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Presence of bacteria in aqueous solution influences virus adsorption on nanoparticles
2013
Zhao, Bingzi | Zhang, Jiabao | Jiang, Yan
Virus contamination in wastewater is usually accompanied by the existence of various bacteria. Nanoparticles (NPs) have been shown to efficiently remove virus. In this study, bacterial cells, supernatants, and cultures were harvested separately from three strains at the culture ages of 6 and 24 h, corresponding to the log and stationary phases, respectively. The aim is to investigate how their presence affects virus adsorption on the three Fe and Al oxide NPs (α-Fe2O3, γ-Fe2O3-B, and Al2O3) and how these effects change with bacterial growth phase. Bacteriophage phiX174 was used as a virus model. Results showed that bacterial cells, supernatants, and cultures harvested at 6 h generally reduced virus adsorption by an average of 0.75 ± 0.84, 7.7 ± 9.0, and 10.3 ± 8.6 %, respectively, while those harvested at 24 h reduced virus adsorption by an average of 2.1 ± 0.93, 21.5 ± 6.6, and 24.6 ± 6.9 %, respectively. Among the NPs, α-Fe2O3 showed more sensitivity to bacteria than the other two, probably because of its relatively higher value of point of zero charge. It was found that cell-induced and supernatant-induced reductions were combined to achieve added results, in which the supernatants contributed much more than the cells, implying that the bacterial exudates might be more crucial in the reduced virus adsorption than the bacterial cells. These results strongly demonstrated that the bacteria-induced reduction in virus adsorption became more significant with culture age. It is suggested that studies conducted in the absence of bacteria may not accurately evaluate the potential of virus removal efficiency of the NPs in bacteria-containing environments.
Mostrar más [+] Menos [-]Developmental toxicity of carbon nanoparticles during embryogenesis in chicken
2020
Samak, Dalia H. | El-Sayed, Yasser S. | Shaheen, Hazem M. | El-Far, Ali H. | Abd El-Hack, Mohamed E. | Noreldin, Ahmed E. | El-Naggar, Karima | Abdelnour, Sameh A. | Saied, Essa M. | El-Seedi, Hesham R. | Aleya, Lotfi | Abdel-Daim, Mohamed M.
Nanoparticles (NPs) are very small particles present in a wide range of materials. There is a dearth of knowledge regarding their potential secondary effects on the health of living organisms and the environment. Increasing research attention, however, has been directed toward determining the effects on humans exposed to NPs in the environment. Although the majority of studies focus on adult animals or populations, embryos of various species are considered more susceptible to environmental effects and pollutants. Hence, research studies dealing mainly with the impacts of NPs on embryogenesis have emerged recently, as this has become a major concern. Chicken embryos occupy a special place among animal models used in toxicity and developmental investigations and have also contributed significantly to the fields of genetics, virology, immunology, cell biology, and cancer. Their rapid development and easy accessibility for experimental observance and manipulation are just a few of the advantages that have made them the vertebrate model of choice for more than two millennia. The early stages of chicken embryogenesis, which are characterized by rapid embryonic growth, provide a sensitive model for studying the possible toxic effects on organ development, body weight, and oxidative stress. The objective of this review was to evaluate the toxicity of various types of carbon black nanomaterials administered at the beginning of embryogenesis in a chicken embryo model. In addition, the effects of diamond and graphene NPs and carbon nanotubes are reviewed.
Mostrar más [+] Menos [-]Virological and seroepidemiological surveys of type Hsw1N1 influenza on a piggery
1981
Nakamura, K. (Nagano-ken. Research Inst. for Health and Pollution (Japan)) | Nishizawa, S.