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111.
ABSTRACTHerein, we develop a switchable peptide-equipped protein/cucurbit[7]uril (CB[7]) supramolecular assembly as novel targeted drug vector. Specifically, bovine serum albumin (BSA) is used to interact with CB[7], serving as the core of drug vector. Then, a peptide shield layer is formed on the surface of BSA/CB[7], yielding peptide-equipped supramolecular assembly (Pep@BSA@CB[7]). The equipped peptide shield layer is composed of switchable peptide probes consisting of a polycationic cell-penetrating peptide (CPP) motif, a polyanionic motif and a linking motif, and therefore provides a variety of desirable properties. First, the CPP motif displays excellent cell penetration ability and can facilitate internalisation of the drug vector. Secondly, the polyanionic motif performs intramolecular electrostatic interaction with CPP motif and thereby can reduce non-targeted delivery towards normal cells. Thirdly, the linking motif can be specifically cleaved by matrix metalloproteinases 2 that is up-regulated in tumour microenvironment, thus enabling precise cancer-targeting. As a consequent, Pep@BSA@CB[7] can serve as a promising drug vector that exhibits superior targeting ability and high uptake efficiency towards cancer cells, which may be of great potential in cancer-targeted treatment. 相似文献
112.
A detailed quantum chemical study is performed on the mechanism of ClOO + NO reaction at the B3LYP/6-311+G (2d) level of theory
combined with CCSD (T) single point energy calculation. The possible product channels for the reaction are obtained and discussed
on the basis of the singlet [ClNO3] potential energy surface. The calculation indicates that the dominant product for the title reaction is ClO + NO2 by the direct dissociation of the initial adduct, and the formation of the other products is much less likely since they
are unfavorable kinetically. A comparison is also made between the title reaction and the analogous reaction of FO2 + NO to gain a deeper insight into the mechanism of the XO2 + NO reactions. 相似文献
113.
Hongyun Zhang Wen Li Xiaokai Zhang Fahong Miao Taohai Li Haihua Liu 《Surface and interface analysis : SIA》2013,45(5):919-929
A selection of suitable microstructures is critical to fabrication and properties of superhydrophobic surfaces (SHS). In this study, we introduce a three‐dimensional droplet model to thermodynamically analyze the superhydrophobic properties for the purpose of determining the second step of a two‐step microstructure suitable for the SHS based on the common models within the reach of the existing macro‐machining technology. It is found that a sinusoidal microstructure is the most suitable, followed by a cone frustum and a prism in the composite wetting state, as well as the transition from hydrophilic to hydrophobic depends basically on the solid fraction rather than non‐determinative surface microscopic topography. The predictions of the model are found in quite good agreement with the experimental observations. This study will facilitate fabrication of the SHS on how to select the suitable morphology. Copyright © 2012 John Wiley & Sons, Ltd. 相似文献
114.
Jie Miao Weiwei He Lifen Zhang Yi Wang Zhenping Cheng Xiulin Zhu 《Journal of polymer science. Part A, Polymer chemistry》2012,50(11):2194-2200
In this work, living radical polymerizations of a water‐soluble monomer poly(ethylene glycol) monomethyl ether methacylate (PEGMA) in bulk with low‐toxic iron catalyst system, including iron chloride hexahydrate and triphenylphosphine, were carried out successfully. Effect of reaction temperature and catalyst concentration on the polymerization of PEGMA was investigated. The polymerization kinetics showed the features of “living”/controlled radical polymerization. For example, Mn,GPC values of the resultant polymers increased linearly with monomer conversion. A faster polymerization of PEGMA could be obtained in the presence of a reducing agent Fe(0) wire or ascorbic acid. In the case of Fe(0) wire as the reducing agent, a monomer conversion of 80% was obtained in 80 min of reaction time at 90 °C, yielding a water‐soluble poly(PEGMA) with Mn = 65,500 g mol?1 and Mw/Mn = 1.39. The features of “living”/controlled radical polymerization of PEGMA were verified by analysis of chain‐end and chain‐extension experiments. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012 相似文献
115.
116.
Shuyang Liu Miao Tian Dr. Xiubin Bu Dr. Hua Tian Prof. Xiaobo Yang 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(28):7738-7744
Photoactive two-dimensional covalent organic frameworks (2D-COFs) have become promising heterogenous photocatalysts in visible-light-driven organic transformations. Herein, a visible-light-driven selective aerobic oxidation of various small organic molecules by using 2D-COFs as the photocatalyst was developed. In this protocol, due to the remarkable photocatalytic capability of hydrazone-based 2D-COF-1 on molecular oxygen activation, a wide range of amides, quinolones, heterocyclic compounds, and sulfoxides were obtained with high efficiency and excellent functional group tolerance under very mild reaction conditions. Furthermore, benefiting from the inherent advantage of heterogenous photocatalysis, prominent sustainability and easy photocatalyst recyclability, a drug molecule (modafinil) and an oxidized mustard gas simulant (2-chloroethyl ethyl sulfoxide) were selectively and easily obtained in scale-up reactions. Mechanistic investigations were conducted using radical quenching experiments and in situ ESR spectroscopy, all corroborating the proposed role of 2D-COF-1 in photocatalytic cycle. 相似文献
117.
Shan Jiang Yong-peng Zhao Yao Xie Miao Xu Huai-yu Cui Han Wu Yang Liu Qiang Xu Qi Wang 《Applied physics. B, Lasers and optics》2012,109(1):1-7
We demonstrated the lasing of Ne-like Ar 46.9?nm pumped by capillary discharge with the delay time between pre-pulse and main-pulse ranging from 2 to 130???s. Results show that the laser output reduced significantly when the delay time is much longer than 12???s. The temporal evolution of spontaneous radiation emitted from pre-ionized plasma implies that the observed reduction of the laser output is caused by the axial non-uniformity of pre-ionized plasma density and the decrease of pre-ionized plasma density. 相似文献
118.
Complex new materials from simple chemistry: Combining an amino‐substituted polysiloxane and carboxylic acids
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Yong He Hui Zhao Miao Yao Richard G. Weiss 《Journal of polymer science. Part A, Polymer chemistry》2017,55(23):3851-3861
Changes in rheological, adhesive, and swelling properties of quaternary salts, made by adding one of eight mono‐ or six α,ω‐alkanedioic acids (the latter with two to six or nine carbon atoms) to 6‐7PSil (a polysiloxane with 6%–7% of the monomer units contain a 3‐aminopropyl group) have been correlated with the salt structures. The simple acid‐base chemistry initiates drastic changes in the bulk properties of the materials that depend on the amount and type of the added acid. Thus, the quaternized forms of the 6‐7PSil have significantly enhanced viscoelastic and adhesive properties compared to those of the initial polysiloxane, and they can swell selectively liquids based on their polarity. Also, interpenetrating networks have been made in situ by photopolymerization of salts with vinylic carboxylic acids. DFT calculations on model systems consisting of dimethylammonium α,ω‐alkanedioate salts with two to six carbon atoms provide insights into the interactions responsible for the unexpected dependence of the properties of the 6‐7PSil salts on the chain lengths of the diacids. The potential for applying the methodologies described here to systems with other amino‐substituted polymers and other acid types is noted. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2017 , 55, 3851–3861 相似文献
119.
A star edge coloring of a graph is a proper edge coloring such that every connected 2-colored subgraph is a path with at most 3 edges. Deng et al. and Bezegová et al. independently show that the star chromatic index of a tree with maximum degree is at most , which is tight. In this paper, we study the list star edge coloring of -degenerate graphs. Let be the list star chromatic index of : the minimum such that for every -list assignment for the edges, has a star edge coloring from . By introducing a stronger coloring, we show with a very concise proof that the upper bound on the star chromatic index of trees also holds for list star chromatic index of trees, i.e. for any tree with maximum degree . And then by applying some orientation technique we present two upper bounds for list star chromatic index of -degenerate graphs. 相似文献
120.
Dr. Longyu Li Qianming Lin Miao Tang Dr. Andrew J. E. Duncan Prof. Dr. Chenfeng Ke 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(46):10768-10781
The rapid development of additive manufacturing techniques, also known as three-dimensional (3D) printing, is driving innovations in polymer chemistry, materials science, and engineering. Among current 3D printing techniques, direct ink writing (DIW) employs viscoelastic materials as inks, which are capable of constructing sophisticated 3D architectures at ambient conditions. In this perspective, polymer designs that meet the rheological requirements for direct ink writing are outlined and successful examples are summarized, which include the development of polymer micelles, co-assembled hydrogels, supramolecularly cross-linked systems, polymer liquids with microcrystalline domains, and hydrogels with dynamic covalent cross-links. Furthermore, advanced polymer designs that reinforce the mechanical properties of these 3D printing materials, as well as the integration of functional moieties to these materials are discussed to inspire new polymer designs for direct ink writing and broadly 3D printing. 相似文献