[Remediation of Three Oxidants on Polycyclic Aromatic Hydrocarbons in Coking Contaminated Soil and Its Response to Indigenous Microorganisms].

To explore the influences of chemical oxidation on the physiological and ecological functions of indigenous microorganisms during contaminated soil remediation, three oxidants, including KMnO4, Na2S2O8, and O3, were selected to investigate their remediation effects on PAHs and the responses to indigenous microorganisms under different liquid-solid ratios, in this study. The results showed that:when the ΣPAHs concentration was 679.1 mg·kg-1 and the dosage of KMnO4 and Na2S2O8 was 1%, the removal efficiency of ΣPAHs reached up to 96.9% and 95.7% under the liquid-solid ratio of 6:1; for the O3 treatment, the removal efficiency of ΣPAHs was the highest(82.3%) at the O3 dosage and the liquid-solid ratio of 72 mg·min-1 and 8:1, respectively. The removal efficiency of low ring(3-4 rings) PAHs was higher than that of high ring(5-6 rings) PAHs under different liquid-solid ratios. The highest removal efficiencies were observed for phenanthrene and acenaphthene, whereas for benzo[a]pyrene, only the KMnO4treatment provided an effective performance, showing the highest removal efficiency of 97.4%. The microbial quantity analysis indicated that the quantity of soil microorganisms in the soil dropped sharply after being treated with KMnO4, decreasing from 108 copies·g-1 to 105 copies·g-1, whereas it changed only slightly after being treated with Na2S2O8 and O3. The community structure analysis showed that Proteobacteria were predominant in the contaminated soil, with the relative abundance of 99.5%. The addition of KMnO4 and Na2S2O8 significantly increased the microbial diversity; in particular, the relative abundance of a variety of microorganisms(such as Ralstonia and Acinetobacter) that can degrade PAHs was remarkably increased. The analysis of microbial metabolic function pathways revealed that chemical oxidation could simultaneously increase the relative abundance of PAHs-degrading bacteria and improve the ability of organic metabolism. Overall, the KMnO4 treatment greatly altered the quantity of microorganisms and the structure of the microbial community and the relative abundance of PAHs-degrading microorganisms at the liquid-solid ratio of 6:1.

Explore combined use of transcranial direct current stimulation and cognitive training on executive function after stroke.

OBJECTIVE: To explore the effects of transcranial direct current stimulation combined with cognitive training on executive function and activities of daily living performance among stroke patients. METHODS: A total of 50 subjects were enrolled and randomly allocated into 2 groups of 25 each. The real-transcranial direct current stimulation group was simultaneously subjected to transcranial direct current stimulation and cognitive training, while the sham-transcranial direct current stimulation group was simultaneously subjected to sham transcranial direct current stimulation and cognitive training. At baseline, and after treatment, each subject was assessed with the Wisconsin Card Sorting Test (WCST), Stroop Color-Word Test (SCWT), Digital Symbol Test (DST), Mini-mental State Examination (MMSE), Montreal Cognitive Assessment (MoCA) and Activities of Daily Living Scale (ADLs). RESULTS: After treatment, the gains in most indices of WCST, SCWT, DST, MMSE, MoCA and ADLs in the real-transcranial direct current stimulation group were significantly higher than those in the sham-transcranial direct current stimulation group (p<0.05). Nonetheless, no significant differences were noted in the gains in SCWT (including only Part A time and error, and Part B time) and activities of daily living (including only basic activities of daily living) between the 2 groups (p>>0.05). CONCLUSION: Transcranial direct current stimulation combined with cognitive training was found to significantly enhance executive function and instrumental activities of daily living performance among stroke patients.