Pokročilé polymerní materiály a kompozit
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- ItemGrooves on the cortex of the Epigravettian lithic industry in the broader context(Hugo Obermaier-Society for Quaternary Research and Archaeology of the Stone Age, 2024-01-17) Nerudová, Zdeňka; Lepcio, PetrThe southern part of the Brno urban agglomeration (Czech Republic) is a crucial region for understanding the Late Upper Palaeolithic (Epigravettian) occupation in Central Europe. Despite limited archaeological research in the urban area, the newly uncovered Brno-Štýřice IIIb site has provided additional information about the character of the Palaeolithic occupation, the hunted fauna, and climate. Our information about the Late Palaeolithic has been increased by recent finds. In this article we present two unique finds, both lithic chipped pieces with grooves on the cortex, found in a well-dated stratigraphic context at the recently excavated area. The different kinds of grooves on the cortex of the chipped stone artefacts can be understood as an example of possible intentional modification of the subjects. We will try to resolve the question of whether these pieces can be understood as non-utilitarian pieces, decorations, symbols (which are rare in the Epigravettian), or if the pieces represent the results of everyday Palaeolithic life.
- ItemAssessing Lettuce Exposure to a Multipharmaceutical Mixture under Hydroponic Conditions: Findings through LC-ESI-TQ Analysis and Ecotoxicological Assessments(AMER CHEMICAL SOC, 2024-11-28) Mravcová, Ludmila; Jašek, Vojtěch; Hamplová, Marie; Navrkalová, Jitka; Amrichová, Anna; Zlámalová Gargošová, Helena; Fučík, JanThe escalating global water scarcity demands innovative solutions, one of which is hydroponic vegetable cultivation systems that increasingly use reclaimed wastewater. Nevertheless, even treated wastewater may still harbor various emerging organic contaminants, including pharmaceuticals. This study aimed to comprehensively assess the impact of pharmaceuticals, focusing on bioconcentration factors (BCFs), translocation factors (TFs), pharmaceutical persistence in aqueous environment, ecotoxicological end points, and associated environmental and health risks. Lettuce (Lactuca sativa) was cultivated hydroponically throughout its entire growth cycle, exposed to seven distinct concentration levels of contaminants ranging from 0 to 500 mu gL-1 over a 35-day period. The findings revealed a diverse range of BCFs (2.3 to 880 Lkg(-1)) and TFs (0.019-1.48), suggesting a high potential of pharmaceutical uptake and translocation by L. sativa. The degradation of 20 pharmaceuticals within the water-lettuce system followed first-order degradation kinetics. Substantial ecotoxicological effects on L. sativa were observed, including increased mortality, alterations in root morphology and length, and changes in biomass weight (p < 0.05). Furthermore, the estimated daily intake of pharmaceuticals through L. sativa consumption suggested considerable health risks, even if lettuce would be one of the many vegetables consumed. It is hypothetical, as the values were calculated. Moreover, this study assessed the environmental risk associated with the emergence of antimicrobial resistance (AMR) in aquatic environments, revealing a significantly high risk of AMR emergence. In conclusion, these findings emphasize the multifaceted challenges posed by pharmaceutical contamination in aquatic environments and the necessity of proactive measures to mitigate associated risks to both environmental and human health.
- ItemAssessing Lettuce Exposure to a Multi-Pharmaceutical Mixture in Soil: Insights from LC-ESI-TQ Analysis and the Impact of Biochar on Pharmaceutical Bioavailability(AMER CHEMICAL SOC, 2024-09-04) Fučík, Jan; Jašek, Vojtěch; Hamplová, Marie; Navrkalová, Jitka; Zlámalová Gargošová, Helena; Mravcová, LudmilaAgricultural practices introduce pharmaceutical (PhAC) residues into the terrestrial environment, potentially endangering agricultural crops and human health. This study aimed to evaluate various aspects related to the presence of pharmaceuticals in the lettuce-soil system, including bioconcentration factors (BCFs), translocation factors (TFs), ecotoxicological effects, the influence of biochar on the PhAC bioavailability, persistence in soil, and associated environmental and health risks. Lettuce (Lactuca sativa L.) was exposed to a mixture of 25 PhACs in two scenarios: initially contaminated soil (ranging from 0 to 10,000 ng center dot g(-1)) and soil irrigated with contaminated water (ranging from 0 to 1000 mu g center dot L-1) over a 28-day period. The findings revealed a diverse range of BCFs (0.068-3.7) and TFs (0.032-0.58), indicating the uptake and translocation potential of pharmaceuticals by lettuce. Significant ecotoxicological effects on L. sativa, including weight change and increased mortality, were observed (p < 0.05). Interestingly, biochar did not significantly affect PhAC uptake by L. sativa (p > 0.05), while it significantly influenced the soil degradation kinetics of 12 PhACs (p < 0.05). Additionally, the estimated daily intake of PhACs through the consumption of L. sativa suggested negligible health risks, although concerns arose regarding the potential health risks if other vegetable sources were similarly contaminated with trace residues. Furthermore, this study evaluated the environmental risk associated with the emergence of antimicrobial resistance (AMR) in soil, as medium to high. In conclusion, these findings highlight the multifaceted challenges posed by pharmaceutical contamination in agricultural environments and emphasize the importance of proactive measures to mitigate the associated risks to both environmental and human health.
- ItemGraphene quantum dots-From spectroscopic performance to 3D printing applications and interaction studies with normal and cancer cells(Elsevier, 2024-05-27) Krok-Janiszewska, Dominika; Wielgus, Weronika; Środa, Patrycja; Tyszka-Czochara, Małgorzata; Lepcio, Petr; Kasprzyk, Wiktor; Ortyl, JoannaIn this study, different types of graphene quantum dots (GQDs) are investigated to understand their spectroscopic properties. Morphological and size analyses were performed. The mechanism of action of radical photopolymerization was evaluated. The obtained materials proved to be useful for developing efficient photoinitiating systems for 3D printing applications. In addition, the cytotoxicity of the GQDs was studied, and their effects on living cells were investigated. We demonstrated that GQDs can not only act as efficient photoinitiators but also as constituents of hydrogels that express very low toxicity and may interact with cells. The latter makes it possible to study them in the future as useful modern biosensors.
- ItemAnatase and rutile nanoparticles in photopolymer 3D-printed nanocomposites: Band gap-controlled electron interactions in free-radical and cationic photocuring(Elsevier, 2024-07-01) Korčušková, Martina; Svatík, Juraj; Tomal, Wiktoria; Šikyňová, Aneta; Vishakha, Vishakha; Petko, Filip; Galek, Mariusz; Stalmach, Paweł; Ortyl, Joanna; Lepcio, PetrThe preparation of functional photopolymer nanocomposites is affected by both the physical and chemical interactions of nanoparticles (NPs) and polymer resin. Some NPs, such as semiconducting metal oxides, may contribute by their photocatalytic behavior and electron transfer, influencing the kinetics of the photopolymerization reaction. This study has investigated the complex effect of titanium dioxide (TiO 2 ) NPs in anatase and rutile form on the conversion, kinetics, and printability of free -radical and cationic photopolymerization resin. Two different polymorphs of TiO 2 NPs ensured identical chemical properties, but different physical effects related to their varying band gap energies and electron transfer efficiency. These parameters were found to be crucial for influencing the photopolymerization kinetics. While rutile showed a more pronounced enhancement of the free -radical photopolymerization ' s conversion and kinetics, cationic photopolymerization was favourably affected only by anatase NPs due to the photosensitization effect. These findings are critical in understanding and designing functional nanocomposite materials processed by vat photopolymerization 3D printing that could find use in optical, medical, or environmental applications.