19 research outputs found
Comparação de métodos convencional e alternativo para determinar Cu, Fe, Mn e Zn em extratos de solos obtidos com solução de mehlich-1
Comparação de métodos convencional e alternativo para determinação de sódio, potássio e fósforo em extratos de solos obtidos com solução de mehlich-1
Performance of two-dimensional Doppler echocardiography for the assessment of infarct size and left ventricular function in rats
Uso de ICP OES e titrimetria para a determinação de cálcio, magnésio e alumínio em amostras de solos
Avaliação dos solos e das águas nas áreas de influência de disposição de resíduos sólidos urbanos de Humaitá, Amazonas
Technology and innovation in teaching genetics: project-based learning in the construction of cloning strategies
Project-based learning (PBL) is an active student-centred form of instruction that uses a project as a central
vehicle of knowledge acquisition. Besides its high potential in developing structured thinking, constructive
investigations, and improving the students’ responsibility and autonomy, this methodology is not strongly
applied in Science degrees, where standardised tests and fixed protocol-driven laboratorial applications are still
the dominant ways to assess academic achievement. This research involved the implementation of a PBL in
teaching gene cloning strategies to third-year students of the BSc Biotechnology course. The methodology was
conducted in four stages, integrating two curricular units, Genetic Engineering, and Integrated-Laboratories VB.
Firstly, the project was conceptualised in Genetic Engineering theoretical classes with tutorial support. Secondly,
the planned protocol was applied in the laboratory with tutor supervision. Thirdly, collaboration,
communication, and reflection skills were emphasized with a poster presentation. Finally, an evaluation
questionnaire was applied. The study's main findings were: 1) none of the students have ever had PBL, 2) the
majority of students achieved better comprehension and acquired stronger theoretical knowledge, 3) they gained
more autonomy in the laboratory, and 4) strongly recommended this methodology. However, students also
acknowledged that the PBL approach was more time and study demanding.A aprendizagem baseada em projetos (ABP) é uma forma ativa de ensino centrada no estudante que usa um
projeto como veículo central de aquisição de conhecimento. Apesar do elevado potencial para desenvolver um
pensamento estruturado, investigações construtivas e promover responsabilidade e autonomia, esta metodologia
não é usualmente aplicada nas licenciaturas em Ciências, onde testes padronizados e práticas laboratoriais com
protocolos fixos ainda são as formas dominantes de avaliação. Este estudo envolveu a implementação da ABP no
ensino de estratégias de clonagem, com estudantes do terceiro ano da Licenciatura em Biotecnologia. A
metodologia foi desenvolvida em quatro etapas, integrando duas unidades curriculares, Engenharia Genética e
Laboratórios VB. Inicialmente, o projeto foi conceptualizado nas aulas teóricas de Engenharia Genética com
suporte tutorial. Posteriormente, o protocolo planeado foi implementado no laboratório com supervisão. Em
terceiro, as competências de colaboração, comunicação e reflexão foram enfatizadas com a apresentação de um
poster. Por fim, foi aplicado um questionário de avaliação. As principais conclusões foram: 1) nenhum dos
estudantes tinha experienciado a ABP, 2) a maioria compreendeu e adquiriu conhecimentos teóricos mais sólidos,
3) adquiriram mais autonomia no laboratório e 4) recomendam fortemente. No entanto, os estudantes
reconheceram que a ABP consistiu numa aprendizagem mais exigente.info:eu-repo/semantics/publishedVersio
Performance of two-dimensional Doppler echocardiography for the assessment of infarct size and left ventricular function in rats
Although echocardiography has been used in rats, few studies have determined its efficacy for estimating myocardial infarct size. Our objective was to estimate the myocardial infarct size, and to evaluate anatomic and functional variables of the left ventricle. Myocardial infarction was produced in 43 female Wistar rats by ligature of the left coronary artery. Echocardiography was performed 5 weeks later to measure left ventricular diameter and transverse area (mean of 3 transverse planes), infarct size (percentage of the arc with infarct on 3 transverse planes), systolic function by the change in fractional area, and diastolic function by mitral inflow parameters. The histologic measurement of myocardial infarction size was similar to the echocardiographic method. Myocardial infarct size ranged from 4.8 to 66.6% when determined by histology and from 5 to 69.8% when determined by echocardiography, with good correlation (r = 0.88; P < 0.05; Pearson correlation coefficient). Left ventricular diameter and mean diastolic transverse area correlated with myocardial infarct size by histology (r = 0.57 and r = 0.78; P < 0.0005). The fractional area change ranged from 28.5 ± 5.6 (large-size myocardial infarction) to 53.1 ± 1.5% (control) and correlated with myocardial infarct size by echocardiography (r = -0.87; P < 0.00001) and histology (r = -0.78; P < 00001). The E/A wave ratio of mitral inflow velocity for animals with large-size myocardial infarction (5.6 ± 2.7) was significantly higher than for all others (control: 1.9 ± 0.1; small-size myocardial infarction: 1.9 ± 0.4; moderate-size myocardial infarction: 2.8 ± 2.3). There was good agreement between echocardiographic and histologic estimates of myocardial infarct size in rats