Publications

Abstract Museums and exhibitions usually attempt to evaluate visitors' obtained knowledge through the use of traditional evaluation methods such as questionnaires. These are intrusive and may not provide correct results, especially due to the fact that visitors are usually not interested in being evaluated and may consider such questionnaires as intelligence tests. This paper proposes methods of design and creation of automatic evaluation techniques that make use of Virtual Reality (VR) in order to evaluate users' obtained knowledge after playing through a VR museum game experience. This Analysis System is non-intrusive (its methodology does not impact users' immersion and engagement), valid (can draw conclusions regarding users' obtained knowledge), and replicable (designed techniques can be used in a variety of experiences). Results indicate that the designed assessment techniques can be used to automatically evaluate the knowledge obtained by users throughout the experience, as well as some considerations to keep in mind when designing game experiences with these techniques.

Abstract The goal of this paper is to understand the way multimedia and virtual reality are being integrated into the communication practices of science centers and represented by their directors or responsible personnel, from the perspective of the social representations theory. Through a three-phase, mixed-methods approach, we focused on the 21 institutions of the Portuguese network of science centers (Rede de Centros Ciencia Viva). Phase I consisted of a documentary analysis of the science centers websites and Facebook pages, in order to draw a preliminary map of the activities, scientific areas, multimedia and virtual reality devices of the centers. In phase II, we surveyed 16 directors or responsible personnel of the science centers via an online questionnaire, to corroborate the results obtained in the documentary analysis and also to identify the role of multimedia in science centers and which of them had virtual reality activities. Phase III consisted of semi-structured interviews with six directors or responsible personnel of six science centers from North to South of Portugal to explore their social representations, as well as to obtain in-depth information about the role of multimedia, virtual reality and visitors in the science communication strategy of the centers. Data were analyzed with the support of Excel, SPSS, and NVivo. Results showed that exhibitions are the most common kind of activities, followed by laboratories and workshops. Physical-natural sciences were represented in more than 75% of the science centers; mathematics, robotics, and informatics were present in less than 50% of the centers; social sciences and arts were underrepresented. Whereas projection devices and computers were used in more than 80% of the centers, virtual reality devices, tablets, and touch screens were used in less than 15%. Results of phase II, besides corroborating data from phase I, showed that the integration of multimedia seems to be associated with different degrees of interactivity allowed for the visitor. Virtual reality devices were mainly used to demonstrate their immersive capability rather than to explore the specificities of the science contents. As for the social representations, we found that multimedia was associated with the integration of image and sound and anchored to learning purposes and young audiences. Virtual reality was defined as "simulation" and "reality that does not exist", therefore objectifying the concept of interactivity. It was perceived as a means to attract more audience. Though a central role was assigned to the visitor, contextualization seemed to be the more frequently adopted model of science communication. The findings suggest that, though multimedia plays a central role in the centers, it does not meet up the promise of allowing for higher levels of interactivity and public engagement and that virtual reality became the ultimate technology for making sense of interactivity and extension of reality. This study urges for a framework to promote a balanced integration of the multimedia with the activities of science centers to support the adoption of bidirectional models of science communication, in which evaluation is essential. This line of research is being explored in a science communication project (I SEA) by a multidisciplinary team. Based on the affordances and social representations of virtual reality, the main goal is to develop a non-obtrusive method of evaluation of science communication in non-formal spaces.

Abstract A series of pyridyl analogues of rosamines was prepared by employing two methodologies: (i) the conventional-heating condensation of a pyridinecarboxaldehyde with 3-(diethylamino)phenol in propionic acid, and (ii) the novel ohmic-heating assisted condensation under "on water" conditions, followed by oxidation. The 4-pyridyl substituted rosamine was further converted into the N-methylpyridinium derivative through N-alkylation using methyl iodide. The influence of the position and cationization of the nitrogen atom of the pyridyl ring in the physicochemical properties of fluorophores was investigated by H-1, C-13, N-15 NMR spectral analysis, UV/Vis and fluorescence spectroscopy, single-crystal X-ray diffraction (4-pyridyl and N-methylpyridinium derivatives) and thermal-behavior analysis. Curiously, for ethanolic solutions of 4-pyridyl and N-methylpyridinium derivatives an extinction of color and fluorescence over time was observed. This phenomenon was further studied and the data revealed that it is the result of nucleophilic addition of ethoxide ion to the central 9-position of the xanthene. The kinetics of the process is slower for the 4-pyridyl rosamine, which emphasizes the importance of the charge in the N-methylpyridinium analogue in the reactivity of the molecule towards a nucleophile agent. This phenomenon is reversible, meaning that the compounds can be rapidly recovered by decreasing the pH, opening new avenues in the sensing applications of this class of rosamines.

Abstract Self-assembled vesicles composed of amino acid-based cationic/anionic surfactant mixtures show promise as novel effective drug nanocarriers. Here, we report the in vitro performance of vesicles based on cationic (16Ser) and anionic (8-8Ser) serine-based surfactants using a cancer cell model for the delivery of the anticancer drug doxorubicin (DOX). This catanionic mixture yields both negatively (0.20 in the cationic surfactant molar fraction, x(16Ser)) and positively (x(16Ser) '= 0.58) charged vesicles, hence providing a surface charge tunable system. Low toxicity is confirmed for concentration ranges below 32 mu M in both formulations. DOX is successfully encapsulated in the vesicles, resulting in a surface charge switch to negative for the (0.58) system, making both (0.20) and (0.58) DOX-loaded vesicles highly interesting for systemic administration. High uptake by cells was demonstrated using flow cytometry and confocal microscopy. Drug accumulation results in an increase of cell uptake up to 250% and 200% for the (0.20) and (0.58) vesicles, respectively, compared to free DOX and with localizations near the nuclear regions in the cells. The in vitro cytotoxicity studies show that DOX-loaded vesicles induce cell death, confirming the therapeutic potential of the formulations. Furthermore, the efficient accumulation of the drug inside the cell compartments harbors the potential for optimization strategies including phased delivery for prolonged treatment periods or even on-demand release.

Abstract In this study we focused on the social representations of digital teaching among Higher Education agents, considering their reported experience (more or less diversified) and type of access (mobile devices or not, large-screen devices or small screen-devices). The context of the study was a public Higher Education institution in the North of Portugal in which the Moodle was adopted years ago to support learning activities. The participants were 36 teachers (39% males, 61% females), aged between 25 and 55 years old, and 144 freshmen students (19% males, 81% females), aged between 18 and 57 years old, enrolled in different programs in the area of Health care. They answered to a questionnaire that consisted of: free association tasks around stimuli such as digital teaching and Moodle; a semantic differentiation scale on the attitudes towards Moodle; multiple choice questions about the levels of use and type of access to the platform; and demographic questions, including age and sex. A content-analysis of the qualitative data was conducted, using a macro developed in Excel. Words evoked by the participants were reduced to their most common form and phases rewritten to their common theme. Words and themes were then grouped under overarching categories. A descriptive analysis of the quantitative data was also performed. Results revealed that whereas for the teachers the semantic field of digital teaching consisted of the categories accessibility (47%), evolution (42%), and distance (39%); for the students it consisted of technology (97%), evolution (59%), and easiness (37%). The Moodle was seen as a kind of repository by the majority of the students (89%). Such an image is shared by less than one-half of teachers (36%), and it was more common among those who declared to use more functionalities of the learning management system (LMS). It is worth mentioning that almost one-half of students associated the Moodle with knowledge (49%). Errors and the dependency on the Internet were pointed out as the main constraints of the LMS, while accessibility and easiness of use were the main advantages. Concerning access, the portable computer was the device most used by both teachers and students (90%). Desktops were used by more than 80% of teachers and by less than 20% of students, while the reverse picture was found in the access by mobile phone (around 20% of teachers and around 70% of students). This study provides clues about the relation among the social position of the agents, their practices and their representations. The social representations seem to be more homogeneous among students than among teachers, suggesting that there is a relation with practices. The fact that the image of the Moodle as a repository is more present among the teachers who reported having used more functionalities of the Moodle is somewhat counter-intuitive and urges for more studies. It is also very suggestive that the agents use different anchors to represent digital teaching: distance in the case of the teachers and technology in the case of the students, though they converge in seeing it as a sign of evolution. Although mobile access seems to be more frequent among students, big screen devices are more used than small screen devices. These results do not support the idea of a screen-device gap among the participants, but should nevertheless open a discussion about what kind of affordances are being explored in digital teaching.

Abstract Stimuli-sensitive self-assembled nanostructures are of great relevance for the templating of nanomaterials and the design of efficient systems for the controlled delivery of molecules. Amino acid-based surfactants often display such fascinating self-assembly due to a combination of molecular features such as critical packing parameter, chirality and H-bonding interactions. Herein, we focus on a family of newly synthesized double-chained alkylcarboxylates derived from L-lysine, and designated by 8Lysn, mLys8, with n, m = 12, 14 and 16, and 12Lys16 and 16Lys12, where the numbers represent the number of C atoms in each hydrocarbon chain. The effects of the chain length asymmetry and structural isomerism of the surfactants on their interfacial properties, thermal behavior and self-assembly in water were investigated by a comprehensive toolbox, including surface tension, DSC, imaging (light microscopy, SEM, TEM and AFM) and SAXS. All the surfactants below their Krafft temperature self-organize into tubular structures of various morphologies (flat structures, twisted and coiled ribbons and hollow tubes), forming hydrogels at low surfactant concentration. Upon the solubilization phase transition, micelles or vesicles are formed depending on the surfactant structure, and the tubule-micelle or tubule-vesicle transition is thermoreversible. A molecular-level rationalization of the observed self-assembly and phase transition features is put forth.

Abstract A library of 4-[(3-methyl-4-aryl-2,3-dihydro-1,3-thiazol-2-ylidene)amino]benzene-1-sulphonamides (EMAC8002a–m) was designed and synthesised to evaluate the effect of substituents in the positions 3 and 4 of the dihydrothiazole ring on the inhibitory potency and selectivity toward human carbonic anhydrase isoforms I, II, IX, and XII. Most of the new compounds preferentially inhibit the isoforms II and XII. Both electronic and steric features on the aryl substituent in the position 4 of the dihydrothiazole ring concur to determine the overall biological activity of these new derivatives.

Abstract An experimental study of the vapour pressures and related thermodynamic properties of three phenyl derivatives of maleic anhydride and oxazole is reported. The vapour pressures of the crystalline phase of these compounds were measured at different temperatures using the Knudsen mass-loss effusion method, enabling the determination of the standard (p degrees = 0.1 MPa) molar enthalpies, entropies and Gibbs energies of sublimation. The enthalpies and temperatures of fusion were determined from DSC experiments. Quantum chemical calculations were used to calculate gas-phase isobaric heat capacities and absolute entropies. (C) 2018 Elsevier Ltd.