Progress in electrochemical analysis of flavonoids: a scientometric analysis in CiteSpace

2021 ◽  
Vol 17 ◽  
Author(s):  
Jingzhou Zhang ◽  
Zaifu Zhou ◽  
Qingxin Kong

Background: Flavonoids are a large class of phenolic compounds, which generally refer to two benzene rings (A ring, B ring) with phenolic hydroxyl groups connected to each other through three central carbon atoms, that is, a series of C6-C3-C6 basic core compounds. Because of its potential medicinal value, the research on flavonoids has aroused great interest. Methods: This review aims to identify the research progress and development trends of electrochemical analysis of flavonoids. We retrieved published papers (1998–2020) from Scientific Citation Index Expanded (SCIE) database of the WoS with a topic search related to electrochemical analysis of flavonoids. Results: In this paper, the research progress in electrochemical analysis of flavonoids has been reviewed. Antioxidant activity of flavonoids is the hot area that attracted considerable attention because it directly affects the application of flavonoids. Different analytical methods also received attention of researchers, such as cyclic voltammetry and capillary electrophoresis. This is because advanced analysis technology can be useful for evaluating the property of flavonoids. Conclusion: The research progress and development trends were analyzed based on CiteSpace software of text mining and visualization. Three peaks of this research area can be found as 2004-2005, 2011-2013 and 2016-2018. Although the different countries are conducting research on electrochemical analysis of flavonoids, most of these institutions are not related to each other.

Molecules ◽  
2021 ◽  
Vol 26 (8) ◽  
pp. 2131
Author(s):  
Leonardo Dalseno Antonino ◽  
Júlia Rocha Gouveia ◽  
Rogério Ramos de Sousa Júnior ◽  
Guilherme Elias Saltarelli Garcia ◽  
Luara Carneiro Gobbo ◽  
...  

Several efforts have been dedicated to the development of lignin-based polyurethanes (PU) in recent years. The low and heterogeneous reactivity of lignin hydroxyl groups towards diisocyanates, arising from their highly complex chemical structure, limits the application of this biopolymer in PU synthesis. Besides the well-known differences in the reactivity of aliphatic and aromatic hydroxyl groups, experimental work in which the reactivity of both types of hydroxyl, especially the aromatic ones present in syringyl (S-unit), guaiacyl (G-unit), and p-hydroxyphenyl (H-unit) building units are considered and compared, is still lacking in the literature. In this work, the hydroxyl reactivity of two kraft lignin grades towards 4,4′-diphenylmethane diisocyanate (MDI) was investigated. 31P NMR allowed the monitoring of the reactivity of each hydroxyl group in the lignin structure. FTIR spectra revealed the evolution of peaks related to hydroxyl consumption and urethane formation. These results might support new PU developments, including the use of unmodified lignin and the synthesis of MDI-functionalized biopolymers or prepolymers.


Molecules ◽  
2021 ◽  
Vol 26 (13) ◽  
pp. 4018
Author(s):  
Hao Song ◽  
Xiaodong Ding ◽  
Zixian Cui ◽  
Haohao Hu

Acoustic metamaterials are materials with artificially designed structures, which have characteristics that surpass the behavior of natural materials, such as negative refraction, anomalous Doppler effect, plane focusing, etc. This article mainly introduces and summarizes the related research progress of acoustic metamaterials in the past two decades, focusing on meta-atomic acoustic metamaterials, metamolecular acoustic metamaterials, meta-atomic clusters and metamolecule cluster acoustic metamaterials. Finally, the research overview and development trend of acoustic metasurfaces are briefly introduced.


2019 ◽  
Author(s):  
Tushar Hasanuzzaman ◽  
Bui Nhat Vuong

Traditionally women are expected to do all household works. The increasing working women lead to review this social convention and practice the strategies in balancing work-family lives. Last few decades, it has received much importance in conducting research on developed and developing country. In a less developed country like Bangladesh, very few studies had taken place to investigate the educated women in the higher educational sector. This qualitative study, mainly, is based on the unique experiences of female faculty of the private university in Bangladesh and focuses on the strategies they employ in balancing work-family lives. Nine participants were chosen purposefully with maximum variation and conducted in-depth interview. The authors used a thematic analysis of the interview data presented three themes including: (a) supportive environment at family and workplace, (b) time management and setting up the priorities, and (c) locus of control. The study concludes that the female faculty members emphasize more on families rather than work in balancing their work-family lives; but the behavior is different in case of unmarried women or who stay separated from husband, they like to focus on work. The strategies and overall situation of female faculty members were discussed and recommended further research area.


2009 ◽  
Vol 2009 (4) ◽  
pp. 229-230 ◽  
Author(s):  
Nobuhiro Sato ◽  
Hiroyuki Endo

A mild methylation of phenolic hydroxyl groups with iodomethane was enabled in the presence of sodium bis(trimethylsilyl)amide at room temperature. The reverse reaction, namely demethylation of methyl phenyl ethers, was easily achieved by microwave heating with neat iodotrimethylsilane.


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