Cordas, CM, Raleiras P, Auchère F, Moura I, Moura JJG.
2011.
Comparative electrochemical study of superoxide reductases, Dec 06. Eur. Biophys. J.. 41:209-215., Number 2
Abstract... CM Cordas (&) Á P . Raleiras Á F . Auche`re Á I. Moura Á JJG Moura ... de Quımica, Universidade Nova de Lisboa, 2859-516 Caparica, Portugal e-mail: cristina. cordas @dq.fct ... Present Address: P . Raleiras Department of Photochemistry and Molecular Science, PO Box 523, 75120 ...
Ramos, S, Moura JJ, Aureliano M.
2011.
Actin as a potential target for decavanadate, Dec. J Inorg Biochem. 104:1234-9., Number 12
AbstractATP prevents G-actin cysteine oxidation and vanadyl formation specifically induced by decavanadate, suggesting that the oxometalate-protein interaction is affected by the nucleotide. The ATP exchange rate is increased by 2-fold due to the presence of decavanadate when compared with control actin (3.1x10(-3) s(-1)), and an apparent dissociation constant (k(dapp)) of 227.4+/-25.7 muM and 112.3+/-8.7 muM was obtained in absence or presence of 20 muM V(10), respectively. Moreover, concentrations as low as 50 muM of decameric vanadate species (V(10)) increases the relative G-actin intrinsic fluorescence intensity by approximately 80% whereas for a 10-fold concentration of monomeric vanadate (V(1)) no effects were observed. Upon decavanadate titration, it was observed a linear increase in G-actin hydrophobic surface (2.6-fold), while no changes were detected for V(1) (0-200 muM). Taken together, three major ideas arise: i) ATP prevents decavanadate-induced G-actin cysteine oxidation and vanadate reduction; ii) decavanadate promotes actin conformational changes resulting on its inactivation, iii) decavanadate has an effect on actin ATP binding site. Once it is demonstrated that actin is a new potential target for decavanadate, being the ATP binding site a suitable site for decavanadate binding, it is proposed that some of the biological effects of vanadate can be, at least in part, explained by decavanadate interactions with actin.
Oliveira, J, Petrov V, Parola AJ, Pina F, Azevedo J, Teixeira N, Bras NF, Fernandes PA, Mateus N, Ramos MJ, de Freitas V.
2011.
Chemical Behavior of Methylpyranomalvidin-3-O-glucoside in Aqueous Solution Studied by NMR and UV-Visible Spectroscopy, 2011. Journal of Physical Chemistry B. 115:1538-1545.
AbstractIn the present work, the proton-transfer reactions of the methylpyranomalvidin-3-O-glucoside pigment in water with different pH values was studied by NMR and UV-visible spectroscopies. The results showed four equilibrium forms: the methylpyranomalvidin-3-O-glucoside cation, the neutral quinoidal base, the respective anionic quinoidal base, and a dianionic base unprotonated at the methyl group. According to the NMR data, it seems that for methylpyranomalvidin-3-O-glucoside besides the acid base equilibrium between the pyranoflavylium cation and the neutral quinoidal base, a new species is formed at pD 4.88-6.10. This is corroborated by the appearance of a new set of signals in the NMR spectrum that may be assigned to the formation of hemiketal/cis-chalcone species to a small extent. The two ionization constants (pK(a1) and pK(a2)) obtained by both methods (NMR and UV-visible) for methylpyranomalvidin-3-O-glucoside are in agreement (pK(a1) = 5.17 +/- 0.03; pK(a2) = 8.85 +/- 0.08; and pK(a1) = 4.57 +/- 0.07; pK(a2) = 8.23 +/- 0.04 obtained by NMR and UV-visible spectroscopies, respectively). Moreover, the fully dianionic unprotonated form (at the methyl group) of the methylpyranomalvidin-3-O-glucoside is converted slowly into a new structure that displays a yellow color at basic pH. On the basis of the results obtained through LC-MS and NMR, the proposed structure was found to correspond to the flavonol syringetin-3-glucoside.
Avo, J, Parola AJ, Lima JC, Pina F, Cunha-Silva L.
2011.
Phase transition thermochromism based on C-H acidity of 4-alkylflavylium compounds in Pluronic F-127, 2011. Journal of Materials Chemistry. 21:16628-16637.
AbstractIn moderately acidic water/ethanol solutions, 7-(naphthalen-2-ylmethyl)-5,6-dihydrobenzo[c]xanthen12-ium perchlorate shows C-H proton acidity giving rise to an ethylenic base species, instead of the hydration products of the typical flavylium network of chemical reactions, hemiketal, cis-chalcone and trans-chalcone. The kinetics of this acid-base process is much slower, k(obs)(s(-1)) = 3.5 x 10(-3) + 0.16[H(+)], than those commonly observed for O-H deprotonation. In the presence of the triblock copolymer Pluronic F-127, the ethylenic base is dramatically stabilized shifting the pK(a) from 1.35 (in ethanol : water (1 : 1) to -0.35. Taking profit from the well-described temperature dependence of this polymer, a phase transition thermochromic system was achieved. The system was cycled between 5 and 35 degrees C with negligible changes in absorbance after 20 cycles.
Lopes, T, Amado M, Correia de Freitas J.
2011.
Green Build Design Process, 18 Oct. SB11 World Sustainable Building Conference. , Helsinki
AbstractAll the buildings promote impacts on the environmental and in human health who impose more attention in the evaluation of sustainable performance in building design. The difficulty to identify the better design process to answer to all conflicting factors in special the economical and environmental performance impose the research of the issue. To assist the research in the way to find the best process to the promotion of design alternatives the life cycle analysis methodology is the more adapted the deal with all the three factors of sustainable development. The promotion of a new process to design phase of green build is the goal of this paper.
Amado, M, Lopes T, Correia de Freitas J.
2011.
Indicators to measure sustainability in urban developments, 18 Oct. SB11 World Sustainable Building Conference. , Helsinki
AbstractThe use of indicators to measure sustainability in urban development’s is the most efficient tool to help local authorities in the regulation of new and existing urban areas. The demographic grow in developing countries impose a utilization of a tool who make possible have a clear image of the process of land use change and the evaluation of the capacity of charge is the way to archive a effective sustainable development of the urban areas and regions. The selection of the correct indicators to apply to the process of land use transformation in Cabo Verde is the objective of the paper.
Amado, M, Ribeiro R.
2011.
Urban Sprawl promoted through Master Planning Process, 18 Oct. SB11 World Sustainable Building Conference. , Helsinki
AbstractThe urban sprawl phenomenon has been raise in the last three decades. In the same time all municipalities have adopted the methodology of the master planning to program the land use. In the same time the well-being in cities have decreased and the life quality of population is dreadful so is urgent the promotion of a new process to planning the transformation of existing urban areas and program new areas. The aim of this paper is the proposal of a new process to be adopted to the master planning.
Qian, X, Mester T, Morgado L, Arakawa T, Sharma ML, Inoue K, Joseph C, Salgueiro CA, Maroney MJ, Lovley DR.
2011.
Biochemical characterization of purified OmcS, a c-type cytochrome required for insoluble Fe(III) reduction in Geobacter sulfurreducens. Biochimica et Biophysica Acta (BBA) - Bioenergetics. 1807(4):404-412.
AbstractPrevious studies with Geobacter sulfurreducens have demonstrated that OmcS, an abundant c-type cytochrome that is only loosely bound to the outer surface, plays an important role in electron transfer to Fe(III) oxides as well as other extracellular electron acceptors. In order to further investigate the function of OmcS, it was purified from a strain that overproduces the protein. Purified OmcS had a molecular mass of 47 015 Da, and six low-spin bis-histidinyl hexacoordinated heme groups. Its midpoint redox potential was −212 mV. A thermal stability analysis showed that the cooperative melting of purified OmcS occurs in the range of 65–82 °C. Far UV circular dichroism spectroscopy indicated that the secondary structure of purified OmcS consists of about 10% α-helix and abundant disordered structures. Dithionite-reduced OmcS was able to transfer electrons to a variety of substrates of environmental importance including insoluble Fe(III) oxide, Mn(IV) oxide and humic substances. Stopped flow analysis revealed that the reaction rate of OmcS oxidation has a hyperbolic dependence on the concentration of the studied substrates. A ten-fold faster reaction rate with anthraquinone-2,6-disulfonate (AQDS) (25.2 s− 1) was observed as compared to that with Fe(III) citrate (2.9 s− 1). The results, coupled with previous localization and gene deletion studies, suggest that OmcS is well-suited to play an important role in extracellular electron transfer.
Ganhão, A.
2011.
Construção Sustentável - Propostas de Melhoria da Eficiência Energética em Edíficios de Habitação. Faculdade de Ciências e Tecnologia. (
Amado, Miguel, Ed.)., Lisbon
AbstractCurrently, there is high energy consumption in the buildings sector, in Portugal, which implies
an obstacle to the accomplishment of purposes intrinsic to the assumptions of sustainable development
and construction.
Therefore, efforts should be made to allow the construction of energy efficient buildings,
which is based on the adoption of a set of passive and/or active techniques that strive to reduce the
energy consumption of buildings throughout its life cycle, while ensuring comfort for its occupants.
The main objective of this dissertation is to evaluate passive and active proposals for
improving energy efficiency in residential buildings, based on the calculation of energy savings
associated with air conditioning and the payback period. To this end it was established a case study,
using as a base model a building unit of a multifamily building. The initial assessment of energetic
performance of this case study and its comparison after the implementation of improvement strategies
was done through a dynamic analysis using the EnergyPlus software.
The following solutions were evaluated: application of thermal insulation inside the cavity
wall, application of ETICS, more efficient glazing solutions, changing the building's solar orientation,
fixed shading devices application, definition of a pattern of night ventilation in the summer and use of
more efficient electrical equipment and lighting.
It was found that the use of these systems improves the energy efficiency of buildings, such as
the case study, despite of having different payback periods.