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  • Author: Yan-Jun Zhou x
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Effect of Stubble Heights and Treatment Duration Time on the Performance of Water Dropwort Floating Treatment Wetlands (FTWS)

Floating treatment wetlands (FTWs) with Water Dropwort (Oenanthe javanica) were established in winter to investigate their potential role in the purification of eutrophicated water, and to identify the effects of different stubble heights of the Water Dropwort on the performance of the FTWs. The results of the experiments demonstrated: The Water Dropwort FTWs were effective in buffering the pH of the experimental water. The Water Dropwort FTWs were efficient in purifying eutrophicated water, with removal rate for total nitrogen (TN), total phosphorus (TP), ammonium nitrogen (NH4 + - N), and nitrate nitrogen (NO3 - - N) at 91.3, 58.0, 94.6, and 95.5% in the 15-day experiment, respectively. No significant difference in the purification effect was found among different stubble heights of Water Dropwort FTWs. Significant differences between the zero control and the FTWs were found for the removal of TP in the first 11 days; and for the removal of NH4 + - N in the first 4 days. No significant difference was found between the zero control and the FTWs for NO3 - - N in the first 4 days, but significant difference was detected after day 4. The optimum treatment duration time for the FTWs with Water Dropwort will depend on the nutrients to be removed. These results will provide basis for further application of the FTWs at large scale, as well as for future studies on the mechanism of nutrient removal process.

Abstract

Introduction: A real-time RT-PCR method for identification and quantification of porcine epidemic diarrhoea virus (PEDV) strains in China was developed.

Material and Methods: Based on the conserved sequence of the PEDV nucleocapsid (N) gene, a primer pair and probe were designed to establish a TaqMan-MGB real-time RT-PCR assay for quantitative detection of the virus. The sequence was cloned into the pMD18-T vector and a series of diluted recombinant plasmids were used to generate a standard curve with an R2 value of 0.999.

Results: The developed quantitative PCR assay detected viral titres as low as 0.1 TCID50 with high specificity and no cross-reaction with other porcine viruses (PoRV, TGEV, PRRSV, or CSFV). The intra-batch and inter-batch coefficients of variation were both less than 1%, which indicated good reproducibility. Thirty clinical diarrhoea samples obtained from pigs in Shanghai and Fujian were analysed using this quantitative PCR assay. Out of these samples, 93.3% were found to be PEDV positive.

Conclusion: This approach is suitable for clinical sample identification and pathogenesis studies.

Objective To investigate the prevalence and levels of anti-HEV IgG in the population of Jiangsu Province.

Methods Total of 2 656 samples from Qindong and 11 463 samples from Anfeng were colleted. The anti- HEV antibody was qualitatively and quantitatively detected using ELISA kits and the references had been established.

Results The positive rates of anti-HEV IgG in male and female were 55.6% and 40.1%, respectively. The positive rate of anti-HEV IgM in male and female were both 3.4%. In opposite to anti-HEV IgG, the positive rate of anti-HEV IgM in Anfeng was significant higher than that in Qindong. The mean anti-HEV IgG titers for 6 age groups were 0.94, 0.92, 1.07, 1.46, 1.27, 1.19 and 0.68, 1.31, 1.08, 1.14, 1.31, 1.68 IU/ml, in Qindong and Anfeng region, respectively. The positive rate of anti-HEV IgG tended to increase with age and the titer of anti- HEV IgG was associated with age (R > 0.90).

Conclusions The results in this study showed that HEV was widely prevalent in both Qindong and Anfeng of Jiansu Province and the prevalence and the anti-HEV IgG titer were associated with gender and age.

Abstract

Introduction: Peroxiredoxin 6 (Prdx6) is a bifunctional protein with glutathione peroxidase activity and phospholipase A2 activity. Previous studies have shown a significant positive correlation between the intracellular survival ability of Brucella and Prdx6. Here, the Prdx6 enzyme with a single activity was constructed to facilitate study of the relationship between the single function of Prdx6 and Brucella infection.

Material and Methods: The target open reading frame (ORF) DNAs of Prdx6 with a single active centre were prepared using gene splicing by overlap extension PCR (SOE-PCR), and the recombinant eukaryotic expression plasmids inserted by Prdx6 with the single activity centre were constructed and transfected into murine Raw264.7 macrophages. The glutathione peroxidase activity and phospholipase A2 activity of the constructed Prdx6 were examined.

Results: The core centres (Ser32 and Cys47) of Prdx6 were successfully mutated by changing the 94th nucleotide from T to G and the 140th nucleotide from G to C in the two enzyme activity cores, respectively. The constructed recombinant plasmids of Prdx6 with the single active centre were transfected into murine macrophages showing the expected single functional enzyme activity, which MJ33 or mercaptosuccinate inhibitors were able to inhibit.

Conclusion: The constructed mutants of Prdx6 with the single activity cores will be a benefit to further study of the biological function of Prdx6 with different enzyme activity.