Mitigation of gestational diabetes-induced endothelial dysfunction through FGF21-NRF2 pathway activation involving L-Cystine.

Gestational diabetes mellitus (GDM) disrupts glucolipid metabolism, endangering maternal and fetal health. Despite limited research on its pathogenesis and treatments, we conducted a study using serum samples from GDM-diagnosed pregnant women. We performed metabolic sequencing to identify key small molecule metabolites and explored their molecular interactions with FGF21. We also investigated FGF21's impact on GDM using blood samples from affected women. Our analysis revealed a novel finding: elevated levels of L-Cystine in GDM patients. Furthermore, we observed a positive correlation between L-Cystine and FGF21 levels, and found that L-Cystine induces NRF2 expression via FGF21 for a period of 96 h. Under high glucose (HG) conditions, FGF21 upregulates NRF2 and downstream genes NQO1 and EPHX1 via AKT phosphorylation induced by activation of IRS1, enhancing endothelial function. Additionally, we confirmed that levels of FGF21, L-Cystine, and endothelial function at the third trimester were effectively enhanced through appropriate exercise and diet during pregnancy in GDM patients (GDM + ED). These findings suggest FGF21 as a potential therapeutic agent for GDM, particularly in protecting endothelial cells. Moreover, elevated L-Cystine via appropriate exercise and diet might be a potential strategy to enhance FGF21's efficacy.

Associations between 25 hydroxyvitamin D concentration and spontaneous abortion.

BACKGROUND: Spontaneous abortion is a common complication of pregnancy that can lead to adverse physical and psychological outcomes for women. Vitamin D is reported to be associated with reproductive functions, whereas its casual effects on abortion remains unclear. MATERIALS AND METHODS: In this study, a two-sample Mendelian randomization (MR) analysis was performed to systematically assess the causal relationships between serum 25 hydroxyvitamin D [25(OH)D] concentration and the risk of spontaneous abortion. GWAS summary data of 25(OH)D were used as exposure, and data of spontaneous abortion was considered as outcome. A retrospective study was additionally conducted to verify the MR results. RESULTS: MR estimates showed that a higher 25(OH)D level was potentially associated with decreased risk of spontaneous abortion (IVW, OR = 0.98, 95%CI = 0.90-1.06; MR Egger, OR = 0.94, 95%CI = 0.84-1.05; Weighted median, OR = 0.93, 95%CI = 0.82-1.06; Weighted mode, OR = 0.93, 95%CI = 0.84-1.03), though the P-value was not statistically significant. The retrospective study also produced consistent result of Vitamin D's protective role to spontaneous abortion. The P-value was very close to statistical significance (P = 0.053). CONCLUSIONS: This study reports the potential protective role of serum 25(OH)D concentration to spontaneous abortion, suggesting that increased vitamin D levels may decrease the risk of abortion. Further larger prospective studies and/or even randomized controlled trials are needed to confirm causal relationship between vitamin D and abortion.

Photoinduced EnT-mediated sulfonamidylimination of alkenes and (hetero)arenes with iminophenylacetic acid oxime esters.

A photoinduced EnT-mediated generation of sulfonamidyl radicals has been accomplished using rationally designed iminophenylacetic acid oxime ester reagents under metal-free conditions. This approach offers a mild, regio- and diastereoselective synthesis of N-sulfonyl diamines via diamination of alkenes and (hetero)arenes.

Embryo thermal manipulation enhances mitochondrial function in the skeletal muscle of heat-stressed broilers by regulating transient receptor potential V2 expression.

Heat stress induces mitochondrial dysfunction, thereby impeding skeletal muscle development and significantly impacting the economic efficiency of poultry production. This study aimed to investigate the effects of embryo thermal manipulation (TM, 41.5°C, 65% RH, 3 h/d during 16-18th embryonic age) on the mitochondrial function of the pectoralis major (PM) in broiler chickens exposed to thermoneutral (24 ± 1°C, 60% RH) or cyclic heat stress (35 ± 1°C, 60% RH, 12 h/d) from day 22 to 28, and to explore potential mechanisms involving transient receptor potential V2 (TRPV2). Additionally, in vitro experiments were conducted to assess the regulatory effects of TRPV2 pharmacological activation and inhibition on mitochondrial function in primary myotubes. The results revealed that TM had no discernible effect on the body weight and feed intake of broiler chickens under heat stress conditions (P > 0.05). However, it did delay the increase in rectal temperature and accelerate the decrease in serum T3 levels (P < 0.05). Furthermore, TM promoted the development of PM muscle fibers, significantly increasing myofiber diameter and cross-sectional area (P < 0.05). Under heat stress conditions, TM significantly upregulated the expression of mitochondrial electron transport chain (ETC) genes and TRPV2 in broiler PM muscle (P < 0.05), with a clear positive correlation observed between the two (P < 0.05). In vitro, pharmacological activation of TRPV2 not only increased its own expression but also enhanced mitochondrial ETC genes expression and oxidative phosphorylation function by upregulating intracellular calcium ion levels (P < 0.05). Conversely, TRPV2 inhibition had the opposite effect. Overall, this study underscores the potential of prenatal thermal manipulation in regulating postnatal broiler skeletal muscle development and mitochondrial function through the modulation of TRPV2 expression.

Understanding of Endomucin: a Multifaceted Glycoprotein Functionality in Vascular Inflammatory-Related Diseases, Bone Diseases and Cancers.

Endomucin (MUC14), encoded by EMCN gene, is an O-glycosylated transmembrane mucin that is mainly found in venous endothelial cells (ECs) and highly expressed in type H vessels of bone tissue. Its main biological functions include promoting endothelial generation and migration through the vascular endothelial growth factor (VEGF) signaling pathway and inhibiting the adhesion of inflammatory cells to ECs. In addition, it induces angiogenesis and promotes bone formation. Due to the excellent functions of Endomucin in the above aspects, it provides a new research target for the treatment of vascular inflammatory-related diseases and bone diseases. Based on the current understanding of its function, the research of Endomucin mainly focuses on the above two diseases. As it is known, the progression of cancer is closely related to angiogenesis. Endomucin recently is found to be differentially expressed in a variety of tumors and correlated with survival rate. The biological role of Endomucin in cancer is opaque. This article introduces the research progress of Endomucin in vascular inflammatory-related diseases and bone diseases, discusses its application value and prospect in the treatment, and collects the latest research situation of Endomucin in tumors, to provide meaningful evidence for expanding the research field of Endomucin.

Longevity extension in rats via improved redox homeostasis with high carbohydrate diet intervention from weaning to adulthood: a comprehensive multi-omics study.

Early dietary patterns potentially influence the health status and lifespan throughout adulthood and the entire lifespan. However, dietary behaviors are difficult for everyone to control during adolescence. It is even more important to study the effects of interventions of early dietary patterns on the lifespan under arbitrary feeding conditions. The research involves observing the survival status and lifespan of rats from weaning to adulthood with three different dietary patterns (a high-carbohydrate diet (HC), a high-protein diet (HP), and a high-fat diet (HF)) under ad libitum feeding conditions. The administration of high-carbohydrate diets leads to a significant extension of both median and maximum survival times (P < 0.05) in Wistar rats. Furthermore, it markedly enhanced the spatial memory capacity, mitigated the occurrence of liver and kidney pathological outcomes in elderly rats, and increased the abundance of gut microbiota improving amino acid metabolism. Additionally, feeding rats a high-carbohydrate diet improved glutathione (GSH) synthesis and recycling and activated the expression and upregulation of the lifespan-related proteins Foxo3a/Sirt3 and the key metabolic enzyme GPX-4. The high-carbohydrate diet from weaning to adulthood may potentially extend the lifespan by enhancing rat systemic glutathione synthesis, recycling, and improving the redox state pathway.

Anti-inflammation mechanisms of a homogeneous polysaccharide from Phyllanthus emblica L. on DSS induced colitis mice via the gut microbiota and metabolites alteration.

Phyllanthus emblica L. offers promising therapeutic potential for inflammatory diseases. This study revealed the molecular structure of a homogeneous polysaccharide purified from Phyllanthus emblica L. (PEP-1) and evaluated its anti-inflammatory effects on ulcerative colitis (UC) in mice. In the in vivo experiment, administered in varying dosages to dextran sulfate sodium (DSS)-induced UC models, PEP-1 significantly alleviated colonic symptoms, histological damages and reshaped the gut microbiota. Notably, it adjusted the Firmicutes/Bacteroidetes ratio and reduced pro-inflammatory species, closely aligning with shifts in the fecal metabolites and metabolic pathways such as the metabolism of pyrimidine, beta-alanine, and purine. These findings underscore the potential of PEP-1 as a therapeutic agent for UC, providing insights into the mechanisms through gut microbiota and metabolic modulation.

Consequence of COVID-19 on allergic asthma outcomes: a systematic review and meta-analysis.

Asthma is a common chronic lung disease, and COVID-19 pandemic as a respiratory viral disease led to lung infection and resulted in millions of deaths. So, the impact of COVID-19 on asthma outcomes and the risk of being infected or hospitalized should be clarified. Systematic review and meta-analysis on the outcomes and risk of asthma for people with COVID-19 was done by searching electronic databases between 1 December 2019 and 31 July 2023. A total of 48 studies from 27 countries spread across all continents were included in the review. The prevalence of asthma among COVID-19 patients was 7.9%, and the analysis demonstrated a 16.5% reduction in the risk ratio for acquiring COVID-19 among subjects with asthma compared to those without asthma. There was no statistically significant difference in hospitalization risk, ICU admission risk, and death risk for COVID-19 patients with no asthma compared to those with asthma. The risk of death from COVID-19 was similar between nonasthmatics and asthmatics. The findings indicated that subjects with asthma may be at a lower risk of having infection with COVID-19 compared to those without asthma, but they have a similar risk of hospitalization and mortality.

Signal amplification strategies in photoelectrochemical sensing of carcinoembryonic antigen.

Early detection of cancer markers is critical for cancer diagnosis and cancer therapy since these markers may indicate cancer risk, incidence, and disease prognosis. Carcinoembryonic antigen (CEA) is a type of non-specific and broad-spectrum cancer biomarker commonly utilized for early cancer diagnosis. Moreover, it serves as an essential tool to assess the efficacy of cancer treatment and monitor tumor recurrence as well as metastasis, thus garnering significant attention for precise and sensitive CEA detection. In recent years, photoelectrochemical (PEC) techniques have emerged as prominent methods in CEA detection due to the advantages of PEC, such as simple equipment requirements, cost-effectiveness, high sensitivity, low interference from background signals, and easy of instrument miniaturization. Different signal amplification methods have been reported in PEC sensors for CEA analysis. Based on these, this article reviews PEC sensors based on various signal amplification strategies for detection of CEA during the last five years. The advantages and drawbacks of these sensors were discussed, as well as future challenges.

Exploring the ecological security evaluation of water resources in the Yangtze River Basin under the background of ecological sustainable development.

The Yangtze River (hereafter referred to as the YZR), the largest river in China, is of paramount importance for ensuring water resource security. The Yangtze River Basin (hereafter referred to as the YRB) is one of the most densely populated areas in China, and complex human activities have a significant impact on the ecological security of water resources. Therefore, this paper employs theories related to ecological population evolution and the Driving Force-Pressure-State-Impact-Response (DPSIR) model to construct an indicator system for the ecological security of water resources in the YRB. The report evaluates the ecological security status of water resources in each province of the YRB from 2010 to 2019, clarifies the development trend of its water resource ecological security, and proposes corresponding strategies for regional ecological security and coordinated economic development. According to the results of the ecological population evolution competition model, the overall indicator of the ecological security of water resources in the YRB continues to improve, with the safety level increasing annually. Maintaining sound management of water resources in the YRB is crucial for sustainable socioeconomic development. To further promote the ecological security of water resources in the YRB and the coordinated development of the regional economy, this paper proposes policy suggestions such as promoting the continuous advancement of sustainable development projects, actively adjusting industrial structure, continuously enhancing public environmental awareness, and actively participating in international ecological construction and seeking cooperation among multiple departments.

MiR-135b-5p promotes cetuximab resistance in colorectal cancer by regulating FOXN3.

Despite advances in targeted therapies, primary and acquired resistance make the treatment of colorectal cancer (CRC) a pressing issue to be resolved. According to reports, the development of CRC is linked to miRNA dysregulation. Multiple studies have demonstrated that miR-135b-5p has an aberrant expression level between CRC tissues and adjacent tissues. However, it is unclear whether there is a correlation between miR-135b-5p and cetuximab (CTx) resistance in CRC. Use the GEO database to measure miR-135b-5p expression in CRC. Additionally, RT-qPCR was applied to ascertain the production level of miR-135b-5p in three human CRC cells and NCM460 cells. The capacity of cells to migrate and invade was examined utilizing the wound-healing and transwell assays, while the CCK-8 assay served for evaluating cell viability, as well as colony formation assays for proliferation. The expected target protein of miR-135b-5p in CRC cell cetuximab resistance has been investigated using western blot. Suppression of miR-135b-5p could increase the CTx sensitivity of CTx-resistant CRC cells, as manifested by the attenuation of proliferation, migration, and invasion ability. Mechanistic studies revealed miR-135b-5p regulates the epithelial-to-mesenchymal transition (EMT) process and Wnt/ß-catenin signaling pathway through downgulating FOXN3. In short, knockdowning miR-135b-5p could increase FOXN3 expression in CRC cells, promote the EMT process, and simultaneously activate the Wnt/ß-catenin signaling pathway to elevate CTx resistance in CRC cells.

Neutrophil extracellular traps promote immune escape in hepatocellular carcinoma by up-regulating CD73 through Notch2.

Immune escape is the main reason that immunotherapy is ineffective in hepatocellular carcinoma (HCC). Here, this study illustrates a pathway mediated by neutrophil extracellular traps (NETs) that can promote immune escape of HCC. Mechanistically, we demonstrated that NETs up-regulated CD73 expression through activating Notch2 mediated nuclear factor kappa B (NF-κB) pathway, promoting regulatory T cells (Tregs) infiltration to mediate immune escape of HCC. In addition, we found the similar results in mouse HCC models by hydrodynamic plasmid transfection. The treatment of deoxyribonuclease I (DNase I) could inhibit the action of NETs and improve the therapeutic effect of anti-programmed cell death protein 1 (PD-1). In summary, our results revealed that targeting of NETs was a promising treatment to improve the therapeutic effect of anti-PD-1.

Release of perfluoroalkyl acids from sediments under the effects of the discharge ratio and flow flux at a Y-shaped confluence.

The sediments in riverine environments contain notably high concentrations of perfluoroalkyl acids (PFAAs), which may be released into the water body under different hydrodynamic forces, such as those occurring at Y-shaped confluences. The release of PFAAs may pose a significant risk to the surrounding aquatic ecosystems. However, our understanding of the release and transport of PFAAs from sediments at Y-shaped confluences remains unclear. Thus, in this study, we performed a series of flume experiments to explore the effects of discharge ratio and total flow flux on the release and redistribution of PFAAs. The results indicated that these two parameters significantly affected the hydrodynamic features of confluences and the water physicochemical parameters. PFAA concentrations in the dissolved phase and suspended particulate matter (SPM) rose significantly as the discharge ratio and total flow flux increased. The dissolved phase was the predominant loading form of PFAAs, with short-chain PFAAs being the main kind, while long-chain PFAAs were dominant in the SPM. The spatial distribution pattern of PFAAs in sediments at the confluence exhibited a high degree of correspondence with hydrodynamic zones. The separation zone and maximum velocity zone were consistent with sediment regions with low and high capacities to release PFAAs, respectively. The patterns of variation in PFAA distribution were comparable to those observed in hydrodynamic zones as the discharge ratio and total flow flux varied. Furthermore, these two parameters altered the partitioning behaviors of PFAAs; specifically, the PFAAs in sediments tended to be released into the pore-water, while the liberated PFAAs tended to attach to SPM. Linear regression and correlation analyses suggested that the stream-wise and vertical flow velocity components near the sediment-water interface were the primary contributors to sediment suspension and PFAA exchange between the water column and pore-water. These findings will help us to understand the patterns of PFAA release in sediments at Y-shaped confluences and assist in the management of PFAA-contaminated sediments at these locations.

AGEs induce MMP-9 promoter demethylation through the GADD45α-mediated BER pathway to promote breast cancer metastasis in patients with diabetes.

Scientific evidence has linked diabetes to a higher incidence and increased aggressiveness of breast cancer; however, mechanistic studies of the numerous regulators involved in this process are insufficiently thorough. Advanced glycation end products (AGEs) play an important role in the chronic complications of diabetes, but the mechanisms of AGEs in breast cancer are largely unexplored. In this study, we first demonstrate that high AGEs levels in breast cancer tissues are associated with the diabetic state and poor patient outcomes. Furthermore, AGEs interact with the receptor for AGEs (RAGE) to promote breast cancer cell migration and invasion. Mechanistically, based on RNA sequencing (RNA-seq) analysis, we reveal that growth arrest and DNA damage gene 45α (GADD45α) is a vital protein upregulated by AGEs through a P53-dependent pathway. Next, GADD45α recruits thymine DNA glycosylase (TDG) for base excision repair to form the demethylation complex at the promoter region of MMP-9 and enhance MMP-9 transactivation through DNA demethylation. Overall, our results indicate a critical regulatory role of AGEs in patients with breast cancer and diabetes and reveal a novel mechanism of epigenetic modification in promoting breast cancer metastasis.

Effects of Ambient Noise Isolation on Illness Severity and Mental Health Among Hospitalized Children with Asthma: Retrospective Study.

OBJECTIVE: This study investigated the effects of ambient noise isolation on disease severity and mental health among hospitalized children with asthma. METHODS: A retrospective analysis was conducted on the clinical data of 187 hospitalized children with asthma admitted from May 2021 to May 2023. Among them, 92 cases were categorized in the control group (conventional management) and 95 in the observation group (environmental noise isolation). Ambient noise level, disease severity, mental health, and sleep quality were observed and compared between the two groups. RESULTS: Weekly time, the noise value of the observation group was lower than that of the control group (P < 0.05). Before the management, modified Tal scoring system, cough symptom score, and Spence Children's Anxiety Scale-Short Version (SCAS-S) were recorded. SCAS-S and Sleep Disturbance Scale for Children (SDSC) had no significant difference (P > 0.05). Weekly time, no differences in the score of social fear dimension of SCAS-S, score of excessive sweating dimension of SDSC, Tal score, and cough symptom score were found between the observation and control groups (P > 0.05). The scores of other dimensions of SCAS-S and SDSC were lower in the observation group than those in the control group (P < 0.05). CONCLUSIONS: Environmental noise isolation for hospitalized children with asthma can effectively improve their mental health and sleep status, but this strategy cannot improve their disease.

Identification of therapy-induced clonal evolution and resistance pathways in minimal residual clones in multiple myeloma through single-cell sequencing.

PURPOSE: In multiple myeloma (MM), therapy-induced clonal evolution is associated with treatment resistance and is one of the most important hindrances toward a cure for MM. To further understand the molecular mechanisms controlling the clonal evolution of MM, we applied single-cell RNA-sequencing (scRNA-seq) to paired diagnostic and post-treatment bone marrow (BM) samples. EXPERIMENTAL DESIGN: scRNA-seq was performed on 38 BM samples from patients with monoclonal gammopathy of undetermined significance (MGUS) (n = 1), MM patients at diagnosis (n = 19), MM post-treatment (n = 17), and one healthy donor. The single-cell transcriptome data of malignant plasma cells and the surrounding immune microenvironment were analyzed. RESULTS: Profiling by scRNA-seq data revealed three primary trajectories of transcriptional evolution after treatment: clonal elimination in patients with undetectable minimal residual disease (MRD-), as well as clonal stabilization and clonal selection in detectable MRD (MRD+) patients. We noted a metabolic shift towards fatty acid oxidation in cycling-resistant plasma cells (PCs), while selective PCs favored the NF-κB pathway. Intriguingly, when comparing the genetic and transcriptional dynamics, we found a significant correlation between genetic and non-genetic factors in driving the clonal evolution. Furthermore, we identified variations in cellular interactions between malignant plasma cells and the tumor microenvironment (TME). Selective PCs showed the most robust cellular interactions with the TME. CONCLUSIONS: These data suggest that MM cells could rapidly adapt to induction treatment through transcriptional adaptation, metabolic adaptation, and specialized immune evasion. Targeting therapy-induced resistance mechanisms may help to avert refractory disease in multiple myeloma.

The Neurocomputational Mechanism Underlying Decision-Making on Unfairness to Self and Others.

Fairness is a fundamental value in human societies, with individuals concerned about unfairness both to themselves and to others. Nevertheless, an enduring debate focuses on whether self-unfairness and other-unfairness elicit shared or distinct neuropsychological processes. To address this, we combined a three-person ultimatum game with computational modeling and advanced neuroimaging analysis techniques to unravel the behavioral, cognitive, and neural patterns underlying unfairness to self and others. Our behavioral and computational results reveal a heightened concern among participants for self-unfairness over other-unfairness. Moreover, self-unfairness consistently activates brain regions such as the anterior insula, dorsal anterior cingulate cortex, and dorsolateral prefrontal cortex, spanning various spatial scales that encompass univariate activation, local multivariate patterns, and whole-brain multivariate patterns. These regions are well-established in their association with emotional and cognitive processes relevant to fairness-based decision-making. Conversely, other-unfairness primarily engages the middle occipital gyrus. Collectively, our findings robustly support distinct neurocomputational signatures between self-unfairness and other-unfairness.

Sepsis caused by Phytobacter diazotrophicus complicated with galactosemia type 1 in China: a case report.

BACKGROUND: Phytobacter diazotrophicus (P. diazotrophicus) is an opportunistic pathogen that causes nosocomial outbreaks and sepsis. However, there are no reports of P. diazotrophicus isolated from human blood in China. CASE PRESENTATION: A 27-day-old female infant was admitted to our hospital with fever and high bilirubin levels. The clinical features included jaundice, abnormal coagulation, cholestasis, fever, convulsions, weak muscle tension, sucking weakness, ascites, abnormal tyrosine metabolism, cerebral oedema, abnormal liver function, clavicle fracture, and haemolytic anaemia. The strain isolated from the patient's blood was identified as P. diazotrophicus by whole-genome sequencing (WGS). Galactosemia type 1 (GALAC1) was diagnosed using whole-exome sequencing (WES). Based on drug sensitivity results, 10 days of anti-infective treatment with meropenem combined with lactose-free milk powder improved symptoms. CONCLUSION: P. diazotrophicus was successfully identified in a patient with neonatal sepsis combined with galactosemia. Galactosemia may be an important factor in neonatal sepsis. This case further expands our understanding of the clinical characteristics of GALAC1.

Comparison of high-flow nasal cannula with conventional oxygen therapy for preventing postoperative hypoxemia in patients with lung resection surgery: a systematic review and meta-analysis.

Background: The efficacy of high-flow nasal cannula (HFNC) in patients extubated after lung resection surgery remains inconclusive. Our objective was to execute a meticulous systematic meta-analysis to accurately assess the advantages of HFNC compared to conventional oxygen therapy (COT) for patients extubated after lung resection surgery, by examining postoperative hypoxemia and other patient-focused outcomes. Methods: We searched PubMed, Embase, the Cochrane Library, Web of Science and Scopus to identify randomized controlled trials (RCTs) from inception to July 2023. We employed the revised Cochrane risk of bias (RoB) tool (2.0) to evaluate the RoB of the included studies, and the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) method to ascertain the certainty of the pooled effect estimates. The primary outcome was the incidence of postoperative hypoxemia. Results: Five RCTs (n=564) were included in the ultimate analysis. Utilizing HFNC rather than COT did not reduce the risk of postoperative hypoxemia [relative risk (RR), 0.67; 95% confidence interval (CI): 0.30-1.49; low certainty]. Compared to COT, HFNC may significantly enhance oxygenation index within first 12 hours after extubation in patients with lung resection. There were no significant differences in reintubation rate (RR, 0.25; 95% CI: 0.04-1.54; high certainty), escalation of respiratory support (RR, 0.35; 95% CI: 0.11-1.08; high certainty), change in partial pressure of carbon dioxide (PaCO2) within first 24 hours after extubation, hospital length of stay [mean difference (MD), -0.19; 95% CI: -0.44 to 0.06; moderate certainty], and intensive care unit (ICU) length of stay (MD, 0.02; 95% CI: -0.16 to 0.19; high certainty). Conclusions: Our meta-analysis suggests that preemptive use of HFNC, instead of COT, in extubated patients following lung resection surgery may not significantly impact postoperative hypoxemia incidence, reintubation rate, escalation of respiratory support, postoperative PaCO2 difference, hospital and ICU length of stay. However, HFNC may significantly enhance the oxygenation index within the first 12 hours post-extubation following lung resection surgery. To verify the effect of HFNC on this population, additional large-scale, multicenter studies are essential.

Effects of long-chained perfluoroalkyl acids (PFAAs) on the uptake and bioaccumulation of short-chained PFAAs in two free-floating macrophytes: Eichhornia crassipes and Ceratophyllum demersum.

Short-chained perfluoroalkyl acids (PFAAs, CnF2n+1-R, n ≤ 6) have merged as global concerns due to their extensive application and considerable toxicity. However, long-chained PFAAs (n ≥ 7) featured with high persistence are still ubiquitously observed in aquatic environment. To understand the uptake behavior of short-chained PFAAs in aquatic macrophytes, the uptake kinetics, bioconcentration, and translocation of short-chained PFAAs (3 ≤n ≤ 6) in two typical free-floating macrophytes (Eichhornia crassipes and Ceratophyllum demersum) were investigated in the treatments with and without long-chained PFAAs (7 ≤n ≤ 11). Results showed that short-chained PFAAs can be readily accumulated in both E. crassipes and C. demersum, and the uptake of short-chained PFAAs fit the two-compartment kinetic model well (p < 0.05). In the treatments with long-chained PFAAs, significant concentration decreases of all concerned short-chained PFAAs in E. crassipes and PFAAs with n ≤ 5 in C. demersum were observed. Long-chained PFAAs could hinder the uptake rates, bioconcentration factors, and translocation factors of most short-chained PFAAs in free-floating macrophytes (p < 0.01). Significant correlations between bioconcentration factors and perfluoroalkyl chain length were only observed when long-chained PFAAs were considered (p < 0.01). Our results underlined that the effects of long-chained PFAAs should be taken into consideration in understanding the uptake and bioaccumulation behaviors of short-chained PFAAs.