Determination of benzomercaptans in environmental complex samples by combining zeolitic imidazolate framework-8-based solid-phase extraction and high-performance liquid chromatography with UV detection.

In this work, the synthesis of zeolitic imidazolate framework-8 (ZIF-8) crystals and their subsequent application as effective sorbents for extraction and preconcentration of several benzomercaptans from environmental complex samples is described. These materials were prepared by solvothermal approach varying the concentration of n-butylamine modulator to modify the surface of the metal-organic framework. The resulting materials were characterized by scanning and transmission electron microscopy, powder X-ray diffraction and Fourier transform infrared spectroscopy. The ZIF-8 material that gave the best features was selected as extractive phase and the influence of various parameters (sample pH and elution solvent composition, among others) on the extraction efficiency of target compounds were investigated. Under the optimal conditions of the method, the tested analytes (2-mercaptobenzothiazole, 2-mercaptobenzoxazole and 2-mercapto-6-nitrobenzothiazole) were retained and eluted quantitatively with alkaline 50:50 (v:v) methanol-water mixture. Using the proposed method, low limits of detection, in the range of 16-21 ng L-1 for aqueous samples and 0.4-0.5 µg kg-1 for soil samples, were achieved whereas the precision (expressed as relative standard deviation) was lower than 7%. The resulting solid-phase extraction protocol, using the zeolitic material as sorbent, was combined with liquid chromatography and ultraviolet-vis detector and successfully applied to determine traces of these organic pollutants in environmental samples.

Carbon composite membrane derived from MIL-125-NH2 MOF for the enhanced extraction of emerging pollutants.

Porous carbon derived from amine-functionalized MIL-125 metal-organic framework (C-MIL-125-NH2) was prepared by carbonization at high temperature under inert atmosphere, and used for adsorption of bisphenol A (BPA) and 4-tert-butylphenol (4-tBP). The obtained carbon showed bimodal porosity and fast extraction of both pollutants in batch conditions following a pseudo-second-order model. The adsorption mechanism was studied by the measurement of zeta potential, and the results suggested that π-π stacking interactions between the carbon material and the phenol molecules probably are the main sorption mechanism. The prepared C-MIL-125-NH2 was incorporated into mechanically stable membranes for flow-through solid-phase extraction of studied phenols prior to HPLC analysis. The hybrid material showed excellent permeance to flow, easy regeneration and good performance for the simultaneous enrichment of mixtures of BPA and 4-tBP, facilitating their determination when present at low concentration levels.

Preliminary results on the uptake and biochemical response to water-exposure of Tamiflu® (oseltamivir phosphate) in two marine bivalves.

Tamiflu® (oseltamivir phosphate, OST) is an antiviral drug used for the pandemic treatment of avian influenza but few data are available regarding its toxicity. It should be noted that acute adverse responses are not likely to occur due to low environmental presence of this drug. Nonetheless, water concentration levels of this compound may reach the µg/L range under influenza episodes. Bivalves are reliable sentinels of chemical exposure due to their low metabolism; however, biotransformation of drugs does occur in these aquatic invertebrates. Two species of bivalves, namely mussels Mytilus galloprovincialis and clams Ruditapes philippinarum, were exposed for 48 h to 100 µg/L OST. Hemolymph from control and treated bivalves was withdrawn and the presence of OST and its metabolite oseltamivir carboxylate (OST-C) determined by LC-MS/MS. Gills and digestive gland were excised from control and exposed bivalves and carboxylesterase (CE) activities measured using different substrates. In addition, antioxidant defences and lipid peroxidation levels were determined. Higher metabolism of OST seemed to occur in mussels, since both OST and OST-C were found in hemolymph, whereas in clams only the parent compound was detected. In contrast, biomarker responses were more evident in exposed clams which indicate that this species may be considered as more sensitive to OST exposure. CE-related activities successfully reflected OST exposure, with substrates 1-naphthyl acetate (1NA) and 1-naphthyl butyrate (1NB) displaying the highest sensitivity in the two bivalve species. Data thus indicate the usefulness of CE-related activities as biomarkers for OST exposure in bivalves.

Progress in human picornavirus research: New findings from the AIROPico consortium.

Several research groups in Europe are active on different aspects of human picornavirus research. The AIROPico (Academia-Industry R&D Opportunities for Picornaviruses) consortium combined the disciplines of pathogenesis, diagnostics and therapy development in order to fill the gaps in our understanding of how picornaviruses cause human disease and how to combat them. AIROPico was the first EU consortium dedicated to human picornavirus research and development, and has largely accelerated and improved R&D on picornavirus biology, diagnostics and therapy. In this article, we present the progress on pathogenesis, diagnostics and treatment strategy developments for human picornaviruses resulting from the structured, translational research approach of the AIROPico consortium. We here summarize new insights in protection against infection by maternal or cross-protective antibodies, the visualisation of interactions between virus and neutralizing antibodies by cryoEM structural imaging, and the outcomes from a picornavirus-infected human 3D organoid. Progress in molecular detection and a fast typing assay for rhinovirus species are presented, as well as the identification of new compounds potentially interesting as therapeutic compounds.

Use of Medaka Fish as Vertebrate Model to Study the Effect of Cocoa Polyphenols in the Resistance to Oxidative Stress and Life Span Extension.

Oxidative stress (OS) can induce cell apoptosis and thus plays an important role in aging. Antioxidant foods protect tissues from OS and contribute to a healthier lifestyle. In this study, we described the used of medaka embryos (Oryzias latipes) to study the putative antioxidant capacity of dietary cocoa extract in vertebrates. A polyphenol-enriched cocoa extract regulated the expression of several genes implicated in OS, thereby protecting fish embryos from induced OS. The cocoa extract activated superoxide dismutase enzyme activity in embryos and adult fish tissues, suggesting a common mechanism for protection during embryonic development and adulthood. Furthermore, long-term feeding of the cocoa extract increased fish life span. Our study demonstrates that the polyphenol-enriched cocoa extract decreases OS and extends life span in medaka fish, validating the use of medaka embryos as an economical platform to screen the antioxidant capacity of food compounds.

Development of a list of reference chemicals for evaluating alternative methods to in vivo fish bioaccumulation tests.

The aim to reduce the number of animals in experiments has highlighted the need to develop and validate nonanimal methods as alternatives to bioaccumulation studies using fish. The present study details a novel 3-tier approach to develop a list of reference compounds to aid this process. The approach was based on 1) the inclusion of relevant chemical classes supported by high-quality in vivo data for the bioconcentration factor (BCF), whole-body biotransformation rates (K(met)), and metabolism characterization for rainbow trout (Oncorhynchus mykiss) and common carp (Cyprinus carpio) (tiers I and II); and 2) the refinement to ensure a broad coverage of hydrophobicity, bioconcentration potential, molecular weight, maximum molecular diameter, whole-body biotransformation half-lives, and metabolic pathways (tier III). In silico techniques were employed to predict maximal log BCF and molecular and metabolic properties. Of the 157 compounds considered as reference compounds, 144 were supported by high-quality BCF data, 8 were supported by K(met) data, and 5 were supported by in vivo metabolism data. Additional criteria for refinement of the list of reference compounds were suggested to aid practical implementation in experimental efforts. The present list of reference compounds is anticipated to facilitate the development of alternative approaches, enhance understanding of in vivo and in vitro bioaccumulation relationships, and refine in silico BCF and metabolism predictions.

Methods for assigning confidence to toxicity data with multiple values--Identifying experimental outliers.

The assessment of data quality is a crucial element in many disciplines such as predictive toxicology and risk assessment. Currently, the reliability of toxicity data is assessed on the basis of testing information alone (adherence to Good Laboratory Practice (GLP), detailed testing protocols, etc.). Common practice is to take one toxicity data point per compound - usually the one with the apparently highest reliability. All other toxicity data points (for the same experiment and compound) from other sources are neglected. To show the benefits of incorporating the "less reliable" data, a simple, independent, statistical approach to assess data quality and reliability on a mathematical basis was developed. A large data set of toxicity values to Aliivibrio fischeri was assessed. The data set contained 1813 data points for 1227 different compounds, including 203 identified as non-polar narcotic. Log KOW values were calculated and non-polar narcosis quantitative structure-activity relationship (QSAR) models were built. A statistical approach to data quality assessment, which is based on data outlier omission and confidence scoring, improved the linear QSARs. The results indicate that a beneficial method for using large data sets containing multiple data values per compound and highly variable study data has been developed. Furthermore this statistical approach can help to develop novel QSARs and support risk assessment by obtaining more reliable values for biological endpoints.

Toxicity and accumulation of silver nanoparticles during development of the marine polychaete Platynereis dumerilii.

Pollutants affecting species at the population level generate ecological instability in natural systems. The success of early life stages, such as those of aquatic invertebrates, is highly affected by adverse environmental conditions. Silver released into the environment from emerging nanotechnology represents such a threat. Sediments are sinks for numerous pollutants, which aggregate and/or associate with depositing suspended particles. Deposit feeder such as the annelid Platynereis dumerilii, which has a large associated literature on its development, is an excellent model organism for exposure studies in coastal environments. We exposed eggs, larvae, juveniles and adults of P. dumerilii to various concentrations of citrate (cit-Ag NPs) or humic acid (HA-Ag NPs) capped silver nanoparticles (Ag NPs) as well to dissolved Ag (added as AgNO3). We showed that mortality and abnormal development rate increased with younger life stages. While adults and juvenile were the most tolerant life stages, fertilized eggs were highly sensitive to AgNO3, cit-Ag NPs and HA-Ag NPs. Exposures to HA-Ag NPs triggered the highest cute toxicity responses in P. dumerilii and in most cases both Ag NPs were more toxic than AgNO3. Uptake rate of HA-Ag NPs in adult worms was also higher than from other Ag forms, consistent with toxicity to other life stages. The early stages of the life cycle of marine coastal organisms are more affected by Ag NPs than the juvenile or adult life stages, indicating that exposure experiments at the larval level contribute to realistic eco-toxicological studies in aquatic environments.