EUROPEAN POLYMER JOURNAL
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2019
·
IF 3.621
Muhammad Atif,Chaoshi Chen,Muhammad Irfan,Fatima Mumtaz,Kang He,Miao Zhang,Lijuan Chen,Yanmei Wang
In this work, poly[(2-methyl-2-oxazoline)-random-glycidyl methacrylate] (PMOXA-r-GMA) and poly(4-vinyl pyridine)-block-poly(glycidyl methacrylate) (P4VP-b-PGMA) were synthesized by cationic ring opening polymerization (CROP) of 2-methyl-2-oxazoline (MOXA) and reversible addition-fragmentation chain transfer (RAFT) polymerization of 4-vinyl pyridine (4VP) followed by their random and block copolymerization with glycidyl methacrylate (GMA), respectively. Then poly(2-methyl-2-oxazoline)/poly(4-vinyl pyridine) (PMOXA/P4VP) based binary polymer brushes on silicon/glass substrate were fabricated using spin coating of the mixture of PMOXA-r-GMA and P4VP-b-PGMA copolymer solution followed by annealing process at 110 °C. Afterwards, these polymer brushes were characterized via water contact angle (WCA), X-ray photoelectron spectroscopy (XPS), variable angle spectroscopic ellipsometry (VASE), and atomic force microscopy (AFM) techniques. The results showed that the surface composition on the substrate surface could be adjusted by tuning the composition of the mixture of polymer solution used for the preparation of mixed brushes. Moreover, it also showed the swelling and de-swelling of mixed polymer brushes in a systematic way between two specific points during varying the pH of the surrounding medium from 2 to 10. Finally, the tunable behavior of PMOXA/P4VP based mixed brushes against bovine serum albumin (BSA) adsorption/desorption was investigated by fluorescein isothiocyanate-labelled BSA (FITC-BSA) assay and ellipsometry measurements. The results indicated that by changing the pH value from 2 to 10, the PMOXA/P4VP based mixed brushes could adsorb and desorb protein from very low to high amount depending upon the composition of PMOXA-r-GMA and P4VP-b-PGMA in preparing solution used for the PMOXA/P4VP based coatings, and ~89% of the adsorbed protein could be desorbed under the selected conditions.
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Asian Journal of Organic Chemistry
·
2018
·Vol. 7
·期 12
·2527-2533
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IF 2.496
Wei-Ze Li,Zhong-Xia Wang
Graphical Reaction of quinoline N -oxides and pyridine N -oxides with arylzinc reagents under transition-metal-free conditions was studied. The reaction was carried out in toluene (for quinoline N -oxides) or THF (for pyridine N -oxides) at 100 °C and required 2 equiv. of arylzinc loadings and the presence of 2.5 equiv. of TFAA, affording 2-arylquinolines and 2-arylpyridines, respectively, in 24% to 95% yields. Reaction of quinoline N -oxides and pyridine N -oxides with arylzinc reagents under transition-metal-free conditions was studied. The reaction was carried out in toluene (for quinoline N -oxides) or THF (for pyridine N -oxides) at 100 °C and required 2 equiv. of arylzinc loadings and the presence of 2.5 equiv. of TFAA, affording 2-arylquinolines and 2-arylpyridines, respectively, in 24% to 95% yields. Functional groups OMe, F, Cl, Br, CF 3 , C(O)NH 2 , COOR and NO 2 were tolerated. Mechanistic studies showed that the reaction of quinoline N -oxides proceeded via a 2-arylquinolin-1(2 H )-olate intermediate, and the reaction of pyridine N -oxides via a 5-arylpenta-2,4-dienal oxime intermediate.
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Journal of Materials Chemistry B
·
2015
·Vol. 3
·期 27
·5615-5628
·
IF 4.726
Chong Zhang,Songtao Liu,Lin Tan,Haikun Zhu,Yanmei Wang
Development of surfaces with antifouling properties is of great interest in biomedical applications. In this paper, the research was aimed at rapid preparation of poly(2-methyl-2-oxazoline)-based antifouling coating. We designed and synthesized a set of well-defined multiarm star copolymers hyperbranched poly(ethylenimine)-graft-poly(2-methyl-2-oxazoline) (PEI-g-PMOXA) with different PMOXA grafting ratios and chain lengths. The cytotoxicity of the polymer was tested and the PMOXA-based films were successfully deposited rapidly onto substrates via a simple one-step dopamine-assisted codeposition method. The effect of polymer architecture (linear PMOXA with different molecular weights, star PMOXA with different PMOXA grafting ratios and arm lengths) on deposited films with respect to their deposition kinetics, surface composition, wettability, morphology, cytotoxicity, and antifouling properties was investigated systematically. The antifouling properties of PMOXA-based films were found to be dependent on the surface PMOXA chain densities, which were controlled by the PMOXA grafting ratios and chain lengths. Moreover, the star PMOXA structures gave the surfaces with higher PMOXA chain densities and enhanced antifouling properties compared to the linear ones. Among the star copolymers, PEI-g(70)-PMOXA(5K)/polydopamine and PEI-g(70)-PMOXA(7K)/polydopamine deposited films showed the highest resistance to protein adsorption (96–99% relative to the bare gold surface) and cell attachment (97–99% relative to the bare glass surface), as well as complete inhibition against platelet adhesion. At last, the stability test results showed that the PMOXA-based film exhibited superior stability in long-term applications than the poly(ethylene glycol)-based film.
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MOLECULAR NEUROBIOLOGY
·
2025
·
IF 4.3
Yan Qian,Li Xiao-Jun,Wang Qi-Qi,Jia Wei,Wang Shu-Ling
Approaches of promoting a neural milieu permissive for plasticity and resilience against neuronal injury are important strategies for the treatment of a range of neurological disorders. Fibroblast growth factor 21 (FGF21) which is known for its role as a potent regulator of glucose and energy metabolism has also proved to be neuroprotective against various mental diseases. However, the underlying molecular mechanisms remain elusive. Here, we report a study of the neuroprotective effects of FGF21 by promoting 5-HT 1A R-FGFR1 heteroreceptor formation and triggering MEK 1/2 -ERK 1/2 signaling pathway in normal or abnormal neurological conditions. First, the in vitro cellular experiments demonstrated that FGF21 exerted a protective effect against glutamate-induced cytotoxicity and promoted cell differentiation and growth. Then, in wild-type and FGF21 −/− mice, exogenous FGF21 promoted FGFR1-5-HT 1A R heteromers formation in the CA3 and dentate gyrus region of the hippocampus and activated MEK 1/2 -ERK 1/2 signaling. Coordinately, FGF21 exerted similar influences in the hippocampi of IBA-induced neurological injury mice or combined stress-exposed mice. Besides, FGF21 treatment activated the phosphorylation of FGFR1 and elevated the expression of synaptophysin in these mice with neurological injury or combined stress exposure. These results illustrated that FGF21 alleviated neurological impairment through FGFR1-5-HT 1A R heteromer and ERK 1/2 signal activation and suggested that the regulation of FGFR1-5-HT 1A R heteromers and MEK 1/2 /ERK 1/2 pathway may play a key role in mediating the neuroprotective effects of FGF21 against various neurodegeneration conditions.
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Chemistry-An Asian Journal
·
2024
·
IF 3.5
Xinxin Dai,Zhen Tang,Xinyuan Yan,Shiyi Tao,Shanshan Wang,Yi Liu,Jiafeng Cao,Xiaolong Deng,Xin Bo
The exploring and developing non-precious transition metal-based catalysts for practical water electrolysis with the low cost, high efficiency and easy macroscopic preparation was still a challenge. Herein, Ni 3 S 2 /Ni(OH) 2 heterojunction with different sulfuration time was proposed and hydrothermally synthesized using a simple two-step approach, which served as a bifunctional electrocatalyst for water splitting in alkaline solution at industrial temperature. Among these catalysts, Ni 3 S 2 /Ni(OH) 2 -5h displayed the smallest overpotentials (237 mV@100 mA cm −2 and 360 mV@100 mA cm −2 ) for OER and HER at room temperature, along with low Tafel slopes of 62.0 mV dec −1 and 80.8 mV dec −1 respectively. Furthermore, working at high temperature Ni 3 S 2 /Ni(OH) 2 -5h exhibited even lower overpotential of 82 mV@100 mA cm −2 at 70 °C for OER and 325 mV@100 mA cm −2 at 60 °C for HER. The excellent performance was ascribed to the heterojunction accelerating the charge transfer, hierarchical interconnected structure promoting the mass transfer and the synergistic effect between the components of Ni 3 S 2 and Ni(OH) 2 . This work could provide a promising route for promoting the electrocatalytic performance of Ni-based catalyst with a simple sulfuration method for industrial water splitting, which could expand to other non-noble metal-based materials for enhancing the electrocatalytic activities.
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IUBMB LIFE
·
2024
·
IF 3.7
Yexuan Lin,Na Sun,Dengyuan Liu,Xinmeng Yang,Yixin Dong,Chengyu Jiang
In 2020, the number of deaths caused by lung cancer worldwide reached 1,796,144, making it the leading cause of cancer-related deaths. Cyclooxygenase-2/prostaglandin endoperoxide synthase 2 ( COX-2/PTGS2 ) is overexpressed in lung cancer, which promotes tumor proliferation, invasion, angiogenesis, and resistance to apoptosis. Here, we report that the oligonucleotide drug HQi-sRNA-2 from Traditional Chinese Medicine Huangqin targeting COX-2/PTGS2 significantly inhibited proliferation, migration, and invasion and induced apoptosis in the human lung cancer cell line NCI-H460. Oral delivery of HQi-sRNA-2 bencaosomes prolonged survival, reduced tumor burden, and maintained weight in a spontaneous mouse lung cancer model. Compared with paclitaxel, HQi-sRNA-2 may be less toxic and have approximately equal efficacy in reducing tumor burden. Our previous studies reported that herbal small RNAs (sRNAs) are functional medical components. Our data suggest that sphingosine (d18:1)-HQi-sRNA-2 bencaosomes, targeting COX-2/PTGS2 and downregulating the PI3K and AKT signaling pathways, may provide novel therapeutics for lung cancer.
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BIOORGANIC CHEMISTRY
·
2024
·
IF 4.5
Ting Wang,Xiufeng Liao,Xiaodi Zhao,Kai Chen,Yangzhonghui Chen,Hui Wen,Dali Yin,Yuchen Wang,Bin Lin,Sen Zhang,Huaqing Cui
Mimicking the transition state of tryptophan (Trp) and O 2 in the enzymatic reaction is an effective approach to design indoleamine 2, 3-dioxygenase 1 (IDO1) inhibitors. In this study, we firstly assembled a small library of 2-substituted benzo-fused five membered heterocycles and found 2-sulfinyl-benzoxazoles with interesting IDO1 inhibitory activities. Next the inhibitory activity toward IDO1 was gradually improved. Several benzoxazoles showed potent IDO1 inhibitory activity with IC 50 of 82–91 nM, and exhibited selectivity between IDO1 and tryptophan 2, 3-dioxygenase (TDO2). Enzyme binding studies showed that benzoxazoles are reversible type II IDO1 inhibitors, and modeling studies suggested that the oxygen atom of the sulfoxide in benzoxazoles interacts with the iron atom of the heme group, which mimics the transition state of Fe-O-O-Trp complex. Especially, 10b can effectively inhibit the NO production in lipopolysaccharides (LPS) stimulated RAW264.7 cells, and it also shows good anti-inflammation effect on mice acute inflammation model of croton oil induced ear edema.
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JOURNAL OF ELECTROANALYTICAL CHEMISTRY
·
2021
·
IF 4.464
Zhipeng Li,Shuo Wu,Guizheng Zou
Discriminating the electrochemiluminescence (ECL) of differed luminophores is crucial for ECL multiplexing. However, because of the limited potential window for ECL assay and the overlapped triggering-potential-range between different luminophores, the potential-resolved ECL multiplexing with good resolutions ( R s ) is still a great challenge. Herein, a single anodic ECL from two luminophores in the aqueous solution was discriminated completely (baseline separation, R s ≥ 1.5) in a potential-resolved way with the water-soluble CuInS 2 @ZnS ( [email protected] ) nanocrystals (NCs) and [Ru(bpy) 2 (dcbpy)] 2+ as luminophores and N 2 H 4 as the co-reactant. N 2 H 4 could be electrochemically oxidized to reducing radicals and then reacted with the electrochemically oxidized [email protected] NCs and [Ru(bpy) 2 (dcbpy)] 2+ in sequence to produce co-reactant ECL. The potential-resolved ECL of [email protected] NCs/N 2 H 4 and [Ru(bpy) 2 (dcbpy)] 2+ /N 2 H 4 could be well defined and distinguished from each other upon potential scanning ( R s = 2.60) and utilized for simultaneously determining human prostate specific antigen and carcinoma antigen 125 at the pathological cut-off concentration ( R s = 1.56).
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POLYMER TESTING
·
2020
·
IF 3.275
Zhipeng He,Huichao Liu,Guang Yang,Chi Jiang,Muwei Ji,Jiali Yu,Mingliang Wang,Caizhen Zhu,Jian Xu
Cyclization reaction of poly(acrylonitrile-co-2-acrylamido-2-methylpropane sulfonic acid) [P(AN-co-AMPS)] copolymer during thermal oxidative stabilization (TOS) process was investigated by FTIR and two dimensional (2D) correlation analysis technique. The results showed the mechanism of cyclization reaction at different temperatures were varying. At 200 °C, the cyclization reactions generated by autocatalytic cyclization mechanism. While at higher temperatures, the cyclization reactions took place through ionic cyclization mechanism and free radical cyclization mechanism. The AMPS comonomer could reduce the heat release of cyclization reactions and improve the stability at 200 and 230 °C. At higher temperatures, the cyclization reactions were facilitated rapidly. However, the oxidation and degradation reactions were also intense, which will cause the molecular chain to break and defects in the final carbon fibers (CFs). This research has theoretical guiding significance for the optimization of heat treatment conditions for PAN copolymers used as CFs.
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CATALYSIS COMMUNICATIONS
·
2018
·
IF 3.463
Xiaoqiang Gao,Fang Zhang,Yi Yu,Yonghui Dou,Li Xu,Guoji Liu
Mo-modified V 2 O 5 /TiO 2 catalysts were prepared by wetness impregnation method and investigated for the selective oxidation of 2-methylnaphthalene to 2-naphthaldehyde. The catalysts were characterized by XRD, BET, XPS, and Raman to investigate the promotional effect of Mo on catalyst structure, surface property, and catalytic performance. The introduction of molybdenum decreases the amount of KVO 3 phase and enhances the dispersion of the vanadium phase. XPS and Raman results indicate that Mo prevents Sn and K to interact with V species and bonds with Ti or V through bridge oxygen. V1Mo1 sample demonstrates a remarkable improvement in conversion and selectivity compared with others.
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JOURNAL OF HETEROCYCLIC CHEMISTRY
·
2024
·
IF 2
Guofang Jiang,Can Zhang,Xiaohong Xing,Jinbo Ouyang,Hong Yang,Zongbo Xie,Zhanggao Le
A novel and highly efficient method for the synthesis of 1-(4-hydroxybutyl)-2-benzoyl indoles from 2-pyrrolidine benzaldehyde and α -bromoacetophenone in a choline chloride (ChCl)/ZnCl 2 eutectic mixture was developed. This method, which does not require any catalyst, additive, or alkali, is useful for realizing tandem cyclization reactions. Several indoles were produced after cyclization and ring opening processes. Not all the compounds obtained are reported in the literature. This synthetic strategy proves that deep eutectic solvents can replace catalysts and organic solvents. Consequently, this is an environmentally friendly strategy that has significant potential in the development of green and sustainable chemistry.
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Inorganic Chemistry Frontiers
·
2019
·Vol. 6
·期 11
·3125-3132
·
IF 5.934
Qian Wang,Lei Wang,Xiaoyu Zhao,Ling Huang,Daojiang Gao,Jian Bi,Xin Wang,Guohong Zou
By introducing Sb3+ cations with a stereochemically active lone pair in the sulfate system, two antimony fluoride sulfates with the same stoichiometric ratio, namely, K2SO4·(SbF3)2 and Rb2SO4·(SbF3)2, were successfully synthesized via mild hydrothermal reactions. The cooperative effects of the alkali metal cation size and lone pairs resulted in a different symmetry for these two title compounds. The compound K2SO4·(SbF3)2 crystallized in a centrosymmetric (CS) space group of P21/c, while Rb2SO4·(SbF3)2 crystallized in the noncentrosymmetric (NCS) space group of P21. Though both of these two compounds consisted of similar structural building units, [SbF3O2]4− tetragonal pyramid complexes and [SO4]2− tetrahedra, they displayed discrepant helix columns in the crystal structure due to the different steric hindrance forces produced by the alkali metal cations. The alkali metal cations K+/Rb+ provided a charge balance and connected the different helix columns to form the three-dimensional framework. The detailed characterizations revealed that Rb2SO4·(SbF3)2 was a potential ultraviolet nonlinear optical material. In addition, theoretical calculations were performed.
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