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TBCCD1 and OFD1, a novel centrosomal protein partnership with a role in human ciliopathies?

Publication . Veiga, Joaquim; Carmona, Bruno; Camelo, Carolina; Pereira, Dulce; Marinho, H. Susana; Soares, Helena

Cilia are hair-like appendages, consisting of a microtubule (MT)-based ciliary axoneme, that fulfill critical motility and sensory functions required for normal embryonic development and also for homeostasis of adult tissues. At their base, cilia have a centriole/basal body, which can be derived from the centrosome, and that nucleates the ciliary axoneme (primary cilia). Centrosomes consist of a pair of centrioles surrounded by the pericentriolar matrix that nucleate/organize the cytoskeleton and are implicated in cell migration, adhesion and polarity, while in mitosis they assist spindle pole formation.

2017-05Conference object

Open access

The effect of ionic Co presence on the structural, optical and photocatalytic properties of modified cobalt–titanate nanotubes

Publication . Barrocas, B.; Silvestre, António Jorge; Rolo, A. G.; Monteiro, O. C.

With the aim of producing materials with enhanced optical and photocatalytic properties, titanate nanotubes (TNTs) modified by cobalt doping (Co-TNT) and by Na+ -> Co ion-exchange (TNT/Co) were successfully prepared by a hydrothermal method. The influence of the doping level and of the cobalt position in the TNT crystalline structure was studied. Although no perceptible influence of the cobalt ion position on the morphology of the prepared titanate nanotubes was observed, the optical behaviour of the cobalt modified samples is clearly dependent on the cobalt ions either substituting the Ti4+ ions in the TiO6 octahedra building blocks of the TNT structure (doped samples) or replacing the Na+ ions between the TiO6 interlayers (ion-exchange samples). The catalytic ability of these materials on pollutant photodegradation was investigated. First, the evaluation of hydroxyl radical formation using the terephthalic acid as a probe was performed. Afterwards, phenol, naphthol yellow S and brilliant green were used as model pollutants. Anticipating real world situations, photocatalytic experiments were performed using solutions combining these pollutants. The results show that the Co modified TNT materials (Co-TNT and TNT/Co) are good catalysts, the photocatalytic performance being dependent on the Co/Ti ratio and on the structural metal location. The Co(1%)-TNT doped sample was the best photocatalyst for all the degradation processes studied.

2016-07-21Journal article

Restricted access

An AFM, TEM, XRD and luminescence study of carbon nanomaterials obtained from cork industry wastewater

Publication . Prata, José Virgílio; Monteiro, O. C.; Silvestre, António Jorge; Viana, A. S.; Costa, Alexandra

Quercus suber L. (cork oak) contributes significantly to the economies of several European Union countries. The industrial processing of cork planks involves a cooking operation in which the textural and plastic properties of cork are improved. The resulting wastewater (ca. 400 L/ton of processed cork) is rich in water-soluble extractives, namely phenol- and polyphenol-based compounds and pectins. While the presence of these and other compounds usually defy several spent water treatment processes owing to their inherent poor biodegradability, they represente otherwise a huge opportunity to produce high-valued carbon-based materials.

2017-09Conference object

Open access

pH-switchability and second-order nonlinear optical properties of monocyclopentadienylruthenium(II)/iron(II) tetrazoles/tetrazolates: synthesis, characterization, and time-dependent density functional theory calculations

Publication . Florindo, Pedro R.; Costa, Paulo J.; Piedade, M. F. M.; Robalo, Maria Paula

Tetrazole/tetrazolate monocydopentadienyliron(II) and ruthenium(II) compounds of general formulas [(eta(5)-C5H5)M(dppe)(N-4(H)CC6H4NO2)][PF6]/[(eta(5)-C5H5)M(dppe)(N4CC6H4NO2] were investigated for their pH-switching second-order nonlinear optical (SONLO) properties. Compounds [(eta(5)-C5H5)M(dppe)(N4CC6H4NO2) (M = Fe, Ru) and compound [(eta(5)-C5H5)Ru(dppe)(N-4(H)CC6H4NO2)][PF6] were fully characterized by (H-1-, C-13-, P-31-) NMR, cyclic voltammetty, and elemental analysis, and compounds [(eta(5)-C5H5)Fe(dppe)(N4CC6H4NO2)] and [(eta(5)-C5H5)Ru(dppe)(N-4(H)CC6H4NO2)][PF6] were further characterized by single-crystal X-ray diffraction; the synthesis of [(eta(5)-C5H5)Fe(dppe)(N-4(H)CC6H4NO2)][PF6] was unsuccessful. Time-dependent density functional theory calculations were performed using PBE0 and CAM-B3LYP functionals to evaluate the first hyperpolarizability (beta(tot)) of the tetrazole/tetrazolate complexes and for a detailed analysis of the experimental data. Both functionals piedict (i) high first hyperpolarizabilities for the tetrazolate complexes [(eta(5)-C5H5)M(dppe)(N4CC6H4NO2)], with beta(tot)[Ru] approximate to 1.2 beta(tot)[Fe], and (ii) a 3-fold reduction in beta(tot)[Ru] protonation, in complex [(eta(5)-C5H5)Ru(dppe)(N-4(H)CC6H4NO2)](+), forecasting [(eta(5)-C5H5)Ru(dppe)(N4CC6H4NO2)]/[(eta(5)-C5H5)Ru(dppe)(N-4(H)CC6H4NO2)](+) complexes as on/off, pH-switchable SONLO forms.

2017-06-19Journal article

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Improved cyclohexane oxidation catalyzed by a heterogenized Iron (II) complex on hierarchical Y zeolite through surfactant mediated technology

Publication . Van-Dúnem, Vanmira; Carvalho, Ana; Martins, Luisa; Martins, Angela

The hydrotris (pyrazol-1-yl) methane iron (II) complex [FeCl2 (Tpm)] [Tpm=HC(C3N2H3)3] was successfully immobilized, by the incipient wetness impregnation method, in parent and hierarchical Y zeolite modified through surfactant mediated methodology using different bases (NH4OH, NaOH or TPAOH). The catalytic performance and recyclability of supported Fe complex was evaluated in the oxidation of cyclohexane with hydrogen peroxide to cyclohexanol and cyclohexanone under mild conditions and two distinct behaviors were observed: using commercial Y and modified Y with NaOH the complex is anchored mainly at the outer surface of the zeolite supports, resulting in high lixiviation after the first catalytic cycle. When NH4OH and TPAOH are used during the zeolite treatments the particular textural parameters exhibited by these two supports are able to effectively retain the complex molecules, resulting in a high recyclability observed after three consecutive cycles, especially when NH4OH treated zeolite was used as support.

2018-09-20Journal article

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