Topic Tree of PMC0051XXXX
Click on the arrow on the left to collapse/expand a topic hierarchy.
Click on a topic to show the documents belonging to that topic and the counts by year.
Use the "Show Levels" button to select the levels (top-bottom) that you want to show.
Use the "Filter" button to show only topics that contain the keyword along with their ancestors and descendants. Use the "Clear" button to show all topics.