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81.
The Arctic has become a sink for persistent organic pollutants (POPs) originating from lower latitudes, and relatively high levels have been found in different biota. Recent studies have identified detrimental effects on wildlife including endocrine disruption, impairment of enzyme activity, and reduced immune function. The Arctic spider crab, Hyas araneus, shown interesting potential for its use as sentinel organism in polar ecosystems. This study investigated the effect of 2,2',4,4'-tetra bromo diphenyl ether (BPDE), bisphenol A (BPA), and diallyl phthalte (DPA) on H. araneus in a three weeks exposure study. Expression of multixenibiotic resistance (MXR) proteins has been studied using the C219 monoclonal antibody which allows identifying an immunoreactive protein of 40 kDa in the digestive gland while no such protein could be observed in the gills. Expression of this protein was increased by exposure to DPA (+75%; p<0.05, n=10). All compounds significantly affected muscle acetylcholine esterase (AChE) activity (p<0.05, n=10) with 50 microg/L DPA having the strongest effect by lowering the value to 37% of control. The total oxyradical scavenging capacity measured in the digestive gland toward peroxyl, hydroxyl and peroxynitrite was also significantly reduced indicating a decreased resistance to oxidative stress generated by DPA (p<0.05, n=5). These results thus suggest the potential detrimental effects of DPA even at concentration as low as 50 microg/L on H. araneus. 相似文献
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A. L. Graham M. Christophe Michel-Levy J. Danon A. J. Easton 《Meteoritics & planetary science》1988,23(4):321-323
Abstract— The Tuxtuac meteorite fell in Zacatecas state, Mexico, on 16 October 1975, at 1820 hours. Two partly crusted masses, weighing 1924 g and 2340 g, were recovered. The stone is an ordinary chondrite, LL5, with olivine Fa30 and 19.22 weight % total iron. The silicates contain numerous voids and a froth-like mesostasis is present within some chondrules. Metal phases present are kamacite (5.7–6.4% Ni, 6–7% Co) and high nickel metal (taenite 37–41% Ni, 1.7 ± 0.3% Co; tetrataenite 47–52% Ni, 0.8–1.4% Co). The stone is unusual for an LL-group chondrite in that it exhibits neither large-scale brecciation features nor dark veins. 相似文献
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This paper describes the design and development of an experimental GIS prototype that may be used to assist experienced pilots, student pilots and flight instructors for post-flight evaluation of navigation performance. The system is developed as a GIS experimental application which employs geographical data derived from the Digital Chart of the World integrated with airspace data derived from the ICAO 1:500,000 Aeronautical Chart. Real-time data are collected and integrated within a monitoring computing environment from external sensors which include GPS, altitude and relative motion sensors. This enables the generation of multi-layered digital maps and navigation data capable of being rapidly re-configured to enhance visualization by abstraction. The integration of real time navigation data with geographical data facilitates airborne decision-making, cockpit management, and makes a valuable contribution to flight safety. 相似文献
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Renaud Tutundjian Christophe Minier Frank Le Foll Franois Leboulenger 《Marine environmental research》2002,54(3-5)
Cellular detoxification by direct processes has been investigated in fish by studying the ability of hepatocytes prepared from juvenile aquarium-reared turbot (Scophthalmus maximus) to actively exclude the fluorescent dye rhodamine B (RB). Cell viability was studied by measurements of non-specific esterase activity using fluorescein diacetate. This revealed that turbot hepatocytes can be cultured for a few days with a viability decreasing to 38% after 24 h. The 24-h cultured cells have been used to study the rhodamine B exclusion activity using confocal laser microscopy. Hepatocytes accumulated the dye in a competitive manner with verapamil, thus suggesting that they express a transport system similar to the P-glycoprotein-mediated multixenobiotic resistance process. Incubation of cells with 1 μM RB and 20 μM verapamil led to a 26% increase of cellular fluorescence as compared to the accumulation in absence of competitor. Rhodamine B accumulated in the whole cytoplasm, with more concentrated areas that might correspond to the lysosomal compartment and the cell membrane. 相似文献
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Cellular detoxification by direct processes has been investigated in fish by studying the ability of hepatocytes prepared from juvenile aquarium-reared turbot (Scophthalmus maximus) to actively exclude the fluorescent dye rhodamine B (RB). Cell viability was studied by measurements of non-specific esterase activity using fluorescein diacetate. This revealed that turbot hepatocytes can be cultured for a few days with a viability decreasing to 38% after 24 h. The 24-h cultured cells have been used to study the rhodamine B exclusion activity using confocal laser microscopy. Hepatocytes accumulated the dye in a competitive manner with verapamil, thus suggesting that they express a transport system similar to the P-glycoprotein-mediated multixenobiotic resistance process. Incubation of cells with 1 microM RB and 20 microM verapamil led to a 26% increase of cellular fluorescence as compared to the accumulation in absence of competitor. Rhodamine B accumulated in the whole cytoplasm, with more concentrated areas that might correspond to the lysosomal compartment and the cell membrane. 相似文献