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21.
The extent of the risk of (Z)- and (E)-1,3-dichloropropene and their transformation products (Z)- and (E)-3-chloroallyl alcohol causing a hazard to the quality of groundwater pumped up for public water supply from below flower-bulb fields has been evaluated. The 1,3-dichloropropenes were incubated at 10°C in water-saturated subsoil material from three such fields. A first stage with gradual transformation was followed by a second stage with comparatively rapid transformation and after three months negligible amounts remained. The 3-chloroallyl alcohols were incubated at 15°C in soils from the root zone of the same fields. Complete transformation had occurred in about a week or even less. The 3-chloroallyl alcohols were also incubated in the water-saturated subsoil material at 10°C. Again, a first stage with gradual transformation was followed by a second stage with fast transformation. In most instances, the concentrations had fallen to a very low level within three months. It was concluded that it is unlikely that residues in the upper groundwater would permeate into the deeper groundwater pumped up for public water supply.  相似文献   
22.
The PA28 activator γ‐subunit encoded by the PSME3 gene is the third component of the PA28 activator complex, which is the 11S regulator of the 20S proteasome. The open reading frame (ORF) sequence of the porcine PSME3 gene encoding the proteasome activator γ‐subunits (or proteasome activator subunit 3) was determined. The deduced amino acid sequence shows 100% identity with the corresponding human and murine sequence. Two single nucleotide substitutions, one located in intron 5 (I5), the other one in exon 8 (E8), were detected using polymerase chain reaction–restriction fragment‐length polymorphism (PCR–RFLP). Analysis on allele frequencies of the two polymorphic sites determined in different pig breeds (Duroc, Tibet, Qingping, Meishan, Erhualian and Mingzhu) showed large differences between Duroc and Chinese indigenous pig breeds investigated. The PSME3 gene was physically assigned to SSC12p11 – (2/3) p13 in the vicinity of the GH gene. This result provides an additional type I marker to the GH linkage group on SSC12.  相似文献   
23.
A model for the transport of pesticides in non-structured arable soil has been tested under field conditions. Three classes of sorption site are distinguished in the model. Sorption at class 1 sites is assumed to be at equilibrium whereas sorption at class 2 and class 3 sites is calculated using rate equations. Class 2 sites equilibrate on a time scale of days and class 3 sites equilibrate on a time scale of hundreds of days. In the model, the liquid phase is assumed to be homogeneous and completely mobile. The model was validated in two field experiments on a loamy sand soil using the herbicides cyanazine and metribuzin and using bromide ion as a tracer of liquid flow in soil. Ignoring sorption at class 3 sites resulted in large discrepancies between calculated and measured concentration profiles. Calculated concentration profiles were sensitive to the desorption rate constant for class 3 sites.  相似文献   
24.
Dubey JP  Pas A 《Veterinary parasitology》2008,153(1-2):147-151
Fatal toxoplasmosis was diagnosed in a Blanford's fox (Vulpes cana) from the United Arab Emirates. Toxoplasma gondii-like tachyzoites were found associated with necrosis in intestine, spleen, liver, kidneys, lungs, skeletal muscle, brain and heart. Protozoal tachyzoites reacted positively with T. gondii-specific polyclonal antibodies. Antibodies to T. gondii were detected in 10 of 12 V. cana assayed by the latex agglutination or the modified direct agglutination test.  相似文献   
25.
Background: Cardiorespiratory syndrome of common foxes is associated with a mortality rate ranging from 2.1% to 20%.

Objective: The aim of this study was to analyze the prevalence of cardiac abnormalities in common foxes (Vulpes vulpes) from Polish farms with a history of cardiorespiratory syndrome.

Animals and methods: The prevalence of cardiac abnormalities in common foxes from a Polish farm with a history of cardiorespiratory syndrome was assessed as well as morphological examination of 60 heart specimens from clinically healthy animals. In addition, 38 foxes were examined echocardiographically and subjected to postmortem examination.

Results: Atrioventricular valvular abnormalities were found in 57 out of the 98 (58%) analyzed hearts. The abnormalities of the mitral valve documented in more than 20% of the foxes in involved tendinous chords (completely lacking or shortened), papillary muscles and mitral cusps associated with both insufficiency and stenosis of the left atrioventricular orifice. Abnormalities of the tricuspid valve included significant shortening of the tendinous chords and thickening of the valve cusps with the impairment of their mobility. The results of the echocardiographic and postmortem examination were consistent in 79% of the cases. The specimens collected from animals with and without atrioventricular valvular anomalies did not differ significantly in terms of cardiomyocyte width, number of inflammatory cells, adipose tissue content and presence of polychromatic cardiomyocytes.

Conclusion: Congenital atrioventricular valvular defects may be involved in the etiology of cardiorespiratory syndrome in common foxes, and echocardiography can be used as a measure of stock's health and a criterion for selection for mating.  相似文献   

26.
When pesticides leach through the soil to the upper groundwater zone, it is important to know whether further transformation occurs before the pumping wells for drinking water are reached. Atrazine and bentazone were incubated (at 10°C) in five water-saturated sandy subsoils (collected at depths between 1·5 and 3·5 m), simulating the conditions in the field. In three subsoils with comparatively low pH and intermediate to high redox potential, atrazine was transformed gradually, to leave 1·9%, 6·2% and 17·5% of the dose after about five years. In one of these subsoils, hydroxy-atrazine was detected; the amount corresponded to half of the dose of atrazine. In one anaerobic subsoil with high pH, the transformation of atrazine was comparatively fast (half-life about 0·15 year). Another anaerobic subsoil, with similar pH and a somewhat higher redox potential, however, showed hardly any transformation. Sterilization of the first anaerobic subsoil had no effect on the rate of transformation. In the course of about five years, bentazone in the first three subsoils was transformed gradually to leave <0·25%, 11% and 25% of the dose. Bentazone transformation in the two subsoils with high pH and low redox potential was very slow, but the presence of oxygen in one of these subsoils speeded up the transformation. © 1998 SCI  相似文献   
27.
The Pesticide Transport Assessment model (PESTRAS) is a process-oriented model to simulate the fate and movement of water and pesticides in a cropped field soil. The model was evaluated using field data for bromide, ethoprophos and bentazone, collected from a field experiment in a humic sandy soil near Vredepeel, the Netherlands. Model predictions were generally within the 95% confidence intervals of the observations when site-specific model inputs were used. If generic parameter values were used, the model predictions sometimes deviated strongly from the observed data. This was especially true for pesticide degradation properties. The bromide simulations showed that preferential flow was not an important process for this field soil. A significant fraction of the applied ethoprophos disappeared by surface volatilization. The downward movement of this pesticide was slightly overestimated, due to not considering sorption kinetics. The depth-dependence of pesticide transformation was atypical: an important fraction of the applied bentazone was transformed under micro-aerobic to anaerobic conditions in the subsoil. © 1998 SCI  相似文献   
28.
29.
1. This experiment aimed to determine if the pharmacokinetics of amoxicillin (AMO) was affected by rapid growth or intravenous (i.v.) injection of Escherichia coli lipopolysaccharide (LPS).

2. Turkeys of 2.0, 5.5 and 12.0 kg were administered i.v. or orally with AMO sodium at the dose of 15 mg/kg. Another group (5.7 kg) was treated with LPS prior to i.v. AMO administration. Plasma drug concentrations were determined using high-performance liquid chromatography and pharmacokinetic parameters were calculated using a non-compartmental model. To assess the haemodynamic effects of endotoxaemia, turkeys were subjected to echocardiography.

3. During growth from 2.0 to 5.5 kg, the area under the drug concentration-time curve after i.v. AMO administration increased from 9.37 ± 2.43 to 21.29 ± 5.49 mg×h/ml. Total body clearance decreased from 1.72 ± 0.55 to 0.75 ± 0.12 l/h/kg. Growth to 12.0 kg did not further affect these parameters. Mean residence time and elimination half-life gradually increased. Pharmacokinetics of orally administered drug followed a similar pattern. LPS injection affected stroke volume, heart rate and resistance index. However, it did not affect the pharmacokinetic profile of AMO in survivors.

4. It is concluded that rapid growth in turkeys affects AMO pharmacokinetics. Endotoxaemia, on the other hand, does not affect AMO elimination if compensatory mechanisms develop.  相似文献   

30.
1. The aim of this study was to determine if the pharmacokinetics (PK) of florfenicol (FF) undergo age-dependent changes in broilers. Since drug elimination depends on cardiovascular functions, a haemodynamic study was performed in parallel.

2. Broilers of 0.68, 1.27, 2.45 and 5.13 kg were administered FF in a single intravenous dose of 30 mg/kg body weight. Plasma drug concentrations were determined using high-performance liquid chromatography and PK parameters were calculated using a non-compartmental model. Echocardiography was used to measure haemodynamic functions.

3. During growth, the area under the drug concentration-time curve (AUCinf) increased from 25.7 ± 2.9 to 39.0 ± 8.0 mg h/l. Total body clearance (ClB) gradually decreased from 1.19 ± 0.14 to 0.80 ± 0.15 l/h/kg. Elimination half-life increased from 0.73 ± 0.08 to 1.07 ± 0.07 h, whereas volume of distribution (Vss) remained unchanged. Haemodynamic measurements revealed an increase in cardiac output, from 495 ± 65 to 1303 ± 306 ml/min, in the respective body weight groups.

4. Allometric models for PK and haemodynamic parameters were developed and validated. All models proved to be statistically significant; however, only models for ClB and Vss met stringent validation criteria. Model for ClB was used to calculate an optimal dose for a given age group that provides uniform AUCinf.

5. Age-dependent change in FF kinetics may cause variability in therapeutic response under clinical conditions. A novel approach to the dosing protocol was proposed as a means of optimising therapeutic efficacy.  相似文献   

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