Search results for " pollutant"
showing 10 items of 1149 documents
Uridine uptake inhibition as a cytotoxicity test for a human hepatoma cell line (HepG2 cells): comparison with the neutral red assay
2001
International audience; This study describes a sensitive microassay for measuring cytotoxicity based on the degree of inhibition of RNA synthesis in HepG2 cells. RNA synthesis is measured by the kinetic uptake of radiolabeled uridine. A large number of compounds were tested in a wide range of concentrations. The concentration required to induce 50% inhibition of HepG2 uridine uptake rates (IC50) was determined for each compound and used to rank its potency. These IC50s were compared with IC50s measured with the neutral red assay. 2-acetylaminofluorene, benzo[a]pyrene and methylnitrosourea were not cytotoxic in the neutral red assay. Uridine uptake was always inhibited at lower concentrations…
Development of a polydimethylsiloxane–thymol/nitroprusside composite based sensor involving thymol derivatization for ammonium monitoring in water sa…
2014
This report describes a polydimethylsiloxane (PDMS)-thymol/nitroprusside delivery composite sensor for direct monitoring of ammonium in environmental water samples. The sensor is based on a PDMS support that contains the Berthelot's reaction reagents. To prepare the PDMS-thymol/nitroprusside composite discs, thymol and nitroprusside have been encapsulated in the PDMS matrix, forming a reagent release support which significantly simplifies the analytical measurements, since it avoids the need to prepare derivatizing reagents and sample handling is reduced to the sampling step. When, the PDMS-thymol/nitroprusside composite was introduced in water samples spontaneous release of the chromophore…
Complete sequencing of Novosphingobium sp. PP1Y reveals a biotechnologically meaningful metabolic pattern.
2014
Background Novosphingobium sp. strain PP1Y is a marine α-proteobacterium adapted to grow at the water/fuel oil interface. It exploits the aromatic fraction of fuel oils as a carbon and energy source. PP1Y is able to grow on a wide range of mono-, poly- and heterocyclic aromatic hydrocarbons. Here, we report the complete functional annotation of the whole Novosphingobium genome. Results PP1Y genome analysis and its comparison with other Sphingomonadal genomes has yielded novel insights into the molecular basis of PP1Y’s phenotypic traits, such as its peculiar ability to encapsulate and degrade the aromatic fraction of fuel oils. In particular, we have identified and dissected several highly …
Variability of aerosol, gaseous pollutants and meteorological characteristics associated with continental, urban and marine air masses at the SW Atla…
2011
Abstract. Measurements of the ambient aerosol were performed at the Southern coast of Spain, within the framework of the DOMINO (Diel Oxidant Mechanisms In relation to Nitrogen Oxides) project. The field campaign took place from 20 November until 9 December 2008 at the atmospheric research station "El Arenosillo" (37°5'47.76" N, 6&deg44'6.94" W). As the monitoring station is located at the interface between a natural park, industrial cities (Huelva, Seville) and the Atlantic Ocean a variety of physical and chemical parameters of aerosols and gas phase could be characterized in dependency on the origin of air masses. Backwards trajectories were examined and compared with local meteor…
Multimycotoxin analysis in water and fish plasma by liquid chromatography-tandem mass spectrometry
2015
High performance liquid chromatography-mass spectrometry was used for the determination of 15 mycotoxins in water and fish plasma samples, including aflatoxins, fumonisins, ochratoxin A, sterigmatocistin, fusarenon-X and emerging Fusarium mycotoxins. In this work, dispersive liquid-liquid microextraction (DLLME) was assessed as a sample treatment for the simultaneous extraction of mycotoxins. Results showed differences in recovery assays when different extraction solvents were employed. Ethyl acetate showed better recoveries for the major part of mycotoxins analyzed, except for aflatoxins B2, G1 and G2, which showed better recoveries when employing chloroform as extractant solvent. Fumonisi…
A passive sampling-based analytical strategy for the determination of volatile organic compounds in the air of working areas.
2010
Abstract An analytical methodology based on the use of a polyethylene layflat tube filled with activated carbon and Florisil (ACFL-VERAM) was employed for the passive sampling of volatile organic compounds (VOCs) in the air of working areas of packing industries. VOCs amount in the ACFL-VERAM sampler was directly determined through head-space-gas chromatography–mass spectrometry (HS-GC–MS) allowing a direct determination in only 20 min without the need of any previous treatment. Uptake parameters, like sampling rate ( R S ) and sampler–air partition coefficient ( K SA ), were determined for every studied VOC from adsorption isotherm data. Additionally, experimental equations have been propo…
Bimodal copper oxide nanoparticles doped phase for the extraction of highly polar compounds by in-tube solid-phase microextraction coupled on-line to…
2020
Abstract Polymers obtained from tetraethyl orthosilicate (TEOS) and triethoxymethylsilane (MTEOS) have been functionalized with different metal and metal oxide nanoparticles (NPs), and used as coatings of extractive capillaries for the extraction of polar compounds by in-tube solid-phase microextraction (IT-SPME) coupled on-line to nano-liquid chromatography (nano-LC). The extraction capabilities of the new phases have been studied using several triazinic herbicides with log of octanol/water partition coefficients (Kow) ranging from -0.7 to 3.21 under reversed phase chromatographic conditions. Best extraction efficiencies for the most polar compounds (log Kow ≤ 2.3) were typically obtained …
Laboratory investigation into the development of resistance of Daphnia magna to the herbicide molinate.
2003
Daphnia magna (F0 generation) was exposed to different sublethal molinate concentrations (0, 3.77, 4.71, 6.28, 9.42, and 18.85 mg/L) during 21 days. Chronic toxicity tests, using the same herbicide concentrations, were also carried out during 21 days using neonates of F1 first brood (F1-1st) and F1 third brood (F1-3rd) offspring generations from the parentals (F0) preexposed to the herbicide. Finally, offspring (from F1-1st and F1-3rd broods) were transferred to herbicide-free medium during a 21-day recovery period. The alga Nannochloris oculata (5 x 10(5) cells/mL) was used as food in all the experiments. The effect of molinate on survival, reproduction, and growth was monitored for the se…
Caloric content of Daphnia magna as reflect of propanil stress during a short-term exposure and its relationship to long-term responses
2013
The present study investigates energy stores changes in the aquatic invertebrate Daphnia magna following a 5-d exposure to propanil. Juveniles of D. magna were exposed to sublethal propanil concentrations (0.07, 0.10, 0.21 and 0.55 mgl(-1)) which were used previously to test their effect on reproduction, growth and survival (21 days test) of D. magna. Glycogen, total lipids, proteins, and dry weight were determined in control and exposed daphnids at 24, 48, 72, 96 and 120 h. Data were used to calculate caloric content as biomarker of propanil exposure. Results showed a depletion of energy reserves in D. magna exposed to the herbicide. At 120 h of exposure to the highest propanil concentrati…
Rat olfactory bulb and epithelium UDP-glucuronosyltransferase 2A1 (UGT2A1) expression: in situ mRNA localization and quantitative analysis.
2001
UDP-glucuronosyltransferases (UGTs) form a multigenic family of enzymes involved in the biotransformation and elimination of numerous endo- and xenobiotic compounds. Beside the diverse UGT isoforms present in the liver as well as in other tissues, the UGT2A1 isoform, also called olfactory UGT, was initially thought to be expressed in the nasal epithelium only. In this work, we demonstrate the UGT2A1 mRNA expression in the olfactory bulb, using in situ hybridization and quantitative reverse transcription-polymerase chain reaction (RT-PCR) techniques. Within the epithelium, UGT2A1 mRNA is mainly found in the sustentacular cells and to a lesser extent in Bowman's gland cells. Moreover, in situ…