Time filter

Source Type

Sorocaba, Brazil

Spencer F.A.,McMaster University | Lopes L.C.,University of Sorocaba | Kennedy S.A.,McMaster University | Guyatt G.,McMaster University
BMJ Open | Year: 2014

Objectives: To provide a comprehensive comparison of patent foramen ovale (PFO) closure versus medical therapy in patients with cryptogenic stroke or transient ischaemic attack (TIA) and demonstrated PFO. Design: Systematic review with complete case metaanalysis and sensitivity analyses. Data sources included MEDLINE and EMBASE from 1980 up to May 2013. All randomised controlled trials (RCTs) comparing treatment with percutaneous catheter-based closure of PFO to anticoagulant or antiplatelet therapy in patients with cryptogenic stroke or TIA and echocardiographically confirmed PFO or atrial septal defect (ASD) were eligible. Participants: 1967 participants with prior stroke or TIA and echocardiographically confirmed PFO or ASD. Primary outcome measures: The primary outcome of interest was recurrence of ischaemic stroke. We utilised data from complete cases only for the primary endpoint and combined data from trials to estimate the pooled risk ratio (RR) and associated 95% CIs calculated using random effects models. Results: We identified 284 potentially eligible articles of which three RCTs including 2303 patients proved eligible and 1967 patients had complete data. Of the 1026 patients randomised to PFO closure and followed to study conclusion 22 experienced non-fatal ischaemic strokes, as did 34 of 941 patients randomised to medical therapy (risk ratio (RR) 0.61, 95% CI 0.34 to 1.07; heterogeneity: p=0.34, I2=8%, confidence in estimates low due to risk of bias and imprecision). Analyses for ischaemic stroke restricted to 'per-protocol' patients or patients with concomitant atrial septal aneurysm did not substantially change the observed RRs. Complication rates associated with either PFO closure or medical therapy were low. Conclusions: Pooled data from three RCTs provides insufficient support that PFO closure is preferable to medical therapy for secondary prevention of cryptogenic stroke in patients with PFO.

Petruci J.F.D.S.,Sao Paulo State University | Pereira E.A.,University of Sorocaba | Cardoso A.A.,Sao Paulo State University
Journal of Agricultural and Food Chemistry | Year: 2013

The use of chemical preservative compounds is common in the food products industry. Caramel color is the most usual additive used in beverages, desserts, and breads worldwide. During its fabrication process, 2- and 4-methylimidazole (MeI), highly carcinogenic compounds, are generated. In these cases, the development of reliable analytical methods for the monitoring of undesirable compounds is necessary. The primary procedure for the analysis of 2- and 4-MeI is using LC- or GC-MS techniques. These procedures are time-consuming and require large amounts of organic solvents and several pretreatment steps. This prevents the routine use of this procedure. This paper describes a rapid, efficient, and simple method using capillary electrophoresis (CE) for the separation and determination of 2- and 4-MeI in caramel colors. The analyses were performed using a 75 μm i.d. uncoated fused-silica capillary with an effective length of 40 cm and a running electrolyte consisting of 160 mmol L-1 phosphate plus 30% acetonitrile. The pH was adjusted to 2.5 with triethylamine. The analytes were separated within 6 min at a voltage of 20 kV. Method validation revealed good repeatability of both migration time (<0.8% RSD) and peak area (<2% RSD). Analytical curves for 2- and 4-MeI were linear in the 0.4-40 mg L-1 concentration interval. Detection limits were 0.16 mg L-1 for 4-MeI and 0.22 mg L-1 for 2-MeI. The extraction recoveries were satisfactory. The developed method showed many advantages when compared to the previously used method. © 2013 American Chemical Society.

Christianini A.V.,University of Campinas | Christianini A.V.,University of Sorocaba | Christianini A.V.,Federal University of Sao Carlos | Oliveira P.S.,University of Campinas
Journal of Ecology | Year: 2010

A substantial portion of the crop of fruiting trees falls beneath parent plants as a result of dispersal failure. Such diaspores are considered as waste because the likelihood of plant recruitment is usually very small close to parent trees. However, many animals may rescue fallen diaspores and provide them with another chance of dispersal and establishment. We investigated the effectiveness of two broad types of seed dispersal vectors for the regeneration of Xylopia aromatica in the Brazilian cerrado savanna: birds that remove diaspores from plant canopies and ants that harvest diaspores on the ground under the parent plant (as rescuers) or from bird feces (as secondary dispersers). Birds removed a mean of 32% of the crop from plant canopies, but removal was independent of crop size. A large part of the crop (mean of 25%) landed beneath parent plants or was dropped after manipulation by vertebrate frugivores as viable diaspores. Ants from at least five genera removed most fallen diaspores (up to 83%) within 24 h. Ants influenced the fate of a large amount of the crop, and for some trees ants removed as many diaspores as birds. Large ants rescued some diaspores to distances beyond the parent plant crown, but birds may remove diaspores 40-fold farther. However, seedlings of X. aromatica were only found close to nests of large ants, probably due to diaspore rescuing and/or directed secondary dispersal by certain ant groups following primary dispersal by birds. Although an unknown percentage of seeds was lost to granivorous ants, diaspore removal by ants potentially enhances the likelihood of plant recruitment due to distance-related benefits and directed dispersal to ant nests, while birds play a premier role in long-distance seed dispersal and metapopulation dynamics. Synthesis. Birds and ants provide complementary seed dispersal at different spatial scales to X. aromatica. Since ants remove most fallen diaspores beneath parent plants, the use of diaspore removal rates from plant canopy as a surrogate of plant fitness may be misleading. By acting as secondary dispersers, ants may also provide a fine-tuned dispersal following long-distance dispersal by birds (i.e. diplochory). © 2010 The Authors. Journal compilation © 2010 British Ecological Society.

Seabra A.B.,Federal University of Sao Paulo | Pasquoto T.,Federal University of Sao Carlos | Ferrarini A.C.F.,Federal University of Sao Paulo | Santos M.D.C.,Federal University of Sao Paulo | And 2 more authors.
Chemical Research in Toxicology | Year: 2014

Iron oxide magnetic nanoparticles have been proposed for an increasing number of biomedical applications, such as drug delivery. To this end, toxicological studies of their potent effects in biological media must be better evaluated. The aim of this study was to synthesize, characterize, and examine the potential in vitro cytotoxicity and genotoxicity of thiolated (SH) and S-nitrosated (S-NO) iron oxide superparamagnetic nanoparticles toward healthy and cancer cell lines. Fe3O4 nanoparticles were synthesized by coprecipitation techniques and coated with small thiol-containing molecules, such as mercaptosuccinic acid (MSA) or meso-2,3-dimercaptosuccinic acid (DMSA). The physical-chemical, morphological, and magnetic properties of thiol-coating Fe3O4 nanoparticles were characterized by different techniques. The thiol groups on the surface of the nanoparticles were nitrosated, leading to the formation of S-nitroso-MSA- or S-nitroso-DMSA-Fe 3O4 nanoparticles. The cytotoxicity and genotoxicity of thiolated and S-nitrosated nanoparticles were more deeply evaluated in healthy (3T3, human lymphocytes cells, and chinese hamster ovary cells) and cancer cell lines (MCF-7). The results demonstrated that thiol-coating iron oxide magnetic nanoparticles have few toxic effects in cells, whereas S-nitrosated-coated particles did cause toxic effects. Moreover, due to the superaramagnetic behavior of S-nitroso-Fe3O4 nanoparticles, those particles can be guided to the target site upon the application of an external magnetic field, leading to local toxic effects in the tumor cells. Taken together, the results suggest the promise of S-nitroso-magnetic nanoparticles in cancer treatment. © 2014 American Chemical Society.

de Barros Filho R.M.,Design School and INAP Faculty | Mendes L.M.,Federal University of Lavras | Novack K.M.,Federal University of Ouro Preto | Aprelini L.O.,Federal University of Ouro Preto | Botaro V.R.,University of Sorocaba
Industrial Crops and Products | Year: 2011

The expansion of Brazilian agricultural production was very important in the last decade. A number of waste residues were produced showing an enormous potential for industrial crops and products. Sugarcane bagasse is the most important one and it has been investigated for chipboard panel's preparation. In this sense, this work aims to develop, characterize and compare chipboard panels made with sugarcane bagasse with urea formaldehyde (UF) and melamine formaldehyde (MF) resins. Panels were obtained with a mixture of sugarcane bagasse and particles, like pine or eucalyptus, with and without paraffin in the formulation. Nine different types of panels have been made, all with 9% in resin mix, under a pressing cycle of 4.0MPacm2, and temperature of 160°C. Under physical tests, the panels complied with the American Standard CS 236-66 for trading chipboards of medium density and, in most cases the results obtained were lower than the ones raised in the literature. Under mechanical tests, that same standard was not complied with and, in most cases the results were close to or higher than those obtained in the literature. © 2010 Elsevier B.V.

Discover hidden collaborations