Biochar promoted microbial iron reduction in competition with methanogenesis in anaerobic digestion.

Microbial Fe (III) reduction generally could outcompete methanogenesis due to its thermodynamic advantage, while the low bioavailability of Fe (III) compounds limits this process in the anaerobic digestion system, which could result in the low recovery of vivianite. Therefore, this study investigated the competition between Fe (III) reduction and methanogenesis in the presence of different biochar (pyrochar and hydrochar). The results showed that pyrochar obtained at 500 °C (P5) resulted in the highest Fe (III) reduction (80.3%) compared to the control experiment (29.1%). P5 also decreased methane production by 9.4%. Both conductivity and surface oxygen-containing functional groups contributed to the promotion of direct electron transfer for Fe (III) reduction. Genomic-centric metatranscriptomics analysis showed that P5 led to the highest enrichment of Geobacter soli A19 and induced the significant expression of out membrane cytochrome c and pilA in Geobacter soli A19, which was related to higher Fe (III) reduction.

Effect of transcutaneous electrical acupoint stimulation on postoperative pain in pediatric orthopedic surgery with the enhanced recovery after surgery protocol: a prospective, randomized controlled trial.

STUDY OBJECTIVE: To evaluate the safety and effectiveness of transcutaneous electrical acupoint stimulation (TEAS) in postoperative analgesia following pediatric orthopedic surgery with the enhanced recovery after surgery (ERAS) protocol. DESIGN: Prospective randomized controlled trial. SETTING: The Seventh Medical Center of the Chinese People's Liberation Army General Hospital. PARTICIPANTS: Eligible participants were children aged 3-15 years who were scheduled to undergo orthopedic surgery of the lower extremities under general anesthesia. INTERVENTIONS: A total of 58 children were randomly allocated into two groups: TEAS (n = 29) and sham-TEAS (n = 29). The ERAS protocol was used in both groups. In the TEAS group, the bilateral Hegu (LI4) and Neiguan (PC6) acupoints were stimulated starting from 10 min before anesthetic induction until the completion of surgery. In the sham-TEAS group, the electric stimulator was also connected to the participants; however, electrical stimulation was not applied. MEASURES: The primary outcome was the severity of pain before leaving the post-anesthesia care unit (PACU) and at postoperative 2 h, 24 h, and 48 h. Pain intensity was measured with the Faces Pain Scale-Revised (FPS-R). RESULTS: None of the participants had any TEAS-related adverse reactions. In comparison with the sham-TEAS group, FPS-R scores in the TEAS group were significantly decreased before leaving the PACU and at postoperative 2 h and 24 h (p < 0.05). The incidence of emergence agitation, intraoperative consumption of remifentanil, and time to extubation were significantly reduced in the TEAS group. Furthermore, the time to first press of the patient-controlled intravenous analgesia (PCIA) pump was significantly longer, the pressing times of the PCIA pump in 48 h after surgery was significantly decreased, and parental satisfaction was significantly improved (all p < 0.05). CONCLUSION: TEAS may safely and effectively relieve postoperative pain and reduce the consumption of perioperative analgesia in children following orthopedic surgery with the ERAS protocol. TRIAL REGISTRATION: Chinese Clinical Trial Registry (ChiCTR2200059577), registered on May 4, 2022.

Four cypermethrin isomers induced stereoselective metabolism in H295R cells.

Cypermethrin (CP) is widely used for controlling agricultural and indoor vermin. Previous studies have reported the stereoselective difference of CP in biological activities. However, little is known about their potential mechanisms between metabolic phenotypes and endocrine-disrupting effects. Herein, nuclear magnetic resonance (NMR)-based metabolomics combining metabolite identification and pathway analysis were applied to evaluate the stereoselective metabolic cdisorders induced by CP isomers in human adrenocortical carcinoma cells (H295R) culture medium. Then, gene expression levels related to disturbed metabolic pathways were assessed to verify according to metabolic phenotypes. Metabolomics profiles showed that [(S)-cyano(3-phenoxyphenyl)methyl](1R,3R)-3-(2,2-dichloroethenyl)-2,2-dimethylcyclopropane-1-carboxylate [(1R,3R,αS)-CP] induced the most significant changes in metabolic phenotypes than did the other stereoisomers. There are 10 differential metabolites (isoleucine, valine, leucine, ethanol, alanine, acetate, aspartate, arginine, lactate, and glucose) as well as two significantly disturbed pathways, including "pyruvate metabolism" and "alanine, aspartate, and glutamate metabolism," that were confirmed in H295R cells culture medium of (1R,3R,αS)-CP compared with other stereoisomers. Polymerase chain reaction (PCR) array also confirmed the results of metabolomics. Our results can help to understand the potential mechanisms between the isomer selectivity in metabolic phenotypes and endocrine-disrupting effects. Data provided here not only lend authenticity to the cautions issued by the scientists and researchers but also offer a solution for the balance between environment and political regulations.

Whether glycine betaine improves the thermotolerance of mesophilic anammox consortia.

While the application of mesophilic anammox process is currently the state of the art, the feasibility of a thermophilic anammox bioprocess is still unclear. In this study, we investigate whether glycine betaine (GB) addition can enhance the thermotolerance of mesophilic anammox biomass in the upflow anaerobic sludge blanket (UASB) reactors fed with synthetic wastewater at a nitrogen loading of approximately 4 kg N m-3 d-1. The results showed that during a long-term operation at 45°C with GB (0, 0.1, 1, 2 mM) addition, anammox performance became worse with the final effluent concentrations of NO2 -N of 145 ± 11.6 mg L-1 and nitrogen removal efficiency decreased from 92.3-6.9%. Specific anammox activity decreased from 392.1 ± 12.1-6.0 ± 0.8 mg N g-1 VSS d-1, which were not significantly higher than those in the control reactor. The content of heme c showed a stronger downward trend in T1 (with GB addition) than in the control reactor T0. The qPCR results showed that the relative abundance of Candidatus Kuenenia decreased in both the experimental (from 53.5-28.8%) and control reactors (from 54.1-35.1%). Overall, continuous addition of exogenous GB did not improve the thermotolerance of mesophilic anammox consortia at 45°C.

Unraveling the impact of nanoscale zero-valent iron on the nitrogen removal performance and microbial community of anammox sludge.

Given the increasing use of nanoscale zero-valent iron (NZVI) particles for environmental remediation and wastewater treatment, their potential impact on anaerobic ammonium oxidation (anammox) bacteria was investigated in this study using anammox sludge. Batch assays showed that NZVI concentrations up to 200mgL-1 did not affect anammox activity, reactive oxygen species production, and cell membrane integrity. The nitrogen removal efficiency of the continuous-flow reactor fluctuated in the presence of 20 or 50mgL-1 NZVI, but it could return to normal over time, even at 200mgL-1 NZVI. 16S rDNA-based high-throughput sequencing indicated that although the presence of 10, 20, 50, and 200mgL-1 NZVI to some extent affected microbial composition, the anammox bacteria (Candidatus Kuenenia) never lost its dominance. The abundance of gene families that are related to the assimilation and utilization of iron was down-regulated in response to the stress of high-level NZVI.