Export 9189 results:
Sort by: Author Title Type [ Year  (Desc)]
2023
López-Rojas, Víctor, Lars B. Clemmensen, Jesper Milàn, Oliver Wings, Nicole Klein, and Octávio Mateus. "A new phytosaur species (Archosauriformes) from the Upper Triassic of Jameson Land, central East Greenland." Journal of Vertebrate PaleontologyJournal of Vertebrate Paleontology (2023): e2181086. Abstracta_new_phytosaur_species_archosauriformes_from_the_upper_triassic_of_jameson_land_central_east_greenland.pdfWebsite

ABSTRACTHerein we describe phytosaurs from thin fluvial overbank sandstones of the Upper Triassic Malmros Klint Formation of the Fleming Fjord Group (central East Greenland). The new sample includes more than 150 disarticulated bones and teeth from small to large specimens belonging to at least four individuals. The fossils mostly consist of teeth and postcranial elements and permit the recognition of a new species of Mystriosuchus, M. alleroq, diagnosed by an L-shaped quadratojugal whose anterior suture trends anterodorsally and a tripartite degree of heterodonty. Humeral diaphyseal histology of one specimen reveals a fairly compact cortex that surrounds a cancellous medullary region followed by a remodeling zone containing scattered secondary osteons. Primary bone tissue is parallel-fibred with a moderate to low vascular density. The cortex is cyclically interrupted by distinct growth marks indicating a seasonal environment. A change in growth rate from moderate to low is documented within the outer cortex, indicating that at least this individual was close to somatic maturity. Mystriosuchus has formerly been known as an exclusively European taxon. The new findings support the European faunal influence in East Greenland during the Late Triassic inferred from other taxa such as temnospondyls and archosaurs. The mid-late Norian age of European Mystriosuchus suggests an additional age constraint for the vertebrate-bearing portion of the Malmros Klint Formation.

Matos, Ricardo JR, Jorge C. Silva, Paula I. P. Soares, and João Paulo Borges. "Polyvinylpyrrolidone Nanofibers Incorporating Mesoporous Bioactive Glass for Bone Tissue Engineering." 8.2 (2023): 206. Abstract
n/a
Tavares, Francisco JTM, Paula I. P. Soares, Jorge Carvalho Silva, and João Paulo Borges. "Preparation and in vitro characterization of magnetic CS/PVA/HA/pSPIONs scaffolds for magnetic hyperthermia and bone regeneration." 24.2 (2023): 1128. Abstract
n/a
Chaparro, Catarina IP, Beatriz T. Simões, João P. Borges, Miguel ARB Castanho, Paula I. P. Soares, and Vera Neves. "A promising approach: magnetic nanosystems for Alzheimer’s disease theranostics." 15.9 (2023): 2316. Abstract
n/a
Trovão, Filipa, Viviana G. Correia, Frederico M. Lourenço, Diana O. Ribeiro, Ana Luísa Carvalho, Angelina S. Palma, and Benedita A. Pinheiro. "The structure of a Bacteroides thetaiotaomicron carbohydrate-binding module provides new insight into the recognition of complex pectic polysaccharides by the human microbiome." (2023): 100084. AbstractWebsite

TheBacteroides thetaiotaomicronhas developed a consortium of enzymes capable of overcoming steric constraints and degrading, in a sequential manner, the complex rhamnogalacturonan II (RG-II) polysaccharide. BT0996 protein acts in the initial stages of the RGII depolymerisation, where its two catalytic modules remove the terminal monosaccharides from RG-II side chains A and B. BT0996 is modular and has three putative carbohydrate-binding modules (CBMs) for which the roles in the RG-II degradation are unknown. Here, we present the characterisation of themoduleat the C-terminal domain, which we designated BT0996C. The high-resolution structure obtained by X-ray crystallography reveals that the protein displays a typical β-sandwich fold with structural similarity to CBMs assigned to families 6 and 35. The distinctive features are: 1) the presence of several charged residues at the BT0996-C surface creating a large, broad positive lysine-rich patch that encompasses the putative binding site; and 2) the absence of the highly conserved binding-site signatures observed in CBMs from families 6 and 35, such as region A tryptophan and region C asparagine. These findings hint at a binding mode of BT0996-C not yet observed in its homologues. In line with this, carbohydrate microarrays and microscale thermophoresis show the ability of BT0996-C to bind α1-4-linked polygalacturonic acid, and that electrostatic interactions are essential for the recognition of the anionic polysaccharide. The results support the hypothesis that BT0996-C may have evolved to potentiate the action of BT0996 catalytic modules on the complex structure of RG-II by binding to the polygalacturonic acid backbone sequence.

Gavinho, Sílvia Rodrigues, Bruno Miguel Gonçalves Melo, João Paulo Borges, Jorge Carvalho Silva, and Manuel Pedro Fernandes Graça. "Thermal, Structural, Morphological and Electrical Characterization of Cerium-Containing 45S5 for Metal Implant Coatings." 13.2 (2023): 294. Abstract
n/a
BARRULAS, RAQUEL ALEXANDRA VALADARES, DANIEL FERREIRA, VALENTINA CHIAPPARINO, MARCILEIA ZANATTA, CARLOS A. GARCÍA-GONZÁLEZ, João Paulo Miranda Ribeiro Borges, and MARTA CRISTINA PARRACHO CANÇADO CORVO. "Unlocking New Possibilities: The Synergy Between Ionic Liquids and Porous M0aterials." 2023. Abstract
n/a
Silva, Ana B. P., Ana R. Jesus, Daniela A. S. Agostinho, José M. S. S. Esperança, Alexandre Paiva, Ana R. C. Duarte, and Patrícia M. Reis. "Using dicationic ionic liquids to upgrade the cytotoxicity and solubility of poorly water-soluble drugs." 3.1 (2023): 100052. AbstractWebsite

New dicationic ionic liquids (DcILs) based on carboxylic acid-derived, N-acetyl amino acid-derived or bromide anions, and ammonium cations were synthesized and characterized. DcILs were employed as co-solvents to improve the solubility of ibuprofen and ketoprofen belonging to BCS class II. These DcILs demonstrated to be less cytotoxic towards fibroblasts L929 cells and contributed to an augment in the solubility of both drugs when compared with monocationic ionic liquids (McILs). The cytotoxic profile of some of these ILs was established, and when the linker between two ammonium cations was an ether group or a short alkyl chain an IC50 higher than 200 mM for fibroblasts L929 cells was achieved. The anion structure showed to be a key factor in the solubility of both drugs, being the family of carboxylic acid-derived, the one that presented the most significant effect, followed by N-acetyl amino acid-derived and finally bromide. The two dimensional 1H1H– NOESY NMR spectra showed the interaction between the IL and the two oral drugs, responsible for the improvement of their solubility. The lipophilicity (logP) of ibuprofen and ketoprofen reduced in the presence of these new DcILs.

Pauleta, Sofia R., Raquel Grazina, Marta S. P. Carepo, José J. G. Moura, and Isabel Moura. "2.06 - Iron-sulfur clusters – functions of an ancient metal site." Reference Module in Chemistry, Molecular Sciences and Chemical Engineering. Elsevier, 2023. Abstract

Iron-sulfur clusters are ubiquitous and ancient prosthetic groups that are present in all kingdoms of life. In the 1960s, they were recognized to play a role in electron-transfer reactions, but since then several other functions were identified, which can be attributed to their flexible coordination and redox properties. In here, the canonical iron-sulfur clusters, as well as the ones with other coordinating ligands will be described. The chapter has also been updated to account for the advances in the knowledge of complex iron-sulfur clusters of nitrogenase and hydrogenases. In addition, the role of iron-sulfur clusters in metabolic regulation, as sensors of gases (nitric oxide, oxygen), iron and cellular content of iron-sulfur clusters, cellular redox status, and redox cycling compounds, as well as their role in DNA processing enzymes, and their involvement in catalysis of a wide range of reactions will be described. Iron-sulfur clusters also participate in their biosynthetic and repair pathways. The knowledge in this field as evolved tremendously in recent years, which would require a complete chapter devoted to it by itself, reason why the authors have decided not to include this subject in this chapter. The chapter is an update of the one published in the previous edition, focusing on the recent advances mostly on the iron-sulfur clusters involved in new catalytic functions, sensor mechanisms and DNA processing.

Pinheiro, Daniel, Pedro Amaro, Jorge Machado, Mauro Guerra, and José Paulo Santos. "Angular distribution of characteristic X-rays following electron impact ionization." Radiation Physics and Chemistry. 203 (2023). Abstract

In this paper, we present a theoretical study of the X-ray fluorescence emission after vacancy of K-shell due to electron impact ionization. In particular, we focus on the angular distributions of the characteristic Kα emission lines following this process. Rh was chosen for the analysis since it is a common element in X-ray tube anodes. In this analysis we also considered some elements along the period-4, i.e., Ni, Cu and Co as case-studies. In doing so, we studied the magnetic sub-level population of the ionized states, which is directly related to the angular distribution of the emission. A relative low angular distribution for the Kα emission of Rh of 0.5% was observed, which makes the assumption of isotropic emission correct for most studies. Moreover, a comparison with the respective angular emission for adjacent elements in the fourth period of the periodic table shows that this isotropy is attributed to a small total angular momentum of the resulting configurations after ionization, as well as to opposite angular distributions of the various transitions, which average to a maximum of 0.7% angular asymmetry in Ni.

Pinheiro, Daniel, André Fernandes, César Godinho, Jorge Machado, Gonçalo Baptista, Filipe Grilo, Luís Sustelo, Jorge M. Sampaio, Pedro Amaro, Roberta G. Leitão, José P. Marques, Fernando Parente, Paul Indelicato, Miguel de Avillez, José Paulo Santos, and Mauro Guerra. "K- and L-shell theoretical fluorescence yields for the Fe isonuclear sequence." Radiation Physics and Chemistry. 203 (2023): 110594. Abstract

In this work, we present K- and L- shell fluorescence yield values of the full isonuclear sequence of Fe ions, using a state-of-the-art multiconfiguration Dirac–Fock approach. These results may be of importance for spectral fitting and plasma modeling, both in laboratory and astrophysical studies, where Fe is an important benchmark element. The K-shell fluorescence yields were found to be very similar up to the removal of 14 electrons.

Dinis, Duarte Caldeira, José Rui Figueira, and Ângelo Palos Teixeira. "A multiple criteria approach for ship risk classification: An alternative to the Paris MoU Ship Risk Profile." Socio-Economic Planning Sciences. 90 (2023): 101718. AbstractWebsite
n/a
Diening, Lars, Oleksiy Karlovych, and Eugene Shargorodsky. "Addendum to "On interpolation of reflexive variable Lebesgue spaces on which the Hardy–Littlewood maximal operator is bounded"." Georgian Mathematical Journal . 30.2 (2023): 211-212.Website
Faggiano, E., A. Sacristán, H. Rocha, and M. Santacruz-Rodríguez Addressing the congruence and similarity of figures with technology: A cross-national comparison. ICTMT., 2023.
Guillaume, Alexandre R. D., Octávio Mateus, and Miguel Moreno-Azanza. "The Albanerpetontidae (Lissamphibia) from the Lourinhã Formation (Upper Jurassic, Portugal)." The Anatomical Record. 306.#S1 (2023): 116-118. Abstractguillaume_et_al_2023_albanerpetontidae_lissamphibia.pdfWebsite

n/a

Rocha, H. "Analyzing teachers’ knowledge based on their approach to the information provided by technology." European Journal of Science and Mathematics Education. 11.1 (2023): 132-145. AbstractWebsite

Teachers’ knowledge plays a central role in technology integration. In this study we analyze situations, where there is some divergence between the mathematical results and the information offered by the graphing calculator (lack of mathematical fidelity), putting the focus in the teachers and in their approaches. The goal of this study is to analyze, in the light of knowledge for teaching mathematics with technology (KTMT) model, the teachers’ professional knowledge, assuming the situations of lack of mathematical fidelity as having the potential to reveal some characteristics of their knowledge. Specifically, considering the teaching of functions at 10th grade (age 16), we intend to analyze: (1) What knowledge do the teachers have of technology and of its mathematical fidelity? (2) What can the teachers’ options related to situations of lack of mathematical fidelity tell us about their knowledge in other KTMT domains? The study adopts a qualitative and interpretative approach based on the case studies of two teachers. Data were collected by interviews and class observation, being the analysis guided by the KTMT model. The main result points to the relevance of the mathematics and technology knowledge. However, there is evidence of some difficulties to integrate the information provided by the technology with the mathematics, and also of some interference of the teaching and learning and technology knowledge, and specifically of the knowledge related to the students. This suggests that the analysis of the teachers’ actions in relation to situations of lack of mathematical fidelity, can be useful to characterize their KTMT.

Moniz, António B., Marta Candeias, and Nuno Boavida. "Artificial Generative Intelligence and Work – Portugal." Generative Artificial Intelligence – Opportunities, Risks, and Policy Challenges. Eds. Bjørn Bedsted, Nicklas Bang Bådum, Reinhard Grünwald, Steffen Albrecht, Tore Tennøe, Ferran Domínguez, and Clara Marsan. Barcelona: EPTA, 2023. 70-77.report_en_2.pdf
Ferreira, G., H. Rocha, and A. Rodrigues As conexões matemáticas na resolução de problemas. Atas do EIEM 2023 - Encontro em Investigação em Educação Matemática. Aveiro: SPIEM, 2023.
de Oliveira, Ivone Regina, Isabela dos Santos Gonçalves, Kennedy Wallace dos Santos, Maria Carmo Lança, Tânia Vieira, Jorge Carvalho Silva, Ibrahim Fatih Cengiz, Rui Luís Reis, Joaquim Miguel Oliveira, and João Paulo Miranda Ribeiro Borges. "Biocomposite Macrospheres Based on Strontium-Bioactive Glass for Application as Bone Fillers." ACS Materials Au. 3 (2023): 646-658. AbstractWebsite

Traditional bioactive glass powders are typically composed of irregular particles that can be packed into dense configurations presenting low interconnectivity, which can limit bone ingrowth. The use of novel biocomposite sphere formulations comprising bioactive factors as bone fillers are most advantageous, as it simultaneously allows for packing the particles in a 3-dimensional manner to achieve an adequate interconnected porosity, enhanced biological performance, and ultimately a superior new bone formation. In this work, we develop and characterize novel biocomposite macrospheres of Sr-bioactive glass using sodium alginate, polylactic acid (PLA), and chitosan (CH) as encapsulating materials for finding applications as bone fillers. The biocomposite macrospheres that were obtained using PLA have a larger size distribution and higher porosity and an interconnectivity of 99.7%. Loose apatite particles were observed on the surface of macrospheres prepared with alginate and CH by means of soaking into a simulated body fluid (SBF) for 7 days. A dense apatite layer was formed on the biocomposite macrospheres' surface produced with PLA, which served to protect PLA from degradation. In vitro investigations demonstrated that biocomposite macrospheres had minimal cytotoxic effects on a human osteosarcoma cell line (SaOS-2 cells). However, the accelerated degradation of PLA due to the degradation of bioactive glass may account for the observed decrease in SaOS-2 cells viability. Among the biocomposite macrospheres, those composed of PLA exhibited the most promising characteristics for their potential use as fillers in bone tissue repair applications.

Karlovych, Oleksiy, and Eugene Shargorodsky. "The Coburn lemma and the Hartman-Wintner-Simonenko theorem for Toeplitz operators on abstract Hardy spaces." Integral Equations and Operator Theory. 95 (2023): 6.Website
Boavida, Nuno, Isabel Roque, and António B. Moniz. "Collective Voice and Organizing in Digital Labour Platforms in Portugal." Journal of Labor and Society (2023): 1-25.Website
Moniz, António B., Nuno Boavida, Csaba Makó, Bettina-Johanna Krings, and Pablo Sanz de Miguel. "Conclusion: Where is worker representation going? Diverse pathways for platform workers' collective strategies." Digital labour platforms: Representing workers in Europe . Eds. A. B. Moniz, and et al. Famalicão: Humus/CICS.NOVA, 2023. 231-244.
Moniz, António B., and Nuno Boavida. "Contextualising digital platform work in Portugal." Digital labours platforms: Representing workers in Europe. Eds. A. B. Moniz, and et al. Famalicão: Humus/CICS.NOVA, 2023. 29-34.