|P.337 right column top paragraph:"An insight into the effects that large cargoes may have on transport dynamics is based on imaging quantum dots [see below] as they are imported through the NPC from the cytoplasm to the nucleoplasm of living cells [ref 49]. Not surprisingly, transport times were found to be long compared with single protein import measurements. Translocation times of 2 s to several minutes, with a median at 34 s, were measured, which are far longer than those found for the export of similarly sized β-actin mRNPs [refs 11, 49] (see also below). This can be explained in part by the fact that quantum dots are rigid substrates and, compared with mRNA complexes, lack the ability to reconfigure during transport. It may also point to the idea that the specific machineries recruited to the mRNP are crucial for ensuring its speedy, as well as specific, transit across the NPC." Wiki:"A quantum dot (QD) is a crystal of semiconductor material whose diameter is on the order of several nanometers - a size which results in its free charge carriers experiencing "quantum confinement" in all three spatial dimensions."