فهرست مطالب s. ziaeinejad

The increasing use of consumer products containing nanomaterials (NMs) or utilizing nanotechnology has raised concerns about potential environmental risks associated with NMs. The toxicity of silver nanoparticles (AgNPs) in saltwater microcrustaceans, specifically Artemia franciscana, was investigated in this study. This study focused on the key factors of AgNPs concentration and exposure time. To evaluate toxicity, instar I Artemia nauplii were exposed to various concentrations of AgNPs (ranging from 0 to 10 mg/L) following the ISO/TS 20787 guideline. Immobilization rates were recorded at 12, 24, and 48 h post-exposure, and the Probit test was used for the statistical analysis. The results indicated significant toxicity to Artemia with an EC50 value of 4.18 mg/L after 48 hours. Significant relationships were found between immobility and the variables (exposure time and AgNPs concentration) through the use of multiple regression analysis for immobilization. The model explained a high percentage of immobilization variation (R-squared value: 97.74%). The study emphasizes the importance of 'exposure time' and 'concentration' in determining toxicity. The interaction effect between the parameters (concentration and exposure time) was significant. AgNPs concentration had a greater impact on increasing Artemia immobility compared to the exposure time. However, whether the same ranking applies to chronic toxicity or other organisms besides Artemia is uncertain. Understanding the relationship between exposure to NPs and their toxicity is crucial for the safe development of nanotechnology. Future research should address these questions to provide further insights and enable environmentally responsible risk assessments of AgNPs.

The effect of different concentrations of Ocimum basilicum extract supplement on growth and survival of Western white leg shrimp (Litopenaeus vannamei), juveniles was investigated. Shrimps were separated into four experimental groups of 0 (Controls), 60, 120 and 240 ppm extracts of O. basilicum. The photoperiod was regulated to a 12:12 dark/light cycle and molts, feces and dead shrimps were daily removed and 30% of water in each tank was exchanged by new sea water. Biometry was done once a week. Extract supplemented diet did not have any significant effect on weight gain (%), final weight (g), growth performance, feed utilization and body composition of L. vannamei when compared to shrimp in the control diet. It was also observed that the shrimp fed the diet containing 120 ppm O. basilicum extract obtained the highest weight gain (%) 6.23 ± 0.12% and the lowest rate (5.7 ± 0.1%) was for 240 ppm extract. In conclusion, dietary O. basilicum extract supplementation had no significant effects on the growth performance, survival rate, feed utilization and carcass composition of Western white leg shrimp juveniles. The positive results obtained encourage conducting further research on the administration of O. basilicum extract on Western white leg shrimp or other economically important species but with longer duration of culture period.

The aim of this study was to evaluate the effects of feed supplemented with different levels of Selenium Nanoparticles (SeN) on growth, survival, and biochemical indices of Acanthopagrus latus. Yellow-tail seabream fish with a mean weight of 52±3 gwasfed with four experimental diets containing 0, 0.5, 1, and 2 mg kg-1 SeN for 8 weeks. At the end of the experiment, the fish fed 0.5 mg kg-1 SeN showed a significant improvement of weight gain compared to the control (P< 0.05). Specific growth rate, feed conversion ratio, and survival were not significantly different between treatments (P> 0.05). The lowest activity of alkaline phosphatase, alanine amino transferase, creatinine phosphokinase and cholesterol were observed in 0.5 mg kg-1 SeN treatment, which was significantly lower than the control (P< 0.05). Although aspartate amino transferase, lactate dehydrogenase, triglyceride and creatinine were not significantly different among experimental treatments (P> 0.05), total protein and albumin levels were significantly increased in the 1 and 2 mg kg-1 SeN treatments compared to the control group. The highest level of globulin was observed in the 2 mg kg-1 SeN treatment. According to the results, the addition of 0.5 mg kg-1 SeN to fish feed could improve growth and biochemical parameters.

This study was carried out to investigate the effects of enriched Artemia with selenium nanoparticles on growth and survival rates and biochemical factors in guppy Poecilia reticulata larvae over a six-week period. Guppy larvae with a mean weight of 33.55 mg in three treatments and one control group (each with three replicates) were fed with Artemia franciscana enriched with 5, 10, and 50 mg L-1 selenium nanoparticles. In terms of growth indices, significant differences were observed among treatments in length increment, weight gain, specific growth rate and survival rate (p<0.05). There was no significant difference in condition factor (p>0.05). Regarding biochemical factors, significant differences were observed between treatments. Artemia - fed treatments enriched with 5 and 10 mg of selenium nanoparticles (treatment 1 and 2) showed the lowest and in the treatment fed with Artemia - enriched 50 mg nanoparticles (treatment 3) showed the highest levels of aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, creatinine phosphokinase and lactate dehydrogenase. The highest total protein content was observed in treatment 2, which was significantly different from the other treatments (p<0.05). Overall, if the goal of using selenium-enriched Artemia in fish larval diet is to increase survival and growth rate and improve biochemical indices, the use of selenium nanoparticles at the levels of 5 and 10 mg L-1 is appropriate for enriching Artemia to feed the fish larvae.