The controllable synthesis of substitutional and interstitial nitrogen-doped manganese dioxide: the effects of doping sites on enhancing the catalytic activity

2020 ◽  
Vol 8 (17) ◽  
pp. 8383-8396 ◽  
Author(s):  
Taohong He ◽  
Xiaoshan Zeng ◽  
Shaopeng Rong
Keyword(s):  
Catalytic Activity ◽  
Manganese Dioxide ◽  
Deep Insight ◽  
Controllable Synthesis ◽  
Nitrogen Doped ◽  
N Doping ◽  
Interstitial Nitrogen ◽  
A Site ◽  
Site Selective ◽  
Insight Into

N atoms were selectively doped at substitutional or interstitial sites in the MnO2 lattice using N2 plasma. This research provides a site-selective N-doping method and a deep insight into the different effects of doping sites.

scholarly journals Flavin-Dependent Halogenases Catalyze Enantioselective Olefin Halocyclization

2020 ◽  
Author(s):  
Dibyendu Mondal ◽  
Brian F. Fisher ◽  
Yuhua Jiang ◽  
Jared C. Lewis
Keyword(s):  
Organic Chemistry ◽  
Catalytic Activity ◽  
High Selectivity ◽  
Organic Transformations ◽  
Docking Simulations ◽  
Bond Forming ◽  
Reaction Optimization ◽  
Wide Range ◽  
Site Selective ◽  
Insight Into

<div><div><div><p>Catalytic enantioselective halocyclization of alkenes is a powerful bond forming tool in synthetic organic chemistry and a key step in the biosynthesis of several natural products. To date, however, no examples of enantioselective halocyclization of simple achiral olefins catalyzed by enzymes have been reported. Herein, we report that flavin-dependent halogenases (FDHs) previously engineered to catalyze site-selective aromatic halogenation can also catalyze bromolactonization of olefins with high enantioselectivity and near-native catalytic proficiency. Analysis of the selectivity of FDH variants along the lineage for the most selective enzymes reveals mutations responsible for the emergence of halocyclase activity, and docking simulations provide insight into the origins of improvements imparted by these mutations. High selectivity was achieved by characterizing and mitigating the release of HOBr from FDH variants using a combination of protein engineering and reaction optimization. Given the range of different halocyclization reactions and other organic transformations that proceed via oxidative halogenation, this expansion of FDH catalytic activity bodes well for the development of a wide range of biocatalytic halogenation reactions.</p></div></div></div>

Plasma-assisted nitrogen doping in Ni–Co–P hollow nanocubes for efficient hydrogen evolution electrocatalysis

Nanoscale ◽  
2020 ◽  
Vol 12 (25) ◽  
pp. 13708-13718
Author(s):  
Qiaomei Luo ◽  
Yiwei Zhao ◽  
Yuyang Qi ◽  
Hongqiang Xin ◽  
Chen Wang ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Hydrogen Evolution ◽  
Nitrogen Doping ◽  
Synergistic Effects ◽  
Hollow Structure ◽  
Experimental Results ◽  
Nitrogen Doped ◽  
N Doping

Plasma-assisted nitrogen doped Ni–Co–P hollow nanocubes were fabricated. Both theoretical and experimental results proved the enhancement of catalytic activity for HER, owing to the synergistic effects of versatile hollow structure and N doping.

scholarly journals Flavin-Dependent Halogenases Catalyze Enantioselective Olefin Halocyclization

2020 ◽  
Author(s):  
Dibyendu Mondal ◽  
Brian F. Fisher ◽  
Yuhua Jiang ◽  
Jared C. Lewis
Keyword(s):  
Organic Chemistry ◽  
Catalytic Activity ◽  
High Selectivity ◽  
Organic Transformations ◽  
Docking Simulations ◽  
Bond Forming ◽  
Reaction Optimization ◽  
Wide Range ◽  
Site Selective ◽  
Insight Into

<div><div><div><p>Catalytic enantioselective halocyclization of alkenes is a powerful bond forming tool in synthetic organic chemistry and a key step in the biosynthesis of several natural products. To date, however, no examples of enantioselective halocyclization of simple achiral olefins catalyzed by enzymes have been reported. Herein, we report that flavin-dependent halogenases (FDHs) previously engineered to catalyze site-selective aromatic halogenation can also catalyze bromolactonization of olefins with high enantioselectivity and near-native catalytic proficiency. Analysis of the selectivity of FDH variants along the lineage for the most selective enzymes reveals mutations responsible for the emergence of halocyclase activity, and docking simulations provide insight into the origins of improvements imparted by these mutations. High selectivity was achieved by characterizing and mitigating the release of HOBr from FDH variants using a combination of protein engineering and reaction optimization. Given the range of different halocyclization reactions and other organic transformations that proceed via oxidative halogenation, this expansion of FDH catalytic activity bodes well for the development of a wide range of biocatalytic halogenation reactions.</p></div></div></div>

Thousands of human sequences provide deep insight into single genomes

Nature ◽  
2020 ◽  
Vol 581 (7809) ◽  
pp. 385-386
Author(s):  
Deanna M. Church
Keyword(s):  
Deep Insight ◽  
Insight Into

Chemical and Electrochemical Heteroepitaxial Growth of Chalcogenide Semiconductors from Solutions

1996 ◽  
Vol 451 ◽  
Author(s):  
D. Lincot ◽  
M. J. Furlong ◽  
M. Froment ◽  
R. Cortes ◽  
M. C. Bernard
Keyword(s):  
Heteroepitaxial Growth ◽  
X Ray Diffraction ◽  
Basic Principles ◽  
Lattice Match ◽  
X Ray ◽  
Chalcogenide Semiconductors ◽  
Influence Of Temperature On ◽  
Deposition Processes ◽  
A Site ◽  
Site Selective

ABSTRACTChalcogenide semiconductors have been deposited epitaxially from aqueous solutions either chemically or electrochemically at growth rates of up to 0.7 μmhr−1. After recalling the basic principles of these deposition processes, results are presented concerning chemically deposited CdS on InP, GaP and CuInSe2 substrates, electrodeposited CdTe on InP, and CdSAnP heterostructures. Characterisation of these structures by RHEED, TEM, HRTEM, and glazing angle X ray diffraction allows to analyse the effects of substrate orientation, polarity, lattice match plus the influence of temperature on epitaxial growth. These results are discussed in terms of self organisation and a site selective growth mechanisms due to the free enegy of formation of each compound.

Mobile-Friendly Dashboards to Display Associations Between Cited-by and Similar Journals on Mobile Health Research: A Bibliometric Study (Preprint)

2018 ◽  
Author(s):  
Tsair-Wei Chien ◽  
Hsien-Yi Wang ◽  
Yang Shao ◽  
Willy Chou
Keyword(s):  
Social Network ◽  
Mobile Health ◽  
Health Research ◽  
Similarity Criteria ◽  
Network Density ◽  
Deep Insight ◽  
Density Indices ◽  
The Subject ◽  
The Given ◽  
Insight Into

BACKGROUND Researchers often spend a great deal of time and effort retrieving related journals for their studies and submissions. Authors often designate one article and then retrieve other articles that are related to the given one using PubMed’s service for finding cited-by or similar articles. However, to date, none present the association between cited-by and similar journals related to a given journal. Authors need one effective and efficient way to find related journals on the topic of mobile health research. OBJECTIVE This study aims (1) to show the related journals for a given journal by both cited-by and similarity criteria; (2) to present the association between cited-by and similarity journals related to a given journal; (3) to inspect the patterns of network density indices among clusters classified by social network analysis (SNA); (4) to investigate the feature of Kendall's coefficient(W) of concordance. METHODS We obtained 676 abstracts since 2013 from Medline based on the keywords of ("JMIR mHealth and uHealth"[Journal]) on June 30, 2018, and plotted the clusters of related journals on Google Maps by using MS Excel modules. The features of network density indices were examined. The Kendall coefficient (W) was used to assess the concordance of clusters across indices. RESULTS This study found that (1) the journals related to JMIR mHealth and uHealth are easily presented on dashboards; (2) a mild association(=0.14) exists between cited-by and similar journals related to JMIR mHealth and uHealth; (3) the median Impact Factor were 3.37 and 2.183 based on the representatives of top ten clusters grouped by the cited-by and similar journals, respectively; (4) all Kendall’s coefficients(i.e., 0.82, 0.89, 0.92, and 0.75) for the four sets of density centrality have a statistically significant concordance (p < 0.05). CONCLUSIONS SNA provides deep insight into the relationships of related journals to a given journal. The results of this research can provide readers with a knowledge and concept diagram to use with future submissions to a given journal in the subject category of Mobile Health Research. CLINICALTRIAL Not available

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