1,458 research outputs found
ICT in Education: pedagogical challenges and conflicts with WEB 2.0
O artigo apresentado discute desafios e conflitos vivenciados por professores perante as sempre novas tecnologias de informação e comunicação (TIC), em especial a WEB 2.0. Compreender o processo de inserção das TIC na educação deve ser uma ação refletida, construída e partilhada. Relatamos alguns usos da WEB 2.0 na educação, compreendendo que esta pode potencializar os processos de ensino e aprendizagem. Sugerimos estratégias pedagógicas que possibilitam aprendizagens mais prazerosas e contextualizadas no currículo. Concluímos que é a construção de saberes em colaboração o maior tesouro a encontrar na WEB 2.0.The article discusses the challenges and conflicts experienced by teachers facing the always new information and communication technologies (ICT), as the the Web 2.0. Understanding that the process of integration of ICT in education must be a reflexive action,,built and shared. We report on some use of Web 2.0 in education to understand that this can enhance the teaching and learning processes. We suggest teaching strategies that enable contextualized learning more enjoyable and integrated in the curriculum. We conclude that it is the construction of knowledge in collaboration the greatest treasure found in Web 2.0.Universidade do Minho. Centro de Investigação em Educação (CIED
Estudo comparativo sobre métodos de geração de modelos geométricos por análise de elementos finitos
The aim of this study was to assess the influence of different methods for generating geometric models on stress values and distributions of endodontically treated teeth using a three-dimensional finite element analysis (3D-FEA). An endodontically treated human maxillary canine restored with glass fiber post and ceramic-fused-to-metal crown was scanned by microcomputed tomography and three-dimensionally reconstructed. Based on the microcomputed tomography images, 2 geometric models were generated and divided into the following groups: Group GCAD - only the root dentine was reconstructed based on a microcomputed tomography image while the remaining structures were generated by GCAD software simulation, and Group GTC - the whole assembly was obtained from scanning and rehabilitated by microcomputed tomography. Loading of 180N at 45° of the tooth long axis was applied on the lingual surface of the incisal third and the models were supported by a periodontal ligament fixed into the 3 axes of the Cartesian system (x=y=z=0). von Mises stress (VMS) were calculated. Differences in stress value and distribution between the generation methods of the geometric models were found. The lowest ratio difference in GTC/GCAD was for resin cement and core. Thus, the method for generation of the geometric model in finite element analysis was found to influence the research results, suggesting difference between the methods proposed.O objetivo deste estudo foi avaliar a influência de diferentes métodos para a geração de modelos geométricos em valores de tensões e distrubuições de dentes tratados endodônticamente, utilizando-se uma análise tridimensional de elementos finitos (3D-FEA). Canino superior humano tratado endodonticamente, restaurado com pino de fibra de vidro e coroa metalocerâmica foi escaneado por meio de microtomografia computadorizada e reconstruído tridimensionalmente. Baseadas nas imagens de microtomografia computadorizada, foram gerados 2 modelos geométricos e divididos nos seguintes grupos: grupo GCAD-apenas a dentina radicular foi reconstruída baseada na imagem obtida por meio de microtomografia computadorizada, enquanto as estruturas remanescentes foram geradas por simulação de software de CAD, e grupo GTC-todo conjunto inteiro foi obtido do escaneamento e reabilitado pela microtomografia computadorizada. O carregamento de 180N em 45° do longo eixo do dente foi aplicado na superfície lingual do terço incisal e os modelos foram suportados por um ligamento periodontal fixado nos 3 eixos do sistema cartesiano (x = y = z = 0). Tensões equivalents de von Mises (VMS) foram calculados. Foram encontradas diferenças no valor de tensões e distribuição entre os métodos de geração dos modelos geométricos. A menor razão entre GTC/GCAD foi para o cimento de resinoso e núcleo. Assim, verificou-se que o método de geração do modelo geométrico na análise de elementos finitos influenciou os resultados da pesquisa, sugerindo melhores resultados para o método GCAD
Response of Staphylococcus epidermidis biofilms cells to the effect of farnesol
Objective:Staphylococcus epidermidis is a leading cause of medical-device-related infections, especially in immunocompromised patients. The treatment of these infections is further complicated by the emergence of multiresistant strains. The ability of S. epidermidis to form biofilms on biotic and abiotic surfaces is believed to contribute significantly to the pathogenesis of these infections. Biofilms are notoriously difficult to eradicate and are often resistant to systemic antibiotic therapy. Recently, farnesol has been described as having antimicrobial properties, and therefore a possible action on the prevention of S. epidermidis related infections. In previous studies it was shown that 300 microM farnesol was effective against S. epidermidis planktonic cells but having only a slight effect on biofilm cells. So, the goal of this study was to assess the antimicrobial activity of higher farnesol concentrations (1 and 100 mM) against biofilm cells of S. epidermidis.
Methods: Two S. epidermidis strains biofilm-producing (9142 and 1457) were used in this study. Farnesol (0, 1 mM, 100 mM) was added to 24 h biofilm cells. Biofilm formation was assessed through crystal violet (CV) staining that measure total biomass of biofilm and cellular viability through XTT and colony-forming units (CFU/ml).
Results: The results didn't show a significant effect of both farnesol concentrations on biofilm biomass and activity. In fact, biofilm cell reduction was less than 2 Log, similarly to most antibiotics (e.g. tetracycline and vancomycin).
Conclusion: Although the reduction promoted by farnesol was less than 3 Log as requested for an antibiotic agent, its efficacy is similar to vancomycin. On account of that we are now testing the combined effect of farnesol with agents that disrupt the biofilm matrix
A toxicidade medicamentosa: fibrose pulmonar após o uso de amiodarona, relato de dois casos.
Trabalho de Conclusão de Curso - Universidade Federal de Santa Catarina, Centro de Ciências da Saúde, Departamento de Clínica Médica, Curso de Medicina, Florianópolis, 198
Effect of N-Acetylcysteine alone and in combination with rifampicin on Staphylococcus epidermidis biofilms
Medical device-associated infections caused by pathogens such as Staphylococcus epidermidis might involve
biofilm formation and those are particularly challenging. The involvement of antibiotic resistant Staphylococci,
exacerbates the problem. Rifampicin cannot be used as a single agent to treat infections because of the rapid
selection of resistant mutants. However, combinations of rifampicin with other anti-staphylococcal agents
could prevent the emergence of rifampicin resistance during therapy. N-acetylcisteine (NAC) decreases biofilm
formation by a variety of bacteria and reduces the production of extracellular polysaccharide matrix. The goal
of this study was to assess the antimicrobial activity of NAC in combination with rifampicin against biofilm
of S. epidermidis. Two S. epidermidis strains biofilm-producing (9142 and 1457) were used in this study.
1xMIC (4mg/ml) and 10xMIC (40mg/ml) of NAC and 10mg/l of rifampicin, based on preliminary in vitro data,
were added to 24h biofilm cells. Biofilm susceptibility to tested antimicrobial agents was assessed through
scanning electron microscopy, crystal violet staining (total biofilm biomass) and cellular viability through XTT
and colony forming units (CFU). The effect of NAC 1xMIC was similar to that of the control. Rifampicin, NAC
10xMIC alone and NAC-rifampicin combination (independently of NAC concentration used) showed significant
bactericidal effect, promoting a 3-4 log10 decrease in biofilm cells. In conclusion, the results didn’t point to any
synergistic effect between the two agents. Nevertheless, NAC seems to be a possible alternative to antibiotics
in the treatment of infections associated to S. epidermidis biofilm
Staphylococcus epidermidis biofilms control by N-acetylcysteine and rifampicin
Medical device-associated infections caused by Staphylococcus epidermidis usually involve biofilm formation and its eradication is particularly challenging. Although rifampicin has been proving to be one of the most effective antibiotics against S. epidermidis biofilms, its use as a single agent can lead to the acquisition of resistance. Therefore, we assessed the combined effect of rifampicin with N-acetylcysteine (NAC) known by its mucolytic effect, in the control of S. epidermidis biofilms. Biofilms of 2 S. epidermidis strains (9142 and 1457) were treated with 1x minimum inhibitory concentration (4 mg/mL) and 10x minimum inhibitory concentration (40 mg/mL) of NAC and 10 mg/L (peak serum) of rifampicin alone and in combination. NAC at 40 mg/L alone or in combination with rifampicin (10 mg/L) significantly reduced (4 log10) the number of biofilm cells. Considering their different modes of action, the association of NAC with rifampicin constitutes a promising therapeutic strategy in the treatment of infections associated to S. epidermidis biofilms.Bruna Leite acknowledges the financial support of ISAC/Program Erasmus Munds External Cooperation and the IBB-Institute for Biotechnology and Bioengineering, Centre of Biological Engineering, University of Minho, Campus of Gualtar
N-acetylcysteine and vancomycin alone and in combination against staphylococci biofilm
Introduction: The ability of staphylococci to produce biofilm is an important virulence mechanism that allows bacteria both to adhere and to live on artificial surfaces and to resist to the host immune factors and antibiotics. Staphylococcal infections have become increasingly difficult to treat due their antibiotic resistance. Therefore, there is a continuous need for new and effective treatment alternatives against staphylococcal infections. The main goal of this study was to test N-acetylcysteine (NAC) and vancomycin alone and in combination against S. epidermidis and S. aureus biofilms. Methods: Biofilms were treated with NAC at minimum inhibitory concentration (MIC) and 10 × MIC concentrations and vancomycin at MIC and peak serum concentrations. Results: The use of NAC 10 × MIC alone showed a significant antibactericidal effect, promoting a 4-5 log10 CFU/ mL reduction in biofilm cells. The combination of NAC 10 × MIC with vancomycin (independently of the concentration used) reduced significantly the number of biofilm cells for all strains evaluated (5-6 log10). Conclusion: N-acetylcysteine associated to vancomycin can be a potential therapeutic strategy in the treatment of infections associated to biofilms of S. epidermidis or S. aureus.(undefined
Microfluidics-based automated genotyping of Saccharomyces Cerevisiae strain by interdelta sequence typing : an interlaboratory comparasion
High-throughput molecular characterization of microbial isolates requires the application of automated microfluidic
electrophoresis. We herein evaluate the factors that affect interlaboratory reproducibility of interdelta sequence typing for
Saccharomyces cerevisiae strain delimitation, using microfluidic electrophoresis (Caliper Lab Chip
®
). This approach is
necessary for the constitution of bio-databanks, equitable sharing of genotypic data among laboratories, for biodiversity
conservation and sustainable development of genetic resources. Delta sequences are 300 bp regions flanking
retrotransposons Ty1 and Ty2 of S. cerevisiae, occurring also as separate elements dispersed throughout the genome. PCRbased interdelta sequence typing has a high discriminatory power [1], generating polymorphic banding patterns. Our
approach included 12 genetically diverse S. cerevisiae strains, two different Taq polymerases (commercial and in-house
cloned/prepared) and two different thermal cyclers. PCR amplifications were performed in two laboratories, resulting in a total
of 384 electrophoretic banding patterns (32 replicates for each strain). From the combinations between strains, Taq
polymerase, thermal cycler and laboratory, a total of 60 different groups was obtained. Data were analyzed in terms of the
fragment sizes (bp), absolute and relative concentrations of each band. Due to the lack of normality (Kolmogorov-Smirnov
and Shapiro-Wilk tests) and the homogeneity of variances (Levene's test), the ANOVA test was not applied. The nonparametric alternative, Kruskal-Wallis one-way analysis of variance was used to test the equality of the medians among the
different groups. By rejecting the null hypotheses with a p-value < 0.001, we performed multiple pairwise comparisons using
the method proposed by Conover and Iman [2], based on a t-Student distribution to search for the origins of the differences.
The data obtained revealed that both the performance of experiments in two independent laboratories and the use of different
Taq polymerases introduced significant variability between the respective replicates. The use of in-house cloned/prepared
Taq polymerase was associated with highest variability, pointing to the need for careful experimental standardization of PCRbased interdelta sequence analysis.Portuguese Science and Technology Foundation (PTDC/AGR-ALI/103392/2008)European Community´s Seventh Framework Programme (FP7/2007-2013) - grant agreement nº 23245
Formação docente em aplicativos Google Drive: desafios colocados à prática docente
Este trabalho pretende contribuir para abrir novas perspectivas, ao discutir, apresentar possibilidades e limitações quanto ao uso dos aplicativos Google Drive dirigido aos professores (formação continuada), afetos à Secretaria de Educação e Qualidade de Ensino e no Instituto Federal do Amazonas. A metodologia adotada prevê um estudo de caso exploratório-descritivo. Quanto aos procedimentos e técnicas vai ser realizada, pesquisa bibliográfica, intervenção por via de oficinas a aproximadamente 20 professores das componentes curriculares Matemática e Língua Portuguesa. Espera-se que os docentes ampliem a produção do conhecimento, melhoria do processo ensino e aprendizagem com a adoção dos aplicativos da Google
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