We discovered that palmatine (PAL), a well-known natural product, was inducing the fluorogenic fixation of live cells upon visible light irradiation. This ultrafast phenomenon proceeded under high spatiotemporal control down to single cells (SC), with persistence of well-preserved fixed-labeled cells. Cell optofixing was mediated by PAL interaction with nuclear and mitochondrial DNA, yielding reactive oxygen species (ROS) mainly singlet oxygen (1O2), lipid peroxidation (LPO) and LPO-derived fixing aldehydes. We found that other DNA dyes including conventional trackers were also capable of optofixing cells, furnishing a consistent methodology (fluorophore-mediated optofixation, FLUMO) across the visible spectrum. Our results pave the way for the functional ablation and labeling of target cell populations using small fluorophores, with applications in SC, organoid and whole organism biology.
Depression subtype classification from social media posts: few-shot prompting vs. fine-tuning of large language models
BackgroundSocial media provides timely proxy signals of mental health, but reliable tweet-level classification of depression subtypes remains challenging due to short, noisy text, overlapping symptomatology,