1. Pharmacokinetics of acetylsalicylic acid (ASA) and sodium salicylate (SS) were assessed following single intravenous (i.v.) and oral administration at doses of 50 mg/kg body weight to chickens and turkeys. Plasma drug concentrations were determined using high-performance liquid chromatography with ultraviolet detection and pharmacokinetic variables were calculated using a non-compartmental model.
2. The mean residence time (MRT) of salicylate (SA) after i.v. administration of SS was 6.08 ± 0.59 and 3.32 ± 0.27 h and after oral administration was 6.95 ± 0.72 and 4.55 ± 0.71 h in chickens and turkeys, respectively. The elimination half-life (T1/2 e) was shorter in turkeys compared with chickens. The value of body clearance (ClB) was higher in turkeys than in chickens, but the apparent volume of distribution (Vss) was similarly low in both species. The bioavailability of SS was complete and the maximal plasma concentration of SA (Cmax) after oral administration was 96.93 ± 8.06 and 91.76 ± 9.64 µg/ml, respectively, in chickens and turkeys.
3. The MRT of ASA after iv administration was 0.24 ± 0.08 and 0.24 ± 0.02 h and after oral administration was 0.78 ± 0.25 and 0.59 ± 0.13 h, respectively, in chickens and turkeys. In both species, T1/2 e was very short, ClB and Vss were similar and markedly higher than those of salicylate. The bioavailability of unchanged ASA was low and Cmax after oral administration was 6.9 ± 3.6 µg/ml in chickens and 8.6 ± 1.3 µg/ml in turkeys. 相似文献
Journal of Soils and Sediments - Knowledge about the spatio-temporal variability of soil microbial properties is crucial in evaluating their structure-function relationship and their impact on... 相似文献
Plant Foods for Human Nutrition - This study analysed fruits of cranberry cultivars: Ben Lear, Bergman, Early Richard, Pilgrim and Stevens and compared them with wild-grown cranberry fruits. The... 相似文献
Background, aim, and scope Fertilization is an important agricultural practice for increasing crop yields. In order to maintain the soil sustainability,
it is important to monitor the effects of fertilizer applications on the shifts of soil microorganisms, which control the
cycling of many nutrients in the soil. Here, culture-dependent and culture-independent approaches were used to analyze the
soil bacterial and fungal quantities and community structure under seven fertilization treatments, including Control, Manure,
Return (harvested peanut straw was returned to the plot), and chemical fertilizers of NPK, NP, NK, and PK. The objective of
this study was to examine the effects on soil microbial composition and diversity of long-term organic and chemical fertilizer
regimes in a Chinese upland red soil.
Materials and methods Soil samples were collected from a long-term experiment station at Yingtan (28°15′N, 116°55′E), Jiangxi Province of China.
The soil samples (0–20 cm) from four individual plots per treatment were collected. The total numbers of culturable bacteria
and fungi were determined as colony forming units (CFUs) and selected colonies were identified on agar plates by dilution
plate methods. Moreover, soil DNAs were extracted and bacterial 16S rRNA genes and fungal 18S rRNA genes were polymerase chain
reaction amplified, and then analyzed by denaturing gradient gel electrophoresis (DGGE), cloning, and sequencing.
Results The organic fertilizers, especially manure, induced the least culturable bacterial CFUs, but the highest bacterial diversity
ascertained by DGGE banding patterns. Chemical fertilizers, on the other hand, had less effect on the bacterial composition
and diversity, with the NK treatment having the lowest CFUs. For the fungal community, the manure treatment had the largest
CFUs but much fewer DGGE bands, also with the NK treatment having the lowest CFUs. The conventional identification of representative
bacterial and fungal genera showed that long-term fertilization treatments resulted in differences in soil microbial composition
and diversity. In particular, 42.4% of the identified bacterial isolates were classified into members of Arthrobacter. For fungi, Aspergillus, Penicillium, and Mucor were the most prevalent three genera, which accounted for 46.6% of the total identified fungi. The long-term fertilization
treatments resulted in different bacterial and fungal compositions ascertained by the culture-dependent and also the culture-independent
approaches.
Discussion It was evident that more representative fungal genera appeared in organic treatments than other treatments, indicating that
culturable fungi were more sensitive to organic than to chemical fertilizers. A very notable finding was that fungal CFUs
appeared maximal in organic manure treatments. This was quite different from the bacterial CFUs in the manure, indicating
that bacteria and fungi responded differently to the fertilization. Similar to bacteria, the minimum fungal CFUs were also
observed in the NK treatment. This result provided evidence that phosphorus could be a key factor for microorganisms in the
soil. Thus, despite the fact that culture-dependent techniques are not ideal for studies of the composition of natural microbial
communities when used alone, they provide one of the more useful means of understanding the growth habit, development, and
potential function of microorganisms from soil habitats. A combination of culture-dependent and culture-independent approaches
is likely to reveal more complete information regarding the composition of soil microbial communities.
Conclusions Long-term fertilization had great effects on the soil bacterial and fungal communities. Organic fertilizer applications induced
the least culturable bacterial CFUs but the highest bacterial diversity, while chemical fertilizer applications had less impact
on soil bacterial community. The largest fungal CFUs were obtained, but much lower diversity was detected in the manure treatment.
The lowest bacterial and also fungal CFUs were observed in the NK treatment. The long-term fertilization treatments resulted
in different bacterial and fungal compositions ascertained by the culture-dependent and also the culture-independent approaches.
Phosphorus fertilizer could be considered as a key factor to control the microbial CFUs and diversity in this Chinese upland
red soil.
Recommendations and perspectives Soil fungi seem to be a more sensitive indicator of soil fertility than soil bacteria. Since the major limitation of molecular
methods in soil microbial studies is the lack of discrimination between the living and dead, or active and dormant microorganisms,
both culture-dependent and culture-independent methods should be used to appropriately characterize soil microbial diversity. 相似文献
Background, aim, and scope Vegetation stress diagnoses based on plant sampling and physiochemical analysis using traditional methods are commonly time-consuming,
destructive and expensive. The measurement of field spectral reflectance is one basis of airborne or spaceborne remote sensing
monitoring.
Materials and methods In this study, paddy plants were grown in the barrels evenly filled with 10.0 kg soil that was mixed respectively with 0,
2.5 × 207.2 and 5.0 × 207.2 mg Pb per 1,000 g soil. Rice canopy spectra were gathered by mobile hyper-spectral radiometer
(ASD FieldSpec Pro FR, USA). Meanwhile, canopy leaves in the field-of-view (FOV) of spectroradiometer were collected and then
prepared in the laboratory, (1) for chlorophyll measurement by Model 721 spectrophotometer, and (2) for Pb determination by
atomic absorption spectrophotometer (SpectraAA-220FS).
Results and discussion Canopy spectral reflectance in the region of visible-to-near-infrared light (VNIR) increased, because ascended Pb concentration
caused the decrease of canopy chlorophyll content. In the agro-ecosystem, however, heavy metal contamination is presented
typically as mixture and their interactions strongly affect actually occurring effects. Normalized spectral absorption depth
(Dn), and shifting distance (DS) of red edge position (REPs) revealed the differences in Pb concentration for canopy leaves,
especially at the early tillering stage. Due to insufficient biomass of rice plants, the 30th day was not reliable enough
for the selection of crucial growth stages. Some special sensitive bands might be omitted at the same time because of limited
sample sets.
Conclusions Our initial experiments are still too few in the amounts of both metals and plants neither to build accurate prediction models
nor to discuss the transformation from ground to air/spaceborne remote sensing. However, we are pleased to communicate that
ground remote sensing measurements would provide reliable information for the estimation of Pb concentration in rice plants
at the early tillering stage when proper features (such as DS and Dn) of reflectance spectra are applied.
Recommendations and perspectives Hyper-spectral remote sensing is a potential and promising technology for monitoring environmental stresses on agricultural
vegetation. Further ground remote sensing experiments are necessary to evaluate the possibility of hyper-spectral reflectance
spectroscopy in monitoring different kinds of metals’ stress on various plants. 相似文献
Background, aims, and scope Embankment of meandering river systems in many industrial areas results in the formation of artificial oxbow lakes that may
act as perennial or intermittent traps for river sediments. Their deposits can be dated using a combination of historical
and stratigraphic data, providing a good means to study historical records of contamination transported by rivers. Contamination
history over the last few decades is of special significance for Central and Eastern Europe as it can reflect high pollutant
levels in the second half of the twentieth century and the subsequent improvement after the fall of the Iron Curtain. The
purpose of this study was to investigate recent sediments of an oxbow lake of the Morava River, Czech Republic, their stratigraphic
records, sediment architecture, and history of contamination.
Materials and methods Seven ground-penetrating radar (GPR) profiles and three sediment cores up to 4 m deep were studied. The stratigraphy of the
cores was inferred from visible-light spectrophotometry, X-ray radiography, grain size analysis, and semiquantitative modal
analysis of sandy fractions. The sediments were dated using the 137Cs mass activity and combinations of stratigraphic and historical data. The cores were sampled for concentrations of heavy
metals and persistent organic pollutants. Wet sampled, lyophilized, and sieved sediments were extracted and analyzed for heavy
metals by inductively coupled plasma mass spectrometry (ICP-MS) of aqua regia leachate and for persistent organic pollutants
by gas chromatography (GC-ECD and GC-MS).
Results Three distinct sedimentary sequences (S1, S2, and S3) were identified. The basal sequence S1 represents river channel sediments
deposited before the formation of the oxbow lake, most likely before the 1930s. The boundary between the S1 and S2 sequence
correlates with the level of sediment dredging from 1981 evidenced from historical data. The overlying sequences S2 and S3
represent a postdredging sediment wedge, which progrades into the lake. 137Cs dating revealed a distinct Chernobyl 1986 peak at ∼150 cm depth inferring sedimentation rates up to 7.7 cm/year. Sediment
contamination abruptly increased from the pre-1930s deposits to the post-1981 deposits. The concentration levels increased
two to five times for Pb, As, Zn, and Cu, about 10 to 15 times for Cr, Sb, and Hg, up to 34 times for Cd, and 25 to 67 times
for DDTs, PCBs, and PAHs. The concentrations of most contaminants remained approximately constant until the late 1980s when
they started to decrease slowly. The decreasing trends were most prominent for heavy metals and anthracene, less prominent
for DDTs, and almost absent for PCBs and most PAHs.
Discussion Different temporal and spatial patterns for various contaminants make it possible to distinguish between anthropogenic point
sources from local industry (anthracene, Cr, Cd), possible diffuse sources (most PAHs), and geological background (V, Co,
Ni, and Mo). The observed recent trends in heavy metal and persistent organic pollutant contamination are generally consistent
with data from other Central European rivers. The roughly balanced contamination levels in sediments from the lake and the
adjacent river channel suggest that the oxbow lake deposits reflect immediate levels of the contamination bound to suspended
particulate matter passing through the river.
Conclusions The investigated oxbow lake accumulated suspended sediment from Morava River, developing a thick sedimentary body. The sediments
offer a good time framework to study historical contamination of the river on a decade time scale. Continuous contamination
trends can be traced back to the early 1980s. The results show that stratigraphic analysis of cores has a good potential for
identification of uninterrupted historical trends and unconformities, e.g., due to dredging.
Recommendations and perspectives Oxbow lakes may provide an alternative to floodplains and reservoir deposits when studying river contamination history. High
sedimentation rates of up to 7.7 cm/year offer a very good stratigraphic resolution, making it possible to study contamination
patterns on annual or even seasonal time scales. On the other hand, oxbow lakes may represent long-term contamination stores,
which are unlikely to be redistributed by river erosion and, hence, may possess significant environmental risks for the farther
future. 相似文献
Background, Aim and Scope In urban areas, soils are often dramatically altered by anthropogenic activity and these modifications distinguish these soils
(Anthrosols, Technosols) from those in natural systems. In urban environments, they receive considerable pollution from industry,
traffic and refuse. Since contaminated soil particles can be easily inhaled or ingested, there is a potential transfer of
toxic pollutants to humans. Risk assessment is essentially based on the determination of the total or mobile contents of pollutants
in soils using chemical extractions. This approach could be improved by taking into consideration the bioavailable fractions
of these toxic elements as measured by biotests. The coarse soil fraction usually neglected in analyses can nevertheless have
an effect on the concentration of metals in the soil solution. This coarse fraction is made up of the natural materials and
of technic materials constituting anthropogenic soils (plastic, paper, fabric, wood, bones, metallic elements and building
materials). These materials have variable capacities to release or adsorb trace elements. Samples representative of different
technic fraction components of Marrakech urban soils permit one to quantify their contribution to the enrichment of the soluble
metal concentrations. Works are carried out to achieve partial extractions of metals from the three fractions (less than 2
mm, coarse natural and coarse technic) of selected urban soils in order to determine their contribution to the metal contamination
of soils.
Materials and Methods Selected soils were collected from 9 sites according to a gradient of increasing anthropogenic influence from suburban to
urban zones. Soils were air-dried, homogenized, and sieved (2 mm). The coarse fraction was sorted to separate the different
technic materials and natural materials. Water extractions were run, on the natural, coarse fraction, on the complete technic
fraction of the 9 soils and on average samples made of technic materials sorted out of 58 topsoils sampled from different
sites in the city of Marrakech.
Results Results show that the percentage of the technic fraction increases while approaching the historic city center. It represented
about 14% in the most anthropogenically disturbed soils. Along this gradient, soils changed progressively from Anthrosols
to Technosols according to the WRB classification of urban and industrial soils. Analyses of metal contents showed that the
fine fraction (<2 mm) mainly contributed to the metallic contamination of the water soluble fraction. The natural coarse fraction
had the highest contribution to the copper release and was responsible for the release of all water-extractable copper in
some soils. Concerning the technic fraction, it has a significant contribution essentially in the most anthropogenically disturbed
soils as characterized by an elevated percentage of anthropogenic elements. The water extractable metal contents of average
samples of these anthropogenic elements shows that elevated metal concentrations were released by bones, wood, plastic and
fabric/paper.
Discussion This study concerns soils in urban areas, which are strongly impacted by human activities. Part of the soils can be classified
as Anthrosols, profoundly impacted through the addition of organic materials from household wastes, irrigation, or cultivation.
Other soils strongly impacted by human activities are Technosols dominated or strongly influenced by man-made materials. Technosols
appear mostly in urban and industrial areas and are more likely to be contaminated than Anthrosols. The composition and heterogeneity
of urban soils lead to modifications of the mobility and availability of pollutants depending on successive land-uses and
on the composition of technic materials. The fine fraction offers a high transferring surface capacity, leading to a high
mobilization of metals. The technic fraction contributes significantly to the metal release in the Technosols. This property
can be explained by a reversible adsorption of metals on the organic matter.
Conclusions Results confirm that anthropogenic activity causes a wide spatial diversity of soil quality in the urban and suburban area.
It introduces large amounts of technic materials in soils that could have an impact on the metal availability. It therefore
acts on the metal bioavailability in the urban Technosols.
Recommendations and Perspectives These results show that it is necessary, in addition to the characterization of the fine particles, to take into account the
contribution of the coarse fraction of the Technosols in the evaluation of risks of transfer of metals to the food chain. 相似文献
Background, aims, and scope Sediments and soils in coastal areas are frequently polluted by anthropogenic contaminants as the result of both riverine
or terrestrial discharge and autochthonic marine emissions. In order to determine petrogenic contamination in the coastal
industrial area of Kavala City in northern Greece, a combination of polycyclic aromatic hydrocarbon (PAH) and organic geochemical
petroleum biomarker analyses has been performed on marine and freshwater sediments as well as soils.
Materials and methods Soils, freshwater, and marine sediments have been treated by standard extraction methods. The dried and desulphurized sample
extracts have been fractionated by column chromatography, followed by addition of surrogate standards. Qualitative and quantitative
data were obtained by gas chromatograph connected with a flame ionization and electron capture detector (GC-FID/ECD) and by
GC linked to a mass spectrometer (GC/MS), whereas identification of compounds was based on EI+-mass spectra and gas chromatographic retention times. Quantitative data were obtained by integration of specific ion chromatograms.
Results The total PAH concentrations measured in the area varied highly, showing different levels from 18 up to 318,000 ng g−1 dry weight (dw). Several PAH ratios, as well as the ratio of pristane (Pr) to phytane (Phyt), have been considered. Out of
39 samples, 22 revealed a specific distribution of hopane fingerprints indicating petrogenic input. Finally, in numerous samples,
the ratio of 17α(H)-22,29,30-trisnorhopane (Tm) and 18α(H)-22,29,30-trisnorhopane (Ts) was calculated, as well as the ratio
of 22S-17α(H),21β(H)-30 homohopane (αβC31-hopane 22S) and 22R-17α(H),21β(H)-30 homohopane (αβC31-hopane 22R).
Discussion Based on the specific PAH ratios, a group of samples was clearly characterized to be contaminated dominantly by combustion-derived
emissions, whereas a second group of samples exhibited mixed influence from petrogenic and pyrogenic PAHs. On the other hand,
the exhibition of specific hopane fingerprints in many samples indicates a direct petrogenic input. Finally, the values of
the ratio of Tm/(Ts + Tm) and of αβC31-hopanes 22S/(22S+22R)-isomer demonstrated an input of highly mature organic matter that has to be clearly attributed to petroleum-derived
contamination, while the ratio of Pr/Phyt showed that most samples exhibited an input of organic matter.
Conclusions The coastal area of Kavala is strongly affected by anthropogenic contaminants. Petrogenic emissions were pointed out firstly
by PAH analyses that separated dominantly pyrogenic contaminated sites from areas affected by both pyrogenic and petrogenic
emissions. However, analyses of organic geochemical biomarkers revealed a much higher sensitivity in identifying petroleum-derived
contaminations and were successfully used to differentiate several petrogenic contaminations in the marine and terrestrial
samples.
Recommendations and perspectives Based on this study, it was recommended to use a complementary approach of source-specific substances to successfully characterize
petrogenic emissions. Generally, a PAH-based source identification of petrogenic versus pyrogenic contaminations should be
combined with petroleum biomarker analysis. PAH and biomarker ratios as well as individual biomarker fingerprints revealed
a more comprehensive view on the quality and quantity of petrogenic emissions in sediments and soils. 相似文献