5,756 research outputs found

    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

    Coastal urbanization leads to remarkable seaweed species loss and community shifts along the SW Atlantic.

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    Coastal urbanization is rapidly expanding worldwide while its impacts on seaweed communities remain poorly understood. We assessed the impact of urbanization along an extensive latitudinal gradient encompassing three phycogeographical regions in the SW Atlantic. Human population density, number of dwellings, and terrestrial vegetation cover were determined for each survey area and correlated with diversity indices calculated from seaweed percent cover data. Urban areas had significantly lower calcareous algal cover (-38%), and there was significantly less carbonate in the sediment off urban areas than off reference areas. Seaweed richness averaged 26% less in urban areas than in areas with higher vegetation cover. We observed a remarkable decline in Phaeophyceae and a substantial increase of Chlorophyta in urban areas across a wide latitudinal gradient. Our data show that coastal urbanization is causing substantial loss of seaweed biodiversity in the SW Atlantic, and is considerably changing seaweed assemblages

    The use of oxalate to reduce dentin permeability under adhesive restorations

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    Abstract no. 1705published_or_final_versio

    Optimal Design of Robust Combinatorial Mechanisms for Substitutable Goods

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    In this paper we consider multidimensional mechanism design problem for selling discrete substitutable items to a group of buyers. Previous work on this problem mostly focus on stochastic description of valuations used by the seller. However, in certain applications, no prior information regarding buyers' preferences is known. To address this issue, we consider uncertain valuations and formulate the problem in a robust optimization framework: the objective is to minimize the maximum regret. For a special case of revenue-maximizing pricing problem we present a solution method based on mixed-integer linear programming formulation

    Bone Metabolism in Very Preterm Infants Receiving Total Parenteral Nutrition: do Intravenous Fat Emulsions Have an Impact?

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    ery preterm infants (<32 weeks' gestation) are at high risk for impaired skeletal development because of factors that limit the provision of extrauterine nutrients. Cumulative net deficiencies of calcium, phosphorus, docosahexaenoic acid (DHA), and arachidonic acid (ARA) are evident in these infants after prolonged administration of total parenteral nutrition (TPN). This is significant because minerals as well as metabolites of DHA and ARA are important modulators of bone cell differentiation, lengthening of bone, and bone matrix deposition. Furthermore, diets containing only precursors of DHA and ARA result in suboptimal skeletal growth. With the emergence of new intravenous lipid emulsions, it is important to understand the impact of fatty acids on bone metabolism in the third trimester in order to optimize the provision of TPN in very preterm infants. The purpose of this review is to evaluate current evidence regarding intravenous lipid emulsions and bone metabolism in very preterm infants receiving prolonged TPN and to identify areas of research needed.info:eu-repo/semantics/publishedVersio

    Accelerated age-related olfactory decline among type 1 Usher patients

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    Usher Syndrome (USH) is a rare disease with hearing loss, retinitis pigmentosa and, sometimes, vestibular dysfunction. A phenotype heterogeneity is reported. Recent evidence indicates that USH is likely to belong to an emerging class of sensory ciliopathies. Olfaction has recently been implicated in ciliopathies, but the scarce literature about olfaction in USH show conflicting results. We aim to evaluate olfactory impairment as a possible clinical manifestation of USH. Prospective clinical study that included 65 patients with USH and 65 normal age-gender-smoking-habits pair matched subjects. A cross culturally validated version of the Sniffin' Sticks olfaction test was used. Young patients with USH have significantly better olfactory scores than healthy controls. We observe that USH type 1 have a faster ageing olfactory decrease than what happens in healthy subjects, leading to significantly lower olfactory scores in older USH1 patients. Moreover, USH type 1 patients showed significantly higher olfactory scores than USH type 2, what can help distinguishing them. Olfaction represents an attractive tool for USH type classification and pre diagnostic screening due to the low cost and non-invasive nature of the testing. Olfactory dysfunction should be considered among the spectrum of clinical manifestations of Usher syndrome

    Anti-inflammatory activity of Blutaparon portulacoides ethanolic extract against the inflammatory reaction induced by Bothrops jararacussu venom and isolated myotoxins BthTX-I and II

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    This article reports the anti-inflammatory effect of Blutaparon portulacoides (B. portulacoides), specifically the ethanolic extract of its aerial parts, on the edema formation and leukocyte influx caused by Bothrops jararacussu (B. jararacussu) snake venom and Bothropstoxin-I and II (BthTX-I and II) isolated from this venom as an alternative treatment for Bothrops snakebites. The anti-inflammatory effect of B. portulacoides ethanolic extract was compared with an animal group pretreated with dexamethasone. B. portulacoides ethanolic extract significantly inhibited paw edema induced by B. jararacussu venom and by BthTX-I and II. Also, results demonstrated that the extract caused a reduction of the leukocyte influx induced by BthTX-I. However, the extract was not capable of inhibiting the leukocyte influx induced by the venom and by BthTX-II. In conclusion, these results suggest that the ethanolic extract of this plant possess components able to inhibit or inactivate toxins present in B. jararacussu venom, including its myotoxins, responsible for the edema formation. However, the leukocyte migration caused by the venom and BthTX-II was not inhibited by the plant, probably due to the different mechanisms involved in the edema formation and leukocyte influx. This is the first report of B. portulacoides extract as anti-inflammatory against snake venoms and isolated toxins

    Harnessing Higher-Order (Meta-)Logic to Represent and Reason with Complex Ethical Theories

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    The computer-mechanization of an ambitious explicit ethical theory, Gewirth's Principle of Generic Consistency, is used to showcase an approach for representing and reasoning with ethical theories exhibiting complex logical features like alethic and deontic modalities, indexicals, higher-order quantification, among others. Harnessing the high expressive power of Church's type theory as a meta-logic to semantically embed a combination of quantified non-classical logics, our work pushes existing boundaries in knowledge representation and reasoning. We demonstrate that intuitive encodings of complex ethical theories and their automation on the computer are no longer antipodes.Comment: 14 page
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