B.A, S, M. E, L. B, R.C.C. M.
2013.
Preparation method and thermal properties of samarium andeuropium-doped alumino-phosphate glasses. Materials Science and Engineering: B.
AbstractThe present work investigates alumino-phosphate glasses from Li2O–BaO–Al2O3–La2O3–P2O5 system containing Sm3+ and Eu3+ ions, prepared by two different ways: a wet raw materials mixing route followed by evaporation and melt-quenching, and by remelting of shards. The linear thermal expansion coefficient measured by dilatometry is identical for both rare-earth-doped phosphate glasses. Comparatively to undoped phosphate glass the linear thermal expansion coefficient increases with 2 × 10−7 K−1 when dopants are added. The characteristic temperatures very slowly decrease but can be considered constant with atomic weight, atomic number and f electrons number of the doping ions in the case of Tg (vitreous transition temperature) and Tsr (high annealing temperature) but slowly increase in the case of Tir (low annealing temperature–strain point) and very slowly increase, being practically constant in the case of TD (dilatometric softening temperature). Comparatively to undoped phosphate glass the characteristic temperatures of Sm and Eu-doped glasses present lower values. The higher values of electrical conductance for both doped glasses, comparatively to usual soda-lime-silicate glass, indicate a slightly reduced stability against water. The viscosity measurements, showed a quasi-linear variation with temperature the mean square deviation (R2) being ranged between 0.872% and 0.996%. The viscosity of doped glasses comparatively to the undoped one is lower at the same temperature. Thermogravimetric analysis did not show notable mass change for any of doped samples. DSC curves for both rare-earth-doped phosphate glasses, as bulk and powdered samples, showed Tg values in the range 435–450 °C. Bulk samples exhibited a very weak exothermic peak at about 685 °C, while powdered samples showed two weak exothermic peaks at about 555 °C and 685 °C due to devitrification of the glasses. Using designed melting and annealing programs, the doped glasses were improved regarding bubbles and cords content and strain elimination.
Baumann, M.
2013.
Prospective system analysis of stationary battery systems under the frame of Constructive Technology Assessment. Enterprise and Work Innovation Studies. 9(9):9-27.
AbstractThe ongoing German energy transition causes a higher demand for reliable energy storage in the future. This increasing demand for sustainable, cheap, safe and efficient energy storage systems has caused a stronger public debate about the potential benefits of grid battery storage according to sustainability. This circumstance led to the preposition that there is a need for the development of a proper ex-ante assessment strategy to support technology uptake. The developed approach represents a framework for prospective system analysis (PSA) using the heuristics of constructive technology assessment to identify consequences, application possibilities or threats in the technological trajectory of grid battery storage. Within this framework PSA is used to quantitatively assess economic, environmental and social aspects along the entire life cycle of electrochemical energy storage technologies in order to identify hotspots according to sustainability. The Analytic Hierarchic Process (AHP) supports multiple methods in data collection and enables the analyst to combine results from PSA with qualitative actor notions about technology according to the “world” where it is embodied. In this sense AHP enables to achieve an optimum construct of technology from a stakeholder view point. The developed approach represents an efficient research strategy to shape technology in a sustainable way in frame of „Responsible Research and Innovation“.
Lanca, T, Costa MF, Goncalves-Sousa N, Rei M, Grosso AR, Penido C, Silva-Santos B.
2013.
Protective role of the inflammatory CCR2/CCL2 chemokine pathway through recruitment of type 1 cytotoxic γδ T lymphocytes to tumor beds. J Immunol. 190:6673–6680., Number 12
AbstractTumor-infiltrating lymphocytes (TILs) are important prognostic factors in cancer progression and key players in cancer immunotherapy. Although γδ T lymphocytes can target a diversity of tumor cell types, their clinical manipulation is hampered by our limited knowledge of the molecular cues that determine γδ T cell migration toward tumors in vivo. In this study we set out to identify the chemotactic signals that orchestrate tumor infiltration by γδ T cells. We have used the preclinical transplantable B16 melanoma model to profile chemokines in tumor lesions and assess their impact on γδ TIL recruitment in vivo. We show that the inflammatory chemokine CCL2 and its receptor CCR2 are necessary for the accumulation of γδ TILs in B16 lesions, where they produce IFN-γ and display potent cytotoxic functions. Moreover, CCL2 directed γδ T cell migration in vitro toward tumor extracts, which was abrogated by anti-CCL2 neutralizing Abs. Strikingly, the lack of γδ TILs in TCRδ-deficient but also in CCR2-deficient mice enhanced tumor growth in vivo, thus revealing an unanticipated protective role for CCR2/CCL2 through the recruitment of γδ T cells. Importantly, we demonstrate that human Vδ1 T cells, but not their Vδ2 counterparts, express CCR2 and migrate to CCL2, whose expression is strongly deregulated in multiple human tumors of diverse origin, such as lung, prostate, liver, or breast cancer. This work identifies a novel protective role for CCL2/CCR2 in the tumor microenvironment, while opening new perspectives for modulation of human Vδ1 T cells in cancer immunotherapy.
Martins, Ahnood, Arman, Correia, Nuno, Pereira, Barros, R., Barquinha, Costa, Ferreira, Nathan, Arokia, Fortunato E.
2013.
Recyclable, Flexible, Low-Power Oxide Electronics. Advanced Functional Materials. 23(17):2153-2161.
Araújo, A, Barros R, Mateus T, Gaspar D, Neves N, Vicente A, Filonovich SA, Barquinha P, Fortunato E, Ferraria AM, do Rego ABM, Bicho A, Águas H, Martins R.
2013.
Role of a disperse carbon interlayer on the performances of tandem a-Si solar cells. Science and Technology of Advanced Materials. 14(4)
Morgado, L, Dantas JM, Simões T, Londer YY, Pokkuluri PR, Salgueiro CA.
2013.
Role of Met58 in the regulation of electron/proton transfer in trihaem cytochrome PpcA from Geobacter sulfurreducens. Bioscience Reports. 33(1):11-22.
AbstractThe bacterium Gs (Geobacter sulfurreducens) is capable of oxidizing a large variety of compounds relaying electrons out of the cytoplasm and across the membranes in a process designated as extracellular electron transfer. The trihaem cytochrome PpcA is highly abundant in Gs and is most probably the reservoir of electrons destined for the outer surface. In addition to its role in electron transfer pathways, we have previously shown that this protein could perform e-/H+ energy transduction. This mechanism is achieved by selecting the specific redox states that the protein can access during the redox cycle and might be related to the formation of proton electrochemical potential gradient across the periplasmic membrane. The regulatory role of haem III in the functional mechanism of PpcA was probed by replacing Met58, a residue that controls the solvent accessibility of haem III, with serine, aspartic acid, asparagine or lysine. The data obtained from the mutants showed that the preferred e-/H+ transfer pathway observed for PpcA is strongly dependent on the reduction potential of haem III. It is striking to note that one residue can fine tune the redox states that can be accessed by the trihaem cytochrome enough to alter the functional pathways.
Amado, M, Rodrigues P, Poggi F, Freitas J.
2013.
Solar Urban Planning to EU 20-20-20 Targets. Portugal SB 13 - CONTRIBUTION OF SUSTAINABLE BUILDING TO MEET EU 20-20-20 TARGETS. :697-708., Guimaraes, PT: iiSBE PORTUGAL
Dantas, JM, Morgado L, Pokkuluri PR, Turner DL, Salgueiro CA.
2013.
Solution structure of a mutant of the triheme cytochrome PpcA from Geobacter sulfurreducens sheds light on the role of the conserved aromatic residue F15. Biochimica et Biophysica Acta (BBA) - Bioenergetics. 1827(4):484-492.
AbstractExtracellular electron transfer is one of the physiological hallmarks of Geobacteraceae. Most of the Geobacter species encode for more than 100 c-type cytochromes which are, in general, poorly conserved between individual species. An exception to this is the PpcA family of periplasmic triheme c-type cytochromes, which are the most abundant proteins in these bacteria. The functional characterization of PpcA showed that it has the necessary properties to couple electron/proton transfer, a fundamental step for ATP synthesis. The detailed thermodynamic characterization of a PpcA mutant, in which the strictly conserved residue phenylalanine 15 was replaced by leucine, showed that the global redox network of cooperativities among heme groups is altered, preventing the mutant from performing a concerted electron/proton transfer. In this work, we determined the solution structure of PpcA F15L mutant in the fully reduced state using NMR spectroscopy by producing 15N-labeled protein. In addition, pH-dependent conformational changes were mapped onto the structure. The mutant structure obtained is well defined, with an average pairwise root-mean-square deviation of 0.36 Å for the backbone atoms and 1.14 Å for all heavy atoms. Comparison between the mutant and wild-type structures elucidated the contribution of phenylalanine 15 in the modulation of the functional properties of PpcA.
Borlido, L, Moura L, Azevedo AM, Roque ACA, Aires‐Barros MR, Farinha JPS.
2013.
Stimuli‐Responsive magnetic nanoparticles for monoclonal antibody purification. Biotechnology Journal. 8(6):709–717.
AbstractMonoclonal antibodies (mAbs) are important therapeutic proteins. One of the challenges facing large-scale production of monoclonal antibodies is the capacity bottleneck in downstream processing, which can be circumvented by using magnetic stimuli-responsive polymer nanoparticles. In this work, stimuli-responsive magnetic particles composed of a magnetic poly(methyl methacrylate) core with a poly(N-isopropylacrylamide-co-acrylic acid) (P(NIPAM-co-AA)) shell cross-linked with N, N'-methylenebisacrylamide were prepared by miniemulsion polymerization. The particles were shown to have an average hydrodynamic diameter of 317 nm at 18°C, which decreased to 277 nm at 41°C due to the collapse of the thermo-responsive shell. The particles were superparamagnetic in behavior and exhibited a saturation magnetization of 12.6 emu/g. Subsequently, we evaluated the potential of these negatively charged stimuli-responsive magnetic particles in the purification of a monoclonal antibody from a diafiltered CHO cell culture supernatant by cation exchange. The adsorption of antibodies onto P(NIPAM-co-AA)-coated nanoparticles was highly selective and allowed for the recovery of approximately 94% of the mAb. Different elution strategies were employed providing highly pure mAb fractions with host cell protein (HCP) removal greater than 98%. By exploring the stimuli-responsive properties of the particles, shorter magnetic separation times were possible without significant differences in product yield and purity.
Ferreira, I, Baptista AC, Leitão JP, Soares J, Fortunato E, Martins R, Borges JP.
2013.
Strongly Photosensitive and Fluorescent F8T2 Electrospun Fibers. Macromol Mater Eng. 298(2):174-180., Number 2
AbstractElectrospun fibers of poly[(9,9-dioctylfluorenyl-2,7-diyl)-co-bithiophene] (F8T2) with exceptional electro-optical performance are obtained. The I/T characteristics measured in fibers with 7–15 µm diameter and 1 mm length show a semiconductor behavior; their thermal activation energy is 0.5 eV and the dark conductivity at RT is 5 × 10−9 (Ω cm)−1. Besides exhibiting a photosensitivity of about 60 under white light illumination with a light power intensity of 25 mW · cm−2, the fibers also attain RT photoluminescence in the cyan, yellow, and red wavelength range under ultraviolet, blue, and green light excitation, respectively. Optical microscope images of F8T2 reveal homogeneous electrospun fibers, which are in good agreement with the uniformly radial fluorescence observed.
Alves, C, Rodrigues, L. C., Andrade, J. R., Pawlicka, A., Pereira, Martins, Fortunato, Silva MM.
2013.
Study and Characterization of a Novel Polymer Electrolyte Based on Agar Doped with Magnesium Triflate. Molecular Crystals and Liquid Crystals. 570(1):1-11.
Amado, M, Lucas V, Ribeiro M.
2013.
Sustainable Construction: Value of Certification. Proc. of the Intl. Conf. on Advances in Civil, Structural and Environmental Engineering-- ACSEE 2013. :180-187., Zurich, CH: Institute of Research Engineers and Doctors