Polymer Chemistry
·
2019
·Vol. 10
·期 34
·4718-4731
·
IF 4.76
Xian Yang,Junyi Ruan,Chen Ma,Bingjie Hao,Xiaoyu Huang,Guolin Lu,Chun Feng
Self-seeding of living crystallization-driven self-assembly (CDSA) has been considered to be one of the most attractive strategies to fabricate well-defined fiber-like nanostructures with excellent control over their length and composition. To extend the scope of self-seeding of oligo(p-phenylene vinylene) (OPV)-based copolymers, the poly(N-(2-hydroxypropyl) methacrylamide) (PHPMA) segment with proven biocompatibility, synthetic flexibility and well-developed conjugation chemistry, which was synthesized by reversible addition–fragmentation chain transfer (RAFT) polymerization using an azide-containing chain transfer agent, was coupled with the alkyne-terminated OPV block by a copper-catalyzed alkyne–azide cycloaddition reaction. All OPV5-b-PHPMA (OPV5-b-PHPMA36, OPV5-b-PHPMA71 and OPV5-b-PHPMA100, the subscripts represent the number of repeat units of each block) with the same crystallizable core-forming OPV segment but different corona-forming PHPMA blocks of various chain lengths can self-assemble in ethanol to form fiber-like micelles with a length of several micrometers by a direct heating and cooling process. Uniform fiber-like micelles with a length up to ∼1 μm can be easily prepared by temperature-induced self-seeding of OPV5-b-PHPMA71. However, for self-seeding of OPV5-b-PHPMA36, ribbon-like nanostructures with a uniform and controllable length were formed, whereas relatively short fiber-like micelles with broad length distributions were formed under similar conditions for OPV5-b-PHPMA100. These results indicated that the length of the PHPMA segment played an important role in determining the self-seeding behavior of OPV5-b-PHPMA.
研究领域:
高分子化学
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纳米材料科学
·
自组装
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生物相容性材料
·
药物递送系统
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DOI
高影响因子
Green Processing and Synthesis
·
2019
·Vol. 8
·期 1
·568-576
·
IF 1.128
Yingna Cui,Changping Li,Ming Bao
Deep eutectic solvents (DESs) are successfully used as powerful and recyclable catalysts and solvents for the synthesis of 3,4-dihydropyrimidin-2(1 H )-ones/thiones (DHPMs). The acidity of DESs is the main factor that determines catalytic activity. DESs, based on p -toluene sulfonic acid (PTSA) and choline chloride (ChCl), exhibits the highest catalytic activity. ChCl/2PTSA is suitable for a vast variety of aromatic aldehydes with electron-donating and electron-withdrawing groups, different β-diketonates, and urea or thiourea to obtain the corresponding DHPMs. Furthermore, DESs can be recycled easily after synthesis. The reused DESs achieve catalytic efficiency six times without significant changes. This study will provide a new green catalyst and efficient process for the synthesis of DHPMs.
研究领域:
有机化学
·
绿色化学
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DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2023
·
IF 6.7
Xinhui Sun,Yanjie Chen,Mengmeng Ji,Weiya Zhang,Zhizhong Sun,Wenyi Chu,Xin Wang
Developing efficient bimetallic Ni/Zn metal organic frameworks (MOFs) derived Ni 3 ZnC 0.7 alloy catalyst for cyclization reactions is highly anticipated. Bimetallic Ni/Zn- PTA MOFs with flower-like microspheres morphology was synthesized by using a facile hydrothermal method and used as a precursor for preparation of the catalyst. Then, a ZnO supported Ni-Ni 3 ZnC 0.7 incorporated carbon catalyst (Ni-Ni 3 ZnC 0.7 /ZnO-C) was obtained by deriving from the Ni/Zn- PTA MOFs through one-step pyrolysis. The developed Ni-Ni 3 ZnC 0.7 /ZnO-C catalyst was used as a recoverable heterogeneous catalyst for synthesis of 2-arylbenzimidazoles by cyclization reaction of phenylmethanamines and 2-nitroanilines in good yields. Various characterizations (e.g. SEM/EDX, XRD, TEM, FT-IR, XPS and Raman) revealed that the catalyst exhibited good performance for cyclization reaction, which are ascribed to particular hierarchical structure, as well as synergistic effect between Ni and Ni 3 ZnC 0.7 . As a result, the Ni-Ni 3 ZnC 0.7 /ZnO-C catalyst showed excellent stability and activity for the condensation cyclization reaction. This bimetallic MOFs-derived Ni-Ni 3 ZnC 0.7 catalyst opens up a potential way for fabricating other Carbon supported alloy catalysts in heterogeneous catalysis reactions.
研究领域:
材料科学
·
催化化学
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DOI
高影响因子
Journal of Energy Storage
·
2024
·
IF 8.9
Jianguo Duan,Xinshuai Yan,Kun Lei,Jianguo Cheng,Yaxiong Wang,Qingzong Su,Shimin Xu,Jianming Li,Qing Ma
The phase change materials (PCMs) are encapsulated into porous materials for collecting and storing heat energy has been widely used to overcome the intermittency of solar energy utilization. However, due to the inherent big pore structure and surface characteristics, metal porous materials are not ideal for PCM leakage-proof and slow photo-thermal response. To address these issues, A micro/nanostructured graphene-polyvinyl alcohol nanosheets/Cu(OH) 2 nanowire on a three-dimensional Cu foam (CF) to fill with PCM was designed and prepared. In the composite PCM, the polyvinyl alcohol/reduced graphene oxide (PRG) films coated on Cu(OH) 2 @Cu foam (CCF) provided a large number of active sites for the adsorption of modified paraffin wax (PWS). The prepared composite PCM has a stable structure and high thermal conductivity properties, meanwhile, the strong PRG films play a key role in enhancing leakage-proof and stability. The results show that the enthalpy value of PRG-CCF/PWS are 160.25 J·g −1 after 200 thermal cycles; which still maintains excellent cycle thermal reliability. In addition, under the simulated solar irradiation intensity is 120 mW·cm −2 , the heat storage rate and photo-thermal conversion efficiency of PRG-CCF/PWS are 1.37 J·s −1 and 90.25 %, respectively. It shows excellent photo-thermal response and uniform temperature distribution. This work provides an efficient, sustainable and affordable strategy for manufacturing high-performance composite PCM that can efficiently achieve solar energy utilization and energy management.
研究领域:
材料科学
·
能源工程
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DOI
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
·
2018
·
IF 11.698
Tong-Yang Song,Zhao-Xia Dong,Jian-Dong Song,Xiao-Xia Wang,Guan-Qun Xie,Meng-Fei Luo,Ji-Qing Lu
Dehydrochlorination of 1, 1, 2-trichloroethane was performed on SiO 2 supported alkali metal (Na. K, Cs) and transition metal (Mn, Ni, Zn) catalysts. The surface basicity or acidity of the catalyst exerted great influence on catalytic behaviors. The catalysts with higher amount of base or acid sites resulted in higher activity due to more adsorption sites for reactant. The basic catalysts (Cs/SiO 2 and K/SiO 2 ) tended to form vinylidene chloride with a selectivity up to 80 %; the neutral catalysts (Na/SiO 2 and SiO 2 ) tended to form 1, 2-dichloroethene with a selectivity up to about 80 %; the acidic catalysts (Zn/SiO 2 , Mn/SiO 2 and Ni/SiO 2 ) tended to form 1, 2-dichloroethene with a selectivity up to 96 %. Proposed reaction mechanisms included an E1cb mechanism with a carbanion intermediate on the basic catalysts, an E2 concerted mechanism on the neutral catalysts, and an E1 mechanism with a carbonium intermediate on the acidic catalysts.
研究领域:
化学工程
·
催化科学
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DOI
高影响因子
JOURNAL OF MEDICINAL CHEMISTRY
·
2024
·
IF 6.8
Yahong Tan,Jinyue Yang,Min Wang,Qi Peng,Yongqi Li,Lifeng Fu,Mengmeng Zhang,Jiang Wu,Guanya Yang,Christopher John Hipolito,Youming Zhang,Jianxun Qi,Yi Shi,Yizhen Yin
Macrocyclic peptides have garnered significant attention as promising drug candidates. However, they typically face challenges in achieving and enhancing cell permeability for access to intracellular targets. In this study, we focused on the de novo screening of macrocyclic peptide inhibitors against the main protease (Mpro) of SARS-CoV-2 and identified novel noncovalently bound macrocyclic peptides that effectively inhibit proteolytic activity. High-resolution crystal structures further revealed molecular interactions between the macrocyclic peptides and Mpro. Subsequently, a specific macrocyclic peptide lacking cell permeability was further optimized and transformed into a low-toxicity, metabolically stable bicyclic peptide with a cell penetration capacity and therapeutic potential against SARS-CoV-2. The bicyclic peptide was achieved using a novel strategy that involved introducing both a bicyclic structure and a bridging perfluorobiphenyl group. Our study not only provides a lead peptide inhibitor for COVID-19 but also offers valuable insights into achieving cell penetration for macrocyclic peptides through strategic modifications.
研究领域:
药理学
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病毒学
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药物发现
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蛋白质工程
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DOI
高影响因子
CHEMOSPHERE
·
2020
·
IF 5.778
Worku Lakew Kebede,Dong-Hau Kuo,Fekadu Tadesse Bekena,Lalisa Wakjira Duresa
Environmentally toxic organic pollutants, namely methylene blue (MB), neutral red (NR), Rhodamine B (RhB), and methyl orange (MO) dyes contain highly toxic, carcinogenic, non-biodegradable, and colored pigments which cause harm for humans and aquatic organisms even at low concentrations. To detoxify these toxic organic pollutants from the wastewater, the bimetallic solid solution-typed In–Mo(O,S) 2 catalyst with various indium (In) contents were synthesized at low temperature through a simple precipitation method. The morphological, structural, chemical compositions, electrochemical and optical properties of the catalysts were thoroughly characterized. The photodegradation performance of the In–Mo(O,S) 2 catalysts over the cationic, anionic and neutral dyes were studied under visible light irradiation. It has been observed that the photocatalytic activity was enhanced as In was added to the Mo(O,S) 2 catalyst, and In–Mo(O,S) 2 -20 was found to be the best composition to completely degrade four organic dyes. The dye degradation had rate constant values of 9.5 × 10 −2 min −1 , 6.3 × 10 −2 min −1 , 4.4 × 10 −2 min −1 , and 15.7 × 10 −1 min −1 for MB (20 ppm), NR (20 ppm), RhB (10 ppm), and MO (10 ppm) dyes, respectively. The active species for degradation of MB is different from those for RhB and MO. Single phase In–Mo(O,S) 2 -20 capable to degrade four kinds of dyes at a fast rate is a good photocatalyst.
研究领域:
环境科学
·
材料科学
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DOI
高影响因子
CHEMICO-BIOLOGICAL INTERACTIONS
·
2016
·
IF 2.618
Xia Wu,Jian-Cheng Zhu,Yu Zhang,Wei-Min Li,Xiang-Lu Rong,Yi-Fan Feng
Potential impact of lipid research has been increasingly realized both in disease treatment and prevention. An effective metabolomics approach based on ultra-performance liquid chromatography/quadrupole-time-of-flight mass spectrometry (UPLC/Q-TOF-MS) along with multivariate statistic analysis has been applied for investigating the dynamic change of plasma phospholipids compositions in early type 2 diabetic rats after the treatment of an ancient prescription of Chinese Medicine Huang-Qi-San. The exported UPLC/Q-TOF-MS data of plasma samples were subjected to SIMCA-P and processed by bioMark, mixOmics, Rcomdr packages with R software. A clear score plots of plasma sample groups, including normal control group (NC), model group (MC), positive medicine control group (Flu) and Huang-Qi-San group (HQS), were achieved by principal-components analysis (PCA), partial least-squares discriminant analysis (PLS-DA) and orthogonal partial least-squares discriminant analysis (OPLS-DA). Biomarkers were screened out using student T test, principal component regression (PCR), partial least-squares regression (PLS) and important variable method (variable influence on projection, VIP). Structures of metabolites were identified and metabolic pathways were deduced by correlation coefficient. The relationship between compounds was explained by the correlation coefficient diagram, and the metabolic differences between similar compounds were illustrated. Based on KEGG database, the biological significances of identified biomarkers were described. The correlation coefficient was firstly applied to identify the structure and deduce the metabolic pathways of phospholipids metabolites, and the study provided a new methodological cue for further understanding the molecular mechanisms of metabolites in the process of regulating Huang-Qi-San for treating early type 2 diabetes.
研究领域:
代谢组学
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中医药学
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生物信息学
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DOI
高影响因子
JOURNAL OF SOL-GEL SCIENCE AND TECHNOLOGY
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2013
·Vol. 67
·期 3
·442-450
·
IF 1.66
Gong Cheng-Bin,Yang Yu-Zhu,Gao Chao,Tang Qian,Chow Cheuk-Fai,Peng Jing-Dong,Lam Michael Hon-Wah
Abstract
The primary objective of this work is to develop a photo - responsive surface molecularly imprinted polymer (SMIP) for 2,4 - dichlorophenoxyacetic acid (2,4 - D) to overcome the shortcomings of conventional molecularly imprinted polymers. A photo - responsive functional monomer was firstly prepared by covalent connecting azobenzene and 2,4 - D. The photo - responsive SMIP was then prepared on SiO 2 nanoparticles via sol–gel process, and 2,4 - D was removed via hydrolysis in acid. The SMIP shows specific affinity to 2,4 - D and reversible uptake and release of 2,4 - D upon alternate irradiation at 365 and 440 nm, respectively. The favorable binding strength of the imprinted receptor sites in the SMIP for 2,4 - D is found to be 2.51 × 10 4 M −1 . Density of receptor sites in the SMIP material is 10.59 μmol/g SMIP. The SMIP requires a shorter time to reach equilibrium than does the conventional molecularly imprinted polymer. The well - defined core - shell structure was clearly visualized by high resolution transmission electron microscopy. Graphical Abstract
研究领域:
材料科学
·
环境科学
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DOI
高影响因子
ORGANIC PROCESS RESEARCH & DEVELOPMENT
·
2022
·
IF 3.858
Ling He,Wenjie Ye,Youyu Xie,Qinghai Liu,Hualei Wang,Dongzhi Wei
Bioreductions catalyzed by ketoreductases play an important role in the synthesis of chiral alcohols. However, the synthesis of (R)-2-chloro-1-(3,4-difluorophenyl)ethanol (24b), an important chiral intermediate for the synthesis of the anticoagulant ticagrelor, poses significant challenges in terms of high substrate concentration requirements that limit its production. In this study, a novel NADH-dependent, short-chain dehydrogenase, PpKR8, from Paraburkholderia phymatum STM815, exhibited excellent enantioselectivity and high activity for the production of (R)-CFPL (24b) through the reduction of 2-chloro-1-(3,4-difluorophenyl)ethanone (24a). The coexpression of PpKR8 and glucose dehydrogenase from Bacillus subtilis in Escherichia coli allowed up to 300 g/L (1.57 M) CFPO (24a) to be completely converted into 24b with 99.9% enantiomeric excess and a high space–time yield (728 g/(L day)). Substrate specificity assays demonstrated a broad substrate spectrum for PpKR8, which included 35 α/β-ketoesters, aromatic ketones, and heterocyclic ketones. Moreover, three additional optically pure chiral alcohols that are used as important drug intermediates were synthesized at high substrate concentrations (150–330 g/L), demonstrating the excellent industrial potential of PpKR8-mediated bioreductions.
研究领域:
生物化学
·
酶工程
·
制药工业
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DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2021
·
IF 6.707
Jinhua Lai,Feng Cheng,Shuolin Zhou,Sha Wen,Dongwen Guo,Wenguang Zhao,Xianxiang Liu,Dulin Yin
Nitrogen-containing polymer-supported Cu-doped MnO 2 (Cu-MnO 2 @PDVTA) nanowires were prepared and their catalytic performances were evaluated via oxidation of biomass-derived 5-hydroxymethylfurfural (HMF) to 2,5-furandicarboxylic acid (FDCA). The Cu-MnO 2 @PDVTA catalysts were characterized by Fourier-transform infrared spectroscopy, X-ray diffraction, N 2 physical adsorption, transmission electron microscopy, and X-ray photoelectron spectroscopy. Both the Cu 2+ and MnO 2 nanoparticles were found to synergistically promote HMF oxidation to FDCA via 2,5-furandicarbaldehyde and 5-formyl-2-furancarboxylic acid intermediates. The Cu-MnO 2 @PDVTA-3 catalyst demonstrated the highest catalytic activity, providing FDCA with an excellent yield of 96.8% after 12 h at 80 °C. The time course of HMF oxidation revealed that oxidation of the hydroxyl group in HMF was easier than that of the aldehyde group. Cu-MnO 2 @PDVTA-3 could act as a reusable heterogeneous catalyst for HMF oxidation.
研究领域:
化学工程
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材料科学
·
催化反应
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DOI
高影响因子
JOURNAL OF RADIOANALYTICAL AND NUCLEAR CHEMISTRY
·
2024
·
IF 1.5
He Xuexiang,Liao Linyuan,Tang Jing,Chen Lifeng,Lv Lidan,He Dongqiao,Yin Xiangbiao,Li Wenlong,Ning Shunyan,Wei Yuezhou
A silica-supported copolymer loaded with bis (2-ethylhexyl) phosphate was prepared and first investigated for the separation of trace radium from natural 232 Th. Results showed that the adsorbent was prepared successfully with ultrahigh selectivity and ultrafast adsorption kinetics towards thorium, making the separation easy and convenient. The chemical recovery rate to radium reached 96.7%, and the decontamination factor to thorium exceeded 10 5 . Generally, this work demonstrated the feasibility of using this material and method to directly separate 228 Ra and 224 Ra from 232 Th, rendering it significant in the future preparation and application of 212 Pb.
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