ABSTRACT
Objective To know the effect of nanometer titanium dioxide (nano -TiO2 )on the oxidative stress in zebrafish. Methods A total of 64 zebrafishes were randomly divided into 4 groups with different concentrations of nano -TiO2 exposure,which including control group,low dose group (2 mg/L),moderate dose group (8 mg/L)and high dose group (32 mg/L).The content of MDA,the activities of SOD and ATPase in gill,liver and muscle were measured in 1 0 zebrafishes in each group after 30 d exposure.Histopathological changes of gill,liver and muscle in the remainder fishes were observed.Results The content of Malondialdehyde (MDA)in the fish gill of the moderate and high dose group were significantly higher than that of the control group (P <0.05).The activity of Superoxide dismutase (SOD)in the fish gill of the high dose group was significantly increased compared with the control group (P <0.05).The activities of Adenosine triphosphatase(ATPase)in the fish gill of the moderate and high dose group were significantly decreased compared with the control group (P <0.05).The changes on the content of MDA and the activities of SOD in the fish liver were similar with that in the fish gill after nano -TiO2 exposure,while there was no significant change in the activity of ATPase of the fish liver.And no significant changes were observed in the content of MDA,the activities of SOD and ATPase in the fish muscle (P >0.05 ). Histopathological observation showed infiltration by inflammatory cells, swelling and degeneration, vacuolation and necrosis in zebrafish gill and liver with different degrees.Conclusion Nano -TiO2 exposure could induce the oxidative stress in zebrafish,causing pathological changes in the fish gill and liver.
ABSTRACT
The methyl tertiary butyl ether(MTBE),as an addictive in gasoline,is used widely since the leaded gasoline has been prohibited.By some ways,MTBE can be transferred into water.Since the degradation of MTBE is very slow naturally,the pollution of MTBE in water is attracting more and more attentions.How to remove the MTBE economically and effectively has become a hot spot in common concern.In this paper,the species of photocatalytic degradation technique and the methods were reviewed including UV-Fenton,UV-H2O2,UV-O3,UV-TiO2 and visible-light photocatalytic decomposition with TiO2 were used to degradation of MTBE in water.
ABSTRACT
Objective To study acute toxicity of nanometer titanium dioxide to the liver and kidney of mice. Methods 20 KM mice (22-26 g) were randomly divided into two groups, the control group and the experimental group, TiO2 (20-30 nm) suspension (single dose of 5 g/kg body weight) was given to mice by a single oral gavage, the mice in the control group were given the physiologicalsaline. 14 days after the treatment, the mice were sacrificed and the serum were collected to evaluate the levels of ALT(alanine amino transferase), AST(aspartate aminotransferase), ALP(alkaline phosphatase), UA(uric acid), Cr(creatinine),BUN(blood urea nitrogen), CK(creatine kinase), LDH(lactate-dehydrogenase), ?-HBDH(alpha-hydroxybutyrate dehydrogenase), TBIL(total bilirubin levels). The tissues of the liver and kidney were excised and were embedded in paraffin blocks, hematoxylin-eosin (HE) staining for further histopathological diagnosis. Results The serum ALT, ALT/AST, BUN, LDH and ?-HBDH of the TiO2 group were statistically higher than those in the control group (P