The trick is to distinguish cancer cells from nearby normal cells, which can be achieved by matching tattoo ink, nanoparticles, or edible dyes. < / P > < p > after injecting this mixed contrast agent into patients, doctors can more easily determine the cancer area, and the imaging contrast is not inferior to or even better than that of traditional methods. < / P > < p > researchers call it optical inks, in which nanoparticles are specifically developed for cancer cells and have been approved by FDA. Cristina Zavaleta, research leader, explained that small molecules of dyes can initially accumulate in tumor areas, but there is not much time left for doctors because they will be excreted quickly. < / P > < p > as a contrast, the new nanoparticles have moderate size and strong permeability, so they can stay in the tumor area for a longer time. If a small amount of dye is wrapped in nanoparticles, better development effect can be obtained. Google said the proposed media negotiation rules would put its free services in Australia at “risk”