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1

Volume reflection holographic confocal imaging.  

PubMed

The Denisyuk volume reflection hologram is produced with spatially incoherent light to form an image-plane hologram. The image formed in readout combines the properties of volume holography and confocal image formation. PMID:18349989

Yang, G G; Chen, H S; Leith, E N

2000-08-10

2

Reflectance confocal microscopy of optical phantoms  

PubMed Central

A reflectance confocal scanning laser microscope (rCSLM) operating at 488-nm wavelength imaged three types of optical phantoms: (1) 100-nm-dia. polystyrene microspheres in gel at 2% volume fraction, (2) solid polyurethane phantoms (INO BiomimicTM), and (3) common reflectance standards (SpectralonTM). The noninvasive method measured the exponential decay of reflected signal as the focus (zf) moved deeper into the material. The two experimental values, the attenuation coefficient ? and the pre-exponential factor ?, were mapped into the material optical scattering properties, the scattering coefficient ?s and the anisotropy of scattering g. Results show that ?s varies as 58, 8–24, and 130–200 cm-1 for phantom types (1), (2) and (3), respectively. The g varies as 0.112, 0.53–0.67, and 0.003–0.26, respectively.

Jacques, Steven L.; Wang, Bo; Samatham, Ravikant

2012-01-01

3

Reflectance confocal microscopy in the daily practice.  

PubMed

Reflectance confocal microscopy (RCM) allows noninvasive imaging of the epidermis and superficial dermis. Like dermoscopy, RCM acquires images in the horizontal plane (en face), allowing assessment of tissue pathology underlying dermoscopic structures of interest at a cellular-level resolution. Thus, clinicians using dermoscopy may find RCM to be particularly useful. Our aim was to show the value of RCM for diagnosis and management decisions related to pigmented and nonpigmented skin neoplasms seen in daily practice. Six cases of clinically and dermoscopically equivocal skin lesions, for which RCM facilitated making the correct diagnosis, are presented. Final diagnoses were made based on histopathologic analysis. Three flat pigmented skin lesions with dermoscopic signs of regression showed distinct RCM features that allowed their correct classification as pigmented basal cell carcinoma, pigmented actinic keratosis, and melanoma on sun-damaged skin. A flat nonpigmented skin lesion on the face, which did not show distinct clinical or dermoscopic features, was correctly diagnosed as basal cell carcinoma based on RCM findings. In addition, the response of a pigmented actinic keratosis and a melanoma in situ on sun-damaged skin to noninvasive topical treatment was monitored using RCM. RCM is a promising and practical imaging tool for the diagnosis and follow-up of pigmented and nonpigmented skin lesions. PMID:19782942

Ahlgrimm-Siess, Verena; Hofmann-Wellenhof, Rainer; Cao, Theresa; Oliviero, Margaret; Scope, Alon; Rabinovitz, Harold S

2009-09-01

4

Evaluation of reflectance confocal microscopy in dermatophytosis.  

PubMed

Traditional diagnostic testing for dermatophyte infection currently requires skin scraping for light microscopy and/or fungal culture or skin biopsy. Immunofluorescent microscopy can also be used with calcofluor stain. All of these tests can be time-consuming to perform, require a waiting period for results and are invasive. This study aimed to define the in vivo reflectance confocal microscopy (RCM) features of superficial cutaneous fungal infections and to analyse concordance with microscopic examination. Totally, 45 patients, who were diagnosed with superficial cutaneous fungal infections according to the positive result of microscopic examination, were enrolled in this study. We selected three typical lesions examined by RCM, and then recorded the results. In the patients with the tinea manus and pedis, mycelium in stratum corneum was found by the RCM in 14 of 22 patients (14/22; 63.64%). In the patients with the tinea cruris, mycelium in stratum corneum was found by the RCM in 19 of 23 patients (19/23; 82.61%). RCM seems to be useful for microscopic evaluation of mycelium features and may have a scientific value in study of superficial cutaneous fungal infections. PMID:22963376

Hui, Dai; Xue-cheng, Sun; Ai-e, Xu

2013-03-01

5

Low-cost, scalable laser scanning module for real-time reflectance and fluorescence confocal microscopy  

Microsoft Academic Search

We present a low-cost, high-speed, retrofitted laser scanning module for microscopy. The cage-mounted system, with various available fiber-coupled sources, offers a real-time imaging alternative to costly commercial systems with capabilities for conventional or confocal reflectance and fluorescence applications as well as advanced laser scanning microscopy implementations. Reflectance images of a resolution target and confocal images of fluorescent polystyrene beads are

Derrick R. Chou; Bradley A. Bower; Adam Wax

2005-01-01

6

Fiber confocal reflectance microscope (FCRM) for in-vivo imaging  

NASA Astrophysics Data System (ADS)

In-vivo imaging can be achieved with a coherent-fiber-bundle based confocal reflectance microscope. Such a microscope could provide the means to detect pre-cancerous lesions in the cervix by characterizing cells' nuclear-to-cytoplasmic ratio. In this paper we present the design of such a fiber confocal reflectance microscope, with an emphasis on its optical sub-systems. The optical sub-systems consist of a commercially available microscope objective and custom designed telescope, scan lens, and coupling lens systems. The performance of the fiber confocal reflectance microscope was evaluated by imaging a resolution bar target and human cervical biopsy tissues. The results presented in this paper demonstrate a lateral resolution of 2 µm and axial resolution of 6 µm. The sensitivity of the system defined by the smallest refractive-index mismatch that can be detected is approximately Delta n 0.05.

Liang, Chen; Descour, Michael R.; Sung, Kung-Bin; Richards-Kortum, Rebecca

2001-12-01

7

Fiber confocal reflectance microscope (FCRM) for in-vivo imaging.  

PubMed

In-vivo imaging can be achieved with a coherent-fiber-bundle based confocal reflectance microscope. Such a microscope could provide the means to detect pre-cancerous lesions in the cervix by characterizing cells' nuclear-to-cytoplasmic ratio. In this paper we present the design of such a fiber confocal reflectance microscope, with an emphasis on its optical sub-systems. The optical sub-systems consist of a commercially available microscope objective and custom designed telescope, scan lens, and coupling lens systems. The performance of the fiber confocal reflectance microscope was evaluated by imaging a resolution bar target and human cervical biopsy tissues. The results presented in this paper demonstrate a lateral resolution of 2 microm and axial resolution of 6 microm. The sensitivity of the system defined by the smallest refractive-index mismatch that can be detected is approximately Delta n 0.05. PMID:19424320

Liang, C; Descour, M; Sung, K B; Richards-Kortum, R

2001-12-17

8

Application of avalanche photodiodes to confocal and confocal florescence microscopy  

NASA Astrophysics Data System (ADS)

We describe the use of avalanche photodiodes as solid state photon counters in scanning confocal microscopy. Photon counters have been of limited use for moderate-to-rapid image acquisition speeds due to comparatively low saturation count rates. Several approaches offer the promise of real-time photon-limited image acquisition using off-the-shelf components and dark count rates which are fully adequate for imaging. We characterize in some detail a gated NPN switch/pulse-bias circuit which offers excellent, economical performance over a wide wavelength range, and discuss specific imaging applications.

Brown, Thomas G.; Kreger, Steve T.

1996-04-01

9

Confocal reflectance imaging of excised malignant human bladder biopsies  

NASA Astrophysics Data System (ADS)

To evaluate the potential of reflectance confocal scanning laser microscopy (CM) for rapid imaging of non-processed freshly excised human bladder biopsies and cystectomy specimens. Freshly excised bladder tumors from three cystectomy specimens and random biopsies from twenty patients with a history of superficial bladder tumors were imaged with CM. Additional acetic acid washing prior to CM imaging was performed in some of the samples. Confocal images were compared to corresponding routine histologic sections. CM allows imaging of unprocessed bladder tissue at a subcellular resolution. Urothelial cell layers, collagen, vessels and muscle fibers can be rapidly visualized, in native state. In this regard, umbrella cells, basement membrane elucidated. Besides obvious limitations partly due to non-use of exogenous dyes, CM imaging offers several advantages: rapid imaging of the tissue in its native state like the basement membrane, normally seen only by using immunohistopathology. Reflectance CM opens a new avenue for imaging bladder cancer.

Daniltchenko, Dmitri I.; Kastein, Albrecht; Koenig, Frank; Sachs, Markus; Schnorr, Dietmar; Al-Shukri, Salman; Loening, Stefan A.

2004-08-01

10

Confocal Endomicroscopy: Instrumentation and Medical Applications  

PubMed Central

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.

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

2013-01-01

11

Ophthalmic applications of confocal microscopy: diagnostics, refractive surgery, and eye banking  

NASA Astrophysics Data System (ADS)

Confocal microscopy of ocular tissue provides two advantages over traditional imaging techniques: increased range and transverse resolution and increased contrast. The semitransparent cornea and ocular lens in the living eye can be optically sectioned and observed by reflected light confocal microscopy. Within the cornea we observed various cell components nerve fibers nerve cell bodies and fibrous networks. The confocal microscopic images from the in-situ ocular lens show the lens capsule the lens epithelium and the individual lens fibrils. All of the reflected light confocal microscopic images have high contrast and high resolution. Some of the applications of confocal imaging in ophthalmology include: diagnostics of the cornea and the ocular lens examination prior to and after refractive surgery examination of intraocular lenses (IOL) and examination of eye bank material. Other ophthalmic uses of confocal imaging include: studies of wound healing therapeutics and the effects of contact lenses on the cornea. The proposed features of a clinical confocal microscope are reviewed. 2.

Masters, Barry R.

1990-11-01

12

Distinct melanoma types based on reflectance confocal microscopy.  

PubMed

Distinct melanoma types exist in relation to patient characteristics, tumor morphology, histopathologic aspects and genetic background. A new diagnostic imaging tool, reflectance confocal microscopy (RCM), allows in vivo analysis of a given lesion with nearly histologic resolution while offering a dynamic view of the tissue in its 'natural' environment. The aim of this study was to analyse cell morphology of consecutive melanomas as they appear on RCM and to correlate morphology with tumor and patient characteristics. One hundred melanomas were visualized by RCM before excision. Clinical data, confocal features and histologic criteria were analysed. Four types of melanomas were identified as follows: (i) Melanomas with a predominantly dendritic cell population ('dendritic-cell melanomas') typically were thin by Breslow index; (ii) Melanomas typified by roundish melanocytes were smaller in size than dendritic cell MMs, but thicker by Breslow index, and predominantly occurred in patients with a high nevus count; (iii) Melanomas characterized by dermal nesting proliferation usually were thick by Breslow index at the time of diagnosis, although frequently smaller in size compared with the other types; and (iv) combined type melanomas may represent an evolution of dendritic cell and/or round cell types. Integration of confocal microscopy with clinical and histologic aspects may help in identifying and managing distinct tumors. PMID:24750486

Pellacani, Giovanni; De Pace, Barbara; Reggiani, Camilla; Cesinaro, Anna Maria; Argenziano, Giuseppe; Zalaudek, Iris; Soyer, H Peter; Longo, Caterina

2014-06-01

13

Application of avalanche photodiodes to confocal and confocal florescence microscopy  

Microsoft Academic Search

We describe the use of avalanche photodiodes as solid state photon counters in scanning confocal microscopy. Photon counters have been of limited use for moderate-to-rapid image acquisition speeds due to comparatively low saturation count rates. Several approaches offer the promise of real-time photon-limited image acquisition using off-the-shelf components and dark count rates which are fully adequate for imaging. We characterize

Thomas G. Brown; Steve T. Kreger

1996-01-01

14

Combined FLIM and reflectance confocal microscopy for epithelial imaging  

NASA Astrophysics Data System (ADS)

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 ?m 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..

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

2012-02-01

15

Dual-axes confocal reflectance microscope for distinguishing colonic neoplasia  

PubMed Central

A dual-axes confocal reflectance microscope has been developed that utilizes a narrowband laser at 1310 nm to achieve high axial resolution, image contrast, field of view, and tissue penetration for distinguishing among normal, hyperplastic, and dysplastic colonic mucosa ex vivo. Light is collected off-axis using a low numerical aperture objective to obtain vertical image sections, with 4- to 5-?m resolution, at tissue depths up to 610 ?m. Post-objective scanning enables a large field of view (610 × 640 ?m), and balanced-heterodyne detection provides sensitivity to collect vertical sections at one frame per second. System optics are optimized to effectively reject out-of-focus scattered light without use of a low-coherence gate. This design is scalable to millimeter dimensions, and the results demonstrate the potential for a miniature instrument to detect precancerous tissues, and hence to perform in vivo histopathology.

Liu, Jonathan T. C.; Mandella, Michael J.; Friedland, Shai; Soetikno, Roy; Crawford, James M.; Contag, Christopher H.; Kino, Gordon S.; Wang, Thomas D.

2007-01-01

16

Topographic Variations in Normal Skin, as Viewed by In Vivo Reflectance Confocal Microscopy  

Microsoft Academic Search

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

Misbah Huzaira; Francisca Rius; Milind Rajadhyaksha; R. Rox Anderson; Salvador González

2001-01-01

17

Resolution Enhancement in a Reflection-Type Confocal Microscope with a Phase-Conjugate Mirror  

Microsoft Academic Search

Theoretical and experimental results for a new reflection-type confocal microscope with a phase-conjugate mirror (PCM) are presented. The microscope achieves better lateral and axial resolution than the conventional confocal microscope. The observation volume is reduced considerably (approximately 63%). Owing to the properties of the PCM, the system is self-aligning.

Kristina Uhlendorf; Gunther Notni; Richard Kowarschik

1999-01-01

18

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

PubMed Central

Abstract. 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.

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

2012-01-01

19

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

NASA Astrophysics Data System (ADS)

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.

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

20

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

PubMed Central

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.

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

2013-01-01

21

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

PubMed

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, Se?zary syndrome, or lymphomatoid papulosis were analyzed for presence and absence of RCM features of MF. Cochran and Chi(2) 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, Chi(2) 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. PMID:22352651

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

2012-01-01

22

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

NASA Astrophysics Data System (ADS)

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

Gareau, Daniel

2014-03-01

23

Infuence of fiber terminal face reflection on fiber optical confocal scanning microscope  

NASA Astrophysics Data System (ADS)

In fiber optical confocal scanning imaging system of reflection mode, interference of the reflection light beams from terminal face of the fiber coupling tip and from the surface of the sample will always destroy the image of low reflection index samples, such as CD-R pregroove basal disc and biotic samples. A quantitative analysis was given to find out the influence of fiber terminal face reflection on the system axial response. In order to avoid the influence of the fiber reflected light, the reflectivity ratio of the fiber tip to the sample should be low. Interference noise was effectively reduced by immersing the unused fiber tip into glycerol and cleaving the fiber tip end face at an angle. The proof experimental results of axial response have been shown. Finally, good quality confocal images of the recordable CD pregroove and the chromosome were presented.

Yang, Lisong; Wang, Guiying; Wang, Jiangang; Xu, Zhizhan

1999-09-01

24

Low threshold characteristic of pulsed confocal unstable optical parametric oscillators with Gaussian reflectivity mirrors  

Microsoft Academic Search

An iterative threshold model for a pulsed singly resonant Gaussian-reflectivity-mirror (GRM) confocal unstable optical parametric oscillator (OPO) has been proposed. It is found that OPO threshold is determined by important parameters such as GRM central reflectance, Gaussian reflectivity profile, cavity magnification factor, cavity physical length, crystal length, pump pulsewidth. It is demonstrated that this model can be extended to plane-parallel

Shanshan Zou; Mali Gong; Qiang Liu; Gang Chen

2005-01-01

25

Reflectance confocal microscopy of oral epithelial tissue using an electrically tunable lens  

NASA Astrophysics Data System (ADS)

We present the use of a commercially available electrically tunable lens to achieve axial scanning in a reflectance confocal microscope. Over a 255 ?m axial scan range, the lateral and axial resolutions varied from 1-2 ?m and 4-14 ?m, respectively, dependent on the variable focal length of the tunable lens. Confocal imaging was performed on normal human biopsies from the oral cavity ex vivo. Sub-cellular morphologic features were seen throughout the depth of the epithelium while axially scanning using the focus tunable lens.

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

2014-02-01

26

Total internal reflection fluorescence microscopy imaging-guided confocal single-molecule fluorescence spectroscopy  

PubMed Central

We have developed an integrated spectroscopy system combining total internal reflection fluorescence microscopy imaging with confocal single-molecule fluorescence spectroscopy for two-dimensional interfaces. This spectroscopy approach is capable of both multiple molecules simultaneously sampling and in situ confocal fluorescence dynamics analyses of individual molecules of interest. We have demonstrated the calibration with fluorescent microspheres, and carried out single-molecule spectroscopy measurements. This integrated single-molecule spectroscopy is powerful in studies of single molecule dynamics at interfaces of biological and chemical systems.

Zheng, Desheng; Kaldaras, Leonora; Lu, H. Peter

2012-01-01

27

Low threshold characteristic of pulsed confocal unstable optical parametric oscillators with Gaussian reflectivity mirrors.  

PubMed

An iterative threshold model for a pulsed singly resonant Gaussian-reflectivity-mirror (GRM) confocal unstable optical parametric oscillator (OPO) has been proposed. It is found that OPO threshold is determined by important parameters such as GRM central reflectance, Gaussian reflectivity profile, cavity magnification factor, cavity physical length, crystal length, pump pulsewidth. It is demonstrated that this model can be extended to plane-parallel resonator or uniform-reflectivity-mirror (URM) unstable resonator when some specific values are taken. Experimental results show excellent agreement with values calculated from theoretical model. Both theoretical calculations and experimental data illustrate that GRM is a useful solution to reduce threshold of unstable OPO. PMID:19494938

Zou, Shanshan; Gong, Mali; Liu, Qiang; Chen, Gang

2005-02-01

28

Use of a white light supercontinuum laser for confocal interference-reflection microscopy.  

PubMed

Shortly after its development, the white light supercontinuum laser was applied to confocal scanning microscopy as a more versatile substitute for the multiple monochromatic lasers normally used for the excitation of fluorescence. This light source is now available coupled to commercial confocal fluorescence microscopes. We have evaluated a supercontinuum laser as a source for a different purpose: confocal interferometric imaging of living cells and artificial models by interference reflection. We used light in the range 460-700 nm where this source provides a reasonably flat spectrum, and obtained images free from fringe artefacts caused by the longer coherence length of conventional lasers. We have also obtained images of cytoskeletal detail that is difficult to see with a monochromatic laser. PMID:22432542

Chiu, L-D; Su, L; Reichelt, S; Amos, W B

2012-05-01

29

Superresolution confocal technology for displacement measurements based on total internal reflection  

SciTech Connect

In order to achieve a higher axial resolution for displacement measurement, a novel method is proposed based on total internal reflection filter and confocal microscope principle. A theoretical analysis of the basic measurement principles is presented. The analysis reveals that the proposed confocal detection scheme is effective in enhancing the resolution of nonlinearity of the reflectance curve greatly. In addition, a simple prototype system has been developed based on the theoretical analysis and a series of experiments have been performed under laboratory conditions to verify the system feasibility, accuracy, and stability. The experimental results demonstrate that the axial resolution in displacement measurements is better than 1 nm in a range of 200 nm which is threefold better than that can be achieved using the plane reflector.

Kuang Cuifang; Hao Xiang; Wang Tingting; Liu Xu [State Key Laboratory of Modern Optical Instrumentations, Zhejiang University, Hangzhou 310027 (China); Ali, M. Yakut [Department of Mechanical Engineering, University of South Carolina, Columbia, South Carolina 29208 (United States)

2010-10-15

30

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

NASA Astrophysics Data System (ADS)

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.

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

2009-07-01

31

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

PubMed Central

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.

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

2010-01-01

32

Applications of Dual-Color Confocal Fluorescence Spectroscopy in Biotechnology  

Microsoft Academic Search

\\u000a Classical applications of fluorescence spectroscopy detect emission which is collected from comparatively large ensembles\\u000a of fluorescent particles, i.e. the signal is averaged over space and time. In contrast to this, confocal fluorescence methods\\u000a restrict the probe volume to a tiny spot of less than one femtoliter, which is the size of a typical bacterial cell. The high\\u000a spatial resolution can

A. Koltermann; U. Kettling; J. Stephan; M. Rarbach; T. Winkler; M. Eigen

33

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

PubMed Central

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.

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

2013-01-01

34

In vivo confocal scanning laser microscopy: comparison of the reflectance and fluorescence mode by imaging human skin  

NASA Astrophysics Data System (ADS)

Optical, noninvasive methods have become efficient in vivo tools in dermatological diagnosis and research. From these promising imaging techniques, only the confocal scanning laser microscopy (CSLM) provides visualization of subsurface skin structures with resolutions similar to those of light microscopy. Skin annexes, as well as cutaneous cells from different epidermal layers, can be distinguished excellently. Currently, two forms of application have been established in dermatological practice: the reflectance mode, predominantly in the clinical field, and the fluorescence mode in dermatological research. Differences in both methods exist in the preparative protocol, in maximum imaging depth and, particularly, in the gain of contrast extraction. The reflectance mode demonstrates naturally occurring tissue components, whereas the fluorescent CSLM achieves contrast by administering fluorescence dye, representing the dynamic distribution pattern of the dye's fluorescent emission. Therefore, the reflectance and fluorescent modes highlight various skin microstructures, providing dissimilar in vivo confocal images of the skin. This permits different predications and information on the state of the tissue. We report the advantages and disadvantages of both optical imaging modes. The comparison was drawn by scanning human skin in vivo. Representative images in varying depths were obtained and analyzed; preparation procedures are shown and discussed.

Meyer, Lars E.; Otberg, Nina; Sterry, Wolfram; Lademann, Jürgen

2006-07-01

35

Living matter observations with a novel hyperspectral supercontinuum confocal microscope for VIS to near-IR reflectance spectroscopy.  

PubMed

A broad range hyper-spectroscopic microscope fed by a supercontinuum laser source and equipped with an almost achromatic optical layout is illustrated with detailed explanations of the design, implementation and data. The real novelty of this instrument, a confocal spectroscopic microscope capable of recording high resolution reflectance data in the VIS-IR spectral range from about 500 nm to 2.5 ?m wavelengths, is the possibility of acquiring spectral data at every physical point as defined by lateral coordinates, X and Y, as well as at a depth coordinate, Z, as obtained by the confocal optical sectioning advantage. With this apparatus we collect each single scanning point as a whole spectrum by combining two linear spectral detector arrays, one CCD for the visible range, and one InGaAs infrared array, simultaneously available at the sensor output channel of the home made instrument. This microscope has been developed for biomedical analysis of human skin and other similar applications. Results are shown illustrating the technical performances of the instrument and the capability in extracting information about the composition and the structure of different parts or compartments in biological samples as well as in solid statematter. A complete spectroscopic fingerprinting of samples at microscopic level is shown possible by using statistical analysis on raw data or analytical reflectance models based on Abelés matrix transfer methods. PMID:24233077

Bertani, Francesca R; Ferrari, Luisa; Mussi, Valentina; Botti, Elisabetta; Costanzo, Antonio; Selci, Stefano

2013-01-01

36

In vivo fibered confocal reflectance imaging: totally non-invasive morphological cellular imaging brought to the endoscopist  

NASA Astrophysics Data System (ADS)

This paper presents a novel fibered confocal reflectance microscopy system (FCRM) specifically designed for the medical observation of biological tissues in vivo and in situ, in real time, at the cellular level: the R-600. Reflectance imaging is based on the refraction index difference between biological components while confocal imaging allow to perform the optical sectioning slice in-depth inside the tissues. The R-600 is based on a proximal scanning system, coupled with a 7 mm diameter probe made of tens of thousands of flexible optical fibers allowing in situ imaging, associated with a dedicated software performing real-time control and image processing. The R-600 provides 12 frames per second at an optical imaging depth of 30 microns, with a high lateral resolution, 1 micron, an axial resolution of 2 microns in a field of view 160 microns in diameter. Thanks to the miniaturization of the optical probe, unprecedented accessibility is made possible in organs such as the cervix or the otolaryngological sphere, in a completely non-invasive fashion. The aim of FCRM is to perform optical biopsy. As a first step towards this goal, we present here results obtained in vivo and in real-time on a human mouth , assessing the ability of the R-600 to perform rapid morphologic examination. Subcellular structures such as nuclei and membranes can be clearly distinguished on the images. Further miniaturization opens perspectives for an integrated endoscope-compatible system with broad medical applications.

Osdoit, Anne; Genet, Magalie; Perchant, Aymeric; Loiseau, Sacha; Abrat, Benjamin; Lacombe, François

2006-03-01

37

Applications and characterization of a confocal scanning laser MACROscope/microscope  

NASA Astrophysics Data System (ADS)

Confocal scanning laser microscopes are typically limited to small fields of view less than 5 x 5 mm in size. Scanning stage microscopes can scan very large areas (many centimeters) but are slow. An image can be acquired in seconds on a scanning beam instrument while it can take minutes on a scanning stage microscope. The confocal scanning laser MACROscope was designed previously by the University of Waterloo's Confocal Microscopy Group (UW- CMG) to combine the large scanning area capability of scanning stage microscopes with the fast scanning rates of scanning beam instruments. The prototype MACROscope, described in this thesis, provides 5 and 200 ?m lateral and axial resolution, respectively, using reflected light. It can generate reflected-light, photoluminescence, and optical beam induced current (OBIC) images of areas up to 7.5 x 7.5 cm in less than 10 s. In combination with a conventional scanning beam instrument, submicron resolutions are possible and the field of view can be as small as 25 x 25 ?m representing a zoom factor of 3000. Imaging applications are illustrated for two semiconductor materials: solar cells and porous silicon. Various microscopic and macroscopic, confocal and non- confocal, reflected-light, photoluminescence and OBIC images of solar cells, porous silicon materials, and porous silicon devices are shown. A relay lens consisting of a unitary telescope made with two achromats is examined on CODE V, a lens design and analysis program. This relay lens is known to cause problems on the UW-CMG confocal microscope and it is compared with an all-reflecting telescope made with off- axis parabolic mirrors. CODE V is also used to examine a detector mirror, a 30X all-reflecting beam expander, and an inexpensive ultraviolet objective. A design for a fully integrated, single-instrument confocal scanning laser MACROscope-Microscope is presented. The MACROscope-Microscope has proven to be a versatile, efficient instrument combining scanning beam and scanning stage capabilities and has been demonstrated to be useful in imaging a wide range of specimens. Several new contributions were made to scanning microscopy: (1) Construction of a prototype MACROscope. (2) Development and improvement of the MACROscope. (3) Experimental characterization of the MACROscope and cslm with respect to throughput, lateral resolution, and axial resolution including relative intensity measurements. (4) Experimental evidence and analysis of non-telecentric operation. (5) Demonstration of two imaging applications for the MACROscope: solar cells and porous silicon. (6) Evidence of lateral etching and enhanced photoluminescence in porous silicon specimens was shown. (7) Characterization of a porous silicon device and solar cell with reflected light, photoluminescence, and OBIC. (8) Analysis of the current unitary telescope configuration as well as a reflecting telescope, and an eyepiece telescope with CODE V. Experimental evidence of unitary telescope aberrations was also shown. (9) Analysis of a detector mirror and a UV singlet, for use in imaging, with CODE V. (10) Several suggestions to develop a fully-integrated cslM/m were made. (Abstract shortened by UMI.)

Ribes, Alfonso Carlos

1998-09-01

38

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

Microsoft Academic Search

Summary 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 × 250 µm and a

ALICIA L. CARLSON; LEZLEE G. COGHLAN; ANN M. GILLENWATER; REBECCA R. RICHARDS-KORTUM

2007-01-01

39

Live Cell Refractometry Using Hilbert Phase Microscopy and Confocal Reflectance Microscopy†  

PubMed Central

Quantitative chemical analysis has served as a useful tool for understanding cellular metabolisms in biology. Among many physical properties used in chemical analysis, refractive index in particular has provided molecular concentration that is an important indicator for biological activities. In this report, we present a method of extracting full-field refractive index maps of live cells in their native states. We first record full-field optical thickness maps of living cells by Hilbert phase microscopy and then acquire physical thickness maps of the same cells using a custom-built confocal reflectance microscope. Full-field and axially averaged refractive index maps are acquired from the ratio of optical thickness to physical thickness. The accuracy of the axially averaged index measurement is 0.002. This approach can provide novel biological assays of label-free living cells in situ.

Lue, Niyom; Choi, Wonshik; Popescu, Gabriel; Yaqoob, Zahid; Badizadegan, Kamran; Dasari, Ramachandra R.; Feld, Michael S.

2010-01-01

40

A narrowband dual-axes confocal reflectance microscope for distinguishing colonic neoplasia  

NASA Astrophysics Data System (ADS)

A dual-axes confocal reflectance microscope has been developed that utilizes a narrowband source at 1310 nm to achieve high axial resolution, image contrast, field of view, and tissue penetration for distinguishing among normal, hyperplastic, and dysplastic colonic mucosa ex vivo. Light is collected off-axis using a low numerical aperture objective to obtain vertical image sections, with 4 to 5-?m resolution, at tissue depths up to 610 ?m. Post-objective scanning enables a large field of view (610 x 640 ?m) and balanced-heterodyne detection provides sensitivity to collect vertical sections at two frames per second. System optics are optimized to effectively reject out-of-focus scattered light without use of a low-coherence gate. This design is scalable to millimeter dimensions, and the results demonstrate the potential for a miniature instrument to detect pre-cancerous tissues, and hence to perform in vivo histopathology.

Liu, Jonathan T. C.; Mandella, Michael J.; Contag, Christopher H.; Kino, Gordon S.; Wang, Thomas D.

2006-03-01

41

Dermoscopy and in vivo reflectance confocal microscopy of a congenital nevus of the nipple.  

PubMed

We report a 26-year-old male with a 4 mm diameter, asymmetric, irregularly pigmented and bordered, brown maculopapular lesion on the right nipple present since childhood with enlargement of the lesion within the last 3 months. Dermoscopy revealed a global globular pattern with the presence of focally light brown globules and irregular black globules in its centre. In vivo reflectance confocal microscopy (RCM) revealed dense junctional and dermal melanocytic nests of different sizes and shapes that appeared as sharply demarcated round to oval reflective structures; cellular outlines of single melanocytes were not always detected. In the centre of the lesion within the upper dermis, irregularly shaped, homogeneously reflecting structures were observed. As a clear differentiation between clusters of melanophages and melanocytic nests could not be made with certainty, an excisional biopsy was performed to establish the diagnosis of compound nevus with features of congenital nevus. Therefore, to prove that dermoscopic globules correlated with melanophages, the correlation between dermoscopic RCM and histopathology was necessary. PMID:20805689

Pastar, Zrinjka; Massone, Cesare; Ahlgrimm-Siess, Verena; Koller, Silvia; Mofarrah, Ramin; Hofmann-Wellenhof, Rainer

2010-01-01

42

Virtual pinhole confocal microscope  

SciTech Connect

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.

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

1999-06-01

43

Application of metal nanoparticles in confocal laser scanning microscopy  

Microsoft Academic Search

We describe experiments in which the field enhancement by silver nanoparticles upon surface plasmon excitation has been exploited in confocal laser scanning microscopy to improve the resolution in the direction of the laser beam.

M. Alschinger; N. Borg; F. Hubenthal; M. Maniak; F. Trager

2004-01-01

44

Feasibility of intraoperative imaging during Mohs surgery with reflectance confocal microscopy  

NASA Astrophysics Data System (ADS)

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.

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

2014-03-01

45

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

NASA Astrophysics Data System (ADS)

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.

Sugata, Keiichi; Osanai, Osamu; Kawada, Hiromitsu

2012-02-01

46

The application of confocal technology based on polycapillary X-ray optics in surface topography  

NASA Astrophysics Data System (ADS)

A confocal micro-X-ray fluorescence (MXRF) technology based on polycapillary X-ray optics was proposed for determining surface topography. This confocal topography method involves elemental sensitivity and can be used to classify the objects according to their elemental composition while obtaining their surface topography. To improve the spatial resolution of this confocal topography technology, the center of the confocal micro-volume was overlapped with the output focal spot of the polycapillary X-ray, focusing the lens in the excitation channel. The input focal spot of the X-ray lens parallel to the detection channel was used to determine the surface position of the sample. The corresponding surface adaptive algorithm was designed to obtain the surface topography. The surface topography of a ceramic chip was obtained. This confocal MXRF surface topography method could find application in the materials sciences.

Zhao, Guangcui; Sun, Tianxi; Liu, Zhiguo; Yuan, Hao; Li, Yude; Liu, Hehe; Zhao, Weigang; Zhang, Ruixia; Min, Qin; Peng, Song

2013-09-01

47

Applications of Confocal Laser Scanning Microscopy to Dental Bonding  

Microsoft Academic Search

The introduction of confocal laser scanning microscopy (CLSM) has provided a valuable new technique for the visualization of bonding structures such as a hybrid layer in dentin (Watson, 1989, 1991), In the case of seven commercially-available dentin bonding systems, it could be demonstrated that the CLSM renders considerably more detailed information than the SEM because of its nondestructive nature and

T. Pioch; S. Stotz; H. J. Staehle; H. Duschner

1997-01-01

48

Fiber optic confocal reflectance microscopy: a new real-time technique to view nuclear morphology in cervical squamous epithelium in vivo  

NASA Astrophysics Data System (ADS)

We present a fiber optic confocal reflectance microscope (FCRM) which can be used to image epithelial tissue with sub-cellular resolution in vivo. Confocal images of normal and abnormal appearing cervical tissue were obtained in vivo from eighteen patients undergoing colposcopic examination of the cervix; biopsy specimens were taken from imaged sites. The measured lateral and axial resolutions of the system were 1.6 µm and 3 µm, respectively. Morphologic features, including nuclear size and nuclear-to-cytoplasmic ratio, were extracted from confocal images obtained at various depths beneath the epithelial surface. Image features extracted from confocal images compared well with features extracted from confocal images obtained in vitro and from previous histopathologic studies. This study shows that fiber optic confocal reflectance microscopy can be used to visualize the morphology of cervical epithelium in vivo.

Sung, Kung-Bin; Richards-Kortum, Rebecca; Follen, Michele; Malpica, Anais; Liang, Chen; Descour, Michael R.

2003-12-01

49

Fiber optic confocal reflectance microscopy: a new real-time technique to view nuclear morphology in cervical squamous epithelium in vivo.  

PubMed

We present a fiber optic confocal reflectance microscope (FCRM) which can be used to image epithelial tissue with sub-cellular resolution in vivo. Confocal images of normal and abnormal appearing cervical tissue were obtained in vivo from eighteen patients undergoing colposcopic examination of the cervix; biopsy specimens were taken from imaged sites. The measured lateral and axial resolutions of the system were 1.6 microm and 3 microm, respectively. Morphologic features, including nuclear size and nuclear-to-cytoplasmic ratio, were extracted from confocal images obtained at various depths beneath the epithelial surface. Image features extracted from confocal images compared well with features extracted from confocal images obtained in vitro and from previous histopathologic studies. This study shows that fiber optic confocal reflectance microscopy can be used to visualize the morphology of cervical epithelium in vivo. PMID:19471442

Sung, Kung-Bin; Richards-Kortum, Rebecca; Follen, Michele; Malpica, Anais; Liang, Chen; Descour, Michael

2003-12-01

50

Clinical applications of in vivo fluorescence confocal laser scanning microscopy  

NASA Astrophysics Data System (ADS)

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.

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

2008-03-01

51

Real-time line-scanning reflectance confocal endoscope to enhance sectioning and reduce speckle for intraoral imaging  

NASA Astrophysics Data System (ADS)

The line-scanning confocal microscope is simpler than a point-scanning confocal microscope and allows for a smaller and lower cost footprint, making it attractive for endoscopic clinical use. The optical configuration affects image fidelity. Here, we present a benchtop version of an endoscopic line-scanning confocal microscope for intraoral imaging, with a divided pupil and optimal detection configuration (magnification, pixel-to-resolution ratio) to enhance image fidelity. Improved sectioning performance and reduction of "speckle" noise are demonstrated. A topology for use of a deformable MEMs mirror-based optical axial focus control for imaging in depth is presented. Preliminary images of human oral mucosa in vivo demonstrate feasibility for clinical application.

Glazowski, Christopher; Abeytunge, Sanjeewa; Rajadhyaksha, Milind

2012-02-01

52

Confocal Optical Imaging Systems and Their Applications in Microscopy and Range Sensing  

NASA Astrophysics Data System (ADS)

Confocal optical imaging systems have been the subject of much recent studies. They have found their applications in biomedical imaging and integrated circuit metrology. Confocal systems differ from the standard optical imaging systems in their use of point illumination and point detection, gaining an improved transverse resolution and superior depth resolution. The depth discrimination capability allows confocal imaging systems to optically cross section translucent objects or to image three-dimensional structures. The improvement in transverse resolution permits them to image structures with more detail and better contrast. This thesis has focused on the design and implementation of the confocal optical imaging systems and their applications. A nonparaxial confocal optical imaging theory is developed based on the scalar Rayleigh-Sommerfeld diffraction theory and Sine Condition without the normally-used thin-lens approximation. Two confocal optical range sensors and a Real-time Confocal Scanning Optical Microscope (RSOM) are demonstrated. It is shown that our RSOM has tremendous advantages over other confocal microscopes both in scanning speed and in the ease of use and alignment. The dependence of the imaging characteristics on the pinhole size and the lens is fully discussed. Experimental measurements are compared with the theoretical calculations. Good agreement is obtained. Also demonstrated in this thesis are numerous applications of the RSOM in integrated circuit metrology and biomedical imaging. Deep trenches as narrow as 1 ?m and deep as 6 mu m are observed with the RSOM. The RSOM is not only able to measure the trench depth but, is also able to inspect individual defects inside the trench. Linewidth measurement is also investigated. The RSOM is shown to have an excellent optical cross-sectioning capability. Sectioned images of bones, teeth, and the unprepared cornea of a rabbit eye have been observed. Well-defined sectioned images have been obtained. Fluorescence images have also been taken with the RSOM to demonstrate its image improvement over the standard fluorescence microscope.

Xiao, Guoqing

1990-11-01

53

Conventional and Confocal Epi-Reflection and Fluorescence Microscopy of the Rat Kidney in vivo  

Microsoft Academic Search

To visualize superficial and accessible renal tubule cells functioning in situ and to relate what we can ‘see’ to what we know of their function from more invasive in vivo or less direct in vitro studies means applying and adapting recent advances in epifluorescence and confocal microscopy to improve image resolution and to combine this with the use of fluorescent

Alan Boyde; Giovambattista Capasso; Robert J. Unwin

1998-01-01

54

[Application of confocal technology based on polycapillary X-ray lens in measuring thickness].  

PubMed

A confocal micro X-ray fluorescence thickness gauge based on a polycapillary focusing X-ray lens, a polycapillary parallel X-ray lens and a laboratory X-ray source was designed in order to analyze nondestructively the thickness of thin film and cladding material. The performances of this confocal thickness gauge were studied. Two Ni films with a thickness of about 25 and 15 microm respectively were measured. The relative errors corresponding to them were 3.5% and 7.1%, respectively. The thickness uniformity of a Ni films with a thickness of about 10 microm was analyzed. This confocal technology for measuring the thickness was both spatially resolved and elemental sensitive, and therefore, it could be used to measure the thickness of the multilayer sample and analyze the thickness uniformity of the sample. This confocal thickness gauge had potential applications in analyzing the thickness of sample. PMID:24159881

Peng, Song; Liu, Zhi-Guo; Sun, Tian-Xi; Li, Yu-De; Liu, He-He; Zhao, Wei-Gang; Zhao, Guang-Cui; Lin, Xiao-Yan; Luo, Ping; Pan, Qiu-Li; Ding, Xun-Liang

2013-08-01

55

Real-time, in vivo confocal reflectance microscopy of basal cell carcinoma  

Microsoft Academic Search

Background: Real-time, near-infrared confocal laser scanning microscopy may provide a way to diagnose basal cell carcinoma in vivo and might potentially eliminate the need for invasive diagnostic biopsies in the future. Objective: The purpose of this study is to define the in vivo histologic features of basal cell carcinoma by using a high-resolution imaging technique. Methods: Five fair-skinned white patients

Salvador González; Zeina Tannous

2002-01-01

56

Clinical and microstructural analysis of patients with hyper-reflective corneal endothelial nuclei imaged by in vivo confocal microscopy.  

PubMed

The purpose of this study was to determine the significance of hyper-reflective corneal endothelial nuclei imaged by in vivo confocal microscopy. A retrospective analysis was performed using a database of 505 patients that had undergone in vivo confocal microscopy of the cornea. All subjects with hyper-reflective endothelial nuclei were identified and these images were analysed to determine corneal endothelial cell density and morphology. The clinical notes of these patients were reviewed and corresponding data regarding corneal thickness was obtained from a related database of Orbscan II pachymetry. Hyper-reflective endothelial nuclei were identified in 41 eyes of 39 (7.7%) patients. Diagnoses included previous cataract surgery or penetrating keratoplasty, posterior polymorphous dystrophy, Fuchs' endothelial dystrophy and irido-corneal endothelial syndrome. No patients with clinically normal corneas exhibited bright endothelial nuclei. The mean endothelial cell density in this group was 1325+/-872 cells mm(-2) and endothelial density was below age-adjusted normal values in 69.2% of patients. Both cellular polymegathism (coefficient of variation of cell area 33.9+/-7.4%) and cellular pleomorphism were noted (51.8+/-9.0% hexagonal cells). The mean central corneal thickness was 582+/-52 microm. There was no significant difference in endothelial density and morphology compared to cases that had low endothelial density but did not exhibit bright nuclei. In conclusion, this study is the first to investigate the significance of bright endothelial nuclei detected by in vivo confocal microscopy. The strong association with corneal disease states suggests that the most likely explanation for this appearance is the alteration in cellular/nuclear morphology, composition or function. PMID:16359661

Patel, Dipika V; Phua, Yun Shan; McGhee, Charles N J

2006-04-01

57

Applications of confocal laser scanning microscopy to dental bonding.  

PubMed

The introduction of confocal laser scanning microscopy (CLSM) has provided a valuable new technique for the visualization of bonding structures such as a hybrid layer in dentin (Watson, 1989, 1991). In the case of seven commercially-available dentin bonding systems, it could be demonstrated that the CLSM renders considerably more detailed information than the SEM because of its non-destructive nature and because of the possibility of a distinction between components of bonding agents. With most of the bonding systems, measurements of the thickness of the hybrid layer could be carried out when the primer component was labeled with rhodamine B. It was found that this thickness is significantly increased by increases in etching time and only slightly decreased by increases in the drying time of the dentin and of the primer. When rhodamine B was used for dye penetration tests on four different dentin bonding systems, a leakage within the demineralized zone in the dentin was found in each of the specimens. This structure appears similar to that which Sano et al. (1995) called "nanoleakage". The amount of nanoleakage could not be measured by this method. In the case of enamel or ceramic bonding, a penetration zone was found which corresponded to the etching patterns found in enamel and ceramics, respectively. We conclude that CLSM can offer a wealth of new information about bonding morphology and, therefore, should be used in addition to conventional methods so that the maximum information can be obtained. PMID:9470504

Pioch, T; Stotz, S; Staehle, H J; Duschner, H

1997-11-01

58

Exploiting chromatic aberration to spectrally encode depth in reflectance confocal microscopy  

NASA Astrophysics Data System (ADS)

We present chromatic confocal microscopy as a technique to axially scan the sample by spectrally encoding depth information to avoid mechanical scanning of the lens or sample. We have achieved an 800 ?m focal shift over a range of 680-1080 nm using a hyperchromat lens as the imaging lens. A more complex system that incorporates a water immersion objective to improve axial resolution was built and tested. We determined that increasing objective magnification decreases chromatic shift while improving axial resolution. Furthermore, collimating after the hyperchromat at longer wavelengths yields an increase in focal shift.

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

2011-06-01

59

HIV detection by in-situ hybridization based on confocal reflected light microscopy  

NASA Astrophysics Data System (ADS)

Elucidation of the pathogenesis of AIDS is confounded by the finding that few actively infected CD4+ cells (1 in 104-105) can be detected in the peripheral blood, even though there is dramatic depletion (often >90%) of CD4+ cells as the disease progresses. A sensitive, 35S-based human immunodeficiency virus (HIV) mRNA in situ hybridization technique was coupled with a new detection method, confocal laser scanning microscopy, to examine transcriptionally active HIV-infected cells from individuals at different disease stages. An algorithm for image segmentation and analysis has been developed to determine the proportion of HIV-positive cells. Data obtained using this improved detection method suggest that there are more HIV mRNA-producing cells in HIV-infected individuals than previously thought, based on other detection methods.

Smith, Louis C.; Jericevic, Zeljko; Cuellar, Roland; Paddock, Stephen W.; Lewis, Dorothy E.

1991-05-01

60

Application of confocal laser endomicroscopy in the diagnosis and management of Barrett's esophagus  

PubMed Central

Confocal laser endomicroscopy is an advanced endoscopic imaging modality that can be used for the diagnosis of early mucosal dysplasia in various gastrointestinal conditions. It provides histology-like images at 1000-fold magnification. The technology offers potential advantages in the diagnosis of Barrett’s esophagus and early esophageal cancer due to the low yield of the current practice of surveillance endoscopy with biopsies. Confocal laser endomicroscopy has the potential to eliminate the need for biopsy, establish diagnosis and facilitate application of endoscopic therapy during the time of actual endoscopy. There are several studies that have demonstrated reasonable diagnostic accuracy in patients undergoing surveillance for Barrett’s esophagus from tertiary academic medical centers. However, the application of confocal laser endomicroscopy in routine clinical endoscopy is still in the process of refinement. Its role in the diagnosis and treatment of Barrett’s-associated dysplasia will continue to evolve with improvement in technology, criteria for diagnosis and experience among endoscopists in interpreting confocal imaging.

Leggett, Cadman L.; Gorospe, Emmanuel C.

2014-01-01

61

In vivo confocal microscopy in dermatology: from research to clinical application  

NASA Astrophysics Data System (ADS)

Confocal laser scanning microscopy (CLSM) represents an emerging technique for the noninvasive histomorphological analysis of skin in vivo and has shown its applicability for dermatological research as well as its value as an adjunct tool in the clinical management of skin cancer patients. Herein, we aim to give an overview on the current clinical indications for CLSM in dermatology and also highlight the diverse applications of CLSM in dermatological research.

Ulrich, Martina; Lange-Asschenfeldt, Susanne

2013-06-01

62

Application of confocal laser microscopy for monitoring mesh implants in herniology  

SciTech Connect

The state of the surface of mesh implants and their encapsulation region in herniology is investigated by laser confocal microscopy. A correlation between the probability of developing relapses and the size and density of implant microdefects is experimentally shown. The applicability limits of differential reverse scattering for monitoring the post-operation state of implant and adjacent tissues are established based on model numerical experiments. (optical technologies in biophysics and medicine)

Zakharov, V P; Belokonev, V I; Bratchenko, I A; Timchenko, P E; Vavilov, A V; Volova, L T

2011-04-30

63

A quantitative analysis of the intracellular transport of quantum dot-peptide in live cells using total internal reflection and confocal microscopy  

NASA Astrophysics Data System (ADS)

For investigatoin of intracellular protein interactions, quantum dots are widely used for fluorescent live cell imaging such as total internal reflection fluorescence (TIRF) microscopy and confocal microscopy. In this paper, we performed a quantitative analysis based on fluorescent intensity. For the measurement, A431 cell lines are imaged live with quantum dots using TIRF microscopy. The distribution of quantum dots is affected by a TATHA2 peptide sequence in live cells. This paper also presents the location change of quantum dots due to a nuclear localization signal in A431 cell lines. Confocal microscopy was used to confirm the relation with fluorescent intensity and quantum dot concentration in live cells.

Kim, Kyujung; Kim, Donghyun; Cho, Eun-jin; Huh, Yong-min

2007-03-01

64

A comparative study of allergic contact dermatitis by patch test versus reflectance confocal laser microscopy, with nickel and cobalt.  

PubMed

Few studies have reported on the accuracy of reflectance confocal laser microscopy (RCLM) in observing allergic contact dermatitis in vivo. However, distinction of skin reactions from different reagents is not well understood. We sought to diagnose allergic contact dermatitis by RCLM images and compare with routine, visual patch test (PT) reading for 2 major allergen metals in Japan. The PT was performed on the upper back skin with 5% nickel sulfate (Ni) and 2% cobalt chloride (Co) in eight healthy volunteers and eleven patients. RCLM was used to calculate the thickness of the suprabasal epidermis after visual assessment of PT. Comparison of clinical scoring versus suprabasal epidermal thickness was observed. RCLM images of positive PT showed increased suprabasal epidermal thickness on day 2 (D2), and D3 for Co, whereas there was vesicle formation and an overall increase suprabasal epidermal thickness for Ni. In two of 3 doubtful positive PT to Co, RCLM images presented characteristics of irritant reactions; and one characteristic of a positive reaction. The frequency of Co doubtful-positive PT was higher than that of Ni. We found advantages in using RCLM for visualizing features of allergic contact dermatitis and found it a useful tool as an objective parameter in grading severity and types of PT reaction. PMID:20822971

Sakanashi, Emi Nishijima; Matsumura, Mitsuaki; Kikuchi, Katsuko; Ikeda, Masaomi; Miura, Hiroyuki

2010-01-01

65

Langerhans cells and melanocytes share similar morphologic features under in vivo reflectance confocal microscopy: a challenge for melanoma diagnosis  

PubMed Central

Background Intraepidermal Langerhans cells (ILC) are difficult to differentiate from melanocytes under reflectance confocal microscopy (RCM) and their presence may simulate pagetoid spread of melanocytes on RCM images. Objective To correlate bright round and dendritic cells in a pagetoid pattern identified on RCM with findings of conventional histopathology and immunohistochemistry for lesions that were falsely diagnosed as melanoma by RCM. Methods This retrospective study included histopathologically proven nevi, imaged by RCM, which displayed bright cells in a pagetoid pattern (BCPP) under RCM, resulting in the incorrect RCM diagnosis of melanoma. Morphological comparisons were histopathologically proven melanomas displaying BCPP on RCM and biopsy-proven nevi without such cells on RCM. Results We identified 24 nevi that were falsely diagnosed as melanoma by RCM due to the presence of BCPP. These pagetoid cells on RCM corresponded on histopathology to ILC with a high density in 23 of the 24 nevi (95%) and to melanocytes in 7 of the 24 nevi (29%). Among 6 melanomas displaying BCPP on RCM, ILC with high density were observed histopathologically in 5 of the 6 cases (83%) and pagetoid melanocytes were seen in all 6 cases (100%). Limitations The results cannot be generalized to clinically banal-appearing nevi. Conclusions Although the finding of BCPP is a useful RCM feature for the diagnosis of melanoma it does not always imply the presence of pagetoid melanocytes but may at times, represent ILC.

Hashemi, Pantea; Pulitzer, Melissa P.; Scope, Alon; Kovalyshyn, Ivanka; Halpern, Allan C.; Marghoob, Ashfaq A.

2011-01-01

66

In vivo detection of basal cell carcinoma: comparison of a reflectance confocal microscope and a multiphoton tomograph  

NASA Astrophysics Data System (ADS)

The standard diagnostic procedure for basal cell carcinoma (BCC) is invasive tissue biopsy with time-consuming histological examination. To reduce the number of biopsies, noninvasive optical methods have been developed providing high-resolution skin examination. We present direct comparison of a reflectance confocal microscope (RLSM) and a multiphoton tomograph (MPT) for BCC diagnosis. Both systems are applied to nine patients prior to surgery, and the results are analyzed, including histological results. Both systems prove suitable for detecting typical characteristics of BCC in various stages. The RLSM allows large horizontal overview images to be obtained, enabling the investigator to find the regions of interest quickly, e.g., BCC nests. Elongated cells and palisading structures are easily recognized using both methods. Due to the higher resolution, changes in nucleus diameter or cytoplasm could be visualized with the MPT. Therefore, the nucleus diameter, nucleus/cytoplasm ratio, and cell density are estimated for normal and BCC cells using the MPT. The nucleus of elongated BCC cells is significantly longer than other measured normal skin cells, whereas the cell density and nucleus/cytoplasm ratio of BCC cannot be significantly distinguished from granular cells.

Ulrich, Martina; Klemp, Marisa; Darvin, Maxim E.; König, Karsten; Lademann, Jürgen; Meinke, Martina C.

2013-06-01

67

In vivo imaging of enamel by reflectance confocal microscopy (RCM): non-invasive analysis of dental surface.  

PubMed

The aim is to establish the feasibility to image in vivo microscopic dental surface by non-invasive, real-time, en face Reflectance Confocal Microscopy (RCM). Fifteen healthy volunteers referred at the Multidisciplinary Department of Medical-Surgical and Odontostomatological Specialties, Second University of Naples, Naples, Italy, were enrolled. A commercially available hand-held RCM (Vivascope(®)3000, Lucid, Rochester, NY, USA) was used to image in vivo the dental surface of the upper right and left central incisors of each volunteer. Totally, thirty vestibular surfaces of upper central incisors were imaged in vivo by RCM to preliminary image the dental surface and assess the feasibility of a more extended study on teeth. In vivo RCM was able to image the dental surface within the enamel, at a maximum depth imaging of 300 ?m, with images good in quality and the capability to detect enamel structures such as enamel lamellae and enamel damages, such as unevenness and cracks. In conclusion, enamel "optical biopsy", gained by RCM imaging, revealed to be a non-invasive real-time tool valid to obtain architectural details of the dental surface with no need for extraction or processing the samples. RCM appears to be an optimum auxiliary device for investigating the architectural pattern of superficial enamel, therefore inviting further experiments aimed to define our knowledge about damages after etching treatments or bracket removal and the responsiveness to fluoride seals and the morphology of the tooth/restoration interface. Moreover, this device could also be used to detect relevant diseases like caries, or to assess surface properties to evaluate lesion activity. PMID:23584400

Contaldo, Maria; Serpico, Rosario; Lucchese, Alberta

2013-04-13

68

Semi-automated algorithm for localization of dermal/epidermal junction in reflectance confocal microscopy images of human skin  

NASA Astrophysics Data System (ADS)

The examination of the dermis/epidermis junction (DEJ) is clinically important for skin cancer diagnosis. Reflectance confocal microscopy (RCM) is an emerging tool for detection of skin cancers in vivo. However, visual localization of the DEJ in RCM images, with high accuracy and repeatability, is challenging, especially in fair skin, due to low contrast, heterogeneous structure and high inter- and intra-subject variability. We recently proposed a semi-automated algorithm to localize the DEJ in z-stacks of RCM images of fair skin, based on feature segmentation and classification. Here we extend the algorithm to dark skin. The extended algorithm first decides the skin type and then applies the appropriate DEJ localization method. In dark skin, strong backscatter from the pigment melanin causes the basal cells above the DEJ to appear with high contrast. To locate those high contrast regions, the algorithm operates on small tiles (regions) and finds the peaks of the smoothed average intensity depth profile of each tile. However, for some tiles, due to heterogeneity, multiple peaks in the depth profile exist and the strongest peak might not be the basal layer peak. To select the correct peak, basal cells are represented with a vector of texture features. The peak with most similar features to this feature vector is selected. The results show that the algorithm detected the skin types correctly for all 17 stacks tested (8 fair, 9 dark). The DEJ detection algorithm achieved an average distance from the ground truth DEJ surface of around 4.7?m for dark skin and around 7-14?m for fair skin.

Kurugol, Sila; Dy, Jennifer G.; Rajadhyaksha, Milind; Gossage, Kirk W.; Weissmann, Jesse; Brooks, Dana H.

2011-02-01

69

Characterization and applications of a new tabletop confocal micro X-ray fluorescence setup  

NASA Astrophysics Data System (ADS)

A tabletop confocal three-dimensional micro X-ray fluorescence (3D micro-XRF) setup was designed, based on polycapillary X-ray optics and a micro-focus X-ray source. This confocal setup consists of a polycapillary full lens to focus the incident beam and a polycapillary half lens to collect the X-ray fluorescence. The confocal volume was proved to be ellipsoidal. The full-width at half maximum (FWHM) of the confocal volume in three directions were measured with a "knife edge" scan method to obtain the spatial resolution of the confocal setup. The structure of multilayer samples was studied using the depth scan technique.

Lin, Xiaoyan; Wang, Zhihong; Sun, Tianxi; Pan, Qiuli; Ding, Xunliang

2008-06-01

70

Reflectance confocal microscope for imaging oral tissues in vivo, potentially with line scanning as a low-cost approach for clinical use  

NASA Astrophysics Data System (ADS)

Reflectance confocal microscopy with a line scanning approach potentially offers a smaller, simpler and less expensive approach than traditional methods of point scanning for imaging in living tissues. With one moving mechanical element (galvanometric scanner), a linear array detector and off-the-shelf optics, we designed a compact (102x102x76mm) line scanning confocal reflectance microscope (LSCRM) for imaging human tissues in vivo in a clinical setting. Custom-designed electronics, based on field programmable gate array (FPGA) logic has been developed. With 405 nm illumination and a custom objective lens of numerical aperture 0.5, lateral resolution was measured to be 0.8 um (calculated 0.64 um). The calculated optical sectioning is 3.2 um. Preliminary imaging shows nuclear and cellular detail in human skin and oral epithelium in vivo. Blood flow is also visualized in the deeper connective tissue (lamina propria) in oral mucosa. Since a line is confocal only in one dimension (parallel) but not in the other, the detection is more sensitive to multiply scattered out of focus background noise than in the traditional point scanning configuration. Based on the results of our translational studies thus far, a simpler, smaller and lower-cost approach based on a LSCRM appears to be promising for clinical imaging.

Peterson, Gary; Abeytunge, Sanjeewa; Eastman, Zachary; Rajadhyaksha, Milind

2012-02-01

71

Characterization and applications of a new tabletop confocal micro X-ray fluorescence setup  

Microsoft Academic Search

A tabletop confocal three-dimensional micro X-ray fluorescence (3D micro-XRF) setup was designed, based on polycapillary X-ray optics and a micro-focus X-ray source. This confocal setup consists of a polycapillary full lens to focus the incident beam and a polycapillary half lens to collect the X-ray fluorescence. The confocal volume was proved to be ellipsoidal. The full-width at half maximum (FWHM)

Xiaoyan Lin; Zhihong Wang; Tianxi Sun; Qiuli Pan; Xunliang Ding

2008-01-01

72

Chromatic confocal spectral interferometry.  

PubMed

Chromatic confocal spectral interferometry (CCSI) is a novel scheme for topography measurements that combines the techniques of spectral interferometry and chromatic confocal microscopy. This hybrid method allows for white-light interferometric detection with a high NA in a single-shot manner. To the best of our knowledge, CCSI is the first interferometric method that utilizes a confocally filtered and chromatically dispersed focus for detection and simultaneously allows for retrieval of the depth position of reflecting or scattering objects utilizing the phase (modulation frequency) of the interferometric signals acquired. With the chromatically dispersed focus, the depth range of the sensor is decoupled from the NA of the microscope objective. PMID:17068567

Papastathopoulos, Evangelos; Körner, Klaus; Osten, Wolfgang

2006-11-10

73

Chromatic confocal spectral interferometry  

SciTech Connect

Chromatic confocal spectral interferomertry (CCSI) is a novel scheme for topography measurements that combines the techniques of spectral interferometry and chromatic confocal microscopy. This hybrid method allows for white-light interferometric detection with a high NA in a single-shot manner. To the best of our knowledge, CCSI is the first interferometric method that utilizes a confocally filtered and chromatically dispersed focus for detection and simultaneously allows for retrieval of the depth position of reflecting or scattering objects utilizing the phase (modulation frequency) of the interferometric signals acquired. With the chromatically dispersed focus, the depth range of the sensor is decoupled from the NA of the microscope objective.

Papastathopoulos, Evangelos; Koerner, Klaus; Osten, Wolfgang

2006-11-10

74

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

Microsoft Academic Search

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

K. Paul Kirkbride; Silvana R. Tridico

2010-01-01

75

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

PubMed Central

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.

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

2014-01-01

76

Optical Sectioning and Confocal Microscopy  

NSDL National Science Digital Library

Confocal microscopy is a powerful technique for acquiring three-dimensional images of biological samples. Here I discuss the basic principles of confocal microscopy, with specific discussions of the operation of laser scanning and spinning disk confocal microscopes and of their application to biology.

Kurt Thorn (Nikon Imaging Center, University of California, San Francisco;)

2009-06-01

77

Research and application on imaging technology of line structure light based on confocal microscopy  

NASA Astrophysics Data System (ADS)

In 2005, the theory of line structure light confocal microscopy was put forward firstly in China by Xingyu Gao and Zexin Xiao in the Institute of Opt-mechatronics of Guilin University of Electronic Technology. Though the lateral resolution of line confocal microscopy can only reach or approach the level of the traditional dot confocal microscopy. But compared with traditional dot confocal microscopy, it has two advantages: first, by substituting line scanning for dot scanning, plane imaging only performs one-dimensional scanning, with imaging velocity greatly improved and scanning mechanism simplified, second, transfer quantity of light is greatly improved by substituting detection hairline for detection pinhole, and low illumination CCD is used directly to collect images instead of photoelectric intensifier. In order to apply the line confocal microscopy to practical system, based on the further research on the theory of the line confocal microscopy, imaging technology of line structure light is put forward on condition of implementation of confocal microscopy. Its validity and reliability are also verified by experiments.

Han, Wenfeng; Xiao, Zexin; Wang, Xiaofen

2009-11-01

78

Implementing Application Specific RTOS Policies using Reflection  

Microsoft Academic Search

Conventionally, a real-time operating system (RTOS) is built without knowing which specific applications is executed upon it. The RTOS is built for the general case, rather than to meet the specific requirements of an application. This paper proposes a generic module-based reflective framework to implement an RTOS that allows applications to dynamically adapt the policies within the RTOS to better

Ameet Patil; Neil C. Audsley

2005-01-01

79

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...

80

Application of metal nanoparticles in confocal laser scanning microscopy: improved resolution by optical field enhancement  

Microsoft Academic Search

We describe experiments in which the field enhancement by metal nanoparticles that accompanies surface plasmon excitation has been exploited in confocal laser scanning microscopy. The objective was to make use of the rapid decay of the enhanced light field with distance from the nanoparticles to increase the longitudinal resolution, by confining the emission of fluorescence light to the immediate vicinity

M. Alschinger; M. Maniak; F. Stietz; T. Vartanyan; F. Träger

2003-01-01

81

Parallelized chromatic confocal sensor systems  

NASA Astrophysics Data System (ADS)

In this paper we present chromatic confocal distance sensors for the parallelized evaluation at several lateral positions. The multi-point measurements are performed using either one- or two-dimensional detector arrays. The first sensor combines the concepts of confocal matrix sensing and snapshot hyperspectral imaging to image a two-dimensional array of laterally separated points with one single shot. In contrast to chromatic confocal matrix sensors which use an RGB detector our system works independently from the spectral reflectivity of the surface under test and requires no object-specific calibration. Our discussion of this sensor principle is supported by experimental results. The second sensor is a multipoint line sensor aimed at high speed applications with frame rates of several thousand frames per second. To reach this evaluation speed a one-dimensional detector is employed. We use spectral multiplexing to transfer the information from different measurement points through a single fiber and evaluate the spectral distribution with a conventional spectrometer. The working principle of the second sensor type is demonstrated for the example of a three-point sensor.

Hillenbrand, Matthias; Grewe, Adrian; Bichra, Mohamed; Kleindienst, Roman; Lorenz, Lucia; Kirner, Raoul; Weiß, Robert; Sinzinger, Stefan

2013-04-01

82

[Application of confocal micro-beam X-ray fluorescence in nondestructive scanning analysis of the distribution of elements in a single hair].  

PubMed

The confocal micro X-ray fluorescence (XRF) based on polycapillary X-ray lens and conventional X-ray source was used to carry out the scanning analysis of the distribution of the elements in a single hair. The elemental distribution in the single hair was obtained. In the confocal micro XRF technology, the output focal spot of the polycapillary focusing X-ray lens and the input focal spot of the polycapillary parallel X-ray lens were adjusted confocally. The detector could only detect the X-rays from the overlapping foci. This confocal structure decreased the effects of the background on the X-ray spectra, and was accordingly helpful for improving the accuracy of this XRF technology. A polycapillary focusing X-ray lens with a high gain in power density was used to decrease the requirement of power of the X-ray source used in this confocal technology, and made it possible to perform such confocal micro XRF analysis by using the conventional X-ray source with low cost. Experimental results indicated that the confocal micro X-ray fluorescence based on polycapillary X-ray lens had potential applications in analyzing the elemental distribution of individual hairs. PMID:24555400

Liu, He-He; Liu, Zhi-Guo; Sun, Tian-Xi; Peng, Song; Zhao, Wei-Gang; Sun, Wei-Yuan; Li, Yu-De; Lin, Xiao-Yan; Zhao, Guang-Cui; Luo, Ping; Ding, Xun-Liang

2013-11-01

83

Optical spectrometer for a confocal scanning laser microscope with applications in porphyrin-containing specimens  

NASA Astrophysics Data System (ADS)

A spectrometer has been developed for the Phoibos confocal scanning laser microscope. With this spectrometer, spectral information from a single point, or a user defined region, within the microscope specimen, can be recorded. The spectrometer is based on an integrated spectrometer module, manufactured by Carl Zeiss, Germany. The module takes its light input signal through a fiber with an entrance diameter of 0.5 mm. Integrated in the spectrometer module are dispersing optics, based on a grating, as well as preamplifier electronics. A regulated cooling unit keeps the detector at -4 degree(s)C, thereby allowing longer integration times. The spectral resolution, defined as the minimum distance between two peaks (Rayleigh criterion) is approximately 10 nm. The entrance of the optical fiber is employed as a pinhole. With different magnification in the optical path leading the light to the spectrometer, the entrance can either be employed as a pinhole of the same size as the one used during conventional confocal scanning, i.e. the 3D spatial resolution will be retained, or the light throughput can be increased at the expense of optical resolution. With the described equipment, studies of rodent lung and liver specimens containing porphyrins have been made. Organs from animals injected with (delta) -amino levulinic acid, a precursor to protoporphyrin IX and haem in the haem cycle, have been studied. Spectroscopic detection is necessary in order to separate the porphyrin signal from other fluorescent components in the specimen.

Trepte, Oliver; Rokahr, Ingrid; Andersson-Engels, Stefan

1995-03-01

84

Confocal microscopy: a new era in understanding the pathophysiologic background of inflammatory skin diseases.  

PubMed

One of the emerging and intriguing applications of reflectance confocal microscopy is the evaluation of 'dynamic' processes of the skin that cannot be otherwise analysed using histopathology that offers a picture of the tissue at one time point. This is nicely illustrated by recent article by Wolberink et al. in the current issue of Exp Dermatol, in which the Authors evaluated patterns and time interval of polymorphonuclear neutrophil (PMN) migration in psoriatic plaques by means of reflectance confocal microscopy (RCM). This example underscores that a new era of confocal microscopy is starting, which promises to reveal a dynamic in vivo understanding of the pathophysiology of human skin diseases. PMID:24593193

Moscarella, Elvira; Argenziano, Giuseppe; Lallas, Aimilios; Pellacani, Giovanni; Longo, Caterina

2014-05-01

85

The impact of in vivo reflectance confocal microscopy on the diagnostic accuracy of lentigo maligna and equivocal pigmented and nonpigmented macules of the face.  

PubMed

Limited studies have reported the in vivo reflectance confocal microscopy (RCM) features of lentigo maligna (LM). A total of 64 RCM features were scored retrospectively and blinded to diagnosis in a consecutive series of RCM sampled, clinically equivocal, macules of the face (n=81 LM, n=203 benign macules (BMs)). In addition to describing RCM diagnostic features for LM (univariate), an algorithm was developed (LM score) to distinguish LM from BM. This comprised two major features each scoring +2 points (nonedged papillae and round large pagetoid cells > 20 microm), and four minor features; three scored +1 point each (three or more atypical cells at the dermoepidermal junction in five 0.5 x 0.5 mm(2) fields, follicular localization of atypical cells, and nucleated cells within the dermal papillae), and one (negative) feature scored -1 point (a broadened honeycomb pattern). A LM score of > or = 2 resulted in a sensitivity of 85% and specificity of 76% for the diagnosis of LM (odds ratio (OR) for LM 18.6; 95% confidence interval: 9.3-37.1). The algorithm was equally effective in the diagnosis of amelanotic lesions and showed good interobserver reproducibility (87%). In a test set of 29 LMs and 44 BMs, the OR for LM was 60.7 (confidence interval: 11.9-309) (93% sensitivity, 82% specificity). PMID:20393481

Guitera, Pascale; Pellacani, Giovanni; Crotty, Kerry A; Scolyer, Richard A; Li, Ling-Xi L; Bassoli, Sara; Vinceti, Marco; Rabinovitz, Harold; Longo, Caterina; Menzies, Scott W

2010-08-01

86

Segmentation and measurement based on 3D Voronoi diagram: application to confocal microscopy.  

PubMed

Computational geometry provides many solutions to imaging problems, especially for three-dimensional (3D) image compression, segmentation, and measurement. We present here a new method to partition volume data by Voronoi polyhedra structured in a graph environment. A dynamic construction of the 3D Voronoi diagram is proposed, using image information interactively. The process has been applied to segment and quantitate 3D biological data acquired with a confocal laser scanning microscope (CLSM). The discrete volume acquired represents a large mass of data and can be reduced with this particular method, before measurement (processing time) or archiving (memory space). Furthermore, the structure data is a powerful tool to rapidly compute parameters that are characteristic of the volume data. PMID:8402524

Bertin, E; Parazza, F; Chassery, J M

1993-01-01

87

Multifluorescence confocal microscopy: application for a quantitative analysis of hemostatic proteins in human venous valves.  

PubMed

Confocal laser scanning microscopy is commonly used to visualize and quantify protein expression. Visualization of the expression of multiple proteins in the same region via multifluorescence allows for the analysis of differential protein expression. The defining step of multifluorescence labeling is the selection of primary antibodies from different host species. In addition, species-appropriate secondary antibodies must also be conjugated to different fluorophores so that each protein can be visualized in separate channels. Quantitative analysis of proteins labeled via multifluorescence can be used to compare relative changes in protein expression. Multifluoresecence labeling and analysis of fluorescence intensity within and among human venous specimens, for example, allowed us to determine that the anticoagulant phenotype of the venous valve is defined not by increased anticoagulant expression, but instead by significantly decreased procoagulant protein expression (Blood 114:1276-1279, 2009 and Histochem Cell Biol 135:141-152, 2011). PMID:23026998

Trotman, Winifred E; Taatjes, Douglas J; Bovill, Edwin G

2013-01-01

88

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

PubMed Central

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.

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

2013-01-01

89

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

NASA Technical Reports Server (NTRS)

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.

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

1997-01-01

90

A novel confocal line scanning sensor  

NASA Astrophysics Data System (ADS)

Optical methods, including confocal microscopes, are widely used for measurements of surface topography. The knowledge of surface morphology and roughness parameters is crucial for many applications, i.e. in industrial and automotive environment, in tribology, wear and functionality prediction. However, confocal microscopy has a limited field of view. A time consuming stitching process is required for extending to long profile lines measurement. Therefore, in this paper we present a novel concept of a Confocal Line Scanning Sensor (CLSS) to cover theoretically infinite profile lengths. The new technique is proposed with no moving parts required for axial scanning, and it has a simpler setup than those of Chromatic Confocal Sensor (CCS). The idea is to produce a stack of focal points on an inclined plane covering a certain axial measurement range. Therefore, by scanning the stack of focal points in lateral direction we can realize a long profile line. By doing that we expect to achieve shorter scanning time, while providing high lateral and axial resolution by using a true confocal principle. A long profile line of a few ten millimeters with a lateral resolution in sub-micrometer range and an axial resolution in tens of nanometers can be expected. Moreover, this concept is easily extensible to an areal measurement. Among other key components, a new design of the pinhole mask has been developed. We design it to produce an inclined focal line with optimum optical parameters. Optimization of the pinhole design fulfills two objectives; minimizing its size by allowing optimal reflected-light intensity, and minimizing crosstalk between nearby pinholes. Further detail of the pinhole design is beyond a scope of this paper. In this paper an overview of the new concept is presented, accompanied by validation of first experimental results.

Chanbai, Sirichanok; Wiora, Georg; Weber, Mark; Roth, Hubert

2009-05-01

91

Enhanced quantitative confocal microscopy and its application for the measurement of tympanic membrane thickness  

NASA Astrophysics Data System (ADS)

This work shows that confocal microscopy allows a quantitative study of delicate 3D-biotissue in fresh condition, thus avoiding histological preparation processes. The developed procedure results in exact and accurate thickness data for mum-sized objects with a measuring error of less than 1mum. It is, however, necessary to take into account the effect of focal shift in the case of refractive index mismatch to obtain such precise data. The use of the proposed method is advised instead of the use of a paraxial approximation for the axial scale correction because the method improves measurement precision by a factor of four. The axial scaling correction factors obtained in this work show that for most practical situations the correction cannot be ignored when one wants to obtain precise quantitative data. The thickness correction method can also be used to determine with high accuracy the index of refraction of biological tissue. The thickness measurement method was applied to fresh, untreated tympanic membranes of the gerbil, the cat and the human. Thickness had to be measured at many points as it differs strongly across the membrane. Similar thickness distributions were found in all pars tensas measured even across the species studied: (1) a very thin, central region with a rather constant thickness, curving as a horse shoe upwards around the manubrium (thickness: gerbil: about 7mum, cat: about 10mum, human: large inter-specimen variation: 40mum-120mum), (2) a thinnest zone at the inferior side, (3) a thicker zone at the supero-anterior side, (4) superior to the umbo, an anterior region thicker than the posterior region, (5) maximal thicknesses in a very small region near the entire manubrium and the entire annular periphery. The pars flaccida is found to be thicker than the pars tensa. It shows no central homogeneous zone: the thickness varies irregularly and very rapidly over short distances. Arbitrarily spaced bumps and notches are present over the entire pars flaccida surface. The thickness results advise against the use of single thickness values in mathematical models. The presented thickness and its spatial distribution can be introduced into middle ear computer models to further improve model realism.

Kuypers, Liesbeth

92

Total Internal Reflection Ellipsometry: Principles and Applications  

Microsoft Academic Search

A concept for a measurement technique based on ellipsometry in conditions of total internal reflection is presented. When combined with surface plasmon resonance (SPR) effects, this technique becomes powerful for monitoring and analyzing adsorption and desorption on thin semitransparent metal films as well as for analyzing the semitransparent films themselves. We call this technique total internal reflection ellipsometry (TIRE). The

Hans Arwin; Michal Poksinski; Knut Johansen

2004-01-01

93

Confocal profilometer with nanometric vertical resolution.  

National Technical Information Service (NTIS)

An optical system is described which is based on the method of Kobayashi et al. The instrument is capable of simultaneous confocal imaging and profilometry with nanometric (nm) vertical resolution. The profile is independent of the reflectivity of the sam...

D. J. Butler A. Horsfall M. Hrynevych P. D. Kearney K. A. Nugent

1992-01-01

94

Confocal Microscopy Through a Fiber-Optic Imaging Bundle.  

NASA Astrophysics Data System (ADS)

This dissertation describes the implementation of confocal microscopy through a fiber-optic imaging bundle. This system, the fiber-optic imaging-bundle confocal microscope, permits the optical-sectioning effect of confocal microscopy to be applied to a range of samples inaccessible to a conventional confocal microscope. Two such systems were designed and built. The first system is a modified laboratory microscope used to demonstrate and evaluate the performance of the fiber-optic imaging-bundle confocal microscope. The second system is a real-time slit-scanning microscope that is expected to be a suitable design for in-vivo medical applications. Fiber-optic imaging bundles are discussed in some detail. A number of parameters of three flexible silica imaging bundles were measured and the suitability of these bundles for use in the microscope is evaluated. A new reflection technique for measurement of optical-fiber refractive indices was developed and applied to the evaluation of these imaging bundles.

Aziz, David Joshua

1995-01-01

95

Application of a femtosecond self-sustaining mode-locked Ti:sapphire laser to the field of laser scanning confocal microscopy  

Microsoft Academic Search

Developments in ultrafast Ti:sapphire laser technology can be applied in the investigation of nonlinear optical processes. We describe the application of a self-sustaining femtosecond Ti:sapphire laser as an illumination source in the field of confocal laser scanning fluorescence microscopy (LSM). We present spectra for various fluorescent stains under two-photon excitation and present LSM images of stained samples under mode-locked illumination.

P. F. Curley; A. I. Ferguson; J. G. White; W. B. Amos

1992-01-01

96

Video-rate Scanning Confocal Microscopy and Microendoscopy  

PubMed Central

Confocal microscopy has become an invaluable tool in biology and the biomedical sciences, enabling rapid, high-sensitivity, and high-resolution optical sectioning of complex systems. Confocal microscopy is routinely used, for example, to study specific cellular targets1, monitor dynamics in living cells2-4, and visualize the three dimensional evolution of entire organisms5,6. Extensions of confocal imaging systems, such as confocal microendoscopes, allow for high-resolution imaging in vivo7 and are currently being applied to disease imaging and diagnosis in clinical settings8,9. Confocal microscopy provides three-dimensional resolution by creating so-called "optical sections" using straightforward geometrical optics. In a standard wide-field microscope, fluorescence generated from a sample is collected by an objective lens and relayed directly to a detector. While acceptable for imaging thin samples, thick samples become blurred by fluorescence generated above and below the objective focal plane. In contrast, confocal microscopy enables virtual, optical sectioning of samples, rejecting out-of-focus light to build high resolution three-dimensional representations of samples. Confocal microscopes achieve this feat by using a confocal aperture in the detection beam path. The fluorescence collected from a sample by the objective is relayed back through the scanning mirrors and through the primary dichroic mirror, a mirror carefully selected to reflect shorter wavelengths such as the laser excitation beam while passing the longer, Stokes-shifted fluorescence emission. This long-wavelength fluorescence signal is then passed to a pair of lenses on either side of a pinhole that is positioned at a plane exactly conjugate with the focal plane of the objective lens. Photons collected from the focal volume of the object are collimated by the objective lens and are focused by the confocal lenses through the pinhole. Fluorescence generated above or below the focal plane will therefore not be collimated properly, and will not pass through the confocal pinhole1, creating an optical section in which only light from the microscope focus is visible. (Fig 1). Thus the pinhole effectively acts as a virtual aperture in the focal plane, confining the detected emission to only one limited spatial location. Modern commercial confocal microscopes offer users fully automated operation, making formerly complex imaging procedures relatively straightforward and accessible. Despite the flexibility and power of these systems, commercial confocal microscopes are not well suited for all confocal imaging tasks, such as many in vivo imaging applications. Without the ability to create customized imaging systems to meet their needs, important experiments can remain out of reach to many scientists. In this article, we provide a step-by-step method for the complete construction of a custom, video-rate confocal imaging system from basic components. The upright microscope will be constructed using a resonant galvanometric mirror to provide the fast scanning axis, while a standard speed resonant galvanometric mirror will scan the slow axis. To create a precise scanned beam in the objective lens focus, these mirrors will be positioned at the so-called telecentric planes using four relay lenses. Confocal detection will be accomplished using a standard, off-the-shelf photomultiplier tube (PMT), and the images will be captured and displayed using a Matrox framegrabber card and the included software.

Nichols, Alexander J.; Evans, Conor L.

2011-01-01

97

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...

98

Binary phase digital reflection holograms - Fabrication and potential applications  

NASA Technical Reports Server (NTRS)

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.

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

1977-01-01

99

Materials for reflective coatings of window glass applications  

Microsoft Academic Search

Special glass with reflective coatings has found wide applications in architecture. Thin coatings deposited on glass panes modulate the glass optical properties. Some of the coatings operate as a mirror for long-wave infrared radiation of building interiors. The thin films have high transmittance in visible range and very high reflectance in long-wave infrared range. These coatings limit absorption of infrared

Jitka Mohelnikova

2009-01-01

100

Evaluation of atlas selection strategies for atlas-based image segmentation with application to confocal microscopy images of bee brains  

Microsoft Academic Search

This paper evaluates strategies for atlas selection in atlas-based segmentation of three-dimensional biomedical images. Segmentation by intensity-based nonrigid registration to atlas images is applied to confocal microscopy images acquired from the brains of 20 bees. This paper evaluates and compares four different approaches for atlas image selection: registration to an individual atlas image (IND), registration to an average-shape atlas image

Torsten Rohlfing; Robert Brandt; Randolf Menzel; Calvin R. Maurer

2004-01-01

101

Multiphotonic Confocal Microscopy 3D imaging: Application to mantle sulfides in sub-arc environment (Avacha Volcano, Kamchatka)  

NASA Astrophysics Data System (ADS)

Petrogenetic relations in igneous rocks are usually studied in natural samples using classical optical microscopy and subsequent geochemical data acquisition. Multiphotonic Laser Scanning Confocal Microscopy (MLSCM) can be a powerful tool to section geological materials optically with sub-micrometric resolution and then generate a three-dimensional (3D) reconstruction (ca. 106 ?m3 stack). MLSCM is used here to investigate textural relations of Monosulfide Solid Solution (MSS) with silicate phases in fresh spinel harzburgite xenoliths from the andesitic Avacha volcano (Kamchatka, Russia). The xenoliths contain MSS disseminated in olivine and orthopyroxene (opx) neoblasts as well as MSS-rich quenched magmatic opx veins [1]. First, Reflection Mode (RM) was tested on vein sulfides in resin-impregnated thick (120 ?m) polished rock sections. Then we used a combination of Differential Interference Contrast (DIC) with a transmitted light detector, two photons-excited fluorescence (2PEF) and Second Harmonic Generation (SHG). Sequential imaging feature of the Leica TCS-SP2 software was applied. The excitation laser used for 2PEF was a COHERENT MIRA 900 with a 76Hz repetition rate and 800nm wavelength. Image stacks were analysed using ImageJ software [2]. The aim of the tests was to try to discriminate sulfides in silicate matrix as a tool for a better assessment of equilibrium conditions between the two phases. Preliminary results show that Fe-Ni rich MSS from vein and host rock have a strong auto-fluorescence in the Near UV-VIS domain (392-715 nm) whereas silicate matrix is only revealed through DIC. SHG is obtained only from dense nanocentrosymmetrical structures such as embedded medium (organic matter like glue and resin). The three images were recorded sequentially enabling efficient discrimination between the different components of the rock slices. RM permits reconstruction of the complete 3D structure of the rock slice. High resolution (ca. 0.2 ?m along X-Y axis vs. 0.4 along Z axis) 2PEF enables analysis of 3D textural relations of tiny individual MSS globules (˜10 ?m) in their various habitus. Statistical microgeometric descriptions can be derived from volumetric image data. These results may permit refinement of models concerning (re-) crystallisation kinetics and miscibility conditions of sulphur species in various media likely to act in different mantle environments: silicate melt, fluid-rich silicate melt, silicate-rich fluid. Furthermore, this study provides 3D images with improved resolution of several components (silicate phases, sulfides, silicate glass) over the full thickness (>100 ?m) of rock slices which cannot be done with classical methods. Besides 3D imaging of ‘hidden' phases in mantle rocks, it opens up new possibilities for other domains in geosciences like crystallography or petrophysics. [1] Bénard & Ionov (2010) GRA, this volume [2] Abramoff, M.D., Magelhaes, P.J. & Ram, S.J. (2004) Image processing with ImageJ. Biophoton. Int., 11, 36-42

Antoine, Bénard; Luc-Serge, Doucet; Sabine, Palle; Dmitri A., Ionov

2010-05-01

102

Confocal microscopy via a fiber optic imaging bundle  

NASA Astrophysics Data System (ADS)

The design of a confocal microscope including a fiber-optic imaging bundle is discussed, and experimental results are presented. The imaging bundle extends the range of the confocal microscope to image samples inaccessible to a conventional confocal system. The main advantage of this design over the single-fiber confocal microscope is the simplified mechanism required in the sample region. Applications of this design include biological research, industrial inspection, and potentially in-vivo medical systems.

Aziz, David J.; Gmitro, Arthur F.

1993-05-01

103

Confocal fluorescence microendoscopy of bronchial epithelium  

NASA Astrophysics Data System (ADS)

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.

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

2009-03-01

104

Confocal microscopy of hair  

Microsoft Academic Search

Confocal microscopy is an excellent method for studying the localization of fluorescent stains. Used in this way, superior 3D images can be obtained from multiple optical sections with very shallow depth of field. The main advantage of this technique is that the sample is not damaged. We have taken serial confocal sections of hair and via specific image enhancement routines

J. M. Lagarde; P. Peyre; D. Redoules; D. Black; M. Briot; Y. Gall

1994-01-01

105

Confocal microscopy on the Internet.  

PubMed

In a few short years, the Internet (in terms of the World Wide Web) has become a powerful informational resource for the original scientific literature pertaining to biological investigations using the laser scanning confocal microscope. However, there still remains an obvious void in the development of educational Web sites targeted at beginning students and novices in the field. Furthermore, many of the commercial aftermarket manufacturers (for example, those offering live-cell imaging chambers) have Web sites that are not adequately represented in published compilations, and are therefore somewhat difficult to locate. In order to address this issue, several educational sites dedicated to optical microscopy and digital imaging that are being constructed and hosted at The Florida State University are currently turning their attention to the increasing application of confocal microscopy in the biological and materials sciences. The primary focus of this effort is to create new sections on the existing sites that address the important educational issues in confocal microscopy, as well as creating indices of links to both the confocal scientific literature and the Web sites of manufacturers who supply useful accessories. PMID:24052347

Hazelwood, Kristin L; Murphy, Christopher S; Cunningham, Zachary C; Parry-Hill, Matthew J; Ludlow, Richard L; Ramko, Ericka B; Ozarowska, Anna P; Rainey, Adam M; Davidson, Michael W

2014-01-01

106

Confocal simultaneous phase-shifting interferometry  

SciTech Connect

In order to implement the ultraprecise measurement with large range and long working distance in confocal microscopy, confocal simultaneous phase-shifting interferometry (C-SPSI) has been presented. Four channel interference signals, with {pi}/2 phase shift between each other, are detected simultaneously in C-SPSI. The actual surface height is then calculated by combining the optical sectioning with the phase unwrapping in the main cycle of the interference phase response, and the main cycle is determined using the bipolar property of differential confocal microscopy. Experimental results showed that 1 nm of axial depth resolution was achieved for either low- or high-NA objective lenses. The reflectivity disturbance resistibility of C-SPSI was demonstrated by imaging a typical microcircuit specimen. C-SPSI breaks through the restriction of low NA on the axial depth resolution of confocal microscopy effectively.

Zhao Chenguang; Tan Jiubin; Tang Jianbo; Liu Tao; Liu Jian

2011-02-10

107

Spectral reflectance of selected aqueous solutions for water quality applications  

NASA Technical Reports Server (NTRS)

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.

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

1972-01-01

108

Reflectance of metallic indium for solar energy applications  

NASA Technical Reports Server (NTRS)

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.

Bouquet, F. L.; Hasegawa, T.

1984-01-01

109

Synthetic aperture confocal imaging  

Microsoft Academic Search

Confocal microscopy is a family of imaging techniques that employ focused patterned illumination and synchronized imaging to create cross-sectional views of 3D biological specimens. In this paper, we adapt confocal imaging to large-scale scenes by replacing the optical apertures used in microscopy with arrays of real or virtual video projectors and cameras. Our prototype implementation uses a video projector, a

Marc Levoy; Billy Chen; Vaibhav Vaish; Mark Horowitz; Ian McDowall; Mark T. Bolas

2004-01-01

110

Confocal Microscopy in Biopsy Proven Argyrosis  

PubMed Central

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

Guven Yilmaz, Suzan; Akalin, Taner; Egrilmez, Sait; Yagci, Ayse

2013-01-01

111

Application of confocal laser microscopy and three-dimensional Voronoi diagrams for volume and surface estimates of interphase chromosomes.  

PubMed

This study demonstrates the use of Voronoi tessellation procedures to obtain quantitative morphological data for chromosome territories in the cell nucleus. As a model system, chromosomes 7 and X were visualized in human female amniotic fluid cell nuclei by chromosomal in situ suppression hybridization with chromosome-specific composite probes. Light optical serial sections of 18 nuclei were obtained with a confocal scanning laser fluorescence microscope. A three-dimensional (3-D) tessellation of the image volumes defined by the stack of serial sections was then performed. For this purpose a Voronoi diagram, which consists of convex polyhedra structured in a graph environment, was built for each nucleus. The chromosome territories were extracted by applying the Delaunay graph, the dual of the Voronoi diagram, which describes the neighbourhood in the Voronoi diagram. The chromosome territories were then described by three morphological parameters, i.e. volume, surface area and a roundness factor (shape factor). The complete evaluation of a nucleus, including the calculation of the Voronoi diagram, 3-D visualization of extracted territories using computer graphic methods and parameterization was carried out on a Silicon Graphics workstation and was generally completed within 5 min. The geometric information obtained by this procedure revealed that both X- and 7-chromosome territories were similar in volume. Roundness factors indicated a pronounced variability in interphase shape for both pairs of chromosomes. Surface estimates showed a significant difference between the two X-territories but not between chromosome 7-territories. PMID:7714892

Eils, R; Bertin, E; Saracoglu, K; Rinke, B; Schröck, E; Parazza, F; Usson, Y; Robert-Nicoud, M; Stelzer, E H; Chassery, J M

1995-02-01

112

Shallow subsurface applications of high-resolution seismic reflection  

NASA Astrophysics Data System (ADS)

Shallow seismic reflection surveys have been applied to a wide variety of problems. For example, in many geologic settings, variations and discontinuities on the surface of bedrock can influence the transport and eventual fate of contaminants introduced at or near the ground surface. Using seismic methods to determine the nature and location of anomalous bedrock can be an essential component of hydrologic characterization. Shallow seismic surveys can also be used to detect earthquake faults and to image underground voids. During the early 1980s, the advent of digital engineering seismographs designed for shallow, high-resolution surveying spurred significant improvements in engineering and environmental reflection seismology. Commonly, shallow seismic reflection methods are used in conjunction with other geophysical and geological methods, supported by a well-planned drilling-verification effort. To the extent that seismic reflection, refraction, and surface-wave methods can constrain shallow stratigraphy, geologic structure, engineering properties, and relative permeability, these methods are useful in civil-engineering applications and in characterizing environmental sites. Case histories from Kansas, California, and Texas illustrate how seismic reflection can be used to map bedrock beneath alluvium at hazardous waste sites, detect abandoned coal mines, follow the top of the saturated zone during an alluvial aquifer pumping test, and map shallow faults that serve as contaminant flowpaths.

Steeples, Don

2002-11-01

113

An Enhanced Reflection Removal Technique and its Applications  

NASA Astrophysics Data System (ADS)

Electroacoustic transducers using piezoelectric materials are popular in various applications such as underwater acoustics, ultrasound, earthquakes and elastic wave propagations. Especially, they are widely used in non-destructive testing for ultrasonic or acoustic emission transducers. In general, they generate and receive waves through media to find meaningful targets or physical characteristics of materials. However, in most uses, the media are bounded with finite dimensions, therefore there are multiple transmitting paths reflected from the boundaries. Such reflections corrupt the principal path signal to be analyzed. To overcome this problem, gating technique to gate successively transmitting and receiving signals, in other words, tone-burst signal technique, is most representatively used. This basically isolates the direct signal before the arrival of reflected signals in the time domain, and therefore it is also described as time windowing or time-selective windowing techniques without loss of generality. These techniques have inherent overlap problems invoked by long pulse duration, especially slightly damped signals or low frequency waves. An enhancement technique of shortening the pulses by digital filtering is proposed and successively applied in practical uses. It can isolate the principal path signal from reflected signals. Thereafter the signal can be perfectly recovered after removing reflections.

Kwon, Hyu-Sang; Choi, Young-Chul; Park, Jin-Ho; Yoon, Doo-Byung

114

DMD-enabled confocal microendoscopy  

NASA Astrophysics Data System (ADS)

Conventional endoscopy is limited to imaging macroscopic views of tissue. The British Columbia Cancer Research Center, in collaboration with Digital Optical Imaging Corp., is developing a fiber-bundle based microendoscopy system to enable in vivo confocal imaging of cells and tissue structure through the biopsy channel of an endoscope, hypodermic needle, or catheter. The feasibility of imaging individual cells and tissue architecture will be presented using both reflectance and tissue auto-fluorescence modes of imaging. The system consists of a coherent fiber bundle, low-magnification high-NA objective lens, Digital Micromirror DeviceTM(DMD), light source, and CCD camera. The novel approach is the precise control and manipulation of light flow into and out of individual optical fibers. This control is achieved by employing a DMD to illuminate and detect light from selected fibers such that only the core of each fiber is illuminated or detected. The objective of the research is to develop a low-cost, clinically viable microendoscopy system for a range of detection, diagnostic, localization and differentiation uses associated with cancer and pre-cancerous conditions. Currently, multi-wavelength reflectance confocal images with 1 micrometers lateral resolution and 1.6 micrometers axial resolution have been achieved using a 0.95 mm bundle with 30,000 fibers.

Lane, Pierre M.; Dlugan, Andrew L. P.; MacAulay, Calum E.

2001-05-01

115

High-speed multispectral confocal biomedical imaging.  

PubMed

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

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

2014-03-01

116

The Noninvasive Retro-Mode Imaging Modality of Confocal Scanning Laser Ophthalmoscopy in Polypoidal Choroidal Vasculopathy: A Preliminary Application  

PubMed Central

Purpose To evaluate the validity of the novel and noninvasive retro-mode imaging modality of confocal scanning laser ophthalmoscopy (cSLO) for detecting the morphological features of polypoidal choroidal vasculopathy (PCV). Design Prospective, observational, consecutive case series. Methods Twenty-six patients (29 eyes) with PCV were enrolled in this study. All patients underwent comprehensive ophthalmologic examinations and imaging studies, including retro-mode imaging, fundus autofluorescence (FAF), fundus photography, fundus fluorescein angiography (FFA), indocyanine green angiography (ICGA) and spectral-domain optical coherence tomography (SD-OCT). We investigated the retro-mode images and compared the results with those of SD-OCT, FFA and ICGA. Results In the 29 PCV eyes, the retro-mode images clearly revealed polypoidal lesions in 27 (93.1%) eyes as well as branching vascular networks in 16 (55.2%) eyes. Others findings, including pigment epithelial detachment (PED) in 20 (69.0%) eyes, neuroretinal detachment (NRD) in 3 (10.3%) eyes, cystoid macular edema (CME) in 3 (10.3%) eyes, drusen in 4 (13.8%) eyes and minute granular changes of the retinal pigment epithelium (RPE) in 12 (41.3%) eyes, were also clearly visualized. When we compared the results with those of SD-OCT, FFA and ICGA, there was no significant difference between ICGA and retro-mode imaging for finding polypoidal lesions and (or) branching choroidal vascular networks (P>0.05). However, the rate of PED detection was significantly better with retro-mode imaging than with the ICGA (P<0.05). The differences were not statistically significant between SD-OCT and retro-mode imaging for detecting PED, NRD, CME, drusen and minute granular RPE changes (P>0.05). The differences were not statistically significant between FFA and retro-mode imaging for detecting PED, NRD, CME (P>0.05). Conclusions The novel and noninvasive retro-mode imaging by cSLO is able to clearly visualize the morphological features of PCV.

Zeng, Renpan; Zhang, Xiongze; Su, Yu; Li, Meng; Wu, Kunfang; Wen, Feng

2013-01-01

117

Reflection.  

PubMed

Reflection is thinking about practice, based on traces of recalled facts or data, with a view toward better understanding it. Reflection is prompted by discrepancies between what we observe and what we expect and commonly takes the forms of comparing personal experiences, reviewing events mentally, looking for trends in data, building new prototypes, and managing impressions. Normally, the process involves awareness, reviewing selected traces, resolving tensions, and looking for the greater whole. Practitioners both reflect in practice (specific problem solving) and reflect on practice (drawing general conclusions). The essence of reflection is finding a meaningful way to make tacit knowledge available in explicit form. Often this involves story telling, with its attendant features of plot, emotion, dramatic tension, and the success of the hero. PMID:16217940

Chambers, David W

2005-01-01

118

Re-scan confocal microscopy: scanning twice for better resolution  

PubMed Central

We present a new super-resolution technique, Re-scan Confocal Microscopy (RCM), based on standard confocal microscopy extended with an optical (re-scanning) unit that projects the image directly on a CCD-camera. This new microscope has improved lateral resolution and strongly improved sensitivity while maintaining the sectioning capability of a standard confocal microscope. This simple technology is typically useful for biological applications where the combination high-resolution and high-sensitivity is required.

De Luca, Giulia M.R.; Breedijk, Ronald M.P.; Brandt, Rick A.J.; Zeelenberg, Christiaan H.C.; de Jong, Babette E.; Timmermans, Wendy; Azar, Leila Nahidi; Hoebe, Ron A.; Stallinga, Sjoerd; Manders, Erik M.M.

2013-01-01

119

Confocal THz Laser Microscope  

Microsoft Academic Search

We transfer the principle of the optical confocal microscope to a far-field THz imaging system based on an optically pumped\\u000a gas laser emitting radiation at 2.52 THz. This results in a contrast enhancement. To illustrate the image quality improvement,\\u000a we show THz images of different objects taken with the suggested scheme and compare them to images taken with other systems.

Mohammed Adnan Salhi; Ioachim Pupeza; Martin Koch

2010-01-01

120

LASER SCANNING CONFOCAL MICROSCOPY  

Microsoft Academic Search

Laser scanning confocal microscopy has become an invaluable tool for a wide range of investigations in the biological and medical sciences for imaging thin optical sections in living and fixed specimens ranging in thickness up to 100 micrometers. Modern instruments are equipped with 3-5 laser systems controlled by high-speed acousto-optic tunable filters (AOTFs), which allow very precise regulation of wavelength

Nathan S. Claxton; Thomas J. Fellers; Michael W. Davidson

121

Reflection  

NSDL National Science Digital Library

In this activity, students learn that infrared light is reflected in the same manner as visible light. Students align a series of mirrors so that they can turn on a TV with a remote control when the remote is not in a direct line with the TV. As a result of their experiment with reflection, students deduce that infrared light is another form of light and is a part of the electromagnetic spectrum. Section 1 of the activity guide includes teacher notes, information on materials and preparation, student misconceptions and a student pre-test. Each activity section also includes teacher notes, student activity sheets, and answer keys. This activity requires a TV and remote control. It is the third of four activities in Active Astronomy, which are designed to complement instruction on the electromagnetic spectrum, focusing on infrared light.

122

The sociomoral reflection measure: applicability to Swedish children and adolescents.  

PubMed

The Sociomoral Reflection Measure (SRM; Gibbs & Widaman, 1982) was developed as a group administerable instrument for measuring developmental stages of moral reasoning. The aim of this study was to examine its reliability and construct validity, employing a sample of 542 Swedish elementary and high school students (aged 8-17), from schools within metropolitan Stockholm. Interrater reliability varied between 0.83 and 0.92, and the internal consistency coefficient was 0.76. Factor analyses of the norms (on which the overall score is based) revealed one factor for the oldest age group (16-17 years), but two factors among the younger subjects (8-15 years), clearly separating the norms related to each of the two moral dilemmas. The Sociomoral Reflection Maturity Score was moderately, but significantly, related to both age and grade. The results suggests that, although used in a non-American context and with self-trained raters, the SRM seems highly applicable in Sweden, at least for research purposes. PMID:2047796

Nilsson, I; Crafoord, J; Hedengren, M; Ekehammar, B

1991-01-01

123

Adaptive aberration correction in a confocal microscope  

PubMed Central

The main advantage of confocal microscopes over their conventional counterparts is their ability to optically “section” thick specimens; the thin image slices thus obtained can be used to reconstruct three-dimensional images, a capability which is particularly useful in biological applications. However, it is well known that the resolution and optical sectioning ability can be severely degraded by system or specimen-induced aberrations. The use of high aperture lenses further exacerbates the problem. Moreover, aberrations can considerably reduce the number of photons that reach the detector, leading to lower contrast. It is rather unfortunate, therefore, that in practical microscopy, aberration-free confocal imaging is rarely achieved. Adaptive optics systems, which have been used widely to correct aberrations in astronomy, offer a solution here but also present new challenges. The optical system and the source of aberrations in a confocal microscope are considerably different and require a novel approach to wavefront sensing. This method, based upon direct measurement of Zernike aberration modes, also exhibits an axial selectivity similar to that of a confocal microscope. We demonstrate an adaptive confocal fluorescence microscope incorporating this modal sensor together with a deformable membrane mirror for aberration correction. Aberration corrected images of biological specimens show considerable improvement in contrast and apparent restoration of axial resolution.

Booth, Martin J.; Neil, Mark A. A.; Juskaitis, Rimas; Wilson, Tony

2002-01-01

124

Automated analysis of spines from confocal laser microscopy images: application to the discrimination of androgen and estrogen effects on spinogenesis.  

PubMed

Accurate 3D determination of postsynaptic structures is essential to our understanding memory-related function and pathology in neurons. However, current methods of spine analysis require time-consuming and labor-intensive manual spine identification in large image data sets. Therefore, a realistic implementation of algorithm is necessary to replace manual identification. Here, we describe a new method for the automated detection of spines and dendrites based on analysis of geometrical features. Our "Spiso-3D" software carries out automated dendrite reconstruction and spine detection using both eigenvalue images and information of brightness, avoiding detection of pseudo-spines. To demonstrate the potential application of Spiso-3D automated analysis, we distinguished the rapid effects of androgen and estrogen on rapid modulation of spine head diameter in the hippocampus. These findings advance our understanding of neurotrophic function of brain sex steroids. Our method is expected to be valuable to analyze vast amounts of dendritic spines in neurons in the mammalian cerebral cortex. PMID:21527787

Mukai, Hideo; Hatanaka, Yusuke; Mitsuhashi, Kenji; Hojo, Yasushi; Komatsuzaki, Yoshimasa; Sato, Rei; Murakami, Gen; Kimoto, Tetsuya; Kawato, Suguru

2011-12-01

125

Bidirectional Reflectance Functions for Application to Earth Radiation Budget Studies  

NASA Technical Reports Server (NTRS)

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.

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

1997-01-01

126

Fluorophores for Confocal Microscopy: Photophysics and Photochemistry  

Microsoft Academic Search

\\u000a Fluorescence is probably the most important optical readout mode in biological confocal microscopy because it can be much\\u000a more sensitive and specific than absorbance or reflectance, and because it works well with epi-illumination, which greatly\\u000a simplifies scanner design. These advantages of fluorescence are critically dependent on suitable fluorophores that can be\\u000a tagged onto biological macromolecules to show their location, or

Roger Y. Tsien; Lauren Ernst; Alan Waggoner

127

Use of confocal microscopy for nanoparticle drug delivery through skin  

NASA Astrophysics Data System (ADS)

Confocal laser scanning microscopy (CLSM) is a well-used microscopic tool that provides valuable morphological and functional information within cells and tissues. The application of CLSM to skin and the topical penetration of nanoparticles (NP) will be addressed. First, we describe the advantages of confocal microscopy compared to other techniques and its use relative to skin research. Second, we discuss the ability of CLSM to detect single NP. Regarding their interaction with skin, the appropriate method to retain nanoparticle localization in the tissue with minimal fixation is critically important. Also, the interaction of several different types of NP (quantum dots, fullerene and dendrimers) and their interaction with skin detected by CLSM under various conditions (flexed, tape stripped and abraded skin) is reviewed. Finally, human epidermal keratinocytes and dendritic cells that serve as appropriate in vitro models for skin cell interactions and cellular uptake of NP are also discussed. In conclusion, the unique functions of CLSM such as the ability to detect fluorescence, optical sectioning, three dimensional remodeling, as well as its use in the reflection mode in tandem with other methods, provides great promise with broad applications regarding the interactions of nanomaterials with skin.

Zhang, Leshuai W.; Monteiro-Riviere, Nancy A.

2013-06-01

128

A simple submicron confocal microscope with a fiberoptic output  

Microsoft Academic Search

We present a simple design of a reflection-type confocal microscope with a multimode graded-index fiber output. Due to the use of an apertureless confocal arrangement, a high-aperture focusing objective and a large-core graded-index multimode fiber for signal detection, a regime of high-output power is achieved that provides high resolving power and submicron spatial resolution. The graded-index multimode fiber ensures an

Ilko K. Ilev; Ronald W. Waynant

2000-01-01

129

Confocal Microscopy of Corneal Dystrophies  

PubMed Central

In vivo confocal microscopy (IVCM) of the cornea is becoming an indispensable tool in the cellular study of corneal physiology and disease. This technique offers non-invasive imaging of the living cornea with images comparable to that of ex vivo histology. The ability to provide high-resolution images of all layers in the living cornea has resulted in new discoveries of corneal pathology at the cellular level. The IVCM analysis of corneal dystrophies is of importance to clinicians, as current methods of diagnosis involve slit-lamp characteristics, genetic analysis, and invasive biopsy. IVCM is helpful in evaluating the morphological characteristics of corneal dystrophies at the histological level and may be helpful in diagnosis, determination of progression, and understanding the pathophysiology of disease. The purpose of this review is to describe the principles, applications, and clinical correlation of IVCM in the study of corneal dystrophies.

Shukla, Anita N.; Cruzat, Andrea; Hamrah, Pedram

2014-01-01

130

Inhomogeneous polarization in confocal microscopy  

NASA Astrophysics Data System (ADS)

Cylindrical vector (CV) beams are single mode solutions to Maxwell's equations which are distinguished by their spatially inhomogeneous polarization, their vector symmetry about the direction of propagation, and an on-axis null (a phase vortex) which does not disappear with propagation. Any CV beam can be decomposed into a linear combination of radial and azimuthal polarization. This thesis explored the theoretical and experimental behavior of CV beams in both the paraxial and high angle focusing regimes, along with their possible applications in microscopy. The electric and magnetic fields of radially and azimuthally polarized beams in the paraxial regime are derived and incorporated, as a pupil apodization function, into the vector diffraction theory of Richards and Wolf. It is possible, in this way, to obtain expressions for the electric and magnetic fields of azimuthally and radially polarized beams in the focal region of a high numerical aperture lens. It is shown that radially polarized beams have a longitudinal electric field on axis that, at high numerical apertures, is significantly stronger near focus than the longitudinal field associated with uniformly polarized beams; additionally, azimuthally polarized beams have no longitudinal field component and have an annular focal region that maintains its purely transverse components in both focusing regimes. A theory of dark field confocal microscopy is formulated in order to predict the point spread function (PSF) of small dielectric particles illuminated by focused azimuthally or radially polarized light and imaged by a confocal microscope. Several experimental methods of CV beam formation are investigated and implemented in a scanning laser microscope. It is shown that the unique properties of focused CV beams may be applied to single molecule imaging, particle detection, and dark field imaging similar to that of DIC microscopy. Applications of particular interest include semiconductor inspection, lithography, and biomedical imaging.

Youngworth, Kathleen Sue

131

Confocal microscopy for healthy and pathological nail.  

PubMed

Nail diseases are often annoying for the patient and diagnostically challenging for dermatologists. New imaging techniques are of high interest in the diagnosis of nail disorders to reduce the number of nail biopsies. Confocal microscopy is a high-resolution emerging imaging technique that can be used to explore the entire body surface, including skin, mucosa, hair and nails. A systematic review of the literature concerning the use of confocal microscopy for the study of either healthy or pathological nail has been performed to evaluate the current use of this technique and possible future applications. Confocal microscopy is particularly suitable for nails because it allows a non-invasive in vivo examination of this sensitive body area, and nail plate transparency permits to image up to the nail bed with an easy identification of corneocytes. Confocal microscopy can play a role in the diagnosis of onychomycosis and melanonichia, and in the study of drug penetration through the nail plate. It could be used in the future as a non-invasive procedure for the investigation of different nail diseases, such as psoriasis and lichen planus. Further application could be the intra-operative ex vivo examination of nail specimens to outline tumour margins to assist surgery. PMID:24320009

Cinotti, E; Fouilloux, B; Perrot, J L; Labeille, B; Douchet, C; Cambazard, F

2014-07-01

132

Reflection-mode GaAs PMT for lidar applications  

NASA Astrophysics Data System (ADS)

BATC was contracted by Langley Research Center (LaRC) to design and fabricate a gallium arsenide photomultiplier tube (GaAs PMT) for LIDAR applications. This particular GaAs PMT uses a high strip current ceramic channel electron multiplier (CEM), manufactured by K&M electronics, capable of operating at a gain of 104 to 107. The GaAs photocathode, processed by Litton Electro-Optical Systems, is used in reflection mode so that light passes through a faceplate, strikes the photocathode and generates photoelectrons, which are collected and multiplied by the CEM. Key issues during the development of this device were; (1) increasing the CEM strip current, (2) improvements in the CEM collection efficiency, (3) processing of an opaque extended blue GaAs photocathode, (4) CEM and photocathode lifetime and (5) electron optic modeling. This paper will discuss the test results from the three functional GaAs PMTs fabricated during this effort as well as development and fabrications issues.

Argabright, Vic S.; Franka, Steven

1999-11-01

133

4Pi-confocal microscopy of live cells.  

PubMed

By coherently adding the spherical wavefronts of two opposing lenses, two-photon excitation 4Pi-confocal fluorescence microscopy has achieved three-dimensional imaging with an axial resolution 3-7 times better than confocal microscopy. So far this improvement was possible only in glycerol-mounted, fixed cells. Here we report 4Pi-confocal microscopy of watery objects and its application to the imaging of live cells. Water immersion of 4Pi-confocal microscopy of membrane stained live Escherichia coli bacteria attains a 4.3-fold better axial resolution as compared to the best water immersion confocal microscope. The resolution enhancement results into a vastly improved three-dimensional representation of the bacteria. The first images of live biological samples with an all-directional resolution in the 190-280 nm range are presented here, thus establishing a new resolution benchmark in live-cell microscopy. PMID:11330502

Bahlmann, K; Jakobs, S; Hell, S W

2001-04-01

134

Confocal coded aperture imaging  

DOEpatents

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.

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

2001-01-01

135

Confocal Imaging of porous media  

NASA Astrophysics Data System (ADS)

Carbonate rocks, which hold approximately 50% of the world's oil and gas reserves, have a very complicated and heterogeneous structure in comparison with sandstone reservoir rock. We present advances with different techniques to image, reconstruct, and characterize statistically the micro-geometry of carbonate pores. The main goal here is to develop a technique to obtain two dimensional and three dimensional images using Confocal Laser Scanning Microscopy. CLSM is used in epi-fluorescent imaging mode, allowing for the very high optical resolution of features well below 1?m size. Images of pore structures were captured using CLSM imaging where spaces in the carbonate samples were impregnated with a fluorescent, dyed epoxy-resin, and scanned in the x-y plane by a laser probe. We discuss the sample preparation in detail for Confocal Imaging to obtain sub-micron resolution images of heterogeneous carbonate rocks. We also discuss the technical and practical aspects of this imaging technique, including its advantages and limitation. We present several examples of this application, including studying pore geometry in carbonates, characterizing sub-resolution porosity in two dimensional images. We then describe approaches to extract statistical information about porosity using image processing and spatial correlation function. We have managed to obtain very low depth information in z -axis (~ 50?m) to develop three dimensional images of carbonate rocks with the current capabilities and limitation of CLSM technique. Hence, we have planned a novel technique to obtain higher depth information to obtain high three dimensional images with sub-micron resolution possible in the lateral and axial planes.

Shah, S.; Crawshaw, D.; Boek, D.

2012-12-01

136

Reflectance spectroscopy: quantitative analysis techniques for remote sensing applications.  

USGS Publications Warehouse

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

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

1984-01-01

137

Reflectance Spectroscopy: Quantitative Analysis Techniques for Remote Sensing Applications  

Microsoft Academic Search

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 optical path length and the implications for use in modeling reflectance spectra are presented. It is shown that the mean optical path length in a particulate

Roger N. Clark; Ted L. Roush

1984-01-01

138

Confocal microscopy of the cornea  

Microsoft Academic Search

This paper provides the clinician and the researcher with an in-depth manual on the use of a scanning-slit confocal light microscope for the clinical examination and investigation of the living human cornea in vivo. The scope of the paper includes a thorough explanation of the principles of various types of confocal microscopes as well as their limitations, a comprehensive review

Matthias Böhnke; Barry R Masters

1999-01-01

139

Application of AI techniques to infer vegetation characteristics from directional reflectance(s)  

NASA Technical Reports Server (NTRS)

Traditionally, the remote sensing community has relied totally on spectral knowledge to extract vegetation characteristics. However, there are other knowledge bases (KB's) that can be used to significantly improve the accuracy and robustness of inference techniques. Using AI (artificial intelligence) techniques a KB system (VEG) was developed that integrates input spectral measurements with diverse KB's. These KB's consist of data sets of directional reflectance measurements, knowledge from literature, and knowledge from experts which are combined into an intelligent and efficient system for making vegetation inferences. VEG accepts spectral data of an unknown target as input, determines the best techniques for inferring the desired vegetation characteristic(s), applies the techniques to the target data, and provides a rigorous estimate of the accuracy of the inference. VEG was developed to: infer spectral hemispherical reflectance from any combination of nadir and/or off-nadir view angles; infer percent ground cover from any combination of nadir and/or off-nadir view angles; infer unknown view angle(s) from known view angle(s) (known as view angle extension); and discriminate between user defined vegetation classes using spectral and directional reflectance relationships developed from an automated learning algorithm. The errors for these techniques were generally very good ranging between 2 to 15% (proportional root mean square). The system is designed to aid scientists in developing, testing, and applying new inference techniques using directional reflectance data.

Kimes, D. S.; Smith, J. A.; Harrison, P. A.; Harrison, P. R.

1994-01-01

140

Confocal endomicroscopy of colorectal polyps.  

PubMed

Confocal laser endomicroscopy (CLE) is one of several novel methods that provide real-time, high-resolution imaging at a micron scale via endoscopes. CLE has the potential to be a disruptive technology in that it can change the current algorithms that depend on biopsy to perform surveillance of high-risk conditions. Furthermore, it allows on-table decision making that has the potential to guide therapy in real time and reduce the need for repeated procedures. CLE and related technologies are often termed "virtual biopsy" as they simulate the images seen in traditional histology. However, the imaging of living tissue allows more than just pragmatic convenience; it also allows imaging of living tissue such as active capillary circulation, cellular death, and vascular and endothelial translocation, thus extending beyond what is capable in traditional biopsy. Immediate potential applications of CLE are to guide biopsy sampling in Barrett's esophagus and inflammatory bowel disease surveillance, evaluation of colorectal polyps, and intraductal imaging of the pancreas and bile duct. Data on these applications is rapidly emerging, and more is needed to clearly demonstrate the optimal applications of CLE. In this paper, we will focus on the role of CLE as applied to colorectal polyps detected during colonoscopy. PMID:22319524

Ussui, Vivian M; Wallace, Michael B

2012-01-01

141

Confocal Endomicroscopy of Colorectal Polyps  

PubMed Central

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

Ussui, Vivian M.; Wallace, Michael B.

2012-01-01

142

Polarization-based index of refraction and reflection angle estimation for remote sensing applications  

Microsoft Academic Search

A passive-polarization-based imaging system records the polarization state of light reflected by objects that are illuminated with an unpolarized and generally uncontrolled source. Such systems can be useful in many remote sensing applications including target detection, object segmentation, and material classification. We present a method to jointly estimate the complex index of refraction and the reflection angle (reflected zenith angle)

Vimal Thilak; David G. Voelz; Charles D. Creusere

2007-01-01

143

The role of confocal microscopy in the dermato-oncology practice  

PubMed Central

Reflectance–mode confocal microscopy (RCM) is a new in vivo skin imaging technique. We present our one–year experience in RCM examinations in skin tumors and the retrospective analysis of patients enrolled in the Dermatological Department of ‘N. Paulescu’ Institute using the Fotofinder Dermoscope II? for the dermatoscopy analysis and VivaScope 1500? for in vivo RCM. We established the rank of RCM in the complex algorithm of skin cancer diagnose, showing that the presented experience can open new possibilities to implement this automated image analyzing system in the routine practice. Our analyzed cases clearly showed that confocal microscopy, therefore, optical biopsy, could guide the clinician towards an accurate diagnosis before surgical removal. Moreover, we emphasized that the development of this technique increases the potential of future teledermatologic applications.

Boda, D; Neagu, M; Constantin, C; Caruntu, C; Vladau, L; Gutu, D

2011-01-01

144

Novel efficient methods for measuring mesophyll anatomical characteristics from fresh thick sections using stereology and confocal microscopy: application on acid rain-treated Norway spruce needles  

Microsoft Academic Search

Recent design-based stereological methods that can be applied to thick sections cut in an arbitrary direction are presented and their implementation for measuring mesophyll anatomical characteristics is introduced. These methods use software-randomized virtual 3D probes, such as disector and fakir test probes, in stacks of optical sections acquired using confocal microscopy. They enable unbiased estima- tions of the mean mesophyll

Jana Albrechtova ´; Zuzana Lhotakova ´; Barbora Radochova ´; Lucie Kubinova

2007-01-01

145

Application of photon recollision probability in coniferous canopy reflectance simulations  

Microsoft Academic Search

A new semi-physical forest reflectance model, PARAS, is presented in the paper. PARAS is a simple parameterization model for taking into account the effect of within-shoot scattering on coniferous canopy reflectance. Multiple scattering at the small scale represented by a shoot is a conifer-specific characteristic which causes the spectral signature of coniferous forests to differ from that of broadleaved forests.

Miina Rautiainen; Pauline Stenberg

2005-01-01

146

Diffuse reflection imaging at terahertz frequencies for security applications  

Microsoft Academic Search

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

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

2007-01-01

147

Comparison and applications to in vivo biology of two different methods of spectral imaging: confocal scanning full spectrum and global illumination spectral band-pass imaging  

NASA Astrophysics Data System (ADS)

With classical fluorescence microscopes, the sample is illuminated by a monochromatic source and the image is recorded through a bandpass filter that selects a portion of the emitted fluorescence. Recently, the spatial resolution and sensitivity of these devices have been considerably increased with the introduction of confocality and large 2D CCD array detectors and it is now possible to perform even 3D mapping of fluorescent markers in single living cells. Unfortunately, small changes occurring in fluorescence spectra cannot be mapped so easily. A set of colored filters is hardly enough even to separate slightly overlapping fluorescence contributions from multiple marking. The number of biological studies requiring a detailed description of fluorescence spectrum is growing continuously. Spectral changes are induced, for example, by environment (hydrophilic/hydrophobic binding), pH, oxygenation, ion concentration (Ca, Mg, Na), conformation of bound macromolecule (A/B DNA, protein folding), metabolism, dimerization of the probe, etc. . . . The classical approach to these problems is to couple a spectrograph to a microscope and obtain, point after point, a set of significative fluorescence spectra from the sample. This is a long procedure which gives incomplete information. We report in this paper on two methods we have developed to quickly record an array of spectra over the sample and to map spectral features such as bandwidth, maxima shifts, or decomposition in multiple overlapping components. We distinguish between the confocal scanning method and the global illumination (non confocal) method.

Valisa, P.; Sharonov, S.; Favard, C.; Herben, C.; Manfait, Michel; Vigny, Paul; da Silva, E.

1995-12-01

148

Reflection phase characterizations of the EBG ground plane for low profile wire antenna applications  

Microsoft Academic Search

Mushroom-like electromagnetic band-gap (EBG) structures exhibit unique electromagnetic properties that have led to a wide range of electromagnetic device applications. This paper focuses on the reflection phase feature of EBG surfaces: when plane waves normally illuminate an EBG structure, the phase of the reflected field changes continuously from 180° to -180° versus frequency. One important application of this feature is

Fan Yang; Yahya Rahmat-Samii

2003-01-01

149

High-speed multispectral confocal imaging  

NASA Astrophysics Data System (ADS)

A new approach for generating high-speed multispectral 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 concept 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.

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

2013-02-01

150

APPLICATIONS OF SEISMIC REFLECTION IN THE COAL ENVIRONMENT  

Microsoft Academic Search

Seismic reflection has grown to become a valuable geophysical tool for the accurate and cost- effective imaging of coal seams, and is now of significant importance to the economics and safety of coal mining in Australia. This paper provides an essential, up-to-date overview of the advantages and potential pitfalls of using the seismic method in the coal environment based on

Troy Peters; Natasha Hendrick

151

Shallow subsurface applications of high-resolution seismic reflection  

Microsoft Academic Search

Shallow seismic reflection surveys have been applied to a wide variety of problems. For example, in many geologic settings, variations and discontinuities on the surface of bedrock can influence the transport and eventual fate of contaminants introduced at or near the ground surface. Using seismic methods to determine the nature and location of anomalous bedrock can be an essential component

Don Steeples

2002-01-01

152

A New Multichannel Spectral Imaging Laser Scanning Confocal Microscope  

PubMed Central

We have developed a new multichannel spectral imaging laser scanning confocal microscope for effective detection of multiple fluorescent labeling in the research of biological tissues. In this paper, the design and key technologies of the system are introduced. Representative results on confocal imaging, 3-dimensional sectioning imaging, and spectral imaging are demonstrated. The results indicated that the system is applicable to multiple fluorescent labeling in biological experiments.

Zhang, Yunhai; Hu, Bian; Dai, Yakang; Yang, Haomin; Huang, Wei; Xue, Xiaojun; Li, Fazhi; Zhang, Xin; Jiang, Chenyu; Gao, Fei; Chang, Jian

2013-01-01

153

Combined Confocal and Magnetic Resonance Microscopy  

SciTech Connect

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.

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

154

Optical tweezers for confocal microscopy  

NASA Astrophysics Data System (ADS)

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

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

2000-11-01

155

Application of multispectral reflectance for early detection of tomato disease  

NASA Astrophysics Data System (ADS)

Automatic diagnosis of plant disease is important for plant management and environmental preservation in the future. The objective of this study is to use multispectral reflectance measurements to make an early discrimination between the healthy and infected plants by the strain of tobacco mosaic virus (TMV-U1) infection. There were reflectance changes in the visible (VIS) and near infrared spectroscopy (NIR) between the healthy and infected plants. Discriminant models were developed using discriminant partial least squares (DPLS) and Mahalanobis distance (MD). The DPLS models had a root mean square error of calibration (RMSEC) of 0.397 and correlation coefficient (r) of 0.59 and the MD model correctly classified 86.7% healthy plants and up to 91.7% infected plants.

Xu, Huirong; Zhu, Shengpan; Ying, Yibin; Jiang, Huanyu

2006-10-01

156

Multiple-reflection optical gas cell. [DOE Patent Application  

DOEpatents

A multiple-reflection optical cell for Raman or fluorescence gas analysis consists of two spherical mirrors positioned transverse to a multiple-pass laser cell in a confronting plane-parallel alignment. The two mirrors are of equal diameter but possess different radii of curvature. The spacing between the mirrors is uniform and less than half of the radius of curvature of either mirror. The mirror of greater curvature possesses a small circular portal in its center which is the effective point source for conventional Fl double lens collection optics of a monochromator-detection system. Gas to be analyzed is flowed into the cell and irradiated by a multiply-reflected composite laser beam centered between the mirrors of the cell. Raman or fluorescence radiation originating from a large volume within the cell is: (1) collected via multiple reflections with the cell mirrors; (2) partially collimated; and (3) directed through the cell portal in a geometric array compatible with Fl collection optics.

Matthews, T.G.

1981-06-15

157

Rapid observation of unfixed, unstained human skin biopsy specimens with confocal microscopy and visualization  

NASA Astrophysics Data System (ADS)

The use of reflected light confocal microscopy is proposed to rapidly observe unfixed, unstained biopsy specimens of human skin. Reflected light laser scanning confocal microscopy was used to compare a freshly excised, unfixed, unstained biopsy specimen, and in vivo human skin. Optical sections from the ex vivo biopsy specimen of human skin and in vivo human skin were converted to red-green anaglyphs for 3D visualization. Contrast was derived from intrinsic differences in the scattering properties of the organelles and cells within the tissue. Individual cellular layers were observed in both tissues from the surface to the papillary dermis. Confocal microscopy of an unfixed, unstained biopsy specimen showed cells and cell nuclei of the stratum spinosum. Confocal microscopy of in vivo human skin demonstrated optical sectioning through a hair shaft on the upper hand. The combination of reflected light confocal microscopy and 3D visualization with red-green anaglyphs provides a rapid technique for observing fresh biopsies of human skin.

Masters, Barry R.; Aziz, David J.; Gmitro, Arthur F.; Kerr, James H.; O'Grady, Terence C.; Goldman, Leon

1997-10-01

158

Dendrimers in biomedical applications—reflections on the field  

Microsoft Academic Search

The formation of particulate systems with well-defined sizes and shapes is of eminent interest in certain medical applications such as drug delivery, gene transfection, and imaging. The high level of control possible over the architectural design of dendrimers; their size, shape, branching length\\/density, and their surface functionality, clearly distinguishes these structures as unique and optimum carriers in those applications. The

Sönke Svenson; Donald A. Tomalia

2005-01-01

159

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

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…

Chou, Pao-Nan; Chang, Chi-Cheng

2011-01-01

160

Confocal Microscopy for Real Time Detection of Oral Cavity Neoplasia.  

National Technical Information Service (NTIS)

The goal of this study was to characterize features of normal and neoplastic oral mucosa using reflectance confocal microscopy. Oral cavity biopsies were acquired from 17 patients at the Head and Neck Clinic of the University of Texas M. D. Anderson Cance...

A. L. Clark A. Gillenwater T. Collier R. Alizadeh-Naderi A. K. El-Naggar

2003-01-01

161

Micromechanical scanning mirrors with highly reflective NIR coatings for high-power applications  

NASA Astrophysics Data System (ADS)

This paper addresses different highly reflective optical coatings on micro scanning mirrors (MSM) for applications in the NIR-spectral region to enable new applications like laser marking and material treatment at high optical power density. In the case of MSM with an unprotected Al coating, the absorption limits the maximal power density because of induced heating. The damage threshold for unprotected Al coatings was investigated. In addition highly reflective enhanced metallic and dielectric multilayer coatings for the NIR have been developed and characterized. These coatings resolve the problems of unprotected aluminum coatings related to NIR absorption and the resulting limitation of applicable laser power density. The coatings ensure a high reflectance even in corrosive environments. Enhanced metallic broadband reflectors reach a reflectivity of 98.7% at 1064 nm whereas narrow-band dielectric multilayer coatings reach a reflectivity of 99.7% at 1064 nm.

Sandner, Thilo; Schmidt, Jan U.; Schenk, Harald; Lakner, Hubert; Braun, Stefan; Foltyn, Thomas; Leson, Andreas; Gatto, Alexandre; Yang, Minghong; Kaiser, Norbert

2005-01-01

162

Methods of creating solar-reflective nonwhite surfaces and their application to residential roofing materials  

Microsoft Academic Search

We describe methods for creating solar-reflective nonwhite surfaces and their application to a wide variety of residential roofing materials, including metal, clay tile, concrete tile, wood, and asphalt shingle. Reflectance in the near-infrared (NIR) spectrum (0.7–2.5?m) is maximized by coloring a topcoat with pigments that weakly absorb and (optionally) strongly backscatter NIR radiation, and by adding an NIR-reflective basecoat (e.g.,

Ronnen Levinson; Paul Berdahl; Hashem Akbari; William Miller; Ingo Joedicke; Joseph Reilly; Yoshi Suzuki; Michelle Vondran

2007-01-01

163

Methods of Creating Solar-Reflective Nonwhite Surfaces and theirApplication to Residential Roofing Materials  

Microsoft Academic Search

We describe methods for creating solar-reflective nonwhitesurfaces and their application to a wide variety of residential roofingmaterials, including metal, clay tile, concrete tile, wood, and asphaltshingle. Reflectance in the near-infrared (NIR) spectrum (0.7 2.5mu m) ismaximized by coloring a topcoatwith pigments that weakly absorb and(optionally) strongly backscatter NIR radiation, and adding anNIR-reflective basecoat (e.g., titanium dioxide white) if both thetopcoat

Ronnen Levinson; Paul Berdahl; Hashem Akbari; William Miller; Ingo Joedicke; Joseph Reilly; Yoshi Suzuki; Michelle Vondran

2005-01-01

164

Quantitative confocal phase imaging by synthetic optical holography.  

PubMed

We demonstrate quantitative phase mapping in confocal optical microscopy by applying synthetic optical holography (SOH), a recently introduced method for technically simple and fast phase imaging in scanning optical microscopy. SOH is implemented in a confocal microscope by simply adding a linearly moving reference mirror to the microscope setup, which generates a synthetic reference wave analogous to the plane reference wave of wide-field off-axis holography. We demonstrate that SOH confocal microscopy allows for non-contact surface profiling with sub-nanometer depth resolution. As an application for biological imaging, we apply SOH confocal microscopy to map the surface profile of an onion cell, revealing nanoscale-height features on the cell surface. PMID:24977617

Schnell, M; Perez-Roldan, M J; Carney, P S; Hillenbrand, R

2014-06-16

165

anti-reflective films for solar cell applications  

NASA Astrophysics Data System (ADS)

Indium tin oxide (ITO) and titanium dioxide (TiO2) anti-reflective coatings (ARCs) were deposited on a (100) P-type monocrystalline Si substrate by a radio-frequency (RF) magnetron sputtering. Polycrystalline ITO and anatase TiO2 films were obtained at room temperature (RT). The thickness of ITO (60 to 64 nm) and TiO2 (55 to 60 nm) films was optimized, considering the optical response in the 400- to 1,000-nm wavelength range. The deposited films were characterized by X-ray diffraction (XRD), Raman spectroscopy, field emission scanning electron microscopy (FESEM), energy dispersive spectroscopy (EDS), and atomic force microscopy (AFM). The XRD analysis showed preferential orientation along (211) and (222) for ITO and (200) and (211) for TiO2 films. The XRD analysis showed that crystalline ITO/TiO2 films could be formed at RT. The crystallite strain measurements showed compressive strain for ITO and TiO2 films. The measured average optical reflectance was about 12% and 10% for the ITO and TiO2 ARCs, respectively.

Ali, Khuram; Khan, Sohail A.; Jafri, Mohd Zubir Mat

2014-04-01

166

Reflectance-Correcting Pyrometry in Thin Film Deposition Applications  

SciTech Connect

A detailed study of an emissivity-correcting pyrometer instrument for measuring wafer surface temperatures during thin film growth is presented. The basic physics is reviewed and preliminary data showing a temperature over-compensation artifact is shown. The rest of the report presents an exhaustive analysis of the potential sources for the temperature over-compensation effect. This analysis yields an in situ calibration method that can be used to remove temperature over-compensation artifacts that arise from any first-order systematic error in either the reflectance or thermal emission measurement. With corrections applied, artifact-free surface temperatures can be measured with a precision of a few {sup o}C over a wide range of wafer emissivities.

BREILAND, WILLIAM G.

2003-06-01

167

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

SciTech Connect

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).

Suckewer, S.

1998-07-01

168

A method to optimize illumination optical systems with application of total internal reflection  

NASA Astrophysics Data System (ADS)

The methods of optimization for illumination optical systems with application of Total Internal Reflection are considered. The problem of optimization includes: a) the optimal values of the angles for reflecting triangles in order to have maximum efficiency; b) the calculations of the angles for the case of both primary light (from the bulb) and secondary light (from the reflector). Developed methods can be applicable for automotive lamps, aviation lighting and any other illumination systems.

Berger, Valeriy K.

2003-11-01

169

Custom-made modification of a commercial confocal microscope to photolyze caged compounds using the conventional illumination module and its application to the observation of Inositol 1,4,5-trisphosphate-mediated calcium signals  

NASA Astrophysics Data System (ADS)

The flash photolysis of ``caged'' compounds is a powerful experimental technique for producing rapid changes in concentrations of bioactive signaling molecules. These caged compounds are inactive and become active when illuminated with ultraviolet light. This paper describes an inexpensive adaptation of an Olympus confocal microscope that uses as source of ultraviolet light the mercury lamp that comes with the microscope for conventional fluorescence microscopy. The ultraviolet illumination from the lamp (350 - 400 nm) enters through an optical fiber that is coupled to a nonconventional port of the microscope. The modification allows to perform the photolysis of caged compounds over wide areas (~200 ?m) and obtain confocal fluorescence images simultaneously. By controlling the ultraviolet illumination exposure time and intensity it is possible to regulate the amount of photolyzed compounds. In the paper we characterize the properties of the system and show its capabilities with experiments done in aqueous solution and in Xenopus Laevis oocytes. The latter demonstrate its applicability for the study of Inositol 1,4,5-trisphosphate-mediated intracellular calcium signals.

Sigaut, Lorena; Barella, Mariano; Espada, Rocío; Ponce, María Laura; Dawson, Silvina Ponce

2011-06-01

170

Chromatic confocal spectral interferometry for technical surface characterization  

NASA Astrophysics Data System (ADS)

Chromatic confocal spectral interferometry (CCSI) is a hybrid method for fast topography measurement, which combines the advantages of the interferometric gain and accuracy with the robustness of confocal microscopy. The CCSI-principle provides a single shot measurement of depth while offering a higher lateral resolution than commonly used spectral interferometers. This contribution is focused on the modeling and simulation of a CCSI-sensor for measuring rough surfaces, based on sequential and non-sequential ray-tracing. With the simulation, the influence of surface roughness, surface reflectivity, and surface contamination on reliability of the sensor can be estimated.

Lyda, W.; Fleischle, D.; Haist, T.; Osten, W.

2009-08-01

171

Reflection-mode GaAs PMT for lidar applications  

Microsoft Academic Search

BATC was contracted by Langley Research Center (LaRC) to design and fabricate a gallium arsenide photomultiplier tube (GaAs PMT) for LIDAR applications. This particular GaAs PMT uses a high strip current ceramic channel electron multiplier (CEM), manufactured by K&M electronics, capable of operating at a gain of 104 to 107. The GaAs photocathode, processed by Litton Electro-Optical Systems, is used

Vic S. Argabright; Steven Franka

1999-01-01

172

Hybrid hyperchromats for chromatic confocal sensor systems  

NASA Astrophysics Data System (ADS)

The combination of diffractive and refractive elements in hybrid optical systems allows for precise control of the longitudinal chromatic aberration. We provide comprehensive design strategies for hybrid hyperchromatic lenses that maximise the longitudinal chromatic aberrations. These lenses are mainly used in chromatic confocal sensor systems for efficient non-contact profilometry as well as for measurements of distances and wall thicknesses of transparent materials. Our design approach enables the tailoring of the sensor properties to the specific measurement problem and assists designers in finding optimised solutions for industrial applications. We, for example, demonstrate a hybrid system that significantly exceeds the longitudinal chromatic aberration of purely diffractive elements.

Hillenbrand, Matthias; Mitschunas, Beate; Wenzel, Christian; Grewe, Adrian; Ma, Xuan; Feßer, Patrick; Bichra, Mohamed; Sinzinger, Stefan

2012-07-01

173

Optical Electronic Bragg Reflection Sensor System with Hydrodynamic Flow Applications  

NASA Technical Reports Server (NTRS)

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.

Lyons, D. R.

2003-01-01

174

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...

175

Micromechanical scanning mirrors with highly reflective NIR coatings for high-power applications  

Microsoft Academic Search

This paper addresses different highly reflective optical coatings on micro scanning mirrors (MSM) for applications in the NIR-spectral region to enable new applications like laser marking and material treatment at high optical power density. In the case of MSM with an unprotected Al coating, the absorption limits the maximal power density because of induced heating. The damage threshold for unprotected

Thilo Sandner; Jan U. Schmidt; Harald Schenk; Hubert Lakner; Stefan Braun; Thomas Foltyn; Andreas Leson; Alexandre Gatto; Minghong Yang; Norbert Kaiser

2005-01-01

176

Novel efficient methods for measuring mesophyll anatomical characteristics from fresh thick sections using stereology and confocal microscopy: application on acid rain-treated Norway spruce needles.  

PubMed

Recent design-based stereological methods that can be applied to thick sections cut in an arbitrary direction are presented and their implementation for measuring mesophyll anatomical characteristics is introduced. These methods use software-randomized virtual 3D probes, such as disector and fakir test probes, in stacks of optical sections acquired using confocal microscopy. They enable unbiased estimations of the mean mesophyll cell volume, mesophyll cell number in a needle, and for the first time an internal surface area of needles or other narrow leaves directly from the fresh tissue cross-sections cut using a hand microtome. Therefore, reliable results can be obtained much faster than when using a standard microtechnical preparation. The proposed methods were tested on Norway spruce needles affected for 1 year by acid rain treatment. The effect of acid rain resulted in changes of mesophyll parameters: the ratio of intercellular spaces per mesophyll cell volume increased, while needle internal surface area, total number of mesophyll cells, and number of mesophyll cells per unit volume of a needle decreased in the treated needles. PMID:17322549

Albrechtová, Jana; Janácek, Jirí; Lhotáková, Zuzana; Radochová, Barbora; Kubínová, Lucie

2007-01-01

177

In Vivo Confocal Intrinsic Optical Signal Identification of Localized Retinal Dysfunction  

PubMed Central

Purpose. The purposes of this study were to investigate the physiological mechanism of stimulus-evoked fast intrinsic optical signals (IOSs) recorded in dynamic confocal imaging of the retina, and to demonstrate the feasibility of in vivo confocal IOS mapping of localized retinal dysfunctions. Methods. A rapid line-scan confocal ophthalmoscope was constructed to achieve in vivo confocal IOS imaging of frog (Rana pipiens) retinas at cellular resolution. In order to investigate the physiological mechanism of confocal IOS, comparative IOS and electroretinography (ERG) measurements were made using normal frog eyes activated by variable-intensity stimuli. A dynamic spatiotemporal filtering algorithm was developed to reject the contamination of hemodynamic changes on fast IOS recording. Laser-injured frog eyes were employed to test the potential of confocal IOS mapping of localized retinal dysfunctions. Results. Comparative IOS and ERG experiments revealed a close correlation between the confocal IOS and retinal ERG, particularly the ERG a-wave, which has been widely used to evaluate photoreceptor function. IOS imaging of laser-injured frog eyes indicated that the confocal IOS could unambiguously detect localized (30 ?m) functional lesions in the retina before a morphological abnormality is detectable. Conclusions. The confocal IOS predominantly results from retinal photoreceptors, and can be used to map localized photoreceptor lesion in laser-injured frog eyes. We anticipate that confocal IOS imaging can provide applications in early detection of age-related macular degeneration, retinitis pigmentosa, and other retinal diseases that can cause pathological changes in the photoreceptors.

Zhang, Qiu-Xiang; Lu, Rong-Wen; Curcio, Christine A.; Yao, Xin-Cheng

2012-01-01

178

High-power reflection coefficient measurement of biological material applicable to microwave hyperthermia  

Microsoft Academic Search

A measurement method for the high-power reflection coefficients of biological material applicable to microwave hyperthermia is presented. To extract the power-dependent complex permittivities, scalar S-parameter measurement setup consisting of a planar coaxial probe, impedance tuner, directional couplers, and power meters have been used. The tuner impedance was tuned until the reflected power reading was zeroed out, and subsequent de-embedding steps

Namgon Kim; Jeonghoon Yoon; Changyul Cheon; Youngwoo Kwon

2009-01-01

179

Automated cellular pathology in noninvasive confocal microscopy  

NASA Astrophysics Data System (ADS)

A computer algorithm was developed to automatically identify and count melanocytes and keratinocytes in 3D reflectance confocal microscopy (RCM) images of the skin. Computerized pathology increases our understanding and enables prevention of superficial spreading melanoma (SSM). Machine learning involved looking at the images to measure the size of cells through a 2-D Fourier transform and developing an appropriate mask with the erf() function to model the cells. Implementation involved processing the images to identify cells whose image segments provided the least difference when subtracted from the mask. With further simplification of the algorithm, the program may be directly implemented on the RCM images to indicate the presence of keratinocytes in seconds and to quantify the keratinocytes size in the en face plane as a function of depth. Using this system, the algorithm can identify any irregularities in maturation and differentiation of keratinocytes, thereby signaling the possible presence of cancer.

Ting, Monica; Krueger, James; Gareau, Daniel

2014-03-01

180

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

PubMed Central

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.

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

2012-01-01

181

Simple method for modeling radar reflections in a homogeneous halfspace, with applications  

NASA Astrophysics Data System (ADS)

We have developed a method to rapidly compute synthetic radar records from complex reflecting surfaces. The approach is a 3- D time domain Hemholtz-Kirchhoff (HK) representation, similar to Hilterman (1981), that includes the radiation characteristics of GPR dipoles on the surface of a uniform dielectric halfspace. Validity is established by making comparisons with published model results and by comparisons with field data. Comparison to the ray theory results of Zeng et al. (1997) show excellent agreement in reflection arrival times for pipes of various diameters. We also reproduce the non-specular reflection results of Schleicher et al. (1991), which show that large amplitude reflections can originate from the inflection points of curved surfaces. Our comparisons with field data use reflection records taken at a test site in Borden, Ontario, over horizontally oriented buried metal drums. The H-plane reflection data were collected using shielded 700-MHz dipoles. Our raw synthetic amplitude trends show reasonable agreement to the field data, but are not perfect. Using a small diameter synthetic dipole array, we show that the mismatch is most likely caused by antenna shielding effects. The versatility of the HK method is demonstrated by giving results for a number of interesting applications. These include synthetic records for crisscrossing pipes buried at various depths, reflection synthetics from a truncated cone representing the slag heaps in Daniels and Brower (1998), and reflections from a rough surface. The slag heap models demonstrate the effect of antenna polarization on reflections from sloping surfaces. Analysis of synthetic reflections from rough surfaces shows that the coda following the first impulsive arrival can be used to estimate the surface roughness. This is of interest for interpreting reflections from glacier data. Our results demonstrate that the HK method is useful in interpreting data, as well as for developing field survey strategies.

Greenfield, Roy J.; Moran, Mark L.; Davis, J. L.

2000-04-01

182

Confocal microscopy in a case of crystalline keratopathy in a patient with smouldering multiple myeloma.  

PubMed

We report the clinical and confocal microscopic findings of the cornea in a patient with smouldering multiple myeloma (SMM) using in vivo scanning laser confocal microscopy. A 72-year-old female underwent a complete ophthalmological examination including slit-lamp biomicroscopy with digital photography, HRT II laser scanning in vivo confocal microscopy and haematological laboratory assessment. Corneal biomicroscopy revealed the presence of bilateral diffuse microgranular tiny grey opacities. In vivo confocal microscopy showed randomly oriented hyper-reflective needle-shaped crystals throughout all levels of the stroma, sparing epithelium and endothelium. In vivo confocal microscopy was very helpful in the differential diagnosis by allowing the nature of the corneal deposits to be established, revealing the typical aspect of the crystals, and excluding granular dystrophy, leading to a suspected diagnosis of SMM. Crystalline corneal deposits may easily be confused as crumb-like opacities typical of granular dystrophy on slit-lamp examination even by experienced ophthalmologists. PMID:23928943

Mazzotta, Cosimo; Caragiuli, Stefano; Caporossi, Aldo

2014-06-01

183

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

PubMed Central

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.

Wang, Wen; He, Shitang

2008-01-01

184

Studies of stability of petroleum emulsions by confocal microscopy  

NASA Astrophysics Data System (ADS)

Developments of techniques such as confocal microscopy are been of great interest for the petroleum industry. Confocal images permits through of direct observation, obtain the acquisition and interpretation of in situ information of the petroleum emulsions systems, without requirement of sample pretreatments and can be applied to samples of high optical density as crude oils. This property of the confocal technique is of great utility for studies of the colloidal structural evolution in dark samples as asphaltenes, and water in crude oils emulsions. In this work, the applicability of a homemade confocal microscope is shown. Studies of stability of colloidal suspensions (asphaltenes and emulsions) such as aggregation kinetic, flocculation dynamic, and characterization of colloidal system are showed by confocal images. The aggregation process of flocculated asphaltenes for Furrial crude oils was showed through of high-resolution micrographics image, and their colloidal structural evolution are described by an analysis of size distribution of flocculated asphaltenes particles. Additional, the images of the dynamics in the drop size and drop size distributions during the initial stage of the separation of water drops from Furrial crude oils were also reported. This technique directly permitted for example, visualization of the coalescence of small droplets to form large ones from water-in-crude oil emulsions and visualize the morphology of flocculated asphaltenes.

Hung, J.; Castillo, J.

2006-11-01

185

Differential confocal technology based on radial birefringent pupil filtering principle  

NASA Astrophysics Data System (ADS)

In order to improve the spatial resolution of a confocal system, a radial birefringent pupil filter (RBPF) is introduced into a differential confocal system. RBPF consists of two polarizers with a birefringent element between them, and its pupil function is deduced from Jones matrix. The thickness and curvature radius of RBPF are optimized independently, using the first zero coordinate ratio. The pupil function is modulated by RBPF to enhance the half-width of the response function, and lateral resolution is improved when response curve is changed with the position of RBPF as well as the polarization; then axial super-resolution of the system can be guaranteed using differential confocal detection mechanism. In comparison with conventional pupil filtering technology, RBPF features high lateral resolution and can be easily produced; moreover, it also has a simple structure. Together with its low cost, RBPF provides a new way for the improvement of super-resolution of confocal system. It is indicated from theoretical analysis and preliminary experiments that the lateral resolution can be significantly improved and the measurement error is reduced by 76 nm when measuring a standard grating of period 3 ?m; the axial resolution up to 3 nm has been achieved using the optimized pupil filter. In addition to its application for measurement of a small irregular surface in a limited space, the whole differential confocal system proposed can be fitted onto a coordinate measuring machine for non-contact measurement of dimensions and surface roughness.

Zou, Limin; Qu, Jianqi; Hou, Siliang; Ding, Xuemei

2012-04-01

186

Simplified confocal microscope for counting particles at low concentrations  

PubMed Central

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.

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

2013-01-01

187

Simplified confocal microscope for counting particles at low concentrations.  

PubMed

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. PMID:23902088

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

2013-07-01

188

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

NASA Technical Reports Server (NTRS)

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.

Angus, J. C.

1979-01-01

189

TOTAL INTERNAL REFLECTION WITH FLUORESCENCE CORRELATION SPECTROSCOPY: APPLICATIONS TO SUBSTRATE-SUPPORTED PLANAR MEMBRANES  

PubMed Central

In this review paper, the conceptual basis and experimental design of total internal reflection with fluorescence correlation spectroscopy (TIR-FCS) is described. The few applications to date of TIR-FCS to supported membranes are discussed, in addition to a variety of applications not directly involving supported membranes. Methods related, but not technically equivalent, to TIR-FCS are also summarized. Future directions for TIR-FCS are outlined.

Thompson, Nancy L.; Wang, Xiang; Navaratnarajah, Punya

2009-01-01

190

A Recommended Engineering Application of the Method for Evaluating the Visual Significance of Reflected Glare.  

ERIC Educational Resources Information Center

An application method for evaluating the visual significance of reflected glare is described, based upon a number of decisions with respect to the relative importance of various aspects of visual performance. A standardized procedure for evaluating the overall effectiveness of lighting from photometric data on materials or installations is needed…

Blackwell, H. Richard

1963-01-01

191

Visible and near-infrared reflectivity of solid and liquid methane: application to spectroscopy of Titan's hydrocarbon lakes  

NASA Astrophysics Data System (ADS)

Reflectance spectroscopy provides one of the few direct observations of outer solar system bodies for interpreting their surface compositions. At Titan, the Visual and Infrared Mapping Spectrometer (VIMS) on board the Cassini spacecraft revealed dark patches on the surface through the narrow 2 and 5 ?m windows of Titan's atmosphere, which have been interpreted as hydrocarbon lakes forming seasonally through a methane cycle. Whereas the composition of planetary materials in the solar system has been inferred from characteristic absorption bands, the need to identify phase states (liquid versus solid) on dynamic planetary surfaces requires laboratory reflectance ratio measurements at relevant temperatures. Using visible and near-infrared radiation from the National Synchrotron Light Source (NSLS), we will present confocal reflectance ratio measurements of solid (single crystal) and liquid CH4 at temperatures from 50-100 K. Although the position and shape of the six characteristic methane absorption bands at around 1.7 and 2.3 ?m are insensitive to temperature or phase state from 50-100 K, the broad-spectrum reflectance between 0.5-2 ?m decreases upon melting by about 25% at 87-94 K. Transition from solid CH4-I to liquid states at ~90 K displays a reflectance ratio (sold/liquid) of about 1.3 at 2 ?m. Darkening of CH4 upon melting is similar at visible wavelengths, and consistent with VIMS observations of hydrocarbon lakes in the far northern and southern latitudes of Titan.

Adams, K.; Jacobsen, S. D.; Liu, Z.; Somayazulu, M.; Thomas, S.; Jurdy, D. M.

2011-12-01

192

Intravital Confocal and Two-photon Imaging of Dual-color Cells and Extracellular Matrix Mimics  

PubMed Central

To optimize imaging of cells in three dimensional culture we studied confocal backscattering, Second Harmonic Generation (SHG) and autofluorescence as source of contrast in extracellular matrix (ECM) mimics and evaluated the attenuation as well as bleaching of endogenous cellular fluorescence signals. All common ECM mimics exhibit contrast observable with confocal reflectance microscopy. SHG imaging on collagen I based hydrogels provides high contrast and good optical penetration depth. Agarose is a useful embedding medium because it allows for large optical penetration and exhibits minimal autofluorescence while still providing good reflectance to detect voids in the embedding medium. We labeled breast cancer cells’ outline with DsRed2 and nucleus with eGFP. DsRed2 can be excited with confocal imaging at 568nm, and with two photon excitation (TPE) in the red and longer NIR. eGFP was excited at 488nm for confocal and in the NIR for TPE. While there is small difference in the bleaching rate for eGFP between confocal and TPE we observed significant difference for DsRed2 where bleaching is strongest during TPE in the red wavelengths and smallest during confocal imaging. After a few hundred microns depth in a collagen I hydrogel, TPE fluorescence becomes twice as strong compared to confocal imaging.

Bal, Ufuk; Andresen, Volker; Baggett, Brenda; Utzinger, Urs

2013-01-01

193

Combined confocal Raman and quantitative phase microscopy system for biomedical diagnosis  

PubMed Central

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 chemical information from the sample, while confocal reflectance and quantitative phase microscopy show detailed morphology. Combining these intrinsic contrast imaging modalities makes it possible to obtain quantitative morphological and chemical information without exogenous staining. For validation and characterization, we have used this multi-modal system to investigate healthy and diseased blood samples. We first show that the thickness of a healthy red blood cell (RBC) shows good correlation with its hemoglobin distribution. Further, in malaria infected RBCs, we successfully image the distribution of hemozoin (malaria pigment) inside the cell. Our observations lead us to propose morphological screening by QPM and subsequent chemical imaging by Raman for investigating blood disorders. This new approach allows monitoring cell development and cell-drug interactions with minimal perturbation of the biological system of interest.

Kang, Jeon Woong; Lue, Niyom; Kong, Chae-Ryon; Barman, Ishan; Dingari, Narahara C.; Goldfless, Stephen J.; Niles, Jacquin C.; Dasari, Ramachandra R.; Feld, Michael S.

2011-01-01

194

Automated Confocal Microscope Bias Correction  

NASA Astrophysics Data System (ADS)

Illumination artifacts systematically occur in 2D cross-section confocal microscopy imaging . These bias can strongly corrupt an higher level image processing such as a segmentation, a fluorescence evaluation or even a pattern extraction/recognition. This paper presents a new fully automated bias correction methodology based on large image database preprocessing. This method is very appropriate to the High Content Screening (HCS), method dedicated to drugs discovery. Our method assumes that the amount of pictures available is large enough to allow a reliable statistical computation of an average bias image. A relevant segmentation evaluation protocol and experimental results validate our correction algorithm by outperforming object extraction on non corrupted images.

Dorval, Thierry; Genovesio, Auguste

2006-10-01

195

Video-Rate Confocal Scanning Laser Microscope for Imaging Human Tissues In Vivo  

Microsoft Academic Search

We have built a video-rate confocal scanning laser microscope for reflectance imaging of human skin and oral mucosa {ital in vivo}. Design and imaging parameters were determined for optimum resolution and contrast. Mechanical skin-holding fixtures and oral tissue clamps were made for stable objective lens-to-tissue contact such that gross tissue motion relative to the microscope was minimized. Confocal imaging was

Milind Rajadhyaksha; R. Rox Anderson; Robert H. Webb

1999-01-01

196

Confocal Microscopy in the Esophagus and Stomach  

PubMed Central

Probe-based confocal microscopy (pCLE) is actively being investigated for applications in the esophagus and stomach. The use of pCLE allows real-time in vivo microscopy to evaluate the microarchitecture of the mucosal epithelium. pCLE appears to be particularly useful in identifying mucosal dysplasia and early malignancies that cannot be clearly distinguished using high-definition white light endoscopy, chromoendoscopy, or magnification endoscopy. In addition, the ability to detect dysplastic tissue in real-time may shift the current screening practice from random biopsy to targeted biopsy of esophageal and gastric cancers and their precursor lesions. We will review the use of pCLE for detection and surveillance of upper gastrointestinal early luminal malignancy.

Templeton, Adam

2013-01-01

197

Confocal imaging through an endoscopic rod  

NASA Astrophysics Data System (ADS)

Endoscopic rods (such as the Hopkins variety) are based on a tubular design containing a sequence of refractive optical structures1. They are intended to offer a wide angle of view but often at the expense of performance in terms of field curvature. They are used in areas of biomedicine that require visualisation of live tissue at the distal end, enabling clinicians to perform a variety of endoscopy procedures including biopsy. Here we demonstrate a scanning confocal arrangement with the endoscopic rod used as an optical conduit, guiding the investigation beam to a resolution target placed at the distal end and guiding the backscattered light back to the detector. The data presented in this study highlights the possible new contributions of this method to aid Optical Coherence Tomography (OCT) measurements in vivo and what could be expected of its application in terms of scanangle (field of view) and transmission performance.

Galloway, Matt; Gabriel, Kayla; Dobre, George

2014-01-01

198

Broadband receiver response from dual-streamer data and applications in deep reflection seismology  

SciTech Connect

A method to process dual-streamer data with under and over configuration is presented. The method combines the results of dephase-sum and dephase-subtraction methods. In the dephase methods, the response of one streamer is time shifted so that the primary arrivals on both streamers are aligned, and these responses are then summed or subtracted. The method provides a broad spectral response from dual-streamer data and increases the signal-to-noise ratio by a factor of 1.5. Testing was done on synthetic data and then applied to a real data set collected by the British Institutions Reflection Profiling Syndicate (BIRPS). Its application to a deep seismic reflection data set from the British Isles shows that the reflections from the lower crust contain frequencies up to 80 Hz, suggesting that some of the lower crustal reflectors may have sharp boundaries and could be 20--30 m thick.

Singh, S.C.; Hobbs, R.W.; Snyder, D.B. [Univ. of Cambridge (United Kingdom)] [Univ. of Cambridge (United Kingdom)

1996-01-01

199

Object-depending artifacts in confocal measurements  

NASA Astrophysics Data System (ADS)

Confocal sensors are well established in optical surface metrology. Especially when measuring rough surfaces, their robustness is widely appreciated. However, it was shown lately that certain object features can produce severe artifacts in confocal measurements that are hard to identify as false measurements. Experimental evidence of these artifacts is given with a measurement of a suitable surface conducted with a chromatic confocal point sensor. Furthermore various simulations are presented that identify a self-imaging property of the surface features as the root of the artifacts. These simulations also pave the way to a more precise yet still intuitive signal model for confocal measurements.

Mauch, F.; Lyda, W.; Gronle, M.; Osten, W.

2012-10-01

200

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...

201

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

Microsoft Academic Search

Structures and functions of cell membranes are of central importance in understanding processes such as cell signaling, chemotaxis,\\u000a redox transformation, biofilm formation, and mineralization occurring at interfaces. This chapter provides an overview of\\u000a the application of neutron reflectivity (NR) as a unique tool for probing biomolecular structures and mechanisms as a first\\u000a step toward understanding protein–protein, protein–lipid, and protein–mineral interactions

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

2009-01-01

202

Total-Internal-Reflection Platforms for Chemical and Biological Sensing Applications  

Microsoft Academic Search

\\u000a Sensing platforms based on the principle of total internal reflection (TIR) represent a fairly mature yet still expanding\\u000a and exciting field of research. Sensor development has mainly been driven by the need for rapid, stand-alone, automated devices\\u000a for application in the fields of clinical diagnosis and screening, food and water safety, environmental monitoring, and chemical\\u000a and biological warfare agent detection.

Kim E. Sapsford

203

Multimodal confocal mosaicing microscopy: an emphasis on squamous cell carcinoma  

NASA Astrophysics Data System (ADS)

Our previous study reported a sensitivity of 96.6% and a specificity of 89.2% in rapidly detecting Basal Cell Carcinomas (BCCs) when nuclei were stained with acridine orange. Squamous Cell Carcinomas (SCCs) and infiltrative BCCs remain difficult to detect. More complete screening can be achieved utilizing both acridine orange for nuclei staining and eosin for cytoplasmic contrast, using two lasers to excite the two stains independently. Nuclear fluorescence is achieved by staining with acridine orange (0.5mM, 60 s), and cytoplasmic fluorescence is achieved by staining with eosin working solution (30 s). This work shows good morphological contrast of SCC and infiltrative BCC with eosin, acridine orange, and reflectance, and presents a means for rapid SCC and infiltrative BCC detection in fresh skin excisions using multimodal confocal microscopy. In addition, digital staining is shown to effectively simulate hematoxylin and eosin (H&E) histology with confocal mosaics.

Chen, Nathaniel W.; Sensibaugh, Jordan; Ardeshiri, Ardaland; Blanchard, Adam; Jacques, Steven; Gareau, Daniel

2010-02-01

204

Clinical feasibility of rapid confocal melanoma feature detection  

NASA Astrophysics Data System (ADS)

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.

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

2010-02-01

205

Confocal Microscope Alignment of Nanocrystals for Coherent Diffraction Imaging  

SciTech Connect

We have installed and tested an Olympus LEXT confocal microscope at the 34-ID-C beamline of the Advanced Photon Source (APS). The beamline is for Coherent X-ray Diffraction (CXD) experiments in which a nanometre-sized crystal is aligned inside a focussed X-ray beam. The microscope was required for three-dimensional (3D) sample alignment to get around sphere-of-confusion issues when locating Bragg peaks in reciprocal space. In this way, and by use of strategic sample preparations, we have succeeded in measuring six Bragg peaks from a single 200 nm gold crystal and obtained six projections of its internal displacement field. This enables the clear identification of stacking-fault bands within the crystal. The confocal alignment method will allow a full determination of the strain tensor provided three or more Bragg reflections from the same crystal are found.

Beitra, Loren; Watari, Moyu; Matsuura, Takashi [London Centre for Nanotechnology, University College, 17-19 Gordon Street, London, WC1H 0AH (United Kingdom); Shimamoto, Naonobu [Waseda University, Tokyo (Japan); Harder, Ross [Advanced Photon Source, Argonne, Illinois 60439 (United States); Robinson, Ian [London Centre for Nanotechnology, University College, 17-19 Gordon Street, London, WC1H 0AH (United Kingdom); Diamond Light Source, Harwell Campus, Didcot, Oxfordshire, OX11 0DE (United Kingdom)

2010-06-23

206

What is the confocal parameter?  

NASA Astrophysics Data System (ADS)

A novel derivation is presented of the Gaussian beam as a limit of the solution to the full wave equation. Usually, the functional form of the Gaussian beam is found by a two-step process. First, the Green's function of the paraxial wave equation is identified. Then, since the paraxial wave equation is invariant under translation, the z-axis variable is replaced by z + jb. It is shown that when starting with a solution of the full three-dimensional Helmholtz equation in spherical coordinates, performing the transformation z to z + jb corresponds physically to causing the phase fronts of the solution to become ellipsoids. The separation of the foci of the ellipsoids is 2b, where b is the confocal parameter of the beam. In the paraxial limit the ellipsoidal solution becomes a Gaussian beam. Adopting this approach to Gaussian beams allows a simple, geometrical interpretation of the optical resonator stability criterion.

Brorson, Stuart D.

1988-03-01

207

Confocal imaging of butterfly tissue.  

PubMed

To understand the molecular events responsible for morphological change requires the ability to examine gene expression in a wide range of organisms in addition to model systems to determine how the differences in gene expression correlate with phenotypic differences. There are approximately 12,000 species of butterflies, most, with distinct patterns on their wings. The most important tool for studying gene expression in butterflies is confocal imaging of butterfly tissue by indirect immunofluorescence using either cross-reactive antibodies from closely related species such as Drosophila or developing butterfly-specific antibodies. In this report, we describe how indirect immunofluorescence protocols can be used to visualize protein expression patterns on the butterfly wing imaginal disc and butterfly embryo. PMID:24052351

Brunetti, Craig R

2014-01-01

208

Performance of dual axes confocal microscope for in vivo molecular and cellular imaging  

NASA Astrophysics Data System (ADS)

The application of conventional confocal microscopes with high numerical aperture (NA) to in vivo imaging is limited by the objectiveís large physical dimensions and short working distance. We are developing a confocal microscope that uses simple low NA lenses oriented in a dual axes configuration for miniaturization and in vivo imaging. This architecture achieves a long working distance, micron level axial resolution, and reduced noise from scattered light outside the focal volume. Combined with the novel method of post-objective scanning, this design can be scaled down to millimeter dimensions. We derive the dual axes response from diffraction theory, and construct two tabletop prototypes to demonstrate the performance of this approach. We collect images from freshly excised biopsy specimens of human esophagus and transgenic mouse cerebellum expressing GFP. With horizontal cross-sectional images, we achieve 1 to 2 ?m resolution and collect reflectance and fluorescence images. With vertical cross-sectional images, we achieve 4 to 5 ?m resolution, dynamic range of 70 dB, and tissue penetration over 1 mm. An instrument miniaturized with this configuration could be used for in vivo cellular and molecular imaging.

Kino, Gordon S.; Wang, Thomas D.; Contag, Chris H.; Mandella, Michael; Chan, Ning Y.

2004-07-01

209

On the use of GPR energetic reflection coefficients in glaciological applications  

NASA Astrophysics Data System (ADS)

In this paper we analyse the suitability of Ground-Penetrating Radar (GPR) energetic reflection coefficients for glaciological applications, with focus on glacier hydrology. Standard coefficients such as the internal reflection power (IRP) and bedrock reflection power (BRP), or normalised versions of them, are first analysed in order to point out their weaknesses. Alternative versions of them, such as the internal reflection energy (IRE) or the bedrock reflection maximum (BRM), or normalised versions of them, are then introduced, aimed at overcoming the weaknesses of the standard definitions. Examples are shown using field data from radiophysical investigations made at Hansbreen, a polythermal glacier in Spitsbergen, in July-August 2003 and in April 2004. These investigations, aimed at studying the glacier hydrology, included repeated radar profiling (20 and 25 MHz) along a transverse profile, repeated common mid-point measurements, continuous radar measurements during 8 days at a fixed site, meteorological observations, and continuous ice surface velocity monitoring by differential GPS. The repeated GPR profiles are interpreted in terms of variations in the amount of water at the ice-bed interface, and also in terms of variations of melting at the ice surface, which decreases the power transmitted into the ice. The spatial variations of the internal reflection coefficients correlate with the changes in thickness of the cold ice layer and the occurrence of a drainage and crevasse systems. The comparison of internal and bedrock coefficients allow us to suggest different styles of hydraulic connection of either isolated crevasses, or complex moulin and crevasse systems, with the underlying bedrock. A good hydraulic connection between surface and bed seems to be responsible for the increase in basal sliding, and thus surface velocity, immediately following high surface melting events.

Navarro, F. J.; Lapazaran, J. J.; Machío, F.; Martín, C.; Otero, J.

2009-04-01

210

Confocal Unstable-Resonator Semiconductor Laser.  

National Technical Information Service (NTIS)

GaAs/GaA1As 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 nea...

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

1986-01-01

211

Confocal microscopy in the iridocorneal endothelial syndrome  

Microsoft Academic Search

AIMSTo report the appearances of iridocorneal endothelial (ICE) syndrome from real time, white light confocal microscopy.METHODSThree consecutive patients, each with ICE syndrome, were examined prospectively. Corneal specular and confocal microscopic examinations were performed in all three patients. In the first patient, a penetrating keratoplasty was performed and the cornea was examined by light and scanning electron microscopy. No surgery was

Auguste G-Y Chiou; Stephen C Kaufman; Roger W Beuerman; Toshihiko Ohta; Volkan Yaylali; Herbert E Kaufman

1999-01-01

212

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...

213

In vivo 783-channel diffuse reflectance imaging system and its application  

NASA Astrophysics Data System (ADS)

A fiber-based reflectance imaging system was constructed to produce in vivo absorption spectroscopic images of biological tissues with diffuse light in the cw domain. The principal part of this system is the 783-channel fiber probe, composed of 253 illumination fibers and 530 detection fibers distributed in a 20×20 mm square region. During illumination with the 253 illumination fibers, diffuse reflected lights are collected by the 530 detection fibers and recorded simultaneously as an image with an electron multiplying CCD camera for fast data acquisition. After signal acquisition, a diffuse reflectance image was reconstructed by applying the spectral normalization method we devised. To test the applicability of the spectral normalization, we conducted two phantom experiments with chicken breast tissue and white Delrin resin by using animal blood as an optical inhomogeneity. In the Delrin phantom experiment, we present images produced by two methods, spectral normalization and reference signal normalization, along with a comparison of the two. To show the feasibility of our system for biomedical applications, we took images of a human vein in vivo with the spectral normalization method.

Yang, Joon-Mo; Han, Yong-Hui; Yoon, Gilwon; Ahn, Byung Soo; Lee, Byung-Cheon; Soh, Kwang-Sup

2007-08-01

214

Large Area Microencapsulated Reflective Guest-Host Liquid Crystal Displays and Their Applications  

NASA Astrophysics Data System (ADS)

We have developed reflective liquid crystal displays using microencapsulated guest-host liquid crystals, whose size was sufficiently large for viewing documents. A high-brightness image can be realized because there is no need for polarizers. Easy fabrication processes, consisting of screen-printing of microencapsulated liquid crystal and film adhesion, have enabled the realization of thinner and lighter cell structures. It has been confirmed that the display is tolerant of the pressures to which it would be subject in actual use. The optimization of fabrication processes has enabled the realization of reflectance uniformity in the display area and reduction of the driving voltage. Our developed display is suitable for portable information systems, such as electronic book applications.

Nakai, Yutaka; Tanaka, Masao; Enomoto, Shintaro; Iwanaga, Hiroki; Hotta, Aira; Kobayashi, Hitoshi; Oka, Toshiyuki; Kizaki, Yukio; Kidzu, Yuko; Naito, Katsuyuki

2002-07-01

215

Detection of forests using mid-IR reflectance: An application for aerosol studies  

SciTech Connect

The detection of dark, dense vegetation is an important step in the remote sensing of aerosol loading. Current methods that employ the red (0.64 [mu]m) and the near-IR (0.84 [mu]m) regions are unsatisfactory in that the presence of aerosols in the scene distorts the apparent reflectance in the visible and near-IR ranges of the spectrum. The mid-IR spectral region is also sensitive to vegetation due to the absorption of liquid water in the foliage, but is not sensitive to the presence of most aerosols (except for dust). Therefore, mid-IR channels on the AVHRR and EOS-MODIS (e.g., the 3.75 [mu]m or the 3.95 [mu]m channels) have a unique potential for the remote sensing of dark, dense vegetation, particularly in the presence of biomass burning smoke or industrial/urban haze. The reflective part of the 3.75 [mu]m channel ([rho][sub 3.75]) is applied to images of the AVHRR over the eastern US. This channel was found to be correlated to reflectance at 0.64 [mu]m ([rho][sub 0.64]), less sensitive to haze than the visible channel and superior to both the 0.64 [mu]m reflectance and the normalized difference vegetation index (NDVI) to determine forest pixels in an image. However, its application to monitor the seasonal evolution of vegetation is presently questionable. For the purpose of the remote sensing of aerosol over dark, dense vegetation, it is proposed that the dark, dense vegetation be determined from [rho][sub 3.75] < 0.025. These findings may have further implications for other specific applications of the remote sensing of vegetation in hazy atmospheres.

Kaufman, Y.J. (National Aeronautics and Space Administration, Greenbelt, MD (United States). Goddard Space Flight Center); Remer, L.A. (Science Systems and Applications Inc., Lanham, MD (United States))

1994-05-01

216

Confocal UV and resonance Raman microscopic imaging of pharmaceutical products.  

PubMed

Chemical imaging using confocal Raman microscopy is a useful analytical tool in drug development because of its ability to spatially image active ingredients and excipients in dosage forms and relate their distribution to product performance. While Raman spectra are highly specific for individual components of a formulation, most Raman microscopic mapping experiments require extensive experimental time. Laser wavelengths in the near-infrared range are used to suppress fluorescence but reduce sensitivity because of the inverse quadratic dependence of Raman scattering on laser wavelength. Compact, simple ultraviolet (UV) laser designs now allow for confocal UV Raman microscopy to be performed using a versatile instrument also capable of conventional Raman microscopy and epifluorescence imaging analyses. This study presents the results of UV Raman microscopy analyses using 266 nm laser irradiation of four pharmaceutical compositions of interest, including two types of tablets containing low doses of active ingredients (in the 0.2% w/w range), an amorphous dispersion containing 1% w/w of a small molecule drug, and an enteric coated layered peptide formulation. Resonance Raman enhancements are observed for four of the active ingredients studied in these formulations. The spectroscopic properties of the materials used in this study are also assessed by diffuse reflectance UV-visible spectroscopy, fluorescence spectroscopy, and conventional bulk Fourier transform Raman spectroscopy using 1064 nm laser irradiation. Confocal UV Raman microscopy was found to offer good sensitivity and allowed for rapid microscopic mapping of drugs and excipients at low concentrations in pharmaceutical formulations. PMID:24050305

Vogt, Frederick G; Strohmeier, Mark

2013-11-01

217

Chromatic confocal microscope using hybrid aspheric diffractive lenses  

NASA Astrophysics Data System (ADS)

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.

Rayer, Mathieu; Mansfield, Daniel

2014-05-01

218

Multiple reflection and attenuation of time domain reflectometry pulses: Theoretical considerations for applications to soil and water  

Microsoft Academic Search

The application of time domain reflectometry (TDR) to determine soil water content, using only the time axis of a TDR trace, has been widely investigated. Other interpretations from the TDR trace, such as the determination of electrical conductivity, make use of the amplitude or reflection coefficient values. These latter interpretations must take account of multiple reflections in the media. A

M. Yanuka; G. C. Topp; S. Zegelin; W. D. Zebchuk

1988-01-01

219

Photometric Phase Functions of Common Geologic Minerals and Applications to Quantitative Analysis of Mineral Mixture Reflectance Spectra  

Microsoft Academic Search

Hapke's model for bidirectional reflectance is used to calculate the mass fractional abundance of compo- nents in intimately mixed, particulate surfaces from laboratory reflectance spectra. Application of this model, simplified by the assumptions that all surfaces scatter light with the same constant phase function and the opposition surge is negligible, to binary mineral mixtures are summarized and compared with new

John F. Mustard; Carlé M. Pieters

1989-01-01

220

Rapid line-scan confocal imaging of retinal activation  

NASA Astrophysics Data System (ADS)

A rapid line-scan confocal imager was developed for reflected light measurement of fast IOSs correlated with retinal activation. This functional imager provides two, i.e., frame-by-frame and line-by-line, imaging modalities. While frame-by-frame imaging allows dynamic visualization of IOSs over a two-dimensional retinal area at a frame speed > 100 Hz; line-by-line recording can provide ultrafast (> 10 KHz) monitoring of a fixed line area of the retina. A series of experiments was conducted to characterize reflected IOSs in frog retinas, and simultaneous electrophysiological responses were measured. Our experiments indicated that reflected IOSs were tightly correlated with retinal stimuli. Because of effective rejection of out-of-focus background light, rapid confocal imaging typically disclosed fast IOSs with magnitude peak > 30% ?I/I, where ?I was dynamic optical change and I was background light intensity. We anticipate that further development of the IOS imaging technology will pave the way toward noninvasive, high resolution evaluation of retinal function.

Li, Yang-Guo; Yao, Xin-Cheng

2010-02-01

221

[Application of near-infrared reflectance spectroscopy in grass breeding with space flight mutagenesis].  

PubMed

Near infrared reflectance spectroscopy is a new fast and efficient analysis method. It has been wildly used in many areas such as evaluation of feedstuff, assessment of soil fertilizer and so on. In the present paper, the principle, technique method and merits of NIRS were introduced. The potential application of NIRS in grass breeding with space flight mutagenesis was discussed in areas such as analysis of grass nutrition, estimate of secondary metabolism compounds, forecast of disease and insects resistance, and evaluation of abiotic stress. The conclusion is that application of NIRS in grass breeding with space mutagenesis is significant in both academic and technical areas because it not only improves the efficiency of mutation selection but helps uncover the mechanism of space mutation breeding. PMID:18479009

Ren, Wei-Bo; Han, Jian-Guo; Zhang, Yun-Wei; Guo, Hui-Qin

2008-02-01

222

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...

223

X-ray fluorescence microtomography- and polycapillary-based confocal imaging using synchrotron radiation  

Microsoft Academic Search

This work illustrates the development of X-ray fluorescence tomography and polycapillary based confocal imaging towards a three-dimensional (3D), quantitative analytical method with lateral resolution levels down to the 2-20 mum scale. Detailed analytical characterization is given for polycapillary based confocal XRF imaging, which is a new variant of the 3D micro-XRF technique. Applications for 2D\\/3D micro-XRF are illustrated for the

Laszlo Vincze; Bart Vekemans; Imre Szaloki; Frank E. Brenker; Gerald Falkenberg; Karen Rickers; Katrien Aerts; Rene Van Grieken; Freddy Adams

2004-01-01

224

Confocal laser scanning microscopy. Using new technology to answer old questions in forensic investigations  

Microsoft Academic Search

Confocal laser scanning microscopy (CLSM) is a relatively new technique for microscopic imaging. It has found a wide field\\u000a of application in the general sphere of biological sciences. It has completely changed the study of cells and tissues by allowing\\u000a greater resolution, optical sectioning of the sample and three-dimensional sanoke reconstruction. Confocal microscopy represents\\u000a a valid, precious and useful tool

Emanuela Turillazzi; Steven B. Karch; Margherita Neri; Cristoforo Pomara; Irene Riezzo; Vittorio Fineschi

2008-01-01

225

Confocal unstable-resonator semiconductor laser  

NASA Technical Reports Server (NTRS)

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.

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

1986-01-01

226

Confocal microscopy of skin cancers: Translational advances toward clinical utility  

PubMed Central

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.

Rajadhyaksha, Milind

2014-01-01

227

Confocal Raman spectroscopy of whole hairs.  

PubMed

This paper describes the application of Raman spectroscopy to whole hair fibers. Previously this has proved difficult because the hairs are relatively opaque, and spatial resolution diminishes with depth because of the change in refractive index. A solution is to couple confocal Raman with multivariate curve resolution (MCR) data analysis, which separates spectral differences with depth despite this reduction in resolution. Initially, it is shown that the cuticle can be separated from the cortex, showing the differences in the proteins, which can then be plotted as a function of depth, with the cuticle factor being seen only at the surface as expected. Hairs that had been treated in different ways, e.g., by bleaching, treatment with the active molecule resorcinol followed by rinsing and treatment with a full hair care product, were also examined. In all cases, changes to the hair are identified and are associated with specific parts of the fiber. Since the hair fiber is kept intact, it can be repeatedly treated and measured, hence multistep treatment processes can be followed. This method expands the potential use of Raman spectroscopy in hair research. PMID:24359655

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

2013-12-01

228

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

NASA Astrophysics Data System (ADS)

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.

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

2004-10-01

229

Integrating professionalism in early medical education: the theory and application of reflective practice in the anatomy curriculum.  

PubMed

Renewed emphases on teaching professionalism require physicians to develop the ability to critically reflect upon their own decisions. Innovative programs that address teaching professionalism within medical curricula have been implemented in almost all medical schools. The foundation for many of these programs is "reflection," which is regarded as a core skill in professional competence. In order to achieve the desired outcomes and meet the demands of a required curriculum, an understanding of educational concepts in the designing of medical curricula is essential. Educators recognize that, for most medical students, professional growth is initiated during the first year of the medical curriculum and, therefore, traditionally pure content delivery courses such as first year anatomy course are being utilized now in order to explore issues related to critical thinking and professionalism. As a result, learning strategies such as "reflective practice" are beginning to play an important role in curriculum design. This article provides an overview of the theory of reflective practice, and demonstrates how reflective practice may be integrated into the anatomy curriculum. In order to incorporate reflective exercises into a curriculum, the basic elements of a reflective process are defined, strategies to implement reflective exercises within the course are described, and the benefits of reflective practice are highlighted. Therefore, in creating an environment that fosters reflective learning, the gap between theory and practice may be consolidated, which in the context of anatomy promotes the issue of teaching for relevance and clinical application. PMID:16683241

Lachman, Nirusha; Pawlina, Wojciech

2006-07-01

230

Study on continuous-wave THz confocal scanning image restoration  

Microsoft Academic Search

Terahertz (THz) confocal scanning imaging is a combination of confocal scanning microscope and THz imaging, which could effectively improve the imaging resolution of the imaging system. The size of the confocal pinholes has a great influence on the system's resolution. When the confocal pinholes are removed from the optical path, blurred imaging results are obtained. Lucy-Richardson method is applied to

Sheng-Hui Ding; Qi Li; Rui Yao; Qi Wang

2010-01-01

231

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

SciTech Connect

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.

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

2011-03-14

232

Plane-wave reflection from uniaxial chiral interface and its application to polarization transformation  

Microsoft Academic Search

Plane-wave reflection and transmission in a planar interface between air and an axially chiral uniaxial medium whose axis is parallel to the interface is considered in the present study. By finding the reflection dyadic and its eigensolutions, we demonstrate that by dimensioning the uniaxial medium in a proper way, it is possible to make a reflection-transforming reflecting surface. The surface

Ismo V. Lindell; Ari Henrik Sihvola

1995-01-01

233

Allergic contact dermatitis: Correlation of in vivo confocal imaging to routine histology  

Microsoft Academic Search

Background: Allergic contact dermatitis (ACD) is a common and often challenging clinical problem. In vivo near-infrared confocal reflectance microscopy (CM) is a new vital microscopy technique. Objective: CM was used to evaluate acute ACD. Methods: Patch testing by means of Finn Chambers technique was performed in 5 subjects to induce an acute allergic skin reaction. Noninvasive CM images from normal

Salvador González; Ernesto González; W. Matthew White; Milind Rajadhyaksha; R. Rox Anderson

1999-01-01

234

Confocal microwave imaging for breast cancer detection: localization of tumors in three dimensions  

Microsoft Academic Search

The physical basis for breast tumor detection with microwave imaging is the contrast in dielectric properties of normal and malignant breast tissues. Confocal microwave imaging involves illuminating the breast with an ultra-wideband pulse from a number of antenna locations, then synthetically focusing reflections from the breast. The detection of malignant tumors is achieved by the coherent addition of returns from

Elise C. Fear; X. Li; S. C. Hagness; M. A. Stuchly

2002-01-01

235

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

NASA Astrophysics Data System (ADS)

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.

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

236

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

NASA Astrophysics Data System (ADS)

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.

Gomes, Andrew J.; Backman, Vadim

2013-02-01

237

An addressable confocal microscope for functional imaging of neuronal activity  

NASA Astrophysics Data System (ADS)

The study of computation occurring in single neurons and small networks of interconnected neurons is often limited by (1) the number of sites that can be simultaneously probed with electrophysiology tools such as patch pipettes and (2) the recording speed of fluorescence imaging tools such as confocal or multiphoton microscopy. Even in the line scan mode of galvanometer-based scanners, where one scan dimension is sacrificed to gain overall speed, the effective frame rate is limited to less than 1 kHz with no flexibility in site selection. To overcome these limitations and allow the study of many sites throughout the dendritic arbor, we have developed an addressable confocal laser-scanning microscope that permits recording from user-selected sites-of-interest at high frame rates, in addition to conventional full frame imaging. Our system utilizes acousto-optic deflectors (AODs) in the illumination pathway to allow for rapid user-defined positioning of a focused laser spot. However, since AODs rely on diffraction to steer a laser beam, they cannot effectively descan the fluorescence emission spectrum as done in mirror-based systems which utilize reflection; this prevents the use of a stationary pinhole as a spatial filter. Instead, we implement an addressable spatial filter using a digital micromirror device (DMD) in conjunction with the AODs to achieve confocality. A registration algorithm synchronizes the AODs and DMD such that point illumination and point detection are always colocalized in conjugate image planes. The current version of the confocal system has a spatial resolution of ˜1 mum. Furthermore, by letting the user tailor which sites are visited, we have shown that recordings can be made at an aggregate frame rate of ˜40 kHz. We have successfully demonstrated that the system is capable of optical sectioning and thus exhibits the main advantage of a confocal microscope for light-scattering biological tissue. This property was used to create three-dimensional reconstructions of fluorescently labeled test specimens. Additionally, we have used the system to record intracellular calcium transients using the fluorescent calcium indicator Oregon Green BAPTA-1. The transients were a result of back-propagating action potentials elicited via 1 nA current injections in cultured hippocampal neurons from wild-type mice.

Bansal, Vivek

238

Multiband detectors and application of nanostructured anti-reflection coatings for improved efficiency  

NASA Astrophysics Data System (ADS)

This work describes multiband photon detection techniques based on novel semiconductor device concepts and detector designs with simultaneous detection of different wavelength radiation such as UV and IR. One aim of this investigation is to examine UV and IR detection concepts with a view to resolve some of the issues of existing IR detectors such as high dark current, non uniformity, and low operating temperature and to avoid having additional optical components such as filters in multiband detection. Structures were fabricated to demonstrate the UV and IR detection concepts and determine detector parameters: (i) UV/IR detection based on GaN/AlGaN heterostructures, (ii) Optical characterization of p-type InP thin films were carried out with the idea of developing InP based detectors, (iii) Intervalence band transitions in InGaAsP/InP heterojunction interfacial workfunction internal photoemission (HEIWIP) detectors. Device concepts, detector structures, and experimental results are discussed. In order to reduce reflection, TiO2 and SiO2 nanostructured thin film characterization and application of these as anti-reflection coatings on above mentioned detectors is also discussed.

Jayasinghe, J. A. Ranga Chaminda

239

A sea surface reflectance model for (A)ATSR, and application to aerosol retrievals  

NASA Astrophysics Data System (ADS)

A model of the sea surface bidirectional reflectance distribution function (BRDF) is presented for the visible and near-IR channels (over the spectral range 550 nm to 1.6 ?m) of the dual-viewing Along-Track Scanning Radiometers (ATSRs). The intended application is as part of the Oxford-RAL Aerosols and Clouds (ORAC) retrieval scheme. The model accounts for contributions to the observed reflectance from whitecaps, sun-glint and underlight. Uncertainties in the parametrisations used in the BRDF model are propagated through into the forward model and retrieved state. The new BRDF model offers improved coverage over previous methods, as retrievals are possible into the sun-glint region, through the ATSR dual-viewing system. The new model has been applied in the ORAC aerosol retrieval algorithm to process Advanced ATSR (AATSR) data from September 2004 over the south-eastern Pacific. The assumed error budget is shown to be generally appropriate, meaning the retrieved states are consistent with the measurements and a priori assumptions. The resulting field of aerosol optical depth (AOD) is compared with colocated MODIS-Terra observations, AERONET observations at Tahiti, and cruises over the oceanic region. MODIS and AATSR show similar spatial distributions of AOD, although MODIS reports values which are larger and more variable. It is suggested that assumptions in the MODIS aerosol retrieval algorithm may lead to a positive bias in MODIS AOD of order 0.01 at 550 nm over ocean regions where the wind speed is high.

Sayer, A. M.; Thomas, G. E.; Grainger, R. G.

2010-07-01

240

A sea surface reflectance model for (A)ATSR, and application to aerosol retrievals  

NASA Astrophysics Data System (ADS)

A model of the sea surface bidirectional reflectance distribution function (BRDF) is presented for the visible and near-IR channels (over the spectral range 550 nm to 1.6 ?m) of the dual-viewing Along-Track Scanning Radiometers (ATSRs). The intended application is as part of the Oxford-RAL Aerosols and Clouds (ORAC) retrieval scheme. The model accounts for contributions to the observed reflectance from whitecaps, sun-glint and underlight. Uncertainties in the parametrisations used in the BRDF model are propagated through into the forward model and retrieved state. The new BRDF model offers improved coverage over previous methods, as retrievals are possible into the sun-glint region, through the ATSR dual-viewing system. The new model has been applied in the ORAC aerosol retrieval algorithm to process Advanced ATSR (AATSR) data from September 2004 over the south-eastern Pacific. The assumed error budget is shown to be generally appropriate, meaning the retrieved states are consistent with the measurements and a priori assumptions. The resulting field of aerosol optical depth (AOD) is compared with colocated MODIS-Terra observations, AERONET observations at Tahiti, and cruises over the oceanic region. MODIS and AATSR show similar spatial distributions of AOD, although MODIS reports values which are larger and more variable. It is suggested that assumptions in the MODIS aerosol retrieval algorithm may lead to a positive bias in MODIS AOD of order 0.01 at 550 nm over ocean regions where the wind speed is high.

Sayer, A. M.; Thomas, G. E.; Grainger, R. G.

2010-03-01

241

Application of representative layer theory to near-infrared reflectance spectra of powdered samples.  

PubMed

The diffuse reflectance near-infrared (NIR) spectrum of a powdered sample includes the contribution of specular and diffuse reflectance, which is a function of absorbance and scattering. The fraction of light scattered depends in a complex manner on the physical properties of the sample such as particle size, refraction index, etc. Several theories to study the dependence of NIR spectra on the particle size have been proposed. The best known is the Kubelka-Munk model, an approach based on continuous mathematics. Recently Dahm and Dahm put forward an alternative method, the representative layer theory (RLT), which uses discontinuous mathematics as a basis. This approach can be used to identify and disentangle the scattering and absorbance signals as well as their dependence on the particle size. The scattering and absorption coefficient of NaCl (a nonabsorbing material) and of potassium hydrogen phthalate, KHP (a strong absorber), have been estimated through the application of the representative layer theory, working on a particle size range from 63 to 450 microm. In both samples, the absorption coefficient of the sample (K) remains constant and practically independent of the particle size, while the scattering coefficient of the sample (S) decreases when the particle diameter increases, becoming stable around a diameter of 250 microm. PMID:19094396

Cairós, Carlos; Coello, Jordi; Maspoch, Santiago

2008-12-01

242

Multidepth imaging by chromatic dispersion confocal microscopy  

NASA Astrophysics Data System (ADS)

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.

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

2012-02-01

243

Perfluorodecalin enhances in vivo confocal microscopy resolution of Arabidopsis thaliana mesophyll.  

PubMed

*Air spaces in the leaf mesophyll generate deleterious optical effects that compromise confocal microscopy. *Leaves were mounted in the nontoxic, nonfluorescent perfluorocarbon, perfluorodecalin (PFD), and optical enhancement and physiological effect were assessed using confocal microscopy and chlorophyll fluorescence. *Mounting leaves of Arabidopsis thaliana in PFD significantly improved the optical qualities of the leaf, thereby enabling high-resolution laser scanning confocal imaging over twofold deeper into the mesophyll, compared with using water. Incubation in PFD had less physiological impact on the mounted specimen than water. *We conclude that the application of PFD as a mounting medium substantially increases confocal image resolution of living mesophyll and vascular bundle cells, with minimal physiological impact. PMID:20374500

Littlejohn, George R; Gouveia, João D; Edner, Christoph; Smirnoff, Nicholas; Love, John

2010-06-01

244

Laser-excited confocal-fluorescence gel scanner  

SciTech Connect

A high-sensitivity, laser-excited, confocal-fluorescence scanner has been developed for the detection of fluorescently labeled nucleic acids separated on slab gels. The gel is placed on a motor-driven, two-dimensional scan stage and raster scanned past the optical detection system. The 488-nm argon ion laser beam is introduced into the confocal optical system at a long-pass dichroic beam splitter and focused within the gel to an [similar to]2 [mu]m diameter spot by a high-numerical aperture microscope objective. The resulting fluorescence is gathered by the objective, passed back through the first long-pass beam splitter, and relayed to a second dichroic beam splitter that separates the red and green emissions. The fluorescence is then focused on confocal spatial filters to reduce stray and scattered light, passed through spectral filters, and detected with photomultipliers. The resulting signals are amplified, filtered, and digitized for display on a computer. This system can detect as little as 5[times]10[sup [minus]12] M fluorescein, the resolution as operated is 160 [mu]m, and it can scan a 6 cm[times]6 cm gel using a scan rate of 4 cm/s in 12 min. The detection of DNA on slab gels, two-color DNA fragment sizing, and microtiter plate scanning are presented to illustrate some of the possible applications of this apparatus.

Mathies, R.A.; Scherer, J.R.; Quesada, M.A. (Department of Chemistry, University of California, Berkeley, California 94720 (United States)); Rye, H.S.; Glazer, A.N. (Department of Molecular and Cell Biology, University of California, Berkeley, California 94720 (United States))

1994-04-01

245

Combined In Vivo Confocal Raman Spectroscopy and Confocal Microscopy of Human Skin  

Microsoft Academic Search

In vivo confocal Raman spectroscopy is a noninvasive optical method to obtain detailed information about the molecular composition of the skin with high spatial resolution. In vivo confocal scanning laser microscopy is an imaging modality that provides optical sections of the skin without physically dissecting the tissue. A combination of both techniques in a single instrument is described. This combination

P. J. Caspers; G. W. Lucassen; G. J. Puppels

2003-01-01

246

3D Image Analysis of Geomaterials using Confocal Microscopy  

NASA Astrophysics Data System (ADS)

Confocal microscopy is one of the most significant advances in optical microscopy of the last century. It is widely used in biological sciences but its application to geomaterials lingers due to a number of technical problems. Potentially the technique can perform non-invasive testing on a laser illuminated sample that fluoresces using a unique optical sectioning capability that rejects out-of-focus light reaching the confocal aperture. Fluorescence in geomaterials is commonly induced using epoxy doped with a fluorochrome that is impregnated into the sample to enable discrimination of various features such as void space or material boundaries. However, for many geomaterials, this method cannot be used because they do not naturally fluoresce and because epoxy cannot be impregnated into inaccessible parts of the sample due to lack of permeability. As a result, the confocal images of most geomaterials that have not been pre-processed with extensive sample preparation techniques are of poor quality and lack the necessary image and edge contrast necessary to apply any commonly used segmentation techniques to conduct any quantitative study of its features such as vesicularity, internal structure, etc. In our present work, we are developing a methodology to conduct a quantitative 3D analysis of images of geomaterials collected using a confocal microscope with minimal amount of prior sample preparation and no addition of fluorescence. Two sample geomaterials, a volcanic melt sample and a crystal chip containing fluid inclusions are used to assess the feasibility of the method. A step-by-step process of image analysis includes application of image filtration to enhance the edges or material interfaces and is based on two segmentation techniques: geodesic active contours and region competition. Both techniques have been applied extensively to the analysis of medical MRI images to segment anatomical structures. Preliminary analysis suggests that there is distortion in the shapes of the segmented vesicles, vapor bubbles, and void spaces due to the optical measurements, so corrective actions are being explored. This will establish a practical and reliable framework for an adaptive 3D image processing technique for the analysis of geomaterials using confocal microscopy.

Mulukutla, G.; Proussevitch, A.; Sahagian, D.

2009-05-01

247

Planar concave grating demultiplexer for coarse WDM based on confocal ellipses  

Microsoft Academic Search

A novel planar concave grating demultiplexer is described in which the reflecting facets are placed on confocal ellipses. Total internal reflection is used to reduce the sensitivity to non-vertical etching of the facets. Two beam-shaping parabolic waveguide horns are used on the input waveguide to obtain flat-top passbands and high channel isolation. Scalar electromagnetic simulations show promising results for both

Xianling Chen; J. N. McMullin; C. J. Haugen; R. G. DeCorby

2004-01-01

248

A Ring-Shaped Photodiode Designed for Use in a Reflectance Pulse Oximetry Sensor in Wireless Health Monitoring Applications  

Microsoft Academic Search

We report a photodiode for use in a reflectance pulse oximeter for use in autonomous and low-power homecare applications. The novelty of the reflectance pulse oximeter is a large ring shaped backside silicon pn photodiode. The ring-shaped photodiode gives optimal gathering of light and thereby enable very low light-emitting diode (LED) driving currents for the pulse oximeter. The photodiode also

Sune Bro Duun; Rasmus G. Haahr; Karen Birkelund; Erik V. Thomsen

2010-01-01

249

Active frequency selective surfaces for antenna applications electronically to control phase distribution and reflective\\/transmissive amplification  

Microsoft Academic Search

A planar dipole grid antenna is described deposited on an active frequency selective (FSS) or polarization sensitive surface (PSS) electronically tuneable to control the spatial phase distribution and reflective\\/transmissive amplification. Such dipole grids can be used, for example, in reflector antenna systems composed of multiple reflective and\\/or transmissive subsystems to achieve and serve highly cost-effective multi-purpose applications. It is discussed

P. Edenhofer; A. Alpaslan

2005-01-01

250

Differential confocal microscopy with a wide measuring range based on polychromatic illumination  

NASA Astrophysics Data System (ADS)

A differential confocal microscopy based on polychromatic illumination is proposed to achieve both wide range and high lateral resolution during measurement of a 3D deep-etching microstructure. Two alternating response ranges are obtained by controlling the axial dispersion amount of two focusing beams. Noise in additive and multiplicative modes can be suppressed by using the proposed differential confocal microscopy because an output function is reestablished as the ratio of subtraction and sum values of the two defocusing detectors' responses. The sensing method is very useful for the measurement of micro and sub-micro 3D profiles of microstructures with hybrid material or non-uniform surface reflectance.

Tan, Jiubin; Liu, Jian; Wang, Yuhang

2010-05-01

251

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

NASA Astrophysics Data System (ADS)

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.

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

2014-03-01

252

Spectrally multiplexed chromatic confocal multipoint sensing.  

PubMed

We present a concept for chromatic confocal distance sensing that employs two levels of spectral multiplexing for the parallelized evaluation of multiple lateral measurement points; at the first level, the chromatic confocal principle is used to encode distance information within the spectral distribution of the sensor signal. For lateral multiplexing, the total spectral bandwidth of the sensor is split into bands. Each band is assigned to a different lateral measurement point by a segmented diffractive element. Based on this concept, we experimentally demonstrate a chromatic confocal three-point sensor that is suitable for harsh production environments, since it works with a single-point spectrometer and does not require scanning functionality. The experimental system has a working distance of more than 50 mm, a measurement range of 9 mm, and an axial resolution of 50 ?m. PMID:24322108

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

2013-11-15

253

Analysis for Mar Vel Black and Acetylene Soot Low Reflectivity Surfaces for Star Tracker Sunshade Applications.  

National Technical Information Service (NTIS)

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 ...

E. Yung

1974-01-01

254

Application of infrared reflection microspectroscopy for chemical imaging of cross-sectioned urinary calculi  

NASA Astrophysics Data System (ADS)

We used infrared reflection microspectroscopy for chemical imaging of urinary calculi and showed that contribution of diffuse reflection, influencing the imaging results, can be suppressed by decreasing surface roughness and (or) increasing wavelength of infrared radiation applied for the imaging.

Pucetaite, M.; Banys, J. P.; Sablinskas, V.

2013-06-01

255

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

PubMed

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

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

2014-08-14

256

Application of combined experimental and numerical techniques in determining the temperature dependence of reflectivity of semiconductors  

Microsoft Academic Search

Combined experimental and numerical techniques for determining the temperature dependence of reflectivity of basic semiconductors are analyzed. The method for determination of the reflectivity dependence of liquid semiconductors under pulsed laser irradiation on temperature developed earlier by the authors is modified for the case of solid semiconductors. The results obtained by the time-resolved reflectivity measurement technique together with the known

R. ?erný; V. Cháb; P. Prikryl

1996-01-01

257

Multipass cell based on confocal mirrors for sensitive broadband laser spectroscopy in the near infrared.  

PubMed

We report on broadband absorption spectroscopy in the near IR using a multipass cell design based on highly reflecting mirrors in a confocal arrangement having the particular aim of achieving long optical paths. We demonstrate a path length of 314 m in a cell consisting of two sets of highly reflecting mirrors with identical focal length, spaced 0.5 m apart. The multipass cell covers this path length in a relatively small volume of 1.25 l with the light beam sampling the whole volume. In a first application, the absorption spectra of the greenhouse gases CO(2), CH(4), and CO were measured. In these measurements we used a femtosecond fiber laser with a broadband spectral range spanning the near IR from 1.5 to 1.7 ?m. The absorption spectra show a high signal-to-noise ratio, from which we derive a sensitivity limit of 6 ppmv for methane observed in a mixture with air. PMID:24217732

Mohamed, T; Zhu, F; Chen, S; Strohaber, J; Kolomenskii, A A; Bengali, A A; Schuessler, H A

2013-10-10

258

Focus-drift correction in time-lapse confocal imaging.  

PubMed

In long-term time-lapse imaging of living cells, where recording takes several minutes or longer, a drift of focus may be significant. Focus-drift is due to the slippage in the microscope focus mechanism and/or the thermal gradients in the microscope. Software and hardware solutions may be introduced to correct for the focus-drift. Some autofocus techniques measure position of the specimen by sensing the light or sound reflected from a well-defined surface, such as the microscope slide. An autofocusing approach, where a focus measure is computed for images acquired at different objective positions is less appropriate in confocal microscopy, since more than one section is in focus. To correct for the focal-drift in long-term time-lapse confocal imaging, we acquired an image stack of the specimen periodically. The software calculated Pearson's correlation coefficient between each image in the z-stack and the reference image in the stack, which was selected at the beginning of the experiment. The maximal correlation coefficient of pixel intensities was taken to identify the image, which corresponded to the focal plane of the reference image. To test our approach, we used confocal images of living rat lactotroph cells, which discharged preloaded green fluorescent probe from a single secretory granule. Simultaneously, an extracellularly applied FM 4-64 red fluorescent probe loaded the discharging vesicle and the plasma membrane. We show that our approach is appropriate to correct for focal-drift in long term time-lapse imaging and analysis of living cells. PMID:16154944

Kreft, Marko; Stenovec, Matjaz; Zorec, Robert

2005-06-01

259

Improving spinning disk confocal microscopy by preventing pinhole cross-talk for intravital imaging  

PubMed Central

A recent key requirement in life sciences is the observation of biological processes in their natural in vivo context. However, imaging techniques that allow fast imaging with higher resolution in 3D thick specimens are still limited. Spinning disk confocal microscopy using a Yokogawa Confocal Scanner Unit, which offers high-speed multipoint confocal live imaging, has been found to have wide utility among cell biologists. A conventional Confocal Scanner Unit configuration, however, is not optimized for thick specimens, for which the background noise attributed to “pinhole cross-talk,” which is unintended pinhole transmission of out-of-focus light, limits overall performance in focal discrimination and reduces confocal capability. Here, we improve spinning disk confocal microscopy by eliminating pinhole cross-talk. First, the amount of pinhole cross-talk is reduced by increasing the interpinhole distance. Second, the generation of out-of-focus light is prevented by two-photon excitation that achieves selective-plane illumination. We evaluate the effect of these modifications and test the applicability to the live imaging of green fluorescent protein-expressing model animals. As demonstrated by visualizing the fine details of the 3D cell shape and submicron-size cytoskeletal structures inside animals, these strategies dramatically improve higher-resolution intravital imaging.

Shimozawa, Togo; Yamagata, Kazuo; Kondo, Takefumi; Hayashi, Shigeo; Shitamukai, Atsunori; Konno, Daijiro; Matsuzaki, Fumio; Takayama, Jun; Onami, Shuichi; Nakayama, Hiroshi; Kosugi, Yasuhito; Watanabe, Tomonobu M.; Fujita, Katsumasa; Mimori-Kiyosue, Yuko

2013-01-01

260

Confocal Microscopy for Modeling Electron Microbeam Irradiation of Skin  

SciTech Connect

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.

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

2011-08-01

261

A 94-Ghz Confocal Frequency Reference.  

National Technical Information Service (NTIS)

The construction and calibration of a confocal wavemeter for the 94-GHz region is described. Material selection was predicted upon obtaining a frequency stability of 1 part in 100,000 per degree c over a 34 degree C temperature range. The system uses a 94...

C. J. Zamites

1966-01-01

262

Silicon-micromachined scanning confocal optical microscope  

Microsoft Academic Search

We describe a miniature scanning confocal optical microscope constructed from components micromachined using silicon and fused silica. The design, fabrication, and characterization of the components of the microscope as well as the assembly of the system are described. Sample images acquired using the instrument are also presented

David L. Dickensheets; Gordon S. Kino

1998-01-01

263

Vibrometry using a chromatic confocal sensor  

NASA Astrophysics Data System (ADS)

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.

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

2014-05-01

264

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 ...

265

Imaging intracellular protein dynamics by spinning disk confocal microscopy  

PubMed Central

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.

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

2012-01-01

266

Characterization of lased enamel organic matrix using confocal microscopy  

NASA Astrophysics Data System (ADS)

In the past decade several studies have demonstrated the increased acid resistance in enamel demineralization after laser irradiation. However, the exact mechanism of action to this effect still remains a speculation. Recently, the role of organic matrix was revealed to be significant in the laser-induced inhibition of enamel demineralization. The aim of the present study was to characterize the lipid component of organic matrix in mature lazed enamel and unlazed enamel histochemically using a hydrophobic fluorescent probe with Confocal Laser Scanning Microscope (CLSM). Partial decalcification of thin enamel sections was carried out using 0.5 M of EDTA in a stainless steel grid for 5 hours, following fixation with 3.5% paraformaldehyde. Thereafter the sections were stained with Nile red coupled with CLSM. The intensity of the light reflection was analyzed under the same conditions for all specimens, ruling out the autofluorescence in the control sections. Confocal imaging revealed a diffuse and increased fluorescence of the lipid stain in the lazed areas suggesting that the swelling and coating of organic matrix on the surface of enamel crystals in the peri and interprismatic spaces is rendering the increased acid resistance. These findings will substantiate the proposed organic blocking theory in partially explaining the laser-induced prevention of enamel demineralization.

Hsu, Chin-Ying S.; Girija, Veerappan

2001-10-01

267

Statistical characterization of engineered tissues using confocal mosaic technology  

NASA Astrophysics Data System (ADS)

Characterization of engineered tissues using optical methods often involves tradeoff between the fraction of total volume that is imaged and the spatial resolution. The limitation is not technological but rather practical, having more to do with effective probe designs and computer memory storage for large datasets. In this paper, we propose using confocal mosaicing, a technique used to characterize large volumes of excisioned biopsies from Mohs surgeries, to characterizing collagen gels. This technique stitches together high-resolution 3D images of a series adjacent millimeter sized regions that collectively make up areas that are ~cm2. Image acquisition time is approximately 5 min. The resulting high-resolution images closely resemble hematoxylin and eosin histological sections, only obtained without the time-consuming embedding and sectioning steps. Disk-shaped collagen gels that are 1 ml volume and ~1.5 cm diameter were prepared with smooth muscle cells and imaged at days 1 and 5. Using the digital staining technique, we were able to survey the spatial distribution of cells in the hydrogel and assess spatial heterogeneity in 3D from the fluorescence data. The reflectance data provided information on collagen fibril structure and matrix remodeling by the cells. Digital staining presented the data in a way that is easily interpreted by tissue engineers. Altogether, we believe confocal mosaicing and digital staining represents an important technological novelty that significantly advances nondestructive optical evaluation of engineered tissues.

Levitz, David; Ardeshiri, Ardalan; Ahmed, Jabeer; Gareau, Daniel S.; Jacques, Steven L.

2010-02-01

268

Imaging intracellular protein dynamics by spinning disk confocal microscopy.  

PubMed

The palette of fluorescent proteins (FPs) has grown exponentially over the past decade, and as a result, live imaging of cells expressing fluorescently tagged proteins is becoming more and more mainstream. Spinning disk confocal (SDC) microscopy is a high-speed optical sectioning technique and a method of choice to observe and analyze intracellular FP 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 charge-coupled device cameras, and can achieve frame rates of up to 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 of how other imaging techniques such as total internal reflection 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

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

2012-01-01

269

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

NASA Astrophysics Data System (ADS)

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.

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

2005-01-01

270

Relationship between the Scavenging Coefficient for Pollutants in Precipitation and the Radar Reflectivity Factor. Part II: Applications  

Microsoft Academic Search

The power-law dependences between the scavenging coefficient for pollutants in precipitation and the radar reflectivity factor Z, theoretically derived in Part I, are discussed here from the point of view of applications. Possible problems in their use are related mainly to the uncertain characteristics of the pollutants involved and to common error sources in weather radar measurements of precipitation. The

Kirsti Jylhä

1999-01-01

271

Neutron reflectivity at the solid\\/liquid interface: examples of applications in biophysics  

Microsoft Academic Search

Over the last 20 years, neutron reflection has emerged as a powerful technique for investigating inhomogeneities across an interface, inhomogeneities either in composition (Lu and Thomas 1998 J. Chem. Soc. Faraday Trans.94 995) or magnetization (Felcher 1981 Phys. Rev. B 24 1995). By measuring the reflected over the incoming intensity of a well collimated beam striking at an interface, as

Giovanna Fragneto-Cusani

2001-01-01

272

EBG identification by the Reflection Phase Method (RPM) design for application WiFi antenna  

Microsoft Academic Search

In a first part of this article, we present the method based on the reflection phase diagram for the identification of the EBG (electromagnetic band gap) structures. The procedure consists to plot the diagram of phase of the wave reflected by EBG structure excited by an incident wave, in the simplest case, plane and normal upon the structure. The forbidden

Moussa Elayachi; Patrice Brachat; Philippe Ratajczak

2006-01-01

273

Using canopy reflectance to monitor corn response to nitrogen and the effects of delayed nitrogen application  

Microsoft Academic Search

Nitrogen (N) fertilizer is one of the most important and expensive inputs for a corn crop. Current Indiana N recommendations are based upon yield goals. As corn yields continue to rise, N recommendations need to be reevaluated. Reflectance measurements using a crop reflectance sensor during the growing season may be useful for determining the need for additional N. The objectives

Daniel Joseph Emmert

2009-01-01

274

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

NASA Technical Reports Server (NTRS)

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.

Yung, E.

1974-01-01

275

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

NASA Technical Reports Server (NTRS)

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.

Pepper, Stephen V.

1995-01-01

276

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

SciTech Connect

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.

Barnett, C.S.

1985-08-20

277

Confocal microscopy through a fiber-optic imaging bundle  

Microsoft Academic Search

The concept for a new type of confocal microscope with a fiber-optic imaging bundle is presented, and experimental results are shown to demonstrate the principle. The primary advantage of the system is the flexibility of imaging samples that would otherwise be inaccessible to confocal microscopy. Optical scanning confocal microscopy is a well- established technique offering significant advan- tages over conventional

Arthur F. Gmitro; David Aziz

1993-01-01

278

Endoscopic probe optics for spectrally encoded confocal microscopy.  

PubMed

Spectrally encoded confocal microscopy (SECM) is a form of reflectance confocal microscopy that can achieve high imaging speeds using relatively simple probe optics. Previously, the feasibility of conducting large-area SECM imaging of the esophagus in bench top setups has been demonstrated. Challenges remain, however, in translating SECM into a clinically-useable device; the tissue imaging performance should be improved, and the probe size needs to be significantly reduced so that it can fit into luminal organs of interest. In this paper, we report the development of new SECM endoscopic probe optics that addresses these challenges. A custom water-immersion aspheric singlet (NA = 0.5) was developed and used as the objective lens. The water-immersion condition was used to reduce the spherical aberrations and specular reflection from the tissue surface, which enables cellular imaging of the tissue deep below the surface. A custom collimation lens and a small-size grating were used along with the custom aspheric singlet to reduce the probe size. A dual-clad fiber was used to provide both the single- and multi- mode detection modes. The SECM probe optics was made to be 5.85 mm in diameter and 30 mm in length, which is small enough for safe and comfortable endoscopic imaging of the gastrointestinal tract. The lateral resolution was 1.8 and 2.3 µm for the single- and multi- mode detection modes, respectively, and the axial resolution 11 and 17 µm. SECM images of the swine esophageal tissue demonstrated the capability of this device to enable the visualization of characteristic cellular structural features, including basal cell nuclei and papillae, down to the imaging depth of 260 µm. These results suggest that the new SECM endoscopic probe optics will be useful for imaging large areas of the esophagus at the cellular scale in vivo. PMID:24156054

Kang, Dongkyun; Carruth, Robert W; Kim, Minkyu; Schlachter, Simon C; Shishkov, Milen; Woods, Kevin; Tabatabaei, Nima; Wu, Tao; Tearney, Guillermo J

2013-01-01

279

Endoscopic probe optics for spectrally encoded confocal microscopy  

PubMed Central

Spectrally encoded confocal microscopy (SECM) is a form of reflectance confocal microscopy that can achieve high imaging speeds using relatively simple probe optics. Previously, the feasibility of conducting large-area SECM imaging of the esophagus in bench top setups has been demonstrated. Challenges remain, however, in translating SECM into a clinically-useable device; the tissue imaging performance should be improved, and the probe size needs to be significantly reduced so that it can fit into luminal organs of interest. In this paper, we report the development of new SECM endoscopic probe optics that addresses these challenges. A custom water-immersion aspheric singlet (NA = 0.5) was developed and used as the objective lens. The water-immersion condition was used to reduce the spherical aberrations and specular reflection from the tissue surface, which enables cellular imaging of the tissue deep below the surface. A custom collimation lens and a small-size grating were used along with the custom aspheric singlet to reduce the probe size. A dual-clad fiber was used to provide both the single- and multi- mode detection modes. The SECM probe optics was made to be 5.85 mm in diameter and 30 mm in length, which is small enough for safe and comfortable endoscopic imaging of the gastrointestinal tract. The lateral resolution was 1.8 and 2.3 µm for the single- and multi- mode detection modes, respectively, and the axial resolution 11 and 17 µm. SECM images of the swine esophageal tissue demonstrated the capability of this device to enable the visualization of characteristic cellular structural features, including basal cell nuclei and papillae, down to the imaging depth of 260 µm. These results suggest that the new SECM endoscopic probe optics will be useful for imaging large areas of the esophagus at the cellular scale in vivo.

Kang, DongKyun; Carruth, Robert W.; Kim, Minkyu; Schlachter, Simon C.; Shishkov, Milen; Woods, Kevin; Tabatabaei, Nima; Wu, Tao; Tearney, Guillermo J.

2013-01-01

280

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

NASA Technical Reports Server (NTRS)

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.

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

1976-01-01

281

Single-layered PDLC films for electrically variable laser light reflection application  

NASA Astrophysics Data System (ADS)

Electrically controllable two-beam reflection of coherent light double-passed through the microscale polymer-dispersed liquid crystal (PDLC) single layer is reported. By PDLC medium, the intensities of two reflected beams can be reciprocally changed by applying a suitable voltage in the range 0-100 V. The optical phase shift electrically induced for coherent light propagating in two passes through the single-layered PDLC film, as well as the additional phase shift externally introduced by the substrate of the PDLC cell, are responsible for the electrically controllable reflection in a pair of two beams with complementary voltage-dependent intensity behaviors.

Marinov, Yordan G.; Hadjichristov, Georgi B.; Petrov, Alexander G.

2010-12-01

282

Confocal ?-XRF depth analysis of paint layers  

Microsoft Academic Search

Focused narrow-band beam of the synchrotron radiation was used for in-depth analysis of historic and modern paint layers. The fluorescent radiation induced by 21 keV impact radiation was detected by a Si(Li) detector equipped with a polycapillary X-ray lens in con-focal geometry. Scanning of the sample was performed by a motorized x–y–z stage. Space resolution of 30 ?m was achieved.

Ž. Šmit; K. Janssens; K. Proost; I. Langus

2004-01-01

283

MEMS-Based Dual Axes Confocal Microendoscopy  

PubMed Central

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.

Piyawattanametha, Wibool; Wang, Thomas D.

2011-01-01

284

In vivo confocal and multiphoton microendoscopy  

PubMed Central

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.

Kim, Pilhan; Puoris'haag, Mehron; Cote, Daniel; Lin, Charles P.; Yun, Seok H.

2009-01-01

285

Spectrally encoded confocal scanning laser ophthalmoscope  

NASA Astrophysics Data System (ADS)

Fundus imaging has become an essential clinical diagnostic tool in ophthalmology. Current generation scanning laser ophthalmoscopes (SLO) offer advantages over conventional fundus photography and indirect ophthalmoscopy in terms of light efficiency and contrast. As a result of the ability of SLO to provide rapid, continuous imaging of retinal structures and its versatility in accommodating a variety of illumination wavelengths, allowing for imaging of both endogenous and exogenous fluorescent contrast agents, SLO has become a powerful tool for the characterization of retinal pathologies. However, common implementations of SLO, such as the confocal scanning laser ophthalmoscope (CSLO) and line-scanning laser ophthalmoscope (LSLO), require imaging or multidimensional scanning elements which are typically implemented in bulk optics placed close to the subject eye. Here, we apply a spectral encoding technique in one dimension combined with single-axis lateral scanning to create a spectrally encoded confocal scanning laser ophthalmoscope (SECSLO) which is fully confocal. This novel implementation of the SLO allows for high contrast, high resolution in vivo human retinal imaging with image transmission through a single-mode optical fiber. Furthermore, the scanning optics are similar and the detection engine is identical to that of current-generation spectral domain optical coherence tomography (SDOCT) systems, potentially allowing for a simplistic implementation of a joint SECSLO-SDOCT imaging system.

Tao, Yuankai K.; Izatt, Joseph A.

2010-02-01

286

Quantification of Multilayer Samples by Confocal ?XRF  

NASA Astrophysics Data System (ADS)

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 ?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.

Pérez, R. Daniel; Sánchez, H. J.; Pérez, C. A.; Rubio, M.

2009-01-01

287

A near-infrared confocal scanner  

NASA Astrophysics Data System (ADS)

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

Lee, Seungwoo; Yoo, Hongki

2014-06-01

288

Laser scanning confocal microscopy in materials engineering  

NASA Astrophysics Data System (ADS)

In materials engineering, we are often faced with a necessity to display the shape and morphology of studied surfaces. This is essential for surface evaluation of various components as well as for new materials research. Several imaging techniques are available for such purposes. One of the most appropriate of them is laser scanning confocal microscopy. The magnification range of this technique satisfies the needs of researchers working between the limits of conventional optical microscopes and scanning electron microscopes. It overcomes the limitations of optical microscopy by better lateral resolution, ability to control the depth of field and possibility of high-resolution 3D imaging of relatively thick samples. Compared to the more advanced (and more expensive) scanning electron microscopes, laser scanning confocal microscopy has no special requirement for the sample preparation and there is also no need to measure in vacuum. Particular examples of laser scanning confocal microscopy beneficial use are presented in this paper. Scratch track evaluation, diamonds tip control, Tyvek structure examination and measurement of surface characteristics of a wire saw cut on the glass are reported.

Tomáštík, Jan; Šebestová, Hana; ?tvrtlík, Radim; Schovánek, Petr

2012-01-01

289

Standing Wave Pattern of HF Radio Waves in the Ionospheric Reflection Region. Part 2. Applications.  

National Technical Information Service (NTIS)

General analytical formulas derived within a uniform approximation are utilized for determining the wave pattern of a vertically propagating HF wave totally or partially reflected from the ionosphere. The full three-dimensional wave is calculated accurate...

B. Lundborg B. Thide

1985-01-01

290

The application of complex Pade approximants to reflection at optical waveguide facets  

Microsoft Academic Search

We demonstrate that the numerical instabilities associated with the use of the standard real Pade approximation for the reflection operator can be avoided through either a complex Pade expression or a branch-cut rotation in the complex plane

Hatem El-Refaei; Ian Betty; David Yevick

2000-01-01

291

Layer KKR approach to Bloch-wave transmission and reflection: Application to spin-dependent tunneling  

SciTech Connect

Bloch waves may be reflected and transmitted by planar interfaces. In this paper, we show how the reflection and transmission amplitudes for Bloch waves can be calculated within the layer Korringa-Kohn-Rostoker formalism. The calculated transmission probability is used to calculate the spin-dependent tunneling conductance for magnetic tunnel junctions formed from ZnSe semiconducting layers sandwiched between two ferromagnetic Fe layers. {copyright} {ital 1999} {ital The American Physical Society}

MacLaren, J.M. [Department of Physics, Tulane University, New Orleans, Louisiana 70118 (United States)] [Department of Physics, Tulane University, New Orleans, Louisiana 70118 (United States); Zhang, X. [Computational Physics and Engineering Division, Oak Ridge National Laboratory, P.O. Box 2008, Oak Ridge, Tennessee 37831-6114 (United States)] [Computational Physics and Engineering Division, Oak Ridge National Laboratory, P.O. Box 2008, Oak Ridge, Tennessee 37831-6114 (United States); Butler, W.H.; Wang, X. [Metals and Ceramics Division, Oak Ridge National Laboratory, P.O. Box 2008, Oak Ridge, Tennessee 37831-6114 (United States)] [Metals and Ceramics Division, Oak Ridge National Laboratory, P.O. Box 2008, Oak Ridge, Tennessee 37831-6114 (United States)

1999-02-01

292

In vivo 783-channel diffuse reflectance imaging system and its application  

Microsoft Academic Search

A fiber-based reflectance imaging system was constructed to produce in vivo absorption spectroscopic images of biological tissues with diffuse light in the cw domain. The principal part of this system is the 783-channel fiber probe, composed of 253 illumination fibers and 530 detection fibers distributed in a 20×20 mm square region. During illumination with the 253 illumination fibers, diffuse reflected

Joon-Mo Yang; Yong-Hui Han; Gilwon Yoon; Byung Soo Ahn; Byung-Cheon Lee; Kwang-Sup Soh

2007-01-01

293

Application of combined experimental and numerical techniques in determining the temperature dependence of reflectivity of semiconductors  

SciTech Connect

Combined experimental and numerical techniques for determining the temperature dependence of reflectivity of basic semiconductors are analyzed. The method for determination of the reflectivity dependence of liquid semiconductors under pulsed laser irradiation on temperature developed earlier by the authors is modified for the case of solid semiconductors. The results obtained by the time-resolved reflectivity measurement technique together with the known temperature dependencies of the refraction index and the extinction coefficient for the cw probe laser and the room-temperature data for the reflectivity at the frequency of the primary pulsed laser beam are the input parameters of this method. The method itself consists in matching the experimental and computed values of the maximum reflectivity of cw probe laser in dependence on the energy density of the laser pulse and a least-squares fitting procedure. The method is verified on experimental data for the XeCl excimer laser irradiation of Si(100), giving R{sub s} = 0.590 {+-} 0.005 + (4.5 {+-} 0.5) x10{sup -5} (T-293) for the reflectivity of crystalline silicon, which is in good agreement with experimental measurements done by other investigators. In addition, numerical test and error analyses of both the method presented here and the previous method proposed for liquid semiconductors are described and the accuracy and error limits of both methods are discussed.

Cerny, R. [Czech Technical Univ., Thakurova (Czech Republic); Chab, V. [Inst. of Physics, Prague (Czech Republic); Prikryl, P. [Mathematical Inst., Prague (Czech Republic)

1996-03-01

294

Application of combined experimental and numerical techniques in determining the temperature dependence of reflectivity of semiconductors  

NASA Astrophysics Data System (ADS)

Combined experimental and numerical techniques for determining the temperature dependence of reflectivity of basic semiconductors are analyzed. The method for determination of the reflectivity dependence of liquid semiconductors under pulsed laser irradiation on temperature developed earlier by the authors is modified for the case of solid semiconductors. The results obtained by the time-resolved reflectivity measurement technique together with the known temperature dependencies of the refraction index and the extinction coefficient for the cw probe laser and the room-temperature data for the reflectivity at the frequency of the primary pulsed laser beam are the input parameters of this method. The method itself consists in matching the experimental and computed values of the maximum reflectivity of cw probe laser in dependence on the energy density of the laser pulse and a least-squares fitting procedure. The method is verified on experimental data for the XeCl excimer laser irradiation of Si( 100), giving R s=0.590±0.005+(4.5±0.5)× 10-5( T-293) for the reflectivity of crystalline silicon, which is in good agreement with experimental measurements done by other investigators. In addition, numerical test and error analyses of both the method presented here and the previous method proposed for liquid semiconductors are described and the accuracy and error limits of both methods are discussed.

?erný, R.; Cháb, V.; P?ikryl, P.

1996-03-01

295

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

USGS Publications Warehouse

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.

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

1994-01-01

296

Materials and corrosion characterization using the confocal resonator  

SciTech Connect

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.

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

1997-05-01

297

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

PubMed

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

Hng, Keng Imm; Dormann, Dirk

2013-01-01

298

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

PubMed Central

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

Hng, Keng Imm; Dormann, Dirk

2013-01-01

299

Characterization of Lipid Bilayer Phases by Confocal Microscopy and Fluorescence Correlation Spectroscopy  

Microsoft Academic Search

We report the application of confocal imaging and fluorescence correlation spectroscopy (FCS) to characterize chemically well-defined lipid bilayer models for biomembranes. Giant unilamellar vesicles of dilauroyl phosphatidylcholine\\/dipalmitoyl phosphatidylcholine (DLPC\\/DPPC)\\/cholesterol were imaged by confocal fluorescence microscopy with two fluorescent probes, 1,1'-dieicosanyl-3,3,3',3'- tetramethylindocarbocyanine perchlorate (DiI-C20) and 2-(4,4-difluoro-5,7-dimethyl-4-bora-3a,4a-diaza-s-indacene-3-pentanoyl)- 1-hexadecanoyl-sn-glycero-3-phosphocholine (Bodipy-PC). Phase separation was visualized by differential probe partition into the coexisting phases. Three-dimensional

Jonas Korlach; Petra Schwille; Watt W. Webb; Gerald W. Feigenson

1999-01-01

300

Aggregation process of asphaltenes in a Venezuelan crude oil using Confocal Microscopy  

NASA Astrophysics Data System (ADS)

The asphaltenes flocculation process in heavy crude oils is a subject of great interest for the oil industry due to the negative effect of this process in the oil extraction. In this work we present the application of the Confocal Microscopy to the study of the aggregation process of asphaltene in crude oils. The advantages of the technique for study of the particles in surface and in the dispersed phase are shown. Confocal images of different shows changes in the behavior of the differents solutions. The results can be related with the stability and the prediction of asphaltene precipitation in crude oils.

Hung, Jannett; Castillo, Jimmy A.; Goncalves Abreu, Sonia; Fernandez, Alberto

2003-11-01

301

Development and Application of An Efficient and Effective Approach to Simulate the Hyperspectral Reflectance Over Large Temporal and Spatial Scales  

NASA Astrophysics Data System (ADS)

Atmospheric and surface properties have been measured from space with various spatial resolutions for decades. It is very challenging to derive the mean solar spectral radiance or reflectance over large temporal and spatial scales by explicit radiative transfer computations from the large volume of instantaneous data, especially at high spectral resolution. We propose a procedurally simple but effective method to compute the solar spectral reflectance in large climate domains, in which the probability distribution function (PDF) of cloud optical depth is used to account for the wide variation of cloud properties in different sensor footprints, and to avoid the repeated computations for footprints with similar conditions. This approach is tested with MODIS/CERES data and evaluated with SCIAMACHY measured spectral reflectance. The mean difference between model and observation is about 3% for the monthly global mean reflectance. This PDF-based approach provides a simple, fast, and effective way to simulate the mean spectral reflectance over large time and space scales with a large volume of high-resolution satellite data. The application of this approach to the hyperspectral simulation for NASA's CLARRREO project is demonstrated.

Jin, Z.

2013-12-01

302

Estimation of anisotropic blur for the restoration of confocal images  

NASA Astrophysics Data System (ADS)

We present a novel method for joint estimation of the degradation and restoration of photon-limited images. Our method will be demonstrated on confocal microscope images, since confocal microscopy is an important tool in many academic (fundamental biology, . . . ) and industrial (material science, pharmaceutical industry, . . . ) applications. However, the observed images are usually degraded, which hinders analysis and interpretation of the images. Degradation in this kind of images is due to two sources: first, we have blurring due to the bandlimited nature of the optical system; second, Poisson noise contaminates the observations due to the discrete nature of the photon detection process. The proposed method iterates noise reduction and blur estimation using the steerable pyramid transform (which is a variant of the wavelet transform) and deconvolution in the signal domain. These steps are applied in two phases, a training phase and a restoration phase. In the first phase, these three steps are iterated until the blur estimation converges. The second phase is the actual restoration phase. During the iterations the blur estimation serves as a sharpness measure for the restored image, and is used to controls the number of iterations. So, our integrated method provides a completely automatic algorithm where no prior information about the image degradation is required. Our integrated technique was compared with other common restoration techniques for these kind of images, and provided the best restoration results, with least artifacts.

Rooms, Filip; Philips, Wilfried; Van Oostveldt, Patrick

2004-02-01

303

Variational attenuation correction in two-view confocal microscopy  

PubMed Central

Background Absorption and refraction induced signal attenuation can seriously hinder the extraction of quantitative information from confocal microscopic data. This signal attenuation can be estimated and corrected by algorithms that use physical image formation models. Especially in thick heterogeneous samples, current single view based models are unable to solve the underdetermined problem of estimating the attenuation-free intensities. Results We present a variational approach to estimate both, the real intensities and the spatially variant attenuation from two views of the same sample from opposite sides. Assuming noise-free measurements throughout the whole volume and pure absorption, this would in theory allow a perfect reconstruction without further assumptions. To cope with real world data, our approach respects photon noise, estimates apparent bleaching between the two recordings, and constrains the attenuation field to be smooth and sparse to avoid spurious attenuation estimates in regions lacking valid measurements. Conclusions We quantify the reconstruction quality on simulated data and compare it to the state-of-the art two-view approach and commonly used one-factor-per-slice approaches like the exponential decay model. Additionally we show its real-world applicability on model organisms from zoology (zebrafish) and botany (Arabidopsis). The results from these experiments show that the proposed approach improves the quantification of confocal microscopic data of thick specimen.

2013-01-01

304

Detection and Spectroscopy of Gold Nanoparticles Using Supercontinuum White Light Confocal Microscopy  

NASA Astrophysics Data System (ADS)

We combine confocal microscopy using supercontinuum laser illumination and an interferometric detection technique to identify single nanoparticles of diameter below 10nm. Spectral analysis of the signal allows us to record the plasmon resonance of a single nanoparticle. Our results hold great promise for fundamental studies of the optical properties of single metal clusters and for their use in biophysical applications.

Lindfors, K.; Kalkbrenner, T.; Stoller, P.; Sandoghdar, V.

2004-07-01

305

Rapid semi-automated segmentation and analysis of neuronal morphology and function from confocal image data  

Microsoft Academic Search

Confocal microscopy combined with cellular labeling techniques can be an effective method for imaging the morphology of a cell as well as various functional characteristics in vivo. Current analysis methods are manual, and therefore, time-consuming and prone to error. Through the development of custom algorithms and application design, the analysis process can be improved to decrease analysis time and increase

David R. Holmes III; M. J. Moore; C. B. Mantilla; Gary C Sieck; Richard A. Robb

2002-01-01

306

In vivo Confocal Laser Scanning Microscopy and Micropuncture in Intact Rat  

Microsoft Academic Search

Background: Intravital microscopy theoretically provides the optimal conditions for studying specific organ functions. However, the application of microscopy in intact organs in vivo has been limited so far due to technical difficulties. The purpose of this study was to establish a method of in vivo confocal laser scanning microscopy (CLSM) for the study of endocytosis in proximal tubules of intact

Yoshio Ohno; Henrik Birn; Erik I. Christensen

2005-01-01

307

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

PubMed

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

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

2007-01-01

308

Hematopoiesis in 3 dimensions: human and murine bone marrow architecture visualized by confocal microscopy  

PubMed Central

In many animals, blood cell production occurs in the bone marrow. Hematopoiesis is complex, requiring self-renewing and pluripotent stem cells, differentiated progenitor and precursor cells, and supportive stroma, adipose tissue, vascular structures, and extracellular matrix. Although imaging is a vital tool in hematology research, the 3-dimensional architecture of the bone marrow tissue in situ remains largely uncharacterized. The major hindrance to imaging the intact marrow is the surrounding bone structures are almost impossible to cut/image through. We have overcome these obstacles and describe a method whereby whole-mounts of bone marrow tissue were immunostained and imaged in 3 dimensions by confocal fluorescence and reflection microscopy. We have successfully mapped by multicolor immunofluorescence the localization pattern of as many as 4 cell features simultaneously over large tiled views and to depths of approximately 150 ?m. Three-dimensional images can be assessed qualitatively and quantitatively to appreciate the distribution of cell types and their interrelationships, with minimal perturbations of the tissue. We demonstrate its application to normal mouse and human marrow, to murine models of marrow failure, and to patients with aplastic anemia, myeloid, and lymphoid cell malignancies. The technique should be generally adaptable for basic laboratory investigation and for clinical diagnosis of hematologic diseases.

Malide, Daniela; Chen, Jichun; Calado, Rodrigo T.; Kajigaya, Sachiko; Young, Neal S.

2010-01-01

309

Application of the IMM-JPDA filter to multiple target tracking in total internal reflection fluorescence microscopy images.  

PubMed

We propose a multi-target tracking method using an Interacting Multiple Model Joint Probabilistic Data Association (IMM-JPDA) filter for tracking vesicles in total internal reflection fluorescence microscopy (TIRFM) sequences. We enhance the accuracy and reliability of the algorithm by tailoring an appropriate framework to this application. Evaluation of our algorithm is performed on both realistic synthetic data and real TIRFM data. Our results are compared against related methods and a commercial tracking software. PMID:23285571

Rezatofighi, Seyed Hamid; Gould, Stephen; Hartley, Richard; Mele, Katarina; Hughes, William E

2012-01-01

310

Principles of perfect and ultrathin anti-reflection with applications to transparent electrode  

NASA Astrophysics Data System (ADS)

Anti-reflection(AR), a well-known technique of reducing unwanted reflections by applying an impedance matching layer, works for a specific wavelength and require the coating layer to be a quarter wavelength thick. A broadband operation of AR, however, is not fully understood except for the trial and error method. Here, we present a systematic analytic method of AR without the restriction of wavelength or thickness, i.e. achieving a perfect AR. Specifically, we find analytic permittivity and permeability profiles that remove any given impedance mismatch at the interface between two different dielectrics in a frequency independent way. Ultra-thin AR coating is also shown to be possible and confirmed experimentally with the l/25-wavelength thick AR coating layer made of metamaterials. We apply the concept of ultrathin double layer AR to the transparent conducting electrode, which we demonstrate by fabricating a low reflective dielectric/metal-layered electrode that provides significant electrical conductivity and light transparency.

Kim, Kyoung-Ho; Park, Q.-Han

2014-03-01

311

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

NASA Astrophysics Data System (ADS)

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.

Fischer, E. M.; Pieters, C. M.

1993-04-01

312

[Application of near-infrared diffuse reflectance spectroscopy to the detection and identification of transgenic corn].  

PubMed

With the rapid development of the GMO, more and more GMO food has been pouring into the market. Much attention has been paid to GMO labeling under the controversy of GMO safety. Transgenic corns and their parents were scanned by continuous wave of near infrared diffuse reflectance spectroscopy range of 12000-4000 cm(-1); the resolution was 4 cm(-1); scanning was carried out for 64 times; BP algorithm was applied for data processing. The GMO food was easily resolved. Near-infrared diffuse reflectance spectroscopy is unpolluted and inexpensive compared with PCR and ELISA, so it is a very promising detection method for GMO food. PMID:16395887

Rui, Yu-kui; Luo, Yun-bo; Huang, Kun-lun; Wang, Wei-min; Zhang, Lu-da

2005-10-01

313

Reflecting Reflective Practice  

ERIC Educational Resources Information Center

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…

Galea, Simone

2012-01-01

314

An approximate form of the Rayleigh reflection loss and its phase: application to reverberation calculation.  

PubMed

A useful approximation to the Rayleigh reflection coefficient for two half-spaces composed of water over sediment is derived. This exhibits dependence on angle that may deviate considerably from linear in the interval between grazing and critical. It shows that the non-linearity can be expressed as a separate function that multiplies the linear loss coefficient. This non-linearity term depends only on sediment density and does not depend on sediment sound speed or volume absorption. The non-linearity term tends to unity, i.e., the reflection loss becomes effectively linear, when the density ratio is about 1.27. The reflection phase in the same approximation leads to the well-known "effective depth" and "lateral shift." A class of closed-form reverberation (and signal-to-reverberation) expressions has already been developed [C. H. Harrison, J. Acoust. Soc. Am. 114, 2744-2756 (2003); C. H. Harrison, J. Comput. Acoust. 13, 317-340 (2005); C. H. Harrison, IEEE J. Ocean. Eng. 30, 660-675 (2005)]. The findings of this paper enable one to convert these reverberation expressions from simple linear loss to more general reflecting environments. Correction curves are calculated in terms of sediment density. These curves are applied to a test case taken from a recent ONR-funded Reverberation Workshop. PMID:20649200

Harrison, Chris H

2010-07-01

315

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

Microsoft Academic Search

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 reflec- tance signatures. In multispectral fluorescence and reflectance set-ups, images are separately acquired for the fluorescence in the blue, green, red, and

Sandor Lenk; Laury Chaerle; Erhard E. Pfundel; Gabriele Langsdorf; Dik Hagenbeek; Hartmut K. Lichtenthaler; Dominique Van Der Straeten; Claus Buschmann

2010-01-01

316

Integrated Application of Borehole Radar Reflection and Resistivity Tomography to Delineate Fractures at a Granite Quarry  

Microsoft Academic Search

To delineate the inhomogeneities including fractures and to estimate the freshness of rock, borehole radar and resistivity tomography surveys were conducted at a granite quarry mine in Korea. Borehole radar reflection images were obtained at five boreholes and we could get high resolution image of fractures. Spatial orientations of fractures, however, could not be attained because of omni-directional characteristic of

Myeong-Jong Yi; Jung-Ho Kim; Seong-Jun Cho; Motoyuki Sato

2005-01-01

317

Attenuated total reflection mid-infrared spectroscopy for clinical chemistry applications using silver halide fibers  

Microsoft Academic Search

The quantitative analysis of biotic fluids can be carried out using attenuated total reflection mid-infrared spectroscopy based on silver halide fibers, because good optical throughput can be achieved especially in the fingerprint region of the mid-infrared spectral range. The advantages and prospects of this technique using biofluids or dry films, obtained from such aqueous solutions, are discussed in the context

H. M Heise; L Küpper; L. N Butvina

1998-01-01

318

Design study of a visible/infrared periscope for intense radiation applications using reflective optics  

NASA Astrophysics Data System (ADS)

In magnetically confined fusion devices employing deuterium-tritium (D-T) operation, refractive optical components exposed to neutron and gamma radiation can be subject to degradation of the transmission characteristics, induced luminescence, and altered mechanical properties including dimensional changes. Although radiation resistant refractive optics functioned well for the Tokamak Fusion Test Reactor periscope system during D-T operation, this design approach is unpromising in the much more hostile radiation environment of future D-T devices such as International Thermonuclear Experimental Reactor (ITER). Under contract to the Princeton Plasma Physics Laboratory, Ball Aerospace of Colorado carried out a periscope design study based on the use of reflective optics. In this design, beryllium reflective input optics supported by a fused silica optical bench were interfaced to a Cassegrain relay system to transfer plasma images to remotely located cameras. This system is also capable of measuring first-wall surface temperatures in the range of 300-2000 °C even under projected heating of the reflective optics themselves to several hundred degrees Celsius. Tests of beryllium mirror samples, however, revealed that operation at temperatures above 700 °C leads to a loss of specular reflectivity, thus placing an upper limit on the acceptable thermal environment. The main results of this periscope study are presented in this article.

Medley, S. S.

1999-01-01

319

Application of a multilayer perceptron neural network to phytoplankton concentration using marine reflectance measures  

NASA Astrophysics Data System (ADS)

The multilayer perceptron (MLP) neural network have been widely used to fit non-linear transfer function and performed well. In this study, we use MLP to estimate chlorophyll-a concentrations from marine reflectance measures. The optical data were assembled from the Sea-viewing Wide Field-of-view Sensor (SeaWiFS) Bio-optical Algorithm Mini-workshop (SeaBAM). Most bio-optical algorithms use simple ratios of reflectance in blue and green bands or combinations of ratios as parameters for regression analysis. Regression analysis has limitations for nonlinear function. Neural network, however, have been shown better performance for nonlinear problems. The result showed that accuracy of chlorophyll-a concentration using MLP is much higher than that of regression method. Nevertheless, using all of the five bands as input can derive the best performance. The results showed that each band could carry some useful messages for ocean color remote sensing. Only using band ratio (OC2) or band switch (OC4) might lose some available information. By preprocessing reflectance data with the principle component analysis (PCA), MLP could derive much better accuracy than traditional methods. The result showed that the reflectance of all bands should not be ignored for deriving the chlorophyll-a concentration because each band carries different useful ocean color information.

Su, Feng-Chun; Ho, Chung-Ru; Kuo, Nan-Jung

2005-01-01

320

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

Microsoft Academic Search

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

Eric Michael Louchard

2003-01-01

321

Design Study of a Visible/Infrared Periscope for Intense Radiation Applications using Reflective Optics  

SciTech Connect

In magnetically confined fusion devices employing deuterium-tritium (D-T) operation, refractive optical components exposed to neutron and gamma radiation can be subject to degradation of the transmission characteristics, induced luminescence, and altered mechanical properties including dimensional changes. Although radiation resistant refractive optics functioned well for the Tokamak Fusion Test Reactor (TFTR) periscope system during D-T operation, this design approach is unpromising in the much more hostile radiation environment of future D-T devices such as the International Thermonumclear Experimental Reactor (ITER). Under contract to the Princeton Plasma Physics Laboratory, Ball Aerospace of Colorado carried out a periscope design study based on the use of reflective optics. In this design, beryllium reflective input optics supported by a fused silica optical bench were interfaced to a Cassegrain relay system to transfer plasma images to remotely located cameras. This system is also capable of measuring first-wall surface temperatures in the range of 300 - 2,000 degrees C even under projected heating of the reflective optics themselves to several hundred degrees Celsius. Tests of beryllium mirror samples, however, revealed that operation at temperatures above 700 degrees C leads to a loss of specular reflectivity, thus placing an upper limit on the acceptable thermal environment. The main results of this periscope study are presented in this paper.

Medley, S.S.

1998-05-01

322

Practical Application of Polarization and Light Control for Reduction of Reflected Glare.  

ERIC Educational Resources Information Center

The role of reflected glare and visual viewing angles in near task performance is discussed, and following statements are reported--(1) a worker at a desk normally assumes a position in which his eyes traverse an area of work extending from a point approximately vertically below his eyes to a point not more than 40 degrees from the vertical, (2) a…

Crouch, C. L.; Kaufman, J. E.

1963-01-01

323

Comparison of line-scanned and point-scanned dual-axis confocal microscope performance.  

PubMed

The point-scanned dual-axis confocal (PS-DAC) microscope has been shown to exhibit superior capability to reject out-of-focus and multiply scattered light in comparison to its conventional single-axis counterpart. However, the slow frame rate (typically <5 Hz) resulting from point-by-point data collection makes these systems vulnerable to motion artifacts. While video-rate point-scanned confocal microscopy is possible, a line-scanned dual-axis confocal (LS-DAC) microscope provides a simpler means of achieving high-speed imaging through line-by-line data collection, but sacrifices contrast due to loss of confocality along one dimension. Here we evaluate the performance trade-offs between an LS-DAC and PS-DAC microscope with identical spatial resolutions. Characterization experiments of the LS-DAC and PS-DAC microscopes with tissue phantoms, in reflectance mode, are shown to match results from Monte Carlo scattering simulations of the systems. Fluorescence images of mouse brain vasculature, obtained using resolution-matched LS-DAC and PS-DAC microscopes, demonstrate the comparable performance of LS-DAC and PS-DAC microscopy at shallow depths. PMID:24322237

Wang, D; Chen, Y; Wang, Y; Liu, J T C

2013-12-15

324

Diffusion of photoacid generators by laser scanning confocal microscopy  

NASA Astrophysics Data System (ADS)

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.

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

1998-06-01

325

Innovative acoustic reflection imaging techniques and application to clinical breast tomography  

NASA Astrophysics Data System (ADS)

Conventional ultrasound techniques use beam-formed, constant sound speed ray models for fast image reconstruction. However, these techniques are inadequate for the emerging new field of ultrasound tomography (UST). We present a new technique for reconstruction of reflection images from UST data. We have extended the planar Kirchhoff migration method used in geophysics, and combined it with sound speed and attenuation data obtained from the transmission signals to create reflection ultrasound images that are corrected for refractive and attenuative effects. The resulting techniques were applied to simulated numerical phantom data, physical phantom data and in-vivo breast data obtained with an experimental ring transducer prototype. Additionally, the ring transducer was customized to test compatibility with an existing ultrasound workstation. We were able to obtain independently recorded radio-frequency (RF) data for individual transmit-receive pair combinations for all 128 transducers. The signal data was then successfully reconstructed into reflection data using the Kirchhoff migration techniques. The results from the use of sound speed and attenuation corrections lead to significant improvements in image quality, particularly in dense tissues where the refractive and scattering effects are the greatest. The procedure was applied to a variety of breast densities and masses of different natures. The resulting reflection images successfully resolved boundaries and textures. The reflection characteristics of tomographic ultrasound maintain an indispensible position in the quantification of proper mass identification. The results of this project indicate the clinical significance of the invocation of properly compensated Kirchhoff based reconstruction method with the use of sound speed and attenuation parameters for the visualization and classification of masses and tissue.

Schmidt, Steve P.

326

Confocal Examination of Nonmelanoma Cancers in Thick Skin Excisions to Potentially Guide Mohs Micrographic Surgery Without Frozen Histopathology  

Microsoft Academic Search

Precise removal of nonmelanoma cancers with minimum damage to the surrounding normal skin is guided by the histopathologic examination of each excision during Mohs micrographic surgery. The preparation of frozen histopathology sections typically requires 20–45 min per excision. Real-time confocal reflectance microscopy offers an imaging method potentially to avoid frozen histopathology and prepare noninvasive (optical) sections within 5 min. Skin

Milind Rajadhyaksha; Gregg Menaker; Thomas Flotte; Peter J. Dwyer; Salvador González

2001-01-01

327

Fiber-optic confocal probe with an integrated real-time apex finder for high-precision center thickness measurement of ball lenses  

NASA Astrophysics Data System (ADS)

This paper describes the development of a fiber-optic confocal probe suitable to measuring the central thickness of highcurvature small-diameter optical ball lenses. The confocal probe utilizes an integrated camera that functions as a realtime apex-sensing device. An additional camera is used to monitor the shape of the reflected light beam. Placing the instrument sensing spot off-center from the apex will produce a non-circular image at the camera plane that closely resembles an ellipse for small displacement. By analyzing the shape of the reflected light spot, we are able to precisely determine the focus point of the confocal probe relative to the apex point to better than 2-?m precision for ball lenses with diameters in the range of 3 - 10 mm. The proposed confocal probe offers a low-cost alternative technique for quality control of ball lenses during the manufacturing process.

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

2012-11-01

328

Confocal ?-XRF depth analysis of paint layers  

NASA Astrophysics Data System (ADS)

Focused narrow-band beam of the synchrotron radiation was used for in-depth analysis of historic and modern paint layers. The fluorescent radiation induced by 21 keV impact radiation was detected by a Si(Li) detector equipped with a polycapillary X-ray lens in con-focal geometry. Scanning of the sample was performed by a motorized x- y- z stage. Space resolution of 30 ?m was achieved. The procedure of evaluation of concentrations was based on the independent parameter method and included absorption of radiation in the outer layers and secondary fluorescence enhancement induced by hard X-rays of the same and neighboring layers.

Šmit, Ž.; Janssens, K.; Proost, K.; Langus, I.

2004-06-01

329

Detection limits of confocal surface plasmon microscopy  

PubMed Central

This paper applies rigorous diffraction theory to evaluate the minimum mass sensitivity of a confocal optical microscope designed to excite and detect surface plasmons operating on a planar metallic substrate. The diffraction model is compared with an intuitive ray picture which gives remarkably similar predictions. The combination of focusing the surface plasmons and accurate phase measurement mean that under favorable but achievable conditions detection of small numbers of molecules is possible, however, we argue that reliable detection of single molecules will benefit from the use of structured surfaces. System configurations needed to optimize performance are discussed.

Pechprasarn, Suejit; Somekh, Michael G.

2014-01-01

330

Apparatus for vectorial Kerr confocal microscopy.  

PubMed

We present a confocal microscopy setup that is able to record magneto-optical hysteresis cycles separating the in-plane and out-of-plane magnetization components. This apparatus is based on a modified commercial microscope, where the light beam has been deviated from the cylindrical symmetry axis of the objective lenses by inserting a translating plate in the optical path. The instrument allows for the magneto-optical imaging with a lateral resolution of 600 nm at ? = 635 nm light wavelength. PMID:21361603

Savoini, M; Ciccacci, F; Duò, L; Finazzi, M

2011-02-01

331

Interference Reflectance Microscopy  

PubMed Central

Interference Reflection microscopy is an optical technique used to study cell adhesion or cell mobility on a glass coverslip. The interference of reflected light waves generates images with high contrast and definition. IRM can be used to examine almost any cell that will rest upon a glass surface, although it is most useful in examining sites of close contact between a cell and substratum. This chapter presents methods for obtaining IRM images of cells with particular emphasis on IRM imaging with a laser scanning confocal microscope (LSCM), as most LSCM are already capable of recording these images without any modification of the instrument. Techniques are presented for imaging fixed and live cells as well as simultaneous multi-channel capture of fluorescence and reflection images.

Barr, Valarie A.; Bunnell, Stephen C.

2010-01-01

332

Interference reflection microscopy.  

PubMed

Interference reflection microscopy (IRM) is an optical technique used to study cell adhesion or cell mobility on a glass coverslip. The interference of reflected light waves generates images with high contrast and definition. IRM can be used to examine almost any cell that will rest upon a glass surface, although it is most useful in examining sites of close contact between a cell and substratum. This unit presents methods for obtaining IRM images of cells with particular emphasis on IRM imaging with a laser scanning confocal microscope (LSCM), as most LSCM are already capable of recording these images without any modification of the instrument. Techniques are presented for imaging fixed and live cells, as well as simultaneous multi-channel capture of fluorescence and reflection images. PMID:20013754

Barr, Valarie A; Bunnell, Stephen C

2009-12-01

333

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)

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.

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

1999-01-01

334

Cerium-based histochemical demonstration of oxidative stress in taurocholate-induced acute pancreatitis in rats. A confocal laser scanning microscopic study.  

PubMed

Direct in vivo histological detection of oxygen-derived free radicals (OFRs) in inflammatory conditions is not fully resolved. We report an application of cerium histochemistry (in which capture of OFRs by Ce atoms results in laser-reflectant cerium-perhydroxide precipitates) combined with reflectance confocal laser scanning microscopy (CLSM) to demonstrate the evolution of oxidative stress in taurocholate-induced acute pancreatitis (AP) in rats. Animals were perfused with CeCl(3) in vivo and cryostat sections of pancreata were studied by CLSM. Vascular endothelium was immunolabeled for PECAM-1. OFR production by isolated polymorphonuclear leukocytes (PMNs) incubated in vitro with CeCl(3) was quantified by image analysis. In the pancreas, strong OFR-derived cerium reflectance signals were seen in acinar cells at 1-2 hr, capillaries and small venules were frequently engorged by cerium precipitates, and adherent PMNs presented weak intracellular reflectance signals. At 8-24 hr, acinar cell OFR production decreased, whereas adherent/transmigrated PMNs displayed abundant intra- and pericellular reflectance. PECAM-1 expression was unchanged. PMNs from ascites or blood showed significant (p<0.01) time-dependent OFR production, plateauing from 2 hr. The modified cerium capture/CLSM method allows the co-demonstration of in vivo oxidative stress and cellular structures labeled with fluorescent markers. In vivo oxidative stress was shown histologically for the first time in experimental AP. PMID:10449541

Telek, G; Scoazec, J Y; Chariot, J; Ducroc, R; Feldmann, G; Roz, C

1999-09-01

335

In vivo confocal microscopy of congenital aniridia-associated keratopathy  

PubMed Central

Purpose To explore the in vivo morphological changes of cornea and limbus in aniridia-associated keratopathy (AAK). Methods Three cases of AAK were examined with the application of in vivo confocal microscopy (IVCM). Results Abnormal structure of wing and basal layer of epithelium, the loss of subbasal nerves, and the presence of goblet cells at central cornea could be identified in the most severe case, along with the absence of Vogt palisades. The less extent of abnormalities in corneal epithelial cells, subbasal nerve, and Vogt palisades were visible in the moderate or mild cases. Conclusions The morphological changes of cornea and limbus vary in AAK, and IVCM is a promising tool to determine the degree of limbal stem cell deficiency in patients with AAK.

Le, Q; Deng, S X; Xu, J

2013-01-01

336

Theoretical and experimental study on chromatic confocal position sensor  

NASA Astrophysics Data System (ADS)

In this paper, the chromatic confocal technique application in position measurement is studyed theoretically and experimentally. Firstly, a set of refractive lenses are designed and a position measurement device is established for this purpose. Then, calibration of wavelength-depth relationship has been performed. The calibration results accords with the theoretical design results well. Third, influence of the detector pinhole size on axial resolution of the measurement system is analyzed. It is clear from numerical simulation that the full width of half maximum (FWHM) of spectral distribution on the detector will increase with enlargement of pinhole size, which makes axial resolution decrease. The experiment results also disclose identical tendency. It can be concluded that the position measurement system can realize rapid position measurement with higher precision.

Niu, Chun-Hui; Deng, Wen-Yi; Mao, Xian-Hui; Gao, Xin; Han, Cong

2010-11-01

337

Application of Extended Inverse Scatter Correction to Mid-Infrared Reflectance Spectra of Soil  

SciTech Connect

Scattering artifacts adversely affect infrared reflectance measurements of powders and soils, and extended inverse scatter correction (EISC) is a flexible method useful for correcting for these artifacts. EISC was used to correct mid-infrared reflectance spectra of two different soils coated with dibutyl phosphate and the results were examined using regression analysis. To determine the correction, EISC fits a measured spectrum to a reference spectrum. However, if measured spectra contain features not included in the reference spectrum the fit can be biased resulting in poor correction. Weighted and robust least squares were used to account for these potential biases. Additionally, the present work demonstrates how analyte-free samples can be used to determine basis functions for an extended mixture model used in the correction. Corrected spectra resulted in partial least squares models that performed at least as well as 2nd derivative spectra and were more interpretable.

Gallagher, Neal B.; Blake, Thomas A.; Gassman, Paul L.

2005-05-01

338

An adaptive phase space method with application to reflection traveltime tomography  

NASA Astrophysics Data System (ADS)

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.

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

2011-11-01

339

Near-infrared reflectance spectra-applications to problems in asteroid-meteorite relationships  

NASA Technical Reports Server (NTRS)

Near-infrared spectral reflectance data were collected at the Infrared Telescope Facility (IRTF) at Mauna Kea Observatories in 1985 and 1986 for the purpose of searching the region near the 3:1 Kirkwood gap for asteroids with the spectral signatures of ordinary chondrite parent bodies. Twelve reflectance spectra are observed. The presence of ordinary chondrite parent bodies among this specific set of observed asteroids is not obvious, though the sample is biased towards the larger asteroids in the region due to limitations imposed by detector sensitivity. The data set, which was acquired with the same instrumentation used for the 52-color asteroid survey (Bell et al., 1987), also presents some additional findings. The range of spectral characteristics that exist among asteroids of the same taxonomic type is noted. Conclusions based on the findings are discussed.

Mcfadden, Lucy A.; Chamberlin, Alan; Vilas, Faith

1991-01-01

340

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

NASA Astrophysics Data System (ADS)

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.

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

2008-12-01

341

Application of transcutaneous diffuse reflectance spectroscopy in the measurement of blood glucose concentration  

NASA Astrophysics Data System (ADS)

In this paper, the propagation characteristics of near-infrared (NIR) light in the palm tissue are analyzed, and the principle and feasibility of using transcutaneous diffuse reflectance spectroscopy for non-invasive blood glucose detection are presented. An optical probe suitable for measuring the diffuse reflectance spectrum of human palm and a non-invasive blood glucose detection system using NIR spectroscopy are designed. Based on this system, oral glucose tolerance tests are performed to measure the blood glucose concentrations of two young healthy volunteers. The partial least square calibration model is then constructed by all individual experimental data. The final result shows that correlation coefficients of the two experiments between the predicted blood glucose concentrations and the reference blood glucose concentrations are 0.9870 and 0.9854, respectively. The root mean square errors of prediction of full cross validation are 0.54 and 0.52 mmol/l, respectively.

Chen, Wenliang; Liu, Rong; Cui, Houxin; Xu, Kexin; Lv, Lina

2004-07-01

342

A Context-Aware Reflective Middleware Framework for Adaptive Real-time Vehicle Applications  

Microsoft Academic Search

Software has become crucial to develop vehicle systems. Future unmanned intelligent vehicle safety systems will increasingly rely on situational contexts collected at runtime through temporally built ad-hoc and dynamic networks for vehicle-to-vehicle and vehicle-to-roadside communications and dynamic adaptation to the contexts to improve vehicle safety and reduce traffic congestion. Context-aware reflective middleware, which can measure real-time contexts and accordingly reconfigure

Shengpu Liu; Liang Cheng

343

Forensic application of total reflection X-ray fluorescence spectrometry for elemental characterization of ink samples  

Microsoft Academic Search

The possibility of applying Total Reflection X-ray Fluorescence for qualitative and quantitative differentiation of documents printed with rare earth tagged and untagged inks has been explored in this paper. For qualitative differentiation, a very small amount of ink was loosened from the printed documents by smoothly rubbing with a new clean blade without destroying the manuscript. 50?L of Milli-Q water

Sangita Dhara; N. L. Misra; S. D. Maind; Sanjukta A. Kumar; N. Chattopadhyay; S. K. Aggarwal

2010-01-01

344

Multivariate Data Analysis on Tissue Diffuse Reflectance Spectra for Diagnostic Applications  

NASA Astrophysics Data System (ADS)

Currently, clinical diagnosis of skin disease is generally accomplished by visual inspection under white light illumination. Aside from physical examination, the diagnosis of most of these lesions is invasive, time-consuming, and costly, often requiring surgical excision or biopsy followed by pathological investigations. Several approaches have been tried to improve dermatological diagnosis. Optical means of characterizing tissues have gained importance due to its noninvasive nature. Diffuse reflectance spectra are unique for normal and diseased tissues. Spectral characteristics of the tissue spectra provide useful information to identify various chromophores present in them, because different chromophores have different spectroscopic responses to electromagnetic waves of certain energy bands. An optical fiber spectrometer is set up for collection of diffuse reflectance data from different skin conditions. The method involves exposure of skin surface to white light produced by an incandescent source. These back scattered photons emerging from various layers of tissue are detected by spectrometer resulting in diffuse reflectance data. PCA can be considered as ``the mother of all methods in multivariate data analysis''. PCA is performed for data reduction and to obtain specific signature from the spectra to differentiate normal and the diseased skin. The proposed principal component analysis method is able to enhance the peculiar characteristics of the diseased diffuse reflectance spectra. Principal component analysis shows that the spectra from normal and diseased tissues are distinct from each other. PCA is recommended as an exploratory tool to uncover unknown trends in the data. A preliminary study, using PCA on the reparability of the spectra of normal and diseased tissue within each patient shows promise that this method is sensitive to changes in tissue brought upon by the onset of disease.

Prince, Shanthi; Malarvizhi, S.

2011-10-01

345

Matrix effects for reflectivity spectra of dispersed nanophase (superparamagnetic) hematite with application to Martian spectral data  

Microsoft Academic Search

The effect of the matrix on the reflectivity spectra of nanophase (superparamagnetic) hematite (np-Hm) dispersed within the matrix was investigated in four series of powder samples containing np-Hm dispersed within discrete powder particles (of two size ranges) of silica gel and activated alumina. The spectral data show that matrix effects are large. Samples with the same Fe2O3 content can have

Richard V. Morris; Howard V. Lauer

1990-01-01

346

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

NASA Astrophysics Data System (ADS)

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.

Louchard, Eric Michael

347

Confocal imaging of benign and malignant proliferative skin lesions in vivo  

NASA Astrophysics Data System (ADS)

Non-IR 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 micrometers 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.

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

1999-06-01

348

Ex vivo Confocal Imaging with Contrast Agents for the Detection of Oral Potentially Malignant Lesions  

PubMed Central

Objectives We investigated the potential use of real-time confocal microscpy in the non-invasive detection of occult oral potentially malignant lesions. Our objectives were to select the best fluorescence contrast agent for cellular morphology enhancement, to build an atlas of confocal microscopic images of normal human oral mucosa, and to determine the accuracy of confocal microscopy to recognise oral high-grade dysplasia lesions on live human tissue. Materials and Methods Five clinically used fluorescent contrast agents were tested in vitro on cultured human cells and validated ex vivo on human oral mucosa. Images acquired ex vivo from normal and diseased human oral biopsies with bench-top fluorescent confocal microscope were compared to conventional histology. Image analyzer software was used as an adjunct tool to objectively compare high-grade dysplasia versus low-grade dysplasia and normal epithelium. Results Acriflavine Hydrochloride provided the best cellular contrast by preferentially staining the nuclei of the epithelium. Using topical application of Acriflavine Hydrochloride followed by confocal microscopy, we could define morphological characteristics of each cellular layer of the normal human oral mucosa, building an atlas of histology-like images. Applying this technique to diseased oral tissue specimen, we were also able to accurately diagnose the presence of high-grade dysplasia through the increased cellularity and changes in nuclear morphological features. Objective measurement of cellular density by quantitative image analysis was a strong discriminant to differentiate between high-grade dysplasia and low-grade dysplasia lesions. Conclusions Pending clinical investigation, real-time confocal microscopy may become a useful adjunct to detect precancerous lesions that are at high risk of cancer progression, direct biopsy and delineate excision margins.

Hallani, S. El; Poh, C. F.; Macaulay, C. E.; Follen, M.; Guillaud, M.; Lane, P.

2013-01-01

349

Handheld confocal Raman microspectrometer for in-vivo skin cancer measurement  

NASA Astrophysics Data System (ADS)

Several studies have demonstrated Raman spectroscopy to be capable of tissue diagnosis with accuracy rivaling that of histopathologic analysis. This technique obtains biochemical-specific information noninvasively, and can eliminate the pain, time, and cost associated with biopsy and pathological analysis. Furthermore, when used in a confocal arrangement, Raman spectra can be obtained from localized regions of the tissue. Skin cancers are an ideal candidate for this emerging technology, due to their obvious accessibility and presentation at specific depths. However, most commercially available confocal Raman microspectrometers are large, rigid systems ill-suited for clinical application. We developed a bench-top confocal Raman microspectrometer using a portable external-cavity diode laser excitation source. This system was used to study several skin lesions in vitro. Results show the depth-resolved Raman spectra can diagnose in vitro skin lesions with 96% sensitivity, 88% specificity, and 86% pathological classification accuracy. Based on the success of this study, a portable Raman system with a handheld confocal microscope was developed for clinical application. Preliminary in vivo data show several distinct spectral differences between skin pathologies. Diagnostic algorithms are planned for this continuing study to assess the capability of Raman spectroscopy for clinical skin cancer diagnosis.

Lieber, Chad A.; Ellis, Darrel L.; Billheimer, D. D.; Mahadevan-Jansen, Anita

2004-07-01

350

Application of Attenuation Correction to Precipitation Rates Derived From Terminal Doppler Weather Radar Reflectivity  

NASA Astrophysics Data System (ADS)

The Federal Aviation Administration Terminal Doppler Weather Radars (TDWRs) are C band radars that offer high spatio-temporal resolution coverage over major urban areas in the United States. The National Oceanic and Atmospheric Administration, National Weather Service (NWS) has been investigating the incorporation of TDWR data for producing quantitative precipitation estimates to serve its flash and river forecast missions. As reflectivity from C-band Radars can be considerably attenuated by hydrometeors, the NWS Office of Hydrologic Development implemented an algorithm for mitigating this attenuation. In this algorithm, TDWR reflectivity is adjusted iteratively along each radial based on reflectivity and temperature data with the assumption of gamma distribution of drop size. This paper describes the concept and the implementation of the attenuation correction algorithm, and presents a series of validation case studies to examine the impacts of the correction on the accuracy of resulting radar-only QPEs during warm and cool season storm events. Serving as the validation reference is the Stage IV gauge-radar QPE produced by NWS. In order to determine the effects of ingesting spatially variable atmospheric temperature, spatially variable (3-dimensional) temperature from the Rapid Update Cycle 2 (RUC2) model is ingested, and the results are comparatively assessed along with those obtained using spatially averaged surface RUC2 temperatures. Finally, several atmospheric temperature thresholds were tested to avoid over-correction in cases with bright band enhancement. It was found that attenuation correction generally improved correlations between TDWR and StageIV precipitation estimates. The use of low-temperature cutoff criteria appeared effective in minimizing over-correction of attenuation within and beyond the bright band.

Zhang, Y.; Ding, F.; Kitzmiller, D. H.

2011-12-01

351

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

NASA Astrophysics Data System (ADS)

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.

Fixler, Dror

2014-02-01

352

Hematoporphyrin-mediated fluorescence reflectance imaging: application to early tumor detection in vivo in small animals.  

PubMed

The in vivo early detection of subcutaneous human tumors implanted in small animals was studied by laser-induced fluorescence reflectance imaging (FRI), with a hematoporphyrin (HP) compound as an exogenous optical contrast agent. Tumor detection was shown to be possible just 3 days after the inoculation of tumor cells, when tumors were neither visible nor palpable. However, this detection capability is limited to a temporal window of approximately 100 h from HP administration and to a low optical contrast of the tumor (<2). PMID:18324434

Autiero, Maddalena; Cozzolino, Rosanna; Laccetti, Paolo; Marotta, Marcello; Quarto, Maria; Riccio, Patrizia; Roberti, Giuseppe

2009-03-01

353

A Reflection on Reflection.  

ERIC Educational Resources Information Center

Reflects on the articles in this themed issue on reflective practice. Notes that these teacher/authors have been influenced by prior learning, past experience, feelings, attitudes, values, the school constraints on the learning environment, and their own assumptions about teaching. Describes how teachers have formed a learning community to…

Smith, Pat

2002-01-01

354

Usage of cornea and sclera back reflected images captured in security cameras for forensic and card games applications  

NASA Astrophysics Data System (ADS)

We present an approach allowing seeing objects that are hidden and that are not positioned in direct line of sight with security inspection cameras. The approach is based on inspecting the back reflections obtained from the cornea and the sclera of the eyes of people attending the inspected scene and which are positioned in front of the hidden objects we aim to image after performing proper calibration with point light source (e.g. a LED). The scene can be a forensic scene or for instance a casino in which the application is to see the cards of poker players seating in front of you.

Zalevsky, Zeev; Ilovitsh, Asaf; Beiderman, Yevgeny

2013-10-01

355

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

NASA Astrophysics Data System (ADS)

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.

Zaremba, Krzysztof

2008-06-01

356

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

NASA Astrophysics Data System (ADS)

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, sp3 fraction, ID/IG, 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.

Banerjee, Amit; Das, Debajyoti

2014-04-01

357

Simulation of attenuated total reflection infrared absorbance spectra: applications to automotive clear coat forensic analysis.  

PubMed

Attenuated total reflection (ATR) is a widely used sampling technique in infrared (IR) spectroscopy because minimal sample preparation is required. Since the penetration depth of the ATR analysis beam is quite shallow, the outer layers of a laminate or multilayered paint sample can be preferentially analyzed with the entire sample intact. For this reason, forensic laboratories are taking advantage of ATR to collect IR spectra of automotive paint systems that may consist of three or more layers. However, the IR spectrum of a paint sample obtained by ATR will exhibit distortions, e.g., band broadening and lower relative intensities at higher wavenumbers, compared with its transmission counterpart. This hinders library searching because most library spectra are measured in transmission mode. Furthermore, the angle of incidence for the internal reflection element, the refractive index of the clear coat, and surface contamination due to inorganic contaminants can profoundly influence the quality of the ATR spectrum obtained for automotive paints. A correction algorithm to allow ATR spectra to be searched using IR transmission spectra of the paint data query (PDQ) automotive database is presented. The proposed correction algorithm to convert transmission spectra from the PDQ library to ATR spectra is able to address distortion issues such as the relative intensities and broadening of the bands, and the introduction of wavelength shifts at lower frequencies, which prevent library searching of ATR spectra using archived IR transmission data. PMID:25014606

Lavine, Barry K; Fasasi, Ayuba; Mirjankar, Nikhil; Nishikida, Koichi; Campbell, Jay

2014-05-01

358

Performances for confocal X-ray diffraction technology based on polycapillary slightly focusing X-ray optics  

NASA Astrophysics Data System (ADS)

The confocal X-ray diffraction (XRD) technology based on a polycapillary slightly focusing X-ray lens (PSFXRL) in excitation channel and a polycapillary parallel X-ray lens (PPXRL) with a long input focal distance in detection channel was developed. The output focal spot of the PSFXRL and the input focal spot of the PPXRL were adjusted in confocal configuration, and only the X-rays from the volume overlapped by these foci could be accordingly detected. This confocal configuration was helpful in decreasing background. The convergence of the beam focused by the PSFXRL and divergence of the beam which could be collected by the PPXRL with a long input focal distance were both about 9 mrad at 8 keV. This was helpful in improving the resolution of lattice spacing of this confocal XRD technology. The gain in power density of such PSFXRL and PPXRL was about 120 and 7 at 11 keV, respectively, which was helpful in using the low power source to perform XRD analysis efficiently. The performances of this confocal XRD technology were provided, and some common plastics were analyzed. The experimental results demonstrated that the confocal diffraction technology base on polycapillary slightly focusing X-ray optics had wide potential applications.

Liu, Hehe; Liu, Zhiguo; Sun, Tianxi; Peng, Song; Ma, Yongzhong; Sun, Weiyuan; Li, Yude; Lin, Xiaoyan; Zhao, Weigang; Zhao, Guangcui; Luo, Ping; Pan, Qiuli; Ding, Xunliang

2013-09-01

359

Video-rate confocal scanning laser microscope for imaging human tissues {ital in vivo}  

SciTech Connect

We have built a video-rate confocal scanning laser microscope for reflectance imaging of human skin and oral mucosa {ital in vivo}. Design and imaging parameters were determined for optimum resolution and contrast. Mechanical skin-holding fixtures and oral tissue clamps were made for stable objective lens-to-tissue contact such that gross tissue motion relative to the microscope was minimized. Confocal imaging was possible to maximum depths of 350 {mu}m in human skin and 450 {mu}m in oral mucosa, with measured lateral resolution of 0.5{endash}1 {mu}m and axial resolution (section thickness) of 3{endash}5 {mu}m at the 1064-nm wavelength. This resolution is comparable with that of conventional microscopy of excised biopsies (histology). Normal and abnormal tissue morphology and dynamic processes were observed. {copyright} 1999 Optical Society of America

Rajadhyaksha, M.; Anderson, R.R.; Webb, R.H. [Department of Dermatology, Wellman Laboratories, Massachusetts General Hospital, Bartlett Hall Ext. 630, 50 Blossom Street, Boston, Massachusetts 02114 (United States)

1999-04-01

360

Visualizing Cochlear Mechanics Using Confocal Microscopy  

NASA Astrophysics Data System (ADS)

The sound-evoked vibration pattern of the hearing organ is based on complex mechanical interactions between different cellular structures. To explore the structural changes occurring within the organ of Corti during basilar-membrane motion, stepwise alterations of the scala tympani pressure were applied in an in vitro preparation of the guinea-pig temporal bone. Confocal images were acquired at each pressure level. In this way, the motion of several structures could be simultaneously observed with high resolution in a nearly intact system. Images were analyzed using a novel wavelet-based optical-flow estimation algorithm. Under the present experimental conditions, the reticular lamina moved as a stiff plate with a center of rotation in the region of the inner hair cells. The outer hair cells appeared non-rigid and the basal, synaptic regions of these cells displayed significant radial motion indicative of cellular bending and internal shearing.

Ulfendahl, M.; Boutet de Monvel, J.; Fridberger, A.

2003-02-01

361

Fluorescence confocal endomicroscopy in biological imaging  

NASA Astrophysics Data System (ADS)

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.

Delaney, Peter; Thomas, Steven; Allen, John; McLaren, Wendy; Murr, Elise; Harris, Martin

2007-03-01

362

Three-dimensional scanning confocal laser microscope  

DOEpatents

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.

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

1999-01-01

363

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

NASA Technical Reports Server (NTRS)

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.

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

2012-01-01

364

Simultaneous Confocal Scanning Laser Ophthalmoscopy Combined with High-Resolution Spectral-Domain Optical Coherence Tomography: A Review  

PubMed Central

We aimed to evaluate technical aspects and the clinical relevance of a simultaneous confocal scanning laser ophthalmoscope and a high-speed, high-resolution, spectral-domain optical coherence tomography (SDOCT) device for retinal imaging. The principle of confocal scanning laser imaging provides a high resolution of retinal and choroidal vasculature with low light exposure. Enhanced contrast, details, and image sharpness are generated using confocality. The real-time SDOCT provides a new level of accuracy for assessment of the angiographic and morphological correlation. The combined system allows for simultaneous recordings of topographic and tomographic images with accurate correlation between them. Also it can provide simultaneous multimodal imaging of retinal pathologies, such as fluorescein and indocyanine green angiographies, infrared and blue reflectance (red-free) images, fundus autofluorescence images, and OCT scans (Spectralis HRA?+?OCT; Heidelberg Engineering, Heidelberg, Germany). The combination of various macular diagnostic tools can lead to a better understanding and improved knowledge of macular diseases.

Castro Lima, Veronica; Rodrigues, Eduardo B.; Nunes, Renata P.; Sallum, Juliana F.; Farah, Michel E.; Meyer, Carsten H.

2011-01-01

365

Temperature dependence of silicon carrier effective masses with application to femtosecond reflectivity measurements  

NASA Astrophysics Data System (ADS)

The conductivity effective masses of electrons and holes in Si are calculated for carrier temperatures from 1 to 3000 K. The temperature dependence of the electron mass is calculated by use of a phenomenological model of conduction-band nonparabolicity that has been fitted to experimental measurements of the dependence of the electron conductivity effective mass on carrier concentration. The hole mass is investigated by tight-binding calculations of the valence bands, which have been adjusted to match experimental values of the valence-band curvature parameters at the top of the valence band. The calculations are in excellent agreement with femtosecond-laser reflectivity measurements of the change in optical effective mass as hot carriers cool from 1550 to 300 K.

Riffe, D. M.

2002-05-01

366

Matrix effects for reflectivity spectra of dispersed nanophase (superparamagnetic) hematite with application to Martian spectral data  

NASA Astrophysics Data System (ADS)

The effect of the matrix on the reflectivity spectra of nanophase (superparamagnetic) hematite (np-Hm) dispersed within the matrix was investigated in four series of powder samples containing np-Hm dispersed within discrete powder particles (of two size ranges) of silica gel and activated alumina. The spectral data show that matrix effects are large. Samples with the same Fe2O3 content can have np-Hm absorption edges characterized by very different positions and curvature and slope indices, while samples with equivalent absorption edges can have very different Fe2O3 concentrations. Thus, quantitative relationships between the positions of ferric absorption edges and Fe2O3 concentrations are unreliable without knowledge of matrix properties of the system. It is shown that it was possible to match the Fe2O3 concentration, magnetic properties, and spectral data for Martian surface material with a laboratory mixture whose only ferric-bearing phase was hematite.

Morris, R. V.; Lauer, H. V.

1990-04-01

367

[Quantitative analysis of contents in compound fertilizer and application research using near infrared reflectance spectroscopy].  

PubMed

In the present study, a new approach to fast determining the content of urea, biuret and moisture in compound fertilizer composed of urea, ammonium dihydrogenphosphate and potassium chloride was proposed by using near infrared diffuse reflectance spectroscopy. After preprocessing the original spectrum, partial least squares (PLS) models of urea, biuret and moisture were built with the R2 values of 0.9861, 0.9770 and 0.9713 respectively, the root mean square errors of cross validation were 2.59, 0.38, 0.132 respectively. And the prediction correlation factors were 0.9733, 0.9215 and 0.9679 respectively. The authors detected six kinds of compound fertilizer in market for the model verification, the correlation factors were 0.9237, 0.9786 and 0.9874 respectively. The data implied that the new method can be used for situ quality control in the production process of compound fertilizer. PMID:24783536

Song, Le; Zhang, Hong; Ni, Xiao-Yu; Wu, Lin; Liu, Bin-Mei; Yu, Li-Xiang; Wang, Qi; Wu, Yue-Jin

2014-01-01

368

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

NASA Astrophysics Data System (ADS)

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.

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

2008-12-01

369

First application of proton reflection magnetometry with MESSENGER to estimate Mercury's surface magnetic field strength (Invited)  

NASA Astrophysics Data System (ADS)

We present the first use of proton reflection magnetometry, a novel adaptation of electron reflectometry, to estimate Mercury's surface field strength. We use measurements of protons by MESSENGER's Fast Imaging Plasma Spectrometer (FIPS) in 8-s integration times. Because of the limited field of view of FIPS, we average pitch-angle distributions by accumulating proton data from multiple integration periods and orbits over selected geographical regions. Proton loss cones are evident in both the northern hemisphere cusp region as well as on the nightside at low latitudes in the southern hemisphere. The existence of the loss cones provides confirmation of proton precipitation to the surface in these regions. The loss cone pitch-angle cut-offs are gradual rather than sharp, which we attribute in part to wave-particle scattering causing pitch-angle diffusion. Fitting diffusion curves to the pitch-angle distributions yields estimates of both the cut-off pitch angle, ?c, and an average D?t, where D? is the pitch-angle diffusion coefficient and t is the diffusion time. The in-situ magnetic field together with ?c provide an estimate of the surface magnetic field strength. The results are within 10% of a magnetospheric model for the surface field at the mapped surface locations, but are systematically lower than the model predictions. This discrepancy is consistent with the presence of near-surface plasma, which locally lowers the actual total magnetic field at the surface but is not included in the vacuum-field magnetospheric model. As consistency checks, we have confirmed that the loss cone size decreases with increasing altitude and that the surface magnetic field strength increases with increasing latitude. Our results confirm the offset dipole structure at the surface and demonstrate that proton reflection magnetometry is a practical method for inferring the surface magnetic field strength at Mercury. Further observations may resolve regional-scale structure in the surface planetary field.

Winslow, R. M.; Johnson, C. L.; Anderson, B. J.; Gershman, D. J.; Raines, J. M.; Lillis, R. J.; Korth, H.; Slavin, J. A.; Solomon, S. C.

2013-12-01

370

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

PubMed

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

Blum, Marc-Michael; John, Harald

2012-01-01

371

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

NASA Astrophysics Data System (ADS)

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.

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

2014-02-01

372

[32] Identification of viral infection by confocal microscopy  

Microsoft Academic Search

Confocal microscopy is a valuable adjunct to electron microscopy in the fields of diagnostic and investigative virology. Confocal imaging can be used to examine large amounts of tissue stained by a variety of methods for evidence of viral infection. Areas thus identified can then be processed for ultrastructural study, allowing a highly focused search for viral pathogens. With the possible

David N. Howell; Sara E. Miller

1999-01-01

373

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...

374

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...

375

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

PubMed

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

Muñoz Morales, Aarón A; Vázquez Y Montiel, Sergio

2012-10-01

376

Application of ZnO Single Crystal Rods as Anti-Reflective Material for PV Cells  

Microsoft Academic Search

In this study, ZnO nanorods for antireflection coatings application to the silicon solar cells were epitaxially grown over the Si substrate using both thermal evaporation method and wet chemical method and their characteristics were investigated. A precursor for the thermal evaporation method was prepared by impregnating zinc acetate over the activated carbon at three different loading amounts: 10, 20, and

No-Kuk Park; Yong Sul Kim; Jun Hyuk Chang; Do Hyeong Kim; Si Ok Ryu; Tae Jin Lee; Heun Duk Kim; Won Gun Lee

2012-01-01

377

Robust approaches to quantitative ratiometric FRET imaging of CFP/YFP fluorophores under confocal microscopy  

PubMed Central

SUMMARY Ratiometric quantification of CFP/YFP FRET enables live-cell time-series detection of molecular interactions, without the need for acceptor photobleaching or specialized equipment for determining fluorescence lifetime. Though popular in widefield applications, its implementation on a confocal microscope, which would enable subcellular resolution, has met with limited success. Here, we characterize sources of optical variability (unique to the confocal context) which diminish the accuracy and reproducibility of ratiometric FRET determination, and devise practical remedies. Remarkably, we find that the most popular configuration, which pairs an oil objective with a small pinhole aperture, results in intractable variability that could not be adequately corrected through any calibration procedure. By quantitatively comparing several imaging configurations and calibration procedures, we find that significant improvements can be achieved by combining a water objective and increased pinhole aperture with a uniform-dye calibration procedure. The combination of these methods permitted remarkably consistent quantification of subcellular FRET in live cells. Notably, this methodology can be readily implemented on a standard confocal instrument, and the dye calibration procedure yields a time savings over traditional live-cell calibration methods. In all, identification of key technical challenges and practical compensating solutions promise robust subcellular ratiometric FRET imaging under confocal microscopy.

Tadross, Michael R.; Park, Sarah A.; Veeramani, Balaji; Yue, David T.

2010-01-01

378

Robust approaches to quantitative ratiometric FRET imaging of CFP/YFP fluorophores under confocal microscopy.  

PubMed

Ratiometric quantification of CFP/YFP FRET enables live-cell time-series detection of molecular interactions, without the need for acceptor photobleaching or specialized equipment for determining fluorescence lifetime. Although popular in widefield applications, its implementation on a confocal microscope, which would enable sub-cellular resolution, has met with limited success. Here, we characterize sources of optical variability (unique to the confocal context) that diminish the accuracy and reproducibility of ratiometric FRET determination and devise practical remedies. Remarkably, we find that the most popular configuration, which pairs an oil objective with a small pinhole aperture, results in intractable variability that could not be adequately corrected through any calibration procedure. By quantitatively comparing several imaging configurations and calibration procedures, we find that significant improvements can be achieved by combining a water objective and increased pinhole aperture with a uniform-dye calibration procedure. The combination of these methods permitted remarkably consistent quantification of sub-cellular FRET in live cells. Notably, this methodology can be readily implemented on a standard confocal instrument, and the dye calibration procedure yields a time savings over traditional live-cell calibration methods. In all, identification of key technical challenges and practical compensating solutions promise robust sub-cellular ratiometric FRET imaging under confocal microscopy. PMID:19196425

Tadross, M R; Park, S A; Veeramani, B; Yue, D T

2009-01-01

379

Quantification of confocal images of biofilms grown on irregular surfaces.  

PubMed

Bacterial biofilms grow on many types of surfaces, including flat surfaces such as glass and metal and irregular surfaces such as rocks, biological tissues and polymers. While laser scanning confocal microscopy can provide high-resolution images of biofilms grown on any surface, quantification of biofilm-associated bacteria is currently limited to bacteria grown on flat surfaces. This can limit researchers studying irregular surfaces to qualitative analysis or quantification of only the total bacteria in an image. In this work, we introduce a new algorithm called modified connected volume filtration (MCVF) to quantify bacteria grown on top of an irregular surface that is fluorescently labeled or reflective. Using the MCVF algorithm, two new quantification parameters are introduced. The modified substratum coverage parameter enables quantification of the connected-biofilm bacteria on top of the surface and on the imaging substratum. The utility of MCVF and the modified substratum coverage parameter were shown with Pseudomonas aeruginosa and Staphylococcus aureus biofilms grown on human airway epithelial cells. A second parameter, the percent association, provides quantified data on the colocalization of the bacteria with a labeled component, including bacteria within a labeled tissue. The utility of quantifying the bacteria associated with the cell cytoplasm was demonstrated with Neisseria gonorrhoeae biofilms grown on cervical epithelial cells. This algorithm provides more flexibility and quantitative ability to researchers studying biofilms grown on a variety of irregular substrata. PMID:24632515

Sommerfeld Ross, Stacy; Tu, Mai Han; Falsetta, Megan L; Ketterer, Margaret R; Kiedrowski, Megan R; Horswill, Alexander R; Apicella, Michael A; Reinhardt, Joseph M; Fiegel, Jennifer

2014-05-01

380

Confocal Fabry-Perot interferometer based high spectral resolution lidar  

NASA Astrophysics Data System (ADS)

A high spectral resolution lidar (HSRL) instrument has been developed which utilizes the fundamental and second harmonic output from an injection seeded Nd:YAG laser as the laser transmitter. The light scattered in the atmosphere is collected using a commercial Schmidt-Cassegrain telescope. The second harmonic return signal is mode matched into a tunable confocal Fabry-Perot (CFP) interferometer with a free spectral range of 7.5 GHz and a finesse of 50.7 (312) at 532 nm (1064 nm) placed in the optical receiver for spectrally filtering the molecular and aerosol return signals. The light transmitted through the CFP is used to monitor the aerosol return signal while the light reflected from the CFP is used to monitor the molecular return signal. Data collected with the HSRL are presented and inversion results are compared to a co-located solar radiometer, demonstrating the successful operation of the instrument. The CFP-based filtering technique successfully employed by this HSRL instrument is novel, and is easily portable to other arbitrary wavelengths, thus allowing for the future development of multi-wavelength HSRL instruments.

Hoffman, David Swick

381

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

PubMed

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

Moore, Carmelle

2012-12-01

382

Near infrared reflectance spectra: Applications to problems in asteroid-meteorite relationships  

NASA Technical Reports Server (NTRS)

An observing program designed to search for evidence of ordinary chondrite parent bodies near the 3:1 Kirkwood Gap was carried out in 1985 and 1986. Studies by Wisdom (1985), Wetherill (1985), and subsequent work by Milani et al. (1989) indicate that the 3:1 Kirkwood gap is the most probable source region for the majority of ordinary chondrite meteorites. The diversity of the reflectance spectra among this small data set is surprising. Early work by Gaffey and McCord (1978) showed that the inner region of the main asteroid belt is dominated by high albedo objects with mafic silicate surfaces. One would expect to see mostly spectra with 1- and 2-micron absorption bands based on this earlier work. Only 5 (of 12) spectra have these expected features. The distribution of taxonomic types presented by Gradie and Tedesco (1982) is in most cases a useful simplification of the compositional structure of the asteroid belt. The range of spectral characteristics seen with higher resolution in the near-IR has not been previously reported and is not represented in the standard asteroid taxonomy. Near-IR spectra contain valuable mineralogical information which enhances knowledge of the composition and structure of asteroids.

Mcfadden, Lucy A.; Chamberlin, Alan B.

1992-01-01

383

Bidirectional Reflectance of a Macroscopically Flat, High-Albedo Particulate Surface: An Efficient Radiative Transfer Solution and Applications to Regoliths  

NASA Technical Reports Server (NTRS)

Many remote sensing applications rely on accurate knowledge of the bidirectional reflection function (BRF) of surfaces composed of discrete, randomly positioned scattering particles. Theoretical computations of BRFs for plane-parallel particulate layers are usually reduced to solving the radiative transfer equation (RTE) using one of existing exact or approximate techniques. Since semi-empirical approximate approaches are notorious for their low accuracy, violation of the energy conservation law, and ability to produce unphysical results, the use of numerically exact solutions of RTE has gained justified popularity. For example, the computation of BRFs for macroscopically flat particulate surfaces in many geophysical publications is based on the adding-doubling (AD) and discrete ordinate (DO) methods. A further saving of computer resources can be achieved by using a more efficient technique to solve the plane-parallel RTE than the AD and DO methods. Since many natural particulate surfaces can be well represented by the model of an optically semi-infinite, homogeneous scattering layer, one can find the BRF directly by solving the Ambartsumian's nonlinear integral equation using a simple iterative technique. In this way, the computation of the internal radiation field is avoided and the computer code becomes highly efficient and very accurate and compact. Furthermore, the BRF thus obtained fully obeys the fundamental physical laws of energy conservation and reciprocity. In this paper, we discuss numerical aspects and the computer implementation of this technique, examine the applicability of the Henyey-Greenstein phase function and the sigma-Eddington approximation in BRF and flux calculations, and describe sample applications demonstrating the potential effect of particle shape on the bidirectional reflectance of flat regolith 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, and can be applied to a wide range of remote sensing problems. BRF computations for undulated (macroscopically rough) surfaces are more complicated and often rely on time consuming Monte Carlo procedures. This approach is especially inefficient for optically thick, weakly absorbing media (e.g., snow and desert surfaces at visible wavelengths since a photon may undergo many internal scattering events before it exists the medium or is absorbed. However, undulated surfaces can often be represented as collections of locally flat tilted facets characterized by the BRF found from the traditional plane parallel RTE. In this way the MOnte Carlo procedure could be used only to evaluate the effects of surface shadowing and multiple surface reflections, thereby bypassing the time-consuming ray tracing inside the medium and providing a great savings of CPU time.

Mishchenko, Michael I.; Zakharova, Nadia T.

1999-01-01

384

High speed unsupervised fluorescence lifetime imaging confocal multiwell plate reader for high content analysis.  

PubMed

We report an automated optically sectioning fluorescence lifetime imaging (FLIM) multiwell plate reader for high content analysis (HCA) in drug discovery and accelerated research in cell biology. The system utilizes a Nipkow disc confocal microscope and performs unsupervised FLIM with autofocus, automatic setting of acquisition parameters and automated localisation of cells in the field of view. We demonstrate its applications to test dye solutions, fixed and live cells and FLIM-FRET. PMID:19343677

Talbot, Clifford B; McGinty, James; Grant, David M; McGhee, Ewan J; Owen, Dylan M; Zhang, Wei; Bunney, Tom D; Munro, Ian; Isherwood, Beverly; Eagle, Rob; Hargreaves, Andre; Dunsby, Chris; Neil, Mark A A; French, Paul M W

2008-12-01

385

Full-field transmission x-ray imaging with confocal polycapillary x-ray optics  

PubMed Central

A transmission x-ray imaging setup based on a confocal combination of a polycapillary focusing x-ray optic followed by a polycapillary collimating x-ray optic was designed and demonstrated to have good resolution, better than the unmagnified pixel size and unlimited by the x-ray tube spot size. This imaging setup has potential application in x-ray imaging for small samples, for example, for histology specimens.

Sun, Tianxi; MacDonald, C. A.

2013-01-01

386

Full-field transmission x-ray imaging with confocal polycapillary x-ray optics  

NASA Astrophysics Data System (ADS)

A transmission x-ray imaging setup based on a confocal combination of a polycapillary focusing x-ray optic followed by a polycapillary collimating x-ray optic was designed and demonstrated to have good resolution, better than the unmagnified pixel size and unlimited by the x-ray tube spot size. This imaging setup has potential application in x-ray imaging for small samples, for example, for histology specimens.

Sun, Tianxi; MacDonald, C. A.

2013-02-01

387

Full-field transmission x-ray imaging with confocal polycapillary x-ray optics.  

PubMed

A transmission x-ray imaging setup based on a confocal combination of a polycapillary focusing x-ray optic followed by a polycapillary collimating x-ray optic was designed and demonstrated to have good resolution, better than the unmagnified pixel size and unlimited by the x-ray tube spot size. This imaging setup has potential application in x-ray imaging for small samples, for example, for histology specimens. PMID:23460760

Sun, Tianxi; Macdonald, C A

2013-02-01

388

Use of confocal laser scanning microscopy (CLSM) for depthwise resolved microscale-particle image velocimetry ( ?-PIV)  

Microsoft Academic Search

A novel use of confocal laser scanning microscopy (CLSM) makes the truly focused field-of-view with well-defined depthwise resolution possible for microscale particle image velocimetry (?-PIV) applications. The operating principle of the CLSM is presented using the point spread function (PSF) that describes diffracted images of extremely small particles. The implemented high-speed CLSM system using a Nipkow rotating disk is applied

J. S. Park; K. D. Kihm

2006-01-01

389

Axial super resolution topography of focal adhesion by confocal microscopy.  

PubMed

The protein organization within focal adhesions has been studied by state-of-the-art super resolution methods because of its thin structure, well below diffraction limit. However, to achieve high axial resolution, most of the current approaches rely on either sophisticated optics or diligent sample preparation, limiting their application. In this report we present a phasor-based method that can be applied to fluorescent samples to determine the precise axial position of proteins using a conventional confocal microscope. We demonstrate that with about 4,000 photon counts collected along a z-scan, axial localization precision close to 10 nm is achievable. We show that, with within 10 nm, the axial location of paxillin, FAK, and talin is similar at focal adhesion sites, while F-actin shows a sharp increase in height towards the cell center. We further demonstrated the live imaging capability of this method. With the advantage of simple data acquisition and no special instrument requirement, this approach could have wide dissemination and application potentials. PMID:23897846

Chiu, Chi-Li; Gratton, Enrico

2013-10-01

390

Development of optical fiber Bragg grating force-reflection sensor system of medical application for safe minimally invasive robotic surgery  

NASA Astrophysics Data System (ADS)

Force feedback plays a very important role in medical surgery. In minimally invasive surgery (MIS), however, the very long and stiff bars of surgical instruments greatly diminish force feedback for the surgeon. In the case of minimally invasive robotic surgery (MIRS), force feedback is totally eliminated. Previous researchers have reported that the absence of force feedback increased the average force magnitude applied to the tissue by at least 50%, and increased the peak force magnitude by at least a factor of two. Therefore, it is very important to provide force information in MIRS. Recently, many sensors are being developed for MIS and MIRS, but some obstacles to their application in actual medical surgery must be surmounted. The most critical problems are size limit and sterilizability. Optical fiber sensors are among the most suitable sensors for the surgical environment. The optical fiber Bragg grating (FBG) sensor, in particular, offers an important additional advantage over other optical fiber sensors in that it is not influenced by the intensity of the light source. In this paper, we present the initial results of a study on the application of a FBG sensor to measure reflected forces in MIRS environments and suggest the possibility of successful application to MIRS systems.

Song, Hoseok; Kim, Kiyoung; Lee, Jungju

2011-07-01

391

Miniature injection-molded optics for fiber-optic, in vivo confocal microscopy  

NASA Astrophysics Data System (ADS)

In collaboration with the Department of Biomedical Engineering at the University of Texas at Austin and the UT MD Anderson Cancer Center, a laser scanning fiber confocal reflectance microscope (FCRM) system has been designed and tested for in vivo detection of cervical and oral pre-cancers. This system along with specially developed diagnosis algorithms and techniques can achieve an unprecedented specificity and sensitivity for the diagnosis of pre-cancers in epithelial tissue. The FCRM imaging system consists of an NdYAG laser (1064 nm), scanning mirrors/optics, precision pinhole, detector, and an endoscopic probe (the objective). The objective is connected to the rest of the imaging system via a fiber bundle. The fiber bundle allows the rest of the system to be remotely positioned in a convenient location. Only the objective comes into contact with the patient. It is our intent that inexpensive mass-produced disposable endoscopic probes would be produced for large clinical trials. This paper touches on the general design process of developing a miniature, high numerical aperture, injection-molded (IM) objective. These IM optical designs are evaluated and modified based on manufacturing and application constraints. Based on these driving criteria, one specific optical design was chosen and a detailed tolerance analysis was conducted. The tolerance analysis was custom built to create a realistic statistical analysis for integrated IM lens elements that can be stacked one on top of another using micro-spheres resting in tiny circular grooves. These configurations allow each lens element to be rotated and possibly help compensate for predicted manufacturing errors. This research was supported by a grant from the National Institutes of Health (RO1 CA82880). Special thanks go to Applied Image Group/Optics for the numerous fabrication meetings concerning the miniature IM objective.

Chidley, Matthew D.; Liang, Chen; Descour, Michael R.; Sung, Kung-Bin; Richards-Kortum, Rebecca R.; Gillenwater, Ann

2002-12-01

392

Confocal Microscopy of Unfixed Breast Needle Core Biopsies: A Comparison to Fixed and Stained Sections  

PubMed Central

Background Needle core biopsy, often in conjunction with ultrasonic or stereotactic guided techniques, is frequently used to diagnose breast carcinoma in women. Confocal scanning laser microscopy (CSLM) is a technology that provides real-time digital images of tissues with cellular resolution. This paper reports the progress in developing techniques to rapidly screen needle core breast biopsy and surgical specimens at the point of care. CSLM requires minimal tissue processing and has the potential to reduce the time from excision to diagnosis. Following imaging, specimens can still be submitted for standard histopathological preparation. Methods Needle core breast specimens from 49 patients were imaged at the time of biopsy. These lesions had been characterized under the Breast Imaging Reporting And Data System (BI-RADS) as category 3, 4 or 5. The core biopsies were imaged with the CSLM before fixation. Samples were treated with 5% citric acid and glycerin USP to enhance nuclear visibility in the reflectance confocal images. Immediately following imaging, the specimens were fixed in buffered formalin and submitted for histological processing and pathological diagnosis. CSLM images were then compared to the standard histology. Results The pathologic diagnoses by standard histology were 7 invasive ductal carcinomas, 2 invasive lobular carcinomas, 3 ductal carcinomas in-situ (CIS), 21 fibrocystic changes/proliferative conditions, 9 fibroadenomas, and 5 other/benign; two were excluded due to imaging difficulties. Morphologic and cellular features of benign and cancerous lesions were identified in the confocal images and were comparable to standard histologic sections of the same tissue. Conclusion CSLM is a technique with the potential to screen needle core biopsy specimens in real-time. The confocal images contained sufficient information to identify stromal reactions such as fibrosis and cellular proliferations such as intra-ductal and infiltrating carcinoma, and were comparable to standard histologic sections of the same tissue. Morphologic and cellular features of benign and cancerous lesions were identified in the confocal images. Additional studies are needed to 1.) establish correlation of the confocal and traditional histologic images for the various diseases of the breast; 2.) validate diagnostic use of CSLM and; 3.) further define features of borderline lesions such as well-differentiated ductal CIS vs. atypical hyperplasia.

2009-01-01

393

Transmission confocal microscopy: making it a reality  

NASA Astrophysics Data System (ADS)

Imaging thick specimens in 3D transmission confocal modes presents two key problems. The first problem is variable aberrations introduced by changes in refractive index. The second problem is revealed when visualizing acquired data, where thick 3D datasets are difficult to interpret. In this paper we present our emerging solutions to these problems. Aberrations can be classified as simple tip-tilt deflection of the beam, or more complicated higher order aberrations. We discuss our results which demonstrate successful on-the- fly detection and correction for tip-tilt. For detecting higher order aberrations, we have chosen to investigate the wavefront curvature sensing technique. The second problem of rendering thick 3D datasets can be solved by extracting features of interest from the background. Simple intensity thresholding is not sufficient for complex biological specimens. And image processing in only 2D neglects any 3D structure. Use of Kohonen's self-organizing map neural network in 3D results in clear segmentation of features for sample chromosome specimens.

Arnison, Matthew R.; Fekete, Pal W.; Serrano, Marcos; Nguyen, Phuong T. A.; Romagnoli, Raniero; Guan, Ling; O'Byrne, John W.; Cogswell, Carol J.

1998-06-01

394

Reflective Writing  

NSDL National Science Digital Library

Your students successfully completed a lab session, correctly filled in all of the worksheets,and collected the required data. Yet, as a science teacher, you still find yourself wondering--what did my students actually learn? And, can they apply that learning to what is going on in their everyday lives? The process of critical thinking and knowledge application requires more than rote memorization and the ability to get answers correct on lab reports or multiple-choice tests. Purposeful, guided reflection may be an opportunity to gain insight into what students are thinking and learning in relation to science content. This article describes how to use guided reflective writing in the science classroom to provide a window into students' minds.

Mcdonald, James; Dominquez, Lynn

2009-03-01

395

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

NASA Astrophysics Data System (ADS)

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.

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

2012-06-01

396

Full-field chromatic confocal surface profilometry employing DMD correspondence for minimizing lateral cross talks  

NASA Astrophysics Data System (ADS)

In the research, full-field chromatic confocal surface profilometry employing digital micro-mirror device (DMD) for spatial correspondence is proposed to minimize lateral cross talks between individual detection sensors. Although fullfield chromatic confocal profilometry is capable of enhancing measurement efficiency by completely removing timeconsuming vertical scanning operation, its vertical measurement resolution and accuracy are still severely affected by the potential sensor cross talk problem. To overcome this critical bottleneck, a DMD-based chromatic confocal method is developed by employing a specially-designed objective for chromatic light dispersion and a DMD for lateral pixel correspondence and scanning. Using the chromatic objective, the incident light is dispersed according to a pre-designed detection range from a few micrometers to several millimeters and a full-field reflected light is captured by a three-chip color camera for multi color detection. Using this method, the full width half maximum (FWHM) of the depth response curve can be significantly sharpened, thus improving the vertical measurement resolution and repeatability of the depth detection. From our preliminary experimental evaluation, it is verified that the +/-3? repeatability of the height measurement can be kept within 2% of the overall measurement range.

Chen, Liang-Chia; Li, Hau-Wei; Chang, Yi-Wei

2011-08-01

397

Interference Phenomena Observed on an Atomic Force Microscope Cantilever by Laser Confocal Microscopy  

NASA Astrophysics Data System (ADS)

We investigated interference phenomena that were observed on a cantilever bar of an atomic force microscope by using a laser confocal microscope (LCM). First, we established a simple model and calculated the fringe interval. Interference fringe patterns were observed under the following conditions: (1) changing the focus and confocal aperture of the LCM, (2) increasing the reflectance by sputtering TiO2 on the cantilever bar and glass plate, and (3) changing the medium from air to water in the space between the glass plate and the cantilever. The purpose of a previous experiment was to measure the refractive index of water. It was theoretically determined that the fringe interval depended not on the height of the cantilever from the surface but on the wavelength, refractive index, and tilt angle of the cantilever. We obtained the following experimental results: (1) the fringe interval was independent of the confocal plane when using a monochromatic laser, (2) a sharpened interference fringe was observed when we used a TiO2-coated cantilever and glass plate, and (3) the refractive index of a small quantity of water could be measured.

Yanagiya, Shin-ichiro; Goto, Nobuo

2011-08-01

398

Highly reflective thin film coatings for high power applications of micro scanning mirrors in the NIR-VIS-UV spectral region  

Microsoft Academic Search

This paper addresses different highly reflective optical coatings on micro scanning mirrors (MSM) for applications in the NIR-VIS-UV-spectral region to enable new applications at high optical power density like laser marking and material treatment. In the common case of MSM with an unprotected Al coating, the absorption limits the maximal power density because of induced heating. In contrast to macroscopic

Thilo Sandner; Jan Uwe Schmidt; Harald Schenk; Hubert Lakner; Minghong Yang; Alexandre Gatto; Norbert Kaiser; Stefan Braun; Thomas Foltyn; Andreas Leson

2005-01-01

399

Highly reflective optical coatings for high-power applications of micro scanning mirrors in the UV-VIS-NIR spectral region  

Microsoft Academic Search

This paper addresses different highly reflective optical coatings on micro scanning mirrors (MSM) for applications in the NIR-VIS-UV- spectral region to enable new applications at high optical power density like laser marking and material treatment. In the common case of MSM with an unprotected Al coating, the absorption limits the maximal power density because of induced heating. In contrast to

Thilo Sandner; Jan U. Schmidt; Harald Schenk; Hubert Lakner; Minghong Yang; Alexandre Gatto; Norbert Kaiser; Stefan Braun; Thomas Foltyn; Andreas Leson

2006-01-01

400

Application of attenuated total reflectance Fourier transform infrared spectroscopy for determination of cefixime in oral pharmaceutical formulations.  

PubMed

A quick and reliable analytical method for the quantitative assessment of cefixime in orally administered pharmaceutical formulations is developed by using diamond cell attenuated total reflectance (ATR) Fourier transform infrared (FT-IR) spectroscopy as an easy procedure for quality control laboratories. The standards for calibration were prepared in aqueous medium ranging from 350 to 6000mg/kg. The calibration model was developed based on partial least square (PLS) using finger print region of FT-IR spectrum in the range from 1485 to 887cm(-1). Excellent coefficient of determination (R(2)) was achieved as high as 0.99976 with root mean square error of 44.8 for calibration. The application of diamond cell (smart accessory) ATR FT-IR proves a reliable determination of cefixime in pharmaceutical formulations to assess the quality of the final product. PMID:23831978

Kandhro, Aftab A; Laghari, Abdul Hafeez; Mahesar, Sarfaraz A; Saleem, Rubina; Nelofar, Aisha; Khan, Salman Tariq; Sherazi, S T H

2013-11-01

401

Confocal supercritical angle microscopy for cell membrane imaging.  

PubMed

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

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

2014-02-01

402

Schlieren confocal microscopy for phase-relief imaging.  

PubMed

We demonstrate a simple phase-sensitive microscopic technique capable of imaging the phase gradient of a transparent specimen, based on the Schlieren modulation and confocal laser scanning microscopy (CLSM). The incident laser is refracted by the phase gradient of the specimen and excites a fluorescence plate behind the specimen to create a secondary illumination; then the fluoresence is modulated by a partial obstructor before entering the confocal pinhole. The quantitative relationship between the image intensity and the sample phase gradient can be derived. This setup is very easy to be adapted to current confocal setups, so that multimodality fluorescence/structure images can be obtained within a single system. PMID:24690716

Xie, Hao; Jin, Dayong; Yu, Junjie; Peng, Tong; Ding, Yichen; Zhou, Changhe; Xi, Peng

2014-03-01

403

Application of Hilbert-Huang transform based instantaneous frequency to seismic reflection data  

NASA Astrophysics Data System (ADS)

Empirical mode decomposition (EMD) is designed to decompose non-stationary, nonlinear data into a series of intrinsic mode functions (IMFs) adaptively. This procedure is automatic, data-driven and time-variant. And then a Hilbert transform is applied to these IMFs. The combination of EMD with a Hilbert transform is known as Hilbert-Huang transform (HHT). HHT can be used to calculate meaningful multi-resolution instantaneous frequency (HHT based instantaneous frequency). Currently, the application of EMD and HHT to seismic data is performed mainly for noise attenuation. In this paper, we demonstrate new insights of EMD and HHT to seismic data analysis. We first extend the research of Flandrin et al. and analyze how EMD behaves on a Gaussian band-pass signal; we then employ HHT based instantaneous frequency on wedge model and real seismic data to delineate thickness variations. Numerical examples of Gaussian band-pass noise indicate that EMD acts as an adaptive, multi-band overlapping filter bank. The analysis of a wedge model and 2D real seismic data illustrates that HHT based instantaneous frequency is more effective than conventional Hilbert transform based instantaneous frequency in delineating the thickness variation of seismic thin bed.

Zhou, Yanhui; Chen, Wenchao; Gao, Jinghuai; He, Yongqiang

2012-07-01

404

Automatic morphing using image registration: Application to continuous tracking of radar reflectivity and rain fields  

NASA Astrophysics Data System (ADS)

Rainfall is one of the most important natural phenomenon that influences human life. Accurate rainfall estimation and prediction are crucial for flood forecasting, flood control, climate diagnostics, and water resource management. Rain data may be collected from numerous sources. Conventional rain gauge networks or meteorological radars provide continuous coverage in time. Satellite observations provide snap-shots of precipitation fields at poor temporal resolution. While a number of spaceborne platforms have been deployed for rain observation, the development of continuous space/time rainfall remains a major challenge. This dissertation seeks alternative techniques to automatically generate continuous data streams of rainfall data from sparse or intermittent observations. In order to avoid human intervention in the process, an automatic procedure is needed for real-time operations. For this purpose, Automatic Morphing Using Image Registration (AMIR) model is developed by integrating automatic image registration and image morphing algorithm. The new AMIR technique uses automatic image registration as the basis for finding control points for the morphing process. In the study of data assimilation for weather forecasting, there is a need to generate continuous streams of rainfall data to alleviate the so-called "spin up" problem, or the inability to provide short-term forecasts [Road90]. The proposed algorithm has been tested using remote sensing images from Next Generation Weather Radars (NEXRAD) and Tropical Rainfall Measuring Mission (TRMM). Three cases of rainfall data have been used. These include the passage of a storm in Florida, hurricane Floyd, and scattered rain in the southwestern of the United States for the same period using NEXRAD radar data as surrogate for spaceborne observations. These cases have drastically different spatial and temporal characteristics and hence provide tests on the applicability of the AMIR method. Comparative experimental results have shown that AMIR advance the current state of the art as it is comparable to manual morphing and outperforms automatic morphing without control points proposed in literature.

Vongsaard, Jearanai

405

Quantifying light scattering with single-mode fiber -optic confocal microscopy  

PubMed Central

Background Confocal microscopy has become an important option for examining tissues in vivo as a diagnostic tool and a quality control tool for tissue-engineered constructs. Collagen is one of the primary determinants of biomechanical stability. Since collagen is also the primary scattering element in skin and other soft tissues, we hypothesized that laser-optical imaging methods, particularly confocal scattered-light scanning, would allow us to quantify scattering intensity and determine collagen content in biological layers. Methods We built a fully automated confocal scattered-light scanner to examine how light scatters in Intralipid, a common tissue phantom, and three-dimensional collagen gels. Intralipid with 0.5%, 1.0%, 1.5%, and 2.0% concentration was filled between precisely spaced glass coverslips. Collagen gels at collagen concentrations from 0.30 mg/mL to 3.30 mg/mL were prepared, and all samples underwent A-mode scanning with multiple averaged scans. In Intralipid samples, light reflected from the upper fluid-glass interface was measured. In collagen gels, average scattering intensity inside the actual gel was measured. In both cases, intensity was correlated with concentration. Results By measuring light attenuation at interface reflections of various thicknesses using our device, we were able to determine that the scattering coefficient at 660 nm of Intralipid at increasing concentrations in water to be 39 cm-1 for each percent increase of Intralipid. We were also able to measure the amount of scattering of various concentrations of collagen in gels directly using backscattered light. The results show a highly linear relationship with an increase of 8.2 arbitrary units in backscattering intensity for every 1 mg increase of collagen within a 1 mL gel volume. Conclusion The confocal scattered-light scanner allows to accurately quantify scattering in Intralipid and collagen gels. Furthermore, a linear relationship between collagen concentration and intensity was found. Confocal scattered-light scanning therefore promises to allow imaging of collagen content in soft tissue layers.

2009-01-01

406

In-situ lateral confocal microscopic surface profilometry with vibration-resistance capability  

NASA Astrophysics Data System (ADS)

In the article, an in-situ 3-D microscopic surface profilometer employing novel lateral confocal scanning principle, also called V-scan lateral confocal microscopy (VLCM), was developed to achieve in-field measurement with an effective vibration-resistance capability. The developed methodology combines digital structured fringe projection, lateral confocal scanning, shape from focus (SFF) and anti-vibration technique to perform lateral scanning for in-situ 3-D surface measurement. For microstructures having low reflectivity and high-slope surfaces to be measured within in-field process environment, it has been recognized as a great challenge for achieving accurate 3-D surface inspection. To overcome this, the presented method employing a new lateral confocal scanning strategy in combining a Z-axis vertical scanning with a horizontal X-axis scanning simultaneously, in which the scan pattern is similar to a V-shape. Meanwhile, to detect potential environmental vibration, a laser fiber interferometric positioning sensor based on heterodyne interferometry is employed to detect potential vibratory displacement between the optical probe and a tested surface for minimizing environment disturbance encountered in a real factory. A depth response curve is constructed by a series of images detected from successive depths during the V-scan lateral scanning. Potential vibration errors can be effectively detected by a fiber optic interometric positioning sensor and compensated simultaneously. A standard step-height target and several industrial V-groove microstructures have been measured to attest the measurement accuracy and feasibility of the developed approach. From the experimental results, it is confirmed that the depth resolution can reach 0.1 ?m and the maximum measurement error can be controlled within 3% of the overall measuring height.

Chen, Liang-Chia; Li, Chih-Kai; Chang, Yi-Wei

2010-08-01

407

Reflective Packaging  

NASA Technical Reports Server (NTRS)

The aluminized polymer film used in spacecraft as a radiation barrier to protect both astronauts and delicate instruments has led to a number of spinoff applications. Among them are aluminized shipping bags, food cart covers and medical bags. Radiant Technologies purchases component materials and assembles a barrier made of layers of aluminized foil. The packaging reflects outside heat away from the product inside the container. The company is developing new aluminized lines, express mailers, large shipping bags, gel packs and insulated panels for the building industry.

1994-01-01

408

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...

409

Confocal Interferometer Without the Para-Axial Approximation.  

National Technical Information Service (NTIS)

The perturbed eigenfunctions of the confocal cavity without the para-axial condition are obtained. It is shown that in spite of the perturbation being small, the eigenfunctions change appreciably. (Atomindex citation 10:459675)

E. Gerck O. Andrade

1978-01-01

410

Solar Confocal Interferometers for Sub-Picometer-Resolution Spectral Filters  

NASA Technical Reports Server (NTRS)

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.

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

2006-01-01

411

Law of refraction for generalised confocal lenslet arrays  

NASA Astrophysics Data System (ADS)

We derive the law of generalised refraction for generalised confocal lenslet arrays, which are arrays of misaligned telescopes. We have implemented this law of refraction in TIM, a custom open-source ray tracer.

Oxburgh, Stephen; White, Chris D.; Antoniou, Georgios; Courtial, Johannes

2014-02-01

412

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...

413

Wideband energy reflectance measurements: effects of negative middle ear pressure and application of a pressure compensation procedure.  

PubMed

The wideband energy reflectance (ER) technique has become popular as a tool for evaluating middle ear function. Negative middle ear pressure (MEP) is a prevalent form of middle ear dysfunction, which may impact application of ER measurements in differential diagnosis. A negative MEP may be countervailed by application of an equivalent negative ear canal pressure. The present study examined ER in the same ears under normal and experimentally induced negative MEP conditions. Thirty-five subjects produced at least one negative MEP each (-40 to -225 daPa). Negative MEP significantly altered ER in a frequency-specific manner that varied with MEP magnitude. ER increased for low- to mid-frequencies with the largest change (~0.20 to 0.40) occurring between 1 and 1.5?kHz. ER decreased for frequencies above 3 kHz with the largest change (~-0.10 to -0.25) observed between 4.5 and 5.5?kHz. Magnitude of changes increased as MEP became more negative, as did the frequencies at which maximum changes occurred, and the frequency at which enhancement transitioned to reduction. Ear canal pressure compensation restored ER to near baseline values. This suggests that the compensation procedure adequately mitigates the effects of negative MEP on ER. Theoretical issues and clinical implications are discussed. PMID:23862811

Shaver, Mark D; Sun, Xiao-Ming

2013-07-01

414

Advantages of chromatic-confocal spectral interferometry in comparison to chromatic confocal microscopy  

NASA Astrophysics Data System (ADS)

Chromatic confocal microscopy (CCM) and spectral interferometry (SI) are established and robust sensor principles. CCM is a focus-based measurement principle, whose lateral and axial resolutions depend on the sensor's numerical aperture (NA), while the measurement range is given by the spectral bandwidth and the chromatic dispersion in the axial direction. Although CCM is a robust principle, its accuracy can be reduced by self-imaging effects or asymmetric illumination of the sensor pupil. Interferometric principles based on the evaluation of the optical path difference, e.g., SI, have proven to be robust against self-imaging. The disadvantage of SI is its measurement range, which is limited by the depth of focus. Hence, the usable NA and the lateral resolution are restricted. Chromatic-confocal spectral interferometry (CCSI) is a combination of SI and CCM, which overcomes these restrictions. The increase of robustness of CCSI compared to CCM due to the interferometric gain has been demonstrated before. In this contribution the advantages of CCSI in comparison to CCM concerning self-imaging artifacts will be demonstrated. Therefore, a new phase-evaluation algorithm with higher resolution concerning classical SI-based evaluation algorithms is presented. For the comparison of different sensor systems, a chirp comparison standard is used.

Lyda, W.; Gronle, M.; Fleischle, D.; Mauch, F.; Osten, W.

2012-05-01

415

[Diagnostic value of confocal microscopy in primary corneal ectasia].  

PubMed

Diagnostic value of confocal microscopy in subclinical corneal ectasia is analysed. Morphological changes were revealed in 71.2% of cases with subclinical keratoconus. Results of the study let us reveal typical morphological abnormalities in subclinical keratoconus, although these changes are not specific for this condition. The method is also not informative for detecting of early signs of pellucid marginal degeneration. Confocal microscopy may be considered an additional specifying method in diagnostic algorithm of subclinical corneal ectasia. PMID:23367757

Egorova, G B; Rogova, A Ia; Mitichkina, T S

2012-01-01

416

In-vivo multi-spectral confocal microscopy  

Microsoft Academic Search

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

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

417

Quantitative Colocalization Analysis of Multicolor Confocal Immunofluorescence Microscopy Images: Pushing Pixels to Explore Biological Phenomena  

PubMed Central

Quantitative colocalization analysis is an advanced digital imaging tool to examine antigens of interest in immunofluorescence images obtained using confocal microscopes. It employs specialized algorithms to estimate the degree of overlap of fluorescence signals and thus enables acquiring important new information not otherwise obtainable using qualitative approaches alone. As raw confocal images have high levels of background, they should be prepared to become suitable for reliable calculation of colocalization coefficients by correcting it. We provide concise theoretical basis of quantitative colocalization analysis, discuss its limitations, and describe proper use of the technique. The use of quantitative colocalization analysis is demonstrated by studying bile salt export pump and multidrug resistance associated protein 2 in the liver and major basic protein and platelet activating factor receptor antigens in conjunctiva. The review is focused on the applicability and correct interpretation of the results of colocalization coefficients calculations.

Zinchuk, Vadim; Zinchuk, Olga; Okada, Teruhiko

2007-01-01

418

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

NASA Astrophysics Data System (ADS)

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.

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

2014-03-01

419

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

NASA Astrophysics Data System (ADS)

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.

Sun, Hui; Kurtz, Ronald; Juhasz, Tibor

2012-08-01

420

Single molecule confocal fluorescence lifetime correlation spectroscopy for accurate nanoparticle size determination.  

PubMed

We report on an experimental procedure in confocal single molecule fluorescence lifetime correlation spectroscopy (FLCS) to determine the range of excitation power and molecular or particulate concentration in solution under which the application of an unmodified model autocorrelation function is justified. This procedure enables fitting of the autocorrelation to an accurate model to measure diffusion length (r) and diffusion time (?D) of single molecules in solution. We also report on the pinhole size dependency of r and ?D in a confocal FLCS platform. This procedure determines a set of experimental parameters with which the Stokes-Einstein (S-E) equation accurately measures the hydrodynamic radii of spherical nanoparticles, enabling the determination of the particle size range for which the hydrodynamic radius by the S-E equation measures the real particle radius. PMID:24879354

Chon, Bonghwan; Briggman, Kimberly; Hwang, Jeeseong

2014-07-14

421

Confocal Brillouin microscopy for three-dimensional mechanical imaging  

PubMed Central

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 spectru