[Performance and Reaction Mechanism of Co(â ¡) Mediated Activation of Peroxymonosulfate for Degrading Nitrilotris (Methylene Phosphonic Acid)].

Co(Ⅱ) mediated activation of peroxymonosulfate (PMS) could degrade phosphonate effectively, whereas the degradation of amino phosphonate remains unclear. Herein, nitrilotris (methylene phosphonic acid) (NTMP) was used as a target pollutant; the degradation mechanism was investigated using the electron paramagnetic resonance spectrum (EPR), free radical trapping experiments, and chemical probe experiments; and the possible degradation pathways of NTMP and the influencing factors were analyzed. The results showed that NTMP was completely degraded within 20 min in the Co(Ⅱ)/PMS system, and 78.3% of NTMP was oxidized to orthophosphate (PO43-) after 60 min of reaction. The Co(Ⅱ)-PMS complex was the main active oxidizing species, whereas 1O2, HO·, and SO4-· contributed little to the oxidation of NTMP in the Co(Ⅱ)/PMS system. A variety of intermediates containing phosphate groups were obtained through the breakage of the C-N bond and C-P bond as NTMP reacted with the Co(Ⅱ)-PMS complex and finally were oxidized to PO43-. With the increase in PMS dosage and Co(Ⅱ) dosage, the generation rate of PO43- during the oxidation process of NTMP was significantly improved. In addition, the presence of HCO3- and natural organic matter (NOM) greatly inhibited the generation of PO43- in the Co(Ⅱ)/PMS system. This study further improved the oxidation mechanism of phosphonate in the Co(Ⅱ)/PMS system and provides a reference for the removal of phosphonate in wastewater.

[Genetic potential analysis of six tilapia populations by microsatellite DNA markers].

Twenty five microsatellite loci were used to analyze two blue tilapia populations ["Xia'ao 1" (ZA), Guangxi population] and four nile tilapia populations [Egypt strain (ZN), 88 strain (XN), Guangxi population (GN), American strain (MN)]. A total of 7775 fragments ranging from 100 bp to 400 bp in length were obtained. Three to eight alleles were amplified in 25 loci and 143 alleles in all the six populations. The average number of alleles in each locus was 5.72. The average values of observed heterozygosity (Ho) ranged from 0.7253 to 0.8160, the average expected heterozygosity (He) ranged from 0.5146 to 0.6834, the average polymorphic information content (PIC) ranged from 0.4212 to 0.6105, and the number of average effective alleles (Ae) ranged from 2.20 to 3.23. The highest genetic similarity index was 0.9130 (between ZA and GA); and the lowest was 0.4352 (between ZA and ZN). The results showed that the four nile tilapia populations contained a high level of genetic potential, and the two blue tilapia populations were moderate.

[Herba Saxifragae cream in treatment of chronic eczema: a randomized controlled trial].

OBJECTIVE: To explore the clinical efficacy of Herba Saxifragae cream (HS), a compound of traditional Chinese herbal medicine, on chronic eczema. METHODS: A total of 42 cases of chronic eczema were randomly divided into HS group (22 cases) and hydrocortisone (HC) group (20 cases). To the HS group, HS was externally applied twice a day continuously for 4 weeks. To the HC group, hydrocortisone was externally applied twice a day continuously for 4 weeks. The total score of symptom score reducing index (SSRI) was calculated before and after treatment in terms of itching degree, lesion shape and lesion area, in the evaluation of the clinical efficacy of HS on chronic eczema. RESULTS: After 2-week treatment, the total response rate of HS group was 77.3%, and the total response rate of HC group was 70.0%. After 4-week treatment, the total response rates were 86.4% and 85.0% in HS and HC groups respectively. There was no statistical difference in total scores of SSRI between the two groups (P>0.05), and neither was there the difference in the score of itching degree, lesion shape and lesion area (P>0.05). CONCLUSION: Herba Saxifragae cream has the same effect as hydrocortisone in treating chronic eczema.