Genome-wide identification of JAZ gene family members in autotetraploid cultivated alfalfa (Medicago sativa subsp. sativa) and expression analysis under salt stress.

BACKGROUND: Jasmonate ZIM-domain (JAZ) proteins, which act as negative regulators in the jasmonic acid (JA) signalling pathway, have significant implications for plant development and response to abiotic stress. RESULTS: Through a comprehensive genome-wide analysis, a total of 20 members of the JAZ gene family specific to alfalfa were identified in its genome. Phylogenetic analysis divided these 20 MsJAZ genes into five subgroups. Gene structure analysis, protein motif analysis, and 3D protein structure analysis revealed that alfalfa JAZ genes in the same evolutionary branch share similar exon‒intron, motif, and 3D structure compositions. Eight segmental duplication events were identified among these 20 MsJAZ genes through collinearity analysis. Among the 32 chromosomes of the autotetraploid cultivated alfalfa, there were 20 MsJAZ genes distributed on 17 chromosomes. Extensive stress-related cis-acting elements were detected in the upstream sequences of MsJAZ genes, suggesting that their response to stress has an underlying function. Furthermore, the expression levels of MsJAZ genes were examined across various tissues and under the influence of salt stress conditions, revealing tissue-specific expression and regulation by salt stress. Through RT‒qPCR experiments, it was discovered that the relative expression levels of these six MsJAZ genes increased under salt stress. CONCLUSIONS: In summary, our study represents the first comprehensive identification and analysis of the JAZ gene family in alfalfa. These results provide important information for exploring the mechanism of JAZ genes in alfalfa salt tolerance and identifying candidate genes for improving the salt tolerance of autotetraploid cultivated alfalfa via genetic engineering in the future.

An integrated analysis identifies six molecular subtypes of pancreatic ductal adenocarcinoma revealing cellular and molecular landscape.

Pancreatic ductal adenocarcinoma (PDA) has been found to have a high mortality rate. Despite continuous efforts, current histopathological classification is insufficient to guide individualized therapies of PDA. We first define the molecular subtypes of PDA (MSOP) based on a meta-cohort of 845 samples from 11 PDA datasets. We then performed functional analyses involving immunity, fibrosis and metabolism. We recognized six molecular subtypes with different survival statistics and molecular composition. The squamous basal-like (SBL) subtype had a poor prognosis and high infiltration of ENO1+ (Enolase 1)/ADM+ (Adrenomedullin) cancer-associated fibroblasts (CAFs). The immune mesenchymal-like (IML) subtype and the normal mesenchymal-like (NML) subtype were characterized by genes associated with extracellular matrix (ECM) activities and immune responses, having favorable prognoses. IML was featured by elevated exhausted immune signaling and inflammatory CAFs infiltration, whereas NML was featured with myofibroblastic CAFs infiltration. The exocrine-like (EL) subtype was high in exocrine signals, while the pure classical-like (PCL) subtype lacked immunocytes infiltration. The quiescent-like (QL) subtype had diminished metabolic signaling and high infiltration of NK cells. SBL, IML and NML were enriched in innate anti-PD-1 resistance signatures. In sum, this MSOP depicts a vivid cell-to-molecular atlas of the tumor microenvironment of PDA and might facilitate to design a precise combination of therapies that target immunity, metabolism and stroma.

Fast and Reversible Quasi-Solid-State Anion Exchange in Highly Luminescent CsPbX3 Perovskite Nanocrystals for Dual-Mode Encryption-Decryption.

Solid-state anion exchange method is easy to handle and beneficial to improve stability of CsPbX3 (X = Cl, Br, I) perovskites nanocrystals (NCs) with respect to anion exchange in liquid phase. However, the corresponding exchange rate is rather slow due to the limited diffusion rate of anions from solid phases, resulting in mixed-halide perovskite NCs. Herein,  a fast and reversible post-synthetic quasi-solid-state anion exchange method in CsPbX3 NCs with inorganic potassium halide KX salts/polyvinylpyrrolidone (PVP) thin film is firstly reported. Original morphology of the exchanged NCs is well-preserved for all samples. Complete anion exchange from Br- to Cl- or I- is successfully achieved in CsPbX3 NCs within ≈20 min through possible vacancies-assisted ion exchange mechanism, under ambient conditions and vice versa. Particularly, Br- -exchanged CsPbCl3 and CsPbI3 NCs exhibit improved optical properties. Encouraged by the attractive fluorescence and persistent luminescence as well as good stability of the resulted CsPbX3 NCs, an effective dual-mode information storage-reading application is demonstrated.  It is believed that this method can open a new avenue for the synthesis of other direct-synthesis challenging quantum-confined perovskite NCs/nanoplates/nanodisks or CsSnX3 NCs/thin film and provide an opportunity for advanced information storage compatible for practical applications.

Genome-Wide Identification and Characterization of the Msr Gene Family in Alfalfa under Abiotic Stress.

Alfalfa (Medicago sativa) is an important leguminous forage, known as the "The Queen of Forages". Abiotic stress seriously limits the growth and development of alfalfa, and improving the yield and quality has become an important research area. However, little is known about the Msr (methionine sulfoxide reductase) gene family in alfalfa. In this study, 15 Msr genes were identified through examining the genome of the alfalfa "Xinjiang DaYe". The MsMsr genes differ in gene structure and conserved protein motifs. Many cis-acting regulatory elements related to the stress response were found in the promoter regions of these genes. In addition, a transcriptional analysis and qRT-PCR (quantitative reverse transcription PCR) showed that MsMsr genes show expression changes in response to abiotic stress in various tissues. Overall, our results suggest that MsMsr genes play an important role in the response to abiotic stress for alfalfa.

Computational Insight into Biotransformation Profiles of Organophosphorus Flame Retardants to Their Diester Metabolites by Cytochrome P450.

Biotransformation of organophosphorus flame retardants (OPFRs) mediated by cytochrome P450 enzymes (CYPs) has a potential correlation with their toxicological effects on humans. In this work, we employed five typical OPFRs including tris(1,3-dichloro-2-propyl) phosphate (TDCIPP), tris(1-chloro-2-propyl) phosphate (TCIPP), tri(2-chloroethyl) phosphate (TCEP), triethyl phosphate (TEP), and 2-ethylhexyl diphenyl phosphate (EHDPHP), and performed density functional theory (DFT) calculations to clarify the CYP-catalyzed biotransformation of five OPFRs to their diester metabolites. The DFT results show that the reaction mechanism consists of Cα-hydroxylation and O-dealkylation steps, and the biotransformation activities of five OPFRs may follow the order of TCEP ≈ TEP ≈ EHDPHP > TCIPP > TDCIPP. We further performed molecular dynamics (MD) simulations to unravel the binding interactions of five OPFRs in the CYP3A4 isoform. Binding mode analyses demonstrate that CYP3A4-mediated metabolism of TDCIPP, TCIPP, TCEP, and TEP can produce the diester metabolites, while EHDPHP metabolism may generate para-hydroxyEHDPHP as the primary metabolite. Moreover, the EHDPHP and TDCIPP have higher binding potential to CYP3A4 than TCIPP, TCEP, and TEP. This work reports the biotransformation profiles and binding features of five OPFRs in CYP, which can provide meaningful clues for the further studies of the metabolic fates of OPFRs and toxicological effects associated with the relevant metabolites.

Cytochrome P450 Enzymes and Drug Metabolism in Humans.

Human cytochrome P450 (CYP) enzymes, as membrane-bound hemoproteins, play important roles in the detoxification of drugs, cellular metabolism, and homeostasis. In humans, almost 80% of oxidative metabolism and approximately 50% of the overall elimination of common clinical drugs can be attributed to one or more of the various CYPs, from the CYP families 1-3. In addition to the basic metabolic effects for elimination, CYPs are also capable of affecting drug responses by influencing drug action, safety, bioavailability, and drug resistance through metabolism, in both metabolic organs and local sites of action. Structures of CYPs have recently provided new insights into both understanding the mechanisms of drug metabolism and exploiting CYPs as drug targets. Genetic polymorphisms and epigenetic changes in CYP genes and environmental factors may be responsible for interethnic and interindividual variations in the therapeutic efficacy of drugs. In this review, we summarize and highlight the structural knowledge about CYPs and the major CYPs in drug metabolism. Additionally, genetic and epigenetic factors, as well as several intrinsic and extrinsic factors that contribute to interindividual variation in drug response are also reviewed, to reveal the multifarious and important roles of CYP-mediated metabolism and elimination in drug therapy.

Activation of Kagome lattice-structured Cu3V2O7(OH)2·2H2O volborthite via hydrothermal crystallization for boosting visible light-driven water oxidation.

We report a feasible strategy via hydrothermal crystallization to activate Kagome lattice-structured Cu3V2O7(OH)2·2H2O volborthite mineral as a stable visible-light-driven photocatalyst. It was demonstrated to play a crucial role in stimulating absorption ability and photodegradation performance for the removal of methylene blue present in high concentration. In contrast, direct calcination was almost ineffective, whereas post-calcination was significantly detrimental. Moreover, the photocatalytic water oxidation activity of hydrothermally crystallizated volborthite was comparable to that of BiVO4, and it was clearly higher than those of WO3 and g-C3N4 from aqueous NaIO3 solution. By further in situ decoration with an optimum amount of CoOx cocatalysts (i.e., 2 wt%), the oxygen evolution rate of volborthite was greatly enhanced, and it was 1.6-fold, 1.8-fold and 2.9-fold higher than those of BiVO4, WO3 and g-C3N4, respectively. The importance of hydrothermal crystallization can be elucidated in terms of water-Kagome lattice structure interactions involving built-in intrinsic electric field and formation of single hydrogen bonds.

Nicotine induces Nme2-mediated apoptosis in mouse testes.

In mouse testes, germ cell apoptosis can be caused by cigarette smoke and lead to declining quality of semen, but the exact molecular mechanisms remain unclear. To evaluate the effects of nicotine exposure on apoptosis during spermatogenesis, we first constructed a nicotine-treated mouse model and detected germ cell apoptosis activity in the testes using the TUNEL method. Then we analyzed the variation of telomere length and telomerase activity by real-time PCR and TRAP-real-time PCR, respectively. Further, we investigated a highly expressed gene, Nme2, in mouse testes after nicotine treatment from our previous results, which has close correlation with the apoptosis activity predicted by bioinformatics. We performed NME2 overexpression in Hela cells to confirm whether telomere length and telomerase activity were regulated by the Nme2 gene. Finally, we examined methylation of CpG islands in the Nme2 promoter with the Bisulfite Sequencing (BSP) method. The results showed that apoptosis had increased significantly, and then telomerase activity became weak. Further, telomere length was shortened in the germ cells among the nicotine-treated group. In Hela cells, both overexpression of the Nme2 gene and nicotine exposure can suppress the activity of telomerase activity and shorten telomere length. BSP results revealed that the Nme2 promoter appeared with low methylation in mouse testes after nicotine treatment. We assume that nicotine-induced apoptosis may be caused by telomerase activity decline, which is inhibited by the up expression of Nme2 because of its hypomethylation in mouse germ cells.

Nicotine Induced Murine Spermatozoa Apoptosis via Up-Regulation of Deubiquitinated RIP1 by Trim27 Promoter Hypomethylation.

Nicotine significantly promoted apoptosis in stages I, VII, VIII, and XI spermatogonia, stages I, VII, VIII, X, and XI spermatocytes, and stages I-V, VII, and VIII elongating spermatids. To explore the underlying molecular mechanisms, sperm mRNA next-generation sequencing of nicotine-treated mice was conducted. Out of the 86 genes related to apoptosis, Tnf (tumor necrosis factor alpha) was screened to be the most significant varied transcript, and the Onto-pathway analysis indicated that the TNF apoptotic pathway was especially activated by nicotine exposure. The TNF pathway was further studied at the gene and protein levels. The results showed that RIP1, the key component in the TNF apoptotic pathway, was up-expressed in its deubiquitinated form in nicotine-treated mice testis. TRIM27, an E3 ubiquitin ligase that activated TNF apoptotic pathway through up-regulating deubiquitinated RIP1, was also overexpressed in nicotine-treated spermatocytes; moreover, four consecutive CpG sites near the Trim27 transcription start site were less frequently methylated. Finally, in vitro experiments of Trim27 overexpression and RNA interference in GC-1 spermatogonial cells confirmed that the RIP1 deubiquitination and TRIM27 hyopmethylation were both positively correlated with spermatocyte apoptosis. In summary, our study suggests that nicotine may induce murine spermatozoal apoptosis via the TNF apoptotic pathway through up-regulation of deubiquitinated RIP1 by Trim27 promoter hypomethylation.

Protein profile screening: reduced expression of Sord in the mouse epididymis induced by nicotine inhibits tyrosine phosphorylation level in capacitated spermatozoa.

Many studies have revealed the hazardous effects of cigarette smoking and nicotine exposure on male fertility, but the actual, underlying molecular mechanism remains relatively unclear. To evaluate the detrimental effects of nicotine exposure on the sperm maturation process, two-dimensional gel electrophoresis and mass spectrometry analyses were performed to screen and identify differentially expressed proteins from the epididymal tissue of mice exposed to nicotine. Data mining analysis indicated that 15 identified proteins were mainly involved in the molecular transportation process and the polyol pathway, indicating impaired epididymal secretory functions. Experiments in vitro confirmed that nicotine inhibited tyrosine phosphorylation levels in capacitated spermatozoa via the downregulated seminal fructose concentration. Sord, a key gene encoding sorbitol dehydrogenase, was further investigated to reveal that nicotine induced hyper-methylation of the promoter region of this gene. Nicotine-induced reduced expression of Sord could be involved in impaired secretory functions of the epididymis and thus prevent the sperm from undergoing proper maturation and capacitation, although further experiments are needed to confirm this hypothesis.

Estimated diversity of messenger RNAs in each murine spermatozoa and their potential function during early zygotic development.

To study the diversity of mRNAs in murine spermatozoa and their potential function during zygotic development, total RNAs in murine spermatozoa were sequenced via RNA-Seq and analyzed through bioinformatics techniques. The delivery and translation of sperm-borne mRNA in fertilized oocyte were detected using RT-PCR (reverse transcription-polymerase chain reaction), Western blot, and immunofluorescence. A total of 35 288 825 reads matching 33 039 transcripts, including 27 310 coding transcripts, were obtained. Based on our analyses, we hypothesized that the transcripts with RPKM (reads per kilobase of exon model per million mapped reads) higher than six may exist in each sperm cell as consistently retained transcripts. There were 4885 consistent transcripts in each sperm, and the remainder were randomly retained. If the baseline RPKM increased, the remaining coding transcripts were more likely related to reproduction and development. The sperm-borne transcripts Wnt4 and Foxg1 were delivered into fertilized oocytes on fertilization. Furthermore, Wnt4 was translated into protein in zygotes, whereas Foxg1 was not translated. In conclusion, approximately 4885 mRNAs were present in each murine spermatozoon, and the spermatozoal mRNAs related to reproduction and development were more likely retained. The sperm-borne mRNA Wnt4 was delivered into the fertilized oocyte and translated, evidence of a paternal effect on zygotic development.

One-step strategy for the synthesis of a derivatized cyclodextrin-based monolithic column.

Derivatized ß-cyclodextrin (ß-CD) functionalized monolithic columns were prepared by a "one-step" strategy using click chemistry. First, the intended derivatized ß-CD monomers were synthesized by a click reaction between propargyl methacrylate and mono-6-azido-ß-CD and then sulfonation or methylation was carried out. Finally, monolithic columns were prepared through a one-step in situ copolymerization of the derivatized ß-CD monomer and ethylene glycol dimethacrylate. The sulfated ß-CD-based monolith was successfully applied to the hydrophilic interaction liquid chromatography separation of nucleosides and small peptides, while the methylated ß-CD-functionalized monolith was useful for the separation of nonpolar compounds and drug enantiomers in capillary reversed-phase liquid chromatography. The structures of the monomers were characterized by Fourier transform infrared spectroscopy and mass spectrometry. The physicochemical properties and column performance of monoliths were evaluated by scanning electron microscopy and micro high performance liquid chromatography. This strategy has considerable prospects for the preparation of other derivatized CD-functionalized methacrylate monoliths.

Whole-genome sequencing and RNA sequencing analysis reveals novel risk genes and differential expression patterns in hepatoblastoma.

Hepatoblastoma (HB) is an uncommon malignant liver cancer primarily affecting infants and children, characterized by the presence of tissue that resembling fetal hepatocytes, mature liver cells or bile duct cells. The primary symptom in affected children is abdominal lumps. HB constitutes approximately 28% of all liver tumors and two-thirds of liver malignancies in the pediatric and adolescent population. Despite its high prevalence, the underlying mechanism of HB pathogenesis remain largely unknown. To reveal the genetic alternations associated with HB, we conducted a comprehensive genomic study using whole-genome sequencing (WGS) and RNA sequencing (RNA-seq) techniques on five HB patients. We aimed to use WGS to identify somatic variant loci associated with HB, including single nucleotide polymorphisms (SNPs), insertions and deletions (Indels), and copy number variations (CNVs). Notably, we found deleterious mutation in CTNNB1, AXIN2 and PARP1, previously implicated in HB. In addition, we discovered multiple novel genes potentially associated with HB, including BRCA2 and GPC3 which require further functional validation to reveal their contributions to HB development. Furthermore, the American College of Medical Genetics and Genomics (ACMG) analysis identified the ABCC2 gene was the pathogenic gene as a potential risk gene linked with HB. To study the gene expression patterns in HB, we performed RNA-seq analysis and qPCR validation to reveal differential expression of four candidate genes (IGF1R, METTL1, AXIN2 and TP53) in tumors compared to nonneoplastic liver tissue in HB patients (P-Val < 0.01). These findings shed lights on the molecular mechanisms underlying HB development and facilitate to advance future personalized diagnosis and therapeutic interventions of HB.

Mechanistic insight into biotransformation of novel triazine-based flame retardant 1,3,5-tris(2,3-dibromopropyl)-1,3,5-triazinane-2,4,6-trione by human cytochrome P450s.

The escalating focus on the environmental occurrence and toxicology of emerging pollutants underscores the imperative need for a profound exploration of their metabolic transformations mediated by human CYP450 enzymes. Such investigations have the potential to unravel the intricate metabolite profiles, substantially altering the toxicological outcomes. In this study, we integrated the computational simulations with in vitro metabolism experiments to investigate the metabolic activity and mechanism of an emerging pollutant, 1,3,5-tris(2,3-dibromopropyl)-1,3,5-triazinane-2,4,6-trione (TDBP-TAZTO), catalyzed by human CYP450s. The results highlight the important contributions of CYP2E1, 3A4 and 2C9 to the biotransformation of TDBP-TAZTO, leading to the identification of four distinct metabolites. The effective binding conformations governing biotransformation reactions of TDBP-TAZTO within active CYP450s are unveiled. Structural instability of primary hydroxyTDBP-TAZTO products suggests three potential outcomes: (1) generation of an alcohol metabolite through successive debromination and reduction reactions, (2) formation of a dihydroxylated metabolite through secondary hydroxylation by CYP450, and (3) production of an N-dealkylated metabolite via decomposition and isomerization reactions in the aqueous environment. The formation of a desaturated debrominated metabolite may arise from H-abstraction and barrier-free Br release during the primary oxidation, potentially competing with the generation of hydroxyTDBP-TAZTO. These findings provide detailed mechanistic insight into TDBP-TAZTO biotransformation by CYP450s, which can enrich our understanding of the metabolic fate and associated health risk of this chemical.

A Multistate Thermoresponsive Smart Window Based on a Multifunctional Luminescent Solar Concentrator.

Conventional luminescent solar concentrators (LSCs) usually only have the ability to absorb solar energy and convert it to electricity but are not able to regulate the transmitted light. Herein, a multistate thermoresponsive smart window (SW) based on LSC has been fabricated, in which the stimuli-responsive host layer consists of polydimethylsiloxane (PDMS) and ethylene glycol solution (EGS) microdroplets stacking with LSC layer-based on near-infrared (NIR) CuInSe2-xSx/ZnS core/shell quantum dots (QDs) and PDMS matrix. As-synthesized CISSe/ZnS QDs with broad NIR absorption in LSC exhibit controllable emission spectra over 833-1088 nm and high photoluminescence (PL) quantum yield from 45 to 83%. Coupling with Si solar cells as a reference, optimized LSC-SW devices with dimensions of 5 × 5 × 0.9 cm3 exhibit higher power conversion efficiency (PCE) of 1.19-1.36% with increased temperature from 0 to 50 °C than those of sole LSC and SW devices. The corresponding visible light transmissions are regulated from 75.1 to 48.1% accordingly. The improvement of PCEs in an opaque state is mainly due to enhanced absorption of QDs originating from rescattered photons from the EGS/PDMS layer, leading to more emitted photons reaching photovoltaics. This work is expected to bring up new opportunities for applications in greenhouses, building facades, and energy-efficient smart windows.

Highly efficient and stable tandem luminescent solar concentrators based on carbon dots and CuInSe2-xSx/ZnS quantum dots.

Semi-transparent large-area luminescent solar concentrators (LSCs) have been considered an essential part of zero-energy or low-energy consuming buildings in the future. Inorganic colloidal quantum dots (QDs) are promising candidates for LSCs due to the advantages of a tunable bandgap, engineered large Stokes shift, and relatively high photoluminescence (PL) quantum yield. However, LSCs that are fabricated using colloidal quantum dots exhibited an inferior stability under long-term illumination, demanding great efforts to explore the highly stable LSCs. Herein, we fabricated large-area (∼100 cm2) tandem LSCs based on highly stable carbon dots (CDs) and highly luminescent near-infrared emitting CuInSe2-xSx/ZnS (CuInSeS/ZnS) QDs. Coupled with a Si diode as a reference, the power conversion efficiency of the corresponding tandem (dimensions: 10 × 10 × 0.5 cm3) and single LSCs (dimensions: 10 × 10 × 0.3 cm3) based on CuInSeS/ZnS QDs under one sun illumination are 0.46% and 0.5%, respectively. For single CuInSeS/ZnS QD based LSCs at a low concentration (0.039 wt%), external and internal quantum efficiencies reach up to 2.87% and 36.37%, respectively. After UV illumination for 8 h, bottom LSCs based on CuInSeS/ZnS QDs retain 93.22% of the initial PL emission, which is higher than that of LSCs (∼80%) without the CD protection. The highly efficient and stable tandem LSCs employing green CDs and NIR CuInSeS/ZnS QDs as PL emitters pave the way for the realization of large area building-integrated photovoltaic (BIPV) devices.

Thyroid hormone activities of neutral and anionic hydroxylated polybrominated diphenyl ethers to thyroid receptor ß: A molecular dynamics study.

Hydroxylated polybrominated diphenyl ethers (OH-PBDEs) have been identified as the strong endocrine disrupting chemicals to humans, which show structural similarity with endogenous thyroid hormones (THs) and thus disrupt the functioning of THs through competitive binding with TH receptors (TRs). Although previous studies have reported the hormone activities of some OH-PBDEs on TH receptor ß (TRß), the interaction mechanism remains unclear. Furthermore, hydroxyl dissociation of OH-PBDEs may alter their TR disrupting activities, which has not yet been investigated in depth. In this work, we selected 18 OH-PBDEs with neutral and anionic forms and performed molecular dynamics (MD) simulations to estimate their binding interactions with the ligand binding domain (LBD) of TRß. The results demonstrate that most of OH-PBDEs have stronger binding affinities to TRß-LBD than their anionic counterparts, and the hydroxyl dissociation of ligands differentiate the major driving force for their binding. More Br atoms in OH-PBDEs can result in stronger binding potential with TRß-LBD. Moreover, 5 hydrophobic residues, including Met313, Leu330, Ile276, Leu346, and Phe272, are identified to have important contributions to bind OH-PBDEs. These results clarify the binding mechanism of OH(O-)-PBDEs to TRß-LBD at the molecular level, which can provide a solid theoretical basis for accurate assessment of TH disrupting effects of these chemicals.

Characterization of short-, medium- and long-chain chlorinated paraffins in ambient PM2.5 from the Pearl River Delta, China.

Research on the environmental occurrence of long-chain chlorinated paraffins (LCCPs) in ambient fine particulate matter (PM2.5) is still scarce. In the present study, short-chain chlorinated paraffins (SCCPs), medium-chain chlorinated paraffins (MCCPs) and LCCPs were simultaneously quantified and profiled in PM2.5 samples collected from 96 primary or secondary schools in the Pearl River Delta of South China. SCCPs, MCCPs and LCCPs were detected in higher than 90% samples with concentrations in the range of 0.832-109, 1.02-110, and 0.173-17.4 ng/m3, respectively. The dominant congener groups of SCCPs, MCCPs and LCCPs were C13Cl6-8, C14Cl7-8, and C18Cl7-9, respectively. The concentrations of SCCPs and MCCPs were higher in summer than in winter, while an opposite seasonal trend was observed for LCCPs. Principal components analysis showed there were seasonal variations in the congener group patterns with C13Cl6-7 and C14Cl7 more abundant in summer than in winter. Concentrations of CPs also exhibited slight spatial variations. Exposure risk assessment based on different age groups suggested exposure to PM2.5-associated CPs would not pose significant health risk. The present study expands the existing knowledge of CPs contamination in atmospheric environment.

Ultralow-iridium content NiIr alloy derivative nanochain arrays as bifunctional electrocatalysts for overall water splitting.

The development of low-cost and high-durability bifunctional electrocatalysts is of considerable importance for overall water splitting (OWS). This work reports the controlled synthesis of nickel-iridium alloy derivative nanochain array electrodes (NiIrx NCs) with fully exposed active sites that facilitated mass transfer for efficient OWS. The nanochains have a self-supported three-dimensional core-shell structure, composed of a metallic NiIrx core and a thin (5-10 nm) amorphous (hydr)oxide film as the shell (e.g., IrO2/NiIrx and Ni(OH)2/NiIrx). Interestingly, NiIrx NCs have bifunctional properties. Particularly, the oxygen evolution reaction (OER) current density (electrode geometrical area) of NiIr1 NCs is four times higher than that of IrO2 at 1.6 V vs. RHE. Meanwhile, its hydrogen evolution reaction (HER) overpotential at 10 mA cm-2 (η10 = 63 mV) is comparable to that of 10 wt% Pt/C. These performances may originate from the interfacial effect between the surface (hydr)oxide shell and metallic NiIrx core, which facilitates the charge transfer, along with the synergistic effect between Ni2+ and Ir4+ in the (hydr)oxide shell. Furthermore, NiIr1 NCs exhibits excellent OER durability (100 h @ 200 mA cm-2) and OWS durability (100 h @ 500 mA cm-2) with the nanochain array structure well preserved. This work provides a promising route for developing effective bifunctional electrocatalysts for OWS applications.

Coexistence of antibiotic resistance genes, fecal bacteria, and potential pathogens in anthropogenically impacted water.

Microbial indicators are often used to monitor microbial safety of aquatic environments. However, information regarding the correlation between microbial indicators and ecotoxicological factors such as potential pathogens and antibiotic resistance genes (ARGs) in anthropogenically impacted waters remains highly limited. Here, we investigated the bacterial community composition, potential pathogens, ARGs diversity, ARG hosts, and horizontal gene transfer (HGT) potential in urban river and wastewater samples from Chaohu Lake Basin using 16S rRNA and metagenomic sequencing. The composition of the microbial community and potential pathogens differed significantly in wastewater and river water samples, and the total relative abundance of fecal indicator bacteria was positively correlated with the total relative abundance of potential pathogens (p < 0.001 and Pearson's r = 0.758). Network analysis indicated that partial ARG subtypes such as dfrE, sul2, and PmrE were significantly correlated with indicator bacteria (p < 0.05 and Pearson's r > 0.6). Notably, Klebsiella was the indicator bacteria significantly correlated with 4 potential pathogens and 14 ARG subtypes. ARGs coexisting with mobile gene elements were mainly found in Thauera, Pseudomonas, Escherichia, and Acinetobacter. Next-generation sequencing (NGS) can be used to conduct preliminary surveys of environmental samples to access potential health risks, thereby facilitating water resources management.