[Start-up of Simultaneous ANAMMOX and Denitrification Process and Changes in Microbial Community Characteristics].

To understand the relationship between nitrogen and carbon removal performance and the microbial community during start-up of simultaneous ANAMMOX and denitrification (SAD), nitrogen and carbon removal performance and microbial community change were studied by gradually increasing the influent COD concentration. The results showed that with the increase of the influent COD concentration, NH4+-N and NO2--N effluent remained stable, and the average removal rate was more than 98%. The removal rate of TN increased gradually, and the rate was 95.6% in the third stage, which was 6.8% higher than that of ANAMMOX in theory. ΔNO3--N/ΔNH4+-N decreased significantly from 0.15-0.17 to 0.03-0.07. The contribution rate of ANAMMOX to nitrogen removal decreased gradually, denitrification for nitrogen removal increased gradually, and the COD removal rate increased. Sludge activity analysis showed that the denitrification activity of sludge increased significantly and the ANAMMOX activity decreased slightly after the start-up of SAD. High throughput sequencing results showed that the dominant phyla of microorganisms in the reactor were Chloroflexi, Planctomycetes, Firmicutes, Armatimonadetes, and Proteobacteria. The characteristics of the microbial community in the reactor were closely related to the performance of SAD in nitrogen and carbon removal. The main functional microorganisms related to nitrogen and carbon removal were ANAMMOX bacteria, anaerobic digestive bacteria, and denitrifying bacteria. The abundance of ANAMMOX bacteria decreased after the start-up of SAD, and the anaerobic digestive bacteria and heterotrophic denitrifying bacteria increased significantly.

Incomplete fluid-air exchange technique for idiopathic macular hole surgery.

AIM: To explore an improved procedure involving incomplete fluid-air exchange for idiopathic macular hole (IMH), and the closure rate, visual function, and the visual field of macular holes (MHs) were evaluated. METHODS: This prospective randomized controlled study, included 40 eyes of 40 patients with IMH who were treated with pars plana vitrectomy and peeling of the internal limiting membrane. They were grouped by random digital table. Twenty-one eyes underwent incomplete fluid-air exchange (IFA) and 19 eyes underwent traditional complete fluid-air exchange (CFA) as the control group. Outcomes included best-corrected visual acuity (BCVA), intraocular pressure, and optical coherence tomography, light adaptive electroretinography, and visual field evaluations. RESULTS: All MHs <400 µm were successfully closed. BCVAs before and 6mo after surgery were 0.82±0.41 logMAR and 0.28±0.17 logMAR in IFA group and 0.86±0.34 logMAR and 0.34±0.23 logMAR in CFA group, respectively. The electroretinogram analysis of patients in IFA group revealed increases in b-wave amplitudes at 1, 3, and 6mo after surgery. Additionally, patients in IFA group showed an amplitude increase of 28.6% from baseline at 6mo (P<0.05), while no obvious improvements were noted in CFA group. Although there were no statistically significant improvements in either group, the IFA group showed a slight increase in mean sensitivity (P>0.05). CONCLUSION: IFA is a reliable method that offers comparable closure rate to CFA and facilitates improvements in visual function.