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Sample records for polarized light microscope

  1. Measurements of polarization-dependent angle-resolved light scattering from individual microscopic samples using Fourier transform light scattering

    Science.gov (United States)

    Jung, JaeHwang; Kim, Jinhyung; Seo, Min-Kyo; Park, YongKeun

    2018-03-01

    We present a method to measure the vector-field light scattering of individual microscopic objects. The polarization-dependent optical field images are measured with quantitative phase imaging at the sample plane, and then numerically propagated to the far-field plane. This approach allows the two-dimensional polarization-dependent angle-resolved light scattered patterns from individual object to be obtained with high precision and sensitivity. Using this method, we present the measurements of the polarization-dependent light scattering of a liquid crystal droplet and individual silver nanowires over scattering angles of 50{\\deg}. In addition, the spectroscopic extension of the polarization-dependent angle-resolved light scattering is demonstrated using wavelength-scanning illumination.

  2. Kaleidoscope of oral artifacts: A vivid picture through light and polarizing microscope.

    Science.gov (United States)

    Kardam, Priyanka; Jain, Kanu; Mehendiratta, Monica; Mathias, Yulia

    2016-01-01

    This study is based on finding of an inexplicable artifact that was seen in the tissue received as periapical granuloma. To observe the histological appearance of different commonly implanted food particles and easily incorporated substances from a laboratory in the oral biopsy tissues. Various food particles such as wheat chapatti, beans, peas, pulses, and coriander leaves and substances such as a suture, cotton, and paper that can easily gain entry during biopsy and histotechnical procedures were intentionally introduced in the tissue specimens of a uterus from outside. Both light and polarizing microscopes were utilized to view them. Different food particles and substances gave different appearances that could lead to misdiagnosis. Some of these also exhibited positive birefringence under the polarizing microscope. Knowledge and familiarity with probable foreign substances which can appear in tissues may help prevent misdiagnosis or erroneous diagnosis of biopsy specimens.

  3. Polarized light and scanning electron microscopic investigation of enamel hypoplasia in primary teeth.

    Science.gov (United States)

    Sabel, Nina; Klingberg, Gunilla; Dietz, Wolfram; Nietzsche, Sandor; Norén, Jörgen G

    2010-01-01

    Enamel hypoplasia is a developmental disturbance during enamel formation, defined as a macroscopic defect in the enamel, with a reduction of the enamel thickness with rounded, smooth borders. Information on the microstructural level is still limited, therefore further studies are of importance to better understand the mechanisms behind enamel hypoplasia. To study enamel hypoplasia in primary teeth by means of polarized light microscopy and scanning electron microscopy. Nineteen primary teeth with enamel hypoplasia were examined in a polarized light microscope and in a scanning electron microscope. The cervical and incisal borders of the enamel hypoplasia had a rounded appearance, as the prisms in the rounded cervical area of the hypoplasia were bent. The rounded borders had a normal surface structure whereas the base of the defects appeared rough and porous. Morphological findings in this study indicate that the aetiological factor has a short duration and affects only certain ameloblasts. The bottom of the enamel hypoplasia is porous and constitutes possible pathways for bacteria into the dentin.

  4. Polarized Light Corridor Demonstrations.

    Science.gov (United States)

    Davies, G. R.

    1990-01-01

    Eleven demonstrations of light polarization are presented. Each includes a brief description of the apparatus and the effect demonstrated. Illustrated are strain patterns, reflection, scattering, the Faraday Effect, interference, double refraction, the polarizing microscope, and optical activity. (CW)

  5. Quantitative characterization of the carbon/carbon composites components based on video of polarized light microscope.

    Science.gov (United States)

    Li, Yixian; Qi, Lehua; Song, Yongshan; Chao, Xujiang

    2017-06-01

    The components of carbon/carbon (C/C) composites have significant influence on the thermal and mechanical properties, so a quantitative characterization of component is necessary to study the microstructure of C/C composites, and further to improve the macroscopic properties of C/C composites. Considering the extinction crosses of the pyrocarbon matrix have significant moving features, the polarized light microscope (PLM) video is used to characterize C/C composites quantitatively because it contains sufficiently dynamic and structure information. Then the optical flow method is introduced to compute the optical flow field between the adjacent frames, and segment the components of C/C composites from PLM image by image processing. Meanwhile the matrix with different textures is re-segmented by the length difference of motion vectors, and then the component fraction of each component and extinction angle of pyrocarbon matrix are calculated directly. Finally, the C/C composites are successfully characterized from three aspects of carbon fiber, pyrocarbon, and pores by a series of image processing operators based on PLM video, and the errors of component fractions are less than 15%. © 2017 Wiley Periodicals, Inc.

  6. Polarized light microscopic analysis of bone formation after inhibition of cyclooxygenase 1 and 2.

    Science.gov (United States)

    Retamoso, Luciana Borges; Montagner, Francisco; Camargo, Elisa Souza; Vitral, Roberto Willer Farinazzo; Tanaka, Orlando Motohiro

    2010-02-01

    Potassium diclofenac is a potent nonsteroidal anti-inflammatory drug (NSAID) and COX isoforms (COX-1 and COX-2) inhibitor. Quantitative analysis of birefringence with polarized light microscopy is a useful method to investigate the macromolecular orientation and organization of collagen fibers in connective tissues. The aim of this research was to analyze the collagen structure and maturation in bone formed after potassium diclofenac administration, during first molar orthodontic movement. Sixty Wistar rats were divided in two equal groups (N = 30): control (C) and potassium diclofenac (PD). The animals in Group C received 0.9% saline solution and the PD group received potassium diclofenac Cataflam (5 mg/kg). Animals were sacrificed 3, 7, or 14 days after a NiTi unilateral closed-coil spring was stretched between the upper right first molar and the incisors. The first molar area was fixed, decalcified, and histologically processed using picrosirius pigment. The collagen birefringence of bone turnover was analyzed by phase retardation. Two-way ANOVA and Tukey's test showed that optical retardation was influenced by time and treatment. There was increase in the collagen organization over time. On the third day, the C group showed better collagen organization than the PD group. Potassium diclofenac interfered in collagen maturation, reducing fibril organization in the initial phase of orthodontic movement. 2009 Wiley-Liss, Inc.

  7. Imaging differential polarization microscope with electronic readout

    International Nuclear Information System (INIS)

    Mickols, W.; Tinoco, I.; Katz, J.E.; Maestre, M.F.; Bustamante, C.

    1985-01-01

    A differential polarization microscope forms two images: one of the transmitted intensity and the other due to the change in intensity between images formed when different polarizations of light are used. The interpretation of these images for linear dichroism and circular dichroism are described. The design constraints on the data acquisition systems and the polarization modulation are described. The advantage of imaging several biological systems which contain optically anisotropic structures are described

  8. Quantitative characterization of carbon/carbon composites matrix texture based on image analysis using polarized light microscope.

    Science.gov (United States)

    Li, Yixian; Qi, Lehua; Song, Yongshan; Hou, Xianghui; Li, Hejun

    2015-10-01

    A quantitative characteristic method was proposed for characterizing the matrix texture of carbon/carbon(C/C) composites, which determined the mechanical and physical properties of C/C composites. Based on the cloud theory that was commonly used for uncertain reasoning and the transformation between quantitative and qualitative characterization, so the relationship between the extinction angle and texture types was built by the cloud models for describing the texture of microstructure, moreover, linguistic controllers were established to analyze the matrix texture in accordance with the features of the polarized light microscope (PLM) image. On this basis, the extinction angle could be calculated from the PLM image of the C/C composites. In contrast to the results of measurement, the errors between calculative values and measured values were maintained 1-2° in basically. Meanwhile, the PLM image of C/C composites was segmented by the component, in particular, the matrix with mixed textures was further segmented by the difference of texture. It means that the quantitative characterization of C/C composites matrix based on single PLM image has been realized. © 2015 Wiley Periodicals, Inc.

  9. Light microscope alignment methods.

    Science.gov (United States)

    Bagnell, Robert

    2014-01-01

    Instructions for proper alignment for each of the most common wide field light microscopy contrast techniques are presented: bright field, polarization, dark field, phase contrast, differential interference contrast, and fluorescence. These are then followed by methods on photomicrography, measurement, and cleaning. An extensive set of Notes provides practical tips for each of these methods.

  10. Polarized Light Microscopy

    Science.gov (United States)

    Frandsen, Athela F.

    2016-01-01

    Polarized light microscopy (PLM) is a technique which employs the use of polarizing filters to obtain substantial optical property information about the material which is being observed. This information can be combined with other microscopy techniques to confirm or elucidate the identity of an unknown material, determine whether a particular contaminant is present (as with asbestos analysis), or to provide important information that can be used to refine a manufacturing or chemical process. PLM was the major microscopy technique in use for identification of materials for nearly a century since its introduction in 1834 by William Fox Talbot, as other techniques such as SEM (Scanning Electron Microscopy), FTIR (Fourier Transform Infrared spectroscopy), XPD (X-ray Powder Diffraction), and TEM (Transmission Electron Microscopy) had not yet been developed. Today, it is still the only technique approved by the Environmental Protection Agency (EPA) for asbestos analysis, and is often the technique first applied for identification of unknown materials. PLM uses different configurations in order to determine different material properties. With each configuration additional clues can be gathered, leading to a conclusion of material identity. With no polarizing filter, the microscope can be used just as a stereo optical microscope, and view qualities such as morphology, size, and number of phases. With a single polarizing filter (single polars), additional properties can be established, such as pleochroism, individual refractive indices, and dispersion staining. With two polarizing filters (crossed polars), even more can be deduced: isotropy vs. anisotropy, extinction angle, birefringence/degree of birefringence, sign of elongation, and anomalous polarization colors, among others. With the use of PLM many of these properties can be determined in a matter of seconds, even for those who are not highly trained. McCrone, a leader in the field of polarized light microscopy, often

  11. Nanoparticle Imaging with Polarization Interferometric Nonlinear Confocal Microscope

    OpenAIRE

    Fujita, Kohei; Egami, Chikara

    2014-01-01

    Polarization interferometric nonlinear confocal microscope has been developed for single nanoparticle analysis of drug delivery system (DDS). The microscope is a system based on a low cost and low power continuous wave (CW) laser light source. Also, the microscope observed shape anisotropy of the 200 nm diameter nanoparticle. According to nanoparticle imaging and CTF (contrast transfer function) curve observation of the microscope, three-dimensional resolution of the microscope measured up to...

  12. Living Cells and Dynamic Molecules Observed with the Polarized Light Microscope: the Legacy of Shinya Inoué.

    Science.gov (United States)

    Tani, Tomomi; Shribak, Michael; Oldenbourg, Rudolf

    2016-08-01

    In 1948, Shinya Inoué arrived in the United States for graduate studies at Princeton. A year later he came to Woods Hole, starting a long tradition of summer research at the Marine Biological Laboratory (MBL), which quickly became Inoué's scientific home. Primed by his Japanese mentor, Katsuma Dan, Inoué followed Dan's mantra to work with healthy, living cells, on a fundamental problem (mitosis), with a unique tool set that he refined for precise and quantitative observations (polarized light microscopy), and a fresh and brilliant mind that was unafraid of challenging current dogma. Building on this potent combination, Inoué contributed landmark observations and concepts in cell biology, including the notion that there are dynamic, fine structures inside living cells, in which molecular assemblies such as mitotic spindle fibers exist in delicate equilibrium with their molecular building blocks suspended in the cytoplasm. In the late 1970s and 1980s, Inoué and others at the MBL were instrumental in conceiving video microscopy, a groundbreaking technique which married light microscopy and electronic imaging, ushering in a revolution in how we know and what we know about living cells and the molecular mechanisms of life. Here, we recount some of Inoué's accomplishments and describe how his legacy has shaped current activities in polarized light imaging at the MBL. © 2016 Marine Biological Laboratory.

  13. The Light Microscope.

    Science.gov (United States)

    Baker, W. L.

    1995-01-01

    Describes the function of the various parts of the microscope and their integration in the formation of an optical image. Presents a procedure for setting up a microscope to obtain maximum resolution and contrast for each objective lens at all magnifications. (JRH)

  14. Characterization of process-induced damage in Cu/low-k interconnect structure by microscopic infrared spectroscopy with polarized infrared light

    Energy Technology Data Exchange (ETDEWEB)

    Seki, Hirofumi, E-mail: Hirofumi-Seki@trc.toray.co.jp; Hashimoto, Hideki [Toray Research Center, Inc., 3-3-7 Sonoyama, Otsu, Shiga 520-8567 (Japan); Ozaki, Yukihiro [Department of Chemistry, School of Science and Technology, Kwansei Gakuin University, 2-1, Gakuen, Sanda, Hyogo 669-1337 (Japan)

    2016-09-07

    Microscopic Fourier-transform infrared (FT-IR) spectra are measured for a Cu/low-k interconnect structure using polarized IR light for different widths of low-k spaces and Cu lines, and for different heights of Cu lines, on Si substrates. Although the widths of the Cu line and the low-k space are 70 nm each, considerably smaller than the wavelength of the IR light, the FT-IR spectra of the low-k film were obtained for the Cu/low-k interconnect structure. A suitable method was established for measuring the process-induced damage in a low-k film that was not detected by the TEM-EELS (Transmission Electron Microscope-Electron Energy-Loss Spectroscopy) using microscopic IR polarized light. Based on the IR results, it was presumed that the FT-IR spectra mainly reflect the structural changes in the sidewalls of the low-k films for Cu/low-k interconnect structures, and the mechanism of generating process-induced damage involves the generation of Si-OH groups in the low-k film when the Si-CH{sub 3} bonds break during the fabrication processes. The Si-OH groups attract moisture and the OH peak intensity increases. It was concluded that the increase in the OH groups in the low-k film is a sensitive indicator of low-k damage. We achieved the characterization of the process-induced damage that was not detected by the TEM-EELS and speculated that the proposed method is applicable to interconnects with line and space widths of 70 nm/70 nm and on shorter scales of leading edge devices. The location of process-induced damage and its mechanism for the Cu/low-k interconnect structure were revealed via the measurement method.

  15. Modulus design multiwavelength polarization microscope for transmission Mueller matrix imaging.

    Science.gov (United States)

    Zhou, Jialing; He, Honghui; Chen, Zhenhua; Wang, Ye; Ma, Hui

    2018-01-01

    We have developed a polarization microscope based on a commercial transmission microscope. We replace the halogen light source by a collimated LED light source module of six different colors. We use achromatic polarized optical elements that can cover the six different wavelength ranges in the polarization state generator (PSG) and polarization state analyzer (PSA) modules. The dual-rotating wave plate method is used to measure the Mueller matrix of samples, which requires the simultaneous rotation of the two quarter-wave plates in both PSG and PSA at certain angular steps. A scientific CCD detector is used as the image receiving module. A LabView-based software is developed to control the rotation angels of the wave plates and the exposure time of the detector to allow the system to run fully automatically in preprogrammed schedules. Standard samples, such as air, polarizers, and quarter-wave plates, are used to calibrate the intrinsic Mueller matrix of optical components, such as the objectives, using the eigenvalue calibration method. Errors due to the images walk-off in the PSA are studied. Errors in the Mueller matrices are below 0.01 using air and polarizer as standard samples. Data analysis based on Mueller matrix transformation and Mueller matrix polarization decomposition is used to demonstrate the potential application of this microscope in pathological diagnosis. (2018) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE).

  16. Modulus design multiwavelength polarization microscope for transmission Mueller matrix imaging

    Science.gov (United States)

    Zhou, Jialing; He, Honghui; Chen, Zhenhua; Wang, Ye; Ma, Hui

    2018-01-01

    We have developed a polarization microscope based on a commercial transmission microscope. We replace the halogen light source by a collimated LED light source module of six different colors. We use achromatic polarized optical elements that can cover the six different wavelength ranges in the polarization state generator (PSG) and polarization state analyzer (PSA) modules. The dual-rotating wave plate method is used to measure the Mueller matrix of samples, which requires the simultaneous rotation of the two quarter-wave plates in both PSG and PSA at certain angular steps. A scientific CCD detector is used as the image receiving module. A LabView-based software is developed to control the rotation angels of the wave plates and the exposure time of the detector to allow the system to run fully automatically in preprogrammed schedules. Standard samples, such as air, polarizers, and quarter-wave plates, are used to calibrate the intrinsic Mueller matrix of optical components, such as the objectives, using the eigenvalue calibration method. Errors due to the images walk-off in the PSA are studied. Errors in the Mueller matrices are below 0.01 using air and polarizer as standard samples. Data analysis based on Mueller matrix transformation and Mueller matrix polarization decomposition is used to demonstrate the potential application of this microscope in pathological diagnosis.

  17. Shear Brillouin light scattering microscope.

    Science.gov (United States)

    Kim, Moonseok; Besner, Sebastien; Ramier, Antoine; Kwok, Sheldon J J; An, Jeesoo; Scarcelli, Giuliano; Yun, Seok Hyun

    2016-01-11

    Brillouin spectroscopy has been used to characterize shear acoustic phonons in materials. However, conventional instruments had slow acquisition times over 10 min per 1 mW of input optical power, and they required two objective lenses to form a 90° scattering geometry necessary for polarization coupling by shear phonons. Here, we demonstrate a confocal Brillouin microscope capable of detecting both shear and longitudinal phonons with improved speeds and with a single objective lens. Brillouin scattering spectra were measured from polycarbonate, fused quartz, and borosilicate in 1-10 s at an optical power level of 10 mW. The elastic constants, phonon mean free path and the ratio of the Pockels coefficients were determined at microscopic resolution.

  18. Malaria Diagnosis Using a Mobile Phone Polarized Microscope

    Science.gov (United States)

    Pirnstill, Casey W.; Coté, Gerard L.

    2015-08-01

    Malaria remains a major global health burden, and new methods for low-cost, high-sensitivity, diagnosis are essential, particularly in remote areas with low-resource around the world. In this paper, a cost effective, optical cell-phone based transmission polarized light microscope system is presented for imaging the malaria pigment known as hemozoin. It can be difficult to determine the presence of the pigment from background and other artifacts, even for skilled microscopy technicians. The pigment is much easier to observe using polarized light microscopy. However, implementation of polarized light microscopy lacks widespread adoption because the existing commercial devices have complicated designs, require sophisticated maintenance, tend to be bulky, can be expensive, and would require re-training for existing microscopy technicians. To this end, a high fidelity and high optical resolution cell-phone based polarized light microscopy system is presented which is comparable to larger bench-top polarized microscopy systems but at much lower cost and complexity. The detection of malaria in fixed and stained blood smears is presented using both, a conventional polarized microscope and our cell-phone based system. The cell-phone based polarimetric microscopy design shows the potential to have both the resolution and specificity to detect malaria in a low-cost, easy-to-use, modular platform.

  19. Microscopic structure for light nuclei

    International Nuclear Information System (INIS)

    Sharma, V.K.

    1995-01-01

    The microscopic structure for light nuclei e.g. 4 He, 7 Li and 8 Be is considered in the frame work of the generator coordinate method (GCM). The physical interpretation of our GCM is also discussed. The GC amplitudes are used to calculate the various properties like charge and magnetic RMS radii, form factors, electromagnetic moments, astrophysical S-factor, Bremsstrahlung weighted cross sections, relative wavefunctions and vertex functions etc. All the calculated quantities agree well with the values determined experimentally. (author). 30 refs., 10 figs., 2 tabs

  20. Polarized differential-phase laser scanning microscope

    International Nuclear Information System (INIS)

    Chou Chien; Lyu, C.-W.; Peng, L.-C.

    2001-01-01

    A polarized differential-phase laser scanning microscope, which combines a polarized optical heterodyne Mach-Zehnder interferometer and a differential amplifier to scan the topographic image of a surface, is proposed. In the experiment the differential amplifier, which acts as a PM-AM converter, in the experiment, converting phase modulation (PM) into amplitude modulation (AM). Then a novel, to our knowledge, phase demodulator was proposed and implemented for the differential-phase laser scanning microscope. An optical grating (1800 lp/mm) was imaged. The lateral and the depth resolutions of the imaging system were 0.5 μm and 1 nm, respectively. The detection accuracy, which was limited by the reflectivity variation of the test surface, is discussed

  1. Create a Polarized Light Show.

    Science.gov (United States)

    Conrad, William H.

    1992-01-01

    Presents a lesson that introduces students to polarized light using a problem-solving approach. After illustrating the concept using a slinky and poster board with a vertical slot, students solve the problem of creating a polarized light show using Polya's problem-solving methods. (MDH)

  2. POLARIZED LIGHT IN PHYSIOTHERAPY

    Directory of Open Access Journals (Sweden)

    L. D. Tondiy

    2015-12-01

    Full Text Available The data on polarized light (PS - a new promising treatment, rehabilitation and prevention, which took its deserved place among the known therapeutic physical factors and may even compete with laser radiation of low and LED therapy. It is reflected the significant contribution of domestic scientists in the study of aircraft action on the body, its introduction in the treatment, rehabilitation and prevention of grippe, ARI. These action's mechanisms of the aircraft on the electro-physiological processes in the body that have the leading role in the regulation of its life. The new moment in the study of aircraft on the body is the evidence of its positive impact on the mechanisms of self body - its different units: the disease's banning - a revitalization of the stress-protective, stress-limiting system antioxidial, detoxification and other protection systems, the formation by the body antiviral and antimicrobial specific substances (interferon and lysozyme, activation of the immune system, phagocytosis, protective functions of skin. The protective and mobilizing role of the second link is studied: which is triggered in case of occurrence of disease or preexisting diseases: PL mobilized processes of restitution, reparations, compensation, immunity and microcirculation. The authors studied the possibility of aircraft's using to enhance performance, reduce side effects of physical factors, which are often used in the treatment (electric methods, treatment by sound, fresh and mineral water, etc..

  3. Polarimetry with azimuthally polarized light

    Science.gov (United States)

    de Sande, Juan Carlos González; Piquero, Gemma; Santarsiero, Massimo

    2018-03-01

    Nonuniformly polarized light can be used for Mueller polarimetry of homogeneous linear samples. In this work, a set up based on using azimuthally polarized input light and a modified commercial light polarimeter is proposed and developed. With this set up, a Mueller submatrix of a sample can be obtained by measuring the Stokes parameters at only three different positions across the output beam section. Symmetry constraints for linear deterministic samples allow the complete Mueller matrix to be deduced for this kind of specimens. The experimental results obtained for phase plates and for a linear polarizer confirm the validity of the proposed method.

  4. Major Components of the Light Microscope

    OpenAIRE

    Centonze Frohlich, Victoria

    2008-01-01

    The light microscope is a basic tool for the cell biologist, who should have a thorough understanding of how it works, how it should be aligned for different applications, and how it should be maintained as required to obtain maximum image-forming capacity and resolution. The components of the microscope are described in detail here.

  5. Major components of the light microscope.

    Science.gov (United States)

    Centonze Frohlich, Victoria

    2008-07-30

    The light microscope is a basic tool for the cell biologist, who should have a thorough understanding of how it works, how it should be aligned for different applications, and how it should be maintained as required to obtain maximum image-forming capacity and resolution. The components of the microscope are described in detail here.

  6. Quasi interference of perpendicularly polarized guided modes observed with a photon scanning tunneling microscope

    NARCIS (Netherlands)

    Balistreri, M.L.M.; Driessen, A.; Korterik, Jeroen P.; Kuipers, L.; van Hulst, N.F.

    2000-01-01

    The simultaneous detection of TE- as well as TM-polarized light with a photon scanning tunneling microscope leads to a quasi- interference pattern of these mutually perpendicular polarized fields. This interference pattern has been observed in the optical field distribution as a function of both

  7. Characteristics of volume polarization holography with linear polarization light

    Science.gov (United States)

    Zang, Jinliang; Wu, An'an; Liu, Ying; Wang, Jue; Lin, Xiao; Tan, Xiaodi; Shimura, Tsutomu; Kuroda, Kazuo

    2015-10-01

    Volume polarization holographic recording in phenanthrenequinone-doped poly(methyl methacrylate) (PQ-PMMA) photopolymer with linear polarized light is obtained. The characteristics of the volume polarization hologram are experimentally investigated. It is found that beyond the paraxial approximation the polarization states of the holographic reconstruction light are generally different from the signal light. Based on vector wave theoretical analyses and material properties, the special exposure condition for correctly holographic reconstruction is obtained and experimentally demonstrated.

  8. Microscope spectrometer for light scattering investigations.

    Science.gov (United States)

    Barbara, Aude; Lopez-Rios, Tomas; Dumont, Sylvain; Gay, Frédéric; Quémerais, Pascal

    2010-08-01

    We describe a setup including a microscope to study volumes of a few mum(3) by static and dynamic light scattering (DLS) in a backscattering configuration. Light scattered by individual objects of micrometric size can be analyzed in the 400-800?nm spectral range. This setup can also be employed to study both diluted and concentrated colloidal solutions by DLS measurements. For diluted solutions we found evidence of the fluctuations of the number of particles in a confocal volume. We discuss their contribution to the autocorrelation function of the scattered intensity measured as a function of time.

  9. Polarized light in optics and spectroscopy

    CERN Document Server

    Kliger, David S

    1990-01-01

    This comprehensive introduction to polarized light provides students and researchers with the background and the specialized knowledge needed to fully utilize polarized light. It provides a basic introduction to the interaction of light with matter for those unfamiliar with photochemistry and photophysics. An in-depth discussion of polarizing optics is also given. Different analytical techniques are introduced and compared and introductions to the use of polarized light in various forms of spectroscopy are provided.Key Features* Starts at a basic level and develops tools for resear

  10. Dynamic polarization in paramagnetic solids and microscopic correlation functions

    International Nuclear Information System (INIS)

    Boucher, Jean-Paul

    1972-01-01

    The different effects of Dynamic Nuclear Polarization in paramagnetic solids are described by means of a single thermodynamic formalism. In the case of large exchange interactions, the Overhauser effect correlated with nuclear relaxation time measurements can provide a way of studying correlation functions between electronic spins. This method is used to study the low-frequency behaviour of the microscopic spectral density which should diverge as ω → 0, in the case of a linear exchange chain. (author) [fr

  11. Optical detection dental disease using polarized light

    Science.gov (United States)

    Everett, Matthew J.; Colston, Jr., Billy W.; Sathyam, Ujwal S.; Da Silva, Luiz B.; Fried, Daniel

    2003-01-01

    A polarization sensitive optical imaging system is used to detect changes in polarization in dental tissues to aid the diagnosis of dental disease such as caries. The degree of depolarization is measured by illuminating the dental tissue with polarized light and measuring the polarization state of the backscattered light. The polarization state of this reflected light is analyzed using optical polarimetric imaging techniques. A hand-held fiber optic dental probe is used in vivo to direct the incident beam to the dental tissue and collect the reflected light. To provide depth-resolved characterization of the dental tissue, the polarization diagnostics may be incorporated into optical coherence domain reflectometry and optical coherence tomography (OCDR/OCT) systems, which enables identification of subsurface depolarization sites associated with demineralization of enamel or bone.

  12. Interferometric method for birefringence determination with a polarizing microscope.

    Science.gov (United States)

    Dumitraşcu, Leonaş; Dumitraşcu, Irina; Dorohoi, Dana-Ortansa; Toma, Mihai

    2008-12-08

    We present a new mathematical technique which can be used to determine the main refractive indices and the birefringence of an anisotropic layer by using a polarizing microscope in conoscopic illumination. The values of the birefringence for the yellow radiation of a Na lamp are determined here for a Carpathian quartz sample, but the technique can also be applied to the study of other uniaxial substances such as liquid crystals, model membranes or biological tissues. The validity of the proposed method was tested by comparing the results with those obtained with a Rayleigh interferometer and by using the technology of channeled spectra.

  13. Characterization of Partially Polarized Light Fields

    CERN Document Server

    Martínez-Herrero, Rosario; Piquero, Gemma

    2009-01-01

    Polarization involves the vectorial nature of light fields. In current applications of optical science, the electromagnetic description of light with its vector features has been shown to be essential: In practice, optical radiation also exhibits randomness and spatial non-uniformity of the polarization state. Moreover, propagation through photonic devices can alter the correlation properties of the light field, resulting in changes in polarization. All these vectorial properties have been gaining importance in recent years, and they are attracting increasing attention in the literature. This is the framework and the scope of the present book, which includes the authors’ own contributions to these issues.

  14. Hybrid fluorescent layer emitting polarized light

    Directory of Open Access Journals (Sweden)

    Mohammad Mohammadimasoudi

    2017-07-01

    Full Text Available Semiconductor nanorods have anisotropic absorption and emission properties. In this work a hybrid luminescent layer is produced based on a mixture of CdSe/CdS nanorods dispersed in a liquid crystal that is aligned by an electric field and polymerized by UV illumination. The film emits light with polarization ratio 0.6 (polarization contrast 4:1. Clusters of nanorods in liquid crystal can be avoided by applying an AC electric field with sufficient amplitude. This method can be made compatible with large-scale processing on flexible transparent substrates. Thin polarized light emitters can be used in LCD backlights or solar concentrators to increase the efficiency.

  15. A note on polarized light from magnetars

    Energy Technology Data Exchange (ETDEWEB)

    Capparelli, L.M.; Damiano, A.; Polosa, A.D. [Sapienza Universita di Roma, Dipartimento di Fisica, Rome (Italy); INFN, Rome (Italy); Maiani, L. [CERN, Theory Department, Geneva (Switzerland)

    2017-11-15

    In a recent paper it is claimed that vacuum birefringence has been experimentally observed for the first time by measuring the degree of polarization of visible light from a magnetar candidate, a neutron star with a magnetic field presumably as large as B ∝ 10{sup 13} G. The role of such a strong magnetic field is twofold. First, the surface of the star emits, at each point, polarized light with linear polarization correlated with the orientation of the magnetic field. Depending on the relative orientation of the magnetic axis of the star with the direction to the distant observer, a certain degree of polarization should be visible. Second, the strong magnetic field in the vacuum surrounding the star could enhance the effective degree of polarization observed: vacuum birefringence. We compare experimental data and theoretical expectations concluding that the conditions to support a claim of strong evidence of vacuum birefringence effects are not met. (orig.)

  16. Point-spread functions of a polarizing microscope equipped with high-numerical-aperture lenses.

    Science.gov (United States)

    Oldenbourg, R; Török, P

    2000-12-01

    In an effort to establish the imaging properties of a new type of polarized-light microscope, we recorded images of small, uniaxial, birefringent crystals. We show that the sequence of in-focus and out-of-focus images, the so-called point-spread function, of a submicroscopic crystal can be used to measure the orientation of its optic axis in three-dimensional space. By analogy to conoscopic images out-of-focus images reveal the changes in relative phase shift between the extraordinary and the ordinary rays that propagate at different directions through the crystal. We also present simulated images of a pointlike anisotropic scattering particle and compare these with our experimental findings. The theoretical model is based on a complete vectorial theory for partial coherent imaging by use of polarized light and high-numerical-aperture lenses.

  17. Implementation of a virtual correlative light and transmission electron microscope.

    Science.gov (United States)

    Voigt, Tilman; Zuber, Benoît; Gawatz, Gerlinde; Herrmann, Gudrun

    2013-07-01

    In the long run, the widespread use of slide scanners by pathologists requires an adaptation of teaching methods in histology and cytology in order to target these new possibilities of image processing and presentation via the internet. Accordingly, we were looking for a tool with the possibility to teach microscopic anatomy, histology, and cytology of tissue samples which would be able to combine image data from light and electron microscopes independently of microscope suppliers. With the example of a section through the villus of jejunum, we describe here how to process image data from light and electron microscopes in order to get one image-stack which allows a correlation of structures from the microscopic anatomic to the cytological level. With commercially available image-presentation software that we adapted to our needs, we present here a platform which allows for the presentation of this new but also of older material independently of microscope suppliers. Copyright © 2013 Wiley Periodicals, Inc.

  18. Effect of operating microscope light on brain temperature during craniotomy.

    Science.gov (United States)

    Gayatri, Parthasarathi; Menon, Girish G; Suneel, Puthuvassery R

    2013-07-01

    Operating microscopes used during neurosurgery are fitted with xenon light. Burn injuries have been reported because of xenon microscope lighting as the intensity of xenon light is 300 W. We designed this study to find out if the light of operating microscope causes an increase in temperature of the brain tissue, which is exposed underneath. Twenty-one adult patients scheduled for elective craniotomies were enrolled. Distal esophageal temperature (T Eso), brain temperature under the microscope light (T Brain), and brain temperature under dura mater (T Dura) were measured continuously at 15-minute intervals during microscope use. The irrigation fluid temperature, room temperature, intensity of the microscope light, and the distance of the microscope from the brain surface were kept constant. The average age of the patients was 44±15 years (18 males and 3 females). The mean duration of microscope use was 140±39 minutes. There were no significant changes in T Brain and T Dura and T Eso over time. T Dura was significantly lower than T Brain both at time 0 and 60 minutes but not at 90 minutes. T Brain was significantly lower than T Eso both at time 0 and 60 minutes but not at 90 minutes. The T Dura remained significantly lower than T Eso at 0, 60, and 90 minutes. Our study shows that there is no significant rise in brain temperature under xenon microscope light up to 120 minutes duration, at intensity of 60% to 70%, from a distance of 20 to 25 cm from the brain surface.

  19. Hyaline ring granuloma: a case report with histochemical and polarized microscopic studies.

    Science.gov (United States)

    Lin, S K; Chiang, C P; Ou, S H; Wang, J T; Liu, B Y; Lan, W H

    1993-11-01

    An unusual case of hyaline ring granuloma arising from the connective tissue wall of a residual apical periodontal cyst is reported. Hyaline rings with foreign-body type giant cell inclusions were a significant feature in the histopathologic diagnosis. Histochemical and polarized light microscopic studies suggested that the introduction of foreign material, possibly cellulose, through the postextraction socket into the cystic wall may have caused the granulomatous reaction and formation of the hyaline ring granuloma. The clinical features of this case and 66 previously reported cases, as well as the pathogenesis of the hyaline rings, are discussed.

  20. Studying aerosol light scattering based on aspect ratio distribution observed by fluorescence microscope.

    Science.gov (United States)

    Li, Li; Zheng, Xu; Li, Zhengqiang; Li, Zhanhua; Dubovik, Oleg; Chen, Xingfeng; Wendisch, Manfred

    2017-08-07

    Particle shape is crucial to the properties of light scattered by atmospheric aerosol particles. A method of fluorescence microscopy direct observation was introduced to determine the aspect ratio distribution of aerosol particles. The result is comparable with that of the electron microscopic analysis. The measured aspect ratio distribution has been successfully applied in modeling light scattering and further in simulation of polarization measurements of the sun/sky radiometer. These efforts are expected to improve shape retrieval from skylight polarization by using directly measured aspect ratio distribution.

  1. Integration of a high-NA light microscope in a scanning electron microscope.

    Science.gov (United States)

    Zonnevylle, A C; Van Tol, R F C; Liv, N; Narvaez, A C; Effting, A P J; Kruit, P; Hoogenboom, J P

    2013-10-01

    We present an integrated light-electron microscope in which an inverted high-NA objective lens is positioned inside a scanning electron microscope (SEM). The SEM objective lens and the light objective lens have a common axis and focal plane, allowing high-resolution optical microscopy and scanning electron microscopy on the same area of a sample simultaneously. Components for light illumination and detection can be mounted outside the vacuum, enabling flexibility in the construction of the light microscope. The light objective lens can be positioned underneath the SEM objective lens during operation for sub-10 μm alignment of the fields of view of the light and electron microscopes. We demonstrate in situ epifluorescence microscopy in the SEM with a numerical aperture of 1.4 using vacuum-compatible immersion oil. For a 40-nm-diameter fluorescent polymer nanoparticle, an intensity profile with a FWHM of 380 nm is measured whereas the SEM performance is uncompromised. The integrated instrument may offer new possibilities for correlative light and electron microscopy in the life sciences as well as in physics and chemistry. © 2013 The Authors Journal of Microscopy © 2013 Royal Microscopical Society.

  2. UV-visible microscope spectrophotometric polarization and dichroism with increased discrimination power in forensic analysis

    Science.gov (United States)

    Purcell, Dale Kevin

    Microanalysis of transfer (Trace) evidence is the application of a microscope and microscopical techniques for the collection, observation, documentation, examination, identification, and discrimination of micrometer sized particles or domains. Microscope spectrophotometry is the union of microscopy and spectroscopy for microanalysis. Analytical microspectroscopy is the science of studying the emission, reflection, transmission, and absorption of electromagnetic radiation to determine the structure or chemical composition of microscopic-size materials. Microscope spectrophotometry instrument designs have evolved from monochromatic illumination which transmitted through the microscope and sample and then is detected by a photometer detector (photomultiplier tube) to systems in which broad-band (white light) illumination falls incident upon a sample followed by a non-scanning grating spectrometer equipped with a solid-state multi-element detector. Most of these small modern spectrometers are configured with either silicon based charged-couple device detectors (200-950 nm) or InGaAs based diode array detectors (850-2300 nm) with computerized data acquisition and signal processing being common. A focus of this research was to evaluate the performance characteristics of various modern forensic (UV-Vis) microscope photometer systems as well as review early model instrumental designs. An important focus of this research was to efficiently measure ultraviolet-visible spectra of microscopically small specimens for classification, differentiation, and possibly individualization. The first stage of the project consisted of the preparation of microscope slides containing neutral density filter reference materials, molecular fluorescence reference materials, and dichroic reference materials. Upon completion of these standard slide preparations analysis began with measurements in order to evaluate figures of merit for comparison of the instruments investigated. The figures of

  3. Scanning differential polarization microscope: Its use to image linear and circular differential scattering

    International Nuclear Information System (INIS)

    Mickols, W.; Maestre, M.F.

    1988-01-01

    A differential polarization microscope that couples the sensitivity of single-beam measurement of circular dichroism and circular differential scattering with the simultaneous measurement of linear dichroism and linear differential scattering has been developed. The microscope uses a scanning microscope stage and single-point illumination to give the very shallow depth of field found in confocal microscopy. This microscope can operate in the confocal mode as well as in the near confocal condition that can allow one to program the coherence and spatial resolution of the microscope. This microscope has been used to study the change in the structure of chromatin during the development of sperm in Drosophila

  4. Minimizing light exposure with the programmable array microscope.

    Science.gov (United States)

    Caarls, W; Rieger, B; De Vries, A H B; Arndt-Jovin, D J; Jovin, T M

    2011-01-01

    The exposure of fluorophores to intense illumination in a microscope often results in photobleaching and phototoxicity, thus constituting a major limiting factor in time lapse live cell or single molecule imaging. Laser scanning confocal microscopes are particularly prone to this problem, inasmuch as they require high irradiances to compensate for the inherently low duty cycle of point scanning systems. In the attempt to maintain adequate speed and signal-to-noise ratios, the fluorophores are often driven into saturation, thereby generating a nonlinear response. One approach for reducing photodegradation in the laser scanning confocal microscope is represented by controlled light exposure microscopy, introduced by Manders and colleagues. The strategy is to reduce the illumination intensity in both background areas (devoid of information) as well as in bright foreground regions, for which an adequate signal-to-noise ratio can be achieved with lower excitation levels than those required for the less intense foreground pixels/voxels. Such a variable illumination scheme can also be exploited in widefield microscopes that employ lower irradiance but higher illumination duty cycles. We report here on the adaptation of the controlled light exposure microscopy principle to the programmable array microscope, which achieves optical sectioning by use of a spatial light modulator (SLM) in an image plane as a programmable mask for illumination and conjugate (and nonconjugate) detection. By incorporating the basic controlled light exposure microscopy concept for minimizing exposure, we have obtained a reduction in the rate of photobleaching of up to ~5-fold, while maintaining an image quality comparable to regular imaging with the programmable array microscope. © 2010 The Authors Journal of Microscopy © 2010 The Royal Microscopical Society.

  5. Circularly polarized light emission in scanning tunneling microscopy of magnetic systems

    International Nuclear Information System (INIS)

    Apell, S.P.; Penn, D.R.; Johansson, P.

    2000-01-01

    Light is produced when a scanning tunneling microscope is used to probe a metal surface. Recent experiments on cobalt utilizing a tungsten tip found that the light is circularly polarized; the sense of circular polarization depends on the direction of the sample magnetization, and the degree of polarization is of order 10%. This raises the possibility of constructing a magnetic microscope with very good spatial resolution. We present a theory of this effect for iron and cobalt and find a degree of polarization of order 0.1%. This is in disagreement with the experiments on cobalt as well as previous theoretical work which found order of magnitude agreement with the experimental results. However, a recent experiment on iron showed 0.0±2%. We predict that the use of a silver tip would increase the degree of circular polarization for a range of photon energies

  6. Some Activities with Polarized Light from a Laptop LCD Screen

    Science.gov (United States)

    Fakhruddin, Hasan

    2008-01-01

    The LCD screen of a laptop computer provides a broad, bright, and extended source of polarized light. A number of demonstrations on the properties of polarized light from a laptop computer screens are presented here.

  7. Incidence, risk factors, and morphology in operating microscope light retinopathy

    International Nuclear Information System (INIS)

    Khwarg, S.G.; Linstone, F.A.; Daniels, S.A.; Isenberg, S.J.; Hanscom, T.A.; Geoghegan, M.; Straatsma, B.R.

    1987-01-01

    A review of 135 consecutive cataract operations identified ten cases (7.4%) of operating microscope light retinopathy. Ophthalmoscopically, these light retinopathy lesions appeared as a focal pigment epithelial change with varying degrees of pigment clumping in the center. Fluorescein angiography accentuated the lesion by demonstrating a sharply demarcated transmission defect, occasionally with multiple satellite lesions. The shape of the lesion matched the shape of the illuminating source of the particular operating microscope used during the surgery. The most significant risk factor associated with the production of these light retinopathy lesions was prolonged operating time. Mean total operating time for the ten patients with light retinopathy was 51 minutes longer than for those without (P less than .0001). Other significant associated factors were the presence of diabetes mellitus (P less than .03), younger age (P less than .05), and the use of hydrochlorothiazide (P less than .04)

  8. Incidence, risk factors, and morphology in operating microscope light retinopathy

    Energy Technology Data Exchange (ETDEWEB)

    Khwarg, S.G.; Linstone, F.A.; Daniels, S.A.; Isenberg, S.J.; Hanscom, T.A.; Geoghegan, M.; Straatsma, B.R.

    1987-03-15

    A review of 135 consecutive cataract operations identified ten cases (7.4%) of operating microscope light retinopathy. Ophthalmoscopically, these light retinopathy lesions appeared as a focal pigment epithelial change with varying degrees of pigment clumping in the center. Fluorescein angiography accentuated the lesion by demonstrating a sharply demarcated transmission defect, occasionally with multiple satellite lesions. The shape of the lesion matched the shape of the illuminating source of the particular operating microscope used during the surgery. The most significant risk factor associated with the production of these light retinopathy lesions was prolonged operating time. Mean total operating time for the ten patients with light retinopathy was 51 minutes longer than for those without (P less than .0001). Other significant associated factors were the presence of diabetes mellitus (P less than .03), younger age (P less than .05), and the use of hydrochlorothiazide (P less than .04).

  9. Light microscopic detection of Plasmodium falciparum in vitro ...

    African Journals Online (AJOL)

    The parasite count was titrated against the Pf-HRP 2 gold conjugate and was analyzed under the light microscope with a fluorescent filter. Reactivity and specificity of Pf-HRP 2 gold conjugate was found to be highly specific and gave direct identification of the erythrocytes infected with the parasite. A good contrast was also ...

  10. Simple structured illumination microscope setup with high acquisition speed by using a spatial light modulator.

    Science.gov (United States)

    Förster, Ronny; Lu-Walther, Hui-Wen; Jost, Aurélie; Kielhorn, Martin; Wicker, Kai; Heintzmann, Rainer

    2014-08-25

    We describe a two-beam interference structured illumination fluorescence microscope. The novelty of the presented system lies in its simplicity. A programmable spatial light modulator (ferroelectric LCoS) in an intermediate image plane enables precise and rapid control of the excitation pattern in the specimen. The contrast of the projected light pattern is strongly influenced by the polarization state of the light entering the high NA objective. To achieve high contrast, we use a segmented polarizer. Furthermore, a mask with six holes blocks unwanted components in the spatial frequency spectrum of the illumination grating. Both these passive components serve their purpose in a simpler and almost as efficient way as active components. We demonstrate a lateral resolution of 114.2 ± 9.5 nm at a frame rate of 7.6 fps per reconstructed 2D slice.

  11. Light sheet microscopes: Novel imaging toolbox for visualizing life's processes.

    Science.gov (United States)

    Heddleston, John M; Chew, Teng-Leong

    2016-11-01

    Capturing dynamic processes in live samples is a nontrivial task in biological imaging. Although fluorescence provides high specificity and contrast compared to other light microscopy techniques, the photophysical principles of this method can have a harmful effect on the sample. Current advances in light sheet microscopy have created a novel imaging toolbox that allows for rapid acquisition of high-resolution fluorescent images with minimal perturbation of the processes of interest. Each unique design has its own advantages and limitations. In this review, we describe several cutting edge light sheet microscopes and their optimal applications. Copyright © 2016 Elsevier Ltd. All rights reserved.

  12. Superconducting Undulator with Variably Polarized Light

    CERN Document Server

    Hwang, Ching Shiang; Ching Fan, Tai; Li, W P; Lin, P H

    2004-01-01

    This study investigates planar in-vacuo superconducting undulators with periodic length of 5 cm (IVSU5) producing linearly and circularly polarized infrared rays or xrays source. The vertically wound racetrack coil is selected for the coil and pole fabrication of the IVSU5. When the up and down magnetic pole arrays with alternative directions rotated wires in the horizontal plane, a helical field radiates circularly polarized light in the electron storage ring, the free electron laser (FEL), and the energy recovery linac (ERL) facilities. Meanwhile, an un-rotated wire is constructed together with the rotated wire on the same undulator is used to switch the linear horizontal and vertical, the right- and left-circular polarization radiation. Given a periodic length of 5 cm and a gap of 23 mm, the maximum magnetic flux density in the helical undulator are Bz = 1.5 T and Bx = 0.5 T when the wires rotated by 20°. This article describes the main factors of the planar and helical undulator design for FEL and...

  13. Compact scanning tunneling microscope for spin polarization measurements.

    Science.gov (United States)

    Kim, Seong Heon; de Lozanne, Alex

    2012-10-01

    We present a design for a scanning tunneling microscope that operates in ultrahigh vacuum down to liquid helium temperatures in magnetic fields up to 8 T. The main design philosophy is to keep everything compact in order to minimize the consumption of cryogens for initial cool-down and for extended operation. In order to achieve this, new ideas were implemented in the design of the microscope body, dewars, vacuum chamber, manipulators, support frame, and vibration isolation. After a brief description of these designs, the results of initial tests are presented.

  14. Versatile multispectral microscope based on light emitting diodes.

    Science.gov (United States)

    Brydegaard, Mikkel; Merdasa, Aboma; Jayaweera, Hiran; Ålebring, Jens; Svanberg, Sune

    2011-12-01

    We describe the development of a novel multispectral microscope, based on light-emitting diodes, capable of acquiring megapixel images in thirteen spectral bands from the ultraviolet to the near infrared. The system captures images and spectra in transmittance, reflectance, and scattering modes. We present as examples of applications ground truth measurements for remote sensing and parasitology diagnostics. The system is a general purpose scientific instrument that could be used to develop dedicated simplified instruments with optimal bands and mode selection.

  15. Morphometric Evaluation of Preeclamptic Placenta Using Light Microscopic Images

    OpenAIRE

    Mukherjee, Rashmi

    2014-01-01

    Deficient trophoblast invasion and anomalies in placental development generally lead to preeclampsia (PE) but the inter-relationship between placental function and morphology in PE still remains unknown. The aim of this study was to evaluate the morphometric features of placental villi and capillaries in preeclamptic and normal placentae. The study included light microscopic images of placental tissue sections of 40 preeclamptic and 35 normotensive pregnant women. Preprocessing and segmentati...

  16. On-axis programmable microscope using liquid crystal spatial light modulator

    Science.gov (United States)

    García-Martínez, Pascuala; Martínez, José Luís.; Moreno, Ignacio

    2017-06-01

    Spatial light modulators (SLM) are currently used in many applications in optical microscopy and imaging. One of the most promising methods is the use of liquid crystal displays (LCD) as programmable phase diffractive optical elements (DOE) placed in the Fourier plane giving access to the spatial frequencies which can be phased shifted individually, allowing to emulate a wealth of contrast enhancing methods for both amplitude and phase samples. We use phase and polarization modulation of LCD to implement an on-axis microscope optical system. The LCD used are Hamamatsu liquid crystal on silicon (LCOS) SLM free of flicker, thus showing a full profit of the SLM space bandwidth, as opposed to optical systems in the literature forced to work off-axis due to the strong zero-order component. Taking benefits of the phase modulation of the LCOS we have implemented different microscopic imaging operations, such as high-pass and low-pass filtering in parallel using programmable blazed gratings. Moreover, we are able to control polarization modulation to display two orthogonal linear state of polarization images than can be subtracted or added by changing the period of the blazed grating. In that sense, Differential Interference Contrast (DIC) microscopy can be easily done by generating two images exploiting the polarization splitting properties when a blazed grating is displayed in the SLM. Biological microscopy samples are also used.

  17. Polarization fluctuations in stationary light beams

    International Nuclear Information System (INIS)

    Shevchenko, A.; Setaelae, T.; Kaivola, M.; Friberg, A.T.; Royal Institute of Technology , Department of Microelectronics and Applied Physics; Sweden)

    2009-01-01

    For stationary beams the degree of polarization contains only limited information on time dependent polarization. Two approaches towards assessing a beams polarization dynamics, one based on Poincare and the other on Jones vector formalism, are described leading to the notion of polarization time. Specific examples of partially temporally coherent electromagnetic beams are discussed. (Author)

  18. White light differential interference contrast microscope with a Sagnac interferometer.

    Science.gov (United States)

    Chatterjee, Sanjib; Pavan Kumar, Y

    2014-01-10

    A new technique for producing a white light differential interference contrast (DIC) image using a lateral shearing, rotation phase shifting Sagnac interferometer (SI) is proposed. The SI, placed in the image space after the tube lens of a microscope system with spatially coherent white light Kohler illumination, splits the image forming beam into coherent components with small lateral shear. Phase shifts, between the interfering components, which can be considered as biased phase difference (BPD), are introduced by applying small angular rotation of the SI in its own plane. This variable BPD between the interfering white light components produces a uniform intensity colored background. The object related phase shift, due to the height difference between two close points on the object surface with separation on the order of least resolvable separation of the microscope objective, in addition to the BPD would produce a change in intensity/hue/color against a uniform background due to the BPD. Thus a DIC image is formed and the variable BPD provides an excellent means of improving the contrast of the image.

  19. Polarization resolved imaging with a reflection near-field optical microscope

    DEFF Research Database (Denmark)

    Bozhevolnyi, Sergey I.; Xiao, Mufei; Hvam, Jørn Märcher

    1999-01-01

    Using a rigorous microscopic point-dipole description of probe-sample interactions, we study imaging with a reflection scanning near-field optical microscope. Optical content, topographical artifacts, sensitivity window-i.e., the scale on which near-field optical images represent mainly optical...... contrast-and symmetry properties are considered for optical images obtained in constant-distance mode for different polarization configurations. We demonstrate that images obtained in cross-polarized detection mode are free of background and topographical artifacts and that the cross-circular polarization...... configuration is preferable to the cross-linear one, since it ensures more isotropic (in the surface plane) near-field imaging of surface features. The numerical results are supported with experimental near-field images obtained by using a reflection microscope with an uncoated fiber tip....

  20. Efficient propagation of TM polarized light in photonic crystal components exhibiting band gaps for TE polarized light

    DEFF Research Database (Denmark)

    Borel, Peter Ingo; Frandsen, Lars Hagedorn; Thorhauge, Morten

    2003-01-01

    D finite-difference-time-domain method. The simulated spectra are in excellent agreement with the experimental results, which show a propagation loss as low as 2.5±4 dB/mm around 1525 nm and bend losses at 2.9±0.2 dB for TM polarized light. We demonstrate a high coupling for TM polarized light......We have investigated the properties of TM polarized light in planar photonic crystal waveguide structures, which exhibit photonic band gaps for TE polarized light. Straight and bent photonic crystal waveguides and couplers have been fabricated in silicon-on-insulator material and modelled using a 3...

  1. Morphometric Evaluation of Preeclamptic Placenta Using Light Microscopic Images

    Directory of Open Access Journals (Sweden)

    Rashmi Mukherjee

    2014-01-01

    Full Text Available Deficient trophoblast invasion and anomalies in placental development generally lead to preeclampsia (PE but the inter-relationship between placental function and morphology in PE still remains unknown. The aim of this study was to evaluate the morphometric features of placental villi and capillaries in preeclamptic and normal placentae. The study included light microscopic images of placental tissue sections of 40 preeclamptic and 35 normotensive pregnant women. Preprocessing and segmentation of these images were performed to characterize the villi and capillaries. Fisher’s linear discriminant analysis (FLDA, hierarchical cluster analysis (HCA, and principal component analysis (PCA were applied to identify the most significant placental (morphometric features from microscopic images. A total of 10 morphometric features were extracted, of which the villous parameters were significantly altered in PE. FLDA identified 5 highly significant morphometric features (>90% overall discrimination accuracy. Two large subclusters were clearly visible in HCA based dendrogram. PCA returned three most significant principal components cumulatively explaining 98.4% of the total variance based on these 5 significant features. Hence, quantitative microscopic evaluation revealed that placental morphometry plays an important role in characterizing PE, where the villous is the major component that is affected.

  2. Morphometric evaluation of preeclamptic placenta using light microscopic images.

    Science.gov (United States)

    Mukherjee, Rashmi

    2014-01-01

    Deficient trophoblast invasion and anomalies in placental development generally lead to preeclampsia (PE) but the inter-relationship between placental function and morphology in PE still remains unknown. The aim of this study was to evaluate the morphometric features of placental villi and capillaries in preeclamptic and normal placentae. The study included light microscopic images of placental tissue sections of 40 preeclamptic and 35 normotensive pregnant women. Preprocessing and segmentation of these images were performed to characterize the villi and capillaries. Fisher's linear discriminant analysis (FLDA), hierarchical cluster analysis (HCA), and principal component analysis (PCA) were applied to identify the most significant placental (morphometric) features from microscopic images. A total of 10 morphometric features were extracted, of which the villous parameters were significantly altered in PE. FLDA identified 5 highly significant morphometric features (>90% overall discrimination accuracy). Two large subclusters were clearly visible in HCA based dendrogram. PCA returned three most significant principal components cumulatively explaining 98.4% of the total variance based on these 5 significant features. Hence, quantitative microscopic evaluation revealed that placental morphometry plays an important role in characterizing PE, where the villous is the major component that is affected.

  3. Managing light polarization via plasmon-molecule interactions within an asymmetric metal nanoparticle trimer

    International Nuclear Information System (INIS)

    Shegai, Timur; Li, Zhipeng; Zhang, Zhenyu; Xu, Hongxing; Haran, Gilad

    2008-01-01

    The interaction of light with metal nanoparticles leads to novel phenomena mediated by surface plasmon excitations. In this paper we use single molecules to characterize the interaction of surface plasmons with light, and show that such interaction can strongly modulate the polarization of the emitted light. The simplest nanostructures that enable such polarization modulation are asymmetric silver nanocrystal trimers, where individual Raman scattering molecules are located in the gap between two of the nanoparticles. The third particle breaks the dipolar symmetry of the two-particle junction, generating a wavelength-dependent polarization pattern. Indeed, the scattered light becomes elliptically polarized and its intensity pattern is rotated in the presence of the third particle. We use a combination of spectroscopic observations on single molecules, scanning electron microscope imaging, and generalized Mie theory calculations to provide a full picture of the effect of particles on the polarization of the emitted light. Furthermore, our theoretical analysis allows us to show that the observed phenomenon is very sensitive to the size of the trimer particles and their relative position, suggesting future means for precise control of light polarization on the nanoscale.

  4. Light-matter interactions in a polarization standing wave

    OpenAIRE

    Fang, X.; MacDonald, K.F.; Zheludev, N.I.

    2015-01-01

    We report on the application of polarization standing waves (PSW) to the coherent control of light-matter interactions in planar photonic nanostructures. Such waves, formed by counter-propagating (linear or circular) orthogonally polarized beams can uniquely detect polarization conversion, planar chirality and related asymmetric transmission effects.

  5. Microscopic theory of fully spin-polarized /sup 3/He

    Energy Technology Data Exchange (ETDEWEB)

    Glyde, H.R.; Hernadi, S.I.

    1983-01-01

    The ground state energy (E), Landau parameters (F) and single particle energy spectrum (epsilon(kappa) and m/sup */) in fully spin polarized liquid /sup 3/He (/sup 3/He) are calculated directly from the bare interatomic potential within the Galitskii-Feynmann T-matrix and Hartree-Fock (GFHF) approximations. The E agrees well with variational calculations, the F with model calculations and the epsilon(kappa) and m/sup */ with results expected from nuclear matter. This suggests the effective interaction in /sup 3/He is dominated by hard core repulsion and Fermi statistics and that these components of the full interaction can be well described from first principles by a GF T-matrix. 36 references, 3 figures, 1 table.

  6. Polymer photovoltaic cells sensitive to the circular polarization of light

    Energy Technology Data Exchange (ETDEWEB)

    Gilot, Jan; Abbel, Robert; Lakhwani, Girish; Meijer, E.W.; Schenning, Albertus P.H.J.; Meskers, Stefan C.J. [Laboratory of Macromolecular and Organic Chemistry, Eindhoven University of Technology (Netherlands)

    2010-05-25

    Chiral conjugated polymer is used to construct a photovoltaic cell whose response depends on the circular polarization of the incoming light. The selectivity for left and right polarized light as a function of the thickness of the polymer layer is accounted for by modeling of the optical properties of all layers inside the device. (Abstract Copyright [2010], Wiley Periodicals, Inc.)

  7. Simulation of erasure of photoinduced anisotropy by circularly polarized light

    DEFF Research Database (Denmark)

    Sajti, Sz.; Kerekes, Á.; Barabás, M.

    2001-01-01

    The temporal evolution of photoinduced birefringence is investigated on the basis of a model proposed by Pedersen and co-workers, This model is extended for the case of elliptically polarized light, and used to describe the erasure of photoinduced birefringence by circularly polarized light...

  8. [Application of polarized light in purulent-septic surgery].

    Science.gov (United States)

    Desiateryk, V I; Mikhno, S P; Kryvyts'kyĭ, Iu M; Kostiuk, S O

    2002-09-01

    Influence of polarized light on general state and healing of wounds and trophic ulcers in 57 patients with obliterating atherosclerosis of lower extremities, chronic venous insufficiency of extremities, purulent postoperative complications, purulent-septic complications in patients with diabetes mellitus was analyzed. Main mechanisms of the polarized light action in "Bioptron" apparatus were enlighted, effective schemes of its usage were determined.

  9. Propagation of polarized light in turbid media: simulated animation sequences

    OpenAIRE

    Yao, Gang; Wang, Lihong V.

    2000-01-01

    A time-resolved Monte Carlo technique was used to simulate the propagation of polarized light in turbid media. Calculated quantities include the reflection Mueller matrices, the transmission Mueller matrices, and the degree of polarization (DOP). The effects of the polarization state of the incident light and of the size of scatterers on the propagation of DOP were studied. Results are shown in animation sequences.

  10. Polarization sensitivity of light diffraction for periodic array of anisotropic gold nanoparticles

    International Nuclear Information System (INIS)

    Tsai, Ming-shan; Liu, Tung-kai; Tsen, Chun-yu; Ting, Chen-ching

    2015-01-01

    This article aims to analyze the first order diffraction intensity of the incident polarized light which is diffracted by the gold nanoparticles array in terms of the surface plasmon effect. The inspected gold nanoparticles array films are built in grating pattern with stripe thickness of 4 μm and diameters of gold nanoparticles ca. 10–56 nm, which are formed by annealing at temperatures of 400, 450, 500, and 550 °C, respectively. The probing light is linearly polarized with wavelengths of 450–800 nm and counterclockwise turns its polarization direction from 0° to 90° during measurements. The results show that the diffraction intensity depends on the anisotropic configuration samples which gold nanoparticles are orientated by analyzing the scanning electron microscope images. It results that the localized surface plasmon effect induced by incident field depends on orientation and causes the sample polarization-sensitive

  11. New, simple theory-based, accurate polarization microscope for birefringence imaging of biological cells

    Science.gov (United States)

    Shin, In Hee; Shin, Sang-Mo; Kim, Dug Young

    2010-01-01

    We propose a new, simple theory-based, accurate polarization microscope for birefringence imaging of cytoskeletal structures of biological cells. The new theory lets us calculate very easily the phase retardation and the orientation of the principal axis of a particular area of a biological living cell in media by simply measuring the intensity variation of a pixel of a CCD camera while rotating a single polarizer. Just from the measured intensity maxima and minima, the amount of phase retardation δ between the fast and the slow axis of the sample area is obtained with an accuracy of 5.010+/-0.798×10-3 rad. The orientation of the principal axis is calculated from the angle of the polarizer for the intensity maximum. We have compared our microscopes with two previously reported polarization microscopes for birefringence imaging of cytoskeletal structures and demonstrated the utility of our microscope with the phase retardation and orientation images of weakly invasive MCF7 and highly invasive MDA MB 231 human breast cancer cells as an example.

  12. Light Microscopy Module: International Space Station Premier Automated Microscope

    Science.gov (United States)

    Sicker, Ronald J.; Foster, William M.; Motil, Brian J.; Meyer, William V.; Chiaramonte, Francis P.; Abbott-Hearn, Amber; Atherton, Arthur; Beltram, Alexander; Bodzioney, Christopher; Brinkman, John; hide

    2016-01-01

    The Light Microscopy Module (LMM) was launched to the International Space Station (ISS) in 2009 and began hardware operations in 2010. It continues to support Physical and Biological scientific research on ISS. During 2016, if all goes as planned, three experiments will be completed: [1] Advanced Colloids Experiments with Heated base-2 (ACE-H2) and [2] Advanced Colloids Experiments with Temperature control (ACE-T1). Preliminary results, along with an overview of present and future LMM capabilities will be presented; this includes details on the planned data imaging processing and storage system, along with the confocal upgrade to the core microscope. [1] a consortium of universities from the State of Kentucky working through the Experimental Program to Stimulate Competitive Research (EPSCoR): Stuart Williams, Gerold Willing, Hemali Rathnayake, et al. and [2] from Chungnam National University, Daejeon, S. Korea: Chang-Soo Lee, et al.

  13. Mucopolysaccharides in the trabecular meshwork. Light and electron microscopic autoradiography

    Energy Technology Data Exchange (ETDEWEB)

    Ohnishi, Yoshitaka; Yamana, Yasuo; Abe, Masahiro (Kyushu Univ., Fukuoka (Japan). Faculty of Medicine)

    1982-09-01

    The localization of /sup 35/S-sulfate and /sup 3/H-glucosamine in the trabecular region of the hamster was studied by light and electron microscopic autoradiography after the intraperitoneal injection. Exposed silver grains of /sup 35/S-sulfate were concentrated in the trabecular meshwork, sclera and cornea, and grains of /sup 35/H-glucosamine were localized in the trabecular region. The radioactivity of both isotopes was observed in the Golgi apparatuses of the endothelial cells and fibroblasts in Schlemm's canal and the trabecular meshwork. Thereafter, the grains were noted over the entire cytoplasm, except for the nucleus, and then were incorporated into the amorphous substance and collagen fibers in the juxtacanalicular connective tissue. These results suggest that endothelial cells in the trabecular region synthesize and secrete the sulfated mucopolysaccharides and hyaluronic acid.

  14. Fiber optic light collection system for scanning-tunneling-microscope-induced light emission.

    Science.gov (United States)

    Watkins, Neil J; Long, James P; Kafafi, Zakya H; Mäkinen, Antti J

    2007-05-01

    We report a compact light collection scheme suitable for retrofitting a scanning tunneling microscope (STM) for STM-induced light emission experiments. The approach uses a pair of optical fibers with large core diameters and high numerical apertures to maximize light collection efficiency and to moderate the mechanical precision required for alignment. Bench tests indicate that efficiency reduction is almost entirely due to reflective losses at the fiber ends, while losses due to fiber misalignment have virtually been eliminated. Photon-map imaging with nanometer features is demonstrated on a stepped Au(111) surface with signal rates exceeding 10(4) counts/s.

  15. Lunar skylight polarization signal polluted by urban lighting

    Science.gov (United States)

    Kyba, C. C. M.; Ruhtz, T.; Fischer, J.; Hölker, F.

    2011-12-01

    On clear moonlit nights, a band of highly polarized light stretches across the sky at a 90 degree angle from the moon, and it was recently demonstrated that nocturnal organisms are able to navigate based on it. Urban skyglow is believed to be almost unpolarized, and is therefore expected to dilute this unique partially linearly polarized signal. We found that urban skyglow has a greater than expected degree of linear polarization (p = 8.6 ± 0.3%), and confirmed that its presence diminishes the natural lunar polarization signal. We also observed that the degree of linear polarization can be reduced as the moon rises, due to the misalignment between the polarization angles of the skyglow and scattered moonlight. Under near ideal observing conditions, we found that the lunar polarization signal was clearly visible (p = 29.2 ± 0.8%) at a site with minimal light pollution 28 km from Berlin's center, but was reduced (p = 11.3 ± 0.3%) within the city itself. Daytime measurements indicate that without skyglow p would likely be in excess of 50%. These results indicate that nocturnal animal navigation systems based on perceiving polarized scattered moonlight likely fail to operate properly in highly light-polluted areas, and that future light pollution models must take polarization into account.

  16. Polarized light modulates light-dependent magnetic compass orientation in birds

    Science.gov (United States)

    Muheim, Rachel; Sjöberg, Sissel; Pinzon-Rodriguez, Atticus

    2016-01-01

    Magnetoreception of the light-dependent magnetic compass in birds is suggested to be mediated by a radical-pair mechanism taking place in the avian retina. Biophysical models on magnetic field effects on radical pairs generally assume that the light activating the magnetoreceptor molecules is nondirectional and unpolarized, and that light absorption is isotropic. However, natural skylight enters the avian retina unidirectionally, through the cornea and the lens, and is often partially polarized. In addition, cryptochromes, the putative magnetoreceptor molecules, absorb light anisotropically, i.e., they preferentially absorb light of a specific direction and polarization, implying that the light-dependent magnetic compass is intrinsically polarization sensitive. To test putative interactions between the avian magnetic compass and polarized light, we developed a spatial orientation assay and trained zebra finches to magnetic and/or overhead polarized light cues in a four-arm “plus” maze. The birds did not use overhead polarized light near the zenith for sky compass orientation. Instead, overhead polarized light modulated light-dependent magnetic compass orientation, i.e., how the birds perceive the magnetic field. Birds were well oriented when tested with the polarized light axis aligned parallel to the magnetic field. When the polarized light axis was aligned perpendicular to the magnetic field, the birds became disoriented. These findings are the first behavioral evidence to our knowledge for a direct interaction between polarized light and the light-dependent magnetic compass in an animal. They reveal a fundamentally new property of the radical pair-based magnetoreceptor with key implications for how birds and other animals perceive the Earth’s magnetic field. PMID:26811473

  17. Do cephalopods communicate using polarized light reflections from their skin?

    Science.gov (United States)

    Mäthger, Lydia M; Shashar, Nadav; Hanlon, Roger T

    2009-07-01

    Cephalopods (squid, cuttlefish and octopus) are probably best known for their ability to change color and pattern for camouflage and communication. This is made possible by their complex skin, which contains pigmented chromatophore organs and structural light reflectors (iridophores and leucophores). Iridophores create colorful and linearly polarized reflective patterns. Equally interesting, the photoreceptors of cephalopod eyes are arranged in a way to give these animals the ability to detect the linear polarization of incoming light. The capacity to detect polarized light may have a variety of functions, such as prey detection, navigation, orientation and contrast enhancement. Because the skin of cephalopods can produce polarized reflective patterns, it has been postulated that cephalopods could communicate intraspecifically through this visual system. The term 'hidden' or 'private' communication channel has been given to this concept because many cephalopod predators may not be able to see their polarized reflective patterns. We review the evidence for polarization vision as well as polarization signaling in some cephalopod species and provide examples that tend to support the notion--currently unproven--that some cephalopods communicate using polarized light signals.

  18. Physical processes in azobenzene polymers on irradiation with polarized light

    DEFF Research Database (Denmark)

    Holme, N.C.R.; Nikolova, L.; Norris, T.B.

    1999-01-01

    . A transition route based on experimental results for the theoretically calculated energy level scheme is proposed. Physical observations of surface relief in thin films of azobenzene polymers when irradiated with polarized light are reported. These include two beam polarization holographic observations...

  19. Using Polarization features of visible light for automatic landmine detection

    NARCIS (Netherlands)

    Jong, W. de; Schavemaker, J.G.M.

    2007-01-01

    This chapter describes the usage of polarization features of visible light for automatic landmine detection. The first section gives an introduction to land-mine detection and the usage of camera systems. In section 2 detection concepts and methods that use polarization features are described.

  20. Polarized light imaging of birefringence and diattenuation at high resolution and high sensitivity

    International Nuclear Information System (INIS)

    Mehta, Shalin B; Shribak, Michael; Oldenbourg, Rudolf

    2013-01-01

    Polarized light microscopy provides unique opportunities for analyzing the molecular order in man-made and natural materials, including biological structures inside living cells, tissues, and whole organisms. 20 years ago, the LC-PolScope was introduced as a modern version of the traditional polarizing microscope enhanced by liquid crystal devices for the control of polarization, and by electronic imaging and digital image processing for fast and comprehensive image acquisition and analysis. The LC-PolScope is commonly used for birefringence imaging, analyzing the spatial and temporal variations of the differential phase delay in ordered and transparent materials. Here we describe an alternative use of the LC-PolScope for imaging the polarization dependent transmittance of dichroic materials. We explain the minor changes needed to convert the instrument between the two imaging modes, discuss the relationship between the quantities measured with each instrument, and touch on the physical connection between refractive index, birefringence, transmittance, diattenuation, and dichroism. (special issue article)

  1. The effects of polarized light therapy in pressure ulcer healing

    Directory of Open Access Journals (Sweden)

    Đurović Aleksandar

    2008-01-01

    Full Text Available Background/Aim. Neglecting polarized light as an adjuvant therapy for pressure ulcers and methodology distinctions in the trials engaging polarized light are the reasons for many dilemmas and contradictions. The aim of this study was to establish the effects of polarized light therapy in pressure ulcer healing. Methods. This prospective randomized single-blind study involved 40 patients with stage I-III of pressure ulcer. The patients in the experimental group (E were subjected, besides polarized light therapy, to standard wound cleaning and dressing. Standard wound cleaning and dressing were the only treatment used in the control group (C. A polarized light source was a Bioptron lamp. Polarized light therapy was applied for six min daily, five times a week, four weeks. The Pressure Ulcer Scale for Healing (PUSH was used in the assessment of outcome. Statistic analysis included Mann Whitney Test, Fisher Exact Test, Wilcoxon Signed Rank test. Results. There were significant differences between the groups at the end of the treatment regarding the surface of pressure ulcer (E: 10.80±19.18; C: 22,97±25,47; p = 0.0005, rank of pressure ulcer (E: 5.90±2.48; C: 8.6±1.05; p = 0.0005 and total PUSH score (E: 7.35±3.17; C: 11.85±2.35; p = 0,0003. The patients in the experimental group had significantly better values of the parameters monitored than the patients in the control group. Conclusion. After a four-week polarized light therapy 20 patients with stage I-III ulcer had significant improvement in pressure ulcer healing, so it could be useful to apply polarized light in the treatment of pressure ulcers.

  2. The effects of polarized light therapy in pressure ulcer healing.

    Science.gov (United States)

    Durović, Aleksandar; Marić, Dragan; Brdareski, Zorica; Jevtić, Miodrag; Durdević, Slavisa

    2008-12-01

    Neglecting polarized light as an adjuvant therapy for pressure ulcers and methodology distinctions in the trials engaging polarized light are the reasons for many dilemmas and contradictions. The aim of this study was to establish the effects of polarized light therapy in pressure ulcer healing. This prospective randomized single-blind study involved 40 patients with stage I-III of pressure ulcer. The patients in the experimental group (E) were subjected, besides polarized light therapy, to standard wound cleaning and dressing. Standard wound cleaning and dressing were the only treatment used in the control group (C). A polarized light source was a Bioptron lamp. Polarized light therapy was applied for six min daily, five times a week, four weeks. The Pressure Ulcer Scale for Healing (PUSH) was used in the assessment of outcome. Statistic analysis included Mann Whitney Test, Fisher Exact Test, Wilcoxon Signed Rank test. There were significant differences between the groups at the end of the treatment regarding the surface of pressure ulcer (E: 10.80 +/- 19.18; C: 22,97 +/- 25,47; p = 0.0005), rank of pressure ulcer (E: 5.90 +/- 2.48; C: 8.6 +/- 1.05; p = 0.0005) and total PUSH score (E: 7.35 +/- 3.17; C: 11.85 +/- 2.35; p = 0,0003). The patients in the experimental group had significantly better values of the parameters monitored than the patients in the control group. After a four-week polarized light therapy 20 patients with stage I-III ulcer had significant improvement in pressure ulcer healing, so it could be useful to apply polarized light in the treatment of pressure ulcers.

  3. Robust reflective ghost imaging against different partially polarized thermal light

    Science.gov (United States)

    Li, Hong-Guo; Wang, Yan; Zhang, Rui-Xue; Zhang, De-Jian; Liu, Hong-Chao; Li, Zong-Guo; Xiong, Jun

    2018-03-01

    We theoretically study the influence of degree of polarization (DOP) of thermal light on the contrast-to-noise ratio (CNR) of the reflective ghost imaging (RGI), which is a novel and indirect imaging modality. An expression for the CNR of RGI with partially polarized thermal light is carefully derived, which suggests a weak dependence of CNR on the DOP, especially when the ratio of the object size to the speckle size of thermal light has a large value. Different from conventional imaging approaches, our work reveals that RGI is much more robust against the DOP of the light source, which thereby has advantages in practical applications, such as remote sensing.

  4. OPTIMIZATION OF LAMBLIASIS MICROSCOPIC DIAGNOSTICS BY THE METHOD OF POLARIZED FLUORESCENCE FOR PATIENTS WITH ROSACEA AND URTICARIAL

    Directory of Open Access Journals (Sweden)

    Maryana Kovalchuk

    2013-07-01

    Full Text Available Introduction: There is little information about diagnosis of concurrent lambliasis in patients with rosacea and urticaria. We used method of polarized fluorescence to diagnose liambliasis, taking into account belonging of macromolecular structures of unicellular parasites Giardia lamblia to the optically active substances with the properties of liquid crystals. Material and Methods: Lambliasis was diagnosed on the basis of feces parasitological research and duodenal contents by methods of light and optic microscopy and polarized fluorescence in 105 patients with rosacea and urticaria. Research results were processed by the method of variation statistics in the Statgraf program by using Student’s criterion. Results: Search results of lamblia in patients with rosacea and urticaria depended on the conditions of its holding, patients’ preparation and from the previously received basic therapy if it consisted absorbents. Due to the fact that the fluorescence polarization as a physical method does not require the use of any generally toxic, dye- fluorochromes, qualitative cyto fluorescent analysis of lamblia in greeting microdrugs enables to distinguish vegetative forms of cysts. Conclussions: Polarized fluorescence method allows optimize the microscopic diagnosis of lambliasis, increasing its sensitivity. Previous preparation for the laboratory examination of Giardia lamblia is needed for the best exposure of vermin for patients with rosacea and urticaria.

  5. Microscopic structural study of collagen aging in isolated fibrils using polarized second harmonic generation

    Science.gov (United States)

    Aït-Belkacem, Dora; Guilbert, Marie; Roche, Muriel; Duboisset, Julien; Ferrand, Patrick; Sockalingum, Ganesh; Jeannesson, Pierre; Brasselet, Sophie

    2012-08-01

    Polarization resolved second harmonic generation (PSHG) is developed to study, at the microscopic scale, the impact of aging on the structure of type I collagen fibrils in two-dimensional coatings. A ribose-glycated collagen is also used to mimic tissue glycation usually described as an indicator of aging. PSHG images are analyzed using a generic approach of the molecular disorder information in collagen fibrils, revealing significant changes upon aging, with a direct correlation between molecular disorder and fibril diameters.

  6. Light Microsopy Module, International Space Station Premier Automated Microscope

    Science.gov (United States)

    Meyer, William V.; Sicker, Ronald J.; Chiaramonte, Francis P.; Brown, Daniel F.; O'Toole, Martin A.; Foster, William M.; Motil, Brian J.; Abbot-Hearn, Amber Ashley; Atherton, Arthur Johnson; Beltram, Alexander; hide

    2015-01-01

    The Light Microscopy Module (LMM) was launched to the International Space Station (ISS) in 2009 and began science operations in 2010. It continues to support Physical and Biological scientific research on ISS. During 2015, if all goes as planned, five experiments will be completed: [1] Advanced Colloids Experiments with a manual sample base -3 (ACE-M-3), [2] the Advanced Colloids Experiment with a Heated Base -1 (ACE-H-1), [3] (ACE-H-2), [4] the Advanced Plant Experiment -03 (APEX-03), and [5] the Microchannel Diffusion Experiment (MDE). Preliminary results, along with an overview of present and future LMM capabilities will be presented; this includes details on the planned data imaging processing and storage system, along with the confocal upgrade to the core microscope. [1] New York University: Paul Chaikin, Andrew Hollingsworth, and Stefano Sacanna, [2] University of Pennsylvania: Arjun Yodh and Matthew Gratale, [3] a consortium of universities from the State of Kentucky working through the Experimental Program to Stimulate Competitive Research (EPSCoR): Stuart Williams, Gerold Willing, Hemali Rathnayake, et al., [4] from the University of Florida and CASIS: Anna-Lisa Paul and Rob Ferl, and [5] from the Methodist Hospital Research Institute from CASIS: Alessandro Grattoni and Giancarlo Canavese.

  7. Light microscope observations on the epididymis of paca (Agouti paca).

    Science.gov (United States)

    Schimming, Bruno Cesar; Machado, Márcia Rita Fernandes; Simões, Karina; da Cruz, Claudinei; Domeniconi, Raquel Fantin

    2013-01-01

    The features of paca epididymis, based on its appearance in light microscope, is described in this paper. The cellular population of the epithelial lining comprises principal cells, basal cells, apical cells, narrows cells, and hallo cells. The epididymis is divided in five distinct and continuous regions, Zone I, or initial segment, and zone II, are both localized into the head. Zone III comprises the distal head and all the body. Zones IV and V are restricted to the tail, in the proximal and distal cauda epididymis respectively. Each zone can be readily distinguished on the basis of morphological characteristics. The height of epididymal epithelium is greater in zone I. There is a progressive increase in the diameter of the tubular lumen through the different areas, with the maximum in the zone V. The presence of a high epithelium, and the virtual absence of sperm in zone I suggest fast transit of spermatozoa in this region. Zone V comprises the distal tail, has smaller epithelial lining, greater luminal diameter, shorter stereocilia than the other zones, and contains spermatozoa packed inside the lumen, that characterizes this zone as a place of sperm storage. The findings are compared with other reports in rodents and other domestic animals, to contribute to the understanding of epididymal morphophysiology.

  8. Spectral and spatial properties of polarized light reflections from the arms of squid (Loligo pealeii) and cuttlefish (Sepia officinalis L.).

    Science.gov (United States)

    Chiou, Tsyr-Huei; Mäthger, Lydia M; Hanlon, Roger T; Cronin, Thomas W

    2007-10-01

    On every arm of cuttlefish and squid there is a stripe of high-reflectance iridophores that reflects highly polarized light. Since cephalopods possess polarization vision, it has been hypothesized that these polarized stripes could serve an intraspecific communication function. We determined how polarization changes when these boneless arms move. By measuring the spectral and polarizing properties of the reflected light from samples at various angles of tilt and rotation, we found that the actual posture of the arm has little or no effect on partial polarization or the e-vector angle of the reflected light. However, when the illumination angle changed, the partial polarization of the reflected light also changed. The spectral reflections of the signals were also affected by the angle of illumination but not by the orientation of the sample. Electron microscope samples showed that these stripes are composed of several groups of multilayer platelets within the iridophores. The surface normal to each group is oriented at a different angle, which produces essentially constant reflection of polarized light over a range of viewing angles. These results demonstrate that cuttlefish and squid could send out reliable polarization signals to a receiver regardless of arm orientation.

  9. Automated calibration and control for polarization-resolved second harmonic generation on commercial microscopes.

    Science.gov (United States)

    Romijn, Elisabeth I; Finnøy, Andreas; Kumar, Rajesh; Lilledahl, Magnus B

    2018-01-01

    Polarization-resolved second harmonic generation (P-SHG) microscopy has evolved as a promising technique to reveal subresolution information about the structure and orientation of ordered biological macromolecules. To extend the adoption of the technique, it should be easily integrated onto commercial laser scanning microscopes. Furthermore, procedures for easy calibration and assessment of measurement accuracy are essential, and measurements should be fully automated to allow for analysis of large quantities of samples. In this paper we present a setup for P-SHG which is readily incorporated on commercial multiphoton microscopes. The entire system is completely automated which allows for rapid calibration through the freely available software and for automated imaging for different polarization measurements, including linear and circular polarization of the excitation beam. The results show that calibration settings are highly system dependent. We also show that the accuracy of the polarization control is easily quantified and that it varies between systems. The accuracy can be tuned by iterative alignment of optics or a more fine-grained calibration procedure. Images of real samples show that the red accuracy of the results is easily visualized with the automated setup. Through this system we believe that P-SHG could develop a wider adoption in biomedical applications.

  10. In situ scanning tunneling microscope tip treatment device for spin polarization imaging

    Science.gov (United States)

    Li, An-Ping [Oak Ridge, TN; Jianxing, Ma [Oak Ridge, TN; Shen, Jian [Knoxville, TN

    2008-04-22

    A tip treatment device for use in an ultrahigh vacuum in situ scanning tunneling microscope (STM). The device provides spin polarization functionality to new or existing variable temperature STM systems. The tip treatment device readily converts a conventional STM to a spin-polarized tip, and thereby converts a standard STM system into a spin-polarized STM system. The tip treatment device also has functions of tip cleaning and tip flashing a STM tip to high temperature (>2000.degree. C.) in an extremely localized fashion. Tip coating functions can also be carried out, providing the tip sharp end with monolayers of coating materials including magnetic films. The device is also fully compatible with ultrahigh vacuum sample transfer setups.

  11. Microscopic coupled-channels study of scattering and breakup of light heavy-ions

    International Nuclear Information System (INIS)

    Sakuragi, Yukinori; Yahiro, Masanobu; Kamimura, Masayasu.

    1987-01-01

    The elastic and inelastic scattering and the breakup reactions of light heavy-ions, particularly 6 Li, 7 Li and 12 C, are investigated on the basis of a microscopic coupled-channels method. The bound states and resonant and non-resonant continuum states of the projectile nucleus are taken into account. The wave functions of those states are given by a microscopic cluster model assuming α-d, α-t and 3α for the three projectile nuclei, respectively. The unbound continuum states are approximately treated with the method of coupled discretized continuum channels (CDCC). The real parts of all the diagonal and coupling potentials are given by doubly folding the M3Y effective nucleon-nucleon interaction into the nucleon transition densities of the projectile nucleus and the ground-state density of the target nucleus. The microscopic CDCC method is successfully applied to the analyses of the scattering and the breakup of 6,7 Li and 12 C in a wide range of the target mass and the bombarding energy. The effect of the projectile virtual breakup on the elastic scattering is strikingly large and absolutely important to reproduce the observed cross sections. The dynamical polarization (DP) potentials induced by the breakup of the 6,7 Li and 12 C projectiles are found to be strongly repulsive and, for 6 Li, very weakly absorptive, which is quite different from what has been known for DP potentials induced by the excitation of usual collective states. Unified understanding is presented for various types of possible DP potentials due to weak-coupling channels through strong-coupling channels. Further discussions are made on the roles of the coupling between the breakup channels and that between the elastic channel and the breakup channels in the scattering and breakup reactions of the light heavy-ions. (author)

  12. PHYSIOLOGICAL MECHANISMS OF POLARIZED LIGHT INFLUENCE ON PAIN

    Directory of Open Access Journals (Sweden)

    S. О. Gulyar

    2016-06-01

    Full Text Available There are presented experimental evidences of BIOPTRON device polarized light influence on the acupuncture points and pain locus. It is proved that PILER-light can induce analgesia which depends on the choice of the application zone, exposure and nature of pain (tonic, acute or visceral. Analgesic response has systemic character and is accompanied by participation of opioidergic nociceptive system

  13. PHYSIOLOGICAL MECHANISMS OF POLARIZED LIGHT INFLUENCE ON PAIN

    OpenAIRE

    S. О. Gulyar; Z. А. Tamarova

    2016-01-01

    There are presented experimental evidences of BIOPTRON device polarized light influence on the acupuncture points and pain locus. It is proved that PILER-light can induce analgesia which depends on the choice of the application zone, exposure and nature of pain (tonic, acute or visceral). Analgesic response has systemic character and is accompanied by participation of opioidergic nociceptive system

  14. Angle-dependent rotation of calcite in elliptically polarized light

    Science.gov (United States)

    Herne, Catherine M.; Cartwright, Natalie A.; Cattani, Matthew T.; Tracy, Lucas A.

    2017-08-01

    Calcite crystals trapped in an elliptically polarized laser field exhibit intriguing rotational motion. In this paper, we show measurements of the angle-dependent motion, and discuss how the motion of birefringent calcite can be used to develop a reliable and efficient process for determining the polarization ellipticity and orientation of a laser mode. The crystals experience torque in two ways: from the transfer of spin angular momentum (SAM) from the circular polarization component of the light, and from a torque due to the linear polarization component of the light that acts to align the optic axis of the crystal with the polarization axis of the light. These torques alternatingly compete with and amplify each other, creating an oscillating rotational crystal velocity. We model the behavior as a rigid body in an angle-dependent torque. We experimentally demonstrate the dependence of the rotational velocity on the angular orientation of the crystal by placing the crystals in a sample solution in our trapping region, and observing their behavior under different polarization modes. Measurements are made by acquiring information simultaneously from a quadrant photodiode collecting the driving light after it passes through the sample region, and by imaging the crystal motion onto a camera. We finish by illustrating how to use this model to predict the ellipticity of a laser mode from rotational motion of birefringent crystals.

  15. Multiple scattering of polarized light in a turbid medium

    International Nuclear Information System (INIS)

    Gorodnichev, E. E.; Kuzovlev, A. I.; Rogozkin, D. B.

    2007-01-01

    It is shown that multiple scattering of polarized light in a turbid medium can be represented as independent propagation of three basic modes: intensity and linearly and circularly polarized modes. Weak interaction between the basic modes can be described by perturbation theory and gives rise to 'overtones' (additional polarization modes). Transport equations for the basic and additional modes are derived from a vector radiative transfer equation. Analytical solutions to these equations are found in the practically important cases of diffusive light propagation and small-angle multiple scattering. The results obtained are in good agreement with experimental and numerical results and provide an explanation for the experimentally observed difference in depolarization between linearly and circularly polarized waves

  16. Broadband asymmetric waveguiding of light without polarization limitations.

    Science.gov (United States)

    Xu, Yadong; Gu, Chendong; Hou, Bo; Lai, Yun; Li, Jensen; Chen, Huanyang

    2013-01-01

    Optical diodes are fundamental elements for optical computing and information processing. Attempts to realize such non-reciprocal propagation of light by breaking the time-reversal symmetry include using indirect interband photonic transitions, the magneto-optical effect, optical nonlinearity or photonic crystals. Alternatively, asymmetric reciprocal transmission of light has been proposed in photonic metamaterial structures for either circularly or linearly polarized waves. Here we employ the recent concept of gradient index metamaterials to demonstrate a waveguide with asymmetric propagation of light, independent of polarization. The device blocks both transverse electric and magnetic polarized modes in one direction but transmits them in the other for a broadband spectrum. Unlike previous works using chiral properties of metamaterials, our device is based on the principle of momentum symmetry breaking at interfaces with phase discontinuities. Experiments in the microwave region verify our findings, which may pave the way to feasible passive optical diodes.

  17. On the polarization of light in atmospheres and oceans

    Science.gov (United States)

    Yang, P.; Kattawar, G. W.; Mishchenko, M. I.

    2016-12-01

    In this talk, we will briefly review the genesis and evolution of the polarization of light, dating back to the Vikings' questionable use of sunstones for navigation. Also to be presented are the first use of polarimetry in the study of planetary atmospheres and stars as well as the latest results on the use of polarization by both terrestrial and marine organisms. In particular, our presentation will focus on the representation of the polarization characteristics of light in terms of the Stokes vector-Mueller matrix formalism. In addition, we will discuss the features of the polarization properties of nonspherical particles. Furthermore, we will illustrate the great potential of using the polarization properties of light in downstream applications, particularly remote sensing of the optical and microphysical properties of airborne dust and ice crystals. We will also show the effect of coherence of the illuminating source on the polarization properties of atmospheric particles since sunlight only has a lateral coherence length of roughly 60 μm.

  18. Giant vesicles (GV) in colloidal system under the optical polarization microscope (OPM).

    Science.gov (United States)

    Khalid, Khalisanni; Noh, Muhammad Azri Mohd; Khan, M Niyaz; Ishak, Ruzaina; Penney, Esther; Chowdhury, Zaira Zaman; Hamzah, Mohammad Hafiz; Othman, Maizatulnisa

    2017-09-01

    This paper discusses the unprecedented microscopic findings of micellar growth in colloidal system (CS) of catalyzed piperidinolysis of ionized phenyl salicylate (PS - ). The giant vesicles (GV) was observed under the optical polarization microscope (OPM) at [NaX]=0.1M where X=3-isopropC 6 H 4 O - . The conditions were rationalized from pseudo-first-order rate constant, k obs of PS - of micellar phase at 31.1×10 -3 s -1 reported in previous publication. The overall diameter of GV (57.6μm) in CS (CTABr/NaX/H 2 O)-catalyzed piperidinolysis (where X=3-isopropC 6 H 4 O) of ionized phenyl salicylate were found as giant unilamellar vesicles (GUV) and giant multilamellar vesicles (GMV). The findings were also validated by means of rheological analysis. Copyright © 2017 Elsevier Ltd. All rights reserved.

  19. Polarized backlight unit using a polarization-preserving light-redirecting film for improving luminance gain

    Science.gov (United States)

    Moon, Jeongmin; Lee, Sungrae; Oh, Kyunghwan

    2015-05-01

    We proposed and demonstrated a polarized backlight unit (BLU) configuration with a new light-redirecting film (LRF) to improve the luminance gain and light transmittance in liquid crystal displays. We combined a very low birefringence triacetyl cellulose (TAC) base layer with UV-cured prismatic patterns in a mass-producible process to demonstrate a polarization-preserving LRF. Detailed analyses of the states of polarization (SOP) through the LRF were reported. We also fabricated a 7-in. edge-lit BLU using the new LRF. We found that the light directing capability of the new LRF was equivalent to that of a conventional prism film whose base layer was a poly(ethylene terephthalate) (PET) film, and that the new LRF successfully suppressed random polarization changes of the transmitted light. Utilizing these new advantages, we obtained 68% transmittance through the polarizer over the BLU with the new LRF, which was about 1.3-fold that for the BLU with the conventional prism film (54%). We also obtained 127% luminance gain using the new LRF, which was equivalent to that of the conventional prism film. Here, the luminance gain is referred to as the amount of increase in luminance on the surface normal of the light-guiding plate without any film.

  20. Polarization-preserving confocal microscope for optical experiments in a dilution refrigerator with high magnetic field.

    Science.gov (United States)

    Sladkov, Maksym; Bakker, M P; Chaubal, A U; Reuter, D; Wieck, A D; van der Wal, C H

    2011-04-01

    We present the design and operation of a fiber-based cryogenic confocal microscope. It is designed as a compact cold-finger that fits inside the bore of a superconducting magnet, and which is a modular unit that can be easily swapped between use in a dilution refrigerator and other cryostats. We aimed at application in quantum optical experiments with electron spins in semiconductors and the design has been optimized for driving with and detection of optical fields with well-defined polarizations. This was implemented with optical access via a polarization maintaining fiber together with Voigt geometry at the cold finger, which circumvents Faraday rotations in the optical components in high magnetic fields. Our unit is versatile for use in experiments that measure photoluminescence, reflection, or transmission, as we demonstrate with a quantum optical experiment with an ensemble of donor-bound electrons in a thin GaAs film. © 2011 American Institute of Physics

  1. Polarized light improves cutaneous healing on diabetic rats

    Science.gov (United States)

    Ramalho, Luciana Maria Pedreira; Oliveira, Priscila Chagas; Marques, Aparecida Maria Cordeiro; Barbosa Pinheiro, Antonio L.

    2010-02-01

    The aim of this study was to evaluate the healing of 3rd degree burn on diabetic rats submitted or not to treatment with Polarized Light. Diabetes mellitus (Streptozotocin, 60mg/kg) was induced on 45 male Wistar albinus rats and a third degree burn (1.5× 1.5cm) was created in the dorsum of each animal under general anesthesia. After a regular quarantine period, the animals were randomly distributed into three groups as follows: G1: control (no treatment, n =15); G2: Polarized Light (λ=400-2000nm, 20J/cm2) and G3: Polarized Light (λ=400-2000nm, 40J/cm2). The phototherapy performed on group G2 was Polarized Light dose 20J/cm2 and G3 was Polarized Light dose 40J/cm2 (Bioptron®, λ400-2000 nm, 40mW; 2.4J/cm2 per minute; Φ +/- 5.5 cm; Bioptron AG, Monchaltorf, Switzerland). The phototherapy started immediately post-burning and was repeated daily until the day before the animal death. The energy was applied transcutaneously respecting the focal distance of 10cm as recommended by the manufacturer. The dose was 20 or 40J/cm2 (4min 15s or 8min.and 30s). At each time point chosen (7, 14, and 21 days post-burning) and following macroscopic examination, each animal was killed by an overdose of general anesthesia. Slides were stained with HE, Sirius Red, and CK AE1/AE3 antibody. Qualitative and semi-quantitative analyses were performed under light microscopy. The animals submitted to phototherapy (20J/cm2) showed significant differences on regards revascularization and epithelialization. The use of 20J/cm2 was effective on improving the healing of third degree buns on diabetic animals at both early and late stages of the repair.

  2. Light and electron microscope assessment of the lytic activity of ...

    African Journals Online (AJOL)

    Jane

    840 scanning electron microscope operating at 5.0 kV. Transmission electron microscopy (TEM). Thin sections of agar were made with a stainless blade and then were immersed in gluteraldehyde solution for 30 min. This was washed three times with 0.075 M phosphate buffer (15 min) and fixed with osmium tetroxide (1 h).

  3. Undulator based scanning microscope at the National Synchrotron Light Source

    International Nuclear Information System (INIS)

    Rarback, H.; Shu, D.; Ade, H.; Jacobsen, C.; Kirz, J.; McNulty, I.; Rosser, R.

    1986-01-01

    A second generation scanning soft x-ray microscope is under construction, designed to utilize the dramatic increase in source bightness available at the soft x-ray undulator. The new instrument is expected to reduce image acquisition time by a factor of about 100, and to improve resolution, stability, and reproducibility

  4. A high-resolution combined scanning laser and widefield polarizing microscope for imaging at temperatures from 4 K to 300 K.

    Science.gov (United States)

    Lange, M; Guénon, S; Lever, F; Kleiner, R; Koelle, D

    2017-12-01

    Polarized light microscopy, as a contrast-enhancing technique for optically anisotropic materials, is a method well suited for the investigation of a wide variety of effects in solid-state physics, as, for example, birefringence in crystals or the magneto-optical Kerr effect (MOKE). We present a microscopy setup that combines a widefield microscope and a confocal scanning laser microscope with polarization-sensitive detectors. By using a high numerical aperture objective, a spatial resolution of about 240 nm at a wavelength of 405 nm is achieved. The sample is mounted on a 4 He continuous flow cryostat providing a temperature range between 4 K and 300 K, and electromagnets are used to apply magnetic fields of up to 800 mT with variable in-plane orientation and 20 mT with out-of-plane orientation. Typical applications of the polarizing microscope are the imaging of the in-plane and out-of-plane magnetization via the longitudinal and polar MOKE, imaging of magnetic flux structures in superconductors covered with a magneto-optical indicator film via the Faraday effect, or imaging of structural features, such as twin-walls in tetragonal SrTiO 3 . The scanning laser microscope furthermore offers the possibility to gain local information on electric transport properties of a sample by detecting the beam-induced voltage change across a current-biased sample. This combination of magnetic, structural, and electric imaging capabilities makes the microscope a viable tool for research in the fields of oxide electronics, spintronics, magnetism, and superconductivity.

  5. Using a university characterization facility to educate the public about microscopes: light microscopes to SEM

    Science.gov (United States)

    Healy, Nancy; Henderson, Walter

    2015-10-01

    The National Nanotechnology Infrastructure Network (NNIN)1is an integrated partnership of 14 universities across the US funded by NSF to support nanoscale researchers. The NNIN education office is located at the Institute of Electronics and Nanotechnology at the Georgia Institute of Technology. At Georgia Tech we offer programs that integrate the facility and its resources to educate the public about nanotechnology. One event that has proved highly successful involves using microscopes in our characterization suite to educate a diverse audience about a variety of imaging instruments. As part of the annual Atlanta Science Festival (ATLSF)2 we provided an event entitled: "What's all the Buzz about Nanotechnology?" which was open to the public and advertised through a variety of methods by the ATLSF. During the event, we provided hands-on demos, cleanroom tours, and activities with three of our microscopes in our recently opened Imaging and Characterization Facility: 1. Keyence VHX-600 Digital Microscope; 2. Hitachi SU823 FE-SEM; and 3. Hitachi TM 3000. During the two hour event we had approximately 150 visitors including many families with school-aged children. Visitors were invited to bring a sample for scanning with the TM-3000. This paper will discuss how to do such an event, lessons learned, and visitor survey results.

  6. 3D adaptive optics in a light sheet microscope.

    Science.gov (United States)

    Bourgenot, Cyril; Saunter, Christopher D; Taylor, Jonathan M; Girkin, John M; Love, Gordon D

    2012-06-04

    We report on a single plane illumination microscope (SPIM) incorporating adaptive optics in the imaging arm. We show how aberrations can occur from the sample mounting tube and quantify the aberrations both experimentally and computationally. A wavefront sensorless approach was taken to imaging a green fluorescent protein (GFP) labelled transgenic zebrafish. We show improvements in image quality whilst recording a 3D "z-stack" and show how the aberrations come from varying depths in the fish.

  7. Enhancing the performance of the light field microscope using wavefront coding.

    Science.gov (United States)

    Cohen, Noy; Yang, Samuel; Andalman, Aaron; Broxton, Michael; Grosenick, Logan; Deisseroth, Karl; Horowitz, Mark; Levoy, Marc

    2014-10-06

    Light field microscopy has been proposed as a new high-speed volumetric computational imaging method that enables reconstruction of 3-D volumes from captured projections of the 4-D light field. Recently, a detailed physical optics model of the light field microscope has been derived, which led to the development of a deconvolution algorithm that reconstructs 3-D volumes with high spatial resolution. However, the spatial resolution of the reconstructions has been shown to be non-uniform across depth, with some z planes showing high resolution and others, particularly at the center of the imaged volume, showing very low resolution. In this paper, we enhance the performance of the light field microscope using wavefront coding techniques. By including phase masks in the optical path of the microscope we are able to address this non-uniform resolution limitation. We have also found that superior control over the performance of the light field microscope can be achieved by using two phase masks rather than one, placed at the objective's back focal plane and at the microscope's native image plane. We present an extended optical model for our wavefront coded light field microscope and develop a performance metric based on Fisher information, which we use to choose adequate phase masks parameters. We validate our approach using both simulated data and experimental resolution measurements of a USAF 1951 resolution target; and demonstrate the utility for biological applications with in vivo volumetric calcium imaging of larval zebrafish brain.

  8. Mapping microscopic order in plant and mammalian cells and tissues: novel differential polarization attachment for new generation confocal microscopes (DP-LSM)

    Science.gov (United States)

    Steinbach, G.; Pawlak, K.; Pomozi, I.; Tóth, E. A.; Molnár, A.; Matkó, J.; Garab, G.

    2014-03-01

    Elucidation of the molecular architecture of complex, highly organized molecular macro-assemblies is an important, basic task for biology. Differential polarization (DP) measurements, such as linear (LD) and circular dichroism (CD) or the anisotropy of the fluorescence emission (r), which can be carried out in a dichrograph or spectrofluorimeter, respectively, carry unique, spatially averaged information about the molecular organization of the sample. For inhomogeneous samples—e.g. cells and tissues—measurements on macroscopic scale are not satisfactory, and in some cases not feasible, thus microscopic techniques must be applied. The microscopic DP-imaging technique, when based on confocal laser scanning microscope (LSM), allows the pixel by pixel mapping of anisotropy of a sample in 2D and 3D. The first DP-LSM configuration, which, in fluorescence mode, allowed confocal imaging of different DP quantities in real-time, without interfering with the ‘conventional’ imaging, was built on a Zeiss LSM410. It was demonstrated to be capable of determining non-confocally the linear birefringence (LB) or LD of a sample and, confocally, its FDLD (fluorescence detected LD), the degree of polarization (P) and the anisotropy of the fluorescence emission (r), following polarized and non-polarized excitation, respectively (Steinbach et al 2009 Acta Histochem.111 316-25). This DP-LSM configuration, however, cannot simply be adopted to new generation microscopes with considerably more compact structures. As shown here, for an Olympus FV500, we designed an easy-to-install DP attachment to determine LB, LD, FDLD and r, in new-generation confocal microscopes, which, in principle, can be complemented with a P-imaging unit, but specifically to the brand and type of LSM.

  9. Mapping microscopic order in plant and mammalian cells and tissues: novel differential polarization attachment for new generation confocal microscopes (DP-LSM)

    International Nuclear Information System (INIS)

    Steinbach, G; Pawlak, K; Garab, G; Pomozi, I; Tóth, E A; Molnár, A; Matkó, J

    2014-01-01

    Elucidation of the molecular architecture of complex, highly organized molecular macro-assemblies is an important, basic task for biology. Differential polarization (DP) measurements, such as linear (LD) and circular dichroism (CD) or the anisotropy of the fluorescence emission (r), which can be carried out in a dichrograph or spectrofluorimeter, respectively, carry unique, spatially averaged information about the molecular organization of the sample. For inhomogeneous samples—e.g. cells and tissues—measurements on macroscopic scale are not satisfactory, and in some cases not feasible, thus microscopic techniques must be applied. The microscopic DP-imaging technique, when based on confocal laser scanning microscope (LSM), allows the pixel by pixel mapping of anisotropy of a sample in 2D and 3D. The first DP-LSM configuration, which, in fluorescence mode, allowed confocal imaging of different DP quantities in real-time, without interfering with the ‘conventional’ imaging, was built on a Zeiss LSM410. It was demonstrated to be capable of determining non-confocally the linear birefringence (LB) or LD of a sample and, confocally, its FDLD (fluorescence detected LD), the degree of polarization (P) and the anisotropy of the fluorescence emission (r), following polarized and non-polarized excitation, respectively (Steinbach et al 2009 Acta Histochem.111 316–25). This DP-LSM configuration, however, cannot simply be adopted to new generation microscopes with considerably more compact structures. As shown here, for an Olympus FV500, we designed an easy-to-install DP attachment to determine LB, LD, FDLD and r, in new-generation confocal microscopes, which, in principle, can be complemented with a P-imaging unit, but specifically to the brand and type of LSM. (paper)

  10. Mapping microscopic order in plant and mammalian cells and tissues: novel differential polarization attachment for new generation confocal microscopes (DP-LSM).

    Science.gov (United States)

    Steinbach, G; Pawlak, K; Pomozi, I; Tóth, E A; Molnár, A; Matkó, J; Garab, G

    2014-02-24

    Elucidation of the molecular architecture of complex, highly organized molecular macro-assemblies is an important, basic task for biology. Differential polarization (DP) measurements, such as linear (LD) and circular dichroism (CD) or the anisotropy of the fluorescence emission (r), which can be carried out in a dichrograph or spectrofluorimeter, respectively, carry unique, spatially averaged information about the molecular organization of the sample. For inhomogeneous samples-e.g. cells and tissues-measurements on macroscopic scale are not satisfactory, and in some cases not feasible, thus microscopic techniques must be applied. The microscopic DP-imaging technique, when based on confocal laser scanning microscope (LSM), allows the pixel by pixel mapping of anisotropy of a sample in 2D and 3D. The first DP-LSM configuration, which, in fluorescence mode, allowed confocal imaging of different DP quantities in real-time, without interfering with the 'conventional' imaging, was built on a Zeiss LSM410. It was demonstrated to be capable of determining non-confocally the linear birefringence (LB) or LD of a sample and, confocally, its FDLD (fluorescence detected LD), the degree of polarization (P) and the anisotropy of the fluorescence emission (r), following polarized and non-polarized excitation, respectively (Steinbach et al 2009 Acta Histochem.111 316-25). This DP-LSM configuration, however, cannot simply be adopted to new generation microscopes with considerably more compact structures. As shown here, for an Olympus FV500, we designed an easy-to-install DP attachment to determine LB, LD, FDLD and r, in new-generation confocal microscopes, which, in principle, can be complemented with a P-imaging unit, but specifically to the brand and type of LSM.

  11. Utility and safety of a novel surgical microscope laser light source.

    Science.gov (United States)

    Sato, Taku; Bakhit, Mudathir S; Suzuki, Kyouichi; Sakuma, Jun; Fujii, Masazumi; Murakami, Yuta; Ito, Yuhei; Sugano, Tetsuo; Saito, Kiyoshi

    2018-01-01

    Tissue injuries caused by the thermal effects of xenon light microscopes have previously been reported. Due to this, the development of a safe microscope light source became a necessity. A newly developed laser light source is evaluated regarding its effectiveness and safety as an alternative to conventional xenon light source. We developed and tested a new laser light source for surgical microscopes. Four experiments were conducted to compare xenon and laser lights: 1) visual luminance comparison, 2) luminous and light chromaticity measurements, 3) examination and analysis of visual fatigue, and 4) comparison of focal temperature elevation due to light source illumination using porcine muscle samples. Results revealed that the laser light could be used at a lower illumination value than the xenon light (p source is more efficient and safer than a conventional xenon light source. It lacks harmful ultraviolet waves, has a longer lifespan, a lower focal temperature than that of other light sources, a wide range of brightness and color production, and improved safety for the user's vision. Further clinical trials are necessary to validate the impact of this new light source on the patient's outcome and prognosis.

  12. A compact Airy beam light sheet microscope with a tilted cylindrical lens.

    Science.gov (United States)

    Yang, Zhengyi; Prokopas, Martynas; Nylk, Jonathan; Coll-Lladó, Clara; Gunn-Moore, Frank J; Ferrier, David E K; Vettenburg, Tom; Dholakia, Kishan

    2014-10-01

    Light-sheet imaging is rapidly gaining importance for imaging intact biological specimens. Many of the latest innovations rely on the propagation-invariant Bessel or Airy beams to form an extended light sheet to provide high resolution across a large field of view. Shaping light to realize propagation-invariant beams often relies on complex programming of spatial light modulators or specialized, custom made, optical elements. Here we present a straightforward and low-cost modification to the traditional light-sheet setup, based on the open-access light-sheet microscope OpenSPIM, to achieve Airy light-sheet illumination. This brings wide field single-photon light-sheet imaging to a broader range of endusers. Fluorescent microspheres embedded in agarose and a zebrafish larva were imaged to demonstrate how such a microscope can have a minimal footprint and cost without compromising on imaging quality.

  13. Can invertebrates see the e-vector of polarization as a separate modality of light?

    OpenAIRE

    Labhart, Thomas

    2016-01-01

    ABSTRACT The visual world is rich in linearly polarized light stimuli, which are hidden from the human eye. But many invertebrate species make use of polarized light as a source of valuable visual information. However, exploiting light polarization does not necessarily imply that the electric (e)-vector orientation of polarized light can be perceived as a separate modality of light. In this Review, I address the question of whether invertebrates can detect specific e-vector orientations in a ...

  14. Measurement of anchoring coefficient of homeotropically aligned nematic liquid crystal using a polarizing optical microscope in reflective mode

    Directory of Open Access Journals (Sweden)

    Sang-In Baek

    2015-09-01

    Full Text Available Although the homeotropic alignment of liquid crystals is widely used in LCD TVs, no easy method exists to measure its anchoring coefficient. In this study, we propose an easy and convenient measurement technique in which a polarizing optical microscope is used in the reflective mode with an objective lens having a low depth of focus. All measurements focus on the reflection of light near the interface between the liquid crystal and alignment layer. The change in the reflected light is measured by applying an electric field. We model the response of the director of the liquid crystal to the electric field and, thus, the change in reflectance. By adjusting the extrapolation length in the calculation, we match the experimental and calculated results and obtain the anchoring coefficient. In our experiment, the extrapolation lengths were 0.31 ± 0.04 μm, 0.32 ± 0.08 μm, and 0.23 ± 0.05 μm for lecithin, AL-64168, and SE-5662, respectively.

  15. Ventral polarization vision in tabanids: horseflies and deerflies (Diptera: Tabanidae) are attracted to horizontally polarized light

    Science.gov (United States)

    Horváth, Gábor; Majer, József; Horváth, Loránd; Szivák, Ildikó; Kriska, György

    2008-11-01

    Adult tabanid flies (horseflies and deerflies) are terrestrial and lay their eggs onto marsh plants near bodies of fresh water because the larvae develop in water or mud. To know how tabanids locate their host animals, terrestrial rendezvous sites and egg-laying places would be very useful for control measures against them, because the hematophagous females are primary/secondary vectors of some severe animal/human diseases/parasites. Thus, in choice experiments performed in the field we studied the behavior of tabanids governed by linearly polarized light. We present here evidence for positive polarotaxis, i.e., attraction to horizontally polarized light stimulating the ventral eye region, in both males and females of 27 tabanid species. The novelty of our findings is that positive polarotaxis has been described earlier only in connection with the water detection of some aquatic insects ovipositing directly into water. A further particularity of our discovery is that in the order Diptera and among blood-sucking insects the studied tabanids are the first known species possessing ventral polarization vision and definite polarization-sensitive behavior with known functions. The polarotaxis in tabanid flies makes it possible to develop new optically luring traps being more efficient than the existing ones based on the attraction of tabanids by the intensity and/or color of reflected light.

  16. Reversible Shaping of Microwells by Polarized Light Irradiation

    Directory of Open Access Journals (Sweden)

    Federica Pirani

    2017-01-01

    Full Text Available In the last years, stimuli-responsive polymeric materials have attracted great interest, due to their low cost and ease of structuration over large areas combined with the possibility to actively manipulate their properties. In this work, we propose a polymeric pattern of soft-imprinted microwells containing azobenzene molecules. The shape of individual elements of the pattern can be controlled after fabrication by irradiation with properly polarized light. By taking advantage of the light responsivity of the azobenzene compound, we demonstrate the possibility to reversibly modulate a contraction-expansion of wells from an initial round shape to very narrow slits. We also show that the initial shape of the microconcavities can be restored by flipping the polarization by 90°. The possibility to reversibly control the final shape of individual elements of structured surfaces offers the opportunity to engineer surface properties dynamically, thus opening new perspectives for several applications.

  17. Discovery of polarized light scattered by dust around Alpha Orionis

    Science.gov (United States)

    Mcmillan, R. S.; Tapia, S.

    1978-01-01

    Following the suggestion by Jura and Jacoby (1976), linearly polarized blue continuum starlight scattered by the dust shell around the M2 Iab star Alpha Orionis (Betelgeuse) has been discovered. The polarization has been traced in the NE, NW, SE, and SW directions and has positive (tangential) orientation. Some asymmetry of the optical depth in the shell exists 15 and 30 arcsec from the star. In the NE direction the polarization was measured as far as 90 arcsec (17,000 AU) from the star. The dependence of the average intensity of the scattered light from the nebula on angular distance from the star is more consistent with an inverse-square density law than with inverse 1.5 or inverse-cube laws. Assuming that the density is proportional to the inverse square of distance from the star, the scattering optical depth in blue light along a radius of 0.03 arcsec is no more than 0.15 + or - 0.05. Future observations of the wavelength dependence of polarization will allow a determination of grain size.

  18. Pigmentosis tubae, a new entity: light and electron microscopic study

    International Nuclear Information System (INIS)

    Herrera, G.A.; Reimann, B.E.; Greenberg, H.L.; Miles, P.A.

    1983-01-01

    The authors noted an unusual finding in the fallopian tubes of a 31-year-old woman who had received external and internal whole pelvis radiotherapy for squamous cell carcinoma of the cervix. Aggregates of macrophages containing pigment, identified in a subepithelial location, were reminiscent of melanosis coli, which is caused by abuse of anthracene-containing laxatives. Electron microscopic examination of the pigment revealed cytoplasmic material with the appearance of lipofuscin, identical to the pigment described in cases of colonic melanosis. After a careful study of possible etiologic agents, it was concluded that the pigment most likely resulted from cellular damage caused by radiotherapy. The authors are not aware of any other reported case of this entity, which will be called pigmentosis tubae

  19. Optical-Fiber Fluorosensors With Polarized Light Sources

    Science.gov (United States)

    Egalon, Claudio O.; Rogowski, Robert S.

    1995-01-01

    Chemiluminescent and/or fluorescent molecules in optical-fiber fluorosensors oriented with light-emitting dipoles along transverse axis. Sensor of proposed type captures greater fraction of chemiluminescence or fluorescence and transmits it to photodetector. Transverse polarization increases sensitivity. Basic principles of optical-fiber fluorosensors described in "Making Optical-Fiber Chemical Sensors More Sensitive" (LAR-14525), "Improved Optical-Fiber Chemical Sensors" (LAR-14607), and "Improved Optical-Fiber Temperature Sensors" (LAR-14647).

  20. Efficacy of oral exfoliative cytology in diabetes mellitus patients: a light microscopic and confocal microscopic study.

    Science.gov (United States)

    Gopal, Deepika; Malathi, N; Reddy, B Thirupathi

    2015-03-01

    Diabetes mellitus (DM) has become a global problem. By monitoring the health status of these individuals, diabetic complications can be prevented. We aimed to analyze alterations in the morphology and cytomorphometry of buccal epithelial cells of type 2 DM patients using oral exfoliative cytology technique and determine its importance in public health screening, diagnosis and monitoring of diabetes mellitus. The study was carried out in 100 type 2 DM patients and 30 healthy individuals. Smears were taken from the right buccal mucosa and stained by the Papanicolaou technique. Staining with Acridine orange was carried out to view qualitative changes with confocal laser scanning microscope (LSM-510 Meta). The cytomorphometry was evaluated using IMAGE PRO PLUS 5.5 software with Evolution LC camera. All findings were statistically analyzed. The results showed that with increase in fasting plasma glucose levels, there is significant increase in nuclear area, decrease in cytoplasmic area, and increase in nuclear cytoplasmic ratio (p diabetes and aid in monitoring of diabetes throughout the lifetime of the patient.

  1. Light and electron microscope assessment of the lytic activity of ...

    African Journals Online (AJOL)

    The Microcystis cells were exposed to copper, B. mycoides B16 and Triton X-100, in order to ascertain the level of cell membrane damage. The membrane cell damage ... The electron microscopy observations appeared to reveal at least two mechanisms of Microcystis lysis (contact and parasitism). The light and electron ...

  2. Setting up a simple light sheet microscope for in toto imaging of C. elegans development.

    Science.gov (United States)

    Chardès, Claire; Mélénec, Pauline; Bertrand, Vincent; Lenne, Pierre-François

    2014-05-05

    Fast and low phototoxic imaging techniques are pre-requisite to study the development of organisms in toto. Light sheet based microscopy reduces photo-bleaching and phototoxic effects compared to confocal microscopy, while providing 3D images with subcellular resolution. Here we present the setup of a light sheet based microscope, which is composed of an upright microscope and a small set of opto-mechanical elements for the generation of the light sheet. The protocol describes how to build, align the microscope and characterize the light sheet. In addition, it details how to implement the method for in toto imaging of C. elegans embryos using a simple observation chamber. The method allows the capture of 3D two-colors time-lapse movies over few hours of development. This should ease the tracking of cell shape, cell divisions and tagged proteins over long periods of time.

  3. Super-resolution longitudinally polarized light needle achieved by tightly focusing radially polarized beams

    Science.gov (United States)

    Shi, Chang-kun; Nie, Zhong-quan; Tian, Yan-ting; Liu, Chao; Zhao, Yong-chuang; Jia, Bao-hua

    2018-01-01

    Based on the vector diffraction theory, a super-resolution longitudinally polarized optical needle with ultra-long depth of focus ( DOF) is generated by tightly focusing a radially polarized beam that is modulated by a self-designed ternary hybrid (phase/amplitude) filter (THF). Both the phase and the amplitude patterns of THF are judiciously optimized by the versatile particle swarm optimization (PSO) searching algorithm. For the focusing configuration with a combination of a high numerical aperture ( NA) and the optimized sine-shaped THFs, an optical needle with the full width at half maximum ( FWHM) of 0.414λ and the DOF of 7.58λ is accessed, which corresponds to an aspect ratio of 18.3. The demonstrated longitudinally polarized super-resolution light needle with high aspect ratio opens up broad applications in high-density optical data storage, nano-photolithography, super-resolution imaging and high-efficiency particle trapping.

  4. Microscopic vision modeling method by direct mapping analysis for micro-gripping system with stereo light microscope.

    Science.gov (United States)

    Wang, Yuezong; Zhao, Zhizhong; Wang, Junshuai

    2016-04-01

    We present a novel and high-precision microscopic vision modeling method, which can be used for 3D data reconstruction in micro-gripping system with stereo light microscope. This method consists of four parts: image distortion correction, disparity distortion correction, initial vision model and residual compensation model. First, the method of image distortion correction is proposed. Image data required by image distortion correction comes from stereo images of calibration sample. The geometric features of image distortions can be predicted though the shape deformation of lines constructed by grid points in stereo images. Linear and polynomial fitting methods are applied to correct image distortions. Second, shape deformation features of disparity distribution are discussed. The method of disparity distortion correction is proposed. Polynomial fitting method is applied to correct disparity distortion. Third, a microscopic vision model is derived, which consists of two models, i.e., initial vision model and residual compensation model. We derive initial vision model by the analysis of direct mapping relationship between object and image points. Residual compensation model is derived based on the residual analysis of initial vision model. The results show that with maximum reconstruction distance of 4.1mm in X direction, 2.9mm in Y direction and 2.25mm in Z direction, our model achieves a precision of 0.01mm in X and Y directions and 0.015mm in Z direction. Comparison of our model with traditional pinhole camera model shows that two kinds of models have a similar reconstruction precision of X coordinates. However, traditional pinhole camera model has a lower precision of Y and Z coordinates than our model. The method proposed in this paper is very helpful for the micro-gripping system based on SLM microscopic vision. Copyright © 2016 Elsevier Ltd. All rights reserved.

  5. Postirradiation changes in rat brain. Observations in light- and scanning microscope

    International Nuclear Information System (INIS)

    Kiczka-Wojczuk, J.; Sosnierz, M.; Bialas, B.; Wazna-Bogunska, C.

    1977-01-01

    Irradiation changes in central nervous system of the rat were evaluated. Fifty rats irradiated by a single dose of 1000 R were used. A special attention was paid to changes in ventricular ependyma. The changes observed in scanning microscope consisted of loss of cilia, swelling of ependymal cells and changes in their nuclear profiles. The changes presented in light microscope were typical for postirradiation damage of the brain. The authors express the opinion that scanning microscope offers a valuable, complementary tool for routine neuropathological investigations. (author)

  6. Switchable polarization rotation of visible light using a plasmonic metasurface

    Directory of Open Access Journals (Sweden)

    Stuart K. Earl

    2017-01-01

    Full Text Available A metasurface comprising an array of silver nanorods supported by a thin film of the phase change material vanadium dioxide is used to rotate the primary polarization axis of visible light at a pre-determined wavelength. The dimensions of the rods were selected such that, across the two phases of vanadium dioxide, the two lateral localized plasmon resonances (in the plane of the metasurface occur at the same wavelength. Illumination with linearly polarized light at 45° to the principal axes of the rod metasurface enables excitation of both of these resonances. Modulating the phase of the underlying substrate, we show that it is possible to reversibly switch which axis of the metasurface is resonant at the operating wavelength. Analysis of the resulting Stokes parameters indicates that the orientation of the principal linear polarization axis of the reflected signal is rotated by 90° around these wavelengths. Dynamic metasurfaces such as these have the potential to form the basis of an ultra-compact, low-energy multiplexer or router for an optical signal.

  7. Multiangular hyperspectral investigation of polarized light in case 2 waters

    Science.gov (United States)

    Tonizzo, A.; Zhou, J.; Gilerson, A.; Chowdhary, J.; Gross, B.; Moshary, F.; Ahmed, S.

    2009-09-01

    The focus of this work is on the dependence of in situ hyperspectral and multiangular polarized data on the size distribution and refractive index of the suspended particles. Underwater polarization measurements were obtained using a polarimeter developed at the Optical Remote Sensing Laboratory of the City College of New York, NY. The degree of polarization (DOP) of the underwater light field in coastal environments was measured and the water-leaving polarized radiance was derived. In-water optical properties were also measured with an ac-9 (WET Labs). Absorption and attenuation spectra are then used to derive information on the dissolved and suspend components in the water medium which are used in a vector radiative transfer code which provides the upwelling radiance. The model was run for various values of the refractive index of mineral particles until the modeled DOP matched the measured one. The relationship between the intensity of the maximum of the DOP and both the refractive index of the mineral particles and the shapes of their size distributions is analyzed in detail.

  8. Light and electron microscopic features of early and late phase radiation-induced proctitis

    International Nuclear Information System (INIS)

    Haboubi, N.Y.; Schofield, P.F.; Rowland, P.L.

    1988-01-01

    The light and electron microscopic features of rectal biopsies from 10 symptomatic patients treated with irradiation for pelvic malignancies are detailed. They are divided into two groups. Group I: biopsies taken during or shortly after the course of irradiation (six patients). Group II: biopsies taken 4 months or more after course completion (four patients). The distinguishing light microscopic features in the first group are epithelial meganucleosis, lack of mitotic activity, and patchy fibroblastic proliferation in the lamina propria. The blood vessels appear normal. In the second group, there are severe vascular changes characterized by narrowing of the arterioles by subintimal fibrosis, telangiectasia of capillaries and post-capillary venules, endothelial degeneration, and platelet thrombi formation. These vascular changes are always associated with severe fibrosis of the lamina propria and crypt distortion. The ultrastructural and light microscopic findings indicate that the cellular epithelial reaction and fibroblastic proliferation antedate the vascular injury, and the latter has no role in the acute phase reaction

  9. Ellipso-Microscopic Observation of Titanium Surface under UV-Light Irradiation

    International Nuclear Information System (INIS)

    Fushimi, K.; Kurauchi, K.; Nakanishi, T.; Hasegawa, Y.; Ueda, M.; Ohtsuka, T.

    2016-01-01

    The ellipso-microscopic observation of a titanium surface undergoing anodization in 0.05 mol dm -3 of H 2 SO 4 was conducted. During irradiation by ultra-violet (UV) light with a wavelength of 325 nm, the titanium surface allowed for the flow of a photo-induced current and showed up as a bright, patch-like image on an ellipso-microscopic view. The brightness and patch-pattern in the image changed with flowing photo-induced current. The changes in the brightness and the image corresponded to the formation and/or degradation of titanium oxide due to the photo-electrochemical reaction of the oxide. An in situ monitoring using the ellipso-microscope revealed that the film change was dependent on the irradiation light power, by UV-light increases the anodic current and results in the initiation of pitting at lower potentials as compared with the non-irradiated condition.

  10. Quantitative evaluation of a handheld light microscope for field diagnosis of soil-transmitted helminth infection.

    Science.gov (United States)

    Bogoch, Isaac I; Andrews, Jason R; Speich, Benjamin; Ame, Shaali M; Ali, Said M; Stothard, J Russell; Utzinger, Jürg; Keiser, Jennifer

    2014-12-01

    We evaluated the Newton Nm1, a commercially available handheld light microscope and compared it with conventional light microscopy for the diagnosis of soil-transmitted helminth infections. A total of 91 Kato-Katz thick smears were examined by experienced microscopists and helminth eggs were counted and expressed as eggs per gram of stool (EPG). Mean egg counts were significantly higher with the conventional light microscope (5,190 EPG versus 2,386 EPG for Ascaris lumbricoides; 826 versus 456 for Trichuris trichiura; both P Newton Nm1 microscope may be a useful tool for the detection and quantification of soil-transmitted helminth infection in clinical, epidemiologic, and public health settings. © The American Society of Tropical Medicine and Hygiene.

  11. AccessScope project: Accessible light microscope for users with upper limb mobility or visual impairments.

    Science.gov (United States)

    Mansoor, Awais; Ahmed, Wamiq M; Samarapungavan, Ala; Cirillo, John; Schwarte, David; Robinson, J Paul; Duerstock, Bradley S

    2010-01-01

    A web-based application was developed to remotely view slide specimens and control all functions of a research-level light microscopy workstation, called AccessScope. Students and scientists with upper limb mobility and visual impairments are often unable to use a light microscope by themselves and must depend on others in its operation. Users with upper limb mobility impairments and low vision were recruited to assist in the design process of the AccessScope personal computer (PC) user interface. Participants with these disabilities were evaluated in their ability to use AccessScope to perform microscopical tasks. AccessScope usage was compared with inspecting prescanned slide images by grading participants' identification and understanding of histological features and knowledge of microscope operation. With AccessScope subjects were able to independently perform common light microscopy functions through an Internet browser by employing different PC pointing devices or accessibility software according to individual abilities. Subjects answered more histology and microscope usage questions correctly after first participating in an AccessScope test session. AccessScope allowed users with upper limb or visual impairments to successfully perform light microscopy without assistance. This unprecedented capability is crucial for students and scientists with disabilities to perform laboratory coursework or microscope-based research and pursue science, technology, engineering, and mathematics fields.

  12. Photonic Heterostructures with Properties of Ferroelectrics and Light Polarizers

    Energy Technology Data Exchange (ETDEWEB)

    Palto, S. P., E-mail: palto@online.ru; Draginda, Yu. A. [Russian Academy of Sciences, Shubnikov Institute of Crystallography (Russian Federation)

    2010-11-15

    The optical and electro-optical properties of a new type of photonic heterostructure composed of alternating ferroelectric molecular layers and optically anisotropic layers of another material are considered. A numerical simulation of the real prototype of this heterostructure, which can be prepared by the Langmuir-Blodgett method from layers of a ferroelectric copolymer (polyvinylidene fluoride trifluoroethylene) and an azo dye with photoinduced optical anisotropy, has been performed. It is shown that this heterostructure has pronounced polarization optical properties and yields a significant change in the polarization state of light at the photonic band edges in the ranges of the maximum density of photon states. The latter property can be used to obtain an enhanced electro-optic effect at small spectral shifts of the photonic band (the latter can be provided by the piezoelectric effect in ferroelectric layers).

  13. Light Microscopy and Polarized Microscopy: A Dermatological Tool to Diagnose Gray Hair Syndromes.

    Science.gov (United States)

    Chandravathi, P L; Karani, Hetal Deepak; Siddaiahgari, Sirisha Rani; Lingappa, Lokesh

    2017-01-01

    Gray hair syndromes are rare syndromes which have an autosomal recessive inheritance and are characterized by pigmentary dilution of skin and hair, defects in immunological function, and nervous system defects. They comprise three disorders namely Chediak-Higashi syndrome (CHS), Griscelli syndrome (GPS), and Elejalde syndrome. Clinically, it is difficult to distinguish these disorders as their clinical features may overlap. Hence, to make a correct diagnosis and differentiate between CHS and GPS light microscopic examination of skin and hair shafts as well as peripheral blood smear evaluations should be done. In cases where the diagnosis is not possible chromosomal analysis for specific mutations can be done. In resource-poor settings where chromosomal analysis is not possible, and light microscopy findings are inconclusive, polarized microscopy can serve as a useful tool to distinguish between CHS and GPS. We report three cases with gray hair syndromes where the diagnosis on light microscopy and polarized microscopy of hair shaft correlated with the bone marrow examination findings and chromosomal analysis, thus emphasizing the importance of a noninvasive, cost-effective, and time-saving alternative in the diagnosis of these syndromes.

  14. Light microscope observation of circulating human lymphocytes cultured in vitro

    Directory of Open Access Journals (Sweden)

    Naila Francis Paulo de Oliveira

    2010-10-01

    Full Text Available The purpose of this work was to study the isolation and a light microscopy technique for cultured lymphocytes. Blood samples were obtained by venipuncture with an anticoagulant added and centrifuged in a Percoll density gradient to separate the leukocytes. Lymphocytes were placed in 25 cm ³ tissue culture flasks at 37ºC. After culturing, they were fixed and stained with the methods used for blood smears. Results showed that not all fixing solutions and stains were an equally good choice for cultured lymphocytes.Os linfócitos são células importantes do sistema imune e têm sido largamente utilizados em estudos morfológicos. Entretanto, a literatura sobre técnicas de preparação dessas células é escassa e antiga, especialmente para linfócitos cultivados in vitro. Portanto, o objetivo desse estudo foi relatar com detalhes as técnicas de isolamento e microscopia de luz de linfócitos mantidos em cultura. Amostras de sangue foram obtidas por punção venosa e centrifugadas em gradiente de densidade de Percoll, para separar os leucócitos. Os linfócitos foram mantidos em frascos de cultura de 25 cm³ a 37ºC. Após a cultura, as células foram fixadas e coradas de acordo com a metodologia utilizada para esfregaços sanguíneos. Nossos resultados mostraram que nem todos os fixadores e corantes utilizados para esfregaços sanguíneos são uma boa escolha para linfócitos cultivados in vitro.

  15. The ordinary light microscope: an appropriate tool for provisional detection and identification of crystals in synovial fluid.

    OpenAIRE

    Pascual, E; Tovar, J; Ruiz, M T

    1989-01-01

    To determine if the ordinary light microscope is a useful tool in the detection and identification of crystals in synovial fluid 63 fluids (13 with monosodium urate (MSU), 14 with calcium pyrophosphate dihydrate (CPPD), one with both types of crystal, and 35 without crystals) were examined blindly by two observers, first with an ordinary light microscope, then with a polarising light microscope. Tentative identification of the crystals by their shape was attempted. The sensitivity of the ordi...

  16. Real-Time Observation of Carbon Nanotube Etching Process Using Polarized Optical Microscope.

    Science.gov (United States)

    Zhao, Qiuchen; Yao, Fengrui; Wang, Zequn; Deng, Shibin; Tong, Lianming; Liu, Kaihui; Zhang, Jin

    2017-08-01

    Controllable synthesis of carbon nanotubes (CNTs) is of great importance in its further application, which attracts broad attention. As growth and etching are the two sides in the process of material crystallography and the control of the competition between them forms the foundation for modern technology of materials design and manufacture, the understanding on etching process of carbon nanotubes is still very unclear because technically it is of great challenge to characterize the dynamics in such small one-dimensional (1D) scale. Here the real-time investigation on the etching process of CNTs is reported, by the hot-wall chemical reactor equipped with a polarized optical microscope. It is discovered that the CNT etching behavior in air is totally of random, including the etching sites, termination sites, and structure dependence. Combining with the dynamic simulation, it is revealed that the random behavior reflects the unique "self-termination" phenomenon. A structure-independent etching propagation barrier of 2.4 eV is also obtained, which indicates that the etching propagation process still follows the conventional Kinetic Wulff construction theory. The results represent the new knowledge on the etching process in carbon nanotube and can contribute to its selective enrichment. Furthermore, the "self-termination" phenomenon may be a universal behavior in 1D process. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. Light microscopical demonstration and zonal distribution of parasinusoidal cells (Ito cells) in normal human liver

    DEFF Research Database (Denmark)

    Horn, T; Junge, Jette; Nielsen, O

    1988-01-01

    The parasinusoidal cells of the liver (Ito cells) were demonstrated light microscopically in autopsy specimens fixed in formalin and stained with Oil red O after dichromate treatment. The method allows examination of large samples containing numerous acini. Quantitative assessment showed a zonal...

  18. Carboxylic ester hydrolases in the thyroid gland of the guinea-pig. A light microscopic study

    DEFF Research Database (Denmark)

    Kirkeby, S

    1976-01-01

    The location of cholinesterase and non-specific esterase in the thyroid gland of the guniea-pig was studied with the light microscope. It was found that the idoxyl method for non-specific esterase activity under special conditions is superior to the cholinesterase method in a number of respects...

  19. Spin-polarized light-emitting diodes based on organic bipolar spin valves

    Energy Technology Data Exchange (ETDEWEB)

    Vardeny, Zeev Valentine; Nguyen, Tho Duc; Ehrenfreund, Eitan Avraham

    2017-10-25

    Spin-polarized organic light-emitting diodes are provided. Such spin-polarized organic light-emitting diodes incorporate ferromagnetic electrodes and show considerable spin-valve magneto-electroluminescence and magneto-conductivity responses, with voltage and temperature dependencies that originate from the bipolar spin-polarized space charge limited current.

  20. Evaluating fibre orientation dispersion in white matter: Comparison of diffusion MRI, histology and polarized light imaging.

    Science.gov (United States)

    Mollink, Jeroen; Kleinnijenhuis, Michiel; Cappellen van Walsum, Anne-Marie van; Sotiropoulos, Stamatios N; Cottaar, Michiel; Mirfin, Christopher; Heinrich, Mattias P; Jenkinson, Mark; Pallebage-Gamarallage, Menuka; Ansorge, Olaf; Jbabdi, Saad; Miller, Karla L

    2017-08-15

    Diffusion MRI is an exquisitely sensitive probe of tissue microstructure, and is currently the only non-invasive measure of the brain's fibre architecture. As this technique becomes more sophisticated and microstructurally informative, there is increasing value in comparing diffusion MRI with microscopic imaging in the same tissue samples. This study compared estimates of fibre orientation dispersion in white matter derived from diffusion MRI to reference measures of dispersion obtained from polarized light imaging and histology. Three post-mortem brain specimens were scanned with diffusion MRI and analyzed with a two-compartment dispersion model. The specimens were then sectioned for microscopy, including polarized light imaging estimates of fibre orientation and histological quantitative estimates of myelin and astrocytes. Dispersion estimates were correlated on region - and voxel-wise levels in the corpus callosum, the centrum semiovale and the corticospinal tract. The region-wise analysis yielded correlation coefficients of r = 0.79 for the diffusion MRI and histology comparison, while r = 0.60 was reported for the comparison with polarized light imaging. In the corpus callosum, we observed a pattern of higher dispersion at the midline compared to its lateral aspects. This pattern was present in all modalities and the dispersion profiles from microscopy and diffusion MRI were highly correlated. The astrocytes appeared to have minor contribution to dispersion observed with diffusion MRI. These results demonstrate that fibre orientation dispersion estimates from diffusion MRI represents the tissue architecture well. Dispersion models might be improved by more faithfully incorporating an informed mapping based on microscopy data. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

  1. Identification of crystals in Hanford nuclear waste using polarized light microscopy

    International Nuclear Information System (INIS)

    Herting, D.L.

    1984-09-01

    The use of polarized light microscopy for identifying crystals encountered in Rockwell Hanford Operations chemical studies is described. Identifying characteristics and full-color photographs are presented for crystals commonly found in Hanford Site nuclear waste, including sodium nitrate, sodium nitrite, sodium aluminate, sodium phosphate, sodium fluoride, ammonium heptafluorozirconate, sodium sulfate, sodium carbonate, and ammonium nitrate. These characteristics are described in terms of birefringence, extinction position, interference figure, sign of elongation, optic sign, and crystal morphology. Background information on crystal optics is presented so that these traits can be understood by the nonmicroscopist. Detailed operational instructions are given so that the novice microscope user can make the proper adjustments of the instrument to search for and observe the identifying features of the crystals

  2. Imaging the response of individual carbon nanotubes to polarized light in aqueous environments

    Science.gov (United States)

    Walker, Bryant; Brintlinger, Todd; Fuhrer, Michael S.; Cumings, John; Hobbie, Erik

    2007-03-01

    Individual carbon nanotubes are grown using chemical vapor deposition (methane-ethylene carrier gas and iron nitrate catalyst), freely suspended in an aqueous solution using a surfactant (sodium dodecyl sulfate), and imaged in an optical microscope using either fluorescent dye (PKH67 and PKH23) or intrinsic near-infrared fluorescence. Freely suspended, individual carbon nanotubes of length 1-8 micrometers show an increasing response to illuminating light as the polarization becomes parallel to tube axis. More intriguingly, some of the carbon nanotubes are found to collapse and fold under 10-30 seconds of illumination, with increasing tube length showing longer time-to-collapse. Unperturbed persistence lengths in these nanotubes are estimated to be 200-300 micrometers.

  3. Light microscopic distribution and electron microscopic identification of severely damaged cells in x-irradiated oral epithelium in rat

    International Nuclear Information System (INIS)

    Liu, H.M.; Meyer, J.; Waterhouse, J.P.

    1975-01-01

    After x irradiation with a single dose of 5000 R to the lower lip of shielded rats, the responses of the epithelium of the mucosa were studied at 2, 6, 26, and 50 hr by light and electron microscopy. Light microscopy showed sharp contrasts in the intensity of staining among the irradiated basal cells, and the presence of focally distributed dark cells. These were identified in the electron microscope as degenerating cells with condensed nuclear and cytoplasmic contents and degenerate organelles. Quantitative analysis of the pattern of distribution of dark cells revealed a marked increase in over-all frequency, pairing, and formation of larger clusters by 50 hr. At this time dark cells were 11.6 percent of the total number of the basal cells and the largest cluster consisted of 12 adjacent cells. The distribution of dark cells at 50 hr fitted the negative binomial distribution (goodness of fit, chi 2 = 5.03, p = 0.185) and showed significant clustering. The mechanism of pair and cluster formation is discussed. (U.S.)

  4. Automated image mosaics by non-automated light microscopes: the MicroMos software tool.

    Science.gov (United States)

    Piccinini, F; Bevilacqua, A; Lucarelli, E

    2013-12-01

    Light widefield microscopes and digital imaging are the basis for most of the analyses performed in every biological laboratory. In particular, the microscope's user is typically interested in acquiring high-detailed images for analysing observed cells and tissues, meanwhile being representative of a wide area to have reliable statistics. The microscopist has to choose between higher magnification factor and extension of the observed area, due to the finite size of the camera's field of view. To overcome the need of arrangement, mosaicing techniques have been developed in the past decades for increasing the camera's field of view by stitching together more images. Nevertheless, these approaches typically work in batch mode and rely on motorized microscopes. Or alternatively, the methods are conceived just to provide visually pleasant mosaics not suitable for quantitative analyses. This work presents a tool for building mosaics of images acquired with nonautomated light microscopes. The method proposed is based on visual information only and the mosaics are built by incrementally stitching couples of images, making the approach available also for online applications. Seams in the stitching regions as well as tonal inhomogeneities are corrected by compensating the vignetting effect. In the experiments performed, we tested different registration approaches, confirming that the translation model is not always the best, despite the fact that the motion of the sample holder of the microscope is apparently translational and typically considered as such. The method's implementation is freely distributed as an open source tool called MicroMos. Its usability makes building mosaics of microscope images at subpixel accuracy easier. Furthermore, optional parameters for building mosaics according to different strategies make MicroMos an easy and reliable tool to compare different registration approaches, warping models and tonal corrections. © 2013 The Authors Journal of

  5. An integrated single- and two-photon non-diffracting light-sheet microscope

    Science.gov (United States)

    Lau, Sze Cheung; Chiu, Hoi Chun; Zhao, Luwei; Zhao, Teng; Loy, M. M. T.; Du, Shengwang

    2018-04-01

    We describe a fluorescence optical microscope with both single-photon and two-photon non-diffracting light-sheet excitations for large volume imaging. With a special design to accommodate two different wavelength ranges (visible: 400-700 nm and near infrared: 800-1200 nm), we combine the line-Bessel sheet (LBS, for single-photon excitation) and the scanning Bessel beam (SBB, for two-photon excitation) light sheet together in a single microscope setup. For a transparent thin sample where the scattering can be ignored, the LBS single-photon excitation is the optimal imaging solution. When the light scattering becomes significant for a deep-cell or deep-tissue imaging, we use SBB light-sheet two-photon excitation with a longer wavelength. We achieved nearly identical lateral/axial resolution of about 350/270 nm for both imagings. This integrated light-sheet microscope may have a wide application for live-cell and live-tissue three-dimensional high-speed imaging.

  6. Measuring polarization dependent dispersion of non-polarizing beam splitter cubes with spectrally resolved white light interferometry

    Science.gov (United States)

    Csonti, K.; Hanyecz, V.; Mészáros, G.; Kovács, A. P.

    2017-06-01

    In this work we have measured the group-delay dispersion of an empty Michelson interferometer for s- and p-polarized light beams applying two different non-polarizing beam splitter cubes. The interference pattern appearing at the output of the interferometer was resolved with two different spectrometers. It was found that the group-delay dispersion of the empty interferometer depended on the polarization directions in case of both beam splitter cubes. The results were checked by inserting a glass plate in the sample arm of the interferometer and similar difference was obtained for the two polarization directions. These results show that to reach high precision, linearly polarized white light beam should be used and the residual dispersion of the empty interferometer should be measured at both polarization directions.

  7. Adaptive illumination based on direct wavefront sensing in a light-sheet fluorescence microscope.

    Science.gov (United States)

    Wilding, Dean; Pozzi, Paolo; Soloviev, Oleg; Vdovin, Gleb; Verhaegen, Michel

    2016-10-31

    A methodology for the adaptive control and correction of phase aberrations in the illumination arm of a light-sheet fluorescence microscope has been developed. The method uses direct wavefront sensing on epi-fluorescent light to detect the aberration present in the sample. Using this signal, the aberrations in the illumination arm are subsequently corrected with a spatial light modulator in a feedforward mode. Adaptive correction, resulting in significant improvement in the axial resolution, has been demonstrated by imaging Tg(fli:GFP) zebrafish embryos.

  8. Three-dimensional visualization system for ophthalmic microscopes using visible light and near-infrared illumination.

    Science.gov (United States)

    Kwon, Ki-Chul; Im, Chan Young; Seo, Kyoung Yul; Nam, Sang Min; Erdenebat, Munkh-Uchral; Shim, Young Bo; Han, Young-Geun; Kim, Nam

    2018-02-01

    In this paper, we describe a three-dimensional visualization system for ophthalmic microscopes that is aimed at microsurgery without the eyepieces. A three-dimensional visualization system for ophthalmic microscopes using the mixed illumination, which consists of visible light and near-infrared illumination, is established in order to acquire more exact information of object and reduce the amount of light irradiated to the patients, and its usage in microsurgery without eyepieces is herein described. A custom-designed stereoscopic three-dimensional display which is manufactured for the convenience of the surgeons during the long-time surgery, is connected directly to the camera of the ophthalmic microscope in order to eliminate the discomfort of eyepieces to the surgeon and signal delay between the camera, mounted on the microscope, and display device for surgeon. The main features of the established system are the signal delay-free for surgeon and the low level of illumination for patient. In particular, it could significantly reduce the amount of light irradiated on a patient's eye via NIR illumination. Upon comparison with the conventional system during clinical ophthalmology trials, this system is confirmed to require almost the same operation time and reduced discomfort and eyestrain during long periods of observation. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. Does Synergism in Microscopic Polarity Correlate with Extrema in Macroscopic Properties for Aqueous Mixtures of Dipolar Aprotic Solvents?

    Science.gov (United States)

    Duereh, Alif; Sato, Yoshiyuki; Smith, Richard Lee; Inomata, Hiroshi; Pichierri, Fabio

    2017-06-22

    Aqueous mixtures of dipolar aprotic solvents (acetonitrile, γ-valerolactone, γ-butyrolactone, tetrahydrofuran, 1,4-dioxane, acetone, pyridine, N-methyl-2-pyrrolidone, N,N-dimethylformamide, N,N-dimethylacetamide, and dimethyl sulfoxide) show synergism in microscopic polarity and extrema in macroscopic viscosity (η) and molar excess enthalpy (H E ) in water-rich compositions that correlate with solvent functional group electrostatic basicity (β 2 H ). Microscopic polarities of aqueous solvent mixtures were estimated by measuring the spectral shift (λ max ) of 4-nitroaniline with UV-vis spectroscopy at 25 °C. Dynamic viscosities (η) and densities were measured for eight aqueous dipolar aprotic mixtures over the full range of compositions at (25 to 45) °C. The λ max , η, and H E values of the aqueous mixtures showed a linear trend with increasing electrostatic basicity of the solvent functional groups that is attributed to the size and strength of the hydration shell of water. Density functional theory (DFT) calculations were performed for 1:3 complexes (solvent: (H 2 O) 3 ) and it was found that aqueous mixtures with high basicity have high binding energies and short hydrogen bonding distances implying that the size and strength of the hydration shell of water is proportional to functional group basicity. Consideration of functional group basicity of dipolar aprotic solvents allows one to relate synergism in microscopic polarity to extrema in macroscopic properties for a wide range of aqueous dipolar aprotic solvent mixtures.

  10. Performance comparison of polarized white light emitting diodes using wire-grid polarizers with polymeric and glass substrates

    Science.gov (United States)

    Su, Jung-Chieh; Chou, Shih-Chieh

    2018-03-01

    Polarized white light emitting diodes (WLEDs) packaged with reflective metal wire-grid polarizer of polymeric and glass substrates were investigated. The performance comparison of polymeric wire-grid polarizer film (WGF) and nano wire-grid polarizer (NWGP) with glass substrate was evaluated. The transverse electric field (TE) polarization transmittance of WGF is less than that of NWGP due to its smaller grid parameters. Despite of the higher duty cycle of WGF, the angular-dependent extinction ratio (ER) of the polarized WLEDs (PWLEDs) with WGF is higher than that of with NWGP. Regarding increasing drive currents, the PWLEDs with NWGP had better color stability than that with WGF due to better substrate thermal stability. In summary, linewidth, period and substrate material are the crucial factors for the PWLED packaging using wire grid polarizer.

  11. Polarization characteristics of radiation in both 'light' and conventional undulators

    Science.gov (United States)

    Potylitsyn, A. P.; Kolchuzhkin, A. M.; Strokov, S. A.

    2017-07-01

    As a rule, an intensity spectrum of undulator radiation (UR) is calculated by using the classical approach, even for electron energy higher than 10 GeV. Such a spectrum is determined by an electron trajectory in an undulator while neglecting radiation loss. Using Planck's law, the UR photon spectrum can be calculated from the obtained intensity spectrum, for both linear and nonlinear regimes. The electron radiation process in a field of strong electromagnetic waves is considered within the quantum electrodynamics framework, using the Compton scattering process or radiation in a 'light' undulator. A comparison was made of the results from using these two approaches, for UR spectra generated by 250-GeV electrons in an undulator with a 11.5-mm period; this comparison shows that they coincide with high accuracy. The characteristics of the collimated UR beam (i.e. spectrum and circular polarization) were simulated while taking into account the discrete process of photon emission along an electron trajectory in both undulator types. Both spectral photon distributions and polarization dependence on photon energy are 'smoothed', in comparison to that expected for a long undulator-the latter of which considers the ILC positron source (ILC Technical Design Report).

  12. Quantitative polarized light microscopy of unstained mammalian cochlear sections

    Science.gov (United States)

    Kalwani, Neil M.; Ong, Cheng Ai; Lysaght, Andrew C.; Haward, Simon J.; McKinley, Gareth H.; Stankovic, Konstantina M.

    2013-02-01

    Hearing loss is the most common sensory deficit in the world, and most frequently it originates in the inner ear. Yet, the inner ear has been difficult to access for diagnosis because of its small size, delicate nature, complex three-dimensional anatomy, and encasement in the densest bone in the body. Evolving optical methods are promising to afford cellular diagnosis of pathologic changes in the inner ear. To appropriately interpret results from these emerging technologies, it is important to characterize optical properties of cochlear tissues. Here, we focus on that characterization using quantitative polarized light microscopy (qPLM) applied to unstained cochlear sections of the mouse, a common animal model of human hearing loss. We find that the most birefringent cochlear materials are collagen fibrils and myelin. Retardance of the otic capsule, the spiral ligament, and the basilar membrane are substantially higher than that of other cochlear structures. Retardance of the spiral ligament and the basilar membrane decrease from the cochlear base to the apex, compared with the more uniform retardance of other structures. The intricate structural details revealed by qPLM of unstained cochlear sections ex vivo strongly motivate future application of polarization-sensitive optical coherence tomography to human cochlea in vivo.

  13. Theory and analysis of a large field polarization imaging system with obliquely incident light.

    Science.gov (United States)

    Lu, Xiaotian; Jin, Weiqi; Li, Li; Wang, Xia; Qiu, Su; Liu, Jing

    2018-02-05

    Polarization imaging technology provides information about not only the irradiance of a target but also the polarization degree and angle of polarization, which indicates extensive application potential. However, polarization imaging theory is based on paraxial optics. When a beam of obliquely incident light passes an analyser, the direction of light propagation is not perpendicular to the surface of the analyser and the applicability of the traditional paraxial optical polarization imaging theory is challenged. This paper investigates a theoretical model of a polarization imaging system with obliquely incident light and establishes a polarization imaging transmission model with a large field of obliquely incident light. In an imaging experiment with an integrating sphere light source and rotatable polarizer, the polarization imaging transmission model is verified and analysed for two cases of natural light and linearly polarized light incidence. Although the results indicate that the theoretical model is consistent with the experimental results, the theoretical model distinctly differs from the traditional paraxial approximation model. The results prove the accuracy and necessity of the theoretical model and the theoretical guiding significance for theoretical and systematic research of large field polarization imaging.

  14. Differential response to circularly polarized light by the jewel scarab beetle Chrysina gloriosa.

    Science.gov (United States)

    Brady, Parrish; Cummings, Molly

    2010-05-01

    Circularly polarized light is rare in the terrestrial environment, and cuticular reflections from scarab beetles are one of the few natural sources. Chrysina gloriosa LeConte 1854, a scarab beetle found in montane juniper forests of the extreme southwestern United States and northern Mexico, are camouflaged in juniper foliage; however, when viewed with right circularly polarizing filters, the beetles exhibit a stark black contrast. Given the polarization-specific changes in the appearance of C. gloriosa, we hypothesized that C. gloriosa can detect circularly polarized light. We tested for phototactic response and differential flight orientation of C. gloriosa toward different light stimuli. Chrysina gloriosa exhibited (a) positive phototaxis, (b) differential flight orientation between linear and circularly polarized light stimuli of equal intensities, and (c) discrimination between circularly polarized and unpolarized lights of different intensities consistent with a model of circular polarization sensitivity based on a quarter-wave plate. These results demonstrate that C. gloriosa beetles respond differentially to circularly polarized light. In contrast, Chrysina woodi Horn 1885, a close relative with reduced circularly polarized reflection, exhibited no phototactic discrimination between linear and circularly polarized light. Circularly polarized sensitivity may allow C. gloriosa to perceive and communicate with conspecifics that remain cryptic to predators, reducing indirect costs of communication.

  15. A multi-modal stereo microscope based on a spatial light modulator.

    Science.gov (United States)

    Lee, M P; Gibson, G M; Bowman, R; Bernet, S; Ritsch-Marte, M; Phillips, D B; Padgett, M J

    2013-07-15

    Spatial Light Modulators (SLMs) can emulate the classic microscopy techniques, including differential interference (DIC) contrast and (spiral) phase contrast. Their programmability entails the benefit of flexibility or the option to multiplex images, for single-shot quantitative imaging or for simultaneous multi-plane imaging (depth-of-field multiplexing). We report the development of a microscope sharing many of the previously demonstrated capabilities, within a holographic implementation of a stereo microscope. Furthermore, we use the SLM to combine stereo microscopy with a refocusing filter and with a darkfield filter. The instrument is built around a custom inverted microscope and equipped with an SLM which gives various imaging modes laterally displaced on the same camera chip. In addition, there is a wide angle camera for visualisation of a larger region of the sample.

  16. Angular structure of light polarization and singularities in transmittance of nematic liquid crystal cells

    Science.gov (United States)

    Kiselev, Alexei D.; Vovk, Roman G.; Buinyi, Igor O.; Soskin, Marat S.

    2007-06-01

    We study the angular structure of polarization of light transmitted through a nematic liquid crystal (NLC) cell by analyzing the polarization state as a function of the incidence angles. Our theoretical results are obtained by evaluating the Stokes parameters that characterize the polarization state of plane waves propagating through the NLC layer at varying direction of incidence. Using the Stokes polarimetry technique we carried out the measurements of the polarization resolved conoscopic patterns emerging after the homeotropically aligned NLC cell illuminated by the convergent light beam. The resulting polarization resolved angular patterns are described both theoretically and experimentally in terms of the polarization singularities such as C-points (points of circular polarization) and L-lines (lines of linear polarization). When the ellipticity of the incident light varies, the angular patterns are found to undergo transformations involving the processes of creation and annihilation of the C-points.

  17. From Animaculum to single molecules: 300 years of the light microscope.

    Science.gov (United States)

    Wollman, Adam J M; Nudd, Richard; Hedlund, Erik G; Leake, Mark C

    2015-04-01

    Although not laying claim to being the inventor of the light microscope, Antonj van Leeuwenhoek (1632-1723) was arguably the first person to bring this new technological wonder of the age properly to the attention of natural scientists interested in the study of living things (people we might now term 'biologists'). He was a Dutch draper with no formal scientific training. From using magnifying glasses to observe threads in cloth, he went on to develop over 500 simple single lens microscopes (Baker & Leeuwenhoek 1739 Phil. Trans. 41, 503-519. (doi:10.1098/rstl.1739.0085)) which he used to observe many different biological samples. He communicated his finding to the Royal Society in a series of letters (Leeuwenhoek 1800 The select works of Antony Van Leeuwenhoek, containing his microscopical discoveries in many of the works of nature, vol. 1) including the one republished in this edition of Open Biology. Our review here begins with the work of van Leeuwenhoek before summarizing the key developments over the last ca 300 years, which has seen the light microscope evolve from a simple single lens device of van Leeuwenhoek's day into an instrument capable of observing the dynamics of single biological molecules inside living cells, and to tracking every cell nucleus in the development of whole embryos and plants.

  18. From Animaculum to single molecules: 300 years of the light microscope

    Science.gov (United States)

    Wollman, Adam J. M.; Nudd, Richard; Hedlund, Erik G.; Leake, Mark C.

    2015-01-01

    Although not laying claim to being the inventor of the light microscope, Antonj van Leeuwenhoek (1632–1723) was arguably the first person to bring this new technological wonder of the age properly to the attention of natural scientists interested in the study of living things (people we might now term ‘biologists’). He was a Dutch draper with no formal scientific training. From using magnifying glasses to observe threads in cloth, he went on to develop over 500 simple single lens microscopes (Baker & Leeuwenhoek 1739 Phil. Trans. 41, 503–519. (doi:10.1098/rstl.1739.0085)) which he used to observe many different biological samples. He communicated his finding to the Royal Society in a series of letters (Leeuwenhoek 1800 The select works of Antony Van Leeuwenhoek, containing his microscopical discoveries in many of the works of nature, vol. 1) including the one republished in this edition of Open Biology. Our review here begins with the work of van Leeuwenhoek before summarizing the key developments over the last ca 300 years, which has seen the light microscope evolve from a simple single lens device of van Leeuwenhoek's day into an instrument capable of observing the dynamics of single biological molecules inside living cells, and to tracking every cell nucleus in the development of whole embryos and plants. PMID:25924631

  19. Oral leukoplakia: Transmission electron microscopic correlation with clinical types and light microscopy

    Science.gov (United States)

    Tamgadge, Sandhya Avinash; Ganvir, Sindhu Milind; Hazarey, Vinay Krishnarao; Tamgadge, Avinash

    2012-01-01

    Background: Leukoplakia, is a precancerous lesion that is most commonly encountered in the oral cavity. The grade of dysplasia is presumed to be the most important indicator of malignant potential. There are many promising aspects in advanced methods for the evaluation of oral precancer and cancer. Among these methods, electron microscopic examination predicts the true biologic potential more accurately than conventional histology and has some success in the early detection of potentially malignant lesions. It has been reported in the literature that there is some correlation between clinical, histopathological, and transmission electron microscopic features. Materials and Methods: In this cohort study (prospective research), from the total of 9 subjects, 3 had homogenous leukoplakia, 3 had ulcerative type of oral leukoplakia, and 3 had nodular type of oral leukoplakia. Two patients were selected as control patients. Transmission electron microscopic examination was carried for all the cases and controls. All the findings were correlated with clinical features and light microscopy. Results: Clinically and histologically, mild leukoplakia showed break in basement membrane, which can only be observed under transmission electron microscope (TEM). Additional dysplastic features were observed under transmission electron microscope, which are indicative of neoplastic process. Conclusions: Thus, it is finally concluded that nodular leukoplakia seems to be the most severe clinical type of leukoplakia showing highest risk of malignant transformation. Homogenous leukoplakia might show break in basement membrane under TEM. PMID:23814570

  20. Polarization-resolved angular patterns of nematic liquid crystal cells: Topological events driven by incident light polarization

    Science.gov (United States)

    Kiselev, Alexei D.; Vovk, Roman G.; Egorov, Roman I.; Chigrinov, Vladimir G.

    2008-09-01

    We study the angular structure of polarization of light transmitted through a nematic liquid crystal (NLC) cell by analyzing the polarization state as a function of the incidence angles and the polarization of the incident wave. The polarization-resolved angular (conoscopic) patterns emerging after the NLC cell illuminated by the convergent light beam are described in terms of the polarization singularities such as C points (points of circular polarization) and L lines (lines of linear polarization). For the homeotropically aligned cell, the Stokes polarimetry technique is used to measure the polarization resolved conoscopic patterns at different values of the ellipticity of the incident light, γell(inc) , impinging onto the cell. Using the exact analytical expressions for the transfer matrix we show that variations of the ellipticity, γell(inc) , induce transformations of the angular pattern exhibiting the effect of avoided L -line crossings and characterized by topological events such as creation and annihilation of the C points. The predictions of the theory are found to be in good agreement with the experimental results.

  1. The scanning transmission microscope at the NSLS [National Synchrotron Light Source

    International Nuclear Information System (INIS)

    Rarback, H.; Buckley, C.; Goncz, K.

    1989-01-01

    The scanning transmission soft x-ray microscope (STXM), that has been under development at the National Synchrotron Light Source has been substantially upgraded for operation with the X1 undulator. The principal new features are: optical prefocusing, using a visible light interferometer, a dedicated VAXstation 3200 with a more user friendly and flexible software system for image acquisition and analysis, a flow cell that makes it possible not only to keep the specimen wet during exposure, but to change the fluid around the specimen as well, and a more compact proportional counter that is capable of counting rates of several MHz. In conjunction with new zone plates of better resolution and higher efficiency, the microscope is ready for a period of extended use in biological imaging. 9 refs., 6 figs

  2. A Simple low-cost device enables four epi-illumination techniques on standard light microscopes.

    Science.gov (United States)

    Ishmukhametov, Robert R; Russell, Aidan N; Wheeler, Richard J; Nord, Ashley L; Berry, Richard M

    2016-02-08

    Back-scattering darkfield (BSDF), epi-fluorescence (EF), interference reflection contrast (IRC), and darkfield surface reflection (DFSR) are advanced but expensive light microscopy techniques with limited availability. Here we show a simple optical design that combines these four techniques in a simple low-cost miniature epi-illuminator, which inserts into the differential interference-contrast (DIC) slider bay of a commercial microscope, without further additions required. We demonstrate with this device: 1) BSDF-based detection of Malarial parasites inside unstained human erythrocytes; 2) EF imaging with and without dichroic components, including detection of DAPI-stained Leishmania parasite without using excitation or emission filters; 3) RIC of black lipid membranes and other thin films, and 4) DFSR of patterned opaque and transparent surfaces. We believe that our design can expand the functionality of commercial bright field microscopes, provide easy field detection of parasites and be of interest to many users of light microscopy.

  3. Polarization resolved imaging with a reflection near-field optical microscope

    DEFF Research Database (Denmark)

    Bozhevolnyi, Sergey I.; Xiao, Mufei; Hvam, Jørn Märcher

    1999-01-01

    Using a rigorous microscopic point-dipole description of probe-sample interactions, we study imaging with a reflection scanning near-field optical microscope. Optical content, topographical artifacts, sensitivity window-i.e., the scale on which near-field optical images represent mainly optical c...

  4. Slim planar apparatus for converting LED light into collimated polarized light uniformly emitted from its top surface.

    Science.gov (United States)

    Teng, Tun-Chien; Tseng, Li-Wei

    2014-10-20

    This study proposes a slim planar apparatus for converting nonpolarized light from a light-emitting diode (LED) into an ultra-collimated linearly polarized beam uniformly emitted from its top surface. The apparatus was designed based on a folded-bilayer configuration comprising a light-mixing collimation element, polarization conversion element, and polarization-preserving light guide plate (PPLGP) with an overall thickness of 5 mm. Moreover, the apparatus can be extended transversally by connecting multiple light-mixing collimation elements and polarization conversion elements in a side-by-side configuration to share a considerably wider PPLGP, so the apparatus can have theoretically unlimited width. The simulation results indicate that the proposed apparatus is feasible for the maximal backlight modules in 39-inch liquid crystal panels. In the case of an apparatus with a 480 × 80 mm emission area and two 8-lumen LED light sources, the average head-on polarized luminance and spatial uniformity over the emission area was 5000 nit and 83%, respectively; the vertical and transverse angular distributions of the emitting light were only 5° and 10°, respectively. Moreover, the average degree of polarization and energy efficiency of the apparatus were 82% and 72%, respectively. As compared with the high-performance ultra-collimated nonpolarized backlight module proposed in our prior work, not only did the apparatus exhibit outstanding optical performance, but also the highly polarized light emissions actually increased the energy efficiency by 100%.

  5. Automatic identification of cell files in light microscopic images of conifer wood

    OpenAIRE

    Kennel, Pol; Subsol, Gérard; Guéroult, Michaël; Borianne, Philippe

    2010-01-01

    International audience; In this paper, we present an automatic method to recognize cell files in light microscopic images of conifer wood. This original method is decomposed into three steps: the segmentation step which extracts some anatomical structures in the image, the classification step which identifies in these structures the interesting cells, and the cell files recognition step. Some preliminary results obtained on several species of conifers are presented and analyzed.

  6. Inverted light-sheet microscope for imaging mouse pre-implantation development.

    Science.gov (United States)

    Strnad, Petr; Gunther, Stefan; Reichmann, Judith; Krzic, Uros; Balazs, Balint; de Medeiros, Gustavo; Norlin, Nils; Hiiragi, Takashi; Hufnagel, Lars; Ellenberg, Jan

    2016-02-01

    Despite its importance for understanding human infertility and congenital diseases, early mammalian development has remained inaccessible to in toto imaging. We developed an inverted light-sheet microscope that enabled us to image mouse embryos from zygote to blastocyst, computationally track all cells and reconstruct a complete lineage tree of mouse pre-implantation development. We used this unique data set to show that the first cell fate specification occurs at the 16-cell stage.

  7. The Light Microscopy Module: An On-Orbit Multi-User Microscope Facility

    Science.gov (United States)

    Motil, Susan M.; Snead, John H.

    2002-01-01

    The Light Microscopy Module (LMM) is planned as a remotely controllable on-orbit microscope subrack facility, allowing flexible scheduling and operation of fluids and biology experiments within the Fluids and Combustion Facility (FCF) Fluids Integrated Rack (FIR) on the International Space Station (ISS). The LMM will be the first integrated payload with the FIR to conduct four fluid physics experiments. A description of the LMM diagnostic capabilities, including video microscopy, interferometry, laser tweezers, confocal, and spectrophotometry, will be provided.

  8. Elementary and advanced Lie algebraic methods with applications to accelerator design, electron microscopes, and light optics

    International Nuclear Information System (INIS)

    Dragt, A.J.

    1987-01-01

    A review is given of elementary Lie algebraic methods for treating Hamiltonian systems. This review is followed by a brief exposition of advanced Lie algebraic methods including resonance bases and conjugacy theorems. Finally, applications are made to the design of third-order achromats for use in accelerators, to the design of subangstroem resolution electron microscopes, and to the classification and study of high order aberrations in light optics. (orig.)

  9. Material and device studies for the development of ultra-violet light emitting diodes (UV-LEDS) along polar, non-polar and semi-polar directions

    Science.gov (United States)

    Chandrasekaran, Ramya

    Over the past few years, significant effort was dedicated to the development of ultraviolet light emitting diodes (UV-LEDs) for a variety of applications. Such applications include chemical and biological detection, water purification and solid-state lighting. III-Nitride LEDs based on multiple quantum wells (MQWs) grown along the conventional [0001] (polar) direction suffer from the quantum confined Stark effect (QCSE), due to the existence of strong electric fields that arise from spontaneous and piezoelectric polarization. Thus, there is strong motivation to develop MQW-based III-nitride LED structures grown along non-polar and semi-polar directions. The goal of this dissertation is to develop UV-LEDs along the [0001] polar and [11 2¯ 0] non-polar directions by the method of Molecular Beam Epitaxy (MBE). The polar and non-polar LEDs were grown on the C-plane and R-plane sapphire substrates respectively. This work is a combination of materials science studies related to the nucleation, growth and n- and p-type doping of III-nitride films on these two substrates, as well as device studies related to fabrication and characterization of UV-LEDs. It was observed that the crystallographic orientation of the III-nitride films grown on R-plane sapphire depends strongly on the kinetic conditions of growth of the Aluminum Nitride (AIN) buffer. Specifically, growth of the AIN buffer under group III-rich conditions leads to nitride films having the (11 2¯ 0) non polar planes parallel to the sapphire surface, while growth of the buffer under nitrogen rich conditions leads to nitride films with the (11 2¯ 6) semi-polar planes parallel to the sapphire surface. The electron concentration and mobility for the films grown along the polar, non-polar and semi-polar directions were investigated. P-type doping of Gallium Nitride (GaN) films grown on the nonpolar (11 2¯ 0) plane do not suffer from polarity inversion and thus the material was doped p-type with a hole concentration

  10. Observation of sperm-head vacuoles and sperm morphology under light microscope.

    Science.gov (United States)

    Park, Yong-Seog; Park, Sol; Ko, Duck Sung; Park, Dong Wook; Seo, Ju Tae; Yang, Kwang Moon

    2014-09-01

    The presence of sperm-head vacuoles has been suspected to be deleterious to the outcomes of assisted reproductive technology (ART). It is difficult to accurately distinguish morphologically abnormal sperm with vacuoles under a light microscope. This study was performed to analyze the result of the observation of sperm-head vacuoles using Papanicolaou staining under a light microscope and whether the male partner's age affects these vacuoles. Sperm morphology with vacuoles was evaluated using Papanicolaou staining and observed under a light microscope (400×) in 980 men. The normal morphology was divided into three categories (group A, 14% of normal morphology). The criteria for the sperm-head vacuoles were those given in the World Health Organization manual. For the analysis of the age factor, the participants were divided into the following groups: 26-30 years, 31-35 years, 36-40 years, 41-45 years, and 46-50 years. The percentage of sperm-head vacuoles increased with normal sperm morphology (group A vs. groups B, C) (p<0.05). In the case of the age factor, a statistically significant difference was not observed across any of the age groups. A majority of the sperm-head vacuoles showed a statistically significant difference among normal morphology groups. Therefore, we should consider the probability of the percentage of sperm-head vacuoles not increasing with age but with abnormal sperm morphology. A further study is required to clarify the effect of the sperm-head vacuoles on ART outcomes.

  11. Dynamic light scattering microscope: accessing opaque samples with high spatial resolution.

    Science.gov (United States)

    Hiroi, Takashi; Shibayama, Mitsuhiro

    2013-08-26

    We developed a new technique that conducts dynamic light scattering (DLS) under a microscope with high spatial resolution. This technique dramatically extends the range of DLS application from transparent to opaque samples. The total scattered electric field contains both electric field generated from the samples and time-independent reflected electric field. These two components are decomposed by applying a partial heterodyne method. By using this technique, we successfully calculate the characteristic size distribution of both multiple-scattering samples and strong light-absorbing samples. This is the first study to observe the collective motion of particles in a highly concentrated solution by using DLS.

  12. Visible Light Emission from Atomic Scale Patterns Fabricated by the Scanning Tunneling Microscope

    DEFF Research Database (Denmark)

    Thirstrup, C.; Sakurai, M.; Stokbro, Kurt

    1999-01-01

    Scanning tunneling microscope (STM) induced light emission from artificial atomic scale structures comprising silicon dangling bonds on hydrogen-terminated Si(001) surfaces has been mapped spatially and analyzed spectroscopically in the visible spectral range. The light emission is based on a novel...... mechanism involving optical transitions between a tip state and localized states on the sample surface. The wavelength of the photons can be changed by the bias voltage of the STM. The spatial resolution of the photon maps is as good as that of STM topographic images and the photons are emitted from...

  13. Myth polar light. Why sky bands, herring lightnings, and solar winds fascinate

    International Nuclear Information System (INIS)

    Hunnekuhl, Michael

    2014-01-01

    The actual state of knowledge of the polar-light research is in this illustrated volume as entertainingly as scientific-foundedly presented. The pecularities of pola lights beyond the polar-light zones as for instance in Germany are thematized and the conditions and periods, in which it there occurs, explained. Michael Hunnekuhl succeeds to mediate the fascination and emotion and simultaneously to explain the phenomena according to the latest state of science generally understandably. Which very old interpretations and descriptions are transmitted, which imaginations had men of polar lights long before the science could them explain? Hunnekuhl takes the reader along with into the world of legends and myths around the polar light. An experience report from the deeply snowed up wideness of Lapland lets everybody closely participate at a polar-light observation and feel the emotion, which it can fan. Above 70 polar-light pictures of high value and further explaining graphics show the continuously changing play of colors, supplement the explanations, and make the fascination comprehensible. Spectacular polar-light films from the international space station ISS, photographs from sun-observation satellites, as well as a polar-light film in real time are bound in the book via QR codes and make the time dimension and the dynamics of this fascinating natural spectacle alively comprehensible.

  14. Highly polarized light emission by isotropic quantum dots integrated with magnetically aligned segmented nanowires

    International Nuclear Information System (INIS)

    Uran, Can; Erdem, Talha; Guzelturk, Burak; Perkgöz, Nihan Kosku; Jun, Shinae; Jang, Eunjoo; Demir, Hilmi Volkan

    2014-01-01

    In this work, we demonstrate a proof-of-concept system for generating highly polarized light from colloidal quantum dots (QDs) coupled with magnetically aligned segmented Au/Ni/Au nanowires (NWs). Optical characterizations reveal that the optimized QD-NW coupled structures emit highly polarized light with an s-to p-polarization (s/p) contrast as high as 15:1 corresponding to a degree of polarization of 0.88. These experimental results are supported by the finite-difference time-domain simulations, which demonstrate the interplay between the inter-NW distance and the degree of polarization.

  15. Performance of light-emitting diode fluorescence microscope for diagnosis of tuberculosis.

    Science.gov (United States)

    Bhalla, Manpreet; Sidiq, Zeeshan; Sharma, P P; Singhal, Ritu; Myneedu, V P; Sarin, Rohit

    2013-09-01

    Fluorescence microscopy (FM) over the years has shown the potential for increasing the performance of microscopy. The present study was aimed to access the performance of the LED microscope for the detection of acid fast bacilli in a tuberculosis (TB) endemic country. The study was conducted at a National Reference Laboratory (NRL) in New Delhi, India. Sputum samples were collected from suspected TB patients. Each sample was processed with Auramine O and ZN methods. Auramine O stained smears were evaluated using two different excitatory light sources (MVP and LED); and ZN stained smears were examined under light microscope. The mean time required to read the smears with different modalities was recorded. Bacterial cultures provided the reference standard. A total of 200 patients were included in this study. Sensitivity and specificity for the LED assessment, MVP assessment and light microscopy were 83.1% and 82.4%, 78.5% and 87.5% and 81.6% and 83.5%, respectively. Mean reading time was approximately three times faster than ZN microscopy. The mean time to read a negative smear was 2min with fluorescence microscopy and 5min with light microscopy with time savings of 60%. Although the use of LED-FM only marginally increased sensitivity, the considerable time saving ability combined with very good acceptance and ease of use makes it a reliable alternative to other conventional methods available. Copyright © 2013 Asian-African Society for Mycobacteriology. Published by Elsevier Ltd. All rights reserved.

  16. Development of a Hybrid Atomic Force Microscopic Measurement System Combined with White Light Scanning Interferometry

    Directory of Open Access Journals (Sweden)

    Xiaotang Hu

    2011-12-01

    Full Text Available A hybrid atomic force microscopic (AFM measurement system combined with white light scanning interferometry for micro/nanometer dimensional measurement is developed. The system is based on a high precision large-range positioning platform with nanometer accuracy on which a white light scanning interferometric module and an AFM head are built. A compact AFM head is developed using a self-sensing tuning fork probe. The head need no external optical sensors to detect the deflection of the cantilever, which saves room on the head, and it can be directly fixed under an optical microscopic interferometric system. To enhance the system’s dynamic response, the frequency modulation (FM mode is adopted for the AFM head. The measuring data can be traceable through three laser interferometers in the system. The lateral scanning range can reach 25 mm × 25 mm by using a large-range positioning platform. A hybrid method combining AFM and white light scanning interferometry is proposed to improve the AFM measurement efficiency. In this method, the sample is measured firstly by white light scanning interferometry to get an overall coarse morphology, and then, further measured with higher resolution by AFM. Several measuring experiments on standard samples demonstrate the system’s good measurement performance and feasibility of the hybrid measurement method.

  17. Electrically controlled phases of partially polarized light and orientational Kerr effect in liquid crystal ferroelectrics

    Science.gov (United States)

    Kiselev, Alexei D.; Kesaev, Vladimir V.; Pozhidaev, Evgeny P.

    2017-10-01

    We study the electro-optic properties of subwavelength-pitch deformed-helix ferroelectric liquid crystals illuminated with partially polarized light. In an experimental setup based on the Mach-Zehnder interferometer, it is found that the interference pattern crucially depends on the degree of polarization of the incident light. We evaluate the electric field dependence of both the Pancharatnam relative phase and the geometric phase for the general case of nonunitarily evolving mixed polarization states.

  18. Effect of light source parameters on the polarization properties of the beam

    Science.gov (United States)

    Liu, Dan; Liu, Yan; Jiang, Hui-lin; Liu, Zhi; Zhou, Xin; Fang, Hanhan

    2013-08-01

    Polarized laser has been widely used in free space optical communication, laser radar, and laser ranging system because of its advantages of good performance in recent years. The changes of laser polarization properties in the process of transmission in atmospheric turbulence have a certain impact on the system performance. The paper research on the rule of polarization properties changes of Gauss Schell model beam in turbulent conditions. And analysis the main factors to affect the polarization properties by numerical simulation using MATLAB software tools. The factors mainly including: initial polarization, coherence coefficient, spot size and the intensity of the atmospheric turbulent. The simulation results show that, the degree of polarization will converge to the initial polarization when the beam propagation in turbulent conditions. The degrees of polarization change to different value when initial polarization of beam is different in a short distance. And, the degrees of polarization converge to the initial polarization after long distance. Beam coherence coefficient bigger, the degree of polarization and change range increases bigger. The change of polarization more slowly for spot size is bigger. The change of polarization change is faster for longer wavelength. The conclusion of the study indicated that the light source parameters effect the changes of polarization properties under turbulent conditions. The research provides theory basis for the polarization properties of the laser propagation, and it will plays a significant role in optical communication and target recognition.

  19. Operating microscope light-induced phototoxic maculopathy after transscleral sutured posterior chamber intraocular lens implantation.

    Science.gov (United States)

    Kweon, Eui Yong; Ahn, Min; Lee, Dong Wook; You, In Cheon; Kim, Min Jung; Cho, Nam Chun

    2009-01-01

    The purpose of this study is to report the features of operating microscope light-induced retinal phototoxic maculopathy after transscleral sutured posterior chamber intraocular lens (TSS PC-IOL) implantation. The charts of 118 patients who underwent TSS PC-IOL implantation surgery at Chonbuk National University Hospital (Jeonju, Korea) between March 1999 and February 2008 were retrospectively reviewed. Fourteen patients underwent combined 3-port pars plana vitrectomy and TSS PC-IOL implantation (vitrectomy group), and 104 patients underwent TSS PC-IOL implantation only (nonvitrectomy group). All surgeries were performed under the same coaxial illuminated microscope. All diagnoses were confirmed through careful fundus examination and fluorescein angiography (FA). Diagnoses of retinal phototoxic maculopathy were established in 10 (8.47%) of 118 TSS PC-IOL implantation cases. Phototoxic maculopathy occurred more frequently in the vitrectomy group than in the nonvitrectomy group (6/14 versus 4/104, respectively; P microscope light-induced retinal phototoxic maculopathy can occur more frequently after TSS PC-IOL implantation than after casual cataract surgery, especially when TSS PC-IOL is combined with vitrectomy surgery. Surgeons should take precautions to prevent retinal phototoxicity after TSS PC-IOL implantation and vitrectomy.

  20. The HVAC Challenges of Upgrading an Old Lab for High-end Light Microscopes

    Science.gov (United States)

    Richard, R.; Martone, P.; Callahan, L.M.

    2014-01-01

    The University of Rochester Medical Center forms the centerpiece of the University of Rochester's health research, teaching, patient care, and community outreach missions. Within this large facility of over 5 million square feet, demolition and remodeling of existing spaces is a constant activity. With more than $145 million in federal research funding, lab space is frequently repurposed and renovated to support this work. The URMC Medical Center Facilities Organization supporting small to medium space renovations is constantly challenged and constrained by the existing mechanical infrastructure and budgets to deliver a renovated space that functions within the equipment environmental parameters. One recent project, sponsored by the URMC Shared Resources Laboratory, demonstrates these points. The URMC Light Microscopy Shared Resource Laboratory requested renovation of a 121 sq. ft. room in a 40 year old building which would enable placement of a laser capture microdissection microscope and a Pascal 5 laser scanning confocal microscope with the instruments separated by a blackout curtain. This poster discusses the engineering approach implemented to bring an older lab into the environmental specifications needed for the proper operation of the high-end light microscopes.

  1. A combined light sheet fluorescence and differential interference contrast microscope for live imaging of multicellular specimens.

    Science.gov (United States)

    Baker, R P; Taormina, M J; Jemielita, M; Parthasarathy, R

    2015-05-01

    We describe a microscope capable of both light sheet fluorescence microscopy and differential interference contrast microscopy (DICM). The two imaging modes, which to the best of our knowledge have not previously been combined, are complementary: light sheet fluorescence microscopy provides three-dimensional imaging of fluorescently labelled components of multicellular systems with high speed, large fields of view, and low phototoxicity, whereas differential interference contrast microscopy reveals the unlabelled neighbourhood of tissues, organs, and other structures with high contrast and inherent optical sectioning. Use of a single Nomarski prism for differential interference contrast microscopy and a shared detection path for both imaging modes enables simple integration of the two techniques in one custom microscope. We provide several examples of the utility of the resulting instrument, focusing especially on the digestive tract of the larval zebrafish, revealing in this complex and heterogeneous environment anatomical features, the behaviour of commensal microbes, immune cell motions, and more. © 2015 The Authors Journal of Microscopy © 2015 Royal Microscopical Society.

  2. Electrical tuning of the polarization state of light using graphene-integrated anisotropic metasurfaces

    Science.gov (United States)

    Dutta-Gupta, Shourya; Dabidian, Nima; Kholmanov, Iskandar; Belkin, Mikhail A.; Shvets, Gennady

    2017-03-01

    Plasmonic metasurfaces have been employed for moulding the flow of transmitted and reflected light, thereby enabling numerous applications that benefit from their ultra-thin sub-wavelength format. Their appeal is further enhanced by the incorporation of active electro-optic elements, paving the way for dynamic control of light's properties. In this paper, we realize a dynamic polarization state generator using a graphene-integrated anisotropic metasurface (GIAM) that converts the linear polarization of the incident light into an elliptical one. This is accomplished by using an anisotropic metasurface with two principal polarization axes, one of which possesses a Fano-type resonance. A gate-controlled single-layer graphene integrated with the metasurface was employed as an electro-optic element controlling the phase and intensity of light polarized along the resonant axis of the GIAM. When the incident light is polarized at an angle to the resonant axis of the metasurface, the ellipticity of the reflected light can be dynamically controlled by the application of a gate voltage. Thus accomplished dynamic polarization control is experimentally demonstrated and characterized by measuring the Stokes polarization parameters. Large changes of the ellipticity and the tilt angle of the polarization ellipse are observed. Our measurements show that the tilt angle can be changed from positive values through zero to negative values while keeping the ellipticity constant, potentially paving the way to rapid ellipsometry and other characterization techniques requiring fast polarization shifting. This article is part of the themed issue 'New horizons for nanophotonics'.

  3. A compact light-sheet microscope for the study of the mammalian central nervous system.

    Science.gov (United States)

    Yang, Zhengyi; Haslehurst, Peter; Scott, Suzanne; Emptage, Nigel; Dholakia, Kishan

    2016-05-24

    Investigation of the transient processes integral to neuronal function demands rapid and high-resolution imaging techniques over a large field of view, which cannot be achieved with conventional scanning microscopes. Here we describe a compact light sheet fluorescence microscope, featuring a 45° inverted geometry and an integrated photolysis laser, that is optimized for applications in neuroscience, in particular fast imaging of sub-neuronal structures in mammalian brain slices. We demonstrate the utility of this design for three-dimensional morphological reconstruction, activation of a single synapse with localized photolysis, and fast imaging of neuronal Ca(2+) signalling across a large field of view. The developed system opens up a host of novel applications for the neuroscience community.

  4. Light and electron microscopic localization of GABAA-receptors on cultured cerebellar granule cells and astrocytes using immunohistochemical techniques

    DEFF Research Database (Denmark)

    Hansen, Gert Helge; Hösli, E; Belhage, B

    1991-01-01

    . At the light microscope level specific staining of GABAA-receptors was localized in various types of neurones in explant cultures of rat cerebellum using the indirect peroxidase-antiperoxidase (PAP) technique, whereas no specific staining was found in astrocytes. At the electron microscope level labeling...

  5. Quantitative analysis with advanced compensated polarized light microscopy on wavelength dependence of linear birefringence of single crystals causing arthritis

    Science.gov (United States)

    Takanabe, Akifumi; Tanaka, Masahito; Taniguchi, Atsuo; Yamanaka, Hisashi; Asahi, Toru

    2014-07-01

    To improve our ability to identify single crystals causing arthritis, we have developed a practical measurement system of polarized light microscopy called advanced compensated polarized light microscopy (A-CPLM). The A-CPLM system is constructed by employing a conventional phase retardation plate, an optical fibre and a charge-coupled device spectrometer in a polarized light microscope. We applied the A-CPLM system to measure linear birefringence (LB) in the visible region, which is an optical anisotropic property, for tiny single crystals causing arthritis, i.e. monosodium urate monohydrate (MSUM) and calcium pyrophosphate dihydrate (CPPD). The A-CPLM system performance was evaluated by comparing the obtained experimental data using the A-CPLM system with (i) literature data for a standard sample, MgF2, and (ii) experimental data obtained using an established optical method, high-accuracy universal polarimeter, for the MSUM. The A-CPLM system was found to be applicable for measuring the LB spectra of the single crystals of MSUM and CPPD, which cause arthritis, in the visible regions. We quantitatively reveal the large difference in LB between MSUM and CPPD crystals. These results demonstrate the usefulness of the A-CPLM system for distinguishing the crystals causing arthritis.

  6. Progress in tear microdesiccate analysis by combining various transmitted-light microscope techniques.

    Science.gov (United States)

    Traipe-Salas, Felipe; Traipe-Castro, Leonidas; Salinas-Toro, Daniela; López, Daniela; Valenzuela, Felipe; Cartes, Christian; Toledo-Araya, Héctor; Pérez, Claudio; López Solís, Remigio

    2016-06-03

    Tear desiccation on a glass surface followed by transmitted-light microscopy has served as diagnostic test for dry eye. Four distinctive morphological domains (zones I, II, III and transition band) have been recently recognized in tear microdesiccates. Physicochemical dissimilarities among those domains hamper comprehensive microscopic examination of tear microdesiccates. Optimal observation conditions of entire tear microdesiccates are now investigated. One-μl aliquots of tear collected from individual healthy eyes were dried at ambient conditions on microscope slides. Tear microdesiccates were examined by combining low-magnification objective lenses with transmitted-light microscopy (brightfield, phase contrasts Ph1,2,3 and darkfield). Fern-like structures (zones II and III) were visible with all illumination methods excepting brightfield. Zone I was the microdesiccate domain displaying the most noticeable illumination-dependent variations, namely transparent band delimited by an outer rim (Ph1, Ph2), homogeneous compactly built structure (brightfield) or invisible domain (darkfield, Ph3). Intermediate positions of the condenser (BF/Ph1, Ph1/Ph2) showed a structured roughly cylindrical zone I. The transition band also varied from invisibility (brightfield) to a well-defined domain comprising interwoven filamentous elements (phase contrasts, darkfield). Imaging of entire tear microdesiccates by transmitted-light microscopy depends upon illumination. A more comprehensive description of tear microdesiccates can be achieved by combining illumination methods.

  7. The first isolation of Cochliopodium gulosum Schaeffer, 1926 (Lobosea, Himatismenida) since its initial description. I. light-microscopical investigation

    OpenAIRE

    Kudryavtsev, Alexander

    1999-01-01

    A marine lobose amoeba possessing characteristic features of the genus Cochliopodium (Hertwig and Lesser, 1874) Kudryavtsev, 1999 was found in the upper layer of sand at the beach of Keret Island, Kandalaksha Bay, the White Sea. Light-microscopical identity of this isolate and Cochliopodium gulosum Schaeffer, 1926 has been shown. This species has never been isolated and studied since its initial description. Its validity and generic position are confirmed by the results of light-microscopical...

  8. Development of a scanning tunneling microscope combined with a synchrotron radiation light source

    International Nuclear Information System (INIS)

    Hasegawa, Yukio; Okuda, Taichi; Eguchi, Toyoaki; Matsushima, Takeshi; Harasawa, Ayumi; Akiyama, Kotone; Kinoshita, Toyohiko

    2005-01-01

    We have developed a scanning tunneling microscope (STM) combined with a synchrotron-radiation light source (SR-STM) aiming at elemental analysis in a spatial resolution of STM. Using SR-STM atomically resolved STM images under the irradiation and also X-ray adsorption spectra clearly showing an adsorption edge of a substrate were successfully obtained by detecting photo-emitted electrons with the STM tip. In order to focus the probing area of the photo-induced current, a glass-coated metal tip sharpened with focused ion beam was used as a probe. The present situation and prospects of the instrument are discussed in this review. (author)

  9. Optical sectioning microscopes with no moving parts using a micro-stripe array light emitting diode.

    Science.gov (United States)

    Poher, V; Zhang, H X; Kennedy, G T; Griffin, C; Oddos, S; Gu, E; Elson, D S; Girkin, M; French, P M W; Dawson, M D; Neil, M A

    2007-09-03

    We describe an optical sectioning microscopy system with no moving parts based on a micro-structured stripe-array light emitting diode (LED). By projecting arbitrary line or grid patterns onto the object, we are able to implement a variety of optical sectioning microscopy techniques such as grid-projection structured illumination and line scanning confocal microscopy, switching from one imaging technique to another without modifying the microscope setup. The micro-structured LED and driver are detailed and depth discrimination capabilities are measured and calculated.

  10. An optical investigation of dentinal discoloration due to commonly endodontic sealers, using the transmitted light polarizing microscopy and spectrophotometry.

    Science.gov (United States)

    Suciu, Ioana; Ionescu, Ecaterina; Dimitriu, Bogdan Alexandru; Bartok, Ruxandra Ioana; Moldoveanu, Georgiana Florentina; Gheorghiu, Irina Maria; Suciu, Ileana; Ciocîrdel, Mihai

    2016-01-01

    The aim of this study was to establish the degree of tooth crown staining by commonly used endodontic sealers. Crown discolorations by tooth canal sealers [AH Plus (Dentsply DeTrey Gmbh, Konstanz, Germany); Endofill (Produits Dentaires SA, Vevey, Switzerland); Apexit (Dentsply DeTrey Gmbh, Konstanz, Germany); and MTA Fillapex (Angelus, Londrina, Brazil)] were tested on extracted human premolars. The samples were divided into five groups of five samples each, after root canal sealing. Five teeth were used as control groups. The spectrophotometric method was performed in order to quantify in terms of color change of the coronal part (it was also recorded a track on how the color changes over time). For the microscopic study of the extracted dental specimens subjected to this study, polarized transmitted light microscopy was used. This method involves the development of special microscopic preparations, called "thin sections". In our case, the thin section was performed on 20 prepared and obturated recently extracted teeth. The degree of discoloration was determined after one week and three months using spectrophotometry and polarized light microscopy. All sealers usually cause some degree of discoloration on the cervical aspect of the crowns that increases in time. AH Plus and Endofill caused the greatest discoloration, followed by Apexit and MTA Fillapex.

  11. Manipulating light polarizations with a hyperbolic metamaterial waveguide.

    Science.gov (United States)

    Zhu, Hua; Yin, Xiang; Chen, Lin; Zhu, Zhongshu; Li, Xun

    2015-10-15

    In this Letter we demonstrate that a hyperbolic metamaterial (HMM) waveguide array exhibits a giant modal birefringence between the TE and TM modes by utilization of a rectangular waveguide cross section. We further reveal that the designed polarization manipulation device using such a HMM waveguide array with a subwavelength thickness presents the ability to function as a polarizer or quarter- or half-wave plate that enables transmission only for electromagnetic wave (EW) that is polarized at a specific direction, or converting linearly polarized EW to circularly and elliptically polarized EW or rotating linearly polarized EW with 90° at terahertz (THz) frequencies. A giant modal birefringence between the TE and TM modes from 0.8 to 2 between 2 and 4.8 THz is achievable, which is dozens of times higher than conventional quartz birefringent crystals for THz waves. This polarization manipulation device has the performance merits including high transmission efficiency, ultra-compactness, and tunable birefringence, offering a promising approach to manipulating the polarization states of EW.

  12. Light polarization management via reflection from arrays of sub-wavelength metallic twisted bands

    Science.gov (United States)

    Nawrot, M.; Haberko, J.; Zinkiewicz, Ł.; Wasylczyk, P.

    2017-12-01

    With constant progress of nano- and microfabrication technologies, photolithography in particular, a number of sub-wavelength metallic structures have been demonstrated that can be used to manipulate light polarization. Numerical simulations of light propagation hint that helical twisted bands can have interesting polarization properties. We use three-dimensional two-photon photolithography (direct laser writing) to fabricate a few-micrometer-thick arrays of twisted bands and coat them uniformly with metal. We demonstrate that circular polarization can be generated from linear polarization upon reflection from such structures over a broad range of frequencies in the mid infrared.

  13. Sperm head vacuoles--light microscopic and ultrastructural observations: a case report.

    Science.gov (United States)

    Zhang, Shucheng; Wang, Ning; He, Bin; Cheng, Jie; Xi, Shui; Wang, Shang-ming; Gao, Yu; Wang, Jiedong

    2012-05-01

    Sperm head vacuoles are easily detectable in human spermatozoa under the electron microscope. A sperm head vacuole is considered abnormal when it exceeds 20% of the head's cross-sectional area. The authors report a rare case of primary spermatozoa deformity with 100% vacuolated head and evaluate the correlation between presence of head vacuoles/nucleus vacuoles and abnormal transformation of nucleoprotamine types, defects of nucleoprotamine, and gene disorders of chromatin/chromosome/spermatogenesis. A 43-year-old male patient with infertility came to the Reproduction Health Center, Hebei, China. Semen was examined in accordance with the WHO criteria, and the spermatozoa were counted. Two hundred spermatozoa were observed both under light microscope and the electronic microscope. About 50% of the spermatozoa had head deformities. In the intact spermatozoa, the heads were 100% vacuolated. Under ultrastructural observation, abnormalities were observed and two major types of spermatozoa were detected. In the head of those incompletely mature spermatozoa, four kinds of the nucleus vacuoles were observed. Abnormal spermatozoa with head vacuoles account for the patient infertility.

  14. Analytical electron microscope based on scanning transmission electron microscope with wavelength dispersive x-ray spectroscopy to realize highly sensitive elemental imaging especially for light elements

    International Nuclear Information System (INIS)

    Koguchi, Masanari; Tsuneta, Ruriko; Anan, Yoshihiro; Nakamae, Koji

    2017-01-01

    An analytical electron microscope based on the scanning transmission electron microscope with wavelength dispersive x-ray spectroscopy (STEM-WDX) to realize highly sensitive elemental imaging especially for light elements has been developed. In this study, a large-solid-angle multi-capillary x-rays lens with a focal length of 5 mm, long-time data acquisition (e.g. longer than 26 h), and a drift-free system made it possible to visualize boron-dopant images in a Si substrate at a detection limit of 0.2 atomic percent. (paper)

  15. Development of scanning X-ray microscopes for materials science spectromicroscopy at the Advanced Light Source

    International Nuclear Information System (INIS)

    Warwick, T.; Ade, H.

    1997-07-01

    Third generation synchrotron sources of soft x-rays provide an excellent opportunity to apply established x-ray spectroscopic materials analysis techniques to surface imaging on a sub-micron scale. This paper describes an effort underway at the Advanced Light Source (ALS) to pursue this development using Fresnel zone plate lenses. These are used to produce a sub-micron spot of x-rays for use in scanning microscopy. Several groups have developed microscopes using this technique. A specimen is rastered in the focused x-ray spot and a detector signal is acquired as a function of position to generate an image. Spectroscopic capability is added by holding the small spot on a feature of interest and scanning through the spectrum. The authors are pursuing two spectroscopic techniques: Near Edge X-ray Absorption Spectroscopy (NEXAFS), X-ray Photoelectron Spectroscopy (XPS) which together provide a powerful capability for light element analysis in materials science

  16. Light in condensed matter in the upper atmosphere as the origin of homochirality: circularly polarized light from Rydberg matter.

    Science.gov (United States)

    Holmlid, Leif

    2009-01-01

    Clouds of the condensed excited Rydberg matter (RM) exist in the atmospheres of comets and planetary bodies (most easily observed at Mercury and the Moon), where they surround the entire bodies. Vast such clouds are recently proposed to exist in the upper atmosphere of Earth (giving rise to the enormous features called noctilucent clouds, polar mesospheric clouds, and polar mesospheric summer radar echoes). It has been shown in experiments with RM that linearly polarized visible light scattered from an RM layer is transformed to circularly polarized light with a probability of approximately 50%. The circular Rydberg electrons in the magnetic field in the RM may be chiral scatterers. The magnetic and anisotropic RM medium acts as a circular polarizer probably by delaying one of the perpendicular components of the light wave. The delay process involved is called Rabi-flopping and gives delays of the order of femtoseconds. This strong effect thus gives intense circularly polarized visible and UV light within RM clouds. Amino acids and other chiral molecules will experience a strong interaction with this light field in the upper atmospheres of planets. The interaction will vary with the stereogenic conformation of the molecules and in all probability promote the survival of one enantiomer. Here, this strong effect is proposed to be the origin of homochirality. The formation of amino acids in the RM clouds is probably facilitated by the catalytic effect of RM.

  17. Effects of differently polarized microwave radiation on the microscopic structure of the nuclei in human fibroblasts.

    Science.gov (United States)

    Shckorbatov, Yuriy G; Pasiuga, Vladimir N; Goncharuk, Elena I; Petrenko, Tatiana Ph; Grabina, Valentin A; Kolchigin, Nicolay N; Ivanchenko, Dmitry D; Bykov, Victor N; Dumin, Oleksandr M

    2010-10-01

    To investigate the influence of microwave radiation on the human fibroblast nuclei, the effects of three variants of electromagnetic wave polarization, linear and left-handed and right-handed elliptically polarized, were examined. Experimental conditions were: frequency (f) 36.65 GHz, power density (P) at the surface of exposed object 1, 10, 30, and 100 µW/cm(2), exposure time 10 s. Human fibroblasts growing in a monolayer on a cover slide were exposed to microwave electromagnetic radiation. The layer of medium that covered cells during microwave exposure was about 1 mm thick. Cells were stained immediately after irradiation by 2% (w/v) orcein solution in 45% (w/v) acetic acid. Experiments were made at room temperature (25 °C), and control cell samples were processed in the same conditions. We assessed heterochromatin granule quantity (HGQ) at 600× magnification. Microwave irradiation at the intensity of 1 µW/cm(2) produced no effect, and irradiation at the intensities of 10 and 100 µW/cm(2) induced an increase in HGQ. More intense irradiation induced more chromatin condensation. The right-handed elliptically polarized radiation revealed more biological activity than the left-handed polarized one.

  18. Ultraviolet Laser SQUID Microscope for GaN Blue Light Emitting Diode Testing

    International Nuclear Information System (INIS)

    Daibo, M; Kamiwano, D; Kurosawa, T; Yoshizawa, M; Tayama, N

    2006-01-01

    We carried out non-contacting measurements of photocurrent distributions in GaN blue light emitting diode (LED) chips using our newly developed ultraviolet (UV) laser SQUID microscope. The UV light generates the photocurrent, and then the photocurrent induces small magnetic fields around the chip. An off-axis arranged HTS-SQUID magnetometer is employed to detect a vector magnetic field whose typical amplitude is several hundred femto-tesla. Generally, it is difficult to obtain Ohmic contacts for p-type GaN because of the low hole concentration in the p-type epitaxial layer and the lack of any available metal with a higher work function compared with the p-type GaN. Therefore, a traditional probecontacted electrical test is difficult to conduct for wide band gap semiconductors without an adequately annealed electrode. Using the UV-laser SQUID microscope, the photocurrent can be measured without any electrical contact. We show the photocurrent vector map which was reconstructed from measured magnetic fields data. We also demonstrate how we found the position of a defect of the electrical short circuits in the LED chip

  19. Light-microscope specimen holder with 3-axis rotation and small-angle control.

    Science.gov (United States)

    Iwabuchi, Sadahiro; Koh, Jin-Young; Wardenburg, Michael; Johnson, James D; Harata, N Charles

    2014-01-15

    Although recent developments in methodologies for light microscopy have enabled imaging of fine biological structures, such imaging is often accompanied by two types of problems. One is a tilting of the specimen with respect to the x-y plane (i.e. rotation around the x- or y-axis) such that the sample is not perpendicular to the optical z-axis, and the other is rotation around the z-axis that precludes optimal orientations for imaging and experimentation. These rotation problems can cause optical aberrations and hamper imaging experiments, even when the angular difference from the ideal position is small. In order to correct for these practical issues, we have developed a specimen holder with 3-axis (x-y-z) rotation for an inverted light microscope. This allows for full-range rotations of 2-4° for x-, y-axes, ~24° for z-axis, and a small-angle control of microscope stage without requiring changes to the existing optical components. Similar devices with full capability have not been available. It will be useful for imaging experiments with biomedical applications. Copyright © 2013 Elsevier B.V. All rights reserved.

  20. Light microscopic image analysis system to quantify immunoreactive terminal area apposed to nerve cells

    Science.gov (United States)

    Wu, L. C.; D'Amelio, F.; Fox, R. A.; Polyakov, I.; Daunton, N. G.

    1997-01-01

    The present report describes a desktop computer-based method for the quantitative assessment of the area occupied by immunoreactive terminals in close apposition to nerve cells in relation to the perimeter of the cell soma. This method is based on Fast Fourier Transform (FFT) routines incorporated in NIH-Image public domain software. Pyramidal cells of layer V of the somatosensory cortex outlined by GABA immunolabeled terminals were chosen for our analysis. A Leitz Diaplan light microscope was employed for the visualization of the sections. A Sierra Scientific Model 4030 CCD camera was used to capture the images into a Macintosh Centris 650 computer. After preprocessing, filtering was performed on the power spectrum in the frequency domain produced by the FFT operation. An inverse FFT with filter procedure was employed to restore the images to the spatial domain. Pasting of the original image to the transformed one using a Boolean logic operation called 'AND'ing produced an image with the terminals enhanced. This procedure allowed the creation of a binary image using a well-defined threshold of 128. Thus, the terminal area appears in black against a white background. This methodology provides an objective means of measurement of area by counting the total number of pixels occupied by immunoreactive terminals in light microscopic sections in which the difficulties of labeling intensity, size, shape and numerical density of terminals are avoided.

  1. Three-dimensional measuring technique for surface topography using a light-sectioning microscope.

    Science.gov (United States)

    Xia, Linglin; Chen, Peifeng; Wang, Ying; Zhou, Le; Luo, Xi

    2012-03-10

    Three-dimensional (3D) surface topographic analysis, measurement, and assessment techniques have raised great interest not only among researchers but also among industrial users. Many industrial processes and applications are directly influenced by the small-scale roughness of surface finishes. This paper describes the development and implementation of a noncontact, three-dimensional, microtopography measuring system. The instrument is formed by combining a modified light-sectioning microscope subsystem with a computer subsystem. In particular, optical system characteristics of the light-sectioning microscope are investigated, and a textured steel sheet is measured to demonstrate good practical outcomes. Details of measuring processes and image processing algorithms are provided, such as procedures for measurement, image edge extraction, and 3D topography reconstruction. After the 3D topography of the measured surface has been reconstructed, the topography field description parameters are calculated. A standard roughness block was used for calibration of the surface microtopography measuring system. Results obtained showed the measurement method output has good agreement with the actual asperity (unevenness or roughness) of the surface. The computer subsystem is used to process and control asperity measurements and image generation, and for image acquisition and presentation.

  2. Further light microscopic studies on morphology and development of Pneumocystis carinii.

    Science.gov (United States)

    Yoshida, Y; Shiota, T; Yamada, M; Matsumoto, Y

    1981-01-01

    In order to add more advance in light microscopic investigation of P. carinii, phase contrast microscopy partly followed by wet giemsa stain and semiultrathin section of the lungs embedded in JB-4 plastic were studied. In phase contrast microscopy, small and large sized trophozoites of P. carinii were clearly recognized. Although movement of trophozoite was not found, rhythmic movement of intracystic bodies with filopodia was often seen in mature cyst. Those living organisms were then directly stained with Giemsa by infiltrating under the coverglass. Thus the organism could be investigated both in unstained and stained conditions. It is noticed with interest that 8 intracystic bodies seem to fill up the cavity of cyst when cell division is completed, then they liberate and become independent into spherical bodies, followed by banana-shaped or amoeboid forms with motility. An emphasis was done that semiultrathin section made from JB-4 plastic embedded lungs was quite useful for investigation of P. carinii infection. Several sizes of mononuclear thin-walked trophozoites, mature and immature cysts, and empty cysts were more clearly distinguished than any other light microscopical method ever reported.

  3. Optical asymmetric cryptography based on amplitude reconstruction of elliptically polarized light

    Science.gov (United States)

    Cai, Jianjun; Shen, Xueju; Lei, Ming

    2017-11-01

    We propose a novel optical asymmetric image encryption method based on amplitude reconstruction of elliptically polarized light, which is free from silhouette problem. The original image is analytically separated into two phase-only masks firstly, and then the two masks are encoded into amplitudes of the orthogonal polarization components of an elliptically polarized light. Finally, the elliptically polarized light propagates through a linear polarizer, and the output intensity distribution is recorded by a CCD camera to obtain the ciphertext. The whole encryption procedure could be implemented by using commonly used optical elements, and it combines diffusion process and confusion process. As a result, the proposed method achieves high robustness against iterative-algorithm-based attacks. Simulation results are presented to prove the validity of the proposed cryptography.

  4. Theoretical model of a polarization diffractive elements for the light beams conversion holographic formation in PDLCs

    Science.gov (United States)

    Sharangovich, Sergey N.; Semkin, Artem O.

    2017-12-01

    In this work a theoretical model of the holographic formation of the polarization diffractive optical elements for the transformation of Gaussian light beams into Bessel-like ones in polymer-dispersed liquid crystals (PDLC) is developed. The model is based on solving the equations of photo-induced Fredericks transition processes for polarization diffractive elements formation by orthogonally polarized light beams with inhomogeneous amplitude and phase profiles. The results of numerical simulation of the material's dielectric tensor changing due to the structure's formation process are presented for various recording beams' polarization states. Based on the results of numerical simulation, the ability to form the diffractive optical elements for light beams transformation by the polarization holography methods is shown.

  5. Modular low-light microscope for imaging cellular bioluminescence and radioluminescence.

    Science.gov (United States)

    Kim, Tae Jin; Türkcan, Silvan; Pratx, Guillem

    2017-05-01

    Low-light microscopy methods are receiving increased attention as new applications have emerged. One such application is to allow longitudinal imaging of light-sensitive cells with no phototoxicity and no photobleaching of fluorescent biomarkers. Another application is for imaging signals that are inherently dim and undetectable using standard microscopy techniques, such as bioluminescence, chemiluminescence or radioluminescence. In this protocol, we provide instructions on how to build a modular low-light microscope (1-4 d) by coupling two microscope objective lenses, back to back from each other, using standard optomechanical components. We also provide directions on how to image dim signals such as those of radioluminescence (1-1.5 h), bioluminescence (∼30 min) and low-excitation fluorescence (∼15 min). In particular, radioluminescence microscopy is explained in detail, as it is a newly developed technique that enables the study of small-molecule transport (e.g., radiolabeled drugs, metabolic precursors and nuclear medicine contrast agents) by single cells without perturbing endogenous biochemical processes. In this imaging technique, a scintillator crystal (e.g., CdWO 4 ) is placed in close proximity to the radiolabeled cells, where it converts the radioactive decays into optical flashes detectable using a sensitive camera. Using the image reconstruction toolkit provided in this protocol, the flashes can be reconstructed to yield high-resolution images of the radiotracer distribution. With appropriate timing, the three aforementioned imaging modalities may be performed together on a population of live cells, allowing the user to perform parallel functional studies of cell heterogeneity at the single-cell level.

  6. A novel autonomous real-time position method based on polarized light and geomagnetic field.

    Science.gov (United States)

    Wang, Yinlong; Chu, Jinkui; Zhang, Ran; Wang, Lu; Wang, Zhiwen

    2015-04-08

    Many animals exploit polarized light in order to calibrate their magnetic compasses for navigation. For example, some birds are equipped with biological magnetic and celestial compasses enabling them to migrate between the Western and Eastern Hemispheres. The Vikings' ability to derive true direction from polarized light is also widely accepted. However, their amazing navigational capabilities are still not completely clear. Inspired by birds' and Vikings' ancient navigational skills. Here we present a combined real-time position method based on the use of polarized light and geomagnetic field. The new method works independently of any artificial signal source with no accumulation of errors and can obtain the position and the orientation directly. The novel device simply consists of two polarized light sensors, a 3-axis compass and a computer. The field experiments demonstrate device performance.

  7. Central-moment description of polarization for quantum states of light

    DEFF Research Database (Denmark)

    Björk, G.; Söderholm, J.; Kim, Y.-S.

    2012-01-01

    We present a moment expansion for the systematic characterization of the polarization properties of quantum states of light. Specifically,we link the method to themeasurements of the Stokes operator in different directions on the Poincar´e sphere and provide a scheme for polarization tomography w...

  8. Investigation of the state of polarization of light in a single-mode fiber waveguide

    Science.gov (United States)

    Kozel, S. M.; Kreopalov, V. I.; Listvin, V. N.; Glavatskikh, N. A.

    1983-01-01

    An analysis is made of the polarization anisotropy of a single-mode fiber with a twisted elliptic core. The Jones matrix is obtained and the complex function of the state of polarization of light in a fiber is investigated. The results are reported of measurements of the linear and circular birefringence of a borosilicate single-mode glass fiber.

  9. Depth enhancement of multi-layer light field display using polarization dependent internal reflection.

    Science.gov (United States)

    Jo, Na-Young; Lim, Hong-Gi; Lee, Sung-Keun; Kim, Yong-Soo; Park, Jae-Hyeung

    2013-12-02

    A technique to enhance the depth range of the multi-layer light field three-dimensional display is proposed. A set of the optical plates are stacked in front of the conventional multi-layer light field display, creating additional internal reflection for one polarization state. By switching between two orthogonal polarization states in synchronization with the displayed three-dimensional images, the depth range of the display can be doubled. The proposed method is verified experimentally, confirming its feasibility.

  10. Photoemission of Bi_{2}Se_{3} with Circularly Polarized Light: Probe of Spin Polarization or Means for Spin Manipulation?

    Directory of Open Access Journals (Sweden)

    J. Sánchez-Barriga

    2014-03-01

    Full Text Available Topological insulators are characterized by Dirac-cone surface states with electron spins locked perpendicular to their linear momenta. Recent theoretical and experimental work implied that this specific spin texture should enable control of photoelectron spins by circularly polarized light. However, these reports questioned the so far accepted interpretation of spin-resolved photoelectron spectroscopy. We solve this puzzle and show that vacuum ultraviolet photons (50–70 eV with linear or circular polarization indeed probe the initial-state spin texture of Bi_{2}Se_{3} while circularly polarized 6-eV low-energy photons flip the electron spins out of plane and reverse their spin polarization, with its sign determined by the light helicity. Our photoemission calculations, taking into account the interplay between the varying probing depth, dipole-selection rules, and spin-dependent scattering effects involving initial and final states, explain these findings and reveal proper conditions for light-induced spin manipulation. Our results pave the way for future applications of topological insulators in optospintronic devices.

  11. Scanning Miniature Microscopes without Lenses

    Science.gov (United States)

    Wang, Yu

    2009-01-01

    The figure schematically depicts some alternative designs of proposed compact, lightweight optoelectronic microscopes that would contain no lenses and would generate magnified video images of specimens. Microscopes of this type were described previously in Miniature Microscope Without Lenses (NPO - 20218), NASA Tech Briefs, Vol. 22, No. 8 (August 1998), page 43 and Reflective Variants of Miniature Microscope Without Lenses (NPO 20610), NASA Tech Briefs, Vol. 26, No. 9 (September 1999), page 6a. To recapitulate: In the design and construction of a microscope of this type, the focusing optics of a conventional microscope are replaced by a combination of a microchannel filter and a charge-coupled-device (CCD) image detector. Elimination of focusing optics reduces the size and weight of the instrument and eliminates the need for the time-consuming focusing operation. The microscopes described in the cited prior articles contained two-dimensional CCDs registered with two-dimensional arrays of microchannels and, as such, were designed to produce full two-dimensional images, without need for scanning. The microscopes of the present proposal would contain one-dimensional (line image) CCDs registered with linear arrays of microchannels. In the operation of such a microscope, one would scan a specimen along a line perpendicular to the array axis (in other words, one would scan in pushbroom fashion). One could then synthesize a full two-dimensional image of the specimen from the line-image data acquired at one-pixel increments of position along the scan. In one of the proposed microscopes, a beam of unpolarized light for illuminating the specimen would enter from the side. This light would be reflected down onto the specimen by a nonpolarizing beam splitter attached to the microchannels at their lower ends. A portion of the light incident on the specimen would be reflected upward, through the beam splitter and along the microchannels, to form an image on the CCD. If the

  12. Can invertebrates see the e-vector of polarization as a separate modality of light?

    Science.gov (United States)

    Labhart, Thomas

    2016-12-15

    The visual world is rich in linearly polarized light stimuli, which are hidden from the human eye. But many invertebrate species make use of polarized light as a source of valuable visual information. However, exploiting light polarization does not necessarily imply that the electric (e)-vector orientation of polarized light can be perceived as a separate modality of light. In this Review, I address the question of whether invertebrates can detect specific e-vector orientations in a manner similar to that of humans perceiving spectral stimuli as specific hues. To analyze e-vector orientation, the signals of at least three polarization-sensitive sensors (analyzer channels) with different e-vector tuning axes must be compared. The object-based, imaging polarization vision systems of cephalopods and crustaceans, as well as the water-surface detectors of flying backswimmers, use just two analyzer channels. Although this excludes the perception of specific e-vector orientations, a two-channel system does provide a coarse, categoric analysis of polarized light stimuli, comparable to the limited color sense of dichromatic, 'color-blind' humans. The celestial compass of insects employs three or more analyzer channels. However, that compass is multimodal, i.e. e-vector information merges with directional information from other celestial cues, such as the solar azimuth and the spectral gradient in the sky, masking e-vector information. It seems that invertebrate organisms take no interest in the polarization details of visual stimuli, but polarization vision grants more practical benefits, such as improved object detection and visual communication for cephalopods and crustaceans, compass readings to traveling insects, or the alert 'water below!' to water-seeking bugs. © 2016. Published by The Company of Biologists Ltd.

  13. Atomic force and optical near-field microscopic investigations of polarization holographic gratings in a liquid crystalline azobenzene side-chain polyester

    DEFF Research Database (Denmark)

    Ramanujam, P.S.; Holme, N.C.R.; Hvilsted, S.

    1996-01-01

    Atomic force and scanning near-field optical microscopic investigations have been carried out on a polarization holographic grating recorded in an azobenzene side-chain Liquid crystalline polyester. It has been found that immediately following laser irradiation, a topographic surface grating......-field optical microscopic scanning of the grating reveals, however, that the bulk of the film remains optically anisotropic. (C) 1996 American Institute of Physics....

  14. Resolution enhancement method for lensless in-line holographic microscope with spatially-extended light source.

    Science.gov (United States)

    Feng, Shaodong; Wu, Jigang

    2017-10-02

    We propose a resolution enhancement method for lensless in-line holographic microscope (LIHM) with spatially-extended light source, where the resolution is normally deteriorated by the insufficient spatial coherence of the illumination. In our LIHM setup, a light-emitting diode (LED), which was a spatially-extended light source, directly illuminated the sample, and the in-line hologram were recorded by a CMOS imaging sensor located behind the sample. In our holographic reconstruction process, the in-line hologram was first deconvoled with a properly resized image of the LED illumination area, and then back-propagated with scalar diffraction formula to reconstruct the sample image. We studied the hologram forming process and showed that the additional deconvolution process besides normal scalar diffraction reconstruction in LIHM can effectively enhance the imaging resolution. The resolution enhancements capability was calibrated by numerical simulations and imaging experiments with the U.S. air force target as the sample. We also used our LIHM to image the wing of a green lacewing to further demonstrate the capability of our methods for practical imaging applications. Our methods provide a way for LIHM to achieve satisfactory resolution with less stringent requirement for spatial coherence of the source and could reduce the cost for compact imaging system.

  15. Object-based representation and analysis of light and electron microscopic volume data using Blender.

    Science.gov (United States)

    Asadulina, Albina; Conzelmann, Markus; Williams, Elizabeth A; Panzera, Aurora; Jékely, Gáspár

    2015-07-25

    Rapid improvements in light and electron microscopy imaging techniques and the development of 3D anatomical atlases necessitate new approaches for the visualization and analysis of image data. Pixel-based representations of raw light microscopy data suffer from limitations in the number of channels that can be visualized simultaneously. Complex electron microscopic reconstructions from large tissue volumes are also challenging to visualize and analyze. Here we exploit the advanced visualization capabilities and flexibility of the open-source platform Blender to visualize and analyze anatomical atlases. We use light-microscopy-based gene expression atlases and electron microscopy connectome volume data from larval stages of the marine annelid Platynereis dumerilii. We build object-based larval gene expression atlases in Blender and develop tools for annotation and coexpression analysis. We also represent and analyze connectome data including neuronal reconstructions and underlying synaptic connectivity. We demonstrate the power and flexibility of Blender for visualizing and exploring complex anatomical atlases. The resources we have developed for Platynereis will facilitate data sharing and the standardization of anatomical atlases for this species. The flexibility of Blender, particularly its embedded Python application programming interface, means that our methods can be easily extended to other organisms.

  16. Polarization Optics

    OpenAIRE

    Fressengeas, Nicolas

    2010-01-01

    The physics of polarization optics *Polarized light propagation *Partially polarized light; DEA; After a brief introduction to polarization optics, this lecture reviews the basic formalisms for dealing with it: Jones Calculus for totally polarized light and Stokes parameters associated to Mueller Calculus for partially polarized light.

  17. Improving spatial resolution of the light field microscope with Fourier ptychography

    Science.gov (United States)

    Tani, Yoshitake; Usuki, Shin; Miura, Kenjiro T.

    2017-09-01

    Light field microscope (LFM) is an optical microscope capable of obtaining images having large depth of field with different viewpoints. By using the parallax of these multi-view images, it is possible to reconstruct the 3D sample. However, the sampling interval of this multi-viewpoint image depends on the pitch interval of the microlens array, so the spatial resolution is low, and the accuracy of the 3D sample to be reconstructed is also low. Conventional research has a method of increasing the spatial resolution by subpixel-shifted multiple images. However, this method has problems such as the necessity of mechanical operation and high cost. Therefore, we propose applying Fourier ptychography to the LFM. Fourier ptychography is a technique to obtain high spatial resolution images by joining images obtained by irradiating samples from different angles using LED arrays in Fourier space. Fourier ptychography does not require mechanical scanning and is high throughput and low cost. In addition, Fourier ptycoography is possible to obtain phase information on a sample, and it is also possible to obtain a fine 3D sample. We propose a method to generate high spatial resolution multiview images using Fourier ptychography and reconstruct highly accurate 3D sample from those images. In this research, we experiment with the original LFM and verify the effect.

  18. A scanning photoelectron microscope (SPEM) at the National Synchrotron Light Source (NSLS)

    International Nuclear Information System (INIS)

    Ade, H.; Kirz, J.; Hulbert, S.; Johnson, E.; Anderson, E.; Kern, D.; Brookhaven National Lab., Upton, NY; Lawrence Berkeley Lab., CA; International Business Machines Corp., Yorktown Heights, NY

    1989-01-01

    We are in the process of developing and commissioning a scanning photoelectron microscope (SPEM) at the X1A beamline of the National Synchrotron Light Source (NSLS). It is designed to make use of the Soft X-ray Undulator (SXU) at the NSLS. This high brightness source illuminates a Fresnel zone plate, which forms a focused probe, ≤ 0.2μm in size, on the specimen surface. A grating monochromator selects the photon energy in the 400-800 eV range with an energy resolution of better than 1 eV. The expected flux in the focus is in the 5 x 10 7 - 10 9 photons/s range. A single pass Cylindrical Mirror Analyzer (CMA) is used to record photoemission spectra, or to form an image within a fixed electron energy bandwidth as the specimen is mechanically scanned. As a first test, a 1000 mesh Au grid was successfully imaged with a resolution of about 1μm and the CMA tuned to the Au 4 f photoelectron peak. Once it is commissioned, a program is planned which will utilize the microscope to study beam sensitive systems, such as thin oxide/sub-oxide films of alumina and silica, and ultimately various adsorbates on these films. 14 refs., 4 figs

  19. [Impact of Light Polarization on the Measurement of Water Particulate Backscattering Coefficient].

    Science.gov (United States)

    Liu, Jia; Gong, Fang; He, Xian-qiang; Zhu, Qian-kun; Huang, Hai-qing

    2016-01-01

    Particulate backscattering coefficient is a main inherent optical properties (IOPs) of water, which is also a determining factor of ocean color and a basic parameter for inversion of satellite ocean color remote sensing. In-situ measurement with optical instruments is currently the main method for obtaining the particulate backscattering coefficient of water. Due to reflection and refraction by the mirrors in the instrument optical path, the emergent light source from the instrument may be partly polarized, thus to impact the measurement accuracy of water backscattering coefficient. At present, the light polarization of measuring instruments and its impact on the measurement accuracy of particulate backscattering coefficient are still poorly known. For this reason, taking a widely used backscattering coefficient measuring instrument HydroScat6 (HS-6) as an example in this paper, the polarization characteristic of the emergent light from the instrument was systematically measured, and further experimental study on the impact of the light polarization on the measurement accuracy of the particulate backscattering coefficient of water was carried out. The results show that the degree of polarization(DOP) of the central wavelength of emergent light ranges from 20% to 30% for all of the six channels of the HS-6, except the 590 nm channel from which the DOP of the emergent light is slightly low (-15%). Therefore, the emergent light from the HS-6 has significant polarization. Light polarization has non-neglectable impact on the measurement of particulate backscattering coefficient, and the impact degree varies with the wave band, linear polarization angle and suspended particulate matter (SPM) concentration. At different SPM concentrations, the mean difference caused by light polarization can reach 15.49%, 11.27%, 12.79%, 14.43%, 13.76%, and 12.46% in six bands, 420, 442, 470, 510, 590, and 670 nm, respectively. Consequently, the impact of light polarization on the

  20. Energy-dependent microscopic optical potential for scattering of nucleons on light nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Farag, M.Y.H.; Esmael, E.H. [Cairo University, Physics Department, Faculty of Science, Giza (Egypt); Maridi, H.M. [Cairo University, Physics Department, Faculty of Science, Giza (Egypt); Taiz University, Physics Department, Faculty of Applied Science, Taiz (Yemen)

    2014-06-15

    We present an energy-dependent microscopic optical model potential for elastic scattering of nucleons on light nuclei. The single-folding model is used for the real part of the optical potential (OP), while the imaginary part is derived within the high-energy approximation theory. The energy dependence of the OP is determined from the parameterization of the volume integrals those calculated from the best-fit OP that fit the experimental data of the cross sections and analyzing powers. This energy-dependent OP is successfully applied to analyze the proton elastic scattering of {sup 4,6,i8}He, {sup 6,7}Li, and {sup 9,10}Be nuclei at low and intermediate incident energies up to 200MeV/nucleon. (orig.)

  1. Compact soft x-ray microscope using a gas-discharge light source.

    Science.gov (United States)

    Benk, Markus; Bergmann, Klaus; Schäfer, David; Wilhein, Thomas

    2008-10-15

    We report on a soft x-ray microscope using a gas-discharge plasma with pseudo spark-like electrode geometry as a light source. The source produces a radiant intensity of 4 x 10(13) photons/(sr pulse) for the 2.88 nm emission line of helium-like nitrogen. At a demonstrated 1 kHz repetition rate a brilliance of 4.3 x 10(9) photons/(microm2 sr s) is obtained for the 2.88 nm line. Ray-tracing simulations show that, employing an adequate grazing incidence collector, a photon flux of 1 x 10(7) photons/(microm2 s) can be achieved with the current source. The applicability of the presented pinch plasma concept to soft x-ray microscopy is demonstrated in a proof-of-principle experiment.

  2. Interaction of electrons with light metal hydrides in the transmission electron microscope.

    Science.gov (United States)

    Wang, Yongming; Wakasugi, Takenobu; Isobe, Shigehito; Hashimoto, Naoyuki; Ohnuki, Somei

    2014-12-01

    Transmission electron microscope (TEM) observation of light metal hydrides is complicated by the instability of these materials under electron irradiation. In this study, the electron kinetic energy dependences of the interactions of incident electrons with lithium, sodium and magnesium hydrides, as well as the constituting element effect on the interactions, were theoretically discussed, and electron irradiation damage to these hydrides was examined using in situ TEM. The results indicate that high incident electron kinetic energy helps alleviate the irradiation damage resulting from inelastic or elastic scattering of the incident electrons in the TEM. Therefore, observations and characterizations of these materials would benefit from increased, instead decreased, TEM operating voltage. © The Author 2014. Published by Oxford University Press on behalf of The Japanese Society of Microscopy. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  3. A depth estimation method based on geometric transformation for stereo light microscope.

    Science.gov (United States)

    Fan, Shengli; Yu, Mei; Wang, Yigang; Jiang, Gangyi

    2014-01-01

    Stereo light microscopes (SLM) with narrow vision and shallow depth of field are widely used in micro-domain research. In this paper, we propose a depth estimation method of micro objects based on geometric transformation. By analyzing the optical imaging geometry, the definition of geometric transformation distance is given and the depth-distance relation express is obtained. The parameters of geometric transformation and express are calibrated with calibration board images captured in aid of precise motorized stage. The depth of micro object can be estimated by calculating the geometric transformation distance. The proposed depth-distance relation express is verified using an experiment in which the depth map of an Olanzapine tablet surface is reconstructed.

  4. Selective scanning tunneling microscope light emission from rutile phase of VO2.

    Science.gov (United States)

    Sakai, Joe; Kuwahara, Masashi; Hotsuki, Masaki; Katano, Satoshi; Uehara, Yoichi

    2016-09-28

    We observed scanning tunneling microscope light emission (STM-LE) induced by a tunneling current at the gap between an Ag tip and a VO2 thin film, in parallel to scanning tunneling spectroscopy (STS) profiles. The 34 nm thick VO2 film grown on a rutile TiO2 (0 0 1) substrate consisted of both rutile (R)- and monoclinic (M)-structure phases of a few 10 nm-sized domains at room temperature. We found that STM-LE with a certain photon energy of 2.0 eV occurs selectively from R-phase domains of VO2, while no STM-LE was observed from M-phase. The mechanism of STM-LE from R-phase VO2 was determined to be an interband transition process rather than inverse photoemission or inelastic tunneling processes.

  5. Image processing of muscle striations below the resolution limit of the light microscope

    International Nuclear Information System (INIS)

    Burns, D.H.; Holdren, D.N.; Periasamy, A.; Everts, W.C.; Pollack, G.H.

    1985-01-01

    We describe the use of digital deconvolution in the study of muscle striations below the resolution imposed by the optical diffraction of our video light microscope. To use deconvolution procedures on muscle images, the transfer function of the optical system is first characterized. This is accomplished by imaging a step object and fitting the image with the combination of a first order Bessel and Guassian function using a non-linear least squares approach. Due to the ill-conditioned nature of deconvolution, however, ambiguity in the reconstruction is sometimes found. To allow better estimation of the true object, separate deconvolution approaches are used and the reconstructions compared. In this manner, the fine structure of muscle striations is determined

  6. Laser based imaging of time depending microscopic scenes with strong light emission

    Science.gov (United States)

    Hahlweg, Cornelius; Wilhelm, Eugen; Rothe, Hendrik

    2011-10-01

    Investigating volume scatterometry methods based on short range LIDAR devices for non-static objects we achieved interesting results aside the intended micro-LIDAR: the high speed camera recording of the illuminated scene of an exploding wire -intended for Doppler LIDAR tests - delivered a very effective method of observing details of objects with extremely strong light emission. As a side effect a schlieren movie is gathered without any special effort. The fact that microscopic features of short time processes with high emission and material flow might be imaged without endangering valuable equipment makes this technique at least as interesting as the intended one. So we decided to present our results - including latest video and photo material - instead of a more theoretical paper on our progress concerning the primary goal.

  7. Light-induced spin polarizations in quantum rings

    NARCIS (Netherlands)

    Joibari, F.K.; Blanter, Y.M.; Bauer, G.E.W.

    2014-01-01

    Nonresonant circularly polarized electromagnetic radiation can exert torques on magnetizations by the inverse Faraday effect (IFE). Here, we discuss the enhancement of IFE by spin-orbit interactions. We illustrate the principle by studying a simple generic model system, i.e., the

  8. A versatile maskless microscope projection photolithography system and its application in light-directed fabrication of DNA microarrays

    OpenAIRE

    Naiser, Thomas; Mai, Timo; Michel, Wolfgang; Ott, Albrecht

    2006-01-01

    We present a maskless microscope projection lithography system (MPLS), in which photomasks have been replaced by a Digital Micromirror Device type spatial light modulator (DMD, Texas Instruments). Employing video projector technology high resolution patterns, designed as bitmap images on the computer, are displayed using a micromirror array consisting of about 786000 tiny individually addressable tilting mirrors. The DMD, which is located in the image plane of an infinity corrected microscope...

  9. Planetary systems in polarized light: Debris disk observations and instrumentation

    Science.gov (United States)

    Millar-Blanchaer, Maxwell A.

    Understanding planet formation is one of the major challenges of modern astronomy. Polarimetry is a powerful tool with which we can confront this challenge. In particular, polarimetric observations can be useful for imaging debris disks and characterizing exoplanet atmospheres. With that in mind, this thesis has been constructed with two main aspects: i) observational studies of two debris disk systems, beta Pic and HD 157587, using the Gemini Planet Imager and ii) the characterization and testing of a new type of diffraction grating, called a polarization grating, that we plan to use for future observations of exoplanet atmospheres. The Gemini Planet Imager is a high-contrast imager that includes a polarimetry mode designed to image circumstellar disks. Here we detail the development of new data analysis techniques that reduce systematics and noise in processed GPI data. We apply these techniques to observations of the beta Pic and HD 157587 debris disks and then fit each disk image to a geometric disk model. The beta Pic disk model's morphology cannot be explained by interactions with the planet beta Pic b, and the presence of a second planet could be invoked to explain the discrepancy. In the case of HD 157587, the disk model's geometric centre is offset from the location of the star, which could be explained by a perturbing planet. Characterization of the planets' interactions with their debris disks is a critical method to gain more information about these two systems. The second component of this thesis focuses on polarization gratings, thin film optical devices that can simultaneously act as polarizing beam splitters and as spectral dispersive elements. Moreover, they can be designed for high diffraction efficiency across a broad wavelength range. These features make polarization gratings useful for many types of astronomical observations. We have carried out laboratory and on-sky test observations using a polarization grating optimized for visible

  10. The HIP 79977 debris disk in polarized light

    Science.gov (United States)

    Engler, N.; Schmid, H. M.; Thalmann, Ch.; Boccaletti, A.; Bazzon, A.; Baruffolo, A.; Beuzit, J. L.; Claudi, R.; Costille, A.; Desidera, S.; Dohlen, K.; Dominik, C.; Feldt, M.; Fusco, T.; Ginski, C.; Gisler, D.; Girard, J. H.; Gratton, R.; Henning, T.; Hubin, N.; Janson, M.; Kasper, M.; Kral, Q.; Langlois, M.; Lagadec, E.; Ménard, F.; Meyer, M. R.; Milli, J.; Mouillet, D.; Olofsson, J.; Pavlov, A.; Pragt, J.; Puget, P.; Quanz, S. P.; Roelfsema, R.; Salasnich, B.; Siebenmorgen, R.; Sissa, E.; Suarez, M.; Szulagyi, J.; Turatto, M.; Udry, S.; Wildi, F.

    2017-11-01

    Context. Debris disks are observed around 10 to 20% of FGK main-sequence stars as infrared excess emission. They are important signposts for the presence of colliding planetesimals and therefore provide important information about the evolution of planetary systems. Direct imaging of such disks reveals their geometric structure and constrains their dust-particle properties. Aims: We present observations of the known edge-on debris disk around HIP 79977 (HD 146897) taken with the ZIMPOL differential polarimeter of the SPHERE instrument. We measure the observed polarization signal and investigate the diagnostic potential of such data with model simulations. Methods: SPHERE-ZIMPOL polarimetric data of the 15 Myr-old F star HIP 79977 (Upper Sco, 123 pc) were taken in the Very Broad Band (VBB) filter (λc = 735 nm, Δλ = 290 nm) with a spatial resolution of about 25 mas. Imaging polarimetry efficiently suppresses the residual speckle noise from the AO system and provides a differential signal with relatively small systematic measuring uncertainties. We measure the polarization flux along and perpendicular to the disk spine of the highly inclined disk for projected separations between 0.2'' (25 AU) and 1.6'' (200 AU). We perform model calculations for the polarized flux of an optically thin debris disk which are used to determine or constrain the disk parameters of HIP 79977. Results: We measure a polarized flux contrast ratio for the disk of (Fpol)disk/F∗ = (5.5 ± 0.9) × 10-4 in the VBB filter. The surface brightness of the polarized flux reaches a maximum of SBmax = 16.2 mag arcsec-2 at a separation of 0.2''-0.5'' along the disk spine with a maximum surface brightness contrast of 7.64 mag arcsec-2. The polarized flux has a minimum near the star 1''. This can be explained by a radial blow-out of small grains. The data are modelled as a circular dust belt with a well defined disk inclination I = 85( ± 1.5)° and a radius between r0 = 60 and 90 AU. The radial

  11. A stereovision model applied in bio-micromanipulation system based on stereo light microscope.

    Science.gov (United States)

    Wang, Yuezong

    2017-12-01

    A bio-micromanipulation system is designed for manipulating micro-objects with a length scale of tens or hundreds of microns based on stereo light microscope. The world coordinate reconstruction of points on the surface of micro-objects is an important goal for the micromanipulation. Traditional pinhole camera model is applied widely in macrocomputer vision. However, this model will output bad data with remarkable error if it is directly used to reconstruct three-dimensional world coordinates for stereo light microscope. Therefore, a novel and improved pinhole camera model applied in bio-micromanipulation system is proposed in this article. The new model is composed of binocular-pinhole model and error-correction model. The binocular-pinhole model is used to output the basic world coordinates. The error-correction model is used to correct the errors from the basic world coordinates and outputs the final high-precision world coordinates. The results show that the new model achieves a precision of 0.01 mm in the X direction, 0.01 mm in the Y direction, and 0.015 mm in the Z direction within a maximum reconstruction distance of 4.1 mm in the X direction, 2.9 mm in the Y direction, and 2.25 mm in the Z direction, and that traditional pinhole camera model achieves a lower and unsatisfactory precision of about 0.1 mm. © 2017 Wiley Periodicals, Inc.

  12. Retrieving the polarization information for satellite-to-ground light communication

    International Nuclear Information System (INIS)

    Tao, Qiangqiang; Guo, Zhongyi; Xu, Qiang; Gao, Jun; Jiao, Weiyan; Wang, Xinshun; Qu, Shiliang

    2015-01-01

    In this paper, we have investigated the reconstruction of the polarization states (degree of polarization (DoP) and angle of polarization (AoP)) of the incident light which passed through a 10 km atmospheric medium between the satellite and the Earth. Here, we proposed a more practical atmospheric model in which the 10 km atmospheric medium is divided into ten layers to be appropriate for the Monte Carlo simulation algorithm. Based on this model, the polarization retrieve (PR) method can be used for reconstructing the initial polarization information effectively, and the simulated results demonstrate that the mean errors of the retrieved DoP and AoP are very close to zero. Moreover, the results also show that although the atmospheric medium system is fixed, the Mueller matrices for the downlink and uplink are completely different, which shows that the light transmissions in the two links are irreversible in the layered atmospheric medium system. (paper)

  13. Circularly polarized light interaction in topological insulators investigated by time-resolved ARPES

    Science.gov (United States)

    Bugini, D.; Hedayat, H.; Boschini, F.; Yi, H.; Chen, C.; Zhou, X.; Manzoni, C.; Dallera, C.; Cerullo, G.; Carpene, E.

    2017-10-01

    Topological Insulators (TI) represent a hot-topic for both basic physics and promising applications because of the in-plane spin-polarized surface states (TSS) arising within the bulk insulating energy gap. The backscattering protection and the control of the spin polarization using ultrashort light pulses open new scenarios in the use of this class of materials for future opto-spintronic devices. Using time- and angle-resolved photoemission spectroscopy on Sb x Bi(2‑x )Se y Te(3‑y ) class we studied the response of spin-polarized electrons to ultrashort circularly-polarized pulses. Here, we report for the first time the experimental evidence of a direct coupling between light and empty topological surface states (ESS) and the establishment of a flow of spin-polarized electrons in k-space i.e. a photon-induced spin-current.

  14. Evaluation of macroscopic polarization and actuation abilities of electrostrictive dipolar polymers using the microscopic Debye/Langevin formalism

    International Nuclear Information System (INIS)

    Capsal, Jean-Fabien; Lallart, Mickaël; Galineau, Jeremy; Cottinet, Pierre-Jean; Sebald, Gaël; Guyomar, Daniel

    2012-01-01

    Electrostrictive polymers, as an important category of electroactive polymers, are known to have non-linear response in terms of actuation that strongly affects their dynamic performance and limits their applications. Very few models exist in the literature, and even fewer are capable of making reliable predictions under an electric field. In this paper, electrostrictive strain of dipolar polymeric systems is discussed through constitutive equations derived from the Boltzmann statistics and Debye/Langevin formalism. Macroscopic polarization is expressed as a function of the inherent microscopic parameters of the dielectric material. Electrostrictive strain, polarization and dielectric permittivity are described well by the model in terms of dipole moment and saturation of dipole orientation, allowing the physical definition of the electrostrictive coefficient Q. Maxwell forces generated by dipolar orientation inducing surface charges are also used to explain the electrostrictive strain of polymers. The assessment of this analysis through a comparison with experimental data shows good agreement between reported values and theoretical predictions. These materials are generally used in low-frequency applications, thus the interfacial phenomena that are responsible for low saturation electric field should not be omitted so as not to underestimate or overestimate the low electric field response of the electrostrictive strain. (paper)

  15. [Scanning electron microscopy and light microscopy under polarized light of a submandibular salivary gland calculus].

    Science.gov (United States)

    Traini, T; Murmura, G; Giammaria, G; Ciavarelli, L; Caputi, S

    2001-05-01

    The salivary calculus is an ancient pathologic condition, called sublingual stone by Hyppocrates. It is well-defined from a anatomo-pathologic, diagnostic and topographic viewpoint, though some pathogenesis-related doubts still exist. This work aims at relating the micro-morpho-structural aspect of a salivary calculus of remarkable dimensions with the current calculogenetic hypotheses. A 1.1 g salivary calculus removed from the initial section of Wrthon s duct in the right-hand submandibular gland of a 42 year old male has been studied. Following the fixation in 4% buffered formalin and the inclusion in resin, it was serially sectioned in 15-20 micron slices. Some sections were coloured with toluidine blue O and acid fuchsin. The exeresis of the calculus was carried out intraorally, with marsupialization under local anesthesia. The analysis was performed using a SEM with backscattered electrons and a polarised and transmitted light microscope. The investigations have outlined the presence of various organic cores and a concentric, stratiform architecture interrupted by radial elements. The formation of this calculus may be due to mixed secondary lithiasis resulting from the formation of colloids and crystalloids.

  16. What makes single-helical metamaterials generate "pure" circularly polarized light?

    Science.gov (United States)

    Wu, Lin; Yang, ZhenYu; Zhao, Ming; Zhang, Peng; Lu, ZeQing; Yu, Yang; Li, ShengXi; Yuan, XiuHua

    2012-01-16

    Circular polarizers with left-handed helical metamaterials can transmit right-handed circularly polarized (RCP) light with few losses. But a certain amount of left-handed circularly polarized (LCP) light will occur in the transmitted light, which is the noise of the circular polarizer. Therefore, we defined the ratio of the RCP light intensity to the LCP light intensity as the signal-to-noise (S/N) ratio. In our previous work, it's found that circular polarizers with multi-helical metamaterials have two orders higher S/N ratios than that of single-helical metamaterials. However, it has been a great challenge to fabricate such multi-helical structures with micron or sub-micron feature sizes. Is it possible for the single-helical metamaterials to obtain equally high S/N ratios as the multi-helical ones? To answer this question, we systematically investigated the influences of structure parameters of single-helical metamaterials on the S/N ratios using the finite-different time-domain (FDTD) method. It was found that the single-helical metamaterials can also reach about 30dB S/N ratios, which are equal to the multi-helical ones. Furthermore, we explained the phenomenon by the antenna theory and optimized the performances of the single-helical circular polarizers.

  17. Selective Deflection of Polarized Light Via Coherently Driven Four-Level Atoms in a Double-Λ Configuration

    International Nuclear Information System (INIS)

    Guo Yu

    2010-01-01

    We study the interaction of a weak probe field, having two circular polarized components, i.e., σ - and σ + polarization, with an optically dense medium of four-level atoms in a double-Λ configuration, which is mediated by the electromagnetically induced transparency with a polarized control light with spatially inhomogeneous profile. We analyse the deflection of the polarized probe light and we find that we can selectively determine which circular component will be deflected after the polarized probe light enters the atom medium via adjusting the polarization and detuning of the control field. (electromagnetism, optics, acoustics, heat transfer, classical mechanics, and fluid dynamics)

  18. Field spectrometer measurement errors in presence of partially polarized light; evaluation of ground truth measurement accuracy.

    Science.gov (United States)

    Lévesque, Martin P; Dissanska, Maria

    2016-11-28

    Considering that natural light is always partially polarized (reflection, Rayleigh scattering, etc.) and the alteration of the spectral response of spectrometers due to the polarization, some concerns were raised about the accuracy and variability of spectrometer outdoor measurements in field campaigns. We demonstrated by simple experiments that, in some circumstances, spectral measurements can be affected by the polarization. The signal variability due to polarization sensitivity of the spectrometer for the measured sample was about 5-10%. We noted that, measuring surfaces at right angle (a frequently used measurement protocol) minimized the problems due to polarization, producing valid results. On the other hand, measurements acquired with a slant angle are more or less accurate; an important proportion of the signal variability is due to the polarization. Direct sun reflection and reflection from close objects must be avoided.

  19. A test of the equivalence principle with polarized light

    International Nuclear Information System (INIS)

    Lesche, B.; Bedran, M.L.

    1987-01-01

    The behaviour of electromagnetic radiation in the Schwarzschild metric of the sun is studied with the presence of a non-minimal coupling term of electromagnetism and gravity. An anomalous deflection is predicted, as well as a polarization effect. These effects can be used to obtain experimental upper bounds for the coupling constant of the non-minimal coupling. The strength of these upper bounds is discussed. (author) [pt

  20. Polarized light scattering as a probe for changes in chromosome structure

    Energy Technology Data Exchange (ETDEWEB)

    Shapiro, Daniel Benjamin [Univ. of California, Berkeley, CA (United States)

    1993-10-01

    Measurements and calculations of polarized light scattering are applied to chromosomes. Calculations of the Mueller matrix, which completely describes how the polarization state of light is altered upon scattering, are developed for helical structures related to that of chromosomes. Measurements of the Mueller matrix are presented for octopus sperm heads, and dinoflagellates. Comparisons of theory and experiment are made. A working theory of polarized light scattering from helices is developed. The use of the first Born approximation vs the coupled dipole approximation are investigated. A comparison of continuous, calculated in this work, and discrete models is also discussed. By comparing light scattering measurements with theoretical predictions the average orientation of DNA in an octopus sperm head is determined. Calculations are made for the Mueller matrix of DNA plectonemic helices at UV, visible and X-ray wavelengths. Finally evidence is presented that the chromosomes of dinoflagellates are responsible for observed differential scattering of circularly-polarized light. This differential scattering is found to vary in a manner that is possibly correlated to the cell cycle of the dinoflagellates. It is concluded that by properly choosing the wavelength probe polarized light scattering can provide a useful tool to study chromosome structure.

  1. Automated, highly reproducible, wide-field, light-based cortical mapping method using a commercial stereo microscope and its applications.

    Science.gov (United States)

    Jiang, Su; Liu, Ya-Feng; Wang, Xiao-Min; Liu, Ke-Fei; Zhang, Ding-Hong; Li, Yi-Ding; Yu, Ai-Ping; Zhang, Xiao-Hui; Zhang, Jia-Yi; Xu, Jian-Guang; Gu, Yu-Dong; Xu, Wen-Dong; Zeng, Shao-Qun

    2016-09-01

    We introduce a more flexible optogenetics-based mapping system attached on a stereo microscope, which offers automatic light stimulation to individual regions of interest in the cortex that expresses light-activated channelrhodopsin-2 in vivo . Combining simultaneous recording of electromyography from specific forelimb muscles, we demonstrate that this system offers much better efficiency and precision in mapping distinct domains for controlling limb muscles in the mouse motor cortex. Furthermore, the compact and modular design of the system also yields a simple and flexible implementation to different commercial stereo microscopes, and thus could be widely used among laboratories.

  2. Scanning tunnelling microscope light emission: Finite temperature current noise and over cut-off emission.

    Science.gov (United States)

    Kalathingal, Vijith; Dawson, Paul; Mitra, J

    2017-06-14

    The spectral distribution of light emitted from a scanning tunnelling microscope junction not only bears its intrinsic plasmonic signature but is also imprinted with the characteristics of optical frequency fluc- tuations of the tunnel current. Experimental spectra from gold-gold tunnel junctions are presented that show a strong bias (V b ) dependence, curiously with emission at energies higher than the quantum cut-off (eV b ); a component that decays monotonically with increasing bias. The spectral evolution is explained by developing a theoretical model for the power spectral density of tunnel current fluctuations, incorporating finite temperature contribution through consideration of the quantum transport in the system. Notably, the observed decay of the over cut-off emission is found to be critically associated with, and well explained in terms of the variation in junction conductance with V b . The investigation highlights the scope of plasmon-mediated light emission as a unique probe of high frequency fluctuations in electronic systems that are fundamental to the electrical generation and control of plasmons.

  3. Three-dimensional imaging of trapped cold atoms with a light field microscope.

    Science.gov (United States)

    Lott, Gordon E; Marciniak, Michael A; Burke, John H

    2017-11-01

    This research images trapped atoms in three dimensions, utilizing light field imaging. Such a system is of interest in the development of atom interferometer accelerometers in dynamic systems where strictly defined focal planes may be impractical. In this research, a light field microscope was constructed utilizing a Lytro Development Kit micro lens array and sensor. It was used to image fluorescing rubidium atoms in a magneto optical trap. The three-dimensional (3D) volume of the atoms is reconstructed using a modeled point spread function (PSF), taking into consideration that the low magnification (1.25) of the system changed typical assumptions used in the optics model for the PSF. The 3D reconstruction is analyzed with respect to a standard off-axis fluorescence image. Optical axis separation between two atom clouds is measured to a 100 μm accuracy in a 3 mm deep volume, with a 16 μm in-focus standard resolution with a 3.9 mm by 3.9 mm field of view. Optical axis spreading is observed in the reconstruction and discussed. The 3D information can be used to determine properties of the atom cloud with a single camera and single image, and can be applied anywhere 3D information is needed but optical access may be limited.

  4. A study on the effect of thiotepa on mice spermatogenesis using light and electronic microscope.

    Science.gov (United States)

    Nejad, D M; Rad, J S; Roshankar, L; Karimipor, M; Ghanbari, A A; Aazami, A; Valilou, M R

    2008-08-01

    The present study was designed to explore the spermatogenic effect of intraperitoneal administration of thiotepa in mice. It is known the chemotherapy could affect testicular function and result in infertility. There are few reports on the side effect of thiotepa on spermatogenesis when are used as anticancer drug. Therefore, in the present study the effect of thiotepa on spermatogenesis was evaluated by electron microscopy. A total of 20 balb/c mice were used in this study. They were divided into control and thiotepa treated groups. Thiotepa was administrated as 2.5 mg kg(-1) for 5 days. The mice were sacrificed after 5 weeks and testicular specimens were removed, fixed in boueins fixative and 2.5% Glutaraldehide then prepared for light and electron microscopic study. Light microscopy showed that the thickness of germinal epithelium was decreased in thiotepa treated group and many seminiferous tubules have lost germinal cells. Electron microscopy revealed that in experimental group several intercellular spaces appeared between spermatogonial and sertoli cells. The basement membrane became irregular and intercellular vacuoles were present in sertoli and spermatogonial cells. Nuclear chromatin was condensed and there were several vacuolated mitochondria. It was indicated that thiotepa affected testicular germinal epithelium by both cytotoxic effect and induction of apoptosis.

  5. The mechanism of light emission from a scanning tunnelling microscope operating in air.

    Science.gov (United States)

    Rogez, B; Cao, S; Dujardin, G; Comtet, G; Moal, E Le; Mayne, A; Boer-Duchemin, E

    2016-11-18

    The scanning tunnelling microscope (STM) may be used as a low-energy, electrical nanosource of surface plasmon polaritons and light. In this article, we demonstrate that the optimum mode of operation of the STM for maximum photon emission is completely different in air than in vacuum. To this end, we investigate the emission of photons, the variation in the relative tip-sample distance and the measured current as a function of time for an STM operating in air. Contrary to the case of an STM operating in vacuum, the measured current between the tip and sample for an STM in air is very unstable (rapidly fluctuating in time) when the applied voltage between the tip and sample is in the ∼1.5-3 V range (i.e., in the energy range of visible photons). The photon emission occurs in short (50 μs) bursts when the STM tip is closest to the sample. The current instabilities are shown to be a key ingredient for producing intense light emission from an STM operating in air (photon emission rate several orders of magnitude higher than for stable current). These results are explained in terms of the interplay between the tunnel current and the electrochemical current in the ubiquitous thin water layer that exists when working in air.

  6. Dynamically Switching the Polarization State of Light Based on the Phase Transition of Vanadium Dioxide

    Science.gov (United States)

    Jia, Zhi-Yong; Shu, Fang-Zhou; Gao, Ya-Jun; Cheng, Feng; Peng, Ru-Wen; Fan, Ren-Hao; Liu, Yongmin; Wang, Mu

    2018-03-01

    There have been great endeavors devoted to manipulating the polarization state of light by plasmonic nanostructures in recent decades. However, the topic of active polarizers has attracted much less attention. We present a composite plasmonic nanostructure consisting of vanadium dioxide that can dynamically modulate the polarization state of the reflected light through a thermally induced phase transition of vanadium dioxide. We design a system consisting of anisotropic plasmonic nanostructures with vanadium dioxide that exhibits distinct reflections subjected to different linearly polarized incidence at room temperature and in the heated state. Under a particular linearly polarized incidence, the polarization state of the reflected light changes at room temperature, and reverts to its original polarization state above the phase-transition temperature. The composite structure can also be used to realize a dynamically switchable infrared image, wherein a pattern can be visualized at room temperature while it disappears above the phase-transition temperature. The composite structure could be potentially used for versatile optical modulators, molecular detection, and polarimetric imaging.

  7. Muscle pathology in myotonic dystrophy: light and electron microscopic investigation in eighteen patients.

    Science.gov (United States)

    Nadaj-Pakleza, A; Lusakowska, A; Sułek-Piątkowska, A; Krysa, W; Rajkiewicz, M; Kwieciński, H; Kamińska, A

    2011-05-01

    Myotonic dystrophy (DM) is the most common muscular dystrophy in adults. Two known genetic subtypes include DM1 (myotonic dystrophy type 1) and DM2 (myotonic dystrophy type 2). Genetic testing is considered as the only reliable diagnostic criterion in myotonic dystrophies. Relatively little is known about DM1 and DM2 myopathology. Thus, the aim of our study was to characterise light and electron microscopic features of DM1 and DM2 in patients with genetically proven types of the disease. We studied 3 DM1 cases and 15 DM2 cases from which muscle biopsies were taken for diagnostic purposes during the period from 1973 to 2006, before genetic testing became available at our hospital. The DM1 group included 3 males (age at biopsy 15-19). The DM2 group included 15 patients (5 men and 10 women, age at biopsy 26-60). The preferential type 1 fibre atrophy was seen in all three DM1 cases in light microscopy, and substantial central nucleation was present in two biopsies. Electron microscopy revealed central nuclei in all three examined muscle biopsies. No other structural or degenerative changes were detected, probably due to the young age of our patients. Central nucleation, prevalence of type 2 muscle fibres, and the presence of pyknotic nuclear clumps were observed in DM2 patients in light microscopy. Among the ultrastructural abnormalities observed in our DM2 group, the presence of internal nuclei, severely atrophied muscle fibres, and lipofuscin accumulation were consistent findings. In addition, a variety of ultrastructural abnormalities were identified by us in DM2. It appears that no single ultrastructural abnormality is characteristic for the DM2 muscle pathology. It seems, however, that certain constellations of morphological changes might be indicative of certain types of myotonic dystrophy.

  8. Dinosaur demise in light of their alleged perennial polar residency

    Science.gov (United States)

    Lewy, Zeev

    2017-10-01

    The end-Cretaceous biological crisis is represented by the demise of the non-avian dinosaurs. However, most crucial biologically was the elimination of the photosynthesizing marine phyto- and zooplankton forming the base of the marine food chain. Their abrupt demise attests to sunlight screening darkening the atmosphere for a few years. Alvarez et al. (Science 208:1095-1108, 1980. doi: 10.1126/science.208.44) noticed in deep marine end-Cretaceous sediments an anomalous rise in the chemical element iridium (Ir), which is rare on planet Earth and thus suggests an extraterrestrial origin through an impact of a large asteroid. This impact would have ejected enormous quantities of particles and aerosols, shading the solar illumination as attested to by the elimination of the marine photosynthesizing plankton. Such a dark period must have affected life on land. The apparent cold-blooded non-avian dinosaurs, which were used to living in open terrains to absorb the solar illumination, became inactive during the dark period and were incapable of withstanding predators. This was in contrast to cold-blooded crocodilians, turtles and lizards that could hide in refuge sites on land and in the water. Dinosaur relics discovered in Cretaceous Polar Regions were attributed to perennial residents, surviving the nearly half-year-long dark winter despite their ability to leave. The polar concentrations of disarticulated dinosaur bones were suggested as having resulted from a catastrophic burial of a population by floods. However, this should have fossilized complete skeletons. Alternatively, herds of dinosaurs living in high latitudes might have been sexually driven to spend the half year of continuously illuminated polar summer for mating rather than for nourishment, in which the lower latitudes provided as well. The aggressive mating competitions would have left victims among the rivals and of young ones incidentally trampled over, all being consumed and their skeletons

  9. Optically polarized atoms understanding light-atom interactions

    CERN Document Server

    Auzinsh, Marcis; Rochester, Simon M

    2010-01-01

    This book is addressed at upper-level undergraduate and graduate students involved in research in atomic, molecular, and optical Physics. It will also be useful to researchers practising in this field. It gives an intuitive, yet sufficiently detailed and rigorous introduction to light-atom interactions with a particular emphasis on the symmetry aspects of the interaction, especially those associated with the angular momentum of atoms and light. The book will enable readers to carryout practical calculations on their own, and is richly illustrated with examples drawn from current research topic

  10. Extinction of polarized light in ferrofluids with different magnetic particle concentrations

    International Nuclear Information System (INIS)

    Socoliuc, V.; Popescu, L.B.

    2012-01-01

    The magnetic field intensity and nanoparticle concentration dependence of the polarized light extinction in a ferrofluid made of magnetite particles stabilized with technical grade oleic acid dispersed in transformer oil was experimentally investigated. The magnetically induced optical anisotropy, i.e. the dichroism divided by concentration, was found to decrease with increasing sample concentration from 2% to 8%. The magnetically induced change in the optical extinction of light polarized at 54.74 o with respect to the magnetic field direction was found to be positive for the less concentrated sample (2%) and negative for the samples with 4% and 8% magnetic nanoparticle concentrations, the more negative the higher the concentration and field intensity. Based on the theoretically proven fact that the particle orientation mechanism has no effect on the extinction of light polarized at 54.74 o with respect to the field direction, we analyzed the experimental findings in the frames of the agglomeration and long-range pair correlations theories for the magnetically induced optical anisotropy in ferrofluids. We developed a theoretical model in the approximation of single scattering for the optical extinction coefficient of a ferrofluid with magnetically induced particle agglomeration. The model predicts the existence of a polarization independent component of the optical extinction coefficient that is experimentally measurable at 54.74 o polarization angle. The change in the optical extinction of light polarized at 54.74 o is positive if only the formation of straight n-particle chains is considered and may become negative in the hypothesis that the longer chains degenerate to more isotropic structures (polymer-like coils, globules or bundles of chains). The model for the influence on the light absorption of the long-range pair correlations, published elsewhere, predicts that the change in the optical extinction of light polarized at 54.74 o is always negative, the more

  11. Optical asymmetric cryptography based on elliptical polarized light linear truncation and a numerical reconstruction technique.

    Science.gov (United States)

    Lin, Chao; Shen, Xueju; Wang, Zhisong; Zhao, Cheng

    2014-06-20

    We demonstrate a novel optical asymmetric cryptosystem based on the principle of elliptical polarized light linear truncation and a numerical reconstruction technique. The device of an array of linear polarizers is introduced to achieve linear truncation on the spatially resolved elliptical polarization distribution during image encryption. This encoding process can be characterized as confusion-based optical cryptography that involves no Fourier lens and diffusion operation. Based on the Jones matrix formalism, the intensity transmittance for this truncation is deduced to perform elliptical polarized light reconstruction based on two intensity measurements. Use of a quick response code makes the proposed cryptosystem practical, with versatile key sensitivity and fault tolerance. Both simulation and preliminary experimental results that support theoretical analysis are presented. An analysis of the resistance of the proposed method on a known public key attack is also provided.

  12. Polarization-sensitive optical frequency domain imaging based on unpolarized light.

    Science.gov (United States)

    Kim, Ki Hean; Park, B Hyle; Tu, Yupeng; Hasan, Tayyaba; Lee, Byunghak; Li, Jianan; de Boer, Johannes F

    2011-01-17

    Polarization-sensitive optical coherence tomography (PS-OCT) is an augmented form of OCT, providing 3D images of both tissue structure and polarization properties. We developed a new method of polarization-sensitive optical frequency domain imaging (PS-OFDI), which is based on a wavelength-swept source. In this method the sample was illuminated with unpolarized light, which was composed of two orthogonal polarization states (i.e., separated by 180° in the Poincaré sphere) that are uncorrelated to each other. Reflection of these polarization states from within the sample was detected simultaneously and independently using a frequency multiplexing scheme. This simultaneous sample probing with two polarization states enabled determination of the depth-resolved Jones matrices of the sample. Polarization properties of the sample were obtained by analyzing the sample Jones matrices through eigenvector decomposition. The new PS-OFDI system ran at 31K wavelength-scans/s with 3072 pixels per wavelength-scan, and was tested by imaging a polarizer and several birefringent tissues such as chicken muscle and human skin. Lastly the new PS-OFDI was applied to imaging two cancer animal models: a mouse model by injecting cancer cells and a hamster cheek pouch model. These animal model studies demonstrated the significant differences in tissue polarization properties between cancer and normal tissues in vivo.

  13. A dual-mode mobile phone microscope using the onboard camera flash and ambient light.

    Science.gov (United States)

    Orth, A; Wilson, E R; Thompson, J G; Gibson, B C

    2018-02-19

    Mobile phone microscopes are a natural platform for point-of-care imaging, but current solutions require an externally powered illumination source, thereby adding bulk and cost. We present a mobile phone microscope that uses the internal flash or sunlight as the illumination source, thereby reducing complexity whilst maintaining functionality and performance. The microscope is capable of both brightfield and darkfield imaging modes, enabling microscopic visualisation of samples ranging from plant to mammalian cells. We describe the microscope design principles, assembly process, and demonstrate its imaging capabilities through the visualisation of unlabelled cell nuclei to observing the motility of cattle sperm and zooplankton.

  14. Komar fluxes of circularly polarized light beams and cylindrical metrics

    Science.gov (United States)

    Lynden-Bell, D.; Bičák, J.

    2017-11-01

    The mass per unit length of a cylindrical system can be found from its external metric as can its angular momentum. Can the fluxes of energy, momentum, and angular momentum along the cylinder also be so found? We derive the metric of a beam of circularly polarized electromagnetic radiation from the Einstein-Maxwell equations. We show how the uniform plane wave solutions miss the angular momentum carried by the wave. We study the energy, momentum, angular momentum, and their fluxes along the cylinder both for this beam and in general. The three Killing vectors of any stationary cylindrical system give three Komar flux vectors which in turn give six conserved fluxes. We elucidate Komar's mysterious factor 2 by evaluating Komar integrals for systems that have no trace to their stress tensors. The Tolman-Komar formula gives twice the energy for such systems which also have twice the gravity. For other cylindrical systems their formula gives correct results.

  15. Reconfigurable terahertz grating with enhanced transmission of TE polarized light

    Directory of Open Access Journals (Sweden)

    J. W. He

    2017-07-01

    Full Text Available We demonstrate an optically reconfigurable grating with enhanced transmission of TE-polarized waves in the terahertz (THz waveband. This kind of grating is realized by projecting a grating image onto a thin Si wafer with a digital micromirror device (DMD. The enhanced transmission is caused by a resonance of the electromagnetic fields between the photoexcited strips. The position of the transmission peak shifts with the variation of the period and duty cycle of the photoinduced grating, which can be readily controlled by the DMD. Furthermore, a flattened Gaussian model was applied to describe the distribution of the photoexcited free carriers in the Si wafer, and the simulated transmittance spectra are shown to be in good agreement with the experimental results. In future, the photoexcited carriers could also be used to produce THz diffractive elements with reconfigurable functionality.

  16. Polarization resolved conoscopic patterns in nematic cells: effects induced by the incident light ellipticity

    Science.gov (United States)

    Buinyi, Igor O.; Soskin, Marat S.; Vovk, Roman G.

    2008-05-01

    Topological structure of the polarization resolved conoscopic patterns, calculated theoretically and measured experimentally for nematic liquid crystal (NLC) cells, is described in terms of polarization singularities, saddle points and bifurcation lines. The parametric dynamics of the topological network, induced by the variation of the incident light ellipticity, is analyzed for the nematic cells with uniform and non-uniform director configuration. Different stages of similar dynamics are observed for homeotropically oriented NLC cell. Non-uniform director configuration within the cell results in broken central symmentry in the arrangement of the topological network. Main features of the experimentally obtained polarization resolved conoscopic patterns are the same to the theoretically predicted ones.

  17. Injection and detection of a spin-polarized current in a light-emitting diode

    Science.gov (United States)

    Fiederling, R.; Keim, M.; Reuscher, G.; Ossau, W.; Schmidt, G.; Waag, A.; Molenkamp, L. W.

    1999-12-01

    The field of magnetoelectronics has been growing in practical importance in recent years. For example, devices that harness electronic spin-such as giant-magnetoresistive sensors and magnetoresistive memory cells-are now appearing on the market. In contrast, magnetoelectronic devices based on spin-polarized transport in semiconductors are at a much earlier stage of development, largely because of the lack of an efficient means of injecting spin-polarized charge. Much work has focused on the use of ferromagnetic metallic contacts, but it has proved exceedingly difficult to demonstrate polarized spin injection. More recently, two groups have reported successful spin injection from an NiFe contact, but the observed effects of the spin-polarized transport were quite small (resistance changes of less than 1%). Here we describe a different approach, in which the magnetic semiconductor BexMnyZn1-x-ySe is used as a spin aligner. We achieve injection efficiencies of 90% spin-polarized current into a non-magnetic semiconductor device. The device used in this case is a GaAs/AlGaAs light-emitting diode, and spin polarization is confirmed by the circular polarization state of the emitted light.

  18. POLARIZED LIGHT APPLICATION AT CHRONIC INSOMNIA AND HABIT OF SMOKING

    OpenAIRE

    D. Tubič; M. Skorbič

    2016-01-01

    In the treatment of patients with situational neurosis, which for years suffered from insomnia, we used a BIOPTRON-2 device. After 10 everyday evening sessions, the process of falling asleep was normalized, and night sleep was maintained with no additional drugs. A group of 30 patients with a chronic habit of intensive smoking was subjected to applications of BIOPTRON-2 generated PILER light for 10 days. In a considerable part of the tested persons, we noticed a decrease in the inclination fo...

  19. Sensing system with USB camera for experiments of polarization of the light

    Directory of Open Access Journals (Sweden)

    José Luís Fabris

    2017-08-01

    Full Text Available This work shows a sensor system for educational experiments, composed of a USB camera and a software developed and provided by the authors. The sensor system is suitable for the purpose of studying phenomena related to the polarization of the light. The system was tested in experiments performed to verify the Malus’ Law and the spectral efficiency of polarizers. Details of the experimental setup are shown. The camera captures the light in the visible spectral range from a LED that illuminates a white screen after passing through two polarizers. The software uses the image captured by the camera to provide the relative intensity of the light. With the use of two rotating H-sheet linear polarizers, a linear fitting of the Malus’s Law to the transmitted light intensity data resulted in correlation coefficients R larger than 0.9988. The efficiency of the polarizers in different visible spectral regions was verified with the aid of color filters added to the experimental setup. The system was also used to evaluate the intensity time stability of a white LED.

  20. Muscarinic cholinergic receptors subtypes in rat cerebellar cortex: light microscope autoradiography of age-related changes.

    Science.gov (United States)

    Tayebati, S K; Vitali, D; Scordella, S; Amenta, F

    2001-01-19

    Muscarinic cholinergic M1-M5 receptor subtypes were investigated in the cerebellar cortex of Fischer 344 rats aged 6 (young), 15 (adult) and 22 months (senescent) by combined kinetic and equilibrium binding and light microscope autoradiography. In young rats the rank order of receptor density was M5M4M4 in the molecular and granular layers, respectively. M1, M2, M4 and M5 receptors were also observed within Purkinje neurons. M1 receptor did not show age-related changes as well as the M2 receptor in the molecular layer. In this layer, M3-M5 receptors were increased in senescent compared to younger rats. In the granular layer the expression of M2 and M5 muscarinic receptors was similar in young and senescent rats and higher in adult rats. M3 and M4 receptors were more in adult and senescent rats compared to young animals. In Purkinje neurons, a slight-to-moderate age-related increase of M1 and M5 receptor expression was observed.

  1. Light and electron microscope observations on Nephroselmis gaoae sp. nov. (Prasinophyceae)

    Science.gov (United States)

    Tseng, C. K.; Jiao-Fen, Chen; Zhe-Fu, Zhang; Hui-Qi, Zhang

    1994-09-01

    Nephroselmis gaoae sp. nov. is described on the basis of light and electron microscope observations of cultured material originally collected and isolated from seawater of Jiaozhou Bay, Qingdao, China. The periplasts on the cell body and flagella are covered by five types of scales, two types on the flagella and three on the body. Among these, the morphology and the number of spines of large stellate body scales differ remarkably from those of previously described species of Nephroselmis. Apart from these, the unusual fine structure of the eyespot (stigma) is very characteristic. As in the other species of Nephroselmis, the eyespot lies immediately under the two-membraned chloroplast envelope; unlike the others, however, it is not composed of a number of osmiophilic globules, but consists of about 14 curved rod-shaped osmiophilic bodies arranged loosely and randomly. This feature distinguishes the present new species not only from the other species of Nephroselmis but also from the other motile algal species, the eyespots structure of which had been previously described.

  2. Demonstration of epidermal growth factor binding sites in the adult rat pancreas by light microscopic autoradiography

    International Nuclear Information System (INIS)

    Chabot, J.G.; Walker, P.; Pelletier, G.

    1987-01-01

    The distribution of epidermal growth factor (EGF) receptors was studied in the pancreas using light microscopic autoradiography, which was performed at different time intervals (2-60 min) after injecting 125 I-labeled EGF intravenously into the adult rat. In the exocrine pancreas, a labeling was found to occur over the pyramidal cells of the acini and cells lining the intercalated ducts. Moreover, substantial binding of EGF to cells of the islets of Langerhans was also revealed. At the 2-min time interval, most silver grains were found at the periphery of the target cells. The localization, as well as the diminution of silver grains over the cytoplasm of these cells, between 7 and 60 min, suggested the internalization and degradation of 125 I-labeled EGF. Control experiments indicated that the autoradiography reaction was due to specific interaction of 125 I-labeled EGF with its receptor. These results clearly indicate that EGF receptors are present in the acinar cells and the cells of intercalated ducts of the exocrine pancreas, as well as the cells of the endocrine pancreas. Finding that there are EGF binding sites in pancreatic acinar cells supports the physiological role of EGF in the regulation of pancreatic exocrine function. The presence of EGF receptors in cells of the islets of Langerhans suggests that EGF may play a role in the regulation of the endocrine pancreas

  3. Electric field Monte Carlo simulation of polarized light propagation in multi-layered media

    Science.gov (United States)

    Ding, Chizhu; Tan, Zuojun; Zhang, Shuhui; Chen, Siyu

    2017-10-01

    Electric field Monte Carlo (EMC) simulation is capable of modeling the polarization and coherence phenomena of light. Previous EMC program treat the turbid media as an infinite slab. An electric field Monte Carlo simulation of polarized light propagation in multi-layered media (EMCML) is presented in this paper. The complex electric field vectors are traced during the scattering and the reflection (or refraction) events. In order to improve the computational efficiency, our EMCML program is implemented in parallel in the GPU. The validity of EMCML is demonstrated by comparison between simulation results obtained by EMCML and previously reported programs.

  4. Gross and microscopic findings in patients submitted to nonablative full-face resurfacing using intense pulsed light: a preliminary study.

    Science.gov (United States)

    Hernández-Pérez, Enrique; Ibiett, Erick Valencia

    2002-08-01

    Intense pulsed light (IPL) is a noncoherent, nonlaser, filtered flashlamp emitting a broadband visible light that has been shown to be effective in photoepilation, as well as in a number of vascular and pigmented lesions of the skin. Their efficacy has also been reported recently in the treatment of photodamaged facial skin. In the last condition, however, there are few studies showing the clinical and microscopic changes produced by IPL. To assess the gross and microscopic changes that occur in photodamaged skin submitted to nonablative full-face resurfacing (NAFFR) using IPL. Five women were submitted to five NAFFR sessions using IPL, one every 2 weeks. Skin biopsies and photographs were taken on all of the patients before the first procedure and after the last one, as well as weekly clinical assessment. Data concerning skin features (wrinkles, oiliness, thickness, dilated pores, and general appearance) were all assessed. Microscopic improvement of the aging features in the epidermis and dermis were all assessed. For the statistical analysis a t test for small samples was used. All the patients showed clinical and microscopic improvement in every one of the parameters assessed. The t test for small samples showed a statistically significant difference (P Facial photodamage was clinically and microscopically improved using IPL. Use of IPL as a rejuvenating method seems to be promising, with minimal side effects, a wide safety margin, and minimal downtime.

  5. Candidate magnetic dust structures for star light polarization

    Science.gov (United States)

    Papoular, R.

    2017-11-01

    Rotation damping and alignment are discussed as prerequisites for polarization. An expression is derived from first principles, for the damping time of the rotation of a particle in a magnetic field, under the Faraday braking torque, provided its electrical properties are known. This makes it possible to describe mathematically, in great detail, the motion of the particle and determine its ultimate state of motion, if a steady state is possible at all. This work defines, first, the necessary condition for the Faraday braking to be effective: (a) the net electronic charge distribution should not be uniform throughout and (b) the number of vibration modes should exceed a few tens. Resonance of rotation frequency with any of these modes is not a requirement. For alignment to be possible, the ratio of gyroscopic and conservative magnetic to non-conservative (retarding) magnetic torques must be low. Either dia-, para- or ferromagnetism can do, and a small susceptibility is enough and even preferable. This opens up a wide spectrum of possible candidates. A few examples are given.

  6. Polarization independent asymmetric light absorption in plasmonic nanostructure

    Science.gov (United States)

    Franco Rêgo, Davi; Rodriguez-Esquerre, Vitaly Felix

    2017-08-01

    The directional dependency of the optical coefficients, such as absorbance and reflectance, of a periodic hole plasmonic structure is numerically simulated and investigated. The tridimensional structure, which is composed of a metallic thin layer on a semiconductor matrix, is polarization independent and exhibits wide angle tolerance. It is found that the optical coefficients of the simulated structure have strong dependency to the radii of the holes due to cavity modes resonance and surface plasmon resonance. Simulations were carried out using gold and silver, varying the holes radii ranging from 40 to 70nm, as well as its depth, from 30 to 60nm of the metallic thin layer and from 100 to 200nm of the semiconductor matrix. A maximum contrast ratio of a unit was obtained. The resonant modes excited in the structure and excitation of surface plasmon polaritons in the metallic side illumination favors absorption, which explains the asymmetric behavior. We also investigate the structure's fabrication sensitivity by randomizing the generation of center of the holes in a supercell. These findings are significant for a diverse range of applications, ranging from optical integrated circuits to solar and thermovoltaics energy harvesting.

  7. Commissioning and modification of the low temperature scanning polarization microscope (TTSPM) and imaging of the local magnetic flux density distribution in superconducting niobium samples

    International Nuclear Information System (INIS)

    Gruenzweig, Matthias Sebastian Peter

    2014-01-01

    The dissertation is separated into two different parts, which will be presented in the following. Part I of the dissertation is about the commissioning and the modification of the ''low-temperature scanning polarization microscope'' which was designed in a previous dissertation of Stefan Guenon [1]. A scanning polarization microscope has certain advantages compared to conventional polarization microscopes. With a scanning polarization microscope it is easily possible to achieve a high illumination intensity, which is important to realize a high signal-to-noise ratio. Moreover, the confocal design of the scanning polarization microscope improves the resolution of the microscope by a factor of 1.4. Normally, it is not necessary to post-process the images by means of differential frame method to eliminate the contrast of non-magnetic origin. In contrast to conventional polarization microscopes the low-temperature scanning polarization microscope is able to image electronic transport properties via beam-induced voltage variation in addition to the magneto-optical effects. In this dissertation, it was possible to demonstrate the performance capability of the scanning polarization microscope at room temperature as well as at low temperatures. The investigation of the polar Kerr-effect has been carried out with a BaFe 12 O 19 -test sample whereas the measurements of the longitudinal Kerr-effect have been carried out with an in-plane magnetized acceleration sensor. Furthermore, an independent room temperature construction for out-of-plane measurements in a magnetic field up to 1 Tesla has been designed and implemented within the framework of a diploma thesis, supervised by the author of this dissertation. Using this construction, it was possible to gain experimental results regarding the interlayer exchange coupling between iron-terbium alloys (Fe 1-x Tb x ) and cobalt-platinum multilayers (vertical stroke Co/Pt vertical stroke n ). Indeed, it has been

  8. POLARIZED LIGHT APPLICATION AT CHRONIC INSOMNIA AND HABIT OF SMOKING

    Directory of Open Access Journals (Sweden)

    D. Tubič

    2016-06-01

    Full Text Available In the treatment of patients with situational neurosis, which for years suffered from insomnia, we used a BIOPTRON-2 device. After 10 everyday evening sessions, the process of falling asleep was normalized, and night sleep was maintained with no additional drugs. A group of 30 patients with a chronic habit of intensive smoking was subjected to applications of BIOPTRON-2 generated PILER light for 10 days. In a considerable part of the tested persons, we noticed a decrease in the inclination for smoking and an increase in the wish for final putting an end to smoke.

  9. Self-Induced Light Polarization Rotation in Azobenzene-Containing Polymers

    DEFF Research Database (Denmark)

    Nikolova, L.; Nedelchev, L.; Todorov, T.

    2000-01-01

    We report here a light-induced phenomenon--a self-induced rotation of the azimuth of elliptically polarized light passing through photobirefringent azopolymers. The experiments are carried out with films of amorphous and liquid-crystalline polymers. It has been shown that the induced rotation angle...... depends on the ellipticity of the input light. A theoretical analysis of the phenomenon has been done and it has been shown that light induces chiral structure in the polymer films. (C) 2000 American Institute of Physics. [S0003-6951(00)02731-5]....

  10. Gamma-Ray Pulsar Light Curves in Offset Polar Cap Geometry

    Science.gov (United States)

    Harding, Alice K.; DeCesar, Megan; Miller, M. Coleman

    2011-01-01

    Recent studies have shown that gamma-ray pulsar light curves are very sensitive to the geometry of the pulsar magnetic field. Pulsar magnetic field geometries, such as the retarded vacuum dipole and force-free magnetospheres, used to model high-energy light curves have distorted polar caps that are offset from the magnetic axis in the direction opposite to rotation. Since this effect is due to the sweepback of field lines near the light cylinder, offset polar caps are a generic property of pulsar magnetospheres and their effects should be included in gamma-ray pulsar light curve modeling. In slot gap models (having two-pole caustic geometry), the offset polar caps cause a strong azimuthal asymmetry of the particle acceleration around the magnetic axis. We have studied the effect of the offset polar caps in both retarded vacuum dipole and force-free geometry on the model high-energy pulse profile. We find that. corn pared to the profile:-; derived from :-;ymmetric caps, the flux in the pulse peaks, which are caustics formed along the trailing magnetic field lines. increases significantly relative to the off-peak emission. formed along leading field lines. The enhanced contrast produces greatly improved slot gap model fits to Fermi pulsar light curves like Vela, which show very little off-peak emIssIon.

  11. [The evaluation of acrylic resins for the study of nondecalcified human teeth with the light and electronic microscopes].

    Science.gov (United States)

    Botti, F; Martignoni, M; Scala, C; Cocchia, D

    1995-04-01

    Resin embedding of human teeth for light and transmission electron microscopic studies becomes difficult without previous decalcification. The limited and slow infiltration of the resin into hard tissues may cause problems during preparation and observation of the samples. Moreover the type of resin that is used may affect the morphologic preservation of both tissues and cellular elements. Recently there has been an increasing number of studies on the application of acrylic resins in light and electron microscopy, in order to overcome problems encountered with the use of epoxy resins still utilized in morphologic studies. We compared different acrylic resins (Technovit 7200 VLC, LR White, LR Gold, Bioacryl) in order to understand which one was more suitable for undecalcified human dental tissues under light and transmission electron microscope. Evaluation of such resins was performed using the following criteria: ease of cutting with ultramicrotome, soft and hard tissues infiltration, uptake of tissue stains for both light and electron microscopy, morphologic preservation and stability under electron beam. This study, carried out on the pulp area comprising predentin and dentin, showed excellent quality of Bioacryl and LR Gold, the two resins presenting, by far, the best results among all the different types tested. The optimal morphologic preservation obtained with such resins is indicated for light and electron microscopic studies, allowing their application in different fields of dental research.

  12. Vector Sky Glint Corrections for Above Surface Retrieval of the Subsurface Polarized Light Field

    Science.gov (United States)

    Gilerson, A.; Foster, R.; McGilloway, A.; Ibrahim, A.; El-habashi, A.; Carrizo, C.; Ahmed, S.

    2016-02-01

    Knowledge of the underwater light field is fundamental to determining the health of the world's oceans and coastal regions. For decades, traditional remote sensing retrieval methods that rely solely on the spectral intensity of the water-leaving light have provided indicators of marine ecosystem health. As the demand for retrieval accuracy rises, use of the polarized nature of light as an additional remote sensing tool is becoming necessary. In order to observe the underwater polarized light field from above the surface (for ship, shore, or satellite applications), a method of correcting the above water signal for the effects of polarized surface-reflected skylight is needed. For three weeks in July-August 2014, the NASA Ship Aircraft Bio-Optical Research (SABOR) cruise continuously observed the polarized radiance of the ocean and the sky using a HyperSAS-POL system. The system autonomously tracks the Sun position and the heading of the research vessel in order to maintain a fixed relative solar azimuth angle (i.e. ±90°) and therefore avoid the specular reflection of the sunlight. Additionally, in-situ inherent optical properties (IOPs) were continuously acquired using a set of instrument packages modified for underway measurement, hyperspectral radiometric measurements were taken manually at all stations, and an underwater polarimeter was deployed when conditions permitted. All measurements, above and below the sea surface, were combined and compared in an effort to first develop a glint (sky + Sun) correction scheme for the upwelling polarized signal from a wind-driven ocean surface and compare with one assuming that the ocean surface is flat. Accurate retrieval of the subsurface vector light field is demonstrated through comparisons with polarized radiative transfer codes and direct measurements made by the underwater polarimeter.

  13. Impact of spin-zero particle-photon interactions on light polarization in external magnetic fields

    International Nuclear Information System (INIS)

    Liao Yi

    2007-01-01

    If the recent PVLAS results on polarization changes of a linearly polarized laser beam passing through a magnetic field are interpreted by an axion-like particle, it is almost certain that it is not a standard QCD axion. Considering this, we study the general effective interactions of photons with spin-zero particles without restricting the latter to be a pseudo-scalar or a scalar, i.e., a parity eigenstate. At the lowest order in effective field theory, there are two dimension-5 interactions, each of which has previously been treated separately for a pseudo-scalar or a scalar particle. By following the evolution in an external magnetic field of the system of spin-zero particles and photons, we compute the changes in light polarization and the transition probability for two experimental set-ups: one-way propagation and round-trip propagation. While the first may be relevant for astrophysical sources of spin-zero particles, the second applies to laboratory optical experiments like PVLAS. In the one-way propagation, interesting phenomena can occur for special configurations of polarization where, for instance, transition occurs but light polarization does not change. For the round-trip propagation, however, the standard results of polarization changes for a pseudoscalar or a scalar are only modified by a factor that depends on the relative strength of the two interactions

  14. Nonlinear optical responses to circularly polarized lights of the surface state of a topological insulator

    Science.gov (United States)

    Misawa, Tetsuro; Yokoyama, Takehito; Murakami, Shuichi

    2012-02-01

    Recent photoelectron spectroscopy experiments have revealed the presence of the Dirac cone on the surface of the topological insulator and its spin-splitting due to the spin-orbit interaction. In general, on spin-orbit coupled systems, electric fields induce spin polarizations as linear and nonlinear responses. Here we investigate the inverse Faraday effect on the surface of the topological insulator. The inverse Faraday effect is a non-linear optical effect where a circularly polarized light induces a dc spin polarization. We employ the Keldysh Green's function method to calculate the induced spin polarization and discuss its frequency dependence. In particular, in the low frequency limit, our analytical result gives the spin polarization proportional to the frequency and the square of the lifetime. As for the finite frequency regime, we employ numerical methods to discuss the resonance due to interband transitions. We also discuss the photogalvanic effect, where an illumination of a circular polarized light generates the dc charge current. Lastly, we evaluate those quantities with realistic parameters.[4pt] [1] T. Misawa, T. Yokoyama, S. Murakami, Phys. Rev. B84, 165407 (2011).

  15. New shapes of light-cone distributions of the transversely polarized ρ-mesons

    International Nuclear Information System (INIS)

    Bakulev, A.P.; Mikhajlov, S.V.

    2000-01-01

    The leading twist light-cone distributions for transversely polarized ρ-, ρ ' - and b 1 mesons are reanalyzed in the framework of QCD sum rules with nonlocal condensates. Using different kinds of sum rules to obtain reliable predictions, we estimate the 2-, 4-, 6- and 8-th moments for transversely polarized ρ- and ρ ' -meson distributions and reestimate tensor couplings f ρ,ρ ' ,b 1 T . It is stressed that the results of standard sum rules also support our estimation of the second moment of the transversely polarized ρ-meson distribution. New models for light-cone distributions are briefly discussed. Our results are compared with those found by Ball and Braun (1996), and the latter is shown to be incomplete

  16. A portable liquid crystal-based polarized light system for the detection of organophosphorus nerve gas

    Science.gov (United States)

    He, Feng Jie; Liu, Hui Long; Chen, Long Cong; Xiong, Xing Liang

    2018-03-01

    Liquid crystal (LC)-based sensors have the advantageous properties of being fast, sensitive, and label-free, the results of which can be accessed directly only through the naked eye. However, the inherent disadvantages possessed by LC sensors, such as relying heavily on polarizing microscopes and the difficulty to quantify, have limited the possibility of field applications. Herein, we have addressed these issues by constructing a portable polarized detection system with constant temperature control. This system is mainly composed of four parts: the LC cell, the optics unit, the automatic temperature control unit, and the image processing unit. The LC cell was based on the ordering transitions of LCs in the presence of analytes. The optics unit based on the imaging principle of LCs was designed to substitute the polarizing microscope for the real-time observation. The image processing unit is expected to quantify the concentration of analytes. The results have shown that the presented system can detect dimethyl methyl phosphonate (a stimulant for organophosphorus nerve gas) within 25 s, and the limit of detection is about 10 ppb. In all, our portable system has potential in field applications.

  17. Multiple scattering of polarized light in birefringent slab media: experimental verifications and simulations.

    Science.gov (United States)

    Otsuki, Soichi

    2018-02-01

    The effective scattering Mueller matrices were measured for backward and forward scattering by applying a narrow polarized light on a polyacrylamide slab gel, which was strained vertically to generate birefringence inside. Monte Carlo simulations were performed in conditions that were the same as possible. The measured and simulated matrices were simplified to the reduced ones. They agreed well in both original and reduced forms. While they approximately take reciprocal forms for backward scattering, they approximately satisfy matrix forms that correspond to a reciprocal position of the mirror image for forward scattering. The reduced matrices were factorized by the Lu-Chipman polar decomposition to obtain the polarization parameters. The polarization parameters were in good agreement between the measurement and simulation and showed characteristic features of anisotropic slab media with a birefringence axis parallel to the slab surface.

  18. Hyalocytes in idiopathic epiretinal membranes: a correlative light and electron microscopic study.

    Science.gov (United States)

    Schumann, Ricarda G; Gandorfer, Arnd; Ziada, Jean; Scheler, Renate; Schaumberger, Markus M; Wolf, Armin; Kampik, Anselm; Haritoglou, Christos

    2014-12-01

    To describe characteristics of epiretinal cells at the vitreoretinal interface by correlative light and electron microscopy (CLEM). Epiretinal membrane (ERM) specimens and internal limiting membrane (ILM) specimens were harvested by sequential peeling during vitrectomy from 27 eyes with idiopathic epiretinal gliosis, and processed for CLEM. Intraoperatively, the presence of posterior vitreous detachment (PVD) was documented. We used anti-vimentin, anti-α-smooth muscle actin (α-SMA), and anti-CD45 as primary antibodies. A fluorescein-tagged immunonanogold cluster was used as secondary antibody and visualized under the fluorescence and transmission electron microscope. We demonstrated CD45-positive cells specifically labelled at their plasma membranes with ultrastructural features known for hyalocytes, such as oval nucleus with marginal chromatin, vacuoles, dense granules, and thin cytoplasmic protrusions. CD45-positive cells were mostly located on a thick layer of native vitreous collagen. They were covered by newly formed collagen strands with multilayered proliferation of myofibroblasts. We also demonstrated immunoreactivity for vimentin and alpha-SMA. Cell fragments with positive labelling for α-SMA and vimentin were not only found on the vitreal side of the ILM, but also on the retinal side. By CLEM, the majority of CD45-positive cells in epiretinal cell proliferation were characterized as hyalocytes. In the context of anomalous PVD and vitreoschisis, ultrastructural features and topographic localization of hyalocytes suggest that these cells play a significant role in ERM formation. CLEM enables a more accurate characterization of epiretinal cell proliferation, and therefore, contributes to a better understanding of the pathogenesis of diseases at the vitreoretinal interface.

  19. Histological changes in kidneys of adult rats treated with Monosodium glutamate: A light microscopic study

    Directory of Open Access Journals (Sweden)

    Singh BR, Ujwal Gajbe, Anil Kumar Reddy, Vandana Kumbhare

    2015-01-01

    Full Text Available Introduction: Monosodium Glutamate (MSG, which is chemically known as AJI-NO-MOTO also familiar as MSG in routine life. MSG is always considered to be a controversial food additive used in the world. It is a natural excitatory neurotransmitter, helps in transmitting the fast synaptic signals in one third of CNS. Liver and kidney play a crucial role in metabolism as well as elimination of MSG from the body. Present study is to detect structural changes in adult rat kidney tissue treated with MSG; observations are done with a light microscope. Materials & Methods: The study was conducted in the department of Anatomy, J.N.M.C, Sawangi (M Wardha. Thirty (30 adult Wistar rats (2-3 months old weighing about (200 ± 20g were used in the current study, animals were divided into three groups (Group – A, B, C. Group A: Control, Group B: 3 mg /gm body weight, Group C: 6 mg /gm body weight, MSG were administered orally daily for 45 days along with the regular diet. Observations & Results: The Mean values of animals weight at the end of experiment (46th day respectively were 251.2 ± 13, 244.4 ± 19.9 and 320 ± 31.1. Early degenerative changes like, Glomerular shrinkage (GSr, loss of brush border in proximal convoluted tubules and Cloudy degeneration was observed in sections of kidney treated with 3 mg/gm body weight of MSG. Animals treated with 6 mg/gm body weight of MSG showed rare changes like interstitial chronic inflammatory infiltrate with vacuolation in some of the glomeruli, and much glomerular shrinkage invaginated by fatty lobules. Conclusion: The effects of MSG on kidney tissues of adult rats revealed that the revelatory changes are directly proportional to the doses of MSG.

  20. [Particle Size and Number Density Online Analysis for Particle Suspension with Polarization-Differentiation Elastic Light Scattering Spectroscopy].

    Science.gov (United States)

    Chen, Wei-kang; Fang, Hui

    2016-03-01

    The basic principle of polarization-differentiation elastic light scattering spectroscopy based techniques is that under the linear polarized light incidence, the singlely scattered light from the superficial biological tissue and diffusively scattered light from the deep tissue can be separated according to the difference of polarization characteristics. The novel point of the paper is to apply this method to the detection of particle suspension and, to realize the simultaneous measurement of its particle size and number density in its natural status. We design and build a coaxial cage optical system, and measure the backscatter signal at a specified angle from a polystyrene microsphere suspension. By controlling the polarization direction of incident light with a linear polarizer and adjusting the polarization direction of collected light with another linear polarizer, we obtain the parallel polarized elastic light scattering spectrum and cross polarized elastic light scattering spectrum. The difference between the two is the differential polarized elastic light scattering spectrum which include only the single scattering information of the particles. We thus compare this spectrum to the Mie scattering calculation and extract the particle size. We then also analyze the cross polarized elastic light scattering spectrum by applying the particle size already extracted. The analysis is based on the approximate expressions taking account of light diffusing, from which we are able to obtain the number density of the particle suspension. We compare our experimental outcomes with the manufacturer-provided values and further analyze the influence of the particle diameter standard deviation on the number density extraction, by which we finally verify the experimental method. The potential applications of the method include the on-line particle quality monitoring for particle manufacture as well as the fat and protein density detection of milk products.

  1. Assessment Of Mold-Design Dependent Textures In CIM-Components By Polarized Light Optical Texture Analysis (PLOTA)

    International Nuclear Information System (INIS)

    Kern, Frank; Rauch, Johannes; Gadow, Rainer

    2007-01-01

    By thermoplastic ceramic injection moulding (CIM) ceramic components of high complexity can be produced in a large number of items at low dimensional tolerances. The cost advantage by the high degree of automation leads to an economical mass-production. The structure of injection-moulded components is determined by the form filling behaviour and viscosity of the feedstock, the machine parameters, the design of the mold and the gate design. With an adapted mold- and gate-design CIM-components without textures are possible. The ''Polarized Light Optical Texture analysis'' (PLOTA) makes it possible to inspect the components and detect and quantify the textures produced by a new mold. Based on the work of R. Fischer (2004) the PLOTA procedure was improved by including the possibility to measure the inclination angle and thus describe the orientation of the grains in three dimensions. Sampled thin sections of ceramic components are analysed under the polarization microscope and are brought in diagonal position. Pictures are taken with a digital camera. The pictures are converted in the L*a*b*- colour space and the crystals color values a* and b* in the picture are measured. The color values are compared with the values of a quartz wedge, which serves as universal standard. From the received values the inclination angle can be calculated relative to the microscope axis. It is possible to use the received data quantitatively e.g. for the FEM supported simulation of texture-conditioned divergences of mechanical values. Thus the injection molding parameters can be optimized to obtain improved mechanical properties

  2. Treatment of carpal tunnel syndrome with polarized polychromatic noncoherent light (Bioptron light): a preliminary, prospective, open clinical trial.

    Science.gov (United States)

    Stasinopoulos, D; Stasinopoulos, I; Johnson, M I

    2005-04-01

    Our aim was to assess the efficacy of polarized polychromatic noncoherent light (Bioptron light) in the treatment of idiopathic carpal tunnel syndrome. Carpal tunnel syndrome is the most common compression neuropathy, but no satisfactory conservative treatment is available at present. An uncontrolled experimental study was conducted in patients who visited our clinic from mid-2001 to mid-2002. A total of 25 patients (22 women and three men) with unilateral idiopathic carpal tunnel syndrome, mild to moderate nocturnal pain, and paraesthesia lasting >3 months participated in the study. The average age of the patients was 47.4 years and the average duration of patients' symptoms was 5.2 months. Polarized polychromatic noncoherent light (Bioptron light) was administered perpendicular to the carpal tunnel area. The irradiation time for each session was 6 min at an operating distance of 5-10 cm from the carpal tunnel area, three times weekly for 4 weeks. Outcome measures used were the participants' global assessments of nocturnal pain and paraesthesia, respectively, at 4 weeks and 6 months. At 4 weeks, two patients (8%) had no change in nocturnal pain, six (24%) were in slightly less nocturnal pain, 12 (48%) were much better in regard to nocturnal pain and five (20%) were pain-free. At 6 months, three patients (12%) were slightly better in regard to nocturnal pain, 13 (52%) were much better regarding nocturnal pain, and nine patients (36%) were pain-free. At 4 weeks, four patients (16%) had no change in paraesthesia, five (20%) were slightly better, 13 patients (52%) were much better, and three patients (12%) were without paraesthesia. At 6 months, two patients (8%) had no change in paraesthesia, two (8%) were slightly better, 14 (56%) were much better, and seven (28%) were without paraesthesia. Nocturnal pain and paraesthesia associated with idiopathic carpal tunnel syndrome improved during polarized polychromatic noncoherent light (Bioptron light) treatment. Controlled

  3. arXiv Black hole superradiance and polarization-dependent bending of light

    CERN Document Server

    Plascencia, Alexis D.

    2017-01-01

    An inhomogeneous pseudo-scalar field configuration behaves like an optically active medium. Consequently, if a light ray passes through an axion cloud surrounding a Kerr black hole, it may experience a polarization-dependent bending. We explore the size and relevance of such effect considering both the QCD axion and a generic axion-like particle.

  4. Intensity-dependent change in polarization state of light in normal ...

    Indian Academy of Sciences (India)

    Intensity-dependent change in polarization state of light in normal incidence on an isotropic nonlinear Kerr medium. Hari Prakash Devendra K ... Devendra K Singh2. Department of Physics, University of Allahabad, Allahabad 211 002, India; Department of Physics, Udai Pratap Autonomous College, Varanasi 221 002, India ...

  5. Contribution of spontaneous polarization and its fluctuations to refraction of light in ferroelectrics

    Czech Academy of Sciences Publication Activity Database

    Markovin, P.A.; Trepakov, Vladimír; Tagantsev, A. K.; Dejneka, Alexandr; Andreev, D. A.

    2016-01-01

    Roč. 58, č. 1 (2016), 134-139 ISSN 1063-7834 R&D Projects: GA ČR GA15-13778S Institutional support: RVO:68378271 Keywords : contribution * spontaneous polarization * fluctuations * refraction * light * ferroelectrics Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 0.860, year: 2016

  6. Myth polar light. Why sky bands, herring lightnings, and solar winds fascinate; Mythos Polarlicht. Warum Himmelsbaender, Heringsblitze und Sonnenwinde faszinieren

    Energy Technology Data Exchange (ETDEWEB)

    Hunnekuhl, Michael

    2014-07-01

    The actual state of knowledge of the polar-light research is in this illustrated volume as entertainingly as scientific-foundedly presented. The pecularities of pola lights beyond the polar-light zones as for instance in Germany are thematized and the conditions and periods, in which it there occurs, explained. Michael Hunnekuhl succeeds to mediate the fascination and emotion and simultaneously to explain the phenomena according to the latest state of science generally understandably. Which very old interpretations and descriptions are transmitted, which imaginations had men of polar lights long before the science could them explain? Hunnekuhl takes the reader along with into the world of legends and myths around the polar light. An experience report from the deeply snowed up wideness of Lapland lets everybody closely participate at a polar-light observation and feel the emotion, which it can fan. Above 70 polar-light pictures of high value and further explaining graphics show the continuously changing play of colors, supplement the explanations, and make the fascination comprehensible. Spectacular polar-light films from the international space station ISS, photographs from sun-observation satellites, as well as a polar-light film in real time are bound in the book via QR codes and make the time dimension and the dynamics of this fascinating natural spectacle alively comprehensible.

  7. Analytic parallel-polarized light imaging technique using various light-emitting diodes: a comparison with skin conductance values.

    Science.gov (United States)

    Kim, D H; Choi, J E; Ryu, H J; Seo, S H; Kye, Y C; Ahn, H H

    2015-05-01

    The quantitative difference of the light reflected from a skin surface can be analyzed using parallel-polarized light (PPL) photography when combined with an analytic technique similar to colorimetric photography. To improve the PPL photography technique as an assessment tool for the evaluation of skin condition using light-emitting diodes (LED) of different colors. Parallel-polarized light images were taken using white and green LED illuminators. The acquired images were transformed to CIELAB coordinates. An in-house skin conductance meter was constructed to assess skin hydration level. A dermatologist evaluated the clinical grading of dryness and glossiness. These clinical severities were also compared statistically with the CIELAB values. As with the green illuminator, the correlation analysis of whole sites showed that the L* value positively correlated with age (r = 0.18677, P < 0.05), and that the a* value has negative and positive relationships with age (r = -0.20528, P < 0.05) and glossiness (r = 0.20885, P < 0.05) respectively. The correlations between CIELAB values and multiple characteristics of skin were more significant when green LED was applied than when white light was applied. In addition, coherent relationships between the grade of dryness and skin conductance values showed that visual assessment could be appropriate for the study as with objective measurement. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  8. Polarized light field microscopy: an analytical method using a microlens array to simultaneously capture both conoscopic and orthoscopic views of birefringent objects.

    Science.gov (United States)

    Oldenbourg, R

    2008-09-01

    For the comprehensive analysis of anisotropic materials, a new approach, called 'polarized light field microscopy' is introduced. It uses an LC-PolScope to which a microlens array was added at the image plane of the objective lens. The system is patterned after the 'light field microscope' that achieves both lateral and axial resolution in thick specimens in a single camera exposure. In polarized light field microscopy, the microlens array generates a hybrid image consisting of an array of small conoscopic images, each sampling a different object area. Analysis of the conoscopic images reveals the birefringence of each object area as a function of the propagation direction of transmitted light rays. The principles and utility of the instrument that we are calling 'light field LC-PolScope' are demonstrated with images of a thin, polycrystalline calcite film, revealing the azimuth and inclination angle of the optic axis for many crystals simultaneously, including crystals with diameters as small as 2 microm. Compared to traditional conoscopy and related methods, the vastly improved throughput and quantitative analysis afforded by the light field LC-PolScope make it the instrument of choice for measuring 3D birefringence parameters of complex structures.

  9. Induction of transverse polarity by blue light: an all-or-none response.

    Science.gov (United States)

    Nick, P; Schafer, E

    1991-10-01

    Phototropic stimulation induces a spatial memory. This was inferred from experiments with maize (Zea mays L.) coleoptiles involving opposing blue-light pulses, separated by variable time intervals, and rotation on a horizontal clinostat (Nick and Schafer, 1988b, Planta 175, 380-388). In those experiments, individual seedlings either curved towards the first or towards the second pulse, or they remained straight. Bending, if it occurred, seemed to be an all-or-none response. Intermediates, i.e. plants, bending only weakly, were not observed. In the first part of the present study it was attempted to create such intermediates. For this purpose the strength of the first, inducing, and the second, opposing, pulse was varied. The result was complex: (i) Individual seedlings maintained the all-or-none expression of spatial memory. (ii) However, on the level of the whole population, the time intervals at which a given response type dominated depended on the fluence ratio. (iii) Furthermore, the final curvature was determined by the fluence ratio. These results are discussed in terms of a blue-light-induced transverse polarity. This polarity initiates from a labile precursor, which can be reoriented by an opposing stimulation (indicated by the strong bending towards the second pulse). The strong curvatures towards the first pulse over long time intervals reveal that, eventually, the blue-light-induced transverse polarity becomes stabilised and thus immune to the counterpulse. In the second part of the study, the relation between phototropic transduction and transverse polarity was characterised by a phenomenological approach involving the following points: (i) Sensory adaptation for induction of transverse polarity disappears with a time course similar to that for phototropic sensory adaptatation. (ii) The fluence response for induction of transverse polarity is a saturation curve and not bell-shaped like the curve for phototropism (iii) For strong counterpulses and long

  10. Polarization-independent asymmetric light transmission in all-dielectric photonic structures

    Science.gov (United States)

    Zinkiewicz, Lukasz; Nawrot, Michal; Haberko, Jakub; Wasylczyk, Piotr

    2017-11-01

    We design, optimize and fabricate an all-dielectric photonic structure, having a significant, polarization-independent asymmetry in light transmission for opposite incident wave directions. The device, consisting of a dielectric Bragg mirror topped with a regular grid of micrometer-sized pillars, acting as a diffraction grating, is potentially scalable into industrial production. The light propagation simulation results are confirmed by direct measurement of the difference in light transmission, reaching 0.55 near 780 nm, and exceeding 0.2 over a spectral range spanning from 750 to 820 nm.

  11. Lateral refraction and reflection of light polarized lenses principle. Coplanar lens systems

    International Nuclear Information System (INIS)

    Miranda, L.

    2012-01-01

    Studying the behavior of the linearly polarized light to impact a lens and in the lens itself, resulted in the discovery of a physical principle of optics, not mentioned or used so far. This phenomenon is very useful in practice. Perhaps the manifestation of the phenomenon occurs in the plane perpendicular to the road or optical axis, is due the reason that was not seen before, but it has always been there when polarized light passes through a lens. Known and mastered the principle has been manipulated for better research results, using for the first time a planar lens system, which according to the placement of the lens allows for accurate lags between the light beams ar the exits the system. (Author)

  12. Compact, light-weight and cost-effective microscope based on lensless incoherent holography for telemedicine applications.

    Science.gov (United States)

    Mudanyali, Onur; Tseng, Derek; Oh, Chulwoo; Isikman, Serhan O; Sencan, Ikbal; Bishara, Waheb; Oztoprak, Cetin; Seo, Sungkyu; Khademhosseini, Bahar; Ozcan, Aydogan

    2010-06-07

    Despite the rapid progress in optical imaging, most of the advanced microscopy modalities still require complex and costly set-ups that unfortunately limit their use beyond well equipped laboratories. In the meantime, microscopy in resource-limited settings has requirements significantly different from those encountered in advanced laboratories, and such imaging devices should be cost-effective, compact, light-weight and appropriately accurate and simple to be usable by minimally trained personnel. Furthermore, these portable microscopes should ideally be digitally integrated as part of a telemedicine network that connects various mobile health-care providers to a central laboratory or hospital. Toward this end, here we demonstrate a lensless on-chip microscope weighing approximately 46 grams with dimensions smaller than 4.2 cm x 4.2 cm x 5.8 cm that achieves sub-cellular resolution over a large field of view of approximately 24 mm(2). This compact and light-weight microscope is based on digital in-line holography and does not need any lenses, bulky optical/mechanical components or coherent sources such as lasers. Instead, it utilizes a simple light-emitting-diode (LED) and a compact opto-electronic sensor-array to record lensless holograms of the objects, which then permits rapid digital reconstruction of regular transmission or differential interference contrast (DIC) images of the objects. Because this lensless incoherent holographic microscope has orders-of-magnitude improved light collection efficiency and is very robust to mechanical misalignments it may offer a cost-effective tool especially for telemedicine applications involving various global health problems in resource limited settings.

  13. Compact, Light-weight and Cost-effective Microscope based on Lensless Incoherent Holography for Telemedicine Applications

    Science.gov (United States)

    Mudanyali, Onur; Tseng, Derek; Oh, Chulwoo; Isikman, Serhan O.; Sencan, Ikbal; Bishara, Waheb; Oztoprak, Cetin; Seo, Sungkyu; Khademhosseini, Bahar; Ozcan, Aydogan

    2010-01-01

    Despite the rapid progress in optical imaging, most of the advanced microscopy modalities still require complex and costly set-ups that unfortunately limit their use beyond well equipped laboratories. In the meantime, microscopy in resource-limited settings has requirements significantly different from those encountered in advanced laboratories, and such imaging devices should be cost-effective, compact, light-weight and appropriately accurate and simple to be usable by minimally trained personnel. Furthermore, these portable microscopes should ideally be digitally integrated as part of a telemedicine network that connects various mobile health-care providers to a central laboratory or hospital. Toward this end, here we demonstrate a lensless on-chip microscope weighing ~46 grams with dimensions smaller than 4.2cm × 4.2cm × 5.8cm that achieves sub-cellular resolution over a large field of view of ~24 mm2. This compact and light-weight microscope is based on digital in-line holography and does not need any lenses, bulky optical/mechanical components or coherent sources such as lasers. Instead, it utilizes a simple light-emitting-diode (LED) and a compact opto-electronic sensor-array to record lensless holograms of the objects, which then permits rapid digital reconstruction of regular transmission or differential interference contrast (DIC) images of the objects. Because this lensless incoherent holographic microscope has orders-of-magnitude improved light collection efficiency and is very robust to mechanical misalignments it may offer a cost-effective tool especially for telemedicine applications involving various global health problems in resource limited settings. PMID:20401422

  14. [Phenotype-based primary screening for drugs promoting neuronal subtype differentiation in embryonic stem cells with light microscope].

    Science.gov (United States)

    Gao, Yi-ning; Wang, Dan-ying; Pan, Zong-fu; Mei, Yu-qin; Wang, Zhi-qiang; Zhu, Dan-yan; Lou, Yi-jia

    2012-07-01

    To set up a platform for phenotype-based primary screening of drug candidates promoting neuronal subtype differentiation in embryonic stem cells (ES) with light microscope. Hanging drop culture 4-/4+ method was employed to harvest the cells around embryoid body (EB) at differentiation endpoint. Morphological evaluation for neuron-like cells was performed with light microscope. Axons for more than three times of the length of the cell body were considered as neuron-like cells. The compound(s) that promote neuron-like cells was further evaluated. Icariin (ICA, 10(-6)mol/L) and Isobavachin (IBA, 10(-7)mol/L) were selected to screen the differentiation-promoting activity on ES cells. Immunofluorescence staining with specific antibodies (ChAT, GABA) was used to evaluate the neuron subtypes. The cells treated with IBA showed neuron-like phenotype, but the cells treated with ICA did not exhibit the morphological changes. ES cells treated with IBA was further confirmed to be cholinergic and GABAergic neurons. Phenotypic screening with light microscope for molecules promoting neuronal differentiation is an effective method with advantages of less labor and material consuming and time saving, and false-positive results derived from immunofluorescence can be avoided. The method confirms that IBA is able to facilitate ES cells differentiating into neuronal cells, including cholinergic neurons and GABAergic neurons.

  15. Multiparameter breast cancer cell image analysis for objective estimation of nuclear grade: comparison with light microscopic observational data

    Science.gov (United States)

    Berzins, Juris; Sneiders, Uldis; Plegere, Daina; Freivalds, Talivaldis; Grigalinovica, Romalda

    2000-04-01

    We performed a multi parameter image analysis assessment of breast cancer cell population nuclear grade (NG), which is regarded as one of the main prognostic factors for treatment efficacy and survival of the patients and compared it with light microscopic estimation of NG. Cytological imprint slides from 20 ductal carcinomas were stained according to Leischmann-AzureII-eosine method, and NG was estimated by light microscopic observation according to Black in Fisher's modification. Simultaneously, using specially elaborated software, in each patient 100 cancer cells were analyzed for nuclear perimeter, diameter, area, nucleolar area, and average intensity of staining. The chromatin structure was assessed using mean diameter of chromatin grains and relatively chromatic are within the nucleus. Light microscopic estimation revealed 4/15 grade 2 and 7/15 grade 3 tumors out of 15 filtrating ductal carcinomas, with 4/15 classified as intermediate between grade 2-3. Multifactoral linear correlation coefficient r equals 0.39, p < 0.001 for ductal cancer, higher NG comes with increasing nucleolar area, nuclear roundness factor, nuclear are, and chromatin area within the cell nucleus. Image analysis may yield precise information on NG as a prognostic factor in breast cancer patients.

  16. Developments in Polarization and Energy Control of APPLE-II Undulators at Diamond Light Source

    International Nuclear Information System (INIS)

    Longhi, E C; Bencok, P; Dobrynin, A; Rial, E C M; Rose, A; Steadman, P; Thompson, C; Thomson, A; Wang, H

    2013-01-01

    A pair of 2m long APPLE-II type undulators have been built for the I10 BLADE beamline at Diamond Light Source. These 48mm period devices have gap as well as four moveable phase axes which provide the possibility to produce the full range of elliptical polarizations as well as linear polarization tilted through a full 180deg. The mechanical layout chosen has a 'master and slave' arrangement of the phase axes on the top and bottom. This arrangement allows the use of symmetries to provide operational ease for both changing energy using only the master phase while keeping fixed linear horizontal or circular polarization, as well as changing linear polarization angle while keeping fixed energy [1]. The design allows very fast motion of the master phase arrays, without sacrifice of accuracy, allowing the possibility of mechanical polarization switching at 1Hz for dichroism experiments. We present the mechanical design features of these devices, as well as the results of magnetic measurements and shimming from before installation. Finally, we present the results of characterization of these devices by the beamline, including polarimetry, which has been done on the various modes of motion to control energy and polarization. These modes of operation have been available to users since 2011.

  17. Developments in Polarization and Energy Control of APPLE-II Undulators at Diamond Light Source

    Science.gov (United States)

    Longhi, E. C.; Bencok, P.; Dobrynin, A.; Rial, E. C. M.; Rose, A.; Steadman, P.; Thompson, C.; Thomson, A.; Wang, H.

    2013-03-01

    A pair of 2m long APPLE-II type undulators have been built for the I10 BLADE beamline at Diamond Light Source. These 48mm period devices have gap as well as four moveable phase axes which provide the possibility to produce the full range of elliptical polarizations as well as linear polarization tilted through a full 180deg. The mechanical layout chosen has a 'master and slave' arrangement of the phase axes on the top and bottom. This arrangement allows the use of symmetries to provide operational ease for both changing energy using only the master phase while keeping fixed linear horizontal or circular polarization, as well as changing linear polarization angle while keeping fixed energy [1]. The design allows very fast motion of the master phase arrays, without sacrifice of accuracy, allowing the possibility of mechanical polarization switching at 1Hz for dichroism experiments. We present the mechanical design features of these devices, as well as the results of magnetic measurements and shimming from before installation. Finally, we present the results of characterization of these devices by the beamline, including polarimetry, which has been done on the various modes of motion to control energy and polarization. These modes of operation have been available to users since 2011.

  18. Control of polarization rotation in nonlinear propagation of fully structured light

    Science.gov (United States)

    Gibson, Christopher J.; Bevington, Patrick; Oppo, Gian-Luca; Yao, Alison M.

    2018-03-01

    Knowing and controlling the spatial polarization distribution of a beam is of importance in applications such as optical tweezing, imaging, material processing, and communications. Here we show how the polarization distribution is affected by both linear and nonlinear (self-focusing) propagation. We derive an analytical expression for the polarization rotation of fully structured light (FSL) beams during linear propagation and show that the observed rotation is due entirely to the difference in Gouy phase between the two eigenmodes comprising the FSL beams, in excellent agreement with numerical simulations. We also explore the effect of cross-phase modulation due to a self-focusing (Kerr) nonlinearity and show that polarization rotation can be controlled by changing the eigenmodes of the superposition, and physical parameters such as the beam size, the amount of Kerr nonlinearity, and the input power. Finally, we show that by biasing cylindrical vector beams to have elliptical polarization, we can vary the polarization state from radial through spiral to azimuthal using nonlinear propagation.

  19. Optical image encryption method based on incoherent imaging and polarized light encoding

    Science.gov (United States)

    Wang, Q.; Xiong, D.; Alfalou, A.; Brosseau, C.

    2018-05-01

    We propose an incoherent encoding system for image encryption based on a polarized encoding method combined with an incoherent imaging. Incoherent imaging is the core component of this proposal, in which the incoherent point-spread function (PSF) of the imaging system serves as the main key to encode the input intensity distribution thanks to a convolution operation. An array of retarders and polarizers is placed on the input plane of the imaging structure to encrypt the polarized state of light based on Mueller polarization calculus. The proposal makes full use of randomness of polarization parameters and incoherent PSF so that a multidimensional key space is generated to deal with illegal attacks. Mueller polarization calculus and incoherent illumination of imaging structure ensure that only intensity information is manipulated. Another key advantage is that complicated processing and recording related to a complex-valued signal are avoided. The encoded information is just an intensity distribution, which is advantageous for data storage and transition because information expansion accompanying conventional encryption methods is also avoided. The decryption procedure can be performed digitally or using optoelectronic devices. Numerical simulation tests demonstrate the validity of the proposed scheme.

  20. Modeling light entangled in polarization and frequency: case study in quantum cryptography

    Science.gov (United States)

    Myers, John M.

    2005-08-01

    With the recognition of a logical gap between experiments and equations of quantum mechanics comes: (1) a chance to clarify such purely mathematical entities as probabilities, density operators, and partial traces-separated out from the choices and judgments necessary to apply them to describing experiments with devices, and (2) an added freedom to invent equations by which to model devices, stemming from the corresponding freedom in interpreting how these equations connect to experiments. Here I apply a few of these clarifications and freedoms to model polarization-entangled light pulses called for in quantum key distribution (QKD). Available light pulses are entangled not only in polarization but also in frequency. Although absent from the simplified models that initiated QKD, the degree of frequency entanglement of polarization-entangled light pulses is shown to affect the amount of key that can be distilled from raw light signals, in one case by a factor of 4/3. Open questions remain, because QKD brings concepts of quantum decision theory, such as measures of distinguishability, mostly worked out in the context of finite-dimensional vector spaces, into contact with infinite-dimensional Hilbert spaces needed to give expression to optical frequency spectra.

  1. Two electric field Monte Carlo models of coherent backscattering of polarized light.

    Science.gov (United States)

    Doronin, Alexander; Radosevich, Andrew J; Backman, Vadim; Meglinski, Igor

    2014-11-01

    Modeling of coherent polarized light propagation in turbid scattering medium by the Monte Carlo method provides an ultimate understanding of coherent effects of multiple scattering, such as enhancement of coherent backscattering and peculiarities of laser speckle formation in dynamic light scattering (DLS) and optical coherence tomography (OCT) diagnostic modalities. In this report, we consider two major ways of modeling the coherent polarized light propagation in scattering tissue-like turbid media. The first approach is based on tracking transformations of the electric field along the ray propagation. The second one is developed in analogy to the iterative procedure of the solution of the Bethe-Salpeter equation. To achieve a higher accuracy in the results and to speed up the modeling, both codes utilize the implementation of parallel computing on NVIDIA Graphics Processing Units (GPUs) with Compute Unified Device Architecture (CUDA). We compare these two approaches through simulations of the enhancement of coherent backscattering of polarized light and evaluate the accuracy of each technique with the results of a known analytical solution. The advantages and disadvantages of each computational approach and their further developments are discussed. Both codes are available online and are ready for immediate use or download.

  2. The Effect of Incident Light Polarization on Vegetation Bidirectional Reflectance Factor

    Science.gov (United States)

    Georgiev, Georgi T.; Thome, Kurt; Ranson, Kurtis J.; King, Michael D.; Butler, James J.

    2010-01-01

    The Laboratory-based Bidirectional Reflectance Factor (BRF) polarization study of vegetation is presented in this paper. The BRF was measured using a short-arc Xenon lamp/monochromator assembly producing an incoherent, tunable light source with a well-defined spectral bandpass at visible and near-infrared wavelengths of interest at 470 nm and 870 nm and coherent light source at 1.656 microns. All vegetation samples were measured using P and S linearly polarized incident light over a range of incident and scatter angles. By comparing these results, we quantitatively examine how the BRF of the samples depends on the polarization of the incident light. The differences are significant, depend strongly on the incident and scatter angles, and can be as high as 120% at 67 deg incident and 470nm. The global nature of Earth's processes requires consistent long-term calibration of all instruments involved in data retrieval. The BRF defines the reflection characteristics of Earth surface. It provides the reflectance of a target in a specific direction as a function of illumination and viewing geometry. The BRF is a function of wavelength and reflects the structural and optical properties of the surface. Various space and airborne radiometric and imaging remote sensing instruments are used in the remote sensing characterization of vegetation canopies and soils, oceans, or especially large pollution sources. The satellite data is validated through comparison with airborne, ground-based and laboratory-based data in an effort to fully understand the vegetation canopy reflectance, The Sun's light is assumed to be unpolarized at the top of the atmosphere; however it becomes polarized to some degree due to atmospheric effects by the time it reaches the vegetation canopy. Although there are numerous atmospheric correction models, laboratory data is needed for model verification and improvement.

  3. Light microscopic identification and semiquantification of polyethylene particles in methylmethacrylate and paraffin-embedded experimental bone implant specimens

    DEFF Research Database (Denmark)

    Rahbek, O; Kold, S; Overgaard, S

    2005-01-01

    The aim of this study was to evaluate the identification of polyethylene (PE) particles in relatively thick methylmethacrylate (MMA) sections widely used in bone implant research. The sensitivity and specificity were compared between decalcified paraffin-embedded oil red O (ORO) stained and MMA......-embedded sections using polarized light. Furthermore, we introduced a grading system to semiquantify the level of PE particles in peri-implant tissue. Paraffin-embedded and MMA-embedded sections were compared concerning intra-observer agreement of the grading system. Moreover, the semiquantitative assessment...... of particle level was compared between the two section types. We found a sensitivity and specificity of polarized light of 100% for both paraffin ORO-stained and MMA sections. The intra-observer agreement on both types was comparable and acceptable. The ratings of differently processed blocks (MMA...

  4. Electrically switchable photonic liquid crystal devices for routing of a polarized light wave

    Science.gov (United States)

    Rushnova, Irina I.; Melnikova, Elena A.; Tolstik, Alexei L.; Muravsky, Alexander A.

    2018-04-01

    The new mode of LC alignment based on photoalignment AtA-2 azo dye where the refractive interface between orthogonal orientations of the LC director exists without voltage and disappeared or changed with critical voltage has been proposed. The technology to fabricate electrically controlled liquid crystal elements for spatial separation and switching of linearly polarized light beams on the basis of the total internal reflection effect has been significantly improved. Its distinctive feature is the application of a composite alignment material comprising two sublayers of Nylon-6 and AtA-2 photoalignment azo dye offering patterned liquid crystal director orientation with high alignment quality value q = 0 . 998. The fabricated electrically controlled spatially structured liquid crystal devices enable implementation of propagation directions separation for orthogonally polarized light beams and their switching with minimal crosstalk.

  5. Vector magnetometry based on electromagnetically induced transparency in linearly polarized light

    International Nuclear Information System (INIS)

    Yudin, V. I.; Taichenachev, A. V.; Dudin, Y. O.; Velichansky, V. L.; Zibrov, A. S.; Zibrov, S. A.

    2010-01-01

    We develop a generalized principle of electromagnetically induced transparency (EIT) vector magnetometry based on high-contrast EIT resonances and the symmetry of atom-light interaction in the linearly polarized bichromatic fields. Operation of such vector magnetometer on the D 1 line of 87 Rb has been demonstrated. The proposed compass-magnetometer has an increased immunity to shifts produced by quadratic Zeeman and ac-Stark effects, as well as by atom-buffer gas and atom-atom collisions. In our proof-of-principle experiment the detected angular sensitivity to magnetic field orientation is 10 -3 deg/Hz 1/2 , which is limited by laser intensity fluctuations, light polarization quality, and magnitude of the magnetic field.

  6. Multiple scattering of polarized light: comparison of Maxwell theory and radiative transfer theory.

    Science.gov (United States)

    Voit, Florian; Hohmann, Ansgar; Schäfer, Jan; Kienle, Alwin

    2012-04-01

    For many research areas in biomedical optics, information about scattering of polarized light in turbid media is of increasing importance. Scattering simulations within this field are mainly performed on the basis of radiative transfer theory. In this study a polarization sensitive Monte Carlo solution of radiative transfer theory is compared to exact Maxwell solutions for all elements of the scattering Müller matrix. Different scatterer volume concentrations are modeled as a multitude of monodisperse nonabsorbing spheres randomly positioned in a cubic simulation volume which is irradiated with monochromatic incident light. For all Müller matrix elements effects due to dependent scattering and multiple scattering are analysed. The results are in overall good agreement between the two methods with deviations related to dependent scattering being prominent for high volume concentrations and high scattering angles.

  7. Self-organized pattern formation upon femtosecond laser ablation by circularly polarized light

    International Nuclear Information System (INIS)

    Varlamova, Olga; Costache, Florenta; Reif, Juergen; Bestehorn, Michael

    2006-01-01

    Surface ripples generation upon femtosecond laser ablation is attributed to self-organized structure formation from instability. We report that linear arrangements are observed not only for linearly polarized light but also for ablation with circularly polarized light. Long ordered chains of spherical nanoparticles, reminding of bead-strings are almost parallel but exhibit typical non-linear dynamics features such as bifurcations. In a first attempt to understand the self-assembly, we rely on models recently developed for the description of similar structures upon ion beam erosion and for the simulation of instabilities in thin liquid films. Our picture describes an unstable surface layer, non-uniformly eroded through Coulomb repulsion between individual positive charges

  8. Harmonic radiation emission from periodic lattices irradiated by short-pulse elliptically polarized laser light.

    Science.gov (United States)

    Ondarza-Rovira, R; Boyd, T J

    2001-10-01

    Radiated emission at high-order harmonic numbers is observed from thin crystalline layers irradiated by short femtosecond elliptically polarized laser light. The applied external radiation field drives the free electrons in the material to large oscillation amplitudes and harmonics are generated by the electronic response to the periodic lattice potential. A model was modified by introducing a more general expression for the lattice force that by sharpening or by smoothing the potential in turn allows the strength of the electronic perturbation to be varied. The electron motion is computed numerically by solving the electromagnetic force equation and by regarding the lattice potential as a perturbative source. For linearly polarized laser light the radiation spectra are characterized by emission lines forming a flat plateau in the region of low harmonic orders with a sharp cutoff for higher numbers. For circular polarization strong emission is found for two harmonic numbers, the first in the low-harmonic region and the second around the cutoff. By solving analytically the electron motion in an elliptically polarized laser field, an exact expression for the electron displacement in all three spatial directions is found. The amplitude of the oscillations sets the analytic form for calculating the peak harmonic numbers emitted from the laser-lattice interaction. The radiation effect studied here, if detected, might hold some potential as a diagnostic and could be used, in principle, as a method for determining the lattice parameter in crystalline structures.

  9. Light and transmission electron microscopic studies on trophozoites and cyst-like stages of Histomonas meleagridis from cultures.

    Science.gov (United States)

    Munsch, Mareike; Lotfi, Abdulrahman; Hafez, Hafez Mohammed; Al-Quraishy, Saleh; Mehlhorn, H

    2009-02-01

    The present study deals with Berlin strains of Histomonas meleagridis, the specimens of which were cultivated in Dwyer's medium. The light and electron microscopic examination revealed that the cultivated trophozoite stages (reaching about 10 mum in size) appeared more or less spherical, although their surface (covered by a single membrane) showed amoeba-like waves. All stages were uni-nucleated and reproduced by binary fission with an extranuclear spindle apparatus. Some trophozoites appeared ovoid and possessed a single flagellum with a typical microtubular 9 x 2 + 2 arrangement. Furthermore, the latter were characterized by an inner row of typical microtubules (remnant of an axostyle) and a Golgi apparatus (both adjacent to the nucleus), multivesicular structures, hydrogenosomes, and many food vacuoles containing either starch grains or bacteria. Their cytoplasm was densely filled with glycogen granules and ribosomes. Similar stages were also documented in the caeca and cloaca of chicken when being inoculated (via cloaca) with such culture stages. In addition to these typical trophozoites, the cultures contained a low number of 10-mum-sized spherical cyst-like stages with a surrounding amorphous layer. The cytoplasm of some of these cyst-like stages-when studied by electron microscopy-appeared with two membranes or had formed an amorphic, cyst-wall-like layer at their surface, apparently corresponding to their light microscopical appearance. Such stages might be involved in transmission from one host to another and probably have been missed before in microscopical examinations of infected poultry.

  10. A compact two photon light sheet microscope for applications in neuroscience

    DEFF Research Database (Denmark)

    Piksarv, Peeter; Marti, Dominik; Le, Tuan

    2016-01-01

    We present a compact setup for two photon light sheet microscopy. By using pulsed Airy beam illumination we demonstrate eight-fold increase of the FOV compared to Gaussian light sheet with the same axial resolution....

  11. Quantitative light fluorescence (QLF) and polarized white light (PWL) assessments of dental fluorosis in an epidemiological setting.

    Science.gov (United States)

    Pretty, Iain A; McGrady, Michael; Zakian, Christian; Ellwood, Roger P; Taylor, Andrew; Sharif, Mohammed Owaise; Iafolla, Timothy; Martinez-Mier, E Angeles; Srisilapanan, Patcharawan; Korwanich, Narumanas; Goodwin, Michaela; Dye, Bruce A

    2012-05-20

    To determine if a novel dual camera imaging system employing both polarized white light (PWL) and quantitative light induced fluorescence imaging (QLF) is appropriate for measuring enamel fluorosis in an epidemiological setting. The use of remote and objective scoring systems is of importance in fluorosis assessments due to the potential risk of examiner bias using clinical methods. Subjects were recruited from a panel previously characterized for fluorosis and caries to ensure a range of fluorosis presentation. A total of 164 children, aged 11 years (±1.3) participated following consent. Each child was examined using the novel imaging system, a traditional digital SLR camera, and clinically using the Dean's and Thylstrup and Fejerskov (TF) Indices on the upper central and lateral incisors. Polarized white light and SLR images were scored for both Dean's and TF indices by raters and fluorescence images were automatically scored using software. Data from 164 children were available with a good distribution of fluorosis severity. The automated software analysis of QLF images demonstrated significant correlations with the clinical examinations for both Dean's and TF index. Agreement (measured by weighted Kappa's) between examiners scoring clinically, from polarized photographs and from SLR images ranged from 0.56 to 0.92. The study suggests that the use of a digital imaging system to capture images for either automated software analysis, or remote assessment by raters is suitable for epidemiological work. The use of recorded images enables study archiving, assessment by multiple examiners, remote assessment and objectivity due to the blinding of subject status.

  12. Quantitative Light Fluorescence (QLF and Polarized White Light (PWL assessments of dental fluorosis in an epidemiological setting

    Directory of Open Access Journals (Sweden)

    Pretty Iain A

    2012-05-01

    Full Text Available Abstract Background To determine if a novel dual camera imaging system employing both polarized white light (PWL and quantitative light induced fluorescence imaging (QLF is appropriate for measuring enamel fluorosis in an epidemiological setting. The use of remote and objective scoring systems is of importance in fluorosis assessments due to the potential risk of examiner bias using clinical methods. Methods Subjects were recruited from a panel previously characterized for fluorosis and caries to ensure a range of fluorosis presentation. A total of 164 children, aged 11 years (±1.3 participated following consent. Each child was examined using the novel imaging system, a traditional digital SLR camera, and clinically using the Dean’s and Thylstrup and Fejerskov (TF Indices on the upper central and lateral incisors. Polarized white light and SLR images were scored for both Dean’s and TF indices by raters and fluorescence images were automatically scored using software. Results Data from 164 children were available with a good distribution of fluorosis severity. The automated software analysis of QLF images demonstrated significant correlations with the clinical examinations for both Dean’s and TF index. Agreement (measured by weighted Kappa’s between examiners scoring clinically, from polarized photographs and from SLR images ranged from 0.56 to 0.92. Conclusions The study suggests that the use of a digital imaging system to capture images for either automated software analysis, or remote assessment by raters is suitable for epidemiological work. The use of recorded images enables study archiving, assessment by multiple examiners, remote assessment and objectivity due to the blinding of subject status.

  13. THE EFFECT OF GRAVITATION ON THE POLARIZATION STATE OF A LIGHT RAY

    Energy Technology Data Exchange (ETDEWEB)

    Ghosh, Tanay; Sen, A. K. [Department of Physics Assam University, Silchar-788011, Assam (India)

    2016-12-10

    In the present work, detailed calculations have been carried out on the rotation of the polarization vector of an electromagnetic wave due to the presence of a gravitational field of a rotating body. This has been done using the general expression of Maxwell’s equation in curved spacetime. Considering the far-field approximation (i.e., the impact parameter is greater than the Schwarzschild radius and rotation parameter), the amount of rotation of the polarization vector as a function of impact parameter has been obtained for a rotating body (considering Kerr geometry). The present work shows that the rotation of the polarization vector cannot be observed in the case of Schwarzschild geometry. This work also calculates the rotational effect when considering prograde and retrograde orbits for the light ray. Although the present work demonstrates the effect of rotation of the polarization vector, it confirms that there would be no net polarization of an electromagnetic wave due to the curved spacetime geometry in a Kerr field.

  14. [Getting an insight into the brain - new optical clearing techniques and imaging using light-sheet microscope].

    Science.gov (United States)

    Pawłowska, Monika; Legutko, Diana; Stefaniuk, Marzena

    2017-01-01

    One of the biggest challenges in neuroscience is to understand how brain operates. For this, it would be the best to image the whole brain with at least cellular resolution, preserving the three-dimensional structure in order to capture the connections between different areas. Most currently available high-resolution imaging techniques are based on preparing thin brain sections that are next photographed one by one and subsequently bigger structures are reconstructed. These techniques are laborious and create artifacts. Recent optical clearing methods allow to obtain literally transparent brains that can be imaged using light-sheet microscope. The present review summarizes the most popular optical clearing techniques, describing their different mechanisms and comparing advantages and disadvantages of different approaches, and presents the principle of light-sheet microscopy and its use in imaging. Finally, it gives examples of application of optical tissue clearing and light-sheet imaging in neuroscience and beyond it.

  15. Influence of InAlN Nanospiral Structures on the Behavior of Reflected Light Polarization

    Directory of Open Access Journals (Sweden)

    Yu-Hung Kuo

    2018-03-01

    Full Text Available The influence of structural configurations of indium aluminum nitride (InAlN nanospirals, grown by reactive magnetron sputter epitaxy, on the transformation of light polarization are investigated in terms of varying structural chirality, growth temperatures, titanium nitride (TiN seed (buffer layer thickness, nanospiral thickness, and pitch. The handedness of reflected circularly polarized light in the ultraviolet–visible region corresponding to the chirality of nanospirals is demonstrated. A high degree of circular polarization (Pc value of 0.75 is obtained from a sample consisting of 1.2 μm InAlN nanospirals grown at 650 °C. A film-like structure is formed at temperatures lower than 450 °C. At growth temperatures higher than 750 °C, less than 0.1 In-content is incorporated into the InAlN nanospirals. Both cases reveal very low Pc. A red shift of wavelength at Pc peak is found with increasing nanospiral pitch in the range of 200–300 nm. The Pc decreases to 0.37 for two-turn nanospirals with total length of 0.7 μm, attributed to insufficient constructive interference. A branch-like structure appears on the surface when the nanospirals are grown longer than 1.2 μm, which yields a low Pc around 0.5, caused by the excessive scattering of incident light.

  16. [Suppression of visceral pain by action of the low intensity polarized light on acupuncture antinociceptive points].

    Science.gov (United States)

    Lymans'kyĭ, Iu P; Tamarova, Z A; Huliar, S O

    2003-01-01

    In experiments on mice, statistically authentic weakening of visceral pain has been shown after an action of low intensity polarized light from a device Bioptron on antinociceptive acupuncture points (AP). Pain was caused by an intraperitoneal injection of 2% acetic acid (0.1 ml/10 g). The intensity of pain was judged on duration and frequency of painful behavioral reactions (writhing, licking of abdomen), as well as on duration of sleep, eating and motor activity. In animals which immediately after injections of acetic acid were exposed to polarized light of low intensity for 10 min, applied on any of antinociceptive APs (E-36, E-43, VC-8, RP-6), the duration of painful behavioral reaction was determined to be reduced, while that of non-painful one increased. The comparison of the total duration of the writhing at control and experimental mice showed that an activation of AP E-43 induced the greatest analgesic effect (76.5%), from AP VC-8 it was 76.3%, from RP-6--46.8%, and from E-36--41.4%. We have concluded that the effect of polarized light of low intensity on APs was a convenient non-pharmacological method of treating visceral pain.

  17. Electron beam excitation assisted optical microscope with ultra-high resolution.

    Science.gov (United States)

    Inami, Wataru; Nakajima, Kentaro; Miyakawa, Atsuo; Kawata, Yoshimasa

    2010-06-07

    We propose electron beam excitation assisted optical microscope, and demonstrated its resolution higher than 50 nm. In the microscope, a light source in a few nanometers size is excited by focused electron beam in a luminescent film. The microscope makes it possible to observe dynamic behavior of living biological specimens in various surroundings, such as air or liquids. Scan speed of the nanometric light source is faster than that in conventional near-field scanning optical microscopes. The microscope enables to observe optical constants such as absorption, refractive index, polarization, and their dynamic behavior on a nanometric scale. The microscope opens new microscopy applications in nano-technology and nano-science.

  18. Low Efficiency Upconversion Nanoparticles for High-Resolution Coalignment of Near-Infrared and Visible Light Paths on a Light Microscope.

    Science.gov (United States)

    Sundaramoorthy, Sriramkumar; Garcia Badaracco, Adrian; Hirsch, Sophia M; Park, Jun Hong; Davies, Tim; Dumont, Julien; Shirasu-Hiza, Mimi; Kummel, Andrew C; Canman, Julie C

    2017-03-08

    The combination of near-infrared (NIR) and visible wavelengths in light microscopy for biological studies is increasingly common. For example, many fields of biology are developing the use of NIR for optogenetics, in which an NIR laser induces a change in gene expression and/or protein function. One major technical barrier in working with both NIR and visible light on an optical microscope is obtaining their precise coalignment at the imaging plane position. Photon upconverting particles (UCPs) can bridge this gap as they are excited by NIR light but emit in the visible range via an anti-Stokes luminescence mechanism. Here, two different UCPs have been identified, high-efficiency micro 540 -UCPs and lower efficiency nano 545 -UCPs, that respond to NIR light and emit visible light with high photostability even at very high NIR power densities (>25 000 Suns). Both of these UCPs can be rapidly and reversibly excited by visible and NIR light and emit light at visible wavelengths detectable with standard emission settings used for Green Fluorescent Protein (GFP), a commonly used genetically encoded fluorophore. However, the high efficiency micro 540 -UCPs were suboptimal for NIR and visible light coalignment, due to their larger size and spatial broadening from particle-to-particle energy transfer consistent with a long-lived excited state and saturated power dependence. In contrast, the lower efficiency nano-UCPs were superior for precise coalignment of the NIR beam with the visible light path (∼2 μm versus ∼8 μm beam broadening, respectively) consistent with limited particle-to-particle energy transfer, superlinear power dependence for emission, and much smaller particle size. Furthermore, the nano-UCPs were superior to a traditional two-camera method for NIR and visible light path alignment in an in vivo Infrared-Laser-Evoked Gene Operator (IR-LEGO) optogenetics assay in the budding yeast Saccharomyces cerevisiae. In summary, nano-UCPs are powerful new tools

  19. Low efficiency upconversion nanoparticles for high-resolution coalignment of near-infrared and visible light paths on a light microscope

    Science.gov (United States)

    Sundaramoorthy, Sriramkumar; Badaracco, Adrian Garcia; Hirsch, Sophia M.; Park, Jun Hong; Davies, Tim; Dumont, Julien; Shirasu-Hiza, Mimi; Kummel, Andrew C.; Canman, Julie C.

    2017-01-01

    The combination of near infrared (NIR) and visible wavelengths in light microscopy for biological studies is increasingly common. For example, many fields of biology are developing the use of NIR for optogenetics, in which an NIR laser induces a change in gene expression and/or protein function. One major technical barrier in working with both NIR and visible light on an optical microscope is obtaining their precise coalignment at the imaging plane position. Photon upconverting particles (UCPs) can bridge this gap as they are excited by NIR light but emit in the visible range via an anti-Stokes luminescence mechanism. Here, two different UCPs have been identified, high-efficiency micro540-UCPs and lower efficiency nano545-UCPs, that respond to NIR light and emit visible light with high photostability even at very high NIR power densities (>25,000 Suns). Both of these UCPs can be rapidly and reversibly excited by visible and NIR light and emit light at visible wavelengths detectable with standard emission settings used for Green Fluorescent Protein (GFP), a commonly used genetically-encoded fluorophore. However, the high efficiency micro540-UCPs were suboptimal for NIR and visible light coalignment, due to their larger size and spatial broadening from particle-to-particle energy transfer consistent with a long lived excited state and saturated power dependence. In contrast, the lower efficiency nano-UCPs were superior for precise coalignment of the NIR beam with the visible light path (~2 µm versus ~8 µm beam broadening respectively) consistent with limited particle-to-particle energy transfer, superlinear power dependence for emission, and much smaller particle size. Furthermore, the nano-UCPs were superior to a traditional two-camera method for NIR and visible light path alignment in an in vivo Infrared-Laser-Evoked Gene Operator (IR-LEGO) optogenetics assay in the budding yeast S. cerevisiae. In summary, nano-UCPs are powerful new tools for coaligning NIR and

  20. Versatile maskless microscope projection photolithography system and its application in light-directed fabrication of DNA microarrays

    Science.gov (United States)

    Naiser, Thomas; Mai, Timo; Michel, Wolfgang; Ott, Albrecht

    2006-06-01

    We present a maskless microscope projection lithography system (MPLS), in which photomasks have been replaced by a Digital Micromirror Device type spatial light modulator (DMD™, Texas Instruments). Employing video projector technology high resolution patterns, designed as bitmap images on the computer, are displayed using a micromirror array consisting of about 786 000 tiny individually addressable tilting mirrors. The DMD, which is located in the image plane of an infinity corrected microscope, is projected onto a substrate placed in the focal plane of the microscope objective. With a 5× [0.25 NA (numerical aperture)] Fluar microscope objective, a fivefold reduction of the image to a total size of 9mm2 and a minimum feature size of 3.5μm is achieved. The ultrahigh pressure lamp of a video projector is a cheap, durable, and powerful alternative to the mercury arc lamps commonly used in lithography applications. The MPLS may be employed in standard photolithography. We have successfully produced patterns in 40μm films of SU-8 photoresist, with an aspect ratio of about 1:10. Our system can be used in the visible range as well as in the near UV (with a light intensity of up to 76mW/cm2 around the 365nm Hg line). We developed an inexpensive and simple method to enable exact focusing and controlling of the image quality of the projected patterns. Our MPLS has originally been designed for the light-directed in situ synthesis of DNA microarrays. One requirement is a high UV intensity to keep the fabrication process reasonably short. Another demand is a sufficient contrast ratio over small distances (of about 5μm). This is necessary to achieve a high density of features (i.e., separated sites on the substrate at which different DNA sequences are synthesized in parallel fashion) while at the same time the number of stray light induced DNA sequence errors is kept reasonably small. We demonstrate the performance of the apparatus in light-directed DNA chip synthesis and

  1. Frequency dependent detection in a STED microscope using modulated excitation light.

    Science.gov (United States)

    Ronzitti, Emiliano; Harke, Benjamin; Diaspro, Alberto

    2013-01-14

    We present a novel concept adaptable to any kind of STED microscope in order to expand the limited number of compatible dyes for performing super resolution imaging. The approach is based on an intensity modulated excitation beam in combination with a frequency dependent detection in the form of a standard lock-in amplifier. This enables to unmix fluorescence signal originated by the excitation beam from the fluorescence caused by the STED beam. The benefit of this concept is demonstrated by imaging biological samples as well as fluorescent spheres, whose spectrum does not allow STED imaging in the conventional way. Our concept is suitable with CW or pulsed STED microscope and can thereby be seen as a general improvement adaptable to any existing setup.

  2. A modular designed ultra-high-vacuum spin-polarized scanning tunneling microscope with controllable magnetic fields for investigating epitaxial thin films.

    Science.gov (United States)

    Wang, Kangkang; Lin, Wenzhi; Chinchore, Abhijit V; Liu, Yinghao; Smith, Arthur R

    2011-05-01

    A room-temperature ultra-high-vacuum scanning tunneling microscope for in situ scanning freshly grown epitaxial films has been developed. The core unit of the microscope, which consists of critical components including scanner and approach motors, is modular designed. This enables easy adaptation of the same microscope units to new growth systems with different sample-transfer geometries. Furthermore the core unit is designed to be fully compatible with cryogenic temperatures and high magnetic field operations. A double-stage spring suspension system with eddy current damping has been implemented to achieve ≤5 pm z stability in a noisy environment and in the presence of an interconnected growth chamber. Both tips and samples can be quickly exchanged in situ; also a tunable external magnetic field can be introduced using a transferable permanent magnet shuttle. This allows spin-polarized tunneling with magnetically coated tips. The performance of this microscope is demonstrated by atomic-resolution imaging of surface reconstructions on wide band-gap GaN surfaces and spin-resolved experiments on antiferromagnetic Mn(3)N(2)(010) surfaces.

  3. Congenital adenoma of the iris and ciliary body: light and electron microscopic observations.

    OpenAIRE

    Rennie, I G; Parsons, M A; Palmer, C A

    1992-01-01

    A 23-year-old man had a lesion in the right inferior iris which appeared to have enlarged since it was first seen when the patient was aged 5 years. The lesion was excised by a partial iridocyclectomy. Histopathologically the neoplasm was composed of both pigmented and non-pigmented cells. Pseudoacini, containing acid mucopolysaccharides, were present throughout the tumour matrix. Electron microscopically the non-pigmented cells were found to possess a convoluted plasmalemma, abundant rough e...

  4. Expression of calcium channel CaV1.3 in cat spinal cord: light and electron microscopic immunohistochemical study

    DEFF Research Database (Denmark)

    Zhang, Mengliang; Møller, Morten; Broman, Jonas

    2008-01-01

    in the cat spinal cord by light and electron microscopic immunohistochemistry. The results show that Ca(V)1.3-like immunoreactivity is widely distributed in all segments of the spinal cord but that the distribution in the different laminae of the spinal gray matter varies, with the highest density of labeled...... associated with the rough endoplasmic reticulum but some also with the plasma membrane. In dendrites, they were associated with both intracellular organelles, including microtubules and microchondria, and the plasma membrane. These results indicate that significant proportions of the neurons in cat spinal...

  5. Determining the fibrillar orientation of bast fibres with polarized light microscopy: the modified Herzog test (red plate test) explained.

    Science.gov (United States)

    Haugan, E; Holst, B

    2013-11-01

    The identification of bast fibre samples, in particular, bast fibres used in textiles, is an important issue in archaeology, criminology and other scientific fields. One of the characteristic features of bast fibres is their fibrillar orientation, referred to as Z- or S twist (or alternatively right- and left-handed fibres). An empirical test for determining the fibrillar orientation using polarized light microscopy has been known in the community for many years. It is referred to as the modified Herzog test or red plate test. The test has the reputation for never producing false results, but also for occasionally not working. However, so far, no proper justification has been provided in the literature that the 'no false results' assumption is really correct and it has also not been clear up till now, why the method sometimes does not work. In this paper, we present an analytical model for the modified Herzog test, which explains why the test never gives a false result. We also provide an explanation for why the Herzog test sometimes does not work: According to our model, the Herzog test will not work if none of the three distinct layers in the secondary cell wall is significantly thicker than the others. © 2013 The Authors Journal of Microscopy © 2013 Royal Microscopical Society.

  6. Electric field Monte Carlo simulation of polarized light propagation in turbid media.

    Science.gov (United States)

    Xu, Min

    2004-12-27

    A Monte Carlo method based on tracing the multiply scattered electric field is presented to simulate the propagation of polarized light in turbid media. Multiple scattering of light comprises a series of updates of the parallel and perpendicular components of the complex electric field with respect to the scattering plane by the amplitude scattering matrix and rotations of the local coordinate system spanned by the unit vectors in the directions of the parallel and perpendicular electric field components and the propagation direction of light. The backscattering speckle pattern and the backscattering Mueller matrix of an aqueous suspension of polystyrene spheres in a slab geometry are computed using this Electric Field Monte Carlo (EMC) method. An efficient algorithm computing the Mueller matrix in the pure backscattering direction is detailed in the paper.

  7. Anisotropy-Guided Enantiomeric Enhancement in Alanine Using Far-UV Circularly Polarized Light.

    Science.gov (United States)

    Meinert, Cornelia; Cassam-Chenaï, Patrick; Jones, Nykola C; Nahon, Laurent; Hoffmann, Søren V; Meierhenrich, Uwe J

    2015-06-01

    All life on Earth is characterized by its asymmetry - both the genetic material and proteins are composed of homochiral monomers. Understanding how this molecular asymmetry initially arose is a key question related to the origins of life. Cometary ice simulations, L-enantiomeric enriched amino acids in meteorites and the detection of circularly polarized electromagnetic radiation in star-forming regions point to a possible interstellar/protostellar generation of stereochemical asymmetry. Based upon our recently recorded anisotropy spectra g(λ) of amino acids in the vacuum-UV range, we subjected amorphous films of racemic (13)C-alanine to far-UV circularly polarized synchrotron radiation to probe the asymmetric photon-molecule interaction under interstellar conditions. Optical purities of up to 4% were reached, which correlate with our theoretical predictions. Importantly, we show that chiral symmetry breaking using circularly polarized light is dependent on both the helicity and the wavelength of incident light. In order to predict such stereocontrol, time-dependent density functional theory was used to calculate anisotropy spectra. The calculated anisotropy spectra show good agreement with the experimental ones. The European Space Agency's Rosetta mission, which successfully landed Philae on comet 67P/Churyumov-Gerasimenko on 12 November 2014, will investigate the configuration of chiral compounds and thereby obtain data that are to be interpreted in the context of the results presented here.

  8. Simultaneously improving optical absorption of both transverse-electric polarized and transverse-magnetic polarized light for organic solar cells with Ag grating used as transparent electrode

    Directory of Open Access Journals (Sweden)

    Yongbing Long

    2014-08-01

    Full Text Available Theoretical simulations are performed to investigate optical performance of organic solar cells with Ag grating electrode. It is demonstrated that optical absorption for both transverse-electric (TE polarized and transverse-magnetic(TM polarized light is simultaneously improved when compared with that for the device without the Ag grating. The improvement is respectively attributed to the resonance and the surface plasmon polaritons within the device. After an additional WO3 layer is capped on the Ag grating, absorption of TE-polarized light is further improved due to resonance of double microcavities within the device, and absorption of TM-polarized light is improved by the combined effects of the microcavity resonance and the surface plasmon polaritons. Correspondingly, the short current density for randomly polarized light is improved by 18.1% from that of the device without the Ag grating. Finally, it is demonstrated that high transmission may not be an essential prerequisite for metallic gratings when they are used as transparent electrode since absorption loss caused by low transmission can be compensated by using a capping layer to optimize optical resonance of the WMC structure within the device.

  9. Coupling between surface plasmon polaritons and transverse electric polarized light via L-shaped nano-apertures.

    Science.gov (United States)

    Yang, Jing; Hu, Chuang; Wen, Qiuling; Zhao, Chenglong; Zhang, Jiasen

    2015-03-15

    Given that plasmonic fields are intrinsically transverse magnetic (TM), coupling surface plasmon polaritons (SPPs) and transverse electric (TE) polarized light, especially at nanoscale, remain challenging. We propose the use of L-shaped nano-apertures to overcome this fundamental limitation and enable coupling between SPPs and TE polarized light. Polarization conversion originates from the interference of two resonant modes excited in the nano-apertures and the nearly 180° phase retardation between them. The experiments show that both TE-to-plasmon and plasmon-to-TE couplings can be implemented at the subwavelength scale. This discovery provides great freedom when manipulating light based on SPPs at the nanoscale and helps in using the energy of TE polarized light.

  10. BRIEF COMMUNICATIONS: Investigation of the state of polarization of light in a single-mode fiber waveguide

    Science.gov (United States)

    Kozel, S. M.; Kreopalov, V. I.; Listvin, V. N.; Glavatskikh, N. A.

    1983-01-01

    An analysis is made of the polarization anisotropy of a single-mode fiber with a twisted elliptic core. The Jones matrix is obtained and the complex function of the state of polarization of light in a fiber is investigated. The results are reported of measurements of the linear and circular birefringence of a borosilicate single-mode glass fiber.

  11. Theory for Spin Selective Andreev Re ection in Vortex Core of Topological Superconductor: Majorana Zero Modes on Spherical Surface and Application to Spin Polarized Scanning Tunneling Microscope Probe

    Science.gov (United States)

    Zhang, Fu-Chun; Hu, Lun-Hui; Li, Chuang; Xu, Dong-Hui; Zhou, Yi

    Majorana zero modes (MZMs) have been predicted to exist in the topological insulator (TI)/superconductor (SC) heterostructure. Recent spin polarized scanning tunneling microscope(STM) experiment has observed spin-polarization dependence of the zero bias differential tunneling conductance at the center of vortex core. Here we consider a helical electron system described by a Rashba spin orbit coupling Hamiltonian on a spherical surface with a s-wave superconducting pairing due to proximity effect. We examine in-gap excitations of a pair of vortices with one at the north pole and the other at the south pole. While the MZM is not a spin eigenstate, the spin wavefunction of the MZM at the center of the vortex core, r = 0, is parallel to the magnetic field, and the local Andreev reflection of the MZM is spin selective, namely occurs only when the STM tip has the spin polarization parallel to the magnetic field, similar to the case in 1-dimensional nanowire. The total local differential tunneling conductance consists of the normal term proportional to the local density of states and an additional term arising from the Andreev reflection. We apply our theory to examine the recently reported spin-polarized STM experiments and show good agreement with the experiments

  12. Microscopic calculations of elastic scattering between light nuclei based on a realistic nuclear interaction

    Energy Technology Data Exchange (ETDEWEB)

    Dohet-Eraly, Jeremy [F.R.S.-FNRS (Belgium); Sparenberg, Jean-Marc; Baye, Daniel, E-mail: jdoheter@ulb.ac.be, E-mail: jmspar@ulb.ac.be, E-mail: dbaye@ulb.ac.be [Physique Nucleaire et Physique Quantique, CP229, Universite Libre de Bruxelles (ULB), B-1050 Brussels (Belgium)

    2011-09-16

    The elastic phase shifts for the {alpha} + {alpha} and {alpha} + {sup 3}He collisions are calculated in a cluster approach by the Generator Coordinate Method coupled with the Microscopic R-matrix Method. Two interactions are derived from the realistic Argonne potentials AV8' and AV18 with the Unitary Correlation Operator Method. With a specific adjustment of correlations on the {alpha} + {alpha} collision, the phase shifts for the {alpha} + {alpha} and {alpha} + {sup 3}He collisions agree rather well with experimental data.

  13. Electric field Monte Carlo simulation of coherent backscattering of polarized light by a turbid medium containing Mie scatterers.

    Science.gov (United States)

    Sawicki, John; Kastor, Nikolas; Xu, Min

    2008-04-14

    A method for directly simulating coherent backscattering of polarized light by a turbid medium has been developed based on the Electric field Monte Carlo (EMC) method. Electric fields of light traveling in a pair of time-reversed paths are added coherently to simulate their interference. An efficient approach for computing the electric field of light traveling along a time-reversed path is derived and implemented based on the time-reversal symmetry of electromagnetic waves. Coherent backscattering of linearly and circularly polarized light by a turbid medium containing Mie scatterers is then investigated using this method.

  14. Light trapping and circularly polarization at a Dirac point in 2D plasma photonic crystals

    Science.gov (United States)

    Li, Qian; Hu, Lei; Mao, Qiuping; Jiang, Haiming; Hu, Zhijia; Xie, Kang; Wei, Zhang

    2018-03-01

    Light trapping at the Dirac point in 2D plasma photonic crystal has been obtained. The new localized mode, Dirac mode, is attributable to neither photonic bandgap nor total internal reflection. It exhibits a unique algebraic profile and possesses a high-Q factor resonator of about 105. The Dirac point could be modulated by tuning the filling factor, plasma frequency and plasma cyclotron frequency, respectively. When a magnetic field parallel to the wave vector is applied, Dirac modes for right circularly polarized and left circularly polarized waves could be obtained at different frequencies, and the Q factor could be tuned. This property will add more controllability and flexibility to the design and modulation of novel photonic devices. It is also valuable for the possibilities of Dirac modes in photonic crystal containing other kinds of metamaterials.

  15. Ultrastructure and light microscope analysis of intact skin after a varying number of low level laser irradiations in mice.

    Science.gov (United States)

    Iyomasa, Mamie Mizusaki; Leão, Juliane Caroline; Rizzi, Élen Camargo; Issa, João Paulo Mardegan; Dias, Fernando José; Watanabe, Ii-sei; Iyomasa, Daniela Mizusaki

    2014-01-01

    Low level laser therapy (LLLT) has been used to relieve pain, inflammation, and wound healing processes. Thus, the skin is overexposed to laser and this effect is not completely understood. This study analyzed the effects of the number of laser applications (three, six, and 10) on the intact skin of the masseteric region in mice of strain HRS/J. The animals (n = 30) were equally divided into control (0 J/cm(2)) and irradiated (20 J/cm(2)), and each of these groups was further equally divided according to the number of laser applications (three, six, and 10) and underwent LLLT on alternate days. Samples were analyzed by light microscopy and transmission electron microscope (TEM). The animals receiving applications exhibited open channels more dilated between the keratinocytes and photobiomodulation effect on endothelial cells and fibroblasts by TEM. Under the light microscope after 10 laser applications, the type I collagen decreased (P < 0.05) compared to the three and six applications. Under these experimental conditions, all numbers of applications provided photobiomodulatory effect on the epidermis and dermis, without damage. More studies are needed to standardize the energy density and number of applications recommended for laser therapy to have a better cost-benefit ratio associated with treatment.

  16. Light Microscopy Module: An On-Orbit Microscope Planned for the Fluids and Combustion Facility on the International Space Station

    Science.gov (United States)

    Doherty, Michael P.; Motil, Susan M.; Snead, John H.; Griffin, DeVon W.

    2001-01-01

    The Light Microscopy Module (LMM) is planned as a fully remotely controllable on-orbit microscope subrack facility, allowing flexible scheduling and control of fluids and biology experiments within NASA Glenn Research Center's Fluids and Combustion Facility on the International Space Station. Within the Fluids and Combustion Facility, four fluids physics experiments will utilize an instrument built around a light microscope. These experiments are the Constrained Vapor Bubble experiment (Peter C. Wayner of Rensselaer Polytechnic Institute), the Physics of Hard Spheres Experiment-2 (Paul M. Chaikin of Princeton University), the Physics of Colloids in Space-2 experiment (David A. Weitz of Harvard University), and the Low Volume Fraction Colloidal Assembly experiment (Arjun G. Yodh of the University of Pennsylvania). The first experiment investigates heat conductance in microgravity as a function of liquid volume and heat flow rate to determine, in detail, the transport process characteristics in a curved liquid film. The other three experiments investigate various complementary aspects of the nucleation, growth, structure, and properties of colloidal crystals in microgravity and the effects of micromanipulation upon their properties. Key diagnostic capabilities for meeting the science requirements of the four experiments include video microscopy to observe sample features including basic structures and dynamics, interferometry to measure vapor bubble thin film thickness, laser tweezers for colloidal particle manipulation and patterning, confocal microscopy to provide enhanced three-dimensional visualization of colloidal structures, and spectrophotometry to measure colloidal crystal photonic properties.

  17. Dynamic Ca2+ imaging with a simplified lattice light-sheet microscope: A sideways view of subcellular Ca2+ puffs.

    Science.gov (United States)

    Ellefsen, Kyle L; Parker, Ian

    2018-05-01

    We describe the construction of a simplified, inexpensive lattice light-sheet microscope, and illustrate its use for imaging subcellular Ca 2+ puffs evoked by photoreleased i-IP 3 in cultured SH-SY5Y neuroblastoma cells loaded with the Ca 2+ probe Cal520. The microscope provides sub-micron spatial resolution and enables recording of local Ca 2+ transients in single-slice mode with a signal-to-noise ratio and temporal resolution (2ms) at least as good as confocal or total internal reflection microscopy. Signals arising from openings of individual IP 3 R channels are clearly resolved, as are stepwise changes in fluorescence reflecting openings and closings of individual channels during puffs. Moreover, by stepping the specimen through the light-sheet, the entire volume of a cell can be scanned within a few hundred ms. The ability to directly visualize a sideways (axial) section through cells directly reveals that IP 3 -evoked Ca 2+ puffs originate at sites in very close (≤a few hundred nm) to the plasma membrane, suggesting they play a specific role in signaling to the membrane. Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. Wave optics theory and 3-D deconvolution for the light field microscope.

    Science.gov (United States)

    Broxton, Michael; Grosenick, Logan; Yang, Samuel; Cohen, Noy; Andalman, Aaron; Deisseroth, Karl; Levoy, Marc

    2013-10-21

    Light field microscopy is a new technique for high-speed volumetric imaging of weakly scattering or fluorescent specimens. It employs an array of microlenses to trade off spatial resolution against angular resolution, thereby allowing a 4-D light field to be captured using a single photographic exposure without the need for scanning. The recorded light field can then be used to computationally reconstruct a full volume. In this paper, we present an optical model for light field microscopy based on wave optics, instead of previously reported ray optics models. We also present a 3-D deconvolution method for light field microscopy that is able to reconstruct volumes at higher spatial resolution, and with better optical sectioning, than previously reported. To accomplish this, we take advantage of the dense spatio-angular sampling provided by a microlens array at axial positions away from the native object plane. This dense sampling permits us to decode aliasing present in the light field to reconstruct high-frequency information. We formulate our method as an inverse problem for reconstructing the 3-D volume, which we solve using a GPU-accelerated iterative algorithm. Theoretical limits on the depth-dependent lateral resolution of the reconstructed volumes are derived. We show that these limits are in good agreement with experimental results on a standard USAF 1951 resolution target. Finally, we present 3-D reconstructions of pollen grains that demonstrate the improvements in fidelity made possible by our method.

  19. Intracellular photoreceptive site for blue light-induced cell division in protonemata of the fern Adiantum [Pteridophyta]: Further analyses by polarized light irradiation and cell centrifugation

    International Nuclear Information System (INIS)

    Kadota, A.; Fushimi, Y.; Wada, M.

    1986-01-01

    The intracellular localization of the photoreceptive site for blue light-induced cell division in single-celled protonemata of Adiantum capillus-veneris L. was investigated using polarized light irradiation and protonemal cell centrifugation. The response to irradiation with polarized blue light showed no dependence on the direction of light polarization. However, centrifugation of the protonemata followed by microbeam irradiation showed that the site of blue light perception could be displaced together with the nucleus. Centrifugal treatment changed the distribution of intracellular organelles at the time of light exposure and basipetally displaced the nucleus about 90μm. This treatment had no effect on the induction of cell division with blue light if the protonemata were centrifuged again acropetally after the light treatment. Microbeam (30×30 μm2) irradiation with blue light of the apical 45–75 βm region, the receptive site of blue light in non-centrifuged cell, did not induce cell division. However, cell division was induced by irradiation of the nucleus-containing region, indicating that the photoreceptive site was displaced together with the nucleus by the centrifugation. These results suggest that the blue light receptor regulating cell division in Adiantum protonemata is not likely to be located on the plasma membrane. (author)

  20. Miniature magnetic bottle confined by circularly polarized laser light and measurements of the inverse Faraday effect in plasmas

    International Nuclear Information System (INIS)

    Eliezer, S.; Paiss, Y.; Horovitz, Y.; Henis, Z.

    1997-01-01

    A new concept of hot plasma confinement in a miniature magnetic bottle induced by circularly polarized laser light is suggested. Magnetic fields generated by circularly polarized laser light may be of the order of megagauss, depending on the laser intensity. In this configuration the circularly polarized light is used to obtain confinement of a plasma contained in a good conductor vessel. The confinement in this scheme is supported by the magnetic forces. The Lawson criterion for a DT plasma might be achieved for number density n = 5*10 21 cm -3 and confinement time τ= 20 ns. The laser and plasma parameters required to obtain an energetic gain are calculated. Experiments and preliminary calculations were performed to study the feasibility of the above scheme. Measurements of the axial magnetic field induced by circularly polarized laser light, the so called inverse Faraday effect, and of the absorption of circularly polarized laser light in plasma, are reported. The experiments were performed with a circularly polarized Nd:YAG laser, having a wavelength of 1.06 τm and a pulse duration of 7 ns, in a range of irradiances from 10 9 to 10 14 W/cm 2 . Axial magnetic fields from 500 Gauss to 2 megagauss were measured. Up to 5*10 13 W/cm 3 the results are in agreement with a nonlinear model of the inverse Faraday effect dominated by the ponderomotive force. For the laser irradiance studied here, 9*10 13 - 2.5*10 14 W/cm 2 , the absorption of circularly polarized light was 14% higher relative to the absorption of linear polarized light

  1. Analytical Solutions of Temporal Evolution of Populations in Optically-Pumped Atoms with Circularly Polarized Light

    Directory of Open Access Journals (Sweden)

    Heung-Ryoul Noh

    2016-03-01

    Full Text Available We present an analytical calculation of temporal evolution of populations for optically pumped atoms under the influence of weak, circularly polarized light. The differential equations for the populations of magnetic sublevels in the excited state, derived from rate equations, are expressed in the form of inhomogeneous second-order differential equations with constant coefficients. We present a general method of analytically solving these differential equations, and obtain explicit analytical forms of the populations of the ground state at the lowest order in the saturation parameter. The obtained populations can be used to calculate lineshapes in various laser spectroscopies, considering transit time relaxation.

  2. In-service light path PMD (polarization mode dispersion) monitoring by PMD compensation.

    Science.gov (United States)

    Yao, X Steve; Chen, Xiaojun; Xia, T J; Wellbrock, Glenn; Chen, David; Peterson, Daniel; Zhang, Paul; Belisle, Ansel; Dong, Lei; Yu, Tao

    2010-12-20

    We describe a novel method of measuring PMD (polarization mode dispersion) of an in-service DWDM system by PMD compensation. We successfully demonstrate the method in a 1500-km ultra-long haul DWDM test bed. We further verify the feasibility of the method for in-service light path PMD monitoring in a field trial in a revenue-generating route in Verizon Network, and obtain an accurate PMD value without impacting live network traffic. The discrepancy between the measured and expected PMD values is less than 6% for all cases tested.

  3. Influence of refraction of p-polarized light on photoemission from metallic surface states

    International Nuclear Information System (INIS)

    Bagchi, A.; Barrera, R.G.

    1979-01-01

    The refraction of p-polarized light at a metal surface leads, under certain circumstances, to a large peak in the spatial distribution of the normal component of the electric field near the surface. The origin of this peak is explained both in terms of a classical correspondence and in terms of a theory based on the non-local dielectric response of the metal surface. The significance of the large magnitude and rapid variation of the surface electric field in exciting photoelectrons from surface states is discussed [pt

  4. Light-free magnetic resonance force microscopy for studies of electron spin polarized systems

    International Nuclear Information System (INIS)

    Pelekhov, Denis V.; Selcu, Camelia; Banerjee, Palash; Chung Fong, Kin; Chris Hammel, P.; Bhaskaran, Harish; Schwab, Keith

    2005-01-01

    Magnetic resonance force microscopy is a scanned probe technique capable of three-dimensional magnetic resonance imaging. Its excellent sensitivity opens the possibility for magnetic resonance studies of spin accumulation resulting from the injection of spin polarized currents into a para-magnetic collector. The method is based on mechanical detection of magnetic resonance which requires low noise detection of cantilever displacement; so far, this has been accomplished using optical interferometry. This is undesirable for experiments on doped silicon, where the presence of light is known to enhance spin relaxation rates. We report a non-optical displacement detection scheme based on sensitive microwave capacitive readout

  5. In situ light spectroscopy in the environmental transmission electron microscope (ETEM)

    DEFF Research Database (Denmark)

    Cavalca, Filippo; Langhammer, C.; Pedersen, Thomas

    2012-01-01

    is often recorded on a limited portion of the sample. Being able to probe the sample with INPS and ETEM at the same time allows parallel investigation at the local and macro scale, as well as aids the assessment of beam effects. A dedicated custom TEM specimen holder containing two optical fibers, five...... electrical contacts, a fixed miniaturized optical bench for light handling and a heating element (Fig. 1) has been designed. A system of pre-aligned mirrors and a MEMS heater are implemented in the holder. The system is primarily designed for use in combination with LSPR spectroscopy, but it is flexible...... and can be employed with a variety of other methods that require light input and/or output. The two fibers can be used as parallel light inlets to activate a photoinduced reaction, e.g. photoinduced reduction of particles or nanoparticle photodeposition [7]. Alternatively, both fibers can be used...

  6. Light-Induced Reduction of Cuprous Oxide in an Environmental Transmission Electron Microscope

    DEFF Research Database (Denmark)

    Cavalca, Filippo Carlo; Laursen, Anders Bo; Wagner, Jakob Birkedal

    2013-01-01

    Photocatalysts for solar fuel production are subject to intensive investigation as they constitute one viable route for solar energy harvesting. Cuprous oxide (Cu2O) is a working photocatalyst for hydrogen evolution but it photocorrodes upon light illumination in an aqueous environment. Environme......Photocatalysts for solar fuel production are subject to intensive investigation as they constitute one viable route for solar energy harvesting. Cuprous oxide (Cu2O) is a working photocatalyst for hydrogen evolution but it photocorrodes upon light illumination in an aqueous environment....... Environmental transmission electron microscopy (ETEM) makes it possible to obtain insight into the local structure, composition and reactivity of catalysts in their working environment, which is of fundamental interest for sustainable energy research and is essential for further material optimization. Herein......, photoreduction of Cu2O is studied in situ using a dedicated TEM specimen holder for light illumination....

  7. Polarization ratio enhancement of a-plane GaN light emitting diodes by asymmetric two-dimensional photonic crystals

    International Nuclear Information System (INIS)

    Chou, Yen; Li, Hsiang-Wei; Yin, Yu-Feng; Wang, Yu-Ting; Lin, Yen-Chen; Wu, Yuh-Renn; Huang, Jian Jang; Lin, Da-Wei; Kuo, Hao-Chung

    2014-01-01

    Fabricating photonic crystals (PhCs) on GaN based non-polar light emitting diodes (LEDs) is an effective way to increase light extraction and meanwhile to preserve or improve polarization ratio. In this work, a-plane GaN LEDs with two-dimensional PhCs were demonstrated. With the E // m polarized modes (which mean the optical polarization with the electric field parallel to m-axis) as the target of diffraction, we matched E//m modes to the photonic bands and aligned E//c modes to fall within the photonic band gap. The results show stronger E//m but weaker E//c mode diffractions on both c- and m-axes. At the vertical direction, the polarization ratio is enhanced from 45.8% for the planar device to 52.3% for the LEDs with PhCs

  8. Macrophages and mast cells in dystrophic masseter muscle: a light and electron microscopic study

    DEFF Research Database (Denmark)

    Kirkeby, S; Mikkelsen, H

    1988-01-01

    Macrophages and mast cells in masseter muscle from normal and dystrophic mice were studied by light and electron microscopy. Acid phosphatase activity and FITC-dextran were used to identify and describe macrophages. Toluidine blue was used as a marker for mast cells. In dystrophic muscle, the num......Macrophages and mast cells in masseter muscle from normal and dystrophic mice were studied by light and electron microscopy. Acid phosphatase activity and FITC-dextran were used to identify and describe macrophages. Toluidine blue was used as a marker for mast cells. In dystrophic muscle...

  9. Macrophages and mast cells in dystrophic masseter muscle: a light and electron microscopic study

    DEFF Research Database (Denmark)

    Kirkeby, S; Mikkelsen, H

    1988-01-01

    Macrophages and mast cells in masseter muscle from normal and dystrophic mice were studied by light and electron microscopy. Acid phosphatase activity and FITC-dextran were used to identify and describe macrophages. Toluidine blue was used as a marker for mast cells. In dystrophic muscle...

  10. A Spin-Light Polarimeter for Multi-GeV Longitudinally Polarized Electron Beams

    Energy Technology Data Exchange (ETDEWEB)

    Mohanmurthy, Prajwal [Mississippi State University, Starkville, MS (United States); Dutta, Dipangkar [Mississippi State University, Starkville, MS (United States) and Thomas Jefferson National Accelerator Facility, Newport News, VA (United States)

    2014-02-01

    The physics program at the upgraded Jefferson Lab (JLab) and the physics program envisioned for the proposed electron-ion collider (EIC) include large efforts to search for interactions beyond the Standard Model (SM) using parity violation in electroweak interactions. These experiments require precision electron polarimetry with an uncertainty of < 0.5 %. The spin dependent Synchrotron radiation, called "spin-light," can be used to monitor the electron beam polarization. In this article we develop a conceptual design for a "spin-light" polarimeter that can be used at a high intensity, multi-GeV electron accelerator. We have also built a Geant4 based simulation for a prototype device and report some of the results from these simulations.

  11. Transfer of polarized light in planetary atmospheres basic concepts and practical methods

    CERN Document Server

    Hovenier, Joop W; Domke, Helmut

    2004-01-01

    The principal elements of the theory of polarized light transfer in planetary atmospheres are expounded in a systematic but concise way. Basic concepts and practical methods are emphasized, both for single and multiple scattering of electromagnetic radiation by molecules and particles in the atmospheres of planets in the Solar System, including the Earth, and beyond. A large part of the book is also useful for studies of light scattering by particles in comets, the interplanetary and interstellar medium, circumstellar disks, reflection nebulae, water bodies like oceans and suspensions of particles in a gas or liquid in the laboratory. Throughout the book symmetry principles, such as the reciprocity principle and the mirror symmetry principle, are employed. In this way the theory is made more transparent and easier to understand than in most papers on the subject. In addition, significant computational reductions, resulting from symmetry principles, are presented. Hundreds of references to relevant literature ...

  12. Lamp-lit bridges as dual light-traps for the night-swarming mayfly, Ephoron virgo: interaction of polarized and unpolarized light pollution.

    Science.gov (United States)

    Szaz, Denes; Horvath, Gabor; Barta, Andras; Robertson, Bruce A; Farkas, Alexandra; Egri, Adam; Tarjanyi, Nikolett; Racz, Gergely; Kriska, Gyorgy

    2015-01-01

    Ecological photopollution created by artificial night lighting can alter animal behavior and lead to population declines and biodiversity loss. Polarized light pollution is a second type of photopollution that triggers water-seeking insects to ovisposit on smooth and dark man-made objects, because they simulate the polarization signatures of natural water bodies. We document a case study of the interaction of these two forms of photopollution by conducting observations and experiments near a lamp-lit bridge over the river Danube that attracts mass swarms of the mayfly Ephoron virgo away from the river to oviposit on the asphalt road of the bridge. Millions of mayflies swarmed near bridge-lights for two weeks. We found these swarms to be composed of 99% adult females performing their upstream compensatory flight and were attracted upward toward unpolarized bridge-lamp light, and away from the horizontally polarized light trail of the river. Imaging polarimetry confirmed that the asphalt surface of the bridge was strongly and horizontally polarized, providing a supernormal ovipositional cue to Ephoron virgo, while other parts of the bridge were poor polarizers of lamplight. Collectively, we confirm that Ephoron virgo is independently attracted to both unpolarized and polarized light sources, that both types of photopollution are being produced at the bridge, and that spatial patterns of swarming and oviposition are consistent with evolved behaviors being triggered maladaptively by these two types of light pollution. We suggest solutions to bridge and lighting design that should prevent or mitigate the impacts of such scenarios in the future. The detrimental impacts of such scenarios may extend beyond Ephoron virgo.

  13. Electro-optic modulation of light propagating near the optic axis with any polarization in uniaxial crystals

    Science.gov (United States)

    Song, Zhe; Liu, Liren; Zhou, Yu; Liu, De'an; Ren, Haixia

    2006-09-01

    The electro-optic effect in uniaxial crystals for light propagating near the optic axis with any polarization has been analyzed. The passive and the electrically induced birefringences and the rotation of polarization direction in crystals have been calculated, and the conoscopic interference figures under orthogonal polariscopes for different polarizer directions have been plotted. The extinction areas caused by the rotation of polarization direction in crystals change with the polarizer direction, but the two heads of the induced optical axes do not vary, which are always on the induced principal axis with bigger refractive index. The directions of polariscopes are always extinction, and the +/-45[degree sign] directions with polarizer are always complete transmission. The conoscopic interference figures for LiNbO3 crystals have been demonstrated experimentally by rotating polariscopes directions, which accord with the theoretically calculating plots.

  14. On interstellar light polarization by diamagnetic silicate and carbon dust in the infrared

    Science.gov (United States)

    Papoular, R.

    2018-04-01

    The motion of diamagnetic dust particles in interstellar magnetic fields is studied numerically with several different sets of parameters. Two types of behaviour are observed, depending on the value of the critical number R, which is a function of the grain inertia, the magnetic susceptibility of the material and of the strength of rotation braking. If R ≤ 10, the grain ends up in a static state and perfectly aligned with the magnetic field, after a few braking times. If not, it goes on precessing and nutating about the field vector for a much longer time. Usual parameters are such that the first situation can hardly be observed. Fortunately, in the second and more likely situation, there remains a persistent partial alignment that is far from negligible, although it decreases as the field decreases and as R increases. The solution of the complete equations of motion of grains in a field helps understanding the details of this behaviour. One particular case of an ellipsoidal forsterite silicate grain is studied in detail and shown to polarize light in agreement with astronomical measurements of absolute polarization in the infrared. Phonons are shown to contribute to the progressive flattening of extinction and polarization towards long wavelengths. The measured dielectric properties of forsterite qualitatively fit the Serkowski peak in the visible.

  15. Improving the lifetime in optical microtraps by using elliptically polarized dipole light

    Science.gov (United States)

    Garcia, Sébastien; Reichel, Jakob; Long, Romain

    2018-02-01

    Tightly focused optical dipole traps induce vector light shifts ("fictitious magnetic fields") which complicate their use for single-atom trapping and manipulation. The problem can be mitigated by adding a larger, real magnetic field, but this solution is not always applicable; in particular, it precludes fast switching to a field-free configuration. Here we show that this issue can be addressed elegantly by deliberately adding a small elliptical polarization component to the dipole trap beam. In our experiments with single 87Rb atoms laser-cooled in a chopped trap, we observe improvements up to a factor of 11 of the trap lifetime compared to the standard, seemingly ideal linear polarization. This effect results from a modification of heating processes via spin-state diffusion in state-dependent trapping potentials. We develop Monte Carlo simulations of the evolution of the atom's internal and motional states and find that they agree quantitatively with the experimental data. The method is general and can be applied in all experiments where the longitudinal polarization component is non-negligible.

  16. Highly polarized light from stable ordered magnetic fields in GRB 120308A.

    Science.gov (United States)

    Mundell, C G; Kopač, D; Arnold, D M; Steele, I A; Gomboc, A; Kobayashi, S; Harrison, R M; Smith, R J; Guidorzi, C; Virgili, F J; Melandri, A; Japelj, J

    2013-12-05

    After the initial burst of γ-rays that defines a γ-ray burst (GRB), expanding ejecta collide with the circumburst medium and begin to decelerate at the onset of the afterglow, during which a forward shock travels outwards and a reverse shock propagates backwards into the oncoming collimated flow, or 'jet'. Light from the reverse shock should be highly polarized if the jet's magnetic field is globally ordered and advected from the central engine, with a position angle that is predicted to remain stable in magnetized baryonic jet models or vary randomly with time if the field is produced locally by plasma or magnetohydrodynamic instabilities. Degrees of linear polarization of P ≈ 10 per cent in the optical band have previously been detected in the early afterglow, but the lack of temporal measurements prevented definitive tests of competing jet models. Hours to days after the γ-ray burst, polarization levels are low (P GRBs contain magnetized baryonic jets with large-scale uniform fields that can survive long after the initial explosion.

  17. Bioinspired Mesoporous Chiral Nematic Graphitic Carbon Nitride Photocatalysts modulated by Polarized Light.

    Science.gov (United States)

    Lin, Wensheng; Hong, Wei; Sun, Lu; Yu, Di; Yu, Dingshan; Chen, Xudong

    2018-01-10

    Endowing materials with chirality and exploring the responses of the material under circularly polarized light (CPL) can enable further insight into the physical and chemical properties of the semiconductors to be gained, thus expanding on optoelectronic applications. Herein a bioinspired mesoporous chiral nematic graphitic carbon nitride (g-C 3 N 4 ) for efficient hydrogen evolution with polarized light modulation based on chiral nematic cellulose nanocrystal films prepared through silica templating is described. The mesoporous nematic chiral g-C 3 N 4 exhibits an ultrahigh hydrogen evolution rate of 219.9 μmol h -1 (for 20 mg catalyst), corresponding to a high enhancement factor of 55 when compared to the bulk g-C 3 N 4 under λ>420 nm irradiation. Furthermore, the chiral g-C 3 N 4 material exhibits unique photocatalytic activity modulated by CPL within the absorption region. This CPL-assisted photocatalytic regulation strategy holds great promise for a wide range of applications including optical devices, asymmetric photocatalysis, and chiral recognition/separation. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. The "Polar Light Sign" is a useful tool to detect discrete membranous supravalvular mitral stenosis.

    Science.gov (United States)

    Hertwig, Christine; Haas, Nikolaus A; Habash, Sheeraz; Hanslik, Andreas; Kececioglu, Deniz; Sandica, Eugen; Laser, Kai-Thorsten

    2015-02-01

    Mitral valve stenosis caused by a discrete supravalvular membrane is a rare congenital malformation haemodynamically leading to significant mitral valve stenosis. When the supravalvular mitral stenosis consists of a discrete supravalvular membrane adherent to the mitral valve, it is usually not clearly detectable by routine echocardiography. We report about the typical echocardiographic finding in three young patients with this rare form of a discrete membranous supravalvular stenosis caused by a membrane adherent to the mitral valve. These cases present a typical echocardiographic feature in colour Doppler generated by the pathognomonic supramitral flow acceleration. Whereas typical supravalvular mitral stenosis caused by cor triatriatum or a clearly visible supravalvular ring is easily detectable by echocardiography, a discrete supravalvular membrane adjacent to the mitral valve leaflets resembling valvular mitral stenosis is difficult to differentiate by routine echocardiography. In our opinion, this colour phenomenon does resemble the visual impression of polar lights in the northern hemisphere; owing to its typical appearance, it may therefore be named as "Polar Light Sign". This phenomenon may help to detect this anatomical entity by echocardiography in time and therefore improve the prognosis for repair.

  19. A customized light sheet microscope to measure spatio-temporal protein dynamics in small model organisms.

    Science.gov (United States)

    Rieckher, Matthias; Kyparissidis-Kokkinidis, Ilias; Zacharopoulos, Athanasios; Kourmoulakis, Georgios; Tavernarakis, Nektarios; Ripoll, Jorge; Zacharakis, Giannis

    2015-01-01

    We describe a customizable and cost-effective light sheet microscopy (LSM) platform for rapid three-dimensional imaging of protein dynamics in small model organisms. The system is designed for high acquisition speeds and enables extended time-lapse in vivo experiments when using fluorescently labeled specimens. We demonstrate the capability of the setup to monitor gene expression and protein localization during ageing and upon starvation stress in longitudinal studies in individual or small groups of adult Caenorhabditis elegans nematodes. The system is equipped to readily perform fluorescence recovery after photobleaching (FRAP), which allows monitoring protein recovery and distribution under low photobleaching conditions. Our imaging platform is designed to easily switch between light sheet microscopy and optical projection tomography (OPT) modalities. The setup permits monitoring of spatio-temporal expression and localization of ageing biomarkers of subcellular size and can be conveniently adapted to image a wide range of small model organisms and tissue samples.

  20. Microscopic approach to the theory of light nuclei and to simple nuclear reactions

    International Nuclear Information System (INIS)

    Baz', L.I.; Filippov, G.F.

    1976-01-01

    The results of calculations for the properties of light nuclei and simple nuclear reactions using the Schrodinger multinucleon equation involving the realistic nucleon-nucleon interaction are reviewed. It is noted that the theory for the A(<=)4 nuclei is practically complete at present. The reasons for the good agreement between the theoretical and experimental cross sections of nuclear reactions are given. The programme of a correct separation of the nuclear collective degree of freedom are discussed in detail

  1. Joule heating and spin-transfer torque investigated on the atomic scale using a spin-polarized scanning tunneling microscope.

    Science.gov (United States)

    Krause, S; Herzog, G; Schlenhoff, A; Sonntag, A; Wiesendanger, R

    2011-10-28

    The influence of a high spin-polarized tunnel current onto the switching behavior of a superparamagnetic nanoisland on a nonmagnetic substrate is investigated by means of spin-polarized scanning tunneling microscopy. A detailed lifetime analysis allows for a quantification of the effective temperature rise of the nanoisland and the modification of the activation energy barrier for magnetization reversal, thereby using the nanoisland as a local thermometer and spin-transfer torque analyzer. Both the Joule heating and spin-transfer torque are found to scale linearly with the tunnel current. The results are compared to experiments performed on lithographically fabricated magneto-tunnel junctions, revealing a very high spin-transfer torque switching efficiency in our experiments.

  2. Microscopical advances in assisted reproduction.

    Science.gov (United States)

    Baccetti, B

    2004-01-01

    In a series of papers carried out by this laboratory it was demonstrated that the quality of sterile males sperm, assessed submicroscopically and mathematically, is closely correlated with the success of the various procedures of assisted reproduction. If we attempt to select hypothetically optimal spermatozoa destined to the ICSI by light inverted microscopy, a considerable amount of ultrastructural information is lost and our selection is merely based on the motility. In this study we apply polarization microscopy to the ICSI technique, introducing polarizing and analyzing lenses in an inverted microscope model, operating in a transparent container. The retardation of the birefringence in the various organelles is evaluated by compensators, and the images are transmitted to a video system, and stored in a computer. Spermatozoa are maintained alive and perfectly motile in this polarizing inverted microscope, and the character of the birefringence is the same as in fixed and sectioned biological material examined by polarization microscopy. The birefringence of the sperm structures allows a sperm analysis closer to TEM than to phase contrast light microscopy analysis.

  3. Light and electron microscopic study on complex carbohydrates in the testis of Salamandra salamandra L. (Amphibia, Urodela).

    Science.gov (United States)

    Schindelmeiser, J

    1986-01-01

    The distribution of complex carbohydrates was studied in the testis of the European fire salamander, Salamandra salamandra, by light- and electron-microscopic methods. The basal laminae and fibrous structures in the connective tissue between the lobules are PAS-positive. After alcianblue staining (at pH = 2.8), acid mucopolysaccharides could be demonstrated in steroid hormone-producing cells in the interstitial tissue between lobules containing spermatids, spermatozoa, and lobules after spermiation, as well as in most of the Sertoli cells in lobules after spermiation. In all spermatogenic stages from secondary spermatocytes to mature sperms, dictyosome-like structures and flat vesicles showed a distinct contrast enhancement, as did parts of the acrosome after treatment with the phosphotungstic acid-chromic acid method for electron microscopy.

  4. A light-sheet microscope compatible with mobile devices for label-free intracellular imaging and biosensing.

    Science.gov (United States)

    Wu, Tsung-Feng; Yen, Tony Minghung; Han, Yuanyuan; Chiu, Yu-Jui; Lin, Eason Y-S; Lo, Yu-Hwa

    2014-09-07

    The inner structure, especially the nuclear structure, of cells carries valuable information about disease and health conditions of a person. Here we demonstrate a label-free technique to enable direct observations and measurements of the size, shape and morphology of the cell nucleus. With a microfabricated lens and a commercial CMOS imager, we form a scanning light-sheet microscope to produce a dark-field optical scattering image of the cell nucleus that overlays with the bright-field image produced in a separate regime of the same CMOS sensor. We have used the device to detect nuclear features that characterize the life cycle of cells and have used the nucleus volume as a new parameter for cell classification. The device can be developed into a portable, low-cost, point-of-care device leveraging the capabilities of the CMOS imagers to be pervasive in mobile electronics.

  5. Light and electron microscopic features of eperythrozoon-like parasites in a North American opossum (Didelphis virginiana).

    Science.gov (United States)

    Messick, J B; Berent, L M; Ehrhart, E J; Wasmer, C C

    2000-06-01

    Epierythrocytic parasites associated with a severe anemic episode have not been previously reported in the opossum. A Wright-Giemsa-stained peripheral blood smear from an anemic North American opossum (Didelphis virginiana) revealed numerous organisms attached to red blood cells either singularly or in chains. Ring forms of the organism were common and could be found free in the plasma. Electron microscopy revealed that these organisms were attached to the intact plasma membrane in depressions on the surface of red blood cells. Delicate fibrils between the organism and adjacent membrane were observed. The organisms were round to oval with a diameter of 300-750 nm and were enclosed by a single limiting membrane. The light and electron microscopic features of these epierythrocytic organisms are similar to those reported for Eperythrozoon and Haemobartonella species.

  6. Light and scanning electron microscopic studies on the esophageal spines in the Pacific ridley turtle, Lepidochelys olivacea.

    Science.gov (United States)

    Yoshie, S; Honma, Y

    1976-02-01

    The peculairly specialized esophagus of the Pacific ridley turtle, Lepidochelys olivacea, was described by light and scanning electron microscopic studies. The esophagus is lined by a stratified squamous epithelium with remarkable keratinization, and its major part forms a number of large spines which have been called "pharyngeal teeth." The epithelium consists of three strate: stratum germinativum, stratum spinosum and stratum corneum. The surface of the spine is covered by a scaly keratin of possibly sloughing cells, and the cornified layer on the spine is very thick (more than 100 mu), reaching 3 to 7 times the depth of the corresponding layer in other parts. This peculiar structure in the marine turtle without toothed jaws prabably is used for breaking food into small pieces.

  7. Scanning Electron Microscopic Evaluation of Root Canal Surfaces Prepared with LightSpeed & Endowave Rotary System.

    Science.gov (United States)

    B S, Hema; Chandu, G S; Shiraguppi, Vijayakumar L

    2014-12-01

    The purpose of this in vitro study was to evaluate and compare the cleaning efficiency on root canal surfaces prepared with LightSpeed and Endowave rotary instruments. A total of 30 freshly extracted human mandibular premolars were subjected for the study. They were divided into two groups, each group consisting of 15 teeth. Group 1: The canals were prepared with LightSpeed system. Group 2: Endowave rotary system. All the groups were prepared according to manufacturer's recommendation, using 5.25% sodium hypochlorite and 17% EDTA (dent wash, prime dent) alternately as an irrigants. Crowns of each tooth were removed with diamond disks at the level of cement enamel junction. Canal length was determined by placing a size 10 K-file. The working length was 0.5 mm short of canal length. Two longitudinal grooves were prepared on the lingual and buccal surfaces of each root to facilitate vertical splitting with a chisel after canal instrumentation. The sections were then observed under SEM for presence or absence of debris and smear layer and the photographs were taken at coronal, middle and apical 1/3 with a magnification of 200 X and 1000X respectively. The scores recorded were statistically analysed using one-way-ANOVA and Mann- Whitney test. There was statistically significant difference between two groups. All groups resulted in significantly more debris and smear layer in the apical 1/3 of the canal, compared to coronal and middle 1/3 (p, <0.01). The study demonstrated that, LightSpeed instrumentation removed debris and smear layer more effectively on root canal surface than compared to Endowave instrument.

  8. In vivo light-microscopic documentation for primary calcification processes in the hermatypic coral Stylophora pistillata.

    Science.gov (United States)

    Raz-Bahat, Michal; Erez, Jonathan; Rinkevich, Baruch

    2006-08-01

    Skeletogenesis in the hermatypic coral Stylophora pistillata was studied by using the lateral skeleton preparative (LSP) assay, viz., a coral nubbin attached to a glass coverslip glued to the bottom of a Petri dish. Observations on tissue and skeletal growth were made by polarized microscopy and by using vital staining. The horizontal distal tissue edges developed thin transparent extensions of ectodermal and calicoblastic layers only. Four stages (I-IV) of skeletogenesis were observed at these edges, underneath the newly developed tissue. In stage I, a thin clear layer of coral tissue advanced 3-40 microm beyond the existing LSP peripheral zone, revealing no sign of spiculae deposition. At stage II, primary fusiform crystals (1 microm each) were deposited, forming a primary discontinuous skeletal front 5-30 microm away from the previously deposited skeleton. During stage III, needle-like crystals appeared, covering the primary fusiform crystals. Stage IV involved further lengthening of the needle-like crystals, a process that resulted in occlusion of the spaces between adjacent crystals. Calcification stages I-III developed within hours, whereas stage IV was completed in several days to weeks. Two basic skeletal structures, "scattered" and "laminar" skeletons, were formed, integrating the growth patterns of the needle-like crystals. High variation was recorded in the expression of the four calcification stages, either between different locations along a single LSP or between different preparations observed at the same diurnal time. All four skeletogenesis stages took place during both day and night periods, indicating that an intrinsic process controls S. pistillata calcification.

  9. Imaging, microscopic analysis, and modeling of a CdTe module degraded by heat and light

    Energy Technology Data Exchange (ETDEWEB)

    Johnston, Steve; Albin, David; Hacke, Peter; Harvey, Steven P.; Moutinho, Helio; Jiang, Chun-Sheng; Xiao, Chuanxiao; Parikh, Anuja; Nardone, Marco; Al-Jassim, Mowafak; Metzger, Wyatt K.

    2018-05-01

    Photoluminescence (PL), electroluminescence (EL), and dark lock-in thermography are collected during stressing of a CdTe module under one-Sun light at an elevated temperature of 100 degrees C. The PL imaging system is simple and economical. The PL images show differing degrees of degradation across the module and are less sensitive to effects of shunting and resistance that appear on the EL images. Regions of varying degradation are chosen based on avoiding pre-existing shunt defects. These regions are evaluated using time-of-flight secondary ion-mass spectrometry and Kelvin probe force microscopy. Reduced PL intensity correlates to increased Cu concentration at the front interface. Numerical modeling and measurements agree that the increased Cu concentration at the junction also correlates to a reduced space charge region.

  10. The optical fiber tip: an inherently light-coupled microscopic platform for micro- and nanotechnologies.

    Science.gov (United States)

    Kostovski, Gorgi; Stoddart, Paul R; Mitchell, Arnan

    2014-06-18

    The flat tip of an optical fiber is a unique and unconventional platform for micro and nanotechnologies. The small cross-section and large aspect ratio of the fiber provide an inherently light-coupled substrate that is uniquely suited to remote, in vivo and in situ applications. However, these same characteristics challenge established fabrication technologies, which are best suited to large planar substrates. This review presents a broad overview of strategies for patterning the flat tip of an optical fiber. Techniques discussed include self-assembly, numerous lithographies, through-fiber patterning, hybrid techniques, and strategies for mass manufacture, while the diverse applications are discussed in context throughout. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. Detection of Calcium Crystals in Knee Osteoarthritis Synovial Fluid: A Comparison Between Polarized Light and Scanning Electron Microscopy.

    Science.gov (United States)

    Frallonardo, Paola; Oliviero, Francesca; Peruzzo, Luca; Tauro, Leonardo; Scanu, Anna; Galozzi, Paola; Ramonda, Roberta; Punzi, Leonardo

    2016-10-01

    The identification of calcium crystals in synovial fluid (SF) of patients with osteoarthritis (OA) represents an important step in understanding the role of these crystals in synovial inflammation and disease progression. This study aimed to investigate the presence of calcium pyrophosphate (CPP) and basic calcium phosphate (BCP) crystals in SF collected from patients with symptomatic knee OA by scanning electron microscopy (SEM) coupled to x-ray energy dispersive spectroscopy, compensated polarized light microscopy (CPLM), and alizarin red staining. Seventy-four patients with knee OA were included in the study. Synovial fluid samples were collected after arthrocentesis and examined under CPLM for the assessment of CPP crystals. Basic calcium phosphate crystals were evaluated by alizarin red staining. All the samples were examined by SEM. The concordance between the 2 techniques was evaluated by Cohen κ agreement coefficient. Calcium pyrophosphate and BCP crystals were found, respectively, in 23 (31.1%) and 13 (17.5%) of 74 OA SFs by SEM analysis. Calcium pyrophosphate crystals were identified in 23 (31.1%) of 74 samples by CPLM, whereas BCP crystals were suspected in 27 (36.4%) of 74 samples. According to κ coefficient, the concordance between CPLM and SEM was 0.83 for CPP, and that between alizarin red and SEM was 0.68 for BCP. The results of our study showed a high level of concordance between the 2 microscope techniques as regards CPP crystal identification and a lower agreement for BCP crystals. Although this finding highlights the difficulty in identifying BCP crystals by alizarin red staining, the use of SEM remains unsuitable to apply in the clinical setting. Because of the in vitro inflammatory effect of BCP crystals, further work on their analysis in SF could provide important information about the OA process.

  12. Polarized angular dependent light scattering from plasmonic nanoparticles: Modeling, measurements, and biomedical applications

    Science.gov (United States)

    Fu, Kun

    Several significant applications have been realized for light scattering in biomedical imaging. In order to improve imaging results with light scattering-based techniques, a variety of nanoparticles have been investigated as contrast agents, including gold nanoshells. As a method for studying the optical properties of plasmonic gold nanoparticles used as contrast agents for molecular imaging, we developed an automated goniometer instrumentation system. This system, which allows us to specifically study polarized angular-dependent light scattering of plasmonic nanoparticles, allowed us to perform a series of theoretical and experimental step-wise studies. The basic optical properties of the following gold nanoparticles were progressively investigated: (1) bare nanoshells at multipolar plasmonic resonances, (2) nanoshells with PEG modifications, (3) surface-textured nanoshells and (4) immunotargeted nanoshells (nanoshell-antibody bioconjugates) for cancer imaging. Based on the results from these studies, a new technique was developed to quantitatively measure the number of immunotargeted nanoparticles that bind to HER2-positive SKBR3 human breast cancer cells. Preliminary studies of determining the minimal incubation time of immunotargeted nanoshells with SKBR3 cells were also carried out to evaluate the potential clinical application of using gold nanoshells intraoperatively. We, therefore, anticipate that our findings will provide the theoretical groundwork required for further studies aimed at optimizing the application of plasmonic nanoparticles in scattering-based optical imaging techniques.

  13. The effect of polarized polychromatic noncoherent light (bioptron) therapy on patients with carpal tunnel syndrome.

    Science.gov (United States)

    Raeissadat, Seyed Ahmad; Rayegani, Seyed Mansoor; Rezaei, Sajad; Sedighipour, Leyla; Bahrami, Mohammad Hasan; Eliaspour, Dariush; Karimzadeh, Afshin

    2014-01-01

    To study the effects of Polarized Polychromatic Noncoherent Light (Bioptron) therapy on patients with carpal tunnel syndrome (CTS). This study was designed as a randomized clinical trial. Forty four patients with mild or moderate CTS (confirmed by clinical and electrodiagnostic studies) were assigned randomly into two groups (intervention and control goups). At the beginning of the study, both groups received wrist splinting for 8 weeks. Bioptron light was applied for the intervention group (eight sessions, for 3/weeks). Bioptron was applied perpendicularly to the wrist from a 10 centimeter sdistance. Pain severity and electrodiagnostic measurements were compared from before to 8 weeks after initiating each treatment. Eight weeks after starting the treatments, the mean of pain severity based on Visual Analogue Scale (VAS) scores decreased significantly in both groups. Median Sensory Nerve Action Potential (SNAP) latency decreased significantly in both groups. However, other electrophysiological findings (median Compound Motor Action Potential (CMAP) latency and amplitude, also SNAP amplitude) did not change after the therapy in both groups. There was no meaningful difference between two groups regarding the changes in the pain severity. Bioptron with the above mentioned parameters led to therapeutic effects equal to splinting alone in patients with carpal tunnel syndrome. However, applying Bioptron with different therapeutic protocols and light parameters other than used in this study, perhaps longer duration of therapy and long term assessment may reveal different results favoring Bioptron therapy.

  14. Degrees of polarization of reflected light eliciting polarotaxis in dragonflies (Odonata), mayflies (Ephemeroptera) and tabanid flies (Tabanidae).

    Science.gov (United States)

    Kriska, György; Bernáth, Balázs; Farkas, Róbert; Horváth, Gábor

    2009-12-01

    With few exceptions insects whose larvae develop in freshwater possess positive polarotaxis, i.e., are attracted to sources of horizontally polarized light, because they detect water by means of the horizontal polarization of light reflected from the water surface. These insects can be deceived by artificial surfaces (e.g. oil lakes, asphalt roads, black plastic sheets, dark-coloured cars, black gravestones, dark glass surfaces, solar panels) reflecting highly and horizontally polarized light. Apart from the surface characteristics, the extent of such a 'polarized light pollution' depends on the illumination conditions, direction of view, and the threshold p* of polarization sensitivity of a given aquatic insect species. p* means the minimum degree of linear polarization p of reflected light that can elicit positive polarotaxis from a given insect species. Earlier there were no quantitative data on p* in aquatic insects. The aim of this work is to provide such data. Using imaging polarimetry in the red, green and blue parts of the spectrum, in multiple-choice field experiments we measured the threshold p* of ventral polarization sensitivity in mayflies, dragonflies and tabanid flies, the positive polarotaxis of which has been shown earlier. In the blue (450nm) spectral range, for example, we obtained the following thresholds: dragonflies: Enallagma cyathigerum (0%

  15. MICROSCOPE Mission: First Constraints on the Violation of the Weak Equivalence Principle by a Light Scalar Dilaton

    Science.gov (United States)

    Bergé, Joel; Brax, Philippe; Métris, Gilles; Pernot-Borràs, Martin; Touboul, Pierre; Uzan, Jean-Philippe

    2018-04-01

    The existence of a light or massive scalar field with a coupling to matter weaker than gravitational strength is a possible source of violation of the weak equivalence principle. We use the first results on the Eötvös parameter by the MICROSCOPE experiment to set new constraints on such scalar fields. For a massive scalar field of mass smaller than 10-12 eV (i.e., range larger than a few 1 05 m ), we improve existing constraints by one order of magnitude to |α |<10-11 if the scalar field couples to the baryon number and to |α |<10-12 if the scalar field couples to the difference between the baryon and the lepton numbers. We also consider a model describing the coupling of a generic dilaton to the standard matter fields with five parameters, for a light field: We find that, for masses smaller than 10-12 eV , the constraints on the dilaton coupling parameters are improved by one order of magnitude compared to previous equivalence principle tests.

  16. Proceedings of study meeting on microscopic and phenomenological research of interaction for light heavy-ion systems

    International Nuclear Information System (INIS)

    1991-06-01

    The Research Center for Nuclear Physics study meeting 'Microscopic and phenomenological research of interaction for light heavy-ion systems was held on March 7-9, 1990 as the study meeting in the second half of 1990, and 25 researchers took part in it. As the background of holding this study meeting, the fact that recently the rainbow scattering due to nuclear force was discovered experimentally in 16 O- 16 O system, and phenomenologically it was explained only by deep inter-nucleus potential. This should be evaluated as an important foothold for the research on the interaction for light heavy-ion systems and nuclear reaction mechanism. Accordingly, most of the papers presented this time were those related to the inter-nucleus potential and nuclear reaction mechanism. Also the development of theoretical analysis method was carried out and reported. Further, recently the experimental study on the structure and reaction of the neutron rich nucleus has advanced, and the theoretical research related to this topic was reported. (K.I.)

  17. Polarized light curves illuminate wind geometries in Wolf-Rayet binary stars

    Science.gov (United States)

    Hoffman, Jennifer L.; Fullard, Andrew G.; Nordsieck, Kenneth H.

    2018-01-01

    Although the majority of massive stars are affected by a companion during the course of their evolution, the role of binary systems in creating supernova and GRB progenitors is not well understood. Binaries containing Wolf-Rayet stars are particularly interesting because they may provide a mechanism for producing the rapid rotation necessary for GRB formation. However, constraining the evolutionary fate of a Wolf-Rayet binary system requires characterizing its mass loss and mass transfer, a difficult prospect in systems whose colliding winds obscure the stars and produce complicated spectral signatures.The technique of spectropolarimetry is ideally suited to studying WR binary systems because it can disentangle spectral components that take different scattering paths through a complex distribution of circumstellar material. In particular, comparing the polarization behavior as a function of orbital phase of the continuum (which arises from the stars) with that of the emission lines (which arise from the interaction region) can provide a detailed view of the wind structures in a WR+O binary and constrain the system’s mass loss and mass transfer properties.We present new continuum and line polarization curves for three WR+O binaries (WR 30, WR 47, and WR 113) obtained with the RSS spectropolarimeter at the Southern African Large Telescope. We use radiative transfer simulations to analyze the polarization curves, and discuss our interpretations in light of current models for V444 Cygni, a well-studied related binary system. Accurately characterizing the structures of the wind collision regions in these massive binaries is key to understanding their evolution and properly accounting for their contribution to the supernova (and possible GRB) progenitor population.

  18. Light and electron microscopic analysis of tattoos treated by Q-switched ruby laser

    Energy Technology Data Exchange (ETDEWEB)

    Taylor, C.R.; Anderson, R.R.; Gange, R.W.; Michaud, N.A.; Flotte, T.J. (Massachusetts General Hospital, Boston (USA))

    1991-07-01

    Short-pulse laser exposures can be used to alter pigmented structures in tissue by selective photothermolysis. Potential mechanisms of human tattoo pigment lightening with Q-switched ruby laser were explored by light and electron microscopy. Significant variation existed between and within tattoos. Electron microscopy of untreated tattoos revealed membrane-bound pigment granules, predominantly within fibroblasts and macrophages, and occasionally in mast cells. These granules contained pigment particles ranging from 2-in diameter. Immediately after exposure, dose-related injury was observed in cells containing pigment. Some pigment particles were smaller and lamellated. At fluences greater than or equal to 3 J/cm2, dermal vacuoles and homogenization of collagen bundles immediately adjacent to extracellular pigment were occasionally observed. A brisk neutrophilic infiltrate was apparent by 24 h. Eleven days later, the pigment was again intracellular. Half of the biopsies at 150 d revealed a mild persistent lymphocytic infiltrate. There was no fibrosis except for one case of clinical scarring. These findings confirm that short-pulse radiation can be used to selectively disrupt cells containing tattoo pigments. The physial alteration of pigment granules, redistribution, and elimination appear to account for clinical lightening of the tattoos.

  19. A New Code SORD for Simulation of Polarized Light Scattering in the Earth Atmosphere

    Science.gov (United States)

    Korkin, Sergey; Lyapustin, Alexei; Sinyuk, Aliaksandr; Holben, Brent

    2016-01-01

    We report a new publicly available radiative transfer (RT) code for numerical simulation of polarized light scattering in plane-parallel atmosphere of the Earth. Using 44 benchmark tests, we prove high accuracy of the new RT code, SORD (Successive ORDers of scattering). We describe capabilities of SORD and show run time for each test on two different machines. At present, SORD is supposed to work as part of the Aerosol Robotic NETwork (AERONET) inversion algorithm. For natural integration with the AERONET software, SORD is coded in Fortran 90/95. The code is available by email request from the corresponding (first) author or from ftp://climate1.gsfc.nasa.gov/skorkin/SORD/.

  20. Circularly polarized reflection from the scarab beetle Chalcothea smaragdina: light scattering by a dual photonic structure.

    Science.gov (United States)

    McDonald, Luke T; Finlayson, Ewan D; Wilts, Bodo D; Vukusic, Pete

    2017-08-06

    Helicoidal architectures comprising various polysaccharides, such as chitin and cellulose, have been reported in biological systems. In some cases, these architectures exhibit stunning optical properties analogous to ordered cholesteric liquid crystal phases. In this work, we characterize the circularly polarized reflectance and optical scattering from the cuticle of the beetle Chalcothea smaragdina (Coleoptera: Scarabaeidae: Cetoniinae) using optical experiments, simulations and structural analysis. The selective reflection of left-handed circularly polarized light is attributed to a Bouligand-type helicoidal morphology within the beetle's exocuticle. Using electron microscopy to inform electromagnetic simulations of this anisotropic stratified medium, the inextricable connection between the colour appearance of C. smaragdina and the periodicity of its helicoidal rotation is shown. A close agreement between the model and the measured reflectance spectra is obtained. In addition, the elytral surface of C. smaragdina possesses a blazed diffraction grating-like surface structure, which affects the diffuse appearance of the beetle's reflected colour, and therefore potentially enhances crypsis among the dense foliage of its rainforest habitat.

  1. A dead-zone free ⁴He atomic magnetometer with intensity-modulated linearly polarized light and a liquid crystal polarization rotator.

    Science.gov (United States)

    Wu, T; Peng, X; Lin, Z; Guo, H

    2015-10-01

    We demonstrate an all-optical (4)He atomic magnetometer experimental scheme based on an original Bell-Bloom configuration. A single intensity-modulated linearly polarized laser beam is used both for generating spin polarization within a single (4)He vapor and probing the spin precessing under a static magnetic field. The transmitted light signal from the vapor is then phase-sensitively detected at the modulation frequency and its harmonics, which lead to the atomic magnetic resonance signals. Based on this structure, a liquid crystal is added in our magnetometer system and constitutes a polarization rotator. By controlling the voltage applied on the liquid crystal, the light linear polarization vector can be kept perpendicular with the ambient magnetic field direction, which in turn provides the maximum resonance signal amplitude. Moreover, the system exhibits a magnetic-field noise floor of about 2pT/√Hz, which is not degraded due to the presence of the liquid crystal and varying magnetic field direction. The experiment results prove that our method can eliminate the dead-zone effect, improve the system spatial isotropy, and thus be suitable in mobile applications.

  2. Study of Photosensitivity as a Function of Polarization for UV-Light in Optical Fibre using Blue Luminescence

    DEFF Research Database (Denmark)

    Sørensen, Henrik Rokkjær; Canning, John; Gregersen, Niels

    2005-01-01

    The difference in photosensitivity between S and P polarized light is investigated. Polarisation dependent scattering at the fibre-air surface and UV-induced alignment are shown to be of no importance, but indications of radially parasitic defects sites are found.......The difference in photosensitivity between S and P polarized light is investigated. Polarisation dependent scattering at the fibre-air surface and UV-induced alignment are shown to be of no importance, but indications of radially parasitic defects sites are found....

  3. Light and electron microscopic study of mature spermatozoa from White Pekin duck (Anas platyrhynchos): an ultrastructural and molecular analysis.

    Science.gov (United States)

    Majhi, Rakesh Kumar; Kumar, Ashutosh; Yadav, Manoj; Kumar, Pradeep; Maity, Apratim; Giri, Sunil C; Goswami, Chandan

    2016-03-01

    The morphology, ultrastructure, and functions of mature avian spermatozoa have been of immense commercial and scientific interest for several reasons. This is mainly important in case of birds in poultry production, conservation, and in the use of sperm morphometry as phylogenetic evidence. Avian spermatozoa share complex or no correlation of sperm morphometry with respect to testis and/or body size as described before. In this work, we have isolated mature spermatozoa from White Pekin duck (Anas platyrhynchos) by non-invasive methods and performed several immunostaining analysis as well as cytochemical analysis using electron and light microscopes. Here, we report the presence of different post-translationally modified tubulin such as tyrosinated-, detyrosinated-, acetylated-, polyglutamylated-, and glycylated-tubulin in specific regions of the mature spermatozoa. By using field-emission scanning electron microscope, we confirm the presence of acrosome-like structure at the tip of the sperm head. However, this structure remains non-reactive to common lectins such as Peanut Agglutinin (PNA) and cholesterol-sensitive dyes such as Filipin. We report that this acrosomal structure is primarily made of lipid-based structures and is resistant to 0.1% Triton X100. Confocal microscopy and super resolution structured illumination microscopy study indicates that the nucleus is bifurcated at the tip region. By using specific markers, we report that the perforatorium structure present at the tip of the spermatozoa head contains specialized organelles that is similar to atypical mitochondria. We propose that these ultrastructural and molecular parameters can be used as species-specific features. The bifurcated nucleus and presence of atypical mitochondria within this structure may be relevant for the complex mitochondrial inheritance and mitochondrial heteroplasmy observed in case of avian population. © 2016 American Society of Andrology and European Academy of Andrology.

  4. Demonstration of 5'-nucleotidase activity in unfixed cryostat sections of rat liver using a combined light- and electron-microscope procedure

    NARCIS (Netherlands)

    Song, J.; Bosch, K. S.; Tigchelaar, W.; van den Munckhof, R. J.; Schellens, J. P.; van Noorden, C. J.; Frederiks, W. M.

    1995-01-01

    In the present study a technique was developed to demonstrate 5'-nucleotidase activity in unfixed cryostat sections of rat liver at the light- and electron-microscope level using a semipermeable membrane. In order to retain the ultrastructure of the unfixed material as much as possible, incubations

  5. Polarized light transmission in ferrofluids loaded with carbon nanotubes in the presence of a uniform magnetic field

    Energy Technology Data Exchange (ETDEWEB)

    Vales-Pinzón, C., E-mail: cvales@mda.cinvestav.mx [Applied Physics Department, CINVESTAV-Unidad Mérida, Antigua carretera a Progreso km 6, A.P. 73, Cordemex, Mérida Yucatán 97310 (Mexico); Alvarado-Gil, J.J. [Applied Physics Department, CINVESTAV-Unidad Mérida, Antigua carretera a Progreso km 6, A.P. 73, Cordemex, Mérida Yucatán 97310 (Mexico); Medina-Esquivel, R. [Facultad de Ingeniería-UADY, Av. Industrias no Contaminantes por Periférico Norte, A.P. 150, Cordemex, Mérida, Yucatán (Mexico); Martínez-Torres, P. [Department of Mechanical Engineering, University of California, Riverside, 900 University Ave., Riverside, CA 92521 (United States)

    2014-11-15

    Magneto-optic phenomena in ferrofluids have been shown to be related to the formation of chain structures, due to the arrangement of the ferromagnetic particles, induced by an applied magnetic field. In this work, the effects on transmission of polarized light due to anisotropic effects induced by an external magnetic field in ferrofluids with carbon nanotubes are studied. The time response of the system presents two well defined stages, in the first one, which is very short, the fluid behaves as a polarizer. In contrast in the second stage, the effects of light transmission dominate. In this stage the transmitted light intensity grows with time and after a long time reaches a constant stable value. It is shown that these phenomena depend on the carbon nanotubes concentration as well as on the strength of the applied magnetic field. Using a simple model that considers a chain-like structure formation, it is possible to determine the rate of agglomeration of the formed structures and the attenuation coefficient of the transmitted light. The formation of nanostructures leads to variation in the transmitted light, depending on the polarization of the incident light. These magnetic nanostructures can find numerous applications in nanotechnology, optical devices and medicine. - Highlights: • Carbon nanotubes in ferrofluids favor the formation of chain-like structures. • In the presence of a magnetic field ferrofluids loaded with CNT behaves as a polarizer. • Transmitted light increases when samples are under a magnetic field then stabilizes. • Attenuation time for transmitted light and agglomeration parameters were studied.

  6. Strongly transverse-electric-polarized emission from deep ultraviolet AlGaN quantum well light emitting diodes

    Energy Technology Data Exchange (ETDEWEB)

    Reich, Christoph, E-mail: Christoph.Reich@tu-berlin.de; Guttmann, Martin; Wernicke, Tim; Mehnke, Frank; Kuhn, Christian [Institut für Festkörperphysik, Technische Universität Berlin, Hardenbergstr. 36, Berlin 10623 (Germany); Feneberg, Martin; Goldhahn, Rüdiger [Institut für Experimentelle Physik, Otto-von-Guericke-Universität, Universitätsplatz 2, Magdeburg 39106 (Germany); Rass, Jens; Kneissl, Michael [Institut für Festkörperphysik, Technische Universität Berlin, Hardenbergstr. 36, Berlin 10623 (Germany); Ferdinand-Braun-Institut, Leibniz-Institut für Höchstfrequenztechnik, Gustav-Kirchhoff-Str. 4, Berlin 12489 (Germany); Lapeyrade, Mickael; Einfeldt, Sven; Knauer, Arne; Kueller, Viola; Weyers, Markus [Ferdinand-Braun-Institut, Leibniz-Institut für Höchstfrequenztechnik, Gustav-Kirchhoff-Str. 4, Berlin 12489 (Germany)

    2015-10-05

    The optical polarization of emission from ultraviolet (UV) light emitting diodes (LEDs) based on (0001)-oriented Al{sub x}Ga{sub 1−x}N multiple quantum wells (MQWs) has been studied by simulations and electroluminescence measurements. With increasing aluminum mole fraction in the quantum well x, the in-plane intensity of transverse-electric (TE) polarized light decreases relative to that of the transverse-magnetic polarized light, attributed to a reordering of the valence bands in Al{sub x}Ga{sub 1−x}N. Using k ⋅ p theoretical model calculations, the AlGaN MQW active region design has been optimized, yielding increased TE polarization and thus higher extraction efficiency for bottom-emitting LEDs in the deep UV spectral range. Using (i) narrow quantum wells, (ii) barriers with high aluminum mole fractions, and (iii) compressive growth on patterned aluminum nitride sapphire templates, strongly TE-polarized emission was observed at wavelengths as short as 239 nm.

  7. [Sensory and electrical responses in stimulation of the macula with short-wave (407-527 nm) linear polarized light (Haidinger polarization brushes)].

    Science.gov (United States)

    Dodt, E; Tsuyama, Y; Kuba, M

    1994-04-01

    We investigated Haidinger's (1844) entoptic polarization brushes of the macula psychophysically and electrophysiologically during rotation of plane-polarized blue (projected to a polarization screen. Psychophysically the sensitivity of the brushes was highest between 470 and 490 nm, with a steep decrease at longer wavelengths. Increase of adaptive illumination (I) above 0.1 cd/m2 increased the increment threshold (delta I) of the brushes between 407 and 515 nm about equally (delta I/I = 0.9). Comparison of the action spectrum of different photoreceptors with the spectral sensitivity of Haidinger's brushes suggested synergistic contributions of blue, green and red photoreceptors. A decrease in visual acuity to 0.01 by plus lenses did not affect the light threshold of the brushes significantly, while blurring by Bangerter foils increased the threshold markedly (about eightfold at visual acuity of 0.01). Thus, the determination of threshold of Haidinger's brushes provides the means of investigating certain macular functions behind, and widely independent of, opacities of the ocular media. While no retinal potentials (ERG) were seen during rotation of the polarizer, we obtained cortical potentials (VEP) closely related to the appearance of Haidinger's brushes in response to rotation onset of blue polarized light. The potential derived from Oz+Ol+Or consisted of a phasic negative response after a peak latency of 295 +/- 34 ms (N 295). Similar responses were also obtained to medium and long wavelengths (extrinsic windmill rotation during foveal fixation at stimulus conditions closely related to Haidinger's brushes: 3 degrees field, 2 cy/rev, 2 cd/m2, contrast 0.15). Thus VEP recording permits the comparison of entoptic and extrinsic excitation of the macula.

  8. Photobiomodulation with polarized light in the treatment of cutaneous and mucosal ulcerative lesions.

    Science.gov (United States)

    Aragona, S E; Grassi, F R; Nardi, G; Lotti, J; Mereghetti, G; Canavesi, E; Equizi, E; Puccio, A M; Lotti, T

    In recent decades, regenerative medicine has achieved an important evolution at both a conceptual level and scientific production, which explains the current and future possibilities of therapy and daily clinical practice. The main aim of regenerative medicine is the complex system of repair/regeneration. The current literature on the subject demonstrates the advantage of visible light therapy for skin injuries and diseases with the photobiomodulation in which light at low energy levels modulates intra- and extra-cellular photoreceptors by molecular and cellular processes that can stimulate both anti-inflammatory mechanisms and cell proliferative response. The irradiation effects are activated soon after exposure. The anti-inflammatory action on some classes of cytokines and cells (e.g. mast cells and macrophages) is completed with the stimulation of the nitric oxide production, which has an anti-inflammatory and vasodilation action, and gives analgesic relief. Our attention focused on photobiomodulator medical device emitting polarized light. 30 patients (19 women and 11 men) were enrolled in the present study. They were treated for chronic lesions using Bioptron® Light Therapy System device. Patients were initially subjected to Bioptron® light for 20 min after cleansing of the lesion. The operating protocol provides 24 sessions: twice per week for 12 weeks. Twenty patients have been studied for symptoms, histological samples and ulcer characteristics. After 2 months, a reduction of 50% of the lesions was recorded in 18 patients (60%), while in the remaining patients a slower healing was observed. The total wound healing was achieved after 3 months in 13 patients (43%). The examined parameters of the symptom were exudation, pain and signs of infection. Results at 1 and 3 months were, Exudation: at 1 month reduction and positive modulation was observed in 16 patients (53%) and in 25 patients at 3 months; Pain: (evaluated with Vas scale), decreased in 21 patients

  9. Structural Alterations of the Glomerular Wall And Vessels in Early Stages of Diabetes Mellitus: Light and Transmission Electron Microscopic Study

    Directory of Open Access Journals (Sweden)

    Dkhil MA

    2007-01-01

    Full Text Available Objective: The capillary changes at the initial stage of diabetes may show an angioarchitecture clearly different from those of later stages and,/or very severe glomerular change. However, the onset of alterations in the early phases is unclear. This study attempts to determine the functional and structural alterations of the glomerular wall and vesicles in the early stage of diabetes.Material and Methods: Twenty-five adult rats were used in this study. They were divided into two groups: the first group of five was used as a control .The second group of 20 (the experimental group was injected intraperitoneally by a single dose of streptozotocin to induce hyperglycemia. Rats were sacrificed after ten days, two months, and four months.Five rats at two months of age with hyperglycemia were treated with insulin for eight weeks. Renal tissues were prepared by routine technique for light and transmission electron microscopic evaluation. Results: By light microscopy after ten days of induced hyperglycemia, there were no structural modifications detected either in renal glomerular fine vessels or in the glomerular basement membrane of the glomerular capillaries. After two months, there was a moderate glomerular enlargement and dilatation of glomerular capillaries, afferent, and efferent arterioles. After four months, glomerular basement membrane thickening was the only structural alteration observed. Recovery of the glomerular alterations was observed after two months of treatment with insulin. Conclusion: In early stages of diabetes mellitus in rats, there was an increase in the diameter of glomerular vessels. In later stages of the disease, the reverse was seen, but insulin treatment had a positive role in reversing these changes in the study subjects.

  10. Light microscopical structure of the excurrent ducts and distribution of spermatozoa in the Australian rodents Pseudomys australis and Notomys alexis.

    Science.gov (United States)

    Peirce, E J; Breed, W G

    1989-01-01

    The light microscopical structure of the male excurrent ducts and the distribution of spermatozoa were examined in two species of Australian rodents, the plains rat, Pseudomys australis, and the hopping mouse, Notomys alexis. In plains rats the microstructure of the ductus epididymidis and ductus deferens was similar to that of the common laboratory rodents, with the majority of the spermatozoa being found in the cauda epididymides. By contrast, in the hopping mouse, the structure of the cauda epididymidis differed significantly as the height of the epithelium and stereocilia did not decrease from the distal caput to the cauda region, and luminal diameter did not increase markedly along its length. In addition, few spermatozoa were stored in the cauda region of the tract, and as many as 60% were located in the ductus deferens, the distal portion of which displayed a highly infolded epithelium and underlying lamina propria. These differences in histological structure of the hopping mouse excurrent ducts presumably reflect divergence in function of the various regions of the tract. Although the functional implications of the present findings remain to be determined, this study demonstrates the considerable plasticity in the male excurrent ducts amongst the hydromyine rodents of Australia. Images Figs. 1-2 Fig. 3 Fig. 4 Fig. 5 Fig. 6 Fig. 7 Fig. 8 Fig. 9 Fig. 10 Fig. 11 Fig. 12 Fig. 13 Fig. 14 Fig. 15 Fig. 16 Fig. 17 Fig. 18 Fig. 19 Fig. 20 Fig. 21 Figs. 22-23 Fig. 24 Fig. 25 Fig. 26 PMID:2808117

  11. Analysis of light scattering from human breast tissue using a custom dual-optical scanning near-field optical microscope.

    Science.gov (United States)

    Kyle, Jennifer Reiber; Kyle, Michael D; Raghavan, Ravi; Budak, Gurer; Ozkan, Cengiz S; Ozkan, Mihrimah

    2011-03-01

    In this paper we introduce a custom scanning near-field optical microscope (SNOM) that simultaneously collects reflection and transmission near-field images along with topography. This dual-optical SNOM uses a bent probe, which allows for axial reflection imaging, accurate surface scanning, and easy identification of topographic artifacts. Using this novel dual-optical SNOM, we image desiccated and non-desiccated human breast epithelial tissue. By comparing the simultaneous SNOM images, we isolate the effects of tissue morphology and variations in refractive indices on the forward- and back-scattering of light from the tissue. We find that the reduction in back-scattering from tissue, relative to the glass slide, is caused by dense packing of the scattering sites in the cytoplasm (morphology) in the desiccated tissue and a thin-film of water adhering to the glass slide (refractive index) in the non-desiccated tissue sample. Our work demonstrates the potential of our customized dual-optical SNOM system for label-free tissue diagnostics. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  12. Protective effects of vitamin C on cisplatin-induced renal damage: a light and electron microscopic study.

    Science.gov (United States)

    Tarladacalisir, Yeter Topcu; Kanter, Mehmet; Uygun, Muberra

    2008-01-01

    The present study was performed to investigate whether the chronic administration of antioxidant vitamin C provided morphological protection on cisplatin-induced renal damage. Wistar albino male rats were divided into control and two experiment groups, each consisting of six rats. Cisplatin (5 mg/kg/month) was administered intravenously to the second and third group for three months. After the first application of cisplatin, vitamin C (8 mg/kg/day) to the third group was administered intramuscular for 3 months. At the end of the third month, the kidney specimens of the all groups were obtained. All of these kidney specimens were processed for light and electron microscopical examination. In the second group, most of the renal corpuscle lost their normal appearance and size, especially in the corticomedullary region. The most obvious changes were encountered in the proximal tubules. These changes were tubular dilation, thickening of basement membrane, loss of brush border, vacuolization, and swollenness of mitochondria in the proximal tubule epithelial cells. In addition, infiltration foci were observed mainly in the cortical region. In the third group, which was administered cisplatin plus vitamin C, although the structural damages and morphometric changes were lessened, mononuclear cell infiltration was still observed. This study suggests that the chronic administration of vitamin C may be of therapeutic benefit on cisplatin nephrotoxicity.

  13. The use of charge extraction by linearly increasing voltage in polar organic light-emitting diodes

    Science.gov (United States)

    Züfle, Simon; Altazin, Stéphane; Hofmann, Alexander; Jäger, Lars; Neukom, Martin T.; Schmidt, Tobias D.; Brütting, Wolfgang; Ruhstaller, Beat

    2017-05-01

    We demonstrate the application of the CELIV (charge carrier extraction by linearly increasing voltage) technique to bilayer organic light-emitting devices (OLEDs) in order to selectively determine the hole mobility in N,N0-bis(1-naphthyl)-N,N0-diphenyl-1,10-biphenyl-4,40-diamine (α-NPD). In the CELIV technique, mobile charges in the active layer are extracted by applying a negative voltage ramp, leading to a peak superimposed to the measured displacement current whose temporal position is related to the charge carrier mobility. In fully operating devices, however, bipolar carrier transport and recombination complicate the analysis of CELIV transients as well as the assignment of the extracted mobility value to one charge carrier species. This has motivated a new approach of fabricating dedicated metal-insulator-semiconductor (MIS) devices, where the extraction current contains signatures of only one charge carrier type. In this work, we show that the MIS-CELIV concept can be employed in bilayer polar OLEDs as well, which are easy to fabricate using most common electron transport layers (ETLs), like Tris-(8-hydroxyquinoline)aluminum (Alq3). Due to the macroscopic polarization of the ETL, holes are already injected into the hole transport layer below the built-in voltage and accumulate at the internal interface with the ETL. This way, by a standard CELIV experiment only holes will be extracted, allowing us to determine their mobility. The approach can be established as a powerful way of selectively measuring charge mobilities in new materials in a standard device configuration.

  14. Polarity-Tunable Host Materials and Their Applications in Thermally Activated Delayed Fluorescence Organic Light-Emitting Diodes.

    Science.gov (United States)

    Xie, Gaozhan; Chen, Dongjun; Li, Xianglong; Cai, Xinyi; Li, Yunchuan; Chen, Dongcheng; Liu, Kunkun; Zhang, Qian; Cao, Yong; Su, Shi-Jian

    2016-10-04

    A series of polarity-tunable host materials were developed based on oligocarbazoles and diphenylphosphine oxide, and their polarities can be tuned through increasing distance of acceptor and donor units. Density functional theory calculations were employed, and photoluminescence spectra in different polar solvents were measured to illustrate different polarities of these host materials. As CZPO has relatively stronger polarity, electroluminescence (EL) spectrum of solution-processed device based on 6 wt % PXZDSO2:CZPO is 7 nm red-shifted relative to that of other host materials based devices. Besides, a comparable impressive external quantum efficiency (EQE) value of 18.7% is achieved for an evaporation-processed yellow device consisting of FCZBn, which is superior to that of the device based on CBP (4,4'-dicarbazolyl-1,1'-biphenyl) (17.0%), and its efficiency roll-off is also obviously reduced, giving an EQE value as high as 16.3% at the luminance of 1000 cd/m 2 . In addition, from CZPO to FCZBn as the polarities of host materials decrease, EL spectra of solution-processed devices based on DMAC-DPS emitter blue-shift constantly from 496 to 470 nm. The current work gives a constructive approach to control EL spectra of organic light-emitting diodes with a fixed thermally activated delayed fluorescence emitter by tuning the polarities of host materials.

  15. Anisotropic contrast optical microscope.

    Science.gov (United States)

    Peev, D; Hofmann, T; Kananizadeh, N; Beeram, S; Rodriguez, E; Wimer, S; Rodenhausen, K B; Herzinger, C M; Kasputis, T; Pfaunmiller, E; Nguyen, A; Korlacki, R; Pannier, A; Li, Y; Schubert, E; Hage, D; Schubert, M

    2016-11-01

    An optical microscope is described that reveals contrast in the Mueller matrix images of a thin, transparent, or semi-transparent specimen located within an anisotropic object plane (anisotropic filter). The specimen changes the anisotropy of the filter and thereby produces contrast within the Mueller matrix images. Here we use an anisotropic filter composed of a semi-transparent, nanostructured thin film with sub-wavelength thickness placed within the object plane. The sample is illuminated as in common optical microscopy but the light is modulated in its polarization using combinations of linear polarizers and phase plate (compensator) to control and analyze the state of polarization. Direct generalized ellipsometry data analysis approaches permit extraction of fundamental Mueller matrix object plane images dispensing with the need of Fourier expansion methods. Generalized ellipsometry model approaches are used for quantitative image analyses. These images are obtained from sets of multiple images obtained under various polarizer, analyzer, and compensator settings. Up to 16 independent Mueller matrix images can be obtained, while our current setup is limited to 11 images normalized by the unpolarized intensity. We demonstrate the anisotropic contrast optical microscope by measuring lithographically defined micro-patterned anisotropic filters, and we quantify the adsorption of an organic self-assembled monolayer film onto the anisotropic filter. Comparison with an isotropic glass slide demonstrates the image enhancement obtained by our method over microscopy without the use of an anisotropic filter. In our current instrument, we estimate the limit of detection for organic volumetric mass within the object plane of ≈49 fg within ≈7 × 7 μm 2 object surface area. Compared to a quartz crystal microbalance with dissipation instrumentation, where contemporary limits require a total load of ≈500 pg for detection, the instrumentation demonstrated here improves

  16. Polarization-sensitive optical frequency domain imaging based on unpolarized light

    NARCIS (Netherlands)

    Kim, K.H.; Park, B. H.; Tu, Y.P.; Hasan, T.; Lee, B.; Li, J.; de Boer, J.F.

    2011-01-01

    Polarization-sensitive optical coherence tomography (PS-OCT) is an augmented form of OCT, providing 3D images of both tissue structure and polarization properties. We developed a new method of polarization-sensitive optical frequency domain imaging (PS-OFDI), which is based on a wavelength-swept

  17. High-speed polarized light microscopy for in situ, dynamic measurement of birefringence properties

    Science.gov (United States)

    Wu, Xianyu; Pankow, Mark; Shadow Huang, Hsiao-Ying; Peters, Kara

    2018-01-01

    A high-speed, quantitative polarized light microscopy (QPLM) instrument has been developed to monitor the optical slow axis spatial realignment during controlled medium to high strain rate experiments at acquisition rates up to 10 kHz. This high-speed QPLM instrument is implemented within a modified drop tower and demonstrated using polycarbonate specimens. By utilizing a rotating quarter wave plate and a high-speed camera, the minimum acquisition time to generate an alignment map of a birefringent specimen is 6.1 ms. A sequential analysis method allows the QPLM instrument to generate QPLM data at the high-speed camera imaging frequency 10 kHz. The obtained QPLM data is processed using a vector correlation technique to detect anomalous optical axis realignment and retardation changes throughout the loading event. The detected anomalous optical axis realignment is shown to be associated with crack initiation, propagation, and specimen failure in a dynamically loaded polycarbonate specimen. The work provides a foundation for detecting damage in biological tissues through local collagen fiber realignment and fracture during dynamic loading.

  18. Effects of Linear-Polarized Near-Infrared Light Irradiation on Chronic Pain

    Directory of Open Access Journals (Sweden)

    Dong Huang

    2012-01-01

    Full Text Available In order to study the efficacy of linear-polarized near-infrared light irradiation (LPNIR on relieving chronic pain in conjunction with nerve block (NB or local block (LB, a 3-week prospective, randomized, double-blind, controlled study was conducted to evaluate the pre- and post-therapy pain intensity. Visual analogue scales (VASs were measured in all patients before and 6 months after therapy visiting the pain clinic during the period of August 2007 to January 2008. A total of 52 patients with either shoulder periarthritis or myofascial pain syndrome or lateral epicondylitis were randomly assigned into two groups by drawing lots. Patients in Group I were treated with NB or LB plus LPNIR; Group II patients, for their part, were treated with the same procedures as in Group I, but not using LPNIR. In both groups, the pain intensity (VAS score decreased significantly immediately after therapy as compared to therapy. There was a significant difference between the test and control groups immediately after therapy (P<0.05, while no effect 6 months later. No side effects were observed. It is concluded that LPNIR is an effective and safe modality to treat various chronic pains, which has synergic effects with NB or LB.

  19. Chiral Nematic Structure of Cellulose Nanocrystal Suspensions and Films; Polarized Light and Atomic Force Microscopy

    Directory of Open Access Journals (Sweden)

    Derek G. Gray

    2015-11-01

    Full Text Available Cellulosic liquid crystalline solutions and suspensions form chiral nematic phases that show a rich variety of optical textures in the liquid crystalline state. These ordered structures may be preserved in solid films prepared by evaporation of solvent or suspending medium. Film formation from aqueous suspensions of cellulose nanocrystals (CNC was investigated by polarized light microscopy, optical profilometry and atomic force microscopy (AFM. An attempt is made to interpret qualitatively the observed textures in terms of the orientation of the cellulose nanocrystals in the suspensions and films, and the changes in orientation caused by the evaporative process. Mass transfer within the evaporating droplet resulted in the formation of raised rings whose magnitude depended on the degree of pinning of the receding contact line. AFM of dry films at short length scales showed a radial orientation of the CNC at the free surface of the film, along with a radial height variation with a period of approximately P/2, ascribed to the anisotropic shrinkage of the chiral nematic structure.

  20. [Polarized light microscopy for evaluation of oocytes as a prognostic factor in the evolution of a cycle in assisted reproduction].

    Science.gov (United States)

    González-Ortega, C; Cancino-Villarreal, P; Alonzo-Torres, V E; Martínez-Robles, I; Pérez-Peña, E; Gutiérrez-Gutiérrez, A M

    2016-04-01

    Identification of the best embryos to transfer is a key element for success in assisted reproduction. In the last decade, several morphological criteria of oocytes and embryos were evaluated with regard to their potential for predicting embryo viability. The introduction of polarization light microscopy systems has allowed the visualization of the meiotic spindle and the different layers of the zona pellucida in human oocytes on the basis of birefringence in a non-destructive way. Conflicting results have been reported regarding the predictive value in ICSI cycles. To assess the predictive ability of meiotic spindle and zona pellucida of human oocytes to implant by polarized microscopy in ICSI cycles. Prospective and observational clinical study. 903 oocytes from 94 ICSI cycles were analyzed with polarized microscopy. Meiotic spindle visualization and zona pellucida birefringence values by polarized microscopy were correlated with ICSI cycles results. Meiotic spindle visualization and birefringence values of zona pellucida decreased in a direct basis with increasing age. In patients aged over the 35 years, the percentage of a visible spindle and mean zona pellucida birefringence was lower than in younger patients. Fertilization rate were higher in oocytes with visible meiotic spindle (81.3% vs. 64%; p < 0.0001), as well as embryo quality (47.4% vs. 39%; p=0.01). Fertilization rate was higher in oocytes with positive values of birefringence (77.5 % vs. 68.5% p=0.005) with similar embryo quality. Conception cycles showed oocytes with higher mean value of zona birefringence and visible spindle vs. no-conception cycles (p<0.05). Polarized light microscopy improves oocyte selection, which significantly impacts in the development of embryos with greater implantation potential. The use of polarized light microscopy with sperm selection methods, blastocyst culture and deferred embryo transfers will contribute to transfer fewer embryos without diminishing rates of live

  1. Powder agglomeration study in RF silane plasmas by in situ polarization-sensitive laser light scattering and TEM measurements

    International Nuclear Information System (INIS)

    Courteille, C.; Hollenstein, C.; Dorier, J.L.; Gay, P.; Schwarzenbach, W.; Howling, A.A.; Bertran, E.; Viera, G.; Martins, R.; Macarico, A.

    1966-03-01

    To determine self-consistently the time evolution of particle size and their number density in situ multi-angle polarization laser light scattering was used. Cross-polarization intensities (incident and scattered light intensities with opposite polarization) measured at 135 o and ex-situ TEM analysis demonstrate the existence of non-spherical agglomerates during the early phase of agglomeration. Later in the particle time development both techniques reveal spherical particles again. The presence of strong cross-polarization intensities is accompanied by low frequency instabilities detected on the scattered light intensities and plasma emission. It is found that the particle radius and particle number density during the agglomeration phase can be well described by the Brownian Free Molecule Coagulation model. Application of this neutral particle coagulation model is justified by calculation of the particle charge whereby it is shown that particles of a few tens of nanometer can be considered as neutral under our experimental conditions. The measured particle dispersion can be well described by a Brownian Free Molecule Coagulation model including a log-normal particle size distribution. (author) 11 figs., 48 refs

  2. Light-microscopic and electron-microscopic evaluation of short-term nerve regeneration using a biodegradable poly(DL-lactide-epsilon-caprolacton) nerve guide

    NARCIS (Netherlands)

    denDunnen, WFA; Stokroos, [No Value; Blaauw, EH; Holwerda, A; Pennings, AJ; Robinson, PH; Schakenraad, JM

    The aim of this study was to evaluate short-term peripheral nerve regeneration across a IO-mm gap, using a biodegradable poly(DL-lactide-epsilon-caprolacton) nerve guide, with an internal diameter of 1.5 mm and a wall thickness of 0.30 mm. To do so, we evaluated regenerating nerves using light

  3. Analysis of signal processing in vestibular circuits with a novel light-emitting diodes-based fluorescence microscope.

    Science.gov (United States)

    Direnberger, Stephan; Banchi, Roberto; Brosel, Sonja; Seebacher, Christian; Laimgruber, Stefan; Uhl, Rainer; Felmy, Felix; Straka, Hans; Kunz, Lars

    2015-05-01

    Optical visualization of neural network activity is limited by imaging system-dependent technical tradeoffs. To overcome these constraints, we have developed a powerful low-cost and flexible imaging system with high spectral variability and unique spatio-temporal precision for simultaneous optical recording and manipulation of neural activity of large cell groups. The system comprises eight high-power light-emitting diodes, a camera with a large metal-oxide-semiconductor sensor and a high numerical aperture water-dipping objective. It allows fast and precise control of excitation and simultaneous low noise imaging at high resolution. Adjustable apertures generated two independent areas of variable size and position for simultaneous optical activation and image capture. The experimental applicability of this system was explored in semi-isolated preparations of larval axolotl (Ambystoma mexicanum) with intact inner ear organs and central nervous circuits. Cyclic galvanic stimulation of semicircular canals together with glutamate- and γ-aminobutyric acid (GABA)-uncaging caused a corresponding modulation of Ca(2+) transients in central vestibular neurons. These experiments revealed specific cellular properties as well as synaptic interactions between excitatory and inhibitory inputs, responsible for spatio-temporal-specific sensory signal processing. Location-specific GABA-uncaging revealed a potent inhibitory shunt of vestibular nerve afferent input in the predominating population of tonic vestibular neurons, indicating a considerable impact of local and commissural inhibitory circuits on the processing of head/body motion-related signals. The discovery of these previously unknown properties of vestibular computations demonstrates the merits of our novel microscope system for experimental applications in the field of neurobiology. © 2015 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

  4. Assessment of laser photobiomodulation and polarized light on the healing of cutaneous wounds on euthyroid and hypothyroid induced rats

    Science.gov (United States)

    Ramalho, Luciana Maria Pedreira; Weyll, Barbara Mayoral Pedroso; da Costa Lino, Maíra Dória M.; Ramalho, Maria Jose Pedreira; Barbosa Pinheiro, Antonio Luis

    2010-02-01

    The aim of this study was to assess the influence of low-level laser therapy (LLLT) or polarized light (PL) in cutaneous wound healing of hypothyroid rats at dosages of 20 or 40J/cm2. Bioestimulatory effects of Laser radiation and Polarized light are recognized alternative therapies to improve healing on systemic disease patients, but their usefulness in the improvement of hypothyroidism healing impairment is uncertain till date. Forty Wistar rats were used in this study. Hypothyroidism was propylthiouracil- induced. Standard excisional cutaneous wounds were created without suturing and LLLT (λ660nm, 30mW, φ 3mm) or PL (λ 400-2000nm, 40mW, φ 10mm) was applied every 48 hours up to seven days on experimental groups. The rats were killed on the eighth day when wound contraction was assessed. The healing features were evaluated by light microscopy (H/E and Sirius Red). The cutaneous wounds of hypothyroid rats showed delayed healing process characterized by reduced thickness of epithelial layers, incipient formation of disorganized collagen fibers and wound contraction to a lesser extent (FISHER, p=0.0276), when compared to the euthyroid group. The use of both the Laser and Polarized Light on hypothyroid rats increased the amount of fibroblasts and the thickness of collagen fibers, especially on the L 20J/cm2 group. Euthyroid rats have still demonstrated more regular collagen fibers pattern than hypothyroid rats. It was therefore concluded that hypothyroidism delays wound healing and both Laser photobiomodulation and Polarized Light at 20j/cm2 dosages had improved the healing process in hypothyroid rats.

  5. Comparison of effects of Cyriax physiotherapy, a supervised exercise programme and polarized polychromatic non-coherent light (Bioptron light) for the treatment of lateral epicondylitis.

    Science.gov (United States)

    Stasinopoulos, Dimitrios; Stasinopoulos, Ioannis

    2006-01-01

    To compare the effectiveness of Cyriax physiotherapy, a supervised exercise programme, and polarized polychromatic non-coherent light (Bioptron light) in the treatment of lateral epicondylitis. Controlled clinical trial. Rheumatology and rehabilitation centre. This study was carried out with 75 patients who had lateral epicondylitis. They were allocated to three groups by sequential allocation. Group A (n = 25) was treated with Cyriax physiotherapy. A supervised exercise programme was given to group B (n = 25). Group C (n = 25) received polarized polychromatic non-coherent light (Bioptron light). All patients received three treatments per week for four weeks. Pain was evaluated using a visual analogue scale and function using a visual analogue scale and pain-free grip strength at the end of the four-week course of treatment (week 4), one month (week 8), three months (week 16) and six months (week 28) after the end of treatment. The supervised exercise programme produced the largest effect in the reduction of pain and in the improvement of function at the end of the treatment (PBioptron light) may be suitable.

  6. The impact of bright artificial white and 'blue-enriched' light on sleep and circadian phase during the polar winter.

    Science.gov (United States)

    Mottram, Victoria; Middleton, Benita; Williams, Peter; Arendt, Josephine

    2011-03-01

    Delayed sleep phase (and sometimes free-run) is common in the Antarctic winter (no natural sunlight) and optimizing the artificial light conditions is desirable. This project evaluated sleep when using 17,000 K blue-enriched lamps compared with standard white lamps (5000 K) for personal and communal illumination. Base personnel, 10 males, five females, 32.5±8 years took part in the study. From 24 March to 21 September 2006 light exposure alternated between 4-5-week periods of standard white (5000 K) and blue-enriched lamps (17,000 K), with a 3-week control before and after extra light. Sleep and light exposure were assessed by actigraphy and sleep diaries. General health (RAND 36-item questionnaire) and circadian phase (urinary 6-sulphatoxymelatonin rhythm) were evaluated at the end of each light condition. Direct comparison (rmanova) of blue-enriched light with white light showed that sleep onset was earlier by 19 min (P=0.022), and sleep latency tended to be shorter by 4 min (P=0.065) with blue-enriched light. Analysing all light conditions, control, blue and white, again provided evidence for greater efficiency of blue-enriched light compared with white (Plight conditions. Circadian phase was earlier on average in midwinter blue compared with midwinter white light by 45 min (PLight condition had no influence on general health. We conclude that the use of blue-enriched light had some beneficial effects, notably earlier sleep, compared with standard white light during the polar winter. © 2010 European Sleep Research Society.

  7. A light microscopic study of the course of cellular division of Giardia intestinalis trophozoites grown in vitro.

    Science.gov (United States)

    Cerva, L; Nohýnková, E

    1992-01-01

    The cellular division of trophozoites of Giardia intestinalis group was followed microscopically in stained preparations from axenic cultures. Eleven successive stages were described, documented by photomicrographs and their survival times calculated.

  8. Erosion Potential of Tooth Whitening Regimens as Evaluated with Polarized Light Microscopy.

    Science.gov (United States)

    Brambert, Patrick; Qian, Fang; Kwon, So Ran

    2015-11-01

    Tooth whitening is a widely utilized esthetic treatment in dentistry. With increased access to over-the-counter (OTC) systems concerns have been raised as to potential adverse effects associated with overuse of whitening materials. Therefore, this study aimed to evaluate enamel erosion due to different whitening regimens when used in excess of recommended guidelines. Extracted human teeth (n = 66) were randomly divided into 11 groups (n = 6/group). Specimens were exposed to OTC products: Crest Whitestrips and 5-minute natural white and a do-it-yourself (DIY) strawberry whitening recipe. Within each regimen, groups were further divided per exposure time: specimens receiving the recommended product dosage; 5 times the recommended dosage; and 10 times the recommended dosage. Negative and positive controls were treated with grade 3 water and 1.0% citric acid, respectively. Specimens were nail-varnished to limit application to a 1 × 4 mm window. Following treatment, specimens were sectioned and erosion (drop in μm) measured using polarized light microscopy. Two-sample t-test was used to detect difference in amount of enamel erosion between negative and positive groups, while one-way analysis of variance (ANOVA), followed by post hoc Dunnett's test was used to detect difference between set of treatment groups and negative control groups or among all experimental groups. There was significant difference in mean amount of enamel erosion (p erosion for positive control group was significantly greater than that for negative control group (23.50 vs 2.65 μm). There was significant effect for type of treatments on enamel erosion [F(9,50) = 25.19; p 0.05 for all instances), except for Natural White_10 times treatment group (p erosion. Enamel erosion due to the overuse of whitening products varies for different modalities and products. Therefore, caution is advised when using certain over-the-counter products beyond recommended guidelines, as there is potential for enamel

  9. Linearly polarized light emission from InGaN/GaN quantum well structure with high indium composition.

    Science.gov (United States)

    Song, Hooyoung; Kim, Eun Kyu; Han, Il Ki; Lee, Sung-Ho; Hwang, Sung-Min

    2011-10-01

    We fabricated yellow (575 nm) emitting a-plane InGaN/GaN light emitting diode (LED). Microstructure and stress relaxation of the InGaN well layer were observed from the images of dark field transmission electron microscopy. The LED chip was operated at 3.7 V, 20 mA, and the polarization-free characteristic in nonpolar InGaN layer was confirmed from a small blue-shift of approximaely 1.7 nm with increase of current density. The high photoluminescence (PL) efficiency of 30.4% showed that this non-polar InGaN layer has a potential of application to green-red long wavelength light emitters. The PL polarization ratio at 290 K was 0.25 and the energy difference between two subbands was estimated to be 40.2 meV. The low values of polarization and energy difference were due to the stress relaxation of InGaN well layer.

  10. Evaluation of Malaria Diagnoses Using a Handheld Light Microscope in a Community-Based Setting in Rural Côte d'Ivoire.

    Science.gov (United States)

    Coulibaly, Jean T; Ouattara, Mamadou; Keiser, Jennifer; Bonfoh, Bassirou; N'Goran, Eliézer K; Andrews, Jason R; Bogoch, Isaac I

    2016-10-05

    Portable microscopy may facilitate quality diagnostic care in resource-constrained settings. We compared a handheld light microscope (Newton Nm1) with a mobile phone attachment to conventional light microscopy for the detection of Plasmodium falciparum in a cross-sectional study in rural Côte d'Ivoire. Single Giemsa-stained thick blood film from 223 individuals were prepared and read by local laboratory technicians on both microscopes under 1,000× magnification with oil. Of the 223 samples, 162 (72.6%) were P. falciparum positive, and the overall mean parasite count was 1,392/μL of blood. Sensitivity and specificity of the handheld microscope was 80.2% (95% confidence interval [CI]: 73.1-85.9%) and 100.0% (95% CI: 92.6-100.0%), respectively, with a positive and negative predictive value of 100.0% (95% CI: 96.4-100.0%) and 65.6% (95% CI: 54.9-74.9%), respectively. If sensitivity can be improved, handheld light microscopy may become a valuable public health tool for P. falciparum diagnosis. © The American Society of Tropical Medicine and Hygiene.

  11. Polarized scattered light from self-luminous exoplanets : Three-dimensional scattering radiative transfer with ARTES

    NARCIS (Netherlands)

    Stolker, T.; Min, M.; Stam, D.M.; Mollière, P.; Dominik, C.; Waters, L. B.F.M.

    2017-01-01

    Context. Direct imaging has paved the way for atmospheric characterization of young and self-luminous gas giants. Scattering in a horizontally-inhomogeneous atmosphere causes the disk-integrated polarization of the thermal radiation to be linearly polarized, possibly detectable with the newest

  12. Impact of light polarization on photoluminescence intensity and quantum efficiency in AlGaN and AlInGaN layers

    Science.gov (United States)

    Netzel, C.; Knauer, A.; Weyers, M.

    2012-12-01

    We analyzed emission intensity, quantum efficiency, and emitted light polarization of c-plane AlGaN and AlInGaN layers (λ = 320-350 nm) by temperature dependent photoluminescence. Low indium content in AlInGaN structures causes a significant intensity increase by change of the polarization of the emitted light. Polarization changes from E ⊥ c to E ‖ c with increasing aluminum content. It switches back to E ⊥ c with the incorporation of indium. The polarization degree decreases with temperature. This temperature dependence can corrupt internal quantum efficiency determination by temperature dependent photoluminescence.

  13. Photo double ionization of helium 100 eV and 450 eV above threshold: II. Circularly polarized light

    International Nuclear Information System (INIS)

    Knapp, A; Kheifets, A; Bray, I; Weber, Th; Landers, A L; Schoessler, S; Jahnke, T; Nickles, J; Kammer, S; Jagutzki, O; Schmidt, L Ph H; Schoeffler, M; Osipov, T; Prior, M H; Schmidt-Boecking, H; Cocke, C L; Doerner, R

    2005-01-01

    We present a joint experimental and theoretical study of the fully differential cross section of the photo double ionization of helium with left and right circularly polarized light at E exc = 100 eV and 450 eV above the threshold. We analyse angular distributions for the slow electron and the normalized circular dichroism for various energy sharings of the excess energy between the two electrons. The experimental results are well reproduced by convergent close coupling calculations

  14. Nonlinear unitary transformations of space-variant polarized light fields from self-induced geometric-phase optical elements

    Science.gov (United States)

    Kravets, Nina; Brasselet, Etienne

    2018-01-01

    We propose to couple the optical orientational nonlinearities of liquid crystals with their ability to self-organize to tailor them to control space-variant-polarized optical fields in a nonlinear manner. Experimental demonstration is made using a liquid crystal light valve that behaves like a light-driven geometric phase optical element. We also unveil two original nonlinear optical processes, namely self-induced separability and nonseparability. These results contribute to the advancement of nonlinear singular optics that is still in its infancy despite 25 years of effort, which may foster the development of nonlinear protocols to manipulate high-dimensional optical information both in the classical and quantum regimes.

  15. Polarization Switching and Light-Enhanced Piezoelectricity in Lead Halide Perovskites.

    Science.gov (United States)

    Coll, Mariona; Gomez, Andrés; Mas-Marza, Elena; Almora, Osbel; Garcia-Belmonte, Germà; Campoy-Quiles, Mariano; Bisquert, Juan

    2015-04-16

    We investigate the ferroelectric properties of photovoltaic methylammonium lead halide CH3NH3PbI3 perovskite using piezoelectric force microscopy (PFM) and macroscopic polarization methods. The electric polarization is clearly observed by amplitude and phase hysteresis loops. However, the polarization loop decreases as the frequency is lowered, persisting for a short time only, in the one second regime, indicating that CH3NH3PbI3 does not exhibit permanent polarization at room temperature. This result is confirmed by macroscopic polarization measurement based on a standard capacitive method. We have observed a strong increase of piezoelectric response under illumination, consistent with the previously reported giant photoinduced dielectric constant at low frequencies. We speculate that an intrinsic charge transfer photoinduced dipole in the perovskite cage may lie at the origin of this effect.

  16. Chirality Emergence in Thin Solid Films of Amino Acids by Polarized Light from Synchrotron Radiation and Free Electron Laser

    Directory of Open Access Journals (Sweden)

    Mashahiro Adachi

    2009-07-01

    Full Text Available One of the most attractive hypothesis for the origin of homochirality in terrestrial bioorganic compounds is that a kind of “chiral impulse” as an asymmetric excitation source induced asymmetric reactions on the surfaces of such materials such as meteorites or interstellar dusts prior to the existence of terrestrial life (Cosmic Scenario. To experimentally introduce chiral structure into racemic films of amino acids (alanine, phenylalanine, isovaline, etc., we irradiated them with linearly polarized light (LPL from synchrotron radiation and circularly polarized light (CPL from a free electron laser. After the irradiation, we evaluated optical anisotropy by measuring the circular dichroism (CD spectra and verified that new Cotton peaks appeared at almost the same peak position as those of the corresponding non-racemic amino acid films. With LPL irradiation, two-dimensional anisotropic structure expressed as linear dichroism and/or linear birefringence was introduced into the racemic films. With CPL irradiation, the signs of the Cotton peaks exhibit symmetrical structure corresponding to the direction of CPL rotation. This indicates that some kinds of chiral structure were introduced into the racemic film. The CD spectra after CPL irradiation suggest the chiral structure should be derived from not only preferential photolysis but also from photolysis-induced molecular structural change. These results suggest that circularly polarized light sources in space could be associated with the origin of terrestrial homochirality; that is, they would be effective asymmetric exciting sources introducing chiral structures into bio-organic molecules or complex organic compounds.

  17. Phototaxis and polarotaxis hand in hand: night dispersal flight of aquatic insects distracted synergistically by light intensity and reflection polarization.

    Science.gov (United States)

    Boda, Pál; Horváth, Gábor; Kriska, György; Blahó, Miklós; Csabai, Zoltán

    2014-05-01

    Based on an earlier observation in the field, we hypothesized that light intensity and horizontally polarized reflected light may strongly influence the flight behaviour of night-active aquatic insects. We assumed that phototaxis and polarotaxis together have a more harmful effect on the dispersal flight of these insects than they would have separately. We tested this hypothesis in a multiple-choice field experiment using horizontal test surfaces laid on the ground. We offered simultaneously the following visual stimuli for aerial aquatic insects: (1) lamplit matte black canvas inducing phototaxis alone, (2) unlit shiny black plastic sheet eliciting polarotaxis alone, (3) lamplit shiny black plastic sheet inducing simultaneously phototaxis and polarotaxis, and (4) unlit matte black canvas as a visually unattractive control. The unlit matte black canvas trapped only a negligible number (13) of water insects. The sum (16,432) of the total numbers of water beetles and bugs captured on the lamplit matte black canvas (7,922) and the unlit shiny black plastic sheet (8,510) was much smaller than the total catch (29,682) caught on the lamplit shiny black plastic sheet. This provides experimental evidence for the synergistic interaction of phototaxis (elicited by the unpolarized direct lamplight) and polarotaxis (induced by the strongly and horizontally polarized plastic-reflected light) in the investigated aquatic insects. Thus, horizontally polarizing artificial lamplit surfaces can function as an effective ecological trap due to this synergism of optical cues, especially in the urban environment.

  18. Solving structure in the CP29 light harvesting complex with polarization-phased 2D electronic spectroscopy

    Science.gov (United States)

    Ginsberg, Naomi S.; Davis, Jeffrey A.; Ballottari, Matteo; Cheng, Yuan-Chung; Bassi, Roberto; Fleming, Graham R.

    2011-01-01

    The CP29 light harvesting complex from green plants is a pigment-protein complex believed to collect, conduct, and quench electronic excitation energy in photosynthesis. We have spectroscopically determined the relative angle between electronic transition dipole moments of its chlorophyll excitation energy transfer pairs in their local protein environments without relying on simulations or an X-ray crystal structure. To do so, we measure a basis set of polarized 2D electronic spectra and isolate their absorptive components on account of the tensor relation between the light polarization sequences used to obtain them. This broadly applicable advance further enhances the acuity of polarized 2D electronic spectroscopy and provides a general means to initiate or feed back on the structural modeling of electronically-coupled chromophores in condensed phase systems, tightening the inferred relations between the spatial and electronic landscapes of ultrafast energy flow. We also discuss the pigment composition of CP29 in the context of light harvesting, energy channeling, and photoprotection within photosystem II. PMID:21321222

  19. Chirality Emergence in Thin Solid Films of Amino Acids by Polarized Light from Synchrotron Radiation and Free Electron Laser

    Science.gov (United States)

    Takahashi, Jun-ichi; Shinojima, Hiroyuki; Seyama, Michiko; Ueno, Yuko; Kaneko, Takeo; Kobayashi, Kensei; Mita, Hajime; Adachi, Mashahiro; Hosaka, Masahito; Katoh, Masahiro

    2009-01-01

    One of the most attractive hypothesis for the origin of homochirality in terrestrial bioorganic compounds is that a kind of “chiral impulse” as an asymmetric excitation source induced asymmetric reactions on the surfaces of such materials such as meteorites or interstellar dusts prior to the existence of terrestrial life (Cosmic Scenario). To experimentally introduce chiral structure into racemic films of amino acids (alanine, phenylalanine, isovaline, etc.), we irradiated them with linearly polarized light (LPL) from synchrotron radiation and circularly polarized light (CPL) from a free electron laser. After the irradiation, we evaluated optical anisotropy by measuring the circular dichroism (CD) spectra and verified that new Cotton peaks appeared at almost the same peak position as those of the corresponding non-racemic amino acid films. With LPL irradiation, two-dimensional anisotropic structure expressed as linear dichroism and/or linear birefringence was introduced into the racemic films. With CPL irradiation, the signs of the Cotton peaks exhibit symmetrical structure corresponding to the direction of CPL rotation. This indicates that some kinds of chiral structure were introduced into the racemic film. The CD spectra after CPL irradiation suggest the chiral structure should be derived from not only preferential photolysis but also from photolysis-induced molecular structural change. These results suggest that circularly polarized light sources in space could be associated with the origin of terrestrial homochirality; that is, they would be effective asymmetric exciting sources introducing chiral structures into bio-organic molecules or complex organic compounds. PMID:19742124

  20. Treatment of Carpal Tunnel Syndrome in pregnancy with Polarized Polychromatic Non-coherent Light (Bioptron Light): A Preliminary, Prospective, Open Clinical Trial.

    Science.gov (United States)

    Dimitrios, Stasinopoulos; Stasinopoulos, Loannis

    2017-12-31

    The aim of this trial was to assess the efficacy of polarized polychromatic noncoherent light (Bioptron light) in the treatment of Carpal Tunnel Syndrome (CTS) in pregnancy. An uncontrolled experimental study was conducted in pregnant patients with CTS who visited our clinic from January 2006 to January 2010. Bioptron light (480-3400 nm; 95% polarization; 40 mW/cm 2 ; and 2.4 J/cm 2 ) was administered perpendicular to the carpal tunnel area. The irradiation time for each session was 6 min at an operating distance of 5-10 cm from the carpal tunnel area, twice each day, five days per week for 2 weeks. Pain and paraesthesia using a visual analogue scale (VAS) and finger pinch strength were evaluated at the end of treatment (week 2) and 1-month (week 6) after the end of treatment. The Student'sttest was used and p values Bioptron light is a reliable, safe, and effective treatment option in pregnant patients with CTS. Controlled clinical trials are needed to establish the absolute and relative effectiveness of this intervention.

  1. Polarized light (λ400-2000 nm) on third-degree burns in diabetic rats: immunohistochemical study.

    Science.gov (United States)

    Oliveira, Priscila Chagas; Pinheiro, Antônio Luiz Barbosa; Reis Junior, João Alves; de Castro, Isabelle C V; Gurgel, Clarissa; Noia, Manuela Pimentel; Meireles, Gyselle C S; Cangussu, Maria Cristina; Ramalho, Luciana Maria Pedreira

    2010-10-01

    The aim of this study was to evaluate with light microscopy the healing process of third-degree burns on diabetic rats treated with polarized light (λ400-2000 nm, 20 or 40 J/cm(2)/session, 40 mW/cm(2), 2.4 J/cm(2)/min, 5.5-cm beam diameter). Uncontrolled diabetes mellitus causes severe disruption of the body's metabolism, including healing. Polarized light sources have been shown to be effective in improving healing in many situations. Diabetes mellitus was induced with streptozotocin (60 mg/kg) in 45 male Wistar albino rats, and a third-degree burn (1.5 by 1.5 cm) was created on the dorsum of each animal under general anesthesia. The animals were randomly distributed into three groups: control, 20 J/cm(2), and 40 J/cm(2). Each group was then divided into three subgroups based on time of death (7, 14, 21 d). Phototherapy (20 or 40 J/cm(2) per session) was carried out immediately after the burning and repeated daily until the day before death. Following animal death, specimens were removed, embedded in paraffin, sectioned, and stained with hematoxylin and eosin (HE) or Sirius Red or immunomarked with CK AE1/AE3 antibody. Qualitative and semiquantitative analyses were performed under light microscopy. The results were statistically analyzed. The animals treated with 20 J/cm(2) showed significant differences with regard to revascularization and re-epithelialization. Although the 40 J/cm(2) group showed stimulation of fibroblastic proliferation as an isolated feature, no other difference from the control was observed. Our results suggest that the use of polarized light at 20 J/cm(2) effectively improves the healing of third-degree burns on diabetic animals at both early and late stages of repair.

  2. Mutual conversion and asymmetric transmission of linearly polarized light in bilayered chiral metamaterial.

    Science.gov (United States)

    Xu, Yiqun; Shi, Quanchao; Zhu, Zheng; Shi, Jinhui

    2014-10-20

    We propose a kind of planar chiral optical metamaterial consisting of two layers of connected I-shape resonators arranged by a twist angle of 90°. Numerical simulation results demonstrate that our scheme can realize a mutual polarization conversion and dual-band asymmetric transmission for linearly polarized waves in the optical regime. For the forward propagation, the x-to-y and y-to-x polarization conversions in the proposed bilayered metamaterial result from the concentric and eccentric C-shaped dimers, respectively. The current distributions of bilayered metamaterials at the resonant frequencies are presented to interpret the dual-band asymmetric transmission. The polarization conversion efficiency and resonant frequencies can be modified via parametric study.

  3. Time-resolved ultraviolet near-field scanning optical microscope for characterizing photoluminescence lifetime of light-emitting devices.

    Science.gov (United States)

    Park, Kyoung-Duck; Jeong, Hyun; Kim, Yong Hwan; Yim, Sang-Youp; Lee, Hong Seok; Suh, Eun-Kyung; Jeong, Mun Seok

    2013-03-01

    We developed a instrument consisting of an ultraviolet (UV) near-field scanning optical microscope (NSOM) combined with time-correlated single photon counting, which allows efficient observation of temporal dynamics of near-field photoluminescence (PL) down to the sub-wavelength scale. The developed time-resolved UV NSOM system showed a spatial resolution of 110 nm and a temporal resolution of 130 ps in the optical signal. The proposed microscope system was successfully demonstrated by characterizing the near-field PL lifetime of InGaN/GaN multiple quantum wells.

  4. Influence of light polarization on the dynamics of optically pumped lasers

    Energy Technology Data Exchange (ETDEWEB)

    Arjona, M.; Corbalan, R. (Departament de Fisica, Universitat Autonoma de Barcelona, 08193 Bellaterra (Spain)); Laguarta, F.; Pujol, J. (Departament d' Optica i Optometria, Universitat Politecnica de Catalunya, 08222 Terrassa (Spain)); Vilaseca, R. (Departament I. D' Optica, Universitat de Valencia, 46100 Burjassot (Spain))

    1990-06-01

    The dynamic behavior of a coherently pumped ring laser with a homogeneously broadened four-level medium is analyzed theoretically, considering linearly polarized pump and generated laser beams. The laser is shown to be much more stable when these polarizations are parallel than when they are orthogonal. In the latter case the instability pump threshold can be as low as four times the first laser threshold, and the laser dynamics shows Lorenz-type features.

  5. A note about retinal structure and visual acuity. A light microscopic study of the cones in fovea centralis

    DEFF Research Database (Denmark)

    Rostgaard, Jørgen; Qvortrup, Klaus

    1999-01-01

    Primate eye, retina, fovea centralis, cone cells, non-shrinkage methods, light microscopy, resolution......Primate eye, retina, fovea centralis, cone cells, non-shrinkage methods, light microscopy, resolution...

  6. Light

    CERN Document Server

    Robertson, William C

    2003-01-01

    Why is left right and right left in the mirror? Baffled by the basics of reflection and refraction? Wondering just how the eye works? If you have trouble teaching concepts about light that you don t fully grasp yourself, get help from a book that s both scientifically accurate and entertaining with Light. By combining clear explanations, clever drawings, and activities that use easy-to-find materials, this book covers what science teachers and parents need to know to teach about light with confidence. It uses ray, wave, and particle models of light to explain the basics of reflection and refraction, optical instruments, polarization of light, and interference and diffraction. There s also an entire chapter on how the eye works. Each chapter ends with a Summary and Applications section that reinforces concepts with everyday examples. Whether you need a deeper understanding of how light bends or a good explanation of why the sky is blue, you ll find Light more illuminating and accessible than a college textbook...

  7. Simultaneous in situ measurements of properties of particulates in rf silane plasmas using a polarization-sensitive laser-light-scattering method

    Science.gov (United States)

    Shiratani, Masaharu; Kawasaki, Hiroharu; Fukuzawa, Tsuyoshi; Yoshioka, Takashi; Ueda, Yoshio; Singh, Sanjay; Watanabe, Yukio

    1996-01-01

    A polarization-sensitive laser-light-scattering method is developed for simultaneous in situ measurements of properties (size, size dispersion, density, and refractive index) of particulates formed in processing plasmas. The developed system is applied to observe the growth processes of particulates in a range of their size larger than about 10 nm in rf silane plasmas. A size, a size dispersion (logarithm of a standard deviation of size), a density, and a refractive index of particulates in the plasmas are found to be 10-200 nm, about 0.1, 107-109 cm-3 and about 3-5i, respectively. The former three of such values agree fairly well with ones deduced from scanning electron microscopic (SEM) observation. These particulates grow through three phases of nucleation and initial growth, rapid growth, and growth saturation. Coexistence of two size groups of particulates with narrow size dispersions during and after the rapid growth phase verified by the SEM observation may be explained by a model taking into account coagulation between oppositely charged particulates.

  8. Tailoring of polarization in electron blocking layer for electron confinement and hole injection in ultraviolet light-emitting diodes

    International Nuclear Information System (INIS)

    Lu, Yu-Hsuan; Pilkuhn, Manfred H.; Fu, Yi-Keng; Chu, Mu-Tao; Huang, Shyh-Jer; Su, Yan-Kuin; Wang, Kang L.

    2014-01-01

    The influence of the AlGaN electron blocking layer (EBL) with graded aluminum composition on electron confinement and hole injection in AlGaN-based ultraviolet light-emitting diodes (LEDs) are investigated. The light output power of LED with graded AlGaN EBL was markedly improved, comparing to LED with conventional EBL. In experimental results, a high increment of 86.7% can be obtained in light output power. Simulation analysis shows that via proper modification of the barrier profile from the last barrier of the active region to EBL, not only the elimination of electron overflow to p-type layer can be achieved but also the hole injection into the active region can be enhanced, compared to a conventional LED structure. The dominant factor to the performance improvement is shown to be the modulation of polarization field by the graded Al composition in EBL

  9. Tailoring of polarization in electron blocking layer for electron confinement and hole injection in ultraviolet light-emitting diodes

    Energy Technology Data Exchange (ETDEWEB)

    Lu, Yu-Hsuan; Pilkuhn, Manfred H. [Department of Electrical Engineering, Institute of Microelectronics and Advanced Optoelectronic Technology Center, National Cheng Kung University, Tainan 70101, Taiwan (China); Fu, Yi-Keng; Chu, Mu-Tao [Electronics and Optoelectronics Research Laboratories, Industrial Technology Research Institute, Hsinchu 31040, Taiwan (China); Huang, Shyh-Jer, E-mail: yksu@mail.ncku.edu.tw, E-mail: totaljer48@gmail.com [Department of Electrical Engineering, Institute of Microelectronics and Advanced Optoelectronic Technology Center, National Cheng Kung University, Tainan 70101, Taiwan (China); Department of Electrical Engineering, University of California at Los Angeles, Los Angeles, California 90095 (United States); Su, Yan-Kuin, E-mail: yksu@mail.ncku.edu.tw, E-mail: totaljer48@gmail.com [Department of Electrical Engineering, Institute of Microelectronics and Advanced Optoelectronic Technology Center, National Cheng Kung University, Tainan 70101, Taiwan (China); Department of Electronic Engineering, Kun-Shan University, Tainan 71003, Taiwan (China); Wang, Kang L. [Department of Electrical Engineering, University of California at Los Angeles, Los Angeles, California 90095 (United States)

    2014-03-21

    The influence of the AlGaN electron blocking layer (EBL) with graded aluminum composition on electron confinement and hole injection in AlGaN-based ultraviolet light-emitting diodes (LEDs) are investigated. The light output power of LED with graded AlGaN EBL was markedly improved, comparing to LED with conventional EBL. In experimental results, a high increment of 86.7% can be obtained in light output power. Simulation analysis shows that via proper modification of the barrier profile from the last barrier of the active region to EBL, not only the elimination of electron overflow to p-type layer can be achieved but also the hole injection into the active region can be enhanced, compared to a conventional LED structure. The dominant factor to the performance improvement is shown to be the modulation of polarization field by the graded Al composition in EBL.

  10. Light and electron microscopic immunocytochemistry of neurons in the blowfly optic lobe reacting with antisera to RFamide and FMRFamide

    DEFF Research Database (Denmark)

    Nässel, D R; Ohlsson, Lisbeth; Johansson, K U

    1988-01-01

    processes. In the medulla the RF-like immunoreactive processes are arranged in strict layers whereas in the lobula complex the distribution is diffuse. Electron microscopic immunocytochemistry, using both pre-embedding immuno peroxidase-antiperoxidase and post-embedding protein A-gold labeling, was employed...

  11. Differentiating characteristic microstructural features of cancerous tissues using Mueller matrix microscope.

    Science.gov (United States)

    Wang, Ye; He, Honghui; Chang, Jintao; Zeng, Nan; Liu, Shaoxiong; Li, Migao; Ma, Hui

    2015-12-01

    Polarized light imaging can provide rich microstructural information of samples, and has been applied to the detections of various abnormal tissues. In this paper, we report a polarized light microscope based on Mueller matrix imaging by adding the polarization state generator and analyzer (PSG and PSA) to a commercial transmission optical microscope. The maximum errors for the absolute values of Mueller matrix elements are reduced to 0.01 after calibration. This Mueller matrix microscope has been used to examine human cervical and liver cancerous tissues with fibrosis. Images of the transformed Mueller matrix parameters provide quantitative assessment on the characteristic features of the pathological tissues. Contrast mechanism of the experimental results are backed up by Monte Carlo simulations based on the sphere-cylinder birefringence model, which reveal the relationship between the pathological features in the cancerous tissues at the cellular level and the polarization parameters. Both the experimental and simulated data indicate that the microscopic transformed Mueller matrix parameters can distinguish the breaking down of birefringent normal tissues for cervical cancer, or the formation of birefringent surrounding structures accompanying the inflammatory reaction for liver cancer. With its simple structure, fast measurement and high precision, polarized light microscope based on Mueller matrix shows a good diagnosis application prospect. Copyright © 2015 Elsevier Ltd. All rights reserved.

  12. Circular Polarization of Light By Planet Mercury and Enantiomorphism of Its Surface Minerals

    Science.gov (United States)

    Meierhenrich, U. J.; Thiemann, W. H.-P.; Barbier, B.; Brack, A.; Nahon, L.; Alcaraz, C.; Wolstencroft, R.

    Different mechanisms for the generation of circular polarization on the surface of planets and satellites are described. The observed values for Venus, the Moon, Mars, and Jupiter obtained by photo-polarimetric measurements with Earth based telescopes, showed accordance with theory. However, for planet Mercury asymmetric parameters in the circular polarization were measured that do not fit with calculations. For Bepi- Colombo, we propose to investigate this phenomenon using a concept which includes two instruments. The first instrument is a high-resolution optical polarimeter,[1,2] ca- pable to determine and map the circular polarization by remote scanning of Mercury's surface from the Mercury Planetary Orbiter MPO. The second instrument is an in situ sensor for the detection of the enantiomorphism of surface crystals and minerals, proposed to be included in the Mercury Lander MSE. [1] C. Alcaraz, R. Thissen, M. Compin, A. Jolly, M. Drescher, L. Nahon: First po- larization measurements of Ophelie: a versatile polarization VUV undulator at Super- Aco. SPIE 3773 (1999), 250-261. [2] C. Alcaraz, J.L. Marlats, D. Nether, B. Pilette, L. Nahon: A dedicated precise polarimeter for measurement of VUV versatile photon polarizations, Applied Optics, manuscript under preparation.

  13. submitter Phase transition observations and discrimination of small cloud particles by light polarization in expansion chamber experiments

    CERN Document Server

    Nichman, Leonid; Järvinen, Emma; Ignatius, Karoliina; Höppel, Niko Florian; Dias, Antonio; Heinritzi, Martin; Simon, Mario; Tröstl, Jasmin; Wagner, Andrea Christine; Wagner, Robert; Williamson, Christina; Yan, Chao; Connolly, Paul James; Dorsey, James Robert; Duplissy, Jonathan; Ehrhart, Sebastian; Frege, Carla; Gordon, Hamish; Hoyle, Christopher Robert; Kristensen, Thomas Bjerring; Steiner, Gerhard; McPherson Donahue, Neil; Flagan, Richard; Gallagher, Martin William; Kirkby, Jasper; Möhler, Ottmar; Saathoff, Harald; Schnaiter, Martin; Stratmann, Frank; Tomé, António

    2016-01-01

    Cloud microphysical processes involving the ice phase in tropospheric clouds are among the major uncertainties in cloud formation, weather, and general circulation models. The detection of aerosol particles, liquid droplets, and ice crystals, especially in the small cloud particle-size range below 50 μm, remains challenging in mixed phase, often unstable environments. The Cloud Aerosol Spectrometer with Polarization (CASPOL) is an airborne instrument that has the ability to detect such small cloud particles and measure the variability in polarization state of their backscattered light. Here we operate the versatile Cosmics Leaving OUtdoor Droplets (CLOUD) chamber facility at the European Organization for Nuclear Research (CERN) to produce controlled mixed phase and other clouds by adiabatic expansions in an ultraclean environment, and use the CASPOL to discriminate between different aerosols, water, and ice particles. In this paper, optical property measurements of mixed-phase clouds and viscous secondary ...

  14. Analysis of the effect of polarization traps and shallow impurities on the interlevel light absorption of quantum dots

    Directory of Open Access Journals (Sweden)

    V.I. Boichuk

    2017-12-01

    Full Text Available A spherical quantum dot (QD heterosystem CdS/SiO2 has been studied. Each QD has a hydrogen-like impurity in its center. Besides that, it has been accounted that a polarization trap for electron exists at the interfaces due to the difference between the QD and matrix dielectric permittivity. It has been defined that for small QD radii there are surface electron states. For different radii, partial contributions of the surface states into the electron energy caused by the electron-ion and electron-polarization charges interaction have been defined. The linear light absorption coefficient of noninteracting QDs has been calculated taking into account the QD dispersion by the size. It is shown that the surface states can be observed into different ranges of an electromagnetic spectrum.

  15. Localized enhancement of electric field in tip-enhanced Raman spectroscopy using radially and linearly polarized light.

    Science.gov (United States)

    Kazemi-Zanjani, Nastaran; Vedraine, Sylvain; Lagugné-Labarthet, François

    2013-10-21

    Finite-Difference Time-Domain (FDTD) calculations are used to characterize the electric field in the vicinity of a sharp silver or gold cone with an apex diameter of 10 nm. The simulations are utilized to predict the intensity and the distribution of the locally enhanced electric field in tip-enhanced Raman spectroscopy (TERS). A side-by-side comparison of the enhanced electric field induced by a radially and a linearly polarized light in both gap-mode and conventional TERS setup is performed. For this purpose, a radially polarized source is introduced and integrated into the FDTD modeling. Additionally, the optical effect of a thin protective layer of alumina on the enhancement of the electric field is investigated.

  16. Effects of electric field and light polarization on the electromagnetically induced transparency in an impurity doped quantum ring

    Science.gov (United States)

    Bejan, D.; Stan, C.; Niculescu, E. C.

    2018-01-01

    We theoretically investigated the effects of the impurity position, in-plane electric field, intensity and polarization of the probe and control lasers on the electromagnetically induced transparency (EIT) in GaAs/GaAlAs disc shaped quantum ring. Our study reveals that, depending on the impurity position, the quantum system presents two specific configurations for the EIT occurrence even in the absence of the external electric field, i.e. ladder-configuration or V-configuration, and changes the configuration from ladder to V for specific electric field values. The polarization of the probe and control lasers plays a crucial role in obtaining a good transparency. The electric field controls the red-shift (blue-shift) of the transparency window and modifies its width. The system exhibits birefringence for the probe light in a limited interval of electric field values.

  17. Circular polarization of light by planet Mercury and enantiomorphism of its surface minerals.

    Science.gov (United States)

    Meierhenrich, Uwe J; Thiemann, Wolfram H P; Barbier, Bernard; Brack, André; Alcaraz, Christian; Nahon, Laurent; Wolstencroft, Ray

    2002-04-01

    Different mechanisms for the generation of circular polarization by the surface of planets and satellites are described. The observed values for Venus, the Moon, Mars, and Jupiter obtained by photo-polarimetric measurements with Earth based telescopes, showed accordance with theory. However, for planet Mercury asymmetric parameters in the circular polarization were measured that do not fit with calculations. For BepiColombo, the ESA cornerstone mission 5 to Mercury, we propose to investigate this phenomenon using a concept which includes two instruments. The first instrument is a high-resolution optical polarimeter, capable to determine and map the circular polarization by remote scanning of Mercury's surface from the Mercury Planetary Orbiter MPO. The second instrument is an in situ sensor for the detection of the enantiomorphism of surface crystals and minerals, proposed to be included in the Mercury Lander MSE.

  18. Polarized light microscopy-detectable structures of human oocytes and embryos are related to the likelihood of conception in IVF.

    Science.gov (United States)

    Molinari, Emanuela; Evangelista, Francesca; Racca, Cinzia; Cagnazzo, Celeste; Revelli, Alberto

    2012-10-01

    To clarify if birefringent structures of human oocytes and embryos, measurable by polarized light microscopy, have any value in predicting the chance of pregnancy in human in vitro fertilization and may halp to identify the most competent oocytes and embryos. The inner layer of the zona pellucida (IL-ZP) and the meiotic spindle (MS) were analyzed by polarized light microscopy in 258 oocytes and in the 209 embryos deriving from them. Data obtained from 102 ICSI cycles with conception were compared with those obtained in 156 cycles without conception. The retardance and area of the IL-ZP, as well as the retardance, length of the major axis, and area of the MS were measured. Furthermore, polarized light microscopy parameters were related to the embryo morphological score by multiple regression analysis. The mean area of the IL-ZP of both oocytes and embryos was significantly lower in conception than in non-conception cycles (p = 0.0001 for oocytes and p = 0.002 for embryos). The area of the IL-ZP in embryos was significantly, inversely related to the embryo morphological score (p = 0.011). The area, the major axis length and the retarcance of the MS, as well as the retardance of the IL-ZP in oocytes and embryos were comparable in conception and non-conception cycles. The area of the IL-ZP of the human oocytes may represent a marker of oocyte competence, as oocytes with a low IL-ZP area are more frequently obtained in conception cycles. When measured in embryos, a low IL-ZP area identifies embryos with a high chance of implantation.

  19. Influence of polar solvents on the enhancement of light-ends in ...

    African Journals Online (AJOL)

    Crude oil 'micelle' can be dispersed into fuels, oil and resin/asphalthene components using some hydrocarbon solvents. This can be adapted towards influencing/enhancing its product slates during the processing of crude oils. This research was carried out to investigate the effect of polar solvents (ethanol and acetone) in ...

  20. Moving systems of polar dimeric capsules out of thermal equilibrium by light irradiation.

    Science.gov (United States)

    Díaz-Moscoso, Alejandro; Arroyave, Frank A; Ballester, Pablo

    2016-02-18

    Heterodimeric capsules self-assembled from tetraurea calix[4]pyrrole and tetraurea calix[4]arene provide unique molecular containers for the organised inclusion of small polar molecules. By inserting stimuli-responsive groups (azobenzene) in the heterocapsule structure, we are able to modify the equilibrium state of the system or the exchange between different host-guest assemblies in a reversible manner.

  1. Polarization optics for out-of-plane light trajectories: GRIN lenses and optical fibers

    Science.gov (United States)

    Tentori, Diana; Trevino-Martinez, Fernando; Ayala-Diaz, Cesar; Camacho, Javier; Mendieta-Jimenez, Francisco J.

    2001-08-01

    The volution of the state of polarization along an out-of- plane trajectory has been widely studied for monomode optical fibers. To demonstrate the validity of our proposal we compare the results predicted by our model with experimental result obtained for helically wound optical fibers and the conoscopic patterns obtained for GRIN lenses when oblique illumination is used.

  2. Shadows and cavities in protoplanetary disks: HD 163296, HD 141569A, and HD 150193A in polarized light

    Science.gov (United States)

    Garufi, A.; Quanz, S. P.; Schmid, H. M.; Avenhaus, H.; Buenzli, E.; Wolf, S.

    2014-08-01

    Context. The morphological evolution of dusty disks around young (a few Myr old) stars is pivotal for a better understanding of planet formation. Since both dust grains and the global disk geometry evolve on short timescales, high-resolution imaging of a sample of objects may provide important indications about this evolution. Aims: We enlarge the sample of protoplanetary disks imaged in polarized light with high-resolution imaging (≲0.2″) by observing the Herbig Ae/Be stars HD 163296, HD 141569A, and HD 150193A. We combine our data with previous datasets to understand the larger context of their morphology. Methods: Polarimetric differential imaging is an attractive technique with which to image at near-IR wavelengths a significant fraction of the light scattered by the circumstellar material. The unpolarized stellar light is canceled out by combining two simultaneous orthogonal polarization states. This allowed us to achieve an inner working angle and an angular resolution as low as ~0.1″. Results: We report a weak detection of the disk around HD 163296 in the H and KS bands. The disk is resolved as a broken ring structure with a significant surface brightness drop inward of 0.6″. No sign of extended polarized emission is detected from the disk around HD 141569A and HD 150193A. Conclusions: We propose that the absence of scattered light in the inner 0.6″ around HD 163296 and the non-detection of the disk around HD 150193A may be due to similar geometric factors. Since these disks are known to be flat or only moderately flared, self-shadowing by the disk inner wall is the favored explanation. We show that the polarized brightness of a number of disks is indeed related to their flaring angle. Other scenarios (such as dust grain growth or interaction with icy molecules) are also discussed. On the other hand, the non-detection of HD 141569A is consistent with previous datasets that revealed a huge cavity in the dusty disk. Based on observations collected at

  3. Quantitatively characterizing the microstructural features of breast ductal carcinoma tissues in different progression stages by Mueller matrix microscope.

    Science.gov (United States)

    Dong, Yang; Qi, Ji; He, Honghui; He, Chao; Liu, Shaoxiong; Wu, Jian; Elson, Daniel S; Ma, Hui

    2017-08-01

    Polarization imaging has been recognized as a potentially powerful technique for probing the microstructural information and optical properties of complex biological specimens. Recently, we have reported a Mueller matrix microscope by adding the polarization state generator and analyzer (PSG and PSA) to a commercial transmission-light microscope, and applied it to differentiate human liver and cervical cancerous tissues with fibrosis. In this paper, we apply the Mueller matrix microscope for quantitative detection of human breast ductal carcinoma samples at different stages. The Mueller matrix polar decomposition and transformation parameters of the breast ductal tissues in different regions and at different stages are calculated and analyzed. For more quantitative comparisons, several widely-used image texture feature parameters are also calculated to characterize the difference in the polarimetric images. The experimental results indicate that the Mueller matrix microscope and the polarization parameters can facilitate the quantitative detection of breast ductal carcinoma tissues at different stages.

  4. Compact plane illumination plugin device to enable light sheet fluorescence imaging of multi-cellular organisms on an inverted wide-field microscope.

    Science.gov (United States)

    Guan, Zeyi; Lee, Juhyun; Jiang, Hao; Dong, Siyan; Jen, Nelson; Hsiai, Tzung; Ho, Chih-Ming; Fei, Peng

    2016-01-01

    We developed a compact plane illumination plugin (PIP) device which enabled plane illumination and light sheet fluorescence imaging on a conventional inverted microscope. The PIP device allowed the integration of microscope with tunable laser sheet profile, fast image acquisition, and 3-D scanning. The device is both compact, measuring approximately 15 by 5 by 5 cm, and cost-effective, since we employed consumer electronics and an inexpensive device molding method. We demonstrated that PIP provided significant contrast and resolution enhancement to conventional microscopy through imaging different multi-cellular fluorescent structures, including 3-D branched cells in vitro and live zebrafish embryos. Imaging with the integration of PIP greatly reduced out-of-focus contamination and generated sharper contrast in acquired 2-D plane images when compared with the stand-alone inverted microscope. As a result, the dynamic fluid domain of the beating zebrafish heart was clearly segmented and the functional monitoring of the heart was achieved. Furthermore, the enhanced axial resolution established by thin plane illumination of PIP enabled the 3-D reconstruction of the branched cellular structures, which leads to the improvement on the functionality of the wide field microscopy.

  5. Scanning Color Laser Microscope

    Science.gov (United States)

    Awamura, D.; Ode, T.; Yonezawa, M.

    1988-01-01

    A confocal color laser microscope which utilizes a three color laser light source (Red: He-Ne, Green: Ar, Blue: Ar) has been developed and is finding useful applications in the semiconductor field. The color laser microscope, when compared to a conventional microscope, offers superior color separation, higher resolution, and sharper contrast. Recently some new functions including a Focus Scan Memory, a Surface Profile Measurement System, a Critical Dimension Measurement system (CD) and an Optical Beam Induced Current Function (OBIC) have been developed for the color laser microscope. This paper will discuss these new features.

  6. Unexpected attraction of polarotactic water-leaving insects to matt black car surfaces: mattness of paintwork cannot eliminate the polarized light pollution of black cars.

    Directory of Open Access Journals (Sweden)

    Miklos Blaho

    Full Text Available The horizontally polarizing surface parts of shiny black cars (the reflection-polarization characteristics of which are similar to those of water surfaces attract water-leaving polarotactic insects. Thus, shiny black cars are typical sources of polarized light pollution endangering water-leaving insects. A new fashion fad is to make car-bodies matt black or grey. Since rough (matt surfaces depolarize the reflected light, one of the ways of reducing polarized light pollution is to make matt the concerned surface. Consequently, matt black/grey cars may not induce polarized light pollution, which would be an advantageous feature for environmental protection. To test this idea, we performed field experiments with horizontal shiny and matt black car-body surfaces laid on the ground. Using imaging polarimetry, in multiple-choice field experiments we investigated the attractiveness of these test surfaces to various water-leaving polarotactic insects and obtained the following results: (i The attractiveness of black car-bodies to polarotactic insects depends in complex manner on the surface roughness (shiny, matt and species (mayflies, dolichopodids, tabanids. (ii Non-expectedly, the matt dark grey car finish is much more attractive to mayflies (being endangered and protected in many countries than matt black finish. (iii The polarized light pollution of shiny black cars usually cannot be reduced with the use of matt painting. On the basis of these, our two novel findings are that (a matt car-paints are highly polarization reflecting, and (b these matt paints are not suitable to repel polarotactic insects. Hence, the recent technology used to make matt the car-bodies cannot eliminate or even can enhance the attractiveness of black/grey cars to water-leaving insects. Thus, changing shiny black car painting to matt one is a disadvantageous fashion fad concerning the reduction of polarized light pollution of black vehicles.

  7. Unexpected attraction of polarotactic water-leaving insects to matt black car surfaces: mattness of paintwork cannot eliminate the polarized light pollution of black cars.

    Science.gov (United States)

    Blaho, Miklos; Herczeg, Tamas; Kriska, Gyorgy; Egri, Adam; Szaz, Denes; Farkas, Alexandra; Tarjanyi, Nikolett; Czinke, Laszlo; Barta, Andras; Horvath, Gabor

    2014-01-01

    The horizontally polarizing surface parts of shiny black cars (the reflection-polarization characteristics of which are similar to those of water surfaces) attract water-leaving polarotactic insects. Thus, shiny black cars are typical sources of polarized light pollution endangering water-leaving insects. A new fashion fad is to make car-bodies matt black or grey. Since rough (matt) surfaces depolarize the reflected light, one of the ways of reducing polarized light pollution is to make matt the concerned surface. Consequently, matt black/grey cars may not induce polarized light pollution, which would be an advantageous feature for environmental protection. To test this idea, we performed field experiments with horizontal shiny and matt black car-body surfaces laid on the ground. Using imaging polarimetry, in multiple-choice field experiments we investigated the attractiveness of these test surfaces to various water-leaving polarotactic insects and obtained the following results: (i) The attractiveness of black car-bodies to polarotactic insects depends in complex manner on the surface roughness (shiny, matt) and species (mayflies, dolichopodids, tabanids). (ii) Non-expectedly, the matt dark grey car finish is much more attractive to mayflies (being endangered and protected in many countries) than matt black finish. (iii) The polarized light pollution of shiny black cars usually cannot be reduced with the use of matt painting. On the basis of these, our two novel findings are that (a) matt car-paints are highly polarization reflecting, and (b) these matt paints are not suitable to repel polarotactic insects. Hence, the recent technology used to make matt the car-bodies cannot eliminate or even can enhance the attractiveness of black/grey cars to water-leaving insects. Thus, changing shiny black car painting to matt one is a disadvantageous fashion fad concerning the reduction of polarized light pollution of black vehicles.

  8. Light polarization sensitive photodetectors with m- and r-plane homoepitaxial ZnO/ZnMgO quantum wells

    Energy Technology Data Exchange (ETDEWEB)

    Tabares, G.; Hierro, A., E-mail: adrian.hierro@upm.es; Lopez-Ponce, M.; Muñoz, E. [ISOM and Dpto. Ingeniería Electrónica, Universidad Politécnica de Madrid, Ciudad Universitaria s/n, 28040 Madrid (Spain); Vinter, B.; Chauveau, J.-M. [CRHEA-CNRS, Av. B. Gregory, 06560 Valbonne (France); University of Nice Sophia Antipolis, Parc Valrose, 06102 Nice cedex 2 (France)

    2015-02-09

    Homoepitaxial ZnO/(Zn,Mg)O multiple quantum wells (MQWs) grown with m- and r-plane orientations are used to demonstrate Schottky photodiodes sensitive to the polarization state of light. In both orientations, the spectral photoresponse of the MQW photodiodes shows a sharp excitonic absorption edge at 3.48 eV with a very low Urbach tail, allowing the observation of the absorption from the A, B and C excitonic transitions. The absorption edge energy is shifted by ∼30 and ∼15 meV for the m- and r-plane MQW photodiodes, respectively, in full agreement with the calculated polarization of the A, B, and C excitonic transitions. The best figures of merit are obtained for the m-plane photodiodes, which present a quantum efficiency of ∼11%, and a specific detectivity D* of ∼6.4 × 10{sup 10} cm Hz{sup 1/2}/W. In these photodiodes, the absorption polarization sensitivity contrast between the two orthogonal in-plane axes yields a maximum value of (R{sub ⊥}/R{sub ||}){sub max} ∼ 9.9 with a narrow bandwidth of ∼33 meV.

  9. Electron-spin filter and polarizer in a standing light wave

    Science.gov (United States)

    Ahrens, Sven

    2017-11-01

    We demonstrate the theoretical feasibility of spin-dependent diffraction and spin polarization of an electron in two counterpropagating, circularly polarized laser beams. The spin dynamics appears in a two-photon process of the Kapitza-Dirac effect in the Bragg regime. We show the spin dependence of the diffraction process by comparison of the time evolution of spin-up and spin-down electrons in a relativistic quantum simulation. We further discuss the spin properties of the scattering by studying an analytically approximated solution of the time-evolution matrix. A classification scheme in terms of unitary or nonunitary propagation matrices is used for establishing a generalized and spin-independent description of the spin properties in the diffraction process.

  10. Forward scattering of polarized light from a turbid slab: theory and Monte Carlo simulations.

    Science.gov (United States)

    Otsuki, Soichi

    2016-12-20

    It is proved that if reciprocity and mirror symmetry hold for single scattering by a particle, they also hold for multiple scattering in turbid slab media. Monte Carlo simulations generate a reduced effective Mueller matrix for forward scattering, which satisfies reciprocity and mirror symmetry, but satisfies only reciprocity if the medium contains chiral components. The scattering matrix was factorized by using the Lu-Chipman polar decomposition, which affords the polarization parameters as a function of the radial distance from the center. The depolarization coefficients decrease with increasing distance, whereas the scattering-induced linear diattenuation and retardance become larger in the middle-distance range. The optical rotation for a chiral medium increases with increasing distance.

  11. Reflecting metallic metasurfaces designed with stochastic optimization as waveplates for manipulating light polarization

    Science.gov (United States)

    Haberko, Jakub; Wasylczyk, Piotr

    2018-03-01

    We demonstrate that a stochastic optimization algorithm with a properly chosen, weighted fitness function, following a global variation of parameters upon each step can be used to effectively design reflective polarizing optical elements. Two sub-wavelength metallic metasurfaces, corresponding to broadband half- and quarter-waveplates are demonstrated with simple structure topology, a uniform metallic coating and with the design suited for the currently available microfabrication techniques, such as ion milling or 3D printing.

  12. Periodic array of quantum rings strongly coupled to circularly polarized light as a topological insulator

    Science.gov (United States)

    Kozin, V. K.; Iorsh, I. V.; Kibis, O. V.; Shelykh, I. A.

    2018-01-01

    We demonstrate theoretically that a strong high-frequency circularly polarized electromagnetic field can turn a two-dimensional periodic array of interconnected quantum rings into a topological insulator. The elaborated approach is applicable to calculate and analyze the electron energy spectrum of the array, the energy spectrum of the edge states, and the corresponding electronic densities. As a result, the present theory paves the way to optical control of the topological phases in ring-based mesoscopic structures.

  13. On the role of strong gravity in polarization from scattering of light in relativistic flows

    Czech Academy of Sciences Publication Activity Database

    Horák, Jiří; Karas, Vladimír

    2006-01-01

    Roč. 365, č. 3 (2006), s. 813-826 ISSN 0035-8711 R&D Projects: GA MŠk(CZ) LC06014; GA AV ČR(CZ) IAA300030510; GA ČR GA205/03/0902 Institutional research plan: CEZ:AV0Z10030501 Keywords : polarization * black hole physics * relativity Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics Impact factor: 5.057, year: 2006

  14. Conjugation of both on-axis and off-axis light in Nipkow disk confocal microscope to increase availability of incoherent light source.

    Science.gov (United States)

    Saito, Kenta; Arai, Yoshiyuki; Zhang, Jize; Kobayashi, Kentaro; Tani, Tomomi; Nagai, Takeharu

    2011-01-01

    Laser-scanning confocal microscopy has been employed for exploring structures at subcellular, cellular and tissue level in three dimensions. To acquire the confocal image, a coherent light source, such as laser, is generally required in conventional single-point scanning microscopy. The illuminating beam must be focused onto a small spot with diffraction-limited size, and this determines the spatial resolution of the microscopy system. In contrast, multipoint scanning confocal microscopy using a Nipkow disk enables the use of an incoherent light source. We previously demonstrated successful application of a 100 W mercury arc lamp as a light source for the Yokogawa confocal scanner unit in which a microlens array was coupled with a Nipkow disk to focus the collimated incident light onto a pinhole (Saito et al., Cell Struct. Funct., 33: 133-141, 2008). However, transmission efficiency of incident light through the pinhole array was low because off-axis light, the major component of the incident light, was blocked by the non-aperture area of the disk. To improve transmission efficiency, we propose an optical system in which off-axis light is able to be transmitted through pinholes surrounding the pinhole located on the optical axis of the collimator lens. This optical system facilitates the use of not only the on-axis but also the off-axis light such that the available incident light is considerably improved. As a result, we apply the proposed system to high-speed confocal and multicolor imaging both with a satisfactory signal-to-noise ratio.

  15. Influence of synapsin I on synaptic vesicles: an analysis by force-volume mode of the atomic force microscope and dynamic light scattering.

    Science.gov (United States)

    Awizio, Ann-Katrin; Onofri, Franco; Benfenati, Fabio; Bonaccurso, Elmar

    2007-08-01

    Synaptic vesicles (SVs) are small neuronal organelles that store neurotransmitters and release them by exocytosis into the synaptic cleft for signal transmission between nerve cells. They consist of a highly curved membrane composed of different lipids containing several proteins with specific functions. A family of abundant extrinsic SV proteins, the synapsins, interact with SV proteins and phospholipids and play an important role in the regulation of SV trafficking and stability. We investigated the interactions of one these proteins with the SV membrane using atomic force microscope and dynamic light scattering. We examined SVs isolated from rat forebrain both under native conditions and after depletion of endogenous synapsin I. We used the atomic force microscope in two modes: imaging mode for characterizing the shape and size of SVs, and force-volume mode for characterizing their stiffness. Synapsin-depleted SVs were larger in size and showed a higher tendency to aggregate than native vesicles, although their stiffness was not significantly different. Because synapsins are believed to cross-link SV to each other and to the actin cytoskeleton, we also measured the SV aggregation kinetics induced by synapsin I by dynamic light scattering and atomic force microscopy and found that the addition of synapsin I promotes a rapid aggregation of SVs. The data indicate that synapsin directly affects SV stability and aggregation state and support the physiological role of synapsins in the assembly and regulation of SV pools within nerve terminals.

  16. [A non-invasive glucose measurement method based on orthogonal twin-polarized light and its pilot experimental investigation].

    Science.gov (United States)

    Wang, Hong; Wu, Baoming; Liu, Ding

    2010-04-01

    In order to overcome the existing shortcomings of the non-invasive blood glucose polarized light measurement methods of optical heterodyne detection and direct detection, we present in this paper a new orthogonal twin-polarized light (OTPL) non-invasive blood glucose measurement method, which converts the micro-angle rotated by an optical active substance such as glucose to the energy difference of OTPL, amplifies the signals by the high-sensitivity lock-in amplifier made of relevant principle, controls Faraday coil current to compensate the changes in deflection angle caused by blood glucose, and makes use of the linear relationship between blood glucose concentration and Faraday coil current to calculate blood glucose concentration. In our comparative experiment using the data measured by LX-20 automatic biochemical analyzer as a standard, a 0.9777 correlation coefficient is obtained in glucose concentration experiment, and a 0.952 in serum experiment. The result shows that this method has higher detection sensitivity and accuracy and lays a foundation for the development of practical new type of non-invasive blood glucose tester for diabetic patients.

  17. Bichromatic coherent random lasing from dye-doped polymer stabilized blue phase liquid crystals controlled by pump light polarization

    Science.gov (United States)

    Wang, Lei; Wang, Meng; Yang, Mingchao; Shi, Li-Jie; Deng, Luogen; Yang, Huai

    2016-09-01

    In this paper, we investigate the bichromatic coherent random lasing actions from the dye-doped polymer stabilized blue phase liquid crystals. Two groups of lasing peaks, of which the full widith at half maximum is about 0.3 nm, are clearly observed. The shorter- and longer-wavelength modes are associated with the excitation of the single laser dye (DCM) monomers and dimers respectively. The experimental results show that the competition between the two groups of the lasing peaks can be controlled by varying the polarization of the pump light. When the polarization of the pump light is rotated from 0° to 90°, the intensity of the shorter-wavelength lasing peak group reduces while the intensity of the longer-wavelength lasing peak group increases. In addition, a red shift of the longer-wavelength modes is also observed and the physical mechanisms behind the red-shift phenomenon are discussed. Project supported by the National Natural Science Foundation of China (Grant Nos. 11474021 and 51333001), the Key Program for International S&T Cooperation Projects of China (Grant No. 2013DFB50340), the Issues of Priority Development Areas of the Research Fund for the Doctoral Program of Higher Education of China (Grant No. 20120001130005), and the Key (Key Grant) Project of Chinese Ministry of Education (Grant No. 313002).

  18. Real-time scattered light dark-field microscopic imaging of the dynamic degradation process of sodium dimethyldithiocarbamate.

    Science.gov (United States)

    Lei, Gang; Gao, Peng Fei; Liu, Hui; Huang, Cheng Zhi

    2015-12-28

    Single nanoparticle analysis (SNA) technique with the aid of a dark-field microscopic imaging (iDFM) technique has attracted wide attention owing to its high sensitivity. Considering that the degradation of pesticides can bring about serious problems in food and the environment, and that the real-time monitoring of the dynamic degradation process of pesticides can help understand and define their degradation mechanisms, herein we real-time monitored the decomposition dynamics of sodium dimethyldithiocarbamate (NaDDC) under neutral and alkaline conditions by imaging single silver nanoparticles (AgNPs) under a dark-field microscope (DFM); the localized surface plasmon resonance (LSPR) scattering signals were measured at a single nanoparticle level. As a result, the chemical mechanism of the degradation of NaDDC under neutral and alkaline conditions was proposed, and the inhibition effects of metal ions including Zn(II) and Cu(II) were investigated in order to understand the decomposition process in different environments. It was found that Cu(II) forms the most stable complex with NaDDC with a stoichiometric ratio of 1 : 2, which greatly reduces the toxicity.

  19. 3D-surface reconstruction method for diffuse optical tomography phantoms and tissues using structured and polarized light

    Science.gov (United States)

    Baum, K.; Hartmann, R.; Bischoff, T.; Himmelreich, F.; Heverhagen, J. T.

    2011-07-01

    In recent years optical methods became increasingly popular for pre-clinical research and small animal imaging. One main field in biomedical optics research is the diffuse optical tomography (DOT). Many new systems were invented for small animal imaging and breast cancer detection. In combination with the progress in the development of optical markers, optical detectors and near infrared light sources, these new systems have become a formidable source of information. Most of the systems detect the transmitted light which passes through an object and one observes the intensity variations on the detector side. The biggest challenge for all diffuse optical tomography systems is the enormous scattering of light in tissues and tissue-like phantoms resulting in loss of image information. Many systems work with contact gels and optical fibers that have direct contact with the object to neglect the light path between surface and detector. Highly developed mathematic models and reconstruction algorithms based on FEM and Monte Carlo simulations describe the light transport inside tissues and determine differences in absorption and scattering coefficients inside. The proposed method allows a more exact description of the orientation of surface elements from semi-transparent objects towards the detector. Using Polarization Difference Imaging (PDI) in combination with structured light 3D-scanning, it is possible to separate information from the surface from that of the subsurface. Thus, the actual surface shape can be determined. Furthermore, overlaying byproducts caused by inter-reflections and multiple scattering can be filtered from the basic image information with this method. To enhance the image quality, the intensity dispersion between surface and camera is calculated and the creation of 3D-FEM-meshes simplified.

  20. Development of olfactory epithelium and associated structures in the green iguana, Iguana iguana—light and scanning electron microscopic study

    Directory of Open Access Journals (Sweden)

    Olga Sapoznikov

    2016-12-01

    Full Text Available The ontogenesis of the nasal cavity has been described in many mammalian species. The situation is different with reptiles, despite the fact that they have become relatively common as pets. In this study we focused on the ontogenesis of the olfactory epithelium, as well as other types of epithelia in the nasal cavity of pre-hatched green iguanas (Iguana iguana. Collection of samples began from day 67 of incubation and continued every four days until hatching. Microscopic examination revealed that significant morphological changes in the nasal cavity began approximately at day 91 of ontogenesis. Approximately at this same stage, the nasal cavity epithelium began to differentiate. The cavity was divided into two compartments by a cartilaginous disc. The ventral compartment bulged rostrally and eventually opened up into the external environment. Three clearly demarcated areas of epithelium in the nasal cavity were visible at day 107.

  1. Development of olfactory epithelium and associated structures in the green iguana, Iguana iguana-light and scanning electron microscopic study.

    Science.gov (United States)

    Sapoznikov, Olga; Cizek, Petr; Tichy, Frantisek

    2016-01-01

    The ontogenesis of the nasal cavity has been described in many mammalian species. The situation is different with reptiles, despite the fact that they have become relatively common as pets. In this study we focused on the ontogenesis of the olfactory epithelium, as well as other types of epithelia in the nasal cavity of pre-hatched green iguanas ( Iguana iguana ). Collection of samples began from day 67 of incubation and continued every four days until hatching. Microscopic examination revealed that significant morphological changes in the nasal cavity began approximately at day 91 of ontogenesis. Approximately at this same stage, the nasal cavity epithelium began to differentiate. The cavity was divided into two compartments by a cartilaginous disc. The ventral compartment bulged rostrally and eventually opened up into the external environment. Three clearly demarcated areas of epithelium in the nasal cavity were visible at day 107.

  2. Development of olfactory epithelium and associated structures in the green iguana, Iguana iguana—light and scanning electron microscopic study

    Science.gov (United States)

    Cizek, Petr; Tichy, Frantisek

    2016-01-01

    The ontogenesis of the nasal cavity has been described in many mammalian species. The situation is different with reptiles, despite the fact that they have become relatively common as pets. In this study we focused on the ontogenesis of the olfactory epithelium, as well as other types of epithelia in the nasal cavity of pre-hatched green iguanas (Iguana iguana). Collection of samples began from day 67 of incubation and continued every four days until hatching. Microscopic examination revealed that significant morphological changes in the nasal cavity began approximately at day 91 of ontogenesis. Approximately at this same stage, the nasal cavity epithelium began to differentiate. The cavity was divided into two compartments by a cartilaginous disc. The ventral compartment bulged rostrally and eventually opened up into the external environment. Three clearly demarcated areas of epithelium in the nasal cavity were visible at day 107. PMID:27920949

  3. Textile solar light collectors based on models for polar bear hair

    Energy Technology Data Exchange (ETDEWEB)

    Bahners, Thomas; Schlosser, Uwe; Schollmeyer, Eckhard [Deutsches Textilforschungszentrum Nord-West e.V., Adlerstr. 1, D-47798 Krefeld (Germany); Gutmann, Rainer [Institut fuer Textilchemie und Chemiefasern, Koerschtalstr. 26, D-73770 Denkendorf (Germany)

    2008-12-15

    Concepts of technical fibers following models for the polar bear hair to be used for textile solar collectors are discussed. The approach to coat fibers with a thin layer into which fluorescent dyestuff was dispersed was studied experimentally. Modified fibers made of different polymers were characterized with respect to optical properties relevant for the bionic model. In the case of poly(methylmethacrylate) fibers, the envisaged effect could be achieved to high efficiency. The optical performance could be enhanced by ultrasonic dispersion of the dyestuff in the coating matrix. The effect is less significant in semi-crystalline fibers such as poly(ethylene terephthalate), which is attributed to diffuse scattering. (author)

  4. THE ORIENTATION OF THE E-VECTOR OF LINEARLY POLARIZED LIGHT DOES NOT AFFECT THE BEHAVIOUR OF THE PIGEON COLUMBA LIVIA

    Science.gov (United States)

    Coemans; Hzn; Nuboer

    1994-06-01

    Orientation with reference to the time-compensated sun-azimuth compass has been established for the homing pigeon Columba livia. Previous qualitative studies claim that pigeons are sensitive to the orientation of a polarizer and it has been suggested that these animals are able to use sky-light polarization as an indirect reference to the sun's position when the latter is shielded from view. We report experiments which were undertaken to quantify the sensitivity of the homing pigeon to the orientation of linearly polarized light. The results of our initial experiments suggested that the animals responded to secondary cues. Further experiments were carried out to avoid such artefacts. Under circumstances where secondary cues were rigorously avoided, we were, however, not able to demonstrate any directional response that was caused by the E-vector orientation of the illumination. These results throw doubt on the suggested polarization-sensitivity of birds in general.

  5. Polarized light for horizontal incidence and reflection by plane-parallel atmospheres

    NARCIS (Netherlands)

    Hovenier, J.W.; Stam, D.M.

    2007-01-01

    We show that the intensity vector of light reflected by a plane-parallel atmosphere is discontinuous if the directions of incidence and reflection are both horizontal. An exact expression describing the discontinuity is presented. This expression shows that the discontinuity is only due to first

  6. influence of polar solvents on the enhancement of light-ends

    African Journals Online (AJOL)

    user

    Unfortunately, light crude oil reserve is fast depleting [1]. This is perhaps one of the ... reduced to a Crude Dispersion System (CDS), the smallest of it being referred to as .... Table 3: Comparison of the yields of fractional cuts obtained by TBP distillation crude and the various Ethanol blends. Fractional cut, 0C. Pure crude 0%.

  7. Light-directing omnidirectional circularly polarized reflection from liquid-crystal droplets.

    Science.gov (United States)

    Fan, Jing; Li, Yannian; Bisoyi, Hari Krishna; Zola, Rafael S; Yang, Deng-Ke; Bunning, Timothy J; Weitz, David A; Li, Quan

    2015-02-09

    Constructing and tuning self-organized three-dimensional (3D) superstructures with tailored functionality is crucial in the nanofabrication of smart molecular devices. Herein we fabricate a self-organized, phototunable 3D photonic superstructure from monodisperse droplets of one-dimensional cholesteric liquid crystal (CLC) containing a photosensitive chiral molecular switch with high helical twisting power. The droplets are obtained by a glass capillary microfluidic technique by dispersing into PVA solution that facilitates planar anchoring of the liquid-crystal molecules at the droplet surface, as confirmed by the observation of normal incidence selective circular polarized reflection in all directions from the core of individual droplet. Photoirradiation of the droplets furnishes dynamic reflection colors without thermal relaxation, whose wavelength can be tuned reversibly by variation of the irradiation time. The results provided clear evidence on the phototunable reflection in all directions. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. GLE and Sub-GLE Redefinition in the Light of High-Altitude Polar Neutron Monitors

    Science.gov (United States)

    Poluianov, S. V.; Usoskin, I. G.; Mishev, A. L.; Shea, M. A.; Smart, D. F.

    2017-11-01

    The conventional definition of ground-level enhancement (GLE) events requires a detection of solar energetic particles (SEP) by at least two differently located neutron monitors. Some places are exceptionally well suitable for ground-based detection of SEP - high-elevation polar regions with negligible geomagnetic and reduced atmospheric energy/rigidity cutoffs. At present, there are two neutron-monitor stations in such locations on the Antarctic plateau: SOPO/SOPB (at Amundsen-Scott station, 2835 m elevation), and DOMC/DOMB (at Concordia station, 3233 m elevation). Since 2015, when the DOMC/DOMB station started continuous operation, a relatively weak SEP event that was not detected by sea-level neutron-monitor stations was registered by both SOPO/SOPB and DOMC/DOMB, and it was accordingly classified as a GLE. This would lead to a distortion of the homogeneity of the historic GLE list and the corresponding statistics. To address this issue, we propose to modify the GLE definition so that it maintains the homogeneity: A GLE event is registered when there are near-time coincident and statistically significant enhancements of the count rates of at least two differently located neutron monitors, including at least one neutron monitor near sea level and a corresponding enhancement in the proton flux measured by a space-borne instrument(s). Relatively weak SEP events registered only by high-altitude polar neutron monitors, but with no response from cosmic-ray stations at sea level, can be classified as sub-GLEs.

  9. Noise Reduction Method for Quantifying Nanoparticle Light Scattering in Low Magnification Dark-Field Microscope Far-Field Images.

    Science.gov (United States)

    Sun, Dali; Fan, Jia; Liu, Chang; Liu, Yang; Bu, Yang; Lyon, Christopher J; Hu, Ye

    2016-12-20

    Nanoparticles have become a powerful tool for cell imaging and biomolecule, cell and protein interaction studies, but are difficult to rapidly and accurately measure in most assays. Dark-field microscope (DFM) image analysis approaches used to quantify nanoparticles require high-magnification near-field (HN) images that are labor intensive due to a requirement for manual image selection and focal adjustments needed when identifying and capturing new regions of interest. Low-magnification far-field (LF) DFM imagery is technically simpler to perform but cannot be used as an alternate to HN-DFM quantification, since it is highly sensitive to surface artifacts and debris that can easily mask nanoparticle signal. We now describe a new noise reduction approach that markedly reduces LF-DFM image artifacts to allow sensitive and accurate nanoparticle signal quantification from LF-DFM images. We have used this approach to develop a "Dark Scatter Master" (DSM) algorithm for the popular NIH image analysis program ImageJ, which can be readily adapted for use with automated high-throughput assay analyses. This method demonstrated robust performance quantifying nanoparticles in different assay formats, including a novel method that quantified extracellular vesicles in patient blood sample to detect pancreatic cancer cases. Based on these results, we believe our LF-DFM quantification method can markedly decrease the analysis time of most nanoparticle-based assays to impact both basic research and clinical analyses.

  10. Stereo photograph of atomic arrangement by circularly-polarized-light two-dimensional photoelectron spectroscopy

    CERN Document Server

    Daimon, H

    2003-01-01

    A stereo photograph of atomic arrangement was obtained for the first time. The stereo photograph was displayed directly on the screen of display-type spherical-mirror analyzer without any computer-aided conversion process. This stereo photography was realized taking advantage of the phenomenon of circular dichroism in photoelectron angular distribution due to the reversal of orbital angular momentum of photoelectrons. The azimuthal shifts of forward focusing peaks in a photoelectron angular distribution pattern taken with left and right helicity light in a special arrangement are the same as the parallaxes in a stereo view of atoms. Hence a stereoscopic recognition of three-dimensional atomic arrangement is possible, when the left eye and the right eye respectively view the two images obtained by left and right helicity light simultaneously.

  11. Photo double ionization of helium 100 eV and 450 eV above threshold: I. Linearly polarized light

    International Nuclear Information System (INIS)

    Knapp, A; Kheifets, A; Bray, I; Weber, Th; Landers, A L; Schoessler, S; Jahnke, T; Nickles, J; Kammer, S; Jagutzki, O; Schmidt, L Ph H; Schoeffler, M; Osipov, T; Prior, M H; Schmidt-Boecking, H; Cocke, C L; Doerner, R

    2005-01-01

    We present a joint experimental and theoretical study for the fully differential cross section of the photo double ionization (PDI) of helium with linearly polarized light at the excess energies E exc = 100 eV and 450 eV above the threshold. The fully differential cross section is obtained by measuring the three-dimensional momentum vectors of one electron and the He 2+ ion in coincidence using the COLTRIMS method. We give an overview of the momentum distribution of the three-body continuum 100 eV above the threshold. We show angular distributions for both electrons for various energy sharings at E exc = 100 eV and 450 eV. The experimental results are well reproduced by a set of convergent close-coupling (CCC) calculations

  12. Determining the molecular origin of radiation damage/enhancement in electro-optic polymeric materials through polarized light microscopy

    Science.gov (United States)

    Perez-Moreno, Javier

    2014-09-01

    Previous studies on the radiation effects upon polymer and polymer-based photonic materials suggest that the radiation resistance of the material is heavily dependent on the choice of polymer-host and guest-chromophore. The best results to date have been achieved with electro optic polymeric materials based on CLD1 doped in APC, which has resulted in improved performance at the device level upon gamma-ray irradiation at moderate doses. Still, our understanding of the physical mechanisms behind the enhancement of the performance is unclear. In this paper, we discuss how polarized light microscopy could be used as a means to quantify the effect of the different physical parameters that influence the optical response of electro-optic polymeric thin film samples.

  13. The influence of iron and light on net community production in the Subantarctic and Polar Frontal Zones

    Science.gov (United States)

    Cassar, N.; Difiore, P. J.; Barnett, B. A.; Bender, M. L.; Bowie, A. R.; Tilbrook, B.; Petrou, K.; Westwood, K. J.; Wright, S. W.; Lefevre, D.

    2011-02-01

    The roles of iron and light in controlling biomass and primary productivity are clearly established in the Southern Ocean. However, their influence on net community production (NCP) and carbon export remains to be quantified. To improve our understanding of NCP and carbon export production in the Subantarctic Zone (SAZ) and the northern reaches of the Polar Frontal Zone (PFZ), we conducted continuous onboard determinations of NCP as part of the Sub-Antarctic Sensitivity to Environmental Change (SAZ-Sense) study, which occurred in January-February 2007. Biological O2 supersaturation was derived from measuring O2/Ar ratios by equilibrator inlet mass spectrometry. Based on these continuous measurements, NCP during the austral summer 2007 in the Australian SAZ was approximately 43 mmol O2 m-2 d-1. NCP showed significant spatial variability, with larger values near the Subtropical front, and a general southward decrease. For shallower mixed layers (export from the Southern Ocean mixed layer.

  14. Solid polymer films exhibiting handedness-switchable, full-color-tunable selective reflection of circularly polarized light.

    Science.gov (United States)

    Nagata, Yuuya; Takagi, Keisuke; Suginome, Michinori

    2014-07-16

    Poly(quinoxaline-2,3-diyl)s bearing (S)-2-methylbutyl, n-butyl, and 8-chlorooctyl groups as side chains were synthesized to fabricate dry solid polymer thin films. These films exhibited selective reflection of right-handed circular polarized light (CPL) in the visible region after annealing in CHCl3 vapor at room temperature. The handedness of reflected CPL was inverted to the left after annealing in 1,2-dichloroethane vapor. It was also found that the color of a particular single film along with the handedness of reflected CPL were fully tuned reversibly, upon exposure of the film to the vapor of various mixtures of chloroform and 1,2-dichloroethane in different ratios.

  15. Analysis of peripheral thermal damage after laser irradiation of dentin using polarized light microscopy and synchrotron radiation infrared spectromicroscopy

    Science.gov (United States)

    Dela Rosa, Alfredo; Sarma, Anupama V.; Le, Charles Q.; Jones, Robert S.; Fried, Daniel

    2004-05-01

    It is necessary to minimize peripheral thermal damage during laser irradiation, since thermal damage to collagen and mineral compromises the bond strength to restorative materials in dentin and inhibits healing and osteointegration in bone. The overall objective of this study was to test the hypothesis that lasers resonant to the specific absorption of water, collagen, and hydroxyapatite with pulse durations less than the thermal relaxation times at each respective laser wavelength will efficiently remove dentin with minimal peripheral thermal damage. Precise incisions were produced in 3 x 3 mm2 blocks of human dentin using CO2 (9.6 μm), Er:YSGG (2.79 μm), and Nd:YAG (355 nm) lasers with and without a computer controlled water spray. Polarization-sensitive optical coherence tomography was used to obtain optical cross-sections of each incision to determine the rate and efficiency of ablation. The peripheral thermal damage zone around each incision was analyzed using polarized light microscopy (PLM) and Synchrotron-Radiation Fourier Transform Infrared Spectro-microscopy (SR-FTIR). Thermally induced chemical changes to both mineral and the collagen matrix was observed with SR-FTIR with a 10-μm spatial resolution and those changes were correlated with optical changes observed with PLM. Minimal (alveolar bone.

  16. Distributions of /sup 35/S-sulfate and /sup 3/H-glucosamine in the angular region of the hamster: light and electron microscopic autoradiography

    Energy Technology Data Exchange (ETDEWEB)

    Ohnishi, Y.; Taniguchi, Y.

    1983-06-01

    The distribution of /sup 35/S-sulfate and /sup 3/H-glucosamine in the angular region of the hamster was studied by light and electron microscopic autoradiography following intraperitoneal injection of these compounds to hamsters. Exposed silver grains of /sup 35/S-sulfate were concentrated in the trabecular meshwork, sclera, and cornea, and grains of /sup 3/H-glucosamine were localized in the trabecular region. The radioactivity of both isotopes was observed in the Golgi apparatuses of the endothelial cells of the angular aqueous plexus and the trabecular meshwork. The grains were noted over the entire cytoplasm, except for the nucleus, and then were incorporated into the amorphous substance and collagen fibers in the region adjacent to the angular aqueous sinus. These results suggest that endothelial cells in the angular region synthesize and secrete the sulfated glycosaminoglycans and hyaluronic acid.

  17. Distributions of 35S-sulfate and 3H-glucosamine in the angular region of the hamster: light and electron microscopic autoradiography

    International Nuclear Information System (INIS)

    Ohnishi, Y.; Taniguchi, Y.

    1983-01-01

    The distribution of 35 S-sulfate and 3 H-glucosamine in the angular region of the hamster was studied by light and electron microscopic autoradiography following intraperitoneal injection of these compounds to hamsters. Exposed silver grains of 35 S-sulfate were concentrated in the trabecular meshwork, sclera, and cornea, and grains of 3 H-glucosamine were localized in the trabecular region. The radioactivity of both isotopes was observed in the Golgi apparatuses of the endothelial cells of the angular aqueous plexus and the trabecular meshwork. The grains were noted over the entire cytoplasm, except for the nucleus, and then were incorporated into the amorphous substance and collagen fibers in the region adjacent to the angular aqueous sinus. These results suggest that endothelial cells in the angular region synthesize and secrete the sulfated glycosaminoglycans and hyaluronic acid

  18. Pathology of post-kala-azar dermal leishmaniasis: a light microscopical, immunohistochemical, and ultrastructural study of skin lesions and draining lymph nodes

    DEFF Research Database (Denmark)

    Ismail, Ahmed; Gadir, A Fattah A; Theander, Thor G

    2006-01-01

    cells. Degenerating basal keratinocytes expressed HLA-DR, ICAM-1 and Leishmania antigen and closely interacted with CD4 T cells. Regional lymph nodes showed hyperplasia of the B- and T-cell zones. Conclusions: The inflammatory reaction in PKDL lesions is in response to Leishmania parasites and....../or antigen. The majority of cells are CD4 T cells. Degeneration of the basal keratinocytes is probably due to the action of cytotoxic CD4 T cells interacting with leishmania-expressing epidermal cells. Ismail A, Gadir AFA, Theander TG, Kharazmi A, El Hassan AM. Pathology of post-kala-azar dermal...... leishmaniasis: a light microscopical, immunohistochemical, and ultrastructural study of skin lesions and draining lymph nodes....

  19. Bringing light into the nano-world: What can you do with an atomic force microscope on top of your synchrotron radiation sample holder?

    International Nuclear Information System (INIS)

    Rodrigues, Mario Manuel Silveira

    2009-01-01

    This thesis had as a major objective to combine scanning probe microscopy in particular, atomic force microscopy with synchrotron light spectroscopies. The combination of these two types of spectroscopies is meant to be in-situ and in real time. Thus this thesis aimed at introducing new types of experimental techniques suitable for the investigation of nano-sized materials. The proposed new instrumentation, would provide chemical-specific contrast at unprecedented lateral resolution of up to 10-40 nanometers, thus overcoming existing limitations of the two families of spectroscopy methods and opening a wide range of research opportunities and challenges. For the purpose of combining these techniques an atomic force microscope was developed. The atomic force microscope (AFM) was developed around a quartz tuning fork crystal which was used as the sensor with which atomic forces are detected. The developed AFM was then used in several beam lines with essentially two different purposes. A first goal was to do spectroscopy, such as the measurement of an absorption edge, locally with the tip of the AFM. Such measurements were indeed done, but the lateral resolution is still dominated by the X-ray beam size rather than by the tip apex shape. The AFM tip was also used to measure Bragg peaks from crystals with sizes on the nanometer scale. A second goal was to use the AFM as an instrument to mechanical interact with nano-sized systems while the X-ray beam was used to probe changes in the lattice parameter of the studied systems. Thus the AFM tip was used to elastically indent a SiGe crystal while diffraction was simultaneously measured. It was possible to observe shifts of the Bragg peak as a consequence of the applied pressure. The in-situ combination of AFM with synchrotron light permitted, in this way, to measure the Young modulus of a crystal at the nano-scale without any kind of adjustable parameter. (author)

  20. Defect-Resistant Radiative Performance of m-Plane Immiscible Al1-xInxN Epitaxial Nanostructures for Deep-Ultraviolet and Visible Polarized Light Emitters.

    Science.gov (United States)

    Chichibu, Shigefusa F; Kojima, Kazunobu; Uedono, Akira; Sato, Yoshitaka

    2017-02-01

    Planar vacuum-fluorescent-display devices emitting polarized UV-C, blue, and green light are demonstrated using immiscible Al 1- x In x N nanostructures grown in nonpolar m-directions. Despite the presence of high concentration of nonradiative recombination centers, the Al 1- x In x N nanostructures emit polarized light with the luminescence lifetimes of 22-32 ps at 300 K. This defect-resistant radiative performance suggests supernormal localized characteristics of electron-hole pairs. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. Mapping Circumstellar Matter with Polarized Light: The Case of Supernova 2014J in M82

    Science.gov (United States)

    Yang, Yi; Wang, Lifan; Baade, Dietrich; Brown, Peter. J.; Cikota, Aleksandar; Cracraft, Misty; Höflich, Peter A.; Maund, Justyn R.; Patat, Ferdinando; Sparks, William B.; Spyromilio, Jason; Stevance, Heloise F.; Wang, Xiaofeng; Wheeler, J. Craig

    2018-02-01

    Optical polarimetry is an effective way of probing the environment of a supernova for dust. We acquired linear HST ACS/WFC polarimetry in bands F475W, F606W, and F775W of the supernova (SN) 2014J in M82 at six epochs from ∼277 days to ∼1181 days after the B-band maximum. The polarization measured at day 277 shows conspicuous deviations from other epochs. These differences can be attributed to at least ∼{10}-6 {M}ȯ of circumstellar dust located at a distance of ∼ 5× {10}17 {cm} from the SN. The scattering dust grains revealed by these observations seem to be aligned with the dust in the interstellar medium that is responsible for the large reddening toward the supernova. The presence of this circumstellar dust sets strong constraints on the progenitor system that led to the explosion of SN 2014J; however, it cannot discriminate between single- and double-degenerate models.

  2. Variation in the circularly polarized light reflection of Lomaptera (Scarabaeidae) beetles.

    Science.gov (United States)

    Carter, I E; Weir, K; McCall, M W; Parker, A R

    2016-07-01

    An extended spectroscopic study on the left-through-left circularly polarized reflection spectra of a large number of beetles from the Australasian Scrabaeidae:Cetoniinae of the Lomaptera genus was undertaken. We have obtained a five-category spectral classification. The principal spectral features, which even within the genus range from blue to infrared, are related to structural chirality in the beetle shells. The detailed features of each spectral classification are related to different structural perturbations of the helix, including various pitch values and abrupt twist defects. These spectral characteristics and associated shell structures are confirmed on the basis of simple modelling. An important conclusion from our study is that the simple helical structure resulting in a single symmetric Bragg peak is not the dominant spectral type. Rather the reality is a rich tapestry of spectral types. One intriguing specimen is identified via a scanning electron micrograph to consist of a double interstitial helix leading to a particular double-peak spectrum. © 2016 The Authors.

  3. Circularly polarized near-field optical mapping of spin-resolved quantum Hall chiral edge states.

    Science.gov (United States)

    Mamyouda, Syuhei; Ito, Hironori; Shibata, Yusuke; Kashiwaya, Satoshi; Yamaguchi, Masumi; Akazaki, Tatsushi; Tamura, Hiroyuki; Ootuka, Youiti; Nomura, Shintaro

    2015-04-08

    We have successfully developed a circularly polarized near-field scanning optical microscope (NSOM) that enables us to irradiate circularly polarized light with spatial resolution below the diffraction limit. As a demonstration, we perform real-space mapping of the quantum Hall chiral edge states near the edge of a Hall-bar structure by injecting spin polarized electrons optically at low temperature. The obtained real-space mappings show that spin-polarized electrons are injected optically to the two-dimensional electron layer. Our general method to locally inject spins using a circularly polarized NSOM should be broadly applicable to characterize a variety of nanomaterials and nanostructures.

  4. Microscope basics.

    Science.gov (United States)

    Sluder, Greenfield; Nordberg, Joshua J

    2013-01-01

    This chapter provides information on how microscopes work and discusses some of the microscope issues to be considered in using a video camera on the microscope. There are two types of microscopes in use today for research in cell biology-the older finite tube-length (typically 160mm mechanical tube length) microscopes and the infinity optics microscopes that are now produced. The objective lens forms a magnified, real image of the specimen at a specific distance from the objective known as the intermediate image plane. All objectives are designed to be used with the specimen at a defined distance from the front lens element of the objective (the working distance) so that the image formed is located at a specific location in the microscope. Infinity optics microscopes differ from the finite tube-length microscopes in that the objectives are designed to project the image of the specimen to infinity and do not, on their own, form a real image of the specimen. Three types of objectives are in common use today-plan achromats, plan apochromats, and plan fluorite lenses. The concept of mounting video cameras on the microscope is also presented in the chapter. Copyright © 2003 Elsevier Inc. All rights reserved.

  5. Arctic Riverine CDOM and its effects on the Polar Marine Light Field

    Energy Technology Data Exchange (ETDEWEB)

    Orandle, Zoe Ann [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Weijer, Wilbert [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Elliott, Scott M. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Wang, Shanlin [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-09-28

    It is well-known that CDOM (Chromophoric Dissolved Organic Matter) can have a significant effect on biological activity in the photic zones of aquatic ecosystems. However, the extent of CDOM’s interference with biological activity is not well-known. We examined this issue in great detail in the mixed surface layer of the Arctic Ocean. We studied the impacts of CDOM’s light attenuation on Arctic phytoplankton populations to discover if riverine CDOM’s presence in the Arctic ocean could inhibit and possibly prevent local phytoplankton populations from performing photosynthesis. We incorporated biogeochemistry concepts and data with oceanographic models and calculations to approach the problem. The results showed that riverine CDOM can indeed significantly impact the productivity of phytoplankton populations during the spring and summer months near the major Arctic river mouths we chose to examine. Although our study was detailed and inclusive of many variables, the issue of CDOM’s light attenuation and its effects on phytoplankton populations must be explored on a global scale to help understand if riverine CDOM could prove disastrous for phytoplankton populations.

  6. Light Microscopy Module: On-Orbit Microscope Planned for the Fluids Integrated Rack on the International Space Station

    Science.gov (United States)

    Motil, Susan M.

    2002-01-01

    The Light Microscopy Module (LMM) is planned as a remotely controllable, automated, on-orbit facility, allowing flexible scheduling and control of physical science and biological science experiments within the Fluids Integrated Rack (FIR) on the International Space Station. Initially four fluid physics experiments in the FIR will use the LMM the Constrained Vapor Bubble, the Physics of Hard Spheres Experiment-2, Physics of Colloids in Space-2, and Low Volume Fraction Entropically Driven Colloidal Assembly. The first experiment will investigate heat conductance in microgravity as a function of liquid volume and heat flow rate to determine, in detail, the transport process characteristics in a curved liquid film. The other three experiments will investigate various complementary aspects of the nucleation, growth, structure, and properties of colloidal crystals in microgravity and the effects of micromanipulation upon their properties.

  7. Neural differentiation of transplanted neural stem cells in a rat model of striatal lacunar infarction: light and electron microscopic observations

    Science.gov (United States)

    Muñetón-Gómez, Vilma C.; Doncel-Pérez, Ernesto; Fernandez, Ana P.; Serrano, Julia; Pozo-Rodrigálvarez, Andrea; Vellosillo-Huerta, Lara; Taylor, Julian S.; Cardona-Gómez, Gloria P.; Nieto-Sampedro, Manuel; Martínez-Murillo, Ricardo

    2012-01-01

    The increased risk and prevalence of lacunar stroke and Parkinson's disease (PD) makes the search for better experimental models an important requirement for translational research. In this study we assess ischemic damage of the nigrostriatal pathway in a model of lacunar stroke evoked by damaging the perforating arteries in the territory of the substantia nigra (SN) of the rat after stereotaxic administration of endothelin-1 (ET-1), a potent vasoconstrictor peptide. We hypothesized that transplantation of neural stem cells (NSCs) with the capacity of differentiating into diverse cell types such as neurons and glia, but with limited proliferation potential, would constitute an alternative and/or adjuvant therapy for lacunar stroke. These cells showed neuritogenic activity in vitro and a high potential for neural differentiation. Light and electron microscopy immunocytochemistry was used to characterize GFP-positive neurons derived from the transplants. 48 h after ET-1 injection, we characterized an area of selective degeneration of dopaminergic neurons within the nigrostriatal pathway characterized with tissue necrosis and glial scar formation, with subsequent behavioral signs of Parkinsonism. Light microscopy showed that grafted cells within the striatal infarction zone differentiated with a high yield into mature glial cells (GFAP-positive) and neuron types present in the normal striatum. Electron microscopy revealed that NSCs-derived neurons integrated into the host circuitry establishing synaptic contacts, mostly of the asymmetric type. Astrocytes were closely associated with normal small-sized blood vessels in the area of infarct, suggesting a possible role in the regulation of the blood brain barrier and angiogenesis. Our results encourage the use of NSCs as a cell-replacement therapy for the treatment of human vascular Parkinsonism. PMID:22876219

  8. The effects of rearing light level and duration differences on the optic nerve, brain, and associated structures in developing zebrafish larvae: a light and transmission electron microscope study.

    Science.gov (United States)

    Chapman, George B; Tarboush, Rania; Connaughton, Victoria P

    2012-03-01

    The ultrastructure of the optic nerve, brain, and some associated structures of larval zebrafish, grown under three different light regimens were studied. Fish grown under cyclic light (control), constant dark (CD), and constant light (CL) were studied for 4 and 8 days postfertilization (dpf). We also studied the control and CD fish at 15 dpf. The brains of the control and CL fish were larger at 4 dpf than at 8 dpf. In all 4 dpf fish, the brain occupied the entire expanse between the two retinas and the optic nerve extended the shortest distance between the retina and the brain. The 15 dpf zebrafish had the smallest brain size. Groups of skeletal muscle cells associated with the optic nerves became visible in all older larvae. In the 15 dpf larvae, bulges and dilations in the optic nerve occurred as it reached the brain and optic chiasms occurred proximal to the brain. Electron microscopy yielded information about myelinated and unmyelinated axons in the optic nerve, the dimensions of neurotubules, neurofilaments, and myofilaments, including a unique variation in actin myofilaments, and a confirmation of reported myosin myofilament changes (but with dimensions). We also describe the ultrastructure of a sheath-like structure that is confluent over the optic nerve and the brain, which has not been described before in zebrafish. Also presented are images of associated fibroblasts, epithelial cells lining the mouth, cartilage plates, blood vessels, nerve bundles, and skeletal muscle cells, most of which have not been previously described in the literature. Copyright © 2012 Wiley Periodicals, Inc.

  9. Nanoscale coupling of photons to vibrational excitation of Ag nanoparticle 2D array studied by scanning tunneling microscope light emission spectroscopy.

    Science.gov (United States)

    Katano, Satoshi; Toma, Koji; Toma, Mana; Tamada, Kaoru; Uehara, Yoichi

    2010-11-28

    Scanning tunneling microscope light emission (STM-LE) spectroscopy has been utilized to elucidate the luminescence phenomena of Ag nanoparticles capped with myristate (myristate-capped AgNP) and 2-methyl-1-propanethiolate (C(4)S-capped AgNP) on the dodecanethiol-precovered Au substrate. The STM imaging revealed that myristate-capped AgNPs form an ordered hexagonal array whereas C(4)S-capped AgNPs show imperfect ordering, indicating that a shorter alkyl chain of C(4)S-capped AgNP is not sufficient to form rigid interdigitation. It should be noted that such a nanoparticle ordering affects the luminescence properties of the Ag nanoparticle. We found that the STM-LE is only detected from the Ag nanoparticles forming the two-dimensional superlattice. This indicates that the STM-LE of the Ag nanoparticle is radiated via the collective excitation of the local surface plasmon resonance (LSPR) spread over the Ag nanoparticles. Note that the STM-LE spectra of the Ag nanoparticles exhibit spike-like peaks superimposed on the broad light emission peak. Using Raman spectroscopy, we concluded that the spike-like structure appearing in the STM-LE spectra is associated with the vibrational excitation of the molecule embedded between Ag nanoparticles.

  10. The influence of iron and light on net community production in the Subantarctic and Polar Frontal Zones

    Directory of Open Access Journals (Sweden)

    N. Cassar

    2011-02-01

    Full Text Available The roles of iron and light in controlling biomass and primary productivity are clearly established in the Southern Ocean. However, their influence on net community production (NCP and carbon export remains to be quantified. To improve our understanding of NCP and carbon export production in the Subantarctic Zone (SAZ and the northern reaches of the Polar Frontal Zone (PFZ, we conducted continuous onboard determinations of NCP as part of the Sub-Antarctic Sensitivity to Environmental Change (SAZ-Sense study, which occurred in January–February 2007. Biological O2 supersaturation was derived from measuring O2/Ar ratios by equilibrator inlet mass spectrometry. Based on these continuous measurements, NCP during the austral summer 2007 in the Australian SAZ was approximately 43 mmol O2 m−2 d−1. NCP showed significant spatial variability, with larger values near the Subtropical front, and a general southward decrease. For shallower mixed layers (<50 m, dissolved Fe concentrations and Fe sufficiency, estimated from variable fluorescence, correlated strongly with NCP. The strong correlation between NCP and dissolved Fe may be difficult to interpret because of the correlation of dissolved Fe to MLD and because the concentration of iron may not be a good indicator of its availability. At stations with deeper mixed layers, NCP was consistently low, regardless of iron sufficiency, consistent with light availability also being an important control of NCP. Our new observations provide independent evidence for the critical roles of iron and light in mediating carbon export from the Southern Ocean mixed layer.

  11. MECHANISMS OF PRIMARY RECEPTION OF ELECTROMAGNETIC WAVES OF OPTICAL RANGE AS A BIOPHYSICAL BASIS OF POLARIZED LIGHT THERAPY

    Directory of Open Access Journals (Sweden)

    S. O. Hulyar

    2015-09-01

    Full Text Available An existence of separate functional system of electromagnetic balance regulation has been substantiated and a working conception of light puncture has been formulated. As a basis, there is a possibility to use the acupuncture points for input of biologically necessary electromagnetic waves into the system of their conductors in a body that might be considered as a transport facility for energy ofthe polarized electromagnetic waves. Zones-recipients are organs having an electromagnetic disbalance due to excess of biologically inadequate radiation and being the targets for peroxide oxidation, foremost, a body has the neurohormonal and immune regulatory systems. Electromagnetic stimulation or modification of functions of the zones-recipients determines achievement of therapeutic and useful effects, and their combination with local reparative processes allows attaining a clinical goal. We represent own and literary experimental data about development of physiological responses (analgesia, bronchospasm control, immune stimulation and inhibition of peroxide oxidation of lipids to BIOPTRON-light exposure on the acupuncture points or biologically active zones. We show the experimental facts in support of a hypothesis that a living organism can perceive an action of the electromagnetic waves of optical range not only via the visual system, but also through the off-nerve receptors (specific energy-sensitive proteins detecting critical changes of energy in cells and functioning as the "sensory" cell systems, as well as via the acupuncture points. This confirms an important role of the electromagnetic waves of optical range in providing normal vital functions of living organisms. A current approach to BIOPTRON light therapy consists in combined (local and system exposure of the electromagnetic waves within the biologically necessary range.

  12. Microwave Microscope

    Data.gov (United States)

    Federal Laboratory Consortium — FUNCTION: Makes ultra-high-resolution field measurements. The Microwave Microscope (MWM) has been used in support of several NRL experimental programs involving sea...

  13. Microscopic study on proton elastic scattering of light exotic nuclei at energies below than 100 MeV/nucleon

    Energy Technology Data Exchange (ETDEWEB)

    Farag, M.Y.H.; Esmael, E.H. [Cairo University, Physics Department, Faculty of Science, Giza (Egypt); Maridi, H.M. [Cairo University, Physics Department, Faculty of Science, Giza (Egypt); Taiz University, Physics Department, Faculty of Applied Science, Taiz (Yemen)

    2012-11-15

    The proton elastic scattering data on some light exotic nuclei, namely, {sup 6,} {sup 8}He, {sup 9,} {sup 11}Li, and {sup 10,} {sup 11,} {sup 12}Be, at energies below than 100MeV/nucleon are analyzed using the single folding optical model. The real, imaginary, and spin-orbit parts of the optical potential (OP) are constructed only from the folded potentials and their derivatives using M3Y effective nucleon-nucleon interaction. These OP parts, their renormalization factors and their volume integrals are studied. The surface and spin-orbit potentials are important to fit the experimental data. Three model densities for halo nuclei are used and the sensitivity of the cross-sections to these densities is tested. The imaginary OP within high-energy approximation is used and compared with the single folding OP. This OP with few and limited fitting parameters, which have systematic behavior with incident energy, successfully describes the proton elastic scattering data with exotic nuclei. (orig.)

  14. A Light and Electron Microscope Study of the Epithelial Cells of the Gut of Fasciola hepatica L

    Science.gov (United States)

    Gresson, R. A. R.; Threadgold, L. T.

    1959-01-01

    The structure of the epithelial cells of the alimentary tract of Fasciola hepatica was investigated by means of light and electron microscopy. Tissue prepared for electron microscopy was fixed in 1 per cent osmium tetroxide, buffered with veronal to a pH of 7.4, and embedded in butyl methacrylate with 1 per cent benzoyl peroxide as a catalyst. Polymerisation was carried out at 60°C. The majority, if not all, the epithelial cells pass through both absorptive and secretory cycles. The free ends of absorptive cells possess fine protoplasmic processes that project into the lumen of the gut. These are apparently concerned with the absorption of nutriment. In electron micrographs, the protoplasmic (absorptive) processes are frequently seen to be in the form of tubular loops both ends of which arise from the same cell. The free end of a process is often expanded into a ribbon-like structure. Each process possesses an external limiting membrane and an internal membranous ultrastructure. When a cell becomes glandular in function, the protoplasmic processes seem to become less numerous. The plasma membrane is invaginated into the basal part of an absorptive cell. In the neighbourhood of the lumen of the gut where two tall cells are in contact, bands of amorphous cytoplasmic material are in contact with each cell membrane. PMID:13829217

  15. In vivo and in vitro effects of imidacloprid on sheep keds (Melophagus ovinus): a light and electron microscopic study.

    Science.gov (United States)

    Mehlhorn, H; D'Haese, J; Mencke, N; Hansen, O

    2001-04-01

    The effects of imidacloprid (Advantage) on sheep keds (Melophagus ovinus Linne 1758) were studied in vivo and in vitro by means of direct observation (monitored on video tape) and by light and electron microscopy. It was found that: 1. Imidacloprid acted rapidly on all motile stages of the sheep keds. Within 3-4 min after exposure they became immobile and their legs and the abdomen started tetanic trembling movements for 15-30 min, leading to death. 2. The compound is apparently taken up by the body, since it also acted on those sheep keds that had been exclusively exposed to imidacloprid-contaminated filter papers. 3. The compound is available and active for more than 1 month in the wool of sheep; even rainfall does not reduce its efficacy. Body contact between treated mother sheep and their lambs protects them from infestation with these ectoparasites. 4. The compound initiates an ultimately lethal destruction of the ganglia, nerve chords and related muscle fibers, as can be seen in electron micrographs.

  16. Calculated Hanle transmission and absorption spectra of the 87Rb D1 line with residual magnetic field for arbitrarily polarized light

    International Nuclear Information System (INIS)

    Noh, Heung-Ryoul; Moon, Han Seb

    2010-01-01

    This paper reports a theoretical study on the transmission spectra of an arbitrarily polarized laser beam through a rubidium cell with or without a buffer gas in Hanle-type coherent population trapping (CPT). This study examined how laser polarization, transverse magnetic field, and collisions with buffer gas affects the spectrum. The transmission spectrum due to CPT and the absorption spectrum due to the level crossing absorption (LCA) were calculated according to the laser polarization. The results show that the LCA is strongly dependent on the transverse magnetic field and interaction time of the atoms with a laser light via collisions with the buffer gas. In addition, the spectral shape of the calculated Hanle spectrum is closely related to the direction between the (stray) transverse magnetic field and polarization of the laser.

  17. Lungs of the gecko Rhacodactylus leachianus (Reptilia: Gekkonidae): a correlative gross anatomical and light and electron microscopic study.

    Science.gov (United States)

    Perry, S F; Bauer, A M; Russell, A P; Alston, J T; Maloney, J E

    1989-01-01

    The lungs of the New Caldeonian gecko Rhacodactylus leachianus were examined by means of gross dissection and light and electron microscopy. This tropical species, which is the largest living gecko, possesses two simple, single-chambered lungs. Right and left lungs are of similar size and shape. The lung volume (27.2 ml.100 g-1) is similar to that of the tokay (Gekko gecko) but differs in that the gas exchange tissue is approximately homogeneously distributed, and the parenchymal units (ediculae) are very large, approximately 2 mm in diameter. The parenchymal depth varies according to the location in the lung, being deepest near the middle of the lung and shallowest caudally. Scanning and transmission electron microscopy reveal an unusual distribution of ciliated cells in patches on the edicular walls as well as on the trabeculae. Secretory cells are very numerous, particularly in the bronchial epithelium, where they greatly outnumber the ciliated cells. The secretory cells form a morphological continuum characterized by small secretory droplets apically and large vacuoles basally. This continuum includes cells resembling type II pneumocytes but which are devoid of lamellar bodies. Type I pneumocytes similar to those of other reptiles cover the respiratory capillaries, where they form a thin, air-blood barrier together with the capillary endothelial cells and the fused basement laminae. The innervation, musculature, and vascular distribution in R. leachianus are also characterized. Apparent simplification of the lungs in this taxon may be related to features of its sluggish habits, whereas peculiarities of cell and tissue composition may reflect demands of its mesic habitat.

  18. Role of l-carnitine in the prevention of seminiferous tubules damage induced by gamma radiation: a light and electron microscopic study

    International Nuclear Information System (INIS)

    Topcu-Tarladacalisir, Yeter; Kanter, Mehmet; Uzal, Mustafa Cem

    2009-01-01

    The present study, we hypothesized that l-carnitine can minimize germ-cell depletion and morphological features of late cell damage in the rat testis following gamma (γ)-irradiation. Wistar albino male rats were divided into three groups. Control group received physiological saline 0.2 ml intraperitoneally (i.p.), as placebo. Radiation group received scrotal γ-irradiation of 10 Gy as a single dose plus physiological saline. Radiation + l-carnitine group received scrotal γ-irradiation plus 200 mg/kg i.p. l-carnitine. l-carnitine starting 1 day before irradiation and 21 days (three times per week) after irradiation. Testis samples of the all groups were taken at day 21, 44 and 70 post-irradiation. All samples were processed at the light and electron microscopic levels. Morphologically, examination of γ-irradiated testis revealed presence of marked disorganization and depletion of germ cells, arrest of spermatogenesis, formation of multinucleated giant cells, and vacuolization in the germinal epithelium. The type and extent of these changes varied at different post-treatment intervals. The damage was evident at the 21st day and reached maximum level by the 44th day. By day 44 post-irradiation, the changes were most advanced, and were associated with atrophied seminiferous tubules without germ cells, the increase in the number and size of vacuolizations in germinal epithelium, and the absent multinucleated giant cells due to spermatids had completely disappeared. The increase in nucleus invaginations, the dilatation of smooth endoplasmic reticulum cysternas and the increase in the number and size of lipid droplets in the Sertoli cells were determined at the electron microscopic level. In conclusion, l-carnitine supplementation during the radiotherapy would be effective in protecting against radiation-induced damages in rat testis, and thereby may improve the quality of patient's life after the therapy. (orig.)

  19. Role of l-carnitine in the prevention of seminiferous tubules damage induced by gamma radiation: a light and electron microscopic study

    Energy Technology Data Exchange (ETDEWEB)

    Topcu-Tarladacalisir, Yeter; Kanter, Mehmet [Trakya University, Department of Histology and Embryology, Faculty of Medicine, Edirne (Turkey); Uzal, Mustafa Cem [Trakya University, Department of Radiation Oncology, Faculty of Medicine, Edirne (Turkey)

    2009-08-15

    The present study, we hypothesized that l-carnitine can minimize germ-cell depletion and morphological features of late cell damage in the rat testis following gamma ({gamma})-irradiation. Wistar albino male rats were divided into three groups. Control group received physiological saline 0.2 ml intraperitoneally (i.p.), as placebo. Radiation group received scrotal {gamma}-irradiation of 10 Gy as a single dose plus physiological saline. Radiation + l-carnitine group received scrotal {gamma}-irradiation plus 200 mg/kg i.p. l-carnitine. l-carnitine starting 1 day before irradiation and 21 days (three times per week) after irradiation. Testis samples of the all groups were taken at day 21, 44 and 70 post-irradiation. All samples were processed at the light and electron microscopic levels. Morphologically, examination of {gamma}-irradiated testis revealed presence of marked disorganization and depletion of germ cells, arrest of spermatogenesis, formation of multinucleated giant cells, and vacuolization in the germinal epithelium. The type and extent of these changes varied at different post-treatment intervals. The damage was evident at the 21st day and reached maximum level by the 44th day. By day 44 post-irradiation, the changes were most advanced, and were associated with atrophied seminiferous tubules without germ cells, the increase in the number and size of vacuolizations in germinal epithelium, and the absent multinucleated giant cells due to spermatids had completely disappeared. The increase in nucleus invaginations, the dilatation of smooth endoplasmic reticulum cysternas and the increase in the number and size of lipid droplets in the Sertoli cells were determined at the electron microscopic level. In conclusion, l-carnitine supplementation during the radiotherapy would be effective in protecting against radiation-induced damages in rat testis, and thereby may improve the quality of patient's life after the therapy. (orig.)

  20. Imaging arrangement and microscope

    Science.gov (United States)

    Pertsinidis, Alexandros; Chu, Steven

    2015-12-15

    An embodiment of the present invention is an imaging arrangement that includes imaging optics, a fiducial light source, and a control system. In operation, the imaging optics separate light into first and second tight by wavelength and project the first and second light onto first and second areas within first and second detector regions, respectively. The imaging optics separate fiducial light from the fiducial light source into first and second fiducial light and project the first and second fiducial light onto third and fourth areas within the first and second detector regions, respectively. The control system adjusts alignment of the imaging optics so that the first and second fiducial light projected onto the first and second detector regions maintain relatively constant positions within the first and second detector regions, respectively. Another embodiment of the present invention is a microscope that includes the imaging arrangement.