Insights into the combined toxicity and mechanisms of BDE-47 and PFOA in marine blue mussel: An integrated study at the physiochemical and molecular levels.

The coexistence of multiple emerging contaminants imposes a substantial burden on the ecophysiological functions in organisms. The combined toxicity and underlying mechanism requires in-depth understanding. Here, marine blue mussel (Mytilus galloprovincialis L.) was selected and exposed to 2,2',4,4'-tetrabromodiphenyl ether (BDE-47) and perfluorooctanoic acid (PFOA) individually and in combination at environmental related concentrations to elucidate differences in stress responses and potential toxicological mechanisms. Characterization and comparison of accumulation, biomarkers, histopathology, transcriptomics and metabolomics were performed. Co-exposure resulted in differential accumulation patterns, exacerbated histopathological alterations, and different responses in oxidative stress and biomarkers for xenobiotic transportation. Moreover, the identified differentially expressed genes (DEGs) and differential metabolites (DEMs) in mussels were found to be annotated to different metabolic pathways. Correlation analyses further indicated that DEGs and DEMs were significantly correlated with the above biomarkers. BDE-47 and PFOA altered the genes and metabolites related to amino acid metabolism, energy and purine metabolism, ABC transporters, and glutathione metabolism to varying degrees, subsequently inducing accumulation differences and combined toxicity. Furthermore, the present work highlighted the pivotal role of Nrf2-keap1 detoxification pathway in the acclimation of M. galloprovincialis to reactive oxygen species (ROS) stress induced by BDE-47 and PFOA. This study enabled more comprehensive understanding of combined toxic mechanism of multi emerging contaminants pollution.

A novel ZIF-L/PEI thin film nanocomposite membrane for removing perfluoroalkyl substances (PFASs) from water: Enhanced retention and high flux.

Membrane separation technology is widely recognized as an effective method for removing perfluoroalkyl substances (PFASs) in water treatment. ZIF-L, a metal-organic framework (MOF) family characterized by its mat-like cavities and leaf-like morphology, has garnered considerable interest and has been extensively employed in fabricating thin-film nanocomposite (TFN) membranes. In this study, a robust, high-performance TFN membrane to remove PFASs in a nanofiltration (NF) process was created through an interfacial polymerization approach on the surface of polysulfone (PSF), incorporating ZIF-L within the selective layer. The TFN membrane modified by adding 5 wt% ZIF-L (relative to the weight of ethylene imine polymer (PEI)) exhibits 2.3 times higher water flux (up to 47.56 L·m-2·h-1·bar-1) than the pristine thin film composite membrane (20.46 L·m-2·h-1·bar-1), and the rejection for typical PFASs were above 95 % (98.47 % for perfluorooctanesulfonic acid (PFOS) and 95.85 % for perfluorooctanoic acid (PFOA)). The effectiveness of the ZIF-L/PEI TFN membrane in retaining representative PFASs was examined under various conditions, including different pressures, feed concentrations, aqueous environments, and salt ions. Notably, the experiments demonstrated that even after contamination with humic acid (HA), >88 % of the water flux could be restored by washing. Additionally, density functional theory (DFT) calculations were employed to predict the distinct intermolecular interactions between PFASs and ZIF-L as well as PEI. These calculations provide additional insights into the interception mechanism of TFN membranes towards PFASs. Based on this study, TFN membranes incorporating MOF as nanofillers show great potential as an effective method for purifying PFASs from aqueous environments and possess superior environmental sustainability and cost-effectiveness.

Separation of carbohydrates using dynamically adsorbed borate stationary phase for hydrophilic interaction liquid chromatography.

In this work, a chromatographic method for the separation of carbohydrates was proposed. Tris-(hydroxymethyl)-amine (TRIS) functionalized silica-based hydrophilic interaction liquid chromatography (HILIC) stationary was synthesized. The dynamically absorbed borate layer is generated by using borate buffer as a polar modifier due to the complexation of borate with TRIS ligand in the stationary phase. The chromatographic systems were analyzed by the linear solvation energy relationship model. The calculated system constants revealed the enhancement of anionic exchange by the addition of borate in the mobile phase system. In addition, ligand exchange is critical for the retention and elution order of sugars and sugar alcohols. Carbohydrates displayed prolonged retention with different selectivity profiles relating to their complexation coefficients with borate. Experiment results showed that the effect of borate in this chromatographic system was stable within the range of pH 3-7 and borate concentration of 5-15 mM. This work provides a complementary solution for the separation of carbohydrates. It can also be extended to the separation of glycosides.

Retraction notice to "Autophagy regulates the Wnt/GSK3ß/ß-catenin/cyclin D1 pathway in mesenchymal stem cells (MSCs) exposed to titanium dioxide nanoparticles (TiO2NPs)" [Toxicol. Rep. 7C (2020) 1216-1222].

[This retracts the article DOI: 10.1016/j.toxrep.2020.08.020.].

The Dually Negative Effect of Industrial Polluting Enterprises on China's Air Pollution: A Provincial Panel Data Analysis Based on Environmental Regulation Theory.

Although the Chinese government has promulgated a series of policies to mitigate air pollution, the air quality in a number of Chinese cities still has the potential to be improved. As the major source of air pollution, enterprises in the industrial and energy sectors are the most difficult to regulate in terms of polluting emissions. This paper aims to investigate what factors influence the intensity of environmental regulations on polluting enterprises based on environmental regulation theory and an empirical test. Firstly, this article builds a theoretic model of optimal regulation supply for local governments in order to examine the relationship between factors influencing the intensity of environmental regulation. Secondly, we use provincial panel data from 2008 to 2015 to test the theoretical hypothesis and use the generalized method of moments (GMM), the two-stage least squares (2SLS) method to address the endogeneity issue. The main finding of the study is that, in regions with a high concentration of polluting enterprises, not only is there more air pollution than in other regions, but the local governments might show partiality towards the polluting enterprises, which could impede the implementation of environmental regulation.

Autophagy regulates the Wnt/GSK3ß/ß-catenin/cyclin D1 pathway in mesenchymal stem cells (MSCs) exposed to titanium dioxide nanoparticles (TiO2NPs).

The application of titanium dioxide nanoparticles (TiO2NPs) is on the increase, and so the number of studies dedicated to describing this material's biological effects. Previous studies have presented results indicating the controversial impact of TiO2NPs on cell fate regarding death and survival. We speculate that this may be due to focusing on each of the subject cells as an isolated individual. In this study, we made a difference by looking at the subject cells as an interrelated population. Specifically, we exposed mesenchymal stem cells (MSCs) to TiO2NPs and observed cell death and stimulation of proliferation among the cell population. Our data shows that the exposure to TiO2NPs initiated autophagy, which led to an increase in extracellular Wnt protein levels and increased Wnt/GSK3ß/ß-catenin/cyclin D1 signalling in the cell population. Autophagy inhibitor repressed the effects of TiO2NPs, which indicates that ß-catenin regulation was dependent on TiO2NPs-induced autophagy. The inhibition of ß-catenin resulted in dysregulation of cyclin D1 protein expression level. In conclusion, following exposure to TiO2NPs, MSCs undergo autophagy, which induces cell proliferation among the cell population by upregulation of cyclin D1 through the Wnt/GSK3ß/ß-catenin pathway.

Development and in vivo evaluation of baicalin-loaded W/O nanoemulsion for lymphatic absorption.

Background: Lymphatic formations that effectively eradicate the virus in the lymphatic system will be therapeutically advantagous in hepatitis B virus (HBV) infection. Lipid-based formulation is often used to deliver drug via the lymphatic system. Baicalin nanoemulsion may be a promising drug delivery system for improved treatment of HBV infection. Objective: This study aimed to prepare, characterize, and evaluate a lipid-based nanoemulsion containing baicalin for lymphatic system absorption. Method: The presence of a nanoemulsion region was studied by pseudoternary phase diagrams. The physicochemical properties of a baicalin-loaded nanoemulsion were investigated. The oral bioavailability of the baicalin-loaded nanoemulsion was compared to that of a baicalin suspension. A chylomicron flow blocking model was used to examine the extent of lymphatic uptake. The lymph node distribution of baicalin was measured to investigate the lymphatic transport ability of the nanoemulsion compared to the suspension. Results: Compared to the baicalin suspension, the AUC0-t and Cmax values of the baicalin nanoemulsion were increased by 10.5-fold and 3.12-fold, respectively. Compared with the saline-treated rats that were orally administered the baicalin nanoemulsion, the AUC0-t and Cmax values of the nanoemulsion for the rats pretreated with cycloheximide were reduced from 23.076 ± 1.244 mg/L h to 9.236 ± 0.940 mg/L h and from 3.010 ± 0.119 mg/L to 1.567 ± 0.220 mg/L, respectively. In comparing baicalin in W/O nanoemulsion with suspension, the Cmax value was found to be 11.5-fold higher in the lymph nodes of the rats treated with the nanoemulsion. Conclusion: The results indicated that a baicalin-loaded W/O nanoemulsion may be a promising drug delivery system for the treatment of chronic hepatitis B.

Formulation optimization and the absorption mechanisms of nanoemulsion in improving baicalin oral exposure.

OBJECTIVE: The aim of this study was to optimize baicalin nanoemulsion, clarify the absorption mechanisms of nanoemulsion improving the exposure of baicalin, and assess the potential of employing nanoemulsion as nanosystem for insoluble drugs. SIGNIFICANCE: A novel nanoemulsion formulation was successfully prepared to enhance oral exposure of baicalin. METHODS: Pseudo-ternary phase diagrams were utilized to evaluate nanoemulsion area. Physicochemical properties of optimal nanoemulsion formulation were investigated. The exposure of baicalin from the nanoemulsion was compared with baicalin suspension. The in situ single-pass intestine perfusion (SPIP) method and chylomicron-blocked rat model were used to study the absorption mechanisms of nanoemulsion. RESULTS: Baicalin nanoemulsion was nearly spherical in shape with the average droplet size of 58.43 nm, and the zeta potential was -8.18 ± 1.2 mV. The stability test showed that baicalin nanoemulsion was very stable. Pharmacokinetic study indicated that baicalin nanoemulsion showed 14.56-fold improvement in exposure in comparison to baicalin suspension. The results of SPIP and chylomicron flow blocking study showed that intestinal absorption and lymphatic transport process contributed to its systemic exposure. CONCLUSIONS: Based on the results, optimal nanoemulsion might be promising nanosystems for oral delivery of baicalin to satisfy clinical requirements.