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Dibenzo-24-crown-8 (DB24C8)-bearing copolymers were synthesized by radical copolymerization using a DB24C8-carrying acrylamide derivative and N-isopropylacrylamide monomers. The cloud point of the resulting copolymers changed in aqueous solution in the presence of cesium ions. In addition, the 1H NMR signals of DB24C8-bearing copolymers shifted in the presence of alkali metal. This shift was more pronounced following the addition of Cs+ compared to Rb+, K+, Na+, and Li+ ions due to recognition of the Cs+ ion by DB24C8. [ABSTRACT FROM AUTHOR]

Water and energy shortages are interdependent major worldwide issues that cannot be disregarded. In this work, graphene and BaTiO3 are used to synergistically facilitate the self‐assembly of the β‐phase that is known to induce the piezoelectric properties of the polyvinylidene fluoride (PVDF). This leads to a PVDF/graphene‐BaTiO3 nanocomposite with a unique capability of integrating Phra Phrom‐like four functions into one single asymmetric membrane: i) solar evaporation, ii) power generation, iii) piezo‐photodegradation, and iv) self‐cleaning/monitoring for environmental remediation and resources regeneration. The high heat accumulation capability and piezoelectric performance of the membrane enable it to simultaneously achieve a water production rate of 0.99 kgm−2h−1, in compliance with WHO standards, and a maximum power output of 5.73 Wm−2 in simulated natural environments. Upon subjecting the membranes to environmental cleaning, they not only show a 93% dye degradation rate due to the synergistic effect of piezoelectricity and photocatalysis but also resolve the membrane fouling issue, exhibiting ≈200% resistance change compared to the static state. The successful integration of these four functions into one membrane shows the great potential of this work toward a more sustainable and viable water and energy production approach. [ABSTRACT FROM AUTHOR]

The article discusses a retrospective, cross-sectional study on the prevalence of carotid artery stenosis (CAS) in southern China. It explores how the study was conducted which involved 862 inpatients with stroke or transient ischemic attacks and underwent certain laboratory examinations to determine the prevalence of severe CAS of bilateral carotid arteries. The results reportedly revealed that the prevalence of severe CAS is lower in south China compared with the north.

The non-solvent induced phase separation (NIPS) process applied to polysulfone (PSf) casting solutions traditionally leads to the formation of membranes decorated with large macrovoids in their cross-section on top of which lies a dense skin offering a significant resistance to flow. Macrovoids, are considered weak points. They are prone to compaction leading to poor filtration performance over time. Here, we used 2-pyrrolidone (2P) to prepare skin-free PSf membranes by NIPS, and studied the effect of water as an additive to help suppress the formation of macrovoids. The surface images showed the presence of multiple pores while the cross-section images exhibited the successful suppression of macrovoids. The latter was attributed to the enhancement of the solution viscosity causing the mass transfer kinetics to be slowed down, consequently affecting the demixing rates. Moreover, the rheological behavior of the casting solutions revealed that high degree of chain entanglement helped mitigate macrovoid formation. Using 2P as the solvent for PSf permitted the retention of interconnected pores from the top surface, due to the high viscosity of the solution which prevented coarsening. The high porosity (>75%) and large pores (>0.3 μm) of the PSf membranes were still maintained. The permeability of membranes was maintained after suppressing the macrovoids but their mechanical attributes were improved. The feasibility of utilizing water to eliminate macrovoid growth was further validated when applied to other PSf/solvent systems which showed similar trends in the SEM images. These results imply that water as a casting solution additive can provide a highly cost-effective and simple strategy to obtain macrovoid-free p olysulfone membranes. [Display omitted] • Skin-free macrovoid-free polysulfone membranes were prepared by the NIPS process. • Interconnected pores decorate the entire cross-section of the PSf membranes. • Macrovoids were suppressed by adding water into the casting solution. • Permeability/porosity of macrovoid-free membranes compare to those with macrovoids. • Mechanical strength in macrovoid-free membranes is importantly enhanced. [ABSTRACT FROM AUTHOR]

Abstract: -poly(glutamic acid) (-PGA), a hydrophilic and biodegradable polymer, was chosen to modify chitosan matrices to produce a -PGA/chitosan composite biomaterial. Three types of both dense and porous composite matrices containing different amounts of -PGA were fabricated. Chitosan and -PGA matrices were also prepared as controls. Fluorescence staining indicated that chitosan and -PGA were evenly distributed in the composite matrices. SEM micrographs showed that an interconnected porous structure with a pore size of 30–100μm was present in all porous matrices except the -PGA ones. By increasing the percentage of -PGA from 0% to 20%, the swelling ratio of the matrices was enhanced from 1.6 to 3.2. Similarly, the contact angle of the matrices decreased from 113° to 94°. These data suggested that the surface hydrophilicity, water absorption rate, and swelling ratio were improved by adding -PGA to the matrices. Additionally, the mechanical strength of the porous -PGA/chitosan matrices was about 25–50%, higher than that of the unmodified chitosan matrices. The composite matrices were also examined and found to be an appropriate environment for cell attachment and proliferation. The cell density on the 20% -PGA-modified matrices was almost triple that on the unmodified chitosan matrices on day 5. In summary, the -PGA/chitosan composite matrices, due to their better hydrophilic, cytocompatible, and mechanical properties, are very promising biomaterials for tissue engineering applications. [Copyright &y& Elsevier]

Polyglycolide (PGA) and chitosan mixture solution was prepared using solvents of low toxicity to create novel, porous, biocompatible, degradable, and modifiable hybrid matrices for biomedical applications. The porosity of these PGA-chitosan hybrid matrices (P/C matrices) was created by a thermally induced phase separation method. Two types of the P/C hybrid matrices containing 70 wt% PGA (P/C-1 matrix) and 30 wt% PGA (P/C-2 matrix) were fabricated. Chitosan matrix was also prepared for comparison. A 35-day in vitro degradation revealed that the weight losses for the P/C-1 and P/C-2 matrices were similar (∼61%), but the releases of glycolic acid from the P/C-1 and P/C-2 matrices were 95% and 60%, respectively. The P/C-1 matrix had higher porosity and higher mechanical strength than the P/C-2 and chitosan matrices. Fibroblast cells cultivated in these matrices proliferated well and the cell density was the highest in the P/C-1 matrix, followed by the chitosan and P/C-2 matrices, suggesting good biocompatibility for the P/C-1 matrix. We thereby concluded that the P/C-1 matrix, due to its high strength, porosity, biocompatibility and degradability, is a promising biomaterial. The presence of chitosan in the P/C matrices provides many amino groups for further modifications such as biomolecule conjugation and thus enhances the application potential of the P/C hybrid matrices in tissue engineering. [Copyright &y& Elsevier]

In this study, we employed carbon nanotubes (CNTs) to improve the performance of flow-electrode capacitive deionization (FCDI) for wastewater desalination in isolated closed-cycle (ICC) mode. The effects of CNTs loading and initial salt concentration on FCDI desalination were evaluated with energetic performance analysis. FCDI was carried out for the desalination with real wastewater for technology demonstration. The addition of CNTs significantly improved the average salt removal rate (ASRR), associated with a decrease in the flow-electrode flowability. FCDI with 0.25 wt% CNTs had an ASRR of 1.59 μmol/cm2–min, which was 1.7-fold higher than that without CNTs. This was attributed to the bridging effect of CNTs for more rapid charge transfer. Increasing the initial salt concentration from 0.05 to 0.30 M led to a higher ASRR, resulting from a reduction in the electrical resistance in the cell. After further increasing the salt concentration to 0.50 M, the charge efficiency was relatively decreased due to co-ion leakage. Notably, FCDI for the desalination of real saline wastewater achieved a high decrease in conductivity (94%), a high charge efficiency (>99%), and low energy consumption (0.034 kWh/mol). Our results demonstrated that adding CNTs is a feasible approach to achieve high-performance FCDI for sustainable wastewater desalination. [Display omitted] • CNTs were employed to enhance the desalination performance of the FCDI process. • CNTs improved the salt removal rate and energy performance of ICC-mode FCDI. • FCDI can desalinate saline water with a wider concentration range. • FCDI exhibits great potential for real wastewater desalination. [ABSTRACT FROM AUTHOR]

Plant-specific WRKY transcription factors play important roles in regulating the expression of defense-responsive genes against pathogen attack. A multiple stress-responsive WRKY gene, ZmWRKY65, was identified in maize by screening salicylic acid (SA)-induced de novo transcriptomic sequences. The ZmWRKY65 protein was localized in the nucleus of mesophyll protoplasts. The analysis of the ZmWRKY65 promoter sequence indicated that it contains several stress-related transcriptional regulatory elements. Many environmental factors affecting the transcription of ZmWRKY65 gene, such as drought, salinity, high temperature and low temperature stress. Moreover, the transcription of ZmWRKY65 gene was also affected by the induction of defense related plant hormones such as SA and exogenous ABA. The results of seed germination and stomatal aperture assays indicated that transgenic Arabidopsis plants exhibit enhanced sensitivity to ABA and high concentrations of SA. Overexpression of ZmWRKY65 improved tolerance to both pathogen attack and abiotic stress in transgenic Arabidopsis plants and activated several stress-related genes such as RD29A, ERD10, and STZ as well as pathogenesis-related (PR) genes such as PR1, PR2 and PR5; these genes are involved in resistance to abiotic and biotic stresses in Arabidopsis. Together, this evidence implies that the ZmWRKY65 gene is involved in multiple stress signal transduction pathways. [ABSTRACT FROM AUTHOR]

The authors experimentally demonstrate that the spectral flatness of chaotic light from an external‐cavity feedback semiconductor laser is significantly improved using a fibre Bragg grating. The effects of detuning between the Bragg frequency and chaotic frequency on the bandwidth and spectral flatness are both investigated. The flatness of the power spectrum is enhanced to ±1.4 dB whilst maintaining the spectral bandwidth at around 8 GHz. The experimental results are in accordance with theoretical predictions which also have shown that the spectral flatness decreases initially then increases with increasing the 3 dB bandwidth of grating. A flattened spectrum with a low‐pass energy distribution increases the utilisation efficiency of chaotic light in chaotic radar and reflectometry. [ABSTRACT FROM AUTHOR]

• LPS promotes adhesion of CaOx crystals to RETCs and intrarenal crystals deposition. • LPS induces non-canonical inflammasome-mediated RTECs pyroptosis. • Melatonin inhibits LPS-induced non-canonical inflammasome-mediated RTECs pyroptosis. • Melatonin alleviates LPS-mediated crystals adhesion and intrarenal CaOx deposition. Urinary tract infection has long been considered a complication rather than etiology of calcium oxalate (CaOx) nephrolithiasis. This study aimed to explore the role of lipopolysaccharide (LPS), an important component of Gram-negative bacteria, on CaOx nephrolithiasis formation and antagonistic effect of melatonin. Male C57BL/6 mice were intraperitoneally injected with glyoxylate acid (80 mg/kg) daily for 7 days to construct CaOx nephrolithiasis model. A single dose of LPS (2.0 mg/kg) was given 2 h before the second glyoxylate acid treatment in the presence or absence of melatonin (25 mg/kg). Our results found that LPS promoted adhesion of CaOx crystals to renal tubular epithelial cells (RTECs) and intrarenal CaOx crystals deposition. Protein levels of cleaved Caspase-11, N-terminal of cleaved GSDMD (GSDMD-N), NOD-like receptor thermal protein domain associated protein 3 (NLRP3) and cleaved Caspase-1, several markers of non-classical inflammasome activation were upregulated in LPS-treated mouse kidneys and HK-2 cells. Moreover, the number of GSDMD pores was increased in LPS-treated HK-2 cell membrane. Melatonin inhibited Caspase-11 cleavage and antagonized the subsequent LPS-mediated upregulation of GSDMD-N, NLRP3 and cleaved Caspase-1 in kidney tissues and HK-2 cells. In addition, melatonin reduced membrane localization of GSDMD-N and the number of GSDMD pores in LPS-treated HK-2 cells. Accordingly, melatonin inhibited LPS-induced IL-1β and IL-18 in mouse serum and HK-2 culture supernatant. Importantly, melatonin alleviated LPS-induced crystal-cell interactions and intrarenal CaOx crystals deposition. We provide experimental evidence that LPS promoted CaOx nephrolithiasis formation by inducing non-canonical inflammasome-mediated RTECs pyroptosis. Melatonin alleviated CaOx nephrolithiasis formation through inhibiting LPS-induced non-canonical inflammasome-mediated RTECs pyroptosis. [ABSTRACT FROM AUTHOR]

Seeded growth is the most popular approach to the preparation of zeolite thin films and membranes. Herein, we report a simplified method of fabricating zeolite Faujasite (FAU) thin films through the direct wet deposition of zeolite FAU thin films using stabilized colloidal suspensions. Zeolite FAU suspensions are stabilized by adjusting the pH values and the suspensions are spin-coated on a silicon wafer substrate to form dense zeolite FAU thin films. Dynamic light scattering (DLS) was used to investigate the colloidal properties of the zeolite FAU suspensions. The time-dependent hydrodynamic radius R h was derived from DLS measurements for use as a quantitative measure of colloidal stability. It was found that high pH values destabilize the colloidal suspensions. Thin film samples cast using the relatively stable zeolite FAU suspensions yielded thin films with uniform morphology. In thin films formed from suspensions with a high pH value, the zeolite FAU crystals transformed into a dense phase. We also measured the relative permittivity ( ε r ) of the thin film samples cast from various suspensions. At a low frequency (<100 kHz), thin films that compose zeolite FAU crystals presented higher ε r values than did those possessing nonporous particles. The high ε r values of the zeolite FAU thin films can probably be attributed to the physical adsorption of water. At a high frequency (1000 kHz), water had far less effect on ε r values and thin films with a zeolite FAU structure presented ε r values characteristic of low-dielectric constant (low- k ) thin films. [ABSTRACT FROM AUTHOR]

Abstract: Producing zeolite films with controlled preferred orientation on an industrial scale is a long‐standing challenge. Herein we report on a scalable approach to the direct wet deposition of zeolite thin films and membranes while maintaining a high degree of control over the preferred crystal orientation. As a proof of concept, thin films comprising aluminophosphate zeolite AEI were cast on silicon wafer or porous alumina substrates. Electrical properties and separation performance of the zeolite thin films/membranes were engineered through controlling degree of preferred crystal orientation. [ABSTRACT FROM AUTHOR]

In the present work, polyvinylidenedifluoride-co-chlorotrifluoroethylene (PVDF- co -CTFE) hollow fiber membranes were prepared via non-induced phase separation (NIPS) using 1-methyl-2-pyrrolidone (NMP) or triethyl phosphate (TEP) as the solvent. The thermodynamic characterization of both systems PVDF- co -CTFE/NMP/water and PVDF- co -CTFE/TEP/water) and the rheological properties of dope solutions were first investigated. Subsequently, the effect of dope concentration and spinning conditions such as air gap on the membrane permeability and mechanical strength was discussed in detail. The rejection of polystyrene with a size of 50 nm was 85, 100 and 100% for PVDF- co -CTFE hollow fiber membranes prepared with PVDF- co -CTFE concentrations of 14,17 and 20 wt%, while the permeability was 119, 39 and 2.5 L/m 2  h bar, respectively. The morphologies of hollow fiber membranes were observed using scanning electron microscopy to evaluate the effect of solvent and spinning conditions on the membrane structure. The resultant PVDF and PVDF- co -CTFE hollow fiber membranes were immersed in a strong alkaline solution (NaOH (1 M)+NaClO (4000 ppm)) to evaluate the chemical resistance of PVDF- co -CTFE hollow fiber membranes in comparison with that of PVDF membranes. The mechanical properties of PVDF and PVDF- co -CTFE hollow fiber membranes immersed in the alkaline solution for 180 days were declined 90% and 10% as compared to the original ones, respectively. Moreover, the hollow fiber membranes were characterized using laser Raman spectra, Fourier-transform infrared spectra, differential scanning calorimetry, and X-ray photoelectron spectroscopy, before and after the immersion, to hypothesize the degradation mechanism of PVDF- co -CTFE and PVDF hollow fiber membranes in the alkaline solution. [ABSTRACT FROM AUTHOR]

Previous studies demonstrated that inflammatory microenvironment promoted prostate cancer progression. This study investigated whether total glucosides of paeony (TGP), the active constituents extracted from the root of Paeonia Lactiflora Pall, suppressed lipopolysaccharide (LPS)-stimulated proliferation, migration and invasion in androgen insensitive prostate cancer cells. PC-3 cells were incubated with LPS (2.0 μg/mL) in the absence or presence of TGP (312.5 μg /mL). As expected, cells at S phase and nuclear CyclinD1, the markers of cell proliferation, were increased in LPS-stimulated PC-3 cells. Migration activity, as determined by wound-healing assay and transwell migration assay, and invasion activity, as determined by transwell invasion assay, were elevated in LPS-stimulated PC-3 cells. Interestingly, TGP suppressed LPS-stimulated PC-3 cells proliferation. Moreover, TGP inhibited LPS-stimulated migration and invasion of PC-3 cells. Additional experiment showed that TGP inhibited activation of nuclear factor kappa B (NF-κB) and mitogen-activated protein kinase (MAPK)/p38 in LPS-stimulated PC-3 cells. Correspondingly, TGP attenuated upregulation of interleukin (IL)-6 and IL-8 in LPS-stimulated PC-3 cells. In addition, TGP inhibited nuclear translocation of signal transducer and activator of transcription 3 (STAT3) in LPS-stimulated PC-3 cells. These results suggest that TGP inhibits inflammation-associated STAT3 activation and proliferation, migration and invasion in androgen insensitive prostate cancer cells. [ABSTRACT FROM AUTHOR]

Global climate change has resulted in increasingly harsh environments that have become the restriction factors for plants growth and development. Calcium-dependent protein kinases (CDPKs) in plants play critical roles in resisting various abiotic stresses, such as heat and cold stresses. Using the expression pattern analysis of foxtail millet CDPK family members under heat- and cold-treatments, respectively, and the SiCDPK7 was found to respond to extreme temperature stress and was selected for further study. The results suggested that overexpression of SiCDPK7 in Arabidopsis conferred tolerance to heat stress by increasing seedling survival rates and hypocotyl elongation compared with wild type (WT) plants, and also can enhance heat stress tolerance in foxtail millet. Analysis of physiological and biochemical indexes showed that SiCDPK7 transgenic plant lines had the markedly higher catalase (CAT) activity and the significantly lower malonaldehyde (MDA) content than WT plants. In addition, qRT-PCR analysis showed that the transcription levels of heat and cold stress-responsive genes were significantly increased in SiCDPK7 transgenic Arabidopsis and foxtail millet under stress conditions. This supporting evidence suggests that SiCDPK7 facilitated the extreme temperature tolerance capabilities in plants • Our study suggests that SiCDPK7 facilitated the extreme temperature tolerance capabilities in plants. • We verified the function of SiCDPK7 by transgenic techniques in Arabidopsis thaliana and foxtail millet. • Further study showed that some heat- and cold-regulated genes were up-regulated in transgenic plants, which revealed that plant CDPKs play important roles in plants for responding to extreme temperature stress. • Our results possible to provide a great candidate gene and important theoretical evidences for breeding temperature-resistant varieties. [ABSTRACT FROM AUTHOR]

In this study, we designed a method for the preparation of chitosan nanoparticles incorporated into a quaternized poly(vinyl alcohol) (QPVA) matrix for direct methanol alkaline fuel cells (DMAFCs). The structural and morphological properties of the prepared nanocomposites were studied using X-ray diffraction (XRD), field-emission scanning electron microscopy (FE-SEM), transmission electron microscope (TEM) and dynamic laser-light scattering (DLS). The crystallinity of the nanocomposite solid electrolytes containing 0 and 10% chitosan nanoparticles were investigated using differential scanning calorimetry (DSC). The electrochemical measurement of resulting nanocomposite membranes were analyzed according to the following parameters: methanol permeability, liquid uptakes, ionic conductivity and cell performances. The composite membranes with 10% chitosan nanoparticles in a QPVA matrix (CQPVA) show suppressed methanol permeability and higher ionic conductivity than pristine QPVA. In addition, the glutaraldehyde cross-linked nanocomposite film exhibited improvement on the methanol barrier property at 80 °C. The peak power density of the DMAFCs reached 67 mW cm −2 when fed into 1 M of methanol in 6 M of KOH. [ABSTRACT FROM AUTHOR]

This study fabricates a transparent cyclic olefin copolymer (COC)/thermally reduced graphene oxide (TRGO) composite film with low content of TRGO, which exhibits high water vapor barrier properties. With only 0.06 wt% (0.028 vol%) TRGO, the COC/TRGO composite film reduces the water vapor permeability by ∼21%. The amount of TRGO in this work is 10–100 times lower than that in other polymer/clay or polymer/graphene composites that reduce the water vapor permeability at the same percentage. Low TRGO content has benefits of fabricating a film with low cost, high transparency, and truly excellent flexibility. The water vapor permeabilities of COC/TRGO composites are much lower than those predicted by Cussler or Nielsen model because of the significant rigidification of COC chains near TRGOs. The COC/TRGO composite film was annealed at different temperatures and then surface modified with amphiphilic polymer to further improve its barrier performance. By treating the film with 0.06 wt% TRGO, the water vapor permeability is greatly reduced by ∼65%. [ABSTRACT FROM AUTHOR]

Current techniques for fabricating chitosan–gelatin-based nanofibers require the use of corrosive and expensive solvents. Our novel method, however, using gum arabic and a mild (20 wt%) aqueous acetic acid solution as solvent can produce a solution with much higher chitosan–gelatin content (16 wt%). Without gum arabic, which greatly decreases the viscosity of the solution, such an outcome was unachievable. The solution was utilized to prepare electrospun chitosan–gelatin–polyvinyl alcohol–gum arabic nanofibers with a weight ratio of 8:8:2:0.5 (C8G8P2A0.5 nanofibers), in which polyvinyl alcohol could stabilize the electrospinning process. The stability and tensile strength (2.53 MPa) of C8G8P2A0.5 nanofibers (mats) were enhanced by glutaraldehyde crosslinking. Furthermore, mesenchymal stem cells attached and proliferated well on the mat. The strength-enhanced and cytocompatible C8G8P2A0.5 mats are thereby suitable for tissue engineering applications. More importantly, we have created a less expensive and safer method (one not using hazardous solvents) to fabricate chitosan–gelatin-based nanofibers. [ABSTRACT FROM AUTHOR]

Highlights: [•] Novel chitosan/pectin/gum Arabic (C/P/A) polyelectrolyte complex (PEC) solutions and membranes were prepared. [•] The appearance of the C/P/A PEC solutions, either turbid or clear, was process-dependent. [•] The C/P/A solutions contained both globe-like and network-like microstructures. [•] The tensile strength and hydrophilicity of the C/P/A (weight ratio: 84/8/8) membranes were enhanced. [•] Using the C/P/A membranes as a drug carrier exhibited steady and complete drug (insulin) release. [ABSTRACT FROM AUTHOR]

Epoxy porous monoliths were prepared from a commercial epoxy resin, D.E.R. 331, that cured with a tertiary amine, 2,4,6-tris-(dimethylaminomethyl) phenol, in the presence of a solvent, diisobutyl ketone (DIBK). During the curing process, polymers were formed and a decrease in its solubility in DIBK; the solution thus phase-separated, usually referred to as chemically induced phase separation. The phase separation formed interconnected polymer-poor phase that then became interconnected pores after the removal of DIBK. By varying the content of DIBK from 32 to 40 vol.%, epoxy monoliths with interconnected pores were prepared, with surface pore size ranging from 0.20 to 2.33 μm, overall porosity from 0.41 to 0.60, and ethanol permeability from 10 to 4,717 L/(m h bar). The glass transition temperatures of the epoxy monoliths, measured with differential scanning calorimetry, were all higher than 100 °C, and temperatures of 5 % weight loss, analyzed by thermal gravimetry, were higher than 350 °C, evidencing the monoliths' high thermal stability. Also, the monolith morphology was found to be strongly related to the reaction mechanism of polymerization. The results indicate that the mechanism of chain initiation and propagation associated with the tertiary amine can effectively form monoliths with interconnected pores, which cannot be easily prepared with a stepwise polymerization mechanism associated with using primary amine as the curing agent. [ABSTRACT FROM AUTHOR]

Abstract: Novel composite porous membranes made of basic and acidic polysaccharides (i.e. chitosan and pectin) were developed. Three types of chitosan/pectin composite membranes were fabricated: PEC-type (by polyelectrolyte complex (PEC) formation between chitosan and pectin); PEC/Ca-type (by PEC and calcium ion-mediated ionic crosslinking toward pectin); and PEC/covalent-type membranes (by PEC and EDC/NHS-mediated covalent bond). Tensile strengths (about fourfold that of pure chitosan membranes), hydrophilicity and water uptake capability of the composite membranes were significantly greater than membranes composed of chitosan or pectin only. Such composite membranes had faster disintegration rates which could be controlled by the content of pectin. Addition of calcium ions or EDC/NHS further increased the tensile strengths of the composite membranes (by about 1.5-fold) and also changed the profile of disintegration. Such chitosan/pectin composite membranes, due to their enhanced strength, hydrophilicity and controllable disintegration behavior, have potential as edible sponges or disintegrant carrying food or drug. [Copyright &y& Elsevier]

Abstract: A freeze-gelation method was utilized to prepare porous scaffolds made of chitosan, alginate, and carboxymethyl cellulose because of their usefulness in tissue engineering applications. These polysaccharide solutions were cooled down to freezing using either a fast-cooling (FC) mode (>20°C/min) or a slow-cooling (SC) mode (0.83°C/min). Then the frozen polysaccharide solutions were immersed in their respective non-solvents to form porous scaffolds. Based on the SEM and optical microscope images of the scaffolds, the FC mode induced non-simultaneous nucleation and generated directional pore structures. In contrast, simultaneous nucleation and uniform and isotropic pore structures (mean pore size: 60–100μm) were obtained by using the SC mode. Moreover, the tensile strength of the scaffolds prepared by the SC mode (about 60N/g) was three times higher than that of scaffolds prepared by the FC mode (about 20N/g). This study reveals that when using the freeze-gelation method, the cooling rate (mode) is a crucial factor which controls the pore structure and strength of porous scaffolds. Therefore, our results suggest that polysaccharide scaffolds with pore structures suitable for tissue engineering applications can be obtained via an appropriate cooling mode. [Copyright &y& Elsevier]

Abstract: Chitosan (CH) is a biomaterial with antiseptic, bioactive, and biocompatible properties. To further enhance the performance of chitosan membranes, chondroitin sulfate (CS) was utilized to modify the porous chitosan membranes fabricated by the freeze-gelation method. The cross-linking of CS to CH was mediated by ionic interaction and covalent cross-linking using EDC/NHS coupling reagents. The pore structures, mechanical properties, and surface hydrophilicity of the porous chondroitin sulfate-modified chitosan (CH/CS) membranes could be altered by varying the weight ratio of CS to CH. The membranes had interconnected stratiform pore structure with surface pore size ranging from 10 to 40 µm. Among various CH/CS membranes the one with the weight ratio of 90/10 (CH to CS) possessed the highest mechanical strength (18.61 N/g), about 40% increase as compared with the unmodified CH membrane. The addition of CS improved the hydrophilicity of the membranes. Preliminary cell culture experiments revealed that the proliferation of the gingival fibroblasts on the CH/CS surface was slightly better than that on the CH surface. In summary, the CH/CS membranes (especially the 90/10 membrane), due to their higher mechanical strength, hydrophilicity, and better cell compatibility, are promising biomaterials for tissue engineering applications. [Copyright &y& Elsevier]

Abstract: The aim of this paper is to prepare a PVDF (polyvinylidene fluoride) microporous membrane by using alcohol as nonsolvent (coagulant). A porous membrane with high hydrophobic surface (water contact angle ~148°) was facilely created by wet immersion method without modification with special low surface energy compounds and the need of special instruments. In addition, the PVDF casting film was passed through alcohol bath for 2 s and then immersed into water precipitation bath, the porous PVDF membrane with hydrophobic surface (water contact angle ~135°) was also formed. The characterization of the porous PVDF membrane obtained from various coagulation conditions was carried out by a pore size analysis and a direct contact membrane distillation (DCMD). The permeation flux and rejection coefficient of the porous PVDF membrane fabricated via dual-bath coagulated was close to commercial one. [Copyright &y& Elsevier]

Abstract: To improve the pervaporation separation performance, an organic–inorganic hybrid membranes were prepared by adding zeolite 13X into the polyimide (BAPP–BODA), which was synthesized using one-step polycondensation polymerization of 2,2-bis(4-(4-aminophenoxy)phenyl)propane (BAPP) with bicyclo[2.2.2]oct-7-ene-2,3,5,6-tetracarboxylic dianhydride (BODA). The influence of the zeolite 13X content on the free volume and pervaporation performance of hybrid membranes were systematically analyzed by positron annihilation spectroscopy (PAS). The trend of ortho-positronium (o-Ps) lifetime and free volume holes changes consistently well with the permeation rate variation of aqueous isopropanol mixtures dehydration. The BAPP–BODA/13X hybrid membrane morphology was characterized by AFM and SEM. Compared with the BAPP–BODA membrane, the BAPP–BODA/13X hybrid membrane had good pervaporation performance for aqueous alcohol solution dehydration. The sorption selectivity dominates the behavior of pervaporation while adding zeolite 13X into the polyimide matrix. [Copyright &y& Elsevier]

Abstract: Nanocomposite proton exchange membranes were prepared from sulfonated poly(phthalazinone ether ketone) (sPPEK) and various amounts of sulfonated silica nanoparticles (silica-SO3H). The use of silica-SO3H compensates for the decrease in ion exchange capacity of membranes observed when non-sulfonated nano-fillers are utilized. The strong –SO3H/–SO3H interaction between sPPEK chains and silica-SO3H particles leads to ionic cross-linking in the membrane structure, which increases both the thermal stability and methanol resistance of the membranes. The membrane with 7.5 phr of silica-SO3H (phr=g of silica-SO3H/100g of sPPEK in membranes) exhibits low methanol crossover, high bound-water content, and a proton conductivity of 3.6 fold increase to that of the pristine sPPEK membrane. [Copyright &y& Elsevier]

Abstract: A newly developed freeze-gelation method for fabricating porous chitosan scaffolds for tissue engineering applications was analyzed. The influences of three process variables of freeze-gelation method on the tensile properties of the scaffolds were investigated. It was found that a higher freezing temperature (−20°C) and concentration of acetic acid (1–2M) significantly increased the tensile stress and strain of the scaffolds at maximum load, whereas a higher ethanol concentration (95%) in the rinse buffer slightly increased the tensile stress of the scaffolds at maximum load. Further, we successfully established a correlation to quantify the influence of these process variables of the freeze-gelation method on the tensile properties of the scaffolds. Hence, the correlation can be used for quantitative predictions of the tensile properties of the scaffolds. To enhance the tensile strength, the scaffolds were cross-linked using glutaraldehyde (GTA), N-(3-dimethyl-aminopropyl)-N′-ethylcarbodiimide hydrochloride (EDC), or tripolyphosphate (TPP). We found that both the tensile stress and strain at maximum load significantly and dose-dependently increased with the addition of the cross-linking agent, GTA. However, the addition of the cross-linking agents, EDC and TPP, only moderately increased the tensile stress and strain at maximum load, but no dose response was observed. In summary, our study analyzed the freeze-gelation and cross-linking processes for fabricating porous chitosan tissue engineering scaffolds with different tensile properties. [Copyright &y& Elsevier]

Summary: Objective: The aim of this study was to fabricate a novel composite porous scaffold by blending chitosan and gamma-poly(glutamic acid) (γ-PGA) for the sustained delivery of rhBMP-2. Methods: Chitosan and γ-PGA were blended to fabricate a novel porous scaffold by the freeze-gelation method. For comparison, scaffolds made of freeze-dried chitosan, freeze-dried PLLA, and freeze-gelled chitosan were also prepared. The scaffolds were loaded with rhBMP-2, and then the controlled release of rhBMP-2 from the scaffolds was assessed by ELISA. Results: The freeze-gelled chitosan/γ-PGA scaffold (M 0=318.29ng, k=0.32d−1) gave the most satisfactory release curve, followed by the freeze-gelled chitosan (M 0=392.76ng, k=0.59d−1), freeze-dried chitosan (M 0=229.21ng, k=2.28d−1), and freeze-dried PLLA (M 0=8.4ng, k=482.54d−1) scaffolds. In the stability test, p-dioxane (the solvent for PLLA) seriously deteriorated rhBMP-2, whereas acetic acid (the solvent for chitosan) did not. Significance: A novel chitosan/γ-PGA composite scaffold for the controlled release of rhBMP-2 was established, with an enhanced release amount and sustained release behavior. This scaffold has many potential applications in bone regenerative therapies. [Copyright &y& Elsevier]

Freeze-fixation and freeze-gelation methods are presented in this paper which can be used to prepare highly porous scaffolds without using the time and energy consuming freeze-drying process. The porous structure was generated during the freeze of a polymer solution, following which either the solvent was extracted by a non-solvent or the polymer was gelled under the freezing condition; thus, the porous structure would not be destructed during the subsequent drying stage. Compared with the freeze-drying method, the presented methods are time and energy-saving, with less residual solvent, and easier to be scaled up. Besides, the problem of formation of surface skin can be resolved and the limitation of using solvent with low boiling point can be lifted by the presented methods. With the freeze-extraction and freeze-gelation methods, porous PLLA, PLGA, chitosan and alginate scaffolds were successfully fabricated. In addition to the presentation of the morphologies of the fabricated scaffolds, preliminary data of cell culture on them are as well included in the present work. [Copyright &y& Elsevier]

A membrane stack configuration with activated carbon electrodes was developed to integrate the capacitive and electrodialysis contributions for continuous, low energy desalination. [Display omitted] • A cell was developed by stacking IEMs between capacitive electrodes. • During the charging step, the ions were removed by electrosorption/electrodialysis. • During the discharging step, the ions were removed by dialytic separation. • The continuous desalination was achieved by a cyclic charging/discharging process. • High charge efficiency and low energy consumption were achieved. Significant efforts have been made to develop advanced energy-efficient desalination technologies for delivering freshwater. Capacitive deionization and electrodialysis represent electric field-driven separation technologies for water desalination. In this study, a new design for a membrane stack configuration based on an integrated capacitive-electrodialysis process (CapED) was proposed for continuous and energy-efficient desalination. From the activated carbon anode to the cathode, an anion exchange membrane (AEM), a cation exchange membrane (CEM), an AEM, and a CEM were placed in order (anode/AEM/CEM/AEM/CEM/cathode). Herein, three chambers between two capacitive electrodes were separated by a CEM and an AEM, which enabled simultaneous and continuous generation of desalinated and concentrated solutions. During charging, capacitive electrosorption and electrodialytic separation accounted for desalination. During discharging, the energy stored by capacitive electrosorption was utilized for desalination through dialytic separation. Therefore, continuous desalination could be achieved by a cyclic charging/discharging process. In addition, the salt removal amount was enhanced by increasing the voltage with respect to the different capacitive and electrodialytic contributions. The energy consumption ranged between 0.53 and 1.45 kWh/kg with high charge efficiency, indicating a low energy requirement. Our research showed that CapED was effective when integrating capacitive and electrodialytic contributions for electrochemical water desalination. [ABSTRACT FROM AUTHOR]

This work scrutinizes a versatile process during which amphiphilic copolymers (made of styrene and sulfobetaine methacrylate, ethylene glycol methacrylate or vinylpyrrolidone) are simultaneously copolymerized and coated on microporous poly (vinylidene fluoride) (PVDF) membranes. Changing the nature of the hydrophilic monomer and the reaction conditions, it is possible to regulate the wetting properties of the membranes by water and oil. The main surface physical properties of the membranes were not modified for a reaction/deposition bath containing up to 50% styrene monomer, but larger styrene amounts led to aggregate formation. A 50% molar ratio in hydrophobic/hydrophilic unit led to a suitable balance between stability and hydration, resulting in optimized water permeation and oil repellence. Gravity-driven separation of oily wastewaters was doable with all selected membranes (St50S50, St50P50 and St50V50) and oils tested (toluene, hexane, diesel). Nevertheless, it is highlighted that PEGylated surfaces offer the best overall compromise between separation kinetic and separation efficiency. Results also suggested that zwitterionization with larger amounts of zwitterionic monomers is not practical, possibly because it leads to a hydration layer too tight, which slows down the gravity-driven separation. This study demonstrates the effectiveness/versatility of this surface modification method to quickly hydrophilize PVDF membranes applied to energy-efficient separation of emulsions. Image 1 • A simultaneous polymerization/coating method is introduced. • The process is workable with a large variety of monomer units. • Modified membranes are applied to O/W gravity-driven separation. • PEGylated membranes offer the best flux/separation efficiency compromise. [ABSTRACT FROM AUTHOR]

Genus Pseudomonas bacteria mainly consume glucose through the Entner-Doudoroff (ED) route due to a lack of a functional Embden-Meyerhof-Parnas (EMP) pathway. In the present study, a 6-phosphogluconate dehydratase ( edd ) operon in the ED route was well investigated to find its structural characteristics and roles in the regulation of glucose consumption and 2-ketogluconic acid (2KGA) metabolism in the industrial 2KGA-producer P. plecoglossicida JUIM01. The edd operon contained four structural genes of edd , glk , gltR , and gtrS , encoding 6-PG dehydratase Edd, glucokinase Glk, response regulatory factor GltR, and histidine kinase GtrS, respectively. A promoter region was observed in the 5'-upstream of the edd gene, with a transcriptional start site located 129 bp upstream of the edd gene and in a pseudo-palindromic sequence of 5'-TTGTN 7 ACAA-3' specifically binding to the transcription factor HexR. The knockout of the edd gene showed a remarkably negative effect on cell growth and re-growth using 2KGA as a substrate, beneficial to 2KGA production, with an increase of 8%. The deletion of glk had no significant effect on the cell growth or glucose metabolism, while showing an adverse impact on the 2KGA production, with a decrease of 5%. The outputs of the present study would provide a theoretical basis for 2KGA-producer improvement with metabolic engineering strategies and the development and optimization of P. plecoglossicida as the chassis cells.

In the present study, gelatin-based films incorporating squid pen chitosan obtained by high hydrostatic pressure (HHP chitosan) at varying proportions were prepared and their properties were compared with films containing untreated chitosan. The resulting films were characterized by analyzing the physical, morphological, mechanical and barrier properties. The addition of different ratios of HHP chitosan to the gelatin-based film yielded significant improvements in mechanical and moisture barrier properties. The reason for this might be that HHP chitosan contributed to a regular and dense microstructure of the composite films due to forming a three-dimensional network structure in gelatin-based films with enhanced intermolecular interactions. The FTIR spectra showed no new chemical bond formed by incorporating HHP chitosan into gelatin-based film. The SEM micrographs showed that the gelatin-based film fabricated with three types of chitosan had a homogeneous surface morphology, indicating good compatibility of the materials. Compared to the gelatin-based films containing untreated chitosan, films containing HHP chitosan significantly delayed oxidative deterioration in oil during storage. Therefore, the chitosan obtained by HHP treatment could have a potential application in edible gelatin-based films as packaging materials.

PVDF membranes were prepared with nonsolvent-induced phase separation, using solvents with various dipole moments, including HMPA, NMP, DMAc and TEP. Both the fraction of the polar crystalline phase and the water permeability of the prepared membrane increased monotonously with an increasing solvent dipole moment. FTIR/ATR analyses were conducted at the surfaces of the cast films during membrane formation to provide information on if the solvents were present as the PVDF crystallized. The results reveal that, with HMPA, NMP or DMAc being used to dissolve PVDF, a solvent with a higher dipole moment resulted in a lower solvent removal rate from the cast film, because the viscosity of the casting solution was higher. The lower solvent removal rate allowed a higher solvent concentration on the surface of the cast film, leading to a more porous surface and longer solvent-governed crystallization. Because of its low polarity, TEP induced non-polar crystals and had a low affinity for water, accounting for the low water permeability and the low fraction of polar crystals with TEP as the solvent. The results provide insight into how the membrane structure on a molecular scale (related to the crystalline phase) and nanoscale (related to water permeability) was related to and influenced by solvent polarity and its removal rate during membrane formation.

Objective: To investigate the related factors of invasive transformation and prognosis for follicular lymphoma., Methods: A total of 168 patients with follicular lymphoma at First Affiliated Hospital of Zhengzhou University from August 2015 to January 2021 were collected, and the significance of each index in histological transformation (HT) and prognosis were analyzed., Results: Pathology grade3, Ki-67 index ≥40%, β 2 MG＞3 mg/L, LDH＞245 U/L, POD24 and non-invasion of bone marrow were associated with HT. Univariate analysis showed that the high risk of FLIPI-2, pathological grade 3, Ki-67≥40%, anemia, β 2 MG＞3 mg/L, LDH＞245 U/L and HT had significant adverse effects on PFS; β 2 MG＞3 mg/L, LDH＞245 U/L, POD24 and HT had significant adverse effects on OS. Cox multivariate analysis showed that the β 2 MG >3 mg/L and HT were independent risk factors of PFS, HT was independent risk factor of OS., Conclusion: The pathological grade, Ki-67, β 2 MG, LDH, POD24 and bone marrow invasion of FL can predict the risk of HT. Meanwhile, β 2 MG >3 mg/L and HT are significantly related to poor prognosis of FL.

Dehydration-responsive element-binding (DREB) transcription factors regulate diverse processes during plant development. Here, a 2-year field study was conducted to assess the potential effects of DREB-genetically modified maize (GM1) on arthropod species and ecological communities. Arthropod abundance, diversity, and community composition in GM1 and its non-transformed counterpart maize variety, Chang 7-2, were compared using whole plant inspection, pitfall trap, and suction sampler methods. Based on Shannon-Wiener diversity, Simpson's diversity, Pielou's indexes, number of species, and total number of individuals, GM1 had a negligible effect on arthropod abundance and diversity. Redundancy analysis indicated that the composition of arthropod community was not associated with maize type in the three investigation methods, while it exhibited significant correlation with year and sampling time in whole plant inspection and suction sample methods, and distinctly correlated with sampling time in the pitfall trap method. Nonmetric multidimensional scaling analysis of variable factors in the three investigation methods showed that sampling time, rather than maize type or year, was closely related to the composition of arthropod community in the field. Our results provide direct evidence to support that DREB-GM maize had negligible effects on arthropods in the Jilin Province under natural conditions.

Cell injury is a necessary and critical event during CaOx kidney stone formation. Sirt1 exerts a number of pleiotropic effects, protecting against renal cell injury. This study aims to explore the relationship between Sirt1 and CaOx kidney stone formation and the underlying mechanism. Sirt1 expression in renal tissues or HK-2 cells was detected by Western blot, immunohistochemistry and immunofluorescence. Apoptosis in renal tissues was examined by TUNEL staining. Renal pathological changes and the crystals deposition were detected by hematoxylin-eosin and Von Kossa staining. Crystal-cell adhesion and cell injury in HK-2 cells were assessed by atomic absorption spectrometry and flow cytometry, respectively. Sirt1 expression in nephrolithiasis patients was downregulated and the level of apoptosis was increased. Further study found that Sirt1 expression was decreased in both in vivo and in vitro models. Interestingly, the levels of cell injury were elevated in vivo and in vitro models. Suppressing Sirt1 expression promoted COM-induced crystal-cell adhesion and exacerbated cell injury. In contrast, increasing the expression of Sirt1 by lentivirus transfection in vitro and resveratrol administration in vivo, alleviated crystal deposition and cell damage. Our findings suggest that Sirt1 could inhibit kidney stone formation, at least in part, through attenuating CaOx -induced cell injury., (Copyright © 2021 The Authors. Published by Elsevier B.V. All rights reserved.)

A two-stage semi-continuous strategy for producing 2-keto-gluconic acid (2KGA) by Pseudomonas plecoglossicida JUIM01 from rice starch hydrolyzate (RSH) has been developed. The initial glucose concentration (140 g/L) was selected for first-stage fermentation due to its highest 2KGA productivity of 7.58 g/(L⋅h), cell weight of 3.91 g/L, and residual glucose concentration of 25.00 g/L. Followed by removing 70.0% (v/v) of the first-stage broth and feeding 400.0 g/L of glucose to the second-stage fermentor, a total of 50680.0 g glucose was consumed, and 50005.20 g 2KGA was obtained with a yield of 0.9867 g/g by P. plecoglossicida JUIM01 after a 3-cycle two-stage semi-continuous fermentation. Our results indicated that the developed two-stage semi-continuous fermentation could be industrially applied due to its high 2KGA concentration, 2KGA yield and operation efficiency., (Copyright © 2020 Sun, Wang, Sun, Cui, Gong, Zhang, Shi and Xu.)

The membrane-bound gluconate dehydrogenase (mGADH) is a critical enzyme for 2-keto-D-gluconic acid (2KGA) production in Pseudomonas plecoglossicida JUIM01. The purified native flavin adenine dinucleotide-dependent mGADH (FAD-mGADH) was consisted of a gamma subunit, a flavoprotein subunit, and a cytochrome c subunit with molecular mass of ~ 27, 65, and 47 kDa, respectively. The specific activity of FAD-mGADH was determined as 90.71 U/mg at optimum pH and temperature of 6.0 and 35 °C. The K m and V max values of calcium D-gluconate were 0.631 mM and 0.734 mM/min. The metal ions Mg 2+ and Mn 2+ showed slight positive effects on FAD-mGADH activity. On the other hand, a 3868-bp-length gad gene cluster was amplified and expressed in Escherichia coli BL21(DE3). The recombinant protein showed the same molecular weight and enzyme activity as the native FAD-mGADH, which confirmed it as a FAD-mGADH encoding gene. The flavoprotein subunit and the cytochrome c subunit containing a putative FAD-binding motif and three possible heme-binding motifs concluded from alignment results of mGADHs. This study characterized the native and recombinant FAD-mGADH and would provide the basis for further genetic modification of Pseudomonas plecoglossicida JUIM01 with the intention of 2KGA productivity improvement.

The cost-effective treatment of emulsified oily wastewater discharged by many industries and human societies is a great challenge. Herein, based on an aliphatic polyketone (PK) polymer with a good membrane formation ability and an intrinsic intermediate hydrophilicity, a new class of reduced PK (rPK) membranes combining an all hydrophilic and electrically neutral surface chemistry comprising ketone and hydroxyl groups, and a fibril-like morphology featuring re-entrant structure, was facilely prepared by phase separation and following fast surface reduction. The synergetic cooperation of surface chemistry and surface geometry endowed the prepared membranes with excellent superhydrophilicity, underwater superoleophobicity, and underoil superhydrophilicity, in addition to antiprotein-adhesion property. Thus, fouling-resistant and self-cleaning filtrations of challenging oil-in-water emulsions containing adhesive oil, surfactant, high salinity, and proteins were effortlessly realized with high flux (up to ∼50 000 L m -2 h -1 bar -1 ), slow and reversible flux decline, and low oil permeate (<20 ppm). In contrast, a commercial superhydrophilic microporous membrane made of mixed cellulose ester suffered severe fouling gradually or immediately when carrying out the emulsion filtrations due to its less than ideal surface properties. It is believed that this class of membranes with desirable superwettability, high flux, and preparation simplicity can be a potential new benchmark for high performance and large-scale oil-water separation in complex environments.