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H. KHODAVERDILOO M. RAHMANIAN S. REZAPOUR S. GHORBANI DASHTAKI H. HADI F. X. HAN 《土壤圈》2012,22(3):304-313
Mobility and bioavailability of lead (Pb) could be affected considerably by soil physicochemical properties;however,less is known about the effect of Pb levels and aging time.This study was conducted to evaluate the effects of Pb levels and wetting-drying (WD) cycles on distribution and bioavailability of Pb in three semi-arid zone soils treated with different levels of Pb(NO 3) 2.Wetting-drying cycles simulated the actual field irrigation in the semi-arid soils.A soil with a long history of Pb contamination was also taken as a reference soil.The soils were spiked with various levels of Pb and incubated under WD cycles for 160 d.Sequential extractions and batch sorption experiments were performed to assess the fractionation of Pb in the spiked soils.Redistribution index (U ts) and reduced partitioning parameter (I R) were applied to semi-quantify the distribution of Pb in the spiked soils.A small amount of Pb sorbed was desorbed by the soils,indicating a strong and irreversible binding of Pb in the studied soils.Contribution of carbonate-bound (Car) and residual (Res) Pb fractions to the total Pb of the soils was more than 97%.The Car,soluble plus exchangeable (SE),and organic matter-bound (OMB) fractions of Pb were transferred to the Res fraction under the WD cycles.The I R and U ts values were influenced by Pb loading levels and WD;therefore,the Pb lability and/or redistribution pattern could semi-quantitatively be assessed via these parameters.At the end of the experiment,the I R and U ts values for the Pb salt-spiked soils did not show the quasi-equilibrium state.The lability of Pb in the soils decreased with increasing incubation time and showed a strong dependence on Pb levels and soil chemical composition.WD cycles significantly affected the overall lability of Pb in soils through influencing the redistribution of Pb among solid-phase components. 相似文献
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Pharmacokinetics of tobramycin in the camel 总被引：1，自引：0，他引：1
A. A. A/HADI I. A. WASFI† F. A. GADIR M H AMIRI† A. K. BASHIR† J. D. BAGGOT‡ 《Journal of veterinary pharmacology and therapeutics》1994,17(1):48-51
A/Hadi, A.A., Wasfi, I.A., Gadir, F.A., Amiri, M.H., Bashir, A.K. Baggot, J.D. Pharmacokinetics of tobramycin in the camel. J. vet. Pharmacol. Therap. 17 . 48–51.
The pharmacokinetics of tobramycin were determined in six healthy camels (Camelus dromedarius) following the intravenous (i.v.) and intramuscular (i.m. administration of single doses of tobramycin sulphate (40 mg/ml). The half-life to tobramycin was 189 ± 21 min and the mean residence time was 254 ± 26 min. The apparent volume of distribution (area method) was 245 ± 21 ml/kg. while volume of the central compartment of the two-compartment pharmaco-kinetic model was 110 ± 12 ml/kg. The clearance (systemic) of tobramycin was 0.90 ± 0.10 ml/min/kg. Values of the pharmacokinetic parameters suggest that glomerular filtration rate is lower in camels than in other ruminant species, horses, dogs and cats. Following i.m. administration of the dose (1.0 mg/kg), the drug was rapidly absorbed with peak serum concentration of 3.32 ± o.59 g/ml at 20–30 min; the absorption half-life was 3.9 ± 0.9 min. The systemic availability of tobramycin was 90.7 ± 14.4%. The apparent half-life was 201 ±40 min, which was not significantly longer than the half-life following i.v. administration of the drug. Based on the pharmacokinetic values obtained in this study, a dosing rate of 2.5 mg/kg administered by i.m. injection at 12-h intervals can be recommended. This dosage regimen should achieve an average steady state serum concentration of 4 g/ml with peak serum concentration approaching, but not exceeding, 10 g/ml. 相似文献
The pharmacokinetics of tobramycin were determined in six healthy camels (Camelus dromedarius) following the intravenous (i.v.) and intramuscular (i.m. administration of single doses of tobramycin sulphate (40 mg/ml). The half-life to tobramycin was 189 ± 21 min and the mean residence time was 254 ± 26 min. The apparent volume of distribution (area method) was 245 ± 21 ml/kg. while volume of the central compartment of the two-compartment pharmaco-kinetic model was 110 ± 12 ml/kg. The clearance (systemic) of tobramycin was 0.90 ± 0.10 ml/min/kg. Values of the pharmacokinetic parameters suggest that glomerular filtration rate is lower in camels than in other ruminant species, horses, dogs and cats. Following i.m. administration of the dose (1.0 mg/kg), the drug was rapidly absorbed with peak serum concentration of 3.32 ± o.59 g/ml at 20–30 min; the absorption half-life was 3.9 ± 0.9 min. The systemic availability of tobramycin was 90.7 ± 14.4%. The apparent half-life was 201 ±40 min, which was not significantly longer than the half-life following i.v. administration of the drug. Based on the pharmacokinetic values obtained in this study, a dosing rate of 2.5 mg/kg administered by i.m. injection at 12-h intervals can be recommended. This dosage regimen should achieve an average steady state serum concentration of 4 g/ml with peak serum concentration approaching, but not exceeding, 10 g/ml. 相似文献
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A greenhouse experiment was conducted to study the role of plant growth regulators, a chelating agent, and plant growth‐promoting bacteria in lead (Pb) phytoextraction and their subsequent effect on the weed plant, Parthenium hysterophorus. Gibberellic acid (GA3) and indole‐3‐acetic acid (IAA) were used as the foliar spray. Ethylenediamine tetra acetic acid (EDTA) was applied in split doses. Bacillus and Rhizobium strains were used as a single culture and as co‐cultures. The accumulation of Pb in different parts of the plant was analyzed by using an atomic absorption spectrophotometer. The amount of lead translocation and accumulation in the stems and leaves was significantly higher in the hormonal and EDTA treatments, while the microbial treatments showed no significant difference in the amount of Pb translocation into the stems and leaves, when compared to the control. The EDTA increased the amount of translocation into the shoots, but the dry biomass declined and subsequently reduced the total Pb phytoextraction. The GA3 treatment showed the maximum total Pb accumulation, along with a higher dry biomass. The microbial co‐inoculated plants showed a significant increase in their dry biomass but the Pb accumulation did not increase like with the GA3 and IAA treatments. These findings encourage the use of the GA3 application for Pb phytoextraction by P. hysterophorus. One important feature of this weed plant is its unpalatable nature to herbivores, which could help in reducing the entrance of Pb into the food chain. Gibberellic acid is environmentally friendly compared to EDTA; therefore, more investigation of GA3 and P. hysterophorus is required. 相似文献
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Abdul HADI Oslan JUMADI Kazuyuki INUBUSHI Kazuyuki YAGI 《Soil Science and Plant Nutrition》2008,54(4):644-649
Field experiments were designed to quantify N2 O emissions from corn fields after the application of different types of nitrogen fertilizers. Plots were established in South Kalimantan, Indonesia, and given either urea (200 kg ha−1 ), urea (170 kg ha−1 ) + dicyandiamide ([DCD] 20 kg ha−1 ) or controlled-release fertilizer LP-30 (214 kg ha−1 ) prior to the plantation of corn seeds (variety BISI 2). Each fertilizer treatment was equivalent to 90 kg N ha−1 . Plots without chemical N fertilizer were also prepared as a control. The field was designed to have three replicates for each treatment with a randomized block design. Nitrous oxide fluxes were measured at 4, 8, 12, 21, 31, 41, 51, 72 and 92 days after fertilizer application (DAFA). Total N2 O emission was the highest from the urea plots, followed by the LP-30 plots. The emissions from the urea + DCD plots did not differ from those from the control plots. The N2 O emission from the urea + DCD plots was approximately one thirtieth of that from the urea treatment. However, fertilizer type had no effect on grain yield. Thus, the use of urea + DCD is considered to be the best mitigation option among the tested fertilizer applications for N2 O emission from corn fields in Kalimantan, Indonesia. 相似文献
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Plant pests and diseases have significant negative impacts on global food security, world trade and rural livelihoods. Climate change exacerbates these impacts in certain parts of the world. Overreliance on pesticides as the primary tool for plant pest management leads to problems such as pesticide resistance and pest resurgence. Environmental and food safety concerns are also associated with overuse of pesticides in crop production. There is clearly a need for a shift in pest management strategies and practices globally. Optimization of structures and functions in crop production agroecosystems through soil conservation practices and cropping diversification can improve pest regulation services provided in the systems. Prioritization of safer alternatives and practices in the IPM pyramid, such as resistant varieties and biopesticides, helps minimize the use of potentially risky agricultural inputs such as synthetic pesticides. Investment is needed to boost the development of innovative green technologies and practices. Production, distribution, use and regulatory capacities need to be strengthened to facilitate large-scale adoption of green technologies and practices. Finally, policy, financial and market instruments should be wielded to provide an enabling environment for the transformation to sustainable plant pest and disease management strategies and practices worldwide. 相似文献
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