288 research outputs found
Heterofucans from the Brown Seaweed Canistrocarpus cervicornis with Anticoagulant and Antioxidant Activities
Fucan is a term used to denominate a family of sulfated polysaccharides rich in sulfated l-fucose. We extracted six fucans from Canistrocarpus cervicornis by proteolytic digestion followed by sequential acetone precipitation. These heterofucans are composed mainly of fucose, glucuronic acid, galactose and sulfate. No polysaccharide was capable of prolonging prothrombin time (PT) at the concentration assayed. However, all polysaccharides prolonged activated partial thromboplastin time (aPTT). Four sulfated polysaccharides (CC-0.3/CC-0.5/CC-0.7/CC-1.0) doubled aPTT with only 0.1 mg/mL of plasma, only 1.25-fold less than Clexane®, a commercial low molecular weight heparin. Heterofucans exhibited total antioxidant capacity, low hydroxyl radical scavenging activity, good superoxide radical scavenging efficiency (except CC-1.0), and excellent ferrous chelating ability (except CC-0.3). These results clearly indicate the beneficial effect of C. cervicornis polysaccharides as anticoagulants and antioxidants. Further purification steps and additional studies on structural features as well as in vivo experiments are needed to test the viability of their use as therapeutic agents
Gestão democrática da educação, participação política e eleição de diretores: uma análise a partir da experiência das ocupações de escolas no Rio de Janeiro
É nosso objetivo analisar dimensões de gestão de escola, de participação política dos estudantes e da relação com a comunidade escolar a partir das ocupações de escolas do Rio de Janeiro, em 2016. Alicerçados na experiência de dois estudantes e de um dos autores do texto, utilizamos como referencial teórico-metodológico a filosofia da práxis e do legado braudeliano. Como estratégia de pesquisa, empregamos a pesquisa-ação e entrevistas. Concluímos que esta experiência foi fundamental para a vida dos estudantes, tanto no momento do acontecimento, quanto em seus desdobramentos
Prevalence and Progression of Ametropias in Medical Students
Background: Uncorrected refractive errors (Myopia, Hyperopia and Astigmatism) are one of the main causes of poor vision, attributing to 43% of vision deficiencies. Myopia is the most common visual disorder in the world and can progress up until the age of 20-25, when many people are in university. The etiological factors that cause myopia are still unclear and deserve to be studied. Our aim was to identify the prevalence of ametropias and self-perception of ophthalmic health in medical students at the Centro Universitário Saúde ABC/FMABC.
Methods: This is a cross-sectional study with data collected at Centro Universitário Saúde ABC/FMABC from medical students. A total of 232 students participated in the survey, from the 1st to the 4th year of study. Data was obtained through a questionnaire, which evaluates ophthalmologic health, ametropia, and self-perception.
Results: It was observed that 74.57% of the students had some type of ametropia, myopia being the most recurrent (59.05%). The study shows significant data of an increase in the grade of students from 1st to 4th grade throughout college. It was observed that the average daily study time of the students was 9.68 hours and abuse in the use of electronic devices.
Conclusion: This study presented a high prevalence of ametropias among medical students at the Centro Universitário ABC/FMABC, in addition to a high prevalence of multifactorial myopia and an increased need to update their diopters (degrees) during the course of university
merlin, an improved framework for the reconstruction of high-quality genome-scale metabolic models
Genome-scale metabolic models have been recognised as useful tools for better understanding living organisms metabolism. merlin (https://www.merlin-sysbio.org/) is an open-source and user-friendly resource that hastens the models reconstruction process, conjugating manual and automatic procedures, while leveraging the user's expertise with a curation-oriented graphical interface. An updated and redesigned version of merlin is herein presented. Since 2015, several features have been implemented in merlin, along with deep changes in the software architecture, operational flow, and graphical interface. The current version (4.0) includes the implementation of novel algorithms and third-party tools for genome functional annotation, draft assembly, model refinement, and curation. Such updates increased the user base, resulting in multiple published works, including genome metabolic (re-)annotations and model reconstructions of multiple (lower and higher) eukaryotes and prokaryotes. merlin version 4.0 is the only tool able to perform template based and de novo draft reconstructions, while achieving competitive performance compared to state-of-the art tools both for well and less-studied organisms.Centre of Biological Engineering (CEB, UMinho);
Portuguese Foundation for Science and Technology
(FCT) under the scope of the strategic funding of
UIDB/04469/2020 unit; this work is a result of the
project 22231/01/SAICT/2016: Biodata.pt Infraestrutura Portuguesa de Dados Biologicos, supported by the ´
PORTUGAL 2020 Partnership Agreement, through the
European Regional Development Fund (ERDF); FCT for
providing PhD scholarships [DFA/BD/08789/2021 J.C,
DFA/BD/8076/2020 E.C., SFRH/BD/139198/2018 to
F.C., SFRH/BD/131916/2017 R. Rodrigues]; FCT for the
Assistant Research contract of Oscar Dias obtained under
CEEC Individual 2018.info:eu-repo/semantics/publishedVersio
Correction: Costa et al. Glycerol and Catalysis by Waste/Low-Cost Materials—A Review. Catalysts 2022, 12, 570
Heterofucan from Sargassum filipendula Induces Apoptosis in HeLa Cells
Fucan is a term used to denominate a family of sulfated polysaccharides rich in sulfated l-fucose. Heterofucan SF-1.5v was extracted from the brown seaweed Sargassum filipendula by proteolytic digestion followed by sequential acetone precipitation. This fucan showed antiproliferative activity on Hela cells and induced apoptosis. However, SF-1.5v was not able to activate caspases. Moreover, SF-1.5v induced glycogen synthase kinase (GSK) activation, but this protein is not involved in the heterofucan SF-1.5v induced apoptosis mechanism. In addition, ERK, p38, p53, pAKT and NFκB were not affected by the presence of SF-1.5v. We determined that SF-1.5v induces apoptosis in HeLa mainly by mitochondrial release of apoptosis-inducing factor (AIF) into cytosol. In addition, SF-1.5v decreases the expression of anti-apoptotic protein Bcl-2 and increased expression of apoptogenic protein Bax. These results are significant in that they provide a mechanistic framework for further exploring the use of SF-1.5v as a novel chemotherapeutics against human cervical cancer
Produção biotecnológica de poli-hidroxialcanoatos para a geração de polímeros biodegradáveis no Brasil
In recent years, several studies have been developed in Brazil to produce biodegradable materials. A particular family of bacterial polymers, the polyhydroxyalkanoates (PHA), has received special attention. PHAs are thermoplastic, biodegradable, biocompatible, are synthesised from renewable resources and can substitute petrochemical plastics in some applications. Different aspects have been focused to increase productivity and to reduce the cost of PHA production: bacterial improvement, use of industrial by-products as raw material, bioreactor design, process operation strategies, downstream process, mathematical modelling, polymer characterisation, application and biodegradability of blends. A production process was transferred to industry and studies to produce new PHA by controlling monomer composition are in progress. All these aspects are presented in this review
Glycerol and Catalysis by Waste/Low-Cost Materials—A Review
The growing global demand for renewable energy sources can be reached using biofuels such as biodiesel, for example. The most used route to produce biodiesel is the transesterification reaction of oils or fats with short-chain alcohols, generating fatty acid esters (biodiesel) and a very important by-product, glycerol (Gly). Gly is widely used in different sectors of the industry, and in order to add value to this by-product, heterogeneous catalysis becomes a relevant tool, whether to transform glycerol into other chemical products of interest or even use it in the production of catalysts. Among the several studies found in the literature, the use of low-cost materials and/or wastes from the most diverse activities to prepare active catalytic materials for the transformation of Gly has been increasingly reported due to its valuable advantages, especially related to the cost of raw materials and environmental aspects. Thus, this brief review article presents the relationship between catalysis, low-cost materials, waste, and glycerol, through different studies that show glycerol being transformed through reactions catalyzed by materials produced from low-cost sources/waste or with the glycerol itself used as a catalyst
Early detection of weed in sugarcane using convolutional neural network
Weed infestation is an essential factor in sugarcane productivity loss. The use of remote sensing data in conjunction with Artificial Intelligence (AI) techniques, can lead the cultivation of sugarcane to a new level in terms of weed control. For this purpose, an algorithm based on Convolutional Neural Networks (CNN) was developed to detect, quantify, and map weeds in sugarcane areas located in the state of Alagoas, Brazil. Images of the PlanetScope satellite were subdivided, separated, trained in different scenarios, classified and georeferenced, producing a map with weed information included. Scenario one of the CNN training and test presented overall accuracy (0,983), and it was used to produce the final mapping of forest areas, sugarcane, and weed infestation. The quantitative analysis of the area (ha) infested by weed indicated a high probability of a negative impact on sugarcane productivity. It is recommended that the adequacy of CNN’s algorithm for Remotely Piloted Aircraft (RPA) images be carried out, aiming at the differentiation between weed species, as well as its application in the detection in areas with different culture crop
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