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Gabriel Popescu - One of the best experts on this subject based on the ideXlab platform.

  • spatial light interference microscopy slim principle and applications to biomedicine
    arXiv: Optics, 2020
    Co-Authors: Xi Chen, Mikhail E Kandel, Gabriel Popescu
    Abstract:

    In this paper, we review spatial light interference microscopy (SLIM), a common-path, Phase-shifting interferometer, built onto a Phase-Contrast Microscope, with white-light illumination. As one of the most sensitive quantitative Phase imaging (QPI) methods, SLIM allows for speckle-free Phase reconstruction with sub-nanometer path-length stability. We first review image formation in QPI, scattering, holography, and microcopy. Then, we outline SLIM imaging from theory to instrumentation. Zernike Phase-Contrast microscopy, Phase retrieval in SLIM, and halo removal algorithms are discussed. Next, we discuss the requirements for operation, with a focus on software developed in-house for SLIM that high-throughput acquisition, whole slide scanning, mosaic tile registration, and imaging with a color camera. Lastly, we review the applications of SLIM in basic science and clinical studies. SLIM can study cell dynamics, cell growth and proliferation, cell migration, and mass transport, etc. In clinical settings, SLIM can assist with cancer studies, reproductive technology, and blood testing, etc. Finally, we review an emerging trend, where SLIM imaging in conjunction with artificial intelligence (AI) brings computational specificity and, in turn, offers new solutions to outstanding challenges in cell biology and pathology.

  • Spatial light interference microscopy (SLIM)
    IEEE Photonic Society 24th Annual Meeting PHO 2011, 2011
    Co-Authors: Zhuo Wang, Huafeng Ding, Larry J Millet, Sakulsuk Unarunotai, John A Rogers, Martha U Gillette, Gabriel Popescu
    Abstract:

    We present spatial light interference microscopy (SLIM) as a new optical microscopy technique, capable of measuring nanoscale structures and dynamics in live cells via interferometry. SLIM combines two classic ideas in light imaging: Zernike's Phase Contrast microscopy, which renders high Contrast intensity images of transparent specimens, and Gabor's holography, where the Phase information from the object is recorded. Thus, SLIM reveals the intrinsic Contrast of cell structures and, in addition, renders quantitative optical path-length maps across the sample. The resulting topographic accuracy is comparable to that of atomic force microscopy, while the acquisition speed is 1,000 times higher. We illustrate the novel insight into cell dynamics via SLIM by experiments on primary cell cultures from the rat brain. SLIM is implemented as an add-on module to an existing Phase Contrast Microscope, which may prove instrumental in impacting the light microscopy field at a large scale.

  • instantaneous spatial light interference microscopy
    Optics Express, 2010
    Co-Authors: Huafeng Ding, Gabriel Popescu
    Abstract:

    We present Instantaneous Spatial Light Interference Microscopy (iSLIM) as a new quantitative Phase method that combines the benefits of white light illumination in Zernike’s Phase Contrast microscopy and Phase stability associated diffraction Phase microscopy. iSLIM is implemented as an add-on module to a commercial Phase Contrast Microscope, and enables new features to quantitative Phase imaging: diminished speckle effects due to white light illumination, multimodal investigation potential due to overlaying with other modalities of the Microscope (e.g. fluorescence, DIC, Phase Contrast), and spectroscopic potential due to the broad band light. We show proof of principle results by multicolor Phase imaging of microsphere and red blood cells, and dynamic imaging of nanoscale cell membrane fluctuations.

Hiroko Iijima - One of the best experts on this subject based on the ideXlab platform.

  • phagocytosis of ultrasound Contrast agent microbubbles by kupffer cells
    Ultrasound in Medicine and Biology, 2007
    Co-Authors: Kyosuke Yanagisawa, Fuminori Moriyasu, Takeo Miyahara, Miyata Yuki, Hiroko Iijima
    Abstract:

    Delayed parenchymal Phase images of the liver more than 5 min after IV injection of ultrasound Contrast agents are thought to be related to the phagocytosis of Contrast agent microbubbles by macrophages. In this study, we examined whether liver-specific macrophages, Kupffer cells, phagocytosed the microbubbles and whether their elimination affected the delayed parenchymal images of the liver. Phase-Contrast Microscope observations showed that Kupffer cells phagocytosed various Contrast agents in vitro. Among the Contrast agents used, 99% of Sonazoid and Optison, and 47% of Levovist were phagocytosed, whereas only 7.3% of SonoVue and 0% of Imavist were phagocytosed. Elimination of Kupffer cells in vivo by gadolinium chloride (GdCl(3)) resulted in decreased intensity of the delayed parenchymal images with Sonazoid and Levovist, while SonoVue showed no changes compared with control. Our findings suggested that Kupffer cells phagocytosed Contrast agents and they were responsible for the delayed images of Contrast ultrasound in the liver.

  • phagocytosis of ultrasound Contrast agent microbubbles by kupffer cells
    Ultrasound in Medicine and Biology, 2007
    Co-Authors: Kyosuke Yanagisawa, Fuminori Moriyasu, Takeo Miyahara, Miyata Yuki, Hiroko Iijima
    Abstract:

    Delayed parenchymal Phase images of the liver more than 5 min after IV injection of ultrasound Contrast agents are thought to be related to the phagocytosis of Contrast agent microbubbles by macrophages. In this study, we examined whether liver-specific macrophages, Kupffer cells, phagocytosed the microbubbles and whether their elimination affected the delayed parenchymal images of the liver. Phase-Contrast Microscope observations showed that Kupffer cells phagocytosed various Contrast agents in vitro. Among the Contrast agents used, 99% of Sonazoid TM and Optison TM , and 47% of Levovist TM were phagocytosed, whereas only 7.3% of SonoVue TM and 0% of Imavist TM were phagocytosed. Elimination of Kupffer cells in vivo by gadolinium chloride (GdCl3) resulted in decreased intensity of the delayed parenchymal images with Sonazoid TM and Levovist TM , while SonoVue TM showed no changes compared with control. Our findings suggested that Kupffer cells phagocytosed Contrast agents and they were responsible for the delayed images of Contrast ultrasound in the liver. (E-mail: moriyasu@tokyo-med.ac.jp) © 2007 World Federation for Ultrasound in Medicine & Biology.

Satoshi Kawata - One of the best experts on this subject based on the ideXlab platform.

  • Nondestructive readout of a three-dimensional photochromic optical memory with a near-infrared differential Phase-Contrast Microscope.
    Optics letters, 1997
    Co-Authors: A. Toriumi, J. M. Herrmann, Satoshi Kawata
    Abstract:

    A three-dimensional (3D) rewritable optical memory using photochromic material is described for high-density memory. The bits are recorded in a 3D volume of photochromic material. A transformation of the photochromic molecule between two isomers with different absorption spectra can be stimulated by irradiation with appropriate wavelengths. We show that a nondestructive readout of photochromic memory is possible by use of a small difference in the refractive index of the photochromic isomers in the near-IR range. For this purpose a near-IR laser-scan differential Phase-Contrast Microscope is used. Experimental results of 3D recording and nondestructive reading are presented.

  • three dimensional optical bit memory recording and reading with a photorefractive crystal analysis and experiment
    Applied Optics, 1996
    Co-Authors: Hisahiko Ueki, Yoshimasa Kawata, Satoshi Kawata
    Abstract:

    We analyze the three-dimensional refractive-index distribution that is induced locally when a laser beam is focused onto a very small region in a photorefractive crystal. The formation of the index distribution is deduced from the temporal behavior of the electron density distribution in the crystal under non-steady-state conditions. The density distribution is computed by the use of a set of the recurrence relations that was derived from Kukhtarev’s equations, which describe the transport of electrons in time. In particular, we calculated the index distribution formed in Fe-doped LiNbO3 crystals. To verify the validity of our analysis, we read, by using a Phase-Contrast Microscope, refractive-index dots that were recorded in Fe-doped LiNbO3 crystals. Agood agreement was obtained between experimental results and the calculated Phase-Contrast images when the characteristics of the imaging system are taken into account. We also found that the induced index change is largest when the c axis of the LiNbO3 crystal is oriented parallel to the polarization direction of the reading beam. Under this optimal condition, we succeeded in recording up to 10 layers of readable data in a LiNbO3 crystal.

  • differential Phase Contrast Microscope with a split detector for the readout system of a multilayered optical memory
    Applied Optics, 1996
    Co-Authors: Yoshimasa Kawata, R Juskaitis, Tomokazu Tanaka, Tony Wilson, Satoshi Kawata
    Abstract:

    A transmission differential Phase-Contrast Microscope with a split detector is used as a readout system for a multilayered three-dimensional optical memory. The system is applicable to data recorded as refractive-index changes. The system is compact and easy to use. The three-dimensional optical transfer function for the system is derived. This shows that the spatial bandwidth of the system is the same as that of a conventional Microscope with incoherent illumination but with much improved Contrast. Six layers of information are recorded in a photopolymer and are read out with little cross talk and high Contrast.

  • three dimensional optical memory with a photorefractive crystal
    Applied Optics, 1995
    Co-Authors: Yoshimasa Kawata, Hisahiko Ueki, Yoshimi Hashimoto, Satoshi Kawata
    Abstract:

    We propose a three-dimensional optical-memory device in which refractive dot data are recorded directly into a photorefractive crystal. To record a single bit of datum, one focuses a laser beam with an objective lens onto a specific spot in a crystal, thereby changing its refractive index locally as a result of photorefraction. To record in three dimensions, one keeps the objective lens stationary while the crystal is translated. The beam-spot intensity is modulated with a beam shutter according to the logic state of the data point. The recorded data points are read with a Phase–Contrast Microscope objective lens. We present experimental results of three-dimensional recording and reading with a LiNbO3 crystal. The distribution of the refractive index formed by a focused beam is also analyzed with the charge-transport model.

Takuro Ideguchi - One of the best experts on this subject based on the ideXlab platform.

  • Molecular Contrast on Phase-Contrast Microscope
    Scientific Reports, 2019
    Co-Authors: Keiichiro Toda, Miu Tamamitsu, Yu Nagashima, Ryoichi Horisaki, Takuro Ideguchi
    Abstract:

    An optical Microscope enables image-based findings and diagnosis on microscopic targets, which is indispensable in many scientific, industrial and medical settings. A standard benchtop Microscope platform, equipped with e.g., bright-field and Phase-Contrast modes, is of importance and convenience for various users because the wide-field and label-free properties allow for morphological imaging without the need for specific sample preparation. However, these Microscopes never have capability of acquiring molecular Contrast in a label-free manner. Here, we develop a simple add-on optical unit, comprising of an amplitude-modulated mid-infrared semiconductor laser, that is attached to a standard Microscope platform to deliver the additional molecular Contrast of the specimen on top of its conventional microscopic image, based on the principle of photothermal effect. We attach this unit, termed molecular-Contrast unit, to a standard Phase-Contrast Microscope, and demonstrate high-speed label-free molecular-Contrast Phase-Contrast imaging of silica-polystyrene microbeads mixture and molecular-vibrational spectroscopic imaging of HeLa cells. Our simple molecular-Contrast unit can empower existing standard Microscopes and deliver a convenient accessibility to the molecular world.

  • Phase-Contrast Microscope with Molecular Contrast
    2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO Europe-EQEC), 2019
    Co-Authors: Keiichiro Toda, Miu Tamamitsu, Ryoichi Horisaki, Takuro Ideguchi
    Abstract:

    Acquisition of molecular information is useful in various aspects of science, industry and medicine. Fluorescence imaging is the most widely used molecular imaging technique in biological fields, but is accompanied by chemical alteration of and photodamage to the sample due to the use of fluorescent labelling agents. Alternatively, label-free molecular-vibrational imaging methods, such as mid-infrared (MIR) absorption imaging and spontaneous/coherent Raman scattering (RS) imaging [1], suffer from low spatial resolution, low sensitivity (low imaging speed), high photodamage and/or the need of custom-made complicated optical systems.

Huafeng Ding - One of the best experts on this subject based on the ideXlab platform.

  • Spatial light interference microscopy (SLIM)
    IEEE Photonic Society 24th Annual Meeting PHO 2011, 2011
    Co-Authors: Zhuo Wang, Huafeng Ding, Larry J Millet, Sakulsuk Unarunotai, John A Rogers, Martha U Gillette, Gabriel Popescu
    Abstract:

    We present spatial light interference microscopy (SLIM) as a new optical microscopy technique, capable of measuring nanoscale structures and dynamics in live cells via interferometry. SLIM combines two classic ideas in light imaging: Zernike's Phase Contrast microscopy, which renders high Contrast intensity images of transparent specimens, and Gabor's holography, where the Phase information from the object is recorded. Thus, SLIM reveals the intrinsic Contrast of cell structures and, in addition, renders quantitative optical path-length maps across the sample. The resulting topographic accuracy is comparable to that of atomic force microscopy, while the acquisition speed is 1,000 times higher. We illustrate the novel insight into cell dynamics via SLIM by experiments on primary cell cultures from the rat brain. SLIM is implemented as an add-on module to an existing Phase Contrast Microscope, which may prove instrumental in impacting the light microscopy field at a large scale.

  • instantaneous spatial light interference microscopy
    Optics Express, 2010
    Co-Authors: Huafeng Ding, Gabriel Popescu
    Abstract:

    We present Instantaneous Spatial Light Interference Microscopy (iSLIM) as a new quantitative Phase method that combines the benefits of white light illumination in Zernike’s Phase Contrast microscopy and Phase stability associated diffraction Phase microscopy. iSLIM is implemented as an add-on module to a commercial Phase Contrast Microscope, and enables new features to quantitative Phase imaging: diminished speckle effects due to white light illumination, multimodal investigation potential due to overlaying with other modalities of the Microscope (e.g. fluorescence, DIC, Phase Contrast), and spectroscopic potential due to the broad band light. We show proof of principle results by multicolor Phase imaging of microsphere and red blood cells, and dynamic imaging of nanoscale cell membrane fluctuations.