particle image velocimetry package pivlab  (MathWorks Inc)

Journal: Nature Communications

Article Title: Periodic splay Fréedericksz transitions in a ferroelectric nematic

doi: 10.1038/s41467-025-55827-9

Figure Lengend Snippet: a PolScope Microimager texture of the in-plane splay and bend for the normal incidence of light; wavelength 535 nm. b Polarizing microscopy of square lattice of +1/−1 defects. c Potential difference measured at the N F cell electrodes; the generated voltage. d Transmitted intensity as a function of time at locations L1’–L4’. \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${{\bf{P}}}$$\end{document} P oscillates with the frequency of the applied field. Incident laser beam makes an angle \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\beta=$$\end{document} β = 15° with the normal \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\hat{{{\bf{z}}}}$$\end{document} z ^ to the cell. Dashed line corresponds to zero voltage. In ( a – d ), \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$d$$\end{document} d = (3.0 ± 0.1) μm; applied voltage from the source U rms = 30 V, 200 kHz sinusoidal waveform; 120 °C. e Particle image velocimetry (PIVlab, Matlab) integrated trajectories of fluorescent spherical flow tracers of the diameter 300 nm in the square lattice of +1/−1 defects; d = (4.8 ± 0.1) μm cell; sinusoidal wave of voltage 4.5 V and frequency f = 200 kHz; 115 °C. f the same cell, in-plane velocity field of the tracers.

Article Snippet: Their trajectories are uncovered by particle image velocimetry package PIVLab in Matlab.

Techniques: Microscopy, Generated

Journal: bioRxiv

Article Title: Motility induced fracture reveals a ductile to brittle crossover in the epithelial tissues of a simple animal

doi: 10.1101/676866

Figure Lengend Snippet: (A) Experimental tagging techniques: (i) Ventral epithelium - A fluorescent lysotracker dye stains the acidic granules present in the lipophil cells, and provides a dense tagging of the entire ventral epithelium at large fields of view (∼3 mm) (Methods). (ii) Dorsal epithelium - We developed an assay to coat the surface of the epithelium with sticky fluorescent microspheres / microbeads. This provides a coarse-grained tagging (1 bead per 8 cells) of the entire dorsal epithelium at large fields of view (∼6 mm) and enables high-speed (10 fps) and long duration (∼1-5 hours) imaging (Methods). Right Insets display control experiments demonstrating that microspheres bind on cell membrane. (B) Computational data analysis techniques: We employ Flowtrace for visualization of particle trajectories, Particle tracking for quantitative non-affine motion analysis, and Particle Image Velocimetry to measure velocity fields and internal strain rate.

Article Snippet: We employed Particle Image Velocimetry (PIV) analysis (PIVlab package in MATLAB) to quantify the flow-fields in the dorsal layer sticky-microbeads time-lapse datasets in large width (13×13mm square) confined PDMS milli-fluidic chips with variable fields-of-view.

Techniques: Imaging, Control, Membrane