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2023
Rotatori, FM, A. A. Chiarenza, M. Moreno-Azanza, and O. Mateus Rise of a dinasty: macroevolutionary and biogeographic patterns of iguanodontian dinosaurs across the Jurassic–Cretaceous transition. EAVP Annual Conference of the European Association of Vertebrate Palaeontologists. Palaeovertebrata, Special Volume 1-23. DOI: 10.18563/pv.eavp2023, 2023. Abstract
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Ramos, António, Brisid Isufi, and Rui Marreiros. "SEISMIC BEHAVIOR OF SLAB–COLUMN CONNECTIONS USING HIGH PERFORMANCE FIBER REINFORCED CONCRETES." American Concrete Institute, ACI Special Publication. Vol. SP-357. 2023. 123-138. Abstract
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Ramos, António Pinho, Brisid Isufi, Rui Marreiros, Dario Coronelli, Teresa Netti, Marco Lamperti Tornaghi, Georgios Tsionis, and Aurelio Muttoni. "Seismic Performance of Strengthened Slab-Column Connections in a Full-Scale Test." Journal of Earthquake Engineering. 27 (2023): 2299-2318. AbstractWebsite
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Nóbrega, Cláudia S., Ana Luísa Carvalho, Maria João Romão, and Sofia R. Pauleta. "Structural Characterization of Neisseria gonorrhoeae Bacterial Peroxidase—Insights into the Catalytic Cycle of Bacterial Peroxidases." International Journal of Molecular Sciences. 24 (2023). AbstractWebsite

Neisseria gonorrhoeae is an obligate human pathogenic bacterium responsible for gonorrhea, a sexually transmitted disease. The bacterial peroxidase, an enzyme present in the periplasm of this bacterium, detoxifies the cells against hydrogen peroxide and constitutes one of the primary defenses against exogenous and endogenous oxidative stress in this organism. The 38 kDa heterologously produced bacterial peroxidase was crystallized in the mixed-valence state, the active state, at pH 6.0, and the crystals were soaked with azide, producing the first azide-inhibited structure of this family of enzymes. The enzyme binds exogenous ligands such as cyanide and azide, which also inhibit the catalytic activity by coordinating the P heme iron, the active site, and competing with its substrate, hydrogen peroxide. The inhibition constants were estimated to be 0.4 ± 0.1 µM and 41 ± 5 mM for cyanide and azide, respectively. Imidazole also binds and inhibits the enzyme in a more complex mechanism by binding to P and E hemes, which changes the reduction potential of the latest heme. Based on the structures now reported, the catalytic cycle of bacterial peroxidases is revisited. The inhibition studies and the crystal structure of the inhibited enzyme comprise the first platform to search and develop inhibitors that target this enzyme as a possible new strategy against N. gonorrhoeae.

Duarte, Marlene, Victor D. Alves, Márcia Correia, Catarina Caseiro, Luís M. A. Ferreira, Maria João Romão, Ana Luísa Carvalho, Shabir Najmudin, Edward A. Bayer, Carlos M. G. A. Fontes, and Pedro Bule. "Structure-function studies can improve binding affinity of cohesin-dockerin interactions for multi-protein assemblies." International Journal of Biological Macromolecules. 224 (2023): 55-67. AbstractWebsite

The cellulosome is an elaborate multi-enzyme structure secreted by many anaerobic microorganisms for the efficient degradation of lignocellulosic substrates. It is composed of multiple catalytic and non-catalytic components that are assembled through high-affinity protein-protein interactions between the enzyme-borne dockerin (Doc) modules and the repeated cohesin (Coh) modules present in primary scaffoldins. In some cellulosomes, primary scaffoldins can interact with adaptor and cell-anchoring scaffoldins to create structures of increasing complexity. The cellulosomal system of the ruminal bacterium, Ruminococcus flavefaciens, is one of the most intricate described to date. An unprecedent number of different Doc specificities results in an elaborate architecture, assembled exclusively through single-binding-mode type-III Coh-Doc interactions. However, a set of type-III Docs exhibits certain features associated with the classic dual-binding mode Coh-Doc interaction. Here, the structure of the adaptor scaffoldin-borne ScaH Doc in complex with the Coh from anchoring scaffoldin ScaE is described. This complex, unlike previously described type-III interactions in R. flavefaciens, was found to interact in a dual-binding mode. The key residues determining Coh recognition were also identified. This information was used to perform structure-informed protein engineering to change the electrostatic profile of the binding surface and to improve the affinity between the two modules. The results show that the nature of the residues in the ligand-binding surface plays a major role in Coh recognition and that Coh-Doc affinity can be manipulated through rational design, a key feature for the creation of designer cellulosomes or other affinity-based technologies using tailored Coh-Doc interactions.

Ribeiro, G., G. Ferreira, U. D. Menda, M. Alexandre, M. J. Brites, M. A. Barreiros, S. Jana, H. Águas, R. Martins, P. A. Fernandes, P. Salomé, and MJ Mendes. "Sub-Bandgap Sensitization of Perovskite Semiconductors via Colloidal Quantum Dots Incorporation." Nanomaterials. 13 (2023). AbstractWebsite
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Menda, U. D., G. Ribeiro, J. Deuermeier, E. López, D. Nunes, S. Jana, I. Artacho, R. Martins, I. Mora-Seró, MJ Mendes, and I. Ramiro. "Thermal-Carrier-Escape Mitigation in a Quantum-Dot-In-Perovskite Intermediate Band Solar Cell via Bandgap Engineering." ACS Photonics. 10 (2023): 3647-3655. AbstractWebsite
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Vicente da Silva, M., and A. N. Antão. "Three-dimensional Limit Analysis using the Extended-Matsuoka–Nakai yield criterion." Computers and Geotechnics. 161 (2023): 105526. AbstractWebsite

This paper investigates the implementation of the Extended-Matsuoka–Nakai yield criterion on a strict Limit Analysis finite element formulation. The current approach is based on a three-field mixed finite element model and the Alternating Direction Method of Multipliers optimization algorithm. With the support of duality principles two variants are derived, the lower bound and the upper bound element. The main novelty of this work is the development of an efficient iterative predictor–corrector scheme, customized for the Extended-Matsuoka–Nakai. This scheme is an indispensable requirement for this formulation. To conclude four numerical examples are presented to assess the effectiveness and efficiency of the numerical tool.

Santana, T., A. Antão, N. Guerra, and M. Vicente da Silva. "Upper bounds for the three-dimensional seismic active earth pressure coefficients." Géotechnique Letters. 13 (2023): 65-74. AbstractWebsite

A numerical implementation of the upper-bound theorem of limit analysis is applied to determine two-dimensional (2D) and three-dimensional (3D) active horizontal earth pressure coefficients considering seismic actions through a horizontal seismic coefficient. Results are obtained for vertical wall, horizontal soil, different friction angles of the soil, soil-to-wall friction ratios, horizontal seismic coefficients and wall width-to-height ratios. The few cases for which 3D active earth pressure coefficients are available in the literature using upper-bound methods were used for comparison with the corresponding earth pressure coefficients obtained in this study. This showed a general improvement of these results, which allows expecting a good accuracy for the set of cases studied. The ratios between the 3D and 2D horizontal active earth pressure coefficients are found to be practically independent of the soil-to-wall friction ratio. An equation is proposed for calculating these ratios. This equation can be easily used in the design of geotechnical structures requiring the determination of 3D active earth pressure coefficients.

Coelho, João, Ricardo F. Correia, Sara Silvestre, Tomás Pinheiro, Ana C. Marques, Rosário M. P. Correia, Joana Vaz Pinto, Elvira Fortunato, and Rodrigo Martins. "{Paper-based laser-induced graphene for sustainable and flexible microsupercapacitor applications}." Microchimica Acta. 190 (2023): 1-10. Abstract

Laser-induced graphene (LIG) is as a promising material for flexible microsupercapacitors (MSCs) due to its simple and cost-effective processing. However, LIG-MSC research and production has been centered on non-sustainable polymeric substrates, such as polyimide. In this work, it is presented a cost-effective, reproducible, and robust approach for the preparation of LIG structures via a one-step laser direct writing on chromatography paper. The developed strategy relies on soaking the paper in a 0.1 M sodium tetraborate solution (borax) prior to the laser processing. Borax acts as a fire-retardant agent, thus allowing the laser processing of sensitive substrates that other way would be easily destroyed under the high-energy beam. LIG on paper exhibiting low sheet resistance (30 $Ømega$ sq−1) and improved electrode/electrolyte interface was obtained by the proposed method. When used as microsupercapacitor electrodes, this laser-induced graphene resulted in specific capacitances of 4.6 mF cm−2 (0.015 mA cm−2). Furthermore, the devices exhibit excellent cycling stability (> 10,000 cycles at 0.5 mA cm−2) and good mechanical properties. By connecting the devices in series and parallel, it was also possible to control the voltage and energy delivered by the system. Thus, paper-based LIG-MSC can be used as energy storage devices for flexible, low-cost, and portable electronics. Additionally, due to their flexible design and architecture, they can be easily adapted to other circuits and applications with different power requirements. Graphical Abstract: [Figure not available: see fulltext.]

Pinheiro, Ana, Andreia Ruivo, Marta Ferro, Joana Vaz Pinto, Jonas Deuermeier, Tiago Mateus, Ana Santa, Manuel J. Mendes, Rodrigo Martins, Sandra Gago, C. A. T. Laia, and Á. Hugo. "{Parylene-Sealed Perovskite Nanocrystals Down-Shifting Layer for Luminescent Spectral Matching in Thin Film Photovoltaics}." (2023). Abstract
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Duval, Louis, Rοbert Loetzsch, Heinrich Beyer, Dariusz Banaś, Perla Dergham, Jan Glorius, Robert E. Grisenti, Mauro Guerra, Alexandre Gumberidze, Pierre-Michel Hillenbrand, Paweł Jagodziński, Emily Lamour, Yuri Litvinov, Jorge Machado, Gerhard Paulus, Nancy Paul, Nikolaos Petridis, Jose-Paulo Santos, Marius Scheidel, Ragandeep S. Sidhu, Uwe Spillmann, Sébastien Steydli, Karol Szary, Sergiy Trotsenko, Ingo Uschmann, Günther Weber, Thomas Stöhlker, Paul Indelicato, and Martino Trassinelli. "{X-ray spectroscopy of few-electron uranium ions for tests of QED}." Proceedings of FAIR next generation scientists - 7th Edition Workshop — PoS(FAIRness2022). Vol. 419. 2023. 012. Abstract
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2022
Correia, Ricardo, Jonas Deuermeier, Maria Rosário Correia, Joana {Vaz Pinto}, João Coelho, Elvira Fortunato, and Rodrigo Martins. "{Biocompatible Parylene-C Laser-Induced Graphene Electrodes for Microsupercapacitor Applications}." ACS Applied Materials {&} Interfaces. 14 (2022): 46427-46438. AbstractWebsite
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Silva, Daniela, Catarina S. Monteiro, Susana O. Silva, Orlando Frazão, Joana V. Pinto, Maria Raposo, Paulo A. Ribeiro, and Susana Sério. "{Sputtering Deposition of TiO2 Thin Film Coatings for Fiber Optic Sensors}." Photonics. 9 (2022): 342. Abstract

Thin films of titanium dioxide (TiO2) and titanium (Ti) were deposited onto glass and optical fiber supports through DC magnetron sputtering, and their transmission was characterized with regard to their use in optical fiber-based sensors. Deposition parameters such as oxygen partial pressure, working pressure, and sputtering power were optimized to attain films with a high reflectance. The films deposited on glass supports were characterized by UV-Vis spectroscopy, X-ray diffraction (XRD), and scanning electron microscopy (SEM). Regarding the deposition parameters, all three parameters were tested simultaneously, changing the working pressure, the sputtering power, and the oxygen percentage. It was possible to conclude that a lower working pressure and higher applied power lead to films with a higher reflectance. Through the analysis of the as-sputtered thin films using X-ray diffraction, the deposition of both Ti and TiO2 films was confirmed. To study the applicability of TiO2 and Ti in fiber sensing, several thin films were deposited in single mode fibers (SMFs) using the sputtering conditions that revealed the most promising results in the glass supports. The sputtered TiO2 and Ti thin films were used as mirrors to increase the visibility of a low-finesse Fabry–Perot cavity and the possible sensing applications were studied.

Caeiro, Frederico, L{\'ı}gia Henriques-Rodrigues, and Ivette M. Gomes. "The Use of Generalized Means in the Estimation of the Weibull Tail Coefficient." Computational and Mathematical Methods. 2022 (2022): 1-12. AbstractWebsite
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Rovisco, Ana, Maria Morais, Rita Branquinho, Elvira Fortunato, Rodrigo Martins, and Pedro Barquinha. "{Microwave-Assisted Synthesis of Zn2SnO4 Nanostructures for Photodegradation of Rhodamine B under UV and Sunlight}." Nanomaterials. 12 (2022): 2119. AbstractWebsite

The contamination of water resources by pollutants resulting from human activities represents a major concern nowadays. One promising alternative to solve this problem is the photocatalytic process, which has demonstrated very promising and efficient results. Oxide nanostructures are interesting alternatives for these applications since they present wide band gaps and high surface areas. Among the photocatalytic oxide nanostructures, zinc tin oxide (ZTO) presents itself as an eco-friendly alternative since its composition includes abundant and non-toxic zinc and tin, instead of critical elements. Moreover, ZTO nanostructures have a multiplicity of structures and morphologies possible to be obtained through low-cost solution-based syntheses. In this context, the current work presents an optimization of ZTO nanostructures (polyhedrons, nanoplates, and nanoparticles) obtained by microwave irradiation-assisted hydrothermal synthesis, toward photocatalytic applications. The nanostructures' photocatalytic activity in the degradation of rhodamine B under both ultraviolet (UV) irradiation and natural sunlight was evaluated. Among the various morphologies, ZTO nanoparticles revealed the best performance, with degradation > 90% being achieved in 60 min under UV irradiation and in 90 min under natural sunlight. The eco-friendly production process and the demonstrated ability of these nanostructures to be used in various water decontamination processes reinforces their sustainability and the role they can play in a circular economy.

Firmino, Rita, Emanuel Carlos, Joana Vaz Pinto, Jonas Deuermeier, Rodrigo Martins, Elvira Fortunato, Pedro Barquinha, and Rita Branquinho. "{Solution Combustion Synthesis of Hafnium-Doped Indium Oxide Thin Films for Transparent Conductors}." Nanomaterials. 12 (2022): 2167. AbstractWebsite

{\textless}p{\textgreater}Indium oxide (In2O3)-based transparent conducting oxides (TCOs) have been widely used and studied for a variety of applications, such as optoelectronic devices. However, some of the more promising dopants (zirconium, hafnium, and tantalum) for this oxide have not received much attention, as studies have mainly focused on tin and zinc, and even fewer have been explored by solution processes. This work focuses on developing solution-combustion-processed hafnium (Hf)-doped In2O3 thin films and evaluating different annealing parameters on TCO's properties using a low environmental impact solvent. Optimized TCOs were achieved for 0.5 M{%} Hf-doped In2O3 when produced at 400 °C, showing high transparency in the visible range of the spectrum, a bulk resistivity of 5.73 × 10−2 $Ømega$.cm, a mobility of 6.65 cm2/V.s, and a carrier concentration of 1.72 × 1019 cm−3. Then, these results were improved by using rapid thermal annealing (RTA) for 10 min at 600 °C, reaching a bulk resistivity of 3.95 × 10 −3 $Ømega$.cm, a mobility of 21 cm2/V.s, and a carrier concentration of 7.98 × 1019 cm−3, in air. The present work brings solution-based TCOs a step closer to low-cost optoelectronic applications.{\textless}/p{\textgreater}

Madeira, Ricardo MD, Tânia Vieira, Jorge C. Silva, Ivone R. Oliveira, João P. Borges, M. M. R. A. Lima, and Carmo M. Lança Piezoelectric Calcium Modified Barium Titanate for Bone Regeneration. Vol. 8. Materials Proceedings 2022, Vol. 8, Page 121, 8. Basel Switzerland: Multidisciplinary Digital Publishing Institute, 2022. Abstract

Solid state reaction was used to produced barium titanate modified with calcium (BCT) showing the presence of the piezoelectric tetragonal phase after sintering at 1350 °C. Bioglass 45S5 (BG) was synthetized by sol-gel route. From these two materials and commercial hydroxyapatite (HAp) were obtained composites. The BG produced showed some cytotoxic character that was weakened by passivation. All other materials were non-cytotoxic. Contact polarization at constant temperature was chosen composites polarization. Electric/dielectric properties were evaluated by thermally stimulated depolarization currents (TSDC). The material showed bioactivity with the composite with BCT/BG/HAp 90/5/5 (wt%) showing increased bioactivity. In vitro test showed high proliferation rates for the composites.

Oliveira, IR, AM Barbosa, KW Santos, MC Lança, M. M. R. A. Lima, T. Vieira, JC Silva, and J. P. Borges. "Properties of strontium-containing BG 58S produced by alkali-mediated sol-gel process." Ceramics International (2022). AbstractWebsite

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Mateus, Ayana, and Frederico Caeiro. "Improved Shape Parameter Estimation for the Three-Parameter Log-Logistic Distribution." Computational and Mathematical Methods. 2022 (2022): 1-13. AbstractWebsite
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Fonseca, Amândio, Corneliu Cismasiu, and Ildi Cismasiu. "Avaliação da vulnerabilidade sísmica de um edifício pombalino através de análise dinâmica incremental." Jornadas Portuguesas de Engenharia de Estruturas (JPEE). Lisboa: LNEC, APEE, GPBE, SPES, 2022. art_jpee2022_266_afccic_v8.pdf
Amaro, P., A. Adamczak, Abdou M. Ahmed, L. Affolter, F. D. Amaro, P. Carvalho, T. L. Chen, L. M. P. Fernandes, M. Ferro, D. Goeldi, T. Graf, M. Guerra, T. W. Hänsch, C. A. O. Henriques, Y. C. Huang, P. Indelicato, O. Kara, K. Kirch, A. Knecht, F. Kottmann, Y. W. Liu, J. Machado, M. Marszalek, R. D. P. Mano, C. M. B. Monteiro, F. Nez, J. Nuber, A. Ouf, N. Paul, R. Pohl, E. Rapisarda, J. M. F. dos Santos, J. P. Santos, P. A. O. C. Silva, L. Sinkunaite, J. T. Shy, K. Schuhmann, S. Rajamohanan, A. Soter, L. Sustelo, D. Taqqu, L. B. Wang, F. Wauters, P. Yzombard, M. Zeyen, and A. Antognini. "Laser excitation of the 1s-hyperfine transition in muonic hydrogen." SciPost Physics. 13 (2022). Abstract

The CREMA collaboration is pursuing a measurement of the ground-state hyperfine splitting (HFS) in muonic hydrogen (μp) with 1 ppm accuracy by means of pulsed laser spectroscopy to determine the two-photon-exchange contribution with 2×10-4 relative accuracy. In the proposed experiment, the μp atom undergoes a laser excitation from the singlet hyperfine state to the triplet hyperfine state, then is quenched back to the singlet state by an inelastic collision with a H2 molecule. The resulting increase of kinetic energy after the collisional deexcitation is used as a signature of a successful laser transition between hyperfine states. In this paper, we calculate the combined probability that a μp atom initially in the singlet hyperfine state undergoes a laser excitation to the triplet state followed by a collisional-induced deexcitation back to the singlet state. This combined probability has been computed using the optical Bloch equations including the inelastic and elastic collisions. Omitting the decoherence effects caused by the laser bandwidth and collisions would overestimate the transition probability by more than a factor of two in the experimental conditions. Moreover, we also account for Doppler effects and provide the matrix element, the saturation fluence, the elastic and inelastic collision rates for the singlet and triplet states, and the resonance linewidth. This calculation thus quantifies one of the key unknowns of the HFS experiment, leading to a precise definition of the requirements for the laser system and to an optimization of the hydrogen gas target where μp is formed and the laser spectroscopy will occur.

Gomes, G. J., V. J. G. Lúcio, and C. Cismasiu. "Development of a high-performance blast energy-absorbing system for building structures." AuxDefense2022 - 3rd World Conference on Advanced Materials for Defense. Guimarães, Portugal 2022.