Development of Chitosan and Poly (Vinyl Alcohol) Blended scaffolds for cell culture using supercritical fluids technology

Dissertação apresentada na Faculdade de Ciências e Tecnologia da Universidade Nova de Lisboa para obtenção do grau de Mestre em Mestrado Integrado em Engenharia Química e BioquímicaIn this work new porous materials for biomedical applications were developed using supercritical fluids (SCF) technology. In this context, two types of porous structures constituted by blends of chitosan and poly (vinyl alcohol) (PVA) using different ratios were prepared: membranes and three dimensional (3D) scaffolds. Phase inversion method using supercritical carbon dioxide (scCO2) as non-solvent was used to prepare porous membranes. The characterization of these materials showed that the presence of PVA in the membranes composition causes a decrease in porosity values and contact angle and an increase on pores interconnectivity and swelling degree. The mechanical properties were also modified by the existence of PVA in the membranes composition, increasing the elongation capacity of these structures and decreasing the supported break stresses. The 3D-scaffolds were prepared using freeze-drying technique and were treated with glutaraldehyde using a CO2-assisted crosslinking process. The optimization of the crosslinking process comprised the study of different glutaraldehyde concentrations and operation time. Morphological characterization showed that the casting solution concentration was a parameter with no influence in the 3Dscaffolds porosity neither on the pores interconnectivity. However, the PVA content in these matrices and the temperature used in the freeze-drying process determined their morphology. These highly porous structures were also submitted to dynamic swelling tests proving to be pH-sensitive with the capacity of swelling and deswelling when submitted to pH variations. The best response was obtained for scaffolds crosslinked with 1% (v/v) of glutaraldehyde during 10 minutes. Membranes and 3D-scaffolds were also tested for in vitro biodegradation using lysozyme and for cytotoxicity, proving to have potential applications in tissue engineering and regenerative medicine

How urban noise can influence the learning-teaching process. Quantitative and qualitative evaluation

The aim of this study is to evaluate the impact of urban noise and noise generated inside the buildings of elementary schools and its influence on the performance of their students. The sample is consists of the school EB1/JI in Prozela and school EB1/JI in Currais. The first one is located near the International Airport Francisco Sá Carneiro and the other school is surrounded by an electrical substation, a mechanic workshop, and by a motorway A41, both in the municipality of Maia

Impacto do ruído no processo de ensino-aprendizagem na Escola do 1º Ciclo de Ensino Básico (1ºCEB) de Prozela - Maia

Ruído de fundo excessivo, ou ainda emissões de ruído provenientes da envolvente escolar, podem traduzir-se numa barreira para a comunicação da comunidade educativa. Pretende- se com este estudo avaliar o impacto do ruído proveniente do exterior, assim como o gerado no interior dos edifícios escolares do 1º CEB e a sua influência no desempenho dos respectivos alunos. A amostra é constituída pela escola EB1/JI de Prozela, situada no concelho da Maia. As ferramentas adoptadas para desenvolver estes estudos incluem modelos de previsão de ruído numa plataforma de SIG e dois sonómetros classe 1 para as medições do nível de ruído in-situ. Posteriormente procedeu-se a uma avaliação subjectiva através da aplicação de questionários à população de alunos e professores. Esta combinação foi a base para a validação das relações estabelecidas entre os níveis de ruído existente e o impacto deste na aprendizagem

The noise impact in the learning-teaching process in an elementary school

Excessive background noise, or even noise emissions coming from the surroundings of the school environment, may become a barrier concerning communication within the school community. The aim of this study was to evaluate the impact of noise from outside, as well as the noise generated within the school building of a primary school and its influence on the performance of their students. The sample is constituted by the school EB1/JI in Prozela, an elementary school, located close the International Airport Francisco Sá Carneiro, in the municipality of Maia

Impacto do ruído na saúde e qualidade de vida das pessoas: O caso da cidade de Guimarães

O ruído é referido como um som indesejado, nomeadamente sons que causam distúrbios nas atividades diárias, como dormir, comunicar ou trabalhar. O ruído ambiental define-se como o ruído que é atribuído ao tráfego, à indústria, à vizinhança ou atividades recreativas que é sentido pelas comunidades. Nas últimas décadas, o ruído ambiental tem vindo a aumentar de forma regular e é atualmente uma importante preocupação para a sociedade. Como resposta a União Europeia adotou em 2002 uma Diretiva para avaliar e gerir o ruído ambiental nas comunidades, um problema ambiental que se tornou numa questão de saúde públic

Epidemiological factors associated with uterine fibroids

Introduction: The uterine fibroids are the most common benign neoplasm in the female genital tract. However, the prevalence of this disease in the general population is unknown, which justifies this investigation. Objective: To evaluate epidemiological factors associated with uterine myomas, in a setting of a private medical clinic. Methodology: It is presented as a cross-sectional research, drafted with a descriptive and an analytical component. To collect data a routine demographic computerized file was kept for every patient and a pelvic transvaginal or transrectal ultrasonography was performed. We retrieved from each patient their age at the time of consultation, weight, height, age of menarche, number of pregnancies, pregnancy outcome, marital status, level of education, menstrual cycle and contraceptive method used. Through the ultrasound examination, we recorded the presence of uterine myomas, their number and the largest dimension of the biggest myoma. Results: From the total women studied by ultrasonography (n = 624), uterine myomas were documented in 161 (25,8%) cases. Single myomas were presented in 49,7% (n = 80) and the majority of women had small fibroids, between 10 mm to 19 mm (41,6%, n = 67). Ages between 40 and 59 years, married marital status, overweight, menopause, previous pregnancy and delivery and complaints of menorrhagia were associated with a higher risk for uterine fibroids. The use of combined hormonal contraceptives was found to be a protective factor. Since these variables, after conducting a multivariate analysis, were all age dependent, we can suggest that aging is the only factor associated with the presence of uterine fibroids. Menorrhagia, metrorrhagia and pelvic pain were associated with a higher risk for multiple uterine fibroids. The use of combined hormonal contraceptives was associated with a higher risk for single fibroids. Ages between 40 and 59 years and a history of pregnancy and delivery were associated with a smaller dimension of the leiomyomas. Conclusion: Uterine myoma is a very common pathology among the female population. In our study, the only risk factor related with uterine fibroids was aging. Pregnacy and delivery seem to be associated with myomas of a smaller dimension. Single myoma is more common in patients using combined hormonal contraception

Professores em início de carreira : Formação inicial e saberes da experiencia

Trata de uma pesquisa que toma como eixo de reflexao a açao docente de professores de Educaçao Física em início de carreira. A investigaçao analisou as mediaçoes, tensoes e açoes pedagógicas, saber-fazer, desses professores no momento de suas aulas confrontando-os com a formaçao inicial e os saberes constituídos durante as suas trajetórias docentes, que aqui denominaremos de saberes da experiência. A pesquisa tem como objeto de estudo a formaçao inicial e a experiência docente e toma como sujeitos da pesquisa três professores com menos de cinco anos de atuaçao na educaçao básica, em escolas da cidade da Grande Vitória/ES - Brasil. Trata-se de uma pesquisa de natureza qualitativa, caracterizada como um estudo de caso do tipo etnográfico. Os instrumentos metodológicos utilizados foram: observaçoes de aulas, durante três meses, entrevistas semiestruturadas com os sujeitos da pesquisa e grupo focal. A análise contribuiu para reflexao sobre a formaçao inicial vinculada aos aspectos didático-metodológicos da experiência docente. Espera-se com este estudo contribuir com a discussao acerca da formaçao inicial de Professores Licenciados em Educaçao Físic

Industrial contribution to the air quality of one mid-sized portuguese city

Urban air pollution became one of the main factors of degradation of the quality of life in cities. This problem tends to worsen due to the unbalanced development of urban spaces and the incompatibilities of uses. In urban environment the typical anthropogenic sources are mainly the road traffic and, when existing, the industrial activity. The present work was performed to attain the following objectives: to quantify the atmospheric emissions from the major industrial sources located in the city and its vicinity and to evaluate the influence of these industrial sources to the air quality of the city. A range of numerical models were used to produce the concentration maps: the ADMS-Urban model for the pollutants dispersion; the Hills model to calculate air flow and turbulence over complex terrain and the European Pollutant Emission Register to estimate the emission factors.(undefined