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2011
Gonçalves, N.  2011.  Planeamento Sustentável – Qual o modelo? Faculdade de Ciências e Tecnologia. (Amado, Miguel, Ed.)., Lisbon
Borlido, L, Azevedo AM, Roque ACA, Aires-Barros MR.  2011.  Potential of boronic acid functionalized magnetic particles in the adsorption of human antibodies under mammalian cell culture conditions. Journal of Chromatography A. 1218(43):7821-7827. AbstractWebsite

In this work, we systematically evaluated the potential of using boronic acid functionalized magnetic particles in the capturing of human immunoglobulin G under typical mammalian cell culture conditions. For comparison, Protein A coated magnetic particles were also used. The binding pH was found to significantly influence the adsorption isotherms of boronic acid particles with the higher capacities (0.216 g IgG/g support) being observed at pH 7.4. Comparatively, this value was 0.109 g IgG/g support, for Protein A particles under the same conditions. Both particles revealed very fast adsorption kinetics with more than 70% of the maximum binding capacity being achieved in a few seconds. The effect of glucose and lactate, which are known to interact with boronic acid, was evaluated. For glucose, the binding capacity was significantly influenced by the pH and decreased as pH increased. At pH 9.5, a 70% lower binding capacity was observed for glucose concentrations as low as 0.5 g/l. The effect of lactate was less pronounced and almost pH independent reaching at most 20% decrease in binding capacity. Nevertheless, the effect of both molecules was always lower at pH 7.4. The optimization of the elution conditions enabled complete recovery of bound IgG from boronic acid particles using 50mM Tris-HCl, 200 mM sorbitol, 200 mM NaCl at pH 8.5.

Teixeira, T.  2011.  Reabilitação Sustentável de Edifícios Industriais. Faculdade de Ciências e Tecnologia. (Amado, Miguel, Ed.)., Lisbon
Franco, R, Al-Karadaghi S, Ferreira G.  2011.  Resonance Raman Spectroscopic Examination of Ferrochelatase-Induced Porphyrin Distortion. Journal of Porphyrins and Phtalocyanines. 15(5-6):357-363.
Almeida, R, Ortigueira MD, Batista AG, Ktonas P.  2011.  Sleep Spindles: Decomposition, Parameterization and Applications. 19th IEEE Conference on Signal Processing and Communications Applications. Abstract

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de Almeida, SF, Grosso AR, Koch F, Fenouil R, Carvalho S, Andrade J, Levezinho H, Gut M, Eick D, Gut I, Andrau J-C, Ferrier P, Carmo-fonseca M.  2011.  Splicing enhances recruitment of methyltransferase HYPB/Setd2 and methylation of histone H3 Lys36.. Nature structural & molecular biology. 18:977–983., Number 9: Nature Publishing Group AbstractWebsite

Several lines of recent evidence support a role for chromatin in splicing regulation. Here, we show that splicing can also contribute to histone modification, which implies bidirectional communication between epigenetic mechanisms and RNA processing. Genome-wide analysis of histone methylation in human cell lines and mouse primary T cells reveals that intron-containing genes are preferentially marked with histone H3 Lys36 trimethylation (H3K36me3) relative to intronless genes. In intron-containing genes, H3K36me3 marking is proportional to transcriptional activity, whereas in intronless genes, H3K36me3 is always detected at much lower levels. Furthermore, splicing inhibition impairs recruitment of H3K36 methyltransferase HYPB (also known as Setd2) and reduces H3K36me3, whereas splicing activation has the opposite effect. Moreover, the increase of H3K36me3 correlates with the length of the first intron, consistent with the view that splicing enhances H3 methylation. We propose that splicing is mechanistically coupled to recruitment of HYPB/Setd2 to elongating RNA polymerase II.

Nunes, N, Araújo T, Gamboa H.  2011.  Two-Modes Cyclic Biosignal Clustering based on Time Series Analysis. Proceedings of Biosignals - International Conference on Bio-inspired Systems and Signal Processing (BIOSTEC 2011). , Rome, Italy
Atilano, ML, Yates J, Glittenberg M, Filipe* SR, Ligoxygakis* P.  2011.  Wall teichoic acids of Staphylococcus aureus limit recognition by the Drosophila Peptidoglycan Recognition Protein-SA to promote pathogenicity. PLoS Pathogens. 7:e1002421.
Oliveira, J, Petrov V, Parola JA, 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. Journal of Physical Chemistry B. 115:1538-1545., Number 6 AbstractWebsite
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Branco, LC, Serbanovic A, da Ponte MN, Afonso CAM.  2011.  Chiral Guanidinium Ionic Liquids for Asymmetric Dihydroxylation of Olefins with Recycling of the Catalytic System by Supercritical CO2. Acs Catalysis. 1:1408-1413., Number 10 AbstractWebsite
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Gordo, J, Avo J, Parola JA, Lima JC, Pereira A, Branco PS.  2011.  Convenient Synthesis of 3-Vinyl and 3-Styryl Coumarins. Organic Letters. 13:5112-5115., Number 19 Abstract
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Serra, AS, Jorge SR, Silveira CM, Moura JJG, Jubete E, Ochoteco E, Cabañero G, Grande H, Almeida MG.  2011.  Cooperative use of cytochrome cd1 nitrite reductase and its redox partner cytochrome c552 to improve the selectivity of nitrite biosensing. Analytica Chimica Acta. 693:41-46., Number 1–2 AbstractWebsite
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da Silva, MS, Viveiros R, Morgado PI, Aguiar-Ricardo A, Correia IJ, Casimiro T.  2011.  Development of 2-(dimethylamino)ethyl methacrylate-based molecular recognition devices for controlled drug delivery using supercritical fluid technology. International Journal of Pharmaceutics. 416:61-68., Number 1 AbstractWebsite

This work reports the development of a novel potential body-friendly oral drug delivery system, which consists of a biocompatible molecularly imprinted polymer (MIP), with pH sensitive character and low cross-linking degree (20.2 wt%), synthesized and processed in supercritical carbon dioxide. The \{MIP\} is synthesized using 2-(dimethylamino)ethyl methacrylate (DMAEMA) as functional monomer and ethylene glycol dimethacrylate (EGDMA) as cross-linker, and ibuprofen as molecular recognition template. The imprinted matrix was able to show a higher affinity towards ibuprofen than its corresponding non-imprinted polymer (NIP) meaning that the molecular imprinting in scCO2 was efficient even using a low crosslinking degree. \{MIP\} showed a significant molecular recognition towards the template, presenting higher drug uptake ability in the supercritical impregnation step, loading 33.1 wt% of ibuprofen compared to only 10.2 wt% for the \{NIP\} polymer. In vitro drug release experiments, simulating an oral administration, showed different release profiles at pH 2.2 and pH 7.4. Zeta potential measurements were performed to both \{MIP\} and \{NIP\} showing that the imprinting process has a significant influence on the charge of the polymeric particles. Cytotoxicity assays performed with human colorectal carcinoma-derived Caco-2 cells demonstrated that the polymers are biocompatible and could be potentially used in drug delivery applications.

da Silva, MS, Nobrega FL, Aguiar-Ricardo A, Cabrita EJ, Casimiro T.  2011.  Development of molecularly imprinted co-polymeric devices for controlled delivery of flufenamic acid using supercritical fluid technology. The Journal of Supercritical Fluids. 58:150-157., Number 1 AbstractWebsite

This work reports the development of a novel class of affinity co-polymeric materials using supercritical fluid technology. Polymeric materials with molecular recognition to flufenamic acid, were first synthesized in supercritical carbon dioxide (scCO2) using the drug as template. Molecularly imprinted co-polymers of methacrylic acid (MAA) or N-isopropyl acrylamide (NIPAAm) crosslinked with ethylene glycol dimethacrylate (EGDMA) were synthesized using different crosslinking degrees and template:monomer ratios, at 65 °C and 21 MPa. High-pressure \{NMR\} experiments confirmed that the nature of the interactions between the drug and the functional monomers during the polymerization step are mainly hydrogen bonds. scCO2-assisted impregnation revealed that the imprinted matrices were able to uptake higher amounts of flufenamic acid. This effect was particularly evidenced in the more crosslinked matrices, with P(MAA–EGDMA) imprinted copolymers binding up to 101.5 mg drug/g polymer against only 50.5 mg/g in the non-imprinted copolymer. In vitro drug delivery experiments showed that imprinted co-polymers release the drug in a more sustained way than the corresponding non-imprinted matrices. Overall it was shown that supercritical fluid technology is a viable approach for the development of self-assembly molecular recognition polymers with potential application in controlled drug delivery systems.

Freitas, F, Alves VD, Torres CAV, Cruz M, Sousa I, Melo MJ, Ramos AM, Reis MAM.  2011.  Fucose-containing exopolysaccharide produced by the newly isolated Enterobacter strain A47 DSM 23139. Carbohydrate Polymers. 83:159-165., Number 1 AbstractWebsite
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Neves, P, Amarante TR, Gomes AC, Coelho AC, Gago S, Pillinger M, Goncalves IS, Silva CM, Valente AA.  2011.  Heterogeneous oxidation catalysts formed in situ from molybdenum tetracarbonyl complexes and tert-butyl hydroperoxide. Applied Catalysis a-General. 395:71-77., Number 1-2 AbstractWebsite
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Antunes, R, Coito F, Duarte-Ramos H.  2011.  A Linear Approach towards Modeling Human Behavior. Technological Innovation for Sustainability. :305–314.: Springer Abstract

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Luis, AS, Alves VD, Romao MJ, Prates JAM, Fontes CMGA, Najmudin S.  2011.  Overproduction, purification, crystallization and preliminary X-ray characterization of a novel carbohydrate-binding module of endoglucanase Cel5A from Eubacterium cellulosolvens. Acta Crystallographica Section F-Structural Biology and Crystallization Communications. 67:491-493. AbstractWebsite
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Rosatella, AA, Afonso CAM, Branco LC.  2011.  Oxidation of Cyclohexene to trans-1,2-Cyclohexanediol Promoted by p-Toluenesulfonic Acid without Organic Solvents. Journal of Chemical Education. 88:1002-1003., Number 7 AbstractWebsite
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Almeida, R, Ortigueira MD, Batista AG, Ktonas P.  2011.  Sleep Spindles: Decomposition, Parameterization and Applications. 19th IEEE Conference on Signal Processing and Communications Applications. Abstract
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Neves, P, Gago S, Balula SS, Lopes AD, Valente AA, Cunha-Silva L, Almeida Paz FA, Pillinger M, Rocha J, Silva CM, Goncalves IS.  2011.  Synthesis and Catalytic Properties of Molybdenum(VI) Complexes with Tris(3,5-dimethyl-1-pyrazolyl)methane. Inorganic Chemistry. 50:3490-3500., Number 8 AbstractWebsite
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Martins, R, Nathan A, Barros R, Pereira L\'ıs, Barquinha P, Correia N, Costa R, Ahnood A, Ferreira I, Fortunato E.  2011.  {Complementary metal oxide semiconductor technology with and on paper.}. Advanced materials (Deerfield Beach, Fla.). 23:4491–6., Number 39 AbstractWebsite
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2010
Silveira, CM, Gomes SP, Araujo AN, Montenegro MC, Todorovic S, Viana AS, Silva RJ, Moura JJ, Almeida MG.  2010.  An efficient non-mediated amperometric biosensor for nitrite determination, May 15. Biosens Bioelectron. 25:2026-32., Number 9 AbstractWebsite

In this paper we propose the construction of a new non-mediated electrochemical biosensor for nitrite determination in complex samples. The device is based on the stable and selective cytochrome c nitrite reductase (ccNiR) from Desulfovibrio desulfuricans, which has both high turnover and heterogeneous electron transfer rates. In opposition to previous efforts making use of several redox mediators, in this work we exploited the capacity of ccNiR to display a direct electrochemical response when interacting with pyrolytic graphite (PG) surfaces. To enable the analytical application of such bioelectrode the protein was successfully incorporated within a porous silica glass made by the sol-gel process. In the presence of nitrite, the ccNiR/sol-gel/PG electrode promptly displays catalytic currents indicating that the entrapped ccNiR molecules are reduced via direct electron transfer. This result is noteworthy since the protein molecules are caged inside a non-conductive silica network, in the absence of any mediator species or electron relay. At optimal conditions, the minimum detectable concentration is 120 nM. The biosensor sensitivity is 430 mA M(-1) cm(-2) within a linear range of 0.25-50 microM, keeping a stable response up to two weeks. The analysis of nitrites in freshwaters using the method of standard addition was highly accurated.

Ramos, S, Almeida RM, Moura JJ, Aureliano M.  2010.  Implications of oxidovanadium(IV) binding to actin, Jun. J Inorg Biochem. 105:777-83., Number 6 AbstractWebsite

Oxidovanadium(IV), a cationic species (VO(2+)) of vanadium(IV), binds to several proteins, including actin. Upon titration with oxidovanadium(IV), approximately 100% quenching of the intrinsic fluorescence of monomeric actin purified from rabbit skeletal muscle (G-actin) was observed, with a V(50) of 131 muM, whereas for the polymerized form of actin (F-actin) 75% of quenching was obtained and a V(50) value of 320 muM. Stern-Volmer plots were used to estimate an oxidovanadium(IV)-actin dissociation constant, with K(d) of 8.2 muM and 64.1 muM VOSO(4), for G-actin and F-actin, respectively. These studies reveal the presence of a high affinity binding site for oxidovanadium(IV) in actin, producing local conformational changes near the tryptophans most accessible to water in the three-dimensional structure of actin. The actin conformational changes, also confirmed by (1)H NMR, are accompanied by changes in G-actin hydrophobic surface, but not in F-actin. The (1)H NMR spectra of G-actin treated with oxidovanadium(IV) clearly indicates changes in the resonances ascribed to methyl group and aliphatic regions as well as to aromatics and peptide-bond amide region. In parallel, it was verified that oxidovanadium(IV) prevents the G-actin polymerization into F-actin. In the 0-200 muM range, VOSO(4) inhibits 40% of the extent of polymerization with an IC(50) of 15.1 muM, whereas 500 muM VOSO(4) totally suppresses actin polymerization. The data strongly suggest that oxidovanadium(IV) binds to actin at specific binding sites preventing actin polymerization. By affecting actin structure and function, oxidovanadium(IV) might be responsible for many cellular effects described for vanadium.

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