Cumulative abundances of the reporting of the
occurrences, activities,
and distinct activities all follow the same principal power-law distribution.
A typical curve is shown in A, indicating the two major regions of
overattention to a few and lack of effort on many NPs. Distributing
this NP–abundance–bioactivity space, which was built
on the base of NAPRALERT’s nearly 200,000 compounds, into the
third dimension (B) generates a hyperbolic structure that resembles
a well-known corpus in astrophysics and is, therefore, termed the
black hole of NPs. Panel C shows its various zones that categorize
all NPs by their attached biological knowledge and abundance of the
test parameter (O/A/D; see main text). Similar to a stellar black
hole, density (representing research effort) increases dramatically
toward the bottom (with infinite effort not being a scientific option).
In distinction to its true counterpart, the black hole of NPs has
a (virtual) outlet toward the bottom (C), which release either precious
hits or IMPs.