Browsing by Author "Figueiredo, Daniela R."
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- Chemical speciation and oxidative potential of PM10 in different residential microenvironments: Bedroom, living room and kitchenPublication . Cipoli, Yago Alonso; Vicente, Estela D.; Evtyugina, Margarita; Figueiredo, Daniela R.; Pietrogrande, Maria C.; Lucarelli, Franco; Feliciano, Manuel; Ryšavý, Jiří; Alves, CéliaExposure to particulate matter (PM) and its chemical constituents in residential microenvironments has become a major health concern worldwide. The oxidative potential (OP) has been proposed as a metric for estimating the PM capacity to induce oxidative stress and, consequently, health effects. In the present study, PM10 was daily monitored simultaneously in the bedroom, living room and kitchen of three dwellings for one week in a small town of Portugal, to perform a detailed characterisation of its organic and inorganic constituents and the determination of the OP. Bedrooms (B) were found to be a hotspot of PM10 concentrations (B1 = 22.7 μg m-3; B2 = 19.5 μg m-3; B3 = 68.1 μg m-3). PM10-bound elements varied significantly between microenvironments in all dwellings. Lower molecular weight polycyclic aromatic hydrocarbons (PAHs) were found to be between 14 and 72 times higher than high molecular weight PAHs in bedrooms. The mean volume-normalised OP determined by the dithiothreitol and ascorbic acid assays varied within the 0.01–0.38 nmol min-1 m-3 and 0.03–0.53 nmol min-1 m-3 ranges, respectively. Quinones, oxy-aromatic, aromatic and alkyl-aromatic compounds stood out in bedrooms. Strong and significantly positive relationship between OP and black carbon, Cu and Br were observed, indicating common redox active species mainly associated with traffic emissions. Sr, Fe, Zn and Zr presented higher concentrations in dwelling 3, exhibiting excellent positive correlation with OP, indicating that the Sahara dust intrusion recorded in that house may have contributed to the formation of more redox active species thought to drive antioxidant depletion responses.
- Fatty acid characterization of cyanobacterial strains isolated from Vela lake and Mondego river rice fields (central-western, Portugal)Publication . Galhano, Victor; Santos, H.; Geraldes, Ana Maria; Figueiredo, Daniela R.; Crespí, António; Gomes-Laranjo, José; Peixoto, Francisco P.
- Fatty acid characterization of cyanobacterial strains isolated from vela lake and mondego river rice fields (central-western, Portugal)Publication . Galhano, Victor; Santos, Hugo; Geraldes, Ana Maria; Figueiredo, Daniela R.; Crespí, António; Gomes-Laranjo, José; Peixoto, Francisco P.It is know that cyanobacterial taxonomic groups are characterized by particular lipid patterns that can be used as their biological markers. The present study examined the fatty acid composition of nostocacean heterocystous cyanobacterial strains isolated from Central-western Portuguese freshwater shallow water bodies, namely Vela Lake and rice fields from Mondego River Basin. Morphological characterization showed that strains from Vela Lake belonged to Aphanizomenon gracile (strains UADFA16 and UADFA18), Aphanizomenon flos-aquae (strain UADFA15) and Anabaena cf. solitaria (strain UADFA14) species, whereas rice field strains belonged to Anabaena cylindrica (strain UTAD_A212) and Nostoc muscorum (strain UTAD_N213). Biochemical characterization inferred from lipid analysis showed that predominant fatty acid methyl esters (FAMEs) in the lipids of the strains were palmitic, oleic and α-linolenic, with trace amounts of myristic and C20 polyunsaturated FAMEs. To our knowledge, there is almost no information about lipid composition in freshwater cyanobacterial species living in different habitats in Portugal. Therefore, this limnological study is a contribution to our investigation on freshwater diazotrophic cyanobacteria.