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Yaochen Zheng Jian Liu Yan Guo Qian Zhang Xuan Gao Zhengguo Gao Tao He Qingfu Ban 《Journal of polymer science. Part A, Polymer chemistry》2020,58(12):1664-1674
Cationic compounds often serve as antibacterial materials for a wide range of applications. However, the relationship of topology−antibacterial activity has been rarely revealed. Herein, three cationic polythioethers (CPTEs) with hyperbranched topologies are well designed and facilely synthesized via an all-click chemistry strategy (including thiol-ene and epoxy-amine additions). These as-prepared CPTEs were found to exhibited outstanding antibacterial activity against Escherichia coli and Staphylococcus aureus with minimum inhibitory concentrations against E. coli of 7.3, 14.6, and 14.6 μg ml−1, and against S. aureus of 14.6, 29.2, and 29.2 μg ml−1, respectively. The antibacterial activity is coincident with their degree of branching (DB, their DB values of 0.81, 0.48, and 0.27), which is mainly attributed to the inherent three-dimensional structure. The present strategy reveals the relationship of polymer topology and antibacterial activity, providing a novel possibility for designing and/or synthesis of high-efficiency antibacterial agents. 相似文献
994.
Li Mengya Yan Pengfei Liu Jie Pei Ying Zheng Xuejing Tang Keyong Wang Fang 《Cellulose (London, England)》2022,29(3):1609-1621
Cellulose - One-step acid hydrolysis was successfully employed to prepare carboxylated cellulose nanofibrils (CCNFs) from pomelo peel waste with the mixture of hydrochloric acid and citric acid... 相似文献
995.
Huiye Zhong Wei-Shang Lo Tiantian Man Benjamin P. Williams Dan Li Dr. Sheng-Yu Chen Prof. Dr. Hao Pei Prof. Dr. Li Li Prof. Dr. Chia-Kuang Tsung 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(57):12931-12935
DNAzymes are a promising class of bioinspired catalyst; however, their structural instability limits their potential. Herein, a method to stabilize DNAzymes by encapsulating them in a metal–organic framework (MOF) host is reported. This biomimetic mineralization process makes DNAzymes active under a wider range of conditions. The concept is demonstrated by encapsulating hemin-G-quadruplex (Hemin-G4) into zeolitic imidazolate framework-90 (ZIF-90), which indeed increases the DNAzyme's structural stability. The stabilized DNAzymes show activities in the presence of Exonuclease I, organic solvents, or high temperature. Owing to its elevated stability and heterogeneous nature, it is possible to perform catalysis under continuous-flow conditions, and the DNAzyme can be reactivated in situ by introducing K+. Moreover, it is found that the encapsulated DNAzyme maintains its high enantiomer selectivity, demonstrated by the sulfoxidation of thioanisole to (S)-methyl phenyl sulfoxide. This concept of stabilizing DNAzymes expands their potential application in chemical industry. 相似文献
996.
Xuan B. Nguyen Yuji Nakano Nisharnthi M. Duggan Lydia Scott Martin Breugst David W. Lupton 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(33):11607-11614
Direct polarity inversion of conjugate acceptors provides a valuable entry to homoenolates. N‐heterocyclic carbene (NHC) catalyzed reactions, in which β‐unsubstituted conjugate acceptors undergo homoenolate formation and C?C bond formation twice, have been developed. Specifically, the all‐carbon (5+1) annulations give a range of mono‐ and bicyclic cyclohexanones (31 examples). In the first family of annulations, β‐unsubstituted acrylates tethered to a divinyl ketone undergo cycloisomerization, providing hexahydroindenes and tetralins. In the second, partially untethered substrates undergo an intermolecular (5+1) annulation involving dimerization followed by cycloisomerization. While enantioselectivity was not possible with the former, the latter proved viable, allowing cyclohexanones to be produced with high levels of enantiopurity (most >95:5 e.r.) and exclusive diastereoselectivity (>20:1 d.r.). Derivatizations and mechanistic studies are also reported. 相似文献
997.
Journal of Heuristics - In this paper, we present a method to identify forum posts expressing user intentions in online discussion forums. The results of this task, for example buying intentions,... 相似文献
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Dr. Xiao‐Ye Wang Dr. Jie‐Yu Wang Prof. Jian Pei 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(9):3528-3539
Replacement of C?C unit with its isoelectronic B?N unit in aromatics provides a new class of molecules with appealing properties, which have attracted great attention recently. In this Concept, we focus on BN‐substituted polycyclic aromatics with fused structures, and review their synthesis, photophysical, and redox properties, as well as their applications in organic electronics. We also present challenging synthetic targets, large BN‐ substituted polycyclic aromatics, such as regioregular BN heterosuperbenzenes, which can be viewed as BN‐doped nanographenes. Finally, we propose an atomically precise bottom‐up synthesis of structurally well‐defined BN‐doped graphenes. 相似文献
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