N6-methyladenosine methylation mediates non-coding RNAs modification in microplastic-induced cardiac injury.

Owing to their potential adverse health effects, global contamination by microplastics (MPs) has attracted increased scientific and societal concerns. However, in vivo studies on MP toxicity, along with its effects and underlying mechanisms, remain limited. We recently found that non-coding RNA (ncRNAs) contribute to MP-mediated vascular toxicity. Moreover, previous studies have identified N6-methyladenosine (m6A) modifications in ncRNAs as influencing factors in cardiovascular disease. However, whether and how m6A modifications in ncRNAs are affected by MP-induced cardiotoxicity remain unknown. Herein, we profiled differentially expressed ncRNAs and their related m6A modification profiles in MP-exposed myocardial tissue using RNA sequencing (RNA-seq) and methylated RNA immunoprecipitation sequencing (MeRIP-seq). First, we observed that MPs accumulated in different organs and upregulated apoptosis in the heart, liver, spleen, and kidney cells. Furthermore, total m6A and METTL3 levels increased in the myocardium after exposure to MPs. RNA-seq results revealed that 392 lncRNAs and 302 circRNAs were differentially expressed in MP-treated mouse myocardium compared to the control group. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes enrichment analyses showed that these altered lncRNAs and circRNAs were closely associated with endocytosis, cellular senescence, and cell cycle signaling pathways, which may cause cardiotoxicity. Furthermore, MeRIP-seq data showed different distributions and abundances of m6A modifications in lncRNAs and circRNAs. Additionally, we identified differentially m6A methylated lncRNAs and circRNAs through conjoint analysis of the two high-throughput sequencing datasets and found that both m6A modifications and the expression of circ-Arfgef2 and lncG3bp2 were upregulated after exposure to MPs. This suggests that MP-induced m6A modifications in ncRNAs are involved in cardiotoxicity. Our findings contribute to a better understanding of MP-induced cardiotoxicity and new molecular targets for treating cardiac injury.

[Odorants Removal and Microbial Characteristics in Treatment of Micro-polluted Source Water with Biological Powdered Activated Carbon-Ultrafiltration Combined Process].

The odorants in simulated micro-polluted source water were removed by the Biological Powdered Activated Carbon-Ultrafiltration (BPAC-UF) combined process, and variations of microorganisms in the combined process were discussed. Compared with the conventional process of coagulation and sedimentation, BPAC-UF combined process had better performance in controlling odorants in micro-polluted source water. The average removal rates of dimethyl trisulfide, 2-methylisoborneol and ß-ionone reached up to 77.51%, 65.86% and 98.43%, respectively. The process was more adaptable to raw water shock load. The carbon tank which had much more microbial biomass than other areas was determined to be the main unit for removing odorants. The biomass changed smoothly in the carbon tank, while the removal of odorants in raw water was stable in the process.

[Distribution, dissemination and removal of antibiotic resistant genes (ARGs) in the aquatic environment].

In recent years, the intensive use of antibiotics induces the development of antibiotic resistant genes (ARGs), which is an increasingly critical problem affecting human health, and the potential toxic effects of the ARGs have drawn great attention all over the world. This review gave an overview of the occurrence, potential sources, fate and ecological risks of ARGs in the environment. What's more, the removal of ARGs by different treatment processes such as sludge digestion, constructed wetland, disinfection and advanced treatments were assessed, and the improving directions of different treatment processes were also pointed out. Additionally, the highlights in need for further research were proposed based on the current pollution status.

[Effect of C/N ratio on nitrite accumulation during denitrification process].

Effect of C/N (COD/NO3(-) -N) ratio on nitrite accumulation during denitrification process was investigated in a sequencing batch reactor (SBR) with acetic sodium as the electron donor. The nitrite accumulation ratio was 45% at a C/N ratio of 3 during operation in SBR with HRT at 6 h. According to the results of batch experiments, Nitrite accumulation ratios were higher at C/N ratios of 2.5 and 3.0, and the values were 47.50% +/- 1.005% and 45.28% +/- 5.469%, respectively. The nitrite specific accumulation rate was (30.17 +/- 1.70) mg x (g x h)(-1) at a C/N ratio of 2.5, and was (29.92 +/- 1.90) mg x (g x h)(-1) at a C/N ratio of 3.0. C/N ratios of 2.5-4.0 did not affect the nitrate reduction rate but obviously affected the nitrite accumulation rate. C/N ratios of 2.5 and 3.0 were favorable for nitrite accumulation, and a C/N ratio > or = 3.5 would lead to decrease in nitrite accumulation (SBR).

Two novel indices for quantitatively characterizing the toxicity interaction between ionic liquid and carbamate pesticides.

Compound contamination and toxicity interaction demand the development of models that have an insight into the combined toxicity of chemicals. Two novel mixture toxicity indices, concentration addition index (CAI) and effect addition index (EAI), were developed to quantitatively characterize the toxicity interaction within four binary mixture systems containing carbamate pesticides and 1-benzyl-3-methylimidazolium tetrafluoroborate (IL). To examine the applicability of CAI and EAI, we compared the indices with the other indices such as the sum of toxic unit (STU), model deviation ratio (MDR), and effect residual ratio (ERR) and isobologram approach. The results showed that CAI and EAI could more clearly and effectively characterize the toxicity interaction within IL-pesticide mixtures than the other four methods. According to CAI and EAI, IL-aldicarb, IL-baygon and IL-methomyl mixture systems displayed clear antagonism at relatively low effect regions, while IL-pirimicarb mixture systems basically exhibited additive action. The most interesting observation is that all five indices (CAI, EAI, MDR, ERR, and STU) are well correlated with the concentration ratio of IL in the mixtures.

Turbiscan Lab ® Expert analysis of the biological demulsification of a water-in-oil emulsion by two biodemulsifiers.

The long-term destabilization process of a water-in-oil emulsion was investigated with two different biodemulsifiers produced under different culture conditions by Alcaligenes sp. S-XJ-1. Biodemulsifier I was obtained by using paraffin as substrate at initial culture pH of 10 and biodemulsifier II was produced with waste frying oils at pH of 7. The former exhibited higher demulsifying ability and interfacial activity than the latter. Bottle test, microscopy and Turbiscan Lab(®) Expert were used to investigate the biological demulsification process. It was found that biodemulsifiers' ability to decrease the interfacial tension played a more important role in demulsification than their ability to decrease the surface tension. Owing to their amphiphilic nature, demulsification process began with the adsorption of the biodemulsifiers onto the water-oil interface. Then the biodemulsifiers reacted with the emulsifiers because of their interfacial activity. As a result, thin liquid film was removed from the surface of dispersed droplets and coalescence occurred. This led to the settling of the dispersed droplets and the clarification of the continuous phase. Turbiscan Lab(®) Expert can be used to evaluate the demulsification efficiency and to analyze the destabilization process of different biodemulsifiers. It is a rapid and accurate method to screen high-efficiency demulsifiers from other bioproducts.

[Study of the removal of Pb2+ from aqueous solution by poly-gamma-glutamic acid coated magnetic nanoparticles].

In this study, a novel low cost magnetic adsorbent material prepared by poly-gamma-glutamic acid (gamma-PGA) coating Fe3o4 magnetic particles, which was called coated magnetic namoparticles (PG-M) was developed for the removal of Pb2+ from water by Dr. Yasuzawa. The particle size of PG-M was about 120-320 nm, and there was no significant difference in Fe3O4 and PG-M particle size, Fe3O4 was only as the support of PG-M core and did not directly involve in the reaction. The shape of PG-M was irregular cubic structure. The experiments were applied to quantify adsorptive time, pH, competitive ion and organics on the removal effect of Pb2+. The results showed that PG-M was effective in removal of Pb2+; the equilibrium amount of adsorptive was as high as 93.3 mg/g and the optimized condition of pH value for metal ions removal was 7.0, while contact time was about 45 min. The removal efficiency of Pb2+ was not significantly influenced by Na+ while was reduced with the increasing concentration of Ca2+. The removal of Pb2+ was enhanced with the presence of organic matter (humic acid, HA) when the concentration of HA was below 5 mg/L, and decreased when the concentration of HA exceeded 5 mg/L. Langmuir isotherms fitted the experimental data better compared to Freundlich isotherms. Pseudo second order model well described the sorption kinetics of Pb2+. The used PG-M can be desorbed by 0.1 mol/L HCl and became reusable. PG-M is nontoxic and eco-friendly, which have a good prospect in water treatment.

[Oxytetracycline removal in aqueous by two kinds of zeolites with different bore diameter].

5A and 13X, as two kinds of hydrophilic zeolites with different bore diameters, were chosen as adsorption materials for oxytetracycline (OTC) adsorption and desorption in aqueous. The effects of pH value and temperature on OTC adsorption were investigated respectively, and then the adsorption kinetics as well as thermodynamic were calculated to analyze the corresponding adsorption mechanism. The results showed that two zeolites had satisfactory adsorption capacities on OTC and the adsorption processes were well fitted by the single-layer adsorption model. The saturated adsorption were 667 mg/g and 1429 mg/g on 5A and 13X respectively (298K, pH = 7.0). The adsorption property of OTC on 13X was much better than that of 5A at the same temperature. The adsorption kinetics were well described by the secondary kinetic equations and the OTC desorption rates by 5A and 13X were 91% and 95% individually in the desorption processes. The maximum adsorption capacities of two zeolites were in neutral solutions. And the thermodynamic calculations showed that the adsorption of OTC on two zeolites was spontaneous endothermic reaction with the chemical hydrogen bond as dominant.

Potential enzyme toxicity of perfluorooctanoic acid.

Using equilibrium dialysis, isothermal titration calorimetry (ITC) and circular dichroism (CD), the interactions of perfluorooctanoic acid (PFOA) and lysozyme were investigated under normal human physiological conditions, i.e., at pH 4.40, 6.00 and 7.40 at 37 degrees C in 0.15 M electrolyte. A simple and rapid spectrophotometric method was developed for determining PFOA concentrations. Interactions between PFOA and lysozyme were found to result from non-specific non-covalent bonds-F/N and F/O affinity, ion-pair attraction, hydrogen bond, hydrophobic interaction and van der Waals force-and were affected by chemical adsorption to monolayers. The results indicated that binding of PFOA altered the secondary structure and activity of lysozyme. This work provides a useful experimental strategy for research into the enzyme toxicity of organic chemicals, e.g., food additives and organic contaminants, and it may help to elucidate the molecular toxicology of human health risks.

[Arsenite removal performance by modified GAC].

Two kinds of Fe-Mn oxide impregnated GAC (FM-GAC-1, FM-GAC-2) were prepared and their arsenite removal performance were studied. The adsorption isotherm and reaction kinetic models of arsenite on the two kinds of modified GAC and influence of solution pH, temperature and co-exist anions were investigated in the study. The results showed FM-GAC-1 and FM-GAC-2 can adsorb arsenite effectively, the adsorption capacities were 32.37 mg x g(-1) and 26.67 mg x g(-1) respectively. The adsorb velocity could be predicted well by applying pseudosecond order rate equation and the chemistry reaction process was the limitation of the reaction for both modified GAC. The lower solution pH was benefit to the removal of arsenite. The adsorption capacity of FM-GAC-1 and FM-GAC-2 decreased with temperature increasing. The adsorption processes were spontaneous heat-discharge processes. Some co-exist anions can influence arsenite adsorption on modified GAC when their concentration were 200 times of arsenite. It was found that SiO3(2-), PO3(2-), NO3(-) had a significant negative influence on arsenite removal by FM-GAC-1 and SiO3(2-), CO3(2-) can markedly decrease arsenite adsorption on FM-GAC-2. As a whole, FM-GAC-1 had better arsenite removal performance than FM-GAC-2.

[Effect of coagulation on preventing membrane from fouling].

In this experiment, the effects on improve of flux and prevention of membrane from fouling is studied. The results demonstrate that after backwashing, the flux was completely recovered by addition of 4mg/L and l0mg/L(as Al), while the flux was only 40% of initial flux without coagulation pretreatment. It is also observed that whether or not prevention of fouling by coagulation are depended on the characteristics of cake layer formed on membrane surface during membrane filtration. In the presence of filtration of coagulation floc suspension, coagulation can form cake layer on membrane surface, thus prevent membrane from fouling effectively, while in the presence of filtration of supernatant, fouling are occurred due to cake layer comprising small, neutral, hydrophilic compounds, which can not remove by backwash.