Global Research Trends in Tendon Stem Cells from 1991 to 2020: A Bibliometric and Visualized Study

Figure 6

Cooccurrence analysis of global research of tendon stem cells. (a) Mapping on keywords in the research of tendon stem cells; the size of the nodes indicates the frequency, and the keywords are classified into five clusters: animal study (red color), tissue engineering (yellow color), mechanism research (green color), stem cell research (blue color), and clinical study (purple color). (b) Distribution of keywords based upon their time of appearance; purple keywords appeared earlier than green ones, and yellow keywords appear later than both of purple and green keywords.

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