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Determination of triazines herbicides (atrazine and simazine) by high performance liquid chromatography (HPLC) in samples of trophic chain were worked out. Determination limits of 0.5 μg g−1 for atrazine, 0.8 μg g−1 for simazine with pesticides recovery of 70–77% in trophic chain samples were obtained. The content of simazine in soils was in range 1.72–57.89 μg g−1, in grass 5–88 μg g−1, in milk 2.32–15.29 μg g−1, in cereals 10.98–387 μg g−1, in eggs 30.14–59.48 μg g−1, for fruits: 2.45–6.19 μg g−1. The content of atrazine in soils was in range 0.69–19.59 μg g−1, in grass 7.85–23.85 μg g−1, in cereals 1.88–43.08 μg g−1. Cadmium, lead and zinc were determined by inductively coupled plasma atomic emission spectrometry (ICP-AES) in the same samples as atrazine and simazine. Determination limits for cadmium 5 × 10−3 μg g−1, for lead 1 × 10−2 μg g−1, and for zinc 0.2 × 10−3 μg g−1, were obtained. The content of cadmium in soil was in range 0.13–5.89 μg g−1, in grass 114–627.72 × 10−3 μg g−1, in milk 8.88–61.88 × 10−3 μg g−1, in cereals 0.20–0.31 μg g−1, in eggs 0.11–0.15 μg g−1, in fruits 0.23–0.59 μg g−1. The content of lead in soils was in range 0.57–151.50 μg g−1, in grass 0.16–136.57 μg g−1, in milk 1.16–3.74 μg g−1, in cereals 1.05–5.47 μg g−1, in eggs 5.79–55.87 μg g−1, in fruits 21.00–87.36 μg g−1. Zinc content in soil was in range 9.15–424.5 μg g−1, in grass 35.20–55.87 μg g−1, in milk 20.00–34.38 μg g−1, in cereals 14.94–28.78 μg g−1, in eggs 15.67–32.01 μg g−1, in fruits 14.94–18.88 μg g−1.

Described below extraction and mineralization methods for particular trophic chains allowed to determine of atrazine, simazine, cadmium, lead and zinc with good repeatability and precision. Emphasis was focused on liquid–liquid extraction and solid-phase extraction of atrazine and simazine from analysed materials, as well as, on monitoring the content of herbicides and metals in soil and along trophic chain. Higher concentration of pesticides in samples from west region of Poland in comparison to that of east region is likely related to common applying them in Western Europe in relation to East Europe. The content of metals strongly depends on samples origin (industry area, vicinity of motorways).  相似文献   

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In multiphase systems capillary pressures play a significant role on fluid movement and retention. The facility to predict the effect of different thermal remediation strategies requires the knowledge of the effect of temperature on capillary pressure-saturation relationships in the soils. The objective of recent study was (a) to develop a technique for routinely measuring the pressure-saturation curves of soil samples saturated with a nonpolar liquid at different regulated temperatures (b) to build a database using the measured pressure-saturation curves and the physical, chemical properties of the model soils (c) to establish the dependence of nonaqueous phase liquid retention on the soil properties and the temperature. The retention curves (extraction isotherms) with nonaqueous phase liquid were determined using a modified pressure plate extractor. The wetting phase was a non-aromatic hydrocarbon distillation product. Pressure plates were designed and constructed in the laboratory of our department. The temperature was held constant at 20, 40 and 60 C. Statistical analysis was performed involving selected soil parameters and the measured nonaqueous phase liquid retention data. The results show that knowing some easily measurable soil parameters (bulk density, particle size distribution, humus and lime content) we can estimate the nonaqueous phase liquid retention of the soils. The measured “extraction isotherms” provide essential information about the temperature-dependency of pressure-saturation curves.  相似文献   
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Abstract

The use of electronic cigarettes increases as a supposedly healthier form of nicotine consumption, but safety of vaping remains uncertain. In this study, we assessed whether the use of electronic cigarettes increases the risk of infertility in male rats. Malformations of sperm morphology were more frequent in nicotine-exposed groups than in the control group. Vacuolization of seminiferous epithelium, reduction of spermatogenesis, increased apoptosis of spermatogonia and spermatocytes, and acceleration of degeneration of testes were observed. The male reproductive organs are slightly less affected by vaping than by smoking. Nevertheless, in consequence both may lead to the reduction of fertility.  相似文献   
206.
Electronic tags were used to examine the biology of Atlantic bluefin tuna (Thunnus thynnus L.) on their breeding grounds in the Gulf of Mexico (GOM). The hypothesis that movement patterns, diving behavior, and thermal biology change during different stages of the breeding migration was tested. Mature Atlantic bluefin tuna tagged in the western Atlantic and the GOM, were on their breeding grounds from February to June for an average of 39 ± 11 days. The bluefin tuna experienced significantly warmer mean sea surface temperatures (SSTs) within the GOM (26.4 ± 1.6°C) than outside the GOM (20.2 ± 1.9°C). As the bluefin tuna entered and exited the GOM, the fish dove to daily maximum depths of 568 ± 50 and 580 ± 144 m, respectively, and exhibited directed movement paths to and from the localized breeding areas. During the putative breeding phase, the bluefin tuna had significantly shallower daily maximum depths (203 ± 76 m), and exhibited shallow oscillatory dives during the night. The movement paths of the bluefin tuna during the breeding phase were significantly more residential and sinuous. The heat transfer coefficients (K) were calculated for a bluefin tuna in the GOM using the recorded ambient and body temperatures. The K for this fish increased rapidly at the high ambient temperatures encountered in the GOM, and was significantly higher at night in the breeding phase when the fish was exhibiting shallow oscillatory dives. This suggests that the fish were behaviorally and physiologically thermoregulating in the Gulf of Mexico. This study demonstrates that the movement patterns, diving behavior, and thermal biology of Atlantic bluefin tuna change significantly at different stages of the breeding migration and can be used to define spawning location and timing. Electronic supplementary material Supplementary material is available in the online version of this article at and is accessible for authorized users.  相似文献   
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In recent years the issue of the municipal waste in Poland has become increasingly topical, with a considerable rise in the waste generation, much of which can be attributed to a boom in product packaging (mainly plastic). The annual production of plastics packaging has been constantly increasing over the last 20 to 30 years, and now exceeds 3.7 million tons. Due to a lack of processing technologies and poorly developed selective segregation system, packaging waste is still treated as a part of the municipal solid waste (MSW) stream, most of which is landfilled. As a result of Poland's access to the European Union, previous legal regulations governing municipal waste management have been harmonized with those binding on the member countries. One of the main changes, the most revolutionary one, is to make entrepreneurs liable for environmental risks resulting from the introduction of packaging to the market, and for its recycling. In practice, all entrepreneurs are to ensure recovery, and recycling, of used packaging from products introduced to the market at the required level. In recent year, the required recycling levels were fulfilled for all types of materials but mainly by large institutions using grouped and transport packaging waste for that matter. Household packaging gathered in the selective segregation system at the municipalities was practically left alone. This paper is an attempt to describe the system and assess the first year of functioning of the new, revamped system of packaging waste management in Poland. Recommendations are made relating to those features that need to be included in packaging waste management systems in order to maximize their sustainability and harmonization with the EU legal system.  相似文献   
208.
Mein Dank gilt Prof. O. Björkman für einen außerordentlich anregenden und lehrreichen Aufenthalt an der Carnegie Institution in Stanford (Californien) sowie Prof. O. L. Lange, Prof. K. Winter und Prof. F.-C. Czygan für die Möglichkeit, die anschließenden Untersuchungen in Würzburg durchzuführen. Für finanzielle Unterstützung danke ich der McKnight Foundation, der Carnegie Corporation und ganz besonders der Deutschen Forschungsgemeinschaft.  相似文献   
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