Journal: Nature Communications

Article Title: A noninvasive fluorescence imaging-based platform measures 3D anisotropic extracellular diffusion

doi: 10.1038/s41467-021-22221-0

Figure Lengend Snippet: a Schematic of the LiFT-FRAP system. A light sheet illuminates a thin slice of the sample and scans a 3D volume [inset (i)]. Emitted fluorescence is collected by the detection objective [inset (ii)]. A high-intensity bleaching laser creates a bleaching volume by performing 3D point-scanning at the center of the 3D illuminated volume [inset (iii)]. λ/2, half waveplate; PBS, polarizing beamsplitter; S, shutter; 2D GS, 2D galvanometer system; MM, MEMS mirror; IO, illumination objective; DO, detection objective; P, piezo stage; DIC, dichroic mirror; LPF, low-pass filter; T, tube lens; λ ill , illumination laser; λ det , detected emission fluorescence; λ ble , bleaching laser; b LiFT-FRAP data collection and analysis workflow. In a LiFT-FRAP experiment, prebleaching images are first recorded, followed by the photobleaching process. Postbleaching images are collected instantly after bleaching. Time series of 3D LiFT-FRAP image data that record the 3D fluorescence recovery process was processed and then converted to the frequency domain through a 3D spatial Fourier transformation. Based on our 3D FRAP theory (Supplementary Note ), the normalized solute concentration in the frequency domain \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\tilde C/\tilde C_0$$\end{document} C ~ / C ~ 0 (gray circles) will gradually decrease with the 3D fluorescence recovery ( u , v , w are the spatial frequency coordinate. The unit of u , v , w is µm −1 ). Fitted with the theoretical equations (red line), the diffusivity value is determined. Then each component of the 3D diffusion tensor can be calculated (Supplementary Note ).

Article Snippet: A 2D gimbal MEMS scanning mirror (gold coated, integrated, diameter 800 μm, Mirrorcle, Richmond, CA) scanned the extended laser along the y axis to generate a light sheet (Supplementary Fig. ) and along the z axis to achieve 3D illumination.

Techniques: Fluorescence, Transformation Assay, Concentration Assay, Diffusion-based Assay

Journal: Biomedical Optics Express

Article Title: Volumetric directional optical coherence tomography

doi: 10.1364/BOE.447882

Figure Lengend Snippet: Schematic diagram of the VD-OCT system. The purple dashed box on the bottom right corner illustrates the spectrometer combined with a 2048-pixel camera. The dark-yellow dashed box on the bottom center shows the schematic of the reference arm. The red dashed box on the bottom center illustrates the regular OCT galvanometer scanning system. The cyan dashed box on the bottom left corner demonstrates the VD-OCT system when both the galvanometer scanner and FSM are activated synchronously. The red dot lines represent the beam envelope with different scanning angle configurations of FSM. SLD: superluminescent diode; M: mirror; DM: deformable mirror; L1-L9: lens; C1-C3: collimator; Galvo-X/Galvo-Y: the fast/slow axis of galvanometer scanner; FSM: fast steering mirror; NI DAQ: multifunctional data acquisition and control card; PC: polarization controller; FC: fiber coupler; GPU: graphics processing unit.

Article Snippet: The sample arm of our VD-OCT system was comprised of a deformable mirror (DM) (DMP40-F01, Thorlabs Inc., USA), a paired galvanometer scanning mirror (simply as “Galvo” in the following discussions) (Saturn-5B, Pangolin Laser Systems Inc., USA) that was conjugated to the pupil plane, a fast steering mirror (FSM) (OIM5002, Optics In Motion LLC, USA) that was conjugated to the retina plane, and several telescope relay lenses.

Techniques: Control