Export 4172 results:
Sort by: Author Title Type [ Year  (Desc)]
2021
Isufi, B, Marreiros R, Ramos AP, Lúcio V.  2021.  Seismic behaviour of slab – column connections with various punching shear enhancement methods, 14-16 June 2021. fib Symposium 2021. , Lisbon
Silva, MA, Portela PC, Salgueiro CA.  2021.  Rational design of electron/proton transfer mechanisms in the exoelectrogenic bacteria Geobacter sulfurreducens, 07. Biochemical Journal. 478:2871-2887., Number 14 AbstractWebsite

{The redox potential values of cytochromes can be modulated by the protonation/deprotonation of neighbor groups (redox-Bohr effect), a mechanism that permits the proteins to couple electron/proton transfer. In the respiratory chains, this effect is particularly relevant if observed in the physiological pH range, as it may contribute to the electrochemical gradient for ATP synthesis. A constitutively produced family of five triheme cytochromes (PpcA−E) from the bacterium Geobacter sulfurreducens plays a crucial role in extracellular electron transfer, a hallmark that permits this bacterium to be explored for several biotechnological applications. Two members of this family (PpcA and PpcD) couple electron/proton transfer in the physiological pH range, a feature not shared with PpcB and PpcE. That ability is crucial for G. sulfurreducens’ growth in Fe(III)-reducing habitats since extra contributors to the electrochemical gradient are needed. It was postulated that the redox-Bohr effect is determined by the nature of residue 6, a leucine in PpcA/PpcD and a phenylalanine in PpcB/PpcE. To confirm this hypothesis, Phe6 was replaced by leucine in PpcB and PpcE. The functional properties of these mutants were investigated by NMR and UV–visible spectroscopy to assess their capability to couple electron/proton transfer in the physiological pH range. The results obtained showed that the mutants have an increased redox-Bohr effect and are now capable of coupling electron/proton transfer. This confirms the determinant role of the nature of residue 6 in the modulation of the redox-Bohr effect in this family of cytochromes, opening routes to engineer Geobacter cells with improved biomass production.}

Henriques, JT.  2021.  1D Fiber-shaped supercapacitors. FCT NOVA.
Mendes, DNDL, Gaspar A, Ferreira I, Mota JPB, Ribeiro RPPL.  2021.  3D-printed hybrid zeolitic/carbonaceous electrically conductive adsorbent structures. Chemical Engineering Research and Design. 174:442-453.
Pina, AS, Batalha IL, Dias AMGC, Roque ACA.  2021.  Affinity tags in protein purification and peptide enrichment: An overview, in Protein Downstream Processing: Design, Development, and Application of High and Low-Resolution Methods. Methods in Molecular Biology. :107-132.: Springer-Humana Press
Fernandes, CSM, Pina AS, Roque ACA.  2021.  Affinity-triggered hydrogels: Developments and prospects in biomaterials science. Biomaterials. 268:120563.
Gavinho, SR, Graça MP, Prezas P, Borges JB, Silva JC, Pires E, Armês H, Coucelo J.  2021.  Antibacterial bioglass in dental implants: a canine clinical study. European Journal of Public Health. 31(Supplement_2):ckab120.006. AbstractWebsite

Background
Peri-implantitis is considered the most challenging biological complication in implantology, as untreated disease can progress and result in implant loss. Therefore, disease prevention is crucial in daily clinical practice. It has been reported that the use of bioactive glass, as an implant coating, can stimulate tissue integration and accelerate tissue regeneration. Besides these properties, it is possible to promote bacterial activity by inserting silver into the bioglass

Methods
Bioglass with composition 45S5 was synthesised by the fusion method, replacing the amount of Na2CO3 by AgNO3 (BG 2% wt). The implants were resealed by the CoBlast® technique. Clinical cases with pathology of the mandible/maxilla were selected and implants dimensioned for the canine bone structure were applied.

Results
Three months after implantation, imaging exams, namely CT scans, showed no signs of early rejection by septic or cytotoxic loss. No decrease or loss of peri-implant bone was observed. In all cases the implants remained without signs of instability, and with sufficient support for the application of the exo-prosthesis or dental crown. The results of histological analysis showed no signs of infection or osteolysis. The zone of peri-implant fibrosis was not observable in the samples, showing a good evolution in implant osteointegration.

Conclusions
The results show promising evidences for the use of this biomaterial as a coating, since aseptic rejection, later on, and that related to the shape and biomaterials used in the implant's design, usually begins during the first 3 months.

Mariz, BP, Carvalho S, Batalha IL, Pina AS.  2021.  Artificial enzymes bringing together computational design and directed evolution. Organic & Biomolecular Chemistry. 19(9):1915-1925.
Duarte, VR, Rodrigues TA, Machado MA.  2021.  Benchmarking of Nondestructive Testing for Additive Manufacturing. 3D Printing and Additive Manufacturing. AbstractWebsite

Defect detection in additive manufacturing (AM) is of paramount importance to improve the reliability of products. Nondestructive testing is not yet widely used for defect detection. The main challenges are a lack of standards and methods, the types and location of defects, and the complex geometry of many parts. During selective laser melting (SLM), several types of defects can occur such as porosity, cracking, and lack of fusion. In this study, several nondestructive tests were conducted in a highly complex shaped part in AISI 316L stainless steel with real defects manufactured by SLM. Two additional artificial defects (one horizontal and one flat bottom hole) were produced and the defect detectability was evaluated. The techniques used were as follows: dye penetrant, infrared thermography, immersion ultrasonic, eddy current, and X-ray microcomputed tomography to assess different types of defects in the as-built part. We conclude that no single technique can detect every type of defect, although multiple techniques provide complementary and redundant information to critically evaluate the integrity of the parts. This approach is fundamental for improving the reliability of defect detection, which will help expand the potential for using AM to produce parts for critical structural applications.

Ramanaiaha, SV, Cordas CM, Matias SC, Reddyd MV, Leitão JH, Fonseca LP.  2021.  Bioelectricity generation using long-term operated biocathode: RFLP based microbial diversity analysis. Biotechnology Reports. 32:e00693.
PEREIRA, JOÃOFILIPESOUSA.  2021.  CARATERIZAÇÃO DE UMA MISTURA COMERCIAL DE UM MATERIAL CIMENTÍCIO DE ULTRAELEVADO DESEMPENHO. Faculty of Engineering of the University of Porto. (Sandra Nunes, Ed.)., Portotese_final_final_signed.pdf
C.M., C, J.J.G. M, A. E, R. M.  2021.  Carbon dioxide utilisation - bioelectrochemical approaches. Enzymes for Solving Humankind's Problems, Moura J.J.G., Moura I., Maia L.B. (eds). :83-108.
L.B., M, I. M, J.J.G. M.  2021.  Carbon dioxide utilisation - the formate route. Enzymes for Solving Humankind's Problems, Moura J.J.G., Moura I., Maia L.B. (eds). :29-81.: Springerco2_utilisation-formate_formation-2021.pdf
Faria, J, Dionísio B, Soares I, Baptista AC, Marques AC, Gonçalves L, Bettencourt A, Baleizão C, Ferreira I.  2021.  Cellulose acetate fibres loaded with daptomycin for metal implant coatings. Carbohydrate polymers. :118733. AbstractWebsite

Multifunctional polymeric coatings containing drug delivery vehicles can play a key role in preventing/reducing biofilm formation on implant surfaces. Their requirements are biocompatibility, good adhesion, and controllable drug release. Although cellulose acetate (CA) films and membranes are widely studied for scaffolding, their applications as a protective coating and drug delivery vehicle for metal implants are scarce. The reason is that adhesion to stainless steel (SS) substrates is non-trivial. Grinding SS substrates enhances the adhesion of dip-coated CA films while the adhesion of electrospun CA membranes is improved by an electrosprayed chitosan intermediate layer. PMMA microcapsules containing daptomycin have been successfully incorporated into CA films and fibres. The released drug concentration of 3 x10-3 mg/mL after 120 minutes was confirmed from the peak luminescence intensity under UV radiation of simulated body fluid (SBF) after immersion of the fibres.

Shlapa, Yu.; Timashkov, VSGMSKBI; K;.  2021.  Characterization of CeO2 Nanoparticles Synthesized by the Precipitation in the Water-Alcohol Solutions. New Journal of Chemistry.
Oliveira, RD, Mouquinho A, Centeno P, Alexandre M, Haque S, Martins R, Fortunato E, Águas H, Mendes MJ.  2021.  Colloidal Lithography for Photovoltaics: An Attractive Route for Light Management. Nanomaterials. 11(7):1665.
Silva, PES, da Rosa RR, Chagas R, Fernandes SN, Godinho MH.  2021.  Colourful Patterns in Cellulose-Based Liquid Crystals. Liquid Crystals and their Application. 21(4):53-60.412702article_2021_21_4_53-60.pdf
Santos, Â, Otero V, Vilarigues M.  2021.  Colours of pre-cinema projections: the evolution of hand-painted magic lantern glass slides' palette. Proceedings of the International Colour Association (AIC) Conference 2021. :659-664., Milan, Italy: International Colour Association (AIC) and Gruppo del Colore - Associazione Italiana Colore
Fernandes, H, Maia L, Ribeiro PM, J.J.G. M, Cerqueira NM.  2021.  The complete catalytic mechanism of Xanthine Oxidase: a computational study. Inorg Chem Front. 8:405.
Costa, FB, Machado MA, Bonfait GJ, Vieira P, Santos TG.  2021.  Continuous wave terahertz imaging for NDT: Fundamentals and experimental validation. Measurement. 172(108904) AbstractWebsite

Continuous wave terahertz (CW THz) imaging, is a variant of terahertz imaging that has been gaining scientific
and technological relevance in multiple areas. In this paper the fundamental phenomena of CW THz were
studied and a mathematical model was developed that successfully describes the Fabry–Perot interference for
such a system, opening the possibility for measurement of thicknesses and surface curvatures. The capabilities
of the system were tested using different types of defects, such as voids, water infiltrations and thin metallic
wires. The interactions between different materials, features and the radiation beam were numerically studied
using finite element method and the results agreed with the experiments. By comparing the results with other
Non-Destructive Testing methods, it was found that CW THz imaging is particularly interesting to image water
infiltrations and composite materials that incorporate conductive wires.

https://onlinelibrary.wiley.com/doi/abs/10.1002/adma.202170047.  2021.  Cover image Advanced Material Journal.
Santos, Â, Rodrigues B, Otero V, Vilarigues M.  2021.  "Defining the first preventive conservation guidelines for hand-painted magic lantern glass slides". Conservar Património. Santos et al_2021.pdf
Soares, PIP, Romão J, Matos R, Silva JC, Borges JP.  2021.  Design and engineering of magneto-responsive devices for cancer theranostics: Nano to macro perspective. Progress in Materials Science. 116:100742. AbstractWebsite

Design, research, and development of new and improved smart multifunctional devices is one of the main topics in the advanced functional materials agenda for the next decade. Smart materials that can be triggered by external stimuli are seen with high potential for innovative treatments and improved drug delivery systems by regulatory agencies like the FDA and EMA. The incorporation of magnetic nanostructures into complex systems produces multifunctional devices that can be spatiotemporally controlled by an external magnetic field. These magneto-responsive devices can be used for a multitude of biomedical applications, from diagnostic to the treatment of tumors, and are actively being developed and tested for cancer theranostics. Herein, we review the development of magneto-responsive devices for cancer theranostics, starting from the most straightforward architecture, single nanoparticles. We give some theoretical concepts about the design and production of such systems while providing a critical review of applications in clinical practice. Naturally, the review evolves to more complex architectures, from one-dimensional to three-dimensional magneto-responsive systems, demonstrating higher complexity and multifunctionality, and consequently, higher interest for clinical practice. The review ends with the main challenges in the design and engineering of magneto-responsive devices for cancer theranostics and future trends in this biomedical field.