Inactivation of common airborne antigens by perfluoroalkyl chemicals modulates early life allergic asthma.

Allergic asthma, driven by T helper 2 cell-mediated immune responses to common environmental antigens, remains the most common respiratory disease in children. Perfluorinated chemicals (PFCs) are environmental contaminants of great concern, because of their wide application, persistence in the environment, and bioaccumulation. PFCs associate with immunological disorders including asthma and attenuate immune responses to vaccines. The influence of PFCs on the immunological response to allergens during childhood is unknown. We report here that a major PFC, perfluorooctane sulfonate (PFOS), inactivates house dust mite (HDM) to dampen 5-wk-old, early weaned mice from developing HDM-induced allergic asthma. PFOS further attenuates the asthma protective effect of the microbial product lipopolysaccharide (LPS). We demonstrate that PFOS prevents desensitization of lung epithelia by LPS, thus abolishing the latter's protective effect. A close mechanistic study reveals that PFOS specifically binds the major HDM allergen Der p1 with high affinity as well as the lipid A moiety of LPS, leading to the inactivation of both antigens. Moreover, PFOS at physiological human (nanomolar) concentrations inactivates Der p1 from HDM and LPS in vitro, although higher doses did not cause further inactivation because of possible formation of PFOS aggregates. This PFOS-induced neutralization of LPS has been further validated in primary human cell models and extended to an in vivo bacterial infection mouse model. This study demonstrates that early life exposure of mice to a PFC blunts airway antigen bioactivity to modulate pulmonary inflammatory responses, which may adversely affect early pulmonary health.

Toxicity effects of disinfection byproduct chloroacetic acid to Microcystis aeruginosa: Cytotoxicity and mechanisms.

Chlorine-based disinfectants are widely used for disinfection in wastewater treatment. The mechanism of the effects of chlorinated disinfection by-products on cyanobacteria was unclear. Herein, the physiological effects of chloroacetic acid (CAA) on Microcystis aeruginosa (M. aeruginosa), including acute toxicity, oxidative stress, apoptosis, production of microcystin-LR (MC-LR), and the microcystin transportation-related gene mcyH transcript abundance have been investigated. CAA exposure resulted in a significant change in the cell ultrastructure, including thylakoid damage, disappearance of nucleoid, production of gas vacuoles, increase in starch granule, accumulation of lipid droplets, and disruption of cytoplasm membranes. Meanwhile, the apoptosis rate of M. aeruginosa increased with CAA concentration. The production of MC-LR was affected by CAA, and the transcript abundance of mcyH decreased. Our results suggested that CAA poses acute toxicity to M. aeruginosa, and it could cause oxidative damage, stimulate MC-LR production, and damage cell ultrastructure. This study may provide information about the minimum concentration of CAA in the water environment, which is safe for aquatic organisms, especially during the global coronavirus disease 2019 pandemic period.

Mechanism of enhanced production of triterpenoids in algal-fungal consortium.

Chlorella pyrenoidosa-Ganoderma lucidum symbiotic systems were constructed. The mechanism of enhanced production of triterpenoids in algal-fungal consortium by comparing the contents of triterpenoids in individual fungal systems and algal-fungal consortium systems was investigated. The production of triterpenoids in C. pyrenoidosa-G. lucidum consortium increased significantly (P < 0.05). The categories and relative abundances of metabolites in the individual systems and algal-fungal systems were measured and analyzed by metabonomic tests. There were 57 significant different metabolites (VIP > 1 and P < 0.05) including 12 downregulated metabolites and 45 upregulated metabolites were obtained. The significant enriched metabolic pathways (VIP > 1 and P < 0.05) of citrate cycle (TCA cycle), tyrosine metabolism, glycolysis, and terpenoid backbone biosynthesis in algal-fungal consortium were obtained. The relative abundances of important precursors of triterpenoids including mevalonic acid, lanosterol, and hydroquinone were 1.4 times, 1.7 times, and 2 times, respectively, in algal-fungal consortium than that in the individual fungal systems. The presence of C. pyrenoidosa in algal-fungal consortium promoted the biosynthesis of triterpenoids in G. lucidum.

Cell cycle arrest mediated by Cd-induced DNA damage in Arabidopsis root tips.

Accumulating evidence demonstrates that the aberrant expression of cell cycle regulation and DNA repair genes can result in abnormal cell proliferation and genomic instability in eukaryotic cells under different stresses. Herein, Arabidopsis thaliana (Arabidopsis) seedlings were grown hydroponically on 0.5 × MS media containing cadmium (Cd) at 0-2.5mgL-1 for 5d of treatment. Real time quantitative reverse transcription-polymerase chain reaction (qRT-PCR) analysis revealed that expression of DNA damage repair and cell cycle regulation genes, including BRCA1, MRE11, WEE1, CDKA;1 and PCNA1, showed an inverted U-shaped dose-response. In contrast, notably reduced expression was observed for G1-to-S transition-related genes, Histone H4, E2Fa and PCNA2; DSB end processing, GR1; G2-to-M transition-related gene, CYCB1;1; and DNA mismatch repair, MSH2, MSH6 and MLH1 genes in root tips exposed to 0.125-2.5mg/L Cd for 5d. Flow cytometry (FCM) analysis revealed significant increases of cells with a 2C nuclear content and with a 4C and 8C nuclear content under Cd stresses of 0.125 and 1-2.5mgL-1, respectively. Our results suggest that 0.125mgL-1 Cd-induced DNA damage induced the marked G1/S arrest, leading to accelerated growth in root tips, while 1.0-2.5mgL-1 Cd-induced DNA damage caused a notable G2/M arrest in root tips, leading to reduced growth in root tips. This may be a protective mechanism that prevents cells with damaged DNA from dividing under Cd stress.

Mono- to Octachlorinated Polychlorinated Dibenzo-p-dioxin and Dibenzofuran Emissions from Sintering Plants Synergistically Controlled by the Desulfurization Process.

The influence of desulfurization systems in sintering plants on polychlorinated dibenzo-p-dioxin and dibenzofuran (PCDD/F) concentrations, profiles, and emission factors was studied. Mono- to tri-CDD/Fs and tetra- to octa-CDD/F concentrations were 4.4 ± 2.3 and 10.5 ± 8.3 ng m(-3), respectively, at the inlets and 0.87 ± 0.48 and 0.47 ± 0.22 ng m(-3), respectively, after desulfurization. The toxic equivalents (TEQs) were 0.95 ± 0.093 and 0.51 ± 0.040 ng of I-TEQ m(-3) at the inlets and after desulfurization, respectively. The congener profiles and homologue distributions were dominated by 2-MoCDF and MoCDF, respectively. The PCDD/F removal efficiencies achieved by desulfurization increased as the chlorination level increased. The PCDD/Fs became adsorbed to gypsum. Annual mono- to tri-CDD/Fs PCDD/F and TEQ (tetra- to octa-CDD/F) emission factors for flue gas and gypsum between 2003 and 2012 were determined. The total amounts of mono- to tri-CDD/Fs emitted in flue gas and gypsum between 2003 and 2012 were 10.7 and 10.2 kg, respectively. The total TEQs emitted in flue gas and gypsum between 2003 and 2012 were estimated to be 15486 and 1878 g of I-TEQ, respectively. PCDD/Fs adsorbed to gypsum are not effectively eliminated. The PCDD/F concentrations increased as the fly ash surface area increased moving through the electrostatic precipitator stages.

Insight into coagulation/flocculation mechanisms on microalgae harvesting by ferric chloride and polyacrylamide in different growth phases.

FeCl3 and polyacrylamide (PAM) had been used to investigate the effect of coagulation, flocculation, and their combination on algae cells and extracellular organic matter (EOM) at different phases. PAM tended to aggregate particle-like substances, while FeCl3 could interact with EOM. The content of EOM kept rising during the algae growth cycle, while OD680 peaked at about 3.0. At stationary phase Ⅰ, the removal efficiencies of UV254, turbidity and OD680 of the suspension conditioned with FeCl3 + PAM reached (88.08 ± 0.89)%, (89.72 ± 0.36)% and (93.99 ± 0.05)%, respectively. Nevertheless, PAM + FeCl3 exhibited the worst efficiency because of the release of EOM caused by the turbulence. The results suggested that algal cells served as a coagulation aid to facilitate floc formation, while excessive EOM deteriorated harvesting performance. The process of FeCl3 + PAM at stationary phase Ⅰ appears to be a promising technology for microalgae harvesting.

Changes in physiology, antioxidant system, and gene expression in Microcystis aeruginosa under fenoxaprop-p-ethyl stress.

Fenoxaprop-p-ethyl (FE) is one of the typical aryloxyphenoxypropionate herbicides. FE has been widely applied in agriculture in recent years. Human health and aquatic ecosystems are threatened by the cyanobacteria blooms caused by Microcystis aeruginosa, which is one of the most common cyanobacteria responsible for freshwater blooming. Few studies have been reported on the physiological effects of FE on M. aeruginosa. This study analyzed the growth curves, the contents of chlorophyll a and protein, the oxidative stress, and the microcystin-LR (MC-LR) levels of M. aeruginosa exposed to various FE concentrations (i.e., 0, 0.5, 1, 2, and 5 mg/L). FE was observed to stimulate the cell density, chlorophyll a content, and protein content of M. aeruginosa at 0.5- and 1-mg/L FE concentrations but inhibit them at 2 and 5 mg/L FE concentrations. The superoxide dismutase and catalase activities were enhanced and the malondialdehyde concentration was increased by FE. The intracellular (intra-) and extracellular (extra-) MC-LR contents were also affected by FE. The expression levels of photosynthesis-related genes psbD1, psaB, and rbcL varied in response to FE exposure. Moreover, the expressions of microcystin synthase-related genes mcyA and mcyD and microcystin transportation-related gene mcyH were significantly inhibited by the treatment with 2 and 5 mg/L FE concentrations. These results might be helpful in evaluating the ecotoxicity of FE and guiding the rational application of herbicides in modern agriculture.

Adsorption of 2-mercaptobenzothiazole from aqueous solution by organo-bentonite.

The adsorption behavior of 2-mercaptobenzothiazole onto organo-bentonite was investigated. Natural bentonite from Gaozhou in Guangdong Province, China was collected. Organo-bentonite was prepared by intercalation of cetyltrimethyl ammonium bromide into the natural bentonite. The physicochemical properties of the prepared organo-bentonite were characterized by X-ray diffraction, N2 adsorption-desorption isotherm and Fourier transform infrared spectroscopy. The results showed that montmorillonite is the main component of the natural bentonite. The basal spacing of the natural bentonite is 1.47 nm, which increased to 1.98 nm on intercalation with cetyltrimethyl ammonium bromide. Moreover, both the surface area and pore volume increased with intercalation. Clear CH2 stretching (3000-2800 cm(-1)) and scissoring (1480-1450 cm(-1)) modes of the intercalated surfactants were observed for organo-bentonite. Compared with the pseudo first-order kinetic model, the pseudo second-order kinetic model is more suitable to describe the adsorption kinetics of 2-mercaptobenzothiazole onto organo-bentonite. The adsorption capacity of 2-mercaptobenzothiazole onto organo-bentonite increased with increasing initial concentration of 2-mercaptobenzothiazole, but decreased with increasing adsorbent dosage. The adsorption isotherm of 2-mercaptobenzothiazole onto organo-bentonite fits well with the Langmuir model. The maximum adsorption capacity of organo-bentonite for 2-mercaptobenzothiazole was 33.61 mg/g, indicating that organo-bentonite is a promising adsorbent for 2-mercaptobenzothiazole.

New insights into the distribution, potential source and risk of microplastics in Qinghai-Tibet Plateau.

Microplastics (MPs) as emerging contaminants have become a major global concern, however, the distribution and origin of MPs in Qinghai-Tibet Plateau (QTP) and their impacts on ecosystem are poorly known. Hence, we systematically evaluated the profile of MPs on the representative metropolitan locations of Lhasa and Huangshui Rivers and the scenic sites of Namco and Qinghai Lake. The average abundance of MPs in the water samples was 7020 items/m3, which was 34 and 52 times higher than those for the sediment (206.7 items/m3) and soil samples (134.7 items/m3), respectively. Huangshui River had the highest levels, followed by Qinghai Lake, Lhasa River and Namco. Human activities rather than altitude and salinity impacted the distribution of MPs in those areas. Besides the consumption of plastic products by locals and tourists, laundry wastewater and exogenous tributary inputs, the unique prayer flag culture also contributed to the MPs emission in QTP. Notably, the stability and fragment of MPs were crucial for their fate. Multiple assessment models were employed to evaluate the risk of MPs. PERI model took MP concentration, background value and toxicity into account, comprehensively describing the risk differences of each site. The large PVC proportion in Qinghai Lake posed the highest risk. Furthermore, concerns should be raised about PVC, PE and PET in Lhasa and Huangshui Rivers, and PC in Namco Lake. Risk quotient suggested that aged MPs in sediments slowly released biotoxic DEHP and should be cleaned up promptly. The findings offer baseline data of MPs in QTP and ecological risks, providing important support for the prioritization of future control measures.

Removal mechanism of Microcystis aeruginosa in Fe2+/sodium percarbonate and Fe2+/sodium persulfate advanced oxidation-flocculation system.

Advanced oxidation process (AOPs) can be used for the treatment of harmful algal blooms (HABs). In this study, two systems of Fe2+/sodium percarbonate (Fe2+/SPC system) and Fe2+/sodium persulfate (Fe2+/PS system) were established to explore the removal mechanism of Microcystis aeruginosa (M. aeruginosa). The results indicated that the Fe2+/SPC system catalyzed H2O2 to generate a large amount of [Formula: see text] for oxidation by Fe2+ and formed Fe3+ to promote the flocculation of M. aeruginosa. The persulfate was activated by Fe2+ to generate [Formula: see text] with super-oxidizing properties, and Fe3+ was generated to realize the oxidation and flocculation of M. aeruginosa in the Fe2+/PS system. Compared with the traditional method in which the pre-oxidation and flocculation processes are carried out separately, the method in this study effectively improves the utilization rate of the flocculant and the removal effect of M. aeruginosa. The absolute value of zeta potential of Fe2+/PS system (|ζ|= 0.808 mV) was significantly lower than that of Fe2+/SPC system (|ζ|= 21.4 mV) (P < 0.05), which indicated that Fe2+/PS system was more favorable for the flocculation of M. aeruginosa cells than the Fe2+/SPC system.

Research progress of advanced oxidation technology for the removal of Microcystis aeruginosa: a review.

In recent years, cyanobacteria blooms have continued to erupt frequently, seriously jeopardizing the safety of drinking water and human health. The safe, quick, and economical removal of cyanobacteria from water bodies, especially the dominant species of cyanobacteria, Microcystis aeruginosa, has captured a lot of scientists' attention. The application of advanced oxidation technology in water treatment is very promising, but it has not yet been used in production. To further promote the application of the advanced oxidation method in water treatment, this article combines the results of advanced research in China and abroad to review this emergent technology. Briefly, advanced oxidation process methods employ various mechanisms to remove the dominant species of cyanobacteria blooms Microcystis aeruginosa. This provides a theoretical reference and support for the efficient removal of harmful cyanobacteria from water.

Algal-bacterial consortium mediated system offers effective removal of nitrogen nutrients and antibiotic resistance genes.

The sulfonamide antibiotic resistance genes (ARGs) especially sul1 was identified as the dominant in eutrophic water. The performance of Chlorella vulgaris-B. licheniformis consortium toward sul1 removal, total nitrogen (TN) removal, and the mechanism of sul1 removal was investigated. The removal efficiency of exogenous ARGs plasmids carrying sul1 reached (97.2 ± 2.3)%. The TN removal rate reached (98.5 ± 1.2)%. The enhancements of carbon metabolism, nitrogen metabolism, aminoacyl-tRNA biosynthesis, and glycoproteins had significant influences on sul1 and TN removals, under the premise of normal growth of algae and bacteria. The quantitative polymerase chain reaction (qPCR) results suggested that the absolute abundances of sul1 were low in algal-bacterial systems (0 gene copies/mL) compared with individual systems ((1 × 106 ± 15) gene copies/mL). The duplication of sul1 was inhibited in algal cells and bacterial cells. The algal-bacterial consortium seems to be a promising technology for wastewater treatment with a potential to overcome the eutrophication and ARGs challenges.

Mutual impacts and interactions of antibiotic resistance genes, microcystin synthetase genes, graphene oxide, and Microcystis aeruginosa in synthetic wastewater.

The physiological impacts and interactions of antibiotic resistance gene (ARG) abundance, microcystin synthetase gene expression, graphene oxide (GO), and Microcystis aeruginosa in synthetic wastewater were investigated. The results demonstrated that the absolute abundance of sul1, sul2, tetW, and tetM in synthetic wastewater dramatically increased to 365.2%, 427.1%, 375.2%, and 231.7%, respectively, when the GO concentration was 0.01 mg/L. Even more interesting is that the sum gene copy numbers of mcyA-J also increased to 243.2%. The appearance of GO made the significant correlation exist between ARGs abundance and mcyA-J expression. Furthermore, M. aeruginosa displayed better photosynthetic performance and more MCs production at 0.01 mg/L GO. There were 65 pairs of positive correlations between the intracellular differential metabolites of M. aeruginosa and the abundance of sul1, sul2, tetM, and tetW with various GO concentrations. The GO will impact the metabolites and metabolic pathway in M. aeruginosa. The metabolic changes impacted the ARGs, microcystin synthetase genes, and physiological characters in algal cells. Furthermore, there were complex correlations among sul1, sul2, tetM, tetW, mcyA-J, MCs, photosynthetic performance parameters, and ROS. The different concentration of GO will aggravate the hazards of M. aeruginosa by promoting the expression of mcyA-J, producing more MCs; simultaneously, it may cause the spread of ARGs.

The effect of carbon-based copper nanocomposites on Microcystis aeruginosa and the movability of antibiotic resistance genes in urban water.

The presence of Microcystis aeruginosa (M. aeruginosa) can affect the transference of antibiotic resistance genes (ARGs), and the presence of carbon-based copper nanocomposites (CCN) can affect the growth of M. aeruginosa. However, the effect of CCN on M. aeruginosa and ARGs is not fully understood. In this study, metagenomic sequencing was employed to analyze the movability of ARGs, their potential transfer, and possible hosts in photobioreactor treating urban water. The results uggested that 20 mg/L of CCN changed the composition and abundance of microorganisms in urban water, significantly promoted the flocculation of M aeruginosa, and decreased the composing proportion of Cyanophyta sp. and M aeruginosa. The results indicated that 20 mg/L of CCN significantly decreased the absolute abundance and ARGs proportions which mediated by plasmids (32.7 %). Furthermore, the lower co-occurrence probability of ARGs and mobile genetic elements (MGEs) suggested that 20 mg/L of CCN weakened the movability potential of ARGs mediated by MGEs such as plasmids. Among the 452 metagenome-assembled genomes (MAGs), 95 MAGs belonging to 41 bacterial categories were identified as possible ARG hosts. These results will provide insights into the control of harmful cyanobacteria and the management of ARGs in urban water.

Enantioselective effects of chiral fragrance carvone (L- and D-carvone) on the physiology, oxidative damage, synthesis, and release of microcystin-LR in Microcystis aeruginosa.

Carvone is a widely used chiral fragrance with two isomers (L-carvone and D-carvone). D-carvone smells like a caraway, whereas L-carvone smells like mint. Carvone imposes a potential burden on the aquatic ecosystem. However, the enantioselective toxic effect of carvone enantiomers on cyanobacteria remains unknown. This study aims to investigate the effects of L- and D-carvone on the physiological processes and related gene transcription (phoU, rbcL, and mcyH) in M. aeruginosa. Results showed that in the presence of L- and D-carvone, the oxidative damage and inhibitory effects on growth occurred in a concentration-dependent manner. The contents of chlorophyll a and protein and the rbcL transcription level were inhibited in M. aeruginosa. In addition, intracellular adenosine triphosphate (ATP) was heavily depleted because of various biological processes, including growth, oxidation reactions, and gene regulation. Meanwhile, L- and D-carvone stimulated the production and release of MC-LR and upregulated the expression level of the MC-LR-related gene mcyH. Intracellular MC-LR likely leaked to the water body under L-carvone exposure, posing a potential threat to the water environment. This study indicated that L- and D-carvone can regulate the physiological and metabolic activity of M. aeruginosa and show enantioselective toxic effects. The findings will also provide important insights into the influence of chiral fragrance on cyanobacterial blooms. Furthermore, this study will guide the safe application of chiral fragrance as personal care products.

Distinct clinico-biological features in AML patients with low allelic ratio FLT3-ITD: role of allogeneic stem cell transplantation in first remission.

The mutant burden of FLT3-ITD modulates its prognostic impact on patients with acute myeloid leukemia (AML). However, for patients with low allelic ratio (AR) FLT3-ITD (FLT3-ITDlow, AR < 0.5), clinical features, as well as genomic and transcriptomic profiles remain unclear, and evidence supporting allogeneic hematopoietic stem cell transplantation (allo-HSCT) in first complete remission (CR1) remains controversial. This study aimed to elucidate the genomic features, prognosis, and transplantation outcome of FLT3-ITDIow in AML patients with intermediate-risk cytogenetics. FLT3-ITDlow was associated with a negative enrichment of the leukemic stem cell signature, a marked enrichment of the RAS pathway, and with higher frequencies of RAS pathway mutations, different from those with FLT3-ITDhigh. Concurrent CEBPA double mutations were favorable prognostic factors, whereas MLL-PTD, and mutations in splicing factors were unfavorable prognostic factors in FLT3-ITDlow patients. Patients with FLT3-ITDlow had a shorter overall survival (OS) and event-free survival (EFS) than those with FLT3wt. Allo-HSCT in CR1 was associated with a significantly longer OS and EFS compared with postremission chemotherapy in patients with FLT3-ITDlow. In conclusion, FLT3-ITDlow is associated with different mutational and transcriptomic profiles compared with FLT3-ITDhigh. The presence of concomitant poor-risk mutations exert negative prognostic impacts in patients with FLT3-ITDlow, who markedly benefit from allo-HSCT in CR1.

Solvothermal synthesis of bismuth molybdate hollow microspheres with high photocatalytic activity.

Bi2MoO6 hollow microspheres were successfully synthesized by a simple solvothermal process without using any hard template or surfactant. The effect of solvent and urea on the morphology of the samples was studied systematically. The results indicate that the composition of the mix ethylene glycol/absolute ethanol solvents and the urea content play a key role in the final formation of hollow microspheres. Based on the experimental results, the formation mechanism of the hollow interior by an EG-induced Ostwald ripening process was proposed for the Bi2MoO6 hollow microspheres. The Bi2MoO6 hollow microspheres exhibit higher catalytic activity than the Bi2MoO6 particles for degradation of Rhodamine B under visible-light irradiation (lambda > 420 nm). Further investigation revealed that the surface area, grain size, and hollow structure of the as-prepared Bi2MoO6 microspheres are responsible for the improvement of the photocatalytic activity.

Clinical implications of sequential MRD monitoring by NGS at 2 time points after chemotherapy in patients with AML.

Next-generation sequencing (NGS) has been applied to measurable/minimal residual disease (MRD) monitoring after induction chemotherapy in patients with acute myeloid leukemia (AML), but the optimal time point for the test remains unclear. In this study, we aimed to investigate the clinical significance of NGS MRD at 2 different time points. We performed targeted NGS of 54 genes in bone marrow cells serially obtained at diagnosis, first complete remission (first time point), and after the first consolidation chemotherapy (second time point) from 335 de novo AML patients. Excluding DNMT3A, TET2, and ASXL1 mutations, which are commonly present in individuals with clonal hematopoiesis of indeterminate potential, MRD could be detected in 46.4% of patients at the first time point (MRD1st), and 28.9% at the second time point (MRD2nd). The patients with detectable NGS MRD at either time point had a significantly higher cumulative incidence of relapse and shorter relapse-free survival and overall survival. In multivariate analysis, MRD1st and MRD2nd were both independent poor prognostic factors. However, the patients with positive MRD1st but negative MRD2nd had a similar good prognosis as those with negative MRD at both time points. The incorporation of multiparameter flow cytometry and NGS MRD revealed that the presence of NGS MRD predicted poorer prognosis among the patients without detectable MRD by multiparameter flow cytometry at the second time point but not the first time point. In conclusion, the presence of NGS MRD, especially after the first consolidation therapy, can help predict the clinical outcome of AML patients.

Life stage-dependent toxicities of 1-ethyl-3-methylimidazolium bromide on Caenorhabditis elegans.

Ionic liquids (ILs) are considered as extracting solvents in soil remediation. However, they can be pollutants themselves, and their own toxicities are of concerns. Notably, organisms were exposed to pollutants at random life stages in actual environmental exposure scenario, which is different from the set-up of one uniform life stage in usual experiment designs. The influence of life stages on ILs toxicities will provide essential information on their actual environmental risks. In the present study, effects of 1-ethyl-3-methylimidazolium bromide ([C2mim]Br) were measured on C. elegans with egg exposure and adult exposure. In egg exposure, [C2mim]Br increased the lifespan, stimulated initial reproduction and inhibited the total reproduction. Biochemical indices including oxidative stress, antioxidant responses and oxidative damage were further measured to explore the toxicity mechanisms. Results showed that [C2mim]Br significantly stimulated O2-· as the oxidative stress and superoxide dismutase (SOD) as the antioxidant defense. In adult exposure, [C2mim]Br inhibited initial reproduction, total reproduction and lifespan. Biochemical results showed that [C2mim]Br significantly stimulated H2O2 and oxidized glutathione (GSSG). The overall findings demonstrated that [C2mim]Br caused life stage-dependent toxicities on C. elegans. Future studies are still needed for the detailed mechanisms.

Intensified nitrogen removal in constructed wetlands by novel spray aeration system and different influent COD/N ratios.

The degradation performance of organic matters and microorganism abundance variations of two horizontal subsurface flow constructed wetlands (HSSFCWs) with different influent COD/N ratios and a spray aeration system were investigated. Oxygen-enriched influent water was beneficial to enhance the abilities of nitrification and biodegradation of organic matters. Due to the sufficient carbon source supply under influent COD/N ratio of 8.0, the high removal performances of COD (93%), NH4-N (85%) and total nitrogen (78%) were simultaneously obtained in HSSFCWs with a spray aeration system. The increase in nitrite and nitrate bacteria was beneficial to complete nitrification and improve NH4-N removal. The increase in denitrifying bacteria contributed to complete denitrification and guaranteed the high removal efficiency of NO3-N. The results suggested that the spray aeration combined with high influent COD/N ratios could achieve the high nitrogen removal in HSSFCWs.