Publications

Abstract Background. No Man's Sky (NMS) is a sci-fi videogame about survival and exploration where players fly spaceships, search for elements, and use them to build, trade, and survive. Despite evolving around scientific concepts, NMS isn't a serious game, and not all the scientific content in the game is presented with evidence.Theory and Method. Looking at the interceptions between videogames and science, and moving to how science communication, both in theory and practice, can be explored within the videogame's paradigm, a survey was developed to better understand how NMS players perceive the scientific content in the game.Aims. Are players aware of the scientific content and how it is presented in NMS? Can they decipher it, question it and understand it under real-world rules? With the data collected from 124 respondents from 23 countries, we aim to better understand how an entertainment videogame can potentially help scientists, educators, and science communicators reach a growing, evolving, vibrant, diverse, and demanding audience.Results. Players seem aware of the scientific content in NMS, with a positive attitude through it. But players showed problems identifying what is right and wrong, while also pointing to the idea that every videogame that deals with science should strive to treat it with evidence. 57% of the respondents answered that NMS motivated them to know more about chemistry, with more than 35% revealing that they learned something new and understood the role of some scientific fundaments in certain real-world situations like new energy sources, biomes, or the role of carbon and oxygen.Discussion and Conclusion. With the growth of the videogames' audience, educators, science communicators, scientists, and policymakers can find in the medium - in any shape or form - a fun and interactive ally to engage with younger audiences and promote dialogues that can be transformative around scientific topics.

Abstract Science communication is an essential activity for institutions and scientists seeking to reach out to the public, find funding opportunities or career advancement. In this article, we intend to better present the reality of science communication practices in Portuguese research units. A questionnaire was drawn up and data from 124 centers were analyzed. Traditional strategies such as public events, science fairs or open days continue to be strong allies to the Portuguese scientific community, as does direct communication with journalists. But social media platforms, used by 109 of 124 respondents, are becoming fundamental. The Portuguese scientific community is experimenting with videos, animations, applications, or podcasts, suggesting that practice in science communication is becoming more demanding, specialized, and focused on finding multiple ways to reach the community.

Abstract Mixtures of cationic and anionic surfactants often originate bilayer structures, such as vesicles and lamellar liquid crystals, that can be explored as model membranes for fundamental studies or as drug and gene nanocarriers. Here, we investigated the aggregation properties of two catanionic mixtures containing biomimetic surfactants derived from serine. The mixtures are designated as 12Ser/8-8Ser and 14Ser/10-10Ser, where mSer is a cationic, single-chained surfactant and n-nSer is an anionic, double-chained one (m and n being the C atoms in the alkyl chains). Our goal was to investigate the effects of total chain length and chain length asymmetry of the catanionic pair on the formation of catanionic vesicles, the vesicle properties and the vesicle/micelle transitions. Ocular observations, surface tension measurements, video-enhanced light microscopy, cryogenic scanning electron microscopy, dynamic and electrophoretic light scattering were used to monitor the self-assembly process and the aggregate properties. Catanionic vesicles were indeed found in both systems for molar fractions of cationic surfactant >= 0.40, always possessing positive zeta potentials (zeta = +35-50 mV), even for equimolar sample compositions. Furthermore, the 14Ser/10-10Ser vesicles were only found as single aggregates (i.e., without coexisting micelles) in a very narrow compositional range and as a bimodal population (average diameters of 80 and 300 nm). In contrast, the 12Ser/8-8Ser vesicles were found for a wider sample compositional range and as unimodal or bimodal populations, depending on the mixing ratio. The aggregate size, pH and zeta potential of the mixtures were further investigated. The unimodal 12Ser/8-8Ser vesicles (<D-H> approximate to 250 nm, pH approximate to 7-8, zeta approximate to +32 mV and a cationic/anionic molar ratio of approximate to 2:1) are particularly promising for application as drug/gene nanocarriers. Both chain length asymmetry and total length play a key role in the aggregation features of the two systems. Molecular insights are provided by the main findings.

Abstract Interactions between polymers (P) and surfactants (S) in aqueous solution lead to interfacial and aggregation phenomena that are not only of great interest in physical chemistry but also important for many industrial applications, such as the development of detergents and fabric softeners. Here, we synthesized two ionic derivatives-sodium carboxymethylcellulose (NaCMC) and quaternized cellulose (QC)-from cellulose recycled from textile wastes and then explored the interactions of these polymers with assorted surfactants-cationic (CTAB, gemini), anionic (SDS, SDBS) and nonionic (TX-100)-commonly used in the textile industry. We obtained surface tension curves of the P/S mixtures by fixing the polymer concentration and then increasing the surfactant concentration. In mixtures where polymer and surfactant are oppositely charged (P-/S+ and P+/S-), a strong association is observed, and from the surface tension curves, we determined the critical aggregation concentration (cac) and critical micelle concentration in the presence of polymer (cmc(p)). For mixtures of similar charge (P+/S+ and P-/S-), virtually no interactions are observed, with the notable exception of the QC/CTAB system, which is much more surface active than the neat CTAB. We further investigated the effect of oppositely charged P/S mixtures on hydrophilicity by measuring the contact angles of aqueous droplets on a hydrophobic textile substrate. Significantly, both P-/S+ and P+/S- systems greatly enhance the hydrophilicity of the substrate at much lower surfactant concentrations than the surfactant alone (in particular in the QC/SDBS and QC/SDS systems).

Abstract Spatially and temporally localized delivery is a promising strategy to circumvent adverse effects of traditional drug therapy such as drug toxicity and prolonged treatments. Stimuli-responsive colloidal nanocarriers can be crucial to attain such goals. Here, we develop a delivery system based on dual light and pH responsive vesicles having a cationic bis-quat gemini surfactant, 12-2-12, and a negatively charged amphiphilic chalcone, C4SCh. The premise is to exploit the chalcone/flavylium interconversion to elicit a morphological change of the vesicles leading to the controlled release of an encapsulated drug. First, the phase behavior of the catanionic system is studied and the desirable composition yielding stable unilamellar vesicles identified and selected for further studies. The solutions containing vesicles (Dh & AP;200 nm, & zeta;-potential & AP;80 mV) are in-depth characterized by light microscopy, cryo-transmission electron microscopy (cryo-TEM), dynamic light scattering (DLS) and surface tension measurements. Upon subjecting the vesicles to UV irradiation (& lambda; = 365 nm) at near neutral pH (& AP; 6.0), no morphological effects are observed, yet when irradiation is coupled with pH = 3.0, the majority of the vesicles are disrupted into bilayer fragments. The anticancer drug doxorubicin (DOX) is successfully entrapped in the non-irradiated vesicles, yielding an encapsulation efficiency of & AP;25% and a loading capacity of & AP;3%. The release profile of the drug-loaded vesicles is then studied in vitro in four conditions: i) no stimuli (pH = 6.0); ii) irradiation, pH = 6.0; iii) no irradiation and adjusted pH = 3.0; iv) irradiation and adjusted pH = 3.0 Crucially, irradiation at pH = 3.0 leads to a sustained release of DOX to ca. 80% (within 4 h), whereas cases i) and ii) lead to only & AP;25 % release and case iii) to 50% release but precipitation of the vesicles. Thus, our initial hypothesis is confirmed: we present a proof of concept delivery system where light and pH act as inputs of an AND logic gate mechanism for the controlled release of a relevant biomedical drug (output). This may prove useful if the irradiated nanocarriers meet acidified physiological environments such as tumors sites, endosomes or lysosomes.

Abstract The textile industry has a strong interest in superhydrophobicity and water repellence and, in particular, in the development of waterproof, self-cleaning and stain-resistant clothing and other textile products. In this study, to promote hydrophobicity in textiles, novel fluorine-free formulations were developed based on long-chain cellulose esters (LCCEs), synthesized from recycled cellulose in a heterogeneous system. The synthesized LCCEs (with alkyl side chains containing 6 to 18 carbon atoms, C6-C18) were characterized by spectroscopic (nuclear magnetic resonance and Fourier-transform infrared spectroscopy) and thermal (thermogravimetry analysis and differential scanning calorimetry) methods in order to validate their synthesis and intrinsic characteristics. The recycled cellulose was obtained from textile residues, in a circular approach toward textile functionalization. The developed formulations contain regular dry-cleaning solvents. Because of their nontoxicity, and ease of application by conventional drycleaning methods, these LCCEs provide a simple, eco-friendly, sustainable and effective alternative to the compounds currently used for promoting water repellency in textiles. The fabrics treated with the LCCE-based formulations were evaluated for static and dynamic contact angles, surface energy, wettability, water vapor permeability and cytotoxicity. The resistance of the treatment to domestic washing and thermal treatment was also assessed.

Abstract Long-chain cellulose esters (LCCEs) are recently developed cellulose derivatives showing properties that are relevant to diverse applications, such as coatings, films and plastics. The nonpolar aliphatic tails of the fatty ester groups impart strong hydrophobic properties to LCCEs, the physicochemical basis for most of the proposed uses. In previous work, we developed LCCE-based formulations as hydrophobicity-promoting agents for pure cotton textiles. Herein, we aimed to expand the use of LCCEs as eco-friendly hydrophobic additives in textiles with different compositions, namely synthetic fibers and mixtures thereof. The LCCE-based formulations were applied by a conventional textile dry-cleaning industrial process, using three types of solvents (one conventional and two green alternative ones). We observed that even for synthetic fibers or blends, there was no need to use crosslinkers to anchor LCCEs to textiles, nor need for pre-treatments to promote an increase in hydrophobic capacity. Water-repellent textiles were thus obtained through sustainable flourine-free compounds, with easy and self-cleaning properties.

Abstract (1) Background: Superficial, including cutaneous and mucocutaneous infections are a current public health problem with universal distribution. One of the main concerns, in the present/future, is fungal/bacterial infections by resistant microorganisms. This study aimed to verify if decoctions of coptidis (Coptis chinensis, Ranunculaceae family), neem (Azadirachta indica, Meliaceae family), and their essential oils (EOs), as well as the EO of manuka (Leptospermum scoparium, Myrtaceae family) have antimicrobial activity against prevalent species of microorganisms responsible for superficial infections. (2) Methods: The antimicrobial activity was determined by the minimum inhibitory concentration (MIC), using broth microdilution method, and minimum lethal concentration (MLC) was determined from subculture of MIC plates. (3) Results: C. chinensis EO and decoction demonstrated some antifungal action against the yeasts and dermatophytes tested. Greatest bactericidal effect against Propionibacterium acnes and some action against Staphylococcus aureus was observed. For A. indica only EO proved activity against dermatophytes and P. acnes. L. scoparium EO showed the broadest antimicrobial spectrum with activity against bacteria, yeasts, and dermatophytes showing greater activity against P. acnes and S. aureus. (4) Conclusions: C. chinensis (EO/decoction), EOs of L. scoparium and A. indica proved in vitro efficacy against fungal, bacterial, or mixed agents of superficial infections, either by sensitive or resistant strains.

Abstract The purpose of this work was to investigate, for the first time to our knowledge, the chemical composition and bioactivity of methanolic extracts (roots, stems, leaves, and flowers) from Cladanthus mixtus (L.) Chevall. that grows wild in northern Morocco (the Tangier-Tetouan-Al Hoceima region). The phenolic and flavonoid contents were determined by spectrophotometer methods, and the composition of derivatized methanolic extracts from C. mixtus using N-O-bis(trimethylsilyl) trifluoroacetamide (BSTFA) was analyzed by gas chromatography-mass spectrometry (GC-MS). The antioxidant activity was carried out by applying the 2,2 '-azino-bis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) and DPPH (2,2-diphenyl-1-picrylhydrazyl) tests. The micro-dilution technique was chosen to investigate the antimicrobial activity of methanolic extracts against two bacterial strains and three fungal species. The results showed that the values of total phenolic and flavonoid contents were found to be higher in flower extracts (30.55 +/- 0.85 mg of gallic acid equivalents (GAE)/g of dried weight (DW) and 26.00 +/- 1.34 mg of quercetin equivalents (QE)/g DW, respectively). Other groups of chemical compounds were revealed by GC-MS, such as carbohydrates (27.25-64.87%), fatty acids (1.58-9.08%), organic acids (11.81-18.82%), and amino acids (1.26-7.10%). Root and flower methanolic extracts showed the highest antioxidant activity using ABTS (39.49 mg of Trolox equivalents (TE)/g DW) and DPPH (36.23 mg TE/g DW), respectively. A positive correlation between antioxidant activity and polyphenol and flavonoid amounts was found. Antibacterial tests showed that the best activity was presented by the leaf extract against Staphylococcus aureus (minimum inhibitory concentration (MIC) = minimum bactericidal concentration (MBC) = 20 mg/mL) and Escherichia coli (MIC of 30 mg/mL and MBC of 35 mg/mL). S. aureus was more sensitive to the extracts compared to E. coli. All extracts showed antifungal activity against Trichophyton rubrum, with the best efficacy reported by the flower and leaf extracts (MIC = 1.25 mg/mL and minimum fungicidal concentration (MFC) = 2.5 mg/mL). In general, extracts of C. mixtus appeared less effective against Candida albicans and Aspergillus fumigatus.