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Holographic microscopy

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https://www.readbyqxmd.com/read/29660600/holographic-imaging-and-photostimulation-of-neural-activity
#1
REVIEW
Weijian Yang, Rafael Yuste
Optical imaging methods are powerful tools in neuroscience as they can systematically monitor the activity of neuronal populations with high spatiotemporal resolution using calcium or voltage indicators. Moreover, caged compounds and optogenetic actuators enable to optically manipulate neural activity. Among optical methods, computer-generated holography offers an enormous flexibility to sculpt the excitation light in three-dimensions (3D), particularly when combined with two-photon light sources. By projecting holographic light patterns on the sample, the activity of multiple neurons across a 3D brain volume can be simultaneously imaged or optically manipulated with single-cell precision...
April 13, 2018: Current Opinion in Neurobiology
https://www.readbyqxmd.com/read/29652386/automatic-phase-aberration-compensation-for-digital-holographic-microscopy-based-on-phase-variation-minimization
#2
Shuo Liu, Qiusheng Lian, Yuan Qing, Zhaopeng Xu
We propose a numerical and totally automatic phase aberration compensation method in digital holographic microscopy. The phase aberrations are extracted in a nonlinear optimization procedure in which the phase variation of the reconstructed object wave is minimized. Not only phase curvature but also high-order aberrations could be corrected without extra devices. The correction is directly carried out with the wrapped phase map, which is not affected by phase unwrapping or fitting errors. Numerical simulation proves that the proposed method is more accurate than the conventional surface fitting method without selecting a cell-free background...
April 15, 2018: Optics Letters
https://www.readbyqxmd.com/read/29652385/multiple-patterning-of-holographic-photopolymers-for-increased-refractive-index-contrast
#3
David J Glugla, Madeline B Chosy, Marvin D Alim, Kimberly K Childress, Amy C Sullivan, Robert R McLeod
We demonstrate that multiple exposures of a two-component holographic photopolymer can quadruple the refractive index contrast of the material beyond the single-exposure saturation limit. Quantitative phase microscopy of isolated structures written by laser direct-write lithography is used to characterize the process. This technique reveals that multiple exposures are made possible by diffusion of the chemical components consumed during writing into the previously exposed regions. The ultimate index contrast is shown to be limited by the solubility of fresh components into the multiply exposed region...
April 15, 2018: Optics Letters
https://www.readbyqxmd.com/read/29644532/methamphetamine-induces-apoptosis-of-microglia-via-the-intrinsic-mitochondrial-dependent-pathway
#4
Anna V Sharikova, Elizabeth Quaye, Jun Yong Park, Maxwell C Maloney, Habben Desta, Ramkumar Thiyagarajan, Kenneth L Seldeen, Neil U Parikh, Parteet Sandhu, Alexander Khmaladze, Bruce R Troen, Stanley A Schwartz, Supriya D Mahajan
Methamphetamine (METH) is a drug of abuse, the acute and chronic use of which induces neurotoxic responses in the human brain, ultimately leading to neurocognitive disorders. Our goals were to understand the impact of METH on microglial mitochondrial respiration and to determine whether METH induces the activation of the mitochondrial-dependent intrinsic apoptosis pathway in microglia. We assessed the expression of pro- apoptosis genes using qPCR of RNA extracted from a human microglial cell line (HTHU). We examined the apoptosis-inducing effects of METH on microglial cells using digital holographic microscopy (DHM) to quantify real-time apoptotic volume decrease (AVD) in microglia in a noninvasive manner...
April 11, 2018: Journal of Neuroimmune Pharmacology: the Official Journal of the Society on NeuroImmune Pharmacology
https://www.readbyqxmd.com/read/29622579/high-throughput-non-perturbing-quantification-of-lipid-droplets-with-digital-holographic-microscopy
#5
Vasco Campos, Benjamin Rappaz, Fabien Kuttler, Gerardo Turcatti, Olaia Naveiras
In vitro differentiating adipocytes are sensitive to liquid manipulations and have the tendency to float. Assessing adipocyte differentiation using current microscopy techniques involves cell staining and washing, while using flow cytometry involves cell retrieval in suspension. These methods induce biases, are difficult to reproduce and involve tedious optimizations. In this study we present Digital Holographic Microscopy (DHM) as a label-free, non-perturbing means to quantify lipid droplets in differentiating adipocytes in a robust medium- to high-throughput manner...
April 5, 2018: Journal of Lipid Research
https://www.readbyqxmd.com/read/29618785/tunable-ampere-phase-plate-for-low-dose-imaging-of-biomolecular-complexes
#6
Amir H Tavabi, Marco Beleggia, Vadim Migunov, Alexey Savenko, Ozan Öktem, Rafal E Dunin-Borkowski, Giulio Pozzi
A novel device that can be used as a tunable support-free phase plate for transmission electron microscopy of weakly scattering specimens is described. The device relies on the generation of a controlled phase shift by the magnetic field of a segment of current-carrying wire that is oriented parallel or antiparallel to the electron beam. The validity of the concept is established using both experimental electron holographic measurements and a theoretical model based on Ampere's law. Computer simulations are used to illustrate the resulting contrast enhancement for studies of biological cells and macromolecules...
April 4, 2018: Scientific Reports
https://www.readbyqxmd.com/read/29609300/pulse-energy-dependence-of-refractive-index-change-in-lithium-niobium-silicate-glass-during-femtosecond-laser-direct-writing
#7
Jing Cao, Bertrand Poumellec, François Brisset, Matthieu Lancry
Femtosecond laser-induced refractive index changes in lithium niobium silicate glass were explored at high repetition rate (300 fs, 500 kHz) by polarized light microscopy, full-wave retardation plate, quantitative birefringence microscopy, and digital holographic microscopy. We found three regimes on energy increase. The first one corresponds to isotropic negative refractive index change (for pulse energy ranging 0.4-0.8 μJ/pulse, 0.6 NA, 5μm/s, 650μm focusing depth in the glass). The second one (0.8-1.2 μJ/pulse) corresponds to birefringence with well-defined slow axis orientation...
March 19, 2018: Optics Express
https://www.readbyqxmd.com/read/29553497/lens-free-video-microscopy-for-the-dynamic-and-quantitative-analysis-of-adherent-cell-culture
#8
Cedric Allier, Romaric Vincent, Fabrice Navarro, Mathilde Menneteau, Lamya Ghenim, Xavier Gidrol, Thomas Bordy, Lionel Hervé, Olivier Cioni, Sabine Bardin, Michel Bornens, Yves Usson, Sophie Morales
Here, we demonstrate that lens-free video microscopy enables us to simultaneously capture the kinetics of thousands of cells directly inside the incubator and that it is possible to monitor and quantify single cells along several cell cycles. We describe the full protocol used to monitor and quantify a HeLa cell culture for 2.7 days. First, cell culture acquisition is performed with a lens-free video microscope, and then the data is analyzed following a four-step process: multi-wavelength holographic reconstruction, cell-tracking, cell segmentation and cell division detection algorithms...
February 23, 2018: Journal of Visualized Experiments: JoVE
https://www.readbyqxmd.com/read/29532824/dual-mode-holographic-microscopy-imaging-platform
#9
M Sanz, J A Picazo-Bueno, J García, V Micó
We report on a novel layout capable of dual-mode imaging in real time with different magnifications and resolution capabilities in lensless microscopy. The concept is based on wavelength multiplexing for providing two illuminations with different wavefront curvatures: one is collimated, allowing a large field of view (FOV) with a poor resolution limit, and the other is divergent, to achieve a better resolution limit (micron range) over a small FOV. Moreover, our recently reported concept of MISHELF microscopy [M...
March 13, 2018: Lab on a Chip
https://www.readbyqxmd.com/read/29522021/automatic-cell-identification-and-visualization-using-digital-holographic-microscopy-with-head-mounted-augmented-reality-devices
#10
Timothy O'Connor, Siddharth Rawat, Adam Markman, Bahram Javidi
We propose a compact imaging system that integrates an augmented reality head mounted device with digital holographic microscopy for automated cell identification and visualization. A shearing interferometer is used to produce holograms of biological cells, which are recorded using customized smart glasses containing an external camera. After image acquisition, segmentation is performed to isolate regions of interest containing biological cells in the field-of-view, followed by digital reconstruction of the cells, which is used to generate a three-dimensional (3D) pseudocolor optical path length profile...
March 1, 2018: Applied Optics
https://www.readbyqxmd.com/read/29521987/surface-proximity-effect-in-sedimentation-investigated-by-digital-holographic-microscopy
#11
Mohammad A Charsooghi, Ali-Reza Moradi
In this paper, we measure the proximity effect of a flat wall on the sedimentation of colloidal particles by the use of digital holographic microscopy (DHM). DHM provides quantitative phase contrast and three-dimensional (3D) imaging in arbitrary time scales that are suitable to investigate various phenomena, including dynamic behavior of colloids. 3D information is obtained by post-processing of the recorded digital holograms through the angular spectrum propagation approach for numerical reconstruction. We have measured the trajectory and velocity of spherical colloids in various distances from a flat wall while they sediment under gravity...
March 1, 2018: Applied Optics
https://www.readbyqxmd.com/read/29489800/coded-aperture-structured-illumination-digital-holographic-microscopy-for-superresolution-imaging
#12
Xin-Ji Lai, Han-Yen Tu, Yu-Chih Lin, Chau-Jern Cheng
This paper proposes a coded aperture structured illumination (CASI) technique in digital holographic microscopy (DHM). A CASI wave is generated using two binary phase codes (0° and 120°) for spatial phase shifting. The generated CASI wave then interferes with a reference wave to form a coded Fresnel hologram at a single exposure with compressive sensing (CS) to avoid the temporal phase-shifting process of the structured illumination (SI). The CS algorithm is applied to retrieve the missing data of decoded phase-shifted SI-modulated waves, which are used to separate overlapped spatial frequencies for obtaining a larger spatial frequency coverage to provide superresolution imaging...
March 1, 2018: Optics Letters
https://www.readbyqxmd.com/read/29489765/hilbert-huang-single-shot-spatially-multiplexed-interferometric-microscopy
#13
José Ángel Picazo-Bueno, Maciej Trusiak, Javier García, Krzysztof Patorski, Vicente Micó
Hilbert-Huang single-shot spatially multiplexed interferometric microscopy (H2S2MIM) is presented as the implementation of a robust, fast, and accurate single-shot phase estimation algorithm with an extremely simple, low-cost, and highly stable way to convert a bright field microscope into a holographic one using partially coherent illumination. Altogether, H2S2MIM adds high-speed (video frame rate) quantitative phase imaging capability to a commercially available nonholographic microscope with improved phase reconstruction (coherence noise reduction)...
March 1, 2018: Optics Letters
https://www.readbyqxmd.com/read/29463819/3d-printed-water-soluble-scaffolds-for-rapid-production-of-pdms-micro-fluidic-flow-chambers
#14
Tobias Dahlberg, Tim Stangner, Hanqing Zhang, Krister Wiklund, Petter Lundberg, Ludvig Edman, Magnus Andersson
We report a novel method for fabrication of three-dimensional (3D) biocompatible micro-fluidic flow chambers in polydimethylsiloxane (PDMS) by 3D-printing water-soluble polyvinyl alcohol (PVA) filaments as master scaffolds. The scaffolds are first embedded in the PDMS and later residue-free dissolved in water leaving an inscription of the scaffolds in the hardened PDMS. We demonstrate the strength of our method using a regular, cheap 3D printer, and evaluate the inscription process and the channels micro-fluidic properties using image analysis and digital holographic microscopy...
February 20, 2018: Scientific Reports
https://www.readbyqxmd.com/read/29445207/holographic-traction-force-microscopy
#15
Stanislaw Makarchuk, Nicolas Beyer, Christian Gaiddon, Wilfried Grange, Pascal Hébraud
Traction Force Microscopy (TFM) computes the forces exerted at the surface of an elastic material by measuring induced deformations in volume. It is used to determine the pattern of the adhesion forces exerted by cells or by cellular assemblies grown onto a soft deformable substrate. Typically, colloidal particles are dispersed in the substrate and their displacement is monitored by fluorescent microscopy. As with any other fluorescent techniques, the accuracy in measuring a particule's position is ultimately limited by the number of evaluated fluorescent photons...
February 14, 2018: Scientific Reports
https://www.readbyqxmd.com/read/29444066/dual-wavelength-digital-holographic-phase-and-fluorescence-microscopy-for-an-optical-thickness-encoded-suspension-array
#16
Zhiyuan Shen, Yonghong He, Gong Zhang, Qinghua He, Dongmei Li, Yanhong Ji
A dual-wavelength digital holographic phase and fluorescence microscopy system is demonstrated as the decoding and detection platform of an optical thickness encoded suspension array. The phase imaging path is designed to decode optical thickness encoded microcarriers, and the fluorescence imaging path is used to detect the quantitative information of the bound target analytes. The encoding capacity could be more than 100. The decoding reliability of the phase imaging path is verified by a multiplexed immunoassay experiment...
February 15, 2018: Optics Letters
https://www.readbyqxmd.com/read/29438830/sample-and-substrate-preparation-for-exploring-living-neurons-in-culture-with-quantitative-phase-imaging
#17
REVIEW
Sébastien A Lévesque, Jean-Michel Mugnes, Erik Bélanger, Pierre Marquet
Quantitative phase imaging (QPI) has recently emerged as a powerful new quantitative microscopy technique suitable for the noninvasive exploration of the structure and dynamics of transparent specimens, including living cells in culture. Indeed, the quantitative phase signal (QPS), induced by transparent living cells, can be detected with a nanometric axial sensitivity, and contains a wealth of information about both cell morphology and content. However, QPS is also sensitive to various sources of experimental noise...
February 10, 2018: Methods: a Companion to Methods in Enzymology
https://www.readbyqxmd.com/read/29438336/measurement-of-a-3d-ultrasonic-wavefield-using-pulsed-laser-holographic-microscopy-for-ultrasonic-nondestructive-evaluation
#18
Xing Wang, Guang-Ming Zhang, Hongwei Ma, Yishu Zhang, Doudou Wang
In ultrasonic array imaging, 3D ultrasonic wavefields are normally recorded by an ultrasonic piezo array transducer. Its performance is limited by the configuration and size of the array transducer. In this paper, a method based on digital holographic interferometry is proposed to record the 3D ultrasonic wavefields instead of the array transducer, and the measurement system consisting of a pulsed laser, ultrasonic excitation, and synchronization and control circuit is designed. A consecutive sequence of holograms of ultrasonic wavefields are recorded by the system...
February 13, 2018: Sensors
https://www.readbyqxmd.com/read/29436645/ouabain-suppresses-the-growth-and-migration-abilities-of-glioma-u%C3%A2-87mg-cells-through-inhibiting-the-akt-mtor-signaling-pathway-and-downregulating-the-expression-of-hif%C3%A2-1%C3%AE
#19
Xiao-Sa Yang, Zhong-Wei Xu, Tai-Long Yi, Rui-Cheng Xu, Jie Li, Wen-Bin Zhang, Sai Zhang, Hong-Tao Sun, Ze-Qi Yu, Hao-Xiang Xu, Yue Tu, Shi-Xiang Cheng
Glioma is one of the most malignant forms of brain tumor, and has been of persistent concern due to its high recurrence and mortality rates, and limited therapeutic options. As a cardiac glycoside, ouabain has widespread applications in congestive heart diseases due to its positive cardiac inotropic effect by inhibiting Na+/K+‑ATPase. Previous studies have demonstrated that ouabain has antitumor activity in several types of human tumor, including glioma. However, the exact underlying mechanism remains to be elucidated...
February 12, 2018: Molecular Medicine Reports
https://www.readbyqxmd.com/read/29405583/label-free-quantification-of-the-effects-of-lithium-niobate-polarization-on-cell-adhesion-via-holographic-microscopy
#20
Biagio Mandracchia, Oriella Gennari, Alessia Bramanti, Simonetta Grilli, Pietro Ferraro
The surface of a c-cut ferroelectric crystal at room temperature is characterized by the so-called screening surface charges, able to compensate the charge due to the spontaneous polarization. Recently, these charges inspired the investigation of the interaction affinity of live cells with lithium niobate and lithium tantalate crystals. However, different knowledge gaps still remain that prevent a reasonable application of these materials for biological applications. Here, a label-free holographic total internal reflection (HoloTIR) microscopy is shown; the technique is able to evaluate quantitatively the contact area of live fibroblast cells adhering onto the surface of a ferroelectric lithium niobate crystal...
February 6, 2018: Journal of Biophotonics
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