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Moreira P.S.,University of Minho | Moreira P.S.,Pt Government Ass Laboratory | Moreira P.S.,Clinical Academic Center Braga | Almeida P.R.,University of Porto | And 8 more authors.
PLoS ONE | Year: 2016

The idea that maladaptive stress impairs cognitive function has been a cornerstone of decades in basic and clinical research. However, disparate findings have reinforced the need to aggregate results from multiple sources in order to confirm the validity of such statement. In this work, a systematic review and meta-analyses were performed to aggregate results from rodent studies investigating the impact of chronic stress on learning and memory. Results obtained from the included studies revealed a significant effect of stress on global cognitive performance. In addition, stressed rodents presented worse consolidation of learned memories, although no significantly differences between groups at the acquisition phase were found. Despite the methodological heterogeneity across studies, these effects were independent of the type of stress, animals' strains or age. However, our findings suggest that stress yields a more detrimental effect on spatial navigation tests' performance. Surprisingly, the vast majority of the selected studies in this field did not report appropriate statistics and were excluded from the quantitative analysis. We have therefore purposed a set of guidelines termed PROBE (Preferred Reporting Orientations for Behavioral Experiments) to promote an adequate reporting of behavioral experiments. © 2016 Moreira et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

Pandis C.,National Technical University of Athens | Pandis C.,Polytechnic University of Valencia | Madeira S.,European Institute of Excellence on Tissue Engineering and Regenerative Medicine | Matos J.,European Institute of Excellence on Tissue Engineering and Regenerative Medicine | And 5 more authors.
Materials Science and Engineering C | Year: 2014

Chitosan-silica porous hybrids were prepared by a novel strategy in order to improve the mechanical properties of chitosan (CHT) in the hydrogel state. The inorganic silica phase was introduced by sol-gel reactions in acidic medium inside the pores of already prepared porous scaffolds. In order to make the scaffolds insoluble in acidic media chitosan was cross-linked by genipin (GEN) with an optimum GEN concentration of 3.2 wt.%. Sol-gel reactions took place with Tetraethylorthosilicate (TEOS) and 3-glycidoxypropyltrimethoxysilane (GPTMS) acting as silica precursors. GPTMS served also as a coupling agent between the free amino groups of chitosan and the silica network. The morphology study of the composite revealed that the silica phase appears as a layer covering the chitosan membrane pore walls. The mechanical properties of the hybrids were characterized by means of compressive stress-strain measurements. By immersion in water the hybrids exhibit an increase in elastic modulus up to two orders of magnitude. © 2014 Elsevier B.V.

Srisuk P.,European Institute of Excellence on Tissue Engineering and Regenerative Medicine | Srisuk P.,Pt Government Ass Laboratory | Srisuk P.,Khon Kaen University | Correlo V.M.,European Institute of Excellence on Tissue Engineering and Regenerative Medicine | And 7 more authors.
Natural Product Research | Year: 2016

The redox properties of natural extract from cuttlefish ink sac (Sepia officinalis) and synthetic melanin used as a biomimetic in melanin structural investigation were determined by comparison of this phenol-based heterogeneous pigment with gallic acid used as a standard in Folin-Ciocalteu colorimetric assay widely employed for characterisation of oxidative properties of biomaterials. Reactivity of sepia melanin reported here is much higher than previously indicated and this protocol should allow the redox characterisation of all melanins irrespective of their origin and composition. © 2015 Taylor & Francis.

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