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1

A handheld laser scanning confocal reflectance imagingconfocal Raman  

E-print Network

­ 594 (2007). 5. M. Claybourn and M. Ansell, "Using Raman spectroscopy to solve crime: inks, questionedA handheld laser scanning confocal reflectance imaging­confocal Raman microspectroscopy system reflectance microscopy and confocal Raman spectroscopy have shown potential for non-destructive analysis

Maxwell, Bruce D.

2

Reflectance confocal microscopy of optical phantoms.  

PubMed

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 Biomimic(TM)), and (3) common reflectance standards (Spectralon(TM)). The noninvasive method measured the exponential decay of reflected signal as the focus (z(f)) 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. PMID:22741065

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

2012-06-01

3

A handheld laser scanning confocal reflectance imagingconfocal Raman microspectroscopy system  

PubMed Central

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

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

2012-01-01

4

Confocal Blue Reflectance Imaging in Type 2 Idiopathic Macular Telangiectasia  

Microsoft Academic Search

METHODS. In a prospective observational cross-sectional study, both eyes of 33 patients with type 2 IMT were examined by means of fundus biomicroscopy, fundus photography, fluores- cein angiography, and optical coherence tomography (OCT). Confocal blue reflectance (CBR) imaging was performed using a confocal scanning laser ophthalmoscope (HRA2; Heidelberg Engineering, Heidelberg, Germany). To compare the results derived from different imaging modalities,

Peter Charbel Issa; Tos T. J. M. Berendschot; Giovanni Staurenghi; Frank G. Holz; Hendrik P. N. Scholl

2008-01-01

5

Reflectance confocal microscopy: hallmarks of keratinocyte cancer and its precursors.  

PubMed

Actinic keratosis is a common result of severe sun damage and is usually present on sun-exposed skin. Reflectance confocal microscopy is a non-invasive clinical imaging modality that results in quasi-histological, en face skin images. In this chapter, we review the available literature and distill the common features of actinic keratosis, as seen by reflectance confocal microscopy. Finally, several examples are discussed in the context of matching clinical, histopathological and reflectance confocal microscopy images. Of all of the morphological features of actinic keratoses, the epidermal honeycomb pattern is the most telling when viewing the lesions using reflectance confocal microscopy. In the near future, we expect the definition of consensus criteria for diagnosing actinic keratoses and differentiating this precursor lesion. PMID:25561211

Prow, Tarl W; Tan, Jean-Marie; Pellacani, Giovanni

2015-01-01

6

Straightness measurements by use of a reflection confocal optical system.  

PubMed

Straightness measurement is a very important technique in the field of mechanical engineering. A particular application for straightness measurement is high-accuracy machining on a diamond-turning lathe. We propose a novel, to our knowledge, optical method for measuring the straightness of motion, and its mathematical analysis is outlined. The technique is based on measurement of the lateral displacement of point images by use of reflection confocal optical systems. The advantages of this method are that (i) the lateral displacements in the direction of the two axes perpendicular to the optical axis can be measured, (ii) the rotation angles around all three axes can be measured, and (iii) reflection optical systems are more compact in length than are transmission optical systems. PMID:18324033

Matsuda, K; Roy, M; O'Byrne, J W; Fekete, P W; Eiju, T; Sheppard, C J

1999-09-01

7

FOOD SURFACE TEXTURE MEASUREMENT USING REFLECTIVE CONFOCAL LASER SCANNING MICROSCOPY  

Technology Transfer Automated Retrieval System (TEKTRAN)

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

8

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

PubMed Central

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

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

2015-01-01

9

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 800450 ?m, and objective lens and total probe outer diameters down to 350 ?m and 1.25 mm, respectively, have been achieved. We provide a review of the historical developments of confocal imaging in vivo, the evolution of endomicroscope instrumentation, and the medical applications of confocal endomicroscopy. PMID:21994069

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

2013-01-01

10

Confocal scanning beam laser microscope/macroscope: applications in fluorescence  

NASA Astrophysics Data System (ADS)

A new confocal scanning beam laser microscope/macroscope is described that combines the rapid scan of a scanning beam laser microscope with the large specimen capability of a scanning stage microscope. This instrument combines an infinity-corrected confocal scanning laser microscope with a scanning laser macroscope that uses a telecentric f*(Theta) laser scan lens to produce a confocal imaging system with a resolution of 0.25 microns at a field of view of 25 microns and 5 microns at a field of view of 75,000 microns. The frame rate is 5 seconds per frame for a 512 by 512 pixel image, and 25 seconds for a 2048 by 2048 pixel image. Applications in fluorescence are discussed that focus on two important advantages of the instrument over a confocal scanning laser microscope: an extremely wide range of magnification, and the ability to image very large specimens. Examples are presented of fluorescence and reflected-light images of high quality printing, fluorescence images of latent fingerprints, packaging foam, and confocal autofluorescence images of a cricket.

Dixon, Arthur E.; Damaskinos, Savvas; Ribes, Alfonso

1996-03-01

11

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.

2012-03-01

12

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

PubMed Central

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

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

2014-01-01

13

Clinical Reflectance Confocal Microscope for Imaging of Oral Cancer  

E-print Network

m. (Video 2, QuickTime, 1.0 MB). ....................................................................................... 48 x Figure 10: Zemax design showing the illumination arm of the confocal system including the ETL positioned adjacent...

Jabbour, Joey

2014-08-05

14

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

PubMed

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

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

2014-01-01

15

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

NASA Astrophysics Data System (ADS)

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

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

2014-12-01

16

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

PubMed Central

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

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

2014-01-01

17

Two-photon fluorescence and confocal reflected light imaging of thick tissue structures  

NASA Astrophysics Data System (ADS)

The technology of two-photon excitation has opened a window of opportunity for developing non-invasive medical diagnostic tools capable of monitoring thick tissue biochemical states. Using cellular endogenous chromophores, (beta) -nicotinamide- adenine dinucleotide phosphate [NAD(P)H], the cellular metabolic rates in living human skin were determined. Although important functional information can be obtained from the fluorescence spectroscopy of endogenous chromophores, these chromophores are rather poor contrast enhancing agent for mapping cellular morphology. First, most endogenous chromophores are confined to the cellular cytoplasm which prevents the visualization of other cellular organelles. Second, there is significant variability in the distribution and the quantum yield of endogenous chromophores which depends on tissue biochemistry but prevents consistent comparison of cellular morphology. On the other hand, the deep tissue cellular morphology has been imaged with excellent resolution using reflected light confocal microscopy. In reflected light microscopy, the image contrast originates from the index of refraction differences of the cellular structures. The organelle boundaries with significant index differences such as the plasma membrane and the nucleus envelope can be consistently visualized. A combination of morphological and functional information is required for a thorough tissue study. This presentation describes the development of a new microscope which is capable of simultaneously collecting both two-photon fluorescence and confocal reflected light signals. Promising biomedical applications include the non-invasive diagnosis of skin cancer and the study of wound healing.

Kim, Ki H.; So, Peter T. C.; Kochevar, Irene E.; Masters, Barry R.; Gratton, Enrico

1998-04-01

18

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

PubMed Central

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

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

2014-01-01

19

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

NASA Astrophysics Data System (ADS)

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, Szary 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; Rus-Diaz, Francisca; Gonzlez, Salvador; Stockfleth, Eggert; Ulrich, Martina

2012-01-01

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 1616??mm2 tissue area with 62.5?m lateral and 320ps temporal resolution to guide cellular imaging of suspicious regions. Subsequently, coregistered RCM images are acquired at 7Hz with 400?m diameter FOV, <1???m lateral and 3.5?m axial resolution. FLIM-RCM imaging was performed on a tissue phantom, normal porcine buccal mucosa, and a hamster cheek pouch model of oral carcinogenesis. While FLIM is sensitive to biochemical and macroscopic architectural changes in tissue, RCM provides images of cell nuclear morphology, all key indicators of precancer progression. PMID:23595826

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

2013-01-01

21

Clinical applications of corneal confocal microscopy  

PubMed Central

Corneal confocal microscopy is a novel clinical technique for the study of corneal cellular structure. It provides images which are comparable to in-vitro histochemical techniques delineating corneal epithelium, Bowmans layer, stroma, Descemets membrane and the corneal endothelium. Because, corneal confocal microscopy is a non invasive technique for in vivo imaging of the living cornea it has huge clinical potential to investigate numerous corneal diseases. Thus far it has been used in the detection and management of pathologic and infectious conditions, corneal dystrophies and ecstasies, monitoring contact lens induced corneal changes and for pre and post surgical evaluation (PRK, LASIK and LASEK, flap evaluations and Radial Keratotomy), and penetrating keratoplasty. Most recently it has been used as a surrogate for peripheral nerve damage in a variety of peripheral neuropathies and may have potential in acting as a surrogate marker for endothelial abnormalities. PMID:19668734

Tavakoli, Mitra; Hossain, Parwez; Malik, Rayaz A

2008-01-01

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

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

24

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

NASA Astrophysics Data System (ADS)

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.

2010-05-01

25

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

26

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. PMID:24339910

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

2013-01-01

27

Near-IR fluorescence and reflectance confocal microscopy for imaging of quantum dots in mammalian skin  

PubMed Central

Understanding the skin penetration of nanoparticles (NPs) is an important concern due to the increasing presence of NPs in consumer products, including cosmetics. Technical challenges have slowed progress in evaluating skin barrier and NP factors that contribute to skin penetration risk. To limit sampling error and other problems associated with histological processing, many researchers are implementing whole tissue confocal or multiphoton microscopies. This work introduces a fluorescence and reflectance confocal microscopy system that utilizes near-IR excitation and emission to detect near-IR lead sulfide quantum dots (QDs) through ex vivo human epidermis. We provide a detailed prediction and experimental analysis of QD detection sensitivity and demonstrate detection of QD skin penetration in a barrier disrupted model. The unique properties of near-IR lead-based QDs will enable future studies that examine the impact of further barrier-disrupting agents on skin penetration of QDs and elucidate mechanistic insight into QD tissue interactions at the cellular level. PMID:21698023

Mortensen, Luke J.; Glazowski, Christopher E.; Zavislan, James M.; DeLouise, Lisa A.

2011-01-01

28

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 Abels matrix transfer methods. PMID:24233077

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

2013-01-01

29

Living Matter Observations with a Novel Hyperspectral Supercontinuum Confocal Microscope for VIS to Near-IR Reflectance Spectroscopy  

PubMed Central

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 Abels matrix transfer methods. PMID:24233077

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

2013-01-01

30

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

NASA Astrophysics Data System (ADS)

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

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

2010-08-01

31

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

32

Design and performance evaluation of reflection confocal microscopy using acousto-optical deflector and slit detector  

NASA Astrophysics Data System (ADS)

We describe the design and the implementation of reflection confocal scanning microscopy (CSM) using an acousto-optical deflector (AOD) for the fast horizontal scan and a galvanometer mirror (GM) for the slow vertical scan. In the beam scanning system it is important to maintain the lateral and the axial performance during scanning operation. We propose a simple method to design a scanning system using the finite ray tracing and the diffraction theory. We define a cost function which contains the effect of aberrations on the performance of microscopy. We construct the designed system and evaluate its performance. The OSLO simulation shows that the performances of CSM are not changed with deflection angle. So we conclude that the beam scanning system is properly designed. In addition, we propose an image formation method and show images obtained with the system.

Lee, SeugnWoo; Kang, Dong-Kyun; Yoo, HongKi; Gweon, Dae-Gab; Lee, Suk-Won; Kim, Kwang-Soo

2004-07-01

33

The use of reflectance confocal microscopy for monitoring response to therapy of skin malignancies  

PubMed Central

Summary Reflectance confocal microscopy (RCM) is a new non-invasive imaging technique that enables visualizing cells and structures in living skin in real-time with resolution close to that of histological analysis. RCM has been successfully implemented in the assessment of benign and malignant lesions. Most importantly, it also enables monitoring dynamic changes in the skin over time and in response to different therapies, e.g., imiquimod, photodynamic therapy, and others. Given the often traumatic nature of skin cancer that affects both the physiology and the psychology of the patients, it is crucial to have methods that enable monitoring the response to treatment but that minimize the distress and discomfort associated with such process. This article provides a very brief overview of the fundamentals of RCM and then focuses on its recent employment as a monitoring tool in skin cancer and other pathologies that may require frequent follow-up. PMID:23785598

Ulrich, Martina; Lange-Asschenfeldt, Susanne; Gonzalez, Salvador

2012-01-01

34

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

35

[Application of depth-analysis of confocal Raman micro-spectroscopy to chirography identification].  

PubMed

Depth analysis of confocal Raman micro-spectroscopy was applied to chirography identification. The result indicated that depth analysis has potential application to forensic science field, especially in longitudinal identification of ink and inkpad. No matter what the spatial distributions of the signature pen and inkpad are, confocal Raman micro-spectroscopy can longitudinally distinguish those spatial differences. All those suggested that confocal Raman micro-spectroscopy is a fast, simple, high sensitive and non-destructive technique. PMID:15852817

Lin, Hai-Bo; Xu, Xiao-Xuan; Wang, Bin; Yang, Yan-Yong; Yu, Gang; Zhang, Cun-Zhou; Li, Jie

2005-01-01

36

Reflectance confocal microscopy for the diagnosis of eosinophilic esophagitis: a pilot study conducted on biopsy specimens  

PubMed Central

Background Diagnosis of eosinophilic esophagitis (EoE) currently requires endoscopic biopsy and histopathologic analysis of the biopsy specimens to count intraepithelial eosinophils. Reflectance confocal microscopy (RCM) is an endomicroscopy technology that is capable of obtaining high-resolution, optically sectioned images of esophageal mucosa without the administration of exogenous contrast. Objective In this study, we investigated the capability of a high-speed form of RCM, termed spectrally encoded confocal microscopy (SECM), to count intraepithelial esophageal eosinophils and characterize other microscopic findings of EoE. Design A total of 43 biopsy samples from 35 pediatric patients and 8 biopsy samples from 8 adult patients undergoing EGD for EoE were imaged by SECM immediately after their removal and then processed for routine histopathology. Two SECM readers, trained on adult cases, prospectively counted intraepithelial eosinophils and detected the presence of abscess, degranulation, and basal cell hyperplasia on SECM images from the pediatric patients. A pathologist blinded to the SECM data analyzed the same from corresponding slides. Setting The Gastrointestinal Unit, Massachusetts General Hospital. Results Eosinophils by SECM demonstrated a higher reflectance than the surrounding cells and other inflammatory cells. There was good correlation between SECM and histology maximum eosinophil counts/high-power field (R = 0.76, P < .0001). Intra- and interobserver correlations for SECM counts were very good (R = 0.93 and R = 0.92, respectively; P < .0001). For the commonly used eosinophil count cutoff of 15 per high-power field, the sensitivity and specificity of SECM for EoE were 100%. The sensitivity and specificity for abscess, degranulation, and basal cell hyperplasia were 100% and 82%, 91% and 60%, and 94% and 80%, respectively. Intra- and interobserver agreements for these microscopic features of EoE were very good (? = 0.9/0.9, 0.84/1.0, 0.91/0.81, respectively). Limitation Ex vivo study. Conclusions This study demonstrates that RCM can be used to accurately count intraepithelial eosinophils and identify other microscopic abnormalities associated with EoE on freshly excised biopsy samples. These findings suggest that RCM may be developed into a tool for assessing eosinophilic infiltration in the esophagus in vivo. PMID:21944314

Yoo, Hongki; Kang, DongKyun; Katz, Aubrey J.; Lauwers, Gregory Y.; Nishioka, Norman S.; Yagi, Yukako; Tanpowpong, Pornthep; Namati, Jacqueline; Bouma, Brett E.; Tearney, Guillermo J.

2012-01-01

37

Automated delineation of dermal-epidermal junction in reflectance confocal microscopy image stacks of human skin.  

PubMed

Reflectance confocal microscopy (RCM) images skin noninvasively, with optical sectioning and nuclear-level resolution comparable with that of pathology. On the basis of the assessment of the dermal-epidermal junction (DEJ) and morphologic features in its vicinity, skin cancer can be diagnosed in vivo with high sensitivity and specificity. However, the current visual, qualitative approach for reading images leads to subjective variability in diagnosis. We hypothesize that machine learning-based algorithms may enable a more quantitative, objective approach. Testing and validation were performed with two algorithms that can automatically delineate the DEJ in RCM stacks of normal human skin. The test set was composed of 15 fair- and 15 dark-skin stacks (30 subjects) with expert labelings. In dark skin, in which the contrast is high owing to melanin, the algorithm produced an average error of 7.96.4??m. In fair skin, the algorithm delineated the DEJ as a transition zone, with average error of 8.35.8??m for the epidermis-to-transition zone boundary and 7.65.6??m for the transition zone-to-dermis. Our results suggest that automated algorithms may quantitatively guide the delineation of the DEJ, to assist in objective reading of RCM images. Further development of such algorithms may guide assessment of abnormal morphological features at the DEJ. PMID:25184959

Kurugol, Sila; Kose, Kivanc; Park, Brian; Dy, Jennifer G; Brooks, Dana H; Rajadhyaksha, Milind

2015-03-01

38

In vivo reflectance confocal microscopy evaluation of cheilitis glandularis: a report of 5 cases.  

PubMed

: Cheilitis glandularis (CG) is an uncommon condition of unknown origin; it is clinically characterized by variable degrees of macrocheilia associated with red dilated ostia of minor salivary glands on the vermilion area, which secrete viscous saliva. Histopathological characteristics of CG are comprised of chronic sialadenitis with engorged acinar lobules and dilated ducts; CG also features chronic sun damage (actinic cheilitis and squamous cell carcinoma). These changes may be localized, and a punch biopsy specimen might fail to reveal enough criteria to support the diagnosis of CG. Reflectance confocal microscopy (RCM) is a noninvasive imaging technique that enables an in vivo en face visualization of tissues with a resolution close to conventional histopathology. Its use allows analysis of the entire lip, without excision. We reported the evaluation of 5 cases of CG based on clinical RCM and histopathological correlation. RCM examination of the lip vermilion mainly revealed a bright aspect of the superficial epithelial layers, which corresponded to labial keratosis. Alteration of the classical epithelial honeycomb pattern was observed in RCM, which corresponded to epithelial changes in actinic cheilitis at histopathology. Round, dark empty spaces intermingling the epithelium, corresponded to the ectopic excretory salivary gland ducts that open their ostia within the lip vermilion. In the lamina propria, the most striking feature was superficial salivary gland lobules, seen as dark gray lobular structures. Our study, demonstrated the use of RCM in the evaluation of CG, showing that a correlation between the clinical, digital RCM images and histopathology improved the diagnostic skills in CG evaluation. PMID:25238451

Loureno, Silvia V; Kos, Eliana; Borguezan Nunes, Thais; Bologna, Sheyla B; Sangueza, Martin; Nico, Marcello M S

2015-03-01

39

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

PubMed Central

Reflectance confocal microscopy (RCM) images skin non-invasively, with optical sectioning and nuclear-level resolution comparable to that of pathology. Based on assessment of the dermal-epidermal junction (DEJ) and morphologic features in its vicinity, skin cancer can be diagnosed in vivo with high sensitivity and specificity. However, the current visual, qualitative approach for reading images leads to subjective variability in diagnosis. We hypothesize that machine learning-based algorithms may enable a more quantitative, objective approach. Testing and validation was performed with two algorithms that can automatically delineate the DEJ in RCM stacks of normal human skin. The test set was composed of 15 fair and 15 dark skin stacks (30 subjects) with expert labellings. In dark skin, in which the contrast is high due to melanin, the algorithm produced an average error of 7.96.4?m. In fair skin, the algorithm delineated the DEJ as a transition zone, with average error of 8.35.8?m for the epidermis-to-transition zone boundary and 7.65.6?m for the transition zone-to-dermis. Our results suggest that automated algorithms may quantitatively guide the delineation of the DEJ, to assist in objective reading of RCM images. Further development of such algorithms may guide assessment of abnormal morphological features at the DEJ. PMID:25184959

Park, Brian

2014-01-01

40

Image segmentation for integrated multiphoton microscopy and reflectance confocal microscopy imaging of human skin in vivo  

PubMed Central

Background Non-invasive cellular imaging of the skin in vivo can be achieved in reflectance confocal microscopy (RCM) and multiphoton microscopy (MPM) modalities to yield complementary images of the skin based on different optical properties. One of the challenges of in vivo microscopy is the delineation (i.e., segmentation) of cellular and subcellular architectural features. Methods In this work we present a method for combining watershed and level-set models for segmentation of multimodality images obtained by an integrated MPM and RCM imaging system from human skin in vivo. Results Firstly, a segmentation model based on watershed is introduced for obtaining the accurate structure of cell borders from the RCM image. Secondly,, a global region based energy level-set model is constructed for extracting the nucleus of each cell from the MPM image. Thirdly, a local region-based Lagrange Continuous level-set approach is used for segmenting cytoplasm from the MPM image. Conclusions Experimental results demonstrated that cell borders from RCM image and boundaries of cytoplasm and nucleus from MPM image can be obtained by our segmentation method with better accuracy and effectiveness. We are planning to use this method to perform quantitative analysis of MPM and RCM images of in vivo human skin to study the variations of cellular parameters such as cell size, nucleus size and other mophormetric features with skin pathologies. PMID:25694949

Chen, Guannan; Lui, Harvey

2015-01-01

41

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

42

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

PubMed

Mohs surgery for the removal of nonmelanoma skin cancers (NMSCs) is performed in stages, while being guided by the examination for residual tumor with frozen pathology. However, preparation of frozen pathology at each stage is time consuming and labor intensive. Real-time intraoperative reflectance confocal microscopy(RCM), combined with video mosaicking, may enable rapid detection of residual tumor directly in the surgical wounds on patients. We report our initial experience on 25 patients, using aluminum chloride for nuclear contrast. Imaging was performed in quadrants in the wound to simulate the Mohs surgeons examination of pathology. Images and videos of the epidermal and dermal margins were found to be of clinically acceptable quality. Bright nuclear morphology was identified at the epidermal margin and detectable in residual NMSC tumors. The presence of residual tumor and normal skin features could be detected in the peripheral and deep dermal margins. Intraoperative RCM imaging may enable detection of residual tumor directly on patients during Mohs surgery, and may serve as an adjunct for frozen pathology. Ultimately, for routine clinical utility, a stronger tumor-to-dermis contrast may be necessary, and also a smaller microscope with an automated approach for imaging in the entire wound in a rapid and controlled manner. PMID:25706821

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

2015-06-01

43

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

44

Development of a Confocal Optical System Design for Molecular Imaging Applications of Biochip  

PubMed Central

A novel confocal optical system design and a dual laser confocal scanner have been developed to meet the requirements of highly sensitive detection of biomolecules on microarray chips, which is characterized by a long working distance (wd>3.0?mm), high numerical aperture (NA=0.72), and only 3 materials and 7 lenses used. This confocal optical system has a high scanning resolution, an excellent contrast and signal-to-noise ratio, and an efficiency of collected fluorescence of more than 2-fold better than that of other commercial confocal biochip scanners. The scanner is as equally good for the molecular imaging detection of enclosed biochips as for the detection of biological samples on a slide surface covered with a cover-slip glass. Some applications of gene and protein imagings using the dual laser confocal scanner are described. PMID:18256735

Huang, Guoliang; Xu, Shukuan; Zhu, Jiang; Deng, Cheng; Dong, Zhonghua; Yang, Yang; Yang, Xiaoyong; Wang, Xianhua; Jin, Guofan

2007-01-01

45

Evaluation of Morphology and Microcirculation of the Pancreas by ex vivo and in vivo Reflectance Confocal Microscopy  

Microsoft Academic Search

Background: Near-infrared reflectance confocal microscopy (CM) provides non-invasive real-time images of thin virtual horizontal tissue sections with high resolution and contrast. Aim: Aim of the study was to characterize morphology, microcirculation and leukocyte-endothelial interaction (LEI) in normal pancreas by in vivo and ex vivo CM. Methods: For CM we used water immersion objective lenses of high numerical aperture and near-infrared

Tobias Keck; Vanessa Campo-Ruiz; Andrew L. Warshaw; R. Rox Anderson; Carlos Fernndez-del Castillo; Salvador Gonzlez

2001-01-01

46

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

47

Morphological characterization of solar lentigines by in vivo reflectance confocal microscopy: a longitudinal approach.  

PubMed

Solar lentigines are benign hyperpigmented skin lesions. Despite their widespread distribution, knowledge on the mechanisms of development is largely unknown. A clinical study was designed in which solar lentigines were characterized using various non-invasive clinical techniques. A subset of solar lentigines was followed over a 5-year time period. One hundred and twenty-eight solar lentigines were evaluated using in vivo reflectance confocal microscopy (RCM) for the evaluation of the length and density of their dermal papillae as well as the deformation of the alignment pattern of hyperrefractive basal cells. Skin colour, colour contrast, the size of the solar lentigo, epidermal proliferation rate, melanin and haemoglobin content were quantified. RCM imaging of solar lentigines revealed a profound structural deformation of the dermal papillae, as the alignment pattern of hyperrefractive basal cells shifted from a circle in non-lesional skin to an irregular non-circular shape in solar lentigines. There was a rise in the number of dermal papillae, and these dermal papillae were significantly longer. Solar lentigines had increased melanin and haemoglobin levels and a higher rate of epidermal proliferation. For a subset of nineteen solar lentigines, a longitudinal study was set-up in which these measurements were repeated 5 years after the first evaluation. The deformation and the number of the hyperrefractive dermal papillary rings increased significantly over the 5-year time span. The size of the lesion increased, and the skin colour became darker. RCM is a useful non-invasive clinical tool for the characterization of solar lentigines, in particular the compressive deformation of the dermal papillae. This deformation became more severe over a time period of 5 years. To our knowledge, this is the first time that the in vivo time-dependent progression of solar lentigines was supported by RCM images, contributing to an improved understanding of the formation and progression of solar lentigines. PMID:23075151

Pollefliet, C; Corstjens, H; Gonzlez, S; Hellemans, L; Declercq, L; Yarosh, D

2013-04-01

48

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

2008-02-01

49

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

NASA Astrophysics Data System (ADS)

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

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

2012-02-01

50

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

PubMed

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

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

1995-01-01

51

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

NASA Astrophysics Data System (ADS)

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

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

2012-06-01

52

[Application of confocal simultaneous scanner unit in the study of forebrain neurodevelopment in zebrafish].  

PubMed

With the application of the photoconversion technology of genetically expressed fluorescent proteins in biologic field, more powerful confocal imaging ability was demanded. The aim of the present study was to establish an experimental model employing confocal simultaneous scanner unit for simultaneous laser stimulation and imaging, taking study of forebrain neurodevelopment in zebrafish as an example. In the present study, 36-48-hour-old Tg(lhx5:kaede) zebrafish embryos were mounted with 1.2% low melting temperature agarose. The forebrain neurons marked with kaede were observed using the simultaneous scanner unit of confocal microscopy. The 405 nm laser was used to stimulate the region of interest (ROI), while 488 and 559 nm lasers were used to acquire images at the same time. The photoconversion state of kaede protein was then reviewed, and the projecting pattern of neurons stimulated by the ultraviolet laser was examined. The results showed that, the fluorescence of stimulated kaede turned from green to red, and the photoconversion of kaede demonstrated anterior dorsal telencephalon (ADt) neurons projected axons ventrally into the anterior commissure (AC) and supraoptic tract (SOT). These results suggest the confocal simultaneous scanner unit meets the demand of the photoconversion experiment. The application of confocal simultaneous scanning technology in examining Tg(lhx5:kaede) zebrafish embryos affords an ideal experimental model in neurodevelopment study. PMID:23426517

Shi, Ying; Gao, Jing-Xia; Peng, Gang; Jiang, Min

2013-02-25

53

Label-free in vivo imaging of myelinated axons in health and disease with spectral confocal reflectance microscopy  

PubMed Central

We report a new technique for high-resolution in vivo imaging of myelinated axons in the brain, spinal cord and peripheral nerve that requires no fluorescent labeling. This method, based on spectral confocal reflectance microscopy (SCoRe), uses a conventional laser scanning confocal system to generate images by merging the simultaneously reflected signals from multiple lasers of different wavelengths. Striking color patterns unique to individual myelinated fibers are generated that facilitate their tracing in dense axonal areas. These patterns highlight nodes of Ranvier and Schmidt-Lanterman incisures and can be used to detect various myelin pathologies. Using SCoRe we performed chronic brain imaging up to 400 ?m deep, capturing for the first time de novo myelination of mouse cortical axons in vivo. We also established the feasibility of imaging myelinated axons in the human cerebral cortex. SCoRe adds a powerful component to the evolving toolbox for imaging myelination in living animals and potentially in humans. PMID:24681598

Schain, Aaron J.; Hill, Robert A.; Grutzendler, Jaime

2013-01-01

54

Analysis of the efficiency of hair removal by different optical methods: comparison of Trichoscan, reflectance confocal microscopy, and optical coherence tomography.  

PubMed

Noninvasive diagnostic tools, such as Trichoscan, reflectance confocal microscopy (RCM), and optical coherence tomography (OCT), are efficient methods of hair shaft and growth evaluation. The aim of this study was to carry out a comparative assessment of these three medical procedures by measuring the hair shaft and hair growth after hair removal for a defined period of five days. The application of these techniques was demonstrated by measuring hair growth on the lower leg of six female volunteers. After removal of the hair shaft with a shaving system, the hair follicle infundibula and the length of the growing hairs were measured with the Trichoscan, RCM, and OCT method. All three methods are reliable hair measuring tools after hair removal. Trichoscan is best suited in the implementation of hair growth measurement and RCM in the analysis of hair follicles, whereas the OCT system can be consulted as an additional measurement for the evaluation of the hair follicle and length. PMID:23223980

Kuck, Monika; Schanzer, Sabine; Ulrich, Martina; Garcia Bartels, Natalie; Meinke, Martina C; Fluhr, Joachim; Krah, Martin; Blume-Peytavi, Ulrike; Stockfleth, Eggert; Lademann, Jrgen

2012-10-01

55

Analysis of the efficiency of hair removal by different optical methods: comparison of Trichoscan, reflectance confocal microscopy, and optical coherence tomography  

NASA Astrophysics Data System (ADS)

Noninvasive diagnostic tools, such as Trichoscan, reflectance confocal microscopy (RCM), and optical coherence tomography (OCT), are efficient methods of hair shaft and growth evaluation. The aim of this study was to carry out a comparative assessment of these three medical procedures by measuring the hair shaft and hair growth after hair removal for a defined period of five days. The application of these techniques was demonstrated by measuring hair growth on the lower leg of six female volunteers. After removal of the hair shaft with a shaving system, the hair follicle infundibula and the length of the growing hairs were measured with the Trichoscan, RCM, and OCT method. All three methods are reliable hair measuring tools after hair removal. Trichoscan is best suited in the implementation of hair growth measurement and RCM in the analysis of hair follicles, whereas the OCT system can be consulted as an additional measurement for the evaluation of the hair follicle and length.

Kuck, Monika; Schanzer, Sabine; Ulrich, Martina; Bartels, Natalie Garcia; Meinke, Martina C.; Fluhr, Joachim; Krah, Martin; Blume-Peytavi, Ulrike; Stockfleth, Eggert; Lademann, Jrgen

2012-10-01

56

Simultaneous Mechanical Loading and Confocal Reflection Microscopy for Three-Dimensional Microbiomechanical Analysis of Biomaterials and Tissue Constructs  

NASA Astrophysics Data System (ADS)

At present, mechanisms by which specific structural and mechanical properties of the three-dimensional extracellular matrix microenvironment influence cell behavior are not known. Lack of such knowledge precludes formulation of engineered scaffolds or tissue constructs that would deliver specific growth-inductive signals required for improved tissue restoration. This article describes a new mechanical loading imaging technique that allows investigations of structural mechanical properties of biomaterials as well as the structural mechanical basis of cell scaffold interactions at a microscopic level and in three dimensions. The technique is based upon the integration of a modified, miniature mechanical loading instrument with a confocal microscope. Confocal microscopy is conducted in a reflection and/or fluorescence mode for selective visualization of load-induced changes to the scaffold and any resident cells, while maintaining each specimen in a live, fully hydrated state. This innovative technique offers several advantages over current biomechanics methodologies, including simultaneous visualization of scaffold and/or cell microstructure in three dimensions during mechanical loading; quantification of macroscopic mechanical parameters including true stress and strain; and the ability to perform multiple analyses on the same specimen. This technique was used to determine the structural mechanical properties of three very different biological materials: a reconstituted collagen matrix, a tissue-derived biomaterial, and a tissue construct representing cells and matrix.

Voytik-Harbin, Sherry L.; Roeder, Blayne A.; Sturgis, Jennifer E.; Kokini, Klod; Robinson, J. Paul

2003-02-01

57

Video-Mosaicing of Reflectance Confocal Images For Rapid Examination of Large Areas of Skin In Vivo  

PubMed Central

Background With reflectance confocal microscopy (RCM) imaging, skin cancers can be diagnosed in vivo and margins detected to guide treatment. Since the field of view of an RCM image is much smaller than the typical size of lesions, mosaicing approaches have been developed to display larger areas of skin. However, the current paradigm for RCM mosaicing in vivo is limited both in speed and to pre-selected rectangular-shaped small areas. Another approach, called video-mosaicing, enables higher speeds and real-time operator-selected areas of any size and shape, and will be more useful for RCM examination of skin in vivo. Objectives To demonstrate the feasibility and clinical potential of video-mosaicing of RCM images to rapidly display large areas of skin in vivo. Methods Thirteen videos of benign lesions, melanocytic cancers and residual basal cell carcinoma margins were collected on volunteer subjects with a handheld RCM scanner. The images from each video were processed and stitched into mosaics to display the entire area that was imaged. Results Acquisition of RCM videos covering 5.016.0 mm2 was performed in 2060 seconds. The video-mosaics were visually determined to be of high quality for resolution, contrast and seamless contiguity, and the appearance of cellular-level and morphologic detail. Conclusion Video-mosaicing confocal microscopy, with real-time operator-choice of the shape and size of the area to be imaged, will enable rapid examination of large areas of skin in vivo. This approach may further advance noninvasive detection of skin cancer and, eventually, facilitate wider adoption of RCM imaging in the clinic. PMID:24720744

Kose, Kivanc; Cordova, Miguel; Duffy, Megan; Flores, Eileen S.; Brooks, Dana H.; Rajadhyaksha, Milind

2015-01-01

58

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

59

Rheology and Confocal Reflectance Microscopy as Probes of Mechanical Properties and Structure during Collagen and Collagen\\/Hyaluronan Self-Assembly  

Microsoft Academic Search

In this work, the gelation of three-dimensional collagen and collagen\\/hyaluronan (HA) composites is studied by time sweep rheology and time lapse confocal reflectance microscopy (CRM). To investigate the complementary nature of these techniques, first collagen gel formation is investigated at concentrations of 0.5, 1.0, and 1.5 mg\\/mL at 37C and 32C. The following parameters are used to describe the self-assembly

Ya-Li Yang; Laura J. Kaufman

2009-01-01

60

Assessment of a superficial chemical peel combined with a multimodal, hydroquinone-free skin brightener using in vivo reflectance confocal microscopy.  

PubMed

The combination of in-office procedures such as chemical peels with topical maintenance therapies has been shown to provide greater efficacy than either treatment by itself in the management of melasma. A series of 3 case studies were conducted to evaluate the efficacy and tolerability of one superficial chemical peel (containing a proprietary blend of resorcinol, lactic acid, salicylic acid, and retinol) combined with a topical multimodal, hydroquinone-free skin brightener as postpeel maintenance therapy. Patients presented with moderate to severe facial hyperpigmentation. At baseline, subjects received the superficial chemical peel treatment followed by a standard postpeel skin care regimen (cleanser, moisturizer, and SPF 30+ sunscreen). Approximately 1 week after the peel procedure, subjects initiated twice-daily application of the skin brightener. Subjects were then evaluated for Global Improvement in Hyperpigmentation by the investigator for up to 7 weeks postpeel. Standardized digital photographs of the subjects facial skin and in vivo reflectance confocal microscopy (RCM) images were taken of a target hyperpigmented lesion at baseline and at follow-up. Standardized photography and in vivo RCM images at baseline and at postpeel show the improvements observed by the investigator. Results from these case studies suggest that the combination of a superficial chemical peel with topical maintenance and the multimodal skin brightener may provide an effective treatment approach for subjects with moderate to severe facial hyperpigmentation. PMID:23545932

Goberdhan, Lisa T; Mehta, Rahul C; Aguilar, Caroline; Makino, Elizabeth T; Colvan, Lora

2013-03-01

61

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.

2011-03-01

62

Wavelength swept spectrally encoded confocal microscopy for biological and clinical applications  

E-print Network

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

Boudoux, Caroline

2007-01-01

63

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. PMID:24872922

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

2014-01-01

64

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

PubMed Central

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

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

2001-01-01

65

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

66

Applicability of confocal laser scanning microscopy for evaluation and monitoring of cutaneous wound healing  

NASA Astrophysics Data System (ADS)

There is a high demand for noninvasive imaging techniques for wound assessment. In vivo reflectance confocal laser scanning microscopy (CLSM) represents an innovative optical technique for noninvasive evaluation of normal and diseased skin in vivo at near cellular resolution. This study was designed to test the feasibility of CLSM for noninvasive analysis of cutaneous wound healing in 15 patients (7 male/8 female), including acute and chronic, superficial and deep dermal skin wounds. A commercially available CLSM system was used for the assessment of wound bed and wound margins in order to obtain descriptive cellular and morphological parameters of cutaneous wound repair noninvasively and over time. CLSM was able to visualize features of cutaneous wound repair in epidermal and superficial dermal wounds, including aspects of inflammation, neovascularisation, and tissue remodelling in vivo. Limitations include the lack of mechanic fixation of the optical system on moist surfaces restricting the analysis of chronic skin wounds to the wound margins, as well as a limited optical resolution in areas of significant slough formation. By describing CLSM features of cutaneous inflammation, vascularisation, and epithelialisation, the findings of this study support the role of CLSM in modern wound research and management.

Lange-Asschenfeldt, Susanne; Bob, Adrienne; Terhorst, Dorothea; Ulrich, Martina; Fluhr, Joachim; Mendez, Gil; Roewert-Huber, Hans-Joachim; Stockfleth, Eggert; Lange-Asschenfeldt, Bernhard

2012-07-01

67

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

SciTech Connect

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

Fredrich, J.T.

1999-02-10

68

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

NASA Astrophysics Data System (ADS)

A new type of confocal Raman microscope called a Fourier transform confocal Raman microscope (FT-CRM) was designed, built and characterized with respect to its spatio-spectral imaging properties. Several different applications of the FT-CRM are presented that take advantage of its unique spectral and spatial imaging characteristics. The instrument combines focused illumination with spatially-filtered detection in a confocal optical configuration to collect photons scattered from a diffraction-limited volume in the sample (typically [<]510-18/ m3) and reject photons from outside that region. The molecular vibrational information encoded in the inelastic, or Raman, spectral component of light scattered from the confocal volume is measured with a visible light Fourier transform Raman spectrometer. By scanning the sample relative to the confocal volume, a volumetric Raman spectrochemical image of the sample can be constructed. Raman scattering is an inherently inefficient process; hence an optimal radius pinhole must be found that balances the FT-CRM optical throughput against the microscope spatial resolution and image contrast. Detailed experimental measurements mapped out the FT-CRM spatial response (axial and lateral), optical throughput and image signal-to-background and signal-to-noise ratios as a function of pinhole radius. Excellent agreement was found between these measurements and the predictions of a theoretical microscope model also developed as part of this thesis. Several applications of the FT-CRM included volumetric compositional imaging of three-dimensional chemically inhomogeneous materials such as cellulose and polyester fibers in water or two immiscible optically- similar liquids, water and trichloroehthylene, in a porous quartz sandstone matrix. The potential of the FT- CRM for non-invasive spectrochemical detection and imaging through a turbid tissue-like medium was demonstrated and a new spectral estimator, Fast Orthogonal Search, was evaluated to replace the discrete Fourier transform to improve the microscope performance.

Brenan, Colin John Herbert

69

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...

70

Scanning computed confocal imager  

DOEpatents

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

George, John S. (Los Alamos, NM)

2000-03-14

71

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

NASA Astrophysics Data System (ADS)

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

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

2012-10-01

72

Application of regularized RichardsonLucy algorithm for deconvolution of confocal microscopy images  

PubMed Central

Although confocal microscopes have considerably smaller contribution of out-of-focus light than widefield microscopes, the confocal images can still be enhanced mathematically if the optical and data acquisition effects are accounted for. For that, several deconvolution algorithms have been proposed. As a practical solution, maximum-likelihood algorithms with regularization have been used. However, the choice of regularization parameters is often unknown although it has considerable effect on the result of deconvolution process. The aims of this work were: to find good estimates of deconvolution parameters; and to develop an open source software package that would allow testing different deconvolution algorithms and that would be easy to use in practice. Here, RichardsonLucy algorithm has been implemented together with the total variation regularization in an open source software package IOCBio Microscope. The influence of total variation regularization on deconvolution process is determined by one parameter. We derived a formula to estimate this regularization parameter automatically from the images as the algorithm progresses. To assess the effectiveness of this algorithm, synthetic images were composed on the basis of confocal images of rat cardiomyocytes. From the analysis of deconvolved results, we have determined under which conditions our estimation of total variation regularization parameter gives good results. The estimated total variation regularization parameter can be monitored during deconvolution process and used as a stopping criterion. An inverse relation between the optimal regularization parameter and the peak signal-to-noise ratio of an image is shown. Finally, we demonstrate the use of the developed software by deconvolving images of rat cardiomyocytes with stained mitochondria and sarcolemma obtained by confocal and widefield microscopes. PMID:21323670

Laasmaa, M; Vendelin, M; Peterson, P

2011-01-01

73

Broadband reflectance coatings for vacuum ultraviolet application  

NASA Technical Reports Server (NTRS)

An experimental investigation has obtained results indicating that neither LaF3 nor LiYF4 are acceptable alternatives to MgF2 as coatings for vacuum-deposited aluminum mirrors from which high UV reflectance down to 1150 A is required. Nevertheless, LaF3 may prove useful in those specialized applications in which the suppression of lower wavelength emissions, such as the 1216-A hydrogen line, is desirable.

Herzig, Howard; Fleetwood, C. M., Jr.; Flint, B. K.

1987-01-01

74

Principles: Confocal Laser Scanning Microscopy  

NSDL National Science Digital Library

Following a description of the fundamental differences between a conventional and a confocal microscope, this monograph will set out the special features of the confocal Laser Scanning Microscope (LSM) and the capabilities resulting from them. The conditions in fluorescence applications will be given priority treatment throughout.

Stefan Wilhelm (Zeiss)

2011-01-01

75

In Vivo Noninvasive Imaging of Healthy Lower Lip Mucosa: A Correlation Study between High-Definition Optical Coherence Tomography, Reflectance Confocal Microscopy, and Histology  

PubMed Central

In recent years, technology has allowed the development of new diagnostic techniques which allow real-time, in vivo, noninvasive evaluation of morphological changes in tissue. This study compares and correlates the images and findings obtained by high-definition optical coherence tomography (HD-OCT) and reflectance confocal microscopy (RCM) with histology in normal healthy oral mucosa. The healthy lip mucosa of ten adult volunteers was imaged with HD-OCT and RCM. Each volunteer was systematically evaluated by RCM starting in the uppermost part of the epithelium down to the lamina propia. Afterwards, volunteers were examined with a commercially available full-field HD-OCT system using both the slice and the en-face mode. A punch biopsy of the lower lip mucosa was obtained and prepared for conventional histology. The architectural overview offered by slice mode HD-OCT correlates with histologic findings at low magnification. In the superficial uppermost layers of the epithelium, RCM imaging provided greater cellular detail than histology. As we deepened into the suprabasal layers, the findings are in accordance with physiological cellular differentiation and correlate with the images obtained from conventional histology. The combined use of these two novel non-invasive imaging techniques provides morphological imaging with sufficient resolution and penetration depth, resulting in quasihistological images. PMID:24078807

Garca-Hernndez, Alejandra; Roldn-Marn, Rodrigo; Iglesias-Garcia, Pablo; Malvehy, Josep

2013-01-01

76

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

PubMed Central

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

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

2013-01-01

77

Rheology and Confocal Reflectance Microscopy as Probes of Mechanical Properties and Structure during Collagen and Collagen/Hyaluronan Self-Assembly  

PubMed Central

In this work, the gelation of three-dimensional collagen and collagen/hyaluronan (HA) composites is studied by time sweep rheology and time lapse confocal reflectance microscopy (CRM). To investigate the complementary nature of these techniques, first collagen gel formation is investigated at concentrations of 0.5, 1.0, and 1.5 mg/mL at 37C and 32C. The following parameters are used to describe the self-assembly process in all gels: the crossover time (tc), the slope of the growth phase (kg), and the arrest time (ta). The first two measures are determined by rheology, and the third by CRM. A frequency-independent rheological measure of gelation, tg, is also measured at 37C. However, this quantity cannot be straightforwardly determined for gels formed at 32C, indicating that percolation theory does not fully capture the dynamics of collagen network formation. The effects of collagen concentration and gelation temperature on kg, tc, and ta as well as on the mechanical properties and structure of these gels both during gelation and at equilibrium are elucidated. Composite collagen/HA gels are also prepared, and their properties are monitored at equilibrium and during gelation at 37C and 32C. We show that addition of HA subtly alters mechanical properties and structure of these systems both during the gelation process and at equilibrium. This occurs in a temperature-dependent manner, with the ratio of HA deposited on collagen fibers versus that distributed homogeneously between fibers increasing with decreasing gelation temperature. In addition to providing information on collagen and collagen/HA structure and mechanical properties during gelation, this work shows new ways in which rheology and microscopy can be used complementarily to reveal details of gelation processes. PMID:19217873

Yang, Ya-li; Kaufman, Laura J.

2009-01-01

78

New modal wave-front sensor: application to adaptive confocal fluorescence microscopy and two-photon excitation fluorescence microscopy  

NASA Astrophysics Data System (ADS)

Confocal and multiphoton microscopes are particularly sensitive to specimen- or system-induced aberrations, which result in decreased resolution and signal-to-noise ratio. The inclusion of an adaptive optics correction system could help overcome this limitation and restore diffraction-limited performance, but such a system requires a suitable method of wave-front measurement. By extending the concept of a modal wave-front sensor previously described by Neil J. Opt. Soc. Am. A 17 , 10981107 (2000), we present a new sensor capable of measuring directly the Zernike aberration modes introduced by a specimen. This modal sensor is particularly suited to applications in three-dimensional microscopy because of its inherent axial selectivity; only those wave fronts originating in the focal region contribute to the measured signal. Four wave-front sensor configurations are presented and their input response is characterized. Sensitivity matrices and axial responses are presented. 2002 Optical Society of America

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

2002-10-01

79

Laser confocal feedback profilometry  

NASA Astrophysics Data System (ADS)

In this paper, a novel profiling method, Laser Confocal Feedback Profilometery (LCFP), combining quasi-common-path heterodyne phase detection with laser confocal feedback technology, is proposed. A microchip Nd:YAG laser emits 1064nm laser, which passes through a pinhole and frequency shifter, and is focused onto the sample surface. The reflected light is coupled back to the microchip laser cavity and forms the frequency shifted feedback light, causing the laser intensity modulation. When the sample is scanned laterally, its surface height variation changes both the phase and strength of the feedback light. LCFP then extracts both the amplitude and phase information out of the laser intensity modulation to determine the integral and fractional number of half laser wavelengths contained in the height variation of two points on the sample surface. LCFP can thus overcome the half-laser-wavelength limit of phase measurement in the axial direction. The high sensitivity of microchip laser to feedback light makes LCFP able to measure samples with very low reflectivity. The LCFP experimental setup is built, and it has successfully measured the height of the stages on a glass-substrate grating. The current performances of LCFP are as followed: the axial resolution is better than 2nm, the axial range about 5?m, and the detectable reflectivity as low as 10-9. Due to its direct traceability to laser wavelength, LCFP can potentially be used as the metrology standard of small-scale features.

Wan, Xinjun; Zhang, Shulian; Ren, Zhou

2008-08-01

80

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

2005-11-01

81

Diffuse reflectance imaging with astronomical applications  

E-print Network

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

Hasinoff, Samuel W.

82

Confocal Microscopy Of The Eye.  

NASA Astrophysics Data System (ADS)

A laser scanning confocal microscope was used to study the structure of human donor eyes and enucleated rabbit eyes. Reflected light confocal images were obtained with a Leitz water immersion objective (50X, NA 1.0). A drop of bicarbonate Ringer's was placed between the objective and the tissue to optically couple the tissue. The confocal microscope was used to image the following objects within the eye: superficial epithelial cells, super basal and basal epithelial cells, basement membrane, stromal nerve plexus, nerve fibers, nuclei and cell bodies of stromal keratocytes, cell processes of stromal keratocytes, Descemet's membrane, and the endothelial cells. In addition, the ocular lens and excised retina were imaged. The confocal microscope produces images of the eye with the following enhanced features: increased lateral resolution, decreased depth of field, and increased contrast of transparent ocular structures. It is concluded that confocal imaging systems are an improvement over traditional optical instruments, and they may develop into a new tool for basic visual science and clinical ophthalmology.

Masters, Barry R.

1989-12-01

83

Near-surface seismic reflection applications  

E-print Network

of the consolidated sedimentary bedrock is about 2.4 g/cc whereas the density of the unconsolidated alluvium is probably less than 2.0 g/cc, which increases the acoustic impedance contrast even more. Why, then, do we not see a bedrock reflection, even...

Steeples, Don W.

2004-01-01

84

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...

85

Clinical applications of a real-time scanning-slit confocal microscope designed for real-time observations of the in-vivo human cornea  

NASA Astrophysics Data System (ADS)

We describe a new, real-time, flying slit confocal microscope, that has unique features and imaging characteristics for in vivo human ocular imaging. In vivo real-time confocal microscopy is currently used to investigate the tear film, renewal of the ocular surface, the role of epithelial innervation in epithelial cell proliferation, wound healing, kinetics of drug penetration, the effects of laser refractive surgery on the keratocyte activation and distribution in the stroma, and the nature of endothelial defects. The following clinical examples will be presented and discussed: confocal microscopy of normal human basal and wing cells in the epithelium, confocal microscopy of lamellar and penetrating corneal grafts, confocal microscopy of corneal ulcer, confocal microscopy of scar formation after herpes keratitis, and confocal microscopy of corneal innervation. The use of scanning slit confocal microscopes has unique advantages over other instrumental systems based on pinhole-containing Nipkow disks (tandem-scanning confocal microscopes) for clinical in vivo confocal microscopy.

Masters, Barry R.

1995-05-01

86

Liquid level sensing based on laser differential confocal detectors  

NASA Astrophysics Data System (ADS)

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

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

2015-01-01

87

Transparent superhydrophobic surfaces for applications of controlled reflectance.  

PubMed

This work involves a new optical application for transparent superhydrophobic materials, which enables low-energy optical contact between a liquid and solid surface. The new technique described here uses this surface property to control the reflectance of a surface using frustration of total internal reflection. Surface chemistry and appropriate micro-scale and nano-scale geometries are combined to produce interfaces with low adhesion to water and the degree to which incident light is reflected at this interface is controlled by the movement of water, thereby modifying the optical characteristics at the interface. The low adhesion of water to superhydrophobic surfaces is particularly advantageous in imaging applications where power use must be minimized. This paper describes the general approach, as well as a proof-of-principle experiment in which the reflectance was controlled by moving a water drop into and out of contact with a superhydrophobic surface by variation of applied electrostatic pressure. PMID:22505153

Gou, Steven; Mossman, Michele; Whitehead, Lorne

2012-04-10

88

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] Bnard & 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, Bnard; Luc-Serge, Doucet; Sabine, Palle; Dmitri A., Ionov

2010-05-01

89

Contrast reversal confocal microscopy  

NASA Astrophysics Data System (ADS)

We propose a novel method to improve the lateral resolution of a general confocal laser scanning microscopy (CLSM) by 10-35%, which can be readily realized by manipulating the shape of the excitation focal spot to a doughnut one. As the contrast of image is reversed synchronously, the raw data is further handled by the deconvolution algorithm to convert the doughnut point spread function (PSF) to a peak-centered distribution, so that a more intuitive vision will be given. Depending on the strategies like saturation excitation or doughnut size shrinkage, the resolution can be further optimized. This setup is valid for diverse systems and may find use in a variety of applications.

Hao, Xiang; Kuang, Cuifang; Gu, Zhaotai; Li, Shuai; Li, Yanghui; Liu, Xu

2013-07-01

90

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

91

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

PubMed Central

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

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

2015-01-01

92

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

PubMed

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

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

2015-01-01

93

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

94

Diffuse Reflectance Imaging with Astronomical Applications Samuel W. Hasinoff  

E-print Network

Diffuse Reflectance Imaging with Astronomical Applications Samuel W. Hasinoff TTIC Anat Levin reconstruction method based on high-resolution photography, taking advantage of visi- bility changes near of visibility coding, analogous to the amplitude masks used in computational photography [29, 10]. This coding

Freeman, William T.

95

Camera-based reflectivity measurement for solar thermal applications  

E-print Network

Camera-based reflectivity measurement for solar thermal applications John D. Pye1 , Clifford K. Ho2@sandia.gov Abstract We assess the ability of standard digital single-lens reflex cameras to provide accurate estimates Tubular receivers for solar thermal power plants, specifically tower plants, are in common use, in plants

96

Application of Confocal Microscopy for 3D Assessment of Carotid Plaque Structure: Implications for Carotid Blood Flow and Stroke Research  

PubMed Central

Background: Little information is available on how forces resulting from fluid flow interact with structural stability of carotid atherosclerotic plaque and how such interactions may impact on stroke prevention; investigation of the 3D structure of plaque could help in such studies. The aim of this study was to investigate whether confocal microscopy can be used to obtain 3D visualization of the structure of atherosclerotic carotid plaques. Methods: Carotid plaque specimens were collected from routine end-arterectomy surgical operations. Both bright-field microscopy and Laser Scanning Confocal Microscopy (LSCM) were used to generate 3D image data-sets and visualizations of surgically removed carotid plaques. Results: Evidence of carotid plaque vulnerability was demonstrated by reduced fibrous cap thickness and large lipid-necrotic core with evidence of cracking. Conclusion: The generation of 3D images of carotid plaques could help in: (i) investigating key features that affect plaque structural stability; (ii) comparing 3D microstructure of the plaque with clinical imaging assessment and blood flow investigations; and (iii) developing markers to identify patients requiring clinical intervention. PMID:22518263

Khattab, Ahmed; Wertheim, David; Petford, Nick; Kirk, Ruth; Wijesinghe, Lasantha; Ali, Ibtisam

2011-01-01

97

Fiber optic confocal microscope: In vivo precancer detection  

NASA Astrophysics Data System (ADS)

Cancer is a significant public health problem worldwide. Many cancers originate as precancerous lesions in the epithelium which, when removed in sufficient time, can prevent progression to cancer. However, current detection techniques are typically time-consuming and expensive, limiting their acceptance and accessibility. Optical techniques, such as confocal microscopy, have significant potential to provide clinicians with real-time, high-resolution images of cells and tissue without tissue removal. These images of cell morphology and tissue architecture can be used to characterize tissue and determine the presence or extent of precancer and cancer. This dissertation explores the instrumentation and application of fiber optic reflectance confocal microscopy for in vivo precancer detection. The first part of the dissertation presents in vivo imaging of suspicious lesions in the human uterine cervix and oral mucosa using a fiber bundle based confocal microscope with a complex glass miniature objective lens. Images are analyzed quantitatively and qualitatively to determine the potential of this technology in vivo. An analysis of nuclear density from images of 30 cervical epithelium sites shows differentiation between normal and precancerous sites. Similarly, images from 20 oral mucosa sites demonstrate changes in nuclear density and tissue architecture indicative of progression of precancer and cancer. In addition to this multi-fiber confocal microscope used with a glass objective lens for the clinical studies, imaging of tissue samples has been accomplished with the same confocal system using an injection molded plastic miniature objective lens demonstrating comparable optical quality for a significantly less expensive optical component. Finally, a benchtop prototype of a single fiber confocal microscope using a gimbaled two-axis MEMS scanner has been designed and constructed. Imaging of a resolution target and cellular samples demonstrates sufficient resolution and field of view for cellular imaging. The results from the imaging studies presented here indicate that in vivo confocal microscopy has the potential to improve early precancer detection in epithelial tissue. Advances in imaging technology will continue to reduce the cost of imaging systems and improve the imaging capability, leading to an inexpensive, real-time, minimally-invasive tool for in vivo imaging.

Carlson, Kristen Dawn

98

Reflections  

NSDL National Science Digital Library

In this quick activity, Dracula has a hole in his house and learners help solve the problem by using a mirror and protractor to reflect incoming light out of his house. This activity introduces learners to vocabulary associated with light and optics including reflected ray, angle of incident, and angle of reflection. This Dracula-themed activity also works well during Halloween.

Carlyn Little

1997-01-01

99

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

100

Application of confocal Raman microscopy to investigate casein micro-particles in blend casein/pectin films.  

PubMed

Pectin triggers formation of casein micro-particles during solution casting. Confocal Raman microscopy revealed their composition and spatial dimension in resulting films. Peaks in the Raman spectra corresponded to those found in films prepared by either casein or pectin. This suggested that no conformational changes occurred after mixing. Raman images revealed incompatibility of both polymers because particles consisted of casein only and the surrounding matrix of pectin. Deformation of micro-particles into an oblate shape took place during film formation. In dried films, an empty space between casein and pectin was found in lateral dimension. In contrast, casein micro-particles overlapped with the pectin matrix in the vertical dimension. PMID:25482531

Zhuang, Yu; Sterr, Julia; Kulozik, Ulrich; Gebhardt, Ronald

2015-03-01

101

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

102

High-speed multispectral confocal biomedical imaging  

PubMed Central

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

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

2014-01-01

103

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. PMID:24298422

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

104

33 CFR 148.708 - Must the applicant's proposal reflect potential regulations?  

Code of Federal Regulations, 2010 CFR

...Must the applicant's proposal reflect potential regulations? 148.708 Section 148...Must the applicant's proposal reflect potential regulations? Although a regulation...to minimize the subsequent impact that potential regulations may have on a licensee,...

2010-07-01

105

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. PMID:24058698

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

2013-01-01

106

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.

107

Confocal Microscopy Denis Semwogerere  

E-print Network

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

Weeks, Eric R.

108

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

109

Feasibility of digitally stained multimodal confocal mosaics to simulate histopathology  

NASA Astrophysics Data System (ADS)

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

Gareau, Daniel S.

2009-05-01

110

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

111

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. PMID:23163262

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

2014-01-01

112

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

113

Application of confocal Raman spectroscopy to thin polymer layers on highly scattering substrates: a case study of synthetic adhesives on historic textiles  

Microsoft Academic Search

This study considers confocal Raman spectroscopy asa means of identifyinga range of synthetic polymeric adhesives used in textile conservation. Many of the synthetic adhesives applied to support fragile textiles in the 1970s are now showing signs of ageing and the textiles are therefore being presented for retreatment. With no record of the adhesive used, conservators are unsure of the appropriate

A. M. Macdonald; A. S. Vaughan; P. Wyeth

2005-01-01

114

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

115

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

116

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

117

Any Way You Slice ItA Comparison of Confocal Microscopy Techniques  

PubMed Central

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

Jonkman, James

2015-01-01

118

Confocal microscopy and exfoliative cytology  

PubMed Central

Context: Early detection of potentially malignant lesions and invasive squamous-cell carcinoma in the oral cavity could be greatly improved through techniques that permit visualization of subtle cellular changes indicative of the neoplastic transformation process. One such technique is confocal microscopy. Combining rapidity with reliability, an innovative idea has been put forward using confocal microscope in exfoliative cytology. Aims: The main objective of this study was to assess confocal microscopy for cytological diagnosis and the results were compared with that of the standard PAP stain. Settings and Design: Confocal microscope, acridine orange (AO) stain, PAP (Papanicolaou) stain. The study was designed to assess confocal microscopy for cytological diagnosis. In the process, smears of patients with (clinically diagnosed and/or suspected) oral squamous cell carcinoma as well as those of controls (normal people) were stained with acridine orange and observed under confocal microscope. The results were compared with those of the standard PAP method. Materials and Methods: Samples of buccal mucosa smears from normal patients and squamous cell carcinoma patients were made, fixed in 100% alcohol, followed by AO staining. The corresponding set of smears was stained with PAP stain using rapid PAP stain kit. The results obtained were compared with those obtained with AO confocal microscopy. Results: The study had shown nuclear changes (malignant cells) in the smears of squamous cell carcinoma patients as increased intensity of fluorescence of the nucleus, when observed under confocal microscope. Acridine orange confocal microscopy showed good amount of sensitivity and specificity (93%) in identifying malignant cells in exfoliative cytological smears. Conclusion: Confocal microscopy was found to have good sensitivity in the identification of cancer (malignant) cells in exfoliative cytology, at par with the PAP method. The rapidity of processing and screening a specimen resulted in saving of time. It added a certain amount of objectivity to the process of arriving at a diagnosis. PMID:24250082

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

2013-01-01

119

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

120

Reflective and transflective liquid crystal displays for low-power mobile applications  

Microsoft Academic Search

We describe the main features of current reflective and transflective liquid crystal displays (LCDs) for low-power mobile applications. The reflective LCD is relatively simple but not readable in dark environment, and the transflective LCD involves complicated fabrication processes. We demonstrate two types of transflective liquid crystal displays (LCDs) in a single gap geometry to overcome these problems. One type of

Jinyool Kim; Chang-Jae Yu; Dong-Woo Kim; Sin-Doo Lee

2005-01-01

121

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

122

Wideband energy reflectance measurements: Effects of negative middle ear pressure and application of a pressure compensation  

E-print Network

Wideband energy reflectance measurements: Effects of negative middle ear pressure and application become popular as a tool for evaluating mid- dle ear function. Negative middle ear pressure (MEP) is a prevalent form of middle ear dysfunction, which may impact application of ER measurements in differential

Allen, Jont

123

Develop statewide recommendations for application of PCC joint reflective cracking rehabilitation strategies  

E-print Network

in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE August 2004 Major Subject: Civil Engineering ii DEVELOP STATEWIDE RECOMMENDATIONS FOR APPLICATION OF PCC JOINT REFLECTIVE CRACKING... (Member) (Head of Department) August 2004 Major Subject: Civil Engineering iii ABSTRACT Develop Statewide Recommendations for Application of PCC...

Jain, Rahul Padamkumar

2004-11-15

124

Spectrally encoded slit confocal microscopy.  

PubMed

A simple and cost-effective method for real-time imaging in confocal microscopy is proposed. Spectrally encoded slit confocal microscopy (SESCoM) uses a spectral encoding technique together with a confocal slit aperture to achieve two-dimensional images. Simulation and experimental results of the SESCoM's axial and lateral performances are presented. The measured FWHM of the axial response is 1.15 mum when an objective with a NA of 0.95 is used. FWHMs of the lateral line spread functions are measured to be 236 and 244 nm along the x and y directions, respectively. Both the axial and the lateral experimental results agree well with the simulation results. PMID:16688262

Kim, Jeongmin; Kang, DongKyun; Gweon, DaeGab

2006-06-01

125

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

126

Compact ultrafast reflective Fabry-Perot tunable lasers for OCT imaging applications  

Microsoft Academic Search

We demonstrate a novel reflective Fabry-Perot tunable laser (RFPTL) for high speed swept-source optical coherence tomography (OCT) imaging applications. This external cavity semiconductor laser uses a silicon MEMS tunable Fabry- Perot filter in a novel reflective mode of operation. The laser is packaged in a compact 25x15 mm fiber-pigtailed butterfly package. Lasers at 1060 and 1300 nm wavelengths have been

Mark Kuznetsov; Walid Atia; Bart Johnson; Dale Flanders

2010-01-01

127

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...

128

Confocal luminescence microscopy study of defect-domain wall interaction in lithium niobate and its application to light-induced domain engineering  

NASA Astrophysics Data System (ADS)

Understanding the mutual interaction of extrinsic and intrinsic defects with the ferroelectric domain walls of LiNbO3 is the key to achieve domain patterns on the sub-micron scale. For that reason the influence of domain inversion on the Er3+ defect was investigated in a detailed study, in which energetic shifts and changes in the intensity ratio of individual Er3+ sites were found. The results led to an improved model describing the Er3+ defect in LiNbO3 and to the introduction of a concept of an atomistic probe. This atomistic probe allows the determination of the orientation of the ferroelectric axis by means of optical spectroscopy and allows three-dimensional imaging of domain structures with high spatial resolution without topographic artifacts. For this purpose a confocal luminescence microscope was developed, adapted to allow investigation at low temperature and applied electric fields. Based on the concept of an atomistic probe, the interaction of Er and Ti dopants was investigated, and significant spectral broadening and line shifting were found. Calibrating these changes to the [Ti4+]-concentration allows imaging of [Ti4+]-profiles, as found in integrated optical devices. The [Ti4+]-concentration profile can be imaged without artifacts caused by topology, intensity fluctuations, or variations in the [Er3+]-concentration profile. A novel approach was introduced for directly writing ferroelectric domain patterns into LiNbO3 substrates using the confocal microscope to focus visible light from an argon ion laser to a diffraction limited spot. It was shown that space charge fields, created by light with a wavelength of 488nm, can reduce the external applied field needed for domain inversion by up to 30%. So far, structures with a period down to 8mum have been demonstrated. In-situ experiments during domain inversion demonstrated the possibility to monitor the domain inversion process in-situ with a temporal resolution of up to t = 7ms. It could be demonstrated that the width of the domain wall region is different for static and dynamic measurements and that the reconfiguration of the defect structures and the lattice takes place on time scales of 0.5s to a few seconds.

Sandmann, Christian

129

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

130

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

Albrechtov, Jana; Jancek, Jir; Lhotkov, Zuzana; Radochov, Barbora; Kubnov, Lucie

2007-01-01

131

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

132

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. PMID:19269331

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

2009-01-01

133

ALTERNATIVES TO USING A REFERENCE STRIP FOR REFLECTANCE-BASED NITROGEN APPLICATION IN CORN  

Technology Transfer Automated Retrieval System (TEKTRAN)

Excess nitrogen application on corn fields result in increased potential for nitrogen loss to ground or surface waters, while reducing the amount of nitrogen applied creates a risk of diminished productivity and lower yields. Crop canopy reflectance sensor technology for optimizing nitrogen applicat...

134

NEW APPLICATIONS OF NEAR-INFRARED REFLECTANCE SPECTROSCOPY FOR FORAGE QUALITY ASSESSMENT  

Technology Transfer Automated Retrieval System (TEKTRAN)

Near-infrared reflectance spectroscopy (NIRS) has now been used in agriculture, specifically for forage quality analysis, for about 30 years. Due to its speed, many new applications have been developed, including medicine and pharmaceuticals. It is a secondary technique that requires proper calibrat...

135

Uniform Illumination Design by Configuration of LED Array and Diffuse Reflection Surface for Color Vision Application  

Microsoft Academic Search

Illumination uniformity and color mixing results are essential for color vision applications. In this paper, an indirect methodisproposedfortheuniformillumination,andamathemati- cally simulated algorithm is developed. We integrate the method of light-emitting diode (LED) array and diffuse reflection surface for uniform illumination system. By considering each single LED as an imperfect Lambertian emitter, we discuss the irradiance distri- bution over a sphere's inner

Zhen-min Zhu; Xing-hua Qu; Guo-xin Jia; Jian-fei Ouyang

2011-01-01

136

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

E-print Network

The application of an ultrasonic shear wave reflection method for nondestructive testing of cement for Nondestructive Testing of Cement-Based Materials at Early Ages An Experimental and Numerical Analysis by Dr for Nondestructive Testing of Cement-Based Materials at Early Ages ­ An Experi- mental and Numerical Analysis ist

137

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. PMID:22169101

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

2012-01-01

138

Tracheobronchial Amyloidosis and Confocal Endomicroscopy  

Microsoft Academic Search

Tracheobronchial amyloidosis is one of many causes of endobronchial stenosis and nodularity, the concrete diagnosis of which currently requires the finding of apple-green birefringence from endobronchial biopsies. Bronchoscopic probe-based confocal endomicroscopy (pCLE) is a novel optical biopsy technique which provides real-time images of the lattice structure of the bronchial basement membrane a finding lost in malignancy. This case study

Richard C. Newton; Samuel V. Kemp; Guang-Zhong Yang; Ara Darzi; Mary N. Sheppard; Pallav L. Shah

2011-01-01

139

Confocal Raman microspectroscopy of the skin.  

PubMed

Confocal Raman spectroscopy is a technique with considerable potential for the non-invasive study of biological tissues and skin samples in vitro or in vivo. It can be used to study skin physiology and possible pathological conditions and to obtain data about molecular composition and the structure of skin, for example, water content, moisturization and changes in the skin barrier function can all be observed. In-depth measurements also allow biopharmaceutical studies, such as analyzing the rate of penetration of a drug and the biochemical changes that may be induced by an applied formulation. Confocal Raman microspectroscopy is now at such a stage of refinement that it opens up new vistas. The big leap forward in its ease of use enables this technology to be used as an analytical method by more and more non-specialist laboratories. This review gives an overview of the state of the art of this technology by presenting an update on the principles of Raman spectroscopy and then by looking at examples of new developments in in vivo and in vitro applications. PMID:21914580

Frster, Matthias; Bolzinger, Marie-Alexandrine; Montagnac, Gilles; Brianon, Stphanie

2011-01-01

140

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. PMID:24143300

Templeton, Adam

2013-01-01

141

Reciprocity principle applicable to reflected radiance measurements and the searchlight problem.  

PubMed

In a recent paper by Di Girolamo et al. [J. Geophys. Res. D 103, 8795 (1998)] a heuristic argument was used to derive a reciprocity principle applicable to reflected solar radiation measurements. Here a formal derivation of this reciprocity principle is presented. It is also demonstrated that a purely spatial reciprocal relationship exists between one-dimensional radiative transfer theory and the three-dimensional searchlight problem for horizontally homogeneous media. PMID:18319908

Di Girolamo, L

1999-05-20

142

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

143

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

NASA Astrophysics Data System (ADS)

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

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

2003-04-01

144

Confocal mosaicing microscopy in Mohs skin excisions: feasibility of rapid surgical pathology  

PubMed Central

Mosaicing of confocal images enables observation of nuclear morphology in large areas of tissue. An application of interest is rapid detection of basal cell carcinomas (BCCs) in skin excisions during Mohs surgery. A mosaic is currently created in less than 9 min, whereas preparing frozen histology requires 20 to 45 min for an excision. In reflectance mosaics, using acetic acid as a contrast agent to brighten nuclei, large and densely nucleated BCC tumors were detectable in fields of view of 12 12 mm (which is equivalent to a 2-magnified view as required by Mohs surgeons). However, small and sparsely nucleated tumors remained undetectable. Their diminutive size within the large field of view resulted in weak light backscatter and contrast relative to the bright surrounding normal dermis. In fluorescence, a nuclear-specific contrast agent may be used and light emission collected specifically from nuclei but almost none from the dermis. Acridine orange of concentration 1 mM stains nuclei in 20 s with high specificity and strongly enhances nuclear-to-dermis contrast of BCCs. Comparison of fluorescence mosaics to histology shows that both large and small tumors are detectable. The results demonstrate the feasibility of confocal mosaicing microscopy toward rapid surgical pathology to potentially expedite and guide surgery. PMID:19021381

Gareau, Daniel S.; Li, Yongbiao; Huang, Billy; Eastman, Zach; Nehal, Kishwer S.; Rajadhyaksha, Milind

2009-01-01

145

Confocal MicroscopyGuided Laser Ablation for Superficial and Early Nodular Basal Cell Carcinoma  

PubMed Central

Importance Laser ablation is a rapid and minimally invasive approach for the treatment of superficial skin cancers, but efficacy and reliability vary owing to lack of histologic margin control. High-resolution reflectance confocal microscopy (RCM) may offer a means for examining margins directly on the patient. Observations We report successful elimination of superficial and early nodular basal cell carcinoma (BCC) in 2 cases-, using RCM imaging to guide Er-:YAG laser ablation. Three-dimensional (3-D) mapping is feasible with RCM-, to delineate the lateral border and thickness of the tumor. Thus, the surgeon may deliver laser fluence and passes with localized controlie, by varying the ablation parameters in sub-lesional areas with specificity that is governed by the 3-D topography of the BCC. We further demonstrate intra-operative detection of residual BCC after initial laser ablation and complete removal of remaining tumor by additional passes. Both RCM imaging and histologic sections confirm the final clearance of BCC. Conclusions and Relevance Confocal microscopy may enhance the efficacy and reliability of laser tumor ablation. This report represents a new translational application for RCM imaging, which, when combined with an ablative laser, may one day provide an efficient and cost-effective treatment for BCC. PMID:24827701

Chen, Chih-Shan Jason; Sierra, Heidy; Cordova, Miguel; Rajadhyaksha, Milind

2014-01-01

146

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...

147

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

148

Meteorological applications of surface bidirectional reflectance distribution functions retrieved from satellite data  

NASA Astrophysics Data System (ADS)

Bidirectional reflectance distribution functions (BRDFs) quantify the manner in which terrestrial surfaces reflect incident solar radiation as a function of the view and illumination geometries. BRDFs allow for directional correction (normalization) of satellite radiance data via anisotropic correction factors to a standard view and illumination geometry. These clear-scene anisotropic correction factors are especially valuable in automated cloud detection models. After using BRDFs to predict clear-scene radiances for a given satellite overpass, actual scene radiance measurements can be compared with predictions. Pixels with reflectance observations that exceed predicted clear-scene values are identified as cloudy. Cloud detection results using this method repeatedly demonstrate high accuracies using near-infrared data collected by the NOAA-14 polar-orbiting satellite during August and September 1995 over New England. However, during this same period BRDF-predicted land-surface reflectances are of insufficient accuracy to estimate the atmospheric aerosol optical properties of cloud-free pixels. This is due primarily to a requirement for separating with high accuracy the atmospheric and surface contributions in top-of-atmosphere (TOA) satellite reflectance observations, a separation that depends strongly and sensitively on the absolute magnitude of the surface reflectance. BRDFs also provide for location-dependent albedos of the earth's surface on synoptic and global scales. Accurate mapping of albedo is required to model energy and mass exchange processes in atmospheric fluid dynamics and global climate models. The present constellation of meteorological satellites measures upwelling radiances over a large variety of illumination and viewing geometries, and is suitable for estimating BRDFs on global scales. Results demonstrate successfully the ability of contemporary "kernel-driven" BRDF models to quantify the observed directional dependence of solar energy reflected from the earth's surface as observed by the NOAA AVHRR and GOES-Next geostationary satellite imagers. This research is unique in its use of satellite bidirectional reflectance data, especially geostationary data, that have been adjusted for atmospheric scattering effects over large areas and under diverse illumination and viewing geometries. An immediate application of these research results is in the assessment of how well the current generation of land-surface BRDF models can meet the requirements of the NASA Earth Observing System Moderate Resolution Imaging Spectroradiometer (MODIS) sensor for accurate geometric normalization of directional radiance observations and the retrieval of visible and near-infrared albedos on a global scale.

D'Entremont, Robert Paul

149

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

PubMed

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

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

2013-11-01

150

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

151

Integrated photoacoustic, confocal, and two-photon microscope  

PubMed Central

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

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

2014-01-01

152

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

PubMed

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

Bonfanti, M S; Ghauharali, R I

2000-01-01

153

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

154

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

155

Submillimeter Confocal Imaging Active Module  

NASA Technical Reports Server (NTRS)

The term submillimeter confocal imaging active module (SCIAM) denotes a proposed airborne coherent imaging radar system that would be suitable for use in reconnaissance, surveillance, and navigation. The development of the SCIAM would include utilization and extension of recent achievements in monolithic microwave integrated circuits capable of operating at frequencies up to and beyond a nominal radio frequency of 340 GHz. Because the SCIAM would be primarily down-looking (in contradistinction to primarily side-looking), it could be useful for imaging shorter objects located between taller ones (for example, objects on streets between buildings). The SCIAM would utilize a confocal geometry to obtain high cross-track resolution, and would be amenable to synthetic-aperture processing of its output to obtain high along-track resolution. The SCIAM (see figure) would include multiple (two in the initial version) antenna apertures, separated from each other by a cross-track baseline of suitable length (e.g., 1.6 m). These apertures would both transmit the illuminating radar pulses and receive the returns. A common reference oscillator would generate a signal at a controllable frequency of (340 GHz + (Delta)f)/N, where (Delta)f is an instantaneous swept frequency difference and N is an integer. The output of this oscillator would be fed to a frequency- multiplier-and-power-amplifier module to obtain a signal, at 340 GHz + (Delta)f, that would serve as both the carrier signal for generating the transmitted pulses and a local-oscillator (LO) signal for a receiver associated with each antenna aperture. Because duplexers in the form of circulators or transmit/receive (T/R) switches would be lossy and extremely difficult to implement, the antenna apertures would be designed according to a spatial-diplexing scheme, in which signals would be coupled in and out via separate, adjacent transmitting and receiving feed horns. This scheme would cause the transmitted and received beams to be aimed in slightly different directions, and, hence, to not overlap fully on the targets on the ground. However, a preliminary analysis has shown that the loss of overlap would be small enough that the resulting loss in signal-to-noise ratio (SNR) would be much less than the SNR loss associated with the use of a 340-GHz T/R switch.

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

2009-01-01

156

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

E-print Network

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

Gimenez, Clayton C. (Clayton Christopher)

2014-01-01

157

Collinear optical coherence and confocal fluorescence microscopies for tissue engineering  

NASA Astrophysics Data System (ADS)

Tissue engineered medical products (TEMPs) are often three-dimensional (3D) hybrid materials consisting of a porous scaffold upon which the tissue is grown. However, monitoring of the developing tissue deep within the scaffold is hampered by its turbidity. We have sought new ways to probe the interior of the scaffold with the same resolution as conventional laser scanning confocal microscopy but with greater sensitivity. We present a novel application of optical coherence microscopy (OCM) by combining it with confocal fluorescence microscopy (CFM) togather simultaneous structural and functional information on TEMPs in a registered fashion. In this work, we describe the collinear OCM and CFM instrument. We demonstrate the utility of this dual-mode technique for TEMPs by imaging fluorescently stained osteoblasts cultured in a polymeric TEMP.

Dunkers, J. P.; Cicerone, M. T.; Washburn, N. R.

2003-11-01

158

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. PMID:19964286

Rajadhyaksha, Milind

2014-01-01

159

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

160

High-throughput, detailed, cell-specific neuroanatomy of dendritic spines using microinjection and confocal microscopy  

Microsoft Academic Search

Morphological features such as size, shape and density of dendritic spines have been shown to reflect important synaptic functional attributes and potential for plasticity. Here we describe in detail a protocol for obtaining detailed morphometric analysis of spines using microinjection of fluorescent dyes, high-resolution confocal microscopy, deconvolution and image analysis with NeuronStudio. Recent technical advancements include better preservation of tissue,

Alfredo Rodriguez; John H Morrison; Dani Dumitriu

2011-01-01

161

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 Gonzlez; Ernesto Gonzlez; W. Matthew White; Milind Rajadhyaksha; R. Rox Anderson

1999-01-01

162

Laser scanning confocal microscopy: a potential technique for the study of lithic microwear  

Microsoft Academic Search

The key problem restricting lithic microwear analysis is the lack of quantitative analysis to support qualitative assessments of different wear traces. This paper presents the reflective laser scanning confocal microscope (LSCM) as a new technique for the study of lithic microwear that has the potential to resolve this problem. Firstly, an example is presented that shows how the LSCM compares

Adrian A. Evans; Randolph E. Donahue

2008-01-01

163

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...

164

Quick Start FV1000CONFOCAL LASER SCANNING  

E-print Network

Quick Start FLUOVIEW FV1000CONFOCAL LASER SCANNING BIOLOGICAL MICROSCOPE FV10-ASWVer1.4 Petition40 3.10 3D Display laser system correctly, read instruction manuals that come with each laser equipment and light power

Meagher, Mary

165

Characterization of the main error sources of chromatic confocal probes for dimensional measurement  

NASA Astrophysics Data System (ADS)

Chromatic confocal probes are increasingly used in high-precision dimensional metrology applications such as roughness, form, thickness and surface profile measurements; however, their measurement behaviour is not well understood and must be characterized at a nanometre level. This paper provides a calibration bench for the characterization of two chromatic confocal probes of 20 and 350 m travel ranges. The metrology loop that includes the chromatic confocal probe is stable and enables measurement repeatability at the nanometer level. With the proposed system, the major error sources, such as the relative axial and radial motions of the probe with respect to the sample, the material, colour and roughness of the measured sample, the relative deviation/tilt of the probe and the scanning speed are identified. Experimental test results show that the chromatic confocal probes are sensitive to these errors and that their measurement behaviour is highly dependent on them.

Nouira, H.; El-Hayek, N.; Yuan, X.; Anwer, N.

2014-04-01

166

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

167

Confocal Raman Microspectroscopy of Oral Streptococci  

NASA Astrophysics Data System (ADS)

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

Beier, Brooke D.

168

Chromatic confocal microscopy using staircase diffractive surface.  

PubMed

A chromatic confocal microscope (CCM) is a high-dynamic-range noncontact distance measurement sensor; it is based on a hyperchromatic lens. The vast majority of commercial CCMs use refractive-based chromatic dispersion to chromatically code the optical axis. This approach significantly limits the range of applications and performance of the CCM. In order to be a suitable alternative to a laser triangulation gauge and laser encoder, the performance of the CCM must be improved. In this paper, it is shown how hybrid aspheric diffractive (HAD) lenses can bring the CCM to its full potential by increasing the dynamic range by a factor of 2 and the resolution by a factor of 5 while passively athermizing and increasing the light throughput efficiency of the optical head [M. Rayer, U.S. patent 1122052.2 (2011)]. The only commercially suitable manufacturing process is single-point diamond turning. However, the optical power carried by the diffractive side of a hybrid aspheric diffractive lens is limited by the manufacturing process. A theoretical study of manufacturing losses has revealed that the HAD configuration with the highest diffraction efficiency is for a staircase diffractive surface (SDS). SDS lenses have the potential to reduce light losses associated with manufacturing limits by a factor of 5 without increasing surface roughness, allowing scalar diffraction-limited optical design with a diffractive element. PMID:25320920

Rayer, Mathieu; Mansfield, Daniel

2014-08-10

169

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

170

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

SciTech Connect

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

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

2009-01-01

171

[Applications of near infrared reflectance spectroscopy technique (NIRS) to soil attributes research].  

PubMed

Soil is a much complicated substance, because animals, plants and microbes live together, organic and inorganic exist together. So soil contains a large amount of information. The traditional method in laboratory is a time-consuming effort. But the technology of near infrared reflectance spectroscopy (NIRS) has been widely used in many areas, owing to its rapidness, high efficiency, no pollution and low cost, NIRS has become the most important method to detect the composition of soil. This paper mainly introduce some traditional methods in laboratory, the basic processes of soil detection by NIRS, some algorithms for data preprocessing and modeling. Besides, the present paper illustrates the latest research progress and the development of portable near infrared instruments of the soil. According to this paper, the authors also hope to promote the application conditions of NIRS in the grassland ecology research in China, and accelerate the modernization of research measures in this area. PMID:25739200

Liu, Yan-De; Xiong, Song-Sheng; Liu, De-Li

2014-10-01

172

A New Artificial Dielectric Metamaterial and its Application as a THz Anti-Reflection Coating  

E-print Network

We describe a novel artificial dielectric material which has applications at millimetre and submillimetre wavelengths. The material is manufactured from layers of metal mesh patterned onto thin polypropylene sheets which are then bonded together using a hot pressing process to provide planar rugged discs which can be reliably cycled to cryogenic temperatures. The refractive index of this material can be tuned by adjusting the geometry and spacing of the metal-mesh layers. We demonstrate its usage by designing and characterising a broadband anti-reflection coating for a Z-cut crystalline Quartz plate. The coating was fabricated and applied to the quartz using the hot press technique and characterized using a Fourier Transform Spectrometer. The performance is shown to be in good agreement with HFSS and transmission line modelling results.

Zhang, Jin; Mauskopf, Philip; Moncelsi, Lorenzo; Savini, Giorgio; Whitehouse, Nicola; 10.1364/AO.48.006635

2011-01-01

173

Optical characterization and confocal fluorescence imaging of mechanochromic acrylate polymers  

NASA Astrophysics Data System (ADS)

The development of mechanochromic molecules has opened new pathways for the study of localized stress and failure in polymers. Their application as stress or temperature diagnostics, however, requires suitable measurement techniques capable of detecting the force- and temperature-sensitive chemical species with high spatial resolution. Confocal imaging techniques offer excellent spatial resolution but the energy input during these measurements can itself affect the activation state of the mechanochromic species. Here, we present a systematic study of the effects of laser-based imaging on the activation and fluorescence behavior of mechanochromic spiropyran (SP) integrated into poly(methyl acrylate) (PMA) and poly(methyl methacrylate) matrices using a confocal Raman microspectrometer. Localized stress and temperature activation were studied by means of high-rate compressive loading and dynamic fracture. Laser illumination of SP in PMA revealed a strong excitation wavelength- and power-dependence. Suitable correction functions were established and used to account for the observed laser effects. The presented study demonstrates that confocal imaging using conventional Raman spectrometers is a powerful characterization tool for localized stress analysis in mechanochromic polymers, offering quantifiable information on the activation state with high spatial resolution. However, laser-mechanophore interactions must be well understood and effects of laser excitation and exposure times must be taken into consideration when interpreting the obtained results.

van Horn, M.; Smith, P.; Mason, B. P.; Hemmer, J. R.; Read de Alaniz, J.; Hooper, J. P.; Osswald, S.

2015-01-01

174

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

175

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

PubMed Central

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. PMID:24737920

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

2014-01-01

176

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

SciTech Connect

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 [Beckman Laser Institute, University of California, Irvine, 1002 Health Sciences Road East, Irvine, California 92612 (United States); Department of Chemical Engineering and Materials Science, University of California, Irvine, Irvine, California 92697 (United States); Li, Rui [Beckman Laser Institute, University of California, Irvine, 1002 Health Sciences Road East, Irvine, California 92612 (United States); Ma, Teng; Kirk Shung, K.; Zhou, Qifa [Department of Biomedical Engineering, NIH Ultrasonic Transducer Resource Center, University of Southern California, Los Angeles, California 90089 (United States); Chen, Zhongping, E-mail: z2chen@uci.edu [Beckman Laser Institute, University of California, Irvine, 1002 Health Sciences Road East, Irvine, California 92612 (United States); Department of Chemical Engineering and Materials Science, University of California, Irvine, Irvine, California 92697 (United States); Department of Biomedical Engineering, University of California, Irvine, Irvine, California 92697 (United States)

2014-03-24

177

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 (Villanae, 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; Gmez-Laserna, Olivia; Aramendia, Julene; Arana, Gorka; Madariaga, Juan Manuel

2014-08-14

178

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

NASA Astrophysics Data System (ADS)

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 (Villanae, 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.

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

2014-08-01

179

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

180

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

181

TelePresence Confocal Laser Scanning Microscopy.  

PubMed

The advent of the Internet has allowed the development of remote access capabilities to a growing variety and number of microscopy systems. To date, the confocal microscope has not been included among these systems. At the California State University (CSU) Confocal Microscopy Core Facility, we have established a remote access confocal laser scanning microscope facility that allows users with virtually any type of computer platform to connect to our system. Our Leica TCS NT confocal system is accessible to any authorized user via the Internet by using a free software program called VNC (Virtual Network Computing). Once connectivity is established, remote users are able to control virtually all the functions to conduct real-time image analysis and quantitative assessments of their specimen. They can also move the motorized stage to view different regions of their specimen by using a software program associated with the stage. At the end of the session, all files generated during the session can be downloaded to the user's computer from a link on the CSU confocal website. A number of safeguard features have been developed to ensure security and privacy of data acquired during a remote session. PMID:12597815

Youngblom, Janey H.; Youngblom, James J.; Wilkinson, Jerry

2001-05-01

182

Confocal microlaparoscope for imaging the fallopian tube  

NASA Astrophysics Data System (ADS)

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

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

2014-11-01

183

Confocal mosaicing microscopy of basal-cell carcinomas ex vivo: progress in digital staining to simulate histology-like appearance  

NASA Astrophysics Data System (ADS)

Confocal mosaicing microscopy enables rapid imaging of large areas of fresh tissue, without the processing that is necessary for conventional histology. Using acridine orange (1 milliMolar, 20 seconds) to stain nuclei, basal cell carcinomas were detected in fluorescence confocal mosaics of Mohs surgical excisions with sensitivity of 96.6% and specificity of 89.2%. A possible barrier toward clinical acceptance is that confocal mosaics are based on a single mode of contrast and appear in grayscale, whereas histology is based on two (hematoxylin for nuclei, eosin for cellular cytoplasm and dermis) and appears purple-and-pink. Toward addressing this barrier, we report progress in developing a multispectral analytical model for digital staining: fluorescence confocal mosaics, which show only nuclei, are digitally stained purple and overlaid on reflectance confocal mosaics, which show only cellular cytoplasm and dermis, and digitally stained pink, to mimic the appearance of histology. Comparison of digitally stained confocal mosaics by our Mohs surgeon to the corresponding Mohs histology shows good correlation for normal and tumor detail. Digitally stained confocal mosaicing microscopy may allow direct examination of freshly excised tissue and serve as an adjunct for rapid pathology at-the-bedside.

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

2011-03-01

184

Radius measurement by laser confocal technology.  

PubMed

A laser confocal radius measurement (LCRM) method is proposed for high-accuracy measurement of the radius of curvature (ROC). The LCRM uses the peak points of confocal response curves to identify the cat eye and confocal positions precisely. It then accurately measures the distance between these two positions to determine the ROC. The LCRM also uses conic fitting, which significantly enhances measurement accuracy by restraining the influences of environmental disturbance and system noise on the measurement results. The experimental results indicate that LCRM has a relative expanded uncertainty of less than 10 ppm for both convex and concave spheres. Thus, LCRM is a feasible method for ROC measurements with high accuracy and concise structures. PMID:24921872

Yang, Jiamiao; Qiu, Lirong; Zhao, Weiqian; Zhang, Xin; Wang, Xu

2014-05-01

185

Three-dimensional confocal optical imagery of precambrian microscopic organisms.  

PubMed

A major difficulty that has long hindered studies of organic-walled Precambrian microbes in petrographic thin sections is the accurate documentation of their three-dimensional morphology. To address this need, we here demonstrate the use of confocal laser scanning microscopy. This technique, both non-intrusive and non-destructive, can provide data by which to objectively characterize, in situ and at submicron-scale resolution, the cellular and organismal morphology of permineralized (petrified) microorganisms. Application of this technique can provide information in three dimensions about the morphology, taphonomy, and fidelity of preservation of such fossils at a spatial resolution unavailable by any other means. PMID:16551223

Schopf, J William; Tripathi, Abhishek B; Kudryavtsev, Anatoliy B

2006-02-01

186

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

187

Examination of galectin localization using confocal microscopy.  

PubMed

Confocal microscopy provides a unique modality to examine the expression and localization of biomolecules in a variety of settings. Using this technique, an image is acquired from the focal plane of the objective using focused laser light, making it possible to work within the resolution limit of the optical system. In addition, by acquiring multiple images from a variety of focal planes, stacked series of images can provide clear spatial localization of a probed structure or protein. We describe herein the immunofluorescence methods for galectin staining in frozen sections of tissue for galectin localization using confocal microscopy. PMID:25253152

Cerri, Daniel Giuliano; Arthur, Connie M; Rodrigues, Llian Cataldi; Fermino, Marise Lopes; Rocha, Lenaldo Branco; Stowell, Sean R; Baruffi, Marcelo Dias

2015-01-01

188

VIIRS reflective solar bands calibration changes and potential impacts on ocean color applications  

NASA Astrophysics Data System (ADS)

The VIIRS (Visible-Infrared Imaging Radiometer Suite) instrument onboard the Suomi NPP (National Polar-orbiting Partnership) spacecraft started acquiring Earth observations in November 2011. Since then, radiometric calibration applied to the VIIRS RSB (Reflective Solar Band) measurements for the SDR (Sensor Data Record) production has been improved several times. In this paper, timeline of the main upgrades to the calibration software and parameters is compared with the changes of the radiometric coefficients applied in the operational production of the VIIRS SDR. Initially, radiometric calibration coefficients were updated once per week to correct for the responsivity degradation that occurs for some of the sensor's spectral bands due to contamination of the VIIRS telescope's mirrors. Despite the frequent updates, discontinuities in the radiometric calibration could still affect ocean color time series. In August 2012, magnitude of the radiometric coefficient changes was greatly reduced by implementing a procedure that predicts (about a week ahead) values of the calibration coefficients for each Earth scan until a subsequent update. The updates have been continued with the weekly frequency, and the coefficient prediction errors were monitored by comparisons with the initial invariant coefficients from the following week. The predicted coefficients were also compared with the coefficients derived once per orbit from the onboard solar diffuser measurements by an automated procedure implemented in the VIIRS data operational processing software. The paper evaluates the changes in the VIIRS RSB coefficient updates for bands M1 to M7 and potential impacts of these changes on ocean color applications.

Blonski, Slawomir; Cao, Changyong; Shao, Xi; Uprety, Sirish

2014-05-01

189

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

PubMed

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

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

2014-12-01

190

Anti-reflection properties of spherical top nanowire arrays for solar cell applications  

NASA Astrophysics Data System (ADS)

Nanowires (NW)/nanopillars (NP) have unique optical and electrical properties that make them attractive for photovoltaic applications. Important factors such as diameter, length and array density of the nanowires have investigated in the recent years or their effect on light trapping. In this work, we study the effect of varying the NWs top tip morphology, and find significant differences in optical response, both via simulations and experiments. In the simulations, optical performance of NW with flat top and spherical top were investigated. The simulated 3D model is a CNT/Cr/a-Si/ITO coaxial structure with total diameter of 760nm. Our results show that as the spacing of the NWgets smaller, the influence of the top morphology on the nanowires' reflectance becomes more significant. For narrow spacing arrays (p<2d, where p is the period and d is the diameter of NWs) NW device with spherical top shows better antireflection performance than the one with flat top. This is due to the biomimetic antireflection (AR) effect introduced by the spherical top . For large spacing arrays (p<2d), AR effect introduced by spherical tops was almost negligible. It can be ascribed to the low volume concentration of the spherical top comparing to that of the planar surface. In addition, effect of structural defects were also

Tao, Fei; Chen, Jiacheng; He, Feng; Zhou, Hang

2013-12-01

191

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. PMID:22264541

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

2012-01-01

192

Miniature objective lens with variable focus for confocal endomicroscopy.  

PubMed

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

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

2014-12-01

193

Miniature objective lens with variable focus for confocal endomicroscopy  

PubMed Central

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

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

2014-01-01

194

Skin optics revisited by in vivo confocal microscopy: melanin and sun exposure.  

PubMed

A new confocal prototype dedicated to the exploration of in vivo human skin has been constructed around a laser confocal module (Oz Noran, Inc.) and a skin contact device, assuring perfect stability of skin images. The power of the Argon/Krypton laser source has been limited to 2mW to secure safety, and the laser provides three visible wavelengths: 488, 568, and 647 nm. Optical sections were digitized at video rate, providing easy and rapid measurements of the thickness of epidermal layers and time-resolved information. Unexpected details of the epidermis were recorded with the blue laser line. Melanin provided strong reflection of the basal keratinocytes instead of the absorption expected. The 3D reconstruction of the melanin cap in basal keratinocytes confirmed the behavior of melanosomes acting as myriads of nanomirrors that reflected light. Confocal images of the posterior aspect of the forearm were recorded before sun exposure and then for one month after exposure. There was a 25% increase in the thickness of the stratum corneum. Bright inclusions into the dark nucleus of numerous spinous cells were interpreted as local condensation of chromatin. Numerous bright intercellular filaments were attributed to melanosomes filling up dendrites of melanocytes. A striking observation concerned the lack of melanosome caps in basal keratinocytes. In vivo confocal microscopy affords new insight to the role of melanin and its gradual migration after sun exposure. PMID:11382846

Corcuff, P; Chaussepied, C; Madry, G; Hadjur, C

2001-01-01

195

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

PubMed Central

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

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

2011-01-01

196

Quantitative phase-contrast confocal microscope.  

PubMed

We present a quantitative phase-contrast confocal microscope (QPCCM) by combining a line-scanning confocal system with digital holography (DH). This combination can merge the merits of these two different imaging modalities. High-contrast intensity images with low coherent noise, and the optical sectioning capability are made available due to the confocality. Phase profiles of the samples become accessible thanks to DH. QPCCM is able to quantitatively measure the phase variations of optical sections of the opaque samples and has the potential to take high-quality intensity and phase images of non-opaque samples such as many biological samples. Because each line scan is recorded by a hologram that may contain the optical aberrations of the system, it opens avenues for a variety of numerical aberration compensation methods and development of full digital adaptive optics confocal system to emulate current hardware-based adaptive optics system for biomedical imaging, especially ophthalmic imaging. Preliminary experiments with a microscope objective of NA 0.65 and 40 on opaque samples are presented to demonstrate this idea. The measured lateral and axial resolutions of the intensity images from the current system are ~0.64?m and ~2.70?m respectively. The noise level of the phase profile by QPCCM is ~2.4nm which is better than the result by DH. PMID:25089404

Liu, Changgeng; Marchesini, Stefano; Kim, Myung K

2014-07-28

197

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

198

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 ...

199

CONFOCAL MICROSCOPY SYSTEM PERFORMANCE: LASER POWER MEASUREMENTS  

EPA Science Inventory

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

200

Video-rate Scanning Confocal Microscopy and Microendoscopy  

E-print Network

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, ...

Nichols, Alexander J.

201

Revolutionize Your Confocal Imaging ZEISS LSM 880 with Airyscan  

E-print Network

marker) in blue, photoreceptor outer segments stained with FITC in green, EEA1 (endosomal marker) in red`Toole and P. Pryor, University of York, UK Confocal Airyscan Confocal Airyscan HeLa cells, Actin stained

Napp, Nils

202

Photometric Studies of Diffusely Reflecting Surfaces with Applications to the Brightness of the Moon  

Microsoft Academic Search

A series of light reflectivity measurements has been rnade on a variety of samples in a search for materials or surface textures which might reproduce the photometric properties of the lunar surface, particularly the pronounced rise of reflectivity at small phase angles. It has been found that most terrestrial substances, including standard diffusing surfaces, when observed with an instrument of

Philip Oetking

1966-01-01

203

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

204

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

205

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

206

Site-specific confocal fluorescence imaging of biological microstructures in a turbid medium  

NASA Astrophysics Data System (ADS)

Normally transparent biological structures in a turbid medium are imaged using a laser confocal microscope and multiwavelength site-specific fluorescence labelling. The spatial filtering capability of the detector pinhole in the confocal microscope limits the number of scattered fluorescent photons that reach the photodetector. Simultaneous application of different fluorescent markers on the same sample site minimizes photobleaching by reducing the excitation time for each marker. A high-contrast grey-level image is also produced by summing confocal images of the same site taken at different fluorescence wavelengths. Monte Carlo simulations are performed to obtain the quantitative behaviour of confocal fluorescence imaging in turbid media. Confocal images of the following samples were also obtained: (i) 15 m diameter fluorescent spheres placed 1.16 mm deep beneath an aqueous suspension of 0.0823 m diameter polystyrene latex spheres, and (ii) hindbrain of a whole-mount mouse embryo (age 10 days) that was stained to fluoresce at 515 nm and 580 nm peak wavelengths. Expression of RNA transcripts of a gene within the embryo hindbrain was detected by a fluorescence-based whole-mount in situ hybridization procedure that we recently tested.

Saloma, Caesar; Palmes-Saloma, Cynthia; Kondoh, Hisato

1998-06-01

207

Endoscope-compatible confocal microscope using a gradient index-lens system  

NASA Astrophysics Data System (ADS)

We present an endoscope-compatible confocal laser scanning microscope (CLSM) for medical imaging. A gradient index (GRIN)-lens system projects a magnified image on the distal end of a fiber-optic imaging bundle, which transfers the image to a CLSM situated at the proximal end. As the maximum diameter of the distal optics is 1 mm, application through the accessory channel of a conventional endoscope is possible. A lateral resolution of 3.1 ?m and an axial resolution of 16.6 ?m is achieved. Confocal images of colonic tissue stained with a fluorescent marker are shown.

Knittel, J.; Schnieder, L.; Buess, G.; Messerschmidt, B.; Possner, T.

2001-02-01

208

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

209

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

210

Characterizing tissue optical properties using confocal and low-coherence imaging  

Microsoft Academic Search

The signal from a confocal measurement as the focal volume is scanned down into a tissue yields an exponential decay versus depth (z_focus), signal = rho exp(-mu z_focus), where rho [dimensionless] is the local reflectivity and mu [1\\/cm] is an attenuation coefficient. A simple theory for how rho and mu depend on the optical properties of scattering (mu_s) and anisotropy

Steven L. Jacques; Daniel S. Gareau

2006-01-01

211

Effects of Fluorescein Staining on Laser In Vivo Confocal Microscopy Images of the Cornea  

PubMed Central

This study was designed to identify whether topical fluorescein, a common ophthalmic tool, affects laser in vivo confocal microscopy of the cornea, a tool with growing applications. Twenty-five eye care specialists were asked to identify presence or absence of fluorescein in 99 confocal micrographs of healthy corneas. Responses were statistically similar to guessing for the epithelium (48%??14% of respondents correct per image) and the subbasal nerve plexus (49%??11% correct), but results were less clear for the stroma. Dendritic immune cells were quantified in bilateral images from subjects who had been unilaterally stained with fluorescein. Density of dendritic immune cells was statistically similar between the unstained and contralateral stained eyes of 24 contact lens wearers (P = .72) and of 10 nonwearers (P = .53). Overall, the results indicated that fluorescein staining did not interfere with laser confocal microscopy of corneal epithelium, subbasal nerves, or dendritic immune cells. PMID:22363837

Sindt, Christine W.; Critser, D. Brice; Grout, Trudy K.; Kern, Jami R.

2012-01-01

212

A confocal micro-imaging system incorporating a thermally actuated two axis MEMS scanner  

NASA Astrophysics Data System (ADS)

For in-vivo imaging applications the use of conventional confocal microscope systems are simply not practical due to their relatively large size and weight. There is, however, great interest from both the life science research community and the clinical profession for the development of compact and portable micro-optical instrumentation capable of achieving minimally invasive, in-vivo imaging of tissue with sub-cellular resolution. In this paper we describe a novel confocal micro-imaging system incorporating, at its core, a thermally driven, non-resonant two-axis MEMS scanner which serves as a substitute for the two single-axis galvanometer scanners commonly used in standard confocal imaging systems. In this paper we describe the non-linearity of such devices and a number of techniques to compensate for this.

Poland, Simon P.; Li, Lijie; Uttamchandani, Deepak; Girkin, John M.

2009-02-01

213

The Development of a Medium Energy Ion Reflection Spectrometer and Some Problems Associated with its Application to Materials Analysis  

Microsoft Academic Search

This thesis reports on the development and characteristics of an ion reflection spectrometer designed to operate in the 20 - 150 KeV range with specific application to near surface analysis of solids. The work is divided into two parts.\\u000aPart I details the design, operation and calibration of the systems within the spectrometer. They include a high resolution electrostatic analyzer

William Frederick Skipper Poehlman

1980-01-01

214

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

215

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

216

Laser differential confocal paraboloidal vertex radius measurement.  

PubMed

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

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

2014-02-15

217

Digital confocal microscopy through a multimode fiber  

E-print Network

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

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

2015-01-01

218

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

219

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. PMID:22190845

Piyawattanametha, Wibool; Wang, Thomas D.

2011-01-01

220

Fluorescence confocal endomicroscopy in biological imaging  

Microsoft Academic Search

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

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

2007-01-01

221

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. PMID:24350574

2013-01-01

222

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

223

Particular features of the application of IR reflection spectroscopy methods in studies in archeology and paleontology  

NASA Astrophysics Data System (ADS)

We have considered an optical model of a porous rough surface with optical properties of objects (bone, flint) that are typical of archeology and paleontology. We have formulated an approach that makes it possible to perform mathematical processing of the IR reflection spectra of objects of this kind using standard algorithms and determine criteria that ensure obtaining reliable information on objects with a rough surface in the course of interpretation of frequencies in their IR reflection spectra. The potential of the approach has been demonstrated using as an example an investigation by the IR Fourier-transform reflection spectroscopy of mineralization processes of mammoth tusks from two paleolithic sites (14000 and 16000 BCE) located by the town of Yudinovo, Bryansk oblast, Russia.

Zolotarev, V. M.; Khlopachev, G. A.

2013-06-01

224

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 systems 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

225

Confocal microscopic analysis of morphogenetic movements.  

PubMed

Confocal microscopy is an excellent means of imaging cellular dynamics within living zebrafish embryos because it provides a means of optically sectioning tissues that have been labeled with specific fluorescent probe molecules. In order to study genetically encoded patterns of cell behavior that are involved in the formation of germ layers and various organ primordia, it is possible to vitally stain an entire zebrafish embryo with one or more fluorescent probe molecules and then examine morphogenetic behaviors within specific cell populations of interest using time-lapse confocal microscopy. There are two major advantages to this "bulk-labeling" approach: (1) the applied fluorescent probe (a contrast-enhancing agent) allows all of the cells within an intact zebrafish embryo to be rapidly stained; (2) the morphogenetic movements and shape changes of hundreds of cells can then be examined simultaneously in vivo using time-lapse confocal microscopy. The neutral fluorophore Bodipy 505/515 and its sphingolipid-derivative Bodipy-C5-ceramide are particularly useful, nonteratogenic vital stains for imaging cellular dynamics in living zebrafish embryos. These photostable fluorescent probes (when applied with 2% DMSO) percolate through the enveloping layer epithelium of the embryo, and localize in yolk-containing cytoplasm and interstitial space, respectively, owing to their different physiochemical characteristics. Bodipy-ceramide, for instance, remains highly localized to interstitial fluid once it accumulates within a zebrafish embryo, allowing the boundaries of deep cells to be clearly discerned throughout the entire embryo. Through the use of either of these fluorescent vital stains, it is possible to rapidly convert a developing zebrafish embryo into a strongly fluorescent specimen that is ideally suited for time-lapse confocal imaging. For zebrafish embryos whose deep cells have been intentionally "scatter-labeled" with fluorescent lineage tracers (e.g., fluorescent dextrans), sequential confocal z-series (i.e., focus-throughs) of the embryo can be rendered into uniquely informative 3D time-lapse movies using readily available image-processing programs. Similar time-lapse imaging, combined with rapidly advancing computer-assisted visualization techniques, may soon be applied to study the dynamics of GFP-fusion proteins in vivo, as well as other types of synthetic probe molecules designed to reveal the cytological processes associated with the patterning and morphological transformations of the zebrafish's embryonic tissues. PMID:9891361

Cooper, M S; D'Amico, L A; Henry, C A

1999-01-01

226

Classification of reflection matrices related to (super) Yangians and application to open spin chain models  

E-print Network

We present a classification of diagonal, antidiagonal and mixed reflection matrices related to Yangian and super-Yangian R matrices associated to the infinite series so(m), sp(n) and osp(m|n). We formulate the analytical Bethe Ansatz resolution for the so(m) and sp(n) open spin chains with boundary conditions described by the diagonal solutions.

D. Arnaudon; J. Avan; N. Crampe'; A. Doikou; L. Frappat; E. Ragoucy

2003-10-02

227

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

228

Reflection polarized light microscopy and its application to pyrolytic carbon deposits  

Microsoft Academic Search

The methods for the measurement of extinction angles by reflection polarized light microscopy were analyzed with respect to the investigation of pyrolytic carbon deposits. It is demonstrated that measurements of the extinction angle for deposits with circular morphology (e.g., a pyrolytic carbon layer on a fiber) must be strictly distinguished from the standard measurements of optically uniaxial materials with spatially

E. G. Bortchagovsky

2004-01-01

229

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

230

Research and Development Data to Define the Thermal Performance of Reflective Materials Used to Conserve Energy in Building Applications  

SciTech Connect

A comprehensive experimental laboratory study has been conducted on the thermal performance of reflective insulation systems. The goal of this study was to develop test and evaluation protocols and to obtain thermal performance data on a selected number of idealized and commercial systems containing reflective airspaces for use in analytical models. Steady-state thermal resistance has been measured on 17 different test panels using two guarded hot boxes. Additional instrumentation was installed to measure the temperature of critical locations inside the test panels. The test parameters which have been studied are heat flow direction (horizontal, up, and down), number of airspaces comprising the cavity, airspace effective emittance, airspace aspect ratio, airspace mean temperature and temperature difference, and the thermal resistance of the stud material. Tests have also been performed on similar constructions with mass insulation. Two one-dimensional calculation techniques (ASHRAE and proposed ASTM) have been employed to determine the cavity thermal resistance from the measured test panel results. The measured cavity thermal resistance is compared with literature data which is commonly employed to calculate the thermal resistance of reflective airspace assemblies. A consumer-oriented handbook pertaining to reflective insulation for building and commercial applications has also been prepared as part of this study.

Eisenberg, J

2001-04-09

231

OpenPING: a reflective middleware for the construction of adaptive networked game applications  

Microsoft Academic Search

The emergence of distributed Virtual Reality (VR) applications that run over the Internet has presented networked game application designers with new challenges. In an environment where the public internet streams multimedia data and is constantly under pressure to deliver over widely heterogeneous user-platforms, there has been a growing need that distributed VR applications be aware of and adapt to frequent

Paul Okanda; Gordon S. Blair

2004-01-01

232

Laser damage resistant multiband high reflective optics  

NASA Astrophysics Data System (ADS)

Laser durable multiband high reflective optics can be realized by depositing densified HfO2/SiO2 multilayers on aluminum alloy substrates. To further understand the impact of surface finishing and cleaning on laser-induced damage of multiband high reflective optics, 1" diameter witness samples were characterized by means of spectrophotometry, atomic force microscopy, confocal laser scanning microscopy, white light interferometry, scanning electron microscopy, and laser-induced damage threshold tests performed at 1064 nm, 20 ns, 20 Hz, and near normal angle of incidence. Laser-induced damage thresholds of 12.5 J/cm2 and 47 J/cm2 were obtained on a stained witness and unstained witness, respectively. A two-step laser damage process was proposed based on the post-damage analysis. The results suggest that nodule defects are the limiting factor for laser-induced damage thresholds. There exists the potential in aluminum-based dielectric coated multiband reflective optics for extremely high power laser applications.

Wang, Angela Q.; Wang, Jue; D'lallo, Michael J.; Platten, Jim E.; Roy, Brian P.; Orr, Michael; Crifasi, Joseph C.

2014-06-01

233

Confocal imaging of benign and malignant proliferative skin lesions in vivo  

NASA Astrophysics Data System (ADS)

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

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

1999-06-01

234

Imaging System With Confocally Self-Detecting Laser.  

DOEpatents

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

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

1996-10-08

235

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

236

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

237

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

238

TECHNICAL CONCEPT AND SOME POSSIBLE APPLICATIONS FOR HIGH-TEMPERATURE PARABOLIC BLIND-REFLECTING SOLAR CONCENTRATORS  

Microsoft Academic Search

There is a steady prejudice that the mirrors reflecting the light flux towards the source are necessary when the maximum possible one-stage concentration of solar radiation is required. The well-known parabolic dish collector is a most effective optical system among such mirrors. An alternative approach for creating the better-concentrating solar collectors is proposed and discussed in this paper. The optical

VIKTOR VASYLYEV

239

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

240

Application of Diffuse Reflectance FT-IR Spectroscopy for the Surface Study of Kevlar Fibers  

NASA Astrophysics Data System (ADS)

The surfaces of Kevlar-49 aramid fibers, being used in high-performance composite materials, have been characterized by diffuse reflectance Fourier transform infrared (FT-IR) spectroscopy. Enhancement of the surface selectivity of the technique has been achieved using KBr overlayers. The water absorbed by both the skin and the core of the fibers has been characterized by using this technique and the accessibility of the fiber functional groups has been evaluated.

Chatzi, E. G.; Ishida, H.; Koenig, J. L.

1985-12-01

241

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

Microsoft Academic Search

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 ?m) and the near-IR (0.84 ?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

Yoram J. Kaufman; Lorraine A. Remer

1994-01-01

242

Polymer Cholesteric-Liquid-Crystal (PCLC) Flake/Fluid Host Electro-Optical Suspensions and Their Applications in Color Flexible Reflective Displays  

SciTech Connect

Polymer cholesteric-liquid-crystal (PCLC) flake/fluid-host suspensions are a novel particle display technology for full-color reflective display applications on rigid or flexible substrates. These polarizing pigments require no polarizers or color filters, switch rapidly at very low voltages, and produce highly saturated colors with a reflection efficiency approaching 80%.

Marshall, K.L.; Trajkovska-Petkoska, A.; Hasman, K.; Leitch, M.; Cox, G.; Kosc, T.Z.; Jacobs, S.D.

2008-03-13

243

Reflective and refractive optical materials for earth and space applications; Proceedings of the Meeting, Orlando, FL, Apr. 4, 5, 1991  

NASA Technical Reports Server (NTRS)

The present conference discusses beryllium mirror design and fabrication, production of aspheric beryllium optical surfaces by HIP consolidation, the control of thermally induced porosity for the fabrication of beryllium optics, fine-grained beryllium optical coatings, light-absorbing beryllium baffle materials, and advanced broadband baffle materials. Also discussed are radiation-resistant optical glasses, a catalog of IR and cryooptical properties of selected materials, durable metal-dielectric mirror coatings, the optical stability of diffuse reflectance materials, and optical filters for space applications.

Riedl, Max J. (editor); Hale, Robert R. (editor); Parsonage, Thomas B. (editor)

1991-01-01

244

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

245

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. PMID:22132313

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

2011-01-01

246

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

PubMed

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

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

2014-08-15

247

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

248

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

E-print Network

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

Hiroshi Fujisaki; Yoshiaki Teranishi; Hiroki Nakamura

2002-11-22

249

CONFOCAL FABRY-PEROT INTERFEROMETER BASED HIGH SPECTRAL RESOLUTION LIDAR  

E-print Network

CONFOCAL FABRY-PEROT INTERFEROMETER BASED HIGH SPECTRAL RESOLUTION LIDAR by David Swick Hoffman....................................................................................3 Lidar............................................................................................................4 High Spectral Resolution Lidar

Lawrence, Rick L.

250

Nanometrology And Super-Resolution Imaging Of Oxide Isolation Structures Using A Confocal Scanning Laser Microscope  

NASA Astrophysics Data System (ADS)

A confocal scanning laser microscope (CSLM) has been used to study a variety of oxide isolation techniques including the LOCOS, S-LOCOS, SWAMI, and M-SWAMI structures. The focal plane sensitivity of the confocal microscope was used to deconvolve effects due to refraction, reflection, and interference of 488nm light propagating in these structures. Elementary optical theory due to Fraunhofer and Fizeau was used to rationalize the data and to permit correlation with physical profiles in both the lateral and vertical directions. We found that considerable enhancement of the instrumental precision could be obtained by adjusting the CSLM to operate at 8000X or greater magnification and by using a saturation threshold technique to acquire focal plane data. The signal-to-noise limited measurement capablity of the system appears to be about 0.07?m with standard deviations of 10%. The standard error of the mean over 49 linescan measurements is about one nanometer.

Monahan, Kevin M.; Chen, James

1988-01-01

251

Confocal scanning laser evaluation of repeated Q-switched laser exposure and possible retinal NFL damage  

NASA Astrophysics Data System (ADS)

Repeated extended source Q-switched exposure centered on the macula has been shown to produce a Bullseye maculopathy. This paper provides a confocal scanning laser ophthalmoscopic evaluation with regard to the retinal nerve fiber layer (NFL) and deeper choroidal vascular network. Confocal imaging revealed that the punctate annular appearance of this lesion in the deeper retinal layers is associated with retinal nerve fiber bundle disruptions and small gaps in the retinal NFL. No choroidal dysfunction was noticed with Indocyanine green angiography. It is hypothesized that retinal NFL damage occurs either through disruption of retinal pigment epithelial cell layer support to the NFL or through direct exposure to high spatial peak powers within the extended source beam profile, causing direct microthermal injury to the NFL. The apparent sparring of the fovea reflects central retinal morphology rather than a lack of retinal damage to the fovea.

Zwick, Harry; Gagliano, Donald A.; Zuclich, Joseph A.; Stuck, Bruce E.; Lund, David J.; Glickman, Randolph D.

1995-05-01

252

Achromatic reflection by long-pitch chiral-nematic liquid crystal and its application to displays switchable between reflective and transmissive modes  

NASA Astrophysics Data System (ADS)

We propose a chiral-nematic liquid crystal (CN-LC) device that reflects the infrared light, where the planar state is transparent over the entire visible wavelengths and the focal conic state scatters the light achromatically. The proposed CN-LC device can be operated at a low voltage because of the long pitch. A liquid crystal display (LCD) switchable between reflective and transmissive modes can be realized by stacking a CN-LC layer and a nematic LC layer.

Yoon, Tae-Hoon; Kim, Ki-Han; Song, Dong Han; Kim, Jae Chang

2011-03-01

253

Anti-resonant reflecting guidance in alcohol-filled hollow core photonic crystal fiber for sensing applications.  

PubMed

Mechanism and sensing applications of antiresonant reflecting guidance in an alcohol-filled simplified hollow-core (SHC) photonic crystal fiber (PCF) are demonstrated. By filling one air hole in the air cladding of the PCF with alcohol, anti-resonant reflecting guidance of light can be achieved and energy leakage of the core modes can be induced at resonant wavelengths of the Fabry-Prot (F-P) resonator formed by the alcohol-filled layer combined with the silica cladding in the cross-section of the PCF. The proposed structure exhibits periodic lossy dips in the transmission spectrum, of which the visibilities are sensitive to the refractive index of surrounding medium due to the reflectivity variation of the F-P resonator. Water level sensing is experimentally realized with this principle and the lossy dip exhibits a linear decrease against water level with a sensitivity of 1.1 dB/mm. The sensor is also sensitive to environmental temperature and a temperature sensitivity of -0.48 nm/C is obtained between room temperature and 60 C. PMID:24514741

Liu, Shuhui; Wang, Ying; Hou, Maoxiang; Guo, Jiangtao; Li, Zhihua; Lu, Peixiang

2013-12-16

254

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

NASA Astrophysics Data System (ADS)

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

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

2012-05-01

255

Initial studies of the bidirectional reflectance distribution function of carbon nanotube structures for stray light control applications  

NASA Astrophysics Data System (ADS)

The Bidirectional Reflectance Distribution Function (BRDF) at visible and near-infrared wavelengths of Multi-Wall Carbon NanoTubes (MWCNTs) grown on substrate materials are reported. The BRDF measurements were performed in the Diffuser Calibration Laboratory (DCaL) at NASA's Goddard Space Flight Center, and results at 500nm and 900nm are reported here. In addition, the 8 Directional/Hemispherical Reflectance of the samples is reported from the ultraviolet to shortwave infrared. The 8 Directional/Hemispherical Reflectance was measured in the Optics Branch at NASA's Goddard Space Flight Center. The BRDF was measured at 0 and 45 incident angles and from -80 to +80 scatter angles using a monochromatic source. The optical scatter properties of the samples as represented by their BRDF were found to be strongly influenced by the choice of substrate. As a reference, the optical scattering properties of the carbon nanotubes are compared to the BRDF of Aeroglaze Z306TM and Rippey Ultrapol IVTM, a well-known black paint and black appliqu, respectively. The possibility, promise, and challenges of employing carefully engineered carbon nanotubes in straylight control applications particularly for spaceflight instrumentation is also discussed.

Butler, James J.; Georgiev, Georgi T.; Tveekrem, June L.; Quijada, Manuel; Getty, Stephanie; Hagopian, John G.

2010-10-01

256

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

E-print Network

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

Cone, Michael Thomas

2014-04-16

257

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

2014-01-01

258

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

259

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

260

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

PubMed Central

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

Muoz Morales, Aarn A.; Vzquez y Montiel, Sergio

2012-01-01

261

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

PubMed

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

Tucker, James D

2015-01-01

262

The physical basis of total internal reflection fluorescence (TIRF) microscopy and its cellular applications.  

PubMed

Total internal reflection fluorescence (TIRF) microscopy has gained popularity in recent years among cell biologists due to its ability to clearly visualize events that occur at the adherent plasma membrane of cells. TIRF microscopy systems are now commercially available from nearly all microscope suppliers. This review aims to give the reader an introduction to the physical basis of TIRF and considerations that need to be made when purchasing a commercial system. We explain how TIRF can be combined with other microscopy modalities and describe how to use TIRF to study processes such as endocytosis, exocytosis, and focal adhesion dynamics. Finally, we provide a step-by-step guide to imaging and analyzing focal adhesion dynamics in a migrating cell using TIRF microscopy. PMID:25391791

Poulter, Natalie S; Pitkeathly, William T E; Smith, Philip J; Rappoport, Joshua Z

2015-01-01

263

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

NASA Astrophysics Data System (ADS)

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

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

2010-03-01

264

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

PubMed Central

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

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

2010-01-01

265

REFLECTANCE CALIBRATION OF FOCAL PLANE ARRAY HYPERSPECTRAL IMAGING SYSTEM FOR AGRICULTURAL AND FOOD SAFETY APPLICATIONS  

Technology Transfer Automated Retrieval System (TEKTRAN)

A method to calibrate a pushbroom hyperspectral imaging system for "near-field" applications in agricultural and food safety has been demonstrated. The method consists of a modified geometric control point correction applied to a focal plane array to remove smile and keystone distortion from the sy...

266

Reflectance Spectra of Fe-bearing Phyllosilicates: Applications to CM Chondrites  

NASA Astrophysics Data System (ADS)

The composition of the carbonaceous chondrites is dominated by a fine-grained opaque mineral mixture called matrix. In the lowest petrologic type C-chondrites significant alteration of matrix minerals has occured, resulting in compositions dominated by aqueous alteration products such as phyllosilicates, sulfates, oxides, hydroxides, and carbonates. The phyllosilicates top the list of abundant phases, and in the CM chondrites in particular, Fe-rich serpentines are the most important phases [e.g., 1]. King and Clark [2] have characterized the Mg-serpentines and chlorites, noting certain spectral similarities between chlorites and CI1 and CM2 chondrites. However, they found no exact spectral matches. We present here the results of an examination of the reflectance spectra of Fe-serpentines and two varieties of chamosite (chlorite group). We find these minerals can provide a reasonable spectral match to features seen in certain CM chondrites and by extension, the dark asteroids. We have measured the reflectance spectra of several different high-iron phyllosilicates. Samples were primarily obtained from the National Museum of Natural History (NMNH) with one extremely high iron chamosite provided by the University of Munster. Samples were hand picked and ground and measured in bidirectional reflectance from 0.3 to 25 micrometers. Samples were also characterized by x-ray. In the serpentine group we have measured samples of greenalite (Fe^2+,Fe^3+)(sub)2- 3(Si)2O(sub)5(OH)(sub)4, berthierine (Fe^2+,Fe^3+,Mg)(sub)2- 3(Si,Al)2O(sub)5(OH)4, and cronstedtite Fe^2+2Fe^3+(Si,Fe^3+)O5(OH)4. In the chlorite group we have measured two different samples of chamosite (Fe^2+,Mg,Fe^3+)(sub)5Al(Si(sub)3,Al)O(sub)10(OH,O)(sub)s. We have measured an additional Mg-serpentine amesite Mg(sub)2Al(Si,Al)O(sub)5(OH)(su)4, not examined by [2]. (Chemical formulas cited reflect the ideal given in [3].) For comparison to spectra of CM-type chondrites, samples of Murchison and Murray were available to us and these were also measured in reflectance from 0.3 to 25 micrometers. There are a number of spectral differences between the Fe- and Mg- serpentines, most notably that the Fe-bearing minerals lack the strong, narrow feature at 1.4 micrometers. They also lack the strong Mg-OH features between 2.2 and 2.4 micrometers. In addition several of the samples exhibit absorptions near 0.7 and 0.9 micrometers. The absence of the near-infrared features coupled with the presence of absorptions at the long end of the visible allows the Fe endmembers to provide a much better spectral match to near-infrared characterisitics of CM chondrites like Murchison and Nogoya. Additionally, the general slope characteristics below 0.58 micrometers in CM2 chondrites are also well matched by those observed in the Fe-serpentines, particularly the berthierine that we measured. Vilas and Gaffey [4] compared the absorptions near 0.7 and 0.9 micrometers in several CM chondrites with those observed in main- and outer-belt asteroids. They argued for a similar origin for the spectral features so Fe-phyllosilicates may contribute to the observed spectral characteristics of certain asteroids as well. In the infrared the spectra of CM chondrites Murray and Murchison are quite similar with broad absorptions at 3 micrometers, and from 8-12 micrometers, with a narrower feature centered on 6.2 micrometers. The Mg-serpentine, amesite, has abundant spectral features beyond 13 micrometers, which are not seen in the CM chondrite spectra. The Fe-serpentines have absorptions that can contribute to those seen in the CM chondrites, but lacks the large absorptions beyond 13 micrometers, again providing a better spectral match than the Mg-serpentines. In the future we hope to compare the spectra of these Fe- serpentines with a wider variety of CM chondrites. Additionally a theoretical modeling study is planned, which will attempt to match meteorite spectra using their mineralogy and grain size distribution as the initial input to the models. Acknowledgements: This work was begun while W. M. Calvin was a H

Calvin, W. M.; King, T. V. V.

1993-07-01

267

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...

268

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...

269

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.

James McDonald

2009-03-01

270

Vertical-type chiroptical spectrophotometer (I): instrumentation and application to diffuse reflectance circular dichroism measurement.  

PubMed

We have designed and built a novel universal chiroptical spectrophotometer (UCS-2: J-800KCMF), which can carry out in situ chirality measurement of solid samples without any pretreatment, in the UV-vis region and with high relative efficiency. The instrument was designed to carry out transmittance and diffuse reflectance (DR) circular dichroism (CD) measurements simultaneously, thus housing two photomultipliers. It has a unique feature that light impinges on samples vertically so that loose powders can be measured by placing them on a flat sample holder in an integrating sphere. As is our first universal chiroptical spectrophotometer, UCS-1, two lock-in amplifiers are installed to remove artifact signals arising from macroscopic anisotropies which are unique to solid samples. High performance was achieved by theoretically analyzing and experimentally proven the effect of the photoelastic modulator position on the CD base line shifts, and by selecting high-quality optical and electric components. Measurement of microcrystallines of both enantiomers of ammonium camphorsulfonate by the DRCD mode gave reasonable results. PMID:18681687

Harada, Takunori; Hayakawa, Hiroshi; Kuroda, Reiko

2008-07-01

271

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

272

Imaging White Adipose Tissue With Confocal Microscopy  

PubMed Central

Adipose tissue is composed of a variety of cell types that include mature adipocytes, endothelial cells, fibroblasts, adipocyte progenitors, and a range of inflammatory leukocytes. These cells work in concert to promote nutrient storage in adipose tissue depots and vary widely based on location. In addition, overnutrition and obesity impart significant changes in the architecture of adipose tissue that are strongly associated with metabolic dysfunction. Recent studies have called attention to the importance of adipose tissue microenvironments in regulating adipocyte function and therefore require techniques that preserve cellular interactions and permit detailed analysis of three-dimensional structures in fat. This chapter summarizes our experience with the use of laser scanning confocal microscopy for imaging adipose tissue in rodents. PMID:24480339

Martinez-Santibaez, Gabriel; Cho, Kae Won; Lumeng, Carey N.

2014-01-01

273

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

274

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

2007-02-01

275

Reflective Teaching  

ERIC Educational Resources Information Center

Thomas Farrell's "Reflective Teaching" outlines four principles that take teachers from just doing reflection to making it a way of being. Using the four principles, Reflective Practice Is Evidence Based, Reflective Practice Involves Dialogue, Reflective Practice Links Beliefs and Practices, and Reflective Practice Is a Way of Life,

Farrell, Thomas S. C.

2013-01-01

276

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

277

x-ray resonant magnetic reflectivity of stratified magnetic structures: eigen-wave formalism and application to a Fe thin film  

E-print Network

x-ray resonant magnetic reflectivity of stratified magnetic structures: eigen-wave formalism of electromagnetic waves by magnetic materials is pre- sented with an application. The formalism is applicable to retrieve the magnetic moment density along the depth of magnetic materials with arbitrary magnetic moment

278

Iron in Plagioclase: Synthesis Experiments with Applications to Lunar Reflectance Spectroscopy  

NASA Astrophysics Data System (ADS)

Plagioclase is the most abundant mineral on the Moons surface, comprising >90% of the anorthositic rocks that dominate the crust as primary crystallization products of the lunar magma ocean. Understanding the compositional variability of plagioclase across the lunar surface may inform various aspects of the Moons evolution, such as the extent of homogeneity of magma ocean crystallization, or the effect of low-grade metamorphism on mineral chemistry during prolonged cooling. Information about plagioclase compositions can be obtained remotely from near-infrared reflectance (NIR) data, which is sensitive to the particular coordination environment of Fe2+ cations in the mineral structure. As high spatial and spectral resolution NIR data have only recently begun to come available for the Moon, robust laboratory characterizations of the compositional controls on the optical properties of plagioclase are now necessary. Here we present preliminary results of experiments to synthesize various plagioclase compositions under lunar conditions. Powdered synthetic anorthite and albite glasses were used as endmember starting materials, and mixed in varying proportions with controlled amounts of Fe2O3. The mixtures were homogenized by melting at 1550C in a platinum capsule, and quenched in air after 2 hours. Samples were then sintered at 1400C for at least 24 hours in a gas-mixing furnace (CO/CO2) at a pO2~2^-10. Electron microprobe analyses confirm that the anorthite and albite starting endmembers can be combined and homogenized with sufficient accuracy to generate well-controlled plagioclase compositions, and that the sintering process allows the Fe2+ to be incorporated into the plagioclase homogenously. No contaminating phases have been observed. While previous laboratory and remotely-sensed NIR reflectance data typically show only one prominent Fe2+ absorption band (near 1250 nm) [e.g. Adams and Goullaud, 1978], the spectra of samples presented here display an additional major absorption centered at ~2000 nm. Both absorptions are present in spectra of samples with varying Na content (anorthite and bytownite compositions), diffusion time (one day and one week), and cooling rate (1 and 8 degrees C per minute). These results are consistent with Fe2+ cations being distributed between two coordination environments in plagioclase [e.g., Appleman et al., 1971; Hofmeister and Rossman, 1984]. Future spectral analyses of these samples will provide more quantitative constraints on the relative distribution of Fe2+ within the mineral structure. Additionally, we have begun a set of experiments to more closely examine the role of plagioclase bulk FeO content in directly controlling the relative strengths of the two prominent absorption bands. To do this, we are synthesizing a series of plagioclases with constant An# that have varying FeO contents. The results of this systematic investigation are intended to provide a basis for extracting compositional information from remote measurements of plagioclase on the lunar surface.

Cheek, L.; Parman, S. W.; Pieters, C. M.

2010-12-01

279

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

280

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

281

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

282

Generalized ray matrix for spherical mirror reflection and its application in square ring resonators and monolithic triaxial ring resonators.  

PubMed

To the best of our knowledge, the generalized ray matrix, an augmented 55 ray matrix for a spherical mirror reflection with all the possible perturbation sources including three kinds of displacements and its detailed deducing process have been proposed in this paper for the first time. Square ring resonators and monolithic triaxial ring resonators have been chosen as examples to show its application, and some novel results of the optical-axis perturbation have been obtained. A novel method to eliminate the diaphragm mismatching error and the gain capillary mismatching error in monolithic triaxial ring resonators more effectively has also been proposed. Both those results and method have been confirmed by related experiments and the experimental results have been described with diagrammatic representation. This generalized ray matrix is valuable for ray analysis of various kinds of resonators. These results are important for the cavity design, cavity improvement and alignment of high accuracy and super high accuracy ring laser gyroscopes. PMID:21451703

Yuan, Jie; Long, Xingwu; Chen, Meixiong

2011-03-28

283

3D image reconstruction using optical sectioning in confocal scanning microscopy  

NASA Astrophysics Data System (ADS)

Confocal scanning microscopy (CSM) has been used in biological application, materials science, semiconductor quality measurement and other non-destructive microscopic application. Small spot of light illuminates a sample, and a small detector that is ideally a point detector collects the reflected or transmitted light having the information of specimen. An image distribution can be reconstructed by a correlation analysis of spots with the high bandwidth. The mechanism for two-dimensional beam scanning and optical sectioning has an important role in CSM as the three-dimensional profiler. The parasitic motion of focus on the detector gives rise to the fatal distortion of an image profile named the extinction effect while using acousto-optical (AO) deflector. The intensity profile for the open loop scanning should be matched with its response for the standard. The non-linearity can be minimized with the optical sectioning or the optical probe of the closed loop control. This paper shows the mathematical expression of the light such as the extinction curve in the optical fields of system using AO deflector, the axial/lateral response experimentally when the error sources change, and the methods of optical sectioning. We propose the progressive methods for the high quality image as the following. At first, for having the corrected image, small spot and long scan range, this paper shows that the optimal design having the multi-objects can be used by choosing the unitary lens device in CSM. At second, in order to compensate for the intensity cancellation at the end profile that may be the cause of waviness for the optical image, this paper shows that it is efficient to schedule the frequency of scan. According to characteristics of the extinction curve and axial/lateral response having the error property, we can define the frequency and sensitivity of as their robustness. Finally, the axial response gives an important motive for the optical section, and the limit of object depth. The edge enhancement may be a fatal defeat to the reconstruction of image and sensitive to the conditions of specimen such as slope, irregular reflectivity, shape, etc. That means that the intensity profile for the open loop scanning method should be matched with its response to a perfect mirror as specimen, which can be minimized with the optical sectioning or the optical probe of the closed loop control.

Seo, Jungwoo; Kang, Dong Kyun; Park, Sunglim; Gweon, Dae gab

2001-10-01

284

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

285

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. PMID:19925674

2009-01-01

286

Variable-rate nitrogen application algorithm based on canopy reflected spectrum and its influence on wheat  

NASA Astrophysics Data System (ADS)

This study was to develop the time-specific and time-critical method to overcome the limitations of traditional field sampling methods for variable rate fertilization. Farmers, agricultural managers and grain processing enterprises are interested in measuring and assessing soil and crop status in order to apply adequate fertilizer quantities to crop growth. This paper focused on studying the relationship between vegetation index (OSAVI) and nitrogen content to determine the amount of nitrogen fertilizer recommended for variable rate management in precision agriculture. The traditional even rate fertilizer management was chosen as the CK. The grain yield, ear numbers, 1000-grain weight and grain protein content were measured among the CK, uniform treatments and variable rate fertilizer treatments. It indicated that variable rate fertilization reduced the variability of wheat yield, ear numbers and dry biomass, but it didn't increased crop yield and grain protein content significantly and did not decrease the variety of 1000-grain weight, compared to traditional rate application. The nitrogen fertilizer use efficiency was improved, for this purpose, the variable rate technology based on vegetation index could be used to prevent under ground water pollution and environmental deterioration.

Liang, Hongxia; Zhao, Chunjiang; Huang, Wenjiang; Liu, Liangyun; Wang, Jihua; Ma, Youhua

2005-01-01

287

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

288

Storage of megawatt laser pulses in a 4.5 m long confocal Fabry-Perot resonator  

Microsoft Academic Search

Storage of ns MW dye laser pulses in a folded, confocal Fabry-Perot resonator of 4.5-m length is described. A p-polarized pulse enters the resonator through a polarizing beam splitter placed at the folding angle, passes an activated electrooptic Q-switch thereby experiencing a rotation to s-polarization, and is reflected from a cavity mirror. The second Q-switch transit leaves the s-polarization unaffected

J. Berger; P. Blatt; P. Hauck; R. Neumann

1986-01-01

289

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

PubMed Central

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

Sun, Hui; Kurtz, Ronald

2012-01-01

290

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

PubMed

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

Sun, Hui; Kurtz, Ronald; Juhasz, Tibor

2012-08-01

291

Evaluation of the cell depleted layer of blood flow in vitro using confocal microscopic PIV method  

NASA Astrophysics Data System (ADS)

In the present study, we employed the laser scanning confocal microscope to image entire blood flow with accurate red blood cell imaging of 0.001 mm spatial resolution. In vitro blood flow of rat with different hematocrit ratios was simulated inside a 100and 300-micron opaque tube. The scanning rate of confocal microscope was 30 fps with 500 x 500 pixels of image. As a result, we can obtain clear images of RBCs to which is enough to be used as tracer particle directly to get the velocity vector field of blood flow by performing particle image velocimetry (PIV) technique non-invasively. Based on the present novel optical application, we can easily indicate the presence of cell depleted layer of blood flow in vitro and its boundaries.

Lim, S. H.; Lee, H.; Lee, C. Y.; Park, C. W.

2010-02-01

292

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

293

Confocal laser endomicroscopy and immunoendoscopy for real-time assessment of vascularization in gastrointestinal malignancies  

PubMed Central

Gastrointestinal cancers represent a major cause of morbidity and mortality, with incomplete response to chemotherapy in the advanced stages and poor prognosis. Angiogenesis plays a crucial part in tumor growth and metastasis, with most gastrointestinal cancers depending strictly on the development of a new and devoted capillary network. Confocal laser endomicroscopy is a new technology which allows in vivo microscopic analysis of the gastrointestinal mucosa and its microvascularization during ongoing endoscopy by using topically or systemically administered contrast agents. Targeting markers of angiogenesis in association with confocal laser endomicroscopic examination (immunoendoscopy), as a future challenge, will add functional analysis to the morphological aspect of the neoplastic process. This review describes previous experience in endomicroscopic examination of the upper and lower digestive tract with emphasis on vascularization, resulting in a broad spectrum of potential clinical applications, and also preclinical research that could be translated to human studies. PMID:21218080

Gheonea, Dan Ionu?; Cr?n?, Tatiana; Ciurea, Tudorel; Popescu, Carmen; B?d?r?u, Anca; S?ftoiu, Adrian

2011-01-01

294

Confocal laser scanning microscopy using a frequency doubled vertical external cavity surface emitting laser.  

PubMed

We report on a frequency doubled 980 nm vertical external cavity surface emitting laser for applications in confocal laser scanning microscopy. The beam quality, wavelength flexibility, and low noise characteristics of this compact source make this prolific imaging technique an exemplary tool. Single pass frequency doubling via KNbO(3) was demonstrated, yielding 1.8 mW at 490 nm with a near diffraction limited beam quality. Detailed analysis and comparison of the laser performance with the current standard argon ion laser revealed clear advantages of the solid-state source for confocal imaging. Imaging of fluorescein and eGFP labeled biological samples using the attenuated solid-state source provided high-resolution images at lower cost and with improved reliability. PMID:19044352

Esposito, Elric; Keatings, Stefanie; Gardner, Kyle; Harris, John; Riis, Erling; McConnell, Gail

2008-08-01

295

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

296

Reflection Coefficients.  

ERIC Educational Resources Information Center

Discusses and provides an example of reflectivity approximation to determine whether reflection will occur. Provides a method to show thin-film interference on a projection screen. Also applies the reflectivity concepts to electromagnetic wave systems. (MVL)

Greenslade, Thomas B., Jr.

1994-01-01

297

Compressed Sensing for Multispectral and Confocal Microscopy  

NASA Astrophysics Data System (ADS)

Compressive sensing is an emerging field based on the revelation that a small number of random linear projections of a signal or an image contain enough information for reconstruction of a high resolution one. This technique has been applied to magnetic resonance imaging and neutron scattering. We have previously developed an optical camera based on this concept which is capable of megapixel images while utilizing a single photodiode for acquisition and implemented through the use of a digital micromirror device to randomly modulate and acquire the necessary projections of the image. In addition, this scheme allows for the rapid acquisition of multispectral information. We are now extending this scheme to imaging beyond the visible spectrum into the infrared and terahertz where high resolution image sensors are much more costly. Lastly we will present a scheme for utilizing this method in confocal microscopy similar to the flying pinhole concept except that the individual pinhole is replaced by a complex random projection and reconstructed via linear programming.

Kelly, Kevin; Takhar, Dharmpal; Sun, Ting; Laska, Jason; Duarte, Marco; Baraniuk, Richard

2007-03-01

298

Optimization of confocal scanning laser ophthalmoscope design  

PubMed Central

Abstract. Confocal scanning laser ophthalmoscopy (cSLO) enables high-resolution and high-contrast imaging of the retina by employing spatial filtering for scattered light rejection. However, to obtain optimized image quality, one must design the cSLO around scanner technology limitations and minimize the effects of ocular aberrations and imaging artifacts. We describe a cSLO design methodology resulting in a simple, relatively inexpensive, and compact lens-based cSLO design optimized to balance resolution and throughput for a 20-deg field of view (FOV) with minimal imaging artifacts. We tested the imaging capabilities of our cSLO design with an experimental setup from which we obtained fast and high signal-to-noise ratio (SNR) retinal images. At lower FOVs, we were able to visualize parafoveal cone photoreceptors and nerve fiber bundles even without the use of adaptive optics. Through an experiment comparing our optimized cSLO design to a commercial cSLO system, we show that our design demonstrates a significant improvement in both image quality and resolution. PMID:23864013

LaRocca, Francesco; Dhalla, Al-Hafeez; Kelly, Michael P.; Farsiu, Sina; Izatt, Joseph A.

2013-01-01

299

8.G Reflecting reflections  

NSDL National Science Digital Library

This is a task from the Illustrative Mathematics website that is one part of a complete illustration of the standard to which it is aligned. Each task has at least one solution and some commentary that addresses important asects of the task and its potential use. Here are the first few lines of the commentary for this task: Below is a picture of a triangle on a coordinate grid: Draw the reflection of $\\triangle ABC$ over the line $x = -2$. Label the image of $A$ as $A^\\pri...

300

Use of In Vivo Confocal Microscopy in Malignant Melanoma: An Aid in Diagnosis and Assessment of Surgical and Nonsurgical Therapeutic Approaches  

Microsoft Academic Search

Background: Melanomas with poorly defined bor- ders,lackofpigmentation,lentiginousextension,andlo- cation in cosmetically sensitive regions represent diag- nostic and therapeutic challenges. Repeated surgical reexcisions are frequently required to achieve tumor- free margins. The use of reflectance mode confocal mi- croscopy as an noninvasive method has shown to be a promising tool for diagnosing pigmented lesions in vivo. Observations: We report 3 clinical cases

Clara Curiel-Lewandrowski; Christy M. Williams; Kirsty Joanna Swindells; Steven R. Tahan; Susie Astner; Robert A. Frankenthaler; Salvador Gonzalez

2004-01-01

301

CONFOCAL LASER SCANNING MICROSCOPY OF APOPTOSIS IN WHOLE MOUSE OVARIES  

EPA Science Inventory

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

302

CALIBRATION AND VALIDATION OF CONFOCAL SPECTRAL IMAGING SYSTEMS  

EPA Science Inventory

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

303

Automated Biofilm Region Recognition And Morphology Quantification From Confocal Laser  

E-print Network

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

Bouaynaya, Nidhal

304

Observing the Coral Symbiome Using Laser Scanning Confocal Microscopy  

NSDL National Science Digital Library

Christine E. Farrar and colleagues?? honorable mention video from the 2012 International Science and Engineering Visualization Challenge, hosted by Science Magazine and the U.S. National Science Foundation, uses confocal microscopy to demonstrate the dynamic lives of corals.

Christine E. Farrar (Hawai'i Institute of Marine Biology at the University of Hawai'i, Manoa; )

2013-02-01

305

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...

306

Tethered confocal endomicroscopy capsule for diagnosis and monitoring of eosinophilic esophagitis  

PubMed Central

Eosinophilic esophagitis (EoE) is an allergic condition that is characterized by eosinophils infiltrating the esophageal wall. The treatment of the disease may require multiple follow up sedated endoscopies and biopsies to confirm elimination of eosinophils. These procedures are expensive, time consuming, and may be difficult for patients to tolerate. Here we report on the development of a confocal microscopy capsule for diagnosis and monitoring of EoE. The swallowable capsule implements a high-speed fiber-based reflectance confocal microscopy technique termed Spectrally Encoded Confocal Microscopy (SECM). SECM scans the sample in one dimension without moving parts by using wavelength swept source illumination and a diffraction grating at the back plane of the objective lens. As the wavelength of the source is tuned, the SECM optics within the 7 x 30 mm capsule are rotated using a driveshaft enclosed in a 0.8 mm flexible tether. A single rotation of the optics covered a field of view of 22 mm x 223 m. The lateral and axial resolutions of the device were measured to be 2.1 and 14 m, respectively. Images of Acetic Acid stained swine esophagus obtained with the capsule ex vivo and in vivo clearly showed squamous epithelial nuclei, which are smaller and less reflective than eosinophils. Imaging of esophageal biopsies from EoE patients ex vivo demonstrated the capability of this technology to visualize individual eosinophils. Based on the results of this study, we believe that this capsule will be a simpler and more effective device for diagnosing EoE and monitoring the therapeutic response of this disease. PMID:24466487

Tabatabaei, Nima; Kang, DongKyun; Wu, Tao; Kim, Minkyu; Carruth, Robert W.; Leung, John; Sauk, Jenny S; Shreffler, Wayne; Yuan, Qian; Katz, Aubrey; Nishioka, Norman S; Tearney, Guillermo J.

2013-01-01

307

Elastic fluctuations as observed in a confocal slice  

E-print Network

Recent confocal experiments on colloidal solids motivate a fuller study of the projection of three-dimensional fluctuations onto a two-dimensional confocal slice. We show that the effective theory of a projected crystal displays several exceptional features, such as non-standard exponents in the dispersion relations. We provide analytic expressions for the effective two-dimensional elastic properties which allow one to work back from sliced experimental observations to three-dimensional elastic constants.

Claire A. Lemarchand; A. C. Maggs; Michael Schindler

2012-07-18

308

Probing chirality of a lipid tubular by confocal Raman microscopy.  

PubMed

The chiral phospholipids 1,2-bis-(10,12-tricosadiynoyl)-sn-glycero-3-phosphocholine (DC8,9 PC) can self assemble into lipid nanotubules. This hollow cylindrical supramolecular structure shows promise in a number of biotechnological applications. The mechanism of lipid tubule formation was initiated by assembling of lipid bilayer sheets from amphiphilic solution. Upon cooling, small ribbons were detached from the sheets and rolled up into helical tubules. The lipid tubules obtained were 0.6-0.8 microm in diameter and approximately 50 microm in length. Raman spectra of individual polymerized lipid tubules were measured by focused laser excitation of 532 nm leading to intense and reproducible Raman spectra. The chirality of lipid tubules was investigated by atomic force microscopy (AFM) and confocal Raman microscopy. We report the Raman mapping images revealing helical tubular profiles of C=C stretching and C[triple bond]C stretching of lipid tubules. Circular dichroism property of lipid tubules has also been probed with a 532 nm laser. PMID:21137899

Kiang-ia, Jarinee; Hailong, Hu; Bin, Yan; Jantippana, Yuwathida; Pantu, Piboon; Limtrakul, Jumras; Chattham, Nattaporn; Zexiang, Shen; Ting, Yu

2010-11-01

309

HIV neuropathy: an in vivo confocal microscopic study.  

PubMed

Several approaches exist for quantitative assessment of human immunodeficiency virus (HIV)-associated distal sensory polyneuropathy (DSP). While useful, each has some limitations. This study evaluated non-invasive, in vivo reflectance confocal microscopy (RCM) of Meissner corpuscles (MCs) as a measure of HIV-DSP. Forty-eight adults (29 HIV-infected, 19 controls) underwent RCM of MC density (MCs/mm(2)) at the arch, fingertip, and thenar eminence (TE); ankle skin biopsy to measure epidermal nerve fiber density (ENFD); electrophysiologic studies; and tactile, vibration, and thermal threshold testing. HIV+ subjects were clinically categorized as having DSP signs or no signs. MC densities were lower in HIV+ subjects with DSP signs than in controls (arch, p?=?0.0003; fingertip, p?

Almodovar, Jorge L; Schifitto, Giovanni; McDermott, Michael P; Ferguson, Michele; Herrmann, David N

2012-12-01

310

Total internal reflection (TIRF)-based quantification of procalcitonin for sepsis diagnosis--a point-of-care testing application.  

PubMed

A new, highly sensitive fluorescence immunoassay for a TIRF (total internal reflection)-based point-of-care testing (POCT) device was developed for the detection of procalcitonin (PCT), a specific and early marker for sepsis and microbial infections. The immunoassay was performed on a bench-top system that fulfilled all the necessary characteristics of a POCT application, including a short measurement time (<9 min), no sample pre-treatment requirements and application directly near patients. New rat monoclonal antibodies targeting PCT were screened and characterized. The best combinations of antibodies were then integrated into single-use cartridges, and the reduction of nonspecific binding was achieved by supplying suitable additives. Moreover, human recombinant PCT (hrPCT) for use as a standard was developed in the native form of hPCT in plasma (PCT1-116, PCT3-116). The assay achieves the required sensitivity range in human plasma to allow reliable differentiation between healthy persons and varying stages of infection severity (LOD=0.04 ng/mL; LOQ=0.12 ng/mL). Furthermore, the developed PCT assay can be applied in whole human blood with an adequate sensitivity (LOD=0.02 ng/mL; LOQ=0.09 ng/mL). To the best of our knowledge, this is the first diagnostic test for sepsis to use whole blood, which is a crucial requirement for POCT. We were able to detect native PCT in patient samples and showed a good correlation (R(2)=0.988) with the results of the Kryptor() device from BRAHMS, a state of the art device for the detection of PCT. PMID:24732603

Rascher, Daniela; Geerlof, Arie; Kremmer, Elisabeth; Krmer, Petra; Michael, Schmid; Hartmann, Anton; Rieger, Martin

2014-09-15

311

Polymer Cholesteric Liquid Crystal (PCLC) Flake/Fluid Host Suspensions: A Novel Electro-Optical Medium for Reflective Color Display Applications  

SciTech Connect

Polymer cholesteric liquid crystal (PCLC) flake/fluid host suspensions are a new and promising particle display technology for both full-color flexible display applications and electronic paper. Devices containing these "polarizing pigments" switch rapidly at very low voltages and produce highly saturated, circularly polarized reflectance colors without requiring polarizers or color filters.

Marshall, K.L.; Trajkovska-Petkoska, A.; Kosc, T.Z.; Jacobs, S.D.

2006-04-17

312

Tri-modal confocal margin screening for the presence of residual squamous cell carcinoma in Mohs surgical excisions  

NASA Astrophysics Data System (ADS)

Screening cancer in excision margins may be done with confocal microscopy to save time and cost over the gold standard histopathology (H&E). However, diagnostic accuracy requires sufficient contrast. Reflectance mode enables detection of large (>500um) nodular tumors. Enhanced nuclear contrast with acridine orange fluorescence mode additionally enables detection of tiny (<50um) basal cell carcinomas. Here, we present a novel combination of three modes to detect squamous cell carcinoma (SCC). Accurate screening of SCC requires eosin fluorescence, reflectance and acridine orange fluorescence to enable contrast for cytoplasm, collagen and nuclei respectively. Combining these signals replicates H&E for rapid clinical translation.

Bar, Anna; Snavely, Nicholas; Chen, Nathaniel; Jacques, Steven; Gareau, Daniel S.

2012-03-01

313

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

PubMed Central

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

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

1994-01-01

314

A Clinical and Confocal Microscopic Comparison of Transepithelial PRK and LASEK for Myopia  

PubMed Central

Purpose. To compare the clinical and confocal microscopic results of transepithelial PRK versus LASEK for correction of myopia. Materials and Methods. Twelve patients with myopia received transepithelial PRK in one eye and LASEK in the other. In transepithelial PRK-treated eyes, the corneal epithelium was removed with 40 microns of excimer laser ablation and in LASEK-treated eyes with 25-second application of 18% ethanol. Time to epithelial healing, ocular discomfort, uncorrected and best corrected visual acuities, manifest refraction, haze, greyscale value, and keratocyte apoptosis in confocal microscopy were recorded. Results. The mean time to epithelial healing was significantly longer after LASEK (4.00??0.43 versus 3.17??0.6 days). On day 1, ocular discomfort was significantly higher after transepithelial PRK. The grade of haze, keratocyte apoptosis, and greyscale value in confocal microscopy were significantly higher in transepithelial PRK-treated eyes at 1 month. All transepithelial PRK- and LASEK-treated eyes achieved 20/25 or better UCVA and were within 1.00?D of emmetropia at final visits. Conclusions. Both transepithelial PRK and LASEK offer effective correction of myopia at 1 year. However, LASEK appeared to induce less discomfort and less intense wound healing in the early postoperative period. PMID:25120924

Korkmaz, Safak; Bilgihan, Kamil; Sul, Sabahattin; Hondur, Ahmet

2014-01-01

315

Confocal soft X-ray scanning transmission microscopy: setup, alignment procedure and limitations.  

PubMed

Zone-plate-based scanning transmission soft X-ray microspectroscopy (STXM) is a well established technique for high-contrast imaging of sufficiently transparent specimens (e.g. ultrathin biological tissues, polymer materials, archaeometric specimens or magnetic thin films) with spatial resolutions in the regime of 20 nm and high spectroscopic or chemical sensitivity. However, due to the relatively large depth of focus of zone plates, the resolution of STXM along the optical axis so far stays unambiguously behind for thicker X-ray transparent specimens. This challenge can be addressed by the implementation of a second zone plate in the detection pathway of the beam, resulting in a confocal arrangement. Within this paper a first proof-of-principle study for a confocal STXM (cSTXM) and an elaborate alignment procedure in transmission and fluorescence geometry are presented. Based on first confocal soft X-ray micrographs of well known specimens, the advantage and limitation of cSTXM as well as further development potentials for future applications are discussed. PMID:25537596

Spth, Andreas; Raabe, Jrg; Fink, Rainer H

2015-01-01

316

In vivo molecular and morphological imaging by real time confocal mini-microscopy  

NASA Astrophysics Data System (ADS)

We evaluated a newly developed miniaturized confocal laser microscopy probe for real-time in vivo molecular and morphological imaging of normal, inflammatory, and malignant tissue in rodents. In the rigid mini-microscopy probe (diameter 7 mm), a single line laser delivers an excitation wavelength of 488 nm. Optical slice thickness is 7 ?m, lateral resolution 0.7 ?m. The range of the z-axis is 0 - 250 ?m below the tissue surface. Organ systems were examined in vivo in rodent models of human diseases. FITC-labeled Lycopersion esculentum lectin was injected or selected cell populations stained for molecular targeting. Morphological imaging was performed using fluorescein sodium, FITC-labeled dextran, and/or acriflavine hydrochloride. Cellular and subcellular details could be readily visualised in vivo at high resolution. Tissue characteristics of different organs were rendered at real time. Selective blood cell staining allowed observation of blood flow and cell migration. Inflammatory diseases such as hepatitis were diagnosed, and tumors were characterized under microscopic control in vivo. Confocal mini-microscopy allows real time in vivo molecular and morphological histologic imaging at high resolution of normal and diseased tissue. Since confocal microscopy is applicable to humans, this technology will have a high impact on different faculties in medicine.

Goetz, Martin; Gregor, Sebastian; Fottner, Christian; Garcia-Lazaro, Jose; Schirrmacher, Esther; Kempski, Oliver; Bartenstein, Peter; Weber, Mathias; Biesterfeld, Stefan; Galle, Peter R.; Neurath, Markus F.; Kiesslich, Ralf

2006-02-01

317

Confocal photothermal microscopy of thin films based on etalon and thermal lensing effects  

NASA Astrophysics Data System (ADS)

A photothermal apparatus with submicron resolution (~0.5 ?m) using a focused 532 nm pump beam is demonstrated. A coaxial probe (633 nm HeNe) detects changes in reflectivity. In addition to detecting modulation of the probes total reflected power caused by perturbation of the Fabry-Perot resonance, a pinhole in confocal geometry detects changes to the probe beam caused by thermal lensing. Based on signal-to-noise measurements made with a film of known absorption, a sensitivity of ~10 ppm is predicted with 200 mW of pump power. The instrument is applied to mapping of local absorption spikes in a Sc2O3 film and characterization of laser-induced ripple pattern in a HfO2 film.

Sun, Z.; Mansoori, A.; Zhang, X.; Emmert, L. A.; Patel, D.; Menoni, C. S.; Rudolph, W.

2013-11-01

318

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

PubMed Central

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

KAMALI, M.; DAY, L. J.; BROOKS, D. H.; ZHOU, X.; OMALLEY, D. M.

2009-01-01

319

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

NASA Astrophysics Data System (ADS)

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

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

2007-02-01

320

Reactivation Form Revised September 2014 Page 1 If you previously applied, you are required to submit this form. Your application record will be updated in our system to reflect your new application term.  

E-print Network

to submit this form. Your application record will be updated in our system to reflect your new application Page 2 Course # Course Name Credit Hours Course # Course Name Credit Hours Course # Course Name Credit students will receive a 50% tuition award in their final year of study. Guaranteed Rochester Accelerated

321

3D simultaneous refraction and reflection seismic tomography based on SIMUL with applications to the TRANSALP wide-angle data  

NASA Astrophysics Data System (ADS)

Applications of seismic travel time tomography are restricted for the most part either to the direct wave or to 2D. Based on the SIMULPS13Q version (Rietbrock, 1996) of the wide-spread SIMUL-code-family and the concepts of flexible gridding (Thurber, 1983-1999) we developed a simultaneous 3D inversion for slowness and reflector depth. The tomographic algorithm is based on an irregular model parametrization adjusted to the resolving power of the data and a damped LSQR matrix inversion. In a first step accuracy of the forward modeling has been improved, in particular for large recording distances, crucial for the inversion of PMP or Pn observations. In a second step the modelling of reflectors and reflections has been integrated and the simultaneous inversion has been extended to reflector depth nodes. Reflectors are modelled by bi-cubic splines and can be "floating", i.e. without impact on the velocities, or discontinuous. A wide variety of geological situations can be parameterized, from layered structures to almost vertical faults. The method has been applied to the TRANSALP refraction seismic data recorded in the Eastern Alps in 1998/99 (TRANSALP Working Group, 2001). The data consists of vibro- and explosion seismic signals recorded by 30 to 110 three-component stations distributed along a 220 km long segment of the profile. Vibroseis signals were observed in up to 80 km distance. Different 1D and 2D starting models converge to very similar results. We obtained a high resolution model of the upper crust with 2.5 kms horizontal grid spacing which has been used for migration of the near-vertical data. Resolution degrades significantly in greater depths. The inverted Moho is consistent with other results (TRANSALP Working Group, 2002). Rietbrock, A., 1996. Entwicklung eines Programmsystems zur konsistenten Auswertung grosser seismologischer Datensaetze mit Anwendung auf die Untersuchung der Absorptionsstruktur der Loma-Prieta-Region, Kalifornien. PhD-Thesis, University of Munich, 141 pp. Thurber, C.H., 1983. Earthquake locations and three-dimensional crustal structure in the Coyote Lake area, Central California. J. Geophys. Res. 88 (B10), 8226-8236 Thurber, C.H., Eberhart-Phillips, D., 1999. Local earthquake tomography with flexible gridding. Comp. Geosci. 25, 809-818 TRANSALP Working Group, 2001. European Orogenic Processes Research Transects the Eastern Alps, EOS 82 (40) TRANSALP Working Group, 2002. First deep seismic reflection images of the Eastern Alps reveal giant crustal wedges and transcrustal ramps. Geophys. Res. Let. 29 (10), 10.10129/2002GL014911

Bleibinhaus, F.; Gebrande, H.

2003-04-01

322

The Reflective Learning Continuum: Reflecting on Reflection  

ERIC Educational Resources Information Center

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

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

2005-01-01

323

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

NASA Astrophysics Data System (ADS)

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

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

2011-07-01

324

Science Experimenter: Reflectance Spectroscopy.  

ERIC Educational Resources Information Center

Provides construction details for a simple reflectometer that can be utilized for the observational technique known as reflectance spectroscopy. Includes background discussion, applications, calibrating techniques, and typical results. (JJK)

Mims, Forrest M., III

1991-01-01

325

Application of CO2 Snow Jet Cleaning in Conjunction with Laboratory Based Total Reflection X-Ray Fluorescence  

NASA Technical Reports Server (NTRS)

The Genesis mission was the first mission returning solar material to Earth since the Apollo program [1,2]. Unfortunately the return of the space craft on September 8, 2004 resulted in a crash landing, which shattered the samples into small fragments and exposed them to desert soil and other debris. Thus only small fragments of the original collectors are available, each having different degrees of surface contamination. Thorough surface cleaning is required to allow for subsequent analysis of solar wind material embedded within. An initial cleaning procedure was developed in coordination with Johnson Space Center which focused on removing larger sized particulates and a thin film organic contamination acquired during collection in space [3]. However, many of the samples have additional residues and more rigorous and/or innovative cleaning steps might be necessary. These cleaning steps must affect only the surface to avoid leaching and re-distribution of solar wind material from the bulk of the collectors. To aid in development and identification of the most appropriate cleaning procedures each sample has to be thoroughly inspected before and after each cleaning step. Laboratory based total reflection X-ray fluorescence (TXRF) spectrometry lends itself to this task as it is a non-destructive and surface sensitive analytical method permitting analysis of elements from aluminum onward present at and near the surface of a flat substrate [4]. The suitability of TXRF has been demonstrated for several Genesis solar wind samples before and after various cleaning methods including acid treatment, gas cluster ion beam, and CO2 snow jet [5 - 7]. The latter one is non-invasive and did show some promise on one sample [5]. To investigate the feasibility of CO2 snow jet cleaning further, several flown Genesis samples were selected to be characterized before and after CO2 snow application with sample 61052 being discussed below.

Schmeling, M.; Burnett, D. S.; Allton, J. H.; Rodriquez, M.; Tripa, C. E.; Veryovkin, I. V.

2013-01-01

326

Fused oblique incidence reflectometry and confocal fluorescence microscopy  

NASA Astrophysics Data System (ADS)

Confocal microendoscopy provides real-time high resolution cellular level images via a minimally invasive procedure, but relies on exogenous fluorophores, has a relatively limited penetration depth (100 ?m) and field of view (700 ?m), and produces a high rate of detailed information to the user. A new catheter based multi-modal system has been designed that combines confocal imaging and oblique incidence reflectometry (OIR), which is a non-invasive method capable of rapidly extracting tissue absorption, ?a, and reduced scattering, ?'s, spectra from tissue. The system builds on previous developments of a custom slit-scan multi-spectral confocal microendoscope and is designed to rapidly switch between diffuse spectroscopy and confocal fluorescence imaging modes of operation. An experimental proof-of-principle catheter has been developed that consists of a fiber bundle for traditional confocal fluorescence imaging and a single OIR source fiber which is manually redirected at +/- 26 degrees. Diffusely scattered light from each orientation of the source fiber is collected via the fiber bundle, with a frame of data representing spectra collected at a range of distances from the OIR source point. Initial results with intralipid phantoms show good agreement to published data over the 550-650 nm spectral range. We successfully imaged and measured the optical properties of rodent cardiac muscle.

Risi, Matthew D.; Rouse, Andrew R.; Gmitro, Arthur F.

2011-03-01

327

Reading Reflections  

NSDL National Science Digital Library

Reading reflections are designed to encourage students to complete readings before coming to class, to reflect more deeply on the content of the reading, to make personal meaning from the meaning, and to develop their metacognitive skills for lifelong learning. The reflections consist of three questions: (1) What is the main point of the reading?, (2) What information did you find surprising? Why?, and (3) What did you find confusing? Why? Students submit short responses to two of three questions prior to coming to class. Metacognitive components of the activity Reading reflections address many elements of metacognition, including knowledge, control, and reflection. Reading reflections are designed to help students develop knowledge about themselves as learners, learning tasks (reading), prior knowledge, content, self-monitoring, self-assessment, and reflection. Metacognitive goals The primary goals of this activity are to help students develop their skills of self-assessment, and to reflect more deeply on the content of their reading assignments. Reflective thinking is an essential element of expert learners, so this activity helps students develop skills as intentional learners for lifelong learning. Assessing students' metacognition Reading reflections (n = 35 in a typical semester) count for approximately 10% of the course grade. I do not grade these reflections, but give students credit if they are turned in on time (before class) and if they clearly demonstrate significant reflection.

Karl Wirth

328

A Simple Model for Nonlinear Confocal Ultrasonic Beams  

NASA Astrophysics Data System (ADS)

A confocally and coaxially arranged pair of focused transmitter and receiver represents one of the best geometries for medical ultrasonic imaging and non-invasive detection. We develop a simple theoretical model for describing the nonlinear propagation of a confocal ultrasonic beam in biological tissues. On the basis of the parabolic approximation and quasi-linear approximation, the nonlinear Khokhlov-Zabolotskaya-Kuznetsov (KZK) equation is solved by using the angular spectrum approach. Gaussian superposition technique is applied to simplify the solution, and an analytical solution for the second harmonics in the confocal ultrasonic beam is presented. Measurements are performed to examine the validity of the theoretical model. This model provides a preliminary model for acoustic nonlinear microscopy.

Zhang, Dong; Zhou, Lin; Si, Li-Sheng; Gong, Xiu-Fen

2007-01-01

329

In vivo evaluation of DSAEK interface with scanning-laser confocal microscopy  

PubMed Central

Background Descemet Stripping Automated Endothelial Keratoplasty (DSAEK) allows selective replacement of the endothelium. Post-operative haze and particles can affect the interface quality and, ultimately, visual outcome. In this study, we evaluated DSAEK interface with in vivo laser confocal microscopy (LCM) in order to: (i) correlate interface status with best corrected visual acuity, and (ii) with time from surgery; (iii) correlate interface particle number with best corrected visual acuity. Host-donor interface was imaged and graded using a published reflectivity scale. Particles at the interface were counted. Methods 18 eyes of 16 patients (6 males and 10 females); mean age: 74??8.3?years which underwent DSAEK were examined by means of in vivo laser confocal microscopy between 1 and 24?months after surgery. Host-donor interface was imaged and graded using a published reflectivity scale. Particles present at the interface were counted. Results Interface reflectivity was 2.17??1.2 and significantly correlated with visual acuity (Spearman correlation coefficient ?0.83; P?

2012-01-01

330

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

NASA Astrophysics Data System (ADS)

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

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

2012-05-01

331

Photometric phase functions of common geologic minerals and applications to quantitative analysis of mineral mixture reflectance spectra  

NASA Technical Reports Server (NTRS)

The mass fractional abundance of components in intimately mixed, particulate surfaces is calculated from laboratory reflectance spectra using Hapke's (1981) model for bidirectional reflectance. It is found that a simplified version of the model is accurate to within 7 percent for mixtures not containing low albedo components. The model is not appropriate for mixtures with very low and high albedo components. Consideration is given to the possible improvement of the method's accuracy by using an empirical single-particle phase function to describe the scattering characteristics of all minerals, or by solving for the single-particle phase function of the minerals involved exactly using extensive bidirectional reflectance measurements and Hapke's equations for bidirectional reflectance. Also, the results are used to examine the general scattering behavior of particulate mineral surfaces.

Mustard, John F.; Pieters, Carle M.

1989-01-01

332

Advances in the reduction and compensation of film stress in high-reflectance multilayer coatings for extreme ultraviolet lithography applications  

SciTech Connect

Due to the stringent surface figure requirements for the multilayer-coated optics in an extreme ultraviolet (EUV) projection lithography system, it is desirable to minimize deformation due to the multilayer film stress. However, the stress must be reduced or compensated without reducing EUV reflectivity, since the reflectivity has a strong impact on the throughput of a EUV lithography tool. In this work we identify and evaluate several leading techniques for stress reduction and compensation as applied to Mo/Si and Mo/Be multilayer films. The measured film stress for Mo/Si films with EUV reflectances near 67.4% at 13.4 nm is approximately - 420 MPa (compressive), while it is approximately +330 MPa (tensile) for Mo/Be films with EUV reflectances near 69.4% at 11.4 nm. Varying the Mo-to-Si ratio can be used to reduce the stress to near zero levels, but at a large loss in EUV reflectance (> 20%). The technique of varying the base pressure (impurity level) yielded a 10% decrease in stress with a 2% decrease in reflectance for our multilayers. Post-deposition annealing was performed and it was observed that while the cost in reflectance is relatively high (3.5%) to bring the stress to near zero levels (i.e., reduce by 1 00%), the stress can be reduced by 75% with only a 1.3% drop in reflectivity at annealing temperatures near 200{degrees}C. A study of annealing during Mo/Si deposition was also performed; however, no practical advantage was observed by heating during deposition. A new non-thermal (athermal) buffer-layer technique was developed to compensate for the effects of stress. Using this technique with amorphous silicon and Mo/Be buffer-layers it was possible to obtain Mo/Be and Mo/Si multilayer films with a near zero net film stress and less than a 1% loss in reflectivity. For example a Mo/Be film with 68.7% reflectivity at 11.4 nm and a Mo/Si film with 66.5% reflectivity at 13.3 nm were produced with net stress values less than 30 MPa.

Mirkarimi, P.B., LLNL

1998-02-20

333

Mosaicing of confocal microscopic in vivo soft tissue video sequences.  

PubMed

Fibered confocal microscopy allows in vivo and in situ imaging with cellular resolution. The potentiality of this imaging modality is extended in this work by using video mosaicing techniques. Two novelties are introduced. A robust estimator based on statistics for Riemannian manifolds is developed to find a globally consistent mapping of the input frames to a common coordinate system. A mosaicing framework using an efficient scattered data fitting method is proposed in order to take into account the non-rigid deformations and the irregular sampling implied by in vivo fibered confocal microscopy. Results on 50 images of a live mouse colon demonstrate the effectiveness of the proposed method. PMID:16685914

Vercauteren, Tom; Perchant, Aymeric; Pennec, Xavier; Ayache, Nicholas

2005-01-01

334

Full-field interferometric confocal microscopy using a VCSEL array  

PubMed Central

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

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

2014-01-01

335

Optimization of confocal laser induced fluorescence in a plasma  

NASA Astrophysics Data System (ADS)

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

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

2014-11-01

336

Optimization of confocal laser induced fluorescence in a plasma.  

PubMed

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

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

2014-11-01

337

Chromatic Confocal Electron Microscopy with a Finite Pinhole Size  

NASA Astrophysics Data System (ADS)

Scanning confocal electron microscopy (SCEM) is a new imaging mode in electron microscopy. Spherical aberration corrected electron microscope instruments fitted with two aberration correctors can be used in this mode which provides improved depth resolution and selectivity compared to optical sectioning in a conventional scanning transmission geometry. In this article, we consider the depth resolution and energy resolution in the confocal optical configuration for SCEM using inelastically scattered electrons with a finite pinhole size. We experimentally demonstrate energy-filtered optical sectioning in a double aberration-corrected instrument with uncorrected chromatic aberration without using a dedicated energy filter.

Wang, P.; Kirkland, A. I.; Nellist, P. D.

2012-07-01

338

Confocal Raman microscopy for identification of bacterial species in biofilms  

NASA Astrophysics Data System (ADS)

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

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

2011-03-01

339

Application of the specular and diffuse reflection analysis for in vitro diagnostics of dental erosion: correlation with enamel softening, roughness, and calcium release  

NASA Astrophysics Data System (ADS)

We present assembly and application of an optical reflectometer for the analysis of dental erosion. The erosive procedure involved acid-induced softening and initial substance loss phases, which are considered to be difficult for visual diagnosis in a clinic. Change of the specular reflection signal showed the highest sensitivity for the detection of the early softening phase of erosion among tested methods. The exponential decrease of the specular reflection intensity with erosive duration was compared to the increase of enamel roughness. Surface roughness was measured by optical analysis, and the observed tendency was correlated with scanning electron microscopy images of eroded enamel. A high correlation between specular reflection intensity and measurement of enamel softening (r2 >= -0.86) as well as calcium release (r2 >= -0.86) was found during erosion progression. Measurement of diffuse reflection revealed higher tooth-to-tooth deviation in contrast to the analysis of specular reflection intensity and lower correlation with other applied methods (r2 = 0.42-0.48). The proposed optical method allows simple and fast surface analysis and could be used for further optimization and construction of the first noncontact and cost-effective diagnostic tool for early erosion assessment in vivo.

Rakhmatullina, Ekaterina; Bossen, Anke; Hschele, Christoph; Wang, Xiaojie; Beyeler, Barbara; Meier, Christoph; Lussi, Adrian

2011-10-01

340

Application of the specular and diffuse reflection analysis for in vitro diagnostics of dental erosion: correlation with enamel softening, roughness, and calcium release  

PubMed Central

We present assembly and application of an optical reflectometer for the analysis of dental erosion. The erosive procedure involved acid-induced softening and initial substance loss phases, which are considered to be difficult for visual diagnosis in a clinic. Change of the specular reflection signal showed the highest sensitivity for the detection of the early softening phase of erosion among tested methods. The exponential decrease of the specular reflection intensity with erosive duration was compared to the increase of enamel roughness. Surface roughness was measured by optical analysis, and the observed tendency was correlated with scanning electron microscopy images of eroded enamel. A high correlation between specular reflection intensity and measurement of enamel softening (r2 ? ?0.86) as well as calcium release (r2 ? ?0.86) was found during erosion progression. Measurement of diffuse reflection revealed higher tooth-to-tooth deviation in contrast to the analysis of specular reflection intensity and lower correlation with other applied methods (r2 = 0.420.48). The proposed optical method allows simple and fast surface analysis and could be used for further optimization and construction of the first noncontact and cost-effective diagnostic tool for early erosion assessment in vivo. PMID:22029364

Rakhmatullina, Ekaterina; Bossen, Anke; Hschele, Christoph; Wang, Xiaojie; Beyeler, Barbara; Meier, Christoph; Lussi, Adrian

2011-01-01

341

Application of the specular and diffuse reflection analysis for in vitro diagnostics of dental erosion: correlation with enamel softening, roughness, and calcium release.  

PubMed

We present assembly and application of an optical reflectometer for the analysis of dental erosion. The erosive procedure involved acid-induced softening and initial substance loss phases, which are considered to be difficult for visual diagnosis in a clinic. Change of the specular reflection signal showed the highest sensitivity for the detection of the early softening phase of erosion among tested methods. The exponential decrease of the specular reflection intensity with erosive duration was compared to the increase of enamel roughness. Surface roughness was measured by optical analysis, and the observed tendency was correlated with scanning electron microscopy images of eroded enamel. A high correlation between specular reflection intensity and measurement of enamel softening (r(2) ? -0.86) as well as calcium release (r(2) ? -0.86) was found during erosion progression. Measurement of diffuse reflection revealed higher tooth-to-tooth deviation in contrast to the analysis of specular reflection intensity and lower correlation with other applied methods (r(2) = 0.42-0.48). The proposed optical method allows simple and fast surface analysis and could be used for further optimization and construction of the first noncontact and cost-effective diagnostic tool for early erosion assessment in vivo. PMID:22029364

Rakhmatullina, Ekaterina; Bossen, Anke; Hschele, Christoph; Wang, Xiaojie; Beyeler, Barbara; Meier, Christoph; Lussi, Adrian

2011-10-01

342

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

SciTech Connect

We report on a cost-effective optical setup for characterizing light-emitting semiconductor devices with optical-feedback confocal infrared microscopy and optical beam-induced resistance change.We utilize the focused beam from an infrared laser diode to induce local thermal resistance changes across the surface of a biased integrated circuit (IC) sample. Variations in the multiple current paths are mapped by scanning the IC across the focused beam. The high-contrast current maps allow accurate differentiation of the functional and defective sites, or the isolation of the surface-emittingp-i-n devices in the IC. Optical beam-induced current (OBIC) is not generated since the incident beam energy is lower than the bandgap energy of the p-i-n device. Inhomogeneous current distributions in the IC become apparent without the strong OBIC background. They are located at a diffraction-limited resolution by referencing the current maps against the confocal reflectance image that is simultaneously acquired via optical-feedback detection. Our technique permits the accurate identification of metal and semiconductor sites as well as the classification of different metallic structures according to thickness, composition, or spatial inhomogeneity.

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

2007-11-01

343

Confocal FRET and FLIM microscopy to characterize the distribution of transferrin receptors in membranes  

NASA Astrophysics Data System (ADS)

Previously, a confocal 'Forster' resonance energy transfer (FRET)-based assay has been used to establish a clustered organization for receptor-ligand complexes containing polymeric IgA-receptor or transferrin-receptor (TFR) during endocytic trafficking in polarized epithelial MDCK cells. Here, the experimental system has been extended to internalizing transferrin (Tfn) labeled with donor fluorophore (Alexa Fluor-488) and/or acceptor fluorophore (Alexa Fluor-555) and applying two-photon fluorescence lifetime imaging microscopy (FLIM)-FRET. The fluorescence lifetime distribution should provide insights, not available with confocal FRET, due to FLIM's ability to reflect the diverse micro-environments of the polarized endocytic pathway. This pilot study confirms that a range of fluorescence lifetime values are detected both in cells containing donor-labeled Tfn (single-label specimens) and cells containing both donor and acceptor-labeled Tfn (double-label specimens) at the level of the basolateral and peri-nuclear common endosomes. Furthermore, significant reduction is detected in the fluorescence lifetime in the presence of donor and acceptor -labeled TFR-Tfn receptor-ligand complexes, when compared with that of donor-labeled, confirming the existence of FRET among these complexes.

Wallrabe, Horst; Periasamy, Ammasi; Talati, Ronak; Kim, Christine; Barroso, Margarida

2006-02-01

344

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

NASA Astrophysics Data System (ADS)

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

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

2012-11-01

345

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

NASA Astrophysics Data System (ADS)

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

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

2011-09-01

346

Quantitative visualization of colloidal and intracellular gold nanoparticles by confocal microscopy.  

PubMed

Gold nanoparticles (AuNPs) have the potential to become a versatile biomarker. For further use of AuNPs labeled with functionalized molecules, their visualization in biological systems by routine laboratory tools such as light microscopy is crucial. However, the size far below the diffraction limit affords specialized parameters for microscopical detection, which stimulated the current study, aimed to determine from which size onward AuNPs, either in dispersion or cell-associated, can be reliably detected by standard confocal microscopy. First, gold colloids of size-restricted fractions are examined in dispersion. At a minimum particle size of 60 nm, detection appears to be reliable. Particle counts in dilution series confirm these results by revealing single particle detection of 60-nm colloids. Second, AuNPs are visualized and quantified in cells, which interestingly cause a phase shift in the reflection of AuNPs. Gold mass spectroscopy confirms the number of AuNPs counted microscopically inside cells. Furthermore, it demonstrates for the first time a very high diffusion rate of 15-nm particles into the cells. In conclusion, the results back the suitability of confocal microscopy for the quantitative tracking of colloidal and intracellular gold nanoparticles sized 60 nm. PMID:20615017

Klein, Sabine; Petersen, Svea; Taylor, Ulrike; Rath, Detlef; Barcikowski, Stephan

2010-01-01

347

Three-dimensional reconstruction of living mouse liver tissues using cryotechniques with confocal laser scanning microscopy.  

PubMed

Soluble proteins and glycogen particles are well preserved in paraffin-embedded sections prepared by in vivo cryotechnique (IVCT) and cryobiopsy followed by freeze substitution fixation. We performed confocal laser scanning microscopic analyses on the distributions of glycogen with periodic acid-Schiff (PAS) staining and serum proteins with immunostaining for mouse liver tissues. Livers of fully fed mice showed a strong fluorescence signal of PAS staining in all hepatocytes and immunofluorescence of immunoglobulin kappa light chain (Ig?) in blood vessels and bile canaliculi. However, some hepatocytes in mechanically damaged livers were PAS-negative and Ig?-immunopositive, showing extraction of glycogen particles and infiltration of serum proteins in hepatocytes. By three-dimensional (3D) reconstruction of serial optical sections, interconnecting hepatic sinusoids and bile canaliculi were detected with Ig? immunostaining between trabecular hepatocytes that were PAS stained. In PAS-stained samples under fasting conditions, interstitial structures along sinusoids were clarified in vivo by 3D reconstruction because of the lower PAS staining intensity of hepatocytes. In addition, 100-?m-thick eosin-stained slices provided 3D structural images more than 30 ?m in thickness away from tissue surfaces, showing blood vessels with flowing erythrocytes and networks of bile ducts and canaliculi. IVCT and cryobiopsy with histochemical analyses enabled us to visualize native hepatocytic glycogen and 3D structures, such as vascular networks, reflecting their living states by confocal laser scanning microscopy. PMID:20709827

Saitoh, Yurika; Terada, Nobuo; Saitoh, Sei; Ohno, Nobuhiko; Fujii, Yasuhisa; Ohno, Shinichi

2010-01-01

348

High throughput, detailed, cell-specific neuroanatomy of dendritic spines using microinjection and confocal microscopy  

PubMed Central

Morphological features such as size, shape and density of dendritic spines have been shown to reflect important synaptic functional attributes and potential for plasticity. Here we describe in detail a protocol for obtaining detailed morphometric analysis of spines using microinjection of fluorescent dyes, high resolution confocal microscopy, deconvolution and image analysis using NeuronStudio. Recent technical advancements include better preservation of tissue resulting in prolonged ability to microinject, and algorithmic improvements that compensate for the residual Z-smear inherent in all optical imaging. Confocal imaging parameters were probed systematically for the identification of both optimal resolution as well as highest efficiency. When combined, our methods yield size and density measurements comparable to serial section transmission electron microscopy in a fraction of the time. An experiment containing 3 experimental groups with 8 subjects in each can take as little as one month if optimized for speed, or approximately 4 to 5 months if the highest resolution and morphometric detail is sought. PMID:21886104

Dumitriu, Dani; Rodriguez, Alfredo; Morrison, John H.

2012-01-01

349

Confocal laser scanning microscopy as a valuable tool in Diptera larval morphology studies.  

PubMed

Larval morphology of flies is traditionally studied using light microscopy, yet in the case of fine structures compound light microscopy is limited due to problems of resolution, illumination and depth of field, not allowing for precise recognition of sclerites' edges and interactions. Using larval instars of cyclorrhaphan Diptera, we show the usefulness of confocal laser scanning microscopy (CLSM) for studying the morphological characters of immature stages by taking advantage of the autofluorescent properties of cephaloskeleton structures. We compare data obtained from killed but unprepared larvae with those from larvae prepared by clearing according to two commonly used methods, either with potassium hydroxide or with Hoyer's medium. We also evaluated the CLSM application for examining already slide-mounted larvae stored in museum collections and those freshly prepared. Our results indicate that CLSM and 3D reconstruction are excellent for visualizing small, compound structures of cylrorrhaphan larvae cephaloskeleton, if appropriate clearing techniques, i.e. the application of KOH, are used. Maximum intensity projection of confocal data sets obtained from material freshly prepared and that stored in museum collection does not differ. Because of this and the fact that KOH is commonly used as a clearing method to examine the cephaloskeleton of Diptera larvae, it is possible, and highly recommended, to use slides already prepared with this method for re-examination by CLSM. We conclude that CLSM application can be an invaluable source of data for studies of larval morphology of Cyclorrhapha by way of taxonomic diagnoses, character identification and improvement in characters homologization. PMID:25231077

Grzywacz, Andrzej; Gral, Tomasz; Szpila, Krzysztof; Hall, Martin J R

2014-11-01

350

Design and optimization of tracking in a confocal microscope  

NASA Astrophysics Data System (ADS)

The ability to image and analyze fluorescent molecules both in vitro and in vivo is of great interest in molecular biology. Tracking systems to enable such imaging continue to be developed based on a variety of approaches. Existing tracking techniques generally require complicated and expensive experimental setups or are limited in their capability. This dissertation describes a system for tracking multiple fluorescent particles in a standard confocal microscope with a piezoactuated nanopositioning stage. A position estimation algorithm, fluoroBancroft, is utilized to analytically estimate particle position from a collection of measurements taken at discrete locations around the particle. This estimate is then used in a linear quadratic Gaussian (LQG) controller to regulate the tracking error. The technique relies on a standard confocal setup, making it easier to implement than other tracking schemes. The experimental results indicated that the system can track single and multiple particles successfully in both two and three dimensions. To verify tracking and characterize tracking performance in these experiments, a CCD camera was introduced into the physical setup and synchronized to capture an image at every measurement location. In two dimensions, the overall tracking error was approximated by the standard deviation of the position estimates derived from each of the images. We find the tracking error increases as the square root of the diffusion coefficient plus an additional error that comes from position estimation error, digital-to-analog or analog-to-digital error and controller parameters mismatch. While the CCD-based estimates of the 3-D position of the particle were not accurate enough to quantify tracking performance, they did provide independent confirmation of tracking. Because the performance of the estimation depends strongly on the choice of measurement pattern, we also describe work on optimizing that pattern to minimize the variance of the estimate subject to an unbiasedness constraint The analysis takes ad- vantage of the fact that the natural logarithm of a Poisson random variable with large rate can be approximated as a random variable with a Gaussian distribution. A sufficient condition for an unbiased measurement constellation and the optimal radius of a given constellation geometry with six measurements are then derived. The results are illustrated through both numerical simulation and experiments. In addition to optimizing the measurement pattern, this dissertation also describes new results on the time-optimal control of second-order systems and an application of that theory to increase the throughput of the tracking system. Two linear affine mappings are derived to transfer the system to the normal coordinates. Based on the switching curve for a holdable equilibrium target state constructed in the normal coordinates, the switching number and switching time of the bang-bang control are numerically calculated, and a feedback time-optimal control law is designed too. The switching curves for both non-equilibrium and non-holdable equilibrium target state are also discussed.

Shen, Zhaolong

351

High-content data evaluation by means of confocal fluorescence spectroscopy  

NASA Astrophysics Data System (ADS)

With the development of fluorescence correlation spectroscopy (FCS) in the 1990s, a fundamental milestone was set in the field of highly resolved and quantitative fluorescence detection. Moreover, the increasing knowledge about the meaning of confocal fluorescence detection and its experienced handling enabled unrivalled degrees of detection sensitivity. In the end of the decade, hence the possibility of detecting single fluorescent molecules initiated a productive scientific rush for a comprehensive exploitation of fluorescence properties on the single molecule level. Meanwhile, confocal fluorescence spectroscopy has overcome its predominantly scientific meaning in basic research, and rather found wide applications even in the life science industry. However, biological assay systems relevant for industrial dedication mainly require reagent concentrations above those of classical single molecule detection. They rather lie within the "molecular fluctuation range", which means that in the temporal average a plurality of fluorescent particles rather than only one is present within the confocal detection area at a time. Thus, although individual molecules may not longer be resolved, their diffusive fluctuations are furthermore visible and contain a valuable amount of information. On the other hand FCS, a typical fluctuation evaluation technique, is restricted to the quantification of translational molecular diffusion, which in a number of cases is not sufficient to characterize the biological system of interest. Hence, a series of additional complementary fluctuation and non-fluctuation based confocal spectroscopic techniques was developed during recent years and named FCS+plus. They provide simultaneous access to a multitude of molecular properties like concentration, translational and rotational diffusion, molecular brightness, coincidence and fluorescence lifetime and thus meet the needs of both scientific research and industrial application. In the following particular aspects of molecular polarization will be shortly described and illustrated by a comparison of stationary and time-resolved anisotropy. Another valuable subject in especially industrial application of fluorescence is that of artificially interfering effects. The most prominent of these disturbances is given with the potential "auto-fluorescence" of non-labeled biological molecules. In these - frequently appearing - cases the wanted signal of fluorescently labeled material will be superimposed by artifacts, making a proper data interpretation rather difficult. However, the FCS+plus' abilities of decomposing a fluorescence signal into the molecular species' fractional contributions enables a sophisticated consideration of unwanted interferences.

Brand, L.; Schroers, A.

2005-03-01

352

In-vivo diagnosis and non-inasive monitoring of Imiquimod 5% cream for non-melanoma skin cancer using confocal laser scanning microscopy  

NASA Astrophysics Data System (ADS)

Basal cell carcinoma (BCC) is the most common cutaneous malignancy with increasing incidence rates worldwide. A number of established treatments are available, including surgical excision. The emergence of new non-invasive treatment modalities has prompted the development of non-invasive optical devices for therapeutic monitoring and evaluating treatment efficacy. This study was aimed to evaluate the clinical applicability of a fluorescence confocal laser scanning microscope (CFLSM) for non-invasive therapeutic monitoring of basal cell carcinoma treated with Imiquimod (Aldara) as topical immune-response modifier. Eight participants with a diagnosis of basal cell carcinoma (BCC) were enrolled in this investigation. Sequential evaluation during treatment with Imiquimod showed progressive normalization of the confocal histomorphologic parameters in correlation with normal skin. Confocal laser scanning microscopy was able to identify characteristic features of BCC and allowed the visualization of therapeutic effects over time. Thus our results indicate the clinical applicability of CFLSM imaging to evaluate treatment efficacy in vivo and non-invasively.

Dietterle, S.; Lademann, J.; Rwert-Huber, H.-J.; Stockfleth, E.; Antoniou, C.; Sterry, W.; Astner, S.

2008-10-01

353

Mosaicing of Confocal Microscopic In Vivo Soft Tissue Video Sequences  

Microsoft Academic Search

Fibered confocal microscopy allows in vivo and in situ imag- ing with cellular resolution. The potentiality of this imaging modality is extended in this work by using video mosaicing techniques. Two novelties are introduced. A robust estimator based on statistics for Riemannian manifolds is developed to find a globally consistent mapping of the input frames to a common coordinate system.

Tom Vercauteren; Aymeric Perchant; Xavier Pennec; Nicholas Ayache

2005-01-01

354

Analysis of confocal microscopy under ultrashort light-pulse illumination  

SciTech Connect

The resolution of confocal laser scanning microscopes is analyzed if they are used in measurements that are to combine high spatial and high temporal resoltuion. A generalized Fourier-optical treatment is developed in which the system characteristics contain all necessary information regarding the optical arrangement and the illuminating light pulses. Coherent and incoherent imaging are considered in detail. 10 refs., 8 figs.

Kempe, M.; Rudolph, W. (Univ. of New Mexico, Albuquerque (United States))

1993-02-01

355

page 1 of 6Confocal Raman Microscopy ...SEEtheFuture  

E-print Network

Marvin Minsky. He was obsessed with resolving the mystery of the human nerve system anatomy which aids confocal microscope [1]. Optical design principles Prof. Minsky hypothesized that all the scattered light series of optical sections from bulk specimens. With this optical design, Prof. Minsky was able

Lombardi, John R.

356

Laser excited confocal microscope fluorescence scanner and method  

DOEpatents

A fluorescent scanner for scanning the fluorescence from a fluorescence labeled separated sample on a sample carrier including a confocal microscope for illuminating a predetermined volume of the sample carrier and/or receiving and processing fluorescence emissions from said volume to provide a display of the separated sample.

Mathies, Richard A. (Contra Costa, CA); Peck, Konan (Contra Costa, CA)

1992-01-01

357

Electrostatically driven micromirrors for a miniaturized confocal laser scanning microscope  

Microsoft Academic Search

A compact two-mirror microscanner has been fabricated to build the central part of a miniaturized confocal laser scanning microscope. This microscope shall be mounted at the tip of an endoscope to provide high resolution imaging for medical diagnostics. In order to achieve a resolution of 500 X 500 image elements large scan angles and also large mirror dimensions have to

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

1999-01-01

358

CONFOCAL MICROSCOPY SYSTEM PERFORMANCE: SPECTROSCOPY AND FOUNDATIONS FOR QUANTITATION  

EPA Science Inventory

The confocal laser-scanning microscope (CLSM) has enormous potential in many biological fields. The reliability of the CLSM to obtain specific measurements and quantify fluorescence data is dependent on using a correctly aligned machine that contains a stable laser power. For man...

359

CONFOCAL MICROSCOPY SYSTEM PERFORMANCE: FOUNDATIONS FOR CALIBRATION, QUANTITATION AND SPECTROSCOPY  

EPA Science Inventory

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

360

CONFOCAL MICROSCOPY SYSTEM PERFORMANCE: FOUNDATIONS FOR MEASUREMENTS, QUANTITATION AND SPECTROSCOPY  

EPA Science Inventory

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

361

Laser excited confocal microscope fluorescence scanner and method  

DOEpatents

A fluorescent scanner is designed for scanning the fluorescence from a fluorescence labeled separated sample on a sample carrier. The scanner includes a confocal microscope for illuminating a predetermined volume of the sample carrier and/or receiving and processing fluorescence emissions from the volume to provide a display of the separated sample. 8 figs.

Mathies, R.A.; Peck, K.

1992-02-25

362

Identification of Nodal Tissue in the Living Heart Using Rapid Scanning Fiber-optics Confocal Microscopy and Extracellular Fluorophores  

PubMed Central

Background Risks associated with pediatric reconstructive heart surgery include injury of the sinoatrial node (SAN) and atrioventricular node (AVN), requiring cardiac rhythm management using implantable pacemakers. These injuries are result of difficulties in identifying nodal tissues intraoperatively. Here, we describe an approach based on confocal microscopy and extracellular fluorophores to quantify tissue microstructure and identify nodal tissue. Methods and Results Using conventional three-dimensional confocal microscopy we investigated the microstructural arrangement of SAN, AVN, and atrial working myocardium (AWM) in fixed rat heart. AWM exhibited a regular striated arrangement of the extracellular space. In contrast, SAN and AVN had an irregular, reticulated arrangement. AWM, SAN and AVN tissue were beneath a thin surface layer of tissue that did not obstruct confocal microscopic imaging. Subsequently, we imaged tissues in living rat hearts with real-time fiber-optics confocal microscopy (FCM). FCM images resembled images acquired with conventional confocal microscopy. We investigated spatial regularity of tissue microstructure from Fourier analysis and 2nd order image moments. Fourier analysis of FCM images showed that the spatial regularity of AWM was greater than that of nodal tissues (37.55.0% versus 24.33.9% for SAN and 23.83.7% for AVN, P<0.05). Similar differences of spatial regularities were revealed from 2nd order image moments (50.07.3% for AWM versus 29.36.7% for SAN and 27.35.5% for AVN; P<0.05). Conclusions The study demonstrates feasibility of identifying nodal tissue in living heart using extracellular fluorophores and FCM. Application of the approach in pediatric reconstructive heart surgery may reduce risks of injuring nodal tissues. PMID:23811748

Huang, Chao; Kaza, Aditya K.; Hitchcock, Robert W.; Sachse, Frank B.

2014-01-01

363

Multi-kernel deconvolution applied to confocal fluorescence microscopy with engineered point spread function  

E-print Network

of an object emit light in the same manner. One had to wait the invention of the confocal microscope by Marvin Minski [2] to get a first breakthrough. In a confocal microscope, the specimen is not anymore uniformly

Paris-Sud XI, Universit de

364

Analysis of a marine phototrophic biofilm by confocal laser scanning microscopy using the new image quantification software PHLIP  

PubMed Central

Background Confocal laser scanning microscopy (CLSM) is the method of choice to study interfacial biofilms and acquires time-resolved three-dimensional data of the biofilm structure. CLSM can be used in a multi-channel modus where the different channels map individual biofilm components. This communication presents a novel image quantification tool, PHLIP, for the quantitative analysis of large amounts of multichannel CLSM data in an automated way. PHLIP can be freely downloaded from Results PHLIP is an open source public license Matlab toolbox that includes functions for CLSM imaging data handling and ten image analysis operations describing various aspects of biofilm morphology. The use of PHLIP is here demonstrated by a study of the development of a natural marine phototrophic biofilm. It is shown how the examination of the individual biofilm components using the multi-channel capability of PHLIP allowed the description of the dynamic spatial and temporal separation of diatoms, bacteria and organic and inorganic matter during the shift from a bacteria-dominated to a diatom-dominated phototrophic biofilm. Reflection images and weight measurements complementing the PHLIP analyses suggest that a large part of the biofilm mass consisted of inorganic mineral material. Conclusion The presented case study reveals new insight into the temporal development of a phototrophic biofilm where multi-channel imaging allowed to parallel monitor the dynamics of the individual biofilm components over time. This application of PHLIP presents the power of biofilm image analysis by multi-channel CLSM software and demonstrates the importance of PHLIP for the scientific community as a flexible and extendable image analysis platform for automated image processing. PMID:16412253

Mueller, Lukas N; de Brouwer, Jody FC; Almeida, Jonas S; Stal, Lucas J; Xavier, Joo B

2006-01-01

365

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. In particular, profile inversion allows improved velocity and magnetic field gradients to be determined independent of multiple line analysis using different energy levels and ions. The confocal interferometer's unique properties allow a simultaneous increase in both etendue and spectral power. The higher throughput for the interferometer provides significant decrease in the aperture, which is important in spaceflight considerations. We have constructed and tested two confocal interferometers. A slow-response thermal-controlled interferometer provides a stable system for laboratory investigation, while a piezoelectric interferometer provides a rapid response for solar observations. In this paper we provide design parameters, show construction details, and report on the laboratory test for these interferometers. The field of view versus aperture for confocal interferometers is compared with other types of spectral imaging filters. We propose a multiple etalon system for observing with these units using existing planar interferometers as pre-filters. The radiometry for these tests established that high spectral resolution profiles can be obtained with imaging confocal interferometers. These sub-picometer spectral data of the photosphere in both the visible and near-infrared can provide important height variation information. However, at the diffraction-limited spatial resolution of the telescope, the spectral data is photon starved due to the decreased spectral passband.

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

2007-01-01

366

Detection of plant injury from application of non-selective herbicide by measurement of chlorophyll reflectance and fluorescene  

Technology Transfer Automated Retrieval System (TEKTRAN)

Subtle changes in canopy reflectance could present useful information to detect the onset of crop stress. This study was conducted in a greenhouse to evaluate a portable spectroradiometer and a portable chlorophyll fluorometer for the detection of crop injury caused by glyphosate spray. In this stud...

367

APPLICATION OF PARTIAL LEAST SQUARES REGRESSION TO NEAR-INFRARED REFLECTANCE SPECTROSCOPIC DETERMINATION OF SHIVE CONTENT IN FLAX  

Technology Transfer Automated Retrieval System (TEKTRAN)

Shive, the non-fiberous core portion of the stem, in flax fiber after retting is related with fiber quality. The objective of this study is to develop a standard calibration model for determining shive content in retted flax by using near infrared reflectance spectroscopy. Calibration samples were p...

368

Evaluation of optical reflectance techniques for imaging of alveolar structure  

NASA Astrophysics Data System (ADS)

Three-dimensional (3-D) visualization of the fine structures within the lung parenchyma could advance our understanding of alveolar physiology and pathophysiology. Current knowledge has been primarily based on histology, but it is a destructive two-dimensional (2-D) technique that is limited by tissue processing artifacts. Micro-CT provides high-resolution three-dimensional (3-D) imaging within a limited sample size, but is not applicable to intact lungs from larger animals or humans. Optical reflectance techniques offer the promise to visualize alveolar regions of the large animal or human lung with sub-cellular resolution in three dimensions. Here, we present the capabilities of three optical reflectance techniques, namely optical frequency domain imaging, spectrally encoded confocal microscopy, and full field optical coherence microscopy, to visualize both gross architecture as well as cellular detail in fixed, phosphate buffered saline-immersed rat lung tissue. Images from all techniques were correlated to each other and then to corresponding histology. Spatial and temporal resolution, imaging depth, and suitability for in vivo probe development were compared to highlight the merits and limitations of each technology for studying respiratory physiology at the alveolar level.

Unglert, Carolin I.; Namati, Eman; Warger, William C.; Liu, Linbo; Yoo, Hongki; Kang, DongKyun; Bouma, Brett E.; Tearney, Guillermo J.

2012-07-01

369

Design of 220 GHz electronically scanned reflectarrays for confocal imaging systems  

NASA Astrophysics Data System (ADS)

The authors analyze properties of a 220 GHz imaging system that uses a scanned reflectarray to perform electronic beam scanning of a confocal imager for applications including imaging meter-sized fields of view at 50 m standoff. Designs incorporating reflectarrays with confocal imagers have not been examined previously at these frequencies. We examine tradeoffs between array size, overall system size, and number of achievable image pixels resulting in a realistic architecture capable of meeting the needs of our application. Impacts to imaging performance are assessed through encircled energy calculations, beam pointing accuracy, and examining the number and intensity of quantization lobes that appear over the scan ranges of interest. Over the desired scan range, arrays with 1 and 2-bit phase quantization showed similar array main beam energy efficiencies. Two-bit phase quantization is advantageous in terms of pointing angle error, resulting in errors of at most 15% of the diffraction-limited beam size. However, both phase quantization cases considered resulted in spurious returns over the scan range of interest and other array layouts should be examined to eliminate potential imaging artifacts.

Hedden, Abigail S.; Dietlein, Charles R.; Wikner, David A.

2012-09-01

370

Applications of multidirectional asymmetrical microlens-array light-control films on reflective liquid-crystal displays for image quality enhancement.  

PubMed

The multidirectional asymmetrical microlens-array light-control film (MAMA-LCF) is developed for enhancing the image brightness and contrast ratio of various reflective liquid-crystal displays. By use of index-matching material, the interface reflection is greatly reduced. Through optimized designs, the surface-scattering effect is also suppressed; thus the contrast ratio is much enhanced. From experimental results, the MAMA-LCF leads to a approximately 1.5 x gain in brightness over the MgO standard white and a 15:1 contrast ratio for the reflective color super-twist nematic liquid-crystal display, 2.8 x MgO and a 23:1 contrast ratio for the polymer-dispersed liquid-crystal, and 2.8 x MgO and a 13:1 contrast ratio for the cholesteric liquid-crystal display. Potential applications of this low-cost plastic thin film for reflective liquid-crystal displays are foreseeable. PMID:15218605

Huang, Yi-Pai; Shieh, Han-Ping David; Wu, Shin-Tson

2004-06-20

371

Application of characteristic vector analysis to the spectral energy distribution of daylight and the spectral reflectance of american soils.  

PubMed

Measurements have been made of the spectral energy distribution of daylight (sunlight plus skylight) and skylight in the near-uv and visible region of the spectrum as a function of solar altitude for various atmospheric conditions as measured on planes of different orientation. A characteristic vector analysis was made of the digitized data. From these data, a variance-covariance matrix was computed for the daylight energy data and another for the skylight energy data. The four vectors were capable of accounting for 98.2% of the trace of the variance-covariance matrix for daylight and 99.4% for the skylight data. Spectral reflectances extending from 320 nm to 1000 nm have been obtained for 160 soil samples collected from thirty-six states. Measurements were made of both wet and dry samples, which vary widely in color and reflectance. An examination of the 160 sets of curves indicates that they can be classified into three general types with respect to their curve shapes. A characteristic vector analysis was made of the spectral reflectance data; it showed that by linear combinations of four vectors and the mean curve, each set of data could be reconstituted to a high degree of accuracy (99.9% of the trace). Empirical regression equations have been derived that relate spectral reflectance data at thirty-five wavelengths spaced at 20-nm increments to measurements made at only five specially selected wavelengths. To the extent that soils may be identified by their reflectance characteristics, this abridged technique seems to have sufficient accuracy for the 160 samples that have been measured. PMID:20111459

Condit, H R

1972-01-01

372

Whole-body ring-shaped confocal photoacoustic computed tomography of  

E-print Network

Whole-body ring-shaped confocal photoacoustic computed tomography of small animals in vivo Jun Xia;Whole-body ring-shaped confocal photoacoustic computed tomography of small animals in vivo Jun Xia a novel small-animal whole-body imaging system called ring-shaped confocal photoacoustic computed

Wang, Lihong

373

Modeling Light Reflection for Computer Color Vision  

Microsoft Academic Search

In computer vision applications, analysis of shading information requires a proper model of light reflection from object surfaces. To overcome the shortcoming of the most often used model and to extend the reflection model for computer color vision, an examination is made of the light reflection problem using the bidirectional spectral-reflectance distribution function (BSRDF) to specify both incident- and reflected-beam

Hsien-che Lee; Edwin J. Breneman; Carl P. Schulte

1990-01-01

374

Confocal Raman microscopy for investigation of the level of differentiation in living neuroblastoma tumor cells  

NASA Astrophysics Data System (ADS)

The investigation of living cells at physiological conditions requires very sensitive, sophisticated, non invasive methods. In this study, Raman spectral imaging is used to identify different biomolecules inside of cells. Raman spectroscopy, a chemically and structurally sensitive measuring technique, is combined with high resolution confocal microscopy. In Raman spectral imaging mode, a complete Raman spectrum is recorded at every confocal image point, giving insight into the chemical composition of each sample compartment. Neuroblastoma is the most common solid extra-cranial tumor in children. One of the unique features of neuroblastoma cells is their ability to differentiate spontaneously, eventually leading to complete remission. Since differentiation agents are currently used in the clinic for neuroblastoma therapy, there is a special need to develop non-invasive and sensitive new methods to monitor neuroblastoma cell differentiation. Neuroblastoma cells at different degrees of differentiation were analysed with the confocal Raman microscope alpha300 R (WITec GmbH, Germany), using a frequency doubled Nd:YAG laser at 532 nm and 10 mW for excitation. Integration time per spectrum was 80-100 ms. A lateral resolution in submicrometer range was achieved by using a 60x water immersion lens with a numerical aperture of 1,0. Raman images of cells were generated from these sets of data by either integrating over specific Raman bands, by basis analysis using reference spectra or by cluster analysis. The automated evaluation of all spectra results in spectral unmixed images providing insight into the chemical composition of the sample. With these procedures, different cell organelles, cytosol, membranes could be distinguished. Since neuroblastoma cells at high degree of differentiation overproduce noradrenaline, an attempt was made to trace the presence of this neurotransmitter as a marker for differentiation. The results of this work may have applications in the monitoring of molecular changes and distribution of biomolecules and in particular of low molecular weight markers as they occur during the differentiation of neuroblastoma cells.

Scalfi-Happ, Claudia; Jauss, Andrea; Hollricher, Olaf; Fulda, Simone; Hauser, Carmen; Steiner, Rudolf; Rck, Angelika

2007-07-01

375

Optimal detection pinhole for lowering speckle noise while maintaining adequate optical sectioning in confocal reflectance microscopes  

PubMed Central

Abstract. Coherent speckle influences the resulting image when narrow spectral line-width and single spatial mode illumination are used, though these are the same light-source properties that provide the best radiance-to-cost ratio. However, a suitable size of the detection pinhole can be chosen to maintain adequate optical sectioning while making the probability density of the speckle noise more normal and reducing its effect. The result is a qualitatively better image with improved contrast, which is easier to read. With theoretical statistics and experimental results, we show that the detection pinhole size is a fundamental parameter for designing imaging systems for use in turbid media. PMID:23224184

Glazowski, Christopher; Rajadhyaksha, Milind

2012-01-01

376

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

E-print Network

damage to the surrounding normal skin is guided by the exami- nation of frozen histology of each excision during Mohs surgery. The preparation of frozen histology is slow, requiring 20 to 45 min per excision, with minimal need for frozen histology. Soaking the excisions in acetic acid rapidly brightens nuclei

Sridhar, Srinivas

377

Reflectance and Fluorescence Confocal Microscope for Imaging of the Mouse Colon  

E-print Network

scan rates from 2.5 kHz to 8.75 kHz. A Keplerian telescope system with 75 mm effective focal length (EFL) (49-389, Edmund Optics, Barrington, NJ) images the illumination source onto the galvanometer scanner (6220HM40B, Cambridge Technologies... Instruments, Austin, TX) controlled by LabVIEW software. Another Keplerian telescope system with 75 mm and 100 mm EFL (49-389, 49- 390, Edmund Optics, Barrington, NJ) expands the beam to fill the back aperture of the 40x 0.8NA water immersion microscope...

Saldua, Meagan Alyssa

2012-02-14

378

Confocal Microscopy of Jammed Matter: From Elasticity to Granular Thermodynamics  

NASA Astrophysics Data System (ADS)

Packings of particles are ubiquitous in nature and are of interest not only to the scientific community but also to the food, pharmaceutical, and oil industries. In this thesis we use confocal microscopy to investigate packing geometry and stress transmission in 3D jammed particulate systems. By introducing weak depletion attraction we probe the accessible phase-space and demonstrate that a microscopic approach to jammed matter gives validity to statistical mechanics framework, which is intriguing because our particles are not thermally activated. We show that the fluctuations of the local packing parameters can be successfully captured by the recently proposed 'granocentric' model, which generates packing statistics according to simple stochastic processes. This model enables us to calculate packing entropy and granular temperature, the so-called 'compactivity', therefore, providing a basis for a statistical mechanics of granular matter. At a jamming transition point at which there are formed just enough number of contacts to guarantee the mechanical stability, theoretical arguments suggest a singularity which gives rise to the surprising scaling behavior of the elastic moduli and the microstructure, as observed in numerical simulations. Since the contact network in 3D is typically hidden from view, experimental test of the scaling law between the coordination number and the applied pressure is lacking in the literature. Our data show corrections to the linear scaling of the pressure with density which takes into account the creation of contacts. Numerical studies of vibrational spectra, in turn, reveal sudden features such as excess of low frequency modes, dependence of mode localization and structure on the pressure. Chapter four describes the first calculation of vibrational density of states from the experimental 3D data and is in qualitative agreement with the analogous computer simulations. We study the configurational role of the pressure and demonstrate that low frequency modes become progressively localized as the packing density is increased. Another application of our oil-in-water emulsions serves to mimic cell adhesion in biological tissues. By analyzing the microstructure in 3D we find that a threshold compression force is necessary to overcome electrostatic repulsion and surface elasticity and establish protein-mediated adhesion.

Jorjadze, Ivane

379

Parameterization of aerosol and cirrus cloud effects on reflected sunlight spectra measured from space: application of the equivalence theorem.  

PubMed

An original methodology to account for aerosol and cirrus cloud contributions to reflected sunlight is described. This method can be applied to the problem of retrieving greenhouse gases from satellite-observed data and is based on the equivalence theorem with further parameterization of the photon path-length probability density function (PPDF). Monte Carlo simulation was used to validate this parameterization for a vertically nonhomogeneous atmosphere including an aerosol layer and cirrus clouds. Initial approximation suggests that the PPDF depends on four parameters that can be interpreted as the effective cloud height, cloud relative reflectance, and two additional factors to account for photon path-length distribution under the cloud. We demonstrate that these parameters can be efficiently retrieved from the nadir radiance measured in the oxygen A-band and from the H(2)O-saturated area of the CO(2) 2.0 microm spectral band. PMID:17429457

Bril, Andrey; Oshchepkov, Sergey; Yokota, Tatsuya; Inoue, Gen

2007-05-01

380

The size control of silver nanocrystals with different polyols and its application to low-reflection coating materials  

NASA Astrophysics Data System (ADS)

The size of silver nanocrystals in polyol synthesis can be simply controlled by tuning the viscosity of the reaction medium such as ethylene glycol, 1,2-propanediol, 1,4-butanediol and 1,5-pentanediol. We found that a higher viscose medium (1,5-pentanediol) led to monodispersed smaller particles thanks to the slow addition of silver atoms into the nuclei. Size-controlled silver nanocrystals of 30 nm were obtained in a viscosity controlled medium of 1,5-pentanediol to synthesize a low refractive index filler by coating with silica and subsequent etching of the silver core. The coated low-reflection layer from the hollow silica nanoparticles on polyethylene terephthalate (PET) film can greatly reduce the reflection of the PET film from 10% to 2% over the entire visible region.

Park, Keum Hwan; Im, Sang Hyuk; Park, O. Ok

2011-01-01

381

Three-Dimensional Visualization of Interfacial Phenomena Using Confocal Microscopy  

NASA Astrophysics Data System (ADS)

Surfactants play an integral role in numerous functions ranging from stabilizing the emulsion in a favorite salad dressing to organizing the cellular components that make life possible. We are interested in lung surfactant, which is a mixture of lipids and proteins essential for normal respiration because it modulates the surface tension of the air-liquid interface of the thin fluid lining in the lungs. Through this surface tension modulation, lung surfactant ensures effortless lung expansion and prevents lung collapse during exhalation, thereby effecting proper oxygenation of the bloodstream. The function of lung surfactant, as well as numerous interfacial lipid systems, is not solely dictated by the behavior of materials confined to the two-dimensional interface. Rather, the distributions of materials in the liquid subphase also greatly influence the performance of interfacial films of lung surfactant. Therefore, to better understand the behavior of lung surfactant and other interfacial lipid systems, we require a three-dimensional characterization technique. In this dissertation, we have developed a novel confocal microscopy methodology for investigating the interfacial phenomena of surfactants at the air-liquid interface of a Langmuir trough. Confocal microscopy provides the excellent combination of in situ, fast, three-dimensional visualization of multiple components of the lung surfactant system that other characterization techniques lack. We detail the solutions to the numerous challenges encountered when imaging a dynamic air-liquid interface with a high-resolution technique like confocal microscopy. We then use confocal microscopy to elucidate the distinct mechanisms by which a polyelectrolyte (chitosan) and nonadsorbing polymer (polyethylene glycol) restore the function of lung surfactant under inhibitory conditions mimicking the effects of lung trauma. Beyond this physiological model, we also investigate several one- and two-component interfacial films of the various lipid constituents of lung surfactant. Confocal microscopy allows us to use a water-soluble, cationic fluorophore that partitions into the disordered phases of lipid monolayers. By exploiting the properties of this water-soluble fluorophore, we investigate both the phase behavior and electrostatics of the interfacial lipid systems. Overall, we believe the work presented in this dissertation provides the building blocks for establishing confocal microscopy as a ubiquitous characterization technique in the interfacial and surface sciences.

Shieh, Ian C.

382

Application of Remote Spectral Reflectance Measurements to Lunar Geology Classification and Determination of Titanium Content of Lunar Soils  

Microsoft Academic Search

Plots of reflectance slope between 0.402 and 0.564\\/m versus the intensity ratio between 0.564 and 0.948\\/m are used to quantitatively define the mare, mare crater, upland, and bright upland crater spectral types previously presented by McCord et al. (1972a). An additional spectral type, dark mantling material, has also been found. Quantification of lunar spectral types allows direct comparison of the

Michael P. Charette; Thomas B. McCord; Carle Pieters; John B. Adams

1974-01-01

383

Solid sulfur in vacuum: Sublimation effects on surface microtexture, color and spectral reflectance, and applications to planetary surfaces  

NASA Technical Reports Server (NTRS)

A form of sulfur that is white at room temperature and very fluffy in texture has been found in laboratory experiments on the effects of vacuum sublimation (evaporation) on solid sulfur. This work is an outgrowth of proton sputtering experiments on sulfur directed toward understanding Jovian magnetospheric effects on the surface of Io. Fluffy white sulfur is formed on the surface of solid yellow, tan, or brown sulfur melt freezes in vacuum by differential (fractional) evaporation of two or more sulfur molecular species present in the original sulfur; S(8) ring sulfur is thought to be the dominant sublimination phase lost to the vacuum sink, and polymeric chain sulfur S(u) the dominant residual phase that remains in place, forming the residual fluffy surface layer. The reflectance spectrum of the original sulfur surface is greaty modified by formation of the fluffy layer: the blue absorption band-edge and shoulder move 0.05 to 0.06 microns toward shorter wavelengths resulting in a permanent increase in reflectivity near 0.42 to 0.46 microns; the UV reflectivity below 0.40 microns is reduced. This form of sulfur should exist in large quantity on the surface of Io, especially in hotspot regions if there is solid free sulfur there that has solidified from a melt. Its color and spectra will indicate relative crystallization age on a scale of days to months and/or surface temperature distribution history.

Nash, D. B.

1987-01-01

384

Confocal Light Absorption and Scattering Spectroscopic (CLASS) imaging: From cancer detection to sub-cellular function  

NASA Astrophysics Data System (ADS)

Light scattering spectroscopy (LSS), an optical technique that relates the spectroscopic properties of light elastically scattered by small particles to their size, refractive index and shape, has been recently successfully employed for sensing morphological and biochemical properties of epithelial tissues and cells in vivo. LSS does not require exogenous markers, is non-invasive, and, due to its multispectral nature, can sense biological structures well beyond the diffraction limit. All that makes LSS be a very good candidate to be used both in clinical medicine for in vivo detection of disease and in cell biology to monitor cell function on the organelle scale. Recently we developed two LSS-based imaging modalities: clinical Polarized LSS (PLSS) Endoscopic Technique for locating early pre-cancerous changes in GI tract and Confocal Light Absorption and Scattering Spectroscopic (CLASS) Microscopy for studying cells in vivo without exogenous markers. One important application of the clinical PLSS endoscopic instrument, a noncontact scanning imaging device compatible with the standard clinical endoscopes and capable of detecting dysplastic changes, is to serve as a guide for biopsy in Barrett's esophagus (BE). The instrument detects parallel and perpendicular components of the polarized light, backscattered from epithelial tissues, and determines characteristics of epithelial nuclei from the residual spectra. It also can find tissue oxygenation, hemoglobin content and other properties from the diffuse light component. By rapidly scanning esophagus the PLSS endoscopic instrument makes sure the entire BE portion is scanned and examined for the presence of dysplasia. CLASS microscopy, on the other hand, combines principles of light scattering spectroscopy (LSS) with confocal microscopy. Its main purpose is to image cells on organelle scale in vivo without the use of exogenous labels which may affect the cell function. The confocal geometry selects specific region and images are obtained by scanning the confocal volume across the sample. The new beam scanning CLASS microscope is a significant improvement over the previous proof-of-principle device. With this new device we have already performed experiments to monitor morphological changes in cells during apoptosis, differentiated fetal from maternal nucleated red blood cells, and detected plasmon scattering spectra of single gold nanorod.

Qiu, Le

385

CellSeT: Novel Software to Extract and Analyze Structured Networks of Plant Cells from Confocal Images[W  

PubMed Central

It is increasingly important in life sciences that many cell-scale and tissue-scale measurements are quantified from confocal microscope images. However, extracting and analyzing large-scale confocal image data sets represents a major bottleneck for researchers. To aid this process, CellSeT software has been developed, which utilizes tissue-scale structure to help segment individual cells. We provide examples of how the CellSeT software can be used to quantify fluorescence of hormone-responsive nuclear reporters, determine membrane protein polarity, extract cell and tissue geometry for use in later modeling, and take many additional biologically relevant measures using an extensible plug-in toolset. Application of CellSeT promises to remove subjectivity from the resulting data sets and facilitate higher-throughput, quantitative approaches to plant cell research. PMID:22474181

Pound, Michael P.; French, Andrew P.; Wells, Darren M.; Bennett, Malcolm J.; Pridmore, Tony P.

2012-01-01

386

3D imaging of cement-based materials at submicron resolution by combining laser scanning confocal microscopy with serial sectioning.  

PubMed

In this paper, we present a new method to reconstruct large volumes of nontransparent porous materials at submicron resolution. The proposed method combines fluorescence laser scanning confocal microscopy with serial sectioning to produce a series of overlapping confocal z-stacks, which are then aligned and stitched based on phase correlation. The method can be extended in the XY plane to further increase the overall image volume. Resolution of the reconstructed image volume does not degrade with increase in sample size. We have used the method to image cementitious materials, hardened cement paste and concrete and the results obtained show that the method is reliable. Possible applications of the method such as three-dimensional characterization of the pores and microcracks in hardened concrete, three-dimensional particle shape characterization of cementitious materials and three-dimensional characterization of other porous materials such as rocks and bioceramics are discussed. PMID:25651933

Yio, M H N; Mac, M J; Wong, H S; Buenfeld, N R

2015-05-01

387

Confocal polarimeter for the living human retina  

NASA Astrophysics Data System (ADS)

There is strong evidence [1] that the living human retina has polarization signatures that could be linked to the presence of Glaucoma, an ocular disease that is the second cause of blindness in the western world. In a polarization sensitive ophthalmoscope [2], the amount of light that can be used is limited for the safety of the subject, and the return is typically a small fraction of the light used for illumination, of the order of 10-6. Furthermore, the acquisition rates have to be sufficiently fast to avoid eye-movement artifacts. The light-budget available to produce a polarization image with a scanning laser ophthalmoscope is typically in the order of 10 nW [3], and pixel acquisition sampling rates are of several MHz. We are currently developing an imaging instrument for vision research and clinical vision applications and aim to introduce it to the medical and clinical environment using objective methods of image quality assessment. In this presentation we talk about the stringent imaging requirements and show an optimized design of our instrument [4].

Lara, D.; Paterson, C.

2010-06-01

388

Laser differential confocal ultra-long focal length measurement.  

PubMed

A new laser differential confocal focal-length measurement method is proposed for the measurement of an ultra-long focal-length. The approach proposed uses the property of an axial intensity curve that the absolute zero precisely corresponds to the focus of the objective in a differential confocal focusing system (DCFS) to measure the variation in position of DCFS focus with and without a measured ultra-long focal-length lens (UFL), uses the distance between the two focuses to obtain the UFL focal-length, and thereby achieving the precise measurement of ultra-long focal-length. The method has a high focusing precision, a strong anti-interference capability and a short measurement light-path. The theoretical analyses and preliminary experimental results indicate that the relative measurement error is about 0.01% when the method is used for the measurement of back-focus-distance (BFD). PMID:19997229

Zhao, Weiqian; Sun, Ruoduan; Qiu, Lirong; Sha, Dingguo

2009-10-26

389

Automated spherical aberration correction in scanning confocal microscopy.  

PubMed

Mismatch between the refractive indexes of immersion media and glass coverslips introduces spherical aberrations in microscopes especially for high numerical aperture objectives. This contribution demonstrates an automated adjustment of the coverslip correction collar in scanning confocal microscopy to compensate for spherical aberrations due to coverslip thickness mismatch. With a motorized coverslip correction collar, the adjustment procedure consists of xz image scans, image processing, correction quality evaluation, the mismatch estimation, and eventually the optimal adjustment of the correction collar. For fast correction with less photodamage, coarse-fine Gaussian fitting algorithms are proposed and evaluated with various specimen for their estimation accuracy. The benefits of the proposed automated correction are demonstrated for various coverslips with biological specimens, showing the optimized resolution of the confocal microscope. PMID:25554300

Yoo, H W; van Royen, M E; van Cappellen, W A; Houtsmuller, A B; Verhaegen, M; Schitter, G

2014-12-01

390

Anabaena cell ageing monitored with confocal fluorescence spectroscopy.  

PubMed

Cyanobacteria use a sophisticated system of pigments to collect light energy across the visible spectrum for photosynthesis. The pigments are assembled in structures called phycobilisomes, composed of phycoerythrocyanin, phycocyanin and allophycocyanin, which absorb energy and transfer it to chlorophyll in photosystem II reaction centres. All of the components of this system are fluorescent, allowing sensitive measurements of energy transfer using single cell confocal fluorescence microscopy. The native pigments can be interrogated without the use of reporters. Here, we use confocal fluorescence microscopy to monitor changes in the efficiency of energy transfer as single cells age, between the time they are born at cell division until they are ready to divide again. Alteration of fluorescence was demonstrated to change with the age of the cyanobacterial cell. PMID:25378560

Ke, Shan; Bindokas, Vytas; Haselkorn, Robert

2015-01-01

391

Towards Optical Biopsies with an Integrated Fibered Confocal Fluorescence Microscope  

Microsoft Academic Search

This paper presents an integrated endoscope-compatible Fibered Confocal Fluorescence Microscope (FCFM) for medical imaging, the F- 400. In situ high resolution images can be obtained thanks to a set of flexible miniaturized optical probes of 0.5 to 1.5 mm diameter that can be inserted through the working channel of an endoscope. We briefly present in this paper the FCFM system,

Georges Le Goualher; Aymeric Perchant; Magalie Genet; Charlotte Cav; Bertrand Viellerobe; Frederic Berier; Benjamin Abrat; Nicholas Ayache

2004-01-01

392

Rapid identification of Candida species by confocal Raman microspectroscopy  

Microsoft Academic Search

Candida species are important nosocomial pathogens associated with high\\u000a mortality rates. Rapid detection and identification of Candida species can\\u000a guide a clinician at an early stage to prescribe antifungal drugs or to\\u000a adjust empirical therapy when resistant species are isolated. Confocal\\u000a Raman microspectroscopy is highly suitable for the rapid identification of\\u000a Candida species, since Raman spectra can be directly obtained

K. Maquelin; L.-P. Choo-Smith; H. P. Endtz; H. A. Bruining; G. J. Puppels

2002-01-01

393

Confocal microscopy study of colloidal sedimentation and crystallization  

E-print Network

; (4) the replacement of ammonia with dodecylamine in St?ber synthesis; and (5) the use of an amine functionalized silane to bind poly(isobutylene) to the surface of silica particles. New methods that were developed include: (1) a Monte Carlo... with the confocal microscope. Recently, two-micron silica particles have been sterically stabilized in toluene with a grafted layer of poly(isobutylene), and these particles do not appear to exhibit electrostatic repulsion. This success, combined...

Beckham, Richard Edward

2009-05-15

394

Confocal epifluorescence detection for microspheres delivered on disposable microfluidic chip  

Microsoft Academic Search

The laser induced fluorescence (LIF) detection system for 5-um microspheres delivered on microfluidic chip is presented employing confocal optical scheme. The parameters of the optical system are specifically optimized for single microsphere detection. With the excitation laser spot size of 4.6 um and optical sectioning power of 27 um, the lowest concentration detection limit is 0.45 nmol\\/L, corresponding to only

Honghua Hu; Xiyun Hou; Guoguang Yang

2006-01-01

395

GFP fluorescence imaging with laser confocal scanning microscope  

NASA Astrophysics Data System (ADS)

With gene marking technique, green fluorescent protein (GFP) and nodule bacteria gene has been linked together to form a single fusion gene expression vector. Then the vector is transferred into the nodule bacteria and the astragalus sinicus is invaded by the vector. With laser confocal scanning microscope, some important morphological information in plant nitrogen fixation research about the invading of nodule bacteria and the formation process of root nodule has been obtained through the 3D imaging of GFP reporting fluorescence.

Yu, Yanhua; Xing, Da; Shi, Qiaojuan; Zhou, Junchu

1999-09-01

396

Quantitative analysis of angiogenesis using confocal laser scanning microscopy  

Microsoft Academic Search

Angiogenesis is essential for tumor growth and metastasis. Angiogenesis is commonly quantified by measuring microvessel density\\u000a (MVD) within tumors. In this report, we compared light microscopy with confocal laser scanning microscopy (CLSM) in the qualitative\\u000a and quantitative analysis of angiogenesis. MVDs were determined manually in a lung tumor xenograft and a normal skeletal muscle\\u000a using CD31 immunohistochemical staining and light

Linlang Guo; Patricia Burke; Su-Hao Lo; Regina Gandour-Edwards; Derick Lau

2001-01-01

397

Foundations of Confocal Scanned Imaging in Light Microscopy  

Microsoft Academic Search

\\u000a Seldom has the introduction of a new instrument generated as instant an excitement among biologists as the laser-scanning\\u000a confocal microscope. With the new microscope, one can slice incredibly clean, thin optical sections out of thick fluorescent\\u000a specimens; view specimens in planes tilted to, and even running parallel to, the line of sight; penetrate deep into light-scattering\\u000a tissues; gain impressive three-dimensional

Shinya Inou

398

Lithographically-fabricated channel arrays for confocal x-ray fluorescence microscopy and XAFS  

NASA Astrophysics Data System (ADS)

Confocal X-ray Fluorescence Microscopy (CXRF) employs overlapping focal regions of two x-ray opticsa condenser and collectorto directly probe a 3D volume. The minimum-achievable size of this probe volume is limited by the collector, for which polycapillaries are generally the optic of choice. Recently, we demonstrated an alternative collection optic for CXRF, consisting of an array of micron-scale collimating channels, etched in silicon, and arranged like spokes of a wheel directed towards a single source position. The optic, while successful, had a working distance of only 0.2 mm and exhibited relatively low total collection efficiency, limiting its practical application. Here, we describe a new design in which the collimating channels are formed by a staggered array of pillars whose side-walls taper away from the channel axis. This approach improves both collection efficiency and working distance, while maintaining excellent spatial resolution. We illustrate these improvements with confocal XRF data obtained at the Cornell High Energy Synchrotron Source (CHESS) and the Advanced Photon Source (APS) beamline 20-ID-B.

Woll, Arthur R.; Agyeman-Budu, David; Choudhury, Sanjukta; Coulthard, Ian; Finnefrock, Adam C.; Gordon, Robert; Hallin, Emil; Mass, Jennifer

2014-03-01

399

Scanning a microhabitat: plant-microbe interactions revealed by confocal laser microscopy  

PubMed Central

No plant or cryptogam exists in nature without microorganisms associated with its tissues. Plants as microbial hosts are puzzles of different microhabitats, each of them colonized by specifically adapted microbiomes. The interactions with such microorganisms have drastic effects on the host fitness. Since the last 20 years, the combination of microscopic tools and molecular approaches contributed to new insights into microbe-host interactions. Particularly, confocal laser scanning microscopy (CLSM) facilitated the exploration of microbial habitats and allowed the observation of host-associated microorganisms in situ with an unprecedented accuracy. Here I present an overview of the progresses made in the study of the interactions between microorganisms and plants or plant-like organisms, focusing on the role of CLSM for the understanding of their significance. I critically discuss risks of misinterpretation when procedures of CLSM are not properly optimized. I also review approaches for quantitative and statistical analyses of CLSM images, the combination with other molecular and microscopic methods, and suggest the re-evaluation of natural autofluorescence. In this review, technical aspects were coupled with scientific outcomes, to facilitate the readers in identifying possible CLSM applications in their research or to expand their existing potential. The scope of this review is to highlight the importance of confocal microscopy in the study of plant-microbe interactions and also to be an inspiration for integrating microscopy with molecular techniques in future researches of microbial ecology. PMID:24639675

Cardinale, Massimiliano

2014-01-01

400

Combining microtomy and confocal laser scanning microscopy for structural analyses of plant-fungus associations.  

PubMed

The serious problem of extended tissue thickness in the analysis of plant-fungus associations was overcome using a new method that combines physical and optical sectioning of the resin-embedded sample by microtomy and confocal microscopy. Improved tissue infiltration of the fungal-specific, high molecular weight fluorescent probe wheat germ agglutinin conjugated to Alexa Fluor 633 resulted in high fungus-specific fluorescence even in deeper tissue sections. If autofluorescence was insufficient, additional counterstaining with Calcofluor White M2R or propidium iodide was applied in order to visualise the host plant tissues. Alternatively, the non-specific fluorochrome acid fuchsine was used for rapid staining of both, the plant and the fungal cells. The intricate spatial arrangements of the plant and fungal cells were preserved by immobilization in the hydrophilic resin Unicryl. Microtomy was used to section the resin-embedded roots or leaves until the desired plane was reached. The data sets generated by confocal laser scanning microscopy of the remaining resin stubs allowed the precise spatial reconstruction of complex structures in the plant-fungus associations of interest. This approach was successfully tested on tissues from ectomycorrhiza (Betula pendula), arbuscular mycorrhiza (Galium aparine; Polygala paniculata, Polygala rupestris), ericoid mycorrhiza (Calluna vulgaris), orchid mycorrhiza (Limodorum abortivum, Serapias parviflora) and on one leaf-fungus association (Zymoseptoria tritici on Triticum aestivum). The method provides an efficient visualisation protocol applicable with a wide range of plant-fungus symbioses. PMID:24249491

Rath, Magnus; Grolig, Franz; Haueisen, Janine; Imhof, Stephan

2014-05-01

401

Probe-based confocal laser endomicroscopy in head and neck malignancies: early preclinical experience  

NASA Astrophysics Data System (ADS)

Background: Malignancies of the upper aerodigestive tract (UADT) are conventionally diagnosed by white light endoscopy, biopsy and histopathology. Probe-based Confocal Laser Endomicroscopy (pCLE) is a novel non-invasive technique which offers in vivo surface and sub-surface imaging of tissue. It produces pictures of cellular architecture comparable to histology without the need for biopsy. It has already been successfully used in different clinical subspecialties to help in the diagnosis and treatment planning of inflammatory and neoplastic diseases. PCLE needs to be used in combination with specific or non-specific contrast agents. In this study we evaluated the potential use of pCLE in combination with non-specific and specific contrast agents to distinguish between healthy mucosa and invasive carcinoma. Methods: Tissue samples from healthy mucosa and squamous cell carcinoma of the head and neck were taken during surgery. After topical application of three different contrast agents, samples were examined using different pCLE-probes and a Confocal Laser Scanning Microscope (CLSM). Images were then compared to the corresponding histological slides and cryosections. Results: Initial results show that pCLE in combination with fluorophores allows visualization of cellular and structural components. Imaging of different layers was possible using three distinct pCLEprobes. Conclusion: pCLE is a promising non-invasive technique that may be a useful adjunct in the evaluation, diagnosis and treatment planning of head and neck malignancies.

Englhard, Anna; Girschick, Susanne; Mack, Brigitte; Volgger, Veronika; Gires, Oliver; Conderman, Christian; Stepp, Herbert; Betz, Christian Stephan

2013-06-01

402

Design and analysis of multi-color confocal microscopy with a wavelength scanning detector  

NASA Astrophysics Data System (ADS)

Spectral (or multi-color) microscopy has the ability to detect the fluorescent light of biological specimens with a broad range of wavelengths. Currently, the acousto-optic tunable filter (AOTF) is widely used in spectral microscopy as a substitute for a multiple-dichroic mirror to divide excitation and emission signals while maintaining sufficient light efficiency. In addition, systems which utilize an AOTF have a very fast switching speed and high resolution for wavelength selection. In this paper, confocal-spectral microscopy is proposed with a particular spectrometer design with a wavelength-scanning galvano-mirror. This enables the detection of broadband (480-700 nm) fluorescence signals by a single point detector (photomultiplier tube) instead of a CCD pixel array. For this purpose, a number of optical elements were applicably designed. A prism is used to amplify the dispersion angle, and the design of the relay optics matches the signals to the diameter of the wavelength-scanning galvano-mirror. Also, a birefringent material known as calcite is used to offset the displacement error at the image plane depending on the polarization states. The proposed multi-color confocal microscopy with the unique detection body has many advantages in comparison with commercial devices. In terms of the detection method, it can be easily applied to other imaging modalities.

Do, Dukho; Chun, Wanhee; Gweon, Dae-Gab

2012-05-01

403

High-frequency H-PDLC optical chopper for frequency division multiplexing fluorescence confocal microscope system  

NASA Astrophysics Data System (ADS)

The optical chopper array based on Holographic Polymer Dispersed Liquid Crystal (H-PDLC) working at high frequencies, for example 1KHz, 2KHz, and its application in an improved Frequency Division Multiplexed Fluorescence Confocal Microscope (FDMFCM) system are reported in this article. The system is a combination of the confocal microscopy and the frequency division multiplexing technique. Taking advantages of the optical chopper array based on H-PDLC that avoids mechanical movements, the FDMFCM system is able to obtain better Signal-Noise Ratio (SNR), smaller volume, more independent channels and more efficient scanning. What's more, the FDMCFM maintained the high special resolution ability and realized faster temporal resolution than pervious system. Using the proposed device, the FDMFCM system conducts successful parallel detection of rat neural cells. Fluorescence intensity signals from two different points on the specimen, which represent concentration of certain kind of proteins in the sample cells, are achieved. The experimental results show that the proposed H-PDLC optical chopper array has feasibility in FDMFCM system, which owes to its unique characteristics such as fast response, simple fabrication and lower consumption etc. With the development of H-PDLC based devices, there will be prospective in upgrading FDMFCM system's performance in the biomedical area.

Jiang, Yanmeng; Zheng, Jihong; Tang, Pingyu; Wang, Tingting; Huang, Aiqin; Zhou, Zengjun; Zhuang, Songlin

2011-10-01

404

Synchrotron infrared confocal microspectroscopical detection of heterogeneity within chemically modified single starch granules.  

PubMed

This reports the first detection of chemical heterogeneity in octenyl succinic anhydride modified single starch granules using a Fourier transform infrared (FT-IR) microspectroscopical technique that combines diffraction-limited infrared microspectroscopy with a step size that is less than the mask projected spot size focused on the plane of the sample. The high spatial resolution was achieved with the combination of the application of a synchrotron infrared source and the confocal image plane masking system of the double-pass single-mask Continuum infrared microscope. Starch from grains such as corn and wheat exists in granules. The size of the granules depends on the plant producing the starch. Granules used in this study typically had a median size of 15 microm. In the production of modified starch, an acid anhydride typically is reacted with OH groups of the starch polymer. The resulting esterification adds the ester carbonyl (1723 cm(-1)) organic functional group to the polymer and the hydrocarbon chain of the ester contributes to the CH(2) stretching vibration to enhance the intensity of the 2927 cm(-1) band. Detection of the relative modifying population on a single granule was accomplished by ratioing the baseline adjusted peak area of the carbonyl functional group to that of a carbohydrate band. By stepping a confocally defined infrared beam as small as 5 microm x 5 microm across a starch granule 1 mum at a time in both the x and y directions, the heterogeneity is detected with the highest possible spatial resolution. PMID:20223062

Wetzel, David L; Shi, Yong-Cheng; Reffner, John A

2010-03-01

405

Optical properties of silicon carbide for astrophysical applications. I. New laboratory infrared reflectance spectra and optical constants  

NASA Astrophysics Data System (ADS)

Aims: The SiC optical constants are fundamental inputs for radiative transfer (RT) models of astrophysical dust environments. However, previously published values contain errors and do not adequately represent the bulk physical properties of the cubic (?) SiC polytype usually found around carbon stars. We provide new, uncompromised optical constants for ?- and ?-SiC derived from single-crystal reflectance spectra and investigate quantitatively (i) whether there is any difference between ?- and ?-SiC that can be seen in infrared (IR) spectra and optical functions and (ii) whether weak features from ? 12.5-13.0 ?m need to be fitted. Methods: We measured mid- and far-IR reflectance spectra for two samples of 3C (?-)SiC and four samples of 6H (?-)SiC. For the latter group, we acquired polarized data (E bot c, E | c orientations). We calculated the real and imaginary parts of the complex refractive index (n(?) + ik(?)) and the ideal absorption coefficients via classical dispersion fits to our reflectance spectra. Results: We find that ?-SiC and E bot c ?-SiC have almost identical optical functions but that n(?) and k(?) for E | c ?-SiC are shifted to lower frequency. Peak positions determined for both 3C (?-) and 6H (?-)SiC polytypes agree with Raman measurements and show that a systematic error of 4 cm-1 exists in previously published IR analyses, attributable to inadequate resolution of older instruments for the steep, sharp modes of SiC. Weak modes are present for samples with impurities. Our calculated absorption coefficients are much higher than laboratory measurements. Whereas astrophysical dust grain sizes remain fairly unconstrained, SiC grains larger than about 1 ?m in diameter will be opaque at frequencies near the peak center. Conclusions: Previous optical constants for SiC do not reflect the true bulk properties, and they are only valid for a narrow grain size range. The new optical constants presented here will allow narrow constraints to be placed on the grain size and shape distribution that dominate in astrophysical environments. Tables 3-7 are only available in electronic form at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via http://cdsweb.u-strasbg.fr/cgi-bin/qcat?J/A+A/483/661

Pitman, K. M.; Hofmeister, A. M.; Corman, A. B.; Speck, A. K.

2008-05-01

406

Calibration of diode laser spectra using a confocal etalon  

NASA Technical Reports Server (NTRS)

The dual-beam diode laser spectrometer described by Jennings (1980) is adapted to use a 50-cm confocal etalon for frequency calibration. The collimated radiation from the laser is split at a wedged ZnSe window, and the reference beam is then focused at the midpoint of the etalon length. After the etalon, the reference beam is recollimated and continues its regular path to the monochromator and detectors. An aperture is placed before the etalon in order to limit the entrance beam diameter to approximately 5 mm. Both ends of the etalon are furnished with two-axis adjustments. Initial alignment is achieved using an He-Ne laser, and final optimization involves adjustment of the cavity length as well as the etalon pitch and yaw. The 50-cm confocal etalon produces fringes separated by 150 MHz (0.005/cm). With the aid of a CO2 laser, it is found to have fringe widths (FWHM) of 2 MHz. The confocal etalon makes it possible to improve the accuracy of relative frequency measurements in diode laser spectra and to check the spectral purity and stability of the laser during the recording of spectra.

Jennings, D. E.

1984-01-01

407

Simultaneous multiplane confocal microscopy using acoustic tunable lenses.  

PubMed

Maximizing the amount of spatiotemporal information retrieved in confocal laser scanning microscopy is crucial to understand fundamental three-dimensional (3D) dynamic processes in life sciences. However, current 3D confocal microscopy is based on an inherently slow stepwise process that consists of acquiring multiple 2D sections at different focal planes by mechanical or optical z-focus translation. Here, we show that by using an acoustically-driven optofluidic lens integrated in a commercial confocal system we can capture an entire 3D image in a single step. Our method is based on continuous axial scanning at speeds as high as 140 kHz combined with fast readout. In this way, one or more focus sweeps are produced on a pixel by pixel basis and the detected photons can be assigned to their corresponding focal plane enabling simultaneous multiplane imaging. We exemplify this method by imaging calibration and biological fluorescence samples. These results open the door to exploring new fundamental processes in science with an unprecedented time resolution. PMID:25321014

Duocastella, Mart; Vicidomini, Giuseppe; Diaspro, Alberto

2014-08-11

408

Quantification of Multilayer Samples by Confocal {mu}XRF  

SciTech Connect

The confocal setup consists of x-ray lenses in the excitation as well as in the detection channel. In this configuration, a micro volume defined by the overlap of the foci of both x-ray lenses is analyzed. Scanning this micro volume through the sample, 1-3 dimensional studies can be performed. For intermediate thin homogeneous layers a scanning in the normal direction to the surface sample provides information of its thickness and elemental composition. For multilayer samples it also provides the order of each layer in the stratified structure. For the confocal setup, we used a glass monocapillary in the excitation channel and a monolithic half polycapillary in the detection channel. The experiment was carried out at the D09B beamline of the LNLS using white beam. In the present work, a new algorithm was applied to analyze in detail by confocal {mu}XRF a sample of three paint layers on a glass substrate. Using the proposed algorithm, information about thickness and elemental densities was obtained for each layer of these samples.

Perez, R. Daniel; Sanchez, H. J.; Rubio, M. [Facultad de Matematica Astronomia y Fisica, Universidad Nacional de Cordoba, Ciudad Universitaria, Cordoba (5000) (Argentina); CONICET, Rivadavia 1917, Buenos Aires (1033) (Argentina); CEPROCOR, Ministerio de Ciencia y Tecnologia de Cordoba, Santa Maria de Punilla (5164), Cordoba (Argentina); Perez, C. A. [Laboratorio Nacional de Luz Sincrotron-LNLS, POB6192, 13084-97 Campinas, SP (Brazil)

2009-01-29

409

Segmentation of confocal microscopic image of insect brain  

NASA Astrophysics Data System (ADS)

Accurate analysis of insect brain structures in digital confocal microscopic images is valuable and important to biology research needs. The first step is to segment meaningful structures from images. Active contour model, known as snakes, is widely used for segmentation of medical images. A new class of active contour model called gradient vector flow snake has been introduced in 1998 to overcome some critical problems encountered in the traditional snake. In this paper, we use gradient vector flow snake to segment the mushroom body and the central body from the confocal microscopic insect brain images. First, an edge map is created from images by some edge filters. Second, a gradient vector flow field is calculated from the edge map using a computational diffusion process. Finally, a traditional snake deformation process starts until it reaches a stable configuration. User interface is also provided here, allowing users to edit the snake during deformation process, if desired. Using the gradient vector flow snake as the main segmentation method and assist with user interface, we can properly segment the confocal microscopic insect brain image for most of the cases. The identified mushroom and central body can then be used as the preliminary results toward a 3-D reconstruction process for further biology researches.

Wu, Ming-Jin; Lin, Chih-Yang; Ching, Yu-Tai

2002-05-01

410

[Application of Vis/NIR diffuse reflectance spectroscopy to the detection and identification of transgenic tomato leaf].  

PubMed

The feasibility of Vis/NIR spectroscopy technique for rapid and non-invasive detection of transgenic tomato leaves from conventional ones was investigated by means of spectral diffuse reflectance mode. A total of 68 samples (38 transgenic ones and 30 non-transgenic ones) were used for classification. The calibration and validation results were analyzed via discriminant analysis (DA) and partial least squares (PLS) discriminant method using TQ 6.2. 1 quantitative software. Models based on the different spectral pre-processing methods (multiplicative signal correction (MSC), first and second derivative) were compared. It was found that the classification accuracy using DA was higher than that using PLS and the best results were gained by using spectra after MSC with InGaAs detector and the classification accuracy was 89.7% (accuracy of 86.8% for transgenic samples and 93.3% for non-transgenic ones). The results show that Vis-NIR diffuse reflectance spectroscopy technique is a feasible and fast method for non-invasive detection of transgenic and non-transgenic tomato leaves. PMID:18720802

Xie, Li-Juan; Ying, Yi-Bin; Ying, Tie-Jin; Tian, Hai-Qing; Niu, Xiao-Ying; Fu, Xia-Ping

2008-05-01

411

Structural and optical properties of ITO/TiO2 anti-reflective films for solar cell applications  

PubMed Central

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. PMID:24721986

2014-01-01

412

Mirrors that reflect time  

NASA Astrophysics Data System (ADS)

The principles and potential applications of phase-conjugate mirrors (PCM) are explored. Light incident on a PCM is reflected as a complex conjugate of the incident wave, i.e., the phase is reversed. Additionally, a diverging beam is reflected as a converging beam back to its source. Phase conjugate reflections have been produced by light-induced heating, saturable stimulated emission and absorption, molecular orientation, electrostriction, surface deformation, charge migration, and photorefraction. The reflections have been obtained from solids, liquids, gases, plasmas, aerosols, and liquid crystals. Conjugate images have been generated with lasers to form holograms, where the laser wavelength determined the size of the image. The PCM effect has been applied to correcting aberrations due to imperfect optics such as windows, lenses, high power laser amplifiers, and the earth's atmosphere.

Gower, M.

1984-03-01

413

Simultaneous Refraction and Reflection Seismic Tomography Based on SIMULPS13Q With Applications to the TRANSALP Wide-Angle Data  

NASA Astrophysics Data System (ADS)

Seismic travel time tomography is restricted for the most part either to the direct wave or to 2D. Combined 3D refraction and reflection seismic inversion was first introduced by Zelt et al. (1996) using a "quasi-simultaneous" procedure of alternating inversions of a certain seismic phase and layer stripping. Based on the SIMULPS13Q version of the wide-spread SIMUL-code-family and the concepts of flexible gridding (Thurber, 1983-1999; Rietbrock, 1996) we developed a simultaneous 3D inversion for slowness and reflector depth. In a first step accuracy for large recording distances, crucial for the inversion of PMP or Pn observations, has been improved by resegmentation of the ray path and multiple path search. In a second step the modelling of reflectors and reflections and the simultaneous inversion of reflection and refraction travel times for velocity and reflector depth has been integrated. Reflectors are modelled by bi-cubic splines and can be "floating", i.e. without impact on the velocities, or discontinuous. This method has been applied to the TRANSALP refraction seismic data. TRANSALP is an international project for the investigation of the deep structure of the Eastern Alps (TRANSALP Working Group, 2001). The data consists of vibro- and explosion seismic signals recorded by 30 to 110 three-component stations distributed along a 220 km long segment of the profile. We obtained a high resolution model of the upper crust with 2.5 kms horizontal grid spacing which has been used for migration of the near-vertical data. The inverted Moho depth is consistent with older models. Rietbrock, A., 1996. Entwicklung eines Programmsystems zur konsistenten Auswertung grosser seismologischer Datensaetze mit Anwendung auf die Untersuchung der Absorptionsstruktur der Loma-Prieta-Region, Kalifornien. PhD-Thesis, University of Munich, 141 pp. Thurber, C.H., 1983. Earthquake locations and three-dimensional crustal structure in the Coyote Lake area, Central California. J. Geophys. Res. 88 (B10), 8226-8236 Thurber, C.H., Eberhart-Phillips, D., 1999. Local earthquake tomography with flexible gridding. Comp. Geosci. 25, 809-818 TRANSALP Working Group, 2001. European Orogenic Processes Research Transects the Eastern Alps, EOS 82 (40) Zelt, B.C., Ellis, R.M., Clowes, R.M., 1996. Inversion of three-dimensional wide-angle seismic data from the southwestern Candian Cordillera. J. Geophys. Res. 101 (B4), 8503-8529

Saikia, C. K.; Ichinose, G.; Simons, M.; Lohman, R.; Ji, C.; Helmberger, D. V.; Bleibinhaus, F.; Gebrande, H.

2002-05-01

414

The applicability of reflectance micro-Fourier-transform infrared spectroscopy for the detection of synthetic microplastics in marine sediments.  

PubMed

Synthetic microplastics (?5-mm fragments) are globally distributed contaminants within coastal sediments that may transport organic pollutants and additives into food webs. Although micro-Fourier-transform infrared (micro-FT-IR) spectroscopy represents an ideal method for detecting microplastics in sediments, this technique lacks a standardized operating protocol. Herein, an optimized method for the micro-FT-IR analysis of microplastics in vacuum-filtered sediment retentates was developed. Reflectance micro-FT-IR analyses of polyethylene (PE) were compared with attenuated total reflectance FT-IR (ATR-FT-IR) measurements. Molecular mapping as a precursor to the imaging of microplastics was explored in the presence and absence of 150-?m PE fragments, added to sediment at concentrations of 10, 100, 500 and 1000ppm. Subsequently, polymer spectra were assessed across plastic-spiked sediments from fifteen offshore sites. While all spectra obtained of evenly shaped plastics were typical to PE, reflectance micro-FT-IR measurements of irregularly shaped materials must account for refractive error. Additionally, we provide the first evidence that mapping successfully detects microplastics without their visual selection for characterization, despite this technique relying on spectra from small and spatially separated locations. Flotation of microplastics from sediments only enabled a fragment recovery rate of 61 (31 S.D.) %. However, mapping 3-mm(2) areas (within 47-mm filters) detected PE at spiking concentrations of 100ppm and above, displaying 69 (12 S.D.) % of the fragments in these locations. Additionally, mapping detected a potential PE fragment in a non-spiked retentate. These data have important implications for research into the imaging of microplastics. Specifically, the sensitivity and spatial resolution of the present protocol may be improved by visualizing the entire filter with high-throughput detection techniques (e.g., focal plane array-based imaging). Additionally, since micro-FT-IR analyses depend on methods of sample collection, our results emphasize the urgency of developing efficient and reproducible techniques to separate microplastics from sediments. PMID:22221871

Harrison, Jesse P; Ojeda, Jess J; Romero-Gonzlez, Mara E

2012-02-01

415

Simultaneous Refraction and Reflection Seismic Tomography Based on SIMUL With Applications to the TRANSALP Wide-Angle Data.  

NASA Astrophysics Data System (ADS)

Seismic travel time tomography is restricted for the most part either to the direct wave or to 2D. Combined 3D refraction and reflection seismic inversion of DSS data was introduced by Zelt et al. (1996) using a quasi-simultaneous procedure of alternating inversions of a certain seismic phase and layer stripping. We developed a 3D method to invert simultaneously for slowness and reflector depth in one step. It is based on the SIMULPS13Q version of the wide-spread SIMUL-code-family and the concepts of flexible gridding (Thurber, 1983-1999; Rietbrock, 1996). The ray tracing/bending accuracy for large recording distances, crucial for the inversion of PMP or Pn observations, has been improved by resegmentation of the ray path and multiple path search. Modelling of reflectors has been integrated using bi-cubic splines. Reflectors can be "floating", i.e. without impact on the velocities, or discontinuous. Reflections are modelled by grid search and bending techniques. Then the linearized tomographic approach has been extended to the inversion of reflection travel times for velocity and reflector depth and tested using synthetic data. This method has been applied to the TRANSALP wide-angle data. TRANSALP is an international project for the investigation of the deep structure of the Eastern Alps (TRANSALP Working Group, 2001,2002). The data consists of vibro- and explosion seismic signals recorded by 30 to 110 three-component stations distributed along a 220 km long segment of the profile. We obtained a model with 2.5 km x 10 km horizontal grid spacing in the upper crust decreasing to 20 km in the lower crust. Velocities at the surface correlate well with known geological boundaries and the inverted Moho depth is consistent with older models. The upper part of the Sub-Tauern ramp can be recognized by its low velocities. A LVL in the northern part of the profile is interpreted as top of the southward dipping European Basement. Rietbrock, A., 1996. Entwicklung eines Programmsystems zur konsistenten Auswertung grosser seismologischer Datensaetze mit Anwendung auf die Untersuchung der Absorptionsstruktur der Loma-Prieta-Region, Kalifornien. PhD-Thesis, University of Munich, 141 pp. / Thurber, C.H., 1983. Earthquake locations and three-dimensional crustal structure in the Coyote Lake area, Central California. J. Geophys. Res. 88 (B10), 8226-8236 / Thurber, C.H., Eberhart-Phillips, D., 1999. Local earthquake tomography with flexible gridding. Comp. Geosci. 25, 809-818 / TRANSALP Working Group, 2001. European Orogenic Processes Research Transects the Eastern Alps, EOS 82 (40) / TRANSALP Working Group, 2002. First deep seismic reflection images of the Eastern Alps reveal giant crustal wedges and transcrustal ramp. Geophys. Res. Letters 29 (10) / Zelt, B.C., Ellis, R.M., Clowes, R.M., 1996. Inversion of three-dimensional wide-angle seismic data from the southwestern Candian Cordillera. J. Geophys. Res. 101 (B4), 8503-8529

Bleibinhaus, F.; Helmut, G.; Transalp Working Group,.

2002-12-01

416

Spectrally encoded confocal microscopy of esophageal tissues at 100 kHz line rate  

PubMed Central

Spectrally encoded confocal microscopy (SECM) is a reflectance confocal microscopy technology that uses a diffraction grating to illuminate different locations on the sample with distinct wavelengths. SECM can obtain line images without any beam scanning devices, which opens up the possibility of high-speed imaging with relatively simple probe optics. This feature makes SECM a promising technology for rapid endoscopic imaging of internal organs, such as the esophagus, at microscopic resolution. SECM imaging of the esophagus has been previously demonstrated at relatively low line rates (5 kHz). In this paper, we demonstrate SECM imaging of large regions of esophageal tissues at a high line imaging rate of 100 kHz. The SECM system comprises a wavelength-swept source with a fast sweep rate (100 kHz), high output power (80 mW), and a detector unit with a large bandwidth (100 MHz). The sensitivity of the 100-kHz SECM system was measured to be 60 dB and the transverse resolution was 1.6 m. Excised swine and human esophageal tissues were imaged with the 100-kHz SECM system at a rate of 6.6 mm2/sec. Architectural and cellular features of esophageal tissues could be clearly visualized in the SECM images, including papillae, glands, and nuclei. These results demonstrate that large-area SECM imaging of esophageal tissues can be successfully conducted at a high line imaging rate of 100 kHz, which will enable whole-organ SECM imaging in vivo. PMID:24049684

Schlachter, Simon C.; Kang, DongKyun; Gora, Michalina J.; Vacas-Jacques, Paulino; Wu, Tao; Carruth, Robert W.; Wilsterman, Eric J.; Bouma, Brett E.; Woods, Kevin; Tearney, Guillermo J.

2013-01-01

417

Application of P-wave reflection imaging to unknown bridge foundations and comparison with other non-destructive test methods  

NASA Astrophysics Data System (ADS)

Proper design of bridge structures requires an appreciation for the possible failure mechanisms that can develop over the lifetime of the bridge, many of which are related to natural hazards. For example, scour is one of the most common causes of bridge failures. Scour occurs due to the erosion of soil and sediment within a channel with flowing water. During a flood event, the extent of scour can be so great that it can destabilize an existing bridge structure. In order to evaluate the scour potential of a bridge, it is necessary to have information regarding the substructure, particularly the bridge foundations. However, as of 2011 there are more than 40,000 bridges across United States with unknown foundations. Generally for these bridges there are no design or as-built plans available to show the type, depth, geometry, or materials incorporated into the foundations. Several non-destructive testing (NDT) methods have been developed to evaluate these unknown foundations. The primary objective of this research is to identify the most current and widely used NDT methods for determining the embedment depth of unknown bridge foundations and to compare these methods to an ultrasonic P-wave reflection imaging system. The ultrasonic P-wave reflection system has tremendous potential to provide more information and address several short-comings of other NDT methods. A laboratory study was initiated to explore various aspects related to the P-wave system performance, in order to characterize the limitations of the system in evaluation of unknown foundations prior to deployment in field studies. Moreover, field testing was performed using the P-wave system and a number of the current NDT methods at two selected bridge foundations to allow comparison between the results.

Kermani, Behnoud

418

Application of advanced seismic reflection imaging techniques to mapping permeable zones at Dixie Valley, Nevada. Final technical report  

SciTech Connect

Multifold seismic reflection data from the Dixie Valley geothermal field in Nevada were reprocessed using a nonlinear optimization scheme called simulated annealing to model subsurface acoustic velocities, followed by a pre-stack Kirchhoff migration to produce accurate and detailed depth-migrated images of subsurface structure. In contrast to conventional processing techniques, these methods account for significant lateral variations in velocity and thus have the potential ability to image steeply-dipping faults and fractures that may affect permeability within geothermal fields. The optimization scheme develops two-dimensional velocity models to within 6% of velocities obtained from well and surface geologic data. Only the seismic data (i.e., first arrival times of P waves) are used to construct the velocity models and pre-stack migration images, and no other a priori assumptions are invoked. Velocities obtained by processing individual seismic tracks were integrated to develop a block diagram of velocities to 2.3 km depth within the Dixie Valley geothermal field. Details of the tectonic and stratigraphic structure allowed three dimensional extension of the interpretations of two dimensional data. Interpretations of the processed seismic data are compared with well data, surface mapping, and other geophysical data. The Dixie Valley fault along the southeastern Stillwater Range Piedmont is associated with a pronounced lateral velocity gradient that is interpreted to represent the juxtaposition of relatively low velocity basin-fill strata in the hanging wall against higher velocity crystalline rocks in the footwall. The down-dip geometry of the fault was evaluated by inverting arrival times from a negative move-out event, which we associate with the dipping fault plane, on individual shot gathers for seismic line SRC-3 for the location and depth of the associated reflection points on the fault.

NONE

1998-02-18

419

Seismic Reflection and Refraction  

NSDL National Science Digital Library

This web site provides a brief introduction to the process of seismic exploration. Included are a definition of seismic exploration, a listing of possible applications of seismic methods, definitions of seismic reflection and refraction, and an explanation of data processing with seismic methods. The text descriptions are accompanied by visualizations helping to aid the reader in their understanding of the concepts discussed.

420

Spherical Reflections  

NSDL National Science Digital Library

In this art meets science activity, learners pack silver, ball-shaped ornaments in a single layer in a box to create an array of spherical reflectors. Learners can use this as a tool to study the properties of spherical mirrors while creating colorful mosaic reflections. This is a great optics activity to use during the holiday season or any time of year.

The Exploratorium

2011-12-07

421

Reflective Learning  

ERIC Educational Resources Information Center

In this article, the author presents his study of parent participation at an international school in Spain offering the British curriculum. He used quantitative methods and administered questionnaires to gather data that reflected the views of a large proportion of the school's parent community. He administered semi-structured interviews to gain a

Morales, Stephen

2011-01-01

422

Reflecting Squarely  

NSDL National Science Digital Library

In this problem students use spatial awareness and visualization to solve problems related to reflection (bilateral) symmetry. Learners are given three shapes and must assemble as many different but symmetrical composites as possible. Ideas for implementation, extension and support are included along with printable sheets of the shapes and a poster.

423

Applicability of direct total reflection X-ray fluorescence spectrometry for multielement analysis of geological and environmental objects  

NASA Astrophysics Data System (ADS)

The research aim is to demonstrate our experience in the applicability of TXRF analysis of various geological and environmental objects using minimal sample treatment. The study was focused on the evaluation of different factors affecting the TXRF results obtained for solid and liquid samples such as rock, mineral, ore, and natural water. Powdered geological samples were prepared as suspensions. Natural water samples were analyzed directly or after dilution. Testing various experimental parameters, e.g. sample amount, type of dispersant, and others was performed. For chosen conditions of the sample preparation procedure analytical figures of merit were estimated. Presented analytical results display the possibilities of TXRF applications in geological and environmental fields.

Cherkashina, T. Yu.; Panteeva, S. V.; Pashkova, G. V.

2014-09-01

424

Depth profiling of element concentrations in stratified materials by confocal microbeam X-ray fluorescence spectrometry with polychromatic excitation.  

PubMed

The confocal microbeam X-ray fluorescence technique is a well-established analytical tool that is widely used for qualitative and quantitative analysis of stratified materials. There are several different reco