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The study elucidated the pharmacokinetics of streptomycin in healthy lactating she-buffaloes after a single intramuscular (IM) injection (10 mg/kg). The drug attained its peak concentrations of 24.39±2.67, 0.45±0.05 and 5.06±0.18 g/ml at 1, 4 and 1 hour in plasma, milk and uterine fluid respectively. Calculations based on the assumption of a 2-compartment model gave a plasma t1/2 () of 4.01±0.44 h and an apparent volume of distribution [Vd(area)] of 0.47±0.06 l/kg. The drug was detectable in the plasma, milk and uterine fluid for 30, 8 and 12 hours, respectively. A therapeutic concentration of the drug was maintained for 6 to 7 hours in the plasma and for around 1 hour only in the uterine fluid. However, a therapeutic level could not be achieved in milk at any time. The results suggest that the drug can be used clinically by the IM route against streptomycin susceptible systemic infections but not those in the uterus and mammary gland.  相似文献   
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Several randomly selected glasshouse grown somaclones of rose scented geranium, Pelargonium graveolens L’Her Ex Ait. cv. Hemanti were successfully transferred to the field in Northern India for evaluation. Two distinct morphotypes were described on the basis of leaf dentation-one resembling the parental cultivar in having highly dentated leaves (HDL) and the other with less dentated leaves (LDL). After repeated field-testing for 3 consecutive years, the HDL clones closely resembled the parental cultivar with respect to the different quantity and quality determining traits, while the LDL group was clearly different. The field established LDL somaclones possessed higher herb yield, number of branches and other oil yield attributing traits as compared to the HDL clones and the parent cultivar. The chemical investigations of the essential oil revealed significant differences between the LDL clones, the HDL clones and the control. Selection of such somaclones, which are superior to the parental in most of the quantitative and qualitative traits and show better adaptability to different areas of cultivation, will help towards commercialization of geranium in India.  相似文献   
66.
DNA glycosylases must interrogate millions of base pairs of undamaged DNA in order to locate and then excise one damaged nucleobase. The nature of this search process remains poorly understood. Here we report the use of disulfide cross-linking (DXL) technology to obtain structures of a bacterial DNA glycosylase, MutM, interrogating undamaged DNA. These structures, solved to 2.0 angstrom resolution, reveal the nature of the search process: The protein inserts a probe residue into the helical stack and severely buckles the target base pair, which remains intrahelical. MutM therefore actively interrogates the intact DNA helix while searching for damage.  相似文献   
67.
Conditions affecting Agrobacterium-mediated transformation of soybean [Glycine max (L.) Merr.], including seed vigor of explant source, selection system, and cocultivation conditions, were investigated. A negative correlation between seed sterilization duration and seed vigor, and a positive correlation between seed vigor and regenerability of explants were observed in the study, suggesting that use of high vigor seed and minimum seed sterilization duration can further improve transformation efficiency. Selection schemes using glufosinate or bialaphos as selective agents in vitro were assessed. Glufosinate selection enhanced soybean transformation as compared to bialaphos. The use of 6 mg L-1 glufosinate during shoot induction and shoot elongation stages yielded higher final transformation efficiency ranging from 2.0% to 6.3% while bialaphos at 4 to 6 mg L-1 gave 0% to 2.1% efficiency. Including cysteine and DTT during cocultivation increased the transformation efficiency from 0.2–0.9% to 0.6–2.9%. This treatment also improved T-DNA transfer as indicated by enhanced transient GUS expression. Shoot regeneration and Agrobacterium infection were attained in twelve soybean cultivars belonging to maturity groups I-VI. These cultivars maybe amenable to genetic transformation and may provide a valuable tool in soybean improvement programs. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   
68.
This study is aimed at ascertaining the chemical partitioning ofCu, Zn, Pb, Ni, Cr and Cd in sewage sludge and agricultural soils repeatedly amended with sludge. The operationally determined speciation was investigated by using selective five steps sequential extraction method for partitioning these metals into different chemicalforms, likely to be released in solution under various environmental conditions. It provides qualitative evidence regarding the form of the association of metals and indirectly of their bioavailability. It can help to explain the process by which metals are eliminated from sewagesludge and also indicate the impact of the use of sludge on agriculturalsoils, as amendments. Data obtained by extraction procedure showed different metal distribution trend among the fractions in sewage sludgeand sludge-amended soils. Comparison of distribution pattern of metals in sludge and sludge-applied soils shows that there is possible redistribution of metals among the different phases. The sum of the metal content in the fractions compared well with the total metal content in sewage sludge, the ratios averaging 1.02, 1.04, 1.07, 0.94, 1.06, and 1.12 for Cu, Zn, Pb, Ni, Cr, and Cd, respectively. The metal recovery efficiency in sludge-amended soils was found to be: 108±6%, 102±5%, 115±8%, 111±4%, 104±7%and 124±28% for Cu, Zn, Pb, Ni, Cr and Cd, respectively.  相似文献   
69.
Summary A field experiment was carried out to investigate the effects of three pesticides (a herbicide, Basalin, and two fungicides, Dithane M-45 and Bengard), separately or in combination, on jute rhizosphere microflora (total bacteria, ammonifying bacteria, aerobic non-symbiotic N2-fixing bacteria, thiosulphate-oxidising bacteria, actinomycetes, and fungi), N mineralisation, and thiosulphate oxidation in soil. The pesticide treatments had significantly different effects on the rhizosphere microflora and their activities, depending on the kind of pesticide, the mode of application (individually or in combination), and the stage of growth of the jute plants. Although the pesticides hindered growth in the early stages, later stages were not affected because the effects on the rhizosphere microflora subsided. In addition, the combination of the herbicide Basalin (a dinitroaniline compound) and the fungicide Bengard (a benzimidazole derivative) virtually cancelled out each other's effects.  相似文献   
70.
The ability of phosphate-solubilizing rhizobacteria to enhance the growth and phosphorus uptake of canola (Brassica napus L., cv. Legend) was studied in potted soil experiments in the growth chamber. One hundred and eleven bacteria isolated from the rhizosphere of field-grown plants, and a collection of nine bacteria known to be effective plant growth-promoting rhizobacteria (PGPR), were screened for P-solubilization in vitro. All rhizobacteria were identified using whole-cell fatty acids methyl ester (FAME) profiles. The best P-solubilizing isolates were two Bacillus brevis strains, B. megaterium, B. polymyxa, B. sphaericus, B. thuringiensis, and Xanthomonas maltophilia (PGPR strain R85). The P-solubilizers were tested for their effects on growth and P-uptake of canola plants in a P-deficient soil amended with rock phosphate. Although some of the P-solubilizing rhizobacteria significantly increased plant height or pod yield, none increased P-uptake. The most effective inoculant was a B. thuringiensis isolate which significantly increased the number and weight of pods and seed yield without rock phosphate. Xanthomonas maltophilia increased plant height, whereas the other bacilli increased the number on weight of pods. These results demonstrate the potential use of these P-solubilizing rhizobacteria as inoculants for canola, but indicate that P-solubilization was not the main mechanism responsible for positive growth response. Received: 8 February 1996  相似文献   
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