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Comparative study on hydrolysis and bioethanol production from cardoon and rock...
Fernandes, M. C.; Ferro, M. D.; Paulino, A. F. C.; Evtuguin, D. V.; Xavier, A. M. R. B.; Chaves, HumbertoBioethanol production potential from cardoon ( Cynara cardunculus ) and rockrose ( Cistus ladanifer ), pretreated by diluted acid hydrolysis (DAH), was studied and compared by both, separate enzymatic hydrolysis and fermentation (SHF) and simultaneous saccharification and fermentation (SSF) processes. DAH pretreatment allowed an increase of 5 fold to cardoon and 16 fold to rockrose in cellulose accessibility to...
Dextrin-based hydrogel for the development of injectable bone substitute
Pereira, Isabel; Simões, J.; Fraga, S.; Maltez, L.; Evtuguin, D. V.; Domingues, R. M.; Coimbra, M. A.; Teixeira, J. P.; Maurício, A. C.; Santos, J. D.[Excerpt] The development of injectable bone substitutes (IBS) have garnered great importance in the bone regeneration field, as a strategy to reach areas of the body using minimally invasive procedures, and showing the ability of perfect fitting according to irregularities of bone tissue defects. In this context, the combination of injectable hydrogels and ceramic granules is emerging as a well-established tre...
Catalytic oxidation of formaldehyde by ruthenium multisubstituted tungstosilici...
Gamelas, J. A. F.; Oliveira, F.; Evtyugina, M. G.; Portugal, I.; Evtuguin, D. V.Cellulose/silica hybrid material produced by a sol-gel method from cellulosic fibres and silica precursors (tetraethoxysilane and 3-aminopropyltriethoxysilane) was functionalized with alpha-[SiW9O37Ru3III(H2O)(x)Cl3-x]((10-x)-) (Ru-POM), and thoroughly characterised by C-13 and Si-29 solid state NMR, FTIR spectroscopy, UV-vis reflectance spectroscopy, X-ray diffraction, thermogravimetric analysis, scanning elec...
New polyoxometalate-functionalized cellulosic fibre/silica hybrids for environm...
Gamelas, J. A. F.; Evtyugina, M. G.; Portugal, I.; Evtuguin, D. V.Cellulosic fibre/silica hybrid materials functionalized with Keggin-type polyoxometalates ([PV2Mo10O40]52, [PVMo11O40]42, ([PMo12O40]32 or [PW12O40]32) were prepared by a sol–gel method at room temperature. The novel materials are composed of ca. 56 wt% of polysaccharides, ca. 37 wt% of propylamine-modified silica, 2 wt% of polyoxometalate, and 5% of hydration water. The silica network of these hybrids exhibits...
Polyoxometalate/laccase-mediated oxidative polymerization of catechol for texti...
Kim, Suyeon; Silva, Carla Manuela Pereira Marinho da; Evtuguin, D. V.; Gamelas, José A. F.; Paulo, Artur CavacoThe synergistic effect between polyoxometalates (POMs), namely K5[SiW11VVO40]·11H2O and H5[PMo10 VV2O40]·13H2O and laccase from ascomycete Myceliophthora thermophila has been employed for the first time in oxidative polymerization of catechol. Such a laccase-mediator system allowed the formation of a relatively high molecular weight polycatechol as confirmed by size exclusion chromatography and electrospray ion...
Enhancement of rate and extension of enzymatic hydrolysis of cellulose by high ...
Ferreira, A. R. F. C.; Figueiredo, A. B.; Evtuguin, D. V.; Saraiva, J. A.Resumo indisponível.
Characterisation of enzymatically oxidised lignosulfonates and their applicatio...
Kim, Suyeon; Silva, Carla Manuela Pereira Marinho da; Zille, Andrea; López, C.; Evtuguin, D. V.; Paulo, Artur CavacoThe ‘double function’ of laccase, from the ascomycete Myceliophthora, to depolymerise/polymerise lignin was studied in this work. A lignosulfonate (LS) compound was oxidised by enzymatic action and several techniques were applied to measure the polymeric changes obtained. This study was focused on the attachment level of the oxidised LS at the flax surface. RESULTS: Modified solutions were studied in terms of s...
Polyoxometalates as mediators in the laccase catalyzed delignification
Balakshin, M. Yu.; Evtuguin, D. V.; Neto, C. Pascoal; Paulo, Artur CavacoThe polyoxometalate (POM)-laccase catalytic system was applied for the first time to aerobic delignification of kraft pulps at moderate (40-60 degreesC) temperatures. Laccase was found to readily catalyze the re-oxidation of different kinds of polyoxometalates, including those, which cannot be re-oxidized by dioxygen even at high temperatures (PMo11V1, SiW11V1. etc.). This allows a sequence of catalytic redox c...
Polyoxometalates as promoters of laccase-assisted reactions
Carneiro, Andrea; Abreu, Ana S.; Evtuguin, D. V.; Neto, C. Pascoal; Gübitz, Georg M.; Paulo, Artur CavacoA synergistic effect of polyoxometalate and laccase benzenediol:oxygen oxidoreductase, EC 1.10.3.2 has been observed in the aerobic oxidation of a hydrazonaphthalene type colorant. The considerable increase in the decolorization rate of Solophenyl Blue GL dye with the new catalytic system composed by laccase and heptamolybdopentovanadophosphate heteropolyanion, when compared with the treatment with enzyme or he...