2024
Authors
Medeiros-Fonseca, B; Faustino-Rocha, AI; Pires, MJ; Neuparth, MJ; Vala, H; Vasconcelos-Nóbrega, C; Gouvinhas, I; Barros, AN; Dias, MI; Barros, L; Bastos, MMSM; Gonçalves, L; Félix, L; Venancio, C; Medeiros, R; Costa, RMGD; Oliveira, PA;
Publication
VETERINARY WORLD
Abstract
Background and Aim: Papillomaviruses (PVs) infections have been documented in numerous animal species across different regions worldwide. They often exert significant impacts on animal health and livestock production. Scientists have studied natural products for over half a century due to their diverse chemical composition, acknowledging their value in fighting cancer. Acorns (Quercus ilex) are believed to have several unexplored pharmacological properties. This study aimed to evaluate the in vivo safety and cancer chemopreventive activity of an infusion extract of Q. ilex in a transgenic mouse model of human PV (HPV)-16, which developed squamous cell carcinomas through a multistep process driven by HPV16 oncogenes. Materials and Methods: Q. ilex extract was prepared by heating in water at 90 degrees C and then characterized by mass spectrometry. Phenolic compounds from this extract were administered in drinking water to female mice in three different concentrations (0.03, 0.06, and 0.09 g/mL) over a period of 28 consecutive days. Six groups (n = 6) were formed for this study: group 1 (G1, wildtype [WT], water), group 2 (G2, HPV, water), group 3 (G3, WT, 0.09 g/mL), group 4 (G4, HPV, 0.03 g/mL), group 5 (G5, HPV, 0.06 g/ mL), and group 6 (G6, HPV, 0.09 g/mL). Throughout the experiment, humane endpoints, body weight, food intake, and water consumption were recorded weekly. Following the experimental period, all mice were sacrificed, and blood, internal organs, and skin samples were collected. Blood was used to measure glucose and microhematocrit and later biochemical parameters, such as creatinine, urea, albumin, alanine aminotransferase, and total proteins. Histological analysis was performed on skin and organ samples. Results: The administration of Q. ilex extract resulted in a statistically significant increase in relative organ weight among HPV transgenic animals, indicating adaptive biological response to the tested concentrations. Moreover, a reduction in characteristic skin lesions was observed in animals treated with the 0.06 and 0.09 g/mL extract. Conclusion: These results provide a favorable chemopreventive profile for Q. ilex extract at concentrations of 0.06 and 0.09 g/mL. This study highlights the potential of Q. ilex extract as a safe and effective therapeutic strategy against HPV16associated lesions in transgenic mouse models. The limitation of our study was the durability of transgenic animals. As a more sensitive species, we must always be careful with the durability of the test. We intend to study concentrations of 0.06 and 0.09 g/mL for longer to further investigate their possible effects.
2024
Authors
Guedes, JG; Ribeiro, R; Carqueijeiro, I; Guimaraes, AL; Bispo, C; Archer, J; Azevedo, H; Fonseca, NA; Sottomayor, M;
Publication
JOURNAL OF EXPERIMENTAL BOTANY
Abstract
Catharanthus roseus leaves produce a range of monoterpenoid indole alkaloids (MIAs) that include low levels of the anticancer drugs vinblastine and vincristine. The MIA pathway displays a complex architecture spanning different subcellular and cell type localizations, and is under complex regulation. As a result, the development of strategies to increase the levels of the anticancer MIAs has remained elusive. The pathway involves mesophyll specialized idioblasts where the late unsolved biosynthetic steps are thought to occur. Here, protoplasts of C. roseus leaf idioblasts were isolated by fluorescence-activated cell sorting, and their differential alkaloid and transcriptomic profiles were characterized. This involved the assembly of an improved C. roseus transcriptome from short- and long-read data, IDIO+. It was observed that C. roseus mesophyll idioblasts possess a distinctive transcriptomic profile associated with protection against biotic and abiotic stresses, and indicative that this cell type is a carbon sink, in contrast to surrounding mesophyll cells. Moreover, it is shown that idioblasts are a hotspot of alkaloid accumulation, suggesting that their transcriptome may hold the key to the in-depth understanding of the MIA pathway and the success of strategies leading to higher levels of the anticancer drugs. Catharanthus mesophyll idioblasts are a hotspot of alkaloid accumulation. The idioblast transcriptome is associated with stress responses and provides a roadmap towards the increase of anticancer alkaloid levels.
2024
Authors
Dudkina E.; Villar J.; Bessa R.J.; Crisostomi E.;
Publication
4th International Conference on Smart Grid and Renewable Energy, SGRE 2024 - Proceedings
Abstract
Hydrogen is currently getting more and more attention in the European climate strategy as a promising enabling technology to decarbonize industry, transport sector and to provide a long-term, high-capacity energy storage solution. However, to truly contribute to the reduction of CO2 emissions, hydrogen must be produced respecting a principle of additionality, to ensure that it is produced using renewable energy sources and that its production does not decrease the green energy supplied to other loads. This study tracks the share of renewables generation in the energy mix used to produce hydrogen by applying a power flow tracing technique integrated with an optimal power flow analysis. This method allows the minimization of the system operation costs, while maximizing the green hydrogen production and considering the additionality principle. The system cost function is also modified to include the sizing and allocation of conventional batteries in the grid, and assess their ability to further increase the share of green energy in hydrogen production.
2024
Authors
Pereira M.; Silva J.C.; Pinheiro M.; Carvalho S.; Santos G.;
Publication
Internet of Things and Cyber-Physical Systems
Abstract
Barcelos is a historic city in Portugal with many tourist attractions, attracting more and more visitors who come to the city with the aim of exploring it. The main objective of this article is to boost tourism in the city of Barcelos, specifically highlighting tourist, historical and leisure spots, based on the development of a mobile application using augmented reality technologies and geolocation. This application intends to allow the users to know historical points of interest in Barcelos, as well as interact with a certain point. The results of this investigation were evaluated by testing the application by end users, with the aim of identifying whether the application meets their needs, in particular the promotion of tourist and historical points.
2024
Authors
de Oliveira, M; Barbosa, LS; Galvao, EF;
Publication
QUANTUM
Abstract
Several classes of quantum circuits have been shown to provide a quantum computational advantage under certain assumptions. The study of ever more restricted classes of quantum circuits capable of quantum advantage is motivated by possible simplifications in experimental demonstrations. In this paper we study the efficiency of measurement-based quantum computation with a completely flat temporal ordering of measurements. We propose new constructions for the deterministic computation of arbitrary Boolean functions, drawing on correlations present in multi-qubit Greenberger, Horne, and Zeilinger (GHZ) states. We characterize the necessary measurement complexity using the Clifford hierarchy, and also generally decrease the number of qubits needed with respect to previous constructions. In particular, we identify a family of Boolean functions for which deterministic evaluation using non-adaptive MBQC is possible, featuring quantum advantage in width and number of gates with respect to classical circuits.
2024
Authors
Sousa, N; Jorge, F; Teixeira, MS; Losada, N; Alen, E; Guttentag, D;
Publication
INTERNATIONAL JOURNAL OF TOURISM RESEARCH
Abstract
Immersive experiences offered by virtual reality (VR) have the power to impact tourists' decision-making and on-site experiences. However, prior research has focused on explaining VR's acceptance by tourists as a function of technological capacity, rather than user characteristics, such as innovativeness. This research intends to fill the existing knowledge gap regarding the role of technological innovativeness on VR experiences. To do so, this study examines whether individuals' technological innovativeness influences their perceptions of a VR tourism experience and, in turn, their intention to recommend the experience. The study provides a VR experience to 405 tourists at a winery. The results reveal that the tourists' technological innovativeness influences their perception of enjoyment, experience quality, and satisfaction. These findings suggest that, when developing or distributing VR content, the technological innovativeness of the audience is important to consider. The findings have theoretical and practical value, with direct implications for tourism professionals and policymakers.
The access to the final selection minute is only available to applicants.
Please check the confirmation e-mail of your application to obtain the access code.