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da Costa Zaragoza de Oliveira Pedro, Paulo Miguel
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- Influence of particle size on ecotoxicity of low-density polyethylene microplastics, with and without adsorbed benzo-a-pyrene, in Clam Scrobicularia planaPublication . Rodrigues, Ana Rita; Mestre, Nélia; FONSECA, TAINÁ; Pedro, Paulo; Carteny, Camilla C.; Cormier, Bettie; Keiter, Steffen; Bebianno, Maria JoãoThis study investigated the ecotoxicological effects of differently sized (4–6 µm and 20–25 µm) low-density polyethylene (LDPE) microplastics (MPs), with and without adsorbed benzo-a-pyrene (BaP), in clam Scrobicularia plana. Biomarkers of oxidative stress (superoxide dismutase—SOD; catalase—CAT), biotransformation (glutathione-S-transferases—GST), oxidative damage (lipid peroxidation—LPO) and neurotoxicity (acetylcholinesterase—AChE) were analysed in gills and digestive glands at different time intervals for a total of 14 days of exposure. In order to have a better impact perspective of these contaminants, an integrated biomarker response index (IBR) and Health Index were applied. Biomarker alterations are apparently more related to smaller sized (4–6 µm) MPs in gills and to virgin LDPE MPs in the digestive gland according to IBR results, while the digestive gland was more affected by these MPs according to the health index.
- Photocatalytic composite nanomaterial and engineering solution for inactivation of airborne bacteriaPublication . Danilenko, Igor; Gorban, Oksana; Pedro, Paulo; Viegas, Joao; Shapovalova, Olesya; Akhkozov, Leonid; Konstantinova, Tetyana; Lyubchyk, SvitlanaIn this study we propose a new composite material with an enhanced bactericidal action that utilises the complex interactions with bacteria: mechanical interactions of the bacteria with ZnO tetrapod spikes, a photocatalytic process on ZnO nanoparticles, and disinfection by Ag nanoparticles. ZnO and Ag nanoparticles were immobilised on a single-crystalline ZnO tetrapod by the ultrasonic mixing method. The XRD, TEM, SEM and EDS analyses showed the tetrapod-like crystals covered by ZnO and Ag nanoparticles. This complex photocatalytic material, deposited on a grid support, was tested in the UV purifier air system in the AR Diagnostic company. The active microbial monitoring of the indoor air showed a decrease in the concentration of bacteria in the air of the meeting room, with the door open, at 90% for a duration of 30-40 min. A simple variant of the design of an air purifier system, which can be mounted in different types of air channels and compartments, is proposed.