 2022 were independently screened by two researchers. Studies evaluating structural, chemical, or mechanical properties of human permanent coronal dentin after irrigation within the scope of nonsurgical root canal treatment were included. Data were extracted regarding study type, sample description and size, experimental groups, outcome, evaluation method, and main findings. Results: From the initial 1916 studies, and by adding 2 cross‐references, 11 in vitro studies were included. Seven studies provide ultrastructural and/or chemical characterization, and six assessed microhardness and/or flexural strength. One percent to 8% sodium hypochlorite (NaOCl) and 1%–17% ethylenediaminetetraacetic acid (EDTA) were the most commonly tested solutions, with contact times of 2–240 min (NaOCl) and 1–1440 min (EDTA) being evaluated. Conclusions: Overall, the literature is consensual regarding the inevitable impact of NaOCl and chelating agents on coronal dentin, with both deproteinizing and decalcifying effects being concentration‐ and time‐dependent. The alteration of mechanical parameters further confirmed the surface and subsurface ultrastructural and chemical changes. Clinical Significance: Endodontic treatment success highly depends on restorative sealing. Understanding the result of exposing coronal dentin, the main substrate for bonding, to irrigants' action is crucial. The deproteinizing and decalcifying effects of NaOCl and chelating agents are both concentration‐ and time‐dependent, causing surface and subsurface ultrastructural, chemical, and mechanical alterations. [ABSTRACT FROM AUTHOR]
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- 2024
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11. Diagnostic Accuracy of Cone Beam Computed Tomography and Periapical Radiography for Detecting Apical Root Resorption in Retention Phase of Orthodontic Patients: A Cross-Sectional Study.
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Pereira, Sónia A., Corte-Real, Ana, Melo, Ana, Magalhães, Linda, Lavado, Nuno, and Santos, João Miguel
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CONE beam computed tomography ,ROOT resorption (Teeth) ,RADIOGRAPHY ,CROSS-sectional method - Abstract
Objectives: This clinical study aimed to evaluate and compare the diagnostic accuracy of intraoral periapical radiography (PR) and cone beam computed tomography (CBCT) in detecting external apical root resorption (EARR) in orthodontic patients during the retention phase. Methods: The research involved 41 Caucasian patients who had undergone comprehensive orthodontic treatment, with a total of 328 teeth analyzed. The Kappa values for inter- and intra-examiner agreement were high for both PR and CBCT, indicating a robust level of agreement among examiners. The study used a four-point scale for classifying EARR. Results: This study showed comparable accuracy, sensitivity, and specificity between PR and CBCT when using the most stringent criterion of "Definitely present". The data suggested that CBCT outperformed PR when using a less stringent criterion ("Definitely present" or "Probably present"), particularly for maxillary incisors. However, overall diagnostic performance, as measured by the area under the ROC curve, showed only a slight advantage for CBCT over PR. Areas under the ROC curve range between 0.85 and 0.90 for PR and between 0.89 and 0.92 for CBCT. According to DeLong's test, there is no evidence to conclude that the area under the ROC curve is different for PR and CBCT. Conclusions: Both PR and CBCT are accurate diagnostic tools for identifying EARR, with PR being deemed more suitable for routine clinical use due to its cost-effectiveness and lower radiation exposure. The findings emphasize the importance of considering the risk-benefit ratio when deciding on imaging modalities for monitoring EARR in orthodontic patients. [ABSTRACT FROM AUTHOR]
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- 2024
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12. Scaffolds for Dentin–Pulp Complex Regeneration.
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Sequeira, Diana B., Diogo, Patrícia, Gomes, Brenda P. F. A., Peça, João, and Santos, João Miguel Marques
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REGENERATION (Biology) ,DENTAL pulp ,TISSUE engineering ,GROWTH factors ,RESEARCH questions - Abstract
Background and Objectives: Regenerative dentistry aims to regenerate the pulp–dentin complex and restore those of its functions that have become compromised by pulp injury and/or inflammation. Scaffold-based techniques are a regeneration strategy that replicate a biological environment by utilizing a suitable scaffold, which is considered crucial for the successful regeneration of dental pulp. The aim of the present review is to address the main characteristics of the different scaffolds, as well as their application in dentin–pulp complex regeneration. Materials and Methods: A narrative review was conducted by two independent reviewers to answer the research question: What type of scaffolds can be used in dentin–pulp complex regeneration? An electronic search of PubMed, EMBASE and Cochrane library databases was undertaken. Keywords including "pulp-dentin regeneration scaffold" and "pulp-dentin complex regeneration" were used. To locate additional reports, reference mining of the identified papers was undertaken. Results: A wide variety of biomaterials is already available for tissue engineering and can be broadly categorized into two groups: (i) natural, and (ii) synthetic, scaffolds. Natural scaffolds often contain bioactive molecules, growth factors, and signaling cues that can positively influence cell behavior. These signaling molecules can promote specific cellular responses, such as cell proliferation and differentiation, crucial for effective tissue regeneration. Synthetic scaffolds offer flexibility in design and can be tailored to meet specific requirements, such as size, shape, and mechanical properties. Moreover, they can be functionalized with bioactive molecules, growth factors, or signaling cues to enhance their biological properties and the manufacturing process can be standardized, ensuring consistent quality for widespread clinical use. Conclusions: There is still a lack of evidence to determine the optimal scaffold composition that meets the specific requirements and complexities needed for effectively promoting dental pulp tissue engineering and achieving successful clinical outcomes. [ABSTRACT FROM AUTHOR]
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- 2024
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13. Cyclic fatigue resistance of three rotary file systems in a dynamic model after immersion in sodium hypochlorite
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Palma, Paulo Jorge, Messias, Ana, Cerqueira, António Rosa, Tavares, Luís Diogo, Caramelo, Francisco, Roseiro, Luís, and Santos, João Miguel
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- 2019
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14. Biocompatibility, Biomineralization and Induction of Collagen Maturation with the Use of Calcium Hydroxide and Iodoform Intracanal Dressing.
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Bueno, Carlos Roberto Emerenciano, Sarmiento, Jimena Lama, Vasques, Ana Maria Veiga, da Silva, Ana Cláudia Rodrigues, Cintra, Luciano Tavares Angelo, Santos, João Miguel Marques, and Dezan-Júnior, Eloi
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BIOMINERALIZATION ,CALCIUM hydroxide ,STAINS & staining (Microscopy) ,COLLAGEN ,BIOCOMPATIBILITY ,PROPYLENE glycols - Abstract
Biocompatibility and biomineralization of root canal dressings are important requirements for periapical healing. This study evaluated the inflammatory response, biomineralization and tissue repair by collagen fiber maturation in the subcutaneous tissue of rats. Eighteen Wistar rats (n = 6) received subcutaneous implants: calcium hydroxide + propylene glycol [CH+P], calcium hydroxide + propylene glycol + iodoform [CH+P+I], iodoform + carbowax [I+Cwax] and carbowax [Cwax]. Extra empty tubes were used as a control [C]. After 7, 15 and 30 days, the implants were removed with surrounding tissue for staining of hematoxylin-eosin, Von Kossa, picrosirius red and without staining for analysis under polarized light. Results were analyzed via Kruskal–Wallis followed by Dunn testing for nonparametric data and ANOVA followed by a Tukey post hoc test for parametric data (p < 5%). At 7 days, all groups showed a moderate inflammatory reaction and thick fibrous capsule, except the [Cwax] group, with a severe inflammatory infiltrate (p < 0.05). After 15 days, all groups but control had a decrease in inflammatory response. At 30 days, all groups presented a mild reaction and thin fibrous capsule (p > 0.05). Only groups containing calcium hydroxide were found to be positive using Von Kossa staining and polarized light in all periods. At 7 days, all groups showed a higher proportion of immature fibers. At 15 days, the [CH+P] and [Cwax] groups increased their proportion of mature/immature fibers. At 30 days, only the [CH+P] group presented a significant prevalence of mature collagen fibers (p < 0.05). All groups showed biocompatibility, but only groups containing calcium hydroxide induced biomineralization. The addition of iodoform delayed tissue healing. [ABSTRACT FROM AUTHOR]
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- 2023
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15. 1-year In Vitro Evaluation of Tooth Discoloration Induced by 2 Calcium Silicate–based Cements
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Ramos, João Carlos, Palma, Paulo J., Nascimento, Rita, Caramelo, Francisco, Messias, Ana, Vinagre, Alexandra, and Santos, João Miguel
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- 2016
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16. A Novel Genetic Variant in MBD5 Associated with Severe Epilepsy and Intellectual Disability: Potential Implications on Neural Primary Cilia.
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Martins, Mariana, Oliveira, Ana Rafaela, Martins, Solange, Vieira, José Pedro, Perdigão, Pedro, Fernandes, Ana Rita, de Almeida, Luís Pereira, Palma, Paulo Jorge, Sequeira, Diana Bela, Santos, João Miguel Marques, Duque, Frederico, Oliveira, Guiomar, Cardoso, Ana Luísa, Peça, João, and Seabra, Catarina Morais
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INTELLECTUAL disabilities ,CILIA & ciliary motion ,GENETIC variation ,EPILEPSY ,NEURAL development - Abstract
Disruptions in the MBD5 gene have been linked with an array of clinical features such as global developmental delay, intellectual disability, autistic-like symptoms, and seizures, through unclear mechanisms. MBD5 haploinsufficiency has been associated with the disruption of primary cilium-related processes during early cortical development, and this has been reported in many neurodevelopmental disorders. In this study, we describe the clinical history of a 12-year-old child harboring a novel MBD5 rare variant and presenting psychomotor delay and seizures. To investigate the impact of MBD5 haploinsufficiency on neural primary cilia, we established a novel patient-derived cell line and used CRISPR-Cas9 technology to create an isogenic control. The patient-derived neural progenitor cells revealed a decrease in the length of primary cilia and in the total number of ciliated cells. This study paves the way to understanding the impact of MBD5 haploinsufficiency in brain development through its potential impact on neural primary cilia. [ABSTRACT FROM AUTHOR]
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- 2023
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17. Low-Level Laser Therapy for the Treatment of Oral Mucositis Induced by Hematopoietic Stem Cell Transplantation: A Systematic Review with Meta-Analysis.
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Franco, Rocco, Lupi, Ettore, Iacomino, Enzo, Galeotti, Angela, Capogreco, Mario, Santos, João Miguel Marques, and D'Amario, Maurizio
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MUCOSITIS ,PHOTOBIOMODULATION therapy ,HEMATOPOIETIC stem cell transplantation ,STEM cell transplantation ,LASER therapy ,LITERATURE reviews - Abstract
Oral mucositis is a common and debilitating side effect induced by stem cell transplantation that is experienced by cancer patients undergoing chemotherapy or radiation therapy. This condition involves inflammation and ulceration of the oral mucosa, leading to pain, difficulty with eating and speaking, and an increased risk of infections. Mucositis not only compromises the quality of life for cancer patients, but also affects treatment outcomes and may necessitate dose reductions or treatment delays. This scientific article provides a comprehensive overview of mucositis. The purpose of this literature review with a meta-analysis is to evaluate the efficacy of laser therapy in treating post-transplant mucositis. Materials and methods: A search of the literature from 3 May 2023 was carried out on three online databases, PubMed, Scopus, and Web of Science. Only studies that treated patients with laser therapy were considered; only studies with the placebo-treated control group were considered. Review Manager version 5.2.8 (Cochrane Collaboration) was used for the pooled analysis. We measured the std. mean difference between the two groups (laser and placebo). Results: There were 230 papers included in this review. Two hundred twenty-seven were excluded. Furthermore, a manual search was performed. After the search phase, three articles were considered in the study. The overall effect showed differences in the degree of mucositis in the laser-treated patients compared with the placebo group. The meta-analysis shows a reduction in the degree of mucositis in the patients treated with laser therapy (std. mean difference −1.34 [−1.98; −0.98]; C.I. 95%). Conclusions: The application of laser therapy results in decreased severity of oral mucositis from radiation and chemotherapy. Our study shows that the application of low-level laser therapy in the treatment of transplant mucositis has excellent efficacy in relieving the symptoms and severity of mucositis. [ABSTRACT FROM AUTHOR]
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- 2023
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18. Efficient Lossless Coding of Light Fields for Medical Imaging Systems
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Santos, João Miguel Pereira da Silva, Cruz, Luís, Faria, Sérgio, and Assunção, Pedro
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Efficient Light Field Representation formats ,Compressão de Light Fields ,Compressão de Imagens Médicas ,Compressão sem Perdas ,Formatos Eficientes para Representação de Light Fields ,Engenharia e Tecnologia::Engenharia Eletrotécnica, Eletrónica e Informática [Domínio/Área Científica] ,Light Field Coding ,Lossless Coding ,Minimum Rate Predictors - Abstract
Tese de Doutoramento em Engenharia Eletrotécnica e de Computadores, Ramo de Especialização em Telecomunicações, apresentada à Faculdade de Ciências e Tecnologia da Universidade de Coimbra. The adoption of light field technology is often hindered by the large amount of data necessary to represent such information. In particular, applications with strict quality requirements call for compressed representations that can preserve the integrity of the original data captured from the visual scene. Such is the case of medical images which, due to technical and legal reasons, need to be archived with no quality loss. In this context, this thesis investigates efficient algorithms for lossless compression of light fields, in particular those acquired in a medical setting, using the MRP encoder as the basis framework for new solutions. The research work carried out within the scope of this thesis has produced three main contributions. The first one comprises pre-processing methods to ease the compression of light fields using standard-compliant and other state-of-the-art image/video lossless codecs available in the literature. A simulation study is presented, using generic image and video codecs, including MRP, HEVC, JPEG-LS, JPEG 2000, and CALIC, to assess the coding of light fields with various data arrangements. The results of this study show that encoding light field in a pseudo-video sequence arrangement is an efficient approach. The pre-processing algorithms developed in this research are shown to greatly improve the compression ef ficiency of four-dimensional transform based encoders, such as MuLE, specially in the cases where they are less efficient in comparison with the other standard light field en coder WaSP, i.e., in light fields with higher disparity. The second contribution consists in new algorithms, based on the MRP encoder, to ef ficiently exploit the redundancies present in the four-dimensional light field structure. These algorithms, named as 4D-MRP, DT-4D-MRP, and M-MRP, employ four-dimen sional prediction and data partitioning to fully exploit the inherent spatial and angular redundancies of the four-dimensional light field representation. The proposed algorithms largely surpass previous state-of-the-art lossless encoders, including those specifically tailored for light field coding. The third contribution proposes a hierarchical codec optimised for light fields that can trade-off compression efficiency for other functionalities like angular scalability and ran dom access. The enhanced capabilities of the this encoder, named as H-MRP, are expected to help the faster adoption of this technology, by allowing compatibility with legacy dis plays and easier navigation through light field viewpoints. The H-MRP encoder is highly configurable, and is able to surpass state-of-the-art methods both in terms of compression efficiency and its random access capabilities. Overall, the advances in lossless light field coding presented in this thesis demonstrate that the proposed methods achieve the best compression efficiency in comparison to other solutions available in the literature. Therefore these contributions establish a new state of-art in lossless light field coding. A adopção da tecnologia light field é dificultada pela grande quantidade de dados neces sários para a sua representação. Em particular, aplicações com requisitos de qualidade rigorosos exigem formatos de representação comprimidos que possam preservar a integri dade dos dados originais capturados de uma cena. Este é o caso das imagens médicas que, por razões técnicas e legais, necessitam de ser arquivadas sem perda de qualidade. Neste contexto, esta tese investiga algoritmos eficientes para compressão sem perdas de light fields, em particular aqueles adquiridos em ambientes médicos, utilizando o codi ficador MRP como base para as novas soluções propostas. O trabalho de investigação desenvolvido no contexto desta tese resultou em três contribuições principais. A primeira envolve métodos de pré-processamento que facilitam a codificação de light fields utilizando codificadores de imagem/vídeo genéricos do estado da arte disponíveis na literatura. Um estudo experimental é apresentado, onde se usam codecs genéricos de imagem e vídeo, incluindo MRP, HEVC, JPEG-LS, JPEG 2000 e CALIC, para avaliar a codificação de light fields com vários arranjos de dados. Os resultados deste estudo mostram que codificar light fields reorganizados numa pseudo-sequência de vídeo é uma abordagem eficiente. Os algoritmos de pré-processamento desenvolvidos nesta pesquisa demonstraram melhorar bastante a eficiência de compressão de codificadores baseados em transformadas tetradimensionais, como o MuLE, especialmente nos casos onde são menos eficientes quando comparados com o outro codificador padrão de light field, WaSP, i.e., em light fields com maior disparidade. A segunda contribuição consiste em novos algoritmos, baseados na abordagem do MRP, para explorar de forma eficiente as redundâncias presentes na estrutura tetradimensional dos light fields. Estes algoritmos, denominados de 4D-MRP, DT-4D-MRP e M-MRP, uti lizam predição e partição tetradimensional dos dados para explorar de forma abrangente as redundâncias espaciais e angulares inerentes à representação tetradimensional de light fields. Os resultados obtidos com os algoritmos propostos ultrapassam largamente aqueles dos anteriores codificadores sem perdas do estado da arte, incluindo os especificamente adaptados para a codificação de light fields. A terceira contribuição propõe um codec optimizado para a codificação hierárquica de light fields que pode sacrificar a eficiência de compressão por outras funcionalidades como a escalabilidade angular e o acesso aleatório. É esperado que as capacidades avançadas deste codificador, denominado H-MRP, ajudem a adopção mais rápida desta tecnologia, permitindo a compatibilidade com ecrãs antigos e navegação mais fácil dos diversos pontos de vista presentes no light field. O codificador H-MRP é altamente configurável, e é capaz de superar métodos do estado da arte quer em termos de eficiência de compressão, quer nas suas capacidades de acesso aleatório. Em geral, os avanços na codificação sem perdas de light fields apresentados nesta tese demonstram que os métodos propostos atingem a melhor eficiência de compressão em comparação com outras soluções disponíveis na literatura. Por conseguinte, estas contri buições estabelecem um novo estado da arte em matéria de codificação sem perdas de light fields. This work was supported by the Fundação para a Ciência e a Tecnologia (FCT), Portugal, under PhD Grant SFRH/BD/114894/2016, project DermoPleno (PEst-OE/EEI/LA0008/2016), project PlenoISLA (POCI-01-0145-FEDER-028325), the Advanced Computing Project (CPCA/A00/6782/2020) through the MACC Bob cluster, and by FCT/MCTES through national funds and when applicable co-funded by EU funds under the project UIDB/EEA/50008/2020. This work was also supported by Instituto de Telecomunicações.
- Published
- 2022
19. Long-Term Outcome of Nonvital Immature Permanent Teeth Treated With Apexification and Corono-Radicular Adhesive Restoration: A Case Series
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Santos, João Miguel, Diogo, Patrícia, Dias, Sónia, Marques, Joana A., Palma, Paulo J., and Ramos, João Carlos
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- 2022
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20. In vitro evaluation of the efficacy of diferente protocols on calcium hydroxide dressing removal
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Teles,Ana Moura, Reis,Tiago, Remoaldo,Marina, Santos,António Múrias dos, Santos,João Miguel, and Guimarães,Duarte Antunes
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Disinfection ,Calcium hydroxide ,Root canal irrigants ,Ultrasonic therapy ,Endodontics - Abstract
Objective: To compare in vitro irrigation systems’ efficacy in removing calcium hydroxide paste (Ca(OH)2) in single-root teeth. Methods: Sixty permanent teeth were prepared using ProTaper® rotatory instruments, up to F3. Specimens were split longitudinally into two halves, and two grooves located in the apical and coronal zones were created. Ca(OH)2 application into the grooves was assessed by radiographic and photographic methods. After the halves were reassembled in a silicone mold, teeth were randomly divided into experimental groups (n=15), testing Ca(OH)2 removal: 1 - CanalBrush™; 2 - E1 - Irrisonic tip; 3 - manual dynamic irrigation (MDI); 4 - XP-endo Finisher® (XP). A total volume of 10 mL of 2.5% sodium hypochlorite was used in each tooth. Finally, all groups were scored regarding the Ca(OH)2 remnants using the same methods as before. Statistical analysis was conducted using the Kruskal-Wallis test followed by Mann-Whitney U tests (with Bonferroni correction). A value of p
- Published
- 2021
21. Intentional Replantation as a Starting Approach for a Multidisciplinary Treatment of a Mandibular Second Molar: A Case Report.
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Santos, João Miguel, Marques, Joana A., Esteves, Margarida, Sousa, Vítor, Palma, Paulo J., and Matos, Sérgio
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PERIAPICAL diseases , *CONE beam computed tomography , *MANDIBULAR nerve , *PERIAPICAL periodontitis , *PERIODONTAL pockets , *ALVEOLAR process - Abstract
Intentional replantation (IR) may offer a solution for persistent periapical lesions associated with endodontically treated teeth. A 35-year-old male patient presented with pain associated with the left mandibular second molar and hypoesthesia. Upon clinical examination, increased probing pocket depth in the mid-buccal surface was detected. Cone beam computed tomography revealed a previous non-surgical root canal treatment, with root canal filling material extrusion adjacent to the inferior alveolar nerve, a fractured instrument in the mesial root, and a large periapical radiolucency involving both teeth 37 and 36. A diagnosis of symptomatic post-treatment apical periodontitis was established. After discussing treatment options with the patient, an IR of tooth 37 was performed. Extra-oral procedures were completed in 17 min. At 9 months, hypoesthesia resolution was reported, and apical healing was radiographically observed. After 2.5 years, the replanted tooth showed extensive root resorption. An extraction with alveolar ridge preservation, using leukocyte-platelet rich fibrin (L-PRF), was performed. Six months after tooth extraction and regeneration, implant placement surgery was carried out. IR presents a valid treatment modality for the management of post-treatment apical periodontitis. When orthograde retreatment or apical microsurgery prove to be unfeasible, IR is a unique procedure with the potential to promote tooth preservation in properly selected cases. Although unsuccessful after 2.5 years, the IR of tooth 37 allowed for bone regeneration, the maintenance of tooth 36 vitality, and hypoesthesia resolution. [ABSTRACT FROM AUTHOR]
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- 2022
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22. Delayed Cutaneous Adverse Reaction of the AstraZeneca COVID-19 Vaccine in a Breastfed Female Infant: A Coincidence or a Rare Effect?
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Diogo, Patrícia, Correia, Gil, Martins, João B., Soares, Rui, Palma, Paulo J., Santos, João Miguel, and Gonçalves, Teresa
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COVID-19 vaccines ,INFANTS ,COINCIDENCE ,MOTHER-infant relationship ,EXANTHEMA ,ANKYLOGLOSSIA - Abstract
The ChAdOx1 nCoV-19 vector vaccine (Vaxzevria, AstraZeneca, Cambridge, UK) was developed at Oxford University and is considered safe for the administration in lactating mothers. Nevertheless, as a novel vaccine, there are gaps in the knowledge regarding possible adverse events in breastfeeding infants of vaccinated mothers. This case report provides first-time data on a possible delayed, cutaneous, adverse reaction in a breastfed, 16-month-old female infant after the first administration of the AstraZeneca vaccine to her 33-year-old mother. Even though, no clinical adverse effects were observed in the mother, her daughter had a 2-day rash in the lower extremities and face. The infant's cutaneous rashes might be a coincidental event. However, all skin lesions were analogous to previous descriptions and photographs of dermatologic reactions, which resolved spontaneously with no medical intervention, in people who had been vaccinated with other COVID-19 vaccines. Our aim is that this short report contributes to the enhancement of parental awareness about the possibility of similar skin rashes in breastfed children when the mothers receive a vaccination and the importance of reporting those adverse reactions to the competent authorities. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
23. Digital compensation of fiber impairments in long-haul optical communication systems
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Santos, João Miguel Pereira, Monteiro, Paulo, and Guiomar, Fernando
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Optical communications systems ,Impairment mitigation ,Artificial neural networks ,Coherent detection ,Digital signal processing - Abstract
The continuous increase of traffic demand in long-haul communications motivated the network operators to look for receiver side techniques to mitigate the nonlinear effects, resulting from signal-signal and signal-noise interaction, thus pushing the current Capacity boundaries. Machine learning techniques are a very hot-topic with given proofs in the most diverse applications. This dissertation aims to study nonlinear impairments in long-haul coherent optical links and the current state of the art in DSP techniques for impairment mitigation as well as the integration of machine learning strategies in optical networks. Starting with a simplified fiber model only impaired by ASE noise, we studied how to integrate an ANN-based symbol estimator into the signal pipeline, enabling to validate the implementation by matching the theoretical performance. We then moved to nonlinear proof of concept with the incorporation of NLPN in the fiber link. Finally, we evaluated the performance of the estimator under realistic simulations of Single and Multi- Channel links in both SSFM and NZDSF fibers. The obtained results indicate that even though it may be hard to find the best architecture, Nonlinear Symbol Estimator networks have the potential to surpass more conventional DSP strategies. O aumento contínuo de tráfego nas comunicações de longo-alcance motivou os operadores de rede a procurar técnicas do lado do receptor para atenuar os efeitos não lineares resultantes da interacção sinal-sinal e sinal-ruído, alargando assim os limites da capacidade do sistema. As técnicas de aprendizagem-máquina são um tópico em ascenção com provas dadas nas mais diversas aplicações e setores. Esta dissertação visa estudar as principais deficiências nas ligações de longo curso e o actual estado da arte em técnicas de DSP para mitigação das mesmas, bem como a integração de estratégias de aprendizagem-máquina em redes ópticas. Começando com um modelo simplificado de fibra apenas perturbado pelo ruído ASE, estudámos como integrar um estimador de símbolos baseado em ANN na cadeia do prodessamento de sinal, conseguindo igualar o desempenho teórico. Procedemos com uma prova de conceito perante não linearidades com a incorporação do ruído de fase não linear na propagação. Finalmente, avaliamos o desempenho do estimador com simulações realistas de links Single e Multi canal tanto em fibras SSFM como NZDSF. Os resultados obtidos indicam que apesar da dificuldade de encontrar a melhor arquitectura, a estimação não linear baseada em redes neuronais têm o potencial para ultrapassar estratégias DSP mais convencionais. Mestrado em Engenharia Eletrónica e Telecomunicações
- Published
- 2020
24. Compensação digital de distorções da fibra em sistemas de comunicação óticos de longa distância
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Santos, João Miguel Pereira, Monteiro, Paulo, and Guiomar, Fernando
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Optical communications systems ,Impairment mitigation ,Artificial neural networks ,Coherent detection ,Digital signal processing - Abstract
Submitted by Manuel Jesus (albertojesus@ua.pt) on 2020-10-22T15:06:19Z No. of bitstreams: 1 Documento_João Miguel Pereira Santos.pdf: 12328974 bytes, checksum: b3f4dbe346981f15365142ab7efcf638 (MD5) Made available in DSpace on 2020-10-22T15:06:19Z (GMT). No. of bitstreams: 1 Documento_João Miguel Pereira Santos.pdf: 12328974 bytes, checksum: b3f4dbe346981f15365142ab7efcf638 (MD5) Previous issue date: 2020-07-30 Mestrado em Engenharia Eletrónica e Telecomunicações
- Published
- 2020
25. Iatrogenic Complications During the Diagnostic Work-Up of an Inflammatory Cardiomyopathy
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Antunes, Hugo, Gil, Júlio, Marmelo, Bruno, Gonçalves, Maria Luísa, Pires, Maria Inês, Santos, João Miguel, Correia, Miguel, and Cabral, José Costa
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Cardiomyopathy, Dilated ,Hypertension ,Diabetes Mellitus ,Endocardites ,Spectroscopy, Magnetic Resonance/methods ,Cardiomyopathies ,Iatrogenic Disease/complications - Abstract
A 72-year-old woman was admitted for acute heart failure. The echocardiography revealed moderate depression of the left ventricular ejection fraction. Coronary disease was excluded by coronarography. Cardiac magnetic resonance showed predominantly left ventricular septal hypertrophy and severe depression of the left ventricular systolic function. There was also a bright, multifocal and patchy late gadolinium enhancement with subendocardial, mesocardial and subepicardial involvement, suggestive of sarcoidosis. Biochemical study, thoracic computed tomography and positron emission tomography were inconclusive for extra-cardiac sarcoidosis. Therefore, an endomyocardial biopsy was performed. The procedure was complicated by the development of complete atrioventricular block, requiring implantation of a cardiac resynchronization pacing device. A few days after device implantation, the patient developed fever. The echocardiography revealed extensive vegetations, and thus the diagnosis of a device-associated infective endocarditis was made. Even though antibiotic therapy was promptly started, the patient ended up dying. Biopsy results revealed lymphocytic myocarditis. This case is paradigmatic because it shows how the etiologic diagnosis of dilated cardiomyopathy can be challenging. Non-invasive diagnostic exams may not provide a definite diagnosis, requiring an endomyocardial biopsy. However, the benefits versus risks of such procedure must always be carefully weighted.
- Published
- 2020
26. Regular physical activity reduces the harmful association of watching television in depression
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Santos, João Miguel Gomes dos and Marques, Adilson Passos da Costa
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European Social Survey ,Desporto ,Adults ,Mental health ,Adultos ,Saúde mental ,Ciências Médicas::Outras Ciências Médicas [Domínio/Área Científica] ,Sport - Abstract
Purpose: This study aimed to analyse the association of watching television (TV), physical activity (PA), and depression; and to understand whether PA attenuates or eliminates the harmful association between TV and depression. Methods: Cross-sectional study based on data from the European Social Survey round 7 (ESS-7), 2014. Sample of 29,285 adults (13,943 men; 15,342 women), aged 50.9±17.4 (50.6±17.3 men, 51.1±17.5 women). TV and PA were self-reported. Depression was assessed with the Center for Epidemiological Studies Depression Scale (CES-D8). To analyse the association between the TV and the CES-D8 score a Univariate Analysis of Variance was used. A linear regression was conducted to analyse the association between the practice of PA and the CES-D8 score. To analyse the effect of TV on the CES-D8 score, according to PA frequency, a Univariate Analysis of Variance was performed. Results: Men and women who watched more than 2h/day of television had higher CES-D8 score; women had a higher a score of depression than men. PA, independently of television viewing time, was inversely associated with depression in men (β = -0.15, 95% CI: (-0.18) – (-0.13)), and women (β = -0.23, 95% CI: (-0.26) – (-0.21)). Men spending 1-2 hours/day TV and engaging in PA ≥5 times per week had the lowest CES-D8 score. The lowest CES-D8 score in women was observed for those engaging 2-4 times/week in PA and spending
- Published
- 2020
27. The science of scientific agendas: insights into the agenda setting process of researchers
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Santos, João Miguel da Costa Sobreiro Marques dos, Horta, Hugo, and Amâncio, Lígia
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Ciências Sociais::Psicologia [Domínio/Área Científica] ,Ensino superior ,2200 Psychometrics, statistics and methodology ,2900 Social processes and social issues ,Estudos em ciência ,Science policy ,Higher education ,3600 Industrial and organizational psychology ,Ciência e tecnologia ,Research agendas ,Agendas científicas ,Science and technology ,Science studies ,Política científica ,3000 Social psychology - Abstract
Even though research agenda-setting is at the core of modern research and development activities, little is known regarding the process that leads to the definition of an agenda. The literature indirectly suggests that a series of both exogenous and endogenous factors may shape the preference of researchers concerning the research agendas they intend on pursuing – such as formal education, hierarchical position, working environment, incentives, scientific drive, creativity, risk tolerance, and personality. However, no study has been conducted in order to formally test these associations comprehensively. This project aims to identify the mechanisms underlying research agenda-setting through a multi-stage, multi-disciplinary approach. To this end, new instruments were developed – one focusing on evaluating the factors that influence research agenda setting, and another focusing on workplace related organizational aspects in the academia. Following this, Cluster Analysis was employed in order to determine the existence of overarching doctrines in terms of research agenda setting, and afterwards we explore how cognition can influence the process of research agenda setting. This was followed by an exploratory study on how the organizational setting influences these dynamics and how research agendas are also gendered. A second, more holistic, comprehensive and optimal revision of the initial research-agendas instrument concludes this project, resulting from lessons learned and knowledge acquired as the thesis was being developed. The thesis concludes with an overall discussion of the findings and its contribution to knowledge advancement, implications for practice and policymaking, and the limitations of the study, as well as an agenda for future studies. Apesar do processo de definição de agendas científicas estar no cerne da investigação e desenvolvimento de hoje em dia, pouco se sabe acerca do processo que leva à definição destas agendas. A literatura indirectamente sugere que uma série de factores endógenos e exógenos moldam a preferência dos investigadores no que toca à agenda de investigação que intencionam seguir – tais como educação formal, posição hierárquica, incentivos, ambição científica, criatividade, tolerância ao risco, e personalidade. No entanto, até à data nenhum estudo foi realizado de forma a formalmente testar estas relações de uma forma compreensiva. Este projecto tem como objectivo identificar os mecanismos subjacentes ao processo de definição de agendas científicas através de uma abordagem multi-fásica e multi-disciplinar. Para este fim, foram desenvolvidos novos instrumentos – um focado na avaliação dos factores que influenciam a definição de agendas científicas, e outro focado nos aspectos organizacionais da academia. De seguida, realizou-se uma análise de clusters de forma a identificar a existência de doutrinas gerais em termos de definição de agendas científicas. Seguiu-se um estudo exploratório relativamente ao contexto organizacional e a sua influência nestas dinâmicas, assim como o efeito do género nas agendas científicas. O projecto conclui com uma revisão mais holística do instrumento original, resultante das lições que foram aprendidas, assim como da informação que foi recolhida ao longo da tese. Esta tese termina com uma discussão geral dos seus resultados e implicações para o avanço do conhecimento, para a prática e desenvolvimento de políticas, assim como uma agenda para estudos futuros.
- Published
- 2019
28. ExoBike : mechanical component development
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Santos, João Miguel Sousa, Roseiro, Luís Manuel Ferreira, and Ferreira, Pedro Miguel Soares
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Membros inferiores ,Reabilitação ,Bicicleta - Abstract
Muitas das vezes o processo de reabilitação é monótono e desmotivador devido à repetibilidade dos exercícios e falta de feedback ou ferramentas que permitam avaliar o progresso. Assim, tendo em conta que o exercício de bicicleta é muito utilizado para a reabilitação dos membros inferiores, foi criado o projeto ExoBike. De modo a combater tais fatores, a ExoBike consiste numa bicicleta equipada com sensores de força nos principais pontos de interação entre bicicleta e paciente. Assim é possível adquirir dados importantes para avaliar o progresso do paciente, bem como estabelecer metas e ajustar os exercícios conforme as necessidades do paciente. Alem desta componente de aquisição de dados, o projeto ExoBike engloba ainda uma vertente de realidade virtual, que junta com a componente de aquisição de dados, proporciona ao paciente uma experiência mais imersiva, tornando assim a prática de exercício para reabilitação mais divertida e motivadora. Este documento foca-se no desenvolvimento dos dispositivos mecânicos instalados na bicicleta para a aquisição dos dados do paciente. Para tal foi desenvolvido um selim capaz de analisar a postura do paciente, um guiador que caracteriza a força que o paciente realiza com os membros superiores, uns pedais capazes de analisar o movimento de pedalada e uns punhos que adquirem a força de preensão que o paciente é capaz de efetuar. Sendo que as metodologias de aquisição de dados dos dispositivos se baseiam em células de carga, extensometria elétrica por resistência e inteligência artificial. Os dispositivos foram desenvolvidos e otimizados com recurso a programas de desenho computacional, analisados através de métodos numéricos e analíticos, ensaiados através de prototipagem rápida com impressão 3D e produzidos com recurso a máquinas de fabrico subtrativo com controlo numérico. De modo a garantir o correto funcionamento dos dispositivos, estes foram sujeitos a uma serie de calibrações e testes funcionais com grupos de 3, 5 e 31 voluntários para corroborar as metodologias adotadas e avaliar as capacidades das mesmas. Sendo que os dipositivos indicaram uma correlação de 0.7, entre a postura do voluntario e a sua altura, e uma correlação elevada de 0.9 entre a massa do voluntario e a força exercida pelos membros inferiores. Entre outro tipo de correlações, os dipositivos foram ainda capazes de determinar, com uma fiabilidade 95%, o efeito de recalcamento psicológico quando os voluntários foram sujeitos a uma reação de defesa induzida nos membros inferiores. Considerando assim, que as metodologias e dispositivos desenvolvidos se encontram mais do que aptos para o objetivo pretendido de avaliação e monitorização do processo de reabilitação dos membros inferiores com recurso a bicicleta estática
- Published
- 2019
29. Hydroxychloroquine-induced cardiomyopathy predominantly affecting the right ventricle.
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Neto, Vanda Devesa, Fiúza, João, Pires, Inês, Santos, João Miguel, and Correia, Miguel
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HYDROXYCHLOROQUINE ,BIOPSY ,CARDIOMYOPATHIES ,SYNCOPE ,LIPIDOSES ,SYSTEMIC lupus erythematosus ,HEART failure ,ELECTROCARDIOGRAPHY ,HEART conduction system ,MYOCARDIUM ,RIGHT heart ventricle ,CARDIAC catheterization ,LYSOSOMAL storage diseases - Published
- 2024
- Full Text
- View/download PDF
30. Thrombus in transit through a patent foramen ovale: catch it if you can—a case report.
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Pires, Maria Inês Fiuza Branco, Almeida, Inês, Santos, João Miguel, and Correia, Miguel
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PATENT foramen ovale ,ATRIAL septal defects ,THROMBOSIS ,CONGENITAL heart disease ,PARADOXICAL embolism ,DIAGNOSIS - Abstract
Background Patent foramen ovale (PFO) is one of the most common congenital heart defects, but the finding of a thrombus in transit (TIT) through a PFO is extremely rare. It is a therapeutic challenge, and systemic anticoagulation, cardiac surgery, or fibrinolysis should be considered. Case summary A 43-year-old woman was admitted with intermediate-high-risk pulmonary embolism. Transthoracic echocardiogram revealed a large right atrial mobile mass that crossed the interatrial septum through a PFO, compatible with TIT, and the patient was started on unfractionated heparin. The diagnosis was confirmed by transoesophageal echocardiogram (TOE). However, during TOE probe removal, the patient developed dyspnoea, sudoresis, and peripheral desaturation, and new image acquisition revealed sudden mass disappearance. Due to the possibility of paradoxical embolization associated with Valsalva manoeuvre, fibrinolysis with alteplase was promptly started. The patient had no signs of embolic or haemorrhagic complications and remained clinically stable. She was discharged on warfarin and then underwent percutaneous transcatheter closure of PFO. Discussion The treatment strategy of a TIT through a PFO is controversial, but surgery might be the most appropriate treatment for haemodynamically stable patients, while thrombolysis should be used in cases of haemodynamic instability. Transoesophageal echocardiogram is generally a safe procedure but pressure changes associated with Valsalva manoeuvre may induce embolization of a TIT and attention should be given to patient sedation and tolerance. After complete embolization of a TIT, emergent thrombolysis may be the only treatment option, in order to prevent disastrous consequences related to paradoxical embolism. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
31. Cited2 in cardiac development: an inside and outside job
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Santos, João Miguel Almeida, Bragança, José, and Futschik, Matthias E.
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WNT11 ,CITED2 ,Células estaminais ,WNT5a ,Defeitos Cardíacos ,Ciências Médicas::Outras Ciências Médicas [Domínio/Área Científica] - Abstract
Despite the remarkable knowledge acquired in the formation of the heart during embryonic development and the molecular mechanisms involved in heart function and physiology, there is no efficient way to prevent adult heart disease and congenital heart disease (CHD). The transcriptional modulator Cited2 is required for normal embryogenesis of mice and humans, particularly for heart development. Indeed, mouse lacking Cited2 alleles die in utero displaying many cardiovascular defects, and mutations in human CITED2 have long been associated with CHD. However, the exact role and the molecular mechanisms involving Cited2 during these processes are largely unknown. Using mouse Embryonic Stem Cells (ESC) as a model system, we have established that the depletion of Cited2 at the onset of differentiation resulted in a decline of ESC ability to generate cardiac cells. These cardiogenic defects in Cited2-depleted cells were rescued by treatment with a recombinant CITED2 protein. To further investigate the mechanisms caused by the loss of Cited2 in pluripotency and differentiation, we compared the gene expression profiles of control cells and Cited2-depleted cells upon differentiation. We determined that loss of Cited2 expression delays the expression of early mesoderm transcription factors and cardiopoietic factors. We found that the secretome of Cited2 overexpressing ESC is enough to restore the emergence of beating colonies in Cited2 depleted cells, upon differentiation. We identified WNT5a and WNT11 as two of the proteins enriched in the Conditioned Medium and crucial for rescuing cardiomyocyte differentiation defects caused by Cited2 depletion. Our results point that Cited2 is a co-transcriptional activator of Wnt5a and Wnt11 and that both proteins can restore cardiogenesis in Cited2-depleted cells. Additionally, using zebrafish as a model system, we demonstrated that WNT5a and WNT11 also rescued the development defects caused by Cited2 depletion in vivo. Collectively, our results show that WNT5a and WNT11 rescue cardiogenic defects caused by Cited2 depletion both in vitro, as well as in vivo. Apesar do notável conhecimento adquirido sobre o desenvolvimento cardíaco, as doenças cardiovasculares e as doenças congénitas cardíacas (CHD), continuam a ser a principal causa de morte no mundo tanto nos adultos como em recém-nascidos. Estima-se que cerca de 1% da população mundial seja portadora de uma forma de CHD e, espera-se que este número aumente substancialmente nas próximas décadas. Um ponto crucial do desenvolvimento cardíaco é a expressão primorosamente controlada de fatores de transcrição e vias de sinalização cardíacas. Pequenos desvios na estrita expressão de fatores de transcrição e das vias de sinalização cardíacas, podem resultar num mau desenvolvimento do coração e no aparecimento de CHD, ou em casos mais extremos à morte do embrião ainda no útero. Dentro dos fatores de transcrição importantes para a formação do coração destacam-se inicialmente os genes importantes para a regulação da pluripotência OCT4, SOX2 e NANOG. Após a gastrulação, as células da mesoderme começam inicialmente a expressar BRACHYURY, MIXL1 e EOMES, e mais tarde o gene da mesoderme cardiaca MESP1. Por último, os progenitores cardíacos começam a expressar os fatores de transcrição cardíacos GATA4, NKX2.5, HAND2, TBX5, MEF2C e ISL1. As principais vias de sinalização cardíacas são a ACTIVIN/NODAL e as BMP, ambas pertencentes à via TGFβ, a via canónica e não canónica da WNT e por último, a via FGF. Um ótimo modelo, in vitro, para se estudar os mecanismos moleculares, responsáveis pela formação do coração, são as células estaminais embrionárias (ESC). Algumas das características que tornam as ESC um bom modelo para estudar o desenvolvimento cardíaco são, o fato de se dividirem indefinidamente e de se diferenciarem em todas as células do adulto, após o correto estímulo, incluindo cardiomiócitos com a capacidade de produzirem focos de contração. O fator de transcrição Cited2, é importante para o desenvolvimento cardíaco, uma vez que a remoção de ambos os alelos de Cited2 no ratinho é letal ainda no útero, enquanto que mutações pontuais na proteína CITED2 foram previamente associadas com o aparecimento de CHD. No entanto, a função de CITED2 no desenvolvimento cardíaco e no aparecimento das CHD é ainda bastante desconhecida. Como tal, o objetivo deste trabalho foi estudar o papel de Cited2 durante o processo de diferenciação cardíaco de ESC. Para estudar o efeito de depleção de Cited2, durante a diferenciação cardíaca, utilizamos no laboratório uma linha de ESC com “Knock-out” condicional de Cited2, que quando suplementado com 4-hydroxytamoxifen, no meio de cultura, resulta na excisão e depleção de Cited2. Começamos por ver que Cited2 é expresso ao longo do processo de diferenciação cardíaca, sendo a sua expressão mínima no dia 2 de diferenciação. De seguida, vimos que a depleção de Cited2, no início da diferenciação, reduz a capacidade das ESC de se diferenciarem em cardiomiócitos. Para demonstrar que os defeitos cardíacos eram causados pela falta de Cited2, tratámos as ESC com uma proteína recombinante CITED2. Os resultados obtidos indicam que esta proteína reverte os defeitos cardíacos quando adicionado no segundo dia de diferenciação. Para perceber melhor os mecanismos subjacentes à perda de função de CITED2, comparámos o perfil genético de células controlo (com Cited2) e células sem Cited2 no início da diferenciação. Neste sentido, realizámos uma análise de “microarrays”, e observámos que as células sem Cited2 têm vários genes, importantes para a diferenciação em endoderme e mesoderme desregulados. Comprovámos que a depleção de Cited2 atrasa a expressão de fatores de transcrição da mesoderme (Brachyury, Mixl1) e da mesoderme cardíaca (Mesp1 e Eomes). Observámos também, que a depleção de Cited2 inibe a expressão de várias vias de sinalização cardíacas, o que nos fez colocar a hipótese de que a deficiência cardíaca, causada pela falta de Cited2, resultaria da desregulação da expressão de proteínas extracelulares. Para o estudo de proteínas extracelulares considerámos o uso de Meio Condicionado (CM), ou seja, recorremos ao meio de cultura que contém, entre vários componentes, proteínas secretadas pelas células (secretoma). Portanto, através do secretoma de ESC, que sobre expressam Cited2, observámos que este é suficiente para recuperar os defeitos cardíacos causados pela falta de Cited2. Vimos também que o CM é crítico para a correta expressão do fator de transcrição Brachyury. Ao imunoprecipitarmos o CM contra WNT5a e WNT11, seguido de um Western Blot, identificámos que as proteínas WNT5a e WNT11 se encontravam enriquecidas no CM proveniente das células que sobre expressavam Cited2. Vimos também que estas duas proteínas eram críticas no CM, uma vez que quando as depletavámos, víamos que o CM perdia a sua capacidade de recuperar os defeitos cardiovasculares das células sem Cited2. A WNT5a e a WNT11 são duas proteínas pertencentes à via não canónica da WNT e que cooperam para promover o desenvolvimento cardíaco, mais propriamente, para promover a formação do campo secundário cardíaco. Os nossos resultados, in vitro, apontam para que Cited2 seja um co-ativador transcricional do Wnt5a e do Wnt11. Mostrámos, que existe uma sinergia entre a WNT5a e WNT11 para corrigir os defeitos cardíacos causados pela falta de Cited2 in vitro, não só em termos de diferenciação celular e surgimento de focos de contração, mas também para a correta expressão de fatores de transcrição da mesoderme e da mesoderme cardiaca. Adicionalmente, para estudar a perda de função de Cited2 in vivo, estabelecemos um sistema de “Knockdown” de Cited2 no peixe zebra (Danio renio). Cited2, é um gene conservado entre os vertebrados e, portanto, tal como acontece nos mamíferos, Cited2 é necessário para o correto desenvolvimento do peixe zebra. Através das experiências realizadas, vimos que a falta de Cited2 atrasa o desenvolvimento dos embriões às 24 horas pós fertilização (hpf), reduz o número de batimentos médio por minuto às 48 hpf e, causa letalidade e o surgimento de defeitos cardíacos em embriões de peixe zebra às 72hpf. Demonstrámos que estes defeitos eram específicos de Cited2, uma vez que conseguimos recuperar a maioria dos defeitos causados pela falta de Cited2, quando usámos a proteína recombinante CITED2. Por último, como acontece in vitro, a combinação da WNT5a e da WNT11 é capaz de compensar a falta de Cited2, também, in vivo. Em suma, os nossos resultados indicam que a WNT5a e a WNT11 corrigem, in vitro e in vivo, os defeitos cardíacos causados pela perda de Cited2, sendo o nosso objetivo, no futuro, desenvolver uma nova opção terapêutica para reduzir o número de pacientes com CHD. ProRegeM PhD Programme (PD/00117/2012).
- Published
- 2019
32. Feasibility evaluation of an RPA implementation in siemens healthineers internal controls
- Author
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Santos, João Miguel Sousa and Major, maria João
- Subjects
RPA ,Internal controls ,Medical technology companies ,Ciências Sociais::Economia e Gestão [Domínio/Área Científica] ,Internal audit - Abstract
The present Working Project aims at studying the topic of Robot Process Automation (RPA) in a specific organizational context of a medical technology company. For this purpose, a time feasibility test was designed to help support the decision, as a first stage, of implementing the aforementioned technology in internal controls. In the end, the test was successfully applied for two internal controls that performed monthly, by the HUB for internal audit purposes. Although the fully operationalization of the RPA itself proved not to be possible during the project’s timespan, it is expected to occur in the approaching future.
- Published
- 2019
33. Impact of Periodontal Attachment Loss on the Outcome of Endodontic Microsurgery: A Systematic Review and Meta-Analysis.
- Author
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Sarnadas, Margarida, Marques, Joana A., Baptista, Isabel Poiares, and Santos, João Miguel
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ENDODONTICS ,MICROSURGERY ,PERIODONTIUM ,CLINICAL trials ,APICOECTOMY - Abstract
Background and Objectives: Endodontic microsurgery (EMS) aims to eradicate the sources of infection once the apical root resection removes most of the infected anatomical structures and repairs potential procedural errors in the apical region. An endodontic-periodontal lesion yields a pathological communication between the pulp and the periodontium. The purpose of this systematic review and meta-analysis is to evaluate the impact of periodontal attachment loss on the outcome of teeth submitted to EMS. Materials and Methods: PRISMA guidelines were followed. An electronic search was performed in EBSCOhost, Embase and PubMed databases with the following search key: (“endodontic microsurgery” AND “outcome”). No filters were used concerning the year of publication or language. Only randomized clinical trials, prospective and retrospective clinical studies in humans, with a minimum one-year follow-up, defined clinical and radiographic outcome criteria and estimable success rate for endodontic-periodontal lesion were included. Statistical analysis was performed using Open Meta[Analyst] software. Results: Of a total of 113 articles, 34 were selected for full-text reading after duplicates deletion and title and abstract analysis. Thirteen and six studies were included in the systematic review and meta-analysis, respectively. A total of 2775 pooled teeth were submitted to EMS, of which 492 teeth and 4 roots had periodontal involvement. According to the qualitative analysis, success rates of the endodontic-periodontal group ranged from 67.6% to 88.2%. Meta-analysis revealed that the absence of periodontal attachment loss was predictive of a higher likelihood of success with an odds ratio of 3.14. Conclusions: Periodontal attachment loss presents a risk factor for EMS outcome. Although endodontic-periodontal lesions were associated with lower success rates considering a 1 to 10 years follow-up period, long-term successful prognosis following EMS has been reported, therefore presenting a fully valid and viable therapeutic option for the management of this type of lesions. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
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34. Influence of Blood Contamination on Push-Out Bond Strength of Three Calcium Silicate-Based Materials to Root Dentin.
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Paulo, Cristina Rodrigues, Marques, Joana A., Sequeira, Diana B., Diogo, Patrícia, Paiva, Rui, Palma, Paulo J., and Santos, João Miguel
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BOND strengths ,GUTTA-percha ,DENTIN ,CALCIUM ,FILLER materials ,DENTAL pulp cavities ,DENTAL adhesives ,TEETH - Abstract
A proper bond between root canal filling materials and dentin surface is essential to resist dislodgement and guarantee long-term success. Blood exposure is likely to occur in various clinical situations in which calcium silicate-based materials are used; therefore, it is fundamental to render data concerning the influence of blood on bond strength. The present study aims to evaluate the effect of blood contamination on the push-out bond strength obtained with three different biomaterials to root canal dentin; Ninety extracted human mono-radicular permanent teeth were selected. The root canals were prepared with Gates Glidden burs until a diameter of 1.10 mm was achieved. Teeth were then randomly divided into six experimental groups (n = 15) according to the presence/absence of blood contamination and biomaterial used for root canal filling (ProRoot
® MTA, BiodentineTM , and TotalFill® BC Putty). After one week, each root was sectioned in three segments (coronal, middle, and apical regions). Specimens were then submitted to push-out bond strength tests. Fracture pattern evaluation was performed. The significance level was set at 5%.; Blood contamination did not affect the push-out bond strength of any of the three tested calcium silicate-based cements (p > 0.05). Regardless of blood contamination, TotalFill showed statistically higher push-out bond strength when compared with Biodentine (p = 0.040) and MTA (p = 0.004). Biodentine exhibited higher bond strength than MTA (p = 0.043). Biomaterials' comparison within each radicular segment revealed statistically superior bond strength of both Biodentine and TotalFill over MTA (p < 0.05) in the coronal segment. TotalFill presented higher push-out bond strength regarding the apical segment compared to Biodentine (p = 0.003). Fractures were mostly adhesive.; Overall results indicate TotalFill presents the highest push-out bond strength values, followed by Biodentine and, lastly, MTA. Blood contamination did not affect the dislodgement resistance. Biomaterials' comparison within each radicular segment revealed both TotalFill and Biodentine as the preferable alternatives for application in the coronal region. TotalFill might be the biomaterial of choice for placement in the apical region. [ABSTRACT FROM AUTHOR]- Published
- 2021
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35. Vital Pulp Therapy in Permanent Mature Posterior Teeth with Symptomatic Irreversible Pulpitis: A Systematic Review of Treatment Outcomes.
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Santos, João Miguel, Pereira, Joana F., Marques, Andréa, Sequeira, Diana B., and Friedman, Shimon
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PULPITIS ,ROOT canal treatment ,PULPOTOMY ,HEMOSTASIS ,SYSTEMATIC reviews - Published
- 2021
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36. Tooth Discoloration after Regenerative Endodontic Procedures with Calcium Silicate-Based Cements—An Ex Vivo Study.
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Palma, Paulo J., Marques, Joana A., Santos, Joana, Falacho, Rui I., Sequeira, Diana, Diogo, Patrícia, Caramelo, Francisco, Ramos, João C., and Santos, João Miguel
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DENTAL discoloration ,TOOTH cervix ,MINERAL aggregates ,CALCIUM ,STATISTICAL significance ,DENTIN - Abstract
The aim of the present ex vivo study was to assess and compare coronal discoloration induced by four endodontic biomaterials used in regenerative endodontic procedures (REPs). Root resection was executed horizontally, 2 mm apical to the cementoenamel junction, in all fifty-four teeth. After accessing the pulp chamber, specimens were randomly divided in groups and filled with either saline solution or blood, followed by calcium silicate-based cements (CSCs) placement: ProRoot mineral trioxide aggregate (MTA) (Dentsply Sirona), Biodentine (Septodont), TotalFill BC (FKG), or pulp capping material (PCM) (Coltène). Color change (ΔE) was assessed using the L* a* b* system at five different timepoints (before and immediately after biomaterial application, 72 h, 7 days, and 6 months). The significance level for statistical analysis was set at p < 0.05. There are statistically significant differences regarding ΔE over time (p < 0.001). Statistical differences are found considering material (p < 0.001), treatment (p = 0.007), or both (p = 0.002). If solely the material or treatment is considered, regardless of time, statistically significant differences are detected (p < 0.001). After a six-month period of evaluation, blood exposure might be a critical factor in biomaterials' color variation. Biodentine presents the lowest discoloration potential, followed by TotalFill and PCM, albeit without statistically significant differences. MTA exhibited the greatest color variation. The selection of biomaterial should consider the material's discoloration potential. [ABSTRACT FROM AUTHOR]
- Published
- 2020
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37. Does Apical Papilla Survive and Develop in Apical Periodontitis Presence after Regenerative Endodontic Procedures?
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Palma, Paulo J., Martins, João, Diogo, Patrícia, Sequeira, Diana, Ramos, João Carlos, Diogenes, Aníbal, and Santos, João Miguel
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PERIAPICAL periodontitis ,ROOT development ,ROOT canal treatment ,MINERAL aggregates ,DENTINAL tubules ,STEM cells ,DENTIN ,POSTOPERATIVE pain - Abstract
Featured Application: The apical papilla can survive and further develop after an endodontic infection. Regenerative endodontic procedures (REPs) have emerged as a treatment option for immature necrotic teeth to allow the reestablishment of a newly formed vital tissue and enable continued root development. The apical papilla stem cells (SCAPs) play an important role in physiologic root development and may also contribute to further root development during REPs. The goal of these case reports is to show evidence of the apical papilla survival and development, in human teeth with apical periodontitis, after REPs, with 5-year clinical and radiographic follow-up. In the first case, an 11-year-old girl with acute apical abscess of tooth 15 was referred for a REP. Treatment was performed with an intracanal medication followed by induction of a blood clot and a Mineral Trioxide Aggregate (MTA) cervical barrier. The 5-year follow-up showed an appreciable increase in root length as well as root canal thickness. In case 2, a 16-year-old girl was referred for endodontic treatment of tooth 21. The parents of the patient recalled a previous dental trauma (no specified on the patient records) on tooth 21 at age 7. The dental history reports a previous endodontic treatment failure and presence of a long-standing sinus tract. A mineralized tissue beyond the root apical portion could be seen at the preoperative X-ray. Nonsurgical root canal retreatment with an apical barrier was suggested as the treatment plan and accepted by the patient. After 2 weeks, the patient was recalled for a follow-up appointment presenting spontaneous pain, swelling, and sinus tract. Apical surgery was performed. Histopathological assessment of the apical root fragment collected showed the presence of dentin, cementum and pulp tissue, including odontoblasts. The 5-year follow-up depicted complete apical healing. The present case reports support survival and continued potential differentiation of the apical papilla after endodontic infection. [ABSTRACT FROM AUTHOR]
- Published
- 2019
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38. In vivo biocompatibility of Resilon compared with gutta-percha in a pre-clinical model
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Cardoso, Miguel, Marques, Rodrigo F, Lopes, Maria Francelina, Cabrita, António S, and Santos, João Miguel
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lcsh:RK1-715 ,lcsh:Dentistry ,Endodontic materials ,Original Article ,rat ,Resilon ,subcutaneous implantation ,gutta-percha - Abstract
Background: The aim of this study was to investigate in vivo biocompatibility of Resilon, compared with gutta-percha, at short and long-term following implantation in a rat subcutaneous implantation model. Materials and Methods: Male Wistar rats were implanted subcutaneously with either Resilon or gutta-percha or were sham controls. Tissues were harvested at 8 days or 60 days after implantation and were evaluated histologically for inflammation and fibrous encapsulation. The severity of histologic injury, scored on a scale of 0-4 and quantitative analysis of the capsule wall thickness were determined for statistical analysis. Data were analyzed by Student t-test, one-way analysis of variance, Kruskal-Wallis or Mann-Whitney′s tests as appropriate. A value of P ≤ 0.05 was considered statistically significant. Results: No behavioral changes or visible signs of physical impairment were observed at 8 days or 60 days post-implantation. Histopathologic observation of the implanted sites at each time-point showed that both Resilon and gutta-percha implants induced foreign body reaction, showing minimal to mild inflammatory reactions in most cases, which diminished significantly with time. Compared with gutta-percha, the capsule wall was thinner (P > 0.05) after Resilon implantation at day 8 and significantly (P = 0.01) thicker at day 60. In addition, capsule wall thickness showed a trend to increase with time after implantation in the Resilon groups (P > 0.05), opposed to the significant decrease (P = 0.016) observed after implantation in the gutta-percha groups, suggesting lesser long-term biocompatibility of Resilon. Conclusion: Our findings validate Resilon as an in vivo biocompatible material. However, our data suggest that long-term biocompatibility of Resilon, despite validated, is inferior to that of gutta-percha control.
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- 2013
39. Improving minimum rate predictors algorithm for compression of volumetric medical images
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Santos, João Miguel Pereira da Silva, Faria, Sérgio Manuel Maciel de, and Rodrigues, Nuno Miguel Morais
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Compressão sem Perdas ,MRP ,ComputingMethodologies_IMAGEPROCESSINGANDCOMPUTERVISION ,Engenharia e Tecnologia::Engenharia Eletrotécnica, Eletrónica e Informática [Domínio/Área Científica] ,Data_CODINGANDINFORMATIONTHEORY ,Imagens Médicas ,DICOM - Abstract
Medical imaging technologies are experiencing a growth in terms of usage and image resolution, namely in diagnostics systems that require a large set of images, like CT or MRI. Furthermore, legal restrictions impose that these scans must be archived for several years. These facts led to the increase of storage costs in medical image databases and institutions. Thus, a demand for more efficient compression tools, used for archiving and communication, is arising. Currently, the DICOM standard, that makes recommendations for medical communications and imaging compression, recommends lossless encoders such as JPEG, RLE, JPEG-LS and JPEG2000. However, none of these encoders include inter-slice prediction in their algorithms. This dissertation presents the research work on medical image compression, using the MRP encoder. MRP is one of the most efficient lossless image compression algorithm. Several processing techniques are proposed to adapt the input medical images to the encoder characteristics. Two of these techniques, namely changing the alignment of slices for compression and a pixel-wise difference predictor, increased the compression efficiency of MRP, by up to 27.9%. Inter-slice prediction support was also added to MRP, using uni and bi-directional techniques. Also, the pixel-wise difference predictor was added to the algorithm. Overall, the compression efficiency of MRP was improved by 46.1%. Thus, these techniques allow for compression ratio savings of 57.1%, compared to DICOM encoders, and 33.2%, compared to HEVC RExt Random Access. This makes MRP the most efficient of the encoders under study.
- Published
- 2016
40. A Comprehensive Life Cycle Approach for Managing Pavement Systems
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Santos, João Miguel Oliveira dos, Ferreira, Adelino, and Flintsch, Gerardo
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Life Cycle Pavement Optimization ,Genetic Algorithms ,Pavement Construction and Maintenance ,Life Cycle Costs Analysis ,Life Cycle Assessment - Abstract
Tese de doutoramento em Sistemas de Transporte, apresentada ao Departamento de Engenharia Civil da Faculdade de Ciências e Tecnologia da Universidade de Coimbra Numa sociedade em que consciência pública sobre a protecção do ambiente é cada vez mais notória, e a disponibilidade de recursos naturais e de financiamento é limitada, as concessionárias rodoviárias e os decisores procuram, hoje, mais do que nunca, ferramentas que lhes possibilitem utilizar esses recursos de forma mais racional, tendo em conta factores ambientais e sociais juntamente com considerações económicas e técnicas. No entanto, as práticas tradicionalmente adoptadas pelas concessionárias rodoviárias no que diz respeito à gestão de pavimentos tem consistido essencialmente na aplicação de sistemas de Avaliação dos Custos do Ciclo de Vida (ACCV) com o objectivo de avaliar o valor económico de longo prazo de opções alternativas de investimento para novos projectos de construção, manutenção e reabilitação (M&R). Esta forma de apoio à tomada de decisão, em que nenhuma ou reduzida importância é dada às considerações ambientais, não é eficaz na promoção da sustentabilidade dos sistemas de pavimentos rodoviários. Nessa perspectiva, é evidente a necessidade urgente de Sistemas de Apoio à Decisão (SAD) para a gestão de pavimentos, que através da integração de abordagens complementares e multidisciplinares de ciclo de vida de pavimentos, permitam aos decisores contabilizar os efeitos cumulativos e de longo prazo das suas decisões e procedimentos, no que diz respeito à concretização dos objectivos e metas de sustentabilidade. Tal só será possível através da utilização de técnicas e ferramentas dotadas de uma capacidade de análise abrangente e com um âmbito alargado. Esta tese apresenta um SAD para optimizar a gestão de pavimentos ao nível de projecto que inclui várias abordagens de ciclo de vida de pavimentos, com uma natureza abrangente e autónoma, mas interligadas de forma lógica. Especificamente, os seguintes métodos de avaliação são apresentados: um modelo de Avaliação do Ciclo de Vida (ACV), um modelo de CCV, um modelo integrado de CCV-ACV, um modelo de optimização mono-objectivo do ciclo de vida e um modelo de optimização multiobjectivo do ciclo de vida. Inicialmente são desenvolvidos modelos individuais de ACV e CCV de pavimentos, que visam quantificar os impactes ambientais e os custos suportados pelas concessionárias rodoviárias e pelos utilizadores ao longo das seis fases do ciclo de vida de um pavimento rodoviário: extracção e produção de materiais; construção e M&R; transporte de materiais; gestão do tráfego nas zonas de trabalhos; utilização; e fim do ciclo de vida. Posteriormente, um modelo abrangente e integrado de CCV-ACV de pavimentos é desenvolvido, a fim de se melhorar a consistência das fronteiras do sistema do ciclo de vida de um pavimento, quando analisado concomitantemente dos pontos de vista ambiental e económico. Tendo em vista a melhoria progressiva da capacidade de análise do SAD, um modelo de optimização mono-objectivo do ciclo de vida é desenvolvido para lidar com o problema da selecção de estratégias de M&R dos pavimentos. A abordagem proposta assenta num modelo de optimização discreta e não-linear que é resolvido através de um algoritmo genético híbrido adaptativo (AGHA). O algoritmo desenvolvido possui dois mecanismos de aprendizagem dinâmica que tem como objectivos conduzir e combinar, de forma dinâmica, os processos de refinamento e exploração das soluções do problema. O novo AGHA é comparado com uma versão não híbrida do algoritmo genético através da aplicação dos algoritmos a vários casos de estudo. Por último, para melhorar a expectativa de realização simultânea dos objectivos ambientais e de custos, uma metodologia de optimização multi-objectivo do ciclo de vida é proposta. A metodologia possui três componentes: (1) um modelo de optimização multi-objectivo; (2) um modelo abrangente e integrado de CCV-ACV de pavimentos; e (3) um modelo de apoio à decisão. A metodologia de optimização multi-objectivo proposta é aplicada na identificação da estratégia óptima de M&R de um pavimento rodoviário flexível, que resulte no melhor compromisso entre os três objectivos seguintes: (1) minimização do valor actual dos CCV suportados pelas concessionárias rodoviárias; (2) minimização do valor actual dos CCV suportados pelos utilizadores; e (3) minimização dos impactes ambientais do ciclo de vida. Todas as abordagens de ciclo de vida de pavimentos são aplicadas a casos de estudo reais ou a casos de estudos académicos baseados nas práticas reais adoptadas pelas concessionárias rodoviárias, que visam não só o cumprimentos dos requisitos técnicos, mas também a melhoria da sustentabilidade dos pavimentos através da redução dos impactes ambientais e dos CCV suportados pelas concessionárias rodoviárias e pelos utilizadores. Os resultados mostram a utilidade das metodologias de ciclo de vida que integram o SAD como ferramentas viáveis para ajudar as concessionárias rodoviárias e os decisores a concretizar os objectivos e as metas económicas e ambientais cumulativas e de longo prazo. In a society where the public awareness of environmental protection is increasing remarkably and the availability of resources and funding is limited, it is more vital than ever that highway agencies and decision-makers (DMs) seek new tools that enable them to make the best and most rational use of these resources, taking into account environmental and social factors, along with economic and technical considerations. However, the traditional practices adopted by highway agencies with regards to pavement management, have mostly consisted of employing life cycle costs analysis (LCCA) systems to evaluate the overall long-term economic efficiency of competing pavement design and maintenance and rehabilitation (M&R) activity alternatives. This way of supporting the decision-making process, as it relates to pavement management, in which little or no importance is given to environmental considerations, does not seem to be effective in advancing sustainability in pavement systems. In view of this, it is clear there is an urgent need for pavement management decision-support systems (DSSs), which, by integrating multi-disciplinary and complementary pavement life cycle approaches, will enable the DMs to properly account for, consider and assess the cumulative and long-term impacts of their decisions and practices regarding sustainability goals and targets. This can only be achieved by employing techniques and tools with a comprehensive and wide-scoped cradle-to-grave analysis capacity. This thesis presents a project-level optimization-based pavement management DSS, which includes several comprehensive stand-alone but logically interconnected pavement life cycle approaches. The following appraisal methods are presented: a life cycle assessment (LCA) model, a life cycle costs (LCC) model, an integrated LCCLCA model, a single-objective life cycle optimization model and a multi-objective life cycle optimization model. Initially, individual pavement LCA and LCC models are developed to quantify the environmental impacts and the costs incurred by highway agencies and road users throughout six pavement lifecycle phases: materials extraction and production, construction and M&R; transportation of materials; work zone (WZ) traffic management; usage; and end-of-life (EOL). Subsequently, a comprehensive and integrated pavement LCC-LCA model is developed, in order to improve the consistency between the system boundaries of the pavement life cycle when analyzed concomitantly from the economic and environmental viewpoints. In view of the progressive enhancement of the capability of analysis of the DSS, a single-objective life cycle optimization model is developed to tackle the pavement M&R strategy selection problem. The proposed approach relies on a non-linear discrete optimization model that is solved through an Adaptive Hybrid Genetic Algorithm (AHGA). The developed algorithm contains two dynamic learning mechanisms to adaptively guide and combine the exploration and exploitation search processes. The new AHGA is compared to a non-hybridized version of the GA by applying the algorithms to several case studies with the objective of determining the best pavement M&R strategy that minimizes the PV of the total M&R costs. Finally, to enhance the prospect of simultaneous accomplishment of both cost and environmental objectives, a multi-objective life cycle optimization methodology is proposed. The methodology contains three main components: (1) a multi-objective optimization (MOO) model; (2) a comprehensive and integrated pavement LCC-LCA model; and (3) a decision-support module. The proposed multi-objective optimization methodology is applied to determine the optimal M&R strategies for a flexible pavement section of a highway which yields the best tradeoff between the following three, often conflicting, objectives: (1) minimization of the PV of the total life cycle highway agency costs (LCHAC); (2) minimization of the PV of the life cycle road user costs (LCRUC); and (3) minimization of the life cycle environmental impacts (LCEI). All the pavement life cycle approaches are applied to either real or academic case studies based on highway agencies’ real practices, which, in addition to meeting the technical requirements, strive to enhance pavement sustainability by providing potential LCHAC and LCRUC savings and reduced environmental impacts. The results show the usefulness of the pavement life cycle-based methodologies integrating the DSS as viable tools to help highway agencies and DMs in making decisions that are more sustainable for meeting the cumulative and long-term economic and environmental goals and targets. FCT - SFRH/BD/79982/2011
- Published
- 2016
41. Histomorfometric analysis of the revascularization procedure – experimental study
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Palma, Paulo, Ramos, João Carlos, Patricio, Miguel, Ferreira, Paula, Viegas, Carlos, and Santos, João Miguel
- Published
- 2015
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42. The Rathbone Hotel
- Author
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Santos, João Miguel Pereira dos, Afonso, Carlos Miguel Guimarães Pinto Coelho, and Rodrigues, Henrique
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The Rathbone Hotel ,Direcção e Gestão Hoteleira ,Universidade do Algarve ,Estratégia de Social Media ,Estágio ,Ciências Sociais::Economia e Gestão [Domínio/Área Científica] - Abstract
Dissertação de Mestrado, Direção e Gestão Hoteleira, Escola Superior de Gestão, Hotelaria e Turismo, Universidade do Algarve, 2016 Para concluir o curso de Mestrado em Direção e Gestão Hoteleira da Universidade do Algarve, foi solicitado aos estudantes que realizassem tese, projeto final ou estágio e respetivo relatório. Sendo o estágio a minha preferência, concorri para diversos hotéis no estrangeiro e fui selecionado para o The Rathbone Hotel em Londres. O objectivo primordial do estágio é ganhar experiência prática na indústria hoteleira e aplicar em simultâneo competências ganhas durante o curso, estando em contato direto com uma cultura diferente. No primeiro dia, foi elaborado um plano de estágio com informação referente aos departamentos e funções a desempenhar, a duração de permanência em cada um deles e o supervisor atribuído para formação. As primeiras funções atribuídas foram de night porter, seguido dos departamentos de limpeza, comidas e bebidas, contabilidade, reservas, receção, terminando em cargo de direção. Durante o período de estágio tive a oportunidade de conhecer pessoas de negócios para futuros contatos profissionais, desempenhei diversas funções em vários departamentos do hotel, elaborei relatórios solicitados pela direção, estive presente em importantes reuniões usando os meus conhecimentos e competências técnicas e fui sempre flexível para ajudar onde era necessário. Desta forma o estágio permitiu-me adquirir elementos chave de aprendizagem, essenciais para o meu futuro profissional na área hoteleira. Em suma, todas as tarefas atribuídas foram desempenhadas com sucesso, nos períodos propostos e de acordo com os standards do hotel. O relatório de estágio tem início com uma breve descrição da empresa e da marca, uma análise interna e externa, focando ainda os aspectos gerais diferenciadores do hotel e dos seus competidores. Através da revisão de literatura foram explorados todos os departamentos e tarefas do hotel e realçados os problemas encontrados e as soluções propostas. Enquanto a minha permanência no departamento de vendas, foi traçada uma nova estratégia de social media que virei a desenvolver como consultor apos final do estágio.
- Published
- 2015
43. Is the chlorophyll derivative Zn(II)e6Me a good photosensitizer to be used in root canal disinfection?
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Diogo, Patrícia, Mota, Marta, Fernandes, Chantal, Sequeira, Diana, Palma, Paulo, Caramelo, Francisco, Neves, M. Graça P.M.S., Faustino, M. Amparo F., Gonçalves, Teresa, and Santos, João Miguel
- Abstract
Background The aim of this study was to assess antimicrobial efficacy and cytotoxic outcomes of a chlorophyll based photosensitizer (PS) Zn(II)chlorin e 6 methyl ester (Zn(II)e 6 Me), when applied to human dentin discs and root blocks infected with 48 h biofilms. The results were compared with the ones obtained with FotoSan® (commercial Toluidine Blue O formulation) and 3% sodium hypochlorite (NaOCl). Methodology Dentin and root blocks were infected with mixed biofilms of Enterococcus faecalis and Candida albicans ; exposed for 15 min to 0.1 mg/mL of Zn(II)e 6 Me or Fotosan ® and then irradiated with red light (627 nm, 75 mW, 3150 J/cm 2 ) for 90 s or treated with NaOCl. Biofilm removal was calculated with safranin red assay and biofilm cells viability with XTT® assay. The PSs cytotoxicity was evaluated over human apical papilla primary cell line (hAPCs) with AlamarBlue® assay and cell morphology assessed with widefield fluorescence microscopy. Results At dentin discs, the chlorophyll derivative performed better in biofilm removal (59.1%) than FotoSan® agent (57.5%), however, with lower efficacy than NaOCl (68.1%) ( P = 0.0185). Conversely, at the root block, the chlorophyll Zn(II)e 6 Me (79.7%) present better antimicrobial efficacy than NaOCl (75.5%) and the disinfection pattern was more consistent at inner and outer samples for the former. No dark or photoinduced cytotoxic outcomes were detected for Zn(II)e 6 Me over human cells at 24 and 48 h when compared with other PSs (FotoSan ® , Rose Bengal and 5,10,15,20-tetrakis(1-methylpyridinium-4-yl)porphyrin - TMPyP). Conclusions The chlorophyll derivative Zn(II)e 6 Me showed adequate antimicrobial efficacy, performing better in mixed biofilm removal than FotoSan ® in both experimental conditions. No cytotoxic effects over human apical papilla cells were identified for this chlorophyll derivative, subsequently it deserves further evaluation to assess its potential use in endodontic therapy. [ABSTRACT FROM AUTHOR]
- Published
- 2018
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44. Interactive Clinical Pedigree Visualization Using an Open Source Pedigree Drawing Engine.
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Santos, João Miguel, Santos, Beatriz Sousa, and Teixeira, Leonor
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- 2015
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45. Using Ontologies and Semantic Web Technology on a Clinical Pedigree Information System.
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Santos, João Miguel, Sousa Santos, Beatriz, and Teixeira, Leonor
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- 2014
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46. Subcutaneous Implantation Assessment of New Calcium-Silicate Based Sealer for Warm Obturation.
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Santos, João Miguel, Coelho, Carolina M., Sequeira, Diana B., Marques, Joana A., Pereira, Joana F., Sousa, Vitor, Palma, Paulo J., and Santos, Ana C.
- Subjects
MANN Whitney U Test ,LABORATORY rats ,KRUSKAL-Wallis Test ,CONNECTIVE tissues - Abstract
Calcium silicate-based sealers were recently introduced as a new class of endodontic sealers, with potential further benefits due to their bioactivity. The aim of this study was to evaluate the biocompatibility of two new hydraulic calcium silicate-based sealers, TotalFill BC Sealer (FKG, La Chaux-des-Fonds, Switzerland) and TotalFill BC Sealer HiFlow (FKG, La Chaux-des-Fonds, Switzerland) through subcutaneous implantation in connective tissue of rats. Subcutaneous implantation was performed in 16 young Wistar rats. Four polyethylene tubes were implanted in each animal, one empty to serve as a control, and three filled with tested sealers: AH Plus as reference (Dentsply DeTrey, Konstanz, Germany), TotalFill BC Sealer (BC) and TotalFill BC Sealer HiFlow (HiFlow). Eight rats were euthanized at 8 days and the remaining eight at 30 days. Hematoxylin-eosin staining was used to score the inflammatory reaction, macrophage infiltrate and to measure the thickness of the fibrous capsule. von Kossa staining was performed to evaluate the mineralization level. Kruskal–Wallis test followed by Dunn's post hoc test was used to analyze non-parametric data. To analyze the influence of the implantation time within each material, a Mann–Whitney U test was performed. At eight days post-implantation, AH Plus induced a more intense inflammatory reaction when compared both with the control (p ≤ 0.001) and BC (p ≤ 0.01). HiFlow presented a higher score of macrophage infiltrate than control (p ≤ 0.01) and BC (p ≤ 0.05). The fibrous capsule thickness in this period was significantly higher for the BC group when compared to control (p ≤ 0.01) and AH Plus (p ≤ 0.05). The mineralization potential was higher for the HiFlow group when compared with the control (p ≤ 0.001) and AH Plus (p ≤ 0.001). At 30 days post-implantation, the score for the inflammatory reaction remained higher for the AH Plus group when compared both to control (p ≤ 0.01) and BC (p ≤ 0.001). The macrophage infiltrate of the HiFlow was significantly higher than control (p ≤ 0.001) and AH Plus groups (p ≤ 0.01), additionally, the fibrous capsule of the BC (p ≤ 0.001) and HiFlow (p ≤ 0.01) groups were both thicker than control. Mineralization potential was observed only on BC (p ≤ 0.05) and HiFlow groups (p ≤ 0.001), when compared to control). BC exhibited the best biocompatibility performance of all tested sealers and HiFlow provided the greatest induction of mineralized tissues. Both TotalFill BC Sealer and TotalFill BC Sealer HiFlow are biocompatible and show potential bioactivity when implanted in the subcutaneous tissue. Bioactivity was not found in AH Plus. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
47. Evaluation of Root-End Preparation with Two Different Endodontic Microsurgery Ultrasonic Tips.
- Author
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Palma, Paulo J., Marques, Joana A., Casau, Margarida, Santos, André, Caramelo, Francisco, Falacho, Rui I., and Santos, João Miguel
- Subjects
MICROSURGERY ,SCANNING electron microscopy - Abstract
The aim of this study is to compare root-end preparation performed with two different ultrasonic tips—CVDentus and NSK—and respective time requirements. After root-end resection, 32 teeth were randomly divided in two groups, according to the ultrasonic tip used for root-end preparation. Preparation time was recorded. Photomicrographs were taken to assess the following parameters: root surface microcracking, marginal integrity and presence of debris. One ultrasonic tip from each group was analyzed through scanning electron microscopy before and after root-end preparation. The significance level was set at α = 0.05. Incidence of microcracks in both groups was 12.5%. Solely intracanal microcracking was found, consistently positioned within the widest side of the remaining dentine. No statistically significant differences were verified between both experimental groups regarding marginal integrity (p = 0.102) and preparation time (p = 0.780), whereas statistical differences (p = 0.003) were found concerning the presence of debris (the minimum registered score was mostly verified in CVDentus group). NSK tips showed major morphological changes, with extensive surface wear and noticeable loss of particles, which was not verified on CVDentus tips. Our findings suggest significant differences regarding root-end preparation walls quality, with CVDentus tips showing better results. Concerning microcracking, as well as preparation time and marginal integrity, both ultrasonic tips showed similar results. Qualitative analysis exposed NSK tips major morphological changes and wear after use, which was not verified on CVDentus tips. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
48. An Insight into Advanced Approaches for Photosensitizer Optimization in Endodontics—A Critical Review.
- Author
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Diogo, Patrícia, F. Faustino, M. Amparo, P. M. S. Neves, M. Graça, Palma, Paulo J., P. Baptista, Isabel, Gonçalves, Teresa, and Santos, João Miguel
- Subjects
PHOTOSENSITIZERS ,DRUG delivery systems ,PHOTODYNAMIC therapy ,DENTAL discoloration ,ENDODONTICS - Abstract
Apical periodontitis is a biofilm-mediated disease; therefore, an antimicrobial approach is essential to cure or prevent its development. In the quest for efficient strategies to achieve this objective, antimicrobial photodynamic therapy (aPDT) has emerged as an alternative to classical endodontic irrigation solutions and antibiotics. The aim of the present critical review is to summarize the available evidence on photosensitizers (PSs) which has been confirmed in numerous studies from diverse areas combined with several antimicrobial strategies, as well as emerging options in order to optimize their properties and effects that might be translational and useful in the near future in basic endodontic research. Published data notably support the need for continuing the search for an ideal endodontic photosensitizer, that is, one which acts as an excellent antimicrobial agent without causing toxicity to the human host cells or presenting the risk of tooth discoloration. The current literature on experimental studies mainly relies on assessment of mixed disinfection protocols, combining approaches which are already available with aPDT as an adjunct therapy. In this review, several approaches concerning aPDT efficiency are appraised, such as the use of bacteriophages, biopolymers, drug and light delivery systems, efflux pump inhibitors, negative pressure systems, and peptides. The authors also analyzed their combination with other approaches for aPDT improvement, such as sonodynamic therapy. All of the aforementioned techniques have already been tested, and we highlight the biological challenges of each formulation, predicting that the collected information may encourage the development of other effective photoactive materials, in addition to being useful in endodontic basic research. Moreover, special attention is dedicated to studies on detailed conditions, aPDT features with a focus on PS enhancer strategies, and the respective final antimicrobial outcomes. From all the mentioned approaches, the two which are most widely discussed and which show the most promising outcomes for endodontic purposes are drug delivery systems (with strong development in nanoparticles) and PS solubilizers. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
49. Six-Month Color Stability Assessment of Two Calcium Silicate-Based Cements Used in Regenerative Endodontic Procedures.
- Author
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Palma, Paulo J., Marques, Joana A., Falacho, Rui I., Correia, Eder, Vinagre, Alexandra, Santos, João Miguel, and Ramos, João C.
- Subjects
COLORIMETRY ,TOOTH cervix ,BLOOD groups ,MINERAL aggregates ,STATISTICAL significance ,CALCIUM silicates ,GUTTA-percha - Abstract
Aim: The purpose of the present study is to assess the color stability of two calcium silicate-based cements (CSCs) used in regenerative endodontic procedures (REPs). Methods: A total of 40 acrylic single-rooted transparent teeth, with immature apex, were used. Root canals were filled up to 3 mm below the level of the cementoenamel junction, with either saline solution (Mineral Trioxide Aggregate (MTA)/saline and Biodentine/saline) or blood (MTA/blood and Biodentine/blood). Subsequently, ProRoot MTA
® or BiodentineTM was placed in the root canal to create a cervical barrier. Color measurement was carried out at four different evaluation periods (3 h, 72 h, 7 days, and 6 months). Shade analysis within the L* a* b* color space was performed and color variation (∆E) calculated. The significance level for statistical analysis was set at p < 0.05. Results: The four groups showed a significant decrease in L* values over time. The ΔE value increased over time for all groups but was not statistically significant for the Biodentine/blood group. Two-way ANOVA showed no interaction between the CSC and treatment (contact with saline solution or blood). CSC used was the factor responsible for ΔE over time, inducing statistically significant color variations from T3H to T7D (p = 0.04) and T3H to T6M (p < 0.01). After 6 months, MTA/saline had 5.08 (p = 0.001) higher ΔE than Biodentine/Saline and the MTA/blood had 3.65 (p = 0.009) higher than Biodentine/blood. Conclusions: After 6 months, regardless of blood exposure, Biodentine exhibits superior color stability compared to MTA. Biodentine might be a suitable alternative to MTA as a cervical barrier material in REPs. [ABSTRACT FROM AUTHOR]- Published
- 2019
- Full Text
- View/download PDF
50. Does Delayed Restoration Improve Shear Bond Strength of Different Restorative Protocols to Calcium Silicate-Based Cements?
- Author
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Palma, Paulo J., Marques, Joana A., Falacho, Rui I., Vinagre, Alexandra, Santos, João Miguel, and Ramos, João Carlos
- Subjects
SHEAR strength ,BOND strengths ,CALCIUM silicates ,DENTAL cements ,COMPOSITE materials - Abstract
The purpose of the present study was to assess the proper time to perform a restoration (immediately or delayed) after placement of two calcium silicate-based cements (CSCs) and to test the performance of two different restorative protocols regarding shear bond strength (SBS). Seventy-five acrylic blocks were randomly divided into five groups (n = 15). Specimens were filled with either ProRoot MTA (Dentsply Tulsa Dental) or Biodentine (Septodont). The restoration was performed at an immediate (12 min) or delayed (seven days) timeframe, using a resin-based flowable composite (SDR) (bonded to the CSC using a universal bonding system) or glass ionomer cement (GIC) as restorative materials. SBS was measured using a universal testing machine. Fractured surfaces were evaluated, and the pattern was registered. Statistical analysis was performed using the Dunn–Sidak post hoc test (P < 0.05). Biodentine/immediate SDR showed the highest mean SBS value (4.44 MPa), with statistically significant differences when compared to mineral trioxide aggregate (MTA)/GIC (1.14 MPa) and MTA/immediate SDR (1.33 MPa). MTA/GIC and MTA/immediate SDR did not present significant differences regarding SBS. No statistical differences were verified concerning mean SBS between both CSCs within the 7 day groups. MTA/delayed SDR (3.86 MPa) presented statistical differences compared to MTA/immediate SDR, whereas no differences were observed regarding Biodentine performance (Biodentine/immediate SDR and Biodentine/delayed SDR (3.09 MPa)). Bonding procedures directly on top of MTA might be preferably performed at a delayed timeframe, whereas Biodentine might allow for immediate restoration. [ABSTRACT FROM AUTHOR]
- Published
- 2018
- Full Text
- View/download PDF
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