649 research outputs found

    Neuro-Behçet: MR study of a group of patients

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    Acta Med Port. 2006 Nov-Dec;19(6):494-8. Epub 2007 May 14. [Neuro-Behçet: MR study of a group of patients] [Article in Portuguese] Ramos C, Sá G, Tedim Cruz V, Lopes A, Xavier J, Cruz R. Serviço de Neurorradiologia, Hospital Geral de Santo António, Porto, Portugal. Abstract Behçet's disease is a chronic inflammatory, multisystemic disease of unknown aetiology. Central nervous system involvement occurs in a variable proportion of cases (4 to 49%) and is due to intracranial hypertension secondary to dural sinus thrombosis, inflammatory parenquimal lesions or recurrent meningoencephalitis. We reviewed 12 patients, 7 men and 5 women, aged between 27 to 40 years at the time of diagnosis. Neurological manifestations were secondary to parenquimal lesions in 7 patients, meningoencephalitis in 3 patients (including one with extensive medullary lesion) and dural sinus thrombosis in 2. Magnetic Resonance (MR) findings in Neuro-Behçet are non-specific. Nevertheless, MR has a role in characterizing brain lesions topography, helping in the diagnosis and in the follow-up of these patients. PMID: 17583610 [PubMed - indexed for MEDLINE]Free Articl

    Molecular modeling and inhibitory activity of cowpea cystatin against bean bruchid pests.

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    Made available in DSpace on 2018-06-06T01:01:49Z (GMT). No. of bitstreams: 1 ID278851.pdf: 325253 bytes, checksum: 9561dcac2d70f9704f44dd57019d07c0 (MD5) Previous issue date: 2007-01-16bitstream/item/178117/1/ID-27885-1.pd

    Cluster Hybrid Monte Carlo Simulation Algorithms

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    We show that addition of Metropolis single spin-flips to the Wolff cluster flipping Monte Carlo procedure leads to a dramatic {\bf increase} in performance for the spin-1/2 Ising model. We also show that adding Wolff cluster flipping to the Metropolis or heat bath algorithms in systems where just cluster flipping is not immediately obvious (such as the spin-3/2 Ising model) can substantially {\bf reduce} the statistical errors of the simulations. A further advantage of these methods is that systematic errors introduced by the use of imperfect random number generation may be largely healed by hybridizing single spin-flips with cluster flipping.Comment: 16 pages, 10 figure

    An evolutionary algorithm for automated machine learning focusing on classifier ensembles: an improved algorithm and extended results

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    A large number of classification algorithms have been proposed in the machine learning literature. These algorithms have different pros and cons, and no algorithm is the best for all datasets. Hence, a challenging problem consists of choosing the best classification algorithm with its best hyper-parameter settings for a given input dataset. In the last few years, Automated Machine Learning (Auto-ML) has emerged as a promising approach for tackling this problem, by doing a heuristic search in a large space of candidate classification algorithms and their hyper-parameter settings. In this work we propose an improved version of our previous Evolutionary Algorithm (EA) – more precisely, an Estimation of Distribution Algorithm – for the Auto-ML task of automatically selecting the best classifier ensemble and its best hyper-parameter settings for an input dataset. The new version of this EA was compared against its previous version, as well as against a random forest algorithm (a strong ensemble algorithm) and a version of the well-known Auto-ML method Auto-WEKA adapted to search in the same space of classifier ensembles as the proposed EA. In general, in experiments with 21 datasets, the new EA version obtained the best results among all methods in terms of four popular predictive accuracy measures: error rate, precision, recall and F-measure

    In vitro digestion and stability assessment of b-lactoglobulin/riboflavin nanostructures

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    B-Lactoglobulin (b-Lg) is the major protein fraction of bovine whey serum and a primary gelling agent. b-Lg has a high nutritional value, is stable at low pH being highly resistant to proteolytic degradation in the stomach, besides, it has the ability of acting as an encapsulating agent. This study aims at assessing the ability of b-Lg nanostructures to associate a nutraceutical - i.e. riboflavin - and release it in a controlled manner throughout an in vitro gastrointestinal (GI) system. For this reason b-Lg nanostructures loaded with riboflavin were critically characterized in terms of their morphology (i.e. size, polydispersity, -potential and shape) by dynamic light scattering (DLS) and transmission electron microscopy (TEM), and efficiency to associate to riboflavin through spectrofluorimetry. Furthermore, these nanocomplexes were evaluated in an in vitro GI model, simulating the physiological conditions. Stable b-Lg nanostructures were obtained at pH 6, of spherical shape, characterized by particle size of 172±1 nm, low polydispersity (i.e. PDI of 0.06±0.02), -potential of -32±3 mV and association efficiency (AE) of 26±1 %. b-Lg nanostructures showed to be stable upon their passage throughout stomach (i.e. particle size, PDI and potential of 248±10 nm, 0.18±0.03 and 18±3 mV, respectively). Concerning their passage throughout the intestine, such nanostructures were mostly degraded in the duodenum. Regarding riboflavin, a release of about 11 % was observed after their passage through stomach, while 35 %, 38 % and 5 % were the released percentages of the total riboflavin associated observed after passage through duodenum, jejunum and ileum, respectively. Hence,b-Lg nanostructures showed to be suitable carriers for riboflavin until the intestine, where their degradation occurs. b-Lg also showed to be structurally stable, under food simulant conditions (yoghurt simulant, composed of 3 % acetic acid), over 14 days, with a protective effect upon riboflavin activity, releasing it in a 7 day period.Oscar L. Ramos, Ricardo N. Pereira and Ana C. Pinheiro gratefully acknowledge their Post-Doctoral grants (SFRH/BPD/80766/2011, SFRH/BPD/81887/2011 and SFRH/BPD/101181/2014, respectively) and Ana I. Bourbon gratefully acknowledge her Doctoral grant (SFRH/BD/73178/2010) to Fundacao para a Ciencia e a Tecnologia (FCT). The authors would like to acknowledge to Francisco Figueiredo from the Institute for Molecular and Cell Biology (IBMC), University of Porto, for assistance in taking the TEM pictures. The authors thank the FCT Strategic Project of UID/BIO/04469/2013 unit, COMPETE 2020 (POCI-01-0145-FEDER-006684), the project RECI/BBB-EBI/0179/2012 (FCOMP-01-0124-FEDER-027462), and the project "BioInd e Biotechnology and Bioengineering for improved Industrial and Agro-Food processes", REF. NORTE-07-0124-FEDER-000028, co-funded by the Programa Operacional Regional do Norte (ON. 2 - O Novo Norte), QREN, FEDER
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