Figure - PMC

Skip to main content

An official website of the United States government

Here's how you know

Here's how you know

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you've safely connected to the .gov website. Share sensitive information only on official, secure websites.

View full-text article in PMC

. 2021 Oct 26;8:740710. doi: 10.3389/fmed.2021.740710

Search in PMC
Search in PubMed
View in NLM Catalog
Add to search

Copyright © 2021 Hu, Alimire, Lai, Hu, Chen and Li.

This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.

PMC Copyright notice

Analysis of keywords and co-cited references. (A) Co-occurrence network map of keywords; (B) Cluster map of keywords. Each nodes represented a keyword. All the keywords were categorized into 11 clusters, among which the cluster#0, #1, and #4 were the latest (mean year = 2017). The cluster label was the central keyword among all keywords included in the cluster; (C) Timeline view of co-cited references. Each node represented a cited reference, and the number of citation was reflected by the node size. The node volumes of the cluster decreased gradually from cluster#0 to cluster#6. The label of each cluster represented the main topic of the references included in the cluster. The clusters could be ranked by mean year from oldest to latest, namely #5 (2010), #7 (2011), #4 (2012), #0 (2013), #2 (2014), #3 (2014), #1 (2016), and #6 (2018).