3,327 research outputs found

    Malignant tumors of the temporal bone - our experience

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    INTRODUCTION: Malignant tumors of the temporal bone are rare, with an estimated incidence of about 0.8-1.0 per 1,000,000 inhabitants per year. The vast majority of these tumors are squamous cell carcinomas and their treatment is eminently surgical. OBJECTIVE: This study is an attempt at systematizing the forms of clinical presentation, the therapeutic possibilities, and oncological outcomes of patients with malignant tumors of the temporal bone in a tertiary hospital in Portugal. METHODS: The authors present a retrospective study of temporal bone tumors treated and followed during otorhinolaryngology consultations between 2004 and 2014. A review of the literature is also included. RESULTS: Of the 18 patients included in the study, 16 had a primary tumor of the temporal bone, in most cases with squamous cell carcinoma histology. Of these, 13 patients were treated with curative intent that always included the surgical approach. Disease persistence was observed in one patient and local recurrence in five patients, on average 36.8 months after the initial treatment. CONCLUSIONS: The anatomical complexity of the temporal bone and the close associations with vital structures make it difficult to perform tumor resection with margins of safety and thus, tumor relapses are almost always local. A high level of suspicion is crucial for early diagnosis, and stringent and prolonged follow-up after treatment is essential for diagnosis and timely treatment of recurrances.info:eu-repo/semantics/publishedVersio

    Three essays in financial markets

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    A PhD Dissertation, presented as part of the requirements for the Degree of Doctor of Philosophy from the NOVA - School of Business and Economic

    Positron emission tomography in the detection of occult primary head and neck carcinoma: a retrospective study

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    BACKGROUND: The management of cervical lymph node metastases from an unknown primary tumor remains a controversial subject. Recently, Positron Emission Tomography (PET) has proved useful in the detection of these tumors, even after an unsuccessful conventional diagnostic workup. This study was performed to assess the role of PET in the detection of occult primary head and neck carcinomas. METHODS: A retrospective analysis of a four year period at a tertiary referral oncology hospital was conducted. RESULTS: Of the 49 patients with cervical metastases of carcinoma from an unknown primary, PET detected a primary in 9 patients and gave 5 false positive and 4 false negative results. Detection rate, sensitivity, specificity and accuracy were of 18.4%, 69.2%, 86.1% and 81.6%, respectively. PET was also of substantial benefit in detecting distant metastatic disease and, thus, altered therapeutic strategies in a significant amount of patients. CONCLUSIONS: Therefore, PET is a valuable tool in the management of patients with occult primary head and neck carcinoma, not only because it provides additional information as to the location of primary tumors, but also due to the fact that it can detect unexpected distant metastase

    Monitoring multicast traffic in heterogeneous networks

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    Estágio realizado no INESC - Porto e orientado pelo Prof. Doutor Ricardo MorlaTese de mestrado integrado. Engenharia Electrotécnica e de Computadores - Major Telecomunicações. Faculdade de Engenharia. Universidade do Porto. 200

    Deep learning techniques applied to skin lesion classification: a review

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    Skin cancer is one of the most common cancers in the world. The most dangerous type of skin cancer is melanoma, which can be lethal if not treated early. However, diagnosing skin lesions can be a difficult task. Therefore, deep learning techniques applied to the diagnosis of skin lesions have been explored by researchers, given their effectiveness in extracting features and classifying input data. In this work, we present a review of latest approaches that apply deep learning techniques to skin lesion classification task. In addition, some datasets used for training and validating the models are introduced, informing their characteristics and specificities, as well as popular pre-processing steps and skin lesion segmentation approaches. Finally, we comment the effectiveness of the proposed models.info:eu-repo/semantics/publishedVersio

    On the physical refining of edible oils for obtaining high quality products

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    Vegetable oils are important compounds of the human diet and they should be refined before consumption. Consumers demand for healthier products as well as stiff environmental legislation are forcing refining industries towards changes and improvement of processes. In this context, this thesis has as main objective to investigate/improve the physical refining of vegetable oils, emphasizing the bleaching step. As first step, a HPLC methodology for simultaneous quantification of carotenes and tocols was developed and validated, and lately, it was used by our research groups. Then, bleaching step of palm oil, nowadays the most consumed oil in the world, was studied under different aspects: (1) determining kinetics, equilibrium and thermodynamic parameters of adsorptive removal of carotenes and phosphorus onto acid activated bleaching earth; (2) influence of different procedures on final color of palm oil; (3) influence of bleaching earth kind on final color of palm oil. These studies were important for a better understanding of bleaching process of palm oil, and some conclusions were obtained: adsorptive removal of carotenes and phosphorus onto acid activated bleaching earth occurs by chemisorption and it is endothermic; new procedures in the bleaching step can improve final color of palm oil when using the same amount of bleaching earth and deodorization time; a hypothesis was proposed to explain how the kind of bleaching earth can interfere in the final color of palm oil. Further studies are still necessary to optimize bleaching step and the new procedures suggested. Later, physical deacidification was studied by computer simulation and experimental data from literature. It was compared two mathematical approaches: differential and flash distillations. This last one presented better results regarding acidity and neutral oil loss profiles. In this approach, it was considered the heat transfer equations. In this way, this thesis presents an advance in refining process towards high quality products and the use of less chemicals

    Permeability of matrices of agricultural crops to Euglossina bees (Hymenoptera, Apidae) in the Atlantic Rain Forest

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    International audienceAbstractWe evaluate the permeability of three matrices of arboreal crops for the Euglossina bees that inhabit the Brazilian Atlantic rainforest hotspot. The comparisons of occurrences and abundances within three mosaics of forest and extensive arboreal crops (piassava palm, oil palm, and rubber tree) showed that all the matrices were permeable to most orchid bees. The piassava palm was the most permeable, where the spatial distribution of all species of Euglossina did not differ between forest fragments and matrix. The oil palm has shown some loss of permeability to Eulaema atleticana, while the rubber tree crop was not so permeable to El. atleticana and Euglossa imperialis. Euglossa iopoecila was sampled only in the forest fragments. At the present scale of forest cover in the three studied mosaics (10 to 40 %), the arboreal matrices are contributing towards the functional connectivity in the Atlantic Rain Forest at both scales: the landscape mosaic and the Brazilian Atlantic Forest corridor

    An overview about oxidation in clinical practice of skin aging

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    Free radicals are unstable chemical species, highly reactive, being formed by cellular entities of different tissues. Increased production of these species without proper effective action of endogenous and exogenous antioxidant systems, generates a condition of oxidative stress, potentially provider of skin disorders that extend from functional impairments (skin cancer, dermatitis, chronic and acute inflammatory processes) even aesthetic character, with the destruction of structural proteins and cellular changes with the appearance of stains, marks and lines of expressions and other signs inherent to the intrinsic and extrinsic skin aging process. The antioxidants are chemical substances commonly used in clinical practice for topical application and may contribute in the fight against the radical species responsible for many skin damage. This paper summarized the main evidence of the benefits brought by the topical application of antioxidants in the skin, considering the amplitude of the indicative performance of antioxidant activity by in vitro and ex-vivo tests as well as in vivo tests. It is recognized that a breadth of product performance tests should be explored to truly identify the effectiveness of antioxidant products for an anti-aging effect.Sao Paulo State Research Support FoundationNational Council for Scientific and Technological Development (CNPq)Univ Campinas UNICAMP, Fed Univ Sao Paulo UNIFESP, Postgrad Program Translat Med, Campinas, SP, BrazilUniv RUTGERS, New Brunswick, NJ USAUniv Fed Sao Paulo UNIFESP, Dept Med, Sao Paulo, SP, BrazilRutgers State Univ, Dept Pharmaceut, Ernest Mario Sch Pharm, New Brunswick, NJ USAUniv Estadual Campinas UNICAMP, Fac Pharmaceut Sci, Campinas, SP, BrazilUniv Fed Sao Paulo UNIFESP, Dept Med, Sao Paulo, SP, BrazilFAPESP: 2013-01118-5Web of Scienc
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