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Sulfonated polysulfone proton exchange membrane with flexible side chains for fuel cells
Zongwen Qiao,Jiaqi Deng,Tao Chen 한국고분자학회 2024 Macromolecular Research Vol.32 No.2
In this study, chloromethylated polysulfones (CPS) were used as precursors to synthesize two kinds of sulfonated polysulfones with flexible side chains, namely PS-BS (The end of the side chain contains a sulfonic acid group) and PS-BDS (The end of the side chain contains two sulfonic acid groups). This was achieved through nucleophilic substitution reaction using sodium 4-hydroxybenzenesulfonate and disodium 1,2-dihydroxybenzene-3,5-disufonate as nucleophilic reagents, respectively. The chemical structures of the resulting sulfonated polysulfones were characterized using the Fourier infrared spectrum (FT-IR) and nuclear magnetic hydrogen spectrum ( H1-NMR). The proton exchange membranes (PEMs) were fabricated using a solution casting method. Thermogravimetric analysis (TGA) analysis revealed that the obtained PEMs exhibited stability up to 270 °C. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) analysis indicated that PS-BS and PS-BDS PEMs exhibited a clear microphase separation structure, with the hydrophilic sulfonic acid groups located far away from the hydrophobic main chain of PS. This unique structure contributed to improved dimensional stability and oxidative stability of the PEMs. The obtained PEMs show better dimensional stability and oxidative stability. Comparing the two types of PEMs at the same temperature and ion exchange capacity (IEC), PS-BDS PEMs demonstrate better dimensional stability and lower methanol permeability compared to PS-BS PEMs. For instance, PD-BDS-4 PEMs exhibited a dimensional of stability up to 8.6% at room temperature and 30% at 85 °C. The corresponding methanol permeability was 10.29 × 10– 7 cm2/ s at 25 °C, which was significantly lower than that of Nafion112 (10.5 × 10– 7 cm2/ s) PEMs under the same condition.
Zhou, Xiaofeng,He, Yingting,Jiang, Yao,He, Bo,Deng, Xi,Zhang, Zhe,Yuan, Xiaolong,Li, Jiaqi Asian Australasian Association of Animal Productio 2020 Animal Bioscience Vol.33 No.6
Objective: Numerous studies have indicated that the apoptosis and proliferation of granulosa cells (GCs) are closely related to the normal growth and development of follicles and ovaries. Previous evidence has suggested that miR-126-3p might get involved in the apoptosis and proliferation of GCs, and phosphatidylinositol 3-kinase regulatory subunit 2 (PIK3R2) gene has been predicted as one target of miR-126-3p. However, the molecular regulation of miR-126-3p on PIK3R2 and the effects of PIK3R2 on porcine GCs apoptosis and proliferation remain virtually unexplored. Methods: In this study, using porcine GCs as a cellular model, luciferase report assay, mutation and deletion were applied to verify the targeting relationship between miR-126-3p and PIK3R2. Annexin-V/PI staining and 5-ethynyl-2'-deoxyuridine assay were applied to explore the effect of PIK3R2 on GCs apoptosis and proliferation, respectively. Real-time quantitative polymerase chain reaction and Western Blot were applied to explore the regulation of miR-126-3p on PIK3R2 expression. Results: We found that miR-126-3p targeted at PIK3R2 and inhibited its mRNA and protein expression. Knockdown of PIK3R2 significantly inhibited the apoptosis and promoted the proliferation of porcine GCs, and significantly down-regulated the mRNA expression of several key genes of PI3K pathway such as insulin-like growth factor 1 receptor (IGF1R), insulin receptor (INSR), pyruvate dehydrogenase kinase 1 (PDK1), and serine/threonine kinase 1 (AKT1). Conclusion: MiR-126-3p might target and inhibit the mRNA and protein expressions of PIK3R2, thereby inhibiting GC apoptosis and promoting GC proliferation by down-regulating several key genes of the PI3K pathway, IGF1R, INSR, PDK1, and AKT1. These findings would provide great insight into further exploring the molecular regulation of miR-126-3p and PIK3R2 on the functions of GCs during the folliculogenesis in female mammals.
Energy spread minimization in a cascaded laser wakefield accelerator via velocity bunching
Zhang, Zhijun,Li, Wentao,Liu, Jiansheng,Wang, Wentao,Yu, Changhai,Tian, Ye,Nakajima, Kazuhisa,Deng, Aihua,Qi, Rong,Wang, Cheng,Qin, Zhiyong,Fang, Ming,Liu, Jiaqi,Xia, Changquan,Li, Ruxin,Xu, Zhizhan American Institute of Physics 2016 Physics of plasmas Vol.23 No.5