Visualizing Escherichia coli Sub-Cellular Structure Using Sparse Deconvolution Spatial Light Interference Tomography

Studying the 3D sub-cellular structure of living cells is essential to our understanding of biological function. However, tomographic imaging of live cells is challenging mainly because they are transparent, i.e., weakly scattering structures. Therefore, this type of imaging has been implemented largely using fluorescence techniques. While confocal fluorescence imaging is a common approach to achieve sectioning, it requires fluorescence probes that are often harmful to the living specimen. On the other hand, by using the intrinsic contrast of the structures it is possible to study living cells in a non-invasive manner. One method that provides high-resolution quantitative information about nanoscale structures is a broadband interferometric technique known as Spatial Light Interference Microscopy (SLIM). In addition to rendering quantitative phase information, when combined with a high numerical aperture objective, SLIM also provides excellent depth sectioning capabilities. However, like in all linear optical systems, SLIM's resolution is limited by diffraction. Here we present a novel 3D field deconvolution algorithm that exploits the sparsity of phase images and renders images with resolution beyond the diffraction limit. We employ this label-free method, called deconvolution Spatial Light Interference Tomography (dSLIT), to visualize coiled sub-cellular structures in E. coli cells which are most likely the cytoskeletal MreB protein and the division site regulating MinCDE proteins. Previously these structures have only been observed using specialized strains and plasmids and fluorescence techniques. Our results indicate that dSLIT can be employed to study such structures in a practical and non-invasive manner

Detailed Chemical Characterization and Biological Propensities of Malabaila lasiocarpa Extracts: An Endemic Plant to Turkey

This study focused on the biological evaluation and chemical characterization of Malabaila lasiocarpa Boiss. (M. lasiocarpa) (Family: Apiaceae). The phytochemical profile, antioxidant, enzyme inhibitory of the methanolic, aqueous, dichloromethane, hexane extracts were investigated. Based on UHPLC-HRMS analyses, a total of 101 peaks were annotated or identified for the first time in M. lasiocarpa extracts. They include hydroxybenzoic, hydroxycinnamic, acylquinic acids and their glycosides, C- and O-glycosyl and O-diglycosyl flavonoids. In addition, 10 simple mono- and disubstituted coumarins together with 10 furanocoumarins were tentatively annotated. The methanolic extract possessing the highest phenolic (24.36±0.60 mg gallic acid equivalent/g extract) and flavonoid (69.15±0.37 mg rutin equivalent/g extract) content also exhibited the strongest radical scavenging potential against 2,2-diphenyl-1 picrylhydrazyl (21.73±0.42 mg Trolox equivalent/g extract, respectively), and highest reducing capacity (57.81±0.97 and 28.00±0.40 mg Trolox equivalent/g extract, for cupric reducing antioxidant capacity and ferric reducing antioxidant power, respectively). The dichloromethane extract substantially depressed the tyrosinase (73.92±5.37 mg kojic acid equivalent/g extract), α-amylase (0.63±0.01 mmol acarbose equivalent/g extract) and α-glucosidase (0.69±0.02 mmol acarbose equivalent/g extract) enzymes. This study has produced critical scientific data on M. lasiocarpa which are potential contenders for the development of novel phyto-pharmaceuticals