We demonstrate far-field optical imaging at the nanoscale with unlabeled samples. Subdiffraction resolution images of autofluorescent samples are obtained by depleting the ground state of natural fluorophores by transferring them to a metastable dark state and simultaneously localizing those fluorophores that are transiently returning. Our approach is based on the insight that nanoscopy methods...

A mild tryptic digestion of chloroplast membranes eliminates the effects of saturating concentrations of cations (3 to 5 millimolar MgCl(2)) on chlorophyll fluorescence yield, membrane stacking, and photosystem II photochemical efficiency in spinach. At the same time, the negative surface potential of the membranes is increased (by trypsin) as revealed by studies with 9-aminoacridine. High conc...

Abstract Soils naturally low in organic matter need to be amended with recycled materials that would boost soil health. In this work, we tested insect frass, the excrements of yellow mealworm, Tenebrio molitor , as a novel amendment spinach cultivation. 60-day pot experiment ( Spinacia oleracea ), added frass at rates 0, 0.25, 0.5, and 1%, well an inorganic nitrogen-phosphorus-potassium (NPK) f...