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Sample records for nonresonant confocal raman

  1. Confocal Raman Microscopy

    CERN Document Server

    Dieing, Thomas; Toporski, Jan

    2011-01-01

    Confocal Raman Microscopy is a relatively new technique that allows chemical imaging without specific sample preparation. By integrating a sensitive Raman spectrometer within a state-of-the-art microscope, Raman microscopy with a spatial resolution down to 200nm laterally and 500nm vertically can be achieved using visible light excitation. Recent developments in detector and computer technology as well as optimized instrument design have reduced integration times of Raman spectra by orders of magnitude, so that complete images consisting of tens of thousands of Raman spectra can be acquired in seconds or minutes rather than hours, which used to be standard just one decade ago. The purpose of this book is to provide the reader a comprehensive overview of the rapidly developing field of Confocal Raman Microscopy and its applications.

  2. Confocal Raman Microscopy; applications in tissue engineering

    NARCIS (Netherlands)

    van Apeldoorn, Aart A.

    2005-01-01

    This dissertation describes the use of confocal Raman microscopy and spectroscopy in the field of tissue engineering. Moreover, it describes the combination of two already existing technologies, namely scanning electron microscopy and confocal Raman spectroscopy in one apparatus for the enhancement

  3. Confocal Raman Imaging of Polymeric Materials

    Science.gov (United States)

    Schmidt, Ute; Müller, Jörg; Koenen, Joachim

    Polymers play an essential role in modern materials science. Due to the wide variety of mechanical and chemical properties of polymers, they are used in almost every field of application and are still a dynamic area in the development of new materials with demanding requirements. Raman spectroscopy is one of the standard characterization techniques used to uniquely determine the chemical composition of a polymer. Modern materials, however, are generally heterogeneous, in which various chemical components or polymorphs of the same chemical species can be present in a very small sample volume. For the analysis of such heterogeneous materials, the combination of Raman spectroscopy with confocal microscopy delivers information about the spatial distribution of the various chemical species with a resolution down to 200 nm. The aim of this contribution is to demonstrate the power of confocal Raman imaging for the characterization of heterogeneous polymeric materials. The first section will deal with polymorphs of polypropylene in polymer films, followed by the nondestructive analysis of polymer blends. A later section will deal with multi-layer polymer coatings and paints and finally various additives to polymer matrices will be discussed.

  4. Confocal Raman microspectroscopy of the skin.

    Science.gov (United States)

    Förster, Matthias; Bolzinger, Marie-Alexandrine; Montagnac, Gilles; Briançon, Stéphanie

    2011-01-01

    Confocal Raman spectroscopy is a technique with considerable potential for the non-invasive study of biological tissues and skin samples in vitro or in vivo. It can be used to study skin physiology and possible pathological conditions and to obtain data about molecular composition and the structure of skin, for example, water content, moisturization and changes in the skin barrier function can all be observed. In-depth measurements also allow biopharmaceutical studies, such as analyzing the rate of penetration of a drug and the biochemical changes that may be induced by an applied formulation. Confocal Raman microspectroscopy is now at such a stage of refinement that it opens up new vistas. The big leap forward in its ease of use enables this technology to be used as an analytical method by more and more non-specialist laboratories. This review gives an overview of the state of the art of this technology by presenting an update on the principles of Raman spectroscopy and then by looking at examples of new developments in in vivo and in vitro applications.

  5. Confocal Raman spectroscopy of whole hairs.

    Science.gov (United States)

    Pudney, Paul D A; Bonnist, Eleanor Y M; Mutch, Kevin J; Nicholls, Rachel; Rieley, Hugh; Stanfield, Samuel

    2013-12-01

    This paper describes the application of Raman spectroscopy to whole hair fibers. Previously this has proved difficult because the hairs are relatively opaque, and spatial resolution diminishes with depth because of the change in refractive index. A solution is to couple confocal Raman with multivariate curve resolution (MCR) data analysis, which separates spectral differences with depth despite this reduction in resolution. Initially, it is shown that the cuticle can be separated from the cortex, showing the differences in the proteins, which can then be plotted as a function of depth, with the cuticle factor being seen only at the surface as expected. Hairs that had been treated in different ways, e.g., by bleaching, treatment with the active molecule resorcinol followed by rinsing and treatment with a full hair care product, were also examined. In all cases, changes to the hair are identified and are associated with specific parts of the fiber. Since the hair fiber is kept intact, it can be repeatedly treated and measured, hence multistep treatment processes can be followed. This method expands the potential use of Raman spectroscopy in hair research.

  6. Electron Raman scattering in a double quantum well tuned by an external nonresonant intense laser field

    Science.gov (United States)

    Tiutiunnyk, A.; Mora-Ramos, M. E.; Morales, A. L.; Duque, C. M.; Restrepo, R. L.; Ungan, F.; Martínez-Orozco, J. C.; Kasapoglu, E.; Duque, C. A.

    2017-02-01

    In this work we shall present a study of inelastic light scattering involving inter-subband electron transitions in coupled GaAs-(Ga,Al)As quantum wells. Calculations include the electron related Raman differential cross section and Raman gain. The effects of an external nonresonant intense laser field are used in order to tune these output properties. The confined electron states will be described by means of a diagonalization procedure within the effective mass and parabolic band approximations. It is shown that the application of the intense laser field can produce values of the intersubband electron Raman gain above 400 cm-1. The system proposed here is an alternative choice for the development of AlxGa1-xAs semiconductor laser diodes that can be tuned via an external nonresonant intense laser field.

  7. Confocal Raman Microspectroscopy of Oral Streptococci

    Science.gov (United States)

    Beier, Brooke D.

    Raman spectroscopy has been used in a variety of applications throughout the field of biomedical optics. It has the ability to acquire chemically-specific information in a non-invasive manner, without the need for exogenous markers. This makes it useful in the identification of bacterial species, as well as in the study of tissues and other cells. In this work, a species identification model has been created in order to discriminate between the oral bacterial species Streptococcus sanguinis and Streptococcus mutans. These are two of the most prevalent species within the human mouth and their relative concentrations can be an indicator of a patient's oral health and risk of tooth decay. They are predominantly found within plaque on the tooth's surface. To study a simplified model for dental plaque, we have examined S. sanguinis and S. mutans grown in biofilm forms. Raman spectroscopy has been implemented here through a confocal microscope. The optical system has been equipped with computationally controlled stages to allow for automated scanning, including autofocusing to probe a consistent depth within a sample. A spectrum has been acquired from each position within a scan and sent for spectral preprocessing before being submitted for species identification. This preprocessing includes an algorithm that has been developed to remove fluorescence features from known contaminants within the confocal volume, to include signal from a fluorescent substrate. Species classification has been accomplished using a principal component score-fed logistic regression model constructed from a variety of biofilm samples that have been transferred and allowed to dry, as might occur with the study of plaque samples. This binary classification model has been validated on other samples with identical preparations. The model has also been transferred to determine the species of hydrated biofilms studied in situ. Artificially mixed biofilms have been examined to test the spatial

  8. Single-Molecule Surface-Enhanced Raman Scattering Spectrum of Non-Resonant Aromatic Amine Showing Raman Forbidden Bands

    CERN Document Server

    Yamamoto, Yuko S; Ozaki, Yukihiro; Zhang, Zhenglong; Kozu, Tomomi; Itoh, Tamitake; Nakanishi, Shunsuke

    2016-01-01

    We present the experimentally obtained single-molecule (SM) surface-enhanced Raman scattering (SERS) spectrum of 4-aminibenzenethiol (4-ABT), also known as para-aminothiophenol (PATP). Measured at a 4-ABT concentration of 8 * 10^-10 M, the spectra show Raman forbidden modes. The SM-SERS spectrum of 4-ABT obtained using a non-resonant visible laser is different from the previously reported SERS spectra of 4-ABT, and could not be reconstructed using quantum mechanical calculations. Careful classical assignments (not based on quantum-mechanical calculations) are reported, and indicate that differences in the reported spectra of 4-ABT are mainly due to the appearance of Raman forbidden bands. The presence of Raman forbidden bands can be explained by the charge-transfer (CT) effect of 4-ABT adsorbed on the silver nanostructures, indicating a breakdown of Raman selection rules at the SERS hotspot.

  9. The evaluation of temporal electronic structures of nonresonant Raman excited virtual state of thiourea

    Institute of Scientific and Technical Information of China (English)

    Fang Chao; Sun Li-Feng

    2011-01-01

    An algorithm has been introduced to calculate molecular bond polarizabilities of thiourea, which supply essential electronic information about the nonresonant Raman excited virtual states.The main dynamical behaviour of the excited virtual states of thiourea is that the Raman excited electrons tend to flow to the N-H bonds and C-N bonds from the S-C bonds because of the electronic repulsion effect. The difference in Raman excited electron relaxation time of thiourea under 514.5-nm and 325-nm excitations has been observed, which quantitatively shows that the Raman scattering process is dependent on the wavelength of the pumping laser. Finally, the distribution of the electrons at the final stage of relaxation is given out through the comparison between the bond electronic densities of the ground states and the bond polarizabilities after deexcitation.

  10. Communication: Significant contributions of Albrecht's $A$ term to non-resonant Raman scattering processes

    CERN Document Server

    Duan, Sai; Luo, Yi

    2015-01-01

    The Raman intensity can be well described by the famous Albrecht equation that consists of $A$ and $B$ terms. It has become a textbook knowledge that the contribution from Albrecht's $A$ term can be neglected without loss of accuracy for non-resonant Raman scattering processes. However, as demonstrated in this study, we have found that this widely accepted long-standing assumption fails drastically for totally symmetric vibration modes of molecules. Perturbed first principles calculations for water molecule show that strong constructive interference between the $A$ and $B$ terms occurs for the Raman intensity of the symmetric O-H stretching mode, which can account for about 40% of the total intensity. Meanwhile, a minor destructive interference is found for the angle bending mode. The state to state mapping between the Albrecht's theory and the perturbation theory allows us to verify the accuracy of the widely employed perturbation method for the dynamic/resonant Raman intensities. The model calculations show...

  11. Combined in vivo confocal Raman spectroscopy and confocal microscopy of human skin

    NARCIS (Netherlands)

    P.J. Caspers (Peter); G.W. Lucassen (Gerald); G.J. Puppels (Gerwin)

    2003-01-01

    textabstractIn vivo confocal Raman spectroscopy is a noninvasive optical method to obtain detailed information about the molecular composition of the skin with high spatial resolution. In vivo confocal scanning laser microscopy is an imaging modality that provides optical sections

  12. Confocal Raman microscopy for identification of bacterial species in biofilms

    Science.gov (United States)

    Beier, Brooke D.; Quivey, Robert G.; Berger, Andrew J.

    2011-03-01

    Implemented through a confocal microscope, Raman spectroscopy has been used to distinguish between biofilm samples of two common oral bacteria species, Streptococcus sanguinis and mutans, which are associated with healthy and cariogenic plaque, respectively. Biofilms of these species are studied as a model of dental plaque. A prediction model has been calibrated and validated using pure biofilms. This model has been used to identify the species of transferred and dehydrated samples (much like a plaque scraping) as well as hydrated biofilms in situ. Preliminary results of confocal Raman mapping of species in an intact two-species biofilm will be shown.

  13. Confocal raman microspectroscopy : a novel diagnostic tool in medical microbiology

    NARCIS (Netherlands)

    K. Maquelin (Kees)

    2002-01-01

    textabstractThe aim of the research described in this thesis was to develop confocal Raman microspectroscopy techniques for the rapid identification and characterisation of clinically relevant microorganisms. Chapter 2 describes a study in which the accuracy of the identification of Enterococcus spp

  14. Characterization of Developing Cotton Fibers by Confocal Raman Microscopy

    Directory of Open Access Journals (Sweden)

    Luis Cabrales

    2014-10-01

    Full Text Available Cellulose deposition in developing cotton fibers has been studied previously with analytical techniques, such as Fourier transform infrared spectroscopy (FTIR, High-performance liquid chromatography (HPLC and Thermogravimetric analysis (TGA. Recent technological developments in instrumentation have made Raman microscopy emerge as an extraordinary analytical tool in biological and plant research. The advantage of using confocal Raman microscopy (CRM resides in the lateral spatial resolution and in the fact that Raman spectroscopy provides not only chemical composition information, but also structural information. Cross-sections of cotton fibers harvested at different developmental stages were studied with CRM. The Raman bands assigned to cellulose were analyzed. The results of this study indicate that CRM can be used as a tool to study cellulose deposition in cotton fibers and could provide useful information on cellulose deposition during cotton fiber development.

  15. Tilted Two-Dimensional Array Multifocus Confocal Raman Microspectroscopy.

    Science.gov (United States)

    Yabumoto, Sohshi; Hamaguchi, Hiro-O

    2017-07-18

    A simple and efficient two-dimensional multifocus confocal Raman microspectroscopy featuring the tilted-array technique is demonstrated. Raman scattering from a 4 × 4 square foci array passing through a 4 × 4 confocal pinhole array is tilted with a periscope. The tilted array of Raman scattering signals is dispersed by an imaging spectrograph onto a CCD detector, giving 16 independent Raman spectra formed as 16 bands with different heights on the sensor. Use of a state-of-the-art imaging spectrograph enables high-precision wavenumber duplicability of the 16 spectra. This high duplicability makes the simultaneously obtained spectra endurable for multivariate spectral analyses, which is demonstrated by a singular value decomposition analysis for Raman spectra of liquid indene. Although the present implementation attains only 16 measurement points, the number of points can be extended to larger than 100 without any technical leaps. Limit of parallelization depends on the interval of measurement points as well as the performance of the optical system. Criteria for finding the maximum feasible number are discussed.

  16. Confocal volume in laser Raman microscopy depth profiling

    Energy Technology Data Exchange (ETDEWEB)

    Maruyama, Yutaka; Kanematsu, Wataru [National Institute of Advanced Industrial Science and Technology, 2266-98 Anagahora, Shimo-Shidami, Moryama-ku, Nagoya 463-8560 (Japan)

    2011-11-15

    To clarify the degradation of confocality in laser Raman microscopy depth profiling (optical sectioning) and the influence of pinhole filtering on it, we investigate the confocal volume in detail based on Gaussian beam optics and scalar wave optics. Theoretical depth profiles of a homogeneous transparent sample for four different pinhole sizes, which are computed using the measured incident beam waist radius w{sub 0} and only a few optical system specific parameters such as a numerical aperture (NA) and a focal length, show a good agreement with the corresponding measured depth profiles. The computed confocal volume demonstrates that the pinhole size affects the actual probe depth as well as the axial resolution and the total intensity loss.

  17. Confocal Raman-AFM, A New Tool for Materials Research

    Science.gov (United States)

    Schmidt, Ute

    2005-03-01

    Characterization of heterogeneous systems, e.g. polymers, on the nanometer scale continues to grow in importance and to impact key applications in the field of materials science, nanotechnology and catalysis. The development of advanced polymeric materials for such applications requires detailed information about the physical and chemical properties of these materials on the nanometer scale. However, some details about the phase-separation process in polymers are difficult to study with conventional characterization techniques due to the inability of these methods to chemically differentiate materials with good spatial resolution, without damage, staining or preferential solvent washing. The CR-AFM is a breakthrough in microscopy. It combines three measuring techniques in one instrument: a high resolution confocal optical microscope, an extremely sensitive Raman spectroscopy system, and an Atomic Force Microscope. Using this instrument, the high spatial and topographical resolution obtained with an AFM can be directly linked to the chemical information gained by Confocal Raman spectroscopy. To demonstrate the capabilities of this unique combination of measuring techniques, polymer blend films, spin coated on glass substrates, have been characterized. AFM measurements reveal the structural and mechanical properties of the films, whereas Raman spectral images show the chemical composition of the blends.

  18. Improving spatial resolution of confocal Raman microscopy by super-resolution image restoration.

    Science.gov (United States)

    Cui, Han; Zhao, Weiqian; Wang, Yun; Fan, Ying; Qiu, Lirong; Zhu, Ke

    2016-05-16

    A new super-resolution image restoration confocal Raman microscopy method (SRIR-RAMAN) is proposed for improving the spatial resolution of confocal Raman microscopy. This method can recover the lost high spatial frequency of the confocal Raman microscopy by using Poisson-MAP super-resolution imaging restoration, thereby improving the spatial resolution of confocal Raman microscopy and realizing its super-resolution imaging. Simulation analyses and experimental results indicate that the spatial resolution of SRIR-RAMAN can be improved by 65% to achieve 200 nm with the same confocal Raman microscopy system. This method can provide a new tool for high spatial resolution micro-probe structure detection in physical chemistry, materials science, biomedical science and other areas.

  19. Confocal Raman Microspectroscopy for Evaluating the Stratum Corneum Removal by 3 Standard Methods

    National Research Council Canada - National Science Library

    Förster, M; Bolzinger, M.A; Rovere, M.R; Damour, O; Montagnac, G; Briançon, S

    2011-01-01

    ...: The removal qualities of tape stripping, cyanoacrylate skin surface biopsy and trypsinization were estimated in vitro via histological imaging and confocal Raman microspectroscopy (CRM) and compared...

  20. Single-molecule surface-enhanced Raman scattering of R6G in aqueous environment under non-resonance conditions

    Institute of Scientific and Technical Information of China (English)

    Enzhong Tan; Penggang Yin; Lidong Li; Lin Guo

    2011-01-01

    The single-molecule surface-enhanced Raman scattering (SERS) spectra of Rhodamine 6G (R6G) in an aqueous environment under non-resonance conditions are studied. Series of spectra are recorded in time-mapping mode, and intensity fluctuations of SERS signals and spectral diffusion are observed. The correlations between the presence frequency of SERS spectra and number of hot spots as well as the quantity of molecules in scattering volume are examined thoroughly. The results indicate that only molecules located at hot spots produce good signal-to-noise ratio Raman spectra and the origin of fluctuating SERS signals are mainly ascribed to the movement of hot spots.%@@ The single-molecule surface-enhanced Raman scattering(SERS) spectra of Rhodamine 6G(R6G) in anaqueous environment under non-resonance conditions are studied.Series of spectra are recorded in timemapping mode,and intensity fluctuations of SERS signals and spectral diffusion are observed.The correlations between the presence frequency of SERS spectra and number of hot spots as well as the quantity of molecules in scattering volume are examined thoroughly.

  1. Hybrid Rayleigh, Raman and TPE fluorescence spectral confocal microscopy of living cells

    NARCIS (Netherlands)

    Pully, V.V.; Lenferink, Aufrid T.M.; Otto, Cornelis

    2010-01-01

    A hybrid fluorescence–Raman confocal microscopy platform is presented, which integrates low-wavenumber-resolution Raman imaging, Rayleigh scatter imaging and two-photon fluorescence (TPE) spectral imaging, fast ‘amplitude-only’ TPE-fluorescence imaging and high-spectral-resolution Raman imaging.

  2. Raman spectra of zinc phthalocyanine monolayers absorbed on glassy carbon and gold electrodes by application of a confocal Raman microspectrometer

    NARCIS (Netherlands)

    Palys-Staron, B.J.; Palys, B.J.; Puppels, G.J.; Puppels, G.J.; van den Ham, D.M.W.; van den Ham, D.M.W.; Feil, D.; Feil, D.

    1992-01-01

    Raman spectra of zinc phthalocyanine monolayers, adsorbed on gold and on glassy carbon surfaces (electrodes), are presented. These spectra have been recorded with the electrodes inside and outside an electrochemical cell filled with an aqueous electrolyte. A confocal Raman microspectrometer was

  3. Theoretical investigation on Raman induced Kerr effect spectroscopy in nonlinear confocal microscopy

    Institute of Scientific and Technical Information of China (English)

    Gun LiNa; TANG ZhiLie; XING Da

    2008-01-01

    The imaging theory of Raman induced Kerr effect spectroscopy (RIKES) in nonlinear confocal microscopy is presented in this paper. Three-dimensional point spread function (3D-PSF) of RIKES nonlinear confocal microscopy in isotropic media is derived with Fourier imaging theory and RIKES theory. The impact of nonlinear property of RIKES on the spatial resolution and imaging properties of confocal microscopy have been analyzed in detail. It is proved that RIKES nonlinear confocal microscopy can simultaneously provide more information than twophoton confocal microscopy concerning molecular vibration mode, vibration orientation and optically induced molecular reorientation, etc. It is shown that RIKES nonlinear confocal microscopy significantly enhances the spatial resolution and imaging quality of confocal microscopy and achieves much higher resolution than that of two-photon confocal microscopy.

  4. Theoretical investigation on Raman induced Kerr effect spectroscopy in nonlinear confocal microscopy

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    The imaging theory of Raman induced Kerr effect spectroscopy (RIKES) in nonlinear confocal microscopy is presented in this paper. Three-dimensional point spread function (3D-PSF) of RIKES nonlinear confocal microscopy in isotropic media is derived with Fourier imaging theory and RIKES theory. The impact of nonlinear property of RIKES on the spatial resolution and imaging properties of confocal microscopy have been analyzed in detail. It is proved that RIKES nonlinear confocal microscopy can simultaneously provide more information than two-photon confocal microscopy concerning molecular vibration mode, vibration orientation and optically induced molecular reorientation, etc. It is shown that RIKES nonlinear confocal microscopy significantly enhances the spatial resolution and imaging quality of confocal microscopy and achieves much higher resolution than that of two-photon confocal microscopy.

  5. Near-infrared-excited confocal Raman spectroscopy advances in vivo diagnosis of cervical precancer.

    Science.gov (United States)

    Duraipandian, Shiyamala; Zheng, Wei; Ng, Joseph; Low, Jeffrey J H; Ilancheran, Arunachalam; Huang, Zhiwei

    2013-06-01

    Raman spectroscopy is a unique optical technique that can probe the changes of vibrational modes of biomolecules associated with tissue premalignant transformation. This study evaluates the clinical utility of confocal Raman spectroscopy over near-infrared (NIR) autofluorescence (AF) spectroscopy and composite NIR AF/Raman spectroscopy for improving early diagnosis of cervical precancer in vivo at colposcopy. A rapid NIR Raman system coupled with a ball-lens fiber-optic confocal Raman probe was utilized for in vivo NIR AF/Raman spectral measurements of the cervix. A total of 1240 in vivo Raman spectra [normal (n=993), dysplasia (n=247)] were acquired from 84 cervical patients. Principal components analysis (PCA) and linear discriminant analysis (LDA) together with a leave-one-patient-out, cross-validation method were used to extract the diagnostic information associated with distinctive spectroscopic modalities. The diagnostic ability of confocal Raman spectroscopy was evaluated using the PCA-LDA model developed from the significant principal components (PCs) [i.e., PC4, 0.0023%; PC5, 0.00095%; PC8, 0.00022%, (pspectroscopy coupled with PCA-LDA modeling yielded the diagnostic accuracy of 84.1% (a sensitivity of 81.0% and a specificity of 87.1%) for in vivo discrimination of dysplastic cervix. The receiver operating characteristic curves further confirmed that the best classification was achieved using confocal Raman spectroscopy compared to the composite NIR AF/Raman spectroscopy or NIR AF spectroscopy alone. This study illustrates that confocal Raman spectroscopy has great potential to improve early diagnosis of cervical precancer in vivo during clinical colposcopy.

  6. Off-confocal Raman spectroscopy (OCRS) for subsurface measurements in layered turbid samples

    Science.gov (United States)

    Khan, Khan Mohammad; Ghosh, Nirmalya; Majumder, Shovan Kumar

    2016-09-01

    We report, for the first time, the development of a depth-sensitive Raman spectroscopy system for investigating subsurface depths in a layered turbid sample using the concept of varying Raman collection zones, while keeping the point of illumination fixed on the surface of the target sample. The system makes use of a conventional confocal Raman configuration and realizes the variation in Raman collection zones employing off-confocal detection. This is effected by moving the tip of the Raman detection fiber (acting as the pinhole aperture) from the focus of the Raman collection objective either by taking the point of detection away from the objective (along its axis) or bringing it closer to the objective (along the same axis), thereby essentially offering two ways of enabling subsurface interrogation at a given time. Another important attraction of the approach is that it can be used for analyzing layered turbid samples at depths beyond the reach of the conventional confocal Raman, though not at the cost of any further modifications in its instrumentation. Furthermore, the illumination point remains fixed on the sample surface and no adjustment is required in the sample arm, which indeed are significant advantages for depth-sensitive measurements in situ from layered turbid samples, particularly those having irregular surfaces (like biological tissues). The ability of the system to recover Raman spectra of the subsurface layer was demonstrated using a layered non-biological phantom and a biological tissue sample.

  7. [Revealing the chemical changes of tea cell wall induced by anthracnose with confocal Raman microscopy].

    Science.gov (United States)

    Li, Xiao-li; Luo, Liu-bin; Hu, Xiao-qian; Lou, Bing-gan; He, Yong

    2014-06-01

    Healthy tea and tea infected by anthracnose were first studied by confocal Raman microscopy to illustrate chemical changes of cell wall in the present paper. Firstly, Raman spectra of both healthy and infected sample tissues were collected with spatial resolution at micron-level, and ultrastructure of healthy and infected tea cells was got from scanning electron microscope. These results showed that there were significant changes in Raman shift and Raman intensity between healthy and infected cell walls, indicating that great differences occurred in chemical compositions of cell walls between healthy and infected samples. In details, intensities at many Raman bands which were closely associated with cellulose, pectin, esters were reduced after infection, revealing that the content of chemical compounds such as cellulose, pectin, esters was decreased after infection. Subsequently, chemical imaging of both healthy and infected tea cell walls were realized based on Raman fingerprint spectra of cellulose and microscopic spatial structure. It was found that not only the content of cellulose was reduced greatly after infection, but also the ordered structure of cellulose was destroyed by anthracnose infection. Thus, confocal Raman microscopy was shown to be a powerful tool to detect the chemical changes in cell wall of tea caused by anthracnose without any chemical treatment or staining. This research firstly applied confocal Raman microscopy in phytopathology for the study of interactive relationship between host and pathogen, and it will also open a new way for intensive study of host-pathogen at cellular level.

  8. Nonlocal Effects in the Confocal μ-Raman Characterization of Inhomogeneous Polymer Coatings

    Science.gov (United States)

    Rodriguez, R.; Vargas, S.; Estevez, M.

    2010-11-01

    The confocal μ-Raman technique was used to characterize the morphology of inhomogeneous anti-graffiti coatings; for these systems, the antiadherent molecules were segregated to the external (exposed) surface forming a layer whose thickness was determined. The confocal data from these inhomogeneous coatings contains nonlocal contributions because the light scattered from sources near the specific specimen under analysis (the focused region) could not be completely rejected by the spatial filter of the confocal device. These nonlocal contributions had important effects in the Raman spectra, modifying the bands height profiles of homogeneous and inhomogeneous materials allowing their identification. Taking into account these nonlocal effects, it was possible to interpret correctly the relative intensities of the Raman bands and characterize properly the inhomogeneous coatings.

  9. Determination of Nanogram Microparticles from Explosives after Real Open-Air Explosions by Confocal Raman Microscopy.

    Science.gov (United States)

    Zapata, Félix; García-Ruiz, Carmen

    2016-07-05

    Explosives are increasingly being used for terrorist attacks to cause devastating explosions. The detection of their postblast residues after an explosion is a high challenge, which has been barely investigated, particularly using spectroscopic techniques. In this research, a novel methodology using confocal Raman microscopy has been developed for the analysis of postblast residues from 10 open-air explosions caused by 10 different explosives (TNT, RDX, PETN, TATP, HMTD, dynamite, black powder, ANFO, chloratite, and ammonal) commonly used in improvised explosive devices. The methodology for the determination of postblast particles from explosives consisted of examining the samples surfaces with both the naked eye, first, and microscopically (10× and 50×), immediately afterward; and finally, analyzing the selected residues by confocal Raman spectroscopy in order to identify the postblast particles from explosives. Interestingly, confocal Raman microscopy has demonstrated to be highly suitable to rapidly, selectively, and noninvasively analyze postblast microscopic particles from explosives up to the nanogram range.

  10. Measuring skin penetration by confocal Raman microscopy (CRM): correlation to results from conventional experiments

    Science.gov (United States)

    Lunter, Dominique; Daniels, Rolf

    2016-03-01

    Confocal Raman microscopy has become an advancing technique in the characterization of drug transport into the skin. In this study the skin penetration of a local anesthetic from a semisolid preparation was investigated. Furthermore, the effect of the chemical enhancers propylene glycol and POE-23-lauryl ether on its penetration was investigated. The results show that confocal Raman microscopy may provide detailed information on the penetration of APIs into the skin and may elucidate their distribution within the skin with high resolution. The results of the CRM analysis are fully in line with those of conventional permeation and penetration experiments.

  11. In vivo confocal Raman microspectroscopy of the skin: Noninvasive determination of molecular concentration profiles

    NARCIS (Netherlands)

    P.J. Caspers (Peter); G.W. Lucassen (Gerald); E.A. Carter (Elizabeth); H.A. Bruining (Hajo); G.J. Puppels (Gerwin)

    2001-01-01

    textabstractConfocal Raman spectroscopy is introduced as a noninvasive in vivo optical method to measure molecular concentration profiles in the skin. It is shown how it can be applied to determine the water concentration in the stratum corneum as a function of distance to the skin surface, with a

  12. Sensitive Skin: Assessment of the Skin Barrier Using Confocal Raman Microspectroscopy

    NARCIS (Netherlands)

    Richters, R.J.H.; Falcone, D.; Uzunbajakava, N.E.; Varghese, B.; Caspers, P.J.; Puppels, G.J.; Erp, P.E.J. van; Kerkhof, P.C.M. van de

    2017-01-01

    BACKGROUND/AIMS: Sensitive skin (SS), a frequently reported condition in the Western world, has been suggested to be underlined by an impaired skin barrier. The aim of this study was to investigate the skin barrier molecular composition in SS subjects using confocal Raman microspectroscopy (CRS),

  13. Dental pulp stem cells (DPSCs) differentiation study by confocal Raman microscopy

    Science.gov (United States)

    Salehi, H.; Collart-Dutilleul, P.-Y.; Gergely, C.; Cuisinier, F. J. G.

    2014-03-01

    Regenerative medicine brings a huge application for Mesenchymal stem cells such as Dental Pulp Stem Cells (DPSCs). Confocal Raman microscopy, a non-invasive, label free , real time and high spatial resolution imaging technique is used to study osteogenic differentiation of DPSCs. Integrated Raman intensities in the 2800-3000 cm-1 region (C-H stretching) and 960 cm-1 peak (phosphate PO4 3-) were collected. In Dental Pulp Stem Cells 21st day differentiated in buffer solution, phosphate peaks ν1 PO4 3- (first vibrational mode) at 960cm-1 and ν2 PO4 3- at 430cm-1 and ν4 PO4 3- at 585cm-1 are obviously present. Confocal Raman microscopy enables the detection of cell differentiation and it can be used to investigate clinical stem cell research.

  14. Investigating Effects of Proteasome Inhibitor on Multiple Myeloma Cells Using Confocal Raman Microscopy

    Directory of Open Access Journals (Sweden)

    Jeon Woong Kang

    2016-12-01

    Full Text Available Due to its label-free and non-destructive nature, applications of Raman spectroscopic imaging in monitoring therapeutic responses at the cellular level are growing. We have recently developed a high-speed confocal Raman microscopy system to image living biological specimens with high spatial resolution and sensitivity. In the present study, we have applied this system to monitor the effects of Bortezomib, a proteasome inhibitor drug, on multiple myeloma cells. Cluster imaging followed by spectral profiling suggest major differences in the nuclear and cytoplasmic contents of cells due to drug treatment that can be monitored with Raman spectroscopy. Spectra were also acquired from group of cells and feasibility of discrimination among treated and untreated cells using principal component analysis (PCA was accessed. Findings support the feasibility of Raman technologies as an alternate, novel method for monitoring live cell dynamics with minimal external perturbation.

  15. Analysis of the in vivo confocal Raman spectral variability in human skin

    Science.gov (United States)

    Mogilevych, Borys; dos Santos, Laurita; Rangel, Joao L.; Grancianinov, Karen J. S.; Sousa, Mariane P.; Martin, Airton A.

    2015-06-01

    Biochemical composition of the skin changes in each layer and, therefore, the skin spectral profile vary with the depth. In this work, in vivo Confocal Raman spectroscopy studies were performed at different skin regions and depth profile (from the surface down to 10 μm) of the stratum corneum, to verify the variability and reproducibility of the intra- and interindividual Raman data. The Raman spectra were collected from seven healthy female study participants using a confocal Raman system from Rivers Diagnostic, with 785 nm excitation line and a CCD detector. Measurements were performed in the volar forearm region, at three different points at different depth, with the step of 2 μm. For each depth point, three spectra were acquired. Data analysis included the descriptive statistics (mean, standard deviation and residual) and Pearson's correlation coefficient calculation. Our results show that inter-individual variability is higher than intraindividual variability, and variability inside the SC is higher than on the skin surface. In all these cases we obtained r values, higher than 0.94, which correspond to high correlation between Raman spectra. It reinforces the possibility of the data reproducibility and direct comparison of in vivo results obtained with different study participants of the same age group and phototype.

  16. In-situ detection of drugs-of-abuse on clothing using confocal Raman microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Ali, Esam M.A. [Raman Spectroscopy Group, University Analytical Centre, Division of Chemical and Forensic Sciences, University of Bradford, Bradford BD7 1DP (United Kingdom); Edwards, Howell G.M. [Raman Spectroscopy Group, University Analytical Centre, Division of Chemical and Forensic Sciences, University of Bradford, Bradford BD7 1DP (United Kingdom)], E-mail: h.g.m.edwards@bradford.ac.uk; Hargreaves, Michael D.; Scowen, Ian J. [Raman Spectroscopy Group, University Analytical Centre, Division of Chemical and Forensic Sciences, University of Bradford, Bradford BD7 1DP (United Kingdom)

    2008-05-12

    This study describes the application of confocal Raman microscopy to the detection and identification of drugs-of-abuse in situ on undyed natural synthetic fibres, and coloured textile specimens. Raman spectra were obtained from drug particles trapped between the fibres of the specimens. Pure samples of cocaine hydrochloride and N-methyl-3,4-methylenedioxy-amphetamine HCl (MDMA-HCl) were used in this study. Raman spectra were collected from drug particles of an average size in the range 5-15 {mu}m. Despite the presence of spectral bands arising from the natural and synthetic polymer and dyed textiles, the drugs could be identified by their characteristic Raman bands. If necessary, interfering bands could be successfully removed by spectral subtraction. Furthermore, Raman spectra were recorded from drug particles trapped between the fibres of highly fluorescent specimens. Interference from the fibres, including background fluorescence, was overcome by careful focusing of the confocal beam and the resulting spectra allow ready differentiation from interference from the fibres substrate bands. Spectra of several drugs-of-abuse on dyed and undyed clothing substrates were readily obtained within 3 min with little or no sample preparation and with no alteration of the evidential material.

  17. Confocal Raman microscopy for in depth analysis in the field of cultural heritage

    Science.gov (United States)

    Lorenzetti, G.; Striova, J.; Zoppi, A.; Castellucci, E. M.

    2011-05-01

    In the field of cultural heritage, the main concern when a sample is analyzed is its safeguard, and this means that non-destructive techniques are required. In this work, we show how confocal Raman microscopy (CRM) may be successfully applied in the study of works of art as a valuable alternative to other well established techniques. CRM with a metallurgical objective was tested for the in depth study of thin samples that are of interest in the field of cultural heritage. The sensitivity of the instrumentation was first evaluated by analyzing single layers of pure polyethylene terephthalate (PET) films having a thickness of 12, 25, and 50 μm, respectively, and a multilayer sample of polypropylene (PP) and polyethylene (PE). Subsequently, the technique was applied to the analysis of historical dyed cotton yarns in order to check whether it was possible to achieve a better discrimination of the fibres' signals for an easier identification. A substantial improvement of the signal to noise ratio was found in the confocal arrangement with respect to the non-confocal one, suggesting the use of this technique for this kind of analysis in the field of cultural heritage. Furthermore, Raman spectroscopy in confocal configuration was exploited in the evaluation of cleaning performed on the mural painting specimens, treated with acrylic resin (Paraloid B72). Confocal Raman experiments were performed before and after laser cleaning (at different conditions) in order to monitor the presence and to approximate the polymer thickness: the method proved to be a valid comparative tool in assessment of cleaning efficiencies.

  18. Confocal Raman studies in determining crystalline nature of PECVD grown Si nanowires

    Energy Technology Data Exchange (ETDEWEB)

    Ahmed, Nafis; Bhargav, P. Balaji; Ramasamy, P. [SSN Research Centre, Kalavakkam-603110, Tamilnadu (India); Department of Physics, SSN College of Engineering, Kalavakkam-603110, Tamilnadu (India); Sivadasan, A. K.; Tyagi, A. K.; Dhara, S., E-mail: dhara@igcar.gov.in [Surface and Nanoscience Division, Indira Gandhi Centre for Atomic Research, Kalpakkam-603102 (India); Amirthapandian, S.; Panigrahi, B. K. [Materials Physics Division, Indira Gandhi Centre for Atomic Research, Kalpakkam-603102 (India); Bhattacharya, S. [SSN Research Centre, Kalavakkam-603110, Tamilnadu (India)

    2015-06-24

    Silicon nanowires of diameter ∼200 nm and length of 2-4 µm are grown in the plasma enhanced chemical vapour deposition technique using nanoclustered Au catalyst assisted vapour-liquid-solid process. The crystallinity in the as-grown and annealed samples is studied using confocal Raman spectroscopic studies. Amorphous phase is formed in the as-grown samples. Structural studies using high resolution transmission electron microscopy confirm the polycrystalline nature in the annealed sample.

  19. Template confined synthesis of amorphous carbon nanotubes and its confocal Raman microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Maity, Supratim [Thin Film and Nanoscience Laboratory, Department of Physics, Jadavpur University, Kolkata -700 032 (India); Roychowdhury, Tuhin [School of Materials Science and Nanotechnology, Jadavpur University, Kolkata -700 032 (India); Chattopadhyay, Kalyan Kumar, E-mail: kalyan-chattopadhyay@yahoo.com [Thin Film and Nanoscience Laboratory, Department of Physics, Jadavpur University, Kolkata -700 032, India and School of Materials Science and Nanotechnology, Jadavpur University, Kolkata -700 032 (India)

    2014-04-24

    Amorphous carbon nanotubes (aCNTs) were synthesized by AAO (anodic aluminum oxide) template at a temperature 500 °C in nitrogen atmosphere using the citric acid as a carbon source without the help of any catalyst particles. Morphological analysis of the as prepared samples was carried out by field emission scanning electron microscopy (FESEM). Confocal Raman imaging has been studied and an attempt has been made to find out the graphitic (sp{sup 2}) and disordered phase of the CNTs.

  20. Label-free detection of tumor markers in a colon carcinoma tumor progression model by confocal Raman microspectroscopy

    Science.gov (United States)

    Scalfi-Happ, Claudia; Rück, Angelika; Udart, Martin; Hauser, Carmen; Dürr, Christine; Kriebel, Martin

    2013-06-01

    Living colon carcinoma cells were investigated by confocal Raman microspectroscopy. An in vitro model of tumor progression was established. Evaluation of data sets by cluster analysis reveals that lipid bodies might be a valuable diagnostic parameter for early carcinogenesis.

  1. Quantitative Analysis of Microbicide Concentrations in Fluids, Gels and Tissues Using Confocal Raman Spectroscopy

    Science.gov (United States)

    Chuchuen, Oranat; Henderson, Marcus H.; Sykes, Craig; Kim, Min Sung; Kashuba, Angela D. M.; Katz, David F.

    2013-01-01

    Topical vaginal anti-HIV microbicides are an important focus in female-based strategies to prevent the sexual transmission of HIV. Understanding microbicide pharmacokinetics is essential to development, characterization and implementation of efficacious microbicide drug delivery formulations. Current methods to measure drug concentrations in tissue (e.g., LC-MS/MS, liquid chromatography coupled with tandem mass spectrometry) are highly sensitive, but destructive and complex. This project explored the use of confocal Raman spectroscopy to detect microbicide drugs and to measure their local concentrations in fluids, drug delivery gels, and tissues. We evaluated three candidate microbicide drugs: tenofovir, Dapivirine and IQP-0528. Measurements were performed in freshly excised porcine buccal tissue specimens, gel vehicles and fluids using two Horiba Raman microscopes, one of which is confocal. Characteristic spectral peak calibrations for each drug were obtained using serial dilutions in the three matrices. These specific Raman bands demonstrated strong linear concentration dependences in the matrices and were characterized with respect to their unique vibrational signatures. At least one specific Raman feature was identified for each drug as a marker band for detection in tissue. Sensitivity of detection was evaluated in the three matrices. A specific peak was also identified for tenofovir diphosphate, the anti-HIV bioactive product of tenofovir after phosphorylation in host cells. Z-scans of drug concentrations vs. depth in excised tissue specimens, incubated under layers of tenofovir solution in a Transwell assay, showed decreasing concentration with depth from the surface into the tissue. Time-dependent concentration profiles were obtained from tissue samples incubated in the Transwell assay, for times ranging 30 minutes - 6 hours. Calibrations and measurements from tissue permeation studies for tenofovir showed good correlation with gold standard LC-MS/MS data

  2. Quantitative analysis of microbicide concentrations in fluids, gels and tissues using confocal Raman spectroscopy.

    Directory of Open Access Journals (Sweden)

    Oranat Chuchuen

    Full Text Available Topical vaginal anti-HIV microbicides are an important focus in female-based strategies to prevent the sexual transmission of HIV. Understanding microbicide pharmacokinetics is essential to development, characterization and implementation of efficacious microbicide drug delivery formulations. Current methods to measure drug concentrations in tissue (e.g., LC-MS/MS, liquid chromatography coupled with tandem mass spectrometry are highly sensitive, but destructive and complex. This project explored the use of confocal Raman spectroscopy to detect microbicide drugs and to measure their local concentrations in fluids, drug delivery gels, and tissues. We evaluated three candidate microbicide drugs: tenofovir, Dapivirine and IQP-0528. Measurements were performed in freshly excised porcine buccal tissue specimens, gel vehicles and fluids using two Horiba Raman microscopes, one of which is confocal. Characteristic spectral peak calibrations for each drug were obtained using serial dilutions in the three matrices. These specific Raman bands demonstrated strong linear concentration dependences in the matrices and were characterized with respect to their unique vibrational signatures. At least one specific Raman feature was identified for each drug as a marker band for detection in tissue. Sensitivity of detection was evaluated in the three matrices. A specific peak was also identified for tenofovir diphosphate, the anti-HIV bioactive product of tenofovir after phosphorylation in host cells. Z-scans of drug concentrations vs. depth in excised tissue specimens, incubated under layers of tenofovir solution in a Transwell assay, showed decreasing concentration with depth from the surface into the tissue. Time-dependent concentration profiles were obtained from tissue samples incubated in the Transwell assay, for times ranging 30 minutes - 6 hours. Calibrations and measurements from tissue permeation studies for tenofovir showed good correlation with gold

  3. [Studies on Effect of Alkali Pretreatment on Anaerobic Digestion of Rice Straw with Confocal Raman Microscopy].

    Science.gov (United States)

    Xia, Yi-hua; Luo, Liu-bin; Li, Xiao-li; He, Yong; Sheng, Kui-chuan

    2015-03-01

    NaOH pretreatment is a convenient and effective method which is widely used in rice straw anaerobic digestion. But the mechanism of the alkaline (NaOH) hydrolysis of biopolymers compositions and polymeric cross-linked network structures of rice straw cell wall need further study. This paper firstly studied the effect and mechanism of alkali pretreatment on anaerobic digestion and biogas production of rice straw by using a combination of confocal Raman microscopy and transmission electron microscope. First, the original rice straw and the rice straw pretreated by NaOH were taken for mapping scanning by confocal Raman microscopy with micron-scale spatial resolution. Then principal component analysis was adopted to extract main information of Raman spectra, it could be found that the two types of samples were respectively presented with ray-like distribution in the first two principal component space, which were with cumulative contribution of 99%. And there was a clear boundary between the two types of samples without any overlapping, indicating that there was a significant difference of Raman spectral characteristic between original rice leaf and rice leaf pretreated by NaOH. Further analysis of the loading weights of the first two principal components showed that the Raman peaks at 1 739, 1 508 and 1 094 cm(-1) were the important bands, and these three Raman peaks were attributed to the scattering of hemicellulose, cellulose and lignin respectively. Following, chemical imaging analysis of hemicellulose, cellulose and lignin were achieved by combining these Raman peaks and microscopic image information. It could be found that the NaOH pretreatment resulted in a loss of dense spatial uniformity structure of tissue and great decreases of the contents of these three ingredients, particularly lignin. It can be concluded that it is feasible to non-destructively measure hemicellulose, lignin and cellulose in rice straw tissue by confocal Raman microscopy, and to achieve

  4. In vivo confocal Raman spectroscopy study of the vitamin A derivative perfusion through human skin

    Science.gov (United States)

    dos Santos, Laurita; Téllez Soto, Claudio A.; Favero, Priscila P.; Martin, Airton A.

    2016-03-01

    In vivo confocal Raman spectroscopy is a powerful non-invasive technique able to analyse the skin constituents. This technique was applied to transdermal perfusion studies of the vitamin A derivative in human skin. The composition of the stratum corneum (lipid bilayer) is decisive for the affinity and transport of the vitamin through skin. The vitamin A is significantly absorbed by human skin when applied with water in oil emulsion or hydro-alcoholic gel. The purpose of this study is to elucidate the behaviour of vitamin A derivative into human skin without the presence of enhancers. The results showed that the intensity band of the derivative (around 1600 cm-1), which represents the -C=O vibrational mode, was detected in different stratum corneum depths (up to 20 μm). This Raman peak of vitamin A derivative has non-coincident band with the Raman spectra of the skin epidermis, demonstrating that compound penetrated in forearm skin.

  5. Fast mapping of inhomogeneities in the popular metallic perovskite Nb:SrTiO{sub 3} by confocal Raman microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Rodenbuecher, Christian [Forschungszentrum Juelich GmbH, Peter Gruenberg Institut (PGI-7), JARA, 52425 Juelich (Germany); Jauss, Andrea [WITec GmbH, 89081, Ulm (Germany); Havel, Viktor [RWTH Aachen, Institut fuer Werkstoffe der Elektrotechnik 2, 52056, Aachen (Germany); Waser, Rainer [Forschungszentrum Juelich GmbH, Peter Gruenberg Institut (PGI-7), JARA, 52425 Juelich (Germany); RWTH Aachen, Institut fuer Werkstoffe der Elektrotechnik 2, 52056, Aachen (Germany); Szot, Kristof [Forschungszentrum Juelich GmbH, Peter Gruenberg Institut (PGI-7), JARA, 52425 Juelich (Germany); University of Silesia, A. Chelkowski Institute of Physics, 40-007, Katowice (Poland)

    2014-09-15

    Confocal Raman microscopy was applied in order to investigate the homogeneity of donor doping in Nb:SrTiO{sub 3} single crystals. Measurements of local Raman spectra revealed a systematic relation between the intensity of the Raman signal and the donor content of the crystals. We successfully elaborated a correspondence between the electronic structure and the intensity of the Raman lines using a crystal with macroscopic inhomogeneity as a demonstration sample. By mapping the distribution of the intensity of the Raman signal, we identified a characteristic inhomogeneous structure related to the presence of clusters with sizes of 5 μm to 20 μm, indicating inhomogeneous donor distribution caused by flaws introduced during crystal growth. Hence, we propose confocal Raman microscopy as a convenient technique for investigating the homogeneity and quality of doped perovskite surfaces, which are needed for various technological applications. (copyright 2014 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  6. Detection of advanced glycation end products (AGEs) on human skin by in vivo confocal Raman spectroscopy

    Science.gov (United States)

    Martin, A. A.; Pereira, L.; Ali, S. M.; Pizzol, C. D.; Tellez, C. A.; Favero, P. P.; Santos, L.; da Silva, V. V.; Praes, C. E. O.

    2016-03-01

    The aging process involves the reduction in the production of the major components of skin tissue. During intrinsic aging and photoaging processes, in dermis of human skin, fibroblasts become senescent and have decreased activity, which produce low levels of collagen. Moreover, there is accumulation of advanced glycation end products (AGEs). AGEs have incidence in the progression of age-related diseases, principally in diabetes mellitus and in Alzheimer's diseases. AGEs causes intracellular damage and/or apoptosis leading to an increase of the free radicals, generating a crosslink with skin proteins and oxidative stress. The aim of this study is to detect AGEs markers on human skin by in vivo Confocal Raman spectroscopy. Spectra were obtained by using a Rivers Diagnostic System, 785 nm laser excitation and a CCD detector from the skin surface down to 120 μm depth. We analyzed the confocal Raman spectra of the skin dermis of 30 women volunteers divided into 3 groups: 10 volunteers with diabetes mellitus type II, 65-80 years old (DEW); 10 young healthy women, 20-33 years old (HYW); and 10 elderly healthy women, 65-80 years old (HEW). Pentosidine and glucosepane were the principally identified AGEs in the hydroxyproline and proline Raman spectral region (1000-800 cm-1), in the 1.260-1.320 cm-1 region assignable to alpha-helical amide III modes, and in the Amide I region. Pentosidine and glucosepane calculated vibrational spectra were performed through Density Functional Theory using the B3LYP functional with 3-21G basis set. Difference between the Raman spectra of diabetic elderly women and healthy young women, and between healthy elderly women and healthy young women were also obtained with the purpose of identifying AGEs Raman bands markers. AGEs peaks and collagen changes have been identified and used to quantify the glycation process in human skin.

  7. Assessing strain mapping by electron backscatter diffraction and confocal Raman microscopy using wedge-indented Si

    Energy Technology Data Exchange (ETDEWEB)

    Friedman, Lawrence H.; Vaudin, Mark D.; Stranick, Stephan J.; Stan, Gheorghe; Gerbig, Yvonne B.; Osborn, William; Cook, Robert F., E-mail: robert.cook@nist.gov

    2016-04-15

    The accuracy of electron backscatter diffraction (EBSD) and confocal Raman microscopy (CRM) for small-scale strain mapping are assessed using the multi-axial strain field surrounding a wedge indentation in Si as a test vehicle. The strain field is modeled using finite element analysis (FEA) that is adapted to the near-indentation surface profile measured by atomic force microscopy (AFM). The assessment consists of (1) direct experimental comparisons of strain and deformation and (2) comparisons in which the modeled strain field is used as an intermediate step. Direct experimental methods (1) consist of comparisons of surface elevation and gradient measured by AFM and EBSD and of Raman shifts measured and predicted by CRM and EBSD, respectively. Comparisons that utilize the combined FEA–AFM model (2) consist of predictions of distortion, strain, and rotation for comparison with EBSD measurements and predictions of Raman shift for comparison with CRM measurements. For both EBSD and CRM, convolution of measurements in depth-varying strain fields is considered. The interconnected comparisons suggest that EBSD was able to provide an accurate assessment of the wedge indentation deformation field to within the precision of the measurements, approximately 2×10{sup −4} in strain. CRM was similarly precise, but was limited in accuracy to several times this value. - Highlights: • We map strain by electron backscatter diffraction and confocal Raman microscopy. • The test vehicle is the multi-axial strain field of wedge-indented silicon. • Strain accuracy is assessed by direct experimental intercomparison. • Accuracy is also assessed by atomic force microscopy and finite element analyses. • Electron diffraction measurements are accurate; Raman measurements need refinement.

  8. Confocal Raman spectroscopy system for noncontact scanning of ocular tissues: an in vitro study

    Science.gov (United States)

    Jongsma, Franciscus H.; Erckens, Roel J.; Wicksted, James P.; Bauer, Noel J.; Hendrikse, Fred; March, Wayne F.; Motamedi, Massoud

    1997-11-01

    A long-working-distance fiber-optic-based confocal Raman spectroscopy (CRS) system, operating in the backscatter mode, was developed for rapid noninvasive characterization of ocular tissue. In vitro near-real-time axial scanning through ocular tissue was achieved using a CCD camera and a high-numerical- aperture long-working-distance microscope objective in a telecentric configuration. The system provides high spatial resolution (20 to 150 micrometers) of transparent ocular tissues up to 13 mm deep into the eye in a noncontact fashion while utilizing low argon-laser power and rapid scanning times (25 mJ), yielding a SNR range from 30 to 75. To test the performance of the system for characterizing ocular tissue, Raman spectra from rabbit eyes were obtained in vitro. Axial scans of the cornea, the aqueous humor, an the lens provided discrete and specific Raman spectra from each tissue, in both the lower and the higher wave-number region. Characteristic Raman signals common to all tissues are the OH vibrations (1650 and 3100 to 3700 cm-1) and the vibrations corresponding to amino acids (phenylalanine at 1003 cm-1, tryptophan at 760 and 881 cm-1, and tyrosine at 646 cm-1). The ocular lens can be identified by three distinct peaks (aromatic and aliphatic CH stretching and OH bending modes), of which the aromatic CH stretching mode (approximately equals 3057 cm-1) is lens-specific. The cornea can be identified by the presence of two distinct peaks (aliphatic CH stretching and OH bending) and the absence of the aromatic CH stretching mode. The aqueous humor can be identified by the presence of the OH bending mode and the lack of the both CH stretching modes. A long-working-distance confocal Raman spectroscopy system may offer a novel technique for the noncontact spatially resolved biochemical characterization of various tissue layers of the anterior segment of the eye.

  9. Quantifying adhesive penetration in adhesive/dentin interface using confocal Raman microspectroscopy.

    Science.gov (United States)

    Wang, Yong; Spencer, Paulette

    2002-01-01

    Confocal Raman microspectroscopy (CRM) provides an important and novel means of analyzing the chemical composition of the adhesive/dentin (a/d) interface. The purpose of this study was to develop a method for quantitative determination of the degree of adhesive penetration at the a/d interface using CRM. Three commercial dentin adhesive systems [Scotchbond Multipurpose Plus (SBMP+), Single Bond (SB), and Primer Bond NT (PBNT)] based on the total etch and "wet" bonding technique were examined in this study. Human dentin specimens treated with these adhesives were analyzed with CRM mapping across the a/d interface. Also, Raman spectra were collected on model mixtures of adhesive and type I collagen, and the ratios of the relative intensities of the Raman bands corresponding to adhesive and collagen were used for the construction of calibration curves. By comparing the Raman band ratios of interface specimens to the calibration curves, the percent of adhesive as a function of spatial position across the a/d interface was determined. The results show that there is a gradual decrease in penetration as a function of position for all three adhesive systems while the adhesive concentration gradient decreases in the order of SBMP+ > SB > PBNT. These differences in penetration of the three adhesives at the a/d interface also are discussed relative to the composition and phase segregation in adhesives. Additionally, our results indicate that confocal Raman microspectroscopy is a reliable in situ analytical technique for simple and rapid quantitative determination of adhesive penetration at its interface with prepared dentin. Copyright 2001 John Wiley & Sons, Inc.

  10. Demonstration of the Protein Involvement in Cell Electropermeabilization using Confocal Raman Microspectroscopy

    Science.gov (United States)

    Azan, Antoine; Untereiner, Valérie; Gobinet, Cyril; Sockalingum, Ganesh D.; Breton, Marie; Piot, Olivier; Mir, Lluis M.

    2017-01-01

    Confocal Raman microspectroscopy was used to study the interaction between pulsed electric fields and live cells from a molecular point of view in a non-invasive and label-free manner. Raman signatures of live human adipose-derived mesenchymal stem cells exposed or not to pulsed electric fields (8 pulses, 1 000 V/cm, 100 μs, 1 Hz) were acquired at two cellular locations (nucleus and cytoplasm) and two spectral bands (600–1 800 cm−1 and 2 800–3 100 cm−1). Vibrational modes of proteins (phenylalanine and amide I) and lipids were found to be modified by the electropermeabilization process with a statistically significant difference. The relative magnitude of four phenylalanine peaks decreased in the spectra of the pulsed group. On the contrary, the relative magnitude of the amide I band at 1658 cm−1 increased by 40% when comparing pulsed and control group. No difference was found between the control and the pulsed group in the high wavenumber spectral band. Our results reveal the modification of proteins in living cells exposed to pulsed electric fields by means of confocal Raman microspectroscopy. PMID:28102326

  11. Novel Method for Differentiating Histological Types of Gastric Adenocarcinoma by Using Confocal Raman Microspectroscopy.

    Science.gov (United States)

    Hsu, Chih-Wei; Huang, Chia-Chi; Sheu, Jeng-Horng; Lin, Chia-Wen; Lin, Lien-Fu; Jin, Jong-Shiaw; Chau, Lai-Kwan; Chen, Wenlung

    2016-01-01

    Gastric adenocarcinoma, a single heterogeneous disease with multiple epidemiological and histopathological characteristics, accounts for approximately 10% of cancers worldwide. It is categorized into four histological types: papillary adenocarcinoma (PAC), tubular adenocarcinoma (TAC), mucinous adenocarcinoma (MAC), and signet ring cell adenocarcinoma (SRC). Effective differentiation of the four types of adenocarcinoma will greatly improve the treatment of gastric adenocarcinoma to increase its five-year survival rate. We reported here the differentiation of the four histological types of gastric adenocarcinoma from the molecularly structural viewpoint of confocal Raman microspectroscopy. In total, 79 patients underwent laparoscopic or open radical gastrectomy during 2008-2011: 21 for signet ring cell carcinoma, 21 for tubular adenocarcinoma, 14 for papillary adenocarcinoma, 6 for mucinous carcinoma, and 17 for normal gastric mucosas obtained from patients underwent operation for other benign lesions. Clinical data were retrospectively reviewed from medical charts, and Raman data were processed and analyzed by using principal component analysis (PCA) and linear discriminant analysis (LDA). Two-dimensional plots of PCA and LDA clearly demonstrated that the four histological types of gastric adenocarcinoma could be differentiated, and confocal Raman microspectroscopy provides potentially a rapid and effective method for differentiating SRC and MAC from TAC or PAC.

  12. Confocal Raman mapping of collagen cross-link and crystallinity of human dentin-enamel junction

    Science.gov (United States)

    Slimani, Amel; Nouioua, Fares; Desoutter, Alban; Levallois, Bernard; Cuisinier, Frédéric J. G.; Tassery, Hervé; Terrer, Elodie; Salehi, Hamideh

    2017-08-01

    The separation zone between enamel and dentin [dentin-enamel junction (DEJ)] with different properties in biomechanical composition has an important role in preventing crack propagation from enamel to dentin. The understanding of the chemical structure (inorganic and organic components), physical properties, and chemical composition of the human DEJ could benefit biomimetic materials in dentistry. Spatial distribution of calcium phosphate crystallinity and the collagen crosslinks near DEJ were studied using confocal Raman microscopy and calculated by different methods. To obtain collagen crosslinking, the ratio of two peaks 1660 cm-1 over 1690 cm-1 (amide I bands) is calculated. For crystallinity, the inverse full-width at half maximum of phosphate peak at 960 cm-1, and the ratio of two Raman peaks of phosphate at 960/950 cm-1 is provided. In conclusion, the study of chemical and physical properties of DEJ provides many benefits in the biomaterial field to improve the synthesis of dental materials in respect to the natural properties of human teeth. Confocal Raman microscopy as a powerful tool provides the molecular structure to identify the changes along DEJ and can be expanded for other mineralized tissues.

  13. Confocal Raman spectroscopy to trace lipstick with their smudges on different surfaces.

    Science.gov (United States)

    López-López, Maria; Özbek, Nil; García-Ruiz, Carmen

    2014-06-01

    Lipsticks are very popular cosmetic products that can be transferred by contact to different surfaces, being important forensic evidence with an intricate analysis if they are found in a crime scene. This study evaluates the use of confocal Raman microscopy at 780 nm excitation wavelength for the nondestructive identification of 49 lipsticks of different brands and colors, overcoming the lipstick fluorescence problem reported by previous works using other laser wavelengths. Although the lipsticks samples showed some fluorescence, this effect was not so intense to completely overwhelm the Raman spectra. Lipsticks smudges on twelve different surfaces commonly stained with these samples were also analyzed. In the case of the surfaces, some of them provided several bands to the smudge spectra compromising the identification of the lipstick. For these samples spectral subtraction of the interfering bands from the surface was performed. Finally, five different red lipsticks with very similar color were measured on different surfaces to evaluate the lipstick traceability with their smudges even on interfering surfaces. Although previous spectral subtraction was needed in some cases, all the smudged were linked to their corresponding lipsticks even when they are smeared on the interfering surfaces. As a consequence, confocal Raman microscopy using the 780 nm excitation laser is presented as a nondestructive powerful tool for the identification of these tricky samples. Copyright © 2014 Elsevier B.V. All rights reserved.

  14. Confocal Raman mapping of collagen cross-link and crystallinity of human dentin-enamel junction.

    Science.gov (United States)

    Slimani, Amel; Nouioua, Fares; Desoutter, Alban; Levallois, Bernard; Cuisinier, Frédéric J G; Tassery, Hervé; Terrer, Elodie; Salehi, Hamideh

    2017-08-01

    The separation zone between enamel and dentin [dentin-enamel junction (DEJ)] with different properties in biomechanical composition has an important role in preventing crack propagation from enamel to dentin. The understanding of the chemical structure (inorganic and organic components), physical properties, and chemical composition of the human DEJ could benefit biomimetic materials in dentistry. Spatial distribution of calcium phosphate crystallinity and the collagen crosslinks near DEJ were studied using confocal Raman microscopy and calculated by different methods. To obtain collagen crosslinking, the ratio of two peaks 1660  cm-1 over 1690  cm-1 (amide I bands) is calculated. For crystallinity, the inverse full-width at half maximum of phosphate peak at 960  cm-1, and the ratio of two Raman peaks of phosphate at 960/950  cm-1 is provided. In conclusion, the study of chemical and physical properties of DEJ provides many benefits in the biomaterial field to improve the synthesis of dental materials in respect to the natural properties of human teeth. Confocal Raman microscopy as a powerful tool provides the molecular structure to identify the changes along DEJ and can be expanded for other mineralized tissues. (2017) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE).

  15. Effect of Cefazolin Treatment on the Nonresonant Raman Signatures of the Metabolic State of Individual Escherichia coli Cells

    NARCIS (Netherlands)

    Moritz, T.; Taylor, D.; Polage, C.; Krol, D.M.; Lane, S.; Chan, J.

    2010-01-01

    Laser tweezers Raman spectroscopy (LTRS) was used to characterize the Raman fingerprints of the metabolic states of Escherichia coli (E. coli) cells and to determine the spectral changes associated with cellular response to the antibiotic Cefazolin. The Raman spectra of E. coli cells sampled at diff

  16. In Situ Confocal Raman Mapping Study of a Single Ti-Assisted ZnO Nanowire

    Directory of Open Access Journals (Sweden)

    Gandhi Ashish

    2009-01-01

    Full Text Available Abstract In this work, we succeeded in preparing in-plane zinc oxide nanowires using a Ti-grid assisted by the chemical vapor deposition method. Optical spatial mapping of the Confocal Raman spectra was used to investigate the phonon and geometric properties of a single ZnO nanowire. The local optical results reveal a red shift in the non-polar E 2 high frequency mode and width broadening along the growth direction, reflecting quantum-confinement in the radial direction.

  17. Imaging phospholipid conformational disorder and packing in giant multilamellar liposome by confocal Raman microspectroscopy.

    Science.gov (United States)

    Noothalapati, Hemanth; Iwasaki, Keita; Yoshimoto, Chikako; Yoshikiyo, Keisuke; Nishikawa, Tomoe; Ando, Masahiro; Hamaguchi, Hiro-O; Yamamoto, Tatsuyuki

    2017-12-05

    Liposomes are closed phospholipid bilayer systems that have profound applications in fundamental cell biology, pharmaceutics and medicine. Depending on the composition (pure or mixture of phospholipids, presence of cholesterol) and preparation protocol, intra- and inter-chain molecular interactions vary leading to changes in the quality (order and packing) of liposomes. So far it is not possible to image conformational disorders and packing densities within a liposome in a straightforward manner. In this study, we utilized confocal Raman microspectroscopy to visualize structural disorders and packing efficiency within a giant multilamellar liposome model by focusing mainly on three regions in the vibrational spectrum (CC stretching, CH deformation and CH stretching). We estimated properties such as trans/gauche isomers and lateral packing probability. Interestingly, our Raman imaging studies revealed gel phase rich domains and heterogeneous lateral packing within the giant multilamellar liposome. Copyright © 2017 Elsevier B.V. All rights reserved.

  18. Identification of different bacterial species in biofilms using confocal Raman microscopy

    Science.gov (United States)

    Beier, Brooke D.; Quivey, Robert G.; Berger, Andrew J.

    2010-11-01

    Confocal Raman microspectroscopy is used to discriminate between different species of bacteria grown in biofilms. Tests are performed using two bacterial species, Streptococcus sanguinis and Streptococcus mutans, which are major components of oral plaque and of particular interest due to their association with healthy and cariogenic plaque, respectively. Dehydrated biofilms of these species are studied as a simplified model of dental plaque. A prediction model based on principal component analysis and logistic regression is calibrated using pure biofilms of each species and validated on pure biofilms grown months later, achieving 96% accuracy in prospective classification. When biofilms of the two species are partially mixed together, Raman-based identifications are achieved within ~2 μm of the boundaries between species with 97% accuracy. This combination of spatial resolution and predication accuracy should be suitable for forming images of species distributions within intact two-species biofilms.

  19. Applicability of confocal Raman microscopy for the signal detective of organic reagents in a PDMS microfluidic chip

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Seung Yeol; Choo, Jae Bum; Ahn, Yoo Min; Kim, Yang S. [Hanyang University, Ansan (Korea, Republic of)

    2002-07-01

    A PDMS microfluidic chip has been constructed using a photolithographic fabrication technique. Confocal laser-induced Raman microscopy has been utilized for the signal detection of chemical species in a PDMS microfluidic chip. The CC1{sub 4} benzene binary mixtures with different % concentrations have been prepared and injected into the PDMS chip using a microsyringe pump. Raman spectra were measured by focusing the Ar{sup +} laser on a microfluidic channel using a 10x objective lens. The concentration of each solvent mixture has been determined from the ratio of Raman intensity profiles, which were measured by integrating the area of characteristic Raman peaks for CC1{sub 4} and benzene. In this work, the feasibility of confocal laser-induced Raman microscopy for the quantitative analysis of organic reagents in a PDMS microfluidic chip will be demonstrated.

  20. Rapid detection of Listeria monocytogenes in milk using confocal micro-Raman spectroscopy and chemometric analysis.

    Science.gov (United States)

    Wang, Junping; Xie, Xinfang; Feng, Jinsong; Chen, Jessica C; Du, Xin-jun; Luo, Jiangzhao; Lu, Xiaonan; Wang, Shuo

    2015-07-02

    Listeria monocytogenes is a facultatively anaerobic, Gram-positive, rod-shape foodborne bacterium causing invasive infection, listeriosis, in susceptible populations. Rapid and high-throughput detection of this pathogen in dairy products is critical as milk and other dairy products have been implicated as food vehicles in several outbreaks. Here we evaluated confocal micro-Raman spectroscopy (785 nm laser) coupled with chemometric analysis to distinguish six closely related Listeria species, including L. monocytogenes, in both liquid media and milk. Raman spectra of different Listeria species and other bacteria (i.e., Staphylococcus aureus, Salmonella enterica and Escherichia coli) were collected to create two independent databases for detection in media and milk, respectively. Unsupervised chemometric models including principal component analysis and hierarchical cluster analysis were applied to differentiate L. monocytogenes from Listeria and other bacteria. To further evaluate the performance and reliability of unsupervised chemometric analyses, supervised chemometrics were performed, including two discriminant analyses (DA) and soft independent modeling of class analogies (SIMCA). By analyzing Raman spectra via two DA-based chemometric models, average identification accuracies of 97.78% and 98.33% for L. monocytogenes in media, and 95.28% and 96.11% in milk were obtained, respectively. SIMCA analysis also resulted in satisfied average classification accuracies (over 93% in both media and milk). This Raman spectroscopic-based detection of L. monocytogenes in media and milk can be finished within a few hours and requires no extensive sample preparation. Copyright © 2015 Elsevier B.V. All rights reserved.

  1. Imaging of Scleral Collagen Deformation Using Combined Confocal Raman Microspectroscopy and Polarized Light Microscopy Techniques.

    Science.gov (United States)

    Chakraborty, Nilay; Wang, Mian; Solocinski, Jason; Kim, Wonsuk; Argento, Alan

    2016-01-01

    This work presents an optospectroscopic characterization technique for soft tissue microstructure using site-matched confocal Raman microspectroscopy and polarized light microscopy. Using the technique, the microstructure of soft tissue samples is directly observed by polarized light microscopy during loading while spatially correlated spectroscopic information is extracted from the same plane, verifying the orientation and arrangement of the collagen fibers. Results show the response and orientation of the collagen fiber arrangement in its native state as well as during tensile and compressive loadings in a porcine sclera model. An example is also given showing how the data can be used with a finite element program to estimate the strain in individual collagen fibers. The measurements demonstrate features that indicate microstructural reorganization and damage of the sclera's collagen fiber arrangement under loading. The site-matched confocal Raman microspectroscopic characterization of the tissue provides a qualitative measure to relate the change in fibrillar arrangement with possible chemical damage to the collagen microstructure. Tests and analyses presented here can potentially be used to determine the stress-strain behavior, and fiber reorganization of the collagen microstructure in soft tissue during viscoelastic response.

  2. Quantification of whey in fluid milk using confocal Raman microscopy and artificial neural network.

    Science.gov (United States)

    Alves da Rocha, Roney; Paiva, Igor Moura; Anjos, Virgílio; Furtado, Marco Antônio Moreira; Bell, Maria José Valenzuela

    2015-06-01

    In this work, we assessed the use of confocal Raman microscopy and artificial neural network as a practical method to assess and quantify adulteration of fluid milk by addition of whey. Milk samples with added whey (from 0 to 100%) were prepared, simulating different levels of fraudulent adulteration. All analyses were carried out by direct inspection at the light microscope after depositing drops from each sample on a microscope slide and drying them at room temperature. No pre- or posttreatment (e.g., sample preparation or spectral correction) was required in the analyses. Quantitative determination of adulteration was performed through a feed-forward artificial neural network (ANN). Different ANN configurations were evaluated based on their coefficient of determination (R2) and root mean square error values, which were criteria for selecting the best predictor model. In the selected model, we observed that data from both training and validation subsets presented R2>99.99%, indicating that the combination of confocal Raman microscopy and ANN is a rapid, simple, and efficient method to quantify milk adulteration by whey. Because sample preparation and postprocessing of spectra were not required, the method has potential applications in health surveillance and food quality monitoring.

  3. Confocal Raman microspectroscopy: measuring the effects of topical moisturizers on stratum corneum water gradient in vivo

    Science.gov (United States)

    Sieg, Anke; Crowther, Jonathan; Blenkiron, Peter; Marcott, Curtis; Matts, Paul J.

    2006-02-01

    The stratum corneum (SC) water concentration gradient is fundamental to skin's role as a barrier, regulating its physical and biochemical properties. Standard instruments utilizing changes in SC electrical properties to estimate SC water concentration provide simple, rapid measurements but cannot provide true interval data as a function of depth. Confocal Raman spectroscopy (CRS) of human subjects provides non-invasive, real-time, in vivo measures of molecular concentration profiles. A state-of-the-art confocal Raman microspectrometer equipped with a fiber-coupled laser source operating at a wavelength of 671 nm was used to obtain measurements in the high wavenumber region (~2400-4000 cm -1). An aircooled, high-sensitivity back-illuminated, deep-depletion CCD camera captured radiation scattered inelastically from focal planes within the skin in vivo (a high-precision, computer-controlled piezo-electric stage and objective allowing depth resolutions of niacinamide on SC water concentration gradient, as measured by CRS, in vivo. The approach to compare SC water gradient effects will be discussed and the utility of this exciting new method will be compared and contrasted to existing methodology.

  4. Waterproofing in Arabidopsis: Following phenolics and lipids in situ by Confocal Raman Microscopy

    Directory of Open Access Journals (Sweden)

    Batirtze ePrats Mateu

    2016-02-01

    Full Text Available Waterproofing of the aerial organs of plants imposed a big evolutionary step during the colonization of the terrestrial environment. The main plant polymers responsible of water repelling are lipids and lignin, which play also important roles in the protection against biotic/abiotic stresses, regulation of flux of gases and solutes and mechanical stability against negative pressure, among others. While the lipids, non-polymerized cuticular waxes together with the polymerized cutin, protect the outer surface, lignin is confined to the secondary cell wall within mechanical important tissues. In the present work a micro cross-section of the stem of Arabidopsis thaliana was used to track in situ the distribution of these non-carbohydrate polymers by Confocal Raman Microscopy. Raman hyperspectral imaging gives a molecular fingerprint of the native waterproofing tissues and cells with diffraction limited spatial resolution (~300 nm at relatively high speed and without any tedious sample preparation. Lipids and lignified tissues as well as their effect on water content was directly visualized by integrating the 1299 cm-1, 1600 cm-1 and 3400 cm-1 band, respectively. For detailed insights into compositional changes of these polymers vertex component analysis was performed on selected sample positions. Changes have been elucidated in the composition of lignin within the lignified tissues and between interfascicular fibers and xylem vessels. Hydrophobising changes were revealed from the epidermal layer to the cuticle as well as a change in the aromatic composition within the cuticle of trichomes. To verify Raman signatures of different waterproofing polymers additionally Raman spectra of the cuticle and cutin monomer from tomato (Solanum lycopersicum as well as aromatic model polymers (milled wood lignin and dehydrogenation polymer of coniferyl alcohol and phenolic acids were acquired. Keywords: Arabidopsis thaliana, lignin, cutin, wax, Raman

  5. Waterproofing in Arabidopsis: Following phenolics and lipids in situ by Confocal Raman Microscopy

    Science.gov (United States)

    Prats Mateu, Batirtze; Hauser, Marie-Theres; Heredia, Antonio; Gierlinger, Notburga

    2016-02-01

    Waterproofing of the aerial organs of plants imposed a big evolutionary step during the colonization of the terrestrial environment. The main plant polymers responsible of water repelling are lipids and lignin, which play also important roles in the protection against biotic/abiotic stresses, regulation of flux of gases and solutes and mechanical stability against negative pressure, among others. While the lipids, non-polymerized cuticular waxes together with the polymerized cutin, protect the outer surface, lignin is confined to the secondary cell wall within mechanical important tissues. In the present work a micro cross-section of the stem of Arabidopsis thaliana was used to track in situ the distribution of these non-carbohydrate polymers by Confocal Raman Microscopy. Raman hyperspectral imaging gives a molecular fingerprint of the native waterproofing tissues and cells with diffraction limited spatial resolution (~300 nm) at relatively high speed and without any tedious sample preparation. Lipids and lignified tissues as well as their effect on water content was directly visualized by integrating the 1299 cm-1, 1600 cm-1 and 3400 cm-1 band, respectively. For detailed insights into compositional changes of these polymers vertex component analysis was performed on selected sample positions. Changes have been elucidated in the composition of lignin within the lignified tissues and between interfascicular fibers and xylem vessels. Hydrophobising changes were revealed from the epidermal layer to the cuticle as well as a change in the aromatic composition within the cuticle of trichomes. To verify Raman signatures of different waterproofing polymers additionally Raman spectra of the cuticle and cutin monomer from tomato (Solanum lycopersicum) as well as aromatic model polymers (milled wood lignin and dehydrogenation polymer of coniferyl alcohol) and phenolic acids were acquired. Keywords: Arabidopsis thaliana, lignin, cutin, wax, Raman, cuticle, waterproofing

  6. Confocal Raman Microscopy of Hybrid-Supported Phospholipid Bilayers within Individual C18-Functionalized Chromatographic Particles.

    Science.gov (United States)

    Kitt, Jay P; Harris, Joel M

    2016-09-01

    Measuring lipid-membrane partitioning of small molecules is critical to predicting bioavailability and investigating molecule-membrane interactions. A stable model membrane for such studies has been developed through assembly of a phospholipid monolayer on n-alkane-modified surfaces. These hybrid bilayers have recently been generated within n-alkyl-chain (C18)-modified porous silica and used in chromatographic retention studies of small molecules. Despite their successful application, determining the structure of hybrid bilayers within chromatographic silica is challenging because they reside at buried interfaces within the porous structure. In this work, we employ confocal Raman microscopy to investigate the formation and temperature-dependent structure of hybrid-phospholipid bilayers in C18-modified, porous-silica chromatographic particles. Porous silica provides sufficient surface area within a confocal probe volume centered in an individual particle to readily measure, with Raman microscopy, the formation of an ordered hybrid bilayer of 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC) with the surface C18 chains. The DMPC surface density was quantified from the relative Raman scattering intensities of C18 and phospholipid acyl chains and found to be ∼40% of a DMPC vesicle membrane. By monitoring Raman spectra acquired versus temperature, the bilayer main phase transition was observed to be broadened and shifted to higher temperature compared to a DMPC vesicle, in agreement with differential scanning calorimetry (DSC) results. Raman scattering of deuterated phospholipid was resolved from protonated C18 chain scattering, showing that the lipid acyl and C18 chains melt simultaneously in a single phase transition. The surface density of lipid in the hybrid bilayer, the ordering of both C18 and lipid acyl chains upon bilayer formation, and decoupling of C18 methylene C-H vibrations by deuterated lipid acyl chains all suggest an interdigitated acyl chain

  7. Differentiating gastrointestinal stromal tumors from gastric adenocarcinomas and normal mucosae using confocal Raman microspectroscopy

    Science.gov (United States)

    Hsu, Chih-Wei; Huang, Chia-Chi; Sheu, Jeng-Horng; Lin, Chia-Wen; Lin, Lien-Fu; Jin, Jong-Shiaw; Chen, Wenlung

    2016-07-01

    Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal neoplasms of the gastrointestinal tract, and gastric adenocarcinomas are a common cancer worldwide. To differentiate GISTs from adenocarcinomas is important because the surgical processes for both are different; the former excises the tumor with negative margins, while the latter requires radical gastrectomy with lymph node dissection. Endoscopy with biopsy is used to distinguish GISTs from adenocarcinomas; however, it may cause tumor bleeding in GISTs. We reported here the confocal Raman microspectroscopy as an effective tool to differentiate GISTs, adenocarcinomas, and normal mucosae. Of 119 patients enrolled in this study, 102 patients underwent gastrectomy (40 GISTs and 62 adenocarcinomas), and 17 patients with benign lesions were obtained as normal mucosae. Raman signals were integrated for 100 s for each spot on the specimen, and 5 to 10 spots, depending on the sample size, were chosen for each specimen. There were significant differences among those tissues as evidenced by different Raman signal responding to phospholipids and protein structures. The spectral data were further processed and analyzed by using principal component analysis. A two-dimensional plot demonstrated that GISTs, adenocarcinomas, and normal gastric mucosae could be effectively differentiated from each other.

  8. Single Cell Confocal Raman Spectroscopy of Human Osteoarthritic Chondrocytes: A Preliminary Study

    Directory of Open Access Journals (Sweden)

    Rajesh Kumar

    2015-04-01

    Full Text Available A great deal of effort has been focused on exploring the underlying molecular mechanism of osteoarthritis (OA especially at the cellular level. We report a confocal Raman spectroscopic investigation on human osteoarthritic chondrocytes. The objective of this investigation is to identify molecular features and the stage of OA based on the spectral signatures corresponding to bio-molecular changes at the cellular level in chondrocytes. In this study, we isolated chondrocytes from human osteoarthritic cartilage and acquired Raman spectra from single cells. Major spectral differences between the cells obtained from different International Cartilage Repair Society (ICRS grades of osteoarthritic cartilage were identified. During progression of OA, a decrease in protein content and an increase in cell death were observed from the vibrational spectra. Principal component analysis and subsequent cross-validation was able to associate osteoarthritic chondrocytes to ICRS Grade I, II and III with specificity 100.0%, 98.1%, and 90.7% respectively, while, sensitivity was 98.6%, 82.8%, and 97.5% respectively. The overall predictive efficiency was 92.2%. Our pilot study encourages further use of Raman spectroscopy as a noninvasive and label free technique for revealing molecular features associated with osteoarthritic chondrocytes.

  9. Confocal Raman spectroscopy of island nuclei formed at the initial stage of quartz glass crystallization

    Science.gov (United States)

    Pankin, D. V.; Zolotarev, V. M.; Colas, M.; Cornette, J.; Evdokimova, M. G.

    2016-12-01

    Island nuclei formed on a polished quartz-glass surface upon heating to 1100°C have been investigated by confocal Raman spectroscopy. The structural and chemical composition of islands is shown to be a central nucleus, a shell around the nucleus, and a thin peripheral ring closing this shell. The formation and growth of individual regions of an island nucleus are found to occur in several stages. The shell around the nucleus is mainly formed by α-SiO2 and α-cristobalite nanoparticles with a size ≥40 nm, whereas the α-SiO2 nanoparticles in the nucleus and peripheral ring are 2-15 nm in size.

  10. Evaluation of human serum of severe rheumatoid arthritis by confocal Raman spectroscopy

    Science.gov (United States)

    Carvalho, C. S.; Raniero, L.; Santo, A. M. E.; Pinheiro, M. M.; Andrade, L. E. C.; Cardoso, M. A. G.; Junior, J. S.; Martin, A. A.

    2010-02-01

    Rheumatoid Arthritis is a systemic chronic inflammatory disease, recurrent and systemic, initiated by autoantibodies and maintained by inflammatory mechanisms cellular applicants. The evaluation of this disease to promote early diagnosis, need an associations of many tools, such as clinical, physical examination and thorough medical history. However, there is no satisfactory consensus due to its complexity. In the present work, confocal Raman spectroscopy was used to evaluate the biochemical composition of human serum of 40 volunteers, 24 patients with rheumatoid arthritis presenting clinical signs and symptoms, and 16 healthy donors. The technique of latex agglutination for the polystyrene covered with human immunoglobulin G and PCR (protein c-reactive) was performed for confirmation of possible false-negative results within the groups, facilitating the statistical interpretation and validation of the technique. This study aimed to verify the changes for the characteristics Raman peaks of biomolecules such as immunoglobulins amides and protein. The results were highly significant with a good separation between groups mentioned. The discriminant analysis was performed through the principal components and correctly identified 92% of the donors. Based on these results, we observed the behavior of arthritis autoimmune, evident in certain spectral regions that characterize the serological differences between the groups.

  11. Confocal Raman study of aging process in diabetes mellitus human voluntaries

    Science.gov (United States)

    Pereira, Liliane; Téllez Soto, Claudio Alberto; dos Santos, Laurita; Ali, Syed Mohammed; Fávero, Priscila Pereira; Martin, Airton A.

    2015-06-01

    Accumulation of AGEs [Advanced Glycation End - products] occurs slowly during the human aging process. However, its formation is accelerated in the presence of diabetes mellitus. In this paper, we perform a noninvasive analysis of glycation effect on human skin by in vivo confocal Raman spectroscopy. This technique uses a laser of 785 nm as excitation source and, by the inelastic scattering of light, it is possible to obtain information about the biochemical composition of the skin. Our aim in this work was to characterize the aging process resulting from the glycation process in a group of 10 Health Elderly Women (HEW) and 10 Diabetic Elderly Women (DEW). The Raman data were collected from the dermis at a depth of 70-130 microns. Through the theory of functional density (DFT) the bands positions of hydroxyproline, proline and AGEs (pentosidine and glucosepane) were calculated by using Gaussian 0.9 software. A molecular interpretation of changes in type I collagen was performed by the changes in the vibrational modes of the proline (P) and hydroxyproline (HP). The data analysis shows that the aging effects caused by glycation of proteins degrades type I collagen differently and leads to accelerated aging process.

  12. Confocal Raman microscopy supported by optical clearing treatment of the skin—influence on collagen hydration

    Science.gov (United States)

    Sdobnov, Anton Yu; Tuchin, Valery V.; Lademann, Juergen; E Darvin, Maxim

    2017-07-01

    Confocal Raman microscopy (CRM) is employed to study the skin physiology, drug permeation and skin disease monitoring. In order to increase the depth of investigations, the effect of optical clearing was observed on porcine ear skin ex vivo. The optical clearing agents (OCAs) glycerol and iohexol (Omnipaque™) were applied to the porcine ear skin and investigated by CRM after 30 and 60 min of treatment. The extent of optical clearing by utilizing concentrations of 70% glycerol and 100% Omnipaque™ was evaluated. The intensity of the skin-related Raman peaks significantly increased starting from the depth 160 µm for Omnipaque™ and 40 µm for glycerol (p  ⩽  0.05) after 60 min of treatment. The OCAs’ influence on the collagen hydration in the deep-located dermis was investigated. Both OCAs induce skin dehydration, but the effect of glycerol treatment (30 min and 60 min) is stronger. The obtained results demonstrate that with increasing the treatment time, both glycerol and Omnipaque™ solutions improve the optical clearing of porcine skin making the deep-located dermal regions able for investigations. At the used concentrations and time intervals, glycerol is more effective than Omnipaque™. However, Omnipaque™ is more promising than glycerol for future in vivo applications as it is an already approved pharmaceutic substance without any known impact on the skin structure.

  13. Optical pathology study of human abdominal aorta tissues using confocal micro resonance Raman spectroscopy

    Science.gov (United States)

    Liu, Cheng-hui; Boydston-White, Susie; Wang, Wubao; Sordillo, Laura A.; Shi, Lingyan; Weisberg, Arel; Tomaselli, Vincent P.; Sordillo, Peter P.; Alfano, Robert R.

    2016-03-01

    Resonance Raman (RR) spectroscopic technique has a high potential for label-free and in-situ detection of biomedical lesions in vivo. This study evaluates the ability of RR spectroscopy method as an optical histopathology tool to detect the atherosclerotic plaque states of abdominal aorta in vitro. This part demonstrates the RR spectral molecular fingerprint features from different sites of the atherosclerotic abdominal aortic wall tissues. Total 57 sites of five pieces aortic samples in intimal and adventitial wall from an autopsy specimen were examined using confocal micro Raman system of WITec 300R with excitation wavelength of 532nm. The preliminary RR spectral biomarkers of molecular fingerprints indicated that typical calcified atherosclerotic plaque (RR peak at 964cm-1) tissue; fibrolipid plaque (RR peaks at 1007, 1161, 1517 and 2888cm-1) tissue, lipid pool with the fatty precipitation cholesterol) with collagen type I (RR peaks at 864, 1452, 1658, 2888 and 2948cm-1) in the soft tissue were observed and investigated.

  14. Depth-profiling by confocal Raman microscopy (CRM): data correction by numerical techniques.

    Science.gov (United States)

    Tomba, J Pablo; Eliçabe, Guillermo E; Miguel, María de la Paz; Perez, Claudio J

    2011-03-01

    The data obtained in confocal Raman microscopy (CRM) depth profiling experiments with dry optics are subjected to significant distortions, including an artificial compression of the depth scale, due to the combined influence of diffraction, refraction, and instrumental effects that operate on the measurement. This work explores the use of (1) regularized deconvolution and (2) the application of simple rescaling of the depth scale as methodologies to obtain an improved, more precise, confocal response. The deconvolution scheme is based on a simple predictive model for depth resolution and the use of regularization techniques to minimize the dramatic oscillations in the recovered response typical of problem inversion. That scheme is first evaluated using computer simulations on situations that reproduce smooth and sharp sample transitions between two materials and finally it is applied to correct genuine experimental data, obtained in this case from a sharp transition (planar interface) between two polymeric materials. It is shown that the methodology recovers very well most of the lost profile features in all the analyzed situations. The use of simple rescaling appears to be only useful for correcting smooth transitions, particularly those extended over distances larger than those spanned by the operative depth resolution, which limits the strategy to the study of profiles near the sample surface. However, through computer simulations, it is shown that the use of water immersion objectives may help to reduce optical distortions and to expand the application window of this simple methodology, which could be useful, for instance, to safely monitor Fickean sorption/desorption of penetrants in polymer films/coatings in a nearly noninvasive way.

  15. Preliminary study of differentiating smears from cancerous and non-cancerous nasopharyngeal tissue using confocal Raman spectroscopy.

    Science.gov (United States)

    Sun, Liqing; Xu, Zhihong; Huang, Wei; Wu, Shanshan; Lin, Xinheng; Zhu, Fengyu; Liu, Nengrong; Huang, Meizhen; Chen, Rong; Zeng, Haishan

    2016-04-01

    Current practice for diagnosing nasopharyngeal carcinoma (NPC) is based on invasive tissue biopsy. This study aims to explore the feasibility of using Raman spectroscopy to differentiate cancerous and non-cancerous nasopharyngeal tissue smears, expecting to realize minimal invasive diagnosis using smears from in vivo mucosa tissue by Raman spectroscopy. Biopsy tissue smears were acquired from 74 patients with pathologically diagnosed nasopharyngeal diseases and measured using confocal Raman spectroscopy. Both fingerprint region and high wavenumber Raman spectra were acquired with distinguish features. Multivariate statistical analysis was used to differentiate cancerous and non-cancerous groups, achieving a diagnostic sensitivity of 87.2 and specificity of 85.7 % for differentiating NPC from nasopharyngeal non-cancerous smears. This work indicates that the method has a unique advantage in microanalysis for tissue smears which may provide a promising minimal invasive (or noninvasive) diagnosing tool for cancer diagnosis.

  16. Confocal Raman spectroscopy: In vivo measurement of physiological skin parameters - A pilot study.

    Science.gov (United States)

    Binder, Lisa; SheikhRezaei, Safoura; Baierl, Andreas; Gruber, Lukas; Wolzt, Michael; Valenta, Claudia

    2017-08-10

    In vivo application of confocal Raman spectroscopy (CRS) allows non-invasive depth measurement of the skin. Thereby obtained knowledge of the skin composition is essential to reliably assess the actual skin state. Besides other components, the skin cholesterol concentration is of interest; however, little is known about its connection to the cholesterol concentration quantified in venous blood. In this study, the skin composition of the volar forearm was characterised in vivo using CRS. In particular, the potential of CRS as a non-invasive method to determine cholesterol levels was validated. Raman spectra of the volar forearm of 15 participants were recorded twice within two weeks. Depth concentration profiles for major skin components were generated. Stratum corneum (SC) thickness was calculated from water concentration profiles. In order to examine the usability of dermal CRS for cholesterol level determination, results were compared to fasting total cholesterol values in venous blood as determined by an enzymatic method. Depth concentration profiles for the skin components of interest showed a comparable curve progression for the participants. It was possible to link changes in concentration to physiological processes. Moreover, age-related differences could be found. Several novel mathematical approaches for the comparison of the skin cholesterol content and the blood cholesterol concentration have been developed. However, no correlation passed the Bonferroni multiple testing correction. CRS serves as useful tool for the in vivo monitoring of skin components and hydration. Concentration depth profiles provide information about the current skin condition. No distinct correlation between the skin and blood cholesterol concentration was found within the scope of the present study. Concerning this matter, the heterogeneous distribution of cholesterol in the skin may be a factor influencing these results. Copyright © 2017 Japanese Society for Investigative

  17. Nanostructured transdermal hormone replacement therapy for relieving menopausal symptoms: a confocal Raman spectroscopy study

    Directory of Open Access Journals (Sweden)

    Marco Antonio Botelho

    2014-02-01

    Full Text Available OBJECTIVE: To determine the safety and efficacy of a transdermal nanostructured formulation of progesterone (10% combined with estriol (0.1% + estradiol (0.25% for relieving postmenopausal symptoms. METHODS: A total of 66 postmenopausal Brazilian women with climacteric symptoms of natural menopause received transdermal nanostructured formulations of progesterone and estrogens in the forearm daily for 60 months to mimic the normal ovarian secretory pattern. Confocal Raman spectroscopy of hormones in skin layers was performed. Clinical parameters, serum concentrations of estradiol and follicle-stimulating hormone, blood pressure, BI-RADS classification from bilateral mammography, and symptomatic relief were compared between baseline and 60 months post-treatment. Clinicaltrials.gov: NCT02033512. RESULTS: An improvement in climacteric symptoms was reported in 92.5% of women evaluated before and after 60 months of treatment. The serum concentrations of estradiol and follicle-stimulating hormone changed significantly (p<0.05 after treatment; the values of serum follicle-stimulating hormone decreased after 60 months from 82.04±4.9 to 57.12±4.1 IU/mL. A bilateral mammography assessment of the breasts revealed normal results in all women. No adverse health-related events were attributed to this hormone replacement therapy protocol. CONCLUSION: The nanostructured formulation is safe and effective in re-establishing optimal serum levels of estradiol and follicle-stimulating hormone and relieving the symptoms of menopause. This transdermal hormone replacement therapy may alleviate climacteric symptoms in postmenopausal women.

  18. Nanostructured transdermal hormone replacement therapy for relieving menopausal symptoms: a confocal Raman spectroscopy study

    Energy Technology Data Exchange (ETDEWEB)

    Botelho, Marco Antonio; Queiroz, Dinalva Brito; Barros, Gisele; Guerreiro, Stela; Umbelino, Sonia; Lyra, Arao; Borges, Boniek; Freitas, Allan, E-mail: marcobotelho@pq.cnpq.br [Universidade Potiguar, Natal, RN (Brazil). Lab. de Nanotecnologia; Fechine, Pierre [Universidade Federal do Ceara (GQMAT/UFCE), Fortaleza, CE (Brazil). Dept. de Quimica Analitica. Grupo Avancado de Biomateriais em Quimica; Queiroz, Danilo Caldas de [Instituto Federal de Ciencia e Tecnologia (IFCT), Fortaleza, CE (Brazil). Lab. de Biotecnologia; Ruela, Ronaldo [Instituto de Biotecnologia Aplicada (INBIOS), Fortaleza, CE (Brazil); Almeida, Jackson Guedes [Universidade Federal do Vale de Sao Francisco (UNIVALE), Petrolina, PE (Brazil). Fac. de Ciencias Farmaceuticas; Quintans Junior, Lucindo [Universidade Federal de Sergipe (UFSE), Sao Cristovao, SE (Brazil). Dept. de Fisiologia

    2014-06-01

    Objective:to determine the safety and efficacy of a transdermal nanostructured formulation of progesterone (10%) combined with estriol (0.1%) + estradiol (0.25%) for relieving postmenopausal symptoms. Methods: a total of 66 postmenopausal Brazilian women with climacteric symptoms of natural menopause received transdermal nanostructured formulations of progesterone and estrogens in the forearm daily for 60 months to mimic the normal ovarian secretory pattern. Confocal Raman spectroscopy of hormones in skin layers was performed. Clinical parameters, serum concentrations of estradiol and follicle-stimulating hormone, blood pressure, BI-RADS classification from bilateral mammography, and symptomatic relief were compared between baseline and 60 months post-treatment. Clinicaltrials.gov: NCT02033512. Results: an improvement in climacteric symptoms was reported in 92.5% of women evaluated before and after 60 months of treatment. The serum concentrations of estradiol and follicle-stimulating hormone changed significantly (p<0.05) after treatment; the values of serum follicle-stimulating hormone decreased after 60 months from 82.04 ± 4.9 to 57.12 ± 4.1 IU/mL. A bilateral mammography assessment of the breasts revealed normal results in all women. No adverse health-related events were attributed to this hormone replacement therapy protocol. Conclusion: the nanostructured formulation is safe and effective in re-establishing optimal serum levels of estradiol and follicle-stimulating hormone and relieving the symptoms of menopause. This transdermal hormone replacement therapy may alleviate climacteric symptoms in postmenopausal women. (author)

  19. Statistical strategies to reveal potential vibrational markers for in vivo analysis by confocal Raman spectroscopy

    Science.gov (United States)

    Oliveira Mendes, Thiago de; Pinto, Liliane Pereira; Santos, Laurita dos; Tippavajhala, Vamshi Krishna; Téllez Soto, Claudio Alberto; Martin, Airton Abrahão

    2016-07-01

    The analysis of biological systems by spectroscopic techniques involves the evaluation of hundreds to thousands of variables. Hence, different statistical approaches are used to elucidate regions that discriminate classes of samples and to propose new vibrational markers for explaining various phenomena like disease monitoring, mechanisms of action of drugs, food, and so on. However, the technical statistics are not always widely discussed in applied sciences. In this context, this work presents a detailed discussion including the various steps necessary for proper statistical analysis. It includes univariate parametric and nonparametric tests, as well as multivariate unsupervised and supervised approaches. The main objective of this study is to promote proper understanding of the application of various statistical tools in these spectroscopic methods used for the analysis of biological samples. The discussion of these methods is performed on a set of in vivo confocal Raman spectra of human skin analysis that aims to identify skin aging markers. In the Appendix, a complete routine of data analysis is executed in a free software that can be used by the scientific community involved in these studies.

  20. A portable confocal hyperspectral microscope without any scan or tube lens and its application in fluorescence and Raman spectral imaging

    Science.gov (United States)

    Li, Jingwei; Cai, Fuhong; Dong, Yongjiang; Zhu, Zhenfeng; Sun, Xianhe; Zhang, Hequn; He, Sailing

    2017-06-01

    In this study, a portable confocal hyperspectral microscope is developed. In traditional confocal laser scanning microscopes, scan lens and tube lens are utilized to achieve a conjugate relationship between the galvanometer and the back focal plane of the objective, in order to achieve a better resolution. However, these lenses make it difficult to scale down the volume of the system. In our portable confocal hyperspectral microscope (PCHM), the objective is placed directly next to the galvomirror. Thus, scan lens and tube lens are not included in our system and the size of this system is greatly reduced. Furthermore, the resolution is also acceptable in many biomedical and food-safety applications. Through reducing the optical length of the system, the signal detection efficiency is enhanced. This is conducive to realizing both the fluorescence and Raman hyperspectral imaging. With a multimode fiber as a pinhole, an improved image contrast is also achieved. Fluorescent spectral images for HeLa cells/fingers and Raman spectral images of kumquat pericarp are present. The spectral resolution and spatial resolutions are about 0.4 nm and 2.19 μm, respectively. These results demonstrate that this portable hyperspectral microscope can be used in in-vivo fluorescence imaging and in situ Raman spectral imaging.

  1. In vivo confocal Raman spectroscopy for intrinsic aging and photoaging assessment.

    Science.gov (United States)

    de Vasconcelos Nasser Caetano, Livia; de Oliveira Mendes, Thiago; Bagatin, Edileia; Amante Miot, Helio; Marques Soares, Juliana Laudiceia; Simoes E Silva Enokihara, Milvia Maria; Abrahao Martin, Airton

    2017-07-19

    In vivo confocal Raman spectroscopy is a non-invasive method to assess either the epidermis or the dermis composition. Few studies have focused on dermis collagen alterations through intrinsic aging and photoaging. This study evaluated the in vivo Raman spectra from the dermis of a photoexposed site versus a non-photoexposed region in different age groups, and evaluated the correlation between peak intensities and age, photoaging score and the amount of collagen assessed with histology and high frequency ultrasound (HFUS). Fifteen volunteers aged 28-82 years were divided into three groups according to forearm photoaging degree. In vivo Raman spectra from the dermis were collected on the dorsal forearm (chronically photoexposed skin) and on the proximal medial arm (non-photoexposed skin). Cross-sectional images of the skin were obtained using a 20MHz ultrasound unit exactly on the same sites, which were further submitted to punch biopsies for histologic study (collagen I immunohistochemistry, picrosirius red staining and Verhoeff). Principal Component Analysis (PCA) and Orthogonal Partial Least Squares Discriminant Analysis (OPLS-DA) were taken in the spectral region of 796cm(-1)-996cm(-1) to determine its potential to discriminate between different groups. The Spearman rank correlation coefficient of individual peak intensities and ratios with age, clinical score and the amount of collagen assessed by ultrasound and histology were calculated. PCA of pairs of groups and OPLS-DA could discriminate the intrinsically from the photoaged skin and the young group from the elderly one, with important contribution of the 938cm(-1) and 855cm(-1) peaks intensities. The intensity of the peaks in 855cm(-1) and/or 938cm(-1) presented moderate correlation with age (rho=0.579, p=0.049) and moderate to high inverse correlation with HFUS echogenicity (rho=-0.710, p=0.010) and collagen I immunohistochemistry (rho=-0.833, p=0.005) in the non-photoexposed region. The I1275/I1450

  2. Confocal Raman spectroscopic analysis of cross-linked ultra-high molecular weight polyethylene for application in artificial hip joints.

    Science.gov (United States)

    Pezzotti, Giuseppe; Kumakura, Tsuyoshi; Yamada, Kiyotaka; Tateiwa, Toshiyuki; Puppulin, Leonardo; Zhu, Wenliang; Yamamoto, Kengo

    2007-01-01

    Confocal spectroscopic techniques are applied to selected Raman bands to study the microscopic features of acetabular cups made of ultra-high molecular weight polyethylene (UHMWPE) before and after implantation in vivo. The micrometric lateral resolution of a laser beam focused on the polymeric surface (or subsurface) enables a highly resolved visualization of 2-D conformational population patterns, including crystalline, amorphous, orthorhombic phase fractions, and oxidation index. An optimized confocal probe configuration, aided by a computational deconvolution of the optical probe, allows minimization of the probe size along the in-depth direction and a nondestructive evaluation of microstructural properties along the material subsurface. Computational deconvolution is also attempted, based on an experimental assessment of the probe response function of the polyethylene Raman spectrum, according to a defocusing technique. A statistical set of high-resolution microstructural data are collected on a fully 3-D level on gamma-ray irradiated UHMWPE acetabular cups both as-received from the maker and after retrieval from a human body. Microstructural properties reveal significant gradients along the immediate material subsurface and distinct differences are found due to the loading history in vivo, which cannot be revealed by conventional optical spectroscopy. The applicability of the confocal spectroscopic technique is valid beyond the particular retrieval cases examined in this study, and can be easily extended to evaluate in-vitro tested components or to quality control of new polyethylene brands. Confocal Raman spectroscopy may also contribute to rationalize the complex effects of gamma-ray irradiation on the surface of medical grade UHMWPE for total joint replacement and, ultimately, to predict their actual lifetime in vivo.

  3. Spatially resolved confocal resonant Raman microscopic analysis of anode-grown Geobacter sulfurreducens biofilms.

    Science.gov (United States)

    Lebedev, Nikolai; Strycharz-Glaven, Sarah M; Tender, Leonard M

    2014-02-03

    When grown on the surface of an anode electrode, Geobacter sulfurreducens forms a multi-cell thick biofilm in which all cells appear to couple the oxidation of acetate with electron transport to the anode, which serves as the terminal metabolic electron acceptor. Just how electrons are transported through such a biofilm from cells to the underlying anode surface over distances that can exceed 20 microns remains unresolved. Current evidence suggests it may occur by electron hopping through a proposed network of redox cofactors composed of immobile outer membrane and/or extracellular multi-heme c-type cytochromes. In the present work, we perform a spatially resolved confocal resonant Raman (CRR) microscopic analysis to investigate anode-grown Geobacter biofilms. The results confirm the presence of an intra-biofilm redox gradient whereby the probability that a heme is in the reduced state increases with increasing distance from the anode surface. Such a gradient is required to drive electron transport toward the anode surface by electron hopping via cytochromes. The results also indicate that at open circuit, when electrons are expected to accumulate in redox cofactors involved in electron transport due to the inability of the anode to accept electrons, nearly all c-type cytochrome hemes detected in the biofilm are oxidized. The same outcome occurs when a comparable potential to that measured at open circuit (-0.30 V vs. SHE) is applied to the anode, whereas nearly all hemes are reduced when an exceedingly negative potential (-0.50 V vs. SHE) is applied to the anode. These results suggest that nearly all c-type cytochrome hemes detected in the biofilm can be electrochemically accessed by the electrode, but most have oxidation potentials too negative to transport electrons originating from acetate metabolism. The results also reveal a lateral heterogeneity (x-y dimensions) in the type of c-type cytochromes within the biofilm that may affect electron transport to the

  4. Sensitive Skin: Assessment of the Skin Barrier Using Confocal Raman Microspectroscopy.

    Science.gov (United States)

    Richters, Renée J H; Falcone, Denise; Uzunbajakava, Natallia E; Varghese, Babu; Caspers, Peter J; Puppels, Gerwin J; van Erp, Piet E J; van de Kerkhof, Peter C M

    2017-01-01

    Sensitive skin (SS), a frequently reported condition in the Western world, has been suggested to be underlined by an impaired skin barrier. The aim of this study was to investigate the skin barrier molecular composition in SS subjects using confocal Raman microspectroscopy (CRS), and to compare it with that of non-SS (NSS) individuals as well as atopic dermatitis (AD) and allergic rhinoconjunctivitis (AR) subjects, who frequently report SS. Subjects with SS (n = 29), NSS (n = 30), AD (n = 11), and AR (n = 27) were included. Stratum corneum (SC) thickness, water, ceramides/fatty acids, and natural moisturizing factor (NMF) were measured by CRS along with transepidermal water loss and capacitance on the ventral forearm, thenar, and cheek. Sebum levels were additionally measured on the forearm and cheek. No differences between SS and NSS subjects were found regarding SC thickness, water, and NMF content, yet a trend towards lower ceramides/fatty acids was observed in the cheek. Compared to AD subjects, the SS group showed higher ceramides/fatty acid content in the forearm, whereas no differences emerged with AR. The correlation of macroscopic biophysical techniques and CRS was weak, yet CRS confirmed the well-known lower content of NMF and water, and thinner SC in subjects with filaggrin mutations. The skin barrier in SS is not impaired in terms of SC thickness, water, NMF, and ceramides/fatty acid content. The failure of biophysical techniques to follow alterations in the molecular composition of the skin barrier revealed by CRS emphasizes a strong need in sensitive and specific tools for in vivo skin barrier analysis. © 2017 S. Karger AG, Basel.

  5. In Situ Confocal Raman Microscopy of Hydrated Early Stages of Bacterial Biofilm Formation on Various Surfaces in a Flow Cell.

    Science.gov (United States)

    Smith-Palmer, Truis; Lin, Sicheng; Oguejiofor, Ikenna; Leng, Tianyang; Pustam, Amanda; Yang, Jin; Graham, Lori L; Wyeth, Russell C; Bishop, Cory D; DeMont, M Edwin; Pink, David

    2016-02-01

    Bacterial biofilms are precursors to biofouling by other microorganisms. Understanding their initiation may allow us to design better ways to inhibit them, and thus to inhibit subsequent biofouling. In this study, the ability of confocal Raman microscopy to follow the initiation of biofouling by a marine bacterium, Pseudoalteromonas sp. NCIMB 2021 (NCIMB 2021), in a flow cell, using optical and confocal Raman microscopy, was investigated. The base of the flow cell comprised a cover glass. The cell was inoculated and the bacteria attached to, and grew on, the cover glass. Bright field images and Raman spectra were collected directly from the hydrated biofilms over several days. Although macroscopically the laser had no effect on the biofilm, within the first 24 h cells migrated away from the position of the laser beam. In the absence of flow, a buildup of extracellular substances occurred at the base of the biofilm. When different coatings were applied to cover glasses before they were assembled into the flow cells, the growth rate, structure, and composition of the resulting biofilm was affected. In particular, the ratio of Resonance Raman peaks from cytochrome c (CC) in the extracellular polymeric substances, to the Raman phenylalanine (Phe) peak from protein in the bacteria, depended on both the nature of the surface and the age of the biofilm. The ratios were highest for 24 h colonies on a hydrophobic surface. Absorption of a surfactant with an ethyleneoxy chain into the hydrophobic coating created a surface similar to that given with a simple PEG coating, where bacteria grew in colonies away from the surface rather than along the surface, and CC:Phe ratios were initially low but increased at least fivefold in the first 48 h.

  6. Confocal Raman depth-scanning spectroscopic study of phonon-plasmon modes in GaN epilayers

    Science.gov (United States)

    Strelchuk, V. V.; Bryksa, V. P.; Avramenko, K. A.; Valakh, M. Ya.; Belyaev, A. E.; Mazur, Yu. I.; Ware, M. E.; DeCuir, E. A.; Salamo, G. J.

    2011-06-01

    Coupled longitudinal-optical (LO)-phonon-plasmon excitations were studied using confocal micro-Raman spectroscopy. The high-quality Si-doped GaN epilayers were grown in a Gunn diode structure on (0001) sapphire substrates by plasma assisted molecular beam epitaxy. Depth-profiled Raman spectra exhibit a spatial variation of both low, ω-, and high, ω+, frequency coupled phonon-plasmon modes (CPPMs) in the n-GaN layers. To describe the features of the CPPMs in the Raman spectra a self-consistent model that includes both the electro-optic and deformation-potential as well as charge-density fluctuation mechanisms as important processes for light scattering in n-GaN has been proposed. An agreement between the theoretical and experimental line shapes of the Raman spectra is obtained. From the best line-shape fitting of the CPPMs the depth profiles of the plasmon and phonon damping, plasmon frequency, free carrier concentrations, and electron mobility as well as the contributions of the electron-phonon interaction and charge density fluctuations to the Raman cross section in the GaN layers are determined. It is found that these depth profiles exhibit considerable nonuniformity and change at different laser pump-power excitations. Despite the high electron concentration in the n+-GaN layers, a strong peak of the unscreened A1(LO) phonon is also observed. A possible origin for the appearance of this mode is discussed.

  7. Hydrocarbons in phlogopite from Kasenyi kamafugitic rocks (SW Uganda): cross-correlated AFM, confocal microscopy and Raman imaging

    Science.gov (United States)

    Moro, Daniele; Valdrè, Giovanni; Mesto, Ernesto; Scordari, Fernando; Lacalamita, Maria; Ventura, Giancarlo Della; Bellatreccia, Fabio; Scirè, Salvatore; Schingaro, Emanuela

    2017-01-01

    This study presents a cross-correlated surface and near surface investigation of two phlogopite polytypes from Kasenyi kamafugitic rocks (SW Uganda) by means of advanced Atomic Force Microscopy (AFM), confocal microscopy and Raman micro-spectroscopy. AFM revealed comparable nanomorphology and electrostatic surface potential for the two mica polytypes. A widespread presence of nano-protrusions located on the mica flake surface was also observed, with an aspect ratio (maximum height/maximum width) from 0.01 to 0.09. Confocal microscopy showed these features to range from few nm to several μm in dimension, and shapes from perfectly circular to ellipsoidic and strongly elongated. Raman spectra collected across the bubbles showed an intense and convolute absorption in the range 3000–2800 cm‑1, associated with weaker bands at 1655, 1438 and 1297 cm‑1, indicating the presence of fluid inclusions consisting of aliphatic hydrocarbons, alkanes and cycloalkanes, with minor amounts of oxygenated compounds, such as carboxylic acids. High-resolution Raman images provided evidence that these hydrocarbons are confined within the bubbles. This work represents the first direct evidence that phlogopite, a common rock-forming mineral, may be a possible reservoir for hydrocarbons.

  8. Hydrocarbons in phlogopite from Kasenyi kamafugitic rocks (SW Uganda): cross-correlated AFM, confocal microscopy and Raman imaging

    Science.gov (United States)

    Moro, Daniele; Valdrè, Giovanni; Mesto, Ernesto; Scordari, Fernando; Lacalamita, Maria; Ventura, Giancarlo Della; Bellatreccia, Fabio; Scirè, Salvatore; Schingaro, Emanuela

    2017-01-01

    This study presents a cross-correlated surface and near surface investigation of two phlogopite polytypes from Kasenyi kamafugitic rocks (SW Uganda) by means of advanced Atomic Force Microscopy (AFM), confocal microscopy and Raman micro-spectroscopy. AFM revealed comparable nanomorphology and electrostatic surface potential for the two mica polytypes. A widespread presence of nano-protrusions located on the mica flake surface was also observed, with an aspect ratio (maximum height/maximum width) from 0.01 to 0.09. Confocal microscopy showed these features to range from few nm to several μm in dimension, and shapes from perfectly circular to ellipsoidic and strongly elongated. Raman spectra collected across the bubbles showed an intense and convolute absorption in the range 3000–2800 cm−1, associated with weaker bands at 1655, 1438 and 1297 cm−1, indicating the presence of fluid inclusions consisting of aliphatic hydrocarbons, alkanes and cycloalkanes, with minor amounts of oxygenated compounds, such as carboxylic acids. High-resolution Raman images provided evidence that these hydrocarbons are confined within the bubbles. This work represents the first direct evidence that phlogopite, a common rock-forming mineral, may be a possible reservoir for hydrocarbons. PMID:28098185

  9. A method based on coffee-ring deposition confocal Raman spectroscopy of analysis of melamine in milk

    Science.gov (United States)

    Tan, Zong; Chen, Da

    2016-10-01

    In this work, an economical and high-efficiency method for detection of melamine in milk was developed. The enrichment effect of coffee-ring was combined with the micro-region analysis of confocal Raman spectroscopy, in addition, assisted with chemometric algorithmthe. Consequently, a desired result was obtained that the LOD of melamine in this method was 1 ppm, which was excellent because the sensitivity of conventional Raman detection was generally low. Furthermore, the whole process were processed in an easily available condition with almost no chemical reagents consumption, and the chosen substrates for the formation of coffee-ring were reusable. Thus, the method is environmental friendly and has a great potential application in food safety inspection.

  10. Detection of Receptor-Induced Glycoprotein Conformational Changes on Enveloped Virions by Using Confocal Micro-Raman Spectroscopy

    Science.gov (United States)

    Lu, Xiaonan; Liu, Qian; Benavides-Montano, Javier A.; Nicola, Anthony V.; Aston, D. Eric; Rasco, Barbara A.

    2013-01-01

    Conformational changes in the glycoproteins of enveloped viruses are critical for membrane fusion, which enables viral entry into cells and the pathological cell-cell fusion (syncytia) associated with some viral infections. However, technological capabilities for identifying viral glycoproteins and their conformational changes on actual enveloped virus surfaces are generally scarce, challenging, and time-consuming. Our model, Nipah virus (NiV), is a syncytium-forming biosafety level 4 pathogen with a high mortality rate (40 to 75%) in humans. Once the NiV attachment glycoprotein (G) (NiV-G) binds the cell receptor ephrinB2 or -B3, G triggers conformational changes in the fusion glycoprotein (F) that result in membrane fusion and viral entry. We demonstrate that confocal micro-Raman spectroscopy can, within minutes, simultaneously identify specific G and F glycoprotein signals and receptor-induced conformational changes in NiV-F on NiV virus-like particles (VLPs). First, we identified reproducible G- and F-specific Raman spectral features on NiV VLPs containing M (assembly matrix protein), G, and/or F or on NiV/vesicular stomatitis virus (VSV) pseudotyped virions via second-derivative transformations and principal component analysis (PCA). Statistical analyses validated our PCA models. Dynamic temperature-induced conformational changes in F and G or receptor-induced target membrane-dependent conformational changes in F were monitored in NiV pseudovirions in situ in real time by confocal micro-Raman spectroscopy. Advantageously, Raman spectroscopy can identify specific protein signals in relatively impure samples. Thus, this proof-of-principle technological development has implications for the rapid identification and biostability characterization of viruses in medical, veterinary, and food samples and for the analysis of virion glycoprotein conformational changes in situ during viral entry. PMID:23283947

  11. Pressure estimation using the ‘diamond Raman scale’ at low pressures in diamond anvil cell experiments using a highly confocal Raman system

    Science.gov (United States)

    Fujii, Taku; Ohfuji, Hiroaki

    2015-02-01

    Pressure estimation using the frequency shift of the diamond Raman peak from the anvil culet is readily and widely used in diamond anvil cell experiments along with the conventional ruby fluorescence method. Here, we propose a modified diamond Raman scale particularly designed for pressure measurement below ~10 GPa. A series of experiments were conducted using a highly confocal Raman system and H2O, ethanol/methanol mixture and NaCl samples loaded in a rhenium gasket which was pre-indented to 40-60 or 100-110 μm thick. The result showed that the frequency of the diamond Raman peak from the anvil culet increases linearly with pressure between 1 and 13 GPa, when using a sufficiently pre-indented (40-60 μm thick) gasket. The frequency shifts are calibrated against the pressure determined by the ruby fluorescence method, which is an alternative pressure scale. In addition, a preliminary measurement at high temperature up to 575 K suggests the potential application of this method for high temperature experiments.

  12. Non-invasive depth profile imaging of the stratum corneum using confocal Raman microscopy: first insights into the method.

    Science.gov (United States)

    Ashtikar, Mukul; Matthäus, Christian; Schmitt, Michael; Krafft, Christoph; Fahr, Alfred; Popp, Jürgen

    2013-12-18

    The stratum corneum is a strong barrier that must be overcome to achieve successful transdermal delivery of a pharmaceutical agent. Many strategies have been developed to enhance the permeation through this barrier. Traditionally, drug penetration through the stratum corneum is evaluated by employing tape-stripping protocols and measuring the content of the analyte. Although effective, this method cannot provide a detailed information regarding the penetration pathways. To address this issue various microscopic techniques have been employed. Raman microscopy offers the advantage of label free imaging and provides spectral information regarding the chemical integrity of the drug as well as the tissue. In this paper we present a relatively simple method to obtain XZ-Raman profiles of human stratum corneum using confocal Raman microscopy on intact full thickness skin biopsies. The spectral datasets were analysed using a spectral unmixing algorithm. The spectral information obtained, highlights the different components of the tissue and the presence of drug. We present Raman images of untreated skin and diffusion patterns for deuterated water and beta-carotene after Franz-cell diffusion experiment.

  13. Depth-resolved confocal micro-Raman spectroscopy for characterizing GaN-based light emitting diode structures

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Wei-Liang; Lee, Yu-Yang; Chang, Yu-Ming, E-mail: ymchang@ntu.edu.tw [Center for Condensed Matter Sciences, National Taiwan University, 10617 Taipei, Taiwan (China); Chang, Chiao-Yun; Huang, Huei-Min; Lu, Tien-Chang [Department of Photonics, National Chiao Tung University, 30010 Hsinchu, Taiwan (China)

    2013-11-15

    In this work, we demonstrate that depth-resolved confocal micro-Raman spectroscopy can be used to characterize the active layer of GaN-based LEDs. By taking the depth compression effect due to refraction index mismatch into account, the axial profiles of Raman peak intensities from the GaN capping layer toward the sapphire substrate can correctly match the LED structural dimension and allow the identification of unique Raman feature originated from the 0.3 μm thick active layer of the studied LED. The strain variation in different sample depths can also be quantified by measuring the Raman shift of GaN A{sub 1}(LO) and E{sub 2}(high) phonon peaks. The capability of identifying the phonon structure of buried LED active layer and depth-resolving the strain distribution of LED structure makes this technique a potential optical and remote tool for in operando investigation of the electronic and structural properties of nitride-based LEDs.

  14. Sub-micrometer-scale mapping of magnetite crystals and sulfur globules in magnetotactic bacteria using confocal Raman micro-spectrometry.

    Directory of Open Access Journals (Sweden)

    Stephan H K Eder

    Full Text Available The ferrimagnetic mineral magnetite Fe3O4 is biomineralized by magnetotactic microorganisms and a diverse range of animals. Here we demonstrate that confocal Raman microscopy can be used to visualize chains of magnetite crystals in magnetotactic bacteria, even though magnetite is a poor Raman scatterer and in bacteria occurs in typical grain sizes of only 35-120 nm, well below the diffraction-limited optical resolution. When using long integration times together with low laser power (<0.25 mW to prevent laser induced damage of magnetite, we can identify and map magnetite by its characteristic Raman spectrum (303, 535, 665 cm(-1 against a large autofluorescence background in our natural magnetotactic bacteria samples. While greigite (cubic Fe3S4; Raman lines of 253 and 351 cm(-1 is often found in the Deltaproteobacteria class, it is not present in our samples. In intracellular sulfur globules of Candidatus Magnetobacterium bavaricum (Nitrospirae, we identified the sole presence of cyclo-octasulfur (S8: 151, 219, 467 cm(-1, using green (532 nm, red (638 nm and near-infrared excitation (785 nm. The Raman-spectra of phosphorous-rich intracellular accumulations point to orthophosphate in magnetic vibrios and to polyphosphate in magnetic cocci. Under green excitation, the cell envelopes are dominated by the resonant Raman lines of the heme cofactor of the b or c-type cytochrome, which can be used as a strong marker for label-free live-cell imaging of bacterial cytoplasmic membranes, as well as an indicator for the redox state.

  15. Proof-of-concept demonstration of free-form optics enhanced confocal Raman spectroscopy in combination with optofluidic lab-on-chip

    Science.gov (United States)

    Liu, Qing; De Coster, Diane; Loterie, Damien; Van Erps, Jürgen; Vervaeke, Michael; Missinne, Jeroen; Thienpont, Hugo; Ottevaere, Heidi

    2016-07-01

    Raman spectroscopy is a powerful optical and non-destructive technique and a well-known method for analysis purposes, especially to determine the molecular fingerprint of substances. Traditionally, such analyses are done in a specialized lab, with considerable requirements in terms of equipment, time and manual sampling of substances of interest. In this paper we take a step from bulky Raman spectroscopy laboratory analyses towards lab-on-chip (LOC) analyses. We present an optofluidic lab-on-chip for confocal Raman spectroscopy, which can be used for the analysis of liquids. The confocal detection suppresses the unwanted background from the polymer material out of which the chip is fabricated. We design the free-form optical reflector using non-sequential ray-tracing combined with a mathematical code to simulate the Raman scattering behavior of the substance under test. We prototype the device in Polymethyl methacrylate (PMMA) by means of ultraprecision diamond tooling. In a proof-of-concept demonstration, we first show the confocal behavior of our Raman lab-on-chip system by measuring the Raman spectrum of ethanol. In a next step, we compare the Raman spectra measured in our lab-on-chip with spectra measured with a commercial Raman spectrometer. Finally, to calibrate the system we perform Raman measurements on urea solutions with different concentrations. We achieve a detection limit that corresponds to a noise equivalent concentration of 20mM. Apart from strongly reducing the background perturbations, our confocal Raman spectroscopy system has other advantages as well. The reflector design is robust from a mechanical point of view and has the potential for mass-manufacturing using hot embossing or injection molding.

  16. Nanoparticle uptake and their co-localization with cell compartments - a confocal Raman microscopy study at single cell level

    Energy Technology Data Exchange (ETDEWEB)

    Estrela-Lopis, I; Donath, E [Institute of Medical Physics and Biophysics, Leipzig University, Haertelstrasse 16, 04107 Leipzig (Germany); Romero, G; Rojas, E; Moya, S E, E-mail: Irina.Estrela-Lopis@medizin.uni-leipzig.de [CIC biomaGUNE, Paseo Miramon 182 Edificio Empresarial C, 20009 San Sebastian, Gipuzkoa (Spain)

    2011-07-06

    Confocal Raman Microscopy, a non-invasive, non-destructive and label-free technique, was employed to study the uptake and localization of nanoparticles (NPs) in the Hepatocarcinoma human cell line HepG2 at the level of single cells. Cells were exposed to carbon nanotubes (CNTs) the surface of which was engineered with polyelectrolytes and lipid layers, aluminium oxide and cerium dioxide nanoparticles. Raman spectra deconvolution was applied to obtain the spatial distributions of NPs together with lipids/proteins in cells. The colocalization of the NPs with different intracellular environments, lipid bodies, protein and DNA, was inferred. Lipid coated CNTs associated preferentially with lipid rich regions, whereas polyelectrolyte coated CNTs were excluded from lipid rich regions. Al{sub 2}O{sub 3} NPs were found in the cytoplasm. CeO{sub 2} NPs were readily taken up and have been observed all over the cell. Raman z-scans proved the intracellular distribution of the respective NPs.

  17. Confocal Raman spectromicroscopy for tin-core/carbon-shell nanowire heterostructure

    Energy Technology Data Exchange (ETDEWEB)

    Wang Fengping, E-mail: fpwang@ustb.edu.cn [Department of Physics, University of Science and Technology Beijing, Beijing 100083 (China); Li Ruying; Sun Xueliang [Department of Mechanical and Materials Engineering, University of Western Ontario, London, Ontario, N6A 5B9 (Canada); Ding Zhifeng [Department of Chemistry, University of Western Ontario, London, Ontario, N6A 3K7 (Canada)

    2011-10-15

    High density heterostructures of carbon nanotubes encapsulated single crystalline tin nanowires have been characterized by Raman spectromicroscopy. The morphology, composition and structure of the synthesized nanoheterostructures were examined by using scanning electron microscopy, transmission electron microscopy. The Raman spectra obviously manifest the crystalline nano-graphite within amorphous carbon walls in the heterostructures. The Raman image reproduces the pristine heterostructures of the CNTs as seen in SEM image, which illustrate the single nanowires oriented uniformly grown on micro-graphitic fibers. It was found that the resultant heterostructures are luminescent which was attributed to crystalline nano-graphite embedded in the amorphous carbon matrix, which is a consequence of excitons localization within an increasing number of sp{sup 2} rich clusters. The contrast in the Raman image reflects nonuniform distribution of the graphite cluster size which acts as the radiative centers. The luminescent property was reviewed. The enhanced Raman spectra and luminescent property by the well-defined tin nanowires inside the heterostructures was revealed.

  18. Studying DEHP migration in plasticized PVC used for blood bags by coupling Raman confocal microscopy to UV spectroscopy.

    Science.gov (United States)

    Al Salloum, H; Saunier, J; Tfayli, A; Yagoubi, N

    2016-04-01

    Plasticized PVC is widely used to make medical devices such as tubing, perfusion bags and blood bags. By using confocal Raman microscopy on a PVC sheet plasticized with around 40% of di-(2-ethylhexyl)phthalate (DEHP), we propose a simple and sensitive approach to studying and understanding the diffusion of plasticizers from polymers into the surrounding media. Moreover, we sought to correlate our findings to standard measurements conducted by UV spectroscopy. This study showed differences in the concentration gradient observed due to the diffusion of the plasticizer inside a PVC sheet. We can thus follow the critical DEHP ratios that can impact the diffusion process. Water and ethanol were chosen as storage media: in ethanol, the lowest concentration of DEHP was observed at the surface resulting in the formation of a less plasticized layer near the interface; unlike ethanol, PVC sheets stored in water showed a greater concentration of DEHP on the film surface as an exudation of DEHP onto the surface.

  19. Identification of two organic bands showing different chemical composition within the skeleton of Porites lutea: a confocal Raman microscopy study

    Science.gov (United States)

    Wall, M.; Nehrke, G.

    2012-07-01

    Confocal Raman microscopy mapping was used to investigate the organic matrix distribution within the skeleton of the coral Porites lutea. Two types of growth lines could be identified: one corresponds to the well-known incremental growth layers, whereas the second type of growth lines showed an elemental composition that differed from the incremental growth layers. The position and shape of the latter growth lines resemble either denticle finger-like structures (most likely traces of former spines) or former skeletal surfaces. We hypothesize that these lines are involved in the three-dimensional arrangement of skeletal elements and represent the outer skeletal surface before another growth cycle of elongation, infilling and thickening of skeletal components continues. We show that high spatial resolution mapping can significantly improve our understanding of skeletal growth patterns in coral skeletons.

  20. Micro- and nanodomain imaging in uniaxial ferroelectrics: Joint application of optical, confocal Raman, and piezoelectric force microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Shur, V. Ya., E-mail: vladimir.shur@urfu.ru; Zelenovskiy, P. S. [Ferroelectric Laboratory, Institute of Natural Sciences, Ural Federal University, 620000 Ekaterinburg (Russian Federation)

    2014-08-14

    The application of the most effective methods of the domain visualization in model uniaxial ferroelectrics of lithium niobate (LN) and lithium tantalate (LT) family, and relaxor strontium-barium niobate (SBN) have been reviewed in this paper. We have demonstrated the synergetic effect of joint usage of optical, confocal Raman, and piezoelectric force microscopies which provide extracting of the unique information about formation of the micro- and nanodomain structures. The methods have been applied for investigation of various types of domain structures with increasing complexity: (1) periodical domain structure in LN and LT, (2) nanodomain structures in LN, LT, and SBN, (3) nanodomain structures in LN with modified surface layer, (4) dendrite domain structure in LN. The self-assembled appearance of quasi-regular nanodomain structures in highly non-equilibrium switching conditions has been considered.

  1. Geochemical compositions of trona samples by PEDXRF and their identification under confocal Raman spectroscopy: Beypazari-Ankara, Turkey

    Energy Technology Data Exchange (ETDEWEB)

    Ustuendag, Ilknur [Hacettepe University, Faculty of Engineering, Department of Physics Engineering, Ankara (Turkey)]. E-mail: iozkirim@hacettepe.edu.tr; Ustuendag, Zafer [Ankara University, Faculty of Science, Department of Chemistry, Ankara (Turkey); Kalfa, Orhan Murat [Gazi University, Faculty of Art and Science, Department of Chemistry, Ankara (Turkey); Kadioglu, Yusuf Kagan [Ankara University, Faculty of Engineering, Department of Geological Engineering, Ankara (Turkey)

    2007-01-15

    Trona has a wide exposure around Beypazari-Ankara, Turkey. The samples of trona were collected from the investigated area. Two different analyses were used during the analyses of the trona by polarized X-ray fluorescence (PEDXRF). The first method, prepared sample, was multi-element analyzed with standard method. The precession and accuracy of the technique for chemical analysis is demonstrated by analyzing USGS standards, GEOL, GBW-7109 and GBW-7309 Sediment. The second method was used for the determination of the concentration of Al, Fe, Zn, Sn and Ba. Determinations of two methods were compared with the five selected elements. The trona was studied using HR-800 (HORIBA-JobinYvon) confocal Raman for identification of trona.

  2. In vivo comparative documentation of skin hydration by confocal Raman microscopy, SkinSensor, Skicon, and NovaMeter

    Science.gov (United States)

    Zhang, Guojin; Papillon, Aline; Ruvolo, Eduardo, Jr.; Bargo, Paulo R.; Kollias, Nikiforos

    2010-02-01

    The stratum corneum provides a vital physical barrier that protects against external insults and excessive internal water loss. Water activity is thought as a key factor to maintain proper skin barrier integrity via regulating enzyme activities and lipid phase behavior. Consequently, maintenance of an optimal hydration level in SC becomes an important clinical and cosmetic concern. The objective methods to assess SC hydration are based on either electrical or optical measurements. Electrical techniques used in the current study include high frequency conductance (Skicon), impedance (Nova DPM) and DC I-V curve (Skinsensor). Confocal Raman Microscopy was utilized to document water profile versus depth, and this technique is based on inelastic scattering of monochromatic light from different chemical species of skin. Water patches were applied on the 14 subjects' forearm for 20 minutes and 1.5 hrs. Skin hydration levels for individuals were documented by utilizing the mentioned above instruments in vivo. Results show that patterns of water profiles upon the hydration are significantly different among the individuals and these differences may be related to skin barrier function integrity. The intrinsic water content and water absorption upon the hydration were summed corresponding to different depths (3 μm and 15 μm) from the data obtained by confocal Raman microscopy. These results were correlated to the readings from electrical approaches. Superficial (3 μm) but not deeper layer (15 μm) water contents correlated well with the readings from SkinSensor. Neither depth measurements correlate well with the Skicon. There is strong correlation between the data acquired with Skicon and SkinSensor.

  3. Confocal Raman and electronic microscopy studies on the topotactic conversion of calcium carbonate from Pomacea lineate shells into hydroxyapatite bioceramic materials in phosphate media.

    Science.gov (United States)

    dePaula, S M; Huila, M F G; Araki, K; Toma, H E

    2010-12-01

    Conversion of Pomacea lineate shells into hydroxyapatite (HA) bioceramic materials was investigated by their in vitro treatment with phosphate solutions, at room temperature. Confocal Raman microscopy revealed that the conversion proceeds at distinct rates through the nacreous or periostracum sides of the shell. The conversion can be accelerated using powdered samples, yielding biocompatible materials of great interest in biomedicine.

  4. Spatially Resolved Characterization of Cellulose Nanocrystal-Polypropylene Composite by Confocal Raman Microscopy

    Science.gov (United States)

    Umesh P. Agarwal; Ronald Sabo; Richard S. Reiner; Craig M. Clemons; Alan W. Rudie

    2012-01-01

    Raman spectroscopy was used to analyze cellulose nanocrystal (CNC)–polypropylene (PP) composites and to investigate the spatial distribution of CNCs in extruded composite filaments. Three composites were made from two forms of nanocellulose (CNCs from wood pulp and the nanoscale fraction of microcrystalline cellulose) and two of the three composites investigated used...

  5. Chapter 1.4: Spatially Resolved Characterization of CNC-Polypropylene composite by Confocal Raman Microscopy

    Science.gov (United States)

    Umesh Agarwal; Ronald Sabo; Richard Reiner; Craig Clemons; Alan Rudie

    2013-01-01

    Raman spectroscopy was used to analyze cellulose nanocrystal (CNC)-polypropylene (PP) composites and to investigate the spatial distribution of CNCs in extruded composite filaments. Three composites were made from two forms of nanocellulose (CNCs from wood pulp and the nanoscale fraction of microcrystalline cellulose), and two of the three composites...

  6. Confocal Raman spectroscopy: In vivo biochemical changes in the human skin by topical formulations under UV radiation.

    Science.gov (United States)

    Tosato, M G; Orallo, D E; Ali, S M; Churio, M S; Martin, A A; Dicelio, L

    2015-12-01

    A new approach to the study of the effects on human skin of mycosporine-like amino acids (MAAs) and gadusol (Gad) incorporated in polymer gel is proposed in this work. The depth profile and photoprotector effects of Pluronic F127® gels containing each of the natural actives were evaluated by in vivo confocal Raman spectroscopy aiming at the analysis of the biochemical changes on human skin. Hierarchical cluster analysis (HCA) showed that the data corresponding to different depths of the skin, from surface to 4 μm, and from 6 to 16 μm, remained in the same cluster. In vivo Raman spectra, classified into five different layers of epidermis according to their similarities, indicated that the amount of Gad gel increased by about 26% in the outermost layer of the stratum corneum (SC) and that MAAs gel at 2 μm depth was 103.4% higher than in the outermost layer of the SC. Variations in the SC of urocanic acid at 1490-1515 cm(-1) and 1652 cm(-1) and histidine at 1318 cm(-1) were calculated, before and after UV exposure with or without gels. With the application of gels the vibrational modes that correspond to lipids in trans conformation (1063 and 1128 cm(-1)) increased with respect to normal skin, whereas gauche conformation (1085 cm(-1)) disappeared. Our studies suggest that gels protected the skin against the stress of the natural defense mechanism caused by high levels of UV exposure.

  7. Study of the vitamins A, E and C esters penetration into the skin by confocal Raman spectroscopy in vivo

    Science.gov (United States)

    Mogilevych, Borys; Isensee, Debora; Rangel, Joao L.; Dal Pizzol, Carine; Martinello, Valeska C. A.; Dieamant, Gustavo C.; Martin, Airton A.

    2015-06-01

    Vitamins A, E and C play important role in skin homeostasis and protection. Hence, they are extensively used in many cosmetic and cosmeceutic products. However, their molecules are unstable, and do not easily penetrate into the skin, which drastically decreases its efficiency in topical formulations. Liposoluble derivative of the vitamin A - retinyl palmitate, vitamin E - tocopheryl acetate, and vitamin C - tetraisopalmitoyl ascorbic acid, are more stable, and are frequently used as an active ingredient in cosmetic products. Moreover, increased hydrophobicity of these molecules could lead to a higher skin penetration. The aim of this work is to track and compare the absorption of the liposoluble derivatives of the vitamins and their encapsulated form, into the healthy human skin in vivo. We used Confocal Raman Spectroscopy (CRS) that is proven to be helpful in label-free non-destructive investigation of the biochemical composition and molecular conformational analysis of the biological samples. The measurements were performed in the volar forearm of the 10 healthy volunteers. Skin was treated with both products, and Raman spectra were obtained after 15 min, 3 hours, and 6 hours after applying the formulation. 3510 Skin Composition Analyzer (River Diagnostics, The Netherlands) with 785 nm laser excitation was used to acquire information in the fingerprint region. Significant difference in permeation of the products was observed. Whereas only free form of retinyl palmitate penetrate the skin within first 15 minutes, all three vitamin derivatives were present under the skin surface in case of nanoparticulated form.

  8. Confocal Raman depth-profile analysis of the electrical and structural properties in III-nitride structures

    Energy Technology Data Exchange (ETDEWEB)

    Strelchuk, V.V.; Bryksa, V.P.; Avramenko, K.A.; Valakh, M.Ya.; Belyaev, A.E. [V. Lashkaryov Institute of Semiconductor Physics, National Academy of Sciences of Ukraine, 45 Nauky pr., 03028 Kyiv (Ukraine); Mazur, Yu.I.; Ware, M.E.; DeCuir, E.A. Jr.; Salamo, G.J. [Department of Physics, University of Arkansas, Fayetteville, Arkansas 72701 (United States)

    2011-07-15

    Scanning confocal Raman spectroscopy was used to non-destructively evaluate the structural and electronic properties of n{sup +}/n{sub 0}/n{sup +}-GaN Gunn-diode structures. The depth profiles of the free carrier concentration and mobility were obtained from a line shape analysis of the {omega}{sup -}, {omega}{sup +} coupled phonon-plasmon modes. It was found that the intensity profiles of the Raman polar A{sub 1}(LO) phonon mode depend on the thickness of the undoped n{sub 0} layer, while the intensity profiles of the nonpolar E{sub 2}{sup high} mode were unaffected by the doping. The change in frequency and linewidth of E{sub 2}{sup high} mode throughout the thickness of the GaN layers, however reveal structural inhomogeneity in the diode structures. The carrier concentration and mobility exhibit only slight variations with thickness with the largest variation being at the free surface of the device. (copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  9. In situ quantification of β-carotene partitioning in oil-in-water emulsions by confocal Raman microscopy.

    Science.gov (United States)

    Wan Mohamad, W A Fahmi; Buckow, Roman; Augustin, MaryAnn; McNaughton, Don

    2017-10-15

    Confocal Raman microscopy (CRM) was able to quantify the β-carotene concentration in oil droplets and determine the partitioning characteristics of β-carotene within the emulsion system in situ. The results were validated by a conventional method involving solvent extraction of β-carotene separately from the total emulsion as well as the aqueous phase separated by centrifugation, and quantification by absorption spectrophotometry. CRM also enabled the localization of β-carotene in an emulsion. From the Raman image, the β-carotene partitioning between the aqueous and oil phases of palm olein-in-water emulsions stabilized by whey protein isolate (WPI) was observed. Increasing the concentration of β-carotene in an emulsion (from 0.1 to 0.3g/kg emulsion) with a fixed gross composition (10% palm olein:2% WPI) decreased the concentration of β-carotene in the oil droplet. CRM is a powerful tool for in situ analyses of components in heterogeneous systems such as emulsions. Copyright © 2017 Elsevier Ltd. All rights reserved.

  10. Synthesis of a deuterated probe for the confocal Raman microscopy imaging of squalenoyl nanomedicines

    Science.gov (United States)

    Buchy, Eric; Vukosavljevic, Branko; Windbergs, Maike; Sobot, Dunja; Dejean, Camille; Mura, Simona; Couvreur, Patrick

    2016-01-01

    Summary The synthesis of ω-di-(trideuteromethyl)-trisnorsqualenic acid has been achieved from natural squalene. The synthesis features the use of a Shapiro reaction of acetone-d 6 trisylhydrazone as a key step to implement the terminal isopropylidene-d 6 moiety. The obtained squalenic acid-d 6 has been coupled to gemcitabine to provide the deuterated analogue of squalenoyl gemcitabine, a powerful anticancer agent endowed with self-assembling properties. The Raman spectra of both deuterated and non-deuterated squalenoyl gemcitabine nanoparticles displayed significant Raman scattering signals. They revealed no differences except from the deuterium peak patterns in the silent spectral region of cells. This paves the way for label-free intracellular trafficking studies of squalenoyl nanomedicines. PMID:27559365

  11. Depth profiling of APTES self-assembled monolayers using surface-enhanced confocal Raman microspectroscopy

    Science.gov (United States)

    Sun, Yingying; Yanagisawa, Masahiro; Kunimoto, Masahiro; Nakamura, Masatoshi; Homma, Takayuki

    2017-09-01

    The internal structure of self-assembled monolayers (SAMs) such as 3-aminopropyltriethoxysilane (APTES) fabricated on a glass substrate is difficult to characterize and analyze at nanometer level. In this study, we employed surface-enhanced Raman spectroscopy (SERS) to study the internal molecular structure of APTES SAMs. The sample APTES SAMs were deposited with Ag nanoparticles to enhance the Raman signal and to obtain subtler structure information, which were supported by density functional theory calculations. In addition, in order to carry out high-resolution analysis, especially for vertical direction, a fine piezo electric positioner was used to control the depth scanning with a step of 0.1 nm. We measured and distinguished the vertical Raman intensity variations of specific groups in APTES, such as Ag/NH2, CH2, and Sisbnd O, with high resolution. The interfacial bond at the two interfaces of Ag-APTES and APTES-SiO2 was identified. Moreover, APTES molecule orientation was demonstrated to be inhomogeneous from frequency shift.

  12. Spatially resolved characterization of cellulose nanocrystal-polypropylene composite by confocal Raman microscopy.

    Science.gov (United States)

    Agarwal, Umesh P; Sabo, Ronald; Reiner, Richard S; Clemons, Craig M; Rudie, Alan W

    2012-07-01

    Raman spectroscopy was used to analyze cellulose nanocrystal (CNC) -polypropylene (PP) composites and to investigate the spatial distribution of CNCs in extruded composite filaments. Three composites were made from two forms of nanocellulose (CNCs from wood pulp and the nano-scale fraction of microcrystalline cellulose) and two of the three composites investigated used maleated PP as a coupling agent. Raman maps, based on cellulose and PP bands at 1098 and 1460 cm(-1), respectively, obtained at 1 μm spatial resolution showed that the CNCs were aggregated to various degrees in the PP matrix. Of the three composites analyzed, two showed clear existence of phase-separated regions: Raman images with strong PP and absent/weak cellulose or vice versa. For the third composite, the situation was slightly improved but a clear transition interface between the PP-abundant and CNC-abundant regions was observed, indicating that the CNC remained poorly dispersed. The spectroscopic approach to investigating spatial distribution of the composite components was helpful in evaluating CNC dispersion in the composite at the microscopic level, which helped explain the relatively modest reinforcement of PP by the CNCs.

  13. STRUCTURAL AND MECHANICAL CHARACTERIZATION OF DEFORMED POLYMER USING CONFOCAL RAMAN MICROSCOPY AND DSC

    Directory of Open Access Journals (Sweden)

    Birgit Neitzel

    2016-02-01

    Full Text Available Polymers have various interesting properties, which depend largely on their inner structure. One way to influence the macroscopic behaviour is the deformation of the polymer chains, which effects the change in microstructure. For analyzing the microstructure of non-deformed and deformed polymer materials, Raman spectroscopy as well as differential scanning calorimetry (DSC were used. In the present study we compare the results for crystallinity measurements of deformed polymers using both methods in order to characterize the differences in micro-structure due to deformation. The study is ongoing, and we present the results of the first tests.

  14. Confocal Raman imaging study showing macrophage mediated biodegradation of graphene in vivo.

    Science.gov (United States)

    Girish, Chundayil Madathil; Sasidharan, Abhilash; Gowd, G Siddaramana; Nair, Shantikumar; Koyakutty, Manzoor

    2013-11-01

    This study is focused on the crucial issue of biodegradability of graphene under in vivo conditions. Characteristic Raman signatures of graphene are used to three dimensionally (3D) image its localization in lung, liver, kidney and spleen of mouse and identified gradual development of structural disorder, happening over a period of 3 months, as indicated by the formation of defect-related D'band, line broadening of D and G bands, increase in ID /IG ratio and overall intensity reduction. Prior to injection, the carboxyl functionalized graphene of lateral size ∼200 nm is well dispersed in aqueous medium, but 24 hours post injection, larger aggregates of size up to 10 μm are detected in various organs. Using Raman cluster imaging method, temporal development of disorder is detected from day 8 onwards, which begins from the edges and grows inwards over a period of 3 months. The biodegradation is found prominent in graphene phagocytosed by tissue-bound macrophages and the gene expression studies of pro-inflammatory cytokines indicated the possibility of phagocytic immune response. In addition, in vitro studies conducted on macrophage cell lines also show development of structural disorder in the engulfed graphene, reiterating the role of macrophages in biodegradation. This is the first report providing clear evidence of in vivo biodegradation of graphene and these results may radically change the perspective on potential biomedical applications of graphene.

  15. Bacterial and abiotic decay in waterlogged archaeological Picea abies (L.) Karst studied by confocal Raman imaging and ATR-FTIR spectroscopy

    DEFF Research Database (Denmark)

    Pedersen, Nanna Bjerregaard; Gierlinger, Notburga; Thygesen, Lisbeth Garbrecht

    2015-01-01

    contained regions with intensities lower than sound S2 layers up to intensity values as high as the compound middle lamella (CML). CRI revealed strong depletion of carbohydrates in RM which indicated that EB are able to utilise the carbohydrate fraction of the cell wall effectively. Raman bands assigned......Waterlogged archaeological Norway spruce [Picea abies (L.) Karst] poles were studied by means of confocal Raman imaging (CRI) and attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR) analysis to determine lignin and polysaccharide composition and distribution in the cell...

  16. Depth profiling of strain and carrier concentration by cleaved surface scanning of GaN Gunn-diode: confocal Raman microscopy

    Science.gov (United States)

    Belyaev, A. E.; Strelchuk, V. V.; Nikolenko, A. S.; Romanyuk, A. S.; Mazur, Yu I.; Ware, M. E.; DeCuir, E. A., Jr.; Salamo, G. J.

    2013-10-01

    Confocal micro-Raman spectroscopy was applied to study the cleaved surface of vertical GaN Gunn-diode structure grown by molecular-beam epitaxy. The analysis of lateral scanning along the cleaved edge reveals the depth profile of elastic strain, quality of the crystal structure, and the concentration of charge carriers. Results are compared with that of axial confocal Raman depth profiling normal to the structure's surface. Decrease of compressive strain near the cleaved edge in the direction from the substrate to the structure's surface and in the growth plane towards the cleaved edge is shown. The decrease in charge carrier concentration in the undoped n0-GaN channel region in comparison with the n+-GaN contact region is identified. Peculiarities of the resulting spatial profiles of free charge carriers and their correlation with the initial doping profile are discussed.

  17. Reconstructing skeletal fiber arrangement and growth mode in the coral Porites lutea (Cnidaria, Scleractinia: a confocal Raman microscopy study

    Directory of Open Access Journals (Sweden)

    G. Nehrke

    2012-11-01

    Full Text Available Confocal Raman microscopy (CRM mapping was used to investigate the microstructural arrangement and organic matrix distribution within the skeleton of the coral Porites lutea. Relative changes in the crystallographic orientation of crystals within the fibrous fan-system could be mapped, without the need to prepare thin sections, as required if this information is obtained by polarized light microscopy. Simultaneously, incremental growth lines can be visualized without the necessity of etching and hence alteration of sample surface. Using these methods two types of growth lines could be identified: one corresponds to the well-known incremental growth layers, whereas the second type of growth lines resemble denticle finger-like structures (most likely traces of former spines or skeletal surfaces. We hypothesize that these lines represent the outer skeletal surface before another growth cycle of elongation, infilling and thickening of skeletal areas continues. We show that CRM mapping with high spatial resolution can significantly improve our understanding of the micro-structural arrangement and growth patterns in coral skeletons.

  18. In Situ Analysis of a Silver Nanoparticle-Precipitating Shewanella Biofilm by Surface Enhanced Confocal Raman Microscopy.

    Directory of Open Access Journals (Sweden)

    Gal Schkolnik

    Full Text Available Shewanella oneidensis MR-1 is an electroactive bacterium, capable of reducing extracellular insoluble electron acceptors, making it important for both nutrient cycling in nature and microbial electrochemical technologies, such as microbial fuel cells and microbial electrosynthesis. When allowed to anaerobically colonize an Ag/AgCl solid interface, S. oneidensis has precipitated silver nanoparticles (AgNp, thus providing the means for a surface enhanced confocal Raman microscopy (SECRaM investigation of its biofilm. The result is the in-situ chemical mapping of the biofilm as it developed over time, where the distribution of cytochromes, reduced and oxidized flavins, polysaccharides and phosphate in the undisturbed biofilm is monitored. Utilizing AgNp bio-produced by the bacteria colonizing the Ag/AgCl interface, we could perform SECRaM while avoiding the use of a patterned or roughened support or the introduction of noble metal salts and reducing agents. This new method will allow a spatially and temporally resolved chemical investigation not only of Shewanella biofilms at an insoluble electron acceptor, but also of other noble metal nanoparticle-precipitating bacteria in laboratory cultures or in complex microbial communities in their natural habitats.

  19. Reconstructing skeletal fiber arrangement and growth mode in the coral Porites lutea (Cnidaria, Scleractinia): a confocal Raman microscopy study

    Science.gov (United States)

    Wall, M.; Nehrke, G.

    2012-11-01

    Confocal Raman microscopy (CRM) mapping was used to investigate the microstructural arrangement and organic matrix distribution within the skeleton of the coral Porites lutea. Relative changes in the crystallographic orientation of crystals within the fibrous fan-system could be mapped, without the need to prepare thin sections, as required if this information is obtained by polarized light microscopy. Simultaneously, incremental growth lines can be visualized without the necessity of etching and hence alteration of sample surface. Using these methods two types of growth lines could be identified: one corresponds to the well-known incremental growth layers, whereas the second type of growth lines resemble denticle finger-like structures (most likely traces of former spines or skeletal surfaces). We hypothesize that these lines represent the outer skeletal surface before another growth cycle of elongation, infilling and thickening of skeletal areas continues. We show that CRM mapping with high spatial resolution can significantly improve our understanding of the micro-structural arrangement and growth patterns in coral skeletons.

  20. Age related depth profiles of human Stratum Corneum barrier-related molecular parameters by confocal Raman microscopy in vivo.

    Science.gov (United States)

    Choe, ChunSik; Schleusener, Johannes; Lademann, Jürgen; Darvin, Maxim E

    2017-08-24

    In this study, stratum corneum (SC) depth profiles of hydrogen bound water molecule types, intercellular lipid (ICL) ordering, concentration of natural moisturizing factor (NMF) and keratin folding/unfolding properties are investigated in vivo for older (mean 50 years old) and younger (mean 29 years old) human skin using confocal Raman microscopy. The results show that the SC of the older group is modestly thicker (p <0.1), has more hydrogen bound water molecules at the depth 20-30% of the SC thickness (p <0.05), has a higher ordered organization of ICL (p <0.1) and higher concentration of NMF (p <0.05) at the depth 20-40% of the SC thickness compared to the younger group. This study also reveals, that the hydrogen bonding state of water highly correlates with NMF and the lateral structure of ICL but not with keratin's folding/unfolding properties. The presented results let suggest, that the decreased trans-epidermal water loss (TEWL) with increasing age cannot be sufficiently explained by only the increased SC thickness, but additionally by the increase of ICL ordering, higher NMF concentration and thus larger amount of hydrogen bound water molecules at the depth 20-40% of the SC thickness. Copyright © 2017 Elsevier B.V. All rights reserved.

  1. Non-destructive method for strain imaging in an individual GaN nanorod by confocal Raman technique

    Science.gov (United States)

    Nagarajan, S.; Sopanen, M.

    2016-11-01

    GaN based layer structures on highly lattice mismatched substrates are widely used for electronic and optoelectronic devices. Top down etched, GaN based nanorod structures are mainly studied due to their more effective strain relaxation. The previous measurements on the strain state of these structures have been performed either on single detached nanorods or on ensembles of nanorods still on the substrate. Here we demonstrate a technique based on confocal Raman scattering spectroscopy to probe the strain state of a single GaN nanorod still on the original substrate non-destructively. Both lateral and depth resolved imaging is achieved close to the diffraction limit of light. We observe that a GaN nanorod on the substrate is compressively strained throughout. The strain decreases from the base of the nanorod towards the top surface, but the top surface is still compressively strained. The detached GaN nanorod is less compressively strained overall, and the strain relaxes from the center towards all the edges.

  2. Further understanding of the adsorption mechanism of N719 sensitizer on anatase TiO2 films for DSSC applications using vibrational spectroscopy and confocal Raman imaging.

    Science.gov (United States)

    Lee, Kee Eun; Gomez, Mario A; Elouatik, Samir; Demopoulos, George P

    2010-06-15

    Vibrational spectroscopic studies of N719 dye-adsorbed TiO(2) films have been carried out by using SERRS, ATR-FTIR, and confocal Raman imaging. The high wavenumber region (3000-4000 cm(-1)) of dye adsorbed TiO(2) is analyzed via Raman and IR spectroscopy to investigate the role of surface hydroxyl groups in the anchoring mode. As a complementary technique, confocal Raman imaging is employed to study the distribution features of key dye groups (COO-, bipyridine, and C=O) on the anatase surface. Sensitized TiO(2) films made from two different nanocrystalline anatase powders are investigated: a commercial one (Dyesol) and our synthetic variety produced through aqueous synthesis. It is proposed the binding of the N719 dye to TiO(2) to occur through two neighboring carboxylic acid/carboxylate groups via a combination of bidentate-bridging and H-bonding involving a donating group from the N719 (and/or Ti-OH) units and acceptor from the Ti-OH (and/or N719) groups. The Raman imaging distribution of COO(-)(sym) on TiO(2) was used to show the covalent bonding, while the distribution of C=O mode was applied to observe the electrostatically bonded groups.

  3. Confocal Raman microscopic characterization of the molecular species responsible for the grain cohesion of Triticum aestivum wheat: effect of chemical treatment

    Science.gov (United States)

    Piot, Olivier; Saadi, Abdelbasset; Autran, Jean-Claude; Manfait, Michel

    1999-04-01

    Raman microspectroscopy is a very well appropriate technique for the characterization of the molecules responsible of the wheat grain cohesion, since it is non-destructive and can be readily applied in-situ. The cohesion of the kernel or starchy endosperm depends on a protein content located at the interstices of starch granules. The separation between the kernel and the envelope depends on the composition of the aleurone cells layer, in phenolic acids and pentosans. Confocal Raman microscopy has been performed on kernel sections of various Triticum aestivum samples. Raman spectra recorded at different parts of such sections are very specific, such as spectra of the starchy endosperm protein. The technique has been also used to study the effect of chemical treatment on the binding of the constituents of the aleurone cells walls. In addition, certain marker bands of starch and proteins have been used to construct spectral images.

  4. Lipid distribution, composition and uptake in bovine articular cartilage studied using Raman micro-spectrometry and confocal microscopy.

    Science.gov (United States)

    Mansfield, Jessica Claire; Winlove, C Peter

    2017-07-01

    The distribution and composition of endogenous lipids in articular cartilage and transport of exogenous fatty acids have been investigated on a microscopic scale in fresh bovine articular cartilage. To investigate the distribution and composition of the endogenous lipids, hyperspectral Raman maps were taken of chondrocytes and their surrounding matrix in both the deep and superficial zones. These revealed differences in both lipid distribution and composition between the two zones. Extracellular lipid was observed surrounding the cells in the superficial zone but not in the deep zone. Additionally, intracellular lipid droplets were observed that were larger and more numerous in the deep zone (P = 0.01). The extracellular lipid was primarily free saturated fatty acid, whereas the cellular lipid droplets contained triglycerides with unsaturated fatty acid chains. Fatty acid uptake and transport were investigated by incubating cartilage samples in Dulbecco's modified Eagle's medium containing fluorescently labelled palmitate for a range of times and temperatures. After incubation, the palmitate distribution was imaged using confocal microscopy. Palmitate accumulated preferentially in the territorial matrix only in the superficial zone where the concentration was up to 100-fold greater than that in the bulk matrix (P = 0.001). Palmitate uptake by the chondrocytes in both zones showed differential temperature sensitivity (P = 0.05), which would support the idea that cells take up palmitate by both active and passive mechanisms. The study reveals large differences between chondrocytes in the superficial and deep zones in their lipid content, in their extracellular lipid environment and in their access to exogenous fatty acids. © 2017 The Authors. Journal of Anatomy published by John Wiley & Sons Ltd on behalf of Anatomical Society.

  5. Confocal Raman microspectrometry: a vectorial electromagnetic treatment of the light focused and collected through a planar interface and its application to the study of a thin coating.

    Science.gov (United States)

    Sourisseau, C; Maraval, P

    2003-11-01

    In-depth confocal Raman microspectrometry (CRM) studies through a planar interface between materials of mismatched refraction indices are known to be affected by a decrease of both the collected Raman intensity and the axial resolution as a function of the penetration depth. Following a previous model, which takes the refraction, diffraction, and spherical aberration effects into account when focusing a Gaussian incident laser beam with a high numerical aperture objective lens, a complete vectorial treatment of these phenomena is considered. It is demonstrated that off-axis refraction effects cannot be neglected and that the dimension of the confocal pinhole aperture plays a crucial role on the effective focal plane position and on the collection efficiency. We thus propose a more rigorous and complete approach to the problem, and we find a very good agreement between experimental and theoretical Raman intensity variations for a thick polyethylene sample as a function of the penetration depth. As compared with calculations where only refraction was considered, we confirm that the lengthening of the focus even for a large penetration depth is significantly reduced upon diffraction effects. As an illustrative example, the theoretical Raman responses for a thin coating of approximately 20 microns on a polymer substrate were investigated and compared to experimental results already published. Even though the interfacial region is spread over approximately 5-6 microns when using a 100x objective and a confocal pinhole of 200 microns diameter, it is definitively concluded that the apparent axial resolution is not drastically deteriorated with increasing depth and that the coating thickness may be directly estimated with a precision of approximately 1.0 micron (5%).

  6. In vivo/ex vivo targeting of Langerhans cells after topical application of the immune response modifier TMX-202: confocal Raman microscopy and histology analysis

    Science.gov (United States)

    Darvin, Maxim E.; Thiede, Gisela; Ascencio, Saul Mujica; Schanzer, Sabine; Richter, Heike; Vinzón, Sabrina E.; Hasche, Daniel; Rösl, Frank; May, Roberto; Hazot, Yohan; Tamarkin, Dov; Lademann, Juergen

    2016-05-01

    The increased ability of TMX-202 (derivative of imiquimod) to penetrate the intact stratum corneum (SC) and the follicular orifices of porcine ear skin was shown ex vivo using confocal Raman microscopy and laser scanning microscopy. Moreover, to assess whether TMX-202 is able to reach the immune cells, Langerhans cells extracted from pretreated human skin were investigated ex vivo using confocal Raman microscopy combined with multivariate statistical methods. Tracking the Raman peak of dimethyl sulfoxide centered at 690 cm-1, the absorption of TMX-202 containing formulation by Langerhans cells was shown. To answer the question whether the TMX-202 active ingredient is able to reach Langerhans cells, the attraction of immune cells to TMX-202 containing formulation treated skin was measured in the in vivo rodent model Mastomys coucha. The results show that TMX-202 active ingredient is able to reach Langerhans cells after penetrating through the intact skin and subsequently attract immune cells. Both the intercellular/transcellular as well as the follicular pathways allow the penetration through the intact barrier of the SC.

  7. Single-cell analysis of the methanogenic archaeon Methanosarcina soligelidi from Siberian permafrost by means of confocal Raman microspectrocopy for astrobiological research

    Science.gov (United States)

    Serrano, Paloma; Wagner, Dirk; Böttger, Ute; de Vera, Jean-Pierre; Lasch, Peter; Hermelink, Antje

    2014-08-01

    Methanogenic archaea from Siberian permafrost are suitable model organisms that meet many of the preconditions for survival on the martian subsurface. These microorganisms have proven to be highly resistant when exposed to diverse stress factors such as desiccation, radiation and other thermo-physical martian conditions. In addition, the metabolic requirements of methanogenic archaea are in principle compatible with the environmental conditions of the Red Planet. The ExoMars mission will deploy a rover carrying a Raman spectrometer among the analytical instruments in order to search for signatures of life and to investigate the martian geochemistry. Raman spectroscopy is known as a powerful nondestructive optical technique for biosignature detection that requires only little sample preparation. In this study, we describe the use of confocal Raman microspectroscopy (CRM) as a rapid and sensitive technique for characterization of the methanogenic archaeon Methanosarcina soligelidi SMA-21 at the single cell level. These studies involved acquisition of Raman spectra from individual cells isolated from microbial cultures at different stages of growth. Spectral analyses indicated a high degree of heterogeneity between cells of individual cultures and also demonstrated the existence of growth-phase specific Raman patterns. For example, besides common Raman patterns of microbial cells, CRM additionally revealed the presence of lipid vesicles and CaCO3 particles in microbial preparations of M. soligelidi SMA-21, a finding that could be confirmed by electron microscopy. The results of this study suggest that heterogeneity and diversity of microorganisms have to be considered when using Raman-based technologies in future space exploration missions.

  8. Influence of curvature strain and Van der Waals force on the inter-layer vibration mode of WS2 nanotubes: A confocal micro-Raman spectroscopic study

    Science.gov (United States)

    Wang, Xiao Hu; Zheng, Chang Cheng; Ning, Ji Qiang

    2016-09-01

    Transition-metal dichalcogenides (TMDs) nanostructures including nanotubes and monolayers have attracted great interests in materials science, chemistry to condensed matter physics. We present an interesting study of the vibration modes in multi-walled tungsten sulfide (WS2) nanotubes prepared via sulfurizing tungsten oxide (WO3) nanowires which are investigated by confocal micro-Raman spectroscopy. The inter-layer vibration mode of WS2 nanotubes, A1g, is found to be sensitive to the diameter and curvature strain, while the in-plane vibration mode, E12g, is not. A1g mode frequency shows a redshift by 2.5 cm-1 for the multi-layered nanotubes with small outer-diameters, which is an outcome of the competition between the Van der Waals force stiffening and the curvature strain softening. We also show that the Raman peak intensity ratio is significantly different between the 1-2 wall layered nanotubes and monolayer flat sheets.

  9. Use of portable devices and confocal Raman spectrometers at different wavelength to obtain the spectral information of the main organic components in tomato (Solanum lycopersicum) fruits

    Science.gov (United States)

    Trebolazabala, Josu; Maguregui, Maite; Morillas, Héctor; de Diego, Alberto; Madariaga, Juan Manuel

    2013-03-01

    Tomato (Solanum lycopersicum) fruit samples, in two ripening stages, ripe (red) and unripe (green), collected from a cultivar in the North of Spain (Barrika, Basque Country), were analyzed directly, without any sample pretreatment, with two different Raman instruments (portable spectrometer coupled to a micro-videocamera and a confocal Raman microscope), using two different laser excitation wavelengths (514 and 785 nm, only for the confocal microscope). The combined use of these laser excitation wavelengths allows obtaining, in a short period of time, the maximum spectral information about the main organic compounds present in this fruit. The major identified components of unripe tomatoes were cutin and cuticular waxes. On the other hand, the main components on ripe tomatoes were carotenes, polyphenoles and polysaccharides. Among the carotenes, it was possible to distinguish the presence of lycopene from β-carotene with the help of both excitation wavelengths, but specially using the 514 nm one, which revealed specific overtones and combination tones of this type of carotene.

  10. Lipid droplets formation in human endothelial cells in response to polyunsaturated fatty acids and 1-methyl-nicotinamide (MNA); confocal Raman imaging and fluorescence microscopy studies.

    Science.gov (United States)

    Majzner, Katarzyna; Chlopicki, Stefan; Baranska, Malgorzata

    2016-04-01

    In this work the formation of lipid droplets (LDs) in human endothelial cells culture in response to the uptake of polyunsaturated fatty acids (PUFAs) was studied. Additionally, an effect of 1-methylnicotinamide (MNA) on the process of LDs formation was investigated. LDs have been previously described structurally and to some degree biochemically, however neither the precise function of LDs nor the factors responsible for LD induction have been clarified. Lipid droplets, sometimes referred in the literature as lipid bodies are organelles known to regulate neutrophil, eosinophil, or tumor cell functions but their presence and function in the endothelium is largely unexplored. 3D linear Raman spectroscopy was used to study LDs formation in vitro in a single endothelial cell. The method provides information about distribution and size of LDs as well as their composition. The incubation of endothelial cells with various PUFAs resulted in formation of LDs. As a complementary method for LDs identification a fluorescence microscopy was applied. Fluorescence measurements confirmed the Raman results suggesting endothelial cells uptake of PUFAs and subsequent LDs formation in the cytoplasm of the endothelium. Furthermore, MNA seem to potentiate intracellular uptake of PUFAs to the endothelium that may bear physiological and pharmacological significance. Confocal Raman imaging of HAoEC cell with LDs.

  11. Comprehensive Detection and Discrimination of Campylobacter Species by Use of Confocal Micro-Raman Spectroscopy and Multilocus Sequence Typing

    Science.gov (United States)

    Lu, Xiaonan; Huang, Qian; Miller, William G.; Aston, D. Eric; Xu, Jie; Xue, Feng; Zhang, Hongwei; Rasco, Barbara A.

    2012-01-01

    A novel strategy for the rapid detection and identification of traditional and emerging Campylobacter strains based upon Raman spectroscopy (532 nm) is presented here. A total of 200 reference strains and clinical isolates of 11 different Campylobacter species recovered from infected animals and humans from China and North America were used to establish a global Raman spectroscopy-based dendrogram model for Campylobacter identification to the species level and cross validated for its feasibility to predict Campylobacter-associated food-borne outbreaks. Bayesian probability coupled with Monte Carlo estimation was employed to validate the established Raman classification model on the basis of the selected principal components, mainly protein secondary structures, on the Campylobacter cell membrane. This Raman spectroscopy-based typing technique correlates well with multilocus sequence typing and has an average recognition rate of 97.21%. Discriminatory power for the Raman classification model had a Simpson index of diversity of 0.968. Intra- and interlaboratory reproducibility with different instrumentation yielded differentiation index values of 4.79 to 6.03 for wave numbers between 1,800 and 650 cm−1 and demonstrated the feasibility of using this spectroscopic method at different laboratories. Our Raman spectroscopy-based partial least-squares regression model could precisely discriminate and quantify the actual concentration of a specific Campylobacter strain in a bacterial mixture (regression coefficient, >0.98; residual prediction deviation, >7.88). A standard protocol for sample preparation, spectral collection, model validation, and data analyses was established for the Raman spectroscopic technique. Raman spectroscopy may have advantages over traditional genotyping methods for bacterial epidemiology, such as detection speed and accuracy of identification to the species level. PMID:22740711

  12. Near-infrared confocal micro-Raman spectroscopy combined with PCA-LDA multivariate analysis for detection of esophageal cancer

    Science.gov (United States)

    Chen, Long; Wang, Yue; Liu, Nenrong; Lin, Duo; Weng, Cuncheng; Zhang, Jixue; Zhu, Lihuan; Chen, Weisheng; Chen, Rong; Feng, Shangyuan

    2013-06-01

    The diagnostic capability of using tissue intrinsic micro-Raman signals to obtain biochemical information from human esophageal tissue is presented in this paper. Near-infrared micro-Raman spectroscopy combined with multivariate analysis was applied for discrimination of esophageal cancer tissue from normal tissue samples. Micro-Raman spectroscopy measurements were performed on 54 esophageal cancer tissues and 55 normal tissues in the 400-1750 cm-1 range. The mean Raman spectra showed significant differences between the two groups. Tentative assignments of the Raman bands in the measured tissue spectra suggested some changes in protein structure, a decrease in the relative amount of lactose, and increases in the percentages of tryptophan, collagen and phenylalanine content in esophageal cancer tissue as compared to those of a normal subject. The diagnostic algorithms based on principal component analysis (PCA) and linear discriminate analysis (LDA) achieved a diagnostic sensitivity of 87.0% and specificity of 70.9% for separating cancer from normal esophageal tissue samples. The result demonstrated that near-infrared micro-Raman spectroscopy combined with PCA-LDA analysis could be an effective and sensitive tool for identification of esophageal cancer.

  13. Confocal Raman microscopy and multivariate statistical analysis for determination of different penetration abilities of caffeine and propylene glycol applied simultaneously in a mixture on porcine skin ex vivo.

    Science.gov (United States)

    Mujica Ascencio, Saul; Choe, ChunSik; Meinke, Martina C; Müller, Rainer H; Maksimov, George V; Wigger-Alberti, Walter; Lademann, Juergen; Darvin, Maxim E

    2016-07-01

    Propylene glycol is one of the known substances added in cosmetic formulations as a penetration enhancer. Recently, nanocrystals have been employed also to increase the skin penetration of active components. Caffeine is a component with many applications and its penetration into the epidermis is controversially discussed in the literature. In the present study, the penetration ability of two components - caffeine nanocrystals and propylene glycol, applied topically on porcine ear skin in the form of a gel, was investigated ex vivo using two confocal Raman microscopes operated at different excitation wavelengths (785nm and 633nm). Several depth profiles were acquired in the fingerprint region and different spectral ranges, i.e., 526-600cm(-1) and 810-880cm(-1) were chosen for independent analysis of caffeine and propylene glycol penetration into the skin, respectively. Multivariate statistical methods such as principal component analysis (PCA) and linear discriminant analysis (LDA) combined with Student's t-test were employed to calculate the maximum penetration depths of each substance (caffeine and propylene glycol). The results show that propylene glycol penetrates significantly deeper than caffeine (20.7-22.0μm versus 12.3-13.0μm) without any penetration enhancement effect on caffeine. The results confirm that different substances, even if applied onto the skin as a mixture, can penetrate differently. The penetration depths of caffeine and propylene glycol obtained using two different confocal Raman microscopes are comparable showing that both types of microscopes are well suited for such investigations and that multivariate statistical PCA-LDA methods combined with Student's t-test are very useful for analyzing the penetration of different substances into the skin.

  14. Investigating the lignocellulosic composition during delignification using confocal raman spectroscopy, cross-polarization magic angle spinning carbon 13 - nuclear magnetic resonance (CP/MAS 13C- NMR) spectroscopy and atomic force microscopy

    CSIR Research Space (South Africa)

    Chunilall, Viren

    2012-03-01

    Full Text Available spectroscopy, Cross-Polarization Magic Angle Spinning Carbon 13 - Nuclear Magnetic Resonance (CP/MAS 13C-NMR) spectroscopy and Atomic Force Microscopy (AFM) in conjunction with image analysis. The confocal Raman results showed that there were differences...

  15. Probing the cellular damage in bacteria induced by GaN nanoparticles using confocal laser Raman spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Sahoo, Prasana, E-mail: prasanasahoo@gmail.com [Indira Gandhi Center for Atomic Research, Surface and Nanoscience Division (India); Murthy, P. Sriyutha [Bhabha Atomic Research Centre, Biofouling and Biofilm Processes Section, Water and Steam Chemistry Division (India); Dhara, S., E-mail: dhara@igcar.gov.in [Indira Gandhi Center for Atomic Research, Surface and Nanoscience Division (India); Venugopalan, V. P. [Bhabha Atomic Research Centre, Biofouling and Biofilm Processes Section, Water and Steam Chemistry Division (India); Das, A.; Tyagi, A. K. [Indira Gandhi Center for Atomic Research, Surface and Nanoscience Division (India)

    2013-08-15

    Understanding the mechanism of nanoparticle (NP) induced toxicity in microbes is of potential importance to a variety of disciplines including disease diagnostics, biomedical implants, and environmental analysis. In this context, toxicity to bacterial cells and inhibition of biofilm formation by GaN NPs and their functional derivatives have been investigated against gram positive and gram negative bacterial species down to single cellular level. High levels of inhibition of biofilm formation (>80 %) was observed on treatments with GaN NPs at sub-micro molar concentrations. These results were substantiated with morphological features investigated with field emission scanning electron microscope, and the observed changes in vibrational modes of microbial cells using Raman spectroscopy. Raman spectra provided molecular interpretation of cell damage by registering signatures of molecular vibrations of individual living microbial cells and mapping the interplay of proteins at the cell membrane. As compared to the untreated cells, Raman spectra of NP-treated cells showed an increase in the intensities of characteristic protein bands, which confirmed membrane damage and subsequent release of cellular contents outside the cells. Raman spectral mapping at single cellular level can facilitate understanding of the mechanistic aspect of toxicity of GaN NPs. The effect may be correlated to passive diffusion causing mechanical damage to the membrane or ingress of Ga{sup 3+} (ionic radius {approx}0.076 nm) which can potentially interfere with bacterial metabolism, as it resembles Fe{sup 2+} (ionic radius {approx}0.077 nm), which is essential for energy metabolism.

  16. Single-Bead Quantification of Peptide Loading Distribution for One-Bead One-Compound Library Synthesis Using Confocal Raman Spectroscopy.

    Science.gov (United States)

    Tang, Yuchen; Thillier, Yann; Liu, Ruiwu; Li, Xiaocen; Lam, Kit S; Gao, Tingjuan

    2017-07-05

    We report an analytical method to determine peptide loading of "one-bead one-compound" (OBOC) combinatorial peptide libraries at single-bead level. The quantification is based on a linear relationship between the amount of N-terminal amino groups on individual peptide beads and the intensity of Raman signal obtained from a specifically designed reporter labeled on amino groups. Confocal Raman spectroscopy was employed to characterize peptide loading of beads with defined peptide sequences and from OBOC combinatorial peptide libraries. Although amine loading of blank TentaGel beads was found to be uniform, peptide loading among beads of OBOC peptide libraries varied substantially, particularly for those libraries with long sequences. Construction of OBOC libraries can be monitored with this novel analytical technique so that synthetic conditions can be optimized for the preparation of high-quality OBOC peptide libraries. As the variability of peptide loading of individual library beads can significantly influence the screening results, quantitative information obtained by this method will allow us to gain insight into the complexity and challenge of OBOC library synthesis and screening.

  17. Investigation of the cutaneous penetration behavior of dexamethasone loaded to nano-sized lipid particles by EPR spectroscopy, and confocal Raman and laser scanning microscopy.

    Science.gov (United States)

    Lohan, Silke B; Saeidpour, Siavash; Solik, Agnieszka; Schanzer, Sabine; Richter, Heike; Dong, Pin; Darvin, Maxim E; Bodmeier, Roland; Patzelt, Alexa; Zoubari, Gaith; Unbehauen, Michael; Haag, Rainer; Lademann, Jürgen; Teutloff, Christian; Bittl, Robert; Meinke, Martina C

    2017-07-01

    An improvement of the penetration efficiency combined with the controlled release of actives in the skin can facilitate the medical treatment of skin diseases immensely. Dexamethasone (Dx), a synthetic glucocorticoid, is frequently used for the treatment of inflammatory skin diseases. To investigate the penetration of nano-sized lipid particles (NLP) loaded with Dx in comparison to a commercially available base cream, different techniques were applied. Electron paramagnetic resonance (EPR) spectroscopy was used to monitor the penetration of Dx, which was covalently labeled with the spin probe 3-(Carboxy)-2,2,5,5-tetramethyl-1-pyrrolidinyloxy (PCA). The penetration into hair follicles was studied using confocal laser scanning microscopy (CLSM) with curcumin-loaded NLP. The penetration of the vehicle was followed by confocal Raman microscopy (CRM). Penetration studies using excised porcine skin revealed a more than twofold higher penetration efficiency for DxPCA into the stratum corneum (SC) after 24h incubation compared to 4h incubation when loaded to the NLP, whereas when applied in the base cream, almost no further penetration was observed beyond 4h. The distribution of DxPCA within the SC was investigated by consecutive tape stripping. The release of DxPCA from the base cream after 24h in deeper SC layers and the viable epidermis was shown by EPR. For NLP, no release from the carrier was observed, although DxPCA was detectable in the skin after the complete SC was removed. This phenomenon can be explained by the penetration of the NLP into the hair follicles. However, penetration profiles measured by CRM indicate that NLP did not penetrate as deeply into the SC as the base cream formulation. In conclusion, NLP can improve the accumulation of Dx in the skin and provide a reservoir within the SC and in the follicular infundibula. Copyright © 2017 Elsevier B.V. All rights reserved.

  18. Real-time measurements of the redox states of c-type cytochromes in electroactive biofilms: a confocal resonance Raman Microscopy study.

    Science.gov (United States)

    Virdis, Bernardino; Millo, Diego; Donose, Bogdan C; Batstone, Damien J

    2014-01-01

    Confocal Resonance Raman Microscopy (CRRM) was used to probe variations of redox state of c-type cytochromes embedded in living mixed-culture electroactive biofilms exposed to different electrode polarizations, under potentiostatic and potentiodynamic conditions. In the absence of the metabolic substrate acetate, the redox state of cytochromes followed the application of reducing and oxidizing electrode potentials. Real-time monitoring of the redox state of cytochromes during cyclic voltammetry (CV) in a potential window where cytochromes reduction occurs, evidenced a measurable time delay between the oxidation of redox cofactors probed by CV at the electrode interface, and oxidation of distal cytochromes probed by CRRM. This delay was used to tentatively estimate the diffusivity of electrons through the biofilm. In the presence of acetate, the resonance Raman spectra of young (10 days, j = 208 ± 49 µA cm(-2)) and mature (57 days, j = 267 ± 73 µA cm(-2)) biofilms show that cytochromes remained oxidized homogeneously even at layers as far as 70 µm from the electrode, implying the existence of slow metabolic kinetics that do not result in the formation of a redox gradient inside the biofilm during anode respiration. However, old biofilms (80 days, j = 190 ± 37 µA cm(-2)) with thickness above 100 µm were characterized by reduced catalytic activity compared to the previous developing stages. The cytochromes in these biofilm were mainly in the reduced redox state, showing that only aged mixed-culture biofilms accumulate electrons during anode respiration. These results differ substantially from recent observations in pure Geobacter sulfurreducens electroactive biofilms, in which accumulation of reduced cytochromes is already observed in thinner biofilms, thus suggesting different bottlenecks in current production for mixed-culture and G. sulfurreducens biofilms.

  19. Real-time measurements of the redox states of c-type cytochromes in electroactive biofilms: a confocal resonance Raman Microscopy study.

    Directory of Open Access Journals (Sweden)

    Bernardino Virdis

    Full Text Available Confocal Resonance Raman Microscopy (CRRM was used to probe variations of redox state of c-type cytochromes embedded in living mixed-culture electroactive biofilms exposed to different electrode polarizations, under potentiostatic and potentiodynamic conditions. In the absence of the metabolic substrate acetate, the redox state of cytochromes followed the application of reducing and oxidizing electrode potentials. Real-time monitoring of the redox state of cytochromes during cyclic voltammetry (CV in a potential window where cytochromes reduction occurs, evidenced a measurable time delay between the oxidation of redox cofactors probed by CV at the electrode interface, and oxidation of distal cytochromes probed by CRRM. This delay was used to tentatively estimate the diffusivity of electrons through the biofilm. In the presence of acetate, the resonance Raman spectra of young (10 days, j = 208 ± 49 µA cm(-2 and mature (57 days, j = 267 ± 73 µA cm(-2 biofilms show that cytochromes remained oxidized homogeneously even at layers as far as 70 µm from the electrode, implying the existence of slow metabolic kinetics that do not result in the formation of a redox gradient inside the biofilm during anode respiration. However, old biofilms (80 days, j = 190 ± 37 µA cm(-2 with thickness above 100 µm were characterized by reduced catalytic activity compared to the previous developing stages. The cytochromes in these biofilm were mainly in the reduced redox state, showing that only aged mixed-culture biofilms accumulate electrons during anode respiration. These results differ substantially from recent observations in pure Geobacter sulfurreducens electroactive biofilms, in which accumulation of reduced cytochromes is already observed in thinner biofilms, thus suggesting different bottlenecks in current production for mixed-culture and G. sulfurreducens biofilms.

  20. Comment on "Observation of mutual diffusion of macromolecules in PS/PMMA binary films by confocal Raman microscopy" by C. Hu, X. Chen, J. Chen, W. Zhang and M. Q. Zhang, Soft Matter, 2012, 8, 4780.

    Science.gov (United States)

    Tomba, J Pablo

    2016-05-18

    A paper by Hu et al. (Soft Matter, 2012, 8, 4780) reports on the use of confocal Raman microscopy to resolve mutual diffusion between polystyrene (PS) and poly(methyl methacrylate) (PMMA). In-depth optical sectioning is employed to measure the diffusive broadening of the originally planar PS-PMMA interface, from which tracer and mutual diffusion coefficients and values for the PS-PMMA thermodynamic interaction parameter are extracted. Here, a reinterpretation of Hu's data that leads to a completely different scenario is presented, as apparent diffusive broadening can be mostly attributed to optical distortions inherent to the probe methodology. It also explains the lack of consistency of kinetic and thermodynamic parameters obtained by the authors from their diffusion analysis in comparison with earlier published data on this system. Overall, it highlights the importance of carrying out appropriate data analysis when confocal Raman microscopy is applied in dry depth-profiling investigations.

  1. Non-invasive insight into the release mechanisms of a poorly soluble drug from amorphous solid dispersions by confocal Raman microscopy.

    Science.gov (United States)

    Punčochová, Kateřina; Vukosavljevic, Branko; Hanuš, Jaroslav; Beránek, Josef; Windbergs, Maike; Štěpánek, František

    2016-04-01

    In this study, we investigated the release mechanism of the poorly water soluble drug aprepitant from different amorphous solid dispersions using confocal Raman microscopy (CRM). Solid dispersions were fabricated based on either Soluplus®, as an amphiphilic copolymer and solubilizer, or on polyvinylpyrrolidone, as a hydrophilic polymer, in order to elucidate the influence of the polymer characteristics on the drug form and dissolution mechanisms. Aprepitant exhibited its amorphous form in both solid dispersions. However, the release differed depending on the polymer. The high complexation effect of Soluplus was shown to be a crucial factor for stabilization of the amorphous drug, resulting in continuous release without any recrystallization of aprepitant. In contrast, solid dispersions based on polyvinylpyrrolidone showed a different mechanism of dissolution; due to the good affinity of PVP and water, the polymer is dissolving fast, leading to phase separation and local recrystallization of the drug. The study highlights the complexity of release processes from solid dispersions and elucidates the influence of the polymer on drug release kinetics.

  2. Study of intracellular delivery of doxorubicin from poly(lactide-co-glycolide) nanoparticles by means of fluorescence lifetime imaging and confocal Raman microscopy.

    Science.gov (United States)

    Romero, Gabriela; Qiu, Yuan; Murray, Richard A; Moya, Sergio E

    2013-02-01

    The intracellular delivery of Doxorubicin (Dox) from poly(lactide-co-glycolide) (PLGA) nanoparticles stabilised with bovine serum albumin, in HepG2 cells, is studied via flow cytometry, fluorescence lifetime imaging microscopy (FLIM), confocal Raman microscopy (CRM) and cell viability studies. Flow cytometry shows that the initial uptake of PLGA and Dox follow the same kinetics. However, following 8 h of incubation, the fluorescence intensity and cellular uptake of Dox decreases, while in the case of PLGA both parameters remain constant. FLIM shows the presence of a single-lifetime species, with a lifetime of 1.15 ns when measured inside the cells. Cell viability decreases by approximately 20% when incubated for 24 h with PLGA loaded with Dox, with a particle concentration of 100 µg · mL(-1). At the single-cell level, CRM shows changes in the bands from DNA and proteins in the cell nucleus when incubated with PLGA loaded with Dox. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. Follow up of the functioning of a lithium-polymer battery using confocal Raman micro-spectroscopy; Suivi du fonctionnement d`un accumulateur lithium-polymere par microspectrometrie Raman confocale

    Energy Technology Data Exchange (ETDEWEB)

    Rey, I.; Bruneel, J.L.; Lassegues, J.C.; Servant, L. [Bordeaux-1 Univ., 33 - Talence (France); Baudry, P.; Lascaud, S. [Electricite de France, 77 - Moret sur Loing (France). Direction des Etudes et Recherches; Majastre, H. [Bollore Technologies, 29 - Quimper (France)

    1996-12-31

    The confocal Raman micro-spectroscopy has been used for the study of a Lithium/polymer electrolyte-LiTFSI/V{sub 2}O{sub 5} type battery in which the polymer electrolyte thickness is of about 80 {mu}m. The analysis is performed on the side of the battery thanks to a specially designed cell which preserves all the characteristics of the real system. The analysis is performed on 20 points aligned between the anode and the cathode and with a depth of several tenth of {mu}m. The analysis of data obtained during charging/output cycles allows to evaluate the gradients of salt concentration inside the electrolyte, the pollutions of LiOH, Li{sub 2}CO{sub 3}, Li{sub 2}O and Li{sub 3}N -type at the lithium interface, but also the structural modifications of the cathode material. The in-situ study of concentration gradients inside the electrolyte is of prime importance for the understanding of dendrites growth. (J.S.) 11 refs.

  4. Use of in situ and confocal Raman spectroscopy to study the nature and distribution of carotenoids in brown patinas from a deteriorated wall painting in Marcus Lucretius House (Pompeii).

    Science.gov (United States)

    Maguregui, M; Knuutinen, U; Trebolazabala, J; Morillas, H; Castro, K; Martinez-Arkarazo, I; Madariaga, J M

    2012-02-01

    Colonisation of wall paintings by microorganisms and other organisms is a well-known problematic phenomenon. Besides taxonomic identification of the biodeteriogen, it is essential to evaluate the consequences of the colonisation, e.g., unsightly coloured patinas. This work proposes new methodology for characterisation of the nature of the main carotenoids and their distribution in brown stains or patinas of a deteriorated wall painting on the north wall of the atrium of Marcus Lucretius House (Pompeii, Italy). Characterisation of the brown patinas and surrounding areas (plaster and polychromy) from the wall painting started with in situ screening using, mainly, a portable Raman instrument with a handheld FTIR (DRIFTS sampling interface) in order to select the sampling areas suitable for further analysis in the laboratory. Two wall painting fragments were then analysed in the laboratory in two steps. First, microscopic observations (SEM and phase-contrast microscopy) were used to determine whether biodeteriogens were present in the samples. In a second step, confocal Raman microscopy (785 and 514 nm excitation lasers) was used to characterise the main biogenic compounds of the brown stains. Because of the resonance Raman effect (514 nm excitation laser), it was possible to obtain reliable Raman features to assign not only the nature of the main biogenic pigments (carotenoids) present in the stains, but also their spatial conformation. Moreover, Raman confocal applications, for example, Raman imaging and depth profiling were also used in a first attempt to determine the distribution of biosynthesised carotenoids in the stains, and to determine the thickness of the brown patinas.

  5. In vivo confocal Raman microscopic determination of depth profiles of the stratum corneum lipid organization influenced by application of various oils.

    Science.gov (United States)

    Choe, ChunSik; Schleusener, Johannes; Lademann, Jürgen; Darvin, Maxim E

    2017-08-01

    The intercellular lipids (ICL) of stratum corneum (SC) play an important role in maintaining the skin barrier function. The lateral and lamellar packing order of ICL in SC is not homogenous, but rather depth-dependent. This study aimed to analyze the influence of the topically applied mineral-derived (paraffin and petrolatum) and plant-derived (almond oil and jojoba oil) oils on the depth-dependent ICL profile ordering of the SC in vivo. Confocal Raman microscopy (CRM), a unique tool to analyze the depth profile of the ICL structure non-invasively, is employed to investigate the interaction between oils and human SC in vivo. The results show that the response of SC to oils' permeation varies in the depths. All oils remain in the upper layers of the SC (0-20% of SC thickness) and show predominated differences of ICL ordering from intact skin. In these depths, skin treated with plant-derived oils shows more disordered lateral and lamellar packing order of ICL than intact skin (p0.1), except plant-derived oils at the depth 30% of SC thickness. In the deeper layers of the SC (60-100% of SC thickness), no difference between ICL lateral packing order of the oil-treated and intact skin can be observed, except that at the depths of 70-90% of the SC thickness, where slight changes with more disorder states are measured for plant-derived oil treated skin (p<0.1), which could be explained by the penetration of free fatty acid fractions in the deep-located SC areas. Both oil types remain in the superficial layers of the SC (0-20% of the SC thickness). Skin treated with mineral- and plant-derived oils shows significantly higher disordered lateral and lamellar packing order of ICL in these layers of the SC compared to intact skin. Plant-derived oils significantly changed the ICL ordering in the depths of 30% and 70-90% of the SC thickness, which is likely due to the penetration of free fatty acids in the deeper layers of the SC. Copyright © 2017 Japanese Society for

  6. 拉曼光谱法测定天然脂肪球脂质成分%Lipid Composition of Native Milk Fat Globules by Confocal Raman Microscopy

    Institute of Scientific and Technical Information of China (English)

    罗洁; 王宇涵; 李奕琦; 邹郁宁; 吕新; 任发政

    2015-01-01

    Native fat globules composed mainly of triglycerides are secreted as droplets of variable size .The size of fat globules affects the form of fat in dairy products and final functionality ,which depends mainly on the composition of the globules and membrane .However ,the relation between the composition and size of fat globules has not been studied in detail .In this study ,differences in the lipid content and fatty acid composition related to the size of native fat globules were investigated using confocal Raman spectroscopy ,which offers the possibility of acquisition and analysis of the Raman signal without disruption of a single fat globule in natural suspension .The results showed small fat globules (SFG) had a higher ratio of band intensities at 2 885/2 850 cm -1 ,indicating SFG tend to have a triglyceride core in a fluid state with a milk fat globule membrane in a crystalline state .In addition ,the SFG had a higher level of unsaturation compared to large fat globules ,shown by a lower ratio at 1 655/1 443 cm -1 .Using cream with selected SFG would allow a harder and more costly churning process but lead to a softer butter .%天然脂肪球主要由甘油三酯构成,以不同大小的球状形式分泌而得。不同大小的脂肪球的球体和膜组成成分不同,从而影响了脂肪在乳中的存在形式和最终的乳品功能特性。然而,不同大小的脂肪球成分的差异尚未完全阐明。利用拉曼光谱测定特定大小脂肪球及膜的脂质和脂肪酸组成。拉曼光谱能够从单个脂肪球获得特定拉曼信号,并且在不破坏天然脂肪球构型的情况下进行测定。结果显示,小脂肪球在2885/2850 cm -1处条带信号较高,表明小脂肪球趋于形成结晶态的脂肪球膜包裹流动态的甘油三酯内核的结构。此外,小脂肪球与大脂肪球相比,1655/1443 cm -1的条带信号较低,表明小脂肪球的脂肪酸不饱和程度较高。总之,从本实验结果

  7. Giant Raman gain in silicon nanocrystals

    National Research Council Canada - National Science Library

    Sirleto, Luigi; Ferrara, Maria Antonietta; Nikitin, Timur; Novikov, Sergei; Khriachtchev, Leonid

    2012-01-01

    ... of next generation nonlinear photonic devices. Here we report the first observation of stimulated Raman scattering in silicon nanocrystals embedded in a silica matrix under non-resonant excitation at infrared wavelengths (~1.5 μm...

  8. Investigation of the nanodomain structure formation by piezoelectric force microscopy and Raman confocal microscopy in LiNbO{sub 3} and LiTaO{sub 3} crystals

    Energy Technology Data Exchange (ETDEWEB)

    Shur, V. Ya.; Zelenovskiy, P. S.; Nebogatikov, M. S.; Alikin, D. O.; Sarmanova, M. F.; Ievlev, A. V.; Mingaliev, E. A.; Kuznetsov, D. K. [Ferroelectric Laboratory, Institute of Physics and Applied Mathematics, Ural State University, 620083 Ekaterinburg (Russian Federation)

    2011-09-01

    Piezoelectric force microscopy (PFM) and Raman confocal microscopy have been used for studying the nanodomain structures in congruent LiNbO{sub 3} and LiTaO{sub 3} crystals. The high-resolution nanodomain images at the surface were observed via PFM. Raman confocal microscopy has been used for the visualization of the nanodomain structures in the bulk via layer-by-layer scanning at various depths. It has been shown experimentally that the nanodomain images obtained at different depths correspond to domain images at the polar surface obtained at different moments: the deeper the nanodomain, the earlier the moment. Such a correlation was applied for the reconstruction of the evolution of the domain structures with charged domain walls. The studied domain structures were obtained in highly non-equilibrium switching conditions realized in LiNbO{sub 3} and LiTaO{sub 3} via pulse laser irradiation and the electric field poling of LiNbO{sub 3}, with the surface layer modified by ion implantation. The revealed main stages of the domain structure evolution allow the authors to demonstrate that all geometrically different nanodomain structures observed in LiNbO{sub 3} and LiTaO{sub 3} appeared as a result of discrete switching.

  9. DFT:B3LYP/3-21G theoretical insights on the confocal Raman experimental observations in skin dermis of healthy young, healthy elderly, and diabetic elderly women

    Science.gov (United States)

    Téllez Soto, Claudio Alberto; Pereira, Liliane; dos Santos, Laurita; Rajasekaran, Ramu; Fávero, Priscila; Martin, Airton Abrahão

    2016-12-01

    In the confocal Raman spectra of skin dermis, the band area in the spectral region of proline and hydroxyproline varies according to the age and health condition of the volunteers, classified as healthy young women, healthy elderly women, and diabetic elderly women. Another observation refers to the intensity variation and negative Raman shift of the amide I band. To understand these effects, we adopted a model system using the DFT/B3LYP:3-21G procedure, considering the amino acid chain formed by glycine, hydroxyproline, proline, and alanine, which interacts with two and six water molecules. Through these systems, polarizability variations were analyzed to correlate its values with the observed Raman intensities of the three groups of volunteers and to assign the vibrational spectra of the skin dermis. As a way to correlate other experimental trends, we propose a model of chemical reaction of water interchange between the bonding amino acids, in which water molecules are attached with glucose by hydrogen bonds. The theoretical results are in accordance with the observed experimental trends.

  10. A method for an approximate determination of a polymer-rich-domain concentration in phase-separated poly(N-isopropylacrylamide) aqueous solution by means of confocal Raman microspectroscopy combined with optical tweezers.

    Science.gov (United States)

    Shoji, Tatsuya; Nohara, Riku; Kitamura, Noboru; Tsuboi, Yasuyuki

    2015-01-07

    The paper demonstrates that a confocal Raman microspectroscope combined with optical tweezers is a promising technique to estimate polymer concentration in polymer-rich domain in phase-separated-aqueous polymer solution. The sample polymer is poly-(N-isopropylacrylamide) (PNIPAM) that is well-known as a representative thermo-responsive polymer. Optical tweezers can selectively trap the polymer-rich domain at the focal point in non-contact and non-intrusive modes. Such situation allows us to determine polymer concentration in the domain, which has been unclear due to a lack of appropriate analytical technique. It is applicable for a variety of other thermo-responsive polymers. Copyright © 2014 Elsevier B.V. All rights reserved.

  11. 共聚焦激光拉曼光谱技术鉴定三份激光打印机墨迹%Identifying Three Ink Marks from Laser Printers with Confocal Raman Technique

    Institute of Scientific and Technical Information of China (English)

    尤伟; 陆俭洁

    2011-01-01

    使用共聚焦激光拉曼光谱仪对送检的三份激光打印机墨迹进行鉴定。在高倍显微镜下,发现各检材的细节特征有明显区别;使用785 nm波长激光光源,对各检材进行测定,发现不同检材的激光拉曼光谱图中拉曼峰型,峰个数及峰位移有明显区别。通过上述检测,可以得出鉴定结论。%This paper is to introduce the experiment of identifying three ink marks from laser printers with confocal Raman spectrometer.Under the high-power microscope,the details of characteristics of the samples are obviously different.The parameters(e.g.type,number,shift) of Raman peaks of the samples,being determined by using 785nm laser light source,are also obviously different.It's easy to obtain the result of appraisal from the determination above.

  12. 唇腺炎性病变组织的共聚焦显微拉曼光谱特征研究%Research on the Confocal Raman micro­spectroscopic Characters of Inflammatory Labial Gland Tissues

    Institute of Scientific and Technical Information of China (English)

    薛丽丽; 骆献阳; 蔡巧玲; 孙佩; 陈培琼; 闫冰

    2015-01-01

    目的:研究唇腺炎性病变组织的拉曼光谱指纹特征,为拉曼光谱技术临床鉴别诊断唇腺炎性病变提供理论基础。方法:收集舍格伦综合征病变唇腺30例、唇腺急性炎症组织18例及正常唇腺组织30例,应用激光共聚焦显微拉曼光谱仪对唇腺组织进行拉曼光谱检测。应用主成分分析法(Principal component analysis,PCA)及判别函数(Discrimination function analysis,DFA)对光谱数据进行分析,研究唇腺组织光谱指纹诊断价值。结果:唇腺炎症组织与正常组织光谱间存在光谱指纹差异,这些差异代表了某些蛋白、核酸及脂类物质等生物大分子发生改变。PCA-DFA 分析发现这些差异性拉曼光谱具有鉴别诊断价值,可以区分不同唇腺组织,总体诊断准确率达91.8%,经交互验证后准确率为89.4%。结论:不同唇腺炎症组织及正常组织间拉曼光谱存在差异,不仅揭示生物大分子改变,还具有临床鉴别诊断价值。拉曼光谱技术在唇腺炎性病变组织鉴别诊断具有巨大应用潜力。%Objective:Research the Raman spectra of inflammatory labial gland tissues in order to provide a research-based theoretical foundation for applying Raman spectroscopy to diagnoses the inflammatory labial gland diseases.Meth­ods:30 samples of Sjogren’s syndrome labial glands,18 samples of acute inflammatory labial glands and 30 samples of normal labial glands were collected and scanned by confocal Raman micro-spectrometer.The methods of principal com-ponent analysis (PCA)and discrimination function analysis (DFA)were employed to analyze the spectral data and dis-criminate the different tissues.Results:Differences were discovered between in the Raman spectra of various labial gland tissues,which were assigned to biomolecules such as proteins,nucleic acids and lipids.The accuracy of discrimination carried out by PCA-DFA reached 91.8% and the accuracy of cross

  13. Probing halo molecules with nonresonant light

    CERN Document Server

    Lemeshko, Mikhail

    2009-01-01

    We show that halo molecules can be probed by "shaking" in a pulsed nonresonant laser field. The field introduces a centrifugal term which expels the highest vibrational level from the potential that binds it. Our numerical simulations as well as an analytic model applied to the Rb$_2$ and KRb Feshbach molecules indicate that shaking by feasible laser pulses can be used to accurately recover the square of the vibrational wavefunction and, by inversion, also the molecular potential.

  14. Non-resonant Nanoscale Extreme Light Confinement

    Energy Technology Data Exchange (ETDEWEB)

    Subramania, Ganapathi Subramanian [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Huber, Dale L. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2014-09-01

    A wide spectrum of photonics activities Sandia is engaged in such as solid state lighting, photovoltaics, infrared imaging and sensing, quantum sources, rely on nanoscale or ultrasubwavelength light-matter interactions (LMI). The fundamental understanding in confining electromagnetic power and enhancing electric fields into ever smaller volumes is key to creating next generation devices for these programs. The prevailing view is that a resonant interaction (e.g. in microcavities or surface-plasmon polaritions) is necessary to achieve the necessary light confinement for absorption or emission enhancement. Here we propose new paradigm that is non-resonant and therefore broadband and can achieve light confinement and field enhancement in extremely small areas [~(λ/500)^2 ]. The proposal is based on a theoretical work[1] performed at Sandia. The paradigm structure consists of a periodic arrangement of connected small and large rectangular slits etched into a metal film named double-groove (DG) structure. The degree of electric field enhancement and power confinement can be controlled by the geometry of the structure. The key operational principle is attributed to quasistatic response of the metal electrons to the incoming electromagnetic field that enables non-resonant broadband behavior. For this exploratory LDRD we have fabricated some test double groove structures to enable verification of quasistatic electronic response in the mid IR through IR optical spectroscopy. We have addressed some processing challenges in DG structure fabrication to enable future design of complex sensor and detector geometries that can utilize its non-resonant field enhancement capabilities.].

  15. Aligning molecules with intense nonresonant laser fields

    DEFF Research Database (Denmark)

    Larsen, J.J.; Safvan, C.P.; Sakai, H.

    1999-01-01

    Molecules in a seeded supersonic beam are aligned by the interaction between an intense nonresonant linearly polarized laser field and the molecular polarizability. We demonstrate the general applicability of the scheme by aligning I2, ICl, CS2, CH3I, and C6H5I molecules. The alignment is probed...... by mass selective two dimensional imaging of the photofragment ions produced by femtosecond laser pulses. Calculations on the degree of alignment of I2 are in good agreement with the experiments. We discuss some future applications of laser aligned molecules....

  16. Resilient non-resonant divertors for stellarators

    Science.gov (United States)

    Bader, A.; Boozer, A. H.; Hegna, C. C.; Lazerson, S. A.

    2016-10-01

    In this work, we investigate whether resilient non-resonant divertor solutions exist for optimized stellarators. Resiliency is measured by the consistency of performance over a broad range of operational states, such as through bootstrap current and modified plasma pressures. A non-resonant configuration is one where the crucial topological feature is the existence and sharpness of ridges along the last closed flux surface. We develop a modified field-line following method for testing the resiliency of stellarator divertors and apply it to altered HSX configurations generated by varying external coil currents, wall positioning, and internal plasma currents. We compare a magnetic diffusion calculation with a ``zero-diffusion'' calculation that endeavors to measure the first escaping flux tubes. The results from these calculations are corroborated with a more complete edge simulation with EMC3-EIRENE. The EMC3-EIRENE simulations show resilient helical stripes that are consistent with the simpler field line following methods. The goal of the study is to find a metric for edge/divertor optimization of stellarators, a crucial piece that is missing from current optimization schemes. Work supported by DE-SC0006103 and DE-FG02-93ER54222,.

  17. 不同品种牛乳脂质的共聚焦拉曼光谱指纹图谱%Lipid Composition of Different Breeds of Milk Fat Globules by Confocal Raman Mic roscopy

    Institute of Scientific and Technical Information of China (English)

    罗洁; 王紫薇; 宋君红; 庞瑞鹏; 任发政

    2016-01-01

    不同品种的乳脂肪球的组成成分不同,从而导致脂肪在乳中的存在形式和最终的乳品品质存在差异。利用拉曼光谱测定黑白花牛乳、水牛乳及牦牛乳中脂质球的脂质和脂肪酸成分,比较不同品种牛乳的脂质组成差异。结果显示,牦牛乳的2885/2850 cm-1比值较高,表明牦牛乳脂质球趋于形成结晶态脂肪球膜包裹流动态内核的结构。与黑白花牛乳相比,牦牛和水牛乳的1655/1443 cm -1比值较高,表明黑白花牛乳的脂肪酸不饱和程度低于其他两种牛乳;水牛乳小脂肪球的脂肪酸不饱和度高于牦牛乳,大脂肪球的则低于牦牛乳。综上可知,用牦牛乳分离而得的稀奶油较其他牛乳难熔化,搅拌耗时更长,但形成的黄油更柔软;而水牛乳由于脂肪球较大,适用于奶油的加工和脂肪球膜的分离。%Different breeds of cows affect the form of fat exist in dairy products and the final functionality ,which depended main‐ly on the composition of the milk fat globules(MFG) .However ,the relationship between the composition and breeds has not been illuminated .In our study ,differences in the lipid content and fatty acid composition of native bovine ,buffalo and yak M FG were investigated by confocal Raman spectroscopy .The research offers the possibility of acquisition and analysis of the Raman signal without disruption of the structure of fat globule .The results showed that yak MFG had a higher ratio of band intensities at 2 885/2 850 cm -1 ,indicating yak MFG tend to have a triglyceride core in a fluid state with a milk fat globule membrane in a crystalline state .The buffalo and yak MFG had a higher level of unsaturation compared to bovine MFG ,shown by a higher ratio of band intensities at 1 655/1 744 cm -1 .The results indicate that small MFG of buffalo is more unsaturated than yak ,while the large MFG of buffalo is less unsaturated than the yak .Thus ,selective use of

  18. Human brain cancer studied by resonance Raman spectroscopy

    Science.gov (United States)

    Zhou, Yan; Liu, Cheng-Hui; Sun, Yi; Pu, Yang; Boydston-White, Susie; Liu, Yulong; Alfano, Robert R.

    2012-11-01

    The resonance Raman (RR) spectra of six types of human brain tissues are examined using a confocal micro-Raman system with 532-nm excitation in vitro. Forty-three RR spectra from seven subjects are investigated. The spectral peaks from malignant meningioma, stage III (cancer), benign meningioma (benign), normal meningeal tissues (normal), glioblastoma multiforme grade IV (cancer), acoustic neuroma (benign), and pituitary adenoma (benign) are analyzed. Using a 532-nm excitation, the resonance-enhanced peak at 1548 cm-1 (amide II) is observed in all of the tissue specimens, but is not observed in the spectra collected using the nonresonance Raman system. An increase in the intensity ratio of 1587 to 1605 cm-1 is observed in the RR spectra collected from meningeal cancer tissue as compared with the spectra collected from the benign and normal meningeal tissue. The peak around 1732 cm-1 attributed to fatty acids (lipids) are diminished in the spectra collected from the meningeal cancer tumors as compared with the spectra from normal and benign tissues. The characteristic band of spectral peaks observed between 2800 and 3100 cm-1 are attributed to the vibrations of methyl (-CH3) and methylene (-CH2-) groups. The ratio of the intensities of the spectral peaks of 2935 to 2880 cm-1 from the meningeal cancer tissues is found to be lower in comparison with that of the spectral peaks from normal, and benign tissues, which may be used as a distinct marker for distinguishing cancerous tissues from normal meningeal tissues. The statistical methods of principal component analysis and the support vector machine are used to analyze the RR spectral data collected from meningeal tissues, yielding a diagnostic sensitivity of 90.9% and specificity of 100% when two principal components are used.

  19. Neurosurgical confocal endomicroscopy: A review of contrast agents, confocal systems, and future imaging modalities

    Directory of Open Access Journals (Sweden)

    Aqib H Zehri

    2014-01-01

    Full Text Available Background: The clinical application of fluorescent contrast agents (fluorescein, indocyanine green, and aminolevulinic acid with intraoperative microscopy has led to advances in intraoperative brain tumor imaging. Their properties, mechanism of action, history of use, and safety are analyzed in this report along with a review of current laser scanning confocal endomicroscopy systems. Additional imaging modalities with potential neurosurgical utility are also analyzed. Methods: A comprehensive literature search was performed utilizing PubMed and key words: In vivo confocal microscopy, confocal endomicroscopy, fluorescence imaging, in vivo diagnostics/neoplasm, in vivo molecular imaging, and optical imaging. Articles were reviewed that discussed clinically available fluorophores in neurosurgery, confocal endomicroscopy instrumentation, confocal microscopy systems, and intraoperative cancer diagnostics. Results: Current clinically available fluorescent contrast agents have specific properties that provide microscopic delineation of tumors when imaged with laser scanning confocal endomicroscopes. Other imaging modalities such as coherent anti-Stokes Raman scattering (CARS microscopy, confocal reflectance microscopy, fluorescent lifetime imaging (FLIM, two-photon microscopy, and second harmonic generation may also have potential in neurosurgical applications. Conclusion: In addition to guiding tumor resection, intraoperative fluorescence and microscopy have the potential to facilitate tumor identification and complement frozen section analysis during surgery by providing real-time histological assessment. Further research, including clinical trials, is necessary to test the efficacy of fluorescent contrast agents and optical imaging instrumentation in order to establish their role in neurosurgery.

  20. [Artefacts of confocal microscopy].

    Science.gov (United States)

    Vekshin, N L; Frolov, M S

    2014-01-01

    Typical artefacts caused by using confocal fluorescent microscopy while studying living cells are considered. The role of light scattering, mobility, staining, local concentrations, etc. is discussed.

  1. Virtual pinhole confocal microscope

    Energy Technology Data Exchange (ETDEWEB)

    George, J.S.; Rector, D.M.; Ranken, D.M. [Los Alamos National Lab., NM (United States). Biophysics Group; Peterson, B. [SciLearn Inc. (United States); Kesteron, J. [VayTech Inc. (United States)

    1999-06-01

    Scanned confocal microscopes enhance imaging capabilities, providing improved contrast and image resolution in 3-D, but existing systems have significant technical shortcomings and are expensive. Researchers at Los Alamos National Laboratory have developed a novel approach--virtual pinhole confocal microscopy--that uses state of the art illumination, detection, and data processing technologies to produce an imager with a number of advantages: reduced cost, faster imaging, improved efficiency and sensitivity, improved reliability and much greater flexibility. Work at Los Alamos demonstrated proof of principle; prototype hardware and software have been used to demonstrate technical feasibility of several implementation strategies. The system uses high performance illumination, patterned in time and space. The authors have built functional confocal imagers using video display technologies (LCD or DLP) and novel scanner based on a micro-lens array. They have developed a prototype system for high performance data acquisition and processing, designed to support realtime confocal imaging. They have developed algorithms to reconstruct confocal images from a time series of spatially sub-sampled images; software development remains an area of active development. These advances allow the collection of high quality confocal images (in fluorescence, reflectance and transmission modes) with equipment that can inexpensively retrofit to existing microscopes. Planned future extensions to these technologies will significantly enhance capabilities for microscopic imaging in a variety of applications, including confocal endoscopy, and confocal spectral imaging.

  2. Spectrally encoded confocal microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Tearney, G.J.; Webb, R.H.; Bouma, B.E. [Wellman Laboratories of Photomedicine, Massachusetts General Hospital, 50 Blossom Street, BAR 703, Boston, Massachusetts 02114 (United States)

    1998-08-01

    An endoscope-compatible, submicrometer-resolution scanning confocal microscopy imaging system is presented. This approach, spectrally encoded confocal microscopy (SECM), uses a quasi-monochromatic light source and a transmission diffraction grating to detect the reflectivity simultaneously at multiple points along a transverse line within the sample. Since this method does not require fast spatial scanning within the probe, the equipment can be miniaturized and incorporated into a catheter or endoscope. Confocal images of an electron microscope grid were acquired with SECM to demonstrate the feasibility of this technique. {copyright} {ital 1998} {ital Optical Society of America}

  3. Non-resonant triple alpha reaction rate at low temperature

    Energy Technology Data Exchange (ETDEWEB)

    Itoh, T.; Tamii, A.; Aoi, N.; Fujita, H.; Hashimoto, T.; Miki, K.; Ogata, K. [Research Center for Nuclear Physics, Osaka University, Ibaraki, Osaka 567-0047 (Japan); Carter, J.; Donaldson, L.; Sideras-Haddad, E. [Schools of Physics, University of Witwatersrand, Johannesburg 2050 (South Africa); Furuno, T.; Kawabata, T. [Departments of Physics, Kyoto University, Sakyo, Kyoto, 606-8502 (Japan); Kamimura, M. [RIKEN Nishina Center, Wako, Saitama, 351-0198 (Japan); Nemulodi, F.; Neveling, R.; Smit, F. D.; Swarts, C. [iThemba Laboratory for Accelerator Based Sciences Somerset, West, 7129 (South Africa)

    2014-05-02

    Our experimental goal is to study the non-resonant triple alpha reaction rate at low temperture (T < 10{sup 8} K). The {sup 13}C(p,d) reaction at 66 MeV has been used to probe the alpha-unbound continuum state in {sup 12}C just below the 2{sup nd} 0{sup +} state at 7.65 MeV. The transition strength to the continuum state is predicted to be sensitive to the non-resonant triple alpha reaction rate. The experiment has been performed at iThemba LABS. We report the present status of the experiment.

  4. Non-resonant terahertz field enhancement in periodically arranged nanoslits

    DEFF Research Database (Denmark)

    Novitsky, Andrey; Ivinskaya, Aliaksandra; Zalkovskij, Maksim;

    2012-01-01

    We analyze ultra strong non-resonant field enhancement of THz field in periodic arrays of nanoslits cut in ultrathin metal films. The main feature of our approach is that the slit size and metal film thickness are several orders of magnitude smaller than the wavelength λ of the impinging radiation....... Two regimes of operation are found. First, when the grating period P ... approaches the THz wavelength but before entering the Raleigh-Wood anomaly, the field enhancement in nanoslit stays close to that in a single isolated slit, i.e., the well-known inversefrequency dependence. Both regimes are non-resonant and thus extremely broadband for P

  5. Revisiting the Young's double slit experiment for background-free nonlinear Raman spectroscopy and microscopy.

    Science.gov (United States)

    Gachet, David; Brustlein, Sophie; Rigneault, Hervé

    2010-05-28

    In the Young's double slit experiment, the spatial shift of the interference pattern projected onto a screen is directly related to the phase difference between the fields diffracted by the two slits. We apply this property to fields emitted by nonlinear processes and thus demonstrate background-free coherent anti-Stokes Raman scattering microscopy near an axial interface between a resonant and a nonresonant medium. This method is relevant to remove the nonresonant background in other coherent resonant processes.

  6. The Correlation Confocal Microscope

    CERN Document Server

    Simon, D S

    2010-01-01

    A new type of confocal microscope is described which makes use of intensity correlations between spatially correlated beams of light. It is shown that this apparatus leads to significantly improved transverse resolution.

  7. Non-resonant magnetic braking on JET and TEXTOR

    DEFF Research Database (Denmark)

    Sun, Y.; Liang, Y.; Shaing, K.C.

    2012-01-01

    The non-resonant magnetic braking effect induced by a non-axisymmetric magnetic perturbation is investigated on JET and TEXTOR. The collisionality dependence of the torque induced by the n = 1, where n is the toroidal mode number, magnetic perturbation generated by the error field correction coil...

  8. Nonresonant Metamaterials with an Ultra-High Permittivity

    Institute of Scientific and Technical Information of China (English)

    HE Xiao-Yang; CHEN Qi; LI Lin-Cui; YANG Chun; LI Biao; ZHOU Bang-Hua; TANG Chuan-Xiang

    2011-01-01

    @@ A nonresonant structure composed of metal cut-wires for realization of metamaterials is proposed.This kind of metamaterial works at an ultra broad bandwidth with uniform permittivity.Theoretical analysis and numerical simulations are carried out to study this inclusion and expression for the effective permittivity is given.Several methods are studied to enhance the permittivity and a nonresonant metamaterial with an ultra-high permittivity is obtained.A demonstration shows that the permittivity of this metamaterial can be as high as 145.%A nonresonant structure composed of metal cut-wires for realization of metamaterials is proposed. This kind of metamaterial works at an ultra broad bandwidth with uniform permittivity. Theoretical analysis and numerical simulations are carried out to study this inclusion and expression for the effective permittivity is given. Several methods are studied to enhance the permittivity and a nonresonant metamaterial with an ultra-high permittivity is obtained. A demonstration shows that the permittivity of this metamaterial can be as high as 145.

  9. Basic confocal microscopy

    Directory of Open Access Journals (Sweden)

    Manuela Monti

    2012-03-01

    Full Text Available This is an eleven chapter’s effort done by a bunch of Authors coordinated by Prof. R.L. Price and W.G. Jerome (who have personally written almost half of the book that with great skills are revealing us the secrets of confocal microscopy. Considering the significant progresses in different fields of biology, confocal microscopy is extremely important to dynamically see all the different molecules involved in the controlling networks build up by gene expressions in time and space. Necessary prerequisites to accomplish such goals are some fundamental microscopic technologies well and clearly presented in the first chapters....

  10. Confocal scanning microscopy

    DEFF Research Database (Denmark)

    Bariani, Paolo

    This report is based on a metrological investigation on confocal microscopy technique carried out by Uffe Rolf Arlø Theilade and Paolo Bariani. The purpose of the experimental activity was twofold a metrological instrument characterization and application to assessment of rough PP injection moulded...... replicated topography. Confocal microscopy is seen to be a promising technique in metrology of microstructures. Some limitations with respect to surface metrology were found during the experiments. The experiments were carried out using a Zeiss LSM 5 Pascal microscope owned by the Danish Polymer Centre...

  11. Biological confocal microscopy

    Directory of Open Access Journals (Sweden)

    Guy Cox

    2002-04-01

    Full Text Available The first practical use of confocal optics was by Hiroto Naora1,1,2, who built a device based upon a theoretical concept devised by his supervisor Z. Koana3, over 50 years ago. His system did not form images, but was used in high resolution micro-spectrophotometry. Some 10 years later, Marvin Minsky4 added a scanning stage to construct a microscope capable of forming images. Despite these early advances, in was not until the 1970s that reasonably practical confocal microscopes were built, and the mid 1980s before commercial models became generally available.

  12. Confocal scanning microscopy

    DEFF Research Database (Denmark)

    Bariani, Paolo

    replicated topography. Confocal microscopy is seen to be a promising technique in metrology of microstructures. Some limitations with respect to surface metrology were found during the experiments. The experiments were carried out using a Zeiss LSM 5 Pascal microscope owned by the Danish Polymer Centre...

  13. Molecular confocal laser endomicroscopy

    DEFF Research Database (Denmark)

    Karstensen, John Gásdal; Klausen, Pia Helene; Saftoiu, Adrian

    2014-01-01

    While flexible endoscopy is essential for macroscopic evaluation, confocal laser endomicroscopy (CLE) has recently emerged as an endoscopic method enabling visualization at a cellular level. Two systems are currently available, one based on miniprobes that can be inserted via a conventional...

  14. Confocal laser endomicroscopy

    DEFF Research Database (Denmark)

    Karstensen, John Gásdal; Saftoiu, Adrian; Brynskov, Jørn

    2016-01-01

    Background and study aims: Confocal laser endomicroscopy (CLE) has been shown to predict relapse in ulcerative colitis in remission, but little is currently known about its role in Crohn's disease. The aim of this study was to identify reproducible CLE features in patients with Crohn's disease...

  15. Nonresonant optical control of a spinor polariton condensate

    Science.gov (United States)

    Askitopoulos, A.; Kalinin, K.; Liew, T. C. H.; Cilibrizzi, P.; Hatzopoulos, Z.; Savvidis, P. G.; Berloff, N. G.; Lagoudakis, P. G.

    2016-05-01

    We investigate the spin dynamics of polariton condensates spatially separated from and effectively confined by the pumping exciton reservoir. We obtain a strong correlation between the ellipticity of the nonresonant optical pump and the degree of circular polarization (DCP) of the condensate at the onset of condensation. With increasing excitation density we observe a reversal of the DCP. The spin dynamics of the trapped condensate are described within the framework of the spinor complex Ginzburg-Landau equations in the Josephson regime, where the dynamics of the system are reduced to a current-driven Josephson junction. We show that the observed spin reversal is due to the interplay between an internal Josephson coupling effect and the detuning of the two projections of the spinor condensate via transition from a synchronized to a desynchronized regime. These results suggest that spinor polariton condensates can be controlled by tuning the nonresonant excitation density offering applications in electrically pumped polariton spin switches.

  16. Nonresonance adiabatic photon confinement in spherical mirror system. Experimental study

    CERN Document Server

    Popov, S S; Burdakov, A V; Ushkova, M U

    2015-01-01

    New nonresonance approach of photon accumulation in two spherical mirrors has been experimentally demonstrated. In this work, we have received a high accumulation coefficient and shown good effectiveness of this technique for creating photo neutralizer of negative ion beams. This efficiency in such concept is generally determined by reflectance mirrors and is practically not dependent of input emission quality and does not require high precision adjusting the optical elements.

  17. Integration of Correlative Raman microscopy in a dual beam FIB-SEM J. of Raman Spectroscopy

    NARCIS (Netherlands)

    Timmermans, Frank Jan; Liszka, B.; Lenferink, Aufrid T.M.; van Wolferen, Hendricus A.G.M.; Otto, Cornelis

    2016-01-01

    We present an integrated confocal Raman microscope in a focused ion beam scanning electron microscope (FIB SEM). The integrated system enables correlative Raman and electron microscopic analysis combined with focused ion beam sample modification on the same sample location. This provides new

  18. Confocal Line Scanning Sensor

    Energy Technology Data Exchange (ETDEWEB)

    Chanbai, S; Wiora, G; Wewer, L [NanoFocus AG, Lindnerstr. 98, 46149 Oberhausen (Germany); Zafarullah, I [Applied Scientific Imaging Inc., Toronto (Canada); Roth, H, E-mail: chanbai@nanofocus.de, E-mail: wiora@nanofocus.de [Institute of Automatic Control Engineering, University of Siegen, Hoelderlinstr. 3, 57068 Siegen (Germany)

    2011-08-19

    We have developed a novel confocal-based imaging sensor for surface characterization. In this case, a tilted-plane technique is incorporated in a confocal imaging system to create a new parallel scanning scheme, enabling the sensor to be designed and developed as a robust and simple configuration. With a tilted disk consisting of in-line pinholes, a motionless parallel z scanning scheme is manifested when the specimen is transversely scanned through the stationary diffraction-foci projecting at different depths. This sensor uses a line scanning approach, so that it is entitled as a Confocal Line Scanning Sensor (CLSS). In this paper, the CLSS principle, the concept of data processing, and major calibration are described. The sensor was first developed as a two-dimensional profiler to cover the measurement ranges of up to 50 {mu}m in depth and up to 15 mm in lateral length. Experimental results were carried out using calibrated specimens for roughness measurement. In this system, the optical lateral resolution is 0.5 {mu}m, and the depth resolution, defined by noise-limited approach, is 15 nm.

  19. Particle manipulation by a non-resonant acoustic levitator

    Energy Technology Data Exchange (ETDEWEB)

    Andrade, Marco A. B., E-mail: marcobrizzotti@gmail.com [Institute of Physics, University of São Paulo, CP 66318, 05314-970 São Paulo (Brazil); Pérez, Nicolás [Centro Universitario de Paysandú, Universidad de la República, Ruta 3 km 363, 60000 Paysandú (Uruguay); Adamowski, Julio C. [Department of Mechatronics and Mechanical Systems Engineering, Escola Politécnica, University of São Paulo, Av. Mello Moraes, 2231, 05508-030 São Paulo (Brazil)

    2015-01-05

    We present the analysis of a non-resonant acoustic levitator, formed by an ultrasonic transducer and a concave reflector. In contrast to traditional levitators, the geometry presented herein does not require the separation distance between the transducer and the reflector to be a multiple of half wavelength. The levitator behavior is numerically predicted by applying a numerical model to calculate the acoustic pressure distribution and the Gor'kov theory to obtain the potential of the acoustic radiation force that acts on a levitated particle. We also demonstrate that levitating particles can be manipulated by controlling the reflector position while maintaining the transducer in a fixed position.

  20. Wireless energy transfer through non-resonant magnetic coupling

    DEFF Research Database (Denmark)

    Peng, Liang; Breinbjerg, Olav; Mortensen, Asger

    2010-01-01

    We demonstrate by theoretical analysis and experimental verification that mid-range wireless energy transfer systems may take advantage of de-tuned coupling devices, without jeopardizing the energy transfer efficiency. Allowing for a modest de-tuning of the source coil, energy transfer systems...... could be properly designed to minimize undesired energy dissipation in the source coil when the power receiver is out of the range. Our basic observation paves the way for more flexible design and fabrication of non-resonant mid-range wireless energy transfer systems, thus potentially impacting...... practical implementations of wireless energy transfer....

  1. Ultraviolet Resonant Raman Enhancements in the Detection of Explosives

    Energy Technology Data Exchange (ETDEWEB)

    Short Jr., Billy Joe [Naval Postgraduate School, Monterey, CA (United States)

    2009-06-01

    Raman-based spectroscopy is potentially militarily useful for standoff detection of high explosives. Normal (non-resonance) and resonance Raman spectroscopies are both light scattering techniques that use a laser to measure the vibrational spectrum of a sample. In resonance Raman, the laser is tuned to match the wavelength of a strong electronic absorbance in the molecule of interest, whereas, in normal Raman the laser is not tuned to any strong electronic absorbance bands. The selection of appropriate excitation wavelengths in resonance Raman can result in a dramatic increase in the Raman scattering efficiency of select band(s) associated with the electronic transition. Other than the excitation wavelength, however, resonance Raman is performed experimentally the same as normal Raman. In these studies, normal and resonance Raman spectral signatures of select solid high explosive (HE) samples and explosive precursors were collected at 785 nm, 244 nm and 229 nm. Solutions of PETN, TNT, and explosive precursors (DNT & PNT) in acetonitrile solvent as an internal Raman standard were quantitatively evaluated using ultraviolet resonance Raman (UVRR) microscopy and normal Raman spectroscopy as a function of power and select excitation wavelengths. Use of an internal standard allowed resonance enhancements to be estimated at 229 nm and 244 nm. Investigations demonstrated that UVRR provided ~2000-fold enhancement at 244 nm and ~800-fold improvement at 229 nm while PETN showed a maximum of ~25-fold at 244 nm and ~190-fold enhancement at 229 nm solely from resonance effects when compared to normal Raman measurements. In addition to the observed resonance enhancements, additional Raman signal enhancements are obtained with ultraviolet excitation (i.e., Raman scattering scales as !4 for measurements based on scattered photons). A model, based partly on the resonance Raman enhancement results for HE solutions, is presented for estimating Raman enhancements for solid HE samples.

  2. Noninvasive Imaging of Protein Metabolic Labeling in Single Human Cells Using Stable Isotopes and Raman Microscopy

    NARCIS (Netherlands)

    Manen, van Henk-Jan; Lenferink, Aufried; Otto, Cees

    2008-01-01

    We have combined nonresonant Raman microspectroscopy and spectral imaging with stable isotope labeling by amino acids in cell culture (SILAC) to selectively detect the incorporation of deuterium-labeled phenylalanine, tyrosine, and methionine into proteins in intact, single HeLa cells. The C−D stret

  3. Noninvasive imaging of protein metabolic labeling in single human cells using stable isotopes and Raman microscopy

    NARCIS (Netherlands)

    van Manen, H.J.; Lenferink, Aufrid T.M.; Otto, Cornelis

    2008-01-01

    We have combined nonresonant Raman microspectroscopy and spectral imaging with stable isotope labeling by amino acids in cell culture (SILAC) to selectively detect the incorporation of deuterium-labeled phenylalanine, tyrosine, and methionine into proteins in intact, single HeLa cells. The C−D

  4. Raman spectra of nitrogen-doped tetrahedral amorphous carbon from first principles

    Institute of Scientific and Technical Information of China (English)

    NIU Li; ZHU JiaQi; GAO Wei; HAN Xiao; DU ShanYi

    2009-01-01

    The non-resonant vibrational Raman spectra of nitrogen-doped tetrahedral amorphous carbon have been calculated from first principles, including the generation of s structural model, and the calculation of vibrational frequencies, vibrational eigenmodes and Raman coupling tensors. The calculated Raman spectra are in good agreement with the experimental results. The broad band at around 500 cm~(-1) arises from mixed bonds. The T peak originates from the vibrations of sp~3 carbon and the G peak comes from the stretching vibrations of sp~2-type bonding of C=C and C=N. The simulation results indicate the direct contribution of N vibrations to Raman spectra.

  5. Hyperspectral confocal microscope.

    Science.gov (United States)

    Sinclair, Michael B; Haaland, David M; Timlin, Jerilyn A; Jones, Howland D T

    2006-08-20

    We have developed a new, high performance, hyperspectral microscope for biological and other applications. For each voxel within a three-dimensional specimen, the microscope simultaneously records the emission spectrum from 500 nm to 800 nm, with better than 3 nm spectral resolution. The microscope features a fully confocal design to ensure high spatial resolution and high quality optical sectioning. Optical throughput and detection efficiency are maximized through the use of a custom prism spectrometer and a backside thinned electron multiplying charge coupled device (EMCCD) array. A custom readout mode and synchronization scheme enable 512-point spectra to be recorded at a rate of 8300 spectra per second. In addition, the EMCCD readout mode eliminates curvature and keystone artifacts that often plague spectral imaging systems. The architecture of the new microscope is described in detail, and hyperspectral images from several specimens are presented.

  6. [Confocal laser scanning microscopy].

    Science.gov (United States)

    Ulrich, M

    2015-07-01

    Reflectance confocal microscopy (RCM) allows the in vivo evaluation of melanocytic and nonmelanocytic skin tumours with high sensitivity and specificity. RCM represents an optical imaging technique, which enables us to examine the skin at high resolution. Today, RCM represents not only an interesting tool for dermatologic research but has also been introduced as a diagnostic tool in every day clinical practice. As such, RCM is applied for improvement of skin cancer diagnosis adjunct to clinical and dermatoscopic examination. In combination with dermatoscopy RCM has shown an increased specificity with similar sensitivity. In this regard RCM helps to decrease the rate of unnecessary biopsies of benign lesions. Despite its use in dermatooncology RCM may also be used for diagnosis and monitoring of inflammatory diseases. Future developments include technical improvements, teledermatology solutions and the application of ex vivo RCM in Moh's micrographic surgery.

  7. Confocal microscopy of colloids

    Energy Technology Data Exchange (ETDEWEB)

    Prasad, V; Semwogerere, D; Weeks, Eric R [Department of Physics, Emory University, Atlanta, GA 30322 (United States)

    2007-03-21

    Colloids have increasingly been used to characterize or mimic many aspects of atomic and molecular systems. With confocal microscopy these colloidal particles can be tracked spatially in three dimensions with great precision over large time scales. This review discusses equilibrium phases such as crystals and liquids, and non-equilibrium phases such as glasses and gels. The phases that form depend strongly on the type of particle interaction that dominates. Hard-sphere-like colloids are the simplest, and interactions such as the attractive depletion force and electrostatic repulsion result in more non-trivial phases which can better model molecular materials. Furthermore, shearing or otherwise externally forcing these colloids while under microscopic observation helps connect the microscopic particle dynamics to the macroscopic flow behaviour. Finally, directions of future research in this field are discussed. (topical review)

  8. Confocal coded aperture imaging

    Energy Technology Data Exchange (ETDEWEB)

    Tobin, Jr., Kenneth William (Harriman, TN); Thomas, Jr., Clarence E. (Knoxville, TN)

    2001-01-01

    A method for imaging a target volume comprises the steps of: radiating a small bandwidth of energy toward the target volume; focusing the small bandwidth of energy into a beam; moving the target volume through a plurality of positions within the focused beam; collecting a beam of energy scattered from the target volume with a non-diffractive confocal coded aperture; generating a shadow image of said aperture from every point source of radiation in the target volume; and, reconstructing the shadow image into a 3-dimensional image of the every point source by mathematically correlating the shadow image with a digital or analog version of the coded aperture. The method can comprise the step of collecting the beam of energy scattered from the target volume with a Fresnel zone plate.

  9. Nonadiabatic level crossing in resonant and nonresonant neutrino oscillations

    CERN Document Server

    Kachelriess, M

    2001-01-01

    We study neutrino oscillations and the level-crossing probability PLSZ = exp(–gamman[script F]npi/2) (LSZ stands for Landau-Stückelberg-Zener) in power-law-like potential profiles A(r)[proportional]rn. After showing that the resonance point coincides only for a linear profile with the point of maximal violation of adiabaticity, we point out that the "adiabaticity" parameter gamman can be calculated at an arbitrary point if the correction function [script F]n is rescaled appropriately. We present a new representation for the level-crossing probability, PLSZ = exp(–kappan[script G]n), which allows a simple numerical evaluation of PLSZ in both the resonant and nonresonant cases, and where [script G]n contains the full dependence of PLSZ on the mixing angle theta. As an application we consider the case n = –3 important for oscillations of supernova neutrinos.

  10. Enhancement of non-resonant dielectric cloaks using anisotropic composites

    CERN Document Server

    Takezawa, Akihiro

    2014-01-01

    The effectiveness of homogenized anisotropic materials in non-resonant dielectric multilayer cloaking is studied. Because existing multilayer cloaking by isotropic materials can be regarded as homogenous anisotropic cloaking from a macroscopic view, they can be efficiently designed by handling the physical properties of anisotropic materials directly. Anisotropic properties can be realized in two-phase composites if the physical properties of the material are within appropriate bounds. The optimized anisotropic physical properties are identified by a numerical optimization technique based on a full-wave simulation using the finite element method. The cloaking performance measured by the total scattering width is improved by about 10% compared with existing multilayer cloaking by isotropic materials in eight-layer cylindrical cloaking materials. The same performance with eight-layer cloaking by isotropic materials is achieved by three-layer cloaking using anisotropic materials. Cloaking with a about 50% reduct...

  11. Global nonresonant vibrational-photoelectron coupling in molecular photoionization

    Science.gov (United States)

    Poliakoff, Erwin; Das, Aloke; Hardy, David; Bozek, John; Aguilar, Alex; Lucchese, Robert

    2009-05-01

    Using photoelectron spectroscopy and Schwinger variational scattering theory, we have investigated the coupling between vibrational motion and the exiting photoelectron over extended ranges of photoelectron kinetic energy. Photoelectron spectroscopy is performed with vibrational resolution over uncommonly large ranges of energy (ca. 200 eV). We find clear and significant changes in vibrational branching ratios as a function of photon energy, in direct contradiction to predictions of the Franck-Condon principle. While it is well known that resonances lead to coupling between electronic and vibrational degrees of freedom, nonresonant mechanisms that result in such coupling are not expected or well-documented. Photoelectron spectra are presented for several electronic states of N2^+, CO^+, and NO^+, and we find that valence isoelectronic channels behave very differently, which is also surprising. Theoretical results indicate that Cooper minima are the underlying cause of these effects, and we are currently working to understand the reasons for the sensitivity of the Cooper minima on bond length.

  12. Broadband metamaterial for nonresonant matching of acoustic waves.

    Science.gov (United States)

    D'Aguanno, G; Le, K Q; Trimm, R; Alù, A; Mattiucci, N; Mathias, A D; Aközbek, N; Bloemer, M J

    2012-01-01

    Unity transmittance at an interface between bulk media is quite common for polarized electromagnetic waves incident at the Brewster angle, but it is rarely observed for sound waves at any angle of incidence. In the following, we theoretically and experimentally demonstrate an acoustic metamaterial possessing a Brewster-like angle that is completely transparent to sound waves over an ultra-broadband frequency range with >100% bandwidth. The metamaterial, consisting of a hard metal with subwavelength apertures, provides a surface impedance matching mechanism that can be arbitrarily tailored to specific media. The nonresonant nature of the impedance matching effectively decouples the front and back surfaces of the metamaterial allowing one to independently tailor the acoustic impedance at each interface. On the contrary, traditional methods for acoustic impedance matching, for example in medical imaging, rely on resonant tunneling through a thin antireflection layer, which is inherently narrowband and angle specific.

  13. Confocal microscopy and exfoliative cytology.

    Science.gov (United States)

    Reddy, Shyam Prasad; Ramani, Pratibha; Nainani, Purshotam

    2013-05-01

    Early detection of potentially malignant lesions and invasive squamous-cell carcinoma in the oral cavity could be greatly improved through techniques that permit visualization of subtle cellular changes indicative of the neoplastic transformation process. One such technique is confocal microscopy. Combining rapidity with reliability, an innovative idea has been put forward using confocal microscope in exfoliative cytology. The main objective of this study was to assess confocal microscopy for cytological diagnosis and the results were compared with that of the standard PAP stain. Confocal microscope, acridine orange (AO) stain, PAP (Papanicolaou) stain. The study was designed to assess confocal microscopy for cytological diagnosis. In the process, smears of patients with (clinically diagnosed and/or suspected) oral squamous cell carcinoma as well as those of controls (normal people) were stained with acridine orange and observed under confocal microscope. The results were compared with those of the standard PAP method. Samples of buccal mucosa smears from normal patients and squamous cell carcinoma patients were made, fixed in 100% alcohol, followed by AO staining. The corresponding set of smears was stained with PAP stain using rapid PAP stain kit. The results obtained were compared with those obtained with AO confocal microscopy. The study had shown nuclear changes (malignant cells) in the smears of squamous cell carcinoma patients as increased intensity of fluorescence of the nucleus, when observed under confocal microscope. Acridine orange confocal microscopy showed good amount of sensitivity and specificity (93%) in identifying malignant cells in exfoliative cytological smears. Confocal microscopy was found to have good sensitivity in the identification of cancer (malignant) cells in exfoliative cytology, at par with the PAP method. The rapidity of processing and screening a specimen resulted in saving of time. It added a certain amount of objectivity to the

  14. Confocal microscopy and exfoliative cytology

    Directory of Open Access Journals (Sweden)

    Shyam Prasad Reddy

    2013-01-01

    Full Text Available Context: Early detection of potentially malignant lesions and invasive squamous-cell carcinoma in the oral cavity could be greatly improved through techniques that permit visualization of subtle cellular changes indicative of the neoplastic transformation process. One such technique is confocal microscopy. Combining rapidity with reliability, an innovative idea has been put forward using confocal microscope in exfoliative cytology. Aims: The main objective of this study was to assess confocal microscopy for cytological diagnosis and the results were compared with that of the standard PAP stain. Settings and Design: Confocal microscope, acridine orange (AO stain, PAP (Papanicolaou stain. The study was designed to assess confocal microscopy for cytological diagnosis. In the process, smears of patients with (clinically diagnosed and/or suspected oral squamous cell carcinoma as well as those of controls (normal people were stained with acridine orange and observed under confocal microscope. The results were compared with those of the standard PAP method. Materials and Methods: Samples of buccal mucosa smears from normal patients and squamous cell carcinoma patients were made, fixed in 100% alcohol, followed by AO staining. The corresponding set of smears was stained with PAP stain using rapid PAP stain kit. The results obtained were compared with those obtained with AO confocal microscopy. Results: The study had shown nuclear changes (malignant cells in the smears of squamous cell carcinoma patients as increased intensity of fluorescence of the nucleus, when observed under confocal microscope. Acridine orange confocal microscopy showed good amount of sensitivity and specificity (93% in identifying malignant cells in exfoliative cytological smears. Conclusion: Confocal microscopy was found to have good sensitivity in the identification of cancer (malignant cells in exfoliative cytology, at par with the PAP method. The rapidity of processing and

  15. Rapid quantitative analysis of Dimethoate pesticide using surface enhanced raman spectroscopy

    Science.gov (United States)

    A method for rapid quantitative detection of dimethoate pesticide by using surface-enhanced Raman spectroscopy (SERS) has been described. Significantly enhanced Raman signals of pesticide in low concentrations of 0.5 ~ 10 ug/mL were acquired by confocal raman micro-spectrometry with renishaw diagno...

  16. Raman spectroscopy

    Science.gov (United States)

    Raman spectroscopy has gained increased use and importance in recent years for accurate and precise detection of physical and chemical properties of food materials, due to the greater specificity and sensitivity of Raman techniques over other analytical techniques. This book chapter presents Raman s...

  17. The use of laser scanning confocal microscopy (LSCM) in materials science.

    Science.gov (United States)

    Hovis, D B; Heuer, A H

    2010-12-01

    Laser scanning confocal microscopes are essential and ubiquitous tools in the biological, biochemical and biomedical sciences, and play a similar role to scanning electron microscopes in materials science. However, modern laser scanning confocal microscopes have a number of advantages for the study of materials, in addition to their obvious uses for high resolution reflected and transmitted light optical microscopy. In this paper, we provide several examples that exploit the laser scanning confocal microscope's capabilities of pseudo-infinite depth of field imaging, topographic imaging, photo-stimulated luminescence imaging and Raman spectroscopic imaging. © 2010 The Authors Journal of Microscopy © 2010 The Royal Microscopical Society.

  18. The attosecond regime of impulsive stimulated electronic Raman excitation

    CERN Document Server

    Ware, Matthew R; Cryan, James P; Haxton, Daniel J

    2016-01-01

    We have calculated the resonant and nonresonant contributions to attosecond impulsive stimulated electronic Raman scattering (SERS) in regions of autoionizing transitions. Comparison with Multiconfiguration Time-Dependent Hartree-Fock (MCTDHF) calculations find that attosecond SERS is dominated by continuum transitions and not autoionizing resonances. These results agree quantitatively with a rate equation that includes second-order Raman and first-and second-order photoionization rates. Such rate models can be extended to larger molecular systems. Our results indicate that attosecond SERS transition probabilities may be understood in terms of two-photon generalized cross sections even in the high-intensity limit for extreme ultraviolet wavelengths.

  19. Electromagnetically induced transparency in an asymmetric double quantum well under non-resonant, intense laser fields

    Science.gov (United States)

    Niculescu, E. C.

    2017-02-01

    Electromagnetically induced transparency in an asymmetric double quantum well subjected to a non-resonant, intense laser field is theoretically investigated. We found that the energy levels configuration could be switched between a Λ-type and a ladder-type scheme by varying the non-resonant radiation intensity. This effect is due to the laser-induced electron tunneling between the wells and it allows a substantial flexibility in the manipulation of the optical properties. The dependence of the susceptibilities on the control field Rabi frequency, intensity of the nonresonant laser, and the control field detuning for both configurations are discussed and compared.

  20. High-Speed Coherent Raman Fingerprint Imaging of Biological Tissues

    CERN Document Server

    Camp, Charles H; Heddleston, John M; Hartshorn, Christopher M; Walker, Angela R Hight; Rich, Jeremy N; Lathia, Justin D; Cicerone, Marcus T

    2014-01-01

    We have developed a coherent Raman imaging platform using broadband coherent anti-Stokes Raman scattering (BCARS) that provides an unprecedented combination of speed, sensitivity, and spectral breadth. The system utilizes a unique configuration of laser sources that probes the Raman spectrum over 3,000 cm$^{-1}$ and generates an especially strong response in the typically weak Raman "fingerprint" region through heterodyne amplification of the anti-Stokes photons with a large nonresonant background (NRB) while maintaining high spectral resolution of $<$ 13 cm$^{-1}$. For histology and pathology, this system shows promise in highlighting major tissue components in a non-destructive, label-free manner. We demonstrate high-speed chemical imaging in two- and three-dimensional views of healthy murine liver and pancreas tissues and interfaces between xenograft brain tumors and the surrounding healthy brain matter.

  1. Soliton models in resonant and nonresonant optical fibers

    Indian Academy of Sciences (India)

    K Porsezian

    2001-11-01

    In this review, considering the important linear and nonlinear optical effects like group velocity dispersion, higher order dispersion, Kerr nonlinearity, self-steepening, stimulated Raman scattering, birefringence, self-induced transparency and various inhomogeneous effects in fibers, the completely integrable concept and bright, dark and self-induced transparency soliton models in nonlinear fiber optics are discussed. Considering the above important optical effects, the different completely integrable soliton models in the form of nonlinear Schrödinger (NLS), NLS-MaxwellBloch (MB) type equations reported in the literature are discussed. Finally, solitons in stimulated Raman scattering (SRS) system is briefly discussed.

  2. Rapid identification of Candida species by confocal Raman microspectroscopy

    NARCIS (Netherlands)

    K. Maquelin (Kees); L.P. Choo-Smith; H.P. Endtz (Hubert); H.A. Bruining (Hajo); G.J. Puppels (Gerwin)

    2002-01-01

    textabstractCandida species are important nosocomial pathogens associated with high mortality rates. Rapid detection and identification of Candida species can guide a clinician at an early stage to prescribe antifungal drugs or to adjust empirical therapy when resistant species are

  3. Confocal Raman Microspectroscopy : Applications in Cartilage Tissue Engineering

    NARCIS (Netherlands)

    Kunstar, A.

    2012-01-01

    Weefseltechniek, ofwel ‘tissue engineering’, van kraakbeen behelst het gebruik van driedimensionale dragermaterialen (‘scaffolds’) in combinatie met primaire chondrocyten of gedifferentieerde mesenchymale stamcellen om een bio-artificieel construct te creëren voor klinische toepassing. Over het alge

  4. In vivo skin characterization by confocal Raman microspectroscopy

    NARCIS (Netherlands)

    P.J. Caspers (Peter)

    2003-01-01

    markdownabstract__Abstract__ Various areas of skin research depend on detailed knowledge of the molecular composition of skin and molecular structure of skin constituents. On a microscopic scale the skin is a highly heterogeneous tissue. Molecular composition and structure vary

  5. A note on a nonresonance condition at zero for first-order planar systems

    Directory of Open Access Journals (Sweden)

    Maurizio Garrione

    2015-01-01

    Full Text Available We introduce a Landesman-Lazer type nonresonance condition at zero for planar systems and discuss its rotational interpretation. We then show an application concerning multiplicity of T-periodic solutions to unforced Hamiltonian systems like $$ Ju'=\

  6. Characterization of the non-resonant radiation damping in coupled cavity photon magnon system

    Science.gov (United States)

    Rao, J. W.; Kaur, S.; Fan, X. L.; Xue, D. S.; Yao, B. M.; Gui, Y. S.; Hu, C.-M.

    2017-06-01

    We have experimentally investigated the non-resonant radiation damping in the coupled cavity photon-magnon system in addition to the resonant radiation damping which results in the linewidth exchange between the magnon-like and photon-like hybrid modes. The contribution of this non-resonant effect becomes apparent when the cavity photon-magnon resonance frequencies are mismatched. By carefully examining the change in the linewidth and the shift in the magnon resonance as a function of the coupling strength between the cavity photons and magnons, we can quantitatively describe this non-resonant radiation damping by including an additional relaxation channel for the hybridized photon-magnon system. This experimental realization and theoretical modelling of the non-resonant radiation damping in the cavity photon-magnon system may help in the design and adaptation of these systems for practical applications.

  7. Raman facility

    Data.gov (United States)

    Federal Laboratory Consortium — Raman scattering is a powerful light scattering technique used to diagnose the internal structure of molecules and crystals. In a light scattering experiment, light...

  8. Controlling a diatomic shape resonance with non-resonant light

    CERN Document Server

    Aganoglu, Ruzin; Friedrich, Bretislav; González-Férez, Rosario; Koch, Christiane P

    2011-01-01

    A (diatomic) shape resonance is a metastable state of a pair of colliding atoms quasi-bound by the centrifugal barrier imposed by the angular momentum involved in the collision. The temporary trapping of the atoms' scattering wavefunction corresponds to an enhanced atom pair density at low interatomic separations. This leads to larger overlap of the wavefunctions involved in a molecule formation process such as photoassociation, rendering the process more efficient. However, for an ensemble of atoms, the atom pair density will only be enhanced if the energy of the resonance comes close to the temperature of the atomic ensemble. Herein we explore the possibility of controlling the energy of a shape resonance by shifting it toward the temperature of atoms confined in a trap. The shifts are imparted by the interaction of non-resonant light with the anisotropic polarizability of the atom pair, which affects both the centrifugal barrier and the pair's rotational and vibrational levels. We find that at laser intens...

  9. Fluid simulations of non-resonant anisotropic ion heating

    Directory of Open Access Journals (Sweden)

    D. Laveder

    2013-07-01

    Full Text Available The finite Larmor radius (FLR-Landau fluid model, which extends the usual anisotropic magnetohydrodynamics to magnetized collisionless plasmas by retaining linear Landau damping and finite Larmor radius corrections down to the sub-ionic scales in the quasi-transverse directions, is used to study the non-resonant heating of the plasma by randomly driven Alfvén waves. One-dimensional numerical simulations, free from any artificial dissipation, are used to analyze the influence on the thermal dynamics, of the beta parameter and of the separation between the driving and the ion scales. While the gyrotropic heat fluxes play a dominant role when the plasma is driven at large scales, leading to a parallel heating of the ions by Landau damping, a different regime develops when the driving acts at scales comparable to the ion Larmor radius. Perpendicular heating and parallel cooling of the ions are then observed, an effect that is mostly due to the work of the non-gyrotropic pressure force and that can be viewed as the fluid signature of the so-called stochastic heating. A partial characterization of the plasma by global quantities (such as the magnetic compressibility and the density-magnetic field correlations that provide information on the dominant type of waves is also presented. The enhancement of the parallel electron heating by a higher level of fast magnetosonic waves is in particular pointed out.

  10. Polarized multiplex coherent anti-Stokes Raman scattering using a picosecond laser and a fiber supercontinuum.

    Science.gov (United States)

    Michel, Sébastien; Courjaud, Antoine; Mottay, Eric; Finot, Christophe; Dudley, John; Rigneault, Hervé

    2011-02-01

    We perform multiplex coherent anti-Stokes Raman scattering (CARS) micro-spectroscopy with a picosecond pulsed laser and a broadband supercontinuum (SC) generated in photonic crystal fiber. CARS signal stability is achieved using an active fiber coupler that avoids thermal and mechanical drifts. We obtain multiplex CARS spectra for test liquids in the 600-2000 cm(-1) spectral range. In addition we investigate the polarization dependence of the CARS spectra when rotating the pump beam linear polarization state relative to the linearly polarized broad stokes SC. From these polarization measurements we deduce the Raman depolarization ratio, the resonant versus nonresonant contribution, the Raman resonance frequency, and the linewidth.

  11. Spatial resolution of tip-enhanced Raman spectroscopy - DFT assessment of the chemical effect.

    Science.gov (United States)

    Latorre, Federico; Kupfer, Stephan; Bocklitz, Thomas; Kinzel, Daniel; Trautmann, Steffen; Gräfe, Stefanie; Deckert, Volker

    2016-05-21

    Experimental evidence of extremely high spatial resolution of tip-enhanced Raman scattering (TERS) has been recently demonstrated. Here, we present a full quantum chemical description (at the density functional level of theory) of the non-resonant chemical effects on the Raman spectrum of an adenine molecule mapped by a tip, modeled as a single silver atom or a small silver cluster. We show pronounced changes in the Raman pattern and its intensities depending on the conformation of the nanoparticle-substrate system, concluding that the spatial resolution of the chemical contribution of TERS can be in the sub-nm range.

  12. Cavity-enhanced Raman Microscopy of Individual Carbon Nanotubes

    CERN Document Server

    Hümmer, Thomas; Hofmann, Matthias S; Hänsch, Theodor W; Högele, Alexander; Hunger, David

    2015-01-01

    Raman spectroscopy reveals chemically specific information, and combined with imaging provides label-free insight into the molecular world. However, the signals are intrinsically weak and call for enhancement techniques. Here we use a tunable high-finesse optical microcavity to demonstrate Purcell enhancement of Raman scattering in combination with high-resolution scanning-cavity imaging. We detect cavity-enhanced Raman spectra of individual single-walled carbon nanotubes, expand the technique to hyperspectral imaging, and co-localize measurements with cavity-enhanced absorption microscopy. Direct comparison with confocal Raman microscopy yields a 550-times enhanced collectable Raman scattering spectral density and a 11-fold enhancement of the integrated count rate. The quantitative character, the inherent spectral filtering, and the absence of intrinsic background in cavity-vacuum stimulated Raman scattering renders our technique a promising tool for molecular imaging. Furthermore, cavity-enhanced Raman tran...

  13. Twin-Photon Confocal Microscopy

    CERN Document Server

    Simon, D S

    2010-01-01

    A recently introduced two-channel confocal microscope with correlated detection promises up to 50% improvement in transverse spatial resolution [Simon, Sergienko, Optics Express {\\bf 18}, 9765 (2010)]. Here we move further by introducing a triple-confocal correlated microscope, exploiting the correlations present in optical parametric amplifiers. It is based on tight focusing of pump radiation onto a thin sample positioned in front of a nonlinear crystal, followed by coincidence detection of signal and idler photons, each focused onto a pinhole. This approach offers further resolution enhancement in microscopy.

  14. CONFOCAL MICROSCOPY SYSTEM PERFORMANCE: SPECTROSCOPY

    Science.gov (United States)

    The confocal laser-scanning microscope (CLSM) has enormous potential in many biological fields. The goal of a CLSM is to acquire and quantify fluorescence and in some instruments acquire spectral characterization of emitted signals. The accuracy of these measurements demands that...

  15. Raman imaging of biofilms using gold sputtered fiber optic probes

    Science.gov (United States)

    Christopher, Christina Grace Charlet; Manoharan, Hariharan; Subrahmanyam, Aryasomayajula; Sai, V. V. Raghavendra

    2016-12-01

    In this work we report characterization of bacterial biofilm using gold sputtered optical fiber probe as substrates for confocal Raman spectroscopy measurements. The chemical composition and the heterogeneity of biofilms in the extracellular polymeric substances (EPS) was evaluated. The spatial distribution of bacterial biofilm on the substrates during their growth phase was studied using Raman imaging. Further, the influence of substrate's surface on bacterial adhesion was investigated by studying growth of biofilms on surfaces with hydrophilic and hydrophobic coatings. This study validates the use of gold sputtered optical fiber probes as SERS substrates in confocal microscopic configuration to identify and characterize clinically relevant biofilms.

  16. Quantum three-body calculation of the nonresonant triple-\\alpha reaction rate at low temperatures

    CERN Document Server

    Ogata, Kazuyuki; Kamimura, Masayasu

    2009-01-01

    The triple-\\alpha reaction rate is re-evaluated by directly solving the three-body Schroedinger equation. The resonant and nonresonant processes are treated on the same footing using the continuum-discretized coupled-channels method for three-body scattering. Accurate description of the \\alpha-\\alpha nonresonant states significantly quenches the Coulomb barrier between the two-\\alpha's and the third \\alpha particle. Consequently, the \\alpha-\\alpha nonresonant continuum states below the resonance at 92.04 keV, i.e., the ground state of 8Be, give markedly larger contribution at low temperatures than in foregoing studies. We find about 20 orders-of-magnitude enhancement of the triple-\\alpha reaction rate around 10^7 K compared to the rate of the NACRE compilation.

  17. Non-resonant wave front reversal of spin waves used for microwave signal processing

    Energy Technology Data Exchange (ETDEWEB)

    Vasyuchka, V I; Chumak, A V; Hillebrands, B [Fachbereich Physik and Forschungszentrum OPTIMAS, Technische Universitaet Kaiserslautern, 67663 Kaiserslautern (Germany); Melkov, G A; Moiseienko, V A [Department of Radiophysics, National Taras Shevchenko University of Kiev, 01033 Kiev (Ukraine); Slavin, A N, E-mail: vasyuchka@physik.uni-kl.d [Department of Physics, Oakland University, Rochester, MI 48309 (United States)

    2010-08-18

    It is demonstrated that non-resonant ({omega}{sub s} {ne} {omega}{sub p}/2) wave front reversal (WFR) of spin-wave pulses (carrier frequency {omega}{sub s}) caused by pulsed parametric pumping (carrier frequency {omega}{sub p}) can be effectively used for microwave signal processing. When the spectral width {Omega}{sub s} of the signal is wider than the frequency band {Omega}{sub p} of signal amplification by pumping ({Omega}{sub s} >> {Omega}{sub p}), the non-resonant WFR can be used for the analysis of the signal spectrum. In the opposite case ({Omega}{sub s} << {Omega}{sub p}) the non-resonant WFR can be used for active (with amplification) filtering of the input signal.

  18. Highly selective population of two excited states in nonresonant two-photon absorption

    Institute of Scientific and Technical Information of China (English)

    Zhang Hui; Zhang Shi-An; Sun Zhen-Rong

    2011-01-01

    A nonresonant two-photon absorption process can be manipulated by tailoring the ultra-short laser pulse.In this paper,we theoretically demonstrate a highly selective population of two excited states in the nonresonant two-photon absorption process by rationally designing a spectral phase distribution.Our results show that one excited state is maximally populated while the other state population is widely tunable from zero to the maximum value.We believe that the theoretical results may play an important role in the selective population of a more complex nonlinear process comprising nonresonant two-photon absorption,such as resonance-mediated(2+1)-three-photon absorption and (2+1)-resonant multiphoton ionization.

  19. Quantitative interpretation of time-resolved coherent anti-Stokes Raman spectroscopy with all Gaussian pulses

    CERN Document Server

    Ariunbold, Gombojav O

    2016-01-01

    Coherent Raman scattering spectroscopy is studied purposely, with the Gaussian ultrashort pulses as a hands-on elucidatory extraction tool of the clean coherent Raman resonant spectra from the overall measured data contaminated with the non-resonant four wave mixing background. The integral formulae for both the coherent anti-Stokes and Stokes Raman scattering are given in the semiclassical picture, and the closed-form solutions in terms of a complex error function are obtained. An analytic form of maximum enhancement of pure coherent Raman spectra at threshold time delay depending on bandwidth of probe pulse is also obtained. The observed experimental data for pyridine in liquid-phase are quantitatively elucidated and the inferred time-resolved coherent Raman resonant results are reconstructed with a new insight.

  20. Femtosecond Raman induced polarization spectroscopy studies of coherent rotational dynamics in molecular fluids

    Energy Technology Data Exchange (ETDEWEB)

    Morgen, Michael Mark [Univ. of California, Berkeley, CA (United States). Dept. of Chemistry

    1997-05-01

    We develop a polarization-sensitive femtosecond pump probe technique, Raman induced polarization spectroscopy (RIPS), to study coherent rotation in molecular fluids. By observing the collisional dephasing of the coherently prepared rotational states, we are able to extract information concerning the effects of molecular interactions on the rotational motion. The technique is quite sensitive because of the zero background detection method, and is also versatile due to its nonresonant nature.

  1. Quantum effets in nonresonant X-ray scattering

    Energy Technology Data Exchange (ETDEWEB)

    Slowik, Jan Malte

    2015-11-15

    Due to their versatile properties, X rays are a unique tool to investigate the structure and dynamics of matter. X-ray scattering is the fundamental principle of many imaging techniques. Examples are X-ray crystallography, which recently celebrated one hundred years and is currently the leading method in structure determination of proteins, as well as X-ray phase contrast imaging (PCI), which is an imaging technique with countless applications in biology, medicine, etc. The technological development of X-ray free electron lasers (XFEL) has brought X-ray imaging at the edge of a new scientific revolution. XFELs offer ultrashort X-ray pulses with unprecedented high X-ray fluence and excellent spatial coherence properties. These properties make them an outstanding radiation source for X-ray scattering experiments, providing ultrafast temporal resolution as well as atomic spatial resolution. However, the radiation-matter interaction in XFEL experiments also advances into a novel regime. This demands a sound theoretical fundament to describe and explore the new experimental possibilities. This dissertation is dedicated to the theoretical study of nonresonant X-ray scattering. As the first topic, I consider the near-field imaging by propagation based X-ray phase contrast imaging (PCI). I devise a novel theory of PCI, in which radiation and matter are quantized. Remarkably, the crucial interference term automatically excludes contributions from inelastic scattering. This explains the success of the classical description thus far. The second topic of the thesis is the X-ray imaging of coherent electronic motion, where quantum effects become particularly apparent. The electron density of coherent electronic wave packets - important in charge transfer and bond breaking - varies in time, typically on femto- or attosecond time scales. In the near future, XFELs are envisaged to provide attosecond X-ray pulses, opening the possibility for time-resolved ultrafast X-ray scattering

  2. Raman spectroscopy application in frozen carrot cooked in different ways and the relationship with carotenoids

    NARCIS (Netherlands)

    Camorani, Paolo; Chiavaro, Emma; Cristofolini, Luigi; Paciulli, Maria; Zaupa, Maria; Visconti, Attilio; Fogliano, Vincenzo; Pellegrini, Nicoletta

    2015-01-01

    BACKGROUND: Raman spectroscopy, in its confocal micro-Raman variation, has been recently proposed as a spatially resolved method to identify carotenoids in various food matrices, being faster, non-destructive, and avoiding sample extraction, but no data are present in the literature concerning it

  3. Non-resonant parametric amplification in biomimetic hair flow sensors: Selective gain and tunable filtering

    NARCIS (Netherlands)

    Droogendijk, H.; Bruinink, C.M.; Sanders, Remco G.P.; Krijnen, Gijsbertus J.M.

    2011-01-01

    We demonstrate that the responsivity of flow sensors for harmonic flows can be improved significantly by non-resonant parametric amplification. Using electrostatic spring softening by AC-bias voltages, increased responsivity and sharp filtering are achieved in our biomimetic flow sensors. Tunable

  4. Evaluation of Effective Astrophysical S factor for Non-Resonant Reactions

    CERN Document Server

    Ueda, M; Pato, M P; Hussein, M S

    2003-01-01

    We derived analytic formulas of the effective S astrophysical S factor,S^eff for a non-resonant reaction of charged particles using a Taylor expension of the astrophysical S factor and a uniform approximation.The formulas will be able to generate generate more accurate approximation to S^eff than previous ones.

  5. MicroRaman Spectroscopy and Raman Imaging of Basal Cell Carcinoma

    Science.gov (United States)

    Short, M. A.; Zeng, H.; Lui, H.

    2005-03-01

    We have measured the Raman spectra of normal and cancerous skin tissues using a confocal microRaman spectrograph with a sub-micron spatial resolution. We found that the Raman spectrum of a cell nucleolus is different from the spectra measured outside the nucleolus and considerably different from those measured outside the nucleus. In addition, we found significant spectroscopic differences between normal and cancer-bearing sites in the dermis region. In order to utilize these differences for non-invasive skin cancer diagnosis, we have developed a Raman imaging system that clearly demonstrates the structure, location and distribution of cells in unstained skin biopsy samples. Our method is expected to be useful for the detection and characterization of skin cancer based on the known distinct cellular differences between normal and malignant skin.

  6. Counter-Propagating Coherent Stimulated Raman Spectroscopy for Remote Sensing in Air

    Science.gov (United States)

    Yuan, Luqi; Traverso, Andrew; Voronine, Dmitri; Jha, Pankaj; Wang, Kai; Sokolov, Alexei; Scully, Marlan

    2011-03-01

    We analyze phase-matching conditions in various four-wave mixing schemes for coherent nonlinear optical spectroscopy in the counter-propagating beam configuration. Coherent stimulated Raman spectroscopy satisfies the conditions and gives a signal containing specific molecular spectroscopic information. A counter-propagating broadband and a narrowband pulses are used to measure the Raman spectrum with a single shot. In addition, the nonresonant background due to the nondegenerate four-wave mixing is suppressed. Using this technique we develop a new scheme for standoff spectroscopy in atmosphere by using nitrogen molecules in air as a gain medium for remote lasing.

  7. Acquisition of a Modular, Multi-laser, Raman-AFM Instrument for Multdisciplinary Research

    Science.gov (United States)

    2015-04-28

    Acquisition of a Modular, Multi-laser, Raman- AFM Instrument for Multdisciplinary Research A four-laser, confocal Raman/Atomic Force Scanning...microscope (Raman- AFM ) (priced at ~ $496,000) has been acquired From Horiba Scientific. Acquisition of this instrument has enhanced the research and...capabilities as well as provides high resolution topographical and depth imaging capabilities through the AFM . The views, opinions and/or findings

  8. Confocal MXRF in environmental applications

    Energy Technology Data Exchange (ETDEWEB)

    Fittschen, Ursula Elisabeth Adriane [University of Hamburg, Department of Chemistry, Hamburg (Germany); Falkenberg, Gerald [Deutsches Elektronen Synchrotron, Hamburg (Germany)

    2011-06-15

    In this review we highlight the performance of confocal micro X-ray fluorescence (CMXRF) for application in environmental science, citing contributions from recent studies (2008-2010). In CMXRF the use of focusing and collecting optics enables discrimination of the origin of fluorescence photons in three dimensions. It thereby enables simple and direct three dimensional imaging, and also the removal of unwanted signal contribution either from the depth of the sample or from its surface. By limiting the area of origin of fluorescence signal CMXRF can simplify quantitative approaches. (orig.)

  9. Raman hyperspectral imaging and analysis of fat spreads

    NARCIS (Netherlands)

    Dalen, van G.; Velzen, van E.J.J.; Heussen, P.C.M.; Sovago, M.; Malssen, van K.F.; Duynhoven, van J.P.M.

    2017-01-01

    The microstructure of fat spreads is of fundamental importance to their sensorial properties such as texture, mouthfeel and spreadability. Fat spreads are water in oil emulsions,with a continuous phase supported by a fat crystal network. Confocal Raman microscopy offers the possibility for the

  10. Micro-Raman spectroscopy of single leukemic cells

    Institute of Scientific and Technical Information of China (English)

    Changmei Cai; Rong Chen; Juqiang Lin; Yongzeng Li; Shangyuan Feng

    2008-01-01

    The Raman spectra from leukemic cell line (HL60) and normal human peripheral blood mononuclear cells (PBMCs) are obtained by confocal micro-Raman spectroscopy using near-infrared laser (785 nm) excitation. The scanning range is from 500 to 2000 cm-1. The two average Raman spectra of normal PBMCs and carcinoma cells have clear differences because their structure and amount of nucleic acid, protein, and other major molecules are changed. The spectra are also compared and analyzed by principal component analysis (PCA) to demonstrate the two distinct clusters of normal and transformed cells. The sensitivity of this technique for identifying transformed cells is 100%.

  11. Raman Spectra Of Double-Walled Carbon Nanotubes

    Science.gov (United States)

    Vuković, T.; Dmitrović, S.; Dobardžić, E.

    2007-04-01

    Using nonresonant bond-polarization theory, Raman spectra of periodic double-walled carbon nanotubes (DWCNTs) are calculated. Due to the lower symmetry of DWCNT, the number of Raman active modes is much larger compared to those of its layers. Complete frequency range of the tubes spectra has been analyzed for large number of tubes. We found that only modes whose frequencies are below 800 cm-1 have noticeable up shifts compared to those of isolated layers. Special attention is given to radial breathing modes (RBMs) and G-band region since these modes are used for the identification of singe-walled carbon nanotubes. In case of breathing like modes (BLMs), frequency of the out of phase mode is found to be chirality dependent, while the in phase one remains only diameter dependent as in the case of individual layers.

  12. Confocal imaging of butterfly tissue.

    Science.gov (United States)

    Brunetti, Craig R

    2014-01-01

    To understand the molecular events responsible for morphological change requires the ability to examine gene expression in a wide range of organisms in addition to model systems to determine how the differences in gene expression correlate with phenotypic differences. There are approximately 12,000 species of butterflies, most, with distinct patterns on their wings. The most important tool for studying gene expression in butterflies is confocal imaging of butterfly tissue by indirect immunofluorescence using either cross-reactive antibodies from closely related species such as Drosophila or developing butterfly-specific antibodies. In this report, we describe how indirect immunofluorescence protocols can be used to visualize protein expression patterns on the butterfly wing imaginal disc and butterfly embryo.

  13. QUANTITATIVE CONFOCAL LASER SCANNING MICROSCOPY

    Directory of Open Access Journals (Sweden)

    Merete Krog Raarup

    2011-05-01

    Full Text Available This paper discusses recent advances in confocal laser scanning microscopy (CLSM for imaging of 3D structure as well as quantitative characterization of biomolecular interactions and diffusion behaviour by means of one- and two-photon excitation. The use of CLSM for improved stereological length estimation in thick (up to 0.5 mm tissue is proposed. The techniques of FRET (Fluorescence Resonance Energy Transfer, FLIM (Fluorescence Lifetime Imaging Microscopy, FCS (Fluorescence Correlation Spectroscopy and FRAP (Fluorescence Recovery After Photobleaching are introduced and their applicability for quantitative imaging of biomolecular (co-localization and trafficking in live cells described. The advantage of two-photon versus one-photon excitation in relation to these techniques is discussed.

  14. Confocal endomicroscopy of the larynx

    Science.gov (United States)

    Just, T.; Wiechmann, T.; Stachs, O.; Stave, J.; Guthoff, R.; Hüttmann, G.; Pau, H. W.

    2012-02-01

    Beside the good image quality with the confocal laser scanning microscope (HRTII) and the Rostock Cornea Module (RCM), this technology can not be used to investigate the human larynx in vivo. To accomplish this, a rigid custom-made endoscope (KARL STORZ GmbH & Co. KG; Tuttlingen Germany) was developed. A connector was developed to connect the scanner head of the HRTII to the rigid endoscope. With the connector, the starting plane can be set manually. To achieve optical sectioning of the laryngeal tissue (80 μm per volume scan), the scanning mechanism of the HRTII needs to be activated using a foot switch. The devices consisting of the endoscope, HRTII, and the connector supply images of 400 x 400 μm and reach average penetration depths of 100-300 μm (λ/4 plate of the scanner head of the HRTII was removed). The lateral and axial resolutions are about 1-2 μm and 2 μm, respectively. In vivo rigid confocal endoscopy is demonstrated with an acquisition time for a volume scan of 6 s. The aim of this study was to differentiate pre-malignant laryngeal lesions from micro-invasive carcinoma of the larynx. 22 patients with suspicious lesions of the true vocal cords were included. This pilot study clearly demonstrates the possibility to detect dysplastic cells close to the basal cell layer and within the subepithelial space in lesions with small leukoplakia (thin keratin layer). These findings may have an impact on microlaryngoscopy to improve the precision for biopsy and on microlaryngoscopic laser surgery of the larynx to identify the margins of the pre-malignant lesion.

  15. Raman Spectroscopy of Ocular Tissue

    Science.gov (United States)

    Ermakov, Igor V.; Sharifzadeh, Mohsen; Gellermann, Warner

    The optically transparent nature of the human eye has motivated numerous Raman studies aimed at the non-invasive optical probing of ocular tissue components critical to healthy vision. Investigations include the qualitative and quantitative detection of tissue-specific molecular constituents, compositional changes occurring with development of ocular pathology, and the detection and tracking of ocular drugs and nutritional supplements. Motivated by a better understanding of the molecular mechanisms leading to cataract formation in the aging human lens, a great deal of work has centered on the Raman detection of proteins and water content in the lens. Several protein groups and the hydroxyl response are readily detectable. Changes of protein compositions can be studied in excised noncataractous tissue versus aged tissue preparations as well as in tissue samples with artificially induced cataracts. Most of these studies are carried out in vitro using suitable animal models and conventional Raman techniques. Tissue water content plays an important role in optimum light transmission of the outermost transparent ocular structure, the cornea. Using confocal Raman spectroscopy techniques, it has been possible to non-invasively measure the water to protein ratio as a measure of hydration status and to track drug-induced changes of the hydration levels in the rabbit cornea at various depths. The aqueous humor, normally supplying nutrients to cornea and lens, has an advantageous anterior location for Raman studies. Increasing efforts are pursued to non-invasively detect the presence of glucose and therapeutic concentrations of antibiotic drugs in this medium. In retinal tissue, Raman spectroscopy proves to be an important tool for research into the causes of macular degeneration, the leading cause of irreversible vision disorders and blindness in the elderly. It has been possible to detect the spectral features of advanced glycation and advanced lipooxydation end products in

  16. Non-resonant electromechanical energy harvesting using inter-ferroelectric phase transitions

    Energy Technology Data Exchange (ETDEWEB)

    Pérez Moyet, Richard; Rossetti, George A., E-mail: george.rossetti-jr@uconn.edu [Department of Materials Science and Engineering and Institute of Materials Science, University of Connecticut, Storrs, Connecticut 06269 (United States); Stace, Joseph; Amin, Ahmed [Sensors and Sonar Systems Department, Naval Undersea Warfare Center Newport, Newport, Rhode Island 02841 (United States); Finkel, Peter [Materials Science and Technology Division, Naval Research Laboratory, Washington, DC 20375 (United States)

    2015-10-26

    Non-resonant electromechanical energy harvesting is demonstrated under low frequency excitation (<50 Hz) using [110]{sub C}-poled lead indium niobate-lead magnesium niobate-lead titanate relaxor ferroelectric single crystals with compositions near the morphotropic phase boundary. The efficiency of power generation at the stress-induced phase transition between domain-engineered rhombohedral and orthorhombic ferroelectric states is as much as four times greater than is obtained in the linear piezoelectric regime under identical measurement conditions but during loading below the coercive stress of the phase change. The phase transition mode of electromechanical transduction holds potential for non-resonant energy harvesting from low-frequency vibrations and does not require mechanical frequency up-conversion.

  17. The nonlinear saturation of the non-resonant kinetically driven streaming instability

    CERN Document Server

    Gargate, L; Niemiec, J; Pohl, M; Bingham, R; Silva, L O

    2010-01-01

    A non-resonant instability for the amplification of the interstellar magnetic field in young Supernova Remnant (SNR) shocks was predicted by Bell (2004), and is thought to be relevant for the acceleration of cosmic ray (CR) particles. For this instability, the CRs streaming ahead of SNR shock fronts drive electromagnetic waves with wavelengths much shorter than the typical CR Larmor radius, by inducing a current parallel to the background magnetic field. We explore the nonlinear regime of the non-resonant mode using Particle-in-Cell (PIC) hybrid simulations, with kinetic ions and fluid electrons, and analyze the saturation mechanism for realistic CR and background plasma parameters. In the linear regime, the observed growth rates and wavelengths match the theoretical predictions; the nonlinear stage of the instability shows a strong reaction of both the background plasma and the CR particles, with the saturation level of the magnetic field varying with the CR parameters. The simulations with CR-to-background ...

  18. Langmuir probe study in the nonresonant current drive regime of helicon discharge

    Indian Academy of Sciences (India)

    Manash Kumar Paul; Dhiraj Bora

    2008-07-01

    Characterization of the current drive regime is done for helicon wave-generated plasma in a torus, at a very high operating frequency. A radiofrequency-compensated Langmuir probe is designed and used for the measurement of plasma parameters along with the electron energy distributions in radial scans of the plasma. The electron energy distribution patterns obtained in the operational regime suggest that Landau damping cannot be responsible for the efficient helicon discharge in the present study. A typical peaked radial density profile, high plasma temperature and absence of an appreciable amount of energetic electrons for resonant wave–particle interactions, suggest that the chosen operational regime is suitable for the study of nonresonant current drive by helicon wave. Successful and significant current drive achieved in our device clearly demonstrates the capability of nonresonant current drive by helicon waves in the present operational regime.

  19. Non-resonant interacting ion acoustic waves in a magnetized plasma

    Energy Technology Data Exchange (ETDEWEB)

    Maccari, Attilio [Technical Institute ' G Cardano' , Monterotondo, Rome (Italy)

    1999-01-29

    We perform an analytical and numerical investigation of the interaction among non-resonant ion acoustic waves in a magnetized plasma. Waves are supposed to be non-resonant, i.e. with different group velocities that are not close to each other. We use an asymptotic perturbation method, based on Fourier expansion and spatio-temporal rescaling. We show that the amplitude slow modulation of Fourier modes cannot be described by the usual nonlinear Schroedinger equation but by a new model system of nonlinear evolution equations. This system is C-integrable, i.e. it can be linearized through an appropriate transformation of the dependent and independent variables. We demonstrate that a subclass of solutions gives rise to envelope solitons. Each envelope soliton propagates with its own group velocity. During a collision solitons maintain their shape, the only change being a phase shift. Numerical results are used to check the validity of the asymptotic perturbation method. (author)

  20. Braking due to non-resonant magnetic perturbations and comparison with neoclassical toroidal viscosity torque in EXTRAP T2R

    Science.gov (United States)

    Frassinetti, L.; Sun, Y.; Fridström, R.; Menmuir, S.; Olofsson, K. E. J.; Brunsell, P. R.; Khan, M. W. M.; Liang, Y.; Drake, J. R.

    2015-09-01

    The non-resonant magnetic perturbation (MP) braking is studied in the EXTRAP T2R reversed-field pinch (RFP) and the experimental braking torque is compared with the torque expected by the neoclassical toroidal viscosity (NTV) theory. The EXTRAP T2R active coils can apply magnetic perturbations with a single harmonic, either resonant or non-resonant. The non-resonant MP produces velocity braking with an experimental torque that affects a large part of the core region. The experimental torque is clearly related to the plasma displacement, consistent with a quadratic dependence as expected by the NTV theory. The work show a good qualitative agreement between the experimental torque in a RFP machine and NTV torque concerning both the torque density radial profile and the dependence on the non-resonant MP harmonic.

  1. Waves guided by density ducts in magnetoplasma in the nonresonant region of the whistler frequency range

    Energy Technology Data Exchange (ETDEWEB)

    Es’kin, V. A.; Zaboronkova, T. M.; Kudrin, A. V., E-mail: kud@rf.unn.ru; Ostafiychuk, O. M. [Lobachevskii State University of Nizhni Novgorod (Russian Federation)

    2015-03-15

    Guidance of azimuthally symmetric waves by cylindrical density ducts in magnetoplasma in the nonresonant region of the whistler frequency range is investigated. It is demonstrated that eigenmodes existing at the studied frequencies in ducts with enhanced plasma density allow simplified description that makes analysis of the features of their guided propagation much easier. The results of calculation of the dispersion characteristics and field structure of the whistler modes supported by such ducts are presented.

  2. Femtosecond measurements of the nonresonant nonlinear index in AlGaAs

    Science.gov (United States)

    LaGasse, M. J.; Anderson, K. K.; Wang, C. A.; Haus, H. A.; Fujimoto, J. G.

    1990-01-01

    Time-division interferometry with 430 fs tunable laser pulses is used for direct femtosecond measurements of the wavelength dependence of the nonresonant nonlinear index of refraction, n2, in AlGaAs waveguides at room temperature. Below band-gap n2 values of ˜10-12 cm2/W are observed with resonant enhancement as the laser wavelength is tuned toward the band edge.

  3. Microcavity with saturable nonlinearity under simultaneous resonant and nonresonant pumping: multistability, Hopf bifurcations and chaotic behaviour.

    Science.gov (United States)

    Iorsh, Ivan; Alodjants, Alexander; Shelykh, Ivan A

    2016-05-30

    We studied optical response of microcavity non-equilibrium exciton-polariton Bose-Einstein condensate with saturable nonlinearity under simultaneous resonant and non-resonant pumping. We demonstrated the emergence of multistabile behavior due to the saturation of the excitonic absorption. Stable periodic Rabi-type oscillations of the excitonic and photonic condensate components in the regime of the stationary pump and their transition to the chaotic dynamics through the cascade of Hopf bifurcations by tuning of the electrical pump are revealed.

  4. Microcavity with saturable nonlinearity under simultaneous resonant and nonresonant pumping: multistability, Hopf bifurcations and chaotic behaviour

    CERN Document Server

    Iorsh, Ivan; Shelykh, Ivan

    2016-01-01

    We studied optical response of microcavity non-equilibrium exciton-polariton Bose-Einstein condensate with saturable nonlinearity under simultaneous resonant and non-resonant pumping. We demonstrated the emergence of multistabile behavior due to the satutration of the excitonic absorbtion. Stable periodic Rabi- type oscillations of the excitonic and photonic condensate components in the regime of the stationary pump and their transition to the chaotic dynamics through the cascade of Hopf bifurcations by tuning of the electrical pump are revealed.

  5. Zinc Oxide Nanocrystals for Non-resonant Nonlinear Optical Microscopy in Biology and Medicine.

    Science.gov (United States)

    Kachynski, Aliaksandr V; Kuzmin, Andrey N; Nyk, Marcin; Roy, Indrajit; Prasad, Paras N

    2008-07-24

    In this paper we show that biocompatible zinc oxide (ZnO) nanocrystals (NCs) having non-centrosymmetric structure can be used as non-resonant nonlinear optical probes for targeting in bioimaging applications in vitro by use of the second order processes of second harmonic and sum frequency generation, as well as the third order process of four wave mixing. These non-resonant processes provide advantages above and beyond traditional two-photon bioimaging: (i) the probes do not photo-bleach; (ii) the input wavelength can be judiciously selected; and (iii) no heat is dissipated into the cells, ensuring longer cell viability and ultimately longer imaging times. ZnO NCs have been synthesized in organic media by using a non-hydrolytic sol-gel process, and subsequently dispersed in aqueous media using phospholipid micelles, and incorporated with the biotargeting molecule folic acid (FA). Sum Frequency, Second Harmonic and non-resonant four wave mixing non-linear signals from this stable dispersion of ZnO NCs, targeted to the live tumor (KB) cells were used for imaging. Robust intracellular accumulation of the targeted (FA incorporated) ZnO nanocrystals could be observed, without any indication of cytotoxicity.

  6. Submillimeter Confocal Imaging Active Module

    Science.gov (United States)

    Hong, John; Mehdi, Imran; Siegel, Peter; Chattopadhyay, Goutam; Cwik, Thomas; Rowell, Mark; Hacker, John

    2009-01-01

    The term submillimeter confocal imaging active module (SCIAM) denotes a proposed airborne coherent imaging radar system that would be suitable for use in reconnaissance, surveillance, and navigation. The development of the SCIAM would include utilization and extension of recent achievements in monolithic microwave integrated circuits capable of operating at frequencies up to and beyond a nominal radio frequency of 340 GHz. Because the SCIAM would be primarily down-looking (in contradistinction to primarily side-looking), it could be useful for imaging shorter objects located between taller ones (for example, objects on streets between buildings). The SCIAM would utilize a confocal geometry to obtain high cross-track resolution, and would be amenable to synthetic-aperture processing of its output to obtain high along-track resolution. The SCIAM (see figure) would include multiple (two in the initial version) antenna apertures, separated from each other by a cross-track baseline of suitable length (e.g., 1.6 m). These apertures would both transmit the illuminating radar pulses and receive the returns. A common reference oscillator would generate a signal at a controllable frequency of (340 GHz + (Delta)f)/N, where (Delta)f is an instantaneous swept frequency difference and N is an integer. The output of this oscillator would be fed to a frequency- multiplier-and-power-amplifier module to obtain a signal, at 340 GHz + (Delta)f, that would serve as both the carrier signal for generating the transmitted pulses and a local-oscillator (LO) signal for a receiver associated with each antenna aperture. Because duplexers in the form of circulators or transmit/receive (T/R) switches would be lossy and extremely difficult to implement, the antenna apertures would be designed according to a spatial-diplexing scheme, in which signals would be coupled in and out via separate, adjacent transmitting and receiving feed horns. This scheme would cause the transmitted and received beams

  7. Distinguishing non-resonant four-wave-mixing noise in coherent stokes and anti-stokes Raman scattering

    Science.gov (United States)

    Marks, Daniel L. (Inventor); Boppart, Stephen A. (Inventor)

    2009-01-01

    A method of examining a sample comprises exposing the sample to a pump pulse of electromagnetic radiation for a first period of time, exposing the sample to a stimulant pulse of electromagnetic radiation for a second period of time which overlaps in time with at least a portion of the first exposing, to produce a signal pulse of electromagnetic radiation for a third period of time, and interfering the signal pulse with a reference pulse of electromagnetic radiation, to determine which portions of the signal pulse were produced during the exposing of the sample to the stimulant pulse. The first and third periods of time are each greater than the second period of time.

  8. Optical tweezers for confocal microscopy

    Science.gov (United States)

    Hoffmann, A.; Meyer zu Hörste, G.; Pilarczyk, G.; Monajembashi, S.; Uhl, V.; Greulich, K. O.

    2000-11-01

    In confocal laser scanning microscopes (CLSMs), lasers can be used for image formation as well as tools for the manipulation of microscopic objects. In the latter case, in addition to the imaging lasers, the light of an extra laser has to be focused into the object plane of the CLSM, for example as optical tweezers. Imaging as well as trapping by optical tweezers can be done using the same objective lens. In this case, z-sectioning for 3D imaging shifts the optical tweezers with the focal plane of the objective along the optical axis, so that a trapped object remains positioned in the focal plane. Consequently, 3D imaging of trapped objects is impossible without further measures. We present an experimental set-up keeping the axial trapping position of the optical tweezers at its intended position whilst the focal plane can be axially shifted over a distance of about 15 μm. It is based on fast-moving correctional optics synchronized with the objective movement. First examples of application are the 3D imaging of chloroplasts of Elodea densa (Canadian waterweed) in a vigorous cytoplasmic streaming and the displacement of zymogen granules in pancreatic cancer cells (AR42 J).

  9. Confocal Endomicroscopy of Colorectal Polyps

    Directory of Open Access Journals (Sweden)

    Vivian M. Ussui

    2012-01-01

    Full Text Available Confocal laser endomicroscopy (CLE is one of several novel methods that provide real-time, high-resolution imaging at a micron scale via endoscopes. CLE has the potential to be a disruptive technology in that it can change the current algorithms that depend on biopsy to perform surveillance of high-risk conditions. Furthermore, it allows on-table decision making that has the potential to guide therapy in real time and reduce the need for repeated procedures. CLE and related technologies are often termed “virtual biopsy” as they simulate the images seen in traditional histology. However, the imaging of living tissue allows more than just pragmatic convenience; it also allows imaging of living tissue such as active capillary circulation, cellular death, and vascular and endothelial translocation, thus extending beyond what is capable in traditional biopsy. Immediate potential applications of CLE are to guide biopsy sampling in Barrett's esophagus and inflammatory bowel disease surveillance, evaluation of colorectal polyps, and intraductal imaging of the pancreas and bile duct. Data on these applications is rapidly emerging, and more is needed to clearly demonstrate the optimal applications of CLE. In this paper, we will focus on the role of CLE as applied to colorectal polyps detected during colonoscopy.

  10. Confocal Annular Josephson Tunnel Junctions

    Science.gov (United States)

    Monaco, Roberto

    2016-09-01

    The physics of Josephson tunnel junctions drastically depends on their geometrical configurations and here we show that also tiny geometrical details play a determinant role. More specifically, we develop the theory of short and long annular Josephson tunnel junctions delimited by two confocal ellipses. The behavior of a circular annular Josephson tunnel junction is then seen to be simply a special case of the above result. For junctions having a normalized perimeter less than one, the threshold curves in the presence of an in-plane magnetic field of arbitrary orientations are derived and computed even in the case with trapped Josephson vortices. For longer junctions, a numerical analysis is carried out after the derivation of the appropriate motion equation for the Josephson phase. We found that the system is modeled by a modified and perturbed sine-Gordon equation with a space-dependent effective Josephson penetration length inversely proportional to the local junction width. Both the fluxon statics and dynamics are deeply affected by the non-uniform annulus width. Static zero-field multiple-fluxon solutions exist even in the presence of a large bias current. The tangential velocity of a traveling fluxon is not determined by the balance between the driving and drag forces due to the dissipative losses. Furthermore, the fluxon motion is characterized by a strong radial inward acceleration which causes electromagnetic radiation concentrated at the ellipse equatorial points.

  11. Pseudoexfoliation syndrome: in vivo confocal microscopy analysis.

    Science.gov (United States)

    Martone, Gianluca; Casprini, Fabrizio; Traversi, Claudio; Lepri, Francesca; Pichierri, Patrizia; Caporossi, Aldo

    2007-08-01

    Pseudoexfoliation (PEX) syndrome is a common ocular disease that also affects the cornea. A case of clinical PEX syndrome, studied by in vivo corneal confocal microscopy is reported. The morphological analysis of the confocal images demonstrated hyper-reflective deposits and several dendritic cells in the basal epithelial layer. A fibrillar subepithelial structure was also found. The endothelial layer showed cell anomalies (polymegathism and pleomorphism) and hyper-reflective small endothelial deposits. Confocal microscopy is an in vivo imaging method that may provide new information on corneal alterations in PEX, and detect early corneal features.

  12. Confocal Scanning Microscope for Nuclear Photoemulsion

    CERN Document Server

    Batusov, Yu A; Soroko, L M

    2005-01-01

    The application of the confocal scanning microscope to the objects in the nuclear photoemulsion is described. An array of 27 microtomograms of {\\it single} silver grain is shown. The cross sections of the same particle track of diameter 1 $\\mu$m, detected by means of the confocal scanning microscope with open and annular apertures, are presented. It was shown that the confocal scanning microscope opens indeed new opportunities for the nuclear photoemulsion technique to get previously inaccessible information for physics of the short-living particles.

  13. Confocal Laser Endomicroscopy in Inflammatory Bowel Disease

    DEFF Research Database (Denmark)

    Rasmussen, Ditlev Nytoft; Karstensen, John Gásdal; Riis, Lene Buhl

    2015-01-01

    of histological features such as colonic crypts, epithelial gaps and epithelial leakiness to fluorescein. CONCLUSIONS: Confocal laser endomicroscopy remains an experimental but emerging tool for assessment of inflammatory bowel disease. It is the only method that enables in vivo functional assessment......BACKGROUND AND AIMS: Confocal laser endomicroscopy is an endoscopic method that provides in vivo real-time imaging of the mucosa at a cellular level, elucidating mucosal changes that are undetectable by white light endoscopy. This paper systematically reviews current indications and perspectives...... of confocal laser endomicroscopy for inflammatory bowel disease. METHODS: Available literature was searched systematically for studies applying confocal laser endomicroscopy in Crohn's disease or ulcerative colitis. Relevant literature was reviewed and only studies reporting original clinical data were...

  14. Diffractive elements performance in chromatic confocal microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Garzon, J; Duque, D; Alean, A; Toledo, M [Grupo de Optica y EspectroscopIa, Centro de Ciencia Basica, Universidad Pontificia Bolivariana. Medellin (Colombia); Meneses, J [Laboratorio de Optica y Tratamiento de Senales, Instituto de Fisica, Universidad Industrial de Santander, Bucaramanga (Colombia); Gharbi, T, E-mail: jgarzonr10@une.net.co [Laboratoire d' Optique P. M. Duffieux, UMR-6603 CNR/Universite de Franche-Comte. 16 route de Gray, 25030 Besancon Cedex (France)

    2011-01-01

    The Confocal Laser Scanning Microscopy (CLSM) has been widely used in the semiconductor industry and biomedicine because of its depth discrimination capability. Subsequent to this technique has been developed in recent years Chromatic Confocal Microscopy. This method retains the same principle of confocal and offers the added advantage of removing the axial movement of the moving system. This advantage is usually accomplished with an optical element that generates a longitudinal chromatic aberration and a coding system that relates the axial position of each point of the sample with the wavelength that is focused on each. The present paper shows the performance of compact chromatic confocal microscope when some different diffractive elements are used for generation of longitudinal chromatic aberration. Diffractive elements, according to the process and manufacturing parameters, may have different diffraction efficiency and focus a specific wavelength in a specific focal position. The performance assessment is carried out with various light sources which exhibit an incoherent behaviour and a broad spectral width.

  15. Analytical design of a confocal resonator

    CERN Document Server

    Ferrari, A; Ziemann, Volker; CERN. Geneva. AB Department

    2003-01-01

    A confocal resonator may be used as a pick-up for frequencies in the multi-GHz region, in order to monitor the bunch spacing and/or the bunch length in the CTF3 drive beam. In this note, we collect some formulae regarding the design of a confocal resonator in order to facilitate the estimation of relevant parameters in a later more careful numerical study

  16. New techniques in antibiotic discovery and resistance: Raman spectroscopy.

    Science.gov (United States)

    Carey, Paul R; Heidari-Torkabadi, Hossein

    2015-09-01

    Raman spectroscopy can play a role in both antibiotic discovery and understanding the molecular basis of resistance. A major challenge in drug development is to measure the population of the drug molecules inside a cell line and to follow the chemistry of their reactions with intracellular targets. Recently, a protocol based on Raman microscopy has been developed that achieves these goals. Drug candidates are soaked into live bacterial cells and subsequently the cells are frozen and freeze-dried. The samples yield exemplary (nonresonance) Raman data that provide a measure of the number of drug molecules within each cell, as well as details of drug-target interactions. Results are discussed for two classes of compounds inhibiting either β-lactamase or dihydrofolate reductase enzymes in a number of Gram-positive or Gram-negative cell lines. The advantages of the present protocol are that it does not use labels and it can measure the kinetics of cell-compound uptake on the time scale of minutes. Spectroscopic interpretation is supported by in vitro Raman experiments. Studying drug-target interactions in aqueous solution and in single crystals can provide molecular level insights into drug-target interactions, which, in turn, provide the underpinnings of our understanding of data from bacterial cells. Thus, the applicability of X-ray crystallographic-derived data to in-cell chemistry can be tested. © 2015 New York Academy of Sciences.

  17. Confocal microlaparoscope for imaging the fallopian tube

    Science.gov (United States)

    Wu, Tzu-Yu; Schafer, Rachel; Rouse, Andrew R.; Gmitro, Arthur F.

    2012-02-01

    Recent evidence suggests that epithelial ovarian cancer may originate in the fimbriated end of the fallopian tube1. Unlike many other cancers, poor access to the ovary and fallopian tubes has limited the ability to study the progression of this deadly disease and to diagnosis it during the early stage when it is most amenable to therapy. We have previously reported on a rigid confocal microlaparoscope system that is currently undergoing a clinical trial to image the epithelial surface of the ovary2. In order to gain in vivo access to the fallopian tubes we have developed a new confocal microlaparoscope with an articulating distal tip. The new instrument builds upon the technology developed for the existing confocal microlaparoscope. It has an ergonomic handle fabricated by a rapid prototyping printer. While maintaining compatibility with a 5 mm trocar, the articulating distal tip of the instrument consists of a 2.2 mm diameter bare fiber bundle catheter with automated dye delivery for fluorescence imaging. This small and flexible catheter design should enable the confocal microlaparoscope to image early stage ovarian cancer arising inside the fallopian tube. Early ex vivo mages of human fallopian tube and in vivo imaging results from recent open surgeries using the rigid confocal microlaparoscope system are presented. Ex vivo images from animal models using the new articulating bare fiber system are also presented. These high quality images collected by the new flexible system are similar in quality to those obtained from the epithelial surface of ovaries with the rigid clinical confocal microlaparoscope.

  18. Raman microscopy of individual living human embryonic stem cells

    Science.gov (United States)

    Novikov, S. M.; Beermann, J.; Bozhevolnyi, S. I.; Harkness, L. M.; Kassem, M.

    2010-04-01

    We demonstrate the possibility of mapping the distribution of different biomolecules in living human embryonic stem cells grown on glass substrates, without the need for fluorescent markers. In our work we improve the quality of measurements by finding a buffer that gives low fluorescence, growing cells on glass substrates (whose Raman signals are relatively weak compared to that of the cells) and having the backside covered with gold to improve the image contrast under direct white light illumination. The experimental setup used for Raman microscopy is the commercially available confocal scanning Raman microscope (Alpha300R) from Witec and sub-μm spatially resolved Raman images were obtained using a 532 nm excitation wavelength.

  19. Nanophotonic waveguide enhanced Raman spectroscopy of biological submonolayers

    CERN Document Server

    Dhakal, Ashim; Peyskens, Frédéric; Jans, Karolien; Thomas, Nicolas Le; Baets, Roel

    2016-01-01

    Characterizing a monolayer of biological molecules has been a major challenge. We demonstrate nanophotonic wave-guide enhanced Raman spectroscopy (NWERS) of monolayers in the near-infrared region, enabling real-time measurements of the hybridization of DNA strands and the density of sub-monolayers of biotin-streptavidin complex immobilized on top of a photonics chip. NWERS is based on enhanced evanescent excitation and collection of spontaneous Raman scattering near nanophotonic waveguides, which for a one centimeter silicon nitride waveguide delivers a signal that is more than four orders of magnitude higher in comparison to a confocal Raman microscope. The reduced acquisition time and specificity of the signal allows for a quantitative and real-time characterization of surface species, hitherto not possible using Raman spectroscopy. NWERS provides a direct analytic tool for monolayer research and also opens a route to compact microscope-less lab-on-a-chip devices with integrated sources, spectrometers and d...

  20. Metal-coated magnetic nanoparticles for surface enhanced Raman scattering studies

    Indian Academy of Sciences (India)

    G V Pavan Kumar; N Rangarajan; B Sonia; P Deepika; Nashiour Rohman; Chandrabhas Narayana

    2011-04-01

    We report the optimization and usage of surfactantless, water dispersible Ag and Au-coated –Fe2O3 nanoparticles for applications in surface-enhanced Raman scattering (SERS). These nanoparticles, with plasmonic as well as super paramagnetic properties exhibit Raman enhancement factors of the order of 106 (105) for Ag (Au) coating, which are on par with the conventional Ag and Au nanoparticles. Raman markers like 2-naphthalenethiol, rhodamine-B and rhodamine-6G have been adsorbed to these nanoparticles and tested for nonresonant SERS at low concentrations. Further, to confirm the robustness of Ag-coated nanoparticles, we have performed temperaturedependent SERS in the temperature range of 77–473 K. The adsorbed molecules exhibit stable SERS spectra except at temperatures >323 K, where the thermal desorption of test molecule (naphthalenethiol) were evident. The magnetic properties of these nanoparticles combined with SERS provide a wide range of applications.

  1. Quantitative, Comparable Coherent Anti-Stokes Raman Scattering (CARS) Spectroscopy: Correcting Errors in Phase Retrieval

    CERN Document Server

    Camp, Charles H; Cicerone, Marcus T

    2015-01-01

    Coherent anti-Stokes Raman scattering (CARS) microspectroscopy has demonstrated significant potential for biological and materials imaging. To date, however, the primary mechanism of disseminating CARS spectroscopic information is through pseudocolor imagery, which explicitly neglects a vast majority of the hyperspectral data. Furthermore, current paradigms in CARS spectral processing do not lend themselves to quantitative sample-to-sample comparability. The primary limitation stems from the need to accurately measure the so-called nonresonant background (NRB) that is used to extract the chemically-sensitive Raman information from the raw spectra. Measurement of the NRB on a pixel-by-pixel basis is a nontrivial task; thus, reference NRB from glass or water are typically utilized, resulting in error between the actual and estimated amplitude and phase. In this manuscript, we present a new methodology for extracting the Raman spectral features that significantly suppresses these errors through phase detrending ...

  2. Phase-shift effect of amplitude spread function on spectrum and image formation in coherent Raman scattering microspectroscopy.

    Science.gov (United States)

    Fukutake, Naoki

    2016-03-01

    Coherent Raman scattering microspectroscopy, which includes coherent anti-Stokes Raman scattering (CARS) and stimulated Raman scattering (SRS) microspectroscopy, permits label-free hyperspectral imaging. We report the theoretical study of the phase-shift effect of the impulse response function on the spectral and image-forming properties of coherent Raman scattering microspectroscopy. We show that the spectrum and image are influenced by not only the NA of objective for excitation (NA(ex)) but also that for signal collection (NA(col)), in association with the phase-shift effect. We discuss that, under the condition NA(ex)≠NA(col), both the spectrum and the image become deformed by the phase-shift effect, which can be applied to the direct measurement of the imaginary part of the nonlinear susceptibility in CARS spectroscopy. We point out that, even in SRS microscopy, the nonresonant background can contribute to the image formation and cause the artifact in the image.

  3. Transition from nonresonant to resonant random lasers by the geometrical confinement of disorder.

    Science.gov (United States)

    Ghofraniha, N; Viola, I; Zacheo, A; Arima, V; Gigli, G; Conti, C

    2013-12-01

    We report on a transition in random lasers that is induced by the geometrical confinement of the emitting material. Different dye doped paper devices with controlled geometry are fabricated by soft lithography and show two distinguished behaviors in the stimulated emission: in the absence of boundary constraints, the energy threshold decreases for larger laser volumes showing the typical trend of diffusive nonresonant random lasers, while when the same material is lithographed into channels, the walls act as cavity and the resonant behavior typical of standard lasers is observed. The experimental results are consistent with the general theories of random and standard lasers and a clear phase diagram of the transition is reported.

  4. Enhanced non-resonant light transmission through subwavelength slits in metal

    CERN Document Server

    Pors, Anders; Sahakyan, Khachik; Bozhevolnyi, Sergey I

    2016-01-01

    We analytically describe light transmission through a single subwavelength slit in a thin perfect electric conductor screen for the incident polarization being perpendicular to the slit, and derive simple, yet accurate, expressions for the average electric field in the slit and the transmission efficiency. The analytic results are consistent with full-wave numerical calculations, and demonstrate that slits of widths ~100nm in real metals may feature non-resonant (i.e., broadband) field enhancements of ~100 and transmission efficiency of ~10 at infrared or terahertz frequencies, with the associated metasurface-like array of slits becoming transparent to the incident light.

  5. Biophysical basis for noninvasive skin cancer detection using Raman spectroscopy

    Science.gov (United States)

    Feng, Xu; Moy, Austin J.; Markey, Mia K.; Fox, Matthew C.; Reichenberg, Jason S.; Tunnell, James W.

    2016-03-01

    Raman spectroscopy (RS) is proving to be a valuable tool for real time noninvasive skin cancer detection via optical fiber probe. However, current methods utilizing RS for skin cancer diagnosis rely on statistically based algorithms to provide tissue classification and do not elucidate the underlying biophysical changes of skin tissue. Therefore, we aim to use RS to explore skin biochemical and structural characteristics and then correlate the Raman spectrum of skin tissue with its disease state. We have built a custom confocal micro-Raman spectrometer system with an 830nm laser light. The high resolution capability of the system allows us to measure spectroscopic features from individual tissue components in situ. Raman images were collected from human skin samples from Mohs surgical biopsy, which were then compared with confocal laser scanning, two-photon fluorescence and hematoxylin and eosin-stained images to develop a linear model of skin tissue Raman spectra. In this model, macroscopic tissue spectra obtained from RS fiber probe were fit into a linear combination of individual basis spectra of primary skin constituents. The fit coefficient of the model explains the biophysical changes spanning a range of normal and various disease states. The model allows for determining parameters similar to that a pathologist is familiar reading and will be a significant guidance in developing RS diagnostic decision schemes.

  6. Raman microscopy of individual living human embryonic stem cells

    DEFF Research Database (Denmark)

    Novikov, Sergey M.; Beermann, Jonas; Bozhevolnyi, Sergey I.;

    2010-01-01

    We demonstrate the possibility of mapping the distribution of different biomolecules in living human embryonic stem cells grown on glass substrates, without the need for fluorescent markers. In our work we improve the quality of measurements by finding a buffer that gives low fluorescence, growing...... cells on glass substrates (whose Raman signals are relatively weak compared to that of the cells) and having the backside covered with gold to improve the image contrast under direct white light illumination. The experimental setup used for Raman microscopy is the commercially available confocal...

  7. Performance analysis and experimental verification of mid-range wireless energy transfer through non-resonant magnetic coupling

    DEFF Research Database (Denmark)

    Peng, Liang; Wang, Jingyu; Zhejiang University, Hangzhou, China, L.

    2011-01-01

    In this paper, the efficiency analysis of a mid-range wireless energy transfer system is performed through non-resonant magnetic coupling. It is shown that the self-resistance of the coils and the mutual inductance are critical in achieving a high efficiency, which is indicated by our theoretical...... formulation and verified in our experiments. It is experimentally shown that high efficiency, up to 65%, can be realized even in a non-resonant wireless energy system which employs a device part with moderate or low quality factor. We also address some aspects of a practical wireless energy transfer system...... and show that careful design of the de-tuned system can intrinsically minimize the power dissipated in the source part. Our non-resonant scheme presented in this paper allows flexible design and fabrication of a wireless energy transfer systems with transfer distance being several times of the coils...

  8. Raman microspectroscopy for visualization of peripheral nerves

    Science.gov (United States)

    Minamikawa, Takeo; Harada, Yoshinori; Koizumi, Noriaki; Takamatsu, Tetsuro

    2013-02-01

    The peripheral nervous system plays an important role in motility, sensory, and autonomic functions of the human body. Preservation of peripheral nerves in surgery is essential for improving quality of life of patients. To preserve peripheral nerves, detection of ne peripheral nerves that cannot be identi ed by human eye or under white light imaging is necessary. In this study, we sought to provide a proof-of-principle demonstration of a label-free detection technique of peripheral nerve tissues against adjacent tissues that employs spontaneous Raman microspectroscopy. A line-illumination confocal Raman microscope was used for the experiment. A laser operating at the wavelength of 532 nm was used as an excitation laser light. We obtained Raman spectra of peripheral nerve, brous connective tissue, skeletal muscle, blood vessel, and adipose tissue of Wistar rats, and extracted speci c spectral features of peripheral nerves and adjacent tissues. By applying multivariate image analysis, peripheral nerves were clearly detected against adjacent tissues without any preprocessing neither xation nor staining. These results suggest the potential of the Raman spectroscopic observation for noninvasive and label-free nerve detection, and we expect this method could be a key technique for nerve-sparing surgery.

  9. Anomalous non-resonant microwave absorption in SmFeAs(O,F) polycrystalline sample

    Energy Technology Data Exchange (ETDEWEB)

    Onyancha, R.B., E-mail: 08muma@gmail.com [Department of Physics, College of Science, Engineering and Technology, University of South Africa, Johannesburg, 1710 (South Africa); Shimoyama, J. [Department of Applied Chemistry, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo (Japan); Singh, S.J. [Leibniz-Institute for Solid State and Materials Research, IFW-Dresden, D-01171 Dresden (Germany); Hayashi, K.; Ogino, H. [Department of Applied Chemistry, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo (Japan); Srinivasu, V.V. [Department of Physics, College of Science, Engineering and Technology, University of South Africa, Johannesburg, 1710 (South Africa)

    2017-02-15

    Highlights: • The non-resonant microwave absorption (NRMA) line shape in evolved with microwave power. • Observed a cross over from ‘normal’ absorption to ‘anomalous’ absorption as a function of microwave power. • The anomalous absorption has been explained in the context of non-hysteretic Josephson junction. - Abstract: Here we present the non-resonant microwave absorption (NRMA) studies on SmFeAsO{sub 0.88}F{sub 0.12} polycrystalline sample measured at 6.06 K with the magnetic field swept from −250 G to +250 G at a frequency of 9.45 GHz. It was observed that the (NRMA) line shape evolves as a function of microwave power. Again, the signal intensity increases from 22.83 µW to 0.710 mW where it reaches a maximum and quite remarkably it changed from ‘normal’ absorption to ‘anomalous’ absorption at 2.247 mW, then the intensity decreases with further increase of microwave power. The crossover from ‘normal’ to ‘anomalous’ NRMA absorption and its dependence on microwave power is a new phenomenon in iron pnictides superconductors and we have attributed this anomaly to come from non-hysteretic Josephson junction.

  10. Non-Resonant Magnetoelectric Energy Harvesting Utilizing Phase Transformation in Relaxor Ferroelectric Single Crystals

    Directory of Open Access Journals (Sweden)

    Peter Finkel

    2015-12-01

    Full Text Available Recent advances in phase transition transduction enabled the design of a non-resonant broadband mechanical energy harvester that is capable of delivering an energy density per cycle up to two orders of magnitude larger than resonant cantilever piezoelectric type generators. This was achieved in a [011] oriented and poled domain engineered relaxor ferroelectric single crystal, mechanically biased to a state just below the ferroelectric rhombohedral (FR-ferroelectric orthorhombic (FO phase transformation. Therefore, a small variation in an input parameter, e.g., electrical, mechanical, or thermal will generate a large output due to the significant polarization change associated with the transition. This idea was extended in the present work to design a non-resonant, multi-domain magnetoelectric composite hybrid harvester comprised of highly magnetostrictive alloy, [Fe81.4Ga18.6 (Galfenol or TbxDy1-xFe2 (Terfenol-D], and lead indium niobate–lead magnesium niobate–lead titanate (PIN-PMN-PT domain engineered relaxor ferroelectric single crystal. A small magnetic field applied to the coupled device causes the magnetostrictive element to expand, and the resulting stress forces the phase change in the relaxor ferroelectric single crystal. We have demonstrated high energy conversion in this magnetoelectric device by triggering the FR-FO transition in the single crystal by a small ac magnetic field in a broad frequency range that is important for multi-domain hybrid energy harvesting devices.

  11. Quiescence of magnetic braking and control of 3D non-resonance in KSTAR

    Science.gov (United States)

    Park, J.-K.; in, Y.; Jeon, Y. M.; Logan, N. C.; Wang, Z. R.; Menard, J. E.; Kim, J. H.; Ko, W. H.; Kstar Team

    2016-10-01

    Magnetic braking using non-axisymmetric (3D) field is a promising tool to control rotation in tokamaks and thereby micro-to-macro instabilities. Ideally magnetic braking should induce only neoclassical momentum transport, without provoking resonant instabilities or unnecessary perturbations in particle or heat transport. Indeed in KSTAR, it was shown that the 3 rows of internal coils could be used to generate highly non-resonant n =1 with backward-helicity field distribution, called -90 phasing, and to change rotation without any perturbations to other transport channels. Recent KSTAR experiments, however, have also shown that the broad-wavelength field distribution, called 0 phasing, is rather more quiescent whereas -90 phasing can be highly degrading especially in high q95 plasmas. IPEC and NTV modeling are consistent with both observations, and further provide the optimal point in coil phasing and amplitude space. Additional experiments and comparisons with modeling all imply the sensitivity of plasma response to remnant resonant field, and thus importance of non-resonance control, to accomplish quiescent magnetic braking. This work was supported by DOE Contract DE-AC02-09CH11466.

  12. Observation of optical domino modes in arrays of non-resonant plasmonic nanoantennas

    Science.gov (United States)

    Sinev, Ivan S.; Samusev, Anton K.; Voroshilov, Pavel M.; Mukhin, Ivan S.; Denisyuk, Andrey I.; Guzhva, Mikhail E.; Belov, Pavel A.; Simovski, Constantin R.

    2014-09-01

    Domino modes are highly-confined collectivemodes that were first predicted for a periodic arrangement of metallic parallelepipeds in far-infrared region. The main feature of domino modes is the advantageous distribution of the local electric field, which is concentrated between metallic elements (hot spots), while its penetration depth in metal is much smaller than the skin-depth. Therefore, arrays of non-resonant plasmonic nanoantennas exhibiting domino modes can be employed as broadband light trapping coatings for thin-film solar cells. However, until now in the excitation of such modes was demonstrated only in numerical simulations. Here, we for the first time demonstrate experimentally the excitation of optical domino modes in arrays of non-resonant plasmonic nanoantennas. We characterize the nanoantenna arrays produced by means of electron beam lithography both experimentally using an aperture-type near-field scanning optical microscope and numerically. The proof of domino modes concept for plasmonic arrays of nanoantennas in the visible spectral region opens new pathways for development of low-absorptive structures for effective focusing of light at the nanoscale.

  13. Plane wave excitation-detection of non-resonant plasmons along finite-width graphene strips.

    Science.gov (United States)

    Gómez-Díaz, J S; Esquius-Morote, M; Perruisseau-Carrier, J

    2013-10-21

    An approach to couple free-space waves and non-resonant plasmons propagating along graphene strips is proposed based on the periodic modulation of the graphene strip width. The solution is technologically very simple, scalable in frequency, and provides customized coupling angle and intensity. Moreover, the coupling properties can be dynamically controlled at a fixed frequency via the graphene electrical field effect, enabling advanced and flexible plasmon excitation-detection strategies. We combine a previously derived scaling law for graphene strips with leaky-wave theory borrowed from microwaves to achieve rigorous and efficient modeling and design of the structure. In particular we analytically derive its dispersion, predict its coupling efficiency and radiated field structure, and design strip configurations able to fulfill specific coupling requirements. The proposed approach and developed methods are essential to the recent and fundamental problem of the excitation-detection of non-resonant plasmons propagating along a continuous graphene strip, and could pave the way to smart all-graphene sensors and transceivers.

  14. Temperature dependence of cross sections for meson-meson nonresonant reactions in hadronic matter

    CERN Document Server

    Shen, Zhen-Yu

    2014-01-01

    We study unpolarized cross sections for the endothermic nonresonant reactions: pion pion to rho rho for I=2, KK to K*K* for I=1, KK* to K*K* for I=1, pion K to rho K* for I=3/2, pion K* to rho K* for I=3/2, rho K to rho K* for I=3/2, and pion K* to rho K for I=3/2, which take place in hadronic matter. We provide a potential that is given by perturbative QCD with loop corrections at short distances, becomes a distance-independent and temperature-dependent value at long distances, and has a spin-spin interaction with relativistic modifications. The Schrodinger equation with the potential yields temperature-dependent meson masses and mesonic quark-antiquark relative-motion wave functions. In the first Born approximation with the quark-interchange mechanism, the temperature dependence of the potential, meson masses and wave functions brings about temperature dependence of unpolarized cross sections for the seven nonresonant reactions. Noticeably, rapid changes of pion and K radii cause an increase in peak cross s...

  15. Influence of non-resonant effects on the dynamics of quantum logic gates at room temperature

    Science.gov (United States)

    Berman, G. P.; Bishop, A. R.; Doolen, G. D.; López, G. V.; Tsifrinovich, V. I.

    2001-01-01

    We study numerically the influence of non-resonant effects on the dynamics of a single- π-pulse quantum CONTROL-NOT (CN) gate in a macroscopic ensemble of four-spin molecules at room temperature. The four nuclear spins in each molecule represent a four-qubit register. The qubits are “labeled” by the characteristic frequencies, ωk, ( k=0-3) due to the Zeeman interaction of the nuclear spins with the magnetic field. The qubits interact with each other through an Ising interaction of strength J. The paper examines the feasibility of implementing a single-pulse quantum CN gate in an ensemble of quantum molecules at room temperature. We determine a parameter region, ωk and J, in which a single-pulse quantum CN gate can be implemented at room temperature. We also show that there exist characteristic critical values of parameters, Δ ωcr≡| ωk‧ - ωk| cr and Jcr, such that for JJcr and Δ ωk≡| ωk‧ - ωk|<Δ ωcr, non-resonant effects are sufficient to destroy the dynamics required for quantum logic operations.

  16. Non-resonant electromagnetic energy harvester for car-key applications

    Science.gov (United States)

    Li, X.; Hehn, T.; Thewes, M.; Kuehne, I.; Frey, A.; Scholl, G.; Manoli, Y.

    2013-12-01

    This paper presents a novel non-resonant electromagnetic energy harvester for application in a remote car-key, to extend the lifetime of the battery or even to realize a fully energy autonomous, maintenance-free car-key product. Characteristic for a car-key are low frequency and large amplitude motions during normal daily operation. The basic idea of this non-resonant generator is to use a round flat permanent magnet moving freely in a round flat cavity, which is packaged on both sides by printed circuit boards embedded with multi-layer copper coils. The primary goal of this structure is to easily integrate the energy harvester with the existing electrical circuit module into available commercial car-key designs. The whole size of the energy harvester is comparable to a CR2032 coin battery. To find out the best power-efficient and optimal design, several magnets with different dimensions and magnetizations, and various layouts of copper coils were analysed and built up for prototype testing. Experimental results show that with an axially magnetized NdFeB magnet and copper coils of design variant B a maximum open circuit voltage of 1.1V can be observed.

  17. Confocal microlaparoscope for imaging the fallopian tube

    Science.gov (United States)

    Wu, Tzu-Yu; Rouse, Andrew R.; Chambers, Setsuko K.; Hatch, Kenneth D.; Gmitro, Arthur F.

    2014-11-01

    Recent evidence suggests that ovarian cancer can originate in the fallopian tube. Unlike many other cancers, poor access to the ovary and fallopian tubes has limited the ability to study the progression of this deadly disease and to diagnosis it during the early stage when it is most amenable to therapy. A rigid confocal microlaparoscope system designed to image the epithelial surface of the ovary in vivo was previously reported. A new confocal microlaparoscope with an articulating distal tip has been developed to enable in vivo access to human fallopian tubes. The new microlaparoscope is compatible with 5-mm trocars and includes a 2.2-mm-diameter articulating distal tip consisting of a bare fiber bundle and an automated dye delivery system for fluorescence confocal imaging. This small articulating device should enable the confocal microlaparoscope to image early stage ovarian cancer arising inside the fallopian tube. Ex vivo images of animal tissue and human fallopian tube using the new articulating device are presented along with in vivo imaging results using the rigid confocal microlaparoscope system.

  18. Confocal filtering in cathodoluminescence microscopy of nanostructures

    Energy Technology Data Exchange (ETDEWEB)

    Narváez, Angela C., E-mail: a.c.narvaez@tudelft.nl, E-mail: j.p.hoogenboom@tudelft.nl; Weppelman, I. Gerward C.; Moerland, Robert J.; Hoogenboom, Jacob P., E-mail: a.c.narvaez@tudelft.nl, E-mail: j.p.hoogenboom@tudelft.nl; Kruit, Pieter [Imaging Physics, Faculty of Applied Sciences, Delft University of Technology, Lorentzweg 1, 2628CJ Delft (Netherlands)

    2014-06-23

    Cathodoluminescence (CL) microscopy allows optical characterization of nanostructures at high spatial resolution. At the nanoscale, a main challenge of the technique is related to the background CL generated within the sample substrate. Here, we implement confocal detection of the CL signal to minimize the background contribution to the measurement. Nano-phosphors were used as point sources to evaluate the filtering capabilities of our confocal CL system, obtaining an axial intensity profile with 2.7 μm full width at half maximum for the central peak, in good correspondence with theoretical expectations. Considering the electron interaction volume, we found that the confocal filter becomes effective for electron energies above 20 keV, when using a 25 μm pinhole (0.86 Airy units). To illustrate our approach, we present confocal CL imaging of gold nanowires and triangular shaped plates deposited on an indium-tin oxide covered glass substrate, comparing the images with those obtained in standard unfiltered CL detection. The results show that confocal CL microscopy is a valuable tool for the investigation of nanostructures on highly cathodoluminescent substrates, widely used in biological and optical applications.

  19. Development of an inverted NIR-FT-Raman microscope for biomedical applications

    Science.gov (United States)

    Dippel, B.; Tatsch, E.; Schrader, B.

    1997-06-01

    NIR-FT-Raman spectroscopy is the most suitable tool for investigation of biological samples, because the fluorescence of organic substances is reduced to a minimum. To examine the applicability of NIR excited FT-Raman spectroscopy to the study of cell cultures and tissues, measurements were made with an inverted Raman microscope, a modified Zeiss Axiovert 135. This system allows the collection of Raman spectra both by Koehler laser illumination and the confocal principle: • Koehler laser illumination avoids overheating and denaturation of the sample because the exciting laser beam illuminates the sample as an unfocused collimated beam. An integrative collection over the whole image of the microscope objective is necessary to increase the Raman light flux. • The confocal arrangement allows high spatial resolution which is reached by selective collection of the Raman scattering of details of the sample. A larger spatial resolution leads to a decreased light flux of the Raman scattering, this is compensated by a focused laser beam. We have used NIR-FT-Raman spectroscopy to investigate the spectra of normal breast tissues, potentially useful in the diagnosis of cancer.

  20. Spatial heterodyne scanning laser confocal holographic microscopy

    CERN Document Server

    Liu, Changgeng

    2016-01-01

    Scanning laser confocal holographic microscopy using a spatial heterodyne detection method is presented. Spatial heterodyne detection technique employs a Mach-Zehnder interferometer with the reference beam frequency shifted by two acousto-optic modulators (AOM) relative to the object beam frequency. Different from the traditional temporal heterodyne detection technique in which hundreds temporal samples are taken at each scanning point to achieve the complex signal, the spatial heterodyne detection technique generates spatial interference fringes by use of a linear tempo-spatial relation provided by galvanometer scanning in a typical line-scanning confocal microscope or for the slow-scanning on one dimension in a point-scanning confocal microscope, thereby significantly reducing sampling rate and increasing the signal to noise ratio under the same illumination compared to the traditional temporal heterodyne counterpart. The proposed spatial heterodyne detection scheme applies to both line-scanning and point-s...

  1. Spectrally multiplexed chromatic confocal multipoint sensing.

    Science.gov (United States)

    Hillenbrand, Matthias; Lorenz, Lucia; Kleindienst, Roman; Grewe, Adrian; Sinzinger, Stefan

    2013-11-15

    We present a concept for chromatic confocal distance sensing that employs two levels of spectral multiplexing for the parallelized evaluation of multiple lateral measurement points; at the first level, the chromatic confocal principle is used to encode distance information within the spectral distribution of the sensor signal. For lateral multiplexing, the total spectral bandwidth of the sensor is split into bands. Each band is assigned to a different lateral measurement point by a segmented diffractive element. Based on this concept, we experimentally demonstrate a chromatic confocal three-point sensor that is suitable for harsh production environments, since it works with a single-point spectrometer and does not require scanning functionality. The experimental system has a working distance of more than 50 mm, a measurement range of 9 mm, and an axial resolution of 50 μm.

  2. Confocal multiview light-sheet microscopy

    Science.gov (United States)

    Medeiros, Gustavo de; Norlin, Nils; Gunther, Stefan; Albert, Marvin; Panavaite, Laura; Fiuza, Ulla-Maj; Peri, Francesca; Hiiragi, Takashi; Krzic, Uros; Hufnagel, Lars

    2015-01-01

    Selective-plane illumination microscopy has proven to be a powerful imaging technique due to its unsurpassed acquisition speed and gentle optical sectioning. However, even in the case of multiview imaging techniques that illuminate and image the sample from multiple directions, light scattering inside tissues often severely impairs image contrast. Here we combine multiview light-sheet imaging with electronic confocal slit detection implemented on modern camera sensors. In addition to improved imaging quality, the electronic confocal slit detection doubles the acquisition speed in multiview setups with two opposing illumination directions allowing simultaneous dual-sided illumination. Confocal multiview light-sheet microscopy eliminates the need for specimen-specific data fusion algorithms, streamlines image post-processing, easing data handling and storage. PMID:26602977

  3. Confocal Microscopy in Biopsy Proven Argyrosis

    Directory of Open Access Journals (Sweden)

    Melis Palamar

    2013-01-01

    Full Text Available Purpose. To evaluate the confocal microscopy findings of a 46-year-old male with bilateral biopsy proven argyrosis. Materials and Methods. Besides routine ophthalmologic examination, anterior segment photography and confocal microscopy with cornea Rostoch module attached to HRT II (Heidelberg Engineering GmbH, Heidelberg, Germany were performed. Findings. Squamous metaplastic changes on conjunctival epithelium and intense highly reflective extracellular punctiform deposits in conjunctival substantia propria were detected. Corneal epithelium was normal. Highly reflective punctiform deposits starting from anterior to mid-stroma and increasing through Descemet’s membrane were evident. Corneal endothelium could not be evaluated due to intense stromal deposits. Conclusion. Confocal microscopy not only supports diagnosis in ocular argyrosis, but also demonstrates the intensity of the deposition in these patients.

  4. Surface-enhanced Raman spectroscopy on novel black silicon-based nanostructured surfaces

    DEFF Research Database (Denmark)

    Talian, Ivan; Mogensen, Klaus Bo; Orinak, A.;

    2009-01-01

    Two different black silicon nanostructured surfaces modified with thin gold layers were tested for analytical signal enhancement with Surface-Enhanced Raman Spectroscopy (SERS). The relationship between the thicknesses of the gold layers and the analytical signal enhancement was studied. Also......, effects of Ti and Ti/Pt adhesion layers underneath the gold layers on the analytical signal enhancement were tested. An enhancement factor of 7.6 x 10(7) with the excitation laser 785 nm was achieved for the tested analyte, Rhodamine 6G, and non-resonance SER spectra were recorded in a 5 s acquisition...

  5. Line scanning, stage scanning confocal microscope (LSSSCM).

    Science.gov (United States)

    Gareau, Daniel S; Krueger, James G; Hawkes, Jason E; Lish, Samantha R; Dietz, Michael P; Mülberger, Alba Guembe; Mu, Euphemia W; Stevenson, Mary L; Lewin, Jesse M; Meehan, Shane A; Carucci, John A

    2017-08-01

    For rapid pathological assessment of large surgical tissue excisions with cellular resolution, we present a line scanning, stage scanning confocal microscope (LSSSCM). LSSSCM uses no scanning mirrors. Laser light is focused with a single cylindrical lens to a line of diffraction-limited width directly into the (Z) sample focal plane, which is parallel to and near the flattened specimen surface. Semi-confocal optical sections are derived from the linear array distribution (Y) and a single mechanical drive that moves the sample parallel to the focal plane and perpendicular to the focused line (X). LSSSCM demonstrates cellular resolution in the conditions of high nuclear density within micronodular basal cell carcinoma.

  6. Confocal microscopy via multimode fibers: fluorescence bandwidth

    Science.gov (United States)

    Loterie, Damien; Psaltis, Demetri; Moser, Christophe

    2016-03-01

    We recently described a method for confocal reflection imaging through fibers, as a way to increase contrast when imaging unstained biological specimens. Using a transmission matrix, focused spots can be created at the distal end of a fiber. The backscattered field coming back from the sample can be filtered using optical correlation to obtain spatial selectivity in the detection. In this proceedings article, we briefly review the working principle of this method, and we discuss how the scheme could be adapted to confocal fluorescence imaging. In particular, we show simulations of the achievable detection bandwidth when using step-index multimode fibers as imaging devices.

  7. Quantitative coherent anti-Stokes Raman scattering (CARS) microscopy.

    Science.gov (United States)

    Day, James P R; Domke, Katrin F; Rago, Gianluca; Kano, Hideaki; Hamaguchi, Hiro-o; Vartiainen, Erik M; Bonn, Mischa

    2011-06-23

    The ability to observe samples qualitatively at the microscopic scale has greatly enhanced our understanding of the physical and biological world throughout the 400 year history of microscopic imaging, but there are relatively few techniques that can truly claim the ability to quantify the local concentration and composition of a sample. We review coherent anti-Stokes Raman scattering (CARS) as a quantitative, chemically specific, and label-free microscopy. We discuss the complicating influence of the nonresonant response on the CARS signal and the various experimental and mathematical approaches that can be adopted to extract quantitative information from CARS. We also review the uses to which CARS has been employed as a quantitative microscopy to solve challenges in material and biological science.

  8. Raman forward scattering of high-intensity chirped laser pulses

    Energy Technology Data Exchange (ETDEWEB)

    Schroeder, C.B.; Esarey, E.; Shadwick, B.A.; Leemans, W.P.

    2002-06-23

    Raman forward scattering of a high-intensity, short-duration, frequency-chirped laser pulse propagating in an underdense plasma is examined. The growth of the direct forward scattered light is calculated for a laser pulse with a linear frequency chirp in various spatio-temporal regimes. This includes a previously undescribed regime of strongly-coupled four-wave nonresonant interaction, which is important for relativistic laser intensities. In all regimes of forward scattering, it is shown that the growth rate increases (decreases) for positive (negative) frequency chirp. The effect of chirp on the growth rate is relatively minor, i.e., a few percent chirp yields few percent changes in the growth rates. Relation of these results to recent experiments is discussed.

  9. Noninvasive imaging of protein metabolic labeling in single human cells using stable isotopes and Raman microscopy.

    Science.gov (United States)

    van Manen, Henk-Jan; Lenferink, Aufried; Otto, Cees

    2008-12-15

    We have combined nonresonant Raman microspectroscopy and spectral imaging with stable isotope labeling by amino acids in cell culture (SILAC) to selectively detect the incorporation of deuterium-labeled phenylalanine, tyrosine, and methionine into proteins in intact, single HeLa cells. The C-D stretching vibrational bands in these amino acids are observed in the 2100-2300 cm(-1) spectral region that is devoid of vibrational contributions from other, nondeuterated intracellular constituents. We found that incubation with deuterated amino acids for 8 h in cell culture already led to clearly detectable isotope-related signals in Raman spectra of HeLa cells. As expected, the level of isotope incorporation into proteins increased with incubation time, reaching 55% for deuterated phenylalanine after 28 h. Raman spectral imaging of HeLa cells incubated with deuterium-labeled amino acids showed similar spatial distributions for both isotope-labeled and unlabeled proteins, as evidenced by Raman ratio imaging. The SILAC-Raman methodology presented here combines the strengths of stable isotopic labeling of cells with the nondestructive and quantitative nature of Raman chemical imaging and is likely to become a powerful tool in both cell biology applications and research on tissues or whole organisms.

  10. Coherent Raman spectroscopy

    CERN Document Server

    Eesley, G L

    1981-01-01

    Coherent Raman Spectroscopy provides a unified and general account of the fundamental aspects of nonlinear Raman spectroscopy, also known as coherent Raman spectroscopy. The theoretical basis from which coherent Raman spectroscopy developed is described, along with its applications, utility, and implementation as well as advantages and disadvantages. Experimental data which typifies each technique is presented. This book is comprised of four chapters and opens with an overview of nonlinear optics and coherent Raman spectroscopy, followed by a discussion on nonlinear transfer function of matter

  11. Search for BSM decays of SM Higgs and non-resonant di-Higgs results in ATLAS and CMS experiments

    CERN Document Server

    Geng, Cong; The ATLAS collaboration

    2016-01-01

    Report the searches for BSM decays of SM Higgs from ATLAS and CMS results with RUN1 and RUN2 datasets, which includes search for LFV, NMSSM and H to invisible in SM Higgs decays. In this report, I will also report the results of search for non-resonant di-Higgs in ATLAS and CMS.

  12. Second and third peaks in the non-resonant microwave absorption spectra of superconducting Bi2212 crystals

    CSIR Research Space (South Africa)

    Srinivasu, V V

    2010-04-01

    Full Text Available Non-resonant microwave absorption (NMA) measurements at liquid nitrogen temperature with systematic microwave power variation showed a two-peak structure in the Bi-2212 textured crystals, similar to that observed in the Bi-2212 single crystals...

  13. Multinuclear nanoliter one-dimensional and two-dimensional NMR spectroscopy with a single non-resonant microcoil

    NARCIS (Netherlands)

    Fratila, R.M.; Gomez, M.V.; Sykora, S.; Velders, A.H.

    2014-01-01

    Nuclear magnetic resonance (NMR) spectroscopy is a powerful analytical technique, but its low sensitivity and highly sophisticated, costly, equipment severely constrain more widespread applications. Here we show that a non-resonant planar transceiver microcoil integrated in a microfluidic chip (dete

  14. A Confocal Endoscope for Cellular Imaging

    Directory of Open Access Journals (Sweden)

    Jiafu Wang

    2015-09-01

    Full Text Available Since its inception, endoscopy has aimed to establish an immediate diagnosis that is virtually consistent with a histologic diagnosis. In the past decade, confocal laser scanning microscopy has been brought into endoscopy, thus enabling in vivo microscopic tissue visualization with a magnification and resolution comparable to that obtained with the ex vivo microscopy of histological specimens. The major challenge in the development of instrumentation lies in the miniaturization of a fiber-optic probe for microscopic imaging with micron-scale resolution. Here, we present the design and construction of a confocal endoscope based on a fiber bundle with 1.4-μm lateral resolution and 8-frames per second (fps imaging speed. The fiber-optic probe has a diameter of 2.6 mm that is compatible with the biopsy channel of a conventional endoscope. The prototype of a confocal endoscope has been used to observe epithelial cells of the gastrointestinal tracts of mice and will be further demonstrated in clinical trials. In addition, the confocal endoscope can be used for translational studies of epithelial function in order to monitor how molecules work and how cells interact in their natural environment.

  15. Confocal microscopy imaging of solid tissue

    Science.gov (United States)

    Confocal laser scanning microscopy (CLSM) is a technique that is capable of generating serial sections of whole-mount tissue and then reassembling the computer acquired images as a virtual 3-dimensional structure. In many ways CLSM offers an alternative to traditional sectioning ...

  16. Confocal Microscopy Imaging of the Biofilm Matrix

    DEFF Research Database (Denmark)

    Schlafer, Sebastian; Meyer, Rikke Louise

    2016-01-01

    The extracellular matrix is an integral part of microbial biofilms and an important field of research. Confocal laser scanning microscopy is a valuable tool for the study of biofilms, and in particular of the biofilm matrix, as it allows real-time visualization of fully hydrated, living specimens...... the concentration of solutes and the diffusive properties of the biofilm matrix....

  17. Coherent control of non-resonant two-photon transition in molecular system

    Institute of Scientific and Technical Information of China (English)

    Zhang Hui; Zhang Shi-An; Wang Zu-Geng; Sun Zhen-Rong

    2010-01-01

    In this paper,we study theoretically and experimentally the coherent control of non-resonant two-photon transition in a molecular system (Perylene dissolved in chloroform solution) by shaping the femtosecond pulses with simple phase patterns (cosinusoidal and π phase step-function shape).The control efficiency of the two-photon transition probability is correlated with both the laser field and the molecular absorption bandwidth.Our results demonstrate that,the two-photon transition probability in a molecular system can be reduced but not completely eliminated by manipulating the laser field,and the control efficiency is minimal when the molecular absorption bandwidth is larger than twice the laser spectral bandwidth.

  18. Relativistic calculations of the non-resonant two-photon ionization of neutral atoms

    CERN Document Server

    Hofbrucker, Jiri; Fritzsche, Stephan

    2016-01-01

    The non-resonant two-photon one-electron ionization of neutral atoms is studied theoretically in the framework of relativistic second-order perturbation theory and independent particle approximation. In particular, the importance of relativistic and screening effects in the total two-photon ionization cross section is investigated. Detailed computations have been carried out for the K-shell ionization of neutral Ne, Ge, Xe, and U atoms. The relativistic effects significantly decrease the total cross section, for the case of U, for example, they reduce the total cross section by a factor of two. Moreover, we have found that the account for the screening effects of the remaining electrons leads to occurrence of an unexpected minimum in the total cross section at the total photon energies equal to the ionization threshold, for the case of Ne, for example, the cross section drops there by a factor of three.

  19. Anomalous non-resonant microwave absorption in SmFeAs(O,F) polycrystalline sample

    Science.gov (United States)

    Onyancha, R. B.; Shimoyama, J.; Singh, S. J.; Hayashi, K.; Ogino, H.; Srinivasu, V. V.

    2017-02-01

    Here we present the non-resonant microwave absorption (NRMA) studies on SmFeAsO0.88F0.12 polycrystalline sample measured at 6.06 K with the magnetic field swept from -250 G to +250 G at a frequency of 9.45 GHz. It was observed that the (NRMA) line shape evolves as a function of microwave power. Again, the signal intensity increases from 22.83 μW to 0.710 mW where it reaches a maximum and quite remarkably it changed from 'normal' absorption to 'anomalous' absorption at 2.247 mW, then the intensity decreases with further increase of microwave power. The crossover from 'normal' to 'anomalous' NRMA absorption and its dependence on microwave power is a new phenomenon in iron pnictides superconductors and we have attributed this anomaly to come from non-hysteretic Josephson junction.

  20. Adiabatic Non-resonant Acceleration in Magnetic Turbulence and Hard Spectra of Gamma-Ray Bursts

    Science.gov (United States)

    Xu, Siyao; Zhang, Bing

    2017-09-01

    We introduce a non-resonant acceleration mechanism arising from the second adiabatic invariant in magnetic turbulence and apply it to study the prompt emission spectra of gamma-ray bursts (GRBs). The mechanism contains both the first- and second-order Fermi acceleration, originating from the interacting turbulent reconnection and dynamo processes. It leads to a hard electron energy distribution up to a cutoff energy at the balance between the acceleration and synchrotron cooling. The sufficient acceleration rate ensures a rapid hardening of any initial energy distribution to a power-law distribution with the index p∼ 1, which naturally produces a low-energy photon index α ∼ -1 via the synchrotron radiation. For typical GRB parameters, the synchrotron emission can extend to a characteristic photon energy on the order of ∼100 keV.

  1. Resonant and non-resonant X-ray scattering from GdB{sub 6}

    Energy Technology Data Exchange (ETDEWEB)

    Kuwahara, K. [Department of Physics, Faculty of Science, Tokyo Metropolitan University, Hachioji, Tokyo 192-0397 (Japan)]. E-mail: kuwahara@phys.metro-u.ac.jp; Yamamoto, R. [Department of Physics, Faculty of Science, Tokyo Metropolitan University, Hachioji, Tokyo 192-0397 (Japan); Kohgi, M. [Department of Physics, Faculty of Science, Tokyo Metropolitan University, Hachioji, Tokyo 192-0397 (Japan); Nakao, H. [Faculty of Science, Tohoku University, Sendai 980-8577 (Japan); Ishii, K. [Synchrotron Radiation Research Center, JAERI, Hyogo 679-5148 (Japan); Iwasa, K. [Faculty of Science, Tohoku University, Sendai 980-8577 (Japan); Murakami, Y. [Faculty of Science, Tohoku University, Sendai 980-8577 (Japan); Kunii, S. [Faculty of Science, Tohoku University, Sendai 980-8577 (Japan); Sagayama, H. [Photon Factory, Institute for Materials Structure Science, KEK, Tsukuba 305-0801 (Japan); Wakabayashi, Y. [Photon Factory, Institute for Materials Structure Science, KEK, Tsukuba 305-0801 (Japan); Sawa, H. [Photon Factory, Institute for Materials Structure Science, KEK, Tsukuba 305-0801 (Japan)

    2005-04-30

    We have performed resonant and non-resonant X-ray scattering on GdB{sub 6} to investigate the two successive phase transitions at T{sub N}={approx}15K and T*={approx}10K. Below T{sub N}, new superlattice reflection at the wave vector [141412], which is the same wave vector determined by the epithermal neutron diffraction, has been observed by X-ray scattering. In the temperature region between T* and T{sub N}, it was confirmed by the polarization analyses that the superlattice reflection is due to magnetic X-ray scattering. On the other hand, interestingly, the superlattice reflection below T* is mainly due to Thomson scattering. Unlike behavior expected from usual magnetoelastic effects, the wave vector of the lattice distortion is identical to that of the magnetic structure below T*.

  2. Optical solitons in resonant and nonresonant nonlinear media in the presence of perturbations.

    Science.gov (United States)

    Piscureanu, M; Manaila-Maximean, D

    2000-01-01

    We studied the optical solitons in nonlinear resonant and nonresonant media in the presence of perturbations, assuming that the transient effects are stimulated by the light scanning beam. We treated a slight deviation from the exact necessary condition for the soliton existence (2betanu=1), as a small perturbation for the integrable system, studying its influence upon the soliton propagation conditions. The approximation is constructed by the help of an algebraic version of the soliton perturbation theory using a Riemann boundary problem in connection with the inverse scattering method. We have obtained the soliton equation and we have solved it in the presence of a small perturbation in the adiabatic approximation. In this case we have demonstrated that for a Lorentz profile line the amplitude of the soliton remains unchanged, the only effect of the perturbation results in a phase shift.

  3. Nonresonant Saturation Absorption in Electrostatic Self-Assembly Films Containing Methanofullerene

    Institute of Scientific and Technical Information of China (English)

    ZHANG Xue-Ru; OUYANG Qiu-Yun; WANG Yu-Xiao; JIANG Li; SONG Ying-Lin; LI Yu-Liang; WEI Tai-Huei

    2005-01-01

    @@ Ultrathin films containing methaofullerene are prepared by electrostatic layer-by-layer self-assembly of a positivelycharged trifluoroacetic acid salt of monoamino-substituted methanofullerene (TMAF) derivative and a negatively charged poly (sodium 4-styrenesulfonate) (PSS). Absorptive optical nonlinearities of 30 bilayer TMAF/PSS films and TMAF in water solution are measured using the Z-scan technique at 532nm. Nonresonant saturation absorption is observed in the film sample, whereas reverse saturation absorption was for TMAF in water. The saturation-absorption behaviour is interpreted by a special formula. The saturation intensity is extracted to be 15.2 ± 0.8 MW/cm2. The mechanism of saturation absorption in the TMAF/PSS film is discussed.

  4. Attenuation of Scintillation of Discrete Cosmic Sources during Nonresonant HF Heating of the Upper Ionosphere

    Science.gov (United States)

    Bezrodny, V. G.; Watkins, B.; Charkina, O. V.; Yampolski, Y. M.

    2014-03-01

    The aim of the work is to experimentally investigate the response of scintillation spectra and indices of discrete cosmic sources (DCS) to modification of the ionospheric F-region by powerful electromagnetic fields with frequencies exceeding the Langmuir and upper hybrid ones. The results of a special experiment on the scintillations of radiation from DCS Cygnus A observed with using the 64-beam imaging riometer located near the Gakona village (Alaska, USA) are here presented. The ionosphere was artificially disturbed by powerful HAARP heater. Under the studied conditions of nonresonant heating of the ionospheric plasma, an earlier unknown effect of reducing the level of DCS scintillation was discovered. The theoretical interpretation has been given for the discovered effect, which using allowed the proposed technique of solving the inverse problem (recovery deviations of average electron density and temperature in the modified region from their unperturbed values).

  5. Non-resonant four-body decay of $B \\to D^- \\pi^+\\pi^+\\pi^- $

    CERN Document Server

    Talebtash, Mohammad Rahim

    2015-01-01

    We calculate the branching ratio of the non-resonant $B \\to D^- \\pi^+\\pi^+\\pi^- $ decay using a simple model based on the framework of the factorization approach. In naive factorization approach, there are only tow tree diagrams for this decay mode. In the first diagram, the matrix element of decay mode is factorized into a $B\\to D$ form factor multiplied by a $3\\pi$ decay constant and in the second diagram, the matrix element is factorized into a $B\\to D\\pi$ form factor multiplied by a $2\\pi$ decay constant, We assume that in the rest frame of B meson, the $D$ meson remains stationary, so we obtain the value $(3.47\\pm0.14)\\times 10^{-3}$ for the branching ration of the $B \\to D^- \\pi^+\\pi^+\\pi^- $ decay mode, while the experimental results are $(3.9\\pm1.9)\\times10^{-3}$.

  6. Bearing fault identification by higher order energy operator fusion: A non-resonance based approach

    Science.gov (United States)

    Faghidi, H.; Liang, M.

    2016-10-01

    We report a non-resonance based approach to bearing fault detection. This is achieved by a higher order energy operator fusion (HOEO_F) method. In this method, multiple higher order energy operators are fused to form a single simple transform to process the bearing signal obscured by noise and vibration interferences. The fusion is guided by entropy minimization. Unlike the popular high frequency resonance technique, this method does not require the information of resonance excited by the bearing fault. The effects of the HOEO_F method on signal-to-noise ratio (SNR) and signal-to-interference ratio (SIR) are illustrated in this paper. The performance of the proposed method in handling noise and interferences has been examined using both simulated and experimental data. The results indicate that the HOEO_F method outperforms both the envelope method and the original energy operator method.

  7. Transition from non-resonant to resonant random lasers by the geometrical confinement of disorder

    CERN Document Server

    Ghofraniha, N; Zacheo, A; Arima, V; Gigli, G; Conti, C

    2014-01-01

    We report on a novel kind of transition in random lasers induced by the geometrical confinement of the emitting material. Different dye doped paper devices with controlled geometry are fabricated by soft-lithography and show two distinguished behaviors in the stimulated emission: in the absence of boundary constraints the energy threshold decreases for larger laser volumes showing the typical trend of diffusive {\\it non-resonant} random lasers, while when the same material in lithographed into channels, the walls act as cavity and the {\\it resonant} behavior typical of standard lasers is observed. The experimental results are consistent with the general theories of random and standard lasers and a clear phase diagram of the transition is reported.

  8. Phase-Modulated Nonresonant Laser Pulses Can Selectively Convert Enantiomers in a Racemic Mixture

    DEFF Research Database (Denmark)

    Thomas, Esben Folger; Henriksen, Niels Engholm

    2017-01-01

    Deracemization occurs when a racemic molecular mixture is transformed into a mixture containing an excess of a single enantiomer. Recent advances in ultrafast laser technology hint at the possibility of using shaped pulses to generate deracemization via selective enantiomeric conversion; however......-modulated, nonresonant, linearly polarized Gaussian laser pulses that can selectively deracemize a racemic mixture of 3D-oriented, 3,5-difluoro-3',5'-dibromobiphenyl (F2H3C6-C6H3Br2) molecules, the laser-induced dynamics of which are well studied experimentally. These results strongly suggest that designing a closed......-loop coherent control scheme based on this methodology may lead to the first-ever achievement of enantiomeric conversion via coherent laser light in a laboratory setting....

  9. Rotational dynamics of an asymmetric top molecule in parallel electric and non-resonant laser fields

    CERN Document Server

    Omiste, Juan J

    2013-01-01

    We present a theoretical study of the rotational dynamics of asymmetry top molecules in parallel electric field and non-resonant linearly polarized laser pulses. The time-dependent Schr\\"odinger equation is solved within the the rigid rotor approximation. Using the benzonitrile molecule as prototype, we investigate the field-dressed dynamics for experimentally accessible field configurations and compare these results to the adiabatic predictions. We show that for an asymmetric top molecule in parallel fields, the formation of the pendular doublets and the avoided crossings between neighboring levels are the two main sources of non-adiabatic effects. We also provide the field parameters under which the adiabatic dynamics would be achieved.

  10. Nonresonant tunneling phonon depopulated GaN based terahertz quantum cascade structures

    Science.gov (United States)

    Freeman, Will; Karunasiri, Gamani

    2013-04-01

    GaN based terahertz quantum cascade structures are theoretically studied. Since the Fröhlich interaction is ˜15 times higher in GaN than in GaAs, level broadening makes obtaining appreciable optical gain difficult even with a large population inversion. A density matrix Monte Carlo method is used to calculate the broadening of the optical gain spectra as a function of lattice temperature. We find by using a proposed method of nonresonant tunneling and electron-longitudinal-optical phonon scattering for depopulation of the lower lasing state, that it is possible to sufficiently isolate the upper lasing state and control the lower lasing state lifetime to obtain high optical gain in GaN. The results predict lasing out to 300 K which is significantly higher than for GaAs based structures.

  11. Resonant and non-resonant whistlers-particle interaction in the radiation belts

    CERN Document Server

    Camporeale, Enrico

    2014-01-01

    We study the wave-particle interactions between lower band chorus whistlers and an anisotropic tenuous population of relativistic electrons. We present the first direct comparison of first-principle Particle-in-Cell (PIC) simulations with a quasi-linear diffusion code, in this context. In the PIC approach, the waves are self-consistently generated by a temperature anisotropy instability that quickly saturates and relaxes the system towards marginal stability. We show that the quasi-linear diffusion and PIC results have significant quantitative mismatch in regions of energy/pitch angle where the resonance condition is not satisfied. Moreover, for pitch angles close to the loss cone the diffusion code overestimates the scattering, particularly at low energies. This suggest that higher order nonlinear theories should be taken in consideration in order to capture non-resonant interactions, resonance broadening, and to account for scattering at angles close to $90^\\circ$.

  12. Low-field non-resonant microwave absorption in glass-coated Co-rich microwires

    Energy Technology Data Exchange (ETDEWEB)

    Valenzuela, Raul; Alvarez, Guillermo [Depto. de Materiales Metalicos y Ceramicos, Universidad Nacional Autonoma de Mexico, Mexico D.F. 04510 (Mexico); Montiel, Herlinda [Depto. de Tecnociencias, Centro de Ciencias Aplicadas y Desarrollo Tecnologico, Universidad Nacional Autonoma de Mexico (Mexico); Zamorano, Rafael [Depto. de Ciencias de Materiales, Escuela Superior de Fisica y Matematicas, Instituto Politecnico Nacional, Mexico D.F. (Mexico)

    2009-04-15

    A study of low-field non-resonant microwave absorption (LFA) at 9.8 GHz, on as-cast amorphous Co-rich CoFeBSi microwires under different measuring geometries is presented. Results confirm that LFA is associated with the magnetization processes from the unmagnetized state (H{sub DC}=0) to the saturated condition, in many aspects similar to Giant Magnetoimpedance (GMI), and clearly different from ferromagnetic resonance (FMR). LFA signal showed large variations in its maximum-minimum separation as a function of the measuring geometry, which is interpreted in terms of the total anisotropy in the process. (copyright 2009 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  13. Discriminant Analysis of Raman Spectra for Body Fluid Identification for Forensic Purposes

    Directory of Open Access Journals (Sweden)

    Vitali Sikirzhytski

    2010-03-01

    Full Text Available Detection and identification of blood, semen and saliva stains, the most common body fluids encountered at a crime scene, are very important aspects of forensic science today. This study targets the development of a nondestructive, confirmatory method for body fluid identification based on Raman spectroscopy coupled with advanced statistical analysis. Dry traces of blood, semen and saliva obtained from multiple donors were probed using a confocal Raman microscope with a 785-nm excitation wavelength under controlled laboratory conditions. Results demonstrated the capability of Raman spectroscopy to identify an unknown substance to be semen, blood or saliva with high confidence.

  14. Phase transition and Raman-active modes in TlInS{sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    Paucar, Raul; Harada, Kazuki; Matsumoto, Ryoya; Wakita, Kazuki [Electronics and Computer Engineering, Chiba Institute of Technology, Chiba (Japan); Shim, YongGu [Graduate School of Engineering, Osaka Prefecture University, Osaka (Japan); Alekperov, Oktay; Mamedov, Nazim [Institute of Physics, Azerbaijan National Academy of Sciences, Baku (Azerbaijan)

    2013-08-15

    Raman spectra of layered ternary thallium chalcogenide TlInS{sub 2}were studied with the aid of 3D confocal Raman system over the temperature range 77-300K in the frequency region of 120-400 cm{sup -1}. The observed lines in the obtained Raman spectra were denconvoluted into Lorentzian peaks and temperature dependence of each peak's parameters (peak position and half width at half maximum) were obtained. An irregular behaviour of the temperature dependence of Lorentzian parameters is reported. (copyright 2013 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  15. An accurate analytic representation of the temperature dependence of nonresonant nuclear reaction rate coefficients

    Science.gov (United States)

    Shizgal, Bernie D.

    2016-12-01

    There has been intense interest for several decades by different research groups to accurately model the temperature dependence of a large number of nuclear reaction rate coefficients for both light and heavy nuclides. The rate coefficient, k(T) , is given by the Maxwellian average of the reactive cross section expressed in terms of the astrophysical factor, S(E) , which for nonresonant reactions is generally written as a power series in the relative energy E. A computationally efficient algorithm for the temperature dependence of nuclear reaction rate coefficients is required for fusion reactor research and for models of nucleosynthesis and stellar evolution. In this paper, an accurate analytical expression for the temperature dependence of nuclear reaction rate coefficients is provided in terms of τ = 3(b / 2) 2/3 or equivalently, T - 1/3 , where b = B /√{kB T }, B is the Gamow factor and kB is the Boltzmann constant. The methodology is appropriate for all nonresonant nuclear reactions for which S(E) can be represented as a power series in E. The explicit expression for the rate coefficient versus temperature is derived with the asymptotic expansions of the moments of w(E) = exp(- E /kB T - B /√{ E }) in terms of τ. The zeroth order moment is the familiar Gaussian approximation to the rate coefficient. Results are reported for the representative reactions D(d, p)T, D(d, n)3He and 7Li(p, α) α and compared with several different fitting procedures reported in the literature.

  16. Raman spectra of single cell from gastrointestinal cancer patients

    Institute of Scientific and Technical Information of China (English)

    Xun-Ling Yan; Rui-Xin Dong; Lei Zhang; Xue-Jun Zhang; Zong-Wang Zhang

    2005-01-01

    AIM: To explore the difference between cancer cells and normal cells, we investigated the Raman spectra of singlecells from gastrointestinal cancer patients. METHODS: All samples were obtained from 30 diagnosed as gastrointestinal cancer patients. The flesh tumor specimen is located in the center of tumor tissue, while the normal ones were 5 cm away from the outside tumor section. The imprint was put under the microscope and a single cell was chosen for Raman measurement. All spectra were collected at confocal Raman micro-spectroscopy (British Renishaw) with NIR 780 nm laser.RESULTS: We measured the Raman spectra of several cells from gastrointestinal cancer patients. The result shows that there exists the strong line at 1 002/cm with less half-width assigned to the phenylalanine in several cells. The Raman lines of white cell were lower and less, while those of red cell were not only higher in intensity and more abundant, but also had a parti cular C-N breathing stretching band of pyrrole ring at 1 620-1 540/cm. The line at 1 084/cm assigned to phosphate backbone of DNA became obviously weaker in cancer cell. The Raman spectra of stomach cancer cells were similar to those of normal cells, but the Raman intensity of cancer cells was much lower than that of normal cells, and even some lines disappear. The lines of enteric cancer cells became weaker than spectra above and many lines disappeared, and the cancer cells in different position had different fluorescence intensity.CONCLUSION: The Raman spectra of several cells from cancer patients show that the structural changes of cancer cells happen and many bonds rupture so that the biological function of cells are lost. The results indicate that Raman spectra can offer the experiment basis for the cancer diagnosis and treatment.

  17. Raman Sensitive Degradation and Etching Dynamics of Exfoliated Black Phosphorus

    Science.gov (United States)

    Alsaffar, Fadhel; Alodan, Sarah; Alrasheed, Abdul; Alhussain, Abdulrahman; Alrubaiq, Noura; Abbas, Ahmad; Amer, Moh. R.

    2017-01-01

    Layered black phosphorus has drawn much attention due to the existence of a band gap compared to the widely known graphene. However, environmental stability of black phosphorus is still a major issue, which hinders the realization of practical device applications. Here, we spatially Raman map exfoliated black phosphorus using confocal fast-scanning technique at different time intervals. We observe a Raman intensity modulation for , B2g, and modes. This Raman modulation is found to be caused by optical interference, which gives insights into the oxidation mechanism. Finally, we examine the fabrication compatible PMMA coating as a viable passivation layer. Our measurements indicate that PMMA passivated black phosphorus thin film flakes can stay pristine for a period of 19 days when left in a dark environment, allowing sufficient time for further nanofabrication processing. Our results shed light on black phosphorus degradation which can aid future passivation methods. PMID:28317834

  18. Combining Portable Raman Probes with Nanotubes for Theranostic Applications

    Directory of Open Access Journals (Sweden)

    Ashwinkumar A. Bhirde, Gang Liu, Albert Jin, Ramiro Iglesias-Bartolome, Alioscka A. Sousa, Richard D. Leapman, J. Silvio Gutkind, Seulki Lee, Xiaoyuan Chen

    2011-01-01

    Full Text Available Recently portable Raman probes have emerged along with a variety of applications, including carbon nanotube (CNT characterization. Aqueous dispersed CNTs have shown promise for biomedical applications such as drug/gene delivery vectors, photo-thermal therapy, and photoacoustic imaging. In this study we report the simultaneous detection and irradiation of carbon nanotubes in 2D monolayers of cancer cells and in 3D spheroids using a portable Raman probe. A portable handheld Raman instrument was utilized for dual purposes: as a CNT detector and as an irradiating laser source. Single-walled carbon nanotubes (SWCNTs and multi-walled carbon nanotubes (MWCNTs were dispersed aqueously using a lipid-polymer (LP coating, which formed highly stable dispersions both in buffer and cell media. The LP coated SWCNT and MWCNT aqueous dispersions were characterized by atomic force microscopy, transmission electron microscopy, dynamic light scattering, Fourier transform infrared spectroscopy and Raman spectroscopy. The cellular uptake of the LP-dispersed SWCNTs and MWCNTs was observed using confocal microscopy, and fluorescein isothiocyanate (FITC-nanotube conjugates were found to be internalized by ovarian cancer cells by using Z-stack fluorescence confocal imaging. Biocompatibility of SWCNTs and MWCNTs was assessed using a cell viability MTT assay, which showed that the nanotube dispersions did not hinder the proliferation of ovarian cancer cells at the dosage tested. Ovarian cancer cells treated with SWCNTs and MWCNTs were simultaneously detected and irradiated live in 2D layers of cancer cells and in 3D environments using the portable Raman probe. An apoptotic terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL assay carried out after laser irradiation confirmed that cell death occurred only in the presence of nanotube dispersions. We show for the first time that both SWCNTs and MWCNTs can be selectively irradiated and detected in cancer cells

  19. Ab initio study of coherent anti-Stokes Raman scattering (CARS) of the 1,3,5-trinitro-1,3,5-triazacyclohexane (RDX) explosive

    Science.gov (United States)

    Mohammed, Abdelsalam; Ågren, Hans; Thorvaldsen, Andreas J.; Ruud, Kenneth

    2010-01-01

    Coherent anti-Stokes Raman scattering (CARS) of the 1,3,5-trinitro-1,3,5-triazacyclohexane (RDX) C 3H 6N 6O 6 molecule is studied by ab initio methods. The results are compared to available experimental observations and against calculations and experimental observations of the conventional non-resonant Raman spectrum for RDX. It is found that all intense bands in the observed CARS spectrum and all Raman differential cross sections are well reproduced by the calculations. The features of the resonant CARS signal vary strongly from the corresponding Raman signal, and are obtained with a considerably larger cross section, a fact that could further facilitate the use of CARS spectroscopy in applications of stand-off detection of gaseous samples at ultra-low concentrations.

  20. Diagnosis of Multiple Gases Separated from Transformer Oil Using Cavity-Enhanced Raman Spectroscopy

    Institute of Scientific and Technical Information of China (English)

    LI Xiao-Yun; XIA Yu-Xing; HUANG Ju-Ming; ZHAN Li

    2008-01-01

    The Raman signal of gas molecules is very weak due to its small scattering cross section. Here, a near-confocal cavity-enhanced Raman detection system is demonstrated. In the cavity, a high power light of 9 W is achieved by using a cw 200mW 532nm laser, which greatly enhances the detection sensitivity of gas species. A photomultiplier tube connected to a spectrometer is used as the detection system. The Raman spectra of the mixed gases separated from transformer oil has been observed. The relationship of absolute Raman intensity and gas pressure is also obtained. To our knowledge, this is the first Raman system to detect the gases separated from transformer oil.

  1. Confocal microscopy imaging of the biofilm matrix.

    Science.gov (United States)

    Schlafer, Sebastian; Meyer, Rikke L

    2017-07-01

    The extracellular matrix is an integral part of microbial biofilms and an important field of research. Confocal laser scanning microscopy is a valuable tool for the study of biofilms, and in particular of the biofilm matrix, as it allows real-time visualization of fully hydrated, living specimens. Confocal microscopes are held by many research groups, and a number of methods for qualitative and quantitative imaging of the matrix have emerged in recent years. This review provides an overview and a critical discussion of techniques used to visualize different matrix compounds, to determine the concentration of solutes and the diffusive properties of the biofilm matrix. Copyright © 2016 Elsevier B.V. All rights reserved.

  2. Practical aspects of quantitative confocal microscopy.

    Science.gov (United States)

    Murray, John M

    2013-01-01

    Confocal microscopes are in principle well suited for quantitative imaging. The 3D fluorophore distribution in a specimen is transformed by the microscope optics and detector into the 2D intensity distribution of a digital image by a linear operation, a convolution. If multiple 2D images of the specimen at different focal planes are obtained, then the original 3D distribution in the specimen can be reconstructed. This reconstruction is a low-pass spatially filtered representation of the original, but quantitatively preserves relative fluorophore concentrations, with of course some limitations on accuracy and precision due to aberrations and noise. Given appropriate calibration, absolute fluorophore concentrations are accessible. A few simple guidelines are given for setting up confocal microscopes and checking their performance. With a little care, the images collected should be suitable for most types of quantitative analysis.

  3. Digital confocal microscopy through a multimode fiber

    CERN Document Server

    Loterie, Damien; Papadopoulos, Ioannis; Goy, Alexandre; Psaltis, Demetri; Moser, Christophe

    2015-01-01

    Acquiring high-contrast optical images deep inside biological tissues is still a challenging issue. Confocal microscopy is an important tool for biomedical imaging since it improves image quality by rejecting background signals. On the other hand, it suffers from low sensitivities in deep tissues due to light scattering. Recently, multimode fibers have provided a new paradigm for minimally invasive endoscopic imaging by controlling light propagation through them. Here we introduce a combined imaging technique where confocal images of a human epithelial cell are acquired through a multimode fiber. We achieve this by digitally engineering the excitation wavefront and then applying a virtual digital pinhole on the collected signal. In this way, we are able to acquire images through the fiber with significantly increased contrast.

  4. Raman scattering enhancement in photon-plasmon resonance mediated metal-dielectric microcavity

    Science.gov (United States)

    Guddala, Sriram; Dwivedi, Vindesh K.; Vijaya Prakash, G.; Narayana Rao, D.

    2013-12-01

    Here, we report the photon-plasmon interaction scheme and enhanced field strengths resulted into the amplification of phonon in a novel microcavity. A metal-dielectric microcavity, with unified cavity photonic mode and localized surface plasmon resonances, is visualized by impregnating the gold nanoparticles into the deep see-through nano-sized pores of porous silicon microcavity. The intense optical field strengths resulting from the photon-plasmon interactions are probed by both resonant and non-resonant Raman scattering experiments. Due to photon-plasmon-phonon interaction mechanism, several orders of enhancement in the intensity of scattered Raman Stokes photon (at 500 cm-1) are observed. Our metal nanoparticle-microcavity hybrid system shows the potential to improve the sensing figure of merit as well as the applications of plasmonics for optoelectronics, photovoltaics, and related technologies.

  5. Raman scattering enhancement in photon-plasmon resonance mediated metal-dielectric microcavity

    Energy Technology Data Exchange (ETDEWEB)

    Guddala, Sriram; Narayana Rao, D., E-mail: dnr.laserlab@gmail.com, E-mail: dnrsp@uohyd.ernet.in [School of Physics, University of Hyderabad, Hyderabad 500 046 (India); Dwivedi, Vindesh K.; Vijaya Prakash, G. [Nanophotonics Laboratory, Department of Physics, IIT Delhi, New Delhi 110 016 (India)

    2013-12-14

    Here, we report the photon-plasmon interaction scheme and enhanced field strengths resulted into the amplification of phonon in a novel microcavity. A metal-dielectric microcavity, with unified cavity photonic mode and localized surface plasmon resonances, is visualized by impregnating the gold nanoparticles into the deep see-through nano-sized pores of porous silicon microcavity. The intense optical field strengths resulting from the photon-plasmon interactions are probed by both resonant and non-resonant Raman scattering experiments. Due to photon-plasmon-phonon interaction mechanism, several orders of enhancement in the intensity of scattered Raman Stokes photon (at 500 cm{sup −1}) are observed. Our metal nanoparticle-microcavity hybrid system shows the potential to improve the sensing figure of merit as well as the applications of plasmonics for optoelectronics, photovoltaics, and related technologies.

  6. In Situ and In Vivo Molecular Analysis by Coherent Raman Scattering Microscopy

    Science.gov (United States)

    Liao, Chien-Sheng; Cheng, Ji-Xin

    2016-06-01

    Coherent Raman scattering (CRS) microscopy is a high-speed vibrational imaging platform with the ability to visualize the chemical content of a living specimen by using molecular vibrational fingerprints. We review technical advances and biological applications of CRS microscopy. The basic theory of CRS and the state-of-the-art instrumentation of a CRS microscope are presented. We further summarize and compare the algorithms that are used to separate the Raman signal from the nonresonant background, to denoise a CRS image, and to decompose a hyperspectral CRS image into concentration maps of principal components. Important applications of single-frequency and hyperspectral CRS microscopy are highlighted. Potential directions of CRS microscopy are discussed.

  7. Resonant Raman scattering theory for Kitaev models and their Majorana fermion boundary modes

    Science.gov (United States)

    Perreault, Brent; Knolle, Johannes; Perkins, Natalia B.; Burnell, F. J.

    2016-09-01

    We study the inelastic light scattering response in two- (2D) and three-dimensional (3D) Kitaev spin-liquid models with Majorana spinon band structures in the symmetry classes BDI and D leading to protected gapless surface modes. We present a detailed calculation of the resonant Raman/Brillouin scattering vertex relevant to iridate and ruthenate compounds whose low-energy physics is believed to be proximate to these spin-liquid phases. In the symmetry class BDI, we find that while the resonant scattering on thin films can detect the gapless boundary modes of spin liquids, the nonresonant processes do not couple to them. For the symmetry class D, however, we find that the coupling between both types of light-scattering processes and the low-energy surface states is strongly suppressed. Additionally, we describe the effect of weak time-reversal symmetry breaking perturbations on the bulk Raman response of these systems.

  8. Raman Spectra of Glasses

    Science.gov (United States)

    1986-11-30

    17), Raman spectra, plus a , . theoretical treatment of the data, f complex fluorozirconate 14 I anions in ZBLAN glasses and melts (16), and...based ZBLAN glasses ) 17. ICORS (International Conference on Raman Spectroscopy) Proceedings, London, England. Conferencf 5-9 Sep 88. (Molten silica...RESEARCH FINAL REPORT DTIC CONTRACT N00014-81-K-0501 &JELECTE 1 MAY 81 -- 30 NOV 86 EJJAN041989 V "RAMAN SPECTRA OF GLASSES " 0 During the five years of the

  9. A near-infrared confocal scanner

    Science.gov (United States)

    Lee, Seungwoo; Yoo, Hongki

    2014-06-01

    In the semiconductor industry, manufacturing of three-dimensional (3D) packages or 3D integrated circuits is a high-performance technique that requires combining several functions in a small volume. Through-silicon vias, which are vertical electrical connections extending through a wafer, can be used to direct signals between stacked chips, thus increasing areal density by stacking and connecting multiple patterned chips. While defect detection is essential in the semiconductor manufacturing process, it is difficult to identify defects within a wafer or to monitor the bonding results between bonded surfaces because silicon and many other semiconductor materials are opaque to visible wavelengths. In this context, near-infrared (NIR) imaging is a promising non-destructive method to detect defects within silicon chips, to inspect bonding between chips and to monitor the chip alignment since NIR transmits through silicon. In addition, a confocal scanner provides high-contrast, optically-sectioned images of the specimen due to its ability to reject out-of-focus noise. In this study, we report an NIR confocal scanner that rapidly acquires high-resolution images with a large field of view through silicon. Two orthogonal line-scanning images can be acquired without rotating the system or the specimen by utilizing two orthogonally configured resonant scanning mirrors. This NIR confocal scanner can be efficiently used as an in-line inspection system when manufacturing semiconductor devices by rapidly detecting defects on and beneath the surface.

  10. Clinical applications of corneal confocal microscopy

    Directory of Open Access Journals (Sweden)

    Mitra Tavakoli

    2008-06-01

    Full Text Available Mitra Tavakoli1, Parwez Hossain2, Rayaz A Malik11Division of Cardiovascular Medicine, University of Manchester and Manchester Royal Infirmary, Manchester, UK; 2University of Southampton, Southampton Eye Unit, Southampton General Hospital, Southampton, UKAbstract: Corneal confocal microscopy is a novel clinical technique for the study of corneal cellular structure. It provides images which are comparable to in-vitro histochemical techniques delineating corneal epithelium, Bowman’s layer, stroma, Descemet’s membrane and the corneal endothelium. Because, corneal confocal microscopy is a non invasive technique for in vivo imaging of the living cornea it has huge clinical potential to investigate numerous corneal diseases. Thus far it has been used in the detection and management of pathologic and infectious conditions, corneal dystrophies and ecstasies, monitoring contact lens induced corneal changes and for pre and post surgical evaluation (PRK, LASIK and LASEK, flap evaluations and Radial Keratotomy, and penetrating keratoplasty. Most recently it has been used as a surrogate for peripheral nerve damage in a variety of peripheral neuropathies and may have potential in acting as a surrogate marker for endothelial abnormalities.Keywords: corneal confocal microscopy, cornea, infective keratitis, corneal dystrophy, neuropathy

  11. Digital differential confocal microscopy based on spatial shift transformation.

    Science.gov (United States)

    Liu, J; Wang, Y; Liu, C; Wilson, T; Wang, H; Tan, J

    2014-11-01

    Differential confocal microscopy is a particularly powerful surface profilometry technique in industrial metrology due to its high axial sensitivity and insensitivity to noise. However, the practical implementation of the technique requires the accurate positioning of point detectors in three-dimensions. We describe a simple alternative based on spatial transformation of a through-focus series of images obtained from a homemade beam scanning confocal microscope. This digital differential confocal microscopy approach is described and compared with the traditional Differential confocal microscopy approach. The ease of use of the digital differential confocal microscopy system is illustrated by performing measurements on a 3D standard specimen.

  12. High harmonic terahertz confocal gyrotron with nonuniform electron beam

    Energy Technology Data Exchange (ETDEWEB)

    Fu, Wenjie; Guan, Xiaotong; Yan, Yang [THz Research Center, School of Physical Electronics, University of Electronic Science and Technology of China, Chengdu 610054 (China)

    2016-01-15

    The harmonic confocal gyrotron with nonuniform electron beam is proposed in this paper in order to develop compact and high power terahertz radiation source. A 0.56 THz third harmonic confocal gyrotron with a dual arc section nonuniform electron beam has been designed and investigated. The studies show that confocal cavity has extremely low mode density, and has great advantage to operate at high harmonic. Nonuniform electron beam is an approach to improve output power and interaction efficiency of confocal gyrotron. A dual arc beam magnetron injection gun for designed confocal gyrotron has been developed and presented in this paper.

  13. ConfocalCheck - A Software Tool for the Automated Monitoring of Confocal Microscope Performance

    Science.gov (United States)

    Hng, Keng Imm; Dormann, Dirk

    2013-01-01

    Laser scanning confocal microscopy has become an invaluable tool in biomedical research but regular quality testing is vital to maintain the system’s performance for diagnostic and research purposes. Although many methods have been devised over the years to characterise specific aspects of a confocal microscope like measuring the optical point spread function or the field illumination, only very few analysis tools are available. Our aim was to develop a comprehensive quality assurance framework ranging from image acquisition to automated analysis and documentation. We created standardised test data to assess the performance of the lasers, the objective lenses and other key components required for optimum confocal operation. The ConfocalCheck software presented here analyses the data fully automatically. It creates numerous visual outputs indicating potential issues requiring further investigation. By storing results in a web browser compatible file format the software greatly simplifies record keeping allowing the operator to quickly compare old and new data and to spot developing trends. We demonstrate that the systematic monitoring of confocal performance is essential in a core facility environment and how the quantitative measurements obtained can be used for the detailed characterisation of system components as well as for comparisons across multiple instruments. PMID:24224017

  14. ConfocalCheck--a software tool for the automated monitoring of confocal microscope performance.

    Directory of Open Access Journals (Sweden)

    Keng Imm Hng

    Full Text Available Laser scanning confocal microscopy has become an invaluable tool in biomedical research but regular quality testing is vital to maintain the system's performance for diagnostic and research purposes. Although many methods have been devised over the years to characterise specific aspects of a confocal microscope like measuring the optical point spread function or the field illumination, only very few analysis tools are available. Our aim was to develop a comprehensive quality assurance framework ranging from image acquisition to automated analysis and documentation. We created standardised test data to assess the performance of the lasers, the objective lenses and other key components required for optimum confocal operation. The ConfocalCheck software presented here analyses the data fully automatically. It creates numerous visual outputs indicating potential issues requiring further investigation. By storing results in a web browser compatible file format the software greatly simplifies record keeping allowing the operator to quickly compare old and new data and to spot developing trends. We demonstrate that the systematic monitoring of confocal performance is essential in a core facility environment and how the quantitative measurements obtained can be used for the detailed characterisation of system components as well as for comparisons across multiple instruments.

  15. Development and biological applications of optical tweezers and Raman spectroscopy

    Science.gov (United States)

    Xie, Chang'an

    Optical tweezers is a three-dimensional manipulation tool that employs a gradient force that originates from the single highly focused laser beam. Raman spectroscopy is a molecular analytical tool that can give a highly unique "fingerprint" for each substance by measuring the unique vibrations of its molecules. The combination of these two optical techniques offers a new tool for the manipulation and identification of single biological cells and microscopic particles. In this thesis, we designed and implemented a Laser-Tweezers-Raman-Spectroscopy (LTRS) system, also called the Raman-tweezers, for the simultaneous capture and analysis of both biological particles and non-biological particles. We show that microparticles can be conveniently captured at the focus of a laser beam and the Raman spectra of trapped particles can be acquired with high quality. The LTRS system overcomes the intrinsic Brownian motion and cell motility of microparticles in solution and provides a promising tool for in situ identifying suspicious agents. In order to increase the signal to noise ratio, several schemes were employed in LTRS system to reduce the blank noise and the fluorescence signal coming from analytes and the surrounding background. These techniques include near-infrared excitation, optical levitation, confocal microscopy, and frequency-shifted Raman difference. The LTRS system has been applied for the study in cell biology at the single cell level. With the built Raman-tweezers system, we studied the dynamic physiological processes of single living cells, including cell cycle, the transcription and translation of recombinant protein in transgenic yeast cells and the T cell activation. We also studied cell damage and associated biochemical processes in optical traps, UV radiations, and evaluated heating by near-infrared Raman spectroscopy. These studies show that the Raman-tweezers system is feasible to provide rapid and reliable diagnosis of cellular disorders and can be

  16. Spectra of magnetic fluctuations and relativistic particles produced by a nonresonant wave instability in supernova remnant shocks

    CERN Document Server

    Vladimirov, Andrey E; Ellison, Donald C

    2009-01-01

    We model strong forward shocks in young supernova remnants with efficient particle acceleration where a nonresonant instability driven by the cosmic ray current amplifies magnetic turbulence in the shock precursor. Particle injection, magnetic field amplification (MFA) and the nonlinear feedback of particles and fields on the bulk flow are derived consistently. The shock structure depends critically on the efficiency of turbulence cascading. If cascading is suppressed, MFA is strong, the shock precursor is stratified, and the turbulence spectrum contains several discrete peaks. These peaks, as well as the amount of MFA, should influence synchrotron X-rays, allowing observational tests of cascading and other assumptions intrinsic to the nonlinear model of nonresonant wave growth.

  17. Testing the Validity of the Neoclassical Toroidal Viscosity Model of Torque due to 3D Non-Resonant Magnetic Fields

    Science.gov (United States)

    McCubbin, A. J.; Smith, S. P.; Ferraro, N. M.; Callen, J. D.; Meneghini, O.

    2012-10-01

    Understanding the torque applied by resonant and non-resonant magnetic perturbations and its effect on rotation is essential to predict confinement and stability in burning plasmas. Non-axisymmetric 3D fields produced in the DIII-D tokamak apply a torque to the plasma, which can be evaluated through its effect on the plasma rotation. One explanation for this torque is Neoclassical Toroidal Viscosity (NTV) acting through non-resonant field components [1]. We have developed a software framework in which magnetic perturbations calculated by the state of the art two fluid MHD code M3D-C1 can be used in NTV calculations. For discharges with applied external magnetic fields in DIII-D, the experimentally determined torques will be analyzed and compared with NTV models.[4pt] [1] J.D. Callen, Nucl. Fusion 51, 094026 (2011).

  18. Raman crystallography of RNA.

    Science.gov (United States)

    Gong, Bo; Chen, Jui-Hui; Yajima, Rieko; Chen, Yuanyuan; Chase, Elaine; Chadalavada, Durga M; Golden, Barbara L; Carey, Paul R; Bevilacqua, Philip C

    2009-10-01

    Raman crystallography is the application of Raman spectroscopy to single crystals. This technique has been applied to a variety of protein molecules where it has provided unique information about biopolymer folding, substrate binding, and catalysis. Here, we describe the application of Raman crystallography to functional RNA molecules. RNA represents unique opportunities and challenges for Raman crystallography. One issue that confounds studies of RNA is its tendency to adopt multiple non-functional folds. Raman crystallography has the advantage that it isolates a single state of the RNA within the crystal and can evaluate its fold, metal ion binding properties (ligand identity, stoichiometry, and affinity), proton binding properties (identity, stoichiometry, and affinity), and catalytic potential. In particular, base-specific stretches can be identified and then associated with the binding of metal ions and protons. Because measurements are carried out in the hanging drop at ambient, rather than cryo, conditions and because RNA crystals tend to be approximately 70% solvent, RNA dynamics and conformational changes become experimentally accessible. This review focuses on experimental setup and procedures, acquisition and interpretation of Raman data, and determination of physicochemical properties of the RNA. Raman crystallographic and solution biochemical experiments on the HDV RNA enzyme are summarized and found to be in excellent agreement. Remarkably, characterization of the crystalline state has proven to help rather than hinder functional characterization of functional RNA, most likely because the tendency of RNA to fold heterogeneously is limited in a crystalline environment. Future applications of Raman crystallography to RNA are briefly discussed.

  19. Portable raman explosives detection

    Energy Technology Data Exchange (ETDEWEB)

    Moore, David Steven [Los Alamos National Laboratory; Scharff, Robert J [Los Alamos National Laboratory

    2008-01-01

    Recent advances in portable Raman instruments have dramatically increased their application to emergency response and forensics, as well as homeland defense. This paper reviews the relevant attributes and disadvantages of portable Raman spectroscopy, both essentially and instrumentally, to the task of explosives detection in the field.

  20. Anticipating Non-Resonant New Physics in Dilepton Angular Spectra at the LHC

    CERN Document Server

    Raj, Nirmal

    2016-01-01

    At the LHC, dileptonic events may turn up new physics interacting with quarks and leptons. The poster child for this scenario is a resonant $Z'$, much anticipated in $\\ell^+ \\ell^-$ invariant mass spectra. However, angular spectra of dileptons may play an equal or stronger role in discovering a non-resonant species. This paper avails of their LHC measurements to corner the couplings and masses of leptoquarks (LQs), that can mediate $q \\bar{q} \\rightarrow \\ell^+ \\ell^-$ in the $t$-channel and dramatically alter Standard Model angular spectra. Also derived are constraints from alterations to $m_{\\ell \\ell}$ distributions. These dilepton probes, exploiting the high rates and small uncertainties of the Drell-Yan process, rival or outdo dedicated LHC searches for LQs in single and pair production modes. The couplings of LQs with electronic interactions are best bound today by low-energy measurements of atomic parity violation, but can be probed better by $\\ell^+ \\ell^-$ measurements in the high luminosity runs of ...

  1. Development of nonresonant elliptical vibration cutting device based on parallel piezoelectric actuator

    Science.gov (United States)

    Jieqiong, Lin; Jinguo, Han; Mingming, Lu; Yan, Gu; Wenhui, Zhu

    2017-03-01

    Because of its unique intermittent cutting and friction reversal characteristics, elliptical vibration cutting (EVC) has become the most promising method for machining of otherwise difficult-to-machine materials in recent years. However, some problems remain in the research towards development of EVC devices. In this paper, with the intention of solving the existing problems of EVC devices, a nonresonant-type EVC device that is driven by two parallel piezoelectric stacks is developed. After the principle of the device is introduced, the stiffness of the EVC device is calculated, and device simulations and experimental evaluations are performed. In addition, the performance of the EVC device is also tested. The experimental results show that the maximum strokes of the two directional mechanisms operating along the X- and Z-axes can reach 16.78 μm and 15.35 μm, respectively, and the motion resolutions in the X-axis and Z-axis directions both reach approximately 50 nm. Finally, a curved surface cutting experiment is carried out to verify the performance of the developed device.

  2. Tuning a conventional quantum well laser by nonresonant laser field dressing of the active layer

    Energy Technology Data Exchange (ETDEWEB)

    Radu, Adrian; Eseanu, Nicoleta, E-mail: eseanu@physics.pub.ro; Spandonide, Ana

    2014-10-03

    Highlights: • The feasibility of tuning a GaAs QW laser by ILF dressing was investigated. • The effective mass approximation and finite differences method were used. • Conduction and valence subbands are found to be sensitive to the ILF dressing. • The interband transition energy of the active layer is blueshifted by the ILF. • Emitted wavelength, threshold current and characteristic temperature are discussed. - Abstract: Tunable semiconductor lasers may be considered as a critical technology for optical communications. We investigate the theoretical feasibility of tuning a conventional GaAs/Al{sub 0.2}Ga{sub 0.8}As quantum well laser emitting at 825 nm by non-resonant laser-dressing of the active layer. Conduction and valence subbands are sensitive to the intense dressing field and this effect can be used to blueshift the active interband transition. The laser-dressed electron and hole states are calculated in the effective mass approximation by using the finite difference method. Emitted wavelength, threshold current and characteristic temperature are discussed as functions of the dressing laser parameter and cavity length.

  3. A non-resonant dark-side solution to the solar neutrino problem

    CERN Document Server

    Miranda, O G; Rashba, T I; Semikoz, V B; Valle, José W F

    2001-01-01

    We re-analyse spin-flavour precession solutions to the solar neutrino problem in the light of the recent SNO CC result as well as the 1258-day Super-Kamiokande data and the upper limit on solar anti-neutrinos. In a self-consistent magneto-hydrodynamics approach the resulting scheme has only 3 effective parameters: $\\Delta m^2$, $\\muB_\\perp$ and the neutrino mixing angle $\\theta$. We show how a rates-only analysis slightly favours spin-flavour precession (SFP) solutions over oscillations (OSC). In addition to the resonant solution (RSFP for short), there is a new non-resonant solution (NRSFP) in the ``dark-side''. Both RSFP and NRSFP lead to flat recoil energy spectra in excellent agreement with the latest SuperKamiokande data. We also show that the presence of a magnetic field at the required level of 80 KGauss eliminates all large mixing solutions other than the so-called LMA solution.

  4. The Properties of Lyman Alpha Nebulae: Gas Kinematics from Non-resonant Lines

    CERN Document Server

    Yang, Yujin; Jahnke, Knud; Davé, Romeel

    2014-01-01

    [Abridged] With VLT/X-shooter, we obtain optical and NIR spectra of six Ly-alpha blobs at z~2.3. Using three measures --- the velocity offset between the Lya line and the non-resonant [OIII] or H-alpha line (Dv_Lya), the offset of stacked interstellar metal absorption lines, and the spectrally-resolved [OIII] line profile --- we study the kinematics of gas along the line of sight to galaxies within each blob center. These three indicators generally agree in velocity and direction, and are consistent with a simple picture in which the gas is stationary or slowly outflowing at a few hundred km/s from the embedded galaxies. The absence of stronger outflows is not a projection effect: the covering fraction for our sample is limited to <1/8 (13%). The outflow velocities exclude models in which star formation or AGN produce "super" or "hyper" winds of up to ~1000km/s. The Dv_Lya offsets here are smaller than typical of LBGs, but similar to those of compact LAEs. The latter suggests that outflow speed cannot be a...

  5. Synchronization of three homodromy coupled exciters in a non-resonant vibrating system of plane motion

    Institute of Scientific and Technical Information of China (English)

    Xue-Liang Zhang; Bang-Chun Wen; Chun-Yu Zhao

    2012-01-01

    In this paper,the synchronization problem of three homodromy coupled exciters in a non-resonant vibrating system of plane motion is studied.By introducing the average method of modified small parameters,we deduced dimensionless coupling equation of three exciters,which converted the problem of synchronization into that of the existence and stability of zero solutions for the average differential equations of the small parameters.Based on the dimensionless coupling torques and characteristics of the corresponding limited functions,the synchronization criterion for three exciters was derived as the absolute value of dimensionless residual torque difference between arbitrary two motors being less than the maximum of their dimensionless coupling torques.The stability criterion of its synchronous state lies in the double-condition that the inertia coupling matrix is positive definite and all its elements are positive as well.The synchronization determinants are the coefficients of synchronization ability,also called as the general dynamical symmetry coefficients.The double-equilibrium state of the vibrating system is manifested by numeric method,and the numeric and simulation results derived thereof indicate the indispensable and crucial role the structural parameters of the vibrating system play in the stability criterion of synchronous operation.Besides,by adjusting its structural parameters,the elliptical motion of the vibrating system successfully met the requirements in engineering applications.

  6. Resonant and nonresonant new phenomena of four-fermion operators for experimental searches

    Directory of Open Access Journals (Sweden)

    She-Sheng Xue

    2015-05-01

    Full Text Available In the fermion content and gauge symmetry of the standard model (SM, we study the four-fermion operators in the torsion-free Einstein–Cartan theory. The collider signatures of irrelevant operators are suppressed by the high-energy cutoff (torsion-field mass Λ, and cannot be experimentally accessible at TeV scales. Whereas the dynamics of relevant operators accounts for (i the SM symmetry-breaking in the domain of infrared-stable fixed point with the energy scale v≈239.5 GeV and (ii composite Dirac particles restoring the SM symmetry in the domain of ultraviolet-stable fixed point with the energy scale E≳5 TeV. To search for the resonant phenomena of composite Dirac particles with peculiar kinematic distributions in final states, we discuss possible high-energy processes: multi-jets and dilepton Drell–Yan process in LHC pp collisions, the resonant cross-section in e−e+ collisions annihilating to hadrons and deep inelastic lepton–hadron e−p scatterings. To search for the nonresonant phenomena due to the form-factor of Higgs boson, we calculate the variation of Higgs-boson production and decay rate with the CM energy in LHC. We also present the discussions on four-fermion operators in the lepton sector and the mass-squared differences for neutrino oscillations in short baseline experiments.

  7. Non-resonant magnetic X-ray scattering on NdCu 2

    Science.gov (United States)

    Schneidewind, A.; Loewenhaupt, M.; Hiess, A.; Kramp, S.; Reif, T.; Neubeck, W.; Vettier, C.

    2001-07-01

    The zero-field magnetic phases of NdCu 2 have been investigated using non-resonant X-ray scattering and the results are compared to those from neutron scattering. The reduced scattering volume of X-ray scattering as opposed to the bulk average measured by neutron scattering allowed us to investigate the magnetic properties in the near-surface region. As in the neutron scattering experiment, three magnetic phases AF1, AF2 and AF3 have been observed, and they exist in the same degree of order as the crystal lattice. In the near-surface region, the large magnetic unit cell present in AF2 is slightly different as compared to the bulk. Our results validate the first order of the phase transitions between the magnetic phases and allow us to localize the stabilization of the magnetic phase AF2 in real space. The modulation of the low-temperature structures AF1 and AF2 are squared up. In addition, we find a magnetically induced modulation of the electronic distribution in the low-temperature phase AF1 which is consistent with a lattice distortion (magneto-elastic coupling).

  8. Non-resonant magnetic X-ray scattering on NdCu{sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    Schneidewind, A.; Loewenhaupt, M. E-mail: loewenhaupt@physik.tu-dresden.de; Hiess, A.; Kramp, S.; Reif, T.; Neubeck, W.; Vettier, C

    2001-07-01

    The zero-field magnetic phases of NdCu{sub 2} have been investigated using non-resonant X-ray scattering and the results are compared to those from neutron scattering. The reduced scattering volume of X-ray scattering as opposed to the bulk average measured by neutron scattering allowed us to investigate the magnetic properties in the near-surface region. As in the neutron scattering experiment, three magnetic phases AF1, AF2 and AF3 have been observed, and they exist in the same degree of order as the crystal lattice. In the near-surface region, the large magnetic unit cell present in AF2 is slightly different as compared to the bulk. Our results validate the first order of the phase transitions between the magnetic phases and allow us to localize the stabilization of the magnetic phase AF2 in real space. The modulation of the low-temperature structures AF1 and AF2 are squared up. In addition, we find a magnetically induced modulation of the electronic distribution in the low-temperature phase AF1 which is consistent with a lattice distortion (magneto-elastic coupling)

  9. Anticipating nonresonant new physics in dilepton angular spectra at the LHC

    Science.gov (United States)

    Raj, Nirmal

    2017-01-01

    At the LHC, dileptonic events may turn up new physics interacting with quarks and leptons. The poster child for this scenario is a resonant Z', much anticipated in ℓ+ℓ-invariantmassspectra. However, angular spectra of dileptons may play an equal or stronger role in discovering a nonresonant species. This paper avails their LHC measurements to corner the couplings and masses of leptoquarks (LQs) that can mediate q q ¯→ℓ+ℓ-in the t channel and dramatically alter Standard Model (SM) angular spectra. Also derived are constraints from alterations to mℓℓ distributions. These dilepton probes exploiting the high rates and small uncertainties of the Drell-Yan process, rival or outdo dedicated LHC searches for LQs in single and pair production modes. The couplings of LQs with electronic interactions are best bound today by low-energy measurements of atomic parity violation, but can be probed better by ℓ+ℓ- measurements in the high luminosity runs of the LHC, with the angular spectra leading the way. This work also urges the experimental presentation of boost-invariant angular asymmetries that vanish in the SM.

  10. Biophotonics of skin: method for correction of deep Raman spectra distorted by elastic scattering

    Science.gov (United States)

    Roig, Blandine; Koenig, Anne; Perraut, François; Piot, Olivier; Gobinet, Cyril; Manfait, Michel; Dinten, Jean-Marc

    2015-03-01

    Confocal Raman microspectroscopy allows in-depth molecular and conformational characterization of biological tissues non-invasively. Unfortunately, spectral distortions occur due to elastic scattering. Our objective is to correct the attenuation of in-depth Raman peaks intensity by considering this phenomenon, enabling thus quantitative diagnosis. In this purpose, we developed PDMS phantoms mimicking skin optical properties used as tools for instrument calibration and data processing method validation. An optical system based on a fibers bundle has been previously developed for in vivo skin characterization with Diffuse Reflectance Spectroscopy (DRS). Used on our phantoms, this technique allows checking their optical properties: the targeted ones were retrieved. Raman microspectroscopy was performed using a commercial confocal microscope. Depth profiles were constructed from integrated intensity of some specific PDMS Raman vibrations. Acquired on monolayer phantoms, they display a decline which is increasing with the scattering coefficient. Furthermore, when acquiring Raman spectra on multilayered phantoms, the signal attenuation through each single layer is directly dependent on its own scattering property. Therefore, determining the optical properties of any biological sample, obtained with DRS for example, is crucial to correct properly Raman depth profiles. A model, inspired from S.L. Jacques's expression for Confocal Reflectance Microscopy and modified at some points, is proposed and tested to fit the depth profiles obtained on the phantoms as function of the reduced scattering coefficient. Consequently, once the optical properties of a biological sample are known, the intensity of deep Raman spectra distorted by elastic scattering can be corrected with our reliable model, permitting thus to consider quantitative studies for purposes of characterization or diagnosis.

  11. Confocal laser endomicroscopy in ulcerative colitis

    DEFF Research Database (Denmark)

    Karstensen, John Gásdal; Săftoiu, Adrian; Brynskov, Jørn

    2016-01-01

    was to correlate colonic confocal laser endomicroscopy (CLE) in ulcerative colitis with histopathology and macroscopic appearance before and after intensification of medical treatment. METHODS: Twenty-two patients with ulcerative colitis in clinical relapse and 7 control subjects referred for colonoscopy were...... colitis compared with inactive ulcerative colitis...... is an emerging endoscopic technique that reproducibly identifies mucosal changes in ulcerative colitis. With the exception of crypt changes, endomicroscopic features appear to improve slowly with time after medical treatment. ( CLINICAL TRIAL REGISTRATION NUMBER: NCT01684514.)....

  12. Quantifying metarefraction with confocal lenslet arrays

    CERN Document Server

    Maceina, Tautvydas; Courtial, Johannes

    2011-01-01

    METATOYs can change the direction of light in ways that appear to, but do not actually, contravene the laws of wave optics. This direction change applies only to part of the transmitted light beam; the remainder gets re-directed differently. For a specific example, namely confocal lenslet arrays, we calculate here the fractions of power of an incident uniform plane wave get re-directed in different ways. This will facilitate assessment of the suitability of METATOYs for applications such as solar concentration.

  13. Reflectance confocal microscopy features of facial angiofibromas

    Science.gov (United States)

    Millán-Cayetano, José-Francisco; Yélamos, Oriol; Rossi, Anthony M.; Marchetti, Michael A.; Jain, Manu

    2017-01-01

    Facial angiofibromas are benign tumors presenting as firm, dome-shaped, flesh-colored to pink papules, typically on the nose and adjoining central face. Clinically and dermoscopically they can mimic melanocytic nevi or basal cell carcinomas (BCC). Reflectance confocal microscopy (RCM) is a noninvasive imaging tool that is useful in diagnosing melanocytic and non-melanocytic facial lesions. To date no studies have described the RCM features of facial angiofibromas. Herein, we present two cases of facial angiofibromas that were imaged with RCM and revealed tumor island-like structures that mimicked BCC, leading to skin biopsy.

  14. Coherent anti-Stokes Raman scattering under electric field stimulation

    Science.gov (United States)

    Capitaine, Erwan; Ould Moussa, Nawel; Louot, Christophe; Lefort, Claire; Pagnoux, Dominique; Duclère, Jean-René; Kaneyasu, Junya F.; Kano, Hideaki; Duponchel, Ludovic; Couderc, Vincent; Leproux, Philippe

    2016-12-01

    We introduce an experiment using electro-CARS, an electro-optical method based on the combination of ultrabroadband multiplex coherent anti-Stokes Raman scattering (M-CARS) spectroscopy and electric field stimulation. We demonstrate that this method can effectively discriminate the resonant CARS signal from the nonresonant background owing to a phenomenon of molecular orientation in the sample medium. Such molecular orientation is intrinsically related to the induction of an electric dipole moment by the applied static electric field. Evidence of the electro-CARS effect is obtained with a solution of n -alkanes (CnH2 n +2 , 15 ≤n ≤40 ), for which an enhancement of the CARS signal-to-noise ratio is achieved in the case of CH2 and CH3 symmetric/asymmetric stretching vibrations. Additionally, an electric-field-induced second-harmonic generation experiment is performed in order to corroborate the orientational organization of molecules due to the electric field excitation. Finally, we use a simple mathematical approach to compare the vibrational information extracted from electro-CARS measurements with spontaneous Raman data and to highlight the impact of electric stimulation on the vibrational signal.

  15. Label-free Raman monitoring of extracellular matrix formation in three-dimensional polymeric scaffolds

    Science.gov (United States)

    Kunstar, Aliz; Leferink, Anne M.; Okagbare, Paul I.; Morris, Michael D.; Roessler, Blake J.; Otto, Cees; Karperien, Marcel; van Blitterswijk, Clemens A.; Moroni, Lorenzo; van Apeldoorn, Aart A.

    2013-01-01

    Monitoring extracellular matrix (ECM) components is one of the key methods used to determine tissue quality in three-dimensional scaffolds for regenerative medicine and clinical purposes. Raman spectroscopy can be used for non-invasive sensing of cellular and ECM biochemistry. We have investigated the use of conventional (confocal and semiconfocal) Raman microspectroscopy and fibre-optic Raman spectroscopy for in vitro monitoring of ECM formation in three-dimensional poly(ethylene oxide terephthalate)–poly(butylene terephthalate) (PEOT/PBT) scaffolds. Chondrocyte-seeded PEOT/PBT scaffolds were analysed for ECM formation by Raman microspectroscopy, biochemical analysis, histology and scanning electron microscopy. ECM deposition in these scaffolds was successfully detected by biochemical and histological analysis and by label-free non-destructive Raman microspectroscopy. In the spectra collected by the conventional Raman set-ups, the Raman bands at 937 and at 1062 cm−1 which, respectively, correspond to collagen and sulfated glycosaminoglycans could be used as Raman markers for ECM formation in scaffolds. Collagen synthesis was found to be different in single chondrocyte-seeded scaffolds when compared with microaggregate-seeded samples. Normalized band-area ratios for collagen content of single cell-seeded samples gradually decreased during a 21-day culture period, whereas collagen content of the microaggregate-seeded samples significantly increased during this period. Moreover, a fibre-optic Raman set-up allowed for the collection of Raman spectra from multiple pores inside scaffolds in parallel. These fibre-optic measurements could give a representative average of the ECM Raman signal present in tissue-engineered constructs. Results in this study provide proof-of-principle that Raman microspectroscopy is a promising non-invasive tool to monitor ECM production and remodelling in three-dimensional porous cartilage tissue-engineered constructs. PMID:23825118

  16. Label-free Raman monitoring of extracellular matrix formation in three-dimensional polymeric scaffolds.

    Science.gov (United States)

    Kunstar, Aliz; Leferink, Anne M; Okagbare, Paul I; Morris, Michael D; Roessler, Blake J; Otto, Cees; Karperien, Marcel; van Blitterswijk, Clemens A; Moroni, Lorenzo; van Apeldoorn, Aart A

    2013-09-06

    Monitoring extracellular matrix (ECM) components is one of the key methods used to determine tissue quality in three-dimensional scaffolds for regenerative medicine and clinical purposes. Raman spectroscopy can be used for non-invasive sensing of cellular and ECM biochemistry. We have investigated the use of conventional (confocal and semiconfocal) Raman microspectroscopy and fibre-optic Raman spectroscopy for in vitro monitoring of ECM formation in three-dimensional poly(ethylene oxide terephthalate)-poly(butylene terephthalate) (PEOT/PBT) scaffolds. Chondrocyte-seeded PEOT/PBT scaffolds were analysed for ECM formation by Raman microspectroscopy, biochemical analysis, histology and scanning electron microscopy. ECM deposition in these scaffolds was successfully detected by biochemical and histological analysis and by label-free non-destructive Raman microspectroscopy. In the spectra collected by the conventional Raman set-ups, the Raman bands at 937 and at 1062 cm(-1) which, respectively, correspond to collagen and sulfated glycosaminoglycans could be used as Raman markers for ECM formation in scaffolds. Collagen synthesis was found to be different in single chondrocyte-seeded scaffolds when compared with microaggregate-seeded samples. Normalized band-area ratios for collagen content of single cell-seeded samples gradually decreased during a 21-day culture period, whereas collagen content of the microaggregate-seeded samples significantly increased during this period. Moreover, a fibre-optic Raman set-up allowed for the collection of Raman spectra from multiple pores inside scaffolds in parallel. These fibre-optic measurements could give a representative average of the ECM Raman signal present in tissue-engineered constructs. Results in this study provide proof-of-principle that Raman microspectroscopy is a promising non-invasive tool to monitor ECM production and remodelling in three-dimensional porous cartilage tissue-engineered constructs.

  17. Imaging properties of coherent anti-Stokes Raman scattering microscope

    Institute of Scientific and Technical Information of China (English)

    Yuan Jing-He; Xiao Fan-Rong; Wang Gui-Ying; Xu Zhi-Zhan

    2005-01-01

    The coherent anti-Stokes Raman scattering (CARS) microscope with the combination of confocal and CARS techniques is a remarkable alternative for imaging chemical or biological specimens that neither fluoresce nor tolerate labelling. CARS is a nonlinear optical process, the imaging properties of CARS microscopy will be very different from the conventional confocal microscope. In this paper, the intensity distribution and the polarization property of the optical field near the focus was calculated. By using the Green function, the precise analytic solution to the wave equation of a Hertzian dipole source was obtained. We found that the intensity distributions vary considerably with the different experimental configurations and the different specimen shapes. So the conventional description of microscope (e.g. the point spread function) will fail to describe the imaging properties of the CARS microscope.

  18. Fungal Keratitis - Improving Diagnostics by Confocal Microscopy

    Directory of Open Access Journals (Sweden)

    Esben Nielsen

    2013-12-01

    Full Text Available Purpose: Introducing a simple image grading system to support the interpretation of in vivo confocal microscopy (IVCM images in filamentous fungal keratitis. Setting: Clinical and confocal studies took place at the Department of Ophthalmology, Aarhus University Hospital, Denmark. Histopathological analysis was performed at the Eye Pathology Institute, Department of Neuroscience and Pharmacology, University of Copenhagen, Denmark. Methods: A recent series of consecutive patients with filamentous fungal keratitis is presented to demonstrate the results from in-house IVCM. Based upon our experience with IVCM and previously published images, we composed a grading system for interpreting IVCM images of filamentous fungal keratitis. Results: A recent case series of filamentous fungal keratitis from 2011 to 2012 was examined. There were 3 male and 3 female patients. Mean age was 44.5 years (range 12-69, 6 out of 17 (35% cultures were positive and a total of 6/7 (86% IVCM scans were positive. Three different categories of IVCM results for the grading of diagnostic certainty were formed. Conclusion: IVCM is a valuable tool for diagnosing filamentous fungal keratitis. In order to improve the reliability of IVCM, we suggest implementing a simple and clinically applicable grading system for aiding the interpretation of IVCM images of filamentous fungal keratitis.

  19. Reflectance Confocal Microscopy for Inflammatory Skin Diseases.

    Science.gov (United States)

    Agozzino, M; Gonzalez, S; Ardigò, M

    2016-10-01

    In vivo reflectance confocal microscopy (RCM) is a relatively novel non-invasive tool for microscopic evaluation of the skin used prevalently for diagnosis and management of skin tumour. Its axial resolution, its non-invasive and easy clinical application represents the goals for a large diffusion of this technique. During the last 15 years, RCM has been demonstrated to be able to increase the sensibility and sensitivity of dermoscopy in the diagnosis of skin tumours integrating in real time clinic, dermoscopic and microscopic information useful for the definition of malignancy. Despite to date, no large comparative studies on inflammatory skin diseases has been published in the literature, several papers already showed that RCM has a potential for the evaluation of the descriptive features of the most common inflammatory skin diseases as psoriasis, lupus erythematosus, contact dermatitis and others. The aim of the application of this technique in non-neoplastic skin diseases has been prevalently focused on the possibility of clinical diagnosis confirmation, as well as therapeutic management. Moreover, the use of RCM as driver for an optimised skin biopsy has been also followed in order to reduce the number of unsuccessful histopathological examination. In this review article we describe the confocal features of the major groups of inflammatory skin disorders focusing on psoriasiform dermatitis, interface dermatitis and spongiotic dermatitis.

  20. Raman scattering in crystals

    Energy Technology Data Exchange (ETDEWEB)

    Edwards, D.F.

    1988-09-30

    A tutorial presentation is given of Raman scattering in crystals. The physical concepts are emphasized rather than the detailed mathematical formalism. Starting with an introduction to the concepts of phonons and conservation laws, the effects of photon-phonon interactions are presented. This interaction concept is shown for a simple cubic crystal and is extended to a uniaxial crystal. The correlation table method is used for determining the number and symmetry of the Raman active modes. Finally, examples are given to illustrate the relative ease of using this group theoretical method and the predictions are compared with measured Raman spectra. 37 refs., 17 figs., 6 tabs.

  1. Novel microfluidic devices for Raman spectroscopy and optical trapping

    Science.gov (United States)

    Ottevaere, Heidi; Liu, Qing; de Coster, Diane; Van Erps, Jürgen; Vervaeke, Michael; Thienpont, Hugo

    2016-09-01

    Traditionally, Raman spectroscopy is done in a specialized lab, with considerable requirements in terms of equipment, time and manual sampling of substances of interest. We present the modeling, the design and the fabrication process of a microfluidic device incorporation Raman spectroscopy, from which one enables confocal Raman measurements on-chip. The latter is fabricated using ultra precision diamond tooling and is tested in a proof-of-concept setup, by for example measuring Raman spectra of urea solutions with various concentrations. If one wants to analyze single cells instead of a sample solution, precautions need to be taken. Since Raman scattering is a weak process, the molecular fingerprint of flowing particles would be hard to measure. One method is to stably position the cell under test in the detection area during acquisition of the Raman scattering such that the acquisition time can be increased. Positioning of cells can be done through optical trapping and leads to an enhanced signal-to-noise ratio and thus a more reliable cell identification. Like Raman spectroscopy, optical trapping can also be miniaturized. We present the modeling, design process and fabrication of a mass-manufacturable polymer microfluidic device for dual fiber optical trapping using two counterpropagating singlemode beams. We use a novel fabrication process that consists of a premilling step and ultraprecision diamond tooling for the manufacturing of the molds and double-sided hot embossing for replication, resulting in a robust microfluidic chip for optical trapping. In a proof-of-concept demonstration, we characterize the trapping capabilities of the hot embossed chip.

  2. Re-scan confocal microscopy: scanning twice for better resolution.

    Science.gov (United States)

    De Luca, Giulia M R; Breedijk, Ronald M P; Brandt, Rick A J; Zeelenberg, Christiaan H C; de Jong, Babette E; Timmermans, Wendy; Azar, Leila Nahidi; Hoebe, Ron A; Stallinga, Sjoerd; Manders, Erik M M

    2013-01-01

    We present a new super-resolution technique, Re-scan Confocal Microscopy (RCM), based on standard confocal microscopy extended with an optical (re-scanning) unit that projects the image directly on a CCD-camera. This new microscope has improved lateral resolution and strongly improved sensitivity while maintaining the sectioning capability of a standard confocal microscope. This simple technology is typically useful for biological applications where the combination high-resolution and high-sensitivity is required.

  3. Resonance-Enhanced Raman Spectroscopy on Explosives Vapor at Standoff Distances

    Directory of Open Access Journals (Sweden)

    Anneli Ehlerding

    2012-01-01

    Full Text Available Resonance-enhanced Raman spectroscopy has been used to perform standoff measurements on nitromethane (NM, 2,4-DNT, and 2,4,6-TNT in vapor phase. The Raman cross sections for NM, DNT, and TNT in vapor phase have been measured in the wavelength range 210–300 nm under laboratory conditions, in order to estimate how large resonance enhancement factors can be achieved for these explosives. The results show that the signal is enhanced up to 250,000 times for 2,4-DNT and up to 60,000 times for 2,4,6-TNT compared to the nonresonant signal at 532 nm. Realistic outdoor measurements on NM in vapor phase at 13 m distance were also performed, which indicate a potential for resonance Raman spectroscopy as a standoff technique for detection of vapor phase explosives. In addition, the Raman spectra of acetone, ethanol, and methanol were measured at the same wavelengths, and their influence on the spectrum from NM was investigated.

  4. Random Raman lasing

    CERN Document Server

    Hokr, Brett H; Mason, John D; Beier, Hope T; Rockwll, Benjamin A; Thomas, Robert J; Noojin, Gary D; Petrov, Georgi I; Golovan, Leonid A; Yakovlev, Vladislav V

    2013-01-01

    Propagation of light in a highly scattering medium is among the most fascinating optical effect that everyone experiences on an everyday basis and possesses a number of fundamental problems which have yet to be solved. Conventional wisdom suggests that non-linear effects do not play a significant role because the diffusive nature of scattering acts to spread the intensity, dramatically weakening these effects. We demonstrate the first experimental evidence of lasing on a Raman transition in a bulk three-dimensional random media. From a practical standpoint, Raman transitions allow for spectroscopic analysis of the chemical makeup of the sample. A random Raman laser could serve as a bright Raman source allowing for remote, chemically specific, identification of powders and aerosols. Fundamentally, the first demonstration of this new light source opens up an entire new field of study into non-linear light propagation in turbid media, with the most notable application related to non-invasive biomedical imaging.

  5. Dual Raman-Brillouin Microscope for Chemical and Mechanical Characterization and Imaging.

    Science.gov (United States)

    Traverso, Andrew J; Thompson, Jonathan V; Steelman, Zachary A; Meng, Zhaokai; Scully, Marlan O; Yakovlev, Vladislav V

    2015-08-01

    We present a unique confocal microscope capable of measuring the Raman and Brillouin spectra simultaneously from a single spatial location. Raman and Brillouin scattering offer complementary information about a material's chemical and mechanical structure, respectively, and concurrent monitoring of both of these spectra would set a new standard for material characterization. We achieve this by applying recent innovations in Brillouin spectroscopy that reduce the necessary acquisition times to durations comparable to conventional Raman spectroscopy while attaining a high level of spectral accuracy. To demonstrate the potential of the system, we map the Raman and Brillouin spectra of a molded poly(ethylene glycol) diacrylate (PEGDA) hydrogel sample in cyclohexane to create two-dimensional images with high contrast at microscale resolutions. This powerful tool has the potential for very diverse analytical applications in basic science, industry, and medicine.

  6. Biological applications of confocal fluorescence polarization microscopy

    Science.gov (United States)

    Bigelow, Chad E.

    Fluorescence polarization microscopy is a powerful modality capable of sensing changes in the physical properties and local environment of fluorophores. In this thesis we present new applications for the technique in cancer diagnosis and treatment and explore the limits of the modality in scattering media. We describe modifications to our custom-built confocal fluorescence microscope that enable dual-color imaging, optical fiber-based confocal spectroscopy and fluorescence polarization imaging. Experiments are presented that indicate the performance of the instrument for all three modalities. The limits of confocal fluorescence polarization imaging in scattering media are explored and the microscope parameters necessary for accurate polarization images in this regime are determined. A Monte Carlo routine is developed to model the effect of scattering on images. Included in it are routines to track the polarization state of light using the Mueller-Stokes formalism and a model for fluorescence generation that includes sampling the excitation light polarization ellipse, Brownian motion of excited-state fluorophores in solution, and dipole fluorophore emission. Results from this model are compared to experiments performed on a fluorophore-embedded polymer rod in a turbid medium consisting of polystyrene microspheres in aqueous suspension. We demonstrate the utility of the fluorescence polarization imaging technique for removal of contaminating autofluorescence and for imaging photodynamic therapy drugs in cell monolayers. Images of cells expressing green fluorescent protein are extracted from contaminating fluorescein emission. The distribution of meta-tetrahydroxypheny1chlorin in an EMT6 cell monolayer is also presented. A new technique for imaging enzyme activity is presented that is based on observing changes in the anisotropy of fluorescently-labeled substrates. Proof-of-principle studies are performed in a model system consisting of fluorescently labeled bovine

  7. Fluorescence confocal endomicroscopy in biological imaging

    Science.gov (United States)

    Delaney, Peter; Thomas, Steven; Allen, John; McLaren, Wendy; Murr, Elise; Harris, Martin

    2007-02-01

    In vivo fluorescence microscopic imaging of biological systems in human disease states and animal models is possible with high optical resolution and mega pixel point-scanning performance using optimised off-the-shelf turn-key devices. There are however various trade-offs between tissue access and instrument performance when miniaturising in vivo microscopy systems. A miniature confocal scanning technology that was developed for clinical human endoscopy has been configured into a portable device for direct hand-held interrogation of living tissue in whole animal models (Optiscan FIVE-1 system). Scanning probes of 6.3mm diameter with a distal tip diameter of 5.0mm were constructed either in a 150mm length for accessible tissue, or a 300mm probe for laparoscopic interrogation of internal tissues in larger animal models. Both devices collect fluorescence confocal images (excitation 488 nm; emission >505 or >550 nm) comprised of 1024 x 1204 sampling points/image frame, with lateral resolution 0.7um; axial resolution 7um; FOV 475 x 475um. The operator can dynamically control imaging depth from the tissue surface to approx 250um in 4um steps via an internally integrated zaxis actuator. Further miniaturisation is achieved using an imaging contact probe based on scanning the proximal end of a high-density optical fibre bundle (~30,000 fibres) of sheep and pigs was fluorescently stained with calcein-AM or fluorescein. Surface and sub-surface cellular and sub-cellular details could be readily visualised in vivo at high resolution. In rodent disease models, in vivo endomicroscopy with appropriate fluorescent agents allowed examination of thrombosis formation, tumour microvasculature and liver metastases, diagnosis and staging of ulcerative colitis, liver necrosis and glomerulonephritis. Miniaturised confocal endomicroscopy allows rapid in vivo molecular and subsurface microscopy of normal and pathologic tissue at high resolution in small and large whole animal models

  8. Skin biochemical composition analysis by Raman spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, Patricia Karen; Tosato, Maira Gaspar; Alves, Rani de Souza; Martin, Airton Abrahao; Favero, Priscila Pereira; Raniero, Leandro, E-mail: amartin@univap.br [Laboratorio de Espectroscopia Vibracional Biomedica, Instituto de Pesquisa e Desenvolvimento - IP e D, Universidade do Vale do Paraiba - UniVap, Sao Jose dos Campos, SP (Brazil)

    2012-09-15

    Skin aging is characterized by cellular and molecular alterations. In this context, Confocal Raman spectroscopy was used in vivo to measure these biochemical changes as function of the skin depth. In this study we have tried to correlate spectra from pure amino acids to in vivo spectra from volunteers with different ages. This study was performed on 32 volunteers: 11 from Group A (20-23 years), 11 from Group B (39-42 years) and 10 from Group C (59-62 years). For each group, the Raman spectra were measured on the surface (0 mm), 30 +- 3 mm and 60 +- 3 {mu}m below the surface. The results from intergroup comparisons showed that the oldest group had a prevalence of the tyrosine band, but it also presented a decrease in the band centered at 875 cm{sup -1} of pyrrolidone acid. The amide I band centered at 1637 cm{sup -1} that is attributed to collagen, as well as other proteins and lipid, showed a smaller amount of these biomolecules for Group C, which can be explained by the decrease in collagen concentration as a function of age. (author)

  9. A depth-resolved look at the network development in alkyd coatings by confocal Raman microspectroscopy

    NARCIS (Netherlands)

    Marton, Beáta; Ven, van der Leo G.J.; Otto, Cees; Uzunbajakava, Natalia; Hempenius, Mark A.; Vancso, G. Julius

    2005-01-01

    The formation of molecular networks related to the consumption of unsaturated carbon–carbon double bonds (CC) during oxidative drying of alkyd coating films incorporating unsaturated fatty acids was studied. The concentration of CC bonds was measured as a function of drying time and distance from th

  10. A Depth-Resolved Look at the Network Development in Alkyd Coatings by Confocal Raman Microscopy

    NARCIS (Netherlands)

    Marton, B.; Marton, Beáta; van der Ven, Leo G.J.; Otto, Cornelis; Uzunbajakava, N.; Hempenius, Mark A.; Vancso, Gyula J.

    2005-01-01

    The formation of molecular networks related to the consumption of unsaturated carbon–carbon double bonds (CC) during oxidative drying of alkyd coating films incorporating unsaturated fatty acids was studied. The concentration of CC bonds was measured as a function of drying time and distance from

  11. Near-infrared hyperspectral reflective confocal microscopy

    Science.gov (United States)

    Huang, Wei; Zhang, Yunhai; Miao, Xin; Xue, Xiaojun; Xiao, Yun

    2016-10-01

    A Near-Infrared HyperSpectral Reflective Confocal Microscopy (NIHS-RCM) is proposed in order to get high resolution images of deep biological tissues such as skin. The microscopy system uses a super-continuum laser for illumination, an acousto-optic tunable filter (AOTF) for rapid selection of near-infrared spectrum, a resonant galvanometer scanner for high speed imaging (15f/s) and near-infrared avalanche diode as detector. Porcine skin and other experiments show that the microscopy system could get deep tissue images (180 μm), and show the different ingredients of tissue with different wavelength of illumination. The system has the ability of selectively imaging of multiple ingredients at deep tissue which can be used in skin diseases diagnosis and other fields.

  12. Confocal Terahertz Imaging of Ancient Manuscripts

    Science.gov (United States)

    Flammini, Mariano; Bonsi, Claudia; Ciano, Chiara; Giliberti, Valeria; Pontecorvo, Emanuele; Italia, Paola; DelRe, Eugenio; Ortolani, Michele

    2016-11-01

    Terahertz imaging has the potential to identify and decipher portions of ancient manuscripts, which may be unreadable at infrared and visible wavelengths. We use a scanning confocal terahertz microscope to scan a medieval parchment with music notes and pentagrams written with different inks. The microscope is based on a continuous-wave solid-state source at 0.3 THz, emitting in the free space with a horn antenna, and a high numerical-aperture ellipsoidal reflector. We present terahertz images with diffraction-limited lateral resolution of approximately 0.5 mm, where the different inks all give similar high contrast. Symbols written on the "verso" side of the parchment, barely glimpsed in the near-infrared photograph, leave a clear imprint in the terahertz images. Artifacts due to imperfect flatness of the parchment are also briefly discussed.

  13. Imaging white adipose tissue with confocal microscopy.

    Science.gov (United States)

    Martinez-Santibañez, Gabriel; Cho, Kae Won; Lumeng, Carey N

    2014-01-01

    Adipose tissue is composed of a variety of cell types that include mature adipocytes, endothelial cells, fibroblasts, adipocyte progenitors, and a range of inflammatory leukocytes. These cells work in concert to promote nutrient storage in adipose tissue depots and vary widely based on location. In addition, overnutrition and obesity impart significant changes in the architecture of adipose tissue that are strongly associated with metabolic dysfunction. Recent studies have called attention to the importance of adipose tissue microenvironments in regulating adipocyte function and therefore require techniques that preserve cellular interactions and permit detailed analysis of three-dimensional structures in fat. This chapter summarizes our experience with the use of laser scanning confocal microscopy for imaging adipose tissue in rodents.

  14. Dental caries imaging using hyperspectral stimulated Raman scattering microscopy

    Science.gov (United States)

    Wang, Zi; Zheng, Wei; Jian, Lin; Huang, Zhiwei

    2016-03-01

    We report the development of a polarization-resolved hyperspectral stimulated Raman scattering (SRS) imaging technique based on a picosecond (ps) laser-pumped optical parametric oscillator system for label-free imaging of dental caries. In our imaging system, hyperspectral SRS images (512×512 pixels) in both fingerprint region (800-1800 cm-1) and high-wavenumber region (2800-3600 cm-1) are acquired in minutes by scanning the wavelength of OPO output, which is a thousand times faster than conventional confocal micro Raman imaging. SRS spectra variations from normal enamel to caries obtained from the hyperspectral SRS images show the loss of phosphate and carbonate in the carious region. While polarization-resolved SRS images at 959 cm-1 demonstrate that the caries has higher depolarization ratio. Our results demonstrate that the polarization resolved-hyperspectral SRS imaging technique developed allows for rapid identification of the biochemical and structural changes of dental caries.

  15. Red-detuned, high-intensity, short-duration sweet spot for impulsive X-ray Raman excitation in atoms

    CERN Document Server

    Ware, Matthew R; Haxton, Daniel J

    2016-01-01

    Impulsive X-ray Raman excitations of Lithium, Neon, and Sodium are calculated using the Multiconfiguration Time-Dependent Hartree-Fock method. Using linearly polarized laser pulses without chirp, we determine the optimum central frequency, intensity, and duration for maximum population transfer to valence excited states. We demonstrate the existence of two "sweet spots" for optimum population transfer, either of which, depending on the system, may be superior. The "red-detuned hypothesis" is the proposition that population transfer can be maximized by nonresonant Raman transitions, red-detuned below K-edge, because such detuning minimizes core-excited populations and ionization loss. We find that this hypothesis is verified in the case of Neon -- for Neon, the global optimum for population transfer occurs at high intensity (8 $\\times$ 10$^{19}$ W cm$^{-2}$), short duration (82as full-width-at-half-maximum), and 24eV red-detuned from the K-edge.

  16. Re-scan confocal microscopy: scanning twice for better resolution

    NARCIS (Netherlands)

    De Luca, G.M.R.; Breedijk, R.M.P.; Brandt, R.A.J.; Zeelenberg, C.H.C.; De Jong, B.E.; Timmermans, W.; Nahidi Azar, L.; Hoebe, R.A.; Stallinga, S.; Manders, E.M.M.

    2013-01-01

    We present a new super-resolution technique, Re-scan Confocal Microscopy (RCM), based on standard confocal microscopy extended with an optical (re-scanning) unit that projects the image directly on a CCD-camera. This new microscope has improved lateral resolution and strongly improved sensitivity wh

  17. Re-scan confocal microscopy : scanning twice for better resolution

    NARCIS (Netherlands)

    De Luca, G.M.R.; Breedijk, R.M.P.; Brandt, R.A.J.; Zeelenberg, C.H.C.; de Jong, B.E.; Timmermans, W.; Azar, L.N.; Hoebe, R.A.; Stallinga, S.; Manders, E.M.M.

    2013-01-01

    We present a new super-resolution technique, Re-scan Confocal Microscopy (RCM), based on standard confocal microscopy extended with an optical (re-scanning) unit that projects the image directly on a CCD-camera. This new microscope has improved lateral resolution and strongly improved sensitivity wh

  18. The First Olympus Confocal Micro Imaging Competition China Award Ceremony

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    On January 20, 2010, the award ceremony for the First Olympus Confocal Micro Imaging Competition China was held in Beijing. After rounds of judging and competition, 16 photos finally won the prize.The First Olympus Confocal MicroImaging Competition China Award Ceremony was organized by Sciencenet.cn

  19. In Vivo Confocal Microscopy expanding horizons in corneal imaging

    NARCIS (Netherlands)

    T. Hillenaar (Toine)

    2012-01-01

    textabstractConfocal microscopy is an emerging optical technique that allows the living human cornea to be imaged on a cellular level. As such, confocal microscopy enables morphologic and quantitative analysis of corneal resident cells in health and disease and provides an exciting bridge between in

  20. CONFOCAL LASER SCANNING MICROSCOPY OF RAT FOLLICLE DEVELOPMENT

    Science.gov (United States)

    This study used confocal laser scanning microscopy (CLSM) to study follicular development in millimeter pieces of rat ovary. To use this technology, it is essential to stain the tissue before laser excitation with the confocal microscope. Various fluorescent stains (Yo-Pro, Bo-Pr...

  1. Evaluation and purchase of confocal microscopes: Numerous factors to consider

    Science.gov (United States)

    The purchase of a confocal microscope can be a complex and difficult decision for an individual scientist, group or evaluation committee. This is true even for scientists that have used confocal technology for many years. The task of reaching the optimal decision becomes almost i...

  2. 4D confocal microscopy for visualisation of bone remodelling

    NARCIS (Netherlands)

    Konijn, GA; Vardaxis, NJ; Boon, ME; Kok, LP; Rietveld, DC; SCHUT, JJ

    1996-01-01

    Until recently it was very time consuming and difficult to make three-dimensional (3D) images of newly formed bone. With the advent of confocal technologies and increased computer power 3D imaging is greatly facilitated. In this paper we demonstrate that enhanced confocal visualisation of newly form

  3. In Vivo Confocal Microscopy expanding horizons in corneal imaging

    NARCIS (Netherlands)

    T. Hillenaar (Toine)

    2012-01-01

    textabstractConfocal microscopy is an emerging optical technique that allows the living human cornea to be imaged on a cellular level. As such, confocal microscopy enables morphologic and quantitative analysis of corneal resident cells in health and disease and provides an exciting bridge between in

  4. A first estimate of the NNLO nonresonant corrections to top-antitop threshold production at lepton colliders

    CERN Document Server

    Ruiz-Femenia, Pedro

    2014-01-01

    We compute the dominant term in the expansion in rho=1-M_W/m_t of the unknown next-to-next-to-leading order (NNLO) nonresonant contributions to the e+ e- -> W+ W- b bbar total cross section at energies close to the top-antitop threshold. Our analytic result disagrees with a previous calculation by other authors [1]. We show that our determination has the correct infrared structure needed to cancel the divergences proportional to the top width arising in the resonant production of the same final state, and we point out to a missing contribution in the computation of [1] to explain the discrepancy.

  5. The Properties of Lyα Nebulae: Gas Kinematics from Nonresonant Lines

    Science.gov (United States)

    Yang, Yujin; Zabludoff, Ann; Jahnke, Knud; Davé, Romeel

    2014-10-01

    With the Very Large Telescope/X-shooter, we obtain optical and near-infrared spectra of six Lyα blobs at z ~ 2.3. For a total sample of eight Lyα blobs (including two that we have previously studied), the majority (6/8) have broadened Lyα profiles with shapes ranging from a single peak to symmetric or asymmetric double-peaked. The remaining two systems, in which the Lyα profile is not significantly broader than the [O III] or Hα emission lines, have the most spatially compact Lyα emission, the smallest offset between the Lyα and the [O III] or Hα line velocities, and the only detected C IV and He II lines in the sample, implying that a hard ionizing source, possibly an active galactic nucleus (AGN), is responsible for their lower optical depth. Using three measures—the velocity offset between the Lyα line and the nonresonant [O III] or Hα line (Δv Lyα), the offset of stacked interstellar metal absorption lines, and a new indicator, the spectrally resolved [O III] line profile—we study the kinematics of gas along the line of sight to galaxies within each blob center. These three indicators generally agree in velocity and direction and are consistent with a simple picture in which the gas is stationary or slowly outflowing at a few hundred km s-1 from the embedded galaxies. The absence of stronger outflows is not a projection effect: the covering fraction for our sample is limited to metal absorption line offsets suggest no significant bulk motion, we use a simple radiative transfer model to make the first column density measurement of gas in an embedded galaxy, finding it consistent with a damped Lyα absorption system. Overall, the absence of clear inflow signatures suggests that the channeling of gravitational cooling radiation into Lyα is not significant over the radii probed here. However, one peculiar system (CDFS-LAB10) has a blueshifted Lyα component that is not obviously associated with any galaxy, suggesting either displaced gas arising

  6. Identification of bacteria causing acute otitis media using Raman microspectroscopy

    Science.gov (United States)

    Ayala, Oscar D.; Wakeman, Catherine A.; Skaar, Eric P.; Mahadevan-Jansen, Anita

    2016-03-01

    Otitis media (OM) is the leading cause of acute physician visits and prescription of antibiotics for children. Current standard techniques to diagnose acute otitis media (AOM) are limited by their ability to probe only changes in symptoms of the bacterial infection that cause AOM. Furthermore, they are not able to detect the presence of or identify bacteria causing AOM, which is important for diagnosis and proper antibiotic treatment. Our goal is to detect the presence of and identify the pathogens involved in causing AOM based on their biochemical profile using Raman spectroscopy (RS). An inVia confocal Raman microscope (Renishaw) at 785 nm was used to detect bacteria causing AOM in vitro. The three main bacteria that cause AOM, Haemophilus influenzae, Moraxella catarrhalis, and Streptococcus pneumoniae were cultured in chocolate agar and Mueller-Hinton agar to determine which agar type would minimize Raman signal from the growth agar. Preliminary results identified specific Raman spectral features characteristic of S. pneumoniae. RS has the potential to accurately diagnose AOM, which will help in identifying the antibiotic that will be most beneficial for the patient and ultimately decrease the course of infection.

  7. Raman spectroscopy and immunohistochemistry for schwannoma characterization: a case study

    Science.gov (United States)

    Neto, Lazaro P. M.; das Chagas, Maurilio J.; Carvalho, Luis Felipe C. S.; Ferreira, Isabelle; dos Santos, Laurita; Haddad, Marcelo; Loddi, Vinicius; Martin, Airton A.

    2016-03-01

    The schwannomas is a tumour of the tissue that covers nerves, called the nerve sheath. Schwannomas are often benign tumors of the Schwan cells, which are the principal glia of the peripheral nervous system (PNS). Preoperative diagnosis of this lesion usually is difficult, therefore, new techniques are being studied as pre surgical evaluation. Among these, Raman spectroscopy, that enables the biochemical identification of the tissue analyzed by their optical properties, may be used as a tool for schwannomas diagnosis. The aim of this study was to discriminate between normal nervous tissue and schwannoma through the confocal Raman spectroscopy and Raman optical fiber-based techniques combined with immunohistochemical analysis. Twenty spectra were analyzed from a normal nerve tissue sample (10) and schwannoma (10) by Holospec f / 1.8 (Kayser Optical Systems) coupled to an optical fiber with a 785nm laser line source. The data were pre-processed and vector normalized. The average analysis and standard deviation was performed associated with cluster analysis. AML, 1A4, CD34, Desmin and S-100 protein markers were used for immunohistochemical analysis. Immunohistochemical analysis was positive only for protein S-100 marker which confirmed the neural schwanomma originality. The immunohistochemistry analysis were important to determine the source of the injury, whereas Raman spectroscopy were able to differentiated tissues types indicating important biochemical changes between normal and benign neoplasia.

  8. Raman and surface enhanced Raman spectroscopic investigation on Lamiaceae plants

    Science.gov (United States)

    Rösch, P.; Popp, J.; Kiefer, W.

    1999-05-01

    The essential oils of Thymus vulgaris and Origanum vulgaris are studied by means of micro-Raman spectroscopy. The containing monoterpenes can be identified by their Raman spectra. Further the essential oils are investigated in their natural environment, the so-called oil cells of these Lamiaceae plants, with surface enhanced Raman spectroscopy (SERS). This method has the advantage to enhance Raman signals and furthermore the SERS effect leads to fluorescence quenching.

  9. Solution-based characterization of surface-enhanced Raman response of single scattering centers

    Energy Technology Data Exchange (ETDEWEB)

    Laurence, T A; Talley, C; Schwartzberg, A; Braun, G; Moskovits, M; Reich, N; Huser, T

    2008-03-06

    We demonstrate the rapid optical characterization of large numbers of individual metal nanoparticles freely diffusing in colloidal solution by confocal laser spectroscopy. We find that hollow gold nanospheres and solid silver nanoparticles linked with a bifunctional ligand, both designed nanostructures, exhibit significantly higher monodispersity in their Rayleigh and Raman scattering response than randomly aggregated gold and silver nanoparticles. We show that measurements of rotational diffusion timescales allow sizing of particles significantly more reliably than can be obtained using translational diffusion timescales.

  10. Raman Microscopy and Imaging: Applications to Skin Pharmacology and Wound Healing

    Science.gov (United States)

    Flach, Carol R.; Zhang, Guojin; Mendelsohn, Richard

    The utility of confocal Raman microscopy to study biological events in skin is demonstrated with three examples. (i) monitoring the spatial and structural differences between native and cultured skin, (ii) tracking the permeation and biochemical transformation in skin of a Vitamin E derivative and (iii) tracking the spatial distribution of three major skin proteins (keratin, collagen, and elastin) during wound healing in an explant skin model.

  11. Application of Raman Spectroscopy to the Biooxidation Analysis of Sulfide Minerals

    OpenAIRE

    J. V. García-Meza; R. H. Lara; Navarro-Contreras, H. R.

    2012-01-01

    We report the application of confocal laser scanning microscopy CLSM and Raman spectroscopy on the (bio)chemical oxidation of pyrite and chalcopyrite, in order to understand how surface sulfur species ( S 2 − / S 0 ) affects biofilm evolution during mineral colonization by Acidithiobacillus thiooxidans. We found that cells attachment occurs as cells clusters and monolayered biofilms within the first 12 h. Longer times resulted in the formation of micro- and macrocolonies with variable cell ...

  12. Raman spectroscopy in astrobiology.

    Science.gov (United States)

    Jorge Villar, Susana E; Edwards, Howell G M

    2006-01-01

    Raman spectroscopy is proposed as a valuable analytical technique for planetary exploration because it is sensitive to organic and inorganic compounds and able to unambiguously identify key spectral markers in a mixture of biological and geological components; furthermore, sample manipulation is not required and any size of sample can be studied without chemical or mechanical pretreatment. NASA and ESA are considering the adoption of miniaturised Raman spectrometers for inclusion in suites of analytical instrumentation to be placed on robotic landers on Mars in the near future to search for extinct or extant life signals. In this paper we review the advantages and limitations of Raman spectroscopy for the analysis of complex specimens with relevance to the detection of bio- and geomarkers in extremophilic organisms which are considered to be terrestrial analogues of possible extraterrestial life that could have developed on planetary surfaces.

  13. Raman fiber lasers

    Science.gov (United States)

    Supradeepa, V. R.; Feng, Yan; Nicholson, Jeffrey W.

    2017-02-01

    High-power fiber lasers have seen tremendous development in the last decade, with output powers exceeding multiple kilowatts from a single fiber. Ytterbium has been at the forefront as the primary rare-earth-doped gain medium owing to its inherent material advantages. However, for this reason, the lasers are largely confined to the narrow emission wavelength region of ytterbium. Power scaling at other wavelength regions has lagged significantly, and a large number of applications rely upon the diversity of emission wavelengths. Currently, Raman fiber lasers are the only known wavelength agile, scalable, high-power fiber laser technology that can span the wavelength spectrum. In this review, we address the technology of Raman fiber lasers, specifically focused on the most recent developments. We will also discuss several applications of Raman fiber lasers in laser pumping, frequency conversion, optical communications and biology.

  14. Raman spectrum of asphaltene

    KAUST Repository

    Abdallah, Wael A.

    2012-11-05

    Asphaltenes extracted from seven different crude oils representing different geological formations from around the globe were analyzed using the Raman spectroscopic technique. Each spectrum is fitted with four main peaks using the Gaussian function. On the basis of D1 and G bands of the Raman spectrum, asphaltene indicated an ordered structure with the presence of boundary defected edges. The average aromatic sheet size of the asphaltene molecules is estimated within the range of 1.52-1.88 nm, which represents approximately seven to eight aromatic fused rings. This estimation is based on the integrated intensity of D1 and G bands, as proposed by Tunistra and Koenig. The results here are in perfect agreement with so many other used techniques and indicate the potential applicability of Raman measurements to determine the average aromatic ring size and its boundary. © 2012 American Chemical Society.

  15. Controlling the s-wave scattering length with non-resonant light: Predictions of an asymptotic model

    CERN Document Server

    Crubellier, Anne; Koch, Christiane P; Luc-Koenig, Eliane

    2016-01-01

    A pair of atoms interacts with non-resonant light via its anisotropic polarizability. This effect can be used to tune the scattering properties of the atoms. Although the light-atom interaction varies with interatomic separation as $1/R^{3}$, the effective s-wave potential decreases more rapidly, as $1/R^{4}$ such that the field-dressed scattering length can be determined without any formal difficulty. The scattering dynamics are essentially governed by the long-range part of the interatomic interaction and can thus be accurately described by an asymptotic model [Crubellier et al., New J. Phys. 17, 045020 (2015)]. Here we use the asymptotic model to determine the field-dressed scattering length from the s-wave radial component of a particular threshold wave function. Applying our theory to the scattering of two strontium isotopes, we calculate the variation of the scattering length with the intensity of the non-resonant light. Moreover, we predict the intensities at which the scattering length becomes infinit...

  16. Nonlinear optical properties of free standing films of PbS quantum dots in the nonresonant femtosecond regime

    Science.gov (United States)

    Kurian, Pushpa Ann; Vijayan, C.; Nag, Amit; Goswami, Debabrata

    2013-01-01

    Devices based on optical technology for high speed communication networks require materials with large nonlinear optical response in the ultrafast regime. Nonlinear optical materials have also attracted wide attention as potential candidates for the protection of optical sensors and eyes while handling lasers. Optical limiters have a constant transmittance at low input influence and a decrease in transmittance at higher fluences and are based on a variety of mechanisms such as nonlinear refraction, nonlinear scattering, multiphoton absorption and free carrier absorption. As we go from bulk to nanosized materials especially in the strong quantum confinement regime where radius of the nanoparticle is less than the bulk exciton Bohr radius, the optical nonlinearity is enhanced due to quantum confinement effect. This paper is on the ultrafast nonresonant nonlinearity in free standing films of PbS quantum dots stabilized in a synthetic glue matrix by a simple chemical route which provides flexibility of processing in a variety of physical forms. Optical absorption spectrum shows significant blue shift from the bulk absorption onset indicating strong quantum confinement. PbS quantumdots of mean size 3.3nm are characterized by X-ray diffraction and transmission electron microscopy. The mechanism of nonlinear absorption giving rise to optical limiting is probed using open z-scan technique with laser pulses of 150 fs pulse duration at 780 nm and the results are presented in the nonresonant femtosecond regime. Irradiance dependence on nonlinear absorption are discussed. PMID:24143059

  17. Resonance and non-resonance effect of continuum states of 6Li on elastic scattering angular distributions

    Science.gov (United States)

    Gómez Camacho, A.

    2016-07-01

    CDCC calculations of elastic scattering angular distributions for reactions of the weakly bound projectile 6Li with targets 28Si and 58Ni at energies around the Coulomb barrier are presented. Special emphasis is given to account for the effect of couplings from 6Li resonance states l = 2, J π = 3+, 2+, 1+. Similarly, the effect produced by non-resonant state couplings is studied. The convergent calculations are carried out with global α-target and d-target interactions. The calculated elastic scattering angular distributions are in general in good agreement with the measurements for the systems considered in this work. It is found that the calculations with only resonance states are very similar to that with all couplings (resonance+non-resonance). So, the absence of these states have a strong effect on elastic scattering (non-resonance states calculation). It is shown that the effects increase as the collision energy increases. An interpretation of the strength of the different effects is given in terms of the polarization potentials that emerge from the different couplings.

  18. Nonlinear optical properties of free standing films of PbS quantum dots in the nonresonant femtosecond regime.

    Science.gov (United States)

    Kurian, Pushpa Ann; Vijayan, C; Nag, Amit; Goswami, Debabrata

    2007-09-17

    Devices based on optical technology for high speed communication networks require materials with large nonlinear optical response in the ultrafast regime. Nonlinear optical materials have also attracted wide attention as potential candidates for the protection of optical sensors and eyes while handling lasers. Optical limiters have a constant transmittance at low input influence and a decrease in transmittance at higher fluences and are based on a variety of mechanisms such as nonlinear refraction, nonlinear scattering, multiphoton absorption and free carrier absorption. As we go from bulk to nanosized materials especially in the strong quantum confinement regime where radius of the nanoparticle is less than the bulk exciton Bohr radius, the optical nonlinearity is enhanced due to quantum confinement effect. This paper is on the ultrafast nonresonant nonlinearity in free standing films of PbS quantum dots stabilized in a synthetic glue matrix by a simple chemical route which provides flexibility of processing in a variety of physical forms. Optical absorption spectrum shows significant blue shift from the bulk absorption onset indicating strong quantum confinement. PbS quantumdots of mean size 3.3nm are characterized by X-ray diffraction and transmission electron microscopy. The mechanism of nonlinear absorption giving rise to optical limiting is probed using open z-scan technique with laser pulses of 150 fs pulse duration at 780 nm and the results are presented in the nonresonant femtosecond regime. Irradiance dependence on nonlinear absorption are discussed.

  19. Optimization of confocal scanning laser ophthalmoscope design.

    Science.gov (United States)

    LaRocca, Francesco; Dhalla, Al-Hafeez; Kelly, Michael P; Farsiu, Sina; Izatt, Joseph A

    2013-07-01

    Confocal scanning laser ophthalmoscopy (cSLO) enables high-resolution and high-contrast imaging of the retina by employing spatial filtering for scattered light rejection. However, to obtain optimized image quality, one must design the cSLO around scanner technology limitations and minimize the effects of ocular aberrations and imaging artifacts. We describe a cSLO design methodology resulting in a simple, relatively inexpensive, and compact lens-based cSLO design optimized to balance resolution and throughput for a 20-deg field of view (FOV) with minimal imaging artifacts. We tested the imaging capabilities of our cSLO design with an experimental setup from which we obtained fast and high signal-to-noise ratio (SNR) retinal images. At lower FOVs, we were able to visualize parafoveal cone photoreceptors and nerve fiber bundles even without the use of adaptive optics. Through an experiment comparing our optimized cSLO design to a commercial cSLO system, we show that our design demonstrates a significant improvement in both image quality and resolution.

  20. Electric field effect on the impurity-related electromagnetically induced transparency in a quantum disk under non-resonant, intense laser radiation

    Science.gov (United States)

    Niculescu, E. C.

    2017-04-01

    By considering a three-level ladder-type system under electromagnetically induced transparency, the absorption and dispersion of the probe field in a GaAs disk-like quantum dot under simultaneous action of the electric field and non-resonant, intense laser radiation are investigated. We found that some characteristics such as the width of the transmission window and group velocity can be efficiently manipulated by tuning the control field intensity, non-resonant radiation amplitude and electric field strength. Our results may be relevant for future investigations of the optical process in semiconductor quantum structures and for the technological applications in solid- state optoelectronics.

  1. Confocal supercritical angle fluorescence microscopy for cell membrane imaging

    CERN Document Server

    Sivankutty, Siddharth; Mayet, Céline; Dupuis, Guillaume; Fort, Emmanuel; Lévêque-Fort, Sandrine

    2013-01-01

    We demonstrate sub-wavelength sectioning on biological samples with a conventional confocal microscope. This optical sectioning is achieved by the phenomenon of supercritical angle fuorescence, wherein only a fluorophore next to the interface of a refractive index discontinuity can emit propagating components of radiation into the so-called forbidden angles. The simplicity of this technique allows it to be integrated with a high numerical aperture confocal scanning microscope by only a simple modi?cation on the detection channel. Confocal-SAF microscopy would be a powerful tool to achieve high resolution surface imaging, especially for membrane imaging in biological samples

  2. Calculation of confocal microscope images of cholesteric blue phases

    Science.gov (United States)

    Fukuda, Jun-ichi; Okumura, Yasushi; Kikuchi, Hirotsugu

    2016-03-01

    Real-space images of bulk cholesteric blue phases (BPs) have been successfully obtained by confocal microscopy observations using structural color without doping fluorescent dye. However, theoretical interpretation of these images (for example, the understanding of the relation between intensity distribution and the ordering of BPs) remains challenging because typical lattice spacing of BPs is of the order of the wavelength of visible light, and therefore geometrical optics is entirely useless. In this work, we present a numerical approach to calculate the confocal images of BPs by solving the Maxwell equations. Calculated confocal images are consistent with experimental observations in terms of in-plane symmetry.

  3. Confocal laser endomicroscopy: in vivo endoscopic tissue analysis.

    Science.gov (United States)

    Smith, Christine; Ogilvie, Jeanette; McClelland, Laurie

    2008-01-01

    In today's fast-paced world of instant messaging, high-speed Internet, and cell phones, patients want results of procedures in the same high-speed fashion. The development of the new technique of confocal laser endomicroscopy and the restructuring of the endoscope may enable quick procedure results to be delivered. First used in Germany and Australia for research and now available for clinical use, confocal laser endomicroscopy has been approved by the Food and Drug Administration for marketing and clinical use in the United States. This article provides the gastroenterology nurse with information about how the confocal laser endomicroscope works, assisting with the procedure, and pre- and postprocedure patient instructions.

  4. Confocal Scanner for Vertical Particle Tracks in the Nuclear Photoemulsion

    CERN Document Server

    Soroko, L M

    2005-01-01

    A confocal scanner for selective observation of the vertical particle tracks in the nuclear photoemulsion is described. The particle track being searched for is imaging at an angle of 45$^\\circ$ with respect to the optical axis of the system. The confocal scanner is provided with a new optical element, an "image hogonalizator", by means of which the extended image of the inclined vertical particle track is rotated over an angle of 90$^\\circ$. The stereoscopic version of the confocal scanner is presented as well. The described systems will be used in the experiments for investigation of the neutrino oscillations in the accelerators experiments.

  5. 3D spatially-resolved characterization of chemical environment distributions by inelastic X-ray scattering in confocal setup

    Energy Technology Data Exchange (ETDEWEB)

    Leani, J.J.; Sanchez, H.J.; Perez, R.D. [Universidad Nacional de Cordoba, Cordoba, Cba (Argentina); Perez, C.A. [Laboratoorio Nacional de Luz Sincrotron (LNLS), Campinas, SP (Brazil)

    2012-07-01

    Full text: 3D-micro X-ray fluorescence spectroscopy enables non-destructive three-dimensional investigation of elemental distribution in samples in the micrometer regime. In the last few years, accurate quantification procedures have been developed [1,2]. The most important problem in these quantification procedures is the existence of light elements in the sample from which no fluorescence is detected. This dark matrix problem is not yet solved and is now the most serious limitation of this technique [2]. Resonant Raman scattering is an inelastic scattering process that becomes dominant when atoms are irradiated with incident energy lower and close to an absorption edge. Recently, a spectroscopic technique in formation based in this process showed to be useful to distinguish surrounded chemical environments [3,4]. We present first results regarding the possibility of determining the oxidation state of an element, in a three-dimensional regime, by resonant Raman scattering using an energy dispersive system combined with a confocal setup. A depth scanning of a multilayer sample in confocal setup was carried out in the XRF Beamline of the LNLS (Campinas, Brazil) [5]. The sample consisted of different layers of Cu oxides over a Cu substrate. The sample was irradiated with monochromatic photons having energy close but lower than the K absorption edge of Cu. The Raman peaks were analyzed, residuals were determined and a FFT smoothing procedure, taking into account the instrument functions of the detecting system, was applied. The results show an oscillation pattern that depends on the oxidation state of cooper. The result is relevant since allows the discrimination of the oxidation state of the elements present in a sample in a 3D-micrometer regime by means of resonant Raman scattering combined with a confocal setup. This result could be used as a tool to determine the dark matrix present in the sample with the aim of establishing a reliable quantification procedure. 1

  6. Quantitative assessment of spinal cord injury using circularly polarized coherent anti-Stokes Raman scattering microscopy

    Science.gov (United States)

    Bae, Kideog; Zheng, Wei; Huang, Zhiwei

    2017-08-01

    We report the quantitative assessment of spinal cord injury using the circularly polarized coherent anti-Stokes Raman scattering (CP-CARS) technique together with Stokes parameters in the Poincaré sphere. The pump and Stokes excitation beams are circularly polarized to suppress both the linear polarization-dependent artifacts and the nonresonant background of tissue CARS imaging, enabling quantitative CP-CARS image analysis. This study shows that CP-CARS imaging uncovers significantly increased phase retardance of injured spinal cord tissue as compared to normal tissue, suggesting that CP-CARS is an appealing label-free imaging tool for determining the degree of tissue phase retardance, which could serve as a unique diagnostic parameter associated with nervous tissue injury.

  7. Snapshot Raman Spectral Imager

    Science.gov (United States)

    2010-03-31

    range is appealing in this regard as upper atmospheric absorption by oxygen and ozone eliminate almost all radiation in the Raman shifted range of a...customer wanted to replace a bulky Fourier-Transform Infrared ( FTIR ) system with a dispersive system to lower the cost and size of the instrument. AQT

  8. Microelectrophoresis of Silica Rods Using Confocal Microscopy.

    Science.gov (United States)

    Bakker, Henriëtte E; Besseling, Thijs H; Wijnhoven, Judith E G J; Helfferich, Peter H; van Blaaderen, Alfons; Imhof, Arnout

    2017-01-31

    The electrophoretic mobility and the zeta potential (ζ) of fluorescently labeled colloidal silica rods, with an aspect ratio of 3.8 and 6.1, were determined with microelectrophoresis measurements using confocal microscopy. In the case where the colloidal particles all move at the same speed parallel to the direction of the electric field, we record a xyz-stack over the whole depth of the capillary. This method is faster and more robust compared to taking xyt-series at different depths inside the capillary to obtain the parabolic flow profile, as was done in previous work from our group. In some cases, rodlike particles do not move all at the same speed in the electric field, but exhibit a velocity that depends on the angle between the long axis of the rod and the electric field. We measured the orientation-dependent velocity of individual silica rods during electrophoresis as a function of κa, where κ(-1) is the double layer thickness and a is the radius of the rod associated with the diameter. Thus, we determined the anisotropic electrophoretic mobility of the silica rods with different sized double layers. The size of the double layer was tuned by suspending silica rods in different solvents at different electrolyte concentrations. We compared these results with theoretical predictions. We show that even at already relatively high κa when the Smoluchowski limiting law is assumed to be valid (κa > 10), an orientation dependent velocity was measured. Furthermore, we observed that at decreasing values of κa the anisotropy in the electrophoretic mobility of the rods increases. However, in low polar solvents with κa < 1, this trend was reversed: the anisotropy in the electrophoretic mobility of the rods decreased. We argue that this decrease is due to end effects, which was already predicted theoretically. When end effects are not taken into account, this will lead to strong underestimation of the experimentally determined zeta potential.

  9. Raman Imaging Techniques and Applications

    CERN Document Server

    2012-01-01

    Raman imaging has long been used to probe the chemical nature of a sample, providing information on molecular orientation, symmetry and structure with sub-micron spatial resolution. Recent technical developments have pushed the limits of micro-Raman microscopy, enabling the acquisition of Raman spectra with unprecedented speed, and opening a pathway to fast chemical imaging for many applications from material science and semiconductors to pharmaceutical drug development and cell biology, and even art and forensic science. The promise of tip-enhanced raman spectroscopy (TERS) and near-field techniques is pushing the envelope even further by breaking the limit of diffraction and enabling nano-Raman microscopy.

  10. Detection of neuroinflammation through the retina by means of Raman spectroscopy and multivariate analysis

    Science.gov (United States)

    Marro, Monica; Taubes, Alice; Villoslada, Pablo; Petrov, Dmitri

    2012-06-01

    Retinal nervous tissue sustains a substantial damage during the autoimmune inflammatory processes characteristic for Multiple Sclerosis (MS). The damage can be characterized non-surgically by Raman Spectroscopy, a non-invasive optical imaging technology. We used non-resonant near-infrared Raman spectrosocopy to create a spectral library of eight pivotal biomolecules known to be involved in neuroinflammation: Nicotinamide Adenine Dinucliotide (NADH), Flavin Adenine Nucleotide (FAD), Lactate, Cytochrome C, Glutamate, N-Acetyl- Aspartate (NAA), Phosphotidylcholine, with Advanced Glycolization End Products (AGEs) analyzed as a reference. Principal Component Analysis (PCA) of 50 spectra taken of murine retinal tissue culture undergoing an inflammatory response and healthy controls was used in order to characterize the molecular makeup of the inflammation. The loading plots revealed a heavy influence of peaks related to Glutamate, NADH, and Phosphotidylcholine to inflammation-related spectral changes. Partial Least Squares - Discriminant analysis (PLS-DA) was performed to create a multivariate classifier for the spectral diagnosis of neuroinflammed tissue and yielded a diagnostic sensitivity of 100% and specificity of 100%. We demonstrate then the effectiveness of combining Raman spectroscopy with PCA and PLS-DA statistical techniques to detect and monitor neuroinflamation in retina. With this technique Glutamate, NAA and NADH are detected in retina tissue as signs for neuroinflammation.

  11. Quantum State Absorptions Coupled To Resonance Raman Spectroscopy Could Result In A General Explanation of TERS

    CERN Document Server

    Schultz, Zachary D; Dekhter, Rimma; Anestopoulos, Dimitris; Grammatikopoulos, Spyridon; Papagelis, Kostantinos; Marr, James M; Lewis, David; Galiotis, Costas; Lev, Dimtry; Lewis, Aaron

    2016-01-01

    Tip enhanced Raman scattering (TERS) amplifies the intensity of vibrational Raman scattering by employing the tip of a probe interacting, in ultra close proximity, with a surface. Although a general understanding of the TERS process is still to be fully elucidated, scanning tunneling microscopy (STM) feedback is often applied with success in TERS to keep a noble metal probe in intimate proximity with a noble metal substrate. Since such STM TERS is a common modality, the possible implications of plasmonic fields that may be induced by the tunneling process are investigated and reported. In addition, TERS of a 2D resonant molecular system, a MoS2 bilayer crystal and a 2D non-resonant, lipid molecular bilayer is compared. Data with multiple excitation wavelengths and surfaces for the resonant system in the near- (TERS) and far-field regimes are reported. An interpretation based on weak coupling interactions within the framework of conventional resonance Raman scattering can explain the observed TERS enhancements...

  12. Resonant-Raman Intensities of N-layer Transition Metal Dichalcogenides from First Principles

    Science.gov (United States)

    Miranda, Henrique; Froehlicher, Guillaume; Lorchat, Ettienne; Fernique, François; Molina-Sánchez, Alejandro; Berciaud, Stéphane; Wirtz, Ludger

    Transition metal dichalcogenides (TMDs) have interesting optical and electronic properties that make them good candidates for nano-engineering applications. Raman spectroscopy provides information about the vibrational modes and optical spectrum at the same time: when the laser energy is close to an electronic transition, the intensity is increased due to resonance. We investigate these effects combining different ab initio methods: we obtain ground-state and vibrational properties from density functional theory and the optical absorption spectrum using GW corrections and the Bethe-Salpeter equation to account for the excitonic effects which are known to play an important role in TMDs. Using a quasi-static finite differences approach, we calculate the dielectric susceptibility for different light polarizations and different phonon modes in order to determine the Raman tensor of TMDs, in particular of multi-layer and bulk MoTe2. We explain recent experimental results for the splitting of high-frequency modes and deviations from the non-resonant Raman model. We also give a brief outlook on possible improvements of the methodology.

  13. Automated spherical aberration correction in scanning confocal microscopy

    NARCIS (Netherlands)

    Yoo, H.W.; Royen, M.E.; van Cappellen, W.A.; Houtsmuller, A.B.; Verhaegen, M.H.G.; Schitter, G.

    2014-01-01

    Mismatch between the refractive indexes of immersion media and glass coverslips introduces spherical aberrations in microscopes especially for high numerical aperture objectives. This contribution demonstrates an automated adjustment of the coverslip correction collar in scanning confocal microscopy

  14. THE PARALLEL CONFOCAL DETECTING SYSTEM USING OPTICAL FIBER PLATE

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    Objective Focusing on the problem such as slow scanning speed, complex system design and low light efficiency, a new parallel confocal 3D profile detecting method based on optical fiber technology, which realizes whole-field confocal detecting, is proposed. Methods The optical fiber plate generates an 2D point light source array, which splits one light beam into N2 subbeams and act the role of pinholes as point source and point detecting to filter the stray light and reflect light. By introducing the construction and working principle of the multi-beam 3D detecting system, the feasibility is investigated. Results Experiment result indicates that the optical fiber technology is applicable in rotation. The measuring parameters that influence the detecting can easily be adapted to satisfy different requirments of measurement. Compared with the conventional confocal method, the parallel confocal detecting system using optical fiber plate is simple in the mechanism, the measuring field is larger and the speed is faster.

  15. Interference Confocal Microscope Integrated with Spatial Phase Shifter.

    Science.gov (United States)

    Wang, Weibo; Gu, Kang; You, Xiaoyu; Tan, Jiubin; Liu, Jian

    2016-08-24

    We present an interference confocal microscope (ICM) with a new single-body four-step simultaneous phase-shifter device designed to obtain high immunity to vibration. The proposed ICM combines the respective advantages of simultaneous phase shifting interferometry and bipolar differential confocal microscopy to obtain high axis resolution, large dynamic range, and reduce the sensitivity to vibration and reflectance disturbance seamlessly. A compact single body spatial phase shifter is added to capture four phase-shifted interference signals simultaneously without time delay and construct a stable and space-saving simplified interference confocal microscope system. The test result can be obtained by combining the interference phase response and the bipolar property of differential confocal microscopy without phase unwrapping. Experiments prove that the proposed microscope is capable of providing stable measurements with 1 nm of axial depth resolution for either low- or high-numerical aperture objective lenses.

  16. Law of refraction for generalised confocal lenslet arrays

    CERN Document Server

    Oxburgh, Stephen

    2013-01-01

    We derive the law of generalised refraction for generalised confocal lenslet arrays, which are arrays of misaligned telescopes. We have implemented this law of refraction in TIM, a custom open-source ray tracer.

  17. In vivo confocal microscopy in chloroquine-induced keratopathy

    Directory of Open Access Journals (Sweden)

    Iacopo Paladini

    2013-01-01

    Full Text Available In vivo confocal microscopy is becoming a mandatory examination to study corneal abnormalities such as drug deposits in systemic disease. A female diagnosed with fibromyalgia on systemic chloroquine for 9 months presented for an ophthalmic examination. Confocal microscopy was performed using the Confoscan 4 (Nidek Co. Ltd., Gamagori, Japan and multiple highly reflective deposits in the epithelial basal cells were found, that were consistent with choloquine. Deposits were also present in the wing cell layer. In the anterior stroma these deposits were rare. Atypically shaped and branched nerves were also present in the anterior stroma. Corneal deposits of chloroquine can be evaluated by confocal microscopy. Confocal microscopy provides information on corneal metabolism and physiology. Chloroquine keratopathy can affect the anterior stroma in addition to the epithelium.

  18. Divided-aperture differential confocal fast-imaging microscopy

    Science.gov (United States)

    Wang, Yun; Qiu, Lirong; Zhao, Xiangye; Zhao, Weiqian

    2017-03-01

    A new method, laser divided-aperture differential confocal microscopy (DDCM), is proposed to achieve high-resolution 3D imaging of microstructures of large-scale sample surfaces. This method uses a divided-aperture confocal structure to significantly improve the axial resolution of confocal microscopy and keep a long working distance simultaneously; uses two radically offset point detectors to achieve differential detection to further improve the axial response sensitivity and realize fast imaging of a large-scale sample surface with a big axial scan-step interval. Theoretical analyses and experimental results show that the DDCM can reach an axial resolution of 5 nm with a 3.1 mm working distance with a 3 times imaging speed of a confocal system with the same resolution.

  19. Confocal microscopy description of porosity defects in metallic composite alloys

    Directory of Open Access Journals (Sweden)

    K. Gawdzińska

    2008-03-01

    Full Text Available Possibilit ics of confocal microscopy applications for thc dcscripion of open porosity dcfccts in mctallic composirc alloys arcprcscntcd. This aniclc cbaractcrizcs rhc rncthnd and prcscnts its pssihle applications by describing a rcprcscntnr ivc nrcn of thc cxaminedvoid.

  20. Raman microspectroscopic study of effects of Na(I) and Mg(II) ions on low pH induced DNA structural changes

    NARCIS (Netherlands)

    Muntean, C.M.; Segers-Nolten, G.M.J.

    2003-01-01

    In this work a confocal Raman microspectrometer is used to investigate the influence of Na+ and Mg2+ ions on the DNA structural changes induced by low pH. Measurements are carried out on calf thymus DNA at neutral pH (7) and pH 3 in the presence of low and high concentrations of Na+ and Mg2+ ions, r

  1. Raman spectroscopy an intensity approach

    CERN Document Server

    Guozhen, Wu

    2017-01-01

    This book summarizes the highlights of our work on the bond polarizability approach to the intensity analysis. The topics covered include surface enhanced Raman scattering, Raman excited virtual states and Raman optical activity (ROA). The first chapter briefly introduces the Raman effect in a succinct but clear way. Chapter 2 deals with the normal mode analysis. This is a basic tool for our work. Chapter 3 introduces our proposed algorithm for the Raman intensity analysis. Chapter 4 heavily introduces the physical picture of Raman virtual states. Chapter 5 offers details so that the readers can have a comprehensive idea of Raman virtual states. Chapter 6 demonstrates how this bond polarizability algorithm is extended to ROA intensity analysis. Chapters 7 and 8 offer details on ROA, showing many findings on ROA mechanism that were not known or neglected before. Chapter 9 introduces our proposed classical treatment on ROA which, as combined with the results from the bond polarizability analysis, leads to a com...

  2. A New Multichannel Spectral Imaging Laser Scanning Confocal Microscope

    Directory of Open Access Journals (Sweden)

    Yunhai Zhang

    2013-01-01

    Full Text Available We have developed a new multichannel spectral imaging laser scanning confocal microscope for effective detection of multiple fluorescent labeling in the research of biological tissues. In this paper, the design and key technologies of the system are introduced. Representative results on confocal imaging, 3-dimensional sectioning imaging, and spectral imaging are demonstrated. The results indicated that the system is applicable to multiple fluorescent labeling in biological experiments.

  3. Raman spectroscopy for the assessment of acute myeloid leukemia: a proof of concept study

    Science.gov (United States)

    Vanna, R.; Tresoldi, C.; Ronchi, P.; Lenferink, A. T. M.; Morasso, C.; Mehn, D.; Bedoni, M.; Terstappen, L. W. M. M.; Ciceri, F.; Otto, C.; Gramatica, F.

    2014-03-01

    Acute myeloid leukemia (AML) is a proliferative neoplasm, that if not properly treated can rapidly cause a fatal outcome. The diagnosis of AML is challenging and the first diagnostic step is the count of the percentage of blasts (immature cells) in bone marrow and blood sample, and their morphological characterization. This evaluation is still performed manually with a bright field light microscope. Here we report results of a study applying Raman spectroscopy for analysis of samples from two patients affected by two AML subtypes characterized by a different maturation stage in the neutrophilic lineage. Ten representative cells per sample were selected and analyzed with high-resolution confocal Raman microscopy by scanning 64x64 (4096) points in a confocal layer through the volume of the whole cell. The average spectrum of each cell was then used to obtain a highly reproducible mean fingerprint of the two different AML subtypes. We demonstrate that Raman spectroscopy efficiently distinguishes these different AML subtypes. The molecular interpretation of the substantial differences between the subtypes is related to granulocytic enzymes (e.g. myeloperoxidase and cytochrome b558), in agreement with different stages of maturation of the two considered AML subtypes . These results are promising for the development of a new, objective, automated and label-free Raman based methods for the diagnosis and first assessment of AML.

  4. Evaluation of toroidal torque by non-resonant magnetic perturbations in tokamaks for resonant transport regimes using a Hamiltonian approach

    CERN Document Server

    Albert, Christopher G; Kapper, Gernot; Kasilov, Sergei V; Kernbichler, Winfried; Martitsch, Andreas F

    2016-01-01

    Toroidal torque generated by neoclassical viscosity caused by external non-resonant, non-axisymmetric perturbations has a significant influence on toroidal plasma rotation in tokamaks. In this article, a derivation for the expressions of toroidal torque and radial transport in resonant regimes is provided within quasilinear theory in canonical action-angle variables. The proposed approach treats all low-collisional quasilinear resonant NTV regimes including superbanana plateau and drift-orbit resonances in a unified way and allows for magnetic drift in all regimes. It is valid for perturbations on toroidally symmetric flux surfaces of the unperturbed equilibrium without specific assumptions on geometry or aspect ratio. The resulting expressions are shown to match existing analytical results in the large aspect ratio limit. Numerical results from the newly developed code NEO-RT are compared to calculations by the quasilinear version of the code NEO-2 at low collisionalities. The importance of the magnetic shea...

  5. Onset and Saturation of a Non-resonant Internal Mode in NSTX and Implications For AT Modes in ITER

    Energy Technology Data Exchange (ETDEWEB)

    J.A. Breslau, M.S. Chance, J. Chen, G.Y. Fu, S,. Gerhardt, N. Gorelenkov, S.C. Jardin and J. Manickam

    2011-08-01

    Motivated by experimental observations of apparently triggerless tearing modes, we have performed linear and nonlinear MHD analysis showing that a non-resonant mode with toroidal mode number n = 1 can develop in the National Spherical Torus eXperiment (NSTX) at moderate normalized βN when the shear is low and the central safety factor q0 is close to but greater than one. This mode, which is related to previously identified ‘infernal’ modes, will saturate and persist, and can develop poloidal mode number m = 2 magnetic islands in agreement with experiments. We have also extended this analysis by performing a free-boundary transport simulation of an entire discharge and showing that, with reasonable assumptions, we can predict the time of mode onset. __________________________________________________

  6. Nonresonant third-order nonlinear optical susceptibility of CdS clusters encapsulated in zeolite A and X

    Science.gov (United States)

    Sugimoto, Noriaki; Koiwai, Akihiko; Hyodo, Shi-aki; Hioki, Tatsumi; Noda, Shoji

    1995-02-01

    Nonresonant third-order harmonic generation from CdS clusters encapsulated in zeolite A and X was observed at a fundamental wavelength of 1900 nm. To avoid scattering from the surfaces of the small zeolite crystals, the powder samples were dispersed in a liquid with nearly the same refractive index as that of the samples. The third-order optical susceptibilities of CdS-encapsulated zeolite A and X estimated from the intensity of their Maker fringe patterns were 4.1×10-12 and 1.1×10-11 esu, respectively. These values were slightly smaller than those reported for the 1.5 nm surface-capped CdS cluster. The hyperpolarizabilities of CdS clusters encapsulated in zeolite A and X were estimated by assuming the Lorentz local field to be in the range of 380-480×10-36 and 270-390×10-36 esu, respectively.

  7. Non-resonant Higgs-pair production in the b anti bb anti b final state at the LHC

    Energy Technology Data Exchange (ETDEWEB)

    Wardrope, David; Jansen, Eric; Konstantinidis, Nikos; Cooper, Ben; Falla, Rebecca; Norjoharuddeen, Nurfikri [University College London, Department of Physics and Astronomy, London (United Kingdom)

    2015-05-15

    We present a particle-level study of the Standard Model non-resonant Higgs-pair production process in the b anti bb anti b final state, at the Large Hadron Collider at √(s) = 14 TeV. Each Higgs boson is reconstructed from a pair of close-by jets formed with the anti-k{sub t} jet clustering algorithm, with radius parameter R = 0.4. Given the kinematic properties of the produced Higgs bosons, this Higgs reconstruction approach appears to be more suitable than the use of largeradius jets that was previously proposed in the literature.We find that the sensitivity for observing this final state can be improved significantly when the full set of uncorrelated angular and kinematic variables of the 4b system is exploited, leading to a statistical significance of 1.8 per experiment with an integrated luminosity of 3 ab{sup -1}. (orig.)

  8. Non-resonant instability of coupled Alfvén and drift compressional modes in magnetospheric plasma

    Science.gov (United States)

    Mager, Pavel N.; Klimushkin, Dmitri Yu

    2017-09-01

    A new mechanism of generation of the high-m compressional ULF waves in the magnetosphere is considered. It is suggested that the wave can be generated by the non-resonant instability of coupled Alfvén and drift compressional modes in the energetic component of the magnetospheric plasma. A stability analysis of the of the coupled modes in the inhomogeneous finite-β plasma in the dipole-like field in gyrokinetics is performed. A quadratic equation was obtained that determines mode frequency and the growth rate. The frequencies of both modes depend on the azimuthal wave number, m. The branches are merged at some critical m value, forming a mode with both real and imaginary parts of the wave frequency. This mode is amplified due to the instability called the drift coupling instability. The instability criterion was found. Its growth rate is determined by the mode coupling.

  9. Magnetic field amplification in nonlinear diffusive shock acceleration including resonant and non-resonant cosmic-ray driven instabilities

    CERN Document Server

    Bykov, Andrei M; Osipov, Sergei M; Vladimirov, Andrey E

    2014-01-01

    We present a nonlinear Monte Carlo model of efficient diffusive shock acceleration (DSA) where the magnetic turbulence responsible for particle diffusion is calculated self-consistently from the resonant cosmic-ray (CR) streaming instability, together with non-resonant short- and long-wavelength CR-current-driven instabilities. We include the backpressure from CRs interacting with the strongly amplified magnetic turbulence which decelerates and heats the super-alfvenic flow in the extended shock precursor. Uniquely, in our plane-parallel, steady-state, multi-scale model, the full range of particles, from thermal (~eV) injected at the viscous subshock, to the escape of the highest energy CRs (~PeV) from the shock precursor, are calculated consistently with the shock structure, precursor heating, magnetic field amplification (MFA), and scattering center drift relative to the background plasma. In addition, we show how the cascade of turbulence to shorter wavelengths influences the total shock compression, the d...

  10. Analysis of Amphiphilic Lipids and Hydrophobic Proteins Using Nonresonant Femtosecond Laser Vaporization with Electrospray Post-Ionization

    Science.gov (United States)

    Brady, John J.; Judge, Elizabeth J.; Levis, Robert J.

    2011-04-01

    Amphiphilic lipids and hydrophobic proteins are vaporized at atmospheric pressure using nonresonant 70 femtosecond (fs) laser pulses followed by electrospray post-ionization prior to being transferred into a time-of-flight mass spectrometer for mass analysis. Measurements of molecules on metal and transparent dielectric surfaces indicate that vaporization occurs through a nonthermal mechanism. The molecules analyzed include the lipids 1-monooleoyl-rac-glycerol, 1,2-dihexanoyl- sn-glycero-3-phosphocholine, 1,2-dimyristoyl- sn-glycero-3-phosphocholine, and the hydrophobic proteins gramicidin A, B, and C. Vaporization of lipids from blood and milk are also presented to demonstrate that lipids in complex systems can be transferred intact into the gas phase for mass analysis.

  11. A study on the complexity of a business cycle model with great excitements in non-resonant condition

    Energy Technology Data Exchange (ETDEWEB)

    Ma Junhai [School of Management, Tianjin University, Tianjin 300072 (China); Tianjin University of Finance and Economics, Tianjin 300222 (China)], E-mail: mjhtju@yahoo.com.cn; Cui Yaqiang; Liulixia [School of Management, Tianjin University, Tianjin 300072 (China)

    2009-03-15

    Based on the researches of Szydlowski and Krawiec, we studied the inherent complexity of a chaotic business cycle with great excitements in non-resonant condition. First, we got the first-order and second-order approximate solutions of the system by using multiple scale method. Then deduced the formulation reflecting the complex relations between vibration, phase, bifurcation parameter {mu} and excite frequency {omega} of first-order solution. As the great excitement F varied, the global changes of the system solutions were analyzed. We also explored the different paths leading the systems with different parameter combinations into catastrophe region, fuzzy region or chaos region. Finally, we discussed the evolution trends of business cycle models under the above-mentioned conditions. Hence, this paper has some theoretical and practical significance.

  12. Noninvasive analysis of thin turbid layers using microscale spatially offset Raman spectroscopy.

    Science.gov (United States)

    Conti, Claudia; Realini, Marco; Colombo, Chiara; Sowoidnich, Kay; Afseth, Nils Kristian; Bertasa, Moira; Botteon, Alessandra; Matousek, Pavel

    2015-06-01

    Here, we demonstrate, for the first time, the extension of applicability of recently developed microscale spatially offset Raman spectroscopy (SORS), micro-SORS, from the area of cultural heritage to a wider range of analytical problems involving thin, tens of micrometers thick diffusely scattering turbid layers. The method can be applied in situations where a high turbidity of layers prevents the deployment of conventional confocal Raman microscopy with its depth resolving capability. The method was applied successfully to detect noninvasively the presence of thin, highly turbid layers within polymers, wheat seeds, and paper. An invasive, cross sectional analysis confirmed the micro-SORS findings. Micro-SORS represents a new Raman imaging modality expanding the portfolio of noninvasive, chemically specific analytical tools.

  13. Evaluation of Raman spectra of human brain tumor tissue using the learning vector quantization neural network

    Science.gov (United States)

    Liu, Tuo; Chen, Changshui; Shi, Xingzhe; Liu, Chengyong

    2016-05-01

    The Raman spectra of tissue of 20 brain tumor patients was recorded using a confocal microlaser Raman spectroscope with 785 nm excitation in vitro. A total of 133 spectra were investigated. Spectra peaks from normal white matter tissue and tumor tissue were analyzed. Algorithms, such as principal component analysis, linear discriminant analysis, and the support vector machine, are commonly used to analyze spectral data. However, in this study, we employed the learning vector quantization (LVQ) neural network, which is typically used for pattern recognition. By applying the proposed method, a normal diagnosis accuracy of 85.7% and a glioma diagnosis accuracy of 89.5% were achieved. The LVQ neural network is a recent approach to excavating Raman spectra information. Moreover, it is fast and convenient, does not require the spectra peak counterpart, and achieves a relatively high accuracy. It can be used in brain tumor prognostics and in helping to optimize the cutting margins of gliomas.

  14. Spatio-temporal evolution of the non-resonant instability in shock precursors of young supernova remnants

    Science.gov (United States)

    Kobzar, Oleh; Niemiec, Jacek; Pohl, Martin; Bohdan, Artem

    2017-08-01

    A non-resonant cosmic ray (CR) current-driven instability may operate in the shock precursors of young supernova remnants and be responsible for magnetic-field amplification, plasma heating and turbulence. Earlier simulations demonstrated magnetic-field amplification, and in kinetic studies a reduction of the relative drift between CRs and thermal plasma was observed as backreaction. However, all published simulations used periodic boundary conditions, which do not account for mass conservation in decelerating flows and only allow the temporal development to be studied. Here we report results of fully kinetic particle-in-cell simulations with open boundaries that permit inflow of plasma on one side of the simulation box and outflow at the other end, hence allowing an investigation of both the temporal and the spatial development of the instability. Magnetic-field amplification proceeds as in studies with periodic boundaries and, observed here for the first time, the reduction of relative drifts causes the formation of a shock-like compression structure at which a fraction of the plasma ions are reflected. Turbulent electric field generated by the non-resonant instability inelastically scatters CRs, modifying and anisotropizing their energy distribution. Spatial CR scattering is compatible with Bohm diffusion. Electromagnetic turbulence leads to significant non-adiabatic heating of the background plasma maintaining bulk equipartition between ions and electrons. The highest temperatures are reached at sites of large-amplitude electrostatic fields. Ion spectra show supra-thermal tails resulting from stochastic scattering in the turbulent electric field. Together, these modifications in the plasma flow will affect the properties of the shock and particle acceleration there.

  15. Resonant and non-resonant internal kink modes excited by the energetic electrons on HL-2A tokamak

    Science.gov (United States)

    Yu, L. M.; Chen, W.; Jiang, M.; Shi, Z. B.; Ji, X. Q.; Ding, X. T.; Li, Y. G.; Ma, R. R.; Shi, P. W.; Song, S. D.; Yuan, B. S.; Zhou, Y.; Ma, R.; Song, X. M.; Dong, J. Q.; Xu, M.; Liu, Y.; Yan, L. W.; Yang, Q. W.; Xu, Y. H.; Duan, X. R.; HL-2A Team

    2017-03-01

    Strong resonant and non-resonant internal kink modes (abbreviated as RKs and NRKs, respectively), which are also called resonant and non-resonant fishbones, are observed on HL-2A tokamak with high-power ECRH  +  ECCD‑ (or ECRH) and ECRH  +  ECCD+, respectively. (‘Resonant’ derives from the existence of q  =  1 surface (the resonant surface), and ‘non-resonant’ originates from the absence of q  =  1 surface ({{q}\\text{min}}>1 ). ECCD+ and ECCD‑ mean the driving direction of energetic electrons is the same and opposite to plasma current, respectively.) RK has features of periodic strong bursting amplitude and rapid chirping-down frequency, but NRK usually has the saturated amplitude, slow changed or constant frequency and long-lasting time. The NRK excited by energetic electrons is found for the first time. The reversed q-profiles are formed, and q min decreases during plasma current ramp-up. The value of q min is slightly smaller and a bit bigger than unity for RK and NRK conditions, respectively. The internal kink mode (IKM) structures of RKs and NRKs are confirmed by the ECEI system. Although there are different current drive directions of ECCD for excitation of RK and NRK, they all propagate in electron diamagnetic directions in poloidal. The radial mode structures, frequency and growth rate for IKMs are obtained by solving the dispersion relationship. The NRK is stable when q min is larger than a certain value, and with the decreasing q min the frequency drops, but the growth rate almost keeps constant when {{q}\\text{min}}>1 . This result is in agreement with experimental observation. Studying IKMs excited by energetic electrons can provide important experimental experiences for ITER, because the NRKs may be excited by high-power non-inductive drive of ECCD or ECRH in the operation of hybrid scenarios.

  16. Raman Spectroscopy and Microscopy of Individual Cells andCellular Components

    Energy Technology Data Exchange (ETDEWEB)

    Chan, J; Fore, S; Wachsmann-Hogiu, S; Huser, T

    2008-05-15

    Raman spectroscopy provides the unique opportunity to non-destructively analyze chemical concentrations on the submicron length scale in individual cells without the need for optical labels. This enables the rapid assessment of cellular biochemistry inside living cells, and it allows for their continuous analysis to determine cellular response to external events. Here, we review recent developments in the analysis of single cells, subcellular compartments, and chemical imaging based on Raman spectroscopic techniques. Spontaneous Raman spectroscopy provides for the full spectral assessment of cellular biochemistry, while coherent Raman techniques, such as coherent anti-Stokes Raman scattering is primarily used as an imaging tool comparable to confocal fluorescence microscopy. These techniques are complemented by surface-enhanced Raman spectroscopy, which provides higher sensitivity and local specificity, and also extends the techniques to chemical indicators, i.e. pH sensing. We review the strengths and weaknesses of each technique, demonstrate some of their applications and discuss their potential for future research in cell biology and biomedicine.

  17. Dispersion of nonresonant third-order nonlinearities in GeSiSn ternary alloys

    Science.gov (United States)

    De Leonardis, Francesco; Troia, Benedetto; Soref, Richard A.; Passaro, Vittorio M. N.

    2016-01-01

    Silicon (Si), tin (Sn), and germanium (Ge) alloys have attracted research attention as direct band gap semiconductors with applications in electronics and optoelectronics. In particular, GeSn field effect transistors can exhibit very high performance in terms of power reduction and operating speed because of the high electron drift mobility, while the SiGeSn system can be constructed using CMOS-compatible techniques to realize lasers, LED, and photodetectors. The wide Si, Ge and Sn transparencies allow the use of binary and ternary alloys extended to mid-IR wavelengths, where nonlinearities can also be employed. However, neither theoretical or experimental predictions of nonlinear features in SiGeSn alloys are reported in the literature. For the first time, a rigorous and detailed physical investigation is presented to estimate the two photon absorption (TPA) coefficient and the Kerr refractive index for the SiGeSn alloy up to 12 μm. The TPA spectrum, the effective TPA wavelength cut-off, and the Kerr nonlinear refractive index have been determined as a function of alloy compositions. The promising results achieved can pave the way to the demonstration of on-chip nonlinear-based applications, including mid-IR spectrometer-on-a-chip, all-optical wavelength down/up-conversion, frequency comb generation, quantum-correlated photon-pair source generation and supercontinuum source creation, as well as Raman lasing. PMID:27622979

  18. Dispersion of nonresonant third-order nonlinearities in GeSiSn ternary alloys

    Science.gov (United States)

    de Leonardis, Francesco; Troia, Benedetto; Soref, Richard A.; Passaro, Vittorio M. N.

    2016-09-01

    Silicon (Si), tin (Sn), and germanium (Ge) alloys have attracted research attention as direct band gap semiconductors with applications in electronics and optoelectronics. In particular, GeSn field effect transistors can exhibit very high performance in terms of power reduction and operating speed because of the high electron drift mobility, while the SiGeSn system can be constructed using CMOS-compatible techniques to realize lasers, LED, and photodetectors. The wide Si, Ge and Sn transparencies allow the use of binary and ternary alloys extended to mid-IR wavelengths, where nonlinearities can also be employed. However, neither theoretical or experimental predictions of nonlinear features in SiGeSn alloys are reported in the literature. For the first time, a rigorous and detailed physical investigation is presented to estimate the two photon absorption (TPA) coefficient and the Kerr refractive index for the SiGeSn alloy up to 12 μm. The TPA spectrum, the effective TPA wavelength cut-off, and the Kerr nonlinear refractive index have been determined as a function of alloy compositions. The promising results achieved can pave the way to the demonstration of on-chip nonlinear-based applications, including mid-IR spectrometer-on-a-chip, all-optical wavelength down/up-conversion, frequency comb generation, quantum-correlated photon-pair source generation and supercontinuum source creation, as well as Raman lasing.

  19. Surface enhanced Raman scattering

    CERN Document Server

    Furtak, Thomas

    1982-01-01

    In the course of the development of surface science, advances have been identified with the introduction of new diagnostic probes for analytical characterization of the adsorbates and microscopic structure of surfaces and interfaces. Among the most recently de­ veloped techniques, and one around which a storm of controversy has developed, is what has now been earmarked as surface enhanced Raman scattering (SERS). Within this phenomenon, molecules adsorbed onto metal surfaces under certain conditions exhibit an anomalously large interaction cross section for the Raman effect. This makes it possible to observe the detailed vibrational signature of the adsorbate in the ambient phase with an energy resolution much higher than that which is presently available in electron energy loss spectroscopy and when the surface is in contact with a much larger amount of material than that which can be tolerated in infrared absorption experiments. The ability to perform vibrational spectroscopy under these conditions would l...

  20. HPLC assisted Raman spectroscopic studies on bladder cancer

    Science.gov (United States)

    Zha, W. L.; Cheng, Y.; Yu, W.; Zhang, X. B.; Shen, A. G.; Hu, J. M.

    2015-04-01

    We applied confocal Raman spectroscopy to investigate 12 normal bladder tissues and 30 tumor tissues, and then depicted the spectral differences between the normal and the tumor tissues and the potential canceration mechanism with the aid of the high-performance liquid chromatographic (HPLC) technique. Normal tissues were demonstrated to contain higher tryptophan, cholesterol and lipid content, while bladder tumor tissues were rich in nucleic acids, collagen and carotenoids. In particular, β-carotene, one of the major types of carotenoids, was found through HPLC analysis of the extract of bladder tissues. The statistical software SPSS was applied to classify the spectra of the two types of tissues according to their differences. The sensitivity and specificity of 96.7 and 66.7% were obtained, respectively. In addition, different layers of the bladder wall including mucosa (lumps), muscle and adipose bladder tissue were analyzed by Raman mapping technique in response to previous Raman studies of bladder tissues. All of these will play an important role as a directive tool for the future diagnosis of bladder cancer in vivo.

  1. Measuring Corneal Haze by Using Scheimpflug Photography and Confocal Microscopy

    Science.gov (United States)

    McLaren, Jay W.; Wacker, Katrin; Kane, Katrina M.; Patel, Sanjay V.

    2016-01-01

    Purpose We compared corneal backscatter estimated from a Scheimpflug camera with backscatter estimated from a clinical confocal microscope across a wide range of corneal haze. Methods A total of 59 corneas from 35 patients with a range of severity of Fuchs' endothelial corneal dystrophy and 15 corneas from 9 normal participants were examined using a Scheimpflug camera (Pentacam) and a confocal microscope (ConfoScan 4). The mean image brightness from the anterior 120 μm, midcornea, and posterior 60 μm of the cornea across the central 2 mm recorded by the Scheimpflug camera and analogous regions from the confocal microscope were measured and standardized. Differences between instruments and correlations between backscatter and disease severity were determined by using generalized estimating equation models. Results Backscatter measured by the two instruments in the anterior and midcornea were correlated (r = 0.67 and 0.43, respectively, P < 0.001), although in the posterior cornea they were not correlated (r = 0.13, P = 0.66). Measured with the Scheimpflug camera, mean backscatter from the anterior and midcornea were greater, whereas backscatter from the posterior cornea was lower (P < 0.001) than that measured by the confocal microscope. Backscatter from the anterior cornea was correlated with disease severity for both instruments (Scheimpflug, r = 0.55, P < 0.001; confocal, r = 0.49, P = 0.003). Conclusions The Scheimpflug camera and confocal microscope should not be used interchangeably to measure corneal haze. The ability to detect changes in backscatter with disease severity is superior with the Scheimpflug camera. However, the confocal microscope provides higher resolution of corneal structure. PMID:26803798

  2. Study of corrosion in archaeological gilded irons by Raman imaging and a coupled scanning electron microscope-Raman system

    Science.gov (United States)

    Veneranda, Marco; Costantini, Ilaria; de Vallejuelo, Silvia Fdez-Ortiz; Garcia, Laura; García, Iñaki; Castro, Kepa; Azkarate, Agustín; Madariaga, Juan Manuel

    2016-12-01

    In this work, analytical and chemical imaging tools have been applied to the study of a gilded spur found in the medieval necropolis of Erenozar (Bizkaia, Spain). As a first step, a lot of portable equipment has been used to study the object in a non-invasive way. The hand-held energy-dispersive X-ray fluorescence equipment allowed us to characterize the artefact as a rare example of an iron matrix item decorated by means of a fire gilding technique. On the other hand, the use of a portable Raman system helped us to detect the main degradation compounds affecting the spur. Afterwards, further information was acquired in the laboratory by analysing detached fragments. The molecular images obtained using confocal Raman microscopy permitted us to characterize the stratigraphic succession of iron corrosions. Furthermore, the combined use of this technique with a scanning electron microscope (SEM) was achieved owing to the use of a structural and chemical analyser interface. In this way, the molecular characterization, enhanced by the magnification feature of the SEM, allowed us to identify several micrometric degradation compounds. Finally, the effectiveness of one of the most used desalination baths (NaOH) was evaluated by comparing its effects with those provided by a reference bath (MilliQ). The comparison proved that basic treatment avoided any side effects on the spur decorated by fire gilding, compensating for the lack of bibliographic documentation in this field. This article is part of the themed issue "Raman spectroscopy in art and archaeology".

  3. 3-D laser confocal microscopy study of the oxidation of NdFeB magnets in atmospheric conditions

    Energy Technology Data Exchange (ETDEWEB)

    Meakin, J.P., E-mail: jxm764@bham.ac.uk; Speight, J.D.; Sheridan, R.S.; Bradshaw, A.; Harris, I.R.; Williams, A.J.; Walton, A.

    2016-08-15

    Highlights: • Room temperature atmospheric oxidation behaviour of sintered NdFeB. • 3D laser confocal microscopy measurement of oxide phase growth. • Significant height increase of oxide phase only observed at triple points. • Raman spectroscopy identified oxide phase to be Nd{sub 2}O{sub 3}. • Diffusion coefficient determined to be 4 × 10{sup −13} cm{sup 2}/s. - Abstract: Neodymium iron boron (NdFeB) magnets are used in a number of important applications, such as generators in gearless wind turbines, motors in electric vehicles and electronic goods (e.g.— computer hard disk drives, HDD). Hydrogen can be used as a processing gas to separate and recycle scrap sintered Nd-Fe-B magnets from end-of-life products to form a powder suitable for recycling. However, the magnets are likely to have been exposed to atmospheric conditions prior to processing, and any oxidation could lead to activation problems for the hydrogen decrepitation reaction. Many previous studies on the oxidation of NdFeB magnets have been performed at elevated temperatures; however, few studies have been formed under atmospheric conditions. In this paper a combination of 3-D laser confocal microscopy and Raman spectroscopy have been used to assess the composition, morphology and rate of oxidation/corrosion on scrap sintered NdFeB magnets. Confocal microscopy has been employed to measure the growth of surface reaction products at room temperature, immediately after exposure to air. The results showed that there was a significant height increase at the triple junctions of the Nd-rich grain boundaries. Using Raman spectroscopy, the product was shown to consist of Nd{sub 2}O{sub 3} and formed only on the Nd-rich triple junctions. The diffusion coefficient of the triple junction reaction product growth at 20 °C was determined to be approximately 4 × 10{sup −13} cm{sup 2}/sec. This value is several orders of magnitude larger than values derived from the diffusion controlled oxide growth

  4. Passively mode locked Raman laser

    CERN Document Server

    Liang, W; Savchenkov, A A; Matsko, A B; Seidel, D; Maleki, L

    2010-01-01

    We report on the observation of a novel mode locked optical comb generated at the Raman offset (Raman comb) in an optically pumped crystalline whispering gallery mode resonator. Mode locking is confirmed via measurement of the radio-frequency beat note produced by the optical comb on a fast photodiode. Neither the conventional Kerr comb nor hyper-parametric oscillation is observed when the Raman comb is present.

  5. Raman Scattering of Inorganic Fibers

    OpenAIRE

    1985-01-01

    We have examined evolution of Raman spectra of carbon fibers and SiC fibers through structural transformations caused by heat treatment. Raman spectra of the SiC fibers indicate that the fibers consist of amorphous or microcrystalline SiC and graphitic microcrystals. We discuss the correlation between the tensile strength of the fibers and their microscopic structure deduced from the Raman data.

  6. Biochemical and molecular characterization of thyroid tissue by micro-Raman spectroscopy and gene expression analysis

    Science.gov (United States)

    Neto, Lázaro P. M.; Martin, Aírton A.; Soto, Claudio A. T.; Santos, André B. O.; Mello, Evandro S.; Pereira, Marina A.; Cernea, Cláudio R.; Brandão, Lenine G.; Canevari, Renata A.

    2016-02-01

    Thyroid carcinomas represent the main endocrine malignancy and their diagnosis may produce inconclusive results. Raman spectroscopy and gene expression analysis have shown excellent results on the differentiation of carcinomas. This study aimed to improve the discrimination between different thyroid pathologies combining of both analyses. A total of 35 thyroid tissues samples including normal tissue (n=10), goiter (n=10), papillary (n=10) and follicular carcinomas (n=5) were analyzed. Confocal Raman spectra was obtain by using a Rivers Diagnostic System, 785 nm laser excitation and CCD detector. The data was processed by the software Labspec5 and Origin 8.5 and analyzed by Minitab® program. The gene expression analysis was performed by qRT-PCR technique for TG, TPO, PDGFB, SERPINA1, LGALS3 and TFF3 genes and statistically analyzed by Mann-Whitney test. The confocal Raman spectroscopy allowed a maximum discrimination of 91.1% between normal and tumor tissues, 84.8% between benign and malignant pathologies and 84.6% among carcinomas analyzed. Significant differences was observed for TG, LGALS3, SERPINA1 and TFF3 genes between benign lesions and carcinomas, and SERPINA1 and TFF3 genes between papillary and follicular carcinomas. Principal component analysis was performed using PC1 and PC2 in the papillary carcinoma samples that showed over gene expression when compared with normal sample, where 90% of discrimination was observed at the Amide 1 (1655 cm-1), and at the tyrosine spectra region (856 cm-1). The discrimination of tissues thyroid carried out by confocal Raman spectroscopy and gene expression analysis indicate that these techniques are promising tools to be used in the diagnosis of thyroid lesions.

  7. Fused oblique incidence reflectometry and confocal fluorescence microscopy

    Science.gov (United States)

    Risi, Matthew D.; Rouse, Andrew R.; Gmitro, Arthur F.

    2011-03-01

    Confocal microendoscopy provides real-time high resolution cellular level images via a minimally invasive procedure, but relies on exogenous fluorophores, has a relatively limited penetration depth (100 μm) and field of view (700 μm), and produces a high rate of detailed information to the user. A new catheter based multi-modal system has been designed that combines confocal imaging and oblique incidence reflectometry (OIR), which is a non-invasive method capable of rapidly extracting tissue absorption, μa, and reduced scattering, μ's, spectra from tissue. The system builds on previous developments of a custom slit-scan multi-spectral confocal microendoscope and is designed to rapidly switch between diffuse spectroscopy and confocal fluorescence imaging modes of operation. An experimental proof-of-principle catheter has been developed that consists of a fiber bundle for traditional confocal fluorescence imaging and a single OIR source fiber which is manually redirected at +/- 26 degrees. Diffusely scattered light from each orientation of the source fiber is collected via the fiber bundle, with a frame of data representing spectra collected at a range of distances from the OIR source point. Initial results with intralipid phantoms show good agreement to published data over the 550-650 nm spectral range. We successfully imaged and measured the optical properties of rodent cardiac muscle.

  8. Real-Time Confocal Imaging Of The Living Eye

    Science.gov (United States)

    Jester, James V.; Cavanagh, H. Dwight; Essepian, John; Shields, William J.; Lemp, Michael A.

    1989-12-01

    In 1986, we adapted the Tandem Scanning Reflected Light Microscope of Petran and Hadraysky to permit non-invasive, confocal imaging of the living eye in real-time. We were first to obtain stable, confocal optical sections in vivo, from human and animal eyes. Using confocal imaging systems we have now studied living, normal volunteers, rabbits, cats and primates sequentially, non-invasively, and in real-time. The continued development of real-time confocal imaging systems will unlock the door to a new field of cell biology involving for the first time the study of dynamic cellular processes in living organ systems. Towards this end we have concentrated our initial studies on three areas (1) evaluation of confocal microscope systems for real-time image acquisition, (2) studies of the living normal cornea (epithelium, stroma, endothelium) in human and other species; and (3) sequential wound-healing responses in the cornea in single animals to lamellar-keratectomy injury (cellular migration, inflammation, scarring). We believe that this instrument represents an important, new paradigm for research in cell biology and pathology and that it will fundamentally alter all experimental and clinical approaches in future years.

  9. Confocal and Two-Photon Microscopy: Foundations, Applications and Advances

    Science.gov (United States)

    Diaspro, Alberto

    2001-11-01

    Confocal and Two-Photon Microscopy Foundations, Applications, and Advances Edited by Alberto Diaspro Confocal and two-photon fluorescence microscopy has provided researchers with unique possibilities of three-dimensional imaging of biological cells and tissues and of other structures such as semiconductor integrated circuits. Confocal and Two-Photon Microscopy: Foundations, Applications, and Advances provides clear, comprehensive coverage of basic foundations, modern applications, and groundbreaking new research developments made in this important area of microscopy. Opening with a foreword by G. J. Brakenhoff, this reference gathers the work of an international group of renowned experts in chapters that are logically divided into balanced sections covering theory, techniques, applications, and advances, featuring: In-depth discussion of applications for biology, medicine, physics, engineering, and chemistry, including industrial applications Guidance on new and emerging imaging technology, developmental trends, and fluorescent molecules Uniform organization and review-style presentation of chapters, with an introduction, historical overview, methodology, practical tips, applications, future directions, chapter summary, and bibliographical references Companion FTP site with full-color photographs The significant experience of pioneers, leaders, and emerging scientists in the field of confocal and two-photon excitation microscopy Confocal and Two-Photon Microscopy: Foundations, Applications, and Advances is invaluable to researchers in the biological sciences, tissue and cellular engineering, biophysics, bioengineering, physics of matter, and medicine, who use these techniques or are involved in developing new commercial instruments.

  10. Practical Raman spectroscopy an introduction

    CERN Document Server

    Vandenabeele, Peter

    2013-01-01

    This text offers an open-learning approach to Raman spectroscopy providing detail on instrumentation, applications and discussions questions throughout the book. It provides a valuable guide to assist with teaching Raman spectroscopy which is gaining attention in (analytical) chemistry, and as a consequence, teaching programs have followed. Today, education in Raman spectroscopy is often limited to theoretical aspects (e.g. selection rules), but practical aspects are usually disregarded. With these course notes, the author hopes to fill this gap and include information about Raman instrumentat

  11. Confocal microscopy for visualization and characterization of porous silicon samples

    Science.gov (United States)

    Doia, Petronela; Petris, A.; Dancus, I.; Vlad, V. I.

    2007-08-01

    We have developed a scanning confocal microscopy (SCM) system which can be used to investigate micro-structural properties of samples with micro-geometry. We present advantages of this imaging technique for visualization and characterization of some periodic and non-periodic (porous silicon with an alveolar columnar structure (1.5 - 3 μm pores diameters)) samples. Using the confocal microscopy, we can obtain an enhancement of image resolution and contrast, in comparison with conventional optical microscopy. Therefore, it has particular advantages for the study of porous silicon. Confocal imaging method permit the "optical sectioning" of samples and lead to a sub-micron resolution both in lateral plane and axial plane.

  12. Image Restoration Phase-Filtering Lateral Superresolution Confocal Microscopy

    Institute of Scientific and Technical Information of China (English)

    ZHAO Wei-Qian; QIU Li-Rong; CHEN Shan-Shan; FENG Zheng-De

    2006-01-01

    @@ Image restoration phase-filtering lateral superresolution confocal microscopy, a new approach, is proposed to achieve lateral superresolution using a confocal microscope. This approach uses a lateral superresolution pupil filter to preliminarily improve its lateral resolution and uses a single-image superresolution restoration technique based on a maximum likelihood estimate to further improve its lateral resolution. The new approach has the advantages of a low cost and the remarkable superresolution effect without excessive system complexity. Experiments indicate that the proposed approach can improve the lateral resolution of a confocal microscope from 0.3μm to less than 0.1 μm when λ = 632.8 nm and NA =0.85.

  13. Simple high-speed confocal line-scanning microscope.

    Science.gov (United States)

    Im, Kang-Bin; Han, Sumin; Park, Hwajoon; Kim, Dongsun; Kim, Beop-Min

    2005-06-27

    Using a line scan camera and an acousto-optic deflector (AOD), we constructed a high-speed confocal laser line-scanning microscope that can generate confocal images (512 x 512 pixels) with up to 191 frames/s without any mechanically moving parts. The line scanner consists of an AOD and a cylindrical lens, which creates a line focus sweeping over the sample. The measured resolutions in z (depth), x (perpendicular to line focus), and y (direction of line focus) directions are 3.3 mum, 0.7 mum and 0.9 mum, respectively, with a 50x objective lens. This confocal microscope may be useful for analyzing fast phenomena during biological and chemical interactions and for fast 3D image reconstruction.

  14. Second-harmonic patterned polarization-analyzed reflection confocal microscope

    Science.gov (United States)

    Okoro, Chukwuemeka; Toussaint, Kimani C.

    2017-08-01

    We introduce the second-harmonic patterned polarization-analyzed reflection confocal (SPPARC) microscope-a multimodal imaging platform that integrates Mueller matrix polarimetry with reflection confocal and second-harmonic generation (SHG) microscopy. SPPARC microscopy provides label-free three-dimensional (3-D), SHG-patterned confocal images that lend themselves to spatially dependent, linear polarimetric analysis for extraction of rich polarization information based on the Mueller calculus. To demonstrate its capabilities, we use SPPARC microscopy to analyze both porcine tendon and ligament samples and find differences in both circular degree-of-polarization and depolarization parameters. Moreover, using the collagen-generated SHG signal as an endogenous counterstain, we show that the technique can be used to provide 3-D polarimetric information of the surrounding extrafibrillar matrix plus cells or EFMC region. The unique characteristics of SPPARC microscopy holds strong potential for it to more accurately and quantitatively describe microstructural changes in collagen-rich samples in three spatial dimensions.

  15. A Simple Model for Nonlinear Confocal Ultrasonic Beams

    Institute of Scientific and Technical Information of China (English)

    ZHANG Dong; ZHOU Lin; SI Li-Sheng; GONG Xiu-Fen

    2007-01-01

    @@ A confocally and coaxially arranged pair of focused transmitter and receiver represents one of the best geometries for medical ultrasonic imaging and non-invasive detection. We develop a simple theoretical model for describing the nonlinear propagation of a confocal ultrasonic beam in biological tissues. On the basis of the parabolic approximation and quasi-linear approximation, the nonlinear Khokhlov-Zabolotskaya-Kuznetsov (KZK) equation is solved by using the angular spectrum approach. Gaussian superposition technique is applied to simplify the solution, and an analytical solution for the second harmonics in the confocal ultrasonic beam is presented.Measurements are performed to examine the validity of the theoretical model. This model provides a preliminary model for acoustic nonlinear microscopy.

  16. On the use of Raman spectroscopy and instrumented indentation for characterizing damage in machined carbide ceramics

    Science.gov (United States)

    Groth, Benjamin Peter

    Machining is a necessary post-processing step in the manufacturing of many ceramic materials. Parts are machined to meet specific dimensions, with tight tolerances, not attainable from forming alone, as well as to achieve a desired surface finish. However, the machining process is very harsh, often employing the use of high temperatures and pressures to achieve the wanted result. In the case of silicon carbide, a material with extremely high hardness and stiffness, machining is very difficult and requires machining conditions that are highly aggressive. This can leave behind residual stresses in the surface of the material, cause unwanted phase transformations, and produce sub-surface deformation that can lead to failure. This thesis seeks to determine the effect of various machining conditions on the Raman spectra and elastic properties of sintered silicon carbide materials. Sample sets examined included hot-pressed silicon carbide tiles with four different surface finishes, as well as "ideal" single crystal silicon carbide wafers. The surface finishes studied were as follows: an as-pressed finish; a grit blast finish; a harsh rotary ground finish; and a mirror polish. Each finish imparts a different amount, as well as type, of deformation to the sample and are each utilized for a specific application. The sample surfaces were evaluated using a combination of Raman spectroscopy, for phase identification and stress analysis, and nanoindentation, for obtaining elastic properties and imparting uniform controlled deformation to the samples. Raman spectroscopy was performed over each sample surface using 514- and 633-nm wavelength excitation, along with confocal and non-confocal settings to study depth variation. Surfaces stresses were determined using peak shift information extracted from Raman spectra maps, while other spectral variations were used to compare levels of machining damage. Elastic modulus, hardness, and plastic work of indentation maps were generated

  17. Ex vivo laser confocal microscopy findings of cultured Acanthamoeba trophozoites

    Directory of Open Access Journals (Sweden)

    Yamazaki N

    2012-08-01

    Full Text Available Natsuko Yamazaki,1 Akira Kobayashi,1 Hideaki Yokogawa,1 Yasuhisa Ishibashi,2 Yosaburo Oikawa,3 Masaharu Tokoro,4 Kazuhisa Sugiyama11Department of Ophthalmology, Kanazawa University Graduate School of Medical Science, Kanazawa, Japan; 2Department of Ophthalmology, East Washinomiya Hospital, Kuki, Japan; 3Department of Medical Zoology, Kanazawa Medical University, Kahoku, Japan; 4Department of Parasitology, Kanazawa University Graduate School of Medical Science, Kanazawa, JapanPurpose: The purpose of the current study was to investigate ex vivo laser confocal microscopic findings of cultured Acanthamoeba trophozoites obtained from Acanthamoeba keratitis patients.Methods: Eight cultured samples of Acanthamoeba trophozoites from eight eyes of seven patients (mean age, 26.9 years; age range, 18–52 years were used. Seven samples were from corneal scrapings of Acanthamoeba keratitis patients and one sample was from the solution in a soft contact lens case. Ex vivo laser confocal microscopy was performed to qualitatively evaluate the shape and degree of light reflection of the living Acanthamoeba trophozoites.Results: Ex vivo laser confocal microscopy demonstrated highly reflective, high-contrast Acanthamoeba trophozoites with no walls (mean size, 25.4 µm; range, 17.1–58.5 µm. The shapes of the trophozoites were highly pleomorphic, and some showed characteristic acanthopodia by laser confocal microscopy.Conclusion: Ex vivo laser confocal microscopy was effective in demonstrating cultured Acanthamoeba trophozoites of various shapes and sizes. The observations of the current study may be helpful when similar structures are identified under in vivo conditions.Keywords: Acanthamoeba, trophozoite, laser confocal microscopy

  18. Microscopia confocal in vivo na cistinose: relato de caso

    Directory of Open Access Journals (Sweden)

    Victor Gustavo

    2004-01-01

    Full Text Available A cistinose é doença autossômica recessiva rara caracterizada pelo acúmulo do aminoácido cistina livre dentro dos lisossomos e geralmente é fatal na primeira década de vida na ausência de transplante renal. O presente estudo tem por objetivo relatar os achados da microscopia confocal in vivo em paciente adulto com cistinose infantil. O exame de microscopia confocal in vivo revelou que há diferenças quanto à intensidade de acometimento, tamanho e forma dos depósitos nas diversas camadas corneanas.

  19. A Pico Projector Source for Confocal Fluorescence and Ophthalmic Imaging.

    Science.gov (United States)

    Muller, Matthew S

    2012-09-02

    A Pico digital light projector has been implemented as an integrated illumination source and spatial light modulator for confocal imaging. The target is illuminated with a series of rapidly projected lines or points to simulate scanning. Light returning from the target is imaged onto a 2D rolling shutter CMOS sensor. By controlling the spatio-temporal relationship between the rolling shutter and illumination pattern, light returning from the target is spatially filtered. Confocal retinal, fluorescence, and Fourier-domain optical coherence tomography implementations of this novel imaging technique are presented.

  20. Confocal shift interferometry of coherent emission from trapped dipolar excitons

    Energy Technology Data Exchange (ETDEWEB)

    Repp, J. [Walter Schottky Institut and Physik-Department, Am Coulombwall 4a, Technische Universität München, D-85748 Garching (Germany); Nanosystems Initiative Munich (NIM), Schellingstr. 4, 80799 München (Germany); Center for NanoScience and Fakultät für Physik, Ludwig-Maximilians-Universität, Geschwister-Scholl-Platz 1, 80539 München (Germany); Schinner, G. J.; Schubert, E. [Nanosystems Initiative Munich (NIM), Schellingstr. 4, 80799 München (Germany); Center for NanoScience and Fakultät für Physik, Ludwig-Maximilians-Universität, Geschwister-Scholl-Platz 1, 80539 München (Germany); Rai, A. K.; Wieck, A. D. [Angewandte Festkörperphysik, Ruhr-Universität Bochum, Universitätsstraße 150, 44780 Bochum (Germany); Reuter, D. [Angewandte Festkörperphysik, Ruhr-Universität Bochum, Universitätsstraße 150, 44780 Bochum (Germany); Department Physik, Universität Paderborn, 33098 Paderborn (Germany); Wurstbauer, U.; Holleitner, A. W. [Walter Schottky Institut and Physik-Department, Am Coulombwall 4a, Technische Universität München, D-85748 Garching (Germany); Nanosystems Initiative Munich (NIM), Schellingstr. 4, 80799 München (Germany); and others

    2014-12-15

    We introduce a confocal shift-interferometer based on optical fibers. The presented spectroscopy allows measuring coherence maps of luminescent samples with a high spatial resolution even at cryogenic temperatures. We apply the spectroscopy onto electrostatically trapped, dipolar excitons in a semiconductor double quantum well. We find that the measured spatial coherence length of the excitonic emission coincides with the point spread function of the confocal setup. The results are consistent with a temporal coherence of the excitonic emission down to temperatures of 250 mK.

  1. EUS-Guided Needle-Based Confocal Laser Endomicroscopy

    DEFF Research Database (Denmark)

    Bhutani, Manoop S; Koduru, Pramoda; Joshi, Virendra;

    2015-01-01

    the gut, providing further diagnostic and staging information. Confocal laser endomicroscopy (CLE) is a novel endoscopic method that enables imaging at a subcellular level of resolution during endoscopy, allowing up to 1000-fold magnification of tissue and providing an optical biopsy. A new procedure...... that has been developed in the past few years is needle-based confocal laser endomicroscopy (nCLE), which involves a mini-CLE probe that can be passed through a 1 9-gauge needle during EUS-FNA. This enables the real-time visualization of tissue at a microscopic level, with the potential to further improve...

  2. Integration of a nanostructured dielectrophoretic device and a surface-enhanced Raman probe for highly sensitive rapid bacteria detection.

    Science.gov (United States)

    Madiyar, Foram Ranjeet; Bhana, Saheel; Swisher, Luxi Z; Culbertson, Christopher T; Huang, Xiaohua; Li, Jun

    2015-02-28

    This work reports a synergistic approach to the concentration, detection and kinetic monitoring of pathogens through the integration of nanostructured dielectrophoresis (DEP) with nanotag-labelled Surface Enhanced Raman Spectroscopy (SERS). A nanoelectrode array made of embedded Vertically Aligned Carbon Nanofibers (VACNFs) at the bottom of a microfluidic chip was used to effectively capture and concentrate nanotag-labelled E. coli DHα5 cells into a 200 μm × 200 μm area on which a Raman laser probe was focused. The SERS nanotags were based on iron oxide-gold (IO-Au) core-shell nanoovals (NOVs) of ∼50 nm size, which were coated with a QSY21 Raman reporter and attached to E. coli through specific immunochemistry. The combination of the greatly enhanced Raman signal by the SERS nanotags and the effective DEP concentration significantly improved the detection limit and speed. The SERS signal was measured with both a confocal Raman microscope and a portable Raman probe during DEP capture, and was fully validated with fluorescence microscopy measurements under all DEP conditions. The SERS measurements were sensitive enough to detect a single bacterium. A concentration detection limit as low as 210 cfu ml(-1) using a portable Raman system was obtained with a DEP capture time of only ∼50 s. These results demonstrate the potential to develop a compact portable system for rapid and highly sensitive detection of specific pathogens. This system is reusable, requires minimum sample preparation, and is amenable to field applications.

  3. Fluorescence and Raman spectra on surface of K9 glass by high fluence ultraviolet laser irradiation at 355 nm

    Science.gov (United States)

    Zhang, Zhen; Huang, Jin; Geng, Feng; Zhou, Xiaoyan; Feng, Shiquan; Ren, Dahua; Cheng, Xinlu; Jiang, Xiaodong; Wu, Weidong; Zheng, Wanguo; Tang, Yongjian

    2013-11-01

    In order to explore the damage mechanisms of K9 glass irradiated by high energy density ultraviolet laser, laser-induced fluorescence and Raman spectra were investigated. Compared the fluorescence spectra of damaged area, undamaged area and sub-damaged area, it can be conclude that the fluorescence spectrum of sub-damaged area is different from the structure of the other two areas. Especially, the main peak of the spectra at 415 nm reveals the unique characteristics of K9 glass. The structure at the sub-damaged area enhances intensity of the Raman scattering spectra. Three peaks of the spectra at about 500 nm and two characteristic peaks at about 550 nm exhibit the characterization of damaged area. A peak of the Raman scattering spectra at 350 nm which related to water can be observed. The relationship between intensity of Raman scattering and laser intensity at 355 nm is investigated by confocal Raman microscopy. At sub-damage area, signal of Raman scattering is rather high and decreased dramatically with respect to energy density. The major band at about 1470 cm-1 sharpened and moved to higher frequency with densification. These phenomena demonstrate that the structure of sub-damaged area has some characterization compared with the damaged area. The investigation of defect induced fluorescence and Raman spectra on surface of K9 glass is important to explore the damage mechanisms of optical materials irradiated by ultraviolet laser irradiation at 355 nm.

  4. Diffusion measurements by Raman spectroscopy

    DEFF Research Database (Denmark)

    Hansen, Susanne Brunsgaard; Shapiro, Alexander; Berg, Rolf W.;

    Poster "Diffusion measurements by Raman spectroscopy", See poster at http://www.kemi.dtu.dk/~ajo/rolf/petroday2004.ppt......Poster "Diffusion measurements by Raman spectroscopy", See poster at http://www.kemi.dtu.dk/~ajo/rolf/petroday2004.ppt...

  5. Diffusion measurements by Raman spectroscopy

    DEFF Research Database (Denmark)

    Hansen, Susanne Brunsgaard; Shapiro, Alexander; Berg, Rolf W.

    Poster "Diffusion measurements by Raman spectroscopy", See poster at http://www.kemi.dtu.dk/~ajo/rolf/petroday2004.ppt......Poster "Diffusion measurements by Raman spectroscopy", See poster at http://www.kemi.dtu.dk/~ajo/rolf/petroday2004.ppt...

  6. Blood analysis by Raman spectroscopy

    Science.gov (United States)

    Enejder, Annika M. K.; Koo, Tae-Woong; Oh, Jeankun; Hunter, Martin; Sasic, Slobodan; Feld, Michael S.; Horowitz, Gary L.

    2002-11-01

    Concentrations of multiple analytes were simultaneously measured in whole blood with clinical accuracy, without sample processing, using near-infrared Raman spectroscopy. Spectra were acquired with an instrument employing nonimaging optics, designed using Monte Carlo simulations of the influence of light-scattering-absorbing blood cells on the excitation and emission of Raman light in turbid medium. Raman spectra were collected from whole blood drawn from 31 individuals. Quantitative predictions of glucose, urea, total protein, albumin, triglycerides, hematocrit, and hemoglobin were made by means of partial least-squares (PLS) analysis with clinically relevant precision (r2 values >0.93). The similarity of the features of the PLS calibration spectra to those of the respective analyte spectra illustrates that the predictions are based on molecular information carried by the Raman light. This demonstrates the feasibility of using Raman spectroscopy for quantitative measurements of biomolecular contents in highly light-scattering and absorbing media.

  7. Raman Spectroscopy for Clinical Oncology

    Directory of Open Access Journals (Sweden)

    Michael B. Fenn

    2011-01-01

    Full Text Available Cancer is one of the leading causes of death throughout the world. Advancements in early and improved diagnosis could help prevent a significant number of these deaths. Raman spectroscopy is a vibrational spectroscopic technique which has received considerable attention recently with regards to applications in clinical oncology. Raman spectroscopy has the potential not only to improve diagnosis of cancer but also to advance the treatment of cancer. A number of studies have investigated Raman spectroscopy for its potential to improve diagnosis and treatment of a wide variety of cancers. In this paper the most recent advances in dispersive Raman spectroscopy, which have demonstrated promising leads to real world application for clinical oncology are reviewed. The application of Raman spectroscopy to breast, brain, skin, cervical, gastrointestinal, oral, and lung cancers is reviewed as well as a special focus on the data analysis techniques, which have been employed in the studies.

  8. All-Fiber Raman Probe

    DEFF Research Database (Denmark)

    Brunetti, Anna Chiara

    The design and development of an all-in-fiber probe for Raman spectroscopy are presented in this Thesis. Raman spectroscopy is an optical technique able to probe a sample based on the inelastic scattering of monochromatic light. Due to its high specificity and reliability and to the possibility...... to perform real-time measurements with little or no sample preparation, Raman spectroscopy is now considered an invaluable analytical tool, finding application in several fields including medicine, defense and process control. When combined with fiber optics technology, Raman spectroscopy allows...... for the realization of flexible and minimally-invasive devices, able to reach remote or hardly accessible samples, and to perform in-situ analyses in hazardous environments. The work behind this Thesis focuses on the proof-of-principle demonstration of a truly in-fiber Raman probe, where all parts are realized...

  9. Non-resonant wavelength modulation saturation spectroscopy in acetylene-filled hollow-core photonic bandgap fibres applied to modulation-free laser diode stabilisation.

    Science.gov (United States)

    Pineda-Vadillo, Pablo; Lynch, Michael; Charlton, Christy; Donegan, John F; Weldon, Vincent

    2009-12-07

    In this paper the application of Wavelength Modulation (WM) techniques to non-resonant saturation spectroscopy in acetylene-filled Hollow-Core Photonic Bandgap Fibres (HC-PBFs) and modulation-free Laser Diode (LD) frequency stabilisation is investigated. In the first part WM techniques are applied to non-resonant pump-probe saturation of acetylene overtone rotational transitions in a HC-PBF. A high-power DFB chip-on-carrier mounted LD is used in conjunction with a tuneable External Cavity Laser (ECL) and the main saturation parameters are characterized. In the second part a novel feedback system to stabilize the DFB emission wavelength based on the WM saturation results is implemented. Modulation-free locking of the DFB laser frequency to the narrow linewidth saturation feature is achieved for both constant and variable LD temperatures.

  10. 3-D laser confocal microscopy study of the oxidation of NdFeB magnets in atmospheric conditions

    Science.gov (United States)

    Meakin, J. P.; Speight, J. D.; Sheridan, R. S.; Bradshaw, A.; Harris, I. R.; Williams, A. J.; Walton, A.

    2016-08-01

    Neodymium iron boron (NdFeB) magnets are used in a number of important applications, such as generators in gearless wind turbines, motors in electric vehicles and electronic goods (e.g.- computer hard disk drives, HDD). Hydrogen can be used as a processing gas to separate and recycle scrap sintered Nd-Fe-B magnets from end-of-life products to form a powder suitable for recycling. However, the magnets are likely to have been exposed to atmospheric conditions prior to processing, and any oxidation could lead to activation problems for the hydrogen decrepitation reaction. Many previous studies on the oxidation of NdFeB magnets have been performed at elevated temperatures; however, few studies have been formed under atmospheric conditions. In this paper a combination of 3-D laser confocal microscopy and Raman spectroscopy have been used to assess the composition, morphology and rate of oxidation/corrosion on scrap sintered NdFeB magnets. Confocal microscopy has been employed to measure the growth of surface reaction products at room temperature, immediately after exposure to air. The results showed that there was a significant height increase at the triple junctions of the Nd-rich grain boundaries. Using Raman spectroscopy, the product was shown to consist of Nd2O3 and formed only on the Nd-rich triple junctions. The diffusion coefficient of the triple junction reaction product growth at 20 °C was determined to be approximately 4 × 10-13 cm2/sec. This value is several orders of magnitude larger than values derived from the diffusion controlled oxide growth observations at elevated temperatures in the literature. This indicates that the growth of the room temperature oxidation products are likely defect enhanced processes at the NdFeB triple junctions.

  11. Raman spectral study of anti-angiogenic drugs on the role of chick vascular

    Science.gov (United States)

    Huang, Ruixiang; Chen, Rong; Chen, Qisong; Lin, Juqiang; Pan, Jianji; Lin, Shaojun; Li, Chao; Li, Yongzeng; Feng, Shangyuan

    2009-08-01

    Inhibit angiogenesis is one of the important tumor therapy. If the mechanism of vascular changes can be detected at molecular level, it will have therapeutic significance. Raman spectroscopy, which can be applied to the structural analysis of solid, liquid or solution of biological molecules, is a non-destructive spectral technology holding very rich information. Basing on Confocal Raman Microscope, a unique system is developed for obtaining the different Raman spectra of the chick embryo vascular with the anti-angiogenic drugs - thalidomide and without. In the study, the location and shape of the average Raman spectra of vessels in drug 5h were very similar to the ones without medicine, and the intensity of some characteristic peaks changed, such as 1441cm-1,1527cm-1 and 1657cm-1 showing markedly increasing, while the 971cm-1 and 1081cm-1 decreasing. This change was due to anti- angiogenic drugs that caused the nucleic acid, protein, phospholipids, and other important biological molecules of the vessels on the structure or content tovary. PCA was used to distinguish between the two kinds of vascular with the result that they were accurately partitioned.The study indicated that Raman spectroscopy could be an effective tool for detection of the mechanism of vascular changes.

  12. Noise Removal with Maintained Spatial Resolution in Raman Images of Cells Exposed to Submicron Polystyrene Particles

    Directory of Open Access Journals (Sweden)

    Linnea Ahlinder

    2016-04-01

    Full Text Available The biodistribution of 300 nm polystyrene particles in A549 lung epithelial cells has been studied with confocal Raman spectroscopy. This is a label-free method in which particles and cells can be imaged without using dyes or fluorescent labels. The main drawback with Raman imaging is the comparatively low spatial resolution, which is aggravated in heterogeneous systems such as biological samples, which in addition often require long measurement times because of their weak Raman signal. Long measurement times may however induce laser-induced damage. In this study we use a super-resolution algorithm with Tikhonov regularization, intended to improve the image quality without demanding an increased number of collected pixels. Images of cells exposed to polystyrene particles have been acquired with two different step lengths, i.e., the distance between pixels, and compared to each other and to corresponding images treated with the super-resolution algorithm. It is shown that the resolution after application of super-resolution algorithms is not significantly improved compared to the theoretical limit for optical microscopy. However, to reduce noise and artefacts in the hyperspectral Raman images while maintaining the spatial resolution, we show that it is advantageous to use short mapping step lengths and super-resolution algorithms with appropriate regularization. The proposed methodology should be generally applicable for Raman imaging of biological samples and other photo-sensitive samples.

  13. Probing Xylan-Specific Raman Bands for Label-Free Imaging Xylan in Plant Cell Wall

    Energy Technology Data Exchange (ETDEWEB)

    Zeng, Yining; Yarbrough, John M.; Mittal, Ashutosh; Tucker, Melvin P.; Vinzant, Todd; Himmel, Michael E.

    2015-06-15

    Xylan constitutes a significant portion of biomass (e.g. 22% in corn stover used in this study). Xylan is also an important source of carbohydrates, besides cellulose, for renewable and sustainable energy applications. Currently used method for the localization of xylan in biomass is to use fluorescence confocal microscope to image the fluorescent dye labeled monoclonal antibody that specifically binds to xylan. With the rapid adoption of the Raman-based label-free chemical imaging techniques in biology, identifying Raman bands that are unique to xylan would be critical for the implementation of the above label-free techniques for in situ xylan imaging. Unlike lignin and cellulose that have long be assigned fingerprint Raman bands, specific Raman bands for xylan remain unclear. The major challenge is the cellulose in plant cell wall, which has chemical units highly similar to that of xylan. Here we report using xylanase to specifically remove xylan from feedstock. Under various degree of xylan removal, with minimum impact to other major cell wall components, i.e. lignin and cellulose, we have identified Raman bands that could be further tested for chemical imaging of xylan in biomass in situ.

  14. Stable optical trapping and sensitive characterization of nanostructures using standing-wave Raman tweezers

    Science.gov (United States)

    Wu, Mu-ying; Ling, Dong-xiong; Ling, Lin; Li, William; Li, Yong-qing

    2017-01-01

    Optical manipulation and label-free characterization of nanoscale structures open up new possibilities for assembly and control of nanodevices and biomolecules. Optical tweezers integrated with Raman spectroscopy allows analyzing a single trapped particle, but is generally less effective for individual nanoparticles. The main challenge is the weak gradient force on nanoparticles that is insufficient to overcome the destabilizing effect of scattering force and Brownian motion. Here, we present standing-wave Raman tweezers for stable trapping and sensitive characterization of single isolated nanostructures with a low laser power by combining a standing-wave optical trap with confocal Raman spectroscopy. This scheme has stronger intensity gradients and balanced scattering forces, and thus can be used to analyze many nanoparticles that cannot be measured with single-beam Raman tweezers, including individual single-walled carbon nanotubes (SWCNT), graphene flakes, biological particles, SERS-active metal nanoparticles, and high-refractive semiconductor nanoparticles. This would enable sorting and characterization of specific SWCNTs and other nanoparticles based on their increased Raman fingerprints. PMID:28211526

  15. Determination of HER2 amplification status in breast cancer cells using Raman spectroscopy

    Science.gov (United States)

    Bi, Xiaohong; Rexer, Brent; Arteaga, Carlos L.; Guo, Mingsheng; Li, Ming; Mahadevan-Jansen, Anita

    2010-02-01

    The overexpression of HER2 (human epidermal growth factor receptor 2) in breast cancer is associated with increased disease recurrence and worse prognosis. Current diagnosis of HER2 positive breast cancer is time consuming with an estimated 20% inaccuracy. Raman spectroscopy is a proven method for pathological diagnosis based on the molecular composition of tissues. This study aimed to determine the feasibility of Raman spectroscopy to differentially identify the amplification of HER2 in cells. Three cell lines including BT474 (HER2 overexpressing breast cancer cell), MCF-10A (human breast epithelial cell), and MCF-10A with overexpressing HER2, were investigated using a bench top confocal Raman system. A diagnostic algorithm based on generalized linear model (GLM) with elastic-net penalties was established to discriminate 318 spectra collected from the cells, and to identify the spectra regions that differentiate the cell lines. The algorithm was able to differentially identify BT474 breast cancer cells with an overall sensitivity of 100% and specificity of 99%. The results demonstrate the capability of Raman spectroscopy to determine HER2 status in cells. Raman spectroscopy shows promise for application in the diagnosis of HER2 positive breast cancer in clinical practice.

  16. Raman Submicron Spatial Mapping of Individual Mn-doped ZnO Nanorods.

    Science.gov (United States)

    Strelchuk, V; Kolomys, O; Rarata, S; Lytvyn, P; Khyzhun, O; Chey, Chan Oeurn; Nur, Omer; Willander, Magnus

    2017-12-01

    ZnO nanorods (NRs) arrays doped with a large concentration of Mn synthesized by aqueous chemical growth and were characterized by SEM, photoluminescence, Raman scattering, magnetic force microscopy (MFM). By comparison of spectra taken on pure and Mn-doped ZnO NRs, a few new Raman impurity-related phonon modes, resulting from the presence of Mn in the investigated samples. We also present a vibrational and magnetic characterization of individual lying nanorods using Raman and MFM imaging. Confocal scanning micro-Raman mapping of the spatial distribution of intensity and frequency of phonon modes in single Mn-doped ZnO NRs nanorods is presented and analyzed for the first time. Mn-related local vibrational modes are also registered in Raman spectra of the single nanorod, confirming the incorporation of Mn into the ZnO host matrix. At higher Mn concentration the structural transformation toward the spinel phase ZnMn2O4 and Mn3O4 is observed mainly in 2D bottom layers. MFM images of Mn-doped ZnO NR arrays and single nanorod were studied in nanoscale at room temperature and demonstrate magnetic behavior. The circular domain magnetic pattern on top of single nanorod originated to superposition of some separate domains inside rod. This demonstrates that long-range ferromagnetic order is present at room temperature. Aligned Mn-doped ZnO NRs demonstrates that long-range ferromagnetic order and may be applied to future spintronic applications.

  17. [Red Blood Cells Raman Spectroscopy Comparison of Type Two Diabetes Patients and Rats].

    Science.gov (United States)

    Wang, Lei; Liu, Gui-dong; Mu, Xin; Xiao, Hong-bin; Qi, Chao; Zhang, Si-qi; Niu Wen-ying; Jiang, Guang-kun; Feng, Yue-nan; Bian, Jing-qi

    2015-10-01

    By using confocal Raman spectroscopy, Raman spectra were measured in normal rat red blood cells, normal human red blood cells, STZ induced diabetetic rats red blood cells, Alloxan induced diabetetic rats red blood cells and human type 2 diabetes red blood cells. Then principal component analysis (PCA) with support vector machine (SVM) classifier was used for data analysis, and then the distance between classes was used to judge the degree of close to two kinds of rat model with type 2 diabetes. The results found significant differences in the Raman spectra of red blood cell in diabetic and normal red blood cells. To diabetic red blood cells, the peak in the amide VI C=O deformation vibration band is obvious, and amide V N-H deformation vibration band spectral lines appear deviation. Belong to phospholipid fatty acyl C-C skeleton, the 1 130 cm(-1) spectral line is enhanced and the 1 088 cm(-1) spectral line is abated, which show diabetes red cell membrane permeability increased. Raman spectra of PCA combined with SVM can well separate 5 types of red blood cells. Classifier test results show that the classification accuracy is up to 100%. Through the class distance between the two induced method and human type 2 diabetes, it is found that STZ induced model is more close to human type 2 diabetes. In conclusion, Raman spectroscopy can be used for diagnosis of diabetes and rats STZ induced diabetes method is closer to human type 2 diabetes.

  18. Stable optical trapping and sensitive characterization of nanostructures using standing-wave Raman tweezers

    Science.gov (United States)

    Wu, Mu-Ying; Ling, Dong-Xiong; Ling, Lin; Li, William; Li, Yong-Qing

    2017-02-01

    Optical manipulation and label-free characterization of nanoscale structures open up new possibilities for assembly and control of nanodevices and biomolecules. Optical tweezers integrated with Raman spectroscopy allows analyzing a single trapped particle, but is generally less effective for individual nanoparticles. The main challenge is the weak gradient force on nanoparticles that is insufficient to overcome the destabilizing effect of scattering force and Brownian motion. Here, we present standing-wave Raman tweezers for stable trapping and sensitive characterization of single isolated nanostructures with a low laser power by combining a standing-wave optical trap with confocal Raman spectroscopy. This scheme has stronger intensity gradients and balanced scattering forces, and thus can be used to analyze many nanoparticles that cannot be measured with single-beam Raman tweezers, including individual single-walled carbon nanotubes (SWCNT), graphene flakes, biological particles, SERS-active metal nanoparticles, and high-refractive semiconductor nanoparticles. This would enable sorting and characterization of specific SWCNTs and other nanoparticles based on their increased Raman fingerprints.

  19. Stimulated emission of free excitons in Cd{sub 1-x}Mn{sub x}Te under nonresonant two-photon excitation

    Energy Technology Data Exchange (ETDEWEB)

    Jang, J.I. [Department of Physics and Astronomy, Northwestern University, 2145 Sheridan Road, Evanston, IL 60208 (United States)], E-mail: joon-jang@northwestern.edu; Mani, S.; Ketterson, J.B. [Department of Physics and Astronomy, Northwestern University, 2145 Sheridan Road, Evanston, IL 60208 (United States); Park, H.Y. [Department of Semiconductor Applications, Ulsan College, San 29 Mugeo Dong, Ulsan 680-749 (Korea, Republic of)], E-mail: hypark@mail.uc.ac.kr

    2008-08-25

    We report on free excitons coexisting with exciton magnetic polarons (EMPs) in bulk semimagnetic semiconductors of Cd{sub 1-x}Mn{sub x}Te for 0.04{<=}x{<=}0.36 at 2 K under nonresonant two-photon excitation. This two-photon excitation not only generates free excitons but also more efficiently creates EMPs compared with ordinary one-photon excitation. Stimulated emission from free excitons is demonstrated under strong two-photon excitation.

  20. Laser differential fitting confocal microscopy with high imaging efficiency.

    Science.gov (United States)

    Sheng, Zhong; Wang, Yun; Zhao, Weiqian; Qiu, Lirong; Sun, Yingbin

    2016-09-01

    Based on the optical arrangement of a bipolar differential confocal microscopy (BDCM), laser differential fitting confocal microscopy (DFCM) is proposed in this paper using the feature of BDCM that a zero-crossing point (ZCP) of the axial response curve precisely corresponds to the focus of the system objective. A linear segment of the DFCM axial response around the ZCP is used to fit a straight line. Focus can be determined by solving the equations of the fitting lines, and then, the sample surface could be measured and reconstructed with a high resolution. Compared with the curve-fitting peak detection, which is an algorithm for focus detection widely used in conventional confocal microscopy, the line-fitting zero solution method used in DFCM has several advantages, such as high precision and sensitivity. Most importantly, precise focus detection can be realized using less data, i.e., DFCM has a high measurement efficiency. Furthermore, DFCM can effectively eliminate common-mode noise in a confocal microscopy system and has good noise suppression and disturbance resistance capability.

  1. Optomechatronics Design and Control for Confocal Laser Scanning Microscopy

    NARCIS (Netherlands)

    Yoo, H.W.

    2015-01-01

    Confocal laser scanning microscopy (CLSM) is considered as one of the major advancements in microscopy in the last century and is widely accepted as a 3D fluorescence imaging tool for biological studies. For the emerging biological questions CLSM requires fast imaging to detect rapid biological proc

  2. CONFOCAL MICROSCOPY SYSTEM PERFORMANCE: SPECTROSCOPY AND FOUNDATIONS FOR QUANTITATION

    Science.gov (United States)

    The confocal laser-scanning microscope (CLSM) has enormous potential in many biological fields. The reliability of the CLSM to obtain specific measurements and quantify fluorescence data is dependent on using a correctly aligned machine that contains a stable laser power. For man...

  3. Optomechatronics Design and Control for Confocal Laser Scanning Microscopy

    NARCIS (Netherlands)

    Yoo, H.W.

    2015-01-01

    Confocal laser scanning microscopy (CLSM) is considered as one of the major advancements in microscopy in the last century and is widely accepted as a 3D fluorescence imaging tool for biological studies. For the emerging biological questions CLSM requires fast imaging to detect rapid biological

  4. Nonlinear Image Restoration in Confocal Microscopy : Stability under Noise

    NARCIS (Netherlands)

    Roerdink, J.B.T.M.

    1995-01-01

    In this paper we study the noise stability of iterative algorithms developed for attenuation correction in Fluorescence Confocal Microscopy using FT methods. In each iteration the convolution of the previous estimate is computed. It turns out that the estimators are robust to noise perturbation.

  5. Analysis of confocal microscopy under ultrashort light-pulse illumination

    Energy Technology Data Exchange (ETDEWEB)

    Kempe, M.; Rudolph, W. (Univ. of New Mexico, Albuquerque (United States))

    1993-02-01

    The resolution of confocal laser scanning microscopes is analyzed if they are used in measurements that are to combine high spatial and high temporal resoltuion. A generalized Fourier-optical treatment is developed in which the system characteristics contain all necessary information regarding the optical arrangement and the illuminating light pulses. Coherent and incoherent imaging are considered in detail. 10 refs., 8 figs.

  6. Nonlinear Image Restoration in Confocal Microscopy : Stability under Noise

    NARCIS (Netherlands)

    Roerdink, J.B.T.M.

    1995-01-01

    In this paper we study the noise stability of iterative algorithms developed for attenuation correction in Fluorescence Confocal Microscopy using FT methods. In each iteration the convolution of the previous estimate is computed. It turns out that the estimators are robust to noise perturbation.

  7. Nuclear area measurement on viable cells, using confocal microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Townsend, K.M.S.; Marsden, S.J. (Medical Research Council, Harwell (United Kingdom). Radiobiological Research Unit)

    1992-04-01

    The authors describe a rapid procedure for the accurate measurement of nuclear areas on unperturbed living cells as used in radiobiological experiments, using the confocal laser scanning microscope. The microdosimetric interpretation of radiobiological data requires precise information on the nuclear area of cells as irradiated with high-LET radiation. (author).

  8. Background-free coherent anti-stokes Raman spectroscopy and microscopy by dual-soliton pulse generation

    CERN Document Server

    Chen, Kun; Wei, Haoyun; Li, Yan

    2016-01-01

    We propose an all-fiber-generated dual-soliton pulses based scheme for the background-free detection of coherent anti-Stokes Raman spectroscopy under the spectral focusing mechanism. Due to the strong birefringence and high nonlinearity of a polarization-maintaining photonic crystal fiber (PM-PCF), two redshifted soliton pulses can be simultaneously generated relying on high-order dispersion and nonlinear effects along two eigenpolarization axes in the anomalous dispersion regime, while allowing feasible tunability of the frequency distance and temporal interval between them. This proposed scheme, termed as DS-CARS, exploits a unique combination of slight frequency-shift and advisable temporal walk-off of this two soliton pulses to achieve robust and efficient suppression of nonresonant background with compact all-fiber coherent excitation source. Capability of the DS-CARS is experimentally demonstrated by the background-free CARS spectroscopy and unambiguous CARS microscopy of polymer beads in the fingerprin...

  9. Amplification of Surface-Enhanced Raman Scattering Due to Substrate-Mediated Localized Surface Plasmons in Gold Nanodimers

    KAUST Repository

    Yue, Weisheng

    2017-03-28

    Surface-enhanced Raman scattering (SERS) is ubiquitous in chemical and biochemical sensing, imaging and identification. Maximizing SERS enhancement is a continuous effort focused on the design of appropriate SERS substrates. Here we show that significant improvement in a SERS signal can be achieved with substrates combining localized surface plasmon resonances and a nonresonant plasmonic substrate. By introducing a continuous gold (Au) film underneath Au nanodimers antenna arrays, an over 10-fold increase in SERS enhancement is demonstrated. Triangular, rectangle and disc dimers were studied, with bowtie antenna providing highest SERS enhancement. Simulations of electromagnetic field distributions of the Au nanodimers on the Au film support the observed enhancement dependences. The hybridization of localized plasmonic modes with the image modes in a metal film provides a straightforward way to improve SERS enhancement in designer SERS substrate.

  10. Selective excitation of molecular mode in a mixture by femtosecond resonance-enhanced coherent anti-Stokes Raman scattering spectroscopy

    Institute of Scientific and Technical Information of China (English)

    He Ping; Li Si-Ning; Fan Rong-Wei; Li Xiao-Hui; Xia Yuan-Qin; Yu Xin; Chen De-Ying

    2012-01-01

    Femtosecond time-resolved coherent anti-Stokes Raman scattering (CARS) spectroscopy is used to investigate gaseous molecular dynamics.Due to the spectrally broad laser pulses,usually poorly resolved spectra result from this broad spectroscopy.However,it can be demonstrated that by the electronic resonance enhancement optimization control a selective excitation of specific vibrational mode is possible.Using an electronically resonance-enhanced effect,iodine molecule specific CARS spectroscopy can be obtained from a mixture of iodine-air at room temperature and a pressure of 1 atm (corresponding to a saturation iodine vapour as low as about 35 Pa).The dynamics on either the electronically excited state or the ground state of iodine molecules obtained is consistent with previous studies (vacuum,heated and pure iodine) in the femtosecond time resolved CARS spectroscopy,showing that an effective method of suppressing the non-resonant CARS background and other interferences is demonstrated.

  11. Evaluation of toroidal torque by non-resonant magnetic perturbations in tokamaks for resonant transport regimes using a Hamiltonian approach

    Science.gov (United States)

    Albert, Christopher G.; Heyn, Martin F.; Kapper, Gernot; Kasilov, Sergei V.; Kernbichler, Winfried; Martitsch, Andreas F.

    2016-08-01

    Toroidal torque generated by neoclassical viscosity caused by external non-resonant, non-axisymmetric perturbations has a significant influence on toroidal plasma rotation in tokamaks. In this article, a derivation for the expressions of toroidal torque and radial transport in resonant regimes is provided within quasilinear theory in canonical action-angle variables. The proposed approach treats all low-collisional quasilinear resonant neoclassical toroidal viscosity regimes including superbanana-plateau and drift-orbit resonances in a unified way and allows for magnetic drift in all regimes. It is valid for perturbations on toroidally symmetric flux surfaces of the unperturbed equilibrium without specific assumptions on geometry or aspect ratio. The resulting expressions are shown to match the existing analytical results in the large aspect ratio limit. Numerical results from the newly developed code NEO-RT are compared to calculations by the quasilinear version of the code NEO-2 at low collisionalities. The importance of the magnetic shear term in the magnetic drift frequency and a significant effect of the magnetic drift on drift-orbit resonances are demonstrated.

  12. Temperature-dependent cross sections for πΦ and pΦ nonresonant reactions in hadronic matter

    Institute of Scientific and Technical Information of China (English)

    LUO Zhi-Feng; XU Xiao-Ming

    2012-01-01

    With a potential of which the large-distance part reflects lattice gauge results and of which the short-distance part is given by one gluon exchange plus perturbative one- and two-loop corrections,the Schr(o)dinger equation brings about temperature dependence of meson masses and mesonic quark-antiquark relative-motion wave functions.The ground-state meson masses drop with increasing temperature.The transition amplitude calculated from the potential,the meson masses and the wave functions gives temperaturedependent cross sections for the five nonresonant reactions πΦ → K(K)* (or K*(K)),πΦ → K*(K)*,pΦ → K(K),pΦ → K(K)* (or K*(K)) and ΡΦ → K*(K)*.The numerical temperature-dependent cross sections are parametrized.The peak cross section of either πΦ → K(K)* or πΦ → K*(K)* increases from T =0 to T =0.75Tc and decreases with further increasing temperature.The cross section for pΦ → K(K),pΦ → K(K)* or pΦ → K*(K)* has a decreasing trend while the temperature increases from 0.75Tc.

  13. Search for B0 -> rho0rho0 and Non-Resonant B0 -> 4pi Decays

    CERN Document Server

    Abe, K; Arinstein, K; Aso, T; Aulchenko, V; Aushev, T; Aziz, T; Bahinipati, S; Bakich, A M; Balagura, V; Ban, Y; Banerjee, S; Barberio, E; Bay, A; Bedny, I; Belous, K S; Bhardwaj, V; Bitenc, U; Blyth, S; Bondar, A; Bozek, A; Bracko, M; Brodzicka, J; Browder, T E; Chang, M C; Chang, P; Chao, Y; Chen, A; Chen, K F; Chen, W T; Cheon, B G; Chiang, C C; Chistov, R; Cho, I S; Choi, S K; Choi, Y; Choi, Y K; Cole, S; Dalseno, J; Danilov, M; Das, A; Dash, M; Dragic, J; Drutskoy, A; Eidelman, S; Epifanov, D; Fratina, S; Fujii, H; Fujikawa, M; Gabyshev, N; Garmash, A; Go, A; Gokhroo, G; Goldenzweig, P; Golob, B; Grosse-Perdekamp, M; Guler, H; Ha, H; Haba, J; Hara, K; Hara, T; Hasegawa, Y; Hastings, N C; Hayasaka, K; Hayashii, H; Hazumi, M; Heffernan, D; Higuchi, T; Hinz, L; Hoedlmoser, H; Hokuue, T; Horii, Y; Hoshi, Y; Hoshina, K; Hou, S; Hou, W S; Hsiung, Y B; Hyun, H J; Igarashi, Y; Iijima, T; Ikado, K; Inami, K; Ishikawa, A; Ishino, H; Itoh, R; Iwabuchi, M; Iwasaki, M; Iwasaki, Y; Jacoby, C; Joshi, N J; Kaga, M; Kah, D H; Kaji, H; Kajiwara, S; Kakuno, H; Kang, J H; Kapusta, P; Kataoka, S U; Katayama, N; Kawai, H; Kawasaki, T; Kibayashi, A; Kichimi, H; Kim, H J; Kim, H O; Kim, J H; Kim, S K; Kim, Y J; Kinoshita, K; Korpar, S; Kozakai, Y; Krizan, P; Krokovny, P; Kumar, R; Kurihara, E; Kusaka, A; Kuzmin, A; Kwon, Y J; Lange, J S; Leder, G; Lee, J; Lee, J S; Lee, M J; Lee, S E; Lesiak, T; Li, J; Limosani, A; Lin, S W; Liu, Y; Liventsev, D; MacNaughton, J; Majumder, G; Mandl, F; Marlow, D; Matsumura, T; Matyja, A; McOnie, S; Medvedeva, T; Mikami, Y; Mitaroff, W A; Miyabayashi, K; Miyake, H; Miyata, H; Miyazaki, Y; Mizuk, R; Moloney, G R; Mori, T; Müller, J; Murakami, A; Nagamine, T; Nagasaka, Y; Nakahama, Y; Nakamura, I; Nakano, E; Nakao, M; Nakayama, H; Nakazawa, H; Natkaniec, Z; Neichi, K; Nishida, S; Nishimura, K; Nishio, Y; Nishizawa, I; Nitoh, O; Noguchi, S; Nozaki, T; Ogawa, A; Ogawa, S; Ohshima, T; Okuno, S; Olsen, S L; Ono, S; Ostrowicz, W; Ozaki, H; Pakhlov, P; Pakhlova, G; Palka, H; Park, C W; Park, H; Park, K S; Parslow, N; Peak, L S; Pernicka, M; Pestotnik, R; Peters, M; Piilonen, L E; Poluektov, A; Rorie, J; Rózanska, M; Sahoo, H; Sakai, Y; Sakamoto, H; Sakaue, H; Sarangi, T R; Satoyama, N; Sayeed, K; Schietinger, T; Schneider, O; Schonmeier, P; Schümann, J; Schwanda, C; Schwartz, A J; Seidl, R; Sekiya, A; Senyo, K; Sevior, M E; Shang, L; Shapkin, M; Shen, C P; Shibuya, H; Shinomiya, S; Shiu, J G; Shwartz, B; Singh, J B; Sokolov, A; Solovieva, E; Somov, A; Stanic, S; Staric, M; Stypula, J; Sugiyama, A; Sumisawa, K; Sumiyoshi, T; Suzuki, S; Suzuki, S Y; Tajima, O; Takasaki, F; Tamai, K; Tamura, N; Tanaka, M; Taniguchi, N; Taylor, G N; Teramoto, Y; Tikhomirov, I; Trabelsi, K; Tse, Y F; Tsuboyama, T; Uchida, K; Uchida, Y; Uehara, S; Ueno, K; Uglov, T; Unno, Y; Uno, S; Urquijo, P; Ushiroda, Y; Usov, Yu; Varner, G; Varvell, K E; Vervink, K; Villa, S; Vinokurova, A; Wang, C C; Wang, C H; Wang, J; Wang, M Z; Wang, P; Wang, X L; Watanabe, M; Watanabe, Y; Wedd, R; Wicht, J; Widhalm, L; Wiechczynski, J; Won, E; Yabsley, B D; Yamaguchi, A; Yamamoto, H; Yamaoka, M; Yamashita, Y; Yamauchi, M; Yuan, C Z; Yusa, Y; Zhang, C C; Zhang, L M; Zhang, Z P; Zhilich, V; Zhulanov, V; Zupanc, A; Zwahlen, N

    2007-01-01

    We search for the decay B0 -> rho0rho0 and other possible charmless modes with a pi+pi-pi+pi- final state, including B0 -> rho0f0(980), B0 -> f0(980)f0(980), B0 -> f0(980)pipi, B0 -> rho0pipi and non-resonant B0 -> 4pi. These results are obtained from a data sample containing 520 x 10^6 BBar pairs collected by the Belle detector at the KEKB asymmetric-energy e+e- collider. We measure a branching fraction of (0.9 +/- 0.4^{+0.3}_{-0.4}) x 10^{-6}, or B(B0 -> rho0rho0) 4pi decay to be (10.2 +/- 4.7^{+2.3}_{-1.5}) x 10^{-6} with 2.1\\sigma significance, and set the 90% confidence level upper limit B(B0 -> 4pi) rho0f0(980), B0 -> f0(980)f0(980), B0 -> f0(980)pipi and B0 -> rho0pipi, no significant signals are observed and upper limits on the branching fractions are set.

  14. An efficient nonclassical quadrature for the calculation of nonresonant nuclear fusion reaction rate coefficients from cross section data

    Science.gov (United States)

    Shizgal, Bernie D.

    2016-08-01

    Nonclassical quadratures based on a new set of half-range polynomials, Tn(x) , orthogonal with respect to w(x) =e - x - b /√{ x } for x ∈ [ 0 , ∞) are employed in the efficient calculation of the nuclear fusion reaction rate coefficients from cross section data. The parameter b = B /√{kB T } in the weight function is temperature dependent and B is the Gamow factor. The polynomials Tn(x) satisfy a three term recurrence relation defined by two sets of recurrence coefficients, αn and βn. These recurrence coefficients define in turn the tridiagonal Jacobi matrix whose eigenvalues are the quadrature points and the weights are calculated from the first components of the eigenfunctions. For nonresonant nuclear reactions for which the astrophysical function can be expressed as a lower order polynomial in the relative energy, the convergence of the thermal average of the reactive cross section with this nonclassical quadrature is extremely rapid requiring in many cases 2-4 quadrature points. The results are compared with other libraries of nuclear reaction rate coefficient data reported in the literature.

  15. Study of the Verwey transition in magnetite by low field and magnetically modulated non-resonant microwave absorption

    Energy Technology Data Exchange (ETDEWEB)

    Gutierrez, M.P. [Escuela Superior de Fisica y Matematicas del Instituto Politecnico Nacional, Mexico, D.F. 07738 (Mexico)]. E-mail: mpga@servidor.unam.mx; Alvarez, G. [Instituto de Investigaciones en Materiales de la Universidad Nacional Autonoma de Mexico, Mexico, D.F. 04510 (Mexico); Montiel, H. [Centro de Ciencias Aplicadas y Desarrollo Tecnologico de la Universidad Nacional Autonoma de Mexico, Mexico, D.F. 04510 (Mexico); Zamorano, R. [Escuela Superior de Fisica y Matematicas del Instituto Politecnico Nacional, Mexico, D.F. 07738 (Mexico); Valenzuela, R. [Instituto de Investigaciones en Materiales de la Universidad Nacional Autonoma de Mexico, Mexico, D.F. 04510 (Mexico)

    2007-09-15

    We have investigated the Verwey phase transition (VPT) by two novel non-resonant microwave absorption techniques: low-field absorption (LFA) and magnetically modulated microwave absorption spectroscopy (MAMMAS). Measurements were carried out on sintered polycrystalline samples of Fe{sub 3}O{sub 4}, in the 77-300 K temperature range. LFA refers to the microwave absorption around the zero DC field range (-1000

  16. Evaluation of the toroidal torque driven by external non-resonant non-axisymmetric magnetic field perturbations in a tokamak

    Energy Technology Data Exchange (ETDEWEB)

    Kasilov, Sergei V. [Fusion@ÖAW, Institut für Theoretische Physik—Computational Physics, Technische Universität Graz Petersgasse 16, A–8010 Graz (Austria); Institute of Plasma Physics National Science Center “Kharkov Institute of Physics and Technology” ul. Akademicheskaya 1, 61108 Kharkov (Ukraine); Kernbichler, Winfried; Martitsch, Andreas F.; Heyn, Martin F. [Fusion@ÖAW, Institut für Theoretische Physik—Computational Physics, Technische Universität Graz Petersgasse 16, A–8010 Graz (Austria); Maassberg, Henning [Max-Planck Institut für Plasmaphysik, D-17491 Greifswald (Germany)

    2014-09-15

    The toroidal torque driven by external non-resonant magnetic perturbations (neoclassical toroidal viscosity) is an important momentum source affecting the toroidal plasma rotation in tokamaks. The well-known force-flux relation directly links this torque to the non-ambipolar neoclassical particle fluxes arising due to the violation of the toroidal symmetry of the magnetic field. Here, a quasilinear approach for the numerical computation of these fluxes is described, which reduces the dimension of a standard neoclassical transport problem by one without model simplifications of the linearized drift kinetic equation. The only limiting condition is that the non-axisymmetric perturbation field is small enough such that the effect of the perturbation field on particle motion within the flux surface is negligible. Therefore, in addition to most of the transport regimes described by the banana (bounce averaged) kinetic equation also such regimes as, e.g., ripple-plateau and resonant diffusion regimes are naturally included in this approach. Based on this approach, a quasilinear version of the code NEO-2 [W. Kernbichler et al., Plasma Fusion Res. 3, S1061 (2008).] has been developed and benchmarked against a few analytical and numerical models. Results from NEO-2 stay in good agreement with results from these models in their pertinent range of validity.

  17. Parametric interference effect in nonresonant pair photoproduction on a nucleus in the field of two pulsed light waves

    Science.gov (United States)

    Lebed', A. A.; Padusenko, E. A.; Roshchupkin, S. P.; Dubov, V. V.

    2017-04-01

    Nonresonant electron-positron pair photoproduction on a nucleus in the field of two pulsed light waves is studied theoretically. The process is considered in detail within the interference kinematic region, when stimulated absorption and emission of photons of external pulsed waves by an electron and a positron occurs in a correlated manner. Within this region, a correspondence between the emission angle and energy of the produced particles appears. The distribution of the obtained differential cross section over the pair kinetic energy is characterized by presence of oscillations, within the interference region. Each of the maxima corresponds to the definite partial process with emission and absorption of an equal number of photons of both waves. It was shown that the differential cross section within the interference region for certain values of the pair energy may exceed the cross section in other scattering kinematics in two orders of the magnitude. Obtained results may be experimentally verified, for example, by scientific facilities at sources of pulsed laser radiation (SLAC, FAIR, ELI, XCELS).

  18. Narrowband tunable VUV radiation generated by nonresonant sum- and difference-frequency mixing in xenon and krypton.

    Science.gov (United States)

    Hilbig, R; Wallenstein, R

    1982-03-01

    Nonresonant sum- and difference-frequency mixing of the fundamental omega(L) and the second harmonic omega(UV) radiation of a powerful narrowband pulsed dye laser system excited by an Nd:YAG laser (lambda(L) = 5500-6500 A) generates intense VUV radiation in krypton and xenon with the frequency omega(VUV) = 2omega(UV) micro omega(L). The sum-frequency is tunable in spectral regions of negative dispersion between 1100 and 1300 A. The maximum VUV pulse power exceeds 20 W (5 x 10(10) photons/pulse). VUV light pulses with up to 60 W (2.3 x 10(11) photons/pulse) are provided by the difference-frequency at wavelengths between 1850 and 2070 A. In addition the conversion process omega(VUV) = 2omega(UV) - omega(IR) (omega(IR) is the frequency of the Nd:YAG laser) generates radiation in the wavelength range of 1595-1866 A. With present laser systems the tuning range of the difference-frequency could be extended to wavelengths as short as 1226 A. The sum- and difference-frequency conversion will thus provide intense coherent VUV light continuously tunable between 1100 and 2100 A.

  19. Non-resonant secular dynamics of trans-Neptunian objects perturbed by a distant super-Earth

    Science.gov (United States)

    Saillenfest, Melaine; Fouchard, Marc; Tommei, Giacomo; Valsecchi, Giovanni B.

    2017-08-01

    We use a secular model to describe the non-resonant dynamics of trans-Neptunian objects in the presence of an external ten-Earth-mass perturber. The secular dynamics is analogous to an "eccentric Kozai mechanism" but with both an inner component (the four giant planets) and an outer one (the eccentric distant perturber). By the means of Poincaré sections, the cases of a non-inclined or inclined outer planet are successively studied, making the connection with previous works. In the inclined case, the problem is reduced to two degrees of freedom by assuming a non-precessing argument of perihelion for the perturbing body. The size of the perturbation is typically ruled by the semi-major axis of the small body: we show that the classic integrable picture is still valid below about 70 AU, but it is progressively destroyed when we get closer to the external perturber. In particular, for a>150 AU, large-amplitude orbital flips become possible, and for a>200 AU, the Kozai libration islands at ω =π /2 and 3π /2 are totally submerged by the chaotic sea. Numerous resonance relations are highlighted. The most large and persistent ones are associated with apsidal alignments or anti-alignments with the orbit of the distant perturber.

  20. Non-resonant microwave absorption studies of superconducting MgB2 and MgB2 + MgO

    Indian Academy of Sciences (India)

    Janhavi P Joshi; Subhasis Sarangi; A K Sood; Dilip Pal; S V Bhat

    2002-02-01

    Non-resonant microwave absorption (NRMA) studies of superconducting MgB2 and a sample containing ∼ 10% by weight of MgO in MgB2 are reported. The NRMA results indicate near absence of intergranular weak links in the pure MgB2 sample. A linear temperature dependence of the lower critical field c1 is observed indicating a non- wave superconductivity. However, the phase reversal of the NRMA signal which could suggest wave symmetry is also not observed. In the MgB2 + MgO sample, much larger low field dependent absorption is observed indicating the presence of intergranular weak links. The hysteretic behavior of NRMA is compared and contrasted in the two samples. In the pure MgB2 sample, a large hysteresis is observed between the forward and the reverse scans of the magnetic field indicating strong pinning of flux lines. This hysteresis saturates a few degrees below c while in the MgB2 + MgO sample, a much slower increase of hysteresis with decreasing temperature is observed, a signature of weaker pinning.