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Warfarin, a potential pollutant in aquatic environment acting through Pxr signaling pathway and γ-glutamyl carboxylation of vitamin K-dependent proteins النص الكامل
2014
Fernández, Ignacio | Santos, Adriana | Cancela, M Leonor | Laizé, Vincent | Gavaia, Paulo J.
Warfarin, a potential pollutant in aquatic environment acting through Pxr signaling pathway and γ-glutamyl carboxylation of vitamin K-dependent proteins النص الكامل
2014
Fernández, Ignacio | Santos, Adriana | Cancela, M Leonor | Laizé, Vincent | Gavaia, Paulo J.
Warfarin-induced vitamin K (VK) recycling impairment is used worldwide as a rodenticide and human thromboembolic prophylactic. Since VK metabolism/signaling pathways have been conserved throughout vertebrate evolution, its release to the environment might impact on aquatic organisms. Present study assessed the toxic effect of warfarin (0, 5, 25 and 125 mg L−1) on zebrafish development and characterized underlying mechanisms of action through qPCR analysis of VK-related genes. Expression of pregnane X receptor (pxr), the nuclear receptor binding vitamin K, was ubiquitous in zebrafish and suggests that warfarin exposure may interfere with several biological processes. Indeed, warfarin exposure of zebrafish larvae caused hemorrhages in brain, skeletal deformities and triggered ectopic calcifications, which may be the consequence of an altered γ-carboxylation of VK-dependent proteins and/or pxr signaling. This study provides new insights into warfarin effects as a bone homeostasis disruptor and soft tissue calcification inductor, and its potential risk for aquatic environments.
اظهر المزيد [+] اقل [-]Warfarin, a potential pollutant in aquatic environment acting through Pxr signaling pathway and γ-glutamyl carboxylation of vitamin K-dependent proteins النص الكامل
2014
Fernández Monzón, Ignacio | Santos, Adriana | Cancela, M Leonor | Laizé, Vincent | Gavaia, Paulo J | Fundação para a Ciência e a Tecnologia (Portugal) | European Commission | Fernández Monzón, Ignacio [0000-0002-8088-7902}
10 páginas, 7 figuras, 1 tabla. | Warfarin-induced vitamin K (VK) recycling impairment is used worldwide as a rodenticide and human thromboembolic prophylactic. Since VK metabolism/signaling pathways have been conserved throughout vertebrate evolution, its release to the environment might impact on aquatic organisms. Present study assessed the toxic effect of warfarin (0, 5, 25 and 125 mg L(-1)) on zebrafish development and characterized underlying mechanisms of action through qPCR analysis of VK-related genes. Expression of pregnane X receptor (pxr), the nuclear receptor binding vitamin K, was ubiquitous in zebrafish and suggests that warfarin exposure may interfere with several biological processes. Indeed, warfarin exposure of zebrafish larvae caused hemorrhages in brain, skeletal deformities and triggered ectopic calcifications, which may be the consequence of an altered γ-carboxylation of VK-dependent proteins and/or pxr signaling. This study provides new insights into warfarin effects as a bone homeostasis disruptor and soft tissue calcification inductor, and its potential risk for aquatic environments. | The authors are gratefully to Patrícia Diogo for technical assistance during sampling procedures. IF acknowledges the financial support of the Portuguese Fundation for Science and Technology (FCT) through the post-doctoral grant SFRH/BDP/82049/2011. This work was partly funded by the FCT through SPECIAL K (PDTC/MAR/ 105152/2008) and AQUATOX (PTDC/MAR/112992/2009) projects and by the European Commission (ERDF-COMPETE) through PEstC/MAR/LA0015/2011 project. | Peer reviewed
اظهر المزيد [+] اقل [-]Factors influencing surface CO2 variations in LPRU, Thailand and IESM, Philippines النص الكامل
2014
Macatangay, Ronald | Sonkaew, Thiranan | Velazco, Voltaire | Gerbig, Christoph | Intarat, Nilubol | Nantajai, Nittaya | Bagtasa, Gerry
Surface carbon dioxide concentrations were measured using a non-dispersive infrared carbon dioxide sensor at Lampang Rajabhat University from April to May 2013 and at the University of the Philippines-Diliman campus starting September 2013. Factors influencing the variations in these measurements were determined using multiple linear regression and a Lagrangian transport model. Air temperature and sea level pressure were the dominant meteorological factors that affect the CO2 variations. However, these factors are not enough. Surface CO2 flux and transboundary transport needs to be considered as well.
اظهر المزيد [+] اقل [-]Perfluorinated compounds in serum and urine samples from children aged 5–13 years in South Korea النص الكامل
2014
Kim, Da-Hye | Lee, Mi-Young | Oh, Jeong-Eun
Serum and urine samples from 120 children aged 5–13 years from Dae-gu, Korea, were analyzed for 16 perfluorinated compounds (PFCs). The total PFC concentrations in the serum were 4.26–29.70 ng/mL, and perfluorohexanesulfonate (PFHxS), perfluorooctanoic acid (PFOA), perfluorooctanesulfonate (PFOS, which was dominant overall, at 6.58 ng/mL), and perfluoroundecanoic acid (PFUndA) were detected in all serum samples. The total PFC concentrations in the urine ranged from below the detection limit to 14.9 ng/mL, and perfluoropentanoic acid (PFPeA) was predominant. The PFOS (p < 0.005) concentration was higher in the serum of children than that of Korean adults aged 20–29. Some of the PFC concentrations in the serum correlated negatively with body mass index and tended to increase with the duration of breastfeeding. However, there were no gender-specific differences in the PFC concentrations and no correlations between PFC concentrations in serum and urine.
اظهر المزيد [+] اقل [-]Impact of solar UV radiation on toxicity of ZnO nanoparticles through photocatalytic reactive oxygen species (ROS) generation and photo-induced dissolution النص الكامل
2014
Ma, Hongbo | Wallis, Lindsay K. | Diamond, Steve | Li, Shibin | Canas-Carrell, Jaclyn | Parra, Amanda
The present study investigated the impact of solar UV radiation on ZnO nanoparticle toxicity through photocatalytic ROS generation and photo-induced dissolution. Toxicity of ZnO nanoparticles to Daphnia magna was examined under laboratory light versus simulated solar UV radiation (SSR). Photocatalytic ROS generation and particle dissolution were measured on a time-course basis. Two toxicity mitigation assays using CaCl2 and N-acetylcysteine were performed to differentiate the relative importance of these two modes of action. Enhanced ZnO nanoparticle toxicity under SSR was in parallel with photocatalytic ROS generation and enhanced particle dissolution. Toxicity mitigation by CaCl2 to a less extent under SSR than under lab light demonstrates the role of ROS generation in ZnO toxicity. Toxicity mitigation by N-acetylcysteine under both irradiation conditions confirms the role of particle dissolution and ROS generation. These findings demonstrate the importance of considering environmental solar UV radiation when assessing ZnO nanoparticle toxicity and risk in aquatic systems.
اظهر المزيد [+] اقل [-]Landscape parameters driving aquatic pesticide exposure and effects النص الكامل
2014
Bunzel, Katja | Liess, Matthias | Kattwinkel, Mira
Pesticide contamination is considered one of the reasons streams fail to achieve good ecological and chemical status, the main objectives of the Water Framework Directive. However, little is known on the interaction of different pesticide sources and landscape parameters and the resulting impairment of macroinvertebrate communities. We evaluated the potential effects of diffuse and point sources of pesticides using macroinvertebrate monitoring data from 663 sites in central Germany. Additionally, we investigated forested upstream reaches and structural quality as landscape parameters potentially mitigating or amplifying the effects of pesticides. Diffuse pesticide pollution and forested upstream reaches were the most important parameters affecting macroinvertebrate communities (pesticide-specific indicator SPEARpesticides). Our results indicate that forested upstream reaches and riparian buffer strips at least 5 m in width can mitigate the effects and exposure of pesticides. In addition, we developed a screening approach that allows an initial, cost-effective identification of sites of concern.
اظهر المزيد [+] اقل [-]Major sources of MeO/OH-BDEs in the East China Sea elucidated from their records and phytoplankton biomarkers النص الكامل
2014
Fan, Ying | Huh, Chih-An | Lan, Jing | Zhao, Meixun | Zhao, Zongshan | Li, Guoliang | Sun, Jianteng | Jiang, Guibin
Hydroxylated (OH-) and methoxylated (MeO-) polybrominated diphenyl ethers (PBDEs) have caused much concern because of their potential toxicity and worldwide distribution. These compounds are recently suggested to originate from the natural process in the ocean. However, their source remains highly controversial. In this study, we analyzed the contents of nine MeO-BDEs, ten OH-BDEs, and phytoplankton biomarkers (PBs) in two sediment cores collected from the East China Sea (ECS). The detection of 6-MeO-BDE-47, 2′-MeO-BDE-68, and 6-OH-BDE-47 have been reported since the 1920s, prior to the production of PBDEs. Significant relations were found between MeO/OH-BDEs and indicators of marine organic matters. The similar down-core variations and significant correlations between MeO/OH-BDEs and PBs suggest the possibility that phytoplankton produced these natural compounds. Laboratory incubation further demonstrates that phytoplankton can produce MeO-BDEs. Comparisons between the content ratios of 6-MeO-BDE-47/2′-MeO-BDE-68 and brassicasterol/dinosterol indicate that the signature of MeO-BDEs is controlled by the phytoplankton community structure.
اظهر المزيد [+] اقل [-]Wide-range particle characterization and elemental concentration in Beijing aerosol during the 2013 Spring Festival النص الكامل
2014
Jing, Hui | Li, Yu-Feng | Zhao, Jiating | Li, Bai | Sun, Jialong | Chen, Rui | Gao, Yuxi | Chen, Chunying
The number and mass concentration, size distribution, and the concentration of 16 elements were studied in aerosol samples during the Spring Festival celebrations in 2013 in Beijing, China. Both the number and mass concentration increased sharply in a wide range from 10 nm to 10 μm during the firecrackers and fireworks activities. The prominent increase of the number concentration was in 50 nm–500 nm with a peak of 1.7 × 105/cm3 at 150 nm, which is 8 times higher than that after 1.5 h. The highest mass concentration was in 320–560 nm, which is 4 times higher than the control. K, Mg, Sr, Ba and Pb increased sharply during the firework activities in PM10. Although the aerosol emission from firework activities is a short-term air quality degradation event, there may be a substantial hazard arising from the chemical composition of the emitted particles.
اظهر المزيد [+] اقل [-]Estimating urban roadside emissions with an atmospheric dispersion model based on in-field measurements النص الكامل
2014
Pu, Yichao | Yang, Chao
Urban vehicle emission models have been utilized to calculate pollutant concentrations at both microscopic and macroscopic levels based on vehicle emission rates which few researches have been able to validate. The objective of our research is to estimate urban roadside emissions and calibrate it with in-field measurement data. We calculated the vehicle emissions based on localized emission rates, and used an atmospheric dispersion model to estimate roadside emissions. A non-linear regression model was applied to calibrate the localized emission rates using in-field measurement data. With the calibrated emission rates, emissions on urban roadside can be estimated with a high accuracy.
اظهر المزيد [+] اقل [-]Identification of lead sources in residential environments: Sydney Australia النص الكامل
2014
Laidlaw, M.A.S. | Zahran, S. | Pingitore, N. | Clague, J. | Devlin, G. | Taylor, M.P.
Interior and exterior dust, soil and paint were analysed at five brick urban Sydney homes over 15 months to evaluate temporal variations and discriminate sources of lead (Pb) exposure. Exterior dust gauge Pb loading rates (μg/m2/28 days), interior vacuum dust Pb concentrations (mg/kg) and interior petri-dish Pb loading rates (μg/m2/28 days), were correlated positively with soil Pb concentrations. Exterior dust gauge Pb loading rates and interior vacuum dust Pb concentrations peaked in the summer. Lead isotope and Pb speciation (XAS) were analysed in soil and vacuum dust samples from three of the five houses that had elevated Pb concentrations. Results show that the source of interior dust lead was primarily from soil in two of the three houses and from soil and Pb paint in the third home. IEUBK child blood Pb modelling predicts that children's blood Pb levels could exceed 5 μg/dL in two of the five houses.
اظهر المزيد [+] اقل [-]Low mercury levels in marine fish from estuarine and coastal environments in southern China النص الكامل
2014
Pan, Ke | Chan, Heidi | Tam, Yin Ki | Wang, Wen-Xiong
This study is the first comprehensive evaluation of total Hg and methylmercury (MeHg) concentrations in wild marine fish from an estuarine and a coastal ecosystem in southern China. A total of 571 fish from 54 different species were examined. Our results showed that the Hg levels were generally low in the fish, and the Hg levels were below 30 ng g−1 (wet weight) for 82% of the samples, which may be related to the reduced size of the fish and altered food web structure due to overfishing. Decreased coastal wetland coverage and different carbon sources may be responsible for the habitat-specific Hg concentrations. The degree of biomagnification was relatively low in the two systems.
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