binary mixture
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Primary hepatocyte assay was used to determine acute toxicity of nickel(II) chloride ? 3,4-dichloroaniline and nickel(II) chloride ? sodium diclophenac mixtures. Although the components act by different mechanisms, their acute toxicity was almost additive; it decreased to zero in dependence on the molar ratio of the components. Toxicities of pollutants in environment may decrease due to interactions with other components.
Surface energy is extensively adopted to predict the surface properties of materials nowadays. Our study was aimed at utilizing the surface free energy measured by inverse gas chromatography to determine inter-particle interactions and to describe the overall behaviour of mixtures. The model drugs of different solubility (tadalafil, levocetirizine dihydrochloride, vardenafil hydrochloride, and amlodipine besylate) and two grades of polyvinylpyrrolidone (Kollidon® 12 PF, Kollidon® VA 64) were mixed in various ratios. Investigated components were characterized using inverse gas chromatography, particle size distribution and specific surface area. We also determined the work of adhesion and cohesion between the components in the binary mixtures. Due to the formation of levocetirizine agglomerates, the effect of mixing time on both components of the surface free energy was also studied for the binary mixture with Kollidon® VA 64. The results based on the energy analysis, especially positive or negative excess surface energies in theoretical and real binary mixtures, indicate that we can predict whether the components can form the desired ordered (interactive) mixture. For this reason, we have proposed, to the best of our knowledge, different approach to predict the interactions between components and their behaviour in the binary mixtures using inverse gas chromatography in terms of the energy balance based only on the surface parameters (surface free energy, dispersive and specific surface energy). Therefore, the approach of energy balance is an innovative and comparatively simple tool for analysis and identification of interactions between components in particulate systems, which can also predict the quality of the mixing.
- MeSH
- acetylcholinesterasa analýza MeSH
- biologické markery MeSH
- butyrylcholinesterasa analýza MeSH
- cholinesterasové inhibitory MeSH
- inhalační expozice MeSH
- krysa rodu rattus MeSH
- organofosforové sloučeniny škodlivé účinky MeSH
- sarin analýza krev škodlivé účinky MeSH
- zvířata MeSH
- Check Tag
- krysa rodu rattus MeSH
- zvířata MeSH
Humic substances (HS) are ubiquitous natural products of decomposition of dead organic matter. HS is present in most freshwaters at concentrations ranging from 0.5 to 50mg L(-1). Organic carbon can represent 20% dry weight of sediments. Recently, the interaction of dissolved HS with the aryl hydrocarbon receptor (AhR) has been demonstrated. The AhR is a cytosolic receptor to which persistent organic pollutants (POPs) can bind and many of their toxic effects are mediated through interactions with this receptor. We describe in vitro effects (using H4IIE-luc cells) of binary mixtures of various HS with 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), since in contaminated environments these compounds occur simultaneously. Six out of 12 HS samples activated AhR even at environmentally relevant concentrations (17 mg L(-1)), but did not reach the full AhR-activation even at excessive concentration. In simultaneous exposure of H4IIE-luc to HS (17 mg L(-1)) and TCDD (1.2 pM) without any preincubation prior to exposure, either significant additive or facilitative effects were observed. No negative interactions, due to possible sorption of TCDD to HS was observed. Nevertheless, if the HS-TCDD binary mixture was preincubated for 6 days prior to the exposure on H4IIE-luc cells, the additive and facilitative effects were less due to possible sorption of TCDD onto HS. Similar results were obtained from analogous experiments with greater concentrations of both TCDD and HS.
- MeSH
- huminové látky toxicita MeSH
- kinetika MeSH
- krysa rodu rattus MeSH
- látky znečišťující půdu toxicita MeSH
- nádorové buněčné linie MeSH
- polychlorované dibenzodioxiny toxicita MeSH
- receptory aromatických uhlovodíků metabolismus MeSH
- regenerace a remediace životního prostředí metody MeSH
- zvířata MeSH
- Check Tag
- krysa rodu rattus MeSH
- zvířata MeSH
- Publikační typ
- práce podpořená grantem MeSH
An environmental isolate Comamonas testosteroni RF2 has been previously described to cometabolize trichloroethene (TCE), 1,2-cis-dichloroethene (cDCE), 1,2-trans-dichloroethene (tDCE), and 1,1-dichloroethene (1,1DCE) when grown on phenol and lactate sodium. In this study, three vinyl chloride (VC) degrading strains, Mycobacterium aurum L1, Pseudomonas putida PS, and Rhodococcus ruber Sm-1 were used to form consortia with the strain RF2 in terms to achieve the removal of VC along with above-mentioned chloroethenes. Degradation assays were performed for a binary mixture of cDCE and VC as well as for a mixture of TCE, all DCEs and VC. The consortium composed of C. testosteroni RF2 and M. aurum L1 showed to be the most efficient towards the removal of cDCE (6.01 mg L-1) in the binary mixture with VC (10 mg L-1) and was capable of efficiently removing chloroethenes in the mixture sample at the initial concentrations of 116 μg L-1 for TCE, 662 μg L-1 for cDCE, 42 μg L-1 for tDCE, 16 μg L-1 for 1,1DCE, and 7 mg L-1 for VC with a removal efficiency of nearly 100% for all of the compounds. Although complete removal of VC took a significantly longer time than the removal of other chloroethenes, the consortium composed of C. testosteroni RF2 and M. aurum L1 displayed strong bioremediation potential for aquifers with downstream contamination characterized by the presence of less chlorinated ethenes.
