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1

Reflecting on confocal microscopy: a personal perspective.  

PubMed

The first practical laser scanning confocal microscopes were introduced to the biomedical community over 30 years ago. Their subsequent development continues to influence the introduction of new methods and applications of optical sectioning microscopy. PMID:24052345

White, John

2014-01-01

2

Skin imaging with reflectance confocal microscopy.  

PubMed

Confocal microscopy is a new imaging modality for noninvasive real-time tissue imaging with high resolution and contrast comparable with conventional histology. Application of this technology to skin imaging during the last decade has been an exciting advance in dermatology, allowing a virtual widow into living skin without the need for a conventional biopsy or histologic processing of tissue. High-resolution noninvasive skin imaging with confocal microscopy has potential broad applications in the clinical and research arenas, including differentiating between benign and malignant skin lesions, tumor margin mapping, monitoring response to medical or surgical treatments, and pathophysiologic study of inflammatory processes. PMID:18486023

Nehal, Kishwer S; Gareau, Dan; Rajadhyaksha, Milind

2008-03-01

3

Anal melanosis diagnosed by reflectance confocal microscopy.  

PubMed

Until now, in vivo reflectance-mode confocal microscopy (IVCM) has been applied only to pigmented lesions of the vulvar and oral mucosa, but not to anal mucosa lesions. We present the first case in which IVCM has been used to diagnose anal melanosis. Clinical and dermoscopic features were of concern while IVCM found the draped pattern already described for genital melanosis. IVCM adds information to the clinical and dermatoscopic examination and allows skin biopsies to be avoided. Further studies are needed to define the IVCM features of anal melanosis and to compare the performance of IVCM with the findings of histological examinations. PMID:24004266

Cinotti, Elisa; Chol, Christelle; Perrot, Jean Luc; Labeille, Bruno; Forest, Fabien; Cambazard, Frédéric

2014-11-01

4

Evaluation of reflectance confocal microscopy in dermatophytosis.  

PubMed

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

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

2013-03-01

5

Single-wavelength reflected confocal and multiphoton microscopy for tissue imaging  

E-print Network

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

So, Peter T. C.

6

A handheld laser scanning confocal reflectance imagingconfocal Raman  

E-print Network

. Fredrich, "3D imaging of porous media using laser scanning confocal microscopy with application Cobleigh Hall, Bozeman, MT, 59717, USA *anita.mahadevan-jansen@vanderbilt.edu Abstract: Confocal-top microscopes, and are not suited for use outside of laboratory settings. We have developed a microscope which

Maxwell, Bruce D.

7

Automated identification of epidermal keratinocytes in reflectance confocal microscopy.  

PubMed

Keratinocytes in skin epidermis, which have bright cytoplasmic contrast and dark nuclear contrast in reflectance confocal microscopy (RCM), were modeled with a simple error function reflectance profile: erf(?). Forty-two example keratinocytes were identified as a training set which characterized the nuclear size a = 8.6±2.8 ?m and reflectance gradient b = 3.6±2.1 ?m at the nuclear?cytoplasmic boundary. These mean a and b parameters were used to create a rotationally symmetric erf(?) mask that approximated the mean keratinocyte image. A computer vision algorithm used an erf(?) mask to scan RCM images, identifying the coordinates of keratinocytes. Applying the mask to the confocal data identified the positions of keratinocytes in the epidermis. This simple model may be used to noninvasively evaluate keratinocyte populations as a quantitative morphometric diagnostic in skin cancer detection and evaluation of dermatological cosmetics. PMID:21456857

Gareau, Dan

2011-03-01

8

Automated identification of epidermal keratinocytes in reflectance confocal microscopy  

NASA Astrophysics Data System (ADS)

Keratinocytes in skin epidermis, which have bright cytoplasmic contrast and dark nuclear contrast in reflectance confocal microscopy (RCM), were modeled with a simple error function reflectance profile: erf( ). Forty-two example keratinocytes were identified as a training set which characterized the nuclear size a = 8.6+/-2.8 ?m and reflectance gradient b = 3.6+/-2.1 ?m at the nuclear/cytoplasmic boundary. These mean a and b parameters were used to create a rotationally symmetric erf( ) mask that approximated the mean keratinocyte image. A computer vision algorithm used an erf( ) mask to scan RCM images, identifying the coordinates of keratinocytes. Applying the mask to the confocal data identified the positions of keratinocytes in the epidermis. This simple model may be used to noninvasively evaluate keratinocyte populations as a quantitative morphometric diagnostic in skin cancer detection and evaluation of dermatological cosmetics.

Gareau, Dan

2011-03-01

9

Automated identification of epidermal keratinocytes in reflectance confocal microscopy  

PubMed Central

Keratinocytes in skin epidermis, which have bright cytoplasmic contrast and dark nuclear contrast in reflectance confocal microscopy (RCM), were modeled with a simple error function reflectance profile: erf(?). Forty-two example keratinocytes were identified as a training set which characterized the nuclear size a = 8.6±2.8 ?m and reflectance gradient b = 3.6±2.1 ?m at the nuclear/cytoplasmic boundary. These mean a and b parameters were used to create a rotationally symmetric erf(?) mask that approximated the mean keratinocyte image. A computer vision algorithm used an erf(?) mask to scan RCM images, identifying the coordinates of keratinocytes. Applying the mask to the confocal data identified the positions of keratinocytes in the epidermis. This simple model may be used to noninvasively evaluate keratinocyte populations as a quantitative morphometric diagnostic in skin cancer detection and evaluation of dermatological cosmetics. PMID:21456857

Gareau, Dan

2011-01-01

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

Specifying tissue optical properties using axial dependence of confocal reflectance images: confocal scanning laser microscopy and optical coherence tomography  

NASA Astrophysics Data System (ADS)

The optical properties of a tissue can be specified by the depth dependence of a reflectance-mode confocal measurement, as the focus is scanned down into a tissue. Reflectance-mode confocal scanning laser microscopy (rCSLM) and optical coherence tomography in focus tracking mode (OCT) are two examples of such confocal measurements. The measurement of reflected signal as a function of the depth of focus, R(z), is expressed as ?e -?z, where ? [dimensionless] is the local reflectivity from the focus within a tissue and ? [cm -1] is the attenuation of signal as a function of z. The reflectivity of a mirror defines ? = 1. This paper describes how the experimental ? and ? map into the optical properties of scattering coefficient, ?s [cm -1], and anisotropy of scattering, g [dimensionless]. Preliminary results on tissue for the rCSLM and OCT systems are reported.

Jacques, S.; Samatham, R.; Choudhury, N.; Gareau, D. S.

2007-02-01

12

Confocal microscopy patterns in nonmelanoma skin cancer and clinical applications.  

PubMed

Reflectance confocal microscopy is currently the most promising noninvasive diagnostic tool for studying cutaneous structures between the stratum corneum and the superficial reticular dermis. This tool gives real-time images parallel to the skin surface; the microscopic resolution is similar to that of conventional histology. Numerous studies have identified the main confocal features of various inflammatory skin diseases and tumors, demonstrating the good correlation of these features with certain dermatoscopic patterns and histologic findings. Confocal patterns and diagnostic algorithms have been shown to have high sensitivity and specificity in melanoma and nonmelanoma skin cancer. Possible present and future applications of this noninvasive technology are wide ranging and reach beyond its use in noninvasive diagnosis. This tool can also be used, for example, to evaluate dynamic skin processes that occur after UV exposure or to assess tumor response to noninvasive treatments such as photodynamic therapy. We explain the characteristic confocal features found in the main nonmelanoma skin tumors and discuss possible applications for this novel diagnostic technique in routine dermatology practice. PMID:24002008

González, S; Sánchez, V; González-Rodríguez, A; Parrado, C; Ullrich, M

2014-06-01

13

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 ìm lateral resolution using FLIM to 275 x 200 ?m2 with lateral resolution of 2.2 ?m using confocal microscopy, hamster cheek pouch model is imaged both in vivo and ex vivo. The results indicate that our dual modality imaging system can identify and distinguish between different tissue features, and, therefore, can potentially serve as a guide in early oral cancer detection..

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

2012-03-01

14

Detectability of reflectance and fluorescent contrast agents for real-time in vivo confocal microscopy  

Microsoft Academic Search

Reflectance agents (liposomes, polystyrene microparticles, aluminum chloride salts, acetic acid) and fluorescent agents (polymer- and cosmetic actives-tagged fluorescein and rhodamine compounds, green fluorescent protein) enhance contrast of real-time confocal images of skin and microcirculation in vivo. Quantitative analysis of signal detectability versus contrast agent properties, and experimental images are presented. These results provide a basis for optimizing confocal microscope design

Milind Rajadhyaksha; Salvador González

15

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 µm axial scan range using the tunable lens. The ability of the confocal endoscope to probe the human oral cavity is demonstrated by imaging of the oral mucosa in vivo. The results indicate that reflectance confocal endomicroscopy has the potential to be used in a clinical setting and guide diagnostic evaluation of biological tissue.

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

16

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

NASA Astrophysics Data System (ADS)

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

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

2013-04-01

17

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

PubMed Central

Abstract. Reflectance confocal microscopy (RCM) represents a noninvasive imaging technique that has previously been used for characterization of mycosis fungoides (MF) in a pilot study. We aimed to test the applicability of RCM for diagnosis and differential diagnosis of MF in a clinical study. A total of 39 test sites of 15 patients with a biopsy-proven diagnosis of either MF, parapsoriasis, Sézary syndrome, or lymphomatoid papulosis were analyzed for presence and absence of RCM features of MF. Cochran and Chi2 analysis were applied to test the concordance between investigators and the distribution of RCM features, respectively. For selected parameters, the Cochran analysis showed good concordance between investigators. Inter-observer reproducibility was highest for junctional atypical lymphocytes, architectural disarray, and spongiosis. Similarly, Chi2 analysis demonstrated that selected features were present at particularly high frequency in individual skin diseases, with values ranging from 73% to 100% of all examined cases. PMID:22352651

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

2012-01-01

18

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

E-print Network

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

Kaufman, Laura

19

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

20

Real-time laser differential confocal microscopy without sample reflectivity effects.  

PubMed

A new real-time laser differential confocal microscopy (RLDCM) without sample reflectivity difference effects is proposed for imaging height topography of sample surface, which divides the confocal microscopy imaging light path into two confocal microscopy imaging paths before and after focus with the equal axial detector offset oriented in opposite direction. By dividing the difference of the two signals simultaneously detected from these two confocal imaging paths by the higher signal between these two signals, RLDCM separates the signal that comes from reflectivity heterogeneity from the topographic signal in real time for the first time. RLDCM significantly reduces the height topography imaging time by single-layer scanning for the sample surface with reflectivity heterogeneity, and it achieves high axial resolution and lateral resolution similar to CM by optimizing the axial detector offset. Theoretical analysis and experimental results demonstrate that RLDCM realizes the real-time surface imaging for line structures featuring Silicon Dioxide steps on a Silicon base and achieves 2-nm axial depth resolution without reducing lateral resolution. PMID:25321541

Qiu, Lirong; Liu, Dali; Zhao, Weiqian; Cui, Han; Sheng, Zhong

2014-09-01

21

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

PubMed

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

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

2012-05-01

22

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

23

Measuring the lens focal length by laser reflection-confocal technology.  

PubMed

A laser reflection-confocal focal-length measurement (LRCFM) is proposed for the high-accuracy measurement of lens focal length. LRCFM uses the peak points of confocal response curves to precisely identify the lens focus and vertex of the lens last surface. LRCFM then accurately measures the distance between the two positions to determine the lens focal length. LRCFM uses conic fitting, which significantly enhances measurement accuracy by inhibiting the influence of environmental disturbance and system noise on the measurement results. The experimental results indicate that LRCFM has a relative expanded uncertainty of less than 0.0015%. Compared with existing measurement methods, LRCFM has high accuracy and a concise structure. Thus, LRCFM is a feasible method for high-accuracy focal-length measurements. PMID:23736337

Yang, Jiamiao; Qiu, Lirong; Zhao, Weiqian; Shao, Rongjun; Li, Zhigang

2013-06-01

24

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

25

A handheld electromagnetically actuated fiber optic raster scanner for reflectance confocal imaging of biological tissues.  

PubMed

We present a hand-held device aimed for reflectance-mode confocal imaging of biological tissues. The device consists of a light carrying optical fiber and a miniaturized raster scanner located at the distal end of the fiber. It is fabricated by mounting a polarization maintaining optical fiber on a cantilever beam that is attached to another beam such that their bending axes are perpendicular to each other. Fiber scanner is driven by electromagnetic forces and enables large fiber deflections with low driving currents. Optical resolutions of the system are 1.55 and 8.45 ?m in the lateral and axial directions, respectively. Functionality of the system is demonstrated by obtaining confocal images of a fly wing and a human colon tissue sample. PMID:23292783

Mansoor, Hadi; Zeng, Haishan; Tai, Isabella T; Zhao, Jianhua; Chiao, Mu

2013-05-01

26

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 Abelés matrix transfer methods. PMID:24233077

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

2013-01-01

27

Noninvasive imaging of melanoma with reflectance mode confocal scanning laser microscopy in a murine model.  

PubMed

A reflectance-mode confocal scanning laser microscope (rCSLM) was developed for imaging early-stage melanoma in a living mouse model without the addition of exogenous contrast agents. Lesions were first located by surveying the dorsum with a polarized light camera, then imaged with the rCSLM. The images demonstrated two characteristics of melanoma in this animal model: (1) melanocytes and apparent tumor nests in the epidermis at the stratum spinosum in a state of pagetoid spread and (2) architectural disruption of the dermal-epidermal junction. The epidermal melanocytes and apparent tumor nests had a high melanin content, which caused their reflectance to be fivefold greater than the surrounding epidermis. The rCSLM images illustrate the difference between normal skin and sites with apparent melanoma. This imaging modality shows promise to track the progression of melanoma lesions in animal models. PMID:17460734

Gareau, Daniel S; Merlino, Glenn; Corless, Christopher; Kulesz-Martin, Molly; Jacques, Steven L

2007-09-01

28

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

29

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

NASA Astrophysics Data System (ADS)

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

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

2002-06-01

30

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

31

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

32

[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

33

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

34

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

35

Melanocytic nevi with special features: clinical-dermoscopic and reflectance confocal microscopic-findings.  

PubMed

Histopathology is considered the 'gold' standard for the diagnosis and classification of melanocytic nevi, but the widespread use of in vivo diagnostic technologies such as dermoscopy and reflectance confocal microscopy (RCM), has enriched profoundly the knowledge regarding the morphological variability in nevi. This is because most morphological observations made via these in vivo tools are closely correlated with features seen in histopathology. Dermoscopy has allowed for a more detailed classification of nevi. As such, dermoscopy identifies four main morphologic groups (i.e. globular, reticular, starburst and structureless blue nevi), one group of nevi located at special body sites (i.e. face, acral, nail) and one group of nevi with special features. This latter category consists of nevi of the former categories, which are typified by peculiar clinical-histopathological findings. They can be subdivided into 'melanoma simulators' including combined nevi, recurrent nevi and sclerosing nevus with pseudomelanomatous features, 'targetoid' nevi (i.e. halo, cockade, irritated targetoid haemosiderotic and eczematous nevus) and uncommon histopathological variants such as desmoplastic, white dysplastic or ballon cell nevus. While the dermoscopic and RCM patterns of the former categories have been studied in detail, little is currently known about the clinical morphology of the heterogeneous group of 'special' nevi. In this article, we describe the clinical, dermoscopic and RCM features of 'special' nevi and review the current literature on this group of melanocytic proliferations. PMID:24171788

Larre Borges, A; Zalaudek, I; Longo, C; Dufrechou, L; Argenziano, G; Lallas, A; Piana, S; Moscarella, E

2014-07-01

36

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

37

Line-Scanning Reflectance Confocal Microscopy of Human Skin: Comparison of Full-pupil and Divided-pupil Configurations  

PubMed Central

Line-scanning, with pupil engineering and the use of linear array detectors, may enable simple, small and low-cost confocal microscopes for clinical imaging of human epithelial tissues. However, a fundamental understanding of line-scanning performance within the highly scattering and aberrating conditions of human tissue is necessary, to translate from benchtop instrumentation to clinical implementation. The results of a preliminary investigation for reflectance imaging in skin are reported. PMID:19838284

Gareau, Daniel S.; Abeytunge, Sanjee; Rajadhyaksha, Milind

2009-01-01

38

Line-scanning reflectance confocal microscopy of human skin: comparison of full-pupil and divided-pupil configurations.  

PubMed

Line-scanning, with pupil engineering and the use of linear array detectors, may enable simple, small, and low-cost confocal microscopes for clinical imaging of human epithelial tissues. However, a fundamental understanding of line-scanning performance within the highly scattering and aberrating conditions of human tissue is necessary, to translate from benchtop instrumentation to clinical implementation. The results of a preliminary investigation for reflectance imaging in skin are reported. PMID:19838284

Gareau, Daniel S; Abeytunge, Sanjee; Rajadhyaksha, Milind

2009-10-15

39

In vivo reflectance confocal microscopy of shave biopsy wounds: feasibility of intra-operative mapping of cancer margins  

PubMed Central

Background Reflectance confocal microscopy (RCM) images skin at cellular resolution and has shown utility for the diagnosis of nonmelanoma skin cancer in-vivo. Topical application of Aluminum Chloride (AlCl3) enhances contrast in RCM images by brightening nuclei. Objective To investigate feasibility of RCM imaging of shave biopsy wounds using AlCl3 as a contrast agent. Methods AlCl3 staining was optimized, in terms of concentration versus immersion time, on excised tissue ex-vivo. RCM imaging protocol was tested in patients undergoing shave biopsies. The RCM images were retrospectively analyzed and compared to the corresponding histopathology. Results For 35% AlCl3, routinely used for hemostasis in clinic, minimum immersion time was determined to be 1 minute. We identified 3 consistent patterns of margins on RCM mosaic images by varying depths: epidermal margins, peripheral dermal margins, and deep dermal margins. Tumour islands of basal cell carcinoma were identified at peripheral or deep dermal margins, correlating on histopathology with aggregates of neoplastic basaloid cells. Atypical cobblestone or honeycomb pattern were identified at the epidermal margins, correlating with a proliferation of atypical keratinocytes extending to biopsy margins. Conclusions RCM imaging of shave biopsy wounds is feasible and demonstrates the future possibility of intra-operative mapping in surgical wounds. PMID:20874785

Scope, A; Mahmood, U; Gareau, DS; Kenkre, M; Lieb, JA; Nehal, KS; Rajadhyaksha, M

2010-01-01

40

Full-pupil versus divided-pupil confocal line-scanners for reflectance imaging of human skin in vivo  

NASA Astrophysics Data System (ADS)

A full-pupil confocal line-scanning microscope is under development for imaging human skin in vivo in reflectance. The new design potentially offers an alternative to current point- and line-scanners that may simplify the optics, electronics and mechanics, and lead to simpler and smaller confocal microscopes. With a combination of a cylindrical lens and an objective lens, the line-scanner creates a focused line of laser light in the object plane within tissue. An oscillating galvanometric mirror scans the focused line transverse to its axis. The backscattered light from the tissue is de-scanned and focused onto a linear CMOS detector array. Preliminary measurements of the axial line-spread function, with a 30x, 0.9-NA water immersion objective lens and illumination wavelength of 633 nm, determined the optical sectioning to be 10 ?m. The new design is simple, requiring only eight optical components. However, the disadvantage is non-confocality in one dimension that results in 20% weaker sectioning than with a point-scanner, and reduced contrast in scattering tissue. The images of standard reflective targets such as a mirror and grating as well as dermis-like scattering target such as paper offer a preliminary glimpse into the performance of the line-scanner. A similar alternative design is the divided-pupil (theta) line-scanner, which provides 50% weaker sectioning than with a point scanner, but better contrast and less speckle due to the theta configuration. Such line scanners may prove useful for routine imaging of humans in clinical settings.

Gareau, Dan; Abeytunge, Sanjeewa; Rajadhyaksha, Milind

2007-02-01

41

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

42

Handheld subcellular-resolution single-fiber confocal microscope using high-reflectivity two-axis vertical combdrive silicon microscanner.  

PubMed

We introduce a handheld single-fiber laser-scanning confocal microscope, incorporating a high-reflectivity two-axis silicon vertical combdrive microscanner, aimed at in vivo early detection of epithelial precancers. The approach adopted is motivated by need for a portable, economical, biopsy-free, early precancer screening technology in low-infrastructure environments. Our microelectromechanical system (MEMS) based handheld probe integrates the microscanners with miniature objective lens system and flexible electrical routing in a forward-imaging configuration, with 4.8 mm distal probe tip outer diameter for unrestricted imaging access in biological sites such as the oral cavity and cervix. Reflectance confocal videos of a USAF 1951 resolution target and biological samples were obtained over 200 microm x 110 microm field of view, with 0.80 and 9.55 microm lateral and axial resolution, at 3.5-5.0 frames per second. With improvements to objective numerical aperture, our probe can enable precise evaluation of nuclear size, density, nucleus-to-cytoplasm ratio and cell density, which are important visual identifiers of epithelial precancers. PMID:18449642

Kumar, Karthik; Hoshino, Kazunori; Zhang, Xiaojing

2008-10-01

43

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

NASA Astrophysics Data System (ADS)

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

Ulrich, Martina; Lange-Asschenfeldt, Susanne

2013-06-01

44

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

NASA Astrophysics Data System (ADS)

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

C?runtu, Constantin; Boda, Daniel

2012-08-01

45

Confocal Microscopy of Bioconjugated Carbon Nanotubes for Biosensor Applications  

Microsoft Academic Search

Carbon nanotubes (CNTs) have many unique properties such as high surface area, hollow cavities, and excellent mechanical and electrical properties. Solubilization and biological functionalization of carbon nanotubes have greatly increased the usage of carbon nanotubes in biomedical applications such as biosensors and nanoprobes. This paper presents biofunctionalization of single wall carbon nanotubes (SWNT) with antibodies, which are specific to insulin-like

Kasif TEKER

46

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

47

Imaging melanoma in a murine model using reflectance-mode confocal scanning laser microscopy and polarized light imaging.  

PubMed

The light-scattering properties of cutaneous tissues provide optical contrast for imaging the presence and depth of pigmented melanoma in a highly pigmented murine model, the C57/B6 mouse. Early lesions are difficult to identify when viewing black lesions on a black mouse. Two methods were used to image early lesions in this model. (1) A reflectance-mode confocal scanning laser microscope (rCSLM) was built to provide horizontal images (x-y at depth z) and transverse images (x-z at position y) non-invasively in the living mouse. (2) A polarized light imaging (PLI) camera was built using a linearly polarized white light source that viewed the skin through an analyzing linear polarizer oriented either parallel or perpendicular to the illumination's polarization to yield two images, "PAR" and "PER," respectively. The difference image, PAR-PER, eliminated multiply scattered light and yielded an image of the superficial but subsurface tissues based only on photons scattered once or a few times so as to retain their polarization. rCSLM could image melanoma lesions developing below the epidermis. PLI could distinguish superficial from deeper melanoma lesions because the melanin of the superficial lesions attenuated the PAR-PER image, whereas deeper lesions failed to attenuate the PAR-PER image. PMID:16363066

Gareau, Daniel S; Lagowski, James; Rossi, Vincent M; Viator, John A; Merlino, Glenn; Kulesz-Martin, Molly; Jacques, Steven L

2005-11-01

48

Confocal microendoscopy with chromatic sectioning  

NASA Astrophysics Data System (ADS)

Placing a spatial light modulator, such as the Texas Instruments Digital Micromirror Device (DMD), in the light path of a microscope enables a variety of novel applications. One application enables reflectance in vivo confocal imaging of cells and tissue structure through a fiber-optic image guide. While multi-wavelength reflectance confocal microendoscopy with optical sectioning is a requirement for a clinically useful device, some form of axial scanning is also necessary. This is readily achieved using a multi-element lens system with some form of mechanical translation, however, this generally results in large probes and high cost. These limitations can be overcome using a two-element GRIN lens system in which the traditionally undesirable chromatic aberration of such a system can be exploited to allow for color-encoded optical sectioning. In our system a wavelength encoding range of 200 nm permits a sectioning range of 40 ?m from the tip of the probe into the tissue.

Lane, Pierre M.; Elliott, Robert P.; MacAulay, Calum E.

2003-07-01

49

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

50

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

51

Theoretical models and analytic expressions for buildup time of pulsed confocal unstable optical parametric oscillators with uniform or Gaussian reflectivity mirrors  

NASA Astrophysics Data System (ADS)

A theoretical model and a simplified analytic expression are developed to describe the buildup time of a pulsed confocal unstable optical parametric oscillator (OPO) with a uniform-reflectivity mirror (URM) or a Gaussian-reflectivity mirror (GRM). Two analytic expressions have been demonstrated to correspond to theoretical models with a sufficient degree of accuracy. The effects of a variety of cavity and pump parameters on the buildup time of an OPO were investigated and analyzed. It was found that a GRM unstable OPO generally exhibits a shorter buildup time than the corresponding URM unstable OPO with equally effective output coupling.

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

2005-10-01

52

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

NASA Astrophysics Data System (ADS)

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

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

2012-02-01

53

Assessment of microcirculatory influence on cellular morphology in human burn wound healing using reflectance-mode-confocal microscopy.  

PubMed

Previous studies have assessed the effects of changes in microcirculation on wound healing; however, the influence of microcirculation on tissue histomorphology remains widely unknown. Reflectance-mode-confocal microscopy (RMCM) enables in vivo tissue observation on a cellular level. We present RMCM data evaluating the local microcirculation and assess the influence on histomorphology during burn healing. RMCM was performed in 12 patients (aged; 36.2+/-14.2 years, maximum-burn-extent: 4% total body surface area) at times 12, 36, and 72 hours after a superficial burn. The following parameters were assessed: quantitative blood-cell-flow (cbf), epidermal thickness (Emin), basal-layer thickness (tbl), and granular cell-size (Agran). Cbf was found to be 54+/-3.6 cells/minutes (control), increased to 91+/-3.6 cells/minutes (p<0.05) 12 hours postburn; decreased to 71+/-6.1 cells/minutes (p<0.05) (36 hours), and to 63+/-2.3 cells/minutes (p>0.05) 72 hours postburn. Emin was 43.74+/-3.87 mum (control), increased to 51.67+/-4.04 mum (p<0.05) 12 hours, decreased to 48.67+/-3.51 mum (p<0.05) 36 hours, and to 45.33+/-3.21 mum (p>0.05) at 72 hours postburn. Tbl was 14.17+/-0.6 mum (control), increased to 16.93+/-1.15 mum (p<0.05) 12 hours, decreased to 15.93+/-1.20 mum (p<0.05) 32 hours, and to 15.00+/-0.85 mum (p>0.05) 72 hours postburn. Agran was 718+/-56.20 mum(2) (control), increased to 901+/-66.02 mum(2) (p<0.05) 12 hours, decreased to 826+/-56.86 mum(2) 36 hours, and 766+/-65.06 mum(2) at 72 hours postburn. RMCM enables in vivo observation of wound microcirculation and allows direct assessment of vascular effects on cutaneous histomorphology during the healing course of superficial burns. PMID:19614915

Altintas, Ahmet Ali; Altintas, Mehmet Ali; Ipaktchi, Kyros; Guggenheim, Merlin; Theodorou, Panagiotis; Theodorou, Pauangiotis; Amini, Peymaneh; Spilker, Gerald

2009-01-01

54

Chromatic confocal spectral interferometry  

SciTech Connect

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

Papastathopoulos, Evangelos; Koerner, Klaus; Osten, Wolfgang

2006-11-10

55

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

56

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

57

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

NASA Astrophysics Data System (ADS)

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

Han, Wenfeng; Xiao, Zexin; Wang, Xiaofen

2009-11-01

58

Dynamic experimentation on the confocal laser scanning microscope : application to soft-solid, composite food materials  

Microsoft Academic Search

Confocal laser scanning microscopy (CLSM) is used to follow the dynamic structural evolution of several phase-separated mixed biopolymer gel composites. Two protein\\/polysaccharide mixed gel systems were examined: gelatin\\/maltodextrin and gelatin\\/agarose. These materials exhibit 'emulsion-like' structures, with included spherical particles of one phase (i.e. polymer A) within a continuous matrix of the second (i.e. polymer B). Compositional control of these materials

K. P. Plucknett; S. J. Pomfret; V. Normand; D. Ferdinando; C. Veerman; W. J. Frith; I. T. Norton

2001-01-01

59

Application of regularized Richardson-Lucy algorithm for deconvolution of confocal microscopy images.  

PubMed

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, Richardson-Lucy 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

2011-08-01

60

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

61

Multi-confocal Fluorescence Correlation Spectroscopy : experimental demonstration and potential applications for living cell measurements  

E-print Network

We report, for the first time, a multi-confocal Fluorescence Correlation Spectroscopy (mFCS) technique which allows parallel measurements at different locations, by combining a Spatial Light Modulator (SLM), with an Electron Multiplying-CCD camera (EM-CCD). The SLM is used to produce a series of laser spots, while the pixels of the EM-CCD play the roles of virtual pinholes. The phase map addressed to the SLM is calculated by using the spherical wave approximation and makes it possible to produce several diffraction limited laser spots, either aligned or spread over the field of view. To attain fast enough imaging rates, the camera has been used in different acquisition modes, the fastest of which leads to a time resolution of 100 $\\mu$s. We qualified the experimental set-up by using solutions of sulforhodamine G in glycerol and demonstrated that the observation volumes are similar to that of a standard confocal set-up. To demonstrate that our mFCS method is suitable for intracellular studies, experiments have...

Galland, Rémi; Kloster, Meike; Herbomel, Gaetan; Destaing, Olivier; Balland, Martial; Souchier, Catherine; Usson, Yves; Derouard, Jacques; Wang, Irène; Delon, Antoine; 10.2741/e263

2011-01-01

62

Application of real-time confocal microscopy to intracellular calcium ion dynamics in rat arterioles.  

PubMed

The regulation of cytosolic Ca(2+) homeostasis is essential for cells, including vascular smooth muscle cells. Arterial tone, which underlies the maintenance of peripheral resistance in the circulation, is a major contributor to the control of blood pressure. Confocal microscopy was employed to study the alteration in intracellular calcium ion concentration ([Ca(2+)](i)) in arterioles (external diameters <100 microm) with respect to selected modifying reagents. 5-Hydroxytryptamine (1 microM), ATP (10 microM), and endothelin 1-3 (5 nM) elicited an increase in [Ca(2+)](i) in most arteriole smooth muscle cells. The [Ca(2+)](i) increase sometimes propagated in an intercellular manner. When noradrenaline (10 microM) was used as a stimulant, [Ca(2+)](i) increase was observed only in a portion of the smooth muscle cells. It was also noted that the reaction of these cells with respect to ATP is different between testis and brain arterioles; the [Ca(2+)](i) increase in testicular arterioles is dependent on Ca(2+) influx from extracellular space, whereas in cerebral arterioles it plays a role in both the influx of extracellular Ca(2+) and the release of Ca(2+) from intracellular stores (i.e., sarco/endoplasmic reticulum). These results indicate that arterioles in different tissues may differ greatly in their responses. Real-time confocal microscopy was found to be a useful tool for investigating the structural and functional changes in living tissues. PMID:11976902

Saino, Tomoyuki; Matsuura, Makoto; Satoh, Yoh-ichi

2002-04-01

63

Application of "in vivo cryotechnique" to detect erythrocyte oxygen saturation in frozen mouse tissues with confocal Raman cryomicroscopy.  

PubMed

To measure oxygen saturation (SO2) of flowing erythrocytes in blood vessels of living animals, our "in vivo cryotechnique" (IVCT) was combined with confocal Raman microscopy at low temperature (-150 degrees C), referred to as cryomicroscopy. We evaluated two resonance Raman (RR) shifts around 1355 and 1378 cm(-1), reflecting de-oxygenated and oxygenated hemoglobin molecular structures, respectively. Judging from the calibration analyses of quickly frozen human whole blood for the control experiment in vitro, the two RR shifts were well retained at the low temperature, and their calculated ratios mostly reflected the relative SO2 measured with a blood-gas analyzer. In blood vessels of living mouse organs prepared with the IVCT, their RR spectral peaks were also detected at the same RR shifts obtained in human blood. In the blood vessels of living mouse small intestines, some arterioles and venules were clearly distinguishable by monitoring different peak patterns of their RR shifts. The different ratios of the RR shift-areas were calculated even in the arterial vessels. In blood vessels of mouse livers, the Raman spectra showed a lower peak shift of 1378 cm(-1) compared to that of 1355 cm(-1), indicating an SO2 decrease in hepatic blood circulation. Thus, the new cryopreparation technique will enable us to directly analyze the in vivo SO2 in various tissues of a whole animal body prepared with the IVCT, reflecting their living states. PMID:18571433

Terada, Nobuo; Ohno, Nobuhiko; Saitoh, Sei; Ohno, Shinichi

2008-08-01

64

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

65

Broadband reflectance coatings for vacuum ultraviolet application  

NASA Astrophysics Data System (ADS)

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.

1987-02-01

66

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

67

Reflecting on the History, Ethics, and Application of Teacher Reflection.  

ERIC Educational Resources Information Center

Three social factors are related to the evolution of the discourse on teacher reflection: the role of educational researchers and teacher educators; the social and economic crisis and its impact on education; and the shift from behaviorism to cognitivism. By relating the discourse of teacher change through reflection to these social factors, it…

Hankes, Judith Elaine

68

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

NASA Astrophysics Data System (ADS)

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

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

2014-08-01

69

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

NASA Technical Reports Server (NTRS)

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

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

1997-01-01

70

Combined confocal Raman and quantitative phase microscopy system for biomedical diagnosis  

E-print Network

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

Kang, Jeon Woong

71

Restoration of three-dimensional quasi-binary images from confocal microscopy and its application to dendritic trees  

NASA Astrophysics Data System (ADS)

For the analysis of learning processes and the underlying changes of the shape of excitatory synapses (spines), 3-D volume samples of selected dendritic segments are scanned by a confocal laser scanning microscope. For a more detailed analysis, such as the classification of spine types, binary images of higher resolution are required. Simple threshold methods have disadvantages for small structures because the microscope point spread function (PSF) causes a darkening and a spread. The direction-dependent PSF leads to shape errors. To reconstruct structures and edge positions with a resolution smaller than one voxel a parametric model for the dendrite and the spines is created. In our application we use the known tree-like structure of the nerve cell as a- priori information. To create the model, simple geometrical elements (cylinders with hemispheres at the ends) are connected. The model can be adapted for size and position in sub-pixel domain. To estimate the quadratic error between the microscope image and the model, the model is sampled with the same resolution as the microscope image and convolved by the microscope PSF. During an iterative process the parameters of the model are optimized. In contrast to other pixel-based methods. the number of variable parameters is much slower. The influence of small deviations in the microscope image (caused by the inhomogeneous biological materials) is reduced.

Herzog, Andreas; Krell, Gerald; Michaelis, Bernd; Wang, Jizhong; Zuschratter, Werner; Braun, Anna K.

1997-04-01

72

Video-rate Scanning Confocal Microscopy and Microendoscopy  

PubMed Central

Confocal microscopy has become an invaluable tool in biology and the biomedical sciences, enabling rapid, high-sensitivity, and high-resolution optical sectioning of complex systems. Confocal microscopy is routinely used, for example, to study specific cellular targets1, monitor dynamics in living cells2-4, and visualize the three dimensional evolution of entire organisms5,6. Extensions of confocal imaging systems, such as confocal microendoscopes, allow for high-resolution imaging in vivo7 and are currently being applied to disease imaging and diagnosis in clinical settings8,9. Confocal microscopy provides three-dimensional resolution by creating so-called "optical sections" using straightforward geometrical optics. In a standard wide-field microscope, fluorescence generated from a sample is collected by an objective lens and relayed directly to a detector. While acceptable for imaging thin samples, thick samples become blurred by fluorescence generated above and below the objective focal plane. In contrast, confocal microscopy enables virtual, optical sectioning of samples, rejecting out-of-focus light to build high resolution three-dimensional representations of samples. Confocal microscopes achieve this feat by using a confocal aperture in the detection beam path. The fluorescence collected from a sample by the objective is relayed back through the scanning mirrors and through the primary dichroic mirror, a mirror carefully selected to reflect shorter wavelengths such as the laser excitation beam while passing the longer, Stokes-shifted fluorescence emission. This long-wavelength fluorescence signal is then passed to a pair of lenses on either side of a pinhole that is positioned at a plane exactly conjugate with the focal plane of the objective lens. Photons collected from the focal volume of the object are collimated by the objective lens and are focused by the confocal lenses through the pinhole. Fluorescence generated above or below the focal plane will therefore not be collimated properly, and will not pass through the confocal pinhole1, creating an optical section in which only light from the microscope focus is visible. (Fig 1). Thus the pinhole effectively acts as a virtual aperture in the focal plane, confining the detected emission to only one limited spatial location. Modern commercial confocal microscopes offer users fully automated operation, making formerly complex imaging procedures relatively straightforward and accessible. Despite the flexibility and power of these systems, commercial confocal microscopes are not well suited for all confocal imaging tasks, such as many in vivo imaging applications. Without the ability to create customized imaging systems to meet their needs, important experiments can remain out of reach to many scientists. In this article, we provide a step-by-step method for the complete construction of a custom, video-rate confocal imaging system from basic components. The upright microscope will be constructed using a resonant galvanometric mirror to provide the fast scanning axis, while a standard speed resonant galvanometric mirror will scan the slow axis. To create a precise scanned beam in the objective lens focus, these mirrors will be positioned at the so-called telecentric planes using four relay lenses. Confocal detection will be accomplished using a standard, off-the-shelf photomultiplier tube (PMT), and the images will be captured and displayed using a Matrox framegrabber card and the included software. PMID:22042305

Nichols, Alexander J.; Evans, Conor L.

2011-01-01

73

Identifying brain neoplasms using dye-enhanced multimodal confocal imaging.  

PubMed

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

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

2012-02-01

74

A hybrid vector quantizer for enhanced image pyramid coding with application to volumetric image compression in confocal microscopy  

NASA Astrophysics Data System (ADS)

Three-dimensional image compression methods outperform their two-dimensional counterparts in the sense of higher rate-distortion performance for compressing volumetric image data. The state-of-the-art transform-based 3D compressors, such as 3D-SPIHT and 3D-DCT, are characterized for their rate control ability, where the qualities of the image, although are adjustable with respect to rates, are not explicitly controllable. A novel method, based on vector quantization in an enhanced image pyramid with error feedback, has been proposed, where the quality of the decompressed image only depends on the encoding of coefficients from the finest band and therefore a distortion-constraint transform coding is achieved. Compared to the previous image pyramid transform coders, its coding efficiency has been improved by using a cross-band classified vector quantizer (CBCVQ), where the encoding of current band will benefit from the encoding result from previous bands. Two explicit bit-allocation schemes, one is regarding the bit allocation across bands and the other is across the sub vector quantizers within each band, have been applied to minimize the total rate under the constraint of specified distortion. Evaluations have been performed on several data sets obtained by confocal laser scanning microscopy (CLSM) scans for vascular remodeling study. The results show that the proposed method has competitive compression performance for volumetric microscopic images, compared to other state-of-the-art methods. Moreover the distortion-constraint feature offers more flexible control than its rate-constraint counterpart in bio-medical image applications. Additionally, it effectively reduces the artefacts presented in other approaches at low bit rates and therefore achieved more subjective acceptance.

Tao, Yegang; Cockshott, W. Paul

2005-02-01

75

Three-Dimensional Quasi-binary Image Restoration for Confocal Microscopy and Its Application to Dendritic Trees  

Microsoft Academic Search

For the analysis of learning processes and the underlying changes of the shape of excitatory synapses (spines), 3-D volume samples of selected dendritic segments are scanned by a confocal laser scanning microscope. The images are unsharp because of the (direction dependent) resolution limit. A simple deconvolution is not sufficient for the needed resolution.

Andreas Herzog I; Gerald Krell; Bernd Michaelis; Jizhong Wang; Werner Zuschratter; Katharina Braun

1997-01-01

76

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

Microsoft Academic Search

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

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

2003-01-01

77

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

Microsoft Academic Search

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

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

2004-01-01

78

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

NASA Astrophysics Data System (ADS)

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

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

2010-05-01

79

Reflection support for adaptive distributed applications  

Microsoft Academic Search

The DART (Distributed Adaptive Run-Time) project is developing an adaptive software environment for general-purpose distributed applications. The goal of the project is to provide a software run-time system that allows application authors to quickly develop distributed software, such as network or World Wide Web software, without having to deal with the details of the distribution technology. DART compile-time and run-time

Pierre-Guillaume Raverdy; Rodger Lea

1999-01-01

80

Confocal microscopy of hair  

Microsoft Academic Search

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

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

1994-01-01

81

Synthetic aperture confocal imaging  

Microsoft Academic Search

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

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

2004-01-01

82

Reflective Control for an Elastic Cloud Application: An Automated Experiment Workbench  

E-print Network

Reflective Control for an Elastic Cloud Application: An Automated Experiment Workbench Azbayar Demberel, Jeff Chase, and Shivnath Babu Duke University Abstract This paper addresses "reflective" control, an exter- nal reflective controller launches application functions based on knowledge of what resources

Chase, Jeffrey S.

83

Reflections  

NSDL National Science Digital Library

In this activity, learners play a game and use pattern blocks to explore mirror images and reflection. First, learners play the mirror game and try to follow everything the "leader" does but in a way that will look like a mirror image (reflections, not copies). Then, learners make reflections of each other's pattern block designs.

Exploratorium

2010-01-01

84

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.

Little, Carlyn; Lahart, David; Meyers, Ted; Weisblat, Brooks

1997-01-01

85

Shallow subsurface applications of high-resolution seismic reflection  

NASA Astrophysics Data System (ADS)

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

Steeples, Don

2002-11-01

86

Near real time confocal imaging of dysplasia in the oral cavity  

Microsoft Academic Search

The use of high resolution, in vivo confocal imaging may offer a clinical tool to detect early neoplasia and reduce the incidence and mortality of cancer. Our laboratory is currently examining the feasibility of using confocal microscopy for non-invasive diagnosis of dysplasia and early carcinoma in the oral cavity. This study uses a near real time reflectance confocal microscope to

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

2002-01-01

87

Confocal microscopy to measure tissue optical properties  

NASA Astrophysics Data System (ADS)

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 = ? exp(-? z focus), where ? [dimensionless] is the local reflectivity and ? [1/cm] is an attenuation coefficient. A simple theory for how p and ? depend on the optical properties of scattering (? s) and anisotropy (g) is presented. Experimental measurements on 5 tissue types from mice (white and gray matter of brain, skin, liver, muscle) as well as 0.1-?m-dia. polystyrene microspheres are presented. The tissues have similar ? s values (about 500 [1/cm]) but variable g values (0.8-0.99). Anisotropy appears to be the primary mechanism of contrast for confocal measurements such as reflectance-mode confocal laser scanning microscopy (rCLSM) and optical coherence tomography (OCT). While fluorescence imaging depends on fluorophores, and absorption imaging depends on chromophores, the results of this study suggest that contrast of confocal imaging of biological tissues depends primarily on anisotropy.

Jacques, Steven L.; Gareau, Daniel S.

2006-08-01

88

Electrostatic application of black flocking for reducing grazing incidence reflections  

NASA Astrophysics Data System (ADS)

Grazing incidence reflections as a source of stray light are a problem which continues to beleaguer optical systems and instrumentation. These reflections tend to be specular and are a primary cause of ghosting. Traditional means of blackening (absorption) fail miserably. Techniques of scattering the undesirable/problem light into a larger (and more benign) solid angle, while successful, are often impractical. Furthermore, while these techniques excel at reducing ghosting, they typically redirect significant light into the diffuse background, reducing the SNR. Black flocking combines the advantages of absorption and scattering. Historical disadvantages of flocking are its poor durability and the difficulty of applying flock to irregular surfaces. Presented here, is the technique of electrostatic application, which overcomes these shortfalls. BRDF (bi-directional reflectance distribution function) measurements of black flocking are presented and comparisons made with other blackening techniques. An example of this technique is shown where it is used to improve a low-light spectrographic instrument. Finally, proposed specifications for the application of (black) flocking are made for use in optics.

Vaughnn, David; Tome, Jay A.

1996-11-01

89

Learning through Reflective Classroom Practice: Applications to Educate the Reflective Manager  

ERIC Educational Resources Information Center

Reflection is an important yet often-neglected aspect of management performance. This article proposes that management educators take advantage of the contemplative classroom learning process by modeling and teaching reflective practice. A framework for conceptualizing reflective learning is presented. Reflection can result in deeper learning not…

Hedberg, Patricia Raber

2009-01-01

90

Novel design for a confocal endoscope  

NASA Astrophysics Data System (ADS)

Confocal imaging in an endoscopic format is currently under-utilized as a clinical investigative tool. This is due mainly to the complex, sensitive and costly scanning systems required to produce images. We hypothesize that design potential exists for an endoscope without any type of scanning system and that consequently can simultaneously acquire an entire confocal image frame. Our design exploits the parallel structure of fiber-optic image guides to eliminate all scanning hardware. The design is based upon developing a novel method to form a miniscule aperture on the end of each fiber in an image bundle. This process creates out-of-focus light rejection space between each fiber without changing the fiber spacing or the original outer diameter of the image guide. Our modified image guide can then be incorporated into an essentially typical endoscopic system. Using parallel apertures, a confocal endoscope or "conscope" can acquire images at a rate limited only by light intensity and the acquisition rate of a camera. The research presented in this paper shows the effects of adjusting pinhole diameter on confocal performance. The marriage of endoscopes, confocal imaging, parallel optical fibers, and the conscope design offers life science an ability to quickly observe deep, in-vivo cellular structures in their natural state. Although originally intended for endoscope applications, our design may benefit other forms of microscopy as well.

Pillers, Russell B.; Publicover, Nelson G.

2006-02-01

91

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

Code of Federal Regulations, 2011 CFR

... Navigation and Navigable Waters 2 2011-07-01 2011-07-01...applicant's proposal reflect potential regulations? 148.708... Navigation and Navigable Waters COAST GUARD, DEPARTMENT...applicant's proposal reflect potential regulations?...

2011-07-01

92

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

Code of Federal Regulations, 2012 CFR

... Navigation and Navigable Waters 2 2012-07-01 2012-07-01...applicant's proposal reflect potential regulations? 148.708... Navigation and Navigable Waters COAST GUARD, DEPARTMENT...applicant's proposal reflect potential regulations?...

2012-07-01

93

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

Code of Federal Regulations, 2013 CFR

... Navigation and Navigable Waters 2 2013-07-01 2013-07-01...applicant's proposal reflect potential regulations? 148.708... Navigation and Navigable Waters COAST GUARD, DEPARTMENT...applicant's proposal reflect potential regulations?...

2013-07-01

94

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

... Navigation and Navigable Waters 2 2014-07-01 2014-07-01...applicant's proposal reflect potential regulations? 148.708... Navigation and Navigable Waters COAST GUARD, DEPARTMENT...applicant's proposal reflect potential regulations?...

2014-07-01

95

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

Code of Federal Regulations, 2010 CFR

... Navigation and Navigable Waters 2 2010-07-01 2010-07-01...applicant's proposal reflect potential regulations? 148.708... Navigation and Navigable Waters COAST GUARD, DEPARTMENT...applicant's proposal reflect potential regulations?...

2010-07-01

96

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.

97

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

98

Feasibility of digitally stained multimodal confocal mosaics to simulate histopathology.  

PubMed

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

Gareau, Daniel S

2009-01-01

99

Use of confocal microscopy for nanoparticle drug delivery through skin  

NASA Astrophysics Data System (ADS)

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

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

2013-06-01

100

[Prosecution of psychiatric patients: elements of reflections and practical applications.].  

PubMed

Among possible solutions in response to violent behaviours of psychiatric patients, prosecution might not be an alternative as well-known. This measure may be potentially beneficial for patients. How can prosecution be chosen as an option when faced with violent patients? When this option is considered, how should it be applied and what are the different steps to follow? To answer these questions, it appeared essential to first proceed to a comprehensive reflection on the recourse of sanction in psychiatry. We then describe advantages and disadvantages of the judicial process. Finally, we illustrate applications as they were conceived and elaborated at the Clinique de dangerosité de l'Institut Philippe Pinel de Montréal. PMID:18253600

Bureau, N; Roy, R; Gendron, P; Millaud, F

2001-01-01

101

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

102

Camera-based reflectivity measurement for solar thermal applications  

E-print Network

tubes may be coated with anti-reflective surface coatings that minimise the reflection of the incident focussed solar radiation. The coating may in some cases fail, or be incorrectly or incompletely applied

103

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

104

The role of confocal microscopy in the dermato-oncology practice  

PubMed Central

Reflectance–mode confocal microscopy (RCM) is a new in vivo skin imaging technique. We present our one–year experience in RCM examinations in skin tumors and the retrospective analysis of patients enrolled in the Dermatological Department of ‘N. Paulescu’ Institute using the Fotofinder Dermoscope II? for the dermatoscopy analysis and VivaScope 1500? for in vivo RCM. We established the rank of RCM in the complex algorithm of skin cancer diagnose, showing that the presented experience can open new possibilities to implement this automated image analyzing system in the routine practice. Our analyzed cases clearly showed that confocal microscopy, therefore, optical biopsy, could guide the clinician towards an accurate diagnosis before surgical removal. Moreover, we emphasized that the development of this technique increases the potential of future teledermatologic applications. PMID:21505576

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

2011-01-01

105

Reflectance Spectroscopy: Quantitative Analysis Techniques for Remote Sensing Applications  

Microsoft Academic Search

Several methods for the analysis of remotely sensed reflectance data are compared, including empirical methods and scattering theories, both of which are important for solving remote sensing problems. The concept of the photon mean optical path length and the implications for use in modeling reflectance spectra are presented. It is shown that the mean optical path length in a particulate

Roger N. Clark; Ted L. Roush

1984-01-01

106

Application of Reflectance Spectroscopy for Analysis of Higher Plant Pigments  

Microsoft Academic Search

Nondestructive techniques developed by the authors for assessment of chlorophylls, carotenoids, and anthocyanins in higher plant leaves and fruits are presented. The spectral features of leaf reflectance in the visible and near infrared regions are briefly considered. For pigment analysis only reflectance values at several specific wavelengths are required. The chlorophyll (Chl) content over a wide range of its changes

M. N. Merzlyak; A. A. Gitelson; O. B. Chivkunova; A. E. Solovchenko; S. I. Pogosyan

2003-01-01

107

Electrostatic application of black flocking for reducing grazing incidence reflections  

Microsoft Academic Search

Grazing incidence reflections as a source of stray light are a problem which continues to beleaguer optical systems and instrumentation. These reflections tend to be specular and are a primary cause of ghosting. Traditional means of blackening (absorption) fail miserably. Techniques of scattering the undesirable\\/problem light into a larger (and more benign) solid angle, while successful, are often impractical. Furthermore,

David Vaughnn; Jay A. Tome

1996-01-01

108

Characterization of Single and Dual Layer Anti Reflecting Coating (ARC) for Solar Cell Applications  

Microsoft Academic Search

In this research, the characterization of single and dual layer of anti reflection coating films are studied. The research is aim to compare the performance of single and dual layer of anti reflection coating film for solar cell application. In addition, several types of anti reflection coating films are also studied. The research has been carried by using Silvaco TCAD.

A. S. Zoolfakar; S. R. S. Othman; M. H. Abdullah

2009-01-01

109

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

Microsoft Academic Search

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

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

2007-01-01

110

Diffuse reflection imaging at terahertz frequencies for security applications  

NASA Astrophysics Data System (ADS)

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

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

2007-10-01

111

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

112

Optical tweezers for confocal microscopy  

NASA Astrophysics Data System (ADS)

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

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

2000-11-01

113

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

114

Optimization of anti-reflective coatings for lithography applications  

Microsoft Academic Search

We present a new multilayer anti-reflective coating (ARC) optimization method. We have developed a software which allows the optimization of ARC consisting of up to 20 layers on any substrate with incident light integration over the aperture of lithography objectives and diffraction effects. The optimization includes not only the determination of optimal layer parameters (i.e. optical constants n and k,

J. Bauer; O. Fursenko; S. Virko; B. Kuck; Th. Grabolla; V. Melnik; W. Mehr

2005-01-01

115

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

NASA Astrophysics Data System (ADS)

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

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

2011-06-01

116

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

SciTech Connect

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

Suckewer, S.

1998-07-01

117

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

118

Affine reflection groups for tiling applications: Knot theory and DNA  

NASA Astrophysics Data System (ADS)

We present in this paper some non-conventional applications of affine Weyl groups Waff of rank 2, the symmetry group of the tiling/lattice. We first develop and present the tools for applications requiring tilings of a real Euclidean plane {R}^2. We then elucidate the equivalence of these tilings with 2D projections of knots. The resulting mathematical structure provides a framework within which is encompassed recent work utilizing knot theory for modeling the structure and function of genetic molecules, specifically the action of particular enzymes in altering the topology of DNA in site-specific recombination.

Bodner, M.; Patera, J.; Peterson, M.

2012-01-01

119

Reflective Middleware for Location-Aware Application Adaptation  

Microsoft Academic Search

Today mobile computing is pervasively taking over the traditional desktop computing. Mobile devices are characterized by abrupt and un- announced changes in execution context. The applications running on these de- vices need to be autonomous and thus dynamically adapt according to the changing context. Existing middleware support for the typical distributed appli- cations is strictly based on component technology. Future

Uzair Ahmad; S. Y. Lee; Mahrin Iqbal; Uzma Nasir; Arshad Ali; Mudeem Iqbal

2005-01-01

120

Application of 3D reflection seismic methods to mineral exploration  

NASA Astrophysics Data System (ADS)

Seismic exploration for mineral deposits is often tested by excessively complex structures, regolith heterogeneity, intrinsically low signal to noise ratio, ground relief and accessibility. In brown fields, where the majority of the seismic surveys have been conducted, existing infrastructure, old pits and tailings, heavy machinery in operation, mine drainage and other mine related activities are further challenging the application of seismic methods and furthermore increasing its cost. It is therefore not surprising that the mining industry has been reluctant to use seismic methods, particularly 3D for mineral exploration, primarily due to the high cost, but also because of variable performance, and in some cases ambiguous interpretation results. However, shallow mineral reserves are becoming depleted and exploration is moving towards deeper targets. Seismic methods will be more important for deeper investigations and may become the primary exploration tool in the near future. The big issue is if we have an appropriate seismic "strategy" for exploration of deep, complex mineral reserves. From the existing case histories worldwide we know that massive ore deposits (VMS, VHMS) constitute the best case scenario for the application of 3D seismic. Direct targeting of massive ore bodies from seismic has been documented in several case histories. Sediment hosted deposits could, in some cases, can also produce a detectable seismic signature. Other deposit types such as IOCG and skarn are much more challenging for the application of seismic methods. The complexity of these deposits requires new thinking. Several 3D surveys acquired over different deposit types will be presented and discussed.

Urosevic, Milovan

2013-04-01

121

Development and application of confocal scanning laser microscopy methods for studying the distribution of fat and protein in selected dairy products.  

PubMed

Confocal scanning laser microscopy (CSLM) methods were developed to identify fat and protein in cheeses milk chocolate and milk powders. Various fluorescent probes were assessed for their ability to label fat or protein in selected food products in situ. Dual labelling of fat and protein was made possible by using mixtures of probes. Selected probes and probe mixtures were then used to study (a) structure development of Mozzarella cheese during manufacture and ripening, and (b)) the distribution of fat and protein in milk chocolate made with milk powders containing varying levels of free fat. Microstructural changes in the protein and fat phases of Mozzarella cheese were observed at each major step in processing. Aggregation of renneted micelles occurred during curd formation; this was followed by amalgamation of the para-casein into linear fibres during plasticization. Following storage, the protein phase of the Mozzarella became more continuous; entrapping and isolating fat globules. Chocolate made with a high free-fat spray-dried powder blend showed a homogeneous fat distribution, similar to that of chocolate made with roller-dried milk. Chocolate made with whole milk powder containing 10 g free fat/100 fat showed a non-homogeneous fat distribution with some fat occluded within milk protein particles. These differences in fat distribution were related to Casson yield value and Casson viscosity of the chocolates. PMID:11694044

Auty, M A; Twomey, M; Guinee, T P; Mulvihill, D M

2001-08-01

122

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

123

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, Francois C.; Barnard, Alun R.; MacLaren, Robert E.

2012-01-01

124

Quantitative confocal spiral phase contrast.  

PubMed

We demonstrate quantitative phase delay measurements with a spiral phase contrast microscope working in confocal mode. Such a confocal configuration is sensitive to weak phase objects due to background rejection but does not give direct access to the phase delay introduced by the sample. We develop a theory showing that shifting the illumination spot relative to the detector gives access to the local phase gradient in the first-order approximation. Subsequently, we present an iterative integration algorithm for phase delay measurements. This approach is validated on simulated and calibrated experimental images. Finally, the algorithm is applied to measure the phase profile of a cell, in which phase delays of 10 mrad are observed. PMID:24977359

Guillon, Marc; Lauterbach, Marcel A

2014-06-01

125

Confocal microscopy of thick specimens.  

PubMed

Confocal microscopy is an excellent tool to gain structural information from deep within a biological sample. The depth from which information can be extracted as well as the resolution of the detection system are limited by spherical aberrations in the laser pathway. These spherical aberrations of the visible light can be efficiently canceled by optimizing the refractive index of the immersion media. Another way of cancelling spherical aberrations is by changing tube length, or alternatively, by changing the objective from infinite correction to finite correction, or vice versa, depending on which microscope is used. A combination of these two methods allows for confocal imaging at continuous depths. Presently, confocal microscopes typically operate at a maximum depth of 40 microm in the sample, but with the methods presented here, we show that information can easily be gained from depths up to 100 microm. Additionally, the precision of localization of a single fluorophore in the axial direction, limited by spherical aberrations, can be significantly improved, even if the fluorophore is located deep within the sample. In principle, this method can improve the efficiency of any kind of microscopy based on visible light. PMID:19566294

Reihani, S Nadar S; Oddershede, Lene B

2009-01-01

126

Confocal fluorescence microendoscopy using a digital micro-mirror device  

NASA Astrophysics Data System (ADS)

A design of confocal fluorescence microendoscopy utilizing a digital micro-mirror device (DMD) is described. Laser beams of the microendoscope are coupled into the body through a telescopic optics system, rather than through fibers or fiber bundles which are widely used in existing microendoscopes. Each micro-mirror of the DMD is used as a confocal pinhole. The DMD not only couples the laser beams into the body by a random time-varying speckle pattern and performs the scanning mechanism of the body tissue with different positions, but also couples the fluorescent signal emitted from the markers out to the CCD camera. Because of the CCD's integration feature and DMD's rapid parallel scanning feature, a complete predetermined depth tomography image accumulated by different scanning patterns of DMD can be acquired through only one CCD exposure procedure. The objective lens to realize high resolution and high sensitivity fluorescence imaging is the other function of the telescopic optics, with a numerical aperture of 0.35. The resolution of confocal microendoscope is superior to 228 lp/mm determined by 1951USAF resolution test target. Images of a tendon specimen are also shown to demonstrate practical application of the design. The confocal microendoscope using a DMD permits the acquisition of high-resolution real-time confocal images of epithelial tissue in vivo organ and realizes the aim of non-invasive diagnosis and treatment.

Feng, Zhifeng; Wang, Liqiang; Duan, Huilong

2010-11-01

127

Simplified confocal microscope for counting particles at low concentrations  

PubMed Central

We describe a compact scanning confocal fluorescence microscope capable of detecting particles concentrations less than 100 particles/ml in ?15 min. The system mechanically moves a cuvette containing ?3 ml of sample. A relatively large confocal volume is observed within the cuvette using a 1 mm pinhole in front of a detection PMT. Due to the motion of the sample, particles traverse the confocal volume quickly, and analysis by pattern recognition qualifies spikes in the emission intensity data and counts them as events. We show linearity of detection as a function of concentration and also characterize statistical behavior of the instrument. We calculate a detection sensitivity of the system using 3 ?m fluorescent microspheres to be 5 particles/ml. Furthermore, to demonstrate biological application, we performed a dilution series to quantify stained E. coli and yeast cells. We counted E. coli cells at a concentration as low as 30 cells/ml in 10 min/sample. PMID:23902088

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

2013-01-01

128

Confocal Raman Imaging of Polymeric Materials  

NASA Astrophysics Data System (ADS)

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

Schmidt, Ute; Müller, Jörg; Koenen, Joachim

129

Fungal Keratitis - Improving Diagnostics by Confocal Microscopy  

PubMed Central

Purpose Introducing a simple image grading system to support the interpretation of in vivo confocal microscopy (IVCM) images in filamentous fungal keratitis. Setting Clinical and confocal studies took place at the Department of Ophthalmology, Aarhus University Hospital, Denmark. Histopathological analysis was performed at the Eye Pathology Institute, Department of Neuroscience and Pharmacology, University of Copenhagen, Denmark. Methods A recent series of consecutive patients with filamentous fungal keratitis is presented to demonstrate the results from in-house IVCM. Based upon our experience with IVCM and previously published images, we composed a grading system for interpreting IVCM images of filamentous fungal keratitis. Results A recent case series of filamentous fungal keratitis from 2011 to 2012 was examined. There were 3 male and 3 female patients. Mean age was 44.5 years (range 12–69), 6 out of 17 (35%) cultures were positive and a total of 6/7 (86%) IVCM scans were positive. Three different categories of IVCM results for the grading of diagnostic certainty were formed. Conclusion IVCM is a valuable tool for diagnosing filamentous fungal keratitis. In order to improve the reliability of IVCM, we suggest implementing a simple and clinically applicable grading system for aiding the interpretation of IVCM images of filamentous fungal keratitis. PMID:24474933

Nielsen, E.; Heegaard, S.; Prause, J.U.; Ivarsen, A.; Mortensen, K.L.; Hjortdal, J.

2013-01-01

130

Dielectric anti-reflection coating application in a 0.175 ?m dual-damascene process  

Microsoft Academic Search

Various dielectric anti-reflection coatings (DARCs) were evaluated using 0.175 ?m dual-damascene structures to examine the lithography process window and integration capability. Double-DARC layers have been developed with the optimum refractive indices and thickness, based on reflectance simulations and measurements, to provide better critical dimension (CD) control as compared to organic ARC and single-DARC layer applications. The integration scheme using a

G. Y. Lee; Z. G. Lu; D. M. Dobuzinsky; X. J. Ning; G. Costrini

1998-01-01

131

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

PubMed Central

To optimize imaging of cells in three dimensional culture we studied confocal backscattering, Second Harmonic Generation (SHG) and autofluorescence as source of contrast in extracellular matrix (ECM) mimics and evaluated the attenuation as well as bleaching of endogenous cellular fluorescence signals. All common ECM mimics exhibit contrast observable with confocal reflectance microscopy. SHG imaging on collagen I based hydrogels provides high contrast and good optical penetration depth. Agarose is a useful embedding medium because it allows for large optical penetration and exhibits minimal autofluorescence while still providing good reflectance to detect voids in the embedding medium. We labeled breast cancer cells’ outline with DsRed2 and nucleus with eGFP. DsRed2 can be excited with confocal imaging at 568nm, and with two photon excitation (TPE) in the red and longer NIR. eGFP was excited at 488nm for confocal and in the NIR for TPE. While there is small difference in the bleaching rate for eGFP between confocal and TPE we observed significant difference for DsRed2 where bleaching is strongest during TPE in the red wavelengths and smallest during confocal imaging. After a few hundred microns depth in a collagen I hydrogel, TPE fluorescence becomes twice as strong compared to confocal imaging. PMID:23380006

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

2013-01-01

132

Study of liquid jet instability by confocal microscopy  

NASA Astrophysics Data System (ADS)

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

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

2012-07-01

133

The feasibility of digitally stained multimodal confocal mosaics to simulate histopathology  

PubMed Central

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

Gareau, Daniel S.

2010-01-01

134

High resolution, molecular-specific, reflectance imaging in optically dense tissue phantoms with structured-illumination  

Microsoft Academic Search

Structured-illumination microscopy delivers confocal-imaging capabilities and may be used for optical sectioning in bio-imaging applications. However, previous structured-illumination implementations are not capable of imaging molecular changes within highly scattering, biological samples in reflectance mode. Here, we present two advances which enable successful structured illumination reflectance microscopy to image molecular changes in epithelial tissue phantoms. First, we present the sine approximation

Tomasz S. Tkaczyk; Mohammed Rahman; Vivian Mack; Konstantin Sokolov; Jeremy D. Rogers; Rebecca Richards-Kortum; Michael R. Descour

2004-01-01

135

Tracheobronchial amyloidosis and confocal endomicroscopy.  

PubMed

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 outlines the imperfect, essentially palliative management of this rare disease, and shows for the first time the unusual dappled in vivo pCLE images of amyloid-affected endobronchium. PMID:21430359

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

2011-01-01

136

Confocal imaging through an endoscopic rod  

NASA Astrophysics Data System (ADS)

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

Galloway, Matt; Gabriel, Kayla; Dobre, George

2014-01-01

137

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

138

Measurement of grain size of polycrystalline materials with confocal energy dispersive micro-X-ray diffraction technology based on polycapillary X-ray optics  

NASA Astrophysics Data System (ADS)

The confocal energy dispersive micro-X-ray diffraction (EDMXRD) based on polycapillary X-ray optics was used to determine the grain size of polycrystalline materials. The grain size of a metallographic specimen of nickel base alloy was measured by using the confocal EDMXRD. The experimental results demonstrated that the confocal EDMXRD had potential applications in measuring large grain size.

Sun, Weiyuan; Liu, Zhiguo; Sun, Tianxi; Peng, Song; Ma, Yongzhong; Li, Fangzuo; Sun, Xuepeng; Ding, Xunliang

2014-11-01

139

Confocal fluctuation spectroscopy and imaging.  

PubMed

Currently, work with subnanomolar concentrations is routine while femtomolar and even single-molecule studies are possible with some efforts getting high on single-molecule biophysics and biochemistry. Methodological breakthroughs, such as reducing the background light contribution in single-molecule studies, which has plagued many studies of molecular fluorescence in dilute solution, and particularly in live cells, have recently described by us. We first demonstrated how optimized time-gating of the fluorescence signal, together with time-correlated, single-photon counting, can be used to substantially boost the experimental signal-to-noise ratio about 140-fold, making it possible to measure analyte concentrations that are as low as 15 pM. By detection of femtomolar bulk concentrations, confocal microsopy has the potential to address the observation of one and the same molecule in dilute solution without immobilization or hydrodynamic/electrokinetic focusing at longer observation times than currently available. We present relevant physics. The equations are derived using Einstein's approach showing how it fits with Fick's law and the autocorrelation function. An improved technology is being developed at ISS for femtomolar microscopy. The general concepts and provided experimental examples should help to compare our approach to those used in conventional confocal microscopy. PMID:20497113

Földes-Papp, Zeno; Liao, Shih-Chu Jeff; You, Tiefeng; Terpetschnig, Ewald; Barbieri, Beniamino

2010-09-01

140

Design and fabrication of reflective optical systems for space and tactical flight applications  

Microsoft Academic Search

The design and fabrication of seven all-reflective optical telescopes for a range of spaceborne and tactical applications are described. These telescopes are: ZIP (Zodiacal Infrared Program), CIRRIS I and IA (Cryogenic Infrared Radiance Instrument for Shuttle), SPIRIT I and II (Spatial Infrared Rocket-borne Interferometer Telescope), CLAES (Cryogenic Limb Array Etalon Spectrometer), ASMP (Advanced Sensor Measurement Program), BMAP (Background Measurements Analysis

Michael I. Anapol; Andrew A. Mastandrea

1989-01-01

141

Using Reflection for Incorporating Fault-Tolerance Techniques into Distributed Applications*  

E-print Network

1 Using Reflection for Incorporating Fault-Tolerance Techniques into Distributed Applications* Anh robust to failures. RGE encourages system developers to express fault-tolerance algorithms in terms of transformations on the data structures that represent computations-- messages and methods--hence enabling

Grimshaw, Andrew

142

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

143

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

144

Confocal Microscopy-Guided 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 control—ie, 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

145

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

PubMed

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 x 12 mm (which is equivalent to a 2x-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

2008-01-01

146

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

E-print Network

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

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

2010-01-01

147

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

E-print Network

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

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

2010-10-09

148

Video confocal microscopy of amelanotic tissue: Dynamics of aceto-whitening enable nuclear segmentation  

NASA Astrophysics Data System (ADS)

High resolution, in vivo confocal imaging of amelanotic epithelial tissue may offer a clinically useful adjunct to standard histopathologic techniques. Application of acetic acid has been shown to enhance contrast in confocal images of these tissues. In this study, we record the time course of aceto-whitening at the cellular level and determine whether the contrast provided enables quantitative feature analysis. Confocal images and videos of cervical specimens were obtained throughout the epithelium before, during and post-acetic acid after the application of 6% acetic acid. Aceto-whitening occurs within seconds after the application. The confocal imaging system resolved sub-cellular detail throughout the entire epithelial thickness and provided sufficient contrast to enable quantitative feature analysis.

Collier, Tom; Shen, Peggy; de Pradier, Benoit; Sung, Kung-Bin; Richards-Kortum, Rebecca R.; Follen, Michele; Malpica, Anais

2000-01-01

149

Measured energy savings from the application of reflective roofsin 2 small non-residential buildings  

SciTech Connect

Energy use and environmental parameters were monitored in two small (14.9 m{sup 2}) non-residential buildings during the summer of 2000. The buildings were initially monitored for about 1 1/2 months to establish a base condition. The roofs of the buildings were then painted with a white coating and the monitoring was continued. The original solar reflectivities of the roofs were about 26%; after the application of roof coatings the reflectivities increased to about 72%. The monitored electricity savings were about 0.5kWh per day (33 Wh/m2 per day). The estimated annual savings are about 125kWh per year (8.4 kWh/m2); at a cost of $0.1/kWh, savings are about $0.86/m2 per year. Obviously, it costs significantly more than this amount to coat the roofs with reflective coating, particularly because of the remote locations of these buildings. However, since the prefabricated roofs are already painted green at the factory, painting them a white (reflective) color would bring no additional cost. Hence, a reflective roof saves energy at no incremental cost.

Akbari, Hashem

2003-01-14

150

Application of backward diffuse reflection spectroscopy for monitoring the state of tissues in photodynamic therapy  

SciTech Connect

The application of backward diffuse reflection (BDR) spectroscopy for in vivo monitoring the degree of haemoglobin oxygenation and concentration of photosensitisers in tissues subjected to photodynamic therapy is demonstrated. A simple experimental technique is proposed for measuring diffuse reflection spectra. The measurements are made under steady-state conditions using a fibreoptic probe with one transmitting and one receiving fibre separated by a fixed distance. Although this approach does not ensure the separation of contributions of scattering and absorption to the spectra being measured, it can be used for estimating the degree of haemoglobin oxygenation and concentration of photosensitisers in the tissues. Simple expressions for estimating the concentration of photosensitisers from the BDR spectra are presented and the accuracy of this approach is analysed. The results of application of BDR spectroscopy for monitoring various photosensitisers are considered. (special issue devoted to multiple radiation scattering in random media)

Stratonnikov, Aleksandr A; Meerovich, G A; Ryabova, A V; Savel'eva, T A; Loshchenov, V B [Natural Science Center, A.M. Prokhorov General Physics Institute, Russian Academy of Sciences, Moscow (Russian Federation)

2006-12-31

151

Lieb's Spin-Reflection-Positivity Method and Its Applications to Strongly Correlated Electron Systems  

Microsoft Academic Search

In this paper, we discuss the spin-reflection-positivity method introduced by Lieb [E. H. Lieb, Phys. Rev. Lett.62:1201 (1989)] and its applications to strongly correlated electron systems in a pedagogical manner. We emphasize the important role played by the sign rule of the ground-state wave function in studying a many-body system. To make our explanation more readable, we shall first review

Guang-Shan Tian

2004-01-01

152

Measured Energy Savings from the Application of Reflective Roofs in 3 AT and T Regeneration Buildings  

SciTech Connect

Energy use and environmental parameters were monitored in three AT and T regeneration buildings during the summer of 2000. These buildings are constructed with concrete and are about 14.9 m2 (160 f2; 10x16 ft)in size. The buildings were initially monitored for about 1 1/2 months to establish a base condition. Then, the roofs of the buildings were painted with a white coating and the monitoring was continued. The original roof reflectances were about 26 percent; after the application of roof coatings the reflectivities increased to about 72 percent. In two of these buildings, we monitored savings of about 0.5kWh per day (8.6 kWh/m2 [0.8 kWh/ft2]). The third building showed a reduction in air-conditioning energy use of about 13kWh per day. These savings probably resulted from the differences in the performance (EER) of the two dissimilar AC units in this building. The estimated annual savings for two of the buildings are about 125kWh per year; at a cost of dollar 0.1/kWh, savings are about dollar 12.5 per year. Obviously, it costs significantly more than this amount to coat the roofs with reflective coating, particularly because of the remote location of the buildings. However, since the prefabricated roofs are already painted green at the factory, painting them with white (reflective) color would bring no additional cost. Hence the payback time for having reflective roofs is nil, and the reflective roofs save an accumulated 370kWh over 30 years of the life of the roof.

Akbari, Hashen; Rainer, Leo

2000-11-01

153

Confocal scanning microscopy under ultrashort pulse illumination  

SciTech Connect

The authors, in this paper, investigate resolution in various confocal imaging methods based on the use of an ultrashort pulsed laser beam. For bright-field confocal microscopy, time-resolved and time averaged imaging methods are considered, while resolution in two-photon and single-photon confocal fluorescence microscopy is examined. It is shown that the time-resolved approach can give a three-dimensional image of a thick object with axial resolution approximately 30% higher than the limiting value under CW laser illumination of the same wavelength as the pulsed beam, while the transverse resolution is slightly improved.

Gu, M.; Tannous, T.; Sheppard, C.J.R. [Univ. of Sydney, New South Wales (Australia). Dept. of Physical Optics

1995-12-31

154

Combined reflection and transmission microscope for telemedicine applications in field settings.  

PubMed

We demonstrate a field-portable upright and inverted microscope that can image specimens in both reflection and transmission modes. This compact and cost-effective dual-mode microscope weighs only ?135 grams (<4.8 ounces) and utilizes a simple light emitting diode (LED) to illuminate the sample of interest using a beam-splitter cube that is positioned above the object plane. This LED illumination is then partially reflected from the sample to be collected by two lenses, creating a reflection image of the specimen onto an opto-electronic sensor-array that is positioned above the beam-splitter cube. In addition to this, the illumination beam is also partially transmitted through the same specimen, which then casts lensfree in-line holograms of the same objects onto a second opto-electronic sensor-array that is positioned underneath the beam-splitter cube. By rapid digital reconstruction of the acquired lensfree holograms, transmission images (both phase and amplitude) of the same specimen are also created. We tested the performance of this field-portable microscope by imaging various micro-particles, blood smears as well as a histopathology slide corresponding to skin tissue. Being compact, light-weight and cost-effective, this combined reflection and transmission microscope might especially be useful for telemedicine applications in resource limited settings. PMID:21709875

Biener, Gabriel; Greenbaum, Alon; Isikman, Serhan O; Lee, Kelvin; Tseng, Derek; Ozcan, Aydogan

2011-08-21

155

Evaluation of general non-reflecting boundary conditions for industrial CFD applications  

NASA Astrophysics Data System (ADS)

The importance of having proper boundary conditions for the calculation domain is a known issue in Computational Fluid Dynamics (CFD). In many situations, it is very difficult to define a correct boundary condition. The flow may enter and leave the computational domain at the same time and at the same boundary. In such circumstances, it is important that numerical implementation of boundary conditions enforces certain physical constraints leading to correct results which then ensures a better convergence rate. The aim of this paper is to evaluate recently proposed non-reflecting boundary conditions (Frolov et al., 2001, Advances in Chemical Propulsion) on industrial CFD applications. Derivation of the local non-reflecting boundary conditions at the open boundary is based on finding the solution of linearized Euler equations vanishing at infinity for both incompressible and compressible formulations. This is implemented into the in-house CFD package AVL FIRE and some numerical details will be presented as well. The key applications in this paper are from automotive industry, e.g. an external car aerodynamics, an intake port, etc. The results will show benefits of using effective non-reflecting boundary conditions.

Basara, Branislav; Frolov, Sergei; Lidskii, Boris; Posvyanskii, Vladimir

2007-11-01

156

Confocal unstable-resonator semiconductor laser  

NASA Technical Reports Server (NTRS)

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

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

1986-01-01

157

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.

158

Confocal microlaparoscope for imaging the fallopian tube  

NASA Astrophysics Data System (ADS)

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

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

2012-02-01

159

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

160

Design and fabrication of reflective optical systems for space and tactical flight applications  

NASA Astrophysics Data System (ADS)

The design and fabrication of seven all-reflective optical telescopes for a range of spaceborne and tactical applications are described. These telescopes are: ZIP (Zodiacal Infrared Program), CIRRIS I and IA (Cryogenic Infrared Radiance Instrument for Shuttle), SPIRIT I and II (Spatial Infrared Rocket-borne Interferometer Telescope), CLAES (Cryogenic Limb Array Etalon Spectrometer), ASMP (Advanced Sensor Measurement Program), BMAP (Background Measurements Analysis Program), and SPIRIT III (Midcourse Space Experiment). The key design drivers are given along with the most important technical data.

Anapol, Michael I.; Mastandrea, Andrew A.

1989-10-01

161

Recent trends in total reflection X-ray fluorescence spectrometry for biological applications.  

PubMed

This review is focused on the application of total reflection X-ray fluorescence (TXRF) spectrometry in the field of biological research. In the last decade, most papers were published by authors who applied laboratory-scale TXRF equipments. The application of synchrotron radiation as excitation source (SR-TXRF) shows a slowly increasing tendency. In the cited papers the micro-, trace and multielement capability of these TXRF techniques was demonstrated in the clinical and medical laboratory practice, as well as in various plant physiological studies. For speciation of elements in biological matrices, the TXRF was used as element specific detector following an off-line separation step (e.g., thin layer chromatography, high performance liquid chromatography), however, these off-line methods are not competitive with the on-line coupled HPLC-inductively coupled plasma mass spectrometry. PMID:19110110

Szoboszlai, Norbert; Polgári, Zsófia; Mihucz, Victor G; Záray, Gyula

2009-02-01

162

Imaging of small particles using wide-field confocal microscopy  

NASA Astrophysics Data System (ADS)

Particle measurement is important in many applications such as the manufacture of drugs and paints, and aerosols. In bioimaging there is interest understanding the imaging of nanoparticles and subcellular scatterers. We present in this paper a wide field, phase measuring confocal microscope that can be used for such measurements. The wide field confocal response is obtained by illuminating both sample and reference arms of an interferometric microscope with nominally identical speckle patterns. When the speckle patterns are highly correlated the interference is significant. Contributions from out of focus planes result in uncorrelated speckle patterns and no interference. This provides a wide field confocal response. High speed measurements are enabled by parallel phase stepping using polarization optics. We have also developed a vector diffraction microscope model, using Mie theory as a scattering function, to validate the images of small particles. Correctly scaling the amplitudes of the unscattered and scattered electric fields enables co-polar transmission imaging to be modeled. Finally it is demonstrated that the phase is a more sensitive measurement of particle size than the amplitude.

Morgan, Stephen P.; Sawyer, N. B. E.; Somekh, Michael G.; See, Chung Wah; Shekunov, B. Y.; Astrakharchik, E.

2003-10-01

163

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

164

Confocal laser endomicroscopy of the colon.  

PubMed

Confocal laser endomicroscopy (CLE) has been recently proposed as a new technique that allows in vivo histologic assessment of mucosa during endoscopy. The most commonly used contrast agents are acriflavine hydrochloride and fluorescein sodium. For colon pathology assessment, the administration of fluorescein intravenously produces a strong staining of both surface epithelium and deeper layers of lamina propria. Confocal laser endomicroscopy is a feasible method to diagnose colon cancer in vivo. Furthermore, confirmation of neoplastic changes using CLE during colonoscopy may lead to major improvements in the clinical management of the patients with inflammatory bowel disease. Biopsies can be limited to targeted sampling of relevant lesions. Confocal laser endomicroscopy will certainly play an important diagnostic role during gastrointestinal endoscopy in the future, enabling the elimination of the diagnostic delay associated with conventional biopsy preparation and processing. PMID:20593059

Gheonea, Dan Ionut; Saftoiu, Adrian; Ciurea, Tudorel; Popescu, Carmen; Georgescu, Claudia Valentina; Malos, Anca

2010-06-01

165

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

PubMed Central

A recent key requirement in life sciences is the observation of biological processes in their natural in vivo context. However, imaging techniques that allow fast imaging with higher resolution in 3D thick specimens are still limited. Spinning disk confocal microscopy using a Yokogawa Confocal Scanner Unit, which offers high-speed multipoint confocal live imaging, has been found to have wide utility among cell biologists. A conventional Confocal Scanner Unit configuration, however, is not optimized for thick specimens, for which the background noise attributed to “pinhole cross-talk,” which is unintended pinhole transmission of out-of-focus light, limits overall performance in focal discrimination and reduces confocal capability. Here, we improve spinning disk confocal microscopy by eliminating pinhole cross-talk. First, the amount of pinhole cross-talk is reduced by increasing the interpinhole distance. Second, the generation of out-of-focus light is prevented by two-photon excitation that achieves selective-plane illumination. We evaluate the effect of these modifications and test the applicability to the live imaging of green fluorescent protein-expressing model animals. As demonstrated by visualizing the fine details of the 3D cell shape and submicron-size cytoskeletal structures inside animals, these strategies dramatically improve higher-resolution intravital imaging. PMID:23401517

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

2013-01-01

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

Large, durable and low?cost reflectance standard for field remote sensing applications  

Microsoft Academic Search

The development of the Canopy Pasture Probe (CAPP), for acquisition of in situ pasture canopy reflectance factor, required a suitable large reflectance standard. Spectralon has been successfully used worldwide as a reflectance standard, but large panels (greater than 20 cm diameter) suitable for use with the CAPP are very expensive. In this context, a large, durable and low cost reflectance standard

I. D. Sanches; M. P. Tuohy; M. J. Hedley; M. R. Bretherton

2009-01-01

168

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

169

[Application of near-infrared reflectance spectroscopy to the discrimination of salt tolerance of alfalfa cultivars].  

PubMed

Near infrared reflectance spectroscopy is a new developed method able to analyse the content of specific compound in the detected sample quickly and efficiently, and has been wildly used in many fields such as evaluation of nutrition value of forage, cultivar discrimination and so on. In the present paper a new method was developed for the discrimination of salt tolerance of alfalfa cultivars by Fourier transform near infrared reflectance spectroscopy. Firstly absorbance spectrum generated by Fourier transform near infrared spectrometry was used to classify twenty alfalfa cultivars. These cultivars were obviously clustered into two groups: salt tolerant and salt sensitive, similar to the result, screened by the traditional methods. Based on these results, a discrimination model was built for identification of salt tolerant cultivars. And then, six other cultivars were used to verify the function of the discriminating model. Result showed that the distinguishing rate of 100% was achieved with the performance index of 85.7%. It is concluded that Fourier transform near infrared spectrum is useful for classification and discrimination of salt tolerance of alfalfa cultivars. The method can be applied to estimate salt tolerance of alfalfa cultivars, and works more quickly and efficiently than the traditional screening methods. Application of Fourier transform near infrared spectrum to discriminating salt tolerance of alfalfa cultivars is significant in both academic and technical areas. PMID:19445209

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

2009-02-01

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

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

NASA Astrophysics Data System (ADS)

Sensing platforms based on the principle of total internal reflection (TIR) represent a fairly mature yet still expanding and exciting field of research. Sensor development has mainly been driven by the need for rapid, stand-alone, automated devices for application in the fields of clinical diagnosis and screening, food and water safety, environmental monitoring, and chemical and biological warfare agent detection. The technologies highlighted in this chapter are continually evolving, taking advantage of emerging advances in microfabrication, lab-on-a-chip, excitation, and detection techniques. This chapter describes many of the underlying principles of TIR-based sensing platforms and additionally focusses on planar TIR fluorescence (TIRF)-based chemical and biological sensors.

Sapsford, Kim E.

172

Spectral reflectance and emittance of particulate materials. I - Theory. II - Application and results  

NASA Technical Reports Server (NTRS)

The sizes, shapes, and complex refractive indices of particles are calculated in a study of the IR spectral reflectance of a semiinfinite medium composed of irregular particles of different materials. Geometric optics techniques with corrections for additional absorption due to particle edges and asperities is used in scattering and absorption calculations for particles larger than the wavelength. A Lorentz-Lorenz model is used to derive the averaged complex index of the medium, assuming that its individual particles are ellipsoids. Experimental results obtained on a Michelson interferometer for the spectral emittance of particulate mineral materials are compared with theoretical results. Good agreement between the experimental and theoretical results suggests the applicability, in remote IR spectroscopy, of the theoretical concepts applied in this study.

Emslie, A. G.; Aronson, J. R.

1973-01-01

173

[Application of Fourier transform attenuated total reflection infrared spectroscopy in analysis of pulp and paper industry].  

PubMed

As one of the most powerful tools to investigate the compositions of raw materials and the property of pulp and paper, infrared spectroscopy has played an important role in pulp and paper industry. However, the traditional transmission infrared spectroscopy has not met the requirements of the producing processes because of its disadvantages of time consuming and sample destruction. New technique would be needed to be found. Fourier transform attenuated total reflection infrared spectroscopy (ATR-FTIR) is an advanced spectroscopic tool for nondestructive evaluation and could rapidly, accurately estimate the production properties of each process in pulp and paper industry. The present review describes the application of ATR-FTIR in analysis of pulp and paper industry. The analysis processes will include: pulping, papermaking, environmental protecting, special processing and paper identifying. PMID:21595211

Zhang, Yong; Cao, Chun-yu; Feng, Wen-ying; Xu, Ming; Su, Zhen-hua; Liu, Xiao-meng; Lü, Wei-jun

2011-03-01

174

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

175

Some analytical approximations to radiative transfer theory and their application for the analysis of reflectance data  

NASA Astrophysics Data System (ADS)

We derive an analytical approximation in the framework of the radiative transfer theory for use in the analysis of diffuse reflectance measurements. This model uses two parameters to describe a material, the transport free path length, l, and the similarity parameter, s. Using a simple algebraic expression, s and l can be applied for the determination of the absorption coefficient Kabs, which can be easily compared to absorption coefficients measured using transmission spectroscopy. l and Kabs can be seen as equivalent to the S and K parameters, respectively, in the Kubelka-Munk formulation. The advantage of our approximation is a clear basis in the complete radiative transfer theory. We demonstrate the application of our model to a range of different paper types and to fabrics treated with known levels of a dye.

Kokhanovsky, Alexander; Hopkinson, Ian

2008-03-01

176

Applications Of Reflective High-Speed Photography In Research Of Welding Molten Pools  

NASA Astrophysics Data System (ADS)

By making comparison between a few types of light sources, a removable and adjustable xenon light source had been successfully trial-produced to take clear photos of welding arc, metal transfer and molten pools. In the procession of investigating the technology of reflective high-speed photography, some problems for taking photos of welding arc, solidification of molten metal, especially the molten pools have been solved. This method has put into use in some research subjects and practical applications, such as "Welding Mechanism Research with Quartz-backing". "Comparison of Electrode Properties for Vertical-downwards Welding", and "Welder's Pressure Vessel-Welding Operating Demonstration", etc. the results were satisfactory and were praised by the profession of welding in China.

Xiaomin, Gu; Yuiiong, Ma

1989-06-01

177

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

178

Statistical characterization of engineered tissues using confocal mosaic technology  

NASA Astrophysics Data System (ADS)

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

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

2010-02-01

179

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 ...

180

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

181

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

National Technical Information Service (NTIS)

Mar Vel Black is a revolutionary new extremely low reflectivity anodized coating developed by Martin Marietta of Denver. It is of great interest in optics in general, and in star trackers specifically because it can reduce extraneous light reflections. A ...

E. Yung

1974-01-01

182

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.

183

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 (Villanañe, Basque Country, Spain). In all cases, in situ measurements were carried out and also a few samples were collected and measured in the laboratory by diffuse reflectance spectroscopy (DRIFT) in order to validate the information obtained by the handheld instrument. In the analyses performed in situ, distortions in the diffuse reflectance spectra can be observed due to the presence of specular reflection, showing the inverted bands caused by the Reststrahlen effect, in particular on those IR bands with the highest absorption coefficients. This paper concludes that the results obtained in situ by a diffuse reflectance handheld device are comparable to those obtained with laboratory diffuse reflectance spectroscopy equipment and proposes a few guidelines to acquire good spectra in the field, minimising the influence caused by the specular reflection.

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

2014-08-01

184

Application of wavelet transform on hyperspectral reflectance for soybean lai estimation in the songnen plain, China  

Microsoft Academic Search

In this study, we present spectral measurements of soybean LAI and their estimation from reflectance spectra data in Songnen Plain. Soybean canopy reflectance and its derivative were subsequently used in a linear regression analysis against LAI on one by one spectral reflectance. It was found that determination coefficient for LAI was high in blue, red and near infrared spectral region,

Dongmei Lu; Kaishan Song; Zongming Wang; Jia Du; Lihong Zeng; Xiaochun Lei

2010-01-01

185

Characterizing tissue optical properties using confocal and low-coherence imaging  

NASA Astrophysics Data System (ADS)

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 (g) is presented. Experimental measurements on 5 tissue types from mice (white and gray matter of brain, skin, liver, muscle) as well as 0.1-um-dia. polystyrene microspheres are presented. The tissues have similar mu_s values (about 500 [1/cm]) but variable g values (0.8-0.99). Anisotropy appears to be the primary mechanism of contrast for confocal measurements such as reflectance-mode confocal scanning laser microscopy (rCLSM) and optical coherence tomography (OCT). While fluorescence imaging depends on fluorophores, and absorption imaging depends on chromophores, the results of this study suggest that contrast of confocal imaging of biological tissues depends primarily on anisotropy.

Jacques, Steven L.; Gareau, Daniel S.

2006-02-01

186

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

PubMed Central

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

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

2013-01-01

187

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

188

Application of X-ray reflection interface microscopy to thin-film materials  

Microsoft Academic Search

New X-ray imaging techniques with excellent spatial resolution are under development for investigating surface and interface structures. X-ray reflection imaging microscopy (XRIM) applies full-field imaging to a specularly reflected X-ray beam from a surface or interface. This technique uses a zone plate objective lens to spatially resolve the reflected X-ray intensity and, by exploiting phase contrast, allows steps or terraces

Zhan Zhang; Paul Zschack; Paul Fenter

2011-01-01

189

Analysis of IBAD silicon oxynitride film for anti-reflection coating application  

Microsoft Academic Search

A SOI-based optoelectronic device needs a high-quality anti-reflection coating on both faces of the device to minimize the optical reflectance from the face. In this work amorphous silicon oxynitride films were deposited on silicon substrates by ion beam assisted deposition (IBAD). The main purpose was to use silicon oxynitride film as single layer anti-reflection coating for SOI-based optoelectronic devices. This

Yongjin Wang; Xinli Cheng; Zhilang Lin; Changsheng Zhang; Haibo Xiao; Feng Zhang; Shichang Zou

2004-01-01

190

Confocal fluorescence microscopy of living cells  

NASA Astrophysics Data System (ADS)

We present here the study of intracellular distribution of doxorubicin in the single living cell by scanning confocal fluorescence microscopy, with argon laser excitation and photon counting detection. New results on the nuclear and cytoplasmic drug fluorescence not detectable by conventional microscopy are discussed. Differences in the fluorescence pattern observed in living and fixed cells suggest new insights in the mode of action of the drug.

Doglia, Silvia M.; Bianchi, L.; Colombo, Roberto; Allam, N.; Morjani, Hamid; Manfait, Michel; Villa, A. M.

1993-06-01

191

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

192

Application of Internal Reflectance Spectroscopy to the Study of Solid Propellants: I. Composite and Double Base Propellants  

Microsoft Academic Search

It is shown that by using Internal Reflectance Spectroscopy the infrared spectra of solid propellants can be obtained with the expenditure of a minimum effort in sample preparation. Applications of this technique as a quality control technique and a method of studying surface charring are discussed.

G. E. SALSER; L. DAUERMAN

1972-01-01

193

Fibered confocal spectroscopy and multicolor imaging system for in vivo fluorescence analysis  

NASA Astrophysics Data System (ADS)

We report the design and implementation of spectroscopic and multicolor imaging capabilities into a fibered confocal fluorescence microscope (FCFM) already capable of in vivo imaging. The real time imaging device and the high resolution fiber probe make this system the first reported capable of performing multi color detection in the field of FCFM. The advantages of the system will allow in vivo morphological and functional imaging. Preliminary experiments were carried out in tissue samples to demonstrate the potential of the technique. The quality of the axial sectioning achieved in the confocal fluorescence spectroscopy mode is demonstrated experimentally, and applications to multicolor imaging are shown.

Jean, Florence; Bourg-Heckly, Genevieve; Viellerobe, Bertrand

2007-04-01

194

Real-time evaluation of aggregation using confocal imaging and image analysis tools.  

PubMed

Real-time confocal imaging was utilised to monitor the in situ loss of BSA monomers and aggregate formation using Spatial Intensity Distribution Analysis (SpIDA) and Raster Image Correlation Spectroscopy (RICS). At the proof of concept level this work has demonstrated the applicability of RICS and SpIDA for monitoring protein oligomerisation and larger aggregate formation. PMID:24324999

Hamrang, Zahra; Zindy, Egor; Clarke, David; Pluen, Alain

2014-02-01

195

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

Microsoft Academic Search

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

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

2004-01-01

196

Optical Sectioning and Confocal Imaging and Analysis in the Transmission Electron Microscope  

NASA Astrophysics Data System (ADS)

Aberration correction in the transmission electron microscope has led to a reduction in the depth of focus for imaging. The depth of focus in a state-of-the-art scanning transmission electron microscope system, which is currently just a few nanometers, creates an opportunity to explore the three-dimensional structure of a sample by focusing on specific layers, an approach known as optical sectioning. In this article, we review the performance of optical sectioning in the scanning transmission electron microscope. Limitations in the simple optical sectioning approach are used to motivate discussion of confocal electron microscopy. Three imaging modes in scanning confocal electron microscopy have been investigated both theoretically and experimentally, and are reviewed here. The method of implementing a confocal arrangement in a microscope is discussed, along with its comparative performance with other methods for three-dimensional imaging and analysis. Finally, current and future potential applications are discussed.

Nellist, Peter D.; Wang, Peng

2012-08-01

197

Design and Demonstration of a Miniature Catheter for a Confocal Microendoscope  

NASA Astrophysics Data System (ADS)

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

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

2004-11-01

198

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

PubMed Central

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

Hng, Keng Imm; Dormann, Dirk

2013-01-01

199

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

200

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

201

Wet-Developable Organic Anti-Reflective Coatings For Implant Layer Applications  

Microsoft Academic Search

Bottom anti-reflective coatings (BARCs) have been widely used in conjunction with photoresists in the manufacture of semiconductors during the photolithography step of the process. The primary benefits of BARCs in photolithography are focus\\/exposure latitude improvement, enhanced critical dimension (CD) control, elimination of reflective notching, and protection of DUV resist from substrate poisoning. In the past, BARCs have mainly been used

Xie Shao; Alice Guerrero; Yiming Gu

202

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

NASA Technical Reports Server (NTRS)

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

Pepper, Stephen V.

1995-01-01

203

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

204

Detection of basal cell carcinomas in Mohs excisions with fluorescence confocal mosaicing microscopy  

PubMed Central

BACKGROUND: High-resolution real-time imaging of human skin is possible with a confocal microscope either in vivo or in freshly excised tissue ex vivo. Nuclear and cellular morphology is observed in thin optical sections, similar to that in conventional histology. Contrast agents such as acridine orange in fluorescence and acetic acid in reflectance have been used in ex vivo imaging to enhance nuclear contrast. OBJECTIVE: To evaluate the sensitivity and specificity of ex vivo real-time imaging with fluorescence confocal mosaicing microscopy, using acridine orange, for the detection of residual basal cell carcinoma (BCC) in Mohs fresh tissue excisions. METHODS: Forty-eight discarded skin excisions were collected following completion of Mohs surgery, consisting of excisions with and without residual BCC of all major subtypes. The tissue was stained with acridine orange and imaged with a fluorescent confocal mosaicing microscope. Confocal mosaics were matched to the corresponding H&E stained Mohs frozen sections. Each mosaic was divided into subsections, resulting in 149 sub-mosaics for study. Two Mohs surgeons, who were blinded to the cases, independently assessed confocal sub-mosaics and recorded the presence or absence of BCC, location, and histologic subtype(s). Assessment of confocal mosaics was compared to corresponding Mohs surgery maps. RESULTS: The overall sensitivity and specificity of detecting residual BCC was 96.6% and 89.2%, respectively. The positive predictive value was 92.3% and the negative predictive value 94.7%. Very good correlation was observed between confocal mosaics and matched Mohs frozen sections for benign and malignant skin structures, overall tumor burden and location, and identification of all major histologic subtypes of BCC. CONCLUSIONS: Fluorescent confocal mosaicing microscopy using acridine orange enables detection of residual BCC of all subtypes in Mohs fresh tissue excisions with high accuracy. This observation is an important step towards the long-term clinical goal of using a non-invasive imaging modality for potential real-time surgical pathology-at-the-bedside for skin and other tissues. PMID:19416248

Karen, JK; Gareau, DS; Dusza, SW; Tudisco, M; Rajadhyaksha, M; Nehal, KS

2009-01-01

205

An automated approach to analyze microstructural remodeling from confocal microscopies of ventricular myocytes from diseased hearts  

PubMed Central

Various types of heart disease are associated with structural remodeling of cardiac cells. In this work, we present a software framework for automated analyses of structures and protein distributions involved in excitation-contraction coupling in cardiac muscle cells (myocytes). The software framework was designed for processing sets of three-dimensional image stacks, which were created by fluorescent labeling and scanning confocal microscopy of ventricular myocytes from a rabbit infarction model. Design of the software framework reflected the large data volume of image stacks and their large number by selection of efficient and automated methods of digital image processing. Specifically, we selected methods with small user interaction and automated parameter identification by analysis of image stacks. We applied the software framework to exemplary data yielding quantitative information on the arrangement of cell membrane (sarcolemma), the density of ryanodine receptor clusters and their distance to the sarcolemma. We suggest that the presented software framework can be used to automatically quantify various aspects of cellular remodeling, which will provide insights in basic mechanisms of heart diseases and their modeling using computational approaches. Further applications of the developed approaches include clinical cardiological diagnosis and therapy planning. PMID:22944798

Wulfers, E. M.; Torres, N. S.; Lenis, G.; Li, H.; Seemann, G.; Dossel, O.; Bridge, J. H. B.; Sachse, F. B.

2012-01-01

206

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

NASA Astrophysics Data System (ADS)

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

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

2010-12-01

207

Rapid Screening of Cancer Margins in Tissue with Multimodal Confocal Microscopy  

PubMed Central

Background Complete and accurate excision of cancer is guided by the examination of histopathology. However, preparation of histopathology is labor intensive and slow, leading to insufficient sampling of tissue and incomplete and/or inaccurate excision of margins. We demonstrate the potential utility of multimodal confocal mosaicing microscopy for rapid screening of cancer margins, directly in fresh surgical excisions, without the need for conventional embedding, sectioning or processing. Materials/Methods A multimodal confocal mosaicing microscope was developed to image basal cell carcinoma margins in surgical skin excisions, with resolution that shows nuclear detail. Multimodal contrast is with fluorescence for imaging nuclei and reflectance for cellular cytoplasm and dermal collagen. Thirtyfive excisions of basal cell carcinomas from Mohs surgery were imaged, and the mosaics analyzed by comparison to the corresponding frozen pathology. Results Confocal mosaics are produced in about 9 minutes, displaying tissue in fields-of-view of 12 mm with 2X magnification. A digital staining algorithm transforms black and white contrast to purple and pink, which simulates the appearance of standard histopathology. Mosaicing enables rapid digital screening, which mimics the examination of histopathology. Conclusions Multimodal confocal mosaicing microscopy offers a technology platform to potentially enable real-time pathology at the bedside. The imaging may serve as an adjunct to conventional histopathology, to expedite screening of margins and guide surgery toward more complete and accurate excision of cancer. PMID:22721570

Gareau, Daniel S.; Jeon, Hana; Nehal, Kishwer S.; Rajadhyaksha, Milind

2012-01-01

208

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

PubMed

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

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

2013-12-15

209

Nondestructive Sectioning Of Fixed And Living Specimens Using A Confocal Scanning Laser Fluorescence Microscope: Microtomoscopy  

NASA Astrophysics Data System (ADS)

Modern molecular biologists and in particular cell biologists have a large set of experimental tools at their disposal. Immunocytochemistry, fluorescence labels, and microscopy are only subsets of the entire spectrum of methods. Depending on the fields in which biologists work a lot of results are obtained with classical biochemistry, gel electrophoresis and blotting techniques. Gathering morphological data may not be the least important task, but will in many cases be considered only after all other methods have failed. With the advent of video microscopes and the availability of high speed image processing devices, microscopy can also be used for quantitation. Confocal scanning laser fluorescence microscopy (Ft-CSCM) [Cox 1984] is in fact another technique or method that is entering the rapidly developing field of quantitative microscopy. It is therefore very important to understand the physical properties of the CSCLM in detail and to compare a confocal microscope not only with other confocal microscopes, but also with all the other techniques and methods. The confocal microscope has to find its particular application and it should be understood that it will replace neither conventional microscopy, nor video microscopy, nor electron microscopy. It will not be used for every application and every type of investigation. The CSCM has to find its niche in the laboratories and this paper will present two applications in which it proves its usefulness.

Stelzer, Ernst H...; Wijnaendts-Van-Resandt, Roelof W.

1987-08-01

210

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

Microsoft Academic Search

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

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

2001-01-01

211

Application of Soil and Vegetation Reflectance Spectra to Color and Color Infrared Photography,  

National Technical Information Service (NTIS)

Characterizing arid region soil and vegetation conditions from remotely sensed imagery can be limited by the small image tonal contrast between soil vegetation surfaces. Ground-level reflectance spectra of different soil surfaces can be highly variable ov...

J. P. Henley, M. B. Satterwhite

1987-01-01

212

Polarization modulation infrared reflection absorption spectroscopy for heterogeneous catalytic applications at elevated pressures  

E-print Network

and temperatures higher than room temperature). Thus, some of the few detailed examples of the polarization modulation infrared reflection absorption spectroscopy (PM-IRAS) as an in situ vibrational spectroscopic tool for the elevated-pressure investigation of gas...

Ozensoy, Emrah

2005-08-29

213

Light reflection at polyaniline films and its application to a kinetic study of polymer chain conformation  

Microsoft Academic Search

Light reflection at polymer-coated electrodes is studied for polyaniline, poly(o-methylaniline), and poly(o-methoxyaniline). Reflected light intensity is found to be affected greatly by the applied potential for the two reasons: one is absorption of light due to coloring of the oxidized polymer film and the other is light scattering which is concerned with a polymer chain conformation upon oxidation. A new

Yutaka Harima; Kazuya Kishimoto; Haruo Mizota

2007-01-01

214

Diffusion of photoacid generators by laser scanning confocal microscopy  

NASA Astrophysics Data System (ADS)

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

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

1998-06-01

215

Detection limits of confocal surface plasmon microscopy  

PubMed Central

This paper applies rigorous diffraction theory to evaluate the minimum mass sensitivity of a confocal optical microscope designed to excite and detect surface plasmons operating on a planar metallic substrate. The diffraction model is compared with an intuitive ray picture which gives remarkably similar predictions. The combination of focusing the surface plasmons and accurate phase measurement mean that under favorable but achievable conditions detection of small numbers of molecules is possible, however, we argue that reliable detection of single molecules will benefit from the use of structured surfaces. System configurations needed to optimize performance are discussed. PMID:24940537

Pechprasarn, Suejit; Somekh, Michael G.

2014-01-01

216

Detection limits of confocal surface plasmon microscopy.  

PubMed

This paper applies rigorous diffraction theory to evaluate the minimum mass sensitivity of a confocal optical microscope designed to excite and detect surface plasmons operating on a planar metallic substrate. The diffraction model is compared with an intuitive ray picture which gives remarkably similar predictions. The combination of focusing the surface plasmons and accurate phase measurement mean that under favorable but achievable conditions detection of small numbers of molecules is possible, however, we argue that reliable detection of single molecules will benefit from the use of structured surfaces. System configurations needed to optimize performance are discussed. PMID:24940537

Pechprasarn, Suejit; Somekh, Michael G

2014-06-01

217

Multimodal confocal mosaicing of basal cell carcinomas in Mohs surgical skin excisions  

NASA Astrophysics Data System (ADS)

Mohs surgery is a procedure for microscopically excising basal cell carcinomas (BCCs) while preserving maximal surrounding normal skin. Each serial excision is guided by examination of the frozen histology of the previous excision. Because several (2-20) excisions must be made and frozen histology prepared for each excision. Mohs surgery is time-consuming (15-45 minutes per excision) and tedious. Real-time confocal reflectance mosaicing enables detection of BCCs directly in fresh excisions, following contrast-enhancement by acetowhitening. A confocal mosaic allows rapid observation of 15x15 mm2 of tissue, which is equivalent to a low magnification, 2X view of the excision. Relatively large superficial nodular and micronodular BCCs are rapidly detectable in confocal reflectance mosaics, whereas detection of much smaller infiltrative and sclerosing BCCs is a challenge due to the lack of sufficient nuclear/dermis contrast in acetowhitened excisions. Multimodal contrast, combining reflectance with either fluorescence or autofluorescence may make it possible to detect infiltrative and sclerosing BCCs. A reflectance image shows both nuclei and the surrounding dermis, whereas an autofluorescence image (excitation at 488nm, detection 500-700nm) shows only the dermis. Thus, ability of a composite (i.e., reflectance-less-autofluorescence) image shows significantly darkened dermis, with stronger enhancement of nuclear/dermis contrast. Preliminary results illustrate that this may enable detection of infiltrative and sclerosing BCCs. The use of reflectance and autofluorescence parallels the use of two stains (hematoxylin and eosin) in histology, thus allowing a more complete optical detection method.

Gareau, Daniel S.; Patel, Yogesh G.; Li, Yongbiao; Nehal, Kishwer S.; Huang, Billy; Rajadhyaksha, Milind

2007-02-01

218

Inter-Comparison of ASTER and MODIS Surface Reflectance and Vegetation Index Products for Synergistic Applications to Natural Resource Monitoring  

PubMed Central

Synergistic applications of multi-resolution satellite data have been of a great interest among user communities for the development of an improved and more effective operational monitoring system of natural resources, including vegetation and soil. In this study, we conducted an inter-comparison of two remote sensing products, namely, visible/near-infrared surface reflectances and spectral vegetation indices (VIs), from the high resolution Advanced Thermal Emission and Reflection Radiometer (ASTER) (15 m) and lower resolution Moderate Resolution Imaging Spectroradiometer (MODIS) (250 m – 500 m) sensors onboard the Terra platform. Our analysis was aimed at understanding the degree of radiometric compatibility between the two sensors' products due to sensor spectral bandpasses and product generation algorithms. Multiple pairs of ASTER and MODIS standard surface reflectance products were obtained at randomly-selected, globally-distributed locations, from which two types of VIs were computed: the normalized difference vegetation index and the enhanced vegetation indices with and without a blue band. Our results showed that these surface reflectance products and the derived VIs compared well between the two sensors at a global scale, but subject to systematic differences, of which magnitudes varied among scene pairs. An independent assessment of the accuracy of ASTER and MODIS standard products, in which “in-house” surface reflectances were obtained using in situ Aeronet atmospheric data for comparison, suggested that the performance of the ASTER atmospheric correction algorithm may be variable, reducing overall quality of its standard reflectance product. Atmospheric aerosols, which were not corrected for in the ASTER algorithm, were found not to impact the quality of the derived reflectances. Further investigation is needed to identify the sources of inconsistent atmospheric correction results associated with the ASTER algorithm, including additional quality assessments of the ASTER and MODIS products with other atmospheric radiative transfer codes.

Miura, Tomoaki; Yoshioka, Hiroki; Fujiwara, Kayo; Yamamoto, Hirokazu

2008-01-01

219

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

220

Metrological characterization of optical confocal sensors measurements (20 and 350 travel ranges)  

NASA Astrophysics Data System (ADS)

Confocal sensors are usually used in dimensional metrology applications, like roughness, form, thickness and surface profile measurements. With the progress of technologies, metrological applications require measurements with nanometer-level of accuracy by using ultra-high precision machines, which should present a minimum and stable metrology loop. The loop is equipped with sensors with nanometer-level of resolution and linear residual. The study presented here, is mainly focused on the characterization of Confocal sensors in order to identify their performance practically. Such information is useful to establish a correction model in the digital signal processing (DSP) software. In this context, LNE developed an ultra-high-precision machine, dedicated to the roughness measurement with an uncertainty of a few nanometres (< 30 nm) by using a tactile sensor. In order to match this machine to Confocal sensors, an experiment has been recently developed to characterize the behaviour of two commercial Confocal sensors with the measuring range of 20 ?m and 350 ? m. The experiment permits the evaluation of the major error sources: axial and radial motion errors as-well-as the deviation/tilt of the sensors.

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

2014-03-01

221

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

NASA Astrophysics Data System (ADS)

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

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

1993-04-01

222

Confocal Raman imaging for cancer cell classification  

NASA Astrophysics Data System (ADS)

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

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

2014-05-01

223

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.

224

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

PubMed

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

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

2005-10-01

225

Appearance Measurements in Industry and their Application in Light Reflection Models  

E-print Network

. The appearance industry professionals have tried to determine the Also with Faculty of Mathematics, Physics.1 Goniochromatic Paints The color of an opaque dielectric is typically mod- eled with Lambertian reflectance that is the color is considered constant with respect to the view- ing angle. However, the goniochromatic materi

Durikovic, Roman

226

Application of GIS for processing and establishing the correlation between weather radar reflectivity and precipitation data  

Microsoft Academic Search

Correlation between weather radar reflectivity and precipitation data collected by rain gauges allows empirical formulae to be obtained that can be used to create continuous rainfall surfaces from discrete data. Such surfaces are useful in distributed hydrologic modelling and early warning systems in flood management. Because of the spatial relationship between rain gauge locations and radar coverage area, GIS provides

Y. Gorokhovich; G. Villarini

2005-01-01

227

A microfabricated scanning confocal optical microscope for in situ imaging  

NASA Astrophysics Data System (ADS)

Scanning confocal optical microscopes are well suited for imaging living tissue because of their ability to 'cross section' intact tissue. They are not, however, well suited for imaging tissues in situ. This dissertation describes a new, miniature, mirror scanned, high resolution confocal optical microscope that operates in real time. It is small enough to fit into an endoscope, and may eventually be incorporated into a hypodermic needle. Such a device would provide immediate in-situ tissue assessment at the cellular level and may enable, for example, biopsy without tissue removal. Non-medical applications may include process monitoring and endoscopic inspection. The microfabricated confocal optical scanning microscope, or ?COSM, incorporates single mode optical fiber illumination, silicon torsional scan mirrors, and an off- axis micro diffractive lens. The prototype device is monochromatic, at 633 nm, with a 1.1 mm working distance and 0.25 NA. It achieves a line response of 0.98 ?m FWHM, and an axial response of 11.1 ?m FWHM. The first part of the dissertation describes the opto- mechanical design of the microscope, which was chosen to be compatible with the microfabrication technologies used for its construction. Then the imaging properties of the off-axis diffractive objective lens are developed, including the aberrations of second and third order which constrain its use. The lens is a surface relief phase grating, and a rigorous electromagnetic analysis is employed to specify the pupil function of the microscope. Then the image forming properties of the ?COSM are derived and compared to experimental results. The second part of the dissertation describes the fabrication of the individual elements of the ?COSM, and their assembly into an imaging instrument. The lens is constructed using electron beam lithography and reactive ion etching of a fused silica substrate. The scanning mirrors for the microscope, which comprise a single crystal silicon plate suspended by silicon nitride hinges, are constructed using wafer bonding and surface micromachining techniques. A spacer element is fabricated using bulk silicon micromachining. A package is described which places the ?COSM imaging head, complete with focus control, inside a 3.4 mm OD hypodermic tube. Sample images acquired with the microscope are presented.

Dickensheets, David Lee

228

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

2011-01-01

229

Near Real Time Confocal Microscopy of Cultured Amelanotic Cells: Sources of Signal, Contrast Agents and Limits of Contrast  

NASA Astrophysics Data System (ADS)

The use of high resolution, in vivo confocal imaging for noninvasive assessment of tissue pathology may offer a clinically important adjunct to standard histopathological techniques. To augment the present understanding of both the capabilities and limitations of in vivo confocal imaging, we investigated cellular sources of image contrast in amelanotic tissues, how contrast can be enhanced with external agents and how contrast is degraded by the scattering of overlying cells. A high-resolution reflected light confocal microscope was constructed and used to obtain images of various types of unstained amelanotic cells in suspension in real time before and after the addition of contrast agents. Reflectance images were compared to phase contrast images and electron micrographs to identify morphology visible with real time reflected light confocal microscopy. Mechanisms which decrease image contrast, including interference effects and scattering in overlying layers of cells, were considered. In amelanotic epithelial cells, fluctuations in the nuclear index of refraction provide signal which can be imaged even under several overlying cell layers. Acetic acid is an external contrast agent which can enhance this nuclear backscattering. Image contrast is degraded by the presence of multiple scattering in overlying cell layers. The degradation of image contrast by cell scattering depends on the scattering phase function; in vitro models which use polystyrene microspheres to approximate tissue underestimate the actual degradation caused by cell scattering. The loss in contrast can be explained using a finite difference time domain model of cellular scattering. We conclude that near real time reflected light confocal microscopy can be used to study cell morphology in vivo. Contrast degradation due to overlying tissue is a concern and cannot adequately be modeled using conventional tissue phantoms; however, acetic acid may be used to substantially increase intrinsic contrast, allowing imaging at significant depths despite distortion from overlying layers.

Smithpeter, Colin L.; Dunn, Andrew; Drezek, Rebekah; Collier, Tom; Richards-Kortum, Rebecca R.

1998-10-01

230

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

231

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

232

Application of reflectance anisotropy spectroscopy to laser diode growth in MOVPE  

NASA Astrophysics Data System (ADS)

The growth of layer structures for visible and near-infrared laser diodes is investigated in metal-organic vapour phase epitaxy (MOVPE) under production-like conditions using reflectance anisotropy spectroscopy (RAS). For this purpose the dependence of the reflectance anisotropy (RA) signal on doping type and level is studied for AlGaAs and AlGaInP. The growth of complete layer structures can then be fingerprinted by the significant features of the RA spectra. The reproducibility of the growth process is controlled using the RA transients taken with a high time resolution at a fixed photon energy. Additionally, the emission wavelength of a GaAsP quantum well (QW) can be correlated to the RA level during QW growth. Information about buried interfaces can also be gained from the RA transients as demonstrated for AlGaInP laser structures.

Zorn, M.; Weyers, M.

2005-03-01

233

Polarization Effects in Reflecting Coronagraphs for White Light Applications in Astronomy  

E-print Network

The properties of metal thin films have been largely overlooked in discussions of the technical limitations and problems that arise in the field of direct detection of exoplanets. Here, polarization properties and anisotropy properties of highly reflecting thin metal films are examined within the context of the requirements for the ultra-low scattered-light system performance of coronagraphs applied to space and ground-based high-contrast, white-light astronomy. Wavelength-dependent optical constants for highly reflecting thin metal films, taken from the literature are used to calculate the polarization-dependent transmissivity of a typical coronagraph. The effects of degraded performance on the astronomical science are examined. Suggestions are made for future work.

James B. Breckinridge; Ben R. Oppenheimer

2003-09-15

234

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

235

Application of a differential reflectivity technique to the EDOP radar in ground-based operation  

Microsoft Academic Search

This paper discusses the modification of a single-frequency Doppler radar (9.6 GHz) to accommodate dual-frequency operation for the study of the microphysical character of precipitation. The modification involves the ER-2 Doppler radar (EDOP), an airborne, meteorological research radar of the NASA\\/Goddard Space Flight Center. Radar operation is modified to provide reflectivity signals at two distinct frequencies at 9% separation. Differential

S. W. Bidwell; R. Meneghini; L. Liao; R. F. Rincon; G. M. Heymsfield

2000-01-01

236

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

237

Application of total internal reflection microscopy for laser damage studies on fused silica  

SciTech Connect

Damage studies show that the majority of damage on ultraviolet grade fused silica initiates at the front or rear surface. The grinding and polishing processes used to produce the optical surfaces of transparent optics play a key role in the development of defects which can ultimately initiate damage. These defects can be on or breaking through the surface or can be sub-surface damage. Total Internal Reflection Microscopy has been documented as a tool for revealing both sub-surface and surface defects in transparent materials. Images taken which compare both Total Internal Reflection Microscopy and Atomic Force Microscopy show that the observed defects can be less than one micron in size. Total Internal Reflection Microscopy has the added benefit of being able to observe large areas (1 square millimeter) with sub-micron detection. Both off-line and in-situ systems have been applied in the Lawrence Livermore National Laboratory`s damage laboratory in order to understand defects in the surface and subsurface of polished fused silica. There is a preliminary indication that TIRM quality can be related to the damage resistance. The in-situ microscope is coupled into a 355 run, 7.5 ns, 10 Hz Nd:YAG laser system in order to study damage occurring at localized scatter sites revealed with the Total Internal Reflection Microscopy method. The tests indicate damage initiating at observed artifacts which have many different morphologies and damage behaviors. Some of the scatter sites and damage morphologies revealed have been related back to the finishing process.

Sheehan, L. M., LLNL

1997-12-01

238

Separating a Color Signal into Illumination and Surface Reflectance Components: Theory and Applications  

Microsoft Academic Search

A separation algorithm for achieving color constancy and theorems concerning its accuracy are presented. The algorithm requires extra information, over and above the usual three values mapping human cone responses, from the optical system. However, with this additional information-specifically, a sampling across the visible range of the reflected, color-signal spectrum impinging on the optical sensor-the authors are able to separate

Jian Ho; Brian V. Funt; Mark S. Drew

1990-01-01

239

Scratch-resistant zeolite anti-reflective coating on glass for solar applications  

Microsoft Academic Search

Sol-gel SiO2 anti-reflection (AR) coating on solar glass is known to increase the current output by a few percent, but its mechanical durability is of concern. To improve its strength, the amorphous SiO2 may be replaced by zeolite, which is a microporous aluminosilicate crystalline material. Scratch-resistant AR coating has been prepared by the dip coating of a composition which contains

Chien-Hung Chen; Shiao-Yi Li; Anthony S. T. Chiang; Albert T. Wu; Y. S. Sun

2011-01-01

240

Composite medium with silver nanoparticles for anti-reflection coating application  

Microsoft Academic Search

This research presents a design of simple interference anti-reflection coating consisting of a transparent host and uniformly oriented disc-like silver nanoparticles. This work explores the utility of effective medium representations to simplify the electromagnetic analysis of composite system, and demonstrates the use of this simplification in solving of the boundary problem under consideration. With the help of full-wave finite-element numerical

S. G. Moiseev; S. V. Vinogradov; A. A. Kulikov

2010-01-01

241

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

242

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-Santibanez, Gabriel; Cho, Kae Won; Lumeng, Carey N.

2014-01-01

243

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

244

In vivo integrated photoacoustic and confocal microscopy of hemoglobin  

E-print Network

and tumor growth. The oxygen partial pressure, pO2, is proportional to dissolved oxygen concentrationIn vivo integrated photoacoustic and confocal microscopy of hemoglobin oxygen saturation and oxygen) and fluorescence confocal microscopy (FCM) to noninvasively image hemoglobin oxygen saturation (sO2) and oxygen

Wang, Lihong

245

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

246

Confocal Fabry-Perot interferometer based high spectral resolution lidar  

NASA Astrophysics Data System (ADS)

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

Hoffman, David Swick

247

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

248

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

249

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

250

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

Microsoft Academic Search

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 KNbO3 was demonstrated, yielding 1.8 mW at 490 nm with a near diffraction

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

2008-01-01

251

In Vivo Confocal Microscopy in Scarring Trachoma  

PubMed Central

Objective To characterize the tissue and cellular changes found in trachomatous scarring (TS) and inflammation using in vivo confocal microscopy (IVCM). Design Two complimentary case-control studies. Participants The first study included 363 cases with TS (without trichiasis), of whom 328 had IVCM assessment, and 363 control subjects, of whom 319 had IVCM assessment. The second study included 34 cases with trachomatous trichiasis (TT), of whom 28 had IVCM assessment, and 33 control subjects, of whom 26 had IVCM assessment. Methods All participants were examined with ×2.5 loupes. The IVCM examination of the upper tarsal conjunctiva was carried out with a Heidelberg Retina Tomograph 3 with the Rostock Cornea Module (Heidelberg Engineering GmbH, Dossenheim, Germany). Main Outcome Measures The IVCM images were graded in a masked manner using a previously published grading system evaluating the inflammatory infiltrate density; the presence or absence of dendritiform cells (DCs), tissue edema, and papillae; and the level of subepithelial connective tissue organization. Results Subjects with clinical scarring had a characteristic appearance on IVCM of well-defined bands and sheets of scar tissue visible. Similar changes were also seen in some clinically normal subjects consistent with subclinical scarring. Scarred subjects had more DCs and an elevated inflammatory infiltrate, even after adjusting for other factors, including the level of clinical inflammation. Cellular activity was usually seen only in or just below the epithelium, rarely being seen deeper than 30 ?m from the surface. The presence of tissue edema was strongly associated with the level of clinical inflammation. Conclusions In vivo confocal microscopy can be quantitatively used to study inflammatory and scarring changes in the conjunctiva. Dendritic cells seem to be closely associated with the scarring process in trachoma and are likely to be an important target in antifibrotic therapies or the development of a chlamydial vaccine. The increased number of inflammatory cells seen in scarred subjects is consistent with the immunopathologic nature of the disease. The localization of cellular activity close to the conjunctival surface supports the view that the epithelium plays a central role in the pathogenesis of trachoma. Financial Disclosure(s) The author(s) have no proprietary or commercial interest in any materials discussed in this article. PMID:21920608

Hu, Victor H.; Weiss, Helen A.; Massae, Patrick; Courtright, Paul; Makupa, William; Mabey, David C.W.; Bailey, Robin L.; Burton, Matthew J.

2011-01-01

252

Worldwide distribution of Total Reflection X-ray Fluorescence instrumentation and its different fields of application: A survey  

NASA Astrophysics Data System (ADS)

A survey was carried out with users and manufacturers of Total Reflection X-ray Fluorescence instrumentation in order to demonstrate the worldwide distribution of TXRF equipment and the different fields of applications. In general, TXRF users come from universities and scientific institutes, from working places at synchrotron beam-lines, or laboratories in semiconductor fabs. TXRF instrumentation is distributed in more than 50 countries on six continents and is applied at about 200 institutes and laboratories. The number of running desktop instruments amounts to nearly 300 units. About 60 beamlines run working places dedicated to TXRF. About 300 floor-mounted instruments are estimated to be used in about 150 fabs of the semiconductor industry. In total, 13 different fields of applications could be registered statistically from three different aspects.

Klockenkämper, Reinhold; von Bohlen, Alex

2014-09-01

253

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

PubMed Central

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

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

2012-01-01

254

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

PubMed

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

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

2012-06-01

255

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

256

Temperature Variation Effects in a Reflective Electroabsorption Modulator-Based Network Architecture for Particle Physics Applications  

E-print Network

Architecture for Particle Physics Applications Spyridon Papadopoulos, Ioannis Papakonstantinou, Francois Vasey (EAMs) are seen to be of interest in the particle physics community due to their potential radiation technologies are prominent examples as they enable transfer of the large volumes of data generated by particle

Haddadi, Hamed

257

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

258

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

259

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

260

A new imaging method for confocal microscopy  

NASA Astrophysics Data System (ADS)

Confocal laser microscope (CLM) is indispensable today in the biology research field as the tool to clarify three dimensional structure and temporal transformations of living cells. The biggest advantage of CLM is to obtain "Optical slice images" in the direction of depth. The fluorescence from specimen is detected by a photo-detector in CLM through the small aperture called "Pinhole". The smaller the diameter of the pinhole is, the thinner the optical slice becomes. However, there is a problem that the contrast degrades because the images darken as the pinhole gets smaller, while the out-of-focus light increases as the pinhole is enlarged. To solve the problem, we developed a new detection method. In this method named "VAAS", it provides with the detector that captures light that doesn't pass through the pinhole in addition to the detector that captures light passes through the pinhole. Both detectors convert the light into electric signals at the same time. This method enables to eliminate out-of-focus light from the bright images acquired with large pinhole. In addition, quantitative experiments and analysis has proved that the contrast would be improved about 10dB compared with conventional CLM. VAAS is expected to be applied widely in the field of research to observe living cells where the reduction of optical toxicity is required in the future.

Okugawa, Hisashi

2008-02-01

261

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

262

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

NASA Technical Reports Server (NTRS)

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

Mcfadden, Lucy A.; Chamberlin, Alan B.

1992-01-01

263

Applicability of diffusion approximation in analysis of diffuse reflectance spectra from healthy human skin  

NASA Astrophysics Data System (ADS)

Measurement of diffuse reflectance spectra (DRS) is a common experimental approach for non-invasive determination of tissue optical properties, as well as objective monitoring of various tissue malformations. Propagation of light in scattering media is often treated in diffusion approximation (DA). The major advantage of this approach is that it leads to enclosed analytical solutions for tissues with layered structure, which includes human skin. Despite the fact that DA solutions were shown to be inaccurate near tissue boundaries, the practicality of this approach makes it quite popular, especially when attempting extraction of specific chromophore concentrations from measured DRS. In this study we analyze the discrepancies between DRS spectra as obtained by using the DA solutions for three-layer skin model and more accurate predictions from Monte Carlo (MC) modeling. Next, we analyze the artifacts which result from the above discrepancies when extracting the parameters of skin structure and composition by fitting the DA solutions to the MC spectra. The reliability and usefulness of such a fit is then tested also on measurements of seasonal changes in otherwise healthy human skin.

Nagli?, Peter; Vidovi?, Luka; Milani?, Matija; Randeberg, Lise L.; Majaron, Boris

2013-11-01

264

Application of total reflection X-ray fluorescence spectrometry to small glass fragments.  

PubMed

Total reflection X-ray fluorescence spectrometry (TXRF) has been applied for trace elemental analysis of small glass fragments. A small glass sample (a fragment with weight less than 0.5 mg) was decomposed by 100 microg of HF/HNO3 acid; the material was condensed to 10 microl and was dried on a Si wafer. Since the size of the dried residue on the Si wafer was less than 1 cm in diameter, an incident X-ray beam with about 1 cm in width could effectively excite elemental components in such a small glass fragment. The precision of the present technique was checked by analyzing the glass fragments (<0.5 mg) from NIST SRM612; the relative standard deviations (RSD) of less than 8.1% were achieved for elemental ratios that were normalized by Sr. Fragments (<0.5 mg) obtained from 23 figured sheet glasses were used as samples for estimating the utility of this technique to forensic discrimination. Comparison of five elemental ratios of Ti/Sr, Mn/Sr, Zn/Sr, Rb/Sr, and Pb/Sr calculated from X-ray fluorescence spectra was effective in distinguishing glass fragments that could not be differentiated by their refractive indexes (RI). PMID:17038765

Nishiwaki, Yoshinori; Shimoyama, Masahiko; Nakanishi, Toshio; Ninomiya, Toshio; Nakai, Izumi

2006-10-01

265

Solar Confocal Interferometers for Sub-Picometer-Resolution Spectral Filters  

NASA Technical Reports Server (NTRS)

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

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

2006-01-01

266

Multispectral confocal microendoscope for in vivo and in situ imaging  

E-print Network

instrument, and a laparoscopic version is currently being used to investigate ovarian cancer in an in vivo clinical trial. The details of the grayscale confocal microendoscope, and the general concept

Gmitro, Arthur F.

267

Efficient Confocal Microscopy with a Dual-Wedge Scanner  

E-print Network

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

Warger, William C., II

268

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...

269

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

270

Methods for Acquisition of Quantitative Data from Confocal Images of Gene Expression in situ  

PubMed Central

In this review, we summarize original methods for the extraction of quantitative information from confocal images of gene-expression patterns. These methods include image segmentation, the extraction of quantitative numerical data on gene expression, and the removal of background signal and spatial registration. Finally, it is possible to construct a spatiotemporal atlas of gene expression from individual images recorded at each developmental stage. Initially all methods were developed to extract quantitative numerical information from confocal images of segmentation gene expression in Drosophila melanogaster. The application of these methods to Drosophila images makes it possible to reveal new mechanisms in the formation of segmentation gene expression domains, as well as to construct a quantitative atlas of segmentation gene expression. Most image processing procedures can be easily adapted to process a wide range of biological images. PMID:19343098

Surkova, S. Yu.; Myasnikova, E. M.; Kozlov, K. N.; Samsonova, A. A.; Reinitz, J.; Samsonova, M. G.

2009-01-01

271

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

PubMed

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?; Câr?ân?, Tatiana; Ciurea, Tudorel; Popescu, Carmen; B?d?r?u, Anca; S?ftoiu, Adrian

2011-01-01

272

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

NASA Astrophysics Data System (ADS)

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 KNbO3 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.

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

2008-08-01

273

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

274

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

275

CCDiode: an optimal detector for laser confocal microscopes  

NASA Astrophysics Data System (ADS)

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

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

1996-04-01

276

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

277

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

PubMed

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. PMID:21806202

Song, Hoseok; Kim, Kiyoung; Lee, Jungju

2011-07-01

278

Confocal microscopy-based goniometry of barnacle cyprid permanent adhesive.  

PubMed

Biological adhesives are materials of particular interest in the fields of bio-inspired technology and antifouling research. The adhesive of adult barnacles has received much attention over the years; however, the permanent adhesive of the cyprid - the colonisation stage of barnacles - is a material about which very little is presently known. We applied confocal laser-scanning microscopy to the measurement of contact angles between the permanent adhesive of barnacle cyprid larvae and self-assembled monolayers of OH- and CH3-terminated thiols. Measurement of contact angles between actual bioadhesives and surfaces has never previously been achieved and the data may provide insight into the physicochemical properties and mechanism of action of these functional materials. The adhesive is a dual-phase system post-secretion, with the behaviour of the components governed separately by the surface chemistry. The findings imply that the cyprid permanent adhesion process is more complex than previously thought, necessitating broad re-evaluation of the system. Improved understanding will have significant implications for the production of barnacle-resistant coatings as well as development of bio-inspired glues for niche applications. PMID:23430996

Aldred, Nick; Gohad, Neeraj V; Petrone, Luigi; Orihuela, Beatriz; Liedberg, Bo; Ederth, Thomas; Mount, Andrew; Rittschof, Dan; Clare, Anthony S

2013-06-01

279

Phase relief imaging with confocal laser scanning system  

NASA Astrophysics Data System (ADS)

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

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

2013-02-01

280

Enhancement of fluorescence confocal scanning microscopy lateral resolution by use of structured illumination  

Microsoft Academic Search

Confocal microscopy is an optical imaging technique used to reconstruct three-dimensional images without physical sectioning. As with other optical microscopes, the lateral resolution of the confocal microscope cannot surpass the diffraction limit. This paper presents a novel imaging system, structured illumination confocal scanning microscopy (SICSM), that uses structured illumination to improve the lateral resolution of the confocal microscope. The SICSM

Taejoong Kim; Dae Gab Gweon; Jun-Hee Lee

2009-01-01

281

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

NASA Technical Reports Server (NTRS)

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

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

1991-01-01

282

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

283

Confocal fluorescence coincidence analysis: an approach to ultra high-throughput screening.  

PubMed

Fluorescence-based assay technologies play an increasing role in high-throughput screening. They can be classified into different categories: fluorescence polarization, time-resolved fluorescence, fluorescence resonance energy transfer, and fluorescence correlation spectroscopy. In this work we present an alternative analytical technique for high-throughput screening, which we call confocal fluorescence coincidence analysis. Confocal fluorescence coincidence analysis extracts fluorescence fluctuations that occur coincidently in two different spectral ranges from a tiny observation volume of below 1 fl. This procedure makes it possible to monitor whether an association between molecular fragments that are labeled with different fluorophores is established or broken. Therefore, it provides access to the characterization of a variety of cleavage and ligation reactions in biochemistry. Confocal fluorescence coincidence analysis is a very sensitive and ultrafast technique with readout times of 100 ms and below. This feature is demonstrated by means of a homogeneous assay for restriction endonuclease EcoRI. The presented achievements break ground for throughput rates as high as 10(6) samples per day with using only small amounts of sample substance and therefore constitute a solid base for screening applications in drug discovery and evolutionary biotechnology. PMID:9990031

Winkler, T; Kettling, U; Koltermann, A; Eigen, M

1999-02-16

284

Confocal fluorescence coincidence analysis: An approach to ultra high-throughput screening  

PubMed Central

Fluorescence-based assay technologies play an increasing role in high-throughput screening. They can be classified into different categories: fluorescence polarization, time-resolved fluorescence, fluorescence resonance energy transfer, and fluorescence correlation spectroscopy. In this work we present an alternative analytical technique for high-throughput screening, which we call confocal fluorescence coincidence analysis. Confocal fluorescence coincidence analysis extracts fluorescence fluctuations that occur coincidently in two different spectral ranges from a tiny observation volume of below 1 fl. This procedure makes it possible to monitor whether an association between molecular fragments that are labeled with different fluorophores is established or broken. Therefore, it provides access to the characterization of a variety of cleavage and ligation reactions in biochemistry. Confocal fluorescence coincidence analysis is a very sensitive and ultrafast technique with readout times of 100 ms and below. This feature is demonstrated by means of a homogeneous assay for restriction endonuclease EcoRI. The presented achievements break ground for throughput rates as high as 106 samples per day with using only small amounts of sample substance and therefore constitute a solid base for screening applications in drug discovery and evolutionary biotechnology. PMID:9990031

Winkler, Thorsten; Kettling, Ulrich; Koltermann, Andre; Eigen, Manfred

1999-01-01

285

Design and analysis of confocal-spectral microscopy using wavelength scanning scheme  

NASA Astrophysics Data System (ADS)

The multi-color, or spectral fluorescence microscopy has ability to detect fluorescence spectral signals which are useful in case of studying interactions and phenomena between biological samples. Recently, commercial devices are combining with confocal microscope so to enhance lateral resolution and to have axial direction discernment. Also Acousto-Optic Tunable Filter(AOTF) is used instead of dichroic mirror to divide excitation and emission signals with mininum light efficiency. In addition, AOTF is used in spectral fluorescence microscopy have many advantages, these are very fast switching speed and high resolution in wavelength selection. However it uses acousto-optic interactions in birefringence material, Tellurium Dioxide(TeO2), the excitation light interacts with appropriate acoustic signal so that it is diffracted to 1 or -1 order path. But the fluorescence signals from a sample propagate in 0 order path with small different angle according to the polarization state. In this paper, a confocal-spectral microscopy is proposed with the new kind of spectral detector design having wavelength scanning galvano mirror. It makes possible to detect broad wavelength fluorescence signal by single PMT with simply rotating the galvano mirror. Also a new birefringent material, calcite(CaCO3) is used to compensate polarization effect. The proposed spectral confocal microscopy with unique spectrometer body has many advantages in comparison with commercial devices. In terms of detection method, it can be easily applied to other imaging modalities. Hence this system will be adapted in many applications.

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

2011-03-01

286

In vivo Confocal Microscopy Report after Lasik with Sequential Accelerated Corneal Collagen Cross-Linking Treatment  

PubMed Central

We report the first pilot qualitative confocal microscopic analysis of a laser in situ keratomileusis (Lasik) treatment combined with sequential high-fluence accelerated corneal collagen cross-linking, denominated Lasik XTra, by means of HRT II laser scanning in vivo confocal microscopy after a 6-month follow-up. After obtaining approval from the Siena University Hospital Institutional Review Board, a 33-year-old female patient underwent a Lasik XTra procedure in her left eye. Confocal analysis demonstrated induced slight corneal microstructural changes by the interaction between UV-A, riboflavin and corneal stromal collagen, beyond the interface to a depth of 160 µm, without adverse events at the interface and endothelial levels. This application may be considered a prophylactic biomechanical treatment, stiffening the intermediate corneal stroma to prevent corneal ectasia and stabilizing the clinical results of refractive surgery. According to our preliminary experiences, this combined approach may be useful in higher-risk Lasik patients for hyperopic treatments, high myopia and lower corneal thicknesses. PMID:24847258

Mazzotta, Cosimo; Balestrazzi, Angelo; Traversi, Claudio; Caragiuli, Stefano; Caporossi, Aldo

2014-01-01

287

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

PubMed

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

Shaver, Mark D; Sun, Xiao-Ming

2013-07-01

288

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

289

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

290

Confocal volume in laser Raman microscopy depth profiling  

SciTech Connect

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

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

2011-11-15

291

Spinning Disk Confocal Imaging of Neutrophil Migration in Zebrafish  

PubMed Central

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

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

2014-01-01

292

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

293

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

294

Optimization of confocal laser induced fluorescence in a plasmaa)  

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

295

A Pico Projector Source for Confocal Fluorescence and Ophthalmic Imaging  

PubMed Central

A Pico digital light projector has been implemented as an integrated illumination source and spatial light modulator for confocal imaging. The target is illuminated with a series of rapidly projected lines or points to simulate scanning. Light returning from the target is imaged onto a 2D rolling shutter CMOS sensor. By controlling the spatio-temporal relationship between the rolling shutter and illumination pattern, light returning from the target is spatially filtered. Confocal retinal, fluorescence, and Fourier-domain optical coherence tomography implementations of this novel imaging technique are presented. PMID:24236223

Muller, Matthew S.

2013-01-01

296

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 µs. 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

297

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

298

A novel approach to detect and characterize the scattering patterns of single Au nanoparticles using confocal microscopy.  

PubMed

We demonstrate a novel optical method for characterizing single Au nanoparticles by acquiring their scattering patterns. This technique combines confocal microscopy and higher-order laser modes for detecting the light scattered by sub-wavelength-sized nanoobjects. The optical patterns are generated by the coherent superposition of the field scattered by individual metallic particles and the excitation field reflected at the cover slide-air interface and provide information about the particles' position, orientation, size and shape. Detectable changes in the full width at half maximum (FWHM) of the signal intensity permit to distinguish between 20- and 60-nm diameter Au spheres. The confocal images are also very sensitive to the particle's geometry and polarizability, that is, Au nanospheres, Au nanorods and triangular Au nanoplates give different characteristic patterns if the excitation wavelength is varied. PMID:18304095

Züchner, T; Failla, A V; Hartschuh, A; Meixner, A J

2008-02-01

299

Confocal absorption microscopy of biomolecules and single cells from the visible to the ultraviolet spectral range  

NASA Astrophysics Data System (ADS)

We present a versatile approach for absorption spectroscopy on the micron scale that combines a broadband white light source with a confocal microscope and a multichannel detector. The attenuation of the propagating light provides a mechanism for contrast that allows spectrally resolved measurements of biomolecules in minuscule quantities and of single live cells. UV absorption spectra of aromatic amino acids, proteins, and single stranded DNA oligomers (100 bases) in solution are measured with less than 10^7 molecules in the probe volume. We discuss applications to spectroscopically identify heterogeneities at the single cell level and to the label-free detection of nucleic acids.

Salehi, Fatholah; Park, Sanghoon; Sigman, Michael E.; Schulte, Alfons

2013-03-01

300

Insights into esophagus tissue architecture using two-photon confocal microscopy  

NASA Astrophysics Data System (ADS)

In this paper, microstructures of human esophageal mucosa were evaluated using the two-photon laser scanning confocal microscopy (TPLSCM), based on two-photon excited fluorescence (TPEF) and second harmonic generation (SHG). The distribution of epithelial cells, muscle fibers of muscularis mucosae has been distinctly obtained. Furthermore, esophageal submucosa characteristics with cancer cells invading into were detected. The variation of collagen, elastin and cancer cells is very relevant to the pathology in esophagus, especially early esophageal cancer. Our experimental results indicate that the MPM technique has the much more advantages for label-free imaging, and has the potential application in vivo in the clinical diagnosis and monitoring of early esophageal cancer.

Liu, Nenrong; Wang, Yue; Feng, Shangyuan; Chen, Rong

2013-08-01

301

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

PubMed Central

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

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

2007-01-01

302

APPLICATION FOR DEPARTMENTAL "HONORS IN PSYCHOLOGY" This form reflects requirements for students who declared the major in Fall 2007 or later.  

E-print Network

PSYC 102 102 3 Abnormal Psychology PSYC 110 110 3 Research Methods: Honors requires both Methods (120APPLICATION FOR DEPARTMENTAL "HONORS IN PSYCHOLOGY" This form reflects requirements for students: _______ Intended Graduation Date: ___________ Whether or not to award Departmental Honors in Psychology

Su, Xiao

303

Confocal mosaicing microscopy in skin excisions: a demonstration of rapid surgical pathology  

PubMed Central

Summary Precise micro-surgical removal of tumour with minimal damage to the surrounding normal tissue requires a series of excisions, each guided by an examination of frozen histology of the previous. An example is Mohs surgery for the removal of basal cell carcinomas (BCCs) in skin. The preparation of frozen histology is labour-intensive and slow. Confocal microscopy may enable rapid detection of tumours directly in surgical excisions with minimal need for frozen histology. Mosaicing of images enables observation of nuclear and cellular morphology in large areas of surgically excised tissue. In skin, the use of 10–1% acetic acid as a reflectance contrast agent brightens nuclei in 0.5–5 min and enhances nuclear-to-dermis contrast and detectability of BCCs. A tissue fixture was engineered for precisely mounting surgical excisions to enable mosaicing of 36 × 36 images to create a field of view of 12 × 12 mm. This large field of view displays the excision at 2× magnification, similar to that routinely used by Mohs surgeons when examining frozen histology. Comparison of mosaics to histology demonstrates detectability of BCCs. Confocal mosaicing presently requires 9 min, instead of 20–45 min per excision for preparing frozen histology, and thus may provide a means for rapid pathology-at-the-bedside to expedite and guide surgery. PMID:19196421

Gareau, D.S.; Patel, Y.G.; Li, Y.; Aranda, I.; Halpern, A.C.; Nehal, K.S.; Rajadhyaksha, M.

2009-01-01

304

Chromatic confocal microscopy for multi-depth imaging of epithelial tissue.  

PubMed

We present a novel chromatic confocal microscope capable of volumetric reflectance imaging of microstructure in non-transparent tissue. Our design takes advantage of the chromatic aberration of aspheric lenses that are otherwise well corrected. Strong chromatic aberration, generated by multiple aspheres, longitudinally disperses supercontinuum light onto the sample. The backscattered light detected with a spectrometer is therefore wavelength encoded and each spectrum corresponds to a line image. This approach obviates the need for traditional axial mechanical scanning techniques that are difficult to implement for endoscopy and susceptible to motion artifact. A wavelength range of 590-775 nm yielded a >150 µm imaging depth with ~3 µm axial resolution. The system was further demonstrated by capturing volumetric images of buccal mucosa. We believe these represent the first microstructural images in non-transparent biological tissue using chromatic confocal microscopy that exhibit long imaging depth while maintaining acceptable resolution for resolving cell morphology. Miniaturization of this optical system could bring enhanced speed and accuracy to endomicroscopic in vivo volumetric imaging of epithelial tissue. PMID:23667789

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

2013-05-01

305

Chromatic confocal microscopy for multi-depth imaging of epithelial tissue  

PubMed Central

We present a novel chromatic confocal microscope capable of volumetric reflectance imaging of microstructure in non-transparent tissue. Our design takes advantage of the chromatic aberration of aspheric lenses that are otherwise well corrected. Strong chromatic aberration, generated by multiple aspheres, longitudinally disperses supercontinuum light onto the sample. The backscattered light detected with a spectrometer is therefore wavelength encoded and each spectrum corresponds to a line image. This approach obviates the need for traditional axial mechanical scanning techniques that are difficult to implement for endoscopy and susceptible to motion artifact. A wavelength range of 590-775 nm yielded a >150 µm imaging depth with ~3 µm axial resolution. The system was further demonstrated by capturing volumetric images of buccal mucosa. We believe these represent the first microstructural images in non-transparent biological tissue using chromatic confocal microscopy that exhibit long imaging depth while maintaining acceptable resolution for resolving cell morphology. Miniaturization of this optical system could bring enhanced speed and accuracy to endomicroscopic in vivo volumetric imaging of epithelial tissue. PMID:23667789

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

2013-01-01

306

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

307

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

308

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

309

Confocal mosaicing microscopy in skin excisions: a demonstration of rapid surgical pathology.  

PubMed

Precise micro-surgical removal of tumour with minimal damage to the surrounding normal tissue requires a series of excisions, each guided by an examination of frozen histology of the previous. An example is Mohs surgery for the removal of basal cell carcinomas (BCCs) in skin. The preparation of frozen histology is labour-intensive and slow. Confocal microscopy may enable rapid detection of tumours directly in surgical excisions with minimal need for frozen histology. Mosaicing of images enables observation of nuclear and cellular morphology in large areas of surgically excised tissue. In skin, the use of 10-1% acetic acid as a reflectance contrast agent brightens nuclei in 0.5-5 min and enhances nuclear-to-dermis contrast and detectability of BCCs. A tissue fixture was engineered for precisely mounting surgical excisions to enable mosaicing of 36 x 36 images to create a field of view of 12 x 12 mm. This large field of view displays the excision at 2x magnification, similar to that routinely used by Mohs surgeons when examining frozen histology. Comparison of mosaics to histology demonstrates detectability of BCCs. Confocal mosaicing presently requires 9 min, instead of 20-45 min per excision for preparing frozen histology, and thus may provide a means for rapid pathology-at-the-bedside to expedite and guide surgery. PMID:19196421

Gareau, D S; Patel, Y G; Li, Y; Aranda, I; Halpern, A C; Nehal, K S; Rajadhyaksha, M

2009-01-01

310

Automated detection of malignant features in confocal microscopy on superficial spreading melanoma versus nevi  

PubMed Central

In-vivo reflectance confocal microscopy (RCM) shows promise for the early detection of superficial spreading melanoma (SSM). RCM of SSM shows pagetoid melanocytes (PMs) in the epidermis and disarray at the dermal-epidermal junction (DEJ), which are automatically quantified with a computer algorithm that locates depth of the most superficial pigmented surface [DSPS(x,y)] containing PMs in the epidermis and pigmented basal cells near the DEJ. The algorithm uses 200 noninvasive confocal optical sections that image the superficial 200 ?m of ten skin sites: five unequivocal SSMs and five nevi. The pattern recognition algorithm automatically identifies PMs in all five SSMs and finds none in the nevi. A large mean gradient ? (roughness) between laterally adjacent points on DSPS(x,y) identifies DEJ disruption in SSM ? = 11.7 ± 3.7 [?] for n = 5 SSMs versus a small ? = 5.5 ± 1.0 [?] for n = 5 nevi (significance, p = 0.0035). Quantitative endpoint metrics for malignant characteristics make digital RCM data an attractive diagnostic asset for pathologists, augmenting studies thus far, which have relied largely on visual assessment. PMID:21198161

Gareau, Dan; Hennessy, Ricky; Wan, Eric; Pellacani, Giovanni; Jacques, Steven L.

2010-01-01

311

Automated detection of malignant features in confocal microscopy on superficial spreading melanoma versus nevi  

NASA Astrophysics Data System (ADS)

In-vivo reflectance confocal microscopy (RCM) shows promise for the early detection of superficial spreading melanoma (SSM). RCM of SSM shows pagetoid melanocytes (PMs) in the epidermis and disarray at the dermal-epidermal junction (DEJ), which are automatically quantified with a computer algorithm that locates depth of the most superficial pigmented surface [DSPS(x,y)] containing PMs in the epidermis and pigmented basal cells near the DEJ. The algorithm uses 200 noninvasive confocal optical sections that image the superficial 200 ?m of ten skin sites: five unequivocal SSMs and five nevi. The pattern recognition algorithm automatically identifies PMs in all five SSMs and finds none in the nevi. A large mean gradient ? (roughness) between laterally adjacent points on DSPS(x,y) identifies DEJ disruption in SSM ? = 11.7 +/- 3.7 [-] for n = 5 SSMs versus a small ? = 5.5 +/- 1.0 [-] for n = 5 nevi (significance, p = 0.0035). Quantitative endpoint metrics for malignant characteristics make digital RCM data an attractive diagnostic asset for pathologists, augmenting studies thus far, which have relied largely on visual assessment.

Gareau, Dan; Hennessy, Ricky; Wan, Eric; Pellacani, Giovanni; Jacques, Steven L.

2010-11-01

312

Automated detection of malignant features in confocal microscopy on superficial spreading melanoma versus nevi.  

PubMed

In-vivo reflectance confocal microscopy (RCM) shows promise for the early detection of superficial spreading melanoma (SSM). RCM of SSM shows pagetoid melanocytes (PMs) in the epidermis and disarray at the dermal-epidermal junction (DEJ), which are automatically quantified with a computer algorithm that locates depth of the most superficial pigmented surface [D(SPS)(x,y)] containing PMs in the epidermis and pigmented basal cells near the DEJ. The algorithm uses 200 noninvasive confocal optical sections that image the superficial 200 ?m of ten skin sites: five unequivocal SSMs and five nevi. The pattern recognition algorithm automatically identifies PMs in all five SSMs and finds none in the nevi. A large mean gradient ? (roughness) between laterally adjacent points on D(SPS)(x,y) identifies DEJ disruption in SSM ? = 11.7 ± 3.7 [-] for n = 5 SSMs versus a small ? = 5.5 ± 1.0 [-] for n = 5 nevi (significance, p = 0.0035). Quantitative endpoint metrics for malignant characteristics make digital RCM data an attractive diagnostic asset for pathologists, augmenting studies thus far, which have relied largely on visual assessment. PMID:21198161

Gareau, Dan; Hennessy, Ricky; Wan, Eric; Pellacani, Giovanni; Jacques, Steven L

2010-01-01

313

Saturated structured confocal microscopy with theoretically unlimited resolution  

E-print Network

1 Saturated structured confocal microscopy with theoretically unlimited resolution Olivier Haeberlé structured illumination, saturation may however be used to improve the resolution [7-8]. With this method propose and study numerically a simple method, based on a combination of subtraction microscopy

Paris-Sud XI, Université de

314

Confocal microscopy study of colloidal sedimentation and crystallization  

E-print Network

of the fluid/solid transition. Also, it was demonstrated that the grain size in depletion crystals formed from quantum dot-coated silica particles can be increased by localized annealing with the confocal microscope’s laser. Additional findings include...

Beckham, Richard Edward

2009-05-15

315

Mosaicing of Confocal Microscopic In Vivo Soft Tissue Video Sequences  

E-print Network

is the ability to reject light from out-of-focus planes and provide a clear in-focus image of a thin section within the sample. This optical sectioning property is what makes the confocal microscope ideal the scanning device and the microscope objective. After image processing of the FCM raw output, the available

Boyer, Edmond

316

Whole-Mount Confocal Microscopy for Vascular Branching Morphogenesis  

PubMed Central

We introduce a whole-mount immunohistochemistry method for analyzing intricate vascular network formation in mouse embryonic tissues. Laser scanning confocal microscopy with multiple labeling allows for robust imaging of blood and lymphatic vessel branching morphogenesis with excellent resolution. PMID:22222522

Mukouyama, Yoh-suke; James, Jennifer; Nam, Joseph; Uchida, Yutaka

2014-01-01

317

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

318

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

319

How the Confocal Laser Scanning Microscope entered Biological Research  

Microsoft Academic Search

A history of the early development of the confocal laser scanning microscope in the MRC Laboratory of Molecular Biology in Cambridge is presented. The rapid uptake of this technology is explained by the wide use of fluorescence in the 80s. The key innovations were the scanning of the light beam over the specimen rather than vice-versa and a high magnification

W. B. Amos; J. G. White

2003-01-01

320

Observing the Coral Symbiome Using Laser Scanning Confocal Microscopy  

NSDL National Science Digital Library

Christine E. Farrar and colleaguesâ 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 ;); Zac H. Forsman (Hawai'i Institute of Marine Biology at the University of Hawai'i, Manoa ;); Ruth D. Gates (Hawai'i Institute of Marine Biology at the University of Hawai'i, Manoa ;); Jo-Ann C. Leong (Hawai'i Institute of Marine Biology at the University of Hawai'i, Manoa ;); Robert J. Toonen (Hawai'i Institute of Marine Biology at the University of Hawai'i, Manoa ;)

2013-02-01

321

Semiquantitative Confocal Laser Scanning Microscopy Applied to Marine Invertebrate Ecotoxicology  

Microsoft Academic Search

Confocal laser scanning microscopy (CLSM) represents a powerful, but largely unexplored ecotoxicologic tool for rapidly assessing in vivo effects of toxicants on marine invertebrate embryo quality and development. We describe here a new semiquantitative CLSM approach for assessing relative yolk quantity in marine invertebrate embryos (harpacticoid copepods) produced by parents reared from hatching to adult in the polycylic aromatic hydrocarbon

G. Thomas Chandler; David C. Volz

2004-01-01

322

Feulgen staining of intact plant tissues for confocal microscopy.  

PubMed

A method was developed to prepare plant structures for confocal laser scanning microscopy by combining Feulgen staining with pararosaniline and embedding in LR White(TM). This procedure preserves intact, delicate structures for three-dimensional imaging without loss from sectioning or squashing, and the slides can be viewed several times without serious photo-bleaching. PMID:9138536

Braselton, J P; Wilkinson, M J; Clulow, S A

1996-03-01

323

Double refraction and reflection of sequential crystal interfaces with arbitrary orientation of the optic axis and application to optimum design  

Microsoft Academic Search

The general formulation of double refraction or internal double reflection for any directions of incidence and arbitrary orientation of the optic axis in a uniaxial crystal is analysed in terms of Huygens' principle. Then double refraction and double reflection along the sequential interfaces in a crystal are discussed. On this basis, if the parameters of the interface are chosen appropriately,

Haixia Ren; Liren Liu; De’an Liu; Zhe Song

2005-01-01

324

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; Góral, Tomasz; Szpila, Krzysztof; Hall, Martin J R

2014-11-01

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

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

327

Descemetic and Predescemetic DALK in Keratoconus Patients: A Clinical and Confocal Perspective Study  

PubMed Central

Purpose. To evaluate the clinical outcomes and in vivo confocal microscopy (IVCM) features of keratoconus patients who underwent deep anterior lamellar keratoplasty (DALK). Methods. DALK was performed using the big bubble technique in all the patients. If the bubble was not successful to bare the descemet membrane, a manual dissection layer-by layer was performed to expose a deep stromal plane close to the DM. The patients were divided in two groups depending on the intraoperative baring of the descemet membrane: predescemetic DALK (PD-DALK) and descemetic DALK (D-DALK) group. Results. One month after surgery the D-DALK patients show an increase of mean BCVA. In the PD-DALK group mean BCVA did not show significant improvement as compared to preoperative values. At 6 months after surgery mean BCVA was found to be similar in both groups. At 1 month IVCM the peak of reflectivity of the interface was lower in D-DALK group compared to PD-DALK. At 6 months the values of reflectivity were comparable. Conclusions. At 1 month D-DALK seems to lead to a minor interface reflectivity and to a better BCVA; these differences disappear after 6 months and the values of interface reflectivity and BCVA are comparable between D-DALK and PD-DALK.

Schiano-Lomoriello, Domenico; Colabelli-Gisoldi, Rossella Annamaria; Nubile, Mario; Oddone, Francesco; Villani, Carlo Maria; Pocobelli, Augusto

2014-01-01

328

A new method for imaging and 3D reconstruction of mammalian cochlea by fluorescent confocal microscopy  

E-print Network

be viewed by most fluorescent microscopy methods including laser scanning confocal microscopy, multi from acellular gelatinous material (the tectorial membrane) and dense bone (the otic capsule partly overcome by imaging the cochlea in vitro with laser scanning confocal microscopy, after

Rubel, Edwin

329

Reflectance Spectra  

NSDL National Science Digital Library

Katherine McCarville, Upper Iowa University Summary Students use the ALTA reflectance spectrometer to understand concepts in active vs. passive remote sensing, reflectance, and the creation and relevance of ...

Mccarville, Katherine

330

Chapter: Reflection groups  

Microsoft Academic Search

This chapter is concerned with the theory of finite reflection groups, that is, finite groups generated by reflections in a real or complex vector space. This is a rich theory, both for intrinsic reasons and as far as applications in other mathematical areas or mathematical physics are concerned. The origin of the theory can be traced back to the ancient

MEINOLF GECK; GUNTER MALLE

331

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

E-print Network

, the technique of structured illumination permits to improve the lateral resolution by a factor of two, even even beating confocal microscopy. Confocal microscopy may in fact also be considered as a structured3 Multi-kernel deconvolution applied to confocal fluorescence microscopy with engineered point

Paris-Sud XI, Université de

332

The CCDiode: An optimal detector for laser confocal microscopes J. Pawley, M. Blouke* and J. Janesick*  

E-print Network

" the confocal spot as it is deflected by inhomogeneities of the specimen, change its effective size or shape rate of 1 MHz, our new device utilizes 64 separate readout amplifier/digitizer systems, operating-noise CCD. 1. INTRODUCTION 1.1 Confocal laser-scanning microscope operation The laser confocal microscope

Pawley, James

333

The effects of a double layer anti-reflection coating for a buried contact solar cell application  

Microsoft Academic Search

Theoretical and experimental investigations were performed on a double layer anti-reflection (DLAR) coating of MgF2\\/CeO2. We investigated CeO2 films as an AR layer because they have a proper refractive index of 2.46 and demonstrate the same lattice constant as the Si substrate. An optimized DLAR coating showed a reflectance value as low as 1.87% over wavelengths ranging from 0.4 to

I. Lee; D. G. Lim; S. H. Lee; J. Yi

2001-01-01

334

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

335

Mathematical models for the reflection coefficients of lossy dielectric half-spaces with application to transient responses of chirped pulses  

NASA Technical Reports Server (NTRS)

Reflection coefficients are found at normal incidence for a large class of homogeneous lossy half-spaces with a one-dimensionally inhomogeneous or stratified lossy layer on top. Solutions are in terms of Hankel functions of complex argument to decrease cancellation error at high frequencies. One special case is that of layers on a homogeneous half-space where the dielectric constant in each layer may vary in a quite general manner. A Wronskian is used to insure the critical computations are correct. The reflection of chirped pulses is considered. Solutions are obtained by applying the fast Fourier transform. It is found that for a typical relatively long normalized 'long' pulse the power reflected as a function of time is essentially the power reflection coefficient for the frequencies swept out, whereas for a relatively short 'long' pulse, with the same relative change in frequency and the same number of oscillations there is only the uniform attenuation by the power reflection coefficient of the center frequency. By a 'long' pulse we mean a pulse whose spatial length is long compared to the thickness of the reflecting layer.

Evans, D. D.

1977-01-01

336

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.

337

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

338

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

E-print Network

s to 5 min, respectively. A tissue fixture precisely controls the stability, flatness, tilt, and sag of the excisions, which enables mosaicing of 36 36 images to create a field of view of 12 12 mm. This simulates a 2 expedite Mohs surgery. � 2007 Society of Photo-Optical Instrumentation Engineers. DOI: 10

Sridhar, Srinivas

339

Enhanced resolution of specific chromosome and nuclear regions by reflectance laser scanning confocal microscopy  

Microsoft Academic Search

DNA sequences digested by HaeIII and reconstructed by in situ nick translation employing digoxigenin-labelled nucleotides are usually revealed either by\\u000a horseradish peroxidase or FITC fluorescence. To obtain a significant improvement in terms of resolution, sensitivity and specificity,\\u000a colloidal gold has been used instead of FITC (as the reporter molecule) to reveal the labelled DNA. Colloidal gold and propidium\\u000a iodide were

Luca M. Neri; Caterina Cinti; Spartaco Santi; Marco Marchisio; Silvano Capitani; Nadir M. Maraldi

1997-01-01

340

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

PubMed

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

2012-08-01

341

Reflectance and Fluorescence Confocal Microscope for Imaging of the Mouse Colon  

E-print Network

of Biomedical Optics Express. 1. INTRODUCTION 1.1 Motivation Those experiencing ulcerative colitis or Crohn?s disease have an increased risk for developing colorectal cancer; therefore, there is an assumption that chronic inflammation causes cancer [1...]. Ulcerative colitis is reported as inflammation in the colon that is restricted to the mucosa or innermost layer [2]. Crohn?s disease includes the small intestine, colon, and other surrounding organs [3]. Currently, it is recommended that patients...

Saldua, Meagan Alyssa

2012-02-14

342

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

343

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; Höschele, Christoph; Wang, Xiaojie; Beyeler, Barbara; Meier, Christoph; Lussi, Adrian

2011-10-01

344

High-efficiency reflective diffraction gratings in fused silica as (de)multiplexers at 1.55microm for dense wavelength division multiplexing application.  

PubMed

We describe high-efficiency, high-dispersion reflection gratings fabricated in bulk fused silica illuminated by incident lights in the C + L bands as (de)multiplexers for dense wavelength division multiplexing (DWDM) application. Based on the phenomenon of total internal reflection, gratings with optimized profile parameters exhibit diffraction efficiencies of more than 90% under TM- and TE-polarized incident lights for 101-nm spectral bandwidths (1520-1620 nm) and can reach an efficiency of greater than 97% for both polarizations at a wavelength of 1550 nm. Without loss of metal absorption, without coating of dielectric film layers, and independent of tooth shape, this new kind of grating should be of great interest for DWDM application. PMID:15717563

Zhang, Yanyan; Zhou, Changhe

2005-02-01

345

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 Cavé; Bertrand Viellerobe; Frederic Berier; Benjamin Abrat; Nicholas Ayache

2004-01-01

346

Photothermal confocal spectromicroscopy of multiple cellular chromophores and fluorophores.  

PubMed

Confocal fluorescence microscopy is a powerful biological tool providing high-resolution, three-dimensional (3D) imaging of fluorescent molecules. Many cellular components are weakly fluorescent, however, and thus their imaging requires additional labeling. As an alternative, label-free imaging can be performed by photothermal (PT) microscopy (PTM), based on nonradiative relaxation of absorbed energy into heat. Previously, little progress has been made in PT spectral identification of cellular chromophores at the 3D microscopic scale. Here, we introduce PTM integrating confocal thermal-lens scanning schematic, time-resolved detection, PT spectral identification, and nonlinear nanobubble-induced signal amplification with a tunable pulsed nanosecond laser. The capabilities of this confocal PTM were demonstrated for high-resolution 3D imaging and spectral identification of up to four chromophores and fluorophores in live cells and Caenorhabditis elegans. Examples include cytochrome c, green fluorescent protein, Mito-Tracker Red, Alexa-488, and natural drug-enhanced or genetically engineered melanin as a PT contrast agent. PTM was able to guide spectral burning of strong absorption background, which masked weakly absorbing chromophores (e.g., cytochromes in the melanin background). PTM provided label-free monitoring of stress-related changes to cytochrome c distribution, in C. elegans at the single-cell level. In nonlinear mode ultrasharp PT spectra from cyt c and the lateral resolution of 120 nm during calibration with 10-nm gold film were observed, suggesting a potential of PTM to break through the spectral and diffraction limits, respectively. Confocal PT spectromicroscopy could provide a valuable alternative or supplement to fluorescence microscopy for imaging of nonfluorescent chromophores and certain fluorophores. PMID:22325291

Nedosekin, Dmitry A; Galanzha, Ekaterina I; Ayyadevara, Srinivas; Shmookler Reis, Robert J; Zharov, Vladimir P

2012-02-01

347

Confocal Imaging of the Embryonic Heart: How Deep?  

NASA Astrophysics Data System (ADS)

Confocal microscopy allows for optical sectioning of tissues, thus obviating the need for physical sectioning and subsequent registration to obtain a three-dimensional representation of tissue architecture. However, practicalities such as tissue opacity, light penetration, and detector sensitivity have usually limited the available depth of imaging to 200 [mu]m. With the emergence of newer, more powerful systems, we attempted to push these limits to those dictated by the working distance of the objective. We used whole-mount immunohistochemical staining followed by clearing with benzyl alcohol-benzyl benzoate (BABB) to visualize three-dimensional myocardial architecture. Confocal imaging of entire chick embryonic hearts up to a depth of 1.5 mm with voxel dimensions of 3 [mu]m was achieved with a 10× dry objective. For the purpose of screening for congenital heart defects, we used endocardial painting with fluorescently labeled poly-L-lysine and imaged BABB-cleared hearts with a 5× objective up to a depth of 2 mm. Two-photon imaging of whole-mount specimens stained with Hoechst nuclear dye produced clear images all the way through stage 29 hearts without significant signal attenuation. Thus, currently available systems allow confocal imaging of fixed samples to previously unattainable depths, the current limiting factors being objective working distance, antibody penetration, specimen autofluorescence, and incomplete clearing.

Miller, Christine E.; Thompson, Robert P.; Bigelow, Michael R.; Gittinger, George; Trusk, Thomas C.; Sedmera, David

2005-06-01

348

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

349

A deep view in cultural heritage—confocal micro X-ray spectroscopy for depth resolved elemental analysis  

NASA Astrophysics Data System (ADS)

Quantitative X-ray fluorescence (XRF) and particle induced X-ray emission (PIXE) techniques have been developed mostly for the elemental analysis of homogeneous bulk or very simple layered materials. Further on, the microprobe version of both techniques is applied for 2D elemental mapping of surface heterogeneities. At typical XRF/PIXE fixed geometries and exciting energies (15-25 keV and 2-3 MeV, respectively), the analytical signal (characteristic X-ray radiation) emanates from a variable but rather extended depth within the analyzed material, according to the exciting probe energy, set-up geometry, specimen matrix composition and analyte. Consequently, the in-depth resolution offered by XRF and PIXE techniques is rather limited for the characterization of materials with micrometer-scale stratigraphy or 3D heterogeneous structures. This difficulty has been over-passed to some extent in the case of an X-ray or charged particle microprobe by creating the so-called confocal geometry. The field of view of the X-ray spectrometer is spatially restricted by a polycapillary X-ray lens within a sensitive microvolume formed by the two inter-sectioned focal regions. The precise scanning of the analyzed specimen through the confocal microvolume results in depth-sensitive measurements, whereas the additional 2D scanning microprobe possibilities render to element-specific 3D spatial resolution (3D micro-XRF and 3D micro-PIXE). These developments have contributed since 2003 to a variety of fields of applications in environmental, material and life sciences. In contrast to other elemental imaging methods, no size restriction of the objects investigated and the non-destructive character of analysis have been found indispensable for cultural heritage (CH) related applications. The review presents a summary of the experimental set-up developments at synchrotron radiation beamlines, particle accelerators and desktop spectrometers that have driven methodological developments and applications of confocal X-ray microscopy including depth profiling speciation studies by means of confocal X-ray absorption near edge structure (XANES) spectroscopy. The solid mathematical formulation developed for the quantitative in-depth elemental analysis of stratified materials is exemplified and depth profile reconstruction techniques are discussed. Selected CH applications related to the characterization of painted layers from paintings and decorated artifacts (enamels, glasses and ceramics), but also from the study of corrosion and patina layers in glass and metals, respectively, are presented. The analytical capabilities, limitations and future perspectives of the two variants of the confocal micro X-ray spectroscopy, 3D micro-XRF and 3D micro-PIXE, with respect to CH applications are critically assessed and discussed.

Kanngießer, B.; Malzer, W.; Mantouvalou, I.; Sokaras, D.; Karydas, A. G.

2012-02-01

350

Extraction of three-dimensional information of biological membranous tissue with scanning confocal infrared laser microscope tomography.  

PubMed

The "LEXT" confocal laser scanning microscope has been used for the three-dimensional (3D) imaging of the surface of specimens, especially in materials science fields, by the penetration of near-infrared (NIR) light without mechanical cutting, deposition, or other specimen pretreatment. Noninvasive investigation of various biological tissues such as human spinal dura mater, rat aorta, and cornea without the dehydration process was successfully carried out with the "LEXT," in order to access both surface and internal topographic images of the biological structures at a good status of the wet tissue such as in vivo, especially in measuring tissue thickness. The confocal NIR laser microscopy offers the viable means to visualize tissue architecture and its thickness in microdomain to integrate 3D images efficiently. We believe that the "LEXT" has a good application for biological researchers to study biomaterials, and it would be useful as a diagnostic tool in the near future. PMID:23920204

Kwon, Soonwook; Choi, Se-Bum; Park, Min Gyu; Yu, Hyunung; Suh, Seung-Woo; Rhyu, Im Joo

2013-08-01

351

Investigation of low-reflective ZrCN–PVD-arc coatings for application on medical tools for minimally invasive surgery  

Microsoft Academic Search

Medical tools for minimally invasive surgery are often used under difficult environmental conditions. If the surgeons have to work with a microscope, the operating area must be brightly lit. Reflection and scattering of light from tool-surfaces disturb the visual field. To decrease this kind of disturbance, the tools can be covered by a dark PVD thin film. In the present

F Hollstein; D Kitta; P Louda; F Pacal; J Meinhardt

2001-01-01

352

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

353

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

354

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

355

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

356

Novel approach to real-time flash photolysis and confocal [Ca2+] imaging  

PubMed Central

Flash photolysis of “caged” compounds using ultraviolet light is a powerful experimental technique for producing rapid changes in concentrations of bioactive signaling molecules. Studies that employ this technique have used diverse strategies for controlling the spatial and temporal application of light to the specimen. Here we describe a new system for flash photolysis that delivers light from a pulsed, adjustable intensity laser through an optical fiber coupled into the epifluorescence port of a commercial confocal microscope. Photolysis is achieved with extremely brief (5 ns) pulses of ultraviolet light (355 nm) that can be synchronized with respect to confocal laser scanning. The system described also localizes the UV intensity spatially so that uncaging only occurs in defined sub-cellular regions; moreover, since the microscope optics are used in localization, the photolysis volume can be easily adjusted. Experiments performed on rat ventricular myocytes loaded with the Ca2+ indicator fluo-3 and the Ca2+ cage NP-EGTA demonstrate the system's capabilities. Localized intracellular increases in [Ca2+] can trigger sarcoplasmic reticular Ca2+ release events such as Ca2+ sparks and, under certain conditions, regenerative Ca2+ waves. This relatively simple and inexpensive system is therefore a useful tool for examining local signaling in heart and other tissues. PMID:17323075

Sobie, Eric A.; Kao, Joseph P.Y.; Lederer, W. J.

2008-01-01

357

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

E-print Network

Silicon Carbide (SiC) optical constants are fundamental inputs for radiative transfer models of astrophysical dust environments. However, previously published values contain errors and do not adequately represent the bulk physical properties of the cubic (beta) SiC polytype usually found around carbon stars. We provide new, uncompromised optical constants for beta- and alpha-SiC derived from single-crystal reflectance spectra and investigate quantitatively whether there is any difference between alpha- and beta-SiC that can be seen in infrared spectra and optical functions. Previous optical constants for SiC do not reflect the true bulk properties, and they are only valid for a narrow grain size range. The new optical constants presented here will allow narrow constraints to be placed on the grain size and shape distribution that dominate in astrophysical environments. In addition, our calculated absorption coefficients are much higher than laboratory measurements, which has an impact on the use of previous d...

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

2008-01-01

358

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

359

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

360

Light-trap design using multiple reflections and solid-angle attenuation - Application to a spaceborne electron spectrometer  

NASA Technical Reports Server (NTRS)

The design and performance of a new light trap for a spaceborne electron spectrometer are described. The light trap has a measured photon-rejection ratio of 2 x 10 exp -11, allowing only one in 5 x 10 exp 10 incident photons to reach the sensitive area of the instrument. This rejection is more than sufficient because the ambient UV in earth orbit requires a rejection no better than 10 exp -8 to maintain the photon interference to less than 10 count/s. The light trap uses triple reflections to keep most of the light passing through the entrance slit away from the sensitive area of the spectrometer. It is shown that the average reflectance of all the internal surfaces must be less than 0.006, which is consistent with the data on the black coating applied to all surfaces. The analysis makes it possible to compare the photon contributions of each of the internal reflecting areas and to estimate the effective scattering width of the metallic electrode edge.

Herrero, Federico A.

1992-01-01

361

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

362

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 µm. 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

363

Using confocal microscopy to characterize nanoplasmonic structures responsible for light transmission  

NASA Astrophysics Data System (ADS)

The optical properties of nanostructured metallic nanofilms have been extensively studied in last few years. It was observed, for a wide variety of structures an enhancement in the transmission that can be explained as resulting from surface plasmon polaritons (SPP) waves propagating at the interface between the metallic film and the surrounding dielectric and/or substrate. In this work we utilize confocal microscope images as a useful tool to characterize the optical response of a set of concentric nanorings in the presence of SPP waves. We show for the first time the influence of the metal thickness on the light intensity profile. Reflected and transmitted light for concentric nanorings were observed under excitation of different laser wavelengths (405-633nm) as well as white light. Microscopy imaging with polarized light showed not only the spatial pattern of the radiation transmitted through these apertures but also a significant dependence of these patterns on the film thickness. The behavior was theoretically analyzed via basic principles as well as numerical simulation with standard software. A possible explanation is describing each ring as a source of radiation formed by two dipole systems, one electric dipole aligned to the applied electric field and a second one, a magnetic dipole, associated to a loop-antenna having an azimuthally non-homogeneous current dependence. This preliminary model is an ongoing study which may be useful to explain the behavior of the transmitted light. Analysis also showed the potential of confocal microscope for imaging nanostructures as well as for quantitative information on SPP excitation.

Carvalho, Mariana T.; Bezerra, Marcel; Marega, Euclydes; Borges, Ben-Hur V.; Nunes, Frederico D.

2013-03-01

364

Dispositional reflections  

E-print Network

analysis suggests that the studied scholars enact these games to understand a more or less common object of knowledge, but also to constitute a more or less identifiable position in this given social space. Reflection on the ontological complicity between...

Brummans, Boris H. J. M.

2005-02-17

365

Theological Reflection.  

ERIC Educational Resources Information Center

The Adult Education with Theological Reflection program developed jointly by the Church of England and University College Chester is a postgraduate program for adult educators working in church contexts. The open learning, modular approach facilitates part-time study. (SK)

Ineson, Hilary; Deane-Drummond, Celia

1998-01-01

366

In vivo imaging of tumor angiogenesis using fluorescence confocal videomicroscopy.  

PubMed

Fibered confocal fluorescence in vivo imaging with a fiber optic bundle uses the same principle as fluorescent confocal microscopy. It can excite fluorescent in situ elements through the optical fibers, and then record some of the emitted photons, via the same optical fibers. The light source is a laser that sends the exciting light through an element within the fiber bundle and as it scans over the sample, recreates an image pixel by pixel. As this scan is very fast, by combining it with dedicated image processing software, images in real time with a frequency of 12 frames/sec can be obtained. We developed a technique to quantitatively characterize capillary morphology and function, using a confocal fluorescence videomicroscopy device. The first step in our experiment was to record 5 sec movies in the four quadrants of the tumor to visualize the capillary network. All movies were processed using software (ImageCell, Mauna Kea Technology, Paris France) that performs an automated segmentation of vessels around a chosen diameter (10 ?m in our case). Thus, we could quantify the 'functional capillary density', which is the ratio between the total vessel area and the total area of the image. This parameter was a surrogate marker for microvascular density, usually measured using pathology tools. The second step was to record movies of the tumor over 20 min to quantify leakage of the macromolecular contrast agent through the capillary wall into the interstitium. By measuring the ratio of signal intensity in the interstitium over that in the vessels, an 'index leakage' was obtained, acting as a surrogate marker for capillary permeability. PMID:24056503

Fitoussi, Victor; Faye, Nathalie; Chamming's, Foucauld; Clement, Olivier; Cuenod, Charles-Andre; Fournier, Laure S

2013-01-01

367

Multiple Reflections  

NSDL National Science Digital Library

This activity on multiple reflections is produced by the International Society for Optical Engineering, the Optical Society of America, and the Association of Universities for Research in Astronomy. Two plane rectangular mirrors, that meet on one edge, produce various reflection patterns. Students learn the relationship between the number of images produced and the orientation of the two mirrors. The site lists all necessary tools and materials and includes numerous helpful photographs and diagrams.

2009-01-13

368

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 reconstruction methods dedicated to this type of samples. However, these methods are applicable with monochromatic excitation only. The full description of matrix effects and geometrical effects for polychromatic X-ray photons in confocal geometry is a demanding task. In the present paper, this problem was overcome by the use of effective energy approximation. The reduction of the whole energy dimension into one effective value eliminates the necessity of integration over the primary beam energy range for a number of basic parameters. This simplification is attainable without loss of the accuracy of analysis. The proposed approach was validated by applying it to the reconstruction of element concentration depth profiles of stratified standard samples measured with tabletop confocal microbeam X-ray fluorescence setup and by comparing the obtained results of two independent algorithms. PMID:25307861

Wrobel, Pawel; Wegrzynek, Dariusz; Czyzycki, Mateusz; Lankosz, Marek

2014-11-18

369

Confocal Imaging of Biological Tissues Using Second Harmonic Generation  

SciTech Connect

A confocal microscopy imaging system was devised to selectively detect Second harmonic signals generated by biological tissues. Several types of biological tissues were examined using this imaging system, including human teeth, bovine blood vessels, and chicken skin. All these tissues generated strong second harmonic signals. There is considerable evidence that the source of these signals in tissue is collagen. Collagen, the predominant component of most tissues, is known to have second order nonlinear susceptibility. This technique may have diagnostic usefulness in pathophysiological conditions characterized by changes in collagen structure including malignant transformation of nevi, progression of diabetic complications, and abnormalities in wound healing.

Kim, B-M.; Stoller, P.; Reiser, K.; Eichler, J.; Yan, M.; Rubenchik, A.; Da Silva, L.

2000-03-06

370

Imaging microscopic viscosity with confocal scanning optical tweezers  

NASA Astrophysics Data System (ADS)

The techniques of confocal microscopy and optical tweezers have shown themselves to be powerful tools in biological and medical research. We combine these methods to develop a minimally invasive instrument that is capable of making hydrodynamic measurements more rapidly than is possible with other devices. This result leads to the possibility of making scanning images of the viscosity distribution of materials around biopolymer-producing cells, 100 × 100 images can be taken with 0.5-?m spatial resolution in 3 min. An image of the viscosity distribution around a pullulan-producing cell of Aureobasidium pullulans is shown as an example.

Nemet, Boaz A.; Shabtai, Yossef; Cronin-Golomb, Mark

2002-02-01

371

A miniature confocal Raman probe for endoscopic use  

NASA Astrophysics Data System (ADS)

Raman spectroscopy is a powerful tool for studying biochemical changes in the human body. We describe a miniature, confocal fibre optic probe intended to fit within the instrument channel of a standard medical endoscope. This probe has been optimized for the study of the carcinogenesis process of oesophageal malignancy. The optical design and fabrication of this probe is described including the anisotropic wet etching technique used to make silicon motherboards and jigs. Example spectra of PTFE reference samples are shown. Spectra with acquisition times as low as 2 s from resected oesophageal tissue are presented showing identifiable biochemical changes from various pathologies.

Day, J. C. C.; Bennett, R.; Smith, B.; Kendall, C.; Hutchings, J.; Meaden, G. M.; Born, C.; Yu, S.; Stone, N.

2009-12-01

372

Compact carbon monoxide sensor utilizing a confocal optical cavity.  

NASA Technical Reports Server (NTRS)

The carbon monoxide sensor discussed in this paper utilizes a unique confocal cavity which allows the complete system to be packaged in a small volume suitable for hand-held use. The optical system is the heart of the instrument with equal emphasis placed on the electronics support circuitry, consisting essentially of a thermal infrared pyroelectric detector and lock-in amplifier. The pyroelectric detector offers a major advantage over other thermal detectors, providing a signal-to-noise ratio and detectivity that remain nearly constant over the frequency range from dc to 2000 Hz. Since bias voltage is not required, low frequency noise is not generated in the detector.

Scott, B.; Magyar, J.; Weyant, R.; Hall, J.

1973-01-01

373

Confocal backscatter laser velocimeter with on-axis sensitivity.  

NASA Technical Reports Server (NTRS)

A confocal backscatter laser Doppler velocimeter (LDV) that measures two velocity components has been developed. This device requires only two incident beams polarized normally to one another. Moreover, the velocity components sensed are nearly orthogonal. The velocimeter employs a combined dual-scatter, local oscillator arrangement to obtain the bidirectional sensitivity. Two photodetectors are used, each sensing only one Doppler frequency proportional to one of the very nearly orthogonal velocity components. In addition, a single Bragg cell serves to frequency bias both velocity components in order to eliminate directional ambiguity. A differencing technique has also been incorporated to enhance the dual-scatter Doppler signal corresponding to the transverse velocity.

Orloff, K. L.; Logan, S. E.

1973-01-01

374

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

375

Reflectance standards at ultraviolet wavelengths  

NASA Astrophysics Data System (ADS)

Polytetrafluoroethylene (PTFE) is widely used in remote sensing applications requiring a diffuse reflectance standard for detector calibration. The bi-directional and directional-hemispherical reflectance properties of both pressed and sintered PTFE were measured at ultraviolet wavelengths to provide information for their use as standards in this spectral range. The reflectance decreases with decreasing wavelength for both geometries, and the ratio between the reflectances for these geometries remains constant for wavelengths from 300 nm to 400 nm.

Barnes, P. Yvonne; Nadal, Maria E.; Early, Edward A.

1999-09-01

376

Developing a confocal acoustic holography microscope for non-invasive 3D temperature and composition measurements.  

PubMed

A confocal acoustic holography microscope (CAHM) has been designed, simulated and partially verified experimentally to take holograms for non-invasive, three-dimensional measurements of a specimen's refractive indices from one view point. The designed and simulated prototype CAHM used a frequency of 2.25 MHz and measured sound speed changes of 16 m/s, temperature changes of 5 degrees C and had a spatial resolution of 660 microm. With future improvements utilizing the latest technologies such as two-dimensional array detectors, Micro-Electro-Mechanical Systems (MEMS), and acoustic lenses, resolutions of 1m/s, 0.5 degrees C, and 150 microm are expected. The CAHM is expected to have many useful applications, including non-invasive mass and heat transfer measurements in fluids and materials and as a medical diagnostic tool to non-intrusively visualize compositions and temperatures within the human body. PMID:19375860

Herring, Rodney A; Jacquemin, Peter; Sawicka, Barbara D; Atalick, Stefan

2009-06-01

377

Aerogel Track Morphology: Measurement, Three Dimensional Reconstruction and Particle Location using Confocal Laser Scanning Microscopy  

NASA Technical Reports Server (NTRS)

The Stardust spacecraft returned the first undoubted samples of cometary dust, with many grains embedded in the silica aerogel collector . Although many tracks contain one or more large terminal particles of a wide range of mineral compositions , there is also abundant material along the track walls. To help interpret the full particle size, structure and mass, both experimental simulation of impact by shots and numerical modeling of the impact process have been attempted. However, all approaches require accurate and precise measurement of impact track size parameters such as length, width and volume of specific portions. To make such measurements is not easy, especially if extensive aerogel fracturing and discoloration has occurred. In this paper we describe the application and limitations of laser confocal imagery for determination of aerogel track parameters, and for the location of particle remains.

Kearsley, A. T.; Ball, A. D.; Wozniakiewicz, P. A.; Graham, G. A.; Burchell, M. J.; Cole, M. J.; Horz, F.; See, T. H.

2007-01-01

378

Expanding the realm of fiber optic confocal sensing for probing position, displacement, and velocity  

SciTech Connect

We describe a fiber optic confocal sensor (FOCOS) system that uses an optical fiber and a lens to accurately detect the position of an object at, or close to, the image plane of the fiber tip. The fiber characteristics (diameter and numerical aperture) and optics (lens F and magnification) define the span and precision of the sensor and may be chosen to fit a desired application of position and displacement sensing. Multiple measurement points (i.e., fiber-tip images) may be achieved by use of multiple wavelengths in the fiber, so that each wavelength images the fiber at a different plane due to the chromatic dispersion of the optics. Further multiplexing may be achieved by adding fibers on the optical axis. A FOCOS with multiplexed fibers and wavelengths may also be used for velocity measurements.

Shafir, E.; Berkovic, G

2006-10-20

379

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

E-print Network

Silicon Carbide (SiC) optical constants are fundamental inputs for radiative transfer models of astrophysical dust environments. However, previously published values contain errors and do not adequately represent the bulk physical properties of the cubic (beta) SiC polytype usually found around carbon stars. We provide new, uncompromised optical constants for beta- and alpha-SiC derived from single-crystal reflectance spectra and investigate quantitatively whether there is any difference between alpha- and beta-SiC that can be seen in infrared spectra and optical functions. Previous optical constants for SiC do not reflect the true bulk properties, and they are only valid for a narrow grain size range. The new optical constants presented here will allow narrow constraints to be placed on the grain size and shape distribution that dominate in astrophysical environments. In addition, our calculated absorption coefficients are much higher than laboratory measurements, which has an impact on the use of previous data to constrain abundances of these dust grains.

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

2008-03-10

380

Application FT-NIR in rapid estimation of soluble solids content of intact kiwifruits by reflectance mode  

NASA Astrophysics Data System (ADS)

Nondestructive method of measuring soluble solids content (SSC) of kiwifruit was developed by Fourier transform near infrared (FT-NIR) reflectance and fiber optics. Also, the models describing the relationship between SSC and the NIR spectra of the fruit were developed and evaluated. To develop the models several different NIR reflectance spectra were acquired for each fruit from a commercial supermarket. Different spectra correction algorithms (standard normal variate (SNV), multiplicative signal correction (MSC)) were used in this work. The relationship between laboratory SSC and FT-NIR spectra of kiwifruits were analyzed via principle component regression (PCR) and partial least squares (PLS) regression method using TQ 6.2.1 quantitative software (Thermo Nicolet Co., USA). Models based on the different spectral ranges were compared in this research. The first derivative and second derivative were applied to all measured spectra to reduce the effects of sample size, light scattering, noise of instrument, etc. Different baseline correction methods were applied to improve the spectral data quality. Among them the second derivative method after baseline correction produced best noise removing capability and to obtain optimal calibration models. Total 480 NIR spectra were acquired from 120 kiwifruits and 90 samples were used to develop the calibration model, the rest samples were used to validate the model. Developed PLS model, which describes the relationship between SSC and NIR spectra, could predict SSC of 84 unknown samples with correlation coefficient of 0.9828 and SEP of 0.679 Brix.

Ying, Yibin; Lu, Huishan; Fu, Xiaping; Liu, Yande; Xu, Huirong; Yu, Haiyan

2005-11-01

381

Imaging theory of nonlinear second harmonic and third harmonic generations in confocal microscopy  

Microsoft Academic Search

The imaging theory of nonlinear second harmonic generation (SHG) and third harmonic generation (THG) in confocal microscopy\\u000a is presented in this paper. The nonlinear effect of SHG and THG on the imaging properties of confocal microscopy has been\\u000a analyzed in detail by the imaging theory. It is proved that the imaging process of SHG and THG in confocal microscopy, which

Zhilie Tang; Da Xing; Songhao Liu

2004-01-01

382

Optical axial scanning in confocal microscopy using an electrically tunable lens  

PubMed Central

This paper presents the use and characterization of an electrically focus tunable lens to perform axial scanning in a confocal microscope. Lateral and axial resolution are characterized over a >250 µm axial scan range. Confocal microscopy using optical axial scanning is demonstrated in epithelial tissue and compared to traditional stage scanning. By enabling rapid axial scanning, minimizing motion artifacts, and reducing mechanical complexity, this technique has potential to enhance in vivo three-dimensional imaging in confocal endomicroscopy. PMID:24575357

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

2014-01-01

383

Optical axial scanning in confocal microscopy using an electrically tunable lens.  

PubMed

This paper presents the use and characterization of an electrically focus tunable lens to perform axial scanning in a confocal microscope. Lateral and axial resolution are characterized over a >250 µm axial scan range. Confocal microscopy using optical axial scanning is demonstrated in epithelial tissue and compared to traditional stage scanning. By enabling rapid axial scanning, minimizing motion artifacts, and reducing mechanical complexity, this technique has potential to enhance in vivo three-dimensional imaging in confocal endomicroscopy. PMID:24575357

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

2014-02-01

384

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

PubMed

The data obtained in confocal Raman microscopy (CRM) depth profiling experiments with dry optics are subjected to significant distortions, including an artificial compression of the depth scale, due to the combined influence of diffraction, refraction, and instrumental effects that operate on the measurement. This work explores the use of (1) regularized deconvolution and (2) the application of simple rescaling of the depth scale as methodologies to obtain an improved, more precise, confocal response. The deconvolution scheme is based on a simple predictive model for depth resolution and the use of regularization techniques to minimize the dramatic oscillations in the recovered response typical of problem inversion. That scheme is first evaluated using computer simulations on situations that reproduce smooth and sharp sample transitions between two materials and finally it is applied to correct genuine experimental data, obtained in this case from a sharp transition (planar interface) between two polymeric materials. It is shown that the methodology recovers very well most of the lost profile features in all the analyzed situations. The use of simple rescaling appears to be only useful for correcting smooth transitions, particularly those extended over distances larger than those spanned by the operative depth resolution, which limits the strategy to the study of profiles near the sample surface. However, through computer simulations, it is shown that the use of water immersion objectives may help to reduce optical distortions and to expand the application window of this simple methodology, which could be useful, for instance, to safely monitor Fickean sorption/desorption of penetrants in polymer films/coatings in a nearly noninvasive way. PMID:21352656

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

2011-03-01

385

Embryonic Heart Morphogenesis from Confocal Microscopy Imaging and Automatic Segmentation  

PubMed Central

Embryonic heart morphogenesis (EHM) is a complex and dynamic process where the heart transforms from a single tube into a four-chambered pump. This process is of great biological and clinical interest but is still poorly understood for two main reasons. On the one hand, the existing imaging modalities for investigating EHM suffered from either limited penetration depth or limited spatial resolution. On the other hand, current works typically adopted manual segmentation, which was tedious, subjective, and time consuming considering the complexity of developing heart geometry and the large size of images. In this paper, we propose to utilize confocal microscopy imaging with tissue optical immersion clearing technique to image the heart at different stages of development for EHM study. The imaging method is able to produce high spatial resolution images and achieve large penetration depth at the same time. Furthermore, we propose a novel convex active contour model for automatic image segmentation. The model has the ability to deal with intensity fall-off in depth which is characterized by confocal microscopy images. We acquired the images of embryonic quail hearts from day 6 to day 14 of incubation for EHM study. The experimental results were promising and provided us with an insight view of early heart growth pattern and also paved the road for data-driven heart growth modeling. PMID:24454530

Gribble, Megan; Pertsov, Arkady M.; Shi, Pengcheng

2013-01-01

386

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, Jesús J; Romero-González, María E

2012-02-01

387

Darkfield Adapter for Whole Slide Imaging: Adapting a Darkfield Internal Reflection Illumination System to Extend WSI Applications  

PubMed Central

We present a new method for whole slide darkfield imaging. Whole Slide Imaging (WSI), also sometimes called virtual slide or virtual microscopy technology, produces images that simultaneously provide high resolution and a wide field of observation that can encompass the entire section, extending far beyond any single field of view. For example, a brain slice can be imaged so that both overall morphology and individual neuronal detail can be seen. We extended the capabilities of traditional whole slide systems and developed a prototype system for darkfield internal reflection illumination (DIRI). Our darkfield system uses an ultra-thin light-emitting diode (LED) light source to illuminate slide specimens from the edge of the slide. We used a new type of side illumination, a variation on the internal reflection method, to illuminate the specimen and create a darkfield image. This system has four main advantages over traditional darkfield: (1) no oil condenser is required for high resolution imaging (2) there is less scatter from dust and dirt on the slide specimen (3) there is less halo, providing a more natural darkfield contrast image, and (4) the motorized system produces darkfield, brightfield and fluorescence images. The WSI method sometimes allows us to image using fewer stains. For instance, diaminobenzidine (DAB) and fluorescent staining are helpful tools for observing protein localization and volume in tissues. However, these methods usually require counter-staining in order to visualize tissue structure, limiting the accuracy of localization of labeled cells within the complex multiple regions of typical neurohistological preparations. Darkfield imaging works on the basis of light scattering from refractive index mismatches in the sample. It is a label-free method of producing contrast in a sample. We propose that adapting darkfield imaging to WSI is very useful, particularly when researchers require additional structural information without the use of further staining. PMID:23520500

Kawano, Yoshihiro; Higgins, Christopher; Yamamoto, Yasuhito; Nyhus, Julie; Bernard, Amy; Dong, Hong-Wei; Karten, Harvey J.; Schilling, Tobias

2013-01-01

388

Darkfield adapter for whole slide imaging: adapting a darkfield internal reflection illumination system to extend WSI applications.  

PubMed

We present a new method for whole slide darkfield imaging. Whole Slide Imaging (WSI), also sometimes called virtual slide or virtual microscopy technology, produces images that simultaneously provide high resolution and a wide field of observation that can encompass the entire section, extending far beyond any single field of view. For example, a brain slice can be imaged so that both overall morphology and individual neuronal detail can be seen. We extended the capabilities of traditional whole slide systems and developed a prototype system for darkfield internal reflection illumination (DIRI). Our darkfield system uses an ultra-thin light-emitting diode (LED) light source to illuminate slide specimens from the edge of the slide. We used a new type of side illumination, a variation on the internal reflection method, to illuminate the specimen and create a darkfield image. This system has four main advantages over traditional darkfield: (1) no oil condenser is required for high resolution imaging (2) there is less scatter from dust and dirt on the slide specimen (3) there is less halo, providing a more natural darkfield contrast image, and (4) the motorized system produces darkfield, brightfield and fluorescence images. The WSI method sometimes allows us to image using fewer stains. For instance, diaminobenzidine (DAB) and fluorescent staining are helpful tools for observing protein localization and volume in tissues. However, these methods usually require counter-staining in order to visualize tissue structure, limiting the accuracy of localization of labeled cells within the complex multiple regions of typical neurohistological preparations. Darkfield imaging works on the basis of light scattering from refractive index mismatches in the sample. It is a label-free method of producing contrast in a sample. We propose that adapting darkfield imaging to WSI is very useful, particularly when researchers require additional structural information without the use of further staining. PMID:23520500

Kawano, Yoshihiro; Higgins, Christopher; Yamamoto, Yasuhito; Nyhus, Julie; Bernard, Amy; Dong, Hong-Wei; Karten, Harvey J; Schilling, Tobias

2013-01-01

389

Reflectivity Fingerprints  

NSDL National Science Digital Library

In this problem set, learners will analyze a table on the reflectivity of various substances to three kinds of wavelengths in order to answer a series of questions. Answer key is provided. This is part of Earth Math: A Brief Mathematical Guide to Earth Science and Climate Change.

390

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.

Exploratorium, The

2011-12-07

391

Nanoliter deposition unit for pipetting droplets of small volumes for Total Reflection X-ray Fluorescence applications  

NASA Astrophysics Data System (ADS)

A nanoliter droplet deposition unit was developed and characterized for application of sample preparation in TXRF. The droplets produced on quartz reflectors as well as on wafers show a good reproducibility, also the accuracy of the pipetted volume could be proved by a quantitative TXRF analysis using an external standard. The samples were found to be independent of rotation of the sample carrier. Angle scans showed droplet residue behavior, and the fluorescence signal is relatively invariant of the angle of incidence below the critical angle, which is useful for producing standards for external calibration for semiconductor surface contamination measurements by TXRF. Further it could be demonstrated that the nanoliter deposition unit is perfectly able to produce patterns of samples for applications like the quantification of aerosols collected by impactors.

Wastl, A.; Stadlbauer, F.; Prost, J.; Horntrich, C.; Kregsamer, P.; Wobrauschek, P.; Streli, C.

2013-04-01

392

Using Photoshop with images created by a confocal system.  

PubMed

Many pure colors and grayscales tones that result from confocal imaging are not reproducible to output devices, such as printing presses, laptop projectors, and laser jet printers. Part of the difficulty in predicting the colors and tones that will reproduce lies in both the computer display, and in the display of unreproducible colors chosen for fluorophores. The use of a grayscale display for confocal channels and a LUT display to show saturated (clipped) tonal values aids visualization in the former instance and image integrity in the latter. Computer monitors used for post-processing in order to conform the image to the output device can be placed in darkened rooms, and the gamma for the display can be set to create darker shadow regions, and to control the display of color. These conditions aid in visualization of images so that blacks are set to grayer values that are more amenable to faithful reproduction. Preferences can be set in Photoshop for consistent display of colors, along with other settings to optimize use of memory. The Info window is opened so that tonal information can be shown via readouts. Images that are saved as indexed color are converted to grayscale or RGB Color, 16-bit is converted to 8-bit when desired, and colorized images from confocal software is returned to grayscale and re-colorized according to presented methods so that reproducible colors are made. Images may also be sharpened and noise may be reduced, or more than one image layered to show colocalization according to specific methods. Images are then converted to CMYK (Cyan, Magenta, Yellow and Black) for consequent assignment of pigment percentages for printing presses. Changes to single images and multiple images from image stacks are automated for efficient and consistent image processing changes. Some additional changes are done to those images destined for 3D visualization to better separate regions of interest from background. Files are returned to image stacks, saved and then printed to best reveal colors, contrast, details and features. PMID:24052348

Sedgewick, Jerry

2014-01-01

393

Application of attenuated total reflectance Fourier transform infrared spectroscopy in the mineralogical study of a landslide area, Hungary  

NASA Astrophysics Data System (ADS)

This study demonstrates that the unpolarized attenuated total reflectance Fourier transform infrared spectroscopy (ATR FTIR) is a practical and quick tool to distinguish different types of sediments in landslide-affected areas, and potentially other types of physical environments too. Identification and quantification of minerals by ATR FTIR is implemented on a set of powdered natural sediments from a loess landslide (Kulcs, Hungary). A protocol including sample preparation, analytical conditions and evaluation of sediment ATR spectra is outlined in order to identify and estimate major minerals in sediments. The comparison of the defined FTIR parameters against qualitative and quantitative results of X-ray diffraction and thermal analysis was used to validate the use of ATR FTIR spectroscopy for the considered sediments. The infrared band areas and their ratios (water/carbonates; silicates/carbonates; kaolinite) appear to be the most sensitive parameters to identify strongly weathered sediments such as paleosols and red clays which most likely facilitate sliding and could form sliding zones. The effect of grain size and orientation of anisotropic minerals on the wave number and intensity of some major absorption bands is also discussed.

Udvardi, Beatrix; Kovács, István János; Kónya, Péter; Földvári, Mária; Füri, Judit; Budai, Ferenc; Falus, György; Fancsik, Tamás; Szabó, Csaba; Szalai, Zoltán; Mihály, Judith

2014-11-01

394

Reliability of internal prediction/estimation and its application. I. Adaptive action selection reflecting reliability of value function.  

PubMed

This article proposes an adaptive action-selection method for a model-free reinforcement learning system, based on the concept of the 'reliability of internal prediction/estimation'. This concept is realized using an internal variable, called the Reliability Index (RI), which estimates the accuracy of the internal estimator. We define this index for a value function of a temporal difference learning system and substitute it for the temperature parameter of the Boltzmann action-selection rule. Accordingly, the weight of exploratory actions adaptively changes depending on the uncertainty of the prediction. We use this idea for tabular and weighted-sum type value functions. Moreover, we use the RI to adjust the learning coefficient in addition to the temperature parameter, meaning that the reliability becomes a general basis for meta-learning. Numerical experiments were performed to examine the behavior of the proposed method. The RI-based Q-learning system demonstrated its features when the adaptive learning coefficient and large RI-discount rate (which indicate how the RI values of future states are reflected in the RI value of the current state) were introduced. Statistical tests confirmed that the algorithm spent more time exploring in the initial phase of learning, but accelerated learning from the midpoint of learning. It is also shown that the proposed method does not work well with the actor-critic models. The limitations of the proposed method and its relationship to relevant research are discussed. PMID:15312837

Sakaguchi, Yutaka; Takano, Mitsuo

2004-09-01

395

Experiences of exclusion when living on a ventilator: reflections based on the application of Julia Kristeva's philosophy to caring science.  

PubMed

The research presented in this work represents reflections in the light of Julia Kristeva's philosophy concerning empirical data drawn from research describing the everyday life of people dependent on ventilators. It also presents a qualitative and narrative methodological approach from a person-centred perspective. Most research on home ventilator treatment is biomedical. There are a few published studies describing the situation of people living at home on a ventilator but no previous publications have used the thoughts in Kristeva's philosophy applied to this topic from a caring science perspective. The paper also addresses what a life at home on a ventilator may be like and will hopefully add some new aspects to the discussion of philosophical issues in nursing and the very essence of care. Kristeva's philosophy embraces phenomena such as language, abjection, body, and love, allowing her writings to make a fruitful contribution to nursing philosophy in that they strengthen, expand, and deepen a caring perspective. Moreover, her writings about revolt having the power to create hope add an interesting aspect to the work of earlier philosophers and nursing theorists. PMID:21143574

Lindahl, Berit

2011-01-01

396

IOP from reflectance measurements to obtain the Kd coefficient: application to the Gabon and Congo coastal waters  

NASA Astrophysics Data System (ADS)

During the "Optic-Congo" oceanographic survey which took place in 2005 on board the "Beautemp-Beaupré" SHOM vessel, different optical measurements of the surface water were acquired using a TRIOS radiance sensor fixed onboard a mini-catamaran. Hydrological measurements (CTD, fluorescence, attenuation, scattering) and water samples were simultaneously collected in order to measure SPM, Chlorophyll-a and CDOM concentrations. Four types of surface water colours (blue, green-yellow, dark and brown) were identified. The main characteristics of these waters were the very low Chlorophyll-a concentrations for this period of the year (March), and the very high CDOM concentrations along the Congo coast, and particularly in the turbid plume of the Congo River. The attenuation and scattering measurements highlighted the predominance of organic matter at the water surface. These observations were documented using a beam electron microscope and by microanalysis. This data set was used to classify the water bodies along the Gabon and Congo coasts. We propose here to use the remote sensing reflectance (Rrs) measurements to invert the IOP (absorption (a) and backscattering (bb)) using the WASI numerical bio-optical model. The model is iterative: the Rrs WASI simulations are computed given initial values of ocean constituents' concentrations and iteratively adjusted to the Rrs in-situ measurements. The IOP computations are satisfying when the correlations between simulated and measured Rrs are optimized. Then, the attenuation coefficients (Kd) are computed from the IOP coefficients. These results are compared with measurements of Ku carried out during the survey.

Schmeltz, M.; Froidefond, J.-M.; Jourdain, F.; Martiny, N.

2009-08-01

397

Validation and application of a thermal-optical reflectance (TOR) method for measuring black carbon in loess sediments.  

PubMed

Three techniques were used to measure black carbon (BC) in samples from Chinese loess-paleosol sequences. The results obtained by (1) chemo-thermal oxidation (CTO, performed two ways), (2) acid dichromate oxidation (Cr2O7), and (3) thermal-optical reflectance (TOR) were intercompared because prior studies have shown that the methods can yield disparate results. BC concentrations did vary among the methods, most likely because they measured different components of the BC continuum, but the high-temperature BC (soot) determined by CTO was correlated with the BC and soot obtained by TOR. The CTO and TOR methods both yielded statistically significant linear relationships for loess and lake sediments that had incremental additions of a standard (SRM-1649a). The results also showed that charred material was more abundant in these test sediments than soot carbon. Data for BC in Luochuan loess generated using TOR showed a trend similar to that of magnetic susceptibility, that is, high BC and large susceptibilities during the last interglacial and low values for both variables in the last glacial. The results thus indicate that the TOR method is well suited for studies of sedimentary materials and that more biomass burned during the last interglacial than in the last glacial. PMID:23395362

Zhan, Changlin; Han, Yongming; Cao, Junji; Wei, Chong; Zhang, Jiaquan; An, Zhisheng

2013-06-01

398

Defect Band Luminescence Intensity Reversal as Related to Application of Anti-Reflection Coating on mc-Si PV Cells: Preprint  

SciTech Connect

Photoluminescence (PL) imaging is widely used to identify defective regions within mc-Si PV cells. Recent PL imaging investigations of defect band luminescence (DBL) in mc-Si have revealed a perplexing phenomenon. Namely, the reversal of the DBL intensity in various regions of mc-Si PV material upon the application of a SiNx:H anti-reflective coating (ARC). Regions with low DBL intensity before ARC application often exhibit high DBL intensity afterwards, and the converse is also true. PL imaging alone cannot explain this effect. We have used high resolution cathodoluminescence (CL) spectroscopy and electron beam induced current (EBIC) techniques to elucidate the origin of the DBL intensity reversal. Multiple sub-bandgap energy levels were identified that change in peak position and intensity upon the application of the ARC. Using this data, in addition to EBIC contrast information, we provide an explanation for the DBL intensity reversal based on the interaction of the detected energy levels with the SiNx:H ARC application. Multiple investigations have suggested that this is a global problem for mc-Si PV cells. Our results have the potential to provide mc-Si PV producers a pathway to increased efficiencies through defect mitigation strategies.

Guthrey, H.; Johnston, S.; Yan, F.; Gorman, B.; Al-Jassim, M.

2012-06-01

399

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.

400

Local delivery of fluorescent dye for fiber-optics confocal microscopy of the living heart  

PubMed Central

Fiber-optics confocal microscopy (FCM) is an emerging imaging technology with various applications in basic research and clinical diagnosis. FCM allows for real-time in situ microscopy of tissue at sub-cellular scale. Recently FCM has been investigated for cardiac imaging, in particular, for discrimination of cardiac tissue during pediatric open-heart surgery. FCM relies on fluorescent dyes. The current clinical approach of dye delivery is based on systemic injection, which is associated with high dye consumption, and adverse clinical events. In this study, we investigated approaches for local dye delivery during FCM imaging based on dye carriers attached to the imaging probe. Using three-dimensional confocal microscopy, automated bench tests, and FCM imaging we quantitatively characterized dye release of carriers composed of open-pore foam only and foam loaded with agarose hydrogel. In addition, we compared local dye delivery with a model of systemic dye delivery in the isolated perfused rodent heart. We measured the signal-to-noise ratio (SNR) of images acquired in various regions of the heart. Our evaluations showed that foam-agarose dye carriers exhibited a prolonged dye release vs. foam-only carriers. Foam-agarose dye carriers allowed reliable imaging of 5–9 lines, which is comparable to 4–8 min of continuous dye release. Our study in the living heart revealed that the SNR of FCM images using local and systemic dye delivery is not different. However, we observed differences in the imaged tissue microstructure with the two approaches. Structural features characteristic of microvasculature were solely observed for systemic dye delivery. Our findings suggest that local dye delivery approach for FCM imaging constitutes an important alternative to systemic dye delivery. We suggest that the approach for local dye delivery will facilitate clinical translation of FCM, for instance, for FCM imaging during pediatric heart surgery.

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

2014-01-01

401

Synchrotron Infrared Confocal Microspectroscopical Detection of Heterogeneity Within Chemically Modified Single Starch Granules  

SciTech Connect

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

Wetzel, D.; Shi, Y; Reffner, J

2010-01-01

402

Confocal spectroscopy of InGaN LED structures  

NASA Astrophysics Data System (ADS)

Photoluminescence of InGaN structures for green light-emitting diodes (LEDs) with multiple quantum wells as an active medium was studied with spatial and spectral resolution using confocal microscopy. Bright spots of ~200 nm diameter were observed. Emission from these bright areas was up to 8 times more intense than from the rest of the sample surface and the band peak position in these areas was blueshifted with respect to the band position in the background surface of lower photoluminescence intensity. The data on emission properties in bright and dark areas and the dependence of these properties on the excitation power density were interpreted by assuming inhomogeneous distribution of defects acting as nonradiative recombination centres.

Dobrovolskas, D.; Mickevi?ius, J.; Kuokštis, E.; Tamulaitis, G.; Shur, M.; Shatalov, M.; Yang, J.; Gaska, R.

2011-04-01

403

The free-electron laser in a symmetrical confocal resonator  

NASA Technical Reports Server (NTRS)

A tapered wiggler is used in a FEL oscillator to improve the saturation efficiency. During signal buildup the tapered wiggler does not provide optimum phase synchronism between the electron beam and the electromagnetic wave, resulting in an appreciable loss in small-signal gain. This problem can be ameliorated by using a multicomponent wiggler, which is a combination of a uniform wiggler and a tapered section. During buildup, gain is primarily contributed by the linear element, and at high power levels the gain and efficiency are enhanced by the taper. Ideally, one would like to have the optical waist location near the linear section at small-signal levels and at near the tapered section at high power levels. Placing the FEL in a symmetrical confocal resonator approaches this desired effect automatically since it has the unique characteristic that a stable mode exists for all locations of the waist of a Gaussian beam along the axis of the interferometer.

Ozcan, Meric; Pantell, Richard H.

1993-01-01

404

Multifocus confocal Raman microspectroscopy for rapid single-particle analysis  

NASA Astrophysics Data System (ADS)

We have developed a multifocus confocal Raman microspectroscopy system that allows simultaneous analyses of ~80 individual biological or airborne microparticles based on a precise image-guided technique. Multiple individual particles adhered in random positions on a coverslip were illuminated by a multifocus excitation pattern formed by rapidly steering a single laser beam with a pair of galvo-mirrors, and their Raman scatterings were synchronously projected with another galvo-mirror to different rows of a CCD chip for parallel spectroscopic analyses. We show that this technique can be used to rapidly identify single airborne particles or bacteria collected on a slide and to monitor germination dynamics of multiple bacterial spores in real-time.

Kong, Lingbo; Zhang, Pengfei; Setlow, Peter; Li, Yong-Qing

2011-12-01

405

Laser confocal feedback tomography and nano-step height measurement  

PubMed Central

A promising method for tomography and step height measurement is proposed, which combines the high sensitivity of the frequency-shifted feedback laser and the axial positioning ability of confocal microscopy. By demodulating the feedback-induced intensity modulation signals, the obtained amplitude and phase information are used to respectively determine the coarse and fine measurement of the samples. Imaging the micro devices and biological samples by the demodulated amplitude, this approach is proved to be able to achieve the cross-sectional image in highly scattered mediums. And then the successful height measurement of nano-step on a glass-substrate grating by combination of both amplitude and phase information indicates its axial high resolution (better than 2?nm) in a non-ambiguous range of about ten microns. PMID:24145717

Tan, Yidong; Wang, Weiping; Xu, Chunxin; Zhang, Shulian

2013-01-01

406

Confocal laser endomicroscopy in inflammatory bowel diseases: Dream or reality?  

PubMed Central

Confocal laser endomicroscopy (CLE) is a newly introduced procedure that provide real-time, high-resolution imaging of the gastrointestinal mucosa during endoscopy, allowing the visualization of the pathology of the mucosal epithelium with its cellular and subcellular structures. Recently, the use of CLE was reported in the study of colonic mucosa in patients with inflammatory bowel diseases and in particular in patients affected by ulcerative colitis. CLE has the potential to have an important role in management of inflammatory bowel diseases (IBD) patients as it can be used to assess the grading of colitis and in detection of microscopic colitis in endoscopically silent segments. Moreover, CLE can be used in surveillance programs especially in high-risk patients. Finally, CLE has been effectively used in diagnosing a biliary dysplasia/neoplasia in patients with primary sclerosing cholangitis, a pathological condition frequently associated with IBD, with a coexisting bile duct stricture. PMID:24039350

De Palma, Giovanni Domenico; Rispo, Antonio

2013-01-01

407

Spatial resolution of confocal XRF technique using capillary optics  

PubMed Central

XRF (X-ray fluorescence) is a powerful technique for elemental analysis with a high sensitivity. The resolution is presently limited by the size of the primary excitation X-ray beam. A test-bed for confocal-type XRF has been developed to estimate the ultimate lateral resolution which could be reached in chemical mapping using this technique. A polycapillary lens is used to tightly focus the primary X-ray beam of a low power rhodium X-ray source, while the fluorescence signal is collected by a SDD detector through a cylindrical monocapillary. This system was used to characterize the geometry of the fluorescent zone. Capillary radii ranging from 50 ?m down to 5 ?m were used to investigate the fluorescence signal maximum level This study allows to estimate the ultimate resolution which could be reached in-lab or on a synchrotron beamline. A new tool combining local XRF and scanning probe microscopy is finally proposed. PMID:23758858

2013-01-01

408

Quantification of transendothelial migration using three-dimensional confocal microscopy.  

PubMed

Migration of cells across endothelial barriers, termed transendothelial migration (TEM), is an important cellular process that underpins the pathology of many disease states including chronic inflammation and cancer metastasis. While this process can be modeled in vitro using cultured cells, many model systems are unable to provide detailed visual information of cell morphologies and distribution of proteins such as junctional markers, as well as quantitative data on the rate of TEM. Improvements in imaging techniques have made microscopy-based assays an invaluable tool for studying this type of detailed cell movement in physiological processes. In this chapter, we describe a confocal microscopy-based method that can be used to assess TEM of both leukocytes and cancer cells across endothelial barriers in response to a chemotactic gradient, as well as providing information on their migration into a subendothelial extracellular matrix, designed to mimic that found in vivo. PMID:21748676

Cain, Robert J; d'Água, Bárbara Borda; Ridley, Anne J

2011-01-01

409

Zinc and cadmium accumulation in single zebrafish ( Danio rerio) embryos — A total reflection X-ray fluorescence spectrometry application  

NASA Astrophysics Data System (ADS)

Trace metals such as Cadmium (Cd) and Zinc (Zn) are known to exhibit adverse effects on many aquatic organisms including early life stages of fish. In contact with contaminated sediment, fish eggs and embryos may be exposed to metals via the water phase as well as via direct contact with contaminated particles. This may result in body burdens that are difficult to predict and may vary according to individual micro scale exposure conditions. The highly sensitive total reflection X-ray fluorescence spectrometry (TXRF) may provide a tool to analyse individual embryos for internal contaminant concentrations and thus helps to develop a better understanding of dose-response relationships. To test this hypothesis, embryos of Danio rerio were exposed to Cd and Zn spiked sediment in different treatments applying an ion exchange resin for modification of bioavailable concentrations. The TXRF analysis indicated individual embryos with dramatically enhanced exposure compared to other individuals despite uniform exposure conditions on a macro scale. Ion exchanger reduced embryo Zn concentrations to values close to control value with a comparably low standard deviation. Cadmium concentrations in embryos were in the range of 4000 to 7000 µg/g with a median of 5740 µg/g. A commercial ion exchanger reduced individual body burdens by a factor 50 to 100. Individual peak body burdens of up to 3160 µg/g were accompanied by reduced weight of the fish eggs due to early death i.e. coagulation. The investigation of exposure and effects on an individual-based scale may significantly help to reduce uncertainty and inconsistencies occurring in conventional analysis of pooled fish embryo samples.

Mages, Margarete; Bandow, Nicole; Küster, Eberhard; Brack, Werner; von Tümpling, Wolf

2008-12-01

410

Weekly Reflections  

NSDL National Science Digital Library

About once a week, which approximately corresponds to each chapter covered, students are required to write a 2-3 paragraph reflection on the material covered in class. They may use information found in the book, or their experiences during lecture and lab, but they need to discuss their thoughts on the material. This written assignment encourages students to think more deeply about the material discussed, as well as to become more comfortable with the writing process.

Rutzky, Sara M.

411

Single-shot depth-section imaging through chromatic slit-scan confocal microscopy  

E-print Network

into two categories: transverse x, y and depth z scanning. The scan- ning technique dictates the speedSingle-shot depth-section imaging through chromatic slit-scan confocal microscopy Paul C. Lin, Pang by incorporating a slit-scan confocal technique into the system. A system using a 100 objective obtained a depth

Fainman, Yeshaiahu

412

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

E-print Network

Description and performance of a highly versatile, low-cost fiber-optic confocal Raman microscope C for publication 29 September 1995 A versatile fiber-optic confocal Raman microscope has been developed. Fiber optics provide remote capabilities for the microscope and the ability to use multiple excitation sources

Myrick, Michael Lenn

413

Position estimation of fluorescent probes in a confocal microscope Sean B. Andersson  

E-print Network

Position estimation of fluorescent probes in a confocal microscope Sean B. Andersson Abstract-- Measurements of fluorescence intensity from an isolated fluorescing probe in a confocal microscope can. The resolution of an optical microscope is limited by the Rayleigh criterion to 1.22 2N.A. where

Andersson, Sean B.

414

Cross structured illumination for high speed high resolution line scanning confocal microscopy  

Microsoft Academic Search

Previous research presented the structured illumination confocal scanning microscope (SICSM) so as to improve the lateral resolution of the confocal microscope. However, the image acquisition speed of the SICSM is very slow and also an alignment error due to the mechanical rotation of a grating and a slit can easily occur. As a theoretical study, in this paper we propose

MyoungKi Ahn; Taejoong Kim; YoungDuk Kim; DaeGab Gweon; Jun-Hee Lee

2011-01-01

415

Fiber-based confocal microscope for cryogenic spectroscopy Alexander Hgele,1,a  

E-print Network

Fiber-based confocal microscope for cryogenic spectroscopy Alexander Högele,1,a Stefan Seidl,1. Warburton3 1 Center for NanoScience, Department für Physik, Ludwig-Maximilians-Universität, Geschwister and performance of a fiber-based confocal microscope for cryogenic operation. The microscope combines positioning

Ludwig-Maximilians-Universität, München

416

In vivo intravital endoscopic confocal fluorescence microscopy of normal and acutely injured rat lungs  

Microsoft Academic Search

We present a new lung imaging technique based on endoscopic confocal fluorescence microscopy (ECFM), which is a new method that is able to provide cellular and structural assessment of living tissue using a small confocal probe in direct contact with the visceral pleura. To observe distal airspace structure and cellular condition in normal and injured lungs (hyperoxic and bleomycin challenged),

Frederic Chagnon; Clement Fournier; Paul G Charette; Luc Moleski; Marcel D Payet; Leland G Dobbs; Olivier Lesur

2010-01-01

417

Computer-aided identification of ovarian cancer in confocal microendoscope images  

E-print Network

Computer-aided identification of ovarian cancer in confocal microendoscope images Saurabh of ovarian cancer is introduced. The cellular-level struc- ture present in ex vivo confocal microendoscope, 2008. 1 Introduction Ovarian cancer is the fifth most common cancer in women. According to statistics

Gmitro, Arthur F.

418

Automated Texture-Based Identification of Ovarian Cancer in Confocal Microendoscope Images  

E-print Network

Automated Texture-Based Identification of Ovarian Cancer in Confocal Microendoscope Images Saurabh for the early detection of ovarian cancer. The purpose of this study was to develop a computer-aided system to facilitate the identification of ovarian cancer from digital images captured with the confocal microendoscope

Gmitro, Arthur F.

419

In vivo imaging of ovarian tissue using a novel confocal microlaparoscope  

E-print Network

the surgeon to identify early-stage ovarian cancer. Key words: confocal microendoscopy, fluorescence confocal imaging, optical biopsy, ovarian cancer Cite this article as: Tanbakuchi AA, Udovich JA, Rouse AR, et al increases to 92%. The overall preva- lence of ovarian cancer is relatively low (1.7% lifetime risk). However

Gmitro, Arthur F.

420

In Vivo Confocal Scanning Laser Microscopy of Human Skin: Melanin Provides Strong Contrast  

Microsoft Academic Search

Confocal scanning laser microscopy of live human skin was performed to investigate the correlation of in vivo cellular and morphologic features to histology, the effect of wavelength on imaging, and the role of melanin as a contrast agent. We built a video-rate confocal scanning laser microscope for in viva imaging of human skins. Using a 100 × microscope objective, we

Milind Rajadhyaksha; Melanie Grossman; Dina Esterowitz; Robert H. Webb; R. Rox Anderson

1995-01-01

421

Application of VNIR diffuse reflectance spectroscopy for mapping of organic matter redistribution due to erosion and deposition processes  

NASA Astrophysics Data System (ADS)

Visible and near-infrared (VNIR) diffuse reflectance spectroscopy is cost- and time-effective and environmentally friendly techniques method used for prediction of soil properties. Study was performed on the soils from the agricultural land from the municipalities of Brumovice (209 samples), Sedlcany (67 samples), Vidim (74 samples) and Zelezna (32 samples). In Brumovice original soil type was Haplic Chernozem on loess, which was due to erosion changed into Regosol (steep parts) and Colluvial soil (base slope and the tributary valley). A similar process has been described at other three locations Sedlcany, Vidim and Zelezna where the original soil types were Haplic Cambisol on gneiss, Haplic Luvisol on loess and Haplic Cambisol on shales, respectively. The goal of the study was to evaluate relationship between soil spectra curves and organic matter content to provide an efficient tool for mapping of organic matter redistribution (i.e. soil degradation) due to erosion and deposition processes. Samples were taken from the topsoil within regular grid covering studied areas. The soil spectra curves (of air dry soil and sieved using 0.2 mm sieve) were measured in the laboratory using spectrometer FieldSpec®3 (350 - 2 500 nm). Partial least squares regression (PLSR) was used for modeling of the relationship between spectra and measured organic matter content. Prediction ability was evaluated using the R2, root mean square error (RMSE). The results showed the best prediction of the organic matter content was obtained for soil samples from Brumovice (R2 = 0.78, RMSE = 0.15) and decreased as follows: Zelezna (R2 = 0.68, RMSE = 0.23), Sedlcany (R2 = 0.64, RMSE = 0.18) and Vidim (R2 = 0.61, RMSE = 0.12). In general, the results confirmed that the measurement of soil spectral characteristics is a promising technology for a digital soil mapping and predicting studied soil properties. Acknowledgment: Authors acknowledge the financial support of the Ministry of Agriculture of the Czech Republic (grant No. QJ1230319).

Klement, Ales; Brodsky, Lukas; Jaksik, Ondrej; Fer, Miroslav; Kodesova, Radka

2014-05-01

422

Development of a high spectral resolution lidar based on confocal Fabry-Perot spectral filters.  

PubMed

The high spectral resolution lidar (HSRL) instrument described in this paper utilizes the fundamental and second-harmonic output from an injection seeded Nd:YAG laser as the laser transmitter. The light scattered in the atmosphere is collected using a commercial Schmidt-Cassegrain telescope with the optical receiver train first splitting the fundamental and second-harmonic return signal with the fundament light monitored using an avalanche photodiode. The second-harmonic return signal is mode matched into a tunable confocal Fabry-Perot (CFP) interferometer with a free spectral range of 7.5 GHz and a finesse of 50.7 (312) at 532 nm (1064 nm) placed in the optical receiver for spectrally filtering the molecular and aerosol return signals. The light transmitted through the CFP is used to monitor the aerosol return signal while the light reflected from the CFP is used to monitor the molecular return signal. Data collected with the HSRL are presented and inversion results are compared to a co-located solar radiometer, demonstrating the successful operation of the instrument. The CFP-based filtering technique successfully employed by this HSRL instrument is