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The ligand-directed (LD) chemistry provides powerful tools for site-specific modification of proteins. We utilized a peptide with an appended methionine (Met) as a ligand; then, the Met thioether was modified into sulfonium which enabled a proximity induced group transfer onto protein cysteine in the vicinity upon peptide-target binding. The sulfonium warhead could be easily constructed with unprotected peptides, and the transferable group scope was conducted on model protein PDZ and its ligand peptides. In addition, a living cell labeling was successfully achieved.

Herein, we report the first facile Cu-free click reaction between alkynyl sulfonium and azide at ambient temperatures in aqueous media. DFT computations indicate that the sulfonium group is the key factor to gaining reactivity by stabilizing LUMO+1 and influencing the charge distribution of the triple bond. Sulfonium alkynes can be easily synthesized and scaled up, and most of them are biocompatible. We prepared candidate molecules and tested their use in multiple proof-of-concept biological applications.

A pilot-scale multistage constructed wetland-pond (MCWP) system with a "pre-ecological oxidation pond, two-stage horizontal subsurface flow constructed wetland (HSCW) and surface flow constructed wetland (SFCW) as the core and postsubmerged plant pond" as the process was used to treat actual polluted river water in the field, and the variation in nitrogen removal from summer to winter was investigated. The results showed that the average total nitrogen (TN) removal efficiency in the MCWP was approximately 40.74%. The significant positive correlation between the daily highest temperature and the TN removal efficiency of the whole system was fitted with a nonlinear curve (R2 = 0.7192). The TN removal load rate in the HSCWs was 2.7–3.7 times that in the SFCW. The SFCW, which had high-density plants (35 plants/m2), increased the proportion of nitrogen removed by plant harvesting and microbial function. The TN transformed by Iris pseudacorus L. accounted for 54.53% in the SFCW. Furthermore, bacteria completed the nitrogen cycle in the SFCW through a variety of nitrogen removal pathways. This research not only investigated the TN removal performance in an MCWP system but also made it possible to predict the TN removal efficiency according to the daily highest temperature from summer to winter in the field.

Functionalization of histidine residues in proteins via visible-light-promoted thioacetal activation is reported. ∼2000 proteins with reactive and exposed histidine residues from the MCF7 cell line are characterized using ABPP by this method.

A biomimetic method has been established for the chemo-selective desulfurization of cysteinyl peptides and proteins in aqueous media. The derivatives of biocatalytic cofactors, flavins, were found to be efficient photosensitizers in a thiyl-radical-mediated desulfurization of Cys. The reaction was conducted in an ultrafast manner with both polypeptides and proteins.

To observe the synergistic effect of garlic essential oil in patients with novel coronavirus disease (COVID-19), in addition to the routine treatment, we used garlic essential oil in COVID-19 patients with mild to moderate symptoms and compared their results to those of patients who did not receive the essential oil. We conducted a quasi-experimental study with COVID-19 patients from 3 hospitals. In the experimental group, 97 patients received garlic essential oil combined with conventional treatment. In the control group, 100 patients received only the conventional treatment for COVID-19. The effectiveness and safety of the garlic essential oil were assessed. Compared to the control group, the group receiving garlic essential oil showed a shorter duration of symptoms, shorter time to negative nucleic acid testing (NAT) results and shorter time to improvement on the computed tomography (CT). In the same period, the experimental group showed an increase in the rate of the disappearance of symptoms and the improvement rates of NAT and CT. Due to its effectiveness and safety in patients with COVID-19, garlic essential oil is recommended as a preventive measure or a supportive therapy during the COVID-19 pandemic.

Histidine (His, H) undergoes various post-translational modifications (PTMs) and plays multiple roles in protein interactions and enzyme catalyzed reactions. However, compared with other amino acids such as Lys or Cys, His modification is much less explored. Herein we describe a novel visible-light-driven thioacetal activation reaction which enables facile modification on histidine residues. An efficient addition to histidine imidazole N3 under biocompatible conditions was achieved with an electrophilic thionium intermediate. This method allows chemo-selective modification on peptides and proteins with good conversions and efficient histidine-proteome profiling with cell lysates. 78 histidine containing proteins were for the first time found with significant enrichment, most functioning in metal accumulation in brain related diseases. This facile His modification method greatly expands the chemo-selective toolbox for histidine-targeted protein conjugation and helps to reveal histidine's role in protein functions.

Graphical abstract, COVID-19 is the first global scale crisis since the inception of Bitcoin. We compare the contagion phenomenon of Bitcoin and other financial markets or assets pre and during the COVID-19 shock in both contemporaneous and non-contemporaneous manner. This paper uses the directed acyclic graph (DAG), spillover index, and network topology to provide strong evidence on the directional contagion outcomes of Bitcoin and other assets. The empirical results show that the contagion effect between Bitcoin and developed markets is strengthened during the COVID-19 crisis. Particularly, European market has a dominant role. Excluding Bitcoin’s own shocks, United State and European markets are the main contagion sources to Bitcoin. European market also works as a intermediary to deliver infectious from United State and market fear. The findings show that gold always has contagion effect with Bitcoin, while gold, US dollar and bond market are the contagion receivers of Bitcoin under the shock of COVID-19. The empirical results further proved the safe haven, hedge and diversifier potential of Bitcoin in economic stable time, but also shows that the sustainability of these properties is undermined during the market turmoil.

The pharmaceutical and personal care product (PPCP) residues in freshwater lakes are being highlighted around the world. The occurrence and ecological risk of 34 PPCPs classified as antibiotics, non-steroidal anti-inflammatory drugs (NSAID), cardiovascular drugs, psychotropic drugs, anti-inflammatory drugs, psychostimulants, and pesticides during rainstorm period in surface water of the Dongting Lake, China, were studied. Twenty-six out of thirty-four PPCPs were detected, and the total concentrations of antibiotics ranged from 0.15 to 214.75 ng L−1 in surface water. The highest average concentration was observed for diclofenac, followed by diethyltoluamide (DEET). The PPCP concentrations were much lower in Dongting Lake compared to other rivers and lakes due to the strong dilution effect of rainstorm, while the detection rate remains high. Caffeine and DEET were detected with 100% frequency in Dongting Lake, and the detection rates of diclofenac, mefenamic acid, and roxithromycin were above 90%. The pollution levels of antibiotics decreased in the order of East Dongting Lake > South Dongting Lake > West Dongting Lake, which may be related to the distribution of aquaculture plants, sewage treatment plants, and population density. The risk quotient (RQ) method was used to evaluate ecological environment risk under the worst case and the results suggested that clarithromycin, diclofenac, roxithromycin, and erythromycin might pose a significant risk to aquatic organisms in Dongting Lake, especially clarithromycin. This study can provide data support for further research on the dilutive effect and mechanism of rainwater runoff on PPCPs in lakes on a large scale.

Perfluorohexanoic acid (PFHxA), a widely used emerging alternative for 8-carbon PFAAs, has been detected at a high level in the water environment. While its toxicity and environmental health risk are still largely unknown in aquatic life. The present study aimed to evaluated the possible developmental neurotoxicity induced by PFHxA exposure (0, 0.48, 2.4, and 12 mg/L for 120 h) in the zebrafish embryo. Here, both developmental endpoints, neurotransmitters concentrations, locomotor behavior were analyzed. No significant effects on mortality, malformation rate, and growth delay were detected in the low dose treatment groups except for in the high dose group (12 mg/L). A significant increase in swimming speed were noted in the 0.48 mg/L group. Other changes including neurotransmitters concentrations and green fluorescent protein (GFP) expression in Tg (HuC-GFP) zebrafish larvae were significantly increased in 12 mg/L group. Beyond that, genes related to neurodevelopment were significantly decreased in larvae. Moreover, downregulations of protein expression levels of α1-tubulin, elavl3, and gap43 were identified. These results demonstrate that the PFAAs alternative PFHxA have no significant neurodevelopmental effects on zebrafish larvae under acute low-dose exposure, while, it is important to note that PFHxA perform inhibiting effects on neurotransmitter and central nervous system under a relatively high dose. This in vivo study could provide reliable toxicity information for risk assessments of PFHxA on aquatic ecosystems. Capsule PFHxA have no significant neurodevelopmental effects on zebrafish larvae under acute low-dose exposure, while exposed with relatively high-dose, could induced the alternations of neurotransmitter concentrations as well as the genes involved in the early developmental stages of zebrafish, leading to the impairment of the nervous system in zebrafish larvae.

Plant-microbe is a complementary coupling system for antibiotics removing in constructed wetlands (CWs), but how plant and rhizosphere microbiomes respond to antibiotics exposure and the occurrence of ARGs in this microenvironment have seldom been researched. Thus, the response of the plant-microbe coupling system to different levels of antibiotics (sulfamethoxazole (SMZ) and ofloxacin (OFL)) was investigated. The results showed that two antibiotic stressors have hormetic effects on plant growth, physiology, and microbial community evolution, and the antibiotic toxic effects presented as SMZ + OFL > SMZ > OFL. Antibiotic accumulation in the plants was in the order of roots > stems > leaves. Notably, the root attachments affected antibiotic transportation. The accumulation of antibiotics in the under-ground parts affected the rhizosphere microbial community structure, and the microorganisms were more sensitive to SMZ + OFL than the plants, with inflection points of 0.5 mg L−1 and 1 mg L−1, respectively. Pseudomonas was highly resistant to antibiotics, while Acidovorax and Devosia may play a role in antibiotic degradation. Correlation analysis and network analysis showed that antibiotic enrichment and the bacterial community contributed significantly to the abundance of antibiotic-resistant genes (ARGs), further revealing the co-occurrence of int1, ARGs, and the potential bacterial hosts.

To investigate the effect of a constructed wetland (CW) with steel slag as the filler on water contaminated by low phosphorus levels, a multistage pond CW system was designed in this study. Low-phosphorus polluted river water was used as the research object. This study explored the effects of using steel slag as a CW filler on phosphorus removal and the total phosphorus (TP) purification effect of the wetland system. The results showed that the TP removal rates in the ecological pond, oxidation pond, surface flow wetlands and submerged plant pond were 5.17%, 8.02%, 21.56%, and 16.31%, respectively. Intermittent increases in phosphorus concentration were observed in the reactors and were caused by the decay of plant tissues, which released pollutants. Because steel slag was added to the filler, the TP concentrations in the effluent of the first- and second-level horizontal subsurface CWs increased by 151.13% and 16.29%, respectively, compared to the influent concentration. The 20th to 40th days of the test run was a period of rapid phosphorus release of the system. The use of steel slag has a potential risk of phosphorus release when applied in CWs used to purify low-phosphorus contaminated water bodies.

The residues of organophosphorus pesticides (OPPs) have been widely detected in rivers, the gulf, and even groundwater and drinking water, which may pose a serious threat to aquatic ecosystems and human health. Compared to other treatments, constructed wetlands (CWs) have been demonstrated to be a cost-effective alternative risk mitigation strategy for non-point-source pesticide pollution. This review summarizes 32 studies related to the remediation of OPPs in 117 CWs during 2001–2017 worldwide. The performances, mechanisms and influencing factors in the studies are comprehensively and critically reviewed in this paper. Overall, the OPPs were efficiently removed with an efficiency up to 87.22 ± 16.61%. The removal efficiency, differences and related reasons among different types of CWs in developed and developing countries and the different types of OPPs in CWs are well-evaluated in detail. In addition, the main processes for OPPs removal in CWs involve phytoremediation (plant uptake, phytoaccumulation, phytovolatilization and phytodegradation), substrate adsorption or sedimentation, and biodegradation. Based on the quantitative analysis by mass balance, for water-soluble pesticides, the dominant removal process was via microbiological degradation. This result was in contrast to findings obtained with hydrophobic OPPs, for which the dominant processes were biodegradation and sorption by substrate. Therefore, the behavior of microbial transformation prevails. Additionally, the presence of plants can facilitate the elimination of OPPs in CWs, promoting the process by an average percentage of approximately 6.19 ± 9.46%. Statistical analysis shows that loading of inlet OPPs is the largest limiting factor and that the HRT and T are the most significant parameters that influence the efficiency of trapping OPPs in CWs. Simultaneously, we can also obtain suitable parameters for the design and operation of CWs. This review promotes further research on plant-microbe joint combined remediation and examines the different behaviors of water-soluble and hydrophobic OPPs in CWs.

The efficiency of nitrogen removal and its mechanism, aquatic organism distribution characteristics and regeneration capability of zeolite from an integrated vertical-flow constructed wetland (IVFCW) for low pollution water treatment were evaluated after steady and continuous operation for eight years. After running for eight years, better than average COD and NH4+-N removal were observed in the IVFCW. The NH4+-N removal rate in this system was controlled by ammoxidation and adsorption and ion exchange of zeolite. The low total nitrogen (TN) removal efficiency was due to NO3−-N accumulation and zeolite desorption. In addition, this phenomenon indicated that because of poor organic carbon sources, nitrification was stronger than denitrification, consistent with the distribution of the functional genes for nitrification and denitrification. The biological activity in this system was abundant, especially that of spirogyra and navicula. The saturated adsorption capacity of zeolite was as high as 1.35 mg g−1 with a desorption rate of 50%). However, the drained reoxygenation performance of was better due to zero energy consumption and regeneration in situ.

The antibiotics residues in freshwater lakes are being highlighted around the world because of high potential threat to environment and human health. Understanding the current state of antibiotics and potential sources in lakes are important. The potential sources of antibiotics (Sewage treatment plants (STPs)), livestock and poultry farms and fishponds in the East Dongting was studied. Compared with other surface water bodies, the concentration of antibiotic in the East Dongting Lake was at a moderate or low level. Ten of 12 antibiotics likely originated from veterinary applications in livestock and poultry farms, especially in swine farms, and concentrations at these sources (ND-1240.41 ng L−1) were 1–3 orders of magnitude higher than in the effluent of local sewage treatment plants and fishponds. Based on a principal component analysis with multiple linear regression (PCA-MLR) model, we estimated source contributions of 79.95% for livestock and poultry farms, 0.27% for STPs, and 19.79% for aquaculture source and livestock and poultry farms. Overall, the predominance of sulfonamides and livestock and poultry farms in the East Dongting Lake has been identified, which can provide important information for regulating their veterinary use and environmental management.

Perfluorododecanoic acid (PFDoA), an artificial perfluorochemical, has been widely distributed in different ambient media and has been reported to have the potential to cause developmental neurotoxicity. However, the specific mechanism is largely unknown. In the current study, zebrafish embryos were treated with 0, 0.24, 1.2, and 6 mg/L PFDoA for 120 h. Exposure to PFDoA causes serious decreases in hatching delay, body length, as well as decreased locomotor speed in zebrafish larvae. Additionally, the acetylcholine (ACh) content as well as acetylcholinesterase (AChE) activity were determined to be significantly downregulated in PFDoA treatment groups. The level of dopamine was upregulated significantly after treating with 1.2 and 6 mg/L of PFDoA. Gene expressions related to the nervous system development were also analyzed, with the exception of the gene mesencephalic astrocyte-derived neurotrophic factor (manf), which is upregulated in the 6 mg/L treatment group. All other genes were significantly downregulated in larvae in the PFDoA group in different degrees. In general, the results demonstrated that PFDoA exposure could result in the disruption of the cholinergic system, dopaminergic signaling, and the central nervous system.

Perfluorododecanoic acid (PFDoA), a kind of perfluorinated carboxylic acid (PFCA) with 12 carbon atoms, has an extensive industrial utilization and is widespread in both wildlife and the water environment, and was reported to have the potential to cause a disruption in the thyroid hormone system homeostasis. In this study, zebrafish embryos/larvae were exposed to different concentrations of PFDoA (0, 0.24, 1.2, 6 mg/L) for 96 h post-fertilization (hpf). PFDoA exposure caused obvious growth restriction connected with the reduced thyroid hormones (THs) contents in zebrafish larvae, strengthening the interference effect on the growth of fish larvae. The transcriptional level of genes within the hypothalamic-pituitary-thyroid (HPT) axis was analyzed. The gene expression levels of thyrotropin-releasing hormone (trh) and corticotrophin-releasing hormone (crh) were upregulated upon exposure to 6 mg/L of PFDoA, and iodothyronine deiodinases (dio2) was upregulated in the 1.2 mg/L PFDoA group. The transcription of thyroglobulin (tg) and thyroid receptor (trβ) were significantly downregulated upon exposure to 1.2 mg/L and 6 mg/L of PFDoA. PFDoA could also decrease the levels of sodium/iodide symporter (nis) and transthyretin (ttr) gene expression in a concentration-dependent manner after exposure. A significant decrease in thyroid-stimulating hormoneβ (tshβ), uridinediphosphate-glucuronosyltransferase (ugt1ab) and thyroid receptor (trα) gene expression were observed at 6 mg/L PFDoA exposure. Upregulation and downregulation of iodothyronine deiodinases (dio1) gene expression were observed upon the treatment of 1.2 mg/L and 6 mg/L PFDoA, respectively. All the data demonstrated that gene expression in the HPT axis altered after different PFDoA treatment and the potential mechanisms of the disruption of thyroid status could occur at several steps in the process of synthesis, regulation, and action of thyroid hormones.

Pollution of sulfamethoxazole (SMX) in rural domestic sewage are a great challenge for ecological security because of limited treatment. In this study, an electrolysis-integrated bio-rack constructed wetland system (EC-CW-P) without substrates was developed for enhancing SMX removal in rural domestic sewage. The dynamic performance and mechanism of SMX (1 mg L-1) removal, occurrence of antibiotic resistance genes (ARGs) and microbial community composition at 4 ~ 24℃ were assessed. Meanwhile, the simultaneous removal performance of phosphorus in EC-CW-P was also analyzed due to key role of substrate adsorption and iron flocculation. The results revealed that the removal efficiency of SMX could reach 97.13% at 4 ~ 24℃ in the EC-CW-P by the electrocatalysis and adsorption of a ferric iron coagulant and biodegradation. Moreover, efficient removal of 74.12%~99.52% total phosphorus (TP) was obtained through electrocoagulation because of the formation of ferric ions. The occurrence of SMX had no effect on TP removal because of the different removal pathway. It should be emphasized that the removal efficiency of SMX owing to high microbial and plant activity which may be due to the formation of iron film and micro current stimulation and TP owing to adsorption of iron mud remained high (>80%) when the electrode was gradually passivated. Overall, the performance of bio-rack CW system was intensified by electrolysis (iron electrode) with higher bacterial abundance and plant activity in the EC-CW-P. However, the high relative abundance of sul ARGs (from 2.15 × 10-1 to 2.41 × 101 copies 16S rRNA-1) in the influent of the EC-CW-P may pose a severe threat to ecosystem. These results provide a novel perspective for enhancing SMX and phosphorus removal by bio-rack constructed wetland system.

Microcystin-LR (MCLR) has been reported to cause developmental neurotoxicity in zebrafish, but there are few studies on the mechanisms of MCLR-induced transgenerational effects of developmental neurotoxicity. In this study, zebrafish were exposed to 0, 1, 5, and 25 μg/L MCLR for 60 days. The F1 zebrafish embryos from the above-mentioned parents were collected and incubated in clean water for 120 h for hatching. After examining the parental zebrafish and F1 embryos, MCLR was detected in the gonad of adults and F1 embryos, indicating MCLR could potentially be transferred from parents to offspring. The larvae also showed a serious hypoactivity. The contents of dopamine, dihydroxyphenylacetic acid (DOPAC), serotonin, gamma-aminobutyric acid (GABA) and acetylcholine (ACh) were further detected, but only the first three neurotransmitters showed significant reduction in the 5 and 25 μg/L MCLR parental exposure groups. In addition, the acetylcholinesterase (AChE) activity was remarkably decreased in MCLR parental exposure groups, while the expression levels of manf, bdnf, ache, htr1ab, htr1b, htr2a, htr1aa, htr5a, DAT, TH1 and TH2 genes coincided with the decreased content of neurotransmitters (dopamine, DOPAC and serotonin) and the activity of AChE. Neuronal development related genes, α1-tubulin, syn2a, mbp, gfap, elavl3, shha and gap43 were also measured, but gap43 was the gene only up-regulated. Our results demonstrated MCLR could be transferred to offspring, and subsequently induce developmental neurotoxicity in F1 zebrafish larvae by disturbing the neurotransmitter systems and neuronal development.

Poyang Lake is the largest freshwater lake in China and plays a significant role by supplying drinking water, enabling agriculture, and preventing floods. Random selection was implemented to obtain 36 samples of surface deposits to determine concentrations of Pb, Cd, Cu, Zn, Cr, and Ni across Poyang Lake. At all sampling locations, values of Ni and Cd were thought to be lower than the effect range low (ERL). Relatively, values of Cu, Pb, Cr, and Zn were classified as ERL-effect range median (ERM) in more than 30% of sampling locations. In general, the eastern areas of Poyang Lake near the inflow rivers, such as the Raohe, Xinjiang, and Fuhe rivers, had higher concentrations of heavy metals. These rivers are sources of substantial industrial wastewater, including a lot of heavy metals. In addition, higher toxicity of sediments was found in the eastern area of the lake by evaluating the sum of toxic units (ΣTU). Contributions of Pb and Cr to the sum of toxic units were higher than the other heavy metals. If the heavy metals were classified by contribution to toxic units in Poyang Lake in decreasing order, they would be listed as Cr, Ni, Cd, Zn, Cu, and Pb.

AI image tampering technology - DeepFakes has a huge impact on the authenticity of video information in the network, making “seeing is believing” no longer credible. Finding effective methods for detecting DeepFakes is very important. The existing detection methods mostly rely on artificially designed features. This paper first proposes an adaptive deep learning detection model - DFDM for DeepFakes. DFDM uses deep learning networks to adaptively extract features of forgery images, which is efficient when facing a large number of samples and avoid the limitations of traditional detection methods. DFDM refers to the structure of steganalysis and forensic networks and pays attention to the anomaly of pixel distribution in images. DFDM can identify the anomaly of image texture features better than the general classification network. DFDM abandons the residual processing in the steganographic detection network, and designs a custom convolution kernel suitable for identifying image texture features to improve the accuracy of model detection. In the model network structure, DFDM replaces the mean pooling layer in steganalysis networks with the max-pooling layer, maximally retaining the image texture features. The simulation results show that the detection accuracy of DFDM for full-face replacement reaches 0.99, and the detection accuracy for partial-face replacement reaches 0.98.

The potential risk to human health of antibiotics that pass through the food chain has become an important global issue, but there are few reports on the response of ginger (Zingiber officinale) to antibiotic pollution. In this study, we investigated the enrichment characteristics and biological response of ginger to sulfamethoxazole (SMZ) and ofloxacin (OFL) residues, which are common in the environment. Lower levels of SMZ, OFL and their combined duplex treatment (SMZ+OFL) promoted the growth of ginger, but the critical doses necessary to stimulate growth differed among treatments: 10 mg L−1 SMZ, 1 mg L−1 OFL and 1 mg L−1 (SMZ+OFL) had the strongest stimulating effects. At higher dosages, the root growth and light energy utilization efficiency of ginger were impaired, and (SMZ+OFL) had the strongest inhibitory effect. Treatments with lower levels of antibiotics had no significant effect on reactive oxygen species and antioxidant enzyme activities. However, when SMZ, OFL and SMZ+OFL concentrations exceeded 10 mg L−1, the contents of H2O2, O2− and MDA continued to increase, while the activities of SOD, POD, CAT first increased and then decreased, especially in SMZ+OFL. Ginger accumulated more SMZ and OFL in rhizomes and less in leaves, and accumulation increased significantly as antibiotic concentration increased. When SMZ concentration was 1 mg L−1, the SMZ concentrations in rhizomes, roots, and leaves were 0.23, 0.15, and 0.05 mg kg−1, respectively, and the residual SMZ in the rhizome was 2.3 times higher than the maximum residue limit. The abundance of the resistance genes sul1, sul2, qnrS, and intI1 increased with increasing antibiotic concentrations, and intI1 abundance was the highest. OFL induced higher levels of intI1 expression than did SMZ.

An investigation into the occurrence of volatile organic compounds (VOCs) in the surface water of Poyang Lake was conducted. The determination of 54 different kinds of VOCs was performed with a purge and trap-gas chromatography-mass spectrometry method at 28 sampling points. Twenty-two types of VOCs were detected; methylene chloride had the highest mean concentration of 708.19 ng L−1, followed by 1,2-dichloroethane and chloroform, with mean concentrations of 376.78 and 187.26 ng L−1, respectively. The distribution of VOCs in the areas of Poyang Lake from low to high was as follows: west and south < east and central; the highest ∑VOC concentration occurred at the sample site of Zhangsihe. The health risks of VOCs in Poyang Lake were also determined by calculating the cancer and non-cancer risk from the two exposure routes of ingestion and dermal adsorption. The results showed that VOCs have no carcinogenicity risk, while only methylene chloride has a certain carcinogenic risk to the human body.

The multidrug and toxic compound extrusion (MATE) transporters mediate the coupled exchange of organic substrates and monovalent cations have been recently implicated in various plant biological activities. In this work, we isolated a dominant mutant from an Arabidopsis activation-tagging mutant pool. This mutant exhibits pleiotropic phenotype including early flowering, dwarf and bushy architecture, minified lateral organs and early leaf senescence, and is therefore designated early leaf senescence 1-Dominaint (els1-D). Genotyping assays showed that els1-D is a gain-of-function mutant of a novel MATE transporter gene, ELS1, which encodes a close homolog of the previously reported ADP1, BCD1 and DTX50. Further investigations revealed that the overexpression of ELS1 reduces iron content in els1-D, and the accelerated senescence of the detached els1-D leaves can be recovered by exogenous iron supply. In addition, we also found that ELS1 is an iron responsive gene. Based on these findings, we proposed that ELS1 is related to leaf senescence and iron homeostasis in Arabidopsis.

This study aims to investigate the removal efficiency and mechanism of sulfamethoxazole (SMX) and fate of corresponding sul genes in an electrolysis-integrated tidal flow constructed wetland system (EC-TFCWs). Compared with the single-stage TFCWs, excellent SMX removal was obtained in EC-TFCWs (increased by nearly 20%) owing to synergistic effect of electrolysis-integrated microbial degradation and flocculation. However, SMX removal in EC-TFCWs can be affected by electrode materials with iron electrode higher removal (average removal efficiency = 81.86%) than that of graphite electrode (average removal efficiency = 77.83%). In addition, the removal efficiency of SMX increased from 65.52% to 84.23%, from 42.32% to 87.22% and from 66.33% to 91.9% with the increase of current intensity from 0.21 mA cm2 to 1.50 m A cm2, hydraulic retention time (HRT) from 6 h to 48 h and electrolytic time from 2 h to 8 h, respectively. This result indicated that the current intensity, electrolytic time and HRT played an important role in SMX removal. The absolute abundance of sul genes in zeolite and effluent in EC (iron)-TFCWs was lower than that of in TFCWs at long stress of SMX. However, iron sludge can become a reservoir of sul genes. A novel EC (iron)-persulfate-integrated TFCWs was developed to further improve the performance of EC (iron)-TFCWs (increased by nearly 10%), which achieved a better removal effect and lower abundance of sul genes than that of in EC (iron)-TFCWs, and SO4 − played a key important role.

The molecular mechanism of contaminant removal in different electrolysis -integrated constructed wetlands (CWs) was explored. Electrolysis (microbial fuel cells (MFC) and direct current (EC))-integrated CWs achieved high removal efficiencies for chemical oxygen demand (COD; 82.18% in MFC-CWs and 81.57% in EC-CWs), total nitrogen (TN; 75.08% in MFC-CWs and 69.19% in EC-CWs) and total phosphorus (TP; 92.56% in MFC-CWs and 92.86%), which was higher than that in CWs. Additionally, MFC-CWs had an average voltage of 384.56 ± 44.49 mV with the highest power density of 977 mW m−2. The pollutant removal performance of the MFC-CWs was better than that of the EC-CWs. Microorganisms in electrolysis-integrated CWs, especially in the MFC-CWs, gained higher diversity and richness than those in CWS. However, the effects between MFC and EC for CWs were different. In addition, nitrogen functional genes in electrolysis-integrated CWs were significantly more abundant than those in the CWs, and the electron transfer rate also increased. Combined analyses of microorganisms and functional genes revealed that the main contributors to nitrogen removal were anaerobic ammoxidation, ammonia oxidation, denitrification, and dissimilatory nitrate reduction to ammonium (DNRA) for CWs, anaerobic ammoxidation, ammonia oxidation, denitrification and DNRA for EC-CWs, anaerobic ammoxidation, ammonia oxidation and denitrification for MFC-CWs

Chiral quinolone antibiotics, as racemate and in enantiomerically form, have been attracted extensive attention due to their same molecular structure and different pharmacological properties and toxicity in environment. The present study focused on the difference of degradation efficiency and pathway of chiral antibiotics by different AOPs technology. The degradation behaviors and differences of chiral pollutants were firstly identified. Among them, UV/PS process exhibited the best performance for the elimination of chiral pollutants removal and reduction of total organic carbon (TOC). The degradation of ofloxacin and levofloxacin revealed pronounced pH dependence in UV/H2O2 and UV/PS processes, where the impact on Levofloxacin (LEV) was greater than that on Ofloxacin (OFLO). Only a slight variation of TOC was observed to be less than 50%, where the removal efficiencies were all above 96%. SO4•− generated in UV/PS process yields a greater mineralization of antibiotics than •OH in UV/H2O2 process. Cl−, NO3− and NOM had inhibitory effects on OFLO and LEV degradation in both processes, while SO42− showed positive effect on UV/PS degradation. Meanwhile, chairal antibiotics removal was dominated by •OH with the second-order rate constants of 3.97 × 109 and 2.48 × 109 M−1s−1 in UV/H2O2 process, while SO4•− played the key role in UV/PS system with second-order rate constants of 2.19 × 1010 and 2.66 × 1010 M−1s−1, respectively. The results of acute toxicity assay shown that OFLO exhibited higher acute toxicity than LEV, while TTC dehydrogenase activity of intermediate products of OFLO was lower than LEV. This study demonstrated that AOPs (especially UV/PS) were efficient for removing fluoroquinolone antibiotics, which can be considered as a clean and green method for the treatment of antibiotics-containing industrial wastewater.

Polycyclic aromatic hydrocarbons (PAHs) residues have attracted attention worldwide. This study summarizes the current levels of PAH exposure in the water environments of lakes. In addition, the risk levels from individual PAHs and ΣPAHs in the water environments of lakes in China were evaluated by incremental lifetime cancer risk (ILCR) assessment, the toxic equivalent concentration (TEQBaP), the risk quotient (RQ), the effects range-low (ERL) and the effects range-median (ERM). The results showed that the concentrations of ∑PAHs in water and sediment ranged from 4.0 to 12,970.8 ng L−1 and 6.52 to 7935.21 ng g−1, respectively, and the highest concentrations of individual PAHs were of naphthalene (Nap) (6525 ng L−1), followed by indeno(1,2,3‑cd)pyrene (IcdP) (3452.6 ng g−1). Concentrations in the Great Lakes region in China showed spatial difference, with the Qinghai-Tibet Plateau Lakes District and Mongolia-Xinjiang Lakes District being less polluted. However, the pollution level of PAHs in lakes is relatively high at the global scale. The ecological risk assessment found a moderate level of ∑PAHs in water, but benz(a)anthracene (BaA) and phenanthrene (Phe) had high RQ values, which might pose a significant risk to aquatic organisms in lakes. Although the contents of ∑PAHs in sediments are low, most individual PAHs pose potential risks, especially acenaphthene (Ace), fluorene (Flu) and dibenz(a,h)anthracene (DahA). This study revealed the pollution levels of PAHs across China and provided a scientific basis for PAH pollution control and environmental protection.

The pollution of antibiotics and antibiotic resistance genes (ARGs) has been highlighted on a global scale because of their serious threats to the environment and human health. Typical urban water in cities with high population density are ideal mediums for the acquisition and spread of antibiotics and ARGs. The pollution level of a broad range of antibiotics and ARGs in hospital wastewater, groundwater and the Wenyu River, and their fates through three sewage treatment plants (STPs) were investigated in this study. The concentrations of the 11 detected antibiotics ranged from not detected (ND)-16800 ng L−1 in diverse water samples from Beijing, and fluoroquinolones were detected at the highest concentration, especially in the hospital samples. The maximum concentrations of antibiotics in STPs and hospital were 1–3 orders of magnitude higher than those in the surface water from Wenyu River and groundwater. Good removal efficiencies by treatment processes were observed for tetracyclines and quinolones, and low removal efficiencies were observed for sulfonamides and macrolides. These results also revealed that the sulfonamide resistance genes (sul1, sul2) and macrolide resistance genes (ermB) were detected at the highest relative abundances (7.11 × 10−2-1.18 × 10−1) in the water bodies of Beijing. It was worth noting that sul1 abundance was the highest in groundwater samples. The relative abundance of most ARGs in STPs exhibited a declining trend in the order of influent > secondary effluents > effluent. However, the relative abundance of sul 1, sul 2 and tetC in the effluent was higher than those in the influent. The incomplete removal of antibiotics and ARGs in STPs poses a serious threat to the receiving rivers, and affects ecosystem security. Overall, our findings provide favorable support for a further investigation of the spread and risk of antibiotics and ARGs from diverse sources (e.g., STPs and hospitals) to the aquatic environment.

In this study, 15 representative surface waters and sediments and seven typical fish were collected during the wet season in 2016 to explore the occurrence, chemical fractionation, and ecological risk of heavy metals (Cu, Zn, Pb, Cd, Cr, Hg, As, and Ni) in aquatic ecosystems of Dongting Lake in China. In surface water, the concentrations of all elements were lower than the third grade of the surface water quality standards (GB3838-2002). The highest concentrations of Zn, Pb, Cd, Ni, and Cu were found in the outlet of Dongting Lake, whereas As and Cr were highest in the Xiangjiang River Delta area. In surface sediments, the concentration decreased in the order of Zn > Cr > Pb > Cu > Ni > As>Cd > Hg; the highest concentration of all elements, except for Hg, was located in the Xiangjiang River Delta area; for chemical fractionation, Cr, Hg, Zn, As, Ni, and Cu were mainly residual fractionation; and Pb and Cd were mainly in a reducible state and fraction soluble in acid, respectively. In fish muscle, the concentrations of all elements were lower than relevant standards; the highest concentration appeared in fish living in the middle-lower and demersal layers. As for the feeding habits of fish, the average concentration decreased in the order of carnivorous > omnivorous > herbivorous fish. The potential ecological risk and the ratio of secondary phase to primary phase assessment showed that Cd and Hg had the highest ecological risk and that Cd and Pb had a high risk of secondary release. A health risk assessment showed that drinking water and fish for consumption in urban and rural areas around Dongting Lake were in the acceptable level.

With regard to the size of China’s freshwater lakes, Taihu Lake ranks third and it plays an important role in the supply of drinking water, flood prevention, farming and navigation, as well as in the travelling industry. The problem of environmental pollution has attracted widespread attention in recent years. In order to understand the levels, distribution and sources of heavy metals in sediments of Taihu Lake, random selection was carried out to obtain 59 samples of surface sediment from the entire lake and study the concentrations of Pb, Cd, Cu, Zn, Cr and Ni. Toxic units were also calculated to normalize the toxicities caused by various heavy metals. As a result, Cd and Cu in sediment were considered lower than the effect range low (ERL) at all regions where samples were gathered, while Pb and Ni were categorized into ERL-effect range median (ERM) at over 22% of the regions where samples were obtained. Nevertheless, all average concentrations of the samples were below the level of potential effect. According to the findings of this research, significant spatial heterogeneity existed in the above heavy metals. In conclusion, the distribution areas of heavy metals with higher concentrations were mainly the north bays, namely Zhushan Bay, Meiliang Bay as well as Gonghu Bay. The distribution areas of Cu, Zn, Cr and Ni with higher concentration also included the lake’s central region, whereas the uniform distribution areas of those with lower concentrations were the lake’s southeast region. In addition, it was most probable that the spatial distribution of heavy metals was determined by river inputs, whereas atmospheric precipitation caused by urban and traffic contamination also exerted considerable effects on the higher concentrations of Pb and Cd. Through evaluating the total amount of toxic units (ΣTU), it was found that higher toxicity existed primarily in the north bays and central region of the lake. If the heavy metals were sorted by the reduction of mean heavy metal toxic units in Taihu Lake in descending order, it would be Pb, Cr, Ni, Cd, Zn and Cu. Generally speaking, these result of analyses are conducive to alleviating the contamination of heavy metals in Taihu Lake.

Glutathione (GSH) plays crucial roles in antioxidant defense and detoxification metabolism of microcystin-LR (MC-LR). However, the detoxification process of MC-LR in mammals remains largely unknown. This paper, for the first time, quantitatively analyzes MC-LR and its GSH pathway metabolites (MC-LR-GSH and MC-LR-Cys) in the liver of Sprague-Dawley (SD) rat after MC-LR exposure. Rats received intraperitoneal (i.p.) injection of 0.25 and 0.5 lethal dose 50 (LD50) of MC-LR with or without pretreatment of buthionine-(S,R)-sulfoximine (BSO), an inhibitor of GSH synthesis. The contents of MC-LR-GSH were relatively low during the experiment; however, the ratio of MC-LR-Cys to MC-LR reached as high as 6.65 in 0.5 LD50 group. These results demonstrated that MC-LR-GSH could be converted to MC-LR-Cys efficiently, and this metabolic rule was in agreement with the data of aquatic animals previously reported. MC-LR contents were much higher in BSO + MC-LR-treated groups than in the single MC-LR-treated groups. Moreover, the ratio of MC-LR-Cys to MC-LR decreased significantly after BSO pretreatment, suggesting that the depletion of GSH induced by BSO reduced the detoxification of MCs. Moreover, MC-LR remarkably induced liver damage, and the effects were more pronounced in BSO pretreatment groups. In conclusion, this study verifies the role of GSH in the detoxification of MC-LR and furthers our understanding of the biochemical mechanism for SD rats to counteract toxic cyanobacteria.