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https://www.readbyqxmd.com/read/28314083/characterization-of-dormant-and-active-human-cancer-cells-by-quantitative-phase-imaging
#1
Peng Guo, Jing Huang, Marsha A Moses
The switch of tumor cells from a dormant, non-angiogenic phenotype to an active, angiogenic phenotype is a critical step in early cancer progression. To date, relatively little is known about the cellular behaviors of angiogenic and non-angiogenic tumor cell phenotypes. In this study, holographic imaging cytometry, a quantitative phase imaging (QPI) technique was used to continuously and non-invasively analyze, quantify, and compare a panel of fundamental cellular behaviors of angiogenic and non-angiogenic human osteosarcoma cells (KHOS) in a simple and economical way...
March 17, 2017: Cytometry. Part A: the Journal of the International Society for Analytical Cytology
https://www.readbyqxmd.com/read/28306290/mellin-amplitudes-for-supergravity-on-ads_-5-%C3%A3-s-5
#2
Leonardo Rastelli, Xinan Zhou
We revisit the calculation of holographic correlation functions in type-IIB supergravity on AdS_{5}×S^{5}. Results for four-point functions simplify drastically when expressed in Mellin space. We conjecture a compact formula for the four-point functions of one-half Bogomol'nyi-Prasad-Sommerfield single-trace operators of arbitrary weight. Our methods rely on general consistency conditions and eschew detailed knowledge of the supergravity effective action.
March 3, 2017: Physical Review Letters
https://www.readbyqxmd.com/read/28304371/a-scalable-diffraction-based-scanning-3d-colour-video-display-as-demonstrated-by-using-tiled-gratings-and-a-vertical-diffuser
#3
Jia Jia, Jhensi Chen, Jun Yao, Daping Chu
A high quality 3D display requires a high amount of optical information throughput, which needs an appropriate mechanism to distribute information in space uniformly and efficiently. This study proposes a front-viewing system which is capable of managing the required amount of information efficiently from a high bandwidth source and projecting 3D images with a decent size and a large viewing angle at video rate in full colour. It employs variable gratings to support a high bandwidth distribution. This concept is scalable and the system can be made compact in size...
March 17, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28298087/landing-dynamics-of-swimming-bacteria-on-a-polymeric-surface-effect-of-surface-properties
#4
Meng Qi, Xiangjun Gong, Bo Wu, Guangzhao Zhang
Landing of bacteria for adhesion on a surface is a common phenomenon in our life. However, how surface properties involve in this process remains largely unclear. Using digital holographic microscopy (DHM), we have investigated the three-dimensional (3D) motions of flagellate E. coli swimming near polymeric surfaces with different properties in aqueous solution before adhesion. We monitor the bacteria landing dynamics, which shows that the density distribution, the probability and orientation for collisions of the bacteria are determined by their motility but slightly affected by the surface properties...
March 16, 2017: Langmuir: the ACS Journal of Surfaces and Colloids
https://www.readbyqxmd.com/read/28295088/reduction-of-speckle-noise-in-holographic-images-using-spatial-jittering-in-numerical-reconstructions
#5
Mohamed Haouat, Jorge Garcia-Sucerquia, Abdelhamid Kellou, Pascal Picart
This Letter presents an easy, fast, and efficient single-shot method to reduce speckle noise in digital Fresnel holography. In this method, several images from a single hologram are reconstructed by introducing spatial displacements in the Fresnel kernel. Spatial jitters produce images with different speckle positions. Averaging the set of numerically produced images leads to a strong reduction of speckle noise in both amplitude and phase difference images. The experimental results show the suitability of the proposed approach and confirm its applicability to digital holographic interferometry...
March 15, 2017: Optics Letters
https://www.readbyqxmd.com/read/28276489/computational-on-chip-imaging-of-nanoparticles-and-biomolecules-using-ultraviolet-light
#6
Mustafa Ugur Daloglu, Aniruddha Ray, Zoltan Gorocs, Matthew Xiong, Ravinder Malik, Gal Bitan, Euan McLeod, Aydogan Ozcan
Significant progress in characterization of nanoparticles and biomolecules was enabled by the development of advanced imaging equipment with extreme spatial-resolution and sensitivity. To perform some of these analyses outside of well-resourced laboratories, it is necessary to create robust and cost-effective alternatives to existing high-end laboratory-bound imaging and sensing equipment. Towards this aim, we have designed a holographic on-chip microscope operating at an ultraviolet illumination wavelength (UV) of 266 nm...
March 9, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28274495/model-based-magnetization-retrieval-from-holographic-phase-images
#7
Falk Röder, Karin Vogel, Daniel Wolf, Olav Hellwig, Sung Hun Wee, Sebastian Wicht, Bernd Rellinghaus
The phase shift of the electron wave is a useful measure for the projected magnetic flux density of magnetic objects at the nanometer scale. More important for materials science, however, is the knowledge about the magnetization in a magnetic nano-structure. As demonstrated here, a dominating presence of stray fields prohibits a direct interpretation of the phase in terms of magnetization modulus and direction. We therefore present a model-based approach for retrieving the magnetization by considering the projected shape of the nano-structure and assuming a homogeneous magnetization therein...
November 14, 2016: Ultramicroscopy
https://www.readbyqxmd.com/read/28270998/ultra-fast-line-field-low-coherence-holographic-elastography-using-spatial-phase-shifting
#8
Chih-Hao Liu, Alexander Schill, Raksha Raghunathan, Chen Wu, Manmohan Singh, Zhaolong Han, Achuth Nair, Kirill V Larin
Optical coherence elastography (OCE) is an emerging technique for quantifying tissue biomechanical properties. Generally, OCE relies on point-by-point scanning. However, long acquisition times make point-by-point scanning unfeasible for clinical use. Here we demonstrate a noncontact single shot line-field low coherence holography system utilizing an automatic Hilbert transform analysis based on a spatial phase shifting technique. Spatio-temporal maps of elastic wave propagation were acquired with only one air-pulse excitation and used to quantify wave velocity and sample mechanical properties at a line rate of 200 kHz...
February 1, 2017: Biomedical Optics Express
https://www.readbyqxmd.com/read/28270966/label-free-fingerprinting-of-tumor-cells-in-bulk-flow-using-inline-digital-holographic-microscopy
#9
Dhananjay Kumar Singh, Caroline C Ahrens, Wei Li, Siva A Vanapalli
Large-scale and label-free phenotyping of cells holds great promise in medicine, especially in cancer diagnostics and prognosis. Here, we introduce inline digital holography microscopy for volumetric imaging of cells in bulk flow and fingerprinting of flowing tumor cells based on two metrics, in-focus scattered intensity and cell diameter. Using planar distribution of immobilized particles, we identify the optimal recording distance and microscope objective magnification that minimizes the error in measurement of particle position, size and scattered intensity...
February 1, 2017: Biomedical Optics Express
https://www.readbyqxmd.com/read/28264140/quantitative-phase-imaging-for-cell-culture-quality-control
#10
Lena Kastl, Michael Isbach, Dieter Dirksen, Jürgen Schnekenburger, Björn Kemper
The potential of quantitative phase imaging (QPI) with digital holographic microscopy (DHM) for quantification of cell culture quality was explored. Label-free QPI of detached single cells in suspension was performed by Michelson interferometer-based self-interference DHM. Two pancreatic tumor cell lines were chosen as cellular model and analyzed for refractive index, volume, and dry mass under varying culture conditions. Firstly, adequate cell numbers for reliable statistics were identified. Then, to characterize the performance and reproducibility of the method, we compared results from independently repeated measurements and quantified the cellular response to osmolality changes of the cell culture medium...
March 6, 2017: Cytometry. Part A: the Journal of the International Society for Analytical Cytology
https://www.readbyqxmd.com/read/28256551/multimodal-discrimination-of-immune-cells-using-a-combination-of-raman-spectroscopy-and-digital-holographic-microscopy
#11
Naomi McReynolds, Fiona G M Cooke, Mingzhou Chen, Simon J Powis, Kishan Dholakia
The ability to identify and characterise individual cells of the immune system under label-free conditions would be a significant advantage in biomedical and clinical studies where untouched and unmodified cells are required. We present a multi-modal system capable of simultaneously acquiring both single point Raman spectra and digital holographic images of single cells. We use this combined approach to identify and discriminate between immune cell populations CD4+ T cells, B cells and monocytes. We investigate several approaches to interpret the phase images including signal intensity histograms and texture analysis...
March 3, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28251048/detecting-swelling-states-of-red-blood-cells-by-cell-fluid-coupling-spectroscopy
#12
Carla Zensen, Isis E Fernandez, Oliver Eickelberg, Jochen Feldmann, Theobald Lohmüller
Red blood cells are "shaken" with a holographic optical tweezer array. The flow generated around cells due to the periodic optical forcing is measured with an optically trapped "detector" particle located in the cell vicinity. A signal-processing model that describes the cell's physical properties as an analog filter illustrates how cells can be distinguished from each other.
February 2017: Advanced Science (Weinheim, Baden-Wurttemberg, Germany)
https://www.readbyqxmd.com/read/28248380/selection-of-the-tagged-photons-by-off-axis-heterodyne-holography-in-ultrasound-modulated-optical-tomography
#13
M Gross
Ultrasound-modulated optical tomography (UOT) is a technique that images optical contrast deep inside scattering media. Heterodyne holography is a promising tool that is able to detect UOT-tagged photons with high efficiency. In this work, we describe theoretically the detection of the tagged photon in heterodyne holography-based UOT, show how to filter the untagged photon, and discuss the effect of shot noise. The discussion also considers speckle decorrelation. We show that optimal detection sensitivity can be reached, if the frame exposure time of the camera used to perform the holographic detection is on the order of the decorrelation time...
March 1, 2017: Applied Optics
https://www.readbyqxmd.com/read/28248338/spectrum-and-space-resolved-4d-imaging-by-coded-aperture-correlation-holography-coach-with-diffractive-objective-lens
#14
A Vijayakumar, Joseph Rosen
In this Letter, we present an advanced optical configuration of coded aperture correlation holography (COACH) with a diffractive objective lens. Four-dimensional imaging of objects at the three spatial dimensions and with an additional spectral dimension is demonstrated. A hologram of three-dimensional objects illuminated by different wavelengths was recorded by the interference of light diffracted from the objects with the light diffracted from the same objects, but through a random-like coded phase mask (CPM)...
March 1, 2017: Optics Letters
https://www.readbyqxmd.com/read/28248333/superresolved-spatially-multiplexed-interferometric-microscopy
#15
José Ángel Picazo-Bueno, Zeev Zalevsky, Javier García, Vicente Micó
Superresolution capability by angular and time multiplexing is implemented onto a regular microscope. The technique, named superresolved spatially multiplexed interferometric microscopy (S2MIM), follows our previously reported SMIM technique [Opt. Express22, 14929 (2014)OPEXFF1094-408710.1364/OE.22.014929, J. Biomed. Opt.21, 106007 (2016)JBOPFO1083-366810.1117/1.JBO.21.10.106007] improved with superresolved imaging. All together, S2MIM updates a commercially available non-holographic microscope into a superresolved holographic one...
March 1, 2017: Optics Letters
https://www.readbyqxmd.com/read/28244446/probe-reconstruction-for-holographic-x-ray-imaging
#16
Johannes Hagemann, Anna Lena Robisch, Markus Osterhoff, Tim Salditt
In X-ray holographic near-field imaging the resolution and image quality depend sensitively on the beam. Artifacts are often encountered due to the strong focusing required to reach high resolution. Here, two schemes for reconstructing the complex-valued and extended wavefront of X-ray nano-probes, primarily in the planes relevant for imaging (i.e. focus, sample and detection plane), are presented and compared. Firstly, near-field ptychography is used, based on scanning a test pattern laterally as well as longitudinally along the optical axis...
March 1, 2017: Journal of Synchrotron Radiation
https://www.readbyqxmd.com/read/28241657/dynamic-visual-responses-of-accommodation-and-vergence-to-electro-holographic-images
#17
Aya Nozaki, Masaya Mitobe, Fumio Okuyama, Yuji Sakamoto
Electro-holography can display images without inducing fatigue and three-dimensional (3D) sickness, i.e., visual discomfort due to viewing a stereoscopic display. Thus, this technology is expected to be applied to 3D media. However, there are no studies that have shown the agreement between the dynamic responses of accommodation and vergence to the reconstructed images of electro-holography and those to the real targets. This paper describes the measurement results of these responses using a developed system that can simultaneously measure the dynamic responses of accommodation and vergence...
February 20, 2017: Optics Express
https://www.readbyqxmd.com/read/28240818/imaging-of-dense-cell-cultures-by-multiwavelength-lens-free-video-microscopy
#18
C Allier, S Morel, R Vincent, L Ghenim, F Navarro, M Menneteau, T Bordy, L Hervé, O Cioni, X Gidrol, Y Usson, J-M Dinten
They present results for lens-free microscopy for the imaging of dense cell culture. With this aim, they use a multiwavelength LED illumination with well separated wavelengths, together with the implementation of an appropriate holographic reconstruction algorithm. This allows for a fast and efficient reconstruction of the phase image of densely packed cells (up to 700 cells/mm(2) ) over a large field of view of 29.4 mm(2) . Combined with the compactness of the system which fits altogether inside an incubator, lens-free microscopy becomes a unique tool to monitor cell cultures over several days...
February 27, 2017: Cytometry. Part A: the Journal of the International Society for Analytical Cytology
https://www.readbyqxmd.com/read/28220855/extending-calibration-free-force-measurements-to-optically-trapped-rod-shaped-samples
#19
Frederic Català, Ferran Marsà, Mario Montes-Usategui, Arnau Farré, Estela Martín-Badosa
Optical trapping has become an optimal choice for biological research at the microscale due to its non-invasive performance and accessibility for quantitative studies, especially on the forces involved in biological processes. However, reliable force measurements depend on the calibration of the optical traps, which is different for each experiment and hence requires high control of the local variables, especially of the trapped object geometry. Many biological samples have an elongated, rod-like shape, such as chromosomes, intracellular organelles (e...
February 21, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28218254/large-metasurface-aperture-for-millimeter-wave-computational-imaging-at-the-human-scale
#20
J N Gollub, O Yurduseven, K P Trofatter, D Arnitz, M F Imani, T Sleasman, M Boyarsky, A Rose, A Pedross-Engel, H Odabasi, T Zvolensky, G Lipworth, D Brady, D L Marks, M S Reynolds, D R Smith
We demonstrate a low-profile holographic imaging system at millimeter wavelengths based on an aperture composed of frequency-diverse metasurfaces. Utilizing measurements of spatially-diverse field patterns, diffraction-limited images of human-sized subjects are reconstructed. The system is driven by a single microwave source swept over a band of frequencies (17.5-26.5 GHz) and switched between a collection of transmit and receive metasurface panels. High fidelity image reconstruction requires a precise model for each field pattern generated by the aperture, as well as the manner in which the field scatters from objects in the scene...
February 20, 2017: Scientific Reports
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