Export 4181 results:
Sort by: Author Title Type [ Year  (Desc)]
2005
Ortigueira, M.  2005.  Fractional Differences Integral Representation and its use to define Fractional Differintegrations, August. the ENOC-2005, Fifth EUROMECH Nonlinear Dynamics Conference. Abstract
n/a
Ortigueira, M.  2005.  Fractional Differences Integral Representation and its use to define Fractional Differintegrations, August. the ENOC-2005, Fifth EUROMECH Nonlinear Dynamics Conference. Abstract

n/a

Ortigueira, M.  2005.  A new look at the differintegration definition, August. ENOC-2005, Fifth EUROMECH Nonlinear Dynamics Conference. Abstract
n/a
Ortigueira, M.  2005.  A new look at the differintegration definition, August. ENOC-2005, Fifth EUROMECH Nonlinear Dynamics Conference. Abstract

n/a

More, C, Asso M, Roger G, Guigliarelli B, Caldeira J, Moura J, Bertrand P.  2005.  Study of the spin-spin interactions between the metal centers of Desulfovibrio gigas aldehyde oxidoreductase: identification of the reducible sites of the [2Fe-2S]1+,2+ clusters, Aug 30. Biochemistry. 44:11628-35., Number 34 AbstractWebsite

The aldehyde oxidoreductase from Desulfovibrio gigas belongs to the family of molybdenum hydroxylases. Besides a molybdenum cofactor which constitutes their active site, these enzymes contain two [2Fe-2S](2+,1+) clusters which are believed to transfer the electrons provided by the substrate to an acceptor which is either a FAD group or an electron-transferring protein. When the three metal centers of D. gigas AOR are simultaneously paramagnetic, splittings due to intercenter spin-spin interactions are visible when the EPR spectra are recorded at low temperatures. By studying quantitatively these interactions with a model based on the X-ray crystal structure, which takes into consideration the interactions between the magnetic moments carried by all the metal sites of the system, it is possible to determine the location of the reducible sites of the [2Fe-2S] clusters. When combined with the electron-transfer pathways proposed on the basis of the X-ray crystal structure, the results provide a detailed description of the electron-transfer system of D. gigas AOR.

Palma, PN, Lagoutte B, Krippahl L, Moura JJ, Guerlesquin F.  2005.  Synechocystis ferredoxin/ferredoxin-NADP(+)-reductase/NADP+ complex: Structural model obtained by NMR-restrained docking, Aug 29. FEBS Lett. 579:4585-90., Number 21 AbstractWebsite

Ferredoxin (Fd) and ferredoxin-NADP(+)-reductase (FNR) are two terminal physiological partners of the photosynthetic electron transport chain. Based on a nuclear magnetic resonance (NMR)-restrained-docking approach, two alternative structural models of the Fd-FNR complex in the presence of NADP+ are proposed. The protein docking simulations were performed with the software BiGGER. NMR titration revealed a 1:1 stoichiometry for the complex and allowed the mapping of the interacting residues at the surface of Fd. The NMR chemical shifts were encoded into distance constraints and used with theoretically calculated electronic coupling between the redox cofactors to propose experimentally validated docked complexes.

Simões, S, Seixas J, Huppes G.  2005.   tangled web: assessing overlaps between energy and environmental policy instruments in place along electricity systems, 30 May - 3 June. ECEEE - European Council for an Energy Efficient Economy 2005 Summer Study. , Mandelieu, France
Pina, J, de Melo JS, Pina F, Lodeiro C, Lima JC, Parola AJ, Soriano C, Clares MP, Albelda MT, Aucejo R, Garcia-Espana E.  2005.  Spectroscopy and coordination chemistry bisnaphthalene-bisphenanthroline ligand of a new displaying a sensing ability for metal cations, 2005. Inorganic Chemistry. 44:7449-7458. AbstractWebsite

A new fluorescent macrocyclic structure (0) bearing two naphthalene units at both ends of a cyclic polyaminic chain containing two phenanthroline units was investigated with potentiometric and fluorescence (steady-state and time-resolved) techniques. The fluorescence emission spectra show the simultaneous presence of three bands: a short wavelength emission band (naphthalene monomer), a middle emission band (phenanthroline emission), and a long-wavelength band. All three bands were found to be dependent on the protonation state of the macrocyclic unit (including the polyaminic and phenanthroline structures). The existence of the long-wavelength emission band is discussed and is shown to imply that a bending movement involving the two phenanthroline units leads to excimer formation. This is determined by comparison with the excimer emission formed by intermolecular association of 1,10-phenanthroline. With ligand L1, excimer formation occurs only at pH values above 4. At very acidic pH values, the protonation of the polyamine bridges is extensive leading to a rigidity of the system that precludes the bending movement. The interaction with metal cations Zn(II) and Cu(II) was also investigated. Excimer formation is, in these situations, increased with Zn(II) and decreased with Cu(II). The long-emission band is shown to present a different wavelength maximum, depending on the metal, which can be considered as a characteristic to validate the use of ligand L1 as a sensor for a given metal.

Galindo, F, Lima JC, Luis SV, Melo MJ, Parola AJ, Pina F.  2005.  Water/humidity and ammonia sensor, based on a polymer hydrogel matrix containing a fluorescent flavylium compound, 2005. Journal of Materials Chemistry. 15:2840-2847. AbstractWebsite

Flavylium compounds can conveniently be encapsulated in water permeable cross-linked poly(2-hydroxyethyl methacrylate) ( PHEMA) polymer hydrogel matrices. The polymer is also permeable to gases, for example ammonia and hydrogen chloride. The ability of the polymer to concentrate water from the surrounding atmosphere was demonstrated. The absorption and emission spectra of the encapsulated flavylium compounds are very dependent on the pH, and by consequence ammonia ( or hydrogen chloride) can be easily detected. The intensity of the fluorescence emission of the flavylium cation (AH+ species obtained in acidic media) is very dependent on the water content due to the efficient excited state proton transfer involving the AH(+)* excited state and water. The combination of flavylium emission sensitivity to water and ability of the polymer to concentrate water from the surrounding atmosphere, confers this material potential utility as a humidity sensor with high sensitivity.

BRITO PALMA, L, Coito FV, NEVES DA SILVA R.  2005.   Diagnosis of parametric faults based on identification and statistical methods. Decision and Control, 2005 and 2005 European Control Conference. CDC-ECC’05. 44th IEEE Conference on. :3838–3843.: IEEE. Abstract

n/a

Ortigueira, M.  2005.   Processamento Digital de Sinais. , September. Edição do Serviço de Educação e Bolsas da Fundação Calouste Gulbenkian. : Fundação Calouste Gulbenkian AbstractWebsite

n/a

Coito, F, Lemos J.  2005.  Adaptive Optimization with Constraints: Convergence and oscillatory behaviour. Pattern Recognition and Image Analysis. (Springer Berlin/Heidelberg):335–366. Abstract

n/a

Ricardo, CN, Gerald JA, Ortigueira M.  2005.  Analysis of New Quasi-Orthogonal BCH-Derived Sequences for CDMA Applications. XX Conference on Design of Circuits and Integrated Systems (DCIS'05). Abstract

n/a

Salgueiro, CA, Morgado L, Fonseca B, Lamosa P, Catarino T, Turner DL, Louro RO.  2005.  Binding of ligands originates small perturbations on the microscopic thermodynamic properties of a multicentre redox protein. FEBS Journal. 272(9):2251-2260. AbstractWebsite

NMR and visible spectroscopy coupled to redox measurements were used to determine the equilibrium thermodynamic properties of the four haems in cytochrome c3 under conditions in which the protein was bound to ligands, the small anion phosphate and the protein rubredoxin with the iron in the active site replaced by zinc. Comparison of these results with data for the isolated cytochrome shows that binding of ligands causes only small changes in the reduction potentials of the haems and their pairwise interactions, and also that the redox-sensitive acid–base centre responsible for the redox–Bohr effect is essentially unaffected. Although neither of the ligands tested is a physiological partner of cytochrome c3, the small changes observed for the thermodynamic properties of cytochrome c3 bound to these ligands vs. the unbound state, indicate that the thermodynamic properties measured for the isolated protein are relevant for a physiological interpretation of the role of this cytochrome in the bioenergetic metabolism of Desulfovibrio.

Palma, LB, Coito FV, da Silva RN.  2005.  Combined approach to fault diagnosis based on principal components and influence matrix. Intelligent Signal Processing, 2005 IEEE International Workshop on. :171–176.: IEEE. Abstract

n/a

Pinto, I, Alves LB, Ortigueira MD, B AG.  2005.  ECG Wave Detection and Delineation with Wavelets. Computational Intelligence in Medicine and Healthcare Conference. : Biopattern. Abstract

n/a

Pessanha, M, Rothery EL, Louro RO, Turner DL, Miles CS, Reid GA, Chapman SK, Xavier AV, Salgueiro CA.  2005.  Elucidation of the Functional Redox Behavior of Fumarate Reductase from Shewanella frigidimarina by NMR. Annals Magnetic Resonance. 4(1/2):24-28. AbstractWebsite

NMR spectroscopy has been applied with great success to study electron transfer proteins
with multiple redox centers. This study aimed to elucidate the redox behavior the enzyme fumarate
reductase from Shewanella frigidimarina and particularly to reveal the electron transfer mechanism
from the N-terminal domain to the active center. We developed a new strategy encompassing the
acquisition of 1H-EXSY bidimensional spectra for observation of chemical exchange connectivities in
partially oxidized samples of fcc3, estimation of the paramagnetic chemical shifts expected for the
heme substituents and their comparison with NMR spectra obtained in the fully oxidized protein. This
study allowed obtaining the order of oxidation of the different groups (II-I-III, IV) and gave insights of
the functional mechanisms that allow fcc3 to efficiently transfer electrons from the N-terminal domain
to the active center.

Gonçalves, LL, Almeida MG, Lampreia J, Moura JJG, Moura I.  2005.  Prediction of Signal Peptides and Signal Anchors of Cytocrome c Nitrite Reductase from Desulfovibrio desulfuricans ATCC 27774 Using Bioinformatic Tools. Essays in Bioinformatics. Vol. 368(D.S. Moss, S. Jelaska, S. Pongor, Ed.).:203-208.: IOS Press (Amsterdam) Abstract

n/a

Palma, LB, Coito FV, da Silva RN.  2005.  Process fault diagnosis approach based on neural observers. Emerging Technologies and Factory Automation, 2005. ETFA 2005. 10th IEEE Conference on. 1:4–pp.: IEEE. Abstract

n/a

Filipe, SR, Tomasz A, Ligoxygakis P.  2005.  Requirements of peptidoglycan structure allowing detection by the Drosophila Toll pathway. EMBO Reports. 6:327-333.
Coito, F, Almeida P, Palma LB.  2005.  SMCRVI-a Labview/Matlab based tool for remote monitoring and control. Emerging Technologies and Factory Automation, 2005. ETFA 2005. 10th IEEE Conference on. 2:6–pp.: IEEE. Abstract

n/a

Coito, F, Lemos JM, Alves SS.  2005.  Stochastic Extremum Seeking in the Presence of Constraints. World Congress. 16:266–266., Number 1. Abstract

n/a

Coito, F, Lemos J.  2005.  Adaptive Optimization with Constraints: Convergence and oscillatory behaviour. Pattern Recognition and Image Analysis. :335–366.: Springer Berlin/Heidelberg Abstract

n/a

Ricardo, CN, Gerald JA, Ortigueira M.  2005.  Analysis of New Quasi-Orthogonal BCH-Derived Sequences for CDMA Applications. XX Conference on Design of Circuits and Integrated Systems (DCIS'05). Abstract
n/a
Giestas, L, Folgosa F, Lima JC, Parola AJ, Pina F.  2005.  Bio-inspired multistate networks responsive to light, pH and thermal inputs - An example of a multistate system operating through different algorithms. European Journal of Organic Chemistry. :4187-4200., Number 19 Abstract
n/a
loading