Search results for "Aromatic Hydrocarbons"
showing 10 items of 107 documents
Innovations in Extractive Phases for In-Tube Solid-Phase Microextraction Coupled to Miniaturized Liquid Chromatography: A Critical Review
2020
Over the past years, a great effort has been devoted to the development of new sorbents that can be used to pack or to coat extractive capillaries for in-tube solid-phase microextraction (IT-SPME). Many of those efforts have been focused on the preparation of capillaries for miniaturized liquid chromatography (LC) due to the reduced availability of capillary columns with appropriate dimensions for this kind of system. Moreover, many of the extractive capillaries that have been used for IT-SPME so far are segments of open columns from the gas chromatography (GC) field, but the phase nature and dimensions are very limited. In particular, polar compounds barely interact with stationary GC phas…
An Expanded 2D Fused Aromatic Network with 90-Ring Hexagons
2022
[EN]Two-dimensional fused aromatic networks (2D FANs) have emerged as a highly versatile alternative to holey graphene. The synthesis of 2D FANs with increasingly larger lattice dimensions will enable new application perspectives. However, the synthesis of larger analogues is mostly limited by lack of appropriate monomers and methods. Herein, we describe the synthesis, characterisation and properties of an expanded 2D FAN with 90-ring hexagons, which exceed the largest 2D FAN lattices reported to date. This work was carried out with support from the Basque Science Foundation for Science (Ikerbasque),POLYMAT, the University of the Basque Country,Gobierno Vasco (BERC programme) and Gobierno d…
O-Doped Nanographenes: A Pyrano/Pyrylium Route Towards Semiconducting Cationic Mixed-Valence Complexes
2020
Herein we report an efficient synthesis to prepare O‐doped nanographenes, which derive from the longitudinally and latitudinally p‐extension of pyrene. The derivatives are highly fluorescent and feature low‐oxidation potentials. Exploiting electrooxidation, crystals of cationic mixed valence (MV) complexes were grown in which the organic salts organize into face‐to‐face p‐ p stacks, a favorable solid‐state arrangement for organic electronics. Variable‐temperature EPR measurements and relaxation studies suggest a strong electron delocalization along the longitudinal axis of the columnar p‐stacking architectures. Electric measurements of single crystals of the MV salts exhibited a semiconduct…
Effects of Polycyclic Aromatic Hydrocarbons on Lung Function in Children with Asthma: A Mediation Analysis.
2022
Studies investigating the association between urinary Polycyclic Aromatic Hydrocarbons (PAHs) and asthma in children provided inhomogeneous results. We aimed to use Mediation Analysis to discover whether a link between urinary PAHs and lung function exists and if it might be ascribed to a direct or a symptom-mediated (indirect) effect in children with asthma. This single-center prospective study was conducted in Palermo, Italy, between March and July 2017 and involved 50 children with persistent mild-moderate asthma, aged 6–11 years. At each time visit (day 0, 30, 60, and 90), physical examination, spirometry, and urine collection for detection of urinary cotinine and PAHs were performed. A…
Emerging contaminants related to the occurrence of forest fires in the Spanish Mediterranean
2017
Forest fires can be a source of contamination because, among others, of the use of chemicals to their extinction (flame retardants, FRs), or by the production of Polycyclic Aromatic Hydrocarbons (PAHs) derived from high temperature alteration of organic matter. Up to our knowledge, this study is the first to assess the direct (PAHs 16 on the USA EPA's priority list), and indirect [tri- to hepta- brominated diphenyl ethers (PBDEs), organophosphorus flame retardants (PFRs) and perfluoroalkyl substances (PFASs)] contamination related to forest fires. The abundance and distribution of these contaminants were monitored on two Mediterranean hillslopes, one burned and one unburned, near Azuébar (S…
Possible impacts of Hg and PAH contamination on benthic foraminiferal assemblages: An example from the Sicilian coast, central Mediterranean
2007
The Palermo and Augusta urban/industrial areas (Sicily) are examples of contaminated coastal environments with a relatively high influx of unregulated industrial and domestic effluents. Three sediment box-cores were collected offshore of these urban/industrial areas in water depths of 60-150 m during two cruises (summers 2003/2004), dated by (210)Pb and (137)Cs, and analysed for total mercury concentration and total polycyclic aromatic hydrocarbon (PAH) concentration. Benthic foraminiferal assemblages were also examined (in terms of their distribution and morphology) to assess the potential use of benthic foraminifera as bioindicators of pollutant input and environmental change in these Med…
Glutathione Conjugation of Bay- and Fjord-Region Diol Epoxides of Polycyclic Aromatic Hydrocarbons by Glutathione Transferases M1-1 and P1-1
1997
Metabolism of polycyclic aromatic hydrocarbons in mammalian cells results in the formation of vicinal diol epoxides considered as ultimate carcinogens if the oxirane ring is located in a bay- or fjord-region of the parent compound. In the present study, individual stereoisomers of the bay-region diol epoxides of chrysene, dibenz[a,h]anthracene, and benzo[a]pyrene as well as of the fjord-region diol epoxides of benzo[c]phenanthrene, benzo[c]chrysene, and benzo[g]-chrysene have been incubated with GSH in the presence of human glutathione transferases GSTM1-1 (a mu-class enzyme) and GSTP1-1 (a pi-class enzyme). As previously shown with GSTA1-1 (an alpha-class enzyme) both M1-1 and P1-1 demonst…
Exposure to retene, fluoranthene, and their binary mixture causes distinct transcriptomic and apical outcomes in rainbow trout (Oncorhynchus mykiss) …
2022
Polycyclic aromatic hydrocarbons (PAHs) are widely spread environmental contaminants which affect developing organisms. It is known that improper activation of the aryl hydrocarbon receptor (AhR) by some PAHs contributes to toxicity, while other PAHs can disrupt cellular membrane function. The exact downstream mechanisms of AhR activation remain unresolved, especially with regard to cardiotoxicity. By exposing newly hatched rainbow trout alevins (Oncorhynchus mykiss) semi-statically to retene (32 µg l−1; AhR agonist), fluoranthene (50 µg l−1; weak AhR agonist and CYP1a inhibitor) and their binary mixture for 1, 3, 7 and 14 days, we aimed to uncover novel mechanisms of cardiotoxicity using a…
Endogenous AhR agonist FICZ accumulates in rainbow trout (Oncorhynchus mykiss) alevins exposed to a mixture of two PAHs, retene and fluoranthene
2022
AbstractMultiple studies have reported synergized toxicity of PAH mixtures in developing fish larvae relative to the additive effect of the components. From a toxicological perspective, multiple mechanisms are known to contribute to synergism, such as altered toxicodynamics and kinetics, as well as increased oxidative stress. An understudied contributor to synergism is the accumulation of endogenous metabolites, for example: the aryl hydrocarbon receptor 2 (AhR2) agonist and tryptophan metabolite 6-Formylindolo(3,2-b)carbazole (FICZ). Fish larvae exposed to FICZ, alongside knock-down of cytochrome p450 (cyp1a), has been reported to induced symptoms of toxicity similar to those observed foll…
Polycyclic Aromatic Hydrocarbons Phenanthrene and Retene Modify the Action Potential via Multiple Ion Currents in Rainbow Trout Oncorhynchus mykiss C…
2019
Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous contaminants in aqueous environments. They affect cardiovascular development and function in fishes. The 3-ring PAH phenanthrene has recently been shown to impair cardiac excitation-contraction coupling by inhibiting Ca2+ and K+ currents in marine warm-water scombrid fishes. To see if similar events take place in a boreal freshwater fish, we studied whether the PAHs phenanthrene and retene (an alkylated phenanthrene) modify the action potential (AP) via effects on Na+ (INa ), Ca2+ (ICaL ), or K+ (IKr , IK1 ) currents in the ventricular myocytes of the rainbow trout (Oncorhynchus mykiss) heart. Electrophysiological characteristics of myo…