Polyvinyl alcohol/phytic acid/phosphorylated chitosan hydrogel electrode highly efficient electroadsorption of low concentration uranium from uranium tailings leachate.

In order to improve the removal rate of uranium and reduce the harm of radioactive pollution, a physically crosslinked polyvinyl alcohol/phosphorylated chitosan (PPP) hydrogel electrode was designed by freezing thawing method. The results show that PPP hydrogel has a good adsorption effect on uranium, and 200 mL of uranium tailings leachate is absorbed, and the treatment efficiency reaches 100 % within 15 min. PPP hydrogel can adapt to a wide range of pH conditions and exhibit excellent adsorption efficiency in the range of 3-9. At the same time, PPP hydrogel maintains an adsorption efficiency of over 85 % for 950 mg/L uranium solution. This lays the foundation for the practical application of PPP hydrogel. In addition, PPP hydrogel also exhibits good repeatability, after 7 cycles, the material still retains 95 % of its initial performance. The synergistic effect of various functional groups such as phosphate, hydroxyl, and ammonium in the material is the main mechanism of PPP's adsorption capacity for uranium. Furthermore, electrochemical adsorption method significantly enhances the adsorption performance of PPP hydrogel.

Preparation of novel polyvinyl alcohol-carbon nanotubes containing imidazolyl ionic liquid/chitosan hydrogel for highly efficient uranium extraction from seawater.

A novel polyvinyl alcohol-carbon nanotube containing an imidazolyl ionic liquid/chitosan composite hydrogel (termed CBCS) was prepared for highly selective uranium adsorption from seawater. The results show that CBCS has good adsorption properties for uranium within the pH range of 5.0-8.0. Kinetics and thermodynamics experiments show that the theoretical maximum adsorption capacity of CBCS to U(VI) is 496.049 mg/g (288 K, pH = 6.0), indicating a spontaneous exothermic reaction. Mechanism analysis shows that the hydroxyl group, amino group, and CN bond on the surface of CBCS directly participate in uranium adsorption and that the dense pores on the surface of CBCS play an important role in uranium adsorption. The competitive adsorption experiment shows that CBCS has excellent uranium adsorption selectivity. In addition, CBCS exhibits good reusability. After five adsorption-desorption cycles, the uranium adsorption rate of CBCS can still reach >98 %. Hence, CBCS has excellent potential for uranium extraction from seawater.

Selective, rapid extraction of uranium from aqueous solution by porous chitosan-phosphorylated chitosan-amidoxime macroporous resin composite and differential charge calculation.

Herein, a new porous chitosan-phosphorylated chitosan-amidoxime macroporous resin composite (PCAR) was designed and synthesized for the rapid and selective extraction of uranium resources from aqueous solution. This study showed that PCAR exhibited excellent adsorption toward uranium in a pH range of 5-9. The dynamic adsorption process aligned with the quasi-second-order kinetic model and corresponded to the chemical adsorption process. The maximum adsorption capacity was 561.28 mg·g-1 at pH 6 and 308 K. Mechanism analysis showed that the synergistic effect of the amidoxime group (-(NH2)C=N-OH), PO, and -NH2 on the PCAR surface improved the uranium adsorption performance. The differential charge density indicated that the amidoxime and phosphate groups provide lone-pair electrons for the adsorption of UO22+ and their synergistic effect improves the UO22+ adsorption performance of PCAR. The uranium distribution coefficients of PCAR and CAR are 4.6 and 2.4 times those of vanadium, respectively. These results indicate that phosphorylation can ameliorate the disadvantage of competitive vanadium adsorption of the amidoxime adsorbent. In addition, PCAR exhibits good reusability and stable adsorption capacity after five adsorption-desorption cycles. Hence, PCAR has excellent potential for uranium extraction from aqueous solution.

Phosphorylation improved the competitive U/V adsorption on chitosan-based adsorbent containing amidoxime for rapid uranium extraction from seawater.

A novel chitosan-based porous composite adsorbent with multifunctional groups, such as phosphoric acid, amidoxime, and quaternary ammonium groups, was prepared to improve the adsorption rate and competitive uranium­vanadium adsorption of amidoxime group adsorbents. The maximum uranium adsorption capacity of PACNC was 962.226 mg g-1 at 308 K and pH = 7. The maximum adsorption rate constant of PACNC for uranium was 2.83E-2 g mg-1 min-1, which is 2.38 times that of ACNC (1.19E-2 g mg-1 min-1). Moreover, the adsorption equilibrium time was shortened from 300 (ACNC) to 50 (PACNC) min. In simulated and real seawater, the Kd and adsorption capacity of PACNC for uranium were approximately 8 and 6.62 times those for vanadium, respectively. These results suggest that phosphorylation significantly improved the competitive adsorption of uranium­vanadium and uranium adsorption rate. PACNC also exhibited good recycling performance and maintained stable adsorption capacity after five cycles. DFT calculations were used to analyze and calculate the possible co-complex structure of PACNC and uranium. The binding structure of phosphate and amidoxime is the most stable, and its synergistic effect effectively improves the competitive adsorption of uranium-vanadium of amidoxime. All the results demonstrated that PACNC has substantial application potential for uranium extraction from seawater.

Enhanced performance in uranium extraction by the synergistic effect of functional groups on chitosan-based adsorbent.

In this study, a novel sponge phosphoric acid functionalized porous composite adsorbent (named SPCCHC) was prepared from chitosan and chlorella hydrothermal charcoal. Kinetics and thermodynamics experiments showed that the theoretical maximum adsorption capacity of SPCCHC to U(VI) is 579.27 mg/g (288 K, pH = 6.5), indicating a spontaneous exothermic reaction. SPCCHC showed good adsorption selectivity for uranium in the adsorption studies of simulated seawater and a mixed solution of uranium-vanadium. The characterization of SPCCHC before and after U(VI) adsorption proves that the introduction of the phosphate group can greatly improve the adsorption effect of the adsorbent on uranium, particularly the distribution coefficients of uranium and vanadium differ by up to 89.5 times. At the same time, SPCCHC has good recycling performance, which is expected to be used in natural seawater uranium extraction.

Potential Molecular Mechanisms of Ephedra Herb in the Treatment of Nephrotic Syndrome Based on Network Pharmacology and Molecular Docking.

Objective: To explore the possible mechanisms of Ephedra herb (EH) in the treatment of nephrotic syndrome (NS) by using network pharmacology and molecular docking in this study. Methods: Active ingredients and related targets of EH were obtained from the Traditional Chinese Medicine Systems Pharmacology (TCMSP) database, and the gene names corresponding to the proteins were found through the UniProt database. Then, target genes related to NS were screened out from GeneCards, PharmGKB, and OMIM databases. Next, the intersection targets were obtained successfully through Venn diagram, which were also seen as key target genes of EH and NS. Cytoscape 3.9.0 software was used to construct the effective "active ingredient-target" network diagram, and "drug-ingredient-target-disease (D-I-T-D)" network diagram. After that, the STRING database was used to construct a protein-protein interaction (PPI) network. Furthermore, Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment involved in the targets were performed by the DAVID database and ClueGO plugin in Cytoscape. Finally, AutoDockTools software was used for molecular docking to verify the binding strength between main active ingredients and key target proteins. Results: A total of 22 main active ingredients such as quercetin, kaempferol, luteolin, and naringenin were obtained, which could act on 105 targets related to NS. Through PPI network, 53 core targets such as AKT1, TNF, IL6, VEGFA, and IL1B were found, which might play a crucial role in the treatment of NS. Meanwhile, these targets were significantly involved in PI3K-Akt signaling pathway, TNF signaling pathway, AGE-RAGE signaling pathway, hepatitis B, and pathways in cancer through GO and KEGG enrichment analysis. The docking results indicated that active ingredients such as kaempferol, luteolin, quercetin, and naringenin all had good binding to the target protein AKT1 or TNF. Among them, luteolin and naringenin binding with AKT1 showed the best binding energy (-6.2 kcal/mol). Conclusion: This study indicated that the potential mechanism of EH in treating NS may be related to PI3K-Akt signaling pathway, TNF signaling pathway, and AGE-RAGE signaling pathway, which provided better approaches for exploring the mechanism in treating NS and new ideas for further in vivo and in vitro experimental verifications.

Adsorption of uranium by chitosan/Chlorella pyrenoidosa composite adsorbent bearing phosphate ligand.

In order to remove and recover uranium from acidic uranium-bearing wastewater in uranium mining and metallurgy. Herein, a novel chitosan/Chlorella pyrenoidosa composite adsorbent bearing phosphate ligand (CSP/CP) was designed and synthesized, demonstrating a high uranium adsorption capacity at a pH of 5 and excellent selectivity in an aqueous solution with eight coexisting ions. The CSP/CP exhibits a maximum adsorption capacity (1393.338 mg g-1) and selectivity (Su = 80.53%) for uranium, which is higher than many reported adsorbents. Mechanism analysis shows that the surface of CSP/CP is rich in hydroxyl, amino, phosphate and carboxyl groups, resulting in an excellent three-dimensional structure with active sites for high-performance uranium adsorption; U(VI) is selectively bound via ion exchanges with -COOH and -OH and through surface complexation with NH2 and PO. Furthermore, by desorption with 0.1 M Na2CO3 + 2% H2O2 at 318 K, CSP/CP can be recycled more than five times. It provides a new scientific basis for the preparation of high selectivity composite adsorbent by chitosan.

Efficiency and mechanism of adsorption of low-concentration uranium from water by a new chitosan/aluminum sludge composite aerogel.

A new chitosan/aluminum sludge composite aerogel (CS/ASca) exhibiting good selectivity, easy separation potential, and high adsorption capacity was synthesized by combining chitosan (CS) and aluminum sludge from waterworks (AS). The adsorption of U(vi) by the CS/ASca was assessed as a function of solution pH, adsorption time, temperature, initial concentrations of uranium, and coexisting ions. The systematic batch experiments reveal that the adsorption kinetics is described by a pseudo-second-order model, and the sorption thermodynamics involves spontaneous endothermic processes. At a pH of 4, 308 K, and initial uranium concentrations of 10-700 mg L-1, the maximum adsorption capacity of the CS/ASca for U(vi) (simulated by the Langmuir model) was 434.64 mg g-1. Data from scanning electron microscopy/energy dispersive spectrometry, Fourier-transform infrared, and X-ray photoelectron spectroscopy indicated that uranyl ion adsorption was predominantly associated with the complexation of U(vi) with the amino and hydroxyl groups on the surface of the CS/ASca. In addition, our results demonstrated that the Mg(ii), Pb(ii), Na(i), and K(i) ions had little or no effect on the sorption of U(vi) on the CS/ASca. This study provides new clues for the treatment of radioactive wastewater.

Inhibition of mTOR promotes hyperthermia sensitivity in SMMC-7721 human hepatocellular carcinoma cell line.

The mammalian target of rapamycin (mTOR) is a critical mediator of the phosphoinositide 3-kinase/protein kinase B/mTOR signaling pathway, and mTOR activity is induced following heat shock. Thermotherapy is used to treat hepatocellular carcinoma (HCC). However, the role of mTOR in modulating thermosensitivity in HCC has yet to be elucidated. In the present study, the antisense plasmid pEGFP-C1-mTOR was transfected into SMMC-7721 cells, and the expression levels of mTOR were analyzed by reverse transcription-polymerase chain reaction and western blot analysis. The thermal responses of the transfected cells were also examined. The results revealed that SMMC-7721 cells were sensitive to heat treatment, and cell viability was significantly inhibited following hyperthermia treatment (P<0.01). The mRNA and protein expression levels of mTOR decreased post-transfection. Cell proliferation, colony-forming ability and motility were all significantly decreased following hyperthermia treatment in the transfected cells. Flow cytometry analysis demonstrated that apoptosis was significantly increased following treatment (P<0.01). The number of cells in S phase was increased, and the cell cycle was arrested in S phase. In conclusion, inhibition of mTOR increased the thermosensitivity of SMMC-7721 cells by increasing cellular apoptosis and inducing S phase arrest.

Study on biosorption kinetics and thermodynamics of uranium by Citrobacter freudii.

Biosorption has been developed as an effective and economic method to treat wastewater containing low concentrations of metal pollutants. In this study, a bacterium, Citrobacter freudii, was used as a biosorbent to adsorb uranium ions. The thermodynamics and kinetics of this adsorption, as well as its mechanism, were investigated. The results indicated that the biosorption rate could be better described by a pseudo 2nd-order model than a pseudo 1st-order model. The adsorption of U (VI) proceeded very rapidly in the first 30min and subsequently slowed down continuously for a long period. The biosorption isotherm of uranium by C. freudii could be described well by the Langmuir or Freundlich isotherm, and the latter was better. The thermodynamics parameters, DeltaH degrees , DeltaG degrees , and DeltaS degrees were calculated according to the results of the experiment, which showed this biosorption as being endothermic and spontaneous. The authors investigated the active sites of bacteria for biosorption and the results proved that carboxyl in the cell wall played an important role in biosorption.