Toxicokinetic behavior, recovery and metabolism of napropamide (a pre-emergent herbicide) and its effect on Cytochrome P(450) of liver microsomal pellet were studied following a single high-dose oral administration of 2.5 g kg(-1) and continuous (7 days) oral administration of 500 mg kg(-1) in black Bengal goat. Napropamide was detected in blood at 15 min and the maximum quantity was recovered at 3 h after administration. The absorption rate constant (Ka) value was low indicating poor absorption from the gastrointestinal tract. High elimination half-life (t(1/2) beta) and low body clearance (Cl(B)) values coupled with higher transfer of compound from tissue to central compartment (K(21)) suggest that napropamide persisted in the blood for a long time, i.e., after 72 h of oral administration. The recovery percentage of napropamide, including metabolites, from goats varied from 75.94 to 80.08 and excretion of the parent compound through feces varied from 18.86 to 21.59%, indicating that a major portion of the orally administered napropamide was absorbed from the gastrointestinal tract of goat. Napropamide significantly increased the Cytochrome P(450) content of liver microsomal pellet. The recovery of metabolites from feces, urine, and tissues ranged from 4.2--6.2, 40.81--49.42, and 2.7--11.6%, respectively, during a 4--7 day period. The material balance of napropamide (including metabolites) following a single high-dose oral administration at 2.5 g kg(-1) during 4--7 days after dosing was found to be in the range of 75--80%. 相似文献
The dynamics of soil quality indicators, such as microbial biomass-C, soil respiration, and urease and acid phosphatase activities, in a laterite soil (Typic Haplustalf ) amended with different doses of Calcutta municipal solid waste compost (MSWC) were studied over 120 days of incubation at 30 °C under 60 % soil water holding capacity. The parameters were found to increase with the increase in doses of MSWC. Soil microbial biomass-C (MBC) and soil respiration activity reached peak values at 30 days of incubation and then gradually decreased up to 120 days of incubation. Urease and acid phosphatase activities showed peak values at 60 and 90 days of incubation, respectively. The increase in soil enzyme activities with the fall in MBC suggested that the release of enzymes was associated with lysis of microbial cells at the end of their life cycle. There was no indication of any detrimental effect on soil quality indicators of application of MSWC to soil. 相似文献
1.?The effects of injecting threonine in ovo on early growth, some immunological responses and the activity of digestive enzymes of broiler chicks were investigated. Fertile eggs were distributed into 6 groups, each of 60. These were: untreated control, sham control, 10, 20, 30 or 40 mg threonine. Threonine was dissolved in 0·5 ml sterile saline and inoculated into the yolk sac of the 14-d-old embryo through the narrow end of the egg.
2.?The ratio of chick to egg weight was 1·6% higher in the group given 30 mg threonine and at 28 d of age chicks receiving threonine were 29 to 79 g heavier than untreated controls.
3.?Food conversion ratio until 7 d after hatching was improved in those chicks receiving 10, 20 or 40 mg threonine but there was no significant effect on the activities of amylase, pepsin or trypsin.
4.?The humoral response to sheep red blood cells was significantly greater in those groups receiving 10, 20 or 30 mg threonine supplementation than in untreated controls.
5.?The response to phytohaemagglutinin-P, a measure of the cell-mediated immune response, was not affected, however.
6.?It is concluded that injections of 20 to 30 mg threonine into yolk sac can improve post-hatching growth and humoral responses of broiler chicks. 相似文献
This study examined the effect of deltamethrin on some of the neuropharmacological paradigms in a rat brain such as the motor co-ordination test using a rotarod, the pentobarbitone-induced sleeping time and pentylenetetrazole (PTZ)-induced convulsion as well as the gamma aminobutyric acid (GABA) level. Albino Wistar rats were used as the experimental animals. Different neuropharmacological paradigms such as the motor co-ordination by the rotarod, pentobarbitone-induced sleeping time and the PTZ-induced convulsion were examined after administering deltamethrin orally at two doses, 150 mg/kg (LD50) and 15 mg/kg (1/10 LD50). The GABA level in the rat brain was estimated by HPLC after a single oral dose of 150mg/kg deltamethrin. Deltamethrin significantly reduced the motor coordination, decreased the onset time and increased the sleeping time duration induced by pentobarbitone. In addition, it also decreased the onset time and increased the duration of convulsions induced by PTZ at 150 mg/kg (LD50) and 15 mg/kg (1/10 LD50), respectively. Further deltamethrin administration decreased the GABA levels in the cerebellum as well as in the whole brain (except the cerebellum) significantly at the LD50 dose level. There was some correlation between the effect of deltamethrin on the central GABA levels and its neuropharmacological effects. 相似文献
The mulberry leaves have been considered as a sole food source for silkworm, Bombyx mori (L.). In present work an attempt was made to investigate the role of low molecular weight peptide(s) isolated from mulberry leaves on silkworm rearing. Also we have tried to find out the role of free-radical scavenging activities of isolated peptide(s) on silkworm growth. Larval growth rate was found effective under the influence of peptide(s). Consumption rate of larvae after peptide(s) treatment on mulberry leaves was significantly enhanced over control. High antioxidant activity was found in Low molecular weight peptide(s) which have an effect on silkworm. 相似文献
Coal is one of the major sources of fuel for electricity production and will continue to be used for many more decades. Thus, it is important to study the effects of disposal of coal burning byproducts including fly ash into the environment. In this study, the solubility of cations and anions from the fly ash in water is discussed. Also, the fractionation of different metals from fly ash in water is studied to understand which fraction of the metals would likely be mobilized. The results from these studies suggested that the metals in the fly ash are bound mostly to carbonate, organic, and residual fractions. Also, when water solubility data are modeled with a geochemical model (Visual MINTEQ), the saturation index predictions suggested that brucite (Mg(OH)2) and calcite (CaCO3) could potentially precipitate and mineralize the atmospheric CO2. Such mineralization process could potentially reduce the leaching of toxic metals from fly ash. Results from this study will be helpful in understanding the fate of different metals from fly ash land disposal environments. 相似文献
In the present study, conducting nanofillers are incorporated in thermoplastic polyurethane (TPU) to produce nanocomposite fibers through melt compounding route using micro twin screw extruder attached to a fiber drawing device. Nanocomposite fibers using bulk graphite, nanographite and carbon nanofiber were produced using varying amounts of these nanofillers. Metal coated nanographite, new hybrid nanoparticle produced in house, were also used to impart conductivity to the TPU fiber. The process parameters such as processing temperature, mixing time and rpm of the screw have been optimized considering minimum change in TPU bulk properties. It has been found that the nanofillers can be melt mixed safely up to 4 min with the TPU at 180 °C and 100 screw rpm. These mixing conditions give reasonable amount of dispersion. The studies on such fibers in differential scanning calorimetry (DSC) and thermomechanical analyzer (TMA) reveals that the metal coated nanographite particles make the nanocomposite fibers more thermally stable. Both the D. C. conductivity and A. C. impedance of the nanocomposite fibers have reduced significantly even at very low loading of nanofillers, although the conductivity of the produced fibers are in antistatic range (D.C. conductivity ~10?4 S/m). 相似文献
Carbon sequestration strategies highlight tree plantations without considering their full environmental consequences. We combined field research, synthesis of more than 600 observations, and climate and economic modeling to document substantial losses in stream flow, and increased soil salinization and acidification, with afforestation. Plantations decreased stream flow by 227 millimeters per year globally (52%), with 13% of streams drying completely for at least 1 year. Regional modeling of U.S. plantation scenarios suggests that climate feedbacks are unlikely to offset such water losses and could exacerbate them. Plantations can help control groundwater recharge and upwelling but reduce stream flow and salinize and acidify some soils. 相似文献
MicroRNAs (miRNAs) are approximately 21-nucleotide-long RNA molecules regulating gene expression in multicellular eukaryotes. In metazoa, miRNAs act by imperfectly base-pairing with the 3' untranslated region of target messenger RNAs (mRNAs) and repressing protein accumulation by an unknown mechanism. We demonstrate that endogenous let-7 microribonucleoproteins (miRNPs) or the tethering of Argonaute (Ago) proteins to reporter mRNAs in human cells inhibit translation initiation. M(7)G-cap-independent translation is not subject to repression, suggesting that miRNPs interfere with recognition of the cap. Repressed mRNAs, Ago proteins, and miRNAs were all found to accumulate in processing bodies. We propose that localization of mRNAs to these structures is a consequence of translational repression. 相似文献