Inhibition of biofouling by in-situ grown zwitterionic hydrogel nanolayer on membrane surface in ultralow-pressurized ultrafiltration process.

Ultralow-pressurized ultrafiltration membrane process with low energy consumption is promising in surface water purification. However, membrane fouling and low selectivity are significant barriers for the wide application of this process. Herein, an ultrathin zwitterionic hydrogel nanolayer was in-situ grown on polysulfone ultrafiltration membrane surface through interfacially-initiated free radical polymerization. The hydrogel-modified membrane possessed improved biological fouling resistance during the dynamic filtration process (bovine serum albumin, Escherichia coli and Staphylococcus aureus), comparing with commercial polysulfone membrane. The enhanced biofouling resistance ability of zwitterionic hydrogel nanolayer was derived from the foulant repulsion of hydration shell and the bactericidal effect of quaternary ammonium, according to the results of foulant-membrane interaction energy analyses and antibacterial performances. In surface water treatment, the zwitterionic hydrogel layer inhibited biofouling and resulted in the formation of a loose and thin biofilm. In addition, the hydrogel-modified membrane possessed 22% improvement in dissolved organic carbon (DOC) removal and 134% increasement in stable water flux, compared to commercial polysulfone membrane. The in-situ grown zwitterionic hydrogel nanolayer on membrane surface offers a prospectively alternative for biofouling control in ultralow-pressurized membrane process.

Enhanced Mono/Divalent Ion Separation via Charged Interlayer Channels in Montmorillonite-Based Membranes.

Efficient mono- and divalent ion separation is pivotal for environmental conservation and energy utilization. Two-dimensional (2D) materials featuring interlayer nanochannels exhibit unique water and ion transport properties, rendering them highly suitable for water treatment membranes. In this work, we incorporated polydopamine/polyethylenimine (PDA/PEI) copolymers into 2D montmorillonite (MMT) nanosheet interlayer channels through electrostatic interactions and bioinspired bonding. A modified laminar structure was formed on the substrate surface via a straightforward vacuum filtration. The electrodialysis experiments reveal that these membranes could achieve monovalent permselectivity of 11.06 and Na+ flux of 2.09 × 10-8 mol cm-2 s-1. The enhanced permselectivity results from the synergistic effect of electrostatic and steric hindrance effect. In addition, the interaction between the PDA/PEI copolymer and the MMT nanosheet ensures the long-term operational stability of the membranes. Theoretical simulations reveal that Na+ has a lower migration energy barrier and higher migration rate for the modified MMT-based membrane compared to Mg2+. This work presents a novel approach for the development of monovalent permselective membranes.

The correlation between tumor radiological features and spread through air spaces in peripheral stage IA lung adenocarcinoma: a propensity score-matched analysis.

BACKGROUND: The consolidation tumor ratio (CTR) is a predictor of invasiveness in peripheral T1N0M0 lung adenocarcinoma. However, its association with spread through air spaces (STAS) remains largely unexplored. We aimed to explore the correlation between the CTR of primary tumors and STAS in peripheral T1N0M0 lung adenocarcinoma. METHODS: We collected data from patients who underwent surgery for malignant lung neoplasms between January and November 2022. Univariate and multivariate analyses following propensity-score matching with sex, age, BMI, were performed to identify the independent risk factors for STAS. The incidence of STAS was compared based on pulmonary nodule type. A smooth fitting curve between CTR and STAS was produced by the generalized additive model (GAM) and a multiple regression model was established using CTR and STAS to determine the dose-response relationship and calculate the odds ratio (OR) and 95% confidence interval (CI). RESULTS: 17 (14.5%) were diagnosed with STAS. The univariate analysis demonstrated that the history of the diabetes, size of solid components, spiculation, pleural indentation, pulmonary nodule type, consolidation/tumor ratio of the primary tumor were statistically significant between the STAS-positive and STAS-negative groups following propensity-score matching(p = 0.047, 0.049, 0.030, 0.006, 0.026, and < 0.001, respectively), and multivariate analysis showed that the pleural indentation was independent risk factors for STAS (with p-value and 95% CI of 0.043, (8.543-68.222)). Moreover, the incidence of STAS in the partially solid nodule was significantly different from that in the solid nodule and ground-glass nodule (Pearson Chi-Square = 7.49, p = 0.024). Finally, the smooth fitting curve showed that CTR tended to be linearly associated with STAS by GAM, and the multivariate regression model based on CTR showed an OR value of 1.24 and a p-value of 0.015. CONCLUSIONS: In peripheral stage IA lung adenocarcinoma, the risk of STAS was increased with the solid component of the primary tumor. The pleural indentation of the primary tumor could be used as a predictor in evaluating the risk of the STAS.

Graphitic carbon nitride membranes intercalated with nano-sized Fe-MOF for enhanced water purification via synergistic separation and Fenton-like processes.

Versatile two-dimensional nanomaterials have offered a promising prospect to enhance the water purification efficiency and overcome the fouling obstacle in membrane technology. In this work, a graphitic carbon nitride (g-C3N4) nanosheet membrane intercalated with the nano-sized Fe-based metal-organic framework (MIL-100(Fe)) is developed for the enhanced removal of aqueous organic contaminants by synergically promoting separation and Fenton-like processes. The g-C3N4/MIL-100(Fe) membrane is constructed through a self-assembly route in which the nano-MIL-100(Fe) is anchored into g-C3N4 layers by the coordination bonds between Fe nodes and pyridinic N. The MIL-100(Fe) intercalation not only enlarges the interlayer spacing to raise the membrane permeability, but also expedites the electron transfer between Fe2+ and Fe3+ to improve the Fenton-like activity. With a stable water flux of 98.2 L m2·h-1·bar-1 under wide-range pH and pressures, the g-C3N4/MIL-100(Fe) membrane shows high dye removal efficiency (≥99%) and prominent self-cleaning ability. Mechanism insight proposes a combination of size exclusion, electrostatic interaction and steady radical generation. The intercalation of nano-MIL-100(Fe) into g-C3N4 membranes can realize the mutual promotion between separation and Fenton-like processes, the synergistic effect of which provides an effective and feasible strategy for aqueous pollution abatement.

Highly stable Ru-complex-based metal-covalent organic frameworks as novel type of electrochemiluminescence emitters for ultrasensitive biosensing.

Developing novel types of high-performance electrochemiluminescence (ECL) emitters is of great significance for constructing ultrasensitive ECL sensors. Herein, a highly stable metal-covalent organic framework (MCOF), termed Ru-MCOF, has been devised and synthesized by employing a classic ECL luminophore, tris(4,4'-dicarboxylicacid-2,2'-bipyridyl)ruthenium(II) (Ru(dcbpy)32+), as building unit and applied as a novel ECL probe to construct an ultrasensitive ECL sensor for the first time. Impressively, the topologically ordered and porous architectures of the Ru-MCOF not only allow Ru(bpy)32+ units to precisely locate and homogeneously distribute in the skeleton via strong covalent bonds but also facilitate the transport of co-reactants and electrons/ions in channels to promote the electrochemical activation of both external and internal Ru(bpy)32+ units. All these features endow the Ru-MCOF with excellent ECL emission, high ECL efficiency, and outstanding chemical stability. As expected, the constructed ECL biosensor based on the Ru-MCOF as a high-efficiency ECL probe accomplishes the ultrasensitive detection of microRNA-155. Overall, the synthesized Ru-MCOF not only enriches the MCOF family but also displays excellent ECL performance and thus expands the application of MCOFs in bioassays. Considering the structural diversity and tailorability of MCOFs, this work opens a new horizon to design and synthesize high-performance ECL emitters, therefore paving a new way to develop highly stable and ultrasensitive ECL sensors and motivating further research on MCOFs.

A Bipyridyl Covalent Organic Framework with Coordinated Cu(I) for Membrane C3 H6 /C3 H8 Separation.

Covalent organic frameworks (COFs) mixed matrix membranes (MMMs) combining individual attributes of COFs and polymers are promising for gas separation. However, applying COF MMMs for propylene/propane (C3 H6 /C3 H8 ) separation remains a big challenge due to COF inert pores and C3 H6 /C3 H8 similar molecular sizes. Herein, the designed synthesis of a Cu(I) coordinated COF for membrane C3 H6 /C3 H8 separation is reported. A platform COF is synthesized from 5,5'-diamino-2,2'-bipyridine and 2-hydroxybenzene-1,3,5-tricarbaldehyde. This COF possesses a porous 2D structure with high crystallinity. Cu(I) is coordinated to bipyridyl moieties in the COF framework, acting as recognizable sites for C3 H6 gas, as shown by the adsorption measurements. Cu(I) COF is blended with 6FDA-DAM polymer to yield MMMs. This COF MMM exhibits selective and permeable separation of C3 H6 from C3 H8 (C3 H6 permeability of 44.7 barrer, C3 H6 /C3 H8 selectivity of 28.1). The high porosity and Cu(I) species contribute to the great improvement of separation performance by virtue of 2.3-fold increase in permeability and 2.2-fold increase in selectivity compared to pure 6FDA-DAM. The superior performance to those of most relevant reported MMMs demonstrates that the Cu(I) coordinated COF is an excellent candidate material for C3 H6 separation membranes.

Efficient butyrate production from rice straw in an optimized cathodic electro-fermentation process.

Butyrate production from renewable biomass shows great potential against climate change and over-consumption of fossil fuels. Herein, key operational parameters of a cathodic electro-fermentation (CEF) process were optimized for efficient butyrate production from rice straw by mixed culture. The cathode potential, controlled pH and initial substrate dosage were optimized at -1.0 V (vs Ag/AgCl), 7.0 and 30 g/L, respectively. Under the optimal conditions, 12.50 g/L butyrate with yield of 0.51 g/g-rice straw were obtained in batch-operated CEF system. In fed-batch mode, butyrate production significantly increased to 19.66 g/L with the yield of 0.33 g/g-rice straw, but 45.99% butyrate selectivity still needs to be improved in future. Enriched butyrate producing bacteria (Clostridium cluster XIVa and IV) with proportion of 58.75% on the 21st day of the fed-batch fermentation, contributed to the high-level butyrate production. The study provides a promising approach for efficient butyrate production from lignocellulosic biomass.

Ultramicroporous Covalent Organic Framework Nanosheets with Functionality Pair for Membrane C2 H2 /C2 H4 Separation.

Gas separation efficiency of covalent organic framework (COF) membrane can be greatly elevated through precise functionalization. A pair-functionalized COF membrane of 1,3,5-triformylphloroglucinol (TP) and isoquinoline-5,8-diamine (IQD) monomers in two and three nodes is designed and synthesized. TP-IQD is crystallized in a two-dimensional structure with a pore size of 6.5 Šand a surface area of 289 m2 g-1 . This COF possesses N-O paired groups which cooperatively interact with C2 H2 instead of C2 H4 . TP-IQD nanosheets of ≈10 µm in width and ≈4 nm in thickness are prepared by mechanical exfoliation; they are further processed with 6FDA-ODA polymer into a hybrid membrane. High porosity and functionality pair of TP-IQD offer the membrane with significantly increased C2 H2 permeability and C2 H2 /C2 H4 selectivity which are 160 % and 430 % higher of pure 6FDA-ODA. The boosted performance demonstrates high efficiency of the pair-functionality strategy for the synthesis of separation-led COFs.

Accelerated catalytic oxidation of dissolved manganese(II) by chlorine in the presence of in situ-growing 3D manganese(III)/(IV) oxide nanosheet assembly in zeolite filter.

Manganese contamination is ubiquitous in ground water. Water eutrophication also exaggerates manganese release and contamination in surface water. However, conventional manganese(II) removal process through sand filter is low-efficiency and long-term ripening. Manganese exceeding standard is still a bottleneck issue for drinking water plants. To provide a quick-setup and low-cost means, we invented an accelerated catalytic oxidation filtration process through porous zeolite filter with dynamically coating of manganese oxide nanocatalysts. In dynamic filtration process, the addition of chlorine less than redox stoichiometric consumption can efficiently remove dissolved manganese(II) from contaminated tap water, ground water and Songhua river water. Characterization results showed that a continuous manganese(III)/(IV) oxide nanosheet catalyst was dynamically in situ-growing and assembled into 3D porous superstructure in the reactive Zeolite@MnOx(s) filter. Active Mn(III) species on the edges of MnOx(s) nanosheets were dynamically generated and transferred into stable Mn(IV) species on the layer-structured surface. The cycling transformation of manganese(III)/(IV) species was responsible for the accelerated catalytic oxidation of dissolved manganese(II) by chlorine. Without process changes in drinking water plant, the porous Zeolite@MnOx(s) media could be feasibly integrated onto the existing sand filtration tanks for emergence handling of manganese(II) contamination. This novel reactive Zeolite@MnOx(s) filter with higher hydraulic conductivity provides a high-efficiency, scalable and low-cost technique for the manganese(II) removal from various of water environments.

Enhanced Water Permeability and Antifouling Property of Coffee-Ring-Textured Polyamide Membranes by In Situ Incorporation of a Zwitterionic Metal-Organic Framework.

Modulation of the polyamide structure is critically important for the reverse-osmosis performance of thin-film composite (TFC) membranes in the field of water reuse and desalination. Herein, zwitterionic nanoparticles of zeolitic imidazolate framework-8 (PZ@ZIF-8) were fabricated and incorporated into the polyamide active layer through the interfacial polymerization method. A hydrophilic, zwitterionic coffee-ring structure was formed on the surface of polyamide thin-film nanocomposite (TFN) membranes due to the adjusted diffusion rate of m-phenylenediamine (MPD) from the aqueous phase into the organic phase during the interfacial polymerization process. Surface characterization demonstrated that the coffee-ring structure increased the amounts of water transport channels on the membrane surface and the intrinsic pores of PZ@ZIF-8 maintained the salt rejection. Antifouling and bactericidal activities of TFN membranes were enhanced remarkably owing to the bacterial-"defending" and bacterial-"attacking" behaviors of hydrophilic and zwitterionic groups from PZ@ZIF-8 nanoparticles. This work would provide a promising method for the application of MOFs to enhance the bio-/organic-fouling resistance of TFN membranes with high water permeation and salt rejection.

Catalytic degradation of micropollutant by peroxymonosulfate activation through Fe(III)/Fe(II) cycle confined in the nanoscale interlayer of Fe(III)-saturated montmorillonite.

Low cost, green, regenerable catalyst for persulfate activation is the popularly concerned topic for the degradation of persistent organic micropollutants in drinking water. In this work, natural montmorillonite (MMT) saturated with Fe(III) ions was used to activate peroxymonosulfate (PMS) for the degradation of atrazine in raw drinking water. Results showed that the adsorption of atrazine was quickly completed within 1 min and the percentage degradation was finally increased up to 94.1% in 60 min. The d001-spacing of MMT was enlarged to 2.91 nm at the most by Fe(III) saturation. Atrazine was adsorbed into the nanoscale interlayer of Fe(III)-saturated montmorillonite (Fe-MMT), where the Fe(III)/Fe(II) cycle was sustainably realized through the accelerated transformation of electrons between Fe(III) and PMS. Meanwhile, the in-situ generated Fe(II) accelerated the decomposition of PMS to further proceed the degradation of atrazine through the oxidation of HO• and SO4•- radicals. This nanoconfined effect of PMS activation by Fe(III) was further confirmed through the degradation of various micropollutants in the backgrounds of river water. The selective catalytic oxidation of micropollutants through PMS activation was attributed to the 2D mesoporous structure of Fe-MMT, inhibiting the interlayer adsorption of larger molecular backgrounds (humic acids etc.). Fe(III)-saturated montmorillonite (Fe-MMT) provided a feasible and scalable method of PMS activation by Fe(III) for the degradation of micropollutants in drinking water.

Strong improvement of nanofiltration performance on micropollutant removal and reduction of membrane fouling by hydrolyzed-aluminum nanoparticles.

Increasing attention has been focused on the removal of micropollutants from contaminated drinking source water. However, low rejection efficiency and membrane fouling still inhibit further application of nanofiltration membrane in this field. Interesting results were found that the residual hydrolyzed-aluminum nanoparticles from supernatant after coagulation and sedimentation strongly improved the nanofiltration performance for micropollutant removal. A simulated raw water containing humic acids, micropollutants and kaolinite clay was employed to investigate the factors of water matrix affecting the nanoparticle-enhanced nanofiltration for micropollutant removal. Results of experiments showed that these hydrolyzed-aluminum nanoparticles easily induced the aggregation of bisphenol-A (BPA) and humic acids in the supernatant. The enhancement of BPA removal was mainly attributed to the repelling interaction between the Al-BPA-DOC complexity and in situ-modified membrane surface during nanofiltration. 'This in situ surface modification by the hydrolyzed-aluminum nanoparticles improved membrane hydrophilicity, roughness and positively-charging capacity. For the treatment of River Songhua water spiked with micropollutant, the percentage removal of BPA was improved to be 88.5%, much more than the case of single nanofiltration without coagulation (60.7%). Meanwhile, the membrane fouling was reduced by 2.13 times than the case of single nanofiltration without the dynamically deposited-layer of nanoparticles. This in situ modification of nanofiltration membrane by hydrolyzed-aluminum nanoparticles achieved excellent removal efficiency for micropollutants from River Songhua water background.

RPL34-AS1 functions as tumor suppressive lncRNA in esophageal cancer.

Ribosomal protein L34 antisense RNA 1 (RPL34-AS1) is novel long non-coding RNA, and was found to be down-regulated in colorectal cancer and gastric cancer. The role of RPL34-AS1 was still unknown in esophageal cancer. In our study, we found RPL34-AS1 expression levels in esophageal cancer tissue and specimens and cell lines were lower than in adjacent normal tissue specimens and normal esophageal cell line, respectively. In addition, esophageal cancer patients with Ⅲ-Ⅳ, T3-T4 or positive lymph node metastasis had lower RPL34-AS1expression levels than esophageal cancer patients with Ⅰ-Ⅱ, T1-T2 or negative lymph node metastasis, respectively. In survival analysis suggested esophageal cancer patients with low RPL34-AS1 expression had short overall survival than those with high RPL34-AS1 expression. Our in vitro experiments suggested RPL34-AS1 inhibits esophageal cancer cell proliferation, migration and invasion through down-regulating RPL34 expression. In conclusion, RPL34-AS1 functions as tumor suppressor in esophageal cancer.

Enhanced permeability and fouling-resistant capacity of poly(vinylidene fluoride) ultrafiltration membrane based on the PPG-co-PEG-co-PPG copolymer with two hydrophobic terminals and one hydrophilic intermediate.

A simple and efficient route was used to prepare an amphiphilic copolymer (poly(propylene glycol)-co-poly(ethylene glycol)-co-poly(propylene glycol)) (PPG-co-PEG-co-PPG) by one-pot polymerization reaction. This copolymer was used as the hydrophilic additive in preparation of poly(vinylidene fluoride) (PVDF) ultrafiltration membranes via immersion-precipitation process. Surface characteristics of the membranes were confirmed by contact angle measurements, zeta potential, attenuated total reflectance Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, scanning electron microscopy and atomic force microscopy. During filtration experiments, the modified membranes showed better permeation and antifouling performances compared to PVDF membranes with bovine serum albumin, sodium alginate and yeast. After hydraulic stirring cleaning with deionized water, water flux recovery and rejection ratio of the modified membranes were higher than those of pristine PVDF membrane, and the flux recovery ratio was maximized at 94.29%. It was suggested that PPG-co-PEG-co-PPG copolymer was anchored in the PVDF membrane through the two hydrophobic ends of PPG blocks, while the hydrophilic intermediate of the PEG block segregated onto the membrane or pore surface during the membrane preparation process. The synthesized method of amphiphilic PPG-co-PEG-co-PPG copolymer paved a novel way to solve the problems of less compatibility between the copolymer and membrane matrix and instability with water molecules in the ultrafiltration process.

Tough, sticky and remoldable hydrophobic association hydrogel regulated by polysaccharide and sodium dodecyl sulfate as emulsifiers.

Hydrophobic association hydrogels have been extensively studied during the past decades. However, the fracture stress of hydrophobic association hydrogels obtained with anionic surfactants (such as sodium dodecyl sulfate) achieved hundreds of Pascal. In this investigation, combined surfactants consisting of polysaccharide (gum arabic) and sodium dodecyl sulfate were utilized to stabilize hydrogels with high fracture stress of more than 1 MPa. Moreover, the hydrogels exhibited excellent self-healing capacity and remoldable behavior without any stimulation. Simultaneously, the hydrogels demonstrated an adhesive behavior for various solid substrates including polytetrafluoroethylene, plastics, rubbers, glasses, metals and woods. The hydrogel with toughness, self-healing, stickiness and remoldable properties would be expected to be applied in the medical fields, such as wound dressing, medical electrodes, tissue adhesives and portable equipment.