Metagenomic insights into responses of microbial population and key functional genes to fulvic acid during partial nitritation

The long-term impact of fulvic acid(FA)on partial nitritation(PN)systemwas initially examined in this study.The obtained results revealed that the FA lower than 50 mg/L had negligible effect on the nitrite accumulation rate(NAR nearly 100%)and ammonium removal rate(ARR 56.85%),while FA over 50 mg/L decreased ARR from 56.85%to 0.7%.Sludge characteristics analysis found that appropriate FA(<50 mg/L)exposure promoted the settling performance and granulation of PN sludge by removing Bacteroidetes and accumulating Chloroflexi.The analysis of metagenomics suggested that the presence of limited FA(0-50 mg/L)stimulated the generation of NADH,which favors the denitrification and nitrite reduction.The negative impact of FA on the PN system could be divided into two stages.Initially,limited FA(50-120 mg/L)was decomposed by Anaerolineae to stimulate the growth and propagation of heterotrophic bacteria(Thauera).Increasing heterotrophs competed with AOB(Nitrosomonas)for dissolved oxygen,causing AOB to be eliminated and ARR to declined.Subsequently,when FA dosage was over 120 mg/L,Anaerolineae were inhibited and heterotrophic bacteria reduced,resulting in the abundance of AOB recovered.Nevertheless,the ammonium transformation pathway was suppressed because genes amoABC and hao were obviously reduced,leading to the deterioration of reactor performance.Overall,these results provide theoretical guidance for the practical application of PN for the treatment of FA-containing sewage.

MR-guided laser interstitial thermal therapy for drug-resistant lesional epilepsy:a single-center experience

Background To describe and report the efficacy and safety of MR-guided laser interstitial thermal therapy(MRgLITT)in the treatment of drug-resistant epilepsy.Methods A retrospective review of all MRgLITT procedures in our hospital was performed.All procedures were performed using a surgical laser ablation system.Demographic and outcome data were compiled and analyzed.Results A total of 19 patients underwent MRgLITT procedures from June 2021 to November 2021.The average age at surgery was 18.1 years(3-61.4 years).The average length of hospitalization post-surgery was 4.95 days(4-7 days).Surgical substrates included 8 patients with hypothalamic hamartomas,5 with medial temporal lobe epilepsy,3 with deep focal cortical dysplasia,1 with tuberous sclerosis,1 with a cavernous malformation,and 1 with Lennox-Gastaut syndrome who underwent anterior corpus callosotomy.Complications occurred in three patients.After an average follow-up of 1 year,6 patients were seizure-free(Engel I,31.6%),1 had significant seizure control(Engel II,5.3%),7 had seizure control(Engel III,36.8%),and 5 had no improvement in their seizures(Engel IV,26.3%).Fisher’s exact tests did not reveal statistical significance for the association between Engel class outcome and epileptic disease.Conclusion This study confirmed that MRgLITT,as a method for treating drug-resistant epilepsy,is minimally invasive,safe,and efficient and that it can reduce the incidence of surgery-related complications.