Bridge-oxygen bonding modulates Ru single atoms for peroxymonosulfate activation: Importance of high-valent Ru species and 1O2.

The application of single-atom catalysts (SACs) to advanced oxidation processes (AOPs) based on peroxymonosulfate (PMS) has attracted considerable attention. However, the catalytic pathways and mechanisms underlying these processes remain unclear. In this study, NiFe-LDH was synthesized and single Ru atoms were stably loaded onto it by forming Ru-O-M (M=Ni or Fe) bonds (Ru@NiFe-LDH). This was demonstrated using high-angle annular dark-field scanning TEM (HAADF-STEM) and X-ray absorption fine structure spectra (XANES). The Ru@NiFe-LDH/PMS system showed a high catalytic reactivity (100 % sulfamethoxazole degradation in only 30 min), high stability (97 % reactivity was maintained after continuous operation for 400 min), and wide pH suitability (working pH range 3-11) for AOPs. The crucial roles of the high-valent species (Ru(V) = O) and 1O2 in this reaction were verified. Density functional theory (DFT) calculations revealed that electron transfer produced a positively charged Ru. This enhances the adsorption of negatively charged PMS anions onto the Ru monoatomic sites, thereby, causing the formation of Ru-PMS* complexes. This study implies that the structure-function relationship between organic compounds and SACs plays a significant role in PMS-based AOPs, and provides a comprehensive mechanism for the role of high-valent species in heterogeneous Fenton-like systems.

Isolation and application of Bacillus thuringiensis LZX01: Efficient membrane biofouling mitigation function and anti-toxicity potential.

Significant progress has been made in mitigating membrane biofouling by microbial quorum quenching (QQ). More efficient and survivable QQ strains need to be discovered. A new strain named Bacillus thuringiensis LZX01 was isolated in this study using a low carbon source concentration "starving" method from a membrane bioreactor (MBR). LZX01 secreted intracellular lactonase to enable QQ behavior and was capable of degrading 90 % of C8-HSL (200 ng/mL) within 30 min, which effectively delayed biofouling by inhibiting the growth of bacteria associated with biofouling and improving the hydrophilicity of bound extracellular polymeric substances. As a result, the membrane biofouling rate of MBR adding LZX01 was four times slower than that of the control MBR. Importantly, LZX01 maintains its QQ activity even in environments contaminated with typical toxic pollutants. Therefore, with high efficiency, toxicity resistance, and easy culture, LZX01 holds great potential and significant promise for biofouling control applications.

TIM-3 regulates the proliferation by BDNF-mediated PI3K/AKT axis in the process of endometriosis.

BACKGROUND: T cell immunoglobulin and mucin domain-containing molecule-3 (TIM-3) initially discovered on the surface of Th1 cells, negatively regulates immune responses and mediates apoptosis of Th1 cells. An increasing number of studies have since shown that TIM-3 is crucial in the genesis and development of immune diseases, cancers, and chronic infectious illnesses. However, the effect of TIM-3 on endometriosis is still unknown. METHODS: Quantitative real-time polymerase chain reaction, western blotting, and immunohistochemistry were used to measure TIM-3 levels in endometriosis. Cell Counting Kit-8, 5-ethynyl-2'-deoxyuridine, colony-forming, Transwell® migration, Matrigel® invasion, and flow cytometry assays were used to explore the function of TIM-3 in vitro, and xenograft experiments in nude mice were used to assess its role in vivo. According to the RNA seq, brain-derived neurotrophic factor (BDNF) was screened. The involvement of specific proliferation-related signaling molecules was determined by transfecting a plasmid and adding an inhibitor in vivo and in vitro. RESULTS: TIM-3 mRNA and protein expression levels were significantly higher in eutopic and ectopic endometrial tissues than in normal endometrial tissues. By examining the effects of TIM-3 overexpression and knockdown on cell proliferation, migration, and invasion in vitro, and lesions formation in vivo, we found that the expression of TIM-3 was positively correlated with cell proliferation and clone formation in vitro, as well as lesions growth in nude mice. By adding the phosphatidylinositol 3 kinase/protein kinase B(PI3K/AKT) pathway inhibitor LY294002 and knocking down PI3K, we further verified that TIM-3 promotes proliferation in vivo and in vitro via the PI3K pathway. By transfecting the plasmid into ESC cells and gave inhibitors to endometriotic rats models, we tested that TIM-3 regulates the proliferation by BDNF-mediated PI3K/AKT axis. CONCLUSION: TIM-3 can promote the proliferation of endometriosis by BDNF-mediated PI3K/AKT axis in vivo and in vitro, which may provide a new therapeutic target for the treatment of endometriosis.

Generation and identification of 1O2 in catalysts/peroxymonosulfate systems for water purification.

Catalysts for peroxymonosulfate (PMS) activation are appealing in the purification of organic wastewater. Singlet oxygen (1O2) is widely recognized as a crucial reactive species for degrading organic contaminants in catalysts/PMS systems due to its adamant resistance to inorganic anions, high selectivity, and broad pH applicability. With the rapid growth of studies on 1O2 in catalysts/PMS systems, it becomes necessary to provide a comprehensive review of its current state. This review highlights recent advancements concerning 1O2 in catalysts/PMS systems, with a primary focus on generation pathways and identification methods. The generation pathways of 1O2 are summarized based on whether (distinguished by the geometric structures of metal species) or not (distinguished by the active sites) the metal element is included in the catalysts. Furthermore, this review thoroughly discusses the influence of metal valence states and metal species with different geometric structures on 1O2 generation. Various potential strategies are explored to regulate the generation of 1O2 from the perspective of catalyst design. Identification methods of 1O2 primarily include electron paramagnetic resonance (EPR), quenching experiments, reaction in D2O solution, and chemical probe tests in catalysts/PMS systems. The principles and applications of these methods are presented comprehensively along with their applicability, possible disagreements, and corresponding solutions. Besides, an identifying procedure on the combination of main identification methods is provided to evaluate the role of 1O2 in catalysts/PMS systems. Lastly, several perspectives for further studies are proposed to facilitate developments of 1O2 in catalysts/PMS systems.

Coalescence of As(II) with •OH: The pivot for co-processing of As(III) and butyl xanthate.

Although water metalloid pollution is widely studied, the effect of the combined pollution of organic matter and metalloids in mining water and, especially, the possible interaction mechanisms between metalloids and flotation reagents, are both poorly understood. Existence of mixed pollution of metalloids and organic compounds tends to cause more serious harm to natural organisms. In this study, a synergistic removal of arsenite (As(III)) and butyl xanthate (Bx) in an advanced oxidation system was reported using biochar-based catalyst loaded with nano-zero-valent iron from an inexpensive iron source (iron slag) to activate peroxodisulfate. The removal efficiencies were improved by 30 % in the co-existence of As(III) and Bx compared to those of the single pollutant. The theoretical calculations, especially frontier molecular orbital theory, revealed the generation of [AsO2-OH]•- by the combination of As(II) with •OH. This [AsO2-OH]•- participated in the oxidative degradation of Bx with high activity and combined with the sulfur falling off Bx after the reaction to form a novel Fe-As-S complex as indicated by X-ray absorption +fine structure analysis. Overall, this study reports the generation of low-valent arsenic active substances of [AsO2-OH]•- and their effect on the removal of organic pollution containing S atoms in advanced oxidation systems under typical mining water conditions with the coexistence of As(III) and expands the understanding and application of traditional free radicals.

Enhancing quorum quenching media with 3D robust electrospinning coating: A novel biofouling control strategy for membrane bioreactors.

Bacterial quorum quenching (QQ) is an effective strategy for controlling biofouling in membrane bioreactor (MBR) by interfering the releasing and degradation of signal molecules during quorum sensing (QS) process. However, due to the framework feature of QQ media, the maintenance of QQ activity and the restriction of mass transfer threshold, it has been difficult to design a more stable and better performing structure in a long period of time. In this research, electrospun fiber coated hydrogel QQ beads (QQ-ECHB) were fabricated by using electrospun nanofiber coated hydrogel to strengthen layers of QQ carriers for the first time. The robust porous PVDF 3D nanofiber membrane was coated on the surface of millimeter-scale QQ hydrogel beads. Biocompatible hydrogel entrapping quorum quenching bacteria (sp.BH4) was employed as the core of the QQ-ECHB. In MBR with the addition of QQ-ECHB, the time to reach transmembrane pressure (TMP) of 40 kPa was 4 times longer than conventional MBR. The robust coating and porous microstructure of QQ-ECHB contributed to keeping a lasting QQ activity and stable physical washing effect at a very low dosage (10g beads/5L MBR). Physical stability and environmental-tolerance tests also verified that the carrier can maintain the structural strength and keep the core bacteria stable when suffering long-term cyclic compression and great fluctuations in sewage quality.

A critical review on microbial ecology in the novel biological nitrogen removal process: Dynamic balance of complex functional microbes for nitrogen removal.

The novel biological nitrogen removal process has been extensively studied for its high nitrogen removal efficiency, energy efficiency, and greenness. A successful novel biological nitrogen removal process has a stable microecological equilibrium and benign interactions between the various functional bacteria. However, changes in the external environment can easily disrupt the dynamic balance of the microecology and affect the activity of functional bacteria in the novel biological nitrogen removal process. Therefore, this review focuses on the microecology in existing the novel biological nitrogen removal process, including the growth characteristics of functional microorganisms and their interactions, together with the effects of different influencing factors on the evolution of microbial communities. This provides ideas for achieving a stable dynamic balance of the microecology in a novel biological nitrogen removal process. Furthermore, to investigate deeply the mechanisms of microbial interactions in novel biological nitrogen removal process, this review also focuses on the influence of quorum sensing (QS) systems on nitrogen removal microbes, regulated by which bacteria secrete acyl homoserine lactones (AHLs) as signaling molecules to regulate microbial ecology in the novel biological nitrogen removal process. However, the mechanisms of action of AHLs on the regulation of functional bacteria have not been fully determined and the composition of QS system circuits requires further investigation. Meanwhile, it is necessary to further apply molecular analysis techniques and the theory of systems ecology in the future to enhance the exploration of microbial species and ecological niches, providing a deeper scientific basis for the development of a novel biological nitrogen removal process.

MicroRNA-9a-5p inhibits mucosal barrier injury in inflammatory bowel disease.

Our previous research found that FOXO1 aggravates the mucosal barrier injury in inflammatory bowel disease (IBD) by regulating TLR4/MD2 signaling. In this study, we further reveal the mechanism of action whereby miRNA-9a-5p inhibits the mucosal barrier injury after regulating FOXO1. An IBD model was established in C57BL/6N mice using dextran sulfate sodium (DSS). The effects of endogenous miRNA-9a-5p were mimicked/antagonized by intraperitoneally injecting miRNA-9a-5p agomir and antagomir. Body weights of mice were monitored and the disease activity index scores were assessed. H&E staining was performed to examine pathological changes, while immunohistochemical (IHC) staining was conducted to measure the expressions of TJ proteins (ZO-1, Occludin), as well as FOXO1 and TLR4. The mucosal permeability was assessed by FITC-D, the tissue inflammatory cytokines were detected by enzyme linked immunosorbent assay, and the expressions of ZO-1 and Occludin were measured through Western blot analysis. Caco-2 cells were cultured in vitro to establish a monolayer model of the mucosal barrier. TNF-α was used to induce the cell damage, while agomir and antagomir were transfected to mimic/antagonize the miRNA-9a-5p action, followed by determination of barrier permeability. There was a targeted regulatory relationship between MiRNA-9a-5p and FOXO1. MiRNA-9a-5p could suppress the FOXO1 expression, thereby downregulating the TLR4 signaling activation, inhibiting the mucosal barrier injury, and elevating the expressions of TJ proteins. We also found in Caco-2 cells that miRNA-9a-5p could protect cells from inflammatory injury and reduce permeability. In rescue experiments, the effect of agomir was found inhibited by the overexpression of FOXO1 in agomir-treated cells. This study found that miRNA-9a-5p could inhibit the TLR4 signaling activation by targeting FOXO1, thereby exerting a protective effect on the mucosal barrier injury in IBD.

Speciation and release risk of heavy metals bonded on simulated naturally-aged microplastics prepared from artificially broken macroplastics.

The negative impact of microplastics (MPs) act as metals vectors to environment and ecosystem have been paid more and more attention, and the accumulation risk of them to human body through the food chains and food webs needs to attract attention. In addition, the MPs bonded with heavy metals transport from river into the sea with high salinity may also have metals release risk. Herein, natural aged microplastics prepared from artificially broken macroplastics adsorbed with heavy metals accumulated from the natural environment were tested for their states and release risk in several simulated solution (NaCl and gastrointestinal solutions) to understand their effects on environment and human health. The adsorption capacity of different heavy metals on MPs was different during natural aging process proved by four-acid digestion method. Metals with high accumulation (including Pb, As, Cr, Mn, Ni, Zn, Co, Cu and Cd) on NAMPs were selected for further study. Results obtained via three-step extraction method showed that these heavy metals were mainly present as acid-extractable and reducible ions, which were characterized by high bioavailability. Release experiments suggested the notable Mn, Zn, As, Cr, Cu and Ni release in NaCl solution, and significant release of Mn, Zn, As, Cr, Cu, Pb and Ni in gastrointestinal solutions. The high metal release ratio in the simulated gastric solution was attributed to the weak binding of metal ions to NAMPs in acidic environment. This study will play a vital rule in assessing the ecological risks associated with MPs in natural environment.

The potential predictive value of salivary cortisol on the occurrence of secondary cognitive impairment after ischemic stroke.

In this study, we aimed to investigate the relationship between salivary cortisol content and secondary mild cognitive impairment (MCI), thereby supporting the prediction of MCI in clinical practice. In this study, the salivary cortisol levels were examined in 120 patients with MCI after cerebral ischemic stroke (CIS) (CIS-MIC) and 80 CIS patients without MIC (CIS). The clinical data were compared among these patients with different cortisol levels. The salivary level of cortisol was significantly higher in patients with CIS-MIC (0.85-3.65 nmol/L) than that in those with CIS (0.52-1.21 nmol/L). The categorized analysis by CIS-MIC quartile showed that patient age, hyperlipidemia, total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), etc. were significantly increased with increasing salivary cortisol levels. Moreover, univariate and multivariate logistic regression analyses revealed that the MCI risk of patients in the first quartile was 0.35 and 0.41 times, respectively, of the fourth quartile. Multiple linear regression showed that patient age, the time of rescue, and the salivary cortisol level were independent factors in the Mini-Mental State Exam (MMSE) score of MCI patients. Meanwhile, the receiver operating characteristic (ROC) curve showed that the area under the curve of salivary cortisol as a diagnostic marker for MCI after CIS was 0.982, with sensitivity of 0.973 and specificity of 0.980. In this study, we found that salivary cortisol level was an independent risk factor of MCI after CIS. A higher salivary cortisol level indicated a higher probability of MCI occurrence, and salivary cortisol level can be used as a predictive marker for MCI occurrence.

Mechanism analysis of heavy metal lead captured by natural-aged microplastics.

In this paper, the mechanism of lead (Pb(II)) captured by natural-aged microplastics in aqueous medium was explored. Compared with pristine microplastics, the natural-aged microplastics were more efficient for adsorbing Pb(II). After treated by hydrochloric acid (HCl) or sodium hydroxide (NaOH), the organic film was damaged and the adsorption efficiency decreased obviously, which proved that the organic film played an important role in Pb(II) capture. The fitting results of the isothermal adsorption model showed that this adsorption process was more in line with Langmuir model than with Freundlich model, and the maximum adsorption amount (13.60 mg/g) could also be obtained from the Langmuir model. Based on the comprehensive analysis of XRD, XPS and FTIR results, it was found that Pb(II) capture by natural-aged microplastics was mainly determined by the oxygen containing functional groups (carboxyl and hydroxyl groups) on the organic film. Besides, the measurement results of Zeta potential and pH effect showed that electrostatic interaction was mainly responsible for the Pb(II) capture process.

Correlation between LncRNA-LINC00659 and clinical prognosis in gastric cancer and study on its biological mechanism.

Non-coding RNAs play important roles in tumorigenesis and tumour progression. In previous screening, lncRNA-LINC00659 (LINC00659) is highly expressed in gastric cancer; however, its role in gastric cancer has not been illustrated yet. In this study, the expression of LINC00659 was detected in cancer tissues and paracancerous tissues of patients with gastric cancer. As a result, LINC00659 expression was increased in gastric cancer tissues, which was closely associated with tumour stage and lymph node metastasis, but was not correlated with age, gender and tissue differentiation. Survival curve analysis showed that patients with low expression of LINC00659 harboured higher overall survival. In vitro, the level of LINC00659 was increased in gastric cancer cells. Afterwards, the expression of LINC00659 was down-regulated in SGC-7901 and BGC-823 cells by plasmid-mediated si-LINC00659 transfection. Consequently, the cell invasion ability was weakened, the cell cycle was inhibited, and cell viability was also suppressed. Luciferase reporter gene assay and RNA pull-down assay showed that LINC00659 could bind to the transcription factor SUZ12, indicating that SUZ12 was a regulatory gene of LINC00659. The overexpression of SUZ12 could resist the roles of si-LINC00659. In this study, we found that LINC00659 was highly expressed in gastric cancer, which might be related to the regulation of cell proliferation and promotion of cell invasion. Transcription factor, SUZ12, was a regulator of LINC00659. Additionally, LINC00659 could regulate cell cycle and invasion of gastric cancer by promoting the expression of SUZ12.

Rice waste biochars produced at different pyrolysis temperatures for arsenic and cadmium abatement and detoxification in sediment.

The effectiveness of rice waste biochars on heavy metal and metalloid abatement and detoxification was investigated using comprehensive studies based on As and Cd immobilization, bioaccumulation in tubifex, and microbial community changes in contaminated sediment. The remediation effects of biochars produced at different pyrolytic temperatures (400-700 °C) were evaluated. Bioaccumulation of heavy metal and metalloid in the tubifex tissue and change of indigenous microbial community under treatment of different biochars were assessed. Biochars produced at 700 °C exhibited greater effect on decreasing the concentrations of As and Cd in aqueous phase, and TCLP extractable and bioavailable metal(loid) in solid phase of sediment. The concentration of As and Cd in water phase decreased by 26%-89% and 22%-71% under the treatment of straw biochar, and decreased by 13%-92% and 5%-64% under the treatment of rice husk biochar, respectively. As and Cd contents in the tubifex tissue were positively correlated with their concentrations in aqueous phase. High-temperature biochars significantly reduced metal(loid) bioaccumulation in tubifex. The richness and biodiversity of microbial community were both greater in all biochars remediated sediment compared to non-treated sediment. These results indicated that rice waste biochars could effectively inhibit the bio-availability and toxicity of heavy metal and metalloid in sediment, and the higher-temperature biochar exhibited better performance.

FoxO1 regulates TLR4/MyD88/MD2-NF-κB inflammatory signalling in mucosal barrier injury of inflammatory bowel disease.

In this study, FoxO1 transgenic mice (transgenic, FoxO1-Tg) and C57BL/6 wild-type (wild-type, FoxO1-WT) mice were used to establish chronic colitis by drinking water containing dextran sulphate sodium (DSS). Afterwards, we observed the life changes in mice and assessed the pathological changes by H&E tissue staining. In addition, the TLR4/MyD88/MD2-NF-κB inflammatory signals were detected. As a result, under DSS treatment, the activation level of TLR4/MyD88/MD2-NF-κB inflammatory signal was higher in FoxO1-Tg mice than that in FoxO1-WT mice. Meanwhile, the intestinal mucosal tissue damage was more severe, the down-regulation of tight junction protein level was more significant and the life quality was decreased to a higher degree in FoxO1-Tg mice compared with those in FoxO1-WT mice. Caco-2 cells were used to mimic the intestinal mucosal barrier model for in vitro assays. In addition, lentiviral packaging FoxO1 overexpressing plasmid was transfected into Caco-2 cells for FoxO1 overexpression. TNF-α intervention was performed for intestinal mucosal inflammatory response model. Consequently, the down-regulation of FoxO1 inhibited the activation of TLR4/MyD88/MD2-NF-κB inflammatory signal, decreased the mucosal barrier permeability and up-regulated the expression of tight junction protein. By contrast, the overexpression of FoxO1 increased the mucosal barrier permeability and down-regulated the level of tight junction protein.

New mechanism of neuroinflammation in Alzheimer's disease: The activation of NLRP3 inflammasome mediated by gut microbiota.

Alzheimer's disease (AD) is a central degenerative disease characterized by cognitive impairment. Polymerization of ß-amyloid has been reported to cause the entanglement of nerve cells, leading to the progressive loss of nerve cells. Accumulative studies have confirmed the important roles of neuroinflammation in the development of AD. In this study, the gut microbiota from AD patients were transplanted into APP/PS1 double transgenic mice. As a result, the expression of NLRP3 was increased in the intestinal tract of mice, and the expression levels of inflammatory factors in peripheral blood were also increased. Consistently, the cognitive impairment was more severe in mice receiving gut microbiota from AD patients than those did not, with activation of microglia in the central hippocampus of mice, and increased expression of neuroinflammatory factors. In APP/PS1 mice transplanted with gut microbiota from AD patients, transplantation of healthy human gut microbiota or oral administration of minocycline was further used to improve the composition of gut microbiota. Consequently, the intestinal expression of NLRP3 was down-regulated, the cognitive ability of mice was improved, the activation of microglia in central hippocampus was suppressed and the expression of neuroinflammatory factors was also down-regulated. After transplantation of gut microbiota from AD patients in C57BL/6 mice, the intestinal expression of NLRP3 was up-regulated. Although the cognitive ability of mice was not significantly changed, the microglia in the hippocampus of mice were still activated and the expression of inflammatory factors was up-regulated. In this study, we found that gut microbiota in AD patients could induce the activation of NLRP3 inflammasome in the intestinal tract of mice, subsequently causing the release of inflammatory factors. The absorption and circulation of inflammatory factors through the intestinal tract could further aggravate the inflammation in the nervous tissues and the activation of microglia. Therefore, improving the composition of gut microbiota in AD patients can further attenuate neuroinflammation, which is considered as a novel idea for AD treatment.

Design and Preparation of Chitosan-Crosslinked Bismuth Ferrite/Biochar Coupled Magnetic Material for Methylene Blue Removal.

Biochar obtained by pyrolysis of the fiber plant kenaf was mixed with bismuth ferrite (BiFeO3) in a chitosan-containing acetic acid solution, magnetized, and modified to prepare a chitosan-crosslinked BiFeO3/biochar coupled magnetic material. The adsorption properties of the composite were investigated using methylene blue dissolved in water, and the effects of external conditions, such as pH, methylene blue concentration, reaction time, and temperature, on the adsorption performance were studied. The adsorption data were fitted and analyzed with kinetic and isotherm models, and the results showed that the BiFeO3/biochar coupled magnetic material effectively adsorbed methylene blue. The amounts adsorbed onto this magnetic material increased with increasing initial methylene blue concentration, reaction time, and temperature, and the adsorption performance improved under neutral and alkaline conditions. The pseudo-first-order kinetic and Langmuir isotherm models satisfactorily fitted the adsorption data, showing that the adsorption of methylene blue involved both chemical and physical adsorption. The maximum adsorption capacity of methylene blue onto the BiFeO3/biochar coupled magnetic material reached 18.942 mg·g-1 at 25 °C, confirming the excellent dye binding activity of this material.

Roles of surfactants in pressure-driven membrane separation processes: a review.

Surfactants widely exist in various kinds of wastewaters which could be treated by pressure-driven membrane separation (PDMS) techniques. Due to the special characteristics of surfactants, they may affect the performance of membrane filtration. Over the last two decades, there are a number of studies on treating wastewaters containing surfactants by PDMS. The current paper gives a review of the roles of surfactants in PDMS processes. The effects of surfactants on membrane performance were discussed via two aspects: influence of surfactants on membrane fouling and enhanced removal of pollutants by surfactants. The characteristics of surfactants in solution and at solid-liquid interface were summarized. Surfactants in membrane filtration processes cause membrane fouling mainly through adsorption, concentration polarization, pore blocking, and cake formation, and fouling degree may be influenced by various factors (feed water composition, membrane properties, and operation conditions). Furthermore, surfactants may also have a positive effect on membrane performance. Enhanced removal of various kinds of pollutants by PDMS in the presence of surfactants has been summarized, and the removal mechanism has been revealed. Based on the current reports, further studies on membrane fouling caused by surfactants and enhanced removal of pollutants by surfactant-aided membrane filtration were also proposed.

Functionalized Biochar/Clay Composites for Reducing the Bioavailable Fraction of Arsenic and Cadmium in River Sediment.

Biochar has frequently been used for the treatment of heavy metal pollution in water and soil; its effect on contaminated sediments requires further research. To improve the ability of biochar to immobilize heavy metals in sediment, we prepared a functionalized biochar/attapulgite composite by pyrolysis of the clay attapulgite and zinc chloride-pretreated rice straw biomass. Compared with the original biochar, the biochar/attapulgite composite had a large increase in specific surface area, pore volume, oxygen-containing functional groups, and cation exchange capacity. Biochar effectively improved the dispersibility of attapulgite as a matrix. The results showed that the biochar/attapulgite composite effectively reduced the bioavailable fraction of arsenic (As) and cadmium (Cd) in river sediment, which was a great improvement compared with the raw biochar. After the sediment was treated with different biochar/attapulgite composites, the concentrations of As and Cd in the overlying water and the porewater, and the content of acid-extractable and toxicity characteristic leaching procedure (TCLP)-extractable As and Cd in the solid phase of the sediment decreased significantly. Both zinc chloride activation and attapulgite improved As and Cd immobilization in sediment when we used the biochar/attapulgite composite. The results suggest that biochar/attapulgite composite can be used as an efficient in situ sorbent amendment to improve the heavy metal immobilization ability of the sediment. Environ Toxicol Chem 2019;38:2337-2347. © 2019 SETAC.

The role of quorum sensing in granular sludge: Impact and future application: A review.

Quorum sensing (QS) is a process widely exist in bacteria, which refers to the cell-cell communication through secretion and sensing the specific chemical signal molecules named autoinducers. This review demonstrated recent research progresses on the specific impacts of signal molecules in the granular sludge reactors, such corresponding exogenous strategies contained the addition of QS signal molecules, QS-related enzymes and bacteria associated with QS process. Accordingly, the correlation between QS signaling molecule content and sludge granulation (including the formation and stability) was assumed, the comprehensive conclusion elucidated that some QS signals (acyl-homoserine lactone and Autoinducer 2) can accelerate the growth of particle diameter, the production of extracellular polymeric substance (EPS), microbial adhesion and change the microbiome structure. But diffusable signal factor (DSF) acted as a significant disincentive to the formation and stability of GS. As a result, it deserved serious attention on the value and role of QS signals in the GS. This review attempts to illuminate the potential method for addressing the main bottleneck: to accelerate the formation of granules and keep the high stability of GS for a long-term reactor. Therefore, review discussed the possible trends of GS: QS and intercellular/intracellular signaling which can lay a theoretical foundation for mechanism of GS formation and stability, would be of practical significance for further application in the future.

[Research advances in endogenous neural stem cells promoting neural repair after ischemic stroke].

Neural stem cell therapy, as a new therapeutic method for neural diseases, has aroused a wide concern for over 20 years since neural stem cells were first found in 1992. Ischemic stroke is highly concerned because of its high incidence, mortality and disability rates. Because the brain has a limited ability to repair itself, to improve neural function and promote neural regeneration may help to prevent occurrence and development of neurological diseases. It is noteworthy that some stroke patients showed an ability to repair brain several months after the stroke happened, suggesting an existence of endogenous nerve repair in these patients. The research advances in functions of endogenous neural stem cells in neural regeneration and the related regulators after ischemic stroke are summarized in this review to provide new views of the mechanism of neural functional recovery after ischemic stroke.