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901.
Dr. Qingqing Miao Dr. David C. Yeo Dr. Christian Wiraja Dr. Jianjian Zhang Xiaoyu Ning Prof. Chenjie Xu Prof. Kanyi Pu 《Angewandte Chemie (International ed. in English)》2018,57(5):1256-1260
Early detection of skin diseases is imperative for their effective treatment. However, fluorescence molecular probes that allow this are rare. The first activatable near‐infrared (NIR) fluorescent molecular probe is reported for sensitive imaging of keloid cells, skin cells from abnormal scar fibrous lesions. As keloid cells have high expression levels of fibroblast activation protein‐alpha (FAPα), the probe (FNP1) is designed to have a caged NIR dye and a FAPα‐cleavable peptide substrate linked by a self‐immolative segment. FNP1 can quickly and specifically turn on its fluorescence at 710 nm by 45‐fold in the presence of FAPα, allowing it to effectively recognize keloid cells from normal skin cells. Integration of FNP1 with a simple microneedle‐assisted topical application enables sensitive detection of keloid cells in metabolically‐active human skin tissue with a theoretical limit of detection down to 20 000 cells. 相似文献
902.
Total Synthesis of (6R,10R,13R,14R,16R,17R,19S,20R,21R,24S, 25S,28S,30S,32R,33R,34R,36S,37S,39R)‐Azaspiracid‐3 Reveals Non‐Identity with the Natural Product 下载免费PDF全文
Nathaniel T. Kenton Dr. Daniel Adu‐Ampratwum Dr. Antony A. Okumu Dr. Zhigao Zhang Dr. Yong Chen Dr. Son Nguyen Dr. Jianyan Xu Dr. Yue Ding Dr. Pearse McCarron Dr. Jane Kilcoyne Prof. Dr. Frode Rise Prof. Dr. Alistair L. Wilkins Dr. Christopher O. Miles Prof. Dr. Craig J. Forsyth 《Angewandte Chemie (International ed. in English)》2018,57(3):805-809
A convergent and stereoselective total synthesis of the previously assigned structure of azaspiracid‐3 has been achieved by a late‐stage Nozaki–Hiyama–Kishi coupling to form the C21?C22 bond with the C20 configuration unambiguously established from l ‐(+)‐tartaric acid. Postcoupling steps involved oxidation to an ynone, modified Stryker reduction of the alkyne, global deprotection, and oxidation of the resulting C1 primary alcohol to the carboxylic acid. The synthetic product matched naturally occurring azaspiracid‐3 by mass spectrometry, but differed both chromatographically and spectroscopically. 相似文献
903.
Imaging of Colorectal Cancers Using Activatable Nanoprobes with Second Near‐Infrared Window Emission 下载免费PDF全文
Ge Xu Qinglong Yan Xiaoguang Lv Prof. Ying Zhu Kai Xin Ben Shi Rongchen Wang Jian Chen Wei Gao Prof. Ping Shi Prof. Chunhai Fan Prof. Chunchang Zhao Prof. He Tian 《Angewandte Chemie (International ed. in English)》2018,57(14):3626-3630
Fluorescent probes in the second near‐infrared window (NIR‐II) allow high‐resolution bioimaging with deep‐tissue penetration. However, existing NIR‐II materials often have poor signal‐to‐background ratios because of the lack of target specificity. Herein, an activatable NIR‐II nanoprobe for visualizing colorectal cancers was devised. This designed probe displays H2S‐activated ratiometric fluorescence and light‐up NIR‐II emission at 900–1300 nm. By using this activatable and target specific probe for deep‐tissue imaging of H2S‐rich colon cancer cells, accurate identification of colorectal tumors in animal models were performed. It is anticipated that the development of activatable NIR‐II probes will find widespread applications in biological and clinical systems. 相似文献
904.
Photocatalytic Hydrogen Production Coupled with Selective Benzylamine Oxidation over MOF Composites 下载免费PDF全文
Hang Liu Caiyun Xu Dr. Dandan Li Prof. Dr. Hai‐Long Jiang 《Angewandte Chemie (International ed. in English)》2018,57(19):5379-5383
Photocatalytic water splitting requires separation of the mixed H2 and O2 products and is often hampered by the sluggish O2‐producing half reaction. An approach is now reported to address these issues by coupling the H2‐producing half reaction with value‐added benzylamine oxidation reaction using metal–organic framework (MOF) composites. Upon MOF photoexcitation, the electrons rapidly reduce the protons to generate H2 and the holes promote considerable benzylamine oxidation to N‐benzylbenzaldimine with high selectivity. Further experimental characterizations and theoretical calculation reveal that the highly conjugated s‐triazine strut in the MOF structure is crucial to the efficient charge separation and excellent photocatalytic activity. 相似文献
905.
Transient and Persistent Room‐Temperature Mechanoluminescence from a White‐Light‐Emitting AIEgen with Tricolor Emission Switching Triggered by Light 下载免费PDF全文
Jian‐An Li Jinghong Zhou Dr. Zhu Mao Dr. Zongliang Xie Dr. Zhan Yang Prof. Bingjia Xu Prof. Cong Liu Xin Chen Dingyang Ren Hui Pan Prof. Guang Shi Prof. Yi Zhang Prof. Zhenguo Chi 《Angewandte Chemie (International ed. in English)》2018,57(22):6449-6453
Persistent luminescence from purely organic materials is basically triggered by light and electricity, which largely confines its practical applications. A purely organic AIEgen exhibits not only persistent photoluminescence, but also transient and persistent room‐temperature mechanoluminescence. By simply turning on and off a UV lamp, tricolor emission switching between blue, white, and yellow was achieved. The data from single‐crystal structure analysis and theoretical calculation suggest that mechanism of the observed persistent mechanoluminescence (pML) is correlated with the strong spin–orbit coupling of the bromine atom, as well as the formation of H‐aggregates and restriction of intramolecular motions in noncentrosymmetric crystal structure. These results outline a fundamental principle for the development of new pML materials, providing an important step forward in expanding the application scope of persistent luminescence. 相似文献
906.
Optically Matched Semiconductor Quantum Dots Improve Photophosphorylation Performed by Chloroplasts 下载免费PDF全文
Youqian Xu Dr. Jinbo Fei Guangle Li Tingting Yuan Xia Xu Chenlei Wang Prof. Dr. Junbai Li 《Angewandte Chemie (International ed. in English)》2018,57(22):6532-6535
A natural–artificial hybrid system was constructed to enhance photophosphorylation. The system comprises chloroplasts modified with optically matched quantum dots (chloroplast–QD) with a large Stokes shift. The QDs possess a unique optical property and transform ultraviolet light into available and highly effective red light for use by chloroplasts. This favorable feature enables photosystem II contained within the hybrid system to split more water and produce more protons than chloroplasts would otherwise do on their own. Consequently, a larger proton gradient is generated and photophosphorylation is improved. At optimal efficiency activity increased by up to 2.3 times compared to pristine chloroplasts. Importantly, the degree of overlap between emission of the QDs and absorption of chloroplasts exerts a strong influence on the photophosphorylation efficiency. The chloroplast–QD hybrid presents an efficient solar energy conversion route, which involves a rational combination of a natural system and an artificial light‐harvesting nanomaterial. 相似文献
907.
Dr. Boting Yang Dr. Jin‐Gang Jiang Dr. Hao Xu Prof. Dr. Haihong Wu Prof. Dr. Mingyuan He Prof. Dr. Peng Wu 《Angewandte Chemie (International ed. in English)》2018,57(30):9515-9519
Highly crystalline and (hydro)thermally stable zeolites with extra‐large pores [≥14‐ring (14‐R)] are desirable as catalysts. A novel zeolite, ECNU‐9, with an intersecting 14*12‐R channel system was rationally designed and synthesized by a building block strategy, in which the interlayer expansion of a two‐dimensional silicate structure was realized by combining organic amine assisted layer‐stacking reorganization and subsequent silylation with a square‐shaped single 4‐ring (S4R) silane, 1,3,5,7‐tetramethylcyclotetrasiloxane (TMCS). The PLS‐3 precursor was disassembled into building blocks and then intercalated with flexible and removable organic amine pillars to offer enough interlayer spacing for accommodating TMCS molecules. The additionally introduced building blocks interconnected the neighboring layers to construct new 14‐R and 12‐R pores. ECNU‐9 possesses a well‐ordered structure with a novel topology. The corresponding Ti‐ECNU‐9, with tetrahedral Ti ions in the framework, showed superior catalytic performance in the selective epoxidation of bulky alkenes. 相似文献
908.
Yong Li Yingzheng Shu Muwen Liang Dr. Xilei Xie Dr. Xiaoyun Jiao Prof. Xu Wang Prof. Bo Tang 《Angewandte Chemie (International ed. in English)》2018,57(38):12415-12419
Carbon monoxide (CO) is proposed as an active pharmaceutical agent with promising pharmaceutical prospects, as it has been involved in multifaceted modulation of diverse physiological and pathological processes. However, questions remain for therapeutic application of inhaled CO attributed to the inherent great affinity between CO and hemoglobin. Therefore, a robust platform with the function of CO transport and controllable release, depending on the local status of an organism, is of prominent significance for effectively avoiding the side effects of CO inhalation and optimizing the biological regulation function of CO. Utilizing the oxidative stress biomarker H2O2 as a trigger and combining with photo‐control, a two‐photon H2O2‐activated CO photoreleaser, FB, featuring highly sensitive and specific H2O2 sensing and photocontrollable CO release, was developed and the vasodilation effect of CO against angiotensin II was demonstrated. 相似文献
909.
Stress‐Transfer‐Induced In Situ Formation of Ultrathin Nickel Phosphide Nanosheets for Efficient Hydrogen Evolution 下载免费PDF全文
Shao‐Hai Li Dr. Nan Zhang Dr. Xiuqiang Xie Prof. Dr. Rafael Luque Prof. Dr. Yi‐Jun Xu 《Angewandte Chemie (International ed. in English)》2018,57(40):13082-13085
Ultrathin two‐dimensional (2D) nanostructures have attracted increasing research interest for energy storage and conversion. However, tackling the key problem of lattice mismatch inducing the instability of ulreathin nanostructures during phase transformations is still a critical challenge. Herein, we describe a facile and scalable strategy for the growth of ultrathin nickel phosphide (Ni2P) nanosheets (NSs) with exposed (001) facets. We show that single‐layer functionalized graphene with residual oxygen‐containing groups and a large lateral size contributes to reducing the lattice strain during phosphorization. The resulting nanostructure exhibits remarkable hydrogen evolution activity and good stability under alkaline conditions. 相似文献
910.
Xiao-Qiang Dai Wen-Xiu Xu Ya-Long Wen Xing-Hai Liu Jian-Quan Weng 《Tetrahedron letters》2018,59(30):2945-2949
Metal and acid-free visible light-induced Friedel-Crafts C3-alkylation reactions of indole derivatives were developed using N,N-dimethylanilines as the carbon source. A cheap and readily available organic dye, Rose Bengal, was applied as the photocatalyst. This environmentally friendly transformation afforded C3-alkylated indoles in moderate to good yields under mild conditions. 相似文献