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2022
Alves, R, Rodrigues J, Ramou E, Palma S, Roque A, Gamboa H.  2022.  Classification of Volatile Compounds with Morphological Analysis of e-nose Response, Feb. Proceedings of the 15th International Joint Conference on Biomedical Engineering Systems and Technologies - BIOSIGNALS. :31–39.: Scitepress AbstractPDF

Electronic noses (e-noses) mimic human olfaction, by identifying Volatile Organic Compounds (VOCs). This
work presents a novel approach that successfully classifies 11 known VOCs using the signals generated by
sensing gels in an in-house developed e-nose. The proposed signals’ analysis methodology is based on the
generated signals’ morphology for each VOC since different sensing gels produce signals with different shapes
when exposed to the same VOC. For this study, two different gel formulations were considered, and an average
f1-score of 84% and 71% was obtained, respectively. Moreover, a standard method in time series classification
was used to compare the performances. Even though this comparison reveals that the morphological approach
is not as good as the 1-nearest neighbour with euclidean distance, it shows the possibility of using descriptive
sentences with text mining techniques to perform VOC classification.

Oliveira, A, Ramou E, Teixeira G, Palma S, Roque A.  2022.  Incorporation of VOC-Selective Peptides in Gas Sensing Materials, feb. Proceedings of the 15th International Joint Conference on Biomedical Engineering Systems and Technologies. :25–34. AbstractPDFWebsite

Enhancing the selectivity of gas sensing materials towards specific volatile organic compounds (VOCs) is
challenging due to the chemical simplicity of VOCs as well as the difficulty in interfacing VOC selective
biological elements with electronic components used in the transduction process. We aimed to tune the
selectivity of gas sensing materials through the incorporation of VOC-selective peptides into gel-like gas
sensing materials. Specifically, a peptide (P1) known to discriminate single carbon deviations among benzene
and derivatives, along with two modified versions (P2 and P3), were integrated with gel compositions
containing gelatin, ionic liquid and without or with a liquid crystal component (ionogels and hybrid gels
respectively). These formulations change their electrical or optical properties upon VOC exposure, and were
tested as sensors in an in-house developed e-nose. Their ability to distinct and identify VOCs was evaluated
via a supervised machine learning classifier. Enhanced discrimination of benzene and hexane was detected
for the P1-based hybrid gel. Additionally, complementarity of the electrical and optical sensors was observed
considering that a combination of both their accuracy predictions yielded the best classification results for the
tested VOCs. This indicates that a combinatorial array in a dual-mode e-nose could provide optimal
performance and enhanced selectivity.

Alves-Barroco, C, Rivas-García L, Fernandes {AR}, Baptista {PV}.  2022.  Light Triggered Enhancement of Antibiotic Efficacy in Biofilm Elimination Mediated by Gold-Silver Alloy Nanoparticles, feb. Frontiers in Microbiology. 13:1–15.: Frontiers Research Foundation Abstract

Bacterial biofilm is a tri-dimensional complex community of cells at different metabolic stages involved in a matrix of self-produced extracellular polymeric substances. Biofilm formation is part of a defense mechanism that allows the bacteria to survive in hostile environments, such as increasing resistance or tolerance to antimicrobial agents, causing persistent infections hard to treat and impair disease eradication. One such example is bovine mastitis associated with Streptococcus dysgalactiae subsp. dysgalactiae (SDSD), whose worldwide health and economic impact is on the surge. As such, non-conventional nanobased approaches have been proposed as an alternative to tackle biofilm formation and to which pathogenic bacteria fail to adapt. Among these, metallic nanoparticles have gained significant attention, particularly gold and silver nanoparticles, due to their ease of synthesis and impact against microorganism growth. This study provides a proof-of-concept investigation into the use of gold-silver alloy nanoparticles (AuAgNPs) toward eradication of bacterial biofilms. Upon visible light irradiation of AuAgNPs there was considerable disturbance of the biofilms' matrix. The hindering of structural integrity of the biofilm matrix resulted in an increased permeability for entry of antibiotics, which then cause the eradication of biofilm and inhibit subsequent biofilm formation. Additionally, our results that AuAgNPs inhibited the formation of SDSD biofilms via distinct stress pathways that lead to the downregulation of two genes critical for biofilm production, namely, brpA-like encoding biofilm regulatory protein and fbpA fibronectin-binding protein A. This study provides useful information to assist the development of nanoparticle-based strategies for the active treatment of biofilm-related infections triggered by photoirradiation in the visible.

Lenis-Rojas, {OA}, Carvalho B, Cabral R, Silva M, Friães S, Roma-Rodrigues C, Meireles {MSH }, Gomes {CSB}, Fernández {JAA }, Vila {SF }, Rubiolo {JA }, Sanchez L, Baptista {PV}, Fernandes {AR}, Royo B.  2022.  Manganese(I) tricarbonyl complexes as potential anticancer agents, feb. JBIC Journal of Biological Inorganic Chemistry. 27:49–64., Number 1: Springer Abstract

The antiproliferative activity of [Mn(CO)3(N^N)Br] (N^N = phendione 1, bipy 3) and of the two newly synthesized Mn complexes [Mn(CO)3(acridine)(phendione)]OTf (2) and [Mn(CO)3(di-triazole)Br] (4) has been evaluated by MTS against three tumor cell lines A2780 (ovarian carcinoma), HCT116 (colorectal carcinoma), HCT116doxR (colorectal carcinoma resistant to doxorubicin), and in human dermal fibroblasts. The antiproliferative assay showed a dose-dependent effect higher in complex 1 and 2 with a selectivity toward ovarian carcinoma cell line 21 times higher than in human fibroblasts. Exposure of A2780 cells to IC50 concentrations of complex 1 and 2 led to an increase of reactive oxygen species that led to the activation of cell death mechanisms, namely via intrinsic apoptosis for 2 and autophagy and extrinsic apoptosis for 1. Both complexes do not target DNA or interfere with cell cycle progression but are able to potentiate cell migration and neovascularization (for 2) an indicative that their application might be directed for initial tumor stages to avoid tumor invasion and metastization and opening a new avenue for complex 2 application in regenerative medicine. Interestingly, both complexes do not show toxicity in both in vivo models (CAM and zebrafish). Graphical abstract: [Figure not available: see fulltext.]

Nuez-Martínez, M, Queralt-Martín M, Muñoz-Juan A, Aguilella {VM }, Laromaine A, Teixidor F, Viñas C, Pinto {CG }, Pinheiro T, Guerreiro {JF }, Mendes F, Roma-Rodrigues C, Baptista {PV}, Fernandes {AR}, Valic S, Marques F.  2022.  Boron clusters (ferrabisdicarbollides) shaping the future as radiosensitizers for multimodal (chemo/radio/PBFR) therapy of glioblastoma, dec. Journal of Materials Chemistry B. 10:9794–9815., Number 47: RSC - Royal Society of Chemistry Abstract

Glioblastoma multiforme (GBM) is the most common and fatal primary brain tumor, and is highly resistant to conventional radiotherapy and chemotherapy. Therefore, the development of multidrug resistance and tumor recurrence are frequent. Given the poor survival with the current treatments, new therapeutic strategies are urgently needed. Radiotherapy (RT) is a common cancer treatment modality for GBM. However, there is still a need to improve RT efficiency, while reducing the severe side effects. Radiosensitizers can enhance the killing effect on tumor cells with less side effects on healthy tissues. Herein, we present our pioneering study on the highly stable and amphiphilic metallacarboranes, ferrabis(dicarbollides) ([o-FESAN]− and [8,8′-I2-o-FESAN]−), as potential radiosensitizers for GBM radiotherapy. We propose radiation methodologies that utilize secondary radiation emissions from iodine and iron, using ferrabis(dicarbollides) as iodine/iron donors, aiming to achieve a greater therapeutic effect than that of a conventional radiotherapy. As a proof-of-concept, we show that using 2D and 3D models of U87 cells, the cellular viability and survival were reduced using this treatment approach. We also tested for the first time the proton boron fusion reaction (PBFR) with ferrabis(dicarbollides), taking advantage of their high boron (11B) content. The results from the cellular damage response obtained suggest that proton boron fusion radiation therapy, when combined with boron-rich compounds, is a promising modality to fight against resistant tumors. Although these results are encouraging, more developments are needed to further explore ferrabis(dicarbollides) as radiosensitizers towards a positive impact on the therapeutic strategies for GBM.

Twilley, D, Meyer D, Langhansova L, Mcgaw {LJ }, Madikizela B, Roma-Rodrigues C, Baptista, {P. V}, Fernandes {AR }, Lall N.  2022.  Short Lecture 4 {"}Evaluation of antiproliferative and anti-angiogenic activity of an ethanolic extract of Helichrysum odoratissimum (L.) Sweet against skin cancer{"}, dec. Planta Medica. 88:1398–1398., Number 15: Georg Thieme Verlag Abstract
n/a
Esteves, C, Palma SICJ, Costa HMA, Alves C, Santos GMC, Ramou E, Carvalho AL, Alves V, Roque ACA.  2022.  Tackling Humidity with Designer Ionic Liquid-Based Gas Sensing Soft Materials, dec. Advanced Materials. 34:2107205., Number 8: John Wiley & Sons, Ltd AbstractPDFWebsite

Relative humidity is simultaneously a sensing target and a contaminant in gas and volatile organic compound (VOC) sensing systems, where strategies to control humidity interference are required. An unmet challenge is the creation of gas-sensitive materials where the response to humidity is controlled by the material itself. Here, humidity effects are controlled through the design of gelatin formulations in ionic liquids without and with liquid crystals as electrical and optical sensors, respectively. In this design, the anions [DCA]− and [Cl]− of room temperature ionic liquids from the 1-butyl-3-methylimidazolium family tailor the response to humidity and, subsequently, sensing of VOCs in dry and humid conditions. Due to the combined effect of the materials formulations and sensing mechanisms, changing the anion from [DCA]− to the much more hygroscopic [Cl]−, leads to stronger electrical responses and much weaker optical responses to humidity. Thus, either humidity sensors or humidity-tolerant VOC sensors that do not require sample preconditioning or signal processing to correct humidity impact are obtained. With the wide spread of 3D- and 4D-printing and intelligent devices, the monitoring and tuning of humidity in sustainable biobased materials offers excellent opportunities in e-nose sensing arrays and wearable devices compatible with operation at room conditions.

Oliveira, AR, Mota C, Romão MJ, Pereira IAC.  2022.  The W/SeCys-FdhAB formate dehydrogenase from Desulfovibrio vulgaris Hildenborough, 2022/06/10. Encyclopedia of Inorganic and Bioinorganic Chemistry. :1-12. Abstract

Abstract The W/SeCys-FdhAB formate dehydrogenase from Desulfovibrio vulgaris Hildenborough is a dimeric periplasmic enzyme that catalyzes the reversible oxidation of formate and reduction of CO2. It belongs to the group of metal-dependent FDHs, with a tungsten at the active site coordinated by two pyranopterin guanine dinucleotides, a selenocysteine, and one labile sulfur atom. FdhAB has a remarkably high activity and unusual tolerance to oxygen, making it an ideal model system to study biological CO2 reduction.

Oliveira, AR, Mota C, Klymanska K, Biaso F, Romão MJ, Guigliarelli B, Pereira IC.  2022.  Spectroscopic and Structural Characterization of Reduced Desulfovibrio vulgaris Hildenborough W-FdhAB Reveals Stable Metal Coordination during Catalysis, 2022. ACS Chemical BiologyACS Chemical Biology. 17(7):1901-1909.: American Chemical Society AbstractWebsite

Metal-dependent formate dehydrogenases are important enzymes due to their activity of CO2 reduction to formate. The tungsten-containing FdhAB formate dehydrogenase from Desulfovibrio vulgaris Hildenborough is a good example displaying high activity, simple composition, and a notable structural and catalytic robustness. Here, we report the first spectroscopic redox characterization of FdhAB metal centers by EPR. Titration with dithionite or formate leads to reduction of three [4Fe–4S]1+ clusters, and full reduction requires Ti(III)–citrate. The redox potentials of the four [4Fe–4S]1+ centers range between −250 and −530 mV. Two distinct WV signals were detected, WDV and WFV, which differ in only the g2-value. This difference can be explained by small variations in the twist angle of the two pyranopterins, as determined through DFT calculations of model compounds. The redox potential of WVI/V was determined to be −370 mV when reduced by dithionite and −340 mV when reduced by formate. The crystal structure of dithionite-reduced FdhAB was determined at high resolution (1.5 Å), revealing the same structural alterations as reported for the formate-reduced structure. These results corroborate a stable six-ligand W coordination in the catalytic intermediate WV state of FdhAB.Metal-dependent formate dehydrogenases are important enzymes due to their activity of CO2 reduction to formate. The tungsten-containing FdhAB formate dehydrogenase from Desulfovibrio vulgaris Hildenborough is a good example displaying high activity, simple composition, and a notable structural and catalytic robustness. Here, we report the first spectroscopic redox characterization of FdhAB metal centers by EPR. Titration with dithionite or formate leads to reduction of three [4Fe–4S]1+ clusters, and full reduction requires Ti(III)–citrate. The redox potentials of the four [4Fe–4S]1+ centers range between −250 and −530 mV. Two distinct WV signals were detected, WDV and WFV, which differ in only the g2-value. This difference can be explained by small variations in the twist angle of the two pyranopterins, as determined through DFT calculations of model compounds. The redox potential of WVI/V was determined to be −370 mV when reduced by dithionite and −340 mV when reduced by formate. The crystal structure of dithionite-reduced FdhAB was determined at high resolution (1.5 Å), revealing the same structural alterations as reported for the formate-reduced structure. These results corroborate a stable six-ligand W coordination in the catalytic intermediate WV state of FdhAB.

Ramos, A, Isufi B, Marreiros R, Marchão C.  2022.  Utilização de BEDRF em Ligações Laje-Pilar sujeitas a Ações Horizontais Cíclicas, 2022. 6ªs Jornadas Portuguesas de Engenharia de Estruturas. , Lisbonartigo_bedrf_ciclico_jpee2022_final.pdf
Ramos, A, Isufi B, Marchão C, Marreiros R.  2022.  Utilização Racional de BEDRF em Ligações Laje-Pilar, 2022. 6ªs Jornadas Portuguesas de Engenharia de Estruturas. , Lisbonartigo_hpfrc_monotonico_jpee2022_final.pdf
Reljic, S, Cuadrado-Collados C, Oliveira Jardim E, Farrando-Perez J, Martinez-Escandell M, Silvestre-Albero J.  2022.  Activated carbon materials with a rich surface chemistry prepared from L-cysteine amino acid. Fluid Phase Equilibria. 558(113446)
Isufi, B, Relvas JP, Marchão C, Ramos A.  2022.  Behavior of flat slabs with partial use of high-performance fiber reinforced concrete under monotonic vertical loading. Engineering Structures. 264(August 2022):114471. AbstractWebsite

Reinforced concrete flat slabs are used worldwide in multi-story buildings. In these slabs, the design is often governed by punching shear and serviceability. The mitigation of these issues during design usually leads to increased raw material consumption and costs. Previous studies have shown that using Fiber Reinforced Concrete (FRC) or High-Strength Concrete (HSC) only at the vicinity of the column, while casting the rest of the slab with Normal Strength Concrete (NSC), can lead to an improved behavior under gravity loads in terms of both serviceability and ultimate capacity. Motivated by these results and the scarcity of previous tests, the present paper experimentally investigates the applicability of High-Performance Fiber Reinforced Concrete (HPFRC) as an alternative material that can be seen as an improvement over FRC and HSC, allowing a combination of ductility and strength. In addition, the HPFRC used in this paper is self-compacting, thus reducing the labor costs associated with concrete vibration. Five 150 mm thick flat slabs were tested under monotonically increasing punching load. The experimental variables were the flexural reinforcement ratio and the extent of the HPFRC zone. One of the specimens was cast only with NSC and served as a reference slab. Results show that the solution was effective for both flexural reinforcement ratios considered. Cracking load, maximum load, as well as the displacement capacity were increased significantly, even for a small extent of HPFRC (1.5 times the effective depth from the face of the column). Regarding the ultimate load capacity, it was observed an increase of 44% to 58% for the specimens with lower reinforcement ratio (0.64%) and between 15%–21% for the specimens with higher reinforcement ratio (0.96%). The results indicate that the use of HPFRC is a promising solution regarding both serviceability and ultimate limit state design of reinforced concrete flat slabs under gravity loading, with obvious advantages in material savings and labor costs.

Reljic, S, Cuadrado-Collados C, Farrando-Perez J, Jardim EO, Martinez-Escandell M, Silvestre-Albero J.  2022.  Carbon-based monoliths with improved thermal and mechanical properties for methane storage. Fuel. 324(124753)
da Rosa, RR, Silva PES, Saraiva DV, Kumar A, de Sousa AMP, Sebastião P, Fernandes SN, Godinho MH.  2022.  Cellulose Nanocrystal Aqueous Colloidal Suspensions: Evidence of Density Inversion at the Isotropic-liquid Crystal Phase Transition. Advanced Materials. n/a:2108227., Number n/a AbstractWebsite

Abstract The colloidal suspensions of aqueous cellulose nanocrystals (CNCs) are known to form liquid crystalline systems above certain critical concentrations. From an isotropic phase; tactoid formation; growth; and sedimentation have been determined as the genesis of a high-density cholesteric phase; which after drying; originates solid iridescent films. Herein; we report the coexistence of a liquid crystal upper phase and an isotropic bottom phase in CNC aqueous suspensions at isotropic-nematic phase separation for the first time. Furthermore; isotropic spindle-like domains are observed in the low-density liquid crystalline phase; and high-density liquid crystalline phases are also prepared. The CNCs isolated from the low- and high-density liquid crystalline phases are found to have similar average lengths; diameters; and surface charges. The existence of a liquid crystalline low-density phase is explained by the presence of air dissolved in the water present within the CNCs. The air dissolves out when the water solidifies into ice and remains within the CNCs. The self-adjustment of the cellulose chain conformation enables the entrapment of air within the CNCs and CNC buoyancy in aqueous suspensions. This article is protected by copyright. All rights reserved

Soares, Í, Faria J, Marques A, Ribeiro IAC, Baleizão C, Bettencourt A, Ferreira I, Baptista AC.  2022.  Drug Delivery from PCL/Chitosan Multilayer Coatings for Metallic Implants. ACS omega. 7:23096-23106.
Soares, Í, Faria J, Marques A, Ribeiro I, Baleizão C, Bettencourt A, Ferreira I, Baptista A.  2022.  Drug Delivery from PCL/Chitosan Multilayer Coatings for Metallic Implants. ACS Omega. 7(27):23096–23106.
I. Soares, Faria J, Marques AC, Ribeiro I, Baleizão C, Bettencourt A, Ferreira I, Baptista AC.  2022.  Drug delivery from PCL/Chitosan multilayer coatings for metallic implants,. ACS Omega . 7(27):23096.
Rajnak, M, Franko M, Paulovicova K, Karpets M, Parekh K, Upadhyay R, Kurimsky J, Dolnik B, Cimbala R, Havran P, Timko M, Kopcansky P.  2022.  Effect of ferrofluid magnetization on transformer temperature rise. Journal of Physics D: Applied Physics. 55(34)
Karpets, M, Rajnak M, Petrenko VI, Gapon I, Avdeev M, Bulavin L, Timko M, Kopcansky P.  2022.  Electric field-induced assembly of magnetic nanoparticles from dielectric ferrofluids on planar interface. Journal of Molecular Liquids. 362(119773)
Nunes, MJ, Moura JJG, Noronha JP, Branco LC, Samhan-Arias A, Sousa JP, Rouco C, Cordas C.  2022.  Evaluation of Sweat Sampling Procedures for Human Stress Biomarkers Detection. Analytica. 3:178–194.
Ramos, AP, Isufi B, Marreiros R, Marchão C.  2022.  Hybrid use of HPFRC in Slab-Column Connections under Cyclic Laterial Loading. fib Congress 2022, Oslo. , Oslocyclicoslo.pdf
Messias, S, Paz V, Cruz H, Rangel CM, Branco LC, Machado RAS.  2022.  Imidazolium and picoline-based electrolytes for electrochemical reduction of CO2 at high pressure. Energy Advances. 1(5):277-286.
Ramou, E, Palma SICJ, Roque ACA.  2022.  Nanoscale Events on Cyanobiphenyl-Based Self-Assembled Droplets Triggered by Gas Analytes. ACS Applied Materials and Interfaces. 14(4):6261-6273.PDF
Haque, S, Alexandre M, Baretzky C, Rossi D, Rossi FD, Vicente AT, Brunetti F, Águas H, Ferreira RAS, Fortunato E, Maur MAD, Wurfel U, Martins R, Mendes MJ.  2022.  Photonic-Structured Perovskite Solar Cells: Detailed Optoelectronic Analysis. ACS Photonics. 9(7):2408–2421.
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