Observational Constraints on Silent Quartessence

We derive new constraints set by SNIa experiments (`gold' data sample of Riess et al.), X-ray galaxy cluster data (Allen et al. Chandra measurements of the X-ray gas mass fraction in 26 clusters), large scale structure (Sloan Digital Sky Survey spectrum) and cosmic microwave background (WMAP) on the quartessence Chaplygin model. We consider both adiabatic perturbations and intrinsic non-adiabatic perturbations such that the effective sound speed vanishes (Silent Chaplygin). We show that for the adiabatic case, only models with equation of state parameter $|\alpha |\lesssim 10^{-2}$ are allowed: this means that the allowed models are very close to \LambdaCDM. In the Silent case, however, the results are consistent with observations in a much broader range, -0.3<\alpha<0.7.Comment: 7 pages, 12 figures, to be submitted to JCA

Extracellular matrix mimics using hyaluronan-based biomaterials

Hyaluronan (HA) is a critical element of the extracellular matrix (ECM). The regulated synthesis and degradation of HA modulates the ECM chemical and physical properties that, in turn, influence cellular behavior. HA triggers signaling pathways associated with the adhesion, proliferation, migration, and differentiation of cells, mediated by its interaction with specific cellular receptors or by tuning the mechanical properties of the ECM. This review summarizes the recent advances on strategies used to mimic the HA present in the ECM to study healthy or pathological cellular behavior. This includes the development of HA-based 2D and 3D in vitro tissue models for the seeding and encapsulation of cells, respectively, and HA particles as carriers for the targeted delivery of therapeutic agents.The authors acknowledge thefinancial support from the European Commission’s H2020 programme, under grantagreements H2020-WIDESPREAD-2014-668983-FORECAST, and H2020-MSCA-RISE-2019-872648-MEPHOS. S.A.acknowledges the Portuguese Foundation for Science and Technology (FCT) for her PhD grant (SFRH/BD/112075/2015)

Encapsulation of alpha-amylase into starch-based biomaterials : an enzymatic approach to tailor their degradation rate

This paper reports the effect of a-amylase encapsulation on the degradation rate of a starch-based biomaterial. The encapsulation method consisted in mixing a thermostable a-amylase with a blend of corn starch and polycaprolactone (SPCL), which were processed by compression moulding to produce circular disks. The presence of water was avoided to keep the water activity low and consequently to minimize the enzyme activity during the encapsulation process. No degradation of the starch matrix occurred during processing and storage (the encapsulated enzyme remained inactive due to the absence of water), since no significant amount of reducing sugars was detected in solution. After the encapsulation process, the released enzyme activity from the SPCL disks after 28 days was found to be 40% comparatively to the free enzyme (unprocessed). Degradation studies on SPCL disks, with a-amylase encapsulated or free in solution, showed no significant differences on the degradation behaviour between both conditions. This indicates that a-amylase enzyme was successfully encapsulated with almost full retention of its enzymatic activity and the encapsulation of a-amylase clearly accelerates the degradation rate of the SPCL disks, when compared with the enzyme-free disks. The results obtained in this work show that degradation kinetics of the starch polymer can be controlled by the amount of encapsulated a-amylase into the matrix.This work was partially supported by Portuguese Foundation for Science and Technology (FCT) through funds from the POCTI and/or FEDER Programmes. This work was carried out under the scope of the European NoE EXPERTISSUES (NMP3-CT-2004-500283)

Wetspun poly-L-(lactic acid)-borosilicate bioactive glass scaffolds for guided bone regeneration

We developed a porous poly-L-lactic acid (PLLA) scaffold compounded with borosilicate bioactive glasses (BBGs) endowing it with bioactive properties. Porous PLLA-BBG fibre mesh scaffolds were successfully prepared by the combination of wet spinning and fibre bonding techniques. Micro-computed tomography (μCT) confirmed that the PLLA-BBG scaffolds containing ≈ 25% of BBGs (w/w) exhibited randomly interconnected porous (58 to 62% of interconnectivity and 53 to 67% of porosity) with mean pore diameters higher that 100 μm. Bioactivity and degradation studies were performed by immersing the scaffolds in simulated body fluid (SBF) and ultrapure water, respectively. The PLLA-BBG scaffolds presented a faster degradation rate with a constant release of inorganic species, which are capable to produce calcium phosphate structures at the surface of the material after 7 days of immersion in SBF (Ca/P ratio of ~ 1.7). Cellular in vitro studies with human osteosarcoma cell line (Saos-2) and human adipose-derived stem cells (hASCs) showed that PLLA-BBGs are not cytotoxic to cells, while demonstrating their capacity to promote cell adhesion and proliferation. Overall, we showed that the proposed scaffolds present a tailored kinetics on the release of inorganic species and controlled biological response under conditions that mimic the bone physiological environment.JSF acknowledges the Portuguese Foundation for Science and Technology (FCT) for his PhD grant BD/73162/2010. This work was partially supported by the European Research Council grant agreement ERC-2012-ADG20120216-321266 - project ComplexiTE

Study on the perception of DIY in domotics in Portugal

The growth of the home automation market depends on technological innovations, rapid evolution of the Internet of Things and Do-It-Yourself (DIY) solutions. This project analysed the perception about domotics related to DIY in Portugal, intending to understand if smart home technologies are used and valued, which factors motivate their acquisition, their purpose and the advantages perceived by users. A questionnaire was used to collect data, resulting in an exploratory study based on data from a convenience sample. The model to evaluate this study was based on the constructs based on Technology Acceptance Models - TAM. From the results obtained, it was concluded that the respondents have a positive perception about domotics and its usefulness faced with DIY on the technologies that make a smart home. Regarding the acquisition and installation of technologies associated with home automation on their own, the respondents are divided, as half consider that they can do it autonomously and the other half only with the intervention of specialists in home automation