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Sample records for applications reflectance confocal

  1. Dual-wedge scanning confocal reflectance microscope.

    PubMed

    Warger, William C; DiMarzio, Charles A

    2007-08-01

    A confocal reflectance microscope has been developed that incorporates a dual-wedge scanner to reduce the size of the device relative to current raster scanning instruments. The scanner is implemented with two prisms that are rotated about the optical axis. Spiral and rosette scans are performed by rotating the prisms in the same or opposite directions, respectively. Experimental measurements show an on-axis lateral resolution of 1.6 microm and optical sectioning of 4.7 microm, which compares with a diffraction-limited resolution of 0.8 and 1.9 microm, respectively. PMID:17671563

  2. A handheld laser scanning confocal reflectance imaging–confocal Raman microspectroscopy system

    PubMed Central

    Patil, Chetan A.; Arrasmith, Christopher L.; Mackanos, Mark A.; Dickensheets, David L.; Mahadevan-Jansen, Anita

    2012-01-01

    Confocal reflectance microscopy and confocal Raman spectroscopy have shown potential for non-destructive analysis of samples at micron-scale resolutions. Current studies utilizing these techniques often employ large bench-top microscopes, and are not suited for use outside of laboratory settings. We have developed a microscope which combines laser scanning confocal reflectance imaging and confocal Raman spectroscopy into a compact handheld probe that is capable of high-resolution imaging and spectroscopy in a variety of settings. The compact size of the probe is largely due to the use of a MEMS mirror for beam scanning. The probe is capable of axial resolutions of up to 4 ?m for the confocal imaging channel and 10 ?m for the confocal Raman spectroscopy channel. Here, we report instrument design, characterize optical performance, and provide images and spectra from normal skin to demonstrate the instrument’s capabilities for clinical diagnostics. PMID:22435097

  3. Single-wavelength reflected confocal and multiphoton microscopy for tissue imaging

    E-print Network

    So, Peter T. C.

    Both reflected confocal and multiphoton microscopy can have clinical diagnostic applications. The successful combination of both modalities in tissue imaging enables unique image contrast to be achieved, especially if a ...

  4. A laser reflection confocal large-radius measurement

    NASA Astrophysics Data System (ADS)

    Zhang, Xin; Qiu, Lirong; Li, Zhigang; Zhao, Weiqian

    2015-12-01

    We propose a new laser reflection confocal large-radius measurement (RCLRM) method. By utilizing the precise correspondence relationship between the peak point of the confocal curve and the convergence point of the multi-reflected measuring beam, we identify the position of the test lens. With a distance interferometer, we obtain the position variation of the test lens with different reflection times. Therefore, a fast and precise large-radius measurement is achieved with a shorter measuring system. Additionally, the RCLRM significantly enhances the measurement accuracy by using conic fitting. The theoretical analyses and experiments indicate that the relative expanded uncertainty is better than 0.008% (k??=??2).

  5. Spectral confocal reflection microscopy using a white light source

    NASA Astrophysics Data System (ADS)

    Booth, M.; Juškaitis, R.; Wilson, T.

    2008-08-01

    We present a reflection confocal microscope incorporating a white light supercontinuum source and spectral detection. The microscope provides images resolved spatially in three-dimensions, in addition to spectral resolution covering the wavelength range 450-650nm. Images and reflection spectra of artificial and natural specimens are presented, showing features that are not normally revealed in conventional microscopes or confocal microscopes using discrete line lasers. The specimens include thin film structures on semiconductor chips, iridescent structures in Papilio blumei butterfly scales, nacre from abalone shells and opal gemstones. Quantitative size and refractive index measurements of transparent beads are derived from spectral interference bands.

  6. Reflectance confocal microscopy of red blood cells: simulation and experiment

    PubMed Central

    Zeidan, Adel; Yelin, Dvir

    2015-01-01

    Measuring the morphology of red blood cells is important for clinical diagnosis, providing valuable indications on a patient’s health. In this work, we have simulated the appearance of normal red blood cells under a reflectance confocal microscope and discovered unique relations between the morphological parameters and the resulting characteristic interference patterns of the cell. The simulation results showed good agreement with in vitro reflectance confocal images of red blood cells, acquired using spectrally encoded flow cytometry that imaged the cells in a linear flow without artificial staining. By matching the simulated patterns to confocal images of the cells, this method could be used for measuring cell morphology in three dimensions and for studying their physiology. PMID:26600999

  7. FOOD SURFACE TEXTURE MEASUREMENT USING REFLECTIVE CONFOCAL LASER SCANNING MICROSCOPY

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Confocal laser scanning microscopy (CLSM) was used in the reflection mode to characterize the surface texture (roughness) of sliced food surfaces. Sandpapers of grit size between 150 and 600 were used as the height reference to standardize the CLSM hardware settings. Sandpaper particle sizes were v...

  8. A Pulse Coupled Neural Network Segmentation Algorithm for Reflectance Confocal Images of Epithelial Tissue

    PubMed Central

    Malik, Bilal H.; Jabbour, Joey M.; Maitland, Kristen C.

    2015-01-01

    Automatic segmentation of nuclei in reflectance confocal microscopy images is critical for visualization and rapid quantification of nuclear-to-cytoplasmic ratio, a useful indicator of epithelial precancer. Reflectance confocal microscopy can provide three-dimensional imaging of epithelial tissue in vivo with sub-cellular resolution. Changes in nuclear density or nuclear-to-cytoplasmic ratio as a function of depth obtained from confocal images can be used to determine the presence or stage of epithelial cancers. However, low nuclear to background contrast, low resolution at greater imaging depths, and significant variation in reflectance signal of nuclei complicate segmentation required for quantification of nuclear-to-cytoplasmic ratio. Here, we present an automated segmentation method to segment nuclei in reflectance confocal images using a pulse coupled neural network algorithm, specifically a spiking cortical model, and an artificial neural network classifier. The segmentation algorithm was applied to an image model of nuclei with varying nuclear to background contrast. Greater than 90% of simulated nuclei were detected for contrast of 2.0 or greater. Confocal images of porcine and human oral mucosa were used to evaluate application to epithelial tissue. Segmentation accuracy was assessed using manual segmentation of nuclei as the gold standard. PMID:25816131

  9. Emulation and design of terahertz reflection-mode confocal scanning microscopy based on virtual pinhole

    NASA Astrophysics Data System (ADS)

    Yang, Yong-fa; Li, Qi

    2014-12-01

    In the practical application of terahertz reflection-mode confocal scanning microscopy, the size of detector pinhole is an important factor that determines the performance of spatial resolution characteristic of the microscopic system. However, the use of physical pinhole brings some inconvenience to the experiment and the adjustment error has a great influence on the experiment result. Through reasonably selecting the parameter of matrix detector virtual pinhole (VPH), it can efficiently approximate the physical pinhole. By using this approach, the difficulty of experimental calibration is reduced significantly. In this article, an imaging scheme of terahertz reflection-mode confocal scanning microscopy that is based on the matrix detector VPH is put forward. The influence of detector pinhole size on the axial resolution of confocal scanning microscopy is emulated and analyzed. Then, the parameter of VPH is emulated when the best axial imaging performance is reached.

  10. Confocal Endomicroscopy: Instrumentation and Medical Applications

    PubMed Central

    Jabbour, Joey M.; Saldua, Meagan A.; Bixler, Joel N.; Maitland, Kristen C.

    2013-01-01

    Advances in fiber optic technology and miniaturized optics and mechanics have propelled confocal endomicroscopy into the clinical realm. This high resolution, non-invasive imaging technology provides the ability to microscopically evaluate cellular and sub-cellular features in tissue in vivo by optical sectioning. Because many cancers originate in epithelial tissues accessible by endoscopes, confocal endomicroscopy has been explored to detect regions of possible neoplasia at an earlier stage by imaging morphological features in vivo that are significant in histopathologic evaluation. This technique allows real-time assessment of tissue which may improve diagnostic yield by guiding biopsy. Research and development continues to reduce the overall size of the imaging probe, increase the image acquisition speed, and improve resolution and field of view of confocal endomicroscopes. Technical advances will continue to enable application to less accessible organs and more complex systems in the body. Lateral and axial resolutions down to 0.5 ?m and 3 ?m, respectively, field of view as large as 800×450 ?m, and objective lens and total probe outer diameters down to 350 ?m and 1.25 mm, respectively, have been achieved. We provide a review of the historical developments of confocal imaging in vivo, the evolution of endomicroscope instrumentation, and the medical applications of confocal endomicroscopy. PMID:21994069

  11. Lens central thickness measurement by laser reflection-confocal technology

    NASA Astrophysics Data System (ADS)

    Qiu, Lirong; Guo, Yongkui; Zhao, Weiqian; Xiao, Yang

    2015-08-01

    A new laser reflection-confocal thickness measurement (LRCTM) method is proposed for the reference lens central thickness calibration of the combined focal-length. LRCTM uses the reflector to reflect the convergent beam that come from the test lens to precisely identify the vertexes of test lens first and last surface, then uses ray tracing facet iterative algorithm to obtain lens central thickness. The test lens is put in the parallel light which makes its coaxality easier to adjust, and the optical path can be shortened with the reflector reflecting the convergent beam. LRCTM has high precision and concise structure, and it is suitable to be applied in the engineering. Preliminary experiments and analysis indicate that the relative measurement accuracy can be better than 0.03%.

  12. Segmentation of skin strata in reflectance confocal microscopy depth stacks

    NASA Astrophysics Data System (ADS)

    Hames, Samuel C.; Ardigò, Marco; Soyer, H. Peter; Bradley, Andrew P.; Prow, Tarl W.

    2015-03-01

    Reflectance confocal microscopy is an emerging tool for imaging human skin, but currently requires expert human assessment. To overcome the need for human experts it is necessary to develop automated tools for automatically assessing reflectance confocal microscopy imagery. This work presents a novel approach to this task, using a bag of visual words approach to represent and classify en-face optical sections from four distinct strata of the skin. A dictionary of representative features is learned from whitened and normalised patches using hierarchical spherical k-means. Each image is then represented by extracting a dense array of patches and encoding each with the most similar element in the dictionary. Linear discriminant analysis is used as a simple linear classifier. The proposed framework was tested on 308 depth stacks from 54 volunteers. Parameters are tuned using 10 fold cross validation on a training sub-set of the data, and final evaluation was performed on a held out test set. The proposed method generated physically plausible profiles of the distinct strata of human skin, and correctly classified 81.4% of sections in the test set.

  13. Combined FLIM and reflectance confocal microscopy for epithelial imaging

    NASA Astrophysics Data System (ADS)

    Jabbour, Joey M.; Cheng, Shuna; Shrestha, Sebina; Malik, Bilal; Jo, Javier A.; Applegate, Brian; Maitland, Kristen C.

    2012-03-01

    Current methods for detection of oral cancer lack the ability to delineate between normal and precancerous tissue with adequate sensitivity and specificity. The usual diagnostic mechanism involves visual inspection and palpation followed by tissue biopsy and histopathology, a process both invasive and time-intensive. A more sensitive and objective screening method can greatly facilitate the overall process of detection of early cancer. To this end, we present a multimodal imaging system with fluorescence lifetime imaging (FLIM) for wide field of view guidance and reflectance confocal microscopy for sub-cellular resolution imaging of epithelial tissue. Moving from a 12 x 12 mm2 field of view with 157 ìm lateral resolution using FLIM to 275 x 200 ?m2 with lateral resolution of 2.2 ?m using confocal microscopy, hamster cheek pouch model is imaged both in vivo and ex vivo. The results indicate that our dual modality imaging system can identify and distinguish between different tissue features, and, therefore, can potentially serve as a guide in early oral cancer detection..

  14. The use of reflectance confocal microscopy for examination of benign and malignant skin tumors

    PubMed Central

    Wielowieyska-Szybi?ska, Dorota; Bia?ek-Galas, Kamila; Podolec, Katarzyna

    2014-01-01

    Reflectance confocal microscopy (RCM) is a modern, non-invasive diagnostic method that enables real-time imaging of epidermis and upper layers of the dermis with a nearly histological precision and high contrast. The application of this technology in skin imaging in the last few years has resulted in the progress of dermatological diagnosis, providing virtual access to the living skin erasing the need for conventional histopathology. The RCM has a potential of wide application in the dermatological diagnostic process with a particular reference to benign and malignant skin tumors. This article provides a summary of the latest reports and previous achievements in the field of RCM application in the diagnostic process of skin neoplasms. A range of dermatological indications and general characteristics of confocal images in various types of tumors are presented. PMID:25610353

  15. Enhanced reflectivity contrast in confocal solid immersion lens microscopy Khaled Karraia)

    E-print Network

    Ludwig-Maximilians-Universität, München

    Enhanced reflectivity contrast in confocal solid immersion lens microscopy Khaled Karraia focused spot is investigated using confocal solid immersion microscopy. We find that the spot's image shows aberrations when reflected off objects with optical indexes lower than that of the solid immersion

  16. Confocal reflectance mosaicing of basal cell carcinomas in Mohs surgical skin excisions

    E-print Network

    Sridhar, Srinivas

    Confocal reflectance mosaicing of basal cell carcinomas in Mohs surgical skin excisions Yogesh G. Confocal reflectance mosaicing may enable rapid detection of BCCs directly in surgical excisions magnification view in light microscopes, which is routinely used by Mohs surgeons to examine frozen histology

  17. Genital warts: comparing clinical findings to dermatoscopic aspects, in vivo reflectance confocal features and histopathologic exam*

    PubMed Central

    Veasey, John Verrinder; Framil, Valéria Maria de Souza; Nadal, Sidney Roberto; Marta, Alessandra Cristine; Lellis, Rute Facchini

    2014-01-01

    Genital warts can be diagnosed through physical examination and confirmed by histopathology. Noninvasive methods are useful for ruling out other diagnoses with no harm to the patient. In this study the clinical findings were compared to dermoscopy, reflectance confocal microscopy (RCM), and to histopathology findings, in order to determine possible patterns that can aid diagnosis of the lesion. It was possible to identify structural changes on reflectance confocal microscopy that are already known by dermoscopy, in addition to cellular changes previously seen only by histopathological examination. This study shows the use of reflectance confocal microscopy in cases of genital warts, providing important information that can be used in further studies. PMID:24626658

  18. Character research on 2.52 terahertz coaxial reflection-mode confocal scanning microscopic imaging

    NASA Astrophysics Data System (ADS)

    Yang, Yong-fa; Li, Qi; Hu, Jia-qi

    2014-12-01

    The technology of terahertz (THz) is a major research area in the 21st century. THz imaging is an important research direction. The single-frequency continuous-wave THz technology is combined with coaxial reflection-mode confocal scanning microscopic imaging in this article. Under the given system parameters, the transverse response character of 2.52THz (118.83?m) coaxial reflection-mode confocal scanning microscopic imaging is emulated and analyzed. The results of emulation show that coaxial reflection-mode confocal scanning microscopic imaging is feasible in THz region.

  19. Biological applications of confocal fluorescence polarization microscopy

    NASA Astrophysics Data System (ADS)

    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 serum albumin attached to sepharose beads. The action of trypsin and proteinase K on the albumin is monitored to demonstrate validity of the technique. Images of the processing of the albumin in J774 murine macrophages are also presented indicating large intercellular differences in enzyme activity. Future directions for the technique are also presented, including the design of enzyme probes specific for prostate specific antigen based on fluorescently-labeled dendrimers. A technique for enzyme imaging based on extracellular autofluorescence is also proposed.

  20. Monitoring treatment of field cancerisation with 3% diclofenac sodium 2.5% hyaluronic acid by reflectance confocal microscopy: a histologic correlation.

    PubMed

    Malvehy, Josep; Roldán-Marín, Rodrigo; Iglesias-García, Pablo; Díaz, Alba; Puig, Susana

    2015-01-01

    Visual inspection may fail to accurately evaluate field cancerisation (subclinical actinic keratoses [AKs]). We aimed to describe field cancerisation by confocal reflectance microscopy and changes induced by the application of 3% diclofenac sodium gel in 2.5% hyaluronic acid. Fourteen male patients, >?50 years old, with AKs on the bald scalp were included. Clinical examination, confocal microscopy and histological study of clinically visible lesions and "normal appearing" adjacent skin before and after treatment was completed. Reflectance confocal microscopy showed a decrease in scaling (p?=?0.001) and atypia of the honeycomb pattern (p?=?0.001) at 2 weeks of treatment. Changes in parakeratosis, inflammation and dermal collagen remodelling were also observed. Histology correlated with confocal features in AK and subclinical AK. Reflectance confocal microscopy was useful in the evaluation of field cancerisation and monitoring of treatment response. A rapid improvement in epidermal atypia was observed. PMID:24696069

  1. Visualization of the microtubules of glutaraldehyde-fixed cells by reflection-enhanced backscatter confocal microscopy.

    PubMed

    Keith, Charles H; Farmer, Mark A

    2006-04-01

    Performing reflection-mode (backscatter-mode) confocal microscopy on cells growing on reflective substrates gives images that have improved contrast and are more easily interpreted than standard reflection-mode confocal micrographs (Keith et al., 1998). However, a number of factors degrade the quality of images taken with the highest-resolution microscope objectives in this technique. We here describe modifications to reflection-enhanced backscatter confocal microscopy that (partially) overcome these factors. With these modifications of the technique, it is possible to visualize structures the size-and refractility-of individual microtubules in intact cells. Additionally, we demonstrate that this technique, in common with fluorescence techniques such as standing wave widefield fluorescence microscopy and 4-Pi confocal microscopy, offers improved resolution in the Z-direction. PMID:17481347

  2. Reflectance confocal endomicroscope with optical axial scanning for in vivo imaging of the oral mucosa.

    PubMed

    Jabbour, Joey M; Bentley, Julie L; Malik, Bilal H; Nemechek, John; Warda, John; Cuenca, Rodrigo; Cheng, Shuna; Jo, Javier A; Maitland, Kristen C

    2014-11-01

    This paper presents the design and evaluation of a reflectance confocal laser endomicroscope using a miniature objective lens within a rigid probe in conjunction with an electrically tunable lens for axial scanning. The miniature lens was characterized alone as well as in the endoscope across a 200 µm axial scan range using the tunable lens. The ability of the confocal endoscope to probe the human oral cavity is demonstrated by imaging of the oral mucosa in vivo. The results indicate that reflectance confocal endomicroscopy has the potential to be used in a clinical setting and guide diagnostic evaluation of biological tissue. PMID:25426310

  3. Single-wavelength reflected confocal and multiphoton microscopy for tissue imaging

    NASA Astrophysics Data System (ADS)

    Chen, Wei-Liang; Chou, Chen-Kuan; Lin, Ming-Gu; Chen, Yang-Fang; Jee, Shiou-Hwa; Tan, Hsin-Yuan; Tsai, Tsung-Hua; Kim, Ki-Hean; Kim, Daekeun; So, Peter T. C.; Lin, Sung-Jan; Dong, Chen-Yuan

    2009-09-01

    Both reflected confocal and multiphoton microscopy can have clinical diagnostic applications. The successful combination of both modalities in tissue imaging enables unique image contrast to be achieved, especially if a single laser excitation wavelength is used. We apply this approach for skin and corneal imaging using the 780-nm output of a femtosecond, titanium-sapphire laser. We find that the near-IR, reflected confocal (RC) signal is useful in characterizing refractive index varying boundaries in bovine cornea and porcine skin, while the multiphoton autofluorescence (MAF) and second-harmonic generation (SHG) intensities can be used to image cytoplasm and connective tissues (collagen), respectively. In addition, quantitative analysis shows that we are able to detect MAF from greater imaging depths than with the near-IR RC signal. Furthermore, by performing RC imaging at 488, 543, and 633 nm, we find that a longer wavelength leads to better image contrast for deeper imaging of the bovine cornea and porcine skin tissue. Finally, by varying power of the 780-nm source, we find that comparable RC image quality was achieved in the 2.7 to 10.7-mW range.

  4. Reflectance and Fluorescence Confocal Microscope for Imaging of the Mouse Colon 

    E-print Network

    Saldua, Meagan Alyssa

    2012-02-14

    AND FLUORESCENCE CONFOCAL MICROSCOPE FOR IMAGING OF THE MOUSE COLON A Thesis by MEAGAN ALYSSA SALDUA Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE... December 2010 Major Subject: Biomedical Engineering REFLECTANCE AND FLUORESCENCE CONFOCAL MICROSCOPE FOR IMAGING OF THE MOUSE COLON A Thesis by MEAGAN ALYSSA SALDUA Submitted to the Office of Graduate Studies of Texas A&M University...

  5. Clinical Reflectance Confocal Microscope for Imaging of Oral Cancer 

    E-print Network

    Jabbour, Joey

    2014-08-05

    . .............................................................................................................. 15 Figure 6: Schematic of the combined FLIM-RCM system. Left: The FLIM module uses a UV pulsed laser, two galvanometer scanning mirrors, and a 45 mm focal length triplet lens (OL1). Three emission bands centered at 390 nm ix for collagen... for data acquisition. Right: The RCM module uses a NIR laser, resonant and galvanometer scanning mirrors, and 1.0 NA OL (OL2). Spatial filters [lenses (L) and pinholes (PH)] are used in confocal illumination and detection, and signal is detected...

  6. Fluorescence lifetime imaging and reflectance confocal microscopy for multiscale imaging of oral precancer

    NASA Astrophysics Data System (ADS)

    Jabbour, Joey M.; Cheng, Shuna; Malik, Bilal H.; Cuenca, Rodrigo; Jo, Javier A.; Wright, John; Cheng, Yi-Shing Lisa; Maitland, Kristen C.

    2013-04-01

    Optical imaging techniques using a variety of contrast mechanisms are under evaluation for early detection of epithelial precancer; however, tradeoffs in field of view (FOV) and resolution may limit their application. Therefore, we present a multiscale multimodal optical imaging system combining macroscopic biochemical imaging of fluorescence lifetime imaging (FLIM) with subcellular morphologic imaging of reflectance confocal microscopy (RCM). The FLIM module images a 16×16 mm2 tissue area with 62.5 ?m lateral and 320 ps temporal resolution to guide cellular imaging of suspicious regions. Subsequently, coregistered RCM images are acquired at 7 Hz with 400 ?m diameter FOV, <1 ?m lateral and 3.5 ?m axial resolution. FLIM-RCM imaging was performed on a tissue phantom, normal porcine buccal mucosa, and a hamster cheek pouch model of oral carcinogenesis. While FLIM is sensitive to biochemical and macroscopic architectural changes in tissue, RCM provides images of cell nuclear morphology, all key indicators of precancer progression.

  7. Fluorescence lifetime imaging and reflectance confocal microscopy for multiscale imaging of oral precancer

    PubMed Central

    Jabbour, Joey M.; Cheng, Shuna; Malik, Bilal H.; Cuenca, Rodrigo; Jo, Javier A.; Wright, John; Cheng, Yi-Shing Lisa

    2013-01-01

    Abstract. Optical imaging techniques using a variety of contrast mechanisms are under evaluation for early detection of epithelial precancer; however, tradeoffs in field of view (FOV) and resolution may limit their application. Therefore, we present a multiscale multimodal optical imaging system combining macroscopic biochemical imaging of fluorescence lifetime imaging (FLIM) with subcellular morphologic imaging of reflectance confocal microscopy (RCM). The FLIM module images a 16×16??mm2 tissue area with 62.5 ?m lateral and 320 ps temporal resolution to guide cellular imaging of suspicious regions. Subsequently, coregistered RCM images are acquired at 7 Hz with 400 ?m diameter FOV, <1???m lateral and 3.5 ?m axial resolution. FLIM-RCM imaging was performed on a tissue phantom, normal porcine buccal mucosa, and a hamster cheek pouch model of oral carcinogenesis. While FLIM is sensitive to biochemical and macroscopic architectural changes in tissue, RCM provides images of cell nuclear morphology, all key indicators of precancer progression. PMID:23595826

  8. Consistency and distribution of reflectance confocal microscopy features for diagnosis of cutaneous T cell lymphoma

    NASA Astrophysics Data System (ADS)

    Lange-Asschenfeldt, Susanne; Babilli, Jasmin; Beyer, Marc; Ríus-Diaz, Francisca; González, Salvador; Stockfleth, Eggert; Ulrich, Martina

    2012-01-01

    Reflectance confocal microscopy (RCM) represents a noninvasive imaging technique that has previously been used for characterization of mycosis fungoides (MF) in a pilot study. We aimed to test the applicability of RCM for diagnosis and differential diagnosis of MF in a clinical study. A total of 39 test sites of 15 patients with a biopsy-proven diagnosis of either MF, parapsoriasis, Sézary syndrome, or lymphomatoid papulosis were analyzed for presence and absence of RCM features of MF. Cochran and Chi2 analysis were applied to test the concordance between investigators and the distribution of RCM features, respectively. For selected parameters, the Cochran analysis showed good concordance between investigators. Inter-observer reproducibility was highest for junctional atypical lymphocytes, architectural disarray, and spongiosis. Similarly, Chi2 analysis demonstrated that selected features were present at particularly high frequency in individual skin diseases, with values ranging from 73% to 100% of all examined cases.

  9. Anti-translational research: from the bedside back to the bench for reflectance confocal microscopy

    NASA Astrophysics Data System (ADS)

    Gareau, Daniel

    2014-03-01

    The reflectance confocal microscope has made translational progress in dermatology. 0.5 micrometer lateral resolution, 0.75mm field-of-view and excellent temporal resolution at ~15 frames/second serve the VivaScope well in the clinic, but it may be overlooked in basic research. This work reviews high spatiotemporal confocal microscopy and presents images acquired of various samples: zebra fish embryo where melanocytes with excellent contrast overly the spinal column, chicken embryo, where myocardium is seen moving at 15 frames/ second, calcium spikes in dendrites (fluorescence mode) just beyond the temporal resolution, and human skin where blood cells race through the artereovenous microvasculature. For an introduction to confocal microscopy, see: http://dangareau.net.s69818.gridserver.com/science/confocal-microscopy

  10. Case Report: melanoma and melanocytic nevus differentiation with reflectance confocal microscopy.

    PubMed Central

    ?udzik, Joanna; Witkowski, Alexander M; Pellacani, Giovanni

    2015-01-01

    Historically, melanoma has been typically diagnosed by naked-eye examination and confirmed with invasive biopsy. However, recently the use of reflectance confocal microscopy enables non-invasive bedside diagnosis of clinically equivocal lesions. We present a case in which reflectance confocal microscopy was used to evaluate two skin lesions in the same patient confirming the diagnosis of a melanoma and potentially avoiding invasive biopsy in the second benign melanocytic lesion.  Clinicians should be aware of the availability of new non-invasive technologies that can aid in early diagnosis of malignant skin tumors and potentially reduce the number of benign lesion excisions. PMID:26236471

  11. High speed 3D surface profile without axial scanning: dual-detection confocal reflectance microscopy

    NASA Astrophysics Data System (ADS)

    Lee, Dong-Ryoung; Kim, Young-Duk; Gweon, Dae-Gab; Yoo, Hongki

    2014-12-01

    We propose dual-detection confocal reflectance microscopy (DDCRM) for high-speed 3D surface profiling. In comparison with conventional confocal microscopy, DDCRM can realize surface profiling without axial scanning. DDCRM is composed of two point detectors, each with a pinhole of different size. The ratio of the axial response curves measured by the two detectors provides the relationship between the axial position of the sample and the ratio of the intensity signals. Furthermore, DDCRM has a normalizing effect which allows this method to accurately measure the height of samples with various reflectance characteristics.

  12. Rheology and Confocal Reflectance Microscopy as Probes of Mechanical Properties and Structure during Collagen and

    E-print Network

    Kaufman, Laura

    during Collagen and Collagen/Hyaluronan Self-Assembly Ya-li Yang and Laura J. Kaufman* Department-dimensional collagen and collagen/hyaluronan (HA) composites is studied by time sweep rheology and time lapse confocal reflectance microscopy (CRM). To investigate the complementary nature of these techniques, first collagen gel

  13. Characterization of hydrogel microstructure using laser tweezers particle tracking and confocal reflection imaging

    PubMed Central

    Kotlarchyk, M A; Botvinick, E L; Putnam, A J

    2010-01-01

    Hydrogels are commonly used as extracellular matrix mimetics for applications in tissue engineering and increasingly as cell culture platforms with which to study the influence of biophysical and biochemical cues on cell function in 3D. In recent years, a significant number of studies have focused on linking substrate mechanical properties to cell function using standard methodologies to characterize the bulk mechanical properties of the hydrogel substrates. However, current understanding of the correlations between the microstructural mechanical properties of hydrogels and cell function in 3D is poor, in part because of a lack of appropriate techniques. Here we have utilized a laser tracking system, based on passive optical microrheology instrumentation, to characterize the microstructure of viscoelastic fibrin clots. Trajectories and mean square displacements were observed as bioinert PEGylated (PEG: polyethylene glycol) microspheres (1, 2 or 4.7 ?m in diameter) diffused within confined pores created by the protein phase of fibrin hydrogels. Complementary confocal reflection imaging revealed microstructures comprised of a highly heterogeneous fibrin network with a wide range of pore sizes. As the protein concentration of fibrin gels was increased, our quantitative laser tracking measurements showed a corresponding decrease in particle mean square displacements with greater resolution and sensitivity than conventional imaging techniques. This platform-independent method will enable a more complete understanding of how changes in substrate mechanical properties simultaneously influence other microenvironmental parameters in 3D cultures. PMID:20877437

  14. Reflective confocal laser scanning microscopy and nonlinear microscopy of cross-linked rabbit cornea

    NASA Astrophysics Data System (ADS)

    Krueger, Alexander; Hovakimyan, Marina; Ramirez, Diego F.; Stachs, Oliver; Guthoff, Rudolf F.; Heisterkamp, Alexander

    2009-07-01

    Cross-linking of the cornea with application of Ribovlavin and UV-A light is an evolving clinical treatment of the eye disease keratoconus. Despite the positive clinical track record of corneal cross-linking, the complex wound healing process after the treatment is still under investigation. In this study an animal model was used to clarify the state of wound healing 5 weeks after treatment. Cross-linked rabbit corneae were imaged with reflective confocal laser scanning and nonlinear microscopy, namely second harmonic imaging microscopy (SHIM) and two-photon excited autofluorescence. First results show that the NAD(P) H-autofluorescence of the corneal keratocytes and their scattering signal still show a signature of the treatment five weeks after the cross-linking procedure. The SHIM signals show the structural morphology of the fibrous collagen sheets in the stroma of the cornea. SHIM detected in the forward direction differs substantially from backward SHIM, but no signature of treatment was found in both detection channels of the SHIM signal.

  15. Learning Reflectance Confocal Microscopy of Melanocytic Skin Lesions through Histopathologic Transversal Sections

    PubMed Central

    Braga, Juliana Casagrande Tavoloni; Macedo, Mariana Petaccia; Pinto, Clovis; Duprat, João; Begnami, Maria Dirlei; Pellacani, Giovanni; Rezze, Gisele Gargantini

    2013-01-01

    Histopathologic interpretation of dermoscopic and reflectance confocal microscopy (RCM) features of cutaneous melanoma was timidly carried out using perpendicular histologic sections, which does not mimic the same plane of the image achieved at both techniques (horizontal plane). The aim of this study was to describe the transverse histologic sections research technique and correlate main dermoscopic features characteristic of cutaneous melanoma (atypical network, irregular globules and pseudopods) with RCM and histopathology in perpendicular and transverse sections in order to offer a more precise interpretation of in vivo detectable features. Four melanomas and 2 nevi with different dermoscopic clues have been studied. Lesion areas that showed characteristic dermoscopic features were imaged by dermoscopy and confocal microscopy and directly correlated with histopathology in perpendicular and transverse sections. We presented the possibility to perform transverse sections as a new approach to understand RCM features. Atypical network showed different aspects in the 2 melanomas: in one case it was characterized by pleomorphic malignant melanocytes with tendency to form aggregates, whereas in the other elongated dendritic cells crowded around dermal papillae, some of them forming bridges that resembled the mitochondrial aspect at confocal and histopathology transversal sections. Pigment globules in melanomas and nevi differed for the presence of large atypical cells in the former, and pseudopods showed up as elongated nests protruded toward the periphery of the lesion. Transverse histologic research sections have a consistent dermoscopic and confocal correlate, and it may represent an help in confocal feature interpretation and an advance in improving melanoma diagnosis and knowledge of the biology of melanocytic lesions. PMID:24339910

  16. Topographic variations in normal skin, as viewed by in vivo reflectance confocal microscopy.

    PubMed

    Huzaira, M; Rius, F; Rajadhyaksha, M; Anderson, R R; González, S

    2001-06-01

    Near-infrared confocal microscopy is a new tool that provides skin images in vivo, with high resolution and contrast at a specific depth. Regional variations in live human skin viewed by confocal microscope have not been studied so far. In vivo reflectance confocal microscopy was performed in 10 adults (eight males, two females) of various skin phototypes. Six topographic sites were studied in each subject: forehead, cheek, inner and outer forearm surfaces, lower back and leg. Epidermal thickness at suprapapillary epidermal plates and rete pegs was measured during real-time imaging and the number and diameter of epidermal keratinocytes in each epidermal cell layer as well as the characteristics of dermal papillae were defined from the grabbed images. Stratum corneum appeared brighter in sun-exposed than in sun-protected areas and particularly pronounced in heavily pigmented individuals. The epidermal thickness at rete pegs, but not the suprapapillary epidermal plate, was greater in sun-exposed areas than in sun-protected sites except forearm flexor surface. The en face numerical density of granular keratinocytes is greater on the face as compared with all other sites, whereas the surface density of spinous keratinocytes is greater on sun-protected sites. Additionally, the number of basal keratinocytes per millimeter length of dermoepidermal junction is greater in sun exposed areas. Interestingly, the dermal papillae shape varies and their sizes increase in circumference from sun-exposed to sun-protected sites, as observed at a specific depth below the stratum corneum. In summary, our results demonstrate that near infra-red reflectance confocal microscopy is a feasible tool for microscopic analysis of skin morphometry in vivo. PMID:11407970

  17. Evaluation of dermal extracellular matrix and epidermal-dermal junction modifications using matrix-assisted laser desorption/ionization mass spectrometric imaging, in vivo reflectance confocal microscopy, echography, and histology: effect of age and peptide applications.

    PubMed

    Mondon, Philippe; Hillion, Mélanie; Peschard, Olivier; Andre, Nada; Marchand, Thibault; Doridot, Emmanuel; Feuilloley, Marc Gj; Pionneau, Cédric; Chardonnet, Solenne

    2015-06-01

    This study was conducted to establish a new methodology for evaluating elements of dermal extracellular matrix (ECM), of epidermal-dermal junction (EDJ), and effects of molecules which can modulate their synthesis. This methodology is based on matrix-assisted laser desorption/ionization mass spectrometric imaging (MALDI-MSI). In vivo reflectance confocal microscopy (in vivo RCM) and echography were also used. Using immunohistochemistry methods on explants, age-related modification data were obtained for selected dermal ECM and EDJ proteins (collagen I, collagen IV, collagen VII, collagen XVII, nidogen I, decorin/decorunt) and used as reference for MALDI-MSI studies. A methodology was developed with MALDI-MSI to map epidermis and dermis proteins. Then MALDI-MSI was used to study age modifications. In vivo RCM and high-frequency ultrasounds were used to evaluate ECM and EDJ undulation modifications caused by aging. Anti-aging molecule evaluations were performed with a blend of palmitoyl oligopeptide and palmitoyl tetrapeptide-7. Immunohistochemistry studies demonstrated that the selected proteins were found to be less abundant in aged group explants vs. young group except for decorin. MALDI-MSI studies correlated the results obtained for decorin. In vivo RCM measurements indicated a decrease of EDJ undulation depth with age and ECM modifications in the upper part of dermis. Echography demonstrated that the peptide blend reduced subepidermal low-echogenic band thickness and improved its density. In vivo RCM studies indicated that the peptides improved the ECM structure vs. placebo. This preliminary MALDI-MSI study raised some technical difficulties that were overcome. Further studies will be conducted to identify more proteins and to demonstrate the interest of this method for cosmetic evaluations. PMID:25817264

  18. The application of dermal papillary rings in dermatology by in vivo confocal laser scanning microscopy

    NASA Astrophysics Data System (ADS)

    Xiang, W. Z.; Xu, A. E.; Xu, J.; Bi, Z. G.; Shang, Y. B.; Ren, Q. S.

    2010-08-01

    Confocal laser scanning microscopy (CLSM) allows noninvasive visualization of human skin in vivo, without needing to fix or section the tissue. Melanocytes and pigmented keratinocytes at the level of the basal layer form bright dermal papillary rings which are readily amenable to identify in confocal images. Our purpose was to explore the role of dermal papillary rings in assessment of lesion location, the diagnosis, differential diagnosis of lesions and assessment of therapeutic efficacy by in vivo CLSM. Seventy-one patients were imaged with the VivaScope 1500 reflectance confocal microscope provided by Lucid, Inc. The results indicate that dermal papillary rings can assess the location of lesion; the application of dermal papillary rings can provide diagnostic support and differential diagnosis for vitiligo, nevus depigmentosus, tinea versicolor, halo nevus, common nevi, and assess the therapeutic efficacy of NBUVB phototherapy plus topical 0.1 percent tacrolimus ointment for vitiligo. In conclusion, our findings indicate that the dermal papillary rings play an important role in the assessment the location of lesion, diagnosis, differential diagnosis of lesions and assessment of therapeutic efficacy by in vivo CLSM. CLSM may be a promising tool for noninvasive examination in dermatology. However, larger studies are needed to expand the application of dermal papillary rings in dermatology.

  19. Virtual pinhole confocal microscope

    SciTech Connect

    George, J.S.; Rector, D.M.; Ranken, D.M.; Peterson, B.; Kesteron, J.

    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.

  20. Performance of full-pupil line-scanning reflectance confocal microscopy in human skin and oral mucosa in vivo

    PubMed Central

    Larson, Bjorg; Abeytunge, Sanjeewa; Rajadhyaksha, Milind

    2011-01-01

    Point-scanning reflectance confocal microscopes continue to be successfully translated for detection of skin cancer. Line-scanning, with the use of a single scanner and a linear-array detector, offers a potentially smaller, simpler and lower cost alternative approach, to accelerate widespread dissemination into the clinic. However, translation will require an understanding of imaging performance deep within scattering and aberrating human tissues. We report the results of an investigation of the performance of a full-pupil line-scanning reflectance confocal microscope in human skin and oral mucosa, in terms of resolution, optical sectioning, contrast, signal-to-noise ratio, imaging and the effect of speckle noise. PMID:21750780

  1. Application of a novel confocal imaging technique for early the detection of dental decay

    NASA Astrophysics Data System (ADS)

    Rousseau, Christel; Girkin, John M.; Vaidya, Shilpa; Hall, Andrew F.; Whitters, C. J.; Creanor, Steve L.

    2002-06-01

    In order to stop or prevent the progression of dental disease, early detection and quantification of decay are crucially important. Dental decay (caries) detection methods have traditionally involved clinical examination by eye, using probes and dental radiography, but up to 60% of lesions are missed. What the dentist requires is a cheap, reliable method of detection of early disease, ideally with information on the depth and rate of growth or healing. Conventional commercial scanning confocal microscopes are unsuitable for use on dental patients. We report on a fibre optic based confocal microscope designed for in vivo examination of caries lesions. The system utilizes a common fibre both as the source and to detect the reflected confocal signal. The initial system has been optimized using dielectric mirrors and the thickness of the stack has been measured with high precision. Dental samples have been examined and the system has been demonstrated to provide information on the depth and mineral loss of a lesion. Fibre optic microscopy (FOCM) demonstrates a practical route to developing an in vivo caries profiler. In this paper, the FOCM and its applications in caries detection are described and the potential of this scheme as a practical dental probe is discussed.

  2. Confocal reflectance theta line scanning microscope for imaging human skin in vivo.

    PubMed

    Dwyer, Peter J; DiMarzio, Charles A; Zavislan, James M; Fox, William J; Rajadhyaksha, Milind

    2006-04-01

    A confocal reflectance theta line scanning microscope demonstrates imaging of nuclear and cellular detail in human epidermis in vivo. Experimentally measured line-spread functions determine the instrumental optical section thickness to be 1.7 +/- 0.1 microm and the lateral resolution to be 1.0 +/- 0.1 microm. Within human dermis (through full-thickness epidermis), the measured section thickness is 9.2 +/- 1.7 microm and the lateral resolution is 1.7 +/- 0.1 microm. An illumination line is scanned directly in the pupil of the objective lens, and the backscattered descanned light is detected with a linear array, such that the theta line scanner consists of only seven optical components. PMID:16599219

  3. A comparison study of detecting gold nanorods in living cells with confocal reflectance microscopy and two-photon fluorescence microscopy.

    PubMed

    Zhou, Y; Wu, X; Wang, T; Ming, T; Wang, P N; Zhou, L W; Chen, J Y

    2010-02-01

    Two-photon fluorescence microscopy and confocal reflectance microscopy were compared to detect intracellular gold nanorods in rat basophilic leukaemia cells. The two-photon photoluminescence images of gold nanorods were acquired by an 800 nm fs laser with the power of milliwatts. The advantages of the obtained two-photon photoluminescence images are high spatial resolution and reduced background. However, a remarkable photothermal effect on cells was seen after 30 times continuous scanning of the femto-second laser, potentially affecting the subcellular localization pattern of the nanorods. In the case of confocal reflectance microscopy the images of gold nanorods can be obtained with the power of light source as low as microwatts, thus avoiding the photothermal effect, but the resolution of such images is reduced. We have noted that confocal reflectance images of cellular gold nanorods achieved with 50 microW 800 nm fs have a relatively poor resolution, whereas the 50 microW 488 nm CW laser can acquire reasonably satisfactory 3D reflectance images with improved resolution because of its shorter wavelength. Therefore, confocal reflectance microscopy may also be a suitable means to image intracellular gold nanorods with the advantage of reduced photothermal effect. PMID:20096050

  4. Time-lapse confocal reflection microscopy of collagen fibrillogenesis and extracellular matrix assembly in vitro.

    PubMed

    Brightman, A O; Rajwa, B P; Sturgis, J E; McCallister, M E; Robinson, J P; Voytik-Harbin, S L

    2000-09-01

    The development of the next generation of biomaterials for restoration of tissues and organs (i.e., tissue engineering) requires a better understanding of the extracellular matrix (ECM) and its interaction with cells. Extracellular matrix is a macromolecular assembly of natural biopolymers including collagens, glycosaminoglycans (GAGs), proteoglycans (PGs), and glycoproteins. Interestingly, several ECM components have the ability to form three-dimensional (3D), supramolecular matrices (scaffolds) in vitro by a process of self-directed polymerization, "self-assembly". It has been shown previously that 3D matrices with distinct architectural and biological properties can be formed from either purified type I collagen or a complex mixture of interstitial ECM components derived from intestinal submucosa. Unfortunately, many of the imaging and analysis techniques available to study these matrices either are unable to provide insight into 3D preparations or demand efforts that are often prohibitory to observations of living, dynamic systems. This is the first report on the use of reflection imaging at rapid time intervals combined with laser-scanning confocal microscopy for analysis of structural properties and kinetics of collagen and ECM assembly in 3D. We compared time-lapse confocal reflection microscopy (TL-CRM) with a well-established spectrophotometric method for determining the self-assembly properties of both purified type I collagen and soluble interstitial ECM. While both TL-CRM and spectrophotometric techniques provided insight into the kinetics of the polymerization process, only TL-CRM allowed qualitative and quantitative evaluation of the structural parameters (e.g., fibril diameter) and 3D organization (e.g., fibril density) of component fibrils over time. Matrices formed from the complex mixture of soluble interstitial ECM components showed an increased rate of assembly, decreased opacity, decreased fibril diameter, and increased fibril density compared to that of purified type I collagen. These results suggested that the PG/GAG components of soluble interstitial ECM were affecting the polymerization of the component collagens. Therefore, the effects of purified and complex mixtures of PG/GAG components on the assembly properties of type I collagen and interstitial ECM were evaluated. The data confirmed that the presence of PG/GAG components altered the kinetics and the 3D fibril morphology of assembled matrices. In summary, TL-CRM was demonstrated to be a new and useful technique for analysis of the 3D assembly properties of collagen and other natural biopolymers which requires no specimen fixation and/or staining. PMID:10861383

  5. Diffractive lenses for chromatic confocal imaging Sarah L. Dobson, Pang-chen Sun, and Yeshayahu Fainman

    E-print Network

    Fainman, Yeshaiahu

    are suitable for applications that rely on reflection-mode operation. Existing chromatic confocal microscopes for nonmechanical depth scanning in a confocal microscope. This chromatic confocal microscope, constructed with 40 microscope is consistent with that of the conventional confocal operation of the microscope. © 1997 Optical

  6. Nontranslational three-dimensional profilometry by chromatic confocal microscopy with

    E-print Network

    Fainman, Yeshaiahu

    A confocal microscope profilometer, which incorporates chromatic depth scanning with a diffractive optical greatly limited its application for commercial inspection. A confocal microscope works by geometrically. In practice, for a reflection-mode confocal micro- scope, a point source is imaged onto the sample surface

  7. In vivo assessment of the structure of skin microcirculation by reflectance confocal-laser-scanning microscopy

    NASA Astrophysics Data System (ADS)

    Sugata, Keiichi; Osanai, Osamu; Kawada, Hiromitsu

    2012-02-01

    One of the major roles of the skin microcirculation is to supply oxygen and nutrition to the surrounding tissue. Regardless of the close relationship between the microcirculation and the surrounding tissue, there are few non-invasive methods that can evaluate both the microcirculation and its surrounding tissue at the same site. We visualized microcapillary plexus structures in human skin using in vivo reflectance confocal-laser-scanning microscopy (CLSM), Vivascope 3000® (Lucid Inc., USA) and Image J software (National Institutes of Health, USA) for video image processing. CLSM is a non-invasive technique that can visualize the internal structure of the skin at the cellular level. In addition to internal morphological information such as the extracellular matrix, our method reveals capillary structures up to the depth of the subpapillary plexus at the same site without the need for additional optical systems. Video images at specific depths of the inner forearm skin were recorded. By creating frame-to-frame difference images from the video images using off-line video image processing, we obtained images that emphasize the brightness depending on changes of intensity coming from the movement of blood cells. Merging images from different depths of the skin elucidates the 3-dimensional fine line-structure of the microcirculation. Overall our results show the feasibility of a non-invasive, high-resolution imaging technique to characterize the skin microcirculation and the surrounding tissue.

  8. Feasibility of intraoperative imaging during Mohs surgery with reflectance confocal microscopy

    NASA Astrophysics Data System (ADS)

    Flores, Eileen S.; Cordova, Miguel; Kose, Kivanc; Phillips, William; Nehal, Kishwer; Rajadhyaksha, Milind

    2014-03-01

    Mohs surgery for the removal of non-melanoma skin cancers (NMSCs) is performed in stages, while being guided by the examination for residual tumor with frozen pathology. However, preparation of frozen pathology at each stage is timeconsuming and labor-intensive. Real-time intraoperative reflectance confocal microscopy (RCM) may enable rapid detection of residual tumor directly in surgical wounds on patients. We report initial feasibility on twenty-one patients, using 35% AlCl3 for nuclear contrast. Imaging was performed in quadrants in the wound, to simulate the Mohs surgeon's examination of pathology. Images and videos of the epidermal and dermal margins were found to be of clinically acceptable quality. Bright nuclear morphology was identified at the epidermal margin. The presence of residual BCC/SCC tumor and normal skin features could be detected in the peripheral and deep dermal margins. Nuclear morphology was detectable in residual BCC/SCC tumors. Intraoperative RCM imaging may enable detection of residual tumor, directly on Mohs patients, and may serve as an adjunct for frozen pathology. However, a stronger source of contrast will be necessary, and also a smaller device with an automated approach for imaging in the entire wound in a rapid and controlled manner for clinical utility.

  9. In vivo reflectance confocal microscopy detects pigmentary changes in melasma at a cellular level resolution.

    PubMed

    Kang, Hee Young; Bahadoran, Philippe; Suzuki, Itaru; Zugaj, Didier; Khemis, Abdallah; Passeron, Thierry; Andres, Philippe; Ortonne, Jean-Paul

    2010-08-01

    Melasma is a frequent pigmentary disorder caused by abnormal melanin deposits in the skin. In vivo reflectance confocal microscopy (RCM) is a repetitive imaging tool that provides real-time images of the skin at nearly histological resolution. As melanin is the strongest endogenous contrast in human skin, pigmentary disorders are the most suitable candidates for RCM examination but RCM features of melasma have never been reported. This study investigates the pilot use of RCM in melasma to provide a set of well-described morphological criteria with histological correlations. RCM images were acquired from melasma skin and compared to adjacent control skin in 26 patients. Skin biopsies were obtained from eight patients. In the epidermis, RCM showed in all patients a significant increase in hyperrefractile cobblestoning cells. These cells corresponded to hyperpigmented basal keratinocytes in histology. In six patients, dendritic cells corresponding to activated melanocytes were also found in the epidermis. In the dermis, RCM identified in nine patients plump bright cells corresponding to melanophages. Interestingly, for a given patient, the topographic distribution of melanophages in melasma lesions was very heterogeneous. RCM also showed a significant increase in solar elastosis and blood vessels in the dermis. RCM is a non-invasive technique that detects pigmentary changes in melasma at a cellular level resolution. Therefore, RCM provides an innovative way to classify melasma by pigment changes. PMID:20497220

  10. Automated Delineation of Dermal-Epidermal Junction In Reflectance Confocal Microscopy Image Stacks Of Human Skin

    PubMed Central

    Park, Brian

    2014-01-01

    Reflectance confocal microscopy (RCM) images skin non-invasively, with optical sectioning and nuclear-level resolution comparable to that of pathology. Based on assessment of the dermal-epidermal junction (DEJ) and morphologic features in its vicinity, skin cancer can be diagnosed in vivo with high sensitivity and specificity. However, the current visual, qualitative approach for reading images leads to subjective variability in diagnosis. We hypothesize that machine learning-based algorithms may enable a more quantitative, objective approach. Testing and validation was performed with two algorithms that can automatically delineate the DEJ in RCM stacks of normal human skin. The test set was composed of 15 fair and 15 dark skin stacks (30 subjects) with expert labellings. In dark skin, in which the contrast is high due to melanin, the algorithm produced an average error of 7.9±6.4?m. In fair skin, the algorithm delineated the DEJ as a transition zone, with average error of 8.3±5.8?m for the epidermis-to-transition zone boundary and 7.6±5.6?m for the transition zone-to-dermis. Our results suggest that automated algorithms may quantitatively guide the delineation of the DEJ, to assist in objective reading of RCM images. Further development of such algorithms may guide assessment of abnormal morphological features at the DEJ. PMID:25184959

  11. Intraoperative imaging during Mohs surgery with reflectance confocal microscopy: initial clinical experience

    NASA Astrophysics Data System (ADS)

    Flores, Eileen S.; Cordova, Miguel; Kose, Kivanc; Phillips, William; Rossi, Anthony; Nehal, Kishwer; Rajadhyaksha, Milind

    2015-06-01

    Mohs surgery for the removal of nonmelanoma skin cancers (NMSCs) is performed in stages, while being guided by the examination for residual tumor with frozen pathology. However, preparation of frozen pathology at each stage is time consuming and labor intensive. Real-time intraoperative reflectance confocal microscopy (RCM), combined with video mosaicking, may enable rapid detection of residual tumor directly in the surgical wounds on patients. We report our initial experience on 25 patients, using aluminum chloride for nuclear contrast. Imaging was performed in quadrants in the wound to simulate the Mohs surgeon's examination of pathology. Images and videos of the epidermal and dermal margins were found to be of clinically acceptable quality. Bright nuclear morphology was identified at the epidermal margin and detectable in residual NMSC tumors. The presence of residual tumor and normal skin features could be detected in the peripheral and deep dermal margins. Intraoperative RCM imaging may enable detection of residual tumor directly on patients during Mohs surgery, and may serve as an adjunct for frozen pathology. Ultimately, for routine clinical utility, a stronger tumor-to-dermis contrast may be necessary, and also a smaller microscope with an automated approach for imaging in the entire wound in a rapid and controlled manner.

  12. In vivo quantification of epidermis pigmentation and dermis papilla density with reflectance confocal microscopy: variations with age and skin phototype.

    PubMed

    Lagarrigue, Sophie Garrido; George, Jerome; Questel, Emmanuel; Lauze, Christophe; Meyer, Nicolas; Lagarde, Jean-Michel; Simon, Michel; Schmitt, Anne-Marie; Serre, Guy; Paul, Carle

    2012-04-01

    Reflectance confocal microscopy (RCM) may help to quantify variations of skin pigmentation induced by different stimuli such as UV radiation or therapeutic intervention. The objective of our work was to identify RCM parameters able to quantify in vivo dermis papilla density and epidermis pigmentation potentially applicable in clinical studies. The study included 111 healthy female volunteers with phototypes I-VI. Photo-exposed and photo-protected anatomical sites were imaged. The effect of age was also assessed. Four epidermis components were specifically investigated: stratum corneum, stratum spinosum, basal epidermal layer and dermo-epidermal junction. Laser power, diameter of corneocytes and upper spinous keratinocytes, brightness of upper spinous and interpapillary spinous keratinocytes, number of dermal papillae and papillary contrast were systematically assessed. Papillary contrast measured at the dermo-epidermal junction appeared to be a reliable marker of epidermis pigmentation and showed a strong correlation with skin pigmentation assessed clinically using the Fitzpatrick's classification. Brightness of upper spinous and interpapillary spinous keratinocytes was not influenced by the skin phototype. The number of dermal papillae was significantly lower in subjects with phototypes I-II as compared with darker skin subjects. A dramatic reduction in the number of dermal papillae was noticed with age, particularly in subjects with fair skin. The method presented here provides a new in vivo investigation tool for quantification of dermis papilla density and epidermal pigmentation. Papillary contrast measured at the dermo-epidermal junction may be selected as a marker of skin pigmentation for evaluation in clinical studies. PMID:22417304

  13. Clinical applications of in vivo fluorescence confocal laser scanning microscopy

    NASA Astrophysics Data System (ADS)

    Oh, Chilhwan; Park, Sangyong; Kim, Junhyung; Ha, Seunghan; Park, Gyuman; Lee, Gunwoo; Lee, Onseok; Chun, Byungseon; Gweon, Daegab

    2008-02-01

    Living skin for basic and clinical research can be evaluated by Confocal Laser Scanning Microscope (CLSM) non-invasively. CLSM imaging system can achieve skin image its native state either "in vivo" or "fresh biopsy (ex vivo)" without fixation, sectioning and staining that is necessary for routine histology. This study examines the potential fluorescent CLSM with a various exogenous fluorescent contrast agent, to provide with more resolution images in skin. In addition, in vivo fluorescent CLSM researchers will be extended a range of potential clinical application. The prototype of our CLSM system has been developed by Prof. Gweon's group. The operating parameters are composed of some units, such as illuminated wavelength 488 nm, argon illumination power up to 20mW on the skin, objective lens, 0.9NA oil immersion, axial resolution 1.0?m, field of view 200?m x 100?m (lateral resolution , 0.3?m). In human volunteer, fluorescein sodium was administrated topically and intradermally. Animal studies were done in GFP transgenic mouse, IRC mouse and pig skin. For imaging of animal skin, fluorescein sodium, acridine orange, and curcumine were used for fluorescein contrast agent. We also used the GFP transgenic mouse for fluorescein CLSM imaging. In intact skin, absorption of fluorescein sodium by individual corneocyte and hair. Intradermal administrated the fluorescein sodium, distinct outline of keratinocyte cell border could be seen. Curcumin is a yellow food dye that has similar fluorescent properties to fluorescein sodium. Acridin Orange can be highlight nuclei in viable keratinocyte. In vivo CLSM of transgenic GFP mouse enable on in vivo, high resolution view of GFP expressing skin tissue. GFP signals are brightest in corneocyte, kertinocyte, hair and eccrine gland. In intact skin, absorption of fluorescein sodium by individual corneocyte and hair. Intradermal administrated the fluorescein sodium, distinct outline of keratinocyte cell border could be seen. In papillary dermis, fluorescein distribution is more homogeneous. Curcumin is a yellow food dye that has similar fluorescent properties to fluorescein sodium. In vivo CLSM of transgenic GFP mouse enable on in vivo, high resolution view of GFP expressing skin tissue. GFP signals are brightest in corneocyte, kertinocyte, skin appendage and blood vessels. In conclusion, this study demonstrates the usefulness of CLSM as technique for imaging skin in vivo. In addition, CLSM is non-invasive, the same tissue site may be imaged over a period of time to monitor the various change such as wound healing, severity of skin diseases and effect of therapeutic management.

  14. Validation study of automated dermal/epidermal junction localization algorithm in reflectance confocal microscopy images of skin

    NASA Astrophysics Data System (ADS)

    Kurugol, Sila; Rajadhyaksha, Milind; Dy, Jennifer G.; Brooks, Dana H.

    2012-02-01

    Reflectance confocal microscopy (RCM) has seen increasing clinical application for noninvasive diagnosis of skin cancer. Identifying the location of the dermal-epidermal junction (DEJ) in the image stacks is key for effective clinical imaging. For example, one clinical imaging procedure acquires a dense stack of 0.5x0.5mm FOV images and then, after manual determination of DEJ depth, collects a 5x5mm mosaic at that depth for diagnosis. However, especially in lightly pigmented skin, RCM images have low contrast at the DEJ which makes repeatable, objective visual identification challenging. We have previously published proof of concept for an automated algorithm for DEJ detection in both highly- and lightly-pigmented skin types based on sequential feature segmentation and classification. In lightly-pigmented skin the change of skin texture with depth was detected by the algorithm and used to locate the DEJ. Here we report on further validation of our algorithm on a more extensive collection of 24 image stacks (15 fair skin, 9 dark skin). We compare algorithm performance against classification by three clinical experts. We also evaluate inter-expert consistency among the experts. The average correlation across experts was 0.81 for lightly pigmented skin, indicating the difficulty of the problem. The algorithm achieved epidermis/dermis misclassification rates smaller than 10% (based on 25x25 mm tiles) and average distance from the expert labeled boundaries of ~6.4 ?m for fair skin and ~5.3 ?m for dark skin, well within average cell size and less than 2x the instrument resolution in the optical axis.

  15. Detectability of contrast agents for video-rate confocal reflectance microscopy of skin and microcirculation in vivo

    NASA Astrophysics Data System (ADS)

    Rajadhyaksha, Milind M.; Gonzalez, Salvador

    2003-06-01

    The lack of structure-specific contrast limits the usefulness of confocal reflectance microscopy to morphologic investigations at the cellular- and nuclear-level in human and animal skin in vivo. Morphologic and functional imaging at specific organelle- and ultrastructure-levels will require contrast agents that may be used and detected in vivo. High-resolution confocal reflectance imaging is based on the detection of singly back-scattered photons, where contrast is provided by variations in the refractive indices of microstructures. We carried out a quantitative Mie back-scatter analysis and imaging experiments to understand signal detectability of reflectance contrast agents for visualizing human skin and animal microcirculation. When imaging at video-rate with illumination of 10 milliwatts at 1064 nm, we detect 100-104 photons/pixel from the epidermis to dermis, relative to a background of 100 photons; this provides a signal-to-noise ratio of 3-40 and signal-to-background of 1-100. Organelles of size (d) 0.1-1.0 ?m with refractive indices (n) of 1.34-1.45 (relative to n=1.34 for epidermis, n=1.38 for dermis) back-scatter 10-104 photons/pixel. Exogenous contrast agents such as liposomes (n=1.41, d=0.7 ?m) and polystyrene microspheres (d=0.2-1.0 ?m, n=1.57; 100-105 photons/pixel) are detectable and they strongly enhance the contrast of microcirculation in the dermis of Sprague-Dawley rats. Topically applied 5% acetic acid causes the intra-nuclear 30-100 nm-thin chromatin filaments to condense into 1-5 ?m-thick strands, increasing back-scattered signal from 100 to 104 photons/pixels, making the nuclei appear bright and easily detectable in basal cell cancers. Such analyses provide a basis for optimizing confocal microscope design for detectability of contrast agents in vivo.

  16. A simple method for overcoming some problems when observing thick reflective biological samples with a confocal scanning laser microscope.

    PubMed

    Rumio, C; Morini, M; Miani, A; Barajon, I; Castano, P

    1995-01-01

    A simple device is described, which allows the range of depth of scanning to be reduced when observing thick reflecting biological samples with a confocal scanning laser microscope (CSLM). Thick histological sections of human skin and rat brain stem were mounted between two coverslips ('sandwich' style) and the optical tomography was performed from both sides by turning the 'sandwich' upside-down. The samples were impregnated using standard Golgi-Cox, 'rapid Golgi' or other silver methods. The ability to turn the 'sandwich' upside-down is particularly useful when the reflective structure inspected is deep inside the section, i.e., near the lower surface of the specimen, or when it is opaque to the laser beam or excessively reflective. PMID:7897649

  17. Detection of living Sarcoptes scabiei larvae by reflectance mode confocal microscopy in the skin of a patient with crusted scabies

    NASA Astrophysics Data System (ADS)

    Levi, Assi; Mumcuoglu, Kosta Y.; Ingber, Arieh; Enk, Claes D.

    2012-06-01

    Scabies is an intensely pruritic disorder induced by a delayed type hypersensitivity reaction to infestation of the skin by the mite Sarcoptes scabiei. The diagnosis of scabies is established clinically and confirmed by identifying mites or eggs by microscopic examination of scrapings from the skin or by surface microscopy using a dermatoscope. Reflectance-mode confocal microscopy is a novel technique used for noninvasive imaging of skin structures and lesions at a resolution compatible to that of conventional histology. Recently, the technique was employed for the confirmation of the clinical diagnosis of scabies. We demonstrate the first ever documentation of a larva moving freely inside the skin of a patient infected with scabies.

  18. Evaluation through in vivo reflectance confocal microscopy of the cutaneous neurogenic inflammatory reaction induced by capsaicin in human subjects

    NASA Astrophysics Data System (ADS)

    C?runtu, Constantin; Boda, Daniel

    2012-08-01

    We perform an in vivo analysis of the effects of capsaicin on cutaneous microvascularization. A total of 29 healthy subjects are administered a solution of capsaicin (CAP group) or a vehicle solution (nonCAP group) on the dorsal side of the nondominant hand. The evaluation is performed using in vivo reflectance confocal microscopy (RCM). Ten minutes after administration, the area of the section, the perimeter, and the Feret's diameter of the capillaries in the dermal papillae become significantly larger in the CAP group as against the nonCAP group, and this difference is maintained until the conclusion of the experiment. In vivo RCM allows the investigation of cutaneous vascular reactions induced by capsaicin. As such, this method may constitute an useful technique both for research and clinical practice.

  19. Reflectance Confocal Microscopy Features of Focal Dermal Mucinosis Differ from Those Described for Basal Cell Carcinoma: Report of Two Cases.

    PubMed

    Fraga-Braghiroli, Naiara Abreu; Merati, Miesha; Rabinovitz, Harold; Swanson, David; Scope, Alon

    2015-01-01

    The purpose of this study was to describe the reflectance confocal microscopy (RCM) features of focal dermal mucinosis (FDM). The entity clinically and dermatoscopically mimics other diagnostic entities, most notably nonpigmented basal cell carcinoma. We describe two cases that highlight the dermatoscopic, RCM and histopathological attributes of FDM. RCM features such as dermal foci of dense collagen bundles oriented in the same direction, foci of haphazardly oriented thin collagen fibers separated by dark structureless areas and the absence of dark silhouettes and tumor islands are clues for FDM diagnosis. The FDM cases described here present consistent and particular RCM findings that appear to correlate well with the histopathological features of FDM. Therefore, RCM is a promising technology in diagnosing skin lesions and it use can avoid invasive procedures. PMID:26302951

  20. Dual-mode reflectance and fluorescence near-video-rate confocal microscope for architectural, morphological and molecular imaging of tissue.

    PubMed

    Carlson, Alicia L; Coghlan, Lezlee G; Gillenwater, Ann M; Richards-Kortum, Rebecca R

    2007-10-01

    We have developed a near-video-rate dual-mode reflectance and fluorescence confocal microscope for the purpose of imaging ex vivo human specimens and in vivo animal models. The dual-mode confocal microscope (DCM) has light sources at 488, 664 and 784 nm, a frame rate of 15 frames per second, a maximum field of view of 300 x 250 mum and a resolution limit of 0.31 mum laterally and 1.37 mum axially. The DCM can image tissue architecture and cellular morphology, as well as molecular properties of tissue, using reflective and fluorescent molecular-specific optical contrast agents. Images acquired with the DCM demonstrate that the system has the sub-cellular resolution needed to visualize the morphological and molecular changes associated with cancer progression and has the capability to image animal models of disease in vivo. In the hamster cheek pouch model of oral carcinogenesis, the DCM was used to image the epithelium and stroma of the cheek pouch; blood flow was visible and areas of dysplasia could be distinguished from normal epithelium using 6% acetic acid contrast. In human oral cavity tissue slices, DCM reflectance images showed an increase in the nuclear-to-cytoplasmic ratio and density of nuclei in neoplastic tissues as compared to normal tissue. After labelling tissue slices with fluorescent contrast agents targeting the epidermal growth factor receptor, an increase in epidermal growth factor receptor expression was detected in cancerous tissue as compared to normal tissue. The combination of reflectance and fluorescence imaging in a single system allowed imaging of two different parameters involved in neoplastic progression, providing information about both the morphological and molecular expression changes that occur with cancer progression. The dual-mode imaging capabilities of the DCM allow investigation of both morphological changes as well as molecular changes that occur in disease processes. Analyzing both factors simultaneously may be advantageous when trying to detect and diagnose disease. The DCM's high resolution and near-video-rate image acquisition and the growing inventory of molecular-specific contrast agents and disease-specific molecular markers holds significant promise for in vivo studies of disease processes such as carcinogenesis. PMID:17910693

  1. Optical biopsy of early gastroesophageal cancer by catheter-based reflectance-type laser-scanning confocal microscopy.

    PubMed

    Nakao, Madoka; Yoshida, Shigeto; Tanaka, Shinji; Takemura, Yoshito; Oka, Shiro; Yoshihara, Masaharu; Chayama, Kazuaki

    2008-01-01

    Magnified endoscopic observation of the gastrointestinal tract has become possible. However, such observation at the cellular level remains difficult. Laser-scanning confocal microscopy (LCM) is a novel, noninvasive optical imaging method that provides instant microscopic images of untreated tissue under endoscopy. We compare prototype catheter-based reflectance-type LCM images in vivo and histologic images of early gastroesophageal cancer to assess the usefulness of LCM in diagnosing such cancer. 20 sites in the esophagus and 40 sites in the stomach are examined by LCM under endoscopy prior to endoscopic or surgical resection. A prototype catheter LCM system, equipped with a semiconductor laser that oscillates at 685 nm and analyzes reflected light (Mauna Kea Technologies, Paris, France; Fujinon, Saitama, Japan) is used in vivo without fluorescent agent. In all normal esophageal mucosa and esophageal cancers, the nuclei are visualized. In nine of the ten normal esophageal mucosa, cell membranes are visualized, and in five of the ten esophageal cancers, cell membranes are visualized. In all normal gastric mucosa, nuclei and cell membranes are not visualized, but in ten of the 20 gastric cancers, nuclei are visualized. This novel method will aid in immediate diagnosis under endoscopy without the need for biopsy. PMID:19021423

  2. A novel technique using potassium permanganate and reflectance confocal microscopy to image biofilm extracellular polymeric matrix reveals non-eDNA networks in Pseudomonas aeruginosa biofilms.

    PubMed

    Swearingen, Matthew C; Mehta, Ajeet; Mehta, Amar; Nistico, Laura; Hill, Preston J; Falzarano, Anthony R; Wozniak, Daniel J; Hall-Stoodley, Luanne; Stoodley, Paul

    2016-02-01

    Biofilms are etiologically important in the development of chronic medical and dental infections. The biofilm extracellular polymeric substance (EPS) determines biofilm structure and allows bacteria in biofilms to adapt to changes in mechanical loads such as fluid shear. However, EPS components are difficult to visualize microscopically because of their low density and molecular complexity. Here, we tested potassium permanganate, KMnO4, for use as a non-specific EPS contrast-enhancing stain using confocal laser scanning microscopy in reflectance mode. We demonstrate that KMnO4 reacted with EPS components of various strains of Pseudomonas, Staphylococcus and Streptococcus, yielding brown MnO2 precipitate deposition on the EPS, which was quantifiable using data from the laser reflection detector. Furthermore, the MnO2 signal could be quantified in combination with fluorescent nucleic acid staining. COMSTAT image analysis indicated that KMnO4 staining increased the estimated biovolume over that determined by nucleic acid staining alone for all strains tested, and revealed non-eDNA EPS networks in Pseudomonas aeruginosa biofilm. In vitro and in vivo testing indicated that KMnO4 reacted with poly-N-acetylglucosamine and Pseudomonas Pel polysaccharide, but did not react strongly with DNA or alginate. KMnO4 staining may have application as a research tool and for diagnostic potential for biofilms in clinical samples. PMID:26536894

  3. Evaluation of the therapeutic results of actinic keratosis treated with topical 5% fluorouracil by reflectance confocal laser microscopy: preliminary study.

    PubMed

    Ishioka, Priscila; Maia, Marcus; Rodrigues, Sarita Bartholomei; Marta, Alessandra Cristina; Hirata, Sérgio Henrique

    2015-01-01

    Topical treatment for actinic keratosis with 5% fluorouracil has a recurrence rate of 54% in 12 months of follow-up. This study analyzed thirteen actinic keratoses on the upper limbs through confocal microscopy, at the time of clinical diagnosis and after 4 weeks of treatment with fluorouracil. After the treatment was established and evidence of clinical cure was achieved, in two of the nine actinic keratoses, confocal microscopy enabled visualization of focal areas of atypical honeycomb pattern in the epidermis indicating therapeutic failure. Preliminary data suggest the use of confocal microscopy as a tool for diagnosis and therapeutic control of actinic keratosis. PMID:26131881

  4. Wavelength swept spectrally encoded confocal microscopy for biological and clinical applications

    E-print Network

    Boudoux, Caroline

    2007-01-01

    Spectrally encoded confocal microscopy (SECM) is a technique that facilitates the incorporation of confocal microscopy into small, portable clinical instruments. This would allow in vivo evaluation of cellular and sub-cellular ...

  5. Reflective coatings for solar applications

    SciTech Connect

    Jorgensen, G.

    1993-05-01

    Many applications of solar energy require large mirrors to provide high levels of concentrated sunlight. The success of such conversion systems hinges on the optical durability and economic viability of the reflector materials. A major effort at the National Renewable Energy Laboratory (NREL) has been to improve the existing reflector materials technology and to identify candidates that retain optical performance and durability criteria and offer potential for reduced cost. To attain the goals, it is desirable to maintain and increase the involvement of industrial organizations in reflective materials R&D related to the conversion of solar resources to useful energy. Toward this end, NREL has recently initiated several collaborative efforts with industry to develop advanced reflector materials.

  6. Reflective coatings for solar applications

    SciTech Connect

    Jorgensen, G.

    1993-05-01

    Many applications of solar energy require large mirrors to provide high levels of concentrated sunlight. The success of such conversion systems hinges on the optical durability and economic viability of the reflector materials. A major effort at the National Renewable Energy Laboratory (NREL) has been to improve the existing reflector materials technology and to identify candidates that retain optical performance and durability criteria and offer potential for reduced cost. To attain the goals, it is desirable to maintain and increase the involvement of industrial organizations in reflective materials R D related to the conversion of solar resources to useful energy. Toward this end, NREL has recently initiated several collaborative efforts with industry to develop advanced reflector materials.

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

    PubMed Central

    Zehri, Aqib H.; Ramey, Wyatt; Georges, Joseph F.; Mooney, Michael A.; Martirosyan, Nikolay L.; Preul, Mark C.; Nakaji, Peter

    2014-01-01

    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. PMID:24872922

  8. Image restoration for confocal microscopy: improving the limits of deconvolution, with application to the visualization of the mammalian hearing organ.

    PubMed Central

    Boutet de Monvel, J; Le Calvez, S; Ulfendahl, M

    2001-01-01

    Deconvolution algorithms have proven very effective in conventional (wide-field) fluorescence microscopy. Their application to confocal microscopy is hampered, in biological experiments, by the presence of important levels of noise in the images and by the lack of a precise knowledge of the point spread function (PSF) of the system. We investigate the application of wavelet-based processing tools to deal with these problems, in particular wavelet denoising methods, which turn out to be very effective in application to three-dimensional confocal images. When used in combination with more classical deconvolution algorithms, these methods provide a robust and efficient restoration scheme allowing one to deal with difficult imaging conditions. To make our approach applicable in practical situations, we measured the PSF of a Biorad-MRC1024 confocal microscope under a large set of imaging conditions, including in situ acquisitions. As a specific biological application, we present several examples of restorations of three-dimensional confocal images acquired inside an intact preparation of the hearing organ. We also provide a quantitative assessment of the gain in quality achieved by wavelet-aided restorations over classical deconvolution schemes, based on a set of numerical experiments that we performed with test images. PMID:11325744

  9. Clinical confocal microscopy.

    PubMed

    Petroll, W M; Cavanagh, H D; Jester, J V

    1998-08-01

    Because it provides much higher magnification and better optical sectioning than a slit-lamp biomicroscope, confocal microscopy is ideally suited for clinical imaging of the cornea. One important clinical application of confocal microscopy has been the early detection and diagnosis of a number of infectious conditions, including infection with Acanthamoeba and microsporidium species, fungal keratitis, and contact lens-associated bacterial keratitis. Confocal microscopy has also been used for temporal evaluation of corneal wound healing following refractive surgery and penetrating keratoplasty. With the development of the new technique of quantitative confocal microscopy through-focusing, confocal microscopy can be used to measure epithelial, stromal, and corneal thickness accurately and reproducibly in human patients. Furthermore, conofocal microscopy through-focusing can be used to determine the initial photoablation depth, changes in epithelial, stromal, and corneal thickness, and subepithelial haze following photorefractive keratectomy. PMID:10387471

  10. 3D Imaging of Porous Media Using Laser Scanning Confocal Microscopy with Application to Microscale Transport Processes

    SciTech Connect

    Fredrich, J.T.

    1999-02-10

    We present advances in the application of laser scanning confocal microscopy (LSCM) to image, reconstruct, and characterize statistically the microgeometry of porous geologic and engineering materials. We discuss technical and practical aspects of this imaging technique, including both its advantages and limitations. Confocal imaging can be used to optically section a material, with sub-micron resolution possible in the lateral and axial planes. The resultant volumetric image data, consisting of fluorescence intensities for typically {approximately}50 million voxels in XYZ space, can be used to reconstruct the three-dimensional structure of the two-phase medium. We present several examples of this application, including studying pore geometry in sandstone, characterizing brittle failure processes in low-porosity rock deformed under triaxial loading conditions in the laboratory, and analyzing the microstructure of porous ceramic insulations. We then describe approaches to extract statistical microgeometric descriptions from volumetric image data, and present results derived from confocal volumetric data sets. Finally, we develop the use of confocal image data to automatically generate a three-dimensional mesh for numerical pore-scale flow simulations.

  11. The application of laser scanning confocal microscopy to the examination of hairs and textile fibers: an initial investigation.

    PubMed

    Kirkbride, K Paul; Tridico, Silvana R

    2010-02-25

    An initial investigation of the application of laser scanning confocal microscopy to the examination of hairs and fibers has been conducted. This technique allows the production of virtual transverse and longitudinal cross-sectional images of a wide range of hairs and fibers. Special mounting techniques are not required; specimens that have been mounted for conventional microscopy require no further treatment. Unlike physical cross-sectioning, in which it is difficult to produce multiple cross-sections from a single hair or fiber and the process is destructive, confocal microscopy allows the examiner to image the cross-section at any point in the field of view along the hair or fiber and it is non-destructive. Confocal microscopy is a fluorescence-based technique. The images described in this article were collected using only the autofluorescence exhibited by the specimen (i.e. fluorescence staining was not necessary). Colorless fibers generally and hairs required excitation at 405 nm in order to stimulate useful autofluorescence; longer wavelength excitation was suitable for dyed fibers. Although confocal microscopy was found to be generally applicable to the generation virtual transverse cross-sections from a wide range of hairs and fibers, on some occasions the autofluorescence signal was attenuated by heavy pigmentation or the presence of an opaque medulla in hairs, and by heavy delustering or the presence of air-filled voids in the case of fibers. In these situations only partial cross-sections were obtained. PMID:19942383

  12. Design, operation and applications of a visible-light confocal scanning Fourier transform Raman microscope for volumetric Raman spectrochemical imaging

    NASA Astrophysics Data System (ADS)

    Brenan, Colin John Herbert

    A new type of confocal Raman microscope called a Fourier transform confocal Raman microscope (FT-CRM) was designed, built and characterized with respect to its spatio-spectral imaging properties. Several different applications of the FT-CRM are presented that take advantage of its unique spectral and spatial imaging characteristics. The instrument combines focused illumination with spatially-filtered detection in a confocal optical configuration to collect photons scattered from a diffraction-limited volume in the sample (typically [<]5×10-18/ m3) and reject photons from outside that region. The molecular vibrational information encoded in the inelastic, or Raman, spectral component of light scattered from the confocal volume is measured with a visible light Fourier transform Raman spectrometer. By scanning the sample relative to the confocal volume, a volumetric Raman spectrochemical image of the sample can be constructed. Raman scattering is an inherently inefficient process; hence an optimal radius pinhole must be found that balances the FT-CRM optical throughput against the microscope spatial resolution and image contrast. Detailed experimental measurements mapped out the FT-CRM spatial response (axial and lateral), optical throughput and image signal-to-background and signal-to-noise ratios as a function of pinhole radius. Excellent agreement was found between these measurements and the predictions of a theoretical microscope model also developed as part of this thesis. Several applications of the FT-CRM included volumetric compositional imaging of three-dimensional chemically inhomogeneous materials such as cellulose and polyester fibers in water or two immiscible optically- similar liquids, water and trichloroehthylene, in a porous quartz sandstone matrix. The potential of the FT- CRM for non-invasive spectrochemical detection and imaging through a turbid tissue-like medium was demonstrated and a new spectral estimator, Fast Orthogonal Search, was evaluated to replace the discrete Fourier transform to improve the microscope performance.

  13. Confocal endoscopy

    NASA Astrophysics Data System (ADS)

    Karadaglic, Dejan; Juskaitis, Rimas; Wilson, Tony

    2003-07-01

    We describe a simple modification to a rigid endoscope so as to provide both high quality conventional endoscopic as well as and confocal endoscopic images of reasonably accessible regions of the body in real time. The systems are based around either host lenslet-array tandem scanning microscope together with laser illumination or a structured illumination approach together with a conventional incoherent illumination source. Images taken in fluorescence are presented using this combined conventional and confocal endoscope.

  14. Digital holographic confocal microscope

    NASA Astrophysics Data System (ADS)

    Goy, Alexandre S.; Psaltis, Demetri

    2013-02-01

    We demonstrate experimentally a scanning confocal microscopy technique based on digital holographic recording of the scanned spot. The data collected in this way contains all the information to produce three-dimensional images. Several methods to treat the data are presented, such as the dynamic placement of the pinhole. Examples of reflection and transmission images of epithelial cells and mouse brain tissue are shown. The computations can be performed in real time, the speed being limited only by the frame rate of the camera. This method enables a convenient implementation of confocal microscopy, especially in transmission as no de-scan device is required.

  15. CONFOCAL MICROSCOPY SYSTEM PERFORMANCE: FOUNDATIONS FOR QUANTIFYING CYTOMETRIC APPLICATIONS WITH SPECTROSCOPIC INSTRUMENTS

    EPA Science Inventory

    The confocal laser-scanning microscopy (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 the emitted signal. The accuracy of these measurements demands t...

  16. Modern confocal microscopy.

    PubMed

    Rajwa, Bartek

    2005-02-01

    This unit re-examines confocal microscopy from a current perspective. It outlines many of the most modern applications of confocal microscopy and the issues surrounding them. The expanding applications of confocal microscopy demand both minor and major modifications of the technology to enhance imaging capabilities for a growing variety of samples. Techniques of interest such as FRET, FLIP, FRAP, and IFRAP are described. The unit includes a discussion on multispectral imaging, potentially the most exciting innovation in the field of biological imaging. The other area that is beginning to have considerable impact on biology, medicine, and pharmacology comprises high-content screening (HCS) and high-throughput screening (HTS). This unit also introduces programmable array microscopes (PAMs), which are based upon a technique in which spatial modulators are placed in the imaging plane of a microscope and used to generate patterns of illumination and/or detection. PMID:18770814

  17. Scanning computed confocal imager

    DOEpatents

    George, John S. (Los Alamos, NM)

    2000-03-14

    There is provided a confocal imager comprising a light source emitting a light, with a light modulator in optical communication with the light source for varying the spatial and temporal pattern of the light. A beam splitter receives the scanned light and direct the scanned light onto a target and pass light reflected from the target to a video capturing device for receiving the reflected light and transferring a digital image of the reflected light to a computer for creating a virtual aperture and outputting the digital image. In a transmissive mode of operation the invention omits the beam splitter means and captures light passed through the target.

  18. Multispectral confocal microendoscope for in vivo and in situ imaging

    E-print Network

    Gmitro, Arthur F.

    -scan confocal microscope coupled to an imaging catheter that is designed to be minimally invasive and allow. Confocal microendoscopy can be performed in reflectance1,2 or fluorescence3­8 modes. However, most confocalMultispectral confocal microendoscope for in vivo and in situ imaging Houssine Makhlouf Arthur F

  19. Application of laser differential confocal technique in back vertex power measurement for phoropters

    NASA Astrophysics Data System (ADS)

    Li, Fei; Li, Lin; Ding, Xiang; Liu, Wenli

    2012-10-01

    A phoropter is one of the most popular ophthalmic instruments used in optometry and the back vertex power (BVP) is one of the most important parameters to evaluate the refraction characteristics of a phoropter. In this paper, a new laser differential confocal vertex-power measurement method which takes advantage of outstanding focusing ability of laser differential confocal (LDC) system is proposed for measuring the BVP of phoropters. A vertex power measurement system is built up. Experimental results are presented and some influence factor is analyzed. It is demonstrated that the method based on LDC technique has higher measurement precision and stronger environmental anti-interference capability compared to existing methods. Theoretical analysis and experimental results indicate that the measurement error of the method is about 0.02m-1.

  20. In vivo reflectance confocal microscopy characterization of field-directed 5-fluorouracil 0.5%/salicylic acid 10% in actinic keratosis.

    PubMed

    Ulrich, Martina; Alarcon, Ivette; Malvehy, Josep; Puig, Susana

    2015-01-01

    Actinic keratosis (AK), a frequently diagnosed cutaneous neoplasm in individuals with chronic sun exposure or fair skin, is a risk factor for squamous cell carcinoma. AK presents as clinically visible lesions and/or as subclinical lesions where an entire field of area (field cancerization) contains lesions of various grades. The diagnosis and surveillance of subclinical AK is challenging. We report a new AK management approach, including subclinical AK, with noninvasive in vivo reflectance confocal microscopy (RCM) monitoring of field-directed topical 5-fluorouracil 0.5%/salicylic acid 10.0% (5-FU/SA; currently approved for single lesions). In this case series, eight patients with primarily recurrent, multiple AKs received ? 6 weeks of field-directed 5-FU/SA; complete clearance of clinical/subclinical AKs on various body areas was shown in most patients using RCM. RCM facilitated the detection/characterization of subclinical AKs in the setting of field cancerization. Topical field-directed 5-FU/SA monitored with RCM is a promising management approach for subclinical AKs. PMID:25721522

  1. Combined confocal Raman and quantitative phase microscopy system for biomedical diagnosis

    E-print Network

    Kang, Jeon Woong

    We have developed a novel multimodal microscopy system that incorporates confocal Raman, confocal reflectance, and quantitative phase microscopy (QPM) into a single imaging entity. Confocal Raman microscopy provides detailed ...

  2. Confocal Laser Scanning Microscope"LSM710" "LSM710"

    E-print Network

    Park, Byungwoo

    Confocal Laser Scanning Microscope"LSM710" "LSM710" National Center for Inter separation and ultimate stability Principle : Confocal Laser Scanning Microscope that is reflected/emitted from others than the focal plane. The laser scanning microscope scans the sample

  3. FluoRender: An Application of 2D Image Space Methods for 3D and 4D Confocal Microscopy Data Visualization in Neurobiology Research

    PubMed Central

    Wan, Yong; Otsuna, Hideo; Chien, Chi-Bin; Hansen, Charles

    2013-01-01

    2D image space methods are processing methods applied after the volumetric data are projected and rendered into the 2D image space, such as 2D filtering, tone mapping and compositing. In the application domain of volume visualization, most 2D image space methods can be carried out more efficiently than their 3D counterparts. Most importantly, 2D image space methods can be used to enhance volume visualization quality when applied together with volume rendering methods. In this paper, we present and discuss the applications of a series of 2D image space methods as enhancements to confocal microscopy visualizations, including 2D tone mapping, 2D compositing, and 2D color mapping. These methods are easily integrated with our existing confocal visualization tool, FluoRender, and the outcome is a full-featured visualization system that meets neurobiologists’ demands for qualitative analysis of confocal microscopy data. PMID:23584131

  4. Towards real-time image deconvolution: application to confocal and STED microscopy

    PubMed Central

    Zanella, R.; Zanghirati, G.; Cavicchioli, R.; Zanni, L.; Boccacci, P.; Bertero, M.; Vicidomini, G.

    2013-01-01

    Although deconvolution can improve the quality of any type of microscope, the high computational time required has so far limited its massive spreading. Here we demonstrate the ability of the scaled-gradient-projection (SGP) method to provide accelerated versions of the most used algorithms in microscopy. To achieve further increases in efficiency, we also consider implementations on graphic processing units (GPUs). We test the proposed algorithms both on synthetic and real data of confocal and STED microscopy. Combining the SGP method with the GPU implementation we achieve a speed-up factor from about a factor 25 to 690 (with respect the conventional algorithm). The excellent results obtained on STED microscopy images demonstrate the synergy between super-resolution techniques and image-deconvolution. Further, the real-time processing allows conserving one of the most important property of STED microscopy, i.e the ability to provide fast sub-diffraction resolution recordings. PMID:23982127

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

    SciTech Connect

    Shur, V. Ya. Zelenovskiy, P. S.

    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.

  6. Application of Laser Scanning Confocal Microscopy to Heat and Mass Transport Modeling in Porous Microstructures

    NASA Technical Reports Server (NTRS)

    Marshall, Jochen; Milos, Frank; Fredrich, Joanne; Rasky, Daniel J. (Technical Monitor)

    1997-01-01

    Laser Scanning Confocal Microscopy (LSCM) has been used to obtain digital images of the complicated 3-D (three-dimensional) microstructures of rigid, fibrous thermal protection system (TPS) materials. These orthotropic materials are comprised of refractory ceramic fibers with diameters in the range of 1 to 10 microns and have open porosities of 0.8 or more. Algorithms are being constructed to extract quantitative microstructural information from the digital data so that it may be applied to specific heat and mass transport modeling efforts; such information includes, for example, the solid and pore volume fractions, the internal surface area per volume, fiber diameter distributions, and fiber orientation distributions. This type of information is difficult to obtain in general, yet it is directly relevant to many computational efforts which seek to model macroscopic thermophysical phenomena in terms of microscopic mechanisms or interactions. Two such computational efforts for fibrous TPS materials are: i) the calculation of radiative transport properties; ii) the modeling of gas permeabilities.

  7. Imaging and profiling surface microstructures with noninterferometric confocal laser feedback

    E-print Network

    of confocal laser feedback is ex- plained in Fig. 1. The output of a laser diode is focused by a microscope to interferometry, which requires accurate alignment of the direction of the reflected beam, the confocal laserImaging and profiling surface microstructures with noninterferometric confocal laser feedback Chun

  8. Full-field interferometric confocal microscopy using a VCSEL array

    E-print Network

    Cao, Hui

    an interferometric confocal microscope using an array of 1200 vertical cavity surface emitting lasers (VCSELs sectioning as a scanning confocal microscope without moving parts, while the high power of the VCSEL array (5 for fluorescence imaging, it has the potential for high-speed, large-area reflectance imaging with confocal

  9. Simultaneous mechanical-scan-free confocal microscopy and laser microsurgery

    E-print Network

    Jalali. Bahram

    a confocal microscope as the aperture of the fiber that captures the reflection from the sample rejectsSimultaneous mechanical-scan-free confocal microscopy and laser microsurgery Kevin K. Tsia, Keisuke We demonstrate an endoscope-compatible single-fiber-based device that performs simultaneous confocal

  10. Near-surface seismic reflection applications

    E-print Network

    Steeples, Don W.

    2004-01-01

    of digital engineering seismographs designed for shallow, high-resolution surveys spurred significant improvements in engineering, mining, and environmental reflection seismology. Commonly, the reflection method is used in conjunction with other geophysical...

  11. Identifying brain neoplasms using dye-enhanced multimodal confocal imaging

    NASA Astrophysics Data System (ADS)

    Wirth, Dennis; Snuderl, Matija; Sheth, Sameer; Kwon, Churl-Su; Frosch, Matthew P.; Curry, William; Yaroslavsky, Anna N.

    2012-02-01

    Brain tumors cause significant morbidity and mortality even when benign. Completeness of resection of brain tumors improves quality of life and survival; however, that is often difficult to accomplish. The goal of this study was to evaluate the feasibility of using multimodal confocal imaging for intraoperative detection of brain neoplasms. We have imaged different types of benign and malignant, primary and metastatic brain tumors. We correlated optical images with histopathology and evaluated the possibility of interpreting confocal images in a manner similar to pathology. Surgical specimens were briefly stained in 0.05 mg/ml aqueous solution of methylene blue (MB) and imaged using a multimodal confocal microscope. Reflectance and fluorescence signals of MB were excited at 642 nm. Fluorescence emission of MB was registered between 670 and 710 nm. After imaging, tissues were processed for hematoxylin and eosin (H&E) histopathology. The results of comparison demonstrate good correlation between fluorescence images and histopathology. Reflectance images provide information about morphology and vascularity of the specimens, complementary to that provided by fluorescence images. Multimodal confocal imaging has the potential to aid in the intraoperative detection of microscopic deposits of brain neoplasms. The application of this technique may improve completeness of resection and increase patient survival.

  12. Identifying brain neoplasms using dye-enhanced multimodal confocal imaging.

    PubMed

    Wirth, Dennis; Snuderl, Matija; Sheth, Sameer; Kwon, Churl-Su; Frosch, Matthew P; Curry, William; Yaroslavsky, Anna N

    2012-02-01

    Brain tumors cause significant morbidity and mortality even when benign. Completeness of resection of brain tumors improves quality of life and survival; however, that is often difficult to accomplish. The goal of this study was to evaluate the feasibility of using multimodal confocal imaging for intraoperative detection of brain neoplasms. We have imaged different types of benign and malignant, primary and metastatic brain tumors. We correlated optical images with histopathology and evaluated the possibility of interpreting confocal images in a manner similar to pathology. Surgical specimens were briefly stained in 0.05 mg/ml aqueous solution of methylene blue (MB) and imaged using a multimodal confocal microscope. Reflectance and fluorescence signals of MB were excited at 642 nm. Fluorescence emission of MB was registered between 670 and 710 nm. After imaging, tissues were processed for hematoxylin and eosin (H&E) histopathology. The results of comparison demonstrate good correlation between fluorescence images and histopathology. Reflectance images provide information about morphology and vascularity of the specimens, complementary to that provided by fluorescence images. Multimodal confocal imaging has the potential to aid in the intraoperative detection of microscopic deposits of brain neoplasms. The application of this technique may improve completeness of resection and increase patient survival. PMID:22463044

  13. The Oberon2 Reflection Model and its Applications

    E-print Network

    Mössenböck, Hanspeter

    The Oberon­2 Reflection Model and its Applications Hanspeter Mössenböck, Christoph Steindl Johannes {moessenboeck,steindl}@ssw.uni­linz.ac.at Abstract. We describe the reflection model of Oberon­2, a language­2 reflection model is that metainformation is not obtained via metaclasses. It is rather organized

  14. Leica Confocal Software LCS

    E-print Network

    Yavuz, Deniz

    Leica Confocal Software LCS User manual (for Leica TCS SP2 systems) #12;Version: RK09052000 Page 2......................................................................................2 2 The Leica Confocal Software: An overview...............................................7 2.1 Starting the software..........................................................................7 2

  15. Confocal Microscopy Core Facility

    Cancer.gov

    The Confocal Microscopy Core Facility is supported by CCR and there is no charge to individual users for confocal time. Collaborations with laboratories outside the CCR are also considered, time permitting. Please refer to our publications list for exampl

  16. Confocal Microscopy Core Facility

    Cancer.gov

    The Confocal Microscopy Core Facility provides "open access" confocal laser scanning microscopy (LSM) services to all CCR investigators. The Facility's equipment includes a: Zeiss LSM 510 META NLO for 2-photon imaging system Zeiss LSM 710 NLO for 2-photon

  17. Diffuse reflectance imaging with astronomical applications

    E-print Network

    Hasinoff, Samuel W.

    Diffuse objects generally tell us little about the surrounding lighting, since the radiance they reflect blurs together incident lighting from many directions. In this paper we discuss how occlusion geometry can help invert ...

  18. Histopathological confirmation of similar intramucosal distribution of fluorescein in both intravenous administration and local mucosal application for probe-based confocal laser endomicroscopy of the normal stomach.

    PubMed

    Nonaka, Kouichi; Ohata, Ken; Ban, Shinichi; Ichihara, Shin; Takasugi, Rumi; Minato, Yohei; Tashima, Tomoaki; Matsuyama, Yasushi; Takita, Maiko; Matsuhashi, Nobuyuki; Neumann, Helmut

    2015-12-16

    Probe-based confocal laser endomicroscopy (pCLE) is capable of acquiring in vivo magnified cross-section images of the gastric mucosa. Intravenous injection of fluorescein sodium is used for confocal imaging. However, it is still under debate if local administration of the dye to the mucosa is also effective for confocal imaging as it is not yet clear if topical application also reveals the intramucosal distribution of fluorescein. The objective of this study was to evaluate the intramucosal distribution of fluorescein sodium after topical application and to compare the distribution to the conventional intravenous injection used for confocal imaging. pCLE of the stomach uninfected with Helicobacter pylori was performed in a healthy male employing intravenous administration and local mucosal application of fluorescein. The mucosa of the lower gastric body was biopsied 1 min and 5 min after intravenous administration or local mucosal application of fluorescein, and the distribution of fluorescein in the biopsy samples was examined histologically. Green fluorescence was already observed in the cytoplasm of fundic glandular cells in the biopsied deep mucosa 1 min after local mucosal application of fluorescein. It was also observed in the foveolar lumen and inter-foveolar lamina propria, although it was noted at only a few sites. In the tissue biopsied 5 min after the local mucosal application of fluorescein, green fluorescence was more frequently noted in the cytoplasm of fundic glandular cells than in that 1 min after the local mucosal application of fluorescein, although obvious green fluorescence was not identified in the foveolar lumen or inter-foveolar lamina propria. The distribution of intravenously administered fluorescein in the cytoplasm of fundic glandular cells was also clearly observed similarly to that after local mucosal application of fluorescein. Green fluorescence in more cells was observed in many cells 5 min after intravenous administration compared with that after 1 min. The presence of fluorescein in the mucosa was observed within a short time after local mucosal application of fluorescein, suggesting that pCLE images similarly to those after intravenous fluorescein administration can be acquired by local mucosal application of fluorescein. PMID:26677449

  19. Histopathological confirmation of similar intramucosal distribution of fluorescein in both intravenous administration and local mucosal application for probe-based confocal laser endomicroscopy of the normal stomach

    PubMed Central

    Nonaka, Kouichi; Ohata, Ken; Ban, Shinichi; Ichihara, Shin; Takasugi, Rumi; Minato, Yohei; Tashima, Tomoaki; Matsuyama, Yasushi; Takita, Maiko; Matsuhashi, Nobuyuki; Neumann, Helmut

    2015-01-01

    Probe-based confocal laser endomicroscopy (pCLE) is capable of acquiring in vivo magnified cross-section images of the gastric mucosa. Intravenous injection of fluorescein sodium is used for confocal imaging. However, it is still under debate if local administration of the dye to the mucosa is also effective for confocal imaging as it is not yet clear if topical application also reveals the intramucosal distribution of fluorescein. The objective of this study was to evaluate the intramucosal distribution of fluorescein sodium after topical application and to compare the distribution to the conventional intravenous injection used for confocal imaging. pCLE of the stomach uninfected with Helicobacter pylori was performed in a healthy male employing intravenous administration and local mucosal application of fluorescein. The mucosa of the lower gastric body was biopsied 1 min and 5 min after intravenous administration or local mucosal application of fluorescein, and the distribution of fluorescein in the biopsy samples was examined histologically. Green fluorescence was already observed in the cytoplasm of fundic glandular cells in the biopsied deep mucosa 1 min after local mucosal application of fluorescein. It was also observed in the foveolar lumen and inter-foveolar lamina propria, although it was noted at only a few sites. In the tissue biopsied 5 min after the local mucosal application of fluorescein, green fluorescence was more frequently noted in the cytoplasm of fundic glandular cells than in that 1 min after the local mucosal application of fluorescein, although obvious green fluorescence was not identified in the foveolar lumen or inter-foveolar lamina propria. The distribution of intravenously administered fluorescein in the cytoplasm of fundic glandular cells was also clearly observed similarly to that after local mucosal application of fluorescein. Green fluorescence in more cells was observed in many cells 5 min after intravenous administration compared with that after 1 min. The presence of fluorescein in the mucosa was observed within a short time after local mucosal application of fluorescein, suggesting that pCLE images similarly to those after intravenous fluorescein administration can be acquired by local mucosal application of fluorescein. PMID:26677449

  20. EVALUATION OF CONFOCAL MICROSCOPY SYSTEM PERFORMANCE: APPLICATIONS FOR IMAGING MORPHOLOGY AND DEATH IN EMBRYOS AND REPRODUCTIVE TISSUE/ORGANS

    EPA Science Inventory

    The confocal laser-scanning microscope (CLSM) has enormous potential in many biological fields. It is remarkable that procedures to test the performance of these machines are not done routinely by most investigators and thus many of the machines in the field are working at level...

  1. Binary phase digital reflection holograms - Fabrication and potential applications

    NASA Technical Reports Server (NTRS)

    Gallagher, N. C., Jr.; Angus, J. C.; Coffield, F. E.; Edwards, R. V.; Mann, J. A., Jr.

    1977-01-01

    A novel technique for the fabrication of binary-phase computer-generated reflection holograms is described. By use of integrated circuit technology, the holographic pattern is etched into a silicon wafer and then aluminum coated to make a reflection hologram. Because these holograms reflect virtually all the incident radiation, they may find application in machining with high-power lasers. A number of possible modifications of the hologram fabrication procedure are discussed.

  2. Liquid level sensing based on laser differential confocal detectors

    NASA Astrophysics Data System (ADS)

    Gao, Haibo; Fan, Chunshi; Zhang, Li; Hu, Yao

    2015-01-01

    Liquid level measurement plays an important part in industry and daily life. Applications include oil tanks, gasoline stations and public water supplies. Traditional electronic sensors cannot satisfy the demands in harsh environments. Recently, optical sensors have been particularly attractive in these applications. We propose a sensing method based on laser differential confocal detectors for discrete or continuous liquid level sensing. No target or supplementary device need to be immersed into the liquid. The sensitivity of the liquid level is about 0.01 mm with current systematic parameters. Measurement experiment of simulated liquid surface with a reflective mirror is carried out to verify the method.

  3. Confocal microscope with enhanced lateral resolution using engineered illumination pupil

    NASA Astrophysics Data System (ADS)

    Boruah, B. R.

    2010-02-01

    The maximum lateral resolution achievable with a confocal microscope is twice that of a wide field microscope. However, the spatial frequency content in the confocal image near the cutoff has very poor signal and is hardly of any practical use. Barring in the fluorescence mode, no technique can provide significant resolution enhancement simultaneously both in the reflection and fluorescence mode of the confocal microscope. This paper describes a technique based on aperture engineering that can significantly enhance the high spatial frequency content in the image of a confocal microscope, in principle, working either in the reflection or the fluorescence mode. Results obtained from numerical simulations and experimental implementation are presented.

  4. Confocal fluorescence microendoscopy of bronchial epithelium.

    PubMed

    Lane, Pierre M; Lam, Stephen; McWilliams, Annette; Leriche, Jean C; Anderson, Marshall W; Macaulay, Calum E

    2009-01-01

    Confocal microendoscopy permits the acquisition of high-resolution real-time confocal images of bronchial mucosa via the instrument channel of an endoscope. We report here on the construction and validation of a confocal fluorescence microendoscope and its use to acquire images of bronchial epithelium in vivo. Our objective is to develop an imaging method that can distinguish preneoplastic lesions from normal epithelium to enable us to study the natural history of these lesions and the efficacy of chemopreventive agents without biopsy removal of the lesion that can introduce a spontaneous regression bias. The instrument employs a laser-scanning engine and bronchoscope-compatible confocal probe consisting of a fiber-optic image guide and a graded-index objective lens. We assessed the potential of topical application of physiological pH cresyl violet (CV) as a fluorescence contrast-enhancing agent for the visualization of tissue morphology. Images acquired ex vivo with the confocal microendoscope were first compared with a bench-top confocal fluorescence microscope and conventional histology. Confocal images from five sites topically stained with CV were then acquired in vivo from high-risk smokers and compared to hematoxylin and eosin stained sections of biopsies taken from the same site. Sufficient contrast in the confocal imagery was obtained to identify cells in the bronchial epithelium. However, further improvements in the miniature objective lens are required to provide sufficient axial resolution for accurate classification of preneoplastic lesions. PMID:19405738

  5. How the confocal laser scanning microscope entered biological research.

    PubMed

    Amos, W B; White, J G

    2003-09-01

    A history of the early development of the confocal laser scanning microscope in the MRC Laboratory of Molecular Biology in Cambridge is presented. The rapid uptake of this technology is explained by the wide use of fluorescence in the 80s. The key innovations were the scanning of the light beam over the specimen rather than vice-versa and a high magnification at the level of the detector, allowing the use of a macroscopic iris. These were followed by an achromatic all-reflective relay system, a non-confocal transmission detector and novel software for control and basic image processing. This design was commercialized successfully and has been produced and developed over 17 years, surviving challenges from alternative technologies, including solid-state scanning systems. Lessons are pointed out from the unusual nature of the original funding and research environment. Attention is drawn to the slow adoption of the instrument in diagnostic medicine, despite promising applications. PMID:14519550

  6. Expanding Imaging Capabilities for Microfluidics: Applicability of Darkfield Internal Reflection Illumination (DIRI) to Observations in Microfluidics

    PubMed Central

    Kawano, Yoshihiro; Otsuka, Chino; Sanzo, James; Higgins, Christopher; Nirei, Tatsuo; Schilling, Tobias; Ishikawa, Takuji

    2015-01-01

    Microfluidics is used increasingly for engineering and biomedical applications due to recent advances in microfabrication technologies. Visualization of bubbles, tracer particles, and cells in a microfluidic device is important for designing a device and analyzing results. However, with conventional methods, it is difficult to observe the channel geometry and such particles simultaneously. To overcome this limitation, we developed a Darkfield Internal Reflection Illumination (DIRI) system that improved the drawbacks of a conventional darkfield illuminator. This study was performed to investigate its utility in the field of microfluidics. The results showed that the developed system could clearly visualize both microbubbles and the channel wall by utilizing brightfield and DIRI illumination simultaneously. The methodology is useful not only for static phenomena, such as clogging, but also for dynamic phenomena, such as the detection of bubbles flowing in a channel. The system was also applied to simultaneous fluorescence and DIRI imaging. Fluorescent tracer beads and channel walls were observed clearly, which may be an advantage for future microparticle image velocimetry (?PIV) analysis, especially near a wall. Two types of cell stained with different colors, and the channel wall, can be recognized using the combined confocal and DIRI system. Whole-slide imaging was also conducted successfully using this system. The tiling function significantly expands the observing area of microfluidics. The developed system will be useful for a wide variety of engineering and biomedical applications for the growing field of microfluidics. PMID:25748425

  7. Application of a reflectance model to the sensor planning system

    NASA Astrophysics Data System (ADS)

    Koutecký, Tomá?; Paloušek, David; Brandejs, Jan

    2015-05-01

    This study describes a new sensor planning system for the automatic generation of scanning positions based on a computer model of the part for digitization of sheet metal parts. The focus of this paper is in the application of a reflectance model into this sensor planning system. The goal of this sensor planning system and application of this model is to ensure fast, complete and accurate digitization of the parts for their inspection during serial-line production, especially in the automotive industry. A methodology of the sensor planning system consists of positions planning, their simulation for true visibility of the part elements using a reflectance model, and a simulation of the positions for robot reachability. Compared to previous studies, visual properties of the scanned parts' surface can be simulated precisely. The Nayar model is used as a reflectance model. This model is suitable for materials that are characterized by the combination of diffuse and specular reflections and uses three components of reflection: diffuse, specular lobe and specular spike. Results of the scanning that were obtained using an ATOS III Triple Scan fringe projection 3D scanner and a KUKA KR 60 HA industrial robot were compared to the simulation. The comparison based on the correspondence of the polygons area acquired in each sensor position (in simulation and in scanning) shows that in the performed measurements the median of differences between simulation and scanning is around 16%.

  8. Spectral reflectance of selected aqueous solutions for water quality applications

    NASA Technical Reports Server (NTRS)

    Querr, M. R.; Waring, R. C.; Holland, W. E.; Nijm, W.; Hale, G. M.

    1972-01-01

    The relative specular reflectances of individual aqueous solutions having a particular chemical salt content were measured in the 2 to 20 micrometers region of the infrared component or radiant flux. Distilled water was the reflectance standard. The angle of incidence was 70.03 deg plus or minus 0.23 deg. Absolute reflectances of the solutions for the same polarization and angle of incidence were computed by use of the measured relative reflectances, one of the Fresnel equations, and the optical constants of distilled water. Phase shift and phase difference spectra were obtained by respectively applying a Kramers-Kronig dispersion analysis to the absolute and relative reflectance spectra. The optical constants of the solutions were determined by algorithms commonly associated with the Kramers-Kronig analysis. Spectral signatures that qualitatively and quantitatively characterize the solute and that show structure of the infrared bands of water were noted in the phase difference spectra. The relative and absolute reflectances, the phase shift and phase difference spectra and the optical constants are presented in graphical form. Application of these results to remote sensing of the chemical quality of natural waters is discussed briefly.

  9. Confocal microscopy and multi-photon excitation microscopy of human skin in vivo

    E-print Network

    So, Peter

    , MA 02139 USA ptso@mit.edu Abstract: This paper compares tandem scanning reflected light confocal-dimensional microscopic biopsy of in vivo human skin: a new technique based on a flexible confocal microscope." J. MicrosConfocal microscopy and multi-photon excitation microscopy of human skin in vivo Barry R. Masters

  10. Reflectance of metallic indium for solar energy applications

    NASA Technical Reports Server (NTRS)

    Bouquet, F. L.; Hasegawa, T.

    1984-01-01

    An investigation has been conducted in order to compile quantitative data on the reflective properties of metallic indium. The fabricated samples were of sufficiently high quality that differences from similar second-surface silvered mirrors were not apparent to the human eye. Three second-surface mirror samples were prepared by means of vacuum deposition techniques, yielding indium thicknesses of approximately 1000 A. Both hemispherical and specular measurements were made. It is concluded that metallic indium possesses a sufficiently high specular reflectance to be potentially useful in many solar energy applications.

  11. High-speed multispectral confocal biomedical imaging.

    PubMed

    Carver, Gary E; Locknar, Sarah A; Morrison, William A; Ramanujan, V Krishnan; Farkas, Daniel L

    2014-03-01

    A new approach for generating high-speed multispectral confocal images has been developed. The central concept is that spectra can be acquired for each pixel in a confocal spatial scan by using a fast spectrometer based on optical fiber delay lines. This approach merges fast spectroscopy with standard spatial scanning to create datacubes in real time. The spectrometer is based on a serial array of reflecting spectral elements, delay lines between these elements, and a single element detector. The spatial, spectral, and temporal resolution of the instrument is described and illustrated by multispectral images of laser-induced autofluorescence in biological tissues. PMID:24658777

  12. High-speed multispectral confocal biomedical imaging

    PubMed Central

    Carver, Gary E.; Locknar, Sarah A.; Morrison, William A.; Krishnan Ramanujan, V.; Farkas, Daniel L.

    2014-01-01

    Abstract. A new approach for generating high-speed multispectral confocal images has been developed. The central concept is that spectra can be acquired for each pixel in a confocal spatial scan by using a fast spectrometer based on optical fiber delay lines. This approach merges fast spectroscopy with standard spatial scanning to create datacubes in real time. The spectrometer is based on a serial array of reflecting spectral elements, delay lines between these elements, and a single element detector. The spatial, spectral, and temporal resolution of the instrument is described and illustrated by multispectral images of laser-induced autofluorescence in biological tissues. PMID:24658777

  13. Stereoscopic images in confocal (tandem scanning) microscopy.

    PubMed

    Boyde, A

    1985-12-13

    Stereoscopic pair images with parallel projection geometry are obtained by through-focusing along two inclined axes while recording two (summed and stacked) images with a microscope with a very shallow depth of field. The two stack images sample the same depth slice of translucent or reflective specimens. The method will work most conveniently with a tandem scanning microscope (a direct-view, confocal scanning optical microscope). This is a direct method for recording stereo images that can be used to the limit of resolution in optical microscopy. It demonstrates a previously unrealized advantage of confocal optical microscopy. PMID:4071051

  14. Multimodal confocal hyperspectral imaging microscopy with wavelength sweeping source

    NASA Astrophysics Data System (ADS)

    Kim, Young-Duk; Do, Dukho; Yoo, Hongki; Gweon, DaeGab

    2015-02-01

    There exist microscopes that are able to obtain the chemical properties of a sample, because there are some cases in which it is difficult to find out causality of a phenomenon by using only the structural information of a sample. Obtaining the chemical properties of a sample is important in biomedical imaging, because most biological phenomena include changes in the chemical properties of the sample. Hyperspectral imaging (HSI) is one of the popular imaging methods for characterizing materials and biological samples by measuring the reflectance or emission spectrum of the sample. Because all materials have a unique reflectance spectrum, it is possible to analyze material properties and detect changes in the chemical properties of a sample by measuring the spectral changes with respect to the original spectrum. Because of its ability to measure the spectrum of a sample, HSI is widely used in materials identification applications such as aerial reconnaissance and is the subject of various studies in microscopy. Although there are many advantages to using the method, conventional HSI has some limitations because of its complex configuration and slow speed. In this research we propose a new type of multimodal confocal hyperspectral imaging microscopy with fast image acquisition and a simple configuration that is capable of both confocal and HSI microscopies.

  15. Confocal Microscopy Denis Semwogerere

    E-print Network

    Weeks, Eric R.

    Confocal microscopy was pioneered by Marvin Minsky in 1955 while he was a Junior Fellow at Harvard University.[1] Minsky's invention would perform a point-by-point image construction by focusing a point a single point at a time Minsky avoided most of the unwanted scattered light that obscures an image when

  16. Confocal Microscopy Core Facility

    Cancer.gov

    Susan H. Garfield, Facility Head Confocal Microscopy Core Facility, CCR, NCI, NIH Building 37, Room B114 E Tel: 301.435.6187 Fax: 301.496.0734 email: susan_garfield@nih.gov Poonam Mannan, Biologist Building 37, Room B114 F Tel: 301.451.7816 e-mail: mannan

  17. Reflections.

    ERIC Educational Resources Information Center

    Wilde, Sandra

    1996-01-01

    Reflects on four significant issues discussed in this issue devoted to teaching writers to spell: (1) how much time should be spent on spelling; (2) how kids can be helped to care more about spelling; (3) how stakeholders can be helped to understand the point of what educators are doing with spelling; and (4) where the national climate is heading…

  18. Confocal filtering in cathodoluminescence microscopy of nanostructures

    SciTech Connect

    Narváez, Angela C. E-mail: j.p.hoogenboom@tudelft.nl; Weppelman, I. Gerward C.; Moerland, Robert J.; Hoogenboom, Jacob P. E-mail: j.p.hoogenboom@tudelft.nl; Kruit, Pieter

    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??m 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??m 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. Diagnosis of Acanthamoeba keratitis in vivo with confocal microscopy.

    PubMed

    Winchester, K; Mathers, W D; Sutphin, J E; Daley, T E

    1995-01-01

    We present eight cases of Acanthamoeba keratitis. In each case; the Acanthamoeba organisms were visualized in the epithelium and anterior stroma using tandem scanning confocal microscopy. The organisms were highly reflective, ovoid, and were 10-25 microns in diameter. The Acanthamoeba organisms in the human corneas were identical in size and shape to Acanthamoeba organisms on an agar plate visualized with the same confocal microscope. Confocal microscopy is a useful method for identifying Acanthamoeba organisms in vivo within the corneal epithelium and anterior stroma. PMID:7712728

  20. Tunable fiber confocal sensor with LED

    NASA Astrophysics Data System (ADS)

    Weng, Chun-Jen; Lan, Tzu-Hsien; Hwang, Chi-Hung; Chu, Nien-Nan; Huang, Chien-Yao; Cheng, Pi-Ying

    2015-07-01

    A novel concept of confocal sensor based on focal lens is proposed to measure the displacement. The light source is a stabilized fiber coupled LED. A 1x2 graded-index multimode fiber optic coupler is used in this sensor. One port is a LED input port via SMA connector, another port is a LED output port connected to a reflective collimator and the other port is a reflective sensor port connected to a photo detector. The focusing sensor head is the cascade of a focal lens and a 20X objective lens. In this confocal displacement sensor, LED passes through a focal lens and an objective lens so that the LED beam focuses at a fixed focal point. A test target is placed after the objective lens. The displacement between the sensor head and a target can be measured quickly by detecting the reflective power according to the confocal principle. The long-term stability of LED is under 0.5%. The effective back focal length is varied from 5.67mm to 6.57mm by 0-290mA current driving so that the measuring range is about 0.9mm. The FWHM resolution of displacement is about 50?m. This sensor has the features of low cost, high stability, high precision and compact.

  1. The application of an ultrasonic shear wave reflection method for nondestructive testing of cement-based

    E-print Network

    The application of an ultrasonic shear wave reflection method for nondestructive testing of cement of an Ultrasonic Shear Wave Reflection Method for Nondestruc- tive Testing of Cement-Based Materials at Early Ages-based materials at early ages #12;#12;The Application of an Ultrasonic Shear Wave Reflection Method

  2. Bidirectional Reflectance Functions for Application to Earth Radiation Budget Studies

    NASA Technical Reports Server (NTRS)

    Manalo-Smith, N.; Tiwari, S. N.; Smith, G. L.

    1997-01-01

    Reflected solar radiative fluxes emerging for the Earth's top of the atmosphere are inferred from satellite broadband radiance measurements by applying bidirectional reflectance functions (BDRFs) to account for the anisotropy of the radiation field. BDRF's are dependent upon the viewing geometry (i.e. solar zenith angle, view zenith angle, and relative azimuth angle), the amount and type of cloud cover, the condition of the intervening atmosphere, and the reflectance characteristics of the underlying surface. A set of operational Earth Radiation Budget Experiment (ERBE) BDRFs is available which was developed from the Nimbus 7 ERB (Earth Radiation Budget) scanner data for a three-angle grid system, An improved set of bidirectional reflectance is required for mission planning and data analysis of future earth radiation budget instruments, such as the Clouds and Earth's Radiant Energy System (CERES), and for the enhancement of existing radiation budget data products. This study presents an analytic expression for BDRFs formulated by applying a fit to the ERBE operational model tabulations. A set of model coefficients applicable to any viewing condition is computed for an overcast and a clear sky scene over four geographical surface types: ocean, land, snow, and desert, and partly cloudy scenes over ocean and land. The models are smooth in terms of the directional angles and adhere to the principle of reciprocity, i.e., they are invariant with respect to the interchange of the incoming and outgoing directional angles. The analytic BDRFs and the radiance standard deviations are compared with the operational ERBE models and validated with ERBE data. The clear ocean model is validated with Dlhopolsky's clear ocean model. Dlhopolsky developed a BDRF of higher angular resolution for clear sky ocean from ERBE radiances. Additionally, the effectiveness of the models accounting for anisotropy for various viewing directions is tested with the ERBE along tract data. An area viewed from nadir and from the side give two different radiance measurements but should yield the same flux when converted by the BDRF. The analytic BDRFs are in very good qualitative agreement with the ERBE models. The overcast scenes exhibit constant retrieved albedo over viewing zenith angles for solar zenith angles less than 60 degrees. The clear ocean model does not produce constant retrieved albedo over viewing zenith angles but gives an improvement over the ERBE operational clear sky ocean BDRF.

  3. Any Way You Slice It—A Comparison of Confocal Microscopy Techniques

    PubMed Central

    Jonkman, James

    2015-01-01

    The confocal fluorescence microscope has become a popular tool for life sciences researchers, primarily because of its ability to remove blur from outside of the focal plane of the image. Several different kinds of confocal microscopes have been developed, each with advantages and disadvantages. This article will cover the grid confocal, classic confocal laser-scanning microscope (CLSM), the resonant scanning-CLSM, and the spinning-disk confocal microscope. The way each microscope technique works, the best applications the technique is suited for, the limitations of the technique, and new developments for each technology will be presented. Researchers who have access to a range of different confocal microscopes (e.g., through a local core facility) should find this paper helpful for choosing the best confocal technology for specific imaging applications. Others with funding to purchase an instrument should find the article helpful in deciding which technology is ideal for their area of research. PMID:25802490

  4. Confocal coded aperture imaging

    DOEpatents

    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.

  5. Confocal microscopy and exfoliative cytology

    PubMed Central

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

    2013-01-01

    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 screening a specimen resulted in saving of time. It added a certain amount of objectivity to the process of arriving at a diagnosis. PMID:24250082

  6. Appearance Measurements in Industry and their Application in Light Reflection Models

    E-print Network

    Durikovic, Roman

    Appearance Measurements in Industry and their Application in Light Reflection Models Roman to physical reflection parameters in- clude the small number of required measurements and the inexpensive commercially available in- struments necessary to acquire the data. We re- view light reflection models

  7. Reflectance spectroscopy: quantitative analysis techniques for remote sensing applications.

    USGS Publications Warehouse

    Clark, R.N.; Roush, T.L.

    1984-01-01

    Several methods for the analysis of remotely sensed reflectance data are compared, including empirical methods and scattering theories, both of which are important for solving remote sensing problems. The concept of the photon mean path length and the implications for use in modeling reflectance spectra are presented.-from Authors

  8. In vivo confocal microscopy of Thygeson's superficial punctate keratitis.

    PubMed

    Cheng, Lulu L; Young, Alvin L; Wong, Angus K K; Law, Ricky W K; Lam, Dennis S C

    2004-06-01

    A 56-year-old Chinese man diagnosed with Thygeson's keratitis by clinical biomicroscopy was examined using a tandem scanning confocal microscope. Among normal superficial epithelial cells, clumps of markedly enlarged epithelial cells were identified. Multiple highly reflective filamentary structures were observed in the deeper layers. Most of these lesions were linear; some demonstrated curled ends and others demonstrated branching lesions with 'sprouts'. No inflammatory cells were evident in the areas of corneal stroma sampled. In vivo confocal microscopy may be helpful in the diagnosis of Thygeson's superficial keratitis. To the best of our knowledge, we report the first in vivo confocal images of focal desquamation of epithelium and intraepithelial hyper-reflective linear lesions in English literature. PMID:15180847

  9. Subsurface Imaging of Integrated Circuits with Widefield and Confocal Microscopy Using

    E-print Network

    .65µm longitudinally. We compare this to results obtained with a confocal microscope and a NAIL and discuss the relative advantages and disadvantages of the widefield microscope. II. EXPERIMENT Reflection. The confocal microscope constructed for this study consists of a diode laser for illumination (=1.3µm), a 2x2

  10. Description and performance of a highly versatile, low-cost fiber-optic confocal Raman microscope

    E-print Network

    Myrick, Michael Lenn

    Description and performance of a highly versatile, low-cost fiber-optic confocal Raman microscope C for publication 29 September 1995 A versatile fiber-optic confocal Raman microscope has been developed. Fiber microspectroscopy e.g., fluorescence, reflectance, Raman . II. INSTRUMENTAL DESIGN The microscope Fig. 1 is designed

  11. MRS BULLETIN VOLUME 34 JUNE 2009 www.mrs.org/bulletin 397 Confocal Annular Aperture

    E-print Network

    by combining a confocal laser scan- ning microscope with a silicon numerical aperture increasing lens (NAIL is a single-path, reflection-mode fiber-optical scanning microscope that uses a single mode fiber- coupledMRS BULLETIN · VOLUME 34 · JUNE 2009 · www.mrs.org/bulletin 397 Confocal Annular Aperture

  12. Diffuse reflection imaging at terahertz frequencies for security applications

    NASA Astrophysics Data System (ADS)

    Dean, P.; Khanna, S.; Chakraborty, S.; Lachab, M.; Davies, A. G.; Linfield, E. H.

    2007-10-01

    We report diffuse reflection imaging of concealed powdered samples in atmospheric air using a quantum cascade laser operating at 2.83 THz. The imaging system uses a helium-cooled silicon bolometer for mapping radiation diffusely reflected and scattered from samples, and a room-temperature pyroelectric sensor for simultaneously acquiring a specular image. A range of powders concealed within plastic packaging and standard FedEx envelopes was imaged with a resolution of better than 0.5 mm, and it was possible to detect powdered samples concealed within packaging from which there was a strong component of surface reflection. The feasibility of performing dual-wavelength diffuse reflection imaging for identification of illicit drugs and explosives is discussed.

  13. Illumination and Reflectance Estimation with its Application in Foreground Detection

    PubMed Central

    Tu, Gang Jun; Karstoft, Henrik; Pedersen, Lene Juul; Jørgensen, Erik

    2015-01-01

    In this paper, we introduce a novel approach to estimate the illumination and reflectance of an image. The approach is based on illumination-reflectance model and wavelet theory. We use a homomorphic wavelet filter (HWF) and define a wavelet quotient image (WQI) model based on dyadic wavelet transform. The illumination and reflectance components are estimated by using HWF and WQI, respectively. Based on the illumination and reflectance estimation we develop an algorithm to segment sows in grayscale video recordings which are captured in complex farrowing pens. Experimental results demonstrate that the algorithm can be applied to detect the domestic animals in complex environments such as light changes, motionless foreground objects and dynamic background. PMID:26343675

  14. Combined Confocal and Magnetic Resonance Microscopy

    SciTech Connect

    Wind, Robert A.; Majors, Paul D.; Minard, Kevin R.; Ackerman, Eric J.; Daly, Don S.; Holtom, Gary R.; Thrall, Brian D.; Weber, Thomas J.

    2002-05-12

    Confocal and magnetic resonance microscopy are both used to study live cells in a minimally invasive way. Both techniques provide complementary information. Therefore, by examining cells simultaneously with both methodologies, more detailed information is obtained than is possible with each of the microscopes individually. In this paper two configurations of a combined confocal and magnetic resonance microscope described. In both cases the sample compartment is part of a temperature regulated perfusion system. The first configuration is capable of studying large single cells or three-dimensional cell agglomerates, whereas with the second configuration monolayers of mammalian cells can be investigated . Combined images are shown of Xenopus laevis frog oocytes, model JB6 tumor spheroids, and a single layer of Chinese hamster ovary cells. Finally, potential applications of the combined microscope are discussed.

  15. Effects of Reflection Category and Reflection Quality on Learning Outcomes during Web-Based Portfolio Assessment Process: A Case Study of High School Students in Computer Application Course

    ERIC Educational Resources Information Center

    Chou, Pao-Nan; Chang, Chi-Cheng

    2011-01-01

    This study examines the effects of reflection category and reflection quality on learning outcomes during Web-based portfolio assessment process. Experimental subjects consist of forty-five eight-grade students in a "Computer Application" course. Through the Web-based portfolio assessment system, these students write reflection, and join…

  16. Laboratory laser reflectance measurement and applications to asteroid surface analysis

    NASA Astrophysics Data System (ADS)

    Shaw, A.; Daly, M. G.; Cloutis, E. A.; Tait, K. T.; Izawa, M. R. M.; Barnouin, O. S.; Hyde, B. C.; Nicklin, I.

    2014-07-01

    Introduction Laboratory reflectance measurement of asteroid analogs is an important tool for interpreting the reflectance of asteroids. One dominant factor affecting how measured reflectance changes as a function of phase angle (180° minus the scattering angle) is surface roughness [1], which is related to grain size. A major goal of this study is to be able to use the angular distributions (phase functions) of scattered light from various regions on an asteroid surface to determine the relative grain size between those regions. Grain size affects the spectral albedo and continuum slopes of surface materials, has implications in terms of understanding geologic processes on asteroids and is also valuable for the planning and operations of upcoming missions to asteroids, such as the New Frontiers OSIRIS-REx sample return mission to the asteroid (101955) Bennu [2]. Information on surface roughness is particularly powerful when combined with other datasets, such as thermal inertia maps (e.g., a smooth, low-backscatter surface of low thermal inertia likely contains fine grains). Approach To better constrain the composition and surface texture of Bennu, we are conducting experiments to investigate the laser return signature of terrestrial and meteorite analogs to Bennu. The objective is to understand the nature of laser returns given possible compositional, grain size and slope distributions on the surface of Bennu to allow surface characterization, particularly surface grain size, which would significantly aid efforts to identify suitable sites for sampling by the OSIRIS-REx mission. Setup A 1064-nm laser is used to determine the reflectance of Bennu analogs and their constituents (1064 nm is the wavelength of many laser altimeters including the one planned to fly on OSIRIS-REx). Samples of interest include serpentinites (greenalite, etc.), magnetite, and shungite. To perform the experiments, a goniometer has been built. This instrument allows reflectance measurements at various illumination and viewing geometries. The goniometer has an an arm and a caddy that travels the length of an arc. Both the caddy and arm can accommodate either a source or detector. The arm rotates in azimuth and elevation, allowing data acquisition over the whole hemisphere. The optical assembly that we mount on the caddy for the first two sets of experiments described below has also been built. Experiments We have determined a series of three sets of experiments for measuring reflectance as a function of grain size while successively broadening the range of illumination and viewing geometries: 1) The first set of experiments involves measuring reflectance of a set of samples, each of a different grain size, at constant viewing and illumination geometry (nadir for both). 2) The second set of experiments involves a similar set of measurements, but this time the incidence angle will be varied, while keeping the phase angle constant (at zero, i.e., the lidar geometry). The results will be important for calibrating OSIRIS-REx Laser Altimeter (OLA) data, including separating the contributions of range, surface roughness, and surface composition. 3) The third set of experiments builds on the previous experiments by also allowing phase angle to vary, resulting in phase function (angular scattering intensity distribution) measurements. These data are particularly useful for the interpretation of OSIRIS-REx Visible and IR Spectrometer (OVIRS) and OSIRIS-REx Camera Suite (OCAMS) data taken at varying illumination and viewing geometries. These datasets can then be analyzed together with the OLA dataset for a more complete picture of surface reflectance characteristics. Conclusion The experiments outlined above and the resulting database are intended to benefit 1) proper interpretation of photometric data to determine surface roughness and 2) generation of albedo maps from laser altimeter measurements of planetary surfaces, such as that of Bennu. We have built a facility to collect this database of reflectance measurements, and the facility has already seen ''fi

  17. Reflection Imaging X-Ray Laser Microscope (RIXRALM) and its biological applications. Progress report

    SciTech Connect

    Suckewer, S.

    1998-07-01

    The main stimulus for the development of the proposed microscope (RIXRALM) is the possibility to view the surface and near surface structure of biological materials, such as cell membranes at much higher resolution than an optical (confocal) microscope. Although the prediction resolution of RIXRALM was lower than a Scanning Electron Microscope (SEM), the possibility to obtain images of cells (membranes) in a more natural, hydrated state and, in many cases, without staining, made the idea of a reflection X-ray microscope very attractive. The specimen can be in an H{sub 2}O saturated He atmosphere at atmospheric pressure. As the image can be obtained quickly (nsec exposure, occurring within seconds of insertion into such an environment), the cell surface can be seen in a state which is very close to its natural condition. Besides, the short exposure time eliminates the effect of motional blurring on the images. Their X-ray reflection microscope fit well in the very large gap in the size of biological objects studied in light microscopy (sub-micron size) and electron microscope (down to a few nanometers size).

  18. Simulation of a theta line-scanning confocal microscope.

    PubMed

    Simon, Blair; Dimarzio, Charles A

    2007-01-01

    We describe a 2-D computational model of the optical propagation of coherent light from a laser diode within human skin to better understand the performance of a confocal reflectance theta microscope. The simulation uses finite-difference time domain (FDTD) computations to solve Maxwell's equations in a synthetic skin model that includes melanin, mitochondria, and nuclei. The theta line-scanning confocal microscope configuration experiences more localized decreases in the signal than the confocal common-path point-scanning microscope. We hypothesize that these decreases result from the bistatic imaging configuration, the imaging geometry, and the inhomogeneity of the index of refraction of the skin. All these factors result in the source path having aberrations different than those of the receiver path. The model predicts signal decreases that are somewhat greater than those seen in experiments. New details on the reflection from a spherical object show that imaging with the theta line scanner leads to somewhat different results than would be seen with a common-path point scanner. The model is used to optimize the design of the theta line-scanning confocal microscope. PMID:18163836

  19. Cross-polarization confocal imaging of subsurface flaws in silicon nitride.

    SciTech Connect

    Liu, Z.; Sun, J. G.; Pei, Z.

    2011-03-01

    A cross-polarization confocal microscopy (CPCM) method was developed to image subsurface flaws in optically translucent silicon nitride (Si{sub 3}N{sub 4}) ceramics. Unlike conventional confocal microscopy, which measures reflected light so is applicable only to transparent and semi-transparent materials, CPCM detects scattered light from subsurface while filtering out the reflected light from ceramic surface. For subsurface imaging, the refractive-index mismatch between imaging (air) and imaged (ceramic) medium may cause image distortion and reduce resolution in the depth direction. This effect, characterized by an axial scaling factor (ASF), was analyzed and experimentally determined for glass and Si{sub 3}N{sub 4} materials. The experimental CPCM system was used to image Hertzian C-cracks generated by various indentation loads in the subsurface of a Si{sub 3}N{sub 4} specimen. It was demonstrated that CPCM may provide detailed information of subsurface cracks, such as crack angle and path, and subsurface microstructural variations.

  20. CONFOCAL MICROSCOPY SYSTEM PERFORMANCE: SPECTROSCOPY

    EPA Science Inventory

    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...

  1. 1748 J. Opt. Soc. Am. A/Vol. 4, No. 9/September 1987 Analytic inversion formula for confocal scanning

    E-print Network

    Bertero, Mario

    effective transparency (or reflectivity for a reflec- tion microscope) in the object plane; by this wemean1748 J. Opt. Soc. Am. A/Vol. 4, No. 9/September 1987 Analytic inversion formula for confocal a method for enhancing resolution in confocal scanning microscopy. 3 First we sum- marize the main points

  2. Confocal in vivo microscopy and confocal laser-scanning fluorescence microscopy in keratoconus.

    PubMed

    Somodi, S; Hahnel, C; Slowik, C; Richter, A; Weiss, D G; Guthoff, R

    1996-11-01

    The purpose of this study was the determination of morphological changes in the corneal epithelium and the keratocyte network in keratoconus. In all, 33 eyes of 19 patients were examined in vivo using the confocal slit-scanning microscope Microphthal. After penetrating keratoplasty, recipients' trephanates were stained with the Live/Dead kit and examined using the confocal laser-scanning fluorescence microscope Diaphot 300/Odyssey. The fluorescence images were reconstructed three-dimensionally. All findings were compared with data from healthy corneas. Morphological alterations were found only in the area of the corneal apex; obviously elongated superficial epithelial cells arranged in a whorl-like fashion were found. Near Bowman's membrane, highly reflective changes and fold-like structures were visible. The anterior stroma also showed an increased reflectivity. In the posterior stroma, typical findings were Vogt's striae and keratocytes with extremely long processes arranged nearly in parallel. In scarred stroma the keratocytes were spindle-shaped and arranged irregularly. The spatial organization of the living keratocyte network could be demonstrated through three-dimensional reconstructions. PMID:9479549

  3. Application of Kubelka-Munk theory of diffuse reflectance to geologic problems - The role of scattering

    NASA Technical Reports Server (NTRS)

    Morris, R. V.; Mendell, W. W.; Neely, S. C.

    1982-01-01

    An understanding of the reflectance spectra of scattering media is vital for the appropriate interpretation of the reflectance spectra of planetary surfaces. When the absorption coefficient (k) and the mean size of the scattering centers are small, the Kubelka-Munk (K-M) theory of diffuse reflectance is valid. Since small values of k are characteristic of a wide variety of geologically important materials over a significant range of wavelength, the K-M theory should be applicable to appropriate portions of the reflectance spectra of these media if the dimensions of the scattering centers are sufficiently small. To test the utility of the K-M theory, a comparison is conducted of a set of theoretically generated spectra with a set of independently measured experimental spectra. The similarities found in the behavior of the two sets of spectra demonstrate the applicability of the K-M theory to the understanding of physical phenomena. Aspects of wavelength-dependent scattering are investigated.

  4. Dye-Enhanced Multimodal Confocal Imaging of Brain Cancers

    NASA Astrophysics Data System (ADS)

    Wirth, Dennis; Snuderl, Matija; Sheth, Sameer; Curry, William; Yaroslavsky, Anna

    2011-04-01

    Background and Significance: Accurate high resolution intraoperative detection of brain tumors may result in improved patient survival and better quality of life. The goal of this study was to evaluate dye enhanced multimodal confocal imaging for discriminating normal and cancerous brain tissue. Materials and Methods: Fresh thick brain specimens were obtained from the surgeries. Normal and cancer tissues were investigated. Samples were stained in methylene blue and imaged. Reflectance and fluorescence signals were excited at 658nm. Fluorescence emission and polarization were registered from 670 nm to 710 nm. The system provided lateral resolution of 0.6 ?m and axial resolution of 7 ?m. Normal and cancer specimens exhibited distinctively different characteristics. H&E histopathology was processed from each imaged sample. Results and Conclusions: The analysis of normal and cancerous tissues indicated clear differences in appearance in both the reflectance and fluorescence responses. These results confirm the feasibility of multimodal confocal imaging for intraoperative detection of small cancer nests and cells.

  5. Optical Electronic Bragg Reflection Sensor System with Hydrodynamic Flow Applications

    NASA Technical Reports Server (NTRS)

    Lyons, D. R.

    2003-01-01

    This project, as described in the following report, involved design and fabrication of fiber optic sensors for the detection and measurement of dynamic fluid density variations. These devices are created using UV (ultraviolet) ablation and generally modified transverse holographic fiber grating techniques. The resulting phase gratings created on or immediately underneath the flat portion of D-shaped optical waveguides are characterized as evanescent field sensing devices. The primary applications include the sensor portion of a real-time localized or distributed measurement system for hydrodynamic flow, fluid density measurements, and phase change phenomena. Several design modifications were implemented in an attempt to accomplish the tasks specified in our original proposal. In addition, we have established key collaborative relationships with numerous people and institutions.

  6. Use of probe-based confocal laser endomicroscopy (pCLE) in gastrointestinal applications. A consensus report based on clinical evidence

    PubMed Central

    Wang, Kenneth K; Carr-Locke, David L; Singh, Satish K; Neumann, Helmut; Bertani, Helga; Arsenescu, Razvan I; Caillol, Fabrice; Chang, Kenneth J; Chaussade, Stanislas; Coron, Emmanuel; Costamagna, Guido; Dlugosz, Aldona; Ian Gan, S; Giovannini, Marc; Gress, Frank G; Haluszka, Oleh; Ho, Khek Y; Kahaleh, Michel; Konda, Vani J; Prat, Frederic; Shah, Raj J; Sharma, Prateek; Slivka, Adam; Wolfsen, Herbert C; Zfass, Alvin

    2015-01-01

    Background Probe-based confocal laser endomicroscopy (pCLE) provides microscopic imaging during an endoscopic procedure. Its introduction as a standard modality in gastroenterology has brought significant progress in management strategies, affecting many aspects of clinical care and requiring standardisation of practice and training. Objective This study aimed to provide guidance on the standardisation of its practice and training in Barrett’s oesophagus, biliary strictures, colorectal lesions and inflammatory bowel diseases. Methods Initial statements were developed by five group leaders, based on the available clinical evidence. These statements were then voted and edited by the 26 participants, using a modified Delphi approach. After two rounds of votes, statements were validated if the threshold of agreement was higher than 75%. Results Twenty-six experts participated and, among a total of 77 statements, 61 were adopted (79%) and 16 were rejected (21%). The adoption of each statement was justified by the grade of evidence. Conclusion pCLE should be used to enhance the diagnostic arsenal in the evaluation of these indications, by providing microscopic information which improves the diagnostic performance of the physician. In order actually to implement this technology in the clinical routine, and to ensure good practice, standardised initial and continuing institutional training programmes should be established. PMID:26137298

  7. Confocal spectral imaging by microspectrofluorometry using two-photon excitation: application to the study of anticancer drugs within single living cancer cells

    NASA Astrophysics Data System (ADS)

    Chourpa, Igor; Pereira, Manuela; Millot, Jean-Marc; Morjani, Hamid; Manfait, Michel

    1999-06-01

    The use of the two-photon excitation (TPE) is believed to be prominent for fluorometric studies with cells. We evaluated the advantages and limitations of the two-photon technique compared to the single photon one when it used to detect potent anticancer drugs, camptothecins (CPTs), within single living cancer cells. The technique we used was confocal microspectrofluorometry amplified with possibility of the spectral imaging analysis. We have previously reported the use of the florescence emission of CPTs to study them qualitatively and quantitatively, namely, to follow the status of their hydrolyzable lactone moiety. However, the intracellular investigation of CPTs using microspectrofluorometry with single photon UV excitation (SPE) is hindered by significant interference of their fluorescence emission with cellular autofluorescence. We attempted to overcome these problems using the two-photon excitation. The intracellular single-photon- and two-photon-excited emission spectra from treated and control cells (HCT-116 line) were recorded using a spectral imaging approach. The obtained data demonstrate that, apart from intrinsically increased three- dimensional resolution, the two-photon approach was advantageous over the single-photon method with respect to selective fluorometric detection of intracellular CPTs. Nevertheless, much attention should be paid to avoid any excessive irradiation of the cells with UV and even NIR light.

  8. Simplified confocal microscope for counting particles at low concentrations

    NASA Astrophysics Data System (ADS)

    Skinner, Joseph P.; Swift, Kerry M.; Ruan, Qiaoqiao; Perfetto, Sergio; Gratton, Enrico; Tetin, Sergey Y.

    2013-07-01

    We describe a compact scanning confocal fluorescence microscope capable of detecting particles concentrations less than 100 particles/ml in ˜15 min. The system mechanically moves a cuvette containing ˜3 ml of sample. A relatively large confocal volume is observed within the cuvette using a 1 mm pinhole in front of a detection PMT. Due to the motion of the sample, particles traverse the confocal volume quickly, and analysis by pattern recognition qualifies spikes in the emission intensity data and counts them as events. We show linearity of detection as a function of concentration and also characterize statistical behavior of the instrument. We calculate a detection sensitivity of the system using 3 ?m fluorescent microspheres to be 5 particles/ml. Furthermore, to demonstrate biological application, we performed a dilution series to quantify stained E. coli and yeast cells. We counted E. coli cells at a concentration as low as 30 cells/ml in 10 min/sample.

  9. The feasibility of digitally stained multimodal confocal mosaics to simulate histopathology

    PubMed Central

    Gareau, Daniel S.

    2010-01-01

    Fluorescence confocal mosaicing microscopy of tissue biopsies stained with acridine orange has been shown to accurately identify tumors and with an overall sensitivity of 96.6% and specificity of 89.2%. However, fluorescence shows only nuclear detail similar to hematoxylin in histopathology and does not show collagen or cytoplasm, which may provide necessary negative contrast information similar to eosin used in histopathology. Reflectance mode contrast is sensitive to collagen and cytoplasm without staining. To further improve sensitivity and specificity, digitally stained confocal mosaics combine confocal fluorescence and reflectance images in a multimodal pseudo-color image to mimic the appearance of histopathology with hematoxylin and eosin and facilitate the introduction of confocal microscopy into the clinical realm. PMID:19566342

  10. Confocal Raman microspectroscopy of the skin.

    PubMed

    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. PMID:21914580

  11. Study of liquid jet instability by confocal microscopy

    NASA Astrophysics Data System (ADS)

    Yang, Lisong; Adamson, Leanne J.; Bain, Colin D.

    2012-07-01

    The instability of a liquid microjet was used to measure the dynamic surface tension of liquids at the surface ages of ?1 ms using confocal microscopy. The reflected light from a laser beam at normal incidence to the jet surface is linear in the displacement of the surface near the confocal position, leading to a radial resolution of 4 nm and a dynamic range of 4 ?m in the surface position, thus permitting the measurement of amplitude of oscillation at the very early stage of jet instability. For larger oscillations outside the linear region of the confocal response, the swell and neck position of the jet can be located separately and the amplitude of oscillation determined with an accuracy of 0.2 ?m. The growth rate of periodically perturbed water and ethanol/water mixture jets with a 100-?m diameter nozzle and mean velocity of 5.7 m s-1 has been measured. The dynamic surface tension was determined from the growth rate of the instability with a linear, axisymmetric, constant property model. Synchronisation of the confocal imaging system with the perturbation applied to the jet permitted a detailed study of the temporal evolution of the neck into a ligament and eventually into a satellite drop.

  12. Optimization of In Vivo Confocal Autofluorescence Imaging of the Ocular Fundus in Mice and Its Application to Models of Human Retinal Degeneration

    PubMed Central

    Issa, Peter Charbel; Singh, Mandeep S.; Lipinski, Daniel M.; Chong, Ngaihang V.; Delori, François C.; Barnard, Alun R.; MacLaren, Robert E.

    2012-01-01

    Purpose. To investigate the feasibility and to identify sources of experimental variability of quantitative and qualitative fundus autofluorescence (AF) assessment in mice. Methods. Blue (488 nm) and near-infrared (790 nm) fundus AF imaging was performed in various mouse strains and disease models (129S2, C57Bl/6, Abca4?/?, C3H-Pde6brd1/rd1, Rho?/?, and BALB/c mice) using a commercially available scanning laser ophthalmoscope. Gray-level analysis was used to explore factors influencing fundus AF measurements. Results. A contact lens avoided cataract development and resulted in consistent fundus AF recordings. Fundus illumination and magnification were sensitive to changes of the camera position. Standardized adjustment of the recorded confocal plane and consideration of the pupil area allowed reproducible recording of fundus AF from the retinal pigment epithelium with an intersession coefficient of repeatability of ±22%. Photopigment bleaching occurred during the first 1.5 seconds of exposure to 488 nm blue light (?10 mW/cm2), resulting in an increase of fundus AF. In addition, there was a slight decrease in fundus AF during prolonged blue light exposure. Fundus AF at 488 nm was low in animals with an absence of a normal visual cycle, and high in BALB/c and Abca4?/? mice. Degenerative alterations in Pde6brd1/rd1 and Rho?/? were reminiscent of findings in human retinal disease. Conclusions. Investigation of retinal phenotypes in mice is possible in vivo using standardized fundus AF imaging. Correlation with postmortem analysis is likely to lead to further understanding of human disease phenotypes and of retinal degenerations in general. Fundus AF imaging may be useful as an outcome measure in preclinical trials, such as for monitoring effects aimed at lowering lipofuscin accumulation in the retinal pigment epithelium. PMID:22169101

  13. A Love Wave Reflective Delay Line with Polymer Guiding Layer for Wireless Sensor Application

    PubMed Central

    Wang, Wen; He, Shitang

    2008-01-01

    This paper presents an optimal design for a Love wave reflective delay line on 41° YX LiNbO3 with a polymer guiding layer for wireless sensor applications. A theoretical model was established to describe the Love wave propagation along the larger piezoelectric substrate with polymer waveguide, and the lossy mechanism from the viscoelastic waveguide was discussed, which results in the optimal guiding layer thickness. Coupling of modes (COM) was used to determine the optimal design parameters of the reflective delay line structured by single phase unidirectional transducers (SPUDTs) and shorted grating reflectors. Using the network analyzer, the fabricated Love wave reflective delay line was characterized, high signal noise ratio (S/N), sharp reflection peaks, and few spurious noise between the peaks were found, and the measured result agrees well with the simulated one. Also, the optimal guiding layer thickness of 1.5?1.8µm was extracted experimentally, and it is consistent with the theoretical analysis.

  14. Applications of high power lasers. [using reflection holograms for machining and surface treatment

    NASA Technical Reports Server (NTRS)

    Angus, J. C.

    1979-01-01

    The use of computer generated, reflection holograms in conjunction with high power lasers for precision machining of metals and ceramics was investigated. The Reflection holograms which were developed and made to work at both optical wavelength (He-Ne, 6328 A) and infrared (CO2, 10.6) meet the primary practical requirement of ruggedness and are relatively economical and simple to fabricate. The technology is sufficiently advanced now so that reflection holography could indeed be used as a practical manufacturing device in certain applications requiring low power densities. However, the present holograms are energy inefficient and much of the laser power is lost in the zero order spot and higher diffraction orders. Improvements of laser machining over conventional methods are discussed and addition applications are listed. Possible uses in the electronics industry include drilling holes in printed circuit boards making soldered connections, and resistor trimming.

  15. Operator reflection positivity inequalities and their applications to interacting quantum rotors

    E-print Network

    Jacek Wojtkiewicz; Wies?aw Pusz; Piotr Stachura

    2015-07-11

    In the Reflection Positivity theory and its application to statistical mechanical systems, certain matrix inequalities play a central role. The Dyson-Lieb-Simon and Kennedy-Lieb-Shastry-Schupp inequalities constitute prominent examples. In this paper we extend the KLS-S inequality to the case where matrices are replaced by certain operators. As an application, we prove the occurrence of the long range order in the ground state of two-dimensional quantum rotors.

  16. "Knowing Is Not Enough; We Must Apply": Reflections on a Failed Action Learning Application

    ERIC Educational Resources Information Center

    Reese, Simon

    2015-01-01

    This paper reflects upon a sub-optimal action learning application with a strategic business re-design project. The objective of the project was to improve the long-term business performance of a subsidiary business and build the strategic plan. Action learning was introduced to aid the group in expanding their view of the real problems…

  17. Optical reflectivity of solid and liquid methane: Application to spectroscopy of Titan's hydrocarbon lakes

    E-print Network

    Jacobsen, Steven D.

    Optical reflectivity of solid and liquid methane: Application to spectroscopy of Titan direct observations for interpreting their surface compositions. At Titan, the Cassini spacecraft and southern latitudes of Titan. Citation: Adams, K. A., S. D. Jacobsen, Z. Liu, S.-M. Thomas, M. Somayazulu

  18. Immunofluorescence and Confocal Microscopy of Neutrophils

    PubMed Central

    Allen, Lee-Ann H.

    2015-01-01

    Rapid recruitment of neutrophils to sites of infection and their ability to phagocytose and kill microbes is an important aspect of the innate immune response. Challenges associated with imaging of these cells include their short lifespan and small size and the fact that unstimulated cells are nonadherent. In addition, although cytoplasmic granules are plentiful, the abundance of many other organelles is diminished. Here we reprise methods for analysis of resting and activated cells using immunofluorescence and confocal microscopy, including kinetic analysis of phagosome maturation and degranulation, and detection of intraphagosomal superoxide accumulation. We describe approaches for rapid cell fixation and permeabilization that maximize antigen detection and discuss other variables that also affect data interpretation and image quality (such as cell spreading, degranulation, and phagocytosis). Finally, we show that these methods are also applicable to studies of neutrophil interactions with the extracellular matrix. PMID:24504957

  19. EVALUATION OF CONFOCAL MICROSCOPY SYSTEM PERFORMANCE: PRETTY PICTURES OR CONFOCAL QA

    EPA Science Inventory

    Evaluation of confocal microscopy system performance: Pretty pictures or confocal QA?

    Robert M. Zucker

    Reproductive Toxicology Division, National Health and Environmental Effects Research Laboratory, U.S. Environmental Protection Agency, Research Triangle Park, N...

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

    E-print Network

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

    2010-01-01

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

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

    E-print Network

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

    2010-10-09

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

  2. Clinical feasibility of rapid confocal melanoma feature detection

    NASA Astrophysics Data System (ADS)

    Hennessy, Ricky; Jacques, Steve; Pellacani, Giovanni; Gareau, Daniel

    2010-02-01

    In vivo reflectance confocal microscopy shows promise for the early detection of malignant melanoma. One diagnostic trait of malignancy is the presence of pagetoid melanocytes in the epidermis. For automated detection of MM, this feature must be identified quantitatively through software. Beginning with in vivo, noninvasive confocal images from 10 unequivocal MMs and benign nevi, we developed a pattern recognition algorithm that automatically identified pagetoid melanocytes in all four MMs and identified none in five benign nevi. One data set was discarded due to artifacts caused by patient movement. With future work to bring the performance of this pattern recognition technique to the level of the clinicians on difficult lesions, melanoma diagnosis could be brought to primary care facilities and save many lives by improving early diagnosis.

  3. Confocal theta line-scanning microscope for imaging human tissues.

    PubMed

    Dwyer, Peter J; DiMarzio, Charles A; Rajadhyaksha, Milind

    2007-04-01

    A confocal reflectance theta line-scanning microscope demonstrates imaging of nuclear and cellular morphology in human skin and oral mucosa in vivo. The illumination and detection are through a divided objective lens pupil, resulting in a theta-microscope configuration. A line is directly scanned in the pupil and descanned onto a linear detector array such that the theta line scanner consists of only seven main optical components. The experimentally measured lateral resolution is 1.0 microm and optical section thickness is 1.7 microm under nominal conditions at 830 nm wavelength. Through full-thickness human epidermis (i.e., in the dermis) the measured lateral resolution is 1.7 microm and the optical section thickness is 9.2 microm. The lateral resolution, sectioning, and image quality in epidermal (epithelial) tissue is comparable to that of point scanning confocal microscopy. PMID:17356629

  4. Time course effect and sequential morphological changes of subepidermal nerve fibers in guinea pig skin after application of histamine ointment: a laser scanning confocal fluorescence microscopic and electron microscopic study.

    PubMed

    Rivera, Maria Rosario P; Mihara, Motoyuki

    2004-05-01

    This study was undertaken to elucidate the morphological effects of histamine on subepidermal nerve fibers. A 10% histamine ointment was topically applied to the back skin of 17 adult male Hartley guinea pigs. Biopsy specimens were obtained at times from 5 min to 24 h, and were examined by conventional immunofluorescence (IF), laser scanning confocal fluorescence microscopy (LSCM) and transmission electron microscopy. On IF and LSCM, marked diminutions in the immunoreactivity of protein gene product 9.5-immunoreactive (PGP 9.5-IR) fibers as well as of substance P-immunoreactive (SP-IR) and calcitonin gene-related peptide-immunoreactive (CGRP-IR) substances were observed 5 min after histamine application. By 30 min, immunoreactivity of PGP 9.5, SP and CGRP was completely lost. By 2 h, however, immunoreactivity of PGP 9.5-IR fibers and CGRP-IR substances started to show recovery. By 4 h, immunoreactivity of PGP 9.5, SP and CGRP had almost recovered, but the recovery time for each substance was slightly different (PGP 9.5 first, CGRP next, and SP last). By 6 h after histamine application, immunoreactivity of all these substances had fully recovered. Ultrastructurally, 5 min after histamine application, axonal and mitochondrial swelling and glycogen deposition were seen in the axons of subepidermal nerve fibers. By 30 min, severe axonal degeneration had occurred in some of the axons. It was only by 4 to 6 h that almost normal ultrastructural features were observed. Schwann cells and perineurial cells did not show any pathological changes. These findings demonstrate that 10% histamine ointment produced organic changes in the axons in the subepidermal nerve fibers of guinea pig skin, but these morphological changes were short-lived, reversible and transitory. PMID:15048579

  5. Diagnosis of microsporidial keratitis with in vivo confocal microscopy.

    PubMed

    Hsiao, Ya-Chuan; Tsai, I-Lun; Kuo, Chin-Tzu; Yang, Tsung-Lin

    2013-01-01

    As a rare cause of microbial keratitis, microsporidial keratitis (MK) is first described in a patient with acquired immunodeficiency syndrome. As increased use of topical steroid creates a localized immunosuppressive environment of the eyes, MK occurs more commonly than expected in immunocompetent patients nowadays. Owing to initial insidious growth of pathogens and nonspecific ocular symptoms of infected patients, its frequent misdiagnosis has posed a major clinical challenge in recent decades. Without appropriate treatments, MK can progress deeply into corneal stroma, anterior and posterior segments, subsequently deteriorating vision severely and ultimately requiring corneal transplant. Related risk factors for the occurrence of MK in immunocompetent individuals include contact lens wear, topical steroid use, previous corneal trauma, and a history of laser refractive surgery. The conventional standard of MK diagnosis is based on a tissue biopsy by superficial corneal scrapping. In vivo confocal laser scanning microscopy can obtain images through the cornea in a plane paralleling to the vertical axis. This approach provides an effective method of identifying tissue layers that correspond to corneal histologic structures. This current study investigates the efficacy of \\textit{in vivo} confocal laser scanning microscopy in diagnosing MK in immunocompetent patients. The clinical presentations of enrolled patients, including features of slit lamp biomicroscopy and the histopathological results of corneal scrapping, were described. In these patients, the confocal microscopy identified multiple small intracellular hyper-reflective dots in the cytoplasm of corneal epithelial cells and stromal keratocytes. Additionally, the confocal microscopic images clearly revealed the enhanced cytoplasm of cell with intracellular round hyper-reflective dots. The size and morphology of hyper-reflective dots were compatible with the spores of microsporidia found in corneal tissue. Moreover, vision recovered after topical use of antimicrobial medicine. This observation suggests that in vivo confocal laser scanning microscopy provides a rapid, non-invasive, and high resolution scheme for diagnosing MK. In addition to diminishing the risk of secondary infection from epithelial defect created by superficial debridement, this approach facilitates early diagnosis and appropriate treatments. Furthermore, from a series of images taken during the clinical courses, this method is highly promising for use in monitoring treatment effects and identifying the recurrence of MK. PMID:23507856

  6. EVALUATION OF CONFOCAL MICROSCOPY SYSTEM PERFORMANCE

    EPA Science Inventory

    BACKGROUND. The confocal laser scanning microscope (CLSM) has enormous potential in many biological fields. Currently there is a subjective nature in the assessment of a confocal microscope's performance by primarily evaluating the system with a specific test slide provided by ea...

  7. Experimental Two-Photon Confocal Microscopy: A

    E-print Network

    So, Peter

    -thickness guinea pig skin wounds was stud- ied over a period of 28 days using two-photon confocal microscopy. Three sections. Two-photon confocal microscopy images show resolution of muscle, fascia fi- bers, collagen fibers of standard histology, the ability to noninva- sively acquire three-dimensional images of skin promises

  8. Reflection asymmetric relativistic mean field approach and its application to the octupole deformed nucleus $^{226}$Ra

    E-print Network

    L. S. Geng; J. Meng; H. Toki

    2007-06-04

    A Reflection ASymmetric Relativistic Mean Field (RAS-RMF) approach is developed by expanding the equations of motion for both the nucleons and the mesons on the eigenfunctions of the two-center harmonic-oscillator potential. The efficiency and reliability of the RAS-RMF approach are demonstrated in its application to the well-known octupole deformed nucleus $^{226}$Ra and the available data, including the binding energy and the deformation parameters, are well reproduced.

  9. Characterization and applications of a pure phase reflective liquid crystal spatial light modulator

    NASA Astrophysics Data System (ADS)

    Pérez, Joaquín O.; Ambs, Pierre

    2006-05-01

    We present the characterization of a pure phase reflective liquid crystal spatial light modulator. This modulator is electrically addressed and is based on nematic liquid crystal. Its performance in terms of frame rate, phase modulation versus gray level and wavefront distortion is experimentally evaluated. It is shown that after adding phase compensation and applying an appropriate Look-Up-Table, this spatial light modulator is an excellent candidate for applications such as dynamic diffractive optical elements, wavefront generation and dynamic zoom lens.

  10. Visualisation by confocal microscopy of traces on bullets and cartridge cases.

    PubMed

    Bonfanti, M S; Ghauharali, R I

    2000-01-01

    The capabilities of confocal scanning laser microscopy for the visualisation of marks on bullets and cartridge cases were investigated. Confocal microscopy provides solutions to important limitations of conventional comparison microscopy with grazing light incidence, as generally used for the examination of these marks. It is expected that confocal microscopy, thanks to its broad applicability within the field of firearms investigation and its capability of non-destructively gathering quantitative three-dimensional information, will lead to a more complete and objective forensic examination of bullets and cartridge cases. PMID:11094821

  11. ARES: a new reflective/emissive imaging spectrometer for terrestrial applications

    NASA Astrophysics Data System (ADS)

    Mueller, Andreas A.; Richter, Rolf; Habermeyer, Martin; Mehl, Harald; Dech, Stefan; Kaufmann, Hermann J.; Segl, Karl; Strobl, Peter; Haschberger, Peter; Bamler, Richard

    2003-04-01

    A new airborne imaging spectrometer introduced: the ARES (Airborne Reflective Emissive Spectrometer) to be built by Integrated Spectronics, Sydney, Australia, financed by DLR German Aerospace Center and the GFZ GeoResearch Center Potsdam, Germany, and will be available to the scientific community from 2003/2004 on. The ARES sensor will provide 160 channels in the solar reflective region (0.45-2.45 ?m) and the thermal region (8-13 ?m). It will consists of two separate coregistered optical systems for the reflective and thermal part of the spectrum. The spectral resolution is intended to be between 12 and 15 nm in the solar wavelength range and should reach 150nm in the thermal. ARES will be used mainly for environmental applications in terrestrial ecosystems. The thematic focus is thought to be on soil sciences, geology, agriculture and forestry. Limnologic applications should be possible but will not play a key role in the thematic applications. For all above mentioned key application scenarios the spectral response of soils, rocks, and vegetation as well as their mixtures contain the valuable information to be extracted and quantified. The radiometric requirements for the instrument have been modelled based on realistic application scenarios and account for the most demanding requirements of the three application fields: a spectral bandwidth of 15 nm in the 0.45-1.8 ?m region, and 12 nm in the 2 - 2.45 ?m region. The required noise equivalent radiance is 0.005, 0.003, and 0.003 mWcm-2sr-1?m-1 for the spectral regions 0.45-1 ?m, 1 - 1.8 ?m, and 2 - 2.45 ?m, respectively.

  12. Integrated photoacoustic, confocal, and two-photon microscope

    PubMed Central

    Rao, Bin; Soto, Florentina; Kerschensteiner, Daniel; Wang, Lihong V.

    2014-01-01

    Abstract. The invention of green fluorescent protein and other molecular fluorescent probes has promoted applications of confocal and two-photon fluorescence microscopy in biology and medicine. However, exogenous fluorescence contrast agents may affect cellular structure and function, and fluorescence microscopy cannot image nonfluorescent chromophores. We overcome this limitation by integrating optical-resolution photoacoustic microscopy into a modern Olympus IX81 confocal, two-photon, fluorescence microscope setup to provide complementary, label-free, optical absorption contrast. Automatically coregistered images can be generated from the same sample. Imaging applications in ophthalmology, developmental biology, and plant science are demonstrated. For the first time, in a familiar microscopic fluorescence imaging setting, this trimodality microscope provides a platform for future biological and medical discoveries. PMID:24589986

  13. Z-polarized confocal microscopy.

    PubMed

    Huse, N; Schönle, A; Hell, S W

    2001-10-01

    In light microscopy the transverse nature of the electromagnetic field precludes a strongly focused longitudinal field component, thus confining polarization spectroscopy and imaging to two dimensions (x,y). Here we describe a simple confocal microscopy arrangement that optimizes for signal from molecules with transition dipoles oriented parallel to the optic axis. In the proposed arrangement, we not only generate a predominant longitudinally (z) polarized focal field, but also engineer the detection scheme in such a way that in a bulk of randomly oriented molecules, the microscope's effective point-spread function is dominated by the contribution of those molecules that are oriented along the optic axis. Our arrangement not only implicitly allows for the determination of the orientation of transition dipoles of single molecules in three dimensions, but also highlights the contribution of z-oriented molecules in three-dimensional imaging. PMID:11806348

  14. Z-polarized confocal microscopy.

    PubMed

    Huse, N; Schönle, A; Hell, S W

    2001-07-01

    In light microscopy the transverse nature of the electromagnetic field precludes a strongly focused longitudinal field component, thus confining polarization spectroscopy and imaging to two dimensions (x,y). Here we describe a simple confocal microscopy arrangement that optimizes for signal from molecules with transition dipoles oriented parallel to the optic axis. In the proposed arrangement, we not only generate a predominant longitudinally (z) polarized focal field, but also engineer the detection scheme in such a way that in a bulk of randomly oriented molecules, the microscope's effective point-spread function is dominated by the contribution of those molecules that are oriented along the optic axis. Our arrangement not only implicitly allows for the determination of the orientation of transition dipoles of single molecules in three dimensions, but also highlights the contribution of z-oriented molecules in three-dimensional imaging. PMID:11516316

  15. Confocal endomicroscopy of the larynx

    NASA Astrophysics Data System (ADS)

    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 ?m 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 ?m and reach average penetration depths of 100-300 ?m (?/4 plate of the scanner head of the HRTII was removed). The lateral and axial resolutions are about 1-2 ?m and 2 ?m, 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.

  16. [Application and prospect of near infrared reflectance spectroscopy in forage analysis].

    PubMed

    Ren, Xiu-Zhen; Guo, Hong-Ru; Jia, Yu-Shan; Ge, Gen-Tu; Wang, Kun

    2009-03-01

    Forage was the material basis of animal husbandry production, and its quality is directly related to the quality of animal products. It was very important to control the forage quality and detect the composition of forage raw materials in forage production. Predication of forage quality was often completed by the traditional and classical methods in the past, which were complex, time consuming and expensive, and could not acquire the nutritional value of forage timely. Near infrared reflectance spectroscopy was a highly efficient and rapid modern analysis technique developed in 1970's. It comprehensively applied the latest research results of computer technique, spectroscopy and chemometrics, and has been widely used in various fields owing to its unique advantages such as being timely, less expensive, non-destructive, and so on. Near infrared reflectance spectroscopy has gained more and more importance though its application to forage analysis was very late. Presently, not only conventional composition (such as moisture, dry matter, crude protein, crude fiber, crude fat, crude ash neutral detergent fiber, acid detergent fiber, etc.), but also non-conventional composition (including minerals, trace elements, enzyme and anti-nutritional factors etc. ) and anti-nutritional factors in forage were determined by means of near infrared reflectance spectroscopy. Testing and analyzing the conventional composition in forage was the traditional applied field of near infrared reflectance spectroscopy, a lot of studies of which were done and it has already been one of the standard methods of testing the conventional composition. Forage bioavaibility was also evaluated by near infrared reflectance spectroscopy, so as to assess the utilization rate and nutritional value of forage. Moreover, near infrared spectroscopy could be used successfully to predict the botanical composition in grassland and leaf/stem ratios. Near infrared spectroscopy technique and its application and prospect in forage analysis were reviewed in the present paper. PMID:19455789

  17. Chromatic confocal microscope using hybrid aspheric diffractive lenses

    NASA Astrophysics Data System (ADS)

    Rayer, Mathieu; Mansfield, Daniel

    2014-05-01

    A chromatic confocal microscope is a single point non-contact distance measurement sensor. For three decades the vast majority of the chromatic confocal microscope use refractive-based lenses to code the measurement axis chromatically. However, such an approach is limiting the range of applications. In this paper the performance of refractive, diffractive and Hybrid aspheric diffractive are compared. Hybrid aspheric diffractive lenses combine the low geometric aberration of a diffractive lens with the high optical power of an aspheric lens. Hybrid aspheric diffractive lenses can reduce the number of elements in an imaging system significantly or create large hyper- chromatic lenses for sensing applications. In addition, diffractive lenses can improve the resolution and the dynamic range of a chromatic confocal microscope. However, to be suitable for commercial applications, the diffractive optical power must be significant. Therefore, manufacturing such lenses is a challenge. We show in this paper how a theoretical manufacturing model can demonstrate that the hybrid aspheric diffractive configuration with the best performances is achieved by step diffractive surface. The high optical quality of step diffractive surface is then demonstrated experimentally. Publisher's Note: This paper, originally published on 5/10/14, was replaced with a corrected/revised version on 5/19/14. If you downloaded the original PDF but are unable to access the revision, please contact SPIE Digital Library Customer Service for assistance.

  18. A handheld laser scanning confocal reflectance imagingconfocal Raman

    E-print Network

    Lawrence, Rick L.

    of samples at micron-scale resolutions. Current studies utilizing these techniques often employ large bench to microscale transport processes," Phys. Chem. Earth, Part A Solid Earth Geod. 24(7), 551­561 (1999). 4. K. D

  19. Big five personality traits reflected in job applicants' social media postings.

    PubMed

    Stoughton, J William; Thompson, Lori Foster; Meade, Adam W

    2013-11-01

    Job applicants and incumbents often use social media for personal communications allowing for direct observation of their social communications "unfiltered" for employer consumption. As such, these data offer a glimpse of employees in settings free from the impression management pressures present during evaluations conducted for applicant screening and research purposes. This study investigated whether job applicants' (N=175) personality characteristics are reflected in the content of their social media postings. Participant self-reported social media content related to (a) photos and text-based references to alcohol and drug use and (b) criticisms of superiors and peers (so-called "badmouthing" behavior) were compared to traditional personality assessments. Results indicated that extraverted candidates were prone to postings related to alcohol and drugs. Those low in agreeableness were particularly likely to engage in online badmouthing behaviors. Evidence concerning the relationships between conscientiousness and the outcomes of interest was mixed. PMID:23790360

  20. Confocal Fluorescence Microscopy of Mung Beanleaves

    NASA Astrophysics Data System (ADS)

    Chen, Zhiwei; Liu, Dongwu

    Recently, confocal microscope has become a routine technique and indispensable tool for cell biological studies and molecular investigations. The light emitted from the point out-of-focus is blocked by the pinhole and can not reach the detector, which is one of the critical features of the confocal microscope. In present studies, the probes acridine orange (AO) and rhodamine-123 were used to research stoma and mitochondria of mung bean leaves, respectively. The results indicated that the stomatal guard cells and mitochondria were clearly seen in epidermic tissue of mung bean leaves. Taken together, it is a good method to research plant cells with confocal microscope and fluorescence probes.

  1. Submillimeter Confocal Imaging Active Module

    NASA Technical Reports Server (NTRS)

    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 to be aimed in slightly different directions, and, hence, to not overlap fully on the targets on the ground. However, a preliminary analysis has shown that the loss of overlap would be small enough that the resulting loss in signal-to-noise ratio (SNR) would be much less than the SNR loss associated with the use of a 340-GHz T/R switch.

  2. Confocal microscopy of skin cancers: Translational advances toward clinical utility

    PubMed Central

    Rajadhyaksha, Milind

    2014-01-01

    Recent advances in translational research in and technology for confocal microscopy of skin cancers, toward clinical applications, are described. Advances in translational research are in diagnosis of melanoma in vivo, pre-operative mapping of lentigo maligna melanoma margins to guide surgery and intra-operative imaging of residual basal cell carcinomas to guide shave-biopsy. Advances in technology include mosaicing microscopy for detection of basal cell carcinomas in large areas of excised tissue, toward rapid pathology-at-the-bedside, and development of small, simple and low-cost line-scanning confocal microscopes for worldwide use in diverse primary healthcare settings. Current limitations and future opportunities and challenges for both clinicians and technologists are discussed. PMID:19964286

  3. Measurements validating the confocal scanning laser holography microscope.

    PubMed

    Jacquemin, Peter B; Herring, Rodney A

    2011-08-01

    A confocal scanning laser holography (CSLH) microscope that uniquely combines the concepts of confocal microscopy with holography has been validated for making nonintrusive, full three-dimensional (3D) intensity and phase measurements of objects from a single viewpoint of observation without loss of object information. The phase measurements have been used to determine the 3D refractive indices of a point source heated silicone oil. The refractive indices are converted to 3D temperature measurements, which are useful for heat transfer studies. An important feature of CSLH is its nonintrusive 3D scanning method, which enables its application to the study of Marangoni convection in microgravity with minimal operational vibrations affecting the motion of fluid in the specimen. PMID:21749743

  4. Hemispherical confocal imaging using turtleback reflector

    E-print Network

    Mukaigawa, Yasuhiro

    We propose a new imaging method called hemispherical confocal imaging to clearly visualize a particular depth in a 3-D scene. The key optical component is a turtleback reflector which is a specially designed polyhedral ...

  5. Confocal unstable-resonator semiconductor laser

    NASA Technical Reports Server (NTRS)

    Salzman, J.; Lang, R.; Yariv, A.; Larson, A.

    1986-01-01

    GaAs/GaAlAs heterostructure lasers with a monolithic confocal unstable resonator were demonstrated. The curved mirrors satisfying the confocal condition were fabricated by etching. Close to threshold, the lasers operate in a single lateral mode with a nearly collimated output beam. A single-lobe far-field intensity distribution as narrow as 1.9-deg full width at half maximum was measured.

  6. Confocal Raman Microspectroscopy of Oral Streptococci

    NASA Astrophysics Data System (ADS)

    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 capabilities of our species identification model. The work included in this thesis has been focused on the study of S. sanguinis and S. mutans, though the principles could easily be applied to the study of other biofilms.

  7. Confocal photothermal flow cytometry in vivo

    NASA Astrophysics Data System (ADS)

    Zharov, Vladimir P.; Galanzha, Ekaterina I.; Ferguson, Scott; Tuchin, Valery V.

    2005-04-01

    The new experimental design of an integrated flow cytometry (FC) is presented, combining high-resolution transmission digital microscopy (TDM) with photothermal (PT), photoacoustic (PA), and fluorescence techniques. We used phantom in vitro to verify this concept with moving living cells, and micro- and nanoparticles. The transistion in vivo study was realized by using unique rat mesentery model for real-time detection of circulating red and white blood cells. The adaptation of confocal schematics to PT microscopy to provide 3-D measurement is discussed. We demonstrated that simulataneous transmission, PT and fluorescent imaging provide the basis for nanodiagnostics and nanotherpeutics in vivo with gold nanoparticles as PT probes and sensitizers as well as identification cells with specific absorbing endogenous and exogenous structures. First attempt to use in parallel PA methods with detection PA signals from single live cells are presented. Potential applications of integrated FC are discussed, including identification of selected cells with different natural absorptive properties, characterization of bioflow (e.g., velocity profile), and PT nanotherapeutics and nanodiagnostics of metastatic cells with gold nanoparticles.

  8. Application of the Empirical Mode Decomposition to Seismic Reflection and Ground Penetrating Radar Data

    NASA Astrophysics Data System (ADS)

    Battista, B. M.; Addison, A.; Knapp, C.; McGee, T.

    2006-12-01

    Advancements in signal processing may allow for improved imaging and analysis of complex geologic targets found in seismic reflection and ground penetrating radar data (GPR). A recent contribution to signal processing is the Empirical Mode Decomposition (EMD). The EMD empirically reduces a time series to several sub- signals whose sum yield the original time series. The benefit of such a process is to empirically develop signal-dependent, time-variant filters in the time domain. The objective of this work is to determine whether the EMD allows for empirically derived characteristics to be used in filter design and application, resulting in better filter performance and enhanced signal-to-noise ratio. Two data sets are used to show successful application of the EMD to geophysical data. Nonlinear cable strum is removed from one data set while the other is used to remove WOW noise from GPR data. Comparison to traditional techniques demonstrates the effectiveness of the technique.

  9. Ultrafast superresolution fluorescence imaging with spinning disk confocal microscope optics

    PubMed Central

    Hayashi, Shinichi; Okada, Yasushi

    2015-01-01

    Most current superresolution (SR) microscope techniques surpass the diffraction limit at the expense of temporal resolution, compromising their applications to live-cell imaging. Here we describe a new SR fluorescence microscope based on confocal microscope optics, which we name the spinning disk superresolution microscope (SDSRM). Theoretically, the SDSRM is equivalent to a structured illumination microscope (SIM) and achieves a spatial resolution of 120 nm, double that of the diffraction limit of wide-field fluorescence microscopy. However, the SDSRM is 10 times faster than a conventional SIM because SR signals are recovered by optical demodulation through the stripe pattern of the disk. Therefore a single SR image requires only a single averaged image through the rotating disk. On the basis of this theory, we modified a commercial spinning disk confocal microscope. The improved resolution around 120 nm was confirmed with biological samples. The rapid dynamics of micro­tubules, mitochondria, lysosomes, and endosomes were observed with temporal resolutions of 30–100 frames/s. Because our method requires only small optical modifications, it will enable an easy upgrade from an existing spinning disk confocal to a SR microscope for live-cell imaging. PMID:25717185

  10. Confocal acoustic radiation force optical coherence elastography using a ring ultrasonic transducer

    SciTech Connect

    Qi, Wenjuan; Li, Rui; Ma, Teng; Kirk Shung, K.; Zhou, Qifa; Chen, Zhongping

    2014-03-24

    We designed and developed a confocal acoustic radiation force optical coherence elastography system. A ring ultrasound transducer was used to achieve reflection mode excitation and generate an oscillating acoustic radiation force in order to generate displacements within the tissue, which were detected using the phase-resolved optical coherence elastography method. Both phantom and human tissue tests indicate that this system is able to sense the stiffness difference of samples and quantitatively map the elastic property of materials. Our confocal setup promises a great potential for point by point elastic imaging in vivo and differentiation of diseased tissues from normal tissue.

  11. Computer assisted design reflection : a web application to improve early stage product in startup companies

    E-print Network

    Gimenez, Clayton C. (Clayton Christopher)

    2014-01-01

    This thesis investigates the concept of computer-assisted design reflection. The work details the development of a prototype framework and reflection engine. Reflection is a critical process in design. It allows a designer ...

  12. Multi-spectral confocal microendoscope for in-vivo imaging

    NASA Astrophysics Data System (ADS)

    Rouse, Andrew Robert

    The concept of in-vivo multi-spectral confocal microscopy is introduced. A slit-scanning multi-spectral confocal microendoscope (MCME) was built to demonstrate the technique. The MCME employs a flexible fiber-optic catheter coupled to a custom built slit-scan confocal microscope fitted with a custom built imaging spectrometer. The catheter consists of a fiber-optic imaging bundle linked to a miniature objective and focus assembly. The design and performance of the miniature objective and focus assembly are discussed. The 3mm diameter catheter may be used on its own or routed though the instrument channel of a commercial endoscope. The confocal nature of the system provides optical sectioning with 3mum lateral resolution and 30mum axial resolution. The prism based multi-spectral detection assembly is typically configured to collect 30 spectral samples over the visible chromatic range. The spectral sampling rate varies from 4nm/pixel at 490nm to 8nm/pixel at 660nm and the minimum resolvable wavelength difference varies from 7nm to 18nm over the same spectral range. Each of these characteristics are primarily dictated by the dispersive power of the prism. The MCME is designed to examine cellular structures during optical biopsy and to exploit the diagnostic information contained within the spectral domain. The primary applications for the system include diagnosis of disease in the gastro-intestinal tract and female reproductive system. Recent data from the grayscale imaging mode are presented. Preliminary multi-spectral results from phantoms, cell cultures, and excised human tissue are presented to demonstrate the potential of in-vivo multi-spectral imaging.

  13. ARES: a new reflective/emissive imaging spectrometer for terrestrial applications

    NASA Astrophysics Data System (ADS)

    Mueller, Andreas; Richter, Rolf; Habermeyer, Martin; Mehl, Harald; Dech, Stefan; Kaufmann, Hermann J.; Segl, Karl; Strobl, Peter; Haschberger, Peter; Bamler, Richard

    2004-10-01

    Airborne imaging spectrometers have a history of about 20 years starting with the operation of AIS in 1982. During the following years, many other instruments were built and successfully operated, e.g., AVIRIS, CASI, DAIS-7915, and HyMap. Since imaging spectrometers cover a spectral region with a large number of narrow contiguous bands they are able to retrieve the spectral reflectance signature of the earth allowing tasks such as mineral identification and abundance mapping, monitoring of vegetation properties, and assessment of water constituents. An essential prerequisite for the evaluation of imaging spectrometer data is a stable spectral and radiometric calibration. Although a considerable progress has been achieved in this respect over the last two decades, this issue is still technically challenging today, especially for low-to-medium cost instruments. This paper introduces a new airborne imaging spectrometer, the ARES (Airborne Reflective Emissive Spectrometer) to be built by Integrated Spectronics, Sydney, Australia, and co-financed by DLR German Aerospace Center and the GFZ GeoResearch Center Potsdam, Germany. The instrument shall feature a high performance over the entire optical wavelength range and will be available to the scientific community from 2006 on. The ARES sensor will provide 150 channels in the solar reflective region (0.47-2.42 ?m) and the thermal region (8.1-12.1 ?m). It will consist of two co-registered optical systems for the reflective and thermal part of the spectrum. The spectral resolution is intended to be between 12 and 16 nm in the solar wavelength range and should reach 150 nm in the thermal range. ARES will be used mainly for environmental applications in terrestrial ecosystems. The thematic focus is thought to be on soil sciences, geology, agriculture and forestry. Limnologic applications should be possible but will not play a key role in the thematic applications. For all above mentioned key application scenarios, the spectral response of soils, rocks, and vegetation as well as their mixtures contain the valuable information to be extracted and quantified. The radiometric requirements for the instrument have been modeled based on realistic application scenarios and account for the most demanding requirements of the three application fields: a spectral bandwidth of 16 nm in the 0.47-1.8 ?m region, and 12 nm in the 2.02 - 2.42 ?m region. The required noise equivalent radiance is 0.05, 0.03, and 0.02 Wm-2sr-1?m-1 for the spectral regions 0.47- 0.89 ?m, 0.89 - 1.8 ?m, and 2.02 - 2.42 ?m, respectively. In the thermal region similar simulations have been carried out. Results suggest a required noise equivalent temperature of 0.05 K for the retrieval of emissivity spectra in the desired accuracy. Nevertheless, due to system restrictions these requirements might have to be reduced to 0.1 K in the wavelength range between 8.1 and 10 ?m and 0.1-0.2 K from 10 to 12.1 ?m.

  14. Multidepth imaging by chromatic dispersion confocal microscopy

    NASA Astrophysics Data System (ADS)

    Olsovsky, Cory A.; Shelton, Ryan L.; Saldua, Meagan A.; Carrasco-Zevallos, Oscar; Applegate, Brian E.; Maitland, Kristen C.

    2012-03-01

    Confocal microscopy has shown potential as an imaging technique to detect precancer. Imaging cellular features throughout the depth of epithelial tissue may provide useful information for diagnosis. However, the current in vivo axial scanning techniques for confocal microscopy are cumbersome, time-consuming, and restrictive when attempting to reconstruct volumetric images acquired in breathing patients. Chromatic dispersion confocal microscopy (CDCM) exploits severe longitudinal chromatic aberration in the system to axially disperse light from a broadband source and, ultimately, spectrally encode high resolution images along the depth of the object. Hyperchromat lenses are designed to have severe and linear longitudinal chromatic aberration, but have not yet been used in confocal microscopy. We use a hyperchromat lens in a stage scanning confocal microscope to demonstrate the capability to simultaneously capture information at multiple depths without mechanical scanning. A photonic crystal fiber pumped with a 830nm wavelength Ti:Sapphire laser was used as a supercontinuum source, and a spectrometer was used as the detector. The chromatic aberration and magnification in the system give a focal shift of 140?m after the objective lens and an axial resolution of 5.2-7.6?m over the wavelength range from 585nm to 830nm. A 400x400x140?m3 volume of pig cheek epithelium was imaged in a single X-Y scan. Nuclei can be seen at several depths within the epithelium. The capability of this technique to achieve simultaneous high resolution confocal imaging at multiple depths may reduce imaging time and motion artifacts and enable volumetric reconstruction of in vivo confocal images of the epithelium.

  15. Performance of "Moth Eye" Anti-Reflective Coatings for Solar Cell Applications

    SciTech Connect

    Clark, E.; Kane, M.; Jiang, P.

    2011-03-14

    An inexpensive, effective anti-reflective coating (ARC) has been developed at the University of Florida to significantly enhance the absorption of light by silicon in solar cells. This coating has nano-scale features, and its microstructure mimics that of various night active insects (e.g. a moth's eye). It is a square array of pillars, each about 700 nm high and having a diameter of about 300 nm. Samples of silicon having this coating were exposed either to various combinations of either elevated temperature and humidity or to gamma irradiation ({sup 60}Co) at the Savannah River National Laboratory, or to a broad spectrum ultraviolet light and to a 532 nm laser light at the University of Florida. The anti-reflective properties of the coatings were unaffected by any of these environmental stresses, and the microstructure of the coating was also unaffected. In fact, the reflectivity of the gamma irradiated ARC became lower (advantageous for solar cell applications) at wavelengths between 400 and 1000 nm. These results show that this coating is robust and should be tested in actual systems exposed to either weather or a space environment. Structural details of the ARCs were studied to optimize their performance. Square arrays performed better than hexagonal arrays - the natural moth-eye coating is indeed a square array. The optimal depth of the templated nanopillars in the ARC was investigated. A wet etching technology for ARC formation was developed that would be less expensive and much faster than dry etching. Theoretical modeling revealed that dimple arrays should perform better than nipple arrays. A method of fabricating both dimple and nipple arrays having the same length was developed, and the dimple arrays performed better than the nipple arrays, in agreement with the modeling. The commercial viability of the technology is quite feasible, since the technology is scalable and inexpensive. This technology is also compatible with current industrial fabrication of solar cells.

  16. Confocal microlaparoscope for imaging the fallopian tube

    PubMed Central

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

    2014-01-01

    Abstract. 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. PMID:25411899

  17. Confocal microlaparoscope for imaging the fallopian tube.

    PubMed

    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. PMID:25411899

  18. Algorithm for automated selection of application-specific fiber-optic reflectance probes.

    PubMed

    Gomes, Andrew J; Backman, Vadim

    2013-02-01

    Several optical techniques and fiber-optic probe systems have been designed to measure the optical properties of tissue. While a wide range of options is often beneficial, it poses a problem to investigators selecting which method to use for their biomedical application of interest. We present a methodology to optimally select a probe that matches the application requirements. Our method is based both on matching a probe's mean sampling depth with the optimal diagnostic depth of the clinical application and on choosing a probe whose interrogation depth and path length is the least sensitive to alterations in the target medium's optical properties. Satisfying these requirements ensures that the selected probe consistently assesses the relevant tissue volume with minimum variability. To aid in probe selection, we have developed a publicly available graphical user interface that takes the desired sampling depth and optical properties of the medium as its inputs and automatically ranks different techniques in their ability to robustly target the desired depth. Techniques investigated include single fiber spectroscopy, differential path length spectroscopy, polarization-gating, elastic light scattering spectroscopy, and diffuse reflectance. The software has been applied to biological case studies. PMID:23455876

  19. Multiple-reflection time-of-flight mass spectrometry for in situ applications

    NASA Astrophysics Data System (ADS)

    Dickel, T.; Plaß, W. R.; Lang, J.; Ebert, J.; Geissel, H.; Haettner, E.; Jesch, C.; Lippert, W.; Petrick, M.; Scheidenberger, C.; Yavor, M. I.

    2013-12-01

    Multiple-reflection time-of-flight mass spectrometers (MR-TOF-MS) have recently been installed at different low-energy radioactive ion beam facilities. They are used as isobar separators with high ion capacity and as mass spectrometers with high mass resolving power and accuracy for short-lived nuclei. Furthermore, MR-TOF-MS have a huge potential for applications in other fields, such as chemistry, biology, medicine, space science, and homeland security. The development, commissioning and results of an MR-TOF-MS is presented, which serves as proof-of-principle to show that very high mass resolving powers (?105) can be achieved in a compact device (length ?30 cm). Based on this work, an MR-TOF-MS for in situ application has been designed. For the first time, this device combines very high mass resolving power (>105), mobility, and an atmospheric pressure inlet in one instrument. It will enable in situ measurements without sample preparation at very high mass accuracy. Envisaged applications of this mobile MR-TOF-MS are discussed.

  20. Mapping of dendritic lesions in patients with herpes simplex keratitis using in vivo confocal microscopy

    PubMed Central

    Yokogawa, Hideaki; Kobayashi, Akira; Mori, Natsuko; Sugiyama, Kazuhisa

    2015-01-01

    Purpose To produce a two-dimensional reconstruction map of dendritic lesions in patients with herpes simplex keratitis (HSK) using in vivo confocal microscopy. Methods Four eyes of four patients (mean 65.8 years) with HSK presenting with a dendritic lesion were enrolled. Slit-lamp biomicroscopy and in vivo laser confocal microscopy were performed. Acquired confocal images at the level of the epithelium were arranged and mapped into subconfluent montages. Changes in the shape and degree of light reflection of abnormal cells and deposits around dendritic lesions as well as other corneal layers were qualitatively evaluated. Results Mapping of dendritic lesion was successful in all cases, and the subconfluent montages clearly showed the larger image of dendritic lesion. In all cases, the dendritic lesion consisted of hyperreflective irregular epithelial cells, and was surrounded by distorted and elongated epithelial cells. In three cases, hyperreflective deposits were noted at the midline of the lesion. The corneal stroma showed a hyperreflective honeycomb pattern. In two cases, inflammatory cells were observed at the level of endothelial cell layer. Conclusion Mapping of dendritic lesions in patients with HSK was successful in all patients using in vivo confocal microscopy. Cellular level observation of dendritic lesion at a relatively larger magnification may help understand the in vivo morphological change of HSK. Further study in more patients with HSK and nonherpetic dendritic lesion is needed to utilize confocal microscopy images in differential diagnosis and follow-up of the epithelial lesions with dendrite. PMID:26445524

  1. Application of Neutron Reflectivity for Studies of Biomolecular Structures and Functions at Interfaces

    SciTech Connect

    Johs, Alexander; Liang, Liyuan; Gu, Baohua; Ankner, John Francis; Wang, Wei

    2009-01-01

    Structures and functions of cell membranes are of central importance in understanding processes such as cell signaling, chemotaxis, redox transformation, biofilm formation, and mineralization occurring at interfaces. This chapter provides an overview of the application of neutron reflectivity (NR) as a unique tool for probing biomolecular structures and mechanisms as a first step toward understanding protein protein, protein lipid, and protein mineral interactions at the membrane substrate interfaces. Emphasis is given to the review of existing literature on the assembly of biomimetic membrane systems, such as supported membranes for NR studies, and demonstration of model calculations showing the potential of NR to elucidate molecular fundamentals of microbial cell mineral interactions and structure functional relationships of electron transport pathways. The increased neutron flux afforded by current and upcoming neutron sources holds promise for elucidating detailed processes such as phase separation, formation of microdomains, and membrane interactions with proteins and peptides in biological systems.

  2. [Applications of near infrared reflectance spectroscopy technique to determination of forage mycotoxins].

    PubMed

    Xu, Qing-Fang; Han, Jian-Guo; Yu, Zhu; Yue, Wen-Bin

    2010-05-01

    The near infrared reflectance spectroscopy technique (NIRS) has been explored at many fields such as agriculture, food, chemical, medicine, and so on, due to its rapid, effective, non-destructive, and on-line characteristics. Fungi invasion in forage materials during processing and storage would generate mycotoxins, which were harmful for people and animal through food chains. The determination of mycotoxins included the overelaborated pretreatments such as milling, extracting, chromatography and subsequent process such as enzyme linked immunosorbent assay, high performance liquid chromatography, and thin layer chromatography. The authors hope that high precision and low detection limit spectrum instrument, and software technology and calibration model of mycotoxins determination, will fast measure accurately the quality and quantity of mycotoxins, which will provide basis for reasonable process and utilization of forage and promote the application of NIRS in the safety livestock product. PMID:20672610

  3. Power and limits of laser scanning confocal microscopy.

    PubMed

    Laurent, M; Johannin, G; Gilbert, N; Lucas, L; Cassio, D; Petit, P X; Fleury, A

    1994-01-01

    In confocal microscopy, the object is illuminated and observed so as to rid the resulting image of the light from out-of-focus planes. Imaging may be performed in the reflective or in the fluorescence mode. Confocal microscopy allows accurate and non-destructive optical sectioning in a plane perpendicular or parallel to the optical axis of the microscope. Further digital three-dimensional treatments of the data may be performed so as to visualize the specimen from a variety of angles. Several examples illustrating each of these possibilities are given. Three-dimensional reconstitution of nuclear components using a cubic representation and a ray-tracing based method are also given. Instrumental and experimental factors can introduce some bias into the acquisition of the 3-D data set: self-shadowing effects of thick specimens, spherical aberrations due to the sub-optimum use of the objective lenses and photo-bleaching processes. This last phenomenon is the one that most heavily hampers the quantitative analysis needed for a 3-D reconstruction. We delineate each of these problems and indicate to what extent they can be solved. Some tips are given for the practice of confocal microscope and image recovery: how to determine empirically the thickness of the optical slices, how to deal with extreme contrasts in an image, how to prevent artificial flattening of the specimens. Finally, future prospects in the field are outlined. Particular mention of the use of pulsed lasers is made as they may be an alternative to UV-lasers and a possible means to attenuate photodamage to biological specimens. PMID:8087072

  4. Confocal multiview light-sheet microscopy

    PubMed Central

    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

  5. Laser differential confocal radius measurement system.

    PubMed

    Sun, Ruoduan; Qiu, Lirong; Yang, Jiamiao; Zhao, Weiqian

    2012-09-10

    A laser differential confocal radius measurement system with high measurement accuracy is developed for optical manufacturing and metrology. The system uses the zero-crossing point of the differential confocal intensity curve to precisely identify the cat's-eye and confocal positions and uses an interferometer to measure the distance between these two positions, thereby achieving a high-precision measurement for the radius of curvature. The coaxial measuring optical path reduces the Abbe error, and the air-bearing slider reduces the motion error. The error analysis indicates the theoretical accuracy of the system is up to 2 ppm, and the experiment shows that the system has high focusing sensitivity and is little affected by environmental fluctuations; the measuring repeatability is between 4 and 12 ppm. PMID:22968263

  6. Confocal multiview light-sheet microscopy.

    PubMed

    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

  7. Atherosclerotic plaque detection by confocal Brillouin and Raman microscopies

    NASA Astrophysics Data System (ADS)

    Meng, Zhaokai; Basagaoglu, Berkay; Yakovlev, Vladislav V.

    2015-02-01

    Atherosclerosis, the development of intraluminal plaque, is a fundamental pathology of cardiovascular system and remains the leading cause of morbidity and mortality worldwide. Biomechanical in nature, plaque rupture occurs when the mechanical properties of the plaque, related to the morphology and viscoelastic properties, are compromised, resulting in intraluminal thrombosis and reduction of coronary blood flow. In this report, we describe the first simultaneous application of confocal Brillouin and Raman microscopies to ex-vivo aortic wall samples. Such a non-invasive, high specific approach allows revealing a direct relationship between the biochemical and mechanical properties of atherosclerotic tissue.

  8. Confocal Microscopy for Modeling Electron Microbeam Irradiation of Skin

    SciTech Connect

    Miller, John H.; Chrisler, William B.; Wang, Xihai; Sowa, Marianne B.

    2011-08-01

    For radiation exposures employing targeted sources such as particle microbeams, the deposition of energy and dose will depend on the spatial heterogeneity of the spample. Although cell structural variations are relatively minor for two-dimensional cell cultures, they can vary significantly for fully differential tissues. Employing high-resolution confocal microscopy, we have determined the spatial distribution, size, and shape of epidermal kerantinocyte nuclei for the full-thickness EpiDerm skin model (MatTek, Ashland, VA). Application of these data to claculate the microdosimetry and microdistribution of energy deposition by an electron microbeam is discussed.

  9. Applicability of a Diffuse Reflectance Infrared Fourier Transform handheld spectrometer to perform in situ analyses on Cultural Heritage materials

    NASA Astrophysics Data System (ADS)

    Arrizabalaga, Iker; Gómez-Laserna, Olivia; Aramendia, Julene; Arana, Gorka; Madariaga, Juan Manuel

    2014-08-01

    This work studies the applicability of a Diffuse Reflectance Infrared Fourier Transform handheld device to perform in situ analyses on Cultural Heritage assets. This portable diffuse reflectance spectrometer has been used to characterise and diagnose the conservation state of (a) building materials of the Guevara Palace (15th century, Segura, Basque Country, Spain) and (b) different 19th century wallpapers manufactured by the Santa Isabel factory (Vitoria-Gasteiz, Basque Country, Spain) and by the well known Dufour and Leroy manufacturers (Paris, France), all of them belonging to the Torre de los Varona Castle (Villanañe, Basque Country, Spain). In all cases, in situ measurements were carried out and also a few samples were collected and measured in the laboratory by diffuse reflectance spectroscopy (DRIFT) in order to validate the information obtained by the handheld instrument. In the analyses performed in situ, distortions in the diffuse reflectance spectra can be observed due to the presence of specular reflection, showing the inverted bands caused by the Reststrahlen effect, in particular on those IR bands with the highest absorption coefficients. This paper concludes that the results obtained in situ by a diffuse reflectance handheld device are comparable to those obtained with laboratory diffuse reflectance spectroscopy equipment and proposes a few guidelines to acquire good spectra in the field, minimising the influence caused by the specular reflection.

  10. Applicability of a Diffuse Reflectance Infrared Fourier Transform handheld spectrometer to perform in situ analyses on Cultural Heritage materials.

    PubMed

    Arrizabalaga, Iker; Gómez-Laserna, Olivia; Aramendia, Julene; Arana, Gorka; Madariaga, Juan Manuel

    2014-08-14

    This work studies the applicability of a Diffuse Reflectance Infrared Fourier Transform handheld device to perform in situ analyses on Cultural Heritage assets. This portable diffuse reflectance spectrometer has been used to characterise and diagnose the conservation state of (a) building materials of the Guevara Palace (15th century, Segura, Basque Country, Spain) and (b) different 19th century wallpapers manufactured by the Santa Isabel factory (Vitoria-Gasteiz, Basque Country, Spain) and by the well known Dufour and Leroy manufacturers (Paris, France), all of them belonging to the Torre de los Varona Castle (Villanañe, Basque Country, Spain). In all cases, in situ measurements were carried out and also a few samples were collected and measured in the laboratory by diffuse reflectance spectroscopy (DRIFT) in order to validate the information obtained by the handheld instrument. In the analyses performed in situ, distortions in the diffuse reflectance spectra can be observed due to the presence of specular reflection, showing the inverted bands caused by the Reststrahlen effect, in particular on those IR bands with the highest absorption coefficients. This paper concludes that the results obtained in situ by a diffuse reflectance handheld device are comparable to those obtained with laboratory diffuse reflectance spectroscopy equipment and proposes a few guidelines to acquire good spectra in the field, minimising the influence caused by the specular reflection. PMID:24747846

  11. Imaging intracellular protein dynamics by spinning disk confocal microscopy

    PubMed Central

    Stehbens, Samantha; Pemble, Hayley; Murrow, Lindsay; Wittmann, Torsten

    2012-01-01

    The palette of fluorescent proteins has grown exponentially over the last decade, and as a result live imaging of cells expressing fluorescently tagged proteins is becoming more and more main stream. Spinning disk confocal microscopy (SDC) is a high speed optical sectioning technique, and a method of choice to observe and analyze intracellular fluorescent protein dynamics at high spatial and temporal resolution. In an SDC system, a rapidly rotating pinhole disk generates thousands of points of light that scan the specimen simultaneously, which allows direct capture of the confocal image with low noise scientific grade cooled charged-coupled device (CCD) cameras, and can achieve frame rates of up 1000 frames per second. In this chapter we describe important components of a state-of-the-art spinning disk system optimized for live cell microscopy, and provide a rationale for specific design choices. We also give guidelines how other imaging techniques such as total internal reflection (TIRF) microscopy or spatially controlled photoactivation can be coupled with SDC imaging, and provide a short protocol on how to generate cell lines stably expressing fluorescently tagged proteins by lentivirus-mediated transduction. PMID:22264541

  12. Miniature objective lens with variable focus for confocal endomicroscopy

    PubMed Central

    Kim, Minkyu; Kang, DongKyun; Wu, Tao; Tabatabaei, Nima; Carruth, Robert W.; Martinez, Ramses V; Whitesides, George M.; Nakajima, Yoshikazu; Tearney, Guillermo J.

    2014-01-01

    Spectrally encoded confocal microscopy (SECM) is a reflectance confocal microscopy technology that can rapidly image large areas of luminal organs at microscopic resolution. One of the main challenges for large-area SECM imaging in vivo is maintaining the same imaging depth within the tissue when patient motion and tissue surface irregularity are present. In this paper, we report the development of a miniature vari-focal objective lens that can be used in an SECM endoscopic probe to conduct adaptive focusing and to maintain the same imaging depth during in vivo imaging. The vari-focal objective lens is composed of an aspheric singlet with an NA of 0.5, a miniature water chamber, and a thin elastic membrane. The water volume within the chamber was changed to control curvature of the elastic membrane, which subsequently altered the position of the SECM focus. The vari-focal objective lens has a diameter of 5 mm and thickness of 4 mm. A vari-focal range of 240 ?m was achieved while maintaining lateral resolution better than 2.6 ?m and axial resolution better than 26 ?m. Volumetric SECM images of swine esophageal tissues were obtained over the vari-focal range of 260 ?m. SECM images clearly visualized cellular features of the swine esophagus at all focal depths, including basal cell nuclei, papillae, and lamina propria. PMID:25574443

  13. Light localization properties of biological cells via confocal imaging

    NASA Astrophysics Data System (ADS)

    Sahay, Peeyush; Ghimire, Hemendra M.; Almabadi, Huda; Pradhan, Prabhakar

    2015-03-01

    Detection and characterization of the spatial refractive index fluctuations of very weakly disordered optical dielectric media has ample applications in various fields ranging from soft condensed matter to biological research. We report a study of the submicron scale degree of the structural disorder of heterogeneous weakly disordered optical dielectric media, such as biological cells, by quantifying their submicron scale light-localization properties. Confocal microscopy is used to construct disordered optical lattices of these dielectric media. Light-localization properties are studied by the statistical analysis of the inverse participation ratio (IPR) of the localized eigenfunctions of these optical lattices at the submicron scales. The method is described and its importance is highlighted. As one of the applications, we demonstrate that using this method, different types of normal and cancerous cells can be distinguished by quantifying the structural disorder inside the cells via their confocal micrographs. Other potential applications of the technique to characterize weakly disordered media, as well as biological cells, in particular cancer detection, are also discussed. NIH and University of Memphis.

  14. Assessing the tissue-imaging performance of confocal microscope architectures via Monte Carlo simulations.

    PubMed

    Chen, Ye; Wang, Danni; Liu, Jonathan T C

    2012-11-01

    Various confocal microscope architectures have been developed for in vivo tissue imaging, including single-axis confocal (SAC) and dual-axis confocal (DAC) configurations utilizing both point-scanning (PS) and line-scanning (LS) approaches. While it is known that these design variations lead to tradeoffs in imaging performance, a quantitative comparison of the imaging performance of these configurations in highly turbid media would be of value. Here, we perform Monte Carlo simulations to evaluate the optical-sectioning capability of these various confocal microscope architectures in reflectance mode. In particular, we investigate the axial and transverse responses of these configurations to reflective targets at various depths within a homogenous scattering medium. We find that the DAC-PS configuration results in superior rejection of multiply scattered background light compared to all other configurations, followed in performance by the SAC-PS, the DAC-LS, and then the SAC-LS. Line scanning with both the DAC and SAC configurations leads to photon crosstalk between pixels. However, at shallow depths, the axial and transverse resolution of all configurations is maintained in a homogeneous scattering medium. PMID:23114341

  15. Optimization of pupil design for point-scanning and line-scanning confocal microscopy.

    PubMed

    Patel, Yogesh G; Rajadhyaksha, Milind; Dimarzio, Charles A

    2011-08-01

    Both point-scanning and line-scanning confocal microscopes provide resolution and optical sectioning to observe nuclear and cellular detail in human tissues, and are being translated for clinical applications. While traditional point-scanning is truly confocal and offers the best possible optical sectioning and resolution, line-scanning is partially confocal but may offer a relatively simpler and lower-cost alternative for more widespread dissemination into clinical settings. The loss of sectioning and loss of contrast due to scattering in tissue is more rapid and more severe with a line-scan than with a point-scan. However, the sectioning and contrast may be recovered with the use of a divided-pupil. Thus, as part of our efforts to translate confocal microscopy for detection of skin cancer, and to determine the best possible approach for clinical applications, we are now developing a quantitative understanding of imaging performance for a set of scanning and pupil conditions. We report a Fourier-analysis-based computational model of confocal microscopy for six configurations. The six configurations are point-scanning and line-scanning, with full-pupil, half-pupil and divided-pupils. The performance, in terms of on-axis irradiance (signal), resolution and sectioning capabilities, is quantified and compared among these six configurations. PMID:21833360

  16. Optimization of pupil design for point-scanning and line-scanning confocal microscopy

    PubMed Central

    Patel, Yogesh G.; Rajadhyaksha, Milind; DiMarzio, Charles A.

    2011-01-01

    Both point-scanning and line-scanning confocal microscopes provide resolution and optical sectioning to observe nuclear and cellular detail in human tissues, and are being translated for clinical applications. While traditional point-scanning is truly confocal and offers the best possible optical sectioning and resolution, line-scanning is partially confocal but may offer a relatively simpler and lower-cost alternative for more widespread dissemination into clinical settings. The loss of sectioning and loss of contrast due to scattering in tissue is more rapid and more severe with a line-scan than with a point-scan. However, the sectioning and contrast may be recovered with the use of a divided-pupil. Thus, as part of our efforts to translate confocal microscopy for detection of skin cancer, and to determine the best possible approach for clinical applications, we are now developing a quantitative understanding of imaging performance for a set of scanning and pupil conditions. We report a Fourier-analysis-based computational model of confocal microscopy for six configurations. The six configurations are point-scanning and line-scanning, with full-pupil, half-pupil and divided-pupils. The performance, in terms of on-axis irradiance (signal), resolution and sectioning capabilities, is quantified and compared among these six configurations. PMID:21833360

  17. Compositional Computational Reflection

    E-print Network

    Malecha, Gregory

    2014-01-01

    Current work on computational reflection is single-minded; each reflective procedure is written with a specific application or scope in mind. Composition of these reflective procedures is done by a proof- generating tactic ...

  18. Group refractive index reconstruction with broadband interferometric confocal microscopy

    E-print Network

    Boppart, Stephen

    Group refractive index reconstruction with broadband interferometric confocal microscopy Daniel L scale. The technique utilizes a broadband confocal microscope embedded into a Mach reconstruction on a cellular phan- tom. The spatial refractive index distribution determines the behavior of many

  19. CONFOCAL MICROSCOPY SYSTEM PERFORMANCE: AXIAL RESOLUTION

    EPA Science Inventory

    Abstract

    Confocal Microscopy System Performance: Axial resolution.
    Robert M. Zucker, PhD

    Reproductive Toxicology Division, National Health and Environmental Effects Research Laboratory, Office of Research and Development, U.S. Environmental Protection Agency, Re...

  20. Confocal microscopy imaging of solid tissue

    EPA Science Inventory

    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 ...

  1. Image inpainting for the differential confocal microscope

    NASA Astrophysics Data System (ADS)

    Qiu, Lirong; Wang, Lei; Liu, Dali; Hou, Maosheng; Zhao, Weiqian

    2015-02-01

    In the process of zero-crossing trigger measurement of differential confocal microscope, the sample surface features or tilt will cause the edges can't be triggered. Meanwhile, environment vibration can also cause false triggering. In order to restore the invalid information of sample, and realize high-precision surface topography measurement, Total Variation (TV) inpainting model is applied to restore the scanning images. Emulation analysis and experimental verification of this method are investigated. The image inpainting algorithm based on TV model solves the minimization of the energy equation by calculus of variations, and it can effectively restore the non-textured image with noises. Using this algorithm, the simulation confocal laser intensity curve and height curve of standard step sample are restored. After inpainting the intensity curve below the threshold is repaired, the maximum deviation from ideal situation is 0.0042, the corresponding edge contour of height curve is restored, the maximum deviation is 0.1920, which proves the algorithm is effective. Experiment of grating inpainting indicates that the TV algorithm can restore the lost information caused by failed triggering and eliminate the noise caused by false triggering in zero-crossing trigger measurement of differential confocal microscope. The restored image is consistent with the scanning result of OLYMPUS confocal microscope, which can satisfy the request of follow-up measurement analysis.

  2. Vibrometry using a chromatic confocal sensor

    NASA Astrophysics Data System (ADS)

    Berkovic, G.; Zilberman, S.; Shafir, E.; Cohen-Sabban, J.

    2014-05-01

    We demonstrate vibrometry using a chromatic confocal sensor which measures displacements with 0.1 ?m resolution at a rate of 10 kHz. This technique was used to study the vibration of a musical tuning fork with a resonance at 523 Hz. Other examples presented include vibration of water waves and multiple point vibrometry of a vibrating steel rod.

  3. CONFOCAL MICROSCOPY SYSTEM PERFORMANCE: LASER POWER MEASUREMENTS

    EPA Science Inventory

    Laser power abstract
    The reliability of the confocal laser-scanning microscope (CLSM) to obtain intensity measurements and quantify fluorescence data is dependent on using a correctly aligned machine that contains a stable laser power. The laser power test appears to be one ...

  4. Anti-confocal versus confocal assessment of the middle ear simulated by Monte Carlo methods

    PubMed Central

    Jung, David S.; Crowe, John A.; Birchall, John P.; Somekh, Michael G.; See, Chung W.

    2015-01-01

    The ability to monitor the inflammatory state of the middle ear mucosa would provide clinical utility. To enable spectral measurements on the mucosa whilst rejecting background signal from the eardrum an anti-confocal system is investigated. In contrast to the central pinhole in a confocal system the anti-confocal system uses a central stop to reject light from the in-focus plane, the eardrum, with all other light detected. Monte Carlo simulations of this system show an increase in detected signal and improved signal-to-background ratio compared to a conventional confocal set-up used to image the middle ear mucosa. System parameters are varied in the simulation and their influence on the level of background rejection are presented. PMID:26504633

  5. Application of a wide-field phantom eye for optical coherence tomography and reflectance imaging

    PubMed Central

    Corcoran, Anthony; Muyo, Gonzalo; van Hemert, Jano; Gorman, Alistair; Harvey, Andrew R.

    2015-01-01

    Optical coherence tomography (OCT) and reflectance imaging are used in clinical practice to measure the thickness and transverse dimensions of retinal features. The recent trend towards increasing the field of view (FOV) of these devices has led to an increasing significance of the optical aberrations of both the human eye and the device. We report the design, manufacture and application of the first phantom eye that reproduces the off-axis optical characteristics of the human eye, and allows the performance assessment of wide-field ophthalmic devices. We base our design and manufacture on the wide-field schematic eye, [Navarro, R. J. Opt. Soc. Am. A, 1985, 2.] as an accurate proxy to the human eye and enable assessment of ophthalmic imaging performance for a ±70? external FOV. We used multi-material 3D-printed retinal targets to assess imaging performance of the following ophthalmic instruments: the Optos 200Tx, Heidelberg Spectralis, Zeiss FF4 fundus camera and Optos OCT SLO and use the phantom to provide an insight into some of the challenges of wide-field OCT.

  6. Application of binocular vision probe on measurement of highly reflective metallic surface

    NASA Astrophysics Data System (ADS)

    Zhang, Hongwei; Zhang, Guoxiong; Shi, Ying; Zhao, Xiaosong

    2005-01-01

    Reverse engineering of free-form surfaces is one of the most challenging technologies in advanced manufacturing. With the development of industry more and more sculptured surfaces, such as molds and turbine blades, are required to measure quickly and accurately. Optical non-contact probes possess many advantages, such as high speed, no measuring force, in comparison with contact ones. The ability of stereo vision probe with CCD cameras in gathering a large amount of information simultaneously makes it the most popularly used one in sculptured surface measurements. So a non-contact measurement system is built which consists of CMM and a vision probe with many techniques. It distinguishes itself by high efficiency, high accuracy and reliability, as well as applicability for on-line measurement of complicated sculptured surfaces. With a virtual 3D target in form of a grid plate, all the intrinsic and extrinsic parameters of CCD camera including the uncertainty of image scale factor and optical center of camera can be readily calibrated. Through measuring cylindrical section and surface of gauge block, this system is viable to measure free-form surface and high-reflective metallic surface.

  7. The application of visible wavelength reflectance hyperspectral imaging for the detection and identification of blood stains.

    PubMed

    Li, Bo; Beveridge, Peter; O'Hare, William T; Islam, Meez

    2014-12-01

    Current methods of detection and identification of blood stains rely largely on visual examination followed by presumptive tests such as Kastle-Meyer, Leuco-malachite green or luminol. Although these tests are useful, they can produce false positives and can also have a negative impact on subsequent DNA tests. A novel application of visible wavelength reflectance hyperspectral imaging has been used for the detection and positive identification of blood stains in a non contact and non destructive manner on a range of coloured substrates. The identification of blood staining was based on the unique visible absorption spectrum of haemoglobin between 400 and 500 nm. Images illustrating successful discrimination of blood stains from nine red substances are included. It has also been possible to distinguish between blood and approximately 40 other reddish stains. The technique was also successfully used to detect latent blood stains deposited on white filter paper at dilutions of up to 1 in 512 folds and on red tissue at dilutions of up to 1 in 32 folds. Finally, in a blind trial, the method successfully detected and identified a total of 9 blood stains on a red T-shirt. PMID:25498930

  8. Probe based confocal laser endomicroscopy of the pancreatobiliary system

    PubMed Central

    Almadi, Majid A; Neumann, Helmut

    2015-01-01

    AIM: To review applications of confocal laser endomicroscopy (CLE) in pancreatobiliary lesions and studies that assessed training and interpretation of images. METHODS: A computerized literature search was performed using OVID MEDLINE, EMBASE, Cochrane library, and the ISI Web of Knowledge from 1980 to October 2014. We also searched abstracts from major meetings that included the Digestive Disease Week, Canadian Digestive Disease Week and the United European Gastroenterology Week using a combination of controlled vocabulary and text words related to pCLE, confocal, endomicroscopy, probe-based confocal laser endomicroscopy, and bile duct to identify reports of trials. In addition, recursive searches and cross-referencing was performed, and manual searches of articles identified after the initial search was also completed. We included fully published articles and those in abstract form. Given the relatively recent introduction of CLE we included randomized trials and cohort studies. RESULTS: In the evaluation of indeterminate pancreatobiliary strictures CLE with ERCP compared to ERCP alone can increase the detection of cancerous strictures with a sensitivity of (98% vs 45%) and has a negative predictive value (97% vs 69%), but decreased the specificity (67% vs 100%) and the positive predictive value (71% vs 100%) when compared to index pathology. Modifications in the classification systems in indeterminate biliary strictures have increased the specificity of pCLE from 67% to 73%. In pancreatic cystic lesions there is a need to develop similar systems to interpret and characterize lesions based on CLE images obtained. The presence of superficial vascular network predicts serous cystadenomas accurately. Also training in acquiring and interpretation of images is feasible in those without any prior knowledge in CLE in a relatively simple manner and computer-aided diagnosis software is a promising innovation. CONCLUSION: The role of pCLE in the evaluation of pancreatobiliary disorders might be better suited for those with an intermediate and low probability. PMID:26640347

  9. In-vivo multi-spectral confocal microscopy

    NASA Astrophysics Data System (ADS)

    Rouse, Andrew R.; Udovich, Joshua A.; Gmitro, Arthur F.

    2005-03-01

    A multi-spectral confocal microendoscope (MCME) for in-vivo imaging has been developed. The MCME employs a flexible fiber-optic catheter coupled to a slit-scan confocal microscope with an imaging spectrometer. The catheter consists of a fiber-optic imaging bundle linked to a miniature objective and focus assembly. The focus mechanism allows for imaging to a maximum tissue depth of 200 microns. The 3mm diameter catheter may be used on its own or routed though the instrument channel of a commercial endoscope. The confocal nature of the system provides optical sectioning with 3 micron lateral resolution and 30 micron axial resolution. The system incorporates two laser sources and is therefore capable of simultaneous acquisition of spectra from multiple dyes using dual excitation. The prism based multi-spectral detection assembly is typically configured to collect 30 spectral samples over the visible range. The spectral sampling rate varies from 4nm/pixel at 490nm to 8nm/pixel at 660nm and the minimum resolvable wavelength difference varies from 8nm to 16nm over the same spectral range. Each of these characteristics are primarily dictated by the dispersion characteristics of the prism. The MCME is designed to examine cellular structures during optical biopsy and to exploit the diagnostic information contained within the spectral domain. The primary applications for the system include diagnosis of disease in the gastro-intestinal tract and female reproductive system. In-vitro, and ex-vivo multi-spectral results are presented.

  10. Optical clearing assisted confocal microscopy of ex vivo transgenic mouse skin

    NASA Astrophysics Data System (ADS)

    Song, Eunjoo; Ahn, YoonJoon; Ahn, Jinhyo; Ahn, Soyeon; Kim, Changhwan; Choi, Sanghoon; Boutilier, Richard Martin; Lee, Yongjoong; Kim, Pilhan; Lee, Ho

    2015-10-01

    We examined the optical clearing assisted confocal microscopy of the transgenic mouse skin. The pinna and dorsal skin were imaged with a confocal microscope after the application of glycerol and FocusClear. In case of the glycerol-treated pinna, the clearing was minimal due to the inefficient permeability. However, the imaging depth was improved when the pinna was treated with FocusClear. In case of dorsal skin, we were able to image deeply to the subcutaneous connective tissue with both agents. Various skin structures such as the vessel, epithelium cells, cartilage, dermal cells, and hair follicles were clearly imaged.

  11. Fibre optic confocal imaging (FOCI) for subsurface microscopy of the colon in vivo.

    PubMed

    Delaney, P M; King, R G; Lambert, J R; Harris, M R

    1994-02-01

    Fibre optic confocal imaging (FOCI) is a new type of microscopy which has been recently developed (Delaney et al. 1993). In contrast to conventional light microscopy, FOCI and other confocal techniques allow clear imaging of subsurface structures within translucent objects. However, unlike conventional confocal microscopes which are bulky (because of a need for accurate alignment of large components) FOCI allows the imaging end to be miniaturised and relatively mobile. FOCI is thus particularly suited for clear subsurface imaging of structures within living animals or subjects. The aim of the present study was to assess the suitability of using FOCI for imaging of subsurface structures within the colon, both in vitro (human and rat biopsies) and in vivo (in rats). Images were obtained in fluorescence mode (excitation 488 nm, detection above 515 nm) following topical application of fluorescein. By this technique the glandular structure of the colon was imaged. FOCI is thus suitable for subsurface imaging of the colon in vivo. PMID:8157487

  12. Design and Demonstration of a Miniature Catheter for a Confocal Microendoscope

    NASA Astrophysics Data System (ADS)

    Rouse, Andrew R.; Kano, Angelique; Udovich, Joshua A.; Kroto, Shona M.; Gmitro, Arthur F.

    2004-11-01

    The fluorescence confocal microendoscope provides high-resolution, in vivo imaging of cellular pathology during optical biopsy. The confocal microendoscope employs a flexible fiber-optic catheter coupled to a custom-built slit-scan confocal microscope. The catheter consists of a fiber-optic imaging bundle linked to a miniature objective and focus assembly. The 3-mm-diameter catheter may be used on its own or routed though the instrument channel of a commercial endoscope, adding microscopic imaging capability to conventional endoscopy. The design and performance of the miniature objective and focus assembly are discussed. Primary applications of the system include diagnosis of disease in the gastrointestinal tract and female reproductive system.

  13. General theory of optical reflection from a thin film on a solid and its application to heteroepitaxy Department of Physics, University of California, Davis, California 95616, USA

    E-print Network

    Zhu, Xiangdong

    General theory of optical reflection from a thin film on a solid and its application manuscript received 3 April 2007; published 27 June 2007 Light reflection from an optically smooth yet of information on morphology and chemical makeup of the film. We show that changes in optical reflectivity for s

  14. Statistical Characterization of Face Spectral Reflectances and Its Application to Human Portraiture Spectral Estimation

    E-print Network

    Fairchild, Mark D.

    reflectance of human skin depends chiefly on the presence of pigment and blood.4, 5 Different complexions by a black pigment called melanin though there are five different pigments in the skin.6 The spectral were applied to spectral reflectances of human facial skin from different sources

  15. Digital confocal microscopy through a multimode fiber

    E-print Network

    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.

  16. Laser differential confocal paraboloidal vertex radius measurement.

    PubMed

    Yang, Jiamiao; Qiu, Lirong; Zhao, Weiqian; Shen, Yang; Jiang, Hongwei

    2014-02-15

    This Letter proposes a laser differential confocal paraboloidal vertex radius measurement (DCPRM) method for the high-accuracy measurement of the paraboloidal vertex radius of curvature. DCPRM constructs an autocollimation vertex radius measurement light path for the paraboloid by placing a reflector in the incidence light path. This technique is based on the principle that a paraboloid can aim a parallel beam at its focus without aberration and uses differential confocal positioning technology to identify the paraboloid focus and vertex accurately. Measurement of the precise distance between these two positions is achieved to determine the paraboloid vertex radius. Preliminary experimental results indicate that DCPRM has a relative expanded uncertainty of less than 0.001%. PMID:24562218

  17. Analysis for Mar Vel Black and acetylene soot low reflectivity surfaces for star tracker sunshade applications

    NASA Technical Reports Server (NTRS)

    Yung, E.

    1974-01-01

    Mar Vel Black is a revolutionary new extremely low reflectivity anodized coating developed by Martin Marietta of Denver. It is of great interest in optics in general, and in star trackers specifically because it can reduce extraneous light reflections. A sample of Mar Vel Black was evaluated. Mar Vel Black looks much like a super black surface with many small peaks and very steep sides so that any light incident upon the surface will tend to reflect many times before exiting that surface. Even a high reflectivity surface would thus appear to have a very low reflectivity under such conditions. Conversely, acetylene soot does not have the magnified surface appearance of a super black surface. Its performance is, however, predictable from the surface structure, considering the known configuration of virtually pure carbon.

  18. Characterization and Application of a Grazing Angle Objective for Quantitative Infrared Reflection Microspectroscopy

    NASA Technical Reports Server (NTRS)

    Pepper, Stephen V.

    1995-01-01

    A grazing angle objective on an infrared microspectrometer is studied for quantitative spectroscopy by considering the angular dependence of the incident intensity within the objective's angular aperture. The assumption that there is no angular dependence is tested by comparing the experimental reflectance of Si and KBr surfaces with the reflectance calculated by integrating the Fresnel reflection coefficient over the angular aperture under this assumption. Good agreement was found, indicating that the specular reflectance of surfaces can straight-forwardly be quantitatively integrated over the angular aperture without considering non-uniform incident intensity. This quantitative approach is applied to the thickness determination of dipcoated Krytox on gold. The infrared optical constants of both materials are known, allowing the integration to be carried out. The thickness obtained is in fair agreement with the value determined by ellipsometry in the visible. Therefore, this paper illustrates a method for more quantitative use of a grazing angle objective for infrared reflectance microspectroscopy.

  19. Materials and corrosion characterization using the confocal resonator

    SciTech Connect

    Tigges, C.P.; Sorensen, N.R.; Hietala, V.M.; Plut, T.A.

    1997-05-01

    Improved characterization and process control is important to many Sandia and DOE programs related to manufacturing. Many processes/structures are currently under-characterized including thin film growth, corrosion and semiconductor structures, such as implant profiles. A sensitive tool is required that is able to provide lateral and vertical imaging of the electromagnetic properties of a sample. The confocal resonator is able to characterize the surface and near-surface impedance of materials. This device may be applied to a broad range of applications including in situ evaluation of thin film processes, physical defect detection/characterization, the characterization of semiconductor devices and corrosion studies. In all of these cases, the technology should work as a real-time process diagnostic or as a feedback mechanism regarding the quality of a manufacturing process. This report summarizes the development and exploration of several diagnostic applications.

  20. In vivo confocal and multiphoton microendoscopy

    PubMed Central

    Kim, Pilhan; Puoris’haag, Mehron; Côté, Daniel; Lin, Charles P.; Yun, Seok H.

    2009-01-01

    The ability to conduct high-resolution fluorescence imaging in internal organs of small animal models in situ and over time can make a significant impact in biomedical research. Toward this goal, we developed a real-time confocal and multiphoton endoscopic imaging system. Using 1-mm-diameter endoscopes based on gradient index lenses, we demonstrate video-rate multicolor multimodal imaging with cellular resolution in live mice. PMID:18315346

  1. MEMS-Based Dual Axes Confocal Microendoscopy

    PubMed Central

    Piyawattanametha, Wibool; Wang, Thomas D.

    2011-01-01

    We demonstrate a miniature, near-infrared microscope (? = 785 nm) that uses a novel dual axes confocal architecture. Scalability is achieved with post-objective scanning, and a MEMS mirror provides real time (>4 Hz) in vivo imaging. This instrument can achieve sub-cellular resolution with deep tissue penetration and large field of view. An endoscope-compatible version can image digestive tract epithelium to guide tissue biopsy and monitor therapy. PMID:22190845

  2. Study of neutron noise from reflected, metal assemblies with criticality safety applications in mind

    SciTech Connect

    Barnett, C.S.

    1985-08-20

    The author studied the statistics of detected neutrons that leaked from four subcritical reflected, enriched-uranium assemblies, to explore the feasibility of developing a criticality warning system based on neutron noise analysis. The calculated multiplication factors of the assemblies are 0.59, 0.74, 0.82, and 0.92. The author studied three possible discriminators, i.e., three signatures that might be used to discriminate among assemblies of various multiplications. They are: (1) variance-to-mean ratio of the counts in a time bin (V/M); (2) covariance-to-mean ratio of the counts in a common time bin from two different detectors (C/M); and (3) covariance-to-mean ratio of the counts from a single detector in two adjacent time bins of equal length, which the author calls the serial-covariance-to-mean ratio (SC/M). The performances of the three discriminators were not greatly different, but a hierarchy did emerge: SC/M greater than or equal to V/M greater than or equal to C/M. An example of some results: in the neighborhood of k = 0.6 the ..delta..k required for satisfactory discrimination varies from about 3% to 7% as detector solid angle varies from 19% to 5%. In the neighborhood of k = 0.8 the corresponding ..delta..ks are 1% and 2%. The noise analysis techniques studied performed well enough in deeply subcritical situations to deserve testing in an applications environment. They have a good chance of detecting changes in reactivity that are potentially dangerous. One can expect sharpest results when doing comparisons, i.e., when comparing two records, one taken in the past under circumstances known to be normal and one taken now to search for change.

  3. Quasi-simultaneous OCT/confocal imaging

    NASA Astrophysics Data System (ADS)

    Trifanov, Irina; Hughes, Michael; Rosen, Richard B.; Podoleanu, Adrian

    2008-04-01

    A new approach of acquiring quasi-simultaneous OCT and confocal images is presented. The two images are generated using different principles, optical coherence tomography (OCT) and confocal microscopy (CM). When the system is used to image the retina, the two images have depth resolutions, at present, of less than 20 ?m and approximately 1 mm respectively. The acquisition and display of en-face OCT and confocal images are quasi-simultaneous, without the need of a beam splitter. By using a chopper to periodically obstruct the reference beam in the OCT interferometer, synchronized with the XY-transversal scanner, much higher acquisition speed is obtained than in a previous report where we flipped an opaque screen in the reference arm of the interferometer. Successful operation of the novel configuration was achieved by: (1) stable synchronization of the chopper's movement with the horizontal line scanner and (2) fast self-adjusting of the gain value of avalanche photodiodes depending on the optical power. Images from coin, leafs and retina in vivo have been collected to demonstrate the functionality of the system.

  4. Visualization of confocal microscopic biomolecular data

    NASA Astrophysics Data System (ADS)

    Liu, Zhanping; Moorhead, Robert J., II

    2005-04-01

    Biomolecular visualization facilitates insightful interpretation of molecular structures and complex mechanisms underlying bio-chemical processes. Effective visualization techniques are required to deal with confocal microscopic biomolecular data in which intricate structures, fine features, and obscure patterns might be overlooked without sophisticated data processing and image synthesis. This paper presents major challenges in visualizing confocal microscopic biomolecular data, followed by a survey of related work. We then introduce a case study conducted to investigate the interaction between two proteins contained in a budding yeast saccharomyces cerevisiae by embedding custom modules in Amira. The multi-channel confocal microscopic volume data was first processed using an exponential operator to correct z-drop artifacts introduced during data acquisition. Channel correlation was then exploited to extract the overlap between the proteins as a new channel to represent the interaction while a statistical method was employed to compute the intensity of interaction to locate hot spots. To take advantage of crisp surface representation of region boundaries by iso-surfaces and visually pleasing translucent delineation of dense volumes by volume rendering, we adopted hybrid rendering that incorporates these two methods to display clear-cut protein boundaries, amorphous interior materials, and the scattered interaction in the same view volume with suppressed and highlighted parts selected by the user. The highlighted overlap helped biologists learn where the interaction happens and how it spreads, particularly when the volume was investigated in an immersive Cave Automatic Virtual Environment (CAVE) for intuitive comprehension of the data.

  5. Crystals and collimators for X-ray spectrometry. [Bragg reflection properties and design for astronomical applications

    NASA Technical Reports Server (NTRS)

    Mckenzie, D. L.; Landecker, P. B.; Underwood, J. H.

    1976-01-01

    Results of the measurement of Bragg reflection properties of crystals suitable for use in X-ray astronomy are presented. Measurements with a double crystal spectrometer were performed on rubidium acid phthalate and thallium acid phthalate to yield values of the integrated reflectivity and diffraction width in the range 8-18 A, and measurements of integrated reflectivity were also performed on ammonium dihydrogen phosphate. The theory and design of an arc-minute range multigrid collimator to be flown on a rocket for solar X-ray studies are also described, along with a method for determining the collimator's X-ray axis.

  6. Numerical study of a confocal ultrasonic setup for creation of cavitation

    NASA Astrophysics Data System (ADS)

    Lafond, Maxime; Chavrier, Françoise; Prieur, Fabrice; Mestas, Jean-Louis; Lafon, Cyril

    2015-10-01

    Acoustic cavitation is used for various therapeutic applications such as local enhancement of drug delivery, histotripsy or hyperthermia. One of the utmost important parameter for cavitation creation is the rarefaction pressure. The typical magnitude of the rarefaction pressure required to initiate cavitation from gas dissolved in tissue is beyond the range of the megapascal. Because nonlinear effects need to be taken into account, a numerical simulator based on the Westervelt equation was used to study the pressure waveform and the acoustic field generated by a setup for creation of cavitation consisting of two high intensity focused ultrasound transducers mounted confocally. At constant acoustic power, simulations with only one and both transducers from the confocal setup showed that the distortion of the pressure waveform due to the combined effects of nonlinearity and diffraction is less pronounced when both confocal transducers are used. Consequently, the confocal setup generates a greater peak negative pressure at focus which is more favorable for cavitation initiation. Comparison between the confocal setup and a single transducer with the same total emitting surface puts in evidence the role of the spatial separation of the two beams. Furthermore, it has been previously shown that the location of the peak negative pressure created by a single transducer shifts from focus towards the transducers in the presence of nonlinear effects. The simulator was used to study a configuration where the acoustical axes of transducers intersect on the peak negative pressure instead of the geometrical focus. For a representative confocal setup, namely moderate nonlinear effects, a 2% increase of the peak negative pressure and 8% decrease of the peak positive pressure resulted from this configuration. These differences tend to increase by increasing nonlinear effects. Although the optimal position of the transducers varies with the nonlinear regimen, the intersection point remains the location of the peak negative pressure in any case. Thus, unlike the location of the peak negative pressure for a single transducer can shift by a few millimeters, the focal point of a confocal device is independent of the power. This point is particularly important for therapeutic applications, frequently requiring high spatial accuracy. An experiment conducted shows that cavitation creation can be achieved easier with confocal ultrasound.

  7. Reflectance spectroscopy - Quantitative analysis techniques for remote sensing applications. [in planetary surface geology

    NASA Technical Reports Server (NTRS)

    Clark, R. N.; Roush, T. L.

    1984-01-01

    The empirical methods and scattering theories that are important for solving remote sensing problems are among the methods for remotely sensed reflectance data analysis presently compared. In the case of the photon mean optical path length concept's implications for reflectance spectra modeling, it is shown that the mean optical path length in a particulate surface is in roughly inverse proportion to the square root of the absorption coefficient. Absorption bands, which are Gaussian in shape when plotted as true absorptance vs photon energy, are also Gaussians in apparent absorptance, although they have a smaller intensity. An apparent continuum in a reflectance spectrum is modeled as a mathematical function that is used to isolate a particular absorption feature for analysis, and it is noted that this continuum should be removed by dividing it into the reflectance spectrum.

  8. Diagrammatic expansion of the Casimir energy in multiple reflections: Theory and applications

    E-print Network

    Faghfoor Maghrebi, Mohammad

    We develop a diagrammatic representation of the Casimir energy of a multibody configuration. The diagrams represent multiple reflections between the objects and can be organized by a few simple rules. The lowest-order ...

  9. Applications of shallow high-resolution seismic reflection to various environmental problems

    USGS Publications Warehouse

    Miller, R.D.; Steeples, D.W.

    1994-01-01

    Shallow seismic reflection has been successfully applied to environmental problems in a variety of geologic settings. Increased dynamic range of recording equipment and decreased cost of processing hardware and software have made seismic reflection a cost-effective means of imaging shallow geologic targets. Seismic data possess sufficient resolution in many areas to detect faulting with displacement of less than 3 m and beds as thin as 1 m. We have detected reflections from depths as shallow as 2 m. Subsurface voids associated with abandoned coal mines at depths of less than 20 m can be detected and mapped. Seismic reflection has been successful in mapping disturbed subsurface associated with dissolution mining of salt. A graben detected and traced by seismic reflection was shown to be a preferential pathway for leachate leaking from a chemical storage pond. As shown by these case histories, shallow high-resolution seismic reflection has the potential to significantly enhance the economics and efficiency of preventing and/or solving many environmental problems. ?? 1994.

  10. Confocal imaging of benign and malignant proliferative skin lesions in vivo

    NASA Astrophysics Data System (ADS)

    Gonzalez, Salvador; Rajadhyaksha, Milind M.; Anderson, R. Rox

    1999-06-01

    Near-infrared confocal reflectance microscopy (CM) provides non- invasive real-time images of thin en-face tissue sections with high resolution and contrast. Imaging of cells, nuclei, other organelles, microvessels, and hair follicles has been possible at resolution comparable to standard histology, to a maximum depth of 250-300 ?m in human skin in vivo. We have characterized psoriasis as a prototype of benign proliferative skin conditions, and non-pigmented skin malignancies in vivo based on their unstained, native histologic features using CM. Our data shows that reflectance CM may potentially diagnose and morphometrically evaluate proliferative skin lesions in vivo.

  11. Reflecting Reflective Practice

    ERIC Educational Resources Information Center

    Galea, Simone

    2012-01-01

    This paper demystifies reflective practice on teaching by focusing on the idea of reflection itself and how it has been conceived by two philosophers, Plato and Irigaray. It argues that reflective practice has become a standardized method of defining the teacher in teacher education and teacher accreditation systems. It explores how practices of…

  12. Diffusion of photoacid generators by laser scanning confocal microscopy

    NASA Astrophysics Data System (ADS)

    Zhang, Ping L.; Webber, Stephen E.; Mendenhall, J.; Byers, Jeffrey D.; Chao, Keith K.

    1998-06-01

    Diffusion of the photogenerated acid during the period of time between exposure and development can cause contrast loss and ultimately loss of the latent image. This is especially relevant for chemically amplified photoresists that require a post-exposure baking step, which in turn facilitates acid diffusion due to the high temperature normally employed. It is thus important to develop techniques with good spatial resolution to monitor the photogeneration of acid. More precisely, we need techniques that provide two distinct types of information: spatial resolution on various length scales within the surface layer and also sufficient depth resolution so that one can observe the transition from very surface layer to bulk structure in the polymer blend coated on silicon substrate. Herein laser scanning confocal microscopy is used to evaluate the resist for the first time. We report the use of the confocal microscopy to map the pag/dye distribution in PHS matrices, with both reflectance images and fluorescence images. A laser beam is focused onto a small 3D volume element, termed a voxel. It is typically 200 nm X 200 nm laterally and 800 nm axially. The illuminated voxel is viewed such that only signals emanating from this voxel are detected, i.e., signal from outside the probed voxel is not detected. By adjusting the vertical position of the laser focal point, the voxel can be moved to the designated lateral plane to produce an image. Contrast caused by topology difference between the exposed and unexposed area can be eliminated. Bis-p-butylphenyl iodonium triflat (7% of polyhydroxystyrene) is used as photoacid generators. 5% - 18% (by weight, PHS Mn equals 13 k) resist in PGMEA solution is spin cast onto the treated quartz disk with thickness of 1.4 micrometers , 5 micrometers space/10 micrometers pitch chrome mask is used to generate the pattern with mercury DUV illumination. Fluoresceinamine, the pH-sensitive dye, is also used to enhance the contrast of fluorescence image. The typical PEB temperature is 90 degree(s)C for 90 seconds. 488 nm is used as the excitation wavelength. Both reflectance and fluorescence images (> 510 nm) are processed by using Adobe Photoshop. It was found that the reflectance is more sensitive to the change of the refractive index of the resist while the fluorescence is more sensitive to the distribution of the PAG/dye. The NIH Image software is used for acid exchange rate calculation. Second Fick's Law is applied to analyze the image change. The diffusion coefficient for this PAG in PHS during PEB is smaller than 8.8 X 10-13 cm2/s.

  13. Imaging System With Confocally Self-Detecting Laser.

    DOEpatents

    Webb, Robert H. (Lincoln, MA); Rogomentich, Fran J. (Concord, MA)

    1996-10-08

    The invention relates to a confocal laser imaging system and method. The system includes a laser source, a beam splitter, focusing elements, and a photosensitive detector. The laser source projects a laser beam along a first optical path at an object to be imaged, and modulates the intensity of the projected laser beam in response to light reflected from the object. A beam splitter directs a portion of the projected laser beam onto a photodetector. The photodetector monitors the intensity of laser output. The laser source can be an electrically scannable array, with a lens or objective assembly for focusing light generated by the array onto the object of interest. As the array is energized, its laser beams scan over the object, and light reflected at each point is returned by the lens to the element of the array from which it originated. A single photosensitive detector element can generate an intensity-representative signal for all lasers of the array. The intensity-representative signal from the photosensitive detector can be processed to provide an image of the object of interest.

  14. Reflections on current and future applications of multiangle imaging to aerosol and cloud remote sensing

    NASA Astrophysics Data System (ADS)

    Diner, David

    2010-05-01

    The Multi-angle Imaging SpectroRadiometer (MISR) instrument has been collecting global Earth data from NASA's Terra satellite since February 2000. With its 9 along-track view angles, 4 spectral bands, intrinsic spatial resolution of 275 m, and stable radiometric and geometric calibration, no instrument that combines MISR's attributes has previously flown in space, nor is there is a similar capability currently available on any other satellite platform. Multiangle imaging offers several tools for remote sensing of aerosol and cloud properties, including bidirectional reflectance and scattering measurements, stereoscopic pattern matching, time lapse sequencing, and potentially, optical tomography. Current data products from MISR employ several of these techniques. Observations of the intensity of scattered light as a function of view angle and wavelength provide accurate measures of aerosol optical depths (AOD) over land, including bright desert and urban source regions. Partitioning of AOD according to retrieved particle classification and incorporation of height information improves the relationship between AOD and surface PM2.5 (fine particulate matter, a regulated air pollutant), constituting an important step toward a satellite-based particulate pollution monitoring system. Stereoscopic cloud-top heights provide a unique metric for detecting interannual variability of clouds and exceptionally high quality and sensitivity for detection and height retrieval for low-level clouds. Using the several-minute time interval between camera views, MISR has enabled a pole-to-pole, height-resolved atmospheric wind measurement system. Stereo imagery also makes possible global measurement of the injection heights and advection speeds of smoke plumes, volcanic plumes, and dust clouds, for which a large database is now available. To build upon what has been learned during the first decade of MISR observations, we are evaluating algorithm updates that not only refine retrieval accuracies but also include enhancements (e.g., finer spatial resolution) that would have been computationally prohibitive just ten years ago. In addition, we are developing technological building blocks for future sensors that enable broader spectral coverage, wider swath, and incorporation of high-accuracy polarimetric imaging. Prototype cameras incorporating photoelastic modulators have been constructed. To fully capitalize on the rich information content of the current and next-generation of multiangle imagers, several algorithmic paradigms currently employed need to be re-examined, e.g., the use of aerosol look-up tables, neglect of 3-D effects, and binary partitioning of the atmosphere into "cloudy" or "clear" designations. Examples of progress in algorithm and technology developments geared toward advanced application of multiangle imaging to remote sensing of aerosols and clouds will be presented.

  15. Multispectral fluorescence and reflectance imaging at the leaf level and its possible applications.

    PubMed

    Lenk, Sándor; Chaerle, Laury; Pfündel, Erhard E; Langsdorf, Gabriele; Hagenbeek, Dik; Lichtenthaler, Hartmut K; Van Der Straeten, Dominique; Buschmann, Claus

    2007-01-01

    Images taken at different spectral bands are increasingly used for characterizing plants and their health status. In contrast to conventional point measurements, imaging detects the distribution and quantity of signals and thus improves the interpretation of fluorescence and reflectance signatures. In multispectral fluorescence and reflectance set-ups, images are separately acquired for the fluorescence in the blue, green, red, and far red, as well as for the reflectance in the green and in the near infrared regions. In addition, 'reference' colour images are taken with an RGB (red, green, blue) camera. Examples of imaging for the detection of photosynthetic activity, UV screening caused by UV-absorbing substances, fruit quality, leaf tissue structure, and disease symptoms are introduced. Subsequently, the different instrumentations used for multispectral fluorescence and reflectance imaging of leaves and fruits are discussed. Various types of irradiation and excitation light sources, detectors, and components for image acquisition and image processing are outlined. The acquired images (or image sequences) can be analysed either directly for each spectral range (wherein they were captured) or after calculating ratios of the different spectral bands. This analysis can be carried out for different regions of interest selected manually or (semi)-automatically. Fluorescence and reflectance imaging in different spectral bands represents a promising tool for non-destructive plant monitoring and a 'road' to a broad range of identification tasks. PMID:17118970

  16. The continuum slope of Mars - Bidirectional reflectance investigations and applications to Olympus Mons

    NASA Technical Reports Server (NTRS)

    Fischer, Erich M.; Pieters, Carle M.

    1993-01-01

    Two primary causes of near-IR continuum slope variations have been observed in an investigation of the bidirectional reflectance characteristics of ferric coatings on the continuum slope of Mars. First, the presence of a thin ferric coating on a dark substrate produces a negative continuum slope due to the wavelength-dependent transparency of the ferric coating. Second, wavelength-dependent directional reflectance occurs when the surface particles are tightly packed, particle sizes are on the order of or smaller than the wavelength of light, or the surface is otherwise smooth on the order of the wavelength of light. Based on these results, the annuli on the flanks of Olympus Mons which are defined by reflectance and continuum slope are consistent with spatial variations in surface texture and possibly with spatial variations in the thickness of a ferric dust coating or rind.

  17. Fluorescence performance standards for confocal microscopy

    NASA Astrophysics Data System (ADS)

    Rüttinger, Steffen; Kapusta, Peter; Völlkopf, Volker; Koberling, Felix; Erdmann, Rainer; Macdonald, Rainer

    2010-02-01

    State of the art confocal microscopes offer diffraction limited (or even better) spatial resolution, highest (single molecule) sensitivity and ps-fluorescence lifetime measurement accuracy. For developers, manufacturers, as well as users of confocal microscopes it is mandatory to assign values to these qualities. In particular for users, it is often not easy to ascertain that the instrument is properly aligned as a large number of factors influence resolution or sensitivity. Therefore, we aspire to design a set of performance standards to be deployed on a day-to-day fashion in order to check the instruments characteristics. The main quantities such performance standard must address are: • Spatial resolution • Sensitivity • Fluorescence lifetime To facilitate the deployment and thus promote wide range adoption in day-to-day performance testing the corresponding standards have to be ready made, easy to handle and to store. The measurement procedures necessary should be available on as many different setups as possible and the procedures involved in their deployment should be as easy as possible. To this end, we developed two performance standards to accomplish the mentioned goals: • Resolution reference • Combined molecular brightness and fluorescence lifetime reference The first one is based on sub-resolution sized Tetra-SpeckTM fluorescent beads or alternatively on single molecules on a glass surface to image and to determine quantitatively the confocal volume, while the latter is a liquid sample containing fluorescent dyes of different concentrations and spectral properties. Both samples are sealed in order to ease their use and prolong their storage life. Currently long-term tests are performed to ascertain durability and road capabilities.

  18. [Application of near infrared reflectance spectroscopy to predict meat chemical compositions: a review].

    PubMed

    Tao, Lin-Li; Yang, Xiu-Juan; Deng, Jun-Ming; Zhang, Xi

    2013-11-01

    In contrast to conventional methods for the determination of meat chemical composition, near infrared reflectance spectroscopy enables rapid, simple, secure and simultaneous assessment of numerous meat properties. The present review focuses on the use of near infrared reflectance spectroscopy to predict meat chemical compositions. The potential of near infrared reflectance spectroscopy to predict crude protein, intramuscular fat, fatty acid, moisture, ash, myoglobin and collagen of beef, pork, chicken and lamb is reviewed. This paper discusses existing questions and reasons in the current research. According to the published results, although published results vary considerably, they suggest that near-infrared reflectance spectroscopy shows a great potential to replace the expensive and time-consuming chemical analysis of meat composition. In particular, under commercial conditions where simultaneous measurements of different chemical components are required, near infrared reflectance spectroscopy is expected to be the method of choice. The majority of studies selected feature-related wavelengths using principal components regression, developed the calibration model using partial least squares and modified partial least squares, and estimated the prediction accuracy by means of cross-validation using the same sample set previously used for the calibration. Meat fatty acid composition predicted by near-infrared spectroscopy and non-destructive prediction and visualization of chemical composition in meat using near-infrared hyperspectral imaging and multivariate regression are the hot studying field now. On the other hand, near infrared reflectance spectroscopy shows great difference for predicting different attributes of meat quality which are closely related to the selection of calibration sample set, preprocessing of near-infrared spectroscopy and modeling approach. Sample preparation also has an important effect on the reliability of NIR prediction; in particular, lack of homogeneity of the meat samples influenced the accuracy of estimation of chemical components. In general the predicting results of intramuscular fat, fatty acid and moisture are best, the predicting results of crude protein and myoglobin are better, while the predicting results of ash and collagen are less accurate. PMID:24555369

  19. MEMS-BASED 3D CONFOCAL SCANNING MICROENDOSCOPE USING MEMS SCANNERS FOR BOTH LATERAL AND AXIAL SCAN

    PubMed Central

    Liu, Lin; Wang, Erkang; Zhang, Xiaoyang; Liang, Wenxuan; Li, Xingde; Xie, Huikai

    2014-01-01

    A fiber-optic 3D confocal scanning microendoscope employing MEMS scanners for both lateral and axial scan was designed and constructed. The MEMS 3D scan engine achieved a lateral scan range of over ± 26° with a 2D MEMS scanning micromirror and a depth scan of over 400 ?m with a 1D MEMS tunable microlens. The lateral resolution and axial resolution of this system were experimentally measured as 1.0 ?m and 7.0 ?m, respectively. 2D and 3D confocal reflectance images of micro-patterns, micro-particles, onion skins and acute rat brain tissue were obtained by this MEMS-based 3D confocal scanning microendoscope. PMID:25013304

  20. MEMS-BASED 3D CONFOCAL SCANNING MICROENDOSCOPE USING MEMS SCANNERS FOR BOTH LATERAL AND AXIAL SCAN.

    PubMed

    Liu, Lin; Wang, Erkang; Zhang, Xiaoyang; Liang, Wenxuan; Li, Xingde; Xie, Huikai

    2014-08-15

    A fiber-optic 3D confocal scanning microendoscope employing MEMS scanners for both lateral and axial scan was designed and constructed. The MEMS 3D scan engine achieved a lateral scan range of over ± 26° with a 2D MEMS scanning micromirror and a depth scan of over 400 ?m with a 1D MEMS tunable microlens. The lateral resolution and axial resolution of this system were experimentally measured as 1.0 ?m and 7.0 ?m, respectively. 2D and 3D confocal reflectance images of micro-patterns, micro-particles, onion skins and acute rat brain tissue were obtained by this MEMS-based 3D confocal scanning microendoscope. PMID:25013304

  1. Confocal laser endomicroscopy for gastrointestinal diseases.

    PubMed

    Kiesslich, Ralf; Goetz, Martin; Neurath, Markus F

    2008-07-01

    Confocal laser endomicroscopy enables in vivo microscopy of the mucosal layer of the gastrointestinal tract with subcellular resolution during ongoing endoscopy. Endomicroscopy opens the door to immediate tissue and vessel analysis. Different types of diseases can be diagnosed with optical surface and subsurface analysis. Analysis of the in vivo microarchitecture can be used for targeting biopsies to relevant areas, and subsurface imaging can unmask microscopic diseases or bacterial infection. Molecular imaging is becoming feasible, which will enable new indications in gastrointestinal endoscopy. This article reviews the current and rapidly expanding clinical data on endomicroscopy and gives a look into future research. PMID:18674696

  2. Bidirectional Reflectance of Flat, Optically Thick Particulate Layers: An Efficient Radiative Transfer Solution and Applications to Snow and Soil Surfaces

    NASA Technical Reports Server (NTRS)

    Mishchenko, Michael I.; Dlugach, Janna M.; Yanovitsku, Edgard G.; Zakharova, Nadia T.

    1999-01-01

    We describe a simple and highly efficient and accurate radiative transfer technique for computing bidirectional reflectance of a macroscopically flat scattering layer composed of nonabsorbing or weakly absorbing, arbitrarily shaped, randomly oriented and randomly distributed particles. The layer is assumed to be homogeneous and optically semi-infinite, and the bidirectional reflection function (BRF) is found by a simple iterative solution of the Ambartsumian's nonlinear integral equation. As an exact Solution of the radiative transfer equation, the reflection function thus obtained fully obeys the fundamental physical laws of energy conservation and reciprocity. Since this technique bypasses the computation of the internal radiation field, it is by far the fastest numerical approach available and can be used as an ideal input for Monte Carlo procedures calculating BRFs of scattering layers with macroscopically rough surfaces. Although the effects of packing density and coherent backscattering are currently neglected, they can also be incorporated. The FORTRAN implementation of the technique is available on the World Wide Web at http://ww,,v.giss.nasa.gov/-crmim/brf.html and can be applied to a wide range of remote sensing, engineering, and biophysical problems. We also examine the potential effect of ice crystal shape on the bidirectional reflectance of flat snow surfaces and the applicability of the Henyey-Greenstein phase function and the 6-Eddington approximation in calculations for soil surfaces.

  3. Being In-Between: Reflecting on Time, Space and Career during the Tenure Application Process

    ERIC Educational Resources Information Center

    Eichler, Mathew

    2015-01-01

    Part of the process of becoming a tenured faculty member is applying for tenure. This reflective essay reports on the period after the submission of tenure materials for review but before the review process for tenure is completed. This is an "in-between" space, where the race of the tenure track is no longer present, but the role of…

  4. Multimodal confocal mosaics enable high sensitivity and specificity in screening of in situ squamous cell carcinoma

    NASA Astrophysics Data System (ADS)

    Grados Luyando, Maria del Carmen; Bar, Anna; Snavely, Nicholas; Jacques, Steven; Gareau, Daniel S.

    2014-02-01

    Screening cancer in excision margins with confocal microscopy may potentially save time and cost over the gold standard histopathology (H and E). However, diagnostic accuracy requires sufficient contrast and resolution to reveal pathological traits in a growing set of tumor types. Reflectance mode images structural details due to microscopic refractive index variation. Nuclear contrast with acridine orange fluorescence provides enhanced diagnostic value, but fails for in situ squamous cell carcinoma (SCC), where the cytoplasm is important to visualize. Combination of three modes [eosin (Eo) fluorescence, reflectance (R) and acridine orange (AO) fluorescence] enable imaging of cytoplasm, collagen and nuclei respectively. Toward rapid intra-operative pathological margin assessment to guide staged cancer excisions, multimodal confocal mosaics can image wide surgical margins (~1cm) with sub-cellular resolution and mimic the appearance of conventional H and E. Absorption contrast is achieved by alternating the excitation wavelength: 488nm (AO fluorescence) and 532nm (Eo fluorescence). Superposition and false-coloring of these modes mimics H and E, enabling detection of the carcinoma in situ in the epidermal layer The sum mosaic Eo+R is false-colored pink to mimic eosins' appearance in H and E, while the AO mosaic is false-colored purple to mimic hematoxylins' appearance in H and E. In this study, mosaics of 10 Mohs surgical excisions containing SCC in situ and 5 containing only normal tissue were subdivided for digital presentation equivalent to 4X histology. Of the total 16 SCC in situ multimodal mosaics and 16 normal cases presented, two reviewers made 1 and 2 (respectively) type-2 errors (false positives) but otherwise scored perfectly when using the confocal images to screen for the presence of SCC in situ as compared to the gold standard histopathology. Limitations to precisely mimic H and E included occasional elastin staining by AO. These results suggest that confocal mosaics may effectively guide staged SCC excisions in skin and other tissues.

  5. Confocal Raman imaging for cancer cell classification

    NASA Astrophysics Data System (ADS)

    Mathieu, Evelien; Van Dorpe, Pol; Stakenborg, Tim; Liu, Chengxun; Lagae, Liesbet

    2014-05-01

    We propose confocal Raman imaging as a label-free single cell characterization method that can be used as an alternative for conventional cell identification techniques that typically require labels, long incubation times and complex sample preparation. In this study it is investigated whether cancer and blood cells can be distinguished based on their Raman spectra. 2D Raman scans are recorded of 114 single cells, i.e. 60 breast (MCF-7), 5 cervix (HeLa) and 39 prostate (LNCaP) cancer cells and 10 monocytes (from healthy donors). For each cell an average spectrum is calculated and principal component analysis is performed on all average cell spectra. The main features of these principal components indicate that the information for cell identification based on Raman spectra mainly comes from the fatty acid composition in the cell. Based on the second and third principal component, blood cells could be distinguished from cancer cells; and prostate cancer cells could be distinguished from breast and cervix cancer cells. However, it was not possible to distinguish breast and cervix cancer cells. The results obtained in this study, demonstrate the potential of confocal Raman imaging for cell type classification and identification purposes.

  6. Application of the Total Reflection X-ray Fluorescence technique to trace elements determination in tobacco

    NASA Astrophysics Data System (ADS)

    Martinez, T.; Lartigue, J.; Zarazua, G.; Avila-Perez, P.; Navarrete, M.; Tejeda, S.

    2008-12-01

    Many studies have identified an important number of toxic elements along with organic carcinogen molecules and radioactive isotopes in tobacco. In this work we have analyzed by Total Reflection X-Ray Fluorescence 9 brands of cigarettes being manufactured and distributed in the Mexican market. Two National Institute of Standards and Technology standards and a blank were equally treated at the same time. Results show the presence of some toxic elements such as Pb and Ni. These results are compared with available data for some foreign brands, while their implications for health are discussed. It can be confirmed that the Total Reflection X-Ray Fluorescence method provides precise (reproducible) and accuracy (trueness) data for 15 elements concentration in tobacco samples.

  7. An adaptive phase space method with application to reflection traveltime tomography

    NASA Astrophysics Data System (ADS)

    Chung, Eric; Qian, Jianliang; Uhlmann, Gunther; Zhao, Hongkai

    2011-11-01

    In this work, an adaptive strategy for the phase space method for traveltime tomography (Chung et al 2007 Inverse Problems 23 309-29) is developed. The method first uses those geodesics/rays that produce smaller mismatch with the measurements and continues on in the spirit of layer stripping without defining the layers explicitly. The adaptive approach improves stability, efficiency and accuracy. We then extend our method to reflection traveltime tomography by incorporating broken geodesics/rays for which a jump condition has to be imposed at the broken point for the geodesic flow. In particular, we show that our method can distinguish non-broken and broken geodesics in the measurement and utilize them accordingly in reflection traveltime tomography. We demonstrate that our method can recover the convex hull (with respect to the underlying metric) of unknown obstacles as well as the metric outside the convex hull.

  8. Optimization and Application of Reflective LSPR Optical Fiber Biosensors Based on Silver Nanoparticles

    PubMed Central

    Chen, Jiangping; Shi, Se; Su, Rongxin; Qi, Wei; Huang, Renliang; Wang, Mengfan; Wang, Libing; He, Zhimin

    2015-01-01

    In this study, we developed a reflective localized surface plasmon resonance (LSPR) optical fiber sensor, based on silver nanoparticles (Ag NPs). To enhance the sensitivity of the LSPR optical sensor, two key parameters were optimized, the length of the sensing area and the coating time of the Ag NPs. A sensing length of 1.5 cm and a 1-h coating time proved to be suitable conditions to produce highly sensitive sensors for biosensing. The optimized sensor has a high refractive index sensitivity of 387 nm/RIU, which is much higher than that of other reported individual silver nanoparticles in solutions. Moreover, the sensor was further modified with antigen to act as a biosensor. Distinctive wavelength shifts were found after each surface modification step. In addition, the reflective LSPR optical fiber sensor has high reproducibility and stability. PMID:26016910

  9. Optimization and application of reflective LSPR optical fiber biosensors based on silver nanoparticles.

    PubMed

    Chen, Jiangping; Shi, Se; Su, Rongxin; Qi, Wei; Huang, Renliang; Wang, Mengfan; Wang, Libing; He, Zhimin

    2015-01-01

    In this study, we developed a reflective localized surface plasmon resonance (LSPR) optical fiber sensor, based on silver nanoparticles (Ag NPs). To enhance the sensitivity of the LSPR optical sensor, two key parameters were optimized, the length of the sensing area and the coating time of the Ag NPs. A sensing length of 1.5 cm and a 1-h coating time proved to be suitable conditions to produce highly sensitive sensors for biosensing. The optimized sensor has a high refractive index sensitivity of 387 nm/RIU, which is much higher than that of other reported individual silver nanoparticles in solutions. Moreover, the sensor was further modified with antigen to act as a biosensor. Distinctive wavelength shifts were found after each surface modification step. In addition, the reflective LSPR optical fiber sensor has high reproducibility and stability. PMID:26016910

  10. G.M.P. van Kempen, L.J. van Vliet, and P.J. Verveer, Application of image restoration methods for confocal fluorescence microscopy, in: C.J. Cogswell, J.-A. Conchello, T. Wilson (eds.), 3-D Microscopy: Image Acquisition and Processing IV,

    E-print Network

    van Vliet, Lucas J.

    for confocal fluorescence microscopy, in: C.J. Cogswell, J.-A. Conchello, T. Wilson (eds.), 3-D Microscopy that invert these distortions will improve these analyses. We have tested the performances of the Richardson with a confocal point spread function and distorted with Poisson noise. keywords: Image restoration, Richardson

  11. G.M.P. van Kempen, L.J. van Vliet, and P.J. Verveer, Application of image restoration methods for confocal fluorescence microscopy, in: C.J. Cogswell, J.A. Conchello, T. Wilson (eds.), 3D Microscopy: Image Acquisition and Processing IV,

    E-print Network

    van Vliet, Lucas J.

    for confocal fluorescence microscopy, in: C.J. Cogswell, J.­A. Conchello, T. Wilson (eds.), 3­D Microscopy that invert these distortions will improve these analyses. We have tested the performances of the Richardson with a confocal point spread function and distorted with Poisson noise. keywords: Image restoration, Richardson

  12. Dye-enhanced multimodal confocal microscopy for noninvasive detection of skin cancers in mouse models.

    PubMed

    Park, Jesung; Mroz, Pawel; Hamblin, Michael R; Yaroslavsky, Anna N

    2010-01-01

    Skin cancer is the most common form of human cancer. Its early diagnosis and timely treatment is of paramount importance for dermatology and surgical oncology. In this study, we evaluate the use of reflectance and fluorescence confocal microscopy for detecting skin cancers in an in-vivo trial with B16F10 melanoma and SCCVII squamous cell carcinoma in mice. For the experiments, the mice are anesthetized, then the tumors are infiltrated with aqueous solution of methylene blue and imaged. Reflectance images are acquired at 658 nm. Fluorescence is excited at 658 nm and registered in the range between 690 and 710 nm. After imaging, the mice are sacrificed. The tumors are excised and processed for hematoxylin and eosin histopathology, which is compared to the optical images. The results of the study indicate that in-vivo reflectance images provide valuable information on vascularization of the tumor, whereas the fluorescence images mimic the structural features seen in histopathology. Simultaneous dye-enhanced reflectance and fluorescence confocal microscopy shows promise for the detection, demarcation, and noninvasive monitoring of skin cancer development. PMID:20459268

  13. Spectral reflectance of carbonate sediments and application to remote sensing classification of benthic habitats

    NASA Astrophysics Data System (ADS)

    Louchard, Eric Michael

    Remote sensing is a valuable tool in marine research that has advanced to the point that images from shallow waters can be used to identify different seafloor types and create maps of benthic habitats. A major goal of this dissertation is to examine differences in spectral reflectance and create new methods of analyzing shallow water remote sensing data to identify different seafloor types quickly and accurately. Carbonate sediments were used as a model system as they presented a relatively uniform, smooth surface for measurement and are a major bottom type in tropical coral reef systems. Experimental results found that sediment reflectance varied in shape and magnitude depending on pigment content, but only varied in magnitude with variations in grain size and shape. Derivative analysis of the reflectance spectra identified wavelength regions that correlate to chlorophyll a and chlorophyllide a as well as accessory pigments, indicating differences in microbial community structure. Derivative peak height also correlated to pigment content in the sediments. In remote sensing data, chlorophyll a, chlorophyllide a, and some xanthophylls were identified in derivative spectra and could be quantified from second derivative peak height. Most accessory pigments were attenuated by the water column, however, and could not be used to quantify pigments in sediments from remote sensing images. Radiative transfer modeling of remote sensing reflectance showed that there was sufficient spectral variation to separate major sediment types, such as ooid shoals and sediment with microbial layers, from different densities of seagrass and pavement bottom communities. Both supervised classification with a spectral library and unsupervised classification with principal component analysis were used to create maps of seafloor type. The results of the experiments were promising; classified seafloor types correlated with ground truth observations taken from underwater video and were comparable to existing maps of seafloor type. Creation of accurate seafloor type maps is an important step in constructing maps of benthic habitats.

  14. Evaluation and purchase of confocal microscopes: Numerous factors to consider

    EPA Science Inventory

    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...

  15. CONFOCAL LASER SCANNING MICROSCOPY OF RAT FOLLICLE DEVELOPMENT

    EPA Science Inventory

    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...

  16. Reflections on reflective practice.

    PubMed

    Kinsella, E A

    2001-06-01

    In recent years, a wide range of professions have adopted 'reflective practice' as an approach to professional development, and many professions have made it a mandatory dimension of their membership credentialling process. Despite the fact that it has been widely taken up in the professional world, there are many different conceptualizations and ideas about what it is. In this paper, six theoretical underpinnings of reflective practice are considered, and suggestions are made about how we can begin to incorporate reflection into our own practices. PMID:11433918

  17. Fabrication of highly transparent diamond-like carbon anti-reflecting coating for Si solar cell application

    SciTech Connect

    Banerjee, Amit Das, Debajyoti

    2014-04-24

    ARC grade highly transparent unhydrogenated diamond-like carbon (DLC) films were produced, directly from a-C target, using RF magnetron sputtering deposition technique, for optoelectronic applications. Optical band gap, transmittance, reflectance, sp{sup 3} fraction, I{sub D}/I{sub G}, density, and refractive index of the films have been estimated with the help of optical tools like Uv-vis spectrophotometer, ellipsometer and micro-Raman. Optimum ARC-qualities have been identified in low-temperature grown DLC films at an Ar pressure of 4 mTorr in the reactor, accomplishing its key requirements for use in silicon solar cells.

  18. Reflectors with directional-mixed reflection properties for application in luminaries with high-power LED diodes

    NASA Astrophysics Data System (ADS)

    Zaremba, Krzysztof

    2008-06-01

    Application of directional-mixed reflectors results in a luminance decrease of the apparent image of light emitting diodes (LEDs), which is advantageous as far as glare reduction is concerned. On the other hand, reflectors have a negative impact on luminous intensity curves of the luminaries. This work analyzes an impact of surfaces with directional-mixed reflection properties in a mirror reflector designed for a luminary equipped with high-power LEDs. We present an algorithm used to determine the shape of the reflector of the surface with small scattering, where the axis twist angle for a parabolic reflector varies in a predefined range and follows a power function.

  19. Confocal axial beam scanning through LC-SLM

    NASA Astrophysics Data System (ADS)

    Zou, Limin; Dong, Jin; Fan, Zhigang

    2010-08-01

    The axial beam scanning in confocal microscopy has been implemented using liquid crystal spatial light modulator (LC-SLM). A zoom illuminating lens is realized by introducing LC-SLM into the confocal illumination light path, and thus it shifts the focus of the objective lens axially. The axial optical sectioning in a conventional confocal microscope is hereby achieved by beam scanning rather than mechanically moving the objective lens. The axial focus shift of the objective lens is realized by changing the modulation phase bitmaps of LC-SLM. By electrically controlling LC-SLM, it has been demonstrated that the focus can shift in the axial direction continuously over a 100?m range, while the FWHM of the focal spot keeps the same as that without LC-SLM. Experimental results further show that the axial intensity curves shift axially in confocal microscopy and confocal axial beam scanning replacing mechanical scanning can therefore be implemented.

  20. In Vivo Confocal Microscopy after Corneal Collagen Crosslinking.

    PubMed

    Mazzotta, Cosimo; Hafezi, Farhad; Kymionis, George; Caragiuli, Stefano; Jacob, Soosan; Traversi, Claudio; Barabino, Stefano; Randleman, J Bradley

    2015-10-01

    In vivo confocal microscopy (IVCM) findings of 84 patients who had undergone conventional epithelium-off corneal collagen crosslinking (CXL) and accelerated CXL (ACXL) were retrospectively reviewed. Analysis confirmed that despite a significant decrease in the mean density of anterior keratocytes in the first 6 postoperative months, cell density after CXL and ACXL returned to baseline values at 12 months. The demarcation lines observed after treatments represent an expression of light-scattering (reflectivity changes) through different tissue densities. Temporary haze of the anterior-mid stroma after conventional CXL represents an indirect sign of CXL-induced stromal collagen compaction and remodeling. IVCM showed that treatment penetration varies to some extent, but that the endothelium is not damaged and is correlated with CXL biomechanical effects. IVCM of limbal structures shows no evidence of pathological changes. Regeneration of subepithelial and stromal nerves was complete 12 months after the operation with fully restored corneal sensitivity and no neurodystrophic occurrences. IVCM allowed detailed high magnification in vivo micromorphological analysis of corneal layers, enabling the assessment of early and late corneal modifications induced by conventional and accelerated CXL. IVCM confirms that CXL is a safe procedure, which is still undergoing development and protocol adjustments. PMID:26142059

  1. Gold nanoparticles sensing with diffusion reflection measurement as a new medical diagnostics application

    NASA Astrophysics Data System (ADS)

    Fixler, Dror

    2014-02-01

    The ability to quantitatively and noninvasively detect nanoparticles in vivo has important implications on their development as optical sensors for medical diagnostics. We suggest a new method for cancer detection based on diffusion reflection (DR) measurements of gold nanorods (GNR). In our talk, the ability to extract optical properties of phantoms and their GNR concentrations from DR measurements will demonstrate. We will report, for the first time, GNR detection through upper tissue-like phantom layers, as well as the detection of a tumor presented as highly concentrated GNR placed deep within a phantom.

  2. Control of photodissociation branching using the complete reflection phenomenon: Application to HI molecule

    E-print Network

    Hiroshi Fujisaki; Yoshiaki Teranishi; Hiroki Nakamura

    2002-11-22

    The laser control of photodissociation branching in a diatomic molecule is demonstrated to be effectively achieved with use of the complete reflection phenomenon. The phenomenon and the control condition can be nicely formulated by the semiclassical (Zhu-Nakamura) theory. The method is applied to the branching between I($^2 P_{3/2}$) (HI $\\to$ H + I) and I$^*(^2 P_{1/2})$ (HI $\\to$ H + I$^*$) formation, and nearly complete control is shown to be possible by appropriately choosing an initial vibrational state and laser frequency in spite of the fact that there are three electronically excited states involved. Numerical calculations of the corresponding wavepacket dynamics confirm the results.

  3. Digital confocal microscopy through a multimode fiber

    NASA Astrophysics Data System (ADS)

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

    2015-09-01

    Confocal laser-scanning microscopy is a well-known optical imaging method where a pinhole is used in the illumination and detection pathways of a normal microscope, in order to selectively excite and detect a particular focal volume. The advantage of this method is a significant increase in contrast, due to the rejection of background contributions to the signal. Here, we propose to apply this method in the context of multimode fiber endoscopy. Due to modal scrambling, it is not possible to use a physical pinhole to filter light signals that have travel through multimode fibers. Instead, we use a transmission matrix approach to characterize the propagation of light through the fiber, and we apply the filtering operation in the digital domain.

  4. Fluorescence confocal endomicroscopy in biological imaging

    NASA Astrophysics Data System (ADS)

    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 <1mm diameter to transfer the confocal imaging plane to tissue in intact small animal organs, albeit at lower resolution (30,000 sampling points/image). In rodent models, imaging was performed using various fluorescent staining protocols including fluorescently labelled receptor ligands, labelled antibodies, FITC-dextrans, vital dyes and labelled cells administered topically or intravenously. Abdominal organs of large animals were accessed laparoscopically and contrasted using i.v. fluorescein-sodium. Articular cartilage 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. Fluorescein endomicroscopy has recently been introduced into the medical device market as a clinical imaging tool in GI endoscopy and is undergoing clinical evaluation in laparoscopic surgery. This medical usage is encouraging in-situ endomicroscopy as an important pre-clinical research tool to observe microscopic and molecular system biologic events in vivo in animal models for various human diseases.

  5. Three-dimensional scanning confocal laser microscope

    DOEpatents

    Anderson, R. Rox (Lexington, MA); Webb, Robert H. (Lincoln, MA); Rajadhyaksha, Milind (Charlestown, MA)

    1999-01-01

    A confocal microscope for generating an image of a sample includes a first scanning element for scanning a light beam along a first axis, and a second scanning element for scanning the light beam at a predetermined amplitude along a second axis perpendicular to the first axis. A third scanning element scans the light beam at a predetermined amplitude along a third axis perpendicular to an imaging plane defined by the first and second axes. The second and third scanning element are synchronized to scan at the same frequency. The second and third predetermined amplitudes are percentages of their maximum amplitudes. A selector determines the second and third predetermined amplitudes such that the sum of the percentages is equal to one-hundred percent.

  6. Transmissive grating-reflective mirror-based fiber optic accelerometer for stable signal acquisition in industrial applications

    NASA Astrophysics Data System (ADS)

    Lee, Yeon-Gwan; Kim, Dae-Hyun; Kim, Chun-Gon

    2012-05-01

    This paper discusses an applicable fiber-optic accelerometer composed of a transmissive grating panel, a reflection mirror, and two optical fibers with a separation of quarter grating pitch as transceivers that monitor the low-frequency accelerations of civil engineering structures. This sensor structure brings together the advantages of both a simple sensor structure, which leads to simplified cable design by 50% in comparison with the conventional transmission-type fiber optic accelerometer, and a stable reflected signals acquisition with repeatability in comparison to the researched grating-reflection type fiber optic accelerometer. The vibrating displacement and sinusoidal acceleration measured from the proposed fiber optic sensor demonstrated good agreement with those of a commercial laser displacement sensor and a MEMS accelerometer without electromagnetic interference. The developed fiber optic accelerometer can be used in frequency ranges below 4.0 Hz with a margin of error that is less than 5% and a high sensitivity of 5.06 rad/(m/s)2.

  7. Lifshitz theory of atom-wall interaction with applications to quantum reflection

    E-print Network

    V. B. Bezerra; G. L. Klimchitskaya; V. M. Mostepanenko; C. Romero

    2008-09-30

    The Casimir-Polder interaction of an atom with a metallic wall is investigated in the framework of the Lifshitz theory. It is demonstrated that in some temperature (separation) region the Casimir-Polder entropy takes negative values and goes to zero when the temperature vanishes. This result is obtained both for an ideal metal wall and for real metal walls. Simple analytical representations for the Casimir-Polder free energy and force are also obtained. These results are used to make a comparison between the phenomenological potential used in the theoretical description of quantum reflection and exact atom-wall interaction energy, as given by the Lifshitz theory. Computations are performed for the atom of metastable He${}^{\\ast}$ interacting with metal (Au) and dielectric (Si) walls. It is shown that the relative differences between the exact and phenomenological interaction energies are smaller in the case of a metallic wall. This is explained by the effect of negative entropy which occurs only for a metal wall. More accurate atom-wall interaction energies computed here can be used for the interpretation of measurement data in the experiments on quantum reflection.

  8. A New Diffuse Reflecting Material with Applications Including Integrating Cavity Ring-Down Spectroscopy 

    E-print Network

    Cone, Michael Thomas

    2014-04-16

    ever produced. The material is a high-purity fumed silica, or quartz powder. We demonstrate the application of this new material to several areas of integrating cavity enhanced spectroscopy, including absorption, Raman, and fluorescence spectroscopy...

  9. Polarization Of Light Reflected From Forest Canopies On Earth With Applications To Earth-like Planets With Realistic Cloud Cover

    NASA Astrophysics Data System (ADS)

    Wolstencroft, Ramon D.; Breon, F.; Tranter, G.

    2007-05-01

    Quasi-specular reflection of sunlight at the waxy surface of a leaf yields appreciably polarized light especially near the Brewster angle. Sunlight entering the leaf is either absorbed by photosynthetic pigments or, after reflection at internal surfaces, emerges as a diffuse component with a non-zero but low linear polarization and a yet smaller level of circular polarization. The net polarization varies with the leaf's surface roughness, internal architecture and health and is difficult to model. The polarization of a forest canopy is complex and depends especially on the leaf orientation distribution. The global polarization and reflectance properties of Planet Earth have been measured by the POLDER satellite: at 443nm atmospheric Rayleigh scattering dominates, but at 865nm the average surface properties of ocean, vegetation, desert and snow can be estimated. For cloud-free surfaces at 865nm and 90 degree phase angle the percentage polarization,p, and reflectance,R, are respectively [55%,9%](ocean), [7%,23%](vegetation), [6%,40%](desert) and [3%,80%](snow). Note that the values for clear and cloudy ocean are very different, viz [55%,9%] and [4%,45%] respectively. Allowing for the fractional global areas of each component and a global cloud cover of 55% yields p=7.3% for a pale-blue-dot Earth. pR is greatest for oceans and least for vegetation and hence the prospects for detecting pR from vegetation on an Earth-like planet are poor unless >50% is covered in vegetation. However prospects of using the phase angle and wavelength dependence of a pale-blue-dot planet to deduce its properties as it rotates and orbits are more encouraging: the main obstacle will be to overcome the difficulty of correcting for the unknown and variable cloud cover. The possible application of a circular polarization signal that is unique to vegetation remains an intriguing possibility for remote sensing that requires further study.

  10. Tri-modal confocal mosaics detect residual invasive squamous cell carcinoma in Mohs surgical excisions.

    PubMed

    Gareau, Dan; Bar, Anna; Snaveley, Nicholas; Lee, Ken; Chen, Nathaniel; Swanson, Neil; Simpson, Eric; Jacques, Steve

    2012-06-01

    For rapid, intra-operative pathological margin assessment to guide staged cancer excisions, multimodal confocal mosaic scan image wide surgical margins (approximately 1 cm) with sub-cellular resolution and mimic the appearance of conventional hematoxylin and eosin histopathology (H&E). The goal of this work is to combine three confocal imaging modes: acridine orange fluorescence (AO) for labeling nuclei, eosin fluorescence (Eo) for labeling cytoplasm, and endogenous reflectance (R) for marking collagen and keratin. Absorption contrast is achieved by alternating the excitation wavelength: 488 nm (AO fluorescence) and 532 nm (Eo fluorescence). Superposition and false-coloring of these modes mimics H&E, enabling detection of cutaneous squamous cell carcinomas (SCC). The sum of mosaic Eo+R is false-colored pink to mimic the appearance of eosin, while the AO mosaic is false-colored purple to mimic the appearance of hematoxylin in H&E. In this study, mosaics of 10 Mohs surgical excisions containing invasive SCC, and five containing only normal tissue were subdivided for digital presentation equivalent to 4 × histology. Of the total 50 SCC and 25 normal sub-mosaics presented, two reviewers made two and three type-2 errors (false positives), respectively. Limitations to precisely mimic H&E included occasional elastin staining by AO. These results suggest that confocal mosaics may effectively guide staged SCC excisions in skin and other tissues. PMID:22734774

  11. Tri-modal confocal mosaics detect residual invasive squamous cell carcinoma in Mohs surgical excisions

    NASA Astrophysics Data System (ADS)

    Gareau, Dan; Bar, Anna; Snaveley, Nicholas; Lee, Ken; Chen, Nathaniel; Swanson, Neil; Simpson, Eric; Jacques, Steve

    2012-06-01

    For rapid, intra-operative pathological margin assessment to guide staged cancer excisions, multimodal confocal mosaic scan image wide surgical margins (approximately 1 cm) with sub-cellular resolution and mimic the appearance of conventional hematoxylin and eosin histopathology (H&E). The goal of this work is to combine three confocal imaging modes: acridine orange fluorescence (AO) for labeling nuclei, eosin fluorescence (Eo) for labeling cytoplasm, and endogenous reflectance (R) for marking collagen and keratin. Absorption contrast is achieved by alternating the excitation wavelength: 488 nm (AO fluorescence) and 532 nm (Eo fluorescence). Superposition and false-coloring of these modes mimics H&E, enabling detection of cutaneous squamous cell carcinomas (SCC). The sum of mosaic Eo+R is false-colored pink to mimic the appearance of eosin, while the AO mosaic is false-colored purple to mimic the appearance of hematoxylin in H&E. In this study, mosaics of 10 Mohs surgical excisions containing invasive SCC, and five containing only normal tissue were subdivided for digital presentation equivalent to 4× histology. Of the total 50 SCC and 25 normal sub-mosaics presented, two reviewers made two and three type-2 errors (false positives), respectively. Limitations to precisely mimic H&E included occasional elastin staining by AO. These results suggest that confocal mosaics may effectively guide staged SCC excisions in skin and other tissues.

  12. Historical perspective and modern applications of Attenuated Total Reflectance-Fourier Transform Infrared Spectroscopy (ATR-FTIR).

    PubMed

    Blum, Marc-Michael; John, Harald

    2012-01-01

    Vibrational spectroscopy has a long history as an important spectroscopic method in chemical and pharmaceutical analysis. Instrumentation for infrared (IR) spectroscopy was revolutionized by the introduction of Fourier Transform Infrared (FTIR) spectrometers. In addition, easier sampling combined with better sample-to-sample reproducibility and user-to-user spectral variation became available with attenuated total reflectance (ATR) probes and their application for in situ IR spectroscopy. These innovations allow many new applications in chemical and pharmaceutical analysis, such as the use of IR spectroscopy in Process Analytical Chemistry (PAC), the quantitation of drugs in complex matrix formulations, the analysis of protein binding and function and in combination with IR microscopy to the emergence of IR imaging technologies. The use of ATR-FTIR instruments in forensics and first response to 'white powder' incidents is also discussed. A short overview is given in this perspective article with the aim to renew and intensify interest in IR spectroscopy. PMID:22113892

  13. Critical Reflectance Derived from MODIS: Application for the Retrieval of Aerosol Absorption over Desert Regions

    NASA Technical Reports Server (NTRS)

    Wells, Kelley C.; Martins, J. Vanderlei; Remer, Lorraine A.; Kreidenweis, Sonia M.; Stephens, Graeme L.

    2012-01-01

    Aerosols are tiny suspended particles in the atmosphere that scatter and absorb sunlight. Smoke particles are aerosols, as are sea salt, particulate pollution and airborne dust. When you look down at the earth from space sometimes you can see vast palls of whitish smoke or brownish dust being transported by winds. The reason that you can see these aerosols is because they are reflecting incoming sunlight back to the view in space. The reason for the difference in color between the different types of aerosol is that the particles arc also absorbing sunlight at different wavelengths. Dust appears brownish or reddish because it absorbs light in the blue wavelengths and scatters more reddish light to space, Knowing how much light is scattered versus how much is absorbed, and knowin that as a function of wavelength is essential to being able to quantify the role aerosols play in the energy balance of the earth and in climate change. It is not easy measuring the absorption properties of aerosols when they are suspended in the atmosphere. People have been doing this one substance at a time in the laboratory, but substances mix when they are in the atmosphere and the net absorption effect of all the particles in a column of air is a goal of remote sensing that has not yet been completely successful. In this paper we use a technique based on observing the point at which aerosols change from brightening the surface beneath to darkening it. If aerosols brighten a surface. they must scatter more light to space. If they darken the surface. they must be absorbing more. That cross over point is called the critical reflectance and in this paper we show that critical reflectance is a monotonic function of the intrinsic absorption properties of the particles. This parameter we call the single scattering albedo. We apply the technique to MODIS imagery over the Sahara and Sahel regions to retrieve the single scattering albedo in seven wavelengths, compare these retrievals to ground-based retrievals from AERONET instruments and compute error bars on each retrieval. The results show that we can retrieve single scattering albedo for pure dust to within +/-0.02 and mixtures of dust and smoke to within +/-0.03. No other space based instrument has achieved a retrieval of single scattering albedo that spans the spectrum from 0.47 microns to 2.13 microns and produces regional maps of aerosol absorption showing gradients and changes. Applied in a more operational fashion, such information will narrow uncertainties in estimating aerosol forcing on climate.

  14. Retrieving the optical parameters of biological tissues using diffuse reflectance spectroscopy and Fourier series expansions. I. theory and application

    PubMed Central

    Muñoz Morales, Aarón A.; Vázquez y Montiel, Sergio

    2012-01-01

    The determination of optical parameters of biological tissues is essential for the application of optical techniques in the diagnosis and treatment of diseases. Diffuse Reflection Spectroscopy is a widely used technique to analyze the optical characteristics of biological tissues. In this paper we show that by using diffuse reflectance spectra and a new mathematical model we can retrieve the optical parameters by applying an adjustment of the data with nonlinear least squares. In our model we represent the spectra using a Fourier series expansion finding mathematical relations between the polynomial coefficients and the optical parameters. In this first paper we use spectra generated by the Monte Carlo Multilayered Technique to simulate the propagation of photons in turbid media. Using these spectra we determine the behavior of Fourier series coefficients when varying the optical parameters of the medium under study. With this procedure we find mathematical relations between Fourier series coefficients and optical parameters. Finally, the results show that our method can retrieve the optical parameters of biological tissues with accuracy that is adequate for medical applications. PMID:23082281

  15. Reflections on the development and application of FISH whole chromosome painting.

    PubMed

    Tucker, James D

    2015-01-01

    This review describes my personal reflections on the development of whole chromosome painting using fluorescence in situ hybridization and how my laboratory applied the technology in humans and in animal models. The trials and triumphs of the early years are emphasized, along with some of the scientific surprises that were encountered along the way. Scientific issues that my laboratory addressed using chromosome painting technologies are summarized and related to questions in radiation dosimetry, chemical clastogenesis, translocation persistence, and translocation frequencies in unexposed people. A description is provided of scientific controversies that were encountered and how they were resolved. I hope this paper will encourage young scientists to follow their passions and pursue their scientific dreams even if the task seems daunting and the circumstances appear exceedingly difficult. In my case the journey has been challenging, exciting, and richly rewarding on many levels. PMID:25795112

  16. Total reflection X-ray fluorescence and archaeometry: Application in the Argentinean cultural heritage

    NASA Astrophysics Data System (ADS)

    Vázquez, Cristina; Albornoz, Ana; Hajduk, Adam; Elkin, Dolores; Custo, Graciela; Obrustky, Alba

    2008-12-01

    Archaeometry is an interdisciplinary research area involved in the development and use of scientific methods in order to answer questions concerned with the human history. In this way the knowledge of archaeological objects through advanced chemical and physical analyses permits a better preservation and conservation of the cultural heritage and also reveals materials and technologies used in the past. In this sense, analytical techniques play an important role in order to provide chemical information about cultural objects. Considering the non destructive characteristic of this study, analytical techniques must be adequate in order to prevent any alteration or damage and in addition to allow the conservation of their integrity. Taking into account the irreplaceable character of the archaeological and artistic materials considered in this study, analytical techniques must be adequate in order to prevent any alteration or damage and in addition to allow the conservation of their integrity. Total Reflection X-ray Fluorescence Spectrometry as a geometric variant of conventional X-ray fluorescence is a proved microanalytical technique considering the small amount of sample required for the analysis. A few micrograms are enough in order to reveal valuable information about elemental composition and in this context it is highly recommended for artwork studies. In this paper a case study is presented in which Total Reflection X-Ray Fluorescence Spectrometry has been successfully employed in the archaeometry field. Examples from Argentinean cultural heritage sites related with the determination of pigments in paintings on canvas and in rock sites as well as in underwater archaeology research are shown.

  17. A comparision between rapid Golgi and Golgi-Cox impregnation methods for 3-D reconstruction of neurons at the confocal scanning laser microscope.

    PubMed

    Castano, P; Gioia, M; Barajon, I; Rumio, C; Miani, A

    1995-01-01

    We utilized two widely used impregnation methods, the silver "rapid Golgi" and the mercuric Golgi-Cox methods, for three-dimensional (3-D) reconstruction of neurons at the confocal scanning laser microscope (CSLM), to determine which of them was more suitable for this application. The Golgi-Cox method is the most consistent arid the cleanest procedure with respect to the "rapid Golgi" one which always produces samples with scattered reflective granules that interfere with the image formation at the CSLM. The interneuronal tissue in the case of Golgi-Cox impregnated specimens (i.e. the non-impregnated tissue among impregnated neurons) contributes less to the decrease of reflected light during z-sectioning than in the case of "rapid Golgi" impregnation, but the mercury impregnated samples reflect less than the silver impregnated ones. Owing to the necessity during deep z-scanning to adjust the sensitivity of the CLSM detector the acquisition of images from the deeper planes of the sample may be difficult. In our opinion the "sandwich" mounting of the specimen between two coverslips is indispensable in order to make it possible to scan it from both sides and, thus reduce the penetration in the sample and the consequent distortion of the image. Neither of the impregnation methods used is completely suitable for CLSM observations due both to their intrinsic limitations and to those imposed by the sample thickness. PMID:11322342

  18. Three-dimensional in vivo imaging by a handheld dual-axes confocal microscope

    PubMed Central

    Ra, Hyejun; Piyawattanametha, Wibool; Mandella, Michael J.; Hsiung, Pei-Lin; Hardy, Jonathan; Wang, Thomas D.; Contag, Christopher H.; Kino, Gordon S.; Solgaard, Olav

    2008-01-01

    We present a handheld dual-axes confocal microscope that is based on a two-dimensional microelectromechanical systems (MEMS) scanner. It performs reflectance and fluorescence imaging at 488 nm wavelength, with three-dimensional imaging capability. The fully packaged microscope has a diameter of 10 mm and acquires images at 4 Hz frame rate with a maximum field of view of 400 ?m × 260 ?m. The transverse and axial resolutions of the handheld probe are 1.7 ?m and 5.8 ?m, respectively. Capability to perform real time small animal imaging is demonstrated in vivo in transgenic mice. PMID:18545427

  19. Spectrally encoded slit confocal microscopy using a wavelength-swept laser

    NASA Astrophysics Data System (ADS)

    Kim, Soocheol; Hwang, Jaehyun; Heo, Jung; Ryu, Suho; Lee, Donghak; Kim, Sang-Hoon; Oh, Seung Jae; Joo, Chulmin

    2015-03-01

    We present an implementation of spectrally encoded slit confocal microscopy. The method employs a rapid wavelength-swept laser as the light source and illuminates a specimen with a line focus that scans through the specimen as the wavelength sweeps. The reflected light from the specimen is imaged with a stationary line scan camera, in which the finite pixel height serves as a slit aperture. This scanner-free operation enables a simple and cost-effective implementation in a small form factor, while allowing for the three-dimensional imaging of biological samples.

  20. Electrostatically driven micromirrors for a miniaturized confocal laser scanning microscope

    NASA Astrophysics Data System (ADS)

    Hofmann, Ulrich; Muehlmann, Sascha; Witt, Martin; Doerschel, Klaus; Schuetz, Rijk; Wagner, Bernd

    1999-09-01

    A compact two-mirror microscanner has been fabricated to build the central part of a miniaturized confocal laser scanning microscope. This microscope shall be mounted at the tip of an endoscope to provide high resolution imaging for medical diagnostics. In order to achieve a resolution of 500 X 500 image elements large scan angles and also large mirror dimensions have to be realized within a spatially strong limited housing. While bulk silicon technology on the one hand enables fabrication of micromirrors with nearly ideal elastical behavior, those actuators on the other hand often are too fragile for a lot of applications. This paper describes the design, fabrication and assembling of electrostatically driven torsional micromirrors that meet the requirements of fast two-dimensional scanning with high angular precision over large scan angles, compact design and also high shock resistance. This is achieved with the combination of bulk silicon technology with metal surface micromachining. Besides medical diagnostics these microscanners can be used in a wider range of applications such as displays, two-dimensional barcode scanning, multiplexing of fiber optics, etc.

  1. Confocal supercritical angle microscopy for cell membrane imaging.

    PubMed

    Sivankutty, Siddharth; Barroca, Thomas; Mayet, Céline; Dupuis, Guillaume; Fort, Emmanuel; Lévêque-Fort, Sandrine

    2014-02-01

    We demonstrate subwavelength sectioning on biological samples with a conventional confocal microscope. This optical sectioning is achieved by the phenomenon of supercritical angle fluorescence, 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 modification on the detection channel. Confocal-supercritical angular fluorescence microscopy would be a powerful tool to achieve high-resolution surface imaging, especially for membrane imaging in biological samples. PMID:24487864

  2. Applications of reflection seismics to mapping coal-seam structure and discontinuities

    SciTech Connect

    Dobecki, T.L.; Bartel, L.C.

    1981-01-01

    As a means of demonstrating the effectiveness of reflection seismology in determining continuity of coal seams, three US field projects are reviewed. The three projects involve coals of varied thickness (2 to 14 m) and age (Pennsylvanian to Eocene) from three coal areas of the US (Pennsylvania, Wyoming, and Washington). Each projet also employed its own particular seismic technique, recording system, and seismic energy source although all are considered state-of-the-art, high resolution, digital seismic surveys. Project 1 (thin, Pennsylvania coal) sought detection of sand channels using dynamite and standard in-line (2-D) seismic technique. Project 2 (thick, Wyoming underground coal gasification) involved a gas-explosion (Dinoseis) source with areal (3-D) acquisition methods. Project 3 (thick Washington underground coal gasification) employed a shotgun-type source and standard in-line methods. Data processing was handled by different contractors for each project. Each project was successful in accomplishing its own particular objective; however, data quality and interpretation seem to be more a function of thickness of the target seam, complexity of the overburden, and processing contractor than a seismic source, acquisition scheme (2-D versus 3-D), or recording instrumentation.

  3. Reflections on clinical applications of yoga in voice therapy with MTD.

    PubMed

    Moore, Carmelle

    2012-12-01

    This paper explores the application of modified yoga techniques, as an adjunct to voice therapy, by a speech pathologist who is also a yoga teacher. Yoga practices, with effects that may be short-term, are not considered a substitute for comprehensive and integrated somatic retraining systems (such as the Alexander Technique or Feldenkrais ATM). However, when yoga is conducted emphasizing kinaesthetic and proprioceptive awareness, the client may achieve an 'awareness state' that facilitates the learning of vocal remediation techniques (for example, by more easily 'tuning in' to the subtle sensations of supralaryngeal deconstriction). Core yoga elements and clinical applications are identified. The potential benefits and considerations when using yoga as an adjunct to the treatment of muscle tension dysphonia (MTD) are explored. PMID:23137146

  4. Confocal Raman microscopy to monitor extracellular matrix during dental pulp stem cells differentiation

    NASA Astrophysics Data System (ADS)

    Salehi, Hamideh; Collart-Dutilleul, Pierre-Yves; Gergely, Csilla; Cuisinier, Frédéric J. G.

    2015-07-01

    Regenerative medicine brings promising applications for mesenchymal stem cells, such as dental pulp stem cells (DPSCs). Confocal Raman microscopy, a noninvasive technique, is used to study osteogenic differentiation of DPSCs. Integrated Raman intensities in the 2800 to 3000 cm-1 region (C-H stretching) and the 960 cm-1 peak (?1 PO43-) were collected (to image cells and phosphate, respectively), and the ratio of two peaks 1660 over 1690 cm-1 (amide I bands) to measure the collagen cross-linking has been calculated. Raman spectra of DPSCs after 21 days differentiation reveal several phosphate peaks: ?1 (first stretching mode) at 960 cm-1, ?2 at 430 cm-1, and ?4 at 585 cm-1 and collagen cross-linking can also be calculated. Confocal Raman microscopy enables monitoring osteogenic differentiation in vitro and can be a credible tool for clinical stem cell based research.

  5. Evaluation of human sclera after femtosecond laser ablation using two photon and confocal microscopy

    PubMed Central

    Sun, Hui; Kurtz, Ronald

    2012-01-01

    Abstract. Glaucoma is the second-leading cause of blindness worldwide and is often associated with elevated intraocular pressure (IOP). Partial thickness intrascleral channels can be created with a femtosecond laser operating at a wavelength of 1700 nm. Such channels have the potential to increase outflow facility and reduce elevated IOP. Analysis of the dimensions and location of these channels is important in understanding their effects. We describe the application of two-photon microscopy and confocal microscopy for noninvasive imaging of the femtosecond laser created partial-thickness scleral channels in human cadaver eyes. High-resolution images, hundreds of microns deep in the sclera, were obtained to allow determination of the shape and dimension of such channels. This demonstrates that concept of integrating femtosecond laser surgery, and two-photon and confocal imaging has the future potential for image-guided high-precision surgery in transparent and translucent tissue. PMID:23224172

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

    NASA Astrophysics Data System (ADS)

    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 ?1 PO4 3- (first vibrational mode) at 960cm-1 and ?2 PO4 3- at 430cm-1 and ?4 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.

  7. Evaluation of human sclera after femtosecond laser ablation using two photon and confocal microscopy

    NASA Astrophysics Data System (ADS)

    Sun, Hui; Kurtz, Ronald; Juhasz, Tibor

    2012-08-01

    Glaucoma is the second-leading cause of blindness worldwide and is often associated with elevated intraocular pressure (IOP). Partial thickness intrascleral channels can be created with a femtosecond laser operating at a wavelength of 1700 nm. Such channels have the potential to increase outflow facility and reduce elevated IOP. Analysis of the dimensions and location of these channels is important in understanding their effects. We describe the application of two-photon microscopy and confocal microscopy for noninvasive imaging of the femtosecond laser created partial-thickness scleral channels in human cadaver eyes. High-resolution images, hundreds of microns deep in the sclera, were obtained to allow determination of the shape and dimension of such channels. This demonstrates that concept of integrating femtosecond laser surgery, and two-photon and confocal imaging has the future potential for image-guided high-precision surgery in transparent and translucent tissue.

  8. Optical oblique-incidence reflectivity difference microscopy: Application to label-free detection of reactions in biomolecular microarrays

    NASA Astrophysics Data System (ADS)

    Landry, James Paul

    2008-04-01

    Biomolecular microarrays have emerged as a leading technology for high-throughput in vitro assays in genomics and proteomics. Microarrays contain 100 to 100,000 distinct biomolecular features immobilized on a substrate at high density, enabling parallel assays of entire biomolecular systems or screens of large biomolecular libraries on a single glass slide. Microarrays are typically detected by reacting immobilized targets with fluorescently-labeled probes. For many biomolecules, particularly structurally and functionally diverse proteins, modification with labeling-agents can alter their function. For this reason, it is important to develop label-free microarray detection technology to complement standard fluorescence-based detection. In this dissertation, I report my research into the development of optical oblique-incidence reflectivity difference (OI-RD) microscopy for application to high-throughput and label-free detection of biomolecular microarrays in end-point and real-time modalities. OI-RD is a versatile and sensitive form of nulling polarization-modulated ellipsometry. By reflecting light at oblique incidence from a surface, OI-RD measures changes in thickness and dielectric response of ultrathin molecular layers through disproportionate responses of s- and p-polarization reflectivities. In this dissertation I given an account of the engineering and operation of the first OI-RD microscopes and mathematical theory underpinning them. I then report experiments showing label-free OI-RD detection of DNA hybridization and antibody-antigen binding reactions in microarrays fabricated on standard chemically functionalized glass slides. The experiments demonstrate that: (1) The OI-RD signal quantifies biomolecular film properties, in particular, surface mass density, coverage, and orientation of biomolecules in the films. (2) The properties of targets, probes, and other biomolecular entities within the microarray can be measured throughout the microarray usage cycle. (3) A wide variety of biochemical reactions can be detected with a sensitivity and limit of detection comparable to or better than other label-free optical surface biosensors. (4) Microarrays of thousands of features can be end-point detected for screening applications or microarrays of hundreds of features can be detected in real-time for high-throughput biochemical kinetic analysis, with the potential to increase both of these capacities by at least an order of magnitude. (5) OI-RD is compatible with existing microarray fabrication materials and protocols because it is applicable to any optically flat surface.

  9. High-speed simulation of skin spectral reflectance based on an optical path-length matrix method and its application

    NASA Astrophysics Data System (ADS)

    Fujiwara, Izumi; Yamamoto, Satoshi; Yamauchi, Midori; Ogawa-Ochiai, Keiko; Nakaguchi, Toshiya; Tsumura, Norimichi

    2011-03-01

    In this paper, we propose optical path-length matrix method for high-speed simulation of photon migration in human skin. The optical path-length matrix is defined as the probability density distribution of optical pathlength in the skin. Generally, Monte Carlo simulation is used to simulate a skin reflectance, since it can simulate the reflectance accurately. However, it requires a huge computation time, thus this is not easily applicable in practical imaging system with large number of pixels. On the other hand, the proposed optical path-length matrix method achieves the simulation in shorter time. The skin model was assumed to be two-layered media of the epidermal and dermal layers. For obtaining the path-length matrix, photon migration in the model without any absorption was simulated only once by Monte Carlo simulation for each wavelength, and the probabilistic density histograms of the optical path-length at each layer were acquired and stored in the optical path-length matrix. Skin spectral reflectance for arbitrary absorption can be calculated easily by accumulating all combination of an element in the above pre-recomputed path-length matrix and absorption coefficient based on the Beer-Lambert law. Our proposed method was compared with the conventional Monte Carlo simulation. Computational time of the proposed method was approximately two minutes; while that of the conventional method was 15 hours. In addition, error margin of the proposed method was approximately less than 1.6%. This method would applied to skin spectral image analysis for skin chromophore quantification.

  10. Deep stroma investigation by confocal microscopy

    NASA Astrophysics Data System (ADS)

    Rossi, Francesca; Tatini, Francesca; Pini, Roberto; Valente, Paola; Ardia, Roberta; Buzzonetti, Luca; Canovetti, Annalisa; Malandrini, Alex; Lenzetti, Ivo; Menabuoni, Luca

    2015-03-01

    Laser assisted keratoplasty is nowadays largely used to perform minimally invasive surgery and partial thickness keratoplasty [1-3]. The use of the femtosecond laser enables to perform a customized surgery, solving the specific problem of the single patient, designing new graft profiles and partial thickness keratoplasty (PTK). The common characteristics of the PTKs and that make them eligible respect to the standard penetrating keratoplasty, are: the preservation of eyeball integrity, a reduced risk of graft rejection, a controlled postoperative astigmatism. On the other hand, the optimal surgical results after these PTKs are related to a correct comprehension of the deep stroma layers morphology, which can help in the identification of the correct cleavage plane during surgeries. In the last years some studies were published, giving new insights about the posterior stroma morphology in adult subjects [4,5]. In this work we present a study performed on two groups of tissues: one group is from 20 adult subjects aged 59 +/- 18 y.o., and the other group is from 15 young subjects, aged 12+/-5 y.o.. The samples were from tissues not suitable for transplant in patients. Confocal microscopy and Environmental Scanning Electron Microscopy (ESEM) were used for the analysis of the deep stroma. The preliminary results of this analysis show the main differences in between young and adult tissues, enabling to improve the knowledge of the morphology and of the biomechanical properties of human cornea, in order to improve the surgical results in partial thickness keratoplasty.

  11. Personal reflections on the highlights and changes in radiation and radioisotope measurement applications

    NASA Astrophysics Data System (ADS)

    Gardner, Robin P.; Lee, Kyoung O.

    2015-11-01

    This paper describes the recent changes that the authors have perceived in the use of radiation and radioisotope measurement applications. The first change is that due to the increased use of Monte Carlo simulation which has occurred from a normal evolutionary process. This is due in large part to the increased accuracy that is being obtained by the use of detector response functions (DRFs) and the simultaneous increased computational efficiency that has become available with these DRFs, the availability of a greatly improved weight windows variance reduction method, and the availability of inexpensive computer clusters. This first change is a happy one. The other change that is occurring is in response to recent terrorist activities. That change is the replacement or major change in the use of long-lived radioisotopes in radioisotope measurement and other radioisotope source applications. In general this can be done by improving the security of these radioisotope sources or by replacing them altogether by using machine sources of radiation. In either case one would like to preclude altogether or at least minimize the possibility of terrorists being able to obtain radioisotopes and use them for clandestine purposes.

  12. Solar Confocal Interferometers for Sub-Picometer-Resolution Spectral Filters

    NASA Technical Reports Server (NTRS)

    Gary, G. Allen; Pietraszewski, Chris; West, Edward A.; Dines, Terence C.

    2006-01-01

    The confocal Fabry-Perot interferometer allows sub-picometer spectral resolution of Fraunhofer line profiles. Such high spectral resolution is needed to keep pace with the higher spatial resolution of the new set of large-aperture solar telescopes. The line-of-sight spatial resolution derived for line profile inversions would then track the improvements of the transverse spatial scale provided by the larger apertures. The confocal interferometer's unique properties allow a simultaneous increase in both etendue and spectral power. Methods: We have constructed and tested two confocal interferometers. Conclusions: In this paper we compare the confocal interferometer with other spectral imaging filters, provide initial design parameters, show construction details for two designs, and report on the laboratory test results for these interferometers, and propose a multiple etalon system for future testing of these units and to obtain sub-picometer spectral resolution information on the photosphere in both the visible and near-infrared.

  13. Efficient Confocal Microscopy with a Dual-Wedge Scanner

    E-print Network

    Warger, William C., II

    Confocal microscopes achieve high spatial resolution by focusing both a light source and a detector to a single point with an objective having a high numerical aperture. In order to produce an image, it is then necessary ...

  14. Automated Biofilm Region Recognition And Morphology Quantification From Confocal Laser

    E-print Network

    Bouaynaya, Nidhal

    1 Automated Biofilm Region Recognition And Morphology Quantification From Confocal Laser Scanning of nosocomial infections. Its biofilm forming capability is an adaptation strategy utilized by many species, fully automated method of biofilm structure description with standardized pa- rameters

  15. WAVELENGTH AND ALIGNMENT TESTS FOR CONFOCAL SPECTRAL IMAGING SYSTEMS

    EPA Science Inventory

    Confocal spectral imaging (CSI) microscope systems now on the market delineate multiple fluorescent proteins, labels, or dyes within biological specimens by performing spectral characterizations. However, we find that some CSI present inconsistent spectral profiles of reference s...

  16. CALIBRATION AND VALIDATION OF CONFOCAL SPECTRAL IMAGING SYSTEMS

    EPA Science Inventory

    Confocal spectral imaging (CSI) microscope systems now on the market can perform spectral characterization of biological specimens containing fluorescent proteins, labels or dyes. Some CSI have been found to present inconsistent spectral characterizations within a particular syst...

  17. CONFOCAL LASER SCANNING MICROSCOPY OF APOPTOSIS IN WHOLE MOUSE OVARIES

    EPA Science Inventory

    Confocal Laser Scanning Microscopy of Apoptosis in Whole Mouse Ovaries. Robert M. Zucker Susan C. Jeffay and Sally D. Perreault Reproductive Toxicology Division, National Health and Environmental Effects Research Laboratory, U.S. Environmental Protection Agency, Research Triangle...

  18. Application Research on Nondestructive Testing Technology for Quality of Anchor Based on Elastic Wave Reflection Method

    NASA Astrophysics Data System (ADS)

    Xiao, G.; Zhou, L.

    2014-12-01

    Anchor technology has been widely used to reinforce slopes, underground caverns, deep excavations and the foundation of dams. It has attracted more and more attention of research worldwide on how to find a comfortable method to test the quality of anchoring systems. According to the characteristics of anchor systems, we set up the kinetic equations and mathematical models, then solved the models using ANSYS / LS-DYNA program. We found that the simulated mathematical models perfectly match the experimental data. By changing one of the parameters or the input conditions in the model, we were able to understand the characteristic response of excitation energy, excitation length, structural defects, rock quality, and different data acquisition methods. For short anchor systems (<10 m), we developed a method to extract the wave arrival times by obtaining the transient time domains instantaneously. It is well-known that obtaining the accurate wave arrival times from different structural interfaces within the anchor system is very difficult. But using our multi-parameter transient method, we could calculate the anchor length, the location of structural defect, and the grouting density. The obtained values were consistent with the actual experimental data. We also demonstrated that the kinetic energy of the collected waves from the bottom of the anchor had very close relationship with the grouting density and the position of the structural defects. For long anchors (> 60 m), mostly cable anchors, since little research could be followed, we started our research from designing the instrument, writing the program for data acquisition and analysis. We designed and developed novel sensors and preamplifiers. We used vertical stack technology to effectively enhance the weak signals from the deeper interfaces. In data processing, in addition to the traditional filter method, we also explored the current technology of signal processing such as true amplitude recovery and deconvolution, which enabled us to obtain improved signal to noise ratio and sensing precision. Through the above mentioned systematical studies, we developed a reliable nondestructive test method for both short and long anchors based on elastic wave reflection. This research is funded by National Natural Science Foundation of China (Grant No. 41202223)

  19. CCDiode: an optimal detector for laser confocal microscopes

    NASA Astrophysics Data System (ADS)

    Pawley, James B.; Blouke, Morley M.; Janesick, James R.

    1996-04-01

    The laser confocal microscope (LCM) is now an established research tool in biology and materials science. In biological applications, it is usually employed to detect the location of fluorescent market molecules and, under these conditions, signal levels from bright areas are often < 20 photons/pixel (from the specimen, assuming a standard 512 X 768, 1 sec. scan). Although this data rate limits the speed at which information can be derived from the specimen, saturation of the fluorophor, photobleaching of the dye, and phototoxicity prevent it being increased. Currently, most LCMs use photomultiplier tubes (PMT, QE equals 1 - 30% 400 - 900 nm). By contrast, rear-illuminated, scientific charge-coupled devices (CCD) now routinely readout the signal from square sensors approximately 30 micrometers on a side with a QE of 80 - 90%, a noise of only +/- 3 e-/pix and with no multiplicative noise. For this reason, in 1989, one of us (JJ) developed a rear-illuminated, single-channel Si sensor, called the Turbodiode, employing some of the sophisticated readout techniques used to measure charge in a scientific CCD. We are now extending this work to a device in which a single 36 X 36 micrometers sensor is read out through a low-noise FET charge amplifier with a reset circuit and then passed to a correlated, double-sampling digitizer. To maintain the desired +/- 3 e noise level at the relatively high data rate of 1 MHz, our new device utilizes 64 separate readout amplifier/digitizer systems, operating in sequence. The resulting detector is more compact, efficient and reliable than the PMT it replaces but as its sensitive area is smaller than that of a PMT, it will require auxiliary optics when used with any LCM having a large (mm) pinhole. As the signal light is parallel, a simple lens mounted axially and with the CCDiode at its focus would suffice. Future versions may use 3 X 3 or 5 X 5 arrays of sensors to `track' the confocal spot as it is deflected by inhomogeneities of the specimen, change its effective size or shape or detect system misalignment.

  20. Confocal laser endomicroscopy for diagnosing lung cancer in vivo.

    PubMed

    Fuchs, Florian S; Zirlik, Sabine; Hildner, Kai; Schubert, Juergen; Vieth, Michael; Neurath, Markus F

    2013-06-01

    Confocal laser endomicroscopy is a novel endoscopic technique that may allow imaging of living cells in lung tissue in vivo. We assessed the potential of this technique for the detection of histology during screening bronchoscopy for lung cancer. 32 patients with suspected malignancies underwent bronchoscopy with endomicroscopy using acriflavine hydrochloride. Standardised areas and localised lesions were analysed by in vivo confocal imaging during bronchoscopy and biopsies were taken. Confocal images were graded and correlated prospectively with conventional histology from biopsies. Acriflavine hydrochloride yielded high-quality confocal images and strongly labelled airway epithelial cells. No side-effects were noted. 75,522 confocal images from 56 different locations were compared prospectively with histological data from biopsy specimens. Endomicroscopy allowed subsurface imaging with detailed analysis of cellular and subcellular structures. Neoplastic changes could be predicted with high accuracy (sensitivity 96.0%, specificity 87.1%, accuracy 91.0%). Confocal laser endomicroscopy with acriflavine is a novel diagnostic tool for the analysis of living cells during bronchoscopy and permits virtual histology of neoplastic changes in the airways with high accuracy. This technique may enable the rapid diagnosis of neoplasia during ongoing endoscopy in patients with suspected lung cancer. PMID:22997220

  1. Confocal fluorescence microscopy for detection of cervical preneoplastic lesions

    NASA Astrophysics Data System (ADS)

    Sheikhzadeh, Fahime; Ward, Rabab K.; Carraro, Anita; Chen, Zhaoyang; van Niekerk, Dirk; MacAulay, Calum; Follen, Michele; Lane, Pierre; Guillaud, Martial

    2015-03-01

    We examined and established the potential of ex-vivo confocal fluorescence microscopy for differentiating between normal cervical tissue, low grade Cervical Intraepithelial Neoplasia (CIN1), and high grade CIN (CIN2 and CIN3). Our objectives were to i) use Quantitative Tissue Phenotype (QTP) analysis to quantify nuclear and cellular morphology and tissue architecture in confocal microscopic images of fresh cervical biopsies and ii) determine the accuracy of high grade CIN detection via confocal microscopy. Cervical biopsy specimens of colposcopically normal and abnormal tissues obtained from 15 patients were evaluated by confocal fluorescence microscopy. Confocal images were analyzed and about 200 morphological and architectural features were calculated at the nuclear, cellular, and tissue level. For the purpose of this study, we used four features to delineate disease grade including nuclear size, cell density, estimated nuclear-cytoplasmic (ENC) ratio, and the average of three nearest Delaunay neighbors distance (3NDND). Our preliminary results showed ENC ratio and 3NDND correlated well with histopathological diagnosis. The Spearman correlation coefficient between each of these two features and the histopathological diagnosis was higher than the correlation coefficient between colposcopic appearance and histopathological diagnosis. Sensitivity and specificity of ENC ratio for detecting high grade CIN were both equal to 100%. QTP analysis of fluorescence confocal images shows the potential to discriminate high grade CIN from low grade CIN and normal tissues. This approach could be used to help clinicians identify HGSILs in clinical settings.

  2. Axial scanning in confocal microscopy employing adaptive lenses (CAL).

    PubMed

    Koukourakis, Nektarios; Finkeldey, Markus; Stürmer, Moritz; Leithold, Christoph; Gerhardt, Nils C; Hofmann, Martin R; Wallrabe, Ulrike; Czarske, Jürgen W; Fischer, Andreas

    2014-03-10

    In this paper we analyze the capability of adaptive lenses to replace mechanical axial scanning in confocal microscopy. The adaptive approach promises to achieve high scan rates in a rather simple implementation. This may open up new applications in biomedical imaging or surface analysis in micro- and nanoelectronics, where currently the axial scan rates and the flexibility at the scan process are the limiting factors. The results show that fast and adaptive axial scanning is possible using electrically tunable lenses but the performance degrades during the scan. This is due to defocus and spherical aberrations introduced to the system by tuning of the adaptive lens. These detune the observation plane away from the best focus which strongly deteriorates the axial resolution by a factor of ~2.4. Introducing balancing aberrations allows addressing these influences. The presented approach is based on the employment of a second adaptive lens, located in the detection path. It enables shifting the observation plane back to the best focus position and thus creating axial scans with homogeneous axial resolution. We present simulated and experimental proof-of-principle results. PMID:24663938

  3. Confocal Brillouin microscopy for three-dimensional mechanical imaging

    PubMed Central

    Scarcelli, Giuliano; Yun, Seok Hyun

    2009-01-01

    Acoustically induced inelastic light scattering, first reported in 1922 by Brillouin1, allows non-contact, direct readout of the viscoelastic properties of a material and has widely been investigated for material characterization2, structural monitoring3 and environmental sensing4. Extending the Brillouin technique from point sampling spectroscopy to imaging modality5 would open up new possibilities for mechanical imaging, but has been challenging because rapid spectrum acquisition is required. Here, we demonstrate a confocal Brillouin microscope based on a fully parallel spectrometer—a virtually imaged phased array—that improves the detection efficiency by nearly 100-fold over previous approaches. Using the system, we show the first cross-sectional Brillouin imaging based on elastic properties as the contrast mechanism and monitor fast dynamic changes in elastic modulus during polymer crosslinking. Furthermore, we report the first in situ biomechanical measurement of the crystalline lens in a mouse eye. These results suggest multiple applications of Brillouin microscopy in biomedical and biomaterial science. PMID:19812712

  4. Phase relief imaging with confocal laser scanning system

    NASA Astrophysics Data System (ADS)

    Peng, Tong; Xie, Hao; Ding, Yichen; Xi, Peng

    2013-02-01

    Confocal laser scanning microscopy (CLSM) has become one of the most important biomedical research tools today due to its noninvasive and 3-D abilities. It enables imaging in living tissue with better resolution and contrast, and plays a growing role among microscopic techniques utilized for investigating numerous biological problems. In some cases, the sample was phase-sensitive, thus we introduce a novel method named laser oblique scanning optical microscopy (LOSOM) which could obtain a relief image in transparent sample directly. Through the LOSOM system, mouse kidney and HeLa cells sample were imaged and 10x, 20x and 40x magnify objective imaging results were realized respectively. Also, we compared the variation of pinhole size versus imaging result. One major parameters of LOSOM is the distance between fluorescence medium and the sample. Previously, this distance was set to 1.2 mm, which is the thickness of the slide. The experiment result showed that decreasing d can increase the signal level for LOSOM phase-relief imaging. We have also demonstrated the application of LOSOM in absorption imaging modality, when the specimen is non-transparent.

  5. Interfacial shape and contact-angle measurement of transparent samples with confocal interference microscopy.

    PubMed

    Fischer, D G; Ovryn, B

    2000-04-01

    A model has been developed that predicts the effective optical path through a thick, refractive specimen on a reflective substrate, as measured with a scanning confocal interference microscope equipped with a high-numerical-aperture objective. Assuming that the effective pinhole of the confocal microscope has an infinitesimal diameter, only one ray in the illumination bundle (the magic ray) contributes to the differential optical path length (OPL). A pinhole with finite diameter, however, allows rays within a small angular cone centered on the magic ray to contribute to the OPL. The model was incorporated into an iterative algorithm that allows the measured phase to be corrected for refractive errors by use of an a priori estimate of the sample profile. The algorithm was validated with a reflected-light microscope equipped with a phase-shifting laser-feedback interferometer to measure the interface shape and the 68 degrees contact angle of a silicone-oil drop on a coated silicon wafer. PMID:18064085

  6. Application of Hapke photometric model to three geologic surfaces using PARABOLA bidirectional reflection data

    NASA Technical Reports Server (NTRS)

    Shepard, Michael K.; Arvidson, Raymond E.; Deering, Donald W.

    1991-01-01

    The Geologic Remote Sensing Field Experiment (GRSFE) was conducted in July and September of 1989 to collect data with both ground and airborne instrumentation. A major objective of GRSFE was to collect data which could be used to test radiative transfer models for the extraction of composition and textural surface properties from remotely acquired data. Reported here are the initial results from an application of the Hapke photometric model, using data from the Portable Apparatus for Remote Acquisition of Bidirectional Observations of Land and Atmosphere (PARABOLA), a ground based radiometer with three spectral channels. PARABOLA data was collected in the Lunar Crater Volcanic Field in Nevada, specifically from the region of Lunar Lake, a playa. The Hapke model was found to be inadequate for three relatively common geologic surfaces (a clay-rich, hard packed surface with decimeter sized mudcracks; a cobble site, similar to a playa site, but strewn with basaltic cobbles and pebbles; and a surface mantled basalt lava flow). The model is not at fault; rather, the complexity of most geologic surfaces is not accounted for in the initial assumptions.

  7. Fibre optic confocal imaging (FOCI) for subsurface microscopy of the colon in vivo.

    PubMed Central

    Delaney, P M; King, R G; Lambert, J R; Harris, M R

    1994-01-01

    Fibre optic confocal imaging (FOCI) is a new type of microscopy which has been recently developed (Delaney et al. 1993). In contrast to conventional light microscopy, FOCI and other confocal techniques allow clear imaging of subsurface structures within translucent objects. However, unlike conventional confocal microscopes which are bulky (because of a need for accurate alignment of large components) FOCI allows the imaging end to be miniaturised and relatively mobile. FOCI is thus particularly suited for clear subsurface imaging of structures within living animals or subjects. The aim of the present study was to assess the suitability of using FOCI for imaging of subsurface structures within the colon, both in vitro (human and rat biopsies) and in vivo (in rats). Images were obtained in fluorescence mode (excitation 488 nm, detection above 515 nm) following topical application of fluorescein. By this technique the glandular structure of the colon was imaged. FOCI is thus suitable for subsurface imaging of the colon in vivo. Images Fig. 2 Fig. 3 PMID:8157487

  8. Super-resolution mapping of glutamate receptors in C. elegans by confocal correlated PALM

    PubMed Central

    Vangindertael, Jeroen; Beets, Isabel; Rocha, Susana; Dedecker, Peter; Schoofs, Liliane; Vanhoorelbeeke, Karen; Hofkens, Johan; Mizuno, Hideaki

    2015-01-01

    Photoactivated localization microscopy (PALM) is a super-resolution imaging technique based on the detection and subsequent localization of single fluorescent molecules. PALM is therefore a powerful tool in resolving structures and putative interactions of biomolecules at the ultimate analytical detection limit. However, its limited imaging depth restricts PALM mostly to in vitro applications. Considering the additional need for anatomical context when imaging a multicellular organism, these limitations render the use of PALM in whole animals difficult. Here we integrated PALM with confocal microscopy for correlated imaging of the C. elegans nervous system, a technique we termed confocal correlated PALM (ccPALM). The neurons, lying below several tissue layers, could be visualized up to 10??m deep inside the animal. By ccPALM, we visualized ionotropic glutamate receptor distributions in C. elegans with an accuracy of 20?nm, revealing super-resolution structure of receptor clusters that we mapped onto annotated neurons in the animal. Pivotal to our results was the TIRF-independent detection of single molecules, achieved by genetic regulation of labeled receptor expression and localization to effectively reduce the background fluorescence. By correlating PALM with confocal microscopy, this platform enables dissecting biological structures with single molecule resolution in the physiologically relevant context of whole animals. PMID:26323790

  9. Super-resolution mapping of glutamate receptors in C. elegans by confocal correlated PALM.

    PubMed

    Vangindertael, Jeroen; Beets, Isabel; Rocha, Susana; Dedecker, Peter; Schoofs, Liliane; Vanhoorelbeeke, Karen; Hofkens, Johan; Mizuno, Hideaki

    2015-01-01

    Photoactivated localization microscopy (PALM) is a super-resolution imaging technique based on the detection and subsequent localization of single fluorescent molecules. PALM is therefore a powerful tool in resolving structures and putative interactions of biomolecules at the ultimate analytical detection limit. However, its limited imaging depth restricts PALM mostly to in vitro applications. Considering the additional need for anatomical context when imaging a multicellular organism, these limitations render the use of PALM in whole animals difficult. Here we integrated PALM with confocal microscopy for correlated imaging of the C. elegans nervous system, a technique we termed confocal correlated PALM (ccPALM). The neurons, lying below several tissue layers, could be visualized up to 10 ?m deep inside the animal. By ccPALM, we visualized ionotropic glutamate receptor distributions in C. elegans with an accuracy of 20 nm, revealing super-resolution structure of receptor clusters that we mapped onto annotated neurons in the animal. Pivotal to our results was the TIRF-independent detection of single molecules, achieved by genetic regulation of labeled receptor expression and localization to effectively reduce the background fluorescence. By correlating PALM with confocal microscopy, this platform enables dissecting biological structures with single molecule resolution in the physiologically relevant context of whole animals. PMID:26323790

  10. Automated identification of neurons in 3D confocal datasets from zebrafish brainstem

    PubMed Central

    KAMALI, M.; DAY, L. J.; BROOKS, D. H.; ZHOU, X.; O’MALLEY, D. M.

    2009-01-01

    Summary Many kinds of neuroscience data are being acquired regarding the dynamic behaviour and phenotypic diversity of nerve cells. But as the size, complexity and numbers of 3D neuroanatomical datasets grow ever larger, the need for automated detection and analysis of individual neurons takes on greater importance. We describe here a method that detects and identifies neurons within confocal image stacks acquired from the zebrafish brainstem. The first step is to create a template that incorporates the location of all known neurons within a population – in this case the population of reticulospinal cells. Once created, the template is used in conjunction with a sequence of algorithms to determine the 3D location and identity of all fluorescent neurons in each confocal dataset. After an image registration step, neurons are segmented within the confocal image stack and subsequently localized to specific locations within the brainstem template – in many instances identifying neurons as specific, individual reticulospinal cells. This image-processing sequence is fully automated except for the initial selection of three registration points on a maximum projection image. In analysing confocal image stacks that ranged considerably in image quality, we found that this method correctly identified on average ~80% of the neurons (if we assume that manual detection by experts constitutes ‘ground truth’). Because this identification can be generated approximately 100 times faster than manual identification, it offers a considerable time savings for the investigation of zebrafish reticulospinal neurons. In addition to its cell identification function, this protocol might also be integrated with stereological techniques to enhance quantification of neurons in larger databases. Our focus has been on zebrafish brainstem systems, but the methods described should be applicable to diverse neural architectures including retina, hippocampus and cerebral cortex. PMID:19196418

  11. To see the unseeable: confocal miniprobes for routine microscopic imaging during endoscopy

    NASA Astrophysics Data System (ADS)

    Osdoit, A.; Lacombe, F.; Cavé, C.; Loiseau, S.; Peltier, E.

    2007-02-01

    Confocal fluorescence high resolution imaging during standard endoscopic procedures has been presented as a very promising tool to enhance patient care and physician practice by providing supplementary diagnostic information in real-time. The purpose of this paper is to show not only potential, but convincing results of endoscopic microscopy using a catheter-based approach. Mauna Kea Technologies' core technology, Cellvizio, delivers dynamic imaging at 12 frames/second using confocal miniprobes inserted through the operating channel of regular endoscopes. Cellvizio is composed of 3 parts including (a) a Laser Scanning Unit, (b) Confocal Miniprobe TM with the following characteristics: 5-15 ?m axial resolution, 2-5 ?m lateral resolution, 15-100 ?m depth of penetration, field of view of 600x500 ?m and (c) a software package with onthe- fly processing capabilities. With several tens of patients examined during routine GI endoscopy procedures, the most relevant clinical parameters could be assessed in a doubled-blinded fashion between the endoscopist and a pathologist and results showing very high accuracy in the differentiation of neoplasia from normal and hyperplastic tissue were obtained. In the field of pulmonology, the micro-autofluorescence properties of tissues could be assessed and structures never before accessed in vivo were observed. Cellvizio® may be useful to study bronchial remodeling in asthma and chronic obstructive pulmonary diseases. Using appropriate topical fluorescent dye, the Confocal Miniprobes may also make it possible to perform optical biopsy of precancerous and superficial bronchial cancers. Cellvizio® is as a new tool towards "targeted biopsies", leading to earlier, more reliable and cost effective diagnostic procedures. Other applications, specifically in molecular imaging are also made possible by the miniaturization of the probe (combination with biopsy needle for solid organs use or lymph node detection) and by the compatibility of the system with other imaging modalities (auto-fluorescence and narrow-band imaging endoscopy, MRI, PET, etc).

  12. Confocal mosaicing microscopy of human skin ex vivo: spectral analysis for digital staining to simulate histology-like appearance

    PubMed Central

    Bini, Jason; Spain, James; Nehal, Kishwer; Hazelwood, Vikki; DiMarzio, Charles; Rajadhyaksha, Milind

    2011-01-01

    Confocal mosaicing microscopy enables rapid imaging of large areas of fresh tissue, without the processing that is necessary for conventional histology. Mosaicing may offer a means to perform rapid histology at the bedside. A possible barrier toward clinical acceptance is that the mosaics are based on a single mode of grayscale contrast and appear black and white, whereas histology is based on two stains (hematoxylin for nuclei, eosin for cellular cytoplasm and dermis) and appears purple and pink. Toward addressing this barrier, we report advances in digital staining: fluorescence mosaics that show only nuclei, are digitally stained purple and overlaid on reflectance mosaics, which show only cellular cytoplasm and dermis, and are digitally stained pink. With digital staining, the appearance of confocal mosaics mimics the appearance of histology. Using multispectral analysis and color matching functions, red, green, and blue (RGB) components of hematoxylin and eosin stains in tissue were determined. The resulting RGB components were then applied in a linear algorithm to transform fluorescence and reflectance contrast in confocal mosaics to the absorbance contrast seen in pathology. Optimization of staining with acridine orange showed improved quality of digitally stained mosaics, with good correlation to the corresponding histology. PMID:21806269

  13. Confocal mosaicing microscopy of human skin ex vivo: spectral analysis for digital staining to simulate histology-like appearance.

    PubMed

    Bini, Jason; Spain, James; Nehal, Kishwer; Hazelwood, Vikki; DiMarzio, Charles; Rajadhyaksha, Milind

    2011-07-01

    Confocal mosaicing microscopy enables rapid imaging of large areas of fresh tissue, without the processing that is necessary for conventional histology. Mosaicing may offer a means to perform rapid histology at the bedside. A possible barrier toward clinical acceptance is that the mosaics are based on a single mode of grayscale contrast and appear black and white, whereas histology is based on two stains (hematoxylin for nuclei, eosin for cellular cytoplasm and dermis) and appears purple and pink. Toward addressing this barrier, we report advances in digital staining: fluorescence mosaics that show only nuclei, are digitally stained purple and overlaid on reflectance mosaics, which show only cellular cytoplasm and dermis, and are digitally stained pink. With digital staining, the appearance of confocal mosaics mimics the appearance of histology. Using multispectral analysis and color matching functions, red, green, and blue (RGB) components of hematoxylin and eosin stains in tissue were determined. The resulting RGB components were then applied in a linear algorithm to transform fluorescence and reflectance contrast in confocal mosaics to the absorbance contrast seen in pathology. Optimization of staining with acridine orange showed improved quality of digitally stained mosaics, with good correlation to the corresponding histology. PMID:21806269

  14. A dual modality fluorescence confocal and optical coherence tomography microendoscope

    NASA Astrophysics Data System (ADS)

    Makhlouf, Houssine; Rouse, Andrew R.; Gmitro, Arthur F.

    2010-02-01

    We demonstrate the implementation of a Fourier domain optical coherence tomography (OCT) imaging system incorporated into the optical train of a fluorescence confocal microendoscope. The slit-scanning confocal system has been presented previously and achieves 3?m lateral resolution and 25?m axial resolution over a field of view of 430?m. Its multi-spectral mode of operation captures images with 6nm average spectral resolution. To incorporate OCT imaging, a common-path interferometer is made with a super luminescent diode and a reference coverslip located at the distal end of the fiber bundle catheter. The infrared diode spectral width allows a theoretical OCT axial resolution of 12.9?m. Light from the reference and sample combine, and a diffraction grating produces a spectral interferogram on the same 2D CCD camera used for confocal microendoscopic imaging. OCT depth information is recovered by a Fourier transform along the spectral dispersion direction. Proper operation of the system scan mirrors allows rapid switching between confocal and OCT imaging modes. The OCT extension takes advantage of the slit geometry, so that a 2D image is acquired without scanning. Combining confocal and OCT imaging modalities provides a more comprehensive view of tissue and the potential to improve disease diagnosis. A preliminary bench-top system design and imaging results are presented.

  15. An efficient intelligent analysis system for confocal corneal endothelium images.

    PubMed

    Sharif, M S; Qahwaji, R; Shahamatnia, E; Alzubaidi, R; Ipson, S; Brahma, A

    2015-12-01

    A confocal microscope provides a sequence of images of the corneal layers and structures at different depths from which medical clinicians can extract clinical information on the state of health of the patient's cornea. A hybrid model based on snake and particle swarm optimisation (S-PSO) is proposed in this paper to analyse the confocal endothelium images. The proposed system is able to pre-process images (including quality enhancement and noise reduction), detect cells, measure cell densities and identify abnormalities in the analysed data sets. Three normal corneal data sets acquired using a confocal microscope, and three abnormal confocal endothelium images associated with diseases have been investigated in the proposed system. Promising results are presented and the performance of this system is compared with manual and two morphological based approaches. The average differences between the manual and the automatic cell densities calculated using S-PSO and two other morphological based approaches is 5%, 7% and 13% respectively. The developed system will be deployable as a clinical tool to underpin the expertise of ophthalmologists in analysing confocal corneal images. PMID:26386613

  16. A confocal microscope position sensor for micron-scale target alignment in ultra-intense laser-matter experiments

    NASA Astrophysics Data System (ADS)

    Willis, Christopher; Poole, Patrick L.; Akli, Kramer U.; Schumacher, Douglass W.; Freeman, Richard R.

    2015-05-01

    A diagnostic tool for precise alignment of targets in laser-matter interactions based on confocal microscopy is presented. This device permits precision alignment of targets within the Rayleigh range of tight focusing geometries for a wide variety of target surface morphologies. This confocal high-intensity positioner achieves micron-scale target alignment by selectively accepting light reflected from a narrow range of target focal planes. Additionally, the design of the device is such that its footprint and sensitivity can be tuned for the desired chamber and experiment. The device has been demonstrated to position targets repeatably within the Rayleigh range of the Scarlet laser system at The Ohio State University, where use of the device has provided a marked increase in ion yield and maximum energy.

  17. Development and Beam-Shape Analysis of an Integrated Fiber-Optic Confocal Probe for High-Precision Central Thickness Measurement of Small-Radius Lenses

    PubMed Central

    Sutapun, Boonsong; Somboonkaew, Armote; Amarit, Ratthasart; Chanhorm, Sataporn

    2015-01-01

    This work describes a new design of a fiber-optic confocal probe suitable for measuring the central thicknesses of small-radius optical lenses or similar objects. The proposed confocal probe utilizes an integrated camera that functions as a shape-encoded position-sensing device. The confocal signal for thickness measurement and beam-shape data for off-axis measurement can be simultaneously acquired using the proposed probe. Placing the probe’s focal point off-center relative to a sample’s vertex produces a non-circular image at the camera’s image plane that closely resembles an ellipse for small displacements. We were able to precisely position the confocal probe’s focal point relative to the vertex point of a ball lens with a radius of 2.5 mm, with a lateral resolution of 1.2 µm. The reflected beam shape based on partial blocking by an aperture was analyzed and verified experimentally. The proposed confocal probe offers a low-cost, high-precision technique, an alternative to a high-cost three-dimensional surface profiler, for tight quality control of small optical lenses during the manufacturing process. PMID:25871720

  18. Applicability of near-infrared reflectance spectroscopy (NIRS) for determination of crude protein content in cowpea (Vigna unguiculata) leaves

    PubMed Central

    Towett, Erick K; Alex, Merle; Shepherd, Keith D; Polreich, Severin; Aynekulu, Ermias; Maass, Brigitte L

    2013-01-01

    There is uncertainty on how generally applicable near-infrared reflectance spectroscopy (NIRS) calibrations are across genotypes and environments, and this study tests how well a single calibration performs across a wide range of conditions. We also address the optimization of NIRS to perform the analysis of crude protein (CP) content in a variety of cowpea accessions (n?=?561) representing genotypic variation as well as grown in a wide range of environmental conditions in Tanzania and Uganda. The samples were submitted to NIRS analysis and a predictive calibration model developed. A modified partial least-squares regression with cross-validation was used to evaluate the models and identify possible spectral outliers. Calibration statistics for CP suggests that NIRS can predict this parameter in a wide range of cowpea leaves from different agro-ecological zones of eastern Africa with high accuracy (R2cal?=?0.93; standard error of cross-validation?=?0.74). NIRS analysis improved when a calibration set was developed from samples selected to represent the range of spectral variability. We conclude from the present results that this technique is a good alternative to chemical analysis for the determination of CP contents in leaf samples from cowpea in the African context, as one of the main advantages of NIRS is the large number of compounds that can be measured at once in the same sample, thus substantially reducing the cost per analysis. The current model is applicable in predicting the CP content of young cowpea leaves for human nutrition from different agro-ecological zones and genetic materials, as cowpea leaves are one of the popular vegetables in the region. PMID:24804013

  19. Application of visible/near-infrared reflectance spectroscopy to uranium ore concentrates for nuclear forensic analysis and attribution.

    PubMed

    Klunder, Gregory L; Plaue, Jonathan W; Spackman, Paul E; Grant, Patrick M; Lindvall, Rachel E; Hutcheon, Ian D

    2013-09-01

    Uranium ore concentrates (UOCs) are produced at mining facilities from the various types of uranium-bearing ores using several processes that can include different reagents, separation procedures, and drying conditions. The final UOC products can consist of different uranium species, which are important to identify to trace interdicted samples back to their origins. Color has been used as a simple indicator; however, visual determination is subjective and no chemical information is provided. In this work, we report the application of near-infrared (NIR) spectroscopy as a non-contact, non-destructive method to rapidly analyze UOC materials for species and/or process information. Diffuse reflectance spectra from 350 to 2500 nm were measured from a number UOC samples that were also characterized by X-ray diffraction. Combination and overtone bands were used to identify the amine and hydroxyl-containing species, such as ammonium uranates or ammonium uranyl carbonate, while other uranium oxide species (e.g., uranium trioxide [UO3] and triuranium octoxide [U3O8]) exhibit absorption bands arising from crystal field effects and electronic transitions. Principal component analysis was used to classify the different UOC materials. PMID:24067636

  20. Seismogram synthesis for radially layered media using the generalized reflection/transmission coefficients method: Theory and applications to acoustic logging

    SciTech Connect

    Chen, X.; Quan, Y.; Harris, J.M.

    1996-07-01

    A new method based on generalized reflection and transmission coefficients is proposed to calculate the synthetic seismograms in radially multilayered media. This method can be used to efficiently simulate full waveform acoustic logs and crosswell seismic profiles in situations where one needs to consider borehole effects. The new formulation is tested by comparing the authors` numerical results with previous available work and shows excellent agreement. Because of the use of the normalized Hankel functions and the normalization factors, this new algorithm for computing seismograms is stable numerically even for high-frequency problems. To show the applicability of this new approach to full waveform sonic logging, they apply it to investigate the effects of complex invaded zones on the geometrical spreading and attenuation estimation for P-waves. They find that a damaged zone (its velocity is slower than the unperturbed formation velocity) exhibits a convergence effect on the P-waves, and a flushed zone (velocity is faster than the unperturbed formation velocity) exhibits a divergence effect on the P-waves.

  1. In vivo subsurface morphological and functional cellular and subcellular imaging of the gastrointestinal tract with confocal mini-microscopy

    PubMed Central

    Goetz, Martin; Memadathil, Beena; Biesterfeld, Stefan; Schneider, Constantin; Gregor, Sebastian; Galle, Peter R; Neurath, Markus F; Kiesslich, Ralf

    2007-01-01

    AIM: To evaluate a newly developed hand-held confocal probe for in vivo microscopic imaging of the complete gastrointestinal tract in rodents. METHODS: A novel rigid confocal probe (diameter 7 mm) was designed with optical features similar to the flexible endomicroscopy system for use in humans using a 488 nm single line laser for fluorophore excitation. Light emission was detected at 505 to 750 nm. The field of view was 475 ?m × 475 ?m. Optical slice thickness was 7 ?m with a lateral resolution of 0.7 ?m. Subsurface serial images at different depths (surface to 250 ?m) were generated in real time at 1024 × 1024 pixels (0.8 frames/s) by placing the probe onto the tissue in gentle, stable contact. Tissue specimens were sampled for histopathological correlation. RESULTS: The esophagus, stomach, small and large intestine and meso, liver, pancreas and gall bladder were visualised in vivo at high resolution in n = 48 mice. Real time microscopic imaging with the confocal mini-microscopy probe was easy to achieve. The different staining protocols (fluorescein, acriflavine, FITC-labelled dextran and L. esculentum lectin) each highlighted specific aspects of the tissue, and in vivo imaging correlated excellently with conventional histology. In vivo blood flow monitoring added a functional quality to morphologic imaging. CONCLUSION: Confocal microscopy is feasible in vivo allowing the visualisation of the complete GI tract at high resolution even of subsurface tissue structures. The new confocal probe design evaluated in this study is compatible with laparoscopy and significantly expands the field of possible applications to intra-abdominal organs. It allows immediate testing of new in vivo staining and application options and therefore permits rapid transfer from animal studies to clinical use in patients. PMID:17465494

  2. Spinning Disk Confocal Imaging of Neutrophil Migration in Zebrafish

    PubMed Central

    Lam, Pui-ying; Fischer, Robert S; Shin, William D.; Waterman, Clare M; Huttenlocher, Anna

    2014-01-01

    Live-cell imaging techniques have been substantially improved due to advances in confocal microscopy instrumentation coupled with ultrasensitive detectors. The spinning disk confocal system is capable of generating images of fluorescent live samples with broad dynamic range and high temporal and spatial resolution. The ability to acquire fluorescent images of living cells in vivo on a millisecond timescale allows the dissection of biological processes that have not previously been visualized in a physiologically relevant context. In vivo imaging of rapidly moving cells such as neutrophils can be technically challenging. In this chapter, we describe the practical aspects of imaging neutrophils in zebrafish embryos using spinning disk confocal microscopy. Similar setups can also be applied to image other motile cell types and signaling processes in translucent animals or tissues. PMID:24504955

  3. Two-photon fluorescence properties of curcumin as a biocompatible marker for confocal imaging

    NASA Astrophysics Data System (ADS)

    Kumar, Abhishek; Li, Lian; Chaturvedi, Akanksha; Brzostowski, Joseph; Chittigori, Joshna; Pierce, Susan; Samuelson, Lynne A.; Sandman, Daniel; Kumar, Jayant

    2012-05-01

    Two-photon (TP) fluorescence properties of an antioxidant and anti-tumor molecule, curcumin, were investigated. The two-photon absorption (TPA) action cross-section was measured in organic solvents and found to be 6 GM in tetrahydrofuran and 2 GM in dimethyl sulfoxide. The measured TPA cross-section is comparable to that of rhodamine 6G. One-photon and TP confocal microscopy has demonstrated that curcumin is internalized in cells and can be used for imaging applications. Our investigation indicates that curcumin is a viable biocompatible TP fluorescent marker.

  4. The Reflective Learning Continuum: Reflecting on Reflection

    ERIC Educational Resources Information Center

    Peltier, James W.; Hay, Amanda; Drago, William

    2005-01-01

    The importance of reflection to marketing educators is increasingly recognized. However, there is a lack of empirical research that considers reflection within the context of both the marketing and general business education literature. This article describes the use of an instrument that can be used to measure four identified levels of a…

  5. Confocal Raman imaging of crystalline an glassy materials

    SciTech Connect

    Bradley, N.L.; Morris, M.D.

    1995-12-31

    Spatial distribution of materials components can be measured by confocal Raman imaging. We describe a confocal line-imaging system in which the spectrograph entrance slit functions as a spatial filter. The instrument uses a scanning galvanometer mirror to generate uniform intensity line illumination. A flexure mount with better than 0.1 micrometer positioning accuracy moves the sample under the fixed optical system. The Raman scatter is collected and projected along the entrance slit of an axial transmissive spectrograph. A CCD collects spatially resolved spectra.

  6. Confocal laser endomicroscopy: technical status and current indications.

    PubMed

    Hoffman, A; Goetz, M; Vieth, M; Galle, P R; Neurath, M F; Kiesslich, R

    2006-12-01

    Confocal laser endomicroscopy is a newly introduced endoscopic tool that makes it possible to carry out confocal microscopic examination of the mucosal layer during ongoing endoscopy. Different types of tissue and diseases can be diagnosed immediately, facilitating early diagnosis of gastrointestinal cancer. Analysis of the in vivo microarchitecture is helpful in targeting biopsies to relevant areas. In addition, subsurface imaging can unmask microscopic diseases - (microscopic colitis) or bacterial infection ( HELICOBACTER PYLORI), for example. Molecular imaging is becoming feasible, and this will shortly open the door to new indications in gastrointestinal endoscopy (e.g., in vivo receptor analysis). PMID:17163333

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

    NASA Astrophysics Data System (ADS)

    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.

  8. Full-field interferometric confocal microscopy using a VCSEL array

    PubMed Central

    Redding, Brandon; Bromberg, Yaron; Choma, Michael A.; Cao, Hui

    2014-01-01

    We present an interferometric confocal microscope using an array of 1200 VCSELs coupled to a multimode fiber. Spatial coherence gating provides ~18,000 continuous virtual pinholes allowing an entire en face plane to be imaged in a snapshot. This approach maintains the same optical sectioning as a scanning confocal microscope without moving parts, while the high power of the VCSEL array (~5 mW per laser) enables high-speed image acquisition with integration times as short as 100 µs. Interferometric detection also recovers the phase of the image, enabling quantitative phase measurements and improving the contrast when imaging phase objects. PMID:25078199

  9. Full-field interferometric confocal microscopy using a VCSEL array.

    PubMed

    Redding, Brandon; Bromberg, Yaron; Choma, Michael A; Cao, Hui

    2014-08-01

    We present an interferometric confocal microscope using an array of 1200 vertical cavity surface emitting lasers (VCSELs) coupled to a multimode fiber. Spatial coherence gating provides ~18,000 continuous virtual pinholes, allowing an entire en face plane to be imaged in a snapshot. This approach maintains the same optical sectioning as a scanning confocal microscope without moving parts, while the high power of the VCSEL array (?5??mW per laser) enables high-speed image acquisition with integration times as short as 100 ?s. Interferometric detection also recovers the phase of the image, enabling quantitative phase measurements and improving the contrast when imaging phase objects. PMID:25078199

  10. Optimization of confocal laser induced fluorescence in a plasma.

    PubMed

    VanDervort, R; Elliott, D; McCarren, D; McKee, J; Soderholm, M; Sears, S; Scime, E

    2014-11-01

    Laser Induced Fluorescence (LIF) provides measurements of flow speed, temperature, and density of ions or neutrals in a plasma. Traditionally, a LIF measurement requires two ports on a plasma device; one for laser injection and one for emission collection. Proper alignment of LIF optics is time consuming and sensitive to mechanical vibration. We describe a confocal configuration for LIF that requires a single port and requires no alignment. The measurement location is scanned radially by physically moving the entire optical structure. Confocal LIF measurements are compared to traditional LIF measurements over the same radial range. PMID:25430315

  11. Optimization of confocal laser induced fluorescence in a plasma

    NASA Astrophysics Data System (ADS)

    VanDervort, R.; Elliott, D.; McCarren, D.; McKee, J.; Soderholm, M.; Sears, S.; Scime, E.

    2014-11-01

    Laser Induced Fluorescence (LIF) provides measurements of flow speed, temperature, and density of ions or neutrals in a plasma. Traditionally, a LIF measurement requires two ports on a plasma device; one for laser injection and one for emission collection. Proper alignment of LIF optics is time consuming and sensitive to mechanical vibration. We describe a confocal configuration for LIF that requires a single port and requires no alignment. The measurement location is scanned radially by physically moving the entire optical structure. Confocal LIF measurements are compared to traditional LIF measurements over the same radial range.

  12. An invertebrate embryologist's guide to routine processing of confocal images.

    PubMed

    von Dassow, George

    2014-01-01

    It is almost impossible to use a confocal microscope without encountering the need to transform the raw data through image processing. Adherence to a set of straightforward guidelines will help ensure that image manipulations are both credible and repeatable. Meanwhile, attention to optimal data collection parameters will greatly simplify image processing, not only for convenience but for quality and credibility as well. Here I describe how to conduct routine confocal image processing tasks, including creating 3D animations or stereo images, false coloring or merging channels, background suppression, and compressing movie files for display. PMID:24567209

  13. Confocal shift interferometry of coherent emission from trapped dipolar excitons

    SciTech Connect

    Repp, J.; Schinner, G. J.; Schubert, E.; Rai, A. K.; Wieck, A. D.; Reuter, D.; Wurstbauer, U.; Holleitner, A. W.; 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.

  14. Note: Development of high speed confocal 3D profilometer

    NASA Astrophysics Data System (ADS)

    Ang, Kar Tien; Fang, Zhong Ping; Tay, Arthur

    2014-11-01

    A high-speed confocal 3D profilometer based on the chromatic confocal technology and spinning Nipkow disk technique has been developed and tested. It can measure a whole surface topography by taking only one image that requires less than 0.3 s. Surface height information is retrieved based on the ratios of red, green, and blue color information. A new vector projection technique has developed to enhance the vertical resolution of the measurement. The measurement accuracy of the prototype system has been verified via different test samples.

  15. Spectral imaging technique for retinal perfusion detection using confocal scanning laser ophthalmoscopy.

    PubMed

    Rasta, Seyed Hossein; Manivannan, Ayyakkannu; Sharp, Peter F

    2012-11-01

    To evaluate retinal perfusion in the human eye, a dual-wavelength confocal scanning laser ophthalmoscope (cSLO) was developed that provides spectral imaging of the fundus using a combination of red (670 nm) and near-infrared (810 nm) wavelengths. The image of the ocular fundus was analyzed to find out if quantitative measurements of the reflectivity of tissue permit assessment of the oxygen perfusion of tissue. We explored problems that affect the reproducibility of patient measurements such as non-uniformity errors on the image. For the first time, an image processing technique was designed and used to minimize the errors of oxygen saturation measurements by illumination correction in retina wide field by increasing SNR. Retinal images were taken from healthy and diabetic retinopathy eyes using the cSLO with a confocal aperture of 100 ?m. The ratio image (RI) of red/IR, as oxygen saturation (SO2) index, was calculated for normal eyes. The image correction technique improved the reproducibility of the measurements. Average RI intensity variation of healthy retina tissue was determined within a range of about 5.5%. The capability of the new technique to discriminate oxygenation levels of retinal artery and vein was successfully demonstrated and showed good promise in the diagnosis of the perfused retina. PMID:23117800

  16. Spectral imaging technique for retinal perfusion detection using confocal scanning laser ophthalmoscopy

    NASA Astrophysics Data System (ADS)

    Rasta, Seyed Hossein; Manivannan, Ayyakkannu; Sharp, Peter F.

    2012-11-01

    To evaluate retinal perfusion in the human eye, a dual-wavelength confocal scanning laser ophthalmoscope (cSLO) was developed that provides spectral imaging of the fundus using a combination of red (670 nm) and near-infrared (810 nm) wavelengths. The image of the ocular fundus was analyzed to find out if quantitative measurements of the reflectivity of tissue permit assessment of the oxygen perfusion of tissue. We explored problems that affect the reproducibility of patient measurements such as non-uniformity errors on the image. For the first time, an image processing technique was designed and used to minimize the errors of oxygen saturation measurements by illumination correction in retina wide field by increasing SNR. Retinal images were taken from healthy and diabetic retinopathy eyes using the cSLO with a confocal aperture of 100 ?m. The ratio image (RI) of red/IR, as oxygen saturation (SO2) index, was calculated for normal eyes. The image correction technique improved the reproducibility of the measurements. Average RI intensity variation of healthy retina tissue was determined within a range of about 5.5%. The capability of the new technique to discriminate oxygenation levels of retinal artery and vein was successfully demonstrated and showed good promise in the diagnosis of the perfused retina.

  17. In vivo fluorescence confocal microscopy: indocyanine green enhances the contrast of epidermal and dermal structures

    NASA Astrophysics Data System (ADS)

    Skvara, Hans; Kittler, Harald; Schmid, Johannes A.; Plut, Ulrike; Jonak, Constanze

    2011-09-01

    In recent years, in vivo skin imaging devices have been successfully implemented in skin research as well as in clinical routine. Of particular importance is the use of reflectance confocal microscopy (RCM) and fluorescence confocal microscopy (FCM) that enable visualization of the tissue with a resolution comparable to histology. A newly developed commercially available multi-laser device in which both technologies are integrated now offers the possibility to directly compare RCM with FCM. The fluorophore indocyanine green (ICG) was intradermally injected into healthy forearm skin of 10 volunteers followed by in vivo imaging at various time points. In the epidermis, accurate assessment of cell morphology with FCM was supplemented by identification of pigmented cells and structures with RCM. In dermal layers, only with FCM connective tissue fibers were clearly contoured down to a depth of more than 100 ?m. The fluorescent signal still provided a favorable image contrast 24 and 48 hours after injection. Subsequently, ICG was applied to different types of skin diseases (basal cell carcinoma, actinic keratosis, seborrhoeic keratosis, and psoriasis) in order to demonstrate the diagnostic benefit of FCM when directly compared with RCM. Our data suggest a great impact of FCM in combination with ICG on clinical and experimental dermatology in the future.

  18. Fault localization and analysis in semiconductor devices with optical-feedback infrared confocal microscopy

    SciTech Connect

    Sarmiento, Raymund; Cemine, Vernon Julius; Tagaca, Imee Rose; Salvador, Arnel; Mar Blanca, Carlo; Saloma, Caesar

    2007-11-01

    We report on a cost-effective optical setup for characterizing light-emitting semiconductor devices with optical-feedback confocal infrared microscopy and optical beam-induced resistance change.We utilize the focused beam from an infrared laser diode to induce local thermal resistance changes across the surface of a biased integrated circuit (IC) sample. Variations in the multiple current paths are mapped by scanning the IC across the focused beam. The high-contrast current maps allow accurate differentiation of the functional and defective sites, or the isolation of the surface-emittingp-i-n devices in the IC. Optical beam-induced current (OBIC) is not generated since the incident beam energy is lower than the bandgap energy of the p-i-n device. Inhomogeneous current distributions in the IC become apparent without the strong OBIC background. They are located at a diffraction-limited resolution by referencing the current maps against the confocal reflectance image that is simultaneously acquired via optical-feedback detection. Our technique permits the accurate identification of metal and semiconductor sites as well as the classification of different metallic structures according to thickness, composition, or spatial inhomogeneity.

  19. Plasmon resonance and the imaging of metal-impregnated neurons with the laser scanning confocal microscope.

    PubMed

    Thompson, Karen J; Harley, Cynthia M; Barthel, Grant M; Sanders, Mark A; Mesce, Karen A

    2015-01-01

    The staining of neurons with silver began in the 1800s, but until now the great resolving power of the laser scanning confocal microscope has not been utilized to capture the in-focus and three-dimensional cytoarchitecture of metal-impregnated cells. Here, we demonstrate how spectral confocal microscopy, typically reserved for fluorescent imaging, can be used to visualize metal-labeled tissues. This imaging does not involve the reflectance of metal particles, but rather the excitation of silver (or gold) nanoparticles and their putative surface plasmon resonance. To induce such resonance, silver or gold particles were excited with visible-wavelength laser lines (561 or 640 nm), and the maximal emission signal was collected at a shorter wavelength (i.e., higher energy state). Because the surface plasmon resonances of noble metal nanoparticles offer a superior optical signal and do not photobleach, our novel protocol holds enormous promise of a rebirth and further development of silver- and gold-based cell labeling protocols. PMID:26670545

  20. Confocal Laser Microscope Scanning Applied To Three-Dimensional Studies Of Biological Specimens.

    NASA Astrophysics Data System (ADS)

    Franksson, Olof; Liljeborg, Anders; Carlsson, Kjell; Forsgren, Per-Ola

    1987-08-01

    The depth-discriminating property of confocal laser microscope scanners can be used to record the three-dimensional structure of specimens. A number of thin sections (approx. 1 ?m thick) can be recorded by a repeated process of image scanning and refocusing of the microscope. We have used a confocal microscope scanner in a number of feasibility studies to investigate its possibilities and limitations. It has proved to be well suited for examining fluorescent specimens with a complicated three-dimensional structure, such as nerve cells. It has also been used to study orchid seeds, as well as cell colonies, greatly facilitating evaluation of such specimens. Scanning of the specimens is performed by a focused laser beam that is deflected by rotating mirrors, and the reflected or fluorescent light from the specimen is detected. The specimen thus remains stationary during image scanning, and is only moved stepwise in the vertical direction for refocusing between successive sections. The scanned images consist of 256*256 or 512*512 pixels, each pixel containing 8 bits of data. After a scanning session a large number of digital images, representing consecutive sections of the specimen, are stored on a disk memory. In a typical case 200 such 256*256 images are stored. To display and process this information in a meaningful way requires both appropriate software and a powerful computer. The computer used is a 32-bits minicomputer equipped with an array processor (FPS 100). The necessary software was developed at our department.

  1. A UV laser-scanning confocal microscope for the measurement of intracellular Ca2+.

    PubMed

    Kuba, K; Hua, S Y; Hayashi, T

    1994-09-01

    Modifications to the optics of a conventional confocal laser-scanning microscope were made to allow imaging intracellular Ca(2+)-dependent fluorescence with a UV laser (351 or 364 nm). Modifications included: (1) a chromatic compensation lens in the laser path; (2) the design of a practically achromatic relay lens; (3) a longer tube length for the objective; and (4) highly reflective mirrors maximizing fluorescence measurement. This UV laser-scanning confocal microscope (UV-CLSM) yielded a lateral resolution of < 0.3 micron and an axial resolution of < 1.5 microns and a relevant field size of 100 microns in diameter for a 40X objective). The effects of varying the focal length of a compensation lens, the degree of the correction for the coverglass thickness of objective and the detector aperture size on the quality of image formation were examined. Finally, UV-CLSM revealed optical sections of fine and complex structures of bullfrog sympathetic neurones loaded with a Ca(2+)-sensitive fluorescent probe. Changes in intracellular free Ca2+ distribution in response to high [K+] or caffeine were demonstrated. In addition, an increase in the intracellular concentration of caffeine applied externally was clearly imaged in space and time and distinguished from a resultant rise in [Ca2+]i. Thus, the UV-CLSM developed is suitable for ratiometric intracellular Ca2+ measurements and other biological studies. PMID:7828174

  2. In-vivo diagnosis and non-inasive monitoring of Imiquimod 5% cream for non-melanoma skin cancer using confocal laser scanning microscopy

    NASA Astrophysics Data System (ADS)

    Dietterle, S.; Lademann, J.; Röwert-Huber, H.-J.; Stockfleth, E.; Antoniou, C.; Sterry, W.; Astner, S.

    2008-10-01

    Basal cell carcinoma (BCC) is the most common cutaneous malignancy with increasing incidence rates worldwide. A number of established treatments are available, including surgical excision. The emergence of new non-invasive treatment modalities has prompted the development of non-invasive optical devices for therapeutic monitoring and evaluating treatment efficacy. This study was aimed to evaluate the clinical applicability of a fluorescence confocal laser scanning microscope (CFLSM) for non-invasive therapeutic monitoring of basal cell carcinoma treated with Imiquimod (Aldara®) as topical immune-response modifier. Eight participants with a diagnosis of basal cell carcinoma (BCC) were enrolled in this investigation. Sequential evaluation during treatment with Imiquimod showed progressive normalization of the confocal histomorphologic parameters in correlation with normal skin. Confocal laser scanning microscopy was able to identify characteristic features of BCC and allowed the visualization of therapeutic effects over time. Thus our results indicate the clinical applicability of CFLSM imaging to evaluate treatment efficacy in vivo and non-invasively.

  3. Design and optimization of tracking in a confocal microscope

    NASA Astrophysics Data System (ADS)

    Shen, Zhaolong

    The ability to image and analyze fluorescent molecules both in vitro and in vivo is of great interest in molecular biology. Tracking systems to enable such imaging continue to be developed based on a variety of approaches. Existing tracking techniques generally require complicated and expensive experimental setups or are limited in their capability. This dissertation describes a system for tracking multiple fluorescent particles in a standard confocal microscope with a piezoactuated nanopositioning stage. A position estimation algorithm, fluoroBancroft, is utilized to analytically estimate particle position from a collection of measurements taken at discrete locations around the particle. This estimate is then used in a linear quadratic Gaussian (LQG) controller to regulate the tracking error. The technique relies on a standard confocal setup, making it easier to implement than other tracking schemes. The experimental results indicated that the system can track single and multiple particles successfully in both two and three dimensions. To verify tracking and characterize tracking performance in these experiments, a CCD camera was introduced into the physical setup and synchronized to capture an image at every measurement location. In two dimensions, the overall tracking error was approximated by the standard deviation of the position estimates derived from each of the images. We find the tracking error increases as the square root of the diffusion coefficient plus an additional error that comes from position estimation error, digital-to-analog or analog-to-digital error and controller parameters mismatch. While the CCD-based estimates of the 3-D position of the particle were not accurate enough to quantify tracking performance, they did provide independent confirmation of tracking. Because the performance of the estimation depends strongly on the choice of measurement pattern, we also describe work on optimizing that pattern to minimize the variance of the estimate subject to an unbiasedness constraint The analysis takes ad- vantage of the fact that the natural logarithm of a Poisson random variable with large rate can be approximated as a random variable with a Gaussian distribution. A sufficient condition for an unbiased measurement constellation and the optimal radius of a given constellation geometry with six measurements are then derived. The results are illustrated through both numerical simulation and experiments. In addition to optimizing the measurement pattern, this dissertation also describes new results on the time-optimal control of second-order systems and an application of that theory to increase the throughput of the tracking system. Two linear affine mappings are derived to transfer the system to the normal coordinates. Based on the switching curve for a holdable equilibrium target state constructed in the normal coordinates, the switching number and switching time of the bang-bang control are numerically calculated, and a feedback time-optimal control law is designed too. The switching curves for both non-equilibrium and non-holdable equilibrium target state are also discussed.

  4. Application of CO2 Snow Jet Cleaning in Conjunction with Laboratory Based Total Reflection X-Ray Fluorescence

    NASA Technical Reports Server (NTRS)

    Schmeling, M.; Burnett, D. S.; Allton, J. H.; Rodriquez, M.; Tripa, C. E.; Veryovkin, I. V.

    2013-01-01

    The Genesis mission was the first mission returning solar material to Earth since the Apollo program [1,2]. Unfortunately the return of the space craft on September 8, 2004 resulted in a crash landing, which shattered the samples into small fragments and exposed them to desert soil and other debris. Thus only small fragments of the original collectors are available, each having different degrees of surface contamination. Thorough surface cleaning is required to allow for subsequent analysis of solar wind material embedded within. An initial cleaning procedure was developed in coordination with Johnson Space Center which focused on removing larger sized particulates and a thin film organic contamination acquired during collection in space [3]. However, many of the samples have additional residues and more rigorous and/or innovative cleaning steps might be necessary. These cleaning steps must affect only the surface to avoid leaching and re-distribution of solar wind material from the bulk of the collectors. To aid in development and identification of the most appropriate cleaning procedures each sample has to be thoroughly inspected before and after each cleaning step. Laboratory based total reflection X-ray fluorescence (TXRF) spectrometry lends itself to this task as it is a non-destructive and surface sensitive analytical method permitting analysis of elements from aluminum onward present at and near the surface of a flat substrate [4]. The suitability of TXRF has been demonstrated for several Genesis solar wind samples before and after various cleaning methods including acid treatment, gas cluster ion beam, and CO2 snow jet [5 - 7]. The latter one is non-invasive and did show some promise on one sample [5]. To investigate the feasibility of CO2 snow jet cleaning further, several flown Genesis samples were selected to be characterized before and after CO2 snow application with sample 61052 being discussed below.

  5. In vivo confocal microscopy of the human cornea

    PubMed Central

    Jalbert, I; Stapleton, F; Papas, E; Sweeney, D F; Coroneo, M

    2003-01-01

    Aims: To describe the optics of in vivo confocal microscopy, its advantages over previous methods, and to summarise the literature that arose from its use for the observation of the human cornea. A critical review of the clinical usefulness of this new technology for the corneal examination is undertaken. Methods: Confocal microscopes obtain increased resolution by limiting the illumination and observation systems to a single point. Rapid scanning is used to reconstruct a full field of view and allows for “real time” viewing. Results: Coronal sections of the in situ epithelium, Bowman’s membrane, stroma, and endothelium can be visualised at a resolution of 1–2 ?m. A backscattered light intensity curve allows objective measurements of sublayer thickness and corneal haze to be taken. In vivo confocal microscopy is therefore particularly useful in the areas of infective keratitis, corneal dystrophies, refractive surgery, and contact lens wear, where it aids in differential diagnosis and detection of subtle short and long term changes. Real time endothelial cell assessment can also be performed. Conclusion: Because of their ability to visualise living tissue at cellular levels, confocal microscopes have proved useful additions to the current clinical tools. PMID:12543757

  6. CONFOCAL MICROSCOPY SYSTEM PERFORMANCE: FOUNDATIONS FOR CALIBRATION, QUANTITATION AND SPECTROSCOPY

    EPA Science Inventory

    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...

  7. CONFOCAL MICROSCOPY SYSTEM PERFORMANCE: QA TESTS, QUANTITATION AND SPECTROSCOPY

    EPA Science Inventory

    Confocal Microscopy System Performance: QA tests, Quantitation and Spectroscopy.

    Robert M. Zucker 1 and Jeremy M. Lerner 2,
    1Reproductive Toxicology Division, National Health and Environmental Effects Research Laboratory, Office of Research Development, U.S. Environmen...

  8. CONFOCAL MICROSCOPY SYSTEM PERFORMANCE: FOUNDATIONS FOR MEASUREMENTS, QUANTITATION AND SPECTROSCOPY

    EPA Science Inventory

    The confocal laser-scanning microscopy (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 the emitted signal. The accuracy of these measurements demands t...

  9. page 1 of 6Confocal Raman Microscopy ...SEEtheFuture

    E-print Network

    Lombardi, John R.

    Marvin Minsky. He was obsessed with resolving the mystery of the human nerve system anatomy which aids confocal microscope [1]. Optical design principles Prof. Minsky hypothesized that all the scattered light series of optical sections from bulk specimens. With this optical design, Prof. Minsky was able

  10. Confocal Imaging of Microglial Cell Dynamics in Hippocampal Slice Cultures

    E-print Network

    Dailey, Michael E.

    Confocal Imaging of Microglial Cell Dynamics in Hippocampal Slice Cultures Michael E. Dailey1 are described for imaging the cellular dynamics of microglia in live mammalian brain slice cultures. Brain or static filter culture technique, stained with one or more fluorescent dyes, and imaged by scanning laser

  11. CONFOCAL MICROSCOPY SYSTEM PERFORMANCE: SPECTROSCOPY AND FOUNDATIONS FOR QUANTITATION

    EPA Science Inventory

    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...

  12. Laser excited confocal microscope fluorescence scanner and method

    DOEpatents

    Mathies, R.A.; Peck, K.

    1992-02-25

    A fluorescent scanner is designed for scanning the fluorescence from a fluorescence labeled separated sample on a sample carrier. The scanner includes a confocal microscope for illuminating a predetermined volume of the sample carrier and/or receiving and processing fluorescence emissions from the volume to provide a display of the separated sample. 8 figs.

  13. Laser excited confocal microscope fluorescence scanner and method

    DOEpatents

    Mathies, Richard A. (Contra Costa, CA); Peck, Konan (Contra Costa, CA)

    1992-01-01

    A fluorescent scanner for scanning the fluorescence from a fluorescence labeled separated sample on a sample carrier including a confocal microscope for illuminating a predetermined volume of the sample carrier and/or receiving and processing fluorescence emissions from said volume to provide a display of the separated sample.

  14. Smart microscope: an adaptive optics learning system for aberration correction in multiphoton confocal microscopy.

    PubMed

    Albert, O; Sherman, L; Mourou, G; Norris, T B; Vdovin, G

    2000-01-01

    Off-axis aberrations in a beam-scanning multiphoton confocal microscope are corrected with a deformable mirror. The optimal mirror shape for each pixel is determined by a genetic learning algorithm, in which the second-harmonic or two-photon fluorescence signal from a reference sample is maximized. The speed of the convergence is improved by use of a Zernike polynomial basis for the deformable mirror shape. This adaptive optical correction scheme is implemented in an all-reflective system by use of extremely short (10-fs) optical pulses, and it is shown that the scanning area of an f:1 off-axis parabola can be increased by nine times with this technique. PMID:18059779

  15. Solar Confocal interferometers for Sub-Picometer-Resolution Spectral Filters

    NASA Technical Reports Server (NTRS)

    Gary, G. Allen; Pietraszewski, Chris; West, Edward A.; Dines. Terence C.

    2007-01-01

    The confocal Fabry-Perot interferometer allows sub-picometer spectral resolution of Fraunhofer line profiles. Such high spectral resolution is needed to keep pace with the higher spatial resolution of the new set of large-aperture solar telescopes. The line-of-sight spatial resolution derived for line profile inversions would then track the improvements of the transverse spatial scale provided by the larger apertures. In particular, profile inversion allows improved velocity and magnetic field gradients to be determined independent of multiple line analysis using different energy levels and ions. The confocal interferometer's unique properties allow a simultaneous increase in both etendue and spectral power. The higher throughput for the interferometer provides significant decrease in the aperture, which is important in spaceflight considerations. We have constructed and tested two confocal interferometers. A slow-response thermal-controlled interferometer provides a stable system for laboratory investigation, while a piezoelectric interferometer provides a rapid response for solar observations. In this paper we provide design parameters, show construction details, and report on the laboratory test for these interferometers. The field of view versus aperture for confocal interferometers is compared with other types of spectral imaging filters. We propose a multiple etalon system for observing with these units using existing planar interferometers as pre-filters. The radiometry for these tests established that high spectral resolution profiles can be obtained with imaging confocal interferometers. These sub-picometer spectral data of the photosphere in both the visible and near-infrared can provide important height variation information. However, at the diffraction-limited spatial resolution of the telescope, the spectral data is photon starved due to the decreased spectral passband.

  16. Characterization of reflectance variability in the industrial paint application of automotive metallic coatings by using principal component analysis

    NASA Astrophysics Data System (ADS)

    Medina, José M.; Díaz, José A.

    2013-05-01

    We have applied principal component analysis to examine trial-to-trial variability of reflectances of automotive coatings that contain effect pigments. Reflectance databases were measured from different color batch productions using a multi-angle spectrophotometer. A method to classify the principal components was used based on the eigenvalue spectra. It was found that the eigenvalue spectra follow distinct power laws and depend on the detection angle. The scaling exponent provided an estimation of the correlation between reflectances and it was higher near specular reflection, suggesting a contribution from the deposition of effect pigments. Our findings indicate that principal component analysis can be a useful tool to classify different sources of spectral variability in color engineering.

  17. Photometric phase functions of common geologic minerals and applications to quantitative analysis of mineral mixture reflectance spectra

    NASA Technical Reports Server (NTRS)

    Mustard, John F.; Pieters, Carle M.

    1989-01-01

    The mass fractional abundance of components in intimately mixed, particulate surfaces is calculated from laboratory reflectance spectra using Hapke's (1981) model for bidirectional reflectance. It is found that a simplified version of the model is accurate to within 7 percent for mixtures not containing low albedo components. The model is not appropriate for mixtures with very low and high albedo components. Consideration is given to the possible improvement of the method's accuracy by using an empirical single-particle phase function to describe the scattering characteristics of all minerals, or by solving for the single-particle phase function of the minerals involved exactly using extensive bidirectional reflectance measurements and Hapke's equations for bidirectional reflectance. Also, the results are used to examine the general scattering behavior of particulate mineral surfaces.

  18. Optical sectioning using a digital Fresnel incoherent-holography-based confocal imaging system

    PubMed Central

    Kelner, Roy; Katz, Barak; Rosen, Joseph

    2015-01-01

    We propose a new type of confocal microscope using Fresnel incoherent correlation holography (FINCH). Presented here is a confocal configuration of FINCH using a phase pinhole and point illumination that is able to suppress out-of-focus information from the recorded hologram and hence combine the super-resolution capabilities of FINCH with the sectioning capabilities of confocal microscopy. PMID:26413560

  19. Comparative three-dimensional imaging of living neurons with confocal and atomic force microscopy.

    PubMed

    McNally, Helen A; Rajwa, Bartek; Sturgis, Jennie; Robinson, J Paul

    2005-03-30

    Atomic force microscopy applications extend across a number of fields; however, limitations have reduced its effectiveness in live cell analysis. This report discusses the use of AFM to evaluate the three-dimensional (3-D) architecture of living chick dorsal root ganglia and sympathetic ganglia. These data sets were compared to similar images acquired with confocal laser scanning microscopy of identical cells. For this comparison we made use of visualization techniques which were applicable to both sets of data and identified several issues when coupling these technologies. These direct comparisons offer quantitative validation and confirmation of the character of novel images acquired by AFM. This paper is one in a series emphasizing various new applications of AFM in neurobiology. PMID:15698657

  20. Spatial filtering of a diode laser beam for confocal Raman microscopy.

    PubMed

    Kitt, Jay P; Bryce, David A; Harris, Joel M

    2015-04-01

    With the development of single-longitudinal mode diode lasers, there has been an increase in using these sources for Raman spectroscopy. This is largely due to the cost-effectiveness of diode lasers, which offer savings not only in initial capital cost, but also electrical, cooling, and replacement costs over time, when compared with ion lasers. The use of diode-lasers in confocal Raman microscopy has remained a challenge, however, due to poor transverse beam quality. In this work, we present the design and implementation of a simple spatial filter capable of adapting a single-mode diode laser source to confocal Raman microscopy, yielding comparable spatial resolution as a gas-ion laser beam for profiling and optical-trapping applications. For profiling applications, spatial filtering improved x,y resolution of the beam by a factor 10, which in turn increased optical-trapping forces by ~90 times and yielded sevenfold greater Raman scattering signal intensity from an optically trapped phospholipid vesicle. PMID:25741877

  1. Miniature near-infrared dual-axes confocal microscope utilizing a two-dimensional microelectromechanical systems scanner

    PubMed Central

    Liu, Jonathan T. C.; Mandella, Michael J.; Ra, Hyejun; Wong, Larry K.; Solgaard, Olav; Kino, Gordon S.; Piyawattanametha, Wibool; Contag, Christopher H.; Wang, Thomas D.

    2007-01-01

    The first, to our knowledge, miniature dual-axes confocal microscope has been developed, with an outer diameter of 10 mm, for subsurface imaging of biological tissues with 5–7 ?m resolution. Depth-resolved en face images are obtained at 30 frames per second, with a field of view of 800 × 100 ?m, by employing a two-dimensional scanning microelectromechanical systems mirror. Reflectance and fluorescence images are obtained with a laser source at 785 nm, demonstrating the ability to perform real-time optical biopsy. PMID:17215937

  2. Miniature near-infrared dual-axes confocal microscope utilizing a two-dimensional microelectromechanical systems scanner.

    PubMed

    Liu, Jonathan T C; Mandella, Michael J; Ra, Hyejun; Wong, Larry K; Solgaard, Olav; Kino, Gordon S; Piyawattanametha, Wibool; Contag, Christopher H; Wang, Thomas D

    2007-02-01

    The first, to our knowledge, miniature dual-axes confocal microscope has been developed, with an outer diameter of 10 mm, for subsurface imaging of biological tissues with 5-7 microm resolution. Depth-resolved en face images are obtained at 30 frames per second, with a field of view of 800 x 100 microm, by employing a two-dimensional scanning microelectromechanical systems mirror. Reflectance and fluorescence images are obtained with a laser source at 785 nm, demonstrating the ability to perform real-time optical biopsy. PMID:17215937

  3. Confocal Raman microscopy for investigation of the level of differentiation in living neuroblastoma tumor cells

    NASA Astrophysics Data System (ADS)

    Scalfi-Happ, Claudia; Jauss, Andrea; Hollricher, Olaf; Fulda, Simone; Hauser, Carmen; Steiner, Rudolf; Rück, Angelika

    2007-07-01

    The investigation of living cells at physiological conditions requires very sensitive, sophisticated, non invasive methods. In this study, Raman spectral imaging is used to identify different biomolecules inside of cells. Raman spectroscopy, a chemically and structurally sensitive measuring technique, is combined with high resolution confocal microscopy. In Raman spectral imaging mode, a complete Raman spectrum is recorded at every confocal image point, giving insight into the chemical composition of each sample compartment. Neuroblastoma is the most common solid extra-cranial tumor in children. One of the unique features of neuroblastoma cells is their ability to differentiate spontaneously, eventually leading to complete remission. Since differentiation agents are currently used in the clinic for neuroblastoma therapy, there is a special need to develop non-invasive and sensitive new methods to monitor neuroblastoma cell differentiation. Neuroblastoma cells at different degrees of differentiation were analysed with the confocal Raman microscope alpha300 R (WITec GmbH, Germany), using a frequency doubled Nd:YAG laser at 532 nm and 10 mW for excitation. Integration time per spectrum was 80-100 ms. A lateral resolution in submicrometer range was achieved by using a 60x water immersion lens with a numerical aperture of 1,0. Raman images of cells were generated from these sets of data by either integrating over specific Raman bands, by basis analysis using reference spectra or by cluster analysis. The automated evaluation of all spectra results in spectral unmixed images providing insight into the chemical composition of the sample. With these procedures, different cell organelles, cytosol, membranes could be distinguished. Since neuroblastoma cells at high degree of differentiation overproduce noradrenaline, an attempt was made to trace the presence of this neurotransmitter as a marker for differentiation. The results of this work may have applications in the monitoring of molecular changes and distribution of biomolecules and in particular of low molecular weight markers as they occur during the differentiation of neuroblastoma cells.

  4. Large-aperture ultra-long focal length measurement and its system by laser confocal techniques

    NASA Astrophysics Data System (ADS)

    Li, Zhigang; Qiu, Lirong; Zhao, Weiqian; Guo, Yongkui; Yuan, Quan

    2015-09-01

    A new laser confocal ultralong focal length measurement method (LCFM) is proposed with the capability to self-calibrate the reference lens (RL) focal length and the axial space between the test lens and the RL. Using the property that the focus of a laser confocal ultralong focal length measurement system (LCFS) precisely corresponds to the peak point of the confocal axial intensity curve, the proposed LCFM measures the RL focal length f\\text{R}\\prime by precisely identifying the positions of the focus and the last surface of the RL, measures the axial space d0 between the RL and the test ultra-long focal-length lens (UFL) by identifying the last surface of the RL and the vertex of the UFL last surface, measures the variation l in focus position of the LCFS with and without the test UFL, and then calculates the UFL focal length f\\text{T}\\prime using the above-measured f\\text{R}\\prime , d0, and l. Furthermore, the LCFM uses conic fitting, which obviously enhances the measurement accuracy by reducing the influences of random disturbances. In addition, an LCFS based on the proposed method is developed for large aperture lens. The experimental results indicate that the relative uncertainty is less than 0.015% for the test UFL, which has an aperture of 610?mm and a focal length of 31?000?mm. Compared with existing methods, the LCFM utilizes a concise structure and has good stability, making it especially suitable for practical engineering applications.

  5. Evaluation of optical reflectance techniques for imaging of alveolar structure

    NASA Astrophysics Data System (ADS)

    Unglert, Carolin I.; Namati, Eman; Warger, William C.; Liu, Linbo; Yoo, Hongki; Kang, DongKyun; Bouma, Brett E.; Tearney, Guillermo J.

    2012-07-01

    Three-dimensional (3-D) visualization of the fine structures within the lung parenchyma could advance our understanding of alveolar physiology and pathophysiology. Current knowledge has been primarily based on histology, but it is a destructive two-dimensional (2-D) technique that is limited by tissue processing artifacts. Micro-CT provides high-resolution three-dimensional (3-D) imaging within a limited sample size, but is not applicable to intact lungs from larger animals or humans. Optical reflectance techniques offer the promise to visualize alveolar regions of the large animal or human lung with sub-cellular resolution in three dimensions. Here, we present the capabilities of three optical reflectance techniques, namely optical frequency domain imaging, spectrally encoded confocal microscopy, and full field optical coherence microscopy, to visualize both gross architecture as well as cellular detail in fixed, phosphate buffered saline-immersed rat lung tissue. Images from all techniques were correlated to each other and then to corresponding histology. Spatial and temporal resolution, imaging depth, and suitability for in vivo probe development were compared to highlight the merits and limitations of each technology for studying respiratory physiology at the alveolar level.

  6. Numerical calculation of the reflectance of sub-wavelength structures on silicon nitride for solar cell application

    NASA Astrophysics Data System (ADS)

    Sahoo, Kartika Chandra; Li, Yiming; Chang, Edward Yi

    2009-10-01

    In this study, we calculate the spectral reflectivity of pyramid-shaped silicon nitride (Si 3N 4) sub-wavelength structures (SWS). A multilayer rigorous coupled-wave approach is advanced to investigate the reflection properties of Si 3N 4 SWS. We examine the simulation results for single layer antireflection (SLAR) and double layer antireflection (DLAR) coatings with SWS on Si 3N 4 surface, taking into account effective reflectivity over a range of wavelengths and solar efficiency. The results of our study show that a lowest effective reflectivity of 1.77% can be obtained for the examined Si 3N 4 SWS with the height of etched part of Si 3N 4 and the thickness of non-etched layer of 150 and 70 nm, respectively, which is less than the results of an optimized 80 nm Si 3N 4 SLAR (˜5.41%) and of an optimized DLAR with 80 nm Si 3N 4 and 100 nm magnesium fluoride (˜5.39%). 1% cell efficiency increase is observed for the optimized Si solar cell with Si 3N 4 SWS, compared with the cell with single layer Si 3N 4 antireflection coatings (ARCs); furthermore, compared with DLAR coated solar cell, the increase is about 0.71%. The improvement on the cell efficiency is mainly due to lower reflectance of Si 3N 4 SWS over a wavelength region from 400 to 600 nm that leads to lower short circuit current.

  7. Three-Dimensional Visualization of Interfacial Phenomena Using Confocal Microscopy

    NASA Astrophysics Data System (ADS)

    Shieh, Ian C.

    Surfactants play an integral role in numerous functions ranging from stabilizing the emulsion in a favorite salad dressing to organizing the cellular components that make life possible. We are interested in lung surfactant, which is a mixture of lipids and proteins essential for normal respiration because it modulates the surface tension of the air-liquid interface of the thin fluid lining in the lungs. Through this surface tension modulation, lung surfactant ensures effortless lung expansion and prevents lung collapse during exhalation, thereby effecting proper oxygenation of the bloodstream. The function of lung surfactant, as well as numerous interfacial lipid systems, is not solely dictated by the behavior of materials confined to the two-dimensional interface. Rather, the distributions of materials in the liquid subphase also greatly influence the performance of interfacial films of lung surfactant. Therefore, to better understand the behavior of lung surfactant and other interfacial lipid systems, we require a three-dimensional characterization technique. In this dissertation, we have developed a novel confocal microscopy methodology for investigating the interfacial phenomena of surfactants at the air-liquid interface of a Langmuir trough. Confocal microscopy provides the excellent combination of in situ, fast, three-dimensional visualization of multiple components of the lung surfactant system that other characterization techniques lack. We detail the solutions to the numerous challenges encountered when imaging a dynamic air-liquid interface with a high-resolution technique like confocal microscopy. We then use confocal microscopy to elucidate the distinct mechanisms by which a polyelectrolyte (chitosan) and nonadsorbing polymer (polyethylene glycol) restore the function of lung surfactant under inhibitory conditions mimicking the effects of lung trauma. Beyond this physiological model, we also investigate several one- and two-component interfacial films of the various lipid constituents of lung surfactant. Confocal microscopy allows us to use a water-soluble, cationic fluorophore that partitions into the disordered phases of lipid monolayers. By exploiting the properties of this water-soluble fluorophore, we investigate both the phase behavior and electrostatics of the interfacial lipid systems. Overall, we believe the work presented in this dissertation provides the building blocks for establishing confocal microscopy as a ubiquitous characterization technique in the interfacial and surface sciences.

  8. Effects of acids used in the microabrasion technique: Microhardness and confocal microscopy analysis

    PubMed Central

    Pini, Núbia-Inocencya-Pavesi; Ambrosano, Gláucia-Maria-Bovi; da Silva, Wander-José; Aguiar, Flávio-Henrique-Baggio; Lovadino, José-Roberto

    2015-01-01

    Background This study evaluated the effects of the acids used in the microabrasion on enamel. Material and Methods Seventy enamel/dentine blocks (25 mm2) of bovine incisors were divided into 7 groups (n=10). Experimental groups were treated by active/passive application of 35% H3PO4 (E1/E2) or 6.6% HCl (E3/E4). Control groups were treated by microabrasion with H3PO4+pumice (C5), HCl+silica (C6), or no treatment (C7). The superficial (SMH) and cross-sectional (CSMH; depths of 10, 25, 50, and 75 µm) microhardness of enamel were analyzed. Morphology was evaluated by confocal laser-scanning microscopy (CLSM). Data were analyzed by analysis of variance (Proc Mixed), Tukey, and Dunnet tests (?=5%). Results Active application (E1 and E3) resulted in higher microhardness than passive application (E2 and E4), with no difference between acids. For most groups, the CSMH decreased as the depth increased. All experimental groups and negative controls (C5 and C6) showed significantly reduced CSMH values compared to the control. A significantly higher mean CSMH result was obtained with the active application of H3PO4 (E1) compared to HCl (E3). Passive application did not result in CSMH differences between acids. CLSM revealed the conditioning pattern for each group. Conclusions Although the acids displayed an erosive action, use of microabrasive mixture led to less damage to the enamel layers. Key words:Enamel microabrasion, enamel microhardness, confocal laser scanning microscopy. PMID:26535098

  9. Confocal Light Absorption and Scattering Spectroscopic (CLASS) imaging: From cancer detection to sub-cellular function

    NASA Astrophysics Data System (ADS)

    Qiu, Le

    Light scattering spectroscopy (LSS), an optical technique that relates the spectroscopic properties of light elastically scattered by small particles to their size, refractive index and shape, has been recently successfully employed for sensing morphological and biochemical properties of epithelial tissues and cells in vivo. LSS does not require exogenous markers, is non-invasive, and, due to its multispectral nature, can sense biological structures well beyond the diffraction limit. All that makes LSS be a very good candidate to be used both in clinical medicine for in vivo detection of disease and in cell biology to monitor cell function on the organelle scale. Recently we developed two LSS-based imaging modalities: clinical Polarized LSS (PLSS) Endoscopic Technique for locating early pre-cancerous changes in GI tract and Confocal Light Absorption and Scattering Spectroscopic (CLASS) Microscopy for studying cells in vivo without exogenous markers. One important application of the clinical PLSS endoscopic instrument, a noncontact scanning imaging device compatible with the standard clinical endoscopes and capable of detecting dysplastic changes, is to serve as a guide for biopsy in Barrett's esophagus (BE). The instrument detects parallel and perpendicular components of the polarized light, backscattered from epithelial tissues, and determines characteristics of epithelial nuclei from the residual spectra. It also can find tissue oxygenation, hemoglobin content and other properties from the diffuse light component. By rapidly scanning esophagus the PLSS endoscopic instrument makes sure the entire BE portion is scanned and examined for the presence of dysplasia. CLASS microscopy, on the other hand, combines principles of light scattering spectroscopy (LSS) with confocal microscopy. Its main purpose is to image cells on organelle scale in vivo without the use of exogenous labels which may affect the cell function. The confocal geometry selects specific region and images are obtained by scanning the confocal volume across the sample. The new beam scanning CLASS microscope is a significant improvement over the previous proof-of-principle device. With this new device we have already performed experiments to monitor morphological changes in cells during apoptosis, differentiated fetal from maternal nucleated red blood cells, and detected plasmon scattering spectra of single gold nanorod.

  10. A deep view in cultural heritage—confocal micro X-ray spectroscopy for depth resolved elemental analysis

    NASA Astrophysics Data System (ADS)

    Kanngießer, B.; Malzer, W.; Mantouvalou, I.; Sokaras, D.; Karydas, A. G.

    2012-02-01

    Quantitative X-ray fluorescence (XRF) and particle induced X-ray emission (PIXE) techniques have been developed mostly for the elemental analysis of homogeneous bulk or very simple layered materials. Further on, the microprobe version of both techniques is applied for 2D elemental mapping of surface heterogeneities. At typical XRF/PIXE fixed geometries and exciting energies (15-25 keV and 2-3 MeV, respectively), the analytical signal (characteristic X-ray radiation) emanates from a variable but rather extended depth within the analyzed material, according to the exciting probe energy, set-up geometry, specimen matrix composition and analyte. Consequently, the in-depth resolution offered by XRF and PIXE techniques is rather limited for the characterization of materials with micrometer-scale stratigraphy or 3D heterogeneous structures. This difficulty has been over-passed to some extent in the case of an X-ray or charged particle microprobe by creating the so-called confocal geometry. The field of view of the X-ray spectrometer is spatially restricted by a polycapillary X-ray lens within a sensitive microvolume formed by the two inter-sectioned focal regions. The precise scanning of the analyzed specimen through the confocal microvolume results in depth-sensitive measurements, whereas the additional 2D scanning microprobe possibilities render to element-specific 3D spatial resolution (3D micro-XRF and 3D micro-PIXE). These developments have contributed since 2003 to a variety of fields of applications in environmental, material and life sciences. In contrast to other elemental imaging methods, no size restriction of the objects investigated and the non-destructive character of analysis have been found indispensable for cultural heritage (CH) related applications. The review presents a summary of the experimental set-up developments at synchrotron radiation beamlines, particle accelerators and desktop spectrometers that have driven methodological developments and applications of confocal X-ray microscopy including depth profiling speciation studies by means of confocal X-ray absorption near edge structure (XANES) spectroscopy. The solid mathematical formulation developed for the quantitative in-depth elemental analysis of stratified materials is exemplified and depth profile reconstruction techniques are discussed. Selected CH applications related to the characterization of painted layers from paintings and decorated artifacts (enamels, glasses and ceramics), but also from the study of corrosion and patina layers in glass and metals, respectively, are presented. The analytical capabilities, limitations and future perspectives of the two variants of the confocal micro X-ray spectroscopy, 3D micro-XRF and 3D micro-PIXE, with respect to CH applications are critically assessed and discussed.

  11. Reflected Glory

    ERIC Educational Resources Information Center

    Forster, Colin

    2006-01-01

    The scientific model of how people see things is far removed from children's real-world experience. They know that light is needed in order to see an object, but may not know that light is reflected off the object and some of that light enters the eyes. In this article, the author explores children's understanding of reflection and how to develop…

  12. Optimal detection pinhole for lowering speckle noise while maintaining adequate optical sectioning in confocal reflectance microscopes.

    PubMed

    Glazowski, Christopher; Rajadhyaksha, Milind

    2012-08-01

    Coherent speckle influences the resulting image when narrow spectral line-width and single spatial mode illumination are used, though these are the same light-source properties that provide the best radiance-to-cost ratio. However, a suitable size of the detection pinhole can be chosen to maintain adequate optical sectioning while making the probability density of the speckle noise more normal and reducing its effect. The result is a qualitatively better image with improved contrast, which is easier to read. With theoretical statistics and experimental results, we show that the detection pinhole size is a fundamental parameter for designing imaging systems for use in turbid media. PMID:23224184

  13. Optimal detection pinhole for lowering speckle noise while maintaining adequate optical sectioning in confocal reflectance microscopes

    PubMed Central

    Glazowski, Christopher; Rajadhyaksha, Milind

    2012-01-01

    Abstract. Coherent speckle influences the resulting image when narrow spectral line-width and single spatial mode illumination are used, though these are the same light-source properties that provide the best radiance-to-cost ratio. However, a suitable size of the detection pinhole can be chosen to maintain adequate optical sectioning while making the probability density of the speckle noise more normal and reducing its effect. The result is a qualitatively better image with improved contrast, which is easier to read. With theoretical statistics and experimental results, we show that the detection pinhole size is a fundamental parameter for designing imaging systems for use in turbid media. PMID:23224184

  14. Confocal microscopic analysis of optical crosstalk in GaN micro-pixel light-emitting diodes

    NASA Astrophysics Data System (ADS)

    Li, K. H.; Cheung, Y. F.; Cheung, W. S.; Choi, H. W.

    2015-10-01

    The optical crosstalk phenomenon in GaN micro-pixel light-emitting diodes (LED) has been investigated by confocal microscopy. Depth-resolved confocal emission images indicate light channeling along the GaN and sapphire layers as the source of crosstalk. Thin-film micro-pixel devices are proposed, whereby the light-trapping sapphire layers are removed by laser lift-off. Optical crosstalk is significantly reduced but not eliminated due to the remaining GaN layer. Another design involving micro-pixels which are completely isolated is further proposed; such devices exhibited low-noise and enhanced optical performances, which are important attributes for high-density micro-pixel LED applications including micro-displays and multi-channel optical communications.

  15. Three-dimensional observation of SiO2 hollow spheres with a double-shell structure using aberration-corrected scanning confocal electron microscopy.

    PubMed

    Zhang, Xiaobin; Takeguchi, Masaki; Hashimoto, Ayako; Mitsuishi, Kazutaka; Wang, Peng; Nellist, Peter D; Kirkland, Angus I; Tezuka, Meguru; Shimojo, Masayuki

    2012-06-01

    Optical sectioning using scanning confocal electron microscopy (SCEM) is a new three-dimensional (3D) imaging technique which promises improved depth resolution, particularly for laterally extended objects. Using a stage-scanning system to move the specimen in three dimensions, two-dimensional (2D) images sliced from any plane in XYZ space can be obtained in shorter acquisition times than those required for conventional electron tomography. In this paper, a double aberration-corrected SCEM used in annular dark-field mode was used to observe the 3D structure of SiO(2) hollow spheres fabricated by a carbon template method. The double-shell structure of the sample was clearly reflected in both XY- and XZ-sliced images. However, elongation along the optical axis was still evident in the XZ-sliced images even when double aberration correctors were used. Application of a deconvolution technique to the experimental XZ-sliced images reduced the elongated shell thicknesses of the SiO(2) sphere by 40-50% and the selectivity of information at a certain sample depth was also enhanced. Subsequently, 3D reconstruction by stacking the deconvoluted slice images restored the spherical surface of a SiO(2) sphere. PMID:22460388

  16. Multimodal optical workstation for simultaneous linear, nonlinear microscopy and nanomanipulation: Upgrading a commercial confocal inverted microscope

    PubMed Central

    Mathew, Manoj; Santos, Susana I. C. O.; Zalvidea, Dobryna; Loza-Alvarez, Pablo

    2009-01-01

    In this work we propose and build a multimodal optical workstation that extends a commercially available confocal microscope (Nikon Confocal C1-Si) to include nonlinear?multiphoton microscopy and optical manipulation?stimulation tools such as nanosurgery. The setup allows both subsystems (confocal and nonlinear) to work independently and simultaneously. The workstation enables, for instance, nanosurgery along with simultaneous confocal and brightfield imaging. The nonlinear microscopy capabilities are added around the commercial confocal microscope by exploiting all the flexibility offered by this microscope and without need for any mechanical or electronic modification of the confocal microscope systems. As an example, the standard differential interference contrast condenser and diascopic detector in the confocal microscope are readily used as a forward detection mount for second harmonic generation imaging. The various capabilities of this workstation, as applied directly to biology, are demonstrated using the model organism Caenorhabditis elegans. PMID:19655950

  17. Automated spherical aberration correction in scanning confocal microscopy.

    PubMed

    Yoo, H W; van Royen, M E; van Cappellen, W A; Houtsmuller, A B; Verhaegen, M; Schitter, G

    2014-12-01

    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 to compensate for spherical aberrations due to coverslip thickness mismatch. With a motorized coverslip correction collar, the adjustment procedure consists of xz image scans, image processing, correction quality evaluation, the mismatch estimation, and eventually the optimal adjustment of the correction collar. For fast correction with less photodamage, coarse-fine Gaussian fitting algorithms are proposed and evaluated with various specimen for their estimation accuracy. The benefits of the proposed automated correction are demonstrated for various coverslips with biological specimens, showing the optimized resolution of the confocal microscope. PMID:25554300

  18. Classification of billiard motions in domains bounded by confocal parabolas

    SciTech Connect

    Fokicheva, V V

    2014-08-01

    We consider the billiard dynamical system in a domain bounded by confocal parabolas. We describe such domains in which the billiard problem can be correctly stated. In each such domain we prove the integrability for the system, analyse the arising Liouville foliation, and calculate the invariant of Liouville equivalence--the so-called marked molecule. It turns out that billiard systems in certain parabolic domains have the same closures of solutions (integral trajectories) as the systems of Goryachev-Chaplygin-Sretenskii and Joukowski at suitable energy levels. We also describe the billiard motion in noncompact domains bounded by confocal parabolas, namely, we describe the topology of the Liouville foliation in terms of rough molecules. Bibliography: 16 titles.

  19. Anabaena cell ageing monitored with confocal fluorescence spectroscopy.

    PubMed

    Ke, Shan; Bindokas, Vytas; Haselkorn, Robert

    2015-01-01

    Cyanobacteria use a sophisticated system of pigments to collect light energy across the visible spectrum for photosynthesis. The pigments are assembled in structures called phycobilisomes, composed of phycoerythrocyanin, phycocyanin and allophycocyanin, which absorb energy and transfer it to chlorophyll in photosystem II reaction centres. All of the components of this system are fluorescent, allowing sensitive measurements of energy transfer using single cell confocal fluorescence microscopy. The native pigments can be interrogated without the use of reporters. Here, we use confocal fluorescence microscopy to monitor changes in the efficiency of energy transfer as single cells age, between the time they are born at cell division until they are ready to divide again. Alteration of fluorescence was demonstrated to change with the age of the cyanobacterial cell. PMID:25378560

  20. [Calibration Procedure of Laser Confocal Micro-Raman Spectrometer].

    PubMed

    Zhao, Ying-chun; Ren, Ling-ling; Wei, Wei-sheng; Yao, Ya-xuan

    2015-09-01

    As a common spectral characterization technique, Raman spectroscopy is widely used and has a specified calibration procedure. Based on laser confocal micro-Raman spectrometer, in this paper, we briefly introduced the principle, configuration and main components of Raman spectrometer. In addition, the calibration procedures were also presented, with an emphasis on the calibration of spectrometer (spectrograph) and that of excitation laser wavelength. On the basis of conventional calibration method, a novel and more accurate method was proposed to obtain the actual excitation wavelength, that is, calibration at the point of Raman shift ??=0. Using this novel calibration method of excitation wavelength, Raman frequency shift values of sulfur were measured, and compared with the standard values from American Society Testing and Materials (ASTM). As a result, the measured values after calibration were consistent with those ASTM values, which indicated that the calibration method is accurate. Thus, a more reasonable calibration procedure of the laser confocal micro-Raman spectrometer was provided. PMID:26669164

  1. Application of Near Infrared Reflectance Spectroscopy on Determination of Moisture, Total oil and Protein Contents of In-shell Peanuts

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Moisture, total oil and protein content of peanuts are important factors in peanut grading. A method that could rapidly and nondestructively measure these parameters for in-shell peanuts would be extremely useful. NIR reflectance spectroscopy was used to analyze the moisture, total oil and protein ...

  2. Confocal foveated endomicroscope for the detection of esophageal carcinoma

    PubMed Central

    Shadfan, Adam; Hellebust, Anne; Richards-Kortum, Rebecca; Tkaczyk, Tomasz

    2015-01-01

    By mimicking the variable resolution of the human eye, a newly designed foveated endomicroscopic objective shows the potential to improve current endoscopic based techniques of identifying abnormal tissue in the esophagus and colon. The prototype miniature foveated objective is imaged with a confocal microscope to provide large field of view images combined with a high resolution central region to rapidly observe morphological structures associated with cancer development in a mouse model. PMID:26203363

  3. Photothermal Confocal Spectromicroscopy of Multiple Cellular Chromophores and Fluorophores

    PubMed Central

    Nedosekin, D.A.; Galanzha, E.I.; Ayyadevara, Srinivas; Shmookler Reis, Robert J.; Zharov, V.P.

    2012-01-01

    Confocal fluorescence microscopy is a powerful biological tool providing high-resolution, three-dimensional (3D) imaging of fluorescent molecules. Many cellular components are weakly fluorescent, however, and thus their imaging requires additional labeling. As an alternative, label-free imaging can be performed by photothermal (PT) microscopy (PTM), based on nonradiative relaxation of absorbed energy into heat. Previously, little progress has been made in PT spectral identification of cellular chromophores at the 3D microscopic scale. Here, we introduce PTM integrating confocal thermal-lens scanning schematic, time-resolved detection, PT spectral identification, and nonlinear nanobubble-induced signal amplification with a tunable pulsed nanosecond laser. The capabilities of this confocal PTM were demonstrated for high-resolution 3D imaging and spectral identification of up to four chromophores and fluorophores in live cells and Caenorhabditis elegans. Examples include cytochrome c, green fluorescent protein, Mito-Tracker Red, Alexa-488, and natural drug-enhanced or genetically engineered melanin as a PT contrast agent. PTM was able to guide spectral burning of strong absorption background, which masked weakly absorbing chromophores (e.g., cytochromes in the melanin background). PTM provided label-free monitoring of stress-related changes to cytochrome c distribution, in C. elegans at the single-cell level. In nonlinear mode ultrasharp PT spectra from cyt c and the lateral resolution of 120 nm during calibration with 10-nm gold film were observed, suggesting a potential of PTM to break through the spectral and diffraction limits, respectively. Confocal PT spectromicroscopy could provide a valuable alternative or supplement to fluorescence microscopy for imaging of nonfluorescent chromophores and certain fluorophores. PMID:22325291

  4. Confocal microscopy study of colloidal sedimentation and crystallization 

    E-print Network

    Beckham, Richard Edward

    2009-05-15

    ; (4) the replacement of ammonia with dodecylamine in St?ber synthesis; and (5) the use of an amine functionalized silane to bind poly(isobutylene) to the surface of silica particles. New methods that were developed include: (1) a Monte Carlo... with the confocal microscope. Recently, two-micron silica particles have been sterically stabilized in toluene with a grafted layer of poly(isobutylene), and these particles do not appear to exhibit electrostatic repulsion. This success, combined...

  5. Development and application of variable angle internal reflection Raman spectroscopy for vibrationally specific depth-profiling of polymer thin films

    NASA Astrophysics Data System (ADS)

    Fontaine, Norman Henry

    1997-10-01

    Techniques which can be used to obtain depth-resolved information on the thermodynamics at polymer-polymer and polymer-wall interfaces, and of small molecule diffusion in polymers, are of particular interest to industry. Optical methods which are sensitive to molecular vibrations (such as internal reflection Raman spectroscopy) are advantageous because they can non- destructively probe molecular content, orientation, and polarity of the local environment in a sample. However, while optical internal reflection depth-profiling methods have been reported, they have never progressed beyond the demonstration stage. In this work, the theory and methodology of internal reflection spectroscopy are developed and optimized into a rigorous field-controlled spectroscopic technique. A novel asymmetric internal reflection element (IRE) is introduced which traps back-reflections, allowing precise evanescent and standing wave probe-field control in the sample for all angles of incidence. It is demonstrated that a Gaussian laser beam will best approximate an infinite homogeneous plane wave when the IRE/sample interface lies in the paraxial-Fraunhofer region (far- field) of the beam path. Calibration methods are presented, sources of systematic errors are identified, and the angular resolution limit (ARL) is introduced as a measure of the field control developed in a sample by any internal reflection method. A general model of Raman scattering and photon detection from multi-layer thin films is developed. A new and generalized operator based transfer matrix method is developed and applied to electromagnetic field and diffusion computations in multi-layer systems. Total internal reflection spectroscopy is extended to include sub-critical angles of incidence, where resonant field enhancements generate large and selective amplification of the probe-field intensity within the layers of the sample. Fitting these resonances to the model spectral intensities allows unique determination of the location of buried interfaces in micron-sized polymer multi-layers with nanometer scale precision and the refractive indices of the layers with precision of /Delta n/approx/pm 0.0001. The Raman active molecular content of each optically distinct layer of the film is determinable simultaneously with the optical properties. Resonant mode VAIRRS studies of poly(methyl methacrylate) films spun-cast from toluene and then dried under ambient conditions have shown evidence for toluene diffusion concurrent with a rotationally hindered relaxation of oriented ester side groups about the polymer backbone. Low temperature annealing (?87oC) has shown evidence that this hindered rotational relaxation may be reversible. VAIRRS study of a polystyrene/poly(methyl methacrylate) bi-layer has detected evidence for toluene diffusion across the buried polymer-polymer interface.

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

    PubMed

    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. PMID:25828656

  7. Correlated confocal and super-resolution imaging by VividSTORM.

    PubMed

    Barna, László; Dudok, Barna; Miczán, Vivien; Horváth, András; László, Zsófia I; Katona, István

    2016-01-01

    Single-molecule localization microscopy (SMLM) is rapidly gaining popularity in the life sciences as an efficient approach to visualize molecular distribution with nanoscale precision. However, it has been challenging to obtain and analyze such data within a cellular context in tissue preparations. Here we describe a 5-d tissue processing and immunostaining procedure that is optimized for SMLM, and we provide example applications to fixed mouse brain, heart and kidney tissues. We then describe how to perform correlated confocal and 3D-superresolution imaging on these sections, which allows the visualization of nanoscale protein localization within labeled subcellular compartments of identified target cells in a few minutes. Finally, we describe the use of VividSTORM (http://katonalab.hu/index.php/vividstorm), an open-source software for correlated confocal and SMLM image analysis, which facilitates the measurement of molecular abundance, clustering, internalization, surface density and intermolecular distances in a cell-specific and subcellular compartment-restricted manner. The protocol requires only basic skills in tissue staining and microscopy. PMID:26716705

  8. Combining microtomy and confocal laser scanning microscopy for structural analyses of plant-fungus associations.

    PubMed

    Rath, Magnus; Grolig, Franz; Haueisen, Janine; Imhof, Stephan

    2014-05-01

    The serious problem of extended tissue thickness in the analysis of plant-fungus associations was overcome using a new method that combines physical and optical sectioning of the resin-embedded sample by microtomy and confocal microscopy. Improved tissue infiltration of the fungal-specific, high molecular weight fluorescent probe wheat germ agglutinin conjugated to Alexa Fluor® 633 resulted in high fungus-specific fluorescence even in deeper tissue sections. If autofluorescence was insufficient, additional counterstaining with Calcofluor White M2R or propidium iodide was applied in order to visualise the host plant tissues. Alternatively, the non-specific fluorochrome acid fuchsine was used for rapid staining of both, the plant and the fungal cells. The intricate spatial arrangements of the plant and fungal cells were preserved by immobilization in the hydrophilic resin Unicryl™. Microtomy was used to section the resin-embedded roots or leaves until the desired plane was reached. The data sets generated by confocal laser scanning microscopy of the remaining resin stubs allowed the precise spatial reconstruction of complex structures in the plant-fungus associations of interest. This approach was successfully tested on tissues from ectomycorrhiza (Betula pendula), arbuscular mycorrhiza (Galium aparine; Polygala paniculata, Polygala rupestris), ericoid mycorrhiza (Calluna vulgaris), orchid mycorrhiza (Limodorum abortivum, Serapias parviflora) and on one leaf-fungus association (Zymoseptoria tritici on Triticum aestivum). The method provides an efficient visualisation protocol applicable with a wide range of plant-fungus symbioses. PMID:24249491

  9. Scanning a microhabitat: plant-microbe interactions revealed by confocal laser microscopy

    PubMed Central

    Cardinale, Massimiliano

    2014-01-01

    No plant or cryptogam exists in nature without microorganisms associated with its tissues. Plants as microbial hosts are puzzles of different microhabitats, each of them colonized by specifically adapted microbiomes. The interactions with such microorganisms have drastic effects on the host fitness. Since the last 20 years, the combination of microscopic tools and molecular approaches contributed to new insights into microbe-host interactions. Particularly, confocal laser scanning microscopy (CLSM) facilitated the exploration of microbial habitats and allowed the observation of host-associated microorganisms in situ with an unprecedented accuracy. Here I present an overview of the progresses made in the study of the interactions between microorganisms and plants or plant-like organisms, focusing on the role of CLSM for the understanding of their significance. I critically discuss risks of misinterpretation when procedures of CLSM are not properly optimized. I also review approaches for quantitative and statistical analyses of CLSM images, the combination with other molecular and microscopic methods, and suggest the re-evaluation of natural autofluorescence. In this review, technical aspects were coupled with scientific outcomes, to facilitate the readers in identifying possible CLSM applications in their research or to expand their existing potential. The scope of this review is to highlight the importance of confocal microscopy in the study of plant-microbe interactions and also to be an inspiration for integrating microscopy with molecular techniques in future researches of microbial ecology. PMID:24639675

  10. Probe-based confocal laser endomicroscopy in head and neck malignancies: early preclinical experience

    NASA Astrophysics Data System (ADS)

    Englhard, Anna; Girschick, Susanne; Mack, Brigitte; Volgger, Veronika; Gires, Oliver; Conderman, Christian; Stepp, Herbert; Betz, Christian Stephan

    2013-06-01

    Background: Malignancies of the upper aerodigestive tract (UADT) are conventionally diagnosed by white light endoscopy, biopsy and histopathology. Probe-based Confocal Laser Endomicroscopy (pCLE) is a novel non-invasive technique which offers in vivo surface and sub-surface imaging of tissue. It produces pictures of cellular architecture comparable to histology without the need for biopsy. It has already been successfully used in different clinical subspecialties to help in the diagnosis and treatment planning of inflammatory and neoplastic diseases. PCLE needs to be used in combination with specific or non-specific contrast agents. In this study we evaluated the potential use of pCLE in combination with non-specific and specific contrast agents to distinguish between healthy mucosa and invasive carcinoma. Methods: Tissue samples from healthy mucosa and squamous cell carcinoma of the head and neck were taken during surgery. After topical application of three different contrast agents, samples were examined using different pCLE-probes and a Confocal Laser Scanning Microscope (CLSM). Images were then compared to the corresponding histological slides and cryosections. Results: Initial results show that pCLE in combination with fluorophores allows visualization of cellular and structural components. Imaging of different layers was possible using three distinct pCLEprobes. Conclusion: pCLE is a promising non-invasive technique that may be a useful adjunct in the evaluation, diagnosis and treatment planning of head and neck malignancies.

  11. Quantitative confocal fluorescence microscopy of dynamic processes by multifocal fluorescence correlation spectroscopy

    NASA Astrophysics Data System (ADS)

    Krmpot, Aleksandar J.; Nikoli?, Stanko N.; Vitali, Marco; Papadopoulos, Dimitrios K.; Oasa, Sho; Thyberg, Per; Tisa, Simone; Kinjo, Masataka; Nilsson, Lennart; Gehring, Walter J.; Terenius, Lars; Rigler, Rudolf; Vukojevic, Vladana

    2015-07-01

    Quantitative confocal fluorescence microscopy imaging without scanning is developed for the study of fast dynamical processes. The method relies on the use of massively parallel Fluorescence Correlation Spectroscopy (mpFCS). Simultaneous excitation of fluorescent molecules across the specimen is achieved by passing a single laser beam through a Diffractive Optical Element (DOE) to generate a quadratic illumination matrix of 32×32 light sources. Fluorescence from 1024 illuminated spots is detected in a confocal arrangement by a matching matrix detector consisting of the same number of single-photon avalanche photodiodes (SPADs). Software was developed for data acquisition and fast autoand cross-correlation analysis by parallel signal processing using a Graphic Processing Unit (GPU). Instrumental performance was assessed using a conventional single-beam FCS instrument as a reference. Versatility of the approach for application in biomedical research was evaluated using ex vivo salivary glands from Drosophila third instar larvae expressing a fluorescently-tagged transcription factor Sex Combs Reduced (Scr) and live PC12 cells stably expressing the fluorescently tagged mu-opioid receptor (MOPeGFP). We show that quantitative mapping of local concentration and mobility of transcription factor molecules across the specimen can be achieved using this approach, which paves the way for future quantitative characterization of dynamical reaction-diffusion landscapes across live cells/tissue with a submillisecond temporal resolution (presently 21 ?s/frame) and single-molecule sensitivity.

  12. Design of a confocal fluorescence microscope: space saving and affordable

    NASA Astrophysics Data System (ADS)

    Bechtel, Christin; Knobbe, Jens; Grüger, Heinrich; Lakner, Hubert; Reichert, Fabian

    2012-10-01

    Although confocal fluorescence laser scanning microscopy is a widely used technique in biology, these microscopes are at present uncommon in medical diagnostics. However laser scanning fluorescence microscopy is a non-invasive imaging technique that allows depth resolved investigations of skin disorders. High costs and large outline are factors which impede the establishment of this technology in medical practice. To overcome this obstacle, we have designed a portable confocal laser scanning fluorescence microscope and realized an optical demonstration set-up, offering a field of view of 500?m x 500?m. The microscope is based on a dual axis MEMS mirror where the confocal character of the system resides in the use of the same path for illumination and detection with the rejection of out-of-focus light by a pinhole. Illumination is provided by a laser and the fluorescence light is separated from the illumination light by a filter, before being detected. The ability to perform cross-sectional imaging of fluorescence specimen will be given by an integrated z-shifter.

  13. Quantification of Multilayer Samples by Confocal {mu}XRF

    SciTech Connect

    Perez, R. Daniel; Sanchez, H. J.; Rubio, M.; Perez, C. A.

    2009-01-29

    The confocal setup consists of x-ray lenses in the excitation as well as in the detection channel. In this configuration, a micro volume defined by the overlap of the foci of both x-ray lenses is analyzed. Scanning this micro volume through the sample, 1-3 dimensional studies can be performed. For intermediate thin homogeneous layers a scanning in the normal direction to the surface sample provides information of its thickness and elemental composition. For multilayer samples it also provides the order of each layer in the stratified structure. For the confocal setup, we used a glass monocapillary in the excitation channel and a monolithic half polycapillary in the detection channel. The experiment was carried out at the D09B beamline of the LNLS using white beam. In the present work, a new algorithm was applied to analyze in detail by confocal {mu}XRF a sample of three paint layers on a glass substrate. Using the proposed algorithm, information about thickness and elemental densities was obtained for each layer of these samples.

  14. The size control of silver nanocrystals with different polyols and its application to low-reflection coating materials

    NASA Astrophysics Data System (ADS)

    Park, Keum Hwan; Im, Sang Hyuk; Park, O. Ok

    2011-01-01

    The size of silver nanocrystals in polyol synthesis can be simply controlled by tuning the viscosity of the reaction medium such as ethylene glycol, 1,2-propanediol, 1,4-butanediol and 1,5-pentanediol. We found that a higher viscose medium (1,5-pentanediol) led to monodispersed smaller particles thanks to the slow addition of silver atoms into the nuclei. Size-controlled silver nanocrystals of 30 nm were obtained in a viscosity controlled medium of 1,5-pentanediol to synthesize a low refractive index filler by coating with silica and subsequent etching of the silver core. The coated low-reflection layer from the hollow silica nanoparticles on polyethylene terephthalate (PET) film can greatly reduce the reflection of the PET film from 10% to 2% over the entire visible region.

  15. Parameterization of aerosol and cirrus cloud effects on reflected sunlight spectra measured from space: application of the equivalence theorem.

    PubMed

    Bril, Andrey; Oshchepkov, Sergey; Yokota, Tatsuya; Inoue, Gen

    2007-05-01

    An original methodology to account for aerosol and cirrus cloud contributions to reflected sunlight is described. This method can be applied to the problem of retrieving greenhouse gases from satellite-observed data and is based on the equivalence theorem with further parameterization of the photon path-length probability density function (PPDF). Monte Carlo simulation was used to validate this parameterization for a vertically nonhomogeneous atmosphere including an aerosol layer and cirrus clouds. Initial approximation suggests that the PPDF depends on four parameters that can be interpreted as the effective cloud height, cloud relative reflectance, and two additional factors to account for photon path-length distribution under the cloud. We demonstrate that these parameters can be efficiently retrieved from the nadir radiance measured in the oxygen A-band and from the H(2)O-saturated area of the CO(2) 2.0 microm spectral band. PMID:17429457

  16. The NIST Robotic Optical Scatter Instrument (ROSI) and its application to BRDF measurements of diffuse reflectance standards for remote sensing

    NASA Astrophysics Data System (ADS)

    Patrick, Heather J.; Zarobila, Clarence J.; Germer, Thomas A.

    2013-09-01

    We describe the robotic optical scatter instrument (ROSI), a new robotic arm-based goniometer for in-plane and outof- plane reflectance and bidirectional reflectance distribution function (BRDF) measurements of surfaces. The goniometer enables BRDF measurements to be made at nearly any combination of incident and scattering angles, without obstruction from frames or cradles that occur in traditional goniometers made of nested rotation stages. We present exploratory measurements of in-plane and hemispherically-scanned out-of-plane BRDF on a sintered white polytetrafluoroethylene (PTFE) sample using a supercontinuum fiber laser-based tunable light source operated at a wavelength of 550 nm, in order to demonstrate the capabilities of the system. An initial assessment of uncertainties is presented.

  17. Application of Variable Angle Total Internal Reflection Fluorescence Microscopy to Investigate Protein Dynamics in Intact Plant Cells.

    PubMed

    Wan, Yinglang; Xue, Yiqun; Li, Ruili; Lin, Jinxing

    2016-01-01

    Variable angle total internal reflection fluorescence microscopy (VA-TIRFM) is an optical method to observe the molecular events occurring in an extremely thin region near the plasma membrane. Recently, the VA-TIRFM technique has been widely used to study fluorescently labeled target molecules in living animal and plant cells. Here, we describe the optical principle of the VA-TIRFM technique and provide a detailed experimental procedure for the study of living plant cells. PMID:26577785

  18. In vivo detection of experimental ulcerative colitis in rats using fiberoptic confocal imaging (FOCI).

    PubMed

    McLaren, W; Anikijenko, P; Barkla, D; Delaney, T P; King, R

    2001-10-01

    Fiberoptic confocal imaging (FOCI) is a noninvasive microscopic technique that enables subsurface imaging of living tissue in vivo. The aim of the present study was to assess the suitability of FOCI for the in vivo detection of early subsurface changes in the mucosal architecture of the colon in a rat model of ulcerative colitis. Mild colitis was induced in Sprague-Dawley rats (180-250 g) by the oral ingestion of 5% (w/v) dextran sulfate sodium (DSS; Mr 40,000 Da) in drinking water. Control animals were provided with water ad libitum. After three, five or seven days of oral consumption of DSS, the mucosal surface of the colon of anesthetised rats was surgically exposed. Morphological changes in the mucosa were examined (Optiscan F900e personal confocal system with rigid endomicroscope attachment; excitation 488 nm argon ion laser, detection above 515 nm) following the topical application of a fluorescent dye (fluorescein, eosin, or acridine orange). Confocal images were correlated with conventional histology and clinical parameters including occult blood and stool consistency. Histological evaluation of colon sections demonstrated that DSS-induced colitis was characterized by focal loss of mucous crypts, loss of epithelial cells, and neutrophilic infiltration into the mucosa. The extent of mucosal damage was positively correlated with the time of ingestion of DSS. Morphological changes associated with disease activity could be detected microscopically in vivo using FOCI but were not evident by visual inspection of the colon surface. Acridine orange enabled imaging of the colonic crypts at the surface of the mucosa. Morphological changes associated with colitis, including inflammatory cell infiltrate, crypt loss, and crypt distortion, could be detected using this fluorophore. Application of fluorescein and eosin enabled subsurface imaging of the lamina propria surrounding the crypts; however, no change in structure was detected in association with colitic disease activity. This study has shown that the topical application of acridine orange enables in vivo imaging of early colitis in a rat model. FOCI may be suitable for the diagnosis and monitoring of human inflammatory bowel disease. PMID:11680607

  19. Light-trap design using multiple reflections and solid-angle attenuation - Application to a spaceborne electron spectrometer

    NASA Technical Reports Server (NTRS)

    Herrero, Federico A.

    1992-01-01

    The design and performance of a new light trap for a spaceborne electron spectrometer are described. The light trap has a measured photon-rejection ratio of 2 x 10 exp -11, allowing only one in 5 x 10 exp 10 incident photons to reach the sensitive area of the instrument. This rejection is more than sufficient because the ambient UV in earth orbit requires a rejection no better than 10 exp -8 to maintain the photon interference to less than 10 count/s. The light trap uses triple reflections to keep most of the light passing through the entrance slit away from the sensitive area of the spectrometer. It is shown that the average reflectance of all the internal surfaces must be less than 0.006, which is consistent with the data on the black coating applied to all surfaces. The analysis makes it possible to compare the photon contributions of each of the internal reflecting areas and to estimate the effective scattering width of the metallic electrode edge.

  20. Using confocal microscopy to characterize nanoplasmonic structures responsible for light transmission

    NASA Astrophysics Data System (ADS)

    Carvalho, Mariana T.; Bezerra, Marcel; Marega, Euclydes; Borges, Ben-Hur V.; Nunes, Frederico D.

    2013-03-01

    The optical properties of nanostructured metallic nanofilms have been extensively studied in last few years. It was observed, for a wide variety of structures an enhancement in the transmission that can be explained as resulting from surface plasmon polaritons (SPP) waves propagating at the interface between the metallic film and the surrounding dielectric and/or substrate. In this work we utilize confocal microscope images as a useful tool to characterize the optical response of a set of concentric nanorings in the presence of SPP waves. We show for the first time the influence of the metal thickness on the light intensity profile. Reflected and transmitted light for concentric nanorings were observed under excitation of different laser wavelengths (405-633nm) as well as white light. Microscopy imaging with polarized light showed not only the spatial pattern of the radiation transmitted through these apertures but also a significant dependence of these patterns on the film thickness. The behavior was theoretically analyzed via basic principles as well as numerical simulation with standard software. A possible explanation is describing each ring as a source of radiation formed by two dipole systems, one electric dipole aligned to the applied electric field and a second one, a magnetic dipole, associated to a loop-antenna having an azimuthally non-homogeneous current dependence. This preliminary model is an ongoing study which may be useful to explain the behavior of the transmitted light. Analysis also showed the potential of confocal microscope for imaging nanostructures as well as for quantitative information on SPP excitation.

  1. Fluorescence Correlation Spectroscopy: A Review of Biochemical and Microfluidic Applications

    PubMed Central

    Tian, Yu; Martinez, Michelle M.

    2011-01-01

    Over the years fluorescence correlation spectroscopy (FCS) has proven to be a useful technique that has been utilized in several fields of study. Although FCS initially suffered from poor signal to noise ratios, the incorporation of confocal microscopy has overcome this drawback and transformed FCS into a sensitive technique with high figures of merit. In addition, tandem methods have evolved to include dual-color cross-correlation, total internal reflection fluorescence correlation, and fluorescence lifetime correlation spectroscopy combined with time-correlated single photon counting. In this review, we discuss several applications of FSC for biochemical, microfluidic, and cellular investigations. PMID:21396180

  2. Corneal Confocal Microscopy Detects Early Nerve Regeneration in Diabetic Neuropathy After Simultaneous Pancreas and Kidney Transplantation

    PubMed Central

    Tavakoli, Mitra; Mitu-Pretorian, Maria; Petropoulos, Ioannis N.; Fadavi, Hassan; Asghar, Omar; Alam, Uazman; Ponirakis, Georgios; Jeziorska, Maria; Marshall, Andy; Efron, Nathan; Boulton, Andrew J.; Augustine, Titus; Malik, Rayaz A.

    2013-01-01

    Diabetic neuropathy is associated with increased morbidity and mortality. To date, limited data in subjects with impaired glucose tolerance and diabetes demonstrate nerve fiber repair after intervention. This may reflect a lack of efficacy of the interventions but may also reflect difficulty of the tests currently deployed to adequately assess nerve fiber repair, particularly in short-term studies. Corneal confocal microscopy (CCM) represents a novel noninvasive means to quantify nerve fiber damage and repair. Fifteen type 1 diabetic patients undergoing simultaneous pancreas–kidney transplantation (SPK) underwent detailed assessment of neurologic deficits, quantitative sensory testing (QST), electrophysiology, skin biopsy, corneal sensitivity, and CCM at baseline and at 6 and 12 months after successful SPK. At baseline, diabetic patients had a significant neuropathy compared with control subjects. After successful SPK there was no significant change in neurologic impairment, neurophysiology, QST, corneal sensitivity, and intraepidermal nerve fiber density (IENFD). However, CCM demonstrated significant improvements in corneal nerve fiber density, branch density, and length at 12 months. Normalization of glycemia after SPK shows no significant improvement in neuropathy assessed by the neurologic deficits, QST, electrophysiology, and IENFD. However, CCM shows a significant improvement in nerve morphology, providing a novel noninvasive means to establish early nerve repair that is missed by currently advocated assessment techniques. PMID:23002037

  3. Demeclocycline as a contrast agent for detecting brain neoplasms using confocal microscopy

    NASA Astrophysics Data System (ADS)

    Wirth, Dennis; Smith, Thomas W.; Moser, Richard; Yaroslavsky, Anna N.

    2015-04-01

    Complete resection of brain tumors improves life expectancy and quality. Thus, there is a strong need for high-resolution detection and microscopically controlled removal of brain neoplasms. The goal of this study was to test demeclocycline as a contrast enhancer for the intraoperative detection of brain tumors. We have imaged benign and cancerous brain tumors using multimodal confocal microscopy. The tumors investigated included pituitary adenoma, meningiomas, glioblastomas, and metastatic brain cancers. Freshly excised brain tissues were stained in 0.75?mg?ml-1 aqueous solution of demeclocyline. Reflectance images were acquired at 402?nm. Fluorescence signals were excited at 402?nm and registered between 500 and 540?nm. After imaging, histological sections were processed from the imaged specimens and compared to the optical images. Fluorescence images highlighted normal and cancerous brain cells, while reflectance images emphasized the morphology of connective tissue. The optical and histological images were in accordance with each other for all types of tumors investigated. Demeclocyline shows promise as a contrast agent for intraoperative detection of brain tumors.

  4. Multi-color miniature dual-axis confocal microscope for point-of-care pathology.

    PubMed

    Leigh, Steven Y; Liu, Jonathan T C

    2012-06-15

    We present a miniature microelectromechanical systems-based dual-axis confocal microscope capable of spatially coregistered fluorescence and reflectance imaging at multiple wavelengths. This device has a 10 mm diameter scan head with a 2 mm diameter tip for convenient use during surgery to guide tumor resection. The microscope has an adjustable focal depth of 20-200 micrometers and is capable of imaging with an axial resolution of 9 micrometers and in-plane resolution of 4 micrometers over a field of view of 450×450 micrometers. Simultaneous two-color imaging of individual optical sections is achieved by using a pair of grating-prism assemblies to compensate for chromatic dispersion in the 2 mm diameter gradient index relay lens at the distal tip of the device. Experimental measurements of the axial response of the microscope, as well as two-color images of a reflective bar target and fresh mouse brain tissues, demonstrate the performance of our device and its potential for multicolor in vivo optical sectioning microscopy. PMID:22739931

  5. Closure between apparent and inherent optical properties of the ocean with applications to the determination of spectral bottom reflectance

    NASA Astrophysics Data System (ADS)

    Ivey, James Edward

    This study focuses on comparing six different marine optical models, field measurements, and laboratory measurements. Inherent Optical Properties (IOPs) of the water column depend only on the constituents within the water, not on the ambient light field. Apparent Optical Properties (AOPs) depend both on IOPs and the geometric underwater light field resulting from solar irradiance. Absorption (a) and scattering (b) are IOPs. Scattering can be partitioned into backscattering (bb). Remote Sensing Reflectance (Rrs), the ratio of radiant light leaving the water to the light entering the water surface plane (Ed), is an AOP. Rrs is proportional to bb/(a + bb). Using this relationship, Rrs is inverted to determine both absorption and backscattering. The constituents contributing to both absorption and backscattering can then be further deconvolved using modeling techniques. The in situ instruments usually have a fixed path length while AOP measurement path length depends on the penetration and/or return of downwelling solar irradiance. As a consequence, AOP measurements use a longer path length than in situ instruments. If the path length of a direct IOP measurement instrument is too short, there may not be sufficient signal to determine a change in value. While the AOP inversions require more empirical assumptions to determine IOP values than in situ instruments, they provide a higher signal to noise ratio in clearer waters. This study defines closure as the statistical agreement between instruments and methods in order to determine the same optical property. No method is considered absolute truth. An Rrs inversion algorithm was best under most of the test stations for measuring IOP values. One exception was when bottom reflectance was significant, an inversion of diffuse attenuation (the change in the natural log of Ed over depth) was better for determining absorption and a field instrument was better for determining backscattering. The relationships between AOPs and IOPs provide estimates of unmeasured optical properties. A method was developed to determine the spectral reflectance of the bottom using IOP estimates and Rrs.

  6. Probe-based confocal laser endomicroscopy of the urinary tract: the technique.

    PubMed

    Chang, Timothy C; Liu, Jen-Jane; Liao, Joseph C

    2013-01-01

    Probe-based confocal laser endomicroscopy (CLE) is an emerging optical imaging technology that enables real-time in vivo microscopy of mucosal surfaces during standard endoscopy. With applications currently in the respiratory and gastrointestinal tracts, CLE has also been explored in the urinary tract for bladder cancer diagnosis. Cellular morphology and tissue microarchitecture can be resolved with micron scale resolution in real time, in addition to dynamic imaging of the normal and pathological vasculature. The probe-based CLE system (Cellvizio, Mauna Kea Technologies, France) consists of a reusable fiberoptic imaging probe coupled to a 488 nm laser scanning unit. The imaging probe is inserted in the working channels of standard flexible and rigid endoscopes. An endoscope-based CLE system (Optiscan, Australia), in which the confocal endomicroscopy functionality is integrated onto the endoscope, is also used in the gastrointestinal tract. Given the larger scope diameter, however, application in the urinary tract is currently limited to ex vivo use. Confocal image acquisition is done through direct contact of the imaging probe with the target tissue and recorded as video sequences. As in the gastrointestinal tract, endomicroscopy of the urinary tract requires an exogenenous contrast agent-most commonly fluorescein, which can be administered intravenously or intravesically. Intravesical administration is a well-established method to introduce pharmacological agents locally with minimal systemic toxicity that is unique to the urinary tract. Fluorescein rapidly stains the extracellular matrix and has an established safety profile. Imaging probes of various diameters enable compatibility with different caliber endoscopes. To date, 1.4 and 2.6 mm probes have been evaluated with flexible and rigid cystoscopy. Recent availability of a < 1 mm imaging probe opens up the possibility of CLE in the upper urinary tract during ureteroscopy. Fluorescence cystoscopy (i.e. photodynamic diagnosis) and narrow band imaging are additional endoscope-based optical imaging modalities that can be combined with CLE to achieve multimodal imaging of the urinary tract. In the future, CLE may be coupled with molecular contrast agents such as fluorescently labeled peptides and antibodies for endoscopic imaging of disease processes with molecular specificity. PMID:23354133

  7. A confocal three-dimensional micro X-ray scattering technology based on Rayleigh to Compton ratio for identifying materials with similar density and different weight percentages of low-Z elements

    NASA Astrophysics Data System (ADS)

    Li, Fangzuo; Liu, Zhiguo; Sun, Tianxi; Yang, Chaolin; Sun, Xuepeng; Sun, Weiyuan; He, Jialin; Ding, Xunliang

    2015-07-01

    A point-by-point Rayleigh to Compton scattering ratio (R/C) imaging for two polymer materials with similar density and different weight percentages of low-Z elements was carried out by using the confocal three-dimensional (3D) micro X-ray scatter tomographic technology based on polycapillary X-ray optics. This confocal 3D micro X-ray scatter tomographic technique was based on the confocal configuration of a polycapillary focusing X-ray lens (PFXRL) in the excitation channel and a polycapillary parallel X-ray lens (PPXRL) in the detection channel, which let only the X-rays scattered from the confocal micro-volume overlapped by the input focal spot of the PPXRL and the output focal spot of the PFXRL be detected by the detector. The main scope of this study was using the confocal 3D micro X-ray scattering tomography based on the R/C ratio to characterize and identify materials with nearly equal low density and different weight percentages of low-Z elements, as other radiological techniques are difficult to discriminate them for their very close attenuation coefficients ? . A mapping of R/C ratios for two thermoplastic polymer materials was obtained, which provided the spatially resolved distribution of their effective atom numbers, and their differences were accordingly presented. This confocal 3D micro X-ray scatter tomographic technique has potential applications in fields such as material identification, dosimetry, medical imaging, carbonation cancer, and so on.

  8. Three-dimensional image of hepatocellular carcinoma under confocal laser scanning microscope

    PubMed Central

    Zhang, Wang-Hai; Zhu, Shi-Neng; Lu, Shi-Lun; Huang, Ya-Lin; Zhao, Peng

    2000-01-01

    AIM: To investigate the application of confocal laser scanning microscopy (CLSM) in tumor pathology and three-dimensional (3-D) reconstruction by CLSM in pathologic specimens of hepatocellular carcinoma (HCC). METHODS: The 30 ?m thick sections were cut from the paraffin-embedded tissues of HCC, hyperplasia and normal liver, stained with DNA fluorescent probe YOYO-1 iodide and examined by CLSM to collect optical sections of nuclei and 3-D images reconstructed. RESULTS: HCC displayed chaotic arrangement of carcinoma cell nuclei, marked pleomorphism, indented and irregular nuclear surface, and irregular and coarse chromatin texture. CONCLUSION: The serial optical tomograms of CLSM can be used to create 3-D reconstruction of cancer cell nuclei. Such 3-D impressions might be helpful or even essential in making an accurate diagnosis. PMID:11819594

  9. Optimising performance of a confocal fluorescence microscope with a differential pinhole

    NASA Astrophysics Data System (ADS)

    Kakade, Rohan; Walker, John G.; Phillips, Andrew J.

    2016-01-01

    The signal-to-noise ratio (SNR)-resolution trade-off is of great importance to bio-imaging applications where the aim is to image the sample using as little light as possible without significantly sacrificing image quality. In this paper the inherent SNR-resolution tradeoff in Confocal Fluorescence Microscopy (CFM) systems is presented by means of an effective tradeoff curve. A CFM system that employs a differential pinhole detection scheme has recently been shown to offer increased resolution, but at the expense of SNR. An optimum profile for the differential pinhole is identified in this paper that offers improved performance over a conventional (circular pinhole) system. The performance enhancement is illustrated through computer simulation.

  10. Estimation of single cell volume from 3D confocal images using automatic data processing

    NASA Astrophysics Data System (ADS)

    Chorvatova, A.; Cagalinec, M.; Mateasik, A.; Chorvat, D., Jr.

    2012-06-01

    Cardiac cells are highly structured with a non-uniform morphology. Although precise estimation of their volume is essential for correct evaluation of hypertrophic changes of the heart, simple and unified techniques that allow determination of the single cardiomyocyte volume with sufficient precision are still limited. Here, we describe a novel approach to assess the cell volume from confocal microscopy 3D images of living cardiac myocytes. We propose a fast procedure based on segementation using active deformable contours. This technique is independent on laser gain and/or pinhole settings and it is also applicable on images of cells stained with low fluorescence markers. Presented approach is a promising new tool to investigate changes in the cell volume during normal, as well as pathological growth, as we demonstrate in the case of cell enlargement during hypertension in rats.

  11. Aerogel Track Morphology: Measurement, Three Dimensional Reconstruction and Particle Location using Confocal Laser Scanning Microscopy

    NASA Technical Reports Server (NTRS)

    Kearsley, A. T.; Ball, A. D.; Wozniakiewicz, P. A.; Graham, G. A.; Burchell, M. J.; Cole, M. J.; Horz, F.; See, T. H.

    2007-01-01

    The Stardust spacecraft returned the first undoubted samples of cometary dust, with many grains embedded in the silica aerogel collector . Although many tracks contain one or more large terminal particles of a wide range of mineral compositions , there is also abundant material along the track walls. To help interpret the full particle size, structure and mass, both experimental simulation of impact by shots and numerical modeling of the impact process have been attempted. However, all approaches require accurate and precise measurement of impact track size parameters such as length, width and volume of specific portions. To make such measurements is not easy, especially if extensive aerogel fracturing and discoloration has occurred. In this paper we describe the application and limitations of laser confocal imagery for determination of aerogel track parameters, and for the location of particle remains.

  12. Application FT-NIR in rapid estimation of soluble solids content of intact kiwifruits by reflectance mode

    NASA Astrophysics Data System (ADS)

    Ying, Yibin; Lu, Huishan; Fu, Xiaping; Liu, Yande; Xu, Huirong; Yu, Haiyan

    2005-11-01

    Nondestructive method of measuring soluble solids content (SSC) of kiwifruit was developed by Fourier transform near infrared (FT-NIR) reflectance and fiber optics. Also, the models describing the relationship between SSC and the NIR spectra of the fruit were developed and evaluated. To develop the models several different NIR reflectance spectra were acquired for each fruit from a commercial supermarket. Different spectra correction algorithms (standard normal variate (SNV), multiplicative signal correction (MSC)) were used in this work. The relationship between laboratory SSC and FT-NIR spectra of kiwifruits were analyzed via principle component regression (PCR) and partial least squares (PLS) regression method using TQ 6.2.1 quantitative software (Thermo Nicolet Co., USA). Models based on the different spectral ranges were compared in this research. The first derivative and second derivative were applied to all measured spectra to reduce the effects of sample size, light scattering, noise of instrument, etc. Different baseline correction methods were applied to improve the spectral data quality. Among them the second derivative method after baseline correction produced best noise removing capability and to obtain optimal calibration models. Total 480 NIR spectra were acquired from 120 kiwifruits and 90 samples were used to develop the calibration model, the rest samples were used to validate the model. Developed PLS model, which describes the relationship between SSC and NIR spectra, could predict SSC of 84 unknown samples with correlation coefficient of 0.9828 and SEP of 0.679 Brix.

  13. Optical properties of silicon carbide for astrophysical applications I. New laboratory infrared reflectance spectra and optical constants

    E-print Network

    K. M. Pitman; A. M. Hofmeister; A. B. Corman; A. K. Speck

    2008-03-10

    Silicon Carbide (SiC) optical constants are fundamental inputs for radiative transfer models of astrophysical dust environments. However, previously published values contain errors and do not adequately represent the bulk physical properties of the cubic (beta) SiC polytype usually found around carbon stars. We provide new, uncompromised optical constants for beta- and alpha-SiC derived from single-crystal reflectance spectra and investigate quantitatively whether there is any difference between alpha- and beta-SiC that can be seen in infrared spectra and optical functions. Previous optical constants for SiC do not reflect the true bulk properties, and they are only valid for a narrow grain size range. The new optical constants presented here will allow narrow constraints to be placed on the grain size and shape distribution that dominate in astrophysical environments. In addition, our calculated absorption coefficients are much higher than laboratory measurements, which has an impact on the use of previous data to constrain abundances of these dust grains.

  14. In vivo imaging of tumor angiogenesis using fluorescence confocal videomicroscopy.

    PubMed

    Fitoussi, Victor; Faye, Nathalie; Chamming's, Foucauld; Clement, Olivier; Cuenod, Charles-Andre; Fournier, Laure S

    2013-01-01

    Fibered confocal fluorescence in vivo imaging with a fiber optic bundle uses the same principle as fluorescent confocal microscopy. It can excite fluorescent in situ elements through the optical fibers, and then record some of the emitted photons, via the same optical fibers. The light source is a laser that sends the exciting light through an element within the fiber bundle and as it scans over the sample, recreates an image pixel by pixel. As this scan is very fast, by combining it with dedicated image processing software, images in real time with a frequency of 12 frames/sec can be obtained. We developed a technique to quantitatively characterize capillary morphology and function, using a confocal fluorescence videomicroscopy device. The first step in our experiment was to record 5 sec movies in the four quadrants of the tumor to visualize the capillary network. All movies were processed using software (ImageCell, Mauna Kea Technology, Paris France) that performs an automated segmentation of vessels around a chosen diameter (10 ?m in our case). Thus, we could quantify the 'functional capillary density', which is the ratio between the total vessel area and the total area of the image. This parameter was a surrogate marker for microvascular density, usually measured using pathology tools. The second step was to record movies of the tumor over 20 min to quantify leakage of the macromolecular contrast agent through the capillary wall into the interstitium. By measuring the ratio of signal intensity in the interstitium over that in the vessels, an 'index leakage' was obtained, acting as a surrogate marker for capillary permeability. PMID:24056503

  15. Confocal Scanner for Highly Sensitive Photonic Transduction of Nanomechanical Resonators

    NASA Astrophysics Data System (ADS)

    Diao, Zhu; Losby, Joseph E.; Sauer, Vincent T. K.; Westwood, Jocelyn N.; Freeman, Mark R.; Hiebert, Wayne K.

    2013-06-01

    We show that a simple confocal laser scanning system can be used to couple light through grating couplers into nanophotonic circuits. The coupling efficiency is better than 15% per coupler. Our technique avoids using multi-axis fibre stages and is especially advantageous when the nanophotonic circuit is kept in vacuum, e.g., for nanomechanical resonator displacement transduction. This was demonstrated by recording the resonant response of a nanomechanical doubly clamped beam embedded in a race-track optical cavity. The nanophotonic transduction offers an increase of two orders of magnitude in transduction responsivity compared with conventional free-space optical interferometry.

  16. Confocal Imaging of Biological Tissues Using Second Harmonic Generation

    SciTech Connect

    Kim, B-M.; Stoller, P.; Reiser, K.; Eichler, J.; Yan, M.; Rubenchik, A.; Da Silva, L.

    2000-03-06

    A confocal microscopy imaging system was devised to selectively detect Second harmonic signals generated by biological tissues. Several types of biological tissues were examined using this imaging system, including human teeth, bovine blood vessels, and chicken skin. All these tissues generated strong second harmonic signals. There is considerable evidence that the source of these signals in tissue is collagen. Collagen, the predominant component of most tissues, is known to have second order nonlinear susceptibility. This technique may have diagnostic usefulness in pathophysiological conditions characterized by changes in collagen structure including malignant transformation of nevi, progression of diabetic complications, and abnormalities in wound healing.

  17. Intravital confocal Raman microscopy with multiplexed SERS contrast agents

    NASA Astrophysics Data System (ADS)

    McVeigh, Patrick Z.; Wilson, Brian C.

    2012-03-01

    Intravital microscopy has been demonstrated to be a powerful technique for studying the delivery of contrast or therapeutic agents to tumours growing in a realistic 3D environment at high resolution. Surface enhanced Raman scattering (SERS)-active nanoparticle contrast agents provide the ability to improve in-vivo detection of tumour tissue through multiplex detection of their uniquely bright spectral lines. However, most work to date has been carried out in-vitro or in ex-vivo tissues. Here we present the results from confocal Raman microscopy in a dorsal skinfold window chamber in mice using SERS-active gold nanoparticle contrast agents directed towards an overexpressed tumour receptor tyrosine kinase.

  18. Confocal microscopy through a multimode fiber using optical correlation

    E-print Network

    Loterie, Damien; Psaltis, Demetri; Moser, Christophe

    2015-01-01

    We report on a method to obtain confocal imaging through multimode fibers using optical correlation. First, we measure the fiber's transmission matrix in a calibration step. This allows us to create focused spots at one end of the fiber by shaping the wavefront sent into it from the opposite end. These spots are scanned over a sample, and the light coming back from the sample via the fiber is optically correlated with the input pattern. We show that this achieves spatial selectivity in the detection. The technique is demonstrated on microbeads, a dried epithelial cell, and a cover glass.

  19. A coherent model for turbid imaging with confocal microscopy

    PubMed Central

    Glazowski, Christopher E.; Zavislan, James

    2013-01-01

    We present an engineering model of coherent imaging within a turbid volume, such as human tissues, with a confocal microscope. The model is built to analyze the statistical effect of aberrations and multiply scattered light on the resulting image. Numerical modeling of theory is compared with experimental results. We describe the construction of a stable phantom that represents the statistical effect of object turbidity on the image recorded. The model and phantom can serve as basis for system optimization in turbid imaging. PMID:23577285

  20. A miniature confocal Raman probe for endoscopic use

    NASA Astrophysics Data System (ADS)

    Day, J. C. C.; Bennett, R.; Smith, B.; Kendall, C.; Hutchings, J.; Meaden, G. M.; Born, C.; Yu, S.; Stone, N.

    2009-12-01

    Raman spectroscopy is a powerful tool for studying biochemical changes in the human body. We describe a miniature, confocal fibre optic probe intended to fit within the instrument channel of a standard medical endoscope. This probe has been optimized for the study of the carcinogenesis process of oesophageal malignancy. The optical design and fabrication of this probe is described including the anisotropic wet etching technique used to make silicon motherboards and jigs. Example spectra of PTFE reference samples are shown. Spectra with acquisition times as low as 2 s from resected oesophageal tissue are presented showing identifiable biochemical changes from various pathologies.

  1. High-speed confocal imaging of zebrafish heart development.

    PubMed

    Hove, Jay R; Craig, Michael P

    2012-01-01

    Due to its optical clarity and rudimentary heart structure (i.e., single atrium and ventricle), the zebrafish provides an excellent model for studying the genetic, morphological, and functional basis of normal and pathophysiological heart development in vivo. Recent advances in high-speed confocal imaging have made it possible to capture 2D zebrafish heart wall motions with temporal and spatial resolutions sufficient to characterize the highly dynamic intravital flow-structure environment. We have optimized protocols for introducing fluorescent tracer particles into the zebrafish cardiovasculature, imaging intravital heart wall motion, and performing high-resolution blood flow mapping that will be broadly useful in elucidating flow-structure relationships. PMID:22222541

  2. Spectroscopic Detection of Minerals in Martian Meteorites using Reflectance and Emittance Spectroscopy and Applications to Surface Mineralogy on Mars

    NASA Astrophysics Data System (ADS)

    Bishop, J. L.; Hamilton, V. E.

    2001-12-01

    Martian meteorites provide direct information about crustal rocks on Mars. In this study we are measuring reflectance and emittance spectra of multiple Martian meteorites in order to characterize the spectral properties of the minerals present and to develop comprehensive criteria for remote detection of rocks and minerals. Previous studies have evaluated mid-IR emittance spectra [Hamilton et al., 1997] and visible/IR reflectance spectra [Bishop et al., 1998a,b] of Martian meteorites independently. The current study includes comparisons of the visible/NIR and mid-IR spectral regions and also involves comparison of mid-IR spectra measured using biconical reflectance and thermal emission techniques. Combining spectral analyses of Martian meteorite chips and powders enables characterization of spectral bands for remote detection of potential source regions for meteorite-like rocks on the surface of Mars using both Thermal Emission Spectrometer (TES) datasets and visible/NIR datasets from past and future missions. Identification of alteration minerals in these meteorites also provides insights into the alteration processes taking place on Mars. Analysis of TES data on Mars has identified global regions of basaltic and andesitic surface material [e.g. Bandfield et al., 2000; Christensen et al., 2000]; however neither of these spectral endmembers corresponds well to the spectra of Martian meteorites. Some preliminary findings suggest that small regions on the surface of Mars may relate to meteorite compositions [e.g. Hoefen et al., 2000; Hamilton et al., 2001]. Part of the difficulty in identifying meteorite compositions on Mars may be due to surface alteration. We hope to apply the results of our spectroscopic analyses of Martian meteorites, as well as fresh and altered basaltic material, toward analysis of composition on Mars using multiple spectral datasets. References: Bandfield J. et al., Science 287, 1626, 2000. Bishop J. et al., MAPS 33, 699, 1998a. Bishop J. et al., MAPS 33, 693, 1998b. Christensen P., et al., JGR 105, 9609, 2000. Hamilton V. et al., JGR 102, 25593, 1997. Hamilton V. et al., LPSC XXXII, #2184, 2001. Hoefen T. et al., Bull. Am. Astron. Soc. 32, 1118, 2000.

  3. Development of a High Spectral Resolution Lidar (HSRL) Based on a Confocal Optical Filter for Aerosol Studies

    NASA Astrophysics Data System (ADS)

    Repasky, K. S.; Hoffman, D. S.; Reagan, J. A.; Carlsten, J.

    2010-12-01

    Aerosols are an important constituent in atmospheric composition affecting climate, weather, and air quality. Active remote sensing instruments provide tools for in-situ studies of atmospheric aerosols that can help understand the role of aerosols on the radiative forcing of the climate system. In this paper, the design and initial performance of a high spectral resolution lidar (HSRL) based on a unique confocal cavity for optically filtering the aerosol and molecular returns is presented. An injection seeded pulsed Nd:YAG laser with a fundamental and frequency doubled output is used as the laser transmitter for the HSRL. A small portion of fiber coupled injection seeded signal at 1064 nm is split before the laser oscillator and, after modulation using an acousto-optic modulator, is used to produce a discriminating signal for locking a confocal cavity that is resonant at the 1064 and 532 nm wavelengths to the injection seeded source. Light scattered in the atmosphere is collected using a commercial telescope. After the telescope, the 1064 nm light is split from the 532 nm light using a dielectric mirror with the 1064 nm light monitored using a PMT. The 532 nm light is launched into a multimode fiber. The output from the fiber is next incident on a beamsplitter with part of the light sent to a PMT to monitor the total return for the 532 nm channel. The light that passes through the beamsplitter is mode matched into a confocal optical cavity that allows the light scattered by the atmospheric aerosols to be transmitted while the light scattered from the atmospheric molecules is reflected. The transmitted light from the aerosol scattering is incident on a PMT while the reflected molecular signal is incident on a PMT. The transmission of the confocal cavity is monitored before and after the data collection using a continuous wave frequency doubled Nd:YAG laser that is fiber coupled. Data is collected and processed in the following manner. Each of the four voltage signals from the PMT’s are monitored using a high speed A/D card. The inversion of the 1064 nm return signal is completed using the Fernald inversion technique with the additional constraint of the aerosol optical depth. The HSRL 532 nm signal is inverted using a Rayleigh backscatter model along with the inversion techniques described by Shipley et al. (Applied Optics, V22, N23, 3716-3724, 1983) and Sroga et al. (Applied Optics, V22, N23, 3725-3732, 1983). This presentation will focus on the design of the confocal optical filter, the locking of the confocal optical filter to the laser transmitter, and the performance of the high spectral resolution channel at 532 nm. Data will be presented showing the molecular returns, the aerosol returns and the range resolved lidar ratio.

  4. Application of micro-attenuated total reflectance FTIR spectroscopy in the forensic study of questioned documents involving red seal inks.

    PubMed

    Dirwono, Warnadi; Park, Jin Sook; Agustin-Camacho, M R; Kim, Jiyeon; Park, Hyun-Mee; Lee, Yeonhee; Lee, Kang-Bong

    2010-06-15

    Red seal inks from Korea (6), Japan (1) and China (6) were studied to investigate the feasibility of micro-attenuated total reflectance (ATR) FTIR spectroscopy as a tool in the forensic study of questioned documents involving seal inks. The technique was able to differentiate red seal inks of similar colors and different manufacturers. Blind testing has shown that micro-ATR FTIR can identify the origin of the red seal inks with accuracy. Data gathered were converted to a database for future reference. Also, the technique was also successful in determining the sequence of heterogeneous line intersection from a personal seal and a ballpoint pen. The results show that micro-ATR FTIR can be a valuable non-destructive tool for the objective analysis of questioned documents involving different red seal inks. PMID:20413232

  5. Application of advanced seismic reflection imaging techniques to mapping permeable zones at Dixie Valley, Nevada. Final technical report

    SciTech Connect

    1998-02-18

    Multifold seismic reflection data from the Dixie Valley geothermal field in Nevada were reprocessed using a nonlinear optimization scheme called simulated annealing to model subsurface acoustic velocities, followed by a pre-stack Kirchhoff migration to produce accurate and detailed depth-migrated images of subsurface structure. In contrast to conventional processing techniques, these methods account for significant lateral variations in velocity and thus have the potential ability to image steeply-dipping faults and fractures that may affect permeability within geothermal fields. The optimization scheme develops two-dimensional velocity models to within 6% of velocities obtained from well and surface geologic data. Only the seismic data (i.e., first arrival times of P waves) are used to construct the velocity models and pre-stack migration images, and no other a priori assumptions are invoked. Velocities obtained by processing individual seismic tracks were integrated to develop a block diagram of velocities to 2.3 km depth within the Dixie Valley geothermal field. Details of the tectonic and stratigraphic structure allowed three dimensional extension of the interpretations of two dimensional data. Interpretations of the processed seismic data are compared with well data, surface mapping, and other geophysical data. The Dixie Valley fault along the southeastern Stillwater Range Piedmont is associated with a pronounced lateral velocity gradient that is interpreted to represent the juxtaposition of relatively low velocity basin-fill strata in the hanging wall against higher velocity crystalline rocks in the footwall. The down-dip geometry of the fault was evaluated by inverting arrival times from a negative move-out event, which we associate with the dipping fault plane, on individual shot gathers for seismic line SRC-3 for the location and depth of the associated reflection points on the fault.

  6. Contact lens-induced changes in the anterior eye as observed in vivo with the confocal microscope.

    PubMed

    Efron, Nathan

    2007-07-01

    The availability of the confocal microscope over the past decade has allowed clinicians and researchers to refine their understanding of the physiological and pathological basis of the ocular response to contact lens wear, and to discover previously unknown phenomena. Mucin balls, which form in the tear layer in patients wearing silicone hydrogel lenses, can penetrate the full thickness of the epithelium, leading to activation of keratocytes in the underlying anterior stroma. Epithelial cell size increases in response to all forms of lens wear, with lenses of higher oxygen transmissibility (Dk/t) interfering least with the normal process of epithelial desquamation. A higher density of Langerhans' cells is observed in the layer of the sub-basal nerve plexus among contact lens wearers, suggesting that contact lens wear may be altering the immune status of the cornea. Dark lines and folds are observed in the oedematous cornea in response to contact lens wear. Mechanical stimulation of the corneal surface, due to the physical presence of a contact lens, and the consequent release of inflammatory mediators, is the likely cause of reduced keratocyte density associated with lens wear. Highly reflective stromal 'microdot deposits' are observed throughout the entire stroma in higher numbers in lens wearers. 'Blebs' in the endothelium have a bright centre surrounded by a dark annular shadow; this appearance is explained with the aid of an optical model. The confocal microscope has considerable clinical utility in diagnosing Acanthamoeba and fungal keratitis. At the limbus, contact lenses can induce structural changes such as increases in basal epithelial cell size. An increased number of rolling leucocytes is observed in limbal vessels in response to low Dk/t lenses. It is concluded that the confocal microscope has considerable utility in contact lens research and practice. PMID:17498998

  7. Precise colloids with tunable interactions for confocal microscopy

    PubMed Central

    Kodger, Thomas E.; Guerra, Rodrigo E.; Sprakel, Joris

    2015-01-01

    Model colloidal systems studied with confocal microscopy have led to numerous insights into the physics of condensed matter. Though confocal microscopy is an extremely powerful tool, it requires a careful choice and preparation of the colloid. Uncontrolled or unknown variations in the size, density, and composition of the individual particles and interactions between particles, often influenced by the synthetic route taken to form them, lead to difficulties in interpreting the behavior of the dispersion. Here we describe the straightforward synthesis of copolymer particles which can be refractive index- and density-matched simultaneously to a non-plasticizing mixture of high dielectric solvents. The interactions between particles are accurately tuned by surface grafting of polymer brushes using Atom Transfer Radical Polymerization (ATRP), from hard-sphere-like to long-ranged electrostatic repulsion or mixed charge attraction. We also modify the buoyant density of the particles by altering the copolymer ratio while maintaining their refractive index match to the suspending solution resulting in well controlled sedimentation. The tunability of the inter-particle interactions, the low volatility of the solvents, and the capacity to simultaneously match both the refractive index and density of the particles to the fluid opens up new possibilities for exploring the physics of colloidal systems. PMID:26420044

  8. Biopsychronology: live confocal imaging of biopsies to assess organ function.

    PubMed

    Ashraf, Muhammad Imtiaz; Fries, Dietmar; Streif, Werner; Aigner, Felix; Hengster, Paul; Troppmair, Jakob; Hermann, Martin

    2014-08-01

    Prolonged ischemia (I) times caused by organ procurement and transport are main contributors to a decrease in organ function, which is further enhanced during reperfusion (R). This combined damage, referred to as ischemia-reperfusion injury (IRI), is a main contributor to delayed graft function, which leads to costly and lengthy follow-up treatments or even organ loss. Methods to monitor the status of a graft prior to transplantation are therefore highly desirable to optimize the clinical outcome. Here, we propose the use of fine needle biopsies, which are analyzed by real-time live confocal microscopy. Such a combination provides information about the functional and structural integrity of an organ within a few minutes. To confirm the feasibility of this approach, we obtained fine needle biopsies from rodent kidneys and exposed them to various stress conditions. Following the addition of a range of live stains, biopsies were monitored for mitochondrial function, cell viability, and tissue integrity using confocal live cell imaging. Our data demonstrate that this procedure requires minimal time for sample preparation and data acquisition and is well suitable to record organ damage resulting from unphysiological stress. PMID:24750326

  9. Precise colloids with tunable interactions for confocal microscopy

    NASA Astrophysics Data System (ADS)

    Kodger, Thomas E.; Guerra, Rodrigo E.; Sprakel, Joris

    2015-09-01

    Model colloidal systems studied with confocal microscopy have led to numerous insights into the physics of condensed matter. Though confocal microscopy is an extremely powerful tool, it requires a careful choice and preparation of the colloid. Uncontrolled or unknown variations in the size, density, and composition of the individual particles and interactions between particles, often influenced by the synthetic route taken to form them, lead to difficulties in interpreting the behavior of the dispersion. Here we describe the straightforward synthesis of copolymer particles which can be refractive index- and density-matched simultaneously to a non-plasticizing mixture of high dielectric solvents. The interactions between particles are accurately tuned by surface grafting of polymer brushes using Atom Transfer Radical Polymerization (ATRP), from hard-sphere-like to long-ranged electrostatic repulsion or mixed charge attraction. We also modify the buoyant density of the particles by altering the copolymer ratio while maintaining their refractive index match to the suspending solution resulting in well controlled sedimentation. The tunability of the inter-particle interactions, the low volatility of the solvents, and the capacity to simultaneously match both the refractive index and density of the particles to the fluid opens up new possibilities for exploring the physics of colloidal systems.

  10. Defect Band Luminescence Intensity Reversal as Related to Application of Anti-Reflection Coating on mc-Si PV Cells: Preprint

    SciTech Connect

    Guthrey, H.; Johnston, S.; Yan, F.; Gorman, B.; Al-Jassim, M.

    2012-06-01

    Photoluminescence (PL) imaging is widely used to identify defective regions within mc-Si PV cells. Recent PL imaging investigations of defect band luminescence (DBL) in mc-Si have revealed a perplexing phenomenon. Namely, the reversal of the DBL intensity in various regions of mc-Si PV material upon the application of a SiNx:H anti-reflective coating (ARC). Regions with low DBL intensity before ARC application often exhibit high DBL intensity afterwards, and the converse is also true. PL imaging alone cannot explain this effect. We have used high resolution cathodoluminescence (CL) spectroscopy and electron beam induced current (EBIC) techniques to elucidate the origin of the DBL intensity reversal. Multiple sub-bandgap energy levels were identified that change in peak position and intensity upon the application of the ARC. Using this data, in addition to EBIC contrast information, we provide an explanation for the DBL intensity reversal based on the interaction of the detected energy levels with the SiNx:H ARC application. Multiple investigations have suggested that this is a global problem for mc-Si PV cells. Our results have the potential to provide mc-Si PV producers a pathway to increased efficiencies through defect mitigation strategies.

  11. Selectively reflective transparent sheets

    NASA Astrophysics Data System (ADS)

    Waché, Rémi; Florescu, Marian; Sweeney, Stephen J.; Clowes, Steven K.

    2015-08-01

    We investigate the possibility to selectively reflect certain wavelengths while maintaining the optical properties on other spectral ranges. This is of particular interest for transparent materials, which for specific applications may require high reflectivity at pre-determined frequencies. Although there exist currently techniques such as coatings to produce selective reflection, this work focuses on new approaches for mass production of polyethylene sheets which incorporate either additives or surface patterning for selective reflection between 8 to 13 ? m. Typical additives used to produce a greenhouse effect in plastics include particles such as clays, silica or hydroxide materials. However, the absorption of thermal radiation is less efficient than the decrease of emissivity as it can be compared with the inclusion of Lambertian materials. Photonic band gap engineering by the periodic structuring of metamaterials is known in nature for producing the vivid bright colors in certain organisms via strong wavelength-selective reflection. Research to artificially engineer such structures has mainly focused on wavelengths in the visible and near infrared. However few studies to date have been carried out to investigate the properties of metastructures in the mid infrared range even though the patterning of microstructure is easier to achieve. We present preliminary results on the diffuse reflectivity using FDTD simulations and analyze the technical feasibility of these approaches.

  12. Neutron reflectivity

    NASA Astrophysics Data System (ADS)

    Cousin, Fabrice; Menelle, Alain

    2015-10-01

    The specular neutron reflectivity is a technique enabling the measurement of neutron scattering length density profile perpendicular to the plane of a surface or an interface, and thereby the profile of chemical composition. The characteristic sizes that are probed range from around 5 Å up 5000 Å. It is a scattering technique that averages information on the entire surface and it is therefore not possible to obtain information within the plane of the interface. The specific properties of neutrons (possibility of tuning the contrast by isotopic substitution, sensitivity to magnetism, negligible absorption, low energy of the incident neutrons) makes it particularly interesting in the fields of soft matter, biophysics and magnetic thin films. This course is a basic introduction to the technique and does not address the magnetic reflectivity. It is composed of three parts describing respectively its principle and its formalism, the experimental aspects of the method (spectrometers, samples) and two examples related to the materials for energy.

  13. Short-wave boundary of applicability of relief-phase reflecting holograms on a thin film of a chalcogenide glassy semiconductor

    NASA Astrophysics Data System (ADS)

    Koreshev, Sergey N.; Ratushnyi, Vladislav P.

    2013-03-01

    In the course of carrying out the present work, it was stated that a parasitic surface nano-structurization is peculiar to reflective relief-phase holograms obtained on thin layers of a chalcogenide glassy semiconductor (CGS). The results of experimental researches of the effect of a relief height for reflective relief-phase holograms on the parameters of their surface parasitic nano-structurization are presented in this paper. With the use of data obtained applying atomic force microscope (AFM) Solver P-47 and software complex "Nova", it was defined a short-wave boundary for applicability of such holograms. In addition to the conventional software complex "Nova", aiming at reducing time necessary for determination of a short-wave boundary for relief-phase hologram applicability, there was developed a software module, which operation is based on the determination of the averaged-out over a basic area (scanning area) relief profile shape of the hologram structure, the definition of root-mean-square roughness (RMSR) values of its surface averaged-out over the same basic area, and on the subsequent computation of the boundary wavelength for the hologram applicability. The determined short-wave boundary value came to 80nm. Starting from this value, the holograms with the relief height optimal from the view of maximal diffraction efficiency meet the Marechal's criterion ? <= ?/27 (? - rootmean- square roughness parameter) and the criterion of permitted light diffusion ? <= ?/100. Thus, the level of light diffusion and aberration permitted for precision optical systems is ensured in a reconstructed with their use image.

  14. Resolving radial composition gradients in polarized confocal raman spectra of individual 3C-SiC nanowires.

    PubMed

    Fréchette, Joëlle; Carraro, Carlo

    2006-11-22

    Silicon carbide nanowires are being actively pursued as components for nanoelectromechanical sensors, nanocatalytic elements, and nano-optical circuits able to operate in harsh environment, high temperature, and high power applications. The effect of geometric confinement and polarization anisotropy in confocal Raman spectroscopy has been employed to detect axial and radial composition information in individual nanowires. Polarization anisotropy causes a significant increase in signal from the surface layer (relative to bulk), and combined with the increased surface-to-volume ratio at the nanoscale, it allows for the direct characterization of bulk and surface defects. PMID:17105265

  15. FTIR external reflectance studies of lipid monolayers at the air-water interface: Applications to pulmonary surfactant

    NASA Astrophysics Data System (ADS)

    Wilkin, Jennifer M.; Dluhy, Richard A.

    1998-06-01

    FTIR external reflectance spectra of monomolecular films of natural products and model mixtures relevant to pulmonary surfactant physiology were collected concurrently with surface measurements directly at the air-water interface. Films studied were calf lung surfactant extract (CLSE) and its phospholipid fraction (PPL) along with 2:1 DPPC-d62:DPPG and 2:1 DPPC-d62:DOPG containing 0, 1 or 2 wt % of the hydrophobic surfactant proteins SP-B and SP-C (SP-B+C). The CH2 antisymmetric and symmetric stretching bands (~2920 and 2852 cm-1) along with the analogous CD2 stretching bands (~2194 and 2089 cm-1) were analyzed, and band heights, integrated intensities and peak frequency positions were plotted as a function of measured surface pressure. Data suggest that 2:1 DPPC-d62:DPPG+2 wt % SP-B+C is the most ordered and stable of the films and can be compressed to the highest sustainable surface pressure. Data from the model mixtures indicate that the surfactant protein interacts differently with each of the lipid components. Plots of the CH/CD intensity ratios versus surface pressure show an increase in this ratio upon the addition of SP-B+C as the protein apparently orders the CH component (DPPG or DOPG) and slightly disorders the CD component (DPPC-d62).

  16. Application of attenuated total reflectance Fourier transform infrared spectroscopy in the mineralogical study of a landslide area, Hungary

    NASA Astrophysics Data System (ADS)

    Udvardi, Beatrix; Kovács, István János; Kónya, Péter; Földvári, Mária; Füri, Judit; Budai, Ferenc; Falus, György; Fancsik, Tamás; Szabó, Csaba; Szalai, Zoltán; Mihály, Judith

    2014-11-01

    This study demonstrates that the unpolarized attenuated total reflectance Fourier transform infrared spectroscopy (ATR FTIR) is a practical and quick tool to distinguish different types of sediments in landslide-affected areas, and potentially other types of physical environments too. Identification and quantification of minerals by ATR FTIR is implemented on a set of powdered natural sediments from a loess landslide (Kulcs, Hungary). A protocol including sample preparation, analytical conditions and evaluation of sediment ATR spectra is outlined in order to identify and estimate major minerals in sediments. The comparison of the defined FTIR parameters against qualitative and quantitative results of X-ray diffraction and thermal analysis was used to validate the use of ATR FTIR spectroscopy for the considered sediments. The infrared band areas and their ratios (water/carbonates; silicates/carbonates; kaolinite) appear to be the most sensitive parameters to identify strongly weathered sediments such as paleosols and red clays which most likely facilitate sliding and could form sliding zones. The effect of grain size and orientation of anisotropic minerals on the wave number and intensity of some major absorption bands is also discussed.

  17. The statistical and fractal properties of surface reflectivity of raw chicken tissue with application to public health safety

    NASA Astrophysics Data System (ADS)

    Subramaniam, Raji; Sullivan, R.; Schneider, P. S.; Flamholz, A.; Cheung, E.; Tremberger, G., Jr.; Wong, P. K.; Lieberman, D. H.; Cheung, T. D.; Garcia, F.; Bewry, N.; Yee, A.

    2006-10-01

    Images of packaged raw chicken purchased in neighborhood supermarkets were captured via a digital camera in laboratory and home settings. Each image contained the surface reflectivity information of the chicken tissue. The camera's red, green and blue light signals fluctuated and each spectral signal exhibited a random series across the surface. The Higuchi method, where the length of each increment in time (or spatial) lag is plotted against the lag, was used to explore the fractal property of the random series. (Higuchi, T., "Approach to an irregular time series on the basis of fractal theory", Physica D, vol 31, 277-283, 1988). The fractal calculation algorithm was calibrated with the Weierstrass function. The standard deviation and fractal dimension were shown to correlate with the time duration that a package was left at room temperature within a 24-hour period. Comparison to packaged beef results suggested that the time dependence could be due microbial spoilage. The fractal dimension results in this study were consistent with those obtained from yeast cell, mammalian cell and bacterial cell studies. This analysis method can be used to detect the re-refrigeration of a "left-out" package of chicken. The extension to public health issues such as consumer shopping is also discussed.

  18. Synchrotron Infrared Confocal Microspectroscopical Detection of Heterogeneity Within Chemically Modified Single Starch Granules

    SciTech Connect

    Wetzel, D.; Shi, Y; Reffner, J

    2010-01-01

    This reports the first detection of chemical heterogeneity in octenyl succinic anhydride modified single starch granules using a Fourier transform infrared (FT-IR) microspectroscopical technique that combines diffraction-limited infrared microspectroscopy with a step size that is less than the mask projected spot size focused on the plane of the sample. The high spatial resolution was achieved with the combination of the application of a synchrotron infrared source and the confocal image plane masking system of the double-pass single-mask Continuum{reg_sign} infrared microscope. Starch from grains such as corn and wheat exists in granules. The size of the granules depends on the plant producing the starch. Granules used in this study typically had a median size of 15 {micro}m. In the production of modified starch, an acid anhydride typically is reacted with OH groups of the starch polymer. The resulting esterification adds the ester carbonyl (1723 cm{sup -1}) organic functional group to the polymer and the hydrocarbon chain of the ester contributes to the CH{sub 2} stretching vibration to enhance the intensity of the 2927 cm{sup -1} band. Detection of the relative modifying population on a single granule was accomplished by ratioing the baseline adjusted peak area of the carbonyl functional group to that of a carbohydrate band. By stepping a confocally defined infrared beam as small as 5 {micro}m x 5 {micro}m across a starch granule 1 {micro}m at a time in both the x and y directions, the heterogeneity is detected with the highest possible spatial resolution.

  19. Reflection Security Component for Java

    E-print Network

    Reflection Security Component for Java FIPS 140-2 Security Policy, version 1.21 29 November 2005.............................................................................................................27 #12;3 1 Module Overview Reflection Security Component for Java is a software component interfaces via a Java-based Application Programming Interface. Interface separation is provided and enforced

  20. Reflection Security Component for Java

    E-print Network

    Reflection Security Component for Java FIPS 140-2 Security Policy, version 1.21 29 July 2005 © WRQ.........................................................................................................25 #12;3 1 Module Overview Reflection Security Component for Java is a software component interfaces via a Java-based Application Programming Interface. Interface separation is provided and enforced

  1. LASER CONFOCAL MICROSCOPY AND GEOGRAPHIC INFORMATION SYSTEMS IN THE STUDY OF DENTAL MORPHOLOGY

    E-print Network

    Jernvall, Jukka

    LASER CONFOCAL MICROSCOPY AND GEOGRAPHIC INFORMATION SYSTEMS IN THE STUDY OF DENTAL MORPHOLOGY be transferred to geographic information systems (GIS) as well as interpreted by surface rendering computer parameters using geographic information systems (GIS). We then present a laser confocal microscopy technique

  2. In Situ Microspatial Imaging Using Two-Photon and Confocal Laser Scanning Microscopy of Bacteria and

    E-print Network

    Decho, Alan

    In Situ Microspatial Imaging Using Two-Photon and Confocal Laser Scanning Microscopy of Bacteria-LSM allowed very clear imaging with a high resolution of bacteria using DAPI, which normally require UV, with fluorescent probes, and subse- quent imaging using two-photon and confocal laser scanning microscopy (2P

  3. Characterization of Polymer Blends: Optical Microscopy (*Polarized, Interference and Phase Contrast Microscopy*) and Confocal Microscopy

    SciTech Connect

    Ramanathan, Nathan Muruganathan; Darling, Seth B.

    2015-01-01

    Chapter 15 surveys the characterization of macro, micro and meso morphologies of polymer blends by optical microscopy. Confocal Microscopy offers the ability to view the three dimensional morphology of polymer blends, popular in characterization of biological systems. Confocal microscopy uses point illumination and a spatial pinhole to eliminate out-of focus light in samples that are thicker than the focal plane.

  4. Journal of Neuroscience Methods 133 (2004) 153159 Confocal microscopic imaging of fast UV-laser

    E-print Network

    Segal, Menahem

    2004-01-01

    Journal of Neuroscience Methods 133 (2004) 153­159 Confocal microscopic imaging of fast UV-laser-dimensional cultured neurons. The laser light is introduced through the imaging optics, can be localized by a parallel; accepted 12 October 2003 Abstract Using a pulsed UV laser in a confocal scanning microscope, we present

  5. Unwarping confocal microscopy images of bee brains by nonrigid registration to a magnetic resonance

    E-print Network

    Menzel, Randolf - Institut für Biologie

    Unwarping confocal microscopy images of bee brains by nonrigid registration to a magnetic resonance microscopy image Torsten Rohlfing SRI International Neuroscience Program 333 Ravenswood Avenue Menlo Park Abstract. Confocal microscopy (CM) is a powerful image acquisition technique that is well established

  6. Design of an in-vivo multi-spectral confocal microendoscope for clinical trials

    E-print Network

    Gmitro, Arthur F.

    -intestinal tract and female reproductive system. More specifically, the system may have significant potential on the development and testing of a multi-spectral confocal microendoscope. Here we present a new system optical elements, and is structurally more robust. The slit-scanning confocal system employs two

  7. Using Photoshop with images created by a confocal system.

    PubMed

    Sedgewick, Jerry

    2014-01-01

    Many pure colors and grayscales tones that result from confocal imaging are not reproducible to output devices, such as printing presses, laptop projectors, and laser jet printers. Part of the difficulty in predicting the colors and tones that will reproduce lies in both the computer display, and in the display of unreproducible colors chosen for fluorophores. The use of a grayscale display for confocal channels and a LUT display to show saturated (clipped) tonal values aids visualization in the former instance and image integrity in the latter. Computer monitors used for post-processing in order to conform the image to the output device can be placed in darkened rooms, and the gamma for the display can be set to create darker shadow regions, and to control the display of color. These conditions aid in visualization of images so that blacks are set to grayer values that are more amenable to faithful reproduction. Preferences can be set in Photoshop for consistent display of colors, along with other settings to optimize use of memory. The Info window is opened so that tonal information can be shown via readouts. Images that are saved as indexed color are converted to grayscale or RGB Color, 16-bit is converted to 8-bit when desired, and colorized images from confocal software is returned to grayscale and re-colorized according to presented methods so that reproducible colors are made. Images may also be sharpened and noise may be reduced, or more than one image layered to show colocalization according to specific methods. Images are then converted to CMYK (Cyan, Magenta, Yellow and Black) for consequent assignment of pigment percentages for printing presses. Changes to single images and multiple images from image stacks are automated for efficient and consistent image processing changes. Some additional changes are done to those images destined for 3D visualization to better separate regions of interest from background. Files are returned to image stacks, saved and then printed to best reveal colors, contrast, details and features. PMID:24052348

  8. Haitian reflections.

    PubMed

    Docrat, Fathima

    2010-08-01

    Natural disasters and acts of terrorism demonstrate a similar critical need for national preparedness. As one of a team of volunteers with a local South African NGO who recently went on a medical mission, I would like to share glimpses of our experience and reflect on the mistakes - and also to state the obvious: that we do not learn from our mistakes. A simple literature search has shown that the same mistakes happen repeatedly. 'Humanitarian disasters occur with frightening regularity, yet international responses remain fragmented, with organizations and responders being forced to "reinvent the wheel" with every new event'. This is the result of an obvious lack of preparedness. PMID:20822625

  9. Dissolution dynamics of thin films measured by optical reflectance Christian Punckt and Ilhan A. Aksaya

    E-print Network

    Aksay, Ilhan A.

    Dissolution dynamics of thin films measured by optical reflectance Christian Punckt and Ilhan A and are intrinsically slow. We developed a characterization technique employing only an optical microscope, a digital in- terferometric microscopy IM ,21,22 or confocal scanning la- ser microscopy.23 All

  10. Reflectance near-infrared measurements for determining changes in skin barrier function and scattering in relation to moisturizer application

    NASA Astrophysics Data System (ADS)

    Qassem, Meha; Kyriacou, Panayiotis A.

    2015-09-01

    Skin moisture relates to the state of multiple skin constituents and aspects, but unfortunately, a device which could provide comprehensive and in vivo analysis is not available. Nevertheless, several reports have demonstrated accurate estimations of dermal water content using near-infrared spectroscopy (NIRS), and the potential of employing this technique in skin analysis. We aim to investigate whether NIRS could detect changes in skin barrier function through evaluation of skin water uptake in relation to moisturizer application. NIR and capacitance data were collected from 20 volunteers at both forearms, prior to and after seven days of regular moisturizer use. Results indicated lower peak intensities at the 1940-nm minima and higher intensities at the 1450-nm equivalent minima with moisturizer abstinence, while the opposite was true with regular moisturizer application. As the light beam would have traveled deeper into the skin at 1450 nm, it has been concluded that long-term, frequent moisturizer use had limited the penetration of extrinsic water. Partial least squares analysis showed that separation of sample's scores increased with abstinence of moisturizer use. Thus, NIRS can provide valuable information not only on dermal water contents but also on additional parameters such as skin barrier function.

  11. Spectral reflectance of carbonate minerals and rocks in the visible and near infrared (0.35 - 2.55 microns) and its applications in carbonate petrology

    NASA Technical Reports Server (NTRS)

    Gaffey, S. J.

    1984-01-01

    Reflection spectroscopy in the visible and near infrared (0.35 to 2.55 micron) offers a rapid, inexpensive, nondestructive tool for determining the mineralogy and investigating the minor element chemistry of the hard-to-discriminate carbonate minerals, and can, in one step, provide information previously obtainable only by the combined application of two or more analytical techniques. When light interacts with a mineral certain wavelengths are preferentially absorbed. The number, positions, widths and relative intensities of these absorptions are diagnostic of the mineralogy and chemical composition of the sample. At least seven bands due to vibrations of the carbonate radical occur between 1.60 and 2.55 micron. Positions of these bands vary from one carbonae mineral to another and can be used for mineral identification. Cation mass is the primary factor controlling band position; cation radius plays a secondary role.

  12. A line scanning confocal fluorescent microscope using a CMOS rolling shutter as an adjustable aperture.

    PubMed

    Mei, E; Fomitchov, P A; Graves, R; Campion, M

    2012-09-01

    Traditional confocal microscopy uses a physical aperture barrier to prevent out-of-focus light from reaching the detector. The physical nature of a conventional aperture limits control over the system confocality. We describe a new line scanning confocal microscope that eliminates a need for a physical aperture by employing a software-controllable rolling shutter on a CMOS camera. A confocal image is obtained by synchronizing motion of the rolling shutter and the laser line scanning over a sample. Confocal resolution of this microscope is adjustable in real time and independently established for each fluorescence channel by changing the rolling shutter width. This technology has been implemented in the IN Cell Analyzer 6000 system by GE Healthcare. PMID:22906014

  13. High-speed 3D shape measurement using a nonscanning multiple-beam confocal imaging system

    NASA Astrophysics Data System (ADS)

    Ishihara, Mitsuhiro; Sasaki, Hiromi

    1998-06-01

    This paper describes a high-speed 3D shape measurement system for in-line semiconductor package inspections. The system consists of three parts. One is an optics and sensor for confocal imaging, which we call a non-scanning multiple- beam confocal microscope. The microscope can get a confocal image within very short time because XY-scanning, which is required in conventional confocal microscopes, is not needed. Another is the algorithm that performs reconstructing the object surfaces accurately from a few confocal images. The last is a mechanism that performs shifting the focused plane of the microscope very quickly. This experimental system can measure objects having a space of 9.6 X 9.6 X 0.64 mm in less than 0.4 s with an accuracy in the order of 1 micrometers .

  14. High-speed surface measurement using a non-scanning multiple-beam confocal microscope

    NASA Astrophysics Data System (ADS)

    Ishihara, Mitsuhiro; Sasaki, Hiromi

    1999-06-01

    This paper describes a high-speed surface measurement system for in-line semiconductor package inspections. The system features the following three points in construction. One is an optics for confocal imaging. We call the optics a nonscanning multiple-beam confocal microscope. The microscope can get a confocal image in a short time because XY-scanning, which is required in conventional confocal microscopes, is not needed. Two is the algorithm that performs accurate reconstruction of the object surfaces from a few confocal images. The last is a mechanism that performs shifts of the focused plane of the microscope quickly. The experimental system can cover the measurement area of 9.6 X 9.6 X 0.64 mm and can measure that area in less than 0.4 s with an accuracy of about 1 micrometers .

  15. Combining multispectral polarized light imaging and confocal microscopy for localization of nonmelanoma skin cancer.

    PubMed

    Yaroslavsky, Anna N; Barbosa, Jose; Neel, Victor; DiMarzio, Charles; Anderson, R Rox

    2005-01-01

    Multispectral polarized light imaging (MSPLI) enables rapid inspection of a superficial tissue layer over large surfaces, but does not provide information on cellular microstructure. Confocal microscopy (CM) allows imaging within turbid media with resolution comparable to that of histology, but suffers from a small field of view. In practice, pathologists use microscopes at low and high power to view tumor margins and cell features, respectively. Therefore, we study the combination of CM and MSPLI for demarcation of nonmelanoma skin cancers. Freshly excised thick skin samples with nonmelanoma cancers are rapidly stained with either toluidine or methylene blue dyes, rinsed in acetic acid, and imaged using MSPLI and CM. MSPLI is performed at 630, 660, and 750 nm. The same specimens are imaged by reflectance CM at 630, 660, and 830 nm. Results indicate that CM and MSPLI images are in good correlation with histopathology. Cytological features are identified by CM, and tumor margins are delineated by MSPLI. A combination of MSPLI and CM appears to be complementary. This combined in situ technique has potential to guide cancer surgery more rapidly and at lower cost than conventional histopathology. PMID:15847592

  16. In vivo confocal microscopy of basal cell carcinoma: a systematic review of diagnostic accuracy.

    PubMed

    Kadouch, D J; Schram, M E; Leeflang, M M; Limpens, J; Spuls, P I; de Rie, M A

    2015-10-01

    Basal cell carcinoma (BCC) is the most prevalent type of skin cancer. Histologic analysis of punch biopsy or direct excision specimen is used to confirm clinical diagnosis. In vivo reflectance confocal microscopy (RCM) is a non-invasive imaging modality that could facilitate early diagnosis and minimize unnecessary invasive procedures. We systematically reviewed diagnostic accuracy (sensitivity and specificity) of RCM in diagnosing primary BCCs to judge its usefulness. Eligible studies were reviewed for methodological quality using the QUADAS-2 tool. We used the bivariate random-effects model to calculate summary estimates of sensitivity and specificity. Six studies met the selection criteria and were included for analysis. The meta-analysis showed a summary estimate of sensitivity 0.97 (95% CI, 0.90-0.99) and specificity 0.93 (95% CI, 0.88-0.96). All but one of the QUADAS-2 items showed a high or unclear risk of bias with regards to patient selection. RCM may be a promising diagnostic tool, but the limited number of available studies and potential risk of bias of included studies do not allow us to draw firm conclusions. Future accuracy studies should take these limitations into account. PMID:26290493

  17. Application of VNIR diffuse reflectance spectroscopy for mapping of organic matter redistribution due to erosion and deposition processes

    NASA Astrophysics Data System (ADS)

    Klement, Ales; Brodsky, Lukas; Jaksik, Ondrej; Fer, Miroslav; Kodesova, Radka

    2014-05-01

    Visible and near-infrared (VNIR) diffuse reflectance spectroscopy is cost- and time-effective and environmentally friendly techniques method used for prediction of soil properties. Study was performed on the soils from the agricultural land from the municipalities of Brumovice (209 samples), Sedlcany (67 samples), Vidim (74 samples) and Zelezna (32 samples). In Brumovice original soil type was Haplic Chernozem on loess, which was due to erosion changed into Regosol (steep parts) and Colluvial soil (base slope and the tributary valley). A similar process has been described at other three locations Sedlcany, Vidim and Zelezna where the original soil types were Haplic Cambisol on gneiss, Haplic Luvisol on loess and Haplic Cambisol on shales, respectively. The goal of the study was to evaluate relationship between soil spectra curves and organic matter content to provide an efficient tool for mapping of organic matter redistribution (i.e. soil degradation) due to erosion and deposition processes. Samples were taken from the topsoil within regular grid covering studied areas. The soil spectra curves (of air dry soil and sieved using 0.2 mm sieve) were measured in the laboratory using spectrometer FieldSpec®3 (350 - 2 500 nm). Partial least squares regression (PLSR) was used for modeling of the relationship between spectra and measured organic matter content. Prediction ability was evaluated using the R2, root mean square error (RMSE). The results showed the best prediction of the organic matter content was obtained for soil samples from Brumovice (R2 = 0.78, RMSE = 0.15) and decreased as follows: Zelezna (R2 = 0.68, RMSE = 0.23), Sedlcany (R2 = 0.64, RMSE = 0.18) and Vidim (R2 = 0.61, RMSE = 0.12). In general, the results confirmed that the measurement of soil spectral characteristics is a promising technology for a digital soil mapping and predicting studied soil properties. Acknowledgment: Authors acknowledge the financial support of the Ministry of Agriculture of the Czech Republic (grant No. QJ1230319).

  18. Laser confocal feedback tomography and nano-step height measurement

    PubMed Central

    Tan, Yidong; Wang, Weiping; Xu, Chunxin; Zhang, Shulian

    2013-01-01

    A promising method for tomography and step height measurement is proposed, which combines the high sensitivity of the frequency-shifted feedback laser and the axial positioning ability of confocal microscopy. By demodulating the feedback-induced intensity modulation signals, the obtained amplitude and phase information are used to respectively determine the coarse and fine measurement of the samples. Imaging the micro devices and biological samples by the demodulated amplitude, this approach is proved to be able to achieve the cross-sectional image in highly scattered mediums. And then the successful height measurement of nano-step on a glass-substrate grating by combination of both amplitude and phase information indicates its axial high resolution (better than 2?nm) in a non-ambiguous range of about ten microns. PMID:24145717

  19. Spatial resolution of confocal XRF technique using capillary optics.

    PubMed

    Dehlinger, Maël; Fauquet, Carole; Lavandier, Sebastien; Aumporn, Orawan; Jandard, Franck; Arkadiev, Vladimir; Bjeoumikhov, Aniouar; Tonneau, Didier

    2013-01-01

    XRF (X-ray fluorescence) is a powerful technique for elemental analysis with a high sensitivity. The resolution is presently limited by the size of the primary excitation X-ray beam. A test-bed for confocal-type XRF has been developed to estimate the ultimate lateral resolution which could be reached in chemical mapping using this technique. A polycapillary lens is used to tightly focus the primary X-ray beam of a low power rhodium X-ray source, while the fluorescence signal is collected by a SDD detector through a cylindrical monocapillary. This system was used to characterize the geometry of the fluorescent zone. Capillary radii ranging from 50 ?m down to 5 ?m were used to investigate the fluorescence signal maximum level This study allows to estimate the ultimate resolution which could be reached in-lab or on a synchrotron beamline. A new tool combining local XRF and scanning probe microscopy is finally proposed. PMID:23758858

  20. Spatial resolution of confocal XRF technique using capillary optics

    PubMed Central

    2013-01-01

    XRF (X-ray fluorescence) is a powerful technique for elemental analysis with a high sensitivity. The resolution is presently limited by the size of the primary excitation X-ray beam. A test-bed for confocal-type XRF has been developed to estimate the ultimate lateral resolution which could be reached in chemical mapping using this technique. A polycapillary lens is used to tightly focus the primary X-ray beam of a low power rhodium X-ray source, while the fluorescence signal is collected by a SDD detector through a cylindrical monocapillary. This system was used to characterize the geometry of the fluorescent zone. Capillary radii ranging from 50 ?m down to 5 ?m were used to investigate the fluorescence signal maximum level This study allows to estimate the ultimate resolution which could be reached in-lab or on a synchrotron beamline. A new tool combining local XRF and scanning probe microscopy is finally proposed. PMID:23758858

  1. Temperature influence in confocal techniques for a silicon wafer testing

    NASA Astrophysics Data System (ADS)

    Litwin, D.; Galas, J.; Sitarek, S.; Surma, B.; Piatkowski, B.; Miros, A.

    2007-05-01

    The paper discusses problems of Silicon wafer measurements accuracy in context of the scanning helium atom microscope, which is a new technique currently under development. In the microscope the helium atom beam is used as a probe. The overall microscope resolution depends on a deflecting element, which shapes the beam and focuses it onto a sample's surface. The most promising focusing component appears to be an ultra thin silicon wafer that is deformed under a precise electric field. Thus its quality is decisive for the project success. Flatness and thickness uniformity of the wafer must be measured in order to select the best plate to be used in the microscope. A scanning measurement system consists of two coaxially positioned confocal heads. Recent studies have revealed that the system is very sensitive to temperature variation. The compensation algorithms and further measures designed to suppress the temperature effect are presented and discussed.

  2. Interferometric and confocal techniques for testing of silicon wafers

    NASA Astrophysics Data System (ADS)

    Galas, J.; Litwin, D.; Sitarek, S.; Surma, B.; Piatkowski, B.; Miros, A.

    2006-04-01

    The paper provides new insights into Silicon wafer measurements in context of technological problems of developing a sophisticated measurement technique, which harnesses helium atom beam as a probe. Nano-resolution imaging techniques such as scanning tunnelling microscopy (STM) and atomic force microscopy (AFM) are well-know in surface science. A scanning helium atom microscope, where a focused beam of low energy, neutral helium atoms is used as an imaging probe is a new concept creating non-destructive and non-invasive surface investigation tool in science and industry. This paper is focused on measurements of flatness and thickness of the wafer, which is used as a deflecting mirror of the helium beam. Two -optics based- measurement techniques are presented: scanning confocal system and the Fizeau interferometer. The latter is applied as a quick reference device placed close to the production line whereas the former offers high accuracy flatness and thickness maps of the wafers.

  3. The free-electron laser in a symmetrical confocal resonator

    NASA Technical Reports Server (NTRS)

    Ozcan, Meric; Pantell, Richard H.

    1993-01-01

    A tapered wiggler is used in a FEL oscillator to improve the saturation efficiency. During signal buildup the tapered wiggler does not provide optimum phase synchronism between the electron beam and the electromagnetic wave, resulting in an appreciable loss in small-signal gain. This problem can be ameliorated by using a multicomponent wiggler, which is a combination of a uniform wiggler and a tapered section. During buildup, gain is primarily contributed by the linear element, and at high power levels the gain and efficiency are enhanced by the taper. Ideally, one would like to have the optical waist location near the linear section at small-signal levels and at near the tapered section at high power levels. Placing the FEL in a symmetrical confocal resonator approaches this desired effect automatically since it has the unique characteristic that a stable mode exists for all locations of the waist of a Gaussian beam along the axis of the interferometer.

  4. Partially Reflected Diffusion

    E-print Network

    A. Singer; Z. Schuss; D. Holcman

    2007-09-02

    The radiation (reaction, Robin) boundary condition for the continuum diffusion equation is widely used in chemical and biological applications to express reactive boundaries. The underlying trajectories of the diffusing particles are believed to be partially absorbed and partially reflected at the reactive boundary, however, the relation between the reaction (radiation) constant in the Robin boundary condition and the reflection probability is still unclear. In this paper we clarify the issue by finding the relation between the reaction (radiation) constant and the absorption probability of the diffusing trajectories at the boundary. We analyze the Euler scheme for the underlying It\\^o dynamics, which is assumed to have variable drift and diffusion tensor, with partial reflection at the boundary. Trajectories that cross the boundary are terminated with a given probability and otherwise are reflected in a normal or oblique direction. We use boundary layer analysis of the corresponding Wiener path integral to resolve the non-uniform convergence of the probability density function of the numerical scheme to the solution of the Fokker-Planck equation with the Robin boundary condition, as the time step is decreased. We show that the Robin boundary condition is recovered in the limit iff trajectories are reflected in the co-normal direction. We find the relation of the reactive constant to the termination probability. We show the effect of using the new relation in numerical simulations.

  5. Visible and Mid-Infrared Supercontinuum Generation and Their Respective Application to Three-Dimensional Imaging and Stand-off Reflection Spectroscopy

    NASA Astrophysics Data System (ADS)

    Kumar, Malay

    The thesis describes broadband supercontinuum (SC) generation in optical fibers for both the visible and mid-infrared regions of the spectrum, and their respective application to 3D imaging and stand-off reflection spectroscopy. Both SC sources leverage mature telecom technology, and are based on a common all-fiber integrated platform comprising a ˜1.55 mum distributed feedback seed laser diode amplified to high peak powers in two stages of cladding pumped Erbium or Erbium-Ytterbium fiber amplifiers. A visible SC extending from 0.45--1.20 mum with 0.74 W of time-averaged power is demonstrated using a two step process. The output of the Er-Yb power amplifier is frequency doubled to ˜0.78 mum using a periodically poled lithium niobate crystal, followed by non-linear spectral broadening in 2m of high nonlinearity photonic crystal fiber. Numerical simulations based on solving the generalized non-linear Schrodinger equation are also presented to verify the underlying SC generation mechanisms and predict further improvements. The above SC source is used in a Fourier domain line scan interferometer to measure the height and identify shape defects of ˜300 mum high solder balls in a ball grid array. The 3D imaging system has an axial resolution of ˜125 nm, transverse resolution of ˜15 mum, and an angular measurement range between 20 to 60 degrees depending on the sample surface roughness. The mid-infrared SC source is generated by pumping a 9m long ZrE 4-BaF2-LaF3-AlF3-NaF (ZBLAN) fiber to obtain a spectrum spanning 0.8--4.3 mum with 3.9 W time-averaged power. The output power is linearly scalable with pump power, but requires optimization of the critical splices and thermal management of the gain fiber and pump diodes to ensure stable high power operation. Finally, an application of the mid-IR SC is demonstrated by measuring the diffuse reflection spectra of solid samples at a stand-off distance of 5 m and 100 ms integration time. The samples can be distinguished using a correlation algorithm based on distinct spectral features in the reflection spectrum. Signal to noise ratio calculations show that the distance is limited by space constraints in our lab and can be extended to ˜150 m.

  6. In vivo confocal microscopic characteristics of crystalline keratopathy in patients with monoclonal gammopathy: report of two cases.

    PubMed

    Kocabeyoglu, Sibel; Mocan, Mehmet C; Haznedaroglu, Ibrahim C; Uner, Aysegul; Uzunosmanoglu, Enes; Irkec, Murat

    2014-09-01

    In this paper, we report two cases of a 62-year-old patient presented with blurred vision and a 45-year-old male diagnosed with multiple myeloma who was referred from the Department of Oncology. Slit-lamp examination, in vivo confocal microscopy (IVCM), systemic work-up and serum protein electrophoresis were obtained. In both patients, slit-lamp findings revealed bilateral diffuse subepithelial and anterior stromal crystals and IVCM showed highly reflective deposits in the corneal epithelium and stroma. The first patient was eventually diagnosed with monoclonal gammopathy of undetermined significance following bone marrow biopsy and systemic evaluation. Unusual corneal deposits may constitute the first sign of monoclonal gammopathies. IVCM may be helpful in showing the crystalline nature of the corneal deposits and guiding the clinician to the diagnosis of gammopathies. Both ophthalmologists and oncologists should be aware that corneal deposits may herald a life-threatening hematologic disease. PMID:25370397

  7. PbS nanosculptured thin film for phase retarder, anti-reflective, excellent absorber, polarizer and sensor applications.

    PubMed

    Chaudhary, Ashok; Klebanov, Matvey; Abdulhalim, Ibrahim

    2015-11-20

    Lead-sulphide (PbS) nanosculptured thin film (nSTF) is prepared using a glancing angle deposition (GLAD) technique and the physical vapour deposition (PVD) process. The morphology of the GLAD films clearly shows that an anisotropic structure is obtained and is composed of micro-sheets with sharp top edges (a few tens of nanometres tip width). Due to this anisotropy, optical birefringence is induced in the nSTF as well as linear dichroism. The structural and optical properties of the PbS nSTF have been characterized by scanning electron microscopy, atomic force microscopy, Raman spectroscopy and transmission measurements. The Raman spectra of PbS nSTF exhibit sharp peaks representative of vibrations in nano-crystalline PbS. Due to the absorption of PbS the nSTF is found to act as a linear polarizer with good extinction and contrast in the near infra-red range. Due to its porosity this nSTF also has the ability to sense fluids, which we demonstrate using ethanol-water solution at different concentrations. The combination of these effects in PbS nSTF is believed to constitute a prime candidate for many desirable device applications in different aspects with the low cost of production in large areas. PMID:26502208

  8. PbS nanosculptured thin film for phase retarder, anti-reflective, excellent absorber, polarizer and sensor applications

    NASA Astrophysics Data System (ADS)

    Chaudhary, Ashok; Klebanov, Matvey; Abdulhalim, Ibrahim

    2015-11-01

    Lead-sulphide (PbS) nanosculptured thin film (nSTF) is prepared using a glancing angle deposition (GLAD) technique and the physical vapour deposition (PVD) process. The morphology of the GLAD films clearly shows that an anisotropic structure is obtained and is composed of micro-sheets with sharp top edges (a few tens of nanometres tip width). Due to this anisotropy, optical birefringence is induced in the nSTF as well as linear dichroism. The structural and optical properties of the PbS nSTF have been characterized by scanning electron microscopy, atomic force microscopy, Raman spectroscopy and transmission measurements. The Raman spectra of PbS nSTF exhibit sharp peaks representative of vibrations in nano-crystalline PbS. Due to the absorption of PbS the nSTF is found to act as a linear polarizer with good extinction and contrast in the near infra-red range. Due to its porosity this nSTF also has the ability to sense fluids, which we demonstrate using ethanol–water solution at different concentrations. The combination of these effects in PbS nSTF is believed to constitute a prime candidate for many desirable device applications in different aspects with the low cost of production in large areas.

  9. Reflective Insulation

    NASA Technical Reports Server (NTRS)

    1992-01-01

    NRC-2 Superinsulation, manufactured by Metallized Products, Inc. (MPI), is designed for superconducting magnets used in MRI systems and particle accelerators. It is a thin, polyester film characterized by a unique crinkled surface that provides surface stand-off between layers and minimizes heat transfer in multilayer applications. NRC-2/Two is a two-sided metallized film. The material, originally developed as a skin for balloon-like satellites, was later used by NASA as a thermal barrier. MPI worked with NASA on the development of the original material and now supplies it for both space and consumer applications.

  10. Reflected Glory

    NASA Astrophysics Data System (ADS)

    2011-02-01

    The nebula Messier 78 takes centre stage in this image taken with the Wide Field Imager on the MPG/ESO 2.2-metre telescope at the La Silla Observatory in Chile, while the stars powering the bright display take a backseat. The brilliant starlight ricochets off dust particles in the nebula, illuminating it with scattered blue light. Igor Chekalin was the overall winner of ESO's Hidden Treasures 2010 astrophotography competition with his image of this stunning object. Messier 78 is a fine example of a reflection nebula. The ultraviolet radiation from the stars that illuminate it is not intense enough to ionise the gas to make it glow - its dust particles simply reflect the starlight that falls on them. Despite this, Messier 78 can easily be observed with a small telescope, being one of the brightest reflection nebulae in the sky. It lies about 1350 light-years away in the constellation of Orion (The Hunter) and can be found northeast of the easternmost star of Orion's belt. This new image of Messier 78 from the MPG/ESO 2.2-metre telescope at the La Silla Observatory is based on data selected by Igor Chekalin in his winning entry to the Hidden Treasures competition [1]. The pale blue tint seen in the nebula in this picture is an accurate representation of its dominant colour. Blue hues are commonly seen in reflection nebulae because of the way the starlight is scattered by the tiny dust particles that they contain: the shorter wavelength of blue light is scattered more efficiently than the longer wavelength red light. This image contains many other striking features apart from the glowing nebula. A thick band of obscuring dust stretches across the image from the upper left to the lower right, blocking the light from background stars. In the bottom right corner, many curious pink structures are also visible, which are created by jets of material being ejected from stars that have recently formed and are still buried deep in dust clouds. Two bright stars, HD 38563A and HD 38563B, are the main powerhouses behind Messier 78. However, the nebula is home to many more stars, including a collection of about 45 low mass, young stars (less than 10 million years old) in which the cores are still too cool for hydrogen fusion to start, known as T Tauri stars. Studying T Tauri stars is important for understanding the early stages of star formation and how planetary systems are created. Remarkably, this complex of nebulae has also changed significantly in the last ten years. In February 2004 the experienced amateur observer Jay McNeil took an image of this region with a 75 mm telescope and was surprised to see a bright nebula - the prominent fan shaped feature near the bottom of this picture - where nothing was seen on most earlier images. This object is now known as McNeil's Nebula and it appears to be a highly variable reflection nebula around a young star. This colour picture was created from many monochrome exposures taken through blue, yellow/green and red filters, supplemented by exposures through an H-alpha filter that shows light from glowing hydrogen gas. The total exposure times were 9, 9, 17.5 and 15.5 minutes per filter, respectively. Notes [1] Igor Chekalin from Russia uncovered the raw data for this image of Messier 78 in ESO's archives in the competition Hidden Treasures (eso1102). He processed the raw data with great skill, claiming first prize in the contest for his final image (Flickr link). ESO's team of in-house image processing experts then independently processed the raw data at full resolution to produce the image shown here. More information ESO, the European Southern Observatory, is the foremost intergovernmental astronomy organisation in Europe and the world's most productive astronomical observatory. It is supported by 15 countries: Austria, Belgium, Brazil, the Czech Republic, Denmark, France, Finland, Germany, Italy, the Netherlands, Portugal, Spain, Sweden, Switzerland and the United Kingdom. ESO carries out an ambitious programme focused on the design, construction and operation of powerful ground-based obser

  11. Can the caged bird sing? Reflections on the application of qualitative research methods to case study design in homeopathic medicine

    PubMed Central

    Thompson, Trevor DB

    2004-01-01

    Background Two main pathways exist for the development of knowledge in clinical homeopathy. These comprise clinical trials conducted primarily by university-based researchers and cases reports and homeopathic "provings" compiled by engaged homeopathic practitioners. In this paper the relative merits of these methods are examined and a middle way proposed. This consists of the "Formal Case Study" (FCS) in which qualitative methods are used to increase the rigour and sophistication with which homeopathic cases are studied. Before going into design issues this paper places the FCS in an historical and academic context and describes the relative merits of the method. Discussion Like any research, the FCS should have a clear focus. This focus can be both "internal", grounded in the discourse of homeopathy and also encompass issues of wider appeal. A selection of possible "internal" and "external" research questions is introduced. Data generation should be from multiple sources to ensure adequate triangulation. This could include the recording and transcription of actual consultations. Analysis is built around existing theory, involves cross-case comparison and the search for deviant cases. The trustworthiness of conclusions is ensured by the application of concepts from qualitative research including triangulation, groundedness, respondent validation and reflexivity. Though homeopathic case studies have been reported in mainstream literature, none has used formal qualitative methods – though some such studies are in progress. Summary This paper introduces the reader to a new strategy for homeopathic research. This strategy, termed the "formal case study", allows for a naturalistic enquiry into the players, processes and outcomes of homeopathic practice. Using ideas from qualitative research, it allows a rigorous approach to types of research question that cannot typically be addressed through clinical trials and numeric outcome studies. The FCS provides an opportunity for the practitioner-researcher to contribute to the evidence-base in homeopathy in a systematic fashion. The FCS can also be used to inform the design of clinical trials through holistic study of the "active ingredients" of the therapeutic process and its clinical outcomes. PMID:15018637

  12. arXiv:math.RT/0502035v228Jul2005 REFLECTION FUNCTORS AND SYMPLECTIC REFLECTION

    E-print Network

    Gan, Wee Liang

    arXiv:math.RT/0502035v228Jul2005 REFLECTION FUNCTORS AND SYMPLECTIC REFLECTION ALGEBRAS FOR WREATH PRODUCTS WEE LIANG GAN Abstract. We construct reflection functors on categories of modules over deformed applications to the representation theory of symplectic reflection algebras of wreath product groups. 1

  13. Application of the NEES T-Rex Vibrator for 3-component Crustal Reflection/Refraction Profiling: 2004 Test in the Basin and Range

    NASA Astrophysics Data System (ADS)

    Lerch, D. W.; Klemperer, S. L.; Stokoe, K. H.; Menq, F.

    2005-12-01

    In September 2004, Stanford University and UT Austin collected crustal reflection/refraction data with the Network for Earthquake Engineering Simulation (NEES) tri-axial (T-Rex) vibrator in two separate surveys: (1) a 40 km crustal-scale profile in the Black Rock Desert and Black Rock Range, NV; and (2) a 16 km `high-resolution' basin imaging profile in Surprise Valley, CA. Both experiments were completed in the northwestern Basin and Range transition zone as part of a larger, 300 km wide-angle refraction line, recorded by an IRIS-PASSCAL transportable array. Our broad goals were to test the feasibility of the T-Rex in crustal-scale applications with existing IRIS-PASSCAL equipment, and to augment our refraction data with structural information. T-Rex, acquired by NEES-UT Austin in 2002, is a 64,000 lb buggy-mounted vibrator with a tri-axial mass, producing P, SV, and SH waves. In order to balance desired upper-crustal resolution with an attempt to record mid-crustal reflectivity and shear-wave data during the crustal-scale profiling, T-Rex swept at 300 m intervals for 5 minutes (1 min. P, 2 min. SV, 2 min. SH), and at 3 km intervals for 50 minutes (10 min. P, 20 min. SV, 20 min. SH). This source configuration afforded coverage of a relatively wide aperture in a modest amount of field time, while stacked sweeps recorded at 3 km intervals provided greater source effort than individual vibration points for the 1983 COCORP 40ON Nevada deep reflection profile which recorded strong Moho reflections. Crustal data were continuously recorded in four-hour windows at 125 sps on a combination of vertical (RefTek Texan) and 3-component (RefTek RT130) instruments forming a 40 km array spaced at 100 m, embedded within the larger wide-angle profile. The `hi-res' survey (250 sps, 40 m receiver spacing, 10 m source spacing) imaged the active Surprise Valley basin to constrain basin depth, fault geometry, and basin-fill P- and S-wave velocities. Our source effort (single 1 min. sweeps) is comparable with prior successful efforts to image upper-crustal basement structure (e.g., Virginia Tech's 1981 Atlantic Coastal Plain survey). Despite attenuation and poor coupling in the unconsolidated basin fill (Vp ~ 1.8 km/s) of Surprise Valley and the Black Rock Desert, coherent refracted energy on raw, single-sweep gathers is visible to 9 km offset, with reflections visible to ~ 3 sec (twtt). Our data indicate the NEES T-Rex vibrator is a viable source for upper crustal P- and S-wave surveys, and may produce useful mid-crustal data under favorable conditions.

  14. Three-dimensional analysis of complex branching vessels in confocal microscopy images.

    PubMed

    Maddah, Mahnaz; Soltanian-Zadeh, Hamid; Afzali-Kusha, Ali; Shahrokni, Ali; Zhang, Zheng G

    2005-09-01

    The characteristic of confocal microscopy (CM) vascular data is that it contains many tiny vessels with branching and complex structure. In this work, an automated method for quantitative analysis and reconstruction of cerebral vessels from CM images is presented in which the extracted centerline of the vessels plays the key role. To assess the efficiency and accuracy of different centerline extraction methods, a comparison among three fully automated approaches is given. The centerline extraction methods studied in this work are a snake model, a path planning approach, and a distance transform-based method. To evaluate the accuracy of the quantitative parameters of vessels such as length and diameter, we apply the method to synthetic data. These results indicate that the snake model and the path planning method are more accurate in extracting the quantitative parameters. The efficiency of the approach in clinical applications is then confirmed by applying the method to real CM images. All three methods investigated in this work are accurate enough to correctly distinguish between normal and stroke brain data, while the snake model is the fastest for clinical applications. In addition, three-dimensional visualization, reconstruction, and characterization of CM vascular images of rat brains are presented. PMID:15996853

  15. Confocal operation of a transmission electron microscope with two aberration correctors

    NASA Astrophysics Data System (ADS)

    Nellist, P. D.; Behan, G.; Kirkland, A. I.; Hetherington, C. J. D.

    2006-09-01

    The authors demonstrate that confocal imaging trajectories can be established in a transmission electron microscope fitted with two spherical aberration correctors. An atomic-scale electron beam, focused by aberration-corrected illumination optics, is directly imaged by a second aberration-corrected system. The initial experiment described indicates how aberration-corrected scanning confocal electron microscopy will allow three-dimensional imaging and analysis of materials with atomic lateral resolution and with a depth resolution of a few nanometers. The depth resolution in the confocal mode is shown to be robust to the uncorrected chromatic aberration of the lenses, unlike depth sectioning using a single lens.

  16. Confocal imaging at the nanoscale with two-color STED microscopy

    NASA Astrophysics Data System (ADS)

    Gugel, Hilmar; Giske, Arnold; Dyba, Marcus; Sieber, Jochen

    2011-03-01

    STED microscopy enables confocal imaging of biological samples with a resolution that is not limited by diffraction. It provides new insights in various fields of biology, such as membrane biology, neurobiology and physiology. Its three dimensional sectioning ability allows the acquisition of high resolution image stacks. Furthermore, STED microscopy enables the recording of dynamic processes and live cell images. We present two-color imaging in confocal STED microscopy with a single STED wavelength. Pulsed and continuous wave lasers in the visible and near infra-red wavelengths range are used for stimulated emission. The resolution enhancement is demonstrated in comparison to confocal imaging with biological specimens.

  17. A Reflective Look at Reflecting Teams

    ERIC Educational Resources Information Center

    Pender, Rebecca L.; Stinchfield, Tracy

    2012-01-01

    This article reviewed existing literature and research on the reflecting team process. There is a dearth of empirical research that explores the reflecting team process and the outcome of counseling that uses reflecting teams. Implications of using reflecting teams for counselors, counselor educators, and clients will be discussed. A call for…

  18. Protocol for Three-dimensional Confocal Morphometric Analysis of Astrocytes.

    PubMed

    Bagheri, Maryam; Rezakhani, Arjang; Roghani, Mehrdad; Joghataei, Mohammad T; Mohseni, Simin

    2015-01-01

    As glial cells in the brain, astrocytes have diverse functional roles in the central nervous system. In the presence of harmful stimuli, astrocytes modify their functional and structural properties, a condition called reactive astrogliosis. Here, a protocol for assessment of the morphological properties of astrocytes is presented. This protocol includes quantification of 12 different parameters i.e. the surface area and volume of the tissue covered by an astrocyte (astrocyte territory), the entire astrocyte including branches, cell body, and nucleus, as well as total length and number of branches, the intensity of fluorescence immunoreactivity of antibodies used for astrocyte detection, and astrocyte density (number/1,000 µm(2)). For this purpose three-dimensional (3D) confocal microscopic images were created, and 3D image analysis software such as Volocity 6.3 was used for measurements. Rat brain tissue exposed to amyloid beta1-40 (A?1-40) with or without a therapeutic intervention was used to present the method. This protocol can also be used for 3D morphometric analysis of other cells from either in vivo or in vitro conditions. PMID:26709729

  19. A generalized Potts model for confocal microscopy images

    NASA Astrophysics Data System (ADS)

    Máté, Gabriell; Heermann, Dieter W.

    2015-01-01

    Much as being among the least invasive mainstream imaging technologies in life sciences, the resolution of confocal microscopy is limited. Imaged structures, e.g., chromatin-fiber loops, have diameters around or beyond the diffraction limit, and microscopy images show seemingly random spatial density distributions only. While such images are important because the organization of the chromosomes influences different cell mechanisms, many interesting questions can also be related to the observed patterns. These concern their spatial aspects, the role of randomness, the possibility of modeling these images with a random generative process, the interaction between the densities of adjacent loci, the length-scales of these influences, etc. We answer these questions by implementing a generalization of the Potts model. We show how to estimate the model parameters, test the performance of the estimation process and numerically prove that the obtained values converge to the ground truth. Finally, we generate images with a trained model and show that they compare well to real cell images.

  20. Automatic analysis for neuron by confocal laser scanning microscope

    NASA Astrophysics Data System (ADS)

    Satou, Kouhei; Aoki, Yoshimitsu; Mataga, Nobuko; Hensh, Takao K.; Taki, Katuhiko

    2005-12-01

    The aim of this study is to develop a system that recognizes both the macro- and microscopic configurations of nerve cells and automatically performs the necessary 3-D measurements and functional classification of spines. The acquisition of 3-D images of cranial nerves has been enabled by the use of a confocal laser scanning microscope, although the highly accurate 3-D measurements of the microscopic structures of cranial nerves and their classification based on their configurations have not yet been accomplished. In this study, in order to obtain highly accurate measurements of the microscopic structures of cranial nerves, existing positions of spines were predicted by the 2-D image processing of tomographic images. Next, based on the positions that were predicted on the 2-D images, the positions and configurations of the spines were determined more accurately by 3-D image processing of the volume data. We report the successful construction of an automatic analysis system that uses a coarse-to-fine technique to analyze the microscopic structures of cranial nerves with high speed and accuracy by combining 2-D and 3-D image analyses.