Locking Patterned Carbon Nanotube Cages by Nanofibrous Mats to Construct Cucurbituril[n]-Based Ultrapermselective Dye/Salt Separation Membranes.

Surface patterning is a promising strategy to overcome the trade-off effect of separation membranes. Herein, a bottom-up patterning strategy of locking micron-sized carbon nanotube cages (CNCs) onto a nanofibrous substrate is developed. The strongly enhanced capillary force triggered by the abundant narrow channels in CNCs endows the precisely patterned substrate with excellent wettability and antigravity water transport. Both are crucial for the preloading of cucurbit[n]uril (CB6)-embeded amine solution to form an ultrathin (∼20 nm) polyamide selective layer clinging to CNCs-patterned substrate. The CNCs-patterning and CB6 modification result in a 40.2% increased transmission area, a reduced thickness, and a lowered cross-linking degree of selective layer, leading to a high water permeability of 124.9 L·m-2 h-1 bar-1 and a rejection of 99.9% for Janus Green B (511.07 Da), an order of magnitude higher than that of commercial membranes. The new patterning strategy provides technical and theoretical guidance for designing next-generation dye/salt separation membranes.

Biocompatible curcumin coupled nanofibrous membrane for pathogens sterilization and isolation.

Airborne transmission of pathogens is the most probable cause for the spread of respiratory diseases, which can be intercepted by personal protective equipment such as masks. In this study, an efficient antiviral personal protective filter was fabricated by coupling the biocompatible curcumin (CCM) with nanofibrous polytetrafluoroethylene (PTFE) membrane. The CCM extracted from plants was first dissolved in acidified ethanol at a certain pH and temperature to optimize its loading concentration, antiviral activation, and binding forces on the polyethylene terephthalate (PET) support to form a pre-filtration layer at the front section of the filter. Ultrathin PTFE membrane was then fabricated on the antibacterial-antiviral PET support (A-A PET) by controllable heating lamination. This functional layer of the filter exhibits good gas permeance (3423.6 m3/(m2·h·kPa)) and ultrafine particles rejection rate (>98.79%). Moreover, the obtained A-A filter exhibit a high antibacterial rate against a variety of bacteria (E. coli, B. subtilis, A. niger, and Penicillium were 99.84%, 99.02%, 93.60%, 95.23%, respectively). Forthwith virucidal (SARS-CoV-2) efficiency of the A-A filter can reach 99.90% for 5 min. The filter shows good stability after 10 heating cycles, demonstrating its reusability.

Encapsulated Polyethyleneimine Enables Synchronous Nanostructure Construction and In Situ Functionalization of Nanofiltration Membranes.

Highly permselective nanostructured membranes are desirable for the energy-efficient molecular sieving on the subnanometer scale. The nanostructure construction and charge functionalization of the membranes are generally carried out step by step through the conventional layer-by-layer coating strategy, which inevitably brings about a demanding contradiction between the permselective performance and process efficiency. For the first time, we report the concurrent construction of the well-defined molecular sieving architectures and tunable surface charges of nanofiltration membranes through precisely controlled release of the nanocapsule decorated polyethyleneimine and carbon dioxide. This novel strategy not only substantially shortens the fabrication process but also leads to impressive performance (permeance up to 37.4 L m-2 h-1 bar-1 together with a rejection 98.7% for Janus Green B-511 Da) that outperforms most state-of-art nanofiltration membranes. This study unlocks new avenues to engineer next-generation molecular sieving materials simply, precisely, and cost efficiently.

Meltblown fabric vs nanofiber membrane, which is better for fabricating personal protective equipments.

The coronavirus disease 2019 (COVID-19) pandemic has led to a great demand on the personal protection products such as reusable masks. As a key raw material for masks, meltblown fabrics play an important role in rejection of aerosols. However, the electrostatic dominated aerosol rejection mechanism of meltblown fabrics prevents the mask from maintaining the desired protective effect after the static charge degradation. Herein, novel reusable masks with high aerosols rejection efficiency were fabricated by the introduction of spider-web bionic nanofiber membrane (nano cobweb-biomimetic membrane). The reuse stability of meltblown and nanofiber membrane mask was separately evaluated by infiltrating water, 75% alcohol solution, and exposing under ultraviolet (UV) light. After the water immersion test, the filtration efficiency of meltblown mask was decreased to about 79%, while the nanofiber membrane was maintained at 99%. The same phenomenon could be observed after the 75% alcohol treatment, a high filtration efficiency of 99% was maintained in nanofiber membrane, but obvious negative effect was observed in meltblown mask, which decreased to about 50%. In addition, after long-term expose under UV light, no filtration efficiency decrease was observed in nanofiber membrane, which provide a suitable way to disinfect the potential carried virus. This work successfully achieved the daily disinfection and reuse of masks, which effectively alleviate the shortage of masks during this special period.

Highly Ordered Nanochannels in a Nanosheet-Directed Thin Zeolite Nanofilm for Precise and Fast CO2 Separation.

Precise molecular and ion separations depend largely on the size and uniformity of the nanochannels in a defect-free microporous nanofilm. Ordered and perpendicular nanochannels with uniform pore size are assembled into a continuous and defect-free film by a "gel nuclei-less" route. The ultrathin (<50 nm) zeolite nanosheets seeding layer induces the formation of defect-free zeolite nanofilms (500-800 nm) with preferential [100] orientation well-aligned to the transport pathway. The large-area and thin silicoaluminophosphate-34 (SAPO-34) nanofilm consisting of uniform and straight nanochannels shows a milestone CO2 permeance of ≈1.0 × 10-5 mol (m2 s Pa)-1 and high CO2 /CH4 and CO2 /N2 selectivities of 135 and 41 in equimolar binary mixtures at room temperature and 0.2 MPa feed pressure, respectively. These results suggest that highly oriented and thin SAPO-34 nanofilms prepared from nanosheets might have great potential for CO2 capture from natural gas, biogas, and flue gas.

Study on the treatment of simulated azo dye wastewater by a novel micro-electrolysis filler.

A new type of iron-copper-carbon (Fe-Cu-C) ternary micro-electrolysis filler was prepared with a certain proportion of iron powder, activated carbon, bentonite, copper powder, etc. The effect of the new type of micro-electrolysis filler on the simulated methyl orange dye wastewater was studied. The effects of various operational parameters, such as reaction time, initial pH value, aeration rate, filler dose and reaction temperature, on the degradation rate of methyl orange were studied to determine the optimum treatment conditions, and the micro-electrolysis filler was characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD). The experimental results show that the degradation rate of 220 mL of simulated dye wastewater with a concentration of 100 mg/L reached 93.41% ± 2.94% after 60 mL/min of aeration, with an initial pH = 2, a dose of 45 g and 125 minutes of reaction at room temperature. The new micro-electrolysis filler has a high degradation rate for methyl orange solution, which is attributed to the iron and activated carbon particles sintered into an integrated structure, which makes the iron and carbon difficult to separate and affects the galvanic cell reaction. The addition of copper also greatly increases the transmission efficiency of electrons, which promotes the reaction. In addition, the surface iron is consumed, the adjacent carbon is stripped layer by layer, and the new micro-electrolytic filler does not easily passivate and agglomerate during its use.

[Preliminary study on RC membrane permeability and mechanism of seven traditional Chinese medicine alkaloids such as berberine].

In order to analyze the law of membrane permeation of different alkaloids, seven traditional Chinese medicine alkaloids with different parent nucleus and substituent structures, including berberine, palmatine, sinomenine, matrine, oxymatrine, sophoridine, and tetrandrine, were prepared into the simulated solution with same molar concentration, and the membrane penetrating experiments with membrane RC1K and membrane RC5K were carried out. The dynamic transmittance, the total transmittance and the total adsorption rate of each substance were measured, and the scanning electron microscopy (SEM) images of the membrane surface before and after the membrane experiment were considered to predict and analyze the reason of differences in dynamic transmittance of different alkaloids. The results showed that there were significant differences in the dynamic transmittance of the chemical constituents of different alkaloids during penetrating the two membranes. The contamination degree on the surface of the membrane material was also different. The transmittance of the same compound through the RC5K membrane was larger than that through RC1K membrane. Within a certain range, the smaller the pore size of the membrane, the better the selective screening effect on the chemical constituents of traditional Chinese medicine. All the membrane surfaces were less polluted. The difference in transmittance between different substances on the same membrane showed a positive correlation with the difference in structural complexity, providing an experimental basis for the surface modification design in contamination control of membrane materials. In the design of membrane modified material, the surface properties of the membrane can be improved by grafting different polar groups, thereby changing the adsorption characteristics of the membrane surface. The pore size was designed accordingly to achieve the high transmittance and low pollution of the corresponding compounds.

Template-Free Synthesis of High Dehydration Performance CHA Zeolite Membranes with Increased Si/Al Ratio Using SSZ-13 Seeds.

Pervaporation is an energy-efficient alternative to conventional distillation for water/alcohol separations. In this work, a novel CHA zeolite membrane with an increased Si/Al ratio was synthesized in the absence of organic templates for the first time. Nanosized high-silica zeolite (SSZ-13) seeds were used for the secondary growth of the membrane. The separation performance of membranes in different alcohol-aqueous mixtures was measured. The effects of water content in the feed and the temperature on the separation performance using pervaporation and vapor permeation were also studied. The best membrane showed a water/ethanol separation factor above 100,000 and a total flux of 1.2 kg/(m2 h) at 348 K in a 10 wt.% water-ethanol mixed solution. A membrane with high performance and an increased Si/Al ratio is promising for the application of alcohol dehydration.

Revolutionizing osteoarthritis treatment: How mesenchymal stem cells hold the key.

Osteoarthritis (OA) is a multifaceted disease characterized by imbalances in extracellular matrix metabolism, chondrocyte and synoviocyte senescence, as well as inflammatory responses mediated by macrophages. Although there have been notable advancements in pharmacological and surgical interventions, achieving complete remission of OA remains a formidable challenge, oftentimes accompanied by significant side effects. Mesenchymal stem cells (MSCs) have emerged as a promising avenue for OA treatment, given their ability to differentiate into chondrocytes and facilitate cartilage repair, thereby mitigating the impact of an inflammatory microenvironment induced by macrophages. This comprehensive review aims to provide a concise overview of the diverse roles played by MSCs in the treatment of OA, while elucidating the underlying mechanisms behind these contributions. Specifically, the roles include: (a) Promotion of chondrocyte and synoviocyte regeneration; (b) Inhibition of extracellular matrix degradation; (c) Attenuating the macrophage-induced inflammatory microenvironment; (d) Alleviation of pain. Understanding the multifaceted roles played by MSCs in OA treatment is paramount for developing novel therapeutic strategies. By harnessing the regenerative potential and immunomodulatory properties of MSCs, it may be possible to devise more effective and safer approaches for managing OA. Further research and clinical studies are warranted to optimize the utilization of MSCs and realize their full potential in the field of OA therapeutics.

Highly porous metal oxide networks of interconnected nanotubes by atomic layer deposition.

Mesoporous metal oxide networks composed of interconnected nanotubes with ultrathin tube walls down to 3 nm and high porosity up to 90% were fabricated by atomic layer deposition (ALD) of alumina or titania onto templates of swelling-induced porous block copolymers. The nanotube networks possessed dual sets of interconnected pores separated by the tube wall whose thickness could be finely tuned by altering ALD cycles. Because of the excellent pore interconnectivity and high porosity, the alumina nanotube networks showed superior humidity-sensing performances.

[Correlation between plasma aldosterone concentration and left ventricular structure in hypertensive patients].

OBJECTIVE: To observe the correlation between plasma aldosterone concentration (PAC) and left ventricular structure in hypertensive patients. METHODS: A total of 201 hypertensive patients [117 male, aged from seventeen to sixty eight years old, mean (43.6 ± 10.2) years] were included. All subjects underwent echocardiography examination for measurement of left ventricular end-diastolic dimension (LVEDD), LV posterior wall thickness (LVPWT), interventricular septum thickness (IVST) and LV mass index (LVMI). Plasma PAC was also measured at three postural positions. According to the sitting PAC, subjects were divided into high aldosterone group (PAC ≥ 120 ng/L, n = 83) and normal aldosterone (PAC < 120 ng/L, n = 118) group. Bivariate correlation and multiple stepwise regression analysis were performed to analyze the correlation between left ventricular structure parameters and PAC. RESULTS: IVST, LVPWT values were significantly higher in the increased PAC group than that in normal PAC group [ (10.4 ± 1.0) mm vs. (10.9 ± 1.8) mm, (10.1 ± 0.7) mm vs.(10.4 ± 1.5) mm, all P < 0.05]. Bivariate correlation analysis showed that PAC was weakly correlated with IVST (r = 0.190, P < 0.05) , while was not correlated to LVMI, LVPWT and LVEDD (all P > 0.05). Multiple linear stepwise regression analysis showed that PAC was positively correlated with IVST and LVPWT (ß = 0.206 and ß = 0.241, respectively, all P < 0.05), but was not correlated to LVMI and LVEDD (all P > 0.05). CONCLUSION: PAC is positively correlated with IVST and LVPWT in hypertensive patients.

Laccase encapsulation immobilized in mesoporous ZIF-8 for enhancement bisphenol A degradation.

Endocrine disruptors (EDCs) such as bisphenol A (BPA) have many adverse effects on environment and human health. Laccase encapsulation immobilized in mesoporous ZIF-8 was prepared for efficient degradation of BPA. The ZIF-8 (PA) with highly ordered mesopores was synthesized using trimethylacetic acid (PA) as a template agent. On account of the improvement of skeletal stability by cross-linking agent glutaraldehyde, ZIF-8 (PA) realized laccase (FL) immobilization within the mesopores through encapsulation strategy. By replacing the template agent, the effect of pore size on the composite activity and immobilization efficiency by SEM characterization and kinetic analysis were investigated. Based on the physical protection of ZIF-8(PA) on laccase, as well as electrostatic interactions between substances and changes in surface functional groups (e.g. -OH, etc.), multifaceted enhancement including activity, stability, storability were engendered. FL@ZIF-8(PA) could maintain high activity in complex systems at pH 3-11, 10-70 °C or in organic solvent containing system, which exhibited an obvious improvement compared to free laccase and other reported immobilized laccase. Combined with TGA, FT-IR and Zeta potential analysis, the intrinsic mechanism was elaborated in detail. On this basis, FL@ZIF-8(PA) achieved efficient removal of BPA even under adverse conditions (removal rates all above 55% and up to 90.28%), and was suitable for a wide range of initial BPA concentrations. Combined with the DFT calculations on the adsorption energy and differential charge, the mesoporous could not only improve the enrichment performance of BPA on ZIFs, but also enhance the interaction stability. Finally, FL@ZIF-8(PA) was successfully applied to the degradation of BPA in coal industry wastewater. This work provides a new and ultra-high performances material for the organic pollution treatment in wastewater.

In Situ Synthesis of Cation-Free Zirconia-Supported Zeolite CHA Membranes for Efficient CO2/CH4 Separation.

Cation-free zirconosilicate zeolite CHA and thin zirconia-supported membranes were in situ synthesized in a fluoride-free gel for the first time. The usage of the ZrO2/Al2O3 composite support inhibited the transportation of aluminum from the support into zeolite membranes. No fluorite source was used for the synthesis of cation-free zeolite CHA membranes, indicating the green property of the synthesis. The thickness of the membrane was only 1.0 µm. The best cation-free zeolite CHA membrane prepared by the green in situ synthesis displayed a high CO2 permeance of 1.1 × 10-6 mol/(m2 s Pa) and CO2/CH4 selectivity of 79 at 298 K and 0.2 MPa pressure drop for an equimolar CO2/CH4 mixture.

One-Step Scalable Fabrication of Highly Selective Monolithic Zeolite MFI Membranes for Efficient Butane Isomer Separation.

The reproducible fabrication of large-area zeolite membranes for gas separation is still a great challenge. We report the scalable fabrication of high-performance zeolite MFI membranes by single-step secondary growth on the 19-channel alumina monoliths for the first time. The packing density and mechanical strength of the monolithic membranes are much higher for these than for tubular ones. Separation performance of the monolithic membranes toward the butane isomer mixture was comparably evaluated using the vacuum and Wicke-Kallenbach modes. The n-butane permeances and n-butane/i-butane separation factors for the three membranes with an effective area of ∼84 cm2 were >1.0 × 10-7 mol (m2 s Pa)-1 and >50 at 343 K for an equimolar n-butane/i-butane mixture, respectively. We succeeded in scaling up the membrane synthesis with the largest area of 270 cm2 to date which has 1.3 times the area of an industrial 1 m long tubular membrane. Monolith supported zeolite MFI membranes show great potential for industrial n-butane/i-butane separation.

Spatially confined growth of carbon nanotubes in the pore channels of microporous ceramic supports with improved filtration efficiency.

Carbon nanotubes (CNTs) with high degrees of uniformity, orientation and controlled dimensions on porous supports are highly desirable for various applications such as separation of O/W emulsions and air purification. In this work, CNTs were fabricated on silicon carbide (SiC) porous supports with different porosities and pore sizes by chemical vapor deposition (CVD). The growth processes of CNTs on the surface and in the pore channels of the SiC support were studied in detail. Based on microstructural characterization by SEM, Raman spectroscopy and TEM, it was found that these CNTs grown in the pore channels of SiC supports had a higher degree of orientation and purity than those grown on the surface due to the spatially confined effect. The growth processes of various types of CNTs on the microporous supports were proposed, which were further verified by CNTs with different steric configurations (S-CNTs and VACNTs) and on Al2O3 porous supports. Moreover, the contribution of CNTs in the pore channels to the filtration efficiency was demonstrated in oil-water emulsion separation and particle removal in air. This work provides significant guidance for the preparation and filtration application of CNTs on porous materials.

Pollution and Cleaning of PDMS Pervaporation Membranes after Recovering Ethyl Acetate from Aqueous Saline Solutions.

The removal of volatile organic compounds (VOCs) from wastewater containing nonvolatile salts has become an important and interesting case of the application of the pervaporation (PV) process. The aim of this study was to evaluate the influence of salts on the PV removal of ethyl acetate from wastewater using a polydimethylsiloxane (PDMS) membrane. The fouled membrane was then characterized via scanning electron microscopy-energy-dispersive X-ray analysis (SEM-EDX) to investigate salt permeation. The membrane backflushing process was carried out by periodically flushing the permeate side of the tubular membrane. The results demonstrated that salts (NaCl and CaCl2) could permeate through the PDMS membrane and were deposited on the permeate side. The presence of salts in the feed solution caused a slight increase in the membrane selectivity and a decrease in the permeate flux. The flux decreased with increasing salt concentration, and a notable effect occurred at higher feed-salt concentrations. A permeate flux of up to 98.3% of the original flux was recovered when the permeation time and backflushing duration were 30 and 5 min, respectively, indicating that the effect of salt deposition on flux reduction could be mitigated. Real, organic, saline wastewater was treated in a pilot plant, which further verified the feasibility of wastewater PV treatment.

Silicon carbide microfiltration membranes for oil-water separation: Pore structure-dependent wettability matters.

Both the pore size and surface properties of silicon carbide (SiC) membranes are demonstrated to significantly affect their separation efficiency when used for oily water treatment. However, the potential influences of open porosity together with the pore size of SiC membranes on their surface properties and oil-water separation performance have rarely been investigated. In this work, porous SiC ceramic membranes with tunable open porosity and pore size were purposely prepared and selected to systematically study the effect of pore structure-dependent wettability on the oil-water separation performance. The measured pure water flux of selected membranes as a function of open porosity (34-48%) and pore size (0.43-0.67 µm) was well-fitted by using a modified H-P equation. Interestingly, the hydrophilicity of SiC membranes was improved with the increase in open porosity and pore size, as evidenced by the gradually decreased dynamic water contact angle and underwater adhesion of oil droplets. Further, the open porosity of SiC membranes was found to contribute more to the improved surface wettability. As a result, the stable flux of SiC membranes in oil-in-water (O/W) emulsions was increased by 24% with the increased open porosity while the oil rejection rate remained above 90%. This work quantitatively reveals the contributions of the pore structure to the surface wettability of ceramic membranes, and thus provides an effective pathway to improve their performance in oil-water separation.

Dynamic Imaging Changes of COVID-19 Pneumonia at Different Stages.

INTRODUCTION: To investigate the Computed Tomography (CT) imaging characteristics and dynamic changes of COVID-19 pneumonia at different stages. METHODS: Forty-six patients infected with COVID-19 who had chest CT scans were enrolled, and CT scans were performed 4-6 times with an interval of 2-5 days. RESULTS: At the early stage (n=25), ground glass opacity was presented in 11 patients (11/25 or 44.0 %) and ground glass opacity mixed with consolidation in 13 (13/25 or 52.0 %) in the lung CT images. At the progressive stage (n=38), ground glass opacity was presented in only one patient (1/38 or 2.6 %) and ground glass opacity mixed with consolidation in 33 (33/38 or 86.8 %). In the early improvement stage (n=38), the imaging presentation was ground glass opacity alone in three patients (3/38 or 7.9 %) and ground glass opacity mixed with consolidation in 34 (34/38 or 89.5 %). In the late improvement (absorption) stage (n=33), the primary imaging presentation was ground glass presentation in eight patients (8/33 or 24.2 %) and ground glass opacity mixed with consolidation in 23 (23/33 or 69.7 %). The lesion reached the peak at 4-16 days after disease onset, and 26 (26/38 or 68.4 %) patients reached the disease peak within ten days. Starting from 6 to 20 days after onset, the disease began to be improved, with 30 (30/38 or 78.9 %) patients being improved within 15 days. CONCLUSION: COVID-19 pneumonia will progress to the peak stage at a mediate time of seven days and enter the improvement stage at twelve days. Computed tomography imaging of the pulmonary lesion has a common pattern from disease onset to improvement and recovery and provides important information for evaluation of the disease course and treatment effect.

Nanoarchitectonics for Electrospun Membranes with Asymmetric Wettability.

Membranes with asymmetric wettability have attracted significant interest by virtue of their unique transport characteristics and functionalities arising from different wetting behaviors of each membrane surface. The cross-sectional wettability distinction enables a membrane to realize directional liquid transport or multifunction integration, resulting in rapid advance in applications, such as moisture management, fog collection, oil-water separation, and membrane distillation. Compared with traditional homogeneous membranes, these membranes possess enhanced transport performance and higher separation efficiency owing to the synergistic or individual effects of asymmetric wettability. This Review covers the recent progress in fabrication, transport mechanisms, and applications of electrospun membranes with asymmetric wettability and provides a perspective on future development in this important area.

Treatment of vegetable oily wastewater using an integrated microfiltration-reverse osmosis system.

Vegetable oil processing plants and catering trade often generate a large amount of oil-containing wastewater, which causes serious environmental problems. The objective of this work was to explore the feasibility of vegetable oil wastewater treatment with an integrated microfiltration-reverse osmosis (MF-RO) process. The influence of operational parameters on the separation behaviors were investigated in MF process. In MF continuous process the steady flux was around 90 (L/m(2) h) when the concentrated multiple reached 16, and the oil content in permeate was less than 12 mg/L. In the RO continuous process, antifouling membrane was used to treat permeate from the ceramic membrane process in order to improve the water quality. The RO process had a permeate flux of 24 (L/m(2) h) and water recovery rate of 95%. The permeate from the RO stage was free of oil, and its TOC and conductivity were less than 0.6 mg/L and 50 micros/cm, respectively. The results demonstrated that the two stage membrane process combining MF and RO is highly efficient in the treatment of oil-containing wastewater.