Effects of Alkaline Cleaning on the Conversion and Transformation of Functional Groups on Ion-Exchange Membranes in Polymer-Flooding Wastewater Treatment: Desalination Performance, Fouling Behavior, and Mechanism.

The aging effects of sodium hydroxide (NaOH) on ion-exchange membranes were systematically studied, including the membrane properties, desalination performance, and fouling behaviors. After aging in NaOH solution, there were minor changes in the cation-exchange membrane (CEM) properties; however, functional groups (i.e., quaternary amines) on the anion-exchange membranes (AEMs) were converted into benzylic alcohol, alkene, and tertiary amines, respectively, by nucleophilic substitution, Hofmann elimination, and ylide formation. These degradations rendered decreased ion-exchange capacity (IEC), increased electrical resistance, lost hydrophilicity, and weakened mechanical strength. Moreover, severe deteriorations of desalination performance were observed due to the little ion-exchange ability of the degraded AEMs. The desalination rates were restored after cultivating the aged AEMs in acid solution, mainly because the tertiary amines transformed from the hydroxide form (OH-form) to the ionic chlorine form (Cl-form). The restored desalination rates indicated that the main degradation products were tertiary amines. In addition, the antifouling performance decreased in the order of aged OH-form > aged Cl-form > original AEMs due to the reduction of foulant-membrane intermolecular interactions after aging in NaOH solution. The results contribute to establishing a more comprehensive understanding of the effects of alkaline cleaning on IEMs and provide new insights into cleaning-process optimization and membrane modification.

pH-sensitive microfiltration membrane prepared from polyethersulfone grafted with poly(itaconic acid) synthesized by simultaneous irradiation in homogeneous phase.

Poly(itaconic acid) (PIA) was grafted onto polyethersulfone (PES) by homogeneously phased γ-ray irradiation. Kinetic polymerization observed was studied by analyzing the effect of irradiation dosages and monomer concentrations. Then, a pH-sensitive microfiltration (MF) membrane was prepared from these PES-g-PIA polymers with different degrees of grafting under phase inversion method. Finally, the contact angles, morphologies, pore sizes, deionized water permeability and filtration performance for aqueous polyethylene glycols solution of the MF membranes were studied. The results show that grafting PIA groups onto PES molecular chains endowed the MF membranes with effective pH-sensitive properties.

Molecular Mechanisms of Ultrafiltration Membrane Fouling in Polymer-Flooding Wastewater Treatment: Role of Ions in Polymeric Fouling.

Polymer (i.e., anionic polyacrylamide (APAM)) fouling of polyvinylidene fluoride (PVDF) ultrafiltration (UF) membranes and its relationships to intermolecular interactions were investigated using atomic force microscopy (AFM). Distinct relations were obtained between the AFM force spectroscopy measurements and calculated fouling resistance over the concentration polarization layer (CPL) and gel layer (GL). The measured maximum adhesion forces (Fad,max) were closely correlated with the CPL resistance (Rp), and the proposed molecular packing property (largely based on the shape of AFM force spectroscopy curve) of the APAM chains was related to the GL resistance (Rg). Calcium ions (Ca(2+)) and sodium ions (Na(+)) caused more severe fouling. In the presence of Ca(2+), the large Rp corresponded to high foulant-foulant Fad,max, resulting in high flux loss. In addition, the Rg with Ca(2+) was minor, but the flux recovery rate after chemical cleaning was the lowest, indicating that Ca(2+) created more challenges in GL cleaning. With Na(+), the fouling behavior was complicated and concentration-dependent. The GL structures with Na(+), which might correspond to the proposed molecular packing states among APAM chains, played essential roles in membrane fouling and GL cleaning.

Novel dual-responsive hydrogel composed of polyacrylamide/Fe-MOF/zinc finger peptide for construction of electrochemical sensing platform.

Responsive hydrogels have received much attention for improving the detection performance of electrochemical sensors because of their special responsiveness. However, current responsive hydrogels generally suffer from long response times, ranging from tens of minutes to several hours. This situation severely limits the detection performance and practical application of electrochemical sensors. Here, an electrochemical sensing platform was constructed by employing dual-responsive polyacrylamide/zinc finger peptide/Fe-MOF hydrogel (PZFH) as the silent layer, sodium alginate-Ni2+-graphene oxide hydrogel as the signal layer. GOx@ZIF-8, as the immunoprobe, catalyzed glucose to H2O2 and gluconic acid, resulting in the cleavage of immunoprobe as the pH decreased and subsequent release of Zn2+ ions. During the process of Fe-MOF converting from Fe3+ to Fe2+, free radicals were generated and used to destroy the structure of the PZFH. Cysteine and histidine in the zinc finger peptide can specifically bind to Zn2+ to create many pores in PZFH, exposing the signal layer. These synergistic effects rapidly decreased the impedance of PZFH and increased the electrochemical signal of Ni2+. The electrochemical sensing platform was used to detect pro-gastrin-releasing peptide with response times as short as 7 min of PZFH, a wide linear range from 100 ng mL-1 to 100 fg mL-1, and an ultra-low limit of detection of 14.24 fg mL-1 (S/N = 3). This strategy will provide a paradigm for designing electrochemical sensors.

Clinical Significance of Porphyromonas gingivalis Enriching Cancer Stem Cells by Inhibiting Programmed Cell Death Factor 4 in Esophageal Squamous Cell Carcinoma.

Studies have confirmed that the colonization of Porphyromonas gingivalis (Pg) could promote the malignant evolution of esophageal squamous cell carcinoma (ESCC). Since pathogenic microorganisms can promote malignant tumor proliferation by inhibiting programmed cell death factor 4 (PDCD4) and the decrease of PDCD4 activity can enhance the stemness of cancer cells, we here investigated the functional mechanism by which Pg promoted ESCC chemoresistance and malignancy through inhibiting PDCD4 and enriching cancer stem cells (CSCs). The effects of Pg and PDCD4 on CSCs, chemoresistance and malignancy of ESCC cells were evaluated by in vitro studies. The expression of Pg, PDCD4, and ALDH1 in ESCC tissues were detected by IHC, and the correlations between each index and postoperative survival of ESCC patients were analyzed. The results showed that Pg could inhibit PDCD4 expression and lead to CSCs enrichment in ESCC cells. After eliminating Pg, the expression of PDCD4 was upregulated, the percentage of CSCs, chemoresistance and malignancy were decreased. ESCC patients with Pg-positive, PDCD4-negative, and ALDH1-positive have a significant shorter survival. This study proved that eliminating Pg and blocking CSCs enrichment caused by decreasing PDCD4 activity may provide a new strategy for ESCC treatment.

Porphyromonas gingivalis promotes malignancy and chemo-resistance via GSK3ß-mediated mitochondrial oxidative phosphorylation in human esophageal squamous cell carcinoma.

Our prior studies have confirmed that long-term colonization of Porphyromonas gingivalis (Pg) and overexpression of the inflammatory factor glycogen synthase kinase 3ß (GSK3ß) promote the malignant evolution of esophageal squamous cell carcinoma (ESCC). We aimed to investigate the functional mechanism by which Pg could promote ESCC malignancy and chemo-resistance through GSK3ß-mediated mitochondrial oxidative phosphorylation (mtOXPHOS), and the clinical implications. The effects of Pg and GSK3ß on mtOXPHOS, malignant behaviors and response to paclitaxel and cisplatin treatment of ESCC cells were evaluated by in vitro and in vivo studies. The results showed that Pg induced high expression of the GSK3ß protein in ESCC cells and promoted the progression and chemo-resistance via GSK3ß-mediated mtOXPHOS in human ESCC. Then, Pg infection and the expression of GSK3ß, SIRT1 and MRPS5 in ESCC tissues were detected, and the correlations between each index and postoperative survival of ESCC patients were analysed. The results showed that Pg-positive ESCC patients with high-expression of GSK3ß, SIRT1 and MRPS5 have significant short postoperative survival. In conclusion, we demonstrated that the effective removal of Pg and inhibition of its promotion of GSK3ß-mediated mtOXPHOS may provide a new strategy for ESCC treatment and new insights into the aetiology of ESCC.

Anti-fouling and protein separation of PVDF-g-PMAA@MnO2 filtration membrane with in-situ grown MnO2 nanorods.

MnO2 nanorods with controllable scale were grown in the PVDF-g-PMAA modified membrane to form PVDF-g-PMAA@ MnO2 membrane through the in situ redox reaction of KMnO4 solution, which is confirmed by scanning electron microscopy (SEM) and X-ray energy-dispersion spectroscopy (EDX). The pore size of the membrane decreased with the increase of KMnO4 solution concentration. The thermodynamic stability and the hydrophilicity of the membrane were also enhanced by the MnO2 nanorods. The water flux, bovine serum albumin (BSA)/Lysozyme protein solution flux and rejection, flux recovery, etc. showed effective improvement of the anti-fouling performance of the PVDF-g-PMAA@ MnO2 membrane. More importantly, it can effectively separate BSA from lysozyme, which provided a potential application in the field of biology, food, and other industrial fields for the requirement of separation and purification.

Associations of Porphyromonas gingivalis Infection and Low Beclin1 Expression With Clinicopathological Parameters and Survival of Esophageal Squamous Cell Carcinoma Patients.

Purpose: The present study focused on exploring the associations of Porphyromonas gingivalis (P. gingivalis) infection and low Beclin1 expression with clinicopathological parameters and survival of esophageal squamous cell carcinoma (ESCC) patients, so as to illustrate its clinical significance and prognostic value. Methods: Immunohistochemistry (IHC) was used to detect P. gingivalis infection status and Beclin1 expression in 370 ESCC patients. The chi-square test was adopted to illustrate the relationship between categorical variables, and Cohen's kappa coefficient was used for correlation analysis. Kaplan-Meier survival curves with the log-rank test were used to analyse the correlation of P. gingivalis infection and low Beclin1 expression with survival time. The effects of P. gingivalis infection and Beclin1 downregulation on the proliferation, migration and antiapoptotic abilities of ESCC cells in vitro were detected by Cell Counting Kit-8, wound healing and flow cytometry assays. For P. gingivalis infection of ESCC cells, cell culture medium was replaced with antibiotic-free medium when the density of ESCC cells was 70-80%, cells were inoculated with P. gingivalis at a multiplicity of infection (MOI) of 10. Result: P. gingivalis infection was negatively correlated with Beclin1 expression in ESCC tissues, and P. gingivalis infection and low Beclin1 expression were associated with differentiation status, tumor invasion depth, lymph node metastasis, clinical stage and prognosis in ESCC patients. In vitro experiments confirmed that P. gingivalis infection and Beclin1 downregulation potentiate the proliferation, migration and antiapoptotic abilities of ESCC cells (KYSE150 and KYSE30). Our results provide evidence that P. gingivalis infection and low Beclin1 expression were associated with the development and progression of ESCC. Conclusion: Long-term smoking and alcohol consumption causes poor oral and esophageal microenvironments and ESCC patients with these features were more susceptible to P. gingivalis infection and persistent colonization, and exhibited lower Beclin1 expression, worse prognosis and more advanced clinicopathological features. Our findings indicate that effectively eliminating P. gingivalis colonization and restoring Beclin1 expression in ESCC patients may contribute to preventation and targeted treatment, and yield new insights into the aetiological research on ESCC.

Clinical significance and prognostic value of Porphyromonas gingivalis infection in lung cancer.

A variety of pathogenic microorganisms can promote the occurrence and development of malignant tumors by colonizing in the body. It has been shown that Porphyromonas gingivalis (P. gingivalis) can be colonized for a long time in upper gastrointestinal tumors and is closely related to the occurrence and development of esophageal cancer in previous studies of our team. Because the esophagus and trachea are closely adjacent and P. gingivalis can instantly enter and colonize in cells, we speculate that P. gingivalis may be colonized in lung cancer cells through oral or blood, promoting the malignant progression of lung cancer. In this study, we investigated P. gingivalis infection in lung carcinoma tissues and adjacent lung tissues, and found that the colonization rate of P. gingivalis in carcinoma tissues was significantly higher than that in adjacent lung tissues. Therefore, we propose that the microenvironment of cancer cells is more conducive to the survival of P. gingivalis. Then, we analyzed the correlation between P. gingivalis infection and clinicopathological features and survival prognosis of patients with lung cancer. It was found that P. gingivalis infection was closely related to smoking, drinking, lymph node metastasis and clinical stage. Moreover, the survival rate and median survival time of patients with P. gingivalis infection were significantly shortened. Therefore, we put forward the view that long term smoking and drinking will cause a bad oral environment, increasing the risk of P. gingivalis infection, then P. gingivalis infection will promote the malignant progression of lung cancer.

[Study on P forms in extracellular polymeric substances in enhanced biological phosphorus removal sludge by 31P-NMR spectroscopy].

The present paper investigated phosphorus forms in the extracellular polymeric substances (EPS) using 31P-NMR spectroscopy, and analyzed the influential parameters for this method. The results showed that in the three investigated EPS samples five P forms were identified, including orthophosphate, orthophosphate monoesters, DNA, pyrophosphate and polyphosphate. And in the EPS extracted from A/A/O sludge and A/A/O-MBR sludge polyphosphate was the main phosphorus form. This indicated that P is contained in the EPS not only owing to the adsorption of orthophosphate, but also because EPS acting like the bacteria cells contributes to enhanced biological phosphorus removal. Furthermore the transformation of P forms in the EPS during the EPS extraction was found but limited within 1 h. It was found that with the NaOH solution added the polyphosphate in the EPS would partly convert to pyrophosphate but not go further to orthophosphate, while with pure water added P forms in the EPS were very stable. This means that after neutralization, the transformation of phosphorus forms could be avoided. Since the measurement of 31P-NMR spectroscopy was very sensitive to pH, which could affect the chemical shift of the peaks and cause peaks overlapping, the pH of EPS sample must be raised to 13.0 before the measurement.

Evaluation of Salivary Exosomal Chimeric GOLM1-NAA35 RNA as a Potential Biomarker in Esophageal Carcinoma.

PURPOSE: Transcriptionally induced chimeric RNAs are an important emerging area of research into molecular signatures for biomarker and therapeutic target development. Salivary exosomes represent a relatively unexplored, but convenient, and noninvasive area of cancer biomarker discovery. However, the potential of cancer-derived exosomal chimeric RNAs in saliva as biomarkers is unknown. Here, we explore the potential clinical utility of salivary exosomal GOLM1-NAA35 chimeric RNA (seG-NchiRNA) in esophageal squamous cell carcinoma (ESCC). EXPERIMENTAL DESIGN: In a retrospective study, the prognostic significance of G-NchiRNA was determined in ESCC tissues. The correlation between seG-NchiRNA and circulating exosomal or tumoral G-NchiRNA was ascertained in cultured cells and mice. In multiple prospective cohorts of patients with ESCC, seG-NchiRNA was measured by qRT-PCR and analyzed for diagnostic accuracy, longitudinal monitoring of treatment response, and prediction of progression-free survival (PFS). RESULTS: Exosomal G-NchiRNA was readily detectable in ESCC cells and nude mouse ESCC xenografts. SeG-NchiRNA levels reflected tumor burden in vivo and correlated with tumor G-NchiRNA levels. In prospective studies of a training cohort (n = 220) and a validation cohort (n = 102), seG-NchiRNA levels were substantially reduced after ESCC resection. Moreover, seG-NchiRNA was successfully used to evaluate chemoradiation responsiveness, as well as to detect disease progression earlier than imaging studies. Changes in seG-NchiRNA levels also predicted PFS of patients after chemoradiation. CONCLUSIONS: SeG-NchiRNA constitutes an effective candidate noninvasive biomarker for the convenient, reliable assessment of therapeutic response, recurrence, and early detection.

Synthesis of cellulose-graft-poly(N,N-dimethylamino-2-ethyl methacrylate) copolymers via homogeneous ATRP and their aggregates in aqueous media.

Cellulose-graft-poly(N,N-dimethylamino-2-ethyl methacrylate) (cellulose-g-PDMAEMA) copolymers were prepared by homogeneous atom transfer radical polymerization (ATRP) under mild conditions. Cellulose macroinitiator was successfully synthesized by direct acylation of cellulose with 2-bromopropionyl bromide in a room temperature ionic liquid (RTIL), 1-allyl-3-methylimidazolium chloride. Copolymers were obtained via ATRP of N,N-dimethylamino-2-ethyl methacrylate (DMAEMA) with CuBr/pentamethyldiethylenetriamine (PMDETA) as catalyst and N,N-dimethylformamide (DMF) as solvent without homopolymer byproduct. The grafting copolymers were characterized by (1)H NMR, FT-IR, and TGA measurements. The results confirmed that PDMAEMA had been covalently bonded to cellulose backbone. Furthermore, the assemblies or aggregates formed by cellulose-g-PDMAEMA copolymers in water were studied at various concentrations, temperatures, and pH values by means of UV, DLS, TEM, and AFM. The results indicate that the copolymers had the pH- and temperature-responsive properties similar to the expected stimuli-responses by PDMAEMA. The synthetic strategy presented here could be employed in the preparation of other novel biomaterials from a variety of polysaccharides.

Porous cellulose diacetate-SiO2 composite coating on polyethylene separator for high-performance lithium-ion battery.

The developments of high-performance lithium ion battery are eager to the separators with high ionic conductivity and thermal stability. In this work, a new way to adjust the comprehensive properties of inorganic-organic composite separator was investigated. The cellulose diacetate (CDA)-SiO2 composite coating is beneficial for improving the electrolyte wettability and the thermal stability of separators. Interestingly, the pore structure of composite coating can be regulated by the weight ratio of SiO2 precursor tetraethoxysilane (TEOS) in the coating solution. The electronic performance of lithium ion batteries assembled with modified separators are improved compared with the pristine PE separator. When weight ratio of TEOS in the coating solution was 9.4%, the composite separator shows the best comprehensive performance. Compared with the pristine PE separator, its meltdown temperature and the break-elongation at elevated temperature increased. More importantly, the discharge capacity and the capacity retention improved significantly.

Preparation and application of porous nitrogen-doped graphene obtained by co-pyrolysis of lignosulfonate and graphene oxide.

Nitrogen-doped graphene with in-plane porous structure was fabricated by simple co-pyrolysis of lignosulfonate and graphene oxide in the presence of urea. Lignosulfonate first performs as a dispersant adsorbed on the surface of graphene oxide to prevent the aggregation of graphene oxide sheets for preparing homogeneous nitrogen-containing precursor, and then acts as a porogen to render graphene sheets with nanopores in the pyrolysis process of the nitrogen-containing precursor. Urea was used as a nitrogen source to incorporate nitrogen atoms into graphene basal plane. The special nanoporous structure combined with nitrogen content of 7.41at.% endows the nitrogen-doped graphene electrode material with super capacitance up to 170Fg(-1), high rate performance, and excellent cycling stability.

[Analysis of membrane fouling genesis in nanofiltration process for advanced treatment of dyeing and finishing wastewater].

In order to investigate the types and genesis of membrane fouling of nanofiltration desalination system treating dyeing and finishing wastewater of cotton knit textile, comprehensive analysis, using ICP-AES, SEM-EDX, FTIR, TGA, high optical microscope and XRF, was carried out based on tests of influent water quality, and tests of the membrane fouling states of different processes and tests of membrane cleaning. The results showed that the types of membrane fouling included inorganic fouling, organic fouling and microbial fouling. The mass percents of bound water, organic substance and inorganic substance of dry foulants, dried at 105 degrees C, were 8.2%, 41.0% and 50.8% respectively. Ferric salt was the most serious inorganic fouling salt, and the main functional groups, found from organic foulants, were -OH, -CH and -C =C. Several kinds of protozoa were found from the membrane foulants as well as metazoan. The analysis of short-term and long-term membrane fouling indicated that it need a long time cumulative effect for the formation of organic fouling and microbial fouling. The results of NF cleaning tests showed that the mainly reason lead to the decline of membrane flux were organic fouling and microbial fouling, which took 53.3%.

Flavan-3-ols from the rhizomes of Drynaria fortunei.

One monomer flavan-3-ol, 4α-carboxymethyl-(+)-catechin methyl ester, two monomer flavan-3-ol glycosides, (+)-afzelechin-3-O-ß-allopyranoside, (+)-afzelechin-6-C-ß-glucopyranoside, two dimer flavan-3-ols, (-)-epiafzelechin-(4ß→8)-4ß-carboxymethyl-(-)-epicatechin methyl ester, and -(-)-epiafzelechin-(4ß→8)-4α-carboxymethyl-(-)epiafzelechin ethyl ester, and one trimer flavan-3-ol, (-)-epiafzelechin-(4ß→8)-(-)-epiafzelechin-(4ß→8)-4ß-carboxymethyl-(-)-epiafzelechin methyl ester, together with thirteen known flavan-3-ols were isolated from the rhizomes of Drynaria fortunei (Kunze) J.Sm (Polypodiaceae). The structures were established by analysis of their HRESIMS, 1D, 2D NMR spectroscopic, and CD data. In order to obtain improved resolution, the high-resolution NMR spectra of the dimers and trimer were measured at -40 °C.