APPLIED CATALYSIS A-GENERAL
·
2022
·
IF 5.723
Weilu Wang,Xiangke Zeng,Shan He,Haidong Zhang,Guangming Jiang,Yang He,Yunqi Liu,Fan Dong,Xianming Zhang,Steven L. Suib
A series of Fe-doped alumino-borate catalysts (18 % Fe-PKU-1) with a range of crystalline qualities has been obtained by varying synthesis conditions. Based on Angle-resolved X-ray Photoelectron Spectroscopy, pyridine adsorption infrared spectroscopy, and potentiometric titration, crystalline quality is correlated as volcano trends with the surface composition and electronic structure of Fe-PKU-1, especially for the boron species. Through the systematic change of synthesized conditions, the catalyst with the appropriate crystalline quality shows the highest surface compositions of boron and oxygen vacancies. This leads to strong surface Lewis acidity and results in the high catalytic performance of glycerin ketalization, 97 % conversion and 99 % selectivity in DL-1,2-Isopropylideneglycerol (Solketal).
研究领域:
催化
·
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
npj Materials Degradation
·
2024
·Vol. 8
·期 1
·1-12
·
IF 6.6
Xi Le,Lv Yadong,Feng Jiabao,Huang Yanyan,Huang Yajiang,Yang Qi,Li Guangxian,Kong Miqiu
Due to their excellent mechanical properties and intrinsic flexibility, polyimides (PIs) are promising candidates for optoelectrical applications under harsh conditions such as flexible organic solar cells as well as flexible smart windows, etc. Much progress has been made on their optical transmittance; however, there remain significant concerns about their environmental stability, particularly their UV resistance. Herein, 4 types of colorless polyimides (CPIs) with different molecular structures containing trifluoromethyl, ethers, or fluorenes are carefully designed, and the dependence of their UV resistance on structures is explored systematically. It is found that the introduction of isopropylidene, ethers and fluorenes effectively enhances the UV resistance of CPI and its initial performance (optical transparency, thermal stability, and toughness) simultaneously as a result of the subtle manipulation of the conjugation structures. Specifically, the optimized polyimide film shows decent optical properties ( \({T}_{550{\rm{nm}}}\) ~ 88%, yellowness index ~3.26), and thermal stability ( \({T}_{5 \% }\) ~ 503 °C in N 2 atmosphere, \({T}_{{\rm{g}}}\) ~ 312 °C). Moreover, after high-intensity UV irradiation, CPI not only maintains over 90% of mechanical properties but also retains excellent optical properties ( \({T}_{550{\rm{nm}}}\) ~ 88%) and thermal stability ( \({T}_{5 \% }\) ~ 506 °C). The design strategy paves the way for enhancing the durability of PIs for energy conversion and electronic applications resisting harsh conditions.
研究领域:
材料科学
·
光电子学
·
高分子化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF INTERFERON AND CYTOKINE RESEARCH
·
2019
·Vol. 39
·期 9
·554-563
·
IF 1.774
Yan Yan,Pengchong Wang,Ying Sun,Yalin Dong,Jianfeng Xing
Previously, we reported that 3, 4-oxo-isopropylidene-shikimic acid (ISA) has therapeutic potential in experimental colitis in rats. This study aimed to elucidate the potential mechanisms of ISA on the inflammatory response in rats with 2, 4, 6-trinitrobenzenesulfonic acid-induced colitis. After the induction of colitis, rats were orally administered ISA for 12 days. Then, the expression levels of inflammatory cytokines, cell adhesion molecules, and matrix metalloproteinase (MMP) in the blood and colon tissues, and the protein level of nuclear factor kappa B (NF-κB) p65 in cytoplasm and nucleus of colon tissues were evaluated. As a result, an enhanced inflammatory response was observed in rats with experimental colitis. However, the treatment with ISA significantly ameliorated the inflammatory response, which was manifested as a significant decrease in the levels of tumor necrosis factor (TNF)-α, interleukin (IL)-1β, interferon (IFN)-γ, IL-8, TNF-α mRNA, P-selectin, E-selectin, intercellular cell adhesion molecule-1, MMP9 and MMP9 mRNA in rat blood and colon tissues, respectively, and a significant decrease in the levels of IFN-γ/IL-4, and the NF-κBp65 activity coefficient. Therefore, the therapeutic effect of ISA on experimental colitis may be related to its inhibitory effect on the expression of cytokines, adhesion molecules, and MMP9, which may be involved in the inhibition of the activation and nuclear translocation of NF-κBp65.
研究领域:
药理学
·
免疫学
·
胃肠病学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
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