Browsing by Author "Rosická, Petra"

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    Advanced Characterization of Natural Biofilm on Nanofiber Scaffold
    (ACAD SCIENCES CZECH REPUBLIC, INST PHYSIOLOGY, VIDENSKA 1083, PRAGUE 4 142 20, CZECH REPUBLIC, 2019-01-01) Svobodová, Lucie; Lederer, Tomáš; Rosická, Petra; Svoboda, Přemysl; Novák, Libor; Dostálová, Jana; Jirků, Vladimír
    Nanofiber scaffolds provide numerous advantages over common carriers engineered for microorganisms. The most important advantage is an increased speed of primary surface colonization (up to four times faster), which shortens the time required for the areal biofilm formation and optimum performance of attached microorganisms (higher efficiency of biological activity of up to twice as fast). Image analysis predicts early formation of biofilm even in beginning stages; analysis of biofilm reveals the different structures of bacterial colonies on both scaffolds (higher porosity, size, and number of bacterial colonies on nanofiber's surface). The image analysis correlates well with determinations of dry matter (linear correlation of 0.96) and proteins (linear correlation of 0.89).
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    An across-species comparison of the sensitivity of different organisms to Pb-based perovskites used in solar cells
    (ELSEVIER, RADARWEG 29, 1043 NX AMSTERDAM, NETHERLANDS, 2020-01-01) Wang, Guiyin; Zhai, Yujia; Zhang, Shirong; Diomede, Luisa; Bigini, Paolo; Romeo, Margherita; Cambier, Sebastien; Contal, Servane; Nguyen, Nhung H. A.; Rosická, Petra; Ševců, Alena; Nickel, Carmen; Vijver, Martina G.; Peijnenburg, Willie J. G. M.
    Organic-inorganic perovskite solar cells (PSCs) are promising candidates as photovoltaic cells. Recently, they have attracted significant attention due to certified power conversion efficiencies exceeding 23%, low-cost engineering, and superior electrical/optical characteristics. These PSCs extensively utilize a perovskite-structured composite with a hybrid of Pb-based nanomaterials. Operation of them may cause the release of Pb-based nanoparticles. However, limited information is available regarding the potential toxicity of Pb-based PSCs on various organisms. This study conducted a battery of in vitro and in vivo toxicity bioassays for three quintessential Pb-based PSCs (CH3NH3PbI3, NHCHNH3PbBr3, and CH3NH3PbBr3) using progressively more complex forms of life. For all species tested, the three different perovskites had comparable toxicities. The viability of Caco-2/TC7 cells was lower than that of A549 cells in response to Pbbased PSC exposure. Concentration-dependent toxicity was observed for the bioluminescent bacterium Vibrio fischeri, for soil bacterial communities, and for the nematode Caenorhabditis elegans. Neither of the tested Pb-based PSCs particles had apparent toxicity to Pseudomonas putida. Among all tested organisms, V. fischeri showed the highest sensitivity with EC50 values (30 min of exposure) ranging from 1.45 to 2.91 mg L-1. Therefore, this study recommends that V. fischeri should be preferably utilized to assess. PSC toxicity due to its increased sensitivity, low costs, and relatively high throughput in a 96-well format, compared with the other tested organisms. These results highlight that the developed assay can easily predict the toxic potency of PSCs. Consequently, this approach has the potential to promote the implementation of the 3Rs (Replacement, Reduction, and Refinement) principle in toxicology and decrease the dependence on animal testing when determining the safety of novel PSCs.