42 research outputs found
Catalytic diesel particulate filters reduce the in vitro estrogenic activity of diesel exhaust
An in vitro reporter gene assay based on human breast cancer T47D cells (ER-CALUXÂź) was applied to examine the ability of diesel exhaust to induce or inhibit estrogen receptor (ER)-mediated gene expression. Exhaust from a heavy-duty diesel engine was either treated by iron- or copper/iron-catalyzed diesel particulate filters (DPFs) or studied as unfiltered exhaust. Collected samples included particle-bound and semivolatile constituents of diesel exhaust. Our findings show that all of the samples contained compounds that were able to induce ER-mediated gene expression as well as compounds that suppressed the activity of the endogenous hormone 17ÎČ-estradiol (E2). Estrogenic activity prevailed over antiestrogenic activity. We found an overall ER-mediated activity of 1.63â±â0.31ng E2 CALUX equivalents (E2-CEQs) per m3 of unfiltered exhaust. In filtered exhaust, we measured 0.74â±â0.07 (iron-catalyzed DPF) and 0.55â±â0.09ng E2-CEQ mâ3 (copper/iron-catalyzed DPF), corresponding to reductions in estrogenic activity of 55 and 66%, respectively. Our study demonstrates that both catalytic DPFs lowered the ER-mediated endocrine-disrupting potential of diesel exhaus
Isocyanate emissions from pyrolysis of mattresses containing polyurethane foam
This study examined the emissions of powerful asthmatic agents called isocyanates from small-scale pyrolysis experiments of two common foams employed in mattress production such as flexible polyurethane foam (FPUF) and viscoelastic memory foam (VMF). A nitrogen atmosphere and five different temperatures, 300, 350, 400, 450 and 850 °C, were selected to carry out the experiments in order to evaluate the worst possible conditions for thermal degradation. A similar trend for both materials was found. At lower temperatures, diisocyanates were the most important products whereas at 850 °C monoisocyanates, and mainly isocyanic acid released mainly from the thermal cracking of diisocyanates evolved directly from the polymer chains. The total yields of isocyanates were in the range of 1.43â11.95 mg/m3 for FPUF at 300-850 °C and 0.05â6.13 mg/m3 for VMF, 300-850 °C. This difference could be a consequence of the lower amount of isocyanates employed in the VMF production which was confirmed by the nitrogen content of the foams, 5.95% FPUF vs. 3.34% in VMF. Additionally, a qualitative search for so far unknown isocyanates was performed in samples from the pyrolysis of FPUF at 300, 400 and 850 °C. It was confirmed that six different aminoisocyanates at 300 °C were evolved, whereas at 400 and 850 °C only five of them were detected. The general trend observed was a decrease of the aminoisocyanate levels with increasing pyrolysis temperature.Support for this work was provided by the Spanish Ministry of Education, Culture and Sport, by the CTQ2013-41006-R project from the Ministry of Economy and Competitiveness (Spain), the PROMETEOII/2014/007 project from the Valencian Community Government (Spain) and a mobility grant by the Spanish Ministry of Education, Culture and Sport (Spain) that enabled MarĂa Garrido to visit EMPA, in Switzerland
Analysis of the Basidiomycete Coprinopsis cinerea Reveals Conservation of the Core Meiotic Expression Program over Half a Billion Years of Evolution
Coprinopsis cinerea (also known as Coprinus cinereus) is a multicellular basidiomycete mushroom particularly suited to the study of meiosis due to its synchronous meiotic development and prolonged prophase. We examined the 15-hour meiotic transcriptional program of C. cinerea, encompassing time points prior to haploid nuclear fusion though tetrad formation, using a 70-mer oligonucleotide microarray. As with other organisms, a large proportion (âŒ20%) of genes are differentially regulated during this developmental process, with successive waves of transcription apparent in nine transcriptional clusters, including one enriched for meiotic functions. C. cinerea and the fungi Saccharomyces cerevisiae and Schizosaccharomyces pombe diverged âŒ500â900 million years ago, permitting a comparison of transcriptional programs across a broad evolutionary time scale. Previous studies of S. cerevisiae and S. pombe compared genes that were induced upon entry into meiosis; inclusion of C. cinerea data indicates that meiotic genes are more conserved in their patterns of induction across species than genes not known to be meiotic. In addition, we found that meiotic genes are significantly more conserved in their transcript profiles than genes not known to be meiotic, which indicates a remarkable conservation of the meiotic process across evolutionarily distant organisms. Overall, meiotic function genes are more conserved in both induction and transcript profile than genes not known to be meiotic. However, of 50 meiotic function genes that were co-induced in all three species, 41 transcript profiles were well-correlated in at least two of the three species, but only a single gene (rad50) exhibited coordinated induction and well-correlated transcript profiles in all three species, indicating that co-induction does not necessarily predict correlated expression or vice versa. Differences may reflect differences in meiotic mechanisms or new roles for paralogs. Similarities in induction, transcript profiles, or both, should contribute to gene discovery for orthologs without currently characterized meiotic roles
Determination of PCDD/F, PCBs and PBDE in Swiss sewage sludge
M. Muñoz agradece el apoyo econĂłmico de la Universidad de Alicante, al proyecto CTQ 2008-05520 del Ministerio Español de EconomĂa y Competitividad y al Departamento de QuĂmica AnalĂtica de EMPA (DĂŒbendorf, Suiza) por permitir el desarrollo de la estancia de investigaciĂłn
New taxa of the water mite family Limnocharidae (Actinotrichida: Eylaoidea) parasitising tropical water bugs of the genus Rhagovelia Mayr, 1865 (Hemiptera: Veliidae) reveal unsuspected diversity of larval morphologies
© 2020 Informa UK Limited, trading as Taylor & Francis Group. The larval stage of Neolimnochares johnstoni Smith and Cook, 2005 is first described in detail, and the larva of a similar undescribed species, Neolimnochares sp. B, see Table 1, is recorded from Peru. Larvae attributed to Limnochares (Cyclothrix) australica Lundblad, 1941a by Martin and Smit (2002) are considered to belong to Neolimnochares Lundblad, 1941c. Neolimnocharinae subfam. n. is proposed and discussed. For larvae assigned to this subfamily, parasitic on veliid water bugs (Rhagovelia Mayr, 1865) and with extraordinary morphological modifications, new taxa are proposed: Veliacola gen. n., (V. mirificus sp. n., Madagascar); Archaeveliacola gen. n. (A. papuanus sp. n., Indonesia, A. smiti sp. n., Australia); Armaveliacola gen. n. (A. rhagoveliae sp. n., Madagascar, A. major sp. n., Madagascar, A. minor sp. n., Cameroon, Kenya); Isoveliacola gen. n. (I. costaricensis sp. n., Costa Rica, I. borneoensis sp. n., Indonesia). Additional records are: Veliacola sp. (Dominican Republic), Archaeveliacola sp. (Bolivia), and Isoveliacola sp. (Belize). Neolimnochares (Paracyclothrix) Lundblad, 1967 is synonymised with Limnochares (Cyclothrix) Wolcott, 1905, resulting in Limnochares (Cyclothrix) hyaliniseta (Lundblad, 1969) comb. n., and L. (C.) longimaxillaris (Lundblad, 1969) comb. n. (both Myanmar). LSID: http://www.zoobank.org/urn:lsid:zoobank.org:pub:275E6D4B-98E7-4A26-B7C7-DABCCF73A9EA
Chemical Composition of Nanoparticles Released from Thermal Cutting of Polystyrene Foams and the Associated Isomerization of Hexabromocyclododecane (HBCD) Diastereomers
Polystyrene foams have various applications, and cutting of them is usually performed with a heated metal wire. However, it has recently been reported that micro- and nanoparticles are released by such thermal cutting at a rate of a few billion particles per second, and these particles have a high likelihood of getting into the respiratory system of the operator. HBCD, as the additive flame retardant, can also be released and is mostly incorporated into the emitted particles
Old Sins Throw Long Shadows â Old and Emerging Persistent Organic Pollutants in the Swiss Environment
Temporal trends and concentrations of dioxins and polybrominated diphenyl ethers in the Swiss environment are presented