在20、15和10℃条件下长期运行SBR,分析温度对反应器性能、硝化动力学和硝化菌群落结构等的影响.实验结果表明,随着温度的降低,比氨氧化速率(SAUR)逐渐降低,比亚硝酸盐氧化速率(SNUR)没有显著变化,氨氧化菌(AOB)和亚硝酸盐氧化茵(NOB)的长期温度修正系数分别为1.078和1.0078,NOB的低温适应性强于AOB;定量PCR结果显示,AOB丰度随着温度的降低而下降,而NOB丰度没有明显变化;但NOB中嗜冷菌Nitrotoga随着温度的降低而逐渐增加,并取代Nitrospira成为NOB的优势茵属,从而在一定程度上缓解因Nitrospira减少而引起的SNUR降低.因此,NOB群落结构由Nitrospira向Nitrotoga迁移是其适应低温环境的关键.

Background: Coronavirus disease 2019 (COVID-19) is a public health emergency of international concern and poses a threat to the mental health of pregnant women. Aim: The purpose of this study was to investigate the relationship between social support and anxiety, and the mediating effect of risk perception during the COVID-19 epidemic in the third trimester pregnant women in Qingdao, China. Methods: From 16 to 21 February 2020, an online survey was conducted, which collected the information on demographic data, anxiety, social support and risk perception to COVID-19 of women with established medical records in the ambulatory of the Department of Obstetrics at the Affiliated Hospital of Qingdao University. Anxiety was assessed by the Self-Rating Anxiety Scale (SAS), social support was assessed by the Social Support Rating Scale (SSRS) and risk perception was assessed by a self-designed questionnaire. Results: This study had 308 participants with an average of 31.02 ± 3.91 years. During the period of prevention and control of the epidemic, most pregnant women adopted protective measures, such as wearing masks (97.4%), washing hands frequently (88.3%) and staying at home (76.3%). The average SAS, SSRS and risk perception scores of the participants were 42.45 ± 6.98, 44.60 ± 7.00 and 21.60 ± 5.74, respectively. The total effect of maternal social support on anxiety was −2.63 (95% confidence interval (CI): −4.40 ~ −1.44, p < .001), the direct effect was −1.44 (95% CI: −2.74 ~ −0.35, p < .05) and the indirect effect was −1.19 (95% CI: −2.49 ~ −0.51, p < .001). Conclusion: The third trimester pregnant women had a high level of social support, a medium level of risk perception to COVID-19 and were susceptible to anxiety. Risk perception played a mediating role between social support and anxiety.

Two sequencing batch reactors (SBRs) were operated for 100days under aerobic conditions, with one being fed with unsterilized municipal wastewater (USBR), and the other fed with sterilized municipal wastewater (SSBR). Respirometric assays and fluorescence in situ hybridization (FISH) results show that active nitrifiers were present in the unsterilized influent municipal wastewater. The maximum ammonia utilization rate (AUR) and nitrite utilization rate (NUR) of the unsterilized influent were 0.32±0.12mg NH4+-N/(L·hr) and 0.71±0.18mg NO2--N/(L·hr). Based on the maximum utilization rates, the estimated seeding intensity for the ammonia oxidizing bacteria (AOB) and nitrite oxidizing bacteria (NOB) of the USBR was 0.08g AOB/(g AOB·day) and 0.20g NOB/(g NOB·day) respectively. The fraction of nitrifiers/total bacteria in the influent was 5.35%±2.1%, the dominant AOB was Nitrosomonas spp., Nitrosococcus mobilis hybridizated with Nsm156, and the dominant NOB was Nitrospira hybridizated with Ntspa662. The influent nitrifiers potentially seeded the activated sludge of the bioreactor and hence demonstrated a mitigation of the acclimatization times and instability during start-up and early operation. The AUR and NUR in the USBR was 15% and 13% higher than the SSBR respectively during the stable stage, FISH results showed that nitrifiers population especially the Nitrospira in the USBR was higher than that in the SSBR. These results indicate that the natural continuous immigration of nitrifiers from municipal influent streams may have some repercussions on the modeling and design of bioreactors.

Both a nitrifying sequencing batch reactor (SBR) and a completely stirred tank reactor (CSTR) were operated under aerobic conditions. Microbial populations of both reactors were examined via fluorescent in situ hybridization (FISH) and kinetic properties such as ammonium/nitrite utilization rate and half-saturation constants (K-S) were investigated. In the SBR, dominant ammonia-oxidizing bacteria (AOB) and nitrite-oxidizing bacteria (NOB) were rapid growth r-strategists (Nitrosomonas europaea and Nitrobacter). However, in the CSTR, the dominant AOB and NOB were slow growth K-strategists (Nitrosospira and Nitrospira). The half-saturation constants of AOB and NOB were 3.01 +/- 0.97 and 4.22 +/- 0.64 mg/L, respectively, for the SBR and 0.43 +/- 0.19 and 2.15 +/- 0.64 mg/L, respectively, for the CSTR. The nitrification rate of the SBR was 63% higher than that in the CSTR. The reactor configuration shows an evident selectivity for K/r-strategists. Thus, the difference in nitrification rates between the SBR and CSTR are likely caused by the combination of chemical reaction engineering kinetics and nitrifier communities.

Sludge liquor (reject water) is one of the by-products of the water resource recovery facilities (WRRFs),it has relative high temperature,high ammonia concentration and may increase the nitrogen loading of the WRRFs.Bioaugmentation with nitrifiers enriched by sludge liquor is a promised way to enhance nitrification performance of the water resource recovery facilities (WRRF).While nitrifiers are temperature sensitive,the effect of nitrifier enrichment may affected by temperature.In this study,nitrifiers were accumulated in an SBR at high ammonia loading (1.20 kg · (m3 · d)-1) at 25 ℃ and 30 ℃,then the enriched nitrifier community and the kinetic performances were investigated by fluorescence in situ hybridization (FISH) and respirometric assays.FISH results showed that r-strategists (Nitrosomonas europaea,Nitrobacter) increased with temperature.The kinetic parameters showed that the maximum substrate utilization rate and the half saturation constant for substrate of ammonia oxidized bacteria (AOB) increased with temperature,while the opposite trend was shown with nitrite oxidized bacteria (NOB) mainly due to severe free nitrous acid (FNA) inhibition under high temperature.Besides,it didn't have significant difference between the half saturation constant for oxygen of nitrifiers at 25 ℃ and 30 ℃.

A nitrifying sequencing batch reactor (SBR) and continuous stirred-tank reactor (CSTR) were operated at 15℃ under the same conditions to investigate the effect of two typical flow patterns (plug flow and complete mixing) on the efficiency of nitrification enhancement. The results show that, during bioaugmentation, the ammonia utilized rate(AUR)and nitrite utilized rate(NUR)in the SBR were 2.34 and 2.39 times of that before bioaugmentation, and after bioaugmentation ceased, the AUR and NUR slightly decreased to 2.01 and 1.78 times of that before bioaugmentation. Meanwhile, the AUR and NUR in the CSTR were 2.63 and 2.44 times that before bioaugmentation, and after bioaugmentation ceased, the AUR and NUR decreased to 1.48 and 1.31 times that before bioaugmentation. Fluorescence In-Situ Hybridization (FISH) results showed that during bioaugmentation, the ammonia oxidizing bacteria (AOB) and nitrite oxidizing bacteria (NOB) in the SBR were 2.67 and 2.71 times of that before bioaugmentation, and after bioaugmentation ceased, the AUR and NUR slightly decreased to 2.14 and 1.95 times that before bioaugmentation. Meanwhile, the AUR and NUR in the CSTR were 2.91 and 1.77 times of that before bioaugmentation, and after bioaugmentation ceased, the AUR and NUR decreased to 1.25 and 1.50 times of that before bioaugmentation. Therefore, the efficiency of nitrification enhancement was similar between the two types of flow patterns during bioaugmentation, but the seeded nitrifiers were much more vulnerable to wash out in the CSTR than that in the SBR due to r/K selectivity of the flow patterns.

OBJECTIVESThis study is to determine if green tea (Camellia sinensis) extracts (GTE) affects adipogenesis and further investigate the related molecular mechanisms.METHODSPatients with metabolic syndrome were recruited in this study. Of them, 70 patients received GTE and 64 received water to serve as the control group. The human serum adiponectin, visfatin, and leptin concentrations were determined by enzyme-linked immunosorbent assay. Adipogenesis of 3T3-L1 preadipocytes was induced with reagents and then the cells were treated with GTE. The lipids were stained with Oil Red O for analysis of adipogenesis of 3T3-L1 preadipocytes. The 3T3-L1 preadipocytes were treated with increasing concentrations (0.2-0.5%, w/v) of GTE for 2 days and the cell viability was determined by MTT assay. Reverse transcription real-time PCR and immunoblotting assays were performed to determine RNA and protein levels of relative molecules.RESULTSGTE increases the serum concentrations of adiponectin but decreases visfatin levels in patients received GTE. The leptin concentrations in serum were not significantly affected. The GTE reduces the adipogenesis-induced lipid accumulation in 3T3-L1 preadipocytes. GTE decreases the mRNA and protein expression of adipogenic transcription factors C/EBPα and PPARγ in 3T3-L1 cells. Expression levels of the adipocyte-specific genes encoding adipocyte protein 2, lipoprotein lipase, and glucose transporter 4 were also decreased by GTE. Furthermore, it was found that GTE reduces phosphorylation of Akt during adipocyte differentiation.CONCLUSIONSGTE reduces adipogenesis by decreasing expression of transcription factors C/EBPα and PPARγ by reduction of phosphorylation of Akt during adipocyte differentiation.