Joint transcriptomic and metabolomic analysis provides new insights into drought resistance in watermelon (Citrullus lanatus).

Introduction: Watermelon is an annual vine of the family Cucurbitaceae. Watermelon plants produce a fruit that people love and have important nutritional and economic value. With global warming and deterioration of the ecological environment, abiotic stresses, including drought, have become important factors that impact the yield and quality of watermelon plants. Previous research on watermelon drought resistance has included analyzing homologous genes based on known drought-responsive genes and pathways in other species. Methods: However, identifying key pathways and genes involved in watermelon drought resistance through high-throughput omics methods is particularly important. In this study, RNA-seq and metabolomic analysis were performed on watermelon plants at five time points (0 h, 1 h, 6 h, 12 h and 24 h) before and after drought stress. Results: Transcriptomic analysis revealed 7829 differentially expressed genes (DEGs) at the five time points. The DEGs were grouped into five clusters using the k-means clustering algorithm. The functional category for each cluster was annotated based on the Kyoto Encyclopedia of Genes and Genomes (KEGG) database; different clusters were associated with different time points after stress. A total of 949 metabolites were divided into 10 categories, with lipids and lipid-like molecules accounting for the most metabolites. Differential expression analysis revealed 22 differentially regulated metabolites (DRMs) among the five time points. Through joint analysis of RNA-seq and metabolome data, the 6-h period was identified as the critical period for watermelon drought resistance, and the starch and sucrose metabolism, plant hormone signal transduction and photosynthesis pathways were identified as important regulatory pathways involved in watermelon drought resistance. In addition, 15 candidate genes associated with watermelon drought resistance were identified through joint RNA-seq and metabolome analysis combined with weighted correlation network analysis (WGCNA). Four of these genes encode transcription factors, including bHLH (Cla97C03G068160), MYB (Cla97C01G002440), HSP (Cla97C02G033390) and GRF (Cla97C02G042620), one key gene in the ABA pathway, SnRK2-4 (Cla97C10G186750), and the GP-2 gene (Cla97C05G105810), which is involved in the starch and sucrose metabolism pathway. Discussion: In summary, our study provides a theoretical basis for elucidating the molecular mechanisms underlying drought resistance in watermelon plants and provides new genetic resources for the study of drought resistance in this crop.

In-situ precipitation zero-valent Co on Co2VO4 to activate oxygen vacancies and enhance bimetallic ions redox for efficient detection toward Hg(II).

Despite the widespread utilization of variable valence metals in electrochemistry, it is still a formidable challenge to enhance the valence conversion efficiency to achieve excellent catalytic activity without introducing heterophase elements. Herein, the in-situ precipitation of Co particles on Co2VO4 not only enhanced the concentration of oxygen vacancies (Ov) but also generated a greater number of low-valence metals, thereby enabling efficient reduction towards Hg(II). The electroanalysis results demonstrate that the sensitivity of Co/Co2VO4 towards Hg(II) was measured at an impressive value of 1987.74 µA µM-1 cm-2, significantly surpassing previously reported results. Further research reveals that Ov acted as the main adsorption site to capture Hg(II). The redox reactions of Co2+/Co3+ and V3+/V4+ played a synergistic role in the reduction of Hg(II), accompanied by the continuous supply of electrons from zero-valent Co to expedite the valence cycle. The Co/Co2VO4/GCE presented remarkable selectivity towards Hg(II), with excellent stability, reproducibility, and anti-interference capability. The electrode also exhibited minimal sensitivity fluctuations towards Hg(II) in real water samples, underscoring its practicality for environmental applications. This study elucidates the mechanism underlying the surface redox reaction of metal oxides facilitated by zero-valent metals, providing us with new strategies for further design of efficient and practical sensors.

Optimization of Online Soluble Solids Content Detection Models for Apple Whole Fruit with Different Mode Spectra Combined with Spectral Correction and Model Fusion.

Soluble solids content (SSC) is one of the main quality indicators of apples, and it is important to improve the precision of online SSC detection of whole apple fruit. Therefore, the spectral pre-processing method of spectral-to-spectral ratio (S/S), as well as multiple characteristic wavelength member model fusion (MCMF) and characteristic wavelength and non-characteristic wavelength member model fusion (CNCMF) methods, were proposed for improving the detection performance of apple whole fruit SSC by diffuse reflection (DR), diffuse transmission (DT) and full transmission (FT) spectra. The modeling analysis showed that the S/S- partial least squares regression models for all three mode spectra had high prediction performance. After competitive adaptive reweighted sampling characteristic wavelength screening, the prediction performance of all three model spectra was improved. The particle swarm optimization-extreme learning machine models of MCMF and CNCMF had the most significant enhancement effect and could make all three mode spectra have high prediction performance. DR, DT, and FT spectra all had some prediction ability for apple whole fruit SSC, with FT spectra having the strongest prediction ability, followed by DT spectra. This study is of great significance and value for improving the accuracy of the online detection model of apple whole fruit SSC.

MbEOMT1 regulates methyleugenol biosynthesis in Melaleuca bracteata F. Muell.

Methyleugenol, a bioactive compound in the phenylpropene family, undergoes its final and crucial biosynthetic transformation when eugenol O-methyltransferase (EOMT) converts eugenol into methyleugenol. While Melaleuca bracteata F. Muell essential oil is particularly rich in methyleugenol, it contains only trace amounts of its precursor, eugenol. This suggests that the EOMT enzyme in M. bracteata is highly efficient, although it has not yet been characterized. In this study, we isolated and identified an EOMT gene from M. bracteata, termed MbEOMT1, which is primarily expressed in the flowers and leaves and is inducible by methyl jasmonate (MeJA). Subcellular localization of MbEOMT1 in the cytoplasm was detected. Through transient overexpression experiments, we found that MbEOMT1 significantly elevates the concentration of methyleugenol in M. bracteata leaves. Conversely, silencing of MbEOMT1 via virus-induced gene silencing led to a marked reduction in methyleugenol levels. Our in vitro enzymatic assays further confirmed that MbEOMT1 specifically catalyzes the methylation of eugenol. Collectively, these findings establish that the MbEOMT1 gene is critical for methyleugenol biosynthesis in M. bracteata. This study enriches the understanding of phenylpropene biosynthesis and suggests that MbEOMT1 could serve as a valuable catalyst for generating bioactive compounds in the future.

Phosphorus-doped synergy of phase change in heterogeneous catalysts of NiS-NiS2 for efficient electrocatalysis of Pb(II).

A fundamental understanding of the electroanalytical activity of transition metal sulfide electrocatalysts, especially the origin of the electrocatalytic reactivity on the surface sites of heterostructures with multiple crystalline phases, is essential for the design of low-cost and highly efficient nonprecious metal electrocatalysts for further scientific and technological achievements. Herein, we injected P into NiS and occupied the S sites through a doping strategy. The redistributed electronic structure induced the construction of heterostructures, which significantly improved the structure and chemical state of electrochemically inert NiS. The phase-change mechanism between NiS and NiS2 synergistically catalyzes Pb(II), while the P and S sites jointly lose electrons. Moreover, the constructed heterojunction sensor shows the a sensitivity of 83.43 µA µM-1 to Pb(II) with a theoretical limit of detection of 48 nM, as well as excellent stability, reproducibility, and anti-interference ability. The accurate detection in real water further reveals the potential of this sensor for practical applications. This study provides a guiding strategy for improving electrochemically inert materials to design highly active electrocatalytic interfaces, which has important implications for the development of highly efficient electrode-sensitive materials similar to precious metals to achieve accurate electrical analysis.

PTPN13 rs989902 and CHEK2 rs738722 are associated with esophageal cancer.

PURPOSE: Individual genetic background can play an essential role in determining the development of esophageal squamous cell carcinoma (ESCC). PTPN13 and CHEK2 play important roles in the pathogenesis of ESCC. This case-control study aimed to analyze the association between gene polymorphisms and ESCC susceptibility. METHODS: DNA was extracted from the peripheral blood of patients. The Agena MassARRAY platform was used for the genotyping. Statistical analysis was conducted using the chi-squared test or Fisher's exact test, logistic regression analysis, and stratification analysis. RESULTS: The 'G' allele of rs989902 (PTPN13) and the 'T' allele of rs738722 (CHEK2) were both associated with an increased risk of ESCC (rs989902: OR = 1.23, 95% CI = 1.02-1.47, p = 0.028; rs738722: OR = 1.28, 95% CI = 1.06-1.55, p = 0.011). Stratification analysis showed that SNPs (rs989902 and rs738722) were notably correlated with an increased risk of ESCC after stratification for age, sex, smoking, and drinking status. In addition, rs738722 might be associated with lower stage, while rs989902 had a lower risk of metastasis. CONCLUSION: Our findings display that PTPN13 rs989902 and CHEK2 rs738722 are associated with an increased risk of ESCC in the Chinese Han population.

Association study for the role of MMP8 gene polymorphisms in Colorectal cancer susceptibility.

BACKGROUND: Colorectal cancer (CRC) is one of the most common malignant tumors, influenced by several genetic loci in its clinical phenotypes. The aim of this study was to determine the relationship between the MMP8 gene polymorphism and CRC risk in the Chinese Han population. METHOD: This study recruited 688 CRC patients and 690 healthy controls. The relationship between MMP8 polymorphism and CRC susceptibility was assessed by calculating the odds ratio (OR) and 95% confidence interval (CI) after stratifying by age, gender, body mass index (BMI), smoking, and alcohol consumption under a multi-genetic model. RESULTS: MMP8 rs3740938 was associated with increased CRC predisposition (p = 0.016, OR = 1.24, 95% CI: 1.04-1.48), and this association was detected particularly in subjects aged > 60 years, females, people with BMI > 24 kg/m2, smokers, and drinkers. Moreover, rs3740938 was found to be associated with the pathological type of rectal cancer. CONCLUSIONS: Our results first displayed that rs3740938 in MMP8 was a risk factor for CRC predisposition. This finding may provide a new biological perspective for understanding the role of the MMP8 gene in CRC pathogenesis.

Dietary exposure to sulfamethazine alters fish intestinal homeostasis and promotes resistance gene transfer.

The present study was undertaken to explore the effects of sulfamethazine (SMZ) dietary exposure on the enrichment of the intestine microbial structure, and antibiotic resistance gene (ARGs) transmission in marine medaka, with respect to antibiotic dose, duration, and sex. In male fish, a dietary exposure of 10 µg/L SMZ led to a heightened SMZ enrichment in the intestine, whereas metabolite (N-SMZ) levels were elevated at a higher exposure concentration (100 µg/L). Conversely, female fish exhibited stable levels of accumulation and metabolic rates across the exposure period. The composition of intestinal microorganisms revealed that exposure duration exerted a greater impact on the abundance and diversity of gut microbes, and microbial responses to SMZ varied across exposure time points. The expansion of Bacteroidetes and Ruegeria likely stimulated SMZ metabolism and contributed to the more balanced level of SMZ and N-SMZ observed in females. In males, short-term SMZ stress resulted in a disruption of intestinal homeostasis, while the rise in the abundance of the Fusobacteria and Propionigeniuma suggested a potential enhancement in intestinal anti-inflammatory capacity over time. Overall, female medaka exhibited greater adaptability to SMZ, and males appear to experience prolonged effects due to SMZ. A total of 11 ARGs and 5 mobile genetic elements (MGEs) were identified. Ruegeria is the main carrier of two types of MGEs (IS1247, ISSm2-Xanthob), and may serve as an indicator of ARG transmission. Therefore, it is rational to consider some fish breeding areas in natural waters as potential "reservoirs" of antibiotic resistance. This research will provide a valuable reference for the transmission of drug resistance along the food chain.

Revealing the solid-solution interface interference behaviors between Cu2+ and As(III) via partial peak area analysis of simulations and experiments.

The mutual interference in the sensing detection of heavy metal ions (HMIs) is considerably serious and complex. Besides, the co-existed ions may change the stripping peak intensity, shape and position of the target ion, which partly makes peak current analysis inaccurate. Herein, a promising approach of partial peak area analysis was proposed firstly to research the mutual interference. The interference between two species on their electrodeposition processes was investigated by simulating different kinetics parameters, including surface coverage, electro-adsorption, -desorption rate constant, etc. It was proved that the partial peak area is sensitive and regular to these interference kinetics parameters, which is favorable for distinctly identifying different interferences. Moreover, the applicability of the partial peak area analysis was verified on the experiments of Cu2+, As(III) interference at four sensing interfaces: glassy carbon electrode, gold electrode, Co3O4, and Fe2O3 nanoparticles modified electrodes. The interference behaviors between Cu2+ and As(III) relying on solid-solution interfaces were revealed and confirmed by physicochemical characterizations and kinetics simulations. This work proposes a new descriptor (partial peak area) to recognize the interference mechanism and provides a meaningful guidance for accurate detection of HMIs in actual water environment.

Toward commercial applications of LED and laser-induced fluorescence techniques for food identity, quality, and safety monitoring: A review.

The assessment of food safety and quality is a matter of paramount importance, especially considering the challenges posed by climate change. Convenient, eco-friendly, and non-destructive techniques have attracted extensive attention in the food industry because they can retain food safety and quality. Fluorescence radiation, the process by which fluorophore emits light upon the absorption of ultraviolet or visible light, offers the advantages of high sensitivity and selectivity. The use of excitation-emission matrix (EEM) has been extensively explored in the food industry, but on-site detection of EEMs remain a challenge. To address this limitation, laser-induced fluorescence (LIF) and light emitting diode-induced fluorescence (LED-IF) have been implemented in many cases to facilitate the transition of fluorescence measurements from the laboratory to commercial applications. This review provides an overview of the application of commercially available LIF/LED-IF devices for non-destructive food measurement and recent studies that focus on the development of LIF/LED-IF devices for commercial applications. These studies were categorized into two stages: the preliminary exploration stage, which emphasizes the selection of an appropriate excitation wavelength based on the combination of EEM and chemometrics, and the pre-application stage, where experiments were conducted on scouting with specific excitation wavelength. Although commercially available devices have emerged in many research fields, only a limited number have been reported for use in the food industry. Future studies should focus on enhancing the diversity of test samples and parameters that can be measured by a single device, exploring the application of LIF techniques for detecting low-concentration substances in food, investigating more quantitative approaches, and developing embedded computing devices.

Extensive jejunal injury is repaired by migration and transdifferentiation of ileal enterocytes in zebrafish.

A major cause of intestinal failure (IF) is intestinal epithelium necrosis and massive loss of enterocytes, especially in the jejunum, the major intestinal segment in charge of nutrient absorption. However, mechanisms underlying jejunal epithelial regeneration after extensive loss of enterocytes remain elusive. Here, we apply a genetic ablation system to induce extensive damage to jejunal enterocytes in zebrafish, mimicking the jejunal epithelium necrosis that causes IF. In response to injury, proliferation and filopodia/lamellipodia drive anterior migration of the ileal enterocytes into the injured jejunum. The migrated fabp6+ ileal enterocytes transdifferentiate into fabp2+ jejunal enterocytes to fulfill the regeneration, consisting of dedifferentiation to precursor status followed by redifferentiation. The dedifferentiation is activated by the IL1ß-NFκB axis, whose agonist promotes regeneration. Extensive jejunal epithelial damage is repaired by the migration and transdifferentiation of ileal enterocytes, revealing an intersegmental migration mechanism of intestinal regeneration and providing potential therapeutic targets for IF caused by jejunal epithelium necrosis.

Nondestructive detection of nutritional parameters of pork based on NIR hyperspectral imaging technique.

Nondestructive detection of the nutritional parameters of pork is of great importance. This study aimed to investigate the feasibility of applying hyperspectral image technology to detect the nutrient content and distribution of pork nondestructively. Hyperspectral cubes of 100 pork samples were collected using a line-scan hyperspectral system, the effects of different preprocessing methods on the modeling effects were compared and analyzed, the feature wavelengths of fat and protein were extracted, and the full-wavelength model was optimized using the regressor chains (RC) algorithm. Finally, pork's fat, protein, and energy value distributions were visualized using the best prediction model. The results showed that standard normal variate was more effective than other preprocessing methods, the feature wavelengths extracted by the competitive adaptive reweighted sampling algorithm had better prediction performance, and the protein model prediction performance was optimized after using the RC algorithm. The best prediction models were developed, with the correlation coefficient of prediction (RP) = 0.929, the root mean square error in prediction (RMSEP) = 0.699% and residual prediction deviation (RPD) = 2.669 for fat, and RP = 0.934, RMSEP = 0.603% and RPD = 2.586 for protein. The pseudo-color maps were helpful for the analysis of nutrient distribution in pork. Hyperspectral image technology can be a fast, nondestructive, and accurate tool for quantifying the composition and assessing the distribution of nutrients in pork.

Differences in risk factors and outcome after acute stroke in patients with tandem occlusion and those with isolated intracranial occlusion after endovascular treatment.

OBJECTIVE: This study aimed to compare the clinical features, treatment, and clinical outcome of patients with tandem occlusion and isolated intracranial occlusion through endovascular treatment (EVT). METHODS: Patients with acute cerebral infarction who received EVT in two stroke centers were retrospectively included. According to MRI or CTA results, the patients were divided into tandem occlusion group or isolated intracranial occlusion group. The baseline data, etiological classification, treatment, post-stroke complications, image features, and clinical outcome were compared. Multivariate logistic regression analysis was used to evaluate the related factors affecting the prognosis of patients with EVT. RESULTS: Among 161 patients with acute cerebral infarction, there were 33 cases (20.5%) in the tandem occlusion group and 128 cases (79.5%) in the isolated intracranial occlusion group. Compared with isolated intracranial occlusion, the patients with tandem occlusion had higher rates of large artery atherosclerosis (P = 0.028), symptomatic intracerebral hemorrhage (sICH) (P = 0.023), bilateral infarction (P = 0.042), and longer time for endovascular procedure (P = 0.026). There was no significant statistical difference in 90-day mRS score between the two groups (P = 0.060). Multivariate logistic regression identified the following independent predictors of poor functional outcome: older age, high fasting blood glucose, infarction area > 1/3, and hemorrhagic transformation. CONCLUSIONS: Compared with isolated intracranial occlusion, there was not a worse prognosis among patients with tandem occlusion who received EVT.

The Role of MbEGS1 and MbEGS2 in Methyleugenol Biosynthesis by Melaleuca bracteata.

Many aromatic plant volatile compounds contain methyleugenol, which is an attractant for insect pollination and has antibacterial, antioxidant, and other properties. The essential oil of Melaleuca bracteata leaves contains 90.46% methyleugenol, which is an ideal material for studying the biosynthetic pathway of methyleugenol. Eugenol synthase (EGS) is one of the key enzymes involved in the synthesis of methyleugenol. We recently reported two eugenol synthase genes (MbEGS1 and MbEGS2) present in M. bracteata, where MbEGS1 and MbEGS2 were mainly expressed in flowers, followed by leaves, and had the lowest expression levels in stems. In this study, the functions of MbEGS1 and MbEGS2 in the biosynthesis of methyleugenol were investigated using transient gene expression technology and virus-induced gene silencing (VIGS) technology in M. bracteata. Here, in the MbEGSs genes overexpression group, the transcription levels of the MbEGS1 gene and MbEGS2 gene were increased 13.46 times and 12.47 times, respectively, while the methyleugenol levels increased 18.68% and 16.48%. We further verified the function of the MbEGSs genes by using VIGS, as the transcript levels of the MbEGS1 and MbEGS2 genes were downregulated by 79.48% and 90.35%, respectively, and the methyleugenol content in M. bracteata decreased by 28.04% and 19.45%, respectively. The results indicated that the MbEGS1 and MbEGS2 genes were involved in the biosynthesis of methyleugenol, and the transcript levels of the MbEGS1 and MbEGS2 genes correlated with the methyleugenol content in M. bracteata.

Evolutionary Analysis of the Melon (Cucumis melo L.) GH3 Gene Family and Identification of GH3 Genes Related to Fruit Growth and Development.

The indole-3-acetic acid (IAA) auxin is an important endogenous hormone that plays a key role in the regulation of plant growth and development. In recent years, with the progression of auxin-related research, the function of the Gretchen Hagen 3 (GH3) gene has become a prominent research topic. However, studies focusing on the characteristics and functions of melon GH3 family genes are still lacking. This study presents a systematic identification of melon GH3 gene family members based on genomic data. The evolution of melon GH3 family genes was systematically analyzed by means of bioinformatics, and the expression patterns of the GH3 family genes in different melon tissues during different fruit developmental stages and with various levels of 1-naphthaleneacetic acid (NAA) induction were analyzed with transcriptomics and RT-qPCR. The melon genome contains 10 GH3 genes distributed across seven chromosomes, and most of these genes are expressed in the plasma membrane. According to evolutionary analysis and the number of GH3 family genes, these genes can be divided into three subgroups, and they have been conserved throughout the evolution of melon. The melon GH3 gene has a wide range of expression patterns across distinct tissue types, with expression generally being higher in flowers and fruit. Through promoter analysis, we found that most cis-acting elements contained light- and IAA-responsive elements. Based on the RNA-seq and RT-qPCR analyses, it can be speculated that CmGH3-5, CmGH3-6 and CmGH3-7 may be involved in the process of melon fruit development. In conclusion, our findings suggest that the GH3 gene family plays an important role in the development of melon fruit. This study provides an important theoretical basis for further research on the function of the GH3 gene family and the molecular mechanism underlying the development of melon fruit.

Generalizable Descriptors of Highly Sensitive Detection of As(III) over Transition-Metal Single Atoms: A Combined Density Function Theory and Gradient Boosting Regression Approach.

Traditional nanomodified electrodes have made great achievements in electrochemical stripping voltammetry of sensing materials for As(III) detection. Moreover, the intermediate states are complicated to probe because of the ultrashort lifetime and complex reaction conditions of the electron transfer process in electroanalysis, which seriously hinder the identification of the actual active site. Herein, the intrinsic interaction of highly sensitive analytical behavior of nanomaterials is elucidated from the perspective of electronic structure through density functional theory (DFT) and gradient boosting regression (GBR). It is revealed that the atomic radius, d-band center (εd), and the largest coordinative TM-N bond length play a crucial role in regulating the arsenic reduction reaction (ARR) performance by the established ARR process for 27 sets of transition-metal single atoms supported on N-doped graphene. Furthermore, the database composed of filtered intrinsic electronic structural properties and the calculated descriptors of the central metal atom in TM-N4-Gra were also successfully extended to oxygen evolution reaction (OER) systems, which effectively verified the reliability of the whole approach. Generally, a multistep workflow is developed through GBR models combined with DFT for valid screening of sensing materials, which will effectively upgrade the traditional trial-and-error mode for electrochemical interface designing.

A Simple Grading Scale for Predicting Symptomatic Intracranial Hemorrhage after Mechanical Thrombectomy.

INTRODUCTION: Hemorrhagic transformation, especially symptomatic intracranial hemorrhage (sICH), is a common complication after mechanical embolectomy. This study explored a grading scale based on clinical and radiological parameters to predict sICH after mechanical embolectomy. METHODS: Demographic and clinical data were retrospectively collected from patients with acute ischemic stroke treated with mechanical embolectomy at West China Hospital. Clinical and radiological factors associated with sICH were identified and used to develop the "STBA" grading scale. This score was then validated using data from an independent sample at the First Affiliated Hospital of Kunming Medical University. RESULTS: We analyzed 268 patients with acute ischemic stroke who were treated with mechanical embolectomy at West China Hospital, of whom 30 (11.2%) had sICH. Patients were rated on an "STBA" score ranging from 0 to 6 based on whether systolic blood pressure was ≥145 mm Hg at admission (yes = 2 points; no = 0 points), time from acute ischemic stroke until groin puncture was ≥300 min (yes = 1; no = 0), blood glucose was ≥8.8 mmol/L (yes = 1; no = 0), and the Alberta Stroke Program Early Computed Tomography score at admission was 0-5 (2 points), 6-7 (1 point), or 8-10 (0 points). The STBA score showed good discrimination in the derivation sample (area under the receiver operating characteristic curve = 0.858) and in the validation sample (area = 0.814). CONCLUSIONS: The STBA score may be a reliable clinical scoring system to predict sICH in acute ischemic stroke patients treated with mechanical embolectomy.

Occurrence, vertical distribution and transport of organic amine pesticides in the seawater from the East China Sea and the South China Sea.

Organic amine pesticides (OAPs) are widely used as insecticides, fungicides and herbicides in agricultural production. China is a large agricultural country, and the sprayed pesticides may impact the fragile marine environment through surface runoff. This study revealed the pollution characteristics of thirty-three OAPs in the East China Sea (ECS) and the South China Sea (SCS) and investigated their vertical variations in water columns. The ∑OAPs ranged from below method detection limits to 3.4 ng/ L, with an average value of 0.93 ng/ L. Diphenylamine and beflubutamid were the two most abundant compounds, contributing 64 % and 14 % of the ∑OAPs, respectively. The ∑OAPs in the ECS were significantly (M-W U test, p < 0.01) higher than that in the SCS, and OAPs exhibited different composition profiles. Diphenylamine was the most abundant compound in the ECS, while beflubutamid was dominant in the SCS, which may be related to industrial production (such as rubber synthesis) and agricultural activities. In the water columns, OAPs concentrations were higher in deep layers compared to that in surface seawater, which may be due to weak light and low temperature reducing the degradation of pesticides, indicating the deep ocean is a sink for OAPs. Under the dilution of seawater, the concentrations of OAPs decreased from the Pearl River Estuary to the open sea, and the South China Sea Warm Current also caused the decrease of OAPs from south to north. A preliminary risk assessment indicated that OAPs in the water pose no significant risk to aquatic organisms.

Occurrence, partitioning and transport of perfluoroalkyl acids in gas and particles from the southeast coastal and mountainous areas of China.

Perfluoroalkyl acids (PFAA) in gas and particles were analyzed in southeast coastal and mountainous cities, including Fuzhou, Xiamen, Zhangzhou and Nanping, to study the pollution characteristics, particle size distribution, phase partitioning and atmospheric transport. PFAA ranged from 7.8 to 290 pg m-3 in gaseous phase, 27 - 1200 pg m-3 in particulate phase, and perfluorobutanoic acid (PFBA), perfluorooctanoic acid (PFOA) were main compounds. PFAA had the highest concentration in Nanping with perfluorohexanoic acid (PFHxA) dominant, which could be related to the emission of PFAS from local industrial plants. Perfluorocarboxylic acids (PFCAs) and perfluoroalkyl sulfonic acids (PFSAs) exhibited different particle size distribution characteristics, with PFSAs preferring to distribute on coarse particles, which could be affected by the salt, minerals and organic matter in different particle sizes. The gas - particle partitioning coefficient (KPA) had a line relationship with the fluorinated carbon chain length of PFAA, suggesting that long-chain PFAA tended to exist in particulate phase. The Winter Monsoon could transport to the study area and drive atmospheric PFAS to southern cities. HIGHLIGHTS: • Industrial plants contributed high concentrations of PFAA. • PFSAs tended to present in coarse particles. • Log KPA increased linearly with increasing carbon chain length of PFAA. • Winter Monsoon drove atmospheric PFAA to southern cities.

[Pollution Characteristics of Microplastics in Sediments of Xiamen Bay Beach].

Microplastics widely exist in various environmental media and have become a global environmental problem. To investigate the pollution characteristics, deposition patterns, and influencing factors of microplastics in the sediments of bay beach, five typical beaches were selected in Xiamen Bay. According to the tidal variation, 0-10 cm, 10-20 cm, and 20-30 cm sediment column samples were collected in layers at the high tide line, middle tide line, and low tide line at the same time, and the characteristics of the horizontal and vertical distribution of microplastics in the beach sediments were studied. The results showed that the abundance of microplastics in 45 sediment samples in Xiamen Bay beach ranged from 39 to 260 n·kg-1, with an average abundance of (114±26) n·kg-1. The shapes of microplastics were mainly fibers, fragments, granules, and foams, with fibers making up the largest proportion. The main components were polyethylene terephthalate (PET), cellophane, and polyethylene (PE). The colors of microplastics included transparent, yellow, blue, black, white, etc. The average abundance of microplastics showed a certain pattern depending on the beach location, intertidal zone, and sampling depth. Moreover, the abundance and distribution of microplastics on the beach were affected by various natural and human factors such as waves, tides, shoreline shape, the number of tourists, and the cleaning of marine floating debris. These results aid the understanding of the distribution characteristics and sources of microplastics in beach sediments, provide a basis for the transport of microplastics from land to sea, and provide data support for the collection of sea floating garbage and shoreline garbage.