Introduction: The aim of the study is to assess the prevalence of anxiety and depressive symptoms in Portuguese medical students compared to students of other faculties, and the possible impact those symptoms have on academic performance.Material and Methods: A cross-sectional study was conducted in a sample of 750 students: 512 medical students and 238 nonmedical students. All students anonymously completed a socio-demographic survey and the Hospital Anxiety and Depression Scale (HADS). Statistical analysis was performed using the chi-square test, Mann-Whitney test, Spearman correlation coefficient or Kruskal-Wallis test.Results: We found a prevalence of 21.5% (n = 161) for anxiety symptoms and 3.7% (n = 28) for depressive symptoms. Being a medical student was more significantly associated with symptoms of anxiety (p = 0.034) compared with other students. Depressive symptoms were slightly associated with poor academic performance (p < 0.01). A percentage of 59.6% (n = 96) of students with anxiety symptoms and 46.4% (n = 13) of students with depressive symptoms did not seek medical or psychological care at that time.Discussion: Medical students in this sample seem to have more symptoms of anxiety, possibly explained by a higher number of female students in that sample. Depressive symptoms could be associated with poor academic performance in both groups, but an evident correlation was not established.Conclusion: Considering the high levels of anxiety symptoms, the possible impact of depressive symptoms in academic performance and the lack of psychiatric or psychological follow-up reported in this study, it is urgent to develop adequate means of support to improve students’ well-being and mental health.
This paper presents a literature review and results of an experimental study about the effects of thermal cycles on the physical and mechanical properties of pultruded glass fibre reinforced polymer (GFRP) profiles used in civil engineering structural applications. The GFRP profiles used in this study present similar fibre architecture, differing only in their matrix nature: unsaturated polyester and vinylester. Small-scale coupons obtained from both types of GFRP profiles were exposed to a Mediterranean range of thermal variations (À5°C to 40°C) for up to 190 cycles in a dry condition. The effects of such exposure on the physical and mechanical response of the GFRP materials were assessed and compared using the following experimental techniques: (a) dynamic mechanical analyses (DMA) to assess the viscoelastic behaviour; (b) tensile, flexural and interlaminar shear tests, to evaluate the mechanical properties; and (c) scanning electron microscopy (SEM), to monitor the potential changes in the microstructure due to the degradation (if any) caused by the thermal cycles, as well as the possible changes into the main mechanisms of fracture. After exposure to thermal cycles, the viscoelastic behaviour of the GFRP profiles presented only slight changes, indicating no significant degradation, neither in the matrix structure nor at the fibre-matrix interphase. In terms of mechanical properties, both types of GFRP materials suffered slight changes regarding tensile and interlaminar shear properties. Flexural properties were more affected, particularly the flexural modulus, especially in the first cycles, as degradation tended to stabilize for increasing cycles. The GFRP profile made of vinylester resin presented better overall performance than the one made of polyester, especially regarding the tensile properties. SEM observations of the surfaces of fracture of mechanically tested pultruded specimens showed two main mechanisms of crack propagation: cohesive rupture (matrix cracking), where the crack propagates inside the matrix, and adhesive rupture (fibre-matrix debonding), where the crack propagates at the interface fibre-matrix. Degradation of the polyester matrix caused by the thermal cycles is evidenced by extensive matrix microcracking and increased fibre-matrix debonding. The vinylester matrix resists better to such degradation as fibre-matrix debonding occurs in less extent, and matrix microcracking is scarcely present.
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