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.
The figure visualizes trending topics in the research field over time, where each line represents a term's presence across years, and the size of the dots indicates the frequency of that term in the literature, highlighting the rise and fall of various research interests with the most recent trends shown towards the right side of the graph.
