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

. 2023 Mar 13;16:821–837. doi: 10.2147/JPR.S403648

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

© 2023 Yang et al.

This work is published and licensed by Dove Medical Press Limited. The full terms of this license are available at https://www.dovepress.com/terms.php and incorporate the Creative Commons Attribution – Non Commercial (unported, v3.0) License (http://creativecommons.org/licenses/by-nc/3.0/). By accessing the work you hereby accept the Terms. Non-commercial uses of the work are permitted without any further permission from Dove Medical Press Limited, provided the work is properly attributed. For permission for commercial use of this work, please see paragraphs 4.2 and 5 of our Terms (https://www.dovepress.com/terms.php).

PMC Copyright notice

The analysis of countries. (A) Heat map showing the distribution and cooperation in the world. (B) Citation of countries, the size of the nodes represents the number of citations. (C) Number of national publications. The size of nodes is determined by the publication numbers. The color indicates the average appearing year.