substrate structure
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2021 ◽  
pp. 146144482110594
Author(s):  
Lea Püchel ◽  
Christian-Mathias Wellbrock

Our daily dealings with media products are shaped by the use of generic designations such as journalistic presentation modes, for example, news, commentary, and Instagram-story. Yet, scholarship has examined presentation modes only selectively and lacks empirical investigations in this domain. Based on literature and a quantitative content analysis of jury protocols of the German online journalism award “Grimme Online Award,” this article explores how presentation modes are constructed and further develops a framework for a categorization of presentation modes with eight dimensions: Content and Function, Author, Sources, Periodicity, Material Substrate, Structure, Media, and Interactive-Engagement Elements. This study is the first to empirically assess journalistic presentation mode dimensions and manifestations.


2021 ◽  
Author(s):  
Jichao Xiao ◽  
John Montgomery

A simple procedure is reported for the nickel-catalyzed defluorinative alkylation of unactivated aliphatic aldehydes. The process involves the catalytic reductive union of trifluoromethyl styrenes with aldehydes using a nickel complex of a 6,6’-disubstituted bipyridine ligand with zinc metal as the terminal reductant. The protocol is distinguished by its broad substrate scope, mild conditions, and simple catalytic setup. Reaction outcomes are consistent with the intermediacy of an alpha-silyloxy(alkyl)nickel intermediate generated by a low-valent nickel catalyst, silyl electrophile, and the aldehyde substrate. Mechanistic findings with cyclopropanecarboxaldehyde provide insights into nature of the reactive intermediates and illustrate fundamental reactivity differences that are governed by subtle changes in ligand and substrate structure.


2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Zhiyou Wang ◽  
Maojin Wang

In this work, we reported a wireless network composed of silver film-based graphene oxide-fluorescence resonance energy transfer (GO-FRET) lysozyme aptasensor nodes. At the sensor node level, we optimized silver substrate structure, concentrations of the aptamers, and graphene oxide and tested lysozyme detection performance with a model analyte. At the network level, we analyzed the complexity and transmission success rate using fractal measurements. We implemented the wireless network composed of the aptasensor with a portable Wi-Fi fluorescent reader. Transmission success rate testing results show that an increase in node hops can promote the rate of transmission success dramatically. When the hop count is larger than 6, the rate of transmission success can reach more than 90% if the transmission failure probability and sleep probability are 0.1 and 0.5, respectively.


Author(s):  
Haohao Bi ◽  
Bo Wang ◽  
Huajiang Ouyang ◽  
Zichen Deng ◽  
Bohan Zhang

Catalysts ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 1317
Author(s):  
Alena Krupková ◽  
Klára Kubátová ◽  
Lucie Červenková Šťastná ◽  
Petra Cuřínová ◽  
Monika Müllerová ◽  
...  

Three series of poly(ionic) carbosilane dendrimers peripherally functionalized with imidazolium groups substituted on N-3 with methyl, isopropyl and 2,6-diisopropylphenyl (Dipp) were prepared up to the 3rd generation together with model monovalent imidazolium iodides and used as N-heterocyclic carbene (NHC) precursors. Catalytic activity of model and dendritic NHCs generated in situ by deprotonation with DBU was tested in redox esterification of α,β-unsaturated aldehydes and the influence of substitution, dendrimer generation, temperature and substrate structure on the reaction outcome was evaluated. Dipp substituted NHCs showed high activity and selectivity in the reaction with primary alcohols. Effectiveness of organic solvent nanofiltration for the recycling of dendritic NHCs was demonstrated on the 1st generation Dipp substituted catalyst in model redox esterification of cinnamaldehyde with benzyl alcohol. A marked increase in both activity and selectivity in the first four reaction runs was observed and this improved performance was preserved in the following catalytic cycles.


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