These are representative sample records from Science.gov related to your search topic.
For comprehensive and current results, perform a real-time search at Science.gov.
1

Anal melanosis diagnosed by reflectance confocal microscopy.  

PubMed

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

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

2014-11-01

2

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

PubMed Central

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

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

2012-01-01

3

Single-wavelength reflected confocal and multiphoton microscopy for tissue imaging  

E-print Network

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

So, Peter T. C.

4

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.

2011-03-01

5

Spectral confocal reflection microscopy using a white light source  

NASA Astrophysics Data System (ADS)

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

Booth, M.; Juškaitis, R.; Wilson, T.

2008-08-01

6

FOOD SURFACE TEXTURE MEASUREMENT USING REFLECTIVE CONFOCAL LASER SCANNING MICROSCOPY  

Technology Transfer Automated Retrieval System (TEKTRAN)

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

7

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

8

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

9

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

NASA Astrophysics Data System (ADS)

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

Yang, Yong-fa; Li, Qi

2014-12-01

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. PMID:21994069

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

2013-01-01

11

Distinct melanoma types based on reflectance confocal microscopy.  

PubMed

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

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

2014-06-01

12

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

13

Combined FLIM and reflectance confocal microscopy for epithelial imaging  

NASA Astrophysics Data System (ADS)

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

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

2012-03-01

14

Dual-axes confocal reflectance microscope for distinguishing colonic neoplasia  

PubMed Central

A dual-axes confocal reflectance microscope has been developed that utilizes a narrowband laser at 1310 nm to achieve high axial resolution, image contrast, field of view, and tissue penetration for distinguishing among normal, hyperplastic, and dysplastic colonic mucosa ex vivo. Light is collected off-axis using a low numerical aperture objective to obtain vertical image sections, with 4- to 5-?m resolution, at tissue depths up to 610 ?m. Post-objective scanning enables a large field of view (610 × 640 ?m), and balanced-heterodyne detection provides sensitivity to collect vertical sections at one frame per second. System optics are optimized to effectively reject out-of-focus scattered light without use of a low-coherence gate. This design is scalable to millimeter dimensions, and the results demonstrate the potential for a miniature instrument to detect precancerous tissues, and hence to perform in vivo histopathology. PMID:17092168

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

2007-01-01

15

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

PubMed Central

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

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

2014-01-01

16

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

NASA Astrophysics Data System (ADS)

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

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

2014-12-01

17

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

PubMed Central

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

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

2014-01-01

18

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

PubMed

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

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

2015-01-15

19

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

PubMed

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

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

2014-11-01

20

Single-wavelength reflected confocal and multiphoton microscopy for tissue imaging  

NASA Astrophysics Data System (ADS)

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

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

2009-09-01

21

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

PubMed Central

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

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

2013-01-01

22

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

PubMed Central

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

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

2013-01-01

23

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

NASA Astrophysics Data System (ADS)

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

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

2006-07-01

24

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

PubMed

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

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

2013-05-01

25

Combining total internal reflection sum frequency spectroscopy spectral imaging and confocal fluorescence microscopy.  

PubMed

Understanding surface and interfacial lateral organization in material and biological systems is critical in nearly every field of science. The continued development of tools and techniques viable for elucidation of interfacial and surface information is therefore necessary to address new questions and further current investigations. Sum frequency spectroscopy (SFS) is a label-free, nonlinear optical technique with inherent surface specificity that can yield critical organizational information on interfacial species. Unfortunately, SFS provides no spatial information on a surface; small scale heterogeneities that may exist are averaged over the large areas typically probed. Over the past decade, this has begun to be addressed with the advent of SFS microscopy. Here we detail the construction and function of a total internal reflection (TIR) SFS spectral and confocal fluorescence imaging microscope directly amenable to surface investigations. This instrument combines, for the first time, sample scanning TIR-SFS imaging with confocal fluorescence microscopy. PMID:25506739

Allgeyer, Edward S; Sterling, Sarah M; Gunewardene, Mudalige S; Hess, Samuel T; Neivandt, David J; Mason, Michael D

2015-01-27

26

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

27

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

28

Dermoscopy, Reflectance Confocal Microscopy and Immunohistochemical Analysis in Melanocytic Lesions with Meyerson's Phenomenon.  

PubMed

Background: Meyerson's phenomenon is characterized by a symmetrical halo of erythema and scale around central, mostly melanocytic lesions. Objective: Our aim was to describe the dermoscopic and reflectance confocal microscopy (RCM) features of melanocytic tumors less frequently associated with Meyerson's phenomenon, with histopathology and immunohistochemistry correlation. Methods: Clinical, dermoscopic and RCM images of 4 histopathologically confirmed melanocytic tumors associated with Meyerson's phenomenon (3 dysplastic compound nevi and 1 melanoma) were retrospectively collected, with additional immunohistochemical analysis. Results: RCM showed in vivo features of both melanocytic and spongiotic nature of the lesion associated with Meyerson's phenomenon, even in cases with absent halo. Our study also supported the involvement of immune-mediated CD4+ T lymphocyte mechanisms and Langerhans cells. Conclusion: Our case series supports the potential of RCM in the evaluation of tumoral and inflammatory skin diseases. RCM features of rare Meyerson's melanoma were also described for the first time. © 2014 S. Karger AG, Basel. PMID:25472722

Oliveira, André; Arzberger, Edith; Massone, Cesare; Fink-Puches, Regina; Zalaudek, Iris; Hofmann-Wellenhof, Rainer

2014-11-27

29

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

30

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

PubMed

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

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

2015-03-01

31

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

NASA Astrophysics Data System (ADS)

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

Sugata, Keiichi; Osanai, Osamu; Kawada, Hiromitsu

2012-02-01

32

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

PubMed Central

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

Chen, Guannan; Lui, Harvey

2015-01-01

33

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

PubMed Central

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

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

2007-01-01

34

Reflectance and Fluorescence Confocal Microscope for Imaging of the Mouse Colon  

E-print Network

................................................................................... 2 2. BACKGROUND ................................................................................................. 4 2.1 Inflammation and Colorectal Cancer ................................................... 4 2.2 Confocal Microscopy... of Biomedical Optics Express. 1. INTRODUCTION 1.1 Motivation Those experiencing ulcerative colitis or Crohn?s disease have an increased risk for developing colorectal cancer; therefore, there is an assumption that chronic inflammation causes cancer [1...

Saldua, Meagan Alyssa

2012-02-14

35

Systematic review of diagnostic accuracy of reflectance confocal microscopy for melanoma diagnosis in patients with clinically equivocal skin lesions  

PubMed Central

Background: Melanoma is a cancer of the skin and is increasing in incidence in the UK and Europe. Melanoma is a condition that is often curable if detected at an early stage, which makes accurate diagnosis vital. Reflectance confocal microscopy (RCM) is a tool used to image the skin. It gives high magnification images of the skin, which may provide more accurate diagnosis of lesions that are equivocal on clinical examination and dermoscopy. Objective: To determine the diagnostic accuracy of reflectance confocal microscopy (RCM), for melanoma diagnosis, as an add-on test to clinical examination and dermoscopy in the diagnosis of equivocal pigmented skin lesions using histopathology as the reference standard. Methods: A search was conducted of MEDLINE, EMBASE and six other electronic databases from inception to present. Forward citation searching and hand searching of reference lists were also conducted. Diagnostic accuracy studies that assess RCM in the diagnosis of melanoma were included in the review. Two contributors conducted the search, data extraction and assessment of methodological quality using QUADAS-2. Statistical analysis was performed using hierarchical bivariate random effects meta-analysis. Results: 951 titles and abstracts were screened. Five studies comprising 909 lesions were eligible for meta-analysis. Meta-analysis returned a per lesion sensitivity of 93% [95% CI 89–96] and a specificity of 76% [95% CI 68–83]. Conclusions: The utility of reflectance confocal microscopy (RCM) as an add-on test for the diagnosis of melanoma depends on the trade off between over-excising benign lesions and misdiagnosing melanoma as benign. This becomes important when considering lesions on surgically difficult or cosmetically important areas of the body. PMID:24282659

Stevenson, Alexander D.; Mickan, Sharon; Mallett, Susan; Ayya, Mekhala

2013-01-01

36

Comparison of Reflectance Confocal Microscopy and Standardized skin surface biopsy for three different lesions in a pityriasis folliculorum patient.  

PubMed

Pityriasis folliculorum(1) (PF) is a human demodicosis proposed as "primary", caused by the proliferation of Demodex folliculorum (D):(2) it consists of very small, discrete and regularly dispersed follicular scales, involving sebaceous hair follicles, often without visible inflammation. Patients can complain about pruritus, dry, sensitive, irregular or rough skin.(1) Forton et al(3) report that PF is the most frequent demodicosis (54%) compared with papulopustular rosacea, and has a higher demodex density (Dd) (D=61/cm(2) , n=45) tested by "Standardized skin surface biopsy (SSSB)". However, Reflectance Confocal Microscopy (RCM) now shows promising results.(4) This article is protected by copyright. All rights reserved. PMID:25363861

Yuan, C; Wang, X-M; Guichard, A; Lihoreau, T; Sophie, M-M; Lamia, K; Ardigò, M; Humbert, P

2014-10-31

37

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

38

[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

39

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

Microsoft Academic Search

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 micro- scope for in vivo imaging of cells and tissue. Changing the spacing and rotation of the individual

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

2006-01-01

40

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

Microsoft Academic Search

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

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

2006-01-01

41

Application of confocal laser microscopy for monitoring mesh implants in herniology  

SciTech Connect

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

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

2011-04-30

42

Pilot study of semiautomated localization of the dermal?epidermal junction in reflectance confocal microscopy images of skin  

PubMed Central

Reflectance confocal microscopy (RCM) continues to be translated toward the detection of skin cancers in vivo. Automated image analysis may help clinicians and accelerate clinical acceptance of RCM. For screening and diagnosis of cancer, the dermal?epidermal junction (DEJ), at which melanomas and basal cell carcinomas originate, is an important feature in skin. In RCM images, the DEJ is marked by optically subtle changes and features and is difficult to detect purely by visual examination. Challenges for automation of DEJ detection include heterogeneity of skin tissue, high inter-, intra-subject variability, and low optical contrast. To cope with these challenges, we propose a semiautomated hybrid sequence segmentation?classification algorithm that partitions z-stacks of tiles into homogeneous segments by fitting a model of skin layer dynamics and then classifies tile segments as epidermis, dermis, or transitional DEJ region using texture features. We evaluate two different training scenarios: 1. training and testing on portions of the same stack; 2. training on one labeled stack and testing on one from a different subject with similar skin type. Initial results demonstrate the detectability of the DEJ in both scenarios with epidermis?dermis misclassification rates smaller than 10% and average distance from the expert labeled boundaries around 8.5 ?m. PMID:21456869

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

2011-01-01

43

Confocal microendoscopy with chromatic sectioning  

NASA Astrophysics Data System (ADS)

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

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

2003-07-01

44

Treatment monitoring of topical ingenol mebutate in actinic keratoses with the combination of optical coherence tomography and reflectance confocal microscopy: a case series.  

PubMed

ingenol mebutate gel has been approved lately for the topical treatment of actinic keratoses (AK). Modern imaging techniques such as optical coherence tomography (OCT) and reflectance confocal microscopy (RCM) have been shown useful for the non-invasive diagnostics of non-melanoma skin cancer(1-6) . Both techniques differ in optical resolution and penetration depth. This article is protected by copyright. All rights reserved. PMID:25070046

Maier, T; Cekovic, D; Ruzicka, T; Sattler, E; Berking, C

2014-07-28

45

Semi-automated Algorithm for Localization of Dermal/ Epidermal Junction in Reflectance Confocal Microscopy Images of Human Skin.  

PubMed

The examination of the dermis/epidermis junction (DEJ) is clinically important for skin cancer diagnosis. Reflectance confocal microscopy (RCM) is an emerging tool for detection of skin cancers in vivo. However, visual localization of the DEJ in RCM images, with high accuracy and repeatability, is challenging, especially in fair skin, due to low contrast, heterogeneous structure and high inter- and intra-subject variability. We recently proposed a semi-automated algorithm to localize the DEJ in z-stacks of RCM images of fair skin, based on feature segmentation and classification. Here we extend the algorithm to dark skin. The extended algorithm first decides the skin type and then applies the appropriate DEJ localization method. In dark skin, strong backscatter from the pigment melanin causes the basal cells above the DEJ to appear with high contrast. To locate those high contrast regions, the algorithm operates on small tiles (regions) and finds the peaks of the smoothed average intensity depth profile of each tile. However, for some tiles, due to heterogeneity, multiple peaks in the depth profile exist and the strongest peak might not be the basal layer peak. To select the correct peak, basal cells are represented with a vector of texture features. The peak with most similar features to this feature vector is selected. The results show that the algorithm detected the skin types correctly for all 17 stacks tested (8 fair, 9 dark). The DEJ detection algorithm achieved an average distance from the ground truth DEJ surface of around 4.7?m for dark skin and around 7-14?m for fair skin. PMID:21709746

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

2011-01-01

46

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

PubMed

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

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

2013-03-01

47

Application of confocal X-ray fluorescence micro-spectroscopy to the investigation of paint layers.  

PubMed

A confocal micro X-ray fluorescence (MXRF) spectrometer based on polycapillary X-ray optics was used for the identification of paint layers. The performance of the confocal MXRF was studied. Multilayered paint fragments of a car were analyzed nondestructively to demonstrate that this confocal MXRF instrument could be used in the discrimination of the various layers in multilayer paint systems. PMID:25151613

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

2014-12-01

48

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

49

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

50

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

NASA Astrophysics Data System (ADS)

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

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

2012-02-01

51

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

PubMed Central

Background: The clinical application of fluorescent contrast agents (fluorescein, indocyanine green, and aminolevulinic acid) with intraoperative microscopy has led to advances in intraoperative brain tumor imaging. Their properties, mechanism of action, history of use, and safety are analyzed in this report along with a review of current laser scanning confocal endomicroscopy systems. Additional imaging modalities with potential neurosurgical utility are also analyzed. Methods: A comprehensive literature search was performed utilizing PubMed and key words: In vivo confocal microscopy, confocal endomicroscopy, fluorescence imaging, in vivo diagnostics/neoplasm, in vivo molecular imaging, and optical imaging. Articles were reviewed that discussed clinically available fluorophores in neurosurgery, confocal endomicroscopy instrumentation, confocal microscopy systems, and intraoperative cancer diagnostics. Results: Current clinically available fluorescent contrast agents have specific properties that provide microscopic delineation of tumors when imaged with laser scanning confocal endomicroscopes. Other imaging modalities such as coherent anti-Stokes Raman scattering (CARS) microscopy, confocal reflectance microscopy, fluorescent lifetime imaging (FLIM), two-photon microscopy, and second harmonic generation may also have potential in neurosurgical applications. Conclusion: In addition to guiding tumor resection, intraoperative fluorescence and microscopy have the potential to facilitate tumor identification and complement frozen section analysis during surgery by providing real-time histological assessment. Further research, including clinical trials, is necessary to test the efficacy of fluorescent contrast agents and optical imaging instrumentation in order to establish their role in neurosurgery. PMID:24872922

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

2014-01-01

52

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

Microsoft Academic Search

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

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

2010-01-01

53

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

NASA Astrophysics Data System (ADS)

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

Han, Wenfeng; Xiao, Zexin; Wang, Xiaofen

2009-11-01

54

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

Microsoft Academic Search

Confocal laser scanning microscopy (CLSM) allows noninvasive visualization of human skin in vivo, without needing to fix or\\u000a section the tissue. Melanocytes and pigmented keratinocytes at the level of the basal layer form bright dermal papillary rings\\u000a which are readily amenable to identify in confocal images. Our purpose was to explore the role of dermal papillary rings in\\u000a assessment of

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

2010-01-01

55

Forest reflectance modeling: theoretical aspects and applications.  

PubMed

Forest reflectance models are able to contribute to the interpretation of satellite images over forested areas. A multipurpose forest reflectance model, its basic ideas, model input and output options are briefly described. The possibility to apply the model in forest remote sensing is demonstrated through the following simulation examples: the age dependence of forest reflectance, the seasonal course of forest reflectance, defoliation effects on forest reflectance, sensitivity of chlorophyll and water indices with respect to leaf chlorophyll and water content, respectively, and uncertainties in these indices introduced by the variation in stand parameters. When used together with the atmospheric radiative transfer and sensor calibration models, the forest reflectance model is applicable in satellite-imagery-aided forest ecology and health assessment, forest inventory and management. PMID:15049350

Nilson, Tiit; Kuusk, Andres; Lang, Mait; Lukk, Tõnu

2003-12-01

56

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

EPA Science Inventory

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

57

Scanning computed confocal imager  

DOEpatents

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

George, John S. (Los Alamos, NM)

2000-03-14

58

Application of confocal microscopy for surface and volume imaging of solid state nuclear track detectors.  

PubMed

Inhalation of radon gas is considered a risk factor in the development of lung cancer. Solid state nuclear track detectors (SSNTDs) are often used for monitoring radon levels. We have previously shown that 3D imaging can help distinguish real tracks from artefact. In this study, we investigated particle tracks in nine SSNTDs using surface and volume visualisation from confocal microscope imaging. An Olympus LEXT OLS 4000 confocal microscope equipped with the Olympus LEXT Remote Development Kit was used to acquire z-stack images and surface data from the SSNTDs. Surface and volume visualisation analysis methods were developed and applied to examine the data. The mean (standard deviation) depth of 45 tracks from the nine detectors was 9.5 (4.6) ?m. The mean difference in track depth using the two analysis techniques was 0.08 ?m, thus showing good agreement. Furthermore, volume visualisation should enable assessment of the structure of tracks deep in the detector. PMID:24502352

Wertheim, D; Gillmore, G

2014-04-01

59

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. PMID:21323670

Laasmaa, M; Vendelin, M; Peterson, P

2011-01-01

60

Broadband reflectance coatings for vacuum ultraviolet application  

NASA Technical Reports Server (NTRS)

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

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

1987-01-01

61

Investigation of the confocal wavefront sensor and its application to biological microscopy.  

PubMed

Wavefront sensing in the presence of background light sources is complicated by the need to restrict the effective depth of field of the wavefront sensor. This problem is particularly significant in direct wavefront sensing adaptive optic (AO) schemes for correcting imaging aberrations in biological microscopy. In this paper we investigate how a confocal pinhole can be used to reject out of focus light whilst still allowing effective wavefront sensing. Using a scaled set of phase screens with statistical properties derived from measurements of wavefront aberrations induced by C. elegans specimens, we investigate and quantify how the size of the pinhole and the aberration amplitude affect the transmitted wavefront. We suggest a lower bound for the pinhole size for a given aberration strength and quantify the optical sectioning provided by the system. For our measured aberration data we find that a pinhole of size approximately 3 Airy units represents a good compromise, allowing effective transmission of the wavefront and thin optical sections. Finally, we discuss some of the practical implications of confocal wavefront sensing for AO systems in microscopy. PMID:23938851

Shaw, Michael; O'Holleran, Kevin; Paterson, Carl

2013-08-12

62

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

PubMed Central

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

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

2013-01-01

63

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

NASA Astrophysics Data System (ADS)

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.

2013-08-01

64

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

2013-01-01

65

The Application of Confocal Microscopy and Particle Size Analysis to Cartridge Case Examinations  

NASA Astrophysics Data System (ADS)

Although cross-correlation analysis is a convenient tool for image comparison, research shows that cross-correlation analysis of surface topographies is incapable of distinguishing between the large numbers of cartridge cases that would be necessary to create a national database. In this study, we manually overlay confocal images of primer face impressions and show that the size distribution of the regions of correspondence between two impressions has the potential to significantly improve the number of discernible topographies. Our results indicate that the average area of the individual regions of correspondence in an overlay provides a more abrupt distinction between matching and non-matching cartridge cases than does the overall extent of correspondence. In the 1950s, Biasotti discovered a similar trend in bullets, noting that the number of consecutive matching striae never exceed a particular number for non-matching bullets.

McClorry, Shannon

66

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

PubMed Central

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

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

2013-01-01

67

The Application of in vivo laser scanning confocal microscopy as a tool of conjunctival in vivo cytology in the diagnosis of dry eye ocular surface disease  

PubMed Central

Purpose To evaluate the applicability of in vivo laser scanning confocal microscopy as a tool of conjunctival cytology in a prospective case-control study. Methods Nineteen right eyes of 19 Sjogren’s syndrome dry eye patients (19 females; mean age: 55.8±15 years), and 18 right eyes of 18 normal healthy control subjects (12 females and 6 males; mean age: 50.8±14 years) were evaluated in this study. The eyes were analyzed by the Heidelberg retina tomography (HRTII)/Rostock cornea module (RCM). Ocular surface and tear function tests including vital stainings (fluorescein and Rose Bengal), Schirmer test, tear film break up time (BUT), and conjunctival impression cytology were performed. After obtaining the confocal microscopy images, the mean individual epithelial cell area (MIECA), and nucleocytoplasmic (N/C) ratio were analyzed. The correlation between confocal microscopy and impression cytology parameters was also investigated. Results The BUT, Schirmer test values, vital staining scores and squamous metaplasia grades in impression cytology were significantly worse in dry eye patients compared to controls (p<0.0001). The MIECA and the mean N/C ratios were worse in dry eye subjects compared to controls both in impression cytology and in vivo confocal microscopy (p<0.0001) with no significant differences between these parameters when the two examination techniques were compared. The MIECA and N/C ratio in conjunctival impression cytology showed significant correlation with the corresponding confocal microscopy parameters (MIECA, r2:0.557 ; N/C, r2:0.765). Conclusions Laser scanning confocal microscopy seems to be an efficient non-invasive tool in the evaluation of phenotypic alterations of the conjunctival epithelium in dry eye disease. N/C ratio and MIECA appear to be two promising and new parameters of in vivo confocal cytology in the assessment of the ocular surface in dry eye disease. PMID:21139693

Kojima, Takashi; Matsumoto, Yukihiro; Tsubota, Kazuo

2010-01-01

68

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

NASA Astrophysics Data System (ADS)

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

Kuypers, Liesbeth

2005-11-01

69

A laser scanning confocal imaging-surface plasmon resonance system application in real time detection of antibody-antigen interaction  

NASA Astrophysics Data System (ADS)

The laser scanning confocal microscope (LSCM) offers several advantages over conventional optical microscopy, but most LSCM work is qualitative analysis and it is very hard to achieve quantitative detection directly with the changing of the fluorescent intensity. A new real time sensor system for the antibody-antigen interaction detection was built integrating with a LSCM and a wavelength-dependent surface plasmon resonance (SPR) sensor. The system was applied to detect the bonding process of human IgG and fluorescent-labeled affinity purified antibody in real time. The fluorescence images changing is well with that of SPR wavelengths in real time, and the trend of the resonance wavelength shift with the concentrations of antibody is similar to that of the fluorescent intensity changing. The results show that SPR makes up the short of quantificational analysis with LSCM with the high spatial resolution. The sensor system shows the merits of the of the LSCM and SPR synergetic application, which are of great importance for practical application in biosensor and life science for interesting local interaction.

Zhang, H. Y.; Yang, L. Q.; Liu, W. M.

2011-12-01

70

The Oberon2 Reflection Model and its Applications  

E-print Network

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

Mössenböck, Hanspeter

71

Video-rate scanning confocal microscopy and microendoscopy.  

PubMed

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 targets, monitor dynamics in living cells, and visualize the three dimensional evolution of entire organisms. Extensions of confocal imaging systems, such as confocal microendoscopes, allow for high-resolution imaging in vivo and are currently being applied to disease imaging and diagnosis in clinical settings. 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 pinhole, creating an optical section in which only light from the microscope focus is visible. (Fig 1). Thus the pinhole effectively acts as a virtual aperture in the focal plane, confining the detected emission to only one limited spatial location. Modern commercial confocal microscopes offer users fully automated operation, making formerly complex imaging procedures relatively straightforward and accessible. Despite the flexibility and power of these systems, commercial confocal microscopes are not well suited for all confocal imaging tasks, such as many in vivo imaging applications. Without the ability to create customized imaging systems to meet their needs, important experiments can remain out of reach to many scientists. In this article, we provide a step-by-step method for the complete construction of a custom, video-rate confocal imaging system from basic components. The upright microscope will be constructed using a resonant galvanometric mirror to provide the fast scanning axis, while a standard speed resonant galvanometric mirror will scan the slow axis. To create a precise scanned beam in the objective lens focus, these mirrors will be positioned at the so-called telecentric planes using four relay lenses. Confocal detection will be accomplished using a standard, off-the-shelf photomultiplier tube (PMT), and the images will be captured and displayed using a Matrox framegrabber card and the included software. PMID:22042305

Nichols, Alexander J; Evans, Conor L

2011-01-01

72

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

73

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

74

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

75

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

NASA Astrophysics Data System (ADS)

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

Masters, Barry R.

1995-05-01

76

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

77

Confocal microscopy on the Internet.  

PubMed

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

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

2014-01-01

78

Applicability of highly reflective aluminium coil for solar concentrators  

Microsoft Academic Search

Because of their manufacturing flexibility and their low costs, mirrors based on anodized or coated sheet aluminium are a promising alternative as primary or secondary concentrators in a number of solar energy applications. They offer solar weighted reflectances of 88–91%, good mechanical properties and are easy to recycle. However, problems occur due to their limited corrosion resistance. Therefore, prior to

Thomas Fend; Gary Jorgensen; Harald Küster

2000-01-01

79

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

80

Reflections  

NSDL National Science Digital Library

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

Carlyn Little

1997-01-01

81

Spectral reflectance of selected aqueous solutions for water quality applications  

NASA Technical Reports Server (NTRS)

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

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

1972-01-01

82

Reflectance of metallic indium for solar energy applications  

NASA Technical Reports Server (NTRS)

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

Bouquet, F. L.; Hasegawa, T.

1984-01-01

83

High-speed multispectral confocal biomedical imaging.  

PubMed

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

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

2014-03-01

84

Flow cytometry using spectrally encoded confocal microscopy.  

PubMed

Flow cytometry techniques often rely on detecting fluorescence from single cells flowing through the cross section of a laser beam, providing invaluable information on vast numbers of cells. Such techniques, however, are often limited in their ability to resolve clusters of cells or parallel cell flow through large vessels. We present a confocal imaging technique that images unstained cells flowing in parallel through a wide channel, using spectrally encoded reflectance confocal microscopy that does not require mechanical scanning. Images of red blood cells from our system are compared to conventional transmission microscopy, and imaging of flowing red blood cells in vitro is experimentally demonstrated. PMID:20596199

Golan, Lior; Yelin, Dvir

2010-07-01

85

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

PubMed

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

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

1995-02-01

86

Re-scan confocal microscopy: scanning twice for better resolution  

PubMed Central

We present a new super-resolution technique, Re-scan Confocal Microscopy (RCM), based on standard confocal microscopy extended with an optical (re-scanning) unit that projects the image directly on a CCD-camera. This new microscope has improved lateral resolution and strongly improved sensitivity while maintaining the sectioning capability of a standard confocal microscope. This simple technology is typically useful for biological applications where the combination high-resolution and high-sensitivity is required. PMID:24298422

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

2013-01-01

87

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

88

Multimodal confocal hyperspectral imaging microscopy with wavelength sweeping source  

NASA Astrophysics Data System (ADS)

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

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

2015-02-01

89

A miniature confocal optical scanning microscope for endoscopes  

Microsoft Academic Search

We have developed a unique miniature confocal optical scanning microscope as an endoscopic application and successfully obtained a real time image. The confocal microscope can observe the longitudinal direction of a scanning head including the electrostatic 2-D MEMS scanner and an aspherical objective lens. Waterproof packaging of the scanning head is accomplished. The MEMS scanner and the objective lens in

Kenzi Murakami

2005-01-01

90

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

91

Bidirectional Reflectance Functions for Application to Earth Radiation Budget Studies  

NASA Technical Reports Server (NTRS)

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

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

1997-01-01

92

Comprehensive volumetric confocal microscopy with adaptive focusing  

PubMed Central

Comprehensive microscopy of distal esophagus could greatly improve the screening and surveillance of esophageal diseases such as Barrett’s esophagus by providing histomorphologic information over the entire region at risk. Spectrally encoded confocal microscopy (SECM) is a high-speed reflectance confocal microscopy technology that can be configured to image the entire distal esophagus by helically scanning the beam using optics within a balloon-centering probe. It is challenging to image the human esophagus in vivo with balloon-based SECM, however, because patient motion and anatomic tissue surface irregularities decenter the optics, making it difficult to keep the focus at a predetermined location within the tissue as the beam is scanned. In this paper, we present a SECM probe equipped with an adaptive focusing mechanism that can compensate for tissue surface irregularity and dynamic focal variation. A tilted arrangement of the objective lens is employed in the SECM probe to provide feedback signals to an adaptive focusing mechanism. The tilted configuration also allows the probe to obtain reflectance confocal data from multiple depth levels, enabling the acquisition of three-dimensional volumetric data during a single scan of the probe. A tissue phantom with a surface area of 12.6 cm2 was imaged using the new SECM probe, and 8 large-area reflectance confocal microscopy images were acquired over the depth range of 56 ?m in 20 minutes. Large-area SECM images of excised swine small intestine tissue were also acquired, enabling the visualization of villous architecture, epithelium, and lamina propria. The adaptive focusing mechanism was demonstrated to enable acquisition of in-focus images even when the probe was not centered and the tissue surface was irregular. PMID:21698005

Kang, DongKyun; Yoo, Hongki; Jillella, Priyanka; Bouma, Brett E.; Tearney, Guillermo J.

2011-01-01

93

Applications of microstructured silicon wafers as internal reflection elements in attenuated total reflection Fourier transform infrared spectroscopy.  

PubMed

A novel internal reflection element (IRE) for attenuated total reflection Fourier transform infrared (ATR-FT-IR) spectral acquisition is introduced and applied for several surface-sensitive measurements. It is based on microstructured double-side-polished (100) silicon wafers with v-shaped grooves of {111} facets on their backside. These facets of the so-called "microstructured single-reflection elements" (mSRE) are formed by a crystal-oriented anisotropic wet etching process within a conventional wafer structuring process. They are used to couple infrared radiation into and out of the IRE. In contrast to the application of the commonly used silicon multiple-reflection elements (MRE), the new elements provide single-reflection ATR measurements at the opposite wafer side by using simple reflection accessories without any special collimation. Due to the short light path, the spectral range covers the entire mid-infrared region with a high optical throughput, including the range of silicon lattice vibrations from 300 to 1500 cm(-1). In addition to typical ATR applications, i.e., the measurement of bulk liquids and soft materials, the new reflection elements can be effectively used and customer-specifically designed for in situ and ex situ investigations of aqueous solutions, thin films, and monolayers on Si. Examples presented in this article are in situ etching of native as well as thermal SiO(2) and characterization of polydimethylsiloxane (PDMS) films on Si under various measuring conditions. PMID:20828439

Schumacher, Henrik; Künzelmann, Ulrich; Vasilev, Boris; Eichhorn, Klaus-Jochen; Bartha, Johann W

2010-09-01

94

Confocal Microscopy of Corneal Dystrophies  

PubMed Central

In vivo confocal microscopy (IVCM) of the cornea is becoming an indispensable tool in the cellular study of corneal physiology and disease. This technique offers non-invasive imaging of the living cornea with images comparable to that of ex vivo histology. The ability to provide high-resolution images of all layers in the living cornea has resulted in new discoveries of corneal pathology at the cellular level. The IVCM analysis of corneal dystrophies is of importance to clinicians, as current methods of diagnosis involve slit-lamp characteristics, genetic analysis, and invasive biopsy. IVCM is helpful in evaluating the morphological characteristics of corneal dystrophies at the histological level and may be helpful in diagnosis, determination of progression, and understanding the pathophysiology of disease. The purpose of this review is to describe the principles, applications, and clinical correlation of IVCM in the study of corneal dystrophies. PMID:23163262

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

2014-01-01

95

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

96

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

97

Confocal Endomicroscopy of Colorectal Polyps  

PubMed Central

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

Ussui, Vivian M.; Wallace, Michael B.

2012-01-01

98

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

99

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

100

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

NASA Technical Reports Server (NTRS)

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

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

1994-01-01

101

Assessing asymmetry using reflection and rotoinversion in biomedical engineering applications.  

PubMed

Symmetry is a trait that has been extensively reviewed, especially clinically, as an indication of ideal geometry and health. Many geometric symmetry assessment techniques rely on two-dimensional measurements that do not account for the three-dimensional nature of the object. In this article, two methods, reflection and a process termed rotoinversion, a combination of reflection and rotation, are presented as potential methods to assess an object's deviation from symmetry. With reflection, the geometric models are reflected about a calculated best plane of symmetry. With rotoinversion, the models are reflected about an arbitrary plane and then rigidly translated and rotated to best align the translated and original models. The methods give the same results for bilaterally symmetric objects, but different results for bilaterally and rotationally symmetric objects. The two methods are applied to assess asymmetry in adolescent idiopathic scoliosis torso geometric models, producing similar results. There was an angle of 0.408° between the normal to the plane of reflection from the reflection process and the normal from the rotoinversion process and average rotation of 0.067° from rotoinversion. The most appropriate method depends on the purpose of the symmetry assessment and must be determined on a case-by-case basis. PMID:24727591

Hill, Shannon; Franco-Sepulveda, Esteban; Komeili, Amin; Trovato, Alexandra; Parent, Eric; Hill, Doug; Lou, Edmond; Adeeb, Samer

2014-04-11

102

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

PubMed

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

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

2004-06-01

103

A New Multichannel Spectral Imaging Laser Scanning Confocal Microscope  

PubMed Central

We have developed a new multichannel spectral imaging laser scanning confocal microscope for effective detection of multiple fluorescent labeling in the research of biological tissues. In this paper, the design and key technologies of the system are introduced. Representative results on confocal imaging, 3-dimensional sectioning imaging, and spectral imaging are demonstrated. The results indicated that the system is applicable to multiple fluorescent labeling in biological experiments. PMID:23585775

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

2013-01-01

104

Combined Confocal and Magnetic Resonance Microscopy  

SciTech Connect

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

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

2002-05-12

105

Optical tweezers for confocal microscopy  

NASA Astrophysics Data System (ADS)

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

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

2000-11-01

106

Quantitative confocal phase imaging by synthetic optical holography.  

PubMed

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

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

2014-06-16

107

Laboratory laser reflectance measurement and applications to asteroid surface analysis  

NASA Astrophysics Data System (ADS)

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

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

2014-07-01

108

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

ERIC Educational Resources Information Center

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

Chou, Pao-Nan; Chang, Chi-Cheng

2011-01-01

109

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

110

Reflective cholesteric liquid crystal polarizers and their applications  

Microsoft Academic Search

Various single layer reflective polarizers are introduced based on cholesteric liquid crystal materials containing one polymeric liquid crystal component and other non-reactive liquid crystals. A non-linear pitch gradient has been created during a process called polymerization induced molecular re-distribution. The polarizers in the visible exhibits a high extinction ration (over 30:1) over a bandwidth from 400 to 1,000 nm. When

Le Li; Jianfeng Li; Bunsen Fan; Yingqui Jiang; Sadeg M. Faris

1998-01-01

111

Dendrimers in biomedical applications—reflections on the field  

Microsoft Academic Search

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

Sönke Svenson; Donald A. Tomalia

2005-01-01

112

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

NASA Astrophysics Data System (ADS)

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

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

2011-06-01

113

Video-rate confocal endoscopy.  

PubMed

Rigid endoscopes provide high quality optical images of reasonably accessible regions of the inner body, especially regions such as the aero-digestive and genital tracts. In order to enhance the versatility of these instruments we describe a development that permits confocal endoscopic images to be obtained - along with traditional endoscopic images - in real-time, from within the living patient. The system is based around a host lenslet-array tandem scanning microscope, which is capable of producing images viewed directly by eye. These types of confocal microscope are configured for fluorescence imaging together with laser illumination. Hard and soft tissues in the mouth were imaged using this combined system. PMID:12135457

Watson, T F; Neil, M A A; Juskaitis, R; Cook, R J; Wilson, T

2002-07-01

114

Developments of new force reflecting control schemes and an application to a teleoperation training simulator  

NASA Technical Reports Server (NTRS)

Two schemes of force reflecting control, position-error based force reflection and low-pass-filtered force reflection, both combined with shared compliance control, were developed for dissimilar master-slave arms. These schemes enabled high force reflection gains, which were not possible with a conventional scheme when the slave arm was much stiffer than the master arm. The experimental results with a peg-in-hole task indicated that the newly force reflecting control schemes combined with compliance control resulted in best task performances. As a related application, a simulated force reflection/shared compliance control teleoperation trainer was developed that provided the operator with the feel of kinesthetic force virtual reality.

Kim, Won S.

1992-01-01

115

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

116

Quantifying metarefraction with confocal lenslet arrays  

E-print Network

METATOYs can change the direction of light in ways that appear to, but do not actually, contravene the laws of wave optics. This direction change applies only to part of the transmitted light beam; the remainder gets re-directed differently. For a specific example, namely confocal lenslet arrays, we calculate here the fractions of power of an incident uniform plane wave get re-directed in different ways. This will facilitate assessment of the suitability of METATOYs for applications such as solar concentration.

Maceina, Tautvydas; Courtial, Johannes

2011-01-01

117

CONFOCAL MICROSCOPY SYSTEM PERFORMANCE: SPECTROSCOPY  

EPA Science Inventory

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

118

Simulation of a theta line-scanning confocal microscope.  

PubMed

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

Simon, Blair; Dimarzio, Charles A

2007-01-01

119

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

NASA Astrophysics Data System (ADS)

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

Sandmann, Christian

120

Optical Electronic Bragg Reflection Sensor System with Hydrodynamic Flow Applications  

NASA Technical Reports Server (NTRS)

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

Lyons, D. R.

2003-01-01

121

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

122

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

PubMed

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

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

2007-01-01

123

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

PubMed

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

Mazzotta, Cosimo; Caragiuli, Stefano; Caporossi, Aldo

2014-06-01

124

The relaxed confocal scanning laser ophthalmoscope.  

PubMed

The development of the Scanning Laser Ophthalmoscope is reviewed from a historical perspective. Since a flying-spot scanning principle for an electro-optical ophthalmoscope was first disclosed in 1950, enabling milestones have included the introduction of the laser and inversion of the usual Gullstrand's configuration of optical pupils in 1977, and the application of the optical principle of confocality by means of double or de-scanning in 1983. As a result, high resolution and high contrast confocal infra-red ophthalmoscopy with a 790 nm diode laser, at video rates, is a major novel imaging modality when compared to traditional optical techniques. This imaging mode is ideal to provide the necessary fiducial landmarks for microperimetry, therapeutic laser and SD-OCT based optical sectioning of the retina. DPSS or He-Ne lasers emitting at 532, 543, 561 or 575 nm are used for complimentary red-free fundus imaging. The diode 790 nm and DPSS 490 nm lasers are also used for fluorescence excitation. PMID:17265788

Van de Velde, F J

2006-01-01

125

Fungal Keratitis – Improving Diagnostics by Confocal Microscopy  

PubMed Central

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

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

2013-01-01

126

Combined confocal Raman and quantitative phase microscopy system for biomedical diagnosis  

PubMed Central

We have developed a novel multimodal microscopy system that incorporates confocal Raman, confocal reflectance, and quantitative phase microscopy (QPM) into a single imaging entity. Confocal Raman microscopy provides detailed chemical information from the sample, while confocal reflectance and quantitative phase microscopy show detailed morphology. Combining these intrinsic contrast imaging modalities makes it possible to obtain quantitative morphological and chemical information without exogenous staining. For validation and characterization, we have used this multi-modal system to investigate healthy and diseased blood samples. We first show that the thickness of a healthy red blood cell (RBC) shows good correlation with its hemoglobin distribution. Further, in malaria infected RBCs, we successfully image the distribution of hemozoin (malaria pigment) inside the cell. Our observations lead us to propose morphological screening by QPM and subsequent chemical imaging by Raman for investigating blood disorders. This new approach allows monitoring cell development and cell-drug interactions with minimal perturbation of the biological system of interest. PMID:21991542

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

2011-01-01

127

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

SciTech Connect

We describe methods for creating solar-reflective nonwhitesurfaces and their application to a wide variety of residential roofingmaterials, including metal, clay tile, concrete tile, wood, and asphaltshingle. Reflectance in the near-infrared (NIR) spectrum (0.7 2.5mu m) ismaximized by coloring a topcoatwith pigments that weakly absorb and(optionally) strongly backscatter NIR radiation, and adding anNIR-reflective basecoat (e.g., titanium dioxide white) if both thetopcoat and substrate weakly reflect NIR radiation. Coated steel andglazed clay tile roofing products achieved NIRreflectances of up to 0.50and 0.75, respectively, using only cool topcoats. Gray concrete tilesachieve NIR reflectances as high as 0.60 when thickly coated withNIR-scattering pigments, and could attain an NIR reflectances as high as0.85 by overlaying a titanium-dioxide basecoat with a topcoat colored byNIR-transparent organic pigments. Granule-surfaced asphalt shinglesachieved NIR reflectances as high as 0.45 when a cool color topcoat wasapplied over a thick white basecoat.

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

2005-05-24

128

Study of liquid jet instability by confocal microscopy  

NASA Astrophysics Data System (ADS)

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

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

2012-07-01

129

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

PubMed Central

In this review paper, the conceptual basis and experimental design of total internal reflection with fluorescence correlation spectroscopy (TIR-FCS) is described. The few applications to date of TIR-FCS to supported membranes are discussed, in addition to a variety of applications not directly involving supported membranes. Methods related, but not technically equivalent, to TIR-FCS are also summarized. Future directions for TIR-FCS are outlined. PMID:19269331

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

2009-01-01

130

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

E-print Network

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

131

Atomic layer deposited Al2O3 films for anti-reflectance and surface passivation applications  

NASA Astrophysics Data System (ADS)

Al2O3 films were deposited on n-type crystalline Si (c-Si) wafers by atomic layer deposition using Al(CH3)3 and H2O as precursors. Surface anti-reflectance and passivation performances were investigated. Average reflectances between 2.8 and 4.2% were obtained for Al2O3 coated textured Si with Al2O3 thickness ranged between 100 and 70 nm. Wide thickness window for low reflectance between 2.8 and 4.2% indicates its potential anti-reflectance applications. A high minor carrier lifetime of ˜4.5 ms is obtained for n-type c-Si wafers passivated by 100 nm Al2O3 films, corresponding to an effective surface recombination velocity of ˜4 cm/s. Wide annealing time window and wide annealing temperature window are addressed to obtain good passivation performances with high minor carrier lifetime >3 ms. The passivation performances are related to the released H atoms from Al-OH bonds and the formation of Al vacancies and O interstitials within Al2O3 films. Our results indicate that Al2O3 films show dual functions of anti-reflectance and surface passivation for photovoltaic applications.

Zhu, Li Qiang; Liu, Yang Hui; Zhang, Hong Liang; Xiao, Hui; Guo, Li Qiang

2014-01-01

132

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

133

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

NASA Astrophysics Data System (ADS)

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

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

2014-11-01

134

Confocal imaging through an endoscopic rod  

NASA Astrophysics Data System (ADS)

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

Galloway, Matt; Gabriel, Kayla; Dobre, George

2014-01-01

135

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...

136

An evaluation of confocal versus conventional imaging of biological structures by fluorescence light microscopy  

PubMed Central

Scanning confocal microscopes offer improved rejection of out-of-focus noise and greater resolution than conventional imaging. In such a microscope, the imaging and condenser lenses are identical and confocal. These two lenses are replaced by a single lens when epi- illumination is used, making confocal imaging particularly applicable to incident light microscopy. We describe the results we have obtained with a confocal system in which scanning is performed by moving the light beam, rather than the stage. This system is considerably faster than the scanned stage microscope and is easy to use. We have found that confocal imaging gives greatly enhanced images of biological structures viewed with epifluorescence. The improvements are such that it is possible to optically section thick specimens with little degradation in the image quality of interior sections. PMID:3112165

1987-01-01

137

Confocal Microscopy–Guided Laser Ablation for Superficial and Early Nodular Basal Cell Carcinoma  

PubMed Central

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

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

2014-01-01

138

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

PubMed

We present the design and operation of a fiber-based cryogenic confocal microscope. It is designed as a compact cold-finger that fits inside the bore of a superconducting magnet, and which is a modular unit that can be easily swapped between use in a dilution refrigerator and other cryostats. We aimed at application in quantum optical experiments with electron spins in semiconductors and the design has been optimized for driving with and detection of optical fields with well-defined polarizations. This was implemented with optical access via a polarization maintaining fiber together with Voigt geometry at the cold finger, which circumvents Faraday rotations in the optical components in high magnetic fields. Our unit is versatile for use in experiments that measure photoluminescence, reflection, or transmission, as we demonstrate with a quantum optical experiment with an ensemble of donor-bound electrons in a thin GaAs film. PMID:21528993

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

2011-04-01

139

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

140

Reciprocity Principle Applicable to Reflected Radiance Measurements and the Searchlight Problem  

NASA Astrophysics Data System (ADS)

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

di Girolamo, Larry

1999-05-01

141

Confocal imaging of butterfly tissue.  

PubMed

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

Brunetti, Craig R

2014-01-01

142

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...

143

Confocal endomicroscopy of the larynx  

NASA Astrophysics Data System (ADS)

Beside the good image quality with the confocal laser scanning microscope (HRTII) and the Rostock Cornea Module (RCM), this technology can not be used to investigate the human larynx in vivo. To accomplish this, a rigid custom-made endoscope (KARL STORZ GmbH & Co. KG; Tuttlingen Germany) was developed. A connector was developed to connect the scanner head of the HRTII to the rigid endoscope. With the connector, the starting plane can be set manually. To achieve optical sectioning of the laryngeal tissue (80 ?m per volume scan), the scanning mechanism of the HRTII needs to be activated using a foot switch. The devices consisting of the endoscope, HRTII, and the connector supply images of 400 x 400 ?m and reach average penetration depths of 100-300 ?m (?/4 plate of the scanner head of the HRTII was removed). The lateral and axial resolutions are about 1-2 ?m and 2 ?m, respectively. In vivo rigid confocal endoscopy is demonstrated with an acquisition time for a volume scan of 6 s. The aim of this study was to differentiate pre-malignant laryngeal lesions from micro-invasive carcinoma of the larynx. 22 patients with suspicious lesions of the true vocal cords were included. This pilot study clearly demonstrates the possibility to detect dysplastic cells close to the basal cell layer and within the subepithelial space in lesions with small leukoplakia (thin keratin layer). These findings may have an impact on microlaryngoscopy to improve the precision for biopsy and on microlaryngoscopic laser surgery of the larynx to identify the margins of the pre-malignant lesion.

Just, T.; Wiechmann, T.; Stachs, O.; Stave, J.; Guthoff, R.; Hüttmann, G.; Pau, H. W.

2012-02-01

144

Integrated photoacoustic, confocal, and two-photon microscope.  

PubMed

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

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

2014-03-01

145

Clinical Reflectance Confocal Microscope for Imaging of Oral Cancer  

E-print Network

Biopsy and histopathology remain the standard method for diagnosis of oral cancer in the clinic today. Early detection of oral cancer is fundamental to a higher survival rate, and a non-invasive method is preferred. This is possible through optical...

Jabbour, Joey

2014-08-05

146

A handheld laser scanning confocal reflectance imagingconfocal Raman  

E-print Network

­ 594 (2007). 5. M. Claybourn and M. Ansell, "Using Raman spectroscopy to solve crime: inks, questioned. Speicher, and F. Hofer, "Different staining substances were used in decorative and therapeutic tattoos

Maxwell, Bruce D.

147

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. PMID:21709875

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

2011-01-01

148

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

Microsoft Academic Search

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

John F. Mustard; Carlé M. Pieters

1989-01-01

149

CONFOCAL MICROSCOPY SYSTEM PERFORMANCE: AXIAL RESOLUTION  

EPA Science Inventory

Abstract Confocal Microscopy System Performance: Axial resolution. Robert M. Zucker, PhD Reproductive Toxicology Division, National Health and Environmental Effects Research Laboratory, Office of Research and Development, U.S. Environmental Protection Agency, Re...

150

Confocal Raman Microspectroscopy of Oral Streptococci  

NASA Astrophysics Data System (ADS)

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

Beier, Brooke D.

151

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

152

Chromatic confocal microscopy using staircase diffractive surface.  

PubMed

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

Rayer, Mathieu; Mansfield, Daniel

2014-08-10

153

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

154

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

E-print Network

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

Gimenez, Clayton C. (Clayton Christopher)

2014-01-01

155

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

156

Optical characterization and confocal fluorescence imaging of mechanochromic acrylate polymers  

NASA Astrophysics Data System (ADS)

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

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

2015-01-01

157

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

SciTech Connect

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

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

2014-03-24

158

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

NASA Astrophysics Data System (ADS)

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

Jayasinghe, J. A. Ranga Chaminda

159

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

PubMed

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

Cairós, Carlos; Coello, Jordi; Maspoch, Santiago

2008-12-01

160

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

NASA Astrophysics Data System (ADS)

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

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

2013-12-01

161

Confocal microlaparoscope for imaging the fallopian tube  

NASA Astrophysics Data System (ADS)

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

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

2014-11-01

162

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

PubMed

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

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

2010-05-01

163

[Application of reflection infrared sensor to intelligent water-saving system].  

PubMed

Utilizing reflection type infrared sensor and small electronic devices (monostable multivibrator), the authors have developed the intelligent water-saving control system. This system can discern whether someone enters the lavatory, produce the signal of washing according to the cirumstances, drives the electromagnetic valve to open, and pour water into the floater type cistern. After filling two cisterns of water enough for cleaning, it'll cut off the power in the electromagnetic valve automatically. This system has achieved the sanitary and economical purpose, using this system can economize water by about 70%. This system features few components, low costs, rational structure, reliable work, easy installation, and convenient maintenance, so it has a wide application prospect. PMID:17554909

Fu, He-ping

2007-03-01

164

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

PubMed

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

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

2011-03-01

165

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

NASA Astrophysics Data System (ADS)

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

Sapsford, Kim E.

166

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

167

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

SciTech Connect

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 to 9 ..mu.. and incidence angles of 12 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

168

Confocal fluorescence microscopy for rapid evaluation of invasive tumor cellularity of inflammatory breast carcinoma core needle biopsies.  

PubMed

Tissue sampling is a problematic issue for inflammatory breast carcinoma, and immediate evaluation following core needle biopsy is needed to evaluate specimen adequacy. We sought to determine if confocal fluorescence microscopy provides sufficient resolution to evaluate specimen adequacy by comparing invasive tumor cellularity estimated from standard histologic images to invasive tumor cellularity estimated from confocal images of breast core needle biopsy specimens. Grayscale confocal fluorescence images of breast core needle biopsy specimens were acquired following proflavine application. A breast-dedicated pathologist evaluated invasive tumor cellularity in histologic images with hematoxylin and eosin staining and in grayscale and false-colored confocal images of cores. Agreement between cellularity estimates was quantified using a kappa coefficient. 23 cores from 23 patients with suspected inflammatory breast carcinoma were imaged. Confocal images were acquired in an average of less than 2 min per core. Invasive tumor cellularity estimated from histologic and grayscale confocal images showed moderate agreement by kappa coefficient: ? = 0.48 ± 0.09 (p < 0.001). Grayscale confocal images require less than 2 min for acquisition and allow for evaluation of invasive tumor cellularity in breast core needle biopsy specimens with moderate agreement to histologic images. We show that confocal fluorescence microscopy can be performed immediately following specimen acquisition and could indicate the need for additional biopsies at the initial visit. PMID:25417171

Dobbs, Jessica; Krishnamurthy, Savitri; Kyrish, Matthew; Benveniste, Ana Paula; Yang, Wei; Richards-Kortum, Rebecca

2015-01-01

169

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

NASA Astrophysics Data System (ADS)

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

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

2014-08-01

170

Confocal Microscopy for Modeling Electron Microbeam Irradiation of Skin  

SciTech Connect

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

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

2011-08-01

171

Miniature objective lens with variable focus for confocal endomicroscopy  

PubMed Central

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

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

2014-01-01

172

Miniature objective lens with variable focus for confocal endomicroscopy.  

PubMed

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

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

2014-12-01

173

CONFOCAL MICROSCOPY SYSTEM PERFORMANCE: LASER POWER MEASUREMENTS  

EPA Science Inventory

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

174

Chromatic confocal microscopy using supercontinuum light  

Microsoft Academic Search

We report on a novel chromatic confocal microscope system using supercontinuum white light generated from a photonic crystal fiber. The chromatic aberration of a pair of singlet lenses is employed to focus the different spectral components of the supercontinuum at different depth levels. An effective depth scanning range of 7 µm is demonstrated. The corresponding depth resolution is measured to

Kebin Shi; Peng Li; Shizhuo Yin; Zhiwen Liu

2004-01-01

175

Axially resolved complete Mueller matrix confocal microscopy  

E-print Network

Axially resolved complete Mueller matrix confocal microscopy David Lara and Chris Dainty We system with a complete Mueller matrix polarimeter. To calibrate the system, a double-pass method had effect on axially resolved Mueller matrix measurements. © 2006 Optical Society of America OCIS codes: 110

Dainty, Chris

176

Confocal microscopy imaging of solid tissue  

EPA Science Inventory

Confocal laser scanning microscopy (CLSM) is a technique that is capable of generating serial sections of whole-mount tissue and then reassembling the computer acquired images as a virtual 3-dimensional structure. In many ways CLSM offers an alternative to traditional sectioning ...

177

Vibrometry using a chromatic confocal sensor  

NASA Astrophysics Data System (ADS)

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

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

2014-05-01

178

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

PubMed

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

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

2014-12-01

179

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

PubMed

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 of NIR to predict chemical composition (crude protein, intramuscular fat, moisture/dry matter, ash, gross energy, myoglobin and collagen), technological parameters (pH value; L*, a*, b* colour values; water holding capacity; Warner-Bratzler and slice shear force) and sensory attributes (colour, shape, marbling, odour, flavour, juiciness, tenderness or firmness) are reviewed. Secondly, the usefulness of NIR for classification into meat quality grades is presented and thirdly its potential application in the industry is shown. The review indicates that NIR showed high potential to predict chemical meat properties and to categorize meat into quality classes. In contrast, NIR showed limited ability for estimating technological and sensory attributes, which may be mainly due to the heterogeneity of the meat samples and their preparation, the low precision of the reference methods and the subjectivity of assessors in taste panels. Hence, future work to standardize sample preparation and increase the accuracy of reference methods is recommended to improve NIR ability to predict those technological and sensory characteristics. In conclusion, the review shows that NIR has a considerable potential to predict simultaneously numerous meat quality criteria. PMID:20416766

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

2009-10-01

180

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. PMID:24156054

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

2013-01-01

181

Analysis and Applications of Reflection-Spectrum Envelopes for Sampled Gratings  

Microsoft Academic Search

In this paper, an analytical method is proposed for calculating reflection-spectrum envelopes (RSEs) of various multipeak gratings. Consequently, impacts of parameters on the envelope of the sampled grating are analyzed in detail both with and without refractive index variation. Accuracy of those proposed methods has been verified by the good agreement with the simulated reflectivity spectrum of the transfer matrix

Xiaoying He; Yonglin Yu; Dexiu Huang; Ruikang Zhang; Wen Liu; Shan Jiang

2008-01-01

182

Dynamic Learning Need Reflection System for Academic Education and Its Applicability to Intelligent Agents  

Microsoft Academic Search

A new concept DLNR (dynamic learning need reflection) and its system used in the education at a university are suggested. The effects, particularly on the learning of software agents, are analyzed. DLNR's goal is to increase students' learning motivation through dynamically clarifying and reflecting their learning need. To attain this, DLNR includes \\

Yoshitaka Sakurai; Shinichi Dohi; Shogo Nakamura; Setsuo Tsuruta; Rainer Knauf

2006-01-01

183

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

NASA Technical Reports Server (NTRS)

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

Pepper, Stephen V.

1995-01-01

184

Digital differential confocal microscopy based on spatial shift transformation.  

PubMed

Differential confocal microscopy is a particularly powerful surface profilometry technique in industrial metrology due to its high axial sensitivity and insensitivity to noise. However, the practical implementation of the technique requires the accurate positioning of point detectors in three-dimensions. We describe a simple alternative based on spatial transformation of a through-focus series of images obtained from a homemade beam scanning confocal microscope. This digital differential confocal microscopy approach is described and compared with the traditional Differential confocal microscopy approach. The ease of use of the digital differential confocal microscopy system is illustrated by performing measurements on a 3D standard specimen. PMID:25303106

Liu, J; Wang, Y; Liu, C; Wilson, T; Wang, H; Tan, J

2014-11-01

185

Laser differential confocal paraboloidal vertex radius measurement.  

PubMed

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

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

2014-02-15

186

Axially resolved complete Mueller matrix confocal microscopy  

Microsoft Academic Search

We introduce a technique that is capable of obtaining complete polarization-sensitive three-dimensional images that could reveal unknown anatomical conditions of living tissue that possess polarization- dependent signatures. Previously, the 16 Mueller coefficients were measured independently only by use of two-dimensional imaging techniques. We also present the experimental combination of a depth-resolved confocal imaging system with a complete Mueller matrix polarimeter.

David Lara; Chris Dainty

2006-01-01

187

MEMS-Based Dual Axes Confocal Microendoscopy  

PubMed Central

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

Piyawattanametha, Wibool; Wang, Thomas D.

2011-01-01

188

Two-channel, quasi-confocal parallel scan fluorescence imaging for detection of biochips  

NASA Astrophysics Data System (ADS)

Biochips have advanced tremendously for biomedical applications in recent years. New fluorescence imaging methods have been developed for biochip analysis. In this work, a two-channel, quasi-confocal parallel scan fluorescence imaging method is proposed for detection of biochips. An imaging system was developed with one-dimensional optical scan to produce two-dimensional wide-field images, and the system was designed to enable simple exchange of lasers covering different spectral regions. The mechanism of quasi-confocal imaging provides a sensitivity of 0.46 fluorescence molecules per square micron, while parallel scan makes it a high throughput technique for rapid detection of biochips.

Liu, Zhiyi; He, Yonghong; Liu, Le; Ma, Suihua; Chong, Xinyuan; Hu, Zhaoxu; Ma, Hui; Guo, Jihua

2010-09-01

189

In vivo confocal imaging of the retina in animal models using scanning laser ophthalmoscopy  

Microsoft Academic Search

Scanning-laser ophthalmoscopy is a technique for confocal imaging of the\\u000a eye in vivo. The use of lasers of different wavelengths allows to obtain\\u000a information about specific tissues and layers due to their reflection\\u000a and transmission characteristics. In addition, fluorescent dyes\\u000a excitable in the blue and infrared range offer a unique access to the\\u000a vascular structures associated with each layer. In

Mathias W. Seeliger; Susanne C. Beck; N Pereyra-Munoz; Susann Dangel; Jen-Yue Tsai; Ulrich F. O. Luhmann; Serge A. van de Pavert; Jan Wijnholds; Marijana Samardzija; Andreas Wenzel; Eberhart Zrenner; K Narfstrom; Edda Fahl; Naoyuki Tanimoto; Niyazi Acar; Felix Tonagel

2005-01-01

190

A near-infrared confocal scanner  

NASA Astrophysics Data System (ADS)

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

Lee, Seungwoo; Yoo, Hongki

2014-06-01

191

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

192

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

193

Confocal Ellipsoidal Reflector System for a Mechanically Scanned Active Terahertz Imager  

Microsoft Academic Search

We present the design of a reflector system that can rapidly scan and refocus a terahertz beam for high-resolution standoff imaging applications. The proposed optical system utilizes a confocal Gregorian geometry with a small mechanical rotating mirror and an axial displacement of the feed. For operation at submillimeter wavelengths and standoff ranges of many meters, the imaging targets are electrically

Nuria Llombart; Ken B. Cooper; Robert J. Dengler; Tomas Bryllert; Peter H. Siegel

2010-01-01

194

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

PubMed Central

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

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

2012-01-01

195

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

196

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

NASA Technical Reports Server (NTRS)

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

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

1976-01-01

197

Middleware enabling computational self-reflection: exploring the need for and some costs of selfreflecting networks with application to homeland defense  

NASA Astrophysics Data System (ADS)

This paper will review and examine the definitions of Self-Reflection and Active Middleware. Then it will illustrate a conceptual framework for understanding and enumerating the costs of Self-Reflection and Active Middleware at increasing levels of Application. Then it will review some application of Self-Reflection and Active Middleware to simulations. Finally it will consider the application and additional kinds of costs applying Self-Reflection and Active Middleware to sharing information among the organizations expected to participate in Homeland Defense.

Kramer, Michael J.; Bellman, Kirstie L.; Landauer, Christopher

2002-07-01

198

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

199

Variational attenuation correction in two-view confocal microscopy  

PubMed Central

Background Absorption and refraction induced signal attenuation can seriously hinder the extraction of quantitative information from confocal microscopic data. This signal attenuation can be estimated and corrected by algorithms that use physical image formation models. Especially in thick heterogeneous samples, current single view based models are unable to solve the underdetermined problem of estimating the attenuation-free intensities. Results We present a variational approach to estimate both, the real intensities and the spatially variant attenuation from two views of the same sample from opposite sides. Assuming noise-free measurements throughout the whole volume and pure absorption, this would in theory allow a perfect reconstruction without further assumptions. To cope with real world data, our approach respects photon noise, estimates apparent bleaching between the two recordings, and constrains the attenuation field to be smooth and sparse to avoid spurious attenuation estimates in regions lacking valid measurements. Conclusions We quantify the reconstruction quality on simulated data and compare it to the state-of-the art two-view approach and commonly used one-factor-per-slice approaches like the exponential decay model. Additionally we show its real-world applicability on model organisms from zoology (zebrafish) and botany (Arabidopsis). The results from these experiments show that the proposed approach improves the quantification of confocal microscopic data of thick specimen. PMID:24350574

2013-01-01

200

Confocal detection of planar homogeneous and heterogeneous immunosorbent assays  

NASA Astrophysics Data System (ADS)

Optically sectioned detection of fluorescence immunoassays using a confocal microscope enables the creation of both homo- and heterogeneous planar format assays. We report a set assays requiring optically sectioned detection using a model system and analysis procedures for separating signals of a surface layer from an overlying solution. A model sandwich assay with human immunoglobulin G as the target antigen is created on a glass substrate. The prepared surfaces are exposed to antigen and a FITC-labeled secondary antibody. The resulting preparations are either read directly to provide a homogeneous assay or after wash steps, giving a heterogeneous assay. The simplicity of the object shapes arising from the planar format makes the decomposition of analyte signals from the thin film bound to the surface and overlayer straightforward. Measured response functions of the thin film and overlayer fit well to the Cauchy-Lorentz and cumulative Cauchy-Lorentz functions, respectively, enabling the film and overlayer to be separated. Under the conditions used, the detection limits for the homogeneous and heterogeneous forms of the assay are 2.2 and 5.5 ng/ml, respectively. Planar format, confocally read fluorescence assays enable wash-free detection of antigens and should be applicable to a wide range of assays involving surface-bound species.

Ghafari, Homanaz; Zhou, Yanzhou; Ali, Selman; Hanley, Quentin S.

2009-11-01

201

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

202

Intravital confocal and two-photon imaging of dual-color cells and extracellular matrix mimics.  

PubMed

We report our efforts in identifying optimal scanning laser microscope parameters to study cells in three-dimensional culture. For this purpose we studied contrast of extracellular matrix (ECM) mimics, as well as signal attenuation, and bleaching of red and green fluorescent protein labeled cells. Confocal backscattering, second harmonic generation (SHG), and autofluorescence were sources of contrast in ECM mimics. All common ECM mimics exhibit contrast observable with confocal reflectance microscopy. SHG imaging on collagen I based hydrogels provides high contrast and good optical penetration depth. Agarose is a useful embedding medium because it allows for large optical penetration and exhibits minimal autofluorescence. We labeled breast cancer cells' outline with DsRed2 and nucleus with enhanced green fluorescent protein (eGFP). We observed significant difference both for the bleaching rates of eGFP and DsRed2 where bleaching is strongest during two-photon excitation (TPE) and smallest during confocal imaging. But for eGFP the bleaching rate difference is smaller than for DsRed2. After a few hundred microns depth in a collagen I hydrogel, TPE fluorescence of DsRed2 becomes twice as strong compared to confocal imaging. In fibrin and agarose gels, the imaging depth will need to be beyond 1 mm to notice a TPE advantage. PMID:23380006

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

2013-02-01

203

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

NASA Astrophysics Data System (ADS)

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

Diner, David

2010-05-01

204

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

NASA Astrophysics Data System (ADS)

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

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

2007-02-01

205

Imaging System With Confocally Self-Detecting Laser.  

DOEpatents

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

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

1996-10-08

206

Confocal imaging of benign and malignant proliferative skin lesions in vivo  

NASA Astrophysics Data System (ADS)

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

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

1999-06-01

207

Reflection and open implementations  

E-print Network

We review the state-of-the-art of reflection and metaprogramming, prior to our work on partial behavioral reflection and Reflex, and open implementations. The first four sections are dedicated to reflection. Section 1 introduces the concept of reflection and its application to programming languages. Section 2 discusses reflection in the particular context of object-oriented programming languages. Then, since we are interested in addressing issues in the concrete applicability of reflection, we dedicate Section 3 to the structuring and engineering of metalevel architectures, while implementation considerations are dealt with in Section 4. After this comprehensive review of reflection, the last section discusses the related area of open implementations (Section 5).

Éric Tanter

2009-01-01

208

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

209

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

NASA Astrophysics Data System (ADS)

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

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

1993-04-01

210

Reflectance spectra of mafic silicate-opaque assemblages with applications to meteorite spectra  

NASA Astrophysics Data System (ADS)

The addition of fine-grained magnetite to mafic silicate spectra can impart not only an overall blue slope, but also lower overall reflectance and band intensities. The reflectance spectra of the CO and CV magnetite-bearing carbonaceous chondrites are noted to exhibit many of these features; the low band depths of these meteorites suggest that an additional dark, neutral phase, such as ordered carbon, is present. Carbon + mafic silicate spectra possess a red overall slope at low amorphous carbon concentrations. The parent bodies of some of the darkest meteorites should exhibit spectral features attributable to mafic silicates.

Cloutis, E. A.; Gaffey, M. J.; Smith, D. G. W.; Lambert, R. St. J.

1990-04-01

211

Quality Control Protocol for Confocal Systems  

PubMed Central

Quantitative analysis of confocal imaging experiments require more stringent quality control of instrument function than qualitative imaging. Unfortunately, there are no standard procedures for quality control that are uniformly implemented, and, in multi user facilities experimenters rarely have access to the QC information. This paper proposes an easy and very efficient protocol that could be performed at the beginning of each day, experiment or even slide. It takes only a few minutes to assess laser stability, stage stability, channel registration in 3 dimensions and flatness of field. The information may be used either to calibrate data or, in more severe cases to request servicing the instrument. PMID:23317897

Cornea, Anda

2014-01-01

212

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

213

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

214

An application of reflected diffusions to the problem of choosing between hydro and thermal power generation  

Microsoft Academic Search

It is shown that a certain type of stochastic control problems has a solution (optimal stochastic process) which can be realized as a diffusion with vertical reflection on the boundary of a planar set. The stochastic control problem is motivated by the specific question whether further expansion of the electricity supply system should be based on thermal power (where only

T. Ø. Kobila

1993-01-01

215

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

NASA Technical Reports Server (NTRS)

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

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

1999-01-01

216

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

PubMed Central

We aimed to evaluate technical aspects and the clinical relevance of a simultaneous confocal scanning laser ophthalmoscope and a high-speed, high-resolution, spectral-domain optical coherence tomography (SDOCT) device for retinal imaging. The principle of confocal scanning laser imaging provides a high resolution of retinal and choroidal vasculature with low light exposure. Enhanced contrast, details, and image sharpness are generated using confocality. The real-time SDOCT provides a new level of accuracy for assessment of the angiographic and morphological correlation. The combined system allows for simultaneous recordings of topographic and tomographic images with accurate correlation between them. Also it can provide simultaneous multimodal imaging of retinal pathologies, such as fluorescein and indocyanine green angiographies, infrared and blue reflectance (red-free) images, fundus autofluorescence images, and OCT scans (Spectralis HRA?+?OCT; Heidelberg Engineering, Heidelberg, Germany). The combination of various macular diagnostic tools can lead to a better understanding and improved knowledge of macular diseases. PMID:22132313

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

2011-01-01

217

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

PubMed

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

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

2014-08-15

218

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

SciTech Connect

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

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

1999-04-01

219

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

NASA Astrophysics Data System (ADS)

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

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

1985-12-01

220

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

221

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

222

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. PMID:17134198

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

2008-01-01

223

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

224

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

NASA Astrophysics Data System (ADS)

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

Zalevsky, Zeev; Ilovitsh, Asaf; Beiderman, Yevgeny

2013-10-01

225

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

SciTech Connect

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

Banerjee, Amit, E-mail: erdd@iacs.res.in; Das, Debajyoti, E-mail: erdd@iacs.res.in [Nano-Science Group, Energy Research Unit, Indian Association for the Cultivation of Science, Jadavpur, Kolkata-700032 (India)

2014-04-24

226

Pyrometry for turbine applications in the presence of reflection and combustion  

SciTech Connect

This article describes on-line correction algorithms using triple-band pyrometry and data sorting. The objective is to generate on-line correction for flame in the field of view and levels of reflection exceeding 70% of input signal from a spectrally variable source. Results show success of applying these methods. Additionally, these methods provide cost-effective temperature data for turbine blade cooling development in the harsh and complex radiative environment of the first turbine, where other methods have failed. 3 refs.

Suarez, E. [Pratt & Whitney, West Palm Beach, FL (United States)

1994-11-01

227

Mueller matrix differential decomposition for direction reversal: application to samples measured in reflection and backscattering  

NASA Astrophysics Data System (ADS)

Mueller matrix differential decomposition is a novel method for analyzing the polarimetric properties of optical samples. It is performed through an eigenanalysis of the Mueller matrix and the subsequent decomposition of the corresponding differential Mueller matrix into the complete set of 16 differential matrices which characterize depolarizing anisotropic media. The method has been proposed so far only for measurements in transmission configuration. In this work the method is extended to the backward direction. The modifications of the differential matrices according to the reference system are discussed. The method is successfully applied to Mueller matrices measured in reflection and backscattering.

Ortega-Quijano, Noé; Arce-Diego, José Luis

2011-07-01

228

Mueller matrix differential decomposition for direction reversal: application to samples measured in reflection and backscattering.  

PubMed

Mueller matrix differential decomposition is a novel method for analyzing the polarimetric properties of optical samples. It is performed through an eigenanalysis of the Mueller matrix and the subsequent decomposition of the corresponding differential Mueller matrix into the complete set of 16 differential matrices which characterize depolarizing anisotropic media. The method has been proposed so far only for measurements in transmission configuration. In this work the method is extended to the backward direction. The modifications of the differential matrices according to the reference system are discussed. The method is successfully applied to Mueller matrices measured in reflection and backscattering. PMID:21934798

Ortega-Quijano, Noé; Arce-Diego, José Luis

2011-07-18

229

Three-dimensional scanning confocal laser microscope  

DOEpatents

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

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

1999-01-01

230

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...

231

Double-pass axially resolved confocal Mueller matrix imaging polarimetry  

E-print Network

Double-pass axially resolved confocal Mueller matrix imaging polarimetry David Lara and Chris is to the best of our knowledge the first combination of a confocal imaging system with a complete Mueller matrix, may ac- quire incorrect retardance measurements of a depo- larizing sample. A Mueller matrix is a 4

Dainty, Chris

232

CONFOCAL LASER SCANNING MICROSCOPY OF RAT FOLLICLE DEVELOPMENT  

EPA Science Inventory

This study used confocal laser scanning microscopy (CLSM) to study follicular development in millimeter pieces of rat ovary. To use this technology, it is essential to stain the tissue before laser excitation with the confocal microscope. Various fluorescent stains (Yo-Pro, Bo-Pr...

233

In vivo integrated photoacoustic and confocal microscopy of hemoglobin  

E-print Network

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

Wang, Lihong

234

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

NASA Astrophysics Data System (ADS)

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

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

2012-05-01

235

Quantification of confocal images of biofilms grown on irregular surfaces.  

PubMed

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

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

2014-05-01

236

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

E-print Network

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

Cone, Michael Thomas

2014-04-16

237

Reduced light reflection of textured multicrystalline silicon via NPD for solar cells applications  

Microsoft Academic Search

Texturing by negative potential dissolution (NPD) process of p-type multicrystalline silicon for solar cells application is reported. The effect of the negative potential, KOH concentration, and texturing time of cast multicrystalline silicon was studied. Rapid texturing of multicrystalline silicon was achieved in a time-frame of 2min with the application of negative potential of ?30V and the use of optimal alkaline

Y. Ein-Eli; N. Gordon; D. Starosvetsky

2006-01-01

238

Cascaded holographic polymer reflection grating filters for optical-code-division multiple-access applications.  

PubMed

We evaluate the use of edge-illuminated holographic Bragg filters formed in phenanthrenequinone-doped poly(methyl methacrylate) for optical-code-division multiple-access (OCDMA) coding and decoding applications. Experimental cascaded Bragg filters are formed to select two different wavelengths with a fixed distance between the gratings and are directly coupled to a fiber-measurement system. The configuration and tolerances of the cascaded gratings are shown to be practical for time-wavelength OCDMA applications. PMID:16363782

Kostuk, Raymond K; Maeda, Wendi; Chen, Chia-Hung; Djordjevic, Ivan; Vasic, Bane

2005-12-10

239

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

NASA Technical Reports Server (NTRS)

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

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

2012-01-01

240

Application of a zirconium fluoride fiber optic diffuse reflectance probe for the remote identification of solids  

NASA Astrophysics Data System (ADS)

A novel fiber optic-based probe for the identification of pure and contaminated solids has been developed. Ultimately, this probe is to be used to characterize the make-up and degree of contamination of hazardous waste sites as a preliminary step in the clean-up process. The transmission range of zirconium fluoride fibers allows for the measurement of fundamental stretching frequencies in the mid-infrared (MIR) region as well as overtone and combination bands in the near-infrared (NIR) region. This provides a substantial increase of the measurable concentration range of this MIR/NIR system with respect to systems which can measure only MIR or NIR information. The spectra of samples measured using this fiber optic system is compared to spectra measured in a standard in-compartment diffuse reflectance accessory. The spectra are evaluated in terms of signal-to-noise, measurement time, and detection limits.

Chaffin, Nathan C.; Lewis, Ian R.; Griffiths, Peter R.

1995-04-01

241

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

PubMed Central

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

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

2012-01-01

242

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

NASA Astrophysics Data System (ADS)

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

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

2013-11-01

243

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

PubMed

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 microm from the ATR sampling unit surface (a 7 cm(2) hydrophobic ZnSe crystal). Applying a 0.2-0.3 microm thick film on the ATR unit surface, any chemical changes within this film as well as at the interface can be continuously monitored, even having an aqueous phase on top of the film. Infrared film analysis is considered especially useful for studying detergent enzymes, which act on surface bound films consisting of food component like vegetable oils (triacylglycerols) and carbohydrates (e.g. starch). Experimental data are presented for hydrolysis of a triacylglycerol film (triolein) by use of a triacylglycerol lipase (cutinase), and starch film degradation by use of an alpha-amylase. PMID:11911924

Snabe, Torben; Petersen, Steffen Bjørn

2002-05-01

244

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

245

Retrofitted confocal laser scanner for a commercial inverted fluorescence microscope  

NASA Astrophysics Data System (ADS)

We describe the design and implementation of an inverted laser scanning confocal fluorescence microscope utilizing the commercial Nikon Diaphot TMD platform. An external confocal scanner was retrofitted through the video side port of the Diaphot. With 10×, 0.5 NA dry and 60×, 1.4 NA oil immersion objectives, the depth discrimination is 5.8 ?m and 0.8 ?m, respectively, as determined by derivatives of fluorescence edge responses measured in liquid samples of rhodamine 6G dissolved in DMSO. We present sample edge response curves and representative confocal fluorescence images of tumor cells in monolayer culture.

Bigelow, Chad E.; Harkrider, Curtis J.; Conover, David L.; Foster, Thomas H.; Georgakoudi, Irene; Mitra, Soumya; Nichols, Michael G.; Rajadhyaksha, Milind

2001-08-01

246

Optimization of confocal scanning laser ophthalmoscope design.  

PubMed

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

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

2013-07-01

247

Optimization of confocal scanning laser ophthalmoscope design  

PubMed Central

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

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

2013-01-01

248

Using confocal scanning laser microscopy for the in situ study of high-temperature behaviour of complex ceramic materials  

Microsoft Academic Search

The confocal scanning laser microscopy (CSLM) technique has been successful in many metallurgical fields. This paper assesses its applicability to the in situ investigation of the high-temperature behaviour of complex ceramic materials. Magnesia–chromite refractory is selected as a ceramic test material. At room temperature, CSLM images correspond well to typical light optical microscopy (LOM) and backscattered electron (BSE) micrographs. In

Peter Tom Jones; David Desmet; Muxing Guo; Dirk Durinck; Frederik Verhaeghe; Joris Van Dyck; Junhu Liu; Bart Blanpain; Patrick Wollants

2007-01-01

249

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

NASA Astrophysics Data System (ADS)

Regenerative medicine brings a huge application for Mesenchymal stem cells such as Dental Pulp Stem Cells (DPSCs). Confocal Raman microscopy, a non-invasive, label free , real time and high spatial resolution imaging technique is used to study osteogenic differentiation of DPSCs. Integrated Raman intensities in the 2800-3000 cm-1 region (C-H stretching) and 960 cm-1 peak (phosphate PO4 3-) were collected. In Dental Pulp Stem Cells 21st day differentiated in buffer solution, phosphate peaks ?1 PO4 3- (first vibrational mode) at 960cm-1 and ?2 PO4 3- at 430cm-1 and ?4 PO4 3- at 585cm-1 are obviously present. Confocal Raman microscopy enables the detection of cell differentiation and it can be used to investigate clinical stem cell research.

Salehi, H.; Collart-Dutilleul, P.-Y.; Gergely, C.; Cuisinier, F. J. G.

2014-03-01

250

Single molecule confocal fluorescence lifetime correlation spectroscopy for accurate nanoparticle size determination.  

PubMed

We report on an experimental procedure in confocal single molecule fluorescence lifetime correlation spectroscopy (FLCS) to determine the range of excitation power and molecular or particulate concentration in solution under which the application of an unmodified model autocorrelation function is justified. This procedure enables fitting of the autocorrelation to an accurate model to measure diffusion length (r) and diffusion time (?D) of single molecules in solution. We also report on the pinhole size dependency of r and ?D in a confocal FLCS platform. This procedure determines a set of experimental parameters with which the Stokes-Einstein (S-E) equation accurately measures the hydrodynamic radii of spherical nanoparticles, enabling the determination of the particle size range for which the hydrodynamic radius by the S-E equation measures the real particle radius. PMID:24879354

Chon, Bonghwan; Briggman, Kimberly; Hwang, Jeeseong

2014-07-14

251

CONFOCAL MICROSCOPY SYSTEM PERFORMANCE: QA TESTS, QUANTITATION AND SPECTROSCOPY  

EPA Science Inventory

Confocal Microscopy System Performance: QA tests, Quantitation and Spectroscopy. Robert M. Zucker 1 and Jeremy M. Lerner 2, 1Reproductive Toxicology Division, National Health and Environmental Effects Research Laboratory, Office of Research Development, U.S. Environmen...

252

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...

253

CONFOCAL LASER SCANNING MICROSCOPY OF APOPTOSIS IN WHOLE MOUSE OVARIES  

EPA Science Inventory

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

254

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...

255

Law of refraction for generalised confocal lenslet arrays  

NASA Astrophysics Data System (ADS)

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

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

2014-02-01

256

Observing the Coral Symbiome Using Laser Scanning Confocal Microscopy  

NSDL National Science Digital Library

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

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

2013-02-01

257

Confocal microscopy-based goniometry of barnacle cyprid permanent adhesive.  

PubMed

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

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

2013-06-01

258

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

PubMed

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

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

2014-03-10

259

Confocal Brillouin microscopy for three-dimensional mechanical imaging  

PubMed Central

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

Scarcelli, Giuliano; Yun, Seok Hyun

2009-01-01

260

Probing chirality of a lipid tubular by confocal Raman microscopy.  

PubMed

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

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

2010-11-01

261

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

262

Confocal Raman microscopy for investigating synthesis and characterization of individual optically trapped vinyl-polymerized surfactant particles.  

PubMed

Small polymeric particles are increasingly employed as adsorbent materials, as molecular carriers, as delivery vehicles, and in preconcentration applications. The rational development of these materials requires in situ methods of analysis to characterize their synthesis, structure, and applications. Optical-trapping confocal Raman microscopy is a spectroscopic method capable of acquiring information at several stages of the development of such dispersed particulate materials. In the present study, an example material is developed and tested using confocal Raman microscopy for characterization at each stage of the process. Specifically, the method is used to investigate the synthesis, structure, and applications of individual polymeric surfactant particles produced by the vinyl polymerization of sodium 11-acrylamidoundecanoate (SAAU). The kinetics of polymerization can be monitored over time by measuring the loss of the acrylamide C=C functional groups using confocal Raman microscopy of particles optically trapped by the excitation laser, where, within the limits of detecting the vinyl functional group, the complete polymerization of the SAAU monomer was achieved. The polymerized SAAU particles are spherical, and they exhibit uniform access to water throughout their structure, as tested by the penetration of heavy water (D2O) and collection of spatially resolved Raman spectra from the interior of the particle. These porous particles contain hydrophobic domains that can be used to accumulate molecules for adsorption or carrier applications. This property was tested by using confocal Raman microscopy to measure the accumulation equilibria and kinetics of a model compound, dioxybenzone. The partitioning of this compound into the polymer surfactant could be determined on a quantitative basis using relative scattering cross sections of the SAAU monomer and the adsorbate. The study points out the utility of optical-trapping confocal Raman microscopy for investigating the synthesis, structure, and potential carrier applications of polymeric particle materials. PMID:25014718

Schaefer, Jonathan J; Crawford, Alexis C; Porter, Marc D; Harris, Joel M

2014-01-01

263

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

PubMed Central

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

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

2014-01-01

264

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

NASA Astrophysics Data System (ADS)

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

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

2006-02-01

265

Atomic force microscopy and confocal laser scanning microscopy on the cytoskeleton of permeabilised and embedded cells.  

PubMed

We describe a technical method of cell permeabilisation and embedding to study the organisation and distribution of intracellular proteins with aid of atomic force microscopy and confocal laser scanning microscopy in identical areas. While confocal laser scanning microscopy is useful for the identification of certain proteins subsequent labelling with markers or antibodies, atomic force microscopy allows the observation of macromolecular structures in fixed and living cells. To demonstrate the field of application of this preparatory technique, cells were permeabilised, fixed, and the actin cytoskeleton was stained with phalloidin-rhodamine. Confocal laser scanning microscopy was used to show the organisation of these microfilaments, e.g. geodesic dome structures. Thereafter, cells were embedded in Durcupan water-soluble resin, followed by UV-polymerisation of resin at 4 degrees C. This procedure allowed intracellular visualisation of the cell nucleus or cytoskeletal elements by atomic force microscopy, for instance to analyse the globular organisation of actin filaments. Therefore, this method offers a great potential to combine both microscopy techniques in order to understand and interpret intracellular protein relations, for example, the biochemical and morphological interaction of the cytoskeleton. PMID:16360280

Meller, Karl; Theiss, Carsten

2006-03-01

266

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

PubMed

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

Späth, Andreas; Raabe, Jörg; Fink, Rainer H

2015-01-01

267

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

PubMed Central

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

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

2009-01-01

268

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

NASA Astrophysics Data System (ADS)

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

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

2007-02-01

269

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

PubMed

There is uncertainty on how generally applicable near-infrared reflectance spectroscopy (NIRS) calibrations are across genotypes and environments, and this study tests how well a single calibration performs across a wide range of conditions. We also address the optimization of NIRS to perform the analysis of crude protein (CP) content in a variety of cowpea accessions (n?=?561) representing genotypic variation as well as grown in a wide range of environmental conditions in Tanzania and Uganda. The samples were submitted to NIRS analysis and a predictive calibration model developed. A modified partial least-squares regression with cross-validation was used to evaluate the models and identify possible spectral outliers. Calibration statistics for CP suggests that NIRS can predict this parameter in a wide range of cowpea leaves from different agro-ecological zones of eastern Africa with high accuracy (R (2)cal?=?0.93; standard error of cross-validation?=?0.74). NIRS analysis improved when a calibration set was developed from samples selected to represent the range of spectral variability. We conclude from the present results that this technique is a good alternative to chemical analysis for the determination of CP contents in leaf samples from cowpea in the African context, as one of the main advantages of NIRS is the large number of compounds that can be measured at once in the same sample, thus substantially reducing the cost per analysis. The current model is applicable in predicting the CP content of young cowpea leaves for human nutrition from different agro-ecological zones and genetic materials, as cowpea leaves are one of the popular vegetables in the region. PMID:24804013

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

2013-01-01

270

Reflectivity Cheat Sheet Defining Reflection...  

E-print Network

Reflectivity Cheat Sheet Defining Reflection... · Casually connected. If the internal structures. A reflective system is then a system which incorporates causally con- nected structures representing itself-representation of a system can be modified. · Reflection = Introspection + Intercession · Meta-objects describe behavior

Nierstrasz, Oscar

271

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

E-print Network

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

Su, Xiao

272

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

SciTech Connect

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

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

2006-04-17

273

An adaptive phase space method with application to reflection traveltime tomography This article has been downloaded from IOPscience. Please scroll down to see the full text article.  

E-print Network

. For instance, in marine reflection seismology, the data are collected on a ship with a streamer that sends out tomography, in which the acoustic speed in biological tissues can be calculated from the arrival times of ultrasonic waves. Another area of application of traveltime tomography is ocean acoustics; see [33, 15, 7, 32

Qian, Jianliang

274

Theoretical analysis of reflected ray error from surface slope error and their application to the solar concentrated collector  

E-print Network

Surface slope error of concentrator is one of the main factors to influence the performance of the solar concentrated collectors which cause deviation of reflected ray and reduce the intercepted radiation. This paper presents the general equation to calculate the standard deviation of reflected ray error from slope error through geometry optics, applying the equation to calculate the standard deviation of reflected ray error for 5 kinds of solar concentrated reflector, provide typical results. The results indicate that the slope error is transferred to the reflected ray in more than 2 folds when the incidence angle is more than 0. The equation for reflected ray error is generally fit for all reflection surfaces, and can also be applied to control the error in designing an abaxial optical system.

Huang, Weidong

2011-01-01

275

The Reflective Learning Continuum: Reflecting on Reflection  

ERIC Educational Resources Information Center

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

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

2005-01-01

276

Cryogenic confocal microscopy with rotation in a magnetic field.  

PubMed

Two approaches to conducting magneto-optical confocal spectroscopy are described, in each of which the confocal head is rotatable with respect to the magnetic field. A coudé arrangement has been shown to give adequate performance for scanned imaging, but lower optical throughput than a system based on single-mode optical fiber transport. The design criteria for a cryogenic fiber-coupling objective are described, and the tolerances demanded in lens alignment are shown to be relatively benign, allowing manufacture without special techniques. The practical use of the rotating confocal system with commercial stick-slip positioners has been shown to be rigid enough, and asymmetric weight distribution and diamagnetic forces are small enough to permit single quantum emitters to be studied over a range of angles and field strengths. PMID:20113112

Kehoe, T; Ediger, M; Phillips, R T; Hopkinson, M

2010-01-01

277

Simple high-speed confocal line-scanning microscope  

NASA Astrophysics Data System (ADS)

Using a line scan camera and an acousto-optic deflector (AOD), we constructed a high-speed confocal laser line-scanning microscope that can generate confocal images (512 x 512 pixels) with up to 191 frames/s without any mechanically moving parts. The line scanner consists of an AOD and a cylindrical lens, which creates a line focus sweeping over the sample. The measured resolutions in z (depth), x (perpendicular to line focus), and y (direction of line focus) directions are 3.3 ?m, 0.7 ?m and 0.9 ?m, respectively, with a 50x objective lens. This confocal microscope may be useful for analyzing fast phenomena during biological and chemical interactions and for fast 3D image reconstruction.

Im, Kang-Bin; Han, Sumin; Park, Hwajoon; Kim, Dongsun; Kim, Beop-Min

2005-06-01

278

Confocal shift interferometry of coherent emission from trapped dipolar excitons  

NASA Astrophysics Data System (ADS)

We introduce a confocal shift-interferometer based on optical fibers. The presented spectroscopy allows measuring coherence maps of luminescent samples with a high spatial resolution even at cryogenic temperatures. We apply the spectroscopy onto electrostatically trapped, dipolar excitons in a semiconductor double quantum well. We find that the measured spatial coherence length of the excitonic emission coincides with the point spread function of the confocal setup. The results are consistent with a temporal coherence of the excitonic emission down to temperatures of 250 mK.

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

2014-12-01

279

Optimization of confocal laser induced fluorescence in a plasma  

NASA Astrophysics Data System (ADS)

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

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

2014-11-01

280

Optimization of confocal laser induced fluorescence in a plasma.  

PubMed

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

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

2014-11-01

281

Confocal Raman imaging of crystalline an glassy materials  

SciTech Connect

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

Bradley, N.L.; Morris, M.D. [Univ. of Michigan, Ann Arbor, MI (United States)

1995-12-31

282

Confocal Raman microscopy for identification of bacterial species in biofilms  

NASA Astrophysics Data System (ADS)

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

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

2011-03-01

283

A Pico Projector Source for Confocal Fluorescence and Ophthalmic Imaging  

PubMed Central

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

Muller, Matthew S.

2013-01-01

284

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

285

Structural and elemental X-ray microanalysis with synchrotron radiation in confocal geometry  

NASA Astrophysics Data System (ADS)

A spectrometer for 3D structural and multielemental X-ray microanalysis with synchrotron radiation is presented in this work. It is based on the combination of the energy dispersive X-ray fluorescence and diffraction with polycapillary optics. The 3D spatial resolution was achieved by the superposition of the foci of two lenses arranged in confocal geometry. The parameters that affect the performance of the spectrometer were study in detail giving rise to a simplified calibration method for depth profile analysis. Two specific examples were included to illustrate the use of the spectrometer in order to identify their possible application fields.

Sosa, Carlos M.; Sánchez, H. Jorge; Pérez, Carlos A.; Perez, Roberto D.

2014-01-01

286

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. PMID:22606422

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

2011-01-01

287

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

NASA Astrophysics Data System (ADS)

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

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

2012-05-01

288

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

289

Confocal Laser Microscope Scanning Applied To Three-Dimensional Studies Of Biological Specimens.  

NASA Astrophysics Data System (ADS)

The depth-discriminating property of confocal laser microscope scanners can be used to record the three-dimensional structure of specimens. A number of thin sections (approx. 1 ?m thick) can be recorded by a repeated process of image scanning and refocusing of the microscope. We have used a confocal microscope scanner in a number of feasibility studies to investigate its possibilities and limitations. It has proved to be well suited for examining fluorescent specimens with a complicated three-dimensional structure, such as nerve cells. It has also been used to study orchid seeds, as well as cell colonies, greatly facilitating evaluation of such specimens. Scanning of the specimens is performed by a focused laser beam that is deflected by rotating mirrors, and the reflected or fluorescent light from the specimen is detected. The specimen thus remains stationary during image scanning, and is only moved stepwise in the vertical direction for refocusing between successive sections. The scanned images consist of 256*256 or 512*512 pixels, each pixel containing 8 bits of data. After a scanning session a large number of digital images, representing consecutive sections of the specimen, are stored on a disk memory. In a typical case 200 such 256*256 images are stored. To display and process this information in a meaningful way requires both appropriate software and a powerful computer. The computer used is a 32-bits minicomputer equipped with an array processor (FPS 100). The necessary software was developed at our department.

Franksson, Olof; Liljeborg, Anders; Carlsson, Kjell; Forsgren, Per-Ola

1987-08-01

290

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

291

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

PubMed Central

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

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

2012-01-01

292

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

293

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

PubMed

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

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

2014-11-01

294

Segmentation of confocal microscopic image of insect brain  

Microsoft Academic Search

Accurate analysis of insect brain structures in digital confocal microscopic images is valuable and important to biology research needs. The first step is to segment meaningful structures from images. Active contour model, known as snakes, is widely used for segmentation of medical images. A new class of active contour model called gradient vector flow snake has been introduced in 1998

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

2002-01-01

295

CONFOCAL MICROWAVE IMAGING FOR BREAST TUMOUR DETECTION: PRACTICAL FEASIBILITY  

Microsoft Academic Search

Confocal Microwave Imaging (CMI) (1-4) is slowly progressing from the theoretical stage involving extensive simulations to experimental feasibility studies. Two aspects need to be addressed: (i) the practical capability of CMI to detect tissue abnormalities, and (ii) verification of the hypothesis that large contrast exists between electrical parameters of breast cancer and normal breast tissue. In this paper we present

M. Okoniewski; D. Popovic

296

Parametric Blind Deconvolution for Confocal Laser Scanning Microscopy  

Microsoft Academic Search

In this paper, we propose a method for the iterative restoration of fluorescence confocal laser scanning microscopic (CLSM) images and parametric estimation of the acquisition system's point spread function (PSF). The CLSM is an optical fluorescence microscope that scans a specimen in 3D and uses a pinhole to reject most of the out-of-focus light. However, the quality of the images

Praveen Pankajakshan; Bo Zhang; L. Blanc-Feraud; Zvi Kam; Jean-Christophe Olivo-Marin; Josiane Zerubia

2007-01-01

297

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

298

INTRODUCTION The advent of confocal microscopy for imaging dynamic  

E-print Network

- dritic spines [2]. A key feature of any confocal microscope used for these purposes is that it must provide good time resolution (a few tens of ms or better). Most commercial instruments are, however of the BioRad RTS2000 MP system, no com- mercial instruments were available that permitted `real- time' frame

Parker, Ian

299

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

EPA Science Inventory

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

300

CONFOCAL MICROSCOPY SYSTEM PERFORMANCE: SPECTROSCOPY AND FOUNDATIONS FOR QUANTITATION  

EPA Science Inventory

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

301

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

EPA Science Inventory

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

302

Black Widow Leica DMRXA Spinning Disk Confocal Microscope  

E-print Network

Black Widow Leica DMRXA Spinning Disk Confocal Microscope User Guide v. 1.3 (11 of the microscope 16 APPENDIX C ­ Factors that Affect Quality of Digital Images 17 Exposure time Bit depth are at all unsure of this process, ask for help! 8) Leave the microscope on a low power objective for next

Pace, Norman

303

Zeiss LSM 510 Laser Scanning Confocal Microscope User Guide  

E-print Network

Iron Man Zeiss LSM 510 Laser Scanning Confocal Microscope User Guide v. 1.3 (11 of the microscope 13 APPENDIX C ­ Configuring the Light Path 14 #12;Iron Man User Guide v. 1.3 3 Quick) Leave the microscope on a low power objective for next user. If someone is signed up within

Pace, Norman

304

Optical Reflectance Of Metallic Coatings: Effect Of Aluminum Flake Orientation  

Microsoft Academic Search

A set of aluminum-flake pigmented coatings having different flake orientations was pre- pared using various spray conditions. The orientations of individual flakes were determined from images obtained by laser scanning confocal microscopy. Reflectance measurements were carried out to quantify the optical properties of the coatings. A Gaussian orientation distribution or topographic map of the flakes was then used as input

Li-Piin Sung; Maria E. Nadal; Mary E. McKnight; Egon Marx; Brent Laurenti

2001-01-01

305

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

306

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

NASA Astrophysics Data System (ADS)

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

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

2008-10-01

307

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. PMID:22029364

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

2011-01-01

308

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

309

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

NASA Astrophysics Data System (ADS)

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

Zhang, Yanyan; Zhou, Changhe

2005-02-01

310

X-ray resonant magnetic reflectivity of stratified magnetic structures: Eigenwave formalism and application to a W/Fe/W trilayer  

NASA Astrophysics Data System (ADS)

A formalism for the reflectivity of electromagnetic waves by magnetic materials is presented with an application. It is applied to retrieve the magnetic moment density along the depth of magnetic materials with arbitrary magnetic moment direction using matricial algebra, including roughness between layers. The reflectivity is derived following a classical description with Maxwell equations and a permittivity built from the quantum scattering amplitude. Approximations on the relative power of the Thomson scattering and the magnetic terms are trackable in order to evaluate the validity of the formalism case-by-case, from the optical light regime up to soft and hard X-rays. Eigenwaves are used throughout the whole formalism. In order to illustrate the methodology, we present an application to a W/Fe/W trilayer performed at the Fe L-edge, in the soft X-ray regime.

Elzo, M.; Jal, E.; Bunau, O.; Grenier, S.; Joly, Y.; Ramos, A. Y.; Tolentino, H. C. N.; Tonnerre, J. M.; Jaouen, N.

2012-01-01

311

APPLICATIONS OF LASERS AND OTHER TOPICS IN QUANTUM ELECTRONICS: Enhancement of the reflectivity of beryllium oxide in the middle infrared  

NASA Astrophysics Data System (ADS)

An analysis is made of the feasibility of enhancing the reflectivity of BeO-based materials in the middle infrared. It is shown that the deposition of a Ge film 0.8 ?m thick on a BeO single crystal makes it possible to achieve a reflection coefficient of 0.992 at ? = 10.6 ?m. When Ge films of thickness d>=0.3 ?m are deposited on a BeO ceramic, the upper limit of the existence of surface polaritons is shifted to the low-frequency part of the spectrum, thereby eliminating their excitation by CO2 laser radiation and making the reflection coefficient of the ceramic similar to that of single-crystal BeO.

Belyanko, A. E.; Bykovski?, Yu A.; Karapuzikov, A. I.; Lipatov, N. I.; Sakhanova, V. V.

1989-01-01

312

Reflective Creativity  

Microsoft Academic Search

Almost more than acts of creativity in education the act of reflection holds within itself seeds of change and transformation. As Donald Schön (1991) has pointed out, by exploring the patterns of spontaneous activity that make up practice, and believing there is an underlying sense to be discovered, teachers are led to reflect on their own understandings and the theoretical

Mary Hilton

313

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

NASA Astrophysics Data System (ADS)

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 image reconstructions of confocal z-scans through giant unilamellar vesicles reveal the anisotropic morphology of coexisting phase domains on the surface of these vesicles with full two-dimensional resolution. This method demonstrates by direct visualization the exact superposition of like phase domains in apposing monolayers, thus answering a long-standing open question. Cholesterol was found to induce a marked change in the phase boundary shapes of the coexisting phase domains. To further characterize the phases, the translational diffusion coefficient DT of the DiI-C20 was measured by FCS. DT values at ~ 25 degrees C ranged from ~ 3× 10-8 cm2/s in the fluid phase, to ~ 2× 10-9 cm2/s in high-cholesterol-content phases, to ~ 2× 10-10 cm2/s in the spatially ordered phases that coexist with fluid phases. In favorable cases, FCS could distinguish two different values of DT in a region of two-phase coexistence on a single vesicle.

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

1999-07-01

314

Confocal near-membrane detection of calcium in cardiac myocytes.  

PubMed

Near-membrane [Ca2+] may differ significantly from bulk cytosolic [Ca2+], particularly during rapid Ca2+ signalling events related to cardiac muscle excitation-contraction coupling. We used the lipophilic membrane-associated Ca2+ indicator Ca(2+)-Green C-18 (C-18) and laser-scanning confocal microscopy to detect extracellular [Ca2+] and changes of t-tubular [Ca2+] in cultured neonatal rat myocytes and in freshly isolated adult guinea pig ventricular myocytes. Changes of extracellular [Ca2+] were readily detected by the C-18 located in the cell membrane. Control experiments were carried out with 100 mM extracellular nickel to rapidly quench the fluorescent indicator accessible form the extracellular space. After exposure to Ni2+, C-18 fluorescence was lower than measured in Ca(2+)-free conditions indicating that C-18 was located in the outer leaflet of the cell membrane. In contrast, the lipophilic derivative of Indo-1 (FIP-18) was significantly internalized, as visualized using two-photon excitation of FIP-18. Surprisingly, in low extracellular [Ca2+], C-18 located in the outer leaflet of the cell membrane also reported transient elevations of intracellular [Ca2+] during application of 10 mM caffeine. In the absence of extracellular Na+ to inhibit Ca2+ removal via Na/Ca exchange, the intracellular Ca2+ signals evoked by caffeine were prolonged, as recorded with Fura-Red. However, the near-membrane Ca2+ signal simultaneously detected by C-18 did not increase during caffeine stimulation in the absence of extracellular Na+. These results suggest that the C-18 signal reports extrusion of cytosolic Ca2+ from the subsarcolemmal space mediated by Na/Ca exchange. C-18 was also used to analyze the extracellular accessibility of the t-tubular lumen in isolated guinea pig ventricular myocytes. After stepwise increases of [Ca2+]o with a rapid superfusion device, a wave-like Ca2+ gradient travelled along the t-tubules at a velocity of 3.4-16.3 microns/s. The solution change within the t-tubules was delayed by 0.63-2.3 s and wash-out of Ca2+ from the t-tubules slowed from t1/2 = 0.9 s at the surface to 1.7 s in deeper regions of the t-tubular system. This slow exchange of the solution within the t-tubules, lasting several seconds, may give rise to spatially inhomogeneous accumulation and/or depletion resulting from ion fluxes across the t-tubular membrane during physiological activity. PMID:9681190

Blatter, L A; Niggli, E

1998-05-01

315

Reflective array SAW narrowband filters  

Microsoft Academic Search

Experimental results are presented for a reflective-array SAW (surface acoustic wave) device that is optimized for narrowband filter applications. The filter consists of broadband input and output transducers with two weighted reflector arrays. Previous devices of this type have used reflective dot density and depth profile weighting for the reflective arrays. A unique implementation of this design technique for a

S. Gopani; R. B. Brown; J. H. Hines; B. H. Horine

1990-01-01

316

Opposite effects of two different strains of equine herpesvirus 1 infection on cytoskeleton composition in equine dermal ED and African green monkey kidney Vero cell lines: application of scanning cytometry and confocal-microscopy-based image analysis in a quantitative study.  

PubMed

Viruses can reorganize the cytoskeleton and restructure the host cell transport machinery. During infection viruses use different cellular cues and signals to enlist the cytoskeleton for their mission. However, each virus specifically affects the cytoskeleton structure. Thus, the aim of our study was to investigate the cytoskeletal changes in homologous equine dermal (ED) and heterologous Vero cell lines infected with either equine herpesvirus 1 (EHV-1) strain Rac-H or Jan-E. We found that Rac-H strain disrupted actin fibers and reduced F-actin level in ED cells, whereas the virus did not influence Vero cell cytoskeleton. Conversely, the Jan-E strain induced polymerization of both F-actin and MT in Vero cells, but not in ED cells. Confocal-microscopy analysis revealed that alpha-tubulin colocalized with viral antigen in ED cells infected with either Rac-H or Jan-E viruses. Alterations in F-actin and alpha-tubulin were evaluated by confocal microscopy, Microimage analysis and scanning cytometry. This unique combination allowed precise interpretation of confocal-based images showing the cellular events induced by EHV-1. We conclude that examination of viral-induced pathogenic effects in species specific cell lines is more symptomatic than in heterologous cell lines. PMID:20349252

Turowska, A; Pajak, B; Godlewski, M M; Dzieciatkowski, T; Chmielewska, A; Tucholska, A; Banbura, M

2010-05-01

317

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...

318

APPLICATIONS OF LASERS AND OTHER TOPICS IN QUANTUM ELECTRONICS: Linearization of reflection by a hypersonic phase-conjugation mirror  

NASA Astrophysics Data System (ADS)

It is shown the dynamic signal energy range within which the reflection coefficient of a phase-conjugation mirror (in a four-wave mixing system with a strong signal wave) remains constant at 40%, can be increased to 5.5 orders of magnitude.

Efimkov, V. F.; Zubarev, I. G.; Kolobrodov, V. V.; Pastukhov, S. A.; Sobolev, V. B.

1988-10-01

319

Application of Near Infrared Reflectance Spectroscopy on Determination of Moisture, Total oil and Protein Contents of In-shell Peanuts  

Technology Transfer Automated Retrieval System (TEKTRAN)

Moisture, total oil and protein content of peanuts are important factors in peanut grading. A method that could rapidly and nondestructively measure these parameters for in-shell peanuts would be extremely useful. NIR reflectance spectroscopy was used to analyze the moisture, total oil and protein ...

320

Visualisation and modelling of renal capillaries from confocal images.  

PubMed

A computer aided design was developed to support three-dimensional visualisation and modelling of vascular networks. Volume data comprised a series of images obtained using a Zeiss confocal laser scanning microscope. The profiles of vessels were automatically segmented using two-dimensional morphological filters. Segmented contours of the vessels were used to form a spatial model of the network. The centre points of segmented contours were used to derive a three-dimensional graph representing the vascular network. The proposed method was applied to renal capillary networks of normal rats, and showed well the lobular structure of glomeruli. The average length of renal capillary networks was 6.09 mm. Three-dimensional models based on confocal data require much less effort than reconstructions based on serial sections, and can be adapted for any vascular patterns. PMID:10505374

Kaczmarek, E

1999-05-01

321

Automated spherical aberration correction in scanning confocal microscopy  

NASA Astrophysics Data System (ADS)

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

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

2014-12-01

322

High-speed line scanning confocal microscope for biological imaging  

NASA Astrophysics Data System (ADS)

We constructed a high-speed laser line-scanning confocal microscope (LSCM) using He-Ne laser (633 nm), a line CCD camera, and an acousto-optic deflector (AOD). The line scanner consists of an AOD and a cylindrical lens, which create a line focus sweeping over the sample. The line scanner generates two-dimensional confocal images (512× 512 pixel image) up to 191 frames per second with no mechanically-moving parts. This system is configured as an inverted microscope for imaging biological organisms or tissues. Images of various biological samples were obtained including rabbit cornea, onion cells, mouse melanoma tumor cells (B16BL6), and human breast tumor cells (BT-20). The frame rate may be further improved up to over 700 frames per second when the image size is reduced (512×128 pixel image). This system may be useful for analyzing fast phenomena during biological and chemical interactions and for imaging 3D structures rapidly.

Jung, Seung-Hwan; Kim, Chang-Keun; Ju, Sung-Bin; Cho, Yong-Jin; Jeong, Hyun-Woo; Kim, Beop-Min

2007-02-01

323

Automated spherical aberration correction in scanning confocal microscopy.  

PubMed

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

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

2014-12-01

324

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

NASA Astrophysics Data System (ADS)

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

Qiu, Le

325

GFP fluorescence imaging with laser confocal scanning microscope  

NASA Astrophysics Data System (ADS)

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

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

1999-09-01

326

A surgical confocal microlaparoscope for real-time optical biopsies  

NASA Astrophysics Data System (ADS)

The first real-time fluorescence confocal microlaparoscope has been developed that provides instant in vivo cellular images, comparable to those provided by histology, through a nondestructive procedure. The device includes an integrated contrast agent delivery mechanism and a computerized depth scan system. The instrument uses a fiber bundle to relay the image plane of a slit-scan confocal microlaparoscope into tissue. The confocal laparoscope was used to image the ovaries of twenty-one patients in vivo using fluorescein sodium and acridine orange as the fluorescent contrast agents. The results indicate that the device is safe and functions as designed. A Monte Carlo model was developed to characterize the system performance in a scattering media representative of human tissues. The results indicate that a slit aperture has limited ability to image below the surface of tissue. In contrast, the results show that multi-pinhole apertures such as a Nipkow disk or a linear pinhole array can achieve nearly the same depth performance as a single pinhole aperture. The model was used to determine the optimal aperture spacing for the multi-pinhole apertures. The confocal microlaparoscope represents a new type of in vivo imaging device. With its ability to image cellular details in real time, it has the potential to aid in the early diagnosis of cancer. Initially, the device may be used to locate unusual regions for guided biopsies. In the long term, the device may be able to supplant traditional biopsies and allow the surgeon to identify early stage cancer in vivo.

Tanbakuchi, Anthony Amir

327

Quantification of Multilayer Samples by Confocal {mu}XRF  

SciTech Connect

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

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

2009-01-29

328

Simultaneous multiplane confocal microscopy using acoustic tunable lenses.  

PubMed

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

Duocastella, Martí; Vicidomini, Giuseppe; Diaspro, Alberto

2014-08-11

329

Feasibility of confocal fluorescence microscopy for real-time evaluation of neoplasia in fresh human breast tissue.  

PubMed

Breast cancer management could be improved by developing real-time imaging tools to assess tissue architecture without extensive processing. We sought to determine whether confocal fluorescence microscopy (CFM) provides sufficient information to identify neoplasia in breast tissue. Breast tissue specimens were imaged following proflavine application. Regions of interest (ROIs) were selected in histologic slides and in the corresponding region on confocal images, and then divided into sets for training and validation. Readers reviewed images in the training set and evaluated images in the validation set for the presence of neoplasia. Accuracy was assessed using histologic diagnosis as the gold standard. Seventy tissue specimens from 31 patients were imaged; 235 ROIs were identified and diagnosed as neoplastic or non-neoplastic. A training set was assembled using 23 matched ROIs; 49 matched ROIs were assembled into a validation set. Neoplasia was identified in histologic images: 93% sensitivity, 97% specificity [area under the curve (AUC=0.987)] and in confocal images: 93% sensitivity 93% specificity (AUC=0.957). CFM produced images of architectural features in breast tissue comparable with conventional histology, while requiring little processing. Potential applications include assessment of excised tissue margins and evaluation of tissue adequacy for bio-banking and genomic studies. PMID:24165742

Dobbs, Jessica L; Ding, Hao; Benveniste, Ana Paula; Kuerer, Henry M; Krishnamurthy, Savitri; Yang, Wei; Richards-Kortum, Rebecca

2013-10-01

330

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

NASA Astrophysics Data System (ADS)

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

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

2013-06-01

331

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

PubMed Central

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

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

2008-01-01

332

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

NASA Astrophysics Data System (ADS)

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

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

2014-03-01

333

A preliminary assessment of using a white light confocal imaging profiler for cut mark analysis.  

PubMed

White light confocal microscopy creates detailed 3D representations of microsurfaces that can be qualitatively and quantitatively analyzed. The study describes its application to the analysis of cut marks on bone, particularly when discerning cuts made by steel tools from those made by stone. The process described comes from a study where cuts were manually made on a cow rib with seven cutting tools, four stone (an unmodified chert flake, a chert biface, a bifacially ground slate fragment, and an unsharpened piece of slate), and three steel (a Swiss Army Knife, a serrate steak knife, and a serrate saw). Kerfs were magnified ×20 and 3D data clouds were generated using a Sensofar(®) White Light Confocal Profiler (WLCP). Kerf profiles and surface areas, volumes, mean depths, and maximum depths were calculated with proprietary software (SensoScan(®) and SolarMap(®)). For the most part, the stone tools make shallower and wider cuts. Kerf floors can be studied at higher magnifications; they were viewed at ×100. When comparing the kerf floors of the unsharpened slate and the serrate steak knife it was found that the slate floor was more uneven, but the serrate steak knife generated more overall relief. Although preliminary, the approach described here successfully distinguishes stone and steel tools; the authors conclude that the WLCP is a promising technology for cut mark analysis because of the very detailed 3D representations it creates and the numerous avenues of analysis it provides. PMID:22907412

Schmidt, Christopher W; Moore, Christopher R; Leifheit, Randell

2012-01-01

334

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

335

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

E-print Network

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

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

2008-01-01

336

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

337

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

NASA Technical Reports Server (NTRS)

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

Nash, D. B.

1987-01-01

338

A new histochemical double-stain method using three-dimensional analysis with confocal laser scanning microscopy.  

PubMed

We describe a new technique for immunohistochemical and enzyme-histochemical double staining using confocal laser scanning microscopy in the reflection mode. As an example, we investigated the immunoreactivity for Spot 35-calbindin-D28K, a vitamin D-dependent calcium binding protein, and the enzyme activity for Ca(2+)-ATPase in the rat kidney. The lead precipitation method for Ca(2+)-ATPase was initially used to process kidney slices. Each specimen was then dehydrated and embedded in a water soluble resin. Thin sections were cut from the resin block, and an indirect immunocolloidal gold method with silver enhancement for Spot 35-calbindin-D28K antigen was carried out on the glass slides. Results were then observed by confocal laser scanning microscopy in the reflection mode. The three-dimensional distribution of the reaction products was detected by serial optic slice images. Lead phosphate particles, which represented the location of Ca(2+)-ATPase, were distributed deep in the section. The most intense signals from the silver particles were detected from the surface slice of the section. A stereoscopic image generated from the serial optic slices clearly showed the differences in their distribution. PMID:7535568

Kazama, J J; Aikata, T; Arakawa, M; Ozawa, H

1994-11-01

339

Simulation of X-ray diffraction profiles in multilayers by direct wave summation: Application to asymmetric reflections  

NASA Astrophysics Data System (ADS)

A novel algorithm for the simulation of the X-ray diffraction profiles in multilayers is developed, which can be applied to any multilayered structure, with no limitations. The simulation program in the MATLAB format is based on the direct summation of waves scattered by individual atomic planes. It takes into account the strain and concentration-induced fluctuations of interplanar spacings, interface roughness and buried amorphous layers, and enables adding the diffuse scattering contributions of the Gaussian or Lorentzian types. The summation over individual layers can be done coherently or incoherently, depending on the interface structure. In order to visualize the steps of the fitting procedure, the contribution of each layer can be plotted separately. In this paper the simulation routine is described with a focus on handling asymmetric reflections. We stress that in this case, the effective thickness of the layers, participating in the formation of diffraction signals, can be very different for low or high X-ray incidence angles. We also show that in contrast to symmetric reflections, when treating the asymmetric ones, an additional phase shift depending on the distance between the sample and detector, should be taken into account. The simulation program is applied to fit experimental diffraction profiles, symmetric and asymmetric, taken from the MOVPE-grown heterostructures and superlattices of practical importance, based on the InGaAsP/InP materials system.

Zamir, S.; Steinberg, O.; Lakin, E.; Zolotoyabko, E.

2006-10-01

340

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

PubMed

Indium tin oxide (ITO) and titanium dioxide (TiO2) anti-reflective coatings (ARCs) were deposited on a (100) P-type monocrystalline Si substrate by a radio-frequency (RF) magnetron sputtering. Polycrystalline ITO and anatase TiO2 films were obtained at room temperature (RT). The thickness of ITO (60 to 64 nm) and TiO2 (55 to 60 nm) films was optimized, considering the optical response in the 400- to 1,000-nm wavelength range. The deposited films were characterized by X-ray diffraction (XRD), Raman spectroscopy, field emission scanning electron microscopy (FESEM), energy dispersive spectroscopy (EDS), and atomic force microscopy (AFM). The XRD analysis showed preferential orientation along (211) and (222) for ITO and (200) and (211) for TiO2 films. The XRD analysis showed that crystalline ITO/TiO2 films could be formed at RT. The crystallite strain measurements showed compressive strain for ITO and TiO2 films. The measured average optical reflectance was about 12% and 10% for the ITO and TiO2 ARCs, respectively. PMID:24721986

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

2014-01-01

341

Reflecting Squarely  

NSDL National Science Digital Library

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

2009-04-01

342

Blind deconvolution for thin-layered confocal imaging.  

PubMed

We propose an alternate minimization algorithm for estimating the point-spread function (PSF) of a confocal laser scanning microscope and the specimen fluorescence distribution. A three-dimensional separable Gaussian model is used to restrict the PSF solution space and a constraint on the specimen is used so as to favor the stabilization and convergence of the algorithm. The results obtained from the simulation show that the PSF can be estimated to a high degree of accuracy, and those on real data show better deconvolution as compared to a full theoretical PSF model. PMID:19649049

Pankajakshan, Praveen; Zhang, Bo; Blanc-Féraud, Laure; Kam, Zvi; Olivo-Marin, Jean-Christophe; Zerubia, Josiane

2009-08-01

343

A coherent model for turbid imaging with confocal microscopy  

PubMed Central

We present an engineering model of coherent imaging within a turbid volume, such as human tissues, with a confocal microscope. The model is built to analyze the statistical effect of aberrations and multiply scattered light on the resulting image. Numerical modeling of theory is compared with experimental results. We describe the construction of a stable phantom that represents the statistical effect of object turbidity on the image recorded. The model and phantom can serve as basis for system optimization in turbid imaging. PMID:23577285

Glazowski, Christopher E.; Zavislan, James

2013-01-01

344

A miniature confocal Raman probe for endoscopic use  

NASA Astrophysics Data System (ADS)

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

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

2009-12-01

345

Confocal Imaging of Biological Tissues Using Second Harmonic Generation  

SciTech Connect

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

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

2000-03-06

346

Application of reflectance spectroscopy to the estimation of uric acid, urea and glucose: an evaluation of the Ames Seralyzer  

PubMed Central

An original approach to the measurement of analytes in clinical chemistry has now become available, in which dry reagent strip technology is linked to measurement by reflectance spectroscopy. The present studies have evaluated the performance of the first of these test systems—for uric acid, urea and glucose, in serum—by comparison with conventional liquid chemistry methods. Satisfactory performance in terms of both precision and accuracy was obtained for all three test systems, the current “state-of-the-art” performance criteria being met; the Seralyzer system proved reliable and easy to use in the hands of trained operators. It should find a place as a “Stat” analyser in the laboratory, in specified wards and in Health Centres. PMID:6822683

Stevens, JF; Newall, RG

1983-01-01

347

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

NASA Technical Reports Server (NTRS)

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

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

2007-01-01

348

MEMS-based handheld confocal microscope for in-vivo skin imaging  

PubMed Central

This paper describes a handheld laser scanning confocal microscope for skin microscopy. Beam scanning is accomplished with an electromagnetic MEMS bi-axial micromirror developed for pico projector applications, providing 800x600 (SVGA) resolution at 56 frames per second. The design uses commercial objective lenses with an optional hemisphere front lens, operating with a range of numerical aperture from NA=0.35 to NA=1.1 and corresponding diagonal field of view ranging from 653 ?m to 216 ?m. Using NA=1.1 and a laser wavelength of 830 nm we measured the axial response to be 1.14 ?m full width at half maximum, with a corresponding 10%-90% lateral edge response of 0.39 ?m. Image examples showing both epidermal and dermal features including capillary blood flow are provided. These images represent the highest resolution and frame rate yet achieved for tissue imaging with a MEMS bi-axial scan mirror. PMID:20389391

Arrasmith, Christopher L.; Dickensheets, David L.; Mahadevan-Jansen, Anita

2010-01-01

349

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

SciTech Connect

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

Shafir, E.; Berkovic, G

2006-10-20

350

Visualization and analysis techniques for three dimensional information acquired by confocal microscopy.  

PubMed

Confocal Scanning Laser Microscopy (CSLM) is particularly well suited for the acquisition of 3-dimensional data of microscopic objects. In the CSLM a specific volume in the object is sampled during the imaging process and the result is stored in a digital computer as a three-dimensional memory array. Optimal use of these data requires both the development of effective visual representations as well as analysis methods. In addition to the well known stereoscopic representation method a number of alternatives for various purposes are presented. When rendering in terms of solid-looking or semitransparent objects is required, an algorithm based on a simulated process of excitation and fluorescence is very suitable. Graphic techniques can be used to examine the 3-dimensional shape of surfaces. For (near-)real time applications a representation method should not require extensive previous data-processing or analysis. From the very extensive field of 3-D image analysis two examples are given. PMID:3238377

Brakenhoff, G J; van der Voort, H T; Baarslag, M W; Mans, B; Oud, J L; Zwart, R; van Driel, R

1988-12-01

351

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

PubMed

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

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

2013-01-01

352

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

NASA Astrophysics Data System (ADS)

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

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

2014-09-01

353

Optical axial scanning in confocal microscopy using an electrically tunable lens  

PubMed Central

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

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

2014-01-01

354

Embryonic heart morphogenesis from confocal microscopy imaging and automatic segmentation.  

PubMed

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

Mao, Hongda; Gribble, Megan; Pertsov, Arkady M; Shi, Pengcheng

2013-01-01

355

Limitations on optical sectioning in live-cell confocal microscopy.  

PubMed

In three-dimensional (3-D) live-cell microscopy, it has been common to treat cells as having a constant refractive index (RI). Although the variations in RI associated with the nucleus and other organelles were recognized from phase- and differential interference contrast (DIC) images, it was assumed that they were small and would not affect 3-D fluorescence images obtained using widefield/deconvolution, confocal of multiphoton imaging. This paper makes clear that this confidence was misplaced. Confocal images made using backscattered light (BSL) to image the flat, glass/water interfaces above and below living microscope specimens should reveal these structures as flat and featureless. That the image of the interface on the far side of the cells is neither flat nor featureless indicates that the "optical section" surface can be profoundly distorted by the RI irregularities associated with the presence of nuclei and other subcellar structures. This observation calls into question the reliability of images made using any of the current methods for performing 3-D light microscopy of living cells. PMID:12392355

Pawley, James B

2002-01-01

356

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

SciTech Connect

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

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

2012-06-01

357

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

PubMed

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

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

2013-06-01

358

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

NASA Astrophysics Data System (ADS)

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

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

2009-08-01

359

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

360

The application of Near-Infrared Reflectance Spectroscopy (NIRS) to detect melamine adulteration of soya bean meal.  

PubMed

Soya bean products are used widely in the animal feed industry as a protein based feed ingredient and have been found to be adulterated with melamine. This was highlighted in the Chinese scandal of 2008. Dehulled soya (GM and non-GM), soya hulls and toasted soya were contaminated with melamine and spectra were generated using Near Infrared Reflectance Spectroscopy (NIRS). By applying chemometrics to the spectral data, excellent calibration models and prediction statistics were obtained. The coefficients of determination (R(2)) were found to be 0.89-0.99 depending on the mathematical algorithm used, the data pre-processing applied and the sample type used. The corresponding values for the root mean square error of calibration and prediction were found to be 0.081-0.276% and 0.134-0.368%, respectively, again depending on the chemometric treatment applied to the data and sample type. In addition, adopting a qualitative approach with the spectral data and applying PCA, it was possible to discriminate between the four samples types and also, by generation of Cooman's plots, possible to distinguish between adulterated and non-adulterated samples. PMID:23194562

Haughey, Simon A; Graham, Stewart F; Cancouët, Emmanuelle; Elliott, Christopher T

2013-02-15

361

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

NASA Astrophysics Data System (ADS)

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

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

2014-11-01

362

Plant stress analysis: Application of prompt, delayed chlorophyll fluorescence and 820 nm modulated reflectance. Insights from independent experiments.  

PubMed

Nine short-term independent studies were carried out with two M-PEA units on several plant species differing in their functional traits (woody evergreen, woody deciduous, herbaceous) and exposed to different kind of abiotic stress (drought, salt, ozone, UV radiation). Aim of the study is to check the consistency of plant responses, assessed through three sets of simultaneously measured signals: Prompt Fluorescence (PF), Delayed Fluorescence (DF) and Modulated Reflectance of 820 nm light (MR). The decrease of FV/FM and F0, the increase of VJ and VI were the most common responses related to PF parameters. The decrease of vox and vred as well the increase of MRmin were common response of MR. DF showed species-treatment specific behaviours. The Principal Component Analysis (PCA) suggests that the combination of PF and MR parameters represents a powerful tool for plant stress phenotyping, whereas MR parameters are linked to physiological strategies, related to different functional groups, to cope with stress factors. PMID:25463266

Salvatori, Elisabetta; Fusaro, Lina; Gottardini, Elena; Pollastrini, Martina; Goltsev, Vasilij; Strasser, Reto J; Bussotti, Filippo

2014-11-01

363

Phonon Reflection in Silicon.  

NASA Astrophysics Data System (ADS)

An experiment using heat pulses has been performed to study phonon reflection at a silicon-vacuum interface. The phonons are generated by sending a voltage pulse of 40 to 160 ns duration through a thin film constantan heater. The resultant power densities in the heater range from about 25 to 40000 mW/mm('2), corresponding to phonon frequencies in the hundreds of gigahertz. The phonons propagate ballistically across the silicon single crystal and reflect or scatter at the opposite surface. Upon their return to the surface where they were generated, some of them are detected by a superconducting tin bolometer, producing what is called a time of flight spectrum. This spectrum can be analyzed by comparing it to linear combinations of the spectra predicted by two models; one assuming that the phonons are specularly reflected with conservation of the component of the wave vector lying parallel to the surface, the other assuming that they are scattered randomly back into the crystal. The particular linear combination that most closely approximates the experimental spectrum defines the percentage of the incident energy said to be specularly reflected. The reflecting surface was polished with 1(mu) diamond paste or with a chemi-mechanical silica sol (Syton). In addition, the oxide layer that forms on silicon on contact with air was altered by stripping and reformation in basic and acidic peroxide solutions and by HF etching. In some cases it was possible to retain the same thin film devices while varying the reflecting surface preparation, thus allowing absolute comparison of the spectra for the differently prepared surfaces. Results support the applicability of the weighted model described above. In addition, it has been found that the character of the oxide layer strongly affects the reflecting properties of the surface. For example, cleaning with peroxide solutions decreases the fraction of phonons which are specularly reflected, whereas HF etching increases it.

Throwe, Jane B.

364

Contact lens-induced changes in the anterior eye as observed in vivo with the confocal microscope.  

PubMed

The availability of the confocal microscope over the past decade has allowed clinicians and researchers to refine their understanding of the physiological and pathological basis of the ocular response to contact lens wear, and to discover previously unknown phenomena. Mucin balls, which form in the tear layer in patients wearing silicone hydrogel lenses, can penetrate the full thickness of the epithelium, leading to activation of keratocytes in the underlying anterior stroma. Epithelial cell size increases in response to all forms of lens wear, with lenses of higher oxygen transmissibility (Dk/t) interfering least with the normal process of epithelial desquamation. A higher density of Langerhans' cells is observed in the layer of the sub-basal nerve plexus among contact lens wearers, suggesting that contact lens wear may be altering the immune status of the cornea. Dark lines and folds are observed in the oedematous cornea in response to contact lens wear. Mechanical stimulation of the corneal surface, due to the physical presence of a contact lens, and the consequent release of inflammatory mediators, is the likely cause of reduced keratocyte density associated with lens wear. Highly reflective stromal 'microdot deposits' are observed throughout the entire stroma in higher numbers in lens wearers. 'Blebs' in the endothelium have a bright centre surrounded by a dark annular shadow; this appearance is explained with the aid of an optical model. The confocal microscope has considerable clinical utility in diagnosing Acanthamoeba and fungal keratitis. At the limbus, contact lenses can induce structural changes such as increases in basal epithelial cell size. An increased number of rolling leucocytes is observed in limbal vessels in response to low Dk/t lenses. It is concluded that the confocal microscope has considerable utility in contact lens research and practice. PMID:17498998

Efron, Nathan

2007-07-01

365

Modeling the reflectance of CO2 frost with new optical constants: Application to Martian south polar cap spectra  

NASA Technical Reports Server (NTRS)

New measurements of the absorption coefficients of CO2 ice, in most of the spectral range 0.2 to 3.9 microns where absorption coefficients are below 1.5 per cm, have recently been made. Although these measurements are preliminary, they contain spectral detail not seen previously in the literature. Therefore, it is useful to combine these new data with older data from spectral regions of stronger absorption and reformulate models of the albedo or reflectance of CO2 frost. These models can then be adjusted in an attempt to match measurements of Martian polar deposits, such as the set of spectra returned by the IRS instrument on Mariner 7 (1969). The new absorption coefficients of CO2 ice were measured on several samples of 41-mm thickness at 150-155 K. A portion of the spectrum from 1.9 to 3.9 microns wavelength is shown in the form of imaginary coefficient of refraction ( = linear absorption x wavelength / 4 pi). The data above 3x10(exp -5) are obtained from, except for the absorption line at 3.32 micrometers, which is extrapolated in a way that is consistent with laboratory frost measurements, but the peak level is still highly uncertain. This new imagary coefficient, combined with the real coefficient, can be immediately applied to the models for hemispherical albedo, resulting in markedly different results from those in that study. The results for an infinite optical depth layer and solar incidence of 60 degrees are plotted for a range of mean particle radii from 0.03 to 3 mm.

Hansen, Gary B.; Martin, Terry Z.

1993-01-01

366

LASER APPLICATIONS AND OTHER TOPICS IN QUANTUM ELECTRONICS: Application of deformable mirrors in industrial CO2 lasers. I. A mirror with a controllable curvature of the reflecting surface  

NASA Astrophysics Data System (ADS)

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.

Vyskubenko, O. B.; Kapustin, P. I.; Kolokolov, I. S.; Masychev, V. I.; Safronov, A. G.

2003-06-01

367

Haitian reflections.  

PubMed

Natural disasters and acts of terrorism demonstrate a similar critical need for national preparedness. As one of a team of volunteers with a local South African NGO who recently went on a medical mission, I would like to share glimpses of our experience and reflect on the mistakes - and also to state the obvious: that we do not learn from our mistakes. A simple literature search has shown that the same mistakes happen repeatedly. 'Humanitarian disasters occur with frightening regularity, yet international responses remain fragmented, with organizations and responders being forced to "reinvent the wheel" with every new event'. This is the result of an obvious lack of preparedness. PMID:20822625

Docrat, Fathima

2010-08-01

368

Optical reflectance of metallic coatings: Effect of aluminum flake orientation  

Microsoft Academic Search

A set of aluminum-flake pigmented coatings having different flake orientations was prepared using various spraying conditions.\\u000a The flake surface topography and the orientations of individual flakes were determined from images obtained by laser scanning\\u000a confocal microscopy. Reflectance measurements were carried out to quantify the optical properties of the coatings. Both a\\u000a Gaussian distribution (used to represent the measured flake orientation

Li-Piin Sung; Maria E. Nadal; Mary E. McKnight; Egon Marx; Brent Laurenti

2002-01-01

369

Resolving radial composition gradients in polarized confocal raman spectra of individual 3C-SiC nanowires.  

PubMed

Silicon carbide nanowires are being actively pursued as components for nanoelectromechanical sensors, nanocatalytic elements, and nano-optical circuits able to operate in harsh environment, high temperature, and high power applications. The effect of geometric confinement and polarization anisotropy in confocal Raman spectroscopy has been employed to detect axial and radial composition information in individual nanowires. Polarization anisotropy causes a significant increase in signal from the surface layer (relative to bulk), and combined with the increased surface-to-volume ratio at the nanoscale, it allows for the direct characterization of bulk and surface defects. PMID:17105265

Fréchette, Joëlle; Carraro, Carlo

2006-11-22

370

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

PubMed Central

Fiber-optics confocal microscopy (FCM) is an emerging imaging technology with various applications in basic research and clinical diagnosis. FCM allows for real-time in situ microscopy of tissue at sub-cellular scale. Recently FCM has been investigated for cardiac imaging, in particular, for discrimination of cardiac tissue during pediatric open-heart surgery. FCM relies on fluorescent dyes. The current clinical approach of dye delivery is based on systemic injection, which is associated with high dye consumption, and adverse clinical events. In this study, we investigated approaches for local dye delivery during FCM imaging based on dye carriers attached to the imaging probe. Using three-dimensional confocal microscopy, automated bench tests, and FCM imaging we quantitatively characterized dye release of carriers composed of open-pore foam only and foam loaded with agarose hydrogel. In addition, we compared local dye delivery with a model of systemic dye delivery in the isolated perfused rodent heart. We measured the signal-to-noise ratio (SNR) of images acquired in various regions of the heart. Our evaluations showed that foam-agarose dye carriers exhibited a prolonged dye release vs. foam-only carriers. Foam-agarose dye carriers allowed reliable imaging of 5–9 lines, which is comparable to 4–8 min of continuous dye release. Our study in the living heart revealed that the SNR of FCM images using local and systemic dye delivery is not different. However, we observed differences in the imaged tissue microstructure with the two approaches. Structural features characteristic of microvasculature were solely observed for systemic dye delivery. Our findings suggest that local dye delivery approach for FCM imaging constitutes an important alternative to systemic dye delivery. We suggest that the approach for local dye delivery will facilitate clinical translation of FCM, for instance, for FCM imaging during pediatric heart surgery. PMID:25309455

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

2014-01-01

371

Lateral diffusion measurement at high spatial resolution by scanning microphotolysis in a confocal microscope.  

PubMed Central

Fluorescence photobleaching methods have been widely used to study diffusion processes in the plasma membrane of single living cells and other membrane systems. Here we describe the application of a new photobleaching technique, scanning microphotolysis. Employing a recently developed extension module to a commercial confocal microscope, an intensive laser beam was switched on and off during scanning according to a user definable image mask. Thereby the location, geometry, and number of photolysed spots could be chosen arbitrarily, their size ranging from tens of micrometers down to the diffraction limit. Therewith we bleached circular areas on the surface of single living 3T3 cells labeled with the fluorescent lipid analog NBD-HPC. Subsequently, the fluorescence recovery process was observed using the attenuated laser beam for excitation. This yielded image stacks representing snapshots of the spatial distribution of fluorescent molecules. From these we computed the radial distribution functions of the photobleached dye molecules. The variance of these distributions is linearly related to the diffusion constant, time, and the mobile fraction of the diffusing species. Furthermore, we compared directly the theoretically expected and measured distribution functions, and could thus determine the diffusion coefficient from each single image. The results of these two new evaluation methods (D = 0.3 +/- 0.1 micron 2/s) agreed well with the outcome of conventional fluorescence recovery measurements. We show that by scanning microphotolysis information on dynamical processes such as diffusion of lipids or proteins can be acquired at the superior spatial resolution of a confocal laser scanning microscope. Images FIGURE 2 Fig.2b PMID:7811951

Kubitscheck, U; Wedekind, P; Peters, R

1994-01-01

372

Laser confocal feedback tomography and nano-step height measurement  

PubMed Central

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

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

2013-01-01

373

Endocrine and metabolic disease: Confocal microscopy as a diagnostic aid  

PubMed Central

Diabetes is a systemic disease associated with many complications. These can be prevented and managed effectively if detected promptly. Confocal microscopy (CFM) is a diagnostic tool which has the potential to help in early detection of disease and timely management. CFM has the potential to serve as an excellent noninvasive modality for in vivo imaging and morphological analysis, which can aid us in assessing and monitoring various infectious and pathological diseases at the cellular level. Besides ophthalmological indications, CFM has shown good sensitivity and specificity for identifying those at risk of neuropathy and foot ulceration, monitoring evolution and therapeutic response in a wide range of neuropathies apart from diabetic neuropathy. Through this communication, we aim to sensitize the endocrinologists towards cerebral cavernous malformation as a biomarker to evaluate potential outcomes and therapies in human diabetic neuropathy.

Bhutani, Jaikrit; Chakinala, Raja Chandra; Bhutani, Sukriti; Sachdeva, Shruti

2015-01-01

374

Spatial resolution of confocal XRF technique using capillary optics  

PubMed Central

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

2013-01-01

375

Quantification of transendothelial migration using three-dimensional confocal microscopy.  

PubMed

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

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

2011-01-01

376

Corneal confocal microscopy is efficient, well-tolerated, and reproducible.  

PubMed

In order to develop an efficient, reproducible, and well-tolerated protocol for assessing corneal innervation, 11 normal subjects underwent corneal confocal microscopy (CCM) using a Heidelberg Retinal Tomography III microscope. Five standardized locations were sampled in the left eye and one centrally in the right. The protocol was repeated 1-4?weeks later. A blinded technician measured nerve fiber length (NFL) and tortuosity coefficient (TC). The relationship between image location and NFL and TC was assessed using one-way analysis of variance, and reproducibility determined using relative intertrial variability and intraclass correlation coefficients. NFL reproducibility was maximized by averaging four or more images from the left eye, or one central image from both eyes. TC was less reproducible. CCM is a rapid, well-tolerated, and reproducible method for assessing corneal innervation. PMID:23521645

Smith, Albert Gordon; Kim, Gene; Porzio, Michael; Allen, Blaine; Koach, Margaret; Mifflin, Mark; Digre, Kathleen; Keung, Bonnie M; Singleton, John Robinson

2013-03-01

377

Two-photon confocal microscopy in wound healing  

NASA Astrophysics Data System (ADS)

Advances in histopathology and immunohistochemistry have allowed for precise microanatomic detail of tissues. Two Photon Confocal Microscopy (TPCM) is a new technology useful in non-destructive analysis of tissue. Laser light excites the natural florophores, NAD(P)H and NADP+ and the scattering patterns of the emitted light are analyzed to reconstruct microanatomic features. Guinea pig skin was studied using TPCM and skin preparation methods including chemical depilation and tape striping. Results of TPCM were compared with conventional hematoxylin and eosin microscopy. Two-dimensional images were rendered from the three dimensional reconstructions. Images of deeper layers including basal cells and the dermo-epidermal junction improved after removing the stratum corneum with chemical depilation or tape stripping. TCPM allows good resolution of corneocytes, basal cells and collagen fibers and shows promise as a non-destructive method to study wound healing.

Navarro, Fernando A.; So, Peter T. C.; Driessen, Antoine; Kropf, Nina; Park, Christine S.; Huertas, Juan C.; Lee, Hoon B.; Orgill, Dennis P.

2001-04-01

378

Clinical results with acridine orange using a novel confocal laparoscope  

NASA Astrophysics Data System (ADS)

We previously reported on the development of a multi-spectral confocal laparoscope for clinical imaging. In this paper we present current results using the system to image ovaries with a new laparoscope design using the contrast agent acridine orange. This new laparoscope integrates computer controlled systems for focus, depth scans, and localized contrast agent delivery. Precise axial position control is accomplished with tiny stepper motors integrated inside the laparoscope handle. Ergonomic handle controls allow for data acquisition, deliver of contrast agents, and adjustment of imaging depth during procedures by the surgeon. We have approval to use acridine orange in our clinical trials to image ovaries in vivo during oophorectomies. We present in vivo results using both acridine orange and fluorescein as the topically administered contrast agent.

Tanbakuchi, Anthony A.; Rouse, Andrew R.; Hatch, Kenneth D.; Gmitro, Arthur F.

2009-02-01

379

Volume rendering the neural network in an insect brain in confocal microscopic volume images  

Microsoft Academic Search

Confocal microscopy is an important tool in neural science research. Using proper staining technique, the neural network can be visualized in the confocal microscopic images. It is a great help if neural scientists can directly visualize the 3D neural network. Volume render the neuron fibers is not easy since other objects such as neuropils are also polluted in the staining

Fu-Chi A. Ku; Yu-Tai Ching

2003-01-01

380

Three-dimensional visualization of confocal images of wood pulp fibres  

Microsoft Academic Search

The ability of the confocal laser scanning microscope (CLSM) to generate two-dimensional images within thick fluorescent specimens has added a new dimension to the study of biological systems, a practical third dimension [1]. Previously, microscopic investigation was largely limited to thin sections of specimens, and determining the three-dimensional structure was left to the imagination of the investigator [2]. Now confocal

A. G. Robertson; H. F. Jang; R. S. Seth

1992-01-01

381

Confocal Raman microscopy as a diagnostic tool for investigation of living neuroblastoma tumour cells  

Microsoft Academic Search

The investigation of living cells at physiological conditions requires very sensitive, sophisticated and non-invasive methods. In this study, Raman spectroscopy, a chemically and structurally sensitive measuring technique is combined with high-resolution confocal microscopy to investigate different biomolecules inside of cells. In Raman spectral imaging mode, a complete Raman spectrum is recorded at every confocal image point, giving insight into the

Claudia Scalfi-Happ; Andrea Jauss; Wolfram Ibach; Olaf Hollricher; Simone Fulda; Carmen Hauser; Rudolf Steiner; Angelika Rück

2007-01-01

382

Optical sectioning using a digital Fresnel incoherent-holography-based confocal  

E-print Network

Optical sectioning using a digital Fresnel incoherent-holography-based confocal imaging system ROY We propose a new type of confocal microscope using Fresnel incoherent correlation holography (FINCH of America OCIS codes: (090.0090) Holography; (090.1995) Digital holography; (110.6880) Three

Rosen, Joseph

383

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

E-print Network

Fiber-based confocal microscope for cryogenic spectroscopy Alexander Högele,1,a Stefan Seidl,1 and performance of a fiber-based confocal microscope for cryogenic operation. The microscope combines positioning sweeps, as well as magnetic field variation between -9 and 9 T. As a demonstration of the microscope

Ludwig-Maximilians-Universität, München

384

Fully automated intensity compensation for confocal microscopic images.  

PubMed

One well-recognized problem in three-dimensional (3D) confocal microscopic images is that the intensities in deeper slices are generally weaker than those in shallower slices. The loss of intensity with depth hampers both qualitative observation and quantitative measurement of specimens. Two major types of methods exist to compensate for this intensity loss: the first is based on the geometrical optics inside the specimen, and the second applies an empirical parametric intensity decay function (IDF) of depth. A common feature shared by both methods is that they are parameter-dependent. However, for the optics-based method there are as yet no fully automated parameter-setting approaches; and for the IDF method the traditional profile-fitting approach cannot provide proper parameters if the presumed IDF model does not match the experimental intensity-depth profile of the 3D image. In this paper, we propose a novel maximum-entropy (ME) approach to fully automated parameter-setting. In principle the ME approach is suitable for any compensation method as long as it is parameter-dependent. The basic assumption is that without intensity loss an ideal 3D image should be generally homogeneous with respect to depth and this axial homogeneity can be represented by the entropy of a normalized intensity-depth profile. Experiments on real confocal images showed that such a profile was consistent with visual evaluation of axial intensity homogeneity and that the ME approach could provide proper parameters for both compensation methods mentioned above. Moreover, for the IDF method, experiments on both real and simulated data showed that the ME approach could provide more precise parameters than with traditional profile-fitting. The Appendix provides a proof that under certain conditions the global maximization of the profile-entropy is guaranteed. PMID:16269059

Wu, H-X; Ji, L

2005-10-01

385

Visible and Mid-Infrared Supercontinuum Generation and Their Respective Application to Three-Dimensional Imaging and Stand-off Reflection Spectroscopy  

NASA Astrophysics Data System (ADS)

The thesis describes broadband supercontinuum (SC) generation in optical fibers for both the visible and mid-infrared regions of the spectrum, and their respective application to 3D imaging and stand-off reflection spectroscopy. Both SC sources leverage mature telecom technology, and are based on a common all-fiber integrated platform comprising a ˜1.55 mum distributed feedback seed laser diode amplified to high peak powers in two stages of cladding pumped Erbium or Erbium-Ytterbium fiber amplifiers. A visible SC extending from 0.45--1.20 mum with 0.74 W of time-averaged power is demonstrated using a two step process. The output of the Er-Yb power amplifier is frequency doubled to ˜0.78 mum using a periodically poled lithium niobate crystal, followed by non-linear spectral broadening in 2m of high nonlinearity photonic crystal fiber. Numerical simulations based on solving the generalized non-linear Schrodinger equation are also presented to verify the underlying SC generation mechanisms and predict further improvements. The above SC source is used in a Fourier domain line scan interferometer to measure the height and identify shape defects of ˜300 mum high solder balls in a ball grid array. The 3D imaging system has an axial resolution of ˜125 nm, transverse resolution of ˜15 mum, and an angular measurement range between 20 to 60 degrees depending on the sample surface roughness. The mid-infrared SC source is generated by pumping a 9m long ZrE 4-BaF2-LaF3-AlF3-NaF (ZBLAN) fiber to obtain a spectrum spanning 0.8--4.3 mum with 3.9 W time-averaged power. The output power is linearly scalable with pump power, but requires optimization of the critical splices and thermal management of the gain fiber and pump diodes to ensure stable high power operation. Finally, an application of the mid-IR SC is demonstrated by measuring the diffuse reflection spectra of solid samples at a stand-off distance of 5 m and 100 ms integration time. The samples can be distinguished using a correlation algorithm based on distinct spectral features in the reflection spectrum. Signal to noise ratio calculations show that the distance is limited by space constraints in our lab and can be extended to ˜150 m.

Kumar, Malay

386

Three-dimensional assessment of bone turnover using computed microtomography and laser-scanning confocal microscopy  

NASA Astrophysics Data System (ADS)

Objective: Metabolic activity in trabecular bone is an important indicator in the therapy of bone diseases like osteoporosis. It is reflected by the amount of osteoid (young, not yet mineralized bone) and young calcified tissue (YCT). Our aim was to replace standard 2D histomorphometry with a 3D approach for osteoid and YCT measurement. Measurement Methods: Excised lumbar vertebrae of 5 ovariectomized (OVX) and 5 control rats were 3D-scanned with computed micro-tomography ((mu) CT, isotropic spatial resolution 20 micrometer3) and laser scanning confocal microscopy (LSCM, 20X magnification, 1X1X2 micrometer3 spatial resolution). (mu) CT shows trabecular bone structure; LSCM shows osteoid and YCT by fluorescent light. Image Processing Methods: The fraction of bone to tissue volume (BV/TV) and the number of trabeculae (Tb.N) were calculated from globally thresholded (mu) CT images. LSCM images were enhanced using top-hat transform, globally thresholded and morphologically closed. Separate regions were labeled by volume growing. We measured feature volume to background volume ratio and number of features per unit volume. Results and Conclusions: In the specimens obtained from the OVX rats, a significant increase in the volume fractions of osteoid and YCT could be seen. The (mu) CT-LSCM approach presents a significant improvement over time-consuming, standard histomorphometry. The image processing for both modalities could be achieved automatically.

Prevrhal, Sven; Jiang, Yebin; Zhao, Jenny; Genant, Harry K.

2000-06-01

387

Calcification at the interface between titanium implants and bone: observation with confocal laser scanning microscopy.  

PubMed

It has not been previously possible to observe bone formation in undecalcified sections with titanium implants at high magnification because of the difficulty in sectioning bone together with implants. A method for examining the bone-implant interface in undecalcified sections is described in which implants are left in situ and confocal laser scanning microscopy (CLSM) is used to examine both the implant surface and adjacent bone. Pulsing of animals at different times with the fluorescent dyes calcein and alizarin red permitted assessment of temporal patterns of bone formation by CLSM. Reflectivity of the polished implant surface permitted accurate assessment of the position of the implant relative to labeled bone. The analysis showed that bone first formed as thin processes towards and across the implant surface, followed by further bone formation behind these processes. The interface between calcified bone tissue and the implant surface was characterized by a 10-microm space. The CLSM technique enabled detailed observations of new bone formation at the titanium implant interface. PMID:17069165

Nishikawa, Tetsunari; Masuno, Kazuya; Mori, Masahiko; Tajime, Yasuhiro; Kakudo, Kenji; Tanaka, Akio

2006-01-01

388

Polarimetric Control of Reflective Metasurfaces  

E-print Network

This letter addresses the synthesis of reflective cells approaching a given desired Floquet's scattering matrix. This work is motivated by the need to obtain much finer control of reflective metasurfaces by controlling not only their co-polarized reflection but also their cross-coupling behavior. The demonstrated capability will enable more powerful design approaches -involving all field components in phase and magnitude- and consequently better performance in applications involving reflective metasurfaces. We first expose some fundamental theoretical constraints on the cell scattering parameters. Then, a successful procedure for controlling all four scattering parameters by applying parallelogram and trapezoid transformations to square patches is presented, considering both normal and oblique incidence.

Artiga, Xavier; Legay, Hervé; Perruisseau-Carrier, Julien

2012-01-01

389

Acceptance testing of the Lasentec focused beam reflectance measurement (FBRM) monitor for slurry transfer applications at Hanford and Oak Ridge  

NASA Astrophysics Data System (ADS)

The Lasentec M600F FBRM particle size and population monitor (Lasentec, Redmond, WA) was selected for deployment on radioactive slurry transfer systems at Oak Ridge National Laboratory and Hanford after extensive testing with `physical simulants.' These tests indicated that the monitor is able to measure the change in particle size distribution of concentrated (up to 35 vol.%) slurries at flow rates greater than 2 m/sec. As well, the monitor provided relatively stable mean particle size values when air bubbles were introduced to the slurry pipe test loop and when the color of the slurry was altered. Slurry samples taken during each test were analyzed with a laboratory particle size monitor. For kaolin slurry samples (length-cubed weighted mean of around 55 micrometers ), the Lasentec M600F FBRM in-line monitor measured length-cubed weighted mean particle sizes within 25% of those measured by a laboratory Lasentec M500LF monitor. This difference is thought primarily to be the result of sample handling issues. Regardless, this accuracy is acceptable for radioactive slurry transfer applications. Once deployed, the in-line Lasentec monitor is expected to yield significant cost savings at Hanford and Oak Ridge through the possible reduction in risk of pipeline blockage. In addition, fewer samples of radioactive slurries will need to be measured in the laboratory, further reducing costs and increasing safety.

Daymo, Eric A.; Hylton, Tom D.; May, Thomas H.

1999-01-01

390

Reflected Glory  

NASA Astrophysics Data System (ADS)

The nebula Messier 78 takes centre stage in this image taken with the Wide Field Imager on the MPG/ESO 2.2-metre telescope at the La Silla Observatory in Chile, while the stars powering the bright display take a backseat. The brilliant starlight ricochets off dust particles in the nebula, illuminating it with scattered blue light. Igor Chekalin was the overall winner of ESO's Hidden Treasures 2010 astrophotography competition with his image of this stunning object. Messier 78 is a fine example of a reflection nebula. The ultraviolet radiation from the stars that illuminate it is not intense enough to ionise the gas to make it glow - its dust particles simply reflect the starlight that falls on them. Despite this, Messier 78 can easily be observed with a small telescope, being one of the brightest reflection nebulae in the sky. It lies about 1350 light-years away in the constellation of Orion (The Hunter) and can be found northeast of the easternmost star of Orion's belt. This new image of Messier 78 from the MPG/ESO 2.2-metre telescope at the La Silla Observatory is based on data selected by Igor Chekalin in his winning entry to the Hidden Treasures competition [1]. The pale blue tint seen in the nebula in this picture is an accurate representation of its dominant colour. Blue hues are commonly seen in reflection nebulae because of the way the starlight is scattered by the tiny dust particles that they contain: the shorter wavelength of blue light is scattered more efficiently than the longer wavelength red light. This image contains many other striking features apart from the glowing nebula. A thick band of obscuring dust stretches across the image from the upper left to the lower right, blocking the light from background stars. In the bottom right corner, many curious pink structures are also visible, which are created by jets of material being ejected from stars that have recently formed and are still buried deep in dust clouds. Two bright stars, HD 38563A and HD 38563B, are the main powerhouses behind Messier 78. However, the nebula is home to many more stars, including a collection of about 45 low mass, young stars (less than 10 million years old) in which the cores are still too cool for hydrogen fusion to start, known as T Tauri stars. Studying T Tauri stars is important for understanding the early stages of star formation and how planetary systems are created. Remarkably, this complex of nebulae has also changed significantly in the last ten years. In February 2004 the experienced amateur observer Jay McNeil took an image of this region with a 75 mm telescope and was surprised to see a bright nebula - the prominent fan shaped feature near the bottom of this picture - where nothing was seen on most earlier images. This object is now known as McNeil's Nebula and it appears to be a highly variable reflection nebula around a young star. This colour picture was created from many monochrome exposures taken through blue, yellow/green and red filters, supplemented by exposures through an H-alpha filter that shows light from glowing hydrogen gas. The total exposure times were 9, 9, 17.5 and 15.5 minutes per filter, respectively. Notes [1] Igor Chekalin from Russia uncovered the raw data for this image of Messier 78 in ESO's archives in the competition Hidden Treasures (eso1102). He processed the raw data with great skill, claiming first prize in the contest for his final image (Flickr link). ESO's team of in-house image processing experts then independently processed the raw data at full resolution to produce the image shown here. More information ESO, the European Southern Observatory, is the foremost intergovernmental astronomy organisation in Europe and the world's most productive astronomical observatory. It is supported by 15 countries: Austria, Belgium, Brazil, the Czech Republic, Denmark, France, Finland, Germany, Italy, the Netherlands, Portugal, Spain, Sweden, Switzerland and the United Kingdom. ESO carries out an ambitious programme focused on the design, construction and operation of powerful ground-based obser

2011-02-01

391

Can the caged bird sing? Reflections on the application of qualitative research methods to case study design in homeopathic medicine  

PubMed Central

Background Two main pathways exist for the development of knowledge in clinical homeopathy. These comprise clinical trials conducted primarily by university-based researchers and cases reports and homeopathic "provings" compiled by engaged homeopathic practitioners. In this paper the relative merits of these methods are examined and a middle way proposed. This consists of the "Formal Case Study" (FCS) in which qualitative methods are used to increase the rigour and sophistication with which homeopathic cases are studied. Before going into design issues this paper places the FCS in an historical and academic context and describes the relative merits of the method. Discussion Like any research, the FCS should have a clear focus. This focus can be both "internal", grounded in the discourse of homeopathy and also encompass issues of wider appeal. A selection of possible "internal" and "external" research questions is introduced. Data generation should be from multiple sources to ensure adequate triangulation. This could include the recording and transcription of actual consultations. Analysis is built around existing theory, involves cross-case comparison and the search for deviant cases. The trustworthiness of conclusions is ensured by the application of concepts from qualitative research including triangulation, groundedness, respondent validation and reflexivity. Though homeopathic case studies have been reported in mainstream literature, none has used formal qualitative methods – though some such studies are in progress. Summary This paper introduces the reader to a new strategy for homeopathic research. This strategy, termed the "formal case study", allows for a naturalistic enquiry into the players, processes and outcomes of homeopathic practice. Using ideas from qualitative research, it allows a rigorous approach to types of research question that cannot typically be addressed through clinical trials and numeric outcome studies. The FCS provides an opportunity for the practitioner-researcher to contribute to the evidence-base in homeopathy in a systematic fashion. The FCS can also be used to inform the design of clinical trials through holistic study of the "active ingredients" of the therapeutic process and its clinical outcomes. PMID:15018637

Thompson, Trevor DB

2004-01-01

392

In vivo confocal microscopic characteristics of crystalline keratopathy in patients with monoclonal gammopathy: report of two cases.  

PubMed

In this paper, we report two cases of a 62-year-old patient presented with blurred vision and a 45-year-old male diagnosed with multiple myeloma who was referred from the Department of Oncology. Slit-lamp examination, in vivo confocal microscopy (IVCM), systemic work-up and serum protein electrophoresis were obtained. In both patients, slit-lamp findings revealed bilateral diffuse subepithelial and anterior stromal crystals and IVCM showed highly reflective deposits in the corneal epithelium and stroma. The first patient was eventually diagnosed with monoclonal gammopathy of undetermined significance following bone marrow biopsy and systemic evaluation. Unusual corneal deposits may constitute the first sign of monoclonal gammopathies. IVCM may be helpful in showing the crystalline nature of the corneal deposits and guiding the clinician to the diagnosis of gammopathies. Both ophthalmologists and oncologists should be aware that corneal deposits may herald a life-threatening hematologic disease. PMID:25370397

Kocabeyoglu, Sibel; Mocan, Mehmet C; Haznedaroglu, Ibrahim C; Uner, Aysegul; Uzunosmanoglu, Enes; Irkec, Murat

2014-09-01

393

Quantitative read-out of Al2O3:C,Mg-based fluorescent nuclear track detectors using a commercial confocal microscope  

E-print Network

Fluorescent nuclear track detectors (FNTD) show great potential for applications in ion-beam therapy research, such as dosimetry, advanced beam characterization, in-vivo use or as radiobiological assay. A essential feature of FNTDs is their ability to assess the energy loss of single ions yielding for example LET estimations. This article describes the basic characterisations of FNTDs and our read-out system (a Zeiss LSM710 confocal laser scanning microscope) to enable quantative measurements of energy loss.

Greilich, Steffen; Niklas, Martin; Lauer, Florian; Bestvater, Felix; Jäkel, Oliver

2014-01-01

394

High-resolution imaging using a novel atomic force microscope and confocal laser scanning microscope hybrid instrument: essential sample preparation aspects  

Microsoft Academic Search

The recent data explosion in global gene expression profiling and proteomics has resulted in a need to determine the mechanistic\\u000a role of biomarker signatures in pathogenicity. Consequently, elaborate technologies are required to assess increasingly smaller\\u000a sub-cellular compartments and constituents. We describe the development, evaluation and application of an efficient sample\\u000a preparation methodology to facilitate coupled atomic force microscopy and confocal

Shareen H. Doak; Dale Rogers; Beverley Jones; Lewis Francis; R. Steven Conlan; Chris Wright

2008-01-01

395

Reflection- quantifying a rare good  

E-print Network

Abstract. Based on a literature review, reflections in written text are rare. The reported proportions of reflection are based on different baselines, making comparisons difficult. In contrast, this research reports on the proportion of occurrences of elements of reflection based on sentence level. This metric allows to compare proportions of elements of reflection. Previous studies are based on courses tailored to foster reflection. The reported proportions represent more the success of a specific instruction than informing about proportions of reflections occurring in student writings in general. This study is based on a large sample of course forum posts of a virtual learning environment. In total 1000 sentences were randomly selected and manually classified according to six elements of reflection. Five raters rated each sentence. Agreement was calculated based on a majority vote. The proportions of elements of reflection are reported and its potential application for course analytics demonstrated. The results indicate that reflections in text are indeed rare, and that there are differences within elements of reflection.

Thomas Daniel Ullmann; Fridolin Wild; Peter Scott

396

Application of the NEES T-Rex Vibrator for 3-component Crustal Reflection/Refraction Profiling: 2004 Test in the Basin and Range  

NASA Astrophysics Data System (ADS)

In September 2004, Stanford University and UT Austin collected crustal reflection/refraction data with the Network for Earthquake Engineering Simulation (NEES) tri-axial (T-Rex) vibrator in two separate surveys: (1) a 40 km crustal-scale profile in the Black Rock Desert and Black Rock Range, NV; and (2) a 16 km `high-resolution' basin imaging profile in Surprise Valley, CA. Both experiments were completed in the northwestern Basin and Range transition zone as part of a larger, 300 km wide-angle refraction line, recorded by an IRIS-PASSCAL transportable array. Our broad goals were to test the feasibility of the T-Rex in crustal-scale applications with existing IRIS-PASSCAL equipment, and to augment our refraction data with structural information. T-Rex, acquired by NEES-UT Austin in 2002, is a 64,000 lb buggy-mounted vibrator with a tri-axial mass, producing P, SV, and SH waves. In order to balance desired upper-crustal resolution with an attempt to record mid-crustal reflectivity and shear-wave data during the crustal-scale profiling, T-Rex swept at 300 m intervals for 5 minutes (1 min. P, 2 min. SV, 2 min. SH), and at 3 km intervals for 50 minutes (10 min. P, 20 min. SV, 20 min. SH). This source configuration afforded coverage of a relatively wide aperture in a modest amount of field time, while stacked sweeps recorded at 3 km intervals provided greater source effort than individual vibration points for the 1983 COCORP 40ON Nevada deep reflection profile which recorded strong Moho reflections. Crustal data were continuously recorded in four-hour windows at 125 sps on a combination of vertical (RefTek Texan) and 3-component (RefTek RT130) instruments forming a 40 km array spaced at 100 m, embedded within the larger wide-angle profile. The `hi-res' survey (250 sps, 40 m receiver spacing, 10 m source spacing) imaged the active Surprise Valley basin to constrain basin depth, fault geometry, and basin-fill P- and S-wave velocities. Our source effort (single 1 min. sweeps) is comparable with prior successful efforts to image upper-crustal basement structure (e.g., Virginia Tech's 1981 Atlantic Coastal Plain survey). Despite attenuation and poor coupling in the unconsolidated basin fill (Vp ~ 1.8 km/s) of Surprise Valley and the Black Rock Desert, coherent refracted energy on raw, single-sweep gathers is visible to 9 km offset, with reflections visible to ~ 3 sec (twtt). Our data indicate the NEES T-Rex vibrator is a viable source for upper crustal P- and S-wave surveys, and may produce useful mid-crustal data under favorable conditions.

Lerch, D. W.; Klemperer, S. L.; Stokoe, K. H.; Menq, F.

2005-12-01

397

Three-dimensional confocal microscopy of the human cornea in vivo.  

PubMed

This paper reviews the literature from 1990 to 2000 and evaluates the seminal investigations performed with the confocal microscope on the in vivo human cornea. Our pedagogical technique is to illustrate both the advantages and the problems associated with occular confocal microscopy by way of annotated examples. Confocal microscopy offers improved resolution and has resulted in new discoveries of corneal pathology at the cellular level. The ability to provide high-resolution, real-time images of the full thickness of the cornea gives the clinician and the researcher an important new tool for the investigation of the cornea. PMID:11340402

Masters, B R; Böhnke, M

2001-01-01

398

Confocal mapping of cortical inputs onto identified pyramidal neurons.  

PubMed

Using a confocal microscopy protocol, we carried out a microcircuitry investigation of cortical connections in monkey temporal cortex. Inputs were labeled by BDA injections in posterior area TE, and potential postsynaptic pyramidal neuron targets were labeled with EGFP, by injection of retrogradely transported adenovirus. We scored the number and distribution of putative contacts onto dendritic compartments of neurons in different layers. Initial results show that about 50 percent of apical dendrites of layer (L.) 6 neurons receive contacts, as they ascend through L.4 (n=1 brain), but only 30-35 percent of those from L.5 neurons (n=2). Basal dendrites of L.3 neurons also receive few contacts in L.4. This supports the role of layer 4 as an interlaminar relay in association cortex. In addition, our results indicate spatial heterogeneity in the occurrence and number of contacts, possibly due to subtype specificity in target preference. The maximum number of contacts, for a L.2 neuron projecting from anterior to posterior TE, was 29. This approach seems a useful alternative or complement to electron microscopic analyses of long distance connectivity. PMID:18508665

Ichinohe, Noritaka; Hyde, James; Matsushita, Atsuko; Ohta, Kazumi; Rockland, Kathleen S

2008-01-01

399

Analyzing Craniofacial Morphogenesis in Zebrafish Using 4D Confocal Microscopy  

PubMed Central

Time-lapse imaging is a technique that allows for the direct observation of the process of morphogenesis, or the generation of shape. Due to their optical clarity and amenability to genetic manipulation, the zebrafish embryo has become a popular model organism with which to perform time-lapse analysis of morphogenesis in living embryos. Confocal imaging of a live zebrafish embryo requires that a tissue of interest is persistently labeled with a fluorescent marker, such as a transgene or injected dye. The process demands that the embryo is anesthetized and held in place in such a way that healthy development proceeds normally. Parameters for imaging must be set to account for three-dimensional growth and to balance the demands of resolving individual cells while getting quick snapshots of development. Our results demonstrate the ability to perform long-term in vivo imaging of fluorescence-labeled zebrafish embryos and to detect varied tissue behaviors in the cranial neural crest that cause craniofacial abnormalities. Developmental delays caused by anesthesia and mounting are minimal, and embryos are unharmed by the process. Time-lapse imaged embryos can be returned to liquid medium and subsequently imaged or fixed at later points in development. With an increasing abundance of transgenic zebrafish lines and well-characterized fate mapping and transplantation techniques, imaging any desired tissue is possible. As such, time-lapse in vivo imaging combines powerfully with zebrafish genetic methods, including analyses of mutant and microinjected embryos. PMID:24514435

McGurk, Patrick D.; Lovely, C. Ben; Eberhart, Johann K.

2014-01-01

400

Imaging liver biology in vivo using conventional confocal microscopy.  

PubMed

Imaging of live animals using intravital microscopy (IVM) has provided a substantial advance in our understanding of cell biology. Here we describe how to adapt a conventional, relatively low-cost laser-scanning microscope to operate as a versatile imaging station. We present the surgical procedures needed to perform liver confocal IVM in mice, thereby allowing one to image different cells in their native environment, including hepatocytes, endothelial cells and leukocytes, as well as to analyze their morphology and function under physiological or pathological conditions. In addition, we propose a plethora of working doses of antibodies and probes to stain multiple cells and molecules simultaneously in vivo. Considering the central role of the liver in metabolism and immunity and the growing interest in the relationship between immune and parenchymal cells, this protocol, in which 20 min of preparation yields up to 4 h of imaging, provides useful insights for various research fields. In addition, the protocol can be easily adapted to investigate adipose tissue, mesentery, intestines, spleen and virtually any abdominal organ. PMID:25569332

Marques, Pedro E; Antunes, Maísa M; David, Bruna A; Pereira, Rafaela V; Teixeira, Mauro M; Menezes, Gustavo B

2015-02-01

401

Confocal microendoscope for use in a clinical setting  

NASA Astrophysics Data System (ADS)

A mobile confocal microendoscope for use in a clinical setting has been developed. This system employs an endoscope consisting of a custom designed objective lens with a fiber optic imaging bundle to collect in-vivo images of patients. Some highlights and features of this mobile system include frame rates of up to 30 frames per second, an automated focus mechanism, automated dye delivery, clinician control, and the ability to be used in an area where there is a single 110V outlet. All optics are self-contained and the entire enclosure and catheter can be moved between surgical suites, sterilized and brought online in under 15 minutes. At this time, all data have been collected with a 488 nm laser, but the system is able to have a second laser line added to provide additional imaging capability. Preliminary in vivo results of images from the ovaries using topical fluorescein as a contrast agent are shown. Future plans for the system include use of acridine orange (AO) or SYTO-16 as a nucleic acid stain.

Udovich, Joshua A.; Rouse, Andrew R.; Tanbakuchi, Anthony; Brewer, Molly A.; Sampliner, Richard; Gmitro, Arthur F.

2007-02-01

402

Managing multiple image stacks from confocal laser scanning microscopy  

NASA Astrophysics Data System (ADS)

A major goal in neuroanatomy is to obtain precise information about the functional organization of neuronal assemblies and their interconnections. Therefore, the analysis of histological sections frequently requires high resolution images in combination with an overview about the structure. To overcome this conflict we have previously introduced a software for the automatic acquisition of multiple image stacks (3D-MISA) in confocal laser scanning microscopy. Here, we describe a Windows NT based software for fast and easy navigation through the multiple images stacks (MIS-browser), the visualization of individual channels and layers and the selection of user defined subregions. In addition, the MIS browser provides useful tools for the visualization and evaluation of the datavolume, as for instance brightness and contrast corrections of individual layers and channels. Moreover, it includes a maximum intensity projection, panning and zoom in/out functions within selected channels or focal planes (x/y) and tracking along the z-axis. The import module accepts any tiff-format and reconstructs the original image arrangement after the user has defined the sequence of images in x/y and z and the number of channels. The implemented export module allows storage of user defined subregions (new single image stacks) for further 3D-reconstruction and evaluation.

Zerbe, Joerg; Goetze, Christian H.; Zuschratter, Werner

1999-05-01

403

On the solution of Stokes' equations between confocal ellipses  

NASA Astrophysics Data System (ADS)

The analytical solution of Stokes' equations between two concentric, confocal ellipses is derived here. This bounded flow, similar in certain respects to the journal bearing flow, was imagined in order to investigate two-dimensional mixing and Lagrangian chaos in a bounded flow with two symmetry axis. The derived streamfunction is in the form of a Fourier cosine series and, when the eccentricity ratio of the inner ellipse is not very low, the solution converges very rapidly. When the ellipses turn in opposite directions, there are cases where two saddle points are connected by two different streamlines, a necessary and sufficient condition for structural instability according to Peixoto's theorem. This flow geometry could be particularly effective for mixing of viscous fluids since the number of low period hyperbolic and elliptical points during time periodic boundary motion is greater than for the eccentric rotating cylinder system. The Poincaré sections obtained with a discontinuous velocity protocol suggest that the size of regions of poor mixing can be reduced by increasing the inner ellipse motion per period. For this geometry, the Poincaré sections indicate that counter-rotation yields a more chaotic long term behavior than co-rotation.

Saatdjian, Estéban; Midoux, Noël; André, Jean Claude

1994-12-01

404

Multiphoton, confocal, and lifetime microscopy for molecular imaging in cartilage  

NASA Astrophysics Data System (ADS)

It has recently been shown that mutations in Filamin A and B genes produce a large spectrum of skeletal disorders in developing fetuses. However, high-resolution optical microscopy in cartilage growth plate using fluorescent antibody assays, which should elucidate molecular aspects of these disorders, is extremely difficult due to the high level of autofluoresce in this tissue. We apply multiphoton, confocal, lifetime and spectral microscopy to (i) image and characterize autofluorophores in chondrocytes and subtract their contributions to obtain a corrected antibody-marker fluorescence signal, and (ii) measure the interaction between Filamin A and B proteins by detecting the fluorescence resonance energy transfer (FRET) between markers of the two proteins. Taking advantage of the different fluorescence spectra of the endogenous and exogenous markers, we can significantly reduce the autofluorescence background. Preliminary results of the FRET experiments suggest no interaction between Filamin A and B proteins. However, developing of new antibodies targeting the carboxy-terminal immunoglobulin-like domain may be necessary to confirm this result.

Wachsmann-Hogiu, Sebastian; Krakow, Deborah; Kirilova, Veneta T.; Cohn, Daniel H.; Bertolotto, Cristina; Acuna, Dora; Fang, Qiyin; Krivorov, Nikola; Farkas, Daniel L.

2005-03-01

405

HEAT REFLECTIVE COATINGS OF ALUMINIUM  

Microsoft Academic Search

Thermal emissivity and solar reflectance are important surface characteristics to obtain energy-savings and increased thermal comfort in buildings. Aluminium products used for building applications are normally coated or anodised for protection and visual appearance. Both surface treatments give very high thermal emissivity levels, typically e = 0.85 - 0.9. High emissivity levels are normally unfavourable for building applications. A coating

Merete Hallenstvet; Jostein Mårdalen; Helene Bolm; Volker Rekowski; Steinar Tanem; John Erik Lein

406

Shallow reflection imaging by PSDM of dense, wide-aperture data: application to the causative fault of the 1980, M6.9, southern Italy earthquake  

NASA Astrophysics Data System (ADS)

Shallow reflection imaging of active faults in unconsolidated deposits is a challenging task. Main factors hindering seismic imaging are the presence of steep-dipping reflectors and strong lateral velocity changes across the fault-zone, which often make standard CDP processing inappropriate. This drawback can be in principle overcome by Prestack Depth Migration (PSDM). However, performance of PSDM strongly relies on the availability of an accurate background velocity model, which is critical to account properly for the seismic wave propagation and ray-path bending in the depth domain. Such a velocity model cannot be obtained by standard seismic reflection acquisition geometries due to the small-aperture of the receiver/shot array and to the difficulty in collecting good-quality near-vertical reflection data in the very near-surface. Consequently, PSDM of shallow reflection data is very rare in the scientific literature. Recent applications of PSDM to very complex crustal structures have revealed that the use of non-conventional, dense wide-aperture acquisition geometries allows to successfully face the problem of the background velocity estimation. In this study, we investigate if the PSDM of dense, wide-aperture data can be an effective strategy for shallow imaging of complex structures, such as fault zone. We target the Irpinia Fault (IF), source of the 1980, M6.9, southern Italy normal-faulting earthquake. A 256 m long, ultrahigh resolution wide-aperture profile has been collected across the 1980 fault scarp in a small intermountain basin in the Southern Apennines range (Pantano di San Gregorio Magno). The source and receiver spacing is 3 m and 1.5 m, respectively, and the source is provided by a Buffalo gun. The survey aims at imaging the first 100 m of subsurface and at providing valuable information on the fault zone architecture below a collocated paleoseismic trench. The presence of unconsolidated deposits above a limestone basin substratum translates into strong velocity heterogeneities. To estimate a reliable smooth background velocity model, we used a first-arrival tomographic technique able to cope with sharp lateral Vp changes. The inversion procedure combines a multi-scale approach with a non-linear optimization scheme. A succession of inversions is run by progressively thickening the velocity grid, and for each inversion run the best fit model is found by a combined global/local search. Several Kirchhoff PSDM runs are performed using different velocity models with progressively smaller wavelength contents, but also characterized by lower resolution depths. For each velocity model we check the performance of PSDM on the basis of CIGs analysis and the related pre-stack depth migrated sections. In our case, a velocity model with 35 m horizontal and 15 m vertical node spacing allows to image the short-wavelength components of the fault zone over the full thickness of the basin fill (up to ~100 m), while maintaining metrical resolution. The PSDM section provides superior imaging results compared to the related post-stack depth migration, where the fault plane and the shallow reflectors are hardly visible due to contamination of migration noise. The PSDM shows a clear fault plane that dips about 50° northeastward. Normal drag affects reflectors in both the fault footwall and hangingwall. In the hangingwall, the increase of tilting of reflectors with depth may indicate repeated coseismic deformation episodes, as also suggested by fault related colluvial packages imaged by seismic tomography.

Castiello, Antonio; Bruno, Pier Paolo; Improta, Luigi

2010-05-01

407

The application of in situ mid-FTIR fibre-optic reflectance spectroscopy and GC-MS analysis to monitor and evaluate painting cleaning  

NASA Astrophysics Data System (ADS)

The development of non-invasive methodologies and portable instrumentation for in situ studies has been subject to great research and development in recent years in the field of conservation science. Despite such interest, very few reported studies employ these versatile techniques in the monitoring of cleaning treatments. This paper describes the application of mid-FTIR fibre-optic reflectance spectroscopy to monitor and evaluate the cleaning treatment of an oil painting using the chelating agent, triammonium citrate, a task undertaken in close collaboration with the painting conservator. Results obtained on site verify the removal of calcium oxalate and an organic component from the surface of the painting, later identified as a terpenic varnish. The subsequent, in laboratory FTIR and GC-MS analysis of the cotton swabs employed during the cleaning treatment acts as an additional non-invasive manner to support the results obtained in situ by mid-FTIR spectroscopy and to better understand the mechanism of the chosen cleaning agent.

Kahrim, Kenza; Daveri, Alessia; Rocchi, Paola; de Cesare, Grazia; Cartechini, Laura; Miliani, Costanza; Brunetti, B. G.; Sgamellotti, A.

2009-12-01

408

Design and Fabrication of a Dielectric Total Internal Reflecting Solar Concentrator and Associated Flux Extractor for Extreme High Temperature (2500K) Applications  

NASA Technical Reports Server (NTRS)

The Analex Corporation, under contract to the NASA Lewis Research Center (LeRC), Cleveland, Ohio, recently evaluated the feasibility of utilizing refractive secondary concentrators for solar heat receivers operating at temperatures up to 2500K. The feasibility study pointed out a number of significant advantages provided by solid single crystal refractive devices over the more conventional hollow reflective compound parabolic concentrators (CPCs). In addition to the advantages of higher concentration ratio and efficiency, the refractive concentrator, when combined with a flux extractor rod, provides for flux tailoring within the heat receiver cavity. This is a highly desirable, almost mandatory, feature for solar thermal propulsion engine designs presently being considered for NASA and Air Force thermal applications. Following the feasibility evaluation, the NASA-LeRC, NASA-Marshall Space Flight Center (MSFC), and Analex Corporation teamed up to design, fabricate, and test a refractive secondary concentrator/flux extractor system for potential use in the NASA-MSFC "Shooting Star" flight experiment. This paper describes the advantages and technical challenges associated with the design methodologies developed and utilized and the material and fabrication limitations encountered.

Soules, Jack A.; Buchele, Donald R.; Castle, Charles H.; Macosko, Robert P.

1997-01-01

409

Seasonal variation in canopy reflectance and its application to determine the water status and water use by citrus trees in the Western Cape, South Africa  

Microsoft Academic Search

This study describes the diurnal and seasonal dynamics of the canopy reflectance, water use and water status of Midknight Valencia citrus trees under semi-arid conditions. Hyperspectral canopy reflectance data was collected on 30 trees at monthly intervals over a period of 16 months in a commercial orchard in South Africa. The mean canopy reflectance in the wavelength range 350–2500nm followed

Sebinasi Dzikiti; Stephan J. Verreynne; Jan Stuckens; Albert Strever; Willem W. Verstraeten; Rony Swennen; Karen I. Theron; Pol Coppin

2011-01-01

410

Keratocyte reflectivity and corneal haze.  

PubMed

Corneal transparency is a remarkable characteristic that is essential for vision. Biophysical models of corneal transparency have entirely focused on the stromal extracellular matrix and disruption of the regular array of collagen fibres as the main reason for corneal haziness. Therefore, disorder of corneal transparency has traditionally been explained by a combination of three main factors: (1) abnormal water content (i.e. swelling or edema); (2) abnormal collagen fibre diameter, spacing, and orientation (i.e. scar tissue or fibrosis); and (3) abnormal accumulation of macromolecules (proteins, glycosaminoglycans, lipids, etc.) as in many corneal dystrophies. Here, clinical and experimental data are provided to support the concept that corneal keratocytes, which are normally invisible and transmit light, may show intense light scattering in injured corneas. Thus, the existence of a fourth group of corneal transparency disorders is proposed that predominantly are associated with abnormal cellular-based reflections from multiple layers of stromal keratocytes. In this group of patients, the light scattering structures (keratocyte nuclei, cell-body, and cell-processes) cannot be discriminated using standard slit-lamp biomicroscopy but requires a confocal microscopic examination. Despite their importance, almost nothing is known about the physical basis for the invisibility and haziness of the keratocytes. A more comprehensive model to understand corneal transparency is needed and should include the interaction of visible light with the physical structure of the keratocyte and its subcellular constituents. PMID:15106935

Møller-Pedersen, Torben

2004-03-01

411

Confocal microscopy studies of colloidal assembly on microfabricated physically templated surfaces  

E-print Network

In this research we consider two different approaches for microfabricating physical templates to be used in template directed colloidal self-assembly experiments. Fabrication of templates, usable with confocal microscopy, forms an essential part...

Sharma, Sumit

2005-02-17

412

SINGLE-CELL PIGMENT IDENTIFICATION IN LIVING PHOTOTROPHIC COMMUNITIES BY CONFOCAL IMAGING SPECTROPHOTOMETRY  

E-print Network

SINGLE-CELL PIGMENT IDENTIFICATION IN LIVING PHOTOTROPHIC COMMUNITIES BY CONFOCAL IMAGING using pure pigments, cyanobacterial and green algae cultures and natural assemblages from hypogean pigments from a single cell in situ into thick samples without isolation and the discrimination

413

RELIABILITY OF CONFOCAL MICROSCOPY SPECTRAL IMAGING SYSTEMS: USE OF MULTISPECTRAL BEADS  

EPA Science Inventory

Background: There is a need for a standardized, impartial calibration, and validation protocol on confocal spectral imaging (CSI) microscope systems. To achieve this goal, it is necessary to have testing tools to provide a reproducible way to evaluate instrument performance. ...

414

WHOLE INSECT AND MAMMALIAN EMBRYO IMAGING WITH CONFOCAL MICROSCOPY: MORPHOLOGY AND APOPTOSIS  

EPA Science Inventory

Background: After fluorochromes are incorporated into cells, tissues, and organisms, confocal microscopy can be used to observe three-dimensional structures. LysoTracker Red (LT) is a paraformaldehyde fixable probe that concentrates into acidic compartments of cells and indicates...

415

MAMMALIAN APOPTOSIS IN WHOLE NEONATAL OVARIES USING CONFOCAL LASER SCANNING MICROSCOPY  

EPA Science Inventory

MAMMALIAN APOPTOSIS IN WHOLE NEONATAL OVARIES USING CONFOCAL LASER SCANNING MICROSCOPY Robert M. Zucker Susan C. Jeffery and Sally D. Perreault Reproductive Toxicology Division, National Health and Environmental Effects Research Laboratory, U.S. Environmental Prot...

416

SEM/EDX and confocal Raman microscopy as complementary tools for the characterization of pharmaceutical tablets.  

PubMed

The drug distribution on the surface of hot-melt extruded, pre-mixed hot-melt extruded and direct compressed tablet formulations was characterized by using scanning electron microscopy, energy dispersive X-ray spectroscopy (EDX) and confocal Raman spectroscopy. Formulations of paracetamol (PMOL) and Compritol(®) (C-888) were extruded using hot-melt extrusion at different processing temperatures and formulation compositions before being compressed into tablets. EDX and confocal Raman spectroscopy were employed to map the drug and excipient distribution, both qualitatively and quantitatively, on the surface of the tablets. The results from EDX and confocal Raman studies confirmed better uniformity and distribution of PMOL in the pre-mixed extruded formulations compared to both hot-melt extruded formulations and those obtained by means of direct compression. The quantification of the drug composition on the surface of the tablets by both EDX and confocal Raman was in good agreement with the theoretically expected values. PMID:24836664

Scoutaris, Nikolaos; Vithani, Kapilkumar; Slipper, Ian; Chowdhry, Babur; Douroumis, Dennis

2014-08-15

417

CONFOCAL LASER SCANNING MICROSCOPY OF APOPTOSIS IN WHOLE MOUSE AND RAT OVARIES  

EPA Science Inventory

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

418

Current State of In Vivo Confocal Microscopy in Management of Microbial Keratitis  

PubMed Central

Purpose The purpose of this study was to review the current literature on in vivo confocal microscopy of the cornea and to discuss the current clinical indications for its use in microbial keratitis. Methods Review of select recent literature on in vivo confocal microscopy and atypical microbial keratitis. Results Delayed diagnosis of Acanthamoeba and fungal keratitis is typical, resulting in significant vision loss. This is partially due to the low sensitivity and time delay of corneal cultures. In the hands of an experienced viewer, the confocal microscope has been found to have a sensitivity of up to 90% in the diagnosis of Acanthamoeba keratitis and close to 80% for fungal keratitis. Conclusion In vivo confocal microscopy is emerging as a tool for rapid diagnoses in severe infectious keratitis with high sensitivity. In addition, it can be used to monitor treatment response, allowing guidance to clinicians for medical or surgical management. PMID:21090995

Kumar, Radhika L.; Cruzat, Andrea; Hamrah, Pedram

2011-01-01

419

Confocal fiber-optic laser approach for exact dioptric power measurement of intraocular lens  

Microsoft Academic Search

We have developed a simple, accurate, objective and quick confocal fiber-optic laser method for exact dioptric power measurement of both positive and negative intraocular lenses providing spatial resolution better than 1 mum under simulated in-situ conditions.

Robert W. Faaland; Do-Hyun Kim; Robert H. James; Don Calogero; Ilko K. Ilev

2008-01-01

420

Scattering features for lung cancer detection in fibered confocal fluorescence microscopy images  

E-print Network

;analysis, fibered confocal fluorescence microscopy imaging, bronchoscopy. 1. Introduction Lung cancer computed tomography [4, 5]. For centrally located lung cancer, bronchoscopy is an essential tool fiberoptic bronchoscopy, using white-light illumination, has repeatedly shown a low sensitivity

Paris-Sud XI, Université de

421

Dynamic clonal analysis of murine hematopoietic stem and progenitor cells marked by 5 fluorescent proteins using confocal and multiphoton microscopy  

PubMed Central

We demonstrate a methodology for tracing the clonal history of hematopoietic stem and progenitor cells (HSPCs) behavior in live tissues in 4 dimensions (4D). This integrates genetic combinatorial marking using lentiviral vectors encoding various fluorescent proteins (FPs) with advanced imaging methods. Five FPs: Cerulean, EGFP, Venus, tdTomato, and mCherry were concurrently used to create a diverse palette of color-marked cells. A key advantage of imaging using a confocal/2-photon hybrid microscopy approach is the simultaneous assessment of uniquely 5FP-marked cells in conjunction with structural components of the tissues at high resolution. Volumetric analyses revealed that spectrally coded HSPC-derived cells can be detected noninvasively in various intact tissues, including the bone marrow, for extensive periods of time after transplantation. Live studies combining video-rate multiphoton and confocal imaging in 4D demonstrate the possibility of dynamic cellular and clonal tracking in a quantitative manner. This methodology has applications in the understanding of clonal architecture in normal and perturbed hematopoiesis. PMID:22995900

Métais, Jean-Yves

2012-01-01

422

Confocal imaging of whole vertebrate embryos reveals novel insights into molecular and cellular mechanisms of organ development  

NASA Astrophysics Data System (ADS)

Confocal microscopy has been an invaluable tool for studying cellular or sub-cellular biological processes. The study of vertebrate embryology is based largely on examination of whole embryos and organs. The application of confocal microscopy to immunostained whole mount embryos, combined with three dimensional (3D) image reconstruction technologies, opens new avenues for synthesizing molecular, cellular and anatomical analysis of vertebrate development. Optical cropping of the region of interest enables visualization of structures that are morphologically complex or obscured, and solid surface rendering of fluorescent signal facilitates understanding of 3D structures. We have applied these technologies to whole mount immunostained mouse embryos to visualize developmental morphogenesis of the mammalian inner ear and heart. Using molecular markers of neuron development and transgenic reporters of neural crest cell lineage we have examined development of inner ear neurons that originate from the otic vesicle, along with the supporting glial cells that derive from the neural crest. The image analysis reveals a previously unrecognized coordinated spatial organization between migratory neural crest cells and neurons of the cochleovestibular nerve. The images also enable visualization of early cochlear spiral nerve morphogenesis relative to the developing cochlea, demonstrating a heretofore unknown association of neural crest cells with extending peripheral neurite projections. We performed similar analysis of embryonic hearts in mouse and chick, documenting the distribution of adhesion molecules during septation of the outflow tract and remodeling of aortic arches. Surface rendering of lumen space defines the morphology in a manner similar to resin injection casting and micro-CT.

Hadel, Diana M.; Keller, Bradley B.; Sandell, Lisa L.

2014-03-01

423

Fibered confocal fluorescence microscopy for imaging apoptotic DNA fragmentation at the single-cell level in vivo  

SciTech Connect

The major characteristic of cell death by apoptosis is the loss of nuclear DNA integrity by endonucleases, resulting in the formation of small DNA fragments. The application of confocal imaging to in vivo monitoring of dynamic cellular events, like apoptosis, within internal organs and tissues has been limited by the accessibility to these sites. Therefore, the aim of the present study was to test the feasibility of fibered confocal fluorescence microscopy (FCFM) to image in situ apoptotic DNA fragmentation in surgically exteriorized sheep corpus luteum in the living animal. Following intra-luteal administration of a fluorescent DNA-staining dye, YO-PRO-1, DNA cleavage within nuclei of apoptotic cells was serially imaged at the single-cell level by FCFM. This imaging technology is sufficiently simple and rapid to allow time series in situ detection and visualization of cells undergoing apoptosis in the intact animal. Combined with endoscope, this approach can be used for minimally invasive detection of fluorescent signals and visualization of cellular events within internal organs and tissues and thereby provides the opportunity to study biological processes in the natural physiological environment of the cell in living animals.

Al-Gubory, Kais H. [Unite de Biologie du Developpement et de la Reproduction, Departement de Physiologie Animale, Institut National de la Recherche Agronomique, 78352 Jouy-en-Josas Cedex (France)]. E-mail: kais.algubory@jouy.inra.fr

2005-11-01

424

Depth-resolved characterization of UV cured coatings by confocal Raman and two-photon microscopy  

Microsoft Academic Search

UV cured coatings can be characterized very effectively by confocal Raman microscopy, real-time IR spectroscopy and two-photon laser scan microscopy. The first two vibrational spectroscopic methods for chemical imaging and kinetics of curing conversion, respectively, can help to optimize UV formulations and curing conditions, e.g. UV dosage or temperature. In contrast, two-photon laser scan confocal microscopy can be used to

W. Schrof; E. Beck; G. Etzrodt; H. Hintze-Brüning; U. Meisenburg; R. Schwalm

2001-01-01

425

Fuzzy logic and maximum a posteriori-based image restoration for confocal microscopy  

NASA Astrophysics Data System (ADS)

We propose a maximum a posteriori image restoration approach to 3D confocal microscopy. The image field is suitably modeled as a Markov random field, resulting in a Gibbs distributed image. A fuzzy-logic-based potential is employed in the Gibbs prior. Unlike other potentials, the fuzzy potential distinguishes intensity variation due to genuine edges and noise. The proposed approach has generated artifact-free restored confocal microscopy images.

Vicidomini, Giuseppe; Pratim Mondal, Partha; Diaspro, Alberto

2006-12-01

426

Fuzzy logic and maximum a posteriori-based image restoration for confocal microscopy.  

PubMed

We propose a maximum a posteriori image restoration approach to 3D confocal microscopy. The image field is suitably modeled as a Markov random field, resulting in a Gibbs distributed image. A fuzzy-logic-based potential is employed in the Gibbs prior. Unlike other potentials, the fuzzy potential distinguishes intensity variation due to genuine edges and noise. The proposed approach has generated artifact-free restored confocal microscopy images. PMID:17130910

Vicidomini, Giuseppe; Mondal, Partha Pratim; Diaspro, Alberto

2006-12-15

427

A simple confocal fibre-optic laser method for intraocular lens power measurement  

Microsoft Academic Search

PurposeTo develop novel confocal fibre-optic laser method (CFOLM) for accurate and objective measuring of the dioptric power of both positive and negative intraocular lenses (IOLs).MethodsThe CFOLM principle of operation is based on a simple apertureless single-mode fibre laser confocal design. The key element is a single-mode fibre coupler that serves simultaneously as a point light source (3–5 ?m fibre diameter)

I K Ilev

2007-01-01

428

Two-Dimensional MEMS Scanner for Dual-Axes Confocal Microscopy  

Microsoft Academic Search

In this paper, we present a novel 2-D microelectromechanical systems (MEMS) scanner that enables dual-axes confocal microscopy. Dual-axes confocal microscopy provides high resolution and long working distance, while also being well suited for miniaturization and integration into endoscopes for in vivo imaging. The gimbaled MEMS scanner is fabricated on a double silicon-on-insulator (SOI) wafer (a silicon wafer bonded on a

Hyejun Ra; Wibool Piyawattanametha; Yoshihiro Taguchi; Daesung Lee; Michael J. Mandella; Olav Solgaard

2007-01-01

429

Confocal and two-photon imaging in cartilage: expression patterns of Filamin A and B  

Microsoft Academic Search

Optical imaging in cartilage is challenging due to the high levels of intra- and inter-cellular autofluorescence. We report here on high-resolution confocal and two-photon imaging of endogenous fluorescence of cartilage and of exogenous fluorescence of filamin A and B protein markers. Confocal laser scanning microscopy offers the advantage of quasi-theoretical spatial resolution and minimizes the autofluorescence contribution by eliminating the

Sebastian Wachsmann-Hogiu; Deborah Krakow; Eiman T. Sebald; Cristina Bertolotto; Dora Acuna; Daniel L. Farkas

2004-01-01

430

Ca2+ Release Events in Cardiac Myocytes Up Close: Insights from Fast Confocal Imaging  

PubMed Central

The spatio-temporal properties of Ca2+ transients during excitation-contraction coupling and elementary Ca2+ release events (Ca2+ sparks) were studied in atrial and ventricular myocytes with ultra-fast confocal microscopy using a Zeiss LSM 5 LIVE system that allows sampling rates of up to 60 kHz. Ca2+ sparks which originated from subsarcolemmal junctional sarcoplasmic reticulum (j-SR) release sites in atrial myocytes were anisotropic and elongated in the longitudinal direction of the cell. Ca2+ sparks in atrial cells originating from non-junctional SR and in ventricular myocytes were symmetrical. Ca2+ spark recording in line scan mode at 40,000 lines/s uncovered step-like increases of [Ca2+]i. 2-D imaging of Ca2+ transients revealed an asynchronous activation of release sites and allowed the sequential recording of Ca2+ entry through surface membrane Ca2+ channels and subsequent activation of Ca2+-induced Ca2+ release. With a latency of 2.5 ms after application of an electrical stimulus, Ca2+ entry could be detected that was followed by SR Ca2+ release after an additional 3 ms delay. Maximum Ca2+ release was observed 4 ms after the beginning of release. The timing of Ca2+ entry and release was confirmed by simultaneous [Ca2+]i and membrane current measurements using the whole cell voltage-clamp technique. In atrial cells activation of discrete individual release sites of the j-SR led to spatially restricted Ca2+ release events that fused into a peripheral ring of elevated [Ca2+]i that subsequently propagated in a wave-like fashion towards the center of the cell. In ventricular myocytes asynchronous Ca2+ release signals from discrete sites with no preferential subcellular location preceded the whole-cell Ca2+ transient. In summary, ultra-fast confocal imaging allows investigation of Ca2+ signals with a time resolution similar to patch clamp technique, however in a less invasive fashion. PMID:23637847

Shkryl, Vyacheslav M.; Blatter, Lothar A.

2013-01-01

431

Optimizing the acquisition and analysis of confocal images for quantitative single-mobile-particle detection.  

PubMed

Quantification of the fluorescence properties of diffusing particles in solution is an invaluable source of information for characterizing the interactions, stoichiometry, or conformation of molecules directly in their native environment. In the case of heterogeneous populations, single-particle detection should be the method of choice and it can, in principle, be achieved by using confocal imaging. However, the detection of single mobile particles in confocal images presents specific challenges. In particular, it requires an adapted set of imaging parameters for capturing the confocal images and an adapted event-detection scheme for analyzing the image. Herein, we report a theoretical framework that allows a prediction of the properties of a homogenous particle population. This model assumes that the particles have linear trajectories with reference to the confocal volume, which holds true for particles with moderate mobility. We compare the predictions of our model to the results as obtained by analyzing the confocal images of solutions of fluorescently labeled liposomes. Based on this comparison, we propose improvements to the simple line-by-line thresholding event-detection scheme, which is commonly used for single-mobile-particle detection. We show that an optimal combination of imaging and analysis parameters allows the reliable detection of fluorescent liposomes for concentrations between 1 and 100 pM. This result confirms the importance of confocal single-particle detection as a complementary technique to ensemble fluorescence-correlation techniques for the studies of mobile particle. PMID:23824691

Friaa, Ouided; Furukawa, Melissa; Shamas-Din, Aisha; Leber, Brian; Andrews, David W; Fradin, Cécile

2013-08-01

432

Vital fluorescent labeling for confocal scanning microscopic study of living cell invasion  

NASA Astrophysics Data System (ADS)

Invasion by cells with malignant or transformed phenotypes precedes destruction of adjacent tissue and fatal cell metastasis. State-of-the-art confocal laser scanning technology facilitates both in vitro and in vivo research into cell invasion and metastasis. In particular, studies performed with living cells yield more precise information than those with fixed cells, giving new insight into cell invasion and metastasis. We have tested a variety of vital florescent dyes and fluorogenic protease substrates in our studies of invasion of cartilage by transformed synoviocytes or osteosarcoma cells. The fluorescent dyes tested include Calcein acetoxy methyl-FITC (Calcein), Hoechst 33342 (Hoechst), CellTracker, DiI, DiO, DiD, and ethidium bromide (EB). The fluorogenic protease substrate used Meoxysuccinyl-Gly-Pro-Leu-Gly-Pro-AFC (MOS-GPLGP-AFC) for detection of collagenase activity. We found that Calcein-FITC labeling permitted the clearest direct observation of the penetration of transformed synoviocytes and osteosarcoma cells into cartilage. Even better results were obtained when chondrocyte nuclei were counter-stained with Hoechst 33342. During the invasion process, collagenase activity was observed around the synoviocyte in the cartilage matrix labeled with the fluorogenic collagenase substrate. We concluded that of the vital fluorescent dyes tested, a combined application of Calcein-FITC, Hoechst 23223, and MOS- GPLGP-AFC is most appropriate for the study of the cell invasion process.

Wang, Allan Z.; Chen, Jian M.; Fisher, Gregory W.; Wang, Jane C.

1997-07-01

433

Three-dimensional visualization of termite (Apicotermitinae) enteric valve using confocal laser scanning microscopy.  

PubMed

Humivorous termites are dominant members of tropical rainforest soil communities. In the soil-feeding subfamily Apicotermitinae (Termitidae), the enteric valve connecting the first section of the hindgut to the paunch often displays a complex sclerotized armature everted towards the lumen of the paunch. This structure is central in termite taxonomy but its function remains hypothetical. Here, we evaluate the potential of confocal laser scanning microscopy to provide detailed imaging of the valve of Anoplotermes parvus, by comparison with bright-field microscopy and scanning electron microscopy. We detected a strong far-red emission of the enteric valve armature that sharply contrasted with the surrounding tissues, providing a convenient method to highlight minute structural elements of the valve and its three-dimensional structure. The method is easy to use and is applicable to standard archival material as demonstrated by images of enteric valves of four other Apicotermitinae species. It may represent a valuable asset for the study of termite enteric valves, for the purpose of taxonomy or functional morphology. PMID:24947115

Host, B; Twyffels, L; Roisin, Y; Vanderwinden, J-M

2014-08-01

434

Orbital Single Particle Tracking on a commercial confocal microscope using piezoelectric stage feedback.  

PubMed

Single Particle Tracking (SPT) is a technique used to locate fluorescent particles with nanometer precision. In the orbital tracking method the position of a particle is obtained analyzing the distribution of intensity along a circular orbit scanned around the particle. In combination with an active feedback this method allows tracking of particles in 2D and 3D with millisecond temporal resolution. Here we describe a SPT setup based on a feedback approach implemented with minimal modification of a commercially available confocal laser scanning microscope, the Zeiss LSM 510, in combination with an external piezoelectric stage scanner. The commercial microscope offers the advantage of a user-friendly software interface and pre-calibrated hardware components. The use of an external piezo-scanner allows the addition of feedback into the system but also represents a limitation in terms of its mechanical response. We describe in detail this implementation of the orbital tracking method and discuss advantages and limitations. As an example of application to live cell experiments we perform the 3D tracking of acidic vesicles in live polarized epithelial cells. PMID:25419461

Lanzanò, Luca; Gratton, Enrico

2014-06-01

435

3D optical sectioning with a new hyperspectral confocal fluorescence imaging system.  

SciTech Connect

A novel hyperspectral fluorescence microscope for high-resolution 3D optical sectioning of cells and other structures has been designed, constructed, and used to investigate a number of different problems. We have significantly extended new multivariate curve resolution (MCR) data analysis methods to deconvolve the hyperspectral image data and to rapidly extract quantitative 3D concentration distribution maps of all emitting species. The imaging system has many advantages over current confocal imaging systems including simultaneous monitoring of numerous highly overlapped fluorophores, immunity to autofluorescence or impurity fluorescence, enhanced sensitivity, and dramatically improved accuracy, reliability, and dynamic range. Efficient data compression in the spectral dimension has allowed personal computers to perform quantitative analysis of hyperspectral images of large size without loss of image quality. We have also developed and tested software to perform analysis of time resolved hyperspectral images using trilinear multivariate analysis methods. The new imaging system is an enabling technology for numerous applications including (1) 3D composition mapping analysis of multicomponent processes occurring during host-pathogen interactions, (2) monitoring microfluidic processes, (3) imaging of molecular motors and (4) understanding photosynthetic processes in wild type and mutant Synechocystis cyanobacteria.

Nieman, Linda T.; Sinclair, Michael B.; Davidson, George S.; Van Benthem, Mark Hilary; Haaland, David Michael; Timlin, Jerilyn Ann; Sasaki, Darryl Yoshio; Bachand, George David; Jones, Howland D. T.

2007-02-01

436

Optical coherence tomography and confocal endomicroscopy for rhinologic pathologies: a pilot study  

NASA Astrophysics Data System (ADS)

Optical coherence tomography (OCT) and confocal endomicroscopy (CEM) have a well-established potential for early diagnosis of pre-malignant and early malignant lesions of the upper aerodigestive tract mucosa. Additional applications in ENT-diagnostics might facilitate a more widespread use by making the investment into the devices more economic. Both imaging techniques might also provide valuable information in nasal pathologies. OCT images were generated with a surgical microscope (Möller-Wedel Hi-R 1000) with an integrated high-speed-OCT camera (Optomedical GmbH). For the CEM a Heidelberg Retina tomograph II scanner (Heidelberg Engineering GmbH) was used. Both during sinus surgery in vivo and from removed material ex vivo OCT and CEM images were taken and correlated with histopathological analysis after hematoxylin and eosin staining. Patients with inverted papillomas and chronic rhinosinusitis (CRS) were evaluated. Inverted papillomas show a variably thick epithelial layer on OCT and densely packed epithelial cells on CEM. They can be clearly distinguished from nasal polyps that show a very thin epithelial layer upon loose subepithelial tissue. In CRS CEM can distinguish areas with intact from areas with destroyed ciliated epithelium by directly visualizing ciliary movement. OCT sometimes showed thin superficial dense structures that might correspond to biofilms. OCT and CEM might provide valuable information in the follow-up care of patients with inverted papillomas and in diagnostics of CRS.

Olzowy, B.; Starke, N.; Schuldt, T.; Hüttmann, G.; Lankenau, E.; Just, T.

2013-06-01

437

Evaluation of human serum of severe rheumatoid arthritis by confocal Raman spectroscopy  

NASA Astrophysics Data System (ADS)

Rheumatoid Arthritis is a systemic chronic inflammatory disease, recurrent and systemic, initiated by autoantibodies and maintained by inflammatory mechanisms cellular applicants. The evaluation of this disease to promote early diagnosis, need an associations of many tools, such as clinical, physical examination and thorough medical history. However, there is no satisfactory consensus due to its complexity. In the present work, confocal Raman spectroscopy was used to evaluate the biochemical composition of human serum of 40 volunteers, 24 patients with rheumatoid arthritis presenting clinical signs and symptoms, and 16 healthy donors. The technique of latex agglutination for the polystyrene covered with human immunoglobulin G and PCR (protein c-reactive) was performed for confirmation of possible false-negative results within the groups, facilitating the statistical interpretation and validation of the technique. This study aimed to verify the changes for the characteristics Raman peaks of biomolecules such as immunoglobulins amides and protein. The results were highly significant with a good separation between groups mentioned. The discriminant analysis was performed through the principal components and correctly identified 92% of the donors. Based on these results, we observed the behavior of arthritis autoimmune, evident in certain spectral regions that characterize the serological differences between the groups.

Carvalho, C. S.; Raniero, L.; Santo, A. M. E.; Pinheiro, M. M.; Andrade, L. E. C.; Cardoso, M. A. G.; Junior, J. S.; Martin, A. A.

2010-02-01

438

Extraction of vegetation biophysical parameters by inversion of the PROSPECT + SAIL models on sugar beet canopy reflectance data. Application to TM and AVIRIS sensors  

Microsoft Academic Search

The PROSPECT leaf optical properties and SAIL canopy reflectance models were coupled and inverted using a set of 96 AVIRIS (Airborne Visible\\/Infrared Imaging Spectrometer) equivalent spectra gathered in afield experiment on sugar beet plots expressing a large range in leaf area index, chlorophyll concentration, and soil color. In a first attempt, the model accurately reproduced the spectral reflectance of vegetation,

S. Jacquemoud; F. Baret; B. Andrieu; F. M. Danson; K. Jaggard

1995-01-01

439