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91.
Nitrogen‐Doped Ordered Mesoporous Carbon Supported Bimetallic PtCo Nanoparticles for Upgrading of Biophenolics 下载免费PDF全文
Dr. Guang‐Hui Wang Dr. Zhengwen Cao Dr. Dong Gu Norbert Pfänder Ann‐Christin Swertz Bernd Spliethoff Hans‐Josef Bongard Dr. Claudia Weidenthaler Dr. Wolfgang Schmidt Dr. Roberto Rinaldi Prof. Dr. Ferdi Schüth 《Angewandte Chemie (International ed. in English)》2016,55(31):8850-8855
Hydrodeoxygenation (HDO) is an attractive route for the upgrading of bio‐oils produced from lignocellulose. Current catalysts require harsh conditions to effect HDO, decreasing the process efficiency in terms of energy and carbon balance. Herein we report a novel and facile method for synthesizing bimetallic PtCo nanoparticle catalysts (ca. 1.5 nm) highly dispersed in the framework of nitrogen‐doped ordered mesoporous carbon (NOMC) for this reaction. We demonstrate that NOMC with either 2D hexagonal (p6m) or 3D cubic (Im m) structure can be easily synthesized by simply adjusting the polymerization temperature. We also demonstrate that PtCo/NOMC (metal loading: Pt 9.90 wt %; Co 3.31 wt %) is a highly effective catalyst for HDO of phenolic compounds and “real‐world” biomass‐derived phenolic streams. In the presence of PtCo/NOMC, full deoxygenation of phenolic compounds and a biomass‐derived phenolic stream is achieved under conditions of low severity. 相似文献
92.
The interaction between HⅣ-1 DNA and five cyclic peptides (CP1-CP5) was investigated using electrospray ionization mass spectrometry (ESI-MS). It revealed that CP1 [c(Ala-Tyr-Leu-Ala-Gly)] and CP4 [c(Pro-D-Tyr-Leu-D-Ala-Gly)] have the higher binding affinity with the duplex DNA among the five cyclic peptides. 相似文献
93.
Jian-Chang He Sheng-Hua Gu Di Liu Qing Zhang En-Fu Feng Yuan-Yuan Gong Gui-Li Xu 《Chromatographia》2008,68(11-12):1009-1012
A sensitive and reproducible liquid chromatographic method with UV detection was described for the determination of helicidum in beagle dog plasma. Sample preparation was accomplished through protein precipitation with 15% perchloric acid and chromatographic separation was performed on a reversed phase C18 column at 30 °C. Mobile phase consisted of a mixture of acetonitrile–water at a flow rate of 1.0 mL min?1. Wavelength was set at 270 nm. The method was applied to a pharmacokinetic study of two formulations of helicidum. No statistical difference in the t 1/2 (AUC0–5, AUC0–∞) between the two formulations were observed. The t max of helicidum ODTs is significantly shorter than that of conventional tablets (0.84 h vs. 1.33 h, P< 0.05). 相似文献
94.
Dr. Yunxiang Li Dr. Yan Guo Dr. Deyan Luan Prof. Xiaojun Gu Prof. Xiong Wen Lou 《Angewandte Chemie (International ed. in English)》2023,62(44):e202310847
Developing highly efficient catalytic sites for O2 reduction to H2O2, while ensuring the fast injection of energetic electrons into these sites, is crucial for artificial H2O2 photosynthesis but remains challenging. Herein, we report a strongly coupled hybrid photocatalyst comprising polymeric carbon nitride (CN) and a two-dimensional conductive Zn-containing metal–organic framework (Zn-MOF) (denoted as CN/Zn-MOF(lc)/400; lc, low crystallinity; 400, annealing temperature in °C), in which the catalytic capability of Zn-MOF(lc) for H2O2 production is unlocked by the annealing-induced effects. As revealed by experimental and theoretical calculation results, the Zn sites coordinated to four O (Zn-O4) in Zn-MOF(lc) are thermally activated to a relatively electron-rich state due to the annealing-induced local structure shrinkage, which favors the formation of a key *OOH intermediate of 2e− O2 reduction on these sites. Moreover, the annealing treatment facilitates the photoelectron migration from the CN photocatalyst to the Zn-MOF(lc) catalytic unit. As a result, the optimized catalyst exhibits dramatically enhanced H2O2 production activity and excellent stability under visible light irradiation. 相似文献
95.
Si-Yong Yin Qiansujia Zhou Dr. Chen-Xu Liu Prof. Dr. Qing Gu Prof. Dr. Shu-Li You 《Angewandte Chemie (International ed. in English)》2023,62(37):e202305067
Enantioselective synthesis of N−N biaryl atropisomers is an emerging area but remains underexplored. The development of efficient synthesis of N−N biaryl atropisomers is in great demand. Herein, the construction of N−N biaryl atropisomers through iridium-catalyzed asymmetric C−H alkylation is reported for the first time. In the presence of readily available Ir precursor and Xyl-BINAP, a variety of axially chiral molecules based on indole-pyrrole skeleton were obtained in good yields (up to 98 %) with excellent enantioselectivity (up to 99 % ee). In addition, N−N bispyrrole atropisomers could also be synthesized in excellent yields and enantioselectivity. This method features perfect atom economy, wide substrate scope, and multifunctionalized products allowing diverse transformations. 相似文献
96.
Chang Liu Yunci Zhang Shanshan Tang Yi Wang Jing Tian Dongyu Gu Yi Yang 《Journal of separation science》2023,46(10):2200958
Robinia pseudoacacia flowers have attracted much attention because of numerous bioactivities. In this study, its extract showed the potential scavenging ability for 2,2′-azinobis-(3-ethylbenzthiazoline-6-sulphonate) and 1,1-diphenyl-2-picrylhydrazyl free radicals. Under the guidance of antioxidant activity, the antioxidant extract was enriched by liquid-liquid extraction. The partition coefficients of the two main components in antioxidant extracts differed greatly, so in this study, elution-extrusion counter-current chromatography with the solvent system of n-hexane-ethyl acetate-methanol-water (2.5:5:2.5:5, v/v) was used to enhance the separation efficiency, and the two main components were successfully obtained. Among them, kaempferol showed strong antioxidant activity, which can be responsible for the activity of the extract. In order to deeply understand the antioxidant mechanism of kaempferol, the thermodynamics, frontier molecular orbital, and kinetics of scavenging free radicals were investigated by density functional theory. The results showed that 4′-OH in kaempferol was the most active group, which can scavenge free radicals by hydrogen atom transfer in non-polar solvents and activate 3-OH to generate double hydrogen atom transfer in the gas phase. But in polar solvents, it was more inclined to clear radicals through single electron transfer and proton transfer. The kinetic result showed that kaempferol needed 9.17 kcal/mol of activation energy to scavenge free radicals. 相似文献
97.
Prof. Xiaona Li Yang Xu Prof. Changtai Zhao Duojie Wu Dr. Limin Wang Matthew Zheng Xu Han Dr. Simeng Zhang Junyi Yue Prof. Biwei Xiao Dr. Wei Xiao Dr. Ligen Wang Prof. Tao Mei Prof. Meng Gu Prof. Jianwen Liang Prof. Xueliang Sun 《Angewandte Chemie (International ed. in English)》2023,62(48):e202306433
As exciting candidates for next-generation energy storage, all-solid-state lithium batteries (ASSLBs) are highly dependent on advanced solid-state electrolytes (SSEs). Here, using cost-effective LaCl3 and CeCl3 lattice (UCl3-type structure) as the host and further combined with a multiple-cation mixed strategy, we report a series of UCl3-type SSEs with high room-temperature ionic conductivities over 10−3 S cm−1 and good compatibility with high-voltage oxide cathodes. The intrinsic large-size hexagonal one-dimensional channels and highly disordered amorphous phase induced by multi-metal cation species are believed to trigger fast multiple ionic conductions of Li+, Na+, K+, Cu+, and Ag+. The UCl3-type SSEs enable a stable prototype ASSLB capable of over 3000 cycles and high reversibility at −30 °C. Further exploration of the brand-new multiple-cation mixed chlorides is likely to lead to the development of advanced halide SSEs suitable for ASSLBs with high energy density. 相似文献
98.
Huansong Jing Xuyang Sun Mengqi Li Jingna Peng Xiaoying Gu Jiajun Xiong 《Molecules (Basel, Switzerland)》2022,27(8)
Antler growth depends on the proliferation and differentiation of mesenchymal stem cells (MSCs), and this process may be adversely affected by oxidative stress. Melatonin (MLT) has antioxidant functions, but its role in Cervidae remains largely unknown. In this article, flow cytometry, reactive oxygen species (ROS) identification, qPCR, and other methods were used to investigate the protective mechanism of MLT in H2O2-induced oxidative stress of antler MSCs. The results showed that MLT significantly increases cell viability by relieving the oxidative stress of antler MSCs. MLT inhibits cell apoptosis by protecting mitochondrial function. We blocked the melatonin receptor with luzindole (Luz) and found that the receptor blockade significantly increases H2O2-induced hyperoxide levels and causes significant inhibition of mitochondrial function. MLT treatment activates the nuclear factor E2-related factor 2 (Nrf2) antioxidant signaling pathway, up-regulates the expression of NAD(P)H quinone oxidoreductase 1 (NQO1) and other genes and it could inhibit apoptosis. In contrast, the melatonin receptor blockade down-regulates the expression of Nrf2 pathway-related genes, but significantly up-regulates the expression of apoptotic genes. It was indicated that MLT activates the Nrf2 pathway through the melatonin receptor and alleviates H2O2-induced oxidative stress and apoptosis in antler MSCs. This study provides a theoretical basis for further studying the oxidative stress and antioxidant process of antler MSCs and, thereby, increasing antler yields. 相似文献
99.
In order to create a functionalized biodegradable polymer for vascular tissue engineering application,poly(DL- lactide-co-RS-β-malic acid)(PDLLMAc)was synthesized.PDLLMAc was obtained after hydrogenolysis of poly(DL- lactide-co-RS-β-benzyl malolactonate)(PDLLMA),which was from the ring-opening polymerization of DL-lactide(DLLA) and RS-β-benzyl malolactonate(MA)using stannous octoate as catalyst.The copolymers were characterized by ~1H-NMR, FTIR,GPC and DSC.The tensile strength and water uptake of the cop... 相似文献
100.
NOVEL pH-SENSITIVE DRUG DELIVERY SYSTEM BASED ON NATURAL POLYSACCHARIDE FOR DOXORUBICIN RELEASE 总被引:2,自引:0,他引:2
A novel pH-sensitive nanoparticle drug delivery system (DDS) derived fl'om natural polysaccharide pullulan for doxorubicin (DOX) release was prepared.Pullulan was functionalized by successive carboxymethylization and amidation to introduce hydrazide groups.DOX was then grafted onto pullulan backbone through the pH-sensitive hydrazone bond to form a pullulan/DOX conjugate.This conjugate self-assembled to form nano-sized particles in aqueous solution as a result of the hydrophobic interaction of the DOX.Tr... 相似文献