Molecular characterization of the IgH locus and V(D)J recombination in large yellow croaker (Larimichthys crocea).

V(D)J recombination is crucial for generating a diverse repertoire of immunoglobulins. Although the V(D)J recombination process has been well characterized in mammals, this process remains largely unexplored in teleosts. In this study, we comprehensively analyzed the IgH locus of a marine fish species large yellow croaker (Larimichthys crocea), and identified 28 V, 19 D, and 8 J gene segments, following a pattern of V-Dζ-Jζ-Cζ-Dµ-Jµ-Cµ1-Cµ2. The V, D, and J gene segments are flanked by consensus recombination signal sequences, with spacer lengths similar to those observed in mammals. The V gene segments are categorized into three distinct families, and exhibited a higher sequence identity compared to those in mammals. Additionally, we designed a set of primers for the examination of the V(D)J recombination in large yellow croaker. RNA-seq analysis showed increased expression of genes related to immunoglobulin production and lymphocyte chemotaxis in IgM + B cells upon Pseudomonas plecoglossicida infection, accompanied by altered expression of V gene segments, suggesting their involvement in the response to P. plecoglossicida infection. Taken together, we identified the IgH locus and V(D)J recombination process of large yellow croaker, which contribute to the understanding of immunoglobulin production and B cell immunity in teleosts, and may provide insights into vaccine development in large yellow croaker.

Short-term sedimentary evidence for increasing diatoms in Arctic fjords in a warming world.

Arctic fjords are hotspots of marine carbon burial, with diatoms playing an essential role in the biological carbon pump. Under the background of global warming, the proportion of diatoms in total phytoplankton communities has been declining in many high-latitude fjords due to increased turbidity and oligotrophication resulting from glacier melting. However, due to the habitat heterogeneity among Svalbard fjords, diatom responses to glacier melting are also expected to be complex, which will further lead to changes in the biological carbon pumping and carbon sequestration. To address the complexity, three short sediment cores were collected from three contrasting fjords in Svalbard (Krossfjorden, Kongsfjorden, Gronfjorden), recording the history of fjord changes in recent decades during significant glacier melting. The amino acid molecular indicators in cores K4 and KF1 suggested similar organic matter degradation states between these two sites. In contrast to the turbid Kongsfjorden and Gronfjorden, preserved fucoxanthin in Krossfjorden indicated a continuous increase in diatoms since the mid-1980s, corresponding to a 59 % increase in biological carbon pumping, as quantified by the δ13C of sedimentary organic carbon. The increasing biological carbon pumping in Krossfjorden is further attributed to its hard rock types in the glacier basin, compared to Kongsfjorden and Gronfjorden, which are instead covered by soft rocks, as confirmed by a one-dimensional model. Given the distribution of rock types among basins in Svalbard, we extrapolate our findings and propose that approximately one-fifth of Svalbard's fjords, especially those with hard rock basins and persistent marine-terminated glaciers, still have the potential for an increase in diatom fractions and efficient biological carbon pumping. Our findings reveal the complexity of fjord phytoplankton responses and biological carbon pumping to increasing glacier melting, and underscore the necessity of modifying Arctic marine carbon feedback to climate change based on results from fjords underlain by hard rocks.

Strengthening the enrichment of anaerobic ammonia oxidizing bacteria in biofilms through sludge concentration control.

Controlling sludge concentration is an effective means to achieve PN. In this article, the reactor used domestic sewage as raw water and promoted the high enrichment of anammox bacteria by controlling the MLVSS of flocs to 1000-1500 mg/L and increasing the concentration of filler sludge. The measures to reduce the concentration of flocculent sludge increased the proliferation rate of the biofilm and provided sufficient substrate for AnAOB. After 102 days of operation, the abundance of Candidatus Brocadia increased from 0.43% during inoculation to 23.56% in phase VI. The ability of the microbial community to utilize energy metabolism and produce ATP was significantly improved, and the appropriate distribution of anammox bacteria and nitrifying, denitrifying bacteria in the ecological niche led to its high enrichment. In summary, this study proposes a strategy to promote the high enrichment of anammox bacteria in mainstream domestic sewage without adding any chemicals.

Association of age at diagnosis of diabetes with subsequent risk of age-related ocular diseases and vision acuity.

BACKGROUND: The importance of age on the development of ocular conditions has been reported by numerous studies. Diabetes may have different associations with different stages of ocular conditions, and the duration of diabetes may affect the development of diabetic eye disease. While there is a dose-response relationship between the age at diagnosis of diabetes and the risk of cardiovascular disease and mortality, whether the age at diagnosis of diabetes is associated with incident ocular conditions remains to be explored. It is unclear which types of diabetes are more predictive of ocular conditions. AIM: To examine associations between the age of diabetes diagnosis and the incidence of cataract, glaucoma, age-related macular degeneration (AMD), and vision acuity. METHODS: Our analysis was using the UK Biobank. The cohort included 8709 diabetic participants and 17418 controls for ocular condition analysis, and 6689 diabetic participants and 13378 controls for vision analysis. Ocular diseases were identified using inpatient records until January 2021. Vision acuity was assessed using a chart. RESULTS: During a median follow-up of 11.0 years, 3874, 665, and 616 new cases of cataract, glaucoma, and AMD, respectively, were identified. A stronger association between diabetes and incident ocular conditions was observed where diabetes was diagnosed at a younger age. Individuals with type 2 diabetes (T2D) diagnosed at < 45 years [HR (95%CI): 2.71 (1.49-4.93)], 45-49 years [2.57 (1.17-5.65)], 50-54 years [1.85 (1.13-3.04)], or 50-59 years of age [1.53 (1.00-2.34)] had a higher risk of AMD independent of glycated haemoglobin. T2D diagnosed < 45 years [HR (95%CI): 2.18 (1.71-2.79)], 45-49 years [1.54 (1.19-2.01)], 50-54 years [1.60 (1.31-1.96)], or 55-59 years of age [1.21 (1.02-1.43)] was associated with an increased cataract risk. T2D diagnosed < 45 years of age only was associated with an increased risk of glaucoma [HR (95%CI): 1.76 (1.00-3.12)]. HRs (95%CIs) for AMD, cataract, and glaucoma associated with type 1 diabetes (T1D) were 4.12 (1.99-8.53), 2.95 (2.17-4.02), and 2.40 (1.09-5.31), respectively. In multivariable-adjusted analysis, individuals with T2D diagnosed < 45 years of age [ß 95%CI: 0.025 (0.009,0.040)] had a larger increase in LogMAR. The ß (95%CI) for LogMAR associated with T1D was 0.044 (0.014, 0.073). CONCLUSION: The younger age at the diagnosis of diabetes is associated with a larger relative risk of incident ocular diseases and greater vision loss.

Highly Specific Sulfadiazine Detection Using a Two-Dimensional Europium-Organic Coordination Polymer.

Sulfadiazine (SFZ) is an inexpensive large-consumption antibiotic used for treat bacterial infections but an excess of residues in food can be harmful. Fast and specific luminescence detection of SFZ is highly challenging because of the interference of structurally similar antibiotics. In this work, we develop a two-dimensional europium-organic coordination polymer with excellent luminescence and water stability for highly specific detection of SFZ in the range of 0-0.2 mM. Structural analysis shows that the high stability of coordination polymer is due to the high coordination number of europium ion and the special chelating coordination structure of ligand. The experiment results revealed that the high selectivity and effectively luminescence quenched behaviour of coordination polymer toward SFZ is caused by highly efficient inner filter effect.

DNA methylation regulates B cell activation via repressing Pax5 expression in teleost.

In mammals, the transcription factor Pax5 is a key regulator of B cell development and maturation and specifically expressed in naive/mature B cells but repressed upon B cell activation. Despite the long-standing proposal that Pax5 repression is essential for proper B cell activation, the underlying mechanisms remain largely elusive. In this study, we used a teleost model to elucidate the mechanisms governing Pax5 repression during B cell activation. Treatment with lipopolysaccharide (LPS) and chitosan oligosaccharide (COS) significantly enhanced the antibody secreting ability and phagocytic capacity of IgM+ B cells in large yellow croaker (Larimichthys crocea), coinciding with upregulated expression of activation-related genes, such as Bcl6, Blimp1, and sIgM, and downregulated expression of Pax5. Intriguingly, two CpG islands were identified within the promoter region of Pax5. Both CpG islands exhibited hypomethylation in naive/mature B cells, while CpG island1 was specifically transited into hypermethylation upon B cell activation. Furthermore, treatment with DNA methylation inhibitor 5-aza-2'-deoxycytidine (AZA) prevented the hypermethylation of CpG island1, and concomitantly impaired the downregulation of Pax5 and activation of B cells. Finally, through in vitro methylation experiments, we demonstrated that DNA methylation exerts an inhibitory effect on promoter activities of Pax5. Taken together, our findings unveil a novel mechanism underlying Pax5 repression during B cell activation, thus promoting the understanding of B cell activation process.

Regulation of Coordination Chemistry for Ultrastable Layered Oxide Cathode Materials of Sodium-Ion Batteries.

Layered transition-metal (TM) oxide cathodes have attracted growing attention in sodium-ion batteries (SIBs). However, their practical implementation is plagued by Jahn-Teller distortion and irreversible cation migration, leading to severe voltage decay and structure instability. Herein, O3-Na0.898K0.058Ni0.396Fe0.098Mn0.396Ti0.092O2 (KT-NFM) is reported as an ultrastable cathode material via multisite substitution with rigid KO6 pillars and flexible TiO6 octahedra. The K pillars induce contracted TMO2 slabs and their strong Coulombic repulsion to inhibit Ni/Fe migration; and Ti incorporation reinforces the hybridization of Ni(3deg*)-O(2p) to mitigate the undesired O3-O'3 phase transition. These enable the reversible redox of Ni2+↔Ni3 . 20+ and Fe3+↔Fe3.69+ for 138.6 mAh g-1 and ultrastable cycles with >90% capacity retention after 2000 cycles in a pouch cell of KT-NFM||hard carbon. This will provide insights into the design of ultrastable layered cathode materials of sodium-ion batteries and beyond.

Soil microorganisms and methane emissions in response to short-term warming field incubation in Svalbard.

Introduction: Global warming is caused by greenhouse gases (GHGs). It has been found that the release of methane (CH4) from Arctic permafrost, soil, ocean, and sediment is closely related to microbial composition and soil factors resulting from warming over several months or years. However, it is unclear for how long continuous warming due to global warming affects the microbial composition and GHG release from soils along Arctic glacial meltwater rivers. Methods: In this study, the soil upstream of the glacial meltwater river (GR) and the estuary (GR-0) in Svalbard, with strong soil heterogeneity, was subjected to short-term field incubation at 2°C (in situ temperature), 10°C, and 20°C. The incubation was carried out under anoxic conditions and lasted for few days. Bacterial composition and CH4 production potential were determined based on high-throughput sequencing and physiochemical property measurements. Results: Our results showed no significant differences in bacterial 16S rRNA gene copy number, bacterial composition, and methanogenic potential, as measured by mcrA gene copy number and CH4 concentration, during a 7- and 13-day warming field incubation with increasing temperatures, respectively. The CH4 concentration at the GR site was higher than that at the GR-0 site, while the mcrA gene was lower at the GR site than that at the GR-0 site. Discussion: Based on the warming field incubation, our results indicate that short-term warming, which is measured in days, affects soil microbial composition and CH4 concentration less than the spatial scale, highlighting the importance of warming time in influencing CH4 release from soil. In summary, our research implied that microbial composition and CH4 emissions in soil warming do not increase in the first several days, but site specificity is more important. However, emissions will gradually increase first and then decrease as warming time increases over the long term. These results are important for understanding and exploring the GHG emission fluxes of high-latitude ecosystems under global warming.

PP2C phosphatases Ptc1 and Ptc2 dephosphorylate PGK1 to regulate autophagy and aflatoxin synthesis in the pathogenic fungus Aspergillus flavus.

IMPORTANCE: Aspergillus flavus is a model filamentous fungus that can produce aflatoxins when it infects agricultural crops. This study evaluated the protein phosphatase 2C (PP2C) family as a potential drug target with important physiological functions and pathological significance in A. flavus. We found that two redundant PP2C phosphatases, Ptc1 and Ptc2, regulate conidia development, aflatoxin synthesis, autophagic vesicle formation, and seed infection. The target protein phosphoglycerate kinase 1 (PGK1) that interacts with Ptc1 and Ptc2 is essential to regulate metabolism and the autophagy process. Furthermore, Ptc1 and Ptc2 regulate the phosphorylation level of PGK1 S203, which is important for influencing aflatoxin synthesis. Our results provide a potential target for interdicting the toxicity of A. flavus.

Whole-Voltage-Range Solid-Solution Reaction in Layered Oxide Cathode of Sodium-Ion Batteries.

Layered manganese-based oxides (LMOs) are promising cathode materials for sodium-ion batteries (SIBs) due to their versatile structures. However, the Jahn-Teller effect of Mn3+ induces severe distortion of MnO6 octahedra, and the resultant low symmetry is responsible for the gliding of MnO2 layers and then inferior multiple-phase transitions upon Na+ extraction/insertion. Here, hexagonal P2-Na0.643 Li0.078 Mn0.827 Ti0.095 O2 is synthesized through the incorporation of Li and Ti into the distorted orthorhombic P'2-Na0.67 MnO2 to function as a phase-transition-free oxide cathode. It is revealed that Li in both the transition-metal and Na layers enhances the covalency of Mn-O bonds and allows degeneracy of Mn 3d eg orbitals to favor the formation of hexagonal phase, and the high strength of Ti-O bonds reduces the electrostatic interaction between Na and O for suppressed Na+ /vacancy rearrangements. These collectively lead to a whole-voltage-range solid-solution reaction between 1.8 and 4.3 V with a small volume variation of 1.49%. This rewards its excellent cycling stability (capacity retention of 90% after 500 cycles) and rate capability (89 mAh g-1 at 2000 mA g-1 ).

Bimetal-Organic Framework Nanoboxes Enable Accelerated Redox Kinetics and Polysulfide Trapping for Lithium-Sulfur Batteries.

Lithium-sulfur (Li-S) batteries are considered as promising candidates for next-generation energy storage systems in view of the high theoretical energy density and low cost of sulfur resources. The suppression of polysulfide diffusion and promotion of redox kinetics are the main challenges for Li-S batteries. Herein, we design and prepare a novel type of ZnCo-based bimetallic metal-organic framework nanoboxes (ZnCo-MOF NBs) to serve as a functional sulfur host for Li-S batteries. The hollow architecture of ZnCo-MOF NBs can ensure fast charge transfer, improved sulfur utilization, and effective confinement of lithium polysulfides (LiPSs). The atomically dispersed Co-O4 sites in ZnCo-MOF NBs can firmly capture LiPSs and electrocatalytically accelerate their conversion kinetics. Benefiting from the multiple structural advantages, the ZnCo-MOF/S cathode shows high reversible capacity, impressive rate capability, and prolonged cycling performance for 300 cycles.

Reversible Metal and Ligand Redox Chemistry in Two-Dimensional Iron-Organic Framework for Sustainable Lithium-Ion Batteries.

Metal-organic frameworks (MOFs) are emerging as attractive electrode materials for lithium-ion batteries, owing to their fascinating features of sustainable resources, tunable chemical components, flexible molecular skeletons, and renewability. However, they are faced with a limited number of redox-active sites and unstable molecular frameworks during electrochemical processes. Herein, we design a novel two-dimensional (2D) iron(III)-tetraamino-benzoquinone (Fe-TABQ) with dual redox centers of Fe cations and TABQ ligands for high-capacity and stable lithium storage. It is constructed of square-planar Fe-N2O2 linkages and phenylenediamine building blocks, between which the Fe-TABQ chains are connected by multiple hydrogen bonds, and then featured as an extended π-d-conjugated 2D structure. The redox chemistry of both Fe3+ cations and TABQ anions is revealed to render its remarkable specific capacity of 251.1 mAh g-1. Benefiting from the intrinsic robust Fe-N(O) bonds and reinforced Li-N(O) bonds during cycling, Fe-TABQ delivers high capacity retentions over 95% after 200 cycles at various current densities. This work will enlighten more investigations for the molecular designs of advanced MOF-based electrode materials.

Robust nitrogen removal from municipal wastewater by partial nitrification anammox at ultra-low dissolved oxygen in a pure biofilm system.

Efficient nitrogen removal from municipal wastewater applying a pure biofilm system has promise. In this study, a partial nitrification anammox (PNA) pure biofilm system was established in a sequencing batch reactor with anaerobic/oxic/anoxic operation; using this reactor, robust nitrogen removal from municipal wastewater at ambient temperature was achieved with a nitrogen removal efficiency (NRE) of 93.3 %. Partial nitrification with anammox could be coupled at dominant nitrite-oxidizing bacteria (NOB) abundance by controlling ultra-low dissolved oxygen (<0.1 mg/L) in the aerobic section where the contribution to nitrogen removal was 79.4 %. Microorganisms with different oxygen affinity spatially distributed on the carrier. Ammonia-oxidizing bacteria (AOB) dominated on the surface of the carrier, while anammox bacteria dominated on the interior of the carrier, with their relative abundance increasing from 0.26 % to 1.78 %. The intercalary NOB were inhibited by the restricted oxygen transfer. Overall, this study provides a new approach to realize PNA in biofilm system.

Atomic Ruthenium-Riveted Metal-Organic Framework with Tunable d-Band Modulates Oxygen Redox for Lithium-Oxygen Batteries.

Non-aqueous Li-O2 batteries have aroused considerable attention because of their ultrahigh theoretical energy density, but they are severely hindered by slow cathode reaction kinetics and large overvoltages, which are closely associated with the discharge product of Li2O2. Herein, hexagonal conductive metal-organic framework nanowire arrays of nickel-hexaiminotriphenylene (Ni-HTP) with quadrilateral Ni-N4 units are synthesized to incorporate Ru atoms into its skeleton for NiRu-HTP. The atomically dispersed Ru-N4 sites manifest strong adsorption for the LiO2 intermediate owing to its tunable d-band center, leading to its high local concentration around NiRu-HTP. This favors the formation of film-like Li2O2 on NiRu-HTP with promoted electron transfer and ion diffusion across the cathode-electrolyte interface, facilitating its reversible decomposition during charge. These allow the Li-O2 battery with NiRu-HTP to deliver a remarkably reduced charge/discharge polarization of 0.76 V and excellent cyclability. This work will enrich the design philosophy of electrocatalysts for regulation of kinetic behaviors of oxygen redox.

Protective role for C3aR in experimental chronic pyelonephritis.

Emerging evidence suggest that C3aR plays important roles in homeostasis, host defense and disease. Although it is known that C3aR is protective in several models of acute bacterial infections, the role for C3aR in chronic infection is largely unknown. Here we show that C3aR is protective in experimental chronic pyelonephritis. Global C3aR deficient (C3ar-/- ) mice had higher renal bacterial load, more pronounced renal histological lesions, increased renal apoptotic cell accumulation, tissue inflammation and extracellular matrix deposition following renal infection with uropathogenic E. coli (UPEC) strain IH11128, compared to WT control mice. Myeloid C3aR deficient (Lyz2-C3ar-/- ) mice exhibited a similar disease phenotype to global C3ar-/- mice. Pharmacological treatment with a C3aR agonist reduced disease severity in experimental chronic pyelonephritis. Furthermore, macrophages of C3ar-/- mice exhibited impaired ability to phagocytose UPEC. Our data clearly demonstrate a protective role for C3aR against experimental chronic pyelonephritis, macrophage C3aR plays a major role in the protection, and C3aR is necessary for phagocytosis of UPEC by macrophages. Our observation that C3aR agonist curtailed the pathology suggests a therapeutic potential for activation of C3aR in chronic infection.

Histone deacetylase SirE regulates development, DNA damage response and aflatoxin production in Aspergillus flavus.

Aspergillus flavus is a ubiquitous saprotrophic soil-borne pathogenic fungus that causes crops contamination with the carcinogen aflatoxins. Although sirtuin E (SirE) is known to be a NAD-dependent histone deacetylase involved in global transcriptional regulation. Its biological functions in A. flavus are not fully understood. To explore the effects of SirE, we found that SirE was located in the nucleus and increased the level of H3K56 acetylation. The ΔsirE mutant had the most severe growth defect in the sirtuin family. The RNA-Seq revealed that sirE was crucial for secondary metabolism production as well as genetic information process and oxidation-reduction in A. flavus. Further analysis revealed that the ΔsirE mutant increased aflatoxin production. Both the sirE deletion and H3K56 mutants were highly sensitive to DNA damage and oxidative stresses, indicating that SirE was required for DNA damage and redox reaction by the H3K56 locus. Furthermore, the ΔsirE mutant displayed high sensitivity to osmotic stress and cell wall stress, but they may not be associated with the H3K56. Finally, the catalytic activity site N192 of SirE was required for regulating growth, deacetylase function and aflatoxin production. Together, SirE is essential for histone deacetylation and biological function in A. flavus.

Doxycycline vs Placebo at 12 Weeks in Patients With Mild Thyroid-Associated Ophthalmopathy: A Randomized Clinical Trial.

Importance: Mild thyroid-associated ophthalmopathy (TAO) negatively impacts quality of life, yet no clinical guidelines for its treatment are available. Existing evidence supports the use of doxycycline in treating mild TAO. Objective: To evaluate the short-term (12 weeks) efficacy of doxycycline in treating mild TAO. Design, Setting, and Participants: In this placebo-controlled multicenter randomized double-masked trial, 148 patients were assessed for eligibility. After exclusions (patients who were pregnant or lactating, had an allergy to tetracyclines, or had uncontrolled systematic diseases), 100 patients with mild TAO (orbital soft tissue affected mildly) at 5 centers in China were enrolled from July 2013 to December 2019 and monitored for 12 weeks. Interventions: Participants were randomly assigned 1:1 to receive doxycycline (50 mg) or placebo once daily for 12 weeks. Main Outcomes and Measures: The primary outcome was the rate of improvement at 12 weeks compared with baseline assessed by a composite indicator of eyelid aperture (reduction ≥2 mm), proptosis (reduction ≥2 mm), ocular motility (increase ≥8°), and Graves ophthalmopathy-specific quality-of-life (GO-QOL) scale score (increase ≥6 points). Adverse events were recorded. Results: A total of 50 participants were assigned to doxycycline and 50 to placebo. The mean (SD) age was 36.7 (9.1) years; 75 participants (75.0%) were female and 100 (100.0%) were Asian. Medication compliance was checked during participant interviews and by counting excess tablets. At week 12, the improvement rate was 38.0% (19 of 50) in the doxycycline group and 16.0% (8 of 50) in the placebo group (difference, 22.0%; 95% CI, 5.0-39.0; P = .01) in the intention-to-treat population. The per-protocol sensitivity analysis showed similar results (39.6% [19 of 48] vs 16.0% [8 of 50]; difference, 23.6%; 95% CI, 6.4-40.8; P = .009). No adverse events other than 1 case of mild gastric acid regurgitation was recorded in either group. Conclusions and Relevance: The results of this study indicate that oral doxycycline, 50 mg daily, resulted in greater improvement of TAO-related symptoms at 12 weeks compared with placebo in patients with mild TAO. These findings support the consideration of doxycycline for mild TAO but should be tempered by recognizing the relatively short follow-up and the size of the cohort. Trial Registration: ClinicalTrials.gov Identifier: NCT02203682.

The atmospheric microplastics deposition contributes to microplastic pollution in urban waters.

Identifying and understanding the potential sources delivering microplastics into the urban water environment is imperative for microplastic pollution control. However, how atmospheric deposition contributes to microplastic pollution in the urban water environment is unclear. Therefore, this study investigated the contribution of atmospheric deposition to microplastic pollution in urban waters based on the analysis of the atmospheric deposition characteristics in the urban area. The results showed that microplastic deposition fluxes during wet weather and dry weather varied from 1.1 × 103±0.06×103 to 3.5 × 103±0.3 × 103 particles/m2/day and 0.91×103±0.09×103 to 1.6 × 103±0.1 × 103 particles/m2/day, respectively. The microplastics deposition flux showed moderate to strong correlations to atmospheric particulate matter concentrations, especially the PM2.5 concentration (R2 = 0.76-0.93), suggesting the regularly monitored PM2.5 concentration might be served as an indicator for microplastics deposition flux estimation. The deposited microplastics were mainly transparent fragments with an average size of 51-67 µm. Polyethylene and polypropylene were the most abundant plastic polymer, followed by polyethylene terephthalate and polyamide. The comparison of microplastics collected during different weather conditions suggested that rain events could increase microplastics deposition fluxes when air quality conditions are similar. Particularly, rains promoted the deposition of fibrous microplastics as well as smaller microplastics. The estimated daily microplastics deposition in the whole city region suggested more microplastics were deposited in summer and winter. The total quantity of microplastics deposited in the urban environment could reach 1.7-12 times of those discharged from treated wastewater. Among them, 10% would directly deposit to urban waters in the studied city region, while the others may also enter the urban waters through runoff. The results of this study highlighted that the atmospheric microplastics deposition is an important source for microplastics, especially smaller ones, to enter the urban waters, which could not be ignored during microplastics pollution control.

Quenching singlet oxygen via intersystem crossing for a stable Li-O2 battery.

Aprotic Li-O2 batteries are a promising energy storage technology, however severe side reactions during cycles lead to their poor rechargeability. Herein, highly reactive singlet oxygen (1O2) is revealed to generate in both the discharging and charging processes and is deterimental to battery stability. Electron-rich triphenylamine (TPA) is demonstrated as an effective quencher in the electrolyte to mitigate 1O2 and its associated parasitic reactions, which has the tertiary amine and phenyl groups to manifest excellent electrochemical stability and chemical reversibility. It reacts with electrophilic 1O2 to form a singlet complex during cycles, and it then quickly transforms to a triplet complex through nonradiative intersystem crossing (ISC). This efficiently accelerates the conversion of 1O2 to the ground-state triplet oxygen to eliminate its derived side reactions, and the regeneration of TPA. These enable the Li-O2 battery with obviously reduced overvoltages and prolonged lifetime for over 310 cycles when coupled with a RuO2 catalyst. This work highlights the ISC mechanism to quench 1O2 in Li-O2 battery.

Rapidly recovering and maintaining simultaneous partial nitrification, denitrification and anammox process through hydroxylamine addition to advance nitrogen removal from domestic sewage.

The collapse of simultaneous partial nitrification, denitrification and anammox (SPNDA) system, caused by the destruction of partial nitrification (PN), is the most likely phenomenon to occur. Therefore, recovering the process quickly and maintaining efficient nitrogen removal is a valuable topic for research. In the anaerobic/aerobic/anoxic operation mode, SPNDA process was used to treat domestic sewage in a sequencing batch biofilm reactor. After the deterioration of PN effect, with the addition of hydroxylamine, the activity of ammonia-oxidizing bacteria in the nitrobacteria increased (61.0-91.3 %), whereas the accumulation of nitrite quickly recovered to 90.4 % within 5 days. Meanwhile, the nitrogen removal efficiency improved (61.8-95.6 %) and the effluent TN was 2.1 mg/L. Furthermore, Candidatus Brocadia was enriched (0.50-1.82 %) in the system. The results indicated that the addition of hydroxylamine was an effective strategy to recover and economically maintain the SPNDA process for advanced nitrogen removal from domestic sewage.