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1

[Clinical applications of reflectance confocal microscopy in the management of cutaneous tumors].  

PubMed

Reflectance confocal microscopy is a noninvasive tool that allows skin cells and structure to be imaged in real time. The technique has been used to assess benign and malignant lesions and has shown great potential in basic research and clinical dermatology. As might be expected, it also has great potential in longitudinal clinical studies and in the evaluation of dynamic processes such as those that occur after exposure to UV radiation or during the tumor response to noninvasive therapy. This article briefly describes the fundamental aspects and basic principles of reflectance confocal microscopy and discusses its clinical applications essentially in the management of cutaneous tumors. We also consider the limitations of the technique associated with the optical properties of the skin, with instrumentation, and with interpretation of the images. PMID:18682165

González, S

2008-09-01

2

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

3

Confocal MXRF in environmental applications.  

PubMed

In this review we highlight the performance of confocal micro X-ray fluorescence (CMXRF) for application in environmental science, citing contributions from recent studies (2008-2010). In CMXRF the use of focusing and collecting optics enables discrimination of the origin of fluorescence photons in three dimensions. It thereby enables simple and direct three dimensional imaging, and also the removal of unwanted signal contribution either from the depth of the sample or from its surface. By limiting the area of origin of fluorescence signal CMXRF can simplify quantitative approaches. PMID:21455655

Fittschen, Ursula Elisabeth Adriane; Falkenberg, Gerald

2011-04-01

4

Confocal Blue Reflectance Imaging in Type 2 Idiopathic Macular Telangiectasia  

Microsoft Academic Search

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

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

2008-01-01

5

Straightness measurements by use of a reflection confocal optical system.  

PubMed

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

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

1999-09-01

6

Pupil engineering for a confocal reflectance line-scanning microscope  

NASA Astrophysics Data System (ADS)

Confocal reflectance microscopy may enable screening and diagnosis of skin cancers noninvasively and in real-time, as an adjunct to biopsy and pathology. Current confocal point-scanning systems are large, complex, and expensive. A confocal line-scanning microscope, utilizing a of linear array detector can be simpler, smaller, less expensive, and may accelerate the translation of confocal microscopy in clinical and surgical dermatology. A line scanner may be implemented with a divided-pupil, half used for transmission and half for detection, or with a full-pupil using a beamsplitter. The premise is that a confocal line-scanner with either a divided-pupil or a full-pupil will provide high resolution and optical sectioning that would be competitive to that of the standard confocal point-scanner. We have developed a confocal line-scanner that combines both divided-pupil and full-pupil configurations. This combined-pupil prototype is being evaluated to determine the advantages and limitations of each configuration for imaging skin, and comparison of performance to that of commercially available standard confocal point-scanning microscopes. With the combined configuration, experimental evaluation of line spread functions (LSFs), contrast, signal-to-noise ratio, and imaging performance is in progress under identical optical and skin conditions. Experimental comparisons between divided-pupil and full-pupil LSFs will be used to determine imaging performance. Both results will be compared to theoretical calculations using our previously reported Fourier analysis model and to the confocal point spread function (PSF). These results may lead to a simpler class of confocal reflectance scanning microscopes for clinical and surgical dermatology.

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

2011-02-01

7

Application of Confocal and Spectrally Resolved Techniques to Scanning Laser Photoluminescence Microscopy  

Microsoft Academic Search

Both confocal microscopes and photoluminescence wafer mapping systems are well-developed technologies, however the application of confocal techniques to photoluminescence microscopy is not common in the literature. While developing this microscope a novel design for a spectrally-resolved detection arm was implemented. The microscope shows full confocal capabilities in reflected light operation, good spectral sensitivity in the visible region and a range

John William Bowron

1993-01-01

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

Confocal reflectance imaging of excised malignant human bladder biopsies  

NASA Astrophysics Data System (ADS)

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

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

2004-08-01

10

Confocal Endomicroscopy: Instrumentation and Medical Applications  

PubMed Central

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

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

2013-01-01

11

Dual mode fibre bundle confocal endomicroscopy: combining reflectance and fluorescence imaging  

NASA Astrophysics Data System (ADS)

Commercial endomicroscopes operate in fluorescence mode only and so require the application of contrast agents. As an alternative, we describe a fibre bundle confocal endomicroscope which acquires simultaneous and co-registered fluorescence and reflectance mode images. A combination of polarisation selection and refractive index matching is used to minimise back-reflections from the fibre bundle. We show preliminary results from the system using phantoms and tissue samples.

Hughes, Michael; Simaiaki, Vasiliki; Chang, Tou Pin; Yang, Guang-Zhong

2013-06-01

12

Reflectance confocal microscopy for in vivo skin imaging.  

PubMed

Reflectance confocal microscopy (RCM) is a novel noninvasive technique for "in vivo" examination of the skin. In a confocal microscope, near- infrared light from a diode laser is focused on a microscopic skin target. As this light passes between cellular structures having different refraction indexes, it is naturally reflected, and this reflected light is then captured and recomposed into a two-dimensional gray scale image by computer software. Focusing the microscope (adjusting the focal point on the z-axis) allows images to be obtained of different levels within the skin. Commercially available microscope systems of this type can create images with enough detail for use in histological analysis. The first investigations using these microscopes served to identify the appearance of the various cell populations living in the different layers of normal skin. Today, the main interest has become focused on the use of these microscopes as a diagnostic tool: a means of investigating benign and malignant tumors of melanocytes and keratinocytes, and, more importantly, the findings of this field of study can be used to develop a diagnostic algorithm which would be not only highly sensitive but specific as well. The aim of the paper is to provide an updated literature review and an in-depth critique of the state-of-the-art of RCM for skin cancer imaging with a critical discussion of the possibilities and limitations for clinical use. PMID:19067964

Calzavara-Pinton, Piergiacomo; Longo, Caterina; Venturini, Marina; Sala, Raffaella; Pellacani, Giovanni

13

Improved contrast by modal illumination in scanning reflectance confocal microscopy  

NASA Astrophysics Data System (ADS)

Scanning reflectance confocal microscopy (SRCM) is a flexible technology that provides cellular resolution images of tissue morphology with tailored resolutions and fields of view. However, how accurately an object is represented, in other words its fidelity, is critical in medical imaging and is not represented simply by optical resolution. In this work we characterize the SRCMs fidelity of images derived within turbid media. We present theoretical and experimental results showing the improved fidelity when using modal illumination. We investigated the use of TEM10 illumination and a novel implementation of Nomarski differential-interference-contrast (DIC). Using a repeatable, stable turbid phantom the system fidelity was characterized.

Glazowski, Christopher; Zavislan, James

2012-02-01

14

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

15

The combination of multiphoton and reflected confocal microscopy for cornea imaging  

NASA Astrophysics Data System (ADS)

The purpose of this work is to demonstrate the combination of reflective confocal microscopy and multiphoton microscopy and its application in imaging cornea. The difficulty of optically imaging the highly translucent cornea has prevented the development of an effective non-invasive system for the clinical monitoring of the physiological or pathological states of corneas. In this work, we combine reflective confocal microscopy with multiphoton microscopy to demonstrate the potential of our methodology in the minimally invasive imaging of the cornea. The visible reflection signals from cornea can provide structural information of interfaces of different refractive indices while the multiphoton signals generated from the use of near infrared excitation allows deep tissue penetration and reduced photo-damage. In multiphoton imaging, the second harmonic generation (SHG) signal is used to detect collagen in the stroma of the cornea, and the reflective confocal imaging allows detection of the cellular components located in the epithelium. The combination of reflective and multiphoton imaging can be used to reveal complementary structural information of the corneal architecture.. The system is first tested on porcine eye cornea. Assessment of the result on the porcine eye will be used to evaluate the potential of the system as a technique for in vivo clinical applications.

Chen, Wei-Liang; Lo, Wen; Sun, Yen; Lin, Sung-Jan; Tan, Hsin-Yuan; Dong, Chen-Yuan

2006-03-01

16

Combined FLIM and reflectance confocal microscopy for epithelial imaging  

NASA Astrophysics Data System (ADS)

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

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

2012-02-01

17

Food surface texture measurement using reflective confocal laser scanning microscopy.  

PubMed

Confocal laser scanning microscopy (CLSM) was used in the reflection mode to characterize the surface texture (roughness) of sliced food surfaces. Sandpapers with grit size between 150 and 600 were used as height references to standardize the CLSM hardware settings. Sandpaper particle sizes were verified by scanning electron microscopy (SEM). The mean amplitude (in micrometers) of surface variation along line segments of the scanned sandpaper topographical image sets showed very close agreement between the measured result and the grit particle size (based on the U.S. Coated Abrasive Manufactures Inst. {CAMI], standard). The verified instrument settings were then used to measure the surface texture of mechanically sliced food surfaces, including cooked ham, salami, and cheese. Sliced food surface texture parameters of Ra (average height of a line segment), Rs (surface area ratio), Pa (average height on a region of interest), and Pq (root-mean-square height on a region of interest) were evaluated by this method. Values of the surface roughness of sliced ham, salami, and cheese were found to be comparable to the range of dimensions of selected sandpapers. The CLSM method may be useful for other surface texture measurements, and to investigate the impact of food surface texture on microbial adhesion or attachment, which might play a significant role in microbial transfer from one surface to another. PMID:18576995

Sheen, S; Bao, G; Cooke, P

2008-06-01

18

Confocal fluorescence techniques in industrial application  

NASA Astrophysics Data System (ADS)

The FCS+plus family of evaluation tools for confocal fluorescence spectroscopy, which was developed during recent years, offers a comprehensive view to a series of fluorescence properties. Originating in fluorescence correlation spectroscopy (FCS) and using similar experimental equipment, a system of signal processing methods such as fluorescence intensity distribution analysis (FIDA) was created to analyze in detail the fluctuation behavior of fluorescent particles within a small area of detection. Giving simultaneous access to molecular parameters like concentration, translational and rotational diffusion, molecular brightness, and multicolor coincidence, this portfolio was enhanced by more traditional techniques of fluorescence lifetime as well as time-resolved anisotropy determination. The cornerstones of the FCS+plus methodology will be shortly described. The inhibition of a phosphatase enzyme activity gives a comprehensive industrial application that demonstrates FCS+plus' versatility and its potential for pharmaceutical drug discovery.

Eggeling, Christian; Gall, Karsten; Palo, Kaupo; Kask, Peet; Brand, Leif

2003-06-01

19

Fiber-optic confocal reflectance microscope with miniature objective for in vivo imaging of human tissues  

Microsoft Academic Search

We have built a fiber-optic confocal reflectance microscope capable of imaging human tissues in near real time. Miniaturization of the objective lens and the mechanical components for positioning and axially scanning the objective enables the device to be used in inner organs of the human body. The lateral resolution is 2 micrometers and axial resolution is 10 micrometers. Confocal images

Kung-Bin Sung; Chen Liang; Michael Descour; Tom Collier; Michele Follen; Rebecca Richards-Kortum

2002-01-01

20

Fiber-Optic Confocal Reflectance Microscope With Miniature Objective for In Vivo Imaging of Human Tissues  

Microsoft Academic Search

We have built a fiber-optic confocal reflectance microscope capable of imaging human tissues in near real time. Miniaturization of the objective lens and the mechanical compo- nents for positioning and axially scanning the objective enables the device to be used in inner organs of the human body. The lateral resolution is 2 micrometers and axial resolution is 10 micrometers. Confocal

Kung-Bin Sung; Chen Liang; Michael Descour; Tom Collier; Michele Follen; Rebecca Richards-Kortum

2002-01-01

21

In vivo reflectance confocal microscopy in a typical case of melasma.  

PubMed

Melasma is a common disorder of hypermelanosis that affects mainly young and middle-aged women of Fitzpatrick's phototypes III-V. The disease significantly impacts their lives. In vivo reflectance confocal microscopy, a spreading technology for the noninvasive evaluation of the skin up to the papillary dermis, provides real-time en face images with cellular resolution. We present a case of melasma with in vivo reflectance confocal microscopy findings closely correlated to the histopathological features described in the literature. PMID:23044577

Costa, Mariana Carvalho; Eljaiek, Hernando Vega; Abraham, Leonardo Spagnol; Azulay-Abulafia, Luna; Ardigo, Marco

22

In Vivo Imaging of Oral Neoplasia Using a Miniaturized Fiber Optic Confocal Reflectance Microscope  

PubMed Central

The purpose of this study was to determine whether in vivo images of oral mucosa obtained with a fiber optic confocal reflectance microscope could be used to differentiate normal and neoplastic tissues. We imaged 20 oral sites in 8 patients undergoing surgery for squamous cell carcinoma. Normal and abnormal areas within the oral cavity were identified clinically, and real-time videos of each site were obtained in vivo using a fiber optic confocal reflectance microscope. Following imaging, each site was biopsied and submitted for histopathologic examination. We identified distinct features, such as nuclear irregularity and spacing, which can be used to qualitatively differentiate between normal and abnormal tissue. Representative confocal images of normal, pre-neoplastic, and neoplastic oral tissue are presented. Previous work using much larger microscopes has demonstrated the ability of confocal reflectance microscopy to image cellular and tissue architecture in situ. New advances in technology have enabled miniaturization of imaging systems for in vivo use.

Maitland, Kristen C.; Gillenwater, Ann M.; Williams, Michelle D.; El-Naggar, Adel K.; Descour, Michael R.; Richards-Kortum, Rebecca R.

2008-01-01

23

Confocal and Two-Photon Microscopy: Foundations, Applications and Advances  

NASA Astrophysics Data System (ADS)

Confocal and Two-Photon Microscopy Foundations, Applications, and Advances Edited by Alberto Diaspro Confocal and two-photon fluorescence microscopy has provided researchers with unique possibilities of three-dimensional imaging of biological cells and tissues and of other structures such as semiconductor integrated circuits. Confocal and Two-Photon Microscopy: Foundations, Applications, and Advances provides clear, comprehensive coverage of basic foundations, modern applications, and groundbreaking new research developments made in this important area of microscopy. Opening with a foreword by G. J. Brakenhoff, this reference gathers the work of an international group of renowned experts in chapters that are logically divided into balanced sections covering theory, techniques, applications, and advances, featuring: In-depth discussion of applications for biology, medicine, physics, engineering, and chemistry, including industrial applications Guidance on new and emerging imaging technology, developmental trends, and fluorescent molecules Uniform organization and review-style presentation of chapters, with an introduction, historical overview, methodology, practical tips, applications, future directions, chapter summary, and bibliographical references Companion FTP site with full-color photographs The significant experience of pioneers, leaders, and emerging scientists in the field of confocal and two-photon excitation microscopy Confocal and Two-Photon Microscopy: Foundations, Applications, and Advances is invaluable to researchers in the biological sciences, tissue and cellular engineering, biophysics, bioengineering, physics of matter, and medicine, who use these techniques or are involved in developing new commercial instruments.

Diaspro, Alberto

2001-11-01

24

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

PubMed Central

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

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

2012-01-01

25

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

PubMed

Reflectance confocal microscopy (RCM) represents a noninvasive imaging technique that has previously been used for characterization of mycosis fungoides (MF) in a pilot study. We aimed to test the applicability of RCM for diagnosis and differential diagnosis of MF in a clinical study. A total of 39 test sites of 15 patients with a biopsy-proven diagnosis of either MF, parapsoriasis, Se?zary syndrome, or lymphomatoid papulosis were analyzed for presence and absence of RCM features of MF. Cochran and Chi(2) analysis were applied to test the concordance between investigators and the distribution of RCM features, respectively. For selected parameters, the Cochran analysis showed good concordance between investigators. Inter-observer reproducibility was highest for junctional atypical lymphocytes, architectural disarray, and spongiosis. Similarly, Chi(2) analysis demonstrated that selected features were present at particularly high frequency in individual skin diseases, with values ranging from 73% to 100% of all examined cases. PMID:22352651

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

2012-01-01

26

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

NASA Astrophysics Data System (ADS)

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

Yang, Li-Song; Wang, Guiying; Wang, Jiangang; Xu, Zhizhan

1999-09-01

27

Cellular features of psoriatic skin: imaging and quantification using in vivo reflectance confocal microscopy  

Microsoft Academic Search

BACKGROUND: In vivo reflectance confocal microscopy (RCM) is a novel, exciting imaging technique. It provides images of cell-and tissue structures and dynamics in situ, in real time, without the need for ex vivo tissue samples. RCM visualizes the superficial part of human skin up to a depth of 250 mum. In psoriasis, an erythematosquamous skin disease, we evaluated well known

E. A. W. Wolberink; P. E. J. van Erp; M. M. Teussink; M. J. P. Gerritsen

2011-01-01

28

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.

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

2011-01-01

29

High numerical aperture injection-molded miniature objective for fiber-optic confocal reflectance microscopy  

NASA Astrophysics Data System (ADS)

This dissertation presents the design of a miniature injection-molded objective lens for a fiber-optic confocal reflectance microscope. This is part of an effort to demonstrate the ability to fabricate low cost, high performance biomedical optics for high resolution in vivo imaging. Disposable endoscopic microscope objectives could help in vivo confocal microscopy technology mature to enable large-scale clinical screening and detection of early cancers and pre-cancerous lesions. This five lens plastic objective has been tested as a stand-alone optical system and has been coupled to a confocal microscope for in vivo imaging of cells and tissue. Changing the spacing and rotation of the individual optical elements can compensate for fabrication inaccuracies and improve performance. An optical-bench testing system was constructed to allow interactive alignment during testing. The modulation transfer function (MTF) of the miniature objective lens is determined using the slanted-edge method. A custom MATLAB program, edgeMTF, was written to collect, analyze, and record test data. An estimated Strehl ratio of 0.64 and an MTF value of 0.70, at the fiber-optic bundle Nyquist frequency, have been obtained. The main performance limitations of the miniature objective are mechanical alignment and flow-induced birefringence. Annealing and experimental injection molding runs were conducted in effort to reduce birefringence.

Chidley, Matthew Douglas

30

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

NASA Astrophysics Data System (ADS)

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

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

2010-08-01

31

Real-TimeReflectance Confocal Microscopy, a Noninvasive Tool for in vivo Quantitative Evaluation of Comedolysis in the Rhino Mouse Model  

Microsoft Academic Search

Background: Near-infrared reflectance confocal microscopy (RCM) is a noninvasive tool that provides real-time images of thin virtual horizontal tissue sections. Aims\\/Methods: We have used a rhino mouse model in combination with topical application of all-trans-retinoic acid and all-trans-retinol to investigate the usefulness of RCM as a noninvasive imaging tool to evaluate comedolysis in vivo and over time. Optical images were

K. Nakano; K. Kiyokane; C. Benvenuto-Andrade; S. González

2007-01-01

32

Computational characterization of reflectance confocal microscopy features reveals potential for automated photoageing assessment.  

PubMed

Skin photoageing results from a combination of factors including ultraviolet (sun) exposure, leading to significant changes in skin morphology and composition. Conventional methods assessing the degree of photoageing, in particular histopathological assessment involve an invasive multistep process. Advances in microscopy have enabled a shift towards non-invasive in vivo microscopy techniques such as reflectance confocal microscopy (RCM) in this context. Computational image analysis of RCM images has the potential to be of use in the non-invasive assessment of photoageing. In this report, we computationally characterized a clinical RCM data set from younger and older Caucasians with varying levels of photoageing. We identified several mathematical relationships that related to the degree of photoageing as assessed by conventional scoring approaches (clinical photography, SCINEXA and RCM). Furthermore, by combining the mathematical features into a single computational assessment score, we observed significant correlations with conventional RCM (P < 0.0001) and the other clinical assessment techniques. PMID:23800056

Raphael, Anthony P; Kelf, Timothy A; Wurm, Elizabeth M T; Zvyagin, Andrei V; Soyer, Hans Peter; Prow, Tarl W

2013-07-01

33

Confocal scanning beam laser microscope\\/macroscope: applications in fluorescence  

Microsoft Academic Search

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

Arthur E. Dixon; Savvas Damaskinos; Alfonso Ribes

1996-01-01

34

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

PubMed Central

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

Larson, Bjorg; Abeytunge, Sanjeewa; Rajadhyaksha, Milind

2011-01-01

35

Determine scattering coefficient and anisotropy of scattering of murine tissues using reflectance-mode confocal microscopy  

NASA Astrophysics Data System (ADS)

Different techniques have been developed to determine the optical properties of turbid media, which include collimated transmission, diffuse reflectance, adding-doubling and goniometry. While goniometry can be used to determine the anisotropy of scattering (g), other techniques are used to measure the absorption coefficient and reduced scattering coefficient (?s(1-g)). But separating scattering coefficient (?s) and anisotropy of scattering from reduced scattering coefficient has been tricky. We developed an algorithm to determine anisotropy of scattering from the depth dependent decay of reflectance-mode confocal scanning laser microscopy (rCSLM) data. This report presents the testing of the algorithm on tissue phantoms with different anisotropies (g = 0.127 to 0.868, at 488 nm wavelength). Tissue phantoms were made from polystyrene microspheres (6 sizes 0.1-0.5 ?m dia.) dispersed in both aqueous solutions and agarose gels. Three dimensional images were captured. The rCSLM-signal followed an exponential decay as a function of depth of the focal volume, R(z)?exp(-?z) where ? (dimensionless, ? = 1 for a mirror) is the local reflectivity and ? [cm-1] is the exponential decay constant. The theory was developed to uniquely map the experimentally determined ? and ? into the optical scattering properties ?s and g. The values of ?s and g depend on the composition and microstructure of tissues, and allow characterization of a tissue.

Samatham, Ravikant; Jacques, Steven L.

2013-02-01

36

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

37

Combined reflectance confocal microscopy/optical coherence tomography imaging for skin burn assessment  

PubMed Central

A combined high-resolution reflectance confocal microscopy (RCM)/optical coherence tomography (OCT) instrument for assessing skin burn gravity has been built and tested. This instruments allows for visualizing skin intracellular details with submicron resolution in the RCM mode and morphological and birefringence modifications to depths on the order of 1.2 mm in the OCT mode. Preliminary testing of the dual modality imaging approach has been performed on the skin of volunteers with some burn scars and on normal and thermally-injured Epiderm FTTM skin constructs. The initial results show that these two optical technologies have complementary capabilities that can offer the clinician a set of clinically comprehensive parameters: OCT helps to visualize deeper burn injuries and possibly quantify collagen destruction by measuring skin birefringence, while RCM provides submicron details of the integrity of the epidermal layer and identifies the presence of the superficial blood flow in the upper dermis. Therefore, the combination of these two technologies within the same instrument may provide a more comprehensive set of parameters that may help clinicians to more objectively and nonivasively assess burn injury gravity by determining tissue structural integrity and viability.

Iftimia, Nicusor; Ferguson, R. Daniel; Mujat, Mircea; Patel, Ankit H.; Zhang, Ellen Ziyi; Fox, William; Rajadhyaksha, Milind

2013-01-01

38

In Vivo Reflectance Confocal Microscopy of Basal Cell Carcinoma: Feasibility of Preoperative Mapping of Cancer Margins  

PubMed Central

Reflectance confocal microscopy (RCM) images skin at cellular resolution and has shown utility for the diagnosis of nonmelanoma skin cancer in vivo. It has the potential to define lesion margins before surgical therapy. Objectives To investigate the feasibility of RCM in defining the margins of basal cell carcinoma before surgery. Methods The margins of 10 lesions were evaluated using RCM. Biopsies of the margins were used to confirm the results. A protocol was constructed to define margins. RCM was used to delineate preoperative surgical margins in 13 patients. Intraoperative frozen biopsy was used to confirm the margins. Results In seven of 10 (70.0%) cases, the margins of the cancer were identified suing RCM. The tumor island was the critical feature in identifying the margins. In 12 of 13 (92.3%) cases, frozen biopsy corroborated that the surgical margins delineated by RCM were clear. Conclusion RCM imaging of the margins is feasible and demonstrates the possibility of preoperative mapping of cancer margins.

Pan, Zhan-Yan; Lin, Jing-Ran; Cheng, Ting-Ting; Wu, Jia-Qiang; Wu, Wen-Yu

2012-01-01

39

Laser scanning confocal microscopy: history, applications, and related optical sectioning techniques.  

PubMed

Confocal microscopy is an established light microscopical technique for imaging fluorescently labeled specimens with significant three-dimensional structure. Applications of confocal microscopy in the biomedical sciences include the imaging of the spatial distribution of macromolecules in either fixed or living cells, the automated collection of 3D data, the imaging of multiple labeled specimens and the measurement of physiological events in living cells. The laser scanning confocal microscope continues to be chosen for most routine work although a number of instruments have been developed for more specific applications. Significant improvements have been made to all areas of the confocal approach, not only to the instruments themselves, but also to the protocols of specimen preparation, to the analysis, the display, the reproduction, sharing and management of confocal images using bioinformatics techniques. PMID:24052346

Paddock, Stephen W; Eliceiri, Kevin W

2014-01-01

40

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

PubMed

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

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

2012-11-29

41

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.

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

2010-01-01

42

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

NASA Astrophysics Data System (ADS)

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

Glazowski, Christopher; Abeytunge, Sanjeewa; Rajadhyaksha, Milind

2012-02-01

43

A confocal video-rate laser-beam scanning reflected-light microscope with no moving parts.  

PubMed

A no-moving-parts, 30 frames/s, laser-beam scanning confocal reflected-light microscope has been developed. In principle, the technique can be extended to fluorescence and transmission light microscopy. Acousto-optic beam deflectors controlled by digital electronics move a laser beam in a 512-line interlaced 8.5 x 8.5-mm raster. The light passes through a beam splitter, enters an inverted microscope through the side camera port, and is imaged at the object by the microscope objective. Reflected light returns through the objective, exits the camera port, is reflected off the beam splitter, and is imaged on to the photocathode of an image dissector tube (IDT). Confocality is provided by raster scanning the IDT aperture coincident with the congruent image of the laser beam incident on the object. Real-time jitter-free reflected light images of a variety of biological objects have been produced. Computer-controlled alignment of the laser scan and IDT is performed in several seconds. PMID:2299661

Goldstein, S R; Hubin, T; Rosenthal, S; Washburn, C

1990-01-01

44

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

NASA Astrophysics Data System (ADS)

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

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

2012-02-01

45

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

NASA Astrophysics Data System (ADS)

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

Rajadhyaksha, Milind M.; Gonzalez, Salvador

2003-06-01

46

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

NASA Astrophysics Data System (ADS)

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

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

2012-06-01

47

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

PubMed

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

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

2013-02-25

48

Effect of clearing agents on scattering coefficient and anisotropy of scattering of dermis studied by reflectance confocal microscopy  

NASA Astrophysics Data System (ADS)

Optical clearing of mouse dermis by glycerol was tested by reflectance-mode confocal microscopy (rCSLM) using 488- nm light. The reflectance signal R(z) was acquired as a function of the depth of the focus (z) within the upper 100 ?m of freshly excised mouse dermis. The results specify the scattering coefficient (?s [cm-1]) and the anisotropy of scattering (g [dimensionless]). The absorption is too low to exert an effect. The results, published in Samatham et al., Journal of Innovative Optical Health Sciences 2010, 3(3):183-188, described how the clearing effect of glycerol was to increase g toward nearly 1.0, while having only a modest effect on ?s. In other words, glycerol caused light scattering to become very forward-directed, but did not strongly alter the number of scattering events per unit length of photon path. This paper discusses the possible mechanism of action that is responsible for this clearing effect.

Jacques, S. L.; Samatham, R.; Phillips, K. G.

2011-02-01

49

Application of the laser scanning confocal microscope in fluorescent film sensor research  

NASA Astrophysics Data System (ADS)

Confocal microscopy offers several advantages over conventional optical microscopy; we show an experimental investigation laser scanning confocal microscope as a tool to be used in cubic boron nitride (cBN) film-based fluorescent sensor research. Cubic boron nitride cBN film sensors are modified with dansyl chloride and rhodamine B isothiocyanate respectively. Fluorescent modification quality on the cubic boron nitride film is clearly express and the sensor ability to Hg2+ cations and pH are investigated in detail. We evidence the rhodamine B isothiocyanate modified quality on cBN surface is much better than that of dansyl chloride. And laser scanning confocal microscope has potential application lighttight fundus film fluorescent sensor research.

Zhang, Hongyan; Liu, Wei-Min; Zhao, Wen-Wen; Dai, Qing; Wang, Peng-Fei

2010-05-01

50

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

NASA Astrophysics Data System (ADS)

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

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

1991-05-01

51

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

PubMed

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. PMID:23338938

Ulrich, Martina; Lange-Asschenfeldt, Susanne

2013-06-01

52

[In vivo reflectance-mode confocal laser microscopy: basic principles and clinical and research employments in dermatology].  

PubMed

Reflectance-mode confocal scanning laser microscopy is a novel, non-invasive imaging technique which permits real time visualization of cellular components in the skin at a resolution close to that of conventional histology. It has been widely used in the diagnosis of both benign and malignant tumors of the skin. In recent years it was also employed in the investigation of a variety of inflammatory and infectious skin conditions. The non-invasive nature of the procedure allows examination of multiple lesions and/ or repetitive sampling of one lesion over time, making it an excellent tool for followup and for monitoring treatment outcome in medical and cosmetic dermatology. This review summarizes the main indications for the use of this novel technique in clinical and experimental dermatology. PMID:23316665

Levi, Assi; Ingber, Arieh; Enk, David Claes

2012-10-01

53

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

PubMed

Scabies is an intensely pruritic disorder induced by a delayed type hypersensitivity reaction to infestation of the skin by the mite Sarcoptes scabiei. The diagnosis of scabies is established clinically and confirmed by identifying mites or eggs by microscopic examination of scrapings from the skin or by surface microscopy using a dermatoscope. Reflectance-mode confocal microscopy is a novel technique used for noninvasive imaging of skin structures and lesions at a resolution compatible to that of conventional histology. Recently, the technique was employed for the confirmation of the clinical diagnosis of scabies.We demonstrate the first ever documentation of a larva moving freely inside the skin of a patient infected with scabies. PMID:22734726

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

2012-06-01

54

[The place of confocal microscopy in gynecology].  

PubMed

The confocal microscopy is an optical imaging technique that allows true optical biopsies and a three-dimensional visualization of tissue sections and cells. The analysis of the signal is done thanks to reflected light (reflectance confocal microscopy) or to the fluorescence emitted by tissues (fluorescence confocal microscopy). The use of confocal microscopy in the gynecological field is still experimental and is mainly about the ex vivo and in vivo diagnosis of cervical dysplasia and ovary cancer. The miniaturization of the probes could allow an endoscopic use for the diagnosis of endometrial or ovary cancers. We aim to present the principles of confocal microscopy and to expose the main ways of research and the future and potential clinical applications of this technique in gynecology. PMID:17997232

Ascencio, M; Collinet, P; Cosson, M; Mordon, S

2007-11-07

55

3D imaging of porous media using laser scanning confocal microscopy with application to microscale transport processes  

Microsoft Academic Search

We present advances in the application of laser scanning confocal microscopy (LSCM) to image, reconstruct, and characterize statistically the microgeometry of porous geologic and engineering materials. We discuss technical and practical aspects of this imaging technique, including both its advantages and limitations. Confocal imaging can be used to optically section a material, with sub-micron resolution possible in the lateral and

J. T. Fredrich

1999-01-01

56

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

PubMed

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

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

57

Reflective coatings for solar applications  

SciTech Connect

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

Jorgensen, G.

1993-05-01

58

Reflective coatings for solar applications  

SciTech Connect

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

Jorgensen, G.

1993-05-01

59

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

PubMed

The standard diagnostic procedure for basal cell carcinoma (BCC) is invasive tissue biopsy with time-consuming histological examination. To reduce the number of biopsies, noninvasive optical methods have been developed providing high-resolution skin examination. We present direct comparison of a reflectance confocal microscope (RLSM) and a multiphoton tomograph (MPT) for BCC diagnosis. Both systems are applied to nine patients prior to surgery, and the results are analyzed, including histological results. Both systems prove suitable for detecting typical characteristics of BCC in various stages. The RLSM allows large horizontal overview images to be obtained, enabling the investigator to find the regions of interest quickly, e.g., BCC nests. Elongated cells and palisading structures are easily recognized using both methods. Due to the higher resolution, changes in nucleus diameter or cytoplasm could be visualized with the MPT. Therefore, the nucleus diameter, nucleus/cytoplasm ratio, and cell density are estimated for normal and BCC cells using the MPT. The nucleus of elongated BCC cells is significantly longer than other measured normal skin cells, whereas the cell density and nucleus/cytoplasm ratio of BCC cannot be significantly distinguished from granular cells. PMID:23456144

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

2013-06-01

60

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

NASA Astrophysics Data System (ADS)

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

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

2013-06-01

61

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

PubMed

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

Contaldo, Maria; Serpico, Rosario; Lucchese, Alberta

2013-04-13

62

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

Microsoft Academic Search

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

Ya-Li Yang; Laura J. Kaufman

2009-01-01

63

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

NASA Astrophysics Data System (ADS)

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

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

2008-06-01

64

The application of real-time confocal microscopy to the study of high-speed dental-bur-tooth-cutting interactions.  

PubMed

A tandem scanning reflected light microscope (TSM) has been used to study the cutting interactions of dental burs with enamel. Confocal microscopy produces high-resolution images of subsurface structures in semi-transparent specimens such as teeth. The TSM has a real-time imaging ability which allows the visualization of the high-speed failure of a substrate which is being machined. This paper describes the criteria for successful imaging and their implementation in the design of a stage for controlling these cutting interactions. Examples of the results achieved are given and further applications for this technique in the field of biomaterials suggested. PMID:2299662

Watson, T F

1990-01-01

65

Reflectance confocal microscopy for characterization of mammary ductal structures and development of neoplasia in genetically engineered mouse models of breast cancer.  

PubMed

The earliest steps of breast cancer begin with aberrations in mammary ductal structure. Techniques that enable an investigator to image in situ and then analyze the same tissue using biochemical tools facilitates identification of genetic networks and signaling pathways active in the imaged structure. Cellular confocal microscopy (VivaCell-TiBa, Rochester, New York) is used to image mammary ductal structures and surrounding vasculature in situ in intact wild-type and genetically engineered mice that develop ER alpha-initiated ductal carcinoma in situ (DCIS) and ER alpha-driven invasive mammary cancer. In wild-type mice, normal mammary ductal structures that appear from puberty through lactation are visualized and serially sectioned optically, and a developmental atlas is created. Altering tissue preparation enabled visualization of the vasculature surrounding the ductal structures. In the genetically engineered mice, aberrant mammary ductal structures and cancers are imaged and compared to corresponding normal structures. Different preparation techniques are able to preserve tissue for routine histological analyses and RNA isolation. Comparative studies demonstrate that reflectance confocal imaging provides more cellular detail than carmine-alum-stained mammary gland whole mounts and equivalent detail with hematoxylin and eosin stained tissue sections. In summary, reflectance confocal microscopy is a tool that can be used to rapidly and accurately analyze mammary gland structure. PMID:16292950

Parrish, Angela; Halama, Ewa; Tilli, Maddalena T; Freedman, Matthew; Furth, Priscilla A

66

Confocal scanning beam laser microscope\\/macroscope: applications requiring large data sets  

Microsoft Academic Search

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

Arthur E. Dixon; Savvas Damaskinos; Alfonso Ribes; Eileen Seto; Marie-Claude Beland; Tetsu Uesaka; Brian Dalrymple; Sid P. Duttagupta; Philippe M. Fauchet

1995-01-01

67

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.

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

2001-01-01

68

Design, assembly, and optical bench testing of a high-numerical-aperture miniature injection-molded objective for fiber-optic confocal reflectance microscopy  

NASA Astrophysics Data System (ADS)

The design, analysis, assembly methods, and optical-bench test results for a miniature injection-molded plastic objective lens used in a fiber-optic confocal reflectance microscope are presented. The five-lens plastic objective was tested as a stand-alone optical system before its integration into a confocal microscope for in vivo imaging of cells and tissue. Changing the spacing and rotation of the individual optical elements can compensate for fabrication inaccuracies and improve performance. The system performance of the miniature objective lens is measured by use of an industry-accepted slanted-edge modulation transfer function (MTF) metric. An estimated Strehl ratio of 0.61 and a MTF value of 0.66 at the fiber-optic bundle Nyquist frequency have been obtained. The optical bench testing system is configured to permit interactive optical alignment during testing to optimize performance. These results are part of an effort to demonstrate the manufacturability of low-cost, high-performance biomedical optics for high-resolution in vivo imaging. Disposable endoscopic microscope objectives could help in vivo confocal microscopy technology mature to permit wide-scale clinical screening and detection of early cancers and precancerous lesions.

Chidley, Matthew D.; Carlson, Kristen D.; Richards-Kortum, Rebecca R.; Descour, Michael R.

2006-04-01

69

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

70

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

SciTech Connect

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

Fredrich, J.T.

1999-02-10

71

Confocal scanning Mueller polarimeter  

NASA Astrophysics Data System (ADS)

We describe the design, construction, calibration and testing of a confocal scanning Mueller polarimeter. A polarization state generator and polarization state analyzer have been inserted into the optical path of a conventional confocal scanning imager to collect the reflectance Muller matrix of samples measuring up to 6.26 mm on a side. Four sources are available for sample interrogation using diode lasers centered at 532 nm, 635 nm, 670 nm, and 785 nm. The device captures all required imagery to calculate the Mueller matrix of each image pixel in approximately 90 s. These matrices are then reduced into polarization imagery such as the diattenuation, retardance and depolarization index. Oftentimes this polarization imagery is quite different and potentially more informative than a conventional intensity image. There are a number of fields that can benefit from alternative/enhanced imagery, most notably in the biomedical, discrimination, and target recognition communities. The sensor has been designed for biomedical applications aimed at improving the technique of noninvasive detection of melanoma lesions.

Lompado, Arthur

2009-08-01

72

Application of confocal laser scanning microscopy in characterization of chemical enhancers in drug-in-adhesive transdermal patches  

Microsoft Academic Search

The purpose of this study was to evaluate the application of confocal laser scanning microscopy (CLSM) in the examination\\u000a of the embedment and the release characteristics of chemical permeation enhancers from transdermal drug delivery systems (TDDSs)\\u000a of the “drug-in-adhesive” type. The enhancer lauric acid and a lauric acid fluorescing probe of the Bodipy type were incorporated\\u000a into TDDSs consisting of

Michael H. Qvist; Ulla Hoeck; Bo Kreilgaard; Flemming Madsen; Lars Hovgaard; Sven Frokjaer

2002-01-01

73

Fluorescein conjugates of 9- and 10-hydroxystearic acids: synthetic strategies, photophysical characterization, and confocal microscopy applications.  

PubMed

Different strategies are presented to conjugate a fluorescein moiety to 9- and 10-hydroxystearic acids (HSAs). 5-Amino-fluorescein (5-AF) was used as a starting reagent. When reacted with acyl-chloride-modified HSAs, 5-AF gave rise to stable amide derivatives with a 75% reaction yield. These products exhibited the typical steady-state and time-resolved fluorescence properties of the fluorescein chromophore with absorption at 494 nm and emission at 519 nm. Flow cytometry studies confirmed the distinct proapoptotic effect of underivatized 9-HSA on Jurkat cells and revealed a comparable ability of its amide derivative. Confocal microscopy imaging studies showed that green fluorescence could stain intracellular membranous structures. Moreover, dual-dye labeling with Mito Tracker Red, followed by colocalization analysis, revealed that HSA can move to the mitochondria. Thus, fluorescent derivatives of HSA can be used to monitor the localization of these biologically active molecules in living cells and can provide a useful tool for linking biochemical investigation with optical visualization methods. In contrast, when unmodified HSAs were used, the reaction gave monoesterified and diesterified fluorescein derivatives. These products exhibited unusual steady-state and time-resolved fluorescence properties with the excitation wavelength at 342 nm and the emission wavelength at 432 nm. It is shown that the synthesized HSA amides of fluorescein provide all of the typical photophysical and instrumental advantages of this popular dye, whereas the unusual luminescence and excitation properties of the monoester and diester of the 5-aminofluorescein would make these dyes interesting to explore as potential candidates for two photon excitation applications. PMID:15556558

Boga, Carla; Puggioli, Silvia; Gherpelli, Marica; Farruggia, Giovanna; Pagnotta, Eleonora; Masotti, Lanfranco; Neyroz, Paolo

2004-12-15

74

3D Imaging of Porous Media Using Laser Scanning Confocal Microscopy with Application to Microscale Transport Processes; Physics and Chemistry of the Earth.  

National Technical Information Service (NTIS)

The authors present advances in the application of laser scanning confocal microscopy (LSCM) to image, reconstruct, and characterize statistically the microgeometry of porous geologic and engineering materials. The authors discuss technical and practical ...

J. T. Fredrich

1999-01-01

75

Application of Confocal Laser Scanning Microscopy (CLSM) for Observing Adhesives in Paper  

Microsoft Academic Search

Many kinds of adhesives are used to produce paper and prints. However, it is difficult to observe the distribution of these adhesives in situ because most are transparent and of low content. We have developed a fluorescence staining technique, which observes adhesives in paper with a confocal laser scanning microscope (CLSM) after staining with specific fluorescent dyes. In this review,

Yasushi Ozaki

2011-01-01

76

Non-beating HL1 cells for confocal microscopy: Application to mitochondrial functions during cardiac preconditioning  

Microsoft Academic Search

HL-1, the first cell line with a cardiac phenotype for biological experiments, displays spontaneous electrophysiological and mechanical regular activity, and cyclic calcium movements. We isolated a derived line, devoid of transient movements, for confocal microscopy experiments. These cells do express cardiac proteins: connexin 43, the cardiac isoform of dihydropyridine receptors, desmin, and developmental myosin but have no sarcomeric arrangement. They

Sophie Pelloux; Julie Robillard; René Ferrera; André Bilbaut; Carlos Ojeda; Valdur Saks; Michel Ovize; Yves Tourneur

2006-01-01

77

Numerical Application of Concepts from Confocal Microscopy to Holography and Other Coherent Imaging Systems  

Microsoft Academic Search

A novel methodology based on the scanning confocal microscope is presented which enables a general solution of the depth resolution problem in holography and other coherent imaging schemes. The method does not depend on a priori information about the object. Background and historical perspective are provided, as well as some review of the Rayleigh-Sommerfeld diffraction formulation and other pertinent physical

Marc Jeston Byrd

1994-01-01

78

Digital holographic confocal microscope  

NASA Astrophysics Data System (ADS)

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

Goy, Alexandre S.; Psaltis, Demetri

2013-02-01

79

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

PubMed Central

Although confocal microscopes have considerably smaller contribution of out-of-focus light than widefield microscopes, the confocal images can still be enhanced mathematically if the optical and data acquisition effects are accounted for. For that, several deconvolution algorithms have been proposed. As a practical solution, maximum-likelihood algorithms with regularization have been used. However, the choice of regularization parameters is often unknown although it has considerable effect on the result of deconvolution process. The aims of this work were: to find good estimates of deconvolution parameters; and to develop an open source software package that would allow testing different deconvolution algorithms and that would be easy to use in practice. Here, 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.

Laasmaa, M; Vendelin, M; Peterson, P

2011-01-01

80

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

PubMed Central

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

Garcia-Hernandez, Alejandra; Roldan-Marin, Rodrigo; Iglesias-Garcia, Pablo; Malvehy, Josep

2013-01-01

81

Digital confocal microscope.  

PubMed

We demonstrate experimentally a scanning confocal microscopy technique based on digital holography. The method relies on digital holographic recording of the scanned spot. The data collected in this way contains all the necessary information to digitally produce three-dimensional images. Several methods to treat the data are presented. Examples of reflection and transmission images of epithelial cells and mouse brain tissue are shown. PMID:23037422

Goy, Alexandre S; Psaltis, Demetri

2012-09-24

82

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

PubMed

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

2013-08-28

83

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.

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

2013-01-01

84

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

PubMed Central

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

Yang, Ya-li; Kaufman, Laura J.

2009-01-01

85

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

NASA Astrophysics Data System (ADS)

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

Kuypers, Liesbeth

86

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

Microsoft Academic Search

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

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

1992-01-01

87

Unanticipated partial behavioral reflection: Adapting applications at runtime  

Microsoft Academic Search

Dynamic, unanticipated adaptation of running systems is of interest in a variety of situations, ranging from functional upgrades to on-the-fly debugging or monitoring of critical applications. In this paper we study a particular form of computational reflection, calledunanticipated partial behavioral reflection(UPBR), which is particularly well suited for unanticipated adaptation of real- world systems. Our proposal combines the dynamicity of unanticipated

David Röthlisberger; Marcus Denker; Éric Tanter

2008-01-01

88

Normally black reflective twisted-nematic cell for microdisplay application  

NASA Astrophysics Data System (ADS)

A normally black reflective twisted-nematic mode is proposed for microdisplay application. This mode is based on the polarization rotation effect of a twisted-nematic liquid crystal. In the dark state, the cell exhibits a large gap tolerance and weak color dispersion. For twist angle ranging from 45° to 65°, the maximum normalized reflectance can achieve 100% through d/p (cell gap over pitch) ratio optimization. Particularly, when the twist angle equals to 52°, the normalized reflectance can reach 100% without any chiral dopant. The twist angle and polarizer angle also make important contributions to the bright state optical efficiency and dark state spectral bandwidth.

Zhu, Xinyu; Wu, Shin-Tson

2004-06-01

89

Video-rate Scanning Confocal Microscopy and Microendoscopy  

PubMed Central

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

Nichols, Alexander J.; Evans, Conor L.

2011-01-01

90

Identifying brain neoplasms using dye-enhanced multimodal confocal imaging  

NASA Astrophysics Data System (ADS)

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.

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

2012-02-01

91

A new wide field-of-view confocal imaging system and its applications in drug discovery and pathology  

Microsoft Academic Search

Conventional widefield light microscopy and confocal scanning microscopy have been indispensable for pathology and drug discovery research. Clinical specimens from diseased tissues are examined, new drug candidates are tested on drug targets, and the morphological and molecular biological changes of cells and tissues are observed. High throughput screening of drug candidates requires highly efficient screening instruments. A standard biomedical slide

Gang Li; Savvas Damaskinos; Arthur E. Dixon; Lucy E. J. Lee

2005-01-01

92

A new wide field-of-view confocal imaging system and its applications in drug discovery and pathology  

Microsoft Academic Search

Conventional widefield light microscopy and confocal scanning microscopy have been indispensable for pathology and drug discovery research. Clinical specimens from diseased tissues are examined, new drug candidates are tested on drug targets, and the morphological and molecular biological changes of cells and tissues are observed. High throughput screening of drug candidates requires highly efficient screening instruments. A standard bio- medical

Gang Li; Savvas Damaskinos; Arthur E. Dixon; Lucy E. J. Lee

93

Compressive confocal microscopy  

Microsoft Academic Search

In this paper, a new framework for confocal microscopy based on the novel theory of compressive sensing is pro- posed. Unlike wide field microscopy or conventional parallel beam confocal imaging systems that use charge-coupled de- vices (CCD) as acquisition devices in addition to complex mechanical scanning system, the proposed compressive con- focal microscopy is a kind of parallel beam confocal

Peng Ye; José L. Paredes; Gonzalo R. Arce; Yuehao Wu; Caihua Chen; Dennis W. Prather

2009-01-01

94

Chromatic confocal spectral interferometry  

Microsoft Academic Search

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

Evangelos Papastathopoulos; Klaus Koerner; Wolfgang Osten

2006-01-01

95

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

96

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

97

An Enhanced Reflection Removal Technique and its Applications  

NASA Astrophysics Data System (ADS)

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

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

98

Clinical applications of lightguide diffuse reflectance spectrophotometry in vascular disease  

Microsoft Academic Search

There is enormous potential for application of lightguide tissue reflectance spectrophotometry in the diagnosis and treatment of peripheral vascular disease. In the present study, measurements were carried out in 10 such pre-amputation patients to compare the use of micro-lightguide spectrophotometry with the macro-lightguide technique. These preliminary results show excellent agreement between the new, non-invasive micro-lightguide technique and the `gold standard'

David K. Harrison; Colin Delaney; Linda Brown; David Newton; Peter T. McCollum

1994-01-01

99

Contrast reversal confocal microscopy  

NASA Astrophysics Data System (ADS)

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

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

2013-07-01

100

The application of in vivo laser confocal microscopy to the diagnosis and evaluation of meibomian gland dysfunction  

PubMed Central

Purpose To evaluate the morphological changes of the meibomian glands (MG) in patients with meibomian gland dysfunction (MGD) compared to normal subjects by in vivo confocal microscopy and to investigate the relation of these changes to the clinical ocular surface findings and tear functions. Methods Twenty MGD patients and 15 normal subjects were recruited into this prospective study. Patients and controls underwent slit lamp examinations, tear film break-up time (BUT) measurements, fluorescein and Rose-Bengal stainings, Schirmer test I without anesthesia, tear evaporation rate assessment (TEROS), tear film lipid layer interferometry (DR-1), transillumination of the lids (meibography), MG expressibility test, and in vivo laser confocal microscopy of the lids (HRTII-RCM). Results The BUT, DR-1 tear film lipid layer interferometry grades, fluorescein and Rose-Bengal staining scores, MG drop out grade in meibography, and MG expressibility grades were significantly worse in MGD patients compared to normal controls (p<0.05). The severity of both MG dropout and MG expressibility related significantly with the BUT, DR-1 grades, and TEROS (p<0.05). The mean density of acinar units of MGs as measured by HRTII-RCM was significantly lower in MGD patients (47.6±26.6/mm2) than in control subjects (101.3±33.8/mm2; p<0.05). The mean acinar unit diameter as determined by HRTII-RCM was significantly larger in MGD patients (98.2±53.3 ?m) than in controls (41.6±11.9 ?m; p<0.05). Both the density and diameter of MG acinar units related significantly with the severity of MG dropout and MG expression grades (p<0.05). Conclusions In vivo confocal microscopy can effectively demonstrate the morphological changes of the MG in patients with MGD. Glandular acinar density and acinar unit diameter seemed to be promising new parameters of in vivo confocal microscopy, which is significantly related to the clinical ocular surface and tear function findings of MGD.

Matsumoto, Yukihiro; Sato, Enrique Adan; Ibrahim, Osama M.A.; Tsubota, Kazuo

2008-01-01

101

Confocal fluorescence microendoscopy of bronchial epithelium  

NASA Astrophysics Data System (ADS)

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

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

2009-03-01

102

Confocal simultaneous phase-shifting interferometry  

SciTech Connect

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

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

2011-02-10

103

Clinical applications of lightguide diffuse reflectance spectrophotometry in vascular disease  

NASA Astrophysics Data System (ADS)

There is enormous potential for application of lightguide tissue reflectance spectrophotometry in the diagnosis and treatment of peripheral vascular disease. In the present study, measurements were carried out in 10 such pre-amputation patients to compare the use of micro-lightguide spectrophotometry with the macro-lightguide technique. These preliminary results show excellent agreement between the new, non-invasive micro-lightguide technique and the `gold standard' skin blood flow measurements. This technique could thus provide a more functional, non-invasive assessment of healing potential than skin blood flow measurement.

Harrison, David K.; Delaney, Colin; Brown, Linda; Newton, David; McCollum, Peter T.

1994-02-01

104

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

105

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

106

Aorta Fluorescence Imaging by Using Confocal Microscopy  

PubMed Central

The activated leukocyte attacked the vascular endothelium and the associated increase in VEcadherin number was observed in experiments. The confocal microscopic system with a prism-based wavelength filter was used for multiwavelength fluorescence measurement. Multiwavelength fluorescence imaging based on the VEcadherin within the aorta segment of a rat was achieved. The confocal microscopic system capable of fluorescence detection of cardiovascular tissue is a useful tool for measuring the biological properties in clinical applications.

Wang, Chun-Yang; Tsai, Jui-che; Chuang, Ching-Cheng; Hsieh, Yao-Sheng; Sun, Chia-Wei

2011-01-01

107

Confocal Microscopy in Biopsy Proven Argyrosis  

PubMed Central

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

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

2013-01-01

108

Seismic interferometry, with applications in passive reflection imaging  

NASA Astrophysics Data System (ADS)

Seismic interferometry is the process of generating new seismic responses by crosscorrelating seismic observations at different receiver locations. A first version of this principle was derived in 1968 by Claerbout, who showed that the reflection response of a horizontally layered medium can be synthesized from the autocorrelation of its transmission response. Later he conjectured a similar principle for crosscorrelations of 3-D wave fields. In a similar fashion, Schuster (2001) introduced the principle of interferometric imaging, i.e., forming an image of the subsurface from crosscorrelated seismic traces. In this paper we first discuss the theory of seismic interferometry for arbitrary 3-D inhomogeneous media (deterministic or random). Starting with the Rayleigh-Betti reciprocity theorem and the principle of time-reversal, we derive a number of relations that form the basis for seismic interferometry (amongst others these relations prove Claerbouts conjecture). Despite the difference in assumptions, these relations show a close resemblance with those of Weaver and Lobkis (2001) for the retrieval of the Greens function from diffuse wave field correlations. Next we discuss a number of applications, like passive seismic reflection imaging, surface wave reconstruction, improving sparse data sets and interferometric imaging for different geometries.

Wapenaar, Kees; Draganov, Deyan

2005-04-01

109

DMD-enabled confocal microendoscopy  

NASA Astrophysics Data System (ADS)

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

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

2001-05-01

110

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

PubMed Central

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

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

2013-01-01

111

Frustrated Total Internal Reflection: A Simple Application and Demonstration.  

ERIC Educational Resources Information Center

|Describes the total internal reflection process that occurs when the internal angle of incidence is equal to or greater than the critical angle. Presents a demonstration of the effect of frustrated total internal reflection (FTIR). (YDS)|

Zanella, F. P.; Magalhaes, D. V.; Oliveira, M. M.; Bianchi, R. F.; Misoguti, L.; Mendonca, C. R.

2003-01-01

112

Using a Database Application to Support Reflective Practice  

ERIC Educational Resources Information Center

|Reflective practice, or reflection, is considered such a vital component of the learning process that strategies and supporting tools warrant continued research in the learning sciences. Reflection has been defined as "deliberating on experience" (Pennington, 1995, p. 47), "an activity or process in which experience is recalled, considered and…

Vallance, Michael

2008-01-01

113

Using a Database Application to Support Reflective Practice  

ERIC Educational Resources Information Center

Reflective practice, or reflection, is considered such a vital component of the learning process that strategies and supporting tools warrant continued research in the learning sciences. Reflection has been defined as "deliberating on experience" (Pennington, 1995, p. 47), "an activity or process in which experience is recalled, considered and…

Vallance, Michael

2008-01-01

114

Research on the scanning system of fiber optic confocal microscope  

Microsoft Academic Search

Using dual-galvanometer optical scanning head as the reflecting type optic-fiber confocal scanning microscope's planar scanning outfit can achieve the fast scanning to plane image, but there are distortion and vignetting. In the paper, the basic principle of reflecting type fiber-optical confocal scanning microscope is described briefly. The distortion caused by using the common eyepiece as scanning lens, the inherent distortion

Xinglong Wang; Zeying Chi; Wenjian Chen

2001-01-01

115

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

116

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

117

Differential reflectivity and differential phase shift: Applications in radar meteorology  

Microsoft Academic Search

The differential scattering properties of classes of hydrometeors at linear orthogonal polarizations provide potentially important differences which may be exploited for radar measurements of precipitation. The ratio of the reflectivity at horizontal (ZH) and vertical (Zv) polarizations may be combined with other radar measurements such as absolute reflectivity and differential phase shift to determine drop size distributions. Previous model calculations

T. A. Seliga; V. N. Bringi

1978-01-01

118

Automated Analysis of Spines from Confocal Laser Microscopy Images: Application to the Discrimination of Androgen and Estrogen Effects on Spinogenesis  

PubMed Central

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

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

2011-01-01

119

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

120

Optimal pupil design for confocal microscopy  

NASA Astrophysics Data System (ADS)

Confocal reflectance microscopy may enable screening and diagnosis of skin cancers noninvasively and in real-time, as an adjunct to biopsy and pathology. Current instruments are large, complex, and expensive. A simpler, confocal line-scanning microscope may accelerate the translation of confocal microscopy in clinical and surgical dermatology. A confocal reflectance microscope may use a beamsplitter, transmitting and detecting through the pupil, or a divided pupil, or theta configuration, with half used for transmission and half for detection. The divided pupil may offer better sectioning and contrast. We present a Fourier optics model and compare the on-axis irradiance of a confocal point-scanning microscope in both pupil configurations, optimizing the profile of a Gaussian beam in a circular or semicircular aperture. We repeat both calculations with a cylindrical lens which focuses the source to a line. The variable parameter is the fillfactor, h, the ratio of the 1/e2 diameter of the Gaussian beam to the diameter of the full aperture. The optimal values of h, for point scanning are 0.90 (full) and 0.66 for the half-aperture. For line-scanning, the fill-factors are 1.02 (full) and 0.52 (half). Additional parameters to consider are the optimal location of the point-source beam in the divided-pupil configuration, the optimal line width for the line-source, and the width of the aperture in the divided-pupil configuration. Additional figures of merit are field-of-view and sectioning. Use of optimal designs is critical in comparing the experimental performance of the different configurations.

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

2010-02-01

121

Silicon anti-resonant reflecting optical waveguides for sensor applications  

Microsoft Academic Search

We review the design and fabrication considerations of silicon integrated optical (IO) waveguides and present a variety of device structures, for detection of mechanical signals, along with structures for coupling light to integrated photodetectors. These devices are based on the antiresonant reflecting optical waveguide (ARROW). The ARROW utilizes dielectric materials that are fully compatible with the standard integrated circuit (IC)

K. Benaissa; A. Nathan

1998-01-01

122

Reflectance of metallic indium for solar energy applications  

Microsoft Academic Search

An investigation has been conducted in order to compile quantitative data on the reflective properties of metallic indium. The fabricated samples were of sufficiently high quality that differences from similar second-surface silvered mirrors were not apparent to the human eye. Three second-surface mirror samples were prepared by means of vacuum deposition techniques, yielding indium thicknesses of approximately 1000 A. Both

F. L. Bouquet; T. Hasegawa

1984-01-01

123

Application of the wavelet packet subspace to reflective hyperspectral imagery  

NASA Astrophysics Data System (ADS)

Wavelet Packets have been used to detect trace gases in long-wave infrared hyperspectral imagery. Spectral features for gases in the long-wave infrared can be characterized as lorentzian emission and absorption features. This is unlike spectral features for materials in visible, near infrared, and short-wave infrared, which are dependent on both the source illumination and the physical reflective properties of the surface material. In the reflective domain, features are represented by a much greater variety of shapes and distributions. These types of features are ideal for an adaptive target signature approach such as the Wavelet Packet Subspace (WPS). The WPS technique applies the wavelet packet transform and selects a best basis for pattern matching. The wavelet packet transform is an extension of the wavelet transform, which fully decomposes a signal into a library of wavelet packet bases. An orthogonal best basis is chosen which best represents features in the target signature at multiple resolutions. This best basis is then used for target detection. In this research, the Wavelet Packet Subspace technique is extended to reflective hyperspectral imagery. Using hyperspectral imagery data with known ground truth, a quantitative comparison is made between the WPS technique and other spectral matching methods. Spectral angle mapper, and clutter matched filter, and WPS are compared. Initial results demonstrate that performance of the WPS technique for reflective hyperspectral imagery is comparable to that of existing methods.

Salvador, Mark Z.

2009-05-01

124

Application of multispectral reflectance for early detection of tomato disease  

NASA Astrophysics Data System (ADS)

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

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

2006-10-01

125

Implementation of Reflective Array Matched Filters for Radar Applications  

Microsoft Academic Search

Utilizing weighted reflective dot arrays, two types of narrow band matched radar filters wzre realized on ST-quartz. (1) Bandpass filters operating at a center frequency of 30 MHz with fractional bandwidths of 0.25% and 0.5% were designed to match 10 and 5 vs non-dispersive, rectangular transmitted pulses. These devices achieved outstanding phase linearity having typical phase errors of 0.5O RMS.

J. L. Thoss; D. Penunuri; M. Thostenson

1981-01-01

126

Application of acoustic reflection tomography to sonar imaging.  

PubMed

Computer-aided tomography is a technique for providing a two-dimensional cross-sectional view of a three-dimensional object through the digital processing of many one-dimensional views (or projections) taken at different look directions. In acoustic reflection tomography, insonifying the object and then recording the backscattered signal provides the projection information for a given look direction (or aspect angle). Processing the projection information for all possible aspect angles enables an image to be reconstructed that represents the two-dimensional spatial distribution of the object's acoustic reflectivity function when projected on the imaging plane. The shape of an idealized object, which is an elliptical cylinder, is reconstructed by applying standard backprojection, Radon transform inversion (using both convolution and filtered backprojections), and direct Fourier inversion to simulated projection data. The relative merits of the various reconstruction algorithms are assessed and the resulting shape estimates compared. For bandpass sonar data, however, the wave number components of the acoustic reflectivity function that are outside the passband are absent. This leads to the consideration of image reconstruction for bandpass data. Tomographic image reconstruction is applied to real data collected with an ultra-wideband sonar transducer to form high-resolution acoustic images of various underwater objects when the sonar and object are widely separated. PMID:15957762

Ferguson, Brian G; Wyber, Ron J

2005-05-01

127

Spectrally encoded slit confocal microscopy  

Microsoft Academic Search

A simple and cost-effective method for real-time imaging in confocal microscopy is proposed. Spectrally encoded slit confocal microscopy (SESCoM) uses a spectral encoding technique together with a confocal slit aperture to achieve two-dimensional images. Simulation and experimental results of the SESCoM's axial and lateral performances are presented. The measured FWHM of the axial response is 1.15 mum when an objective

Jeongmin Kim; Dongkyun Kang; Daegab Gweon

2006-01-01

128

An Enhanced Reflection Removal Technique and its Applications  

Microsoft Academic Search

Electroacoustic transducers using piezoelectric materials are popular in various applications such as underwater acoustics, ultrasound, earthquakes and elastic wave propagations. Especially, they are widely used in non-destructive testing for ultrasonic or acoustic emission transducers. In general, they generate and receive waves through media to find meaningful targets or physical characteristics of materials. However, in most uses, the media are bounded

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

2008-01-01

129

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

130

Diffuse reflectance spectroscopy: towards clinical application in breast cancer.  

PubMed

Diffuse reflectance spectroscopy (DRS) is a promising new technique for breast cancer diagnosis. However, inter-patient variation due to breast tissue heterogeneity may interfere with the accuracy of this technique. To tackle this issue, we aim to determine the diagnostic accuracy of DRS in individual patients. With this approach, DRS measurements of normal breast tissue in every individual patient are directly compared with measurements of the suspected malignant tissue. Breast tissue from 47 female patients was analysed ex vivo by DRS. A total of 1,073 optical spectra were collected. These spectra were analyzed for each patient individually as well as for all patients collectively and results were compared to the pathology analyses. Collective patient data analysis for discrimination between normal and malignant breast tissue resulted in a sensitivity of 90 %, a specificity of 88 %, and an overall accuracy of 89 %. In the individual analyses all measurements per patient were categorized as either benign or malignant. The discriminative accuracy of these individual analyses was nearly 100 %. The diagnosis was classified as uncertain in only one patient. Based on the results presented in this study, we conclude that the analysis of optical characteristics of different tissue classes within the breast of a single patient is superior to an analysis using the results of a cohort data analysis. When integrated into a biopsy device, our results demonstrate that DRS may have the potential to improve the diagnostic workflow in breast cancer. PMID:23225143

Evers, Daniel J; Nachabe, Rami; Vranken Peeters, Marie-Jeanne; van der Hage, Jos A; Oldenburg, Hester S; Rutgers, Emiel J; Lucassen, Gerald W; Hendriks, Benno H W; Wesseling, Jelle; Ruers, Theo J M

2012-12-06

131

Confocal coded aperture imaging  

DOEpatents

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

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

2001-01-01

132

Reflectance pulse oximetry--principles and obstetric application in the Zurich system.  

PubMed

Transmission and reflectance are the two main modes of pulse oximetry. In obstetrics, due to the absence of a transilluminable fetal part for transmission oximetry, the only feasible option is the reflectance mode, in which sensor and detector are located on the same surface of the body part. However, none of the reflectance pulse oximeters developed for intrapartum use are fully satisfactory, as indicated by the fact that none have entered routine use. We have designed, developed, constructed and tested a reflectance pulse oximeter with the possibility to adjust the electronic circuits and signal processing in order to determine the effects of various parameters on signal amplitude and wave-form and to optimize the sensitivity and spatial arrangement of the optical elements. Following an explanation of the principles of reflectance pulse oximetry, we report our experience with the design, development, construction and field-testing of an in-house reflectance pulse oximetry system for obstetric application. PMID:10023837

König, V; Huch, R; Huch, A

1998-08-01

133

Research on the scanning system of fiber optic confocal microscope  

NASA Astrophysics Data System (ADS)

Using dual-galvanometer optical scanning head as the reflecting type optic-fiber confocal scanning microscope's planar scanning outfit can achieve the fast scanning to plane image, but there are distortion and vignetting. In the paper, the basic principle of reflecting type fiber-optical confocal scanning microscope is described briefly. The distortion caused by using the common eyepiece as scanning lens, the inherent distortion and vignetting for pre-eyepiece dual galvanometer scanning system have been analyzed in theory, and the according high-speed scanning electronic control system that has the function of distortion correction and image processing has been discussed.

Wang, Xinglong; Chi, Zeying; Chen, Wenjian

2001-10-01

134

Confocal Raman Microscopy in Pharmaceutical Development  

NASA Astrophysics Data System (ADS)

There is a wide range of applications of confocal Raman microscopy in pharmaceutical development. It is a powerful tool to probe the distribution of components within a formulation, to characterize homogeneity of pharmaceutical samples, to determine solid state of drug substances and excipients and to characterize contaminations and foreign particulates. The information obtained by confocal Raman microscopy is extremely useful, sometimes even crucial, for drug substance design, for the development of solid and liquid formulations, as a tool for process analytics and for patent infringements and counterfeit analysis. In this chapter, those aspects and applications will be presented, focusing on solid drug formulations. This chapter will also reveal the advantages and demonstrate the synergies of Raman mapping as compared to similar imaging methods such as SEM/EDX, NIR and MIR imaging.

Haefele, Thomas F.; Paulus, Kurt

135

High-speed multispectral confocal imaging  

NASA Astrophysics Data System (ADS)

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

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

2013-02-01

136

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

NASA Astrophysics Data System (ADS)

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

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

1997-10-01

137

A new laser heterodyne confocal probe for ultraprecision measurement of discontinuous contours  

Microsoft Academic Search

In order to further improve the lateral resolution required for ultraprecision measurement of discontinuous surface contours, a new laser heterodyne confocal probe (LHCP) has been proposed for use in making ultraprecision bipolar absolute measurements. The new probe follows the principle of reflection confocal microscopes (RCM), and uses the property of RCM light intensity curves being almost invariant with the offset

Weiqian Zhao; Jiubin Tan; Lirong Qiu; Limin Zou

2005-01-01

138

The application of specular neutron reflection to the study of surfaces and interfaces  

NASA Astrophysics Data System (ADS)

In recent years the specular reflection of neutrons has proved to be a valuable new technique for determining the structure of surfaces and interfaces, and a widespread application to a range of problems in surface chemistry, solid films and surface magnetism has emerged. The white beam time of flight (TOF) method for reflection measurements, exploited on a pulsed neutron source, has proved to be particularly important. Recent developments on the instrumentation and analysis methods at ISIS are presented and recent experimental results, covering a range of scientific applications are discussed.

Penfold, J.

1992-06-01

139

Corneal Confocal Microscopy  

PubMed Central

OBJECTIVE The accurate quantification of human diabetic neuropathy is important to define at-risk patients, anticipate deterioration, and assess new therapies. RESEARCH DESIGN AND METHODS A total of 101 diabetic patients and 17 age-matched control subjects underwent neurological evaluation, neurophysiology tests, quantitative sensory testing, and evaluation of corneal sensation and corneal nerve morphology using corneal confocal microscopy (CCM). RESULTS Corneal sensation decreased significantly (P = 0.0001) with increasing neuropathic severity and correlated with the neuropathy disability score (NDS) (r = 0.441, P < 0.0001). Corneal nerve fiber density (NFD) (P < 0.0001), nerve fiber length (NFL), (P < 0.0001), and nerve branch density (NBD) (P < 0.0001) decreased significantly with increasing neuropathic severity and correlated with NDS (NFD r = ?0.475, P < 0.0001; NBD r = ?0.511, P < 0.0001; and NFL r = ?0.581, P < 0.0001). NBD and NFL demonstrated a significant and progressive reduction with worsening heat pain thresholds (P = 0.01). Receiver operating characteristic curve analysis for the diagnosis of neuropathy (NDS >3) defined an NFD of <27.8/mm2 with a sensitivity of 0.82 (95% CI 0.68–0.92) and specificity of 0.52 (0.40–0.64) and for detecting patients at risk of foot ulceration (NDS >6) defined a NFD cutoff of <20.8/mm2 with a sensitivity of 0.71 (0.42–0.92) and specificity of 0.64 (0.54–0.74). CONCLUSIONS CCM is a noninvasive clinical technique that may be used to detect early nerve damage and stratify diabetic patients with increasing neuropathic severity.

Tavakoli, Mitra; Quattrini, Cristian; Abbott, Caroline; Kallinikos, Panagiotis; Marshall, Andrew; Finnigan, Joanne; Morgan, Philip; Efron, Nathan; Boulton, Andrew J.M.; Malik, Rayaz A.

2010-01-01

140

Ex vivo laser confocal microscopy findings of cultured Acanthamoeba trophozoites  

PubMed Central

Purpose The purpose of the current study was to investigate ex vivo laser confocal microscopic findings of cultured Acanthamoeba trophozoites obtained from Acanthamoeba keratitis patients. Methods Eight cultured samples of Acanthamoeba trophozoites from eight eyes of seven patients (mean age, 26.9 years; age range, 18–52 years) were used. Seven samples were from corneal scrapings of Acanthamoeba keratitis patients and one sample was from the solution in a soft contact lens case. Ex vivo laser confocal microscopy was performed to qualitatively evaluate the shape and degree of light reflection of the living Acanthamoeba trophozoites. Results Ex vivo laser confocal microscopy demonstrated highly reflective, high-contrast Acanthamoeba trophozoites with no walls (mean size, 25.4 ?m; range, 17.1–58.5 ?m). The shapes of the trophozoites were highly pleomorphic, and some showed characteristic acanthopodia by laser confocal microscopy. Conclusion Ex vivo laser confocal microscopy was effective in demonstrating cultured Acanthamoeba trophozoites of various shapes and sizes. The observations of the current study may be helpful when similar structures are identified under in vivo conditions.

Yamazaki, Natsuko; Kobayashi, Akira; Yokogawa, Hideaki; Ishibashi, Yasuhisa; Oikawa, Yosaburo; Tokoro, Masaharu; Sugiyama, Kazuhisa

2012-01-01

141

Simplified equation to extract diffusion coefficients from confocal FRAP data.  

PubMed

Quantitative measurements of diffusion can provide important information about how proteins and lipids interact with their environment within the cell and the effective size of the diffusing species. Confocal fluorescence recovery after photobleaching (FRAP) is one of the most widely accessible approaches to measure protein and lipid diffusion in living cells. However, straightforward approaches to quantify confocal FRAP measurements in terms of absolute diffusion coefficients are currently lacking. Here, we report a simplified equation that can be used to extract diffusion coefficients from confocal FRAP data using the half time of recovery and effective bleach radius for a circular bleach region, and validate this equation for a series of fluorescently labeled soluble and membrane-bound proteins and lipids. We show that using this approach, diffusion coefficients ranging over three orders of magnitude can be obtained from confocal FRAP measurements performed under standard imaging conditions, highlighting its broad applicability. PMID:22984916

Kang, Minchul; Day, Charles A; Kenworthy, Anne K; DiBenedetto, Emmanuele

2012-10-10

142

FUNDAMENTAL AREAS OF PHENOMENOLOGY (INCLUDING APPLICATIONS): Measurement of Refractive Index for High Reflectance Materials with Terahertz Time Domain Reflection Spectroscopy  

NASA Astrophysics Data System (ADS)

A method to measure the refractive index for high reflectance materials in the terahertz range with terahertz time domain reflection spectroscopy is proposed. In this method, the THz waveforms reflected by a silicon wafer and high reflectance sample are measured respectively. The refractive index of the silicon wafer, measured with the THz time domain transmission spectroscopy, is used as a reference in the THz time domain reflective spectroscopy. Therefore, the complex refractive index of the sample can be obtained by resorting to the known reflective index of the silicon and the Fresnel law. To improve the accuracy of the phase shift, the Kramers-Kronig transform is adopted. This method is also verified by the index of the silicon in THz reflection spectroscopy. The bulk metal plates have been taken as the sample, and the experimentally obtained metallic refractive indexes are compared with the simple Drude model.

Sun, Wen-Feng; Wang, Xin-Ke; Zhang, Yan

2009-11-01

143

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

PubMed Central

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

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

2009-01-01

144

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

ERIC Educational Resources Information Center

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

Blackwell, H. Richard

1963-01-01

145

Application of NIR reflectance spectroscopy for the identification of pharmaceutical excipients  

Microsoft Academic Search

For manufacturing of medicaments, all ingredients must be reliably identified. Wet chemistry methods for identification of cellulose ethers, used by the Pharmacopoea Europea, is time consuming and expensive. To distinguish microcristalline and powdered cellulose, only unspecific sedimentation properties are used. However, applications as well as technological and pharmacokinetic properties of cellulose and various cellulose ethers are different.NIR reflectance spectroscopy speeds

K Krämer; S Ebel

2000-01-01

146

Universal Design for Learning in Postsecondary Education: Reflections on Principles and their Application  

ERIC Educational Resources Information Center

Authored by the teaching staff of T-560: Meeting the Challenge of Individual Differences at the Harvard Graduate School of Education, this article reflects on potential applications of universal design for learning (UDL) in university courses, illustrating major points with examples from T-560. The article explains the roots of UDL in cognitive…

Rose, David H.; Harbour, Wendy S.; Johnston, Catherine Sam; Daley, Samantha G.; Abarbanell, Linda

2006-01-01

147

A Novel Photodiode for Reflectance Pulse Oximetry in low-power applications  

Microsoft Academic Search

The amount of light collected is crucial for low-power applications of pulse oximetry. In this work a novel ring-shaped backside photodiode has been developed for a wearable reflectance pulse oximeter. The photodiode is proven to work with a dual LED with wavelengths of 660 nm and 940 nm. For the purpose of continuously monitoring vital signs of a human, a

Rasmus G. Haahr; Sune Duun; Karen Birkelund; Palle Raahauge; Peter Petersen; Henrik Dam; L. Norgaard; Erik V. Thomsen

2007-01-01

148

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

NASA Astrophysics Data System (ADS)

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

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

2011-12-01

149

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

SciTech Connect

We develop a diagrammatic representation of the Casimir energy of a multibody configuration. The diagrams represent multiple reflections between the objects and can be organized by a few simple rules. The lowest-order diagrams (or reflections) give the main contribution to the Casimir interaction which proves the usefulness of this expansion. Among some applications of this, we find analytical formulae describing the interaction between edges, i.e. semi-infinite plates, where we also give a first example of blocking in the context of the Casimir energy. We also find the interaction of edges with a needle and describe analytically a recent model of the repulsion due to the Casimir interaction.

Maghrebi, Mohammad F. [Center for Theoretical Physics, and Department of Physics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States)

2011-02-15

150

Nano-displacement measurement based on virtual pinhole confocal method  

NASA Astrophysics Data System (ADS)

A virtual pinhole confocal system based on charge-coupled device (CCD) detection and image processing techniques is built to measure axial displacement with 10 nm resolution, preeminent flexibility and excellent robustness when facing spot drifting. Axial displacement of the sample surface is determined by capturing the confocal laser spot using a CCD detector and quantifying the energy collected by programmable virtual pinholes. Experiments indicate an applicable measuring range of 1000 nm (Gaussian fitting r = 0.9902) with a highly linear range of 500 nm (linear fitting r = 0.9993). A concentric subtraction algorithm is introduced to further enhance resolution. Factors affecting measuring precision, sensitivity and signal-to-noise ratio are discussed using theoretical deductions and diffraction simulations. The virtual pinhole technique has promising applications in surface profiling and confocal imaging applications which require easily-customizable pinhole configurations.

Li, Long; Kuang, Cuifang; Xue, Yi; Liu, Xu

2013-03-01

151

A Review of Airborne Reflected GPS Signal Processing Results for Ocean, Land and Ice Remote Sensing Applications  

Microsoft Academic Search

Global Positioning System (GPS) signals reflected from ocean, land or ice surfaces have the potential to be used for various remote sensing applications. Possibilities for ocean reflections include measurements of surface roughness characteristics from which wind speed and wind direction could be determined. Land reflected GPS measurements could provide us with the unique opportunity to determine soil moisture content. Furthermore,

A. Komjathy; M. Armatys; D. Masters; P. Axelrad; V. U. Zavorotny; S. J. Katzberg

2001-01-01

152

On detecting reflections in presence of scattering from amplitude statistics with application to D region partial reflections  

Microsoft Academic Search

A qualitative model for scattering and weak reflections of HF radiowaves from simple D region structures is described, which uses the received signal to discriminate a single dominant reflector from a background clutter of scatterers\\/reflectors. The behavior of mean, skewness, and kurtosis of the normalized reflected component up to the fourth order, and the use of correlation time scales to

P. K. Rastogi; Olav Holt

1981-01-01

153

Hybrid hyperchromats for chromatic confocal sensor systems  

NASA Astrophysics Data System (ADS)

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

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

2012-07-01

154

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

NASA Astrophysics Data System (ADS)

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

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

1999-06-01

155

Evaluating confocal microscopy system performance.  

PubMed

A confocal microscope was evaluated with a series of tests that measure field illumination, lens clarity, laser power, laser stability, dichroic functionality, spectral registration, axial resolution, scanning stability, PMT quality, overall machine stability, and system noise. These tests will help investigators measure various parameters on their confocal microscopes to insure that they are working correctly with the necessary resolution, sensitivity, and precision. Utilization of this proposed testing approach will help eliminate some of the subjectivity currently employed in assessing the CLSM performance. PMID:24052361

Zucker, Robert M

2014-01-01

156

Application of genetic algorithms to processing of reflectance spectra of semiconductor compounds  

NASA Astrophysics Data System (ADS)

The basic task of mathematical processing of reflectance spectra is the calculation of the dielectric function of the substance, which describe response of a crystal to an external electromagnetic field. The most modern and perspective way of the solution of this task is the dispersion analysis [Lorentz model (LM)]. However LM requires large volume of computing works at phonons optimum parameters selection. The rapid computer facilities development promotes overcoming of this difficulty. However without application of effective methods of optimization practically it is impossible to execute DA for composite reflectance spectra. The efficiency GA strongly depends on such details, as a solutions coding method, genetic operations embodying, selection mechanisms, other algorithm parameters adjustment, success criterion. In this paper we offer modification GA for the solution of the reflectance spectra processing problem and results of the obtained algorithm work.

Zaharov, Ivan S.; Kochura, Alexey V.; Kurkin, Alexandr Y.; Belogorohov, Alexandr I.

2004-11-01

157

Anti-reflection resonance in distributed Bragg reflectors-based ultrathin highly absorbing dielectric and its application in solar cells  

NASA Astrophysics Data System (ADS)

We present a design of anti-reflection resonance in distributed Bragg reflectors (DBRs) based ultrathin highly absorbing dielectric. In such structure, anti-reflection resonance can be supported at wavelengths much longer than those achieved by the previous metal-based structure due to the appropriate reflection phase from the DBRs surface. The proposed anti-reflection resonance can find applications in thin-film organic solar cells for light trappings. By replacing partial metal electrode with DBRs to provide the desired reflection phase, the overall absorptivity can be greatly increased by ~31% due to the good matching between anti-reflection resonance and high-absorption range of the active layers.

Zhang, Xu-Lin; Song, Jun-Feng; Li, Xian-Bin; Feng, Jing; Sun, Hong-Bo

2013-03-01

158

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

159

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

160

Confocal microscopy of cardiac myocytes.  

PubMed

Detailed methods are provided for the preparation and confocal imaging of cardiac myocyte development and differentiation. Examples include protocols for the analysis of cultured myocytes as well as vibratome sections of hearts from embryonic and adult tissue. Techniques include routine labeling of F-actin with phalloidin as well as multiple labeling protocols for colocalization studies and cell volume analysis. PMID:24052352

Price, Robert L; Haley, Stephen T; Bullard, Tara; Davis, Jeffrey; Borg, Thomas K; Terracio, Louis

2014-01-01

161

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

Microsoft Academic Search

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

Kim E. Sapsford

162

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

PubMed Central

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

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

2012-01-01

163

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

SciTech Connect

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

Liu, Z.; Sun, J. G.; Pei, Z. (Nuclear Engineering Division); (Kansas State Univ.)

2011-03-01

164

On the use of GPR energetic reflection coefficients in glaciological applications  

NASA Astrophysics Data System (ADS)

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

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

2009-04-01

165

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

166

Combined reflection and transmission microscope for telemedicine applications in field settings  

PubMed Central

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.

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

2011-01-01

167

A multi-point scanner for high frame rate confocal microendoscopy  

Microsoft Academic Search

Slit-scanning geometries for confocal microendoscopy represent a compromise between acquisition rate and optical performance. Such systems provide high frame rates that freeze motion but recent Monte Carlo simulations show that scattered light severely limits the practical imaging depth for in vivo applications. A new multi-point scanning architecture for confocal microendoscopy has been developed. The new scanner is based on a

Andrew R. Rouse; Houssine Makhlouf; Anthony A. Tanbakuchi; Arthur F. Gmitro

2010-01-01

168

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

Microsoft Academic Search

Normally transparent biological structures in a turbid medium are imaged using a laser confocal microscope and multiwavelength site-specific fluorescence labelling. The spatial filtering capability of the detector pinhole in the confocal microscope limits the number of scattered fluorescent photons that reach the photodetector. Simultaneous application of different fluorescent markers on the same sample site minimizes photobleaching by reducing the excitation

Caesar Saloma; Cynthia Palmes-Saloma; Hisato Kondoh

1998-01-01

169

The Application of Specular X-ray Reflectivity to Characterize Patterned Surface  

NASA Astrophysics Data System (ADS)

Specular x-ray reflectivity (SXR) has been used extensively for thin film characterization and depth profiling. Recently its application has been extended to quantify nanoscale patterns made of photo lithographic polymers. SXR results complement small angle x-ray scattering measurements by providing details information in the cross section of features on nanoscale surface patterns. This talk is to focus on the limit of applying SXR as an effective surface pattern metrology. Polymeric line gratings with periodicities or pitch ranging from 200 nm to 16 ?m were chosen as test samples and it is expected that as the pitch size reaches beyond the coherent length of x-ray SXR will no longer be applicable. The optics of the SXR instrument dictates the coherent length of the x-ray; it provides a coherent length of a few micrometers in the longitudinal direction and sub-micrometers along the lateral direction on the reflection plane and a few nanometers along the lateral direction perpendicular to the reflection plane. SXR measurements were made at various azimuthal angles between the incident x-ray beam and the line grating, with 0 being the incident beam parallel to the line grating and 90 being perpendicular to each other. For periodicities less than 900 nm, the perpendicular and parallel measurements yield comparable SXR results which can be quantitatively analyzed using a one-dimensional model invoking effective medium approximation (EMA), i.e. SXR measures the lateral average electron density of the surface pattern. For periodicities 900 nm and greater, EMA breaks down and the SXR results can not be analyzed using any one-dimensional model. Work is on-going to determine the nature of transition between the EMA applicable region and the inapplicable region. The effect of surface patterns irregularity on this SXR application is another topic of current study.

Wu, Wen-Li; Lee, Hae-Jeong; Soles, Christopher L.

2007-03-01

170

Dye-Enhanced Multimodal Confocal Imaging of Brain Cancers  

NASA Astrophysics Data System (ADS)

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

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

2011-04-01

171

Differential confocal technology based on radial birefringent pupil filtering principle  

NASA Astrophysics Data System (ADS)

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

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

2012-04-01

172

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

SciTech Connect

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

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

1994-05-01

173

Tracheobronchial Amyloidosis and Confocal Endomicroscopy  

Microsoft Academic Search

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

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

2011-01-01

174

Chromatic Confocal Spectral Interferometry — (CCSI)  

Microsoft Academic Search

In the present communication, we addressed the hybrid technique of Chromatic-Confocal Spectral-Interferometry (CCSI). A number\\u000a of recent developments have proved the feasibility of encoding the depth information of topological measurements into the\\u000a spectrum of broad-bandwidth low-coherent light sources. The loss of contrast arising in SI measurements when high NA is employed\\u000a were discussed, and how this discrepancy is lifted by

Evangelos Papastathopoulos; Klaus Körner; Wolfgang Osten

175

Simplified confocal microscope for counting particles at low concentrations  

NASA Astrophysics Data System (ADS)

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

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

2013-07-01

176

Non destructive analysis of the wax layer of apple ( Malus domestica Borkh.) by means of confocal laser scanning microscopy  

Microsoft Academic Search

Confocal laser scanning microscopy (CLSM) was used to non-destructively analyse the changes in the structure and thickness of the cuticle during storage of apples (Malus domestica Borkh.). Interpretation of the confocal images was performed by comparison with scanning electron microscopy and environmental scanning electron microscopy images. The natural reflectance of the wax and the auto-fluorescence of the underlying cells made

Els A. Veraverbeke; Nathalie Van Bruaene; Patrick Van Oostveldt; Bart M. Nicolaï

2001-01-01

177

Confocal Raman microspectroscopy of the skin.  

PubMed

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

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

178

3D isochronal modelling of reflections from the deep crust: application to reflection profiling in central Australia  

NASA Astrophysics Data System (ADS)

Reflection profiling of the whole crust across ancient terranes encounters a range of interpretational problems and ambiguities, especially with regard to the geometry of faults. Such problems can be addressed by Seismic modelling with full inclusion of diffractions and a suitable modelling procedure for such three-dimensional problems is the isochronal technique described by Cao and Kennett (1989).Such modelling has been used to investigate the validity of some of the interpretations of a deep crustal refection profile in central Australia involving planar faults of moderate dip penetrating most of the crust and considerable Moho topography. Even with a relatively short (4 km) field spread it would be possible to detect the reflected energy from faults with dips of about 40°. The character of the reflections also suggests considerable variability in piysical properties within the fault zones. The largest fault, the Redbank Zone, has significant displacement of the Moho. But most of crustal faults appear to sole out into the crust-mantle interface. This gives rise to an undulating Mcho for which Seismic modelling corresponds closely to the observed data.

Cao, Shunhua; Kennett, Brian L. N.; Goleby, Bruce R.

1990-02-01

179

A novel photodiode for reflectance pulse oximetry in low-power applications.  

PubMed

The amount of light collected is crucial for low-power applications of pulse oximetry. In this work a novel ring-shaped backside photodiode has been developed for a wearable reflectance pulse oximeter. The photodiode is proven to work with a dual LED with wavelengths of 660 nm and 940 nm. For the purpose of continuously monitoring vital signs of a human, a temperature sensor is integrated onto the chip containing the photodiode. This biomedical multisensor chip is made for integration into "the Electronic Patch", an autonomous monitoring system for humans. PMID:18002464

Haahr, Rasmus G; Duun, Sune; Birkelund, Karen; Raahauge, Palle; Petersen, Peter; Dam, Henrik; Nørgaard, Lars; Thomsen, Erik V

2007-01-01

180

Study of liquid jet instability by confocal microscopy.  

PubMed

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. PMID:22852668

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

2012-07-01

181

Simulation of imaging with a theta line-scanning confocal microscope  

Microsoft Academic Search

We describe a 2-D computational model of the optical propagation of coherent light from a laser diode within human skin to improve our understanding of the performance of a confocal reflectance theta microscope. The simulation uses finite-difference time-domain (FDTD) computations to solve Maxwell's equations in a synthetic skin model that includes melanin, mitochondria, and nuclei. The theta line-scanning confocal microscope

Blair Simon; Charles A. DiMarzio

2008-01-01

182

Confocal Microscopy in the Esophagus and Stomach  

PubMed Central

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

Templeton, Adam

2013-01-01

183

Automated Confocal Microscope Bias Correction  

NASA Astrophysics Data System (ADS)

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

Dorval, Thierry; Genovesio, Auguste

2006-10-01

184

Analysis of multidimensional confocal images  

NASA Astrophysics Data System (ADS)

A confocal image understanding system was developed which uses the blackboard model of problem solving to achieve computerized identification and characterization of confocal fluorescent images (serial optical sections). The system is capable of identifying a large percentage of structures (e.g., cell nucleus) in the presence of background noise and nonspecific staining of cellular structures. The blackboard architecture provides a convenient framework within which a combination of image processing techniques can be applied to successively refine the input image. The system is organized to find the surfaces of highly visible structures first, using simple image processing techniques, and then to adjust and fill in the missing areas of these object surfaces using external knowledge, and a number of more complex image processing techniques when necessary. As a result, the image analysis system is capable of obtaining morphometrical parameters such as surface area, volume and position of structures of interest automatically. In addition, the system is also used in the characterization of inertial fusion targets where the actual target geometry was checked against ideal parameters. The system provides a powerful tool in the fields of material science and biological research such as micro-structural characterization, morphogenesis, cell differentiation, tissue organization and embryo development.

Samarabandu, Jagath K.; Acharya, Raj S.; Edirisinghe, Chandima D.; Cheng, Ping C.; Kim, Hyo-Gun; Lin, T. H.; Summers, R. G.; Musial, C. J.

1991-07-01

185

Design and demonstration of multimodal optical scanning microscopy for confocal and two-photon imaging.  

PubMed

We developed a multimodal microscopy based on an optical scanning system in order to obtain diverse optical information of the same area of a sample. Multimodal imaging researches have mostly depended on a commercial microscope platform, easy to use but restrictive to extend imaging modalities. In this work, the beam scanning optics, especially including a relay lens, was customized to transfer broadband (400-1000 nm) lights to a sample without any optical error or loss. The customized scanning optics guarantees the best performances of imaging techniques utilizing the lights within the design wavelength. Confocal reflection, confocal fluorescence, and two-photon excitation fluorescence images were obtained, through respective implemented imaging channels, to demonstrate imaging feasibility for near-UV, visible, near-IR continuous light, and pulsed light in the scanning optics. The imaging performances for spatial resolution and image contrast were verified experimentally; the results were satisfactory in comparison with theoretical results. The advantages of customization, containing low cost, outstanding combining ability and diverse applications, will contribute to vitalize multimodal imaging researches. PMID:23387653

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

2013-01-01

186

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

EPA Science Inventory

Evaluation of confocal microscopy system performance: Pretty pictures or confocal QA? Robert M. Zucker Reproductive Toxicology Division, National Health and Environmental Effects Research Laboratory, U.S. Environmental Protection Agency, Research Triangle Park, N...

187

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

188

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

189

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

190

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

191

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

192

Multiplanar OCT/confocal ophthalmoscope in the clinic  

NASA Astrophysics Data System (ADS)

This paper demonstrates the clinical application of a multiplanar imaging system, which simultaneously acquires en-face (C-scan) OCT and corresponding confocal ophthalmoscopic images along with cross-sectional (B-scan) OCT at cursor designated locations on the confocal image. Advantages of the simultaneous OCT/confocal acquisition as well as the challenges of interpreting the C-scan OCT images are discussed. Variations in tissue inclination with respect to th coherence wave surface alters the sampling of structures within the depth in the retina, producing novel slice orientations which are often challenging to interpret. We evaluate for the first time the utility of C-scan OCT for a variety of pathologies including exudative ARMD, macular hole, central serous retinopathy, diabetic retinopathy, polypoidal choroidal vasculopathy and macular pucker. Several remarkable observations of new aspects of clinical anatomy were noted. The versatility of selective capture of C-scan OCT images and B-scan OCT images at precise points on the confocal image affords the clinician a more complete and interactive tool for 3D imaging of retinal pathology.

Rosen, Richard B.; Podoleanu, Adrian Gh.; Rogers, John A.; Dunne, Shane; Dobre, George M.; Cucu, Radu G.; Jackson, David A.; Garcia, Patricia; Orlock, Dennis A.; Yannuzzi, Lawrence A.; Fisher, Yale; Nieto, Juan; Gentile, Ronald C.; Rosenthal, Jeanne L.; Muldoona, Thomas O.; Walsh, Joseph B.; Costa, Danielle; Huang, Sheau; Slakter, Jason; Spaide, Richard

2003-07-01

193

Confocal microscopy on the beamline: novel three-dimensional imaging and sample positioning.  

PubMed

Confocal microscopy, a technique that has been extensively applied in cellular biological studies, may also be applied to the visualization and three-dimensional imaging of protein crystals at high resolution on synchrotron beamlines. Protein crystal samples are examined using a commercially available confocal microscope adapted for cryogenic use. A preliminary test using a custom confocal design adapted for beamline use is also presented. The confocal optics configuration is compatible with nonlinear imaging techniques such as two-photon excited fluorescence imaging and second harmonic generation. The possibilities of this method are explored using two modes: fluorescence and reflection confocal. In fluorescence mode, small amounts of dye are introduced into the crystal through soaking or growth conditions. Under such conditions, protein crystals are easily resolved from salts and amorphous precipitates, which do not generally take up dye. Reflection mode, which does not require dye, still exhibits greater resolution and sensitivity to surface detail than conventional wide-field microscopy as a result of the confocal optics configuration. The inherent three-dimensional nature of the method means that on-axis sample views (along the direction of the X-ray beam) can be reconstructed from an off-axis configuration, simplifying the beamline setup and providing uniquely detailed views of cryogenically cooled crystals. PMID:22997474

Khan, I; Gillilan, R; Kriksunov, I; Williams, R; Zipfel, W R; Englich, U

2012-09-01

194

Confocal microscopy on the beamline: novel three-dimensional imaging and sample positioning  

PubMed Central

Confocal microscopy, a technique that has been extensively applied in cellular biological studies, may also be applied to the visualization and three-dimensional imaging of protein crystals at high resolution on synchrotron beamlines. Protein crystal samples are examined using a commercially available confocal microscope adapted for cryogenic use. A preliminary test using a custom confocal design adapted for beamline use is also presented. The confocal optics configuration is compatible with nonlinear imaging techniques such as two-photon excited fluorescence imaging and second harmonic generation. The possibilities of this method are explored using two modes: fluorescence and reflection confocal. In fluorescence mode, small amounts of dye are introduced into the crystal through soaking or growth conditions. Under such conditions, protein crystals are easily resolved from salts and amorphous precipitates, which do not generally take up dye. Reflection mode, which does not require dye, still exhibits greater resolution and sensitivity to surface detail than conventional wide-field microscopy as a result of the confocal optics configuration. The inherent three-dimensional nature of the method means that on-axis sample views (along the direction of the X-ray beam) can be reconstructed from an off-axis configuration, simplifying the beamline setup and providing uniquely detailed views of cryogenically cooled crystals.

Khan, I.; Gillilan, R.; Kriksunov, I.; Williams, R.; Zipfel, W. R.; Englich, U.

2012-01-01

195

Sonoluminescence optical confocal tomography of tissue  

Microsoft Academic Search

In this paper, we report experiments on optical confocal tomography by use of sonoluminescence signal in both biological tissue and tissue-simulating media. A high- sensitive confocal scanning setup based on photon counting technique was developed. With the system, we obtained images of the objects embedded in tissue-simulating turbid media. The images showed a high contrast and a lateral reso- lution

Yonghong He; D. a. Xing; Yong Yao; Ken-Ichi Ueda

2002-01-01

196

Hyperspectral confocal fluorescence imaging of cells  

Microsoft Academic Search

Confocal fluorescence imaging of biological systems is an important method by which researchers can investigate molecular processes occurring in live cells. We have developed a new 3D hyperspectral confocal fluorescence microscope that can further enhance the usefulness of fluorescence microscopy in studying biological systems. The new microscope can increase the information content obtained from the image since, at each voxel,

David M. Haaland; Howland D. T. Jones; Michael B. Sinclair; Bryan Carson; Catherine Branda; Jens F. Poschet; Roberto Rebeil; Bing Tian; Ping Liu; Allan R. Brasier

2007-01-01

197

EVALUATION OF CONFOCAL MICROSCOPY SYSTEM PERFORMANCE  

EPA Science Inventory

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

198

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

Microsoft Academic Search

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

P. Edenhofer; A. Alpaslan

2005-01-01

199

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

Microsoft Academic Search

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

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

2010-01-01

200

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

NASA Astrophysics Data System (ADS)

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

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

2013-06-01

201

Reflectance Pulse Oximetry – Principles and Obstetric Application in the Zurich System  

Microsoft Academic Search

Transmission and reflectance are the two main modes of pulse oximetry. In obstetrics, due to the absence of a transilluminable fetal part for transmission oximetry, the only feasible option is the reflectance mode, in which sensor and detector are located on the same surface of the body part. However, none of the reflectance pulse oximeters developed for intrapartum use are

Volker König; Renate Huch; Albert Huch

1998-01-01

202

Construction and Application of an Evaluative Tool to Assess Reflection in TeacherTraining Courses  

Microsoft Academic Search

In recent years, the ability to reflect has been considered an important competency that teachers should acquire during teacher training and implement in teaching throughout their professional lives. Thus there is the need during teacher training to assess student teachers' developing reflective abilities. This article describes a two-dimensional framework by which student teachers' written reflections may be assessed. One dimension

Deborah Court; Bracha Kramarski

2002-01-01

203

Measurement of the Topography, Refractive Index and Thickness in Tissues by mean of a Chromatic Confocal Method  

Microsoft Academic Search

The chromatic confocal methods are attractive for various applications, such as imaging of biological samples and semiconductor materials. In this paper a chromatic confocal method to measure the topography, the refractive index and optical thickness of tissues is develop. The experimental model is based on the longitudinal chromatic aberration produced by a diffractive element. The setup is composed by a

Johnson Garzón; Tijani Gharbi; Jaime Meneses

2008-01-01

204

Confocal Fluorescence Microscopy of Mung Beanleaves  

NASA Astrophysics Data System (ADS)

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

Chen, Zhiwei; Liu, Dongwu

205

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

206

Applicability of direct total reflection X-ray fluorescence analysis in the case of human blood serum samples  

Microsoft Academic Search

Total Reflection X-Ray Fluorescence (TXRF) is a well-established method, mainly applied in the analysis of liquid samples, offering very low detection limits in most of the cases. Direct application of the TXRF method is not so efficient in blood serum analysis, since the high content of the organic matrix increases significantly the background due to Compton scattering. Chemical treatment of

Ch. Zarkadas; A. G. Karydas; T. Paradellis

2001-01-01

207

Criteria for Quantitative Dynamical Confocal Fluorescence Imaging.  

National Technical Information Service (NTIS)

Scanning confocal microscopy (SCM) offers a dramatic instrumental advantage for fluorescence microscopy through discrimination against out-of-focus background fluorescence, through inherent resolution perpendicular to the plane of focus and improved in-pl...

W. W. Webb K. S. Wells D. R. Sandison J. Strickler

1990-01-01

208

Reflection and Evidence-Based Practice in Action: A Case Based Application  

Microsoft Academic Search

Reflective practice and evidence-based practice are essential to clinical practice. The former provides a retrospective look at current practice and questions the reason for doing so. The latter provides the means by which best evidence can be used to make foundationally sound and clinically relevant decisions. This article demonstrates the utility of and the dynamics between reflective practice and evidence-based

Ronald De Vera Barredo

209

Application of Dynamical Optical Reflection Thermography (DORT) for detecting of dark current inhomogeneity in semiconductor devices  

Microsoft Academic Search

A novel technique named Dynamical Optical Reflection Thermography (DORT) able to detect the dark current inhomogeneities in semiconductor devices such as solar cells, have been proposed. It is based on the principles of dynamical heating of defect dots by the pulse dark current and registration of the temperature alteration by the measurement of the external reflection from the semiconductor surface.

S. V Litvinenko; S. S Kilchitskaya; V. A Skryshevsky; V. I Strikha; A Laugier

1999-01-01

210

Appearance Measurements in Industry and their Application in Light Reflection Models  

Microsoft Academic Search

We investigate appearance standards in industry for gloss, haze, and goniochromatic color. Ad- vantages of using appearance standards directly connected to physical reflection parameters in- clude the small number of required measurements and the inexpensive commercially available in- struments necessary to acquire the data. We re- view light reflection models recently developed for metallic and pearlescent colors that are accurate

Metod Nam; J. Herdu

211

Haptic Interface using Delayed Reflection Wave: Application to a Passive Haptic Device  

Microsoft Academic Search

It is well known that the wave variables are robust to time delay of a system from the viewpoint of passivity. During implementation of the wave transformation on the sampled-data system, a unit time delay arises due to causality of the reflection wave. The unit time delay on the reflection wave occasionally becomes a passive element. From the passivity condition

Jae-hyeong Lee; Chang-Hyun Cho; Jae-bok Song; Chang-soon Hwang; Munsang Kim

2005-01-01

212

Analytic forms of bidirectional reflectance functions for application to Earth radiation budget studies  

Microsoft Academic Search

Analytic expressions for the bidirectional reflectance functions are formulated and fit to the Earth Radiation Budget Experiment (ERBE) operational models, which were developed using Nimbus 7 ERB data. The analytic bidirectional reflectance distribution functions (BRDFs) are based on theoretical considerations and are functions of viewing geometry and scene type. The models consist of a Rayleigh scattering term and a term

N. Manalo-Smith; G. L. Smith; S. N. Tiwari; W. F. Staylor

1998-01-01

213

Confocal light absorption and scattering spectroscopic microscopy  

NASA Astrophysics Data System (ADS)

We have developed a novel optical method for observing submicrometer intracellular structures in living cells, which is called confocal light absorption and scattering spectroscopic (CLASS) microscopy. It combines confocal microscopy, a well-established high-resolution microscopic technique, with light-scattering spectroscopy. CLASS microscopy requires no exogenous labels and is capable of imaging and continuously monitoring individual viable cells, enabling the observation of cell and organelle functioning at scales of the order of 100 nm.

Fang, Hui; Qiu, Le; Vitkin, Edward; Zaman, Munir M.; Andersson, Charlotte; Salahuddin, Saira; Kimerer, Lauren M.; Cipolloni, Patsy B.; Modell, Mark D.; Turner, Bradley S.; Keates, Sarah E.; Bigio, Irving; Itzkan, Irving; Freedman, Steven D.; Bansil, Rama; Hanlon, Eugene B.; Perelman, Lev T.

2007-04-01

214

Confocal diffraction phase microscopy of live cells.  

PubMed

We present a new quantitative phase microscopy technique, confocal diffraction phase microscopy, which provides quantitative phase measurements from localized sites on a sample with high sensitivity. The technique combines common-path interferometry with confocal microscopy in a transmission geometry. The capability of the technique for static imaging is demonstrated by imaging polystyrene microspheres and live HT29 cells, while dynamic imaging is demonstrated by quantifying the nanometer scale fluctuations of red blood cell membranes. PMID:18794935

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

2008-09-15

215

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

216

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

Microsoft Academic Search

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

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

2002-01-01

217

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

Microsoft Academic Search

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

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

1999-01-01

218

Practical confocal microscopy and the evaluation of system performance.  

PubMed

The laser scanning confocal microscope has enormous potential in many fields of biology. Currently there is a subjective nature in the assessment of a confocal microscope's performance by primarily evaluating the system with a specific test slide provided by the user's laboratory. To achieve better performance from the equipment, it is necessary to run a series of tests to ensure that the optical machine is functioning properly. We have devised these methods on the Leica TCS-SP and TCS-4D systems. Tests measuring field illumination, lens clarity, laser power output, dichroic functioning, spectral alignment, axial resolution, laser power stability, machine performance, and system noise were derived to test the Leica laser scanning confocal microscopy system. These tests should be applicable to other manufacturers' systems as well. The relationship between photomultiplier tube (PMT) voltage, laser power, and averaging using a 10-microm-diameter test bead has shown that the noise (coefficient of variation of bead intensity, CV) in an image increases as the PMT increases. Therefore increasing the PMT setting results in increased noise. For ideal image quality, it appears that it is better to decrease the PMT setting and increase laser power, as noise generated by high PMT settings will reduce the image quality far more than the bleaching caused by higher laser power. Averaging can be used to improve the image at high PMT values, provided the sample is not bleached by repeated passes of the laser. PMID:10491274

Zucker, R M; Price, O T

1999-08-01

219

Laser-excited confocal-fluorescence gel scanner  

SciTech Connect

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

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

1994-04-01

220

Surface roughness and gloss study of prints: application of specular reflection at near infrared  

NASA Astrophysics Data System (ADS)

Absolute reflectance data were measured with a spectrophotometer in the visible and near infrared (NIR) spectral range. The specular reflectance data in the NIR were used for the assessment of the surface roughness of magenta, yellow, cyan and black prints on paper. In addition, surface roughness data obtained from the prints with a mechanical diamond stylus, an optical profiling system and the spectrophotometer are compared with each other. The surface roughness obtained with the aid of the spectrophotometer data suggests a smoother surface than when measured with the diamond stylus and the optical profiling system. The gloss of the prints can be obtained from the absolute specular reflectance spectra in the spectral region of visible light. It is shown that specular reflection data at a fixed wavelength in the NIR are useful also in the interpretation of gloss in the visible spectral range, but using an unconventional grazing angle of incidence.

Silfsten, P.; Dutta, R.; Pääkkönen, P.; Tåg, C.-M.; Gane, P. A. C.; Peiponen, K.-E.

2012-12-01

221

Apparent reflectance and its applications using Resourcesat-1 remote sensing data  

NASA Astrophysics Data System (ADS)

Resourcesat-1(IRS-P6) was built by Indian Space Research Organisation and launched in October, 2003. Resourcesat-1 carries three imaging sensors--a moderate resolution camera Advanced Wide Field Sensor (AWFS), a moderate resolution Linear Imaging Self Scanning-III device (LISS-III) and a high resolution Linear Imaging Self Scanning-IV device (LISS-IV) to get different spatial resolution image. Apparent reflectance of LISS-III image is calculated in Poyang Lake, south of China. The mean Digital Number (DN) in Red Band image of part of this district is 108.9, and Stdev is 62.72. The mean apparent reflectance of this image is 0.17, and Stdev is 0.093. Apparent reflectance can be used in the normalized difference vegetation index (NDVI) calculation, atmospheric correction, and others. NDVI value which is calculated by apparent reflectance can represent surface status accurately.

Li, Shihua; Niu, Zheng

2006-10-01

222

Experimental design for reflection measurements of highly reactive liquid or solid substances with application to liquid sodium. [LMFBR  

SciTech Connect

This technical report describes the experimental part of a program on thermal radiation properties of reactor materials. A versatile goniometer system with associated electronic components and mechanical instruments has been assembled. It is designed to measure spectral, specular reflectances of highly reactive liquid or solid substances over a spectral range of 0.3 ..mu.. to 9 ..mu.. and incidence angles of 12/sup 0/ to 30/sup 0/ off the normal direction. The capability of measuring reflectances of liquid substances clearly distinguishes this experimental design from conventional systems which are applicable only to solid substances. This design has been used to measure the spectral, specular reflectance of liquid sodium and preliminary results obtained are compared with those of solid sodium measured by other investigators.

Chan, S.H.; Gossler, A.A.

1980-06-30

223

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

Microsoft Academic Search

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

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

2003-01-01

224

Some improvements and extensions of the application of specular neutron reflection to the study of interfaces  

NASA Astrophysics Data System (ADS)

The level of the background scattering in neutron reflection experiments limits the range of momentum transfer over which a specular reflectivity profile may be measured and also makes it difficult to observe off-specular scattering. A further limitation of neutron reflection, which applies to studies of the solid/liquid interface, restricts accessibility to a small range of solid surface. The restriction of specular reflection measurements to below a relatively small value of ?max means that the intrinsic resolution of specular neutron reflection is low. We show how selective isotopic labelling can be used to enhance the resolution beyond the limit determined by ?max and illustrate the method using the structure of hexadecyl trimethyl ammonium bromide as an example. For the range of coverages typical of a surfactant monolayer at the air/water interface the structure can be resolved to the level of a group of three to four carbon atoms. The difficulty of extending neutron reflection at the solid/liquid interface to different solids is that the large size of solid sample and the requirement that the solid usually be crystalline makes the cost of the solid material prohibitively high except for a small range of materials which include silicon, amorphous silica and crystalline quartz. We give examples that show how self-assembled monolayers with different chemical functionality on their outer surfaces can be used to create a wide variety of different surfaces with quite different adsorptive behaviour. This should greatly extend the range of neutron reflection experiments on the important solid/liquid interface. The lamellar phase of the surfactant Aerosol-OT adsorbs preferentially from a mixture of lamellar phase and isotropic solution at both air/liquid and solid/liquid interfaces. Strong off-specular scattering from fluctuations in the lamellae is observed which is enhanced by Bragg diffraction from the multilayer structure. This indicates that there must be partial correlation of the fluctuations in different lamellae.

Li, Z. X.; Thirtle, P. N.; Weller, A.; Thomas, R. K.; Penfold, J.; Webster, J. R. P.; Rennie, A. R.

1998-06-01

225

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

NASA Astrophysics Data System (ADS)

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

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

2013-06-01

226

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

SciTech Connect

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

Medley, S.S.

1998-05-01

227

Application of near infrared reflectance spectroscopy to predict meat and meat products quality: A review  

Microsoft Academic Search

Over the past three decades, near infrared reflectance (NIR) spectroscopy has been proved to be one of the most efficient and advanced tools for the estimation of quality attributes in meat and meat products. This review focuses on the use of NIR spectroscopy to predict different meat properties, considering the literature published mainly in the last decade. Firstly, the potential

N. Prieto; R. Roehe; P. Lavín; G. Batten; S. Andrés

2009-01-01

228

X-ray multilayer-coated reflection gratings: theory and applications  

Microsoft Academic Search

Among the various rigorous electromagnetic methods previously developed in order to compute and optimize grating efficiencies, Differential Formalism turns out to be the only one capable of dealing with reflection gratings in the x ray region. Not only can the method tackle bare gratings, but it is generalized in order to handle a multilayer stack deposited on top of a

Michel Neviere; Antonius J. den Boggende

1991-01-01

229

Application of a two-region kinetic model for reflected reactors to experimental data  

SciTech Connect

Reflected reactors constitute one of the most important classes of nuclear reactors. Yet, during the past 50 yr, a plethora of experimental data involving reflected systems has been reported in the literature that cannot be satisfactorily explained using the {open_quotes}standard{close_quotes} (i.e., one-region) point-kinetic model. In particular, many have observed that the prompt-decay a curves obtained from Rossi-{alpha} and pulsed-neutron experiments can exhibit multiple decay modes in the vicinity near delayed critical in some types of reflected systems. When analyzed using theories based on the standard point-kinetic model, these data yielded system lifetimes that do not always agree well with the lifetimes predicted by numerical solutions of the multigroup, multidimensional diffusion or transport equations. In several cases, when the longest lived decay mode (i.e., the dominant root) was plotted as a function of reactivity, the a curve intercepted the reactivity axis at a reactivity significantly greater than 1$. Brunson dubbed this seemingly inexplicable behavior as the {open_quotes}dollar discrepancy.{close_quotes} Furthermore, it has also been observed that the kinetic behavior of some reflected, fast-burst assemblies exhibits a very pronounced nonlinear relationship between reactivity and the initial inverse period for reactivity insertions > 1 $.

Busch, R.D. [Univ. of New Mexico, Albuquerque, NM (United States); Spriggs, G.D. [Los Alamos National Laboratory, NM (United States); Williams, J.G. [Univ. of Arizona, Tucson, AZ (United States)

1996-12-31

230

Mind the body!: designing a mobile stress management application encouraging personal reflection  

Microsoft Academic Search

We have designed a stress management biofeedback mobile service for everyday use, aiding users to reflect on both positive and negative patterns in their behavior. To do so, we embarked on a complex multidisciplinary design journey, learning that: detrimental stress results from complex processes related to e.g. the subjective experience of being able to cope (or not) and can therefore

Pedro Sanches; Kristina Höök; Elsa Kosmack Vaara; Claus Weymann; Markus Bylund; Pedro Ferreira; Nathalie Peira; Marie Sjölinder

2010-01-01

231

Instantaneous spectral bandwidth and dominant frequency with applications to seismic reflection data  

Microsoft Academic Search

Fourier power spectra are often usefully characterized by average measures. In reflection seismology, the important average measures are center frequency, spectral bandwidth, and dominant frequency. These quantities have definitions familiar from probability theory: center frequency is the spectral mean, spectral bandwidth is the standard deviation about that mean, and dominant frequency is the square root of the second moment, which

Arthur E. Barnes

1993-01-01

232

Toward a dependable measure of reflection-impulsivity: An application of generalizability theory  

Microsoft Academic Search

Generalizability theory was applied to the Matching Familiar Figures Test (MFF) to analyze the dependability of the MFF as a measure of reflection-impulsivity at four grade levels: second, third, fourth, and fifth. A completely crossed, two-facet random model design was used to provide a multidimensional framework for examining the dependability of the MFF. Components of variance and coefficients of generalizability

John M. Watkins; Howard B. Lee; Oded Erlich

1980-01-01

233

Reflecting Reflective Practice  

ERIC Educational Resources Information Center

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

Galea, Simone

2012-01-01

234

Laboratory infrared reflection spectrum of carbon dioxide clathrate hydrates for astrophysical remote sensing applications  

NASA Astrophysics Data System (ADS)

We present 1-5 ?m IR reflectance spectra of CO2 clathrate hydrates acquired under temperature and pressure conditions representative of the icy moons' surfaces. The IR reflectance spectrum of the CO2 clathrate hydrates is similar to the water ice IR reflectance spectrum except for two main absorption bands corresponding to the CO2 guest molecule at 2.71 and 4.28 ?m (3693 and 2334 cm-1). The specific configuration of the clathrate hydrate structure is identified through the ?3 absorption band splitting which produces a band at 4.26 ?m (2347 cm-1) for molecules trapped in small cages and a band at 4.28 ?m (2334 cm-1) for molecules trapped in large cages. In general, the reflection spectra are similar to spectra obtained in transmission spectroscopy. But, it appears that the aspect of the ?3 absorption band is strongly influenced by physical (roughness, thickness, mixing properties) and optical (n and k) characteristics of the sample. A qualitative discussion of the effects of these sample properties on near-IR signatures of clathrate hydrates is proposed. Finally, a comparison between the absorption bands of CO2 clathrate hydrates obtained in this work and CO2 absorption bands as detected by VIMS on the icy satellites of Saturn is achieved. The experimental near-IR reflection spectra, made in pressure-temperature (P-T) conditions close to those of the icy surfaces, confirm that VIMS data are not consistent with the presence of structure I CO2 clathrate hydrates on the surface of the icy moons.

Oancea, Adriana; Grasset, Olivier; Le Menn, Erwan; Bollengier, Olivier; Bezacier, Lucile; Le Mouélic, Stéphane; Tobie, Gabriel

2012-11-01

235

Confocal light scattering and absorption spectroscopic microscopy  

NASA Astrophysics Data System (ADS)

We have developed a novel optical method for observing submicron intracellular structures in living cells which is called confocal light absorption and scattering spectroscopic (CLASS) microscopy. It combines confocal microscopy, a well-established high-resolution microscopic technique, with light scattering spectroscopy (LSS). CLASS microscopy requires no exogenous labels and is capable of imaging and continuously monitoring individual viable cells, enabling the observation of cell and organelle functioning at scales on the order of 100 nm. In addition, it provides not only size information but also information about the biochemical and physical properties of the cell.

Qiu, Le; Vitkin, Edward; Salahuddin, Saira; Zaman, Munir M.; Andersson, Charlotte; Freedman, Steven D.; Hanlon, Eugene B.; Itzkan, Irving; Perelman, Lev T.

2008-05-01

236

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

SciTech Connect

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

Eisenberg, J

2001-04-09

237

Wide field-of-view all-reflective objectives designed for multispectral image acquisition in photogrammetric applications  

NASA Astrophysics Data System (ADS)

In many aerial and close-range photogrammetry applications, the near infrared (NIR) spectral range is required in addition to the visible (VIS) spectral range. Currently, many especially aerial photogrammetric systems use particularly optimized camera systems for each spectral band. Using separate cameras or lenses can introduce parallaxes and timedelays between the acquired images, and thus complicate the data fusion process. Furthermore, it adds additional weight to the entire system. With an image acquisition through a single objective, the complexity of the data fusion and the weight can be significantly reduced. However, to be able to only use one objective for different spectral bands, the optical system has to be free of chromatic aberrations. For photogrammetric applications, a wide field-of-view and a high resolution are frequent additional requirements. Therefore, we will present a design and an adapted photogrammetric calibration method of an all-reflective unobscured optical system optimized for full-frame imaging sensors. All-reflective unobscured optical systems may also be a very efficient imaging tool in combination with unmanned aerial vehicles (UAVs). Due to the limited payload capacity, many currently available UAVs can only be used with one spectrally limited camera system at the same time. With miniaturized all-reflective camera systems, the image data could be acquired in the visible and e.g. the NIR spectral range simultaneously.

Seidl, Kristof; Richter, Katja; Knobbe, Jens; Maas, Hans-Gerd

2011-09-01

238

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

NASA Astrophysics Data System (ADS)

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

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

2008-12-01

239

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

SciTech Connect

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

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

2005-05-01

240

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

241

Multivariate Data Analysis on Tissue Diffuse Reflectance Spectra for Diagnostic Applications  

NASA Astrophysics Data System (ADS)

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

Prince, Shanthi; Malarvizhi, S.

2011-10-01

242

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

243

Application of infrared spectroscopy (attenuated total reflection) for monitoring enzymatic activity on substrate films  

Microsoft Academic Search

Infrared film analysis, a method based on infrared spectroscopy in the mode of attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR), is demonstrated as a novel analytical method for monitoring enzymatic activity on surface-attached substrate films in the mid infrared range (400–4000 cm?1). The ATR-FTIR technique is sensitive to molecules within a distance of approximately 1 ?m from the ATR

Torben Snabe; Steffen Bjørn Petersen

2002-01-01

244

High Count Rates with Total Internal Reflection Fluorescence Correlation Spectroscopy  

Microsoft Academic Search

We achieved photon count rates per molecule as high as with commonly used confocal fluorescence correlation spectroscopy instruments using a new total internal reflection fluorescence correlation spectroscopy system based on an epi-illumination configuration.

Kai Hassler; Tiemo Anhut; Rudolf Rigler; Michael Gösch; Theo Lasser

2005-01-01

245

Anti-Reflective Fluoride Coatings for Widely Tunable Deep-Ultraviolet Diode-Pumped Solid-State Laser Applications  

NASA Astrophysics Data System (ADS)

An anti-reflective (AR) fluoride coating in the 170-230 nm spectral range is prepared by the thermal evaporation method for the applications of widely tunable deep-ultraviolet diode-pumped solid-state lasers. The transmittance of an AR coated calcium fluoride (CaF2) window in thickness 3 mm is measured to be in the range of 95.8% at 170 nm to 97.1% at 230 nm, with the maximum transmittance 99.2% and the minimum residual reflectance 0.04% appeared at 195 nm. The experimental results indicate that treating the AR coated window and the bare substrate with ultraviolet irradiation can significantly improve their optical performance.

Li, Bin-Cheng; Lin, Da-Wei; Han, Yan-Ling; Guo, Chun; Zhang, Yun-Dong; Liu, Hong-Xiang

2010-04-01

246

Total reflection X-ray fluorescence trace mercury determination by trapping complexation: Application in advanced oxidation technologies  

NASA Astrophysics Data System (ADS)

It is well known that Hg species cause high noxious effects on the health of living organisms even at very low levels (5 ?g/L). Quantification of this element is an analytical challenge due to the peculiar physicochemical properties of all Hg species. The regulation of the maximal allowable Hg concentration led to search for sensitive methods for its determination. Total reflection X-ray fluorescence is a proved instrumental analytical tool for the determination of trace elements. In this work, the use of total reflection X-ray fluorescence for Hg quantification is investigated. However, experimental determination by total reflection X-ray fluorescence requires depositing a small volume of sample on the reflector and evaporation of the solvent until dryness to form a thin film. Because of volatilization of several Hg forms, a procedure to capture these volatile species in liquid samples by using complexing agents is proposed. Acetate, oxalic acid, ethylenediaminetetracetic acid and ammonium pyrrolidine-dithiocarbamate were assayed for trapping the analytes into the solution during the preparation of the sample and onto the reflector during total reflection X-ray fluorescence measurements. The proposed method was applied to evaluate Hg concentration during TiO 2-heterogeneous photocatalysis, one of the most known advanced oxidation technologies. Advanced oxidation technologies are processes for the treatment of effluents in waters and air that involve the generation of very active oxidative and reductive species. In heterogeneous photocatalysis, Hg is transformed to several species under ultraviolet illumination in the presence of titanium dioxide. Total reflection X-ray fluorescence was demonstrated to be applicable in following the extent of the heterogeneous photocatalysis reaction by determining non-transformed Hg in the remaining solution.

Custo, Graciela; Litter, Marta I.; Rodríguez, Diana; Vázquez, Cristina

2006-11-01

247

Interference Reflectance Microscopy  

PubMed Central

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

Barr, Valarie A.; Bunnell, Stephen C.

2010-01-01

248

Three-dimensional reconstruction from multiple reflected views within a realist painting: an application to Scott Fraser's "Three way vanitas"  

NASA Astrophysics Data System (ADS)

The problem of reconstructing a three-dimensional scene from single or multiple views has been thoroughly studied in the computer vision literature, and recently has been applied to problems in the history of art. Criminisi pioneered the application of single-view metrology to reconstructing the fictive spaces in Renaissance paintings, such as the vault in Masaccio's Trinità and the plaza in Piero della Francesca's Flagellazione. While the vast majority of realist paintings provide but a single view, some provide multiple views, through mirrors depicted within their tableaus. The contemporary American realist Scott Fraser's Three way vanitas is a highly realistic still-life containing three mirrors; each mirror provides a new view of the objects in the tableau. We applied multiple-view reconstruction methods to the direct image and the images reflected by these mirrors to reconstruct the three-dimensional tableau. Our methods estimate virtual viewpoints for each view using the geometric constraints provided by the direct view of the mirror frames, along with the reflected images themselves. Moreover, our methods automatically discover inconsistencies between the different views, including ones that might elude careful scrutiny by eye, for example the fact that the height of the water in the glass differs between the direct view and that in the mirror at the right. We believe our work provides the first application of multiple-view reconstruction to a single painting and will have application to other paintings and questions in the history of art.

Smith, Brandon M.; Stork, David G.; Zhang, Li

2009-01-01

249

Ellipse evolving common reflection point velocity analysis and its application to oil and gas detection  

NASA Astrophysics Data System (ADS)

An ellipse evolving common reflection point (CRP) is an innovative stack method. Under some velocity distribution, we can obtain a real zero-offset section by projecting seismic signals to isochrones along an elliptic trajectory. This paper introduces this method and its velocity analysis. By theoretical model and real seismic data processing, the ellipse evolving CRP velocity analysis more accurately estimates the CRP stack velocity of a complex geology section. The method also more clearly detects an interval velocity anomaly. It is a valuable method of reservoir prediction and oil and gas detection.

Zhou, Qing-Chun; Liu, Huai-Shan; Kondrashkov, V. V.; Li, Guo-Du; Lin, Yi-Hua

2009-03-01

250

Quantitative plasmonic measurements using embedded phase stepping confocal interferometry.  

PubMed

In previous publications [Opt. Express 20, 7388 (2012), Opt. Express 20, 28039 (2012)] we showed how a confocal configuration can form an surface plasmon microscope involving interference between a path involving the generation of surface plasmons and one involving a directly reflected beam. The relative phase of these contributions changes with axial scan position allowing the phase velocity of the surface plasmon to be measured. In this paper we extend the interferometer concept to produce an 'embedded' phase shifting interferometer, where we can control the phase between the reference and surface plasmon beams with a spatial light modulator. We demonstrate that this approach facilitates extraction of the amplitude and phase of the surface plasmon to measure of the phase velocity and the attenuation of the surface plasmons with greatly improved signal to noise compared to previous measurement approaches. We also show that reliable results are obtained over smaller axial scan ranges giving potentially superior lateral resolution. PMID:23670009

Zhang, Bei; Pechprasarn, Suejit; Somekh, Michael G

2013-05-01

251

Endoscopic probe optics for spectrally encoded confocal microscopy  

PubMed Central

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

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

2013-01-01

252

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

253

On reflection symmetry and its application to the Euler-Lagrange equations in fractional mechanics.  

PubMed

We study the properties of fractional differentiation with respect to the reflection symmetry in a finite interval. The representation and integration formulae are derived for symmetric and anti-symmetric fractional derivatives, both of the Riemann-Liouville and Caputo type. The action dependent on the left-sided Caputo derivatives of orders in the range (1,2) is considered and we derive the Euler-Lagrange equations for the symmetric and anti-symmetric part of the trajectory. The procedure is illustrated with an example of the action dependent linearly on fractional velocities. For the obtained Euler-Lagrange system, we discuss its localization resulting from the subsequent symmetrization of the action. PMID:23547223

Klimek, Ma?gorzata

2013-04-01

254

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

NASA Astrophysics Data System (ADS)

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

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

2007-05-01

255

CARISMA: Context-Aware Reflective mIddleware System for Mobile Applications  

Microsoft Academic Search

Mobile devices, such as mobile phones and personal digital assistants, have gained wide-spread popularity. These devices will increasingly be networked, thus enabling the con- struction of distributed applications that have to adapt to changes in context, such as variations in network bandwidth, battery power, connectivity, reachability of services and hosts, and so on. In this paper we describe CARISMA, a

Licia Capra; Wolfgang Emmerich; Cecilia Mascolo

2003-01-01

256

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

Technology Transfer Automated Retrieval System (TEKTRAN)

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

257

A Novel Ring Shaped Photodiode for Reflectance Pulse Oximetry in Wireless Applications  

Microsoft Academic Search

We present a pulse oximeter for use in home-care applications in a sticking patch with integrated electronics. The core in the pulse oximeter is a large ring shaped backside silicon pn photodiode placed around a Ledtronics dual LED with wavelengths of 660 nm and 940 nm. The concentric photodiode gives optimal gathering of light and thereby enabling lower LED drive

S. Duun; R. G. Haahr; K. Birkelund; P. Raahauge; P. Petersen; H. Dam; L. Noergaard; E. V. Thomsen

2007-01-01

258

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

Microsoft Academic Search

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

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

1999-01-01

259

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

260

Use of UV-excitation for confocal fluorescence microscopy in a conventional beam-scanning instrument  

NASA Astrophysics Data System (ADS)

By making only minor modifications, we have adapted a conventional confocal scanning laser microscope for the recording of UV-excited fluorescence. An external argon ion laser provides the wavelengths 334, 351, and 364 nm for specimen illumination. In addition to substituting some optical components to obtain improved transmission and reflection properties in the UV, we have also adjusted the ray-path to compensate for the severe chromatic aberration of most conventional microscope objectives in the UV. We have also tested mirror objectives, which are inherently free from chromatic aberrations. However, since these objectives are not of the immersion-type, and furthermore have rather low numerical apertures, they are of limited value in biomedical applications. Using the modified instrument, we have recorded specimens labeled with AMCA and Fluoro-Gold. At present the instrument is capable of recording optical sections with a thickness of 1.5 micrometers when using an oil-immersion objective with a numerical aperture of 1.25.

Carlsson, Kjell; Mossberg, Karin; Helm, Paul J.; Philip, Johan

1992-06-01

261

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

262

MEMS-Based Dual Axes Confocal Microendoscopy  

PubMed Central

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

Piyawattanametha, Wibool; Wang, Thomas D.

2011-01-01

263

SOME ASPECTS OF CHROMATIC CONFOCAL SPECTRAL INTERFEROMETRY  

Microsoft Academic Search

In this paper, we report on the recent development of a novel low coherence interferometry technique for the purpose of 3D-topography measurements. It combines the well established techniques of spectral-interferometry (SI) and chromatic-confocal microscopy (CCM). It allows for the detection of an object's depth position, without the necessity of a mechanical axial-scan, and the measurement is performed in a so-called

Klaus Körner; Evangelos Papastathopoulos; Wolfgang Osten

264

Chromatic confocal spectral interferometry with wavelet analysis  

Microsoft Academic Search

In the present paper, we address a hybrid technique which combines the method of spectral interferometry with chromatic confocal microscopy. On the basis of some proof-of-principle experiments, it is shown that with this new concept, the axial detection range of the sensor is decoupled from the limited depth-of-focus of the employed microscope objective, and a high numerical aperture objective can

E. Papastathopoulos; K. Körner; W. Osten

2006-01-01

265

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

266

Visualization of confocal microscopic biomolecular data  

NASA Astrophysics Data System (ADS)

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

Liu, Zhanping; Moorhead, Robert J., II

2005-04-01

267

NIR reflectance hyperspectral microscopy for planetary science: Application to the MicrOmega instrument  

NASA Astrophysics Data System (ADS)

Hyperspectral microscopy, by its capability to characterize in situ the composition of samples at their grain size scale and the coupling between the different phases, complements efficiently the remote sensing hyperspectral imagers. Objectives, rationale and limits of hyperspectral microscopy in the planetary science field are summarized in this paper. A new concept of NIR reflectance hyperspectral microscope, MicrOmega is presented and results obtained both with a representative breadboard and a first version of the MicrOmega instrument, recently integrated on the Phobos Grunt lander, are discussed. Results show that we are now able to build instruments capable of analyzing samples at the grain scale, typically a few tens of microns per pixel, within volume, weight, power and time budgets compatible with typical rover's constraints. We demonstrate the ability of such instruments to characterize samples, identify their major and minor constituents, some non-detectable from orbit, and their spatial coupling. Instruments based on the MicrOmega concept have been selected as part of the Hayabusa-2 Mascot Lander that will study in situ a C-class asteroid, as well as of the ExoMars rover that would characterize Mars potential past and present habitability. In both cases, these in situ analyses should provide essential data to improve our understanding of the history of the object explored.

Pilorget, C.; Bibring, J.-P.

2013-02-01

268

Enhanced confocal microscopy and ophthalmoscopy with polarization imaging  

NASA Astrophysics Data System (ADS)

We previously developed a Mueller matrix formalism to improve confocal imaging in microscopes and ophthalmoscopes. Here we describe a procedure simplified by firstly introducing a generator of polarization states in the illumination pathway of a confocal scanning laser microscope and secondly computing just four elements of the Mueller matrix of any sample and instrument combination. Using a subset of Mueller matrix elements, the best images are reconstructed. The method was tested for samples with differing properties (specular, diffuse and partially depolarizing). Images were also studied of features at the rear of the eye. The best images obtained with this technique were compared to the original images and those obtained from frame averaging. Images corresponding to non-polarized incident light were also computed. For all cases, the best reconstructed images were of better quality than both the original and frame-averaged images. The best reconstructed images also showed an improvement compared with the images corresponding to non polarized light. This methodology will have broad application in biomedical imaging.

Campbell, Melanie C. W.; Bueno, Juan M.; Cookson, Christopher J.; Liang, Qingyuan; Kisilak, Marsha L.; Hunter, Jennifer J.

2005-09-01

269

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

NASA Astrophysics Data System (ADS)

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

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

2010-12-01

270

Correcting spaceborne reflectivity measurements for application in solar ultraviolet radiation levels calculations at ground level  

NASA Astrophysics Data System (ADS)

The Lambertian Equivalent Reflection (LER) produced by satellite-carried instruments is used to determine cloud effects on ground level UltraViolet (UV) radiation. The focus is on data use from consecutive operating instruments: the Total Ozone Mapping Spectrometers (TOMS) flown on Nimbus 7 from 1979 to 1992, TOMS on Earth Probe from 1996 to 2005, and the Ozone Monitoring Instrument (OMI) flown on Aura since 2004. The LER data produced by TOMS on Earth Probe is only included until 2002. The possibility to use the Radiative Cloud Fraction (RCF)-product of OMI is also investigated. A comparison is made with cloud effects inferred from ground-based pyranometer measurements at over 83 World Radiation Data Centre stations. Modelled UV irradiances utilizing LER data are compared with measurements of UV irradiances at eight European low elevation stations. The LER data set of the two TOMS instruments shows a consistent agreement, and the required corrections are of low percentage i.e. 2-3%. In contrast, the LER data of OMI requires correction of 7-10%, and a solar angle dependency therein is more pronounced. These corrections were inferred from a comparison with pyranometer data, and tested using the UV measurements. The RCF product of OMI requires a large correction but can then be implemented as a cloud effect proxy. However, a major drawback of RCF is the large number of clipped data, i.e. 18%, and results are not better than those obtained with the corrected LER product of OMI. The average reduction of UV radiation due to clouds for all sites together indicate a small trend: a diminishing cloudiness, in line with ground-based UV observations. Uncorrected implementation of LER would have indicated the opposite. An optimal field of view of 1.25° was established for LER data to calculate UV radiations levels. The corresponding area can be traversed within 5-7 h at the average wind speeds found for the West European continent.

den Outer, P. N.; van Dijk, A.; Slaper, H.; Lindfors, A. V.; de Backer, H.; Bais, A. F.; Feister, U.; Koskela, T.; Josefsson, W.

2012-01-01

271

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

NASA Astrophysics Data System (ADS)

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

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

2012-11-01

272

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

NASA Astrophysics Data System (ADS)

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

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

2011-02-01

273

A reflective microwave switch made of Tl-Ca-Ba-Cu-O for signal control applications  

NASA Astrophysics Data System (ADS)

A thermal thin-film high-temperature superconductor (HTS) switch that is easily inserted into high-performance HTS transmission lines is presented. A microwave switch in Tl-Ca-Ba-Cu-O has been developed based on driving a small bridge, embedded in a transmission line, normal via current in an external control line. In the on-state, insertion loss was less than 1 dB over the tested range of 0.5-8.5 GHz. Isolation in the off-state exceeded 30 dB over this frequency range. Response times are on the order of a microsecond, adequate for many microwave/millimeter-wave applications such as switched phase shifters.

Martens, J. S.; Hietala, V. M.; Zipperian, T. E.; Ginley, D. S.; Tigges, C. P.; Hohenwarter, G. K. G.

1991-10-01

274

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

275

Reflective Superinsulation Materials.  

National Technical Information Service (NTIS)

Reflective superinsulation films are gradually being adapted for use in civilian thermal products. A wide range of their applications in emergency equipment and lightweight clothing is described. (Author)

1975-01-01

276

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

277

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

NASA Astrophysics Data System (ADS)

A quick and reliable analytical method for the quantitative assessment of cefixime in orally administered pharmaceutical formulations is developed by using diamond cell attenuated total reflectance (ATR) Fourier transform infrared (FT-IR) spectroscopy as an easy procedure for quality control laboratories. The standards for calibration were prepared in aqueous medium ranging from 350 to 6000 mg/kg. The calibration model was developed based on partial least square (PLS) using finger print region of FT-IR spectrum in the range from 1485 to 887 cm-1. Excellent coefficient of determination (R2) was achieved as high as 0.99976 with root mean square error of 44.8 for calibration. The application of diamond cell (smart accessory) ATR FT-IR proves a reliable determination of cefixime in pharmaceutical formulations to assess the quality of the final product.

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

2013-11-01

278

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

NASA Astrophysics Data System (ADS)

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

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

2012-07-01

279

Confocal imaging of benign and malignant proliferative skin lesions in vivo  

NASA Astrophysics Data System (ADS)

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

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

1999-06-01

280

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

NASA Astrophysics Data System (ADS)

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

Vongsaard, Jearanai

281

Signal and noise modeling in confocal laser scanning fluorescence microscopy.  

PubMed

Fluorescence confocal laser scanning microscopy (CLSM) has revolutionized imaging of subcellular structures in biomedical research by enabling the acquisition of 3D time-series of fluorescently-tagged proteins in living cells, hence forming the basis for an automated quantification of their morphological and dynamic characteristics. Due to the inherently weak fluorescence, CLSM images exhibit a low SNR. We present a novel model for the transfer of signal and noise in CLSM that is both theoretically sound as well as corroborated by a rigorous analysis of the pixel intensity statistics via measurement of the 3D noise power spectra, signal-dependence and distribution. Our model provides a better fit to the data than previously proposed models. Further, it forms the basis for (i) the simulation of the CLSM imaging process indispensable for the quantitative evaluation of CLSM image analysis algorithms, (ii) the application of Poisson denoising algorithms and (iii) the reconstruction of the fluorescence signal. PMID:23285574

Herberich, Gerlind; Windoffer, Reinhard; Leube, Rudolf E; Aach, Til

2012-01-01

282

Confocal Brillouin microscopy for three-dimensional mechanical imaging  

NASA Astrophysics Data System (ADS)

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

Scarcelli, Giuliano; Yun, Seok Hyun

2008-01-01

283

A new paradigm in dermatopharmacokinetics - Confocal Raman spectroscopy.  

PubMed

Confocal Raman spectroscopy (CRS) is a novel approach which has been used to determine stratum corneum thickness and to profile endogenous skin components. However, the utility of this technique for probing drug disposition in vivo has not been explored to date. In this paper we report the use of CRS to investigate the fate of ibuprofen after application from simple formulations which were previously investigated using the tape-stripping approach. Ibuprofen was prepared in propylene glycol (PG) and propylene glycol/water (PG/H2O) solutions. The formulations were then applied to the volar aspect of the forearm of human volunteers. The results confirmed that ibuprofen distribution profiles in the stratum corneum were comparable to previously published data from tape stripping experiments. We propose CRS as a non-invasive method for dermatopharmacokinetic evaluation of topical pharmaceutical formulations. PMID:23357254

Mateus, R; Abdalghafor, H; Oliveira, G; Hadgraft, J; Lane, M E

2013-01-26

284

Quantitative single-molecule imaging by confocal laser scanning microscopy  

PubMed Central

A new approach to quantitative single-molecule imaging by confocal laser scanning microscopy (CLSM) is presented. It relies on fluorescence intensity distribution to analyze the molecular occurrence statistics captured by digital imaging and enables direct determination of the number of fluorescent molecules and their diffusion rates without resorting to temporal or spatial autocorrelation analyses. Digital images of fluorescent molecules were recorded by using fast scanning and avalanche photodiode detectors. In this way the signal-to-background ratio was significantly improved, enabling direct quantitative imaging by CLSM. The potential of the proposed approach is demonstrated by using standard solutions of fluorescent dyes, fluorescently labeled DNA molecules, quantum dots, and the Enhanced Green Fluorescent Protein in solution and in live cells. The method was verified by using fluorescence correlation spectroscopy. The relevance for biological applications, in particular, for live cell imaging, is discussed.

Vukojevic, Vladana; Heidkamp, Marcus; Ming, Yu; Johansson, Bjorn; Terenius, Lars; Rigler, Rudolf

2008-01-01

285

Automated biofilm morphology quantification from confocal laser scanning microscopy imaging.  

PubMed

In spite of the immediate visual appeal of confocal laser scanning microscopy images, the extraction of accurate reconstitutions of biofilm morphology requires a lengthy and computational intensive succession of processing steps. However, once performed, it provides ample reward by enabling the quantitative study of biofilm structure. A software suite of image processing tools for full automation of biofilm morphology quantification was developed by integrating preprocessing, segmentation and morphology quantification operations. This software toolbox was implemented in a web server and a user friendly interface was developed to facilitate image submission, storage and sharing, its access being unrestricted for scientific applications. The image bioinformatics tool which results from the integration of the processing operations can be accessed at http://www.itqb.unl.pt:111/clsmip/. Its use is described in this paper and is illustrated with an example of processing of experimental data describing the growth of a mixed species dentrifying biofilm. PMID:12701903

Xavier, J B; White, D C; Almeida, J S

2003-01-01

286

Confocal micro-optical distance sensor: realization and results  

NASA Astrophysics Data System (ADS)

In this paper, the realization and characterization of a microoptical sensor using the chromatic confocal principle is presented. The sensor head is designed for distance gauging applications in high aspect ratio cavities with a diameter of about 2 mm. The first part of this paper focuses on the design and fabrication process of the hybrid optical benches, which combines refractive and diffractive micro optical components. Very tight tolerances of the optical path are required for the functionality of the sensor. Therefore the alignment structures and mounts between the different optical elements are produced from PMMA using deep X-ray lithography, the first step of the LIGA process. In the second part of this paper the characterization of first prototypes using different light sources are described and results presented.

Lucke, Peter; Last, Arndt; Mohr, Jurgen; Ruprecht, Aiko K.; Pruss, Christof; Tiziani, Hans J.; Osten, Wolfgang; Lehmann, Peter; Schonfelder, Sven

2005-06-01

287

Integrated Photoacoustic and Fluorescence Confocal Microscopy  

PubMed Central

We have developed a dual-modality imaging system by integrating optical-resolution photoacoustic microscopy and fluorescence confocal microscopy to provide optical absorption and fluorescence contrasts simultaneously. By sharing the same laser source and objective lens, intrinsically registered photoacoustic and fluorescence images are acquired in a single scan. The micrometer resolution allows imaging of both blood and lymphatic vessels down to the capillary level. Simultaneous photoacoustic angiography and fluorescence lymphangiography were demonstrated, presenting more information about tumor angiogenesis, vasculature, and microenvironments in vivo.

Wang, Yu; Maslov, Konstantin; Kim, Chulhong; Hu, Song

2010-01-01

288

Handheld confocal Raman microspectrometer for in-vivo skin cancer measurement  

NASA Astrophysics Data System (ADS)

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

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

2004-07-01

289

Coin-shaped epithelial lesions following an acute attack of erythema multiforme minor with confocal microscopy findings.  

PubMed

We report an interesting ocular finding of bilateral multiple coin-shaped epithelial lesions along with the confocal microscopy findings in a patient following an acute attack of erythema multiforme (EM) minor. A 30-year-old male presented with a history of watering and irritation in both eyes of three days duration. He was diagnosed to have EM minor and was on oral acyclovir. Slit-lamp examination revealed multiple coin-shaped epithelial lesions. Confocal microscopy showed a corresponding conglomerate of hyper-reflective epithelial lesions. The corneal lesions resolved over six weeks with oral steroids and acyclovir. An immunological mechanism is suspected. PMID:20029149

Babu, Kalpana; Murthy, Vinay R; Akki, Veeresh P; Prabhakaran, Venkatesh C; Murthy, K R

290

Agile optical confocal microscopy instrument architectures for high flexibility imaging  

NASA Astrophysics Data System (ADS)

Ideally, a no-moving parts fast and agile scanning confocal microscope system is required that can produce true real-time 3-D scans with precision and repeatability. In this paper, such agile optical confocal microsopy designs are proposed that enable high speed precise non-invasive 3-D imaging. These compact confocal microscopes can provide real-time pin-point focussed imaging to enable confocal slices in-vivo, thus greatly reducing motion artifacts. These microscopes can be modified into interferometric microscopes for phase contrast imaging. The proposed microscopes can also greatly improve confocal fluorescence imaging as needed for cancer detection. An ultracompact confocal probe tip connected to a single ultra-thin fiber is another design option allowing flexibility for usage in tight cavities.

Riza, Nabeel A.; Bokhari, Amana

2004-07-01

291

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

Microsoft Academic Search

Chromatic confocal microscopy (CCM) and spectral interferometry (SI) are established and robust sensor principles. CCM is a focus-based measurement principle, whose lateral and axial resolutions depend on the sensor's numerical aperture (NA), while the measurement range is given by the spectral bandwidth and the chromatic dispersion in the axial direction. Although CCM is a robust principle, its accuracy can be

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

2012-01-01

292

Chromatic confocal detection for high-speed microtopography measurements  

Microsoft Academic Search

The chromatic confocal approach enables the parallelization of the complete depth-scan of confocal topography measurements. Therefore, mechanical movement can be reduced or completely avoided and the measurement times shortened. Chromatic confocal point sensors are already commercially available but they need lateral scanning in x- and y-direction in order to measure surface topographies. We achieved a further parallelization in the x-direction

Aiko K. Ruprecht; Klaus Koerner; Tobias F. Wiesendanger; Hans J. Tiziani; Wolfgang Osten

2004-01-01

293

Confocal multipoint multiphoton excitation microscope with microlens and pinhole arrays  

Microsoft Academic Search

We show the first experimental results with a confocal multipoint multiphoton excitation microscope, where a confocal pinhole-array is used to enhance the three-dimensional spatial resolution and the depth-penetration property. Comparisons of images obtained with and without the pinhole-array show the enhancement of the contrast of fluorescence images and the sharper depth-discrimination property in the confocal system. In the experimental result,

Katsumasa Fujita; Osamu Nakamura; Tomoyuki Kaneko; Masahito Oyamada; Tetsuro Takamatsu; Satoshi Kawata

2000-01-01

294

Multispectral confocal microendoscope for in-vivo imaging  

Microsoft Academic Search

The concept of in-vivo multi-spectral confocal microscopy is introduced. A slit-scanning multi-spectral confocal microendoscope (MCME) was built to demonstrate the technique. The MCME employs a flexible fiber-optic catheter coupled to a custom built slit-scan confocal microscope fitted with a custom built imaging spectrometer. The catheter consists of a fiber-optic imaging bundle linked to a miniature objective and focus assembly. The

Andrew Robert Rouse

2004-01-01

295

Identification of nodal tissue in the living heart using rapid scanning fiber-optics confocal microscopy and extracellular fluorophores.  

PubMed

Background- Risks associated with pediatric reconstructive heart surgery include injury of the sinoatrial node (SAN) and atrioventricular node (AVN), requiring cardiac rhythm management using implantable pacemakers. These injuries are the result of difficulties in identifying nodal tissues intraoperatively. Here we describe an approach based on confocal microscopy and extracellular fluorophores to quantify tissue microstructure and identify nodal tissue. Methods and Results- Using conventional 3-dimensional confocal microscopy we investigated the microstructural arrangement of SAN, AVN, and atrial working myocardium (AWM) in fixed rat heart. AWM exhibited a regular striated arrangement of the extracellular space. In contrast, SAN and AVN had an irregular, reticulated arrangement. AWM, SAN, and AVN tissues were beneath a thin surface layer of tissue that did not obstruct confocal microscopic imaging. Subsequently, we imaged tissues in living rat hearts with real-time fiber-optics confocal microscopy. Fiber-optics confocal microscopy images resembled images acquired with conventional confocal microscopy. We investigated spatial regularity of tissue microstructure from Fourier analysis and second-order image moments. Fourier analysis of fiber-optics confocal microscopy images showed that the spatial regularity of AWM was greater than that of nodal tissues (37.5±5.0% versus 24.3±3.9% for SAN and 23.8±3.7% for AVN; P<0.05). Similar differences of spatial regularities were revealed from second-order image moments (50.0±7.3% for AWM versus 29.3±6.7% for SAN and 27.3±5.5% for AVN; P<0.05). Conclusions- The study demonstrates feasibility of identifying nodal tissue in living heart using extracellular fluorophores and fiber-optics confocal microscopy. Application of the approach in pediatric reconstructive heart surgery may reduce risks of injuring nodal tissues. PMID:23811748

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

2013-06-27

296

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

NASA Astrophysics Data System (ADS)

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

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

1995-05-01

297

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.

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

2012-01-01

298

8.G Reflecting reflections  

NSDL National Science Digital Library

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

299

Accurate Sizing of Nanoparticles Using Confocal Correlation Spectroscopy  

PubMed Central

The ability to size accurately low concentrations of nanoscale particles in small volumes is useful for a broad range of disciplines. Here, we characterize confocal correlation spectroscopy (CCS), which is capable of measuring sizes of both fluorescent and non-fluorescent particles, such as quantum dots, gold colloids, latex spheres, and fluorescent beads. We measured accurately particles ranging in diameter from 11 nm to 300 nm, a size range that had been difficult to probe, owing to a phenomenon coined biased diffusion that causes diffusion times, or particle size, to deviate as a function of laser power. At low powers, artifacts mimicking biased diffusion are caused by saturation of the detector, which is especially problematic when probing highly fluorescent or highly scattering nanoparticles. At higher powers (>1 mW), however, autocorrelation curves in both resonant and non-resonant conditions show a structure indicative of an increased contribution from longer correlation times coupled with a decrease in shorter correlation times. We propose this change in the autocorrelation curve is due to partial trapping of the particles as they transit the probe volume. Furthermore, we found only a slight difference in the effect of biased diffusion when comparing resonant and non-resonant conditions. Simulations suggest the depth of trapping potential necessary for biased diffusion is >1 kBT. Overcoming artifacts from detector saturation and biased diffusion, confocal correlation spectroscopy is particularly advantageous due to its ability to size particles in small volumes characteristic of microfluidic channels and aqueous microdroplets. We believe the method will find increasing use in a wide range of applications in measuring nanoparticles and macromolecular systems.

Kuyper, Christopher L.; Fujimoto, Bryant S.; Zhao, Yiqiong; Schiro, Perry G.; Chiu, Daniel T.

2008-01-01

300

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

301

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

302

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

PubMed

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

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

2013-09-01

303

Visualizing Cochlear Mechanics Using Confocal Microscopy  

NASA Astrophysics Data System (ADS)

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

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

2003-02-01

304

Opto-mechanical analysis for confocal laser scanning microscopes  

Microsoft Academic Search

The confocal imaging has become one of the most widely applied microscopic techniques in various fields, such as biotechnology, automation engineering, optical engineering, solid-state physics, metallurgy, integrated circuit inspection, etc. Confocal laser scanning microscopy (CLSM) is primarily based on the use of apertures in the detection path to provide the acquired three-dimensional images with satisfactory contrast and resolution. The major

Gao-Wei Chang; Ming-Jenq Twu; Yu-Hsuan Lin; Chia-Cheng Liao; Hung-Zen Kuo

2005-01-01

305

Spatial Resolution in Photon-Limited Confocal Optical Microscopy  

Microsoft Academic Search

The behavior of photon-limited light is discussed in reference to its use in confocal microscopy. A ray-tracing based simulation of photons passing through a confocal optical imaging system is performed with the photon propagation determined by the photon distribution function at the photodetector. The formation of the image of a point source is considered with regard to how well the

Giovanni Tapang; Caesar Saloma

2001-01-01

306

Interfacial colloidal sedimentation equilibrium. I. Intensity based confocal microscopy  

Microsoft Academic Search

This paper reports confocal microscopy measurements of inhomogeneous colloidal sedimentation equilibrium profiles near planar wall surfaces for conditions when colloid dimensions are comparable to the characteristic gravitational length scale. The intensity based confocal method developed in this work enables real-space measurements of one-dimensional density profiles of Brownian colloids without identifying many single colloid centers in large imaging volumes. Measured sedimentation

Richard E. Beckham; Michael A. Bevan

2007-01-01

307

Evaluation and purchase of confocal microscopes: Numerous factors to consider  

EPA Science Inventory

The purchase of a confocal microscope can be a complex and difficult decision for an individual scientist, group or evaluation committee. This is true even for scientists that have used confocal technology for many years. The task of reaching the optimal decision becomes almost i...

308

Chromatic confocal spectral interferometry for technical surface characterization  

Microsoft Academic Search

Chromatic confocal spectral interferometry (CCSI) is a hybrid method for fast topography measurement, which combines the advantages of the interferometric gain and accuracy with the robustness of confocal microscopy. The CCSI-principle provides a single shot measurement of depth while offering a higher lateral resolution than commonly used spectral interferometers. This contribution is focused on the modeling and simulation of a

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

2009-01-01

309

X-ray reflectivity investigation of interlayer at interfaces of multilayer structures: application to Mo\\/Si multilayers  

Microsoft Academic Search

We report the effect of interlayer on multilayer X-ray reflectivity (XRR) profile using simulations at 8·047 keV (CuK?) energy. We distinguished the effect of interfacial roughness and in-depth interlayer on reflectivity profile. The interfacial roughness reduces the intensity of individual peak while the in-depth inter- layer redistributed the reflectivity profile. We are able to discern the asymmetry in interlayer thickness

M NAYAK; G S LODHA; R V NANDEDKAR

2006-01-01

310

Surface Morphology and Optical Reflection of Thermally Evaporated Thin Film Al-Doped Silicon on Plastic Substrates for Solar Cells Applications  

Microsoft Academic Search

In this paper, authors have investigated the surface morphology and optical reflection of thermally evaporated thin film silicon (Si) on plastic substrates (polyethylene terephthalate, PET) at different aluminium (Al) composition (denoted by Al\\/Si ratio) for applications in solar cells. Results show that the thermally evaporated p-type Si possesses fairly smooth surfaces as characterised by atomic force microscopy (AFM) images. The

Mohd Zamir Pakhuruddin; Kamarulazizi Ibrahim; Mohammed Khaleel Mohammed Ali; Azlan Abdul Aziz

2011-01-01

311

Surface Morphology and Optical Reflection of Thermally Evaporated Thin Film Al-Doped Silicon on Plastic Substrates for Solar Cells Applications  

Microsoft Academic Search

In this paper, authors have investigated the surface morphology and optical reflection of thermally evaporated thin film silicon (Si) on plastic substrates (polyethylene terephthalate, PET) at different aluminium (Al) composition (denoted by Al?Si ratio) for applications in solar cells. Results show that the thermally evaporated p-type Si possesses fairly smooth surfaces as characterised by atomic force microscopy (AFM) images. The

Mohd Zamir Pakhuruddin; Kamarulazizi Ibrahim; Mohammed Khaleel Mohammed Ali; Azlan Abdul Aziz

2011-01-01

312

Physically-Based Models for the Reflection, Transmission and Subsurface Scattering of Light by Smooth and Rough Surfaces, with Applications to Realistic Image Synthesis  

Microsoft Academic Search

This thesis studies light scattering processes off rough surfaces. Analytic models for reflection, transmission and subsurface scattering of light are developed. The results are applicable to realistic image generation in computer graphics. The investigation focuses on the basic issue of how light is scattered locally by general surfaces which are neither diffuse nor specular; Physical optics is employed to account

Xiao Dong He

1993-01-01

313

Confocal Raman Microscopy on in-situ Structural Evolution of Polyolefin Blends  

NASA Astrophysics Data System (ADS)

Polyolefins account for more than half of world-wide consumption of plastic materials, and are typically blended with fillers and other types of polymers in applications. In particular, understanding the miscibility and phase behaviors of polyolefin blends is important for the advancement of a wide array of new applications in medicine, packaging, and other fields. We have used Confocal Raman Microscopy to take the advantages of it capability to locally probe the transformation of physical states in polymeric materials and to characterize morphology of polyolefin blends in-situ for lateral and in-depth imaging with a micron-scale spatial resolution. Upon distinct changes of Raman spectra associated with the melting of semicrystaline polyolefins, we report the in-situ morphological changes upon heating and cooling of polyethylene-polyethylene and polypropylene-polyethylene using confocal Raman microscopy with heating stage.

Chang, Wansoo; Jeon, Byungho; Lee, Jong-Won; Ryu, Chang Y.

2011-03-01

314

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

NASA Astrophysics Data System (ADS)

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

Bleibinhaus, F.; Gebrande, H.

2003-04-01

315

Total internal reflection fluorescence (TIRF) microscopy of Chlamydomonas flagella.  

PubMed

The eukaryotic flagellum is host to a variety of dynamic behaviors, including flagellar beating, the motility of glycoproteins in the flagellar membrane, and intraflagellar transport (IFT), the bidirectional traffic of protein particles between the flagellar base and tip. IFT is of particular interest, as it plays integral roles in flagellar length control, cell signaling, development, and human disease. However, our ability to understand dynamic flagellar processes such as IFT is limited in large part by the fidelity with which we can image these behaviors in living cells. This chapter introduces the application of total internal reflection fluorescence (TIRF) microscopy to visualize the flagella of Chlamydomonas reinhardtii. The advantages and challenges of TIRF are discussed in comparison to confocal and differential interference contrast techniques. This chapter also reviews current IFT insights gleaned from TIRF microscopy of Chlamydomonas and provides an outlook on the future of the technique, with particular emphasis on combining TIRF with other emerging imaging technologies. PMID:20409817

Engel, Benjamin D; Lechtreck, Karl-Ferdinand; Sakai, Tsuyoshi; Ikebe, Mitsuo; Witman, George B; Marshall, Wallace F

2009-12-04

316

Total Internal Reflection Fluorescence (TIRF) Microscopy of Chlamydomonas Flagella  

PubMed Central

The eukaryotic flagellum is host to a variety of dynamic behaviors, including flagellar beating, the motility of glycoproteins in the flagellar membrane, and intraflagellar transport (IFT), the bidirectional traffic of protein particles between the flagellar base and tip. IFT is of particular interest, as it plays integral roles in flagellar length control, cell signaling, development, and human disease. However, our ability to understand dynamic flagellar processes such as IFT is limited in large part by the fidelity with which we can image these behaviors in living cells. This chapter introduces the application of total internal reflection fluorescence (TIRF) microscopy to visualizing the flagella of Chlamydomonas reinhardtii. The advantages and challenges of TIRF are discussed in comparison to confocal and differential interference contrast (DIC) techniques. This chapter also reviews current IFT insights gleaned from TIRF microscopy of Chlamydomonas and provides an outlook on the future of the technique, with particular emphasis on combining TIRF with other emerging imaging technologies.

Engel, Benjamin D.; Lechtreck, Karl-Ferdinand; Sakai, Tsuyoshi; Ikebe, Mitsuo; Witman, George B.; Marshall, Wallace F.

2013-01-01

317

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

NASA Astrophysics Data System (ADS)

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 algorithm to improve the ability to reconstruct the in-focus plane when the out-of-focus light is much greater in magnitude. We characterize the dependencies of this algorithm on phase step error, random noise and backscattered out-of-focus contributions. Second, we utilize a molecular-specific reflectance contrast agent based on gold nanoparticles to label disease-related biomarkers and increase the signal and signal-to-noise ratio (SNR) in structured illumination microscopy of biological tissue. Imaging results for multi-layer epithelial cell phantoms with optical properties characteristic of normal and cancerous tissue labeled with nanoparticles targeted against the epidermal growth factor receptor (EGFR) are presented. Structured illumination images reconstructed with the sine approximation algorithm compare favorably to those obtained with a standard confocal microscope; this new technique can be implemented in simple and small imaging platforms for future clinical studies.

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

2004-08-01

318

Cylindrical Illumination Confocal Spectroscopy: Rectifying the Limitations of Confocal Single Molecule Spectroscopy through One-Dimensional Beam Shaping  

Microsoft Academic Search

Cylindrical illumination confocal spectroscopy (CICS) is a new implementation of single molecule detection that can be generically incorporated into any microfluidic system and allows highly quantitative and accurate analysis of single fluorescent molecules. Through theoretical modeling of confocal optics and Monte Carlo simulations, one-dimensional beam shaping is used to create a highly uniform sheet-like observation volume that enables the detection

Kelvin J. Liu; Tza-Huei Wang

2008-01-01

319

Classification of Inflammation Activity in Ulcerative Colitis by Confocal Laser Endomicroscopy  

Microsoft Academic Search

OBJECTIVES:The assessment of inflammation activity in ulcerative colitis (UC) includes endoscopy and histology. Confocal laser endomicroscopy (CLE) combines real-time endoscopy and histology. This study was aimed at evaluating the application of CLE in the assessment of inflammation activity in UC.METHODS:In total, 73 consecutive patients with UC who visited Qilu Hospital for colonoscopy surveillance underwent CLE. Inflammation activity was first assessed

Chang-Qing Li; Xiang-Jun Xie; Tao Yu; Xiao-Meng Gu; Xiu-Li Zuo; Cheng-Jun Zhou; Wei-Qing Huang; Hua Chen; Yan-Qing Li

2010-01-01

320

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

NASA Astrophysics Data System (ADS)

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

Sun, Tianxi; MacDonald, C. A.

2013-02-01

321

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

PubMed

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

Sun, Tianxi; Macdonald, C A

2013-02-04

322

Formation of self-assembled large droplet-epitaxial GaAs islands for the application to reduced reflection  

NASA Astrophysics Data System (ADS)

The structural and reflectance properties of large gallium (Ga) droplets and GaAs islands grown by droplet epitaxy (DE) were presented. The reflectance results of self-assembled large GaAs islands by DE suggest the possibility of a novel method for antireflective coating. The diameter, height, density, and aspect ratio of large Ga droplets were investigated up to the scale of optical size. After GaAs island growth, the reflectance of s-polarization at 70° on in-situ measurement was reduced up to approximately 2%-20% in the wavelength range of 350-900 nm. For large GaAs islands, reduction of reflectance for s-, p-polarization at 20°-80° and reduction of reflectance at normal incidence was presented. This result shows that a layer of self-assembled large GaAs islands by DE can be a good candidate for an antireflector for high-quality optoelectronic devices.

Lee, E. H.; Song, J. D.; Yoon, J. J.; Bae, M. H.; Han, I. K.; Choi, W. J.; Chang, S. K.; Kim, Y. D.; Kim, J. S.

2013-04-01

323

Reflectance spectroscopy in the visible and near-infrared (0.35 2.55 ?m): Applications in carbonate petrology  

NASA Astrophysics Data System (ADS)

Reflectance spectroscopy in the visible and near-infrared (0.35 to 2.55 ?m) offers a rapid, inexpensive, nondestructive tool for determining the mineralogy and for investigating the minor-element chemistry of the hard-to-discriminate carbonate minerals, and can, in one step, provide information previously obtainable only by the combined application of two or more analytical techniques. When light interacts with a mineral, certain wavelengths are preferentially absorbed. The positions and widths of absorptions due to vibrations of the carbonate radical, and the positions and shapes of absorptions due to transition metal cations, if present, can be used to determine mineralogy. Relative intensities of absorptions due to transition metal cations can be used to determine concentration of these cations. Because absorptions due to Fe2+ and Mn2+ occur in different regions of the spectrum, the presence of one cation does not interfere with analysis for the other. Detection limits for Mn2+ are about 0.1 wt% Mn and for Fe2+ are about 0.01 wt% Fe. This technique is also very sensitive to the presence of water and indicates that aqueous fluid inclusions are nearly ubiquitous in carbonate minerals and rocks. Spectra indicate that inclusions are particularly abundant in skeletal carbonates and that the quantity of inclusions in skeletal material varies from one type of organism to another. Spectra indicate that inclusions are lost during diagenesis of skeletal material, providing a new criterion for diagenetic studies. *Present address: Geology Department, Rensselaer Polytechnic Institute, Troy, New York 12181

Gaffey, Susan J.

1985-04-01

324

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.

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

2012-01-01

325

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

326

Axial super resolution topography of focal adhesion by confocal microscopy.  

PubMed

The protein organization within focal adhesions has been studied by state-of-the-art super resolution methods because of its thin structure, well below diffraction limit. However, to achieve high axial resolution, most of the current approaches rely on either sophisticated optics or diligent sample preparation, limiting their application. In this report we present a phasor-based method that can be applied to fluorescent samples to determine the precise axial position of proteins using a conventional confocal microscope. We demonstrate that with about 4,000 photon counts collected along a z-scan, axial localization precision close to 10 nm is achievable. We show that, with within 10 nm, the axial location of paxillin, FAK, and talin is similar at focal adhesion sites, while F-actin shows a sharp increase in height towards the cell center. We further demonstrated the live imaging capability of this method. With the advantage of simple data acquisition and no special instrument requirement, this approach could have wide dissemination and application potentials. Microsc. Res. Tech., 76:1070-1078, 2013. © 2013 Wiley Periodicals, Inc. PMID:23897846

Chiu, Chi-Li; Gratton, Enrico

2013-07-29

327

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.

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

328

A prototype two-detector confocal microscope for in vivo corneal imaging.  

PubMed

Confocal microscopy through-focusing (CMTF) of the cornea produces a three-dimensional (3-D) display of corneal structure and intensity profiles that allow objective measurements of corneal sublayer thickness and relative assessment backscattering of light. In this study, a prototype confocal instrument was evaluated in which a photon counting photomultiplier tube (PMT) detector was added to provide faster and more quantitative measurements, while still maintaining the imaging capability of the microscope. To acquire images and measure backscattered light simultaneously, an uncoated pellicle beam splitter was incorporated into the light path of the confocal microscope. This beam splitter reflects 8% of the confocal signal to the PMT. The CMTF scans were performed on four rabbits using the prototype instrument. Corneal images and 3-D reconstructions acquired with and without the beam splitter in the light path appeared identical. Both the camera and PMT CMTF curves had easily identifiable peaks corresponding to the epithelium, basal lamina, and endothelium. No significant differences were found between PMT and camera CMTF measurements of epithelial, stromal, or corneal thickness (n = 12 scans). Furthermore, a high correlation was found between camera and PMT measurements (linear regression analysis, y = 0.999 x -0.4, r = 0.99, p < 0.001). The data suggest that by adding a pellicle beam splitter, CMTF intensity data can be acquired using a PMT. The PMT has a faster sampling rate and greater dynamic range than the camera and provides a count of the photons detected. Thus, the instrument has the potential for improving corneal pachymetry and back-scattering measurements while still providing high-resolution corneal images. PMID:12166802

Petroll, W Matthew; Yu, Alex; Li, Jie; Jester, James V; Cavanagh, H Dwight; Black, Truman

329

Reflection-contrast limit of fiber-optic image guides  

PubMed Central

Fiber-optic image guides in confocal reflectance endomicroscopes introduce background backscatter that limits the achievable contrast in these devices. We show the dominant source of backscatter from the image guide is due to Rayleigh scattering at short wavelengths and terminal reflections of the fibers at long wavelengths. The effective Rayleigh scattering coefficient and the wavelength-independent reflectivity due terminal reflections are measured experimentally in a commercial image guide. The Rayleigh scattering component of backscatter can be accurately predicted using the fractional refractive-index difference and length of the fibers in the image guide. We also presented a simple model that can be used to predict signal-to-background ratio in a fiber-optic confocal reflectance endomicroscope for biologically relevant tissues and contrast agents that cover a wide range of reflectivity.

Lane, Pierre M.; MacAulay, Calum E.

2009-01-01

330

Terahertz interferometric synthetic aperture tomography for confocal imaging systems.  

PubMed

Terahertz (THz) interferometric synthetic aperture tomography (TISAT) for confocal imaging within extended objects is demonstrated by combining attributes of synthetic aperture radar and optical coherence tomography. Algorithms recently devised for interferometric synthetic aperture microscopy are adapted to account for the diffraction-and defocusing-induced spatially varying THz beam width characteristic of narrow depth of focus, high-resolution confocal imaging. A frequency-swept two-dimensional TISAT confocal imaging instrument rapidly achieves in-focus, diffraction-limited resolution over a depth 12 times larger than the instrument's depth of focus in a manner that may be easily extended to three dimensions and greater depths. PMID:22513671

Heimbeck, M S; Marks, D L; Brady, D; Everitt, H O

2012-04-15

331

Transmission confocal microscopy: making it a reality  

NASA Astrophysics Data System (ADS)

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

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

1998-06-01

332

Compressed Sensing for Multispectral and Confocal Microscopy  

NASA Astrophysics Data System (ADS)

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

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

2007-03-01

333

Image distortion in conventional and confocal microscopy  

NASA Astrophysics Data System (ADS)

A well-known distortion of objects in three-dimensional microscopy manifests itself as an elongation in the axial direction. Authors such as Visser and Hell have seemingly contradicted one another on the cause as well as the magnitude of the effect. We have examined these theories and performed simulations and experimental measurements to better understand the nature of the effect. We simulate point spread functions (based on the work of Gibson) taking into account the various refractive indices involved as well as the magnification, the numerical aperture, the working distance of the objective, the depth of the object under the coverslip, and the object's size. We measure the axial and lateral dimensions of digitized images of microspheres that have been 'acquired' using a simulated point spread function that changes as the depth of the object changes. These simulations are done for conventional (optical sectioning) microscopy as well as for confocal microscopy. Further, we have performed experimental measurements on real microspheres on a conventional microscope to relate theory, simulation, and practice. Our measurements and simulations show that (1) the object's size, (2) its depth under the coverslip, (3) the refractive index mismatch between the immersion fluid (nimmersion) and embedding material for the object (nembedded), and (4) the NA of the lens play a pivotal role in the effect.

Loehner, Simone; Young, Ian T.; Ellenberger, Stephanie L.; de Bakker, Michiel

1999-05-01

334

Active Frequency Selective Surfaces for Antenna Applications Electronically to Control Phase Distribution and Reflective/Transmis siveAmplification.  

National Technical Information Service (NTIS)

A planar dipole grid antenna is described deposited on an active frequency selective (FSS) or polarization sensitive surface (PSS) electronically tuneable to control the spatial phase distribution and reflective/transmissive amplification. Such dipole gri...

P. Edenhofer A. Alpaslan

2005-01-01

335

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

Microsoft Academic Search

Seismic travel time tomography is restricted for the most part either to the direct wave or to 2D. Combined 3D refraction and reflection seismic inversion was first introduced by Zelt et al. (1996) using a \\

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

2002-01-01

336

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

SciTech Connect

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

Mirkarimi, P.B., LLNL

1998-02-20

337

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

338

Submerged Reflectance.  

National Technical Information Service (NTIS)

Techniques for the determination of the submerged reflectance of painted surfaces are described. Absolute reflectance values were obtained of sample surfaces immersed in a large tank. The values were then transferred to laboratory instruments as calibrati...

T. J. Petzold R. W. Austin

1976-01-01

339

High-sensitivity, large dynamic range, auto-calibration methane optical sensor using a short confocal Fabry–Perot cavity  

Microsoft Academic Search

We present a methane sensor based on a short confocal Fabry–Perot cavity. The sensor uses not only the transmitted signals from the back cavity mirror to obtain high sensitivity but also the reflected signals from the front cavity mirror to extend efficient dynamic range and to cancel emitter-amplitude variations. Thus a minimum detectable absorbance of 4.1×10?5 has been achieved and

Lei Dong; Wangbao Yin; Weiguang Ma; Lei Zhang; Suotang Jia

2007-01-01

340

Three-dimensional visualization of dermal skin structure using confocal laser scanning microscopy.  

PubMed

The properties and performance of collagen-based materials may be affected by the collagen fibre bundle pattern, orientation and weave. The aim of this study was to develop and apply methods to visualize the dermis using confocal laser scanning microscopy from thin tissue sections stained with haematoxylin and eosin. The data was processed to allow three-dimensional (3-D) visualization on a PC and using a 3-D immersive technology system. The 3-D visualization of the confocal microscope image stacks allowed the evaluation of the collagen macromolecular structure including the collagen fibre bundles. The methods developed provide a novel way of viewing complex organic structures with further potential applications in the medical field. PMID:23701840

Antunes, A P M; Covington, A D; Petford, N; Murray, T; Wertheim, D

2013-05-23

341

Confocal Laser Endomicroscopy in the Study of Colonic Mucosa in IBD Patients: A Review  

PubMed Central

Confocal laser endomicroscopy (CLE) is one of several novel methods that provide real-time, high-resolution imaging at a micronscale via endoscopes. CLE and related technologies are often termed “virtual biopsy” as they simulate the images seen in traditional histology. 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 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. This report aims to evaluate the current data on the application of confocal endomicroscopy in clinical gastroenterology and particularly in the study of colonic mucosa in UC patients.

Salvatori, Francesca; Siciliano, Saverio; Maione, Francesco; Esposito, Dario; Masone, Stefania; Persico, Marcello; De Palma, Giovanni D.

2012-01-01

342

Feedback phase correction of Bessel beams in confocal line light-sheet microscopy: a simulation study.  

PubMed

Confocal line detection has been shown to improve contrast in light-sheet-based microscopy especially when illuminating the sample by Bessel beams. Besides their self-reconstructing capability, the stability in propagation direction of Bessel beams allows to block the unwanted emission light from the Bessel beam's ring system. However, due to phase aberrations induced especially at the border of the specimen, Bessel beams may not propagate along lines parallel to the slit detector. Here we present a concept of how to correct the phase of each incident Bessel beam such that the efficiency of confocal line detection is improved by up to 200%-300%. The applicability of the method is verified by the results obtained from numerical simulations based on the beam propagation method. PMID:23938439

Moosavi, S Hoda; Gohn-Kreuz, Cristian; Rohrbach, Alexander

2013-08-10

343

4? Confocal Microscope for Mutliphoton Optical Sectioning of GaN Film Luminescence  

NASA Astrophysics Data System (ADS)

In the 4? confocal microscope developed by S. W. Hell et al, laser light coherently illuminates both sides of a thin sample through a pair of high-NA objectives, effectively producing a single standing-wave fringe of 2-photon fluorescence excitation with weak side lobes. Developed initially for biological applications, the 4? microscope of Hell et al demonstrated 75 nm axial resolution with 810 nm light. We have constructed a 4? confocal multiphoton microscope for 3d analysis of band-edge/excitonic photoluminescence in thin films. Excitation is with 130 fs pulses from a Ti:sapphire laser. Instrumental features and preliminary tests with rhodamine and GaN and InN films are reported.

Ucer, K. B.; Liang, Difei; Williams, R. T.; Morkoc, H.

344

4? Confocal Microscope for Multiphoton Optical Sectioning of GaN Film Luminescence  

NASA Astrophysics Data System (ADS)

In the 4? confocal microscope developed by S. W. Hell et al, laser light coherently illuminates both sides of a thin sample through a pair of high-NA objectives, effectively producing a single standing-wave fringe of 2-photon fluorescence excitation with weak side lobes. Developed initially for biological applications, the 4? microscope of Hell et al demonstrated 75 nm axial resolution with 810 nm light. We have constructed a 4? confocal multiphoton microscope for 3d analysis of band-edge/excitonic photoluminescence in thin films. Excitation is with 130 fs pulses from a Ti:sapphire laser. Instrumental features and preliminary tests with rhodamine and GaN and InN films are reported.

Ucer, K. B.; Liang, Difei; Williams, R. T.; Morkoc, H.

2001-08-01

345

Reading Reflections  

NSDL National Science Digital Library

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

Wirth, Karl

346

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

347

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

PubMed Central

We present assembly and application of an optical reflectometer for the analysis of dental erosion. The erosive procedure involved acid-induced softening and initial substance loss phases, which are considered to be difficult for visual diagnosis in a clinic. Change of the specular reflection signal showed the highest sensitivity for the detection of the early softening phase of erosion among tested methods. The exponential decrease of the specular reflection intensity with erosive duration was compared to the increase of enamel roughness. Surface roughness was measured by optical analysis, and the observed tendency was correlated with scanning electron microscopy images of eroded enamel. A high correlation between specular reflection intensity and measurement of enamel softening (r2 ? ?0.86) as well as calcium release (r2 ? ?0.86) was found during erosion progression. Measurement of diffuse reflection revealed higher tooth-to-tooth deviation in contrast to the analysis of specular reflection intensity and lower correlation with other applied methods (r2 = 0.42–0.48). 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; Hoschele, Christoph; Wang, Xiaojie; Beyeler, Barbara; Meier, Christoph; Lussi, Adrian

2011-01-01

348

Scanned light sheet microscopy with confocal slit detection.  

PubMed

In light sheet fluorescence microscopy optical sectioning is achieved by illuminating the sample orthogonally to the detection pathway with a thin, focused sheet of light. However, light scattering within the sample often deteriorates the optical sectioning effect. Here, we demonstrate that contrast and degree of confocality can greatly be increased by combining scanned light sheet fluorescence excitation and confocal slit detection. A high frame rate was achieved by using the "rolling shutter" of a scientific CMOS camera as a slit detector. Synchronizing the "rolling shutter" with the scanned illumination beam results in confocal line detection. Acquiring image data with selective plane illumination minimizes photo-damage while simultaneously enhancing contrast, optical sectioning and signal-to-noise ratio. Thus the imaging principle presented here merges the benefits of scanned light sheet microscopy and line-scanning confocal imaging. PMID:23037300

Baumgart, Eugen; Kubitscheck, Ulrich

2012-09-10

349

Quantitative Fluorescence Imaging with Laser Scanning Confocal Microscopy.  

National Technical Information Service (NTIS)

Scanning confocal microscopy (SCM) offers a dramatic instrumental advantage for fluorescence microscopy through discrimination against out-of-focus background fluorescence, through inherent resolution perpendicular to the plane of focus and improved in-pl...

K. S. Wells D. R. Sandison J. Strickler W. W. Webb

1990-01-01

350

CALIBRATION AND VALIDATION OF CONFOCAL SPECTRAL IMAGING SYSTEMS  

EPA Science Inventory

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

351

WAVELENGTH AND ALIGNMENT TESTS FOR CONFOCAL SPECTRAL IMAGING SYSTEMS  

EPA Science Inventory

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

352

SPECIAL ISSUE DEVOTED TO MULTIPLE RADIATION SCATTERING IN RANDOM MEDIA: Application of backward diffuse reflection spectroscopy for monitoring the state of tissues in photodynamic therapy  

NASA Astrophysics Data System (ADS)

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.

Stratonnikov, Aleksandr A.; Meerovich, G. A.; Ryabova, A. V.; Savel'eva, T. A.; Loshchenov, V. B.

2006-12-01

353

Integration of a confocal Raman microscope in an electron microscope  

NASA Astrophysics Data System (ADS)

In this research project a confocal Raman micro spectrometer (CRM) will be designed and incorporated in a scanning electron microscope (SEM). The aim is to develop a new analytical instrumentation to investigate samples on their morphology, atomic composition and molecular composition. Application of the CRM-SEM is in the field of bio-material research where bio-compatibility with an d bio-degeneration by cells and tissues play an important role. The purposes of CRM is for using in medical, biological, chemical and other field science and technology. The energy of these vibration states depends on the molecular structure and environmental condition like PH, temperature. Therefore, the Raman spectrum contains information about the chemical composition of a substance and the structure of molecules. With CRM we can obtain a 3D image of molecular distribution in living cells or composite materials. In this way it provides directly and non-invasively, unique information about the spatial distribution of molecules in inhomogeneous systems. It is important information for such molecules as DNA, protein and other, where a lot of properties their molecules depends on configuration in space. Combining the capacities of the SEM and the CRM will add a powerful device for material investigation.

Aksenov, Y. Y.; Reinders, E. G.; Greve, Jan; van Blitterswijk, C.; de Bruijn, J.; Otto, Cees

2000-12-01

354

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

355

Digital-micromirror-device-based confocal 4D microscopy  

NASA Astrophysics Data System (ADS)

Digital Micromirror Device based microscopy combines fast confocal 4D-microscopy along with conventional methods for light microscopy and new technological approaches to a versatile tool for the observation of in vivo processes in living biological cells and measurement of technical surfaces. Due to the use of variable size pinholes and adjustable scan patterns conditions for confocal measurement can easily be optimized to the prerequisites of the sample "on the fly".

Schellenberg, M.; Kloster, M.; Napier, J.; Peev, E.; Neu, W.

2012-02-01

356

Confocal microscopy in cornea guttata and Fuchs’ endothelial dystrophy  

Microsoft Academic Search

AIMSTo report the appearances of cornea guttata and Fuchs’ endothelial dystrophy from white light confocal microscopy.METHODSSeven eyes of four consecutive patients with cornea guttata were prospectively examined. Of the seven eyes, three also had corneal oedema (Fuchs’ dystrophy). In vivo white light tandem scanning confocal microscopy was performed in all eyes. Results were compared with non-contact specular microscopy.RESULTSSpecular microscopy was

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

1999-01-01

357

Lateral resolution enhancement in confocal self-interference microscopy  

NASA Astrophysics Data System (ADS)

Lateral resolution enhancement in confocal self-interference microscopy (CSIM) is evaluated. CSIM, which uses the birefringence of the calcite plate to generate self-interference pattern, sharpens the central lobe of the effective spot. Numerical simulation results of two-dimensional imaging performances are presented. Two-point resolution of 149nm is achieved, which is enhanced by nearly 100% compared to that of confocal microscopy.

Kang, DongKyun; Gweon, DaeGab

2005-03-01

358

[Technique of confocal Raman microscopy on erythrocytes].  

PubMed

The technique of confocal Raman scanning microscopy (point scanning, line scanning and 2D scanning) and bright field imaging of living erythrocytes was investigated as a function of different scanning conditions at the excitation wavelength of 514 nm. The biological effect of the 514 nm laser radiation on the erythrocytes was also evaluated, so that a set of proper scanning parameters for different scan modes can be determined to obtain strong enough Raman signal while without damage on the living cells by evaluating the change of Raman spectra and lighted field images of the cells. For the point scanning mode, the laser power at sample is the most important parameter to be adjusted, which normally should be less than 1.5 mW. For the line scanning mode, the laser power at sample and scanning step should be considered at first. Small scanning step means the energy of laser accumulated at a small region, which can easily damage to erythrocytes. Large scanning step can reduce the damage; however the spatial resolution decreases also. It is recommended that scanning step should be more than 0.5 microm and laser power at sample should be less than 0.7 mW. For the 2D scanning mode, besides the laser power at sample, scan step needs to be adjusted, and other scan parameters need to be adjusted properly for reducing the effect of laser on erythrocytes. Large pinhole and relative low temperature of sample are the remedies, which can reduce the effect of laser on erythrocytes. 1.0 microm scanning step, 0.7 mW laser power at sample, 500 microm pinhole and proper low temperature can get better 2D Raman image of erythrocytes. For all scanning modes, if the Raman signal is strong enough, the exposure time can be shortened properly, thus reducing the effect of laser on erythrocytes. The optimization of experiment process is also important for Raman test on living cells. PMID:19123403

Kang, Li-li; Huang, Yao-xiong; Luo, Man

2008-10-01

359

Numerical calculation of the reflectance of sub-wavelength structures on silicon nitride for solar cell application  

NASA Astrophysics Data System (ADS)

In this study, we calculate the spectral reflectivity of pyramid-shaped silicon nitride (Si3N4) sub-wavelength structures (SWS). A multilayer rigorous coupled-wave approach is advanced to investigate the reflection properties of Si3N4 SWS. We examine the simulation results for single layer antireflection (SLAR) and double layer antireflection (DLAR) coatings with SWS on Si3N4 surface, taking into account effective reflectivity over a range of wavelengths and solar efficiency. The results of our study show that a lowest effective reflectivity of 1.77% can be obtained for the examined Si3N4 SWS with the height of etched part of Si3N4 and the thickness of non-etched layer of 150 and 70 nm, respectively, which is less than the results of an optimized 80 nm Si3N4 SLAR (˜5.41%) and of an optimized DLAR with 80 nm Si3N4 and 100 nm magnesium fluoride (˜5.39%). 1% cell efficiency increase is observed for the optimized Si solar cell with Si3N4 SWS, compared with the cell with single layer Si3N4 antireflection coatings (ARCs); furthermore, compared with DLAR coated solar cell, the increase is about 0.71%. The improvement on the cell efficiency is mainly due to lower reflectance of Si3N4 SWS over a wavelength region from 400 to 600 nm that leads to lower short circuit current.

Sahoo, Kartika Chandra; Li, Yiming; Chang, Edward Yi

2009-10-01

360

Model for land surface reflectance treatment: Physical derivation, application for bare soil and evaluation on airborne and satellite measurements  

NASA Astrophysics Data System (ADS)

For land surfaces and atmospheric aerosol characterization on the basis of satellite and airborne measurements models for surface reflection description are required. At present time for visible and infrared spectral regions semi-empirical model for surface reflection are usually used for these purposes. Due to the lack of physical basis, these models introduce a lot of uncertainties into the problem of aerosol and surface properties retrieval. In this paper we consider the possibility of using physically based models for bidirectional reflection matrix (BRM) which can be applied to the problem of simultaneous retrieval of aerosol and land surface properties. The physical model for the BRM is derived from the general solution of the electromagnetic scattering problems by random media. The equation for the reflection matrix is obtained within the far-field approximation when the ladder scattering diagrams are taken into account. To perform analytical averaging over orientation of the surface elements we assume that at different scales the surface can be considered as the Gaussian surface. We use multi-angle photopolarimetric airborne measurements of the Research Scanning Polarimeter (RSP) and satellite POLDER (Polarization and Directionality of the Earth's Reflectances) measurements to investigate the performance of the presented BRM model. The results of the comparison are discussed.

Litvinov, Pavel; Hasekamp, Otto; Dubovik, Oleg; Cairns, Brian

2012-11-01

361

Confocal microscopy in cornea guttata and Fuchs' endothelial dystrophy  

PubMed Central

AIMS—To report the appearances of cornea guttata and Fuchs' endothelial dystrophy from white light confocal microscopy.?METHODS—Seven eyes of four consecutive patients with cornea guttata were prospectively examined. Of the seven eyes, three also had corneal oedema (Fuchs' dystrophy). In vivo white light tandem scanning confocal microscopy was performed in all eyes. Results were compared with non-contact specular microscopy.?RESULTS—Specular microscopy was precluded by corneal oedema in one eye. In the remaining six eyes, it demonstrated typical changes including pleomorphism, polymegathism, and the presence of guttae appearing as dark bodies, some with a central bright reflex. In all seven eyes, confocal microscopy revealed the presence of round hyporeflective images with an occasional central highlight at the level of the endothelium. Changes in cell morphology and size were readily appreciated.?CONCLUSION—By comparison with specular microscopy, the hyporeflective images with an occasional central highlight seen on confocal microscopy are consistent with the presence of guttae. Confocal microscopy may confirm the diagnosis of cornea guttata and Fuchs' endothelial dystrophy by demonstrating the presence of guttae. This technique is especially valuable in cases of corneal oedema, where specular microscopy may fail to visualise the endothelium. However, specular microscopy should remain the method of choice to evaluate the endothelium, principally because it is easier to use. ?? Keywords: confocal microscopy; cornea guttata; Fuchs' dystrophy

Chiou, A.; Kaufman, S.; Beuerman, R.; Ohta, T.; Soliman, H.; Kaufman, H.

1999-01-01

362

Combining confocal microscopy with precise force-scope optical tweezers  

NASA Astrophysics Data System (ADS)

We demonstrate an example of 'confocal-tweezers' wherein confocal images and precise optical force measurements, using photodiodes, are obtained simultaneously in the x-y plane without moving the objective lens. The optical trap is produced using a 1.064?m cw laser and is combined with Leica's TCS SP5 broadband confocal microscope to trap and image living cells. The unique method by which the confocal images are created facilitates the acquisition of images in areas far from the trapping location. In addition, because the scanning process involves moving galvanic mirrors independently of the objective, the trap is held stable in position and is not subject to any error in position for the x-y scan. We have successfully trapped and confocally imaged 80nm gold colloids, 150nm gold colloids and 1?m polystyrene beads whilst making quantitative measurements of the force applied by the trap on each bead. To the best of our knowledge this is the first time that anyone has combined precise force measuring optical tweezers with confocal microscopy. We also discuss some of the technical challenges involved in advancing the experimental set up to make quantitative force measurements in combination with 3D stacking. Having proven the potential of this system in 2D, we hope to develop it further to investigate the nano-mechanics of cell division through the attachment of gold beads to fluorescently labelled organelles in S. pombe yeast cells.

Richardson, Andrew C.; Reihani, Nader; Oddershede, Lene B.

2006-09-01

363

Anti resonant reflecting optical waveguide structure based on oxidized porous silicon for label free bio sensing applications  

NASA Astrophysics Data System (ADS)

In this letter we report on the use of an electrochemical process for the fabrication of anti resonant reflecting optical waveguide based on oxidized porous silicon. This method is known to allow the formation of various photonic structures (Bragg mirror, microcavity), thanks to the easy and in situ modulation of the porosity and thus of the refractive index. Planar anti resonant reflecting optical waveguide structure made from porous silicon is demonstrated to be very effective for low losses as compared to conventional resonant waveguide. Optical measurements carried out for TE and TM polarizations are reported and related to optical sensing.

Haji, L.; Hiraoui, M.; Lorrain, N.; Guendouz, M.

2012-03-01

364

Portable oral cancer detection using a miniature confocal imaging probe with a large field of view  

Microsoft Academic Search

We demonstrate a MEMS micromirror enabled handheld confocal imaging probe for portable oral cancer detection, where a comparatively large field of view (FOV) was generated through the programmable Lissajous scanning pattern of the MEMS micromirror. Miniaturized handheld MEMS confocal imaging probe was developed, and further compared with the desktop confocal prototype under clinical setting. For the handheld confocal imaging system,

Youmin Wang; Milan Raj; H. Stan McGuff; Gauri Bhave; Bin Yang; Ting Shen; Xiaojing Zhang

2012-01-01

365

Improvement of lateral resolution property of differential confocal system using radial birefringent pupil filter  

Microsoft Academic Search

Lateral resolution, as one of the most important parameters of a confocal system, has a direct effect on the measurement accuracy of a confocal system. The lateral resolution of a confocal system can be improved by introducing a radial birefringent pupil filter into a differential confocal system. The pupil function of this radial birefringent pupil filter can be obtained using

Li Min Zou; Xi Li; Hong Ji Zhang; Xue Mei Ding

2008-01-01

366

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

367

New developments in CCD imaging devices for low-level confocal light imaging  

NASA Astrophysics Data System (ADS)

Charge coupled devices (CCD) have several advantages over tube camera imaging devices. These advantages include: geometric stability, high dynamic range (12, 14, or 16 bits) and photometric linearity. In order to achieve low-readout noise the readout is usually limited to 50 kpixels per second. The readout time is several times longer than video rates; the slow readout at less than video rates is the major disadvantage. A new CCD imager has been coupled to a Nipkow disk, confocal light microscope and its performance is evaluated using both reflected light and low-light-level fluorescence imaging. The CCD imager is a TK515, silicon CCD which is sensitiveequalsve from the UV to the near-IR. The sensor is a full frame area imager, with CCDs fabricated using a buried channel, three-level polysilicon gate process with very high charge-transfer efficiency (>0.9999) and low dark current. Low noise on-chip amplifiers provide and interface to external preamplifiers with readout noise typically <10 electrons at -90 degree(s) C, and 50 kpixels/second data rate. The chip is a thinned, back-illuminated device with anti-reflection coatings. The quantum efficiency is >80% at 400 nm and >90% at 600 nm. To determine its performance the Tektronix CCD was mounted in a Photometrics liquid cooled camera, attached to a Technical Instruments K2Bio confocal microscope.

Masters, Barry R.

1991-05-01

368

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

Technology Transfer Automated Retrieval System (TEKTRAN)

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

369

Application of micro-attenuated total reflectance FTIR spectroscopy in the forensic study of questioned documents involving red seal inks  

Microsoft Academic Search

Red seal inks from Korea (6), Japan (1) and China (6) were studied to investigate the feasibility of micro-attenuated total reflectance (ATR) FTIR spectroscopy as a tool in the forensic study of questioned documents involving seal inks. The technique was able to differentiate red seal inks of similar colors and different manufacturers. Blind testing has shown that micro-ATR FTIR can

Warnadi Dirwono; Jin Sook Park; M. R. Agustin-Camacho; Jiyeon Kim; Hyun-Mee Park; Yeonhee Lee; Kang-Bong Lee

2010-01-01

370

New hybrid reflectance optical pulse oximetry sensor for lower oxygen saturation measurement and for broader clinical application  

Microsoft Academic Search

A new reflectance pulse oximeter sensor for lower arterial oxygen saturation (Sa)2) measurement has been designed and evaluated in animals prior to clinical trials. The new sensor incorporates ten light emitting diode chips for each wavelength of 730 and 880 nm mounted symmetrically and at the radial separation distance of 7 mm around a photodiode chip. The separation distance of

Masamichi Nogawa; Chong Thong Ching; Takeyuki Ida; Keiko Itakura; Setsuo Takatani

1997-01-01

371

Surface Morphology and Optical Reflection of Thermally Evaporated Thin Film Al-Doped Silicon on Plastic Substrates for Solar Cells Applications  

NASA Astrophysics Data System (ADS)

In this paper, authors have investigated the surface morphology and optical reflection of thermally evaporated thin film silicon (Si) on plastic substrates (polyethylene terephthalate, PET) at different aluminium (Al) composition (denoted by Al/Si ratio) for applications in solar cells. Results show that the thermally evaporated p-type Si possesses fairly smooth surfaces as characterised by atomic force microscopy (AFM) images. The films exhibit low surface roughness root mean square (RMS) of 9-12 nm as Al/Si ratio increases from 0.08 to 0.4. Intrinsic Si thin film shows roughness RMS of 9.2 nm, indicates that surface roughness is independent of Al composition within the thin film. Al/Si 0.08 gives the lowest reflectivity of around 10% (averaged in the visible region). Increase in the surface reflectivity is evident as the Al/Si ratio increases due to an increase in the number of Al crystallites distributed within the film. Overall, this experiment reveals the natural morphology of low roughness RMS (hence poor light-trapping) from thermal evaporation method due to its directional deposition nature. An extra step of surface texturing would be needed to enhance the light trapping properties of the absorber layer (p-type Si). Optimization of the Al doping level is vital in order to maintain minimum reflection losses in the device.

Pakhuruddin, Mohd Zamir; Ibrahim, Kamarulazizi; Mohammed Ali, Mohammed Khaleel; Aziz, Azlan Abdul

2011-05-01

372

The NIST Robotic Optical Scatter Instrument (ROSI) and its application to BRDF measurements of diffuse reflectance standards for remote sensing  

NASA Astrophysics Data System (ADS)

We describe the robotic optical scatter instrument (ROSI), a new robotic arm-based goniometer for in-plane and outof- plane reflectance and bidirectional reflectance distribution function (BRDF) measurements of surfaces. The goniometer enables BRDF measurements to be made at nearly any combination of incident and scattering angles, without obstruction from frames or cradles that occur in traditional goniometers made of nested rotation stages. We present exploratory measurements of in-plane and hemispherically-scanned out-of-plane BRDF on a sintered white polytetrafluoroethylene (PTFE) sample using a supercontinuum fiber laser-based tunable light source operated at a wavelength of 550 nm, in order to demonstrate the capabilities of the system. An initial assessment of uncertainties is presented.

Patrick, Heather J.; Zarobila, Clarence J.; Germer, Thomas A.

2013-09-01

373

A reflectivity climatology algorithm for hybrid scans and its application to radar coverage over the Tibetan Plateau  

NASA Astrophysics Data System (ADS)

The traditional algorithm for hybrid radar scans uses standard terrain digital elevation model (DEM) data and the latitudes, longitudes and altitudes of contributing radar stations. While radar station location information is often inaccurate, signal blockages due to trees, buildings, and other surface objects are not included in the DEM data. Accordingly, hybrid scan elevations derived using this traditional algorithm are prone to errors. Here, reflectivity climatology data (the frequency of occurrence of reflectivity) are used to improve the algorithm for hybrid scans. Three parameters are introduced, then applied to evaluation of signal blockage for every radar bin using a fuzzy logic technique. This new algorithm provides an improved determination of the lowest unblocked elevation for hybrid scans. The new algorithm is validated by examining the scope and continuity of the calculated hybrid scan reflectivity in a case study, and the performance of this climatology-based algorithm is evaluated relative to the traditional terrain-based algorithm. The climatology-based hybrid scans are then used to examine the spatial coverage provided by the operational weather radar network over the Tibetan Plateau. The results indicate that the terrain-based hybrid scan algorithm introduced errors that caused obvious V-shaped gaps in hybrid scan reflectivity. By contrast, the climatology-based hybrid scan algorithm more accurately determined the lowest unblocked elevation and reduced the impacts of blockage. The coverage map illustrates the limitations of the weather radar network over the Tibetan Plateau. These limitations inhibit the usefulness of the radar data. Additional radar or observational data are needed to fill these gaps and minimize the impacts of signal blockage.

Zhuang, Wei; Liu, Liping

2012-12-01

374

Delineation of surfaces by skeletonization: Application to interpretation of 3D seismic reflection and georadar data volumes  

Microsoft Academic Search

A new 3-D skeletonization technique based on a four-cycle correlation allows automatic event detection and mapping of surfaces in any 3-D volume of reflection seismic data. Interpretation results are comparable to those derived using conventional 3-D interpretation packages. Furthermore, a product of skeletonization is a surface file containing a variety of seismic attributes for each identified surface that can be

Kris Vasudevan; Peter Tozser; Frederick A. Cook

1997-01-01

375

New hybrid reflectance optical pulse oximetry sensor for lower oxygen saturation measurement and for broader clinical application  

NASA Astrophysics Data System (ADS)

A new reflectance pulse oximeter sensor for lower arterial oxygen saturation (Sa)2) measurement has been designed and evaluated in animals prior to clinical trials. The new sensor incorporates ten light emitting diode chips for each wavelength of 730 and 880 nm mounted symmetrically and at the radial separation distance of 7 mm around a photodiode chip. The separation distance of 7 mm was chosen to maximize the ratio of the pulsatile to the average plethysmographic signal level at each wavelength. The 730 and 880 wavelength combination was determined to obtain a linear relationship between the reflectance ratio of the 730 and 880 nm wavelengths and Sa)2. In addition to these features of the sensor, the Fast Fourier Transform method was employed to compute the pulsatile and average signal level at each wavelength. The performance of the new reflectance pulse oximeter sensor was evaluated in dogs in comparison to the 665/910 nm sensor. As predicted by the theoretical simulation based on a 3D photon diffusion theory, the 730/880 nm sensor demonstrated an excellent linearity over the SaO2 range from 100 to 30 percent. For the SaO2 range between 100 and 70 percent, the 665/910 and 730/880 sensors showed the standard error of around 3.5 percent and 2.1 percent, respectively, in comparison to the blood samples. For the range between 70 and 30 percent, the standard error of the 730/880 nm sensor was only 2.7 percent, while that of the 665/910 nm sensor was 9.5 percent. The 730/880 sensor showed improved accuracy for a wide range of SaO2 particularly over the range between 70 and 30 percent. This new reflectance sensor can provide noninvasive measurement of SaO2 accurately over the wide saturation range from 100 to 30 percent.

Nogawa, Masamichi; Ching, Chong Thong; Ida, Takeyuki; Itakura, Keiko; Takatani, Setsuo

1997-06-01

376

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

Microsoft Academic Search

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

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

1974-01-01

377

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

Microsoft Academic Search

Seismic travel time tomography is restricted for the most part either to the direct wave or to 2D. Combined 3D refraction and reflection seismic inversion of DSS data was introduced by Zelt et al. (1996) using a quasi-simultaneous procedure of alternating inversions of a certain seismic phase and layer stripping. We developed a 3D method to invert simultaneously for slowness

F. Bleibinhaus; G. Helmut

2002-01-01

378

Let's Reflect  

NSDL National Science Digital Library

This activity allows students to investigate line symmetry and reflections. Using a mirror, students locate the lines of symmetry. in a square and then proceed to find other shapes by reflecting parts of the square. Ideas for implementation, extension and support are included along with a printable worksheet of squares (.doc)

2003-08-01

379

Reflected Glory  

ERIC Educational Resources Information Center

|The scientific model of how people see things is far removed from children's real-world experience. They know that light is needed in order to see an object, but may not know that light is reflected off the object and some of that light enters the eyes. In this article, the author explores children's understanding of reflection and how to develop…

Forster, Colin

2006-01-01

380

Reflected Glory  

ERIC Educational Resources Information Center

The scientific model of how people see things is far removed from children's real-world experience. They know that light is needed in order to see an object, but may not know that light is reflected off the object and some of that light enters the eyes. In this article, the author explores children's understanding of reflection and how to develop…

Forster, Colin

2006-01-01

381

Confocal microscope method for curvature radius measurement of small lens  

NASA Astrophysics Data System (ADS)

With the minimization of optical devices, the size of lens becomes much smaller. As a crucial parameter of spherical lens, the measurement of curvature radius is valuable in small lens manufacturing. In this paper, confocal microscope method is proposed to measure curvature radius of spherical lens, especially small spherical lens. The setup of this method consists of a confocal microscope and a grating bar. The detector of confocal microscope gives maximum output when the spherical surface is placed at "cat's eye" position or confocal position. The distance between cat's eye and confocal position is the curvature radius of spherical surface. This method is suitable for both concave and convex surface. The response of detector to axial and traversal displacement is analyzed and simulated. And the measurement error is estimated with the simulated results. The setup employed a 10x microscope objective of 0.2 NA and pinhole of 0.04mm diameter, and experiment was conducted to measure the radius of a standard optical ball of 3mm diameter. The error of result is less than 0.01mm. It's concluded that the error could be reduced less than 0.001mm with higher numerical aperture and more precise movement stages.

Liu, Qian; Yang, Weichuan; Wu, Pengyue; Yuan, Daocheng

2012-10-01

382

Fused oblique incidence reflectometry and confocal fluorescence microscopy  

NASA Astrophysics Data System (ADS)

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

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

2011-02-01

383

In vivo laser confocal microscopy findings in patients with map-dot-fingerprint (epithelial basement membrane) dystrophy  

PubMed Central

Background: The purpose of this study was to investigate pathological changes of the corneal cell layer in patients with map-dot-fingerprint (epithelial basement membrane) dystrophy by in vivo laser corneal confocal microscopy. Methods: Two patients were evaluated using a cornea-specific in vivo laser scanning confocal microscope (Heidelberg Retina Tomograph 2 Rostock Cornea Module, HRT 2-RCM). The affected corneal areas of both patients were examined. Image analysis was performed to identify corneal epithelial and stromal deposits correlated with this dystrophy. Results: Variously shaped (linear, multilaminar, curvilinear, ring-shape, geographic) highly reflective materials were observed in the “map” area, mainly in the basal epithelial cell layer. In “fingerprint” lesions, multiple linear and curvilinear hyporeflective lines were observed. Additionally, in the affected corneas, infiltration of possible Langerhans cells and other inflammatory cells was observed as highly reflective Langerhans cell-like or dot images. Finally, needle-shaped materials were observed in one patient. Conclusion: HRT 2-RCM laser confocal microscopy is capable of identifying corneal microstructural changes related to map-dot-fingerprint corneal dystrophy in vivo. The technique may be useful in elucidating the pathogenesis and natural course of map-dot-fingerprint corneal dystrophy and other similar basement membrane abnormalities.

Kobayashi, Akira; Yokogawa, Hideaki; Sugiyama, Kazuhisa

2012-01-01

384

Reflecting on Reflecting on Practice  

ERIC Educational Resources Information Center

|This article discusses three broad themes--reflection, power, and negotiation--that are evidenced in all of the articles in this issue. In this article, the author tries to transgress the articles at some middling altitude to seek some broader thematics. His observations about reflection, power, and negotiation do transcend individual efforts,…

Wilson, Arthur L.

2009-01-01

385

Retrieval of tropospheric aerosol properties over land from visible and near-infrared spectral reflectance: Application over Maryland  

NASA Astrophysics Data System (ADS)

Aerosols are major components of the Earth's global climate system, affecting the radiation budget and cloud processes of the atmosphere. When located near the surface, high concentrations lead to lowered visibility, increased health problems and generally reduced quality of life for the human population. Over the United States mid-Atlantic region, aerosol pollution is a problem mainly during the summer. Satellites, such as the MODerate Imaging Spectrometer (MODIS), from their vantage point above the atmosphere, provide unprecedented coverage of global and regional aerosols over land. During MODIS' eight-year operation, exhaustive data validation and analyses have shown how the algorithm should be improved. This dissertation describes the development of the 'second-generation' operational algorithm for retrieval of global tropospheric aerosol properties over dark land surfaces, from MODIS-observed spectral reflectance. New understanding about global aerosol properties, land surface reflectance characteristics, and radiative transfer properties were learned in the process. This new operational algorithm performs a simultaneous inversion of reflectance in two visible channels (0.47 and 0.66 mum) and one shortwave infrared channel (2.12 mum), thereby having increased sensitivity to coarse aerosol. Inversion of the three channels retrieves the aerosol optical depth (tau) at 0.55 mum, the percentage of non-dust (fine model) aerosol (eta) and the surface reflectance. This algorithm is applied globally, and retrieves tau that is highly correlated (y = 0.02 + 1.0x, R=0.9) with ground-based sunphotometer measurements. The new algorithm estimates the global, over-land, long-term averaged tau ˜ 0.21, a 25% reduction from previous MODIS estimates. This leads to reducing estimates of global, non-desert, over-land aerosol direct radiative effect (all aerosols) by 1.7 W·m-2 (0.5 W·m-2 over the entire globe), which significantly impacts assessment of aerosol direct radiative forcing (contribution from anthropogenic aerosols only). Over the U.S. mid-Atlantic region, validated retrievals of tau (an integrated column property) can help to estimate surface PM2.5 concentration, a monitored criteria air quality property. The 3-dimensional aerosol loading in the region is characterized using aircraft measurements and the Community Multi-scale Air Quality Model (CMAQ) model, leading to some convergence of observed quantities and modeled processes.

Levy, Robert Carroll

386

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

387

Theoretical analysis of multiprobe confocal 3-D detection system  

NASA Astrophysics Data System (ADS)

To solve the problem of slow speed in single point scanning confocal measurement, a new way to make 3-D morphology confocal detection by optical fiber beam is presented. In the new system, with the point light source produced by optical fiber array and light intensity information detected by pinhole array, the synchronous scanning of the measured surface is done. Compared to the multi-probe detection system of lens array, the new system has the characteristics of simple structure and low price. Based on the general confocal principle and with Fourier optics theory, the 3-D point spread function of a simple fiber pinhole pair is got. With the matrix operating form, the imaging characteristic of the multi-probe measurement system is analyzed. Meanwhile, the conclusion of theoretical analysis shows the total light distribution of the multi-probe detection system conforms to the multiplication form of each detection light path.

Li, Hai-yan; Pu, Zhao-bang

2007-03-01

388

Application of deformable mirrors in industrial CO{sub 2} lasers. I. A mirror with a controllable curvature of the reflecting surface  

SciTech Connect

Single-channel deformable mirrors with a controllable curvature of the reflecting surface are analysed. The advantages of bimorph deformable optics over mirrors controlled by a piezoelectric actuator are demonstrated. Experiments showed that the sensitivity of controllable bimorph mirrors nonlinearly increases (up to 30 %) at high electric voltages; and dynamic operating modes of these mirrors are characterised by an increase in their temperature and capacitance under the action of an alternating control voltage. A focusing laser head (the focal length is 100 - 500 mm) containing a deformable mirror was simulated, and experiments on the control of a focused laser beam were performed. (laser applications and other topics in quantum electronics)

Vyskubenko, O B; Kapustin, P I; Kolokolov, I S; Masychev, V I; Safronov, A G ['Komposit' Research and Production Association (Russian Federation)

2003-06-30

389

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

390

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

391

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

392

Role of Confocal Laser Endomicroscopy in Detection of Residual Barrett's Esophagus after Radiofrequency Ablation  

PubMed Central

Endoscopic endoluminal radiofrequency ablation (RFA) is a novel and promising modality for Barrett's esophagus (BE) treatment. Actually the only surveillance method after the ablation treatment is random biopsies throughout the whole treated area. Confocal laser endomicroscopy (CLE) is a new endoscopic imaging tool that permits high-resolution microscopic examination of the gastrointestinal tract. The technology has garnered increasing attention because of its ability to provide real-time “optical” biopsy specimens, with a very high sensitivity and specificity. This paper summarize the potential application of CLE in the surveillance of the reepithelialization of BE, after endoscopic RFA.

Diamantis, Giorgio; Bocus, Paolo; Realdon, Stefano; Battaglia, Giorgio

2011-01-01

393

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

PubMed Central

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

2012-01-01

394

Nonlinear Confocal Microscopy for High-Resolution Measurement  

NASA Astrophysics Data System (ADS)

We demonstrate cell imaging with a new confocal nonlinear optical microscope using a low-power cw laser. The confocal nonlinear optical microscope, employing degenerate four-wave mixing geometry, can detect the fine structure of submicron objects with nanoscale contents such as biological cells. The optical signal, which is given by the third-order susceptibility tensor, is confined to the focal region of the focusing incident beam, because the absorption of the object is dependent on the third power of the excitation laser intensity. We have observed a thylakoid membrane in a chloroplast by scanning the tensor element inside.

Egami, Chikara; Ito, Atsuo; Liu, Yingzhi

2008-08-01

395

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

396

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.

2011-02-01

397

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

398

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

NASA Astrophysics Data System (ADS)

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

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

2002-05-01

399

Design and optimization of tracking in a confocal microscope  

NASA Astrophysics Data System (ADS)

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

Shen, Zhaolong

400

Application of thin-film interference coatings in infrared reflection spectroscopy of organic samples in contact with thin metal films.  

PubMed

A thin dielectric IR-transparent interlayer is introduced between an IR-transparent medium of incidence and a thin metal film. The interlayer increases the intensity of light on the metal/sample interface at certain wavenumbers. By computations, the reflectivities of the system "calcium fluoride (CaF)-germanium (Ge)-gold (Au) sample" are analyzed as a function of incidence angle and Ge layer thickness. Absorbance spectra with acetonitrile as a sample are recorded for different angles of incidence and polarizations and compared to computations. A characteristic feature of the absorbance spectra is the occurrence of interference fringes distributed between 1000 and 6000?cm(-1), i.e., over the complete mid-IR wavelength range into the near-IR. These fringes could be used in analytical spectroscopy. PMID:21460955

Reithmeier, Martina; Erbe, Andreas

2011-03-20

401

Application of micro-attenuated total reflectance FTIR spectroscopy in the forensic study of questioned documents involving red seal inks.  

PubMed

Red seal inks from Korea (6), Japan (1) and China (6) were studied to investigate the feasibility of micro-attenuated total reflectance (ATR) FTIR spectroscopy as a tool in the forensic study of questioned documents involving seal inks. The technique was able to differentiate red seal inks of similar colors and different manufacturers. Blind testing has shown that micro-ATR FTIR can identify the origin of the red seal inks with accuracy. Data gathered were converted to a database for future reference. Also, the technique was also successful in determining the sequence of heterogeneous line intersection from a personal seal and a ballpoint pen. The results show that micro-ATR FTIR can be a valuable non-destructive tool for the objective analysis of questioned documents involving different red seal inks. PMID:20413232

Dirwono, Warnadi; Park, Jin Sook; Agustin-Camacho, M R; Kim, Jiyeon; Park, Hyun-Mee; Lee, Yeonhee; Lee, Kang-Bong

2010-04-21

402

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

NASA Astrophysics Data System (ADS)

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

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

2002-12-01

403

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

SciTech Connect

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

NONE

1998-02-18

404

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

2013-03-08

405

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.

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

2010-01-01

406

In vivo biopsy by laser confocal microscopy for evaluation of traumatic recurrent corneal erosion  

PubMed Central

Purpose Laser in vivo confocal microscopy noninvasively provides images that are equivalent to high quality histology. We have now applied this technique to identify pathological characteristics of traumatic recurrent corneal erosion (RCE). Methods Six eyes of six patients with traumatic RCE were studied. Corneas were examined with a slit lamp biomicroscope and with a laser in vivo confocal microscope (Heidelberg Retina Tomograph II–Rostock Cornea Module or HRTII-RCM) at various times after the onset of the most recent recurrence of corneal erosion. Results Brightly reflective granular structures were detected by the HRTII-RCM system in the basal and wing cell layers of the corneal epithelium in all eyes affected by recurrent erosion. Activated keratocytes and scattered fine particles were also apparent in the shallow stroma of five of the six affected eyes. These features were not observed in the normal cornea. Conclusions The HRTII-RCM system allows detection of characteristic abnormal structures in the cornea of individuals with traumatic RCE. The presence of granular structures in the corneal epithelium as well as persistent inflammation in the shallow stroma may contribute to the deterioration of the corneal epithelial cell alignment and to the weakening of adhesion between the basal epithelial cells and the basement membrane in RCE lesions.

Takahashi, Norihisa; Wakuta, Makiko; Morishige, Naoyuki; Nishida, Teruo

2008-01-01

407

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

NASA Astrophysics Data System (ADS)

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

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

2012-11-01

408

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

409

Automated compensation of light attenuation in confocal microscopy by exact histogram specification.  

PubMed

Confocal laser scanning microscopy (CLSM) enables us to capture images representing optical sections on the volume of a specimen. The images acquired from different layers have a different contrast: the images obtained from the deeper layers of the specimen will have a lower contrast with respect to the images obtained from the topmost layers. The main reasons responsible for the effects described above are light absorption and scattering by the atoms and molecules contained in the volume through which the light passes. Also light attenuation can be caused by the inclination of the observed surface. In the case of the surfaces that have a steep inclination, the reflected light will have a different direction than the one of the detector. We propose a technique of digital image processing that can be used to compensate the effects of light attenuation based on histogram operations. We process the image series obtained by CLSM by exact histogram specification and equalization. In this case, a strict ordering among pixels must be induced in order to achieve the exact histogram modeling. The processed images will end up having exactly the specified histogram and not a histogram with a shape that just resembles to the specified one, as in the case of classical histogram specification algorithms. Experimental results and theoretical aspects of the induced ordering are discussed, as well as a comparison between several histogram modeling techniques with respect to the processing of image series obtained by confocal microscopy. PMID:19725065

Stanciu, Stefan G; Stanciu, George A; Coltuc, Dinu

2010-03-01

410

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

PubMed

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

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

411

The development of the Reflection Grating Spectrometer on board the XMM-Newton Observatory and its application to the study of accretion-powered sources  

NASA Astrophysics Data System (ADS)

The Reflection Grating Spectrometer on board the European Space Agency's XMM-Newton Observatory is the main subject of the thesis. It was designed to provide high-throughput, high-resolution spectroscopy in the soft X-ray band of 5 to 35 Å. The primary optical component is the Reflection Grating Array. The individual gratings were extensively calibrated at Columbia University's Nevis Laboratories. The grating array was assembled at Nevis and then calibrated as part of the integrated spectrometer at the Panter X-ray Test Facility. A description of the instrument calibration will be presented. The spectrometer is characterized by a full physical model. The physical model of the spectral reflectivity of the gratings will be described. It is based on the vector solution to Maxwell's equations, and it successfully reproduces the ground calibration data. The grating model is included with the physical models of each component along the optical path to construct the effective area model of the full spectrometer. The effective area model and comparisons with the ground and in-flight calibration data will also be described. The Reflection Grating Spectrometer can be used for high-resolution spectroscopy of X-ray emitting plasmas in a range of astophysical settings. The discrete features in the observed spectra are sensitive to the physical conditions of the emitting plasma. These features can therefore be used to quantitatively measure the temperature, density, velocity, and geometry of the material. This thesis will describe the application of high-resolution spectroscopy to the study of accretion-powered sources. The spectral analysis of two low-mass X-ray binaries will be presented. The first is EXO 0748-67, which was observed with XMM-Newton . The second is 4U 1822-37, which was observed with the Chandra X-ray Observatory.

Cottam, Jean

2001-09-01

412

Reflection\\/transmission confocal microscopy characterization of single-crystal diamond microlens arrays  

Microsoft Academic Search

Using the method of photoresist reflow and inductively coupled plasma dry etching, we have fabricated microlens arrays in type-IIa natural single-crystal diamond, with diameters down to 10 mum. The surface profile of the microlenses was characterized by atomic force microscopy and was found to match well with a spherical shape, with a surface roughness of better than 1.2 nm. To

E. Gu; H. W. Choi; C. Liu; C. Griffin; J. M. Girkin; I. M. Watson; M. D. Dawson; G. McConnell; A. M. Gurney

2004-01-01

413

Application of Infrared-Attenuated Total Reflection Technique Combined with Sedimentation Phenomena to Particle Size Measurement: Fundamental Experiments on Applicability of the Method  

NASA Astrophysics Data System (ADS)

A new method using infrared attenuated total reflection (IR-ATR) spectroscopy and sedimentation of particles in a suspension was proposed for particle size measurement. The time dependence of the IR-ATR signal intensity for mono-size dispersed particles agreed qualitatively with the theoretical expectation. Content analyses of samples containing dispersed particles of two sizes gave values close to actual ones. The possibility of size distribution analysis was shown.

Sarno, B. J.; Yoshidome, T.; Ikuta, Y.; Rabor, J. B.; Tsurumura, Y.; Montecillo, M. E.; Higo, M.

2013-09-01

414

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

415

Evaluation of optical reflectance techniques for imaging of alveolar structure.  

PubMed

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. PMID:22894464

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

2012-07-01

416

RAPIDLY WAVELENGTH-TUNABLE ULTRAVIOLET LASER SOURCE FOR CONFOCAL MICROSCOPY  

Microsoft Academic Search

When imaging live cells and tissues in confocal laser scanning microscopy (CLSM), great care must be taken to minimize the risk of photo-induced damage. Judicious choice of the laser wavelength used for excitation can, to a large extent, overcome this problem. By only providing the optimum wavelength required for excitation of fluorescence from the sample under investigation, unnecessary thermal loading

Elric Esposito; John Harris; Gail McConnell

2006-01-01

417

Fiber-based confocal microscope for cryogenic spectroscopy  

Microsoft Academic Search

We describe the design and performance of a fiber-based confocal microscope for cryogenic operation. The microscope combines positioning at low temperatures along three space coordinates of millimeter translation and nanometer precision with high stability and optical performance at the diffraction limit. It was successfully tested under ambient conditions as well as at liquid nitrogen (77 K) and liquid helium (4

Alexander Högele; Stefan Seidl; Martin Kroner; Khaled Karrai; Christian Schulhauser; Omar Sqalli; Jan Scrimgeour; Richard J. Warburton

2008-01-01

418

Feasibility of digitally stained multimodal confocal mosaics to simulate histopathology  

Microsoft Academic Search

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.

Daniel S. Gareau

2009-01-01

419

In vivo confocal microscopy of the human cornea  

PubMed Central

Aims: To describe the optics of in vivo confocal microscopy, its advantages over previous methods, and to summarise the literature that arose from its use for the observation of the human cornea. A critical review of the clinical usefulness of this new technology for the corneal examination is undertaken. Methods: Confocal microscopes obtain increased resolution by limiting the illumination and observation systems to a single point. Rapid scanning is used to reconstruct a full field of view and allows for “real time” viewing. Results: Coronal sections of the in situ epithelium, Bowman’s membrane, stroma, and endothelium can be visualised at a resolution of 1–2 ?m. A backscattered light intensity curve allows objective measurements of sublayer thickness and corneal haze to be taken. In vivo confocal microscopy is therefore particularly useful in the areas of infective keratitis, corneal dystrophies, refractive surgery, and contact lens wear, where it aids in differential diagnosis and detection of subtle short and long term changes. Real time endothelial cell assessment can also be performed. Conclusion: Because of their ability to visualise living tissue at cellular levels, confocal microscopes have proved useful additions to the current clinical tools.

Jalbert, I; Stapleton, F; Papas, E; Sweeney, D F; Coroneo, M

2003-01-01

420

Polarimetric high-resolution confocal scanning laser ophthalmoscope  

Microsoft Academic Search

A polarimetric high-resolution confocal scanning laser ophthalmoscope has been developed. The system incorporates a fixed linear polarizer in the illumination path and a rotatory quarter-wave plate and another fixed linear polarizer in the registration path. Retinal areas that are smaller than those provided by commercial instruments can be imaged. Series of four fundus images for independent polarization states in the

Juan M. Bueno; Brian Vohnsen

2005-01-01

421

Laser excited confocal microscope fluorescence scanner and method  

DOEpatents

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

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

1992-01-01

422

Polyamide membrane precipitation studied by confocal backscattering microscopy  

Microsoft Academic Search

A wide variety of commercial polymeric membranes are manufactured by a non-solvent immersion precipitation process, yet the detailed mechanism and kinetics of membrane formation are poorly understood. We have used a confocal microscope, with fluorescence filters removed, to observe backscatter from precipitating nylon 6 films. Nylon 6 in formic acid\\/water solutions was spread on a glass substrate, which was then

James L. Thomas; Martina Olzog; Christin Drake; Chien-Hsieh Shih; Carl C. Gryte

2002-01-01

423

Optical inspection and characterization of microoptics using confocal microscopy  

Microsoft Academic Search

With the growing demand for microoptics in different areas the importance of the characterization increases. Methods for a fast defect detection in microlens arrays are developed. We present a technique where the confocal principle is applied for determining the variation and the absolute value of the focal length. Additionally, using a self–filtering method the deviation of the periodic structure of

H. J. Tiziani; T. Haist; S. Reuter

2001-01-01

424

The Cornea in Sjogren's Syndrome: An In Vivo Confocal Study  

Microsoft Academic Search

PURPOSE. To analyze the in vivo morphology of corneal cells and nerves in dry eye associated with primary (SSI) and sec- ondary (SSII) Sjogren's syndrome and to study its relationship with the clinical evaluation. METHODS. Thirty-five patients with SS and 20 age- and gender- matched control subjects were studied. Confocal microscopy was used to investigate corneal thickness, epithelial and stro-

Edoardo Villani; Daniela Galimberti; Francesco Viola; Chiara Mapelli; Roberto Ratiglia

425

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

426

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

427

Confirmation of onychomycosis by in vivo confocal microscopy  

Microsoft Academic Search

Onychomycosis is common in adults and constitutes 20% of all nail disease. Widely used methods to confirm a clinical diagnosis of onychomycosis often yield negative results (ie, potassium hydroxide [KOH] preparation) or are slow (ie, dermatophyte cultures). We report a case of onychomycosis in which we used in vivo confocal microscopy to diagnose the disease; we also correlated our findings

Wichai Hongcharu; Peter Dwyer; Salvador Gonzalez; R. Rox Anderson

2000-01-01

428

Confocal Imaging of Microglial Cell Dynamics in Hippocampal Slice Cultures  

Microsoft Academic Search

Methods are described for imaging the cellular dynamics of microglia in live mammalian brain slice cultures. Brain slices prepared from developing rat hippocampus are cultured for up to 2 weeks by the roller tube or static filter culture technique, stained with one or more fluorescent dyes, and imaged by scanning laser confocal microscopy. One of several cell type-specific or nonspecific

Michael E. Dailey; Marc Waite

1999-01-01

429

Extubation reflectivity.  

PubMed

The purpose of this article is to share a recovery room practitioner's experience using reflection and to explore the issues surrounding extubation in the post anaesthetic care unit (PACU). Currently there are no national standards of practice for practitioners' learning and safe practice of extubation techniques within the PACU. Therefore, the possibility of an adverse incident is significantly increased, potentially causing harm to the patient and damage to any hospital's reputation as well as the practitioners' profession. The authors wish to identify the concerns by citing a clinical incident that lead to reflection and sharing of the experience through this article. PMID:18201030

Mason, Paula; Hardy, Dawn; Smith, Brian

2007-12-01

430

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

Microsoft Academic Search

Applications of seismic travel time tomography are restricted for the most part either to the direct wave or to 2D. Based on the SIMULPS13Q version (Rietbrock, 1996) of the wide-spread SIMUL-code-family and the concepts of flexible gridding (Thurber, 1983-1999) we developed a simultaneous 3D inversion for slowness and reflector depth. The tomographic algorithm is based on an irregular model parametrization

F. Bleibinhaus; H. Gebrande

2003-01-01

431

Application of asymptotic radiative transfer theory for the retrievals of snow parameters using reflection and transmission observations  

NASA Astrophysics Data System (ADS)

An asymptotic analytical radiative transfer (AART) theory was used to retrieve snow optical parameters such as extinction coefficient, diffuse exponent, asymptotic flux extinction coefficient (AFEC), snow optical thickness and probability of photon absorption (PPA). This theory was applied to the reflection and transmission data for a temperate snow cover from 400-1000 nm wavelength region, to retrieve AFEC for different types of snow cover (thick, thin, dry, wet, new and old snow). The AFEC values were found at 450 nm wavelength region in the range from 0.06 to 0.22 cm-1, where high values were observed for increased wetness and impurity in snow. A good agreement between AART retrieved and other radiative transfer model retrieved parameter shows that AART theory can work well for different types of snow. The extinction coefficients for temperate snow ranged from 0.5 to 1.0 mm-1 and the e-folding depths ranged from 5 to 25 cm. The snow physical characteristics such as grain size and density were also retrieved using derived optical parameters and found in agreement with ground measurements. The main advantages of the proposed AART method are the simple analytical equations that provide a valuable alternative from complex numerical radiative transfer solutions.

Negi, H. S.; Kokhanovsky, A.; Perovich, D. K.

2011-04-01

432

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

2013-02-05

433

Relaxation of sound fields in rooms of diffusely reflecting boundaries and its application in acoustical radiosity simulation.  

PubMed

The acoustical radiosity method is a computationally expensive acoustical simulation algorithm that assumes an enclosure with ideal diffuse reflecting boundaries. Miles observed that for such an enclosure, the sound energy decay of every point on the boundaries will gradually converge to exponential manner with a uniform decay rate. Therefore, the ratio of radiosity between every pair of points on the boundaries will converge to a constant, and the radiosity across the boundaries will approach a fixed distribution during the sound decay process, where radiosity is defined as the acoustic power per unit area leaving (or being received by) a point on a boundary. We call this phenomenon the "relaxation" of the sound field. In this paper, we study the relaxation in rooms of different shapes with different boundary absorptions. Criteria based on the relaxation of the sound field are proposed to terminate the costly and unnecessary radiosity computation in the later phase, which can then be replaced by a fast regression step to speed up the acoustical radiosity simulation. PMID:16642833

Zhang, Honghu

2006-04-01