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191.
The sensitivity of Lepidium sativum L. germination to three imidazolium ionic liquids was investigated in solutions and soils artificially contaminated with
mixtures of those compounds. In case of aquatic solutions, the toxic character of analyzed compounds is connected with their
hydrophobicity. The seedling growth is increasing with the decrease in ionic liquid hydrophobicity. The novelty of those studies
is the application of high-performance liquid chromatography, which was used for the determination of ionic liquid quantity
absorbed by cress. There was almost linear relationship between decrease in root germination and amount of ionic liquid uptaken
by cress. Furthermore, the systematic studies on the influence of total organic carbon content in soil on the toxicity of
ionic liquids to cress were performed for the first time. Hazardous effects appeared to be closely connected with organic
matter: with the decrease of total organic carbon quantity, the inhibition of plant growth was more significant. Visual effects
of ionic liquid toxic activity to garden cress are similar as in the case of nutrient deficit in plants.
Figure Visual phytotoxicity effects observed during the test; leaf chromatosis: light green and yellow (up photos), violet (lower
photos) 相似文献
192.
The electrochemical properties of dinotefuran (DNF) were studied by SW voltammetry over the pH range 2.0–8.0 using a silver amalgam film electrode Hg(Ag)FE. The mechanism of electroreduction was analyzed. The dependence of the peak current on pH, buffer concentration, the nature of the buffer, amplitude, frequency, step potential and scan rate were investigated. The repeatability, precision and recovery of the developed method were checked. The detection and quantification limits were found to be 2.01×10?7 and 6.71×10?7 mol L?1, respectively. The standard addition method was used to determine DNF in spiked carrot juice. 相似文献
193.
Blasticidin S (BS) was determined in spiked rice samples by square wave voltammetry (SWV) and square wave stripping voltammetry (SWSV) using a cyclic renewable silver amalgam film electrode (Hg(Ag)FE). It was found that the compound can act as an electrocatalyst. In Britton? Robinson buffer at pH 7.0 a signal connected with the hydrogen evolution reaction was detected at ?1.2 V versus Ag/AgCl. Validation of the method was carried out. The detection and quantification limits were found to be 2.13×10?8 mol L?1; 7.10×10?8 mol L?1 for SWV and 2.65×10?9 mol L?1; 8.85×10?9 mol L?1 for SWSV, respectively. 相似文献
194.
Sylwia Malinowska Marianna Gniadek Tomasz Rapecki Eliza Kurek Zbigniew Stojek Mikołaj Donten 《Journal of Solid State Electrochemistry》2014,18(11):3049-3055
The consequences of treatment of gold nanocrystals present in polypyrrole–gold composites and electrodeposited gold nanocrystals (PPY–Au and Au NPs) with OH radicals generated in Fenton’s reaction were investigated. Particularly, the changes in the morphology and the electrochemical properties of those materials are shown. For both materials, the etching effect was noticed. Contrary to significantly reduced catalytic activity, the changes observed in size and shape of gold nanostructures were less pronounced. In the case of PPY–Au composite material, the etching effects were less intense. Even after a 60-min radical treatment of the PPY–Au composite material, the gold–nanocrystal catalytic activity remained high. The limited dissolution of the gold nanocrystals in the PPY–Au composites, compared to bare Au NPs, can be explained by the presence of the polymer which served as a kind of protective barrier against the oxidizing agent. A decrease in the electrocatalytic properties vs. the electrooxidation of ethanol of both forms of gold nanocrystals were observed after the treatment with hydroxyl radicals. 相似文献
195.
Sylwia Siebielec Grzegorz Siebielec Piotr Sugier Magorzata Wo
niak Jarosaw Grzdziel Anna Gazka Tomasz Stuczyski 《Molecules (Basel, Switzerland)》2020,25(23)
The aim was to assess plant driven changes in the activity and diversity of microorganisms in the top layer of the zinc and lead smelter waste piles. The study sites comprised two types (flotation waste—FW and slag waste—SW) of smelter waste deposits in Piekary Slaskie, Poland. Cadmium, zinc, lead, and arsenic contents in these technosols were extremely high. The root zone of 8 spontaneous plant species (FW—Thymus serpyllum, Silene vulgaris, Solidago virgaurea, Echium vulgare, and Rumex acetosa; and SW—Verbascum thapsus; Solidago gigantea, Eupatorium cannabinum) and barren areas of each waste deposit were sampled. We observed a significant difference in microbial characteristics attributed to different plant species. The enzymatic activity was mostly driven by plant-microbial interactions and it was significantly greater in soil affected by plants than in bulk soil. Furthermore, as it was revealed by BIOLOG Ecoplate analysis, microorganisms inhabiting barren areas of the waste piles rely on significantly different sources of carbon than those found in the zone affected by spontaneous plants. Among phyla, Actinobacteriota were the most abundant, contributing to at least 25% of the total abundance. Bacteria belonging to Blastococcus genera were the most abundant with the substantial contribution of Nocardioides and Pseudonocardia, especially in the root zone. The contribution of unclassified bacteria was high—up to 38% of the total abundance. This demonstrates the unique character of bacterial communities in the smelter waste. 相似文献
196.
Höppe HA Kazmierczak K Kacprzak S Schellenberg I Pöttgen R 《Dalton transactions (Cambridge, England : 2003)》2011,40(39):9971-9976
The optical emission properties of the lanthanoid catena-polyphosphates Ln(PO(3))(3) (Ln = Y, Gd, Lu) doped with europium were investigated. Incommensurately modulated β-Y(PO(3))(3):Eu (super space group Cc (0|0.364|0)0) and Gd(PO(3))(3):Eu (space group I2/a) show the usual emission characteristics of Eu(3+), while in Lu(PO(3))(3):Eu (space group Cc) the europium is unprecedentedly partially reduced to the divalent state, as proven by both a broad emission band at 406 nm excited at 279 nm and an EPR spectroscopic investigation. (151)Eu-M?ssbauer spectroscopy showed that only a very small part of the europium is reduced in Lu(PO(3))(3):Eu. An explanation for this unusual behaviour is given. 相似文献
197.
Hirtz M Corso R Sekula-Neuner S Fuchs H 《Langmuir : the ACS journal of surfaces and colloids》2011,27(18):11605-11608
Dip-pen nanolithography (DPN) with phospholipids has been shown to be a powerful tool for the generation of biologically active surface patterns, but screening of the obtained lithographic structures is still a bottleneck in the quality control of the prepared samples. Here we performed a comparative study with atomic force microscopy (AFM), fluorescence microscopy (FM), and surface-enhanced ellipsometric contrast (SEEC) microscopy of phospholipid membrane stacks consisting of 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC) with high admixing of 1,2-dipalmitoyl-sn-glycero-3-phosphoethanolamine-N-[6-[(2,4-dinitrophenyl)amino]hexanoyl] (DNP Cap PE) produced by DPN. We present a structural model of membrane stacking based on the combined information gained from the three microscopic techniques. Domains of phase-separated DNP Cap PE can be detected at high DNP Cap PE admixing that are not present at medium or low admixings. While the optical methods allow for a high-throughput screening of lithographic structures (compared to AFM), it was found that, when relying on FM alone, artifacts due to phase-separation phenomena can be introduced in the case of thin membrane stacks. 相似文献
198.
A simple and fast ultra-high-performance liquid chromatography (UHPLC) method was developed for the identification and quantification of the following flavonoids in red wine: (+/-)-catechin, (-)-epicatechin, rutin, quercitrin, hesperidin, neohesperidin, (+/-)-naringenin, hesperetin, and chrysin. Chromatographic separation of the flavonoids was performed on a Chromolith Fast Gradient C18e column. A gradient elution was used with mobile phases consisting of 0.1% formic acid in water and acetonitrile. UV detection was performed at 280 nm. A complete separation of flavonoids was possible within 6 min. The calibration curves showed good linearity (R2 > or = 0.9990) in the selected range of each analyte; the LOD ranged between 0.06 and 0.19 microg/mL. An optimized sample preparation method utilized SPE. The Oasis HLB column with the highest recoveries was selected for the preconcentration step. This method was successfully applied to the determination of these flavonoids in the red wine samples with excellent results. 相似文献
199.
Sylwia Grabska Alina Sionkowska 《International Journal of Polymer Analysis and Characterization》2019,24(4):285-294
In this paper, the results regarding the influence of UV-irradiation with 254?nm wavelength on the surface and mechanical properties of hyaluronic acid, hyaluronic acid/collagen and hyaluronic acid/collagen/chitosan mixtures are presented. For this study, thin films were prepared by solvent evaporation from solution of HA and mixtures made from HA/Coll and HA/Coll with 30% addition of chitosan. The surface properties of films were investigated by AFM and using contact angle measurements, allowing the calculation of surface free energy and its components. Mechanical properties of films made of biopolymeric blends before and after UV-irradiation have been investigated by mechanical testing machine. 相似文献
200.
Marta Głodek Sylwia Pawlędzio Dr. Anna Makal Prof. Damian Plażuk 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(57):13131-13145
The influence of the chemical substitution, crystal packing, and aurophilic interactions of the gold(I) acetylide complexes of the type (ArCOC≡C)nAuPEt3 (n=1,2) on their luminescent properties were examined. All described complexes undergo ligand scrambling in solution, which results in the formation of stable, easily isolated crystals that contain [ArCO(C≡C)n]2Au−(Et3P)2Au+ homoleptic species. In particular, we observed that the (benzoylacetylide)gold(I) complex yields three crystal forms with strikingly different luminescence properties. We monitored the conversion pathway for these forms: an orange luminescent form of homoleptic complex upon drying undergoes spontaneous transformation to bright green fluorescent form and finally to the weakly blue emissive one. In addition, we report a rare example of a helical arrangement of Au⋅Au⋅Au chains that are observed for the first time in acetylide gold(I) complexes in the case of heteroleptic (benzoylacetylide)gold(I) complex. This is a very rare case in which crystal structures and ensuing electronic properties of the heteroleptic and AuI complexes could be directly compared. 相似文献