Figure 1.

Temporal evolution of fields of application for regenerative medicine by stem cells. Studies using hematopoietic stem cell (HSC) transplant (with total-body irradiation, myeloablative or nonmyeloablative regimens, or genetically modified HSCs) were excluded from this figure. This chord diagram represents the proportion of studies dealing with each field of application (branch of the Medical Subject Heading [MeSH] classification [Diseases]) and links them to their respective start dates. The gray levels for the different years (on the left) and the color codes for the different fields of application (on the right) are shown beside their respective labels, listed in order of frequency (this order will be maintained hereafter). The outer ring of the figure contains the proportion of studies and the inner circle shows their absolute numbers. In each ring, the contribution of each field of application in each time category is coded by colored segments, and vice versa. These colored segments are also sorted by importance. For instance, and reading the diagram from MeSH classification, in the field of cardiovascular regeneration, 70 trials started in 2006–2008 (indicated in the inner part of the circular diagram) and made up 36% of the fields in 2006–2008 (indicated on the left of the outer part of the circular diagram). Conversely, 25% of cardiovascular diseases trials were started in 2006–2008 (indicated on the right of the outer part of the circular diagram).