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111.
The histochemical measurement of urea-resistant alkaline phosphatase from maternal blood neutrophils is known to have a high detection rate for the prenatal detection of Down's syndrome pregnancies. However, because the histochemical method is laborious and subjective to use, it has not gained widespread acceptance in prenatal screening programmes. We present a simple and objective method for the measurement of urea-resistant alkaline phosphatase by flow cytometry. The method should allow the design of larger studies aimed at evaluating the role of neutrophil urea-resistant alkaline phosphatase in the prenatal screening for Down's syndrome.  相似文献   
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Mitigation and Adaptation Strategies for Global Change - Guidelines of the Intergovernmental Panel on Climate Change (IPCC) were used to assess a greenhouse gas inventory for land use change and...  相似文献   
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In recent years several hitherto unknown types of celestial objects related to star formation and early stellar evolution have been discovered by infrared and radio observations. New stars are born within large and massive interstellar molecular clouds. The onset of star formation in these clouds seems to be triggered by external forces.  相似文献   
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There is a consensus within the scientific community that sediments act as a long-term sink for a variety of organic and inorganic pollutants, which, however, can re-enter the water column upon resuspension of deposited material under certain hydraulic conditions such as flood events. Within the implementation of the European Water Framework Directive, it is important to understand the potential short- and long-term impact of suspended particulate matter (SPM)-associated contaminants on aquatic organisms as well as the related uptake mechanisms for a sound risk assessment. To elucidate the effects of sediment-bound organic pollutants, such as polycyclic aromatic hydrocarbons (PAHs), rainbow trout (Oncorhynchus mykiss) were exposed to three resuspended natural sediments with different contamination levels. Physicochemical parameters including dissolved oxygen concentration, pH and temperature, total PAH concentration in sediments and SPM as well as different biomarkers of exposure in fish (7-ethoxyresorufin O-deethylase activity, biliary PAH metabolites, micronuclei, and lipid peroxidation) were measured following seven days of exposure within an annular flume, a device to assess erosion and deposition processes of cohesive sediment. Concentrations of PAHs in SPM remained constant and represented the different contamination levels in the un-suspended sediments. Significant differences in bile metabolite concentrations as well as in 7-ethoxyresorufin O-deethylase induction compared to control experiments (untreated animals and animals that were exposed in the annular flume without sediment) were observed for all exposure scenarios. The ratio between 1-hydroxypyrene in bile from fish exposed to the three different contamination levels was 1.0:3.6:10.7 and correlated well with (1) the ratio of pyrene concentrations in corresponding sediments which was 1.0:3.1:12.7 and (2) with the ratio of particle-bound pyrene in SPM which was 1.0:2.7:11.7. In contrast, hepatic lipid peroxidation and micronuclei formation represented the different contamination levels less conclusive. The results of this study clearly demonstrate that firmly bound PAH from aged sediments can become bioaccessible upon resuspension under flood-like conditions and are readily absorbed by aquatic organisms such as rainbow trout. Associated short-term effects were clearly documented and possible adverse long-term impacts due to genotoxicity are likely to follow.  相似文献   
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Fuels derived from non-petroleum renewable resources have raised interest due to their potential in replacing petroleum-based fuels, but information on their fate and effects in the terrestrial and aquatic environments in accidental spill scenario is limited. In this study, migration of four fuels (conventional diesel, conventional gasoline, renewable diesel NExBTL, and ethanol-blended gasoline RE85 containing maximum 85 % ethanol) as non-aqueous phase liquids (NAPL) in soil was demonstrated in a laboratory-scale experiment. Ecotoxicity data was produced for the same fuels. There was no significant difference in migration of conventional and renewable diesel, but gasoline migrated 1.5 times deeper and 7–9 times faster in sand than diesel. RE85 spread horizontally wider but not as deep (p?Eisenia fetida followed by ethanol-blended gasoline (LC50 1,643 mg/kg THC) and conventional diesel (LC50 2,432 mg/kg THC), although gasoline evaporated fast from soil. For comparison, the toxicity of the water-accommodated fractions (WAF) of the fuels was tested with water flea Daphnia magna and Vibrio fischeri, also demonstrating groundwater toxicity. The WAF of conventional gasoline and RE85 showed almost similar toxicity to both the aquatic test species. EC50 values of 1:10 (by volume) WAF were 9.9 %WAF (gasoline) and 9.3 %WAF (RE85) to D. magna and 9.3 %WAF (gasoline) and 12.3 %WAF (RE85) to V. fischeri. Low solubility decreased toxicity potential of conventional diesel in aquatic environment, but direct physical effects of oil phase pose a threat to organisms in nature. Renewable diesel NExBTL did not show clear toxicity to any test species.  相似文献   
119.
Estonia is currently one of the leading producers of shale oils in the world. Increased production, transportation and use of shale oils entail risks of environmental contamination. This paper studies the behaviour of two shale fuel oils (SFOs)—‘VKG D’ and ‘VKG sweet’—in different soil matrices under natural climatic conditions. Dynamics of SFOs’ hydrocarbons (C10–C40), 16 PAHs, and a number of soil heterotrophic bacteria in oil-spiked soils was investigated during the long-term (1 year) outdoor experiment. In parallel, toxicity of aqueous leachates of oil-spiked soils to aquatic organisms (crustaceans Daphnia magna and Thamnocephalus platyurus and marine bacteria Vibrio fischeri) and terrestrial plants (Sinapis alba and Hordeum vulgare) was evaluated. Our data showed that in temperate climate conditions, the degradation of SFOs in the oil-contaminated soils was very slow: after 1 year of treatment, the decrease of total hydrocarbons’ content in the soil did not exceed 25 %. In spite of the comparable chemical composition of the two studied SFOs, the VKG sweet posed higher hazard to the environment than the heavier fraction (VKG D) due to its higher mobility in the soil as well as higher toxicity to aquatic and terrestrial species. Our study demonstrated that the correlation between chemical parameters (such as total hydrocarbons or total PAHs) widely used for the evaluation of the soil pollution levels and corresponding toxicity to aquatic and terrestrial organisms was weak.  相似文献   
120.
An Erratum has been published for this article in Prenatal Diagnosis 21(7) 2001, 605. Prenatal diagnosis (PD) of fetal cytomegalovirus (CMV) infection was performed in 242 pregnancies, with known outcome in 189 cases. In 141/189 pregnancies, PD was carried out on account of suspicious maternal CMV serology up to gestational week (WG) 23, and in 48 cases on account of abnormal ultrasonic findings detected between WG 18 and 39. Chorionic villus samples (n=6), amniotic fluid (AF, n=176) and/or fetal blood specimens (n=80) were investigated for detection of virus by cell culture, shell vial assay, PCR and/or CMV-specific IgM antibodies. Of 189 fetuses correctly evaluated by CMV detection either in fetal tissue following therapeutic abortion/stillbirth (n=24) or in urine of neonates within the first 2 weeks of life (n=33), 57 were congenitally infected. In women with proven or suspected primary infection, the intrauterine transmission rates were 20.6% (7/34) and 24.4% (10/41), respectively. Of the congenitally infected live-born infants, 57.6% (19/33) had symptoms of varying degree. The overall sensitivity of PD in the serologic and ultrasound risk groups was 89.5% (51/57). A sensitivity of 100% was achieved by combining detection of CMV-DNA and CMV-specific IgM in fetal blood or by combined testing of AF and fetal blood for CMV-DNA or IgM antibodies. There was no instance of intrauterine death following the invasive procedure. The predictive value of PD for fetal infection was 95.7% (132/138) for negative results and 100% (51/51) for positive results. Correct results for congenital CMV infection by testing AF samples can be expected with samples obtained after WG 21 and after a time interval of at least 6 weeks between first diagnosis of maternal infection and PD. In case of negative findings in AF or fetal blood and the absence of ultrasound abnormalities at WG 22–23, fetal infection and neonatal disease could be excluded with high confidence. Positive findings for CMV infection in AF and/or fetal blood in combination with CMV suspicious ultrasound abnormalities predicted a high risk of cytomegalic inclusion disease (CID). Furthermore, detection of specific IgM antibodies in fetal blood was significantly correlated with severe outcome for the fetus or the newborn (p=0.0224). However, normal ultrasound of infected fetuses at WG 22–23 can neither completely exclude an abnormal ultrasound at a later WG and the birth of a severely damaged child nor the birth of neonates which are afflicted by single manifestations at birth or later and of the kind which are not detectable by currently available ultrasonographic techniques. Copyright © 2001 John Wiley & Sons, Ltd.  相似文献   
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