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The assessment method of iodine nutrition for pregnant women lacks strong evidence-based medicine. The prevalence of iodine deficiency in pregnant women may be overestimated using urinary iodine concentration (UIC). The reference intervals of UIC-to-urinary creatinine concentration ratio (UIC/UCr) were established using a self-sequential longitudinal study of pregnant women with singleton gestation who were recruited using the criteria of the National Academy of Clinical Biochemistry in Dandong City, which is a long-term iodine-replete area. Nine thousand one hundred sixty-four pregnant women in the first trimester from Dalian City, Dandong City, and Shenyang City were included to verify our proposed reference intervals. UIC and concentrations of urinary creatinine, serum iodine, TSH, FT4, TPOAb, and TgAb were measured. The reference intervals of UIC/UCr were 38.63-489.46 μg/g for the first trimester, 58.48-644.03 μg/g for the second trimester, and 56.27-644.93 μg/g for the third trimester. The prevalence of iodine deficiency was 49.50% using UIC as the indicator ( 150 μg/L), while the prevalence was 3.28% using UIC/UCr ( 38.63 μg/g). The prevalence of iodine excess was 3.21% using UIC as the indicator ( 500 μg/L) while the prevalence was 1.45% using UIC/UCr ( 489.46 μg/g). The highest prevalence of overt hypothyroidism and positive thyroid antibodies was in the group with UIC/UCr 38.63 μg/g. In contrast to the place of residence and age, BMI was an influencing factor for UIC/UCr. The reference intervals of UIC/UCr were established. UIC/UCr may eliminate the effect of urine volume and reflect the actual prevalence of iodine deficiency in pregnant women.

Chemokine receptor 2 (CXCR2) is the receptor of glutamic acid–leucine–arginine sequence-contained chemokines CXCs (ELR+ CXCs). In recent years, CXCR2-target treatment strategy has come a long way in cancer therapy. CXCR2 antagonists could block CXCLs/CXCR2 axis, and are widely used in regulating immune cell migration, tumor metastasis, apoptosis and angiogenesis. Herein, two series of new CXCR2 small-molecule inhibitors, including 1,2,4-triazol-3-one derivatives 1–11 and pyridazinone derivatives 12–22 were designed and synthesized based on the proof-to-concept. The pyridazinone derivative 18 exhibited good CXCR2 antagonistic activity (69.4 ± 10.5 %Inh at 10 μM) and demonstrated its significant anticancer metastasis activity in MDA-MB-231 cells and remarkable anti-angiogenesis activity in HUVECs. Furthermore, noteworthy was that 18 exhibited an obvious synergistic effect with Sorafenib in anti-proliferation assay in MDA-MB-231 cells. Moreover, 18 showed a distinct reduction of the phosphorylation levels of both PI3K and AKT proteins in MDA-MB-231 cells, and also affected the expression levels of other PI3K/AKT signaling pathway-associated proteins. The molecular docking studies of 18 with CXCR2 also verified the rationality of our design strategy. All of these results revealed pyridazinone derivative 18 as a promising CXCR2 antagonist for future cancer therapy.

Summary High expression of the inhibitory receptor programmed cell death ligand 1 (PD-L1) on tumor cells and tumor stromal cells have been found to play a key role in tumor immune evasion in several human malignancies. However, the expression of PD-L1 on bone marrow mesenchymal stem cells (BMSCs) and whether the programmed cell death 1 (PD-1)/PD-L1 signal pathway is involved in the BMSCs versus T cell immune response in multiple myeloma (MM) remains poorly defined. In this study, we explored the expression of PD-L1 on BMSCs from newly diagnosed MM (NDMM) patients and the role of PD-1/PD-L1 pathway in BMSC-mediated regulation of CD8+ T cells. The data showed that the expression of PD-L1 on BMSCs in NDMM patients was significantly increased compared to that in normal controls (NC) (18·81 ± 1·61 versus 2·78± 0·70%; P

Dapagliflozin (DAPA), a kind of sodium-glucose cotransporter 2(SGLT2) inhibitor is used to treat diabetes mellitus by inhibiting urine glucose reuptake. Recent clinical outcomes indicate that SGLT2 inhibitors may exert pharmacological activities against non-alcoholic fatty liver diseases. Nonetheless, the underlying molecular mechanisms are still poorly elucidated. In this study, we investigated the potential anti-fatty liver effects of DAPA in vivo and in vitro and assayed their underlying mechanisms. Male NIH (National Institutes of Health) mice were fed with a high-fat diet (HFD) and then treated with DAPA by gavage for 4 weeks. In the following experiments, L02 cells were treated with oleic acid (OA) and different concentrations of DAPA to assess lipid metabolism. Our results revealed that DAPA administration could remarkably suppress excessive fat accumulation in the liver tissues of HFD-fed mice and OA-treated L02 cells. Importantly, DAPA could downregulate the expression levels of proteins related to lipid synthesis and upregulate the expression levels of genes associated with fatty acid oxidation in vitro and in vivo. We also found that DAPA intervention could activate adenosine monophosphate-activated protein kinase (AMPK) phosphorylation but inhibit mammalian target of rapamycin (mTOR) phosphorylation in vitro and in vivo. AMPK activation might be mediated by increasing liver kinase B1 activity and decreasing ATP level. Furthermore, these ameliorative effects were completely eliminated by an AMPK inhibitor, compound C. This study suggested that DAPA might remarkably ameliorate hepatic steatosis mediated through the AMPK/mTOR pathway and thus could be a potential drug candidate for the treatment of fatty liver diseases.

Summary Lipotoxicity plays an important role in the development of diabetic heart failure (HF). Canagliflozin (CAN), a marketed sodium-glucose co-transporter 2 inhibitor, has significantly beneficial effects on HF. In this study, we evaluated the protective effects and mechanism of CAN in the hearts of C57BL/6J mice induced by high-fat diet/streptozotocin (HFD/STZ) for 12 weeks in vivo and in HL-1 cells (a type of mouse cardiomyocyte line) induced by palmitic acid (PA) in vitro. The results showed that CAN significantly ameliorated heart functions and inflammatory responses in the hearts of the HFD/STZ-induced diabetic mice. CAN significantly attenuated the inflammatory injury induced by PA in the HL-1 cells. Furthermore, CAN seemed to bind to the mammalian target of rapamycin (mTOR) and then inhibit mTOR phosphorylation and hypoxia-inducible factor-1α (HIF-1α) expression. These results indicated that CAN might attenuate lipotoxicity in cardiomyocytes by inhibiting the mTOR/HIF-1α pathway and then show protective effects on diabetic hearts., Graphical abstract, Highlights • Canagliflozin ameliorated heart dysfunctions in HFD/STZ-induced diabetic mice • Canagliflozin inhibited lipotoxicity in palmitic acid-induced HL-1 cardiomyocytes • mTOR-HIF-1α pathway mediated lipotoxicity in cardiomyocytes • Canagliflozin bound to mTOR and inhibited mTOR-HIF-1α pathway, Human metabolism; Molecular biology

To date, drugs to attenuate cytokine storm in severe cases of Corona Virus Disease 2019 (COVID-19) are not available. In this study, we investigated the effects of intragastric and atomized administration of canagliflozin (CAN) on cytokine storm in lung tissues of lipopolysaccharides (LPS)-induced mice. Results showed that intragastric administration of CAN significantly and widely inhibited the production of inflammatory cytokines in lung tissues of LPS-induced sepsis mice. Simultaneously, intragastric administration of CAN significantly improved inflammatory pathological changes of lung tissues. Atomized administration of CAN also exhibited similar effects in LPS-induced sepsis mice. Furthermore, CAN significantly inhibited hypoxia inducible factor 1α (HIF-1α) and phosphofructokinase-2/fructose-2,6-bisphosphatase 3 (PFKFB3) protein levels in LPS-treated lung tissues. These results indicated that CAN might attenuate cytokine storm and reduce the inflammatory symptoms in critical cases in COVID-19. Its action mechanism might involve the regulation of HIF-1α and glycolysis in vivo. However, further studies about clinical application and mechanism analysis should be validated in the future.

Background Demographic, systemic and ocular factors may impact macular ganglion cell–inner plexiform layer (GCIPL) thickness measurements. This study aimed to investigate the influences of multiple potential determinants of macular GCIPL thickness in normal Chinese adults. Methods This was a retrospective study conducted on 225 normal eyes from 225 healthy Chinese adults. GCIPL thickness were obtained using Cirrus high-definition optical coherence tomography (OCT). The age, gender, laterality, spherical equivalent (SE) refractive error, intraocular pressure (IOP), axial length (AL), central cornea thickness (CCT), circumpapillary retinal nerve fibre layer (pRNFL) thickness and OCT signal strength were recorded and their respective effect on GCIPL thickness parameters were evaluated. Results The mean (± SD) average, minimum, superotemporal, superior, superonasal, inferonasal, inferior, and inferotemporal GCIPL thickness was 84.56 ± 5.36, 81.32 ± 5.58, 83.08 ± 5.37, 85.70 ± 5.95, 87.15 ± 6.26, 85.07 ± 6.11, 82.46 ± 5.76, and 83.88 ± 5.59 μm, respectively. Determinants of thinner GCIPL thickness were older age (P = 0.001–0.117; effects enhanced if age over 40 years), thinner pRNFL (all P P P = 0.069–0.842), and between right eyes and the left eyes (P = 0.160–0.875) except that of superonasal GCIPL thickness (P P = 0.135–0.968). Conclusions Individual determinants associated with thinner GCIPL thickness were older age (particularly over 40 years of age), thinner pRNFL, and weaker OCT signal strength. This is relevant in comprehensively understanding the normative data and differentiating normal aging from abnormalities.

Objective：As an important negative regulatory factor of immunological cells, Tim3 plays a regulating role in tumor immune microenvironment. The purpose of this study was to investigate the expression of Tim3 on MM cells and its effect on the proliferation and apoptosis of MM cells, as well as its potential mechanism. Methods: In this study, the expression of Tim3 was detected on myeloma cells (CD38+CD138+ cells) of bone marrow by flow cytometry (FCM) from 167 patients with MM and 51 healthy donors as controls and making correlation analysis with related clinical indexes. In vitro, MM cell lines (RPMI-8226 and U266) were treated with Tim3 knock-down alone, bortezomib alone and combination of Tim3 knock-down and bortezomib, then cell proliferation, cell apoptosis and downstream signaling pathway were detected by CCK-8, FCM, RT-PCR and western blot. Results: The expression of Tim3 on myeloma cells in MM patients was significantly higher than normal control group and positively correlated with β2 microglobulin, creatine and plasma cells of bone marrow, negatively correlated with hemoglobin and red blood cells. In vitro, we validated the high expression of Tim3 in RPMI-8226 and U266 cell lines. After Tim3 knock-down, the cell proliferation was inhibited and cell apoptosis was induced, the relative mRNA and protein expression of Tim3 and NF-κB signal pathway (PI3K, AKT, mTOR, NF-κB) were significantly decreased. Also, the cell proliferation was inhibited, cell apoptosis was increased, the relative mRNA and protein expression of NF-κB were decreased significantly in combination group than bortezomib or Tim3 knock-down group. Significantly. Conclusions: The high expression of Tim3 on MM cells is associated with progression of MM patients. Tim3 maybe regulate the proliferation of MM cells via NF-κB signal pathway. Down-regulation of Tim3 expression can inhibit proliferation and induce apoptosis of MM cells, also can enhance the inhibitory effect of bortezomib on NF-κB signaling pathway, then inhibit proliferation and induce apoptosis. Therefore, Tim3 may be a potential target for the diagnosis, prognosis and treatment of MM.

In this work, a novel sandwich-type aptasensor was designed for the ultrasensitive recognition of trace mercury ions in water. Numerous oriented platinum nanotube arrays (PtNAs) were in-situ crystallized on a flexible electrode as a sensing interface, while thionine labelled Fe 3 O 4 /rGO nanocomposites as signal amplifiers. Both PtNAs/CF and nanocomposites were synthesized by easy hydrothermal processes. With their large surface area, it was favorable for electrochemical performance and immobilization of capture DNAs (cDNA) and report DNAs (rDNA). Upon the existence of Hg 2+ , partial linker DNAs were tightly bound with cDNAs through thymine-Hg 2+ -thymine pairing (T-Hg 2+ -T). Then rDNAs attached Fe 3 O 4 /rGO nanoprobes were fixed on the electrode through the match of remaining linker DNAs and rDNAs. Under the optimal conditions, the Hg 2+ aptasensor showed a synergistic amplification performance with a wide linear range from 0.1nM to 100 nM, as well as a low detection limit of 30 pM. Moreover, the as-prepared aptasensor also exhibited reliable performance for assay in real lake water samples.

Developing solid materials with high CO2 adsorption capacity and catalytic activity has been a hotspot due to the greenhouse effect. In this work, bi-functionalized ionic liquid 1-vinyl-3-methoxyethyl imidazolium glycinate ([VMOEim][Gly]) was copolymerized with crosslinker divinylbenzene (DVB) to obtain bi-functionalized ionic liquid porous copolymers P(nDVB-[VMOEim][Gly]) and HP(nDVB-[VMOEim][Gly]). These copolymers possess loose stack of small particles or laminates, and they contain mesopores and a small number of micropores. For HP(0.6DVB-[VMOEim][Gly]), surface area reaches up to 508 m2·g−1 and the initial decomposition temperature is about 180 °C. Then these porous copolymers were applied for CO2 adsorption at 25 °C and cycloaddition reaction of CO2 with epichlorohydrin under ambient pressure and cocatalyst-free condition. The maximum CO2 capture capacity is 64.5 mg/g with HP(0.6DVB-[VMOEim][Gly]) as adsorbent. The effects of catalyst type, catalyst dosage, reaction time and temperature on the yield of cyclic carbonate were also investigated. The optimum conditions are 4 wt% of HP(0.6DVB-[VMOEim][Gly]) (based on the epichlorohydrin) as catalyst at 130 °C for 10 h, and the yield of 4-(chloromethyl)-1,3-dioxolan-2-one can reach 94%. Furthermore, the catalytic activity of HP(0.6DVB-[VMOEim][Gly]) maintains and the yield is 91% after five-cycle experiment. The mechanism of cycloaddition reaction was also discussed.

The purpose is to assess the diagnostic ability for early glaucoma of macular ganglion cell–inner plexiform layer (GCIPL) thickness in a Chinese population including glaucoma suspects. A total of 367 eyes with primary open-angle glaucoma (168 early glaucoma, 78 moderate glaucoma, and 121 advanced glaucoma), 52 eyes with ocular hypertension (OHT), 59 eyes with enlarged cup-to-disc ratio (C/D), and 225 normal eyes were included. GCIPL thickness (average, minimum, superotemporal, superior, superonasal, inferonasal, inferior, and inferotemporal), retinal nerve fiber layer (RNFL) thickness, and optic nerve head (ONH) parameters were measured using Cirrus high-definition optical coherence tomography (OCT) and compared. The diagnostic ability of OCT parameters was assessed by area under receiver operating characteristic curve (AUROC) in 3 distinguishing groups: normal eyes and eyes with early glaucoma, normal eyes and eyes with glaucoma regardless of disease stage, and nonglaucomatous eyes (normal eyes, eyes with OHT, and enlarged C/D) and early glaucomatous eyes. Glaucomatous eyes showed a significant reduction in GCIPL thickness compared with nonglaucomatous eyes. In all 3 distinguishing groups, best-performing parameters of GCIPL thickness, RNFL thickness, and ONH parameters were minimum GCIPL thickness (expressed in AUROC, 0.899, 0.952, and 0.900, respectively), average RNFL thickness (0.904, 0.953, and 0.892, respectively), and rim area (0.861, 0.925, and 0.824, respectively). There was no statistical significance of AUROC between minimum GCIPL thickness and average RNFL thickness (all P > .05). GCIPL thickness could discriminate early glaucoma from normal and glaucoma suspects with good sensitivity and specificity. The glaucoma diagnostic ability of GCIPL thickness was comparable to that of RNFL thickness.

Highlights • Glycyrrhizin inhibits PRRSV proliferation. • Glycyrrhizin mainly interferes with internalization stage in PRRSV life cycle. • Glycyrrhizin does not directly inactivate PRRSV particles., Glycyrrhizin is a natural component extracted from the roots of Glycyrrhiza glabra. In this study, we investigated the antiviral activity of glycyrrhizin against porcine reproductive and respiratory syndrome virus (PRRSV), an Arterivirus that has been devastating the swine industry worldwide since the late 1980s. Our results showed that treatment with glycyrrhizin significantly reduced PRRSV proliferation and PRRSV-encoded protein expression in a dose-dependent manner. Mechanistically, glycyrrhizin mainly inhibits the penetration stage, and has little effect on the steps of adsorption or release of PRRSV in its life cycle. Furthermore, we were able to exclude a direct inhibitory action of glycyrrhizin on PRRSV particles. Given these results, glycyrrhizin may be a candidate component for a novel porcine reproductive and respiratory syndrome (PRRS) control strategy.

Palladium-catalyzed carboamination reactions of N-allylguanidines bearing cleavable N-cyano or N-arylsulfonyl protecting groups are described. The reactions afford cyclic guanidine products in good yield, and transformations of substrates bearing internal alkenes proceed with high diastereoselectivity. Deuterium labeling studies indicate these transformations proceed via anti-aminopalladation pathways.

The development of anhydrous proton-conductive membranes operating at temperatures above 100 °C is a challenge for practical application. To meet the requirements, the N-(3-aminopropyl)-imidazole (NAPI), a proton-carrier molecule, is encapsulated in the frameworks of the Fe-MIL-101-NH 2 and then allowed to react with sulfonated poly (2,6-dimethyl-1,4-phenylene oxide) (SPPO) for preparing hybrid proton conductive membrane. Results showed that the dispersed proton conductive metal–organic frameworks (MOFs) in the membrane provide a convenient pathway for proton mobility under high temperature and anhydrous condition. Tuning of the host–guest interaction can generate a good proton-conducting pathway at temperatures above 150 °C. It is also presumed that the proton transfer in the membrane is simultaneously contributed from the Grotthuss-type mechanism and the vehicle-type mechanism. This work suggests that a combination of guest molecules and microporous frameworks could afford highly mobile proton carriers in solids. Therefore, the new proton conductive membranes can be designed by incorporating the MOFs into functionalized polymers for applications at high temperature and anhydrous condition.

A new enzymatic glucose biosensor based on reversible co-immobilization of horseradish peroxidase (HRP) and glucose oxidase (GOx) on a pH-responsive imprinted monolith is prepared. The poly(4-vinylphenylboronic acid)-grafted imprinted polymer using HRP as a template is formed via surface initiated atom transfer radical polymerization within the pores of brominated poly(glycidyl methacrylate-co-ethylene dimethacrylate) macroporous monolith contained in a 100 μm I.D. capillary column. The two enzymes conjugate is formed via the strong affinity interaction between biotin-labeled GOx and streptavidin-labeled HRP. The modulation of the external pH value enables reusability of the biosensor simply using stripping of the inactive enzymes at a low pH value and subsequent immobilization of fresh enzymes at a high pH value. Under the optimized conditions, the enzymatic biosensor features excellent performance in detection of glucose with a linear range of its concentration from 0.11 to 38.85 mmol/L and a limit of detection of 0.03 mmol/L. A relative standard deviation of 3.7% is calculated from determination of twenty glucose samples. This novel enzymatic sensing system is successfully applied for determination of glucose in human serum, and confirms an enhancement both in selectivity and specificity compared to the more traditionally clinical methods.

The diffusion dialysis (DD) of hydrochloric acids in presence of their different metal salts has been investigated with a two-compartment cell in the following systems: HCl + NaCl, HCl + FeCl2, HCl + NiCl2, HCl + CuCl2, HCl + ZnCl2, and HCl + AlCl3. The corresponding Cl− permeability coefficients (P) from an organic–inorganic hybrid anion exchange membrane are determined by a simple method. That is, the experimental ions concentrations in diffusate are fitted based on the mass transfer and ionic equilibrium equations, combined with an optimized procedure. The fitted P values for Cl− follow the order in the investigated concentration range: P Cl - total ( CuCl 2 ) ( 6.1 × 10 - 6 m / s ) > P Cl - total ( FeCl 2 ) ( 3.1 × 10 - 6 m / s ) > P Cl - total ( NiCl 2 ) ( 2.6 × 10 - 6 m / s ) > P Cl - total ( AlCl 3 ) ( 2.0 × 10 - 6 m / s ) > P Cl - total ( NaCl ) ( 1.6 × 10 - 6 m / s ) > P Cl - total ( ZnCl 2 ) ( 3.4 × 10 - 7 m / s ) This changing trend is then correlated with the metal–acid complexes formation as well as the physic-chemical properties of metal ions: Cu, Fe, Ni can promote the transport of chloride ions much more than Al and Na due to their positive or neutral complexes formation with Cl−, whereas, Zn shows apparent hindrance effect to DD at its high concentration because of the dissociation equilibrium of large amount of its negative complexes within the membrane. And compared with Al, Na shows less influence to HCl transport because of its lower valence. The complexes formations between metal ions with Cl− contribute much to DD effect, as reflected well by the P value. Our work here investigates and compares the permeability of Cl− ions in the systems with different metal salts through a simple and easy method. Therefore, the results and findings can provide clues for further DD developments and applications in metal industries.

A quantification of diffusion dialysis process in a single electrolyte system has been investigated in this study. Firstly, the volume of water which permeates from water side to feed side was to be quantified detailedly, and results showed that diffusate solution volume changes over time according with the characteristics of quadratic polynomial (y = a0τ2 + b0τ + c0). Secondly, Permeability coefficients of membrane to H2O ( P H 2 O , P H 2 O ′ ) and NaCl (PNaCl, P NaCl ′ ) were used to quantify diffusion dialysis process. Results showed that with the increase of feed concentration, P NaCl ′ and PNaCl decrease, while P H 2 O ′ and P H 2 O increase. Furthermore, when modifying factor λ = 3.30 and ϑ = 2.37, comparisons of theoretical and experimental concentrations of NaCl in diffusate solution illustrated that both P H 2 O ′ and P NaCl ′ are satisfactory coefficients for characterizing the diffusion dialysis process. In addition, the mathematical model discussed in this study can provide an effective method to deal with the mass transfer process of diffusion dialysis easily and conveniently, especially, is helpful to select an optimum ion exchange membrane to operate diffusion dialysis.

Hybrid membranes containing both –N + (CH 3 ) 3 Br − and –OH groups are prepared from quaternized poly(2,6-dimethyl-1,4-phenylene oxide) (QPPO) and polyvinyl alcohol (PVA). The QPPO and PVA are crosslinked with double crosslinking agents including monophenyl triethoxysilane (EPh) and tetraethoxysilane (TEOS) through sol–gel process. The double crosslinking agents are effective for the crosslinking in both QPPO and PVA phases. The hybrid membranes contain plenty of micropores but have no obvious silica particles. The membranes have the ion exchange capacities of 1.22–1.92 mmol/g, water uptake of 63–205%, the initial decomposition temperatures of 225–239 °C, and the swelling degrees in 65 °C water of 105–426%. The –OH groups of PVA can be regarded as assistant functional groups for the sorption of HCl and diffusion dialysis (DD) process. As the PVA content increases from 10% to 60%, the sorbed HCl concentration increases from 0.36 mol/L to 2.9 mol/L in HCl solution, while the sorption capacity is generally stable in the mixture of HCl and FeCl 2 . The dialysis coefficient of HCl ( U H ) increases from 0.021 m/h to 0.049 m/h, but the separation factor ( S ) decreases from 39 to 26. When compared with the commercial DF-120 membrane (0.009 m/h, 18.5), the QPPO/PVA hybrid membranes can be potentially applied in DD process for acid recovery.

By changing -COOH content in poly(acrylic acid-co-methacryloxypropyl trimethoxy silane (poly(AA-co-γ-MPS)), a series of PVA/SiO(2) cation exchange membranes are prepared from sol-gel process of poly(AA-co-γ-MPS) in presence of poly(vinyl alcohol) (PVA). The membranes have the initial decomposition temperature (IDT) values of 236-274 °C. The tensile strength (TS) ranges from 17.4 MPa to 44.4 MPa. The dimensional stability in length (DS-length) is in the range of 10%-25%, and the DS-area is in the range of 21%-56% in 65 °C water. The water content (W(R)) ranges from 61.2% to 81.7%, the ion exchange capacity (IEC) ranges from 1.69 mmol/g to 1.90 mmol/g. Effects of -COOH content on diffusion dialysis (DD) performance also are investigated for their potential applications. The membranes are tested for recovering NaOH from the mixture of NaOH/Na(2)WO(4) at 25 - 45 °C. The dialysis coefficients of NaOH (U(OH)) are in the range of 0.006-0.032 m/h, which are higher than those of the previous membranes (U(OH): 0.0015 m/h, at 25 °C). The selectivity (S) can reach up to 36.2. The DD performances have been correlated with the membrane structure, especially the continuous arrangement of -COOH in poly(AA-co-γ-MPS) chain.

Cation exchange multisilicon copolymers i.e. copolymers containing pendent siloxane and SO3Na groups are developed from the copolymerization of sodium styrene sulfonate (SSS) and γ-methacryloxypropyl trimethoxy silane (γ-MPS). The copolymerization process can proceed smoothly without formation of gel. The copolymers are compatible with water, and can produce transparent and homogeneous solutions when mixed with poly(vinyl alcohol) (PVA), so that transparent and compact hybrid membranes are obtained. The membranes are thermally and mechanically stable, with initial decomposition temperatures of 237–273 °C, tensile strength of 9.1–26.0 MPa and elongation at break of 12.4–21.1%. The membranes have a water uptake (WR) of 30.0–54.8% and swelling degrees of 46–115% in 65 °C water, which are mainly controlled by the content of Si(OCH3)3 groups in the mutlisilicon copolymers. Diffusion dialysis (DD) separation of NaOH/Na2WO4 solution indicates that the alkali dialysis coefficients (UOH) are in the range of 0.010–0.011 m/h, higher than the values of commercial membrane (0.00137 m/h) and other polymer based hybrid membranes (0.0014–0.0022 m/h). The membrane structure and properties are correlated with the ions transport mechanism, revealing interesting findings as to the influence of IEC and different functional groups on DD behavior.

One multisilicon copolymer, i.e. a copolymer containing pendent siloxane and anhydride groups is prepared from the copolymerization of maleic anhydride (MA) and methacryloxypropyl trimethoxy silane (γ-MPS). Thereafter, it is used for the preparation of hybrid membranes through in situ sol–gel process in poly(vinyl alcohol) (PVA) solution. The anhydride groups in MA are less hydrophilic as compared with acidic carboxylic acid (–COOH) groups. Hence the copolymerization process can be more easily controlled without formation of gel. During the sol–gel process, the anhydride groups hydrolyze to generate geminal –COOH groups, which provide the membranes with relatively high cation exchange capacities (CECs) that can be applied for the diffusion dialysis process to recover NaOH from the mixture of NaOH/Na2WO4. The membranes have the initial decomposition temperature (IDT) of 227–243 °C, tensile strength (TS) of 14.2–28.3 MPa and elongation at break (Eb) of 18.8–67.3%. In addition, water swelling decreases as the content of multisilicon copolymer increases despite the increasing of the IEC values, which is attributed to the gradually strengthened crosslinking between PVA and the copolymer components. At 20 °C, UOH (the dialysis coefficients of OH− ions) are in the range of 0.0095–0.0123 m/h, and the separation factor (S) values are in the range of 28.4–54.4. The UOH values are significantly higher than the values of the commercial membrane (0.00137 m/h) and other polymer based hybrid membranes (0.0014–0.0022 m/h). This is due to the unique membrane structure and the presence of different functional groups. PVA provides hydrophilic matrix and hence the membranes cannot be classified into the common “three-phase” structure membranes. The presence of –OH groups assists and enhances the transport of OH− ions.

Cation exchange hybrid membranes for diffusion dialysis (DD) purpose have been prepared from sol–gel process of multi-alkoxy silicon copolymer (poly(vinyl benzyl chloride-γ-methacryloxypropyl trimethoxy silane)—poly(VBC-co-γ-MPS)) in presence of sulfonated poly(2,6-dimethyl-1,4-phenylene oxide) (SPPO). The hybrid membranes possess high thermal stability, mechanical strength, strong alkali and swelling resistance. Thermal initial decomposition temperatures are in the range of 233–245 °C. Tensile strength (TS) ranges from 23 MPa to 41 MPa and elongation at break (Eb) is in the range of 11–50%. The swelling behavior of the membranes is better suppressed as poly(VBC-co-γ-MPS) content increases. The hybrid membranes have been successfully applied for DD recovery of sodium hydroxide (NaOH) from the mixture of NaOH and sodium tungstate (Na2WO4). The separation factor (S) of hybrid membranes can reach as high as 301.5 at 25 °C. The pure SPPO membrane, as a comparison membrane, exhibits much lower S value of 36.2.

The recovery of acetic acid from simulated acetaldehyde wastewaters by BMED (bipolar membrane electrodialysis) process was studied in two steps. Firstly, selection of commercial membranes for acetic acid recovery was investigated through experimentation of diffusion dialysis, determination of membrane stability in acetic acid solution, and measurement of MER (membrane electrical resistance) of monomembranes and EIS (electrochemical impedance spectroscopy) of bipolar membranes. The results showed that Neosepta AMX and CMX membranes are the optimum monomembranes for BMED, and any bipolar membrane is suitable. Secondly, an improved BMED process was performed by changing the current density, adjusting the number of membranes, adding ion exchange resin in the cell, and including an additional cation exchange membrane. With the selected membranes, the optimum experimental condition in the BMED process was achieved, when two pieces of Neosepta AMX membranes and a current density of 10 mA/cm2 was adopted. Furthermore, the addition of a strong acid 001 type cation exchange resin into the feed compartment and a strong base 201 type gel anion exchange resin into the cathode compartment could substantially decrease the voltage drop across the membrane stack and reduce corresponding energy consumption. Finally, a low energy consumption of 0.61 kWh/kg and a relatively high current efficiency of 56.72% were achieved for acetic acid recovery under the optimum condition.

The diffusion dialysis (DD) processes of different inorganic acids in the presence of their corresponding sodium salts have been investigated with a two-compartment cell in the following systems: HCl + NaCl, H2SO4 + Na2SO4 and H3PO4 + Na3PO4. The permeability coefficients (P) of anions (Cl−, S O 4 2 − , or P O 4 3 − ) from a novel organic–inorganic hybrid anion exchange membrane are determined by a simple method. Namely, the concentration of the ions at water side is determined and then fitted based on the mass transfer and ionic equilibrium equations, combined with an optimized procedure. The fitted P values for the three anions follow the order in the investigated concentration range: P S O 4 2 − total ( 2.5 × 10 − 6 m/s ) > P C l − total ( 1.6 × 10 − 6 m/s ) > P P O 4 3 − total ( 1.0 × 10 − 7 m/s ) . This changing trend is then correlated with the physic-chemical characterizations, adsorptive and transporting properties of HCl, H2SO4 and H3PO4 in membrane: with the anion's size and charge increasing, its adsorption amount increases, while its diffusivity decreases due to the decreased water molecules and the enhanced electrostatic interaction between the anions and the fixed groups. The balance of adsorption and diffusivity determines the DD effect, as reflected well by the P values. Our work here investigates and compares the permeability of different inorganic acids through the application of a simple and easy method. Therefore, the results and findings can give clues for further development and applications of DD.

Diffusion dialysis (DD) is an ion-exchange membrane (IEM) separation process driven by concentration gradient and has been applied for separation and recovery of acid/alkali waste solutions in a cost-effective and environmentally friendly manner. This review of DD covers the principles, models, applications (strong acid/weak acid/alkali separation and recovery), and its integration with other techniques, such as electrodialysis, ion exchange membrane-electrowinning, continuous membrane extraction, vacuum membrane distillation, and ceramic membrane micro-filtration. Notably, different factors including properties of the membranes, nature of the waste solution and running conditions are discussed and correlated with the DD performances.

Anion exchange hybrid membranes have been prepared from quaternization and sol–gel reaction of multi-alkoxy silicon copolymer (poly(vinylbenzyl chloride-γ-methacryloxypropyl trimethoxy silane) (poly(VBC-co-γ-MPS)) in presence of poly(vinyl alcohol) (PVA). The membranes are of high thermal stability, mechanical strength, and swelling resistance. Thermal degradation temperatures ( T d , defined as the temperature at 5% weight loss) are in the range of 263–283 °C. Tensile strength (TS) ranges from 24.5 MPa to 59.2 MPa and elongation at break ( E b ) is in the range of 25.4–101.2%. The membranes can remain integrity in 65 °C hot water for more than 25 days and the swelling behavior is better suppressed as poly(VBC-co-γ-MPS) content increases. The membranes are tested for diffusion dialysis (DD) recovery of hydrochloric acid (HCl) from the mixture of HCl and ferrous chloride (FeCl 2 ). The temperature for DD process ranged from 20 °C to 60 °C, revealing that the separation factor ( S ) values are in the range of 12.1–35.7, comparable to the values of commercial DF-120 membranes. When the temperature increases from 20 °C to 30 °C, the separation performances are increased. Further increase of temperature increases the dialysis coefficients, but decreases the S value. The membrane structure and properties are correlated with the DD performances.

Membranes for diffusion dialysis (DD) purpose have been mostly based on organic polymer materials up to now. Here, poly(2,6-dimethyl-1,4-phenylene oxide) (PPO)–SiO 2 hybrid membranes, which are produced from hydroxylation, quaternization and sol–gel reaction of brominated PPO, have been successfully applied for DD recovery of hydrochloride acid (HCl) from the mixture of HCl and ferrous chloride (FeCl 2 ). The temperature for DD process is ranged from 15 °C to 65 °C and the results show that the hybrid membranes can have better separation performances under higher temperature. Separation factor ( S ) of hybrid membranes increases to as high as 41 as the temperature increases. The commercial polymer membrane DF-120, as a comparison membrane, exhibits much lower S values as the temperature changes. The physico-chemical structure and properties of the hybrid membranes are investigated and related with DD results, indicating that the inorganic silica network contributes much to the enhanced selectivity, especially at higher temperatures. Findings here show the success of organic–inorganic hybrid membranes in DD application field and may provide clues for their further explorations.

Bionic multisilicon copolymers have long-main chains and many branched chains, and contain multifunctional groups of -N(+)(CH(3))(3)Cl(-) and -Si(OCH(3))(3), which are similar to the stem, branch, fruit, and acetabula of a vine from bionic aspect, respectively. They have high flexibility, charge density, and cross-linking ability and thus can be used as novel cross-linking agents for preparing anion-exchange hybrid membranes. High content of -Si(OCH(3))(3) groups (68-78%) is suitable to enhance membrane stabilities. The membranes are stable in 65 °C water up to 120 h and can keep integrity in 2 mol/L NaOH for 192 h. High content of -N(+)(CH(3))(3)Cl(-) groups (42-55%) is suitable to enhance membrane electrical properties. The membranes have low membrane resistance (R(m), 0.59-0.94 Ω cm(2)) and high diffusion dialysis performance. The acid (H(+)) dialysis coefficients (U(H)) are in the range of 0.007-0.075 m h(-1) at room temperature and 0.015-0.115 m h(-1) at 40 °C. The separation factor (S(H/Fe)) can reach up to 43 at room temerature and 49 at 40 °C. All of the membranes are highly homogeneous, mechanically stable (21-31 MPa, 25-147%), and thermally stable (227-275 °C for halide form membranes, and 157-172 °C for OH(-) form membranes). Hence, the investigation of multisilicon copolymers will give rise to a new developing field in material and membrane sciences.