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981.
Yu Wang Kiran M. Patil Shuanghong Yan Panke Zhang Weiming Guo Yuqin Wang Hong‐Yuan Chen Dennis Gillingham Shuo Huang 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(25):8520-8524
O6‐carboxymethylguanine (O6‐CMG) is a highly mutagenic alkylation product of DNA, triggering transition mutations relevant to gastrointestinal cancer. However, precise localization of a single O6‐CMG with conventional sequencing platforms is challenging. Here nanopore sequencing (NPS), which directly senses single DNA bases according to their physiochemical properties, was employed to detect O6‐CMG. A unique O6‐CMG signal was observed during NPS and a single‐event call accuracy of >95 % was achieved. Moreover, O6‐CMG was found to be a replication obstacle for Phi29 DNA polymerase (Phi29 DNAP), suggesting this lesion could cause DNA sequencing biases in next generation sequencing (NGS) approaches. 相似文献
982.
Carlos M. Cruz Irene R. Mrquez Silvia Castro‐Fernndez Juan M. Cuerva Ermelinda Maas Araceli G. Campaa 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(24):8152-8156
A unique rippled nanographene consisting of 52 fused rings is presented in which six out‐of‐plane motifs are fully fused into a triangular aromatic surface with a size of approximately 2.5 nm. Three units of an unprecedented fully lateral π‐extended octabenzo[5]helicene together with three units of saddle‐shaped heptagonal rings are combined in a single structure, leading to a well‐soluble warped nanographene. The two diastereomeric pairs of possible enantiomers were isolated, and their linear, non‐linear, and chiroptical properties were evaluated, revealing outstanding quantum yield and brightness values at low energy, together with good chiroptical responses in both absorption and emission. 相似文献
983.
Rufan Chen Ji‐Long Shi Yuan Ma Guiqing Lin Xianjun Lang Cheng Wang 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(19):6496-6500
The construction of stable covalent organic frameworks (COFs) for various applications is highly desirable. Herein, we report the synthesis of a novel two‐dimensional (2D) porphyrin‐based sp2 carbon‐conjugated COF (Por‐sp2c‐COF), which adopts an eclipsed AA stacking structure with a Brunauer—Emmett—Teller surface area of 689 m2 g?1. Owing to the C=C linkages, Por‐sp2c‐COF shows a high chemical stability under various conditions, even under harsh conditions such as 9 m HCl and 9 m NaOH solutions. Interestingly, Por‐sp2c‐COF can be used as a metal‐free heterogeneous photocatalyst for the visible‐light‐induced aerobic oxidation of amines to imines. More importantly, in comparison to imine‐linked Por‐COF, the inherent structure of Por‐sp2c‐COF equips it with several advantages as a photocatalyst, including reusability and high photocatalytic performance. This clearly demonstrates that sp2 carbon‐linked 2D COFs can provide an interesting platform for heterogeneous photocatalysis. 相似文献
984.
Xin‐Wei Zhang Alexander Oleinick Hong Jiang Quan‐Lan Liao Quan‐Fa Qiu Irina Svir Yan‐Ling Liu Christian Amatore Wei‐Hua Huang 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(23):7835-7838
The existence of a homeostatic mechanism regulating reactive oxygen/nitrogen species (ROS/RNS) amounts inside phagolysosomes has been invoked to account for the efficiency of this process but could not be unambiguously documented. Now, intracellular electrochemical analysis with platinized nanowire electrodes (Pt‐NWEs) allowed monitoring ROS/RNS effluxes with sub‐millisecond resolution from individual phagolysosomes impacting onto the electrode inserted inside a living macrophage. This shows for the first time that the consumption of ROS/RNS by their oxidation at the nanoelectrode surface stimulates the production of significant ROS/RNS amounts inside phagolysosomes. These results establish the existence of the long‐postulated ROS/RNS homeostasis and allows its kinetics and efficiency to be quantified. ROS/RNS concentrations may then be maintained at sufficiently high levels for sustaining proper pathogen digestion rates without endangering the macrophage internal structures. 相似文献
985.
Xing Huang Detre Teschner Maria Dimitrakopoulou Alexey Fedorov Benjamin Frank Ralph Kraehnert Frank Rosowski Harry Kaiser Stephan Schunk Christiane Kuretschka Robert Schlgl Marc‐Georg Willinger Annette Trunschke 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(26):8801-8805
The direct conversion of syngas to ethanol, typically using promoted Rh catalysts, is a cornerstone reaction in CO2 utilization and hydrogen storage technologies. A rational catalyst development requires a detailed structural understanding of the activated catalyst and the role of promoters in driving chemoselectivity. Herein, we report a comprehensive atomic‐scale study of metal–promoter interactions in silica‐supported Rh, Rh–Mn, and Rh–Mn–Fe catalysts by aberration‐corrected (AC) TEM. While the catalytic reaction leads to the formation of a Rh carbide phase in the Rh–Mn/SiO2 catalyst, the addition of Fe results in the formation of bimetallic Rh–Fe alloys, which further improves the selectivity and prevents the carbide formation. In all promoted catalysts, Mn is present as an oxide decorating the metal particles. Based on the atomic insight obtained, structural and electronic modifications induced by promoters are revealed and a basis for refined theoretical models is provided. 相似文献
986.
Beomsue Kim Masahiro Fukuda Jung‐Yeol Lee Dongdong Su Srikanta Sanu Aymeric Silvin Audrey T. T. Khoo Taejoon Kwon Xiao Liu Weijie Chi Xiaogang Liu Sejong Choi Diana S. Y. Wan Sung‐Jin Park Jin‐Soo Kim Florent Ginhoux H. Shawn Je Young‐Tae Chang 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(24):8056-8060
Microglia, the brain‐resident macrophage, are involved in brain development and contribute to the progression of neural disorders. Despite the importance of microglia, imaging of live microglia at a cellular resolution has been limited to transgenic mice. Efforts have therefore been dedicated to developing new methods for microglia detection and imaging. Using a thorough structure–activity relationships study, we developed CDr20, a high‐performance fluorogenic chemical probe that enables the visualization of microglia both in vitro and in vivo. Using a genome‐scale CRISPR‐Cas9 knockout screen, the UDP‐glucuronosyltransferase Ugt1a7c was identified as the target of CDr20. The glucuronidation of CDr20 by Ugt1a7c in microglia produces fluorescence. 相似文献
987.
988.
Ivan A. Gagarinov Tiehai Li Na Wei Javier SastreTorao Robert P. deVries Margreet A. Wolfert Geert‐Jan Boons 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(31):10657-10662
We describe a chemoenzymatic strategy that can give a library of differentially fucosylated and sialylated oligosaccharides starting from a single chemically synthesized tri‐N‐acetyllactosamine derivative. The common precursor could easily be converted into 6 different hexasaccharides in which the glucosamine moieties are either acetylated (GlcNAc) or modified as a free amine (GlcNH2) or Boc (GlcNHBoc). Fucosylation of the resulting compounds by a recombinant fucosyl transferase resulted in only modification of the natural GlcNAc moieties, providing access to 6 selectively mono‐ and bis‐fucosylated oligosaccharides. Conversion of the GlcNH2 or GlcNHBoc moieties into the natural GlcNAc, followed by sialylation by sialyl transferases gave 12 differently fucosylated and sialylated compounds. The oligosaccharides were printed as a microarray that was probed by several glycan‐binding proteins, demonstrating that complex patterns of fucosylation can modulate glycan recognition. 相似文献
989.
990.
Lin Huang Jiasui Zou Jin‐Yu Ye Zhi‐You Zhou Zhang Lin Xiongwu Kang Prashant K. Jain Shaowei Chen 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(26):8886-8890
Localized surface plasmon resonance (LSPR) excitation of noble metal nanoparticles has been shown to accelerate and drive photochemical reactions. Here, LSPR excitation is shown to enhance the electrocatalysis of a fuel‐cell‐relevant reaction. The electrocatalyst consists of PdxAg alloy nanotubes (NTs), which combine the catalytic activity of Pd toward the methanol oxidation reaction (MOR) and the visible‐light plasmonic response of Ag. The alloy electrocatalyst exhibits enhanced MOR activity under LSPR excitation with significantly higher current densities and a shift to more positive potentials. The modulation of MOR activity is ascribed primarily to hot holes generated by LSPR excitation of the PdxAg NTs. 相似文献