131 research outputs found

    Congenital cystic lesions of the biliary tree

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    OBJECTIVE: The purpose of this essay is to illustrate the imaging findings of congenital cystic lesions of the biliary tract. CONCLUSION: Congenital cystic lesions of the biliary tract include ductal plate malformations and choledochal cysts and can be recognized with characteristic imaging findings and basic knowledge of the embryologic development of the biliary tree

    Jacobi-Nijenhuis algebroids and their modular classes

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    Jacobi-Nijenhuis algebroids are defined as a natural generalization of Poisson-Nijenhuis algebroids, in the case where there exists a Nijenhuis operator on a Jacobi algebroid which is compatible with it. We study modular classes of Jacobi and Jacobi-Nijenhuis algebroids

    O conhecimento matemático dos estudantes no início da Licenciatura em Educação Básica: um projeto envolvendo três Escolas superiores de educação

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    O novo modelo de formação inicial (Decreto-Lei 43/2007) exige que os futuros professores do 1.º e 2.º ciclos do ensino básico e os futuros educadores de infância façam pelo menos 30 ECTS de formação em Matemática na Licenciatura em Educação Básica (LEB), mas a forma e o conteúdo desta formação é da responsabilidade de cada instituição, que define as unidades curriculares, o seu conteúdo e a forma como são lecionadas. Sabe-se que, para além do conteúdo, a forma como o professor aprende tem uma forte influência na forma como vai ensinar. Assim, todos estes aspetos precisam de ser discutidos, tendo por base a investigação já realizada em Portugal e noutros países. Partindo da assunção de que o conhecimento do professor constitui um fator decisivo na interpretação e implementação do currículo e da necessidade de uma discussão alargada de qual deverá ser o conteúdo da formação em Matemática na LEB, as Escolas Superiores de Educação de Lisboa, de Viana do Castelo e de Viseu iniciaram um projeto de investigação que tem como principal objetivo compreender de que modo a formação inicial contribui para o desenvolvimento do conhecimento do professor em Matemática e em Ensino da Matemática e como pode este ser promovido. Uma das questões que o projeto visa investigar é que conhecimento de conteúdo matemático têm os estudantes quando iniciam o curso da LEB. Para caracterizar o conhecimento matemático dos estudantes da LEB, à entrada no curso, foi elaborado um teste diagnóstico, que foi aplicado nas três Escolas Superiores de Educação, em outubro de 2011, a todos os alunos a iniciar o 1.º ano, num total de 268: 143 em Lisboa, 51 em Viseu e 74 em Viana do Castelo. Neste artigo é apresentada uma análise dos principais resultados deste teste bem como as questões e dilemas que aqueles resultados nos colocam

    One-shot diagnostic and prognostic assessment in intermediate- to high-risk acute pulmonary embolism: The role of multidetector computed tomography

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    INTRODUCTION: Contrast-enhanced multidetector computed tomography (MDCT) is useful for the diagnosis of pulmonary embolism (PE). However, current guidelines do not support its use for risk assessment in acute PE patients. OBJECTIVES: We compared the prognostic impact of MDCT-derived indices regarding medium-term mortality in a population of intermediate- to high-risk PE patients, mostly treated by thrombolysis. METHODS: Thirty-nine consecutive patients admitted to an intensive care unit with acute PE were studied. All patients had a pulmonary MDCT on admission to the emergency room as part of the diagnostic algorithm. We assessed the following MDCT variables: right ventricular/left ventricular diameter (RV/LV) ratio, arterial obstruction index, pulmonary artery-to-aorta diameter ratio and azygos vein diameter. A 33-month follow-up was performed. RESULTS: Mean age was 59.1±19.6 years, with 80% of patients receiving thrombolysis. Follow-up all-cause mortality was 12.8%. Of the MDCT-derived variables, only the RV/LV ratio had significant predictive value, being higher in patients who suffered the endpoint (1.6±0.5 vs. 1.9±0.4, p=0.046). Patients with an RV/LV ratio ≥1.8 had 11-fold higher medium-term all-cause mortality (3.8% vs. 38.8%, p<0.001). Regarding this endpoint, the c-statistic was 0.78 (95% CI, 0.60-0.96) for RV/LV ratio and calibration was good (goodness-of-fit p=0.594). No other radiological index was predictive of mortality. CONCLUSIONS: MDCT gives the possibility, in a single imaging procedure, of diagnosing and assessing the prognosis of patients with intermediate- to high-risk PE. Although further studies are needed, the simple-to-calculate RV/LV ratio has good discrimination and calibration for predicting poorer outcomes in patients with acute PE

    Recovering capitalization and punctuation marks for automatic speech recognition: case study for Portuguese broadcast news

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    The following material presents a study about recovering punctuation marks, and capitalization information from European Portuguese broadcast news speech transcriptions. Different approaches were tested for capitalization, both generative and discriminative, using: finite state transducers automatically built from language models; and maximum entropy models. Several resources were used, including lexica, written newspaper corpora and speech transcriptions. Finite state transducers produced the best results for written newspaper corpora, but the maximum entropy approach also proved to be a good choice, suitable for the capitalization of speech transcriptions, and allowing straightforward on-the-fly capitalization. Evaluation results are presented both for written newspaper corpora and for broadcast news speech transcriptions. The frequency of each punctuation mark in BN speech transcriptions was analyzed for three different languages: English, Spanish and Portuguese. The punctuation task was performed using a maximum entropy modeling approach, which combines different types of information both lexical and acoustic. The contribution of each feature was analyzed individually and separated results for each focus condition are given, making it possible to analyze the performance differences between planned and spontaneous speech. All results were evaluated on speech transcriptions of a Portuguese broadcast news corpus. The benefits of enriching speech recognition with punctuation and capitalization are shown in an example, illustrating the effects of described experiments into spoken texts.info:eu-repo/semantics/acceptedVersio

    Recovering capitalization and punctuation marks for automatic speech recognition: case study for Portuguese broadcast news

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    The following material presents a study about recovering punctuation marks, and capitalization information from European Portuguese broadcast news speech transcriptions. Different approaches were tested for capitalization, both generative and discriminative, using: finite state transducers automatically built from language models; and maximum entropy models. Several resources were used, including lexica, written newspaper corpora and speech transcriptions. Finite state transducers produced the best results for written newspaper corpora, but the maximum entropy approach also proved to be a good choice, suitable for the capitalization of speech transcriptions, and allowing straightforward on-the-fly capitalization. Evaluation results are presented both for written newspaper corpora and for broadcast news speech transcriptions. The frequency of each punctuation mark in BN speech transcriptions was analyzed for three different languages: English, Spanish and Portuguese. The punctuation task was performed using a maximum entropy modeling approach, which combines different types of information both lexical and acoustic. The contribution of each feature was analyzed individually and separated results for each focus condition are given, making it possible to analyze the performance differences between planned and spontaneous speech. All results were evaluated on speech transcriptions of a Portuguese broadcast news corpus. The benefits of enriching speech recognition with punctuation and capitalization are shown in an example, illustrating the effects of described experiments into spoken texts.info:eu-repo/semantics/acceptedVersio

    Mesenchymal Stem/ Stromal Cells metabolomic and bioactive factors profiles: A comparative analysis on the umbilical cord and dental pulp derived Stem/ Stromal Cells secretome

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    Mesenchymal Stem/ Stromal Cells assume a supporting role to the intrinsic mechanisms of tissue regeneration, a feature mostly assigned to the contents of their secretome. A comparative study on the metabolomic and bioactive molecules/factors content of the secretome of Mesenchymal Stem/ Stromal Cells derived from two expanding sources: the umbilical cord stroma and the dental pulp is presented and discussed. The metabolic profile (Nuclear Magnetic Resonance Spectroscopy) evidenced some differences in the metabolite dynamics through the conditioning period, particularly on the glucose metabolism. Despite, overall similar profiles are suggested. More prominent differences are highlighted for the bioactive factors (Multiplexing Laser Bear Analysis), in which Follistatin, Growth Regulates Protein, Hepatocyte Growth Factor, Interleukin-8 and Monocyte Chemotactic Protein-1 dominate in Umbilical Cord Mesenchymal Stem/ Stromal Cells secretion, while in Dental Pulp Stem/ Stromal Cells the Vascular Endothelial Growth Factor-A and Follistatin are more evident. The distinct secretory cocktail did not result in significantly different effects on endothelial cell populations dynamics including proliferation, migration, tube formation capacity and in vivo angiogenesis, or in chemotaxis for both Mesenchymal Stem/ Stromal Cells populations.This research was supported by Programa Operacional Regional do Norte (ON.2 - O Novo Norte), QREN, FEDER with the project "iBone Therapies: Terapias inovadoras para a regeneração óssea", ref. NORTE-01-0247-FEDER-003262, and by the program COMPETE - Programa Operacional Factores de Competitividade, Projects PEst-OE/AGR/UI0211/ 2011 and PEst-C/EME/UI0285/2013 funding from FCT. This research was also supported by Programa Operacional Competitividade e Internacionalização (P2020), Fundos Europeus Estruturais e de Investimento (FEEI) and FCT with the project "BioMate - A novel bio-manufacturing system to produce bioactive scaffolds for tissue engineering" with reference PTDC/EMS-SIS/7032/ 2014 and by COMPETE 2020, from ANI - Projetos ID&T Empresas em Copromoção, Programas Operacionais POCI, by the project "insitu.Biomas - Reinvent biomanufacturing systems by using an usability approach for in situ clinic temporary implants fabrication? with the reference POCI-01-0247-FEDER-017771. This work received further financial support from the framework of QREN through Project NORTE-07-0124-FEDER-000066. The Bruker Avance III 600 HD spectrometer was purchased under the framework of QREN, through Project NORTE-07-0162-FEDER-000048 and is part of the Portuguese NMR Network created with support of FCT through Contract REDE/1517/RMN/ 2005, with funds from POCI 2010 (FEDER). Ana Rita Caseiro (SFRH/BD/101174/2014) acknowledges FCT, for financial support. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript

    Dental pulp stem cells and Bonelike® for bone regeneration in ovine model

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    Development of synthetic bone substitutes has arisen as a major research interest in the need to find an alternative to autologous bone grafts. Using an ovine model, the present pre-clinical study presents a synthetic bone graft (Bonelike®) in combination with a cellular system as an alternative for the regeneration of non-critical defects. The association of biomaterials and cell-based therapies is a promising strategy for bone tissue engineering. Mesenchymal stem cells (MSCs) from human dental pulp have demonstrated both in vitro and in vivo to interact with diverse biomaterial systems and promote mineral deposition, aiming at the reconstruction of osseous defects. Moreover, these cells can be found and isolated from many species. Non-critical bone defects were treated with Bonelike® with or without MSCs obtained from the human dental pulp. Results showed that Bonelike® and MSCs treated defects showed improved bone regeneration compared with the defects treated with Bonelike® alone. Also, it was observed that the biomaterial matrix was reabsorbed and gradually replaced by new bone during the healing process. We therefore propose this combination as an efficient binomial strategy that promotes bone growth and vascularization in non-critical bone defects.This research was supported by Programa Operacional Regional do Norte (ON.2 – O Novo Norte), QREN, FEDER with the project ‘iBone Therapies: Terapias inovadoras para a regeneração óssea’, ref. NORTE-01-0247-FEDER-003262, and by the programme COMPETE – Programa Operacional Factores de Competitividade, Projects PEst-OE/AGR/UI0211/2011 and PEst-C/EME/UI0285/2013 funding from FCT. This research was also supported by Programa Operacional Competitividade e Internacionalizac¸~ao (P2020), Fundos Europeus Estruturais e de Investimento (FEEI) and FCT with the project ‘BioMate—A novel bio-manufacturing system to produce bioactive scaffolds for tissue engineering’ with reference PTDC/EMS-SIS/7032/2014 and by COMPETE 2020, from ANI—Projectos ID&T Empresas em Copromoção Programas Operacionais POCI, by the project ‘insitu.Biomas - Reinvent biomanufacturing systems by using an usability approach for in situ clinic temporary implants fabrication’ with the reference POCI-01-0247-FEDER-017771. The research was also supported by the research project ‘BEPIM III –Microdispositivos me´dicos com capacidades osteintegradoras por micoPIM’, with the reference POCI-01-0247-FEDER-017935, from Fundo Europeu de Desenvolvimento Regional (FEDER), by the Programa Operacional da Competitividade & Internacionalização. Ana Rita Caseiro (SFRH/BD/101174/2014) acknowledges FCT, for financial support
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