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The combustion of fossil fuels containing sulfur results in the release of sulfur dioxide into the atmosphere and environmental pollution. Hence, the researchers focused on the biological desulfurization method. Dibenzothiophene is used as the model molecule to study the ability of the desulfurization of microorganisms. The most suitable sources of carbon, nitrogen and sulfur concentration optimized by response surface method to obtain the highest cell growth and biological desulfurization activity. The performance of iron nanoparticles on the growth and biodesulfurization activity of thermophilic bacterium Bacillus thermoamylovorans strain EAMYO was investigated. Characterization of starch-modified iron nanoparticles was performed by TEM, SEM. The images of TEM and SEM of starch / Iron nanoparticles showed that the Fe₃O₄ and Fe0 nanoparticles were 20 and 30 nm, respectively. The investigating the growth of microorganism in the presence of iron nanoparticles showed that these nanoparticles not only did not have a toxic effect on microorganism growth, but also increased the growth of microorganism in 96 h (OD 660 = 1.864, 1.896 respectively in the presence of nanoparticles Fe₀ and Fe₃O₄), while the highest rate of growth in the absence of nanoparticles in 96 h (OD660 = 1.51). Also, the activity of desulfurization in the presence of starch/Fe₀ nanoparticles and starch/Fe₃O₄ / starch increased by 26.52% and 10.75%, respectively, compared to the cells without the coating of iron nanoparticles.
 

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The accumulation of nanoparticles in the environment and aquatic ecosystems due to their wide application in industries, agriculture, medicine and pharmaceuticals has caused an increasing concern about the environment and increasing exposure to nanoparticles in ecosystems and humans. Iron oxide nanoparticles easily enter the bloodstream, accumulate in different tissues and cause damage to these tissues. Therefore, in this research, changes in the intestinal tissue of gray mullet fish (M. cephalus) and tissue accumulation in oral exposure to iron oxide nanoparticles were investigated.
110 pieces of young gray mullet after 2 weeks of adaptation were treated in four-time groups of 1, 7, 14 and 28 days, and one group was considered as a control. The mullet fish received iron oxide nanoparticles twice a day at the rate of 15 mg/kg attached to the food. The results showed that although the amount of tissue iron increased significantly only in the 28-day group, the consumption of iron oxide nanoparticles in almost all groups increases the tissue accumulation of iron in the intestine. The intestinal histological study showed changes such as the increase in the number and size of goblet cells, destruction of microvilli structure, bleeding and degrees of necrosis, and the intensity and extent of the changes in the intestinal tissue increased with increasing exposure time.
These observations showed that the consumption of iron oxide nanoparticles has a negative effect on intestinal function and causes iron accumulation and the occurrence of time-dependent injuries.

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Introduction: In this study, we investigated the accumulation and tissue effects due to injection of biological magnetic iron nanoparticles in the ovarian tissue of Wistar rats in response to electromagnetic field by inductively coupled plasma (ICP) and histopathological methods.
Methods: In this experimental study, the animals were classified in groups of four as follows: Group of healthy female rats receiving nanoparticles with non-toxic dose in absence of  electromagnetic field, group of healthy female rats without receiving nanoparticles and in absence of  electromagnetic field (control group), group of healthy female rats receiving nanoparticles with non-toxic dose in presence of an electromagnetic field and group of healthy female rats without receiving nanoparticles in presence of an electromagnetic field. After grouping the rats, the biological nanoparticles were injected intraperitoneally and an electromagnetic field was created on the skin of the rats at the site of the ovaries, which were fixed using tape. Then, by ICP analysis, we examine the presence of iron nanoparticles in the tissue.
Results: Magnetic iron nanoparticles had low toxicity so that its half-maximal inhibitory concentration (IC50) value in well number 1 was 0.386. In the two groups of non-toxic doses of nanoparticles in presence or in absence of electromagnetic field, No changes were observed for primary and secondary follicles, as well as connective tissue and blood.
Conclusion: Magnetic iron nanoparticles have no destructive effects on ovarian tissue and have low cell accumulation and therefore their use in this field was recommended to improve the future treatment of ovarian cancer.