Density Functional Theory Studies on the Structures and Water-Exchange Reactions of Aqueous Al(III)–Oxalate Complexes

The structures and water-exchange reactions of aqueous aluminum-oxalate complexes are investigated using density functional theory. The present work includes (1) The structures of Al(C2O4)(H2O)4+ and Al(C2O4)2(H2O)2– were optimized at the level of B3LYP/6-311+G(d,p). The geometries obtained suggest that the AlOH2 bond lengths trans to C2O42‑ ligand in Al(C2O4)(H2O)4+ are much longer than the AlOH2 bond lengths cis to C2O42‑. For Al(C2O4)2(H2O)2–, the close energies between cis and trans isomers imply the coexistence in aqueous solution. The 27Al NMR and 13C NMR chemical shifts computed with the consideration of sufficient solvent effect using HF GIAO method and 6-311+G(d,p) basis set are in agreement with the experimental values available, indicating the appropriateness of the applied models; (2) The water-exchange reactions of Al(III)–oxalate complexes were simulated at the same computational level. The results show that water exchange proceeds via dissociative pathway and the activation energy barriers are sensitive to the solvent effect. The energy barriers obtained indicate that the coordinated H2O cis to C2O42‑ in Al(C2O4)(H2O)4+ is more labile than trans H2O. The water-exchange rate constants (kex) of trans- and cis-Al(C2O4)2(H2O)2– were estimated by four methods and their respective characteristics were explored; (3) The significance of the study on the aqueous aluminum-oxalate complexes to environmental chemistry is discussed. The influences of ubiquitous organic ligands in environment on aluminum chemistry behavior can be elucidated by extending this study to a series of Al(III)–organic system

Sex-determining Region Y-box transcription factor 13 promotes breast cancer cell proliferation and glycolysis by activating the tripartite motif containing 11-mediated Wnt/β-catenin signaling pathway

Breast cancer is the most frequent cancer among women and the second highest mortality in female across the world. Recent studies have illustrated that sex-determining region Y (SRY)-box protein (SOX) family plays essential roles in regulating various cancers. Nevertheless, the detailed effects of SOX13 on breast cancer are still uncovered. In our present study, SOX13 protein level was measured by using western blot assay in tissues and cells, and the results showed that SOX13 was upregulated in breast cancer tissues and cells compared with normal samples. Moreover, silencing SOX13 inhibited breast cancer cell viability, arrested cell cycle at G1/S phase and suppressed glycolysis, while overexpression of SOX13 reversed these events. Additionally, SOX13 knockdown reduced the level of proteins related to Wnt/β-catenin signaling pathway, whereas overexpression of tripartite motif containing 11 (TRM11) efficiently attenuated the effects, indicating that SOX13 controlled Wnt/β-catenin pathway depending on TRIM11. Furthermore, the data gained from xenograft tumor model illustrated that silencing SOX13 suppressed the tumor growth in nude mice and the glycolysis of tissues. In conclusion, our investigation illustrated that SOX13 facilitated breast cancer cell proliferation and glycolysis by modulating Wnt/β-catenin signaling pathway affected via TRIM11.</p

Density Functional Theory Study on Aqueous Aluminum−Fluoride Complexes: Exploration of the Intrinsic Relationship between Water-Exchange Rate Constants and Structural Parameters for Monomer Aluminum Complexes

Density functional theory (DFT) calculation is carried out to investigate the structures, 19F and 27Al NMR chemical shifts of aqueous Al−F complexes and their water-exchange reactions. The following investigations are performed in this paper: (1) the microscopic properties of typical aqueous Al−F complexes are obtained at the level of B3LYP/6-311+G**. AlOH2 bond lengths increase with F− replacing inner-sphere H2O progressively, indicating labilizing effect of F− ligand. The Al−OH2 distance trans to fluoride is longer than other AlOH2 distance, accounting for trans effect of F− ligand. 19F and 27Al NMR chemical shifts are calculated using GIAO method at the HF/6-311+G** level relative to F(H2O)6− and Al(H2O)63+ references, respectively. The results are consistent with available experimental values; (2) the dissociative (D) activated mechanism is observed by modeling water-exchange reaction for [Al(H2O)6-iFi](3−i)+ (i = 1−4). The activation energy barriers are found to decrease with increasing F− substitution, which is in line with experimental rate constants (kex). The log kex of AlF3(H2O)30 and AlF4(H2O)2− are predicted by three ways. The results indicate that the correlation between log kex and AlO bond length as well as the given transmission coefficient allows experimental rate constants to be predicted, whereas the correlation between log kex and activation free energy is poor; (3) the environmental significance of this work is elucidated by the extension toward three fields, that is, polyaluminum system, monomer Al-organic system and other metal ions system with high charge-to-radius ratio

Additional file 1 of Factors influencing depression in community-dwelling elderly patients with osteoarthritis of the knee in China: a cross-sectional study

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Influence of Monolayered RuO₂ Nanosheets and Co²⁺ Ion Linkers in Improving the Electrocatalytic Performance of MoS₂ Nanoflowers

Hybridization between low-dimensional nanostructures has received considerable research interest, owing to its usefulness in the exploration of energy-efficient functional materials. In the present study, an effective method to synthesize high-performance electrocatalysts was established by employing monolayered two-dimensional RuO2 nanosheets and Co2+ ions as conductive additives and linker species, respectively. Intimately coupled hybrid electrocatalysts of Co–MoS2–RuO2 were synthesized through the self-assembly of isocharged MoS2 nanoflowers and RuO2 nanosheets using oppositely charged Co2+ linkers. Efficient interfacial charge transfer from RuO2 nanosheets to MoS2 nanostructures can be achieved via electrostatically driven strong electronic coupling between MoS2/RuO2 nanostructures promoted by Co2+ linkers. The co-incorporation of RuO2 nanosheets and Co2+ ion linkers was found to be considerably effective for optimization of the electrocatalyst performance and electrochemical stability of MoS2 nanoflowers for the hydrogen evolution reaction in acidic and alkaline electrolytes. The beneficial roles of RuO2 nanosheets and Co2+ ions in the optimization of the electrocatalyst performance were attributable to the improvement of electrocatalysis kinetics, the expansion of the electrochemical active surface area, and the promotion of charge transport upon hybridization

Atomically Thin Holey Two-Dimensional Ru₂P Nanosheets for Enhanced Hydrogen Evolution Electrocatalysis

The defect engineering of low-dimensional nanostructured materials has led to increased scientific efforts owing to their high efficiency concerning high-performance electrocatalysts that play a crucial role in renewable energy technologies. Herein, we report an efficient methodology for fabricating atomically thin, holey metal-phosphide nanosheets with excellent electrocatalyst functionality. Two-dimensional, subnanometer-thick, holey Ru2P nanosheets containing crystal defects were synthesized via the phosphidation of monolayer RuO2 nanosheets. Holey Ru2P nanosheets exhibited superior electrocatalytic activity for the hydrogen evolution reaction (HER) compared to that exhibited by nonholey Ru2P nanoparticles. Further, holey Ru2P nanosheets exhibited overpotentials of 17 and 26 mV in acidic and alkaline electrolytes, respectively. Thus, they are among the best-performing Ru–P-based HER catalysts reported to date. In situ spectroscopic investigations indicated that the holey nanosheet morphology enhanced the accumulation of surface hydrogen through the adsorption of protons and/or water, resulting in an increased contribution of the Volmer–Tafel mechanism toward the exceptional HER activity of these ultrathin electrocatalysts

Additional file 2 of Factors influencing depression in community-dwelling elderly patients with osteoarthritis of the knee in China: a cross-sectional study

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Additional file 1 of The risk of malignancy in patients with IgG4-related disease: a systematic review and meta-analysis

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Additional file 2 of The risk of malignancy in patients with IgG4-related disease: a systematic review and meta-analysis

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Density Functional Investigation of the Water Exchange Reaction on the Gibbsite Surface

The water exchange reactions on the gibbsite surface have been investigated by density functional calculations (B3LYP/6-31G(d) level) combining the supermolecular model and PCM model in this paper, and the water exchange rate constants on the gibbsite surface have also been predicted. In the proposed reaction pathways, the clusters Al6(OH)18(H2O)60 and Al6(OH)12(H2O)126+ are used as the models of gibbsite surface and protonated gibbsite surface respectively to examine the effect of protonation of gibbsite surface on the water exchange rate constants. The activation energy barriers ΔEs≠(aq) for Al6(OH)18(H2O)60 and Al6(OH)12(H2O)126+ are 28.6 and 27.2 kJ mol−1, respectively. The reaction energies ΔEs(aq) for Al6(OH)18(H2O)60 and Al6(OH)12(H2O)126+ are 2.9 and 14.4 kJ·mol−1, respectively, indicating that hexacoordinate aluminum in the gibbsite surface is more stable. The log kTST for Al6(OH)18(H2O)60 and Al6(OH)12(H2O)126+ are 6.5 and 7.5 respectively, and the log kex calculated by the given transmission coefficient for Al6(OH)18(H2O)60 and Al6(OH)12(H2O)126+ are 2.4 and 3.4 respectively, indicating that the protonation of gibbsite surface promotes the water exchange reaction of gibbsite surface and accelerates the dissolution rate of gibbsite. The relationship between the calculated free energy and experimental rate constants was explored, and according to this relationship, the log kex for Al6(OH)18(H2O)60 and Al6(OH)12(H2O)126+ are 2.5 and 3.1 respectively, close to the corresponding values calculated by the given transmission coefficient. The water exchange rate constant of gibbsite surface is close to those of K−MAl12(M = Al, Ga, and Ge) polyoxocations, but deviates from that of Al(H2O)63+, implying that the same reactions with similar structure have similar water exchange rate constants