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How does heat-shock affect the influence of titanium dioxide nanoparticles in g...
Capela-Pires, J; Ferreira, Rui; Alves-Pereira, IsabelNanomaterials include all substances that contain nanoscale structures sized between 1 and 100 nm. At this size, the characteristics of materials change: their strength, conductivity, and reactivity, which differ substantially from macro- or micron- sized materials, shifting the rules of physics and chemistry to the sidelines. Although, the geological origin and the ubiquitous occurrence of nanoparticles in the...
Titanium dioxide nanoparticles inhibits Saccharomyces cerevisiae BY4741 prolife...
Capela-Pires, J; Ferreira, Rui; Alves-Pereira, Isabelphysicochemical properties are poorly known. In the case of metal nanoparticles, their dimension is often important, since their surface area increases as molecular size decreases, causing alterations in their magnetic and thermodynamic properties. Consequently, the influence they exert on life is an attractive topic of research in biochemical toxicology by the novelty of their behavior. Although titanium diox...
Nanoparticles of titanium dioxide modulate the response to temperature by key e...
Capela-Pires, J; Ferreira, Rui; Alves-Pereira, IsabelNanotechnology can be used to obtain materials at nanoscale (<100 nm) with new physicochemical and structural properties which depend on particle size and, probably, may trigger new biological effects. As Saccharomyces cerevisiae is an excellent model for study molecular and cell biology responses is growingly used in the toxicological evaluation of chemicals, such as heavy metals or nanoparticles of metal oxid...
Nanopartículas de dióxido de titânio revertem a repressao catabólica pela glico...
Capela-Pires, J; Ferreira, Rui; Alves-Pereira, IsabelA nanotecnologia liberta para o ambiente materiais com dimensão entre 1 e 100 nm, cujas propriedades magnéticas e termodinâmicas, maioritariamente condicionadas pela área superficial/dimensão molecular, determinam o tipo de interacção que estabelecem com as biomoléculas. A caracterização dos efeitos biológicos das nanopartículas constitui assim um tema de investigação aliciante em toxicologia bioquímica, pelo s...
Nanopartículas de dióxido de titânio ativam vias de desintoxicação celular cito...
Capela-Pires, JA origem geológica e a ocorrência ubíqua das nanopartículas (NPs) podem levar a supor uma boa adaptação filogenética dos seres vivos a este tipo de substâncias. Contudo, o desenvolvimento industrial, associado a novas e vastas aplicações dos nanomateriais, tem contribuido para elevar os seus níveis ambientais [1]. Por esse motivo, a preocupação com a pressão ambiental das nanopartículas em determinadas regiões ...
PAH air pollution at a Portuguese urban area: carcinogenic risks and sources id...
Slezakova, Klara; Pires, J. C. M.; Castro, Dionísia; Alvim-Ferraz, Maria da Conceição M.; Delerue-Matos, Cristina; Morais, S.; Pereira, Maria do CarmoThis study aimed to characterize air pollution and the associated carcinogenic risks of polycyclic aromatic hydrocarbon (PAHs) at an urban site, to identify possible emission sources of PAHs using several statistical methodologies, and to analyze the influence of other air pollutants and meteorological variables on PAH concentrations.The air quality and meteorological data were collected in Oporto, the second l...
Differential growth inhibition of Saccharomyces cerevisiae UE-ME3 and BY4741 by...
Capela-Pires, J; Ferreira, Rui; Alves-Pereira, INanoparticles of titanium dioxide, widely used as pigments or cosmetics, are usually found in molecular size < 100 nm. Sometimes, their poor thermal stability and large surface area can be correlated with their reactivity to cause changes in gene expression that may be used as biomarkers of exposure and cytotoxicity. Although the nanomaterials may be useful in medicine, their exposition to air or ultraviolet ra...
Differential survival of Saccharomyces cerevisiae UE-ME3 and BY4741 strains to ...
Capela-Pires, J; Ferreira, Rui; Alves-Pereira, IsabelNanotechnology has released materials into the environment whose action on living organisms is poorly known and that is urgent clarify. Some authors have shown that these materials behave as ROS generators, reason which justifies its use in studies of stress. In general, the cell health is correlated with elevated values of GSH/GSSG ratio, a marker of stability linked to a highly reducing environment. Changes i...
Central 5-HT2A receptors modulate the vagal bradycardia in response to activati...
Futuro Neto,H.A.; Macedo,S.M.; Silva,N.F.; Cabral,A.M.; Pires,J.G.P.Activation of 5-hydroxytryptamine (5-HT) 5-HT1A, 5-HT2C, 5-HT3, and 5-HT7 receptors modulates the excitability of cardiac vagal motoneurones, but the precise role of 5-HT2A/2B receptors in these phenomena is unclear. We report here the effects of intracisternal (ic) administration of selective 5-HT2A/2B antagonists on the vagal bradycardia elicited by activation of the von Bezold-Jarisch reflex with phenylbigua...
Proliferação de Saccharomyces cerevisiae na presença de metais de transição
Agostinho, J; Capela-Pires, J; Alves-Pereira, I; Ferreira, RuiOs resultados mostram que em células crescidas na presença de nanopartículas de titânio ou de pentóxido de vanádio ocorreu um decréscimo significativo de unidades formadoras de colónias, bem como, da actividade específica fosfatase alcalina. Contudo, S. cerevisiae crescidas na presença de pentóxido de vanádio, um pró-oxidante, e sumo de maçã golden mostraram uma reversão significativa da citototoxidade do vanád...
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